<h2 class="jove_title"><a href="https://www.jove.com/video/50864">Methods for Studying the Mechanisms of Action of Antipsychotic Drugs in Caenorhabditis elegans</a></h2>
Limin Hao1,2, Edgar A. Buttner1,2
1Department of Psychiatry, Harvard Medical School, 2Mailman Research Center, McLean Hospital
Approaches for testing the effects of antipsychotic drugs (APDs) in Caenorhabditis elegans are demonstrated. Assays are described for testing drug effects on development and viability and on pharyngeal pumping rate. These methods are also applicable for pharmacogenetic experiments with drug classes other than APDs.
<h2 class="jove_title"><a href="https://www.jove.com/video/50898">Assessment of Calcium Sparks in Intact Skeletal Muscle Fibers</a></h2>
Ki Ho Park1, Noah Weisleder2, Jingsong Zhou3, Kristyn Gumpper1, Xinyu Zhou1, Pu Duann4, Jianjie Ma1, Pei-Hui Lin1
1Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 2Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, 3Department of Molecular Biophysics and Physiology, Rush University Medical Center, 4Department of Internal Medicine, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center
Described here is a method to directly measure calcium sparks, the elementary units of Ca2+ release from sarcoplasmic reticulum, in intact skeletal muscle fibers. This method utilizes osmotic-stress-mediated triggering of Ca2+ release from ryanodine receptor in isolated muscle fibers. The dynamics and homeostatic capacity of intracellular Ca2+ signaling can be employed to assess muscle function in health and disease.
<h2 class="jove_title"><a href="https://www.jove.com/video/50942">Assessment of Age-related Changes in Cognitive Functions Using EmoCogMeter, a Novel Tablet-computer Based Approach</a></h2>
Philipp Fuge*1,2, Simone Grimm*1,2,3,4, Anne Weigand1,2,3, Yan Fan1,3, Matti G&#228;rtner1,3, Melanie Feeser1,3, Malek Bajbouj1,2,3
1Cluster of Excellence &#34;Languages of Emotion&#34;, Freie Universit&#228;t Berlin, 2Department of Psychiatry, Campus Benjamin Franklin, Charit&#233; Berlin, 3Dahlem Institute for Neuroimaging of Emotion, Freie Universit&#228;t Berlin, 4Clinic for Affective Disorders and General Psychiatry, Psychiatric University Hospital Zurich
We tested the usability of a tablet-computer-based application (EmoCogMeter) in investigating the effects of age on cognition. Results show an age-related cognitive decline, thereby proving the usability of our application. Findings underline the great clinical and practical potential of a tablet-based application for detection and monitoring of cognitive dysfunction.
<h2 class="jove_title"><a href="https://www.jove.com/video/51080">Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp</a></h2>
Kelley C. Stewart1, Byron D. Erath2, Michael W. Plesniak1
1Department of Mechanical and Aerospace Engineering, The George Washington University, 2Department of Mechanical and Aeronautical Engineering, Clarkson University
Vocal fold polyps can disrupt vocal fold dynamics and thus can have devastating consequences on a patient&#39;s ability to communicate. Three-dimensional flow separation induced by a wall-mounted model polyp and its impact on the wall pressure loading are examined using particle image velocimetry, skin friction line visualization, and wall pressure measurements.
<h2 class="jove_title"><a href="https://www.jove.com/video/51223">An Improved Method for Accurate and Rapid Measurement of Flight Performance in Drosophila</a></h2>
Daniel T. Babcock, Barry Ganetzky
Department of Genetics, University of Wisconsin-Madison
Here we describe a method for rapid and accurate measurement of flight performance in Drosophila, enabling high-throughput screening.

february 2014: this month in jove

Here's a look at what's coming up in the <a href="http://www.jove.com/archive/84">February 2014 issue</a> of <a href="http://www.jove.com/">JoVE: The Journal of Visualized Experiments</a>.
This month, we have an improved method for studying the behavioral genetics of Drosophila melanogaster, or the common fruit fly. The classical test for Drosophila flight behavior was developed in the 1970s by famous fly geneticist Seymour Benzer. It involves dropping flies through a funnel into an oil-coated cylinder and seeing how far they fall before initiating flight and getting stuck in the oil. <a href="http://www.jove.com/video/51223">Babcock and Ganetzky</a> added several features to Benzer's assay, including a drop tube to ensure consistent entry velocity; removable, adhesive-coated acrylic sheets for easy recovery of live flies; and digital imaging to automate data collection. With these improvements, scientists can assess flight behavior quickly and quantitatively, and accommodate large-scale datasets and genetic screens.
We also take look at calcium ions (Ca2+), which are important and versatile intracellular messengers that mediate many cellular functions, especially in excitable cells like neurons and muscle. <a href="http://www.jove.com/video/50898">Park et al.</a> demonstrate a method for isolating skeletal muscle fibers and directly measuring distinct release events called "calcium sparks". This technique can be used to assess muscle function in normal, aged, and dystrophic muscle.
In <a href="http://www.jove.com/neuro">JoVE Neuroscience</a>, <a href="http://www.jove.com/video/50864">Hao and Buttner</a> show how the nematode worm C. elegans can be a powerful tool in pharmacogenetic research. These tiny worms are sensitive to many bioactive compounds, so scientists can expose the worms to various compounds and observe the pharmacological effects. Because it's relatively easy to tinker with C. elegans genes, this technique is useful for large-scale chemical genetic screens and for validating targets identified in other screens.
In <a href="http://www.jove.com/bioengineering">JoVE Bioengineering</a>, we focus on vocal folds, which modulate the airflow from the lungs to produce voice and speech. Abnormal growths, like polyps, can disrupt vocal fold dynamics and a person's ability to communicate. To understand the fluid dynamic effects of these growths, <a href="http://www.jove.com/video/51080">Stewart et al.</a> place a model vocal fold polyp in a wind tunnel and examine its effects using particle image velocimetry and other measurements. These techniques can improve the understanding vocal fold dynamics, which will in turn advance the treatment of voice and speech disorders.
In <a href="http://www.jove.com/behavior">JoVE Behavior</a>, we address the effects of aging on cognition. <a href="http://www.jove.com/video/50942">Fuge et al.</a> use a tablet-based computer application to study age-related cognitive decline. Through a series of cognitive tasks, the application demonstrates great clinical and practical potential for detecting and monitoring cognitive dysfunction.
You've just had a sneak peek of the <a href="http://www.jove.com/archive/84">February 2014 issue</a> of JoVE. Visit the website to see the full-length articles, plus many more, in <a href="http://www.jove.com/">JoVE: The Journal of Visualized Experiments</a>.

Watch this Scientific Journal Video about February 2014: This Month in JoVE at JoVE.com

February 2014: This Month in JoVE

Here's a look at what's coming up in the <a href="http://www.jove.com/archive/84">February 2014</a> issue of JoVE.

Here's a look at what's coming up in the February 2014 issue of JoVE: The Journal of Visualized Experiments.
This month, we have an improved method for ...

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2.1K visualizações.  Massachusetts Eye and Ear. Here's a look at what's coming up in the February 2014 issue of JoVE.

Vídeo: February 2014: 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.

Agosto 2012: Este mês na JOVE

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

Research

JoVE Journal

Biologia

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: Um ano em análise

 
 
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 ...