Effect of different organic amendments on lettuce fusarium wilt and on selected soilborne microorganisms

This study evaluated the effect of different organic amendments on lettuce fusarium wilt caused by Fusarium oxysporum f. sp. lactucae in pots under controlled conditions. Their effects on the density of the pathogen, on the total fungi and on fluorescent Pseudomonas spp. were also evaluated after two subsequent lettuce crops. A significant reduction in the severity of the symptoms of F. oxysporum f. sp. lactucae was found after the use of Brassica carinata pellets (52–79% reduction) and compost (49–67% reduction), while Brassica green manure and cattle and chicken manure only provided partial control of fusarium wilt. However, variations in effectiveness were observed for the same treatment in repeated trials. In general, an increase was observed in Pseudomonas and a decrease in fungal populations in the growing medium, which was obtained by mixing a blonde sphagnum peat and a sandy loam soil with B. carinata pellets and compost after two consecutive cropping cycles. Prolonging the Brassica and compost treatments from 30 to 60 days did not significantly affect disease severity, plant growth or the microbial population of the total fungi or Pseudomonas. The largest lettuce biomass was obtained in the non‐inoculated growing medium amended with brassica flour, chicken manure, B. carinata pellets and compost, as a consequence of fertilization. The treatment with B. juncea green manure, B. carinata (pellets and flour) and compost applied 30 days before planting led to promising results and merits further investigation for use under field conditions.     

Recognition of Human G-protein Coupled Receptors Using Compressed Amino Acid Alphabets

G-protein coupled receptors（GPCRs） have a relatively conservative seven transmembrane helix（7tm） regions, and their N and C termini are various. In order to strengthen the features of GPCR families, N and C termini were removed in this study, then frequency features in the form of single amino acid and dipeptide compositions for recognition of human GPCRs were analyzed and extracted based on the compressed amino acid alphabets. Based on these features, classifiers were developed using support vector machine（SVM）. The ability of different compressed methods was investigated. The testing results demonstrated that the suitable choice of compressed method combined with amino acid composition information could get good performance for the recognition of human GPCRs.     

不同组合全饲粮颗粒饲料对肥育羔羊消化代谢的影响 Ⅰ.能量、ADF和氮的消化与代谢

按同质原则将20只无角陶塞特(♂)与藏羊(♀)的杂交一代(4～4.5月龄)分为4个试验组,每组5只(3只公羔,2只羯羔),每只为一个重复。采用3因子(2×2×2)设计,以研究同一营养水平和在精料为主类型饲粮中,改变部分能量饲料(A因子)和蛋白质饲料(B因子)对公羔和羯羔(C因子)消化代谢的影响。结果表明,A、B、C因子及其交互作用对能量表观消化率和氮表观存留率的影响不显著(P>0.05)。A因子及A、B因子交互作用对ADF表观消化率影响显著(P<0.01和P<0.05);B、C因子及其交互作用,A、B、C因子的交互作用对ADF的表观消化率无显著影响(P>0.05)。     

Study on splicing performance of different types of staple yarns

The present paper reports the detailed study on the splicing behavior of viscose staple fiber yarns made from ring, rotor, friction and air-jet spinning technologies. The linear density of all the yearns was kept constant at 29.5 tex. The splicing parameters like splicing pressure and duration of the splicing were taken as variables. Three levels of splicing pressure at constant splicing duration and three levels of splicing durations at constant splicing pressure were considered. Splices were introduced at all these levels for the four different technologies. These splices were tested for their tensile properties and the properties of splices were evaluated in terms of retained splice strength (RSS) and splice break ratio (SBR). The splice photographs were taken and splices were analyzed for their structure and for diameter profile along the length of the splice.     

不同营养水平全混合日粮（TMR）饲喂利杂牛育肥效果分析

[方法]研究采用全混合日粮（TMR）饲喂方式,对利木赞牛与本地黄牛杂交改良后代F1进行低、中、高3个不同营养水平（15～18月龄,分别编为试验Ⅰ组、Ⅱ组、Ⅲ组）的日粮配方筛选试验,基础日粮为全株玉米青贮+玉米芯+苜蓿干草+肉牛精料补充料,试验期100 d。[结果]研究结果表明,从平均期末体重、期内总增重及日增重指标来看,试验Ⅲ组（高营养水平）平均日增重达（1.63±0.33） ㎏,高于Ⅰ组（1.58±0.29） kg和Ⅱ组（1.61±0.30） kg,按平均期末体重、期内总增重和日增重排序,为试验Ⅲ组（高营养水平）>Ⅱ组（中营养水平）＞Ⅰ组（低营养水平）,试验结果的趋势表明,同品种组合杂种肉牛不同营养水平,其育肥增重效果不同。但组间差异不显著（P＞0.05）,可能与标本量不足有关。在经济效益方面,随着精补料/增重比重的增加,相应试验组肉牛的产出增加,但同时也增加了养殖成本,从试验组的头均纯收益、新增投入占产出比以及总投入占产出比3个方面进行从低到高的排序为Ⅲ组（高营养水平）＜Ⅱ组（中营养水平）＜Ⅰ组（低营养水平）。[结论]试验结果表明,此结果与其平均日增重和日料的营养水平是相吻合的。因此,为了节本增效,应充分利用宁夏地区的优势杂交肉牛组合,同时辅以标准化的、能够充分利用当地饲草优势的、多元化的、科学的日粮配方。     

Impact of Fusarium oxysporum on the holoparasitic weed Phelipanche ramosa: biocontrol efficacy under field-grown conditions

Under the changing agro-climatic conditions of western Europe, the parasitic weed Phelipanche ramosa infests host crops such as tomato, hemp, tobacco and oilseed rape at an increasing rate. A Fusarium oxysporum isolate (FOG), that had effectively reduced the parasite's incidence under controlled environmental conditions, was tested in different granular formulations (pesta granules, alginate pellets) on P. ramosa parasitising tobacco under field-grown conditions. FOG reduced number and biomass of P. ramosa shoots by between 50% and 70% in three consecutive years (2006–2008). A single pesta application did not show consistent results throughout seasons; 50% reduction of P. ramosa biomass (DM) in the first year could not be repeated in the following years (20–30%). An alginate formulation applied alone performed better. However, a combination of pesta granules with alginate pellets had the highest reliable control efficacy (60–70%) of all treatments in two seasons, compared with the untreated control. Fungal population counts in soil samples did not show a close correlation to biocontrol efficacy. To understand field performance of this biocontrol agent, additional glasshouse and laboratory studies were conducted using soil from the experimental site. The glasshouse study revealed some fungistatic effects of the field soil that partly explain the reduced efficacy (-40%) in the field compared with results obtained under controlled conditions. Results show the potential of FOG for P. ramosa control. Because formulation affected the biocontrol efficacy, it may be worthwhile to test how the delivery system can be changed in order to achieve increased disease development in the field.     

Potential use of abrasive air-propelled agricultural residues for weed control

A potential new post-emergence physical weed control tactic is described. It entails plant abrasion and death upon assault from abrasive grits propelled by compressed air. Grit derived from granulated walnut shells was delivered by a sand blaster at 517 kPa at distances of 300–600 mm from seedlings of Chenopodium album in glasshouse pots. Control was influenced by size of plants at time of treatment. Seedlings at the cotyledon to 2-leaf stages of growth were mostly destroyed by a single split-second blast of grit of <1 s duration, but were unaltered by compressed air alone. Plants at the 4- to 6-leaf growth stages required up to 10 blasts of grit to be killed. These results indicate that small weed seedlings of susceptible species might be physically controlled by abrasion from air-propelled grit derived from suitable agricultural residues.     

添加不同水平双乙酸钠对裹包TMR贮存效果的影响

【目的】研究裹包全混合日粮(Total mixed ration,TMR)中添加不同水平的双乙酸钠(SDA)对贮存效果的影响。【方法】在裹包TMR中分别添加鲜重质量分数0,0.1%,0.3%和0.5%的SDA,于贮存后第0,3,7,15和30天,对裹包TMR的感官、营养成分、发酵指标和有氧稳定性进行分析。【结果】0.3%和0.5%SDA添加组的裹包TMR可以良好贮存30 d。SDA添加水平越高,裹包TMR的有氧稳定性越好。添加SDA对裹包TMR的感官和营养成分影响差异较小。与其他2个处理相比,0.3%和0.5%SDA添加水平可以显著降低裹包TMR的pH值(P<0.05)和NH3-N/TN值(P<0.05)。【结论】从经济效益和添加效果考虑,在裹包TMR中添加0.3%SDA为适宜水平。     

轴心受压格构柱在考虑柱轴向变形时的缀条计算

轴心受压格构柱缀条的计算一般只考虑偶然偏心等造成的剪力,本文建议斜缀条的计算应考虑肢柱变形产生的压应力的影响,将使斜缀条的计算更合理。     

替米考星肠溶颗粒对猪的安全性试验

为了客观评价替米考星肠溶颗粒临床应用于猪的安全性,选取40头25日龄健康三元杂交猪,随机将其分成4组,每组10头,分别以1倍、3倍、5倍推荐剂量的替米考星肠溶颗粒拌料给药45 d,试验期内对受试猪进行血常规、血凝、血生化、尿常规、增重、料重比、脏器系数等指标的测定及病理学检查。结果显示,替米考星肠溶颗粒对受试猪的血液学指标、尿液指标、主要生产性能等方面未造成明显影响,说明替米考星肠溶颗粒以5倍推荐剂量(2000 g/1000 kg)临床应用于猪是安全的。