11,962 research outputs found

    Multiple QTL for horticultural traits and quantitative resistance to Phytophthora infestans linked on Solanum habrochaites chromosome 11.

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    Previously, a Phytophthora infestans resistance QTL from Solanum habrochaites chromosome 11 was introgressed into cultivated tomato (S. lycopersicum). Fine mapping of this resistance QTL using near-isogenic lines (NILs) revealed some co-located QTL with undesirable effects on plant size, canopy density, and fruit size traits. Subsequently, higher-resolution mapping with sub-NILs detected multiple P. infestans resistance QTL within this 9.4-cM region of chromosome 11. In our present study, these same sub-NILs were also evaluated for 17 horticultural traits, including yield, maturity, fruit size and shape, fruit quality, and plant architecture traits in replicated field experiments over 2 years. The horticultural trait QTL originally detected by fine mapping each fractionated into two or more QTL at higher resolution. A total of 34 QTL were detected across all traits, with 14% exhibiting significant QTL × environment interactions (QTL × E). QTL for many traits were co-located, suggesting either pleiotropic effects or tight linkage among genes controlling these traits. Recombination in the pericentromeric region of the introgression between markers TG147 and At4g10050 was suppressed to approximately 29.7 Mbp per cM, relative to the genomewide average of 750 kbp per cM. The genetic architecture of many of the horticultural and P. infestans resistance traits that mapped within this chromosome 11 S. habrochaites region is complex. Complicating factors included fractionation of QTL, pleiotropy or tight linkage of QTL for multiple traits, pericentromeric chromosomal location(s), and/or QTL × E. High-resolution mapping of QTL in this region would be needed to determine which specific target QTL could be useful in breeding cultivated tomato

    Negations in syllogistic reasoning: Evidence for a heuristic–analytic conflict

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    An experiment utilizing response time measures was conducted to test dominant processing strategies in syllogistic reasoning with the expanded quantifier set proposed by Roberts (2005). Through adding negations to existing quantifiers it is possible to change problem surface features without altering logical validity. Biases based on surface features such as atmosphere, matching, and the probability heuristics model (PHM; Chater & Oaksford, 1999; Wetherick & Gilhooly, 1995) would not be expected to show variance in response latencies, but participant responses should be highly sensitive to changes in the surface features of the quantifiers. In contrast, according to analytic accounts such as mental models theory and mental logic (e.g., Johnson-Laird & Byrne, 1991; Rips, 1994) participants should exhibit increased response times for negated premises, but not be overly impacted upon by the surface features of the conclusion. Data indicated that the dominant response strategy was based on a matching heuristic, but also provided evidence of a resource-demanding analytic procedure for dealing with double negatives. The authors propose that dual-process theories offer a stronger account of these data whereby participants employ competing heuristic and analytic strategies and fall back on a heuristic response when analytic processing fails

    A History of Change and Reorganization: The Pelagic Longline Fishery in Gouyave, Grenada

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    This paper traces the history of the pelagic surface longline fishery in Gouyave, Grenada, noting 4 major periods of change from pre-1985 to 2004. Reconstructed from document reviews, newspaper articles, oral history, and key informant interviews 1) the pre-1985 period was the time when the longline was introduced and popularized by the Cubans, 2) the period of institutionalization and technology development (1986-1990) corresponded to the strengthening of institutional arrangements and the initial improvements in technology, 3) the Coastal Fisheries Development Project (CFDP) of 1991-1999 was the period of international donor support and further technology change in longline construction, and finally 4) the 2000-2004 period marked innovation, training and fish quality control for export markets. The main point of the paper is that fisheries management is about the management of change. Fishery managers need to learn to deal, not only with technology change, but also with surprise and variability related to biophysical change (e.g., hurricanes), change in markets, and other external drivers such as international policies. Key considerations for managers to deal successfully with change include: learning from experience, capacity building, and the need to engage cooperatively with fishers and communities, the private sector, and non-governmental organizations

    How effective--and safe--are systemic steroids for acute low back pain?

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    Short courses of systemic steroids are likely safe, but they are ineffective. A single dose of intramuscular (IM) or intravenous (IV) methylprednisolone doesn't improve long-term pain scores in patients with low back pain and sciatica and produces conflicting effects on function. Oral prednisone (9-day taper) doesn't improve pain or function in patients with back pain and sciatica. A single IM dose of methylprednisolone doesn't improve pain scores or function in patients with back pain without sciatica (strength of recommendation: B, randomized controlled trials [RCTs]). No trials of corticosteroids for back pain reported an increase in adverse outcomes, but studies were small, and only short-term (1 month) follow-up data are available

    The identification of mitochondrial DNA variants in glioblastoma multiforme

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    Background: Mitochondrial DNA (mtDNA) encodes key proteins of the electron transfer chain (ETC), which produces ATP through oxidative phosphorylation (OXPHOS) and is essential for cells to perform specialised functions. Tumor-initiating cells use aerobic glycolysis, a combination of glycolysis and low levels of OXPHOS, to promote rapid cell proliferation and tumor growth. Glioblastoma multiforme (GBM) is an aggressively malignant brain tumor and mitochondria have been proposed to play a vital role in GBM tumorigenesis. Results: Using next generation sequencing and high resolution melt analysis, we identified a large number of mtDNA variants within coding and non-coding regions of GBM cell lines and predicted their disease-causing potential through in silico modeling. The frequency of variants was greatest in the D-loop and origin of light strand replication in non-coding regions. ND6 was the most susceptible coding gene to mutation whilst ND4 had the highest frequency of mutation. Both genes encode subunits of complex I of the ETC. These variants were not detected in unaffected brain samples and many have not been previously reported. Depletion of HSR-GBM1 cells to varying degrees of their mtDNA followed by transplantation into immunedeficient mice resulted in the repopulation of the same variants during tumorigenesis. Likewise, de novo variants identified in other GBM cell lines were also incorporated. Nevertheless, ND4 and ND6 were still the most affected genes. We confirmed the presence of these variants in high grade gliomas. Conclusions: These novel variants contribute to GBM by rendering the ETC. partially dysfunctional. This restricts metabolism to anaerobic glycolysis and promotes cell proliferation

    The Association Between Men’s Heath Behaviors and Interest in Workplace Health Promotion

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    © 2019 The Author(s). Background: Predictors of men’s health behaviors and interest in workplace health promotion are not well known. The aim of this study was to describe men’s interest in workplace health promotion and associated health behaviors. Method: Male employees (N = 781) at six workplaces in British Columbia, Canada, were invited to complete a survey of their health behaviors, demographics, and interest in health promotion prior to implementation of a workplace health program. Findings: A total of 227 male employees (Mage = 43.6 years; SD = 12.1) completed the survey (response rate = 29%). Regarding health behaviors, 62.1% reported 150 weekly minutes of moderate-to-vigorous physical activity (MVPA), 29.3% consumed 5+ servings of fruit/vegetables per day, 56.8% reported 7+ hours sleep/night, 14.4% smoked, and 81.3% consumed alcohol. Men spent 50% of their workday sitting, and higher body mass index (BMI), higher income, and greater hours worked were related to greater hours sitting. Age was inversely related to MVPA. Alcohol consumption was lower among men who were older, had higher income, and worked fewer hours. Most men were interested in being physically active (85%), managing stress (85%), eating healthy (89%), and cancer screening (91%). Higher stage of change for physical activity (β =.20, p =.003) and fruit/vegetable consumption (β =.18, p =.027) were related to interest in these activities. Conclusions/Application to Practice: Occupational health providers should consider worker demographics and could support interventions that target individuals with varying levels of health behaviors given the importance of meeting the needs of often sedentary workers

    Photonic-crystal slabs with a triangular lattice of triangular holes investigated using a guided-mode expansion method

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    According to a recent proposal [S. Takayama et al., Appl. Phys. Lett. 87, 061107 (2005)], the triangular lattice of triangular air holes may allow to achieve a complete photonic band gap in two-dimensional photonic crystal slabs. In this work we present a systematic theoretical study of this photonic lattice in a high-index membrane, and a comparison with the conventional triangular lattice of circular holes, by means of the guided-mode expansion method whose detailed formulation is described here. Photonic mode dispersion below and above the light line, gap maps, and intrinsic diffraction losses of quasi-guided modes are calculated for the periodic lattice as well as for line- and point-defects defined therein. The main results are summarized as follows: (i) the triangular lattice of triangular holes does indeed have a complete photonic band gap for the fundamental guided mode, but the useful region is generally limited by the presence of second-order waveguide modes; (ii) the lattice may support the usual photonic band gap for even modes (quasi-TE polarization) and several band gaps for odd modes (quasi-TM polarization), which could be tuned in order to achieve doubly-resonant frequency conversion between an even mode at the fundamental frequency and an odd mode at the second-harmonic frequency; (iii) diffraction losses of quasi-guided modes in the triangular lattices with circular and triangular holes, and in line-defect waveguides or point-defect cavities based on these geometries, are comparable. The results point to the interest of the triangular lattice of triangular holes for nonlinear optics, and show the usefulness of the guided-mode expansion method for calculating photonic band dispersion and diffraction losses, especially for higher-lying photonic modes.Comment: 16 pages, 11 figure
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