327 research outputs found
Informal Helping Networks and Social Service Changes: A Community Perspective
Interviews with 112 household respondents and 58 social service agency directors in three ethnically and racially distinct Chicago neighborhoods provided a comprehensive assessment of -- household helping relationships in a community context. Reliance on informal helping greatly exceeded use of formal agencies at the household level. Households were twice as likely to give help as receive it in a complex variety of ways, while agencies struggled to add new functional programs in a time of retrenchment. What households gave and got did not overlap with agency programs in any coherent way. Further, household respondents and agency directors disagreed in their perceptions of community needs. Households wanted employment and general city services, while agency officials emphasized human services. In effect, efforts to tie formal and informal helping relationships together at a community scale will have to respect the complexity and reciprocity of informal helping by reformulating how the needy are identified, emphasizing reciprocity versus expertise in helping and expanding what presently count as program needs to include a wider range of services
Effectiveness of intensive medical therapy in type B aortic dissection: A single-center experience
ObjectiveAlthough the mainstay of managing acute descending thoracic aortic dissection (ADTAD) remains medical, certain patients will require emergency surgery for complications of rupture or ischemia. This study evaluates factors that affect outcome and determines which patients previously treated surgically would have been eligible for endovascular repair.MethodsA single-institution retrospective study was conducted of patients who presented with clinical signs of ADTAD that was confirmed by magnetic resonance angiography (MRA) or computed tomography (CT). All patients were admitted to the intensive care unit (ICU) and medically managed to maintain systolic blood pressure <120 mm Hg and heart rate <70 beats/min. Two treatment groups were identified: group 1 received medical treatment only; group 2 received medical treatment plus emergency surgery. Patient demographic and clinical data were correlated with 30-day group mortality and morbidity and need for emergency surgery. The MRA and CT scan images of group 2 were retrospectively reviewed to determine if currently available endovascular treatment could have been done. The Fisher exact test was used to compare between the groups, and P < .05 was considered significant.ResultsBetween 1991 and 2005, 83 patients (55 men) were treated for ADTAD. The mean age was 67 years (range, 38 to 85). Sixty-eight patients (82%) had hypertension, three (3.6%) had Marfan syndrome, and 51 (62%) were smokers. Twenty-five (32%) of the patients were receiving β-blocker therapy before the onset of their symptoms. Back pain was the most common initial symptom (72.2%). Emergency surgery was required in 19 patients (23%): 12 for rupture or impending rupture, four for mesenteric ischemia, and three for lower extremity ischemia. The need for emergency surgery was significantly higher in smokers (P = .03), in patients >70 years old (P = .035), and in patients who were not receiving β-blocker therapy before the onset of symptoms (P = .023). The combined overall morbidity rate was 33%, and the mortality rate was 9.6%. Morbidity in group 2 was 64% and significantly higher than the 23% in group 1 (P = .00227). The mortality rate was also higher in group 2 at 31.5% compared with group 1 at 1.6% (P = .0004). Factors affecting the overall mortality included age >70 years (P = .057), previous abdominal aortic aneurysm repair (P = .018), tobacco use (P = .039), and the presence of leg pain at initial presentation (P = .013). As determined from the review of radiologic data, 11 of 13 patients with scans available for review in group 2 could have been treated with currently available endovascular grafts.ConclusionsIntensive medical therapies are effective in preventing early mortality associated with ADTAD. Predictably, the need for emergency surgery carries a high morbidity and mortality rate. Most patients in this series requiring emergency surgery could have been candidates for endovascular therapy had it been available
Point singularities and suprathreshold stochastic resonance in optimal coding
Motivated by recent studies of population coding in theoretical neuroscience,
we examine the optimality of a recently described form of stochastic resonance
known as suprathreshold stochastic resonance, which occurs in populations of
noisy threshold devices such as models of sensory neurons. Using the mutual
information measure, it is shown numerically that for a random input signal,
the optimal threshold distribution contains singularities. For large enough
noise, this distribution consists of a single point and hence the optimal
encoding is realized by the suprathreshold stochastic resonance effect.
Furthermore, it is shown that a bifurcational pattern appears in the optimal
threshold settings as the noise intensity increases. Fisher information is used
to examine the behavior of the optimal threshold distribution as the population
size approaches infinity.Comment: 11 pages, 3 figures, RevTe
Measuring quality of life for an economic evaluation of aphasia: First steps
Health economists typically use the Quality Adjusted Life Year (QALY) when conducting economic evaluations of healthcare investments. We have begun investigating methods to obtain QALYs for aphasia by developing a pictographic version of the Time Trade-Off methodology (picTTO) in an attempt to circumvent language barriers. A convenience sample of 50 adults with aphasia participated in reliability and validity testing of the picTTO. Analysis suggests that while the picTTO itself has face validity, results demonstrated poor to moderate test-retest reliability which we plan to improve by optimizing the study design
Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster
BackgroundWhen organisms are attacked by multiple natural enemies, the evolution of a resistance mechanism to one natural enemy will be influenced by the degree of cross-resistance to another natural enemy. Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another. Using Drosophila melanogaster, an important model system for the evolution of invertebrate immunity, we test for the existence of cross-resistance against parasites and pathogens, at both a phenotypic and evolutionary level.MethodsWe used a field strain of D. melanogaster to test whether surviving parasitism by the parasitoid Asobara tabida has an effect on the resistance against Beauveria bassiana, an entomopathogenic fungus; and whether infection with the microsporidian Tubulinosema kingi has an effect on the resistance against A. tabida. We used lines selected for increased resistance to A. tabida to test whether increased parasitoid resistance has an effect on resistance against B. bassiana and T. kingi. We used lines selected for increased tolerance against B. bassiana to test whether increased fungal resistance has an effect on resistance against A. tabida.Results/ConclusionsWe found no positive cross-resistance or trade-offs in the resistance to parasites and pathogens. This is an important finding, given the use of D. melanogaster as a model system for the evolution of invertebrate immunity. The lack of any cross-resistance to parasites and pathogens, at both the phenotypic and the evolutionary level, suggests that evolution of resistance against one class of natural enemies is largely independent of evolution of resistance against the other
The effect of digital signage on shoppers' behavior: the role of the evoked experience
This paper investigates the role of digital signage as experience provider in retail spaces. The findings of a survey-based field experiment demonstrate that digital signage content high on sensory cues evokes affective experience and strengthens customers’ experiential processing route. In contrast, digital signage messages high on “features and benefits” information evoke intellectual experience and strengthen customers’ deliberative processing route. The affective experience is more strongly associated with the attitude towards the ad and the approach behavior towards the advertiser than the intellectual experience. The effect of an ad high on sensory cues on shoppers’ approach to the advertiser is stronger for first-time shoppers, and therefore important in generating loyalty. The findings indicate that the design of brand-related informational cues broadcast over digital in-store monitors affects shoppers’ information processing. The cues evoke sensory and affective experiences and trigger deliberative processes that lead to attitude construction and finally elicit approach behavior towards the advertisers
Interactions between downslope flows and a developing cold-air pool
A numerical model has been used to characterize the development of a region of enhanced cooling in an alpine valley with a width of order (Formula presented.) km, under decoupled stable conditions. The region of enhanced cooling develops largely as a region of relatively dry air which partitions the valley atmosphere dynamics into two volumes, with airflow partially trapped within the valley by a developing elevated inversion. Complex interactions between the region of enhanced cooling and the downslope flows are quantified. The cooling within the region of enhanced cooling and the elevated inversion is almost equally partitioned between radiative and dynamic effects. By the end of the simulation, the different valley atmospheric regions approach a state of thermal equilibrium with one another, though this cannot be said of the valley atmosphere and its external environment.Peer reviewe
Developing accessible, pictorial versions of health-related quality of life instruments suitable for economic evaluation: a report of preliminary studies conducted in Canada and the United Kingdom
A key component of the current framework for economic evaluation is the measurement and valuation of health outcomes using generic preference-based health-related quality of life (HRQoL) instruments. In 2015, a research synthesis reported the absence of conceptual and empirical research regarding the appropriateness of current preference-based instruments for people with aphasia – a disorder affecting the use and understanding of language – and suggested the development and validation of an accessible, pictorial variant could be an appropriate direction for further research. This paper describes the respective rationale and development process for each of three preliminary studies that have been undertaken to develop pictorial variants of two widely-used preference-based HRQoL instruments (EQ-5D-3L and EQ-5D-5L). The paper also proposes next steps for this program of research, drawing on the lessons learned from the preliminary work and the demand for a pictorial preference-based instrument in the research community. Guidance for the use of the preliminary, pictorial instruments is also provided
Pollutant dispersion in a developing valley cold-air pool
Pollutants are trapped and accumulate within cold-air pools, thereby affecting air quality. A numerical model is used to quantify the role of cold-air-pooling processes in the dispersion of air pollution in a developing cold-air pool within an alpine valley under decoupled stable conditions. Results indicate that the negatively buoyant downslope flows transport and mix pollutants into the valley to depths that depend on the temperature deficit of the flow and the ambient temperature structure inside the valley. Along the slopes, pollutants are generally entrained above the cold-air pool and detrained within the cold-air pool, largely above the ground-based inversion layer. The ability of the cold-air pool to dilute pollutants is quantified. The analysis shows that the downslope flows fill the valley with air from above, which is then largely trapped within the cold-air pool, and that dilution depends on where the pollutants are emitted with respect to the positions of the top of the ground-based inversion layer and cold-air pool, and on the slope wind speeds. Over the lower part of the slopes, the cold-air-pool-averaged concentrations are proportional to the slope wind speeds where the pollutants are emitted, and diminish as the cold-air pool deepens. Pollutants emitted within the ground-based inversion layer are largely trapped there. Pollutants emitted farther up the slopes detrain within the cold-air pool above the ground-based inversion layer, although some fraction, increasing with distance from the top of the slopes, penetrates into the ground-based inversion layer.Peer reviewe
Why Are Regulations Changed? A Parcel Analysis of Upzoning in Los Angeles
Planners, officials, and neighborhood groups often debate zoning changes, yet there is little empirical evidence explaining why zoning and other land use regulations are changed. I use logistic regression models to examine density-enabling rezoning (“upzoning”) in Los Angeles. I find that upzoning occurs where there are development opportunities combined with limited political resistance. Upzoning is most likely on well-located parcels zoned for low-intensity, nonresidential uses. Meanwhile, homeowners—and particularly homeowners with access to valuable amenities—are associated with regulatory stasis. I conclude by recommending strategies for addressing homeowners’ concerns about higher density housing
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