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Risk assessment of pesticide impacts on remote ecosystems makes use of model-estimated degradation in air. Recent studies suggest these degradation rates to be overestimated, questioning current pesticide regulation. Here, we investigated the concentrations of 76 pesticides in Europe at 29 rural, coastal, mountain, and polar sites during the agricultural application season. Overall, 58 pesticides were observed in the European atmosphere. Low spatial variation of 7 pesticides suggests continental-scale atmospheric dispersal. Based on concentrations in free tropospheric air and at Arctic sites, 22 pesticides were identified to be prone to long-range atmospheric transport, which included 15 substances approved for agricultural use in Europe and 7 banned ones. Comparison between concentrations at remote sites and those found at pesticide source areas suggests long atmospheric lifetimes of atrazine, cyprodinil, spiroxamine, tebuconazole, terbuthylazine, and thiacloprid. In general, our findings suggest that atmospheric transport and persistence of pesticides have been underestimated and that their risk assessment needs to be improved.
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New production (New P, the rate of net primary production (NPP) supported by exogenously supplied limiting nutrients) and net community production (NCP, gross primary production not consumed by community respiration) are closely related but mechanistically distinct processes. They set the carbon balance in the upper ocean and define an upper limit for export from the system. The relationships, relative magnitudes and variability of New P (from 15NO3- uptake), O2 : argon-based NCP and sinking particle export (based on the 238U : 234Th disequilibrium) are increasingly well documented but still not clearly understood. This is especially true in remote regions such as polar marginal ice zones. Here we present a 3-year dataset of simultaneous measurements made at approximately 50 stations along the Western Antarctic Peninsula (WAP) continental shelf in midsummer (January) 2012-2014. Net seasonal-scale changes in water column inventories (0-150 m) of nitrate and iodide were also estimated at the same stations. The average daily rates based on inventory changes exceeded the shorter-term rate measurements. A major uncertainty in the relative magnitude of the inventory estimates is specifying the start of the growing season following sea-ice retreat. New P and NCP(O2) did not differ significantly. New P and NCP(O2) were significantly greater than sinking particle export from thorium-234. We suggest this is a persistent and systematic imbalance and that other processes such as vertical mixing and advection of suspended particles are important export pathways.This article is part of the theme issue 'The marine system of the west Antarctic Peninsula: status and strategy for progress in a region of rapid change'.
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AIMS: Active amyloid-ß (Aß) immunotherapy in Alzheimer's disease (AD) induces removal of Aß and phosphorylated tau (ptau). Glycogen synthase kinase (GSK)-3ß is a kinase, responsible for phosphorylation of tau, activation of which can be induced by phosphorylated double-stranded RNA-dependent protein kinase (pPKR). Using a post-mortem cohort of immunized AD cases, we investigated the effect of Aß immunization on GSK-3ß expression and pPKR. METHODS: We immunostained 11 immunized AD cases and 28 unimmunized AD cases for active, inactive and total GSK-3ß, and for pPKR. Quantification of protein load was performed in the hippocampal region including CA1, subiculum and entorhinal cortex. RESULTS: All three areas showed a significant decrease in the three forms of GSK-3ß (P < 0.05) and a nonsignificant trend towards lower pPKR load in the immunized AD cases compared with the unimmunized AD cases. CONCLUSION: The lower GSK-3ß expression generated by Aß immunotherapy shows evidence of a modification of the signalling pathway induced by GSK-3ß leading to the overall reduction of tau, supporting the contention that in humans, GSK-3ß unifies Aß and tau-related neuropathology.
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Doença de Alzheimer/enzimologia , Doença de Alzheimer/imunologia , Peptídeos beta-Amiloides/imunologia , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/patologia , Vacinas contra Alzheimer/metabolismo , Glicogênio Sintase Quinase 3 beta , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Neurônios/metabolismo , Neurônios/patologia , FosforilaçãoRESUMO
The addition of iron to high-nutrient, low-chlorophyll regions induces phytoplankton blooms that take up carbon. Carbon export from the surface layer and, in particular, the ability of the ocean and sediments to sequester carbon for many years remains, however, poorly quantified. Here we report data from the CROZEX experiment in the Southern Ocean, which was conducted to test the hypothesis that the observed north-south gradient in phytoplankton concentrations in the vicinity of the Crozet Islands is induced by natural iron fertilization that results in enhanced organic carbon flux to the deep ocean. We report annual particulate carbon fluxes out of the surface layer, at three kilometres below the ocean surface and to the ocean floor. We find that carbon fluxes from a highly productive, naturally iron-fertilized region of the sub-Antarctic Southern Ocean are two to three times larger than the carbon fluxes from an adjacent high-nutrient, low-chlorophyll area not fertilized by iron. Our findings support the hypothesis that increased iron supply to the glacial sub-Antarctic may have directly enhanced carbon export to the deep ocean. The CROZEX sequestration efficiency (the amount of carbon sequestered below the depth of winter mixing for a given iron supply) of 8,600 mol mol(-1) was 18 times greater than that of a phytoplankton bloom induced artificially by adding iron, but 77 times smaller than that of another bloom initiated, like CROZEX, by a natural supply of iron. Large losses of purposefully added iron can explain the lower efficiency of the induced bloom(6). The discrepancy between the blooms naturally supplied with iron may result in part from an underestimate of horizontal iron supply.
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Carbono/metabolismo , Ferro/metabolismo , Água do Mar/química , Regiões Antárticas , Clorofila/análise , Clorofila/metabolismo , Clorofila A , Eutrofização , Geografia , Sedimentos Geológicos/química , Oceanos e Mares , Fitoplâncton/metabolismo , Estações do Ano , Fatores de TempoRESUMO
BACKGROUND: It is crucial to include a wide range of the population in clinical trials for the outcome to be applicable in real-world settings. Existing literature indicates that under-served groups, including disabled people, have been excluded from participating in clinical trials without justification. Exclusion from clinical trials exacerbates disparities in healthcare and diminishes the benefits for excluded populations. Therefore, this study was conducted to investigate potential obstacles that prevent disabled people from participating in clinical trials in the United Kingdom (UK). METHODS: The study was carried out through an explanatory sequential mixed methods design. The Imperial Clinical Trials Unit devised and implemented an online questionnaire-based survey (with open/closed-ended questions) and an online focus group discussion. The target population were disabled people, family members/carers of disabled people and staff involved in clinical trials, whereupon the sample was recruited by convenience sampling methods via posters and emails through various networks. The Qualtrics XM survey system was used as the host platform for the online survey, and Microsoft Teams was used for an online focus group discussion. The focus group discussion was conducted to gain a deeper understanding of the themes identified from the survey responses. We analysed responses to the survey via descriptive analysis and used thematic analysis to synthesise the free-text answers from the survey and focus group discussion. RESULTS: We received 45 responses to the survey questionnaire and 5 disabled people took part in a focus group discussion. Our findings highlighted the differences between the perspectives of researchers and those "being researched" and different types of barriers experienced by disabled people: opportunity barriers (inadequate recruitment strategy and ambiguous eligibility criteria), awareness barriers (perception of disability) and acceptance/refusal barriers (available support and adjustment, and sharing of trial results). CONCLUSION: Our findings support perspectives drawn from the Ford Framework regarding the need to consider all barriers, not just up to the point of enrolment into trials but also beyond the point of inclusion in clinical trials. We support calls for the introduction of legislation on including disabled people in clinical trials, implementation of industry/community-wide participatory approaches and the development of guidelines, a combined public-private approach.
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Ensaios Clínicos como Assunto , Pessoas com Deficiência , Grupos Focais , Seleção de Pacientes , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Inquéritos e Questionários , Reino Unido , Sujeitos da Pesquisa/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Atitude do Pessoal de Saúde , Pesquisadores/psicologia , Idoso , Projetos de PesquisaRESUMO
Background: Adolescence is a vulnerable developmental period, characterized by high rates of mental health concerns, yet few adolescents receive treatment. Public libraries support adolescents by providing them with access to teen programming, technological resources, and have recently been providing mental health services. Digital mental health (DMH) services may help libraries provide scalable mental health solutions for their adolescent patrons and could be well positioned to address the mental health needs of historically underrepresented racial and ethnic (HURE) adolescents; however, little research has been conducted on the compatibility of DMH services with adolescent patron mental health needs or resource needs of library workers supporting them. Methods: The research team formed a partnership with a public library, which serves a large HURE adolescent population. We conducted needs assessment and implementation readiness interviews with 17 library workers, including leadership, librarians, and workers with specialized areas of practice. Interview questions focused on library infrastructure, as well as library needs and preferences around the design and implementation of DMH services for adolescents. We used the Consolidated Framework for Implementation Research as guiding implementation determinant framework to code and analyze the interview transcripts. Results: Our findings revealed library workers play an important role in guiding patrons to desired resources and share a goal of implementing adolescent DMH resources into the library and elevating marginalized adolescents' voices. Existing library resources, such as the library's role as a safe space for adolescents in the community, close relationships with external and community organizations, and availability of no-cost technological resources, could help facilitate the implementation of DMH services. Barriers related to community buy-in, mental health stigma, and library worker confidence in supporting adolescent mental health could affect service implementation. Conclusions: Our findings suggest public libraries are highly promising settings to deploy DMH services for adolescents. We identified important determinants that may impact the implementation of DMH services in public library settings. Special considerations are needed to design services to meet the mental health needs of HURE adolescent populations and those adolescents' most experiencing health inequities.
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This paper reviews our knowledge of the measurement and modeling of mineral dust emissions to the atmosphere, its transport and deposition to the ocean, the release of iron from the dust into seawater, and the possible impact of that nutrient on marine biogeochemistry and climate. Of particular concern is our poor understanding of the mechanisms and quantities of dust deposition as well as the extent of iron solubilization from the dust once it enters the ocean. Model estimates of dust deposition in remote oceanic regions vary by more than a factor of 10. The fraction of the iron in dust that is available for use by marine phytoplankton is still highly uncertain. There is an urgent need for a long-term marine atmospheric surface measurement network, spread across all oceans. Because the southern ocean is characterized by large areas with high nitrate but low chlorophyll surface concentrations, that region is particularly sensitive to the input of dust and iron. Data from this region would be valuable, particularly at sites downwind from known dust source areas in South America, Australia, and South Africa. Coordinated field experiments involving both atmospheric and marine measurements are recommended to address the complex and interlinked processes and role of dust/Fe fertilization on marine biogeochemistry and climate.
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Atmosfera , Poeira , Minerais , Oceanos e Mares , Atmosfera/química , Austrália , Clorofila , Poeira/análise , Ferro/química , Biologia Marinha/métodos , Modelos Teóricos , Pesquisa/tendências , Água do Mar/química , África do SulRESUMO
We have compiled and analyzed a comprehensive data set of field observations of iodine speciation in marine aerosol. The soluble iodine content of fine aerosol (PM1) is dominated by soluble organic iodine (SOI; â¼50%) and iodide (â¼30%), while the coarse fraction is dominated by iodate (â¼50%), with nonnegligible amounts of iodide (â¼20%). The SOI fraction shows an equatorial maximum and minima coinciding with the ocean "deserts," which suggests a link between soluble iodine speciation in aerosol and ocean productivity. Among the major aerosol ions, organic anions and non-sea-salt sulfate show positive correlations with SOI in PM1. Alkali cations are positively correlated to iodate and negatively correlated with SOI and iodide in coarse aerosol. These relationships suggest that under acidic conditions iodate is reduced to HOI, which reacts with organic matter to form SOI, a possible source of iodide. In less acidic sea-salt or dust-rich coarse aerosols, HOI oxidation to iodate and reaction with organic matter likely compete.
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Anthropogenic emissions to the atmosphere have increased the flux of nutrients, especially nitrogen, to the ocean, but they have also altered the acidity of aerosol, cloud water, and precipitation over much of the marine atmosphere. For nitrogen, acidity-driven changes in chemical speciation result in altered partitioning between the gas and particulate phases that subsequently affect long-range transport. Other important nutrients, notably iron and phosphorus, are affected, because their soluble fractions increase upon exposure to acidic environments during atmospheric transport. These changes affect the magnitude, distribution, and deposition mode of individual nutrients supplied to the ocean, the extent to which nutrient deposition interacts with the sea surface microlayer during its passage into bulk seawater, and the relative abundances of soluble nutrients in atmospheric deposition. Atmospheric acidity change therefore affects ecosystem composition, in addition to overall marine productivity, and these effects will continue to evolve with changing anthropogenic emissions in the future.
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OBJECTIVE: To investigate the association of serum levels of proangiogenic cytokines with different indices of social support and loneliness by measuring the levels of expression of two important proangiogenic cytokines, vascular endothelial growth factor (VEGF), and interleukin-6 in tumors of colon and rectum. Lack of social support has been prospectively associated with cancer progression. METHODS: Fifty-one newly diagnosed patients with colorectal tumors (mean age, 68.3 years) completed two measures of loneliness 1 to 2 days before their surgical treatment. The first was an explicit self-report questionnaire, which tapped into negative feelings as a result of low social support. The second was a standardized computer-based task, which measured loneliness implicitly. Immunohistochemical analyses were performed on tumor tissues post surgery to determine the expression of cytokines. RESULTS: Logistic regression showed that higher levels of implicit loneliness independently predicted stronger expression of VEGF, controlling for Dukes stage and explicit loneliness, both of which were nonsignificant predictors. No significant relationships were found between the loneliness measures and interleukin-6. CONCLUSIONS: The results of this study suggest VEGF to be an angiogenic mechanism through which loneliness may lead to worse cancer-related outcomes. Implications are discussed in terms of devising targeted psychosocial and immunotherapeutic interventions for cancer patients with low social support.
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Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/psicologia , Solidão/psicologia , Apoio Social , Fator A de Crescimento do Endotélio Vascular/sangue , 3,3'-Diaminobenzidina , Hormônio Adrenocorticotrópico , Idoso , Biomarcadores/sangue , Neoplasias Colorretais/sangue , Feminino , Humanos , Imuno-Histoquímica , Interleucina-6/sangue , Masculino , Prognóstico , Índice de Gravidade de Doença , Sistema Nervoso Simpático , Carga TumoralRESUMO
This correction is to add the middle initials of all authors, which were inadvertently omitted from the original article.
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Head injury is a growing concern within contact sports, including American football. Computational tools such as finite element (FE) models provide an avenue for researchers to study, and potentially optimize safety tools, such as helmets. The goal of this study was to develop an accurate representative helmet model that could be used in further study of head injury to mitigate the toll of concussions in contact sports. An FE model of a Schutt Air XP Pro football helmet was developed through three major steps: geometry development, material characterization, and model validation. The fully assembled helmet model was fit onto a Hybrid III dummy head-neck model and National Operating Committee on Standards for Athletic Equipment (NOCSAE) head model and validated through a series of 67 representative impacts similar to those experienced by a football player. The kinematic and kinetic response of the model was compared to the response of the physical experiments, which included force, head linear acceleration, head angular velocity, and carriage acceleration. The outputs between the model and the physical tests were quantitatively evaluated using CORelation and Analysis (CORA), amounting to an overall averaged score of 0.76. The model described in this study has been extensively validated and can function as a building block for innovation in player safety.
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Traumatismos em Atletas/prevenção & controle , Traumatismos Craniocerebrais/prevenção & controle , Futebol Americano/lesões , Dispositivos de Proteção da Cabeça , Modelos Teóricos , Análise de Falha de Equipamento , Análise de Elementos Finitos , Equipamentos EsportivosRESUMO
Atmospheric deposition is a source of potentially bioavailable iron (Fe) and thus can partially control biological productivity in large parts of the ocean. However, the explanation of observed high aerosol Fe solubility compared to that in soil particles is still controversial, as several hypotheses have been proposed to explain this observation. Here, a statistical analysis of aerosol Fe solubility estimated from four models and observations compiled from multiple field campaigns suggests that pyrogenic aerosols are the main sources of aerosols with high Fe solubility at low concentration. Additionally, we find that field data over the Southern Ocean display a much wider range in aerosol Fe solubility compared to the models, which indicate an underestimation of labile Fe concentrations by a factor of 15. These findings suggest that pyrogenic Fe-containing aerosols are important sources of atmospheric bioavailable Fe to the open ocean and crucial for predicting anthropogenic perturbations to marine productivity.
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Ferro/química , Aerossóis , Oceano Atlântico , Atmosfera/química , Poeira , Óxido Ferroso-Férrico/química , Oceano Índico , Modelos Químicos , Concentração Osmolar , Solo/química , SolubilidadeRESUMO
The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are now being implemented in air quality models, but these are currently a major source of uncertainty. Relatively little observational data is available to estimate the global surface iodide concentrations, and this data has not hitherto been openly available in a collated, digital form. Here we present all available sea surface (<20 m depth) iodide observations. The dataset includes values digitised from published manuscripts, published and unpublished data supplied directly by the originators, and data obtained from repositories. It contains 1342 data points, and spans latitudes from 70°S to 68°N, representing all major basins. The data may be used to model sea surface iodide concentrations or as a reference for future observations.
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Metal dissolution from atmospheric aerosol deposition to the oceans is important in enhancing and inhibiting phytoplankton growth rates and modifying plankton community structure, thus impacting marine biogeochemistry. Here we review the current state of knowledge on the causes and effects of the leaching of multiple trace metals from natural and anthropogenic aerosols. Aerosol deposition is considered both on short timescales over which phytoplankton respond directly to aerosol metal inputs, as well as longer timescales over which biogeochemical cycles are affected by aerosols.
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Aerossóis/análise , Organismos Aquáticos/crescimento & desenvolvimento , Poluentes Ambientais/análise , Metais/análise , Oligoelementos/análise , Ecossistema , Sedimentos Geológicos/química , Sedimentos Geológicos/microbiologia , Modelos Teóricos , Água do Mar/química , Água do Mar/microbiologia , Microbiologia da ÁguaRESUMO
Iron (Fe) is an essential micronutrient for marine microbial organisms, and low supply controls productivity in large parts of the world's ocean. The high latitude North Atlantic is seasonally Fe limited, but Fe distributions and source strengths are poorly constrained. Surface ocean dissolved Fe (DFe) concentrations were low in the study region (<0.1 nM) in summer 2010, with significant perturbations during spring 2010 in the Iceland Basin as a result of an eruption of the Eyjafjallajökull volcano (up to 2.5 nM DFe near Iceland) with biogeochemical consequences. Deep water concentrations in the vicinity of the Reykjanes Ridge system were influenced by pronounced sediment resuspension, with indications for additional inputs by hydrothermal vents, with subsequent lateral transport of Fe and manganese plumes of up to 250-300 km. Particulate Fe formed the dominant pool, as evidenced by 4-17 fold higher total dissolvable Fe compared with DFe concentrations, and a dynamic exchange between the fractions appeared to buffer deep water DFe. Here we show that Fe supply associated with deep winter mixing (up to 103 nmol m-2 d-1) was at least ca. 4-10 times higher than atmospheric deposition, diffusive fluxes at the base of the summer mixed layer, and horizontal surface ocean fluxes.
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Anthropogenic nitrogen (N) emissions to the atmosphere have increased significantly the deposition of nitrate (NO3-) and ammonium (NH4+) to the surface waters of the open ocean, with potential impacts on marine productivity and the global carbon cycle. Global-scale understanding of the impacts of N deposition to the oceans is reliant on our ability to produce and validate models of nitrogen emission, atmospheric chemistry, transport and deposition. In this work, ~2900 observations of aerosol NO3- and NH4+ concentrations, acquired from sampling aboard ships in the period 1995 - 2012, are used to assess the performance of modelled N concentration and deposition fields over the remote ocean. Three ocean regions (the eastern tropical North Atlantic, the northern Indian Ocean and northwest Pacific) were selected, in which the density and distribution of observational data were considered sufficient to provide effective comparison to model products. All of these study regions are affected by transport and deposition of mineral dust, which alters the deposition of N, due to uptake of nitrogen oxides (NOx) on mineral surfaces. Assessment of the impacts of atmospheric N deposition on the ocean requires atmospheric chemical transport models to report deposition fluxes, however these fluxes cannot be measured over the ocean. Modelling studies such as the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), which only report deposition flux are therefore very difficult to validate for dry deposition. Here the available observational data were averaged over a 5° × 5° grid and compared to ACCMIP dry deposition fluxes (ModDep) of oxidised N (NOy) and reduced N (NHx) and to the following parameters from the TM4-ECPL (TM4) model: ModDep for NOy, NHx and particulate NO3- and NH4+, and surface-level particulate NO3- and NH4+ concentrations. As a model ensemble, ACCMIP can be expected to be more robust than TM4, while TM4 gives access to speciated parameters (NO3- and NH4+) that are more relevant to the observed parameters and which are not available in ACCMIP. Dry deposition fluxes (CalDep) were calculated from the observed concentrations using estimates of dry deposition velocities. Model - observation ratios, weighted by grid-cell area and numbers of observations, (RA,n) were used to assess the performance of the models. Comparison in the three study regions suggests that TM4 over-estimates NO3- concentrations (RA,n = 1.4 - 2.9) and under-estimates NH4+ concentrations (RA,n = 0.5 - 0.7), with spatial distributions in the tropical Atlantic and northern Indian Ocean not being reproduced by the model. In the case of NH4+ in the Indian Ocean, this discrepancy was probably due to seasonal biases in the sampling. Similar patterns were observed in the various comparisons of CalDep to ModDep (RA,n = 0.6 - 2.6 for NO3-, 0.6 - 3.1 for NH4+). Values of RA,n for NHx CalDep - ModDep comparisons were approximately double the corresponding values for NH4+ CalDep - ModDep comparisons due to the significant fraction of gas-phase NH3 deposition incorporated in the TM4 and ACCMIP NHx model products. All of the comparisons suffered due to the scarcity of observational data and the large uncertainty in dry deposition velocities used to derive deposition fluxes from concentrations. These uncertainties have been a major limitation on estimates of the flux of material to the oceans for several decades. Recommendations are made for improvements in N deposition estimation through changes in observations, modelling and model - observation comparison procedures. Validation of modelled dry deposition requires effective comparisons to observable aerosol-phase species concentrations and this cannot be achieved if model products only report dry deposition flux over the ocean.
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Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30-50% of natural Pb, derived from mineral dust, are observed in Atlantic surface waters, reflecting the success of the global effort to reduce anthropogenic Pb emissions. The observation of mineral dust derived Pb in surface waters is governed by the elevated atmospheric mineral dust concentration of the North African dust plume and the dominance of dry deposition for the atmospheric aerosol flux to surface waters. Given these specific regional conditions, emissions from anthropogenic activities will remain the dominant global marine Pb source, even in the absence of leaded petrol combustion.
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Recent studies have highlighted the impact of sea surface iodide concentrations on the deposition of ozone to the sea surface and the sea to air flux of reactive iodine. The use of models to predict this flux demands accurate, spatially distributed sea surface iodide concentrations, but to date, the observational data required to support this is sparse and mostly arises from independent studies conducted on small geographical and temporal scales. We have compiled the available measurements of sea surface iodide to produce a data set spanning latitudes from 69°S to 66°N, which reveals a coherent, large scale distribution pattern, with highest concentrations observed in tropical waters. Relationships between iodide concentration and more readily available parameters (chlorophyll, nitrate, sea surface temperature, salinity, mixed layer depth) are evaluated as tools to predict iodide concentration. Of the variables tested, sea surface temperature is the strongest predictor of iodide concentration. Nitrate was also strongly inversely associated with iodide concentration, but chlorophyll-a was not.