936 resultados para confluence of powers


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The discussion on the New Philology triggered by French and North American scholars in the last decade of the 20th century emphasized the material character of textual transmission inside and outside the written evidences of medieval manuscripts by downgrading the active role of the historical author. However, the reception of the ideas propagated by the New Philology adherents was rather divided. Some researchers questioned its innovative status (K. Stackmann: “Neue Philologie?”), others saw a new era of the “powers of philology” evoked (H.-U. Gumbrecht). Besides the debates on the New Philology another concept of textual materiality strengthened in the last decade, maintaining that textual alterations somewhat relate to biogenetic mutations. In a matter of fact, phenomena such as genetic and textual variation, gene recombination and ‘contamination’ (the mixing of different exemplars in one manuscript text) share common features. The paper discusses to what extent the biogenetic concepts can be used for evaluating manifestations of textual production (as the approach of ‘critique génétique’ does) and of textual transmission (as the phylogenetic analysis of manuscript variation does). In this context yet the genealogical concept of stemmatology – the treelike representation of textual development abhorred by the New Philology adepts – might prove to be useful for describing the history of texts. The textual material to be analyzed will be drawn from the Parzival Project, which is currently preparing a new electronic edition of Wolfram von Eschenbach’s Parzival novel written shortly after 1200 and transmitted in numerous manuscripts up to the age of printing (www.parzival.unibe.ch). Researches of the project have actually resulted in suggesting that the advanced knowledge of the manuscript transmission yields a more precise idea on the author’s own writing process.

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Starting of from Avner Offer’s comment that the First World War was not only a war of steel and gold, but also of bread and potatoes (1989: 1) and my own research on British as well as Australian preparations for economic warfare and based on sources from the entente as well as the central powers but also from the United States, Canada and Australia, may presentation will focus on the interdependence of the measures taken by entente as well as central power authorities in the second half of 1916. Already a year before both sides had become aware that this war would not only be decided on the battlefield, but that the issues of primary as well as secondary resources would be decisive. Accordingly measures that could strike the enemy in this field were discussed and put into place more and more and this at time, when weather conditions caused a reduction of harvest all over Europe, Northern America and Argentina.

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An evolutionary model of human behavior should privilege emotions: essential, phylogenetically ancient behaviors that learning and decision making only subserve. Infants and non-mammals lack advanced cognitive powers but still survive. Decision making is only a means to emotional ends, which organize and prioritize behavior. The emotion of pride/shame, or dominance striving, bridges the social and biological sciences via internalization of cultural norms.

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Alexander's Dictum--"to be is to have causal powers"--appears to furnish an argument against the reality of familiar medium-sized objects. For every time a familiar object appears to cause a familiar macro-event, it sets up a rival claim by its component microparticles to have caused the complex swarm of microphysical events that composes into that macro-event. But this argument, argues this paper, wrongly assumes that even after familiar objects are removed from the picture, there is a phenomenon of joint causation which unites all and only the microparticles within each familiar object.

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Recent studies on the history of economic development demonstrate that concentration of power on a monarch or a ruling coalition impedes economic growth and that institutional changes that diffuse power, though beneficial to the society in general, are opposed by some social groups. In November 2005, Kenyans rejected a proposed constitution primarily because it did not reduce the powers of the executive to any significant degree. Using data of voting patterns in the constitutional referendum and following the rational choice framework, I estimate a model of the demand for power diffusion and demonstrate that groups voting decisions depend on expected gains and likelihood of monopolizing power. The results also reveal the importance of ethnic divisions in hindering the power diffusion process, and therefore the study establishes a channel through which ethnic fragmentation impacts on economic development.

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Recent studies of the linkages between the wealth of nations and the institutions of governance suggest that concentrating political power in a monarchy or a ruling coalition impedes economic growth and, moreover, that while power-diffusing reforms can enhance the wellbeing of society in general, opposition by groups benefitting from the status quo is predictable. In November 2005, Kenyans rejected a proposed constitution that, despite promises made by their new chief executive, would not have lessened the powers of the presidency. Using a unique, constituency-level dataset on the referendum vote, we estimate a model of the demand for power diffusion and find that ethnic groups' voting decisions are influenced by their expected gains and losses from constitutional change. The results also highlights the importance of ethnic divisions in hindering the power-diffusion process, and thus establish a channel through which ethnic fragmentation adversely impacts economic development.

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Sizes and power of selected two-sample tests of the equality of survival distributions are compared by simulation for small samples from unequally, randomly-censored exponential distributions. The tests investigated include parametric tests (F, Score, Likelihood, Asymptotic), logrank tests (Mantel, Peto-Peto), and Wilcoxon-Type tests (Gehan, Prentice). Equal sized samples, n = 18, 16, 32 with 1000 (size) and 500 (power) simulation trials, are compared for 16 combinations of the censoring proportions 0%, 20%, 40%, and 60%. For n = 8 and 16, the Asymptotic, Peto-Peto, and Wilcoxon tests perform at nominal 5% size expectations, but the F, Score and Mantel tests exceeded 5% size confidence limits for 1/3 of the censoring combinations. For n = 32, all tests showed proper size, with the Peto-Peto test most conservative in the presence of unequal censoring. Powers of all tests are compared for exponential hazard ratios of 1.4 and 2.0. There is little difference in power characteristics of the tests within the classes of tests considered. The Mantel test showed 90% to 95% power efficiency relative to parametric tests. Wilcoxon-type tests have the lowest relative power but are robust to differential censoring patterns. A modified Peto-Peto test shows power comparable to the Mantel test. For n = 32, a specific Weibull-exponential comparison of crossing survival curves suggests that the relative powers of logrank and Wilcoxon-type tests are dependent on the scale parameter of the Weibull distribution. Wilcoxon-type tests appear more powerful than logrank tests in the case of late-crossing and less powerful for early-crossing survival curves. Guidelines for the appropriate selection of two-sample tests are given. ^

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With rates of obesity and overweight continuing to increase in the US, the attention of public health researchers has focused on nutrition and physical activity behaviors. However, attempts to explain the disparate rates of obesity and overweight between whites and Hispanics have often proven inadequate. Indeed, the nebulous term ‘ethnicity’ provides little important detail in addressing potential biological, behavioral, and environmental factors that may affect rates of obesity and overweight. In response to this, the present research seeks to test the explanatory powers of ethnicity by situating the nutrition and physical activity behaviors of whites and Hispanic into their broader social contexts. It is hypothesized that a student's gender and grade level, as well as the socioeconomic status and ethnic composition of their school, will have more predictive power for these behaviors than will self-reported ethnicity. ^ Analyses revealed that while ethnicity did not seem to impact nutrition behaviors among the wealthier schools and those with fewer Hispanics, ethnicity was relevant in explaining these behaviors in the poorest tertile of schools and those with the highest number of Hispanics. With respect to physical activity behaviors, the results were mixed. The variables representing regular physical activity, participation in extracurricular physical activities, and performance of strengthening and toning exercises were more likely to be determined by SES and ethnic composition than ethnicity, especially among 8th grade males. However, school sports team and physical education participation continued to vary by ethnicity, even after controlling for SES and ethnic composition of schools. In conclusion then, it is important to understand the intersecting demographic and social variables that define and surround the individual in order to understand nutrition and physical activity behaviors and thus overweight and obesity.^

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The determination of size as well as power of a test is a vital part of a Clinical Trial Design. This research focuses on the simulation of clinical trial data with time-to-event as the primary outcome. It investigates the impact of different recruitment patterns, and time dependent hazard structures on size and power of the log-rank test. A non-homogeneous Poisson process is used to simulate entry times according to the different accrual patterns. A Weibull distribution is employed to simulate survival times according to the different hazard structures. The current study utilizes simulation methods to evaluate the effect of different recruitment patterns on size and power estimates of the log-rank test. The size of the log-rank test is estimated by simulating survival times with identical hazard rates between the treatment and the control arm of the study resulting in a hazard ratio of one. Powers of the log-rank test at specific values of hazard ratio (≠1) are estimated by simulating survival times with different, but proportional hazard rates for the two arms of the study. Different shapes (constant, decreasing, or increasing) of the hazard function of the Weibull distribution are also considered to assess the effect of hazard structure on the size and power of the log-rank test. ^

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An interim analysis is usually applied in later phase II or phase III trials to find convincing evidence of a significant treatment difference that may lead to trial termination at an earlier point than planned at the beginning. This can result in the saving of patient resources and shortening of drug development and approval time. In addition, ethics and economics are also the reasons to stop a trial earlier. In clinical trials of eyes, ears, knees, arms, kidneys, lungs, and other clustered treatments, data may include distribution-free random variables with matched and unmatched subjects in one study. It is important to properly include both subjects in the interim and the final analyses so that the maximum efficiency of statistical and clinical inferences can be obtained at different stages of the trials. So far, no publication has applied a statistical method for distribution-free data with matched and unmatched subjects in the interim analysis of clinical trials. In this simulation study, the hybrid statistic was used to estimate the empirical powers and the empirical type I errors among the simulated datasets with different sample sizes, different effect sizes, different correlation coefficients for matched pairs, and different data distributions, respectively, in the interim and final analysis with 4 different group sequential methods. Empirical powers and empirical type I errors were also compared to those estimated by using the meta-analysis t-test among the same simulated datasets. Results from this simulation study show that, compared to the meta-analysis t-test commonly used for data with normally distributed observations, the hybrid statistic has a greater power for data observed from normally, log-normally, and multinomially distributed random variables with matched and unmatched subjects and with outliers. Powers rose with the increase in sample size, effect size, and correlation coefficient for the matched pairs. In addition, lower type I errors were observed estimated by using the hybrid statistic, which indicates that this test is also conservative for data with outliers in the interim analysis of clinical trials.^

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This paper reports the results of the investigations of 2006-2007 on the distribution and migration forms of artificial radionuclides and chemical elements in the Ob-Irtysh water system. Three regions were studied. One of them is a local segment of the Ob River upstream from the confluence with the Irtysh River; its investigation allowed us to estimate the general radioecological state of the aquatic environment affected by the activity of the Tomsk 7 plant. The second region is a local segment of the Irtysh River upstream from its confluence with the Ob River, where the influence of emissions from the NPO Mayak could be estimated. The third region is the water area of the Ob River after its confluence with the Irtysh River. It characterizes the real level of radioactive and chemical contamination of the middle reaches of the Ob River. In order to explain horizontal variations in the distribution of radionuclides in the upper layer of bottom sediments collected at various sites, the results of sorption-kinetic experiments with radioactive tracers in the precipitate-solution system were used. The investigation of the migration forms of trace elements and radionuclides occurring in river water was based on the method of tangential-flow membrane filtration. Chemical element contents were determined in 400-ml water samples. A set of Millipore polysulfone membranes with pore sizes of 8, 1.2, 0.45, 0.1, and 0.025 µm was employed. Taking into account the ultralow specific concentrations of radionuclides in the water, they were analyzed in 300-500 litre samples using Millipore polysulfone membranes with pore sizes of 0.45 µm and 15 kDa. This allowed us to estimate the percentages of cesium-137 and plutonium-239, 240 in the suspended particulate fraction, colloids, and dissolved species.

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High resolution stratigraphy based on oxygen isotope ratios of the planktonic foraminifers Neogloboquadrina dutertrei (d'Orbigny), Globigeriniodes ruber (d'Orbigny), and Globigerina bulloides (d'Orbigny), magnetic susceptibility, and calcium carbonate content covers the sedimentary record of ODP Hole 728A drilled on the Oman Margin from approximately 10 k.y. to 525 k.y., comprising isotopic stages 1-13. Below stage 13 isotopic stage boundaries cannot be defined with certainty in our data. Sediment accumulation rates were calculated from the isotopic record of N. dutertrei by matching it with the age model SPECMAP curve. During the glacial periods sediment accumulation rates were higher than during the interglacial periods, reflecting increased input from the shelf during low-stands of sea level and increased eolian input. Periodograms for the past 524 k.y. on oxygen isotope records of N. dutertrei, G. ruber, and G. bulloides, on calcium carbonate content, magnetic susceptibility, and on a foraminiferal fragmentation record show powers matching the Milankovitch periodicities. High powers are concentrated around 103 k.y. In the spectra of oxygen isotope ratios of N. dutertrei, magnetic susceptibility, and foraminiferal fragmentation these are significant at the 80% confidence level with respect to a first order autoregressive model. Power concentrations near 43 k.y., matching obliquity, are present but subdued in all spectra. Power concentrations near 23 k.y., matching precession, are significant in the spectra of the oxygen isotope record of N. dutertrei, magnetic susceptibility, and calcium carbonate content record. Fragmentation of planktonic foraminifers increased during the interglacial periods. This is attributed to dissolution of the tests in an expanded oxygen minimum zone (OMZ), where undersaturation of calcium carbonate is caused by enhanced production in the euphotic zone, which would suggest stronger monsoonal induced upwelling during interglacial periods. Extension of the OMZ could also be increased by outflow of low oxygen marginal basin bottom water.

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Fresh deposits above the margins of Reedy Glacier show that maximum ice levels during the last glaciation were several hundred meters above present near the glacier mouth and converged to less than 60 m above the present-day surface at the head of the glacier. Exposure ages of samples from five sites along its margin show that Reedy Glacier and its tributaries thickened asynchronously between 17 and 7 kyr BP At the Quartz Hills, located midway along the glacier, maximum ice levels were reached during the period 17-14 kyr BP. Farther up-glacier the ice surface reached its maximum elevation more recently: 14.7-10.2 kyr BP at the Caloplaca Hills; 9.1-7.7 kyr BP at Mims Spur; and around 7 kyr BP at Hatcher Bluffs. We attribute this time-transgressive behavior to two different processes: At the glacier mouth, growth of grounded ice and subsequent deglaciation in the Ross Sea embayment caused a wave of thickening and then thinning to propagate up-glacier. During the Lateglacial and Holocene, increased snow accumulation on the East Antarctic Ice Sheet caused transient thickening at the head of the glacier. An important result of this work is that moraines deposited along Reedy Glacier during the last ice age cannot be correlated to reconstruct a single glacial maximum longitudinal profile. The profile steepened during deglaciation of the Ross Sea, thinning at the Quartz Hills after 13 kyr BP while thickening upstream. Near its confluence with Mercer Ice Stream, rapid thinning beginning prior to 7-8 kyr BP reduced the level of Reedy Glacier to close to its present level. Thinning over the past 1000 years has lowered the glacier by less than 20 m.

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Understanding the distribution and foraging ecology of major consumers within pelagic systems, specifically in relation to physical parameters, can be important for the management of bentho-pelagic systems undergoing rapid change associated with global climate change and other anthropogenic disturbances such as fishing (i.e., the Antarctic Peninsula and Scotia Sea). We tracked 11 adult male southern elephant seals (Mirounga leonina), during their five-month post-moult foraging migrations from King George Island (Isla 25 de Mayo), northern Antarctic Peninsula, using tags capable of recording and transmitting behavioural data and in situ temperature and salinity data. Seals foraged mostly within the Weddell-Scotia Confluence, while a few foraged along the western Antarctic Peninsula shelf of the Bellingshausen Sea. Mixed model outputs suggest that the at-sea behaviour of seals was associated with a number of environmental parameters, especially seafloor depth, sea-ice concentrations and the temperature structure of the water column. Seals increased dive bottom times and travelled at slower speeds in shallower areas and areas with increased sea-ice concentrations. Changes in dive depth and durations, as well as relative amount of time spent during the bottom phases of dives, were observed in relation to differences in overall temperature gradient, likely as a response to vertical changes in prey distribution associated with temperature stratification in the water column. Our results illustrate the likely complex influences of bathymetry, hydrography and sea ice on the behaviour of male southern elephant seals in a changing environment and highlight the need for region-specific approaches to studying environmental influences on behaviour.