<h2 class="jove_title"><a href="https://www.jove.com/video/2976">Calcium imaging of odor-evoked responses in the Drosophila antennal lobe</a></h2>
Ana F. Silbering1, Rati Bell1, C. Giovanni Galizia2, Richard Benton1 1Center for Integrative Genomics, University of Lausanne, 2Department of Biology, University of Konstanz
We describe an established technique to measure and analyze odor-evoked calcium responses in the antennal lobe of living Drosophila melanogaster.
<h2 class="jove_title"><a href="https://www.jove.com/video/3413">Determining the Contribution of the Energy Systems During Exercise</a></h2>
Guilherme G. Artioli1, R&#244;mulo Bertuzzi2, Hamilton Roschel1, 3, Sandro H. Mendes1, Antonio H. Lancha1, Emerson Franchini4 1Laboratory of Applied Nutrition, School of Physical Education and Sport, University of Sao Paulo, 2Aerobic Performance Research Group, School of Physical Education and Sport, University of Sao Paulo, 3Laboratory of Neuromuscular Adaptations to Strength Training, School of Physical Education and Sport, University of Sao Paulo, 4Martial Arts and Combat Sports Research Group, School of Physical Education and Sport, University of Sao Paulo
This protocol allows researchers focused on exercise and sports sciences to determine the relative contribution of three different energy systems to the total energy expenditure during a large variety of exercises.
<h2 class="jove_title"><a href="https://www.jove.com/video/3629">High and Low Throughput Screens with Root-knot Nematodes Meloidogyne spp.</a></h2>
Hagop S. Atamian, Philip A. Roberts, Isgouhi Kaloshian Department of Nematology, University of California, Riverside 
Two distinct methods to screen plants with root-knot nematodes are described. The described approaches include high-throughput screens with nematodes in a nondestructive manner facilitating the use of these plants in breeding programs.
<h2 class="jove_title"><a href="https://www.jove.com/video/3681">Creating Transient Cell Membrane Pores Using a Standard Inkjet Printer</a></h2>
Alexander B. Owczarczak, Stephen O. Shuford, Scott T. Wood, Sandra Deitch, Delphine Dean Department of Bioengineering, Clemson University
A description of the methods used to convert an HP DeskJet 500 printer into a bioprinter. The printer is capable of processing living cells, which causes transient pores in the membrane. These pores can be utilized to incorporate small molecules, including fluorescent G-actin, into the printed cells.
<h2 class="jove_title"><a href="https://www.jove.com/video/3704">Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure</a></h2>
Evyn Loucks1, Sara Ahlgren1, 2 1Program in Developmental Biology, Children's Memorial Research Center, 2Department of Pediatrics, Northwestern University
In order to understand the molecular mechanisms of the ethanol-induced developmental damage, we have developed a zebrafish model of ethanol exposure and are exploring the physical, cellular, and genetic alterations that occur after ethanol exposure1. We then seek to find potential interventions and rapidly test them in this animal model.
<h2 class="jove_title"><a href="https://www.jove.com/video/3795">Methods to assay Drosophila behavior</a></h2>
Charles D. Nichols1, Jaime Becnel1, Udai B. Pandey2 1Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 2Department of Genetics, Louisiana State University Health Sciences Center
Drosophila melanogaster is a genetically and behaviorally tractable model system that has been used to understand the molecular and cellular basis of many important biological processes for over a century1. Drosophila has been well exploited to gain insights into the genetic basis of fly behavior.
<h2 class="jove_title"><a href="https://www.jove.com/video/3821">Fruit Volatile Analysis using an Electronic Nose</a></h2>
Simona Vallone1, Nathan W. Lloyd2, Susan E. Ebeler3, Florence Zakharov1 1Department of Plant Sciences, University of California, Davis, 2Department of Chemical Engineering and Material Science, University of California, Davis, 3Department of Viticulture and Enology, University of California, Davis
A rapid method for volatile compound analysis in fruit is described. The volatile compounds present in the headspace of a homogenate of the sample are rapidly separated and detected with ultra-fast gas chromatography (GC) coupled with a surface acoustic wave (SAW) sensor. A procedure for data handling and analysis is also discussed.

الإعلان عن أي تضارب في المصالح.

march 2012: this month in jove

The March issue of the Journal of Visualized Experiments (JoVE) begins with an article that focuses on three fundamentally important assays for measuring Drosophila locomotor behavior. Specifically, these assays include the larval crawling assay (for larval motor function), the RING assay (for adult motor function), and the courtship assay (to assess coordination and sensory abilities).
The larval crawling assay involves collection of larva and exposure of the juvenile flies to an experimental drug of interest. Animals are then transferred to a petri dish laid atop a sheet of graph paper, and the number of gridlines crossed per minute can be calculated.
The Rapid Iterative Negative Geotaxis, or RING, protocol, involves placing adult flies in specialized vials where they are forced to the bottom by gentle tapping. Fruit flies instinctively will crawl upward, against gravity. Through image analysis, the extent of adult locomotor ability can be determined by measuring how far upward the flies can climb in a short period of time.
To assess a more complex sensory-guided behavior, the courtship assay is used and begins by placing sexually-na&iuml;ve males and females into a specialized apparatus known as the mating wheel. During experimental sessions, investigators record the amount of time in which the male fly exhibits several characteristic courtship behaviors. Impressively, within a matter of minutes, the male fly will orient himself toward the female, tap her abdomen, generate a song with his wing, lick the female and ultimately copulate.
Taken together, these assays represent a series of powerful behavioral tests that can help elucidate the genetic and environmental factors that contribute to drosophila behavior.
Later in the month, JoVE shifts its focus to exercise physiology, where investigators from the University of Sau Paulo present a method designed to uncover the contribution of the various energy systems to complex exercise, like sports. As an example, our authors have chosen judo for their demonstration. Using a carefully positioned portable gas analyzer, oxygen consumption can be measured during judo exercise under controlled conditions. By comparing oxygen consumption before, during, and after exercise, the energy contribution of aerobic and alactic anaerobic metabolism can be determined. Blood collection before and after exercise, followed by electrochemical analysis is used to determine the energy contribution of lactic anaerobic metabolism to the sport of judo. When combined, oxygen consumption and plasma lactate concentration data, can be used to determine the relative contributions of the different energy systems to specific aspects of complex exercise, like one's favorite judo throw.
Also in March, JoVE plans the release of a developmental study involving alcohol exposure in zebrafish. Once embryos develop to the desired timepoint, the effects of alcohol exposure on gene expression can be assessed by purifying mRNA and performing qPCR and by whole mount in situ hybridization. Using light microscopy, morphological changes such as somite shape can also be assessed. If a gene of interest is observed to decrease or increase by ethanol exposure, either capped mRNA or morpholino can be injected into the embryo, somewhere around the two-cell stage, in order to rescue the alcohol-induced phenotype. Our authors show that alcohol exposure in the developing zebrafish results in similar morphological phenotypes and gene expression profiles to that observed in mammals, and they also demonstrate that mRNA injection can reverse the effects of alcohol on developmental abnormalities.
In Immunology and Infection, JoVE presents an experiment in plant parasitology, from UC Riverside. In particular, our authors are interested in the root knot nematode - an obligate plant parasite that moves freely through wet soil to infect the roots of plants, and feed. First, methods are described for processing infected plants and collection of root knot nematodes. Once juvenile worms develop to a stage with high infectivity, soil can be inoculated. Later, roots can be stained and assessed for the presence of the characteristic root knots generated by these parasites. In addition to experiments with potted plants, our authors show how root knot assays can be conducted with plants grown in clear pouches, allowing for easy viewing of roots, and facilitating high throughput screening for the presence of this devastating infection that accounts for 5% of global crop loss, yearly.
This summary of JoVE's content for March highlights four of over fifty articles scheduled for release in the month. Other notable experiments involve methods for imaging odor-evoked responses in the antenna of fruit flies, using an electronic nose to analyze the volatile compounds from fruit, and the repurposing of ordinary office equipment for the delivery of macromolecules into living cells.

Watch this Scientific Journal Video about March 2012: This Month in JoVE at JoVE.com

March 2012: This Month in JoVE

مارس 2012: من هذا الشهر في [جوف]

The March issue of the Journal of Visualized Experiments (JoVE) begins with an article that focuses on three fundamentally important assays for measuring ...

Research

JoVE Journal

Biology

Video: March 2012: This Month in JoVE

August 2012: This Month in JoVE

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens free lens-free "on-chip" microscopy platform, which they have pioneered.
Back in 2009, the Ozcan lab published their first article, which demonstrated the use of a lens-free imaging platform that could image cells within whole blood. This imaging technique involves placing a sample directly on an optoelectric sensor array, like the CCD or CMOS chips found in the standard camcorder. Then, LED illumination from above the sample casts shadows on the chip, which are recorded as digital holograms that can be subjected to image processing. Not only does this lensless imaging system allow for an extremely large field of view (FOV of 0.6-8 cm2), the lack of bulky optical components makes it excellent for microfluidic applications. The Ozcan group demonstrates this in their follow-up 2011 JoVE article, in which fluorescently labeled white blood cells are imaged within a microfluidic chip.
This August in JoVE, the Ozcan group demonstrates further advancements to their lens-free microscopy platform by applying it to tomographic imaging of the nematode, C. elegans. By changing the angle of illumination, using a motorized rotation stage, the Ozcan group shows how multiple holographic slices may be generated for a sample-which, following processing, can be combined into tomograms. The Ozcan group confirms that their 3D reconstruction of the worm is successful by citing that the pharyngeal tube, a 5-micron-thick structure, is only visible in a single slice and in a 3D reconstructed cross section.
The compact and inexpensive nature of the lens-free imaging systems - designed and assembled by the Ozcan group - make them well suited for point-of-care diagnostic applications, or even cell phone based microscopy that can be performed in the field.
At the Ernest Gallo Clinic and Research Center at University of California, San Francisco JoVE learns how to visualize morphological changes in single cells using three-dimensional fluorescence microscopy and computer analysis. In this procedure, cells are given agonist, antagonist plus agonist, or no treatment, and prepared for immunofluorescence microscopy. Three-dimensional images are acquired with the help of a two-photon laser system, and the fluorescence data are processed on the computer using Imaris and Matlab.
To demonstrate the power of this technique, our authors quantify single-cell phenotypic changes in transfected HEK293 cells. Three-dimensional morphometric analysis shows dramatic changes in cells treated with agonist. These changes are not always apparent when using conventional 2D analysis. This technique allows morphological changes in single cells to be quantified and characterized in response to pharmacologic stimuli, offering a powerful new assessment tool to the arsenal of drug discovery research.
This month, in JoVE Applied Physics, we travel to South Carolina to visit the School of Materials Science and Engineering at Clemson University. Here, researchers show us how to construct lithium batteries for laboratory research.
The basic components of a lithium coin cell are the working electrode, the lithium electrolyte, and a lithium foil counter electrode. The different components of the coin cell are carefully assembled and sealed with a crimping machine. The finished coin cell can then be characterized in a battery tester. Using their homemade coin cells, our researchers can experiment with using different materials to make the cathodes of lithium coin cells.
This month in JoVE Immunology and Infection, we head to Basel, Switzerland to witness two techniques for diagnosing helminth infections. We also see how investigators perform the shuttle run test in children, in order to assess the effects of these infections on physical fitness.
Helminths are parasitic worms that can live inside humans and animals. Many species infect the intestinal tract, and may be transmitted through soil. Our authors demonstrate the Kato-Katz technique, which is used for diagnosing several common soil-transmitted helminths. They also demonstrate the Baermann technique, which uses light to stimulate the migration of certain types of phototactic helminths out of sample preparations. The various types of helminth species can subsequently be determined based on morphology.
Our authors then demonstrate how to set up and perform a 20-meter shuttle run test for children, and to measure the impact of helminth infections on physical fitness. This method can help determine the true burden of soil-transmitted helminth infections on overall health.
This brief summary highlights but a few notable video-articles that will be released in August. We'll also feature articles that demonstrate how to express genes in the midbrain of the chick embryo, study neutrophil transmigration in parallel flow chambers lined with endothelial cells, and precisely measure proteolytic degradation of the extracellular matrix.

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and mirrors to refract and direct light to optical sensors. The August 2012 issue of JoVE (Journal of Visualized Experiments) is marked by the third publication from the Ozcan Lab (University of California, Los Angeles) on their lens-free "on-chip" microscopy platform, which they have pioneered.

أغسطس 2012: من هذا الشهر في [جوف]

Traditional microscopy requires lens objectives to magnify specimens, and can involve numerous optical components like additional objectives, filters, and ...

2012: A Year In Review

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE reached a major milestone by publishing our 1500th article. In this publication, in JoVE Bioengineering, Yu et al. described a method for analyzing the free radical composition of cigarette smoke. This method simulated cigarette puffing with a single-port smoking device, and combined it with electron spin resonance (ESR) spectroscopy to measure the degree to which antioxidant compounds can scavenge free radicals in cigarette smoke. A possible outcome of this research is the creation of less harmful cigarettes.
JoVE Bioengineering also contained the most-viewed article of 2012. Owczarczak et al. described a method for hacking a standard inkjet printer, loading ink cartridges with a cell-suspension "bioink," and printing lines of live cells onto glass slides. The thermal inkjet printing process creates temporary pores in the cell membrane, visualized by the incorporation of fluorescently labeled actin monomers. This concept, called "bioprinting," has many potential applications in cell and tissue engineering.
Also in 2012, JoVE Bioengineering featured a protocol by Hsia et al. for isolating and purifying spider silk protein, spinning it into fibers, and assessing the fiber strength. This protocol for laboratory-scale production of spider silk, which is stronger than tensile steel, can potentially be extended to large-scale manufacturing.
In JoVE Clinical and Translational Medicine, we featured a number of articles related to stroke, one of which. In one article, M&ouml;bius-Winkler et al. demonstrated placement of the WATCHMAN left atrial appendage occlusion device from Boston Scientific. This device is designed to prevent strokes by trapping clots within the left atrial appendage of the heart before they exit. Our authors demonstrated how to insert the guide wire through the femoral artery into the heart, advance the device into the left atrium, and deploy the device in the left atrial appendage.
Another article focused on stroke, Hamel et al. described the use of a driving simulator to study how patients compensate for visual field defects following stroke. By analyzing the compensatory gaze behavior of patients as they navigated through virtual driving courses with varying degrees of complexity, our authors see great potential for the use of driving simulators in stroke rehabilitation.
In JoVE Immunology and Infection, we published an article by Keyel et al. describing the real-time kinetics of immune cell responses to bacterial toxins using live cell microscopy. Combined with high-speed 3D confocal microscopy, this technique can also visualize the cellular repair response.
Also in JoVE Immunology and Infection, we featured an article by Yap et al. describing methods for diagnosing helminth infections in children. Helminths are parasitic worms that can infect the intestinal tract of humans and animals, and may be distinguished based on their morphology. The same article demonstrated how to measure the impact of helminth infections on physical fitness in children, which is a measure of overall health.
In JoVE Neuroscience, we featured a method by Hoffmann et al., who used tiny headphones to alter the auditory feedback in songbirds, and analyzed the computational and neurophysiological basis of vocal learning in birds when they adjust their singing in response to altered acoustic signals.
Also in JoVE Neuroscience, we moved from birds to bees with a method that assesses associative and non-associative tactile learning in honeybees. This method, by Mujagi&#263; et al., allowed bees to scan different metal surfaces with their antennae, then conditioned them to expect sugar water when their antennae touched particular surfaces, and analyzed the corresponding changes in antennal movement.
In 2012, we launched a brand-new section: JoVE Applied Physics, which features articles on subjects ranging from plasma physics to material science. The Applied Physics section also contained JoVE's 2000th video article, filmed in a synchrotron radiation facility, where Borisenko et al. showed how to determine the electronic structure of complex materials using angle-resolved photoemission spectroscopy.
In the JoVE General section, we published an article by Artioli et al. demonstrating the use of a portable gas analyzer to measure oxygen consumption during complex exercise - such as judo. By analyzing oxygen consumption and collecting blood for measuring plasma lactate concentration, this method can determine the relative contributions of different energy systems to specific aspects of complex exercise.
Finally, JoVE followed Dolhi et al. to a permanently ice-covered saline lake in Antarctica. There, scientists drilled through the ice to study single-celled microorganisms called protists that live in the harsh conditions of Antarctica.
This Year in Review was just a brief glimpse of a few of over 600 video articles that JoVE offered in 2012. Browse the JoVE archives to see thousands of other videos, and stay tuned for what's coming up this year in JoVE: The Journal of Visualized Experiments.

Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).

2012: A السنة قيد الاستعراض

 
 
Here's a look at some of the milestones and highlights of the year 2012 in Journal of Visualized Experiments (JoVE).
At the start of 2012, JoVE ...

مارس 2012: من هذا الشهر في [جوف]

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أغسطس 2012: من هذا الشهر في [جوف]

2012: A السنة قيد الاستعراض