1,721,037 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
Presence of serum antibodies anti-benzo(a)pyrenediol epoxide (BPDE-DNA) and tobacco smoking as predictors of respiratory outcomes
No full textBackground: BPDE-DNA were cross-sectionally associated with active smoking in a large general population sample (Petruzzelli, 1998).
Aim: to assess interaction between smoking and BPDE-DNA as predictor of respiratory outcomes over a 18-year follow-up.
Methods: n=750 subjects from two population-based studies in Pisa, Italy, were investigated at baseline (PI1 1991-93) and follow-up (PI2 2009-11) through a questionnaire on health status and risk factors, spirometry and blood analyses. Subjects were classified as: class 1, positive BPDE-DNA heavy smokers (≥ 12 cig./day - population median value); class 2, positive BPDE-DNA light smokers (< 12 cig./day); class 3, negative BPDE-DNA smokers; class 4, ex/never smokers (reference category). Multiple logistic regression models, adjusted for sex and age, estimated the risk of respiratory outcomes at follow-up among the considered classes.
Results: there were 4.3%, 2.5%, and 22.8% of subjects in class 1, 2, and 3, respectively. BPDE-DNA positivity per se was not significantly related to any outcomes. Class 1 showed significantly higher risks of developing COPD (OR 4.53 CI 1.84-11.16), asthma attacks (OR 3.48 CI 1.28-9.47), and dyspnoea (OR 2.47 CI 1.06-5.75), while class 2 was not related to any outcome. Higher risks for developing respiratory symptoms/diseases were found also in class 3 but with lower ORs than in class 1.
Conclusions: BPDE-DNA along with smoking may predict poor respiratory outcomes, particularly respiratory diseases/symptoms in heavier smokers
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
Active and passive tobacco smoking
No full textDespite reduction in prevalence of active smoking since 1980, the absolute number of smokers
has increased worldwide from 718 to 967 million in 2012. In Europe, the prevalence of
smoking in 2012 ranged from 13% to 40%, with higher values in south and east. Trends in
smoking-related mortality and morbidity follow changes in prevalence; control of smoking
prevents premature death and smoking cessation is associated with longer life. Research on the
relationship between smoking and health is still in progress: 10 new diseases causally linked to
active smoking were introduced in the 2014 US Surgeon General’s Report, along with
enhanced causality for TB and idiopathic pulmonary fibrosis. There is no safe level of exposure
to passive smoking. Authoritative health organisations agree that passive smoking exposure
leads to serious and fatal diseases, including cardiovascular and respiratory diseases, and
cancers. Children, including fetuses and newborns, can develop health effects from exposure.
About 35% of nonsmokers are exposed worldwide to passive smoking at home, at work and in
public places
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
Il diagramma proporzionale di Venn delle malattie ostruttive del polmone nella popolazione generale italiana
No full textObiettivi dello studio: Il diagramma di Venn delle malattie ostruttive del polmone è stato recentemente
quantificato. Abbiamo puntato a quantificare la proporzione della popolazione generale
affetta da malattie croniche ostruttive del polmone e le combinazioni di asma, bronchite
cronica (BC) ed enfisema, diagnosticate dal medico in due campioni di popolazione generale
italiana, in rapporto all’ostruzione del flusso aereo (OA) determinata con la spirometria.
Disegno di studio e partecipanti: Abbiamo analizzato i dati derivanti da due studi prospettici
(4353 pazienti) condotti nell’area rurale del Delta del Po dal 1988 al 1991 e nell’area urbana di
Pisa dal 1991 al 1993.
Risultati: Le prevalenze di asma, BC ed enfisema sono state 5,3, 1,5 e 1,2% nel Delta del Po, e
6,5, 2,5 e 3,6% a Pisa. Un doppio diagramma di Venn, usato per quantificare la distribuzione di
BC, enfisema ed asma, in relazione alla presenza/assenza di OA, ha identificato 15 categorie.
OA isolata è stata la categoria più frequente (11,0% nel Delta del Po e 6,7% a Pisa), seguita da
asma sola senza OA (3,3 e 4,3%, rispettivamente). La combinazione delle tre condizioni OLD è
stata la sola categoria che ha sempre mostrato prevalenze più elevate per quelli con OA (0,20%
nel Delta del Po e 0,16% a Pisa) piuttosto che per quelli senza (0,04 e 0,05%). Tra coloro con
OLD od OA, il 61,4% nel Delta del Po ed il 38,2% a Pisa avevano OA isolata, il 24,8% ed il
41,9% OLD senza OA, ed il 13,8% ed il 19,9% presenza simultanea di OLD ed OA. In ambedue
i sessi la frequenza di asma da sola diminuiva con l’età, mentre quella di OA isolata, BC-enfisema
e la combinazione di asma e BC-enfisema aumentava.
Conclusioni: Circa il 18% dei campioni della popolazione generale italiana ha riportato OLD o
ha mostrato segni spirometrici di OA. I nostri dati confermano che il diagramma di Venn delle
OLD può essere quantificato nella popolazione generale estendendo le categorie di malattie
mutuamente esclusive (includendo diagnosi concomitanti di asma, bronchite cronica o enfisema)
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Epidemiologia della broncopneumopatia cronico-ostruttiva: fattori di rischio ambientali ed occupazionali [Epidemiology of the chronic obstructive pulmonary disease: Environmental and occupational risk factors]
No full textLa Broncopneumopatia Cronica Ostruttiva
(BPCO) costituisce un’importante causa di morbilità e
mortalità nei paesi industrializzati ed in via di sviluppo.
Secondo stime dell’Organizzazione Mondiale della Sanità
(OMS), nel 2020, la BPCO diverrà la terza causa di morte nel
mondo.
Ad oggi, sono stati studiati numerosi fattori di rischio
predisponenti allo sviluppo della BPCO. Questi possono agire
singolarmente od interagire tra loro in maniera sinergica. Il
fumo di tabacco e l’età avanzata sono i maggiori determinanti
implicati nello sviluppo ed esacerbazione della BPCO, ma sono
di grande importanza anche i fattori ambientali, come
l’inquinamento atmosferico e l’esposizione occupazionale.
Raccomandazioni per la prevenzione della BPCO sono quindi,
oltre alla promozione della cessazione dell’abitudine al fumo, il
controllo dell’esposizione professionale e l’abbattimento
dell’inquinamento atmosferico. Alla luce del trend storico di
esposizione ai fattori di rischio, ulteriori ricerche
epidemiologiche sono necessarie per una più approfondita
conoscenza della storia naturale della BPCO
Definition, epidemiology and natural history of COPD
No full textChronic obstructive pulmonary disease (COPD) is the fifth cause of morbidity and
mortality in the developed world and represents a substantial economic and social burden.
Patients experience a progressive deterioration up to end-stage COPD, characterised by very
severe airflow limitation, severely limited and declining performance status with chronic
respiratory failure, advanced age, multiple comorbidities and severe systemic manifestations/
complications.
COPD is frequently underdiagnosed and under-treated. Today, COPD develops earlier in life
and is less gender specific. Tobacco smoking is the major risk factor for COPD, followed by
occupation and air pollution. Severe deficiency for a1-antitrypsin is rare; several phenotypes are
being associated with elevated risk for COPD in the presence of risk factor exposure. Any patient
presenting with cough, sputum production or dyspnoea should be assessed by standardised
spirometry. Continued exposure to noxious agents promotes a more rapid decline in lung function
and increases the risk for repeated exacerbations, eventually leading to end-stage disease.
Without major efforts in prevention, there will be an increasing proportion of end-stage patients
who can live longer through long-term oxygen therapy and assisted ventilation, but with elevated
suffering and huge costs. Smoking prevention and smoking cessation are the most important
epidemiological measurements to counteract chronic obstructive pulmonary disease epidemic
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
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