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991.
992.
993.
W V Holt H D Moore R D North T D Hartman J K Hodges 《Journal of reproduction and fertility》1988,82(2):717-725
Hormonal detection of urinary pregnanediol-3 alpha-glucuronide proved an effective method of monitoring the progress of oestrous cycles in the blackbuck; observation of sexual behaviour in a vasectomized male was, however, a more practical procedure. Good correlation was observed between the occurrence of minimal pregnanediol concentrations in females and the maximal behavioural response by the male. On the basis of intervals between periods of behaviourally detected oestrus, a mean cycle length of 16.9 days (+/- 0.62, s.e.m.) was derived from 12 cycles (4 animals). Eleven females were inseminated in this study, 8 with freshly collected semen and 3 with frozen semen; 6 calves were obtained, 1 after the use of frozen semen. Pregnancy was monitored by measurements of pregnanediol-3 alpha-glucuronide excretion and by ultrasound scanning. The mean interval between insemination and parturition was 183.3 days inclusive, ranging from 182 to 186 days. 相似文献
994.
James H. Wyche Janet Kennedy Zlata Hartman Philip E. Hartman James Diven 《Journal of bacteriology》1974,120(2):965-969
A mutation at the divD locus in Salmonella typhimurium confers a round-cell morphology and enhances cell division under certain growth conditions. 相似文献
995.
Restoration of a Forest Understory After the Removal of an Invasive Shrub, Amur Honeysuckle (Lonicera maackii) 总被引:2,自引:0,他引:2
The recruitment of native seedlings is often reduced in areas where the invasive Amur honeysuckle (Lonicera maackii) is abundant. To address this recruitment problem, we evaluated the effectiveness of L. maackii eradication methods and restoration efforts using seedlings of six native tree species planted within eradication and unmanipulated (control) plots. Two eradication methods using glyphosate herbicide were evaluated: cut and paint and stem injection with an EZ‐Ject lance. Lonicera maackii density and biomass as well as microenvironmental characteristics were measured to study their effects on seedling growth and survivorship. Mean biomass of Amur honeysuckle was 361 ± 69 kg/ha, and density was 21,380 ± 3,171 plants/ha. Both eradication treatments were effective in killing L. maackii (≥ 94%). The injection treatment was most effective on large L. maackii individuals (>1.5 cm diameter), was 43% faster to apply than cutting and painting and less fatiguing for the operator, decreased operator exposure to herbicide, and minimized impact to nontarget vegetation. Deer browse tree protectors were used on half of the seedlings, but did not affect survivorship or growth. After 3 years, survival of native seedlings was significantly less where L. maackii was left intact (32 ± 3%) compared with the eradication plots (p < 0.002). Seedling survival was significantly different between cut (51 ± 3%) and injected (45 ± 3%) plots. Species had different final percent survival and rates of mortality. Species survival differed greatly by species (in descending order): Fraxinus pennsylvanica > Quercus muehlenbergii ≥ Prunus serotina≥ Juglans nigra > Cercis canadensis > Cornus florida. Survivorship and growth of native seedlings was affected by a severe first‐year drought and by site location. One site exhibited greater spring soil moisture, pH, percent open canopy, and had greater survivorship relative to the other site (55 ± 2 vs. 30 ± 2%). Overall, both L. maackii eradication methods were successful, but restorationists should be aware of the potential for differential survivorship of native seedlings depending on species identity and microenvironmental conditions. 相似文献
996.
997.
Hyman Hartman 《Journal of theoretical biology》1975,51(2):501-509
The endosymbiotic theory of the origin of the centriole is found lacking as no DNA has been found in the structure. The centriole is related to the ribosome in that it is a structure nucleated by RNA. This RNA (morphic) has the property of localizing itself at the site of the old centriole before nucleating a new one. The implication of this property of the localization of RNA is discussed with respect to the way the eukaryotic cell determines its shape. 相似文献
998.
Although moral case deliberation (MCD) is evaluated positively as a form of clinical ethics support (CES), it has limitations. To address these limitations our research objective was to develop a thematic CES tool. In order to assess the philosophical characteristics of a CES tool based on MCDs, we drew on hermeneutic ethics and pragmatism. We distinguished four core characteristics of a CES tool: (a) focusing on an actual situation that is experienced as morally challenging by the user; (b) stimulating moral inquiry into the moral concepts, questions and routines in the lived experience of the CES tool user; (c) stimulating moral learning by exploring other perspectives; and (d) incorporating contextual details. We provide an example of a CES tool developed for moral dilemmas over client autonomy. Our article ends with some reflections on the normativity of the CES tool, other application areas and the importance of evaluation studies of CES tools. 相似文献
999.
H. D. M. Moore M. Bush M. Celma ‡ A-L. Garcia ‡ T. D. Hartman J. P. Hearn J. K. Hodges D. M. Jones J. A. Knight L. Monsalve ‡ D. E. Wildt 《Journal of Zoology》1984,203(2):269-278
Artificial insemination was carried out on three adult captive Giant pandas (Ailuropoda melanoleuca). Oestrus in these animals was detected by behavioural observations and by the rise in urinary oestrogen metabolites. Semen was collected from a mature male by electroejaculation. Changes in the quality of semen and the size of the testes indicated a seasonal fluctuation in sperm production. Spermatozoa were capable of penetrating zona-free hamster oocytes and remained viable for up to five days at 15–20°C in a modified Tyrode's medium. After freezing and thawing in a cryopreserving diluent, approximately 50% of spermatozoa recovered progressive motility and displayed a similar velocity to spermatozoa prior to freezing. Unusual protrusions of the acrosome of the panda spermatozoon were noted.
Following insemination, one female conceived and gave birth, after a gestation of 159 days, to two cubs, one of which subsequently died. Another female exhibited a rise in circulating progesterone but pregnancy was not confirmed. 相似文献
Following insemination, one female conceived and gave birth, after a gestation of 159 days, to two cubs, one of which subsequently died. Another female exhibited a rise in circulating progesterone but pregnancy was not confirmed. 相似文献
1000.