Determination of genotoxicity of Fenaminosulf by Allium and Comet tests

Genotoxic effects of Fenaminosulf, fungicide and micro-biocide, were examined by using mitotic index (MI), mitotic phase, and Comet assay on the root meristem cells of Allium cepa. In the Allium root growth inhibition test, EC₅₀ value was firstly determined as 25 ppm and, 12.5 (0.5 × EC₅₀), 25 (EC₅₀) and 50 (2 × EC₅₀) ppm concentrations of Fenaminosulf were introduced to onion tuber roots. Distilled water was used as a negative control. All obtained data were subjected to statistical analyses by using SPSS 15.0 for Windows software. For comparison purposes, Duncan multiple range tests by using one-way analysis of variance (ANOVA) were employed and p < 0.05 was accepted as significant value. While MI (except in 24 h at 12.5 and 50 ppm) and prophase index increased, metaphase, anaphase and telophase indexes decreased in all concentrations compared to control at each exposure time. A significant increase in DNA damage was also observed at the concentration of 25 ppm in 24 h, 25 and 50 ppm in 96 h by Comet assay.     

基于振动烈度的拖拉机整机装配质量评价方法研究

为了实现拖拉机整机出厂终检时整机装配质量快速评价的目的,提出了一种基于机械振动烈度评价拖拉机整机装配质量的方法。以奔野484-2轮式拖拉机为研究对象,测试了怠速状况下的拖拉机前托架、发动机、离合器及变速箱等部位的振动烈度,结果表明:振动烈度可以作为评价拖拉机整机装配质量的方法,也可以作为局部评价拖拉机装配质量的依据。     

Quantitative Histomorphology of Liver Growth in Sheep at Prenatal and Postnatal Stages

This study was carried to determine quantitative histomorphologically on the development of the liver of sheep in prenatal and postnatal stages, and to prove the relationship between functional and structural differentiation of liver. There were more blood cells than hepatocytes, and haemotopoieisis was the primary function of the liver in the first half of gestation. As observed in the fetal stages bile ducts and Kiernan areas are formed from the 12th week. The distance between the two adjacent central veins was 401.2 ? 20.8 micron in the fetuses and 629.77 ? 34.7 micron in the lambs, while rising in the adult to 740 + 14.35 micron. This increase was directly proportional to age. The average diameter of sheep hepatocyte and nuclei, and the ratio between the diameters of nuclei and their hepatic cells were compared according to the prenatal and postnatal stages, and the difference between these stages was found to be statistically significant (P < 0.05). This difference was sourced from adult sheep. The number of hepatocytes per unit area were 107.48 ? 6.63, 133.6 ? 7.01, 100.84 ? 6.63 in the fetus, lamb and adult liver of sheep, respectively, and the differentia that earned statistical importance was sourced from the young stages. The number of ductus biliferi was 2.75 ? 0.47 in the fetuses, however, this had risen to 5.8 ? 0.6 and 6.8 ? 0.37 respectively in the lambs and adult sheep. The portai lobule areas rose according to the age and were 0.17796 ? 0.00086 mm² and 2.022650 ? 0.0097 mm² respectively in the lambs and adult sheep and the differentia between young and adult sheep was statistically important (P < 0.05).     

Substitution of plant protein for fish meal in the diet of laying ducks

Fish meal is a good source of protein feed that can be used to get a high production yield even though it has a comparatively higher price. Plant protein has been found to substitute for fish meal without any adverse effect on production as well as helping to reduce feed cost. Moreover, it is not necessary for a level more than 5% fish meal in the diet of laying ducks. One type of plant protein is soybean meal, considered one of the most valuable sources of vegetable protein and whose amino acid composition is comparable to that of milk protein. In a soybean meal, the first limiting amino acid is methionine. Soybean meal can substitute for fish meal in laying ducks' diet but supplementation of methionine and lysine is recommended. Since sesame meal is rich in methionine and agrinine, 50% of soybean meal can be replaced by sesame meal without adverse effects. Leucaena leaf meal is also a valuable source of protein (26%) and carotenoids but it also has a toxic amino acid (mimosine). However, soaking leucaena leaf meal in water can remove the toxic amino acid and can be used, together with added methionine and lysine, as 10% of the diet for laying ducks.     

Comparative efficacy of trash fish versus compounded commercial feeds in cage aquaculture of Asian seabass (Lates calcarifer) (Bloch) and tiger grouper (Epinephelus fuscoguttatus) (Forsskål)

Trash fish/low valued fish is still the most commonly used feed in marine cage culture in Asia. Use of trash fish is controversial with regard to the sustainability of the farming practices, and related issues on environmental degradation. In this study, the results of farm based trials on Asian seabass (Lates calcarifer) and tiger grouper (Epinephelus fuscoguttatus) to evaluate the efficacies of the use of commercial pellet feed in comparison to trash fish/low valued fish in marine cages in Thailand are presented. In spite of the variations observed in each of the farm sites, the results indicate that the overall growth performances and fish survival rates between the two feed types were similar, for both species. However, better cost‐benefit and resource use were recorded for fish reared on trash fish/low valued fish. No significant differences were observed in water quality parameters, dissolved oxygen, transparency and ammonia, between sites where pellet or trash fish were used, inside and outside the cages and for both species. The results of the present study are discussed in the light of the current controversies on the use of trash fish/low valued fish in marine cage culture.