2,145 research outputs found

    Investigating CXOU J163802.6-471358: a new pulsar wind nebula in the Norma region?

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    We present the first analysis of the extended source CXOU J163802.6--471358, which was discovered serendipitously during the {\em Chandra} X-ray survey of the Norma region of the Galactic spiral arms. The X-ray source exhibits a cometary appearance with a point source and an extended tail region. The complete source spectrum is fitted well with an absorbed power law model and jointly fitting the {\em Chandra} spectrum of the full source with one obtained from an archived {\em XMM-Newton} observation results in best fit parameters NHN_{\rm H} =1.50.5+0.7×1023cm2=1.5^{+0.7}_{-0.5}\times10^{23} \text{cm}{^{-2}} and Γ=1.10.6+0.7\Gamma=1.1^{+0.7}_{-0.6} (90% confidence uncertainties). The unabsorbed luminosity of the full source is then LX4.8×1033d102L_X\sim 4.8\times10^{33}d_{10}^2ergs s1^{-1} with d10=d/10d_{10}=d/10kpc, where a distance of 10 kpc is a lower bound inferred from the large column density. The radio counterpart found for the source using data from the Molonglo Galactic Plane Survey epoch-2 (MGPS-2) shows an elongated tail offset from the X-ray emission. No infrared counterpart was found. The results are consistent with the source being a previously unknown pulsar driving a bow shock through the ambient medium

    Analysis of the Vibration Spectrum Based on the Input Voltage Spectrum

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    Joint Effect of Multiple Prothrombotic Genotypes and Mean Platelet Volume on the Risk of Incident Venous Thromboembolism

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    Background - A high mean platelet volume (MPV), a marker of increased platelet reactivity, is a risk factor for venous thromboembolism (VTE). Whether established prothrombotic single nucleotide polymorphisms (SNPs) further increase the VTE risk in subjects with high MPV because of biological interaction remains unknown. Aim - To investigate the joint effect of high MPV and prothrombotic genotypes, comprising a 5-SNP genetic risk score (GRS), on the risk of VTE in a population-based case–cohort. Methods - Incident VTE cases (n = 653) and a subcohort (n = 1,774) were derived from the Tromsø Study (1994–2012). DNA was genotyped for rs8176719 (ABO), rs6025 (F5), rs1799963 (F2), rs2036914 (F11), and rs2066865 (FGG). Hazard ratios (HRs) for VTE with 95% confidence intervals (CIs) were estimated according to predefined MPV-strata ( Results - The combination of high MPV and risk alleles, either as individual SNPs or the GRS, had an additive effect on VTE risk. Compared with subjects with MPV Conclusion - The combination of high MPV and prothrombotic genotypes had an additive effect on VTE risk, suggesting there is no biological interaction between these risk factors in the pathogenesis of VTE

    A New Link in a Chain of Genres?

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    Institutional genres often form dynamic systems or chains. In this paper we report on a possible expansion of the genre system that undergirds the appointment process of assistant professors in the U.S. This expansion consists of a “response letter” to a letter of recommendation. We first analyse a small corpus of these response letters by looking at the openings and closings and the bodies of the letters. The larger aim of this analysis is to explore the possible rationales that might underlie the composition, stylistic character and content of these texts

    Coarse-grained simulation of transmembrane peptides in the gel phase

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    We use Dissipative Particle Dynamics simulations, combined with parallel tempering and umbrella sampling, to investigate the potential of mean force between model transmembrane peptides in the various phases of a lipid bilayer, including the low-temperature gel phase. The observed oscillations in the effective interaction between peptides are consistent with the different structures of the surrounding lipid phases

    Single nucleotide polymorphisms in the HIF-1α gene and chemoradiotherapy of locally advanced rectal cancer

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    The aim of this study was to investigate the predictive impact of polymorphisms in the HIF-1α gene on the response to chemoradiotherapy (CRT) in rectal cancer. This study included two cohorts of patients with locally advanced rectal cancer receiving long-course CRT. The HIF-1α C1772T (rs11549465), G1790A (rs11549467) and c(*)191T>C (rs2057482) polymorphisms were investigated in the test cohort (n=65), and HIF-1α c(*)191T>C was analysed in the validation cohort (n=198). No correlations were identified between the polymorphisms and clinicopathological factors. The HIF-1α C1772T and HIF-1α G1790A polymorphisms demonstrated no correlation with tumour response to CRT in the test cohort. The HIF-1α c(*)191T>C CC genotype was marginally associated with a higher rate of complete tumour response (P=0.05) in the test cohort, while the HIF-1α c(*)191T>C CC genotype was associated with a poor tumour response (P=0.03) in the validation cohort. In conclusion, these results suggest that HIF-1α polymorphisms have no value as predictors of response to neoadjuvant CRT in rectal cancer. The results of the HIF-1α c(*)191T>C in two cohorts differ and emphasise the importance of biomarker validation

    Træer i svinefolde

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    Producer svinekød og træbiomasse på samme areal

    Auditory opportunity and visual constraint enabled the evolution of echolocation in bats

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    Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar
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