252 research outputs found

    NASA Perspective and Modeling of Thermal Runaway Propagation Mitigation in Aerospace Batteries

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    NASA has traditionally sought to reduce the likelihood of a single cell thermal runaway (TR) in their aerospace batteries to an absolute minimum by employing rigorous screening program of the cells. There was generally a belief that TR propagation resulting in catastrophic failure of the battery was a forgone conclusion for densely packed aerospace lithium-ion batteries. As it turns out, this may not be the case. An increasing number of purportedly TR propagation-resistant batteries are appearing among NASA partners in the commercial sector and the Department of Defense. In the recent update of the battery safety standard (JSC 20793) to address this paradigm shift, the NASA community included requirements for assessing TR severity and identifying simple, low-cost severity reduction measures. Unfortunately, there are no best-practice guidelines for this work in the Agency, so the first project team attempting to meet these requirements would have an undue burden placed upon them. A NASA engineering Safety Center (NESC) team set out to perform pathfinding activities for meeting those requirements. This presentation will provide contextual background to this effort, as well as initial results in attempting to model and simulate TR heat transfer and propagation within battery designs

    Maternal Parenting Stress and Preschoolers’ Social-Emotional Competence and Behavioural Difficulties: A Variable- and Person-Centred Approach

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    Background: The present study examined the relations between maternal parenting stress and preschoolers’ psychosocial adjustment, using both a variable-centred and a person-centred approach. Methods: The study had three main purposes: (a) evaluating the associations of maternal parenting stress with children’s social-emotional competence and behavioural difficulties, as perceived by their mothers; (b) inquiring the existence of different children’s clusters based on their level of social-emotional competence and behavioural difficulties; (c) exploring differences in maternal parenting stress linked to cluster membership. Participants were 91 Italian mothers, aged from 22 to 47 years old (M = 35.14, SD = 5.80), having a preschool child from 3 to 6 years old (M = 4.6, SD = 0.80). Results: Overall, results showed that maternal parenting stress was negatively associated with children’s social-emotional competence, and positively associated with their behavioural difficulties. A cluster analysis allowed identifying four children’s profiles characterized by different levels of social-emotional competence and behavioural difficulties: Maladjusted, Troubled, Adjusted and Controversial. Conclusions: Results also evidenced differences among clusters in maternal parenting stress. Ultimately, this study suggests that interventions may consider reducing maternal parenting stress to promote children’s psychosocial adjustment

    Large-scale automated identification of mouse brain cells in confocal light sheet microscopy images

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    Motivation: Recently, confocal light sheet microscopy has enabled high-throughput acquisition of whole mouse brain 3D images at the micron scale resolution. This poses the unprecedented challenge of creating accurate digital maps of the whole set of cells in a brain. Results: We introduce a fast and scalable algorithm for fully automated cell identification. We obtained the whole digital map of Purkinje cells in mouse cerebellum consisting of a set of 3D cell center coordinates. The method is accurate and we estimated an F(1) measure of 0.96 using 56 representative volumes, totaling 1.09 GVoxel and containing 4138 manually annotated soma centers. Availability and implementation: Source code and its documentation are available at http://bcfind.dinfo.unifi.it/. The whole pipeline of methods is implemented in Python and makes use of Pylearn2 and modified parts of Scikit-learn. Brain images are available on request. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online

    Signatures of Extreme Longevity: A Perspective from Bivalve Molecular Evolution

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    Among Metazoa, bivalves have the highest lifespan disparity, ranging from 1 to 500+ years, making them an exceptional testing ground to understand mechanisms underlying aging and the evolution of extended longevity. Nevertheless, comparative molecular evolution has been an overlooked approach in this instance. Here, we leveraged transcriptomic resources spanning 30 bivalve species to unravel the signatures of convergent molecular evolution in four long-lived species: Margaritifera margaritifera, Elliptio complanata, Lampsilis siliquoidea, and Arctica islandica (the latter represents the longest-lived noncolonial metazoan known so far). We applied a comprehensive approach-which included inference of convergent dN/dS, convergent positive selection, and convergent amino acid substitution-with a strong focus on the reduction of false positives. Genes with convergent evolution in long-lived bivalves show more physical and functional interactions to each other than expected, suggesting that they are biologically connected; this interaction network is enriched in genes for which a role in longevity has been experimentally supported in other species. This suggests that genes in the network are involved in extended longevity in bivalves and, consequently, that the mechanisms underlying extended longevity are-at least partially-shared across Metazoa. Although we believe that an integration of different genes and pathways is required for the extended longevity phenotype, we highlight the potential central roles of genes involved in cell proliferation control, translational machinery, and response to hypoxia, in lifespan extension

    A Noninvasive Test for Vesico-Ureteric Reflux in Children

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    Objective To report the development and testing of a device for the noninvasive diagnosis of vesico‐ureteric reflux (VUR) which avoids the need for urethral catheterization (currently required to reliably determine the presence of VUR), and which thus avoids the anxiety of parents and patients that causes many families to refuse such evaluation. Patients and methods Fifty‐four children (49 girls and five boys, mean age 7.2 years, range 4–14) previously evaluated as having VUR volunteered to participate; no child was symptomatic at the time of the study. Refluxing units were known to be present by voiding cysto‐urethrography (within 1 year, mean 7 months) in 45 and absent in 16. The device developed acquires electronically processed acoustic signals from the child during an observed urination. The signals are then analysed ‘off‐line’ to determine the presence or absence of VUR. The initial preparation for the test included: (i) a full bladder [at least 0.80 × {(2+age) ×30 mL}] measured by ultrasonography; and (ii) localization of the pelvi‐ureteric junction by ultrasonography to accurately place the device\u27s sensors on the child\u27s back. The children were then positioned at a commode after placing the sensors; the recording was started and continued until voiding occurred. The children were tested with the recording and analysis team unaware of the presence and/or degree of VUR. The first 47 studies were single‐kidney examinations and the remaining seven included simultaneous monitoring of both kidneys. Results Sixty‐one renal units were assessed and interpretable signals were obtained from 54 (89%). There were seven episodes of ‘system failure’ when no interpretable data were obtained. One unit with no VUR had a ‘reflux’ signal; in four kidneys, spontaneous (two) and postsurgical (two) resolution of reflux was predicted by the testing and subsequently verified by cyclic radionuclide cystography. Conclusions This noninvasive diagnostic technique detected VUR in 35 of 37 refluxing units and verified no reflux in 16 of 17 units without VUR. Further refinements may allow this technology to be used in all children with suspected VUR

    Novel insights on intake of fish and prevention of sarcopenia: All reasons for an adequate consumption

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    Sarcopenia is defined as a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength and it is diagnosed by measurements of muscle mass, muscle strength, and physical performance. Sarcopenia affects quality of life and is associated with several adverse health effects. Muscle decline is aggravated by a sedentary lifestyle and can be prevented through proper nutrition, together with adequate physical activity. Fish contains biologically active compounds, such as omega-3 polyunsaturated fatty acids, proteins, vitamin D, magnesium, and carnitine, which are able to intervene positively on muscle metabolism. This narrative literature review was performed to evaluate evidence regarding the actual benefit of fish consumption in the prevention of sarcopenia and the positive action on the muscle mass of the biological compounds present in fish. The results demonstrated that fish consumption has a protective and anti-inflammatory function on skeletal muscle and that its biologically active compounds help to maintain good muscle performance, preventing sarcopenia. Considering the nutritional and health benefits, elderly with sarcopenia should consume at least three servings per week of fish in order to have a minimum intake of 4–4.59 g daily of omega 3, and reaching the 50% RDA in Vitamin E and D. High biological value of proteins in 150 g of fish and its high available magnesium (20% of RDA in 150 g of fish) are an added value that could suggest fish as a “functional food” in order to prevent and treat sarcopenia

    Demethylation of the Coding Region Triggers the Activation of the Human Testis-Specific PDHA2 Gene in Somatic Tissues

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    Human PDHA2 is a testis-specific gene that codes for the E1α subunit of Pyruvate Dehydrogenase Complex (PDC), a crucial enzyme system in cell energy metabolism. Since activation of the PDHA2 gene in somatic cells could be a new therapeutic approach for PDC deficiency, we aimed to identify the regulatory mechanisms underlying the human PDHA2 gene expression. Functional deletion studies revealed that the −122 to −6 promoter region is indispensable for basal expression of this TATA-less promoter, and suggested a role of an epigenetic program in the control of PDHA2 gene expression. Indeed, treatment of SH-SY5Y cells with the hypomethylating agent 5-Aza-2â€Č-deoxycytidine (DAC) promoted the reactivation of the PDHA2 gene, by inducing the recruitment of the RNA polymerase II to the proximal promoter region and the consequent increase in PDHA2 mRNA levels. Bisulfite sequencing analysis revealed that DAC treatment induced a significant demethylation of the CpG island II (nucleotides +197 to +460) in PDHA2 coding region, while the promoter region remained highly methylated. Taken together with our previous results that show an in vivo correlation between PDHA2 expression and the demethylation of the CpG island II in testis germ cells, the present results show that internal methylation of the PDHA2 gene plays a part in its repression in somatic cells. In conclusion, our data support the novel finding that methylation of the PDHA2 coding region can inhibit gene transcription. This represents a key mechanism for absence of PDHA2 expression in somatic cells and a target for PDC therapy

    A structural equation model to assess the pathways of body adiposity and inflammation status on dysmetabolic biomarkers via red cell distribution width and mean corpuscular volume: a cross-sectional study in overweight and obese subjects

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    Background A study has been performed in overweight and obese subjects to assess the effects of adiposity and inflammation indicators on dysmetabolic biomarkers via red cell distribution width (RDW) and mean corpuscular volume (MCV), taking into account pro-antioxidant balance. Methods Data from 166 overweight subjects were analyzed by a path analysis model using structural equation modelling (SEM) to evaluate the direct and indirect pathway effects of adiposity, measured by body mass index (BMI) and waist circumference (WC), and inflammation status, measured by pro-antioxidant balance [reactive oxygen species (ROS)], lag-time and slope and C-reactive protein (CRP) values on dysmetabolic biomarkers, via RDW and MCV. Results BMI was strongly linked to CRP and ROS levels. Moreover, there was a significant negative decrease of MCV (1.546 femtoliters) linked to BMI indirectly via high CRP levels. Furthermore, WC affected RDW, indicating a possible mediatory role for RDW in relation to the relationship between WC and homeostatic model assessment (HOMA), insulin and high density lipoprotein (HDL), respectively. This was evident by the elevated HOMA and insulin levels and the decreased levels of HDL. Finally, ROS-related markers did not affect directly RDW and MCV. Conclusion The reported outcomes suggest that RDW might play a mediatory role in the relationship between WC and the dysmetabolic outcomes in overweight and obese individuals. CRP seems to modulate the linkage between BMI and MCV. This study provides the backbone structure for future scenarios and lays the foundation for further research on the role of RDW and MCV as suitable biomarkers for the assessment of cardiovascular disease (HDL-cholesterol), inflammatory bowels and insulin resistance

    Can we increase children’s rights endorsement and knowledge?: A pilot study based on the reference framework of competences for democratic culture

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    This pilot study is the first to examine whether a novel curriculum based on the Reference Framework of Competences for Democratic Culture (RFCDC) could increase children’s endorsement and knowledge of children’s rights. We conducted a pre-test-post-test design with an intervention and a comparison school. Pupils (n = 172) from Bulgaria, Italy, Norway, Romania, and Spain attended schools in which the curriculum was taught, whereas pupils in the comparison group (n = 120) attended schools in the same city where the curriculum was not taught. Both groups were tested on their endorsement and knowledge of rights before and at the end of the intervention. Children in the intervention group increased in endorsing children’s rights at post-test more than did children in the intervention group. Most children believed that children had rights. Children in the intervention group showed modest increases in their knowledge of rights. Future ways of implementing the RFCDC are suggested.publishedVersio

    A Forward Genetic Screen Reveals Novel Independent Regulators of Ulbp1, an Activating Ligand for Natural Killer Cells

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    Recognition and elimination of tumor cells by the immune system is crucial for limiting tumor growth. Natural killer (NK) cells become activated when the receptor NKG2D is engaged by ligands that are frequently upregulated in primary tumors and on cancer cell lines. However, the molecular mechanisms driving NKG2D ligand expression on tumor cells are not well defined. Using a forward genetic screen in a tumor-derived human cell line, we identified several novel factors supporting expression of the NKG2D ligand ULBP1. Our results show stepwise contributions of independent pathways working at multiple stages of ULBP1 biogenesis. Deeper investigation of selected hits from the screen showed that the transcription factor ATF4 drives ULBP1 gene expression in cancer cell lines, while the RNA-binding protein RBM4 supports ULBP1 expression by suppressing a novel alternatively spliced isoform of ULBP1 mRNA. These findings offer insight into the stress pathways that alert the immune system to danger
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