• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 494
  • 196
  • 56
  • 48
  • 37
  • 32
  • 31
  • 29
  • 17
  • 6
  • 4
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 1052
  • 325
  • 163
  • 127
  • 115
  • 104
  • 98
  • 98
  • 77
  • 68
  • 66
  • 62
  • 55
  • 53
  • 50
  • 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.
31

Roles of the DOG-1 and JRH-1 helicase-like proteins in DNA repair in Caenorhabditis elegans

Youds, Jillian L. 05 1900 (has links)
Helicases perform vital roles in the cell by unwinding D N A to make it accessible for the essential processes of replication, transcription and repair. In Caenorhabditis elegans, the DOG- 1 helicase-like protein is required for polyG/polyC-tract (G/C-tract) maintenance, as dog-l animals have a mutator phenotype characterized by deletions that initiate in G/C-tracts. DOG-1 may unwind secondary structures that form in polyguanine D N A during lagging strand replication. In order to more completely understand the role of dog-1, genetic interactors were identified, dog-1 functionally interacts with the him-6/BLM helicase. Absence of recombinational repair-implicated proteins in the dog-1 background, including HIM-6/BLM, RAD-51, BRD-1/BARD1 and HIM-9/XPF, as well as the trans-lesion synthesis polymerases polKMD po/7 increased the frequency of animals with G/C-tract deletions, indicating that these pathways are important mechanisms for repair at G/C-tracts in the absence of DOG-1. These data support the hypothesis that persisting D N A secondary structures can cause replication fork stalling, which can be resolved by deletion-free or deletion-prone mechanisms. DOG-1 has highest sequence identity to human BR1P1/FANCJ, which is mutated in patients from the Fanconi Anemia (FA) subgroup J. D N A damage sensitivity experiments indicated that, like chicken F A N C J cells, dog-1 mutants were not significantly sensitive to DNA damage from X-ray or UV-irradiation, but were extremely hypersensitive to the D N A interstrand cross-linking agent UVA-activated trimethylpsoralen. Thus, DOG-1 appears to have a conserved role in cross-link repair and is the C. elegans F A N C J homolog. Characterization of the dog-1/FANCJ-relatsd helicase, Jrh-1, revealed that mutants for this putative helicase are moderately sensitive to cross-linking agents, dog-1 jrh-1 double mutants displayed a synthetic lethal phenotype characterized by excessive recombination intermediates and mitotic catastrophe in the germline. However, absence of JRH-1 did not have any effect on G/C-tract deletions, indicating that JRH-1 does not have a redundant function with DOG-1 at G/C-tracts. Absence of JRH-1 reduced the fitness of eTl and nTl translocation hétérozygotes, but not translocation homozygotes, jrh-1 was synthetically lethal with him-6/BLM and with the endonuclease mus-81, suggesting a possible role for JRH-1 in regulating the balance between different types of repair.
32

Roles of the DOG-1 and JRH-1 helicase-like proteins in DNA repair in Caenorhabditis elegans

Youds, Jillian L. 05 1900 (has links)
Helicases perform vital roles in the cell by unwinding D N A to make it accessible for the essential processes of replication, transcription and repair. In Caenorhabditis elegans, the DOG- 1 helicase-like protein is required for polyG/polyC-tract (G/C-tract) maintenance, as dog-l animals have a mutator phenotype characterized by deletions that initiate in G/C-tracts. DOG-1 may unwind secondary structures that form in polyguanine D N A during lagging strand replication. In order to more completely understand the role of dog-1, genetic interactors were identified, dog-1 functionally interacts with the him-6/BLM helicase. Absence of recombinational repair-implicated proteins in the dog-1 background, including HIM-6/BLM, RAD-51, BRD-1/BARD1 and HIM-9/XPF, as well as the trans-lesion synthesis polymerases polKMD po/7 increased the frequency of animals with G/C-tract deletions, indicating that these pathways are important mechanisms for repair at G/C-tracts in the absence of DOG-1. These data support the hypothesis that persisting D N A secondary structures can cause replication fork stalling, which can be resolved by deletion-free or deletion-prone mechanisms. DOG-1 has highest sequence identity to human BR1P1/FANCJ, which is mutated in patients from the Fanconi Anemia (FA) subgroup J. D N A damage sensitivity experiments indicated that, like chicken F A N C J cells, dog-1 mutants were not significantly sensitive to DNA damage from X-ray or UV-irradiation, but were extremely hypersensitive to the D N A interstrand cross-linking agent UVA-activated trimethylpsoralen. Thus, DOG-1 appears to have a conserved role in cross-link repair and is the C. elegans F A N C J homolog. Characterization of the dog-1/FANCJ-relatsd helicase, Jrh-1, revealed that mutants for this putative helicase are moderately sensitive to cross-linking agents, dog-1 jrh-1 double mutants displayed a synthetic lethal phenotype characterized by excessive recombination intermediates and mitotic catastrophe in the germline. However, absence of JRH-1 did not have any effect on G/C-tract deletions, indicating that JRH-1 does not have a redundant function with DOG-1 at G/C-tracts. Absence of JRH-1 reduced the fitness of eTl and nTl translocation hétérozygotes, but not translocation homozygotes, jrh-1 was synthetically lethal with him-6/BLM and with the endonuclease mus-81, suggesting a possible role for JRH-1 in regulating the balance between different types of repair.
33

Drug target discovery by transcriptome analysis of the brown dog tick, Rhipicephalus sanguineus, synganglion : initial characterisation of a nicotinic acetylcholine receptor

Lees, Kristin January 2008 (has links)
A normalised cDNA library was constructed from the synganglia of unfed adult <i>R. sanguineus.  </i>Of interest from a drug discovery perspective were ESTs encoding a chitinase enzyme and four transmembrane receptors including two glutamate-gated chloride receptors, a leucokinin-like receptor and a nicotinic acetylcholine receptor (nAChR) α subunit. The nAChR α subunit was chosen for further study.  This is the first identified full-length arachnid nAChR subunit.  Phylogenetically it is most similar to insect α1 nAChR group and has been called Rsα1.  This subunit is expressed in larval, nymphal and adult stages and within partially fed adult females.  <i>Rsα1 </i>was most abundant in the synganglion and also present in Malpighian tubules and oviduct yet was undetected in the salivary glands and gut tissues.  Using two-electrode voltage clamp in <i>Xenopus laevis </i>oocytes, Rsα1 did not functionally express as a homomer or when co-expressed with the vertebrate chicken β2 subunit using either RNA or DNA.  Chimeric constructs consisting of the tick N-terminal and the transmembrane portion of the <i>D. melanogaster </i>α2 nAChR (Dα2) (Rsα1-Dα2) and vice-versa were prepared.  Responses to acetylcholine were obtained from the Dα2-Rsα1 chimera showing that the Rsα1 nAChR can form a functional pore region.  However, no responses were obtained from the Rsα1-Dα2 chimera.  This preliminary data suggests that the Rsα1 nAChR cannot form a functional ligand binding region when expressed in Xenopus oocytes. The present study has proven that the tick synganglion is a rich source of transmembrane receptor targets for exploitation in future drug discovery.
34

Studies on Echinococcus granulosus (Batsch, 1786) and Toxoplasma gondii (Nicolle and Manceaux, 1908) in Libya

Gusbi, A. M. January 1988 (has links)
No description available.
35

Traumatic hindlimb neuropathies of dogs and cats : With special reference to the sciatic nerve and its origins

Sharp, N. J. H. January 1982 (has links)
No description available.
36

An electrophysiological study of the effects of stimulation of left atrial receptors on efferent vagal nerve fibres

Walters, G. E. January 1986 (has links)
No description available.
37

The isolation of the humoral agent in the atrial receptor diuresis

Pither, J. M. January 1983 (has links)
No description available.
38

Obesity Management Using Diacylglycerol and Low Glycemic Index Starch in Dogs

Nagaoka, Daisuke 16 January 2010 (has links)
Obesity is the most common nutritional disorder in small animal medicine and is closely related to the mortality and morbidity of various diseases. Decreasing the incidence of obesity is considered to be the most important way to maintain health, prevent disease, and contribute to longevity. Diet therapy using low glycemic index starch (LGIS) and diacylglycerol (DAG) may thus be a reasonable obesity management tool without unnecessary food restriction, forced physical activity, and impairment of health. Beagles were prepared for a weight loss study by inducing obesity using a high caloric/human snack food combination. These obese dogs were then fed diets containing either LGIS/HGIS and DAG/TAG for a 10 wk weight loss period. The LGIS groups lost more weight than the high glycemic index starch (HGIS) groups (2% vs 1% per wk) due to lower total diet digestibilities. Even though the dogs had consumed similar amounts of the diets on a weight basis, the amounts of metabolizable energy (ME) ingested overall differed between the two starch types. Diet effects were found for plasma triglyceride (TG) at both wk 1 and 8. Post-prandial TG lowering was observed only with a LGIS/DAG diet combination. LGIS groups showed less decreased post-prandial non esterified fatty acid (NEFA) concentrations compared with HGIS groups at both wk 1 and 8. At both wk 1 and 8, plasma insulin was significantly lower in the LGIS groups although glucose concentrations were similar among all groups. Plasma gastric inhibitory polypeptide (GIP) increased in all groups but tended to be lower in the LGIS groups. Significant time effects were seen in glucagon-like peptide-1 (GLP-1) at both wk 1 and 8; however, diet effects were not observed. Plasma adiponectin concentrations were significantly higher in the LGIS/DAG group vs. all other diet groups. Significantly lower plasma leptin concentrations were found, especially in the LGIS/DAG group. Combinations of LGI starch and oils decreased uncoupling protein-2 (UCP2) mRNA gene expression in the small intestine compared with the combinations of HGI starch and oils. These findings indicate that the LGIS/DAG combination beneficially supports more efficient and healthy weight loss in dogs along with improvement in biochemical and hormonal biomarkers. This combination may be preferred for healthy canine weight loss and to help prevent obesity related diseases.
39

Customers’ buying behaviour   toward premium dog food brands -   A case study of Bozita Robur

Nilsson, Christofer, Liashchenko, Anastasiia, Andreasson, Rebecka January 2010 (has links)
Purpose: The purpose of this thesis is to contribute to knowledge of customers’ buying behaviour toward premium dog food by examining their brand associations and how these are shaped by using Bozita Robur as a case study. Background: Market for dog food has increased heavily during the last decades what made knowledge of underlying driving forces of dog food consumption crucial for dog food producers. Quite peculiar is a phenomenon of purchasing behaviour towards a product purchased but not consumed turning it into a more complex and dynamic object of study. Lack of coherent and conclusive research that offer an understanding of primary behavioural drivers and preferences of Swedish dog food customers makes it a good opportunity to continue investigating the dog food industry. Method: The study is conducted in the form of a single case study. A survey instrument is used to collect data on awareness and to identify behavioural beliefs and subjective norms of consumers, followed by phone interviews that uncover their attitudes towards dog food brands. Lantmännen Doggy’s brand Bozita Robur is used for this purpose. Data collected is further analyzed with the application of consumer behaviour related theories. Findings: The study has found that Swedish customers have built a positive image associated with premium dog food brands, where superior quality is the primary association. On the brand schema level, each of the premium dog food brands investigated holds specific associations in consumer minds, whereas the strength of these associations depends much on brand recognition levels. Bozita Robur, though less familiar among respondents, was found to have a positive brand schema and is associated with Swedishness and high quality. Customers of premium dog food brand actively search for information when making a purchasing decision towards a dog feed brand. In a product, they do value high nutrition content. Dog owners are influenced by various social groups, among which breeders and specialty store staff have the strongest influence when it comes to purchasing advice of the dog food brands.
40

Customers’ buying behaviour   toward premium dog food brands -   A case study of Bozita Robur

Nilsson, Christofer, Liashchenko, Anastasiia, Andreasson, Rebecka January 2010 (has links)
<p><strong>Purpose: </strong>The purpose of this thesis is to contribute to knowledge of customers’ buying behaviour toward premium dog food by examining their brand associations and how these are shaped by using Bozita Robur as a case study.<strong></strong></p><p><strong>Background:</strong> Market for dog food has increased heavily during the last decades what made knowledge of underlying driving forces of dog food consumption crucial for dog food producers. Quite peculiar is a phenomenon of purchasing behaviour towards a product purchased but not consumed turning it into a more complex and dynamic object of study. Lack of coherent and conclusive research that offer an understanding of primary behavioural drivers and preferences of Swedish dog food customers makes it a good opportunity to continue investigating the dog food industry.</p><p><strong>Method:</strong> The study is conducted in the form of a single case study. A survey instrument is used to collect data on awareness and to identify behavioural beliefs and subjective norms of consumers, followed by phone interviews that uncover their attitudes towards dog food brands. Lantmännen Doggy’s brand Bozita Robur is used for this purpose. Data collected is further analyzed with the application of consumer behaviour related theories.</p><p><strong>Findings: </strong>The study has found that Swedish customers have built a positive image associated with premium dog food brands, where superior quality is the primary association. On the brand schema level, each of the premium dog food brands investigated holds specific associations in consumer minds, whereas the strength of these associations depends much on brand recognition levels. Bozita Robur, though less familiar among respondents, was found to have a positive brand schema and is associated with Swedishness and high quality.</p><p><strong> </strong>Customers of premium dog food brand actively search for information when making a purchasing decision towards a dog feed brand. In a product, they do value high nutrition content. Dog owners are influenced by various social groups, among which breeders and specialty store staff have the strongest influence when it comes to purchasing advice of the dog food brands.</p>

Page generated in 0.0527 seconds