295 research outputs found

    Fast Neural Network Predictions from Constrained Aerodynamics Datasets

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    Incorporating computational fluid dynamics in the design process of jets, spacecraft, or gas turbine engines is often challenged by the required computational resources and simulation time, which depend on the chosen physics-based computational models and grid resolutions. An ongoing problem in the field is how to simulate these systems faster but with sufficient accuracy. While many approaches involve simplified models of the underlying physics, others are model-free and make predictions based only on existing simulation data. We present a novel model-free approach in which we reformulate the simulation problem to effectively increase the size of constrained pre-computed datasets and introduce a novel neural network architecture (called a cluster network) with an inductive bias well-suited to highly nonlinear computational fluid dynamics solutions. Compared to the state-of-the-art in model-based approximations, we show that our approach is nearly as accurate, an order of magnitude faster, and easier to apply. Furthermore, we show that our method outperforms other model-free approaches

    Exploring the Crosstalk Between LMNA and Splicing Machinery Gene Mutations in Dilated Cardiomyopathy

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    Mutations in the LMNA gene, which encodes for the nuclear lamina proteins lamins A and C, are responsible for a diverse group of diseases known as laminopathies. One type of laminopathy is Dilated Cardiomyopathy (DCM), a heart muscle disease characterized by dilation of the left ventricle and impaired systolic function, often leading to heart failure and sudden cardiac death. LMNA is the second most commonly mutated gene in DCM. In addition to LMNA, mutations in more than 60 genes have been associated with DCM. The DCM-associated genes encode a variety of proteins including transcription factors, cytoskeletal, Ca2+-regulating, ion-channel, desmosomal, sarcomeric, and nuclear-membrane proteins. Another important category among DCM-causing genes emerged upon the identification of DCM-causing mutations in RNA binding motif protein 20 (RBM20), an alternative splicing factor that is chiefly expressed in the heart. In addition to RBM20, several essential splicing factors were validated, by employing mouse knock out models, to be embryonically lethal due to aberrant cardiogenesis. Furthermore, heart-specific deletion of some of these splicing factors was found to result in aberrant splicing of their targets and DCM development. In addition to splicing alterations, advances in next generation sequencing highlighted the association between splice-site mutations in several genes and DCM. This review summarizes LMNA mutations and splicing alterations in DCM and discusses how the interaction between LMNA and splicing regulators could possibly explain DCM disease mechanisms

    Measuring maternal mortality : an overview of opportunities and options for developing countries

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    Background:There is currently an unprecedented expressed need and demand for estimates of maternal mortality in developing countries. This has been stimulated in part by the creation of a Millennium Development Goal that will be judged partly on the basis of reductions in maternal mortality by 2015. Methods: Since the launch of the Safe Motherhood Initiative in 1987, new opportunities for data capture have arisen and new methods have been developed, tested and used. This paper provides a pragmatic overview of these methods and the optimal measurement strategies for different developing country contexts. Results: There are significant recent advances in the measurement of maternal mortality, yet also room for further improvement, particularly in assessing the magnitude and direction of biases and their implications for different data uses. Some of the innovations in measurement provide efficient mechanisms for gathering the requisite primary data at a reasonably low cost. No method, however, has zero costs. Investment is needed in measurement strategies for maternal mortality suited to the needs and resources of a country, and which also strengthen the technical capacity to generate and use credible estimates. Conclusion: Ownership of information is necessary for it to be acted upon: what you count is what you do. Difficulties with measurement must not be allowed to discourage efforts to reduce maternal mortality. Countries must be encouraged and enabled to count maternal deaths and act.WJG is funded partially by the University of Aberdeen. OMRC is partially funded by the London School of Hygiene and Tropical Medicine. CS and SA are partially funded by Johns Hopkins University. CAZ is funded by the Health Metrics Network at the World Health Organization. WJG, OMRC, CS and SA are also partially supported through an international research program, Immpact, funded by the Bill & Melinda Gates Foundation, the Department for International Development, the European Commission and USAID

    Internet-based search of randomised trials relevant to mental health originating in the Arab world

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    BACKGROUND: The internet is becoming a widely used source of accessing medical research through various on-line databases. This instant access to information is of benefit to busy clinicians and service users around the world. The population of the Arab World is comparable to that of the United States, yet it is widely believed to have a greatly contrasting output of randomised controlled trials related to mental health. This study was designed to investigate the existence of such research in the Arab World and also to investigate the availability of this research on-line. METHODS: Survey of findings from three internet-based potential sources of randomised trials originating from the Arab world and relevant to mental health care. RESULTS: A manual search of an Arabic online current contents service identified 3 studies, MEDLINE, EMBASE, and PsycINFO searches identified only 1 study, and a manual search of a specifically indexed, study-based mental health database, PsiTri, revealed 27 trials. CONCLUSION: There genuinely seem to be few trials from the Arab world and accessing these on-line was problematic. Replication of some studies that guide psychiatric/psychological practice in the Arab world would seem prudent

    User Evaluation of Neonatology Ward Design: An Application of Focus Group and Semantic Differential

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    [EN] Objective: The object of this article is to identify the set of affective and emotional factors behind users assessments of a space in a neonatology unit and to propose design guidelines based on these. Background: The importance of the neonatology service and the variety of users place great demands on the space at all levels. Despite the repercussions, the emotional aspects of the environment have received less attention. Methods: To avoid incurring limitations in the user mental scheme, this study uses two complementary methodologies: focus group and semantic differential. The (qualitative) focus group methodology provides exploratory information and concepts. The (quantitative) semantic differential methodology then uses these concepts to extract the conceptual structures that users employ in their assessment of the space. Of the total 175 subjects, 31 took part in focus groups and 144 in semantic differential. Results: Five independent concepts were identified: privacy, functionality and professional nature, spaciousness, lighting, and cleanliness. In relation to the importance of the overall positive assessment of the space, the perception of privacy and sensations of dominance and pleasure are fundamental. Six relevant design aspects were also identified: provide spacious surroundings, facilitate sufficient separation between the different posts or cots, use different colors from those usually found in health-care centers, as some aversion was found to white and especially green, design areas with childhood themes, use warm artificial light, and choose user-friendly equipment. Conclusions: Results provide design recommendations of interest and show the possibilities offered by combining both systems to analyze user response.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Ministerio de Economia y Competitividad, Spain (Project TIN2013-45736-R).Higuera-Trujillo, JL.; Montañana I Aviñó, A.; Llinares Millán, MDC. (2017). User Evaluation of Neonatology Ward Design: An Application of Focus Group and Semantic Differential. HERD Health Environments Research & Design Journal. 10(2):23-48. https://doi.org/10.1177/1937586716641275S234810

    Rapamycin induces glucose intolerance in mice by reducing islet mass, insulin content, and insulin sensitivity

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    Rapamycin, a specific inhibitor for mTOR complex 1, is an FDA-approved immunosuppressant for organ transplant. Recent developments have raised the prospect of using rapamycin to treat cancer or diabetes and to delay aging. It is therefore important to assess how rapamycin treatment affects glucose homeostasis. Here, we show that the same rapamycin treatment reported to extend mouse life span significantly impaired glucose homeostasis of aged mice. Moreover, rapamycin treatment of lean C57B/L6 mice reduced glucose-stimulated insulin secretion in vivo and ex vivo as well as the insulin content and beta cell mass of pancreatic islets. Confounding the diminished capacity for insulin release, rapamycin decreased insulin sensitivity. The multitude of rapamycin effects thus all lead to glucose intolerance. As our findings reveal that chronic rapamycin treatment could be diabetogenic, monitoring glucose homeostasis is crucial when using rapamycin as a therapeutic as well as experimental reagent

    Failure to Modulate Attentional Control in Advanced Aging Linked to White Matter Pathology

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    Advanced aging is associated with reduced attentional control and less flexible information processing. Here, the origins of these cognitive effects were explored using a functional magnetic resonance imaging task that systematically varied demands to shift attention and inhibit irrelevant information across task blocks. Prefrontal and parietal regions previously implicated in attentional control were recruited by the task and most so for the most demanding task configurations. A subset of older individuals did not modulate activity in frontal and parietal regions in response to changing task requirements. Older adults who did not dynamically modulate activity underperformed their peers and scored more poorly on neuropsychological measures of executive function and speed of processing. Examining 2 markers of preclinical pathology in older adults revealed that white matter hyperintensities (WMHs), but not high amyloid burden, were associated with failure to modulate activity in response to changing task demands. In contrast, high amyloid burden was associated with alterations in default network activity. These results suggest failure to modulate frontal and parietal activity reflects a disruptive process in advanced aging associated with specific neuropathologic processes

    Early parenting intervention: Family risk and first-time parenting related to intervention effectiveness

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    The effects of cumulative risk and parity on the effectiveness of a home based parenting intervention were tested in a randomized controlled trial with 237 families with 1- to 3-year-old children screened for high levels of externalizing behavior. The intervention was aimed at enhancing positive parenting and decreasing externalizing behaviors. The results showed that cumulative risk was not associated with either change in child externalizing behaviors or change in positive parenting. When intervention effectiveness was compared for primiparas (i.e., first-time mothers) versus multiparas (i.e., mothers with more than one child), we found that intervention mothers of first-born children displayed an increase in their use of positive discipline strategies as compared to first-time mothers in the control group, whereas a similar effect for multiparas was absent. Among multiparas we found an intervention effect on sensitivity, with control group mothers showing an increase in sensitivity, whereas the intervention group showed a constant level of sensitivity over time. These results suggest that parity may be a moderator of intervention effectiveness. Implications for investigating moderators of intervention effectiveness are discussed. © 2007 Springer Science+Business Media, LLC
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