Magnetostratigraphy and Clockwise Rotation of the Plio-Pleistocene Mojave River Formation, Central Mojave Desert, California

Oriented samples collected for paleomagnetic analysis from sediments of the newly-named Mojave River Formation (Nagy & Murray, 1991, this volume) possess stable characteristic components of Natural Remanent Magnetization (NRM). Progressive demagnetization reveals characteristic components of both normal and reversed polarity which are stratigraphically distinct. The oldest sediments exposed within the field area are reversely magnetized and were probably deposited during the early portion of the Matuyama reversed Chron. Stratigraphically higher units contain what appears to be the Olduvai normal Subchron, as well as a shorter normal zone which probably is either the Cobb Mountain or Jaramillo Event. The location of the Brunhes/Matuyama boundary at one site is within an alluvial fanglomerate which grades upward conformably into the lowest unit of the overlying Manix Formation, possibly accounting for the absence of the Bishop ash in the section. Demagnetization data from 143 samples yielding acceptable least-squares lines suggest a net clockwise rotation of 8 ± 2.7° over the past two million years, perhaps with some of the rotation during deposition. This rate of rotation could account easily for larger rotations reported elsewhere in the Mojave Desert on units of Miocene age

A COMPARISON OF RESISTED AND ASSISTED SPRINT TRAINING IN COLLEGIATE SPRINTERS

Sprint time (ST) is the product of stride length (SL) and stride rate (SR). Increases in either of these variables results in speed improvement. Purpose:  To compare resisted (RST) and assisted sprint training (AST) on sprint performance. Methods:  Twenty (10 male, 10 female) collegiate sprinters and hurdlers were randomly divided into two training groups: RST (age: 21.8±1.8yrs, height: 1.73±0.10m, mass: 69.5±12.8kg) and AST (age: 22.2±2.4yrs, height: 1.76±0.10m, mass: 69.1±9.9kg). Each group trained 3 days/week for 6 weeks. The RST group used a combination of weighted sled pulls, uphill sprinting and depth jumps. The AST group combined downhill running, towing, sprint ladders and single leg bounds. Prior to and following the training interventions SL and ST (10 meter sprint time) were recorded at sprint distances of 30m, 60m, and 120m during the last 10 meters of each sprint distance. Pre-post training ST and SL were compared within training groups at each sprint distance using paired t-tests. Additionally, a gain score was calculated by taking the difference between the post and pre test scores. The gain scores for SL and ST were compared between training groups via independent t-tests at each sprint distance. Results: For the RST 30m, ST (1.18±0.08s vs 1.14±0.08s, p<0.01) and SL (2.06±0.08m vs. 2.09±1.14m, p<0.01) were significantly improved. For the AST, 30m ST (1.19±0.08s vs. 1.18±0.08s, p<0.01) and SL (2.10±0.13m vs. 2.11±0.13, p=0.04) were significantly improved. No improvements in ST or SL were detected for either the RST or AST groups at the 60m sprint distance. For the RST 120m, ST (1.13±0.07s vs. 1.12±0.08s, p<0.01) was significantly improved. For the AST 120m, ST (1.12±0.07s vs. 1.11±0.07s, p<0.01) and SL (2.30±0.08 vs. 2.33±0.08, p<0.01) were significantly improved. At the 30M interval, the RST demonstrated significant improvements in SL and ST as compared to the AST (p<0.01). However, at the 120M interval, the AST demonstrated a significant improvement in SL as compared to the RST (p<0.01). Conclusion: Within the parameters of this study, RST and AST methods have proven effective at improving sprint performance. It appears that RST protocols may be of greatest benefit for improving sprint performance at shorter distances, while AST protocols may be of greater benefit at longer sprinting distances.  Article visualizations

Superconducting Films for Absorber-Coupled MKID Detectors for Sub-Millimeter and Far-Infrared Astronomy

We describe measurements of the properties, at dc, gigahertz, and terahertz frequencies, of thin (10 nm) aluminum films with 10 ohm/{rm square}$ normal state sheet resistance. Such films can be applied to construct microwave kinetic inductance detector arrays for submillimeter and far-infrared astronomical applications in which incident power excites quasiparticles directly in a superconducting resonator that is configured to present a matched-impedance to the high frequency radiation being detected. For films 10 nm thick, we report normal state sheet resistance, resistance-temperature curves for the superconducting transition, quality factor and kinetic inductance fraction for microwave resonators made from patterned films, and terahertz measurements of sheet impedance measured with a Fourier Transform Spectrometer. We compare properties with similar resonators made from niobium 600 nm thick

ViCTree: an automated framework for taxonomic classification from protein sequences

Motivation: The increasing rate of submission of genetic sequences into public databases is providing a growing resource for classifying the organisms that these sequences represent. To aid viral classification, we have developed ViCTree, which automatically integrates the relevant sets of sequences in NCBI GenBank and transforms them into an interactive maximum likelihood phylogenetic tree that can be updated automatically. ViCTree incorporates ViCTreeView, which is a JavaScript-based visualisation tool that enables the tree to be explored interactively in the context of pairwise distance data. Results: To demonstrate utility, ViCTree was applied to subfamily Densovirinae of family Parvoviridae. This led to the identification of six new species of insect virus. Availability: ViCTree is open-source and can be run on any Linux- or Unix-based computer or cluster. A tutorial, the documentation and the source code are available under a GPL3 license, and can be accessed at http://bioinformatics.cvr.ac.uk/victree_web/

Pre- and post- prandial appetite hormone levels in normal weight and severely obese women

<p>Abstract</p> <p>Background</p> <p>Appetite is affected by many factors including the hormones leptin, ghrelin and adiponectin. Ghrelin stimulates hunger, leptin promotes satiety, and adiponectin affects insulin response. This study was designed to test whether the pre- and postprandial response of key appetite hormones differs in normal weight (NW) and severely obese (SO) women.</p> <p>Methods</p> <p>Twenty three women ages 25–50 were recruited for this study including 10 NW (BMI = 23.1 ± 1.3 kg/m²) and 13 SO (BMI = 44.5 ± 7.1 kg/m²). The study was conducted in a hospital-based clinical research centre. Following a 12-hour fast, participants had a baseline blood draw, consumed a moderately high carbohydrate meal (60% carbohydrate, 20% protein, 20% fat) based on body weight. Postprandially, participants had six blood samples drawn at 0, 15, 30, 60, 90, and 120 minutes. Primary measures included pre- and post-prandial total ghrelin, leptin, adiponectin and insulin. A repeated measures general linear model was used to evaluate the hormone changes by group and time (significance p ≤ 0.05).</p> <p>Results</p> <p>There were significant differences between the NW and the SO for all hormones in the preprandial fasting state. The postprandial responses between the SO versus NW revealed: higher leptin (p < 0.0001), lower adiponectin (p = 0.04), trend for lower ghrelin (p = 0.06) and insulin was not different (p = 0.26). Postprandial responses over time between the SO versus NW: higher leptin (p < 0.001), lower ghrelin and adiponectin (p = 0.004, p = 0.015, respectively), and trend for higher insulin (p = 0.06).</p> <p>Conclusion</p> <p>This study indicates that significant differences in both pre- and selected post- prandial levels of leptin, ghrelin, adiponectin and insulin exist between NW and SO women. Improving our understanding of the biochemical mechanisms accounting for these differences in appetite hormones among individuals with varying body size and adiposity should aid in the development of future therapies to prevent and treat obesity.</p

Systems Theory as the Foundation for Understanding Systems

As currently used, systems theory is lacking a universally agreed upon definition. The purpose of this paper is to offer a resolution by articulating a formal definition of systems theory. This definition is presented as a unified group of specific propositions which are brought together by way of an axiom set to form a system construct: systems theory. This construct affords systems practitioners and theoreticians with a prescriptive set of axioms by which a system must operate; conversely, any set of entities identified as a system may be characterized by this set of axioms. Given its multidisciplinary theoretical foundation and discipline-agnostic framework, systems theory, as it is presented here, is posited as a general approach to understanding system behavior. © 2013 Wiley Periodicals, Inc

Accuracy of Physical Self-Description Among Chronic Exercisers and Non-Exercisers

This study addressed the role of chronic exercise to enhance physical self-description as measured by self-estimated percent body fat. Accuracy of physical self-description was determined in normal-weight, regularly exercising and non-exercising males with similar body mass index (BMI)’s and females with similar BMI’s (n=42 males and 45 females of which 23 males and 23 females met criteria to be considered chronic exercisers). Statistical analyses were conducted to determine the degree of agreement between self-estimated percent body fat and actual laboratory measurements (hydrostatic weighing). Three statistical techniques were employed: Pearson correlation coefficients, Bland and Altman plots, and regression analysis. Agreement between measured and self-estimated percent body fat was superior for males and females who exercised chronically, compared to nonexercisers. The clinical implications are as follows. Satisfaction with one’s body can be influenced by several factors, including self-perceived body composition. Dissatisfaction can contribute to maladaptive and destructive weight management behaviors. The present study suggests that regular exercise provides a basis for more positive weight management behaviors by enhancing the accuracy of self-assessed body composition