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41.
F. J. W. England 《Euphytica》1972,21(3):523-526
Summary A cheap and easily made apparatus for controlled pollination in grasses and other wind-pollinated plants is described. 相似文献
42.
The fertility and whelping complications of normal bitches and of bitches that had had surgery to correct a vaginal abnormality of varying severities were compared retrospectively. Reproductive performance and whelping statistics were compared between 37 bitches that had been diagnosed with a vaginal abnormality and 37 age- and breed-matched bitches with no history of vaginal abnormalities. There were no significant differences in reproductive performance between the affected and control bitches. When analysed by the severity of the abnormality, pregnancy rates were significantly lower for the group of bitches with the most severe abnormalities compared with the group of bitches that had mild vaginal abnormalities. Furthermore, the bitches that had severe abnormalities were significantly more likely to require a caesarean section than those with mild abnormalities. 相似文献
43.
44.
Studies on canine pregnancy using B-mode ultrasound: Diagnosis of early pregnancy and the number of conceptuses 总被引:1,自引:0,他引:1
The ultrasonic (B-mode) detection of canine pregnancies was first achieved 21 to 23 days after the calculated luteinising hormone peak when daily examinations were made in six bitches. In 51 pregnant bitches examined for the first time between 20 and 35 days, one bitch was incorrectly diagnosed as non-pregnant 24 days after the calculated luteinising hormone peak. In only 31-8 per cent of pregnancies was conceptal number accurately determined. The greatest tendency was to underestimate the number of conceptuses. 相似文献
45.
Gilts bred at first (n = 18) and third (n = 18) estrus were assigned in replicates of equal numbers to be slaughtered on d 3, 15 and 30 post-mating to assess fertilization rate, embryonic losses and serum concentrations of estrogen (estradiol-17 beta + estrone) and progesterone. Mean number of ovulations was lower among gilts bred at first vs third estrus (12.2 vs 14.5; P less than .05), with no difference in fertilization rate (100 vs 98%). Embryonic survival was lower (P less than .05) among gilts bred at first vs third estrus on d 15 (78.1 vs 95.4%) and 30 (66.7 vs 89.4%) of gestation. Serum estrogen (pg/ml) and progesterone (ng/ml) levels, although lower in gilts bred at first vs third estrus, were not significantly different at the three stages of gestation studied. The ratio of progesterone to estrogen in gilts bred at first estrus was higher than in those bred at third estrus on d 15 (439 +/- 71 vs 210 +/- 17) and 30 (597 +/- 106 vs 179 +/- 50), but was lower on d 3 (187 +/- 37 vs 444 +/- 123; stage of gestation X estrous period interaction, P less than .05). These data suggest that changes in the ratio of systemic levels of estrogen and progesterone may be related to early embryonic mortality in gilts bred at pubertal estrus. 相似文献
46.
G C England 《The Veterinary record》1991,129(10):221-222
47.
Twenty-two bitches with ultrasonographically diagnosed spontaneous pyometra were treated with a combination of 5 microg/kg cabergoline per day and 5 mug/kg cloprostenol every third day, and potentiated sulphonamide twice a day. Bitches with either open-cervix or closed-cervix pyometra showed a rapid clinical improvement, associated with a reduction in plasma progesterone concentration, increased vulval discharge and a reduction in the diameter of the uterus. The haematological profiles of 21 of the bitches returned to normal within six days of treatment, and their biochemical profiles returned to normal within nine days; 19 of the bitches were managed successfully by a 10-day period of treatment. Two bitches required a further three days of treatment, and in one bitch with a partial uterine torsion the treatment was not successful. Adverse effects of the treatment were limited to the 60 minutes immediately after the administration of prostaglandin, and included retching, vomiting, mild abdominal straining, diarrhoea and panting. The incidence of adverse effects was reduced after each successive dose of prostaglandin. Eleven of the 21 successfully treated bitches were mated at the next oestrus, and seven became pregnant; their litters were smaller than the published breed averages. In four of the bitches the pyometra recurred after the next oestrus. 相似文献
48.
Chen CC Lamping KG Nuno DW Barresi R Prouty SJ Lavoie JL Cribbs LL England SK Sigmund CD Weiss RM Williamson RA Hill JA Campbell KP 《Science (New York, N.Y.)》2003,302(5649):1416-1418
Calcium ion (Ca2+) influx through voltage-gated Ca2+ channels is important for the regulation of vascular tone. Activation of L-type Ca2+ channels initiates muscle contraction; however, the role of T-type Ca2+ channels (T-channels) is not clear. We show that mice deficient in the alpha1H T-type Ca2+ channel (alpha(1)3.2-null) have constitutively constricted coronary arterioles and focal myocardial fibrosis. Coronary arteries isolated from alpha(1)3.2-null arteries showed normal contractile responses, but reduced relaxation in response to acetylcholine and nitroprusside. Furthermore, acute blockade of T-channels with Ni2+ prevented relaxation of wild-type coronary arteries. Thus, Ca2+ influx through alpha1H T-type Ca2+ channels is essential for normal relaxation of coronary arteries. 相似文献
49.
G.C.W. England M. Russo S.L. Freeman 《Veterinary journal (London, England : 1997)》2013,195(2):179-184
Little is known about the response of the bitch’s reproductive tract to semen deposition. In this study, an influx of polymorphonuclear neutrophils (PMNs) into the uterus was detected after artificial insemination, but there was normal fertility. Doppler ultrasonography showed that insemination induced an increase in uterine artery blood velocity and a decrease in the resistance index of short duration, indicating vasodilation. Semen that was extended in fluid from the sperm rich fraction of the ejaculate (seminal plasma, SP), or third fraction of the ejaculate (prostatic fluid, PF), produced a similar magnitude of effect but of longer duration. It was hypothesised that vasodilation following insemination was largely induced by SP and PF which, together with PMN influx, was part of a normal uterine response.Physiological concentrations of PMNs in vitro reduced the ability of spermatozoa to attach to uterine epithelium, most likely as a result of spermatozoa becoming attached to PMNs. However, both SP and PF increased attachment of spermatozoa to the uterine epithelium by reducing sperm attachment to PMNs, and potentially by an additional mechanism that did not involve inhibition of sperm binding to PMNs. These are the first canine studies to document an apparent physiological response by the uterus to semen, associated with uterine artery vasodilation and PMN influx. Moreover, these investigations are the first to demonstrate that canine SF and PF are part of the mechanism for increasing uterine perfusion and that both fluids have a modulatory effect on PMN-induced inhibition of spermatozoal attachment to uterine epithelium, most likely mediated by reduced sperm attachment to PMNs. 相似文献
50.
Lucy Asher Simon Blythe Rena Roberts Lisa Toothill Peter J. Craigon Katy M. Evans Martin J. Green Gary C.W. England 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(6):431-438
An early understanding of behavioral suitability for guiding work in domestic dogs (Canis familiaris) would be useful for organizations which train dogs as mobility aids, such as the Guide Dogs for the Blind Association. We explored the potential for a standardized test of behavior in young dogs to reflect subsequent success in guide dog training. Five hundred eighty-seven potential guide dogs were exposed to a series of eight stimuli at 6-8 weeks of age. The responses of dogs were scored on a 7-point scale according to either responsiveness to human assessor or to environmental stimuli, on stimuli comprising following when called; retrieve; gentle restraint; noise; stroking; a moving toy squirrel; encouragement to go through a tunnel; and encouragement to go over a ramp. Five of these stimuli showed some association with success in guide dog training, and three of these stimuli could be usefully combined in a logistic regression model of success in training. There is potential for this test to be used to predict suitability for guiding work but adjustments to the scoring protocol are recommended. 相似文献