<p class='jove_content'><strong>Mohammed R. Milad</strong> is supported by NIMH grant R01 MH097880 and institutional funds from the Department of Psychiatry at MGH.</p>

<p class="jove_content">注：このプロトコルですべての手順は、マサチューセッツ総合病院のための施設内動物管理使用委員会（IACUC）となって研究動物管理小委員会によって承認され、健康のガイドラインの国立研究所に準拠しているされています。 </p><p class="jove_title"> 1.動物住宅及び取扱い手順</p><ol><li>木材チップの寝具3-4インチのプラスチックビンのグループで到着すると、家の大人のSprague Dawley雌ラット（200〜225グラムの重さ）、年齢の約8〜10週間。固形飼料および水に自由摂取へのアクセスの食事と12時間の明/暗サイクルでそれらを維持する。 1週間の最低住宅事情と動物施設に順応するために、ラットのままにしておきます。 <br />注：この原稿のすべての手順は、光サイクル中に行われている。 </li><li>この順応期間の後、2〜3日間、5分ごとに、すべての動物を扱う。適切に（胴体によってませ尾でサポートされている）一度にラット1を拾う、確実に固定して保持し、この時間の間に、それらをペット。激しく揺れる、またはより長い期間のために心配して、ストレスをより多く表示された動物を扱う。このプロトコルでは、次の手順に影響を与える可能性があり、ストレスを扱う最小化するためにこれを行います。 <br />注記：動物の取り扱い時の日数および量は、異なる研究室間で変化させることができる。しかし、これらは、同じラボ内での実験の間で一貫している必要があります。 </li></ol><p class="jove_title">膣スワブスミアと染色手順：発情周期を監視する2. </p><ol><li> 0.9％食塩水（塩化ナトリウムを蒸留水に溶解）を作る。この溶液中で綿棒を湿らせます。不十分なサンプル収集または細胞の喪失につながる可能性が過飽和を回避するためにペーパータオルを使用して先端ブロット。上向きに離れて膣口から尾を持ち、静かに緩い膣の細胞を捕捉するために、壁の周りの膣管とロール状に綿棒を挿入します。 </li><li>動物はベッドに排尿した場合尿汚染が相同定のために、それが困難になりますようにトンの先端は、新しいものと交換してください。ストレスへの暴露が発情周期を混乱されるため、この手順の間に動物に苦痛を与えないよう十分に注意してください。拭き取りすると、偽妊娠を誘導することができる子宮頸部への余分な刺激を最小にする深すぎないが、迅速挿抜を実現することを目指しています。 <br />注：偽妊娠、 <em>すなわち</em>典型的には約12日間続く ​​非環発情周期、発情<sup>25</sup>の連続した日として同定することができる。 </li><li>慎重にアプリケータ先端部を除去し、予め標識顕微鏡スライド上にそれをロール。スライド上あまりにも多くの流体としてあまりにもハードダウン押すとドライ一度相同定を困難にすることができないようにしてください。 <br />注：これは個人の好みに応じて行うことができるが、一つのスライドは、各動物の複数の日を含むことができる。 </li><li>スライド上のサンプルの転送を確認してください。断つためのサンプルを収集1スライド上のAl日間連続、より追跡できるようにし、毎日の発情期の変更を識別します。 <br />注：可能な場合はサンプルを収集する人々は、すべての動物のために同じままなら、それはまた、理想的です。 </li><li>スライドが乾燥していると、位相識別のための染色プロトコルを開始する。染色キット（材料の表を参照）を使用し、固定液（水色）のスライドを10回浸す、（ピンク）染色液で10倍、と対比溶液中の5倍（紫）。流水で軽くスライドをすすぐ。顕微鏡下で表示する前にスライドを完全に空気乾燥してみましょう。 <br /> NOTE：発情（E）、発情（M）、発情間期（D）、および発情前期<sup>（P）26：</sup>一般的に4~5日長い発情周期を（この順序で）で構成されている。発情期は、青、角化細胞によって特徴付けられる白血球による発情及び角化および有核細胞の組み合わせ、それらは非常に疎である以外は、発情間期細胞型の存在下での発情と同様であり、紫色に染色された凝集によって発情さの有核細胞（ <strong>図1）。</strong>膣スミア診のために等しく有効である上述のものに加えて、種々の染色手順は、がある。 </li><li>実験前に正確に位相を監視するために、少なくとも2つの完全なサイクル（〜8〜10日）のためにサンプルを収集する。サンプルが取られる時間帯と一致している。全体と実験の終了まで毎日の膣スメアサンプルを収集します。 </li></ol><p class="jove_title"> 3.事前暴露</p><ol><li>実験の開始前に、チャンバーは動物がどんな行動試験の前にコンテキスト（空調室）に順応できるように調節する動物​​を事前に公開します。 <ol><li>すべての実験の前に3日間、一日あたり20〜30分に家のライトが付いている（音減衰ボックスにあります）空調室にメスを事前に公開します。彼らは研究のための彼らの室と事前にさらされているボックスを割り当てます。完全に洗浄トン彼らは行動と発情周期に影響を与えることができるので、臭いを除去するためのセッションと動物の間、彼は箱（壁やトレー）。 </li></ol></li></ol><p class="jove_title"> 4. 1日目：馴化/恐怖条件付け</p><ol><li>動物は彼らの発情周期の発情期にあることが確認された後、3日間の実験の馴化/コンディショニングフェーズを開始。 <ol><li>実験前の各日に刺激（CS）のプレゼンテーションを条件付け最初のトーンに凍結の前トーンベースライン対策を行ってください。 CS発症前の最初のCS-単独の裁判の開始時に刺激不在の時間間隔の間に（100を掛けた裁判の期間によって不動費やし秒で除して算出、）％の凍結のスコアを取得することによってこれを行います。 <br />注：これらの対策は、馴化、コンディショニング、消滅、およびリコール時とベースライン凍結レベルを評価し、比較することができる。 </li><li>発情後期フェーズの間に絶滅の研修を実施する、発情期の彼らの最後の日に、ラットを条件付け。綿棒と識別する発情期（ステップ2）実験プロトコル（空調/絶滅/リコール）を開始する前に、毎日。発情期は1日より長く続くことのような動物がトレーニングを開始する準備ができたら、使用サイクル履歴が決定するために、位相の長さを予測する。 </li></ol></li><li>空調室では、電気刺激発生器に足ショックグリッドの床に接続します。無条件刺激（US）として0.5〜0.6ミリアンペアの刺激レベルを使用します。条件刺激（CS）として4 kHzの、80デシベルの音を使用してください。 <br />注：これらのパラメータは、実験室間で異なることができ、最適なコンディショニングのために修飾することができる。 <ol><li>凍結解析プログラムは、視覚的な手がかりを（一時的ではなく）が必要な場合は、トーンにLED光を共活性化する。ビデオフレーム内の、オペラントチャンバーの外側に光を置きます。各試験の開始時に、LEDライトを活性化し、それが目の終わりまで照らされ続けるEトライアル。 <br />注：この光は動物では表示されませんとだけ開始及び（凍結挙動を測定するために使用される）を記録したビデオファイル内の試験終了のためのマーカーとして役立つ。 </li></ol></li><li>慣れの5 CS-単独の試験のための空調室に動物を置きます。すぐに慣れセッション以下、恐怖条件付けの7ペアCS-USの試験を行う。 CS音が30秒間持続し、0.5秒、米国のショックにcoterminatesていることを確認してください。 3分を平均可変試行間間隔ですべてのセッション（慣れ、エアコン、絶滅、およびリコール）で試験を実行します。 </li><li>コンディショニングセッションの最後に、次の日まで、ホームケージに及び動物施設に動物を返す。 </li></ol><p class="jove_title"> 5. 2日目：エストラジオール準備</p><ol><li>このプロトコルの1日目を受けたすべての動物のための発情期を綿棒識別する。エストラジオールを準備します（またE2、、17β-エストラジオール、またはとして知られているビヒクルとしてゴマ油または0.9％生理食塩水を用いて15μgの/ kgの用量の皮下注射のためのベータ - エストラジオール）。 </li><li>注射の準備をそれらがこのプロトコルの1日目に調整したときに測定し、記録した全ての動物の体重を使用するエストラジオールの量を算出する。 </li><li>ラットあたりエストラジオール（ <em>すなわち</em> 0.2ミリリットル）の投与量を標準化するために計算を行う。エストラジオールは、その水不溶性に溶解させることは困難であり、少量のために大量の溶媒を必要とするので、溶解するまで、弱火ゴマ油中のエストラジオールを混合することにより原液を調製。次いで、溶液を汚染物質を除去するために0.22μmのフィルターを通過させることができる。例えば、動物当たり0.2ミリリットル注入量では15μg/ kgの用量を達成するために、ごま油の合計に必要な体積に3000μgのエストラジオール/ 1ミリリットルゴマ油原液の計算されたボリュームを追加する。 <br />注：あるいは、エストロゲンTHAの他の形態を使用する<html> tは、水溶性および溶解が容易である。 </li></ol><p class="jove_title"> 6. 2日目：エストラジオール管理/絶滅トレーニング</p><ol><li>エストラジオールを皮下投与する。穏やかなピンチに首、肩甲骨の間でたるんだ皮膚を持ち上げ、皮膚折り目によって形成される三角形に注射針を挿入します。 </li><li>エストラジオールの皮下注射後30分、再びコンディショニング室で動物を配置し、絶滅のトレーニングを始める。この絶滅セッションでは、3分の平均を可変試行間間隔で発表され、30秒、4 kHzの、80デシベルの音、からなる各試行で、20 CS-単独の試験を行う。 <br />注：エストラジオール前絶滅の訓練にか、すぐに絶滅後に投与されたときにリコールに対するエストラジオールの効果が発生します。効果は4時間後に絶滅を観察していないので、それはトレーニングセッション<sup>15</sup>の開始または終了に時間的に近い注入することをお勧めします。 </li></ol>ル &quot;&gt; 7 3日目：絶滅リコール</p><ol><li>絶滅のトレーニング後24時間、1日目とこのプロトコルの2を完了した動物が綿棒。 </li><li> （1日目と2と同じ）、割り当てられた空調室に動物を置きます。ステップ6.2で説明したように絶滅の訓練のために投与20試行に似て試行間間隔を持つ唯一の3.80デシベルCS-単独の臨床試験で構成されて3 CS-単独の臨床試験（絶滅のリコールの3件の試験）を、提示することによって、絶滅リコールセッションを開始します。 </li><li>リコールセッションが完了すると、ホームケージに動物を返す。 </li></ol><p class="jove_title"> 8.データ解析</p><ol><li>映像を通じて行動データを取得し、コンピュータソフトウェアを使用して分析する。 <br />注：凍結スコアは手動でも各試行のCSプレゼンテーション中に凍結発作のタイミングによる薬物治療に盲目である実験者によってカウントすることができ、音の間に凍結した時間の割合として表さ。凍結がある30秒CS-USの試験中の呼吸を除いて、運動の完全な欠如によって定義される。 100を掛けた30秒（トライアルの期間）によって（不動）を凍結費やし秒で割って％の凍結を計算します。 </li></ol>

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<li>Markowska, A. L., Savonenko, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effectiveness+of+estrogen+replacement+in+restoration+of+cognitive+function+after+long-term+estrogen+withdrawal+in+aging+rats%5BTitle%5D)+AND+%22Journal+of+Neuroscience%22%5BJournal%5D)">Effectiveness of estrogen replacement in restoration of cognitive function after long-term estrogen withdrawal in aging rats.</a> <em>Journal of Neuroscience</em>. <strong>22</strong> (24), 10985-10995 (2002).</li>
<li>Bredemann, T. M., McMahon, L. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((17%CE%B2+Estradiol+Increases+Resilience+and+Improves+Hippocampal+Synaptic+Function+in+Helpless+Ovariectomized+Rats%5BTitle%5D)+AND+%22Psychoneuroendocrinology%22%5BJournal%5D)">17β Estradiol Increases Resilience and Improves Hippocampal Synaptic Function in Helpless Ovariectomized Rats.</a> <em>Psychoneuroendocrinology</em>. <strong>42</strong>, 77-88 (2014).</li>
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<p class="jove_content">この原稿の著者は、開示することはなく、競合する経済的利益やその他の利害関係はありません。 </p>

<p class="jove_content">恐怖の絶滅は、様々な操作の下で特定され、評価され、馴化恐怖消去を仲介する神経機構と雄ラットで広く研究されてきた。比較的少数の研究は、雌ラットや恐怖消去における性腺ホルモンの役割を検討した。特に恐怖消去に対するエストロゲンの効果を研究するために、自然に循環する雌ラットは、3日間の行動パラダイムに供される。この手順では、馴化/エアコン、絶滅、絶滅リコールのフェーズで構成されています。このプロトコルを使用して、メスのラットは、高エストロゲン発情前期<sup>15</sup>で消滅する雌に比べて低エストロゲン発情後期段階を示す、より高い冷凍（または損なわ消光リコール）の間に絶滅の訓練を受けたことが実証されている。発情期の間消光トレーニング前のエストラジオールの投与は、消光メモリ<sup>16</sup>の連結を調節する。これはfreezinの減少によって証明される絶滅のリコール時にグラム。まとめると、これらの結果は、卵巣ホルモンの影響や行動上の発情周期に着目して女性の研究を行うことの重要性を強調。対照実験は、ここに記載されていないが、それはない消光基<em>、すなわち</em> 、さらなる消光記憶固定に関与するプロセスにおけるエストロゲンの影響を評価するために、適切なコントロールを含めることが必要であろう。 </p><p class="jove_content">このプロトコルの目的は2つある：1）無傷動物における発情周期の特定の段階の間に調整さ恐怖消去に対するエストロゲンの効果を調査するため、及び2）女性の通常の低エストロゲン状態の間にどのように急性エストラジオール置換を調べることができるその動作を調節する。ここで説明する膣スワブの手順により、発情周期の4つのフェーズを特定することができる：発情、発情後期、発情間期、および発情前期を。これは、私たちは時の卵巣ホルモンSU挙動を評価することができますエストロゲンなどのchが低いと高濃度で当然である。例えば、エストロゲンレベルが発情（20〜40 pg / mlで）、発情後期（15〜20 pg / mlで）の間に低く、発情間期（25〜40 pg / mlで）の相を、しかし発情中に高い（〜75頁発情周期<sup>27,28</sup>の/ ml）の相。これらの相はホルモン環境においても持続時間が異なるだけでなく。変数が、発情は、典型的には12〜14時間持続することが観察されている。 25から27時間、発情期。 6から8時間、発情後期。そして55から57時間、発情間期。各段階の持続時間は、発情間期または発情期のいずれかの2日を含む5日周期につながる日（動物に依存して）より長くても短くてもよい。前述したように、発情と発情後期が短く相（それぞれ12-14と6-8時間、）であり、見落とされることがあります。このプロトコルでは、絶滅の訓練を思い出す能力の間の位相差を調べるために、動物の自然循環ホルモンを使用するときに慎重に発情周期をモニターすることが重要である前日から。雌ラットの性周期は、多くのヒトの月経周期のように、また、 <em>年齢</em> 、ストレス、時刻、住宅条件、温度、などの多くの外部要因に敏感であり、実験を計画する際に考慮されるべきである。動物は、非環式（拡張発情期/発情間期）になるか、研究の前または中に不規則なサイクル（5日より4日以上より短い）が表示されることがあります。この場合には、これらの動物は発情周期の特定の段階の間に試験の厳格され、実験的な解析から除外される。注意することが重要なのは、それが少し困難明確に位相を特徴づける特定の細胞型を同定すること、試料が粘液と混合される間の遷移段階である。これはまた、綿棒が取られる時間に起因し得る。塗抹標本収集中粘液様放電の過剰量は、毎日の拭き取りの結果として存在する場合、いくつかの処理日拭き取ることなく通過することを可能にこの問題を解決することができます。 </p><p class="jove_content">ここで説明発情位相識別方法に加えて、他の方法論的ツールは、血清、卵巣ホルモンの循環濃度の測定値を得るために使用することができる。例えば、エストロゲン濃度は、酵素結合免疫吸着検定法（ELISA）を用いて、血液試料中で定量することができる。この手順では、血清/血漿試料中のエストロゲンは、酵素に結合されている特定の抗エストロゲン抗体に結合する。酵素の基質は、分光光度計を用いて測定することができる色の変化として可視シグナルを生じる反応を生成する。このツールは、吸光度を計算し、サンプル中のエストロゲンレベルの定量化を提供します。この方法は、実験中の特定の時間に、さらに重要なことには発情周期にわたってエストラジオールレベル変動や自然に評価するのに有用であり得る。またノルムを変更することができるエストロゲンの方法外因性投与を決定するために使用することができるら生理的濃度。血液からのエストロゲン濃度の測定は、遷移段階で相同定の困難を防ぐことができ、またはスミアサンプル中の粘液による読み取りが困難である場合。残念ながら、この方法は非常に高価になり、膣スミアコレクションに比べて遅延した結果を提供しています。 </p><p class="jove_content">手順は、十分な血液サンプルを得るために<em>、例えば</em> 、尾静脈、眼窩洞、尾スニップ、および伏在静脈<sup>29</sup>を介して、動物に不必要なストレスを引き起こすことがある。これは不正確または斜めに測定結果につながる、実験の重要な時期にホルモンレベルに影響を与える可能性がある。エストラジオールのレベルを測定するために、トランクの血液を使用する端末であり、したがって、相内のホルモンの変動についての非常に限られた情報を提供する。膣細胞診を評価することは、より良い代替手段を提供するように思われる。このメソッドは発情期間で卵巣ホルモンプロファイルの概算を提供するかもしれないが、それができるストレスを最小限にし、その後に少ない破壊的な行動実験にある。 </p><p class="jove_content">そのようなエストリオール、エストラジオール、エストロン、天然ヒトおよび非ヒト動物において循環しているエストロゲン様ステロイドの異なる形態がある。このプロトコルでは、エストラジオールは、急性皮下注射を介して投与される。それは自然に非妊娠雌<sup>30</sup>におけるエストロゲンの天然の最も強力な形態であるため、エストラジオール（E2、17ベータ-エストラジオールまたはβ-エストラジオールと同義）は、このプロトコルで使用されている。エストラジオールの急性注射とは対照的に、他の研究室は、慢性エストロゲン投与の方法を採用している。例えば、徐放性ペレットまたはシラスティックカプセルの皮下インプラントは、エストロゲンまたはビヒクル溶液<sup>19</sup>の安定した、連続的な送達を可能にする。この手順は、典型的には、動物の自然な生殖状態を解消卵巣切除と組み合わせて使用​​される。 </p><p class="jove_content"> manipuここで説明lationsは検査所見の臨床応用を促進するために、自然のホルモンの状態に焦点を当てています。心的外傷後ストレス障害（PTSD）を持つ個人は、一般的に彼らの心的外傷体験に関連した刺激の恐怖を消滅させると、この絶滅を覚えて自分の能力が損なわれている。この状態は、多くの場合、イベントが経過した後も長く持続する。長期暴露療法は​​、そのようなここで説明するように、齧歯類モデルで研究絶滅ベースのプロセスに依存しているPTSDのための一般的な治療オプションです。興味深いことに、女性は男性がストレスや不安関連精神障害<sup>31を</sup>発症するとほぼ倍の可能性があります。有病率のこの性差は恐怖消去プロセスにおける性差にリンクされ、これらの検査所見の潜在的な臨床的意義を根底にしてもよい。女性ではPTSDの高い有病率にもかかわらず、比較的少数のはげっ歯類で絶滅の研究は女性で行われている恐れている。女性研究が焦点行動の性差を検討する際に性腺ホルモンの役割でる見落としてはならない。発情周期間で自然に変動するホルモンレベルの行動への影響を特徴づけることは、男性と女性の間での動作の根本的な違いに貴重な洞察を提供しています。このプロトコルは、卵巣ホルモンやへの影響の将来の研究を促進するための基本的なモデルを提供しますが、そのような恐怖消去などの認知および行動のプロセスが、これらに限定されない。このプロトコルは、特定の性腺ホルモンに焦点を当てて、エストロゲンは、しかし、そのようなプロゲステロンおよびテストステロンなどの他のホルモンの効果を評価することもできる。他の薬理学的、細胞、および分子技術（ <em>すなわち</em> 、ローカライズされた薬剤注入、免疫組織化学、ウェスタンブロット）と組み合わせて本明細書に提示行動パラダイムを使用して、今後の研究は、行動療法を増強することができる脳内のエストロゲン作用の特異的部位/標的を識別することができる。 </p>

<p class="jove_content">固有性差は、ヒトとげっ歯類の両方で様々な認知行動や学習パラダイム間で観察される。例えば、男性は、良好な空間能力<sup>1-3を</sup>有し、一方、女性は、一般的に、より強力な口頭および詳細指向能力を有することが報告されている。これらの性差は、性腺ホルモンの影響に一部起因することができる。高いエストラジオールレベルは、女性がより良いである、タスクのパフォーマンスを向上させることが、男性は一般的にうまく<sup>4-6を</sup>行うタスクのパフォーマンスを悪化させる。この証拠は説得力があるが、完全にヒトでの研究で、実験環境を制御するために、限られた能力は、行動上のこれらの効果はホルモンに特異的に起因することができた場合、それが困難に決定することができる。動物実験は、対照的に、完全に制御された状況を可能にする。 </p><p class="jove_content">恐怖消去の基本的な神経機構が同定されており、よく男性で研究されているが、かどうかは不明であるこれらのシステムは、女性またはそれらがどのように発情周期にわたって変更は同じである。恐怖条件付けと絶滅広く不安障害に関連する研究を行うために、げっ歯類およびヒトにおける行動パラダイムを使用している。女性は、不安障害のリスクが高いだけでなく、より高い症状の持続期間および重症度<sup>7~13を</sup>有すること<sup>を</sup>考えれば、これらの研究において、女性を含めることが重要である。本研究では、女性の過少は、性ホルモンの行動への影響のための発情期の監視と会計の課題に起因すると考えられる。しばしば報告されていない行くか、または彼らの研究のための方法に記載されていないこの点に関して遭遇問題にメスを調べてやる研究所。 </p><p class="jove_content">げっ歯類で証拠を新興恐怖消去における性差は生殖腺ホルモン<sup>14-18</sup>で変調されていることを示唆している。恐怖条件付けでは、動物は特定の刺激を恐れるように訓練されている。の未強化の発表数の後刺激は、動物はキュー、絶滅と呼ばれるプロセスを恐れることはない学ぶ。どれだけ動物を学習し、絶滅のトレーニングの後にいくつかの時間を与えられた吸光リコールテスト中に観察することができ、このタスクを学習するのメモリを統合します。絶滅のリコール時の少ない恐怖式が良い絶滅メモリの統合を示しています。私たちの研究室からの最近の知見は、エストロゲンは恐怖消去メモリの統合を調節し、絶滅のリコールを改善できることを示唆している。具体的には、発情前期に消滅している雌ラットは、発情周期の位相はその間エストロゲンレベルのピーク、絶滅メモリの展示強化保持を循環させる。対照的に、前または直後の吸光トレーニング<sup>15,16</sup>の後、外因性エストラジオールの投与によって改善することができ、低エストロゲン発情後期相表示比較的乏しい吸光リコールに消滅する雌。絶滅メモリの統合の神経機構（税込雌の生殖腺ホルモンの役割を）udingすることは明らかではない。 </p><p class="jove_content">実験動物では、ホルモンの役割は、去勢および卵巣摘出などの侵襲的な外科的除去の手順を使用して調べることができる。手術からの回復に続いて、性腺ホルモンは、多くの場合、外因的行動のタスク<sup>19</sup>の実行中に操作されます。このアプローチは、性ホルモンについての重要な情報を提供し、それが<sup>20〜23（</sup>タイミングと投与量の面で）性腺ホルモンのよく制御された操作を可能にしているため便利ですしている。しかし、このアプローチは、発情周期にわたって生じる、天然に存在する変動の影響を評価せず、また、彼らは、それによってヒトの研究に並進可能性を制限する、「正常な」動物を表しています。これは、特定の発情周期の位相、及びサイクル内のエストロゲン受容体発現の変化で女性ホルモンのレベルがピークと衰退することを十分に文書化された、と卵巣摘出<sup>24</sup>の後。したがって、確実に高および低エストロゲン状態はそれらの寿命を通して、女性に与えることができるという効果を研究するために無傷の生殖腺とメスの研究を実施し、実験計画を改善する必要がある。 </p><p class="jove_content">このプロトコルは、恐怖消去に関与神経生物学的システムでのエストロゲンの影響に焦点を当てています。 1）慎重に、発情周期を監視2）全身投与のためのエストラジオールの効果的な用量を準備し、3）恐怖条件、絶滅が含ま行動パラダイムに従っており、自然にサイクリング雌ラットをでリコール：それはどのように説明しています。このプロトコルは、より良好な消光挙動恐怖条件付けで観察された性差を理解するために研究を支援するために他の薬理学的操作および細胞および分子ツールを使用して修飾することができる。以下の手順は、私たちの研究室内で利用するものである、と私はこれらの手順の多くの変形が存在することに注意してくださいnの文学。 </p>

<table><tbody><tr><td>Fear conditioning chamber</td><td>Coulbourn Instruments</td><td></td><td></td></tr><tr><td>Graphic State</td><td>Coulbourn Instruments</td><td></td><td></td></tr><tr><td>Sound-attenuating box</td><td>Med Associates, Inc.</td><td>NIR-022MD</td><td></td></tr><tr><td>Estradiol</td><td>Sigma-Aldrich</td><td>E1024</td><td>In sesame oil for subcutaneous injection</td></tr><tr><td>Sesame oil</td><td>Sigma-Aldrich</td><td>S3547-250ML</td><td></td></tr><tr><td>Freezescan</td><td>Cleversys, Inc.</td><td></td><td></td></tr><tr><td>Dip quick stain</td><td>Jorgensen Laboratories, Inc.</td><td>J0322A1, J0322A2, J0322A3</td><td></td></tr><tr><td>Cotton-tipped applicators</td><td>Fisher Scientific</td><td>23-400-114</td><td>6-inch, sterile</td></tr><tr><td>0.9% saline</td><td>LabChem, Inc.</td><td>LC23460-2</td><td>Sodium chloride w/v</td></tr><tr><td>Selectfrost microscope slides</td><td>Fisher Scientific</td><td>12-550-003</td><td></td></tr><tr><td>Virex II 256</td><td>Diversey, Inc.</td><td>5019317</td><td>Dilute 1:256 with water</td></tr><tr><td>Luer-Lok Tip 1ml Syringes</td><td>Becton Dickinson</td><td>309628</td><td></td></tr><tr><td>Hypodermic disposable needles</td><td>Exelint International, Co.</td><td>26402</td><td>26-gauge</td></tr></tbody></table>

protocol for studying extinction of conditioned fear in naturally cycling female rats

<p class="jove_content">条件付け恐怖の絶滅は広範囲に男性のげっ歯類で研究されてきた。最近では、特定の行動のタスクとレスポンス行動のための神経機構は、女性と男性では異なっていることを示す研究が増えてきた。調査研究にメスを使用すると、それらの発情周期中の性腺ホルモンの変化の挑戦を表すことができます。このプロトコルは、雌ラットの恐怖絶滅メモリの統合におけるエストロゲンの役割を調査するのに有用である十分に確立された手順を説明します。発情周期と外因性エストロゲンの投与の前に消光訓練の位相が2​​4時間後に吸光リコールに影響を与えることができる。ここで説明発情相同定のための膣拭き取り技術は自然に性腺ホルモンをサイクリングの検査と操作を補助する。この基本的な齧歯動物モデルの使用は、中恐怖消去メモリを調節することができるエストロゲンメカニズムを描写することができるメス。 </p>

<p class="jove_content">この恐怖消リコールプロトコルでは、パーセント凍結は恐怖の指標として測定した。よく消滅と絶滅の訓練の記憶を保持した動物は、絶滅のリコール時の行動試験の最終日に、低恐怖を示した。オスとメスのラットは大幅にエアコン、絶滅の間、条件付け恐怖の表情が異なり、相（ <strong>図2）</strong>覚えていません。動物は高および低エストロゲン発情位相群として別々に分析されている場合しかし、性差が明らかになります。発情周期の低エストロゲン発情後期フェーズの間に絶滅の訓練を受ける雌ラットは、絶滅の3日目のメモリだけでなく、発情前期の訓練を受けたもの（ <strong>図3）を</strong>覚えていません。これらの発情後期の女性はまた、男性に比べて消光リコール（貧弱な絶滅メモリ）の間に有意に大きな恐怖の回復を示す。しかし、発情後期の女性は皮下injecあるときテッドは絶滅学習の前にエストラジオール15μgの/ kgの用量で、恐怖の絶滅メモリの統合は、絶滅のリコール（ <strong>図4）</strong>の間に低凝固によって実証されるように強化されているように見える。したがって、これらのデータは、性腺ホルモンは恐怖消去リコールを調節し、また、条件付け恐怖絶滅行動の性差を媒介することができることを示している。 </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="図1" src="/files/ftp_upload/52202/52202fig1highres.jpg" /><br /> <strong>図1：発情サイクルフェーズ全体の細胞型の代表的な画像（倍率20X）</strong>発情前期ラウンド、紫色の染色された核上皮細胞の塊が特徴です<strong>。。</strong>発情はブルー染色、扁平角化細胞の凝集によって同定することができる。発情休止期および細胞型（白血球、有核および角化細胞）の組み合わせを発現するが、より少ない細胞を示す。エストロゲンレベルは、発情期全体で変動する、発情前期の間にピークに達する。 （メット=発情後期;。ジースト=発情間期; Proest =発情前期）。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/52202/52202fig1large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="図2" src="/files/ftp_upload/52202/52202fig2highres.jpg" /><br /> <strong>図2：実験の3段階にわたる男女間の比較が</strong>慣れ（。HAB）で観察された有意な性差はありません、コンディショニング（。COND）、絶滅、あるいは実験<sup>15</sup>の位相を思い出す。 </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="図3" src="/files/ftp_upload/52202/52202fig3highres.jpg" /><br /> <strong>図3：発情前期の間の動作の違い（高エストロゲン）と発情後期（低エストロゲン）女性の</strong>高エストロゲン発情前期相Oで女性<strong>。</strong>発情周期の展示低エストロゲン発情後期のものよりも少ない恐怖F。これらのデータは、自然循環女性におけるエストロゲンレベルが後<sup>15</sup>リコール24時間を調節する、恐怖消去メモリの統合に影響を与えることができることを示唆している。 </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="図4" src="/files/ftp_upload/52202/52202fig4highres.jpg" /><br /> <strong>図4：発情後期の女性におけるエストロゲン治療。絶滅の訓練（矢印）の前にエストラジオールの30分の投与は、車両<sup>16</sup>に比べて絶滅のリコールを容易にします。</strong> </p>

Watch this Scientific Journal Video about Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats at JoVE.com

Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats

<p class='jove_content'>Gonadal hormones such as estrogen modulate memory formation in a number of experimental paradigms including fear extinction memory. This protocol describes a set of methods for investigating the influence of gonadal hormones specifically during extinction in naturally cycling females, including estrous cycle monitoring and exogenous estrogen administration.</p>

当然の雌ラットをサイクリングで馴化恐怖の消滅を研究するためのプロトコル

Extinction of conditioned fear has been extensively studied in male rodents. Recently, there have been an increasing number of studies indicating that ...

protocol-for-studying-extinction-conditioned-fear-naturally-cycling

Nanyang Technological University

Research

JoVE Journal

Behavior

13.3K ビュー.  Massachusetts General Hospital. Gonadal hormones such as estrogen modulate memory formation in a number of experimental paradigms including fear extinction memory. This protocol describes a set of methods for investigating the influence of gonadal hormones specifically during extinction in naturally cycling females, including estrous cycle monitoring and exogenous estrogen administration.

ビデオ: Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats

Scientific Method

<p>The scientific method is used to solve problems and explain phenomena. The development of the scientific method coincided with changes in philosophy underpinning scientific discovery, radically transforming the views of society about nature. During the European Renaissance, individuals such as Francis Bacon, Galileo, and Isaac Newton formalized the concept of the scientific method and put it into practice. Although the scientific method has been revised since its early conceptions, much of the framework and philosophy remains in practice today.</p>
<h4>Step 1: The Observation and Question</h4>
<p>Prior to investigation, a scientist must define the question to be addressed. This crucial first step in the scientific process involves observing some natural phenomena of interest. This observation should then lead to a number of questions about the phenomena. This stage frequently requires background research necessary to understand the subject matter and past work on similar ideas. Reviewing and evaluating previous research allows scientists to refine their questions to more accurately address gaps in scientific knowledge. Defining a research question and understanding relevant prior research will influence how the scientific method is applied, making it an important first step in the research process.</p>
<p>An everyday example: You are trying to get to school or work and your car won&#8217;t start. The thought process that most people go through in that situation clearly mirrors the official scientific method (after you are finished getting upset). First, you make an observation: my car won&#8217;t start! The question that follows: why isn&#8217;t it working?</p>
<h4>Step 2: The Hypothesis</h4>
<p>The next step is making a hypothesis, based on prior knowledge. A hypothesis is an &#8220;uncertain explanation&#8221; or an unproven conjecture that seeks to explain some phenomenon based on knowledge obtained while executing subsequent experiments or observations. Generally, scientists develop multiple hypotheses to address their questions and test them systematically.</p>
<p>All hypotheses must meet certain criteria for the scientific process to work. First, a hypothesis must be testable and falsifiable. This aspect of the hypothesis is critical and of much greater importance than the hypothesis being correct. A testable hypothesis is one that generates testable predictions, addressed through observations or experiments. A falsifiable hypothesis is one that, through observation of conflicting outcomes, can be proven wrong. This allows investigators to gain more confidence over time, not by accumulating evidence showing that a hypothesis is correct, but rather by showing that situations that could establish its falsity do not occur.</p>
<p>Hypotheses come in two forms: null hypotheses and alternative hypotheses. The null hypothesis is tested against the alternative hypothesis and reflects that there will be no observed change in the experiment. The alternative hypothesis is generally the one described in the previous two paragraphs, also referred to as the experimental hypothesis. The alternative hypothesis is the predicted outcome of the experiment. If the null hypothesis is rejected, then this builds evidence for the alternative hypothesis.</p>
<p>An everyday example: Maybe it is freezing outside and therefore it is fairly likely that your car battery is dead. Maybe you know you were low on gas the night before and therefore it is likely that the tank is empty.</p>
<h4>Step 3: Experimentation and Data Collection</h4>
<p>Either way, the next step is to make more observations or to conduct experiments leading to conclusions. Following the formulation of hypotheses, scientists plan and conduct experiments to test their hypotheses. These experiments provide data that will either support or falsify the hypothesis. Data can be collected from quantitative or qualitative observations. Qualitative information refers to observations that can be made simply using one&#39;s senses, be that through sight, sound, taste, smell, or touch. In contrast, quantitative observations are ones in which precise measurements of some type are used to investigate one&#39;s hypothesis.</p>
<p>An experiment is a procedure designed to determine whether observations of the real world agree with or refute the derived predictions in the hypothesis. If evidence from an experiment supports a hypothesis, that gives the hypothesis more credibility. This does not indicate that the hypothesis is true, as future experiments may reveal new information about the original hypothesis. Experimental design is another critical step in the scientific method and can have a great effect on the results and conclusions one draws from an experiment. Careful thought and time should be devoted to experimental design and minimizing possible errors. The experiment should be designed so that every variable or factor that could influence the outcome of the experiment be under control of the researcher. Two types of variables are used to describe the conditions in an experiment: the independent and the dependent, or response, variable. The independent variable is directly manipulated or controlled by the scientist and is generally what one predicts will affect the dependent variable. The dependent, or response, variable thus depends on the value of the independent variable. Experiments are generally designed so that one specific factor is manipulated in the experiment in order to illuminate cause and effect relationships.</p>
<p>An everyday example: Does the car still have all of its parts? Is this the right key? What does the gas gauge say? Does a jump start help?</p>
<p>Another important aspect in experimental design is the role of the control treatment, which represents a non-manipulated treatment condition. The control treatment is kept in the same conditions as the experimental treatment, but the experimental manipulation is not applied to the control. For example, if a researcher were testing the effects of soil salinity on plant growth, the soil in the control treatment would have no added salt. The control provides a baseline of &#8220;normal&#8221; conditions with which to compare the experimental treatments.</p>
<p>Experimental design should also incorporate replicates of each treatment. Repeatability of experimental results is an important part of the scientific method that ensures the validity and accuracy of data. It is quite difficult to control all aspects of an experiment so there is inherent variation in results that cannot be controlled for even under the most carefully designed and controlled experiments. Having replicates enables an investigator to estimate this inherent variation in results. Precise recording and measurement of data is also of great importance for ensuring the accuracy of results and the conclusions one draws from the results.</p>
<h4>Step 4: Results and Data Analysis</h4>
<p>The next step in the scientific method involves determining what the results from the experiment mean. Scientists compare the predictions of their null hypothesis to that of their alternative hypothesis to determine if they are able to reject the null hypothesis. Rejecting the null hypothesis means that there is a significant probability that values of the dependent variable in the control versus experimental treatments are not equal to each other. If significant differences exist, then one can reject the null hypothesis and accept the alternative hypothesis. Conversely, the investigator may fail to reject the null hypothesis, meaning the treatment has no effect on the results. Before scientists can make any claims about their null hypothesis from their experimental data or observations, statistical tests are required to ensure the validity of the data and further interpretation of the data. Statistical tests allow researchers to determine if there are genuine differences between the control and experimental treatments. From there, they can create figures and tables to illustrate their findings.</p>
<h4>Step 5: Conclusions</h4>
<p>The last portion of the scientific method involves providing explanations of the results and the conclusions that can be logically drawn from the results. Generally, this step of the scientific process also requires one to revisit scientific literature and compare their results with other experiments or observations on related topics. This allows researchers to put their experiment in a more general context and elaborate on the significance of particular results. Additionally, it allows them to explain how their work fits into a larger context in their discipline.</p>
<p>The scientific process does not stop here! The scientific process works through time as knowledge on topics in science accumulate and drive our understanding of particular mechanisms or processes explaining natural phenomena. If we fail to reject our null hypothesis, then it becomes necessary to revisit the initial stages of the scientific method and try to reformulate our questions and understand why an anticipated result was not attained.</p>
<h4>Application of the Scientific Method</h4>
<p>The only difference between the use of this method in every-day life and in the laboratory is that scientists carefully document their work, from observation to hypothesis to experiment, and finally conclusions and peer review. In addition, unlike problem solving outside the lab, the scientific method in the lab includes controlled conditions and variables.</p>
<p>Let&#8217;s investigate the scientific method using an example from the lab. It is known that plant growth is affected by microbes, such as bacteria and fungi, living in their soil. It is possible to figure out what microbes have which effects by potting plants in completely sterile soil, then adding in microbes one at a time, or in different combinations and measuring the growth of the plant. Now let&#8217;s fit this into the terms used to describe the scientific method:</p>
<p><strong>Observation and Question</strong>: There are microbes in the soil&#8230;do these affect plant growth?</p>
<p>HYPOTHESES:</p>
<p>Experimental: One particular microbe of interest will cause the plants to grow more slowly.</p>
<p>Null: The presence or absence of microbes will have no effect on plant growth</p>
<p><strong>Experiment</strong>: set up groups of plants in 1) sterile soil, 2) soil with the microbe added in, and 3) natural soil. Measure the growth of the plants over time, using a ruler.</p>
<p><strong>Conclusion</strong>: if the plants in group 2 grow more slowly than the other two, the hypothesis is supported. This needs to be backed up with statistical analysis from many plants to be considered significant. An experiment like this is not legitimate with just one plant per group.</p>
<p>Group 1 is a<strong> control</strong> which shows the plants can grow in the sterile soil. Group 3 is a control that shows the plants can grow under normal conditions. Group 2 is the experimental group. It would be possible to add different amounts of the microbe, or different microbes, to introduce more variables. The main point is that the researcher has something to which to compare the experimental group- the control group. If the experiment included only group 2 and the researcher determined that the plants &#8220;looked sick,&#8221; that would be a matter of opinion. The only way to make that observation scientific is to have healthy plants to measure. The type or amount of microbe used is the <strong>independent variable</strong>, because the researcher has control over it. The size of the plant at the end of the experiment is the <strong>dependent or response variable</strong> because it is the result.</p>
<p>Ultimately, work like this is published in scientific journals so that other researchers can read about the methods used and conclusions drawn. Publications like this are subject to peer-review, which means that an article won&#8217;t be published in a journal until other researchers have checked it out and agree it is well-done. As a community of scientists, general concepts are developed based on observed patterns in the experiments that individual scientists conduct. This results in the development of a scientific <strong>theory</strong>. This term means that there is a consensus among researchers that a particular concept or process exists. It is important to note that the word theory does not mean the same thing as hypothesis. Once scientists label a concept with this term, it is considered to be true, considering all currently available data. Of course, if a large body of experimentation demonstrates information to the contrary, theories can be modified.</p>

Scientific Method: Steps and Applications - Concept

科学的方法

The scientific method is used to solve problems and explain phenomena. The development of the scientific method coincided with changes in philosophy ...

Education

JoVE Lab Manual

生物学

基礎

Group Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">The Hawk-Dove Game
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe hypothetical costs and benefits of the antagonist or cooperative behavior respectively. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Before the activity starts, review the cost-benefit table so that you understand how to score the game. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/33/Table_1_Group_behavior.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">HYPOTHESES: The experimental hypothesis for this exercise could be that the dove strategy will become more frequent between repeated partners, and the hawk strategy will become more frequent when interactions are with a variety of partners. The null hypothesis could be that there will be no change in strategy over time with repeat or different partner combinations. NOTE: Benefit can be determined by looking at the left column and choosing the row that corresponds to the card you played. The box that corresponds to the choice of your partner can be found in the top row. For the purposes of this game, B equals four and C equals three. So depending on the cards played, player one here, which is you, would gain a score of two, four, zero or one half. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Collect a set of two game cards. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Take out the cards labeled hawk and dove and place them face down on the table or conceal them in your hands. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">When the instructor gives the signal show either of the two cards to the student sitting across from you. Try to strategize how to receive the highest benefit from every interaction on your own but do not communicate with your partner. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the Single Partner Recording Table (Table 2) provided by your instructor, note the cards played as well as the benefit you received for that round.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Repeat showing cards to the same partner and determining benefit on your instructor&#39;s signal for a total of 15 rounds.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">At the end of those rounds, the student with the highest total benefit value was determined to be the &#8220;winner&#8221;, or the most fit.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">As a class, determine the percentages of hawks and doves played as well as the average benefit received for each round, using this formula: Class average benefit=(sum total benefit)/(number of players)
</div></li><li data-sub-note-item="1-11"><div class="lab-step">For the second game, and then for each round of play, one row of students should rotate to their right, leaving all players with a new partner.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Continue playing for 15 rounds or until students end up back in their starting positions, recording the data in the Multiple Partner Recording Table (Table 3) given to you by your instructor.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">For each round, determine the percentages of hawks and doves played that round, as well as the average benefit received.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Cheating and Cooperation Exercise
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">NOTE: In this activity, you will exchange benefits, represented by colored or similar items, with your classmates. In this simulation, a cheater is defined as a person who gives fewer benefits than they receive. During this activity, you will observe the frequency of cheating behavior over time. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">HYPOTHESES: The experimental hypothesis is that cheaters will receive fewer benefits over time and cooperators will continue to provide equal benefits to one another. The null hypothesis is that the frequency of cheaters and cooperators does not change over time. 
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Each person should collect beads of one color to represent a tangible benefit, as well as one paper bag and a three-ring binder.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Get into a group of three so that all members have objects of the same color.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Now find another group with a different color to pair with. In each round, partners will exchange benefits without knowing what they are receiving from their partner and without discussion within their group.  NOTE: Benefits of a different color from your starting color are worth twice as much.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Turn face to face with a member from the other group while still being able to conceal the objects in your possession.  TIP:<strong> </strong>Setting up a screen using a notebook or sitting behind a desk can be helpful here.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When given a signal from the instructor, place zero to two benefits into the paper bag and pass it to your partner.
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Simultaneously, receive the bag from your partner and then remove the benefits from the bag.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Make a note of how many benefits you gave away and how many you received in the Cheating and Cooperation Table (Table 4) provided by your instructor.
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Turn to a new member from the other group and repeat the exchange.
</div></li><li data-sub-note-item="2-11"><div class="lab-step">Rotate through all of the members of the other group for as many rounds as the instructor determines - which will not be revealed until the game ends so as not to alter player behavior.
</div></li><li data-sub-note-item="2-12"><div class="lab-step">Once the game has ended, note for each round in the cheating and cooperation table whether you gave more than your partner, received more from them or if you gave the same amount.
</div></li><li data-sub-note-item="2-13"><div class="lab-step">Now total up all of the benefits in your possession, with benefits you&#39;ve received from the other group being worth twice as much.
</div></li><li data-sub-note-item="2-14"><div class="lab-step">For each round, the whole class should total up the number of cheaters - with cheaters defined as those who gave less than they received.
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">For both the single partner hawk-dove game and the multiple partners hawk-dove game, use the whole class data to plot the percentages as two separate lines - one for the percentage of hawks, and one for the percentage of doves, for each of the 15 rounds.
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Take note of whether the cards played changed as more rounds were played.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Manipulate the values for B and C to see if you can find the point at which values of B and C would render the hawk strategy no longer effective (this would be the point when there is no benefit to choosing the hawk strategy over always choosing the dove strategy).
</div></li><li data-sub-note-item="3-4"><div class="lab-step">As a class, use the data from the cheating and cooperation activity to make a graph showing the percentage of rounds each individual player cheated versus the amount of benefits they ended with.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">Consider whether it is better to be a cheater or a cooperator in this scenario and discuss as a class what makes this scenario different from the hawk-dove game.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Now, use the class data to graph the percentage of cheaters against the number of rounds, and look for any trends over time.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Consider which type of strategy would most likely evolve in a setting where partners interact repeatedly.
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Then, note which tactic might be beneficial for a species that relies on cooperation. 
</div></li><li data-sub-note-item="3-9"><div class="lab-step">Discuss as a class what would likely happen if you increased or decreased the relative value of the benefits you receive.
</div></li></ul></li></ol>

Group Behavior: Hawk-Dove Game and Trading Exercise - Procedure

グループの動作

The Hawk-Dove Game
ExpandNOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe ...

生態学

Lab Manual Sub Articles

Optimal Foraging

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Foraging with Artificial Habitats and Prey
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with varying prey densities. Without knowing what these densities are, foragers must obtain as many prey items as possible in as little time as possible. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">HYPOTHESES: In this experiment, the experimental hypothesis could be that foragers will catch the most prey in the higher prey density bucket and also spend the most time foraging there.  The null hypothesis would then be that foragers will catch an equal number of prey in each bucket and that foragers will spend an equal amount of time foraging in each patch. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">To begin the foraging activity, record the names and role of each participant at the top of the student data collection sheet.  NOTE: Before starting the experiment, the forager is allowed to become familiar with the foraging process &#8211; the following steps are a practice round. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">The forager should kneel or sit in front of the average density bucket. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Once the timer says start, the forager may begin looking for the pinto beans representing the prey. The forager can spend as much time as they like foraging in this bucket. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Once a prey item is located, the forager must signal that one has been found and place the prey in the cup next to the bucket.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Once they believe they have acquired most of the prey in the patch, they should tell the timer to stop the time and the practice round is over. 
</div></li><li data-sub-note-item="1-8"><div class="lab-step">To begin the simulation proper, the forager should sit or kneel in front of bucket A. 
</div></li><li data-sub-note-item="1-9"><div class="lab-step">The timer must be ready to start the stopwatch. 
</div></li><li data-sub-note-item="1-10"><div class="lab-step">The recorder should be ready to record the time each prey item is located, in addition to the time that the forager arrived at and left each bucket. 
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When all parties are ready, the timer should start the stopwatch and say &#8220;start&#8221;,  and the forager should begin foraging. NOTE: The stopwatch will run through the rest of the round for buckets B and C.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">As the forager signals finding pinto beans and places them in the cup next to the bucket, the timer should tell the recorder the time.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">The recorder should then write the time in the student data collection sheet.  <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/34/Table_1_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Once the forager has decided to move on to the next bucket, they should tell the timer &#8220;done&#8221;, and begin moving to the next patch. 
</div></li><li data-sub-note-item="1-15"><div class="lab-step">The recorder should record the time the forager left and the time they arrived at bucket B in the student data collection sheet.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Repeat the same procedure for buckets B and C. Once the forager has completed the activity, it is time for the next forager to begin using the same procedure. 
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Before performing any data analysis, review the data collection sheet and compile your individual data for captured prey, foraging time, and travel time for each bucket in your student calculations table. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/34/Table_2_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-2"><div class="lab-step">After this, calculate your individual capture rate for each bucket by dividing the number of prey captured by the sum of the foraging time and travel time and record these values in your table. Individual capture rate =  Number of prey captured / (foraging time + travel time)
</div></li><li data-sub-note-item="2-3"><div class="lab-step">To calculate your Giving-Up-Time or a GUT for each bucket, subtract the time that the last prey item was acquired from the time you left the bucket.  GUT = time forager left bucket  -  time last prey item acquired
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Next, calculate the mean GUT for your foraging group and record the values in your table.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Finally, calculate your scaled GUT for each bucket by dividing the bucket GUT by your group&#39;s mean GUT. Scaled GUT =  Bucket GUT / Group mean GUT NOTE: The scaled GUT will allow class data to be pooled later on without differences in individual foragers skewing the data. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">The instructor should now compile the data into the classroom spreadsheet.  <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/34/Table_3_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Plot a bar graph of the average number of prey collected in each bucket. On the x-axis, A should represent the low prey density bucket, B should represent the medium prey density bucket, and C the high prey density bucket. Plot the y-axis as the number of prey items caught. 
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Next, plot the graph of the class average scaled GUT, where the x-axis represents the buckets with varying levels of prey density and the y-axis shows the values for the average scaled GUT. 
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Plot a third graph of the average time spent foraging in each bucket. 
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Now review the Marginal Value Theorem (MVT) from the concepts video and examine the three graphs that you generated from your class data. Take note of whether the graphs conform to the predictions of MVT. 
</div></li></ul></li></ol>

Optimal Foraging: Foraging with Artificial Habitats and Prey - Procedure

最適な採餌

Simulating Foraging with Artificial Habitats and Prey
ExpandNOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with ...

Species Distribution and Biogeography

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Colonization and Extinction on Islands
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Form groups of three. One member of the group will simulate colonization by throwing balls into the groups of cups representing the islands. Another will simulate extinction by rolling dice to randomly remove balls from the cups. The third group member will record the data.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Take time to familiarize yourself with the four island stations. NOTE: There are two large islands with 12 cups and two small islands with 6 cups. Two of the stations will have tape lines that are 2 m away from the cups. These are the far islands. The other two stations will have tape lines that are 1 m away from the cups. These are the near islands. Thus, the stations are far large and near large and far small and near small. HYPOTHESES: In this experiment, one alternate hypothesis might be that the larger islands with more cups will support a greater number of species than the smaller islands. The null hypothesis might be that all islands will support this same number of species regardless of size. Another alternate hypothesis might be that islands closer to the mainland will have a higher colonization rate than islands farther from the mainland. The null hypothesis might be that all islands will have the same colonization rate regardless of their distance from the mainland. Additionally, in all trials we may hypothesize that the colonization rate will be expected to decrease as more species inhabit an island whereas the extinction rate will increase as more species are found on the island. The null hypothesis might be that the colonization rate and extinction rates are expected to stay the same across all numbers of species on the island.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">First, choose one of the four stations as a starting place.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">From the line of tape at this location, the colonization simulator must throw the ball to the island and try to get the ball into a cup. NOTE: One round consists of five throws, each throw representing a colonization attempt. If the ball lands in a cup that does not already have a ball in it, this is a successful colonization attempt and the ball should be left in the cup.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">The data collector should place a tally on the colonizers box for the round in the recording sheet found at the station. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/29/Tables_1-4_Island_biogeography.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Tables 1-4</a>
</div></li><li data-sub-note-item="1-6"><div class="lab-step">If the ball does not land in a cup, retrieve it. This is an unsuccessful colonization attempt.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">If a ball lands in a cup that already has a ball in it, retrieve it. This is also an unsuccessful colonization attempt.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Add the number of species at the beginning of the round with the tally of colonizers.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">The data collector should record this number in the column entitled &#8220;Number of species after colonization&#8221; in the recording sheet found at the station.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">The extinction simulator should now roll a die. If the trial is occurring at a large island site, choose one of the two colored dice at random with eyes closed.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Remove the ball if there is one present from the cup that is of the same color as the die and labeled with the number rolled by that die.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">The data collector should count the removal as an extinction in the station recording table. NOTE: In a trial at the small island station, follow the same procedure except that it is only necessary to match the number rolled by the die to the cup. If there is no ball in the cup, no extinction is recorded. For both the large and small islands, repeat the extinction roll for a total of two rolls if there are 3 - 8 species present on the island and three rolls if there are 9 - 12 species on the island. If there are fewer than three species on the island, do not roll the die again.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">This is the end of one round. After this, count the total number of species currently in the cups at this station and then tally this number into the &#8220;Number of species at beginning of round&#8221; column on the station recording sheet for the next round.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Groups should switch stations after five rounds at one table to control for the throwing ability of the colonization simulators. Repeat the trials and rotation through the stations until 20 rounds have been recorded in total for all groups combined at all four stations.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Count the tally marks for the number of species at the beginning of the round, colonizers, total number of species after colonization, and extinctions for each round at each island station.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Look at your data recording sheet. How many times were there zero species at the beginning of a round? How many times was there only one species at the beginning of a round? Repeat this calculation for 0 through 12 species present at the beginning of a round.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Then, tally these values in the corresponding rows of the &#8220;Rounds with this many species&#8221; column in the appropriate colonization rate calculation table. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/29/Tables_5-8_Island_biogeography.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Tables 5-8</a>
</div></li><li data-sub-note-item="1-18"><div class="lab-step">In the colonization attempts column, multiply these values by five to represent the total number of Ping-Pong balls thrown.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">Look at your data recording sheet once more and calculate the total number of colonizers for each value in the number of species at beginning of round column.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Record these values in the &#8220;Successful colonization attempts&#8221; column of the appropriate colonization rate calculation table.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Divide the successful colonization attempts by the colonization attempts for each initial species value and record this in the &#8220;Colonization rate&#8221; column of the appropriate colonization rate calculation table.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Repeat the process for determining the colonization rate for all of the island trials. 
</div></li><li data-sub-note-item="1-23"><div class="lab-step">To calculate the extinction rate for each of the trials, return to the data recording sheet for the near large island trial. Count the number of times that the number of species after colonization matched each number from 1 to 12, as previously described.
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Record these values in the &#8220;Rounds with this many species&#8221; column in the appropriate extinction rate calculation table. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/29/Tables_9-12_Island_biogeography.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Tables 9-12</a>
</div></li><li data-sub-note-item="1-25"><div class="lab-step">To calculate extinction attempts, multiply the value in the &#8220;Rounds with this many species&#8221; cells by 1 if the species after colonization value is 0 &#8211; 2, by 2 if the value is 3 &#8211; 8, and by 3 if the value is 9 or above. NOTE: These values correspond with the number of times the die was rolled during the extinction simulation.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">Then, using the data contained in the data recording sheet, count the number of extinctions that occurred for each value in the &#8220;Number of species after colonization&#8221; column.
</div></li><li data-sub-note-item="1-27"><div class="lab-step">Record these values in the &#8220;Extinctions&#8221; column of the appropriate extinction rate calculation table.
</div></li><li data-sub-note-item="1-28"><div class="lab-step">Record these values in the &#8220;Extinctions&#8221; column of the appropriate extinction rate calculation table.
</div></li><li data-sub-note-item="1-29"><div class="lab-step">Repeat the process for calculating the extinction rate for all of the island trials. 
</div></li><li data-sub-note-item="1-30"><div class="lab-step">After this, plot the colonization and extinction rates versus the number of species for each of the island stations.
</div></li><li data-sub-note-item="1-31"><div class="lab-step">Draw the best-fit lines for the colonization and extinction rates in each of the four graphs.
</div></li><li data-sub-note-item="1-32"><div class="lab-step">Compare the colonization rate between the near and far islands. Determine the distance that had a greater dynamic equilibrium of species and develop a hypothesis to explain your observation. 
</div></li><li data-sub-note-item="1-33"><div class="lab-step">Next, compare the extinction rates between the large and small islands. Determine the size that had a greater dynamic equilibrium number of species.
</div></li><li data-sub-note-item="1-34"><div class="lab-step">Observe the slopes of the colonization rates in the plots. Determine if they are positive or negative. 
</div></li><li data-sub-note-item="1-35"><div class="lab-step">Observe the slopes of the extinction rates in the plots. Determine if they are positive or negative. 
</div></li></ul></li></ol>

種の分布と生物地理学

Simulating Colonization and Extinction on Islands
ExpandForm groups of three. One member of the group will simulate colonization by throwing balls into ...

Extinction

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Diversity and Extinction during the Paleogene Epoch
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Begin this procedure by reading the extinction reading supplement that has been printed out for you. <br /><strong>NOTE:</strong> Alternatively, you may download the reading supplement at the link below.&nbsp; <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/24/Lab_20_Reading Supplement.docx" style="display:block;margin:20px;" target="_blank">Click here to download the extinction reading supplement</a>
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Using the information contained in the extinction reading supplements pertaining to the taxa of interest and the Chicxulub impact event, make predictions for each taxon listed in Table 1. Consider whether diversity in each taxon increased, decreased, or stayed the same immediately following the Cretaceous-Paleogene boundary and later on in the Paleogene epoch. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/24/Table_1_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, fill out the reasons for each of your predictions in the Contributing Factors column. HYPOTHESES: The experimental hypothesis is that many of the different taxa will show changes in diversity after the Cretaceous-Paleogene event, and again at the end of the Paleogene, with some increasing in diversity, while others decrease. The null hypothesis is that there will be no changes in diversity between taxa following the Cretaceous-Paleogene event, or at the end of the Paleogene.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Gather diversity data by going to the Paleobiology Database: <a href="http://www.paleobiodb.org" target="_blank">www.paleobiodb.org</a>.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">In the center of the screen, click the yellow box labeled Download Data. Under the italicized heading, &#8220;What do you want to download?&#8221;, select Diversity over time on the left side and Comma-separated values on the right side.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Scroll down to the heading &#8220;Select by taxonomy&#8221;.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the first box labeled 'Taxon or taxa to include', type in the name of the taxon that data is being gathered on.  NOTE: Ensure the spelling is correct.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Now, go to the dropdown menu right below that box labeled &#8220;Taxonomic resolution&#8221;, and select genera.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Under the next heading, Select by time, type Maastrichtian into the first box and Chattian in the box directly below. Make sure the dropdown menu labeled Time rule is set to major and the Temporal resolution is set to stage.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Select &#8220;Assume extant taxa range through to present&#8221;. Scroll back up to the middle of the page and click download. A save window will open.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Save the .csv file to a safe and accessible place and rename it to make it easy to identify.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Open the file and scroll down to the main dataset under Records.  NOTE: The data are arranged in reverse time order by geological stage. The second column, interval_name, gives the accepted name of the stage in question. The next two columns give the appropriate dates of the stage in millions of years before the present. The final column, number of occurrences, gives a total count of the genera extant during that geological stage as determined from occurrence of fossils.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">To more easily work with this data, copy and paste each column into a new sheet. Be sure to label this sheet with the taxon in question, the data and time the data were obtained, and the data source.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Repeat this process for each of the taxa in Table 1 (steps 4 &#8211; 12). NOTE: Data from multiple taxa can be kept on the same sheet, so long as they are kept distinct and labeled appropriately.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">To create line plots for each of the taxa showing the change in diversity over time, select the max_ma column and the number of occurrences column simultaneously.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">In Excel, select Insert from the top toolbar and find the section labeled Charts. Select the bottom center icon, Insert Scatter Chart.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Then, select the Scatter with Straight Lines and Markers and a graph should appear. NOTE: Since the axis of this graph is in units of millions of years ago, the axis is in the reverse direction of time when put in numerical order.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">To fix this, click on the green plus sign in the top-right corner of the graph and hover over Axes. This should reveal a small black arrow. Click the arrow to open up a small menu and select More Options.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">This will open the Axis Options menu. Under Axis Options, click the box next to Values in reverse order. NOTE: It is also possible to change the axis scales from this menu, which can be used to eliminate the excess time that is not being analyzed in this lab. Keep any changes consistent between different graphs.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Double-click on the title at the top of the graph and change it to the taxon being represented.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Make a separate graph for each of the taxa in Table 1. Keep them organized and in one location. A separate sheet for graphs is recommended.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">For each graph, identify the location of the Cretaceous-Paleogene boundary and draw a vertical line through the graph at this point.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Using the information from the graphs, fill out Table 2. In some cases, it may be helpful to go back to the original dataset and compare actual values, particularly when they are small. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/24/Table_2_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare these values to the predictions made in Table 1 and discuss if the original contributing factors are still likely candidates.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Using the dataset, calculate the percentage of total taxa that went extinct over the Cretaceous-Paleogene boundary using this equation.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">There is an event in the middle of the Paleogene known as the Paleocene-Eocene Thermal Maximum about 55.5 million years ago. This represents a high point in temperature during the Paleogene epoch at approximately 8 &#176;C higher than today&#39;s average temperature. Does this point seem to have an effect on diversity for any of the taxa? If yes, then which ones?
</div></li></ul></li></ol>

Extinction: Diversity and Extinction during the Paleogene Epoch - Procedure

絶滅

Diversity and Extinction during the Paleogene Epoch
ExpandBegin this procedure by reading the extinction reading supplement that has been printed out for ...

Animal Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Making Choice Chambers
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Before beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the bottom of both bottles. One line should be 1 cm from the base of the bottle and the other should be 1.5 cm from the base of the bottle.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Use a razor blade to make a small cut in each bottle at the mark. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, insert the scissors and carefully cut along the line until the bottoms of the bottles are removed completely.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Fit one bottle bottom into the other.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Tape the bottles together to make a secure chamber.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Use the razor blade and scissors to poke a hole into the center of the chamber. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Take a piece of tape and fold the edge onto itself to make a tab and place the tape over the hole.  Note: The tab helps with easy removal and reattachment of the tape to the chamber.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Use the Sharpie to label one side of the chamber A and the other side B.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Upon receiving the colony of <em>Drosophila</em>, perform a count to make sure there are 40 living individuals in the vial.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Geotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To perform a geotaxis assay, first attach a clean, empty bottle cap to each end of the choice chamber and turn the fly vial upside down onto its lid.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Open the tape flap in the center of the choice chamber.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Insert the funnel into the hole and tap all of the flies into the chamber. HYPOTHESES: The alternate hypothesis is that more flies will be moving against gravity, or up, regardless of the orientation of the choice chamber. Alternatively, if the flies are positively geotactic, then more flies will move down, or with gravity. The null hypothesis is that the flies will have no preference with regard to gravity and will move randomly within the chamber. 
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Once the <em>Drosophila</em> are in the chamber, close the tape flap, rotate the chamber so that it stands vertically with side A on the bottom, and start the timer.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Immediately, count the number of <em>Drosophila</em> that are moving up and the number that are moving down. Record these data for time point 0 in the table. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">After 30 seconds, rotate the chamber so that side B is on the bottom and count the number of <em>Drosophila</em> that are moving up or down. Record these data for time point 30 in the table.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">After 60 seconds, rotate the chamber so that side A is on the bottom again and record the number of moving flies for time point 60.  <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/15/Table_1_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Hold the chamber over the fly vial and carefully open the cap to return all of the <em>Drosophila</em> back to their empty vial. 
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Phototaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">To perform a phototaxis analysis, first cover side A of the choice chamber with tin foil, taking care that the foil reaches to the exact center between the two sides. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Ensure the caps are secured on both ends of the chamber.  HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found in the light side of the choice chamber, if the flues are attracted to light, or on the dark side if they are repelled by light. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus. Therefore, equal numbers of flies will be found on either side of the choice chamber.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Open the tape flap in the center of the choice chamber, insert the funnel into the hole, and tap all 40 flies into the chamber as previously described.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Set the timer to sound an alarm at 10 minutes.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">When the alarm sounds, stop the timer, and count the number of flies in the open side B of the chamber.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Subtract that number from the total number of flies added to the choice chamber to calculate the number of flies in the covered side A.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Record these data in the table for time point 10.  <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/15/Table_2_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Carefully, return all of the flies back to their empty vial.
</div></li></ul></li><li data-note-item="4" data-parent-collapse="">Chemotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="4-1"><div class="lab-step">HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found on the side of the chamber with the apple cider vinegar if the flies are attracted to the odor. Or, if the flies are repelled by the vinegar, then more of them will be found on the side of the chamber presenting the odorless water. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus and will move randomly in the chamber.  Use an individual disposable plastic pipette to dispense two drops of the apple cider vinegar onto one cotton ball for side A of the chamber. 
</div></li><li data-sub-note-item="4-2"><div class="lab-step">Use an individual disposable plastic pipette to dispense two drops of the distilled water onto a cotton ball for side B of the chamber. 
</div></li><li data-sub-note-item="4-3"><div class="lab-step">Fold two pieces of tape over themselves to create individual pieces of double-sided tape and use the tape to attach each cotton ball to the inside of the single bottle cap.
</div></li><li data-sub-note-item="4-4"><div class="lab-step">Screw the bottle caps with the cotton balls onto their corresponding sides of the chamber.
</div></li><li data-sub-note-item="4-5"><div class="lab-step">Transfer all of the flies into the chamber and set the timer to sound an alarm after 10 minutes. 
</div></li><li data-sub-note-item="4-6"><div class="lab-step">When the alarm sounds, stop the timer and record the number of flies in each side of the chamber. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/15/Table_3_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="4-7"><div class="lab-step">At the end of the final experiment, funnel the flies into a morgue tube containing 70% ethanol. 
</div></li><li data-sub-note-item="4-8"><div class="lab-step">Dismantle the choice chambers for recycling.  NOTE: Since all of the chemicals used in these experiments are lab safe, the liquids can be disposed of down the sink, the chambers rinsed, and the solids can be thrown away in the trash. 
</div></li></ul></li><li data-note-item="5" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="5-1"><div class="lab-step">Gather all of the data collected for the geotaxis, phototaxis, and chemotaxis experiments.
</div></li><li data-sub-note-item="5-2"><div class="lab-step">Plot these values as bar graphs for different conditions and different time points.
</div></li><li data-sub-note-item="5-3"><div class="lab-step">Use these data to draw inferences about the behavior of <em>drosophila melanogaster</em>. 
</div></li></ul></li></ol>

Animal Behavior: Studying Taxis Behavior of Drosophila - Procedure

動物の行動

Making Choice Chambers
ExpandBefore beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the ...

Sexual Selection and Mate Choice

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Sexual Selection Class Simulation
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Note: In this activity, you and your classmates will portray a sexually reproducing population consisting of an equal number of male and female animals. You will simulate several different mating scenarios to determine how relative quality, attractiveness, sex, and parental commitment affect mate choice and reproductive success. The goal of this activity is to maximize your progeny. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Hypotheses: There are several overall hypotheses for female and male behavior for this activity. The main experimental hypothesis for female behavior is that females will mate with males of high quality more frequently than those of low quality, yielding a higher reproductive success. The null hypothesis is that females will not demonstrate preference towards high- or low-quality males in any of the four rounds of mating. For males, one experimental hypothesis is that males with a higher visible score will have greater reproductive success. Another could be that males will be more selective for females in scenarios in which they join females to care for offspring as opposed to scenarios in which they exhibit no parental commitment. The null hypothesis for male behavior might be that males will not demonstrate preference towards high- or low-quality females in any of the four rounds of mating. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Activity Overview: To begin, each student will be assigned a sex as well as a relative quality and attractiveness score. Remember - the goal is to maximize your reproductive success in each round. You do this by mating with partners of the highest possible quality which is rated on a scale of one to three with three being the highest possible score. Attractiveness scores, which follow the previously described scoring paradigm, correlate with quality but do not exactly predict the score. Though useful, they are not a perfect way to choose the best mate.  If you are assigned a male ID holder, you will have 16 gametes. However, if you are assigned a female ID holder, you will only have four. A successful mating occurs when one sperm and one egg are paper-clipped together and deposited at the fertilization area. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Note - Rules of the activity: 
<ul>
	<li>Assigned male and female identities for these experiments are not representative of students&#39; personal gender identities. </li>
	<li>Running is not permitted. </li>
	<li>Talking is not permitted.</li>
	<li>Hidden values cannot be shared but individuals can attempt to hide their visible scores. </li>
	<li>Respect the space around each individual and remain an arm&#39;s length away. </li>
	<li>Offspring will only be counted towards an individual score if both gametes are paper-clipped together and dropped off in the designated fertilization area before the end of the two-minute round. </li>
</ul>
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Round 1 &#8211; Hidden Quality Score
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To begin the first simulation, take the clip-on ID holder you were randomly assigned and make sure it contains four gametes if you are assigned female or sixteen gametes if male. Males should also have a strip of white paper and two paperclips. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Next, males should paperclip the white strip of paper over their quality score to hide it, but keep the attractiveness score visible. 
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Record your ID number for round one in table two.  <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/35/Table_2_sexual_selection.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Next, clip on the ID holder and move to the designated mating area. 
</div></li><li data-sub-note-item="2-5"><div class="lab-step">When the instructor says begin, you may commence the mating simulation. You will have exactly two minutes to produce as many offspring as possible. Males may freely give their sperm to females, and females may choose to use these sperm immediately after which they would walk to the fertilization area and paperclip it to one of their eggs, or they may choose to wait until they receive other sperm to do so. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Once the gametes have been deposited in the fertilization area, females may resume mating. 
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When the two minutes have elapsed, all matings must stop and any gametes not in the fertilization area at this time will not be counted. 
</div></li><li data-sub-note-item="2-8"><div class="lab-step">The instructor should now tally all of the matings and record the numbers of the individuals who produced each offspring.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Now, find all the gametes that came with your ID holder and repackage them for the next round. 
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Round 2 &#8211; Hidden Attractiveness Score
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">For the second round, obtain a new randomly assigned ID holder and again ensure it contains the proper number of gametes. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Next, males should use the paperclip and strip of white paper to hide their attractiveness score (instead of the quality score, which was covered in round one).
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Record the ID number of your clip in table two under round two.  Note: The mating simulation process for round two will be the same as round one.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Move to the designated mating area and with for the instructor to signal the start of the round. As before, males may freely give away their sperm while females will choose to use it now or wait for different sperm. When a female decides to fertilize an egg, she will walk to the fertilization area and paperclip the gametes together. 
</div></li><li data-sub-note-item="3-5"><div class="lab-step">Proceed with the simulation for two minutes, and at the signal from the instructor all mating activity should stop. 
</div></li><li data-sub-note-item="3-6"><div class="lab-step">The instructor should now tally all of the matings from this second round.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Now, find and return the gametes to your ID holder, and then return the holder to the instructor.
</div></li></ul></li><li data-note-item="4" data-parent-collapse="">Round 3 &#8211; Visible Quality and Attractiveness Scores
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="4-1"><div class="lab-step">For the third simulation, you should again obtain a new clip-on ID holder and check that it contains the appropriate number of gametes. Record the ID number of your clip in table two.
</div></li><li data-sub-note-item="4-2"><div class="lab-step">For this round, leave both attractiveness and quality scores visible on male IDs. Note: The mating simulation process for round three will be the same as the previous two rounds.
</div></li><li data-sub-note-item="4-3"><div class="lab-step">Move to the mating area and wait for the signal to begin the simulation.
</div></li><li data-sub-note-item="4-4"><div class="lab-step">Once the instructor starts the timer and gives the signal, commence mating. As before, males are allowed to freely give away their sperm to females and females may use the sperm immediately or wait for different sperm. Again, fertilized eggs only count if placed in the fertilization area. 
</div></li><li data-sub-note-item="4-5"><div class="lab-step">After the two-minute time limit, the instructor should tally all matings. 
</div></li><li data-sub-note-item="4-6"><div class="lab-step">Now, find and return the gametes to your ID holder, and then return the holder to the instructor.
</div></li></ul></li><li data-note-item="5" data-parent-collapse="">Round 4 &#8211; Increased Male Parental Care
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="5-1"><div class="lab-step">In the final round, males will again leave their attractiveness and quality scores visible. 
</div></li><li data-sub-note-item="5-2"><div class="lab-step">Obtain an ID holder and ensure it contains the appropriate number of gametes. 
</div></li><li data-sub-note-item="5-3"><div class="lab-step">Clip on the ID holder and move to the mating area. Note: As before, males may freely give away their sperm to females. However, in this round, once a female chooses to mate with a male, both the male and female will walk to the fertilization area to paperclip their gametes together. After placing the paper-clipped gametes on the table, both male and female actors may return to the mating area. 
</div></li><li data-sub-note-item="5-4"><div class="lab-step">The instructor should signal the start of the round and begin the timer &#8211; at this point participants can begin the simulation.
</div></li><li data-sub-note-item="5-5"><div class="lab-step">Once the two-minute time limit is up, all matings must stop. 
</div></li><li data-sub-note-item="5-6"><div class="lab-step">The instructor should tally all mating events.
</div></li><li data-sub-note-item="5-7"><div class="lab-step">Find and return the gametes to your ID holder. Give your ID holder to the instructor and notify them if any gametes or supplies are missing. 
</div></li></ul></li><li data-note-item="6" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="6-1"><div class="lab-step">To analyze the data generated during the mating activities, first split up into groups of four. 
</div></li><li data-sub-note-item="6-2"><div class="lab-step">Collect the class data from the instructor for ONE of the four rounds of mating. Note: In this activity, there were several types of females and males distinguished by different letters. These letter types correspond to specific combinations of quality and attractiveness scores. In the compiled data, the average number of matings and reproductive success has already been sorted by letter type for you by the instructor. 
</div></li><li data-sub-note-item="6-3"><div class="lab-step">Use these data to generate four graphs for the round you were assigned. First plot two graphs for the average number of matings against female and male type. 
</div></li><li data-sub-note-item="6-4"><div class="lab-step">Then plot the reproductive success for males and females against male or female type, giving a total of four graphs.
</div></li><li data-sub-note-item="6-5"><div class="lab-step">Once these graphs are complete, each group should present their data to the class, making sure to state the original hypothesis for your assigned round and whether or not the hypothesis was upheld.
</div></li><li data-sub-note-item="6-6"><div class="lab-step">After each group presents, discuss the overall results of the four rounds together. 
</div></li><li data-sub-note-item="6-7"><div class="lab-step">Note the affect that hiding the quality score had on the overall quality of mates chosen.
</div></li><li data-sub-note-item="6-8"><div class="lab-step">Note how hiding or revealing the attractiveness score affected the results.
</div></li><li data-sub-note-item="6-9"><div class="lab-step">Discuss the effect of male parental investment on the number and overall quality of mating pairs.
</div></li></ul></li></ol>

性選択と配偶者選択

Sexual Selection Class Simulation
ExpandNote: In this activity, you and your classmates will portray a sexually reproducing population consisting of an ...

Genetics of Organisms

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">REF and WEF Fly Genetics
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To prepare for the experiment, be sure to obtain cultures of <em>Drosophila melanogaster</em> at least two weeks ahead of the planned experiment day. NOTE: Because adult females store sperm after mating, you will need this time to generate virgin females by breeding the flies.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">You should get two stock cultures: wildtype, that is homozygous dominant red eyed flies, and white chromosome one mutant, which are homozygous recessive white eyed flies.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Purchase or create <em>Drosophila </em>habitats consisting of a clean vial, 3 cm of prepared food media, and a stopper to close the open end of the vial.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">When not being moved or counted, keep the flies in an incubator or room kept at 23 - 25 &#176;C, where the lifecycle will take around 12 days. NOTE: From the egg, <em>Drosophila </em>progress through four main stages of development: embryo, larva, pupa, and adult. The complete lifecycle takes about 10 days at 25 &#176;C, but it can be affected by temperature. For example, at 18 &#176;C, the lifecycle is about 19 days and at 29 &#176;C, the lifecycle is only seven days.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">As an overview, to set up for the student experiment, you will generate vials for each student group containing white eyed virgin female flies only, white eyed males only, red eyed virgin females only, and red eyed males only. These will be referred to as the experimental vials.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">When your vials from the supplier arrive, referred to as the stock vials, these will contain a mix of male and female flies, as well as larvae, pupae, and eggs.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Beginning with your stock vials, you will take around 3 - 5 males and the same number of females, keeping white eyed and red eyed flies separate at all times, and place these together into a new nursery vial containing food. NOTE: You can sex the flies using a magnifying glass. Look at the posterior of the fly. Males are slightly smaller and have darker solid pigment on the end of their abdomen. Females are larger and have stripes rather than a solid spot.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">You will leave the flies in these nursery vials for around 3 - 5 days to mate and lay eggs.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">After this, you will move them back to their stock vials.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Next, you will observe as the eggs and larvae in the nursery vials mature, checking the vials every 6 - 8 hours. As it takes females around 8 - 10 hours to become sexually mature, this should ensure that any females found in the nursery vials are virgin.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">As the new adult flies appear, you should transfer them from the nursery to the appropriate experimental tube. For example, if it is a male, transfer it to the experimental male tube for the appropriate eye color. If it is a female, it should be placed in an experimental vial labeled with eye color and virgin female.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Keep adding flies to the appropriate vials until each experimental vial has at least five flies. NOTE: You will need to make enough experimental vials so that each student group has one of each eye color type and sex, with a few class spares. You should create enough nursery vials to account for this. A good rule of thumb is that it generally takes about two weeks for 25 healthy adults to produce about 50 new adults.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">To begin the process, first label empty habitats to make the nursery vials to raise larvae and pupae for each strain of flies: red eyed and white eyed.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">To move the adult flies into the nursery vial to lay eggs, use an anesthesia wand according to the manufacturer&#39;s instructions, placing it into the stock vial of mature flies. Wait until the animals become unconscious. Now they can be gently tapped onto a piece of white paper and sorted into piles of the same sex using a brush.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Transfer a few male and female flies to the appropriate vial labeled with their eye color phenotype and sex.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Place the nursery vials to incubate at 23 to 25 &#176;C and the flies will lay eggs.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Remove the adults after 3 - 4 days using anesthesia and put them back into the stock vial.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Remove any adult flies that have eclosed in the 6 - 8 hour period using an anesthesia wand.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">Then, tip out the adults onto paper and sort them into groups based on their sex before placing each fly into an appropriate experimental vial marked male or virgin female and red or white for the phenotype. NOTE: Each experimental vial should contain five flies. Once this number is reached, then a new vial should be started. If you miss the 6 - 8 hour window, females may not be virgins, so these should be discarded into a morgue tube containing 70% ethanol or returned to the stock vial. Males do not need to be virgins, but do need to be kept in male only containers.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Each lab group will need one tube of five virgin red eyed females, one of five virgin white eyed females, one tube of red eyed males, and one of five white eyed males. In addition, they will need a morgue vial containing ethanol, two anesthesia wands, fly anesthetic, a paintbrush, a magnifying glass, some plain paper, and two empty fly vials for crosses.
</div></li></ul></li></ol>

Genetics of Organisms: REF and WEF Fly Genetics - Prep

生物の遺伝学

REF and WEF Fly Genetics
ExpandTo prepare for the experiment, be sure to obtain cultures of Drosophila melanogaster at least two weeks ahead of the ...

遺伝学

Artificial Selection

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Observing Artificial Selection in Plants 
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To begin the experiment, collect five two-week old grown plants from the generation one population that appear healthy. Note: Plants should appear green, not wilted, and not have damaged leaves. Experimental Hypothesis: The experimental hypothesis for this lab might be that the number of lead trichomes varies naturally, but the average number will increase over generations if only plants with the highest number of trichomes are interbred or decrease if those with the least are interbred. Null Hypothesis: The null hypothesis might be that the average number of trichomes will not change over subsequent generations after artificial selection.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Label each plant with a letter from A to E and with both partners&#8217; names.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Record any natural differences you see between your plant samples. Note: All of the plants are the same age, so any observed variation is due to expressed phenotype, not development.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Use a hand lens to count the number of trichomes found on the petiole of the lowest leaf, not including the round, first-grown cotyledons for each plant. Note: It can be helpful to shine a light onto the plant and to hold it against a dark background, such as a lab bench, during the trichome analysis. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Both partners will conduct counts on each plant independently and compare answers. If the counts are different, enlist a third counter or take the average of the two results.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">After this, determine the median number of trichomes for the entire class.  <a target="__blank" style="display:block;padding:20px;" href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/2/Lab_2_Table_A.xlsx">Click Here to download Table A</a>
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Determine the top and bottom 10% of the plants from the class trichome count. These groups will make up the two artificially selected lines: high hairiness and low hairiness, respectively.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">If more than 10% of the plants have no trichomes, select 10% of those plants randomly for the low hairiness plant line.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Separate the two groups of selected plants and label them clearly.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Move the plants to a well-lit area and keep them well watered until they develop flowers. Note: Flowers typically develop around 14 days.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When the flowers are fully developed, use a pollination wand or paintbrush to rub the stigma and anther of one plant&#8217;s flowers for a few seconds.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Using the same wand or brush, rub the inside of each flower of every other plant in the same selection line.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">Using a different wand or brush, repeat steps 11 through 12 on the other line. Note: Take care not to cross the lines. Spread the pollen only among the appropriately selected plants.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Return the generation one plants to the growing areas. When the plants reach approximately 1 month old, they should produce mature seed pods.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Allow the plants to dry out once the seed pods turn yellow.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Break the seed pods open and collect the seeds.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Obtain new pots for the generation two seeds.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Fill the pots with moist potting soil about halfway and add a fertilizer pellet to each pot.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">Fill the pots with more soil to fill just below the lip.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Make a shallow depression in the soil of each pot with a probe.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Touch a clean toothpick to a gluestick and use the toothpick to transplant the seeds into the soil one by one.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Cover the seeds with a thin layer of soil.
</div></li><li data-sub-note-item="1-23"><div class="lab-step">Label the pots with their hairiness line and place them in the designated growing area.
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Use a plastic dropper to water the plants as needed to ensure they do not dry out.
</div></li><li data-sub-note-item="1-25"><div class="lab-step">When the plants are two weeks old, collect five plants from each line and label them A to E.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">Then, count the trichomes on these plants as previously described (steps 4- 5).
<a target="__blank" style="display:block;padding:20px;" href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/2/Lab_2_Table_B.xlsx">Click Here to download Table B</a>
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Data Analysis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Create a frequency graph based on the generation one class data with the trichome count on the x axis and the number of plants on the y axis. Label the mean. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Then, create frequency graphs for both of the selected hairiness lines.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare the frequency graphs for generation one and both hairiness lines.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Take note of phenotypic shifts observed in the selected hairiness lines.
</div></li></ul></li></ol>

Artificial Selection: Visualization in Plants and Data Analysis - Procedure

人工選択

Observing Artificial Selection in Plants 
ExpandTo begin the experiment, collect five two-week old grown plants from the generation one population that ...

進化論

Physiology of the Circulatory System

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Measuring Circulatory System Function in Humans
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Before starting the experiment go to the front of the room and collect an alcohol swab, a sphygmomanometer, and a stethoscope.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Clean the earpieces with the alcohol swab and then insert them into your ears.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">To check if the stethoscope is in the on position, gently tap the flat metal disc called the diaphragm.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">If you hear a sound it&#39;s on. If not, turn the metal disc and tap again and keep turning and tapping the disc until you hear a sound. NOTE: For this experiment you will work in pairs. One person will measure their partner&#39;s blood pressure, while the person being measured will count their heartbeats over the course of one minute.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Fill out table one with the name of the person being monitored. HYPOTHESES: The experimental hypothesis is that systolic blood pressure will be higher when the person is sitting when compared to lying down because more pressure is required for blood to be moved around the body. The null hypothesis is that there will be no difference in systolic blood pressure whether a person is sitting or lying down.<a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/9/Table_1_Physiology_of_Circulatory_System.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-6"><div class="lab-step">The person being monitored should begin by lying down. Next, they will need to locate their pulse by placing two fingers next to their windpipe. If a throbbing sensation is felt, this is the pulse.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Now, ready a time keeping device to count out 1 minute as the person taking their pulse will be having their blood pressure taken at the same time.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">At this point, the person measuring blood pressure should place the cuff of the sphygmomanometer around the other arm of the subject and the stethoscope earpieces into their own ears.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Start the timer.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">The person being monitored should begin counting the number of heartbeats felt over one full minute. While the subject is taking their pulse, the person taking blood pressure should place the diaphragm of the stethoscope under the cuff on the inside of their partner&#39;s elbow.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Then, pump the cuff to 200 mm of mercury.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Gently and slowly twist the metal knob on the sphygmomanometer to release air from the cuff.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">As pressure is released the first Korotkoff sound should be heard. The corresponding value on the sphygmomanometer is the systolic blood pressure. Consistent sounds should be heard until they die out with the last sound signifying the diastolic blood pressure.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Record the systolic pressure, the diastolic pressure, and the heart rate in Table 1.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Now, repeat the blood pressure and pulse measurements with each partner keeping the same role but this time the subject should be sitting upright.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Record these data in the appropriate places in Table 1.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Finally, the partners should switch spots. So now, the person measuring blood pressure should be taking their pulse and acting as the subject.  NOTE: Be sure to wipe the earpieces of the stethoscope between users and don&#39;t forget to record your measurements in Table 1.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">After finishing the experiment, discard all alcohol swabs into the trash. Then, bring the sphygmomanometer and stethoscope back to the front of the room.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Measuring Respiratory Rate in Fish
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To prepare for this second experiment, collect two clear containers.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Begin by filling half of one container with aquarium water.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Then, use a fish net to gently catch a goldfish and place it into the cup. Pinch the net around the fish or else it may jump out of the net.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Familiarize yourself with the operculum of the fish. The operculum covers the gills and it is located behind and below the eye. When the fish respires the operculum moves in and out and this is one gill beat. HYPOTHESES: In this experiment you will measure the gill beats of the fish in different water temperatures. The hypothesis is that there will be a significant correlation between the temperature and respiration rate in goldfish. The null hypothesis is that there will be no correlation between temperature and respiration rate.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Take the other empty container with a screw cap, the cup with your fish, and the net to the water tanks.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Then, fill the empty container with the water from the lowest temperature water bath. This will act as your first respiration rate chamber.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Next, hold the fish net over a wastewater container and dump out the water from the cup holding the fish so that the fish falls into the net. Pinch the net around the fish without touching the fish itself.
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Bring the net over the top of the container with the bath water and let go of the net to release the fish into the vial.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Once the fish is in the container, submerge it back into the water bath and then screw the cap on to prevent outside oxygen from entering the vial.
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Next, remove the container from the controlled temperature water bath and place it on your workbench surface to avoid warming the water with body heat.
</div></li><li data-sub-note-item="2-11"><div class="lab-step">One partner should immediately begin counting the gill beats as soon as the second partner starts the stopwatch.
</div></li><li data-sub-note-item="2-12"><div class="lab-step">Continue counting the beats for 20 seconds. Record the number of beats in column A of Table 2. <a href="https://www-jove-com.remotexs.ntu.edu.sg/CDNSource/lm/labs/9/Table_2_Physiology_of_Circulatory_System.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-13"><div class="lab-step">Repeat the measurement one more time and record the number in column B.
</div></li><li data-sub-note-item="2-14"><div class="lab-step">Next, hold the fish net over a wastewater container and dump out the water from the fish vial so that the fish falls into the net.  IMPORTANT: Move from lowest to highest temperature, so the fish is not stressed between trials.
</div></li><li data-sub-note-item="2-15"><div class="lab-step">Repeat the experiment for the remaining four temperature conditions (steps 8 &#8211; 13).
</div></li><li data-sub-note-item="2-16"><div class="lab-step">Record all the values for different temperatures in Table 2.
</div></li><li data-sub-note-item="2-17"><div class="lab-step">Once you are done, slowly mix water from the last respiration chamber with the fish tank water and then return the fish to the home tank. NOTE: This should be done over the course of approximately 10 minutes.
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">It&#39;s time to analyze the data that you just collected. Look at the blood pressure and heart rate measurements for the different trials. If they were different, make a hypothesis to explain your observations. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">For the gill beat experiment, average the numbers in columns A and B and calculate the fish respiration rate as gill beats per minute.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Next, plot the graph of temperature versus gill beats per minute.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Record any correlations you see between the variables. If a correlation is observed, determine if it is positive or negative and provide an explanation for this result.  NOTE: Consider the fact that fishes are ectotherms and the impact of temperature on dissolved oxygen.
</div></li></ul></li></ol>