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Prediction of cow fertility based on productivity traits in dairy cattle under different production systems
Get PDFA study to examine factors that influence dairy cattle fertility was conducted
in the United Kingdom (UK) and Malawi. Productivity data from the UK
comprising 56,014 records from 574 Holstein cows were retrieved from a
database at Scotland’s Rural College Dairy Research Centre in Dumfries.
The cows were of either high (select) or average (control) genetic merit and
fed total mixed rations with high or low forage. These formed four production
systems - high forage select (HFS), low forage select (LFS), high forage
control (HFC) and low forage control (LFC). Data from Malawi were obtained
through a baseline survey in 67 smallholder farms and monitoring of 28 and
62 dairy cows from smallholder farms and a commercial farm, respectively.
The breeds were Holstein-Friesians and Holstein-Friesian x Malawi Zebu
crosses predominantly fed forages supplemented with concentrates. Some
cows were fitted with accelerometers to enable monitoring of cow activity
which was then related to cow fertility and energy balance. The data were
analysed using descriptive statistics, mixed models and logistic regression
models using SAS 9.3.
The UK data showed that production system significantly (p<0.05) influenced
milk yield, body energy content (BEC) and fertility. BEC is a trait that
indicates absolute level of energy in the body per day regardless of energy
use and intake the previous day. Daily milk yield of LFS cows was 35±0.1
(mean±SEM) litres which was significantly (p<0.05) higher than that of LFC
(30.4±0.1 litres), HFS (27.5±0.1 litres) and HFC (24.3±0.1 litres) cows. LFS
cows also had the highest milk yield acceleration to peak milk yield (0.51
litres/day/day) than (LFC 0.47±0.02 litres/day/day), HFC (0.47±0.03
litres/day/day) and HFS (0.46±0.03 litres/day/day) cows. The interval from
calving to nadir BEC was 68±5, 83±6, 88±5 and 106±6 days for LFC, LFS,
HFC and HFS cows, respectively. Days to first high luteal activity (DFHLA)
and days to successful service (DSS) were significantly different with
production system and genetic merit, respectively. LFC cows had DFHLA of
27±2 days (mean±SEM) which were significantly lower (p<0.05) than those
of HFC (30±3 days), HFS (30±2 days) and LFS (35±3 days) cows. Average
genetic merit cows had significantly lower (p<0.05) DSS (119±5 days,
mean±SEM) than high genetic merit cows (132±5 days). Results from data
collected in Malawi showed variations that reflected differences in
management and other environmental factors. Average daily milk yield per
lactation in Malawi was 13.3±4.9 (mean±SD) litres. Fertility traits in the UK
herd were better than those in Malawi herds. The average DFHLA in Malawi
was 79±29 days while in the UK it was 31±18 days. Cow activity in both the
UK and Malawi farms varied with the feeding system, genetic merit and BEC.
Select cows on home grown feeding system were more active (motion index
=6250±40), stood longer (13.4±0.04 hours/day) and spent more time eating
(5.6±0.32 hours/day, mean±SEM) than select cows on by products feeding
system that had motion index, standing and eating time of 5166±37,
11.9±0.04 hours/day and 4.6±0.16 hours/day, respectively.
Genetic merit, lactation number, days to first observed oestrus, calving BEC,
service BEC and service milk yield were significant predictors of pregnancy
to first insemination (p<0.05) while genetic merit, milk yield, percentage BEC
between calving and service, service milk yield and service BEC were
significant predictors (p<0.05) of pregnancy to the first three inseminations.
Validation of models derived showed C-statistics of the receiver operating
characteristic (ROC) curve of 0.66 (95% confidence interval (CI): 0.57 to
0.75) and 0.65 (CI: 0.55-0.75), respectively. It is concluded that genetic merit,
feeding system, parity, energy status and stage of lactation are the major
factors that determine the likelihood of achieving pregnancy following
insemination. Models developed have a potential to predict the probability of
pregnancy to an insemination at an acceptable level of accuracy
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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