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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

Modulation of Sensing and Sharing Food-Related Information in the Honey Bee

January 2017 (has links)
abstract: Food is an essential driver of animal behavior. For social organisms, the acquisition of food guides interactions with the environment and with group-mates. Studies have focused on how social individuals find and choose food sources, and share both food and information with group-mates. However, it is often not clear how experiences throughout an individual's life influence such interactions. The core question of this thesis is how individuals’ experience contributes to within-caste behavioral variation in a social group. I investigate the effects of individual history, including physical injury and food-related experience, on individuals' social food sharing behavior, responses to food-related stimuli, and the associated neural biogenic amine signaling pathways. I use the eusocial honey bee (Apis mellifera) system, one in which individuals exhibit a high degree of plasticity in responses to environmental stimuli and there is a richness of communicatory pathways for food-related information. Foraging exposes honey bees to aversive experiences such as predation, con-specific competition, and environmental toxins. I show that foraging experience changes individuals' response thresholds to sucrose, a main component of adults’ diets, depending on whether foraging conditions are benign or aversive. Bodily injury is demonstrated to reduce individuals' appetitive responses to new, potentially food-predictive odors. Aversive conditions also impact an individual's social food sharing behavior; mouth-to-mouse trophallaxis with particular groupmates is modulated by aversive foraging conditions both for foragers who directly experienced these conditions and non-foragers who were influenced via social contact with foragers. Although the mechanisms underlying these behavioral changes have yet to be resolved, my results implicate biogenic amine signaling pathways as a potential component. Serotonin and octopamine concentrations are shown to undergo long-term change due to distinct foraging experiences. My work serves to highlight the malleability of a social individual's food-related behavior, suggesting that environmental conditions shape how individuals respond to food and share information with group-mates. This thesis contributes to a deeper understanding of inter-individual variation in animal behavior. / Dissertation/Thesis / Doctoral Dissertation Biology 2017
522

The use of animals for medical experimentation : an analysis of young people's perceptions in Britain

Sullivan, Jane Elizabeth January 2006 (has links)
Understanding public attitudes towards using animals for medical experimentation and the issues that cause public concern is of importance scientifically, economically and ethically. Although national opinion poll data appear to provide enough evidence to propose the hypothesis that 'the majority of people in Britain support animal research' it is clear from reviewing the literature that the attitudes of young people have not been adequately explored. Furthermore, the ethical considerations and scientific understanding underpinning such attitudes are also poorly understood. It is also clear that we have little comprehension of how ethnic minority groups in our society view animal experimentation (AE). The aim of this study is therefore to acquire a contemporary, comprehensive understanding of young people's perceptions of AL This is pursued by means of a custom made questionnaire that also seeks to explore knowledge/understanding and values/belief systems within a cross-cultural context. Qualitative aspects of the study, both verbal and pictorial, enrich the quantitative data generated, allowing a unique insight into how young people articulate their attitudes towards AE. The findings from this study reveal that young people hold a diverse array of attitudes towards AE. Their support is dependent on animal species, which for non-Islamic respondents appears to be based on traditional Western considerations of phylogenic hierarchy. For Islamic respondents, however, attitudes towards certain animals diverge from this phylogenic classification, being driven instead perhaps by traditional cultural relationships with animals. Cross-cultural differences of how animals are viewed were also apparent when value typologies were measured. Scales to assess the human-animal bond and instrumental attitudes towards animals demonstrate that Islamic respondents have a less emotional attachment to animals, viewing them more instrumentally. The human-animal relationship scales reveal no such differences. Young people appear to have a poor knowledge base regarding issues surrounding AE and have a negative image of animal welfare within research facilities. These perceptions correlate with attitudes towards AE and hence suggest that there is a need for greater communication between scientists and lay people regarding this issue. When compared with other scales measuring instrumental uses of animals, Islamic respondents supported AE to a lesser extent than might have been expected, which may reflect a lower level of general medical understanding. Gaining a greater understanding of young people's perceptions of AE is not only important in its own right but may also be of general benefit in the arena of public understanding of science. The recommendations from this study therefore suggest routes to strengthen scientific communication in regard to the issue of AB that might also be applicable to more general areas of science.
523

Effects of an Early Life Immune Challenge on Body Growth, Personality, Mating Behaviors, and Brain Development of Zebra Finches (Taeniopygia guttata)

Uysal, Ahmet Kerim 23 June 2017 (has links)
The developmental stress hypothesis predicts that an aversive condition, such as decreased food intake, predation, and social isolation, in the early developmental stage could have long term effects on behaviors and brain development of an animal. In nature, bird nestlings are susceptible to various factors, such as malnutrition, infections, and parasites. Effects of early life stress on adulthood have been extensively studied with some stressors including malnutrition. However, immune challenges as an early life stressor and their long-term programming effects on adult behaviors are yet to be studied in detail. The goal of the current study was to investigate changes in growth rate, personality, mate selection behaviors and brain development in zebra finch nestlings after injection with a viral infection mimicking agent, Polyinosinic: polycytidylic acid (Poly I:C). By using Poly I:C, it was possible to isolate long-term effects to the immune response of the bird. After Poly I:C injection on post-hatch day (PD) 14, morphological measures were conducted to detect changes in body growth rate. When birds became sexually mature (> ~PD 200), behaviors of birds were observed in different conditions to detect changes associated with the personality traits of animals. In mate choice trials, both attractiveness of males and mate selection behaviors of males and females were investigated. Finally, the development and neuronal activity of specific brain nuclei involved in courtship (i.e., HVC and RA) and social/sexual behaviors (nucleus taeniae of the amygdala, TnA) were investigated. The results showed that nestlings’ growth rate was not affected. However, Poly I:C injection had some effects on certain, but not all, personality traits observed in the study. Such effects were found only in female zebra finches, suggesting that there was a limited sex-specific influence of an early life immune challenge on personalities of adults. The results also showed that Control females tended to choose untreated males over Poly I:C injected males in mate choice trials. Finally, Poly I:C injection negatively affected the overall development of targeted brain nuclei. In addition, neuronal activity in TnA was higher in Poly I:C injected birds. Results of the present study suggest that one time injection with Poly I:C early in the life causes long term effects on adulthood. These findings are further discussed regarding their relevance to the developmental stress hypothesis.
524

INFLUENCE OF ERGOT ALKALOIDS ON RUMEN MOTILITY: TIME AND CONCENTRATION OF ERGOVALINE + ERGOVALININE REQUIRED TO IMPACT RETICULORUMEN MOTILITY

Riccioni, Kara 01 January 2017 (has links)
Fescue toxicosis is problematic for ruminant livestock, causing weight loss and low productivity when fed endophyte-infected forages. Complete underlying mechanisms of toxicosis are unknown therefore; the objective of the study was to determine if ruminally dosed ergot alkaloids impact rumen motility. Cannulated steers were pair-fed a forage diet and ruminally dosed with endophyte-free (E-) or endophyte-infected (E+) tall fescue seed. An 8-h period of rumen motility collection began 4-h after feeding by monitoring pressure change via a wireless telemetry and transducer system. In experiment 1, steers were paired by weight and assigned to E- or E+ treatment. Overall, E+ steers had more frequent contractions. On d 7 - 9, both treatments had lower frequencies and E- steers had greater amplitude of contractions, which corresponded with decreased DM intake. In experiment 2 steers remained in pair, but switched treatment. During the 57 d E+ steers received titrated levels of ergovaline + ergovalinine. There was no difference between treatments for frequency or amplitude of contractions, but increasing dosage, decreased frequency (d 1 - 44) and amplitude, coinciding with lower DM intakes. Alteration in rumen motility associated with changes in intake may be responsible for the decreased productivity in ruminants consuming E+ forages.
525

Interaction Of Stocking Density And The Feeding Environment In Lactating Holstein Dairy Cows

Campbell, Mackenzie Andrew 01 January 2017 (has links)
Stocking density serves as a sub-clinical stressor impacting natural behavior and affective state of dairy cows. However, cows rarely experience stocking density as an isolated stressor. Understanding the effects of stocking density with additional management stressors such as low-fiber diets or feed restriction is the next step in alleviating stress and improving the well-being of lactating dairy cows housed in freestall barns. The overall goal of this dissertation was to evaluate the interaction of stocking density and the feeding environment on short-term production, behavioral, ruminal fermentation, and stress responses of lactating dairy cattle. The first two studies (Chapter 2 and 3) served as preliminary research for the main studies of this dissertation. The first study objective was to evaluate the effectiveness of using chopped wheat straw to reduce sub-acute ruminal acidosis (SARA) in order to formulate diets for the first main study. Treatments were low straw (0 kg dry matter (DM)/d; LS) and high straw (1.36 kg DM/d; HS). High straw appeared to effectively reduce SARA by lowering time below pH 5.8 with minimal impact on feed intake and rumination. The second study objective was to evaluate the effect of type of blood collection tube on haptoglobin concentration across two commercially-available haptoglobin assays and evaluate assay agreement in order to determine haptoglobin concentrations for the main studies. Lithium heparinized, sodium heparinized, and K2-EDTA plasma resulted in increased haptoglobin concentrations compared to serum using the Tri-Delta colorimetric assay, but no differences were observed using the Life Diagnostics ELISA assay. However, there was a lack of agreement between assays and further identification of a gold-standard assay is needed before analyzing haptoglobin for the main studies. The third study (Chapter 4) investigated the interaction of stocking density (100% and 142% of freestalls and headlocks) and source of forage fiber (no added straw and added straw at 3.5% ration DM). Treatments did not impact feed intake, but straw diets tended to reduce milk production. Increasing stocking density reduced lying time but increased efficiency of stall use. Though feeding and rumination times were unaffected, overstocking shifted the location of rumination away from the freestall. Increased stocking density tended to increase stress responses. Both greater stocking density and no straw diets increased SARA, and the combination of these stressors tended to exacerbate this pH response. Adding straw to the diet reduced the negative impacts of overstocking on ruminal pH. The fourth study (Chapter 5) evaluated the interaction of stocking density (100% and 142%) and feed access (5-h reduced feed access and no reduced feed access). Treatments had minimal impact on short-term feed intake and production. Overstocking affected behavior similar to responses observed in Chapter 4. Reducing feed access decreased feeding time, though cows altered feeding and rumination responses to maintain daily rumination. Both treatments shifted priorities for feeding and lying behavior, though increased stocking density had the larger impact. Though reduced feed access did not impact ruminal pH, an exacerbated response was observed when combined with increased stocking density. The combination of stocking density and feeding environment stressors exacerbate negative effects on biological function and should be avoided.
526

BEHAVIORAL GAIT CHANGE CHARACTERIZATION AND DETECTION USING PRECISION DAIRY MONITORING TECHNOLOGIES

Jones, Barbara Wadsworth 01 January 2017 (has links)
Lameness is a painful disorder that decreases performance and is highly recognized as one of the most important health and welfare concerns for dairy cattle. Visual gait scoring is the most common way to detect gait change in dairy cattle. However, this is not only subjective, but is also time consuming and costly. A need to remove the subjective assessment of human observation exists. Therefore, automatic gait change detection for continuous monitoring by precision dairy monitoring technologies may be beneficial. The first objective of this research was to characterize behavior and production variables as cow gait changed to evaluate potential usefulness in gait change detection across two different studies. Weighted gait score was a significant (P < 0.05) predictor of rumination time for study 1. Rumination time decreased as weighted gait score increased. However, for study 2, numbers of steps and feeding time were significant predictors (P < 0.05). Number of steps increased as weighted gait score increased. Time at the feedbunk and feedbunk visits decreased as cows weighted gait score increased. The second objective was to compare behavior and production variables for each individual gait aspect in increasing gait scores to evaluate potential usefulness in gait change detection across two different studies. For study 1, milk yield, rumination, and neck activity decreased as cows as tracking score increased. For study 2, lying time decreased as cow’s general symmetry score increased. Feedbunk visits decreased as cows tracking score increased. Number of steps increased as cow’s spine curvature score increased. Time active increased as cows head bobbing score increased. Activity increased as cows speed score increased. Lying time decreased as cow’s abduction/adduction score increased. The third objective was to detect gait change utilizing multiple precision dairy monitoring technologies in two different studies. For study 1, 56% of predicted gait scores were within 0.25 points of the actual weighted gait score and for study 2, 41% of predicted gait scores were within 0.25 points of the actual weighted gait score. Pearson Correlation for study 1 and 2 was 0.43 and 0.46, respectively. For both studies, the Pearson Correlation yielded results in the low category, when evaluating goodness of fit.
527

Seasonal activity and road mortality of the snakes of the Pa-Hay-Okee wetlands of Everglades National Park

Bernardino, Frank S. 23 July 1990 (has links)
The current study describes the composition and activity of the snake community of the Pa-hay-okee wetlands of Everglades National Park. The study was conducted from January 1987 to January 1989. Sixteen species were observed, with Thamnophis sauritus, Thamnophis sirtalis, Nerodia fasciata pictiventris, and Agkistrodon piscivorus representing 90.2% of the total sample. The seasonal distribution and activity of the snakes were closely related to fluctuations in the water table. Most activity occurred in the winter months as snakes migrated west following the drying water edge of Shark River Slough. Seventy percent of all snakes observed during this study were either injured or dead on the road. Over 50% of annual mortality occurred during migration. The impact that road mortality is having on the local snake community cannot be ignored. Management options are provided to minimize loss. A comparison is made to the snake community of the Long Pine Key Region of Everglades National Park.
528

The Effect of Bat Predation on Crop Yield in Thailand and the Winter Garden Region of South-Central Texas

Cooney, Jackson 01 January 2018 (has links)
The Wrinkle-lipped free-tailed bat (T. plicata) in Thailand and the Brazilian free-tailed bat (T. brasiliensis) in south-central Texas are integral in the control of agricultural pests. The effect on the production of rice and cotton is determined by the bats consumption of a particular pest species in that region. In Thailand, it is the White-Backed Planthopper (Sogatella furcifera), while in south-central Texas, it is the cotton bollworm (Helicoverpa zea). The ecological service these bat species provide is measured in millions of dollars saved by farmers each year. Finally, a conclusion was made about which species had a greater effect on the economy when compared to each other.
529

The development of the EEG in the Gerbil

Bonner, Susan 01 January 1974 (has links)
No description available.
530

Optimization of Vegetative Filter Strips for Mitigation of Runoff from Golf Course Turf

DeFlorio, Barbara 21 March 2018 (has links)
Many pesticides are listed as possible or probable human carcinogens, leading to a public concern over their environmental impact. Vegetative filter strips (VFS) have been developed to intercept runoff water and prevent pesticides from contaminating surface and ground water. The first half of this project identified five plants (big blue stem, blue flag iris, eastern gama grass, prairie cord grass and wool grass) that best removed pesticides from contaminated soil. The current study evaluated four treatment groups: the five selected plant species arranged (1) randomly, (2) in a succession from short (upslope) to tall (downslope), (3) turfgrass cut to three heights from short (upslope) to tall (downslope) and (4) unvegetated (UVFS), in an effort to optimize vegetative filter strips to reduce the movement of pesticides contained in runoff from turfgrass environments. Simulated rainfall was applied to 12 VFS (0.91 m x 4.6 m x 1.83 m), each with a 5% slope. The VFS were used to evaluate the effect of three vegetated treatments on the effectiveness of VFS for mitigation of pesticide-contaminated runoff from treated turf. For the runon simulation, five pesticides (chlorothalonil, chlorpyrifos, imidacloprid, pendimethalin, and propiconazole) were added at 5% their maximum application rate for turfgrass to a nurse tank containing the amount of runoff expected to occur from an uphill turf plot (5.5 m2) during either a 1- (6.1 cm) or 5-yr (9.65 cm) rain event. Runoff samples were collected at the downhill base (bottom) of each VFS and analyzed for pesticides to determine the effectiveness of VFS at mitigating runoff water and the pesticides contained. Soil core and soil pore water samples were taken periodically post-application. All samples were analyzed for applied pesticides and quantified by GC/MS and LC/MS/MS. All vegetated treatments were more effective in decreasing the runoff volume and the associated pesticide concentration when compared with UVFS, with turfgrass being the most effective of the three treatments. This research validates the use of VFS in slowing the flow of runon water significantly enough for it to infiltrate into the soil, instead of leaving the VFS as runoff. VFS are already suggested as a best management practice to prevent pesticides from leaving many agricultural sites treated with pesticides, but this research suggests their widespread use on golf courses, parks, athletic fields and home lawns could greatly reduce the amount of pesticides in runoff waters from turf environments and help keep our waterways clean.

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