Protracted rainfall decreases temperature within leatherback turtle (Dermochelys coriacea) clutches in Grenada, West Indies: Ecological implications for a species displaying temperature dependent sex determination

Protracted or intense rainfall may affect the reproductive success of reptilian species on a number of levels ranging from the availability of prey, the integrity of the nesting site and the subsequent survivability of offspring. For sea turtles (a species displaying temperature sex determination) nesting throughout the tropics and subtropics, rainfall has previously been shown to influence the development environment of clutches; in its extreme resulting in high levels of egg or hatchling mortality. Yet when compared to other abiotic variables affecting clutch success, rainfall has received relatively little attention. We therefore examined how fluctuations in local rainfall at a tropical nesting site for leatherback turtles (Dermochelys coriacea) affected the nest environment. Temperature data loggers placed within clutches (n = 8) revealed that protracted rainfall had a marked cooling effect on nests, so that seasonally improbable male-producing temperatures (

Thermal conditions in nests of loggerhead turtles: further evidence suggesting female skewed sex ratios of hatchling production in the Mediterranean

Temperature was recorded in 23 nests of the loggerhead turtle (Caretta caretta) and control sites of nest depth at Alagadi (35 degrees 33'N, 33 degrees 47'E), Northern Cyprus, eastern Mediterranean. Control site sand temperature was found to be highly correlated with mean daily air temperature and mean nest temperature. Mean temperature in nests ranged from 29.5 degreesC to 33.2 degreesC, with mean temperature in the middle third of incubation ranging from 29.3 degreesC to 33.7 degreesC. Hatching success was significantly correlated with incubation temperature, with nests experiencing very high temperatures exhibiting low hatching success. All nests demonstrated regular diel variation in temperature with mean daily fluctuations ranging from 0.3 degreesC to 1.4 degreesC. Increase in temperature above that of the prevailing sand temperature attributed to metabolic heating was clearly demonstrated in 14 of 15 clutches, with the mean level of metabolic heating of all nests being 0.4 degreesC. However, the level of metabolic heating varied markedly throughout the incubation period with levels being significantly higher in the final third of incubation. Incubation duration was found to be significantly correlated to both the mean temperature of nests throughout the incubation period and during the middle third of incubation. The relationship between incubation duration and mean incubation temperature was used to estimate mean incubation temperatures at most major nesting sites throughout the Mediterranean from available data on incubation durations, showing that mean incubation temperature is likely to be above 29.0 degreesC at most sites in most seasons. (C) 2001 Elsevier Science B.V. All rights reserved.

Sex differences in fetal habituation

There is some evidence for sex differences in habituation in the human fetus, but it is unknown whether this is due to differences in central processing (habituation) or in more peripheral processes, sensory or motor, involved in the response. This study examined whether the sex of the fetus influenced auditory habituation at 33weeks of gestation, and whether this was due to differences in habituation or in the sensory or motor components using a set of four experiments. The first experiment found that female fetuses required significantly fewer stimulus presentations to habituate than males. The second experiment revealed no difference in the spontaneous motor behaviour of male and female fetuses. The third experiment examined auditory intensity thresholds for the stimuli used to habituate the fetus. No differences in thresholds were found between males and females, although there was inter-individual variability in thresholds. A final experiment, using stimuli individualized for that particular fetus' auditory intensity threshold, found that female fetuses habituated faster than males. In combination, the studies reveal that habituation in the human fetus is affected by sex and this is due to a difference in central 'information processing' of the stimuli rather than peripheral aspects of the response. It is argued that male and female fetuses present different neurobehavioural developmental trajectories, with females more advanced at 33weeks than males. This study suggests that research examining prenatal behaviour should consider the factor of fetal sex. This may be particularly pertinent where there is an intention to use the results diagnostically. © 2012 Blackwell Publishing Ltd.

Hepatitis A outbreak predominantly affecting men who have sex with men in Northern Ireland, October 2008 to July 2009

We describe an outbreak of hepatitis A which evolved in Northern Ireland between October 2008 and July 2009, against a background of large concurrent hepatitis A outbreaks in various parts of Europe. Thirty-eight cases were defined as outbreak cases using a stratified case definition; 36 were males with a median age of 29 years and of the 28 males whose sexual orientation was known, 26 were men who have sex with men (MSM). Detailed descriptive epidemiology data collected through standardised questionnaires, together with sequencing of a 289 bp fragment of the VP1/2PA region of the virus, significantly aided the understanding of the spread of the outbreak when non-MSM cases occurred. The sequence of the outbreak strain, genotype IA, was indistinguishable from that involved in a large outbreak in the Czech Republic. Although seeded in a generally susceptible Northern Ireland population, the outbreak remained mostly contained in MSM, showing this sub-population to be the most vulnerable despite ongoing hepatitis A vaccination programmes in genito-urinary medicine clinics.

Managing SMT Resource Usage through Speculative Instruction Window Weighting

Simultaneous multithreading processors dynamically share processor resources between multiple threads. In general, shared SMT resources may be managed explicitly, for instance, by dynamically setting queue occupation bounds for each thread as in the DCRA and Hill-Climbing policies. Alternatively, resources may be managed implicitly; that is, resource usage is controlled by placing the desired instruction mix in the resources. In this case, the main resource management tool is the instruction fetch policy which must predict the behavior of each thread (branch mispredictions, long-latency loads, etc.) as it fetches instructions.