Supplemental protein plus ruminally protected methionine and lysine for primiparous beef cattle consuming annual rye hay

Primiparous beef cows (n = 35 Bos taurus, average initial BW of 498 kg) were allotted to treatments in a split-plot designed experiment to determine the effects of supplemental ruminally protected amino acids on cow and calf productivity and metabolic changes in the cows. Cows were fed chopped annual rye hay at 1.5% of BW. The following treatments were used: 1) .8 kg soybean hulls, 1.4 kg ground corn, .6 kg soybean meal (CON); 2) 1.4 kg ground corn, 1.4 kg soybean meal (PRO); 3) PRO plus ruminally protected methionine and lysine (supplied 5 and 10 g, respectively; PRO1); and 4) PRO with twice the level of ruminally protected amino acids in PRO1 (PRO2). Cow weight gain was not different (P > .26) among treatments and averaged 1.2 kg/d for the 45 + 6 d before parturition. After parturition, cow weight gain did not differ (P > .47) between CON and PRO treatments, but it decreased quadratically (P < .01) with increasing level of ruminally protected amino acids. Total milk yield, protein, and fat (4 h) were greater (P < .05) for cows consuming PRO supplements than for CON, whereas CON cattle tended (P = .11) to lose less body condition. Total milk protein showed a quadratic increase (P < .05) in response to level of ruminally protected amino acids that was the inverse of the quadratic response noted for cow weight gain. Serum urea N concentration was greater (P = .07) for cattle consuming additional protein. Metabolic hormones were not affected (P > .18) by dietary treatment, but they responded (P < .05) to changes in physiological state. Supplements with additional protein supported greater (P = .0001) milk urea N concentration and output. Milk urea N concentration increased (P < .05) and milk IGF-I decreased (P < .05) as the lactation period progressed. The measurement of CON and PRO diets revealed that supplements with additional soybean meal had greater (P < .05) DM and N degradation; the extent of forage DM and NDF degradation was similar (P > .05) among treatments. Production shifted away from body weight gain to increased milk protein production when daily supplementation of ruminally protected methionine and lysine increased from 5 and 10 to 10 and 20 g, respectively. This shift in production was not reflective of changes in the metabolic regulators measured.     

QJ系列羊肚菌品种氨基酸特征评价

以自主选育的QJ系列羊肚菌品种为试验材料,通过检测子实体氨基酸组成及含量,明确氨基酸营养特征。使用联合国粮食及农业组织（Food and Agriculture Organization of the United Nations,FAO）/世界卫生组织（World Health Organization,WHO）标准模式谱、系统聚类分析和主成分分析等方法对氨基酸进行全面评价。结果表明,系列品种总体表现为氨基酸种类丰富、必需氨基酸种类齐全的基本特征。其中标准模式谱评价可知QJ-10、QJ-12 明显优于其他品种,QJ-9 是系列品种中必需氨基酸营养价值最高的品种。聚类分析将系列品种分为4 类,第一类为氨基酸总量高、呈味氨基酸丰富,包括QJ-3、QJ-6、QJ-8 和QJ-9。主成分分析结果表明,各品种氨基酸综合得分由高到低为QJ-6、QJ-8、QJ-9、QJ-12、QJ-3、QJ-7、QJ-10、QJ-2,其中QJ-6 羊肚菌综合得分最高,为0.38。该研究结果为进一步丰富QJ系列羊肚菌基础研究数据,为羊肚菌品种的差异化开发提供参考。     

商业项目集中餐饮区排油烟系统的设计与思考

本文以无锡某大型商场内餐饮集中区域的排油烟系统设计为依据,从餐饮区域的划分、餐饮招商过程、排油管道系统的设置、排油烟系统设备的选择及商业设施集中管理等开发商项目管理问题出发,介绍餐饮集中商业排油烟系统的设计、建设经验,以期为大型商场、商业街等饮食建筑的建设提供参考。     

芳纶橡胶输送带的接头强度研究

针对芳纶橡胶输送带接头强度保持率低的问题,本研究以国内外芳纶橡胶输送带接头方案为基础,采用指型插接方案,系统性地探究了指型长径比、贴胶厚度、织物增强层结构等因素对接头强度的影响。实验证明接头强度随长径比的增大而升高;贴胶厚度在1mm时接头强度达到最大,此后接头强度随贴胶厚度的增加而降低;织物增强层沿经向放置的接头强度提高87%,接头强度保持率达到带体强度的60%。     

基于自聚焦透镜的吸收型光纤气体传感器气室设计

基于气体分子红外吸收光谱的原理,设计了基于自聚焦透镜的透射式气室结构。利用自聚焦透镜作为光纤准直透镜和聚焦透镜,应用于透射型气室,并提出了在透射式气室中将多对自聚焦透镜组串联用以增加吸收光程的方法,用该方法可以明显提高气室的检测灵敏度。基于自聚焦透镜的透射式气室成功地应用于基于谐波检测技术的吸收型光纤气体传感器系统中,获得较好的检测效果。     

Low temperature age hardening in U-13 at.% Nb: An assessment of chemical redistribution mechanisms

Low temperature aging (<350 °C) of U-13 at.% Nb martensite results in increased strength levels accompanied by significant ductility loss. To determine the decomposition mechanism(s) responsible for these mechanical property changes, atom probe tomography was used to examine the niobium and impurity distributions after aging at 200 or 300 °C for times ranging from 2 h to 70 days. No patterns of niobium or impurity atoms were observed that would indicate segregation to the martensitic twin interfaces, making this hardening mechanism unlikely. Phase separation into roughly equiaxed regions of high and low niobium concentration was clearly observed after aging at 300 °C for 70 days. However, only subtle niobium concentration changes were observed after aging at 200 °C relative to the as-quenched condition, indicating that conventional phase separation is an unlikely explanation for the dramatic mechanical property changes at 200 °C. Therefore, consideration of aging mechanisms other than segregation and phase separation may be warranted.     

番茄红素菌体粉的安全毒理学评价

以三孢布拉氏霉为菌种,对其发酵制备的番茄红素菌体粉的经口急性毒性、遗传毒性及短期毒性等进行了研究。结果表明:番茄红素菌体粉经口最大耐受量(MTD)大于18g·kg-1,毒性分级为无毒级;Ames实验、小鼠骨髓细胞染色体畸变实验、小鼠精子畸形实验均表明番茄红素菌体粉无明显遗传毒性;30d短期喂养各组小鼠无异常症状,无死亡,其对小鼠的体重增长、血常规、血生化、脏器系数均无显著的影响。揭示了番茄红素菌体粉有较好的安全性,为番茄红素菌体粉直接应用成保健食品等提供理论依据。     

中国天然气勘探开发现状及物探技术需求

2000年以来,中国石油天然气集团公司在鄂尔多斯盆地、四川盆地、塔里木盆地、松辽盆地、柴达木盆地、渤海湾盆地等的天然气勘探中不断获得新的发现,初步形成了东部、中部、西部协调发展的合理布局。现阶段面临的问题是如何尽快将资源优势转化为经济优势。目前,我国天然气主要储集层为碎屑岩、碳酸盐岩和火山岩三大岩石类型。碎屑岩储层特征表现为我国中部丘陵地区的低孔、低渗的致密砂岩以及西部复杂高陡构造的孔隙砂岩;碳酸盐岩和火山岩储层普遍埋藏较深,非均质性强,缝洞单元难以刻画。因此,必须采用有针对性的地球物理勘探技术,优先发展碎屑岩气藏检测勘探技术,强化地震岩石物理等基础研究,加快碳酸盐岩、火山岩气藏检测技术攻关。同时开展高密度、多波地震勘探等前沿技术研究,为定量评价和产能建设提供技术保障。     

How can we best use landmarks to support older people in navigation?

Although landmarks are an integral part of navigation, they have rarely been used explicitly within electronic pedestrian navigation aids. We describe a two-part study into the use of landmarks in such aids, using a set of field experiments. The first part investigated whether such devices can be effective for older adults (over 60 years old), who might particularly benefit from them due to declines in sensory, cognitive and motor abilities. The second part compared the effectiveness of different methods of presenting landmark information. We show that a pedestrian navigation aid based around landmarks is particularly useful for older people and demonstrate that text, speech and photographs are all effective ways of presenting landmark information, although speech on its own has some drawbacks. We found that different people prefer information to be presented in different modalities, indicating a need for personalisation, although multi-modality may also help to address this issue.     

Rapid detection of a Schistosoma mansoni circulating antigen excreted in urine of infected individuals by using a monoclonal antibody

Schistosoma circulating antigens were used to indicate the infection intensity and to assess cure. An immunoglobulin G2a (IgG2a) mouse monoclonal antibody was used in a fast dot-enzyme-linked immunosorbent assay (ELISA; FDA) for rapid and simple diagnosis of schistosomiasis in the field. Seven hundred Egyptians were parasitologically examined for Schistosoma mansoni and other parasitic infections. A rectal biopsy was done as a "gold standard" for individuals showing no S. mansoni eggs in their feces. Egg counts were obtained by the Kato smear method for only 100 of 152 individuals with eggs in their feces. Specific anti-schistosome IgG antibodies were evaluated in sera by ELISA. Urine samples from the 700 individuals were tested by FDA for detection of the circulating antigen. The assay showed a sensitivity of 93% among 433 infected individuals and a specificity of 89% among 267 noninfected individuals. FDA showed the highest efficiency of antigen detection (91%) compared with the efficiency of antibody detection by ELISA (75%) and stool analysis (60%). In addition, FDA detected infected patients with 20 eggs/g of feces. Also, the sensitivity of FDA ranged from 90 to 94% among samples from patients with different clinical stages of schistosomiasis. All the assay steps can be completed within 30 min at room temperature for 96 urine samples. The monoclonal antibody identified a 74-kDa antigen in different antigenic extracts of S. mansoni and Schistosoma haematobium and in the urine of infected individuals. In addition, a 30-kDa degradation product was identified only in the urine samples. On the basis of these results, FDA should be used as a rapid tool for the sensitive and specific diagnosis of Schistosoma infection.