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61.
狭鳕(Theragra chalcogramma Palas)目标强度的现场测定 总被引:2,自引:2,他引:2
1993年夏季“北斗”号调查船白令海狭鳕(TheragrachalcogrammaPalas)资源声学调查期间,利用计数—积分法对狭鳕的目标强度进行了现场测定。结果表明,平均叉长516cm的狭鳕的平均目标强度为-343dB;以常规的20Logl形式表示,其目标强度与叉长的关系式为TS=20Logl-68.6dB。该测定结果较目前采用的关系式:TS=20Logl-66.0dB低26dB;应用于资源量计算,其估算值将比现估算值高82%。 相似文献
62.
Th.J.M. Schoenmakers G. Flik E.W. Roubos S.E. Wendelaar Bonga 《Fish physiology and biochemistry》1997,17(1-6):347-355
The role of calcium influx through voltage-dependent calcium ion channels in the exocytotic response of single isolated pars intermedia cells from the teleost tilapia (Oreochromis mossambicus) was investigated by means of the whole-cell patch-clamp technique and high resolution electrical measurements. Calcium currents differed from barium currents in several ways: the peak ICa was smaller, the current-voltage relationship for calcium attained its maximum at +10 mV instead of 0 mV, and the inward calcium current inactivated more rapidly. Electron micrographs showed that pars intermedia cells possess dense, encored vesicles with an average diameter of 140 nm. Influx of calcium resulted in an increased cell membrane capacitance (Cm) after the depolarizing period, indicating a fast exocytotic response. Comparison with late recordings revealed the presence of a transient in Cm, presumably attributable to movement of ion channel gates. The average increase in Cm was 13.4 fF, suggesting the fusion of at least 23 vesicles with the plasma membrane during the depolarizing pulse. In contrast to calcium, barium did not support significant exocytosis. We conclude that calcium entry through voltage-dependent calcium channels rapidly leads to the exocytosis of secretory vesicles from tilapia pars intermedia cells. 相似文献
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65.
Estimates of genetic parameters were obtained for body measurement traits of 648 animals at 4 months of age, of 545 at 8 months and carcass traits of 14 972 animals with the use of an animal model by the restricted maximum likelihood procedure. The estimated heritabilities for carcass traits were high (0.41 to 0.54). At 4 months the estimated direct heritabilities for body measurement traits were moderate to high (0.28 to 0.64), except for chest width (0.19); at 8 months they were also moderate to high (0.23 to 0.49), except for chest depth and chest width (0.18 and 0.06, respectively). Maternal heritabilities for all body measurement traits were low at both ages. The results indicate that because of their moderate direct genetic correlations with body measurement traits, carcass weight, rib thickness and subcutaneous fat thickness can be improved; however, rib eye area and beef marbling standard show little such possibility considering their correlation with body measurement traits. 相似文献
66.
Téguia A Mafouo Ngandjou H Defang H Tchoumboue J 《Tropical animal health and production》2008,40(1):5-10
Three hundred and twenty 1-week old ducklings (160 males and 160 females) were used to evaluate the body weight, body parts
and carcass characteristics of the African Muscovy duck. Sexual dimorphism was in favour of the male for all the parameters
throughout the experimental period, however the difference was significant (P < 0.05) only after week 2. The 12-week old male
weighed 1832.0 ± 180.4 g while the female reached only 68.2% of the male weight. Metatarsus diameter, thoracic perimeter,
body length, length of bill, foot and wing in cm were respectively 1.3, 29.5, 57.5, 7.0, 27.1 and 27.8 for the male as compared
with 1.2, 25.8, 51.0, 6.3, 23.3 and 26.9 for the female. Body measurements were highly (P < 0.01) correlated with body weight
for both sexes, however the highest correlation coefficients were obtained with wing length (0.990 and 0.995) and thoracic
perimeter (0.993 and 0.973) for female and male respectively. Live body weight had a linear relationship with both wing length
(R2 = 0.991 and 0.81) and thoracic perimeter (R2 = 0.948 and 0.986) for male and female respectively. The female duck yielded higher percent ready-to-cook carcass (66.3%),
breast (13.6%), liver (2.8%), heart (1.5%) and gizzard (3.8%) as compared to the male (65.0%, 12.0%, 2.5%, 1.1% and 3.4% respectively)
although the difference was not significant (P > 0.05). The male small intestine (185.1 ± 3.4 cm), colon (14.8 ± 1.0 cm) and
caecum (17.9 ± 0.4 cm) were significantly (P < 0.05) longer than that of the female (152.2 ± 1.8, 10.8 ± 0.7 and 14.85 ± 0.6 cm
respectively). 相似文献
67.
68.
伊犁马速步赛成绩与体尺性状的相关性研究 总被引:1,自引:0,他引:1
试验对伊犁马速步赛的体尺性状与比赛成绩之间的相关性进行了研究。测定速步赛中不同比赛项目伊犁马的体高(X1)、体长(X2)、胸围(X3)和管围(X4),计算体长率(X5)、胸围率(X6)和管围率(X7),并用SPSS 18.0软件分析其与比赛成绩之间的相关性。结果表明,在不同的比赛项目中,体尺性状与比赛用时有显著或极显著的相关性(P<0.05;P<0.01)。1000 m速步赛中比赛用时随体高、体长、胸围的增大而减少,随管围、胸围率和管围率的减小而减小;3000 m速步赛中比赛用时随体高、体长的增大而减小,随胸围率和管围率的减小而减小;5000 m速步赛中比赛用时随体高、胸围、体长的增大而减小,随管围率的减小而减小。 相似文献
69.
Michael Sprintsin S. CohenK. Maseyk E. RotenbergJ. Grünzweig A. KarnieliP. Berliner D. Yakir 《Agricultural and Forest Meteorology》2011,151(5):565-574
Effective leaf area index (LAIe) in the semi-arid Pinus halepensis plantation, located between arid and semi-arid climatic zones at the edge of the Negev and Judean deserts, was measured bi-annually during four years (2001-2004) and more intensively (monthly) during the following two years (2004-2006) by a number of non-contact optical devices. The measurements showed a gradual increase in LAIe from ∼1 (±0.25) to ∼1.8 (±0.11) during these years. All instruments, when used properly, gave similar results that were also comparable with actual leaf area index measured by litter collection and destructive sampling and allometric estimates. Because of the constraint of clear sky conditions, which limited the use of the fisheye type sensors to times of twilight, the fisheye techniques were less useful. The tracing radiation and architecture of canopies system, which includes specific treatment of two levels of clumpiness of the sparse forest stand, was used successfully for the intensive monitoring. The mean clumpiness index, 0.61, is considered representative for the specific environment. Finally, the LAIe measurements at the start of each season were used to constrain phenology-based estimates of annual LAIe development, resulting in a continuous course of LAIe in the forest over the five-year period. Intra-seasonal LAIe variation in the order of 10% of total LAIe predicted by the model was also observed in the intensive TRAC measurements, giving confidence in the TRAC system and indicating its sensitivity and applicability in woodlands even with low LAIe values. The results can be important for forest management decision support as well as for use in evaluation of remote sensing techniques for forests at the lowest range of LAIe values. 相似文献
70.
对短秦F1、F2和本地母牛初生、6、12、18、24月龄体尺、体重进行测定,并对其生长发育强度进行对比分析.结果表明,在农村粗放饲养条件下,F2牛初生6、12月龄体重比本地牛分别增加4.3、37.2、35.6kg,相应提高16.6%、28.2%、17.9%;F1牛18、24月龄比本地牛分别增加30.9、47.8kg,提高11.0%和15.6%,改良牛纠正了本地牛的尖斜尻缺点,且生长发育快,增重效果明显,体躯有向肉乳兼用型发展趋势,若加强断奶后的培育,效果更好. 相似文献