66 research outputs found

    Gaussian process regression bootstrapping: exploring the effects of uncertainty in time course data

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    Motivation: Although widely accepted that high-throughput biological data are typically highly noisy, the effects that this uncertainty has upon the conclusions we draw from these data are often overlooked. However, in order to assign any degree of confidence to our conclusions, we must quantify these effects. Bootstrap resampling is one method by which this may be achieved. Here, we present a parametric bootstrapping approach for time-course data, in which Gaussian process regression (GPR) is used to fit a probabilistic model from which replicates may then be drawn. This approach implicitly allows the time dependence of the data to be taken into account, and is applicable to a wide range of problems

    Atmospheric and Surface Processes, and Feedback Mechanisms Determining Arctic Amplification: A Review of First Results and Prospects of the (AC)3 Project

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    Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC)3 project has been established in 2016. It comprises modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, ship-borne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data

    Structural brain lesions in adolescents with congenital heart disease

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    Objectives To assess long-term neurodevelopmental outcome of adolescents with congenital heart disease after open-heart surgery and to evaluate whether deficits are associated with cerebral injury detectable on magnetic resonance imaging (MRI). Study design We conducted a cohort study with longitudinal follow-up of 53 adolescents (mean age, 13.7 years; range, 11.4 to 16.9 years) who had undergone open-heart surgery with full-flow cardiopulmonary bypass during childhood and compared them with 41 age-matched controls. Assessment included conventional MRI and neurodevelopmental testing. Results MRI abnormalities were detected in 11 of the 53 patients (21%), comprising predominately white matter abnormalities and volume loss. Neurodevelopmental outcome was impaired in several domains, including neuromotor, intellectual, and executive functions, as well as visuomotor perception and integration. Adolescents with cerebral abnormalities had greater impairment in most neurodevelopmental domains compared with those without cerebral abnormalities. Conclusions Cerebral abnormalities can be detected in a significant proportion of adolescents with corrected congenital heart disease. These abnormalities are found predominately in the white matter and are apparently of hypoxic-ischemic origin, most likely acquired during the neonatal period

    Brain volumes predict neurodevelopment in adolescents after surgery for congenital heart disease.

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    Patients with complex congenital heart disease are at risk for neurodevelopmental impairments. Evidence suggests that brain maturation can be delayed and pre- and postoperative brain injury may occur, and there is limited information on the long-term effect of congenital heart disease on brain development and function in adolescent patients. At a mean age of 13.8 years, 39 adolescent survivors of childhood cardiopulmonary bypass surgery with no structural brain lesions evident through conventional cerebral magnetic resonance imaging and 32 healthy control subjects underwent extensive neurodevelopmental assessment and cerebral magnetic resonance imaging. Cerebral scans were analysed quantitatively using surface-based and voxel-based morphometry. Compared with control subjects, patients had lower total brain (P = 0.003), white matter (P = 0.004) and cortical grey matter (P = 0.005) volumes, whereas cerebrospinal fluid volumes were not different. Regional brain volume reduction ranged from 5.3% (cortical grey matter) to 11% (corpus callosum). Adolescents with cyanotic heart disease showed more brain volume loss than those with acyanotic heart disease, particularly in the white matter, thalami, hippocampi and corpus callosum (all P-values < 0.05). Brain volume reduction correlated significantly with cognitive, motor and executive functions (grey matter: P < 0.05, white matter: P < 0.01). Our findings suggest that there are long-lasting cerebral changes in adolescent survivors of cardiopulmonary bypass surgery for congenital heart disease and that these changes are associated with functional outcome

    Motor dysfunction and behavioural problems frequently coexist with congenital heart disease in school-age children

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    AIM: Patients with congenital heart disease are at risk of neurodevelopmental deficits. Impairments in motor and behavioural function occur frequently, but no information is available concerning the coexistence of deficits in these two developmental domains. This study explored the occurrence of motor and behavioural deficits and their coexistence in children with surgically corrected congenital heart disease. METHODS: Outcome was assessed in 95 children with congenital heart disease who had undergone cardiopulmonary bypass surgery. Their mean age was 9.6 years (SD 2.5). Motor function was assessed with the Zurich Neuromotor Assessment and behaviour with the Strength and Difficulties Questionnaire. RESULTS: Children with congenital heart disease performed poorer in all motor domains compared with the reference population (all p ā‰¤ 0.001). Behaviour was affected in the domains 'emotional symptoms' and 'hyperactivity/inattention' (both p < 0.01), and 54% of the children with motor abnormalities showed behavioural deficits. Children with coexistent abnormalities in behaviour and motor function had higher rates of remedial school services and therapeutic support. CONCLUSION: Children with congenital heart disease are at risk of long-term motor and behavioural problems, and there is a high rate of coexistence of problems in both domains. Early and longitudinal assessment of all developmental domains is necessary to provide adequate early support
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