120 research outputs found

    Impacts of climate change, land-use change and phosphorus reduction on phytoplankton in the River Thames (UK)

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    Potential increases of phytoplankton concentrations in river systems due to global warming and changing climate could pose a serious threat to the anthropogenic use of surface waters. Nevertheless, the extent of the effect of climatic alterations on phytoplankton concentrations in river systems has not yet been analysed in detail. In this study, we assess the impact of a change in precipitation and temperature on river phytoplankton concentration by means of a physically-based model. A scenario-neutral methodology has been employed to evaluate the effects of climate alterations on flow, phosphorus concentration and phytoplankton concentration of the River Thames (southern England). In particular, five groups of phytoplankton are considered, representing a range of size classes and pigment phenotypes, under three different land-use/land-management scenarios to assess their impact on phytoplankton population levels. The model results are evaluated within the framework of future climate projections, using the UK Climate Projections 09 (UKCP09) for the 2030s. The results of the model demonstrate that an increase in average phytoplankton concentration due to climate change is highly likely to occur, with the magnitude varying depending on the location along the River Thames. Cyanobacteria show significant increases under future climate change and land use change. An expansion of intensive agriculture accentuates the growth in phytoplankton, especially in the upper reaches of the River Thames. However, an optimal phosphorus removal mitigation strategy, which combines reduction of fertiliser application and phosphorus removal from wastewater, can help to reduce this increas

    Les activités des médecins du travail dans la prévention des TMS : ressources et contraintes

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    MSD represents the primary cause of occupational illness and the occupational health physician would appear to be a determining stakeholder in prevention. The studies of risk factors of MSD are important but the studies of intervention are limited. The objective of our research is double: understand the practices of occupational health physician and give the means of activity development. Theoretical framework is multidisciplinary approach about activity analysis. The problematic is to produce knowledge of activity of occupational health physicians to take into account their activity in the debate of professional evolution and pluridisciplinarity in health of work. The disciplinary skills of each equip of research produce some methods. Fifty physicians participate in our research. We have observed during 60 day with ergonomics methods, notably 200 sequences of medical consultation with protocol to record data, confirmed by institutions of protection of physician profession and protection of data. Some types of interview are realized (65): semi-directive, clarification, simple self-confrontation, cross self-confrontation. Furthermore, our research is based on the objective to develop the activity of occupational health physicians. To do this, we set up four groups of volunteer occupational health physicians. The discussion of groups is based on objective data of activity (14 discussion sessions) and on instruction of double (15 discussions sessions). All equips of our research have building a common reference to facilitate the data exploitation. Each equip has written one or some articles (in annex of report) to keep this specificity of data production based of disciplinary approach. The first result is that there are some skills of occupational health physicians to make prevention. Someone physicians prefer to realize their action in consultation while the others prefer make intervention in company. The professionals styles of physicians according to the gender building with experience and training depend on context of company, legislative prevention system, relationship between stakeholders and operators, which facilitate or slow down to built the room of maneuver to exercise these professional styles. The activity of physician can be to hamper in certain conditions. The occupational health physicians are the only one to follow the operators, the story of company and relationships of stakeholders, the evolution of health and work. They use their knowledge about work in company to help operator to understand the relation between work and health. They mobilize the words using by operators in consultation, with respected the medical secret, to modify the stakeholders representation of the interaction between work and health. In the other words, it is impossible to separate the individual approach and collective approach in prevention activity of occupational health physician. These different approaches organize the actions of physician. The discussion of research led to questioning the legislative evolution and comparing our French system with de others system like Quebec system.Les TMS constituent l'une des premières maladies professionnelles et les médecins du travail jouent un rôle important dans la prévention. Aujourd'hui les connaissances sur les facteurs de risque à l'origine de cette pathologie font l'objet de débats sur la prévention des TMS. Les recherches ont besoin d'évoluer vers une meilleure connaissance des modalités de prise en charge de ce risque par les professionnels de la prévention. L'objectif de notre recherche est donc double : comprendre les pratiques des médecins du travail et participer au développement de leur activité de prévention. Notre cadre théorique multidisciplinaire (ergonomie, clinique du travail, sociologie du travail) est celui de l'analyse du travail. Notre problématique est la production de connaissances sur l'activité réelle du médecin afin de contribuer au débat sur les évolutions de leur métier et la pluridisciplinarité en santé au travail. Plusieurs méthodologies ont été mises en œuvre selon les compétences et les disciplines de chaque équipe de recherche. Une cinquantaine de médecins volontaires ont participé à notre recherche. Nous avons fait plus de 60 jours d'observation ergonomique du travail sur le terrain, dont 200 observations de consultation avec un protocole validé par le conseil de l'ordre et la CNIL. Différentes formes d'entretiens (au total 65) ont été réalisés (semi-directif, d'explicitation, d'auto-confrontation simple et croisé). Afin de contribuer au développement de l'activité de prévention des médecins du travail, nous avons constitué quatre groupes de pairs qui ont pu échanger sur les traces de leur activité réelle (au total, 14 réunions collectives) et à partir des méthodologies d'instruction du sosie (au total, 15 réunions collectives). Nos équipes de recherche ont partagé un référentiel commun afin de faciliter l'exploitation des données. Pour ne pas perdre la spécificité de chaque discipline, chaque équipe a écrit un ou plusieurs textes (en annexes du rapport) qui constituent la base d'un document de synthèse. Premier résultat, il existe plusieurs manières et façons de faire de la prévention des TMS chez les médecins du travail. Certains médecins privilégient une action en consultation alors que d'autres sont plus dans une action en entreprise. Mais ces styles, s'ils correspondent à des postures professionnelles construites avec l'expérience et le parcours de formation, sont très dépendants du contexte de l'entreprise, des dispositifs légales de prévention et du type de relations avec les salariés, les acteurs de l'entreprise et de la prévention, qui rendent plus ou moins possibles leurs mises en œuvre. L'activité du médecin dans certaines conditions est empêchée. Les médecins du travail sont les seuls intervenants de la prévention à tenir dans la continuité l'histoire de l'entreprise, des relations, de la santé. Ils ramènent leurs connaissances sur le travail pour aider le salarié à faire les liens entre le travail et la santé. Ils mobilisent la parole des salariés issue de la consultation dans les espaces d'échanges publics de l'entreprise, tout en respectant le secret médical, afin de modifier la représentation des acteurs sur les liens travail-santé. Autrement dit, il est impossible dans l'activité de prévention du médecin de délier l'approche individuelle et collective car celles-ci sont sans arrêt articuler et combiner. Cela conduit à s'interroger sur l'évolution de la loi et à comparer les pratiques avec d'autres systèmes de prévention, comme celui du Québec

    Impacts of climate change, land-use change and phosphorus reduction on phytoplankton in the River Thames (UK)

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    Potential increases of phytoplankton concentrations in river systems due to global warming and changing climate could pose a serious threat to the anthropogenic use of surface waters. Nevertheless, the extent of the effect of climatic alterations on phytoplankton concentrations in river systems has not yet been analysed in detail. In this study, we assess the impact of a change in precipitation and temperature on river phytoplankton concentration by means of a physically-based model. A scenario-neutral methodology has been employed to evaluate the effects of climate alterations on flow, phosphorus concentration and phytoplankton concentration of the River Thames (southern England). In particular, five groups of phytoplankton are considered, representing a range of size classes and pigment phenotypes, under three different land-use/land-management scenarios to assess their impact on phytoplankton population levels. The model results are evaluated within the framework of future climate projections, using the UK Climate Projections 09 (UKCP09) for the 2030s. The results of the model demonstrate that an increase in average phytoplankton concentration due to climate change is highly likely to occur, with the magnitude varying depending on the location along the River Thames. Cyanobacteria show significant increases under future climate change and land use change. An expansion of intensive agriculture accentuates the growth in phytoplankton, especially in the upper reaches of the River Thames. However, an optimal phosphorus removal mitigation strategy, which combines reduction of fertiliser application and phosphorus removal from wastewater, can help to reduce this increase in phytoplankton concentration, and in some cases, compensate for the effect of rising temperature

    Detection of Anopheles stephensi mosquitoes by molecular surveillance, Kenya

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    The Anopheles stephensi mosquito is an invasive malaria vector recently reported in Djibouti, Ethiopia, Sudan, Somalia, Nigeria, and Ghana. The World Health Organization has called on countries in Africa to increase surveillance efforts to detect and report this vector and institute appropriate and effective control mechanisms. In Kenya, the Division of National Malaria Program conducted entomological surveillance in counties at risk for An. stephensi mosquito invasion. In addition, the Kenya Medical Research Institute conducted molecular surveillance of all sampled Anopheles mosquitoes from other studies to identify An. stephensi mosquitoes. We report the detection and confirmation of An. stephensi mosquitoes in Marsabit and Turkana Counties by using endpoint PCR and morphological and sequence identification. We demonstrate the urgent need for intensified entomological surveillance in all areas at risk for An. stephensi mosquito invasion, to clarify its occurrence and distribution and develop tailored approaches to prevent further spread

    Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

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    Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Significant variation in transformation frequency in Streptococcus pneumoniae

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    The naturally transformable bacterium Streptococcus pneumoniae is able to take up extracellular DNA and incorporate it into its genome. Maintaining natural transformation within a species requires that the benefits of transformation outweigh its costs. Although much is known about the distribution of natural transformation among bacterial species, little is known about the degree to which transformation frequencies vary within species. Here we find that there is significant variation in transformation frequency between strains of Streptococcus pneumoniae isolated from asymptomatic carriage, and that this variation is not concordant with isolate genetic relatedness. Polymorphism in the signalling system regulating competence is also not causally related to differences in transformation frequency, although this polymorphism does influence the degree of genetic admixture experienced by bacterial strains. These data suggest that bacteria can evolve new transformation frequencies over short evolutionary timescales. This facility may permit cells to balance the potential costs and benefits of transformation by regulating transformation frequency in response to environmental conditions

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
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