1,720,978 research outputs found
Calving Ease Risk Factors and Subsequent Survival, Fertility and Milk Production in Italian Holstein Cows
Full text linkThe objectives of this study were to investigate the main risk factors associated with calving ease (CE) in Italian Holstein cow herds, and to estimate the association between CE and subsequent survival, fertility and milk production. Data obtained from Holstein cows in 40 Italian herds were retrospectively investigated. Calvings were surveilled and classified into two categories of CE, unassisted calving or assisted calving, based on the need for intervention. The following factors were analyzed as possible risk factor affecting CE: herd, number of calvings/herd/year, age at first calving (AFC), cow parity, gestation length, twinning, calf sex, previous calving-to-conception interval, previous milk yield, dry period and close-up length, and season of calving. The association between CE and culling risk within the first 30 days-in-milk (DIM), cumulative 60-d milk yield and predicted 305-d milk yield, and pregnancy risk within 150 DIM were also investigated. Of the 47,672 calvings, 37,892 (79.5%) were unassisted, while 9780 (20.5%) required some type of assistance. Among the risk factors, only the AFC was not correlated with CE, while for all the other risk factors an association with CE was detected. Assisted calvings were associated with an increased culling risk at 30 DIM, decreased 60-d milk yield, decreased 305-d milk yield and reduced pregnancy risk at 150 DIM. In conclusion, dairy herd management should aim at correcting/reducing the risk factors in order to limit the incidence of assisted calving, and possibly improve the quality of calving assistance; controlling CE within the herd is crucial to reducing culling risk, and achieving higher lactation and reproductive performance
Selected metabolic and hormonal profiles during maintenance of spontaneous ovarian cysts in dairy cows
No full textInformation is lacking regarding the relationship between metabolic and hormonal profiles and the maintenance of spontaneous ovarian cyst disease in dairy cows. For this reason, the concentrations of non-esterified fatty acids (NEFA), insulin-like growth factor I (IGF-I) and cortisol (coffee) were investigated during the spontaneous course of ovarian cyst disease in dairy cows (n = 6) between the 7th and 16th weeks post-partum (PP). The control group consisted of normally cycling cows (n = 6). Blood samples were collected twice a day, and plasma was analysed using different techniques. Progesterone and 15-ketodihydro-PGF(2 alpha) plasma profiles were investigated to confirm the ovulatory or anovulatory conditions of the cows. Cortisol plasma levels were not significantly different among sampling times within each group or between the two groups. NEFA plasma levels were significantly higher in cycling cows compared to cystic cows at the 16th week PP (p < 0.01), but with rather low values, indicating by now sparse mobilization of fat stores. Insulin-like growth factor I plasma concentrations were higher in cystic cows during the 8th, 10th, 11th (p < 0.01) and 16th week PP (p < 0.05), indicating that the presence of ovarian cysts coincides with increased IGF-I levels. These results suggest no influence of cortisol and NEFA levels in cysts maintenance, while a possible involvement of IGF-I can be suspected not only in the pathogenesis, as already known, but also in the maintenance of spontaneous cystic ovarian disease in cattle
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
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
Case Report: Reproductive evaluation of a Murgese stallion with obstructive azoospermia, accumulation of hyaline material in the ampullae ducts, and corpora amylacea in vesicular glands
Full text linkThis report aims to present a case of obstructive azoospermia in a stud stallion diagnosed with an alkaline phosphatase (SPAP) assessment. A 20-year-old Murgese stallion is referred for acquired azoospermia. History is negative for reproductive disorders, and clinical examinations and ultrasonography of internal and external genitalia do not reveal significant alterations. Semen collection highlights the absence of spermatozoa in the ejaculate and the urinalysis is negative for spermatozoa. SPAP assay is performed on seminal plasma, with a value of 30 IU/L, compatible with obstructive azoospermia. A biopsy is performed, detecting the presence of complete germ lines in both testes. A resolution is attempted endoscopically, gently insufflating ampullae, with negative results, so the stallion is excluded from breeding. Time afterwards, the stallion dies of natural causes, and necropsy and histopathological analyses are performed. Corpora amylacea are highlighted in both seminal vesicles; the right and left ampullae show ectasic lumen, with the diffuse presence of hyaline material. Ampullae obstruction is an uncommon pathology, which can affect stallions and jacks, generally caused by the accumulation of spermatozoa, but, unfortunately, this case was unresponsive to attempted treatments. Interestingly, to the authors’ knowledge, this is the first report of corpora amylacea in equine stallion sexual glands
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
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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