287 research outputs found
An ecological approach to the management of gulls, in particular the lesser black-backed gull Larus Fuscus (L. 1758)
A study of gull management was made at a large colony of Lesser Black-backed Gulls Ljxrus fuscus on Tambrook Fell, Lancashire. Approximately 18,000 gulls presently breed at the site, and the area utilised by the gulls extends over 6 km2 on three private estates. The main studies were conducted on the Abbeystead Estate between 1992 and 1994. The reasons for increases in the numbers of several gull species in many parts of the world during the 20th century are presented, as well as the conflicts with humans caused by these increases. The practical and moral aspects of managing gulls are evaluated, as well as the conflicts likely to result from recent increases in the urbanisation of several Larid species. The need for management strategies to incorporate up-to-date knowledge of gull demography, density dependence, breeding biology and behaviour are discussed in the light of the limited success of past attempts at managing gulls. Experiments to entirely clear specific areas of the Tambrook Fell Gullery by disturbing breeding gulls are described. The aim was to ameliorate local problems by reducing the extent of the colony using non-lethal management techniques. Disturbance was carried out in a series of 2.25ha experimental plots. Audio, visual and physical disturbance methods, presented singly or in combination, were used to investigate their ability to exclude gulls and prevent breeding. The number of gulls using the plots and the number of nests built were compared with numbers on control plots. Gulls showed habituation to all disturbance methods, although the number of gulls using a plot was reduced during disturbance and a proportion of the original number of gulls were totally excluded. Only where two disturbance methods were utilised on the same plot was breeding completely prevented. It was demonstrated that disturbance was more effective when initiated prior to the start of nest building and when conducted at the edge of the colony, and that disturbance by human presence is an effective method of preventing breeding. In the year following disturbance, only a very few gulls attempted to utilise the disturbed areas, and the need to establish a 'sink' area for birds displaced by disturbance is discussed. In two seasons, a total of 75ha were cleared of breeding gulls. This was 23% of the Abbeystead Estate and 11 % of the total gullery area. This was the first time in over thirty years of management efforts at the colony, that the extent of the gullery was successfully reduced. Models are presented to show the effects of the 1978- 1988 culls on adult survivorship and recruitment into the breeding group at Tambrook Fell. The relative effects of management strategies aimed at survivorship and productivity are discussed. A study was made to quantify the percentage of nests built by gulls at the colony that are not subsequently laid in. Behavioural differences between pairs that failed to lay eggs and pairs that successfully bred are presented. In the past, calculations of the number of breeding gulls at the colony assumed that one nest represented one pair. This was shown not to be true and a correction factor (multiplier) of 0.61 was calculated to allow counts of nests at the colony to be converted to the number of breeding pairs
Sustained expression of microRNA-155 in hematopoietic stem cells causes a myeloproliferative disorder
Mammalian microRNAs are emerging as key regulators of the development and function of the immune system. Here, we report a strong but transient induction of miR-155 in mouse bone marrow after injection of bacterial lipopolysaccharide (LPS) correlated with granulocyte/monocyte (GM) expansion. Demonstrating the sufficiency of miR-155 to drive GM expansion, enforced expression in mouse bone marrow cells caused GM proliferation in a manner reminiscent of LPS treatment. However, the miR-155–induced GM populations displayed pathological features characteristic of myeloid neoplasia. Of possible relevance to human disease, miR-155 was found to be overexpressed in the bone marrow of patients with certain subtypes of acute myeloid leukemia (AML). Furthermore, miR-155 repressed a subset of genes implicated in hematopoietic development and disease. These data implicate miR-155 as a contributor to physiological GM expansion during inflammation and to certain pathological features associated with AML, emphasizing the importance of proper miR-155 regulation in developing myeloid cells during times of inflammatory stress
Influence of diabetes on natriuretic peptide thresholds in screening for Stage B heart failure
Uncovering the Neural Signature of Lapsing Attention: Electrophysiological Signals Predict Errors up to 20 s before They Occur
The extent to which changes in brain activity can foreshadow human error is uncertain yet has important theoretical and practical implications. The present study examined the temporal dynamics of electrocortical signals preceding a lapse of sustained attention. Twenty-one participants performed a continuous temporal expectancy task, which involved continuously monitoring a stream of regularly alternating patterned stimuli to detect a rarely occurring target stimulus whose duration was 40% longer. The stimulus stream flickered at a rate of 25 Hz to elicit a steady-state visual-evoked potential (SSVEP), which served as a continuous measure of basic visual processing. Increasing activity in the band (8 –14 Hz) was found beginning20 s before a missed target. This was followed by decreases in the amplitude of two event-related components over a short pretarget time frame: the frontal P3 (3– 4 s) and contingent-negative variation (during the target interval). In contrast, SSVEP amplitude before hits and misses was closely matched, suggesting that the efficacy of ongoing basic visual processing was unaffected. Our results show that the specific neural signatures of attentional lapses are registered in the EEG up to 20 s before an error
Ischemic stroke risk, smoking, and the genetics of inflammation in a biracial population: the stroke prevention in young women study
<p>Abstract</p> <p>Background</p> <p>Although cigarette smoking is a well-established risk factor for vascular disease, the genetic mechanisms that link cigarette smoking to an increased incidence of stroke are not well understood. Genetic variations within the genes of the inflammatory pathways are thought to partially mediate this risk. Here we evaluate the association of several inflammatory gene single nucleotide polymorphisms (SNPs) with ischemic stroke risk among young women, further stratified by current cigarette smoking status.</p> <p>Methods</p> <p>A population-based case-control study of stroke among women aged 15–49 identified 224 cases of first ischemic stroke (47.3% African-American) and 211 age-comparable control subjects (43.1% African-American). Several inflammatory candidate gene SNPs chosen through literature review were genotyped in the study population and assessed for association with stroke and interaction with smoking status.</p> <p>Results</p> <p>Of the 8 SNPs (across 6 genes) analyzed, only <it>IL6 </it>SNP rs2069832 (allele C, African-American frequency = 92%, Caucasian frequency = 55%) was found to be significantly associated with stroke using an additive model, and this was only among African-Americans (age-adjusted: OR = 2.2, 95% CI = 1.0–5.0, p = 0.049; risk factor adjusted: OR = 2.5, 95% CI = 1.0–6.5, p = 0.05). When stratified by smoking status, two SNPs demonstrated statistically significant gene-environment interactions. First, the T allele (frequency = 5%) of <it>IL6 </it>SNP rs2069830 was found to be protective among non-smokers (OR = 0.30, 95% CI = 0.11–.082, p = 0.02), but not among smokers (OR = 1.63, 95% CI = 0.48–5.58, p = 0.43); genotype by smoking interaction (p = 0.036). Second, the C allele (frequency = 39%) of <it>CD14 </it>SNP rs2569190 was found to increase risk among smokers (OR = 2.05, 95% CI = 1.09–3.86, p = 0.03), but not among non-smokers (OR = 0.93, 95% CI = 0.62–1.39, p = 0.72); genotype by smoking interaction (p = 0.039).</p> <p>Conclusion</p> <p>This study demonstrates that inflammatory gene SNPs are associated with early-onset ischemic stroke among African-American women (<it>IL6</it>) and that cigarette smoking may modulate stroke risk through a gene-environment interaction (<it>IL6 and CD14</it>). Our finding replicates a prior study showing an interaction with smoking and the C allele of <it>CD14 </it>SNP rs2569190.</p
Effects of fenofibrate on renal function in patients with type 2 diabetes mellitus: the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) Study
Abstract Aims/hypothesis Fenofibrate caused an acute, sustained plasma creatinine increase in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) and Action to Control Cardiovascular Risk in Diabetes (ACCORD) studies. We assessed fenofibrate’s renal effects in a FIELD washout sub-study. Methods Type 2 diabetic patients (n=9795) aged 50 to 75 years were randomly assigned to fenofibrate (n=4895) or placebo (n=4900) for 5 years, after 6 weeks fenofibrate run-in. Albuminuria (urinary albumin:creatinine ratio) measured at baseline, year 2 and close-out) and estimated GFR, measured 4 to 6 monthly according to the Modification of Diet in Renal Disease study, were pre-specified endpoints. Plasma creatinine was re-measured 8 weeks after treatment cessation at close-out (washout sub-study, n=661). Analysis was by intention-to-treat. Results During fenofibrate run-in, plasma creatinine increased by 10.0 µmol/l (p<0.001), but quickly reversed on placebo assignment. It remained higher on fenofibrate than on placebo, but the chronic rise was slower (1.62 µmol/l vs 1.89 µmol/l annually, p=0.01), with less estimated GFR loss (1.19 vs 2.03 ml min−1 1.73 m−2 annually, p<0.001). After washout, estimated GFR had fallen less from baseline on fenofibrate (1.9 ml min−1 1.73 m−2, p=0.065) than on placebo (6.9 ml min−1 1.73 m−2, p<0.001), sparing 5.0 ml min−1 1.73 m−2 (95% CI 2.3-7.7, p<0.001). Greater preservation of estimated GFR with fenofibrate was observed during greater reduction over the active run-in period (pre-randomisation) of triacylglycerol (n=186 vs 170) and baseline hypertriacylglycerolaemia (n=89 vs 80) alone, or combined with low HDL-cholesterol (n=71 vs 60). Fenofibrate reduced urine albumin concentrations and hence albumin:creatinine ratio by 24% vs 12% (p<0.001; mean difference 14% [95% CI 9-18]; p<0.001), with 14% less progression and 18% more albuminuria regression (p<0.001) than in participants on placebo. End-stage renal event frequency was similar (n=21 vs 26, p=0.48). Conclusions/interpretation Fenofibrate reduced albuminuria and slowed estimated GFR loss over 5 years, despite initially and reversibly increasing plasma creatinine. Fenofibrate may delay albuminuria and GFR impairment in type 2 diabetes patients. Confirmatory studies are merited. Trial registration: ISRCTN64783481 Funding: The study was funded by grants from Laboratoires Fournier, Dijon, France (now part of Solvay and Abbott Pharmaceuticals) and the NHMRC of Australia.Laboratoires Fournier, Dijon, France (now part of Solvay and Abbott Pharmaceuticals
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