940 resultados para home range


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim To examine the effect of climate change on the occurrence and distribution of Pipistrellus nathusii (Nathusius' pipistrelle) in the United Kingdom (UK).Location We modelled habitat and climatic associations of P. nathusii in the UK and applied this model to the species' historical range in continental Europe.Methods A binomial logistic regression model was constructed relating the occurrence of P. nathusii to climate and habitat characteristics using historical species occurrence records (1940-2006) and CORINE land cover data. This model was applied to historical and projected climate data to examine changes in suitable range (1940-2080) of this species. We tested the predictive ability of the model with known records in the UK after 2006 and applied the model to the species' known range in Europe.Results The distribution of P. nathusii was related positively to the area of water bodies, woodland and small areas of urbanization, and negatively related to the area of peat/heathland. Species records were associated with higher minimum temperatures, low seasonal variation in temperature and intermediate rainfall. We found that suitable areas have existed in the UK since the 1940s and that these have expanded. The model had high predictive power when applied to new records after 2006, with a correct classification rate of 70%, estimated by receiver operating characteristic analysis. Based on climate projections, our model suggests a potential twofold increase in the area suitable for P. nathusii in the UK by 2050. The single most influential climate variable contributing to range increase was the projected increase in minimum temperature. When applied to Europe, the model predictions had best predictive capability of known records in western areas of the species' range, where P. nathusii is present during the winter.Main conclusions We show that a mobile, migratory species has adapted its range in response to recent climate change on a continental scale. We believe this may be the first study to demonstrate a case of range change linked to contemporary climate change in a mammal species in Europe.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim We carried out a phylogeographic study across the range of the herbaceous plant species Monotropa hypopitys L. in North America to determine whether its current disjunct distribution is due to recolonization from separate eastern and western refugia after the Last Glacial Maximum (LGM). Location North America: Pacific Northwest and north-eastern USA/south-eastern Canada. Methods Palaeodistribution modelling was carried out to determine suitable climatic regions for M. hypopitys at the LGM. We analysed between 155 and 176 individuals from 39 locations spanning the species' entire range in North America. Sequence data were obtained for the chloroplast rps2 gene (n=168) and for the nuclear ITS region (n=158). Individuals were also genotyped for eight microsatellite loci (n=176). Interpolation of diversity values was used to visualize the range-wide distribution of genetic diversity for each of the three marker classes. Minimum spanning networks were constructed showing the relationships between the rps2 and ITS haplotypes, and the geographical distributions of these haplotypes were plotted. The numbers of genetic clusters based on the microsatellite data were estimated using Bayesian clustering approaches. Results The palaeodistribution modelling indicated suitable climate envelopes for M. hypopitys at the LGM in both the Pacific Northwest and south-eastern USA. High levels of genetic diversity and endemic haplotypes were found in Oregon, the Alexander Archipelago, Wisconsin, and in the south-eastern part of the species' distribution range. Main conclusions Our results suggest a complex recolonization history for M. hypopitys in North America, involving persistence in separate eastern and western refugia. A generally high degree of congruence between the different marker classes analysed indicated the presence of multiple refugia, with at least two refugia in each area. In the west, putative refugia were identified in Oregon and the Alexander Archipelago, whereas eastern refugia may have been located in the southern part of the species' current distribution, as well as in the 'Driftless Area'. These findings are in contrast to a previous study on the related species Orthilia secunda, which has a similar disjunct distribution to M. hypopitys, but which appears to have recolonized solely from western refugia. © 2011 Blackwell Publishing Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

As a clinically complex neurodegenerative disease, Parkinson's disease (PD) requires regular assessment and close monitoring. In our current study, we have developed a home-based tool designed to monitor and assess peripheral motor symptoms. An evaluation of the tool was carried out over a period of ten weeks on ten people with idiopathic PD. Participants were asked to use the tool twice daily over four days, once when their medication was working at its best (

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We introduce an application for the detection of aberrant behaviour within home based environments, with a focus on repetitive actions, which may be present in instance of persons suffering from dementia. Video based analysis has been used to detect the motion of a person within a given scene in addition to tracking them over the time. Detection of repetitive actions has been based on the analysis of a person's trajectory using the principles of signal correlation. Along with the ability to detect repetitive motion the developed approach also has the ability to measure the amount of activity/inactivity within the scene during a given period of time. Our results showed that the developed approach had the ability to detect all patterns in the data set examined with an average accuracy of 96.67%. This work has therefore validated the proposed concept of video based analysis for the detection of repetitive activities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVES: To evaluate the cost-effectiveness of an adapted U.S. model of pharmaceutical care to improve psychoactive prescribing for nursing home residents in Northern Ireland (Fleetwood NI Study).
DESIGN: Economic evaluation alongside a cluster randomized controlled trial.
SETTING: Nursing homes in NI randomized to intervention (receipt of the adapted model of care; n511) or control (usual care continued; n511).
PARTICIPANTS: Residents aged 65 and older who provided informed consent (N5253; 128 intervention, 125 control) and who had full resource use data at 12 months.
INTERVENTION: Trained pharmacists reviewed intervention home residents’ clinical and prescribing information for 12 months, applied an algorithm that guided them in assessing the appropriateness of psychoactive medication, and worked with prescribers (general practitioners) to make changes. The control homes received usual care in which there was no pharmacist intervention.
MEASUREMENTS: The proportion of residents prescribed one or more inappropriate psychoactive medications (according to standardized protocols), costs, and a cost-effectiveness acceptability curve. The latter two outcomes are the focus for this article.
RESULTS: The proportions of residents receiving inappropriate psychoactive medication at 12 months in the intervention and control group were 19.5% and 50.4%, respectively. The mean cost of healthcare resources used per resident per year was $4,923 (95% con?dence interval.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A wide tuning range voltage controlled oscillator (VCO) with novel architecture is proposed in this work. The entire circuit consists of a VCO core, a summing circuit, a single-ended to differential (STD) converter and a buffer amplifier. The VCO core oscillates at half the desired frequency and the second harmonic of the VCO core is extracted by the summing circuit, which is then converted to a differential pair by the STD. The entire VCO circuit operates from 58.85 to 70.85 GHz with 20% frequency tuning range. The measured VCO gain is less than 1.6 GHz/V. The measured phase noise at 3 MHz offset is less than -78 dBc/Hz across the entire tuning range. The differential phase error of the output signals is measured by down converting the VCO output signals to low gigahertz frequency using an on-chip mixer. The measured differential phase error is less than 8°. The VCO circuit, which is constructed using 0.35 µm SiGe technology, occupies 770 × 550 µm2 die area and consumes 62 mA under 3.5 V supply.