268 research outputs found

    Soil microbial communities in diverse agroecosystems exposed to the herbicide glyphosate

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    © 2020 American Society for Microbiology. Despite glyphosate\u27s wide use for weed control in agriculture, questions remain about the herbicide\u27s effect on soil microbial communities. The existing scientific literature contains conflicting results, from no observable effect of glyphosate to the enrichment of agricultural pathogens such as Fusarium spp. We conducted a comprehensive field-based study to compare the microbial communities on the roots of plants that received a foliar application of glyphosate to adjacent plants that did not. The 2-year study was conducted in Beltsville, MD, and Stoneville, MS, with corn and soybean crops grown in a variety of organic and conventional farming systems. By sequencing environmental metabarcode amplicons, the prokaryotic and fungal communities were described, along with chemical and physical properties of the soil. Sections of corn and soybean roots were plated to screen for the presence of plant pathogens. Geography, farming system, and season were significant factors determining the composition of fungal and prokaryotic communities. Plots treated with glyphosate did not differ from untreated plots in overall microbial community composition after controlling for other factors. We did not detect an effect of glyphosate treatment on the relative abundance of organisms such as Fusarium spp

    Kinder mit KunstherzunterstĂŒtzungssystemen im hĂ€uslichen Bereich: Ausbildungskonzept und Notfallalgorithmus fĂŒr RettungskrĂ€fte

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    Zusammenfassung: Einleitung: Miniaturisierte HerzunterstĂŒtzungspumpen, sog. Kunstherzsysteme oder "ventricular assist devices" (VADs) bieten die Möglichkeit, diese Systeme im Kindesalter anzuwenden. Durch die lange Wartezeit auf ein geeignetes Spenderorgan sollte bei Kindern, unterstĂŒtzt mit einem intrakorporealen VAD, die Entlassung nach Hause angestrebt werden. Schwerpunkte vor einem Spitalaustritt sind neben der adĂ€quaten Schulung und AufklĂ€rung des Patienten und deren Familie auch ein Ausbildungs- und Schulungskonzept fĂŒr die lokalen RettungskrĂ€fte und die Betreuungspersonen vor Ort. Methoden: Es wird ein auf die prĂ€klinische Versorgung abgestimmter Notfallalgorithmus fĂŒr die Erstversorgung von VAD-Patienten vorgestellt sowie das gemeinsam erarbeitete Ausbildungskonzept der lokalen RettungskrĂ€fte und des Kinderspitals ZĂŒrich. Schwerpunkte des Schulungsprogramms sind neben der theoretischen EinfĂŒhrung praktische Workshops, "cardiac arrest simulation training" (CAST) sowie die Erstellung eines genau definierten Alarmierungsplans unter Einbezug der lokalen Ă€rztlichen Organisationsstrukturen und der Spezialisten des Kinderspitals. Schlussfolgerung: Die Besonderheiten bei der Versorgung von Kindern am VAD werden vorgestellt und diskutier

    The Role of Biomethylation in Toxicity and Carcinogenicity of Arsenic: A Research Update

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    Recent research of the metabolism and biological effects of arsenic has profoundly changed our understanding of the role of metabolism in modulation of toxicity and carcinogenicity of this metalloid. Historically, the enzymatic conversion of inorganic arsenic to mono- and dimethylated species has been considered a major mechanism for detoxification of inorganic arsenic. However, compelling experimental evidence obtained from several laboratories suggests that biomethylation, particularly the production of methylated metabolites that contain trivalent arsenic, is a process that activates arsenic as a toxin and a carcinogen. This article summarizes this evidence and provides new data on a) the toxicity of methylated trivalent arsenicals in mammalian cells, b) the effects of methylated trivalent arsenicals on gene transcription, and c) the mechanisms involved in arsenic methylation in animal and human tissues

    Opposing effects of Elk-1 multisite phosphorylation shape its response to ERK activation.

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    Multisite phosphorylation regulates many transcription factors, including the serum response factor partner Elk-1. Phosphorylation of the transcriptional activation domain (TAD) of Elk-1 by the protein kinase ERK at multiple sites potentiates recruitment of the Mediator transcriptional coactivator complex and transcriptional activation, but the roles of individual phosphorylation events had remained unclear. Using time-resolved nuclear magnetic resonance spectroscopy, we found that ERK2 phosphorylation proceeds at markedly different rates at eight TAD sites in vitro, which we classified as fast, intermediate, and slow. Mutagenesis experiments showed that phosphorylation of fast and intermediate sites promoted Mediator interaction and transcriptional activation, whereas modification of slow sites counteracted both functions, thereby limiting Elk-1 output. Progressive Elk-1 phosphorylation thus ensures a self-limiting response to ERK activation, which occurs independently of antagonizing phosphatase activity

    Characterization and social correlates of fecal testosterone and cortisol excretion in wild male Saguinus mystax

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    Reproductive success in male primates can be influenced by testosterone (T) and cortisol (C). We examined them in wild Saguinus mystax via fecal hormone analysis. Firstly, we wanted to characterize male hormonal status over the course of the year. Further we tested the influence of the reproductive status of the breeding female, social instability, and intergroup encounter rates on T levels, comparing the results with predictions of the challenge hypothesis (Wingfield et al., 1990). We also tested for interindividual differences in hormonal levels, possibly related to social or breeding status. We collected data during a 12-mo study on 2 groups of moustached tamarins at the Estación Biológica Quebrada Blanco in northeastern Peru. We found fairly similar T and C levels over the course of the year for all males. Yet an elevation of T shortly after the birth of infants, during the phase of ovarian inactivity of the group’s breeding female, was evident. Hormonal levels were not significantly elevated during a phase of social instability, did not correlate with intergroup encounter rates, and did not differ between breeding and nonbreeding males. Our results confirm the challenge hypothesis (Wingfield et al., 1990). The data suggest that reproductive competition inmoustached tamarins is not based on endocrinological, but instead on behavioral mechanisms, possibly combined with sperm competition.Deutsche Forschungsgemeinschaft (HE 1870/10-1,2

    Biodiversity Loss and the Taxonomic Bottleneck: Emerging Biodiversity Science

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    Human domination of the Earth has resulted in dramatic changes to global and local patterns of biodiversity. Biodiversity is critical to human sustainability because it drives the ecosystem services that provide the core of our life-support system. As we, the human species, are the primary factor leading to the decline in biodiversity, we need detailed information about the biodiversity and species composition of specific locations in order to understand how different species contribute to ecosystem services and how humans can sustainably conserve and manage biodiversity. Taxonomy and ecology, two fundamental sciences that generate the knowledge about biodiversity, are associated with a number of limitations that prevent them from providing the information needed to fully understand the relevance of biodiversity in its entirety for human sustainability: (1) biodiversity conservation strategies that tend to be overly focused on research and policy on a global scale with little impact on local biodiversity; (2) the small knowledge base of extant global biodiversity; (3) a lack of much-needed site-specific data on the species composition of communities in human-dominated landscapes, which hinders ecosystem management and biodiversity conservation; (4) biodiversity studies with a lack of taxonomic precision; (5) a lack of taxonomic expertise and trained taxonomists; (6) a taxonomic bottleneck in biodiversity inventory and assessment; and (7) neglect of taxonomic resources and a lack of taxonomic service infrastructure for biodiversity science. These limitations are directly related to contemporary trends in research, conservation strategies, environmental stewardship, environmental education, sustainable development, and local site-specific conservation. Today’s biological knowledge is built on the known global biodiversity, which represents barely 20% of what is currently extant (commonly accepted estimate of 10 million species) on planet Earth. Much remains unexplored and unknown, particularly in hotspots regions of Africa, South Eastern Asia, and South and Central America, including many developing or underdeveloped countries, where localized biodiversity is scarcely studied or described. ‘‘Backyard biodiversity’’, defined as local biodiversity near human habitation, refers to the natural resources and capital for ecosystem services at the grassroots level, which urgently needs to be explored, documented, and conserved as it is the backbone of sustainable economic development in these countries. Beginning with early identification and documentation of local flora and fauna, taxonomy has documented global biodiversity and natural history based on the collection of ‘‘backyard biodiversity’’ specimens worldwide. However, this branch of science suffered a continuous decline in the latter half of the twentieth century, and has now reached a point of potential demise. At present there are very few professional taxonomists and trained local parataxonomists worldwide, while the need for, and demands on, taxonomic services by conservation and resource management communities are rapidly increasing. Systematic collections, the material basis of biodiversity information, have been neglected and abandoned, particularly at institutions of higher learning. Considering the rapid increase in the human population and urbanization, human sustainability requires new conceptual and practical approaches to refocusing and energizing the study of the biodiversity that is the core of natural resources for sustainable development and biotic capital for sustaining our life-support system. In this paper we aim to document and extrapolate the essence of biodiversity, discuss the state and nature of taxonomic demise, the trends of recent biodiversity studies, and suggest reasonable approaches to a biodiversity science to facilitate the expansion of global biodiversity knowledge and to create useful data on backyard biodiversity worldwide towards human sustainability

    Induction of JNK and c-Abl signalling by cisplatin and oxaliplatin in mismatch repair-proficient and -deficient cells

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    Loss of DNA mismatch repair has been observed in a variety of human cancers. Recent studies have shown that loss of DNA mismatch repair results in resistance to cisplatin but not oxaliplatin, suggesting that the mismatch repair proteins serve as a detector for cisplatin but not oxaliplatin adducts. To identify the signal transduction pathways with which the detector communicates, we investigated the effect of loss of DNA mismatch repair on activation of known damage-responsive pathways, and recently reported that cisplatin differentially activates c-Jun NH2-terminal kinase (JNK) and c-Abl in repair-proficient vs.-deficient cells. In the current study, we directly compared differential activation of these pathways by cisplatin vs. oxaliplatin. The results confirm that cisplatin activates JNK kinase 5.7 ± 1.5 (s.d.)-fold more efficiently in DNA mismatch repair-proficient than repair-deficient cells, and that the c-Abl response to cisplatin is completely absent in DNA mismatch repair-deficient cells. In contrast, there was no detectable activation of the JNK or c-Abl kinases in DNA mismatch repair-proficient or -deficient cells exposed to oxaliplatin. The present study demonstrates that, despite the similarity of the adducts produced by cisplatin and oxaliplatin, they appear to be recognized by different detectors. The DNA mismatch repair system plays an important part in the recognition of cisplatin adducts, and activation of both the JNK and c-Abl kinases in response to cisplatin damage is dependent on the detector function of the DNA mismatch repair proteins. In contrast, this detector does not respond to oxaliplatin adducts. © 1999 Cancer Research Campaig

    Soil and Cultivar Type Shape the Bacterial Community in the Potato Rhizosphere

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    The rhizospheres of five different potato cultivars (including a genetically modified cultivar) obtained from a loamy sand soil and two from a sandy peat soil, next to corresponding bulk soils, were studied with respect to their community structures and potential function. For the former analyses, we performed bacterial 16S ribosomal RNA gene-based PCR denaturing gradient gel electrophoresis (PCR-DGGE) on the basis of soil DNA; for the latter, we extracted microbial communities and subjected these to analyses in phenotype arrays (PM1, PM2, and PM4, Biolog), with a focus on the use of different carbon, sulfur and phosphorus sources. In addition, we performed bacterial PCR-DGGE on selected wells to assess the structures of these substrate-responsive communities. Effects of soil type, the rhizosphere, and cultivar on the microbial community structures were clearly observed. Soil type was the most determinative parameter shaping the functional communities, whereas the rhizosphere and cultivar type also exerted an influence. However, no genetically modified plant effect was observed. The effects were imminent based on general community analysis and also single-compound analysis. Utilization of some of the carbon and sulfur sources was specific per cultivar, and different microbial communities were found as defined by cultivar. Thus, both soil and cultivar type shaped the potato root-associated bacterial communities that were responsive to some of the substrates in phenotype arrays

    A plesiosaur containing an ichthyosaur embryo as stomach contents from the Sundance Formation of the Bighorn Basin, Wyoming

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    Herein we report the discovery of an ichthyosaur embryo from the Upper Member of the Sundance Formation (Oxfordian) of the Bighorn Basin, Wyoming. The specimen is the first known ichthyosaur embryo from the Upper Jurassic, and is the first Jurassic ichthyosaur embryo from North America. The embryo was discovered in close association with the abdomen of an articulated partial plesiosaur skeleton, and several lines of evidence support the interpretation of the embryo as plesiosaur stomach contents. The small size and extremely poor ossification of the embryo indicate that the animal was probably not a neonate. Although the taxonomic affinities of the fossil are unknown, the large ichthyosaurian (sensu stricto) Opthalmosaurus natans is the only known ichthyosaur from the Sundance Formation, and the embryo may belong to that taxon
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