319 research outputs found
Subacute exposure of rats by metal oxide nanoparticles through the airways: general toxicity and neuro-functional effects
In order to create an animal model of human inhalational exposure by industrial trAct
metal fumes, nanoparticulate metal oxides (MnO2
, CdO2
, PbO) were synthesized and instilled
into the trachea of rats 5 times a week for 6 weeks (metal doses per kg b.w.: 2.63 and 5.26 mg
Mn; 0.04 and 0.4 mg Cd; 2 and 4 mg Pb). At the end, the rats’ body weight gain during the treatment was determined, the animals had an open field session to investigate their spontaneous
motility, and finally spontaneous and stimulus-evoked cortical activity was recorded in urethane
anaesthesia. Mn caused decrease of open field ambulation and rearing, Cd had no effect,
whereas Pb caused decreased rearing and increased ambulation. Spontaneous cortical activity
was shifted to higher frequencies with each metal. Cortical evoked potentials had lengthened
latency, mainly with Mn and Cd; and increased frequency dependence with Cd and Pb but hardly
with Mn. The effects proved indirectly that the metal content of the nanoparticles had access
form the airways to the CNS. Our method seems suitable for modelling human nervous system
damage due to inhaled nanoparticles
Research on Roma health and access to healthcare: state of the art and future challenges
Health inequalities experienced by Roma people living in Europe presents a persisting challenge for health care programs. Research studies on Roma health conditions reveal that: (1) Roma people suffer from poorer health and unhealthier living conditions compared to majority populations, (2) better data are needed to explain the Roma health gap and design better interventions to reduce this gap, and (3) the poor health of Roma is closely linked to the social determinants of health.This editorial published in the International Journal of Public Health discusses lessons learned from recent research findings and outlines a number of challenges in exploring and addressing the various mechanisms that contribute to the health gap between Roma and majority populations.The editorial was authored by Alina Covaci of the Open Society Foundations' Roma Health Project and Maria Eva Foldes of the Tilburg Law and Economics Center in the Netherlands
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Improvements in pollutant monitoring: Optimizing silicone for co-deployment with polyethylene passive sampling devices
Sequestering semi-polar compounds can be difficult with low-density polyethylene (LDPE), but those pollutants may be more efficiently absorbed using silicone. In this work, optimized methods for cleaning, infusing reference standards, and polymer extraction are reported along with field comparisons of several silicone materials for polycyclic aromatic hydrocarbons (PAHs) and pesticides. In a final field demonstration, the most optimal silicone material is coupled with LDPE in a large-scale study to examine PAHs in addition to oxygenated-PAHs (OPAHs) at a Superfund site. OPAHs exemplify a sensitive range of chemical properties to compare polymers (log K[subscript ow] 0.2–5.3), and transformation products of commonly studied parent PAHs. On average, while polymer concentrations differed nearly 7-fold, water-calculated values were more similar (about 3.5-fold or less) for both PAHs (17) and OPAHs (7). Individual water concentrations of OPAHs differed dramatically between silicone and LDPE, highlighting the advantages of choosing appropriate polymers and optimized methods for pollutant monitoring.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/environmental-pollution/Keywords: OPAHs, Silicone, Oxygenated-PAHs, Passive sampling, Polyethylene, PAHs, Pesticide
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Women's dietary changes before and during pregnancy: A systematic review
Background: dietary intake before and during pregnancy has significant health outcomes for both mother and child, including a healthy gestational weight gain. To ensure effective interventions are successfully developed to improve dietary intake during pregnancy, it is important to understand what dietary changes pregnant women make without intervention.
Aims: to systematically identify and review studies examining women's dietary changes before and during pregnancy and to identify characteristics of the women making these changes.
Methods: a systematic search strategy was employed using three databases (Web of Science, CINAHL and PubMed) in May 2016. Search terms included those relating to preconception, pregnancy and diet. All papers were quality assessed using the Scottish Intercollegiate Guidelines Network methodology checklist for cohort studies.The search revealed 898 articles narrowed to full-text review of 23 studies. In total, 11 research articles were included in the review, describing nine different studies. The findings were narratively summarised in line with the aims of the review.
Findings: the included studies showed marked heterogeneity, which impacts on the findings. However, the majority report an increase in energy intake (kcal or kJ) during pregnancy. Of the studies that reported changes through food group comparisons, a majority reported a significant increase in fruit and vegetable consumption, a decrease in egg consumption, a decrease in fried and fast food consumption and a decrease in coffee and tea consumption from before to during pregnancy. The characteristics of the women participating in these studies, suggest that age, education and pregnancy intention are associated with healthier dietary changes; however these factors were only assessed in a small number of studies.
Key conclusions: the 11 included articles show varied results in dietary intake during pregnancy as compared to before. More research is needed regarding who makes these healthy changes, this includes consistency regarding measurement tools, outcomes and time points.
Implications for practice: Midwives as well as intervention developers need to be aware of the dietary changes women may spontaneously engage in when becoming pregnant, so that care and interventions can build on these
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Impact of natural gas extraction on PAH levels in ambient air
After publication the authors discovered a mistake in the air concentration calculations. PAH air concentrations reported in the original article are therefore incorrect. The calculation error resulted from using incorrect units of the ideal gas constant, and improper cell linkages in the spreadsheet used to adjust air concentrations for sampling temperature. Correcting this error changes air concentrations significantly relative to those reported in the published article. This correction also changes some of the conclusions reported in the original article.
Due to the impact of this correction on the reported findings, all authors retract the original article. The original article was published on March 26, 2015 and retracted on June 29, 2016.Natural gas extraction, often referred to as “fracking,” has increased rapidly in the U.S. in recent years. To address potential health impacts, passive air samplers were deployed in a rural community heavily affected by the natural gas boom. Samplers were analyzed for 62 polycyclic aromatic hydrocarbons (PAHs). Results were grouped based on distance from each sampler to the nearest active well. PAH levels were highest when samplers were closest to active wells. Additionally, PAH levels closest to natural gas activity were an order of magnitude higher than levels previously reported in rural areas. Sourcing ratios indicate that PAHs were predominantly petrogenic, suggesting that elevated PAH levels were influenced by direct releases from the earth. Quantitative human health risk assessment estimated the excess lifetime cancer risks associated with exposure to the measured PAHs. Closest to active wells, the risk estimated for maximum residential exposure was 2.9 in 10,000, which is above the U.S. EPA’s acceptable risk level. Overall, risk estimates decreased 30% when comparing results from samplers closest to active wells to those farthest. This work suggests that natural gas extraction may be contributing significantly to PAHs in air, at levels that are relevant to human health
Ground, Proximal, and Satellite Remote Sensing of Soil Moisture
Soil moisture (SM) is a key hydrologic state variable that is of significant importance for numerous Earth and environmental science applications that directly impact the global environment and human society. Potential applications include, but are not limited to, forecasting of weather and climate variability; prediction and monitoring of drought conditions; management and allocation of water resources; agricultural plant production and alleviation of famine; prevention of natural disasters such as wild fires, landslides, floods, and dust storms; or monitoring of ecosystem response to climate change. Because of the importance and wide‐ranging applicability of highly variable spatial and temporal SM information that links the water, energy, and carbon cycles, significant efforts and resources have been devoted in recent years to advance SM measurement and monitoring capabilities from the point to the global scales. This review encompasses recent advances and the state‐of‐the‐art of ground, proximal, and novel SM remote sensing techniques at various spatial and temporal scales and identifies critical future research needs and directions to further advance and optimize technology, analysis and retrieval methods, and the application of SM information to improve the understanding of critical zone moisture dynamics. Despite the impressive progress over the last decade, there are still many opportunities and needs to, for example, improve SM retrieval from remotely sensed optical, thermal, and microwave data and opportunities for novel applications of SM information for water resources management, sustainable environmental development, and food security
Enhancement of stress tolerance in transgenic tobacco plants constitutively expressing AtIpk2β, an inositol polyphosphate 6-/3-kinase from Arabidopsis thaliana
Inositol phosphates (IPs) and their turnover products have been implicated to play important roles in stress signaling in eukaryotic cells. In higher plants genes encoding inositol polyphosphate kinases have been identified previously, but their physiological functions have not been fully resolved. Here we expressed Arabidopsis inositol polyphosphate 6-/3-kinase (AtIpk2β) in two heterologous systems, i.e. the yeast Saccharomycescerevisiae and in tobacco (Nicotiana tabacum), and tested the effect on abiotic stress tolerance. Expression of AtIpk2β rescued the salt-, osmotic- and temperature-sensitive growth defects of a yeast mutant strain (arg82Δ) that lacks inositol polyphosphate multikinase activity encoded by the ARG82/IPK2 gene. Transgenic tobacco plants constitutively expressing AtIpk2β under the control of the Cauliflower Mosaic Virus 35S promoter were generated and found to exhibit improved tolerance to diverse abiotic stresses when compared to wild type plants. Expression patterns of various stress responsive genes were enhanced, and the activities of anti-oxidative enzymes were elevated in transgenic plants, suggesting a possible involvement of AtIpk2β in plant stress responses
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
State of the climate in 2013
In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Niña or El Niño events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earths surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series. © 2014, American Meteorological Society. All rights reserved
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