781 research outputs found

    Emissions of transboundary air pollutants in the Netherlands 1990-2012 : Informative Inventory Report 2014

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    Emissies Nederland blijven in 2012 onder nationale plafonds De uitstoot van stikstofoxiden (NOx), ammoniak, zwaveldioxide en niet-methaan vluchtige organische stoffen (NMVOS) is in 2012 in Nederland licht gedaald. Daarmee bleef de uitstoot onder de maxima die de Europese Unie daaraan sinds 2010 stelt. Nederland voldoet daardoor, net als in 2011, aan de vier 'nationale emissieplafonds' (NEC) voor deze stoffen. Dit blijkt uit de Nederlandse emissiecijfers van grootschalige luchtverontreinigende stoffen. Het RIVM verzamelt en analyseert deze cijfers. Behalve bovengenoemde stoffen gaat het om de uitstoot van koolmonoxide, fijn stof (PM10), zware metalen en persistente organische stoffen (POP's). De uitstoot van al deze stoffen is tussen 1990 en 2012 gedaald. Dit komt vooral door schonere auto's en brandstoffen en door emissiebeperkende maatregelen van industriële sectoren. Meer kilometers door bromfietsen Door de jaren heen zijn de methoden om de emissies te berekenen verbeterd, wat nu resulteert in nauwkeurigere cijfers. De emissies van bromfietsen en motorfietsen zijn afhankelijk van het aantal gereden kilometers per jaar en daar is nu beter inzicht in. Het totale aantal gereden kilometers door bromfietsen blijkt in de afgelopen jaren bijna twee keer zo hoog is als werd gedacht. Daarmee is de uitstoot van schadelijke stoffen navenant hoger. Ten opzichte van andere typ voertuigen blijven bromfietsen echter een relatief kleine emissiebron en dragen ze beperkt bij aan de totale nationale emissies. In steden zijn ze wel een relevante bron. Het aantal gereden kilometers door motorfietsen, en daarmee de uitstoot, blijft in lijn met eerdere inzichten. Vrachtauto's zwaarder beladen De uitstoot van schadelijke stoffen door vrachtauto's is voor het eerst berekend op basis van recente inzichten in het gewicht van vrachtauto's. Trekker-opleggers blijken zwaarder beladen dan tot nu toe werd verondersteld. Ook rijden vrachtauto's vaker met een aanhanger dan tot nu toe werd aangenomen, waardoor ze zwaarder zijn. Een hoger gewicht betekent een hoger brandstofverbruik, en veelal ook een hogere uitstoot per gereden kilometer. De uitstoot van PM10 door vrachtauto's is hierdoor circa 5 procent hoger dan in de vorige IIR-rapportage. Hogere emissies ammoniak De uitstoot van ammoniak blijkt hoger dan eerder werd verondersteld vanwege enkele nieuwe inzichten; de cijfers zijn hierdoor vanaf 1997 bijgesteld. Zo worden luchtwassers, die voornamelijk op varkensstallen zitten, niet altijd gebruikt. Ook is vanaf 2002 in melkveestallen het leefoppervlak per dier toegenomen. Door het grotere contactoppervlak van mest met lucht wordt meer ammoniak uitgestoten. Door de aangepaste aannames is het nationale totaal met 6,6 kiloton verhoogd ten opzichte van 2011.Emissions the Netherlands in 2012 remain under national ceilings Emissions of nitrogen oxides (NOx), ammonia, sulphur dioxide and non-methane volatile organic compounds (NMVOC) in the Netherlands have slightly decreased in 2012. Consequently, the emissions stayed below the caps the European Union has set from 2010. Herewith, the Netherlands comply with all four so-called emission ceilings (NEC). This has become apparent from the emission data on air pollutants from the Netherlands. RIVM collects and reports these data. Besides above-mentioned substances, emissions of carbon monoxide, particulate matter (PM10), heavy metals and persistent organic pollutants (POPs) have been reported. The emissions of all substances have decreased in the 1990 - 2012 period. The downward trend may in particular be attributed to cleaner fuels, cleaner car engines and to emission reductions in the industrial sectors. More kilometres by mopeds Over the years emission calculation methods have been improved, resulting in higher data accuracy. In 2012, the emissions from mopeds and motorcycles have been calculated, based on improved knowledge of the mileages. The total number of kilometres driven by mopeds appears to have been nearly twice as high in recent years. As a result, the emissions of pollutants are proportionally higher. In relation to the total number of vehicles, the number of mopeds however remains relatively low and their contribution to the total national emissions is limited. In cities, they are a relevant source. The mileages by motorcycles, and consequently their emissions remain in line with previous insights. Heavy-duty vehicles carry heavier loads Emissions of pollutants by heavy-duty trucks have for the first time been calculated on the basis of recent insights in truck loads. Tractor-trailer combinations appear to carry heavier loads and the fraction of trailers behind rigid trucks is larger than previously assumed. A heavier load means a higher fuel use and for most substances a higher emission per kilometre driven. PM10 emissions by heavy-duty trucks are about 5 percent higher than in the previous IIR report. Higher agricultural ammonia emissions Agricultural ammonia emissions appear to be higher than previously assumed because of new insights. Air scrubbers on animal housing (predominantly pigs) were not always in use or even employed. Since 2002, the living space per animal has increased for dairy cattle housing. This resulted in a higher contact surface manure-air and thus more ammonia emitted. The new insights have raised the national total of ammonia emissions by about 6 percent compared to 2011

    Strain- and plasmid-level deconvolution of a synthetic metagenome by sequencing proximity ligation products

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    Metagenomics is a valuable tool for the study of microbial communities but has been limited by the difficulty of “binning” the resulting sequences into groups corresponding to the individual species and strains that constitute the community. Moreover, there are presently no methods to track the flow of mobile DNA elements such as plasmids through communities or to determine which of these are co-localized within the same cell. We address these limitations by applying Hi-C, a technology originally designed for the study of three-dimensional genome structure in eukaryotes, to measure the cellular co-localization of DNA sequences. We leveraged Hi-C data generated from a simple synthetic metagenome sample to accurately cluster metagenome assembly contigs into groups that contain nearly complete genomes of each species. The Hi-C data also reliably associated plasmids with the chromosomes of their host and with each other. We further demonstrated that Hi-C data provides a long-range signal of strain-specific genotypes, indicating such data may be useful for high-resolution genotyping of microbial populations. Our work demonstrates that Hi-C sequencing data provide valuable information for metagenome analyses that are not currently obtainable by other methods. This metagenomic Hi-C method could facilitate future studies of the fine-scale population structure of microbes, as well as studies of how antibiotic resistance plasmids (or other genetic elements) mobilize in microbial communities. The method is not limited to microbiology; the genetic architecture of other heterogeneous populations of cells could also be studied with this technique

    Meeting report : GBIF hackathon-workshop on Darwin Core and sample data (22-24 May 2013)

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    © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Standards in Genomic Sciences 9 (2014): 585-598, doi:10.4056/sigs.4898640.The workshop-hackathon was convened by the Global Biodiversity Information Facility (GBIF) at its secretariat in Copenhagen over 22-24 May 2013 with additional support from several projects (RCN4GSC, EAGER, VertNet, BiSciCol, GGBN, and Micro B3). It assembled a team of experts to address the challenge of adapting the Darwin Core standard for a wide variety of sample data. Topics addressed in the workshop included 1) a review of outstanding issues in the Darwin Core standard, 2) issues relating to publishing of biodiversity data through Darwin Core Archives, 3) use of Darwin Core Archives for publishing sample and monitoring data, 4) the case for modifying the Darwin Core Text Guide specification to support many-to-many relations, and 5) the generalization of the Darwin Core Archive to a “Biodiversity Data Archive”. A wide variety of use cases were assembled and discussed in order to inform further developments.We gratefully acknowledge support from the Global Biodiversity Information Facility (GBIF), from the Global Genome Biodiversity Network (GGBN), from the EU 7FP Biodiversity, Bioinformatics, Biotechnology project (Micro B3), and from the US National Science Foundation (NSF) through the following grants: DBI-0840989 [Research Coordination Network for the Ge-nomic Standards Consortium (RCN4GSC)], IIS-1255035 [EAGER: An Interoperable Information Infrastructure for Biodiversity Research (I3BR)], ABI Development: Collaborative Research: VertNet, a New Model for Bio-diversity Networks (DBI-1062193), and Collaborative Research: BiSciCol Tracker: Towards a tagging and tracking infrastructure for biodiversity science collec-tions (DBI-0956426)

    Absence of system xc⁻ on immune cells invading the central nervous system alleviates experimental autoimmune encephalitis

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    Background: Multiple sclerosis (MS) is an autoimmune demyelinating disease that affects the central nervous system (CNS), leading to neurodegeneration and chronic disability. Accumulating evidence points to a key role for neuroinflammation, oxidative stress, and excitotoxicity in this degenerative process. System x(c)- or the cystine/glutamate antiporter could tie these pathological mechanisms together: its activity is enhanced by reactive oxygen species and inflammatory stimuli, and its enhancement might lead to the release of toxic amounts of glutamate, thereby triggering excitotoxicity and neurodegeneration. Methods: Semi-quantitative Western blotting served to study protein expression of xCT, the specific subunit of system x(c)-, as well as of regulators of xCT transcription, in the normal appearing white matter (NAWM) of MS patients and in the CNS and spleen of mice exposed to experimental autoimmune encephalomyelitis (EAE), an accepted mouse model of MS. We next compared the clinical course of the EAE disease, the extent of demyelination, the infiltration of immune cells and microglial activation in xCT-knockout (xCT(-/-)) mice and irradiated mice reconstituted in xCT(-/-) bone marrow (BM), to their proper wild type (xCT(+/+)) controls. Results: xCT protein expression levels were upregulated in the NAWM of MS patients and in the brain, spinal cord, and spleen of EAE mice. The pathways involved in this upregulation in NAWM of MS patients remain unresolved. Compared to xCT(+/+) mice, xCT(-/-) mice were equally susceptible to EAE, whereas mice transplanted with xCT(-/-) BM, and as such only exhibiting loss of xCT in their immune cells, were less susceptible to EAE. In none of the above-described conditions, demyelination, microglial activation, or infiltration of immune cells were affected. Conclusions: Our findings demonstrate enhancement of xCT protein expression in MS pathology and suggest that system x(c)- on immune cells invading the CNS participates to EAE. Since a total loss of system x(c)- had no net beneficial effects, these results have important implications for targeting system x(c)- for treatment of MS

    Experimental evolution reveals that sperm competition intensity selects for longer, more costly sperm

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    It is the differences between sperm and eggs that fundamentally underpin the differences between the sexes within reproduction. For males, it is theorized that widespread sperm competition leads to selection for investment in sperm numbers, achieved by minimizing sperm size within limited resources for spermatogenesis in the testis. Here, we empirically examine how sperm competition shapes sperm size, after more than 77 generations of experimental selection of replicate lines under either high or low sperm competition intensities in the promiscuous flour beetle Tribolium castaneum. After this experimental evolution, populations had diverged significantly in their sperm competitiveness, with sperm in ejaculates from males evolving under high sperm competition intensities gaining 20% greater paternity than sperm in ejaculates from males that had evolved under low sperm competition intensity. Males did not change their relative investment into sperm production following this experimental evolution, showing no difference in testis sizes between high and low intensity regimes. However, the more competitive males from high sperm competition intensity regimes had evolved significantly longer sperm and, across six independently selected lines, there was a significant association between the degree of divergence in sperm length and average sperm competitiveness. To determine whether such sperm elongation is costly, we used dietary restriction experiments, and revealed that protein-restricted males produced significantly shorter sperm. Our findings therefore demonstrate that sperm competition intensity can exert positive directional selection on sperm size, despite this being a costly reproductive trait

    Advances in research on the use of biochar in soil for remediation: a review

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    Purpose: Soil contamination mainly from human activities remains a major environmental problem in the contemporary world. Significant work has been undertaken to position biochar as a readily-available material useful for the management of contaminants in various environmental media notably soil. Here, we review the increasing research on the use of biochar in soil for the remediation of some organic and inorganic contaminants.  Materials and methods: Bibliometric analysis was carried out within the past 10 years to determine the increasing trend in research related to biochar in soil for contaminant remediation. Five exemplar contaminants were reviewed in both laboratory and field-based studies. These included two inorganic (i.e., As and Pb) and three organic classes (i.e., sulfamethoxazole, atrazine, and PAHs). The contaminants were selected based on bibliometric data and as representatives of their various contaminant classes. For example, As and Pb are potentially toxic elements (anionic and cationic, respectively), while sulfamethoxazole, atrazine, and PAHs represent antibiotics, herbicides, and hydrocarbons, respectively.  Results and discussion: The interaction between biochar and contaminants in soil is largely driven by biochar precursor material and pyrolysis temperature as well as some characteristics of the contaminants such as octanol-water partition coefficient (KOW) and polarity. The structural and chemical characteristics of biochar in turn determine the major sorption mechanisms and define biochar’s suitability for contaminant sorption. Based on the reviewed literature, a soil treatment plan is suggested to guide the application of biochar in various soil types (paddy soils, brownfield, and mine soils) at different pH levels (4–5.5) and contaminant concentrations ( 50 mg kg−1).  Conclusions: Research on biochar has grown over the years with significant focus on its properties, and how these affect biochar’s ability to immobilize organic and inorganic contaminants in soil. Few of these studies have been field-based. More studies with greater focus on field-based soil remediation are therefore required to fully understand the behavior of biochar under natural circumstances. Other recommendations are made aimed at stimulating future research in areas where significant knowledge gaps exist

    Signalling mechanisms mediating Zn2+-induced TRPM2 channel activation and death cell in microglial cells

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    Excessive Zn2+ causes brain damage via promoting ROS generation. Here we investigated the role of ROS-sensitive TRPM2 channel in H2O2/Zn2+-induced Ca2+ signalling and cell death in microglial cells. H2O2/Zn2+ induced concentration-dependent increases in cytosolic Ca2+ concentration ([Ca2+]c), which was inhibited by PJ34, a PARP inhibitor, and abolished by TRPM2 knockout (TRPM2-KO). Pathological concentrations of H2O2/Zn2+ induced substantial cell death that was inhibited by PJ34 and DPQ, PARP inhibitors, 2-APB, a TRPM2 channel inhibitor, and prevented by TRPM2-KO. Further analysis indicate that Zn2+ induced ROS production, PARP-1 stimulation, increase in the [Ca2+]c and cell death, which were suppressed by chelerythrine, a protein kinase C inhibitor, DPI, a NADPH-dependent oxidase (NOX) inhibitor, GKT137831, a NOX1/4 inhibitor, and Phox-I2, a NOX2 inhibitor. Furthermore, Zn2+-induced PARP-1 stimulation, increase in the [Ca2+]c and cell death were inhibited by PF431396, a Ca2+-sensitive PYK2 inhibitor, and U0126, a MEK/ERK inhibitor. Taken together, our study shows PKC/NOX-mediated ROS generation and PARP-1 activation as an important mechanism in Zn2+-induced TRPM2 channel activation and, TRPM2-mediated increase in the [Ca2+]c to trigger the PYK2/MEK/ERK signalling pathway as a positive feedback mechanism that amplifies the TRPM2 channel activation. Activation of these TRPM2-depenent signalling mechanisms ultimately drives Zn2+-induced Ca2+ overloading and cell death

    The Euclid Archive Processing and Data Distribution Systems: A Distributed Infrastructure for Euclid and Associated Data

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    The Euclid Archive System is an ambitious information system, which sits at the heart of the Euclid Science Ground Segment. It is a joint development between the Euclid Consortium and the ESAC Science Data Centre. It encompases both Euclid data and the large volume of associated ground based data (e.g. KiDS, DES and LSST). The Euclid Science Ground Segment consists of the Euclid Science Operations Centre and ten national Science Data Centres. The large data volumes demand that data transfer is minimized and that the processing is taken to the data. This is supported by the Euclid Archive Data Processing System and the Euclid Archive Distributed Data System. The Data Processing System consists of a central metadata repository, which contains the information necessary to process any data item and full data lineage of any data product created. The Distributed Data System provides a cloud solution with a node at each of the national Science Data Centres, which controls data storage and transfer. It supports a large number of storage types, including POSIX, iRODS, gridftp and Xrootd. No limitations are placed on the storage implemented at an individual SDC. Further more, the user of the system needs no knowledge of where data is located. Jobs will be started at the most appropriate locations, or data transferred as necessary
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