6,528 research outputs found

    Legal Education in England

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    Studies relating to protein expression in the uterus of the cow

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    End of project reportEmbryo loss is a major cause of reproductive wastage in the cow. The majority of embryo loss occurs in the first 16 days after fertilisation when the embryo is critically dependent on the maternal uterine environment for survival. Despite the central role of uterine fluid in the normal growth and development of the embryo, there is limited information on the protein composition of these fluids. The main objectives of the studies in this thesis were to examine the protein composition of the bovine uterus during the oestrous cycle and to examine the relationship between the concentration of systemic progesterone and uterine protein expression in the cow. In the first study, the concentration of retinol-binding protein (RBP) in the bovine uterus was found to vary across the cycle and was 5-15-fold higher (P0.05) of the cycle, which was surprising given that previous studies have indicated that uterine RBP gene expression was positively associated with the concentration of systemic progesterone. In the second study, IGF binding protein 2 (IGFBP-2), IGFBP-3, IGFBP-4 and IGFBP-5 were identified in uterine fluid on days 3, 7, 11 and 15 of the oestrous cycle. There was a local effect on the concentration of IGFBPs where the concentration was greater on the ipsilateral side than that on the contralateral side for IGFBP-2 (P<0.05), 3 (P<0.01) and 5 (P<0.01) on day 15. This difference is a further indication of a local controlling mechanism regulating proteins between the uterine horns. Similar to RBP expression this study could find no significant relationship between the concentration of systemic progesterone and IGFBP concentrations on Day 7 of the oestrous cycle. In the third study, changes in the global pattern of uterine proteins between Days 3 and Day 15 of the oestrous cycle were examined using two-dimensional electrophoresis (2-DE). Six proteins were found to be upregulated on Day 15 compared to Day 3. Three proteins of these were identified as aldose reductase, plakoglobin and heat shock protein 27 while the other three proteins were identified as bovine serum albumin. Aldose reductase, an enzyme directly involved in the production of sorbitol and indirectly of fructose, was 10-fold higher (P<0.0001) on Day 15 compared to Day 3. Plakoglobin (Pg) was upregulated 2.3-fold (P<0.0001) on Day 15 compared to Day 3. Pg is a component of cellular junctions and its up-regulation may have a role in the uterine glandular epithelium. Heat shock protein 27 (Hsp27) was higher on Day 15 than on Day 3 (P<0.01) and Hsp27 was 1.4-fold higher in the ipsilateral compared to the contralateral uterine horn (P<0.01). Hsp27 may be secreted in response to potential stresses in the uterus or act as a molecular chaperone. On Day 7 there was no difference (P<0.05) in the pattern of proteins secreted between cows with low (2.7±0.10ng/ml) and high (4.8±0.13 ng/ml) concentrations of systemic progesterone on Day 7. The results of these studies have shown that dramatic changes occur in protein expression across the bovine oestrous cycle. Additionally, it emphasises the need for gene studies to be followed with protein studies as an adjunct or complementary tool. Proteins have a wide range of essential roles in the uterus and together these studies provide novel information on protein expression in the uterus of the cow

    Global gene expression in endometrium of high and low fertility heifers during the mid-luteal phase of the estrous cycle

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    peer-reviewedBackground In both beef and dairy cattle, the majority of early embryo loss occurs within the first 14 days following insemination. During this time-period, embryos are completely dependent on their maternal uterine environment for development, growth and ultimately survival, therefore an optimum uterine environment is critical to their survival. The objective of this study was to investigate whether differences in endometrial gene expression during the mid-luteal phase of the estrous cycle exist between crossbred beef heifers ranked as either high (HF) or low fertility (LF) (following four rounds of artificial insemination (AI)) using the Affymetrix® 23 K Bovine Gene Chip. Results Conception rates for each of the four rounds of AI were within a normal range: 70–73.3%. Microarray analysis of endometrial tissue collected on day 7 of the estrous cycle detected 419 differentially expressed genes (DEG) between HF (n = 6) and LF (n = 6) animals. The main gene pathways affected were, cellular growth and proliferation, angiogenesis, lipid metabolism, cellular and tissue morphology and development, inflammation and metabolic exchange. DEG included, FST, SLC45A2, MMP19, FADS1 and GALNT6. Conclusions This study highlights, some of the molecular mechanisms potentially controlling uterine endometrial function during the mid-luteal phase of the estrous cycle, which may contribute to uterine endometrial mediated impaired fertility in cattle. Differentially expressed genes are potential candidate genes for the identification of genetic variation influencing cow fertility, which may be incorporated into future breeding programmes.Teagasc Walsh Fellowship Programm

    Diffractive optics: Design, fabrication, and applications

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    The topics are presented in viewgraph form and include the following: features, applications, surface relief diffractive optics, optical data storage, waveguide lenses, diffractive lense imaging, phase grating synthesis, sub-wavelength structured surfaces, etc

    Why Don't Men Ever Stop to Ask for Directions? Gender, Social Influence, and Their Role in Technology Acceptance and Usage Behavior

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    Using the Technology Acceptance Model (TAM), this research investigated gender differences in the overlooked context of individual adoption and sustained usage of technology in the workplace. User reactions and technology usage behavior were studied over a five-month period among 342 workers being introduced to a new software system. At all three points of measurement, compared to women, men's technology usage decisions were more strongly influenced by their perceptions of usefulness. In contrast, women were more strongly influenced by perceptions of ease of use and subjective norm, although the effect of subjective norm diminished over time. These findings were robust even after statistically controlling for key confounding variables identified in prior organizational behavior research (i.e., income, occupation, and education levels), and another possible confound from technology research, prior experience with computers in general. Thus, in addition to identifying key boundary conditions in the role of the original TAM constructs (perceived usefulness and perceived ease of use), this research provides the basis for the integration of subjective norm into the model. In light of these findings, implications for theory and practice are discussed

    Biotechnology in Cattle Reproduction.

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    End of Project ReportTeagasc acknowledges support from the European Union 3rd and 4th Framework Programmes (CT-92-0163 and CT-95-0190)Over the next decade the Irish agri-food industry will have to compete in a rapidly changing world environment arising from increased competitiveness, decreased world market prices and increased consumer demands for higher quality, healthier and safer food. To become competitive in this environment the scale and efficiency of production at both farm and factory level will have to increase significantly and this must be achieved with due regard for the protection of the environment and the welfare of animals. New technologies will be needed to achieve this. Biotechnology will be central to the development of these new technologies. This project has been concerned with the identification and evaluation of biotechnology developments that have the potential to increase reproductive efficiency in cattle. This includes a range of technologies relating to the in vitro production, manipulation, cryopreservation and transfer of cattle embryos. The potential of other emerging technologies such as embryo and sperm sexing, cloning and biopharming or the production of commercially desirable proteins in cows milk are also addressed in this report.European Unoi

    Viability of in vitro produced cattle embryos.

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    End of Project ReportEmbryo transfer is being increasingly used in the cattle industry. As well as direct embryo transfers, many embryo-based biotechnologies have the potential to improve cattle production efficiency through enhanced breeding strategies, by facilitating the introduction of desirable traits such as disease resistance and through the production of desirable medical or pharmaceutical products in the milk. These biotechnologies are, however, dependent on a supply of viable in vitro produced (IVP) embryos. While the in vitro fertilization rate is high (80%) in cattle, only about 30 transferable embryos, or blastocysts, are produced from every 100 fertilized oocytes. A major factor affecting the viability of IVP embryos is their failure, in a high proportion of cases, to undergo normal development to the blastocyst stage in the manner of in vivo embryos. The major problem relates to a failure of the cells of IVP embryos to form a compact cell mass when they are 5 - 6 days old. This ultimately leads to developmental problems and compromised viability. Cell compaction is recognized as a critical event in early embryo development and has been associated with marked changes in protein synthesis and phosphorylation in the embryos of some species. This report is the first, to our knowledge, to describe the rate and pattern of protein synthesis and phosphorylation before, during and after compaction in both in vivo and in IVP cattle embryos. The main results are summarised below.European Union 4th Framework Programmes (Contract CT-95-0032

    Dead Or Alive? The Development, Trajectory And Future Of Technology Adoption Research.

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    Research on individual-level technology adoption is one of the most mature streams of information systems (IS) research. In this paper, we compare the progress in the area of technology adoption with two widely-researched streams in psychology and organizational behavior: theory of planned behavior and job satisfaction. In addition to gauging the progress in technology adoption research, this allows us to identify some fruitful areas for future research. Based on our comparison, we conclude that there has been excellent progress in technology adoption research. However, as a next step, we call for research focused on interventions, contingencies, and alternative theoretical perspectives (to the largely social psychology-based technology adoption research. Also, we believe it would be important to use the comparisons discussed here as a basis to develop a framework-driven set of future research directions to guide further work in this area

    Attitudes Toward Computers: The Impact on Performance

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    The proliferation of personal computers throughout business environments will continue to place demands on workers at all levels to develop proficient computer skills. A variety of training mechanisms exist that allow workers to introduce, develop, and hone any needed computer skills. Identical training mechanisms, however, are nonetheless likely to result in individuals with different computer abilities (Hicks, Hicks, and Senn, 1991). Existing researchhas examined differences in demographic factors (Dambrot, Silling, and Zook; 1988) as well as differences in attitudes (Torkzadeh and Koufteros, 1993). Much of the research that has examined this area has focused on the changes in attitudes (e.g. computeranxiety) that occur due to a training intervention. Research to date, however, has not extended this effect of training on attitudes as well as to performance. The theory of reasoned action (TRA) (Fishbein and Ajzen, 1975) suggests that attitudes will influence behavior, including performance. The Technology Acceptance Model (TAM) ( Davis, Bagozzi, and Warshaw, 1989) also suggests that attitudes towards use directly influence intentions to use the computer and ultimately actual computer use. Davis et al. demonstrate that an individual\u27s initial attitudes regarding a computer\u27s ease of use and a computer\u27s usefulness influence attitudes toward use. In addition to the attitudes of computer ease of use and computer usefulness, a number of other attitudes related to computer use have been identified in the research literature. Items measuring attitudes examined in this study have been previously defined and used in other studies. The attitudes and measures used in this study were perceived usefulness , perceived ease of use (Davis et al. 1989), computer anxiety (Loyd and Gressard, 1984), anticipation of computer use (Heinssen, Glass, and Knight, 1987), fear of computer use (Heinssen et al.,1987), and attitude toward previous academic achievement. Computer anxiety has been an attitude of primary focus that corresponds closely to the concept of math anxiety (Torkzadeh and Angulo, 1992). Although computer anxiety has definitions ranging from psychological, physical or sociological discomfort to fear. The definition of anxiety in this research referred to the psychological discomfort that might come from using a computer. This discomfort might come from using something unknown, concern over making mistakes or destroying pertinent information. In addition to measuring computer anxiety, we also wanted to measure computer fear. Although extreme anxiety might become fear, there is a distinction between the two constructs. Fear was defined as a trepidation that computers would change something about the individual, such as making the person too dependent on computers. Anticipation was defined as comfort with the idea of learning and using computer skills (Harrison and Ranier, 1992). Academic achievement provided a perceived measure of a subject\u27s past performance in both math and other academic endeavors. The perceived ease of use and usefulness constructs have been well established in the work by Davis et al. (Davis, 1989; Davis, Bagozzi, and Warshaw, 1992). Perceived usefulness was defined as the degree to which a person believes that using a particular system would enhance his or her job performance . Perceived ease of use was defined as the degree to which a person believes that using a particular system would be free of effort (Davis, 1989, pg. 320)
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