424 research outputs found

    Kuznetsov independence for interval-valued expectations and sets of probability distributions: Properties and algorithms

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    Kuznetsov independence of variables X and Y means that, for any pair of bounded functions f(X)f(X) and g(Y)g(Y), E[f(X)g(Y)]=E[f(X)]⊠E[g(Y)]E[f(X)g(Y)]=E[f(X)]⊠E[g(Y)], where E[⋅]E[⋅] denotes interval-valued expectation and ⊠ denotes interval multiplication. We present properties of Kuznetsov independence for several variables, and connect it with other concepts of independence in the literature; in particular we show that strong extensions are always included in sets of probability distributions whose lower and upper expectations satisfy Kuznetsov independence. We introduce an algorithm that computes lower expectations subject to judgments of Kuznetsov independence by mixing column generation techniques with nonlinear programming. Finally, we define a concept of conditional Kuznetsov independence, and study its graphoid properties.ThefirstauthorhasbeenpartiallysupportedbyCNPq,andthisworkhasbeensupportedbyFAPESPthroughgrant04/09568-0.ThesecondauthorhasbeenpartiallysupportedbytheHaslerFoundationgrantno.10030

    Effects of different combinations of concentric and eccentric resistance training programs on traditional and alternative hamstrings-to-quadriceps ratios

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    Resistance training is often recommended for combined increases in traditional and alternative hamstrings-to-quadriceps (H:Q) ratios in order to reduce knee strength imbalance and associated hamstrings and knee ligament injury risk. The aim of this study was to investigate the effect of different concentric and eccentric resistance training programs on traditional and alternative H:Q ratios. Forty male volunteers were assigned to one of 4 groups: concentric quadriceps and concentric hamstrings (CON/CON, n = 10), eccentric quadriceps and eccentric hamstrings (ECC/ECC, n = 10), concentric quadriceps and eccentric hamstrings (CON/ECC, n = 10), or no training (control (CNTRL), n = 10). Traditional conventional (CR) and functional (FR), alternative rate of torque development (RTD), muscle size (MS), and muscle activation (MA) H:Q ratios were measured before and after six weeks of unilateral nondominant knee extension–flexion resistance training performed on an isokinetic dynamometer. The ECC/ECC training significantly increased FR (pre = 0.75 ± 0.11; post = 0.85 ± 0.15), whereas the lack of training (CNTRL) decreased the RTD H:Q ratio (pre = 1.10 ± 0.67; post = 0.73 ± 0.33). There were no differences between groups for the other traditional and alternative ratios following resistance training protocols. These findings suggest eccentric exercise for quadriceps and hamstrings as the most beneficial training program for inducing increases in the traditional FR. However, different resistance training strategies may be needed to also elicit increases in the alternative RTD, MS, and MA H:Q ratios for fully restoring muscle balance and reducing potential hamstrings and knee ligament injury risk

    Voxel-based investigations of regional cerebral blood flow abnormalities in Alzheimer's disease using a single-detector SPECT system

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    PURPOSE: To evaluate the feasibility of using the Statistical Parametric Mapping (SPM) program for an automated, voxel-by-voxel assessment of regional cerebral blood flow (rCBF) deficits in Alzheimer's disease (AD) subjects relative to age-matched controls studied with a conventional, single-detector SPECT system. METHODS: We used a databank of 99mTc-HMPAO images of 19 patients with a diagnosis of probable AD and 15 elderly healthy volunteers; data were acquired using an Orbiter-Siemens single-detector SPECT system. Using SPM, images were transformed spatially, smoothed (12mm), and the data were compared on a voxel-by-voxel basis with t-tests. RESULTS: There were significant rCBF reductions in AD patients relative to controls involving regions predicted a priori to be affected in AD, namely the left temporal and parietal neocortices, and the right posterior cingulate gyrus (pOBJETIVO: Avaliar a viabilidade de emprego do programa Statistical Parametric Mapping (SPM) para investigar de forma automatizada, voxel-a-voxel, a presença de dĂ©ficits de fluxo sanguĂ­neo cerebral regional (FSCr) em pacientes com doença de Alzheimer (DA) comparados a sujeitos-controle pareados para idade, usando imagens de SPECT adquiridas com um equipamento convencional de detector Ășnico. MÉTODOS: Foi utilizado um banco de imagens adquiridas apĂłs injeção de 99mTc-HMPAO em 19 pacientes com diagnĂłstico provĂĄvel de DA e 15 voluntĂĄrios idosos saudĂĄveis, usando um equipamento de SPECT Orbiter-Siemens de detector Ășnico. Empregando o programa SPM, as imagens foram transformadas espacialmente, suavizadas (12mm FWHM), e comparadas estatisticamente voxel-a-voxel entre os dois grupos, usando o teste de T. RESULTADOS: Foram identificadas reduçÔes significativas de FSCr nos pacientes com DA comparados aos controles em regiĂ”es previstas a priori como afetadas por esta forma de demĂȘncia, quais sejam os neocĂłrtices temporal e parietal em hemisfĂ©rio esquerdo e o cĂ­ngulo posterior direito (p<0,05, corrigido para comparaçÔes mĂșltiplas). DISCUSSÃO: A localização dos focos de redução de FSCr em pacientes com DA no nosso estudo Ă©, de forma geral, consistente com os achados de dĂ©ficits cerebrais detectados em estudos anteriores de neuroimagem funcional na DA realizados com equipamentos de resolução espacial mais alta. Isto sugere o potencial de utilidade do programa SPM para a anĂĄlise de dados de SPECT adquiridos com equipamentos de detector Ășnico, apesar da sensibilidade e resolução espacial limitadas de tais aparelhos

    Voxel-based investigations of regional cerebral blood flow abnormalities in Alzheimer's disease using a single-detector SPECT system

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    PURPOSE: To evaluate the feasibility of using the Statistical Parametric Mapping (SPM) program for an automated, voxel-by-voxel assessment of regional cerebral blood flow (rCBF) deficits in Alzheimer's disease (AD) subjects relative to age-matched controls studied with a conventional, single-detector SPECT system. METHODS: We used a databank of 99mTc-HMPAO images of 19 patients with a diagnosis of probable AD and 15 elderly healthy volunteers; data were acquired using an Orbiter-Siemens single-detector SPECT system. Using SPM, images were transformed spatially, smoothed (12mm), and the data were compared on a voxel-by-voxel basis with t-tests. RESULTS: There were significant rCBF reductions in AD patients relative to controls involving regions predicted a priori to be affected in AD, namely the left temporal and parietal neocortices, and the right posterior cingulate gyrus (pOBJETIVO: Avaliar a viabilidade de emprego do programa Statistical Parametric Mapping (SPM) para investigar de forma automatizada, voxel-a-voxel, a presença de dĂ©ficits de fluxo sanguĂ­neo cerebral regional (FSCr) em pacientes com doença de Alzheimer (DA) comparados a sujeitos-controle pareados para idade, usando imagens de SPECT adquiridas com um equipamento convencional de detector Ășnico. MÉTODOS: Foi utilizado um banco de imagens adquiridas apĂłs injeção de 99mTc-HMPAO em 19 pacientes com diagnĂłstico provĂĄvel de DA e 15 voluntĂĄrios idosos saudĂĄveis, usando um equipamento de SPECT Orbiter-Siemens de detector Ășnico. Empregando o programa SPM, as imagens foram transformadas espacialmente, suavizadas (12mm FWHM), e comparadas estatisticamente voxel-a-voxel entre os dois grupos, usando o teste de T. RESULTADOS: Foram identificadas reduçÔes significativas de FSCr nos pacientes com DA comparados aos controles em regiĂ”es previstas a priori como afetadas por esta forma de demĂȘncia, quais sejam os neocĂłrtices temporal e parietal em hemisfĂ©rio esquerdo e o cĂ­ngulo posterior direito (

    Auxological and endocrine findings in narcolepsy type 1: seventeen-year follow-up from a pediatric endocrinology center

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    Introduction: Narcolepsy Type 1 (NT1) is a rare hypersomnia of central origin linked to hypocretin deficiency, most frequently arising at pediatric age. NT1 could be associated with endocrine comorbidities involving the neuroendocrine axis, predominantly obesity, and Central Precocious Puberty (CPP). The primary aim of this study is the evaluation of endocrine and auxological parameters at diagnosis and during follow-up in patients with NT1, treated with Sodium Oxybate (SO) or not. Methods: We retrospectively evaluated the auxological, biochemical, and radiological parameters of 112 patients referred to our Center between 2004-2022. The design of our study is cross-sectional at the time of diagnosis followed by a longitudinal follow-up. Results: Our study confirms an increased frequency of CPP and obesity in patients with NT1. At first evaluation, obesity was found in 31.3% of patients, while overweight was found in 25.0%. A diagnosis of CPP was made in 19.6% of patients. Interestingly, this group showed a significantly lower level of CSF-hypocretin (hrct-1) at diagnosis compared to others. We found an improvement in BMI SDS in the SO-treated group compared to untreated patients, and this trend persisted also at 36 months of follow-up (0.0 ± 1.3 vs 1.3 ± 0.4; p&lt;0.03). Sixty-three patients reached their final height, with a median SDS of 0.6 ± 1.1 in boys and 0.2 ± 1.2 in girls. Discussion: To our knowledge, these are the first results regarding the final height in a large series of pediatric patients with NT1, with a normal range of IGF1-SDS levels and stature SDS

    Child Neurology: A Case Series of Heterogeneous Neuropsychiatric Symptoms and Outcome in Very Early-Onset Narcolepsy Type 1

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    Narcolepsy type 1 is a central disorder of hypersomnolence characterized by excessive daytime sleepiness, cataplexy (i.e., sudden loss of muscle tone during wakefulness triggered by emotions), and REM sleep-related manifestations that can present with a peculiar phenotype when arising at a pediatric age. Several features of childhood-onset narcolepsy type 1 are also common in neuropsychiatric conditions; discrete neuropsychiatric comorbidity has also been demonstrated. Here, we report on 3 children with very early narcolepsy type 1. All 3 patients had psychiatric features at the time of symptom onset coupled with peculiar motor disturbances. The course of narcolepsy symptoms also paralleled neuropsychiatric symptoms, suggesting a possible intrinsic link between sleep and psychological features. Multidisciplinary management is mandatory for pediatric narcolepsy type 1 since prompt disease management addressing neuropsychiatric symptoms could lead to better clinical outcomes and quality of life

    Anomalous origin of the left coronary artery with origin in the right coronary artery from a single coronary ostium associated with multivessel coronary artery disease: case report and literature review

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    The anomalous origin of the coronary arteries is a group of rare congenital heart conditions in which there has been an increase in its diagnosis thanks to more accessible and less invasive imaging techniques such as coronary angiotomography, which allows visualization of the arteries in its entire path in a short exploration interval, with adequate spatial and temporal resolution. The clinical presentation is variable, up to 80% are asymptomatic and the remaining 20% may present arrhythmias, myocardial infarction, heart failure and sudden death. We present the case of a patient with unstable angina in whom an anomalous origin of the left coronary artery (LCA) with origin in the right coronary artery (RCA) from a single coronary ostium associated with multivessel coronary artery disease was diagnosed
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