Pesticide residues in milk and fish samples collected from upper Egypt

In Egypt, buffalo milk is much preferred by consumers over cow's milk, while small catfish and bolti fish are common in the diet of farmers. Samples of buffalo milk, catfish, and bolti fish collected from Beni-Suef Governorate (Upper Egypt) were analyzed for organochlorines and polychlorinated biphenyls. The results obtained by gas chromatography and confirmed by thin-layer chromatographic techniques revealed high amounts of organochlorines in milk; residues were lower but occurred more frequently in fish samples. Pesticide contaminants found most often were HCH isomers including lindane, DDT complex, aldrin and dieldrin, heptachlor and heptachlor epoxide, hexachlorobenzene, and oxychlordane. Polychlorinated biphenyls were not detected in any of the analyzed samples.     

Targeting arthropod subolesin/akirin for the development of a universal vaccine for control of vector infestations and pathogen transmission

Diseases caused by arthropod-borne pathogens greatly impact on human and animal health. Recent research has provided evidence that tick protective antigens can be used for development of vaccines with the dual target of controlling arthropod infestations and reducing their vector capacity for pathogens. As reviewed herein, protective antigens such as subolesin/akirin, which are highly conserved across vector species, show promise for use in development of a universal vaccine for the control of arthropod infestations and the reduction of pathogen transmission. However, further research is needed in critical areas towards achieving this goal.     

The significance of enset culture and biodiversity for rural household food and livelihood security in southwestern Ethiopia

The significance of enset (Ensete ventricosum Welw. Cheesman) for thefood and livelihood security of ruralhouseholds in Southwestern Ethiopia, where thiscrop is the main staple, raises two majorquestions. The first concerns the relatedissues of household food security andlivelihood security and the contribution of theenset farming and food system in achievingthese. The second deals with the issue ofbiodiversity in enset cultivation. What roledoes biodiversity play in food and livelihoodsecurity and how is it perceived and measured?To answer the latter question, it is necessaryto look at the issue of classification of ensetvarieties, comparing indigenous and scientificclassifications. In answering the questions, aninterdisciplinary approach is used, and bothetic and emic perspectives are applied. Agender perspective is applied as well becauseof the gendered division of labor in ensetcultivation and the gendered nature ofindigenous knowledge. The analysis draws mainlyon the findings of a recent study on ensetcultivation in Ethiopia [Negash (2001) PhD thesis,Wageningen University, The Netherlands]. Thefindings show that enset farming guaranteeshousehold food security to a large extent, butthat household livelihood security depends onthe cultivation of additional crops andhousehold ownership of livestock and otherassets. It was also found that maximizingdiversity in enset is of importance to farmers,and that the farmers' classification of ensetvarieties yields a finer grid than theclassification of enset clones on the basis ofmolecular analysis.     

Metabolites of some biological control agents

The evidence is reviewed for the structure and biosynthesis of some metabolites of Trichoderma and Gliocladium species that are being considered as fungal biological control agents. The diverse biosynthetic capability of these organisms is proposed as a criterion for their potential application as bio-control agents.     

Genetic diversity of anaplasma species major surface proteins and implications for anaplasmosis serodiagnosis and vaccine development

The genus Anaplasma (Rickettsiales: Anaplasmataceae) includes several pathogens of veterinary and human medical importance. An understanding of the diversity of Anaplasma major surface proteins (MSPs), including those MSPs that modulate infection, development of persistent infections, and transmission of pathogens by ticks, is derived in part, by characterization and phylogenetic analyses of geographic strains. Information concerning the genetic diversity of Anaplasma spp. MSPs will likely influence the development of serodiagnostic assays and vaccine strategies for the control of anaplasmosis.     

Induction of aggregation in porcine lymphoid cells by antibodies to CD46

CD46 is a major transmembrane glycoprotein that belongs to the regulator of complement activation (RCA) family. Recently, mAbs to human CD46 were shown to suppress IL-12 production. Here, we describe that mAbs against different porcine CD46 epitopes induced a marked adhesion of normal lymphocytes. Addition of low amounts of antibody to freshly isolated lymphocytes or thymocytes resulted in the clustering of the cells. Cross-linking of CD46 molecules seems essential since Fab fragments failed to induce aggregation. This aggregation was dependent on active cell metabolism and on the presence of divalent cations and required a functional cytoskeleton. It was not inhibited by antibodies to CD18, CD29, CD2, CD11a and CD11b. Staurosporine, an inhibitor of protein kinases, partially blocked the aggregation. This finding is indicative of a role of protein kinases in the transduction of the signal generated by CD46 engagement.     

Genetic diversity of Anaplasma marginale strains from an outbreak of bovine anaplasmosis in an endemic area

Anaplasma marginale is a tick-borne pathogen of cattle that causes the disease bovine anaplasmosis worldwide. Major surface proteins (MSPs) are involved in host-pathogen and tick-pathogen interactions and have been used as markers for the genetic characterization of A. marginale strains. A. marginale genotypes are highly variable in endemic areas worldwide. The genetic composition of A. marginale strains during anaplasmosis outbreaks has been characterized in one study only which reported a single msp1alpha genotype in infected cattle. However, more information is required to characterize whether a single genotype is responsible for an anaplasmosis outbreak or whether multiple genotypes can cause disease in na?ve cattle within a single herd in endemic areas. The aim of this study was to characterize the genetic diversity of A. marginale strains from an outbreak of bovine anaplasmosis in the State of Tamaulipas, Mexico. A. marginale genotypes were characterized at the molecular level using msp4 and msp1alpha gene sequences. The results revealed that several A. marginale genotypes are present in cattle during acute anaplasmosis outbreaks, thus suggesting that mechanical transmission or stochastic biological transmission through equally efficient independent transmission events may explain A. marginale genotype frequency in a cattle herd during acute bovine anaplasmosis outbreaks in endemic areas. The results reported herein corroborated the genetic heterogeneity of A. marginale strains in endemic regions worldwide. The development and implementation of anaplasmosis control measures is dependent upon understanding the epidemiology of A. marginale in endemic regions, including the characterization of the genetic diversity of strains that produce outbreaks of bovine anaplasmosis.     

模拟增温和增雨对冷蒿营养元素分配的影响

通过野外控制温度和降雨条件模拟气候变化,设计4种试验处理,研究对照（CK）、增温（＋2℃,IR）、增雨（＋ 120mm,W）和增温＋增雨（IRW）处理对冷蒿（Artemisia frigida Willd.）不同部位（生殖枝与营养枝）营养元素吸收和分配的影响.结果表明：增温、增雨及其耦合作用对冷蒿不同部位营养元素的吸收和分配存在显著差异（P＜0.05）;与对照相比,增温效果不显著,而增雨显著影响冷蒿对N、K、Mg、Zn、Fe、Mn、Ni元素的吸收和分配（P＜0.05）;冷蒿不同部位对N、K、Mn吸收与分配比例存在显著差异（P＜0.05）,但是增温、增雨与不同部位之间无明显耦合作用.说明长期增温与增雨通过改变土壤水分、温度、养分状况和植物内在生长节律,直接或间接影响植物对营养元素的吸收和分配过程.