1,488 research outputs found

    Ancestral bias in the Hras1 gene and distal Chromosome 7 among inbred mice

    Get PDF
    Inbred strains of mice vary in their frequency of liver tumors initiated by a mutation in the Hras1 (H-ras) proto-oncogene. We sequenced 4.5 kb of the Hras1 gene on distal Chr 7 in a diverse set of 12 commonly used laboratory inbred strains of mice and detected no sequence variation to account for strain-specific differences in Hras1 mutation prevalence. Furthermore, the Hras1 sequence is essentially monoallelic for an ancestral gene derived from the M. m. domesticus species. To determine if the monoallelism and associated low rate of polymorphism are unique to Hras1 or representative of the general chromosomal locale, we extended the sequence analysis to 12 genes in the final 8 Mb of distal Chr 7. A region of at least 2.5 Mb that encompasses several genes, including Hras1 and the H19/Igf2 loci, demonstrates virtually no sequence variation. The 12 inbred strains share one dominant haplotype derived from the M. m. domesticus allele. Chromosomal regions flanking the monoallelic segment exhibit a significantly higher rate of variation and multiple haplotypes, a majority of which are attributed to M. m. domesticus or M. m. musculus ancestry

    Microclimate variables of the ambient environment deliver the actual estimates of the extrinsic incubation period of Plasmodium vivax and Plasmodium falciparum : A study from a malaria-endemic urban setting, Chennai in India

    Get PDF
    Background: Environmental factors such as temperature, relative humidity and their daily variation influence a range of mosquito life history traits and hence, malaria transmission. The standard way of characterizing environmental factors with meteorological station data need not be the actual microclimates experienced by mosquitoes within local transmission settings. Methods: A year-long study was conducted in Chennai, India to characterize local temperature and relative humidity (RH). Data loggers (Hobos) were placed in a range of probable indoor and outdoor resting sites of Anopheles stephensi. Recordings were taken hourly to estimate mean temperature and RH, together with daily temperature range (DTR) and daily relative humidity range. The temperature data were used to explore the predicted variation in extrinsic incubation period (EIP) of Plasmodium falciparum and Plasmodium vivax between microhabitats and across the year. Results: Mean daily temperatures within the indoor settings were significantly warmer than those recorded outdoors. DTR in indoor environments was observed to be modest and ranged from 2 to 6 °C. Differences in EIP between microhabitats were most notable during the hottest summer months of April-June, with parasite development predicted to be impaired for tiled houses and overhead tanks. Overall, the prevailing warm and stable conditions suggest rapid parasite development rate regardless of where mosquitoes might rest. Taking account of seasonal and local environmental variation, the predicted EIP of P. falciparum varied from a minimum of 9.1 days to a maximum of 15.3 days, while the EIP of P. vivax varied from 8.0 to 24.3 days. Conclusions: This study provides a detailed picture of the actual microclimates experienced by mosquitoes in an urban slum malaria setting. The data indicate differences between microhabitats that could impact mosquito and parasite life history traits. The predicted effects for EIP are often relatively subtle, but variation between minimum and maximum EIPs can play a role in disease transmission, depending on the time of year and where mosquitoes rest. Appropriate characterization of the local microclimate conditions would be the key to fully understand the effects of environment on local transmission ecology

    Comparison of pain, cortisol levels, and psychological distress in women undergoing surgical termination of pregnancy under local anaesthesia versus intravenous sedation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The weight of evidence suggests that women who freely choose to terminate a pregnancy are unlikely to experience significant mental health risks, however some studies have documented psychological distress in the form of posttraumatic stress disorder and depression in the aftermath of termination. Choice of anaesthetic has been suggested as a determinant of outcome. This study compared the effects of local anaesthesia and intravenous sedation, administered for elective surgical termination, on outcomes of pain, cortisol, and psychological distress.</p> <p>Methods</p> <p>155 women were recruited from a private abortion clinic and state hospital (mean age: 25.4 ± 6.1 years) and assessed on various symptom domains, using both clinician-administered interviews and self-report measures just prior to termination, immediately post-procedure, and at 1 month and 3 months post-procedure. Morning salivary cortisol assays were collected prior to anaesthesia and termination.</p> <p>Results</p> <p>The group who received local anaesthetic demonstrated higher baseline cortisol levels (mean = 4.7 vs 0.2), more dissociative symptoms immediately post-termination (mean = 14.7 vs 7.3), and higher levels of pain before (mean = 4.9 vs 3.0) and during the procedure (mean = 8.0 vs 4.4). However, in the longer-term (1 and 3 months), there were no significant differences in pain, psychological outcomes (PTSD, depression, self-esteem, state anxiety), or disability between the groups. More than 65% of the variance in PTSD symptoms at 3 months could be explained by baseline PTSD symptom severity and disability, and post-termination dissociative symptoms. Of interest was the finding that pre-procedural cortisol levels were positively correlated with PTSD symptoms at both 1 and 3 months.</p> <p>Conclusion</p> <p>High rates of PTSD characterise women who have undergone surgical abortions (almost one fifth of the sample meet criteria for PTSD), with women who receive local anaesthetic experiencing more severe acute reactions. The choice of anesthetic, however, does not appear to impact on longer-term psychiatric outcomes or functional status.</p

    A Radial Velocity Study of the Planetary System of pi Mensae: Improved Planet Parameters for pi Mensae c and a Third Planet on a 125 Day Orbit

    Get PDF
    π Men hosts a transiting planet detected by the Transiting Exoplanet Survey Satellite space mission and an outer planet in a 5.7 yr orbit discovered by radial velocity (RV) surveys. We studied this system using new RV measurements taken with the HARPS spectrograph on ESO's 3.6 m telescope, as well as archival data. We constrain the stellar RV semiamplitude due to the transiting planet, π Men c, as Kc = 1.21 ± 0.12 m s^{−1}, resulting in a planet mass of M_{c} = 3.63 ± 0.38 M_{⊕}. A planet radius of R_{c} = 2.145 ± 0.015 R_{⊕} yields a bulk density of ρc = 2.03 ± 0.22 g cm^{−3}. The precisely determined density of this planet and the brightness of the host star make π Men c an excellent laboratory for internal structure and atmospheric characterization studies. Our HARPS RV measurements also reveal compelling evidence for a third body, π Men d, with a minimum mass M_{d} sin i_{d} = 13.38 ± 1.35 M_{⊕} orbiting with a period of Porb,d = 125 days on an eccentric orbit (e_{d} = 0.22). A simple dynamical analysis indicates that the orbit of π Men d is stable on timescales of at least 20 Myr. Given the mutual inclination between the outer gaseous giant and the inner rocky planet and the presence of a third body at 125 days, π Men is an important planetary system for dynamical and formation studies

    Testing for an effect of a mindfulness induction on child executive functions

    Get PDF
    Several sessions of mindfulness practice can exert positive gains for child executive functions (EF); however, the evidence for effects of a mindfulness induction, on EF for adults, is mixed and this effect has not been tested in children. The immediate effect of an age appropriate 3-min mindfulness induction on EF of children aged 4–7 years was tested. Participants (N = 156) were randomly assigned to a mindfulness induction or dot-to-dot activity comparison group before completing four measures of EF. A composite score for EF was calculated from summed z scores of the four EF measures. A difference at baseline in behavioural difficulties between the mindfulness induction and comparison group meant that data was analysed using a hierarchical regression. The mindfulness induction resulted in higher average performance for the composite EF score (M = 0.12) compared to the comparison group (M = − 0.05). Behavioural difficulties significantly predicted 5.3% of the variance in EF performance but participation in the mindfulness or comparison induction did not significantly affect EF. The non-significant effect of a mindfulness induction to exert immediate effects on EF fits within broader evidence reporting mixed effects when similar experimental designs have been used with adults. The findings are discussed with consideration of the extent to which methodological differences may account for these mixed effects and how mindfulness inductions fit within broader theoretical and empirical understanding of the effects of mindfulness on EF

    Search for rare quark-annihilation decays, B --> Ds(*) Phi

    Full text link
    We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

    Get PDF
    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Genome-wide DNA methylation levels and altered cortisol stress reactivity following childhood trauma in humans

    Get PDF
    DNA methylation likely plays a role in the regulation of human stress reactivity. Here we show that in a genome-wide analysis of blood DNA methylation in 85 healthy individuals, a locus in the Kit ligand gene (KITLG; cg27512205) showed the strongest association with cortisol stress reactivity (P=5.8 � 10?6). Replication was obtained in two independent samples using either blood (N=45, P=0.001) or buccal cells (N=255, P=0.004). KITLG methylation strongly mediates the relationship between childhood trauma and cortisol stress reactivity in the discovery sample (32% mediation). Its genomic location, a CpG island shore within an H3K27ac enhancer mark, and the correlation between methylation in the blood and prefrontal cortex provide further evidence that KITLG methylation is functionally relevant for the programming of stress reactivity in the human brain. Our results extend preclinical evidence for epigenetic regulation of stress reactivity to humans and provide leads to enhance our understanding of the neurobiological pathways underlying stress vulnerability
    corecore