12,571 research outputs found
Deformed Skyrme Crystals
The Skyrme crystal, a solution of the Skyrme model, is the lowest
energy-per-charge configuration of skyrmions seen so far. Our numerical
investigations show that, as the period in various space directions is changed,
one obtains various other configurations, such as a double square wall, and
parallel vortex-like solutions. We also show that there is a sudden "phase
transition" between a Skyrme crystal and the charge 4 skyrmion with cubic
symmetry as the period is gradually increased in all three space directions.Comment: 13 pages, 6 figures. To be published in JHE
Field plate optimization in low-power high-gain source-gated transistors
Source-gated transistors (SGTs) have potentially very high output impedance and low saturation voltages, which make them ideal as building blocks for high-performance analog circuits fabricated in thin-film technologies. The quality of saturation is greatly influenced by the design of the field-relief structure incorporated into the source electrode. Starting from measurements on self-aligned polysilicon structures, we show through numerical simulations how the field plate (FP) design can be improved. A simple source FP around 1 μm long situated several tens of nanometers above the semiconductor can increase the low-voltage intrinsic gain by more than two orders of magnitude and offers adequate tolerance to process variations in a moderately scaled thin-film SGT. © 2012 IEEE
The Influence of a Goalkeeper as an Outfield Player on Defensive Subsystems in Futsal
The aim of this study was to investigate the influence of the goalkeeper as an outfield player on defensive subsystems in the team sport of futsal. For this purpose, all sequences of play involving the goalkeeper (n = 65), and the sequences without a goalkeeper (controls) (n = 11), were selected from digital video footage of a futsal competition, and analysed using TACTO software. The defensive area, attacker-defender distance, and interception distance were used to examine players’ coordination tendencies as a team in completion of successful and unsuccessful passes and shots. Results showed that each team reduced its defensive area as well as its variability in situations where the goalkeeper acted as an outfield player. This finding implies that it was an effective defensive strategy because it led to emergence of more unsuccessful passes. It was also observed that the goalkeeper acting as an outfield player was an effective strategy for attacking in terms of increasing shots at goal
Influence of Quaternary Benzophenantridine and Protopine Alkaloids on Growth Performance, Dietary Energy, Carcass Traits, Visceral Mass, and Rumen Health in Finishing Ewes under Conditions of Severe Temperature-humidity Index.
Twenty Pelibuey×Katahdin ewes (35±2.3 kg) were used to determine the effects of the consumption of standardized plant extract containing a mixture of quaternary benzophenanthridine alkaloids and protopine alkaloids (QBA+PA) on growth performance, dietary energetics, visceral mass, and ruminal epithelial health in heat-stressed ewes fed with a high-energy corn-based diet. The basal diet (13.9% crude protein and 2.09 Mcal of net energy [NE] of maintenance/kg of dry matter) contained 49.7% starch and 15.3% neutral detergent fiber. Source of QBA+PA was Sangrovit RS (SANG) which contains 3 g of quaternary benzophenathridine and protopine alkaloids per kg of product. Treatments consisted of a daily consumption of 0 or 0.5 g SANG/ewe. Ewes were grouped by weight and assigned to 10 pens (5 pens/treatment), with two ewes per pen. The experimental period lasted 70 days. The mean temperature humidity index during the course of this experiment was 81.7±1.0 (severe heat stress). There were no treatment effects on water intake. Dry matter intake was not affected (p = 0.70) by treatments, but the group fed SANG had a numerically (11.2%) higher gain in comparison to the control group, SANG improved gain efficiency (8.3%, p = 0.04), dietary NE (5.2%, p<0.01) and the observed-to-expected NE (5.9%, p<0.01). Supplemental SANG did not affect (p≥0.12) carcass characteristics, chemical composition of shoulder, and organ weights (g/kg empty body weight) of stomach complex, intestines, and heart/lung. Supplemental SANG decreased liver weight (10.3%, p = 0.02) and increased visceral fat (16.9%, p = 0.02). Rumen epithelium of ewes fed SANG had lower scores for cellular dropsical degeneration (2.08 vs 2.34, p = 0.02), parakeratosis (1.30 vs 1.82, p = 0.03) and neutrophil infiltration (2.08 vs 2.86, p = 0.05) than controls. It is concluded that SANG supplementation helped ameliorate the negative effects of severe heat on growth performance of feedlot ewes fed high-energy corn-based diets. Improvement in energetic efficiency may have been mediated, in part, by anti-inflammatory effects of supplemental SANG and corresponding enhancement of nutrient uptake
Polyvalent horse F(Ab`)2 snake antivenom: Development of process to produce polyvalent horse F(Ab`)2 antibodies anti-african snake venom
A method to obtain polyvalent anti-Bitis and polyvalent-anti-Naja antibodies was developed by immunizing horses with B. arietans, B. nasicornis, B. rhinoceros, N. melanoleuca and N. mossambicacrude venoms. Antibody production was followed by the ELISA method during the immunization procedure. Once the desired anti-venom antibody titers were attained, horses were bled and the immunoglobulins were separated from the sera by (NH4)2SO4 precipitation, cleaved with pepsin and filtered through a 30 kDa ultrafiltration membrane. F(ab´)2 fragments were further purified by Q-Fast Flow chromatography, concentrated by molecular ultrafiltration and sterilized by filtration through 0.22 m membranes. The resulting F(ab´)2 preparations were rich in intact L and in pieces of H IgG(T) chains, as demonstrated by electrophoresis and Western blot and exhibited high antibody titers, as assayed by the ELISA method. In addition, the preparations possess a significant capacity to neutralize the lethality of venoms, as estimated by ED50 determination in mouse assay and are free of toxic substances, pyrogen and bacterial or fungal contaminations
Prior Low- or High-Intensity Exercise Alters Pacing Strategy, Energy System Contribution and Performance during a 4-km Cycling Time Trial
We analyzed the influence of prior exercise designed to reduce predominantly muscle glycogen in either type I or II fibers on pacing and performance during a 4-km cycling time trial (TT). After preliminary and familiarization trials, in a randomized, repeated-measures crossover design, ten amateur cyclists performed: 1) an exercise designed to reduce glycogen of type I muscle fibers, followed by a 4-km TT (EX-FIB I); 2) an exercise designed to reduce glycogen of type II muscle fibers, followed by a 4-km TT (EX-FIB II) and; 3) a 4-km TT, without the prior exercise (CONT). the muscle-glycogen-reducing exercise in both EX-FIB I and EX-FIB II was performed in the evening, similar to 12 h before the 4-km TT. Performance time was increased and power output (PO) was reduced in EX-FIB I (432.8 +/- 8.3 s and 204.9 +/- 10.9 W) and EX-FIB II (428.7 +/- 6.7 s and 207.5 +/- 9.1 W) compared to CONT (420.8 +/- 6.4 s and 218.4 +/- 9.3 W; P0.05). the PO was lower in EX-FIB I than in CONT at the beginning and middle of the trial (P0.05). the integrated electromyography was unchanged between conditions (P>0.05). Performance may have been impaired in EX-FIB I due a more conservative pacing at the beginning and middle, which was associated with a reduced aerobic contribution. in turn, the PO profile adopted in EX-FIB II was also reduced throughout the trial, but the impairment in performance may be attributed to a reduced glycolytic contribution (i.e. reduced lactate accumulation).Foundation of Aids to Scientific Research of the State of Alagoas (FAPEAL)Univ Fed Pernambuco, CAV, Dept Phys Educ & Sports Sci, Sports Sci Res Grp, Vitoria de Santo Antao, Pernambuco, BrazilUniv São Paulo, Sch Phys Educ & Sport, Endurance Performance Res Grp, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilVictoria Univ, Coll Sport & Exercise Sci, Inst Sport Exercise & Active Living, Melbourne, Vic 8001, AustraliaUniversidade Federal de São Paulo, Dept Med, Div Nephrol, São Paulo, BrazilWeb of Scienc
Predicting the safety and efficacy of butter therapy to raise tumour pHe: an integrative modelling study
Background: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts.\ud
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Methods: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies.\ud
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Results: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1–7.2.\ud
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Conclusion: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1–7.2 is most promising
Complex network view of evolving manifolds
We study complex networks formed by triangulations and higher-dimensional
simplicial complexes representing closed evolving manifolds. In particular, for
triangulations, the set of possible transformations of these networks is
restricted by the condition that at each step, all the faces must be triangles.
Stochastic application of these operations leads to random networks with
different architectures. We perform extensive numerical simulations and explore
the geometries of growing and equilibrium complex networks generated by these
transformations and their local structural properties. This characterization
includes the Hausdorff and spectral dimensions of the resulting networks, their
degree distributions, and various structural correlations. Our results reveal a
rich zoo of architectures and geometries of these networks, some of which
appear to be small worlds while others are finite-dimensional with Hausdorff
dimension equal or higher than the original dimensionality of their simplices.
The range of spectral dimensions of the evolving triangulations turns out to be
from about 1.4 to infinity. Our models include simplicial complexes
representing manifolds with evolving topologies, for example, an h-holed torus
with a progressively growing number of holes. This evolving graph demonstrates
features of a small-world network and has a particularly heavy-tailed degree
distribution.Comment: 14 pages, 15 figure
Land use–transport interaction modeling: A review of the literature and future research directions
The aim of this review paper is to provide comprehensive and up-to-date material for both researchers and practitioners interested in land-use-transport interaction (LUTI) modeling. The paper brings together some 60 years of published research on the subject. The review discusses the dominant theoretical and conceptual propositions underpinning research in the field and the existing operational LUTI modeling frameworks as well as the modeling methodologies that have been applied over the years. On the basis of these, the paper discusses the challenges, on-going progress and future research directions around the following thematic areas: 1) the challenges imposed by disaggregation—data availability, computation time, stochastic variation and output uncertainty; 2) the challenges of and progress in integrating activity-based travel demand models into LUTI models; 3) the quest for a satisfactory measure of accessibility; and 4) progress and challenges toward integrating the environment into LUTI models
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