2012: A Year In Review

Summary

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

Protocol

A Protocol for Detecting and Scavenging Gas-phase Free Radicals in Mainstream Cigarette Smoke

Long-Xi Yu¹, Boris G. Dzikovski², Jack H. Freed^{3, 2
1}CDCF-AOX Lab, ²National Biomedical Center for Advanced ESR Technology (ACERT), Department of Chemistry and Chemical Biology, Cornell University, ³ACERT Research, Center Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University

Spin-trapping ESR spectroscopy was used to study the effect of plant antioxidants lycopene, pycnogenol and grape seed extract on scavenging gas-phase free radicals in cigarette smoke.

The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation

Sven Möbius-Winkler, Marcus Sandri, Norman Mangner, Phillip Lurz, Ingo Dähnert, Gerhard Schuler
University of Leipzig Heart Center

The accompanying video describes a procedure for percutaneous placement of the WATCHMAN Left Atrial Appendage (LAA) Device. The WATCHMAN is a nitinol device designed to be permanently implanted at, or slightly distal to, the opening of the left atrial appendage (LAA) to trap blood clots before they exit the LAA, preventing thromboembolic stroke.

Determining the Contribution of the Energy Systems During Exercise

Guilherme G. Artioli¹, Rômulo C. Bertuzzi², Hamilton Roschel^{1, 3}, Sandro H. Mendes¹, Antonio H. Lancha Jr.¹, Emerson Franchini^4
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.

Establishment of Microbial Eukaryotic Enrichment Cultures from a Chemically Stratified Antarctic Lake and Assessment of Carbon Fixation Potential

Jenna M. Dolhi, Nicholas Ketchum, Rachael M. Morgan-Kiss
Department of Microbiology, Miami University

Microbial eukaryotes are both a source of photosynthetically-derived carbon and top predatory species in permanently ice-covered Antarctic lakes. This report describes an enrichment culture approach to isolate metabolically versatile microbial eukaryotes from the Antarctic lake, Lake Bonney, and assesses inorganic carbon fixation potential using a radioisotope assay for Ribulose-1,5-bisphophate carboxylase oxygenase (RubisCO) activity.

Synthetic Spider Silk Production on a Laboratory Scale

Yang Hsia, Eric Gnesa, Ryan Pacheco, Kristin Kohler, Felicia Jeffery, Craig Vierra
Department of Biological Sciences, University of the Pacific

Despite the outstanding mechanical and biochemical properties of spider silks, this material cannot be harvested in large quantities by conventional means. Here we describe an efficient strategy to spin artificial spider silk fibers, which is an important process for investigators studying spider silk production and their use as next-generation biomaterials.

Determining Soil-transmitted Helminth Infection Status and Physical Fitness of School-aged Children

Peiling Yap^{1, 2}, Thomas Fürst^{1, 2}, Ivan Müller^{1, 2}, Susi Kriemler^{1, 2}, Jürg Utzinger^{1, 2}, Peter Steinmann^{1, 2
1}Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland, ²University of Basel, Basel, Switzerland

Chronic infection with soil-transmitted helminths (STHs) causes malabsorption, stunting, and wasting in the growing child. Hence, it is plausible that these infections also reduce the physical fitness of children. Here, we visualize two techniques for the diagnosis of STHs and the 20-meter shuttle run test for assessing children's physical fitness.

Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects

Johanna Hamel^{1, 2}, Antje Kraft¹, Sven Ohl³, Sophie De Beukelaer¹, Heinrich J. Audebert^{1, 2}, Stephan A. Brandt^1
1Department of Neurology, Universitätsmedizin Charité, ²Center for Stroke Research Berlin (CSB), Universitätsmedizin Charité, ³Berlin School of Mind and Brain, Humboldt Universität zu Berlin

Patients with visual deficits after stroke report about different constraints in daily life most likely due to variable compensatory strategies, which are difficult to differentiate in clinical routine. We present a clinical set-up which allows measurement of different compensatory head- and eye-movement-strategies and evaluating their effects on driving performance.

Visualization of Bacterial Toxin Induced Responses Using Live Cell Fluorescence Microscopy

Peter A. Keyel¹, Michelle E. Heid¹, Simon C. Watkins², Russell D. Salter^1
1Department of Immunology, University of Pittsburgh School of Medicine, ²Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine

Methods for purifying the cholesterol binding toxin streptolysin O from recombinant E. coli and visualization of toxin binding to live eukaryotic cells are described. Localized delivery of toxin induces rapid and complex changes in targeted cells revealing novel aspects of toxin biology.

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures

Sergey V. Borisenko¹, Volodymyr B. Zabolotnyy¹, Alexander A. Kordyuk^{1, 2}, Danil V. Evtushinsky¹, Timur K. Kim^{1, 3}, Emanuela Carleschi⁴, Bryan P. Doyle⁴, Rosalba Fittipaldi⁵, Mario Cuoco⁵, Antonio Vecchione⁵, Helmut Berger^6
1Institute for Solid State Research, IFW-Dresden, ²Institute of Metal Physics of National Academy of Sciences of Ukraine, ³Diamond Light Source LTD, ⁴Department of Physics, University of Johannesburg, ⁵CNR-SPIN, and Dipartimento di Fisica "E. R. Caianiello", Università di Salerno, ⁶Institute of Physics of Complex Matter, École Polytechnique Fédérale de Lausanne

The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.

A Lightweight, Headphones-based System for Manipulating Auditory Feedback in Songbirds

Lukas A. Hoffmann^{1, 2}, Conor W. Kelly^{1, 3}, David A. Nicholson^{1, 2}, Samuel J. Sober^1
1Department of Biology, Emory University, ²Neuroscience Graduate Program, Emory University, ³Program in Neuroscience and Behavioral Biology, Emory University

We describe the design and assembly of miniaturized headphones suitable for replacing a songbird's natural auditory feedback with a manipulated acoustic signal. Online sound processing hardware is used to manipulate song output, introduce real-time errors in auditory feedback via the headphones, and drive vocal motor learning.

Tactile Conditioning And Movement Analysis Of Antennal Sampling Strategies In Honey Bees (Apis mellifera L.)

Samir Mujagić, Simon Michael Würth, Sven Hellbach, Volker Dürr
Biological Cybernetics, CITEC - Cognitive Interaction Technology - Center of Excellence, Bielefeld University

In this protocol we show how to condition harnessed honey bees to tactile stimuli and introduce a 2D motion capture technique for analyzing the kinematics of fine-scale antennal sampling pattern.