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211.
The effect of four concentrations (0.1, 1, 10, and 100 ppm) of Sevin on the rate of uptake of two sugars (glucose and fructose) and an aminoacid (tryptophan) by the intestine of the fresh water snake-head fish,Channa punctatus has been investigated. All four concentrations of the pesticide decreased the rate of transport of the three nutrients. No direct relationship could be established between the concentration of Sevin in the medium and decrease in the rate of transport of nutrients, although, increase in the concentration of Sevin reduced the absorption of nutrients by the intestine to a greater extent. Experiments conductedin vivo andin vitro showed that in both cases the pesticide decreased the brush border enzyme activity. 相似文献
212.
Tahir Karasahin Hasan Alkan Fatma Satilmis Sukru Dursun Huseyin Erdem 《Reproduction in domestic animals》2021,56(12):1555-1561
This study aimed to determine the effect of flunixin meglumine treatment during and after the transfer of in vivo produced embryos to Angus (cows) and Holstein (cows and heifers) breeds of cattle on pregnancy rate. Holstein cows were used as donors in the study. A double dose of prostaglandin F2α was administered to the recipient animals for synchronization. Uterine flushing was performed in donors on day 7 after artificial insemination. A total of 295 transferable embryos were obtained. These embryos were transferred to Angus cows (n = 85), Holstein heifers (n = 80) and Holstein cows (n = 130). After the transfer, these animals were divided into three subgroups. The first subgroup (TI) was administered flunixin meglumine during embryo transfer, and the second subgroup (TII) was administered flunixin meglumine both during embryo transfer and on days 8 and 9 after the transfer. The third subgroup (TIII) was not administered anything and it was considered the control group. Pregnancy examination of the recipients was performed on days 30–35 after the transfer using real-time ultrasonography. The pregnancy rates after embryo transfer were found to be 43.52% in Angus cows, 42.5% in Holstein heifers, and 24.61% in Holstein cows (p < .05). When the animals were not classified according to breed, the pregnancy rates in subgroups TI, TII and TIII were found to be 29.29%, 45.10% and 29.79%, respectively (p < .05). In addition, the pregnancy rates were higher in TII and TIII subgroups of Angus cows and Holstein heifers compared to that of Holstein cows (p < .05). As a result, the pregnancy rates obtained after embryo transfer in Angus cows and Holstein heifers were found to be higher than that in Holstein cows. In addition, it was concluded that the administration of flunixin meglumine during and during/after embryo transfer has a positive effect on pregnancy rates in Angus cows and Holstein heifers. 相似文献
213.
Zhao Ben Adama Traore Ata-Ul-Karim Syed Tahir Guo Yan Liu Zhandong Xiao Junfu Liu Zugui Qin Anzhen Ning Dongfeng Duan Aiwang 《Precision Agriculture》2022,23(3):748-767
Precision Agriculture - Accurate and timely assessment of crop water status is imperative for in-season irrigation scheduling in crop production. The canopy water stress index and water deficit... 相似文献
214.
The load-carrying capacity of a timber structure is highly dependent on the strength of its connections. Very limited information exists on the thermal degradation, or the properties at elevated temperatures, of such connections. This insufficient information is one of the major impediments for modeling elevated temperature performance for wood-frame structures. The objective of this study was to characterize thermal degradation of yield load capacity of single-shear nailed connections between wood and oriented strand board (OSB) as a function of time and temperature. The mechanism of degradation was explained using first order kinetics. Using the principles of time–temperature superposition (TTS), predictive models for connection capacity degradation were developed. A total of 450 wood-to-OSB connections were tested laterally after exposure to nine different elevated temperature regimes. The degradation of yield load strength over time occurred at a constant linear rate. Temperature dependence of this rate was modeled using the Arrhenius activation energy theory. Using Arrhenius activation energy theory and principles of TTS, a master curve was developed to predict the performance of connections after exposure to a temperature of 150°C. The predictions matched well with independent experimental observations. The master curve developed using TTS provides predictive estimates of residual capacity in a connection as well as its failure times. 相似文献
215.
Transfer of Heavy Metals from Soils to Vegetables and Associated Human Health Risks at Selected Sites in Pakistan 总被引:1,自引:0,他引:1
Zahir Ur REHMAN Sardar KHAN Mohammad Tahir SHAH Mark L. BRUSSEAU Said Akbar KHAN Jon MAINHAGU 《土壤圈》2018,28(4):666-679
Contamination of the food chain with heavy metals is considered as one of the major environmental pathways of human exposure to metals leading to potential health risks. This study aimed to investigate the concentrations of heavy metals such as copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni), and manganese (Mn) in agricultural soils and food crops (fruit, leaf, and root vegetables), and their associated health risks to the local population in selected southern districts of Khyber Pakhtunkhwa Province, Pakistan. The concentrations of the selected metals in soil varied over a wide range, in the following decreasing order: Mn > Zn > Cr > Ni > Cu. The bioaccumulation of metals in vegetables was within the permissible risk limits, except for Cr which showed higher contamination in all the tested food crops. The trend of metal transfer factors for different vegetables was in the order of Cu > Ni > Cr > Mn > Zn, while the calculated daily intake of metals (DIM) in adults and children through consumption of food crops was in the decreasing order of Mn > Zn > Ni > Cr > Cu. The health risk index (HRI) values for the heavy metals for both adults and children were less than 1. Therefore, no significant health risk is anticipated for the local consumers through ingestion of these food crops. 相似文献