1,720,959 research outputs found
Relationship between mammary gland infections and some milk immune parameters in Sardinian breed ewes
Over the last few years an increased rate of intramammary infections caused by environmental and opportunistic pathogens has been observed in sheep farms. The presence of these microorganisms is mainly related to poor conditions of environmental hygiene and/or to decreased defenses of the mammary gland. The work we present here is a part of a project on the immune status of ewe mammary gland and its influence on mastitis development. In this paper, we have studied how intramammary infections caused by opportunistic pathogens reflect on immune parameters in ewe milk. Milk samples collected monthly before the morning milking, were screened for the presence of microorganisms and tested for somatic cell counts (SCC), polymorphonuclear neutrophil leukocytes (PMN), phagocytic activity, lysozyme content, and NAGase activity. Data showed that phagocytic activity was significantly higher in bacteriologically negative udders (156 mV/1000 PMNs) than in infected udders (10 mV/1000 PMNs). These results suggest that intramammary infection might be associated with a decrease of mammary gland immune status
Isolamento di Actinobacillus lignieresii da ascessi superficiali in un allevamento di capre sarde
Correlazione tra infezioni mammarie da stafilococci coagulasi negativi, contenuto in cellule somatiche e produzione di latte in pecore di razza sarda
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Effects of intramammary infections on somatic cell score and milk yield in Sarda sheep
AIM: To evaluate the effects of intramammary infections (IMI) on somatic cell score (SCS) and milk yield in dairy ewes. METHODS: Monthly milk samples were collected from a flock of 202 Sarda sheep, over a period of 7months, for bacteriological culture and measurement of somatic cell counts (SCC). During the same period, milk yield was measured daily using electronic milk meters connected to each half-udder cluster of the milking machine. SCC was transformed to SCS using a base-2 log transformation. One SCS is equivalent to a SCC of 25,000cells/ml, and each increase of 1 in SCS is associated with doubling of the SCC. IMI was defined by the presence of five or more colonies of similar morphology isolated from a milk sample (epsilon 500cfu/ml). The effect of IMI on SCS and milk yield was assessed using a generalised estimating equation (GEE). RESULTS: There were 1,186 udder halves with IMI from 2,828 milk samples, a prevalence of 41.9%. The distribution of bacterial species within the 1,186 culture-positive samples was comprised of 476 (40.1%) Staphylococcus epidermidis, 172 (14.5%) Staph. chromogenes, 38 (3.2%) Staph. caprae, 134 (11.3%) Staph. simulans, 114 (9.6%) Streptococcus uberis, 123 (10.4%) Strep. dysgalactiae, and 129 (10.9%) Strep. equi subsp. zooepidemicus. SCS was greater in udder halves with IMI (mean 7.71; SD 0.82) than in udder halves without IMI (mean 5.53; SD 1.02) (p0.01). IMI due to streptococcal species were associated with greater SCS (mean 8.24; SD 0.62) than those due to staphylococcal species (mean 7.48; SD 0.79) (p0.01). Milk yield from udder halves with IMI was lower (mean 439 (SD 162) ml/half udder/day) than from udder halves without IMI (mean 602 (SD 170) ml/half udder/day) (p0.01). IMI due to staphylococcal species was associated with a lower milk yield (mean 399 (SD 167) ml/half udder/day) than IMI due to streptococcal species (mean 427 (SD 156) ml/half udder/day) (p0.01). CONCLUSIONS: These findings provide sheep milk producers with information on the losses associated with subclinical mastitis, which can be used to evaluate the economics of prevention and treatment protocols concerning udder health in ovine dairy flocks
Dispelling the Myths Behind First-author Citation Counts
We 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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