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11.
We compared a wide range of environmental data with measures of recruitment and stock production for Japanese sardine Sardinops melanostictus and chub mackerel Scomber japonicus to examine factors potentially responsible for fishery regimes (periods of high or low recruitment and productivity). Environmental factors fall into two groups based on principal component analyses. The first principal component group was determined by the Pacific Decadal Oscillation Index and was dominated by variables associated with the Southern Oscillation Index and Kuroshio Sverdrup transport. The second was led by the Arctic Oscillation and dominated by variables associated with Kuroshio geostrophic transport. Instantaneous surplus production rates (ISPR) and log recruitment residuals (LNRR) changed within several years of environmental regime shifts and then stabilized due, we hypothesize, to rapid changes in carrying capacity and relaxation of density dependent effects. Like ISPR, LNRR appears more useful than fluctuation in commercial catch data for identifying the onset of fishery regime shifts. The extended Ricker models indicate spawning stock biomass and sea surface temperatures (SST) affect recruitment of sardine while spawning stock biomass, SST and sardine biomass affect recruitment of chub mackerel. Environmental conditions were favorable for sardine during 1969–87 and unfavorable during 1951–67 and after 1988. There were apparent shifts from favorable to unfavorable conditions for chub mackerel during 1976–77 and 1985–88, and from unfavorable to favorable during 1969–70 and 1988–92. Environmental effects on recruitment and surplus production are important but fishing effects are also influential. For example, chub mackerel may have shifted into a new favorable fishery regime in 1992 if fishing mortality had been lower. We suggest that managers consider to shift fishing effort in response to the changing stock productivity, and protect strong year classes by which we may detect new favorable regimes.  相似文献   
12.
The osteopontin gene may influence the fertility of water buffaloes because it is a protein present in sperm. The aim of this work was to identify polymorphisms in this gene and associate them with fertility parameters of animals kept under extensive grazing. A total of 306 male buffaloes older than 18 months, from two farms, one in the state of Amapá and the other in the state of Pará, Brazil were used in the study. Seven SNPs were identified in the regions studied. The polymorphisms were in gene positions 1478, 1513 and 1611 in the region 5′upstrem and positions 6690, 6737, 6925 and 6952 in the region amplified in intron 5. The SNPs were associated with the traits, namely scrotal circumference, scrotal volume, sperm motility, sperm concentration and sperm pathology. There were significant SNPs (p < 0.05) for all the traits. The SNP 6690 was significant for scrotal circumference, sperm concentration, sperm motility and sperm pathology and the SNP 6737 for scrotal volume. The genotype AA of SNP 6690 presented the highest averages for scrotal circumference, sperm concentration and motility and the lowest total number of sperm pathologies. For the scrotal volume trait, the animals with the largest volume were correlated with the presence of the genotype GG of SNP 6737. These results indicate a significance of the osteopontin gene as it seems to exert a substantial influence on the semen production traits of male buffaloes.  相似文献   
13.
Electrophoresis in polyacrylamide gel of homogenates of various organs from the mouse yields five major lactic dehydrogenase bands. If the gels are treated with beta-mercaptoethanol, subsequent electrophoresis produces 15 bands which show lactic dehydrogenase activity. This could be explained if one molecule of nicotinamide adenine dinucleotide (coenzyme) is attached to each of the monomeric subunits of lactic dehydrogenase and if mercaptoethanol can remove the coenzyme only from the muscle type. This is consistent with the hypothesis that intact lactic dehydrogenase is a tetramer.  相似文献   
14.
Heart rate as a measure of adaptation to stress in cattle   总被引:1,自引:0,他引:1  
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15.
Amphotericin B-induced synovitis of the left tarsocrural joint was used to create a grade 3 of 4 lameness in 11 horses. Caudal epidural catheters were placed and advanced to the lumbosacral region. Baseline heart and respiratory rates were recorded and horses were videotaped at a walk and trot. Morphine sulphate (0.2 mg/kg) and detomidine hydrochloride (30 μg/kg) were administered to treated horses (n = 8) through the epidural catheter; an equivalent volume of physiologic saline solution was administered to control horses (n = 3) through the catheter. At hourly intervals after epidural injection for a total of 6 hours, heart and respiratory rates were recorded, and horses were videotaped walking and trotting. At the end of the observation period, video recordings were scrambled onto a master videotape. Lamenesses were scored by three investigators unaware of group assignment or treatment time. Lameness scores, heart rates, and respiratory rates were compared between groups using repeated measures analysis of variance. There was a significant decrease in lameness score after treatment with epidural morphine and detomidine ( P =.0003); average lameness scores of treated horses were less than grade 1 at each hourly observation for 6 hours after drug administration. Early in the observation period, heart rates significantly increased in control horses and decreased in treated horses ( P =.03). A similar trend occurred for respiratory rates ( P =.07). Results of this study demonstrate that epidural administration of a combination of morphine and detomidine is capable of providing profound hindlimb analgesia in horses.  相似文献   
16.
Accurate detection of oestrus is important for artificial insemination. The aim of this study was to identify oestrous‐specific bovine cervical mucus proteins that could be used to determine the optimal time for artificial insemination. Non‐oestrous and controlled internal drug release (CIDR)‐induced oestrous‐stage mucus proteins were purified and subjected to surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry, sodium dodecyl sulphate polyacrylamide gel electrophoresis and MALDI‐TOF/TOF. Among differentially expressed proteins, lactoferrin (LF) and glutamate receptor‐interacting protein 1 (GRIP1) showed a twofold increase during the CIDR‐induced oestrous stage compared to the levels in non‐oestrous stage in bovine cervical mucus. The RT‐PCR, Western blotting and immunohistochemistry results showed that LF and GRIP1 expression was significantly increased during the oestrous stage in the uterus. This study demonstrated that bovine LF and GRIP1 exist during the oestrous stage, but not during the non‐oestrous stage, suggesting that cervical mucus LF and GRIP1 are useful oestrous detection markers in cattle.  相似文献   
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18.
The cardiorespiratory effects of four opioid-tranquilizer combinations were evaluated in six dogs. The four combinations were administered to each dog in a randomized order. Buprenorphine (BUP; 0.01 mg/kg IV) or oxymorphone (OXY; 0.1 mg/kg IV) was followed in 10.4 ± 1.3 minutes by midazolam (MID; 0.3 mg/kg IV) or acepromazine (ACE; 0.05 mg/kg IV). Nalbuphine (0.16 mg/kg IV) was administered 94.1 ± 2.3 minutes after the tranquilizer was given. Heart rate (HR) and mean arterial blood pressure (MAP) decreased significantly ( P < .05) after each combination. MAP was significantly lower with combinations using ACE. Most dogs panted after opioid administration; this was associated with increased minute volume (VM) and decreased tidal volume (VT). After administration of the tranquilizer, mean breathing rate and VM index (VMI) were significantly lower with ACE combinations. There were no significant changes in pH and blood gas variables after BUP-ACE. The other three combinations were associated with significant ( P < .05) decreases in pH and increases in Paco2. Mean Pao2 decreased significantly ( P < .05) with OXY combinations but not BUP combinations. Dysrhythmias (atrial or ventricular escape complexes) were seen with each combination. HR increased significantly ( P < .05) after nalbuphine in dogs receiving OXY, but not BUP. Dogs receiving OXY became more alert after nalbuphine on six of 12 occasions, whereas dogs receiving BUP became less alert on six of 12 occasions. OXY-ACE provided the most chemical restraint/sedation and BUP-MID provided the least.  相似文献   
19.
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