7,888 research outputs found

    Characterization of slow and fast phase nystagmus

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    A current literature review of the analog and digital process of vestibular and optical kinetic nystagmus reveals little agreement in the methods used by various labs. The strategies for detection of saccade (fast phase velocity component of nystagmus) vary between labs, and most of the process have not been evaluated and validated with a standard database. A survey was made of major vestibular labs in the U.S. that perform computer analyses of vestibular and optokinetic reflexes to stimuli, and a baseline was established from which to standardize data acquisition and analysis programs. The concept of an Error Index was employed as the criterium for evaluating the performance of the vestibular analysis software programs. The performance criterium is based on the detection of saccades and is the average of the percentages of missed detections and false detections. Evaluation of the programs produced results for lateral gaze with saccadic amplitude of one, two, three, five, and ten degrees with various signal-to-noise ratios. In addition, results were obtained for sinusoidal pursuit of 0.05, 0.10, and 0.50 Hz with saccades from one to ten degrees at various signal-to-noise ratios. Selection of the best program was made from the performance in the lateral gaze with three degrees of saccadic amplitude and in the 0.10 Hz sinusoid with three degrees of saccadic amplitude

    Train Like an Astronaut Educational Outreach

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    In an effort to reduce the incidence of childhood obesity, the National Aeronautics and Space Administration (NASA), capitalizing on the theme of human spaceflight developed two educational outreach programs for children ages 8-12. To motivate young "fit explorers," the Train Like an Astronaut National (TLA) program and the Mission X: Train Like an Astronaut International Fitness Challenge (MX) were created. Based on the astronauts' physical training, these programs consist of activities developed by educators and experts in the areas of space life sciences and fitness. These Activities address components of physical fitness. The educational content hopes to promote students to pursue careers in science, technology, engineering, and math (STEM) fields. At the national level, in partnership with First Lady Michelle Obama's Let?s Move! Initiative, the TLA program consists of 10 physical and 2 educational activities. The program encourages families, schools, and communities to work collaboratively in order to reinforce in children and their families the importance of healthy lifestyle habits In contrast, the MX challenge is a cooperative outreach program involving numerous space agencies and other international partner institutions. During the six-week period, teams of students from around the world are challenged to improve their physical fitness and collectively accumulate points by completing 18 core activities. During the 2011 pilot year, a t otal of 137 teams and more than 4,000 students from 12 countries participated in the event. MX will be implemented within 24 countries during the 2012 challenge. It is projected that 7,000 children will "train like an astronaut"

    Assessing the Gene Content of the Megagenome: Sugar Pine (Pinus lambertiana).

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    Sugar pine (Pinus lambertiana Douglas) is within the subgenus Strobus with an estimated genome size of 31 Gbp. Transcriptomic resources are of particular interest in conifers due to the challenges presented in their megagenomes for gene identification. In this study, we present the first comprehensive survey of the P. lambertiana transcriptome through deep sequencing of a variety of tissue types to generate more than 2.5 billion short reads. Third generation, long reads generated through PacBio Iso-Seq have been included for the first time in conifers to combat the challenges associated with de novo transcriptome assembly. A technology comparison is provided here to contribute to the otherwise scarce comparisons of second and third generation transcriptome sequencing approaches in plant species. In addition, the transcriptome reference was essential for gene model identification and quality assessment in the parallel project responsible for sequencing and assembly of the entire genome. In this study, the transcriptomic data were also used to address questions surrounding lineage-specific Dicer-like proteins in conifers. These proteins play a role in the control of transposable element proliferation and the related genome expansion in conifers

    Wintering Area DDE Source to Migratory White-Faced Ibis Revealed by Satellite Telemetry and Prey Sampling

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    Locations of contaminant exposure for nesting migratory species are difficult to fully understand because of possible additional sources encountered during migration or on the wintering grounds. A portion of the migratory white-faced ibis (Plegadis chihi) nesting at Carson Lake, Nevada continues to be exposed to dichloro-diphenyl-dichloroethylene (DDE) with no change, which is unusual, observed in egg concentrations between 1985 and 2000. About 45 to 63% of the earliest nesting segment shows reduced reproductive success correlated with elevated egg concentrations of \u3e 4 µg/g wet weight (ww). Local prey (primarily earthworms) near nests contained little DDE so we tracked the migration and wintering movements of 20 adult males during 2000-2004 to determine the possible source. At various wintering sites, we found a correlation (r2 = 0.518, P = 0.0125, N = 11) between DDE in earthworm composites and DDE in blood plasma of white-faced ibis wintering there, although the plasma was collected on their breeding grounds soon after arrival. The main source of DDE was wintering areas in the Mexicali Valley of Baja California Norte, Mexico, and probably the adjacent Imperial Valley, California, USA. This unusual continuing DDE problem for white-face ibis is associated with: the long-term persistence in soil of DDE; the earthworms’ ability to bioconcentrate DDE from soil; the proclivity of white-faced ibis to feed on earthworms in agricultural fields; the species extreme sensitivity to DDE in their eggs; and perhaps its life history strategy of being a “capital breeder”. We suggest surveying and sampling white-faced ibis eggs at nesting colonies, especially at Carson Lake, to monitor the continuing influence of DDE

    Report of the 1988 2-D Intercomparison Workshop, chapter 3

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    Several factors contribute to the errors encountered. With the exception of the line-by-line model, all of the models employ simplifying assumptions that place fundamental limits on their accuracy and range of validity. For example, all 2-D modeling groups use the diffusivity factor approximation. This approximation produces little error in tropospheric H2O and CO2 cooling rates, but can produce significant errors in CO2 and O3 cooling rates at the stratopause. All models suffer from fundamental uncertainties in shapes and strengths of spectral lines. Thermal flux algorithms being used in 2-D tracer tranport models produce cooling rates that differ by as much as 40 percent for the same input model atmosphere. Disagreements of this magnitude are important since the thermal cooling rates must be subtracted from the almost-equal solar heating rates to derive the net radiative heating rates and the 2-D model diabatic circulation. For much of the annual cycle, the net radiative heating rates are comparable in magnitude to the cooling rate differences described. Many of the models underestimate the cooling rates in the middle and lower stratosphere. The consequences of these errors for the net heating rates and the diabatic circulation will depend on their meridional structure, which was not tested here. Other models underestimate the cooling near 1 mbar. Suchs errors pose potential problems for future interactive ozone assessment studies, since they could produce artificially-high temperatures and increased O3 destruction at these levels. These concerns suggest that a great deal of work is needed to improve the performance of thermal cooling rate algorithms used in the 2-D tracer transport models

    Microwave and Millimeter Wave Techniques

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    Contains reports on two research projects.Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Science Foundation (Grant AST77-26896

    Editorial: Remote Ischemic Conditioning (Pre, Per, and Post) as an Emerging Strategy of Neuroprotection in Ischemic Stroke

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    EDITORIAL articleThis study was funded by Carlos III Health Institute and cofunded by European Union (ERDF A way to make Europe) Project (PI17-01725) and the RICORS Research Network to FP, NIH Funding (R01 NS099455, 1UO1NS113356, and R01 NS112511) to DH, Italian Ministry of Health - PRIN 2017CY3J3W to SB. French National Minsitry of Health Grant 2014 AOR13032 to FP, TE is the Chief Investigator for the Remote ischaemic conditioning after stroke trial (RECAST), RECAST-2, and RECAST-3 funded through the NIHR Efficacy and Mechanism Evaluation (EME) Programme, Award ID NIHR128240

    Comparing adenoma and polyp miss rates for total underwater colonoscopy versus standard CO2: a randomized controlled trial using a tandem colonoscopy approach

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    Background and Aims Although water exchange may improve adenoma detection when compared to CO2, it is unclear whether water is a better medium to fill the lumen during withdrawal and visualize the mucosa. Total underwater (TUC) involves the use of water exchange with the air valve off during insertion followed by the inspection of the mucosa under water. Our goal was to use a tandem colonoscopy design to compare miss rates for TUC to standard CO2 for polyps and adenomas. Methods We randomized participants (NCT03231917; clinicaltrials.gov) to undergo tandem colonoscopies using TUC or CO2 first. In TUC, water exchange was performed during insertion and withdrawal was performed under water. For the CO2 colonoscopy both insertion and withdrawal were performed with CO2. The main outcomes were miss rates for polyps and adenomas for the first examination calculated as the number of additional polyps/adenomas detected during the second examination divided by the total number of polyps/adenomas detected for both examinations. Inspection times were calculated by subtracting time for polypectomy and care was given to keep the times equal for both examinations. Results A total of 121 participants were randomized with 61 having CO2 first. The overall miss rate for polyps was higher for the TUC first group (81/237; 34%) as compared to the CO2 first cohort (57/264; 22%)(p=0.002). In addition, the overall miss rate for all adenomas was higher for the TUC first group (52/146; 36%) as compared with the CO2 group (37/159; 23%) (p=0.025). However, 1 of the 3 endoscopists had higher polyp/adenoma miss rates for CO2 but these were not statistically significant differences. The insertion time was longer for TUC than CO2. After adjusting for times, participant characteristics and bowel preparation, the miss rate for polyps was higher for TUC than CO2. Conclusions We found that TUC had an overall higher polyp and adenoma miss rate than colonoscopy performed with CO2, and TUC took longer to perform. However, TUC may benefit some endoscopists, an issue that requires further study

    Composite Dissolving Microneedles for Coordinated Control of Antigen and Adjuvant Delivery Kinetics in Transcutaneous Vaccination

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    Transcutaneous administration has the potential to improve therapeutics delivery, providing an approach that is safer and more convenient than traditional alternatives, while offering the opportunity for improved therapeutic efficacy through sustained/controlled drug release. To this end, a microneedle materials platform is demonstrated for rapid implantation of controlled-release polymer depots into the cutaneous tissue. Arrays of microneedles composed of drug-loaded poly(lactide-co-glycolide) (PLGA) microparticles or solid PLGA tips are prepared with a supporting and rapidly water-soluble poly(acrylic acid) (PAA) matrix. Upon application of microneedle patches to the skin of mice, the microneedles perforate the stratum corneum and epidermis. Penetration of the outer skin layers is followed by rapid dissolution of the PAA binder on contact with the interstitial fluid of the epidermis, implanting the microparticles or solid polymer microneedles in the tissue, which are retained following patch removal. These polymer depots remain in the skin for weeks following application and sustain the release of encapsulated cargos for systemic delivery. To show the utility of this approach the ability of these composite microneedle arrays to deliver a subunit vaccine formulation is demonstrated. In comparison to traditional needle-based vaccination, microneedle delivery gives improved cellular immunity and equivalent generation of serum antibodies, suggesting the potential of this approach for vaccine delivery. However, the flexibility of this system should allow for improved therapeutic delivery in a variety of diverse contexts.Massachusetts Institute of Technology. Ragon Institute of MGH, MIT and HarvardNational Institutes of Health (U.S.) (Award AI095109)United States. Army Research Office (Contract W911NF-07-D-0004
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