Interactive effects of nitrogen fertilizer and altered precipitation on fungal communities in arid grasslands of northern China     

Wang  Hai  Ta  Na  Jin  Ke  Ji  Baoming  Schellenberg  Michael P.  Wei  Zhijun  Wang  Zhen 《Journal of Soils and Sediments》2020,20(3):1344-1356

Journal of Soils and Sediments - Fungi play an essential role in regulating the functioning of terrestrial ecosystems and are sensitive to climate change factors. Climate change incidents, such as...  相似文献   

RT13型指盘搂草机的设计与研究     

贾红超  塔娜  布库  焦巍 《农机化研究》2015,(12):102-105

针对天然草场产草量低、收集成本高及国外机具价格高这一现状,设计了RT13型指盘搂草机。在介绍搂草机整机结构及工作原理的基础上,对其指盘的运动及指盘平面距离等主要参数进行了设计计算。草场作业试验表明:该搂草机操作简单,形成的草条连续、外形整齐,可有效减少牧草收集时间,从而降低机具燃油消耗及人工成本。该机具各项技术性能指标符合设计要求,满足天然草场的收获要求。  相似文献   

犬瘟热病毒自然感染犬淋巴组织中T、B细胞变化的研究     

潘耀谦  赵德明  龙塔 《中国预防兽医学报》2007,29(5):363-367,400

为了调查患犬瘟热病犬淋巴组织中T、B细胞变化的特点及淋巴细胞减少的发病机制,试验通过免疫组织化学的方法观察了T细胞(用CD3和CD45RO检测T细胞)、B细胞(用IgG、IgM抗血清检测B细胞)和犬瘟热病毒(抗犬瘟热病毒抗体)在病犬淋巴组织中的分布。结果表明:在淋巴组织中的淋巴细胞、淋巴小结中树突状细胞和巨噬细胞中均检出了抗病毒阳性反应细胞。在骨髓组织的前髓细胞中也发现抗病毒阳性反应细胞和嗜酸性胞浆内及核内包涵体的存在。与对照组相比,CD3和CD45RO阳性细胞主要存在于T细胞的分布域;但CD3和CD45RO阳性T细胞的数量较少。位于淋巴组织中的巨噬细胞有的被CD45RO染成阳性。在B细胞分布的区域中,IgG、IgM阳性细胞的数量明显减少;一些位于淋巴组织的浆细胞也被IgG或IgM染成阳性。在淋巴组织中淋巴细胞减少的顺序为:IgG阳性细胞减少最明显,其次为IgM和CD45RO阳性细胞,再次为CD3阳性细胞。依据试验结果,作者认为病犬淋巴组织中淋巴细胞减少主要是由B细胞缺乏所引起的;淋巴细胞的增殖能力减弱是引起淋巴组织中淋巴细胞减少的重要原因。  相似文献   

Comparison of Cryoprotective Effects of Lycopene and Cysteamine in Different Cryoprotectants on Bull Semen and Fertility Results     

PB Tuncer  S Büyükleblebici  A Eken  U Taşdemir  E Durmaz  O Büyükleblebici  E Çoşkun 《Reproduction in domestic animals》2014,49(5):746-752

The objectives of this study were to compare glycerol and ethylene glycol at different concentrations as cryoprotectants and lycopene or cysteamine (with/without) as antioxidants in Tris extender for bull semen. Twenty‐four ejaculates were obtained from three bulls. Each ejaculate was split into four equal aliquots and diluted using both of the Tris extenders with glycerol (5% or 7%) or ethylene glycol (3% or 5%). After that, each extenders were split into three equal aliquots and added using both of the cysteamine 5 mm or lycopene 500 μg/ml, and control (without additives). The addition of 7% glycerol with cysteamine, 5% ethylene glycol with cysteamine and 3% ethylene glycol with cysteamine groups gave the lowest CASA motility than the other groups. However, 7% glycerol and 7% glycerol with lycopene resulted in a better rate of CASA progressive motility compared with that of other groups. Generally, all the lycopene groups signed better protective effects on acrosome and total morphology than the other groups. Glycerol 7% and 3% ethylene glycol with lycopene groups yielded to slight higher percentages of membrane integrity assessed by HOST than that of the other groups, but 7% glycerol with cysteamine and 3% ethylene glycol with cysteamine showed the worst percentages of membrane integrity. Glycerol 7% and 5% glycerol with lycopene gave rise to a higher value of VAP, VSL and VCL compared with that of the other groups. On the contrary, adding to 5% glycerol with cysteamine showed negative effect for VAP, VSL, VCL and ALH values. All cryoprotectant groups with lycopene decreased chromatin damage than the other groups. Ethylene glycol 3% led to lower non‐return rates of inseminated cows. However, this result was not considered to be statistically important.  相似文献   

我国鸡奇异变形杆菌病研究报告   总被引：1，自引：0，他引：1  

江益民  龙塔 《中国兽医学报》1996,16(1):67-70

１９８９年４月作者在我国河南洛阳发现鸡奇异变形杆菌病。本病由肠杆菌科变形杆菌属的奇异变形杆菌（Ｐｒｏｔｕｓｍｉｒａｂｉｌｉｓ）所引起，以肢腿瘫痪、排灰白色或黄绿色水样稀便为临床特征。４周龄内雏鸡最易感，发病率８１．４％，病死率５６．５１％；青年鸡和成年鸡感染，可引起化脓性骨髓炎，死淘率４％左右。用濒死鸡脑组织、骨髓分离菌２４ｈ肉汤培养物（０．１ｍＬ）感染的小鼠，可于２４ｈ左右死亡；经口感染４周龄雏鸡，可复制出与自然病例相同的临床症状、病理变化和６０％的病死率，并可从感染致死鸡的脑、骨髓中回收到本菌。该菌不产生外毒素，可产生毒力强大的内毒素。本病可用氟哌酸、吡哌酸、氧哌嗪、链霉素、庆大霉素治愈。  相似文献   

甘蓝型油菜DH系在不同生态区SPAD值的差异分析   总被引：2，自引：0，他引：2  

塔娜  王灏  关周博  李保军  赵亚军  王爱娜  田建华  穆建新  栗茂腾 《中国农学通报》2015,31(24):116-121

以甘蓝型油菜纯合双单倍体(DH)为材料,研究不同生态环境下油菜叶绿素SPAD值的变化状况,揭示叶绿素含量遗传表现规律,创制更高叶绿素含量种质资源,以期为油菜高光效育种奠定方法和理论基础。选取了170份甘蓝型油菜DH系,连续3年分别种植在冬油菜区(陕西大荔)和春油菜区(甘肃张掖)。结果表明:无论是不同遗传背景的DH系、还是同一亲本下的不同DH系材料,油菜DH系叶绿素含量在田间既表现出遗传稳定性,又容易受到外界环境影响,即在相似的生态条件下,同一区域即便不同年份的各DH系材料,叶绿素SPAD值的表现基本一致,但在不同生态区,油菜DH系的SPAD值差异很大。通过对油菜DH系亲本和DH系叶绿素SPAD值频数分布分析,叶绿素含量连续3年在2个生态环境具有广泛的连续分布,并且服从正态或者近似于正态分布,以及超亲分离的特点。这些都表明油菜叶绿素含量是一个典型的数量性状,受到多对基因的控制。  相似文献   

硫酸盐对小白鼠钼代谢的影响     

杨自军  龙塔  冉林武  王婷  温文彦  白东英  林霖  李玉法 《河南科技大学学报(农学版)》2004,24(4):31-33

实验选择健康小白鼠52只,体重(20±0.8)g,适应5d后,随机分为4组,每组13只,实验56d。定期剖杀检查,结果表明:I和II组小白鼠有轻度中毒表现,II组与III组RBC差异显者(P<0.05),HB呈下降趋势,组间比较差异均不显著(P>0.05),II组与III组WBC差异显著(P<0.05),I组ANAE+阳性率略高于IV组,II组ANAE+阳性率持续下降,6周后与I组差异显著(P<0.05),硫与钼存在剂量效应关系。  相似文献   

Venous blood gases, pH and bicarbonate values in oestrus-synchronised cows     

Taşal I  Ceylan E  Keleş I  Gülyüz F 《The Veterinary record》2005,156(2):50-52

  相似文献   

赤霉酸·6-BA 3.6%液剂高效液相色谱分析方法研究     

雷澍瑛  樊小龙  邢攀攀  冯塔  陈万松 《农药科学与管理》2012,33(10):42-44

本文采用高效液相色谱法,以甲醇＋甲酸水溶液为流动相,使用ODSC18、51μm为填料的不锈钢柱和二极管阵列检测器。在210nm波长下对赤霉酸·6-BA进行分离和定量分析。结果表明,该分析方法的线性相关系数赤霉酸为O．9999;6-BA为0．998;标准偏差赤霉酸为0．01;6-BA为0．02;变异系数赤霉酸为0．46％;6-BA为0．30％;赤霉酸平均回收率为97．7％;6-BA平均回收率为98．7％。  相似文献   

Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of S?o Paulo,Brazil     

Alessandra MMG de Castro  Taís F Cruz  Vanessa R Salgado  Tatiana M Kanashiro  Karen L Ferrari  Jo?o P Araujo  Jr  Paulo E Brand?o  Leonardo J Richtzenhain 《Acta veterinaria Scandinavica》2012,54(1):29

Background

Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms.

Findings

Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10).

Conclusions

The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.  相似文献