Effects of adding different concentrations of melatonin (10?7, 10?9 and 10?11 M) to maturation (Experiment 1; Control, IVM + 10?7, IVM + 10?9, IVM + 10?11) and culture media (Experiment 2; Control, IVC + 10?7, IVC + 10?9, IVC + 10?11) were evaluated on in vitro bovine embryonic development. The optimal concentration of melatonin (10?9 M) from Experiments 1–2 was tested in both maturation and/or culture media of Experiment 3 (Control, IVM + 10?9, IVC + 10?9, IVM /IVC + 10?9). In Experiment 1, maturated oocytes from Control and IVM + 10?9 treatments showed increased glutathione content, mitochondrial membrane potential and percentage of Grade I blastocysts (40.6% and 43%, respectively). In Experiment 2, an increase in the percentage of Grade I blastocysts was detected in IVC + 10?7 (43.5%; 56.7%) and IVC + 10?9 (47.4%; 57.4%). Moreover, a lower number and percentage of apoptotic cells in blastocysts were observed in the IVC + 10?9 group compared to Control (3.8 ± 0.6; 3.6% versus 6.1 ± 0.6; 5.3%). In Experiment 3, the IVC + 10?9 treatment increased percentage of Grade I blastocysts with a lower number of apoptotic cells compared to IVM /IVC + 10?9 group (52.6%; 3.0 ± 0.5 versus 46.0%; 5.4 ± 1.0). The IVC + 10?9 treatment also had a higher mRNA expression of antioxidant gene (SOD 2) compared to the Control, as well as the heat shock protein (HSPB 1) compared to the IVM + 10?9. Reactive oxygen species production was greater in the IVM /IVC + 10?9 treatment group. In conclusion, the 10?9 M concentration of melatonin and the in vitro production phase in which it is used directly affected embryonic development and quality. 相似文献
A novel technique was developed to estimate the caudal medial tibial plateau landmark in the face of osteophytosis to improve accuracy in tibial plateau angle measurements. Using this technique, tibial plateau angles were evaluated in 31 normal dogs before and 8 months after right cranial cruciate ligament transection. There was no significant difference in mean tibial plateau angle before or after induction of osteophytosis. Additionally, it was determined that 90% of dogs had a difference of =2 degrees between right and left tibial plateau angles, which was considered symmetrical. 相似文献
Flow conditions, which could not be explained, occurred in the stilling basin and outfall channel of the Feni Regulator sited at the western end of the Feni River closure dam. This regulator controls outflows from the upstream reservoir which supplies irrigation water to Muhuri Project in Bangladesh. Analysis of flood discharge data revealed that the design discharge for the structure was not exceeded; yet abnormal scour occurred in the outfall channel and the brick block rip-rap placed thereon was damaged. A model study was conducted to understand the causes of such unusual local erosion downstream of the stilling basin and to provide answers to two main questions:
-Is potential scour serious in terms of the stability of the structure?
-What protection measures could be taken to stabilize the scour at a safe level?
Using a 1:30 scale model, the probable maximum scour was simulated, and the performance of alternative rip-rap designs including that of the existing one were examined. The results of this study supplemented by field scour data collected during subsequent flood seasons indicated that even if the flow rate through the regulator approaches the design flood discharge, the downstream scour is not likely to extend up to an elevation of ? 10.7 m, a scour level observed in the previous year at a lower discharge. It also showed that the existing rip-rap blocks were marginally undersized and consequently the rip-rap was prone to failure if flow conditions departed from uniform. A suitable method of scour protection downstream of the stilling basin at the regulator exit also evolved from the study. 相似文献
The purpose of this study was to modify and calibrate the CERES-Sorghum water balance model for the dry, high radiation and windy conditions in an area in Southern Italy.
The equation for estimating potential evapotranspiration (E0) was substituted by another one, calibrated in the study site and expressed as a function of equilibrium evaporation and maximum vapour pressure deficit (defined as the difference between the saturation vapour pressure at maximum and at minimum temperatures).
To calibrate the E0 equation included in CERES-Sorghum, two drainage lysimeters, located at the Istituto Sperimentale Agronomico experimental farm, Foggia (Italy), were used to measure weekly evapotranspiration of well-watered, irrigated fescue grass, from 1976 to 1986.
A further drainage lysimeter, located in the same farm and cropped with well-watered grain sorghum (cv. NK 121) was used to calibrate the genetic coefficients input to the modified CERES-Sorghum model during the cropping seasons 1979 and 1980.
Simulated phenological dates (anthesis and maturity), grain yield, LAI, biomass and crop evapotranspiration were then compared with the measured ones in a fourth drainage lysimeter cropped with sorghum.
The modified model simulated grain yield accurately, but simulated daily evapotranspiration did not always match well the observed value, especially early in the crop cycle. Improvements are needed to the model in its simulation of soil evaporation and in the crop response function to temperature. 相似文献
This study evaluated the reproductive performance of gilts inseminated at three intervals before ovulation (0-12, 13-23, 24-30 h) with sperm doses (SD) stored for 0-48 and 96-120 h. A total of 218 PIC Camborough 22 gilts were inseminated once with SD of 1.5 x 10(9) sperms. Pregnant gilts (n = 166) were slaughtered 30.8 +/- 3.7 days after artificial insemination. The number of corpora lutea (CL) and total embryos (TE) was counted. Pregnancy rates (PR) were analysed by chi-square test. TE and embryonic survival (ES), obtained as the ratio between viable embryos and CL, were analysed by GLM procedure (SAS) and mean values were compared by Tukey's test. Pregnancy rate was similar among artificial insemination-ovulation (AIOV) intervals when semen was stored for 0-48 h. However, the lowest PR was observed in the 24-30 h AIOV interval with storage time (ST) of 96-120 h (p < 0.05). There was a significant effect of the interaction between ST and AIOV (p < 0.05) on TE and ES variables. Total embryos and ES did not differ (p > 0.05) among AIOV intervals in ST of 0-48 h. However, gilts inseminated at 24-30 h AIOV interval with ST of 96-120 h showed a reduction of 6.7 embryos (p < 0.05) compared with gilts in the same interval inseminated with semen stored for 0-48 h. ES for the 24-30 h AIOV interval and ST of 96-120 h was lower than that observed in the other groups (p < 0.05). 相似文献
Five groups of laying hens were treated with different gizzerosine doses (0, 2.5; 5.0; 7.5; 10.0 mg/kg/body weight of gizzerosine) daily over a 21-day period to determine the serum concentrations of 1.25-dihydroxycholecalciferol (1,25(OH)2D), total calcium, inorganic phosphorus and magnesium. Blood samples were taken on days 7, 14, and 21 of the experiment. The concentration of 1,25(OH)2D remained unchanged after day 7 in the gizzerosine-treated birds compared to the control group. After 14 days, it was significantly lower in the birds receiving. gizzerosine, compared with the control group. On day 21, 1,25(OH2)D concentrations were also significantly decreased in all 4 gizzerosine-treated groups compared with the control hens. The serum total calcium, inorganic phosphorus and total magnesium concentrations varied significantly, but irregularly, during the period of the study. 相似文献
The apple sawfly Hoplocampa testudinea Klug has recently become a widespread pest in Croatian apple orchards. It causes severe damage in the blooming period due to the fact that infested fruit fall off.This article shows results collected over three years of field research on trap catches of sawflies, the period of laying eggs, the appearance of larvae and detection of damage. In the climate of northwestern Croatia, adult sawfly appear in April during the blooming period of the early apple variety of Idared.By monitoring temperatures from January 1, adults were detected when the thermal constant reached 210 day-degrees. Our observations showed that the larvae emerged when the sum of thermal constants reached ca. 110 day-degrees.The investigation of effective control strategies with insecticides showed high efficacy of thiametoxam (Actara), imidacloprid (Confidor), thiacloprid (Calypso) and betacyfluthrin + oxydemeton-methyl (Enduro) and lower efficacy of phosalone (Zolone), chlorpyrifos-methyl (Reldan), and lambda cyhalothrin (Karate). 相似文献