1,721,055 research outputs found
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
Influence of milking units and working vacuum level on the mechanical milking of goats
No full textThe objectives of this study were to evaluate and compare the effect of working vacuum levels (35 and 44 kPa) and liners dimensions (mouthpiece lip diameter and overall length, 20–185 and 22–170 mm) on the main milking characteristics of goats. The results highlight that both the working vacuum level and the liner dimension have influenced the milk flow curve parameters. The maximum variations were found for peak flow rate, which increased significantly with liner dimensions of 20–185 mm at a working vacuum level of 44 kPa as well as average milk flow rate and for plateau phase duration. The incorrect adoption of operative parameters and unsuitable milking machine components, might affect the performance of the mechanical milking and negatively affecting animal productions and welfare
Effect of body weight and growth in early life on the reproductive performances of Holstein heifers
Full text linkIn Italy most dairy cows produce milk for cheese manufacture and are farmed in inten-sive systems, with free stall barns, milking parlor or robotic milking, total mixed ration and no (or limited) access to pasture. The main objective for farmers is to maximize farm income and mini-mize farm costs by adopting strategies and ‘best practices’ in the early life of heifers. Monitoring body weight (BW) and fertility of young stock is fundamental to ensure good performances in future dairy cows and to enhance farm profit. In this study BW (kg) and average daily gain (ADG, kg/d) recorded at different stages in early life of 382 Holstein calves were used to estimate associations with fertility traits. Data consisted of BW at birth (BW0), three BWs (BW1, BW2, and BW3) recorded in three phases of calf’s early life, ADG in the three phases (ADGI, ADGII, and ADGIII), ADG of the entire period (ADGI-III), number of services per pregnancy (NS), and age at first calving (AFC). As expected, the four BWs were positively correlated to each. In general, heavier calves were characterized by better fertility compared to lighter calves. Monitoring BW and ADG in re-placement heifers starting from the early age is recommended to improve NS and AFC at farm level and could be useful to set up genetic improvement programs. Future studies will benefit from the addition of milk-related traits and the increase of sample size (number of farms)
Prediction of sheep bulk milk coagulation properties from mid-infrared spectral data
Full text linkThe technological features of milk are essential for cheese manufacturing. This is particularly true for Italy, where most of the milk produced by sheep is intended for cheese production. The possibility to evaluate technological characteristics and coagulation aptitude of milk in advance, before any treatment, is crucial for decision-making at industry level. In the present study, we tested the ability of mid-infrared spectroscopy for prediction of coagulation traits (rennet coagulation time and curd firmness) by using more than 4000 bulk milk samples of 344 sheep herds. The models developed with a partial least square regression showed that spectral data points can be successfully used to predict the two traits. The coefficient of determination in external validation was 0.42 for rennet coagulation time and 0.28 for curd firmness, indicating that sheep milk delivered to dairies can undergo a preliminary screening only to assess the expected coagulation time. This finding will allow manufacturers to evaluate the milk received from farmers. Further investigation will be need to improve the prediction of rennet coagulation time that can be coupled with composition traits to define premiums or penalties in the payment system
Portable milkmeters for the rapid in-field collection of milkability phenotypes in dairy goats
Full text linkThe present study aimed to investigate the phenotypic factors affecting the variability of the milkability traits measured in Italian dairy goats through a portable milkmeter in commercial herds. Milkability descriptors combine either milk production, milking time, or milk flow and are important to consider for reasons related to udder health, e.g., they can be exploited for large- or small-scale monitoring of mechanical milking stress. The milkability traits recorded in this study were analyzed through a linear model. Almost all the traits were influenced by lactation stage, but only part of them were affected by parity and season of sampling. With exception of blind phase (overmilking indicator), estimates decreased along the lactation, suggesting that fresh animals – especially pluriparous – are those with the greatest productivity, milk emission flow, and milking time. As regards the effect of parity, for the majority of traits the estimates of primiparous were lower compared to those of pluriparous. Monitoring milking ability of goats through milkmeters in the field can be a strategy to evaluate milking procedures of farmers and could thereby boost the implementation and effectiveness of udder health improvement schemes with positive implications on milk quality and farm profitability
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
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