Development of the Computer-Aided Design Subsystem

The paper mainly covers the research work of the CAD subsystem. In this subsystem, the menus with icons are used to describe the construction shape, and 2D primitives are pieced together to compose the part to be designed. By using the internal code and building the internal code file to store optimal part constructions, the standardization and rationalization for part design could be achieved.     

The potential effect of iron defortification on iron-deficiency anaemia in the US population

OBJECTIVE: To quantify the potential effect of iron defortification in the USA on iron-deficiency anaemia (IDA). METHODS: Monte Carlo models were built to simulate iron nutrition in the US population. A hypothetical cohort of 15 000 persons from the general population was used in 15-year simulations to compare the prevalence of IDA with and without fortification. RESULTS: With iron fortification, the prevalence of IDA was 2.4% for children aged 3-5 years, 5.4% for women aged 20-49 years, and 0.14% for men aged 20-49 years. The corresponding IDA estimates under iron defortification were 4.5%, 8.2% and 0.46%, respectively. Defortification had little effect on the distribution of iron indicators at or above the 50th percentile within each of these three groups and little effect on the distributions of iron indicators among adult men. CONCLUSION: Iron defortification is likely to increase IDA among children and women of reproductive age, but is not likely to have meaningful effects on the iron status of men or the majority of women and children.     

Phosphorus Removal Mechanisms in Constructed Wetland under Stochastic Intermittent Inflow

Phosphorus removal and is mechanisms by horizontal subsurface(HSSF) constructed wetland to treat simulated runoff under stochastic inflow condition have been investigated based on an experiment study. The results indicate that under stochastic inflow condition and with constant inflow rate of nominal hydraulic retention time of 36 h, the removal rate of the experimental HSSF constructed wetland for total phosphorus(TP) and total phosphorus(DTP) are 59.3% and 29.8％ respectively, and the yearly removal load for TP and DTP are 13.826 and 3.310 g·m-2·a-1 respectively. Removal of phosphorus by macrophytes assimilation is 1.816 g·m-2·a-1, which makes up 13.2％ of the TP removal and 54.85％of the TDP removal in the constructed wetland. It is indicated that macrophytes assimilation is not the main mechanism for the removal of total phosphorus while it has significant effect on the removal of dissolved phosphorus. The main mechanism for phosphorus removal by the constructed wetland are phosphorus retention in sediments accumulated in the substrates and adsorption by the substrates. The yearly phosphorus retention in sediments accumulated in the substrates is 5.372 g·m-2·a-1, which contributes to 38.9% of the total phosphorus removal. And yearly phosphorus adsorption by the substrates is 6.640 g·m-2·a-1 , which contributes to 48.0% of the total phosphorus removal.     

Effect of daidzein on egg-laying performance in Shaoxing duck breeders during different stages of the egg production cycle

The effect of a phyto-oestrogen, daidzein, on the laying performance of Shaoxing female ducks was examined in three experiments performed at different stages of the egg production cycle. Egg-laying rate, egg weight, egg composition, feed conversion ratio, hatchability characteristics of eggs and body weight, ovary and oviduct weight, as well as changes in serum concentrations of T3, T4 and E2 were recorded as response criteria. In the first experiment, 68 young ducks, 100 d of age, were given a basal diet (maize-soybean meal) with or without 3 mg of daidzein/kg diet for 42 d. Daidzein did not affect the onset of lay but apparently decreased egg-laying rate and mean egg weight as well as the feed conversion ratio. In the second experiment, 240 breeding ducks, 402 d of age, were allotted at random to three groups and given the basal diet containing daidzein at 0 (control), 3 (Da1) and 5mg/kg (Da2) for 35d. Egg-laying rate, mean egg weight and feed conversion ratio increased in both Da1 and Da2 groups. However, an adverse effect of daidzein on fertility and hatchability was observed. In the third experiment, 320 breeding ducks, 415 d of age, were fed on the basal diet with or without 5mg of daidzein/kg diet for 63 d. Egg-laying rate increased by 7.7%, average egg weight tended to increase, whereas yolk/albumen ratio decreased. Daidzein-treated ducks had higher body weight and oviduct weight compared with their controls. Elevated plasma T4 and E2 concentrations accompanied these phenotypic changes, but serum T3 was not affected. It is suggested that daidzein exerts divergent effects on the egg-laying performance of Shaoxing ducks under different physiological conditions and this action is dose-dependent. The changes in circulating E2 imply possible participation of endogenous oestrogen in the mechanism of daidzein action.     

The effects of nitric oxide donors on the sporulation of Eimeria tenella oocysts

Nitric oxide (NO) is involved in many physiological processes including regulation of blood pressure, immune response, and neural communication. The effects of NO donors on the sporogony of Eimeria tenella oocysts and the blocking effects of NO scavenger, hemoglobin (Hb), against NO donors were investigated in this study. The results showed that the sporulation of oocysts could be completely inhibited by acidic sodium nitrite (NaNO2), S-nitroso-glutathione (GSNO) or S-nitroso-N-acetyl-dl-penicillamine (SNAP) in profound dose-dependent and time-dependent manners, and the inhibiting process was irreversible and not affected by feces of chickens. However, not all NO donors in this study, such as sodium nitroprusside (SNP), demonstrated above-mentioned effect. The NO scavenger Hb could significantly prevent the detrimental effects of NO donors on the sporogony of oocysts in a dose-dependent manner. At present, the inhibiting mechanism of NO donors on the sporulation of oocysts was still unclear.     

目前我国猪瘟的流行现状及防控策略

国家对猪瘟的预防和控制一直都十分重视,尽管我国很早就研制成功了猪瘟兔化弱毒疫苗,并在预防猪瘟的发生中起到了重要作用,但由于近年来猪瘟的流行和发病特点发生了很大的变化,其流行形式从频发的大流行转变为周期性、波浪形的地区性散发性流行,出现了所谓的非典型猪瘟、温和型猪瘟和无名高热综合征等,以及在出现上述种种迹象的地区和猪场往往同时表现无法解释的免疫失败。当前,猪瘟仍是世界养猪业的一大威胁,给养猪业造成了严重的经济损失。本文主要介绍了猪瘟的传播途径、近年来猪瘟在流行时间、流行形式、流行病型的变化以及当前猪瘟的不同表现症状、病理变化及防制策略,为猪瘟的免疫监测及防控体系的建立提供参考。     

Additive Effects of QTLs/Genes on Rice Grain Size Traits Revealed by Genetic Comparisons

<正>Grain size is controlled by many QTLs and/or genes. Despite intensive study, the genetic interactions between these QTLs/genes remain largely unclear. We previously found that the japonica large-grain rice cultivar TD70 with 1000-grain weight of 68.6 g carries superior alleles at the loci GW2, GS3, q GL3, GS5 and GW8, all of which are known to control grain size, while the indica rice variety Kasalath with 1000-grain weight of 19.1 g has normal alleles at these loci. In this study,