247 research outputs found

    Changes in Cognitive Networks as a Result of Sport-Related Concussion

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    Given the high prevalence of concussion in sports, assessment of cognition has become a standard part of athletics, and results are used to inform return to play decisions. Neurocognitive measures (e.g., ImPACT) generate cognitive composite scores from individual subtests, and these scores are compared at baseline and post-concussion. Declines in scores provide evidence for concussive injury, and athletes undergo repeated assessments until their scores and symptoms improve. Recent research suggests that changes in the associations between test scores may provide important information about cognitive recovery. A network framework may help identify post-concussive cognitive changes that may not be apparent when composite scores are compared. The present study examined composite-level comparisons and network-level comparisons to see whether network models could better characterize SRC recovery. Athletes were administered ImPACT at preseason and post-SRC (acute assessment = 72 hours of injury, recovery assessment = within two weeks post-injury). Repeated measures ANOVA was conducted to examine differences in composite scores over time. Cognitive networks were estimated for the baseline, acute, and recovery assessment time points. Centrality indices were calculated to determine relative importance of each cognitive variable in each network. Network comparison tests were conducted to examine differences in network structure, connectedness, and centrality over time. Repeated measures ANOVA results revealed an initial decline in composite scores acutely post-SRC followed by improvement in scores at recovery. Network analysis results indicated significantly increased network connectivity in both the acute and recovery networks compared to the baseline network. Additionally, network structure changed significantly from baseline to recovery. Visual memory and processing speed nodes were highly central and influential within each network. Network comparisons also revealed changes in centrality over time. Specifically, visual memory nodes became more central and influential over time, and impulsivity nodes became more central from acute to recovery. While composite scores suggested cognitive recovery, cognitive network comparisons revealed lingering network disruption at the recovery time point. Increased connectivity may reflect increased effort to complete cognitive tasks, while changes in network structure suggest that compensatory strategies may be used to achieve task demands. Given that visual memory and impulsivity played an increasingly central role in networks over time, it may be helpful to target these processes during treatment. Future research should examine whether certain pre-injury characteristics (e.g., neurodevelopmental history) moderate longitudinal changes in cognitive networks

    A Video-based End-to-end Pipeline for Non-nutritive Sucking Action Recognition and Segmentation in Young Infants

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    We present an end-to-end computer vision pipeline to detect non-nutritive sucking (NNS) -- an infant sucking pattern with no nutrition delivered -- as a potential biomarker for developmental delays, using off-the-shelf baby monitor video footage. One barrier to clinical (or algorithmic) assessment of NNS stems from its sparsity, requiring experts to wade through hours of footage to find minutes of relevant activity. Our NNS activity segmentation algorithm solves this problem by identifying periods of NNS with high certainty -- up to 94.0\% average precision and 84.9\% average recall across 30 heterogeneous 60 s clips, drawn from our manually annotated NNS clinical in-crib dataset of 183 hours of overnight baby monitor footage from 19 infants. Our method is based on an underlying NNS action recognition algorithm, which uses spatiotemporal deep learning networks and infant-specific pose estimation, achieving 94.9\% accuracy in binary classification of 960 2.5 s balanced NNS vs. non-NNS clips. Tested on our second, independent, and public NNS in-the-wild dataset, NNS recognition classification reaches 92.3\% accuracy, and NNS segmentation achieves 90.8\% precision and 84.2\% recall

    Older women, breast cancer, and social support

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    One in ten women over the age of 65 will develop breast cancer. Despite this high incidence of breast cancer among older women, social support for them is often inadequate. This paper describes a qualitative study of the impact of a breast cancer diagnosis on older women from racially/ethnically diverse populations and their subsequent need for social support. Forty-seven older African American, Asian American, Caucasian and Latina women between the ages of 65 to 83 participated in a larger study examining the impact of breast cancer on women from racially/ethnically diverse populations and the meaning and nature of social support. The women completed an in-depth qualitative interview on the psychosocial impact of breast cancer and the meaning and nature of social support. The results indicate that there are variations in reactions to a breast cancer diagnosis among older women, and that these reactions impact their experiences with seeking social support at diagnosis and during treatment. Respondents were concerned about their aging bodies, potential dependency on others, and loss of autonomy. At the same time, the severity of cancer treatment and existing co-morbidities often meant they needed to learn to receive support, and to reach out if they had no support. The implications of these findings underscore the older cancer patient’s need to strengthen her supportive networks at the time of diagnosis, during treatment, and post-treatment

    Arbuscular mycorrhizal colonisation of roots of grass species differing in invasiveness

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    Recent research indicates that the soil microbial community, particularly arbuscular mycorrhizal fungi (AMF), can influence plant invasion in several ways. We tested if 1) invasive species are colonised by AMF to a lower degree than resident native species, and 2) AMF colonisation of native plants is lower in a community inhabited by an invasive species than in an uninvaded resident community. The two tests were run in semiarid temperate grasslands on grass (Poaceae) species, and the frequency and intensity of mycorrhizal colonisation, and the proportion of arbuscules and vesicles in plant roots have been measured. In the first test, grasses representing three classes of invasiveness were included: invasive species, resident species becoming abundant upon disturbance, and non-invasive native species. Each class contained one C3 and one C4 species. The AMF colonisation of the invasive Calamagrostis epigejos and Cynodon dactylon was consistently lower than that of the non-invasive native Chrysopogon gryllus and Bromus inermis, and contained fewer arbuscules than the post-disturbance dominant resident grasses Bothriochloa ischaemum and Brachypodium pinnatum. The C3 and C4 grasses behaved alike despite their displaced phenologies in these habitats. The second test compared AMF colonisation for sand grassland dominant grasses Festuca vaginata and Stipa borysthenica in stands invaded by either C. epigejos or C. dactylon, and in the uninvaded natural community. Resident grasses showed lower degree of AMF colonisation in the invaded stand compared to the uninvaded natural community with F. vaginata responding so to both invaders, while S. borysthenica responding to C. dactylon only. These results indicate that invasive grasses supposedly less reliant on AMF symbionts have the capacity of altering the soil mycorrhizal community in such a way that resident native species can establish a considerably reduced extent of the beneficial AMF associations, hence their growth, reproduction and ultimately abundance may decline. Accumulating evidence suggests that such indirect influences of invasive alien plants on resident native species mediated by AMF or other members of the soil biota is probably more the rule than the exception

    Campylobacter pylori is not associated with gastroparesis

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    There is a high incidence of Campylobacter pylori in the gastric mucosa of patients with duodenal ulcer, gastric ulcer, and nonulcer dyspepsia. Factors that lead to development of this infection are unknown. We hypothesized that delayed solid-phase gastric emptying, a condition characterized by antral stasis, might predispose to Campylobacter pylori infection. We prospectively studied 51 patients with symptoms of gastroparesis using a solid-phase gastric emptying study and upper endoscopy. Patients were excluded if they had predominant symptoms of epigastric pain or an abnormal endoscopy. Three biopsies were obtained from the antrum and stained with H&E. When any inflammation was present, a Warthin-Starry stain was also performed. These were blindly examined for chronic inflammation, activity, and presence of Campylobacter pylori. Campylobacter pylori was not more common in patients with gastroparesis, documented by delayed gastric emptying, than in patients with a normal emptying study. On the contrary, there was a significantly lower incidence of Campylobacter pylori in those with delayed emptying compared to those with normal emptying (5% vs 31% , P<0.05). Gastritis activity correlated closely with Campylobacter presence. Inactive chronic gastritis with Campylobacter was equally common in those with delayed or normal gastric emptying. Diabetics were no more likely to harbor Campylobacter pylori than nondiabetics (16% vs 25%). The 5% incidence of Campylobacter in the gastroparesis group is less than, but approaches, that previously reported in asymptomatic controls. The 31% incidence of Campylobacter in the group with symptoms of gastroparesis but normal gastric emptying approaches that reported for nonulcer dyspepsia. Our data suggest that gastroparesis does not predispose to Campylobacter pylori infection or histologic chronic gastritis .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44408/1/10620_2005_Article_BF01540043.pd

    Design and baseline characteristics of the ParkFit study, a randomized controlled trial evaluating the effectiveness of a multifaceted behavioral program to increase physical activity in Parkinson patients

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    <p>Abstract</p> <p>Background</p> <p>Many patients with Parkinson's disease (PD) lead a sedentary lifestyle. Promotion of physical activities may beneficially affect the clinical presentation of PD, and perhaps even modify the course of PD. However, because of physical and cognitive impairments, patients with PD require specific support to increase their level of physical activity.</p> <p>Methods</p> <p>We developed the ParkFit Program: a PD-specific and multifaceted behavioral program to promote physical activity. The emphasis is on creating a behavioral change, using a combination of accepted behavioral motivation techniques. In addition, we designed a multicentre randomized clinical trial to investigate whether this ParkFit Program increases physical activity levels over two years in sedentary PD patients. We intended to include 700 sedentary patients. Primary endpoint is the time spent on physical activities per week, which will be measured every six months using an interview-based 7-day recall.</p> <p>Results</p> <p>In total 3453 PD patients were invited to participate. Ultimately, 586 patients - with a mean (SD) age of 64.1 (7.6) years and disease duration of 5.3 (4.5) years - entered the study. Study participants were younger, had a shorter disease duration and were less sedentary compared with eligible PD patients not willing to participate.</p> <p>Discussion</p> <p>The ParkFit trial is expected to yield important new evidence about behavioral interventions to promote physical activity in sedentary patients with PD. The results of the trial are expected in 2012.</p> <p>Trial registration</p> <p><url>http://clinicaltrials.gov</url> (nr NCT00748488).</p

    The biogeochemical impact of glacial meltwater from Southwest Greenland

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    Biogeochemical cycling in high-latitude regions has a disproportionate impact on global nutrient budgets. Here, we introduce a holistic, multi-disciplinary framework for elucidating the influence of glacial meltwaters, shelf currents, and biological production on biogeochemical cycling in high-latitude continental margins, with a focus on the silica cycle. Our findings highlight the impact of significant glacial discharge on nutrient supply to shelf and slope waters, as well as surface and benthic production in these regions, over a range of timescales from days to thousands of years. Whilst biological uptake in fjords and strong diatom activity in coastal waters maintains low dissolved silicon concentrations in surface waters, we find important but spatially heterogeneous additions of particulates into the system, which are transported rapidly away from the shore. We expect the glacially-derived particles – together with biogenic silica tests – to be cycled rapidly through shallow sediments, resulting in a strong benthic flux of dissolved silicon. Entrainment of this benthic silicon into boundary currents may supply an important source of this key nutrient into the Labrador Sea, and is also likely to recirculate back into the deep fjords inshore. This study illustrates how geochemical and oceanographic analyses can be used together to probe further into modern nutrient cycling in this region, as well as the palaeoclimatological approaches to investigating changes in glacial meltwater discharge through time, especially during periods of rapid climatic change in the Late Quaternary

    Long-baseline neutrino oscillation physics potential of the DUNE experiment

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    The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σ, for all ΑCP values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all ΑCP values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to sin22θ13 to current reactor experiments

    The DUNE Far Detector Interim Design Report, Volume 3: Dual-Phase Module

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    The DUNE IDR describes the proposed physics program and technical designs of the DUNE far detector modules in preparation for the full TDR to be published in 2019. It is intended as an intermediate milestone on the path to a full TDR, justifying the technical choices that flow down from the high-level physics goals through requirements at all levels of the Project. These design choices will enable the DUNE experiment to make the ground-breaking discoveries that will help to answer fundamental physics questions. Volume 3 describes the dual-phase module's subsystems, the technical coordination required for its design, construction, installation, and integration, and its organizational structure

    Long-baseline neutrino oscillation physics potential of the DUNE experiment

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    The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σ, for all δ_(CP) values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all δ_(CP) values. It will also make precise measurements of other parameters governing long-baseline neutrino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to sin²θ₁₃ to current reactor experiments
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