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1.
油蒿与沙蒿枝构件特征研究   总被引:5,自引:0,他引:5  
研究了生长在腾格里沙漠南缘油蒿与沙蒿两种固沙半灌木植物的枝构件特征。结果表明:油蒿与沙蒿大部分枝条分枝角度较大,为中等分枝角度类型(分枝角度50°~70°);油蒿与沙蒿枝条的伸展从3级枝到1级枝呈现减弱的趋势,即3级枝到1级枝的长度是逐渐变短的,且油蒿各级枝条长度均大于沙蒿的对应枝级的枝条长度;油蒿与沙蒿的枝径比和逐步分枝率均呈增加的趋势,油蒿的各级枝径比高于沙蒿,而逐步分枝率却比沙蒿的低。  相似文献   

2.
The 16S rRNA gene of 39 S. equi subsp. zooepidemicus strains and two S. equi subsp. equi strains was amplified by polymerase chain reaction and subsequently digested with the restriction enzyme Hinc II. A restriction profile with two fragments with sizes of 1250 bp and 200 bp could be observed for both S. equi subsp. equi strains and for 30 of the 39 S. equi subsp. zooepidemicus strains indicating a sequence variation within the V2 region of the 16S rRNA gene of the remaining nine S. equi subsp. zooepidemicus isolates. A segment of the 16S rRNA gene including the hypervariable V2 region of 11 S. equi subsp. zooepidemicus and two S. equi subsp. equi could be amplified by PCR and sequenced. The sequence of the V2 region of eight S. equi subsp. zooepidemicus strains appeared to be identical or almost identical to the sequence of the two S. equi subsp. equi strains. The sequence of the remaining three S equi subsp. zooepidemicus strains differed significantly from the sequence of S. equi subsp. equi. These differences allowed a division of S. equi subsp. zooepidemicus strains into two 16S rRNA types and might possibly have consequences for the taxonomic position of these phenotypically indistinguishable strains of one subspecies. A molecular typing could additionally be performed by amplification of the gene encoding the 16S-23S rRNA spacer region. A single amplicon of the spacer gene of 1100 bp could be observed for one S. equi subsp. zooepidemicus, an amplicon of 950 bp for two S. equi subsp. equi strains and 10 S. equi subsp. zooepidemicus strains, a amplicon of 780 bp for 27 S. equi subsp. zooepidemicus strains and a single amplicon of 600 bp for one S. equi subsp. zooepidemicus strain. The variations of the V2 region of the 16S rRNA gene and the size variations of the 16S-23S rRNA spacer gene were not related to each other. Both variations could be used for molecular typing of this species, possibly useful in epidemiological aspects.  相似文献   

3.
The best combination of primers and the annealing temperature of multiplex PCR for Campylobacter jejuni, Campylobacter coli, and Campylobacter lari were examined. The multiplex PCR was able to detect type strains of the three species. All results of identification of wild strains (30 strains of C. jejuni, 20 strains of C. coli, and 4 strains of C. lari) by the multiplex PCR coincided with those of the conventional biochemical identification tests, suggesting that the multiplex PCR can simultaneously differentiate C. jejuni, C. coli, and C. lari from wild strains of campylobacters easily and rapidly. Campylobacters were detected from sparrow feces by the multiplex PCR and antimicrobial sensitivities of the strains were determined to discuss the role of sparrows in contamination of broilers with C. jejuni. Three out of 13 strains of C. jejuni isolated from sparrow feces showed quinolone resistance. From the frequent use of quinolones for treatment of industrial animals like chickens, pigs, and cows, the three strains of quinolone-resistant C. jejuni in sparrows must have been originated from those industrial animals. Sparrows that have quinolone-resistant C. jejuni were considered to have contacted with industrial animals or thier feed. It may be presumed, on the contrary, that C. jejuni in sparrows could be a potential source of contamination of broilers.  相似文献   

4.
A nested PCR that successfully detected Neospora caninum DNA in serum of cattle was used for investigation of selected abortion cases and in a study of healthy pregnant cows at an abattoir. N. caninum DNA was not detected in serum from antibody positive dams that aborted due to N. caninum, but was present in serum of some antibody negative dams that aborted due to other causes. N. caninum DNA was also found in the serum of about half of the animals that aborted of undetermined cause, but was not detected in cow sera from two beef cattle herds in Western Australia with no recent history of abortion. In the abattoir study of 79 dams and their foetuses N. caninum DNA was found in serum of 3 dams and in material from 11 foetuses. The majority of the cows and all foetuses were antibody negative. Our findings suggest that there is no obvious relationship between the presence or absence of N. caninum DNA in serum and the presence of antibodies to N. caninum in dams, the presence of N. caninum DNA in foetuses or abortion due to N. caninum. This is the first report of the detection of N. caninum DNA in serum of cattle rather than the white blood cell fraction. It indicates the presence of free tachyzoites and/or parasite DNA in circulation. The results suggest that persistent infection in the absence of antibodies is a possible outcome of N. caninum infection. Infection of foetuses in the absence of antibodies supports the possibility of persistent infection due to immunotolerance to an early in utero infection. It is therefore important to test for N. caninum DNA as well as antibodies for the detection of exposed and/or infected animals. However, the presence or absence of N. caninum antibodies or DNA did not support nor exclude N. caninum as the cause of abortion. Additional criteria are required for a positive diagnosis of abortion caused by N. caninum.  相似文献   

5.
The pharmacokinetics and bioavailability of a formulation of chloramphenicol base in propylene glycol were determined following administration of single intravenous (i.v.) and subcutaneous (s.c.) 50 mg/kg doses of chloramphenicol to six non-lactating Holstein cows. Mean serum concentrations of chloramphenicol following i.v. administration of 50 mg/kg declined rapidly from a peak of greater than 100 micrograms/ml to 6.9 micrograms/ml at 12 h after administration. Serum concentrations were not detectable at 24 h after administration. The curve of serum concentrations vs time was characteristic of a two-compartment open model. Mean i.v. data gave a biological half-life of 4.3 h and a volume of distribution of the central compartment of 0.44 l/kg. Serum concentrations of chloramphenicol following s.c. administration of 50 mg/kg rose slowly to a broad peak near 20 micrograms/ml from 3 to 8 h after administration and then declined. These data were also analysed according to a two-compartment open model. The biological half-life was 4.2 h and the volume of distribution of the central compartment was 0.50 l/kg. Significant adverse reactions, including acute collapse, intravascular haemolysis and haemoglobinuria, were observed in cows when dosed i.v. Cows dosed s.c. exhibited local reactions at injection sites. The disadvantages of administration of 50 mg/kg doses of chloramphenicol base in propylene glycol appear to be significant and may outweight the potential advantages of parenteral use of the drug as presently formulated.  相似文献   

6.
Plasmid DNA of 68 strains of Salmonella that belonged to 18 serovars and exhibited 48 different plasmid profiles was examined for hybridization with a 32P-labelled DNA probe which consisted of a 3750 base pairs (bp) HindIII-HindIII fragment derived from the virulence region of the 60 megadalton (Mdal) plasmid of Salmonella typhimurium. The 32 Mdal plasmid of S. cholerae-suis, the 50 Mdal plasmid of S. dublin, the 36 Mdal plasmid of S. enteritidis, the 60 Mdal plasmid of S. gallinarum, the 60 Mdal plasmid of S. pullorum, and the 60 Mdal plasmid of S. typhimurium, plasmids that have been associated with virulence, all hybridized with the probe. Digestion of plasmid DNA of these strains with PvuII and hybridization with the probe revealed that the plasmids of strains of all six serovars contained fragments of approximately 2520 and 1520 bp that hybridized with the probe. Similarly, hybridization with BglI digests of DNA of the virulence-associated plasmids of strains of these six serovars showed that all six plasmids contained a fragment of approximately 3690 bp that hybridized with the probe. No other plasmids of these strains nor any plasmids of 12 other Salmonella serovars hybridized with the probe. Chromosomal DNA did not hybridize with the probe. The 60 Mdal plasmids of S. gallinarum and S. pullorum showed similar digestion patterns with restriction endonucleases BglI, BglII and PvuII.  相似文献   

7.
为明确球孢白僵菌(Beauveria bassiana)对桑天牛(Apriona germari Hope)的致病机制,探讨了球孢白僵菌侵染对桑天牛幼虫解毒酶系的影响,对用球孢白僵菌处理后不同时间桑天牛幼虫体内羧酸酯酶、谷胱甘肽-S-转移酶和乙酰胆碱酯酶活性进行了测定。结果表明球孢白僵菌对上述3种酶的活性有显著影响,其中对羧酸酯酶和谷胱甘肽-S-转移酶活性的影响,均表现出先刺激后抑制的作用;而对乙酰胆碱酯酶活性的影响则呈先抑制后激活再抑制再激活的趋势。  相似文献   

8.
用解剖镜和Sony数码相机对4种棘豆属(Oxytropis)植物的茎、叶、花和果实进行精细表观特征观察,以便掌握其识别要点和特殊结构术语,探讨其对生境的适应性。结果发现:4种棘豆植株被黑色、黄色或白色柔毛或绢毛不等。小叶形态为黑萼棘豆(O.melanocalyx)卵形,宽苞棘豆(O.latibracteata)近披针形,甘肃棘豆(O.kansuensis)长椭圆披针形,黄花棘豆(O.ochrocephala)长椭圆状卵形;萼齿形状为黑萼棘豆披针状线性,宽苞棘豆锥状三角形,甘肃棘豆窄披针形,黄花棘豆线状披针形。旗瓣和翼瓣先端分别为,黑萼棘豆2浅裂和微凹,宽苞棘豆近圆形和截形微凹,甘肃棘豆微缺和圆形,黄花棘豆微凹和圆形;龙骨瓣喙长为宽苞棘豆黄花棘豆黑萼和甘肃棘豆。黑萼棘豆雄蕊完全展开,基部有蜜腺,黄花棘豆蜜腺少;成熟花药淡黄色,大小为甘肃棘豆宽苞棘豆黄花棘豆黑萼棘豆。子房形状为黑萼棘豆披针形,宽苞棘豆椭圆形,甘肃棘豆和黄花棘豆具短柄。果实黑萼、甘肃和黄花棘豆为荚果1室,宽苞棘豆具狭隔膜为不完全两室。依据4种棘豆植物精细表观特征可将其区别,其形态特征均表现出对高寒环境的适应性。  相似文献   

9.
苜蓿根腐病病原菌的分离及鉴定   总被引:9,自引:1,他引:9  
从甘肃张掖、酒泉2市采集苜蓿Medicago sativa根腐病样品15份,按照柯赫证病律对其进行病原物分离、鉴定.结果表明:发病部位分离到的菌株以镰孢霉Fusarium spp.占优势,经致病性测定和接种试验证明,腐皮镰孢霉F.solani致病性最强,接种后病株率达60%以上;其次是尖孢镰孢霉F.oxysporum和串珠镰孢霉F.moniliforme,致病性弱,发病株率为16.7%~23.3%;腐皮镰孢霉与尖孢镰孢霉或串珠镰霉混合接种,发病率均高于单独接种的发病率,而病株上获得的其他分离物均无致病性.研究证明苜蓿根腐病是以腐皮镰孢霉为主要病原,并与尖孢镰孢霉和串珠镰孢霉复合侵染导致的一种病害.  相似文献   

10.
陈超  黄顶  王堃  张卫华  孙增慧  陈龙 《草地学报》2014,22(4):722-727
公路的建设给原有的生态系统带来人为干扰和影响,公路建筑材料的运输给外来植物的引入带来风险,公路修建以及环境因子则影响外来物种的建植和扩繁。选择北方农牧交错带典型的柏油公路,对草木犀属(Melilotus)外来植物沿公路的入侵状况进行样带调查,以探讨外来植物沿公路分布和扩散的影响因素。结果表明:公路两侧的土地利用方式是影响草木犀属植物分布的主要因素,路旁有农田的地段中,草木犀属植物的分布密度要显著大于有草地的地段(P<0.05)。距离则是影响草木犀属植物分布密度的重要因素,随着从路基到路旁生境距离的增加,草木犀属的分布密度呈显著下降趋势(P<0.05)。此外,公路的走向也影响草木犀属植物的分布,草木犀属在下风向的分布密度显著大于上风向的分布密度(P<0.05);公路两旁高大树木的遮阴同样影响草木犀属植物沿公路的分布,遮阴环境影响草木犀属一年生植物的密度(P<0.05),但对于二年生植株没有显著影响。  相似文献   

11.
OBJECTIVES: To evaluate the efficacy of subscapularis muscle tendon of insertion imbrication as a treatment for medial shoulder instability. METHODS: Medial shoulder instability was diagnosed in five dogs. Initial management with medical or arthroscopic treatment failed to fully resolve lameness in four of the cases. Each case was treated by subscapularis muscle tendon of insertion imbrication. An anatomical model of medial shoulder instability was used to assess the effect of subscapularis muscle tendon of insertion imbrication on the angle of abduction of the shoulder. RESULTS: In clinical study, subscapularis muscle tendon of insertion imbrication was performed in five cases. Lameness resolved fully in three cases and partially in two cases. In cadaver study, transection of either the subscapularis muscle tendon of insertion or the subscapularis muscle tendon of insertion and medial glenohumeral ligament significantly increased the angle of abduction. Imbrication of the subscapularis muscle tendon of insertion significantly reduced the angle of abduction. No significant differences were noted between the angle of abduction of normal shoulder and the shoulder with medial shoulder instability treated by subscapularis muscle tendon of insertion imbrication. CLINICAL SIGNIFICANCE: Subscapularis muscle tendon of insertion imbrication is a moderately effective procedure for the management of medial shoulder instability unresponsive to medical and/or arthroscopic management. The angle of abduction of the shoulder was returned to normal in model of medial shoulder instability, following subscapularis muscle tendon of insertion. Subscapularis muscle tendon of insertion imbrication provides a relatively simple method of treating medial shoulder instability in dogs.  相似文献   

12.
A new species of the genus Henneguya (Henneguya multiplasmodialis n. sp.) was found infecting the gills of three of 89 specimens (3.3%) of Pseudoplatystoma corruscans and two of 79 specimens (2.6%) of Pseudoplatystoma reticulatum from rivers in the Pantanal wetland, Brazil. Partial sequencing of the 18S rDNA gene of the spores obtained from one plasmodium from the gills of P. corruscans and other one from the gills of P. reticulatum, respectively, resulted in a total of 1560 and 1147 base pairs. As the spores of H. multiplasmodialis n. sp. resemble those of Henneguya corruscans, which is also a parasite of P. corruscans, sequencing of the 18S rDNA gene of the spores of H. corruscans found on P. corruscans caught in the Brazilian Pantanal wetland was also provided to avoid any taxonomic pendency between these two species, resulting in 1913 base pairs. The sequences of H. multiplasmodialis n. sp. parasite of P. corruscans and P. reticulatum and H. corruscans did not match any of the Myxozoa available in the GenBank. The similarity of H. multiplasmodialis n. sp. obtained from P. corruscans to that from P. reticulatum was of 99.7%. Phylogeny revealed a strong tendency among Henneguya species to form clades based on the order and/or family of the host fish. H. multiplasmodialis n. sp. clustered in a clade with Henneguya eirasi and H. corruscans, which are also parasites of siluriforms of the family Pimelodidae and, together with the clade composed of Henneguya spp. parasites of siluriforms of the family Ictaluridae, formed a monophyletic clade of parasites of siluriform hosts. The histological study revealed that the wall of the plasmodia of H. multiplasmodialis n. sp. were covered with a stratified epithelium rich in club cells and supported by a layer of connective tissue. The interior of the plasmodia had a network of septa that divided the plasmodia into numerous compartments. The septa were composed of connective tissue also covered on both sides with a stratified epithelium rich in club cells. Inflammatory infiltrate was found in the tissue surrounding the plasmodia as well as in the septa.  相似文献   

13.
对本地临床分离的20株致病性大肠杆菌进行耐药性检测和质粒检测。耐药性检测结果显示,受检20株致病性大肠杆菌对临床常用5种抗菌药物均表现为耐药,大肠杆菌耐药程度及多重耐药现象较为严重。质粒图谱分析结果表明,在大肠杆菌耐药性菌株中,尤其是耐药程度较高且呈多重耐药的菌株中,耐药质粒的检出率较高。实验结果提示:致病性大肠杆菌耐药性与其耐药质粒存在密切相关。  相似文献   

14.
The pharmacokinetics of a parenteral formulation of metoclopramide (monochloride monohydrate) were determined following single intravenous (i.v.) and intramuscular (i.m.) 0.5-mg/kg doses to two groups of 4 goats in a crossover design. Mean serum concentrations of metoclopramide following i.v. administration of 0.5 mg/kg declined rapidly from a peak of 277.5 ng/ml at 3 min post-dosing to 25 ng/ml at 90 min. Serum concentrations were not detectable by 120 min after drug administration. The curve of serum concentrations vs. time was characteristic of a two-compartment open model. Mean parameters from analysis of the individual i.v. data gave a biological half-life of 0.62 h and a volume of distribution of the central compartment of 1.34 l/kg. Serum concentrations of metoclopramide following i.m. administration of 0.5 mg/kg rose rapidly to a peak of 160.9 ng/ml at 15 min post-dosing and then declined in parallel with the elimination phase of the i.v. study. These data were best described by a two-compartment open model with first-order absorption. The mean biological half-life was 1.04 h. There were no adverse reactions associated with metoclopramide at the 0.5-mg/kg dose administered by either route.  相似文献   

15.
Effects of age of donor and other factors on superovulation and production of transferable embryos were investigated. Data were obtained on 987 recoveries of embryos performed between November 1980 and June 1984 by Select Embryos, Inc. The 339 Holstein donors ranged in age from 1.8 to 17.8 yr. The effects of age of donor and dose of follicle stimulating hormone (FSH) were examined using regression analysis. For on-farm recoveries, numbers of embryos, rates of fertilization, quality scores of all embryos and numbers of transferable embryos decreased (P less than .01, P less than .001, P less than .05, P less than .01, respectively) with increasing age of donor. For in-clinic recoveries, numbers of embryos plus ova recovered were affected by age of donor, dose of FSH and the interaction of the two (P less than .05). Among older donors, increasing doses of FSH were associated with an increase in the number of ova plus embryos recovered. However, among younger donors, increasing doses of FSH had a negative effect. Numbers of embryos, rates of fertilization and numbers of transferable embryos decreased (P less than .05) with advancing age and increased (P less than .05) with increasing doses of FSH. Greater numbers of ova plus embryos were recovered when treatment with FSH was begun on d 10 or 11 as compared with d 7, 8, 9, 12, 13 or 14 (P less than .001). It was concluded that an increase in age of donor had a negative influence on the success of superovulation and the production of transferable embryos, and that the response to FSH was affected by age of donor.  相似文献   

16.
1. To ascertain serious pains and sufferings in the meaning of section 17 no. 2 b law of prevention of cruelty to animals you cannot do without the help of an expert witness for taking possession of evidence--apart from simple cases. Except the clarifying of fundamental questions concerning prevention of cruelty to animals a professional statement of the administrative veterinary surgeon will be as a rule sufficient. 2. For the actual seizure of animals for the purpose of confiscation and compulsory disposal the criminal justice is extremely dependent on the support of the authorities of administration. Therefore a trouble-free cooperation of criminal justice, veterinary authorities, animal homes and--concerning the protection of species--authorities for protection of endangered nature is imperative. 3. The main problems with the application of the regulation concerning the interdiction of keeping animals according to sections 20 and 20 a law of prevention of cruelty to animals are justified in the legal prerequisites. It is unsatisfactory that an interdiction of keeping animals cannot be imposed by summary punishment order and that a confiscation of animals is not possible by criminal proceedings in case of offence against sections 20 subsection 3, 20 a subsection 3 law of prevention of cruelty to animals. Therefore an admission of the sections as mentioned above to section 19 law of prevention of cruelty to animals seems to be convenient.  相似文献   

17.
C·肉毒杀鼠素(下称毒素)0.1%浓度毒饵,对新疆的主要害鼠大沙鼠和黄兔尾鼠进行灭治,校正灭洞率分别为97.4%和90.2%,均可取得良好效果。常用农药0.5%甘氟毒饵的灭治效果分别为98.5%和67.1%。因此,毒素能够代替甘氟在新疆草地灭鼠中应用;以小麦和草颗粒作载体与0.1%毒素拌制毒饵,灭杀大沙鼠和黄兔尾鼠灭洞率分别为98.2%、99.3%和90.2%、91.7%,两种载体均可使用;新疆草地的害鼠四月份正值数量低峰期,废弃洞数量很大,有效洞率大沙鼠为9.37%、黄兔尾鼠为14.70%。  相似文献   

18.
The faeces of 205 domestic cattle (Bos taurus) from 5 regions of Saudi Arabia were examined for the presence of coccidian parasites. The following species of Eimeria were recovered: Eimeria auburnensis, E. bovis, E. cylindrica, E. ellipsoidalis, E. subspherica, E. wyomingensis and E. zuerni. A total of 34.1% of the individual faecal samples were positive for the presence of coccidial oocysts. Mixed infections of 2-4 species were found in 15.7% of the specimens. E. zuerni and E. bovis occurred most frequently and were generally the most predominant species. The incidence of coccidia-infected cattle was higher in the eastern region.  相似文献   

19.
Colonisation of type D Pasteurella multocida was studied in five groups of seven SPF piglets each. Piglets of Group 1 were kept together with seven 5-week-old piglets obtained from a large herd infected with toxigenic P. multocida for 16 weeks (contact infection). These piglets were made free from toxigenic Bordetella bronchiseptica by local immunisation. Piglets of Group 2 were inoculated with 5 x 10(7) colony-forming units (cfu) of P. multocida washed from the nasal mucosa of piglets free from toxigenic B. bronchiseptica with fetal calf serum. Piglets of Group 3 were inoculated intranasally with 5 x 10(7) cfu of P. multocida washed from yeast-extract proteose-peptone cystine (YPC)-blood agar with fetal calf serum. Piglets of Group 4 were inoculated with 5 x 10(7) cfu of P. multocida grown in a YPC-based broth without blood. Piglets of Group 5 served as controls. The piglets of Group 1 did not contract P. multocida infection from infected contact piglets. After a single inoculation one of four, while after three inoculations two of three piglets of Group 2 became infected by P. multocida. After a single inoculation none of four, while after three inoculations one of three piglets of Group 3 were colonised by P. multocida. Both single and repeated inoculation failed in piglets of Group 4.  相似文献   

20.
在低磷地区以分组对比的试验方法 ,用不同含磷量的牧草在同等条件下喂饲两组低磷奶牛 ,定期采样分析 ,对各组奶牛血钙、血磷、超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH- Px)、丙二醛 (MDA)及牧草、土壤中磷含量、喂饲后奶牛生产性能等进行测定和观察。结果表明 :(1)在预试验期 ,对牧草施撒磷肥 ,收获后 ,土壤和牧草二者含磷量均明显提高。在其后的几年间再次测定该两项指标仍处于较高水平 (P<0 .0 5 ) ,后效应明显。 (2 )对低磷奶牛喂饲富磷牧草后 ,其血清磷由1.0 2 mm ol/ L提高到 2 .0 5 m mol/ L,两组差异极显著。 (3)对照组与试验组随着喂饲时间的延长 ,血清中抗氧化指标变化明显 ,试验组抗氧化能力增强 ,SOD、GSH- Px活性增强 ;MDA含量降低。(4)从对奶牛生产性能的测定看出 ,试验组生产性能有较大幅度地提高。  相似文献   

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