1,720,996 research outputs found
Associations between exposure to bovine herpesvirus 1 (BoHV-1) and milk production, reproductive performance, and mortality in Irish dairy herds
Get PDFpeer-reviewedAs cost-benefit analyses are required to prioritize and promote disease control and eradication programs within a jurisdiction, national data relating to disease-related production losses are particularly useful. The objectives of the current study were to use Irish bovine herpesvirus 1 (BoHV-1) prevalence data in dairy herds, obtained by bulk milk sampling on 4 occasions over the 2009 lactation, to document associations between milk production, fertility performance, mortality, and BoHV-1 herd status. Bulk milk (n = 305) antibody ELISA was used to classify farms as positive or negative in terms of endemic BoHV-1. Cow-level (milk parameters only) and herd-level performance data were sourced from the Irish Cattle Breeding Federation. Ordinary linear and negative binomial regressions were used to investigate associations between milk, fertility, and mortality performance and herd-level BoHV-1 results (both categorical and continuous variables). Only slight effects on the rates of carryover cows, nonpregnant cows, and total deaths were highlighted with increasing ELISA sample/positive (%) values (incidence rate ratio = 1.001). Multiparous cows in herds BoHV-1 bulk milk antibody positive recorded a reduction in milk yield per cow per year of 250.9 L in the multivariable linear model. Milk fat and protein yields were also affected by herd BoHV-1 status, again highlighting sub-optimal milk production in BoHV-1 bulk milk-positive herds. The current study has highlighted an economical method of investigating losses due to endemic infection using repeated bulk milk sampling over a single lactation. These data can contribute to analyzing the cost-benefit of applying BoHV-1 control strategies both on farm and at a national level
Development of on-farm diagnostic devices
Get PDFThe global population, currently 7.7 billion, is expected to grow to 9.7 billion by 2050. This is expected to lead to a 70% increase in demand for animal-based protein. Irish beef and dairy products account for over 50% of our agricultural output and DAFM’s Food Wise 2025 strategy aims to position Ireland as a world leader in sustainable agri-food production. However, the high percentage of livestock that are lost due to infectious diseases (20%), poses a challenge to achieving this sustainability, in addition to more sustainable use of antimicrobials, smarter livestock diagnostics and treatments are therefore required. The goal of this thesis was to develop a low-cost disposable biosensor that would permit point-of-care (POC) detection of diseases in bovines, through cost-effective, scalable microfabrication techniques. Such devices could enable real-time determination of the health status of animals on farm and contribute to more informed therapeutic interventions. Electrochemistry presents a viable option for POC devices in this regard and allows easy integration with portable electronics.
Electrochemical Impedance Spectroscopy (EIS) is a surface sensitive technique that measures the resistive and capacitive behaviour of an electrochemical system. It lends itself to serological immunosensor development as it allows label-free detection. For the purposes of this research, silicon devices were fabricated with six microband working electrodes, gold counter, and platinum pseudo-reference electrodes. The microband working electrodes were modified with a biocompatible co-polymer. This co-polymer supported the cross-linking of a bioreceptor (e.g., anti-bovine IgG) to electrode surface, which selectively bound to the target biomolecule (bovine IgG) in serum. This EIS device could distinguish between seronegative and seropositive samples in 15 minutes making it suitable for POC applications. Additionally, the presence of six working electrodes allowed for testing of multiple samples at a time. Often, however, only a single test is required. As such, silicon presents an expensive option for disposable sensors. Hence, polymer replication methods were also investigated in this thesis. This process allowed a single silicon wafer to be repeatedly used to produce polymer structures. A microneedle format was chosen to eliminate the need for taking samples on-farm and provide a pain-free method of in vivo measurements in interstitial fluid in interstitial fluid. The fabrication method used a double-sided micro-moulding process to move towards mass manufacturing. COMSOL simulations were performed to explore the active layer on the microneedle tip surface, ensuring no diffusional overlap between electrodes and providing the most effective tip design.
The microneedle structures also presented the opportunity for novel fabrication of nanoring arrays, by removing part of the protruding structure and exposing underlying nanorings. These have the potential to be highly sensitive electrochemical devices due to enhanced mass transport and high current densities, while maintaining the scalable cost-effective fabrication process of the microneedles. Devices produced steady-state CVs in a known redox molecule, with currents in the nA range
Associations between exposure to bovine herpesvirus 1 (BoHV-1) and milk production, reproductive performance, and mortality in Irish dairy herds
No full textAs cost-benefit analyses are required to prioritize and promote disease control and eradication programs within a jurisdiction, national data relating to disease-related production losses are particularly useful. The objectives of the current study were to use Irish bovine herpesvirus 1 (BoHV-1) prevalence data in dairy herds, obtained by bulk milk sampling on 4 occasions over the 2009 lactation, to document associations between milk production, fertility performance, mortality, and BoHV-1 herd status. Bulk milk (n = 305) antibody ELISA was used to classify farms as positive or negative in terms of endemic BoHV-1. Cow-level (milk parameters only) and herd-level performance data were sourced from the Irish Cattle Breeding Federation. Ordinary linear and negative binomial regressions were used to investigate associations between milk, fertility, and mortality performance and herd-level BoHV-1 results (both categorical and continuous variables). Only slight effects on the rates of carryover cows, nonpregnant cows, and total deaths were highlighted with increasing ELISA sample/positive (%) values (incidence rate ratio = 1.001). Multiparous cows in herds BoHV-1 bulk milk antibody positive recorded a reduction in milk yield per cow per year of 250.9 L in the multivariable linear model. Milk fat and protein yields were also affected by herd BoHV-1 status, again highlighting sub-optimal milk production in BoHV-1 bulk milk-positive herds. The current study has highlighted an economical method of investigating losses due to endemic infection using repeated bulk milk sampling over a single lactation. These data can contribute to analyzing the cost-benefit of applying BoHV-1 control strategies both on farm and at a national level
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
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