467 research outputs found

    Observations of Colloidal Gold Labelled Platelet Microtubules: High Voltage Electron Microscopy and Low Voltage-High Resolution Scanning Electron Microscopy

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    18 nm colloidal gold-antitubulin and 4 nm colloidal gold-antitubulin were used to label microtubules in adherent, fully spread platelets. Both sizes of marker effectively labelled microtubules in the partially extracted platelets. However only the 4 nm gold penetrated the dense microfilament matrix of the inner filamentous zone so that portions of microtubules within this cytoskeletal zone could be tracked. The gold marker could be visualized well with 1 MeV high voltage transmission EM and with 5 kV or greater secondary imaging or 20 kV backscattered imaging of carbon only coated samples. 1 kV secondary imaging permitted high resolution imaging of the surface of tubules and the microfilaments with their respective associated material. Individual gold-antibody complexes were difficult to identify by shape alone due to the tendency of the antibody coats to blend together when in very close approximation and due to the presence of other molecules or molecular aggregates similar in size to the gold-antibody labels. Microtubules were seen to wind in and out of the inner and outer filamentous zones as they encircled the granulomere. Some tubules were seen to dead end at the peripheral web. Numerous smaller microtubule loops were present principally in the outer filamentous zone and tubules could be followed as they went from the outer filamentous zone through the inner filamentous zone and into the granulomere

    Ecological Effects of Fear: How Spatiotemporal Heterogeneity in Predation Risk Influences Mule Deer Access to Forage in a Sky‐Island System

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    Forage availability and predation risk interact to affect habitat use of ungulates across many biomes. Within sky‐island habitats of the Mojave Desert, increased availability of diverse forage and cover may provide ungulates with unique opportunities to extend nutrient uptake and/or to mitigate predation risk. We addressed whether habitat use and foraging patterns of female mule deer (Odocoileus hemionus) responded to normalized difference vegetation index (NDVI), NDVI rate of change (green‐up), or the occurrence of cougars (Puma concolor). Female mule deer used available green‐up primarily in spring, although growing vegetation was available during other seasons. Mule deer and cougar shared similar habitat all year, and our models indicated cougars had a consistent, negative effect on mule deer access to growing vegetation, particularly in summer when cougar occurrence became concentrated at higher elevations. A seemingly late parturition date coincided with diminishing NDVI during the lactation period. Sky‐island populations, rarely studied, provide the opportunity to determine how mule deer respond to growing foliage along steep elevation and vegetation gradients when trapped with their predators and seasonally limited by aridity. Our findings indicate that fear of predation may restrict access to the forage resources found in sky islands

    Mutations in KDSR Cause Recessive Progressive Symmetric Erythrokeratoderma

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    Supplemental Data Supplemental Data include five figures and three tables and can be found with this article online at http://dx.doi.org/10.1016/j.ajhg.2017.05.003. Supplemental Data Document S1. Figures S1–S5 and Tables S1–S3 Download Document S2. Article plus Supplemental Data Download Web Resources 1000 Genomes, http://www.internationalgenome.org/ ANNOVAR, http://annovar.openbioinformatics.org/en/latest/ BWA-MEM, http://bio-bwa.sourceforge.net/index.shtml Database of Genomic Variants, http://dgv.tcag.ca/dgv/app/home dbSNP, https://www.ncbi.nlm.nih.gov/projects/SNP/ Exome Aggregation Consortium (ExAC) Browser, http://exac.broadinstitute.org/ ExonPrimer, https://ihg.helmholtz-muenchen.de/ihg/ExonPrimer.html GenBank, https://www.ncbi.nlm.nih.gov/genbank/ Genome Analysis Toolkit (GATK), https://software.broadinstitute.org/gatk/ Integrative Genomics Viewer (IGV), http://software.broadinstitute.org/software/igv/ OMIM, https://www.omim.org/ SNPmasker, http://bioinfo.ebc.ee/snpmasker/ UCSC Genome Browser, https://genome.ucsc.edu/index.html Variant Effect Predictor, http://useast.ensembl.org/info/docs/tools/vep/index.html The discovery of new genetic determinants of inherited skin disorders has been instrumental to the understanding of epidermal function, differentiation, and renewal. Here, we show that mutations in KDSR (3-ketodihydrosphingosine reductase), encoding an enzyme in the ceramide synthesis pathway, lead to a previously undescribed recessive Mendelian disorder in the progressive symmetric erythrokeratoderma spectrum. This disorder is characterized by severe lesions of thick scaly skin on the face and genitals and thickened, red, and scaly skin on the hands and feet. Although exome sequencing revealed several of the KDSR mutations, we employed genome sequencing to discover a pathogenic 346 kb inversion in multiple probands, and cDNA sequencing and a splicing assay established that two mutations, including a recurrent silent third base change, cause exon skipping. Immunohistochemistry and yeast complementation studies demonstrated that the mutations cause defects in KDSR function. Systemic isotretinoin therapy has achieved nearly complete resolution in the two probands in whom it has been applied, consistent with the effects of retinoic acid on alternative pathways for ceramide generation

    What is the importance of climate model bias when projecting the impacts of climate change on land surface processes?

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    Regional climate change impact (CCI) studies have widely involved downscaling and bias correcting (BC) global climate model (GCM)-projected climate for driving land surface models. However, BC may cause uncertainties in projecting hydrologic and biogeochemical responses to future climate due to the impaired spatiotemporal covariance of climate variables and a breakdown of physical conservation principles. Here we quantify the impact of BC on simulated climate-driven changes in water variables (evapotranspiration (ET), runoff, snow water equivalent (SWE), and water demand for irrigation), crop yield, biogenic volatile organic compounds (BVOC), nitric oxide (NO) emissions, and dissolved inorganic nitrogen (DIN) export over the Pacific Northwest (PNW) region. We also quantify the impacts on net primary production (NPP) over a small watershed in the region (HJ-Andrews). Simulation results from the coupled ECHAM5–MPI-OM model with A1B emission scenario were first dynamically downscaled to 12 km resolution with the WRF model. Then a quantile-mapping-based statistical downscaling model was used to downscale them into 1/16° resolution daily climate data over historical and future periods. Two climate data series were generated, with bias correction (BC) and without bias correction (NBC). Impact models were then applied to estimate hydrologic and biogeochemical responses to both BC and NBC meteorological data sets. These impact models include a macroscale hydrologic model (VIC), a coupled cropping system model (VIC-CropSyst), an ecohydrological model (RHESSys), a biogenic emissions model (MEGAN), and a nutrient export model (Global-NEWS). Results demonstrate that the BC and NBC climate data provide consistent estimates of the climate-driven changes in water fluxes (ET, runoff, and water demand), VOCs (isoprene and monoterpenes) and NO emissions, mean crop yield, and river DIN export over the PNW domain. However, significant differences rise from projected SWE, crop yield from dry lands, and HJ-Andrews's ET between BC and NBC data. Even though BC post-processing has no significant impacts on most of the studied variables when taking PNW as a whole, their effects have large spatial variations and some local areas are substantially influenced. In addition, there are months during which BC and NBC post-processing produces significant differences in projected changes, such as summer runoff. Factor-controlled simulations indicate that BC post-processing of precipitation and temperature both substantially contribute to these differences at regional scales. We conclude that there are trade-offs between using BC climate data for offline CCI studies versus directly modeled climate data. These trade-offs should be considered when designing integrated modeling frameworks for specific applications; for example, BC may be more important when considering impacts on reservoir operations in mountainous watersheds than when investigating impacts on biogenic emissions and air quality, for which VOCs are a primary indicator

    Mechanical Activation of Al-Oxyhydroxide Minerals – Physicochemical Changes, Reactivity and Relevance to Bayer Process

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    Overview of our research on ‘structure and reactivity’ of gibbsite and boehmite under varied conditions of mechanical activation, e.g. milling energy and presence of a second phase is presented. Bulk and surface changes induced in the solids by milling are characterized in terms of morphology, particle size distribution, specific surface area and nature of porosity, crystallite size and zeta potential. Results on enhanced amorphisation of gibbsite in presence of a second phase (quartz, hematite etc), changes in zeta potential of gibbsite due to loss of texture during milling and anomalous decrease in surface area of boehmite during milling are reported. Reactivity of the activated solids in sodium hydroxide and variation in thermal transformation temperatures is correlated with physicochemical characteristics of the samples and plausible explanation for the observed correlations presented. Significance of the results with specific reference to bauxite and alumina processing in Bayer process is highlighted

    Lipid nanoparticle-mediated hit-and-run approaches yield efficient and safe in situ gene editing in human skin

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    Despite exciting advances in gene editing, the efficient delivery of genetic tools to extrahepatic tissues remains challenging. This holds particularly true for the skin, which poses a highly restrictive delivery barrier. In this study, we ran a head-to-head comparison between Cas9 mRNA or ribonucleoprotein (RNP)-loaded lipid nanoparticles (LNPs) to deliver gene editing tools into epidermal layers of human skin, aiming for in situ gene editing. We observed distinct LNP composition and cell-specific effects such as an extended presence of RNP in slow-cycling epithelial cells for up to 72 h. While obtaining similar gene editing rates using Cas9 RNP and mRNA with MC3-based LNPs (10-16%), mRNA-loaded LNPs proved to be more cytotoxic. Interestingly, ionizable lipids with a pK(a) ∌ 7.1 yielded superior gene editing rates (55%-72%) in two-dimensional (2D) epithelial cells while no single guide RNA-dependent off-target effects were detectable. Unexpectedly, these high 2D editing efficacies did not translate to actual skin tissue where overall gene editing rates between 5%-12% were achieved after a single application and irrespective of the LNP composition. Finally, we successfully base-corrected a disease-causing mutation with an efficacy of ∌5% in autosomal recessive congenital ichthyosis patient cells, showcasing the potential of this strategy for the treatment of monogenic skin diseases. Taken together, this study demonstrates the feasibility of an in situ correction of disease-causing mutations in the skin that could provide effective treatment and potentially even a cure for rare, monogenic, and common skin diseases

    The Pediatric Obsessive-Compulsive Disorder Treatment Study II: rationale, design and methods

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    This paper presents the rationale, design, and methods of the Pediatric Obsessive-Compulsive Disorder Treatment Study II (POTS II), which investigates two different cognitive-behavior therapy (CBT) augmentation approaches in children and adolescents who have experienced a partial response to pharmacotherapy with a serotonin reuptake inhibitor for OCD. The two CBT approaches test a "single doctor" versus "dual doctor" model of service delivery. A specific goal was to develop and test an easily disseminated protocol whereby child psychiatrists would provide instructions in core CBT procedures recommended for pediatric OCD (e.g., hierarchy development, in vivo exposure homework) during routine medical management of OCD (I-CBT). The conventional "dual doctor" CBT protocol consists of 14 visits over 12 weeks involving: (1) psychoeducation, (2), cognitive training, (3) mapping OCD, and (4) exposure with response prevention (EX/RP). I-CBT is a 7-session version of CBT that does not include imaginal exposure or therapist-assisted EX/RP. In this study, we compared 12 weeks of medication management (MM) provided by a study psychiatrist (MM only) with two types of CBT augmentation: (1) the dual doctor model (MM+CBT); and (2) the single doctor model (MM+I-CBT). The design balanced elements of an efficacy study (e.g., random assignment, independent ratings) with effectiveness research aims (e.g., differences in specific SRI medications, dosages, treatment providers). The study is wrapping up recruitment of 140 youth ages 7–17 with a primary diagnosis of OCD. Independent evaluators (IEs) rated participants at weeks 0,4,8, and 12 during acute treatment and at 3,6, and 12 month follow-up visits

    Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

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