1,720,986 research outputs found
Sperm aneuploidies and low progressive motility
No full textBACKGROUND:
Patients with poor semen quality show increased sperm disomy and diploidy rates. Oligozoospermia and teratozoospermia are known to influence sperm aneuploidy, but there is still a debate about whether aneuploidies are associated with reduced motility.
METHODS:
Ejaculates from a large group of patients were examined by light microscopy to evaluate sperm concentration, motility and morphology, and by fluorescence in-situ hybridization (FISH) to analyse the presence of aneuploidies. Statistical analysis was performed to compare differences and to evaluate the relationship between sperm aneuploidy rate and semen quality.
RESULTS:
Five groups were established following the motility parameter, and total aneuploidy rates were statistically significantly higher in the groups where motility was <30% compared to the controls. A homogeneous group of men with asthenozoospermia showed higher FISH values compared to control data, although the difference was not statistically significant. Motility and sperm morphology were each found to be statistically related to aneuploidy using a multiple linear regression analysis, whereas sperm concentration was only related to aneuploidy by the equation of a hyperbolic curve.
CONCLUSIONS:
In conclusion, biological and statistical data from the present research support the idea that the presence of aneuploidies could also be associated with reduced sperm motility
L'attività conoscitiva, di indirizzo e di controllo del Parlamento in relazione al PNRR
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
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
BMI from nutritional surveillance of 8-9 years old children in Tuscany (Italy)
Full text linkIntroduction. The latest increase in childhood obesity focused attention on the important consequences that this phenomenon may have on public health in relationship to the increasing risk that an obese child may become an obese adult. To deal with this problem, there is necessary to assess systematically the distribution of childhood nutritional status at different levels: international, regional and local. In this paper are presented data on underweight, overweight and obesity prevalence in third grade primary school children, aged 8/9 years in Tuscany (2008) and its distribution in relationship to the demographic breadth of their place of residence. Methods. Data from statistic sample of 2109 (1.091 males, 1.018 females), 8/9 years school-children were collected; weight and height were measured using standardised personnel and instruments. Exact month age was calculated between the data of measurement and that of birth. Body Mass Index (BMI) classes were calculated using Cole et al.'s epidemiologic cut-off for children and adolescents. Residence areas were divided into four classes based on the number of inhabitants ([removed] 50.000; > 50.000 metropolitan). Results. The prevalence of underweight was 0.88% (0.76% in males and 1.01% in females), the prevalence of overweight was 23.43% (22.33% in males and 24.65% in females), the prevalence of obese was 7.95% (9.08% in males, 6.70% in females). The lowest prevalence of obese (6.46%) was found in towns with over 50.000 residents (metropolitan). Conclusion. The obesity prevalence in Tuscany children is still lower than that of the Italian National Survey, while the overweight prevalence it's the same. Obesity prevalence (10.71%) is higher in municipalities with low residents number (< 10.000)
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
Underweight and overweight among children and adolescents in Tuscany (Italy). Prevalence and short-term trends
Full text linkIntroduction. The recent increase in both childhood obesity and adolescent anorexia nervosa in developed countries has underlined the important consequences that these trends may have on public health, as there is an increased risk that these conditions may become chronic diseases in adulthood. Therefore, it is necessary to monitor prevalence rates and trends in thinness and overweight (including obesity) among children and adolescents at different levels: international, national and sub-national. Since 2001/2002, a nutritional surveillance system has been implemented in the Tuscany Region to estimate the nutritional status and lifestyles of children and adolescents. The main objectives were to assess the prevalence of thinness, overweight and obesity among Tuscan children and adolescents and to provide baseline information on the prevalence of thinness, for the first time calculated according to the new international definitions, for geographical comparisons and descriptions of time trends. Methods. Independent cross-sectional sample surveys were conducted in 2002, 2004 and 2006 in Tuscany, North-Central Italy. Data were collected from stratified two-stage cluster samples of children aged 9 years (n = 3,048 in 2002 and n = 1,430 in 2006) and of adolescents aged 11-13-15 years (n = 1,066, n = 1185 and n = 1,160 in 2004 and n = 1,189, n = 1,211 and n = 1,178 in 2006, respectively). Weights and heights of primary school children were measured by means of standardized methods, while those of adolescents were self-reported. Decimal age was calculated from the date of birth to the date of measurement. Body Mass Index classes were calculated according to the International Obesity Task Force standards. Instead of the term underweight in children, we used the term thinness, which the World Health Organization uses to mean low Body Mass Index for age in adults and adolescents. According to Cole 's recently published cut-offs for thinness, we divided our Body Mass Index values below 18.5 into three grades. Results. This study presents data on the prevalence of different grades of nutritional status (thinness, normal weight, overweight and obesity) among Tuscan school-aged children from primary to high school (9-11-13-15-y-old), assessed by means of Body Mass Index, according to international definitions. From 2002 to 2006 the prevalence of thinness among children aged 9 years decreased from 4.6% to 4.2%, and the prevalence of normal weight from 63.7% to 62.4%; the prevalence of overweight (including obesity) rose from 31.7% to 33.4%. From 2004 to 2006, among pre-adolescents aged 11 years, the prevalence of thinness declined from 11.0% to 10.1%; the prevalence of normal weight rose from 68.4% to 70.2%, and the prevalence of overweight declined from 20.7% to 19.6%. Among adolescents aged 13 years, the prevalence of thinness declined from 9.8% to 8.0%; the prevalence of normal weight rose from 73.5% to 74.0%, and the prevalence of overweight from 16.8% to 17.9%. Among adolescents aged 15 years, the prevalence of thinness declined from 9.8% to 8.7%, and the prevalence of normal weight from 77.0% to 71.6%, while the prevalence of overweight rose from 13.3% to 19.7%. The 2006 data showed that the trend in the prevalence of overweight (including obesity) tended to decrease with age for both sexes, though more markedly in girls (from 34.0% at 9-y of age to 12.2% at 15-y of age) than in boys (from 32.8% at 9-y of age to 22.8% at 13-y of age to 27.5% at 15-y of age). By contrast, the prevalence of thinness increased with age in girls (from 4.9% at 9-y of age to 14,1% at 15-y of age), while boys presented a similar low prevalence at 9 and 15-y of age (3.3% and 3.1%), doubling the values at 11 and 13-y of age (7.5% and 6.5%). The trend in the prevalence of normal weight increased with age from 62.4% at 9-y of age to 74.0% at 13-y of age and to 71.6% at 15-y of age. Boys displayed a higher prevalence than girls only at 9-y of age (63.9% vs. 61.0%). Discussion. The results of this study allow us to analyze data from the nutritional surveillance system in Tuscany using recent definitions of Body Mass Index cut-off points among children, pre-adolescents and adolescents. As a rule, the trend in the prevalence of overweight (including obesity) among girls from 9-y to 15-y-old strongly decreased, while the prevalence of thinness increased. In boys, this decrease was less marked and the prevalence of thinness displayed an irregular trend, with an increment from 9-y to 11-y-old and a decrease from 13-y to 15-y old. The trend in the prevalence of normal weight increased with age, with a higher prevalence among boys than girls
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