636 research outputs found

    Ecological legacies of drought, fire, and insect disturbance in western North American forests, The

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    Includes bibliographical references.2015 Fall.Temperate forest ecosystems are subject to various disturbances including insect agents, drought and fire, which can have profound effects on the structure of the ecosystem for many years after the event. Impacts of disturbance can vary widely, therefore an understanding of the legacies of an event are critical in the interpretation of contemporary forest patterns and those of the near future. The primary objective of this dissertation was to investigate the ecological legacies of drought, beetle outbreak and ensuing wildfire in two different ecosystems. A secondary objective of my research, data development, was motivated by a lack of available data which precluded ecological investigation of each disturbance. I studied the effects of drought on deciduous and coniferous forest along a forest-shrubland ecotone in the southern portion of the Wyoming Basin Ecoregion. The results show that forests in the region have experienced high levels of cumulative drought related mortality over the last decade. Negative trends were not consistent across forest type or distributed randomly across the study area. The patterns of long-term trends highlight areas of forest that are resistant, persistent or vulnerable to severe drought. In the second thread of my dissertation, I used multiple lines of evidence to retrospectively characterize a landscape scale mountain pine beetle disturbance from the 1970s in Glacier National Park. The lack of spatially explicit data on this disturbance was a major data gap since wildfire had removed some of the evidence from the landscape. I used this information to assess the influence of beetle severity on the burn severity of subsequent wildfires in the decades after the outbreak. Although many factors contribute to burn severity, my results indicate that beetle severity can positively influence burn severity of wildfire. This is likely due to the change in forest structure in the decades after the outbreak and not as a direct result of tree mortality from the outbreak. The long-term perspective of this study suggests that ecological legacies of high severity disturbance may continue to influence subsequent disturbance for many years after the initial event. This work also provides insight on future disturbance interactions associated with the recent mountain pine beetle outbreak that has impacted tens of millions of hectares in western North America over the last two decades

    Posttraumatic ankle arthritis due to a novel Nocardia species

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    Introduction: Nocardial arthritis in immunocompetent patients is rare, and the optimum duration of antimicrobial therapy is unknown, although several months of antibiotic treatment is often recommended. Case report: We here report the first case of human infection with a novel Nocardia sp., summarise the epidemiology of nocardial arthritis and outline the feasibility of relatively short antibiotic treatments after careful surgical drainag

    Range-wide assessment of livestock grazing across the sagebrush biome

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    Domestic livestock grazing occurs in virtually all sagebrush habitats and is a prominent disturbance factor. By affecting habitat condition and trend, grazing influences the resources required by, and thus, the distribution and abundance of sagebrush-obligate wildlife species (for example, sage-grouse Centrocercus spp.). Yet, the risks that livestock grazing may pose to these species and their habitats are not always clear. Although livestock grazing intensity and associated habitat condition may be known in many places at the local level, we have not yet been able to answer questions about use, condition, and trend at the landscape scale or at the range-wide scale for wildlife species. A great deal of information about grazing use, management regimes, and ecological condition exists at the local level (for individual livestock management units) under the oversight of organizations such as the Bureau of Land Management (BLM). However, the extent, quality, and types of existing data are unknown, which hinders the compilation, mapping, or analysis of these data. Once compiled, these data may be helpful for drawing conclusions about rangeland status, and we may be able to identify relationships between those data and wildlife habitat at the landscape scale

    Cross-cultural adaptation, reliability, internal consistency and validation of the Trinity Amputation and Prosthetic Experience Scales-Revised (TAPES-R) for French speaking patients with lower limb amputation

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    AimThe aim of this study was the French cross-cultural adaptation and validation of The Trinity Amputation and Prosthetic Experience Scales-Revised (TAPES-R-F), in a lower limb amputation population. This self-reported multidimensional amputee-specific questionnaire [1] evaluates with 33 items psychosocial adjustment (3 subscales), activity restriction (1 subscale) and satisfaction with prosthesis (2 subscales).Patients and methodsOne hundred and twenty-nine patients with a mean age of 62 years and with lower limb amputations for at least 1 year were recruited in 5 clinical centers. Translation and cross-cultural adaptation were made according to international guidelines. Internal consistency of each subscale was measured with Cronbach's alpha. Test-retest reliability was assessed by intraclass correlation in a sub- group of 24 subjects who completed the TAPES-R twice with an interval of 7 days. Construct validity was estimated through correlations with 2 main components of SF-36 (MCS, PCS). Correlations were also calculated with 3 scales of the Brief Pain Inventory (BPI).ResultsCronbach's alpha was high, ranging from 0.85 to 0.95. Reliability was acceptable to high (ICC=0.72 to 0.91) for all subscales with the exception of the Social adjustment (ICC=0.67) and Adjustment to limitation (ICC=0.42) subscales. The 2 component of SF-36 was significantly correlated with all subscales (PCS: r=0.24 to 0.66); MCS: r=0.30 to 0.58), except with aesthetic satisfaction and adjustment to limitation. Regarding the BPI, significant correlations were found for all subscales (r=–0.20 to –0.68) with the exception of adjustment to limitation. Ceiling or floor effects (>15%) were found for all but Activity Restriction and Functional Satisfaction Scales.DiscussionThe TAPES-R-F has acceptable psychometric properties for most of its subscales. Our results may suggest that the French version is more useful in a population research perspective than in an individual perspective. Other studies are necessary to clarify the role and the psychometric properties of this measurement

    ADC mapping of the aging frontal lobes in mild cognitive impairment

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    Normal aging, leukoaraiosis (LA) and vascular disease particularly involve the human frontal lobes. We decided to investigate a population of elderly patients referred for neuroimaging because of progressive minor cognitive deficits but no dementia. They underwent conventional Magnetic resonance imaging (MRI) using axial T1 and T2-weighted imaging as well as coronal FLAIR sequences in addition to the axial diffusion-weighted MRI. MRI allowed us to differentiate patients with leukoaraïosis (LA+) from those without it (LA-) and mapping of the apparent diffusion coefficient (ADC) to investigate local tissular water motion.We observed an increase in the ADC in all investigated patients with increasing age (r=0.326, p=0.002). This increase was observed in both patients groups (LA+ and LA-) . In addition, the LA+ group had significant higher ADC values than the LA- group after controlling for age (p<0.0001

    Are super-face-recognisers also super-voice-recognisers? Evidence from cross-modal identification tasks

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    Individual differences in face identification ability range from prosopagnosia to super-recognition. The current study examined whether face identification ability predicts voice identification ability (participants: N = 529). Superior-face-identifiers (exceptional at face memory and matching), superior-face-recognisers (exceptional at face memory only), superior-face-matchers (exceptional face matchers only), and controls completed the Bangor Voice Matching Test, Glasgow Voice Memory Test, and a Famous Voice Recognition Test. Meeting predictions, those possessing exceptional face memory and matching skills outperformed typical-range face groups at voice memory and voice matching respectively. Proportionally more super-face-identifiers also achieved our super-voice-recogniser criteria on two or more tests. Underlying cross-modality (voices vs. faces) and cross-task (memory vs. perception) mechanisms may therefore drive superior performances. Dissociations between Glasgow Voice Memory Test voice and bell recognition also suggest voice-specific effects to match those found with faces. These findings have applied implications for policing, particularly in cases when only suspect voice clips are available

    Subcutaneous rupture of the Achilles tendon and ipsilateral fracture of the medial malleolus

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    BACKGROUND: Although ankle fractures and an Achilles tendon rupture are relatively frequent in isolation, their association in the same injury is uncommon. CASE PRESENTATION: A 38 year old male tree surgeon fell six meters from a tree, sustaining a subcutaneous rupture of the Achilles tendon and an ipsilateral closed fracture of the medial malleolus. The injuries were diagnosed following clinical examination and imaging. CONCLUSION: This injury combination is infrequent, and management of the Achilles tendon rupture should take into account the necessity not to secondarily displace the fracture of the medial malleollus

    Acute TNFα levels predict cognitive impairment 6-9 months after COVID-19 infection.

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    A neurocognitive phenotype of post-COVID-19 infection has recently been described that is characterized by a lack of awareness of memory impairment (i.e., anosognosia), altered functional connectivity in the brain's default mode and limbic networks, and an elevated monocyte count. However, the relationship between these cognitive and brain functional connectivity alterations in the chronic phase with the level of cytokines during the acute phase has yet to be identified. Determine whether acute cytokine type and levels is associated with anosognosia and functional patterns of brain connectivity 6-9 months after infection. We analyzed the predictive value of the concentration of acute cytokines (IL-1RA, IL-1β, IL-6, IL-8, IFNγ, G-CSF, GM-CSF) (cytokine panel by multiplex immunoassay) in the plasma of 39 patients (mean age 59 yrs, 38-78) in relation to their anosognosia scores for memory deficits via stepwise linear regression. Then, associations between the different cytokines and brain functional connectivity patterns were analyzed by MRI and multivariate partial least squares correlations for the whole group. Stepwise regression modeling allowed us to show that acute TNFα levels predicted (R &lt;sup&gt;2&lt;/sup&gt; = 0.145; β = -0.38; p = .017) and were associated (r = -0.587; p &lt; .001) with scores of anosognosia for memory deficits observed 6-9 months post-infection. Finally, high TNFα levels were associated with hippocampal, temporal pole, accumbens nucleus, amygdala, and cerebellum connectivity. Increased plasma TNFα levels in the acute phase of COVID-19 predict the presence of long-term anosognosia scores and changes in limbic system functional connectivity

    Brain functional connectivity alterations associated with neuropsychological performance 6-9 months following SARS-CoV-2 infection.

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    Neuropsychological deficits and brain damage following SARS-CoV-2 infection are not well understood. Then, 116 patients, with either severe, moderate, or mild disease in the acute phase underwent neuropsychological and olfactory tests, as well as completed psychiatric and respiratory questionnaires at 223 ± 42 days postinfection. Additionally, a subgroup of 50 patients underwent functional magnetic resonance imaging. Patients in the severe group displayed poorer verbal episodic memory performances, and moderate patients had reduced mental flexibility. Neuroimaging revealed patterns of hypofunctional and hyperfunctional connectivities in severe patients, while only hyperconnectivity patterns were observed for moderate. The default mode, somatosensory, dorsal attention, subcortical, and cerebellar networks were implicated. Partial least squares correlations analysis confirmed specific association between memory, executive functions performances and brain functional connectivity. The severity of the infection in the acute phase is a predictor of neuropsychological performance 6-9 months following SARS-CoV-2 infection. SARS-CoV-2 infection causes long-term memory and executive dysfunctions, related to large-scale functional brain connectivity alterations
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