1,721,095 research outputs found
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
Rilevazioni dell'Inquinamento atmosferico da elementi in tracce nella Toscana Meridionale mediante il lichene Parmelia caperata (L.) Ach.
No full textConcentrations of major elements and mercury in unstimulated human saliva
No full textThe aim of this study was a preliminary assessment of a possible role of human saliva in the diagnosis of some physiological and pathological changes in oral and body functions. Reliable procedures for collection and analysis of samples were established in order to assess total concentrations of Ca, K, Mg, Na, P, and Hg in whole unstimulated saliva. Possible relationships between element concentrations and sex, age, smoking, illness conditions, or side effects resulting from the use of drugs were investigated. The effects of stimulated or unstimulated collection procedures, dental prosthesis, and amalgam fillings were also evaluated. Total concentrations of major cations and Hg in whole saliva from 33 healthy adults living in the Siena district showed a coefficient of variation ranging from 11% (P) to 53% (Na) and average values were in the same range of those previously reported for unstimulated saliva. Healthy males had significantly higher concentrations of K, Na, P, and Na/K, Na/Ca, Na/Mg, and Na/P values than females. Age, smoking, dental prosthesis, and amalgam fillings had no significant effects on the concentrations of major elements. On the contrary, concentrations of Hg were positively correlated to the number of amalgam fillings and increased at a rate of about 1.9 microg/L for each filling. No correlations were found between Hg concentrations and those of major elements. Comparisons with literature data showed a different composition (particularly for Na and Hg concentrations) between unstimulated and stimulated saliva. Samples from patients affected by idiopathic pulmonary fibrosis had significantly higher concentrations of K and the maximum value was measured in a patient affected by acute pulmonary edema. This increase was likely the result of pharmacological treatments with tricyclic antidepressants and/or saline solutions. Data reported in this study, although preliminary, contribute to the assessment of levels of major cations (some of them very little investigated) and Hg in whole unstimulated human saliva and provides consistent support for further research on the possible use of this easy accessible matrix as a diagnostic tool of body function change
I cittadini e il sistema sanitario: c'è bisogno di fiducia?
No full textObiettivi. La fiducia negli altri ha una grande rilevanza nella vita economica, politica e sociale di un paese: infatti, laddove la fiducia reciproca è elevata, la società funziona meglio, è più produttiva, più cooperativa, più coesa, meno diffusi sono i comportamenti opportunistici e più ridotto è il livello della corruzione. Alla luce dei dati più recenti, ci proponiamo di indagare la fiducia come componente fondamentale della cura, che si costruisce nel tempo attraverso i contatti ripetuti tra il cittadino e i servizi sanitari.
Metodi. Sono stati analizzati i principali studi nazionali-internazionali che dal 2003 ad oggi hanno posto al centro il tema della fiducia dei cittadini nelle istituzioni sociali, sanitarie e in maniera più dettagliata si sono interrogati sulla fiducia dopo un’esperienza di cura.
Risultati. La proporzione di italiani che ha fiducia nei confronti delle istituzioni sociali (54%) risulta essere una delle più basse tra i paesi dell’area OECD, mostrando una forbice di disuguaglianza tra centro Nord e Sud dell’Italia (41,3% vs 26,3%).
Risulta, invece, largamente apprezzata la professionalità e la competenza di medici e infermieri per il 64,2% degli intervistati. Aumenta inoltre la percentuale degli italiani soddisfatti del Servizio Sanitario Nazionale se si chiede di esprimersi sulla base dell’esperienza diretta e non secondo una generica opinione.
Conclusioni. La fiducia è un valore che richiede alle istituzioni di vigilare sull’equilibrio fragile tra delega e valutazione, in particolare valorizzando le buone pratiche e la comunicazione trasparente dei dati, indagando l’esperienza dei pazienti e creando una partnership tra tutti gli attori coinvolti. Ulteriori approfondimenti sono necessari per comprendere quali siano i più efficaci metodi di costruzione di partnership all’interno delle organizzazioni sanitarie
Propensity score for the analysis of observatonal data. An introduction and an illustrative examle
No full textThe principal aim of analysis of any sample of data is to draw causal inferences about the effects of different exposures, such as decisions, actions, medical treatments, or other interventions on relevant outcomes. Data may be the result of several kinds of study designs and approaches, either experimental or observational. In experimental, comparative intervention studies, randomization of patients guarantees that the groups are comparable before the exposure to the treatments and random assignment assures that the choice for a given treatment is not due to the decision by treating physicians and also allows a correct application of statistical tests. In observational studies when randomization is not used for practical or ethical reasons, treatments are decided by physicians (or by patients, or by both) in the context of the best clinical practice and, thus, groups are not comparable and differences in outcomes may reflect either effects caused by the treatment choices or differences in prognosis before treatment. When differences between groups are observed or expected, different kinds of adjustments are used to statistically adjust for the unbalance, using variables describing the condition of patients before treatment. Usually, potential predictive and/or prognostic variables are used together to adjust for confounding by constructing multivariable models. This approach is most of the time able to reduce the effect of confounders or effect modifiers on relevant outcomes, but it makes it difficult for investigators and for final users of the results to assess the adequacy of the approach, the role and impact of each class of variables, and, eventually, the clinical meaning of the results. In 1983, Rosenbaum and Rubin proposed a new method, named Propensity Score, to balance the variables related to the choice of the exposure (treatments) in order to reconstruct a situation similar to random assignment. Since then, there has been an explosion of examples of the use of this approach in the literature. This report introduces the method, uses an empirical example to illustrate its use, and eventually discusses the pros and cons of the method using the authors’ experience and some hints extracted from recent commentaries
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
Dietary fiber and stomach cancer risk: a case-control study from Italy
No full textFiber intake has been inversely related to stomach cancer risk, although this issue is still controversial. A case-control study was conducted in Italy between 1997 and 2007, including 230 cases with incident, histologically confirmed stomach cancer, and 547 controls with acute, non-neoplastic diseases. Dietary habits were investigated through a validated food frequency questionnaire. Compared with the lowest quintile of intake, the multivariate odds ratios (ORs, including terms for major recognised confounding factors and total energy intake) for the highest quintile were 0.47 (95% confidence interval (CI): 0.28-0.79) for total fiber, 0.50 (95% CI: 0.30-0.85) for soluble non-cellulose polysaccharides (NCP), 0.39 (95% CI: 0.23-0.66) for total insoluble fiber, 0.54 (95% CI: 0.32-0.91) for insoluble NCP, 0.37 (95% CI: 0.22-0.64) for cellulose, and 0.59 (95% CI: 0.36-0.98) for lignin. With reference to the sources of fiber, an inverse association was found for fiber from vegetable (OR = 0.42, 95% CI: 0.24-0.72), and to a lesser extent from fruit (OR = 0.65, 95% CI: 0.38-1.10), but not for fiber from grain (OR = 1.25, 95% CI: 0.77-2.03). This study found an inverse relationship between stomach cancer risk and various types of fiber, derived, in particular, from vegetables and fruit
- …
