865 research outputs found

    Effectiveness of robotic exoskeletons for improving gait in children with cerebral palsy: a systematic review

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    Abstract Background: Robotic exoskeletons have been developed to assist locomotion and address gait abnormalities in children with cerebral palsy (CP). These wearable assistive devices provide powered assistance to the lower-extremity joints, as well as support and stability. Research Question: Does exoskeleton-assisted walking improve gait in children with CP? Methods: The PRISMA guidelines were used to conduct this systematic review. Articles were obtained in a search of the following electronic databases: Embase, CINAHL Complete, PubMed, Web of Science and MEDLINE. Studies investigating spatiotemporal, kinematic, kinetic, muscle activity and/or physiological parameters during exoskeleton-assisted walking in children with CP were included. All articles were assessed for methodological quality using an adapted version of the Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group, provided by NIH. Results: Thirteen studies were included. They involved the use of the following exoskeletons: tethered knee exoskeleton, pediatric knee exoskeleton (P.REX), untethered ankle exoskeleton, WAKE-Up ankle module, WAKE-Up ankle & knee module and unilateral ankle exosuit. Methodological quality varied, with key limitations in sample size and allocated time to adapt to the exoskeleton. There was a consensus that robotic exoskeletons improve gait given careful optimisation of exoskeleton torque and sufficient exoskeleton practice time for each participant. Improvements in gait included reduced metabolic cost of walking, increased walking speed, and increased knee and hip extension during stance. Furthermore, exoskeletons with an actuated ankle module were shown to promote normal ankle rocker function. Significance: Robotic exoskeletons have the potential to improve the mobility of CP children and may therefore increase community participation and improve quality of life. Future work should involve larger controlled intervention studies utilising robotic exoskeletons to improve gait in children with CP. These studies should ensure sufficient exoskeleton practice time for each participant

    Relative contribution of multiple stressors on copepod density and diversity dynamics in the Belgian part of the North Sea

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    The effect of multiple stressors on marine ecosystems is poorly understood. To partially bridge this knowledge gap we investigated the relative contribution of environmental variables to density and diversity dynamics of the zooplankton community in the Belgian part of the North Sea. We applied multimodel inference on generalized additive models to quantify the relative contribution of chlorophyll a, temperature, nutrients, salinity and anthropogenic chemicals (i.e. polychlorinated biphenyls and polycyclic aromatic hydrocarbons) to the dynamics of calanoid copepod species in the Belgian part of the North Sea. Temperature was the only predictor consistently showing a high importance in all models predicting the abundances of the selected copepod species. The relative contribution of other predictors was species-dependent. Anthropogenic chemicals were important predictors for three out of six species indicating that chemical mixtures at low concentrations should not be left unattended when performing risk assessments in a natural environment

    Sex-biased mortality of common terns in wind farm collisions

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    We studied sex differences in collision mortality in adult Common Terns (Sterna hirundo) at a wind farm in the direct vicinity of a breeding site in Zeebrugge, Belgium in 2005-2007. In total, 64 fatalities were collected and sexed, of which 64% were males. Uneven sex ratio among these birds was most pronounced during the period of incubation and early chick feeding (15 May-15 June), when 78% of the 28mortalities were male. During prelaying and feeding of young, the sex ratio of mortalities did not differ from equality. We argue that sex-biased collision mortality in Common Terns does not result from morphological differences between the sexes, but rather reflects differences in foraging frequency between males and females during egg-laying and incubation

    Multimodel inference to quantify the relative importance of abiotic factors in the population dynamics of marine zooplankton

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    The effect of multiple stressors on marine ecosystems remains poorly understood and most of the knowledge available is related to phytoplankton. To partly address this knowledge gap, we tested if combining multimodel inference with generalized additive modelling could quantify the relative contribution of environmental variables on the population dynamics of a zooplankton species in the Belgian part of the North Sea. Hence, we have quantified the relative contribution of oceanographic variables (e.g. water temperature, salinity, nutrient concentrations, and chlorophyll a concentrations) and anthropogenic chemicals (i.e. polychlorinated biphenyls) to the density of Acartia clausi. We found that models with water temperature and chlorophyll a concentration explained ca. 73% of the population density of the marine copepod. Multimodel inference in combination with regression-based models are a generic way to disentangle and quantify multiple stressor-induced changes in marine ecosystems. Future–oriented simulations of copepod densities suggested increased copepod densities under predicted environmental changes

    Seasonal and spatial fatty acid profiling of the calanoid copepods <i>Temora longicornis</i> and <i>Acartia clausi</i> linked to environmental stressors in the North Sea

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    The Belgian part of the North Sea (BPNS) is subjected to multiple environmental stressors. The impact of these stressors includes the modulation of fatty acid (FA) composition of the zooplankton. This study recorded temporal and spatial patterns of the FA profiles of two dominant calanoid copepods within the BPNS: Temora longicornis (MĂĽller, 1785) and Acartia clausi (Giesbrecht, 1889). By means of distance-based linear modelling and by applying multi model inference to generalized additive models, environmental stressors were linked to patterns of the FA profiles of these species. The FA profiles of A. clausi and T. longicornis showed distinct intraspecific, spatial and temporal differences within the BPNS. Temperature and algal food quality (marked by the ratio of silicate concentration to dissolved inorganic nitrogen concentration, SiO4/DIN) were the most important drivers of seasonal fluctuations in the DHA/EPA ratio of both species. DHA/EPA ratio can be used as marker for stress in copepods in the BPNS in order to have a quick indication of food quality changes at the basis of the food web

    Interplay between uncertainty intolerance, emotion regulation, cognitive flexibility, and psychopathology during the COVID-19 pandemic:A multi-wave study

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    The COVID-19 pandemic has created a significant mental health burden on the global population. Studies during the pandemic have shown that risk factors such as intolerance of uncertainty and maladaptive emotion regulation are associated with increased psychopathology. Meanwhile, protective factors such as cognitive control and cognitive flexibility have been shown to protect mental health during the pandemic. However, the potential pathways through which these risk and protective factors function to impact mental health during the pandemic remain unclear. In the present multi-wave study, 304 individuals (18 years or older, 191 Males), residing in the USA during data collection, completed weekly online assessments of validated questionnaires across a period of five weeks (27th March 2020-1st May 2020). Mediation analyses revealed that longitudinal changes in emotion regulation difficulties mediated the effect of increases in intolerance of uncertainty on increases in stress, depression, and anxiety during the COVID-19 pandemic. Further, individual differences in cognitive control and flexibility moderated the relationship between intolerance of uncertainty and emotion regulation difficulties. While intolerance of uncertainty and emotion regulation difficulties emerged as risk factors for mental health, cognitive control and flexibility seems to protect against the negative effects of the pandemic and promote stress resilience. Interventions aimed at enhancing cognitive control and flexibility might promote the protection of mental health in similar global crises in the future
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