618 research outputs found

    Granular size segregation in underwater sand ripples

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    We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The initial wavelength of the mixture is measured. In the final steady state, a segregation in volume is observed instead of a segregation at the surface as reported before. The correlation between this phenomenon and the fluid flow is emphasised. Finally, different ``exotic'' patterns and their geophysical implications are presented.Comment: 8 page

    An Evaluation of Managing and Educating Patients on the Risk of Glucocorticoid-Induced Osteoporosis

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    AbstractObjectiveTo assess the impact of risk management activities on patient risk of glucocorticoid-induced osteoporosis.MethodsNinety-six adult patients taking chronic glucocorticoid therapy in 15 community pharmacies. Patients in the control group received usual and customary care. Patients in the treatment pharmacies received education and an educational pamphlet about the risks of glucocorticoid-induced osteoporosis. In addition, the treatment group pharmacists monitored the patients' drug therapy, to identify and address drug-related problems. Data including the glucocorticoid taken by the patient, medications, and osteoporosis risk factors were collected at baseline and after 9 months of monitoring, via Web-based survey completed in the pharmacy. Using an intent to treat approach, the pre–post frequency changes were compared with contrasts for presence of bisphosphonate therapy, presence of estrogen therapy, presence of calcium supplement, discussion of glucocorticoid-induced osteoporosis risk, discussion of bone density test, presence of bone mineral density test, reported inactivity, and reported low calcium diet.ResultsThe contrast was significant in favor of the treatment pharmacies for the frequency of patients taking a calcium supplement (Control [−6.9%] vs. Treatment [17.1%], P < 0.05). No other contrast was significant.ConclusionsCommunity pharmacists are capable of increasing calcium supplementation among patients at risk for glucocorticoid-induced osteoporosis. Pharmacists who educate at-risk patients can impact the self-care of these patients

    Pharmacist Contributions to the U.S. Health Care System

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    Objective: The overall goal for this study was to conduct a segment analysis of the pharmacist workforce during 2009 based upon time spent in medication providing and in patient care services. Methods: Data for this study were obtained from the 2009 National Pharmacist Workforce Survey in which a random sample of 3,000 pharmacists was selected. Cluster analysis was used for identifying pharmacist segments and descriptive statistics were used for describing and comparing segments.Results: Of the 2,667 surveys that were presumed to be delivered to a pharmacist, 1,395 were returned yielding a 52.3% overall response rate. Of these, 1,200 responses were usable for cluster analysis. Findings from this study revealed five segments ofpharmacists: (1) Medication Providers, (2) Medication Providers who also Provide Patient Care, (3) Other Activity Pharmacists, (4) Patient Care Providers Who also Provide Medication, and (5) Patient Care Providers. The results showed that, in 2009, 41% of U.S. pharmacists were devoted wholly to medication providing (Medication Providers). Forty-three percent of pharmacists contributed significantly to patient care service provision (Medication Providers who also Provide Patient Care, Patient Care Providers who also Provide Medication, and Patient Care Providers) and the remaining 16% (Other Activity Pharmacists) contributed most of their time to business / organization management, research, education, and other health-system improvement activities. Conclusions: Based on the findings, we propose that the pharmacy profession currently has, and will continue to build, capacity for contributing to the U.S. health care system in new roles for which they have been identified. However, as shifts in professional roles occur, a great deal of capacity is required related to new service provision. Resources are scarce, so an understanding of the most appropriate timing for making such changes can lead to cost-effective use of limited resources for improving patient care

    Genomic constitution of an H-2:Tla variant leukemia.

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    Assessment of HCC response to Yttrium-90 radioembolization with gadoxetate disodium MRI: correlation with histopathology.

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    Transarterial &lt;sup&gt;90&lt;/sup&gt; Y radioembolization (TARE) is increasingly being used for hepatocellular carcinoma (HCC) treatment. However, tumor response assessment after TARE may be challenging. We aimed to assess the diagnostic performance of gadoxetate disodium MRI for predicting complete pathologic necrosis (CPN) of HCC treated with TARE, using histopathology as the reference standard. This retrospective study included 48 patients (M/F: 36/12, mean age: 62 years) with HCC treated by TARE followed by surgery with gadoxetate disodium MRI within 90 days of surgery. Two radiologists evaluated tumor response using RECIST1.1, mRECIST, EASL, and LI-RADS-TR criteria and evaluated the percentage of necrosis on subtraction during late arterial, portal venous, and hepatobiliary phases (AP/PVP/HBP). Statistical analysis included inter-reader agreement, correlation between radiologic and pathologic percentage of necrosis, and prediction of CPN using logistic regression and ROC analyses. Histopathology demonstrated 71 HCCs (2.8 ± 1.7 cm, range: 0.5-7.5 cm) including 42 with CPN, 22 with partial necrosis, and 7 without necrosis. EASL and percentage of tumor necrosis on subtraction at the AP/PVP were independent predictors of CPN (p = 0.02-0.03). Percentage of necrosis, mRECIST, EASL, and LI-RADS-TR had fair to good performance for diagnosing CPN (AUCs: 0.78 - 0.83), with a significant difference between subtraction and LI-RADS-TR for reader 2, and in specificity between subtraction and other criteria for both readers (p-range: 0.01-0.04). Radiologic percentage of necrosis was significantly correlated to histopathologic degree of tumor necrosis (r = 0.66 - 0.8, p &lt; 0.001). Percentage of tumor necrosis on subtraction and EASL criteria were significant independent predictors of CPN in HCC treated with TARE. Image subtraction should be considered for assessing HCC response to TARE when using MRI. • Percentage of tumor necrosis on image subtraction and EASL criteria are significant independent predictors of complete pathologic necrosis in hepatocellular carcinoma treated with &lt;sup&gt;90&lt;/sup&gt; Y radioembolization. • Subtraction, mRECIST, EASL, and LI-RADS-TR have fair to good performance for diagnosing complete pathologic necrosis in hepatocellular carcinoma treated with &lt;sup&gt;90&lt;/sup&gt; Y radioembolization

    Diversity and toxicity of Pseudo-nitzschia species in Monterey Bay : perspectives from targeted and adaptive sampling

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    Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 78 (2018): 129-141, doi:10.1016/j.hal.2018.08.006.Monterey Bay, California experiences near-annual blooms of Pseudo-nitzschia that can affect marine animal health and the economy, including impacts to tourism and commercial/recreational fisheries. One species in particular, P. australis, has been implicated in the most toxic of events, however other species within the genus can contribute to widespread variability in community structure and associated toxicity across years. Current monitoring methods are limited in their spatial coverage as well as their ability to capture the full suite of species present, thereby hindering understanding of HAB events and limiting predictive accuracy. An integrated deployment of multiple in situ platforms, some with autonomous adaptive sampling capabilities, occurred during two divergent bloom years in the bay, and uncovered detailed aspects of population and toxicity dynamics. A bloom in 2013 was characterized by spatial differences in Pseudo39 nitzschia populations, with the low-toxin producer P. fraudulenta dominating the inshore community and toxic P. australis dominating the offshore community. An exceptionally toxic bloom in 2015 developed as a diverse Pseudo-nitzschia community abruptly transitioned into a bloom of highly toxic P. australis within the time frame of a week. Increases in cell density and proliferation coincided with strong upwelling of nutrients. High toxicity was driven by silicate limitation of the dense bloom. This temporal shift in species composition mirrored the shift observed further north in the California Current System off Oregon and Washington. The broad scope of sampling and unique platform capabilities employed during these studies revealed important patterns in bloom formation and persistence for Pseudo-nitzschia. Results underscore the benefit of expanded biological observing capabilities and targeted sampling methods to capture more comprehensive spatial and temporal scales for studying and predicting future events.This work was supported by the National Oceanic and Atmospheric Administration (NA11NOS4780055, NA11NOS4780056, NA11NOS4780030) and a fellowship to H. Bowers from the Packard Foundation

    Dimensions of professional competences for interventions towards sustainability

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    This paper investigates sustainability competences through the eyes of professional practitioners in the field of sustainability and presents empirical data that have been created using an action research approach. The design of the study consists of two workshops, in which professional practitioners in interaction with each other and the facilitators are invited to explore and reflect on the specific knowledge, skills, attitudes and behaviours necessary to conduct change processes successfully towards sustainability in a variety of business and professional contexts. The research focuses on the competences associated with these change processes to devise, propose and conduct appropriate interventions that address sustainability issues. Labelled ‘intervention competence’, this ability comprises an interlocking set of knowledge, skills, attitudes and behaviours that include: appreciating the importance of (trying to) reaching decisions or interventions; being able to learn from lived experience of practice and to connect such learning to one’s own scientific knowledge; being able to engage in political-strategic thinking, deliberations and actions, related to different perspectives; the ability for showing goal-oriented, adequate action; adopting and communicating ethical practices during the intervention process; being able to cope with the degree of complexity, and finally being able to translate stakeholder diversity into collectively produced interventions (actions) towards sustainability. Moreover, this competence has to be practised in contexts of competing values, non-technical interests and power relations. The article concludes with recommendations for future research and practice

    Updating Photon-Based Normal Tissue Complication Probability Models for Pneumonitis in Patients With Lung Cancer Treated With Proton Beam Therapy

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    Purpose: No validated models for predicting the risk of radiation pneumonitis (RP) with proton beam therapy (PBT) currently exist. Our goal was to externally validate and recalibrate multiple established photon-based normal tissue complication probability models for RP in a cohort with locally advanced nonsmall cell lung cancer treated with contemporary doses of chemoradiation using PBT. Methods and Materials: The external validation cohort consisted of 99 consecutive patients with locally advanced nonsmall cell lung cancer treated with chemoradiation using PBT. RP was retrospectively scored at 3 and 6 months posttreatment. We evaluated the performance of the photon Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) pneumonitis model, the QUANTEC model adjusted for clinical risk factors, and the newer Netherlands updated QUANTEC model. A closed testing procedure was performed to test the need for model updating, either by recalibration-in-the-large (re-estimation of intercept), recalibration (re-estimation of intercept/slope), or model revision (re-estimation of all coefficients). Results: There were 21 events (21%) of ≥grade 2 RP. The closed testing procedure on the PBT data set did not detect major deviations between the models and the data and recommended adjustment of the intercept only for the photon-based Netherlands updated QUANTEC model (intercept update: –1.2). However, an update of the slope and revision of the model coefficients were not recommended by the closed testing procedure, as the deviations were not significant within the power of the data. Conclusions: The similarity between the dose-response relationship for PBT and photons for normal tissue complications has been an assumption until now. We demonstrate that the preexisting, widely used photon based models fit our PBT data well with minor modifications. These now-validated and updated normal tissue complication probability models can aid in individualizing selection of the most optimal treatment technique for a particular patient

    Striking the Right Balance of Intermolecular Coupling for High-Efficiency Singlet Fission

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    Singlet fission is a process that splits collective excitations, or excitons, into two with unity efficiency. This exciton splitting process, unique to molecular photophysics, has the potential to considerably improve the efficiency of optoelectronic devices through more efficient light harvesting. While the first step of singlet fission has been characterized in great detail, subsequent steps critical to achieving overall highly-efficient singlet-to-triplet conversion are only just beginning to become well understood. One of the most elementary suggestions, which has yet to be tested, is that an appropriately balanced coupling is necessary to ensure overall highly efficient singlet fission; that is, the coupling needs to be strong enough so that the first step is fast and efficient, yet weak enough to ensure the independent behavior of the resultant triplets. In this work, we show how high overall singlet-to-triplet conversion efficiencies can be achieved in singlet fission by ensuring that the triplets comprising the triplet pair behave as independently as possible. We show that side chain sterics govern local packing in amorphous pentacene derivative nanoparticles, and that this in turn controls both the rate at which triplet pairs form and the rate at which they decay. We show how compact side chains and stronger couplings promote a triplet pair that effectively couples to the ground state, whereas bulkier side chains promote a triplet pair that appears more like two independent and long-lived triplet excitations. Our results show that the triplet pair is not emissive, that its decay is best viewed as internal conversion rather than triplet–triplet annihilation, and perhaps most critically that, in contrast to a number of recent suggestions, the triplets comprising the initially formed triplet pair cannot be considered independently. This work represents a significant step toward better understanding intermediates in singlet fission, and how molecular packing and couplings govern overall triplet yields

    Practising lawyers in Nova Scotia: cognitive style and preferences for practice

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    The Cognitive Style Index and a demographic survey were administered to 524 practising lawyers in Nova Scotia. Results indicate that lawyers, as a group, have a more analytical than intuitive cognitive style. Differences between men and women and between partners and associates were nonsignificant statistically. This finding suggests lawyers are a more homogeneous group in terms of cognitive style than other groups such as law students and various groups of business managers. However, lawyers differed significantly in cognitive style across various preferred areas of practice. For example, those preferring criminal law scored statistically significantly lower on the Cognitive Style Index than those who preferred Real Estate and Construction law. Organizational behavior implications are discussed
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