Divergence revealed by population crosses in the red flour beetle Tribolium castaneum

There is growing interest in the potential for population divergence (and hence speciation) to be driven by co-evolutionary arms races due to conflicts of interest between the sexes over matings and investment in offspring. It has been suggested that the signature of sexually antagonistic co-evolution may be revealed in crosses between populations through females showing the weakest response to males from their own population compared with males from other populations. The rationale behind this prediction is that females will not have been able to evolve counter-adaptations to manipulative signals from males with which they have not co-evolved. Recent theoretical treatments suggest that this prediction is not strictly exclusive to the sexual conflict theory, but it remains the case that population crosses can provide insights into the evolution of mate choice within populations. We describe crosses between six populations of the red flour beetle Tribolium castaneum. Although successful matings are no more or less likely between populations compared to within populations, females do increase their oviposition rate in response to males from other populations, relative to males from their own population. Our results are therefore consistent with the proposition that sexual conflict has driven population divergence in this species. However, we argue that the available evidence is more supportive of the hypothesis that increased female investment in response to males from other populations is a side-effect of inbreeding avoidance within populations

A Study on the Factors Influencing the Intention of Blog Usage: A Case of UUM Postgraduate Students

Nowadays, there has been a dramatic proliferation in the number of blogs and several social networks; however, little is published about what factor (s) motivates universities students to participate in blog activities. The remarkable growth and use of a social networking website such as "Facebook", "Hi5", and "Friendster" among UUM international postgraduate students is more challenging for a researcher to investigate the extent to which a new media channel affects people’s lives, relationships, and wellbeing, how and why it is used, and who is using it. Based on the Theory of Reasoned Action (TRA), a model was developed relating technology acceptance (TAM) and social influences. a combination of convenience and purposive sampling was used to collect the data from UUM Postgraduate students that used different blogs and Facebook regularly. A survey of 112 of UUM postgraduate students found strong support for the model. One of the major finding of this research illustrated that perceived usefulness, ease of use and social norms were positively related to attitude toward blogging and accounted for a higher variance. On the other hand, perceived enjoyment and attitude toward blogging did not significantly influence UUM postgraduate students’ intention to continue to use Facebook as their favorite blogging site

A mapping approach to synchronization in the "Zajfman trap". II: the observed bunch

We extend a recently introduced mapping model, which explains the bunching phenomenon in an ion beam resonator for two ions [Geyer, Tannor, J. Phys. B 37 (2004) 73], to describe the dynamics of the whole ion bunch. We calculate the time delay of the ions from a model of the bunch geometry and find that the bunch takes on a spherical form at the turning points in the electrostatic mirrors. From this condition we derive how the observed bunch length depends on the experimental parameters. We give an interpretation of the criteria for the existence of the bunch, which were derived from the experimental observations by Pedersen et al [Pedersen etal, Phys. Rev. A 65 042704].Comment: 25 pages, 6 figures; added new section 5 and clarified text; submitted to J. Phys.

Optimization of Passive and Hybrid Mode-locked Figure Eight Laser

In pulsed fiber laser using Q-switching or mode locking techniques, the choice of the different components and the management of linear and non linear parameters of the cavity, play a paramount role in the generation of stable ultra short pulses with high peak powers and low widths. In this paper, we focus on the operating process of mode locked fiber lasers especially passively and hybrid type Eight Fiber Lasers (8FLs). By modeling the light propagation within the two cavities, we describe the whole operating process of ultra short pulses generation. The interaction between the mode locking mechanism and nonlinear effects in fiber laser is also illustrated. We demonstrate enhancing non linear effects do not lead necessarily to better results. It depends on the type of mode locking techniques used. The highest and narrowest output pulses are obtained for specific values of the non linear parameters and the mean dispersion of the cavity

Perceived health and quality of life: the effect of exposure to atmospheric pollution

International audienc

Modeling and experimental verification of single event upsets

The research performed and the results obtained at the Laboratory for Radiation Studies, Prairie View A&M University and Texas A&I University, on the problem of Single Events Upsets, the various schemes employed to limit them and the effects they have on the reliability and fault tolerance at the systems level, such as robotic systems are reviewed

Evolving Role for Pharmacotherapy in NAFLD/NASH

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent, dynamic disease that occurs across the age spectrum and can lead to cirrhosis and hepatocellular carcinoma. There are currently no US Food and Drug Administration (FDA) approved treatments for NAFLD; however, this is a field of active research. This review summarizes emerging pharmacotherapies for the treatment of adult and pediatric NAFLD. Investigated pharmacotherapies predominantly target bile acid signaling, insulin resistance, and lipid handling within the liver. Three drugs have gone on to phase III trials for which results are available. Of those, obeticholic acid is the single agent that demonstrates promise according to the interim analyses of the REGENERATE trial. Obeticholic acid showed reduction of fibrosis in adults with nonalcoholic steatohepatitis (NASH) taking 25 mg daily for 18 months (n = 931, reduction in fibrosis in 25% vs. 12% placebo, P \u3c 0.01). Ongoing phase III trials include REGENERATE and MAESTRO-NASH, which investigates thyroid hormone receptor-β agonist MGL-3196. Outcomes of promising phase II trials in adults with NASH are also available and those have investigated agents, including the fibroblast growth factor (FGF)19 analogue NGM282, the GLP1 agonist liraglutide, the FGF21 analogue Pegbelfermin, the sodium glucose co-transporter 2 inhibitor Empagliflozin, the ketohexokinase inhibitor PF-06835919, the acetyl-coenzyme A carboxylase inhibitor GS-0976, and the chemokine receptor antagonist Cenicriviroc. Completed and ongoing clinical trials emphasize the need for a more nuanced understanding of the phenotypes of subgroups within NAFLD that may respond to an individualized approach to pharmacotherapy