1,720,996 research outputs found
Amyotrophic lateral sclerosis descriptive epidemiology: The origin of geographic difference
Full text linkAmyotrophic lateral sclerosis (ALS) epidemiology has rapidly developed in the last 30 years alongside the evolving changes in concepts in the field of clinical ALS and also due to the recent proposals of new classification system for motor neuron diseases. Many of these changes in the clinical scenario have been determined through the results of ALS population-based studies conducted in the last 20 years primarily in Europe. All the evidences converge to show that ALS risk is different across continents and ethnicities. In a European registry consortium named EURALS, ALS incident cases were drawn from a source population comprising almost 24 million people across Europe (ALS cases: 1028) and the estimated incidence was 2.2 per 100,000 person- years (py) for the general population. In contrast, other population-based studies have measured the lowest incidence in East Asia to be 0.89 per 100,000 py and in South Asia to be 0.79 per 100,000 py. A large part of Africa, Latin America and Asia does not have any population-based studies. The origin of geographic difference in ALS incidence is a matter of debate. Probably, this is partly due to genes (C9ORF72) and partly due to environmental risk factors. The rapid disappearance of ALS Foci in Guam, Kii, and West Guinea underline the importance of changes in lifestyle and environmental factors. The Global Burden of Disease, a project aiming to describe the burden of all diseases and injuries across all the countries of the world with a standardized protocol, has collected heterogeneous sources of data to estimate the burden of motor neuron diseases. The demographic changes related to increased expectation of life and the growth of the world population indicate that the load of motor neuron disease is rapidly moving toward 400 thousand prevalent cases. The burden is expected to shift toward Asia and Africa in the next decades for the rapid increase of expectation of life of countries with high demographic impact. (c) 2019 S. Karger AG, Base
The Reconstructed Cohort Design: A Method to Study Rare Neurodegenerative Diseases in Population-Based Settings
Full text linkRare neurodegenerative diseases are characterized by high heterogeneity and high clinical complexity, as well as low incidence and prevalence, thus making tracking small numbers of incident cases in the general population very challenging. Since it is not possible to use classical cohort studies to estimate the incidence of these rare diseases, we can "reconstruct" a theoretical cohort using case information from a well-defined geographic region collected through a surveillance system. The incidence rate is estimated as the ratio between the number of individuals at risk who were diagnosed with the disease of interest during the study period and the estimated overall amount of time individuals in the reference population spent at risk during the study period. If a series of assumptions are met, the approximate incidence proportion of a closed theoretical cohort without competing events and with the same follow-up duration can be calculated by multiplying the incidence rate with the length of the study time. This rationale relies on the presence of an effective referral system, which links all levels of the healthcare system together in the region, from general practitioners to specialized clinical centers. The reconstructed cohort design is a valid and cost-effective method to collect data on the incidence of rare neurodegenerative diseases and represents the theoretical framework for building up population-based registries
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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