1,720,991 research outputs found
Modelling patient length of stay in public hospitals in Mexico
No full textThis thesis is concerned with the modelling of patient length of stay in public hospitals in Mexico. Patient length of stay is the most commonly worldwide employed outcome measure for hospital resource consumption and performance monitoring. Most of the hospitals around the world use average length of stay as starting point for resource planning. However average estimates frequently gives non-accurate results due to the high variability of the length of stay data. The reason for such high variability may be attributable to the diversity in the patient population and the environment where the patient is treated.Through a systematic review of the literature on methods and models in the field of calculating and predicting patient length of stay, this research highlights the areas of opportunity and research gap from previous studies and practices, and proposes the use of finite mixture models to approximate the distribution of length of stay. Also, these models are proposed as the foundation of more sophisticated models designed to include the internal and external factors associated with LoS. In this context, the thesis proposes three different approaches to explore such factors: individual-based approach, group-based approach and multilevel group-based approach. These interrelated approaches allow a better understanding of the diversity in the patient population and enable length of stay predictions for individual patients, and for cohorts of patients within and between hospitals. In addition, this research is built and evaluated using data from all types of patients treated at two public hospitals operating in Mexico. It is the consideration of the full case-mix of these healthcare facilities that gives this research its unique nature
Crystal structure of zeolite omega, the synthetic counterpart of the natural zeolite mazzite
No full textRietveld refinement of the structure of synthetic zeolite omega \Na(6.6)TMA(1.8)(H2O)(22.2)\[Al8.4Si27.6O72]-MAZ, using high-resolution X-ray powder diffraction data, by Rietveld method, provided the missing evidence that this material has the same framework type (MAZ) as the natural mazzite. Its real symmetry is P6(3)/mmc, the same as the topological one, where a = 18.215 Angstrom, c = 7.634 Angstrom. TMA molecules are located inside the gmelinite cage, with two possible orientations, which are symmetric with respect to the plane passing through the center and orthogonal to the threefold axis of the cage. Sodium cations are distributed over two sites: one, at the center of the 8-ring channel, hosts most of Na and is 8-fold coordinated to six framework oxygens and two water molecules, while the other, located along the axis of the 12-ring channel, coordinates nine H2
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Thermal activation of NH4 precursor of acidic omega zeolite: A neutron and in-situ synchrotron powder diffraction combined study
No full textFor the first time, the real-time thermal activation of the NH4-omega zeolite (NH4-omega) was investigated through in situ synchrotron X-ray powder diffraction combined with neutron diffraction. The experimental approach allowed to study the precursor thermal behaviour upon heating, continuously monitoring the evolution of its structural features determined by NH4 ions and TMA calcination and dehydration processes. The activation of the precursor (H-omega sample) is fully reached at ⁓600 °C, when all the NH4 content has been released, dehydration mostly occurred and TMA degradation completed. From a structural point of view, Rietveld structural refinements highlighted relevant structural changes. In particular variations in intertetrahedral angles allowed to make hypothesis about the possible distribution of Brønsted acid sites on the framework oxygen atoms. The hypothesis was corroborated through the neutron Rietveld refinement of the deuterated and calcined omega (D-omega sample) that revealed the presence of two acid sites: D1 and D2 located on O5 and O2 framework oxygen atoms, respectively. Besides, neutron data confirmed the strong relation among framework and Brønsted acid sites geometry and short- and/or long-range interactions. In summary, non-conventional sources were successfully used to probe both activation and formation of acidic sites in omega precursor as well as determine the number and location of Brønsted sites in the deuterated omega
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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