105 research outputs found

    Cascade Dynamics of Multiplex Propagation

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    Random links between otherwise distant nodes can greatly facilitate the propagation of disease or information, provided contagion can be transmitted by a single active node. However we show that when the propagation requires simultaneous exposure to multiple sources of activation, called multiplex propagation, the effect of random links is just the opposite: it makes the propagation more difficult to achieve. We calculate analytical and numerically critical points for a threshold model in several classes of complex networks, including an empirical social network.Comment: 4 pages, 5 figures, for similar work visit http://hsd.soc.cornell.edu and http://www.imedea.uib.es/physdep

    New Ohio and Indiana Records of Aquatic Insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera: Elmidae, Diptera: Chironomidae)

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    New state records and additional locations for rarely collected species are reported for Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies), Coleoptera: Elmidae (riffle beetles), and Diptera: Chironomidae (chironomids, non-biting midges, midges). These specimen records result primarily from Ohio Environmental Protection Agency biomonitoring of Ohio streams and from records found in the Purdue University Entomological Research Collection and the Illinois Natural History Survey Insect Collection; a few records were derived from material housed in two other collections. New state records for Ohio consist of the mayflies Acentrella rallatoma Burian & Myers, Acerpenna pygmaea (Hagen), Anafroptilum album (McDunnough), Anafroptilum minor group species 1, Anafroptilum minor group species 2, Anafroptilum victoriae (McDunnough), Heterocloeon (Jubilatum) species B McCafferty et al., Heterocloeon (Jubilatum) species D McCafferty et al., Labiobaetis longipalpus (Morihara & McCafferty), Plauditus punctiventris (McDunnough), Ephemera guttulata Pictet, Habrophlebia vibrans Needham, and Anthopotamus verticis (Say); the stonefly Isoperla frisoni Illies; the caddisflies Brachycentrus nigrosoma (Banks), Homoplectra doringa (Milne), Ceraclea nepha (Ross), and Fabria inornata (Banks); the riffle beetle Oulimnius nitidulus (LeConte); and the chironomids Cricotopus (Isocladius) sp. “Ozarks” Epler, Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther. A previous report of the mayfly Macdunnoa persimplex (McDunnough) from the Ohio River, adjacent to Ohio, is substantiated with record data. The caddisfly Goerita betteni Ross is confirmed in Ohio. New state records for Indiana consist of the mayflies Heterocloeon (Jubilatum) species D McCafferty et al. and Leucrocuta walshi (McDunnough) and the chironomids Cricotopus (Isocladius) sp. “Ozarks” and Fittkauimyia sp. [probably F. serta (Roback)]. Recent Indiana records of the mayflies Homoeoneuria ammophila (Spieth) and Pentagenia vittigera (Walsh) are also included because these species are rarely collected and most existing records are old. These records represent significant range extensions north for Cricotopus (Isocladius) sp. “Santa Fe” Epler, Fittkauimyia sp. [probably F. serta (Roback)], Parakiefferiella sp. F Epler, and Saetheria hirta Sæther

    A Retrospective Database Analysis of Neonatal Morbidities to Evaluate a Composite Endpoint for Use in Preterm Labor Clinical Trials

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    Objective To propose and assess a composite endpoint (CE) of neonatal benefit based on neonatal mortality and morbidities by gestational age (GA) for use in preterm labor clinical trials. Study Design A descriptive, retrospective analysis of the Medical University of South Carolina Perinatal Information System database was conducted. Neonatal morbidities were assessed for inclusion in the CE based on clinical significance/risk of childhood neurodevelopmental impairment, frequency, and association with GA in a mother– neonate linked cohort, comprising women with uncomplicated singleton pregnancies delivered at !24 weeks’ GA. Results Among 17,912 mother–neonate pairs, neonates were at a risk of numerous severe but infrequent morbidities. Clinically important, predominantly rare events were combined into a CE comprising neonatal mortality and morbidities, which decreased in frequency with increasing GA. The highest CE frequency occurred at \u3c31 weeks. High frequency of respiratory distress syndrome, bronchopulmonary dysplasia, and sepsis drove the CE. Median length of hospital stay was longer at all GAs in those with the CE compared with those without. Conclusions Descriptive epidemiological assessment and clinical input were used to develop a CE to measure neonatal benefit, comprising clinically meaningful outcomes. These empirical data and CE allowed trials investigating tocolytics to be sized appropriately

    Individualization as driving force of clustering phenomena in humans

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    One of the most intriguing dynamics in biological systems is the emergence of clustering, the self-organization into separated agglomerations of individuals. Several theories have been developed to explain clustering in, for instance, multi-cellular organisms, ant colonies, bee hives, flocks of birds, schools of fish, and animal herds. A persistent puzzle, however, is clustering of opinions in human populations. The puzzle is particularly pressing if opinions vary continuously, such as the degree to which citizens are in favor of or against a vaccination program. Existing opinion formation models suggest that "monoculture" is unavoidable in the long run, unless subsets of the population are perfectly separated from each other. Yet, social diversity is a robust empirical phenomenon, although perfect separation is hardly possible in an increasingly connected world. Considering randomness did not overcome the theoretical shortcomings so far. Small perturbations of individual opinions trigger social influence cascades that inevitably lead to monoculture, while larger noise disrupts opinion clusters and results in rampant individualism without any social structure. Our solution of the puzzle builds on recent empirical research, combining the integrative tendencies of social influence with the disintegrative effects of individualization. A key element of the new computational model is an adaptive kind of noise. We conduct simulation experiments to demonstrate that with this kind of noise, a third phase besides individualism and monoculture becomes possible, characterized by the formation of metastable clusters with diversity between and consensus within clusters. When clusters are small, individualization tendencies are too weak to prohibit a fusion of clusters. When clusters grow too large, however, individualization increases in strength, which promotes their splitting.Comment: 12 pages, 4 figure

    Support for smoke-free policies in the Cyprus hospitality industry

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    Objectives The present study used attitudinal and behavioural indicators to measure support for smoke-free policies among employers and employees in the hospitality industry in Cyprus. Methods A representative sample of 600 participants (95 % response rate) completed anonymous structured questionnaires on demographic variables, smoking status, exposure to second-hand smoke at work and related health beliefs, social norms, and smoke-free policy support. Results Participants were predominantly males (68.3 %), with a mean age of 40 years (SD = 12.69), and 39.7 % were employers/owners of the hospitality venue. Analysis of variance showed that employers and smokers were less supportive of smoke-free policies, as compared to employees and non-smokers. Linear regression models showed that attitudes towards smoke-free policy were predicted by smoking status, SHS exposure and related health beliefs, and social norm variables. Logistic regression analysis showed that willingness to confront a policy violator was predicted by SHS exposure, perceived prevalence of smoker clients, and smoke-free policy attitudes. Conclusions SHS exposure and related health beliefs, and normative factors should be targeted by interventions aiming to promote policy support in the hospitality industry in Cyprus

    Patientâ level Factors and the Quality of Care Delivered in Pediatric Emergency Departments

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    ObjectiveQuality of care delivered to adult patients in the emergency department (ED) is often associated with demographic and clinical factors such as a patient’s race/ethnicity and insurance status. We sought to determine whether the quality of care delivered to children in the ED was associated with a variety of patientâ level factors.MethodsThis was a retrospective, observational cohort study. Pediatric patients (<18 years) who received care between January 2011 and December 2011 at one of 12 EDs participating in the Pediatric Emergency Care Applied Research Network (PECARN) were included. We analyzed demographic factors (including age, sex, and payment source) and clinical factors (including triage, chief complaint, and severity of illness). We measured quality of care using a previously validated implicit review instrument using chart review with a summary score that ranged from 5 to 35. We examined associations between demographic and clinical factors and quality of care using a hierarchical multivariable linear regression model with hospital site as a random effect.ResultsIn the multivariable model, among the 620 ED encounters reviewed, we did not find any association between patient age, sex, race/ethnicity, and payment source and the quality of care delivered. However, we did find that some chief complaint categories were significantly associated with lower than average quality of care, including fever (â 0.65 points in quality, 95% confidence interval [CI] = â 1.24 to â 0.06) and upper respiratory symptoms (â 0.68 points in quality, 95% CI = â 1.30 to â 0.07).ConclusionWe found that quality of ED care delivered to children among a cohort of 12 EDs participating in the PECARN was high and did not differ by patient age, sex, race/ethnicity, and payment source, but did vary by the presenting chief complaint.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142981/1/acem13347_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142981/2/acem13347-sup-0001-DataSupplementS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142981/3/acem13347.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142981/4/acem13347-sup-0002-DataSupplementS2.pd

    24-Karat or fool’s gold? Consequences of real team and co-acting group membership in healthcare organizations

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    Although theory on team membership is emerging, limited empirical attention has been paid to the effects of different types of team membership on outcomes. We propose that an important but overlooked distinction is that between membership of real teams and membership of co-acting groups, with the former being characterized by members who report that their teams have shared objectives, and structural interdependence and engage in team reflexivity. We hypothesize that real team membership will be associated with more positive individual- and organizational-level outcomes. These predictions were tested in the English National Health Service, using data from 62,733 respondents from 147 acute hospitals. The results revealed that individuals reporting the characteristics of real team membership, in comparison with those reporting the characteristics of co-acting group membership, witnessed fewer errors and incidents, experienced fewer work related injuries and illness, were less likely to be victims of violence and harassment, and were less likely to intend to leave their current employment. At the organizational level, hospitals with higher proportions of staff reporting the characteristics of real team membership had lower levels of patient mortality and sickness absence. The results suggest the need to clearly delineate real team membership in order to advance scientific understanding of the processes and outcomes of organizational teamwork
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