6,883 research outputs found

    A reduced-reference perceptual image and video quality metric based on edge preservation

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    In image and video compression and transmission, it is important to rely on an objective image/video quality metric which accurately represents the subjective quality of processed images and video sequences. In some scenarios, it is also important to evaluate the quality of the received video sequence with minimal reference to the transmitted one. For instance, for quality improvement of video transmission through closed-loop optimisation, the video quality measure can be evaluated at the receiver and provided as feedback information to the system controller. The original image/video sequence-prior to compression and transmission-is not usually available at the receiver side, and it is important to rely at the receiver side on an objective video quality metric that does not need reference or needs minimal reference to the original video sequence. The observation that the human eye is very sensitive to edge and contour information of an image underpins the proposal of our reduced reference (RR) quality metric, which compares edge information between the distorted and the original image. Results highlight that the metric correlates well with subjective observations, also in comparison with commonly used full-reference metrics and with a state-of-the-art RR metric. © 2012 Martini et al

    Evidence for a pervasive 'idling-mode' activity template in flying and pedestrian insects

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    This is the final version. Available on open access from the Royal Society via the DOI in this recordUnderstanding the complex movement patterns of animals in natural environments is a key objective of 'movement ecology'. Complexity results from behavioural responses to external stimuli but can also arise spontaneously in their absence. Drawing on theoretical arguments about decision-making circuitry, we predict that the spontaneous patterns will be scale-free and universal, being independent of taxon and mode of locomotion. To test this hypothesis, we examined the activity patterns of the European honeybee, and multiple species of noctuid moth, tethered to flight mills and exposed to minimal external cues. We also reanalysed pre-existing data for Drosophila flies walking in featureless environments. Across these species, we found evidence of common scale-invariant properties in their movement patterns; pause and movement durations were typically power law distributed over a range of scales and characterized by exponents close to 3/2. Our analyses are suggestive of the presence of a pervasive scale-invariant template for locomotion which, when acted on by environmental cues, produces the movements with characteristic scales observed in nature. Our results indicate that scale-finite complexity as embodied, for instance, in correlated random walk models, may be the result of environmental cues overriding innate behaviour, and that scale-free movements may be intrinsic and not limited to 'blind' foragers as previously thought.Rothamsted research receives grant aided support from the Biotechnology and Biological Sciences Research Council. S.W. was funded jointly by a grant from BBSRC, Defra, NERC, the Scottish Government and the Wellcome Trust, under the Insect Pollinators Initiative (grant nos. BB/I00097/1). A.J.P. was funded by a BBSRC Doctoral Training Partnership in Food Security awarded to K.W. and J.W.C. H.B.C.J. was funded by a BBSRC Quota studentship awarded to J.W.C. and J.K.

    Behavioural syndrome in a solitary predator is independent of body size and growth rate.

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    Models explaining behavioural syndromes often focus on state-dependency, linking behavioural variation to individual differences in other phenotypic features. Empirical studies are, however, rare. Here, we tested for a size and growth-dependent stable behavioural syndrome in the juvenile-stages of a solitary apex predator (pike, Esox lucius), shown as repeatable foraging behaviour across risk. Pike swimming activity, latency to prey attack, number of successful and unsuccessful prey attacks was measured during the presence/absence of visual contact with a competitor or predator. Foraging behaviour across risks was considered an appropriate indicator of boldness in this solitary predator where a trade-off between foraging behaviour and threat avoidance has been reported. Support was found for a behavioural syndrome, where the rank order differences in the foraging behaviour between individuals were maintained across time and risk situation. However, individual behaviour was independent of body size and growth in conditions of high food availability, showing no evidence to support the state-dependent personality hypothesis. The importance of a combination of spatial and temporal environmental variation for generating growth differences is highlighted

    Older Adult Preferences of Mobile Application Functionality Supporting Medication Self-Management

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    Health systems and insurers alike are increasingly interested in leveraging mHealth (mobile health) tools to support patient health-related behaviors including medication adherence. However, these tools are not widely used by older patients. This study explores patient preferences for functionality in a smartphone application (app) that supports medication self-management among older adults with multiple chronic conditions. We conducted six discussion groups in Chicago, Miami, and Denver (N = 46). English-speaking older adults (55 and older) who owned smartphones and took five or more prescription medicines were invited to participate. Discussions covered familiarity with and use of current apps and challenges with taking multidrug regimens. Participants reviewed a range of possible mobile app functions and were asked to give feedback regarding the acceptability and desirability of each to support medication management. Very few participants (n = 3) reported current use of a mobile app for medication support, although all were receptive. Challenges to medication use were forgetfulness, fear of adverse events, and managing medication information from multiple sources. Desired features included (1) a list and consolidated schedule of medications, (2) identification and warning of unsafemedication interactions, (3) reminder alerts to take medicine, and (4) the ability record when medications were taken. Features relating to refill ordering, pharmacy information, and comparing costs for medication were not considered to be as important for an app

    Health literacy, health status, and healthcare utilization of Taiwanese adults: results from a national survey

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    Abstract Background Low health literacy is considered a worldwide health threat. The purpose of this study is to assess the prevalence and socio-demographic covariates of low health literacy in Taiwanese adults and to investigate the relationships between health literacy and health status and health care utilization. Methods A national survey of 1493 adults was conducted in 2008. Health literacy was measured using the Mandarin Health Literacy Scale. Health status was measured based on self-rated physical and mental health. Health care utilization was measured based on self-reported outpatient clinic visits, emergency room visits, and hospitalizations. Results Approximately thirty percent of adults were found to have low (inadequate or marginal) health literacy. They tended to be older, have fewer years of schooling, lower household income, and reside in less populated areas. Inadequate health literacy was associated with poorer mental health (OR, 0.57; 95% CI, 0.35-0.91). No association was found between health literacy and health care utilization even after adjusting for other covariates. Conclusions Low (inadequate and marginal) health literacy is prevalent in Taiwan. High prevalence of low health literacy is not necessarily indicative of the need for interventions. Systematic efforts to evaluate the impact of low health literacy on health outcomes in other countries would help to illuminate features of health care delivery and financing systems that may mitigate the adverse health effects of low health literacy.http://deepblue.lib.umich.edu/bitstream/2027.42/78252/1/1471-2458-10-614.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78252/2/1471-2458-10-614.pdfPeer Reviewe

    Incidence of pulmonary hypertension and determining factors in patients with systemic sclerosis

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    Objective: The objective of this study was to evaluate the incidence of pulmonary hypertension (PH) and determining factors in patients with systemic sclerosis (SSc) and a DLCO < 60% predicted.Methods:In this bicentric, prospective cohort study, patients with SSc were assessed at baseline and after 3 years clinically including right heart catheterization (RHC). Analysis of determining factors for development of PH was performed using univariate and multivariate analysis.Results:Ninety-six patients with mean pulmonary artery pressure (mPAP) <25 mmHg at baseline were followed 2.95±0.7 (median 3) years. Seventy-one had a second RHC; 18 of the 71 patients (25.3%) developed PH, 5 (7%) a SSc-associated pulmonary arterial hypertension. For patients with mPAP between 21 and 24 mmHg at baseline, the likelihood of presenting with PH as opposed to normal pressures on follow-up was significantly higher (p=0.026). Pulmonary vascular resistance, tricuspid regurgitation velocity, diffusion capacity and size of inferior vena cava at baseline were independent predictors for development of PH during follow-up.Conclusion:In a selected cohort of SSc patients with a DLCO < 60%, pulmonary pressures appear to rise progressively during follow up. In this population using prospective RHC during follow-up it was possible to identify manifest PH in almost 25% of 44 patients. Therefore, regular clinical assessment including RHC might be useful in SSc-patients.Most important findings:In a selected cohort of SSc patients pulmonary pressures appear to rise progressively, leading to a development of manifest PH in 25% within 3 years

    PCV13 induced IgG responses in serum associate with serotype-specific IgG in the lung

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    Pneumococcal conjugate vaccine efficacy is lower for non-invasive pneumonia than invasive disease. In this study, participants were vaccinated with PCV13 or HepA (control). Bronchoalveolar lavage samples were taken between 2-6 months and serum at 4- and 7-weeks post vaccination. In the lung, anti-capsular IgG levels were higher in the PCV13 group compared to control for all serotypes, except 3 and 6B. Systemically, IgG levels were elevated in the PCV group at 4-weeks for all serotypes, except 3. IgG in BAL and serum positively correlated for nearly all serotypes. PCV13 shows poor immunogenicity to serotype 3, implying lack of protective efficacy. Clinical trial registration with ISRCTN: 4534043
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