947 resultados para Drake, Francis, approximately 1540-1596.


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We compared the quantity of wheat bait consumed by Norway rats (Rattus norvegicus) from: (i) wooden bait trays, made as safe as possible from non-target animals using materials available at trial sites, and (ii) three different, proprietary tamper-resistant rat bait boxes. A balanced Latin square experimental design was used to overcome operational biases that occur when baits of different types are applied simultaneously at the same sites. The consumption of bait from the four different types of bait placement differed significantly and accounted for more than 76% of the total variation. The amount of bait eaten by rats from the bait trays was approximately eight times greater than the quantity eaten from the tamper-resistant bait boxes. The three bait box designs appeared to deter bait consumption by rats to a similar extent. Tamper-resistant bait boxes are essential tools in the application of rodenticides in many circumstances but their use should not be mandatory when it is possible to make baits safe from non-target animals by other means.

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Drake Passage is the narrowest constriction of the Antarctic Circumpolar Current (ACC) in the Southern Ocean, with implications for global ocean circulation and climate. We review the long-term sustained monitoring programmes that have been conducted at Drake Passage, dating back to the early part of the twentieth century. Attention is drawn to numerous breakthroughs that have been made from these programmes, including (a) the first determinations of the complex ACC structure and early quantifications of its transport; (b) realization that the ACC transport is remarkably steady over interannual and longer periods, and a growing understanding of the processes responsible for this; (c) recognition of the role of coupled climate modes in dictating the horizontal transport, and the role of anthropogenic processes in this; (d) understanding of mechanisms driving changes in both the upper and lower limbs of the Southern Ocean overturning circulation, and their impacts. It is argued that monitoring of this passage remains a high priority for oceanographic and climate research, but that strategic improvements could be made concerning how this is conducted. In particular, long-term programmes should concentrate on delivering quantifications of key variables of direct relevance to large-scale environmental issues: in this context, the time-varying overturning circulation is, if anything, even more compelling a target than the ACC flow. Further, there is a need for better international resource-sharing, and improved spatio-temporal coordination of the measurements. If achieved, the improvements in understanding of important climatic issues deriving from Drake Passage monitoring can be sustained into the future.

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The relationship between income and nutrient intake is explored. Nonparametric, panel, and quantile regressions are used. Engle curves for calories, fat, and protein are approximately linear in logs with carbohydrate intakes exhibiting diminishing elasticities as incomes increase. Elasticities range from 0.10 to 0.25, with fat having the highest elasticities. Countries in higher quantiles have lower elasticities than those in lower quantiles. Results predict significant cumulative increases in calorie consumption which are increasingly composed of fats. Though policies aimed at poverty alleviation and economic growth may assuage hunger and malnutrition, they may also exacerbate problems associated with obesity.

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We examine the characteristics of the sixth merger wave that started in 2003 and came to an end approximately in late 2007. The drivers of this wave lie primarily in the availability of abundant liquidity, in line with neoclassical explanations of merger waves. Acquirers were less overvalued relative to targets, and merger proposals comprised higher cash elements. Moreover, the market for corporate control was less competitive, acquirers were less acquisitive, managers displayed less over-optimism and offers involved significantly lower premiums, indicating more cautious and rational acquisition decisions. Strikingly, however, deals destroyed at least as much value for acquiring shareholders as in the 1990s.

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The English cleric Matthew Sutcliffe arguably produced the first comprehensive security concept in history. It had at its centre the war between England and Spain (1585-1604), and Sutcliffe advocated taking the war to the Iberian Peninsula to seize Philip II's main Atlantic ports, rather than remaining satisfied with the indirect combat of Spain in Flanders, defensive action against naval attacks on England and the guerre de course on Spanish shipping at sea. This approach seems to be at the heart of Essex's 1596 naval campaing against Spanish ports, which foundered on the bureaucratic politics of the Elizabethan government.

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Information on the breeding biology of the White-headed Vulture Trigonoceps occipitalis is limited and published data are few. Within the Kruger National Park in north-east South Africa there is a regionally important population of about 60 White-headed Vulture pairs, of which 22 pairs were monitored for five years between 2008 and 2012 to determine key aspects of their breeding biology. Across 73 pair/years the mean productivity of 55 breeding attempts was 0.69 chicks per pair. Median egg-laying date across all of the Kruger National Park was 27 June, but northern nests were approximately 30 d later than southern nests. Mean (SD) nearest-neighbour distance was 9 976  7 965 m and inter-nest distances ranged from 1 400 m to more than 20 km, but this did not differ significantly between habitat types. Breeding productivity did not differ significantly between habitat types. The results presented here are the first for this species in Kruger National Park and provide details against which future comparisons can be made.

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Filamin A (FlnA) cross-links actin filaments and connects the Von Willebrand factor receptor GPIb-IX-V to the underlying cytoskeleton in platelets. Because FlnA deficiency is embryonic lethal, mice lacking FlnA in platelets were generated by breeding FlnA(loxP/loxP) females with GATA1-Cre males. FlnA(loxP/y) GATA1-Cre males have a macrothrombocytopenia and increased tail bleeding times. FlnA-null platelets have decreased expression and altered surface distribution of GPIbalpha because they lack the normal cytoskeletal linkage of GPIbalpha to underlying actin filaments. This results in approximately 70% less platelet coverage on collagen-coated surfaces at shear rates of 1,500/s, compared with wild-type platelets. Unexpectedly, however, immunoreceptor tyrosine-based activation motif (ITAM)- and ITAM-like-mediated signals are severely compromised in FlnA-null platelets. FlnA-null platelets fail to spread and have decreased alpha-granule secretion, integrin alphaIIbbeta3 activation, and protein tyrosine phosphorylation, particularly that of the protein tyrosine kinase Syk and phospholipase C-gamma2, in response to stimulation through the collagen receptor GPVI and the C-type lectin-like receptor 2. This signaling defect was traced to the loss of a novel FlnA-Syk interaction, as Syk binds to FlnA at immunoglobulin-like repeat 5. Our findings reveal that the interaction between FlnA and Syk regulates ITAM- and ITAM-like-containing receptor signaling and platelet function.

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Within the phenomenon of entrepreneurship, the extant literature suggests that the normative actor is embodied by and through stereotypical masculinized characteristics. In this paper,we contextualize entrepreneurship as self-employment in order to explore how such stereotypical characterizations might influence women’s attitudes toward this activity. However, rather than analyzing the confirmatory effects of stereotypes, we critically evaluate the effect of counterstereotypical characterizations upon women’s propensity for self-employment. Drawing upon life-span data, we explore whether self-employed mothers disconfirm masculinized stereotypes and so act as positive role models for their daughters.As hypothesized, we found that maternal self-employment has a counterstereotypical effect and so positively influences daughters to become self-employed. These data indicate, however, that this effect is tempered by personal stereotypes held by daughters; moreover, it is shaped by significant life events (marriage, parenthood, education, and prior managerial experience). By using a robust data set, this paper contributes to our understanding of how stereotypes and role expectations influence women’s propensity toward entrepreneurial activity.

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This study analyses the influence of vegetation structure (i.e. leaf area index and canopy cover) and seasonal background changes on moderate-resolution imaging spectrometer (MODIS)-simulated reflectance data in open woodland. Approximately monthly spectral reflectance and transmittance field measurements (May 2011 to October 2013) of cork oak tree leaves (Quercus suber) and of the herbaceous understorey were recorded in the region of Ribatejo, Portugal. The geometric-optical and radiative transfer (GORT) model was used to simulate MODIS response (red, near-infrared) and to calculate vegetation indices, investigating their response to changes in the structure of the overstorey vegetation and to seasonal changes in the understorey using scenarios corresponding to contrasting phenological status (dry season vs. wet season). The performance of normalized difference vegetation index (NDVI), soil-adjusted vegetation index (SAVI), and enhanced vegetation index (EVI) is discussed. Results showed that SAVI and EVI were very sensitive to the emergence of background vegetation in the wet season compared to NDVI and that shading effects lead to an opposing trend in the vegetation indices. The information provided by this research can be useful to improve our understanding of the temporal dynamic of vegetation, monitored by vegetation indices.