Thrombelastography in 26 healthy horses with and without activation by recombinant human tissue factor

Objectives – To develop a standardized technique for thrombelastography (TEG) analysis in healthy adult horses, with and without the ex vivo addition of tissue factor (TF) as an activator. To determine reference intervals for TEG parameters in the horse, and to determine if traditional coagulation tests correlate with TEG. Design – Prospective, observational. Setting – Veterinary teaching hospital. Animals – Twenty‐six healthy adult horses. Interventions – None. Measurements and Main Results – Thrombelastography with (TF‐TEG) and without (TEG) the addition of TF performed by 4 operators. Coagulation profiles (prothrombin time, activated partial thromboplastin time, platelet count, fibrinogen, antithrombin, and fibrinogen degradation products) were assessed in a subset of horses. Mean values (SD) for TEG parameters in healthy horses were: reaction time (R)=17.0 minutes (3.0 min), K time (K)=5.8 minutes (2.3 min), clotting rate (Ang)=42° (14°), maximum clot strength (maximum amplitude [MA])=60.3 mm (5.7 mm), CL30=97.0% (2.0%), LY30=0.8% (0.6%), CL60=92% (5.9%), LY60=3.2% (2.5%). Mean values (SD) for TF‐TEG parameters were: R‐TF=6.6 minutes (1.4 min), K‐TF=3.1 minutes (1.0 min), Ang‐TF=50.9° (9°), MA‐TF=62.3 mm (5.1 mm), CL30‐TF=97.8% (1.6%), LY30‐TF=0.6% (0.5%), CL60‐TF=90.8% (4.2%), and LY60‐TF=3.6% (1.9%). The addition of TF decreased R and K and increased Ang. TF‐TEG had a narrower SD for R, K, Ang, CL60 and LY60 compared with TEG. Interoperator differences were reduced by the addition of TF. Regression analysis indicated a positive relationship between MA and fibrinogen concentrations (P=0.02) and R‐TF time and prothrombin time (P=0.03). Conclusion – TF‐TEG using the described protocol may minimize variability in data obtained across institutions or users. However, due to the variability associated with different operators, it is recommended that each laboratory set up individual reference intervals with the personnel who will perform the assay, and that the assay protocols and data obtained are compared on a regular basis.     

Analysis on mechanical characteristic of coarse and fine particles layered structure of tailings

Indoor triaxial tests and direct shear tests are adopted to study the mechanical characteristic of coarse and fine particle layered structure of tailings, including two and three layer structures, and the influence of the change of lay thickness is taken into account. Triaxial tests results show that hierarchical structure’s cohesions, generally, are lower than those of fine and coarse particle tailings, and internal friction angles are between the fine and coarse particle tailings’. For the two layer structure, the specimen’s cohesion reduces and internal friction angle increases with the increase of coarse particle tailings’ layer thickness. For the three layer structure, when the coarse particle tailing is the interlayer, the specimen’s cohesion reduces with the increase of interlayer thickness; while when the fine tailing is the interlayer, the specimen’s internal friction angle decreases with the increase of interlayer thickness. Direct shear tests results show that hierarchical structure’s cohesions and internal friction angles are all lower than those of coarse and fine particle tailings.     

New, quick tests for herbicide resistance in black-grass (Alopecurus myosuroides Huds) based on increased glutathione S-transferase activity and abundance

Black-grass (Alopecurus myosuroides Huds) is a major grass weed in winter cereals in Europe. It reduces yields and can act as a secondary host for a range of diseases. Herbicide resistance in this species was first detected in the UK in the early 1980s, and has now been reported in thirty counties. To successfully manage herbicide resistance it is vital that suspect populations are tested so that appropriate action can be taken. Ideally, a test will be quick, cheap and easy to use. Furthermore, it should provide an unequivocal result before post-emergence herbicides are to be applied, allowing alternative strategies to be adopted where necessary. This paper reports the development of new tests for herbicide resistance based on our observation that the resistant black-grass biotype Peldon contains approximately double the activity of the enzyme glutathione S-transferase (GST) compared with susceptible biotypes. Data are presented on the production of a monoclonal antiserum to a novel 30 kDa GST polypeptide purified from the biotype Peldon. An ELISA using this antiserum is described and the utility of this assay to detect resistant black-grass biotypes in plants grown under glass and in the field is presented. In addition, a microtitre assay for GST activity is described, which allows the rapid assessment of GST activities of plants. Both abundance and activity of GSTs are discussed as markers for herbicide resistance in black-grass.     

从2012年EIMA展会看国外拖拉机技术发展及应对策略

通过对2012年意大利EIMA展会参展的拖拉机技术水平的描述,指出国内企业应采取的应对策略。     

宁夏四正青年荷斯坦牛后裔测定体系建设

由于宁夏在奶牛后裔测定体系建设方面仍然很薄弱,因此,宁夏四正生物工程技术研究中心作为宁夏唯一一家从事动物良种培育的科技型企业,有责任把奶牛后裔测定体系建设搞好,本文就宁夏四正青年荷斯坦牛后裔测定体系建设方面的做法进行了简单论述,供相关同行参考.     

Soil and Plant Testing Programs as a Tool for Optimizing Fertilizer Strategies

Summary

Soil and plant testing programs are still based on ‘trial and error’ methods and lack scientific underpinning in terms of relevant soil chemical and plant nutritional processes, and are site-specific. The programs are valuable when the objective is to diagnose and predict deficiencies of plant nutrients. The programs are less valuable for refined fertilizer strategies, like Integrated Nutrient Management, which are essential in the near future to satisfy changing agricultural, environmental, economic and legislative boundary conditions. A more scientific approach to soil and plant testing programs appears desirable. To reduce undesirable side-effects of fertilization on the environment, more emphasis should be placed on fertilizer type and on timing and method of application.     

测土配方施肥对北方寒区马铃薯产量的影响

为了探索适合北方寒区马铃薯(Solanum tuberosum L.)种植的测土配方施肥技术,对比了依据不同参数建立的施肥模式对马铃薯产量及经济效益的影响。依据3414试验获得的数据,采用土壤有效养分校正系数法、地力差减法及回归方程拟合求得的一元二次方程建立了3种施肥模式,对比试验表明,通过回归方程即氮(N):Y=25 400.7+166.5 N-0.35 N2(R2=0.958),磷(P):Y=35 669.7+181.7 P-2.2 P2(R2=0.948),钾(K)??Y=32 714.5+107.2 K-0.4 K2(R2=0.997),建立的最施肥模式获得的产量及经济效益分别较当地常规施肥处理高7.8%和2 138元/hm2,适合北方寒区马铃薯栽培。