1,449 research outputs found
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Changing Climate Drives Divergent and Nonlinear Shifts in Flowering Phenology across Elevations
Climate change is known to affect regional weather patterns and phenology; however, we lack understanding of how climate drives phenological change across local spatial gradients. This spatial variation is critical for determining whether subpopulations and metacommunities are changing in unison or diverging in phenology. Divergent responses could reduce synchrony both within species (disrupting gene flow among subpopulations) and among species (disrupting interspecific interactions in communities). We also lack understanding of phenological change in environments where life history events are frequently aseasonal, such as the tropical, arid, and semi-arid ecosystems that cover vast areas. Using a 33-year-long dataset spanning a 1,267-m semi-arid elevational gradient in the southwestern United States, we test whether flowering phenology diverged among subpopulations within species and among five communities comprising 590 species. Applying circular statistics to test for changes in year-round flowering, we show flowering has become earlier for all communities except at the highest elevations. However, flowering times shifted at different rates across elevations likely because of elevation-specific changes in temperature and precipitation, indicating diverging phenologies of neighboring communities. Subpopulations of individual species also diverged at mid-elevation but converged in phenology at high elevation. These changes in flowering phenology among communities and subpopulations are undetectable when data are pooled across the gradient. Furthermore, we show that nonlinear changes in flowering times over the 33-year record are obscured by traditional calculations of long-term trends. These findings reveal greater spatiotemporal complexity in phenological responses than previously recognized and indicate climate is driving phenological reshuffling across local spatial gradients.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Predicting speciesâspecific responses of fungi to climatic variation using historical records
Although striking changes have been documented in plant and animal phenology over the past century, less is known about how the fungal kingdom's phenology has been changing. A few recent studies have documented changes in fungal fruiting in Europe in the last few decades, but the geographic and taxonomic extent of these changes, the mechanisms behind these changes, and their relationships to climate are not well understood. Here, we analyzed herbarium data of 274 species of fungi from Michigan to test the hypotheses that fruiting times of fungi depend on annual climate and that responses depend on taxonomic and functional groups. We show that the fungal community overall fruits later in warmer and drier years, which has led to a shift toward later fruiting dates for autumnâfruiting species, consistent with existing evidence. However, we also show that these effects are highly variable among species and are partly explained by basic lifeâhistory characteristics. Resulting differences in climate sensitivities are expected to affect community structure as climate changes. This study provides a unique picture of the climate dependence of fungal phenology in North America and an approach for quantifying how individual species and broader fungal communities will respond to ongoing climate change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100145/1/gcb12278.pd
Effects of silviculture on native tree species richness: interactions between management, landscape context and regional climate
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98148/1/jpe12064.pd
Pruritus is a common feature in sheep infected with the BSE agent.
BACKGROUND: The variability in the clinical or pathological presentation of transmissible spongiform encephalopathies (TSEs) in sheep, such as scrapie and bovine spongiform encephalopathy (BSE), has been attributed to prion protein genotype, strain, breed, clinical duration, dose, route and type of inoculum and the age at infection. The study aimed to describe the clinical signs in sheep infected with the BSE agent throughout its clinical course to determine whether the clinical signs were as variable as described for classical scrapie in sheep. The clinical signs were compared to BSE-negative sheep to assess if disease-specific clinical markers exist.
RESULTS: Forty-seven (34%) of 139 sheep, which comprised 123 challenged sheep and 16 undosed controls, were positive for BSE. Affected sheep belonged to five different breeds and three different genotypes (ARQ/ARQ, VRQ/VRQ and AHQ/AHQ). None of the controls or BSE exposed sheep with ARR alleles were positive. Pruritus was present in 41 (87%) BSE positive sheep; the remaining six were judged to be pre-clinically infected. Testing of the response to scratching along the dorsum of a sheep proved to be a good indicator of clinical disease with a test sensitivity of 85% and specificity of 98% and usually coincided with weight loss. Clinical signs that were displayed significantly earlier in BSE positive cases compared to negative cases were behavioural changes, pruritic behaviour, a positive scratch test, alopecia, skin lesions, teeth grinding, tremor, ataxia, loss of weight and loss of body condition. The frequency and severity of each specific clinical sign usually increased with the progression of disease over a period of 16-20 weeks.
CONCLUSION: Our results suggest that BSE in sheep presents with relatively uniform clinical signs, with pruritus of increased severity and abnormalities in behaviour or movement as the disease progressed. Based on the studied sheep, these clinical features appear to be independent of breed, affected genotype, dose, route of inoculation and whether BSE was passed into sheep from cattle or from other sheep, suggesting that the clinical phenotype of BSE is influenced by the TSE strain more than by other factors. The clinical phenotype of BSE in the genotypes and breed studied was indistinguishable from that described for classical scrapie cases
Plant invasions are context-dependent: Multiscale effects of climate, human activity and habitat
ABSTRACT Aim Understanding the conditions that promote biological invasions is a critical step to developing successful management strategies. However, the level of invasion is affected by complex interactions among environmental factors that might change across habitats and regions making broad generalizations uninformative for management. We aimed to quantify the context-dependent association of climate and human activity at landscape scale (i.e. disturbance and propagule pressure) with the level of plant invasion at local scale across different stages of invasion, habitat types and bioclimatic regions. Location Mainland Spain. Methods Based on an extensive database of vegetation plots (~50,000), we used hierarchical Bayesian models to test how climate and human activity at a landscape scale (i.e. land-cover variables) are associated with establishment (i.e. presence) and dominance (i.e. relative species richness and abundance in invaded plots) of non-native plants across nine habitat types and three bioclimatic regions. Results The association of climate with establishment and dominance of nonnative plants varied depending on habitat type but not bioclimatic region. These associations also varied depending on the stage of invasion under consideration. Establishment of non-native species was more likely close to the coast, while their dominance increased in wet and warm continental areas. Human activity variables were associated with establishment and dominance similarly across bioclimatic regions. Non-native species establishment and abundance peaked in human-altered landscapes. Different habitats showed different susceptibilities to establishment versus dominance by non-native species (e.g. woodlands had medium levels of establishment, but very low dominance). Main conclusions This study highlights how complex interactions among climate, human activity and habitats can determine patterns of invasions across broad landscapes. Successful management of plant invasions will depend on understanding these context-dependent effects across habitats at the different stages of the invasion process
Electric Ground Support Equipment Advanced Battery Technology Demonstration Project at the Ontario Airport
The intent of the electric Ground Support Equipment (eGSE) demonstration is to evaluate the day-to-day vehicle performance of electric baggage tractors using two advanced battery technologies to demonstrate possible replacements for the flooded lead-acid (FLA) batteries utilized throughout the industry. These advanced battery technologies have the potential to resolve barriers to the widespread adoption of eGSE deployment. Validation testing had not previously been performed within fleet operations to determine if the performance of current advanced batteries is sufficient to withstand the duty cycle of electric baggage tractors. This report summarizes the work performed and data accumulated during this demonstration in an effort to validate the capabilities of advanced battery technologies. This report summarizes the work performed and data accumulated during this demonstration in an effort to validate the capabilities of advanced battery technologies. The demonstration project also grew the relationship with Southwest Airlines (SWA), our demonstration partner at Ontario International Airport (ONT), located in Ontario, California. The results of this study have encouraged a proposal for a future demonstration project with SWA
Perceptions of Community Involvement in the Peruvian Mental Health Reform Process Among Clinicians and Policy-Makers: A Qualitative Study
Background: The global burden of mental health conditions has led to the implementation of new models of care for persons with mental illness. Recent mental health reforms in Peru include the implementation of a community mental health model (CMHM) that, among its core objectives, aims to provide care in the community through specialized facilities, the community mental health centers (CMHCs). Community involvement is a key component of this model. This study aims to describe perceptions of community engagement activities in the current model of care in three CMHCs and identify barriers and potential solutions to implementation.Methods: A qualitative research study using in-depth semi-structured interviews with clinicians from three CMHCs and with policy-makers involved in the implementation of the mental health reforms was conducted in two regions of Peru. The interviews, conducted in Spanish, were digitally recorded with consent, transcribed and analyzed using principles of grounded theory applying a framework approach. Community engagement activities are described at different stages of patient care.Results: Twenty-five full-time employees (17 women, 8 men) were interviewed, of which 21 were clinicians (diverse health professions) from CMHCs, and 4 were policy-makers. Interviews elucidated community engagement activities currently being utilized including: (1) employing community mental health workers (CMHWs); (2) home visits; (3) psychosocial clubs; (4) mental health workshops and campaigns; and (5) peer support groups. Inadequate infrastructure and financial resources, lack of knowledge about the CMHM, poorly defined catchment areas, stigma, and inadequate productivity approach were identified as barriers to program implementation. Solutions suggested by participants included increasing knowledge and awareness about mental health and the new model, implementation of peer-training, and improving productivity evaluation and research initiatives.Conclusion: Community engagement activities are being conducted in Peru as part of a new model of care. However, their structure, frequency, and content are perceived by clinicians and policy-makers as highly variable due to a lack of consistent training and resources across CMHCs. Barriers to implementation should be quickly addressed and potential solutions executed, so that scale-up best optimizes the utilization of resources in the implementation process
Beyond seasonal climate: statistical estimation of phenological responses to weather
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117250/1/eap20142471793.pd
Beyond seasonal climate: statistical estimation of phenological responses to weather
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117250/1/eap20142471793.pd
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Enhancing the quality of international orthopedic medical mission trips using the blue distinction criteria for knee and hip replacement centers
Background: Several organizations seek to address the growing burden of arthritis in developing countries by providing total joint replacements (TJR) to patients with advanced arthritis who otherwise would not have access to these procedures. Because these mission trips operate in resource poor environments, some of the features typically associated with high quality care may be difficult to implement. In the U.S., many hospitals that perform TJRs use the Blue Cross/Shieldâs Blue Distinction criteria as benchmarks of high quality care. Although these criteria were designed for use in the U.S., we applied them to Operation Walk (Op-Walk) Bostonâs medical mission trip to the Dominican Republic. Evaluating the program using these criteria illustrated that the program provides high quality care and, more importantly, helped the program to find areas of improvement. Methods: We used the Blue Distinction criteria to determine if Op-Walk Boston achieves Blue Distinction. Each criterion was grouped according to the four categories included in the Blue Distinction criteriaâ âgeneral and administrativeâ, âstructureâ, âprocessâ, or âoutcomes and volumeâ. Full points were given for criteria that the program replicates entirely and zero points were given for criteria that are not replicated entirely. Of the non-replicated criteria, Op-Walk Bostonâs clinical and administrative teams were asked if they compensate for failure to meet the criterion, and they were also asked to identify barriers that prevent them from meeting the criterion. Results: Out of 100 possible points, the program received 71, exceeding the 60-point threshold needed to qualify as a Blue Distinction center. The program met five out of eight ârequiredâ criteria and 11 out of 19 âinformationalâ criteria. It scored 14/27 in the âgeneralâ category, 30/36 in the âstructureâ category, 17/20 in the âprocessâ category, and 10/17 in the âoutcomes and volumeâ category. Conclusion: Op-Walk Boston qualified for Blue Distinction. Our analysis highlights areas of programmatic improvement and identifies targets for future quality improvement initiatives. Additionally, we note that many criteria can only be met by hospitals operating in the U.S. Future work should therefore focus on creating criteria that are applicable to TJR mission trips in the context of developing countries
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