275 research outputs found

    Risk Management & Innovation

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    Feasibility of a Supporting‐Salt‐Free Nonaqueous Redox Flow Battery Utilizing Ionic Active Materials

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    Nonaqueous redox flow batteries (NAqRFBs) are promising devices for grid‐scale energy storage, but high projected prices could limit commercial prospects. One route to reduced prices is to minimize or eliminate the expensive supporting salts typically employed in NAqRFBs. Herein, the feasibility of a flow cell operating in the absence of supporting salt by utilizing ionic active species is demonstrated. These ionic species have high conductivities in acetonitrile (12–19 mS cm−1) and cycle at 20 mA cm−2 with energy efficiencies (>75 %) comparable to those of state‐of‐the‐art NAqRFBs employing high concentrations of supporting salt. A chemistry‐agnostic techno‐economic analysis highlights the possible cost savings of minimizing salt content in a NAqRFB. This work offers the first demonstration of a NAqRFB operating without supporting salt. The associated design principles can guide the development of future active species and could make NAqRFBs competitive with their aqueous counterparts.Salt‐free cell: Decreasing the contribution of salt costs to the total electrolyte cost for nonaqueous redox flow batteries is essential for economic viability. A nonaqueous flow battery utilizing ionic active materials completely removes the need for a supporting salt. The cell cycling performance and area‐specific specific resistance are comparable to those of state‐of‐the‐art nonaqueous flow cells with high salt concentrations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/1/cssc201700028-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/2/cssc201700028.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137469/3/cssc201700028_am.pd

    Early Identification of Developmental Coordination Disorder: Gender Differences in Performance of the Movement Assessment Battery in Preschool-age Children

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    Developmental coordination disorder (DCD) is a neurodevelopmental disorder often highlighted by a severe lack of motor coordination that interferes with activities of daily living. The prevalence of DCD in children ranges from 2 to 20% in the United States. Early identification and early intervention can help mitigate potential long term negative effects. The movement assessment battery for children (MABC-2) is a commonly used tool used to identify DCD. PURPOSE: This study examined gender differences in performance on the MABC-2 between preschool-age children. METHODS: 45 preschool-age children (26 girls and 19 boys, Mage = 4.0) were assessed using the MABC-2. The MABC-2 is comprised of 8 items across three subdomains (aiming and catching, manual dexterity, and balance). An independent samples t-test was conducted to observe the differences in each of the 3 sub domains of the MABC between boys and girls and by age. RESULTS: Overall, 39 of children were not at-risk for DCD, and 4 children were at-risk for DCD. The results show a significant difference in the balance domain with girls demonstrating more proficiency (p =0.03) than the boys. There were no significant differences found in manual dexterity (p = .76), aiming and catching (p =0.60), and overall test score (p = 0.18). There were no significant differences based on age across any of the domains. CONCLUSION: Early assessment of young children may be important as potential gender differences already exist by preschool-age. Separate norms may be necessary for boys and girls in this age band as several studies have consistently identified gender differences in the MABC-2. Further exploration of why these differences may exist at such an early age should be explored

    The Association between Parent\u27s Perception and Child\u27s Actual Motor Skills in Preschool-age Children

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    The preschool years is a critical time for the optimal development of children\u27s fine and gross motor skills for future engagement in physical activity. Parents play a critical role in the development of these skills and early identification of potential developmental delays in their children. Early identification of developmental delay is essential for early intervention and rely on accurate child screenings that are often administered by parents. Few studies have compared the accuracy of parent’s perceptions across two different measurements with children\u27s actual motor skills. PURPOSE: This study compared parents\u27 perceptions of their child’s motor skills on two assessments with their actual performance on the MABC-2. METHODS: 45 preschool-age children across the metro DFW area participated in this study (26 girls and 19 boys, Mage = 4.0).  IRB approval was obtained for all participants. Children were assessed using the MABC-2. The MABC-2 is comprised of 8 items across three subdomains (aiming and catching, manual dexterity, and balance). Parents completed two separate surveys on the perception of their child\u27s motor skills (Ages and Stages Questionnaire (ASQ), and the Little Developmental Coordination Disorder questionnaire (LDCDQ). The ASQ ask parents to compare their child\u27s abilities against other children within the same age group across five different domains (communication, gross motor, fine motor, personal-social, and problem solving). The LDCDQ ask parents to rate their child’s gross and fine motor abilities across fifteen different items. Bivariate correlations were used to analyze the relationship between parent responses and children’s scores on the MABC-2. RESULTS: On the LDCDQ, parents rating on fine motor skills was significantly related to total MABC-2 score; (p = .006, R = 0.402), manual dexterity (p= .038, R = 0.310), and aiming and catching (p-value = .005, R = 0.407). On the ASQ, parent\u27s ratings on fine motor skills were significantly related to total MABC-2 scores (p= .048, R = 0.303). Parent’s ratings on their child’s ASQ personal social skills were significantly related to total MABC-2 scores (p= .011, R = 0.385), and aiming and catching (p = .013, R = 0.377). No other correlations were significant amongst the parent assessments and child’s MABC scores. CONCLUSION: While neither assessment appeared to be more related to children\u27s actual scores than the other, in both assessments fines motors skills were more closely related to children\u27s actual performance

    Telomerase mediates lymphocyte proliferation but not the atherosclerosis-suppressive potential of regulatory T-cells

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    Objective: Atherosclerosis is an age-related disease characterised by systemic oxidative stress and low-grade inflammation. The role of telomerase and telomere length in atherogenesis remains contentious. Short telomeres of peripheral leukocytes are predictive for coronary artery disease. Conversely, attenuated telomerase has been demonstrated to be protective for atherosclerosis. Hence a potential causative role of telomerase in atherogenesis is critically debated. Approach and Results: In this study we used multiple mouse models to investigate the regulation of telomerase under oxidative stress as well as its impact on atherogenesis in vitro and in vivo. Using primary lymphocytes and myeloid cell cultures we demonstrate that cultivation under hyperoxic conditions induced oxidative stress resulting in chronic activation of CD4+ cells and significantly reduced CD4+ T-cell proliferation. The latter was telomerase dependent, as oxidative stress had no effect on the proliferation of primary lymphocytes isolated from telomerase-knock-out mice. In contrast, myeloid cell proliferation was unaffected by oxidative stress nor reliant on telomerase. Telomerase reverse transcriptase (TERT) deficiency had no effect on Treg numbers in vivo or suppressive function ex vivo. Adoptive transfer of TERT-/- Tregs into Rag2-/- ApoE-/- double knock out mice demonstrated that telomerase function was not required for the ability of Tregs to protect against atherosclerosis. However, telomere length was critical for Treg function. Conclusions: Telomerase contributes to lymphocyte proliferation but plays no major role in Treg function, provided that telomere length is not critically short. We suggest that oxidative stress may contribute to atherosclerosis via suppression of telomerase and acceleration of telomere attrition in Tregs.This study was supported, in part, by British Heart Foundation Project Grants PG/15/85/31744 and PG/12/47/29681 (www.BHF.org.uk) as well as the Newcastle Healthcare Charity (www.newcastle-hospitals. org.uk/patient-guides/charity-matters-at-newcastle-hospitals_charitable- funds.aspx). N.M. Al Zhrany was funded by a stipend from the Government of Saudi Arabia

    ÎČ[beta]-Catenin and FGFR2 regulate postnatal rosette-based adrenocortical morphogenesis

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    Rosettes are widely used in epithelial morphogenesis during embryonic development and organogenesis. However, their role in postnatal development and adult tissue maintenance remains largely unknown. Here, we show zona glomerulosa cells in the adult adrenal cortex organize into rosettes through adherens junction-mediated constriction, and that rosette formation underlies the maturation of adrenal glomerular structure postnatally. Using genetic mouse models, we show loss of beta-catenin results in disrupted adherens junctions, reduced rosette number, and dysmorphic glomeruli, whereas beta-catenin stabilization leads to increased adherens junction abundance, more rosettes, and glomerular expansion. Furthermore, we uncover numerous known regulators of epithelial morphogenesis enriched in beta-catenin-stabilized adrenals. Among these genes, we show Fgfr2 is required for adrenal rosette formation by regulating adherens junction abundance and aggregation. Together, our data provide an example of rosette-mediated postnatal tissue morphogenesis and a framework for studying the role of rosettes in adult zona glomerulosa tissue maintenance and function

    Generation of glucocorticoid-producing cells derived from human pluripotent stem cells.

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    Adrenal insufficiency is a life-threatening condition resulting from the inability to produce adrenal hormones in a dose- and time-dependent manner. Establishing a cell-based therapy would provide a physiologically responsive approach for the treatment of this condition. We report the generation of large numbers of human-induced steroidogenic cells (hiSCs) from human pluripotent stem cells (hPSCs). Directed differentiation of hPSCs into hiSCs recapitulates the initial stages of human adrenal development. Following expression of steroidogenic factor 1, activation of protein kinase A signaling drives a steroidogenic gene expression profile most comparable to human fetal adrenal cells, and leads to dynamic secretion of steroid hormones, in vitro. Moreover, expression of the adrenocorticotrophic hormone (ACTH) receptor/co-receptor (MC2R/MRAP) results in dose-dependent ACTH responsiveness. This protocol recapitulates adrenal insufficiency resulting from loss-of-function mutations in AAAS, which cause the enigmatic triple A syndrome. Our differentiation protocol generates sufficient numbers of hiSCs for cell-based therapy and offers a platform to study disorders causing adrenal insufficiency

    Generation of glucocorticoid-producing cells derived from human pluripotent stem cells

    Get PDF
    Adrenal insufficiency is a life-threatening condition resulting from the inability to produce adrenal hormones in a dose- and time-dependent manner. Establishing a cell-based therapy would provide a physiologically responsive approach for the treatment of this condition. We report the generation of large numbers of human-induced steroidogenic cells (hiSCs) from human pluripotent stem cells (hPSCs). Directed differentiation of hPSCs into hiSCs recapitulates the initial stages of human adrenal development. Following expression of steroidogenic factor 1, activation of protein kinase A signaling drives a steroidogenic gene expression profile most comparable to human fetal adrenal cells, and leads to dynamic secretion of steroid hormones, in vitro. Moreover, expression of the adrenocorticotrophic hormone (ACTH) receptor/co-receptor (MC2R/MRAP) results in dose-dependent ACTH responsiveness. This protocol recapitulates adrenal insufficiency resulting from loss-of-function mutations in AAAS, which cause the enigmatic triple A syndrome. Our differentiation protocol generates sufficient numbers of hiSCs for cell-based therapy and offers a platform to study disorders causing adrenal insufficiency
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