53 research outputs found

    Anti-aliasing with stratified B-spline filters of arbitrary degree

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    A simple and elegant method is presented to perform anti-aliasing in raytraced images. The method uses stratified sampling to reduce the occurrence of artefacts in an image and features a B-spline filter to compute the final luminous intensity at each pixel. The method is scalable through the specification of the filter degree. A B-spline filter of degree one amounts to a simple anti-aliasing scheme with box filtering. Increasing the degree of the B-spline generates progressively smoother filters. Computation of the filter values is done in a recursive way, as part of a sequence of Newton-Raphson iterations, to obtain the optimal sample positions in screen space. The proposed method can perform both anti-aliasing in space and in time, the latter being more commonly known as motion blur. We show an application of the method to the ray casting of implicit procedural surfaces

    Use of antipsychotic drugs. A multicentric study of inpatients with acute psychotic disorders

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    Com o objectivo de caracterizar o padrão e os determinantes de utilização de fármacos antipsicóticos por via intra-muscular em indivíduos hospitalizados por perturbação psicótica aguda, efectuou-se um estudo retrospectivo de 244 indivíduos, admitidos em sete unidades hospitalares de internamento psiquiátrico. Foram seleccionados dois grupos, IM (Intra Muscular) e PO (Via Oral), que nos primeiros três dias de internamento receberam respectivamente medicação antipsicótica por via intramuscular ou por via oral, tendo-se explorado as eventuais diferenças nas áreas demográfica, clínica e terapêutica (com revisão dos casos aos 6 e 12 meses após a alta hospitalar). Os dois grupos foram homogéneos quanto à idade, raça, sexo, idade do início da doença e diagnóstico, tendo-se verificado um número maior de internamentos compulsivos no grupo IM. As perturbações psicóticas mais prevalentes em ambos os grupos foram a esquizofrenia e a perturbação bipolar, não se tendo encontrado qualquer associação entre os diagnósticos iniciais e a via de administração dos fármacos. O tempo de hospitalização foi igual entre grupos, embora nos doentes do grupo IM tivesse sido necessário tomar medidas de precaução especiais com maior frequência. A medicação ansiolítica foi superior no grupo PO nos dias um e dois de hospitalização e igual nos dois grupos no dia três e no dia de alta. A terapêutica anticolinérgica foi semelhante entre os dois grupos. O número de novas hospitalizações, bem como a percentagem de doentes a utilizar medicação antipsicótica, ansiolítica e anticolinérgica, foi semelhante nos dois grupos após 6 e 12 meses de seguimento. Neste estudo, a presença de agitação psicomotora e de comportamentos agressivo/destrutivo na fase inicial do internamento no grupo IM (incluindo o primeiro contacto, maioritariamente feito no serviço de urgência) foram os elementos estatisticamente determinantes da utilização da via intramuscular para a administração dos fármacos antipsicóticos. With the objective of determining the pattern and decision making process in using antipsychotic drugs in patients admitted to hospital for acute psychotic disorder we have made a retrospective analysis in 244 in-patients in 7 hospitals for mental disorders. We have selected two groups, IM and PO, that in the first three days of internment have received either intravenous antipsychotic medication or oral medication; the demographical, clinical and therapeutical differences have been considered (with a review of the cases at 6 and 12 months after discharge from hospital). Homogeneity was considered regarding age, race, gender, age at the onset of the disease and diagnosis; in the IM group there were a larger number of compulsive admissions. The most prevalent psychotic disorders in both groups were schizophrenia and bipolar disorder; with no association being made between the initial diagnosis and drug administration. The hospitalization period was the same for both groups, although in the patients in the IM group the need for special precautions was more frequent. Medication with anxiolytics was higher in the PO group on day 1 and 2 of the hospitalization and the same for the two groups on day 3 and on discharge. The number of new admissions, as well as the percentage of patients taking antipsychotic, anxiolytic and anticholinergic medication was similar in both groups after a period of 6 and 12 months follow-up. In this study, agitation and aggressive/destructive behaviours in the initial phase of hospitalization in the IM group (including the first contact, most of the times on admission at the ER) were statistically significant factors for the use of intramuscular administration of antipsychotic drugs.publishersversionpublishe

    Redating the formation of Lake Bafa, western Turkey: Integrative geoarchaeological methods and new environmental and dating evidence

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    The ancient Gulf of Latmos is an iconic example of a dynamic landscape and humankind's historical relationship with it. Using extensive new primary data and original models for calibrating radiocarbon dates in transitional lagoon environments, we demonstrate that Lake Bafa (or Bafa Gölü, in Turkish) formed at a much earlier date than previously thought. In questioning the logical process by which previous dates were achieved, we re‐examine the relationship between sedimentological data, archaeology and written history. We reassert the need to establish independently dated environmental data sets as the foundation of regional studies as distinct from archaeological and historical interpretive processes. We conclude that Lake Bafa slowly transitioned to become an isolated lagoon sometime between the end of the second millennium B.C. and end of the first millennium B.C.; becoming a fully closed brackish lake during the second millennium A.D. This marks a major shift in our understanding of the nature of human occupation and activity here during the last four millennia but also in the way we date ancient lagoons and integrate historical and environmental data in general

    Comparación de distintas estrategias para la predicción de muerte a corto plazo en el paciente anciano infectado

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    Objective. The aim of this study was to determine the utility of a post hoc lactate added to SIRS and qSOFA score to predict 30-day mortality in older non-severely dependent patients attended for infection in the Emergency Department (ED). Methods. We performed an analytical, observational, prospective cohort study including patients of 75 years of age or older, without severe functional dependence, attended for an infectious disease in 69 Spanish ED for 2-day three seasonal periods. Demographic, clinical and analytical data were collected. The primary outcome was 30-day mortality after the index event. Results. We included 739 patients with a mean age of 84.9 (SD 6.0) years; 375 (50.7%) were women. Ninety-one (12.3%) died within 30 days. The AUC was 0.637 (IC 95% 0.587-0.688; p= 2 and 0.698 (IC 95% 0.635- 0.761; p= 2. Comparing receiver operating characteristic (ROC) there was a better accuracy of qSOFA vs SIRS (p=0.041). Both scales improve the prognosis accuracy with lactate inclusion. The AUC was 0.705 (IC95% 0.652-0.758; p<0.001) for SIRS plus lactate and 0.755 (IC95% 0.696-0.814; p<0.001) for qSOFA plus lactate, showing a trend to statistical significance for the second strategy (p=0.0727). Charlson index not added prognosis accuracy to SIRS (p=0.2269) or qSOFA (p=0.2573). Conclusions. Lactate added to SIRS and qSOFA score improve the accuracy of SIRS and qSOFA to predict short-term mortality in older non-severely dependent patients attended for infection. There is not effect in adding Charlson index

    A stream function solver for liquid simulations

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    Food availability and the feeding ecology of ichthyofauna of a Ria Formosa (South Portugal) water reservoir

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    The feeding habits of several fish species in a water reservoir of the Ria Formosa, Portugal, that has similar ecological characteristics to the outside tidal channels, were studied and compared with food availability. The gilthead seabream (Sparus aurata), the most abundant fish species, mainly selected gastropods and bivalves, although occasionally fish and small crustaceans such as tanaids, ostracods, and cumaceans were also selected. Polychaetes, although abundant in the environment, were not particularly selected by any of the fish species studied. The diets of all the species studied were characterized by a large variety of prey, allowing them to survive in environments of low diversity and poor stability, such as coastal lagoons. These fish are largely benthic feeders, essentially eating the epimacroinvertebrates and endomacroinvertebrates and, occasionally, fish. Diplodus vulgaris and Diplodus annularis preferentially selected gastropods and small crustaceans. Spondyliosoma cantharus generally preyed on crustaceans, including the highly mobile epifauna, the mysids, and decapods. Halobatrachus didactylus and Anguilla anguilla, had very diversified diets that included fish. Mullus barbatus were found to have selected all groups of crustaceans and also bivalves. Wrasses, gobies, and Diplodus sargus, all small-sized fish, singled out small crustaceans, gastropods, and bivalves. The Sparids were the least specialized predators, with broader niches than the other species. They preferentially selected molluscs, which were abundant in the environment. A large overlap of diets was observed and competition may be important when fish biomass is high
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