Red rice (Oryza sativa L.) and barnyardgrass (Echinochloa spp.) biotype susceptibility to postemergence-applied imazamox

Pot experiments were conducted to evaluate the level of imazamox tolerance in five red rice ( Oryza sativa L.) and four barnyardgrass (three Echinochloa crus-galli (L.) Beauv. and one Echinochloa oryzoides (Ard.) Fritch) morphologically distinct biotypes collected from rice fields in northern Greece. The susceptibility of barnyardgrass biotypes to propanil was also studied. Red rice biotypes were not controlled by imazamox applied at 40 g ha⁻¹. In contrast, 80 g imazamox ha⁻¹ provided 56–84% red rice control (averaged across shoot number and fresh weight reduction). Not all barnyardgrass biotypes were susceptible to imazamox applied postemergence. However, propanil applied at 2.6 kg ha ⁻¹ controlled the E. crus-galli biotypes well, but propanil applied at rates of 2.6 and 5.2 kg ha ⁻¹ was not effective in reducing the shoot number and fresh weight of the E. oryzoides biotype. Propanil applied at 10.4 kg ha ⁻¹ reduced the shoot number and fresh weight of this biotype by 78 and 85%, respectively. In most cases, a linear equation ( y  = % of control, x  = g ha⁻¹) provided the best fit for regressions between red rice or barnyardgrass shoot number or fresh weight and imazamox rates. The results of this study suggest that postemergence application of imazamox is not effective against all red rice and barnyardgrass biotypes found in the rice fields of Greece and that significant variability regarding herbicide efficacy among biotypes might exist.     

不同能量水平日粮对肉仔鸡生长及屠宰性能指标的影响研究

选择3周龄健康、无病、体重无显著差异的肉仔鸡96只,随机分为3组,每组设4 个重复,每个重复8只。分别饲喂蛋白质水平(19．5％)相同而能量水平不同(3．0 Mcal／kg、 3．08 Mcal／kg、3．16Mcal／kg)的3种饲粮。试验结果表明:前两周饲料转化(采食／增重)均以 中能量组(3．08 Mcal／kg)最好,为1．4416±0．1199,但三种不同能量水平对肉仔鸡平均日增 重、平均日耗料、饲料转化率均差异不显著(P>0．05);后两周饲料转化仍以中能量组最好,为 1．6362±0．1346,且显著优于高能量组(P<0．05),而与低能组和中能组之间差异不显著,各 能量处理组蛋白质、粗纤维、钙的代谢率均差异不显著(P>0．05),而磷的代谢率却存在显著 差异(P<0．05),其中,以中等能量组的磷代谢率最高,平均为90．73％;3种能量水平下肉仔鸡 半净膛率、全净膛率均差异不显著(P>0．05),表明能量水平并不影响肉仔鸡屠宰性能。     

破壁蜂花粉对蛋鸡免疫功能及肠道菌群的影响

试验将槐花蜂花粉进行振动磨超微粉碎破壁,分别按1 g/kg、5 g/kg、10 g/kg三个不同剂量混到蛋鸡饲料中,从7日龄开始饲喂至50日龄,每个剂量分两个试验,试验一用新城疫Ⅳ系疫苗免疫雏鸡,利用β-微量法监测血清中的血凝抑制抗体效价的动态变化;试验二用大肠杆菌油乳苗免疫雏鸡,利用间接血凝法监测血清中大肠杆菌抗体效价的动态变化。分别定期称重捕杀取脾、胸腺、法氏囊,计算免疫器官指数,取肠道内容物计数大肠杆菌和乳酸菌,测定肠道内pH值。结果表明,不同剂量的破壁蜂花粉均能不同程度地提高病毒抗原性抗体效价和菌体抗原性抗体效价,对雏鸡免疫器官的发育以及肠道内环境、菌群的平衡也有一定影响。     

西北干旱灾害及其气候趋势研究

利用西北五省1950～2000年降水、温度和农作物旱灾面积资料,用降水的Z指标法,农作物受旱成灾率确定了西北干旱指标和旱灾等级,分析了西北旱灾特征及气候变化趋势。表明西北农业旱灾以70、90年代最严重,而且呈增加趋势,气温在升高,降水在减少。根据预测21世纪前十年西北干旱有所减轻。     

Changes of urinary albumin and N-acetyl-beta-glucosaminidase in high altitude polycythemia at different altitudes and its mechanism

AIM:To study the changes of excretive amount of albumin(ALB), N-acetyl-beta-D-glucosaminidase(NAG) in patients with high altitude polycythemia(HAPC) at different altitude and its mechanism.METHODS:Urinary ALB, NAG, activity of red blood cell superoxide dismutase(RBC-SOD), malonyldialdehyde(MDA) and erythrocyte filtration index(EFI) of 231 healthy subjects and 86 patients with HAPC at different altitude were detected.RESULTS:Excretive amount of urinary ALB, NAG, and plasma MDA, EFI were higher, and RBC-SOD was lower in patients with HAPC than those in healthy subjects, the changes were significantly obvious, with increasing altitude. Urinary ALB and NAG were negatively correlates to EFI, and no correlated to the content of MDA and RBC-SOD.CONCLUSIONS:EFI exertes an independent influence on urinary ALB and NAG. The decrease in erythrocyte deformability caused by the increase of peroxidation of lipids might participate in the pathogenesis and progress of the increase of excretive amount of ALB and NAG in HAPC.     

Analysis of the association among three viruses infecting hop in Australia

Associations among Hop latent virus (HpLV), Hop mosaic virus (HpMV), and Apple mosaic virus (ApMV) were assessed in five hop cultivars at four commercial hop-growing regions in Victoria and Tasmania, Australia. The presence or absence of each virus was confirmed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Spatial patterns of virus-infected plants were characterized using the Spatial Analysis by Distance IndicEs ( sadie ) system of pattern analysis. The association among viruses (occurrence and covariation) was assessed using the Jaccard similarity index, Spearman's rank correlation coefficient, and sadie . The spatial pattern of plants infected by HpLV and HpMV ranged from random to highly aggregated depending upon the cultivar infected and the mean disease incidence. The spatial pattern of plants infected by ApMV was aggregated in six of the seven plots where ApMV was present. A strong positive association between HpLV and HpMV was found in all cultivars at all locations. This association may be the result of the viruses sharing a common aphid vector species, the presence of one virus enhancing the ability of the aphid vector to acquire the other virus either through transencapsidation or influences on virus titre, or mixed infections within source plants. Significant associations, positive or negative, were found less frequently between HpLV and ApMV, and HpMV and ApMV.     

纤维粗度对浆张性能的影响

利用纤维质量分析仪研究针、阔叶木浆打浆后的纤维形态，观察打浆后的纤维粗度及测定手抄片的性能。结果表明，打浆能改变纤维的粗度，从而影响手抄片的物理性能和不透明度。     

山羊传染性胸膜肺炎支原体和绵羊肺炎支原体对抗菌药物敏感性的研究

测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰乐菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y-98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰乐菌素对Y-goat和四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏作用.结果表明,这8种抗菌药物对Y-goat和Y-98的MIC(μg/mL)分别为:环丙沙星0.223、0.002 23,氧氟沙星0.281、0.014 0,单诺沙星0.136、0.014 0,红霉素0.021 8、无效,罗红霉素0.032 7、无效,泰乐菌素0.042 2、0.039 0,泰妙菌素0.021 7、0.052 0,四环素0.195、0.052 0.红霉素与氧氟沙星的联合药敏指数为1,是相加作用;红霉素与泰乐菌素对Y-goat的联合药敏指数为1.5,是无关作用;四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏试验指数均为0.375,是协同作用.     

甘肃省生态环境综合评价指标体系研究

甘肃省生态系统分为社会经济系统和自然生态系统两大类 ,社会经济系统指标体系由社会经济条件和人为环境压力构成 ;自然生态系统由水环境、森林生态系统、草地生态系统和土壤生态系统四个次一级系统组成 ,每个次一级生态系统由各自所属指标体系来系统评定。利用因子分析法、Delphi法和头脑风暴法经过多次综合专家意见最终确定 2 6项指标作为甘肃省生态环境质量综合评价体系。利用层次分析法 (AHP)定量各指标的权重。通过综合评价表明 ,甘南州、陇南地区、张掖地区的生态环境质量较好 ,甘肃中部广大黄土高原地区次之 ,河西走廊的武威市、金昌市和嘉峪关市环境质量最差。评价结果真实地反映了甘肃省生态环境的基本状况 ,说明该指标体系具有科学性 ,能够用于不同地区之间或同一地区不同时间的环境质量对比与变化研究。     

湖南猪致病性大肠杆菌的分离及药物敏感性监测

从湖南47个规模化猪场发生典型仔猪黄、白痢猪只的63份腹泻病猪分离出63株大肠杆菌，其中12株作致病力试验均有致病性，对25种抗菌药物药敏试验，大肠杆菌对胺卡那霉素和头孢唑啉敏感，敏感菌株分别占98．41％和92．06％；多种抗生素产生耐药性，且为多重耐药。