563 research outputs found

    Milieurisicogrenzen voor ethylbenzeen and tributylfosfaat in water : Een voorstel voor waterkwaliteitsnormen volgens de Kaderrichtlijn Water

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    Het RIVM heeft in opdracht van het ministerie van Infrastructuur en Milieu (I&M) milieurisicogrenzen voor ethylbenzeen en tributylfosfaat in water bepaald. De stoffen zijn opgenomen in de Regeling monitoring Kaderrichtlijn Water, waarin staat aan welke eisen oppervlaktewater in Nederland moet voldoen. Voor deze stoffen moeten nieuwe waterkwaliteitsnormen worden vastgesteld, omdat de huidige normen niet zijn afgeleid volgens de meest recente methodiek. Op basis van meetgegevens over 2010 is er geen aanwijzing dat de voorgestelde waterkwaliteitsnormen worden overschreden. Normvoorstellen: De normvoorstellen voor ethylbenzeen zijn gebaseerd op de Europese risicobeoordeling voor deze stof. De KRW kent voor zoet en zout oppervlaktewater twee typen normen, de Jaargemiddelde Milieukwaliteitsnorm (JG-MKN) en de Maximaal Aanvaardbare Concentratie (MAC-MKN). De JG-MKN is de concentratie in water waarbij geen schadelijke effecten te verwachten zijn, gebaseerd op jaargemiddelde concentraties. Hiervoor zijn drie routes onderzocht: directe effecten op waterorganismen, indirecte effecten op vogels en zoogdieren via het eten van prooidieren en indirecte effecten op mensen via het eten van voedsel. De laagste van deze drie bepaalt de voorgestelde JG-MKN; voor ethylbenzeen is dat 65 microgram per liter voor zoetwater en 10 microgram per liter voor zoutwater. De Maximaal Aanvaardbare Concentratie (MAC-MKN) is de concentratie die het ecosysteem beschermt tegen kortdurende effecten. De voorgestelde MAC-MKN is 220 en 22 microgram per liter voor respectievelijk zoet- en zoutwater. Voor tributylfosfaat zijn al eerder voorstellen gedaan om de JG-MKN te herzien (66 en 6,6 microgram per liter voor zoet- en zoutwater). In aanvulling daarop wordt nu een MAC-MKN voorgesteld van 170 microgram per liter voor zoetwater en 17 microgram per liter voor zoutwater.RIVM has derived environmental risk limits (ERLs) for ethylbenzene and tributylphosphate in water. Both compounds are included in the Dutch decree on water quality objectives in the context of the Water Framework Directive (WFD). The standards have to be updated according to the current WFD-methodology. The values in this report serve as a scientific background for the Dutch Steering Committee for Substances, which is responsible for setting those standards. Monitoring data from 2010 indicate that the proposed standards will not be exceeded. Proposed standards: The proposal for ethylbenzene is based on the European risk assessment report (EU-RAR) for this compound. According to the WFD, two different standards are proposed for fresh- and saltwater. The Maximum Permissible Concentration (MPC) is the level at which no harmful effects are expected, based on annual average concentrations. This MPC is derived for three routes: direct ecotoxicity, secondary poisoning, and consumption of fish by humans. The lowest of these values determines the final MPC (65 microgram per litre for freshwater and 10 microgram per litre for saltwater). The Maximum Acceptable Concentration (MACeco) is the concentration which protects ecosystems from effects of short term concentration peaks. MAC-values of 220 and 22 microgram per litre are proposed for freshwater and saltwater, respectively. For tributylphosphate, updated MPC-values have been derived previously (66 and 6.6 microgram per litre for fresh- and saltwater). In addition, MAC-values of 170 and 17 microgram per litre are proposed for the respective water types.Ministerie van Infrastructuur en Milie

    Waterkwaliteitsnormen voor PFOA : Een voorstel volgens de methodiek van de Kaderrichtlijn Water

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    RIVM proposes water quality standards for PFOA. This perfluoro compound has been used for the production of teflon and is found in many surface waters around the world. The quality standard for chronic exposure accounts for the accumulation of PFOA in fish. Using this information, RIVM calculated a safe concentration in water of 48 nanograms per liter, which is protective for lifetime consumption of fish by humans and wildlife. For this research an extensive overview was made of the scientific data on effects of PFOA on aquatic organisms and the accumulation in biota. Based on the oral risk limit for humans as derived recently by RIVM, a maximum allowable concentration in fish was calculated assuming a lifetime daily consumption. This biota standard is converted to an equivalent safe concentration in water using information on the uptake of PFOA from water by fish. Data on bioaccumulation are needed because the water quality standard for ecological effects on aquatic organisms is not sufficiently protective for food chain effects. PFOA has a relatively low toxicity for water organisms, but may pose a problem when entering the food chain via fish. The use of PFOA is restricted by European law, but it can still reach the environment from PFOA-containing products that were produced in the past. Because of its high persistence, emissions will lead to long term presence in the environment. An initial comparison with monitoring data indicates that the safe concentration derived in this research is not exceeded in Dutch surface waters.Het RIVM doet een voorstel voor waterkwaliteitsnormen voor PFOA. Deze perfluorverbinding is jarenlang gebruikt bij de productie van teflon en wordt overal ter wereld in het oppervlaktewater aangetroffen. De norm voor de langetermijn-blootstelling houdt rekening met de mate waarin PFOA zich ophoopt in vis. Met die informatie heeft het RIVM berekend dat een concentratie van 48 nanogram per liter veilig is als mensen, vogels en zoogdieren hun leven lang vis uit dat water zouden eten. Voor dit onderzoek is een uitgebreid overzicht gemaakt van wat er in de wetenschappelijke literatuur bekend is over de effecten van PFOA op waterorganismen en in welke mate ze deze stof opnemen. In eerder onderzoek heeft het RIVM bepaald hoeveel een mens van de stof zou mogen binnenkrijgen zonder daar schadelijke gevolgen van te ondervinden. Vervolgens is berekend wat er maximaal in vis zou mogen zitten als mensen elke dag gedurende hun hele leven vis zouden eten. Deze waarde in vis is vertaald naar een veilige concentratie in water. Dit is gedaan met behulp van gegevens over de mate waarin vissen PFOA opnemen vanuit het water. Deze werkwijze is gevolgd omdat de voedselketen onvoldoende wordt beschermd door de ecologische norm voor waterorganismen. PFOA is relatief weinig giftig voor waterorganismen zelf, maar kan een probleem vormen als de stof via vis in de voedselketen terechtkomt. Het gebruik van PFOA is in Europa inmiddels aan banden gelegd, maar kan nog wel vrijkomen uit producten waarin de stof in het verleden is verwerkt. Omdat PFOA nauwelijks afbreekt, zullen restanten nog lang in het milieu aanwezig blijven. Uit een eerste vergelijking met meetgegevens blijkt echter dat de veilige concentratie momenteel niet wordt overschreden in Nederlands oppervlaktewaterMinisterie van I&

    Density responses of lesser-studied carnivores to habitat and management strategies in southern Tanzania's Ruaha-Rungwa landscape.

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    Compared to emblematic large carnivores, most species of the order Carnivora receive little conservation attention despite increasing anthropogenic pressure and poor understanding of their status across much of their range. We employed systematic camera trapping and spatially explicit capture-recapture modelling to estimate variation in population density of serval, striped hyaena and aardwolf across the mixed-use Ruaha-Rungwa landscape in southern Tanzania. We selected three sites representative of different habitat types, management strategies, and levels of anthropogenic pressure: Ruaha National Park’s core tourist area, dominated by Acacia-Commiphora bushlands and thickets; the Park’s miombo woodland; and the neighbouring community-run MBOMIPA Wildlife Management Area, also covered in Acacia-Commiphora. The Park’s miombo woodlands supported a higher serval density (5.56 [Standard Error = ±2.45] individuals per 100 km2) than either the core tourist area (3.45 [±1.04] individuals per 100 km2) or the Wildlife Management Area (2.08 [±0.74] individuals per 100 km2). Taken together, precipitation, the abundance of apex predators, and the level of anthropogenic pressure likely drive such variation. Striped hyaena were detected only in the Wildlife Management Area and at low density (1.36 [±0.50] individuals per 100 km2), potentially due to the location of the surveyed sites at the edge of the species’ global range, high densities of sympatric competitors, and anthropogenic edge effects. Finally, aardwolf were captured in both the Park’s core tourist area and the Wildlife Management Area, with a higher density in the Wildlife Management Area (13.25 [±2.48] versus 9.19 [±1.66] individuals per 100 km2), possibly as a result of lower intraguild predation and late fire outbreaks in the area surveyed. By shedding light on three understudied African carnivore species, this study highlights the importance of miombo woodland conservation and community-managed conservation, as well as the value of by-catch camera trap data to improve ecological knowledge of lesser-studied carnivores

    Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands

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    "© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)

    Increased risk of pneumonia in residents living near poultry farms: does the upper respiratory tract microbiota play a role?

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    BACKGROUND: Air pollution has been shown to increase the susceptibility to community-acquired pneumonia (CAP). Previously, we observed an increased incidence of CAP in adults living within 1 km from poultry farms, potentially related to particulate matter and endotoxin emissions. We aim to confirm the increased risk of CAP near poultry farms by refined spatial analyses, and we hypothesize that the oropharyngeal microbiota composition in CAP patients may be associated with residential proximity to poultry farms. METHODS: A spatial kernel model was used to analyze the association between proximity to poultry farms and CAP diagnosis, obtained from electronic medical records of 92,548 GP patients. The oropharyngeal microbiota composition was determined in 126 hospitalized CAP patients using 16S-rRNA-based sequencing, and analyzed in relation to residential proximity to poultry farms. RESULTS: Kernel analysis confirmed a significantly increased risk of CAP when living near poultry farms, suggesting an excess risk up to 1.15 km, followed by a sharp decline. Overall, the oropharyngeal microbiota composition differed borderline significantly between patients living <1 km and ≥1 km from poultry farms (PERMANOVA p = 0.075). Results suggested a higher abundance of Streptococcus pneumoniae (mean relative abundance 34.9% vs. 22.5%, p = 0.058) in patients living near poultry farms, which was verified by unsupervised clustering analysis, showing overrepresentation of a S. pneumoniae cluster near poultry farms (p = 0.049). CONCLUSION: Living near poultry farms is associated with an 11% increased risk of CAP, possibly resulting from changes in the upper respiratory tract microbiota composition in susceptible individuals. The abundance of S. pneumoniae near farms needs to be replicated in larger, independent studies

    Protein disulfide isomerases as CSF biomarkers for the neuronal response to tau pathology

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    Introduction: Cerebrospinal fluid (CSF) biomarkers for specific cellular disease processes are lacking for tauopathies. In this translational study we aimed to identify CSF biomarkers reflecting early tau pathology-associated unfolded protein response (UPR) activation. Methods: We employed mass spectrometry proteomics and targeted immunoanalysis in a combination of biomarker discovery in primary mouse neurons in vitro and validation in patient CSF from two independent large multicentre cohorts (EMIF-AD MBD, n = 310; PRIDE, n = 771). Results: First, we identify members of the protein disulfide isomerase (PDI) family in the neuronal UPR-activated secretome and validate secretion upon tau aggregation in vitro. Next, we demonstrate that PDIA1 and PDIA3 levels correlate with total- and phosphorylated-tau levels in CSF. PDIA1 levels are increased in CSF from AD patients compared to controls and patients with tau-unrelated frontotemporal and Lewy body dementia (LBD). Highlights: Neuronal unfolded protein response (UPR) activation induces the secretion of protein disulfide isomerases (PDIs) in vitro. PDIA1 is secreted upon tau aggregation in neurons in vitro. PDIA1 and PDIA3 levels correlate with total and phosphorylated tau levels in CSF. PDIA1 levels are increased in CSF from Alzheimer's disease (AD) patients compared to controls. PDIA1 levels are not increased in CSF from tau-unrelated frontotemporal dementia (FTD) and Lewy body dementia (LBD) patients

    Endophenotypes in a Dynamically Connected Brain

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    We examined the longitudinal genetic architecture of three parameters of functional brain connectivity. One parameter described overall connectivity (synchronization likelihood, SL). The two others were derived from graph theory and described local (clustering coefficient, CC) and global (average path length, L) aspects of connectivity. We measured resting state EEG in 1,438 subjects from four age groups of about 16, 18, 25 and 50 years. Developmental curves for SL and L indicate that connectivity is more random at adolescence and old age, and more structured in middle-aged adulthood. Individual variation in SL and L were moderately to highly heritable at each age (SL: 40–82%; L: 29–63%). Genetic factors underlying these phenotypes overlapped. CC was also heritable (25–49%) but showed no systematic overlap with SL and L. SL, CC, and L in the alpha band showed high phenotypic and genetic stability from 16 to 25 years. Heritability for parameters in the beta band was lower, and less stable across ages, but genetic stability was high. We conclude that the connectivity parameters SL, CC, and L in the alpha band show the hallmarks of a good endophenotype for behavior and developmental disorders

    Positive and negative well-being and objectively measured sedentary behaviour in older adults: evidence from three cohorts

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    Background: Sedentary behaviour is related to poorer health independently of time spent in moderate to vigorous physical activity. The aim of this study was to investigate whether wellbeing or symptoms of anxiety or depression predict sedentary behaviour in older adults. Method: Participants were drawn from the Lothian Birth Cohort 1936 (LBC1936) (n = 271), and the West of Scotland Twenty-07 1950s (n = 309) and 1930s (n = 118) cohorts. Sedentary outcomes, sedentary time, and number of sit-to-stand transitions, were measured with a three-dimensional accelerometer (activPAL activity monitor) worn for 7 days. In the Twenty-07 cohorts, symptoms of anxiety and depression were assessed in 2008 and sedentary outcomes were assessed ~ 8 years later in 2015 and 2016. In the LBC1936 cohort, wellbeing and symptoms of anxiety and depression were assessed concurrently with sedentary behaviour in 2015 and 2016. We tested for an association between wellbeing, anxiety or depression and the sedentary outcomes using multivariate regression analysis. Results: We observed no association between wellbeing or symptoms of anxiety and the sedentary outcomes. Symptoms of depression were positively associated with sedentary time in the LBC1936 and Twenty-07 1950s cohort, and negatively associated with number of sit-to-stand transitions in the LBC1936. Meta-analytic estimates of the association between depressive symptoms and sedentary time or number of sit-to-stand transitions, adjusted for age, sex, BMI, long-standing illness, and education, were β = 0.11 (95% CI = 0.03, 0.18) and β = − 0.11 (95% CI = − 0.19, −0.03) respectively. Conclusion: Our findings indicate that depressive symptoms are positively associated with sedentary behavior. Future studies should investigate the causal direction of this association

    Infochemical-tritrophic Interactions of Soybean Aphids-host Plants-natural Enemies and Their Practical Applications in Pest Management

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    The soybean aphid, Aphis glycines Matsumura, is a newly invasive insect species that seriously threatens U.S. soybean production. This aphid pest has kept haunting many soybean growers by developing large colonies on soybeans in North America since 2000. Since its first appearance inWisconsin, it has spread to over half of US states and southern provinces in Canada. The heavy infestation of this pest whittles soybean growers’ profits and causes hundreds of million dollar losses. The present chapter will mainly describe efforts in studying aphid chemical ecology and sensory physiology for understanding how male aphids find their mates and host plants. It will also cover research efforts to understand host plant associated volatiles being used as cues for overwintering host plant location. In addition, findings on how soybean plant defensive system works against aphid infestation, as well as how those induced plant volatiles are used by aphid’s natural enemies for prey location will be presented. Finally, the use the basic understandings for developing useful tools for soybean aphid practical control will be discussed

    Design of an internet-based health economic evaluation of a preventive group-intervention for children of parents with mental illness or substance use disorders

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    Background Preventive interventions are developed for children of parents with mental and substance use disorders (COPMI), because these children have a higher risk of developing a psychological or behavioral disorder in the future. Mental health and substance use disorders contribute significantly to the global burden of disease. Although the exact number of parents with a mental illness is unclear, the subject of mentally ill parents is gaining attention. Moreover there is a lack of interventions for COPMI-children, as well of (cost-) effectiveness studies evaluating COPMI interventions. Innovative interventions such as e-health provide a new field for exploration. There is no knowledge about the opportunities for using the internet to prevent problems in children at risk. In the current study we will focus on the (cost-) effectiveness of an online health prevention program for COPMI-children. Methods/Design We designed a randomized controlled trial to examine the (cost-) effectiveness of the Kopstoring intervention. Kopstoring is an online intervention for COPMI-children to strengthen their coping skills and prevent behavioral and psychological problems. We will compare the Kopstoring intervention with (waiting list) care as usual. This trial will be conducted entirely over the internet. An economic evaluation, from a societal perspective will be conducted, to examine the trial's cost-effectiveness. Power calculations show that 214 participants are needed, aged 16-25. Possible participants will be recruited via media announcements and banners on the internet. After screening and completing informed consent procedures, participants will be randomized. The main outcome is internalizing and externalizing symptoms as measured by the Youth Self Report. For the economic evaluation, healthcare costs and costs outside the healthcare sector will be measured at the same time as the clinical measures, at baseline, 3, 6 and 9 months. An extended measure for the intervention group will be provided at 12 months, to examine the long-term effects. In addition, a process evaluation will be conducted. Discussion Recent developments, such as international conferences and policy discussions, show the pressing need to study the (cost-) effectiveness of interventions for vulnerable groups of children. This study will shed light on the (cost-) effectiveness of an online preventive intervention
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