Fluorescence polarization assay for the detection of antibodies to Mycobacterium bovis in bovine sera

The performance of a fluorescence polarization assay (FPA) that detects antibodies to Mycobacterium bovis in bovine sera is described. The FPA reported here is a direct binding primary screening assay using a small polypeptide derived from the M. bovis MPB70 protein. A secondary inhibition assay confirms suspect or presumed positive samples. Specificity studies involved five different veterinary laboratories testing 4461 presumed negative bovine samples. FPA specificity was 99.9%. The FPA was used to identify herd status as either M. bovis infected or non-infected. Herd surveillance studies (nine herds) were performed in Mexico and South Africa. The FPA had a specificity of 100% (two negative herds), and correctly identified six of seven infected herds. Finally, sera from 105 slaughter animals that had gross lesions in lymph nodes similar to those seen with bovine tuberculosis were tested by the FPA. Thin sections from the associated formalin-fixed paraffin-embedded samples of lymph nodes were stained using hematoxylin and eosin (H&E) for morphologic examination and using the Ziehl-Neelsen (ZN) method for detection of acid-fast bacilli. Of the 105 animals, 78 were classified as TB suspect based on lesion morphology, 21 were positive by ZN, 9 were positive by FPA and 13 were positive by PCR for the tuberculosis group of Mycobacterium. Among the 21 ZN positives, 11 (52.4%) were PCR positive. Among the 9 FPA positives, 8 (88.9%) were PCR positive. For the 13 PCR positives, 8 (61.5%) were FPA positive and 11 (84.6%) were ZN positives. These results show that use of the FPA for detection of M. bovis infection of cattle has value for bovine disease surveillance programs.     

紫杏花芽形态分化特性研究

[目的]研究紫杏花芽形态分化调研,掌握紫杏与普通杏和樱桃李间的花芽形态分化特性及差异,为紫杏的开发利用提供理论参考.[方法]观察测量紫杏花芽大小及外部形态,采用常规石蜡切片法观察花芽内部形态分化特性.[结果]叶城紫杏的花芽为红褐色,呈椭圆锥形,长为3.06 mm,宽为1.65 mm,6月下旬进入分化初期,7中旬进入萼片分化期和花瓣分化期,8月上旬进入雄蕊和雌蕊分化期,7到9月是花芽分化盛期,10月中旬完成雌蕊分化,各分化时期有交错重叠的现象.[结论]叶城紫杏从花芽开始分化到雌蕊分化完成共需100 d,较晚熟佳娜丽长30 d,较黄果樱桃李长10 d,且叶城紫杏进入各分化阶段的时间及整体分化进程,均要晚于晚熟佳娜丽和黄果樱桃李.     

Effects of Convolvulus arvensis Water Extract on Germination of Okra Under Different Seed Sizes

Convolvulus arvensis is a toxic allelopathic weed that suppresses germination and growth of crops.The prime object of present study was to investigate effect of Convolvulus arvensis water extract on germination and performance of okra with different seed sizes.The seeds of okra variety pusa green were separated into three different sizes,viz large size(4.00-5.00 mm),medium size(3.00-3.50 mm)and small size(2.00-3.50 mm),and then soaked in allelopathic plant bindweed water extract and kept in patrisdishes for germination into the germinator at 15℃.The experiment was laid out using Complete Randomized Design(CRD)with three replications.The results showed that after sowing of 12 days the highest germination was observed in non-treated seeds as compared to seeds treated in Convolvulus arvensis water extract for 1 h,further non-treated large seeds produced maximum plants as compared to treated small seeds after sowing of 24 days.Meanwhile,root length,shoot length,root fresh and dry weight,shoot fresh and dry weight were recorded higher in non-treated large seeds as compared to small seeds soaked for 1 h in Convolvulus arvensis allelopthic water extract.It could be found that Convolvulus arvensis affected germination,seed growth and overall performance of okra,further presence Convolvulus arvensis in crops could cause negative impact on germination and integrity of okra crops.     

Comparing two methods of sequential fractionation in the study of copper compounds in Haplic chernozem under model experimental conditions

Purpose

It is very important to obtain the information on the soils capacity to immobilize HMs and distribute them among soil components. The aim of this work was to study the fractional composition of Cu compounds in Haplic chernozem under model contamination conditions using different fractionation methods.

Materials and methods

The fractional composition of copper compounds in Haplic Chernozem artificially contaminated with copper acetate has been studied under model experimental conditions. General regularities and differences in the distribution of Cu forms in soils at the use of sequential fractionation by the Miller method modified by Berti and Jacobs (1996) and the Tessier method (Tessier et al. 1979) are revealed.

Results and discussion

The differences are related to the metal affinity for specific carrier phases, as well as to the selectivity and extraction capacity of the reagents used in these methods. A significant increase in the most mobile exchangeable Cu fraction is observed in contaminated soils. Aluminosilicates and soil organic matter make the largest contribution to the adsorption and retention of Cu.

Conclusions

The Tessier method is more suitable for the separation of the total technogenic component from contaminated soils. The Miller method is more informative at the determination of loosely bound HM compounds because of the use of weaker extractants.

     

Influence of PAH contamination on soil ecological status

Purpose

The purpose of this paper is to study the responses of soil biological parameters as indicator of ecological status on PAH-contaminated soil.

Materials and methods

Studies are conducted on the soils and natural grassy vegetation of monitoring plots subjected to Novocherkassk power station (NPS) emissions. Monitoring plots were established at different distances from the NPS (1.0–20.0 km).

Results and discussion

The level of polycyclic aromatic hydrocarbons (PAHs) around NPS is the highest at the monitoring plot located at distance 1.6 km to the northwest through the prevailing wind direction. Gradually, decrease of PAHs was observed while increasing the distance from the NPS through the prevailing wind direction. Calculation of correlations between PAH level and biological activity parameters of soils showed lack of dependence with total and every PAH content in all 12 studied monitoring plots. The most significant correlations were found between PAH content and enzyme activity in the monitoring plots situated through the prevailing wind direction from NPS.

Conclusions

The main pollution source in the studied area is NPS. It was found that contamination of soil by PAHs has a direct dependence on the activity of all biological communities in chernozems, as well as the activities of dehydrogenase and the phytotoxicity of soils. Inverse correlations have been revealed between the PAH contamination and abundance of soil bacteria.

     

Early life history of yellow puffer,Chonerhinos naritus (Richardson, 1848) from Sarawak,Northwestern Borneo

The growth and morphological development including fins, spine distribution and pigmentation of larval and juvenile of hatchery‐reared yellow puffer, Chonerhinos naritus were described to provide essential information on the early life history of this species. The total length (TL) of newly hatched larvae was 3.42 ± 0.23 (mean ± SD) mm, reaching 5.66 ± 0.38 mm on 5 days after hatched (DAH), 7.80 ± 0.28 mm on 11 DAH, 9.88 ± 0.40 mm on 27 DAH and 10.92 ± 0.58 mm on 30 DAH. The yolk was completely absorbed in preflexion larvae at 4 DAH. The mouth opening started at 3 DAH of yolk sac larvae, while the teeth appeared starting from preflexion larvae at 7 DAH. Overall aggregate fin ray numbers including caudal fin attained full complement in postflexion larvae at 27 DAH. Several melanophores with appearance of small stellate were first appeared dorsally on the head of flexion larvae at 13 DAH, expanded at the dorsal region of the head, above the eye in juveniles at 30 DAH. The spines first appeared in preflexion larvae of C. naritus at 7 DAH, covering the ventral skin region below pectoral fin base and expanded to the ventral part of the body and nearly covered the whole abdomen region before the anus and below the eyes in juveniles. C. naritus remain as larvae for approximately 29 days, during which they metamorphose to the juvenile stage prior to sexual maturation. Observations in larvae development of C. naritus revealed similar characteristics with other Tetraodontidae species.     

Callus induction and in vitro plant regeneration of rice (Oryza sativa L.) under various conditions

The objective of the present study was to develop an effective protocol for optimum callus induction and complete plant regeneration for four varieties of rice (Oryza sativa L.) i.e., Super Basmati, Basmati-370, Basmati-371 and Fakhre Malakand. Calli were induced from mature seed scutelum. The Murashige and Skoog (MS) and Chu's N6 media containing hormone 2, 4-D (2, 4-Dichlorophenoxy acetic acid) in different concentrations were used for callus induction. Fakhre Malakand produced maximum calli on N6 media containing 3 mg L(-1) 2,4-D. while other three varieties showed maximum callus induction on N6 media containing 2.5 mg L(-1) 2,4-D. N6 media was found better than MS media for callus induction. For complete plant regeneration the calli of two varieties i.e., Basmati-370 and Basmati-371 were plated on N6 media containing different concentrations of NAA (1-Naphthalene acetic acid) and BAP (6-benzyl aminopurine). The maximum regeneration frequency (%) was observed on N6 media containing NAA 1 mg L(-1) and BAP 2.5 mg L(-1). It took 27-30 days for the callus to regenerate into a complete plant. Basmati-370 produced 4-7 plantlets per callus whereas Basmati-371 produced 4-8 plantlets per callus with regeneration frequencies of 61 and 69%, respectively.     

10个新疆梨品种开花生物学及果实品质特征研究

了解新疆梨品种的开花生物学及果实品质特征,为其合理利用提供数据参考。在10个新疆梨品种的生殖生长期,对开花物候期、花部特性、花粉特性及果实品质特性等进行测定对比分析。结果表明:除‘艾温切克’‘库尔勒黄酸梨’外,其他8个品种花期一致,但果实成熟期有明显差异;‘库尔勒香梨’与其他品种的花器官特征无明显差异;‘绿梨’‘阿克苏句句梨’的花粉活力较强、单花药花粉量较多;‘艾温切克’‘绿梨’等4个品种的单果重较大,显著大于‘库尔勒香梨’;‘艾温切克’的果实硬度最小,与‘库尔勒香梨’无显著差异;‘艾温切克’‘绿梨’的可溶性糖、可溶性固形物、维生素C含量均较高,与‘库尔勒香梨’无显著差异或显著高于‘库尔勒香梨’。综上,‘绿梨’‘阿克苏句句梨’的花期与‘库尔勒香梨’重叠,花粉量较多、萌发率最高,花器官特征与‘库尔勒香梨’接近,可作‘库尔勒香梨’的备选授粉树;‘艾温切克’‘绿梨’的果实品质及口感好、果实成熟期早,且果皮颜色与其他品种有明显差异,可作为优良育种材料。