3,408 research outputs found

    Sex Ratio and Sexual Dimorphism in \u3ci\u3eFormica Exsectoides\u3c/i\u3e, the Allegheny Mound Ant (Hymenoptera: Formicidae)

    Get PDF
    We excavated 66 mounds from 6 populations of Formica exsectoides in Michigan jack pine, collecting sexual caste pupae for sex ratio estimates and measurement of dimorphism. Reproductive caste brood was present in only 37 ofthe 66 mounds, and presence of reproductive caste brood was associated with larger mound surface area. Females were heavier than males, but did not differ from males in energy density. Sexes did not differ in timing or rate of development. Sex ratio estimates based on individual mounds ranged from 1.0 (all male) to 0.08 (female·biased). Four of the six study populations were strongly male·biased, while sex ratio estimates for the remaining populations did not differ from equal investment. While this interpopulation variation may be caused by genetic factors, the equal investment populations were 10· cated in or near patches of clear·cut forest, suggesting that environmental impacts should be investigated

    Divergent mutational processes distinguish hypoxic and normoxic tumours.

    Get PDF
    Many primary tumours have low levels of molecular oxygen (hypoxia), and hypoxic tumours respond poorly to therapy. Pan-cancer molecular hallmarks of tumour hypoxia remain poorly understood, with limited comprehension of its associations with specific mutational processes, non-coding driver genes and evolutionary features. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2658 cancers across 38 tumour types, we quantify hypoxia in 1188 tumours spanning 27 cancer types. Elevated hypoxia associates with increased mutational load across cancer types, irrespective of underlying mutational class. The proportion of mutations attributed to several mutational signatures of unknown aetiology directly associates with the level of hypoxia, suggesting underlying mutational processes for these signatures. At the gene level, driver mutations in TP53, MYC and PTEN are enriched in hypoxic tumours, and mutations in PTEN interact with hypoxia to direct tumour evolutionary trajectories. Overall, hypoxia plays a critical role in shaping the genomic and evolutionary landscapes of cancer

    Perceptually smooth timbral guides by state-space analysis of phase-vocoder parameters

    Get PDF
    Sculptor is a phase-vocoder-based package of programs that allows users to explore timbral manipulation of sound in real time. It is the product of a research program seeking ultimately to perform gestural capture by analysis of the sound a performer makes using a conventional instrument. Since the phase-vocoder output is of high dimensionality — typically more than 1,000 channels per analysis frame—mapping phase-vocoder output to appropriate input parameters for a synthesizer is only feasible in theory

    Valuation of aircraft noise by time of day: a comparison of two approaches

    Get PDF
    This paper reports an innovative application of stated preference techniques to derive values of aircraft noise by time of day and day of week. Revealed preference techniques cannot provide such segmentations which would clearly be of use in policy development especially relating to airport operations. Given the lack of research on this issue the work reported here is highly experimental. Two stated preference experiments were designed. The first focussed on a single time period whilst the second asked respondents to trade between time periods. Both approaches yielded results that are plausible and mutually consistent in terms of relative values by time period. We conclude that stated preference techniques are particularly useful in this context where the use of aggregated values may lead to non-optimal policy decisions

    Count three for wear able computers

    Get PDF
    This paper is a postprint of a paper submitted to and accepted for publication in the Proceedings of the IEE Eurowearable 2003 Conference, and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library. A revised version of this paper was also published in Electronics Systems and Software, also subject to Institution of Engineering and Technology Copyright. The copy of record is also available at the IET Digital Library.A description of 'ubiquitous computer' is presented. Ubiquitous computers imply portable computers embedded into everyday objects, which would replace personal computers. Ubiquitous computers can be mapped into a three-tier scheme, differentiated by processor performance and flexibility of function. The power consumption of mobile devices is one of the most important design considerations. The size of a wearable system is often a design limitation

    The extended ROSAT-ESO flux-limited X-ray galaxy cluster survey (REFLEX II): V. Exploring a local underdensity in the southern sky

    Get PDF
    Several claims have been made that we are located in a locally underdense region of the Universe based on observations of supernovae and galaxy density distributions. Two recent studies of K-band galaxy surveys have, in particular, provided new support for a local underdensity in the galaxy distribution out to distances of 200-300 Mpc. If confirmed, such local underdensities would have important implications interpreting local measurements of cosmological parameters. Galaxy clusters have been shown to be ideal probes for tracing the large-scale structure of the Universe. In this paper we study the local density distribution in the southern sky with the X-ray detected galaxy clusters from the REFLEX II cluster survey. From the normalised comoving number density of clusters, we find an average underdensity of ∼30-40% in the redshift range out to z ∼ 0.04 (∼170 Mpc) in the southern extragalactic sky with a significance greater than 3.4σ. On larger scales from 300 Mpc to over 1 Gpc, the density distribution appears remarkably homogeneous. The local underdensity seems to be dominated by the south Galactic cap region. A comparison of the cluster distribution with that of galaxies in the K -band from a recent study shows that galaxies and clusters trace each other very closely in density. In the south Galactic cap region both surveys find a local underdensity in the redshift range z = 0 to 0.05 and no significant underdensity in the north Galactic cap at southern latitudes. Cosmological models that attempt to interpret the cosmic acceleration, deduced from observations of type Ia supernovae, by a large local void without the need for reacceleration, require that we are located close to the centre of a roughly spherical void with a minimum size of ∼300 Mpc. In contrast our results show that the local underdensity is not isotropic and limited to a size significantly smaller than 300 Mpc radius

    Prostate cancer

    Get PDF
    The management of prostate cancer continues to evolve rapidly, with substantial advances being made in understanding the genomic landscape and biology underpinning both primary and metastatic prostate cancer. Similarly, the emergence of more sensitive imaging methods has improved diagnostic and staging accuracy and refined surveillance strategies. These advances have introduced personalised therapeutics to clinical practice, with treatments targeting genomic alterations in DNA repair pathways now clinically validated. An important shift in the therapeutic framework for metastatic disease has taken place, with metastatic-directed therapies being evaluated for oligometastatic disease, aggressive management of the primary lesion shown to benefit patients with low-volume metastatic disease, and with several novel androgen pathway inhibitors significantly improving survival when used as a first-line therapy for metastatic disease. Research into the molecular characterisation of localised, recurrent, and progressive disease will undoubtedly have an impact on clinical management. Similarly, emerging research into novel therapeutics, such as targeted radioisotopes and immunotherapy, holds much promise for improving the lives of patients with prostate cancer

    Where are the Baryons?

    Full text link
    New, high resolution, large-scale, cosmological hydrodynamic galaxy formation simulations of a standard cold dark matter model (with a cosmological constant) are utilized to predict the distribution of baryons at the present and at moderate redshift. It is found that the average temperature of baryons is an increasing function of time, with most of the baryons at the present time having a temperature in the range 10^{5-7} K. Thus, not only is the universe dominated by dark matter, but more than one half of the normal matter is yet to be detected. Detection of this warm/hot gas poses an observational challenge, requiring sensitive EUV and X-ray satellites. Signatures include a soft, cosmic X-ray background, apparent warm components in hot clusters due to both intrinsic warm intra-cluster gas and warm inter-cluster gas projected onto clusters along the line of sight, absorption lines in X-ray and UV quasar spectra [e.g., O VI (1032,1038)A lines, OVII 574 eV line], strong emission lines (e.g., O VIII 653 eV line) and low redshift, broad, low column density \lya absorption lines. We estimate that approximately 1/4 of the extragalactic soft X-ray background (SXRB) (at 0.7 keV) arises from the warm/hot gas, half of it coming from z<0.65z<0.65 and three-quarters from z<1.00z<1.00, so the source regions should be identifiable on deep optical images.Comment: ApJ in press, revised (fig 3 is in jpg). Whole paper including fig3.ps can be obtained at "http://astro.princeton.edu/~cen/PAPERS_TO_APPEAR/64
    corecore