919 research outputs found

    Interdependence and dynamics of essential services in an extensive risk context: a case study in Montserrat, West Indies

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    The essential services that support urban living are complex and interdependent, and their disruption in disasters directly affects society. Yet there are few empirical studies to inform our understanding of the vulnerabilities and resilience of complex infrastructure systems in disasters. This research takes a systems thinking approach to explore the dynamic behaviour of a network of essential services, in the presence and absence of volcanic ashfall hazards in Montserrat, West Indies. Adopting a case study methodology and qualitative methods to gather empirical data, we centre the study on the healthcare system and its interconnected network of essential services. We identify different types of relationship between sectors and develop a new interdependence classification system for analysis. Relationships are further categorised by hazard conditions, for use in extensive risk contexts. During heightened volcanic activity, relationships between systems transform in both number and type: connections increase across the network by 41%, and adapt to increase cooperation and information sharing. Interconnections add capacities to the network, increasing the resilience of prioritised sectors. This in-depth and context-specific approach provides a new methodology for studying the dynamics of infrastructure interdependence in an extensive risk context, and can be adapted for use in other hazard contexts

    An evidence based ranking system for multiple studies designs for informing public policy. An example using interventions associated with Salmonella in swine.

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    Using the association between feed characteristics and Salmonella prevalence we will present an approach to combining data with multiple outcomes from multiple studies designs. The approach may be a method of informing policy makers in the area of food safety when a large amount of heterogeneous literature is available about a topic. The procedure for a systematic review of the literature was followed until the synthesis component. However, to combine the evidence we modified of the FDA Interim Evidence Ranking System for Scientific Information. Each study was characterized as one of 5 study design types based on evidentiary value. After classification by evidentiary value, the studies were considered collectively to rate the strength of the body of evidence based on quantity and consistency. The quantity ranking considered the number of studies, the number of individuals studied and generalizability to the target population. The consistency ranking considered whether studies with different designs reported similar findings. After ranking the body of evidence, an overall ranking was assigned for the strength of the evidence. The final ranking system had four levels. For example, the highest rank of scientific evidence, reflects a high level of comfort among qualified scientists that the association/relationship is scientifically valid. This level ranked relationship would be considered to have a very low probability of significant new data overturning the conclusion that the relationship is valid or significantly changing the nature of the relationship

    Interventions associated with feeding management practices and feed characteristics, and measures of Salmonella prevalence in live and slaughtered swine: A systematic review and summation of evidence

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    The aim of this review is to evaluate and summarize the evidence for associations between feeding management practices and feed characteristics, and Salmonella prevalence in swine, which may represent opportunities for interventions. Salmonella prevalence in the reviewed literature was measured either by culture or by the presence of antibodies. A systematic review of the area was conducted, the goal being to minimize the impact of bias. Systematic reviews include an assessment of the quality of studies and exclusion of studies that fail to meet standards for published material. The review evaluated evidence for an association between feed withdrawal from swine prior to slaughter, acidification of feed, heat treatment of feed, pellet vs. mash, course vs fine grind, and wet vs. dry. A large number of intervention studies were excluded from the review because they failed to report design features designed to limit the introduction of bias such as randomization and blinding. The majority of studies included were cross sectional studies, however these failed to provide strong evidence of an association because of the potential for confounding and the failure to document a temporal association between exposure to the risk factor and the outcome. The review concluded that title strongest body of work was available for pelleted feed and dry feed, however there was still uncertainty about the situations were this association may be effective. The conclusion was that there should be a low level of comfort among qualified scientists that the claimed association/relationship is scientifically valid. This ranking is primarily based on moderate to low quality studies, or insufficient numbers of tested individuals or herds, resulting in a low degree of confidence that results could be extrapolated to the target population

    Vaccination against Salmonella and the association with measures of Salmonella prevalence in live and slaughtered swine - A systematic review

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    A systematic review was conducted to evaluate the effectiveness of vaccination to reduce Salmonella prevalence in market weight finisher swine. To identify relevant studies, online databases and selected conference proceedings were searched. Two reviewers independently assessed the relevance screening and methodological quality of studies. Data of characteristics of study population, intervention, outcome, statistical analysis, and results were extracted. Four clinical trials and 21 challenge studies were identified for the final review as they described vaccination to reduce Salmonella in swine Present evidence suggests that vaccination is associated with reduced Salmonella prevalence in swine

    Inclusivity in the Education of Scientific Imagination

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    Scientists imagine constantly. They do this when generating research problems, designing experiments, interpreting data, troubleshooting, drafting papers and presentations, and giving feedback. But when and how do scientists learn how to use imagination? Across six years of ethnographic research, it has been found that advanced career scientists feel comfortable using and discussing imagination, while graduate and undergraduate students of science often do not. In addition, members of marginalized and vulnerable groups tend to express negative views about the strength of their own imaginations, and the general usefulness of imagination in science. After introducing these findings and discussing the typical relationship between a scientist and their imagination across a career, we argue that reducing the number or power of active imaginations in science is epistemically counterproductive, and suggest a number of ways to bring imagination back into science in a more inclusive way, especially through courses on imagination for scientists, role models, and exemplar-based learning

    The Role of Imagination in Making Water from Moon Rocks: How Scientists Use Imagination to Break Constraints on Imagination

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    Scientists recognize the necessity of imagination for solving tough problems. But how does the cognitive faculty responsible for daydreaming help in solving scientific problems? Philosophers claim that imagination is informative only when it is constrained to be maximally realistic. However, using a case study from space science, we show that scientists use imagination intentionally to break reality-oriented constraints. To do this well, they first target low-confidence constraints, and then higher-confidence constraints, until a plausible solution is found. This paper exemplifies a new approach to epistemology of imagination that focuses on sets of imaginings (rather than individual imaginings), and responsible (rather than reliable) imaginings

    Energy averages and fluctuations in the decay out of superdeformed bands

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    We derive analytic formulae for the energy average (including the energy average of the fluctuation contribution) and variance of the intraband decay intensity of a superdeformed band. Our results may be expressed in terms of three dimensionless variables: Γ↓/ΓS\Gamma^{\downarrow}/\Gamma_S, ΓN/d\Gamma_N/d, and ΓN/(ΓS+Γ↓)\Gamma_N/(\Gamma_S+\Gamma^{\downarrow}). Here Γ↓\Gamma^{\downarrow} is the spreading width for the mixing of a superdeformed (SD) state ∣0>|0> with the normally deformed (ND) states ∣Q>|Q> whose spin is the same as ∣0>|0>'s. The ∣Q>|Q> have mean level spacing dd and mean electromagnetic decay width ΓN\Gamma_N whilst ∣0>|0> has electromagnetic decay width ΓS\Gamma_S. The average decay intensity may be expressed solely in terms of the variables Γ↓/ΓS\Gamma^{\downarrow}/\Gamma_S and ΓN/d\Gamma_N/d or, analogously to statistical nuclear reaction theory, in terms of the transmission coefficients T0(E)T_0(E) and TNT_N describing transmission from the ∣Q>|Q> to the SD band via ∣0∠|0\angle and to lower ND states. The variance of the decay intensity, in analogy with Ericson's theory of cross section fluctuations depends on an additional variable, the correlation length \Gamma_N/(\Gamma_S+\Gamma^{\downarrow})=\frac{d}{2\pi}T_N/(\Gamma_S+\Gamma^{\d ownarrow}). This suggests that analysis of an experimentally obtained variance could yield the mean level spacing dd as does analysis of the cross section autocorrelation function in compound nuclear reactions. We compare our results with those of Gu and Weidenm\"uller.Comment: revtex4, 14 pages, 4 figures, to appear in Physical Review

    Exploring shared decision making in breast cancer care: A case-based conversation analytic approach

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    Shared decision making (SDM) is acknowledged as the gold standard of healthcare communication, particularly relevant to preference-sensitive care such as breast cancer treatment. However, research on patients’ experiences shows a misalignment between clinicians’ goals and the rhetoric regarding patients’ empowerment during SDM for this treatment. This warrants detailed examination on the conversational dynamics of SDM, and this study aims to identify interactional features and social practices through which SDM is achieved. Fifteen audio recordings from adjuvant treatment breast cancer consultations were examined using the methodology of conversation analysis (CA), and recurrent patterns relevant for understanding SDM were identified. Boundary markers, rhetorical questioning and epistemic markers discouraged a shared orientation to patient participation, reinforcing perceived imbalanced doctor–patient power relations. Cues for SDM such as multi-turn utterances and spaces for transition were presented but not recognised by patients, resulting in sub-optimal two-way discussions about decision making. The findings also reveal that interactional practices were deployed that theoretically should have enabled patients to contribute to SDM. However, in reality these did not result in extended sequences of reciprocated contributions from practitioner and service user. SDM did not happen with the ease implied by current models, and the resultant interactions bore more similarity to expert-led, rather than collaborative, decision makin
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