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We consider the problem of generating optimal stochastic policies for Constrained Stochastic Shortest Path problems, which are a natural model for planning under uncertainty for resource-bounded agents with multiple competing objectives. While unconstrained SSPs enjoy a multitude of efficient heuristic search solution methods with the ability to focus on promising areas reachable from the initial state, the state of the art for constrained SSPs revolves around linear and dynamic programming algorithms which explore the entire state space. In this paper, we present i-dual, which, to the best of our knowledge, is the first heuristic search algorithm for constrained SSPs. To concisely represent constraints and efficiently decide their violation, i-dual operates in the space of dual variables describing the policy occupation measures. It does so while retaining the ability to use standard value function heuristics computed by well-known methods. Our experiments on a suite of PPDDL problems augmented with constraints show that these features enable i-dual to achieve up to two orders of magnitude improvement in run-time and memory over linear programming algorithms.

Introduction Education, and less frequently occupation, has been associated with lower dementia risk in studies from high‐income countries. We aimed to investigate the association of cognitive impairment with education and occupation in a low‐middle‐income country sample. Methods In this cross‐sectional study, cognitive function was assessed by the Clinical Dementia Rating sum of boxes (CDR‐SOB). We investigated the association of occupation complexity and education with CDR‐SOB using adjusted linear regression models for age, sex, and neuropathological lesions. Results In 1023 participants, 77% had < 5 years of education, and 56% unskilled occupations. Compared to the group without education, those with formal education had lower CDR‐SOB (1–4 years: β$\beta \;$= ‐0.99, 95% confidence interval [CI] = –1.85; –0.14, P = .02; ≥5 years: β$\beta \;$= –1.42, 95% CI = –2.47; –0.38, P = .008). Occupation complexity and demands were unrelated to cognition. Discussion Education, but not occupation, was related to better cognitive abilities independent of the presence of neuropathological insults.

Inspired by risk-sensitive, robust scheduling for planetary rovers under temporal uncertainty, this work introduces the Probabilistic Simple Temporal Network with Uncertainty (PSTNU), a temporal planning formalism that unifies the set-bounded and probabilistic temporal uncertainty models from the STNU and PSTN literature. By allowing any combination of these two types of uncertainty models, PSTNU's can more appropriately reflect the varying levels of knowledge that a mission operator might have regarding the stochastic duration models of different activities. We also introduce PARIS, a novel sound and provably polynomial-time algorithm for risk-sensitive strong scheduling of PSTNU's. Due to its fully linear problem encoding for typical temporal uncertainty models, PARIS is shown to outperform the current fastest algorithm for risk-sensitive strong PSTN scheduling by nearly four orders of magnitude in some instances of a popular probabilistic scheduling dataset, while results on a new PSTNU scheduling dataset indicate that PARIS is, indeed, amenable for deployment on resource-constrained hardware.

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-Objective: to present the magnetic resonance (Mr) imaging findings of 78 patients with meningiomas diagnosed in a single institution. Method: 78 patients with histological proven intracranial meningioma were studied. there were 52 female and 26 male patients (median=56 years). All Mr imaging examinations were performed with 1.5-t Mr imaging unit with standard protocol. the images were studied by two neuroradiologists, who reached the decisions regarding the findings by consensus. Results: Most of the tumors showed low signal on t1-(60%) and high signl on t2-(68%) and FLAIr (69%) weighted images. Also, the lesions showed heterogeneous signal on t1 (60%), t2 (68%) and FLAIr (64%) sequences. After contrast administration, 83% (n=65) of the tumors presented acentuated and 17% (n=13) showed moderate enhancement. the tumors were located in the frontal lobe in 44% of the cases, in the parietal lobe in 35%, the occipital lobe in 19% and the temporal lobe in 12% of the patients. Areas of vasogenic edema around the tumors were seen in 90% of the cases. twenty six per cent of the cases showed bone infiltration, and the dural tail sign was seen in 59% of the tumors. Conclusion: Intracranial meningiomas usually show heterogeneous low signal on t1-and high signal on t2-weighted and FLAIr images, with intense enhancement after contrast administration. the frontal and parietal lobes are commonly affected. In addition, brain edema, dural tail sign and bone infiltration are the most frequent associated findings.Key words: meningioma, magnetic resonance imaging, brain tumors. meningiomas intracranianos: achados de ressonância magnética em 78 casos resuMo -Objetivo: Apresentar os achados de ressonância magnética (rM) de 78 pacientes com meningioma intracraniano diagnosticados numa única instituição. Método: 78 pacientes com diagnóstico histológico de meningioma intracraniano foram estudados. cinqüenta e dois eram femininos e 26 masculinos (mediana=56 anos). todos os exames de rM foram realizados num aparelho de 1.5 tesla, com protocolo padrão. As imagens foram avaliadas por dois neurorradiologistas, os quais estabeleceram os achados por consenso. Resultados: A maioria dos tumores apresentou baixo sinal em t1 (60%) e alto sinal em t2 (68%) e FLAIr (69%). Além disso, as lesões demonstraram sinal heterogêneo em t1 (60%), t2 (68%) e FLAIr (64%). Após a administração intravenosa de contraste, 83% dos tumores apresentaram realce acentuado e 17% moderado. os tumores estavam localizados no lobo frontal em 44% dos casos, no parietal em 35%, no occipital em 19% e no lobo temporal em 12% dos casos. Áreas de edema vasogênico foram observadas em 90% dos pacientes. Vinte e seis por cento dos casos apresentaram sinais de infiltração ós-sea e o sinal da cauda dural foi visto em 59% dos tumores. Conclusão: Meningiomas intracranianos em geral apresentam sinal heterogêneo, baixo em t1 e alto em t2 e FLAIr, com intenso realce pelo contraste. os lobos frontais e parietais são com freqüência acometidos. Além disso, edema vasogênico, sinal da c...

Objetivos: Edema peritumoral (EP) está presente em 60% dos meningiomas intracranianos. Ao contrário dos tumores intra-axiais, cuja fisiopatologia do edema é creditada a uma desordem da barreira hêmato-encefálica, o real mecanismo de formação do edema perilesional nos meningiomas aindaé desconhecido. Revisar as teorias de formação do EP, assim como suas diversas características são os objetivos deste artigo. Métodos: Os autores discutem, através de revisão de literatura, a associação do EP em meningiomas com fatores clínicos, radiológicos, cirúrgicos, histopatológicos e com recorrência tumoral. Resultados: Vários fatores causais têm sido discutidos nosdiversos artigos, como a quebra da barreira hêmato-encefálica, compressão mecânica e vascular, a secreção de fatores produtores de edema, relacionado a hipoplasia de veias de drenagem e ao padrão de vascularização pial.Conclusão: A causa da formação de edema peritumoral em meningiomas é provavelmente multifatorial e pode estar associada a um maior potencial invasivo do tumor. O seu estudo aprofundado poderá trazer dados adicionais para o esclarecimento dos mecanismos de formação dos meningiomas e deseu comportamento biológico levando ao melhor manejo clínico dos pacientes.