969 resultados para Local effects


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It is generally agreed that changing climate variability, and the associated change in climate extremes, may have a greater impact on environmentally vulnerable regions than a changing mean. This research investigates rainfall variability, rainfall extremes, and their associations with atmospheric and oceanic circulations over southern Africa, a region that is considered particularly vulnerable to extreme events because of numerous environmental, social, and economic pressures. Because rainfall variability is a function of scale, high-resolution data are needed to identify extreme events. Thus, this research uses remotely sensed rainfall data and climate model experiments at high spatial and temporal resolution, with the overall aim being to investigate the ways in which sea surface temperature (SST) anomalies influence rainfall extremes over southern Africa. Extreme rainfall identification is achieved by the high-resolution microwave/infrared rainfall algorithm dataset. This comprises satellite-derived daily rainfall from 1993 to 2002 and covers southern Africa at a spatial resolution of 0.1° latitude–longitude. Extremes are extracted and used with reanalysis data to study possible circulation anomalies associated with extreme rainfall. Anomalously cold SSTs in the central South Atlantic and warm SSTs off the coast of southwestern Africa seem to be statistically related to rainfall extremes. Further, through a number of idealized climate model experiments, it would appear that both decreasing SSTs in the central South Atlantic and increasing SSTs off the coast of southwestern Africa lead to a demonstrable increase in daily rainfall and rainfall extremes over southern Africa, via local effects such as increased convection and remote effects such as an adjustment of the Walker-type circulation.

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Many climate models have problems simulating Indian summer monsoon rainfall and its variability, resulting in considerable uncertainty in future projections. Problems may relate to many factors, such as local effects of the formulation of physical parametrisation schemes, while common model biases that develop elsewhere within the climate system may also be important. Here we examine the extent and impact of cold sea surface temperature (SST) biases developing in the northern Arabian Sea in the CMIP5 multi-model ensemble, where such SST biases are shown to be common. Such biases have previously been shown to reduce monsoon rainfall in the Met Office Unified Model (MetUM) by weakening moisture fluxes incident upon India. The Arabian Sea SST biases in CMIP5 models consistently develop in winter, via strengthening of the winter monsoon circulation, and persist into spring and summer. A clear relationship exists between Arabian Sea cold SST bias and weak monsoon rainfall in CMIP5 models, similar to effects in the MetUM. Part of this effect may also relate to other factors, such as forcing of the early monsoon by spring-time excessive equatorial precipitation. Atmosphere-only future time-slice experiments show that Arabian Sea cold SST biases have potential to weaken future monsoon rainfall increases by limiting moisture flux acceleration through non-linearity of the Clausius-Clapeyron relationship. Analysis of CMIP5 model future scenario simulations suggests that, while such effects are likely small compared to other sources of uncertainty, models with large Arabian Sea cold SST biases suppress the range of potential outcomes for changes to future early monsoon rainfall.

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Windstorms are a main feature of the European climate and exert strong socioeconomic impacts. Large effort has been made in developing and enhancing models to simulate the intensification of windstorms, resulting footprints, and associated impacts. Simulated wind or gust speeds usually differ from observations, as regional climate models have biases and cannot capture all local effects. An approach to adjust regional climate model (RCM) simulations of wind and wind gust toward observations is introduced. For this purpose, 100 windstorms are selected and observations of 173 (111) test sites of the German Weather Service are considered for wind (gust) speed. Theoretical Weibull distributions are fitted to observed and simulated wind and gust speeds, and the distribution parameters of the observations are interpolated onto the RCM computational grid. A probability mapping approach is applied to relate the distributions and to correct the modeled footprints. The results are not only achieved for single test sites but for an area-wide regular grid. The approach is validated using root-mean-square errors on event and site basis, documenting that the method is generally able to adjust the RCM output toward observations. For gust speeds, an improvement on 88 of 100 events and at about 64% of the test sites is reached. For wind, 99 of 100 improved events and ~84% improved sites can be obtained. This gives confidence on the potential of the introduced approach for many applications, in particular those considering wind data.

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Temperature is a key variable for monitoring global climate change. Here we perform a trend analysis of Swiss temperatures from 1959 to 2008, using a new 2 × 2 km gridded data-set based on carefully homogenised ground observations from MeteoSwiss. The aim of this study is twofold: first, to discuss the spatial and altitudinal temperature trend characteristics in detail, and second, to quantify the contribution of changes in atmospheric circulation and local effects to these trends. The seasonal trends are all positive and mostly significant with an annual average warming rate of 0.35 °C/decade (∼1.6 times the northern hemispheric warming rate), ranging from 0.17 in autumn to 0.48 °C/decade in summer. Altitude-dependent trends are found in autumn and early winter where the trends are stronger at low altitudes (<800 m asl), and in spring where slightly stronger trends are found at altitudes close to the snow line. Part of the trends can be explained by changes in atmospheric circulation, but with substantial differences from season to season. In winter, circulation effects account for more than half the trends, while this contribution is much smaller in other seasons. After removing the effect of circulation, the trends still show seasonal variations with higher values in spring and summer. The circulation-corrected trends are closer to the values simulated by a set of ENSEMBLES regional climate models, with the models still tending towards a trend underestimation in spring and summer. Our results suggest that both circulation changes and more local effects are important to explain part of recent warming in spring, summer, and autumn. Snow-albedo feedback effects could be responsible for the stronger spring trends at altitudes close to the snow line, but the overall effect is small. In autumn, the observed decrease in fog frequency might be a key process in explaining the stronger temperature trends at low altitudes.

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This work attempts to establish dermatological identification patterns for Brazilian enidarian species and it probable correlation with envenoming, severity In all observational prospective study, one hundred and twenty-eight patients from the North Coast re-ion of São Paulo State, Brazil were seen between 2002 and 2008. About 80% of these Showed only local effects (erythema, edema, and pain) with small, less than 20 cm, oval or round skin marks and impressions from Small tentacles. Approximately 20% of the victims had long, more than 20 cm, linear and crossed marks with frequent systemic phenomena, such as malaise, vomiting, dyspnea, and tachycardia. The former is compatible with the common hydromedusa from Southeast and Southern Brazil (Olindias sambaquiensis). The long linear marks with intense pain and systemic phenomena are compatible with envenoming, by the box jellyfish Tamoya haplonema and Chiropsalmus quadrumanus and the hydrozoan Portuguese man-of-war (Physalis physalis). There was an association between Skin marks and probable accident etiology. This simple observation rule can be indicative of severity as the Cubozoa Class (box jellyfish) and Portuguese man-of-war cause the most severe accidents. In such cases, medical attention, including intensive care, is important, as the systemic manifestations call be associated with death.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A method for spatial electric load forecasting using multi-agent systems, especially suited to simulate the local effect of special loads in distribution systems is presented. The method based on multi-agent systems uses two kinds of agents: reactive and proactive. The reactive agents represent each sub-zone in the service zone, characterizing each one with their corresponding load level, represented in a real number, and their relationships with other sub-zones represented in development probabilities. The proactive agent carry the new load expected to be allocated because of the new special load, this agent distribute the new load in a propagation pattern. The results are presented with maps of future expected load levels in the service zone. The method is tested with data from a mid-size city real distribution system, simulating the effect of a load with attraction and repulsion attributes. The method presents good results and performance. © 2011 IEEE.

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The framework of this study was to comprehend the specific conditions surrounding the incorporation and political-economical consolidation of the state of Mato Grosso Sul to the national scenario, during the cyclic evolution of the capitalistic system as well as the role of Campo Grande in this process. The origin and evolution of Campo Grande were analyzed in the context of possible relations between urbanization, regional development and the integration of the state in the national scope. In this approach, several theoretical compatible formulations were considered as to systemic view of reality, from the complex and dynamic point of view. This implies a multi scale reasoning, associating spatial dimension to the historical one, in a theoretical- methodological effort of comprehend the logic between the general and the specific. It was possible to verity peculiarities attributed to Mato Grosso do Sul in the general laws of the capitalistic system, and instances capable of explaning the local effects of the intervention of industrial economy in the dynamic of the process analysed since colonial times, as well as the role of Campo Grande in this process, especially in relation to the economical integration of the state territory to the rest of the nation.

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Two types of mesoscale wind-speed jet and their effects on boundary-layer structure were studied. The first is a coastal jet off the northern California coast, and the second is a katabatic jet over Vatnajökull, Iceland. Coastal regions are highly populated, and studies of coastal meteorology are of general interest for environmental protection, fishing industry, and for air and sea transportation. Not so many people live in direct contact with glaciers but properties of katabatic flows are important for understanding glacier response to climatic changes. Hence, the two jets can potentially influence a vast number of people. Flow response to terrain forcing, transient behavior in time and space, and adherence to simplified theoretical models were examined. The turbulence structure in these stably stratified boundary layers was also investigated. Numerical modeling is the main tool in this thesis; observations are used primarily to ensure a realistic model behavior. Simple shallow-water theory provides a useful framework for analyzing high-velocity flows along mountainous coastlines, but for an unexpected reason. Waves are trapped in the inversion by the curvature of the wind-speed profile, rather than by an infinite stability in the inversion separating two neutral layers, as assumed in the theory. In the absence of blocking terrain, observations of steady-state supercritical flows are not likely, due to the diurnal variation of flow criticality. In many simplified models, non-local processes are neglected. In the flows studied here, we showed that this is not always a valid approximation. Discrepancies between simulated katabatic flow and that predicted by an analytical model are hypothesized to be due to non-local effects, such as surface inhomogeneity and slope geometry, neglected in the theory. On a different scale, a reason for variations in the shape of local similarity scaling functions between studies is suggested to be differences in non-local contributions to the velocity variance budgets.

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Heat treatment of steels is a process of fundamental importance in tailoring the properties of a material to the desired application; developing a model able to describe such process would allow to predict the microstructure obtained from the treatment and the consequent mechanical properties of the material. A steel, during a heat treatment, can undergo two different kinds of phase transitions [p.t.]: diffusive (second order p.t.) and displacive (first order p.t.); in this thesis, an attempt to describe both in a thermodynamically consistent framework is made; a phase field, diffuse interface model accounting for the coupling between thermal, chemical and mechanical effects is developed, and a way to overcome the difficulties arising from the treatment of the non-local effects (gradient terms) is proposed. The governing equations are the balance of linear momentum equation, the Cahn-Hilliard equation and the balance of internal energy equation. The model is completed with a suitable description of the free energy, from which constitutive relations are drawn. The equations are then cast in a variational form and different numerical techniques are used to deal with the principal features of the model: time-dependency, non-linearity and presence of high order spatial derivatives. Simulations are performed using DOLFIN, a C++ library for the automated solution of partial differential equations by means of the finite element method; results are shown for different test-cases. The analysis is reduced to a two dimensional setting, which is simpler than a three dimensional one, but still meaningful.

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Geprägte Gene besitzen die Besonderheit, dass sie jeweils nur von einem Allel exprimiert werden und in der Regel in Imprinting Clustern (ICs) im Genom vorliegen. Bei der Regulation in solchen ICs spielen differentiell methylierte Imprinting Kontrollregionen (ICRs) und dort stattfindende Proteinbindungen eine wichtige Rolle. Die essentielle Bedeutung der CTCF-Bindung an die ICR1 in 11p15.5 für die Expressionsregulation der geprägten Gene H19 und IGF2 ist bereits bekannt. In der vorliegenden Arbeit sollte die Bindung von Kaiso an die unmethylierte ICR1 bei humanen Zellen mit maternaler uniparentaler Disomie von 11p15 (upd(11p15)mat) nachgewiesen und die genaue Bindungsverteilung von Kaiso und CTCF in den B-Repeats der Kontrollregion bestimmt werden. Cis-regulatorische und chromosomenübergreifende transkriptionelle Effekte der ICR1-Proteinbindungen sollten dann durch qPCR-Analysen geprägter Gene bei Zellen mit maternaler und paternaler upd(11p15) und nach siRNA-basierter Herunterregulation der beiden Proteine in Zellen mit upd(11p15)mat analysiert werden. In der vorliegenden Arbeit konnte erstmals gezeigt werden, dass Kaiso an die unmethylierte ICR1 bindet. Dabei kann zumindest von einer Bindestellennutzung in der distalen ICR1-Hälfte ausgegangen werden. Für CTCF hingegen wurde eine Nutzung aller analysierten Repeats in beiden ICR1-Hälften gefunden. In der maternalen bzw. paternalen upd(11p15) entspricht die Expression der 11p15.5-Gene IGF2, H19, CDKN1C und KCNQ1OT1 dem jeweiligen Disomie-Status. Von den nicht auf Chromosom 11 gelegenen geprägten Genen zeigen MEST und PLAGL1 bei Zellen mit upd(11p15)pat sowie PEG3 und GRB10 bei der upd(11p15)mat eine stärkere Expression. Ein CTCF-knockdown in Zellen mit upd(11p15)mat führt zur IGF2-Expressionssteigerung. Dies tritt in noch stärkerem Maße beim knockdown von Kaiso auf, wobei hier zusätzlich eine gesteigerte Expression von H19 vorliegt. Des Weiteren findet man beim CTCF-knockdown einen MEST-Expressionsanstieg und beim Kaiso-knockdown gesteigerte Expressionen der Gene PEG3, GRB10 und PLAGL1. Damit lassen sich sowohl eigenständige cis-regulatorische Effekte der ICR1-Bindung beider Proteine auf geprägte Gene des IC1 als auch chromosomenübergreifende Effekte erkennen. Vor allem die starken H19-Expressionsanstiege beim Kaiso-knockdown treten korrelierend mit Veränderungen von geprägten Genen anderer Chromosomen auf. Damit unterstützen die Daten die Theorie, dass die Expressionsregulation geprägter Gene koordiniert in einer Art Netzwerk stattfinden könnte und dabei bestimmte Faktoren wie H19 und PLAGL1 eine übergeordnete Regulatorfunktion besitzen, wie es in Vergangenheit in der Maus beschrieben wurde. Die Expressionsanalysen von PLAGL1 und MEST deuten darüber hinaus durch ihre tendenziell übereinstimmenden Werte bei der paternalen upd mit hypermethylierter ICR1 und den knockdowns auf die Existenz von Chromatin-Interaktionen zwischen der ICR1 und Abschnitten auf den Chromosomen 6 und 7 hin, ggf. mit einem entsprechenden lokalen Effekt der Proteine in diesen Loci. Proteinbindungen an die maternale ICR1 scheinen damit sowohl cis-regulatorisch die Transkription der geprägten Gene IGF2 und H19 zu beeinflussen als auch durch die H19-Expression ein funktionelles Netzwerk geprägter Gene als trans-Faktor zu regulieren und für Interaktionen zwischen verschiedenen Chromosomen mit transkriptionsregulierender Wirkung verantwortlich zu sein.

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Duchenne muscular dystrophy (DMD) is a hereditary X-linked recessive disorder affecting the synthesis of dystrophin, a protein essential for structural stability in muscle. Dystrophin also occurs in the central nervous system, particularly in the neocortex, hippocampus and cerebellum. Quantitative metabolic analysis by localized (1) H MRS was performed in the cerebellum (12 patients and 15 controls) and a temporo-parietal location (eight patients and 15 controls) in patients with DMD and healthy controls to investigate possible metabolic differences. In addition, the site of individual mutations on the dystrophin gene was analyzed and neuropsychological cognitive functions were examined. Cognitive deficits in the patient group were found in line with earlier investigations, mainly concerning verbal short-term memory, visuo-spatial long-term memory and verbal fluency, but also the full-scale IQ. Causal mutations were identified in all patients with DMD. Quantitative MRS showed consistent choline deficits, in both cerebellar white matter and temporo-parietal cortex, as well as small, but significant, metabolic abnormalities for glutamate and total N-acetyl compounds in the temporo-parietal region. Compartment water analysis did not reveal any abnormalities. In healthy subjects, choline levels were age related in the cerebellum. The choline deficit contrasts with earlier findings in DMD, where a surplus of choline was postulated for the cerebellum. In patients, total N-acetyl compounds in the temporo-parietal region were related to verbal IQ and verbal short-term memory. However, choline, the putative main metabolic abnormality, was not found to be associated with cognitive deficits. Furthermore, in contrast with the cognitive performance, the metabolic brain composition did not depend significantly on whether or not gene mutations concerned the expression of the dystrophin isoform Dp140, leading to the conclusion that the effect of the missing Dp140 isoform on cognitive performance is not mediated through the observed metabolite composition, or is caused by local effects beyond the resolution accessible to MRS investigations.

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Background: After oral tumor resection, structural and functional rehabilitation by means of dental prostheses is complex, and positive treatment outcome is not always predictable. Purpose: The objective of the study was to report on oral rehabilitation and quality of life 2-5 years after resection of malignant oral tumors. Materials and Methods: Data of 46 patients (57 ± 7 years) who underwent oral tumor surgery were available. More than 50% of tumors were classified T3 or T4. Open oro-nasal defects resulted in 12 patients and full mandibulary block resections in 23 patients. Comprehensive planning, implant placement, and prosthetic rehabilitation followed an interdisciplinary protocol. Analysis comprised tumor location, type of prostheses, implant survival, and quality of life. Results: Because of advanced tumor status, resections resulted in marked alteration of the oral anatomy requiring complex treatment procedures. Prosthetic rehabilitation comprised fixed and removable prostheses, with 104 implants placed in 28 patients (60%). Early implant loss was high (13%) and cumulative survival rate of loaded implants was <90% after 5 years. Prosthetic plans had to be modified because of side effects of tumor therapy, complications with implants and tumor recurrence. The majority of patients rated quality of life favorable, but some experienced impaired swallowing, dry mouth, limited mouth opening, appearance, and soreness. Conclusions: Some local effects of tumor therapy could not be significantly improved by prosthetic rehabilitation leading to functional and emotional disability. Many patients had passed away or felt too ill to fill the questionnaires. This case series confirms the complex anatomic alterations after tumor resection and the need for individual treatment approaches especially regarding prosthesis design. In spite of disease-related local and general restrictions, most patients gave a positive assessment of quality of life.