Heterodyne observations of Neptune have provided a measurement of the CO(2–1) line profile with a total bandpass of almost 8 GHz and a resolution of 4 MHz. The lineshape indicates that the CO mole ...fraction in Neptune's atmosphere is not uniform, but increases by a factor of ~2 from the troposphere/lower stratosphere (0.5 ppm at $p>20$ mbar) to the upper stratosphere (1 ppm at $p<20$ mbar). This indicates the existence of both external and internal sources of CO. The equivalent flux associated with the external source is ~$1\times10^8$ cm-2 s-1. We propose that the stratospheric CO results from a large (2 km) cometary impact that occurred ~200 years ago, although there remains problems with this hypothesis.
Path-planning is a well-known studied problem in Artificial Intelligence. Given two points in a map, path-planning algorithms search for a path that joins those two points, avoiding obstacles. It is ...a challenging problem with important practical applications in a wide range of applications: autonomous mobile robotics, logistics or video games, just to mention some of them. Given its importance, it has attracted much research, resulting in a large number of algorithms, some classical, such as A*, other more specialized, such as swarms. However, despite all the literature dedicated to this problem, the statistics used to analyze experimental results in most cases are naive. In this paper, we position in favor of the need of incorporating stronger statistical methods in path-planning empirical research and promote a debate in the research community. To this end, we analyze some 2D-grid classical path-planning algorithms in discrete domains (i.e. A* and A* with post-processing) and more recent algorithms in continuous domains (i.e. Theta* and S-Theta*). Given the differences of these algorithms, we study them under different criteria: Run-time, number of heading changes, number of expanded vertices and path-length.
Un bon exemple d’exigence éthique en même temps que théorique, en philosophie, est celui de l’évolution de la conception de relation interne ou propriété interne dans la pensée de Wittgenstein, du ...Tractatus à ses derniers écrits. Ce qui en réalité peut surprendre, dans cet exemple, est de constater une proximité complexe entre deux domaines traditionnellement aussi éloignés que ceux de l’Éthique et de l’Épistémologie.
Quantitative trait locus (QTL) mapping by pooled-segregant whole-genome sequencing in yeast is a robust methodology for the simultaneous identification of superior genes involved in polygenic traits ...(e.g., high ethanol tolerance). By crossing two haploid strains with opposite phenotypes, being one of interest, the resulting diploid is sporulated, the meiotic segregants phenotyped, and a pool of selected segregants with the phenotype of interest assembled. The genotyping by pooled-segregant sequencing constitutes a fast and reliable methodology to map all QTL defining the trait of interest. The QTLs can be further analyzed by reciprocal hemizygosity analysis to identify the causative superior alleles that can subsequently be used for yeast strain improvement by targeted genetic engineering.
Evidence-based medicine (EBM) is defined as the integration of the best available evidence from scientific studies with clinical experience (and context) and with patients' values and preferences. ...The objective of the present study was to describe self-perceived EBM competencies in physicians and medical students enrolled in a massive virtual EBM course.
Analytical cross-sectional study. People interested in a free virtual EBM course fulfilled their data in a virtual form for their registration in September 2020. In this form, 22 competencies related to four dimensions of EBM were evaluated: asking a clinical question, search, analysis, and application; using a 5-option Likert scale. The resulting database was analyzed, selecting people who claimed to be physicians or medical students of 18 years or more.
1793 participants were included: 1130 medical students and 663 physicians; more than 80% lived in Peru. The frequency of participants who agreed or strongly agreed with feeling qualified in each competence ranged: from 39.2% to 57.8% for the competencies of the 'Asking a clinical question' dimension, from 39.2% to 56.1% for 'Search,' from 19.9% to 32.0% for 'Analysis,' and from 19.6% to 29.9% for 'Application.' Both in physicians and students, the lowest frequencies were for the competencies of interpretation of impact measures, graphs, and results of systematic reviews; as well as shared decision making and calculation of expected benefit. Physicians who graduated more recently scored better on competencies from search and analysis dimensions.
Among physicians and medical students enrolled in the course, self-perception of competencies was lower in the dimensions of analysis and application. More recently graduated physicians seem to have a greater self-perception of their research and analysis skills, probably due to curricular updates.
List of abbreviations: EBM: Evidence-based medicine; CIMBE, for its acronym in Spanish: International Course on Evidence-Based Medicine; SOCIMEP, for its acronym in Spanish: Peruvian Medical Student Scientific Society
The logistic sector raises a number of highly challenging problems. Probably one of the most important ones is the shipping planning, i.e. plan the routes that the shippers have to follow to deliver ...the goods. In this article, we present an artificial intelligence-based solution that has been designed to help a logistic company to improve its routes planning process. In order to achieve this goal, the solution uses the knowledge acquired by the company drivers to propose optimised routes. Hence, the proposed solution gathers the experience of the drivers, processes it and optimises the delivery process. The solution uses data mining to extract knowledge from the company information systems and prepares it for analysis with a case-based reasoning (CBR) algorithm. The CBR obtains critical business intelligence knowledge from the drivers experience that is needed by the planner. The design of the routes is done by a genetic algorithm that, given the processed information, optimises the routes following several objectives, such as minimise the distance or time. Experimentation shows that the proposed approach is able to find routes that improve, on average, the routes made by the human experts.
Summary
Background Liver stiffness measurements may have potential for detecting and monitoring hepatic fibrosis in chronic liver disease.
Aim To study the detection, quantification and progression ...of hepatic fibrosis in primary biliary cirrhosis by liver stiffness measurements.
Methods Liver stiffness measurements were generated in 80 patients with primary biliary cirrhosis by applying transient elastography; however, as there were 55 with liver biopsy, histological stage (METAVIR) and liver stiffness measurements were compared only in these 55 patients. The efficiency of liver stiffness measurements in predicting stage of fibrosis was determined from the area under receiver operating characteristics curve analysis.
Results Of the 80 patients included, 91, 4% were women and their mean age was 56 ± 12 (s.d.) years. A significant correlation was found (P < 0.05) between histological fibrosis stage (METAVIR) and liver stiffness measurements. The values obtained from area under receiver operating characteristic curve analysis of liver stiffness measurement data were 0.89 for F > 2 and 0.96 for F = 4. Liver stiffness measurements were 9.0 ± 5.3 and 7.9 ± 6.0 kPa for patients followed up more than 5 years and less than 5 years, respectively (P > 0.05).
Conclusions In patients with primary biliary cirrhosis, median values of liver stiffness measurements correlated with histological severity of hepatic fibrosis. Liver stiffness measurements appear to be promising for liver fibrosis detection and quantification, as well as monitoring its progression, in patients with primary biliary cirrhosis. The progression rate of hepatic fibrosis in our primary biliary cirrhosis patients appears to be slow.
A stent is a device designed to restore flow through constricted arteries. These tubular scaffold devices are delivered to the afflicted region and deployed using minimally invasive techniques. ...Stents must have sufficient radial strength to prop the diseased artery open. The presence of a stent can subject the artery to abnormally high stresses that can trigger adverse biologic responses culminating in restenosis. The primary aim of this investigation was to investigate the effects of varying stent "design parameters" on the stress field induced in the normal artery wall and the radial displacement achieved by the stent. The generic stent models were designed to represent a sample of the attributes incorporated in present commercially available stents. Each stent was deployed in a homogeneous, nonlinear hyperelastic artery model and evaluated using commercially available finite element analysis software. Of the designs investigated herein, those employing large axial strut spacing, blunted corners, and higher amplitudes in the ring segments induced high circumferential stresses over smaller areas of the artery's inner surface than all other configurations. Axial strut spacing was the dominant parameter in this study, i.e., all designs employing a small stent strut spacing induced higher stresses over larger areas than designs employing the large strut spacing. Increasing either radius of curvature or strut amplitude generally resulted in smaller areas exposed to high stresses. At larger strut spacing, sensitivity to radius of curvature was increased in comparison to the small strut spacing. With the larger strut spacing designs, the effects of varying amplitude could be offset by varying the radius of curvature and vice versa. The range of minimum radial displacements from the unstented diastolic radius observed among all designs was less than 90 microm. Evidence presented herein suggests that stent designs incorporating large axial strut spacing, blunted corners at bends, and higher amplitudes exposed smaller regions of the artery to high stresses, while maintaining a radial displacement that should be sufficient to restore adequate flow.
The aim of this study was to quantify the level of burnout and competence for evidence-based practice among Spanish physical therapists and to determine if there is a relationship between these and ...other socio-professional factors. A cross-sectional study with 472 Spanish Physiotherapists. An electronic survey was conducted that included the Maslach Burnout Inventory, Evidence-Based Practice Questionnaire and sociodemographic data. The three subscales of the Burnout correlated with attitude and total Evidence-Based Practice Questionnaire. Attitude and practice for evidence-based practice, educational level and experience were the variables that showed the greatest influence on burnout. Burnout and the degree of evidence-based practice were identified as being discretely related. Specifically, it seems that the evidence-based practice could improve the lack of personal accomplishment, meaning that through interventions perceived as more effective and advantageous, a sense of mastery and self-efficacy is experienced.
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