108 research outputs found

    Deliquescence of NaCl–NaNO(3), KNO(3)–NaNO(3), and NaCl–KNO(3 )salt mixtures from 90 to 120°C

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    We conducted reversed deliquescence experiments in saturated NaCl–NaNO(3)–H(2)O, KNO(3)–NaNO(3)–H(2)O, and NaCl–KNO(3)–H(2)O systems from 90 to 120°C as a function of relative humidity and solution composition. NaCl, NaNO(3), and KNO(3 )represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV. Discrepancy between model prediction and experiment can be as high as 8% for relative humidity and 50% for dissolved ion concentration. The discrepancy is attributed primarily to the use of 25°C models for Cl–NO(3 )and K–NO(3 )ion interactions in the current Yucca Mountain Project high-temperature Pitzer model to describe the nonideal behavior of these highly concentrated solutions

    Evaporative evolution of a Na–Cl–NO(3)–K–Ca–SO(4)–Mg–Si brine at 95°C: Experiments and modeling relevant to Yucca Mountain, Nevada

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    A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95°C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and drip shields at the designated high-level, nuclear-waste repository. Solution chemistry, condensed vapor chemistry, and precipitate mineralogy were used to identify important chemical divides and to validate geochemical calculations of evaporating water chemistry using a high temperature Pitzer thermodynamic database. The water evolved toward a complex "sulfate type" brine that contained about 45 mol % Na, 40 mol % Cl, 9 mol % NO(3), 5 mol % K, and less than 1 mol % each of SO(4), Ca, Mg, ∑CO(2)(aq), F, and Si. All measured ions in the condensed vapor phase were below detection limits. The mineral precipitates identified were halite, anhydrite, bassanite, niter, and nitratine. Trends in the solution composition and identification of CaSO(4 )solids suggest that fluorite, carbonate, sulfate, and magnesium-silicate precipitation control the aqueous solution composition of sulfate type waters by removing fluoride, calcium, and magnesium during the early stages of evaporation. In most cases, the high temperature Pitzer database, used by EQ3/6 geochemical code, sufficiently predicts water composition and mineral precipitation during evaporation. Predicted solution compositions are generally within a factor of 2 of the experimental values. The model predicts that sepiolite, bassanite, amorphous silica, calcite, halite, and brucite are the solubility controlling mineral phases

    Large Scale Application of Neural Network Based Semantic Role Labeling for Automated Relation Extraction from Biomedical Texts

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    To reduce the increasing amount of time spent on literature search in the life sciences, several methods for automated knowledge extraction have been developed. Co-occurrence based approaches can deal with large text corpora like MEDLINE in an acceptable time but are not able to extract any specific type of semantic relation. Semantic relation extraction methods based on syntax trees, on the other hand, are computationally expensive and the interpretation of the generated trees is difficult. Several natural language processing (NLP) approaches for the biomedical domain exist focusing specifically on the detection of a limited set of relation types. For systems biology, generic approaches for the detection of a multitude of relation types which in addition are able to process large text corpora are needed but the number of systems meeting both requirements is very limited. We introduce the use of SENNA (“Semantic Extraction using a Neural Network Architecture”), a fast and accurate neural network based Semantic Role Labeling (SRL) program, for the large scale extraction of semantic relations from the biomedical literature. A comparison of processing times of SENNA and other SRL systems or syntactical parsers used in the biomedical domain revealed that SENNA is the fastest Proposition Bank (PropBank) conforming SRL program currently available. 89 million biomedical sentences were tagged with SENNA on a 100 node cluster within three days. The accuracy of the presented relation extraction approach was evaluated on two test sets of annotated sentences resulting in precision/recall values of 0.71/0.43. We show that the accuracy as well as processing speed of the proposed semantic relation extraction approach is sufficient for its large scale application on biomedical text. The proposed approach is highly generalizable regarding the supported relation types and appears to be especially suited for general-purpose, broad-scale text mining systems. The presented approach bridges the gap between fast, cooccurrence-based approaches lacking semantic relations and highly specialized and computationally demanding NLP approaches

    Evaluation of the function and quality of life of patients submitted to girdlestone's resection arthroplasty

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    OBJECTIVES: To evaluate function and quality of life of patients submitted to Girdlestone's arthroplasty, and to compare outcomes between unilateral Girdlestone's group with the group with contralateral total hip prosthesis. METHODS: Cross-sectional study where 9 patients were evaluated with unilateral Girdlestone's and 3 with Girdlestone's in one hip and contralateral total hip prosthesis. The evaluation consisted in filling in a generic questionnaire on quality of life SF-36 and a specific questionnaire for hip function Harris Hip Score (HHS). The comparison between groups was made by using the Student's t-test and the Fisher's test. RESULTS: The patients of the unilateral Girdlestone's group presented a higher number of SF-36 domains classified as high, although 77.8% of these showed poor results on the HHS. All patients had a leg-length discrepancy and positive Trendelenburg's test, which led to limping gait in 11 of 12 patients evaluated. Of these, only 6 underwent physiotherapy after surgery. CONCLUSION: Girdlestone's postoperative quality of life and function in a Brazilian population still requires further studies, because these outcomes are indicative of study variables' behavior and cannot be regarded as definite.OBJETIVOS: Avaliar a função e a qualidade de vida dos pacientes pós-artroplastia de Girdlestone e comparar os resultados entre os grupos Girdlestone unilateral e o grupo com prótese total de quadril contralateral. MÉTODOS: estudo transversal no qual foram avaliados 9 pacientes com Girdlestone unilateral e 3 com Girdlestone em um quadril e prótese total no quadril contralateral. A avaliação constitui-se em aplicar o questionário genérico de qualidade de vida SF-36 e um questionário funcional específico para o quadril, Harris Hip Score (HHS). A comparação dos grupos foi realizada usando-se o teste t- Student e o teste de Fisher. RESULTADOS: Os pacientes do grupo Girdlestone unilateral apresentaram maior quantidade de domínios do SF-36 classificados como elevados, embora 77,8% destes tenham obtido resultados ruins no HHS. Todos os pacientes apresentaram o teste de Trendelenburg positivo e discrepância de membros, o que levou à marcha claudicante em 11 dos 12 pacientes avaliados. Destes, apenas 6 submeteram-se a fisioterapia pós-operatória. CONCLUSÃO: A qualidade de vida e a função pós-operatória de Girdlestone, na população brasileira, ainda necessita ser mais pesquisada, pois estes resultados são indicações do comportamento das variáveis de estudo e não podem ser consideradas encerradas.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Ortopedia e TraumatologiaUNIFESP-EPM DOTUNIFESP, EPM, Depto. de Ortopedia e TraumatologiaUNIFESP, EPM DOTSciEL

    Invasive Predators Deplete Genetic Diversity of Island Lizards

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    Invasive species can dramatically impact natural populations, especially those living on islands. Though numerous examples illustrate the ecological impact of invasive predators, no study has examined the genetic consequences for native populations subject to invasion. Here we capitalize on a natural experiment in which a long-term study of the brown anole lizard (Anolis sagrei) was interrupted by rat invasion. An island population that was devastated by rats recovered numerically following rat extermination. However, population genetic analyses at six microsatellite loci suggested a possible loss of genetic diversity due to invasion when compared to an uninvaded island studied over the same time frame. Our results provide partial support for the hypothesis that invasive predators can impact the genetic diversity of resident island populations

    Catastrophic Floods May Pave the Way for Increased Genetic Diversity in Endemic Artesian Spring Snail Populations

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    The role of disturbance in the promotion of biological heterogeneity is widely recognised and occurs at a variety of ecological and evolutionary scales. However, within species, the impact of disturbances that decimate populations are neither predicted nor known to result in conditions that promote genetic diversity. Directly examining the population genetic consequences of catastrophic disturbances however, is rarely possible, as it requires both longitudinal genetic data sets and serendipitous timing. Our long-term study of the endemic aquatic invertebrates of the artesian spring ecosystem of arid central Australia has presented such an opportunity. Here we show a catastrophic flood event, which caused a near total population crash in an aquatic snail species (Fonscochlea accepta) endemic to this ecosystem, may have led to enhanced levels of within species genetic diversity. Analyses of individuals sampled and genotyped from the same springs sampled both pre (1988–1990) and post (1995, 2002–2006) a devastating flood event in 1992, revealed significantly higher allelic richness, reduced temporal population structuring and greater effective population sizes in nearly all post flood populations. Our results suggest that the response of individual species to disturbance and severe population bottlenecks is likely to be highly idiosyncratic and may depend on both their ecology (whether they are resilient or resistant to disturbance) and the stability of the environmental conditions (i.e. frequency and intensity of disturbances) in which they have evolved

    Rationale and design of the United Kingdom Heart Failure with Preserved Ejection Fraction Registry

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    \ua9 Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.Objective: Heart failure with preserved ejection fraction (HFpEF) is a common heterogeneous syndrome that remains imprecisely defined and consequently has limited treatment options and poor outcomes. Methods: The UK Heart Failure with Preserved Ejection Fraction Registry (UK HFpEF) is a prospective data-enabled cohort and platform study. The study will develop a large, highly characterised cohort of patients with HFpEF. A biobank will be established. Deep clinical phenotyping, imaging, multiomics and centrally held national electronic health record data will be integrated at scale, in order to reclassify HFpEF into distinct subgroups, improve understanding of disease mechanisms and identify new biological pathways and molecular targets. Together, these will form the basis for developing diagnostics and targeted therapeutics specific to subgroups. It will be a platform for more effective and efficient trials, focusing on subgroups in whom targeted interventions are expected to be effective, with consent in place to facilitate rapid recruitment, and linkage for follow-up. Patients with a diagnosis of HFpEF made by a heart failure specialist, who have had natriuretic peptide levels measured and a left ventricular ejection fraction >40% are eligible. Patients with an ejection fraction between 40% and 49% will be limited to no more than 25% of the cohort. Conclusions: UK HFpEF will develop a rich, multimodal data resource to enable the identification of disease endotypes and develop more effective diagnostic strategies, precise risk stratification and targeted therapeutics. Trial registration number: NCT05441839

    Barriers to adequate follow-up during adjuvant therapy may be important factors in the worse outcome for Black women after breast cancer treatment

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    <p>Abstract</p> <p>Introduction</p> <p>Black women appear to have worse outcome after diagnosis and treatment of breast cancer. It is still unclear if this is because Black race is more often associated with known negative prognostic indicators or if it is an independent prognostic factor. To study this, we analyzed a patient cohort from an urban university medical center where these women made up the majority of the patient population.</p> <p>Methods</p> <p>We used retrospective analysis of a prospectively collected database of breast cancer patients seen from May 1999 to June 2006. Time to recurrence and survival were analyzed using the Kaplan-Meier method, with statistical analysis by chi-square, log rank testing, and the Cox regression model.</p> <p>Results</p> <p>265 female patients were diagnosed with breast cancer during the time period. Fifty patients (19%) had pure DCIS and 215 patients (81%) had invasive disease. Racial and ethnic composition of the entire cohort was as follows: Black (N = 150, 56.6%), Hispanic (N = 83, 31.3%), Caucasian (N = 26, 9.8%), Asian (N = 4, 1.5%), and Arabic (N = 2, 0.8%). For patients with invasive disease, independent predictors of poor disease-free survival included tumor size, node-positivity, incompletion of adjuvant therapy, and Black race. Tumor size, node-positivity, and Black race were independently associated with disease-specific overall survival.</p> <p>Conclusion</p> <p>Worse outcome among Black women appears to be independent of the usual predictors of survival. Further investigation is necessary to identify the cause of this survival disparity. Barriers to completion of standard post-operative treatment regimens may be especially important in this regard.</p

    The Servant Leadership Survey: Development and Validation of a Multidimensional Measure

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    Purpose: The purpose of this paper is to describe the development and validation of a multi-dimensional instrument to measure servant leadership. Design/Methodology/Approach Based on an extensive literature review and expert judgment, 99 items were formulated. In three steps, using eight samples totaling 1571 persons from The Netherlands and the UK with a diverse occupational background, a combined exploratory and confirmatory factor analysis approach was used. This was followed by an analysis of the criterion-related validity. Findings: The final result is an eight-dimensional measure of 30 items: the eight dimensions being: standing back, forgiveness, courage, empowerment, accountability, authenticity, humility, and stewardship. The internal consistency of the subscales is good. The results show that the Servant Leadership Survey (SLS) has convergent validity with other leadership measures, and also adds unique elements to the leadership field. Evidence for criterion-related validity came from studies relating the eight dimensions to well-being and performance. Implications: With this survey, a valid and reliable instrument to measure the essential elements of servant leadership has been introduced. Originality/Value The SLS is the first measure where the underlying factor structure was developed and confirmed across several field studies in two countries. It can be used in future studies to test the underlying premises of servant leadership theory. The SLS provides a clear picture of the key servant leadership qualities and shows where improvements can be made on the individual and organizational level; as such, it may also offer a valuable starting point for training and leadership development
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