2,257 research outputs found

    Somesthetic Functions in Patients with Brain Disease and Normal Subjects

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    This paper summarizes the results of a series of studies of somatosensory function in normal and brain-diseased subjects that were designed to investigate: (1) neural mechanisms in tactile resolution and masking, and; (2) cerebral dominance and somesthesis. Our results are consistent with the possibility that lateral inhibition effects influence tactile resolution and masking. Additional findings suggest that the physiologic mechanisms involved in tactile masking and obscuration in healthy subjects also mediate the pathologic expressions of these phenomena shown by patients with cerebral disease. Studies of hemispheric dominance and somesthesis have indicated that patients with right hemisphere disease often demonstrate bilateral impairment in tactile perception of direction while this deficit is confined to the right hand of patients with left hemisphere disease. Consistent with the implications of these clinical findings, right-handed normal subjects show a left-hand superiority for tactile perception of direction. Bilateral impairment on a proprioception task was found for patients with unilateral cerebral disease of either hemisphere. However, only patients with right hemisphere lesions were unable to utilize increments in proprioceptive feedback to improve their performance. The results on tactile perception of direction and proprioceptive feedback are interpreted as consistent with findings for other sensory modalities that point to the crucial role of the right hemisphere in spatial aspects of perception

    Deficits in Analogical Reasoning in Adolescents with Traumatic Brain Injury

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    Individuals with traumatic brain injury (TBI) exhibit deficits in executive control, which may impact their reasoning abilities. Analogical reasoning requires working memory and inhibitory abilities. In this study, we tested adolescents with moderate to severe TBI and typically developing (TD) controls on a set of picture analogy problems. Three factors were varied: complexity (number of relations in the problems), distraction (distractor item present or absent), and animacy (living or non-living items in the problems). We found that TD adolescents performed significantly better overall than TBI adolescents. There was also an age effect present in the TBI group where older participants performed better than younger ones. This age effect was not observed in the TD group. Performance was affected by complexity and distraction. Further, TBI participants exhibited lower performance with distractors present than TD participants. The reasoning deficits exhibited by the TBI participants were correlated with measures of executive function that required working memory updating, attention, and attentional screening. Using MRI-derived measures of cortical thickness, correlations were carried out between task accuracy and cortical thickness. The TD adolescents showed negative correlations between thickness and task accuracy in frontal and temporal regions consistent with cortical maturation in these regions. This study demonstrates that adolescent TBI results in impairments in analogical reasoning ability. Further, TBI youth have difficulty effectively screening out distraction, which may lead to failures in comprehension of the relations among items in visual scenes. Lastly, TBI youth fail to show robust cortical–behavior correlations as observed in TD individuals

    An integrated environmental and human systems modeling framework for Puget Sound restoration planning

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    Local, state, federal, tribal and private stakeholders have committed significant resources to restoring Puget Sound’s terrestrial-marine ecosystem. Though jurisdictional issues have promoted a fragmented approach to restoration planning, there is growing recognition that a more coordinated systems-based restoration approach is needed to achieve recovery goals. This presentation describes our collaborative effort to develop and apply an integrated environmental and human systems modeling framework for the Puget Sound Basin, inclusive of all marine and land areas (1,020 and 12,680 sq. mi.). Our goal is to establish a whole-basin systems modeling framework that dynamically simulates biophysical interactions and transfers (water, nutrients, contaminants, biota) across terrestrial-marine boundaries. The core environmental models include a terrestrial ecohydrological model (VELMA), an ocean circulation and biogeochemistry model (Salish Sea Model), and an ocean food web model (Atlantis). This environmental subsystem will be linked with an agent-based modeling subsystem (e.g., Envision) that allows human decision-makers to be represented in whole-basin simulations. The integrated environmental and human systems framework aims to facilitate discourse among different stakeholders and decision makers (agents) and enable them play out the ecological, social and economic consequences of alternative ecosystem restoration choices. All of these models are currently being applied in Puget Sound, but they have not yet been integrated. The linked models will better capture the propagation of human impacts throughout the terrestrial-marine ecosystem, and thereby provide a more effective decision support tool for addressing restoration of high priority environmental endpoints, such as the Vital Signs identified by the Puget Sound Partnership (http://www.psp.wa.gov/vitalsigns/). Our overview will include examples of existing stand-alone model applications, and conceptual plans for linking models across terrestrial-marine boundaries. The Puget Sound multi-model framework described here can potentially be expanded to address the entire Salish Sea transboundary ecosystem (https://www.eopugetsound.org/maps/salish-sea-basin-and-water-boundaries)

    Lack of Effect of Induction of Hypothermia after Acute Brain Injury

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    Background Induction of hypothermia in patients with brain injury was shown to improve outcomes in small clinical studies, but the results were not definitive. To study this issue, we conducted a multicenter trial comparing the effects of hypothermia with those of normothermia in patients with acute brain injury. Methods The study subjects were 392 patients 16 to 65 years of age with coma after sustaining closed head injuries who were randomly assigned to be treated with hypothermia (body temperature, 33°C), which was initiated within 6 hours after injury and maintained for 48 hours by means of surface cooling, or normothermia. All patients otherwise received standard treatment. The primary outcome measure was functional status six months after the injury. Results The mean age of the patients and the type and severity of injury in the two treatment groups were similar. The mean (±SD) time from injury to randomization was 4.3±1.1 hours in the hypothermia group and 4.1±1.2 hours in the normothermia group, and the mean time from injury to the achievement of the target temperature of 33°C in the hypothermia group was 8.4±3.0 hours. The outcome was poor (defined as severe disability, a vegetative state, or death) in 57 percent of the patients in both groups. Mortality was 28 percent in the hypothermia group and 27 percent in the normothermia group (P=0.79). The patients in the hypothermia group had more hospital days with complications than the patients in the normothermia group. Fewer patients in the hypothermia group had high intracranial pressure than in the normothermia group. Conclusions Treatment with hypothermia, with the body temperature reaching 33°C within eight hours after injury, is not effective in improving outcomes in patients with severe brain injury. (N Engl J Med 2001; 344:556-63.

    Beyond critique: the value of co-production in realising just cities?

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    This paper contributes to the burgeoning literature on the role of academic–practice relationships in contributing to sustainable urban development. We argue that co-production offers a potential pathway for academics to work with policy-makers in moving towards the realisation of more just cities. The paper starts from the position that there is an essential need for, but limit to, critique alone in contributing to the possibility of urban change. Moving towards a shared critique as a basis for future action is an important precondition for realising more just cities, adding weight to the voices arguing for alternative urban visions. These arguments are advanced through a study conducted by academic researchers and policy-makers in the Greater Manchester Low Carbon Hub. The paper outlines a process for working with existing urban institutions within institutional constraints to develop affirmative actions with the aim of longer term transformations. A key contribution is then the identification of eight markers for assessing progress towards the realisation of more just cities

    Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

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    FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir Orduña for the scientific advice and technical assistance.Peer reviewedPublisher PD

    Recommendations for the use of common outcome measures in pediatric traumatic brain injury research

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    This article addresses the need for age-relevant outcome measures for traumatic brain injury (TBI) research and summarizes the recommendations by the inter-agency Pediatric TBI Outcomes Workgroup. The Pediatric Workgroup\u27s recommendations address primary clinical research objectives including characterizing course of recovery from TBI, prediction of later outcome, measurement of treatment effects, and comparison of outcomes across studies. Consistent with other Common Data Elements (CDE) Workgroups, the Pediatric TBI Outcomes Workgroup adopted the standard three-tier system in its selection of measures. In the first tier, core measures included valid, robust, and widely applicable outcome measures with proven utility in pediatric TBI from each identified domain including academics, adaptive and daily living skills, family and environment, global outcome, health-related quality of life, infant and toddler measures, language and communication, neuropsychological impairment, physical functioning, psychiatric and psychological functioning, recovery of consciousness, social role participation and social competence, social cognition, and TBI-related symptoms. In the second tier, supplemental measures were recommended for consideration in TBI research focusing on specific topics or populations. In the third tier, emerging measures included important instruments currently under development, in the process of validation, or nearing the point of published findings that have significant potential to be superior to measures in the core and supplemental lists and may eventually replace them as evidence for their utility emerges

    Quasi-Normal Modes of Stars and Black Holes

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    Perturbations of stars and black holes have been one of the main topics of relativistic astrophysics for the last few decades. They are of particular importance today, because of their relevance to gravitational wave astronomy. In this review we present the theory of quasi-normal modes of compact objects from both the mathematical and astrophysical points of view. The discussion includes perturbations of black holes (Schwarzschild, Reissner-Nordstr\"om, Kerr and Kerr-Newman) and relativistic stars (non-rotating and slowly-rotating). The properties of the various families of quasi-normal modes are described, and numerical techniques for calculating quasi-normal modes reviewed. The successes, as well as the limits, of perturbation theory are presented, and its role in the emerging era of numerical relativity and supercomputers is discussed.Comment: 74 pages, 7 figures, Review article for "Living Reviews in Relativity

    Pathological Computed Tomography Features Associated with Adverse Outcomes after Mild Traumatic Brain Injury:A TRACK-TBI Study with External Validation in CENTER-TBI

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    Importance: A head computed tomography (CT) with positive results for acute intracranial hemorrhage is the gold-standard diagnostic biomarker for acute traumatic brain injury (TBI). In moderate to severe TBI (Glasgow Coma Scale [GCS] scores 3-12), some CT features have been shown to be associated with outcomes. In mild TBI (mTBI; GCS scores 13-15), distribution and co-occurrence of pathological CT features and their prognostic importance are not well understood. Objective: To identify pathological CT features associated with adverse outcomes after mTBI. Design, Setting, and Participants: The longitudinal, observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study enrolled patients with TBI, including those 17 years and older with GCS scores of 13 to 15 who presented to emergency departments at 18 US level 1 trauma centers between February 26, 2014, and August 8, 2018, and underwent head CT imaging within 24 hours of TBI. Evaluations of CT imaging used TBI Common Data Elements. Glasgow Outcome Scale-Extended (GOSE) scores were assessed at 2 weeks and 3, 6, and 12 months postinjury. External validation of results was performed via the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study. Data analyses were completed from February 2020 to February 2021. Exposures: Acute nonpenetrating head trauma. Main Outcomes and Measures: Frequency, co-occurrence, and clustering of CT features; incomplete recovery (GOSE scores <8 vs 8); and an unfavorable outcome (GOSE scores <5 vs ≄5) at 2 weeks and 3, 6, and 12 months. Results: In 1935 patients with mTBI (mean [SD] age, 41.5 [17.6] years; 1286 men [66.5%]) in the TRACK-TBI cohort and 2594 patients with mTBI (mean [SD] age, 51.8 [20.3] years; 1658 men [63.9%]) in an external validation cohort, hierarchical cluster analysis identified 3 major clusters of CT features: contusion, subarachnoid hemorrhage, and/or subdural hematoma; intraventricular and/or petechial hemorrhage; and epidural hematoma. Contusion, subarachnoid hemorrhage, and/or subdural hematoma features were associated with incomplete recovery (odds ratios [ORs] for GOSE scores <8 at 1 year: TRACK-TBI, 1.80 [95% CI, 1.39-2.33]; CENTER-TBI, 2.73 [95% CI, 2.18-3.41]) and greater degrees of unfavorable outcomes (ORs for GOSE scores <5 at 1 year: TRACK-TBI, 3.23 [95% CI, 1.59-6.58]; CENTER-TBI, 1.68 [95% CI, 1.13-2.49]) out to 12 months after injury, but epidural hematoma was not. Intraventricular and/or petechial hemorrhage was associated with greater degrees of unfavorable outcomes up to 12 months after injury (eg, OR for GOSE scores <5 at 1 year in TRACK-TBI: 3.47 [95% CI, 1.66-7.26]). Some CT features were more strongly associated with outcomes than previously validated variables (eg, ORs for GOSE scores <5 at 1 year in TRACK-TBI: neuropsychiatric history, 1.43 [95% CI.98-2.10] vs contusion, subarachnoid hemorrhage, and/or subdural hematoma, 3.23 [95% CI 1.59-6.58]). Findings were externally validated in 2594 patients with mTBI enrolled in the CENTER-TBI study. Conclusions and Relevance: In this study, pathological CT features carried different prognostic implications after mTBI to 1 year postinjury. Some patterns of injury were associated with worse outcomes than others. These results support that patients with mTBI and these CT features need TBI-specific education and systematic follow-up
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