1,720,979 research outputs found
Variazione dei tassi di decomposizione del detrito vegetale e delle caratteristiche trofiche della comunita’ detritivora lungo un gradiente di urbanizzazione (Fiume Tevere- Roma-).
No full textDeveloping a multimetric index of ecological integrity based on macroinvertebrates of mountain ponds in central Italy.
No full textEvaluation of timing of re-appearance of VBNC Legionella for risk assessment in hospital water distribution systems
Full text linkBackground. In this study we estimated the presence of Legionella species, viable but non-culturable (VBNC),
in hospital water networks. We also evaluated the time and load of Legionella appearance in samples found
negative using the standard culture method.
Methods. A total of 42 samples was obtained from the tap water of five hospital buildings. The samples
were tested for Legionella by the standard culture method and were monitored for up to 12 months for the
appearance of VBNC Legionella.
Results. All the 42 samples were negative at the time of collection. Seven of the 42 samples (17.0%) became
positive for Legionella at different times of monitoring. The time to the appearance of VBNC Legionella was
extremely variable, from 15 days to 9 months from sampling. The most frequent Legionella species observed
were Legionella spp and L. anisa and only in one sample L. pneumophila srg.1.
Conclusion. Our study confirms the presence of VBNC Legionella in samples resulting negative using the
standard culture method and highlights the different time to its appearance that can occur several months
after sampling. The results are important for risk assessment and risk management of engineered water
systems
Short-term exposure to PM2.5 and risk of venous thromboembolism. A case-crossover study
No full textBackground: Short-term exposure to air pollution increases the risk of cardiovascular mortality and morbidity but little evidence is available on pollution effects on venous thromboembolism (VTE), a common vascular disease. Methods: We conducted a case-crossover analysis of all urgent hospitalizations for deep vein thrombosis (DVT) or pulmonary embolism (PE) among patients >35 years during the period 2006 to 2017 in Rome (Italy). We examined whether 1) short-term exposure to particulate matter with aerodynamic diameter <2.5 μg (PM2.5) increases the risk of hospitalization for DVT or PE, and 2) if the associations are modified by the period of the year (warm and cold seasons), sex, age and comorbidity. Results: We found that short-term exposure to PM2.5 was associated with an increase of PE hospitalization risk of during the warm season (April to September) of 19.6% (95% confidence intervals: 8.3, 31%) per 10 μg/m3, while no statistically significant effects were displayed during the cold season or the whole year or for DVT hospitalizations. The effect of PM2.5 remained significant (%change: 21.3; 95%CI: 5.4, 39.5) after adjustment for nitrogen dioxide (NO2) co-exposure (a marker of traffic sources) and when limiting to primary diagnosis of PE (%change: 19.1; 95%CI: 4.2, 36.1). Age, sex and comorbid conditions did not modify the association. Conclusions: Our results suggested a positive association between short-term exposure to PM2.5 and pulmonary embolism during the warm period of the year while no evidence emerged for deep vein thrombosis
A cohort study on long-Term exposure to air pollution and incidence of liver cirrhosis
Full text linkBackground: Cirrhosis is an advanced liver disease affecting millions of people worldwide, involving high healthcare costs. Despite experimental evidence suggesting a possible role of airborne pollutants in liver diseases, epidemiological studies are lacking. We aimed at investigating the association between exposure to air pollutants and incidence of cirrhosis in a large population-based cohort in Rome. Methods: We used an administrative cohort established from the 2001 census. We included all adults of 30 years of age or older who were free of cirrhosis, resulting in a study population of over 1.2 million subjects. Follow-up of the subjects ended on 31 December 2015. We ascertained incident cases of cirrhosis from regional mortality and hospital discharge registries using a validated algorithm. We assessed exposure of the subjects to PM10, PM coarse, PM2.5, PM2.5absorbance, NO2, NOx, and PM metal components at their residential address using Land Use Regression models. We used Cox regression models, adjusted for relevant covariates, to estimate the association between air pollution exposure and cirrhosis incidence. Results: We observed 10,111 incident cases of cirrhosis, with a crude incidence rate of 67 × 100,000 person-years. Long-Term exposure to all pollutants tested was significantly associated with cirrhosis, e.g., PM10(hazard ratios [HR], 1.05; 95% confidence interval [CI], 1.01-1.09, per 10 μg/m3increments), PM coarse (HR, 1.11; 95% CI, 1.05-1.17, per 10 μg/m3increments), PM2.5(HR, 1.08; 95% CI, 1.03-1.13, per 5 μg/m3increments), and NO2(HR, 1.03; 95% CI, 1.02-1.05, per 10 μg/m3increments). The associations were robust in secondary analyses. Conclusions: Our findings suggest a possible contribution of air pollution to the development of cirrhosis
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
- …
