252 research outputs found

    Oyster (Crassostrea Virginica [Gmelin, 1791]) Mortality At Prolonged Exposures To High Temperature And Low Salinity

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    Mortality of two size classes (35 mm) of eastern oysters Crassostrea virginica when exposed to combinations of low salinity (1, 2, 3, and 4) for extended periods (up to 30 days) at summer water temperatures typical of the Virginia Chesapeake Bay subestuaries was examined. A critical salinity-temperature combination of less than two at greater than 28 degrees C for more than 1 wk exposure for oyster mortality is suggested. A review of limited historical salinity-temperature tolerance data suggest selection of local populations of oysters having differing salinity tolerances. Such selection may prove critical to persistence of low-salinity populations in the Chesapeake Bay subestuaries with projected climate change

    Entry-level Occupational Therapy Students’ Beliefs about Knowledge and Knowing: Findings from Three Masters Level Programs in the US

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    One of the expected outcomes of higher education for all entry-level occupational therapy (OT) students is to develop the capacity to think critically and engage in complex clinical reasoning. Beliefs about the justification of knowledge (epistemic cognition) and the nature of knowledge (ontological cognition) underlie the ability to develop sophisticated ways of thinking. There is a scarcity of research specific to occupational therapy students in the literature related to epistemic and ontological cognition. Based on a discussion prompted during an AOTA Scholarship of Teaching and Learning (SoTL) workshop in 2014, OT faculty members from three entry-level occupational therapy programs initiated a longitudinal SoTL project designed to assess the epistemic and ontological beliefs of their respective student cohorts and compare results cross-institutionally. The Epistemic Beliefs Inventory (EBI), a modified Four-Quadrant Scale (mFQS), and 4 open-ended questions were used to assess student views at the beginning and end of a period of didactic learning in each occupational therapy program. Results suggest changes in student views may be based on the context and curriculum of the OT program in which they were enrolled. The findings associated with this SoTL project have implications for OT educators who want to help their students develop more mature views about knowledge in preparation for the metacognitive demands of clinical practice

    Development Of An Age-Frequency Distribution For Ocean Quahogs (Arctica Islandica) On Georges Bank

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    Ocean quahogs [Arctica islandica (Linnaeus, 1769)] are the longest-lived, noncolonial animal known today, with a maximum life span exceeding 500 y. Ocean quahogs are a commercially important bivalve, inhabiting the continental shelf of the North Atlantic Basin. Although considerable information exists on the growth and physiology of A. islandica, limited information is available regarding recruitment; accordingly, sustainably managing the fishery is a challenge. To investigate long-termrecruitment trends, the age of ocean quahogs fromGeorges Bank which were fully recruited to the commercial fishery (\u3e80 mm shell length) was determined by analysis of annual growth lines in the hinge plate. Ages of animals representing the fully recruited size range were used to develop an age-length key, enabling reconstruction of the population age frequency. The population age frequency showed that the Georges Bank population experienced an increase in recruitment beginning in the late 1890s. Initial settlement, documented by a few ocean quahogs that were much older, occurred much earlier, in the early 1800s. Following the late 1890s increase in recruitment, the population expanded rapidly reaching carrying capacity in 20-30 y. Recruitment was more or less continuous after this expansion, consistent with maintenance of a population at carrying capacity. Unusually large year classes were not observed, nor were significant periods of high recruitment interspersed with periods of low recruitment. The relationship of growth rate with age for the oldest clams was assessed using the time series of yearly growth increments and the resulting relationship fitted to three models (von Bertalanffy, Gompertz, and Tanaka\u27s ALOG curve). The ALOG model was clearly superior because it allows for persistent indeterminate growth at old age, rather than the asymptotic behavior of the other two and because it allows for a rapid change in growth rate at what is presumed to be maturity

    Assessing the skill of a high-resolution marine biophysical model using geostatistical analysis of mesoscale ocean chlorophyll variability from field observations and remote sensing

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    © The Author(s), 2021. This article is distributed under the terms of the Creaive Commons Attribution License. The definitive version was published in Eveleth, R., Glover, D. M., Long, M. C., Lima, I. D., Chase, A. P., & Doney, S. C. . Assessing the skill of a high-resolution marine biophysical model using geostatistical analysis of mesoscale ocean chlorophyll variability from field observations and remote sensing. Frontiers in Marine Science, 8, (2021): 612764, https://doi.org/10.3389/fmars.2021.612764.High-resolution ocean biophysical models are now routinely being conducted at basin and global-scale, opening opportunities to deepen our understanding of the mechanistic coupling of physical and biological processes at the mesoscale. Prior to using these models to test scientific questions, we need to assess their skill. While progress has been made in validating the mean field, little work has been done to evaluate skill of the simulated mesoscale variability. Here we use geostatistical 2-D variograms to quantify the magnitude and spatial scale of chlorophyll a patchiness in a 1/10th-degree eddy-resolving coupled Community Earth System Model simulation. We compare results from satellite remote sensing and ship underway observations in the North Atlantic Ocean, where there is a large seasonal phytoplankton bloom. The coefficients of variation, i.e., the arithmetic standard deviation divided by the mean, from the two observational data sets are approximately invariant across a large range of mean chlorophyll a values from oligotrophic and winter to subpolar bloom conditions. This relationship between the chlorophyll a mesoscale variability and the mean field appears to reflect an emergent property of marine biophysics, and the high-resolution simulation does poorly in capturing this skill metric, with the model underestimating observed variability under low chlorophyll a conditions such as in the subtropics.This work was supported in part by the National Aeronautics and Space Administration (NASA) as part of the North Atlantic Aerosol and Marine Ecosystems Study (NAAMES; NASA grant 80NSSC18K0018). The CESM project is supported by the National Science Foundation and the Office of Science (BER) of the United States Department of Energy. Computing resources were provided by the Climate Simulation Laboratory at NCAR’s Computational and Information Systems Laboratory (CISL), sponsored by the National Science Foundation and other agencies. This research was enabled by CISL compute and storage resources

    Phylogenetics of Flowering Plants Based on Combined Analysis of Plastid atpB and rbcL Gene Sequences

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    Following (1) the large-scale molecular phylogeny of seed plants based on plastid rbcL gene sequences (published in 1993 by Chase et al., Ann. Missouri Bot. Gard. 80:528-580) and (2) the 18S nuclear phylogeny of flowering plants (published in 1997 by Soltis et al., Ann. Missouri Bot. Gard. 84:1-49), we present a phylogenetic analysis of flowering plants based on a second plastid gene, atpB, analyzed separately and in combination with rbcL sequences for 357 taxa. Despite some discrepancies, the atpB-based phylogenetic trees were highly congruent with those derived from the analysis of rbcL and 18S rDNA, and the combination of atpB and rbcL DNA sequences (comprising ∼3000 base pairs) produced increased bootstrap support for many major sets of taxa. The angiosperms are divided into two major groups: noneudicots with inaperturate or uniaperturate pollen (monocots plus Laurales, Magnoliales, Piperales, Ceratophyllales, and Amborellaceae-Nymphaeaceae-Illiciaceae) and the eudicots with triaperturate pollen (particularly asterids and rosids). Based on rbcL alone and atpB/rbcL combined, the noneudicots (excluding Ceratophyllum) are monophyletic, whereas in the atpB trees they form a grade. Ceratophyllum is sister to the rest of angiosperms with rbcL alone and in the combined atpB/rbcL analysis, whereas with atpB alone, Amborellaceae, Nymphaeaceae, and Illiciaceae/Schisandraceae form a grade at the base of the angiosperms. The phylogenetic information at each codon position and the different types of substitutions (observed transitions and transversions in the trees vs. pairwise comparisons) were examined; taking into account their respective consistency and retention indices, we demonstrate that third-codon positions and transitions are the most useful characters in these phylogenetic reconstructions. This study further demonstrates that phylogenetic analysis of large matrices is feasibl

    Tales from the playing field: black and minority ethnic students' experiences of physical education teacher education

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    This article presents findings from recent research exploring black and minority ethnic (BME) students’ experiences of Physical Education teacher education (PETE) in England (Flintoff, 2008). Despite policy initiatives to increase the ethnic diversity of teacher education cohorts, BME students are under-represented in PETE, making up just 2.94% of the 2007/8 national cohort, the year in which this research was conducted. Drawing on in-depth interviews and questionnaires with 25 BME students in PETE, the study sought to contribute to our limited knowledge and understanding of racial and ethnic difference in PE, and to show how ‘race,’ ethnicity and gender are interwoven in individuals’ embodied, everyday experiences of learning how to teach. In the article, two narratives in the form of fictional stories are used to present the findings. I suggest that narratives can be useful for engaging with the experiences of those previously silenced or ignored within Physical Education (PE); they are also designed to provoke an emotional as well as an intellectual response in the reader. Given that teacher education is a place where we should be engaging students, emotionally and politically, to think deeply about teaching, education and social justice and their place within these, I suggest that such stories of difference might have a useful place within a critical PETE pedagogy

    Far-infrared vibrational properties of high-pressure-high-temperature C60 polymers and the C60 dimer

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    We report high-resolution far-infrared transmission measurements of the 2 + 2 cycloaddition C-60 dimer and two-dimensional rhombohedral and one-dimensional orthorhombic high-pressure high-temperature C60 polymers. In the spectral region investigated(20-650 cm(-1)), we see no low-energy interball modes, but symmetry breaking of the linked C-60 balls is evident in the complex spectrum of intramolecular modes. Experimental features suggest large splittings or frequency shifts of some IhC60-derived modes that are activated by symmetry reduction, implying that the balls are strongly distorted in these structures. We have calculated the vibrations of all three systems by first-principles quantum molecular dynamics and use them to assign the predominant IhC60 symmetries of observed modes. Pur calculations show unprecedentedly large downshifts of T-1u(2)-derived modes and extremely large splittings of other modes, both of which are consistent with the experimental spectra. For the rhombohedral and orthorhombic polymers, the T-1u(2)-derived mode that is polarized along the bonding direction is calculated to downshift below any T-1u(1)-derived modes. We also identify a previously unassigned feature near 610 cm(-1) in all three systems as a widely split or shifted mode derived from various silent IhC60 vibrations, confirming a strong perturbation model for these linked fullerene structures

    Theoretical Studies of Spectroscopy and Dynamics of Hydrated Electrons.

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    Bevacizumab for advanced cervical cancer: patient-reported outcomes of a randomised, phase 3 trial (NRG Oncology–Gynecologic Oncology Group protocol 240)

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    Background: GOG 240 was a practice-changing randomised phase 3 trial that concluded that chemotherapy plus bevacizumab for advanced cervical cancer significantly improves overall and progression-free survival, and the proportion of patients achieving an overall objective response, compared with chemotherapy alone. In this study, we aimed to analyse patient-reported outcomes in GOG 240. Methods: Eligible adult participants (aged ≥18 years) had primary stage IVB or recurrent or persistent carcinoma of the cervix with measurable disease and GOG performance status of 0-1. Participants were randomly assigned by web-based permuted block randomisation (block size 4) in a 1:1:1:1 ratio to the four treatment groups: cisplatin (50 mg/m2 intravenously on day 1 or 2 of the treatment cycle) and paclitaxel (135 mg/m2 intravenously over 24 h or 175 mg/m2 intravenously over 3 h on day 1), with or without bevacizumab (15 mg/kg intravenously on day 1 or 2), or paclitaxel (175 mg/m2 over 3 h on day 1) and topotecan (0·75 mg/m2 for 30 min on days 1-3) with or without bevacizumab (15 mg/kg intravenously on day 1). Treatment assignment was concealed at randomisation (everyone was masked to treatment assignment, achieved by the use of a computer encrypted numbering system at the National Cancer Institute) and became open-label when each patient was registered to the trial. Treatment cycles were repeated every 21 days until disease progression or unacceptable toxicity, whichever occurred first. The coprimary endpoints of the trial were overall survival and safety; the primary quality-of-life endpoint was the score on the Functional Assessment of Cancer Therapy-Cervix Trial Outcome Index (FACT-Cx TOI). For our analysis of patient-reported outcomes, participants were assessed before treatment cycles 1, 2, and 5, and at 6 and 9 months after the start of cycle 1, with the FACT-Cx TOI, items from the FACT-GOG-Neurotoxicity subscale, and a worst pain item from the Brief Pain Inventory. All patients who completed baseline quality-of-life assessments and at least one further follow-up assessment were evaluable for quality-of-life outcomes. This study is registered with ClinicalTrials.gov, number NCT00803062. Findings: Between April 6, 2009, and Jan 3, 2012, a total of 452 patients were enrolled in the trial, of whom 390 completed baseline quality-of-life assessment and at least one further assessment and were therefore evaluable for quality-of-life outcomes. In these patients, patient-reported outcome completion declined from 426 (94%) of 452 (at baseline) to 193 (63%) of 307 (9 months post-cycle 1), but completion rates did not differ significantly between treatment regimens (p=0·78). The baseline FACT-Cx TOI scores did not differ significantly between patients who received bevacizumab versus those who did not (p=0·27). Compared with patients who received chemotherapy alone, patients who received chemotherapy plus bevacizumab reported FACT-Cx TOI scores that were an average of 1·2 points lower (98·75% CI -4·1 to 1·7; p=0·30). Interpretation: Improvements in overall survival and progression-free survival attributed to the incorporation of bevacizumab into the treatment of advanced cervical cancer were not accompanied by any significant deterioration in health-related quality of life. Patients responding to anti-angiogenesis therapy who maintain an acceptable quality of life could be suitable at progression for treatment with other novel therapies that might confer additional benefit. Funding: National Institutes of Health
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