<h2 class="jove_title"><a href="https://www.jove.com/video/56571">A Millimeter Scale Flexural Testing System for Measuring the Mechanical Properties of Marine Sponge Spicules</a></h2>Michael A. Monn, Jarod Ferreira, Jianzhe Yang, Haneesh Kesari<a href='/institutions/NA-North-America/US-United-States/RI-Rhode-Island/25069-Brown-University'>School of Engineering, Brown University</a>We present a protocol for performing three-point bending tests on sub-millimeter scale fibers using a custom-built mechanical testing device. The device can measure forces ranging from 20 &#181;N up to 10 N and can therefore accommodate a variety of fiber sizes.<h2 class="jove_title"><a href="https://www.jove.com/video/56233">The Other End of the Leash: An Experimental Test to Analyze How Owners Interact with Their Pet Dogs</a></h2>Giulia Cimarelli1,2,3, Borb&#225;la Turcs&#225;n1,4, Friederike Range1,2, Zs&#243;fia Vir&#225;nyi1,21<a href='/institutions/EU-Europe/AT-Austria/370-Medical-University-of-Vienna'>Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine of Vienna, Medical University of Vienna, University of Vienna</a>, 2<a href='/institutions/EU-Europe/AT-Austria/26053-Wolf-Science-Center'>Wolf Science Center, Messerli Research Institute, University of Veterinary Medicine of Vienna, Medical University of Vienna, University of Vienna</a>, 3<a href='/institutions/EU-Europe/AT-Austria/25818-University-of-Vienna'>Department of Cognitive Biology, University of Vienna</a>, 4<a href='/institutions/EU-Europe/HU-Hungary/26054-Hungarian-Academy-of-Sciences'>Research Centre for Natural Sciences, Institute of Cognitive Neuroscience and Psychology, Hungarian Academy of Sciences</a>This article presents eight different experimental tasks, mirroring the everyday life of dogs and owners, used to analyze how owners interact with their dogs in a standardized way. The tasks included both positive (e.g. play) and negative (potentially stressful) situations (e.g. physical restriction).<h2 class="jove_title"><a href="https://www.jove.com/video/56335">Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles</a></h2>Byung Hyo Kim1,2, Junyoung Heo1,2, Won Chul Lee3, Jungwon Park1,21<a href='/institutions/AS-Asia/KR-Korea,-Republic-of/26108-Institute-for-Basic-Science-(IBS)'>Center for Nanoparticle Research, Institute for Basic Science (IBS)</a>, 2<a href='/institutions/AS-Asia/KR-Korea,-Republic-of/25803-Seoul-National-University'>School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University</a>, 3<a href='/institutions/AS-Asia/KR-Korea,-Republic-of/26109-Hanyang-University'>Department of Mechanical Engineering, Hanyang University</a>Here we introduce experimental protocols for the real-time observation of a self-assembly process using liquid-cell transmission electron microscopy.<h2 class="jove_title"><a href="https://www.jove.com/video/55252">Building Double-decker Traps for Early Detection of Emerald Ash Borer</a></h2>Deborah G. McCullough1, Therese M. Poland21<a href='/institutions/NA-North-America/US-United-States/MI-Michigan/24938-Michigan-State-University'>Department of Entomology and Department of Forestry, Michigan State University</a>, 2<a href='/institutions/NA-North-America/US-United-States/CA-California/26157-USDA-Forest-Service'>Northern Research Station, USDA Forest Service</a>Effective traps to attract and capture the emerald ash borer (EAB) are a key element of detecting and managing this invasive pest. Double-decker traps, placed in full sun near ash trees, incorporate visual and olfactory cues and were more likely to capture EAB than other trap designs in field trials.

jove monthly highlights: october 2017

Here's a look at what's coming up in the October 2017 issue of <a href="http://www.jove.com/">JoVE: The World's Premier Video Journal</a>.
From the bubbling cauldron of science emerges our first featured article, from <a href="https://www.jove.com/journal/environment">JoVE Environment</a>. Here, <a href="https://www.jove.com/video/55252/building-double-decker-traps-for-early-detection-of-emerald-ash-borer">our Authors</a> demonstrate how to build and deploy double-decker traps to attract and capture emerald ash borers - the most destructive forest insect to invade North America. These traps capture significantly more emerald ash borers than any other trap type in sites with relatively low EAB densities, allowing for effective detection and management of this invasive insect. Even more than giant creepy spiderwebs!
Moving from pests to pets, our next study from <a href="https://www.jove.com/journal/behavior">JoVE Behavior</a> takes a look at man's best friend. Here, <a href="https://www.jove.com/video/56233/the-other-end-leash-an-experimental-test-to-analyze-how-owners">our Authors</a> describe eight different experimental tasks to analyze the relationship between dogs and their owners. The results of this standardized study suggest that owner warmth is the greatest source of behavioral variance - and that dogs belonging to more controlling owners tend to be more aggressive towards strangers. And good doggies get treats...no tricks!
Switching gears, in <a href="https://www.jove.com/journal/bioengineering">JoVE Bioengineering</a> this month <a href="https://www.jove.com/video/56571/a-millimeter-scale-flexural-testing-system-for-measuring-mechanical">our Authors</a> use a custom built mechanical testing device to measure the flexural behavior of load bearing biological structures. The successful execution of this three-point bending test on the skeletal elements from marine sponges shows that this method can be used to understand the remarkable mechanical functions of a host of similar structures. That's heavy stuff!
Finally, <a href="https://www.jove.com/journal/chemistry">JoVE Chemistry</a> zooms in on nanoparticle self-assembly processes in real time. Using uniformly sized platinum and lead selenide nanoparticles, <a href="https://www.jove.com/video/56335/liquid-cell-transmission-electron-microscopy-for-tracking-self">our Authors</a> produced liquid cells with silicon or silicon nitride or windows. Liquid-cell transmission electron microscopy analysis reveals that changes in the solvent boundaries, caused by evaporation, affects nanoparticle self-assembly by driving them to form amorphous aggregates. These aggregates then flatten, producing spellbinding two-dimensional self-assembled structures.
You've just had a sneak peek of the October 2017 issue of JoVE. Visit the website to see the full-length articles, plus many more, in <a href="http://www.jove.com/">JoVE: The World's Premier Video Journal</a>.

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JoVE Monthly Highlights: October 2017

Here's a look at what's coming up in the October 2017 issue of JoVE: The World's Premier Video Journal.
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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.

Ağustos 2012: Vallahi Bu Ay

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

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JoVE Journal

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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: İnceleme Bir Yıl

 
 
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 ...