175 resultados para POOR GLOBULAR-CLUSTER
Resumo:
The Eurasian otter (Lutra lutra L.) is a top predator in aquatic systems and plays an important role in ecosystem functioning. However, it has undergone dramatic declines throughout Europe as a result of environmental degradation. We examine the putative role of the otter as a bioindicator in Ireland which remains a stronghold for the species and affords a unique opportunity to examine variation in its ecological niche. We describe diet, using spraint contents, along rivers during 2010 and conduct a review and quantitative meta-analysis of the results of a further 21 studies. We aimed to assess variation in otter diet in relation to river productivity, a proxy for natural nutrification and anthropogenic eutrophication, and availability of salmonid prey (Salmo trutta and Salmo salar), to test the hypothesis that otter diet is related to environmental quality. Otter diet did not vary with levels of productivity or availability of salmonids whilst Compositional Analysis suggested there was no selection of salmonid over non-salmonid fish. There was a distinct niche separation between riverine and lacustrine systems, the latter being dominated by Atlantic eel (Anguilla anguilla). Otters are opportunistic and may take insects, freshwater mussels, birds, mammals and even fruit. Otters living along coasts have a greatest niche breath than those in freshwater systems which encompasses a wide variety of intertidal prey though pelagic fish are rarely taken. It is concluded that the ability of the otter to feed on a wide diversity of prey taxa and the strong influence of habitat type, renders it a poor bioindicator of environmental water quality. It seems likely that the plasticity of the habitat and dietary niche of otters, and the extent of suitable habitat, may have sustained populations in Ireland despite intensification of agriculture during the 20th century.
Resumo:
We report on our discovery and observations of the Pan-STARRS1 supernova (SN) PS1-12sk, a transient with properties that indicate atypical star formation in its host galaxy cluster or pose a challenge to popular progenitor system models for this class of explosion. The optical spectra of PS1-12sk classify it as a Type Ibn SN (c.f. SN 2006jc), dominated by intermediate-width (3x10^3 km/s) and time variable He I emission. Our multi-wavelength monitoring establishes the rise time dt = 9-23 days and shows an NUV-NIR SED with temperature > 17x10^3 K and a peak rise magnitude of Mz = -18.9 mag. SN Ibn spectroscopic properties are commonly interpreted as the signature of a massive star (17 - 100 M_sun) explosion within a He-enriched circumstellar medium. However, unlike previous Type Ibn supernovae, PS1-12sk is associated with an elliptical brightest cluster galaxy, CGCG 208-042 (z = 0.054) in cluster RXC J0844.9+4258. The expected probability of an event like PS1-12sk in such environments is low given the measured infrequency of core-collapse SNe in red sequence galaxies compounded by the low volumetric rate of SN Ibn. Furthermore, we find no evidence of star formation at the explosion site to sensitive limits (Sigma Halpha
Resumo:
Purpose: Despite the use of 5-fluorouracil (5-FU)–based adjuvant treatments, a large proportion of patients with high-risk stage II/III colorectal cancer will relapse. Thus, novel therapeutic strategies are needed for early-stage colorectal cancer. Residual micrometastatic disease from the primary tumor is a major cause of patient relapse.
Experimental Design: To model colorectal cancer tumor cell invasion/metastasis, we have generated invasive (KRASMT/KRASWT/+chr3/p53-null) colorectal cancer cell subpopulations. Receptor tyrosine kinase (RTK) screens were used to identify novel proteins that underpin the migratory/invasive phenotype. Migration/invasion was assessed using the XCELLigence system. Tumors from patients with early-stage colorectal cancer (N = 336) were examined for AXL expression.
Results: Invasive colorectal cancer cell subpopulations showed a transition from an epithelial-to-mesenchymal like phenotype with significant increases in migration, invasion, colony-forming ability, and an attenuation of EGF receptor (EGFR)/HER2 autocrine signaling. RTK arrays showed significant increases in AXL levels in all invasive sublines. Importantly, 5-FU treatment resulted in significantly increased migration and invasion, and targeting AXL using pharmacologic inhibition or RNA interference (RNAi) approaches suppressed basal and 5-FU–induced migration and invasion. Significantly, high AXL mRNA and protein expression were found to be associated with poor overall survival in early-stage colorectal cancer tissues.
Conclusions: We have identified AXL as a poor prognostic marker and important mediator of cell migration/invasiveness in colorectal cancer. These findings provide support for the further investigation of AXL as a novel prognostic biomarker and therapeutic target in colorectal cancer, in particular in the adjuvant disease in which EGFR/VEGF–targeted therapies have failed.
Resumo:
Regulation of ABCB1 (P-glycoprotein/Pgp) in AML was investigated. In a historical cohort with Pgp and transcriptional regulator expression profiling data available (n=141), FOXO1 correlated with Pgp protein expression. This was confirmed in an independent cohort (n=204). Down-regulation (siRNA) or hyperactivation (nicotinamide) of FOXO1 led to corresponding changes in Pgp. Low FOXO1 expression correlated with FLT3-ITDs (p
Resumo:
Despite the significant burden of cervical cancer, Malaysia like many middle-income countries relies on opportunistic cervical screening as opposed to a more organized population-based program. The aim of this study was to ascertain the effectiveness of a worksite screening initiative upon Papanicolaou smear test (Pap test) uptake among educated working women in Malaysia.
Resumo:
Purpose – The purpose of this paper is to evaluate the effectiveness of a free book gifting programme, called “Bookstart+”, in improving family reading outcomes.
Design/methodology/approach – Bookstart+ consists of a pack of books and reading materials provided to families at their two-year-old child's statutory health visit. The pack is accompanied by a short priming demonstration, delivered by the health visitor, on shared reading. The evaluation took the form of a randomised controlled trial (RCT) with 460 families from the client lists of 115 health visitors.
Findings – The study found evidence of: a positive significant effect on parents’ attitudes to reading and books (Cohen's d=+0.192, p=0.034); no significant effect on parental attitudes to their child reading (d=+0.085, p=0.279); and a negative effect, approaching significance, on public library usage (d=-0.160, p=0.055).
Research limitations/implications – The attrition rate was high, with only 43.9 per cent of the target families completing all of the research. However, this level of attrition did not lead to any significant differences between the control and intervention groups on their pre-test measures.
Practical implications – The study provides recommendations for free book gifting service provision in relation to pack contents and delivery.
Originality/value – This paper contributes to the limited international RCT evidence on free book gifting programmes.
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In the twentieth century, the Irish-born population in England has typically been in worse health than both the native population and the Irish population in Ireland, a reversal of the commonly observed healthy migrant effect. Recent birth cohorts living in England and born in Ireland, however, are healthier than the English population. The substantial Irish migrant health penalty arises principally for cohorts born between 1920 and 1960. In this article, we attempt to understand the processes that generated these changing migrant health patterns for Irish migrants to England. Our results suggest a strong role for economic selection in driving the dynamics of health differences between Irish-born migrants and white English populations.
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In this paper, the impact of multiple active eavesdroppers on cooperative single carrier systems with multiple relays and multiple destinations is examined. To achieve the secrecy diversity gains in the form of opportunistic selection, a two-stage scheme is proposed for joint relay and destination selection, in which, after the selection of the relay with the minimum effective maximum signal-to-noise ratio (SNR) to a cluster of eavesdroppers, the destination that has the maximum SNR from the chosen relay is selected. In order to accurately assess the secrecy performance, the exact and asymptotic expressions are obtained in closed-form for several security metrics including the secrecy outage probability, the probability of non-zero secrecy rate, and the ergodic secrecy rate in frequency selective fading. Based on the asymptotic analysis, key design parameters such as secrecy diversity gain, secrecy array gain, secrecy multiplexing gain, and power cost are characterized, from which new insights are drawn. Moreover, it is concluded that secrecy performance limits occur when the average received power at the eavesdropper is proportional to the counterpart at the destination. Specifically, for the secrecy outage probability, it is confirmed that the secrecy diversity gain collapses to zero with outage floor, whereas for the ergodic secrecy rate, it is confirmed confirm that its slope collapses to zero with capacity ceiling.
Resumo:
Low-energy electron-impact hydrogen loss due to dissociative electron attachment (DEA) to the uracil and thymine molecules in a water cluster environment is investigated theoretically. Only the A'-resonance contribution, describing the near-threshold behavior of DEA, is incorporated. Calculations are based on the nonlocal complex potential theory and the multiple scattering theory, and are performed for a model target with basic properties of uracil and thymine, surrounded by five water molecules. The DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster. This growth is due to two effects: the increase of the resonance lifetime and the negative shift in the resonance position due to interaction of the intermediate negative ion with the surrounding water molecules. A similar effect was earlier found in DEA to chlorofluorocarbons.
Resumo:
This article examines hospital provision in Ireland during the early twentieth century. It examines attempts by the newly independent Irish Free State to reform and de-stigmatise medical relief in former workhouse infirmaries. Such reforms were designed to move away from nineteenth century welfare regimes which were underpinned by principles of deterrence. The reform initiated in independent Ireland - the first attempted break-up of the New Poor Law in Great Britain or Ireland - was partly successful. Many of the newly named County and District Hospitals provided solely for medical cases and managed to dissociate such health care provision from the relief of poverty. However, some hospitals continued to act as multifunctional institutions and provided for various categories including the sick, the aged and infirm, 'unmarried mothers' and 'harmless lunatics'. Such institutions often remained associated with the relief of poverty. This article also examines patient fee-payment and outlines how fresh terms of entitlement and means-testing were established. Such developments were even more pronounced in voluntary hospitals where the majority of patients made a financial contribution to their treatment. The article argues that the ability to pay at times determined the type of provision, either voluntary or rate-aided, available to the sick. However, it concludes that the clinical condition of patients often determined whether they entered a more prestigious voluntary hospital or the former workhouse. Although this article concentrates on two Irish case studies, County Kerry and Cork City; it is conceptualised within wider developments with particular reference to the British context.