165 resultados para Noise barriers.
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Performed by Ensemble String Noise at PIANOS, NYC.
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When a collection of phenotypically diverse organisms compete with each other for limited resources, the population can evolve into tightly localised clusters. Past studies have neglected the effects of demographic noise and studied the population on a macroscopic scale, where cluster formation is found to depend on the shape of the curve describing the decline of competition strength with phenotypic distance. Here we show how including the effects of demographic noise leads to a radically different conclusion. Two situations are identified: a weak-noise regime in which the population exhibits patterns of fluctuation around the macroscopic description, and a strong-noise regime where clusters appear spontaneously even in the case that all organisms have equal fitness. editor's choice Copyright (C) EPLA, 2012
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We outline our techniques to characterise photospheric granulation as an astrophysical noise source. A four component parameterisation of granulation is developed that can be used to reconstruct stellar line asymmetries and radial velocity shifts due to photospheric convective motions. The four components are made up of absorption line profiles calculated for granules, magnetic intergranular lanes, non-magnetic intergranular lanes, and magnetic bright points at disc centre. These components are constructed by averaging Fe I $6302 \mathrm{\AA}$ magnetically sensitive absorption line profiles output from detailed radiative transport calculations of the solar photosphere. Each of the four categories adopted are based on magnetic field and continuum intensity limits determined from examining three-dimensional magnetohydrodynamic simulations with an average magnetic flux of $200 \mathrm{G}$. Using these four component line profiles we accurately reconstruct granulation profiles, produced from modelling 12 x 12 Mm$^2$ areas on the solar surface, to within $\sim \pm$ 20 cm s$^{-1}$ on a $\sim$ 100 m s$^{-1}$ granulation signal. We have also successfully reconstructed granulation profiles from a $50 \mathrm{G}$ simulation using the parameterised line profiles from the $200 \mathrm{G}$ average magnetic field simulation. This test demonstrates applicability of the characterisation to a range of magnetic stellar activity levels.
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The performance of exchange and correlation (xc) functionals of the generalized gradient approximation (GGA) type and of the meta-GGA type in the calculation of chemical reactions is related to topological features of the electron density which, in turn, are connected to the orbital structure of chemical bonds within the Kohn-Sham (KS) theory. Seventeen GGA and meta-GGA xc functionals are assessed for 15 hydrogen abstraction reactions and 3 symmetrical S(N)2 reactions. Systems that are problematic for standard GGAs characteristically have enhanced values of the dimensionless gradient argument s(sigma)(2) with local maxima in the bonding region. The origin of this topological feature is the occupation of valence KS orbitals with an antibonding or essentially nonbonding character. The local enhancement of s(sigma)(2) yields too negative exchange-correlation energies with standard GGAs for the transition state of the S(N)2 reaction, which leads to the reduced calculated reaction barriers. The unwarranted localization of the effective xc hole of the standard GGAs, i.e., the nondynamical correlation that is built into them but is spurious in this case, wields its effect by their s(sigma)(2) dependence. Barriers are improved for xc functionals with the exchange functional OPTX as x component, which has a modified dependence on s(sigma)(2). Standard GGAs also underestimate the barriers for the hydrogen abstraction reactions. In this case the barriers are improved by correlation functionals, such as the Laplacian-dependent (LAP3) functional, which has a modified dependence on the Coulomb correlation of the opposite- and like-spin electrons. The best overall performance is established for the combination OLAP3 of OPTX and LAP3.
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OBJECTIVE: To assess challenges in providing palliative care in long-term care (LTC) facilities from the perspective of medical directors. DESIGN: Cross-sectional mailed survey. A questionnaire was developed, reviewed, pilot-tested, and sent to 450 medical directors representing 531 LTC facilities. Responses were rated on 2 different 5-point scales. Descriptive analyses were conducted on all responses. SETTING: All licensed LTC facilities in Ontario with designated medical directors. PARTICIPANTS: Medical directors in the facilities. MAIN OUTCOME MEASURES: Demographic and practice characteristics of physicians and facilities, importance of potential barriers to providing palliative care, strategies that could be helpful in providing palliative care, and the kind of training in palliative care respondents had received. RESULTS: Two hundred seventy-five medical directors (61%) representing 302 LTC facilities (57%) responded to the survey. Potential barriers to providing palliative care were clustered into 3 groups: facility staff's capacity to provide palliative care, education and support, and the need for external resources. Two thirds of respondents (67.1%) reported that inadequate staffing in their facilities was an important barrier to providing palliative care. Other barriers included inadequate financial reimbursement from the Ontario Health Insurance Program (58.5%), the heavy time commitment required (47.3%), and the lack of equipment in facilities (42.5%). No statistically significant relationship was found between geographic location or profit status of facilities and barriers to providing palliative care. Strategies respondents would use to improve provision of palliative care included continuing medical education (80.0%), protocols for assessing and monitoring pain (77.7%), finding ways to increase financial reimbursement for managing palliative care residents (72.1%), providing educational material for facility staff (70.7%), and providing practice guidelines related to assessing and managing palliative care patients (67.8%). CONCLUSION: Medical directors in our study reported that their LTC facilities were inadequately staffed and lacked equipment. The study also highlighted the specialized role of medical directors, who identified continuing medical education as a key strategy for improving provision of palliative care.
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Aim. This paper is a report of a study to explore link nurses' views and experiences regarding the development, barriers and facilitators to the implementation of the role in palliative care in the nursing home.
Background. The delivery of palliative care in nursing homes is widely advocated; one approach is to develop the link nurse role to cascade good practice and training to nurses and other care staff to enhance patient care.
Method. A descriptive qualitative study was conducted with a purposive sample of 14 link nurses from 10 nursing homes in Northern Ireland during 2006. Three focus groups, composed of all Registered Nurses currently acting as link nurses in their nursing homes participated, and the data were audio recorded, fully transcribed and content analysed.
Findings. The link nurse system shows potential to enhance palliative care within nursing homes. However, link nurses experienced a number of difficulties in implementing education programmes. Facilitators of the role included external support, monthly meetings, access to a resource file and peer support among link nurses themselves. Lack of management support, a transient workforce and lack of adequate preparation for link nurses were barriers to fulfilling this role.
Conclusion. Whilst palliative care link nurses can improve care for residents in nursing homes, consideration must be given to overcome the types of barriers identified in order to enable the link nurse system to function effectively. © 2008 The Authors.
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Nursing plays a key role in the coordination and delivery of palliative care services in rural settings. The purpose of this study is to identify barriers and enablers to providing palliative care in rural communities from a nursing perspective. This study utilized a qualitative descriptive design. Findings highlighted that the remoteness, limited access to resources and professional practice barriers created challenges for nurses as they tried to provide quality palliative care to their clients. System-related barriers were identified and included: lack of services, funding issues, and poor continuity of care. Despite these barriers, nurses drew from supports to optimize palliative care such as using a team approach to care, centers, utilizing local case managers and informal community members, and using palliative care resources. These results may help inform policy decisions around the needs of nurses who practice in rural settings to provide quality care to individuals who are dying and their families.
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Temporal dynamics and speaker characteristics are two important features of speech that distinguish speech from noise. In this paper, we propose a method to maximally extract these two features of speech for speech enhancement. We demonstrate that this can reduce the requirement for prior information about the noise, which can be difficult to estimate for fast-varying noise. Given noisy speech, the new approach estimates clean speech by recognizing long segments of the clean speech as whole units. In the recognition, clean speech sentences, taken from a speech corpus, are used as examples. Matching segments are identified between the noisy sentence and the corpus sentences. The estimate is formed by using the longest matching segments found in the corpus sentences. Longer speech segments as whole units contain more distinct dynamics and richer speaker characteristics, and can be identified more accurately from noise than shorter speech segments. Therefore, estimation based on the longest recognized segments increases the noise immunity and hence the estimation accuracy. The new approach consists of a statistical model to represent up to sentence-long temporal dynamics in the corpus speech, and an algorithm to identify the longest matching segments between the noisy sentence and the corpus sentences. The algorithm is made more robust to noise uncertainty by introducing missing-feature based noise compensation into the corpus sentences. Experiments have been conducted on the TIMIT database for speech enhancement from various types of nonstationary noise including song, music, and crosstalk speech. The new approach has shown improved performance over conventional enhancement algorithms in both objective and subjective evaluations.
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Environmental Psychology has typically considered noise as pollution and focused upon its negative impact. However, recent research in psychology and anthropology indicates the experience of noise as aversive depends upon the meanings with which it is attributed. Moreover, such meanings seem to be dependent on the social context. Here we extend this research through studying the aural experience of a religious festival in North India which is characterised by loud, continuous and cacophonous noise. Reporting an experiment and semi-structured interviews, we show that loud noise is experienced as pleasant or unpleasant according to the meanings attributed to it. Specifically, the experiment shows the same noise is experienced more positively (and listened to longer) when attributed to the festival rather than to a non-festival source. In turn, the qualitative data show that within the Mela, noises judged as having a religious quality are reported as more positive than noises that are not. Moreover, the qualitative data suggest a key factor in the evaluation of noise is our participants’ social identities as pilgrims. This identity provides a framework for interpreting the auditory environment and noises judged as intruding into their religious experience were judged negatively, whereas noises judged as contributing to their religious experience were judged more positively. Our findings therefore point to the ways in which our social identities are implicated in the process of attributing meaning to the auditory environment.
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While there is evidence of the factors influencing the healthfulness of consumers' food choice, little is known about how consumers perceive the healthfulness of their shopping. This study aimed to explore consumers' perceptions of, and identify barriers to, conducting a healthful shop. Using a qualitative approach, consisting of an accompanied shop and post-shop telephone interview, 50 grocery shoppers were recruited. Results showed that consumers used three criteria to identify a healthful shop: (1) inclusion of healthful foods; (2) avoidance or restriction of particular foods; and (3) achieving a balance between healthful and unhealthful foods. Those who take a balanced approach employ a more holistic approach to their diet while those who avoid or include specific foods may be setting criteria to purchase only certain types of food. The effectiveness of any of these strategies in improving healthfulness is still unclear and requires further investigation. Two barriers to healthful shopping were: (i) lack of self-efficacy in choosing, preparing and cooking healthful foods and (ii) conflicting needs when satisfying self and others. This highlights the need for interventions targeted at building key food skills and for manufacturers to make healthful choices more appealing. (C) 2013 Elsevier Ltd. All rights reserved.
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Background: Given the worldwide prevalence of overweight and obesity, there is a clear need for meaningful practical healthy eating advice - not only in relation to food choice, but also on appropriate food portion sizes. As the majority of portion size research to date has been overwhelmingly quantitative in design, there is a clear need to qualitatively explore consumers’ views in order to fully understand how food portion size decisions are made. Using qualitative methodology this present study aimed to explore consumers’ views about factors influencing their portion size selection and consumption and to identify barriers to appropriate portion size control.
Methods: Ten focus groups with four to nine participants in each were formed with a total of 66 persons (aged 19–64 years) living on the island of Ireland. The semi-structured discussions elicited participants’ perceptions of suggested serving size guidance and explored the influence of personal, social and environmental factors on their food portion size consumption. Audiotapes of the discussions were professionally transcribed verbatim, loaded into NVivo 9, and analysed using an inductive thematic analysis procedure.
Results: The rich descriptive data derived from participants highlight that unhealthy portion size behaviors emanate from various psychological, social and behavioral factors. These bypass reflective and deliberative control, and converge to constitute significant barriers to healthy portion size control. Seven significant barriers to healthy portion size control were apparent: (1) lack of clarity and irrelevance of suggested serving size guidance; (2) guiltless eating; (3) lack of self-control over food cues; (4) distracted eating; (5) social pressures; (6) emotional eating rewards;
and (7) quantification habits ingrained from childhood.
Conclusions: Portion size control strategies should empower consumers to overcome these effects so that the consumption of appropriate food portion sizes becomes automatic and habitual.
Keywords: Food portion size, Barriers, Obesity, Consumers, Qualitative study. © 2013 Spence et al.; licensee BioMed Central Ltd