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Infant growth and body composition from birth to 24 months: are infants developing the same?
No full textA good start to life is critical to offset later risks including lower school achievement, reduced adult income, non-communicable disease susceptibility, and intergenerational risk [1]. Growth failure and/or rapid weight gain in early life is also associated with an array of adverse health effects in later life [2–4]. The WHO growth standards have provided better means of interpreting length and weight assessments independent of where the child is born. Along with normative data for foetal growth [5], the child growth standards form part of recent advances in monitoring child development. Normative data for body composition have been described as the next logical level of advancement [6]. The multicenter infant body composition reference study (MIBCRS) has come close to achieving this by developing reference charts for body composition using a multi-ethnic sample, to represent a suitable reference for body composition gain [7]. Data from the MIBCRS emphasise the important role of context [8], home environment and feeding practices [9] in shaping body composition. However, the performance of body composition relative to ideal growth, which is the gold standard for assessing child development in both clinical and epidemiological settings, remains unclear. While anthropometric measurements may provide better reproducibility and are easy to obtain, body composition assessments may provide a more precise picture of the biological response to the interplay of genetic, nutrition, and environmental effects than measures of body size. A better understanding of infant body composition patterns in addition to linear growth may present possible intervention opportunities to reduce the obesity risk in infancy and childhood, and possibly offset the risk of non-communicable disease in adulthood. Therefore, our aim was to investigate longitudinal sex and country differences in infant body composition relative to ideal growth in six countries under conditions that are more likely to facilitate improved linear growth. We hypothesised that children born to mothers selected accordingly to the WHO MGRS [10] will track the WHO growth standards median and have similar FMI and FFMI during infancy irrespective of which country they were born in
Body composition from birth to 2 years
No full textProviding all infants with the best start to life is a universal but challenging goal for the global community. Historically, the size and shape of infants, quantified by anthropometry and commencing with birthweight, has been the common yardstick for physical growth and development. Anthropometry has long been considered a proxy for nutritional status during infancy when, under ideal circumstances, changes in size and shape are most rapid. Developed from data collected in the Multicentre Growth Reference Study (MGRS), WHO Child Growth Standards for healthy infants and children have been widely accepted and progressively adopted. In contrast, and somewhat surprisingly, much less is understood about the ‘quality’ of growth as reflected by body composition during infancy. Recent advances in body composition assessment, including the more widespread use of air displacement plethysmography (ADP) across the first months of life, have contributed to a progressive increase in our knowledge and understanding of growth and development. Along with stable isotope approaches, most commonly the deuterium dilution (DD) technique, the criterion measure of total body water (TBW), our ability to quantify lean and fat tissue using a two-compartment model, has been greatly enhanced. However, until now, global reference charts for the body composition of healthy infants have been lacking. This paper details some of the historical challenges associated with the assessment of body composition across the first two years of life, and references the logical next steps in growth assessments, including reference charts
Infant growth and body composition from birth to 24 months: are infants developing the same?
No full textBackground: given the importance of infancy for establishing growth trajectories, with later-life health consequences, we investigated longitudinal body composition among infants from six economically and ethnically diverse countries. Methods: we recruited mother-infant dyads using the WHO Multicenter Growth Reference Study criteria. We measured fat-free mass (FFM) in 1393 (49% female) infants from birth to 6 months of age (Australia, India, and South Africa; n = 468), 3–24 months of age (Brazil, Pakistan, South Africa, and Sri Lanka; n = 925), and derived fat mass (FM), fat mass index (FMI), and fat-free mass index (FFMI). Height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length (WHZ) Z-scores were computed. Sex differences were assessed using a t-test, and country differences using a one-way analysis of covariance. We further compared subsamples of children with average (−0.25 > HAZ < +0.25), below-average (≤−0.25) and above-average (≥+0.25) HAZ.Results: HAZ performed well between 0 and 6 months, but less so between 3 and 24 months. The stunting prevalence peaked at 10.3% for boys and 7.8% for girls, at 24 months. By 24 months, girls had greater FMI (10%) than boys. There were significant differences in FFM (both sexes in all countries) and FM (Brazilian boys, Pakistani and South African girls) by 24 months of age between infants with average, above-average, and below-average HAZ. Conclusion: in a multi-country sample representing more ideal maternal conditions, body composition was heterogeneous even among infants who exhibited ideal length. Having a mean HAZ close to the median of the WHO standard for length reduced FFM between-country heterogeneity but not FM, suggesting that other factors may influence adiposity.</p
Anthropometric prediction models of body composition in 3 to 24month old infants: a multicenter international study
No full textBackground: accurate assessment of body composition during infancy is an important marker of early growth. This study aimed to develop anthropometric models to predict body composition in 3–24-month-old infants from diverse socioeconomic settings and ethnic groups.Methods: an observational, longitudinal, prospective, multi-country study of infants from 3 to 24 months with body composition assessed at three monthly intervals using deuterium dilution (DD) and anthropometry. Linear mixed modelling was utilized to generate sex-specific fat mass (FM) and fat-free mass (FFM) prediction equations, using length(m), weight-for-length (kg/m), triceps and subscapular skinfolds and South Asian ethnicity as variables. The study sample consisted of 1896 (942 measurements from 310 girls) training data sets, 941 (441 measurements from 154 girls) validation data sets of 3–24 months from Brazil, Pakistan, South Africa and Sri Lanka. The external validation group (test) comprised 349 measurements from 250 (185 from 124 girls) infants 3–6 months of age from South Africa, Australia and India.Results: sex-specific equations for three age categories (3–9 months; 10–18 months; 19–24 months) were developed, validated on same population and externally validated. Root mean squared error (RMSE) was similar between training, validation and test data for assessment of FM and FFM in boys and in girls. RMSPE and mean absolute percentage error (MAPE) were higher in validation compared to test data for predicting FM, however, in the assessment of FFM, both measures were lower in validation data. RMSE for test data from South Africa (M/F−0.46/0.45 kg) showed good agreement with validation data for assessment of FFM compared to Australia (M/F−0.51/0.33 kg) and India(M/F−0.77/0.80 kg).Conclusions: anthropometry-based FFM prediction equations provide acceptable results. Assessments based on equations developed on similar populations are more applicable than those developed from a different population
Body composition of infants at 6 months of age using a 3-compartment model
No full textBackground/objectives: two compartment (2 C) models of body composition, including Air Displacement Plethysmography (ADP) and Deuterium Dilution (DD), assume constant composition of fat-free mass (FFM), while 3-compartment (3 C) model overcomes some of these assumptions; studies are limited in infants. The objective of the present study is to compare 3 C estimates of body composition in 6-mo. old infants from Australia, India, and South Africa, including FFM density and hydration, compare with published literature and to evaluate agreement of body composition estimates from ADP and DD.Methods: body volume and water were measured in 176 healthy infants using ADP and DD. 3C-model estimates of fat mass (FM), FFM and its composition were calculated, compared between countries (age and sex adjusted) and with published literature. Agreement between estimates from ADP and DD were compared by Bland–Altman and correlation analyses.Results: South African infants had significantly higher % FM (11.5%) and density of FFM compared to Australian infants. Australian infants had significantly higher % FFM (74.7 ± 4.4%) compared to South African infants (71.4 ± 5.0) and higher FFMI (12.7 ± 0.8 kg/m2) compared to South African (12.3 ± 1.2 kg/m2) and Indian infants (11.9 ± 1.0 kg/m2). FFM composition of present study differed significantly from literature. Pooled three country estimates of FM and FFM were comparable between ADP and DD; mean difference of −0.05 (95% CI: −0.64, +0.55) kg and +0.05 (95% CI: −0.55, +0.64) kg.Conclusions: 3C-model estimates of body composition in infants differed between countries; future studies are needed to confirm these findings and investigate causes for the differences
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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