Gonadotrophin-releasing hormone treatment in cattle: a meta-analysis of the effects on conception at the time of insemination   总被引：1，自引：0，他引：1  

WF MORGAN  IJ LEAN 《Australian veterinary journal》1993,70(6):205-209

SUMMARY Data from 40 trials described in 27 published papers were analysed by meta-analysis (pooling of data from numerous trials into a single analysis) to evaluate the effects of injecting gonadotrophin-releasing hormone (GnRH) In cattle at the time of Insemination on the risk of pregnancy. A total of 19 019 cows were involved In these studies. Analyses were stratified by trial and by the effects of dose of GnRH, type of GnRH and Insemination number (first, second or third and greater). Mantel-Haenszel analysis revealed that use of GnRH at Insemination significantly Increased the overall risk of pregnancy by 12.5% In treated cows (P < 0.05). However, Increases In risk of pregnancy were greatest (22.5%) when repeat breeders were treated. Results for use of GnRH or analogue at first service were similar, with Increased risks of pregnancy in treated cows of 5.2 and 8.0%, respectively. The risk of pregnancy tended to be higher (11.1%) when the dose of GnRH was 250 μg and when used at second Insemination (9.9%). The analyses demonstrated that while treatment at Insemination with GnRH and GnRH analogues Increased conception rates In dairy cattle, some variation In study results was attributable to the number of Inseminations after calving at which GnRH Is administered. Further efforts should be made to determine characteristics of populations of cows that have good fertility responses to GnRH and to determine the mode of action of GnRH in Increasing fertility. Meta-analysis proved to be a useful technique for evaluating the apparently conflicting results from trials and in evaluating the effect of factors such as Insemination number, dose and type of GnRH on responses to treatment.  相似文献   

The endosymbiont hypothesis     

Doolittle WF 《Science (New York, N.Y.)》1981,213(4508):640-641

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WATERPROOFING LABELS FOR WET SPECIMENS     

Doolittle AA 《Science (New York, N.Y.)》1925,61(1588):591-592

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Feline immunodeficiency virus     

WF ROBINSON  SE SHAW  R ALEXANDER  I ROBERTSON 《Australian veterinary journal》1990,67(8):278-280

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Sex pheromones and reproductive isolation of the lesser peachtree borer and the peachtree borer   总被引：4，自引：0，他引：4  

J H Tumlinson  C E Yonce  R E Doolittle  R R Heath  C R Gentry  E R Mitchell 《Science (New York, N.Y.)》1974,185(151):614-616

(E,Z)-3,13-octadecadien-1-ol acetate, and (Z,Z)-3,13-octadecadien-1-ol acetate, isolated from the female lesser peachtree borer, Synanthedon pictipes (Grote and Robinson), and the female peachtree borer, Sanninoidea exitiosa (Say), respectively, strongly attract the respective males of these species in field bioassays. These compounds are the largest pheromones isolated thus far from a lepidopterous species. Sanninoidea exitiosa males did not respond to the synthesized (E,Z)-isomer, and low concentrations of it in the synthesized (Z,Z)-isomer did not interfere with their response to the (Z,Z)-isomer. In contrast, even very low concentrations of the (Z,Z)-isomer (1 percent) in the (E,Z)-isomer significantly inhibited the response of Synanthedon pictipes males.  相似文献   

Frequent recombination in a saltern population of Halorubrum     

Papke RT  Koenig JE  Rodríguez-Valera F  Doolittle WF 《Science (New York, N.Y.)》2004,306(5703):1928-1929

Sex and recombination are driving forces in the evolution of eukaryotes. Homologous recombination is known to be the dominant process in the divergence of many bacterial species. For Archaea, the only direct evidence bearing on the importance or natural occurrence of homologous recombination is anecdotal reports of mosaicism from comparative genomic studies. Genetic studies, however, reveal that recombination may play a significant role in generating diversity among members of at least one archaeal group, the haloarchaea. We used multi-locus sequence typing to demonstrate that haloarchaea exchange genetic information promiscuously, exhibiting a degree of linkage equilibrium approaching that of a sexual population.  相似文献   

Evolution of immunoglobulin polypeptide chains: carboxy-terminal of an IgM heavy chain   总被引：4，自引：0，他引：4  

R F Doolittle  S J Singer  H Metzger 《Science (New York, N.Y.)》1966,154(756):1561-1562

The dipeptide sequence at the carboxy-terminal of a heavy (micro) chain from a human macroglobulin ( IgM) is tyrosylcysteine, although the reverse sequence, cysteinyltyrosine, has not been rigorously excluded. The presence of cysteine at the carboxy-terminal was predicted from a recognition of the chemical homologies among the polypeptide chains of immunoglobulins, and their probable evolutionary origin.  相似文献   

Congenital hypothyroidism in Scottish Deerhound puppies     

WF ROBINSON  SE SHAW  B. STANLEY  RS WYBURN 《Australian veterinary journal》1988,65(12):386-389

Two Scottish Deerhound puppies had clinical and pathological features consistent with the diagnosis of congenital non-goitrous hypothyroidism. They were from separate litters, but were the progeny of the same sire and dam. The puppies were smaller, had shorter limbs and shorter, broader heads than their littermates. They also had histories of weakness, difficulty in walking and somnolence. A characteristic radiographic feature was the absence of epiphyseal growth centres. Both had depressed serum thyroxine (T4) levels and one did not respond to exogenous thyroid stimulating hormone. On necropsy, the thyroid glands were small, the follicles varied in size and contained little or no colloid. The adenohypophysis contained many cells with markedly vacuolated cytoplasm. It is suggested that the clinicopathological pattern is the result of a primary thyroid abnormality. Possible mechanisms include either primary thyroid hypoplasia or an unresponsiveness to thyroid stimulating hormone.  相似文献   

A comparison between terminal and rotational three-way crosses in mice     

D P Doolittle  S P Wilson 《Journal of animal science》1979,48(2):280-285

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The chemistry of water on alumina surfaces: reaction dynamics from first principles     

KC Hass  WF Schneider  A Curioni  W Andreoni 《Science (New York, N.Y.)》1998,282(5387):265-268

Aluminas and their surface chemistry play a vital role in many areas of modern technology. The behavior of adsorbed water is particularly important and poorly understood. Simulations of hydrated alpha-alumina (0001) surfaces with ab initio molecular dynamics elucidate many aspects of this problem, especially the complex dynamics of water dissociation and related surface reactions. At low water coverage, free energy profiles established that molecularly adsorbed water is metastable and dissociates readily, even in the absence of defects, by a kinetically preferred pathway. Observations at higher water coverage revealed rapid dissociation and unanticipated collective effects, including water-catalyzed dissociation and proton transfer reactions between adsorbed water and hydroxide. The results provide a consistent interpretation of the measured coverage dependence of water heats of adsorption, hydroxyl vibrational spectra, and other experiments.  相似文献