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Preterm birth has impact on the long term health of two generations
No full textResearch over the last decade has provided clear evidence that children and young adults born very preterm have reduced insulin sensitivity. There is very little data on the metabolic changes, changes in body composition and blood pressure beyond young adulthood in preterm survivors, particularly those born moderately preterm, who constitute the vast majority of preterm survivors. To date the impact of parent’s prematurity on the health of their children has not been assessed. This thesis reports glucose metabolism, body composition and blood pressure profile of a cohort of 52 adults (31 preterm, 21 term at mean GA of 33.3 and 39.8 weeks respectively) aged between 34-38 years and their 61 healthy, pre-pubertal, term born offspring (37 of preterm parents, 24 of term parents) aged 5-10 years. The adult cohort, both preterm and term born, were a subgroup of a much larger cohort involved in two previous studies- the Auckland Steroid Trial and The Steroid Follow-up study. Insulin secretion and insulin sensitivity were assessed using hyperglycaemic clamp in adults and frequently sampled intravenous glucose tolerance test in the offspring. Both the adults and their offspring had their body composition assessed using DXA scan and blood pressure measured using 24 hour ambulatory blood pressure monitor. In the Adult study, compared to those born at term, those born preterm had ~50% reduction in insulin sensitivity, but had appropriate compensatory hyperinsulinaemia. The preterm subjects, especially men, also had increased total and abdominal adiposity. Although the mean blood pressure between the two groups was similar, preterm subjects had greater variability of blood pressure profile. In the Offspring study, the offspring of preterm parents had similar insulin sensitivity and insulin secretion as the offspring of term parents but had increased total and abdominal adiposity. Although the mean blood pressure in both the offspring groups was similar, comparison with an international reference data showed subtle changes in blood pressure in the offspring of preterm parents. This study has confirmed and extended previous observations on preterm survivors. Reduction in insulin sensitivity occurs even in those with moderate prematurity (33 to 37 weeks) and this finding extends the potential group at risk of insulin resistance to up to 7% of the population. Our findings of increased adiposity and blood pressure changes suggest an increased risk of later adult diseases in those born preterm. This is the first study assessing the health of children born to preterm parents. We speculate that the increased adiposity observed in the offspring of preterm parents may reflect transmission of an epigenetically modified phenotype from their preterm parent. In conclusion, preterm birth has effects over at least 2 generations and the public health impact of prematurity may be larger than previously thought
Fetal origins hypothesis in twin children : a metabolic evaluation
No full textWhole document restricted, but available by request, use the feedback form to request access.This thesis explores whether low birth weight affects glucose homeostasis and other aspects of the metabolic syndrome in twin children. The key parameter studied is insulin resistance, and whether insulin resistance is also associated with abnormalities in blood pressure or other aspects of the metabolic syndrome. This thesis is a comparison of twins to singletons, rather than being a study of these traits within twin pairs.
The fetal origins hypothesis suggests that low birth weight ultimately is associated with adult onset diseases namely coronary heart disease, glucose intolerance and hypertension. All twins to a degree are born prematurely and with low birth weight. It is unclear whether their metabolism in later life reflects this, or alternatively reflects their uniqueness as twins irrespective of birth weight. This thesis reviews how adaptation for their unique fetal life has affected in particular, glucose homeostasis in twins.
Insulin resistance has been consistently identified prior to the onset of both type 2 diabetes mellitus and hypertension and is also the primary metabolic abnormality persisting from programming of the undernourished fetus. Both small-for-gestational-age and prematurely born infants are insulin resistant when examined in mid-childhood. It has been postulated that this represents an attempt of the fetus to salvage itself from a state of inadequate nutrition. Twins when examined in this thesis are also shown to be insulin resistant, or to have a reduction in insulin sensitivity. This insulin resistance was independent of low birth weight and prematurity, and reflected a unique twin effect.
Examing blood pressure precisely revealed that twins had increased night-time blood pressure, a feature also seen in a variety of pre-hypertensive states. However, there was no association between low birth weight and any 24 hour blood pressure monitoring parameter in twins. Twins also had elevated leptin levels but reduced TNF-alpha levels in twins irrespective of birth weight or prematurity.
Twins have unique metabolic profiles which are not correlated with low birth weight, and twins should be considered an exception to the fetal origins hypothesis
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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