1,721,030 research outputs found
Debunking Rumors in Networks
Full text linkWe study the diffusion of a true and a false message (the rumor) in a social
network. Upon hearing a message, individuals may believe it, disbelieve it, or
debunk it through costly verification. Whenever the truth survives in steady
state, so does the rumor. Communication intensity in itself is irrelevant for
relative rumor prevalence, and the effect of homophily depends on the exact
verification process and equilibrium verification rates. Our model highlights
that successful policies in the fight against rumors increase individuals'
incentives to verify
Optimal Verification of Rumors in Networks
Full text linkWe study the diffusion of a true and a false message when agents are biased and able to verify messages. As a recipient of a rumor who verifies it becomes informed of the truth, a higher rumor prevalence can increase the prevalence of the truth. We uncover conditions such that this happens and discuss policy implications. Specifically, a planner aiming to maximize the prevalence of the truth should allow rumors to circulate if: verification overcomes ignorance of messages, transmission of information is relatively low, and the planner\u27s budget to induce verification is neither too low nor too high
Use of antidepressant medication in pregnancy and adverse neonatal outcomes: A population-based investigation
No full text
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
Is the Risk of Preterm Birth and Low Birth Weight Affected by the Use of Antidepressant Agents during Pregnancy? A Population-Based Investigation
Full text linkUntreated depression during pregnancy increases the risk of morbidity and mortality in the mother and child. Therefore, specific treatments are required for this population.The study aimed to investigating the effect of antidepressant medication used during pregnancy with reference to the risk of preterm birth (PTB) and low birth weight (LBW).A population-based study was carried out with data provided by the healthcare utilization database of Lombardy, an Italian region with about ten million inhabitants. The study included 384,673 births from 2005 to 2010. Maternal use of antidepressants before and during pregnancy was investigated. Log-binomial regression was used to estimate the association between the use of antidepressants during pregnancy, compared to the non-use or use just before pregnancy, and the prevalence ratio of PTB and LBW.Women who used antidepressants during pregnancy had a 20% (95% CI: 10-40%) increased prevalence of both PTB and LBW compared to those who never used antidepressants. There was no evidence that women who used antidepressants during pregnancy had a higher prevalence of the considered outcomes compared to women who used antidepressants before pregnancy, but stopped during pregnancy. Such findings were confirmed by considering separately the effects of SSRIs and other antidepressants together.Our findings suggest that depression in itself, rather than antidepressant medication, might be implicated in the causal pathway of PTB and LBW
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
Number of lung resections performed and long-term mortality rates of patients after lung cancer surgery: evidence from an Italian investigation
No full textOBJECTIVES: Although it has been postulated that patients might benefit from the centralization of high-volume specialized centres, conflicting results have been reported on the relationship between the number of lung resections performed and the long-term, all-cause mortality rates among patients who underwent surgery for lung cancer. A population-based observational study was performed to contribute to the ongoing debate.
METHODS: The 2613 patients, all residents of the Lombardy region (Italy), who underwent lung resection for lung cancer from 2012 to 2014 were entered into the cohort and were followed until 2018. The hospitals were classified according to the annual number of pulmonary resections performed. Three categories of lung resection cases were identified: low (<30), intermediate (31–95) and high (>95). The outcome of interest was all-cause death. A frailty model was used to estimate the death risk associated with the categories of numbers of lung resections performed, taking into account the multilevel structure of the data. A set of sensitivity analyses was performed to account for sources of systematic uncertainty.
RESULTS: The 1-year and 5-year survival rates of cohort members were 90% and 63%. Patients operated on in high-volume centres were on average younger and more often women. Compared to patients operated on in a low-volume centre, the mortality risk exhibited a significant, progressive reduction as the numbers of lung resections performed increased to intermediate (-13%; 95% confidence interval +10% to -31%) and high (-26%; 0% to -45%). Sensitivity analyses revealed that the association was consistent.
CONCLUSIONS: Further evidence that the volume of lung resection cases performed strongly affects the long-term survival of lung cancer patients has been supplied
Incidence, Predictors, and Clinical Implications of Discontinuing Therapy with Inhaled Long-Acting Bronchodilators among Patients with Chronic Obstructive Pulmonary Disease
No full textIncidence, predictors and effect of discontinuation of long-acting bronchodilators on the risk of death or hospital admission among adults with Chronic Obstructive Pulmonary Disease (COPD) were assessed in a large population-based prospective study carried out by linking Italian healthcare utilization databases. Specifically, the cohort of 17,490 beneficiaries of the National Health Service in the Italian Region of Lombardy, aged 40 years or older, who started long-acting bronchodilators therapy during 2005-2008 was followed from first dispensation until 2012. During this period, patients who experienced discontinuation of long-acting bronchodilators were identified. Hospitalizations for COPD and deaths for any cause (composite clinical outcome) were also identified during follow-up. A Cox proportional hazards model was fitted to identify predictors of discontinuation. The case-crossover design was used to assess the implications of treatment discontinuation on the clinical outcome risk. Cumulative incidences of discontinuation were, respectively, 67%, 80%, and 92% at 6 months, 1 year, and 5 years since initial treatment. Significant predictors of discontinuation were female gender, younger age, starting treatment with fixed-dose combination of inhaled bronchodilators and corticosteroids, using antibiotics, inhaled long-acting bronchodilators and corticosteroids and not using short-acting bronchodilators, other respiratory drugs and systemic corticosteroids during follow-up. Odds ratios (95% confidence intervals) for the clinical outcome associated with not discontinuing long-acting bronchodilators was 0.64 (0.50 to 0.82). In conclusion, in the real-life setting, discontinuation of inhaled long-acting bronchodilators in adults with COPD is high even after just 6 months, even though persistence to these drugs reduces the risk of severe outcomes
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