1,720,961 research outputs found
Postpartum Ovarian Function in Dairy Cattle
Get PDFTo achieve the economic target of one calf a year, a cow must be pregnant by 85 days postpartum and is essential for maximum milk production. Resumption of ovarian activity and repro were investigated in ten normally calving cows from each of three breeds of cattle - Friesian, Jersey x LO and Friesian x Sahiwal. Visual observations, a teaser bull and tail painting wer detection. Rectal palpatian was conducted once weekly between 17 and 70 days postpartum and laparoscopic examination waw performed at least once during the experimental period to monitor ovarian changes. Samples
of blood plasma were collected twice weekly during the same period from all cows and assayed for plasma progesterone using a radioimmunoassay. The non-detected aestrus, pregnancy and early embryonic mortality. A plasma progesterone concentration of 1 ng/ml or greater was used as the criterion for luteal activity. Intervals and standard deviations from parturition to first ovulation and first detected oestrus were 23 + 6.5 and 62 ± 25.9 days
for Friesian, 29 + 9.9 and 33 ± 11.5 days for Jersey x LD and 48 + 29.1 and 59 ± 21.9 days for Friesian x Sahiwal cows. Interval from calving to the first postpartum ovulation and oestrus among three breeds were significantly different (p < 0.05). The interval from parturition to uterine involution for Friesian, Jersey x LD and Friesian x
sahiwal were 35 ± 1.2, 33 ± 4.1 and 30 ± 2 days respectively (p> 0005). Only 52 percent of all cows were detected in oestrus at the commencement of the first aestrous cycle. The mean plasma progesterone concentration
during detected oestrus was 0.23 ± 0.16 ng/ml and at 21 days for pregnant cows was 3.01 Z 0.89 ng/ml. Average plasma progesterone levels during oestrous cycle were highest in Friesian cows, moderate in Jersey x LD and lowest in Friesian x Sahiwal cows. Only one case of early embryonic death was recorded. Cystic ovaries were observed
in 4 out of 10 Friesian cows. Sixty percent of Jersey x LD and 50 percent of Friesian x Sahiwal had conceived about day 85 postpartum. However, none of the Friesian cows had conceived by this time. The infertility in the Friesian cows were an oestrus, non-detected oestrus and repeat breeding which extended the calving interval beyond the
optimum interval. The results confirm that Bos taurus x Bos indicus dairy breeds have a better reproductive performance than a Bos taurus breed in a tropical environment
Bioactivity of Insuline Like Growth Factor-1 (IGF-1) Derived From The Hepatocyte Monolayer Culture Against Cleavage and Development of Bovine Embryo In Vitro
Get PDFLiver cells (hepatocyte) have an ability to produce IGF-1 through monolayer culture, but their concentration and the bioactivity against cleavage and development of embryo were not clear. The purpose of this study was to nalyze cell number and IGF-1 concentration derived from hepatocyte monolayer culture and test their bioactivity against cleavage and development of bovine embryos in vitro. Hepatocyte culture was prepared by grinding liver tissues followed by trypsination and repeatedly centrifugation to obtain hepatocytes. They were then cultured in TCM199 + FCS 10% + BSA 10%, and then incubated in ncubator C 5% CO2 at 38.5° for 3, 6, 9 and 12 days. IGF-1 concentration after culture was measured by IRMA technique. The results of hepatocyte monolayer culture showed that 6-day incubation period resulted in the most confluent liver cells and IGF-l at the highest concentration compared with other incubation periods.
Bioactivity test of IGF-1 in this research was carried out by adding the supplement media in the in vitro fertilization and development media of ovine embryos by observating and counting a number of embryos which nderwent leavage (2-8 cell) in the day 2 after fertilization and embryos developing into morula stage on the day 6. The results of research showed media urnished with supplement media/liquid from the hepatocyte monolayer culture containing IGF-1 in fact produced the highest number of embryos undergoing cleavage and developing into morula stage compared with the use of media without supplementation. In conclusion, the IGF-l can be produced through bovine hepatocyte monolayer culture and it is found to increase cleavage rate and bovine embryo development in vitro
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
- …
