• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1276
  • 1022
  • 503
  • 104
  • 104
  • 104
  • 104
  • 104
  • 104
  • 83
  • 59
  • 59
  • 39
  • 24
  • 20
  • Tagged with
  • 3807
  • 1344
  • 587
  • 518
  • 493
  • 489
  • 330
  • 328
  • 328
  • 309
  • 280
  • 249
  • 249
  • 214
  • 203
  • 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.
551

Evaluation of responses of sows and their litters to feeding patterns

Kwansa, Wilhelmina 12 July 1991 (has links)
Graduation date: 1992
552

Effect of olanzapine on feeding and selected biochemical factors related to weight gain

Tan, Wei 02 May 2005
<p>Olanzapine is an atypical antipsychotic drug exhibiting a low incidence of extrapyramidal side effects. It is not only effective in treating positive symptoms of schizophrenia, but also more efficacious against negative and depressive symptoms than classical antipsychotics. Olanzapine has been recommended as the first-line drug for the treatment of schizophrenia. Unfortunately, a common side effect of olanzapine, namely weight gain, has also been observed. A comprehensive literature analysis revealed that olanzapine induced higher weight gain than most other antipsychotics, only second to clozapine. The incidence of olanzapine-induced weight gain and related diseases, such as diabetes and cardiovascular diseases, is higher than that of the general population. These unwanted side effects have decreased the adherence to treatment. Many clinical observations and preliminary animal studies have attempted to elucidate the possible mechanism involved. To date, the mechanism for olanzapine-induced weight gain remains unclear.</p><p>This research project utilizes an animal model to investigate the possible mechanism of olanzapine-induced weight gain. The specific research objectives include: 1) does olanzapine affect feeding behavior; 2) can olanzapine influence the levels of glucose and triglyceride; 3) are cytokines, such as insulin, leptin, and TNF-Ñ involved in olanzapine-induced weight gain; 4) how does olanzapine affect adipose tissue?</p><p> An olanzapine-induced weight gain animal model has been established in the present investigation. An increase in food and water intake and increase in fat deposition accompanied with weight gain after treatment were observed. No significant increase in levels of glucose and triglyceride was detected. The changes of insulin and leptin levels in blood suggest that olanzapine may affect the endocrine system. A dramatic morphological alteration of adipose tissue by olanzapine was serendipitously observed. Immunohistochemical staining revealed that olanzapine stimulated collagen VI expression and deposition in the extracellular matrix suggesting that adipocyte differentiation may be enhanced. The effect of olanzapine on fat deposition might play a critical role in olanzapine-induced weight gain. The data from adipose tissue have provided a new clue on future research in understanding the mechanism of olanzapine-induced weight gain. Due to limitation of small number of animals and relatively short term of treatment, a large variation in groups diminished the power of analysis regarding the effects of olanzapine related to weigh gain.
553

Nutritional implications in broilers fed single or a combination of feed ingredients during feed shortages in the Republic of Yemen

Modhish, Abdulmalek M. 07 February 1991 (has links)
Most of the feed required for poultry production in the Republic of Yemen is imported from Europe. Sometimes, feed shipments arrive later due to lack of hard currencies to pay for the feed or to pay the freight charges. Yemeni broiler producers in such cases feed their birds a single feed ingredient or a mixture of ingredients until feed arrives. Five experiments were conducted to simulate feed shortage situations. As a single ingredient, barley is the grain of choice in case of feed shortages. When broilers were switched to corn-soy after the single ingredient diets, the compensatory growth was correlated with the severity of reduced growth. Feeding diets with a mixture of faba beans + sorghum grain with or without 7% herring meal for 21 and 49 days, respectively, reduced significantly (P<.05) mean body weight, total feed consumed, feed efficiency and apparent protein efficiency ratio. Feeding wheat bran at 10-15% with adjustment for protein and energy from day-old to 49 days of age resulted in significantly (P<.05) improved mean body weights compared to the control broilers. Increasing wheat bran levels further gradually reduced body weight and feed consumption. Abdominal fat increased significantly (P<.05) when wheat bran inclusion exceeded 20 percent. Cellulase supplementation did not show any significant interaction with wheat bran in all the measured parameters. Supplementing protease to wheat bran diets significantly (P<.05) reduced mean body weight, feed consumption and the feed conversion in broilers. These dramatic effects were proportionally ameliorated by increasing the levels of wheat bran. / Graduation date: 1991
554

Sociocultural Barriers to Breast Feeding in African American Women with Focused Intervention to Increased Prevalence

Simpson, Alicia C 02 November 2012 (has links)
Objective: The goal of this study is to uncover sociocultural barriers to breastfeeding among African American women in the Atlanta metropolitan area and provide an educational intervention based on identified barriers to increase the willingness to breastfeed. Methods: Non-Hispanic African American women, 6 to 9 months pregnant, between the ages of 18 and 45, of varying socioeconomic status were recruited from multiple Obstetrics and Gynecology clinics throughout the Atlanta-metropolitan area. Participants completed a self-administered pre-test survey that questioned their intention to breastfeed and anticipated barriers associated with breastfeeding. Those who were unsure of breastfeeding or did not plan to breastfeed were asked to participate in an educational intervention that provided information about breastfeeding, the benefits to mother and baby and managing commonly perceived barriers. Immediately after the intervention a post-test was provided. A second post-test was conducted after all participants delivered their baby. Chi-square analysis was performed to examine the distribution of actual breastfeeding initiation rates by initial intention as well as by age, income and education. Results: Forty-nine women participated in the study. 18 of 20 women (90%) who intended to exclusively breastfeed initiated breastfeeding. Sixteen women reported that they did not intend to breastfeed. After receiving the intervention, 56.3% (n=9) initiated breastfeeding. Thirteen women reported they were unsure of their feeding plans in the pretest. Of these, 69.2% (n=9) initiated breastfeeding. Participants reported their primary barriers to breastfeeding were fear of pain, difficulty breastfeeding once they returned to work and lack of support from family, friends and their partner/spouse/father of the child. A significant association was observed between ages 25-29 years old and initiation of breastfeeding in women who were unsure of their breastfeeding plans (p=0.005). No association was found between income or education and initiation of breastfeeding. Conclusion: Education about breastfeeding was a significant barrier to breastfeeding in the African-American women in our study population. Women who participated in the intervention were more likely to initiate breastfeeding. Employment status, income, and education were not significant factors in a woman’s decision to initiate breastfeeding.
555

Effect of olanzapine on feeding and selected biochemical factors related to weight gain

Tan, Wei 02 May 2005 (has links)
<p>Olanzapine is an atypical antipsychotic drug exhibiting a low incidence of extrapyramidal side effects. It is not only effective in treating positive symptoms of schizophrenia, but also more efficacious against negative and depressive symptoms than classical antipsychotics. Olanzapine has been recommended as the first-line drug for the treatment of schizophrenia. Unfortunately, a common side effect of olanzapine, namely weight gain, has also been observed. A comprehensive literature analysis revealed that olanzapine induced higher weight gain than most other antipsychotics, only second to clozapine. The incidence of olanzapine-induced weight gain and related diseases, such as diabetes and cardiovascular diseases, is higher than that of the general population. These unwanted side effects have decreased the adherence to treatment. Many clinical observations and preliminary animal studies have attempted to elucidate the possible mechanism involved. To date, the mechanism for olanzapine-induced weight gain remains unclear.</p><p>This research project utilizes an animal model to investigate the possible mechanism of olanzapine-induced weight gain. The specific research objectives include: 1) does olanzapine affect feeding behavior; 2) can olanzapine influence the levels of glucose and triglyceride; 3) are cytokines, such as insulin, leptin, and TNF-Ñ involved in olanzapine-induced weight gain; 4) how does olanzapine affect adipose tissue?</p><p> An olanzapine-induced weight gain animal model has been established in the present investigation. An increase in food and water intake and increase in fat deposition accompanied with weight gain after treatment were observed. No significant increase in levels of glucose and triglyceride was detected. The changes of insulin and leptin levels in blood suggest that olanzapine may affect the endocrine system. A dramatic morphological alteration of adipose tissue by olanzapine was serendipitously observed. Immunohistochemical staining revealed that olanzapine stimulated collagen VI expression and deposition in the extracellular matrix suggesting that adipocyte differentiation may be enhanced. The effect of olanzapine on fat deposition might play a critical role in olanzapine-induced weight gain. The data from adipose tissue have provided a new clue on future research in understanding the mechanism of olanzapine-induced weight gain. Due to limitation of small number of animals and relatively short term of treatment, a large variation in groups diminished the power of analysis regarding the effects of olanzapine related to weigh gain.
556

Bite performance and feeding kinematics in loggerhead turtles (Caretta caretta) within the context of longline fishery interactions

Guzman, Alejandra 15 May 2009 (has links)
Feeding biomechanics and foraging behavior are likely contributors to loggerhead sea turtle (Caretta caretta) bycatch in the pelagic longline fishery. To investigate these contributions, loggerhead bite performance was measured in several size classes of captive-reared juveniles, captive sub-adults and adults, as well as wild loggerheads. A kinematic study was conducted to investigate loggerhead interactions with modified longline hooks. Kinematic and behavioral variables were assessed in relation to five longline hooks to determine if loggerhead feeding behavior is modulated relative to hook type, size, and offset. The bite force study demonstrated that mean maximum post-hatchling bite force was 2.5N and mass was the best predictor of post-hatchling bite force. Mean maximum bite force of juveniles with mean straight carapace length (SCL) of 12, 31, 44, and 65 cm were 27, 152, 343, and 374 N, respectively. Sub-adult and adult mean maximum bite force was 575 N. Maximum bite force had a positive linear relationship with all head and body morphometrics (P<0.001). Carapace width was the best predictor of bite force throughout ontogeny. The kinematic study demonstrated no differences between hook treatments in all kinematic variables analyzed. The results of this study suggest loggerhead feeding behavior may be stereotypical. Only 33% of all interactions resulted in “hooking” events. “Hooking” was lowest in 16 gage circle hooks with no offset and the 18 gage circle hooks with 10°offset which may be indicative of a lower possibility of the turtle drowning. “Hooking” was highest in the 16 gage circle hooks with 10°offset. The proportion of turtles “hooked” in the mouth was significantly greater than those “hooked” in the throat (P=0.001). Sixteen gage circle hooks with 10° offset had the highest percentage of throat “hooking”, and the 18 gage circle hooks without offset resulted in the lowest percentage of throat hooking. When interacting with J hooks with a 25° offset (9 gage), turtles mostly oriented their head away from the hook offset; however, when interacting with the 16 and 18 gage circle hooks with 10° offset, turtles mostly oriented their heads toward the hook offset. These data suggest that turtles may distinguish between small and large offsets, and may modulate their feeding behavior accordingly. Alternatively, turtles may be detecting hook size or hook shape. A more thorough characterization of loggerhead bite performance and feeding kinematics will be useful when developing or modifying longline fishery gear aimed at reducing loggerhead bycatch.
557

Characterization of Feeding Behavior Traits and Associations with Performance and Feed Efficiency in Finishing Beef Cattle

Mendes, Egleu Diomedes Marinho 2010 August 1900 (has links)
The first objective of this study was to validate the feeding behavior measurements from a radio frequency electronic system (GrowSafe (TM) System Ltd., Airdrie, AB, Canada) and examine the software sensitivity to different parameter settings (MPS) to quantify feeding behavior traits. Data was continuously recorded 24 h per day using the GrowSafe™ system for 32 heifers over 81-d. Ten animals were randomly selected and evaluated over 6-d using time-lapse video recordings. Different parameter settings (MPS) from the electronic system (GrowSafe (TM)) used to record feeding behavior data, bunk visits (BV) frequency and BV duration, were compared with the observed (video) values. The second objective of this study was to quantify meal criterion; examine the associations between feeding behavior traits, performance, and feed efficiency; and the effects of breed type on feed efficiency (residual feed intake - RFI) and feeding behavior traits in heifers fed high-grain diets. Results from study one demonstrated that the GrowSafe (TM) system 4000E could accurately predict BV and meal data compared to observed data. The 100 s, used for the maximum duration between consecutive EID recordings to end an uninterrupted BV, was the appropriate MPS to predict BV frequency and duration, and meal frequency and duration compared to observed data using the GrowSafe (TM) 4000E system. The system’s ability to detect the animal’s presence or absence at the feed bunk was 86.4 and 99.6 percent, respectively. Results from the second study demonstrated that the meal criterion for heifers fed high-grain diets was 13.8 min. The 4 methods to calculate meal criterion demonstrated no differences in results of frequencies and durations of meal and the number of bunk visits per meal. Similar phenotypic correlations were found between the feeding behavior traits with RFI derived from the base model or with adjustments for final back fat. The adjustment of RFI to final back fat changed the RFI rank between breeds. The addition of feeding behavior traits to the RFI base model could accounted up to 40.4 percent of the variation in DMI not explained by ADG or MBW.
558

Connecting the Circadian Clock with Chemosensation

Chatterjee, Abhishek 2011 May 1900 (has links)
Chemoreception is a primitive sense universally employed by organisms for finding and selecting food, rejecting toxic chemicals, detecting mates and offspring, choosing sites for egg-laying, recognizing territories and avoiding predators. Chemosensory responses are frequently modulated based on the internal environment of the organism. An organism’s internal environment undergoes regular changes in anticipation and in response to daily changes in its external environment, e.g., light-dark cycle. A resettable timekeeping mechanism called the circadian clock internally drives these cyclical changes with a ~24 hour period. Using electrophysiological, behavioral and molecular analyses, I tested where and how these two conserved processes, viz., the circadian timekeeping mechanism and the chemosensory pathway, intersect each other at organismal and cellular levels. The presence of autonomous peripheral oscillators in the chemosensory organs of Drosophila, prompted us to test whether chemosensory responses are under control of the circadian clock. I found that local oscillators in afferent (primary) chemosensory neurons drive rhythms in physiological and behavioral responses to attractive and aversive chemical signals. During the middle of the night, high level of G proteincoupled receptor kinase 2 (GPRK2), a clock controlled signaling molecule present in chemosensory neurons, suppresses tastant-evoked responses and promotes olfactory responses. G-protein mediated signaling was shown to be involved in generating optimal response to odorants. Multifunctional chemosensory clocks exert control on feeding and metabolism. I propose that temporal plasticity in innate behaviors should offer adaptive advantages to flies.
559

Comparative feeding biomechanics and behavioral performance of feeding in the family kogiidae and tursiops truncatus (odontoceti, cetacea)

Bloodworth, Brian Edward 17 September 2007 (has links)
Hyolingual biomechanics and kinematics in three species of two odontocete genera were investigated to compare adaptations and performance of divergent feeding strategies. Ram and suction feeding are two ends of a continuous spectrum that is poorly-studied in odontocetes. Comparative anatomy identified characters associated with feeding patterns of morphologically dissimilar and evolutionary distant genera. Hyolingual investigations included measurements of hyolingual muscle vectors and hyoid surface area/robustness. ANOVA's revealed Kogia basihyal and thyrohyal surface areas were significantly greater than T. truncatus. However, most predicted muscle tension values were not significantly different between genera. The presence of lateral gape occlusions, broad basihyal and thyrohyals near the caudal oral cavity, and a broad, short tongue were likely responsible for Kogia's effective suction mechanism. These features were absent, or reduced, in T. truncatus. The feeding kinematics of dwarf and pygmy sperm whales (Kogia sima and K. breviceps), and bottlenose dolphins (Tursiops truncatus) were characterized and compared incorporating the Ram-Suction Index (RSI). Mean RSI data support a suction feeding strategy for the phylogenetically basal Kogia (-0.67; S.D.±0.29) and a ram feeding strategy for the more-derived Tursiops (0.94; S.D.±0.11). Tursiops displayed two ram-based feeding behaviors, closed gape approach, where gape increased near food items, and open gape approach, where gape was at least 50% of maximum in the first video field. Four feeding phases were identified in both odontocetes: preparatory, jaw opening, gular depression, and jaw closing. The mean Kogia feeding cycle duration (470 ms; S.D.±139) was significantly shorter (P<0.003) than all Tursiops groups (pooled: 863 ms; S.D.±337, closed gape approach: 662 ms; S.D.±207, open gape approach: 1211 ms; S.D.±207). Kogia mean maximum gape angle (39.8°; S.D.±18.9), mean maximum opening, and closing gape angle velocities (293°/s; S.D.±261 and 223°/s; S.D.±121, respectively) were significantly greater (P<0.005) than pooled Tursiops mean maximum gape angle (24.8°; S.D.±6.6), mean maximum opening and closing gape angle velocities (84°/s; S.D.±56 and 120°/s; S.D.±54, respectively). Negative Kogia RSI values were correlated with increasing maximum hyoid depression and retraction, wide gape angle, and rapid opening gape velocity. Kinematic data support functional hypotheses that odontocetes generate suction by rapid depression of the hyoid and tongue.
560

Ecological comparisons of growth and feeding between Pomacea canaliculata and Pomacea scalaris

Li, Min-Ching 09 August 2008 (has links)
The distribution of apple snail Pomacea canaliculata is islandwide but Pomacea scalaris is only found in southern Taiwan. In order to gain more information on the not well-known invasive species of P. scalaris, the growth and feeding of P. canaliculata and P. scalaris were studied. The hatching period of P. canaliculata (10.4¡Ó1.3 days) was shorter than that of P. scalaris (12.2¡Ó2.3 days). And, the hatching size of P. canaliculata was also smaller. Two weeks after hatching, a significant higher growth rate in P. canaliculata had been found. The 75-day growth equations for P. canaliculata and P. scalaris were y = 0.29x + 1.09 (p < 0.001) and y = 0.16x + 1.68 (p < 0.001), respectively. Feeding structures of mandible, radulae, central tooth and stomach in P. canaliculata were larger than that of P. scalaris. But, there was no significant difference in the length of gut between the two species. Food passing time in P. canaliculata (1.4¡Ó0.7 days) was less than that of P. scalaris (2.9¡Ó0.7 days). And, the approximate digestibility per day of P. canaliculata (44.41¡Ó24.02%) was higher than that of P. scalaris. Through the analyses of £_13C, £_15N, stomach content and feces, it is known that they have the same trophic level with similar food sources. Additionally, the values of £_13C and £_15N were significantly different between sites of JiouRu and Wugou-shui, Pingtung. In other words, the feeding environments were different between the two sites. Based on the results, it is concluded that the superiority of growth and feeding performance in P. canaliculata is important in shaping its wide distribution in Taiwan.

Page generated in 0.0663 seconds