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31.
FA Street-Perrott Y Huang RA Perrott G Eglinton P Barker LB Khelifa DD Harkness DO Olago 《Science (New York, N.Y.)》1997,278(5342):1422-1426
Carbon-isotope values of bulk organic matter from high-altitude lakes on Mount Kenya and Mount Elgon, East Africa, were 10 to 14 per mil higher during glacial times than they are today. Compound-specific isotope analyses of leaf waxes and algal biomarkers show that organisms possessing CO2-concentrating mechanisms, including C4 grasses and freshwater algae, were primarily responsible for this large increase. Carbon limitation due to lower ambient CO2 partial pressures had a significant impact on the distribution of forest on the tropical mountains, in addition to climate. Hence, tree line elevation should not be used to infer palaeotemperatures. 相似文献
32.
33.
VS Chouhan RP Panda VP Yadav V Babitha FA Khan GK Das M Gupta SS Dangi G Singh S Bag GT Sharma B Berisha D Schams M Sarkar 《Reproduction in domestic animals》2013,48(5):810-818
The aim of this study was to document the expression and localization of VEGF system comprising of VEGF isoforms (VEGF 120, VEGF 164 and VEGF 188) and their receptors (VEGFR1 and VEGFR2) in buffalo corpus luteum (CL) obtained from different stages of the oestrous cycle. Real‐time RT‐PCR (qPCR), Western blot and immunohistochemistry were applied to investigate mRNA expression, protein expression and localization of examined factors. In general, all the components of VEGF system (the VEGF isoforms and their receptors) were found in the water buffalo CL during the oestrous cycle. The mRNA as well as protein expression of VEGF system was highest during the early and mid‐luteal phase, which later steadily decreased (p < 0.05) after day 10 to reach the lowest level in regressed CL. As demonstrated by immunohistochemistry, VEGF protein was localized predominantly in luteal cells; however, VEGFR1 and VEGFR2 were localized in luteal cells as well as in endothelial cells. In conclusion, the dynamics of expression and localization of VEGF system in buffalo corpora lutea during the luteal phase were demonstrated in this study, indicating the possible role of VEGF system in the regulation of luteal angiogenesis and proliferation of luteal as well as endothelial cells through their non‐angiogenic function. 相似文献
34.
M Pande GK Das FA Khan M Sarkar JK Prasad MC Pathak H Kumar 《Reproduction in domestic animals》2013,48(1):79-84
The effect of uterine infection on size and follicular fluid composition of the largest follicle was studied in buffalo. Reproductive tracts were collected from 102 graded Murrah buffaloes at an abattoir. Uterine infection was diagnosed by physical examination of uterine mucus, white side test and uterine cytology. Samples with pus‐containing mucus, positive reaction on white side test and/or >5% neutrophils were considered to be positive for uterine infection. Diameter of the largest follicle was measured, and follicular fluid was aspirated and assayed for nitric oxide (NO), ascorbic acid (AA), cholesterol, oestradiol (E2) and progesterone (P4). Infected buffaloes had smaller‐sized (p < 0.0001) largest follicles than non‐infected buffaloes. Follicular fluid collected from the largest follicle in infected buffaloes had greater (p < 0.0001) NO and P4 concentrations coincident with lesser AA (p < 0.001), cholesterol (p < 0.0001) and E2 (p < 0.0001) concentrations. Results indicated that uterine infection has an inhibitory effect on growth of the largest follicle in buffalo. The changes in follicular fluid composition in infected buffaloes suggest that the direct effect of uterine infection on ovarian function may be mediated through an alteration in the follicular microenvironment. Greater NO and lesser AA concentrations in the follicular fluid of infected animals are novel findings. 相似文献
35.
Stem taper equation analysis for Larix kaempferi species in the Central Region of South Korea 总被引:1,自引:0,他引:1
Taper equation was developed to predict diameters at specific height for Larix kaempferi species in the Central Region of South Korea. The sampled trees that were collected through destructive sampling ranged from 0.60 to 47.90 cm DBH with total height ranging from 2.00 to 33.00 m. The dataset was randomly split into two: 80% for initial model fitting and 20% for model validation. The combined that means 100% dataset was used for final model fitting. Statistics of fit were used as criteria, including the coefficient of determination (R2), standard error of the estimate (SEE), bias (ē), the absolute mean difference (AMD), and the Akaike information criterion (AIC) values and weight (AICw), with a rank analysis being applied. Initial model fitting utilized a total of nine taper equations, with the three segmented taper equations and another three non-segmented determined for model validation and final model fitting. Kozak02 equation, which had not yet been evaluated for L. kaempferi species, indicated the best performance for the species in the Central Region of South Korea. Upon comparison, the ability of this study to predict diameters at specific height and stem volume was better than the existing taper equation for L. kaempferi in South Korea. 相似文献
36.
FA Bruna EG De Di Nasso M Soaje RP Deis RW Carón 《Reproduction in domestic animals》2010,45(5):796-802
The role of opioid peptides in the secretion of oxytocin (OT) and prolactin (PRL) induced by sucking was studied in goats. Seven goats were isolated with their kids (four singletons and three twins) in individual corrals 3–4 weeks after parturition. On day 1 of the experiment, the kids were separated from the does for 7 h and were weighed before and 15 min after being reunited with their mothers to assess the amount of milk obtained by sucking. The does were blood‐sampled 10 min before and at the end of the sucking period. On day 2, a similar protocol was followed, but naloxone was given immediately after the first blood sample. On day 3, the protocol was repeated but saline vehicle was injected instead of naloxone. On day 5, the naloxone experiment was repeated as on day 2. Milk ejection was evaluated as the difference in the weight of the kids before and after sucking for 15 min, and the maternal serum levels of OT and PRL were measured by radioimmunoassay. A significant decrease in the weight gain of the kids was obtained when the mothers were treated with naloxone on day 2. Consistently, serum levels of OT and PRL induced by sucking were significantly reduced; indicating that sucking‐induced OT secretion for milk ejection in lactating goats is facilitated by opioid peptides. In a second experiment performed in the same animals 10 days later, the administration of OT, immediately after naloxone administration, prevented the decrease in the weight gain induced by naloxone, suggesting that the effect of the opioid antagonist on milk ejection in goats is a result of a reduced OT secretion. The results of this study confirm the importance of sucking‐induced OT secretion for milk ejection in lactating goats, and indicate that OT and PRL secretion are regulated by opioid peptides in this species. 相似文献
37.
利用26对黄牛微卫星引物,对分别来自云南省泸水县凤凰山大额牛保种区和贡山县独龙野牛种源保护基地的2个大额牛群体进行遗传变异分析,研究其群体内的遗传变异和群体间的遗传分化。结果共检测到105个等位基因,每个座位的等位基因数从2~6不等,所有座位平均等位基因数、平均有效等位基因数、平均期望杂合度、平均多态信息含量分别为4.0385±0.9999,3.1393±0.9507,0.6490±0.1246和0.5904±0.1334,表明大额牛群遗传多样性比较丰富。F统计量、基因流、Nei氏遗传距离和遗传相似系数等值反映出两个群体遗传差异较小,遗传分化不明显,遗传一致性较大。 相似文献
38.
Pedraza-Beltrán P Estrada-Flores JG Martínez-Campos AR Estrada-López I Rayas-Amor AA Yong-Angel G Figueroa-Medina M Nova FA Castelán-Ortega OA 《Tropical animal health and production》2012,44(2):329-336
Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients
to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively
inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate
the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous
crossed Holstein–Brown Swiss–Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion
of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results
showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion
of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate
without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced
in 20% by the inclusion of coffee pulp. 相似文献
39.
曾宪玮 ZENG XIAN WEI 彭德忠 PENG DE ZHONG 邹文生 ZOU WEN SHENG 彭洁贤 PENG JIE XIAN 陈祥发 CHEN XIANG FA 陈琨 CHEN KUN 《江西林业科技》2001,(6):23-25
通过对宜丰县云峰尖林场毛竹示范林的经营状况进行调查,分析了其经济效益、社会效益、生态效益。 相似文献
40.