Effects of single and mixed infections with wild type and genetically modified Helicoverpa armigera nucleopolyhedrovirus on movement behaviour of cotton bollworm larvae

Naturally occurring insect viruses can modify the behaviour of infected insects and thereby modulate virus transmission. Modifications of the virus genome could alter these behavioural effects. We studied the distance moved and the position of virus-killed cadavers of fourth instars of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) infected with a wild-type genotype of H. armigera nucleopolyhedrovirus (HaSNPV) or with one of two recombinant genotypes of this virus on cotton plants. The behavioural effects of virus infection were examined both in larvae infected with a single virus genotype, and in larvae challenged with mixtures of the wild-type and one of the recombinant viruses. An egt-negative virus variant caused more rapid death and lower virus yield in fourth instars, but egt-deletion did not produce consistent behavioural effects over three experiments, two under controlled glasshouse conditions and one in field cages. A recombinant virus containing the AaIT-(Androctonus australis Hector) insect-selective toxin gene, which expresses a neurotoxin derived from a scorpion, caused faster death and cadavers were found lower down the plant than insects infected with unmodified virus. Larvae that died from mixed infections of the AaIT-expressing recombinant and the wild-type virus died at positions significantly lower, compared to infection with the pure wild-type viral strain. The results indicate that transmission of egt-negative variants of HaSNPV are likely to be affected by lower virus yield, but not by behavioural effects of egt gene deletion. By contrast, the AaIT recombinant will produce lower virus yields as well as modified behaviour, which together can contribute to reduced virus transmission under field conditions. In addition, larvae infected with both the wild-type virus and the toxin recombinant behaved as larvae infected with the toxin recombinant only, which might be a positive factor for the risk assessment of such toxin recombinants in the environment

Harmonic oscillators in the Nos\'e - Hoover thermostat

We study the dynamics of an ensemble of non-interacting harmonic oscillators in a nonlinear dissipative environment described by the Nos\'e - Hoover model. Using numerical simulation we find the histogram for total energy, which agrees with the analysis of the Nos\'e - Hoover equations effected with the method of averaging. The histogram does not correspond to Gibbs' canonical distribution. We have found oscillations at frequency proportional to $\sqrt{\alpha/m}$, $\alpha$ the dissipative parameter of thermostat and $m$ the characteristic mass of particle, about the stationary state corresponding to equilibrium. The oscillations could have an important bearing upon the analysis of simulating molecular dynamics in the Nos\'e - Hoover thermostat.Comment: 7 pages, 4 figure

Evaluation of techniques for removal of spacecraft contaminants from activated carbon

Alternative techniques for the regeneration of carbon contaminated with various spacecraft contaminants were evaluated. Four different modes of regeneration were evaluated: (1) thermal desorption via vacuum, (2) thermal desorption via nitrogen purge, (3) in-situ catalytic oxidation of adsorbed contaminants, and (4) in-situ non-catalytic oxidation of adsorbed contaminants

Plastic deformations in crystal, polycrystal, and glass in binary mixtures under shear: Collective yielding

Using molecular dynamics simulation, we examine the dynamics of crystal, polycrystal, and glass in a Lennard-Jones binary mixture composed of small and large particles in two dimensions. The crossovers occur among these states as the composition c is varied at fixed size ratio. Shear is applied to a system of 9000 particles in contact with moving boundary layers composed of 1800 particles. The particle configurations are visualized with a sixfold orientation angle alpha_j(t) and a disorder variable D_j(t) defined for particle j, where the latter represents the deviation from hexagonal order. Fundamental plastic elements are classified into dislocation gliding and grain boundary sliding. At any c, large-scale yielding events occur on the acoustic time scale. Moreover, they multiply occur in narrow fragile areas, forming shear bands. The dynamics of plastic flow is highly hierarchical with a wide range of time scales for slow shearing. We also clarify the relationship between the shear stress averaged in the bulk region and the wall stress applied at the boundaries.Comment: 17 pages, 15 figures, to appear in Physical Review

Lyapunov instability for a periodic Lorentz gas thermostated by deterministic scattering

In recent work a deterministic and time-reversible boundary thermostat called thermostating by deterministic scattering has been introduced for the periodic Lorentz gas [Phys. Rev. Lett. {\bf 84}, 4268 (2000)]. Here we assess the nonlinear properties of this new dynamical system by numerically calculating its Lyapunov exponents. Based on a revised method for computing Lyapunov exponents, which employs periodic orthonormalization with a constraint, we present results for the Lyapunov exponents and related quantities in equilibrium and nonequilibrium. Finally, we check whether we obtain the same relations between quantities characterizing the microscopic chaotic dynamics and quantities characterizing macroscopic transport as obtained for conventional deterministic and time-reversible bulk thermostats.Comment: 18 pages (revtex), 7 figures (postscript

THE EFFECTS OF STATIC STRETCHING ON MEASURES OF GROSS MOTOR COORDINATION DURING VIGOROUS CYCLING

The purpose of this study was to assess the effects of static stretching on gross motor coordination patterns (GMCP) exhibited during vigorous cycling. The performance of 29 females between the ages of eighteen and thirty were analyzed during the Wingate Anaerobic Test (WAnT). The participants completed the test under two conditions, following static stretching and no stretching. Results showed statistically significant differences (p = 0.05) between conditions for dependent variables assessed throughout this common 30 second test of maximal cycling. These findings suggest that static stretching subtly influenced GMCP exhibited during the WAnT

Does the Friel Anaerobic Threshold Test Accurately Detect Heart Rate Deflection in Trained Cyclists?

The Friel Anaerobic Threshold Test (FATT) has been used to determine anaerobic threshold (AT). The FATT suggests AT occurs near the heart rate deflection point (HRDP) at a rating of perceived exertion (RPE) of 17. Purpose: The primary purpose of this study was to determine 1) whether the HRDP could be determined using the FATT, 2) examine differences between HRVT and HR that coincided Borg’s rating of perceived exertion (RPE) of 17, and 3) if riding position (hoods or aero) would influence performance. Methods: Fourteen male cyclists (30.4 ± 7.41years of age; 151.8 ± 60.4 cycled miles/week) participated in the study. Each subject performed the FATT on two occasions within one week. Results: The findings of this study suggest that the FATT can determine HRDP in trained cyclists while riding in the hoods position but not the aero position. No significant difference was found between the hoods and aero position for HRVT as measured by the metabolic cart. Our data suggest that HR at an RPE of 15 more accurately reflects the HRVT than the RPE of 17. A low, non-significant correlation was found for both the hoods and aero (0.41 and 0.44, respectively; p \u3e 0.20) for the HR at RPE of 17. Conclusion: The findings of this study suggest that the FATT can determine HRDP in trained cyclists. However, HRDP was identified in the cyclists preferred riding position. When performing the FATT, HRVT at an RPE of 15 should be used to estimate VT over the suggested RPE of 17

STATIC STRETCHING DOES NOT AFFECT MEASURES OF POWER AND FATIGUE DURING VIGOROUS CYCLING AMONG WOMEN

Static stretching has been linked to lesser performance in many sport activities. The purpose of this study was to determine the impact of static stretching upon power and fatigue performance measures during vigorous cycling. In this study, vigorous cycling was assessed using the Wingate Anaerobic Test (WAnT). Using a counterbalanced design, twenty nine female participants completed standardized static stretching and nonstretching protocols prior to completing the WAnT. No statistically-significant differences (p = 0.05) were found between conditions for measures of peak power (PP), low power (LP) or fatigue index (FI). These findings suggest that static stretching had no statistically-significant effect on these performance measures commonly assessed during the WAnT

Mood and Performance Anxiety in High School Basketball Players: A Pilot Study

International Journal of Exercise Science 10(4): 604-618, 2017. Participation in competitive sport may impact psychological measures, such as mood and performance anxiety, which in turn may impact enjoyment, adherence, continued participation, and so on. This study assessed the feasibility – in terms of process, resources, management, and potential scientific value– of measuring the effect of varying competitive challenges upon the mood and performance anxiety measures of high school athletes. The participants (n=12) consisted of the boys’ varsity basketball team at a high school in a rural Midwestern community. Participants completed the Profile of Mood States (POMS) to assess mood and the Sport Anxiety Scale-2 (SAS-2) to assess performance anxiety, respectively. Survey administration occurred at baseline and prior to games designated as non-conference, conference, and state tournament. A-priori feasibility measures were achieved in this prospective design. Significant correlations on the subscale measures were found on the POMS and SAS-2 administered before the four conditions in this study; Chronbach’s alpha ranged from 0.54- 0.94 across conditions for POMS subscales, and Chronbach’s alpha ranged from 0.73-0.97 across all conditions for SAS-2 subscales, respectively. Significant differences were found across conditions in the POMS subscale confusion [F(3,33) = 5.71, p = 0.01] and in the SAS-2 subscale worry [F(3,33) = 6.13, p=0.01]. These preliminary findings suggest that the competitive conditions in this study significantly affected some measures of mood and performance anxiety in high school basketball players. These findings warrant further investigation, as well as suggest coaches could gather such information from their players, ultimately aiding in player development and team performance