283 research outputs found

    Inertial Motions of a Rigid Body with a cavity filled with a viscous liquid

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    We study inertial motions of the coupled system, S, constituted by a rigid body containing a cavity that is completely filled with a viscous liquid. We show that for data of arbitrary size (initial kinetic energy and total angular momentum) every weak solution (a la Leray-Hopf) converges, as time goes to infinity, to a uniform rotation, thus proving a famous "conjecture" of Zhukovskii. Moreover we show that, in a wide range of initial data, this rotation must occur along the central axis of inertia of S that has the largest moment of inertia. Furthermore, necessary and sufficient conditions for the rigorous nonlinear stability of permanent rotations are provided, which improve and/or generalize results previously given by other authors under different types of approximation of the original equations and/or suitable symmetry assumptions on the shape of the cavity. Finally, we present a number of results obtained by a targeted numerical simulation that, on the one hand, complement the analytical findings, whereas, on the other hand, point out new features that the analysis is yet not able to catch, and, as such, lay the foundation for interesting and challenging future investigation.Comment: Some of the main results proved in this paper were previously announced in Comptes Rendus Mecanique, Vol. 341, 760--765 (2013

    Conceptual and methodological challenges for neuroimaging studies of autistic spectrum disorders

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    Autistic Spectrum Disorders (ASDs) are a set of complex developmental disabilities defined by impairment in social interaction and communication, as well as by restricted interests or repetitive behaviors. Neuroimaging studies have substantially advanced our understanding of the neural mechanisms that underlie the core symptoms of ASDs. Nevertheless, a number of challenges still remain in the application of neuroimaging techniques to the study of ASDs. We review three major conceptual and methodological challenges that complicate the interpretation of findings from neuroimaging studies in ASDs, and that future imaging studies should address through improved designs. These include: (1) identification and implementation of tasks that more specifically target the neural processes of interest, while avoiding the confusion that the symptoms of ASD may impose on both the performance of the task and the detection of brain activations; (2) the inconsistency that disease heterogeneity in persons with ASD can generate on research findings, particularly heterogeneity of symptoms, symptom severity, differences in IQ, total brain volume, and psychiatric comorbidity; and (3) the problems with interpretation of findings from cross-sectional studies of persons with ASD across differing age groups. Failure to address these challenges will continue to hinder our ability to distinguish findings that outline the causes of ASDs from brain processes that represent downstream or compensatory responses to the presence of the disease. Here we propose strategies to address these issues: 1) the use of simple and elementary tasks, that are easier to understand for autistic subjects; 2) the scanning of a more homogenous group of persons with ASDs, preferably at younger age; 3) the performance of longitudinal studies, that may provide more straight forward and reliable results. We believe that this would allow for a better understanding of both the central pathogenic processes and the compensatory responses in the brain of persons suffering from ASDs

    The challenge of improving evidence-based therapy adherence in the secondary prevention of coronary artery disease: the next frontier of cardiac rehabilitation

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    Non-adherence to prescribed drug regimens is an increasing medical problem affecting physicians and patients and contribute to negative outcomes, such as the increased risk of subsequent cardiovascular events. Analysis of various patient populations shows that the choice of drug, its tolerability and the duration of treatment influence the non-adherence. Intervention is required toward patients and health-care providers to improve medication adherence. This review deals about the prevalence of non-adherence to therapy after medical and surgical cardiac event, the risk factors affecting non-adherence and the strategies to implement it. Interventions that may successfully improve adherence should include improved physician compliance with guidelines, patient education and patient reminders, frequent visits or telephone calls from staff, simplification of the patient's drug regimen by reducing the number of pills and daily doses. Since single interventions do not appear efficaceous, it is necessary to establish multiple interventions simultaneously addressing a number of barriers to adherence

    Socioeconomic Status in Adulthood of Children With and Without a history of seizures: A Retrospective Cohort Study

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    Objective: Compare adulthood socioeconomic status for children with and without a history of seizures.Methods: Retrospective cohort study using Aberdeen Children of the Nineteen Fifties (ACONF) data comprising children born 1950-1956 attending primary school 1962-1964, with follow-up data collected in 2001. Adulthood socioeconomic status was based on registrar general measure of occupational social class and categorised as high or low. We adjusted for potentially confounding variables including childhood socioeconomic status, behavioural issues (Rutter A/B scores), biological sex, school test scores, educational attainment, parental engagement with education, peer-status in school, and alcohol use in adulthood. A multivariate binary logistic regression was performed to estimate the adjusted association between children with a history of seizures of any type (for example febrile seizures, or provoked seizures of any other etiology or seizures in the context of epilepsy) or severity and adult socioeconomic status. Multiple imputation using the Monte-Carlo-Markov-Chain method accounted for missing data. Results: Pooled estimates (N=2,208) comparing children with a history of seizures (n=81) and children without a history of seizures (n=2,127) found no differences between these cohorts in terms of adulthood socioeconomic status in both unadjusted (Odds Ratio (OR) 1.45 [95% CI 0.71-2.96], p=0.31) and adjusted (1.02 [0.46, 2.24], p=0.96) analyses. Compared to males, females were at increased odds of having a lower socioeconomic status in adulthood (1.56 [1.13-2.17], p=0.01).Compared to those with low educational attainment, those with moderate (0.32 [0.21, 0.48], p&lt;0.001) and high (0.12 [0.07, 0.20], p&lt;0.001) educational attainment were at reduced odds of having a lower socioeconomic status in adulthood. Conclusion: Cognitive problems in childhood (using educational attainment and scores on primary school tests proxy markers for cognition) rather than a history of seizures per se, were associated with lower SES in a population of adults born 1950-56 in Aberdeen. This relationship may be different depending on the time in history and nation/region of study. Given the changes in health, education and social support in the management of children with seizures over time, it would be of interest to investigate outcomes in a contemporary cohort. Such studies should ideally have validated diagnoses of seizures, details on seizure characteristics such as seizure type and severity, and a large sample size using national data. KeywordsEpilepsy, seizures, childhood, socioeconomic status, epidemiology. <br/

    Sex Differences in Autism Spectrum Disorder: Repetitive Behaviors and Adaptive Functioning

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    Sex differences in restricted and repetitive behaviors (RRBs) in individuals with Autism Spectrum Disorder (ASD) have been explored with mixed findings. We aimed to investigate sex differences in RRBs through a specific measure-i.e., the Repetitive Behavior Scale Revised (RBS-R)-in a sample of preschool-age and school-age children with ASD. Additionally, we evaluated if RRBs were differently related to adaptive functioning within the male and the female age groups. A sample of 210 ASD individuals (3-18 years; 145 males, 65 females) underwent an in-depth assessment including a cognitive, adaptive functioning evaluation (i.e., the Adaptive Behavior Assessment System, Second Edition (ABAS-II)) and RRBs assessment (i.e., RBS-R). No significant sex differences on the RBS-R total score or any RBS-R subscale emerged. Within the group of older participants, RRBs were negatively associated with all adaptive skill domains independently from sex and age. Our results suggest a lack of sex differences in RRBs in our sample. Additionally, our findings highlight the possible negative impact of RRBs on adaptive skills in older individuals with autism, emphasizing the need for autistic individuals of both sexes to undergo an early intervention targeting RRBs, in order to improve their adaptive skills

    Comparison of neurodevelopmental, educational and adulthood socioeconomic outcomes in offspring of women with and without epilepsy: A systematic review and meta-analysis

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    Background: Adequate pre-pregnancy counselling and education planning are essential to improve outcomes for offspring of women with epilepsy (OWWE). The current systematic review and meta-analysis aimed to compare outcomes for OWWE and offspring of women without epilepsy (OWWoE). Methods: We conducted a systematic review and meta-analysis. We searched MEDLINE, EMBASE, CINAHL, PsycINFO (database inception-1st January 2023), OpenGrey, GoogleScholar, and hand-searched journals and reference lists of included studies to identify eligible studies. We placed no language restrictions and included observational studies concerning OWWE and OWWoE. We followed the PRIMSA checklist for abstracting data. The Newcastle-Ottawa Scale for risk of bias assessment was conducted independently by two authors with mediation by a third. We report pooled unadjusted odds ratios (OR) or mean differences (MD) with 95% confidence intervals (95CI) from random (I2&gt;50%) or fixed (I2&lt;50%) effects meta-analyses. Outcomes of interest included offspring autism, attention deficit/hyperactive disorder, intellectual disability, epilepsy, developmental disorder, intelligence, educational, and adulthood socioeconomic outcomes. Results: Of 10,928 articles identified, we included 21 in meta-analyses. OWWE had increased odds of autism (2 articles, 4,502,098 offspring) OR [95CI] 1·67 [1·54, 1·82], attention-deficit/hyperactivity disorder (3 articles, 957,581 offspring) 1·59 [1·44, 1·76], intellectual disability (2 articles, 4,501,786 children) 2·37 [2·13, 2·65], having special educational needs (3 articles, 1,308,919 children) 2·60 [1·07, 6·34]. OWWE had worse mean scores for full-scale intelligence (5 articles, 989 children) -6·05 [-10·31, -1·79]. No studies were identified that investigated adulthood socioeconomic outcomes. Conclusions: Increased odds of poor outcomes are higher with greater anti-seizure medication burden including neurodevelopmental and educational outcomes. In fact, these two outcomes seem to be worse in OWWE compared to OWWoE, even if there was no ASM exposure during pregnancy, but further work is needed to take into account potential confounding factors. Key words: Epilepsy, pregnancy, mother, child, outcomes <br/

    Prevalence and clinical predictors of inappropriate direct oral anticoagulant dosage in octagenarians with atrial fibrillation

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    Purpose: Older age is associated with inappropriate dose prescription of direct oral anticoagulants. The aim of our study was to describe the prevalence and the clinical predictors of inappropriate DOACs dosage among octogenarians in real-world setting. Methods: Data for this study were sourced from the multicenter prospectively maintained Atrial Fibrillation (AF) Research Database (NCT03760874). Of the AF patients aged ≥ 80 who received DOACs treatment, 253 patients were selected. Participants were categorized as appropriate dosage, overdosage, or underdosage. Underdosage and overdosage were, respectively, defined as administration of a lower or higher DOAC dose than recommended in the EHRA consensus. Results: A total of 178 patients (71%) received appropriate DOACs dose and 75 patients (29%) inappropriate DOACs dose; among them, 19 patients (25.6%) were overdosed and 56 (74.4%) were underdosed. Subgroup analysis demonstrated that underdosage was independently associated with male gender [OR = 3.15 (95% IC; 1.45–6.83); p < 0.001], coronary artery disease [OR = 3.60 (95% IC 1.45–9.10); p < 0.001] and body mass index [OR = 1.27 (1.14–1.41); p < 0.001]. Overdosage was independently associated with diabetes mellitus [OR = 18 (3.36–96); p < 0.001], with age [OR = 0.76 (95% IC; 0.61–0.96; p = 0.045], BMI [OR = 0.77 (95% IC; 0.62–0.97; p = 0.043] and with previous bleedings [OR = 6.40 (0.7; 1.43–28); p = 0.039]. There wasn’t significant difference in thromboembolic, major bleeding events and mortality among different subgroups. Underdosage group showed a significatively lower survival compared with appropriate dose group (p < 0.001). Conclusion: In our analysis, nearly one-third of octogenarians with AF received an inappropriate dose of DOAC. Several clinical factors were associated with DOACs’ overdosage (diabetes mellitus type II, previous bleeding) or underdosage (male gender, coronary artery disease, and higher body mass index). Octogenarians with inappropriate DOACs underdosage showed less survival

    The tumor suppressor semaphorin 3B triggers a prometastatic program mediated by interleukin 8 and the tumor microenvironment

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    Semaphorins are a large family of evolutionarily conserved morphogenetic molecules originally identified for their repelling role in axonal guidance. Intriguingly, semaphorins have recently been implicated in cancer progression (Neufeld, G., T. Lange, A. Varshavsky, and O. Kessler. 2007. Adv. Exp. Med. Biol. 600:118–131). In particular, semaphorin 3B (SEMA3B) is considered a putative tumor suppressor, and yet we found that it is expressed at high levels in many invasive and metastatic human cancers. By investigating experimental tumor models, we confirmed that SEMA3B expression inhibited tumor growth, whereas metastatic dissemination was surprisingly increased. We found that SEMA3B induced the production of interleukin (IL) 8 by tumor cells by activating the p38–mitogen-activated protein kinase pathway in a neuropilin 1–dependent manner. Silencing the expression of endogenous SEMA3B in tumor cells impaired IL-8 transcription. The release of IL-8, in turn, induced the recruitment of tumor-associated macrophages and metastatic dissemination to the lung, which could be rescued by blocking IL-8 with neutralizing antibodies. In conclusion, we report that SEMA3B exerts unexpected functions in cancer progression by fostering a prometastatic environment through elevated IL-8 secretion and recruitment of macrophages coupled to the suppression of tumor growth
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