828 resultados para 832
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"3 February 1965."
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Mineral dust has a large impact on regional and global climate, depending on its particle size. Especially in the Atlantic Ocean downwind of the Sahara, the largest dust source on earth, the effects can be substantial but are poorly understood. This study focuses on seasonal and spatial variations in particle size of Saharan dust deposition across the Atlantic Ocean, using an array of submarine sediment traps moored along a transect at 12° N. We show that the particle size decreases downwind with increased distance from the Saharan source, due to higher gravitational settling velocities of coarse particles in the atmosphere. Modal grain sizes vary between 4 and 33 µm throughout the different seasons and at five locations along the transect. This is much coarser than previously suggested and incorporated into climate models. In addition, seasonal changes are prominent, with coarser dust in summer, and finer dust in winter and spring. Such seasonal changes are caused by transport at higher altitudes and at greater wind velocities during summer than in winter. Also the latitudinal migration of the dust cloud, associated with the Intertropical Convergence Zone, causes seasonal differences in deposition as the summer dust cloud is located more to the north, and more directly above the sampled transect. Furthermore, increased precipitation and more frequent dust storms in summer coincide with coarser dust deposition. Our findings contribute to understanding Saharan dust transport and deposition relevant for the interpretation of sedimentary records for climate reconstructions, as well as for global and regional models for improved prediction of future climate.
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The aim of this study was to determine the most informative sampling time(s) providing a precise prediction of tacrolimus area under the concentration-time curve (AUC). Fifty-four concentration-time profiles of tacrolimus from 31 adult liver transplant recipients were analyzed. Each profile contained 5 tacrolimus whole-blood concentrations (predose and 1, 2, 4, and 6 or 8 hours postdose), measured using liquid chromatography-tandem mass spectrometry. The concentration at 6 hours was interpolated for each profile, and 54 values of AUC(0-6) were calculated using the trapezoidal rule. The best sampling times were then determined using limited sampling strategies and sensitivity analysis. Linear mixed-effects modeling was performed to estimate regression coefficients of equations incorporating each concentration-time point (C0, C1, C2, C4, interpolated C5, and interpolated C6) as a predictor of AUC(0-6). Predictive performance was evaluated by assessment of the mean error (ME) and root mean square error (RMSE). Limited sampling strategy (LSS) equations with C2, C4, and C5 provided similar results for prediction of AUC(0-6) (R-2 = 0.869, 0.844, and 0.832, respectively). These 3 time points were superior to C0 in the prediction of AUC. The ME was similar for all time points; the RMSE was smallest for C2, C4, and C5. The highest sensitivity index was determined to be 4.9 hours postdose at steady state, suggesting that this time point provides the most information about the AUC(0-12). The results from limited sampling strategies and sensitivity analysis supported the use of a single blood sample at 5 hours postdose as a predictor of both AUC(0-6) and AUC(0-12). A jackknife procedure was used to evaluate the predictive performance of the model, and this demonstrated that collecting a sample at 5 hours after dosing could be considered as the optimal sampling time for predicting AUC(0-6).
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Os consumidores de baixa renda pertencentes às classes C, D e E, representam 77% da população brasileira, uma fatia de mercado até então desvalorizadas pelas empresas. Após o Plano Real estes consumidores aumentaram sua participação na aquisição de produtos e serviços, e hoje correspondem a aproximadamente 45% do consumo brasileiro. Visando atender essa grande parcela da população muitas empresas passaram a desenvolver produtos com preços inferiores, mas com qualidade confiável. O estudo investigará o potencial mercadológico destes consumidores e terá como foco principal apresentar as estratégias de comunicação desenvolvidas pelas empresas de higiene pessoal, perfumaria e cosméticos, cujos produtos são destinados aos consumidores de baixa renda.
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The identification of disease clusters in space or space-time is of vital importance for public health policy and action. In the case of methicillin-resistant Staphylococcus aureus (MRSA), it is particularly important to distinguish between community and health care-associated infections, and to identify reservoirs of infection. 832 cases of MRSA in the West Midlands (UK) were tested for clustering and evidence of community transmission, after being geo-located to the centroids of UK unit postcodes (postal areas roughly equivalent to Zip+4 zip code areas). An age-stratified analysis was also carried out at the coarser spatial resolution of UK Census Output Areas. Stochastic simulation and kernel density estimation were combined to identify significant local clusters of MRSA (p<0.025), which were supported by SaTScan spatial and spatio-temporal scan. In order to investigate local sampling effort, a spatial 'random labelling' approach was used, with MRSA as cases and MSSA (methicillin-sensitive S. aureus) as controls. Heavy sampling in general was a response to MRSA outbreaks, which in turn appeared to be associated with medical care environments. The significance of clusters identified by kernel estimation was independently supported by information on the locations and client groups of nursing homes, and by preliminary molecular typing of isolates. In the absence of occupational/ lifestyle data on patients, the assumption was made that an individual's location and consequent risk is adequately represented by their residential postcode. The problems of this assumption are discussed, with recommendations for future data collection.
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An analogous thinking task was used to test Nemeth's Convergent–Divergent theory of majority and minority influence. Participants read a (base) problem and one of three solutions (one of which is considered the ‘best' solution). They then generated solutions to a second (target) problem which shared similar structural features to the first problem. Due to the similarities between problems, the solution given to the first problem can be used as an analogy in solving the second. In contrast to Nemeth's theory, when the solution to the base problem was endorsed by a numerical majority there was not an increase in analogy-transfer in solving the target problem. However, in support of Nemeth's theory, when the base solution was supported by a numerical minority then the participants were more likely to generate the ‘best' solution to the target problem regardless of which base solution they were given. Copyright © 1999 John Wiley & Sons, Ltd.
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A pénzügy kutatócsoport a TÁMOP-4.2.1.B-09/1/KMR-2010-0005 azonosítójú projektjében igen szerteágazó elemzési munkát végzett. Rámutattunk, hogy a különböző szintű gazdasági szereplők megnövekedett tőkeáttétele egyértelműen a rendszerkockázat növekedéséhez vezet, hiszen nő az egyes szereplők csődjének valószínűsége. Ha a tőkeáttételt eltérő mértékben és ütemben korlátozzák az egyes szektorokban, országokban akkor a korlátozást később bevezető szereplők egyértelműen versenyelőnyhöz jutnak. Az egyes pénzügyi intézmények tőkeallokációját vizsgálva kimutattuk, hogy a különféle divíziók közt mindig lehetséges a működés fedezetésül szolgáló tőkét (kockázatot) úgy felosztani, hogy a megállapodás felmondás egyik érintettnek se álljon érdekében. Ezt azonban nem lehet minden szempontból igazságosan megtenni, így egyes üzletágak versenyhátrányba kerülhetnek, ha a konkurens piaci szereplők az adott tevékenységet kevésbé igazságtalanul terhelték meg. Kimutattunk, hogy az egyes nyugdíjpénztárak befektetési tevékenységének eredményességére nagy hatással van a magánnyugdíjpénztárak tevékenységének szabályozása. Ezek a jogszabályok a társadalom hosszú távú versenyképességére vannak hatással. Rámutattunk arra is, hogy a gazdasági válság előtt a hazai bankok sem voltak képesek ügyfeleik kockázatviselő képességét helyesen megítélni, ráadásul jutalékrendszerük nem is tette ebben érdekelté azokat. Számos vizsgálatunk foglalkozott a magyar vállalatok versenyképességének alakulásával is. Megvizsgáltuk a különféle adónemek, árfolyamkockázatok és finanszírozási politikák versenyképességet befolyásoló hatását. Külön kutatás vizsgálta a kamatlábak ingadozásának és az hitelekhez kapcsolódó eszközfedezet meglétének vállalati értékre gyakorolt hatásait. Rámutattunk a nemfizetés növekvő kockázatára, és áttekintettük a lehetséges és a ténylegesen alkalmazott kezelési stratégiákat is. Megvizsgáltuk azt is, hogy a tőzsdei cégek tulajdonosai miként használják ki az osztalékfizetéshez kapcsolódó adóoptimalizálási lehetőségeket. Gyakorlati piaci tapasztalataik alapján az adóelkerülő kereskedést a befektetők a részvények egy jelentős részénél végrehajtják. Külön kutatás foglakozott a szellemi tőke hazai vállalatoknál játszott szerepéről. Ez alapján a cégek a problémát 2009-ben lényegesen magasabb szakértelemmel kezelték, mint öt esztendővel korábban. Rámutattunk arra is, hogy a tulajdonosi háttér lényeges hatást gyakorolhat arra, ahogyan a cégek célrendszerüket felépítik, illetve ahogy az intellektuális javakra tekintenek. _____ The Finance research team has covered a wide range of research fields while taking part at project TÁMOP-4.2.1.B-09/1/KMR-2010-0005. It has been shown that the increasing financial gearing at the different economic actors clearly leads to growth in systematic risk as the probability of bankruptcy climbs upwards. Once the leverage is limited at different levels and at different points in time for the different sectors, countries introducing the limitations later gain clearly a competitive advantage. When investigating the leverage at financial institutions we found that the capital requirement of the operation can always be divided among divisions so that none of them would be better of with cancelling the cooperation. But this cannot be always done fairly from all point of view meaning some of the divisions may face a competitive disadvantage if competitors charge their similar division less unfairly. Research has also shown that the regulation of private pension funds has vital effect on the profitability of the investment activity of the funds. These laws and regulations do not only affect the funds themselves but also the competitiveness of the whole society. We have also fund that Hungarian banks were unable to estimate correctly the risk taking ability of their clients before the economic crisis. On the top of that the bank were not even interested in that due to their commission based income model. We also carried out several research on the competitiveness of the Hungarian firms. The effect of taxes, currency rate risks, and financing policies on competitiveness has been analysed in detail. A separate research project was dedicated to the effect of the interest rate volatility and asset collaterals linked to debts on the value of the firm. The increasing risk of non-payment has been underlined and we also reviewed the adequate management strategies potentially available and used in real life. We also investigated how the shareholders of listed companies use the tax optimising possibilities linked to dividend payments. Based on our findings on the Hungarian markets the owners perform the tax evading trades in case of the most shares. A separate research has been carried out on the role played by intellectual capital. After that the Hungarian companies dealt with the problem in 2009 with far higher proficiency than five years earlier. We also pointed out that the ownership structure has a considerable influence on how firms structure their aims and view their intangible assets.
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Extensive investigations of sedimentary barium were performed in the southern South Atlantic in order to assess the reliability of the barium signal in Antarctic sediments as a proxy for paleoproductivity. Maximum accumulation rates of excess barium were calculated for the Antarctic zone south of the polar front where silica accumulates at high rates. The correspondence between barium and opal supports the applicability of barium as a proxy for productivity. Within the Antarctic zone north of today's average sea ice maximum, interglacial vertical rain rates of excess barium are high, with a maximum occurring during the last deglaciation and early Holocene and during oxygen isotope chronozone 5.5. During these periods, the maximum silica accumulation was supposedly located south of the polar front. Glacial paleoproductivity, instead, was low within the Antarctic zone. North of the polar front, significantly higher barium accumulation occurs during glacial times. The vertical rain rates, however, are as high as in the glacial Antarctic zone. Therefore there was no evidence for an increased productivity in the glacial Southern Ocean.
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Fish stomach content records extracted from the DAPSTOM 4.5 database (held at the UK Centre for Environment, Fisheries and Aquaculture Science - CEFAS). Data collated as part of the EU Euro-Basin project and specifically concerning herring (Clupea harengus), mackerel (Scomber scombrus), blue whiting (Micromesistius poutassou), albacore (Thunnus alalunga) and bluefin tuna (Thunnus thynnus). The data set consist of 20720 records - collected throughout the northeast Atlantic, between 1906 and 2011 - mostly during routine fisheries monitoring research cruises.
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Sedimentation of pelagic biogenic coccolithic-foraminiferal sediments predominates in the section of the South Atlantic ridge between 20° and 30°S. Sedimentation rate and thickness of Late Quaternary sediments differ in the rift valley, the crestal section of the ridge, its flanks and transform faults. Holocene and layers representing the most recent and pen¬ultimate continental glaciations and the last interglacial are distinguishable in the late Quaternary profile. During their development, changes in the mean annual sea surface temperature in the tropical zone of the South Atlantic were minimal, i.e. 1-2°C.
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During expedition 202 of research vessel SONNE in 2009, 39 sea-floor surface sediments were sampled over a wide area across the North Pacific and the Bering Sea, which are well suited as reference archives of modern environmental processes. In this study, we used the samples to infer the documentation of land-ocean linkages of terrigenous sediment supply. We followed an integrated approach of grain-size analysis, bulk mineralogy, and clay mineralogy in combination with statistical data evaluation (end-member modelling of grain-size data, fuzzy-cluster analysis of mineralogical data), in order to identify the significant sources and modes of sediment transport in an overregional context. We also compiled literature data on clay mineralogy and updated those with the new data. Today, two processes of terrigenous sediment supply prevail in the study area: far-distant aeolian sediment supply to the pelagic North Pacific as well as hemipelagic sediment dispersal from nearby land sources by ocean currents along the continental margins and island arcs of the study area. The aeolian particles show the finest grain sizes (clay and fine silt), while the hemipelagic sediments have high abundances of sortable silt, particles >10 microns.