1,720,967 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
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
Genetic markers and explosive leg-muscle strength in elite Italian soccer players
No full textAim. The aim of the present paper was to investigate the relationships between polymorphisms in ACTN3, ACE and BDKRB2 genes, soccer performance, and explosive leg-muscle strength in Italian soccer players. Methods. We examined 42 top-level Italian soccer players (S) and 106 sedentary healthly Italians, as a control group (C). Χ 2 test was used to look for the difference in genotype distribution of ACTN3, ACE and BDKRB2 between groups. The data were evaluated by forward stepwise multiple regression analysis with the Squat Jump (SJ) and Counter Movement Jump (CMJ) as dependent variables, as well as competition level (CL), ACTN-3, ACE and BDKRB2 genotypes as independent variables. Results. No significant difference was found between groups for ACE, ACTN-3 and BDKRB2 genotype distributions. Forward stepwise multiple regression analysis suggests a significant relationship between a) SJ νs. CL, ACE, and ACTN-3 and b) CMJ νs. CL. For SJ, the multivariate model combining genotypic data and competition level significantly predicted explosive leg-muscle strength in soccer players and variance explained by the function was 23.92%. Conclusion. An interaction of two polymorphisms (ACE and ACTN-3) might be able to discriminate quantitative traits crucial for the elite soccer performance, however the contribution of genetic factors to soccer performance is not so high
Sampling strategies in a linguistic isolate: results from mtDNA analysis
No full textObjectives: Sampling strategies are crucial issues in population genetics and anthropological studies. The sampling choice is related to the research question and the type of markers used. In this research, we compared two different sampling strategies in the Sardinian linguistic isolate of Carloforte (Italy). Methods: A first sampling (N = 49) was carried out through grandparents criterion: individuals selected for the study were born and resident in Carloforte, and unrelated for at least three generations. A second sampling (N = 50) was based on founders surnames (FS): selected participants were proved to be descendants of the village founders, and to have no ancestors in common, at least up to the grandparental generation. Results: The group selected through FS showed a greater gene diversity, which was confirmed by both network and haplogroup analysis. Among the shared haplogroups, we find clear differences in their frequencies. Sampling through grandparents criterion showed essentially the same haplogroups found in Sardinia, and with similar frequencies. Interesting results came from genetic tree. The FS sampling clustered with Northern African populations and it is located very far from Italian and Sardinian populations, whereas the grandparents criterion sampling clustered with Italian populations and it is located close to the other Sardinian populations. Conclusions: Results showed that different sampling strategies can lead to contrasting results. As sampling through grandparents criterion is influenced by recent gene flow, we hypothesize that the difference observed with the two sampling strategies is due to the merging of Carloforte with Sardinian populations
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
Angiotensin-converting enzyme gene does not contribute to genetic predisposition to elite soccer’s performance in Italians
No full textAim. The purpose of this study was to verify the association between the ACE l/D polymorphism and elite athletes status in Italian soccer players. Methods. DNA was extracted from each participant using buccal swab. We determined the genotype and allele frequencies of ACE l/D polymorphism in a group of 26 top-level male soccer players. Their results were compared with those of 85 unrelated sedentary Italian healthy men (controls). Finally, we quantify the relationship between ACE l/D polymorphism and some performance variables of lower limb strenght measured with counter movement jump (CMJ) and squat jump (SJ) and 20 m sprint (10 m plusl 0 m). Results. The results of our preliminary study showed that ACE genotypes and allele frequencies amongst soccer players (DD, ID, II=0.50,0.40,0.10, respectively; D allele=0.70) were not significantly different from Italian sedentary controls (DD, ID, II=0.46,0.41,0.13, respectively; D allele = 0.66; x2=0.64, df=2, P=0.72). It is noteworthly that, the frequencies of our control group were similar to those observed in other Italian sedentary subjects and different to those of general Caucasian population reported by other authors in different association studies. Furthmore, the analysis of variance showed no significant difference between athletes with different genotypes and muscle strenght tests: SJ (cm DD, ID, II = 41.6, 42.5, 43.2, respectively; F2,20=0.14, P=0.86); CMJ (cm DD, ID, II = 43.1, 44.5, 45.8, respectively; F2-20=0.52, P=0.59); 20 m Sprint (s DD, ID, H = 4.07, 4.08, 4.08, respectively; F2,20=0.008, P=0.99). Conclusion. The present research clearly suggest that ethnic origin should be carefully considered in the increasing number of studies on the association between ACE l/D polymorphism and elite athletes performance. These results suggest the lack of association between ACE l/D polymorphism and elite soccer's performance in Italians
Influence of MCT1 A1470T Polymorphism on Muscle Injuries Among Elite Italian Soccer Players
No full textACTN-3 and ACE genotypes in elite male Italian athletes
Full text linkThe ACE I/D and the ACTN-3 R577X polymorphisms are the most studied genes associated with elite athlete status, even if this association has been often conflicting. The aim of the present study was to investigate the association between the ACE and the ACTN3 genotypes and elite performance in Italian male athletes. The ACTN-3 R577X and the ACE I/D genotype distributions of 59 elite male Italian athletes practicing gymnastics (G; n = 17), 100 m-400 m running (R; n = 12), and playing soccer (S; n= 30) were compared with controls from Italian (C; n = 31) populations. For ACE distribution, athletes did not differ from controls (G, X2 = 0.37, df = 2, p = 0.82; R, X2 = 1.90, df = 2, p = 0.45; S, X2 = 1.48, df = 2, p = 0.47) and the DD genotype was at very high frequency in all groups (G = 53%, R= 50%, S = 60%, C = 45%). For ACTN-3 distribution, elite gymnasts showed a significant difference from controls (X2 = 6.57, df = 2, p = 0.03), showing an absence of XX genotype. Soccer players and runners did not differ from controls in ACTN-3 genotype distribution (R, X2 =0.43, df = 2, p = 0.80; S, X 2 = 1.25, df = 2, p = 0.53). Even if the ACE DD genotype is often positively associated with elite sprint/power athlete status, its high frequency in Italian populations eliminates the possibility of its exclusive association in Italian athletes. The results of ACTN3 genotypes suggest that RR genotype of ACTN-3 gene is a determinant of elite gymnasts status but it is not the key factor for achieving a top-level performance in soccer or track events
Polymorphisms in TAS2R38 and the taste bud trophic factor, gustin gene co-operate in modulating PROP taste phenotype
No full textThe PROP taste phenotype varies greatly among individuals, influencing eating behavior and therefore may
play a role in body composition. This variation is associated with polymorphisms in the bitter receptor gene
TAS2R38 and the taste-bud trophic factor gustin gene. The aim of this study was to examine the relationship
between TAS2R38 haplotypes and the gustin gene polymorphism rs2274333 in modulating PROP taste
phenotype. PROP phenotype was determined in seventy-six volunteers (29 males, 47 females, age 25±3 y)
by scaling methods and threshold measurements. TAS2R38 and gustin gene genotyping was performed using
PCR techniques. The lowest responsiveness in PROP nontasters is strongly associated with the AVI nontasting
TAS2R38 variant and the highest responsiveness in supertasters is strongly associated to allele A and genotype
AA of the gustin gene. These data support the hypothesis that the greater sensitivity of supertasters could be
mediated by a greater taste-bud density. Polymorphisms in TAS2R38 and gustin gene, together, accounted for
up to 60% of the phenotypic variance in PROP bitterness and to 40% in threshold values. These data, suggest
that other unidentified factors may bemore relevant for detecting low concentrations of PROP. Moreover, the
presence of the PAV variant receptor may be important for detecting high concentrations of PROP, whereas
the presence of allele A in gustin polymorphism may be relevant for perceiving low concentrations. These data
show how the combination of the TAS2R38 and gustin gene genotypes modulate PROP phenotype, providing
an additional tool for the evaluation of human eating behavior and nutritional statu
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