2,170 research outputs found

    Recharge and source‐water insights from the Galapagos Islands using noble gases and stable isotopes

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95657/1/wrcr13236.pd

    Noble gas composition in rainwater and associated weather patterns

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    This work represents the first comprehensive noble gas study in rainwater. It was carried out in southeast Michigan. Results show that all rainwater samples are in disequilibrium with surface conditions. Two noble gas patterns are identified. The first one, associated with low‐pressure systems, presence of fog and light rainfall, displays a relative Ar enrichment together with Ne, Kr, and Xe depletion. The second one, associated with the passage of frontal systems, displays a mass‐dependent depletion pattern. Precipitation is characterized by thunderstorms, heavy rainfall, and high cloud ceiling heights. A diffusion mass‐transfer model suggests that noble gas patterns originate from ice. Complete re‐equilibration with surface conditions should occur within hours. For the first time, this study establishes a direct correlation between the noble gas composition in rainwater and weather patterns and highlights their potential to identify timing and location of recharge in shallow aquifer systems where infiltration is rapid. Key Points Noble gases in rainwater are in disequilibrium with surface conditions Rainwater noble gas patterns are associated with weather conditions Ice is the starting point of rainwater formation in southeast MichiganPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/1/FigureS12.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/2/FigureS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/3/Supplementary_Text_3_revised2_Trackchanges.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/4/FigureS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/5/FigureS8.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/6/TableS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/7/Supplementary_all.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/8/SuppText_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/9/FigureS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/10/FigureS9.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/11/TableS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/12/FigureS7.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/13/TableS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/14/SuppText_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/15/FigureS10.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/16/Supplementary_Text_3_revised2_NOhighlight.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/17/FigureS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/18/grl50610.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/19/FigureS6.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/20/FigureS11.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/21/TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/22/SuppText_4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99103/23/FigureS2.pd

    Biodegradation of Carbamazepine by the bacterial strain Labrys portucalensis F11 – metabolism and toxicologic studies

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    Background Occurrence of pharmaceuticals in the environment is a topic of concern. Most pharmaceuticals are not completely mineralized and are released on the sewage systems through excretion and by improper elimination and disposal(1). Municipal wastewater treatment plants (WWTPs) are not designed to remove them and they are released into the environment(2). They are classified as persistent microcontaminants due to their continuous release even if at low concentrations (3). Carbamazepine (CBZ) is an widely used anticonvulsant and has been suggested as a molecular marker of contamination in surface water and groundwater(4). Method Biodegradation of CBZ by the bacterial strain Labrys portucalensis F11 was tested as sole carbon and energy source (0.04 mM) and in the presence of acetate as primary carbon source. Transformation products (TPs) were detected and identified by UPLCQTOF/MS/MS. Ecotoxicologiacl effects of CBZ and the TPs resultant from biodegradation were evaluated at different trophic levels, i) zooplanckton (Dapnhia magna) and ii) plants (Lipidium sativum). The 24–48 h immobilization of D. magna bioassays were performed following the Standard Operational Procedures of Daphtoxkit FTM. The toxicity was measured as the immobilization of D. magna according to the procedures OCED Guideline 202(5). The bioassay with L. sativum evaluated the potential toxicity considering the root elongation according to OECD Guideline 208(6). Results & Conclusions Strain F11 was able to degrade 95% of initial CBZ concentration during 30 days experiment. Supplementation with acetate increased degradation to 100% in 24 days. A group of 12 TPs formed in the microbial process were identified; CBZ degradation by strain F11 proceeds mainly by oxidation, hydroxilation and cleavage of the aromatic ring. The effect of whole biodegradation products on root elongation of L. sativum was practically neglectable; however the same exhibited toxicity to D. magna. Strain Labrys portucalensis F11 proved to be able to degrade CBZ and may be potentially useful for biotechnological applications.info:eu-repo/semantics/publishedVersio

    Between local and standard varieties: horizontal and vertical convergence and divergence of dialects in Southern Spain

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    El objeto de esta comunicación es presentar los procesos de convergencia y divergencia horizontal y vertical en los dialectos innovadores del español meridional.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Noble gas signatures in Greenland : tracing glacial meltwater sources

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    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 42 (2015): 9311–9318, doi:10.1002/2015GL065778.This study represents the first comprehensive noble gas study in glacial meltwater from the Greenland Ice Sheet. It shows that most samples are in disequilibrium with surface collection conditions. A preliminary Ne and Xe analysis suggests that about half of the samples equilibrated at a temperature of ~0°C and altitudes between 1000 m and 2000 m, with a few samples pointing to lower equilibration altitudes and temperatures between 2°C and 5°C. Two samples suggest an origin as melted ice and complete lack of equilibration with surface conditions. A helium component analysis suggests that this glacial meltwater was isolated from the atmosphere prior to the 1950s, with most samples yielding residence times ≤ 420 years. Most samples represent a mixture between a dominant atmospheric component originating as precipitation and basal meltwater or groundwater, which has accumulated crustal 4He over time.University of Michigan; Packard Foundation; Department of Earth and Environmental Sciences Turner fellowship2016-05-0

    Feiras de sementes em terras indígenas brasileiras

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    No Brasil, parte da população campesina é indígena, cerca de 305 povos que vivem em 12,5% do território. Praticam, de forma geral, uma agricultura tradicional baseada em conhecimentos ancestrais. Entretanto, em muitas terras indígenas a intensificação do contato interétnico tem ocasionado uma acelerada mudança alimentar com reflexos na saúde, em perdas da agrobiodiversidade e do conhecimento tradicional associado. O povo Krahô realizou no ano de 1997, de forma pioneira, a primeira feira de sementes tradicionais do Brasil, continuando nos anos posteriores realizalas, totalizando nove Feiras. Elas motivaram diferentes povos que passaram a realizar em seus territórios estes encontro para troca de sementes e conhecimentos. São eles: Xerente (2007, 2008, 2009); Pareci (2010, 2011, 2012); Kayapo (2013), Povos Indígenas de Roraima (2012, 2013, 2014) e Xacriabá (2013). Este movimento do campesinato brasileiro indígena tem reafirmado a preocupação destes povos com a conservação das sementes tradicionais e com alternativas agroecológicas de fortalecimento da segurança alimentar e assim influenciado e contribuído para políticas como a de agroecologia e produção orgânica (PNAPO).Eje: B5 Sistemas de conocimiento (Relatos de experiencias)Facultad de Ciencias Agrarias y Forestale
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