1,720,960 research outputs found
The effect of swine's semiochemicals on pigs' behavior, physiology and production
No full textThe objectives of this doctoral dissertation were to 1) evaluate how coprophagy benefits piglets, 2) the identification of maternal semiochemicals that might be acting as a fecal maternal pheromone, and 3) to evaluate if putative maternal semiochemicals (FMS) could be used to improve wean pig welfare and performance. The effect of coprophagy on nursing piglet hematology, behavior, and performance were assessed by depriving piglets of maternal feces the first seven days of age. Deprivation of maternal feces had no statistically significant effect on piglet behavior, RBC, HCT, and Hb (P > 0.05). Piglets with access to maternal feces (control) had better pre- and post-weaning performance than piglets deprived of maternal feces for the first seven days of age. Deprivation of maternal feces reduced piglets average daily gain and feed intake by 10 %. Piglets with access to maternal feces the first seven days of age weighed 9.6 kg more at 123 d post-weaning compare to the ones deprived of maternal feces the first seven days of age (P < 0.05).
To identify fecal maternal semiochemicals that might be acting as a maternal fecal pheromone and inducing coprophagy, fecal samples were collected from eight sows during gestation and lactation. Fecal semiochemicals were extracted with a SPE procedure and analyzed by GC/MS. Results showed that lactation increased the fecal concentrations of skatole and myristic acid (P < 0.05). During gestation the concentration of skatole and myristic acid were 11. 69 µg/g and 66.24 µg/g respectively. However, during lactation the concentration of these analytes significantly increased by 62 % and 11 % respectively (P < 0.05).
A free-choice preference assessment showed that piglets had a preference for feeders sprayed with 5 mL of a mineral oil solution containing skatole (4.5 mg) and myristic acid (9.0 mg) (P < 0.05), but not either molecule alone. The application of skatole and myristic acid to the feeders of weaned pigs statistically reduced piglet aggression by 30 % and increased feeding behavior by 35 % the first 24 h post weaning (P < 0.05). No difference in performance was observed over a 28-d period. Overall, because having access to maternal feces improved piglet performance by 10 %, coprophagy presents as a beneficial behavior to piglets. In addition, skatole and myristic acid might be acting as a multicomponent maternal semiochemical that attracts piglets and has a calming effect at weaning
Improving working dog performance through olfactory generalization and environmental acclimatization
No full textThe uses and need for detector dogs have increased in recent years. Detector dogs are deployed worldwide to locate targets. Despite this wide usage, detector dogs have documented issues generalizing to untrained target odors and detecting targets in adverse environmental conditions, both issues described in detail in chapter one. Research is needed in these areas to improve their performance, training, and welfare.
Training aids are devices used to mimic the odor of a target odor, employed when a target odor is rare or dangerous. In Chapter two, I determined the responses of seven dogs to five training aids, and three alternative training aids, to evaluate which one most accurately mimicked the odor of the true target material. I then used the most durable training aid that most closely perceptually matched the true material in a mock deployment scenario to test its usage for future field training. This study demonstrated how generalization testing can be used to create better training outcomes for detector dogs.
In Chapter three, I evaluated how the method of target odor introduction influenced response to novel targets. Dogs were divided into three training methods (1) sequential, in which dogs were trained to detect one target at a time, (2) mixture, in which dogs were trained to detect a mixture of four targets, and (3) inter-mixed, in which dogs were trained to detect four targets at the same time but presented in discrete learning trials. Dogs in the inter-mixed group showed moderately better generalization compared to the other training groups. This study emphasized the negative impact of unique volatiles on response rates and the need for further research in this area.
In Chapter four, I studied how the interaction of odor availability and dog physiology in adverse environmental conditions affects detection performance of four explosives (composition-4, ammonium nitrate, smokeless powder and trinitrotoluene). In this study dogs searched in four adverse environmental conditions (high temperature- high relative humidity, high temperature-low relative humidity, low temperature-high relative humidity, and low temperature- low relative humidity). Performance was compared to a standard condition. Poorer performance was observed for C-4 in high temperature environments. Subsequently, dogs were split into two groups. In the experimental group, dogs were acclimatized to adverse conditions daily. The control group received comparable detection training at room standard conditions. Dogs in the experimental group showed significantly better detection in the adverse condition after the acclimatization plan, compared to dogs in the control group.
Together these studies address two critical factors affecting detector dog performance (generalization and environmental acclimatization). Chapters two and three highlight the negative impact of unique odors on generalization in detector dogs. These studies provide insight into the future directions of generalization and categorization learning research in detector dogs. Chapter four illustrated how the effect of adverse environmental conditions on detector dog performance can be mitigated by a ten-day acclimatization plan. Future work in this area could refine this plan. These studies address critical problems in detector dog performance and suggest future directions for this research
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
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