599 research outputs found

    DESORPTION YIELDS USING keV POLYATOMIC PROJECTILES

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    We have studied the negative secondary ion emission from solid organic targets bombarded by molecular ions and cluster ions. As an example we present here the results obtained with the compound phenylalanine. We have used organic projectiles of mass 73 [Si (CH3)+], 147[Si(CH3)3 OSi(CH3)2+], 300 [molecular ion of coronene C24H12]+, 598 [coronene dimer 2(M-H)]+, and atomic and polyatomic ions of mass 133 [Cs]+, 393 [Cs2I]+, 653 [Cs3I2]+. These primary ions have been produced in the bombardment of targets of coronene and CsI by fission fragment from a 252Cf source. They were accelerated and focussed on the sample target. Sophisticated time of flight measurements of the primary and secondary ions have been performed with a special data acquisition system. All the time of flight mass spectra were recorded at one. The secondary molecular ion yield of the phenilalanine (M-H)- = 164 has been studied as a function of the energy of impact and of the mass of the projectile. A large enhancement of the yield with the mass and the energy is observed

    Spectral Sensitivity in Ray-Finned Fishes: Diversity, Ecology and Shared Descent

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    A major goal of sensory ecology is to identify factors that underlie sensory-trait variation. One open question centers on why fishes show the greatest diversity among vertebrates in their capacity to detect color (i.e. spectral sensitivity). Over the past several decades, λmax values (photoreceptor class peak sensitivity) and chromacy (photoreceptor class number) have been cataloged for hundreds of fish species, yet the ecological basis of this diversity and the functional significance of high chromacy levels (e.g. tetra- and pentachromacy) remain unclear. In this study, we examined phylogenetic, physiological and ecological patterns of spectral sensitivity of ray-finned fishes (Actinoptergyii) via a meta-analysis of data compiled from 213 species. Across the fishes sampled, our results indicate that trichromacy is most common, ultraviolet λmax values are not found in monochromatic or dichromatic species, and increasing chromacy, including from tetra- to pentachromacy, significantly increases spectral sensitivity range. In an ecological analysis, multivariate phylogenetic latent liability modeling was performed to analyze correlations between chromacy and five hypothesized predictors (depth, habitat, diet, body coloration, body size). In a model not accounting for phylogenetic relatedness, each predictor with the exception of habitat significantly correlated with chromacy: a positive relationship in body color and negative relationships with body size, diet and depth. However, after phylogenetic correction, the only remaining correlated predictor was depth. The findings of this study indicate that phyletic heritage and depth are important factors in fish spectral sensitivity and impart caution about excluding phylogenetic comparative methods in studies of sensory trait variation

    Assessing quality of life in a clinical study on heart rehabilitation patients: how well do value sets based on given or experienced health states reflect patients' valuations?

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    Background: Quality of life as an endpoint in a clinical study may be sensitive to the value set used to derive a single score. Focusing on patients' actual valuations in a clinical study, we compare different value sets for the EQ-5D-3L and assess how well they reproduce patients' reported results. Methods: A clinical study comparing inpatient (n = 98) and outpatient (n = 47) rehabilitation of patients after an acute coronary event is re-analyzed. Value sets include: 1. Given health states and time-trade-off valuation (GHS-TTO) rendering economic utilities;2. Experienced health states and valuation by visual analog scale (EHS-VAS). Valuations are compared with patient-reported VAS rating. Accuracy is assessed by mean absolute error (MAE) and by Pearson's correlation.. External validity is tested by correlation with established MacNew global scores. Drivers of differences between value sets and VAS are analyzed using repeated measures regression. Results: EHS-VAS had smaller MAEs and higher. in all patients and in the inpatient group, and correlated best with MacNew global score. Quality-adjusted survival was more accurately reflected by EHS-VAS. Younger, better educated patients reported lower VAS at admission than the EHS-based value set. EHS-based estimates were mostly able to reproduce patient-reported valuation. Economic utility measurement is conceptually different, produced results less strongly related to patients' reports, and resulted in about 20 % longer quality-adjusted survival. Conclusion: Decision makers should take into account the impact of choosing value sets on effectiveness results. For transferring the results of heart rehabilitation patients from another country or from another valuation method, the EHS-based value set offers a promising estimation option for those decision makers who prioritize patient-reported valuation. Yet, EHS-based estimates may not fully reflect patient-reported VAS in all situations

    Transcript quantification with RNA-Seq data

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    Motivation Novel high-throughput sequencing technologies open exciting new approaches to transcriptome profiling. Sequencing transcript populations of interest, e.g. from different tissues or variable stress conditions, with RNA sequencing (RNA-Seq) [1] generates millions of short reads. Accurately aligned to a reference genome, they provide digital counts and thus facilitate transcript quantification. As the observed read counts only provide the summation of all expressed sequences at one locus, the inference of the underlying transcript abundances is crucial for further quantitative analyses. Methods To approach this problem, we have developed a new technique, called rQuant, based on quadratic programming. Given a gene annotation and position-wise exon/intron read coverage from read alignments, we determine the abundances for each annotated transcript by minimising a suitable loss function. It penalises the deviation of the observed from the expected read coverage given the transcript weights. The observed read coverage is typically non-uniformly distributed over the transcript due to several biases in the generation of the sequencing libraries and the sequencing. This leads to distortions of the transcript abundances, if not corrected properly. We therefore extended our approach to jointly optimise transcript profiles, modeling the coverage deviations depending on the position in the transcript. Our method can be applied without knowledge of the underlying transcript abundances and equally benefits from loci with and without alternative transcripts. Results To quantitatively evaluate the quality of our abundance predictions, we used a set of simulated reads from transcripts with known expression as a benchmark set. It was generated using the Flux Simulator [2] modeling biases in RNA-Seq as well as preparation experiments. Table 1 shows preliminary results with segment- and position-based loss as well as with and without the transcript profiles. Our results indicate that the position-based modeling together with transcript profiles allows us to accurately infer the underlying expression of single transcripts as well as of multiple isoforms of one gene locus

    Smoking and health-related quality of life in English general population: Implications for economic evaluations

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    Copyright @ 2012 Vogl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Little is known as to how health-related quality of life (HRQoL) when measured by generic instruments such as EQ-5D differ across smokers, ex-smokers and never-smokers in the general population; whether the overall pattern of this difference remain consistent in each domain of HRQoL; and what implications this variation, if any, would have for economic evaluations of tobacco control interventions. Methods: Using the 2006 round of Health Survey for England data (n = 13,241), this paper aims to examine the impact of smoking status on health-related quality of life in English population. Depending upon the nature of the EQ-5D data (i.e. tariff or domains), linear or logistic regression models were fitted to control for biology, clinical conditions, socio-economic background and lifestyle factors that an individual may have regardless of their smoking status. Age- and gender-specific predicted values according to smoking status are offered as the potential 'utility' values to be used in future economic evaluation models. Results: The observed difference of 0.1100 in EQ-5D scores between never-smokers (0.8839) and heavy-smokers (0.7739) reduced to 0.0516 after adjusting for biological, clinical, lifestyle and socioeconomic conditions. Heavy-smokers, when compared with never-smokers, were significantly more likely to report some/severe problems in all five domains - mobility (67%), self-care (70%), usual activity (42%), pain/discomfort (46%) and anxiety/depression (86%) -. 'Utility' values by age and gender for each category of smoking are provided to be used in the future economic evaluations. Conclusion: Smoking is significantly and negatively associated with health-related quality of life in English general population and the magnitude of this association is determined by the number of cigarettes smoked. The varying degree of this association, captured through instruments such as EQ-5D, may need to be fed into the design of future economic evaluations where the intervention being evaluated affects (e.g. tobacco control) or is affected (e.g. treatment for lung cancer) by individual's (or patients') smoking status

    Machine-learning-aided prediction of brain metastases development in non-small-cell lung cancers

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    Purpose Non–small-cell lung cancer (NSCLC) shows a high incidence of brain metastases (BM). Early detection is crucial to improve clinical prospects. We trained and validated classifier models to identify patients with a high risk of developing BM, as they could potentially benefit from surveillance brain MRI. Methods Consecutive patients with an initial diagnosis of NSCLC from January 2011 to April 2019 and an in-house chest-CT scan (staging) were retrospectively recruited at a German lung cancer center. Brain imaging was performed at initial diagnosis and in case of neurological symptoms (follow-up). Subjects lost to follow-up or still alive without BM at the data cut-off point (12/2020) were excluded. Covariates included clinical and/or 3D-radiomics-features of the primary tumor from staging chest-CT. Four machine learning models for prediction (80/20 training) were compared. Gini Importance and SHAP were used as measures of importance; sensitivity, specificity, area under the precision-recall curve, and Matthew's Correlation Coefficient as evaluation metrics. Results Three hundred and ninety-five patients compromised the clinical cohort. Predictive models based on clinical features offered the best performance (tuned to maximize recall: sensitivity∼70%, specificity∼60%). Radiomics features failed to provide sufficient information, likely due to the heterogeneity of imaging data. Adenocarcinoma histology, lymph node invasion, and histological tumor grade were positively correlated with the prediction of BM, age, and squamous cell carcinoma histology were negatively correlated. A subgroup discovery analysis identified 2 candidate patient subpopulations appearing to present a higher risk of BM (female patients + adenocarcinoma histology, adenocarcinoma patients + no other distant metastases). Conclusion Analysis of the importance of input features suggests that the models are learning the relevant relationships between clinical features/development of BM. A higher number of samples is to be prioritized to improve performance. Employed prospectively at initial diagnosis, such models can help select high-risk subgroups for surveillance brain MRI

    Relaxation and chronic pain: A critical review

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    YesChronic non-malignant pain is a global condition with a complex biopsychosocial impact on the sufferers. Relaxation skills are commonly included as part of a pain management programme, which is currently the recommended evidence-based intervention for this group of patients. However, there is little evidence behind the choice of relaxation method implemented, or their effectiveness. The aim of this study was to investigate the effectiveness of relaxation skills in the management of chronic non-malignant pain, related to pain intensity and health-related quality of life. A systematic literature review was conducted using MEDLINE, CINAHL, AMED, PEDro and PsycARTICLES. The Cochrane, DARE and Trip databases were also accessed, and searches were carried out using the terms (relaxation OR relaxation therapy OR relaxation training) AND (pain OR chronic pain). Following critical appraisal, ten studies met the inclusion criteria. Three studies reported a decrease in pain intensity as a result of the relaxation intervention, whilst only one study reported an improvement in health-related quality of life. Progressive muscle relaxation was the most commonly implemented method throughout, although its method of delivery differed between studies. There is little evidence for the use of relaxation as a stand-alone intervention for pain intensity and health-related quality of life for patients with musculoskeletal chronic non-malignant pain. More research is needed to determine its effectiveness

    Elaboração e análise de um estudo de viabilidade económica para implementação de um projecto de floricultura em estufa

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    O presente trabalho trata de um Plano de Negócios, onde será estudado e avaliado a viabilidade económica – financeira de um Projecto de Floricultura ligado à produção intensiva de rosas em estufa. A área produtiva do empreendimento ocupará aproximadamente 4096 metros quadrados cobertos, sendo o funcionamento e gestão do processo de produção assegurado através do uso de tecnologias e métodos que premeiam a inovação e o desenvolvimento sustentável. As instalações de apoio à actividade produtiva, serão dimensionadas para ocupar aproximadamente 494 metros quadrados, e incluem áreas destinadas à gestão estratégica e administrativa do negócio, conservação, embalagem e expedição do produto. Aborda-se aqui o conceito de empreendedorismo de oportunidade num cenário de mercado em que a procura do produto tende a exceder a oferta no contexto nacional; ABSTRACT: This work is about a Business Plan, where a viability of a Floriculture Project will be economically and financially studied and evaluated taking into account the intensive production of Roses in a Greenhouse. The productive area of the project will be around 4096 covered square meters, where the management and functionality of the production process will be assured through the use of methods and technologies that reward innovation and sustainable development. The premises that support all the productive activity will be dimensioned in order to fit around 494 square meters, strategic management, maintenance, packing, product flow and business administration will be included. On an entrepreneurship concept opportunity this market scenario is looking after a product that exceeds the offer on a national context

    Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up

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    Objective: Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD. Design: Cross-sectional surveys linked to hospital admissions and death records. Subjects: 19 329 adults (aged 18–86 years) from a representative sample of the Scottish population. Measurements: Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption. Results: For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38). Conclusions: In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences
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