313 research outputs found

    Modeling the influence of environmental factors on human respiratory irritation from natural exposures to Karenia brevis aerosols

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    Presented at CERF 2015: Grand Challenges in Coastal & Estuarine Science, Portland, Oregon, November 8 - 12, 2015 and at the Eighth Symposium on Harmful Algae in the U.S., Long Beach, California, November 15 – 19, 2015.The Coupled Natural and Human Systems program of US National Science Foundation is supporting our effort to elucidate linkages between harmful algal blooms and associated impacts on human health, society and economy of coastal communities. The human respiratory system is negatively impacted by inhaled toxic aerosols from the Florida red tide dinoflagellate, Karenia brevis. It has been hypothesized that surf height, wind speed, and wind direction were the predominant factors determining the amount of toxin reaching exposed individuals. Recent findings indicate that there are more environmental factors influencing the level of respiratory impacts from brevetoxins. We report on analyses that include additional factors such as air temperature, water temperature, dew point, barometric pressure, K. brevis cell counts, annd distance and direction from K. brevis cells to the individual. Factors contributing most to differences between no respiratory irritation and mild respiratory irritation were water temperature, air temperature, and dew point. Those factors contributing most to differences between mild respiratory irritation and moderate respiratory irritation were wind direction, surf conditions, and wind speed. Data on respiratory impacts was provided by the Beach Conditions Reporting System (BCRS). This system provides twice daily reports from lifeguards and park rangers at public beaches. These subjective reports include observed levels of respiratory irritation among beach-goers. Other environmental data were provided by a variety of local sources including private and public weather stations and many monitoring and research efforts. The resultant model provides a means to forecast respiratory impacts from observations of HAB distribution, and meteorological and oceanographic conditions.ECOHAB FL – NA06NOS478024; NSF Coupled Human and Natural Systems - # 1009106; Research Experience for Undergraduates - # 0453955; FWCC – FL Red Tide Cooperative Agreement

    Spin glasses without time-reversal symmetry and the absence of a genuine structural glass transition

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    We study the three-spin model and the Ising spin glass in a field using Migdal-Kadanoff approximation. The flows of the couplings and fields indicate no phase transition, but they show even for the three-spin model a slow crossover to the asymptotic high-temperature behaviour for strong values of the couplings. We also evaluated a quantity that is a measure of the degree of non-self-averaging, and we found that it can become large for certain ranges of the parameters and the system sizes. For the spin glass in a field the maximum of non-self-averaging follows for given system size a line that resembles the de Almeida-Thouless line. We conclude that non-self-averaging found in Monte-Carlo simulations cannot be taken as evidence for the existence of a low-temperature phase with replica-symmetry breaking. Models similar to the three-spin model have been extensively discussed in order to provide a description of structural glasses. Their theory at mean-field level resembles the mode-coupling theory of real glasses. At that level the one-step replica symmetry approach breaking predicts two transitions, the first transition being dynamical and the second thermodynamical. Our results suggest that in real finite dimensional glasses there will be no genuine transitions at all, but that some features of mean-field theory could still provide some useful insights.Comment: 11 pages, 11 figure

    Numerical study of a short-range p-spin glass model in three dimensions

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    In this work we study numerically a short range p-spin glass model in three dimensions. The behaviour of the model appears to be remarkably different from mean field predictions. In fact it shares some features typical of models with full replica-symmetry breaking (FRSB). Nevertheless, we believe that the transition that we study is intrinsically different from the FRSB and basically due to non-perturbative contributions. We study both the statics and the dynamics of the system which seem to confirm our conjectures.Comment: 20 pages, 15 figure

    First record of verticillium wilt (Verticillium longisporum) in winter oilseed rape in the UK

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    Verticillium longisporum is an important pathogen of oilseed rape (OSR) and vegetable brassicas in several European countries, but has not been reported previously in the UK (Karapapa et al., 1997; Steventon et al., 2002). In 2007, Verticillium wilt was suspected in UK crops of winter OSR (W-OSR) on cv. Castille in Romney Marsh, Kent and on cv. Barrel near Hereford. At these two locations, 32 and 10% of the plants, respectively, appeared to be affected, but the presence of stem canker may have masked some infections. Symptoms were first seen as the crops began to ripen (seeds green-brown to brown, Growth Stage: 6,4-6,5) and included brown and dark grey vertical bands on the stems from soil level into the branches, and premature ripening of some branches (Fig. 1). Microsclerotia were observed on stem samples collected in the field (Fig. 2), suggesting V. longisporum as the causal agent. Cultures were prepared from field samples by immersing stem pieces in 5% sodium hypochlorite solution for one minute, washing twice in sterile distilled water and plating onto potato dextrose agar containing 25 mg/l streptomycin sulphate. Isolates from three plants per outbreak were identified morphologically as V. longisporum. Mean conidial dimensions (25 spores per isolate) were 8.80-9.65 μm (length) and 2.50-2.85 μm (width) and all isolates produced elongated microsclerotia, characters typical of V. longisporum (Karapapa et al., 1997). The identity was confirmed by PCR using species-specific primers (Steventon et al., 2002) and, as a member of the α sub-group, by direct sequencing of the amplicons from primer pairs ITS4-ITS5 and DB19-DB22 (Collins et al., 2003; 2005). Sequences for isolate 003 from Kent were deposited in GenBank (Accession Nos. HQ702376 and HQ702377). All isolates tested from 2008 and 2009 were identical with previously deposited sequences for European OSR isolates (e.g. AF363992 and AF363246 respectively). Pathogenicity was confirmed by inoculating three OSR cv. Castille seedlings per isolate using the root dip technique with 1 x 106 spores/ml (Karapapa et al., 1997) under heated glasshouse conditions at 19°C. Leaf yellowing and blackening of the leaf veins were found 26 days after inoculation (Fig. 3). Yellowing affecting the three oldest leaves increased for seven to nine days. After five weeks the final mean leaf area affected was 63-78% with no differences between isolates. No leaf yellowing occurred in the controls. After five weeks, V. longisporum was re-isolated from all the inoculated seedlings, but not from the non-inoculated controls. In June 2008, infection of W-OSR crops in different fields on the same farms was found on cv. Es Astrid in Kent (56% incidence) and on cv. Lioness in Hereford (15% incidence). The Kent farm had been growing W-OSR alternating with winter wheat for at least 10 years whilst the Hereford farm had grown W-OSR one year in four. These short rotations of OSR may be contributing to the appearance of this disease. This study confirms the identification of V. longisporum on any host in the UK, through molecular studies and detailed spore measurements that were not reported in an earlier review (Gladders, 2009). This pathogen occurs in several European countries and, since OSR may be traded freely, following a Defra consultation, no statutory plant health action is to be taken

    Exploring the Possibilities: Earth and Space Science Missions in the Context of Exploration

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    According to Dr. Edward J. Weiler, Director of the Goddard Space Flight Center, "Exploration without science is tourism". At the American Astronautical Society's 43rd Annual Robert H. Goddard Memorial Symposium it was quite apparent to all that NASA's current Exploration Initiative is tightly coupled to multiple scientific initiatives: exploration will enable new science and science will enable exploration. NASA's Science Mission Directorate plans to develop priority science missions that deliver science that is vital, compelling and urgent. This paper will discuss the theme of the Goddard Memorial Symposium that science plays a key role in exploration. It will summarize the key scientific questions and some of the space and Earth science missions proposed to answer them, including the Mars and Lunar Exploration Programs, the Beyond Einstein and Navigator Programs, and the Earth-Sun System missions. It will also discuss some of the key technologies that will enable these missions, including the latest in instruments and sensors, large space optical system technologies and optical communications, and briefly discuss developments and achievements since the Symposium. Throughout history, humans have made the biggest scientific discoveries by visiting unknown territories; by going to the Moon and other planets and by seeking out habitable words, NASA is continuing humanity's quest for scientific knowledge

    The human health effects of Florida Red Tide (FRT) blooms : an expanded analysis

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    Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Environment International 68 (2014): 144-153, doi:10.1016/j.envint.2014.03.016.Human respiratory and digestive illnesses can be caused by exposures to brevetoxins from blooms of the marine alga Karenia brevis, also known as Florida red tide (FRT). K. brevis requires macro-nutrients to grow; although the sources of these nutrients have not been resolved completely, they are thought to originate both naturally and anthropogenically. The latter sources comprise atmospheric depositions, industrial effluents, land runoffs, or submerged groundwater discharges. To date, there has been only limited research on the extent of human health risks and economic impacts due to FRT. We hypothesized that FRT blooms were associated with increases in the numbers of emergency room visits and hospital inpatient admissions for both respiratory and digestive illnesses. We sought to estimate these relationships and to calculate the costs of associated adverse health impacts. We developed environmental exposure-response models to test the effects of FRT blooms on human health, using data from diverse sources. We estimated the FRT bloom-associated illness costs, using extant data and parameters from the literature. When controlling for resident population, a proxy for tourism, and seasonal and annual effects, we found that increases in respiratory and digestive illnesses can be explained by FRT blooms. Specifically, FRT blooms were associated with human health and economic effects in older cohorts (≥ 55 years of age) in six southwest Florida counties. Annual costs of illness ranged from 60,000to60,000 to 700,000 annually, but these costs could exceed 1.0millionperyearforsevere,longlastingFRTblooms,suchastheonethatoccurredduring2005.AssumingthattheaverageannualillnesscostsofFRTbloomspersistintothefuture,usingadiscountrateof31.0 million per year for severe, long-lasting FRT blooms, such as the one that occurred during 2005. Assuming that the average annual illness costs of FRT blooms persist into the future, using a discount rate of 3%, the capitalized costs of future illnesses would range between 2-24 million.This research was sponsored by the National Science Foundation under NSF/CNH Grant No. 1009106.L.E. Fleming acknowledges support from the European Regional Development Fund and the European Social Fund Convergence Programme for Cornwall and the Isles of Scilly

    Changes in work habits of lifeguards in relation to Florida red tide

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    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Harmful Algae 9 (2010): 419-425, doi:10.1016/j.hal.2010.02.005.The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead to respiratory illness in humans. Although several studies have assessed different economic impacts from Florida red tide blooms, no studies to date have considered the impact on beach lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs lifeguards at its beaches 365 days a year. This study examined lifeguard attendance records during the time periods of March 1 to September 30 in 2004 (no bloom) and March 1 to September 30 in 2005 (bloom). The lifeguard attendance data demonstrated statistically significant absenteeism during a Florida red tide bloom. The potential economic costs resulting from red tide blooms were comprised of both lifeguard absenteeism and presenteeism. Our estimate of the costs of absenteeism due to the 2005 red tide in Sarasota County is about 3,000.Onaverage,thecapitalizedcostsoflifeguardabsenteeisminSarasotaCountymaybeontheorderof3,000. On average, the capitalized costs of lifeguard absenteeism in Sarasota County may be on the order of 100,000 at Sarasota County beaches alone. When surveyed, lifeguards reported not only that they experienced adverse health effects of exposure to Florida red tide but also that their attentiveness and abilities to take preventative actions decrease when they worked during a bloom, implying presenteeism effects. The costs of presenteeism, which imply increased risks to beachgoers, arguably could exceed those of absenteeism by an order of magnitude. Due to the lack of data, however, we are unable to provide credible estimates of the costs of presenteeism or the potential increased risks to bathers.This research was supported by the National Science Foundation under The Research Experience for Undergraduate Program, grant number 0453955; the P01 ES 10594, DHHS NIH of the National Institute of Environmental Health Sciences; the Center for Oceans and Human Health at the Woods Hole Oceanographic Institution [National Science Foundation (NSF) OCE-0430724; National Institute of Environmental Health Sciences (NIEHS) P50 ES012742]; and the Ocean and Human Health Center at the University of Miami Rosenstiel School (NSF 0CE0432368; NIEHS 1 P50 ES12736)

    Human responses to Florida red tides : policy awareness and adherence to local fertilizer ordinances

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    Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Science of The Total Environment 493 (2014): 898-909, doi:10.1016/j.scitotenv.2014.06.083.To mitigate the damages of natural hazards, policy responses can be beneficial only if they are effective. Using a self-administered survey approach, this paper focuses on the adherence to local fertilizer ordinances (i.e., county or municipal rules regulating the application of fertilizer to private lawns or facilities such as golf courses) implemented in jurisdictions along the southwest Florida coast in response to hazardous blooms of Florida red tides (Karenia brevis). These ordinances play a role in the context of evolving programs of water pollution control at federal, state, water basin, and local levels. With respect to policy effectiveness, while the strength of physical linkages is of critical importance, the extent to which humans affected are aware of and adhere to the relevant rules, is equally critical. We sought to understand the public’s depth of understanding about the rationales for local fertilizer ordinances. Respondents in Sarasota, Florida, were asked about their fertilizer practices in an area that has experienced several major blooms of Florida red tides over the past two decades. A highly educated, older population of 305 residents and “snowbirds” reported relatively little knowledge about a local fertilizer ordinance, its purpose, or whether it would change the frequency, size, or duration of red tides. This finding held true even among subpopulations that were expected to have more interest in or to be more knowledgeable about harmful algal blooms. In the face of uncertain science and environmental outcomes, and with individual motivations at odds with evolving public policies, the effectiveness of local community efforts to decrease the impacts of red tides may be compromised. Targeted social-science research on human perceptions about the risks of Florida red tides and education about the rationales for potential policy responses is warranted.This work was funded under sponsorship of the National Science Foundation (NSF), awards #1009106 and #1004181and the National Institute for Environmental Health Sciences (NIEHS), award # R21ES017413-01A2. Fleming received support from the European Regional Development Fund and European Social Fund (European Centre for Environment and Human Health, University of Exeter Medical School)

    Characterization of Aerosols Containing Microcystin

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    Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 μm. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ

    The Key Attributes of a Successful Relationship with Service Users in Family Support: Views of Family Support Workers

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    Existing research on family support suggests that key to the family’s engagement and satisfaction is the family’s perception of the quality of the relationship established with their assigned support worker (McArthur & Thompson, 2011; Mason, 2012). The research reported here explores the views of the other partner in this relationship, the family support worker. Two experienced family support workers were interviewed about their views of what where the key attributes of a successful relationship with the families they worked with. The data was thematically analysed and three themes identified. There were overcoming barriers; skills needed to build a successful working relationship; approaches to working that were considered to be successful. These findings concur with those researching the family’s viewpoint suggesting compatibility in beliefs about successful working relationships between the two parties involved
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