496 research outputs found

    Temporal Trends in Human Vulnerability to Excessive Heat

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    Over recent decades, studies have examined various morbidity and mortality outcomes associated with heat exposure. This review explores the collective knowledge of the temporal trends of heat on human health, with regard to the hypothesis that humans are less vulnerable to heat events presently than in the past. Using Web of Science and Scopus, the authors identified all peer-reviewed articles that contained keywords on human impact (e.g. mortality, morbidity) and meteorological component (e.g. heat, heatwave). After sorting, a total of 71 articles, both case studies and epidemiological studies, contained explicit assessments of temporal trends in human vulnerability, and thus were used in this review. Most of the studies utilized mortality data, focused on the developed world, and showed a general decrease in heat sensitivity. Factors such as the implementation of a heat warning system, increased awareness, and improved quality of life were cited as contributing factors that led to the decreased impact of heat. Despite the overall recent decreases in heat vulnerability, spatial variability was shown, and differences with respect to health outcomes were also discussed. Several papers noted increases in heat\u27s impact on human health, particularly when unprecedented conditions occurred. Further, many populations, from outdoor workers to rural residents, in addition to the populations in much of the developing world, have been significantly underrepresented in research to date, and temporal changes in their vulnerability should be assessed in future studies. Moreover, continued monitoring and improvement of heat intervention is needed; with projected changes in the frequency, duration, and intensity of heat events combined with shifts in demographics, heat will remain a major public health issue moving forward

    The Mortality Response to Absolute and Relative Temperature Extremes

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    While the impact of absolute extreme temperatures on human health has been amply studied, far less attention has been given to relative temperature extremes, that is, events that are highly unusual for the time of year but not necessarily extreme relative to a location\u27s overall climate. In this research, we use a recently defined extreme temperature event metric to define absolute extreme heat events (EHE) and extreme cold events (ECE) using absolute thresholds, and relative extreme heat events (REHE) and relative extreme cold events (RECE) using relative thresholds. All-cause mortality outcomes using a distributed lag nonlinear model are evaluated for the largest 51 metropolitan areas in the US for the period 1975-2010. Both the immediate impacts and the cumulative 20-day impacts are assessed for each of the extreme temperature event types. The 51 metropolitan areas were then grouped into 8 regions for meta-analysis. For heat events, the greatest mortality increases occur with a 0-day lag, with the subsequent days showing below-expected mortality (harvesting) that decreases the overall cumulative impact. For EHE, increases in mortality are still statistically significant when examined over 20 days. For REHE, it appears as though the day-0 increase in mortality is short-term displacement. For cold events, both relative and absolute, there is little mortality increase on day 0, but the impacts increase on subsequent days. Cumulative impacts are statistically significant at more than half of the stations for both ECE and RECE. The response to absolute ECE is strongest, but is also significant when using RECE across several southern locations, suggesting that there may be a lack of acclimatization, increasing mortality in relative cold events both early and late in winter

    Recent Trends in Heat-Related Mortality in the United States: An Update Through 2018

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    Much research has shown a general decrease in the negative health response to extreme heat events in recent decades. With a society that is growing older, and a climate that is warming, whether this trend can continue is an open question. Using eight additional years of mortality data, we extend our previous research to explore trends in heat-related mortality across the United States. For the period 1975–2018, we examined the mortality associated with extreme-heat-event days across the 107 largest metropolitan areas. Mortality response was assessed over a cumulative 10-day lag period following events that were defined using thresholds of the excess heat factor, using a distributed-lag nonlinear model. We analyzed total mortality and subsets of age and sex. Our results show that in the past decade there is heterogeneity in the trends of heat-related human mortality. The decrease in heat vulnerability continues among those 65 and older across most of the country, which may be associated with improved messaging and increased awareness. These decreases are offset in many locations by an increase in mortality among men 45–64 (+1.3 deaths per year), particularly across parts of the southern and southwestern United States. As heat-warning messaging broadly identifies the elderly as the most vulnerable group, the results here suggest that differences in risk perception may play a role. Further, an increase in the number of heat events over the past decade across the United States may have contributed to the end of a decades-long downward trend in the estimated number of heat-related fatalities

    Polysaccharide utilization loci and nutritional specialization in a dominant group of butyrate-producing human colonic Firmicutes

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    Acknowledgements The Rowett Institute of Nutrition and Health (University of Aberdeen) receives financial support from the Scottish Government Rural and Environmental Sciences and Analytical Services (RESAS). POS is a PhD student supported by the Scottish Government (RESAS) and the Science Foundation Ireland, through a centre award to the APC Microbiome Institute, Cork, Ireland. Data Summary The high-quality draft genomes generated in this work were deposited at the European Nucleotide Archive under the following accession numbers: 1. Eubacterium rectale T1-815; CVRQ01000001–CVRQ0100 0090: http://www.ebi.ac.uk/ena/data/view/PRJEB9320 2. Roseburia faecis M72/1; CVRR01000001–CVRR010001 01: http://www.ebi.ac.uk/ena/data/view/PRJEB9321 3. Roseburia inulinivorans L1-83; CVRS01000001–CVRS0 100 0151: http://www.ebi.ac.uk/ena/data/view/PRJEB9322Peer reviewedPublisher PD

    Association of weekly suicide rates with temperature anomalies in two different climate types

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    Annual suicide deaths outnumber the total deaths from homicide and war combined. Suicide is a complex behavioral endpoint, and a simple cause-and-effect model seems highly unlikely, but relationships with weather could yield important insight into the biopsychosocial mechanisms involved in suicide deaths. This study has been designed to test for a relationship between air temperature and suicide frequency that is consistent enough to offer some predictive abilities. Weekly suicide death totals and anomalies from Toronto, Ontario, Canada (1986-2009) and Jackson, Mississippi, USA (1980-2006) are analyzed for relationships by using temperature anomaly data and a distributed lag nonlinear model. For both analysis methods, anomalously cool weeks show low probabilities of experiencing high-end suicide totals while warmer weeks are more likely to experience high-end suicide totals. This result is consistent for Toronto and Jackson. Weekly suicide totals demonstrate a sufficient association with temperature anomalies to allow some prediction of weeks with or without increased suicide frequency. While this finding alone is unlikely to have immediate clinical implications, these results are an important step toward clarifying the biopsychosocial mechanisms of suicidal behavior through a more nuanced understanding of the relationship between temperature and suicide

    Heterologous gene expression in the human gut bacteria Eubacterium rectale and Roseburia inulinivorans by means of conjugative plasmids

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    Acknowledgements The Rowett Institute (University of Aberdeen) receives financial support from the Scottish Government Rural and Environmental Sciences and Analytical Services (RESAS). POS was a PhD student supported by the Scottish Government (RESAS) and the Science Foundation Ireland, through a centre award (12/RC/2273) to APC Microbiome Ireland, Cork, Ireland.Peer reviewedPostprin

    Warm season cloud-to-ground lightning–precipitation relationships

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    ABSTRACT This study examines the relationship between cloud-to-ground (CG) lightning and surface precipitation using observations from six regions (each on the order of 10 000 km 2 ), April through October (1989-93), in the southcentral United States. The relationship is evaluated using two different methods. First, regression equations are fit to the data, initially for only the CG lightning flash density and precipitation, and then with additional atmospheric and lightning parameters. Second, days are categorized according to differences in the precipitationto-CG lightning ratio; the same additional parameters are then examined for differences occurring within each category. Results show that the relationship between CG lightning and surface precipitation is highly variable; r 2 coefficients range from 0.121 in Baton Rouge to 0.601 in Dallas. A measure of the positive CG lightning flash density is the best addition to the model, statistically significant in all regions. When days are categorized, the percentage of lightning that is positive shows the most significant differences between categories, ranging from Ͻ4% on days with a ''low'' precipitation-to-CG lightning ratio, to 12%-36% on days with a ''high'' ratio. Other lightning parameters give less significant results; however, three atmospheric parameters (CAPE, lifted index, and Showalter index) do show a significant trend suggesting that there is much less instability in the atmosphere on ''high'' ratio days than on ''low'' ratio days

    Water clarity patterns in South Florida coastal waters and their linkages to synoptic-scale wind forcing

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    Temporal variability in water clarity for South Florida’s marine ecosystems was examined through satellite-derived light attenuation (Kd) coefficients, in the context of wind- and weather patterns. Reduced water clarity along Florida’s coasts is often the result of abrupt wind-resuspension events and other exogenous factors linked to frontal passage, storms, and precipitation. Kd data between 1998 and 2013 were synthesized to form a normalized Kd index (KDI) and subsequently compared with Self Organizing Map (SOM)-based wind field categorizations to reveal spatiotemporal patterns and their inter-relationships. Kd climatological maximums occur from October through December along southern sections of the West Florida Shelf (WFS) and from January through March along the Florida Straits. Spatial clusters of elevated Kd occur along 3 spatial domains: central WFS, southern WFS, and Florida Straits near the Florida Reef Tract, where intra-seasonal variability is the highest, and clarity patterns are associated with transitional wind patterns sequenced with cyclonic circulation. Temporal wind transitions from southerly to northerly, typically accompanying frontal passages, most often result in elevated Kd response. Results demonstrate the potential of using synoptic climatological analysis and satellite indices for tracking variability in water clarity and other indicators related to biological health

    En[dj]uring [ʧ]unes or ma[tj]ure [ʤ]ukes? Yod-coalescence and yod-dropping in the Eighteenth-Century English Phonology database

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    Yod-coalescence involving alveolar consonants before LateModern English /uː/ from earlier /iu > juː/ is still variable and diffusing in Present-day English. For example, the Oxford English Dictionary (OED) gives both (/tj dj/) and (/ʧ ʤ/) British English pronunciations for tune (/tjuːn/, /tʃuːn/), mature (/mǝˈtjʊǝ/, /mǝˈʧʊǝ/), duke (/djuːk/, /dʒuːk/) and endure (/ᵻnˈdjʊə/, /εnˈdjʊə/, /ᵻnˈdʒʊə/, /εnˈdʒʊə/, /ᵻnˈdjɔː/, /εnˈdjɔː/, /ᵻnˈdʒɔː/, /εnˈdʒɔː/). Extensive variability in yod-coalescence and yod-dropping is not recent in origin, and we can already detect relevant patterns in the eighteenth century from the evidence of a range of pronouncing dictionaries. Beal (1996, 1999) notes a tendency for northern English and Scottish authors to be more conservative with regard to yod-coalescence. She concludes that we require ‘a comprehensive survey of the many pronouncing dictionaries and other works on pronunciation’ (1996: 379) to gain more insight into the historical variation patterns underlying Present-day English. This article presents some results from such a ‘comprehensive survey’: the Eighteenth- Century English Phonology Database (ECEP). Transcriptions of all relevant words located are compared across a range of eighteenth-century sources in order to determine the chronology of yod-coalescence and yod-dropping as well as internal (e.g. stress, phoneme type, presence of a following /r/) and external (e.g. prescriptive, geographical, social) motivations for these developments
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