4,082 research outputs found

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    A chloride-based chemical-vapor-deposition (CVD) process has been successfully used to grow very high quality 3C-SiC epitaxial layers on on-axis α-SiC substrates. An accurate process parameters study was performed testing the effect of temperature, surface preparation, precursor ratios, nitrogen addition, and substrate polytype and polarity. The 3C layers deposited showed to be largely single-domain material of very high purity and of excellent electrical characteristics. A growth rate of up to 10 Όm/h and a low background doping enable deposition of epitaxial layers suitable for MOSFET devices

    MicroRNA-433 Dampens Glucocorticoid Receptor Signaling, Impacting Circadian Rhythm and Osteoblastic Gene Expression

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    FUNDING This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health [AR44877]; the National Institutes for Dental and Craniofacial Research [5T90DE21989]; a Grant-in-Aid award from the American Society for Bone and Mineral Research; the UConn Health Center Research Advisory council; and the Center for Molecular Medicine at UConn Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.Peer reviewedPublisher PD

    The Final Days of the Franklin Expedition: New Skeletal Evidence

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    In 1992, a previously unrecorded site of Sir John Franklin's last expedition (1845-1848) was discovered on King William Island in the central Canadian Arctic. Artifacts recovered from the site included iron and copper nails, glass, a clay pipe fragment, pieces of fabric and shoe leather, buttons, and a scatter of wood fragments, possibly representing the remains of a lifeboat or sledge. Nearly 400 human bones and bone fragments, representing a minimum of 11 men, were also found at the site. A combination of artifactual and oxygen isotope evidence indicated a European origin for at least two of these individuals. Skeletal pathology included periostitis, osteoarthritis, dental caries, abscesses, antemortem tooth loss, and periodontal disease. Mass spectroscopy and x-ray fluorescence revealed elevated lead levels consistent with previous measurements, further supporting the conclusion that lead poisoning contributed to the demise of the expedition. Cut marks on approximately one-quarter of the remains support 19th-century Inuit accounts of cannibalism among Franklin's crew.En 1992, on a découvert un site non mentionné auparavant, relié à la derniÚre expédition de sir John Franklin (1845-1848) dans l'ßle du Roi-Guillaume, située au centre de l'océan Arctique canadien. Les artefacts récupérés sur ce site comprenaient des clous en fer et en cuivre, du verre, un fragment de pipe en terre, des morceaux de tissu et de cuir de chaussure, des boutons et de multiples fragments de bois éparpillés, qui pourraient venir d'un canot de sauvetage ou d'un traßneau. On a aussi trouvé sur le site un total d'environ 400 fragments osseux ou os complets, représentant au moins 11 hommes. En se basant à la fois sur de la documentation archéologique et sur des analyses des isotopes de l'oxygÚne, on a pu attribuer une origine européenne à au moins deux de ces individus. Les lésions osseuses comprenaient périostites, ostéo-arthrite, caries dentaires, abcÚs, perte de dents précédant le décÚs et parodontolyses. La spectroscopie de masse et la fluorescence X ont révélé de forts taux de plomb correspondant aux mesures précédentes, venant ainsi appuyer la conclusion qui veut que l'empoisonnement par le plomb ait contribué à la fin de l'expédition. Des entailles sur environ un quart des ossements confirment les récits inuit du XIXe siÚcle sur le cannibalisme pratiqué par l'équipage de Franklin

    Rediscovery of the nucleolinus, a dynamic RNA-rich organelle associated with the nucleolus, spindle, and centrosomes

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    Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 107 (2010): 13718-13723, doi:10.1073/pnas.1008469107.The nucleolinus is an RNA-rich compartment, closely apposed to or embedded within the nucleolus. Discovered over 150 years ago, fewer than two dozen articles have been published on the nucleolinus, probably because complex histochemical stains are required for its visualization in the great majority of cells. The nucleolinus has been reported in invertebrate oocytes, mammalian and amphibian epithelial cells, neurons, and several transformed cell lines. A prominent nucleolinus, clearly visible with transmitted light microscopes at 10x magnification, is present in each oocyte of the surf clam, Spisula solidissima. We observed a consistent relationship between the nucleolinus and the developing meiotic apparatus following Spisula oocyte activation. Through sonication and sucrose gradient fractionation of purified oocyte nuclei, we isolated nucleolini, extracted their RNA, and prepared an in situ riboprobe (NLi-1) that is associated specifically with the nucleolinus, confirming its unique composition. Other in situ observations revealed a NLi-1 and nucleolinar association with the developing spindle and centrosomes. Laser microsurgery that targeted the nucleolinus resulted in failed meiotic cell division in parthenogenetically activated oocytes and failed mitosis in fertilized oocytes. Although the nucleolinus may be a forgotten organelle, its demonstrated role in spindle formation suggests it deserves renewed attention.This work was supported by grants from the NIH (GM088503) and NSF (MCB0843092) to MCA. J.H. acknowledges support from the National Science Foundation (IOB 05-16799) and the Directors of the MBL Embryology Cours

    Addressing electric vehicle (EV) sales and range anxiety through parking layout, policy and regulation

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    AbstractElectric Vehicles (EV) are highly beneficial due to their reliance on electricity and Climate Change response yet EV sales are lower than would be expected due to range anxiety. If a potential buyer cannot be assured of having constantly-available and compatible charging stations, they will not purchase an EV. To increase the sales of EVs through improved charger availability, this paper examines parking configurations, charger design, convenient “EV only” parking, free charging, etiquette in unplugging another’s vehicle, and legislation. Data were derived from academic publications, trade market press, conversations, personal observations, and laws. The results show that chargers are often in a lot’s corner and thus accessible only to one vehicle, EV owners leave their charged car in the space, drivers use EV spaces for parking, etiquette cards are not understood, and legislation makes it illegal to unplug another’s EV. Improvements include less convenient charger spots, an octopus charger in the middle of the parking lot, modest charging fees to foster turnover, chargers that indicate an EV is charged, education and legislation about etiquette cards, and legislation that allows an individual to unplug another’s charged EV. Improvements to charging should be implemented simultaneously to lessen range anxiety and realize the environmental benefits from reductions in gasoline consumption and mobile source air pollution

    A road map for defining Good Environmental Status in the deep-sea

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    The development of tools to assess the Good Environmental Status (GES) in the Deep Sea (DS) is one of the aspects that ATLAS WP3 is addressing. GES assessment in the DS is challenging due to 1) the lack of baseline data, 2) the remoteness of the DS ecosystems, and 3) the limitations of the sampling methods currently available. Throughout the duration of the project, ATLAS will develop a suitable approach to address GES in the DS. During the 2nd General Assembly, we will present a draft for a “road map” to address GES in the DS as well some of the aspects discussed during the 2017 ICES WG on Deep Sea Ecosystems. The temporal and spatial scale at which GES should be assessed in the deep-sea is an important aspect to be considered. Due to the data limited situation and challenges posed to monitoring, it may well be the case that GES will have to be assessed at large spatial and temporal scales when comparing the shallower waters of the European Seas. For similar reasons, the type of indicators to be used may have to be simplified and likely be based on high-level analyses related to traits, pressures/risks, and habitat /ecosystem resilience. Ultimately, the results of the combined analyses of GES descriptors might bring to a potential refining or redefinition of the GES concept for the deep-sea

    Reconciling gene expression data with regulatory network models – a stimulon-based approach for integrated metabolic and regulatory modeling of Bacillus subtilis

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    The reconstruction of genome-scale metabolic models from genome annotations has become a routine practice in Systems Biology research. The potential of metabolic models for predictive biology is widely accepted by the scientific community, but these same models still lack the capability to account for the effect of gene regulation on metabolic activity. Our focus organism, Bacillus subtilis is most commonly found in soil, being subject to a wide variety of external environmental conditions. This reinforces the importance of the regulatory mechanisms that allow the bacteria to survive and adapt to such conditions. Existing integrated metabolic regulatory models are currently available for only a small number of well-known organisms (e.g E. coli and B. subtilis). The E. coli integrated model was proposed by Covert et al in 2004 and has slowly improved over the years. Goelzer et al. introduced the B. subtilis integrated model in 2008, covering only the central metabolic pathways. Different strategies were used in the two modeling efforts. The E. coli model is defined by a set of Boolean rules (turning genes ON and OFF) accounting mostly for transcription factors, gene interactions, involved metabolites, and some external conditions such as heat shock. The B. subtilis model introduces a set of more complex rules and also incorporates sigma factor activity into the modeling abstraction. Here we propose a genome-scale model for the regulatory network of B. subtilis, using a new stimulon-based approach. A stimulon is defined as the set of genes (that can be a part of the same operon(s) and regulon(s)) that respond in the same set of stimuli. The proposed stimulon-based approach allows for the inclusion of more types of regulation in the model. This methodology also abstracts away much of the complexity of regulatory mechanisms by directly connecting the activity of genes to the presence or absence of associated stimuli, a necessity in the many cases where details of regulatory mechanisms are poorly understood. Our model integrates regulatory network data from the Goelzer et al model, in addition to other available literature data. We then reconciled our model against a large set of high-quality gene expression data (tiled microarrays for 104 different conditions). The stimulons in our model were split or extended to improve consistency with our expression data, and the stimuli in our model were adjusted to improve consistency with the conditions of our expression experiments. The reconciliation with gene expression data revealed a significant number of exact or nearly exact matches between the manually curated regulons/stimulons and pure correlation-based regulons. Our reconciliation analysis of the 2011 SubtiWiki regulon release suggested many gene candidates for regulon extension that were subsequently included in the 2013 SubtiWiki update. Our enhanced model also includes an improved coverage of a wide range of different stress conditions. We then integrated our regulatory model with the latest metabolic reconstruction for B. subtilis, the iBsu1103V2 model (Tanaka et al. 2012). We applied this integrated metabolic regulatory model to the simulation of all growth phenotype data currently available for B. subtilis, demonstrating how the addition of regulatory constraints improved consistency of model predictions with experimentally observed phenotype data. This analysis of growth phenotype data unveiled phenotypes that could only be characterized with the addition of regulatory network constraints. All tools applied in the reconstruction, simulation, and curation of our new regulatory model are now publicly available as a part of the KBase framework. These tools permit the direct simulation of gene expression data using the regulon model alone, as well as the simulation of phenotypes and growth conditions using an integrated metabolic and regulatory model. We will highlight these new tools in the context of our reconstruction and analysis of the B. subtilis regulatory model
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