2,277 research outputs found

    A pilot randomized trial to examine effects of a hybrid closed-loop insulin delivery system on neurodevelopmental and cognitive outcomes in adolescents with type 1 diabetes

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    Type 1 diabetes (T1D) is associated with lower scores on tests of cognitive and neuropsychological function and alterations in brain structure and function in children. This proof-of-concept pilot study (ClinicalTrials.gov Identifier NCT03428932) examined whether MRI-derived indices of brain development and function and standardized IQ scores in adolescents with T1D could be improved with better diabetes control using a hybrid closed-loop insulin delivery system. Eligibility criteria for participation in the study included age between 14 and 17 years and a diagnosis of T1D before 8 years of age. Randomization to either a hybrid closed-loop or standard diabetes care group was performed after pre-qualification, consent, enrollment, and collection of medical background information. Of 46 participants assessed for eligibility, 44 met criteria and were randomized. Two randomized participants failed to complete baseline assessments and were excluded from final analyses. Participant data were collected across five academic medical centers in the United States. Research staff scoring the cognitive assessments as well as those processing imaging data were blinded to group status though participants and their families were not. Forty-two adolescents, 21 per group, underwent cognitive assessment and multi-modal brain imaging before and after the six month study duration. HbA1c and sensor glucose downloads were obtained quarterly. Primary outcomes included metrics of gray matter (total and regional volumes, cortical surface area and thickness), white matter volume, and fractional anisotropy. Estimated power to detect the predicted treatment effect was 0.83 with two-tailed, α = 0.05. Adolescents in the hybrid closed-loop group showed significantly greater improvement in several primary outcomes indicative of neurotypical development during adolescence compared to the standard care group including cortical surface area, regional gray volumes, and fractional anisotropy. The two groups were not significantly different on total gray and white matter volumes or cortical thickness. The hybrid closed loop group also showed higher Perceptual Reasoning Index IQ scores and functional brain activity more indicative of neurotypical development relative to the standard care group (both secondary outcomes). No adverse effects associated with study participation were observed. These results suggest that alterations to the developing brain in T1D might be preventable or reversible with rigorous glucose control. Long term research in this area is needed

    The neural basis of auditory temporal discrimination in girls with fragile X syndrome

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    Fragile X syndrome (FXS) is a common genetic disorder in which temporal processing may be impaired. To our knowledge however, no studies have examined the neural basis of temporal discrimination in individuals with FXS using functional magnetic resonance imaging (fMRI). Ten girls with fragile X syndrome and ten developmental age-matched typically developing controls performed an auditory temporal discrimination task in a 3T scanner. Girls with FXS showed significantly greater brain activation in a left-lateralized network, comprising left medial frontal gyrus, left superior and middle temporal gyrus, left cerebellum, and left brainstem (pons), when compared to a developmental age-matched typically developing group of subjects who had similar in-scanner task performance. There were no regions that showed significantly greater brain activation in the control group compared to individuals with FXS. These data indicate that networks of brain regions involved in auditory temporal processing may be dysfunctional in FXS. In particular, it is possible that girls with FXS employ left hemispheric resources to overcompensate for relative right hemispheric dysfunction

    Magnetostrictive materials for aerospace applications

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    Structural health monitoring of composite structures to detect barely visible damage is vitally important for the aerospace industry. This research has investigated amorphous magnetostrictive wires (Fe77.5Si7.5B15 and Co72.5Si12.5B15), as a possible solution to monitoring aerospace composites. The different amorphous wires were either embedded into the composite or epoxied on to the surface. How the wires effected the structure of the composite along with ultimate tensile strength was studied. Inductance measurements were used to study the strain within the composite, which provided a non-intrusive method of monitoring the composite

    Systematic review of studies of mental health nurses' experience of anger and of its relationships with their attitudes and practice

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    IntroductionEmotional regulation is important in mental health nursing practice but individual emotions may require different regulation strategies. There is ample evidence that nurses experience anger specifically during their work, for example when experiencing patient aggression. It is, therefore, important to consolidate what is known about how anger manifests in mental health nursing practice.AimWe aimed to systematically identify, evaluate, and synthesise results from studies about mental health nurses and anger, where anger was measured objectively.MethodsSystematic literature review based on PRISMA guidelines.Results.We identified 12 studies. A range of validated and non-validated instruments were used. Mental health nurses may have lower levels of anger than normative samples but anger is commonly reported as an issue for them. Anger was studied in relation to its links with i) clinical management of patients, notably violence containment; and ii) employment issues more generally, notably job motivation. Anger is related to nurses’ attitudes about the acceptability of coercion but there is no evidence that it results in more coercion.Implications for practiceNurses should be aware of the potential influence of anger on their practice. Anger, specifically, should be considered when supporting mental health nurses, for example in clinical supervision. Emotional regulation training should target anger

    Exploitation of conserved eukaryotic host cell farnesylation machinery by an F-box effector of Legionella pneumophila

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    Farnesylation involves covalent linkage of eukaryotic proteins to a lipid moiety to anchor them into membranes, which is essential for the biological function of Ras and other proteins. A large cadre of bacterial effectors is injected into host cells by intravacuolar pathogens through elaborate type III–VII translocation machineries, and many of these effectors are incorporated into the pathogen-containing vacuolar membrane by unknown mechanisms. The Dot/Icm type IV secretion system of Legionella pneumophila injects into host cells the F-box effector Ankyrin B (AnkB), which functions as platforms for the docking of polyubiquitinated proteins to the Legionella-containing vacuole (LCV) to enable intravacuolar proliferation in macrophages and amoeba. We show that farnesylation of AnkB is indispensable for its anchoring to the cytosolic face of the LCV membrane, for its biological function within macrophages and Dictyostelium discoideum, and for intrapulmonary proliferation in mice. Remarkably, the protein farnesyltransferase, RCE-1 (Ras-converting enzyme-1), and isoprenyl cysteine carboxyl methyltransferase host farnesylation enzymes are recruited to the LCV in a Dot/Icm-dependent manner and are essential for the biological function of AnkB. In conclusion, this study shows novel localized recruitment of the host farnesylation machinery and its anchoring of an F-box effector to the LCV membrane, and this is essential for biological function in vitro and in vivo

    Performing the Egyptian revolution : origins of collective restraint action in the Midan

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    This research was supported by a Carnegie Trust for the Universities of Scotland grant.In January/February 2011, the world watched with admiration the Egyptian revolution that toppled President Housni Mubarak. The demonstration in Midan al-Tahrir (Liberation Square in central Cairo), which was the nucleus of the revolution, highlighted a largely spontaneous, civil and peaceful political performance. However, this performance was temporary, contradicting subsequent bloody conflicts in post-revolutionary Egypt. This article examines the socio-political origins of the Midan performance. It argues that the demonstrators exercised collective restraint, which was temporary but necessary, in order to topple Mubarak. Building on Norbert Elias’ civilising process theory and social movements literature, it is argued that the origins of this performance are found in a collective knowledge of regime strategy and narrative, Egyptian socio-political values and existing repertoires of contention. Drawing on primary sources and semi-structured interviews, the article contends that the demonstrators exercised collective restraint to reframe regime narrative and draw public support for the revolution.PostprintPeer reviewe

    A solution to limitations of cognitive testing in children with intellectual disabilities: the case of fragile X syndrome

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    Intelligence testing in children with intellectual disabilities (ID) has significant limitations. The normative samples of widely used intelligence tests, such as the Wechsler Intelligence Scales, rarely include an adequate number of subjects with ID needed to provide sensitive measurement in the very low ability range, and they are highly subject to floor effects. The IQ measurement problems in these children prevent characterization of strengths and weaknesses, poorer estimates of cognitive abilities in research applications, and in clinical settings, limited utility for assessment, prognosis estimation, and planning intervention. Here, we examined the sensitivity of the Wechsler Intelligence Scale for Children (WISC-III) in a large sample of children with fragile X syndrome (FXS), the most common cause of inherited ID. The WISC-III was administered to 217 children with FXS (age 6–17 years, 83 girls and 134 boys). Using raw norms data obtained with permission from the Psychological Corporation, we calculated normalized scores representing each participant’s actual deviation from the standardization sample using a z-score transformation. To validate this approach, we compared correlations between the new normalized scores versus the usual standard scores with a measure of adaptive behavior (Vineland Adaptive Behavior Scales) and with a genetic measure specific to FXS (FMR1 protein or FMRP). The distribution of WISC-III standard scores showed significant skewing with floor effects in a high proportion of participants, especially males (64.9%–94.0% across subtests). With the z-score normalization, the flooring problems were eliminated and scores were normally distributed. Furthermore, we found correlations between cognitive performance and adaptive behavior, and between cognition and FMRP that were very much improved when using these normalized scores in contrast to the usual standardized scores. The results of this study show that meaningful variation in intellectual ability in children with FXS, and probably other populations of children with neurodevelopmental disorders, is obscured by the usual translation of raw scores into standardized scores. A method of raw score transformation may improve the characterization of cognitive functioning in ID populations, especially for research applications

    Behavior Problems in Relation to Sustained Selective Attention Skills of Moderately Preterm Children

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    Attention skills may form an important developmental mechanism. A mediation model was examined in which behavioral problems of moderately preterm and term children at school age are explained by attention performance. Parents and teachers completed behavioral assessments of 348 moderately preterm children and 182 term children at 8 years of age. Children were administered a test of sustained selective attention. Preterm birth was associated with more behavioral and attention difficulties. Gestational age, prenatal maternal smoking, and gender were associated with mothers’, fathers’, and teachers’ reports of children’s problem behavior. Sustained selective attention partially mediated the relationship between birth status and problem behavior. Development of attention skills should be an important focus for future research in moderately preterm children

    Leftward Lateralization of Auditory Cortex Underlies Holistic Sound Perception in Williams Syndrome

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    BACKGROUND: Individuals with the rare genetic disorder Williams-Beuren syndrome (WS) are known for their characteristic auditory phenotype including strong affinity to music and sounds. In this work we attempted to pinpoint a neural substrate for the characteristic musicality in WS individuals by studying the structure-function relationship of their auditory cortex. Since WS subjects had only minor musical training due to psychomotor constraints we hypothesized that any changes compared to the control group would reflect the contribution of genetic factors to auditory processing and musicality. METHODOLOGY/PRINCIPAL FINDINGS: Using psychoacoustics, magnetoencephalography and magnetic resonance imaging, we show that WS individuals exhibit extreme and almost exclusive holistic sound perception, which stands in marked contrast to the even distribution of this trait in the general population. Functionally, this was reflected by increased amplitudes of left auditory evoked fields. On the structural level, volume of the left auditory cortex was 2.2-fold increased in WS subjects as compared to control subjects. Equivalent volumes of the auditory cortex have been previously reported for professional musicians. CONCLUSIONS/SIGNIFICANCE: There has been an ongoing debate in the neuroscience community as to whether increased gray matter of the auditory cortex in musicians is attributable to the amount of training or innate disposition. In this study musical education of WS subjects was negligible and control subjects were carefully matched for this parameter. Therefore our results not only unravel the neural substrate for this particular auditory phenotype, but in addition propose WS as a unique genetic model for training-independent auditory system properties
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