Wir danken für die Fotos von Austern und Messen ihre klaffen Breite in ImageJ Melinda Forseth. Wir danken Denise Breitburg für den Zugriff auf die Aquarien mit Diel Radfahren Hypoxie und zyklischen pH-Bedingungen. Wir danken dem Smithsonian Environmental Research Center, Edgewater, Maryland, Raum für Experimente. Die Hypoxie-Experimente wurden von einem National Oceanic and Atmospheric Administration - Zentrum für gesponserte Coastal Ocean Research Grant Nein finanziert. NA10NOS4780138 und dem Smithsonian Hunterdon Fonds, Denise Breitburg. Das Ventil klaffen Messungen während der Hypoxie, die Experimente durch eine Fakultät für Verbesserung von Washington College, Elka T. Porter finanziert wurden.

Wir haben nicht alles offenlegen.

Typische Studien Fokus auf kontinuierliche, erweitert Zeiträume der sauerstoffarmen Bedingungen und die Antwort, die oft als das Überleben der Tiere gemessen. Zur Zeit ist unser Verständnis von Verhaltensreaktionen von Tieren zur Hypoxie Diel Radfahren jedoch minimal63. Daher sollten weitere Studien auf das Verhalten der Organismen als Reaktion auf Hypoxie Diel-Radfahren konzentrieren, die tritt regelmäßig im Laufe des Sommers in vielen Flussmündungen7,<sup...

Hypoxie, d.h. aufgelöst Sauerstoffkonzentrationen [] ausreichend niedrige um sich negativ auf biologische und ökologische Prozesse aber oft funktionell definiert als [tun] < 2 mg / L1und Sauerstoffmangel (funktional definiert als [tun] 0,0-0,2 mg/L) treten immer häufiger und stark in der Welt Küstengewässer, Flussmündungen und die Tiefen des Ozeans2,3 auf und sind oft verschärft durch die zunehmende Eutrophierung4,5. Mit areal in zunehmendem Maße von Hypoxie und Anoxie Makrofauna negativ beeinflusst und verlieren Lebensraum Umfang und Lebensraumqualität. Der Klimawandel wird voraussichtlich Hypoxie und Anoxie6verschlechtern.
In vielen geschichtete, Nährstoff angereicherte Flussmündungen wie Chesapeake Bay, USA saisonal anhaltende Hypoxie kann sich durchsetzen und Jahr für Jahr2auftreten kann. Darüber hinaus Diel-Radfahren von Hypoxie ist häufig in Flussmündungen wie der Chesapeake Bay und an anderen Orten und tritt spät während der Nacht oder den frühen Morgenstunden in der Sommer-7,-8.
Die meisten Studien konzentrierten sich auf die Wirkung der Dauerbelastung von Organismen zu niedrigen [tun] und auf ihre Toleranz gegenüber Hypoxie und Anoxie9,10,11,12,13,14 . Darüber hinaus haben Studien der großen Verschiebung der Artenzusammensetzung Distributionen, Häufigkeiten und Arten als Reaktion auf Erweiterte niedrig [tun]4,15angeschaut. Oft Arten, die sehr empfindlich auf niedrige in Massen sterben [],16 verlagert die übrigen Arten, eine jüngere, kleinere, kurzlebige Fauna wie zum Beispiel auf der Louisiana-Texas Regal Ökosystem4gefunden.
Verhaltensänderungen in der Regel vorausgehen Gemeinschaft Zusammenbruch17 und Studien haben berichtet, auf Verhaltensreaktionen von Organismen auf Erweiterte niedrig [tun]4,16,17,18,19 ,20,21,22,23,24,25. Diese Studien jedoch konzentrieren nicht auf den Antworten von Organismen Diel-cycling Belichtungen von Hypoxie und dem schwankenden Charakter [tun] Verfügbarkeit in Flussmündungen.
Diel-Radfahren Hypoxie in seichten Flussmündungen erhielt Sensibilisierung als Studien zu [tun] mehr überwachen häufig im Laufe der Tage mit Sonden in Flussmündungen16,26. Wasser kann für Stunden am Ende der Nacht oder am frühen Morgenstunden im Sommer hypoxischen bleiben wenn es keine Photosynthese Sauerstoff erzeugenden während der Nacht aber hohe Sauerstoff verbrauchenden gibt aerobe Atmung7,16. Ferner wurde festgestellt, dass die Gezeiten die Diel beeinflusst Radfahren niedrig-Bedingungen mit den extremen Minima beobachtet, wenn Ebbe fiel mit dem Ende der Nacht27. Erst nach mehreren Stunden der Hypoxie [tut] normoxiezustand7,16,28 im täglichen Zyklus zurückkommen.
Bestimmen die Verhaltensreaktion C. Virginica Diel Radfahren Hypoxie und pH-Wert wir überwacht das Öffnen und Schließen der Ventile von Austern ans Labor induzierte Diel Radfahren [tun] und zyklischen pH. Gape Antworten von Muscheln wurden zur ungünstigen Umweltbedingungen erkennen. Ventil-Schließungen von Muscheln als Reaktion auf Verunreinigungen29,30,31, giftige Algen32,33,34, thermische Verunreinigung35,36 , 37, Essen Quantität verringern38,39,40, Fütterung Regime39,41, auftauchen37,42, Photoperiode43 , 44, pH45,46, und kombinierte pH und gelösten Sauerstoff47 wurden gemessen. Gape Techniken haben, direkte Beobachtungen48,49,13, kontinuierliche Messungen mit Reed-Schalter und Magnete (Dreissena Monitor)50oder faseroptischen Sensoren beispielsweise enthalten. 51 , die klares Wasser benötigen. Darüber hinaus wurden Magnet und Magnetfeld Stärke-Hall-Sensoren zur Muschel Gape Winkel52,53,54,55, und eine hochfrequente elektromagnetische Induktionssystem studieren dass die unterschiedlichen Distanz zwischen zwei elektrischen Spulen, die auf den Ventilen geklebt werden bislang56,57,58,59verwendet. Eine Hochspannungsquelle ist erforderlich für die elektromagnetische Induktionssystem und macht hat an beiden Seiten der Schale52geliefert werden. Dieses System ist auch als "MOSSELMONITOR" (http://mosselmonitor.nl/) im Handel erhältlich.
Auf einem engen Forschungsbudget wir einen kostengünstige DMS-Monitor (SGM) kontinuierlich zu Auster Gape Messen über Labor-induzierte Diel gebaut [tun] Radfahren und pH unter schlechten Sichtverhältnissen. Unser System ist auch viel einfacher als konkurrierende Systeme, so dass viele Tiere während eines Experiments instrumentiert werden. Wir wollten herausfinden, die Verhaltensreaktionen von C. Virginica , Diel Radfahren schwere ([] = 0,6 mg/L) Hypoxie mit Kontrolle pH (pH = 7,8) und Radsport pH (pH = 7,8-7.0) bzw. und Gape Antworten zu Mild ([] = 1,7 mg/L) Hypoxie. Darüber hinaus wollten wir um festzustellen, ob Austern in der Lage sind, auf Veränderungen schnell reagieren, [] über die Diel Zyklus und wie sie reagieren, wenn normoxiezustand nach einem hypoxischen Event kehrt zurück. Vielleicht sind Austern optimal angepasst an die stark schwankenden Umgebung, die in vielen Flussmündungen16,27 gefunden wird, wo sie leben. Während komplexer Ventil Gape Monitore zur Verfügung stehen, bietet der SGM eine preiswerte Technik, die Dauermessungen Ventil klaffen in den Gewässern auch bei schlechten Sichtverhältnissen ermöglicht.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57404/57404fig1.jpg"> Abbildung 1. Wheatstone-Brücke für den Ventil Gape Apparat. <a href="/files/ftp_upload/57404/57404fig1large.jpg" target="_blank">Bitte klicken Sie hier für eine größere Version dieser Figur.</a>
Die DMS-Sensoren zur Überwachung von zweischaligen Gape eingesetzt sind resistive Filme in einem Mäander-Muster auf einem Polyimid sichern. Geringe Mengen an Stamm modulieren den Widerstand des Sensors. Die Muscheln beugt DMS, wenn es klafft verursacht eine Änderung in der Widerstand des Sensors. Wir Beschäftigten eine Abgleich, ausgewogene, Wheatstone-Brücke für jeden zweischaligen Kanal, wie in Abbildung 1 dargestellt, um den Wandel im Widerstand des Sensors messen. Die Wheatstone-Brücke ist durch das Potentiometer ermöglicht eine relativ hohe Verstärkung durch den Datenlogger eingesetzt werden wwww. Eine Wheatstone-Brücke ist eine Standardmethode für die präzise Messung einen unbekannten Widerstand Verhältnis zu einem bekannten Widerstand standard und ein Voltmeter. Die Geschichte dieser uralten Technik ist in Ekelof (2001)60diskutiert. Wir haben 12 Kanäle, jeweils mit eigenem Wheatstone-Brücke und Abgleich Potentiometer in DMS-Monitor (SGM) Einheit integriert.

<table border="0" cellpadding="0" cellspacing="0" style="width:805px;" width="805">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">Campbell CR 10x data logger</td>
			<td style="width:268px;">Campbell Scientific, Logan, Utah</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Or other data logger. At Campbell the CR 10X has been replaced with the CR 1000</td>
		</tr>
		<tr height="51">
			<td height="51" style="height:51px;width:216px;">Campbell CR 10x multiplexer</td>
			<td>Campbell Scientific, Logan, Utah</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Data logger needs to have space for 12 channels</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:216px;">Dsub connector male crimp pins</td>
			<td style="width:268px;">TE Connectivity</td>
			<td>205089-1</td>
			<td style="width:183px;">pins for gape sensor leads</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PCA tape</td>
			<td>Micro Measurements Corp, NC</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">To seal the strain gauge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Duro Quick Gel</td>
			<td>Ace Hardware</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Superglue</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">SG13/1000-LY43 or LY41</td>
			<td>Omega Engineering Inc., Stanford, CT</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Strain gauges</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">32 AWG (7/40) teflon Alpha wires</td>
			<td style="width:268px;">AlphaWire, Elizabeth, NJ</td>
			<td style="width:139px;">2840/7</td>
			<td style="width:183px;">Sensor cables, different colors are available</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">1/16&#34; heat shrink tubing</td>
			<td style="width:268px;">Qualtek</td>
			<td>B01A3QKKO6</td>
			<td style="width:183px;">To seal the leads of the sensor cable</td>
		</tr>
		<tr height="210">
			<td height="210" style="height:210px;width:216px;">Weller WES51 Analog Soldering Station</td>
			<td style="width:268px;">Amazon</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Lots of soldering, need a good soldering iron. https://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU/ref=sr_1_23?s=hi&#38;ie=UTF8&#38;qid=1505654295 
			&#38;sr=1-23&#38;keywords=soldering+iron</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Rosin Soldering Flux Paste</td>
			<td style="width:268px;">Amazon</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Needed for soldering</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">60-40 Tin Lead Rosin Core Solder Wire</td>
			<td style="width:268px;">Amazon</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Needed for soldering</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Aquarium sealant</td>
			<td style="width:268px;">Home Depot</td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Attach sensors to bivalve</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">PC Laptop</td>
			<td style="width:268px;"></td>
			<td style="width:139px;"></td>
			<td style="width:183px;">Any old PC to run Campbell gape program</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">heat gun</td>
			<td>Amazon</td>
			<td></td>
			<td style="width:183px;">shrink shrink tubing</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Drill</td>
			<td>Hardware store, Amazon</td>
			<td></td>
			<td style="width:183px;">for twisting wires to make sensor cables</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">AC to DC power module</td>
			<td>Acopian</td>
			<td>DB15-30</td>
			<td style="width:183px;">Wheatstone bridge power supply</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Poteniometer</td>
			<td>Clarostat</td>
			<td>733A</td>
			<td style="width:183px;">Wheatsone bridge nulling</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">isolating BNC connector</td>
			<td>Sterren Electronics</td>
			<td>&#34;200-148</td>
			<td style="width:183px;">Wheatstone bridge output for multimeter</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Fused AC receptical panel module</td>
			<td>Adam technologies</td>
			<td>IEC-GS-1-200</td>
			<td style="width:183px;">Wheatstone bridge power supply connector</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">976 ohm 1% resistor</td>
			<td>Vishay Dale</td>
			<td>CMF50976R00FHEB</td>
			<td style="width:183px;">Wheatstone bridge resistor</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">1 kohm 1% resistor</td>
			<td>Vishay Dale</td>
			<td>CMF501K0000FHEB</td>
			<td style="width:183px;">Wheatstone bridge resistor</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Potentiometer scale dial</td>
			<td>Kilo International</td>
			<td align="right">462</td>
			<td style="width:183px;">10 turn dial for nulling potentiometer</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">DB25 male panel connector</td>
			<td>TE connectivity</td>
			<td>1757819-8</td>
			<td style="width:183px;">Data logger connector on Wheatstone bridge</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">DB25 female panel connector</td>
			<td>TE connectivity</td>
			<td>1757819-8</td>
			<td style="width:183px;">Sensor connector to Wheatstone bridge</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">perforated circuit board</td>
			<td>Vector electronics</td>
			<td>64P44WE</td>
			<td style="width:183px;">circuit board for mounting of bridge components</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">enclosure</td>
			<td>Hammond Manufacturing</td>
			<td>1444-29</td>
			<td style="width:183px;">Enclosure for sensor readout electronics</td>
		</tr>
	</tbody>
</table>

a strain gauge monitor (sgm) for continuous valve gape measurements in bivalve molluscs in response to laboratory induced diel-cycling hypoxia and ph

Ein preiswerte, Labor-basierte DMS Ventil Gape Monitor (SGM) wurde entwickelt, um das Ventil Gape Verhalten von Muscheln als Reaktion auf Hypoxie Diel-Radfahren zu überwachen. Eine Wheatstone-Brücke wurde mit Dehnungsmessstreifen verbunden, die die Schalen der Austern (Crassostrea Virginica) zugeordnet wurden. Die aufgezeichneten Signale erlaubt für das Öffnen und Schließen der Muscheln, kontinuierlich über aufgezeichnet werden jeweils zweitägigen Perioden der experimentell induzierten Diel Radfahren Hypoxie und Diel Radfahren Veränderung des pH-Wertes. Hier wir beschreiben ein Protokoll für eine kostengünstige DMS-Monitor zu entwickeln und in einem Laborexperiment Beispiel beschreiben, wie wir es verwendet, um das Ventil Gape Verhalten Messen Eastern Austern (C. Virginica), als Reaktion auf Hypoxie Diel-Radfahren und zyklische Veränderungen des pH-Wertes. Ventil Gape auf Austern ausgesetzt zyklischen schweren hypoxischen (0,6 mg/L) gemessen wurde aufgelöst sauerstoffbedingungen mit und ohne zyklische Veränderungen im pH-Wert, zyklische milde Hypoxie (1,7 mg/L) und Inklusieve (7,3 mg/L) Bedingungen. Wir zeigen, dass wenn Austern wiederholte Diel Zyklen begegnen, sie schnell ihre Schalen als Reaktion auf schwere Hypoxie schließen und mit einer zeitlichen Verzögerung zur Milde Hypoxie schließen. Wenn normoxiezustand wiederhergestellt wird, öffnen sie schnell wieder. Austern reagierte nicht auf zyklische pH-Bedingungen Diel Radfahren schwere Hypoxie überlagert. Bei reduzierten sauerstoffbedingungen mehr als ein Drittel der Austern gleichzeitig geschlossen. Wir zeigen, dass Austern auf Diel Radfahren Hypoxie reagieren, die berücksichtigt werden müssen bei der Beurteilung des Verhaltens der Muscheln zu Sauerstoff aufgelöst. Das Ventil SGM kann verwendet werden, um Antworten von Muscheln auf Änderungen an gelöstem Sauerstoff oder Verunreinigungen zu beurteilen. Dichtungstechniken für bessere Abdichtung brauchen Ventil Gape Dehnungsmessstreifen aus Meerwasser weitere Verbesserungen erhöhen die Lebensdauer der Sensoren.

Austern, die ununterbrochene Inklusieve Mündungs Wasser (keine Hypoxie während der niedrigen Plateauphase des täglichen Zyklus) ausgesetzt waren die meiste Zeit offen und selten nur kurz geschlossen (Abbildung 5). Wenn sie abwechslungsreiche von Auster, Austern geschlossen. Dieses Muster ist auch in Loosanoff und Nomejko 194644 und Higgins 198039festgestellt worden. Austern reagierte auch nicht auf die Differ...

Watch this Scientific Journal Video about A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH at JoVE.co

A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

Ein DMS-Monitor (SGM) für Ventil klaffen Dauermessungen in Muscheln Muscheln als Reaktion auf Hypoxie Labor induzierte Diel-Radfahren und pH-Wert

Verständnis der Verhaltensreaktionen von zweischaligen Aussetzung-Zubringer zu Umgebungsvariablen wie gelöster Sauerstoff, kann einige Ökosystemprozesse erklären. Wir haben einen kostengünstige, Labor-basierte, DMS-Monitor (SGM) Ventil Gape Antworten von Austern, Crassostrea Virginica, Messen, Diel Radfahren Hypoxie und zyklischen pH entwickelt.

An inexpensive, laboratory-based, strain gauge valve gape monitor (SGM) was developed to monitor the valve gape behavior of bivalve molluscs in response ...

a-strain-gauge-monitor-sgm-for-continuous-valve-gape-measurements

Universidad San Sebastian

Research

JoVE Journal

Environment

A Strain Gauge Monitor (SGM) for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

8.9K Aufrufe.  University of Baltimore. Verständnis der Verhaltensreaktionen von zweischaligen Aussetzung-Zubringer zu Umgebungsvariablen wie gelöster Sauerstoff, kann einige Ökosystemprozesse erklären. Wir haben einen kostengünstige, Labor-basierte, DMS-Monitor (SGM) Ventil Gape Antworten von Austern, Crassostrea Virginica, Messen, Diel Radfahren Hypoxie und zyklischen pH entwickelt.

Serie: A Strain Gauge Monitor SGM for Continuous Valve Gape Measurements in Bivalve Molluscs in Response to Laboratory Induced Diel-cycling Hypoxia and pH

Optimize Flue Gas Settings to Promote Microalgae Growth in Photobioreactors via Computer Simulations

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions1. Microalgae not only capture solar energy more efficiently than plants3, but also synthesize advanced biofuels2-4. Generally, atmospheric CO2 is not a sufficient source for supporting maximal algal growth5. On the other hand, the high concentrations of CO2 in industrial exhaust gases have adverse effects on algal physiology. Consequently, both cultivation conditions (such as nutrients and light) and the control of the flue gas flow into the photo-bioreactors are important to develop an efficient &ldquo;flue gas to algae&rdquo; system. Researchers have proposed different photobioreactor configurations4,6 and cultivation strategies7,8 with flue gas. Here, we present a protocol that demonstrates how to use models to predict the microalgal growth in response to flue gas settings. We perform both experimental illustration and model simulations to determine the favorable conditions for algal growth with flue gas. We develop a Monod-based model coupled with mass transfer and light intensity equations to simulate the microalgal growth in a homogenous photo-bioreactor. The model simulation compares algal growth and flue gas consumptions under different flue-gas settings. The model illustrates: 1) how algal growth is influenced by different volumetric mass transfer coefficients of CO2; 2) how we can find optimal CO2 concentration for algal growth via the dynamic optimization approach (DOA); 3) how we can design a rectangular on-off flue gas pulse to promote algal biomass growth and to reduce the usage of flue gas. On the experimental side, we present a protocol for growing Chlorella under the flue gas (generated by natural gas combustion). The experimental results qualitatively validate the model predictions that the high frequency flue gas pulses can significantly improve algal cultivation.

Flue gas from power plants is a cheap CO2 source for algal growth. We have built prototype &#34;flue gas to algal cultivation&#34; systems and described how to scale up the algal cultivation process. We have demonstrated the use of a mass-transfer bio-reaction model to simulate and to design the optimal operation of flue gas for the growth of Chlorella sp. in algal photo-bioreactors.

Optimieren Rauchgas Einstellungen, um Mikroalgen in Photobioreaktoren Wachstum über Computer-Simulationen fördern

Flue gas from power plants can promote algal cultivation and reduce greenhouse gas emissions1. Microalgae not only capture solar energy more efficiently ...

Forschung

Umwelt

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes and soil organic matter formation to small-scale stable-isotope biomarker probing. Coupling multiple stable isotopes such as 13C with 15N, 18O or&#160;2H has the potential to reveal even more information about complex stoichiometric relationships during biogeochemical transformations. Isotope labeled plant material has been used in various studies of litter decomposition and soil organic matter formation1-4. From these and other studies, however, it has become apparent that structural components of plant material behave differently than metabolic components (i.e. leachable low molecular weight compounds) in terms of microbial utilization and long-term carbon storage5-7. The ability to study structural and metabolic components separately provides a powerful new tool for advancing the forefront of ecosystem biogeochemical studies. Here we describe a method for producing 13C and 15N labeled plant material that is either uniformly labeled throughout the plant or differentially labeled in structural and metabolic plant components.
Here, we present the construction and operation of a continuous 13C and 15N labeling chamber that can be modified to meet various research needs. Uniformly labeled plant material is produced by continuous labeling from seedling to harvest, while differential labeling is achieved by removing the growing plants from the chamber weeks prior to harvest. Representative results from growing Andropogon gerardii Kaw demonstrate the system&#39;s ability to efficiently label plant material at the targeted levels. Through this method we have produced plant material with a 4.4 atom%13C and 6.7 atom%15N uniform plant label, or material that is differentially labeled by up to 1.29 atom%13C and 0.56 atom%15N in its metabolic and structural components (hot water extractable and hot water residual components, respectively). Challenges lie in maintaining proper temperature, humidity, CO2 concentration,&#160;and light levels in an airtight 13C-CO2 atmosphere for successful plant production. This chamber description represents a useful research tool to effectively produce uniformly or differentially multi-isotope labeled plant material for use in experiments on ecosystem biogeochemical cycling.

Design and Operation of a Continuous 13C and 15N Labeling Chamber for Uniform or Differential, Metabolic and Structural, Plant Isotope Labeling

This method explains how to build and operate a continuous 13C and 15N isotope labeling chamber for uniform or differential plant tissue labeling. Representative results from metabolic and structural labeling of Andropogon gerardii are discussed.

Aufbau und Betrieb einer Dauer<sup&gt; 13</sup&gt; C und<sup&gt; 15</sup&gt; N Labeling Kammer für Uniform oder Differential, Stoffwechsel-und Struktur, Pflanze Isotope Labeling

Tracing rare stable isotopes from plant material through the ecosystem provides the most sensitive information about ecosystem processes; from CO2 fluxes ...

Methods of Soil Resampling to Monitor Changes in the Chemical Concentrations of Forest Soils

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental changes. Repeated sampling to monitor these changes in forest soils is a relatively new practice that is not well documented in the literature and has only recently been broadly embraced by the scientific community. The objective of this protocol is therefore to synthesize the latest information on methods of soil resampling in a format that can be used to design and implement a soil monitoring program. Successful monitoring of forest soils requires that a study unit be defined within an area of forested land that can be characterized with replicate sampling locations. A resampling interval of 5 years is recommended, but if monitoring is done to evaluate a specific environmental driver, the rate of change expected in that driver should be taken into consideration. Here, we show that the sampling of the profile can be done by horizon where boundaries can be clearly identified and horizons are sufficiently thick to remove soil without contamination from horizons above or below. Otherwise, sampling can be done by depth interval. Archiving of sample for future reanalysis is a key step in avoiding analytical bias and providing the opportunity for additional analyses as new questions arise.

Repeated soil sampling has recently been shown to be an effective way to monitor forest soil change over years and decades. To support its use, a protocol is presented that synthesizes the latest information on soil resampling methods to aid in the design and implementation of successful soil monitoring programs.

Methoden der Boden Resampling zur Überwachung von Veränderungen in der chemischen Konzentrationen von Waldböden

Recent soils research has shown that important chemical soil characteristics can change in less than a decade, often the result of broad environmental ...

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. However, they are vulnerable parts of the landscapes that are often poorly understood and understudied. Land use and management practices, as well as climate change are thought to be a contribution to the global amphibian decline. However, more research is needed to understand the extent of these impacts. Here, we present methodology for characterizing a vernal pond's morphology and detail a monitoring station that can be used to collect water quantity and quality data over the duration of a vernal pond's hydroperiod. We provide methodology for how to conduct field surveys to characterize the morphology and develop stage-storage curves for a vernal pond. Additionally, we provide methodology for monitoring the water level, temperature, pH, oxidation-reduction potential, dissolved oxygen, and electrical conductivity of water in a vernal pond, as well as monitoring rainfall data. This information can be used to better quantify the ecosystem services that vernal ponds provide and the impacts of anthropogenic activities on their ability to provide these services.

Understanding the ecosystem services and processes provided by vernal ponds and the impacts of anthropogenic activities on their ability to provide these services requires intensive hydrologic monitoring. This sampling protocol using in-situ monitoring equipment was developed to understand the impact of anthropogenic activities on water levels and quality.

Kontinuierliche hydrologischen und Qualitätsüberwachung von Vernal Teichen

Vernal ponds, also referred to as vernal pools, provide critical ecosystem services and habitat for a variety of threatened and endangered species. ...

Adherence of Bacteria to Plant Surfaces Measured in the Laboratory

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell counts. Plant materials used include roots, sprouts, leaves, and cut fruits. The methods described are inexpensive, easy, and suitable for small sample sizes. Binding is measured in the laboratory and a variety of incubation media and conditions can be used. The effect of inhibitors can be determined. Situations that promote and inhibit binding can also be assessed. In some cases it is possible to distinguish whether various conditions alter binding primarily due to their effects on the plant or on the bacteria.

An easy method for measuring and characterizing bacterial adhesion to plants, particularly roots and sprouts, is described in this article.

Einhaltung von Bakterien auf Flächen, die im Labor ermittelten Pflanzen

This manuscript describes a method to measure bacterial binding to axenic plant surfaces in the light microscope and through the use of viable cell ...

The Calibration and Use of Capacitance Sensors to Monitor Stem Water Content in Trees

Water transport and storage through the soil-plant-atmosphere continuum is critical to the terrestrial water cycle, and has become a major research focus area. Biomass capacitance plays an integral role in the avoidance of hydraulic impairment to transpiration. However, high temporal resolution measurements of dynamic changes in the hydraulic capacitance of large trees are rare. Here, we present procedures for the calibration and use of capacitance sensors, typically used to monitor soil water content, to measure the volumetric water content in trees in the field. Frequency domain reflectometry-style observations are sensitive to the density of the media being studied. Therefore, it is necessary to perform species-specific calibrations to convert from the sensor-reported values of dielectric permittivity to volumetric water content. Calibration is performed on a harvested branch or stem cut into segments that are dried or re-hydrated to produce a full range of water contents used to generate a best-fit regression with sensor observations. Sensors are inserted into calibration segments or installed in trees after pre-drilling holes to a tolerance fit using a fabricated template to ensure proper drill alignment. Special care is taken to ensure that sensor tines make good contact with the surrounding media, while allowing them to be inserted without excessive force. Volumetric water content dynamics observed via the presented methodology align with sap flow measurements recorded using thermal dissipation techniques and environmental forcing data. Biomass water content data can be used to observe the onset of water stress, drought response and recovery, and has the potential to be applied to the calibration and evaluation of new plant-level hydrodynamics models, as well as to the partitioning of remotely sensed moisture products into above- and belowground components.

The hydraulic capacitance of biomass is a key component of the vegetation water budget, which serves as a buffer against short and long-term drought stresses. Here, we present a protocol for the calibration and use of soil moisture capacitance sensors to monitor water content in the stems of large trees.

Die Kalibrierung und die Nutzung der Kapazität Sensoren Stem Wassergehalt in den Bäumen zu überwachen

Water transport and storage through the soil-plant-atmosphere continuum is critical to the terrestrial water cycle, and has become a major research focus ...

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current measures to combat such pathogens have proved too conservative and, thus, not sufficiently effective, and they can potentially pose environmental risks. Therefore, it is extremely necessary to identify host-resistance factors to assist in controlling plant diseases naturally through the identification of resistant germplasm, the isolation and characterization of resistance genes, and the molecular breeding of resistant cultivars. In this regard, there is need to establish an accurate, rapid, and large-scale inoculation method to breed and develop plant resistance genes. The rice blast fungal pathogen Magnaporthe grisea causes severe disease symptoms and yield losses. Recently, M. grisea has emerged as a model organism for studying the mechanisms of plant-fungal pathogen interactions. Hence, we report the development of a plant virulence test method that is specific for M. grisea. This method provides for both spray inoculation with a conidial suspension and wounding inoculation with mycelium cubes or droplets of conidial suspension. The key step of the wounding inoculation method for detached rice leaves is to make wounds on plant leaves, which avoids any interference caused by host penetration resistance. This spray/wounding protocol contributes to the rapid, accurate, and large-scale screening of the pathotypes of M. grisea isolates. This integrated and systematic plant infection method will serve as an excellent starting point for gaining a broad perspective of issues in plant pathology.

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

Here, we present a protocol to test plant virulence with the plant pathogen Magnaporthe grisea. This report will contribute to the large-scale screening of the pathotypes of fungi isolates and serve as an excellent starting point for understanding the resistant mechanisms of plants during molecular breeding.

Die Pflanze-Infektion-Test: Spray und Wunde-vermittelten Inokulation mit Pflanzen Pathogen Magnaporthe Grisea

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current ...

A Flexible Low Cost Hydroponic System for Assessing Plant Responses to Small Molecules in Sterile Conditions

A wide range of studies in plant biology are performed using hydroponic cultures. In this work, an in vitro hydroponic growth system designed for assessing plant responses to chemicals and other substances of interest is presented. This system is highly efficient in obtaining homogeneous and healthy seedlings of the C3 and C4 model species Arabidopsis thaliana and Setaria viridis, respectively. The sterile cultivation avoids algae and microorganism contamination, which are known limiting factors for plant normal growth and development in hydroponics. In addition, this system is scalable, enabling the harvest of plant material on a large scale with minor mechanical damage, as well as the harvest of individual parts of a plant if desired. A detailed protocol demonstrating that this system has an easy and low-cost assembly, as it uses pipette racks as the main platform for growing plants, is provided. The feasibility of this system was validated using Arabidopsis seedlings to assess the effect of the drug AZD-8055, a chemical inhibitor of the target of rapamycin (TOR) kinase. TOR inhibition was efficiently detected as early as 30 min after an AZD-8055 treatment in roots and shoots. Furthermore, AZD-8055-treated plants displayed the expected starch-excess phenotype. We proposed this hydroponic system as an ideal method for plant researchers aiming to monitor the action of plant inducers or inhibitors, as well as to assess metabolic fluxes using isotope-labeling compounds which, in general, requires the use of expensive reagents.

A simple, versatile, and low-cost in vitro hydroponic system was successfully optimized, enabling large-scale experiments under sterile conditions. This system facilitates the application of chemicals in a solution and their efficient absorption by roots for molecular, biochemical, and physiological studies.

Eine Flexible Low-Cost-Hydrokultur-System für die Bewertung der Pflanze Antworten auf kleine Moleküle unter sterilen Bedingungen

A wide range of studies in plant biology are performed using hydroponic cultures. In this work, an in vitro hydroponic growth system designed for ...

Experimental Protocol for Examining Behavioral Response Profiles in Larval Fish: Application to the Neuro-stimulant Caffeine

Fish models and behaviors are increasingly used in the biomedical sciences; however, fish have long been the subject of ecological, physiological and toxicological studies. Using automated digital tracking platforms, recent efforts in neuropharmacology are leveraging larval fish locomotor behaviors to identify potential therapeutic targets for novel small molecules. Similar to these efforts, research in the environmental sciences and comparative pharmacology and toxicology is examining various behaviors of fish models as diagnostic tools in tiered evaluation of contaminants and real-time monitoring of surface waters for contaminant threats. Whereas the zebrafish is a popular larval fish model in the biomedical sciences, the fathead minnow is a common larval fish model in ecotoxicology. Unfortunately, fathead minnow larvae have received considerably less attention in behavioral studies. Here, we develop and demonstrate a behavioral profile protocol using caffeine as a model neurostimulant. Though photomotor responses of fathead minnows were occasionally affected by caffeine, zebrafish&#160;were markedly more sensitive for photomotor and locomotor endpoints, which responded at environmentally relevant levels. Future studies are needed to understand comparative behavioral sensitivity differences among fish with age and time of day, and to determine whether similar behavioral effects would occur in nature and be indicative of adverse outcomes at the individual or population levels of biological organization.

Here, we present a protocol to examine larval zebrafish and fathead minnow locomotor activities and photomotor responses (PMR) using an automated tracking software. When incorporated in common toxicology bioassays, analyses of these behaviors provide a diagnostic tool to examine chemical bioactivity. This protocol is described using caffeine, a model neurostimulant.

Experimentelles Protokoll für die Prüfung Verhaltensreaktion Profile in Larval Fish: Anwendung auf die Neuro-Stimulans Koffein

Fish models and behaviors are increasingly used in the biomedical sciences; however, fish have long been the subject of ecological, physiological and ...

Design and Use of an Apparatus for Quantifying Bivalve Suspension Feeding at Sea

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves (i.e., mussels, oysters, and clams) presents new challenges. Quantitative data on the feeding behavior of suspension-feeding mollusks is necessary to determine important ecosystem interactions of offshore shellfish farms, including their carrying capacity, the competition with the zooplankton community, the availability of trophic resources at different depths, and the deposition to the benthos. The biodeposition method is used to quantify feeding variables in suspension-feeding bivalves in a natural setting and represents a more realistic proxy than laboratory experiments. This method, however, relies upon a stable platform to satisfy the requirements that water flow rates supplied to the shellfish remain constant and the bivalves are undisturbed. A flow-through device and process for using the biodeposition method to quantify the feeding of bivalve mollusks were modified from a land-based format for shipboard use by building a two-dimensional gimbal table around the device. Planimeter data reveal a minimal pitch and yaw of the chambers containing the test shellfish despite boat motion, the flow rates within the chambers remain constant, and operators are able to collect the biodeposits (feces and pseudofeces) with sufficient consistency to obtain accurate measurements of the bivalve clearance, filtration, selection, ingestion, rejection, and absorption at offshore shellfish aquaculture sites.

A flow-through device for using the biodeposition method to quantify filtration and feeding behavior of bivalve mollusks was modified for shipboard use. A two-dimensional gimbal table built around the device isolates the apparatus from boat motion, thereby allowing the accurate quantification of bivalve filtration variables at offshore shellfish aquaculture sites.

Gestaltung und Nutzung eines Apparates zur Quantifizierung der zweischaligen Suspension Fütterung auf hoher See

As shellfish aquaculture moves from coastal embayments and estuaries to offshore locations, the need to quantify ecosystem interactions of farmed bivalves ...