Radiation Balance Components of Maize Hybrids Grown at Various Plant Densities

Components of the energy and heat balances were examined in two maize hybrids grown at three different plant densities (40, 70 and 100 thousand plants per hectare). One of the hybrids was drought tolerant, while the other was bred for cultivation under irrigated conditions. An increase in plant density influenced not only the size of the leaf area, but also the distribution of the leaves at various plant heights. The extinction coefficient, which provides a quantification of radiation penetration, was higher in the irrigated treatments. By contrast to the other two treatments, the plant canopy in the thinly sown stands remained open throughout the vegetation period, and thus behaved quite differently to the closed stands, making it impossible to compare them. Smaller albedo values were recorded for the hybrid bred for irrigation and in thinly sown stands. The low plant density allowed more energy to reach the soil, from which it was reflected, making a considerable contribution to the final temperature in the stand. The latent heat, in keeping with the quantity of water transpired, was the greatest in the densely sown stands. There was little difference between the latent heat values of the normal and dense stands in either hybrid, indicating that they both had a similar sensitivity to increased stand density. If sufficient water is available it would appear that the stand density could be increased even for the drought-tolerant hybrid.     

Proteomics: A new tool in bovine claw disease research

Claw horn disruption (CHD) is a common underlying cause of lameness in dairy cattle which leads to compromised animal welfare and production losses. Despite an intense research effort over the last two decades, progress in reducing the prevalence of lameness due to CHD has been limited. In addition to current research strategies there is a need to develop novel approaches and methods that expand understanding of the disease mechanisms involved in CHD. The objectives of the present study were to explore the potential of liquid chromatography tandem mass spectrometry (LC-MS/MS) in mapping protein expression in three different bovine claw tissues, and to provide a relevant functional annotation of the proteins characterized in these tissues. LC-MS/MS was used to characterize protein expression in coronary band skin (C), claw dermal (D) and lamellar (L) tissues from two heifers. A total of 388 different proteins were identified, with 146 proteins available for identification in C, 279 proteins in D and 269 proteins in L. A functional annotation of the identified proteins was obtained using the on-line Blast2GO tool. Three hundred and sixteen of the identified proteins could be subsequently grouped manually to one or more of five major functional groups related to metabolism, cell structure, immunity, apoptosis and angiogenesis. These were chosen to represent basic cell functions and biological processes potentially involved in the pathogenesis of CHD. The LC-MS/MS-based proteomic analysis presented here is the largest published survey, so far, of the bovine claw tissue proteome.     

PVC单、双壁波纹塑料管用作农田排水暗管比较研究

通过室内材料力学试验和水力学试验，对PVC单、双壁波纹塑料管有关性质进行了比较研究，试验结果表明：PVC双壁波纹塑料管的力学性质和水力学性质均较单壁波纹塑料管优越，适于作农田地下排水暗管。     

Spontaneous antibiotic resistance mutation associated pleiotropic changes in Escherichia coli O157:H7

Besides the well-known O157:H7 clone causing enterohaemorrhagic colitis and haemolytic uraemic syndrome in Europe, Japan and North America, the number of Escherichia coli isolates with non-motile (NM) phenotype has considerably increased. We supposed that spontaneous antibiotic resistance mutation could cause this phenotypic change. To model our hypothesis we isolated rifampicin--(Rif) and ampicillin--(Amp) resistant mutants from E. coli O157:H7 prototype strains 7785 and EDL933. Among Rifr mutants we could isolate strains with no or reduced motility, while the Ampr mutants became hypermotile. The biochemical profile of the mutants had not changed but phage sensitivity and generation time of the mutants were altered. Among the representative strains we did not find polymorphism with Southern blot analysis and no polymorphism was found in the fliC gene of the mutants. The described characteristics have proven to be stable. In a mice virulence assay by intravenous infections the virulence of the derivatives was also found to be changed. In summary, we found that the antibiotic-resistant phenotype in E. coli O157:H7 was coexpressed with several other phenotypic changes including motility and virulence. It can be assumed that expression of the involved phenotypes may be under the influence of a common regulatory cascade. Further work is needed to identify the components and mechanism of this regulatory system.     

Comparison of echocardiography and gated equilibrium radionuclide ventriculography in the measurements of left ventricular systolic function parameters in healthy dogs

Left ventricular systolic function was assessed in 12 healthy dogs with equilibrium radionuclide ventriculography. The results of the analysis were compared to traditional echocardiographic measurements. Left ventricular internal dimensions and volume were measured at the time of end-systole and end-diastole. Ejection fraction--one of the most informative parameters of cardiac function--was calculated in each animal. Values (e.g. EDD, ESD, EDV, ESV) measured by the scintigraphic method were significantly (Student's t-test, p < 0.05) higher than the data obtained by echocardiography. Ejection fraction (EF) was the only parameter that did not differ significantly when comparing the two imaging techniques. The difference between the results of parallel measurements was in inverse ratio to the size of the heart.     

The role of female veterinarians in Africa

While the number of female veterinary students has reached figures as over 80% in the Netherlands and other European countries, the number of female veterinary students in Africa is also changing but still at a slower pace. Still nowadays, according to UNICEF, two-thirds of primary school age children, denied their right to basic education, are girls. In addition, especially in rural areas in Africa, there are only few secondary schools, so that children, either have to travel over large distances on a daily basis or have to live away from their families. As girls, already from an early age play an important role in the daily household routine, they are often not allowed to leave for schooling. There used to be less than 10 veterinary faculties in Africa during the first half of the 20th century. These faculties were located in South Africa, Sudan, Egypt and Nigeria. For many years, African veterinarians were also trained in western countries (UK, France, USA) or in former communist countries (Russia, Ukraine, Romania, Hungary Eastern Germany, Cuba) depending on the existence of historic or political links. A long stay abroad made it more difficult for female students, especially for those with children. Still nowadays, female veterinarians in Africa are mostly working for the veterinary departments mainly in the urban areas. Another area where many female veterinarians can be found are governmental diagnostic and research laboratories as well as training institutions such as veterinary faculties or agricultural colleges. Generally the salaries at these institutions are very low and therefore their male colleagues have gradually shifted to work in the private sector with more competitive salaries (private clinics, sector pharmaceutical companies, development projects, (agricultural) banks, etc). As still in most societies, women tend to follow their husbands, most female veterinarians are bound to find employment where their husbands are based. In addition, as most postgraduate training required a prolonged stay abroad, women encountered difficulties in leaving their families behind to improve their career perspectives. Gradually, there has been an increase of possibilities of post-graduate training in the African region as well as the introduction of a modular system and perspectives for training over the internet. These developments will clearly be beneficial for women, as it will enable them to follow post-graduate training without leaving their families for extended periods. Gradually, also female veterinarians in Africa are becoming empowered and recognise their capabilities. The understanding of the importance of gender aspects especially with regard to animal husbandry practices has opened up new opportunities for female veterinarians to work in extension services and as health promoters. The access to further education is the key to expanding their professional perspectives.     

International and collaborative strategies to enhance genetic health in purebred dogs

Health problems in pedigree dogs have recently been highlighted in the media worldwide and verified internationally by cynological organisations. Collaborative actions are now needed to deal with both existing and future issues. In this article, potential roles for various stakeholders are discussed and the value of national and international platforms for collaborations is stressed. Development of specific strategies for action must be based on criteria of significance, such as severity, prevalence and inheritance, as well as availability of effective preventive measures. Assessment of options should be founded on evidence from appropriate populations-at-risk and consider broader issues, such as demographics and human-animal interactions. Existing data, such as those from insurance statistics and health surveys, should be used as a reference until representative national/international population-level breed-specific data are available. Key issues and challenges, as well as possible strategies to address them, are discussed.     

利用RT-PCR检测库尔勒香梨苹果茎痘病毒的研究

 以库尔勒香梨新鲜、冷藏、冷冻叶片和皮层为材料,对提取双链RNA (dsRNA)的2种方法和提取总RNA的3种方法进行了分析比较,并对总RNA的提取方法进行了改进,获得了纯度较高、完整性较好的dsRNA和总RNA,在此基础上进行了反转录(RT)和PCR扩增。在国内首次完成了对苹果茎痘病毒(ASPV)的RT-PCR检测,建立了ASPV有效RT-PCR反应体系。用此体系扩增到ASPV一个长约316 bp的片段。实验表明以dsRNA和总RNA为模板均能成功进行RT-PCR检测,且dsRNA优于总RNA。     

Behavioral and physiological evaluation of sows raised in outdoors systems in the Brazilian semiarid region

Tropical Animal Health and Production - The objective of this study was to evaluate the biochemical, behavioral, and physiological parameters in pregnant sows of native and improved crossbreeds...