1,721,154 research outputs found
The relationship among circulating insulin-like growth factor (IGF)-I, IGF-binding proteins-1 and -2, and birth anthropometry: a prospective study
No full textFetal IGF-I is a determinant of birth weight, but whether maternal IGF-I plays a significant role is controversial. We sought to examine the relationships among maternal IGF-I, IGF-binding protein (IGFBP)-1, and IGFBP-2, with maternal and newborn anthropometry, in a cohort of 325 nondiabetic pregnant women of African origin. Blood was collected for IGF-I, IGFBP-1, and IGFBP-2 at 9, 25, and 35 wk gestation and in cord blood at delivery.In the second and third trimesters, maternal IGF-I was significantly correlated (P < 0.005) with maternal body mass index and triceps skinfold thickness. Maternal IGFBP-1 and -2 had an inverse correlation (P < 0.0001), with maternal anthropometry. Maternal IGF-I at 35 wk, and fetal IGF-I by cord blood were significantly correlated with birth weight (P = 0.001 and 0.048, respectively). IGFBP-1 in the third trimester and cord blood were negatively correlated with birth weight (P = 0.012 and 0.002). In multiple regression analyses, maternal IGF-I at 35 wk, fetal IGF-I, maternal weight at the first antenatal visit, gender, and gestational age were significant independent factors in the determination of birth weight. In conclusion, maternal IGF-I levels, especially during late pregnancy, positively influence birth weight
Growth, body composition, and the onset of puberty: longitudinal observations in Afro-Caribbean children
No full textContext: childhood growth and body composition may influence the onset of puberty.Objective: ee examined the effects of birth size, growth rates throughout childhood, and body composition on the onset of puberty in Afro-Caribbean children.Design and setting: this was a longitudinal birth cohort study (the Vulnerable Windows Cohort Study) in Jamaica.Subjects and measurements: the anthropometry (weight, height, skinfold measurements, and waist circumference) of 259 children was measured at birth, at 6 wk, every 3 months to 2 yr, and then every 6 months. Tanner staging for puberty and orchidometry were performed every 6 months starting at approximately age 8 yr. Bioelectrical impedance was done at age 11 yr.Results: In the girls, thelarche, pubarche, and menarche occurred at median ages of 8.8, 9.9, and 12.0 yr, respectively. Pubarche in boys occurred at a median age of 11.3 yr when the median testicular volume was 2.8 ml. Faster weight gain during infancy (age 0–6 months) and childhood, but not birth size, was associated with more advanced puberty (P values <0.05). Fat mass at age 8 yr was associated with more advanced puberty (P values <0.001) in both sexes. At age 11 yr, lean mass, but not fat mass, was associated with more advanced puberty (P values <0.001).Conclusion: these data support the hypothesis that faster growth throughout childhood, especially with fat mass accretion, is associated with more advanced puberty apart from menarche. With the onset of puberty, lean mass accretion significantly increase
Non-alcoholic fatty liver disease in non-obese subjects of African origin has atypical metabolic characteristics
No full textBackground:
Non-obese non-alcoholic fatty liver disease (NAFLD) is reported in several populations. However, as persons of African origin display unique fat accumulation, insulin resistance and lipid profiles, we investigated fatty liver in non-obese persons of African origin.
Method:
We recruited 78 urban Jamaican volunteers. CT scan was used to estimate liver and abdominal fat; body composition by D-EXA. Fasting blood was collected for lipids, alanine aminotransferase (ALT), adiponectin and fetuin-A. Homeostatic model assessment of insulin resistance (HOMA), whole body insulin sensitivity index (WBISI), insulinogenic index (IGI) and oral disposition index (oDI) were calculated after a 75-g oral glucose tolerance test.
Results:
52% of the participants were male; mean age 28.5±7.8 years and BMI 22.4±3.0 kg/m2 (±SDs). Mean liver attenuation (MLA) and liver: spleen (LS) ratio, both inversely correlated to liver fat, were 62.8±4.3 HU and 1.2±0.1 respectively, and 3.8% of the participants had liver fat >30% (LS ratio<1). In age, sex and BMI-adjusted correlations, MLA was negatively associated with weight (r=-0.30, p=0.009) and height (r=-0.28, p=0.017) and associated with fasting glucose (r=0.23, p=0.05), fasting insulin (r=0.42, p ≤ 0.001) and HOMA-IR (r=0.35, p=0.004). Serum lipids, ALT, adiponectin, fetuin A, WBISI, IGI and oDI were not associated with liver fat.
Conclusions:
In non-obese Afro-Caribbean participants, greater liver fat (lower MLA) was associated with weight and height and lower fasting insulin. Hyperinsulinaemia appears to be influential in the reduction of NAFLD in this group. These findings may be influenced by ethnicity, body size and the method of estimating liver fat
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
A genome-wide search replicates evidence of a quantitative trait locus for circulating angiotensisn l-converting enzyme (ACE) unlinked to the ACE gene
Full text linkBackground: angiotensin I-converting enzyme (ACE) plays an important role in cardiovascular homeostasis. There is evidence from different ethnic groups that circulating ACE levels are influenced by a quantitative trait locus (QTL) at the ACE gene on chromosome 17. The finding of significant residual familial correlations in different ethnic groups, after accounting for this QTL, and the finding of support for linkage to a locus on chromosome 4 in Mexican-American families strongly suggest that there may well be QTLs for ACE unlinked to the ACE gene.Methods: a genome-wide panel of microsatellite markers, and a panel of biallelic polymorphisms in the ACE gene were typed in Nigerian families. Single locus models with fixed parameters were used to test for linkage to circulating ACE with and without adjustment for the effects of the ACE gene polymorphisms.Results: strong evidence was found for D17S2193 (Zmax = 3.5); other nearby markers on chromosome 17 also showed modest support. After adjustment for the effects of the ACE gene locus, evidence of "suggestive linkage" to circulating ACE was found for D4S1629 (Zmax = 2.2); this marker is very close to a locus previously shown to be linked to circulating ACE levels in Mexican-American families.Conclusion: in this report we have provided further support for the notion that there are QTLs for ACE unlinked to the ACE gene; our findings for chromosome 4, which appear to replicate the findings of a previous independent study, should be considered strong grounds for a more detailed examination of this region in the search for genes/variants which influence ACE levels.
The poor yields, thus far, in defining the genetic determinants of hypertension risk suggest a need to look beyond simple relationships between genotypes and the ultimate phenotype. In addition to incorporating information on important environmental exposures, a better understanding of the factors which influence the building blocks of the blood pressure homeostatic network is also required. Detailed studies of the genetic determinants of ACE, an important component of the renin-angiotensin system, have the potential to contribute to this strategic objectiv
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
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