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排序方式: 共有209条查询结果,搜索用时 31 毫秒
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Louis D. Heyward Theodore I. J. Smith Wallace E. Jenkins 《Journal of the World Aquaculture Society》1995,26(4):475-479
Abstract.— Juvenile white bass Morone chrysops (age 158 d, 110.4 mm total length) were reared at salinity levels of 0, 4, 8, 12, 16, and 20 parts per thousand (ppt). Fish (10/tank) were stocked in 64-L tanks with four replicates/treatment ( N = 40heatment) and fed a pelleted feed daily. Fish were sampled semimonthly for 70 d. Fish reared at salinities of 12 ppt and below were significantly ( P ≤ 0.05) larger (mean = 151.5 mm total length; range 146.8–155.7 mm) than fish reared at salinities of 16 and 20 ppt (mean 133.7 mm total length; range 131.5–135.8 mm) after 70 d. Survival was also higher ( P ≤ 0.05) among fish reared at salinities of 12 ppt or lower (mean 85.6%; range 77.5%–92.5%) compared to those reared at the two highest salinities (42.5% survival at 16 ppt; 5.0% survival at 20 ppt). Thus, although typically found in freshwater habitats, white bass can survive and grow in brackish water. 相似文献
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Background
The creation of minimally redundant tile paths (hereafter MTP) from contiguous sets of overlapping clones (hereafter contigs) in physical maps is a critical step for structural and functional genomics. Build 4 of the physical map of soybean (Glycine max L. Merr. cv. 'Forrest') showed the 1 Gbp haploid genome was composed of 0.7 Gbp diploid, 0.1 Gbp tetraploid and 0.2 Gbp octoploid regions. Therefore, the size of the unique genome was about 0.8 Gbp. The aim here was to create MTP sub-libraries from the soybean cv. Forrest physical map builds 2 to 4. 相似文献206.
Egil AJ Fischer Gert-Jan Boender Gonnie Nodelijk Aline A de Koeijer Herman JW van Roermund 《Veterinary research》2013,44(1):58
Abstracts
Rift Valley fever virus (RVFV) is a zoonotic vector-borne infection and causes a potentially severe disease. Many mammals are susceptible to infection including important livestock species. Although currently confined to Africa and the near-East, this disease causes concern in countries in temperate climates where both hosts and potential vectors are present, such as the Netherlands. Currently, an assessment of the probability of an outbreak occurring in this country is missing. To evaluate the transmission potential of RVFV, a mathematical model was developed and used to determine the initial growth and the Floquet ratio, which are indicators of the probability of an outbreak and of persistence in a periodic changing environment caused by seasonality. We show that several areas of the Netherlands have a high transmission potential and risk of persistence of the infection. Counter-intuitively, these are the sparsely populated livestock areas, due to the high vector-host ratios in these areas. Culex pipiens s.l. is found to be the main driver of the spread and persistence, because it is by far the most abundant mosquito. Our investigation underscores the importance to determine the vector competence of this mosquito species for RVFV and its host preference. 相似文献207.
I Małysz‐Cymborska AJ Ziecik A Waclawik A Andronowska 《Reproduction in domestic animals》2013,48(6):1034-1042
The oviduct plays a crucial role in fertilization, gamete maturation and embryo transport. Prostaglandins are some of the main factors determining its roles. The present study investigated the influence of oestrus synchronization and superovulation on prostaglandins synthesis in the porcine oviduct. Mature cross‐bred gilts after exhibiting oestrous cycles were divided into four groups: I, cyclic; II, inseminated; III, synchronized and inseminated; and IV, superovulated and inseminated. Oviducts were collected on the third day of the oestrous cycle or after insemination and divided into isthmus and ampullary parts. This study demonstrated lower mRNA (in the isthmus and ampulla; p < 0.05, p < 0.001, respectively) and protein prostaglandin endoperoxide synthase 2 expression (in the isthmus; p < 0.001) in gilts treated with human chorionic gonadotrophin/equine chorionic gonadotrophin (hCG/eCG) compared with Group II that were inseminated only. In addition, hCG and eCG treatment decreased mPGES‐1 mRNA levels in Groups III and IV, in both the isthmus (p < 0.01 in III, p < 0.001 in IV) and ampulla (p < 0.001). The prostaglandin E2 content of oviductal tissues was significantly lower in Groups III (p < 0.05) and IV (p < 0.01 in isthmus, p < 0.0001 in ampulla) compared with Group II. mRNA and protein levels of PGFS in Group IV in the oviductal isthmus were higher (p < 0.01) compared with the non‐treated Group II. In effect, the amount of prostaglandin F2α in oviductal tissues of gilts treated with hCG/eCG was significantly elevated (p < 0.001 in isthmus of Groups III and IV; p < 0.05 in ampulla of Group IV). Differential expression of the factors analysed in gilts treated with exogenous gonadotrophins suggests that hCG/eCG stimulation affects prostaglandins synthesis pathway. These changes can alter oviduct functions and in turn affect gamete maturation and fertilization as well as development of embryos and their transport to the uterus. 相似文献
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Azoospermia is a common finding in male alpacas which present for infertility. The challenge is to differentiate azoospermia of testicular origin from non‐testicular origin. In several species, alkaline phosphatase (AP) concentrations in seminal plasma have been used as a diagnostic marker of contributions of the testis and epididymis to the ejaculate. The purpose of this study was to determine whether AP assay could differentiate testicular from non‐testicular azoospermia in male alpacas. An experimental model of bilateral outflow obstruction (pre‐scrotal vasectomy) was used in 22 male alpacas, aged 2–9 years. No reproductive history was available. Animals were submitted for electroejaculation (EE) under general anaesthesia and vasectomy performed. Five weeks later, animals were submitted for EE. Vasectomy was not successful in one animal, which was removed from analysis. AP levels were compared in seminal plasma in the pre‐ and post‐vasectomy samples. The mean ± SEM concentration of AP in pre‐vasectomy seminal plasma was 504.29 ± 166.45 U/l (range 10–2910); the post‐vasectomy levels were 252.48 ± 81.77 U/l (range 0–1640; p = 0.06). In 71.4% of animals, AP levels decreased, varying from 18% to 100% reduction. Results of this study suggest that AP is not produced exclusively by the testis and epididymis in alpacas and that AP assay is not a valid diagnostic test for determination of origin of azoospermia; the gold standard for diagnosis of origin of azoospermia remains testicular biopsy. 相似文献
209.
Keny Vanlalhriatpuia Vanlalnghaka Chhakchhuak Satralkar K Moses SB Iyyer MS Kasture AJ Shivagaje Barnabas J Rajneesh Dilip S Joshi 《Journal of circadian rhythms》2007,5(1):1-11