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Piglet birth weight and litter uniformity : importance of pre-mating nutritional and metabolic conditions
No full text High piglet birth weights and litter uniformity are important for piglet survival and piglet performance. Within-litter variation in piglet birth weight is the consequence of within-litter variation in early embryo development, which in turn reflects variation in follicle and oocyte development. Insulin-stimulating diets before mating can influence litter development and uniformity, probably through beneficial effects of insulin on IGF-1 and follicle development. The first aim of this thesis, therefore, was to study effects of insulin-stimulating diets during the weaning-to-estrus interval (WEI) on plasma insulin and IGF-1 levels and follicle development, and consequences for embryo, fetal and placental development and uniformity at different stages of pregnancy in sows. Results of this thesis show that plasma insulin levels during WEI can be effectively enhanced by dietary sugars as dextrose and sucrose (high peaks directly after feeding) and starch (enhanced insulin levels at ~4h after feeding) in a dose-dependent manner. Follicle development and subsequent litter uniformity of embryos (at day 10 of pregnancy) or fetuses and placentas (at day 42 of pregnancy), however, were not affected by insulin-stimulating diets during WEI, nor related to plasma insulin and IGF-1 levels during WEI. Besides effects of pre-mating diets, plasma insulin and IGF-1 levels and follicle development are also influenced by the pre-mating metabolic state of the sow: in sows with severe body condition loss during lactation, plasma insulin and IGF-1 levels and follicle development at weaning are suppressed, and restoration of plasma insulin and IGF-1 levels and follicle development occurs in sows with a prolonged lactation or a prolonged weaning-to-pregnancy interval (WPI). The second aim of this thesis, therefore, was to study effects of these pre-mating conditions related to sow metabolic state on subsequent piglet birth weight and litter uniformity. In this thesis it is shown for the first time that pre-mating conditions related to sow metabolic state affect subsequent litter uniformity. Litter uniformity at birth was compromised by severe sow body condition loss during previous lactation and improved in sows with a prolonged WPI. Furthermore, it was shown that in (organic) sows with prolonged lactations (6 weeks) and large litters (17.4±0.3 piglets), insulin-stimulating diets before mating did not result in improved piglet birth weights or litter uniformity. This may be related to a restored follicle development at weaning in these sows. In these large organic litters, piglet birth weight and litter uniformity were strongly related to piglet survival during lactation. To conclude, results of this thesis confirm that litter uniformity at birth is already (partly) determined during the pre-mating period, likely related to (insufficient) restoration of follicle development. In contrast to previous studies, insulin-stimulating diets during WEI did not improve litter uniformity of embryos, fetuses or placentas and/or piglets in sows. The role of plasma IGF-1 levels and follicle development at weaning (both related to sow parity and sow body condition loss), and effects of insulin-stimulating diets during lactation, need further study. Finally, although effects of pre-mating nutritional and metabolic conditions on subsequent piglet birth weight and litter uniformity seem only marginal, these marginal effects can have substantial effects on pre-weaning piglet survival.</p
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
Voer van invloed op biggensterfte
No full textMarginale verschillen in voeding en metabolisme vóór inseminatie kunnen leiden tot grote verschillen in prenatale en postnatale biggensterfte. Dit was een van de conclusies tijdens het seminar van de leerstoelgroep Adaptatiefysiologie in Wageningen University
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
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