Evaporation of a packet of quantized vorticity

A recent experiment has confirmed the existence of quantized turbulence in superfluid He3-B and suggested that turbulence is inhomogenous and spreads away from the region around the vibrating wire where it is created. To interpret the experiment we study numerically the diffusion of a packet of quantized vortex lines which is initially confined inside a small region of space. We find that reconnections fragment the packet into a gas of small vortex loops which fly away. We determine the time scale of the process and find that it is in order of magnitude agreement with the experiment.Comment: figure 1a,b,c and d, figure2, figure

Evaluation of the CNS and cardiovascular effects of prolonged exposure to bromotrifluromethane (CBrF3)

The proposed use of bromotrifluoromethane (CBrF3) as a fire extinguishant in aircraft, spacecraft and submarines has stimulated increasing interest and research in the toxicological properties of this compound. In a spacecraft, because of its unique recirculating life support system, the introduction of CBrF3 by leakage or intentional discharge, will result in continuous exposure of crewman to low concentrations of this compound for periods of up to 7 days, or possibly even longer. The effects of low concentrations of CBrF3, under continuous exposure conditions, on the CNS and cardiovascular systems of animals to enable an assessment of these risks were investigated

A cannabigerol-rich Cannabis sativa extract, devoid of ∆9-tetrahydrocannabinol, elicits hyperphagia in rats

Objective: Non-psychoactive phytocannabinoids (pCBs) from Cannabis sativa may represent novel therapeutic options for cachexia due to their pleiotropic pharmacological activities, including appetite stimulation. We have recently shown that purified cannabigerol (CBG) is a novel appetite stimulant in rats. As standardised extracts from Cannabis chemotypes dominant in one pCB (botanical drug substances (BDS)) often show greater efficacy and/or potency than purified pCBs, we investigated the effects of a CBG-rich BDS, devoid of psychoactive ∆9-THC, on feeding behaviour. Methods: Following a 2 hour pre-feed satiation procedure, 16 male Lister-hooded rats were administered CBG-BDS (at 30-240 mg/kg) or vehicle. Food intake, meal pattern microstructure and locomotor activity were recorded over 2 hours. Results: Total food intake was increased by 120 and 240mg/kg CBG-BDS vs vehicle (1.53g and 1.36g, respectively, vs 0.56g; p<0.05 and p<0.01). Latency to feeding onset was dose-dependently decreased by all doses (p<0.05-0.01), and 120 and 240mg/kg doses increased both the number of meals consumed (p<0.01) and cumulative size of the first 2 meals (p<0.05 and p<.0.01). No significant effect was observed on ambulatory activity or rearing behaviour. Conclusions: CBG-BDS is a novel appetite stimulant, which may have greater potency than purified CBG, despite the absence of ∆9-THC in the extract

Specific heat of the Kelvin modes in low temperature superfluid turbulence

It is pointed out that the specific heat of helical vortex line excitations, in low temperature superfluid turbulence experiments carried out in helium II, can be of the same order as the specific heat of the phononic quasiparticles. The ratio of Kelvin mode and phonon specific heats scales with L_0 T^{-5/2}, where L_0 represents the smoothed line length per volume within the vortex tangle, such that the contribution of the vortex mode specific heat should be observable for L_0 = 10^6-10^8 cm^{-2}, and at temperatures which are of order 1-10 mK.Comment: 3 pages, 1 figur

Atomic Structure and Dynamics of Single Platinum Atom Interactions with Monolayer MoS

We have studied atomic level interactions between single Pt atoms and the surface of monolayer MoS₂ using aberration-corrected annular dark field scanning transmission electron microscopy at an accelerating voltage of 60 kV. Strong contrast from single Pt atoms on the atomically resolved monolayer MoS₂ lattice enables their exact position to be determined with respect to the MoS₂ lattice, revealing stable binding sites. In regions of MoS₂ free from surface contamination, the Pt atoms are localized in S vacancy sites and exhibit dynamic hopping to nearby vacancy sites driven by the energy supplied by the electron beam. However, in areas of MoS₂ contaminated with carbon surface layers, the Pt atoms appear at various positions with respect to the underlying MoS₂ lattice, including on top of Mo and in off-axis positions. These variations are due to the Pt bonding with the surrounding amorphous carbon layer, which disrupts the intrinsic Pt-MoS₂ interactions, leading to more varied positions. Density functional theory (DFT) calculations reveal that Pt atoms on the surface of MoS₂ have a small barrier for migration and are stabilized when bound to either a single or double sulfur vacancies. DFT calculations have been used to understand how the catalytic activity of the MoS₂ basal plane for hydrogen evolution reaction is influenced by Pt dopants by variation of the hydrogen adsorption free energy. This strong dependence of catalytic effect on interfacial configurations is shown to be common for a series of dopants, which may provide a means to create and optimize reaction centers

Avaliação do desempenho de fungos entomopatogênicos sobre fêmeas de Dactylopius opuntiae (Hemiptera: dactylopiidae) em condições de laboratório.

O OBJETIVO DESTE TRABALHO FOI INVESTIGAR O POTENCIAL DOS FUNGOS ENTOMOPATOGÊNICOS NO CONTROLE DE D. OPUNTIAE.Resumo 1669-1

The Role of Personality on Persuasion to Exercise: Does Conscientiousness and Extraversion Moderate the Constructs of the Theory of Planned Behavior?

The Theory of Planned Behavior (TPB) is a leading theoretical model used to explain the intention-behavior relationship as it relates to exercise. Even though TPB consistently explains some of the variance between intention and behavior, the rest of the variance has yet to be explained. This study investigates whether individual differences in terms of the Big Five personality dimensions, specifically, Conscientiousness and Extraversion, can account for any of the additional variance. The present research extends on past research by examining how personality relates to intention in terms of its relation to the constructs of TPB. 122 students at Union college participated in the experiment in which they were asked to complete personality inventories and read a persuasive message to exercise targeted at one of the constructs of the TPB: attitude towards the act, perceived behavioral control (PBC), or subjective norm (SN). It was hypothesized that for individuals high in conscientiousness the message targeted at PBC would produce greater intention to exercise whereas for individuals high in the extraversion dimension, messages targeted at both attitude towards the act and SN would predict greater intentions. Results support the first hypothesis, that individuals high in conscientiousness had a greater intention to exercise after the PBC message. In the second hypothesis, only SN was related to greater intentions. Implications concerning public health implementations to increase exercise are discussed

Pre-pregnancy predictors of hypertension in pregnancy among Aboriginal and Torres Strait Islander women in north Queensland, Australia; a prospective cohort study

BACKGROUND Compared to other Australian women, Indigenous women are frequently at greater risk for hypertensive disorders of pregnancy. We examined pre-pregnancy factors that may predict hypertension in pregnancy in a cohort of Aboriginal and Torres Strait Islander women in north Queensland. METHODS Data on a cohort of 1009 Indigenous women of childbearing age (15–44 years) who participated in a 1998–2000 health screening program in north Queensland were combined with 1998–2008 Queensland hospitalisations data using probabilistic data linkage. Data on the women in the cohort who were hospitalised for birth (n = 220) were further combined with Queensland perinatal data which identified those diagnosed with hypertension in pregnancy. RESULTS Of 220 women who gave birth, 22 had hypertension in the pregnancy after their health check. The mean age of women with and without hypertension was similar (23.7 years and 23.9 years respectively) however Aboriginal women were more affected compared to Torres Strait Islanders. Pre-pregnancy adiposity and elevated blood pressure at the health screening program were predictors of a pregnancy affected by hypertension. After adjusting for age and ethnicity, each 1 cm increase in waist circumference showed a 4% increased risk for hypertension in pregnancy (PR 1.04; 95% CI; 1.02-1.06); each 1 point increase in BMI showed a 9% adjusted increase in risk (1.09; 1.04-1.14). For each 1 mmHg increase in baseline systolic blood pressure there was an age and ethnicity adjusted 6% increase in risk and each 1 mmHg increase in diastolic blood pressure showed a 7% increase in risk (1.06; 1.03-1.09 and 1.07; 1.03-1.11 respectively). Among those free of diabetes at baseline, the presence of the metabolic syndrome (International Diabetes Federation criteria) predicted over a three-fold increase in age-ethnicity-adjusted risk (3.5; 1.50-8.17). CONCLUSIONS Pre-pregnancy adiposity and features of the metabolic syndrome among these young Aboriginal and Torres Strait Islander women track strongly to increased risk of hypertension in pregnancy with associated risks to the health of babies.Sandra K Campbell, John Lynch, Adrian Esterman and Robyn McDermot

Optothermal nonlinearity of silica aerogel

The authors acknowledge support from EPSRC (EP/J004200/1), the Templeton Foundation (grant number 58277) and the ERC project VANGUARD (grant number 664782).We report on the characterization of silica aerogel thermal optical nonlinearity, obtained by z-scan technique. The results show that typical Silica Aerogels have nonlinear optical coefficient similar to that of glass (≃ 10-12m2/W), with negligible optical nonlinear absorption. The nonlinear coefficient can be increased to values in the range of 10-10m2/W by embedding an absorbing dye in the Aerogel. This value is one order of magnitude higher than that observed in the pure dye and in typical highly nonlinear materials like liquid crystals.PostprintPeer reviewe