714 research outputs found

    Deformation of continental crust along a transform boundary, Coast Mountains, British Columbia

    Get PDF
    New structural, paleomagnetic, and apatite (U-Th)/He results from the continental margin inboard of the Queen Charlotte fault (~54°N) delineate patterns of brittle faulting linked to transform development since ~50 Ma. In the core of the orogen, ~250 km from the transform, north striking, dip-slip brittle faults and vertical axis rotation of large crustal domains occurred after ~50 Ma and before intrusion of mafic dikes at 20 Ma. By 20 Ma, dextral faulting was active in the core of the orogen, but extension had migrated toward the transform, continuing there until <9 Ma. Local tilting in the core of the orogen is associated with glacially driven, post-4 Ma exhumation. Integration with previous results shows that post-50 Ma dextral and normal faulting affected a region ~250 km inboard of the transform and ~300 km along strike. Initially widespread, the zone of active extension narrowed and migrated toward the transform ~25 Ma after initiation of the transform, while dextral faulting continued throughout the region. Differential amounts of post-50 Ma extension created oroclines at the southern and northern boundaries of the deformed region. This region approximately corresponds to continental crust that was highly extended just prior to transform initiation. Variation in Neogene crustal tilts weakens interpretations relying on uniform tilting to explain anomalous paleomagnetic inclinations of mid-Cretaceous plutons. Similarities to the Gulf of California suggest that development of a transform in continental crust is aided by previous crustal extension and that initially widespread extension narrows and moves toward the transform as the margin develops

    The Fatigue Associated with Depression Questionnaire (FAsD): responsiveness and responder definition

    Get PDF
    PURPOSE: The Fatigue Associated with Depression Questionnaire (FAsD) was developed to assess fatigue and its impact among patients with depression. The purpose of this study was to examine the questionnaire’s responsiveness to change and identify a responder definition for interpretation of treatment-related changes. METHODS: Data were collected at baseline and at 6 weeks from patients with depression starting treatment with a new antidepressant. RESULTS: Of the 96 participants, 55.2% were women, with a mean age of 43.4 years. The total score and both subscales demonstrated statistically significant change with moderate to large effect sizes (absolute values ≥0.76). FAsD change scores were significantly correlated with change on the Brief Fatigue Inventory (r ≥ 0.73; p < 0.001). FAsD mean change scores discriminated among patient subgroups differing by degree of improvement in patient- and clinician-reported fatigue and depression. Responder definition for the two subscales and total score (0.67, 0.57, 0.62) was estimated primarily based on mean change among patients who reported a small but important improvement in fatigue. DISCUSSION: The FAsD was responsive to change, and the responder definition may be used when interpreting treatment-related change. Results add to previous findings suggesting the FAsD is a useful measure of fatigue among patients with depression

    Occupational and environmental hazard assessments for the isolation, purification and toxicity testing of cyanobacterial toxins

    Get PDF
    Cyanobacteria can produce groups of structurally and functionally unrelated but highly potent toxins. Cyanotoxins are used in multiple research endeavours, either for direct investigation of their toxicologic properties, or as functional analogues for various biochemical and physiological processes. This paper presents occupational safety guidelines and recommendations for personnel working in field, laboratory or industrial settings to produce and use purified cyanotoxins and toxic cyanobacteria, from bulk harvesting of bloom material, mass culture of laboratory isolates, through routine extraction, isolation and purification. Oral, inhalational, dermal and parenteral routes are all potential occupational exposure pathways during the various stages of cyanotoxin production and application. Investigation of toxicologic or pharmacologic properties using in vivo models may present specific risks if radiolabelled cyanotoxins are employed, and the potential for occupational exposure via the dermal route is heightened with the use of organic solvents as vehicles. Inter- and intra-national transport of living cyanobacteria for research purposes risks establishing feral microalgal populations, so disinfection of culture equipment and destruction of cells by autoclaving, incineration and/or chlorination is recommended in order to prevent viable cyanobacteria from escaping research or production facilities

    Why do models overestimate surface ozone in the Southeast United States

    Get PDF
    Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx  ≡  NO + NO2) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC4RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25°  ×  0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NOx from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC4RS observations of NOx and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO2 columns. Our results indicate that NEI NOx emissions from mobile and industrial sources must be reduced by 30–60 %, dependent on the assumption of the contribution by soil NOx emissions. Upper-tropospheric NO2 from lightning makes a large contribution to satellite observations of tropospheric NO2 that must be accounted for when using these data to estimate surface NOx emissions. We find that only half of isoprene oxidation proceeds by the high-NOx pathway to produce ozone; this fraction is only moderately sensitive to changes in NOx emissions because isoprene and NOx emissions are spatially segregated. GEOS-Chem with reduced NOx emissions provides an unbiased simulation of ozone observations from the aircraft and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NOx oxidation products. However, the model is still biased high by 6 ± 14 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone decrease from 1.5 km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer

    Natural resistance to Potato virus Y in <i>Solanum tuberosum</i> Group Phureja

    Get PDF
    This work was supported by funding from the Scottish Government’s Rural and Environmental Science and Analytical Services (RESAS) Division.A new source of genetic resistance derived from Solanum tuberosum Group Phureja against Potato virus Y (PVY) was identified and genetically characterised in three diploid biparental potato populations. Segregation data for two populations (05H1 and 08H1) suggested the presence of a single dominant gene for resistance to PVY which, following DaRT analysis of the 08H1 cross, was mapped to chromosome 9. More detailed genetic analysis of resistance utilised a well-characterised SNP-linkage map for the 06H1 population, together with newly generated marker data. In these plants, which have both S. tuberosum Group Phureja and S. tuberosum Group Tuberosum in their pedigree, the resistance was shown to map to chromosome 9 at a locus not previously associated with PVY resistance, although there is evidence for at least one other genetic factor controlling PVY infection. The resistance factor location on chromosome 9 (named as Ry(o)phu) suggests a potential role of NB-LRR genes in this resistance. Phenotypic analysis using a GUS-tagged virus revealed that a small amount of PVY replication occurred in occasional groups of epidermal cells in inoculated leaves of resistant plants, without inducing any visible hypersensitive response. However, the virus did not enter the vascular system and systemic spread was completely prevented.Publisher PDFPeer reviewe

    Three dimensional optic tissue culture and process

    Get PDF
    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix

    Prepregnancy body mass index, gestational weight gain, and elevated depressive symptoms in a Hispanic cohort.

    Get PDF
    Our objective was to assess the associations among prepregnancy Body Mass Index (BMI), gestational weight gain (GWG), and elevated depressive symptoms across pregnancy

    The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of synbiotics

    Get PDF
    In May 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel of nutritionists, physiologists and microbiologists to review the definition and scope of synbiotics. The panel updated the definition of a synbiotic to “a mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confers a health benefit on the host”. The panel concluded that defining synbiotics as simply a mixture of probiotics and prebiotics could suppress the innovation of synbiotics that are designed to function cooperatively. Requiring that each component must meet the evidence and dose requirements for probiotics and prebiotics individually could also present an obstacle. Rather, the panel clarified that a complementary synbiotic, which has not been designed so that its component parts function cooperatively, must be composed of a probiotic plus a prebiotic, whereas a synergistic synbiotic does not need to be so. A synergistic synbiotic is a synbiotic for which the substrate is designed to be selectively utilized by the co-administered microorganisms. This Consensus Statement further explores the levels of evidence (existing and required), safety, effects upon targets and implications for stakeholders of the synbiotic concept
    corecore