城市污泥中重金属的形态分布和处理方法的研究

采用室内实验方法，研究了城市污泥中重金属的形态分布特征和转化机理，并对重金属的加硫酸根稳定和酸浸出两种处理方法进行了探讨。结果表明，污泥中约73％的Zn和70％的Ni以不稳定态存在，约72％的铜以硫化物及有机结合态形式存在，其他重金属主要以稳定态存在；厌氧消化工艺对可交换的离子态重金属的转化有明显的促进作用。通过向污泥中投加SO4^2-可以在一定程度上提高Zn的稳定性。酸浸出试验中：在pH＝2时，污泥中Zn的浸出率达到30％以上，Ni的浸出率达到40％以上，Cu基本不被浸出。     

Molecular and serological detection of animal and human vector-borne pathogens in the blood of dogs from Côte d’Ivoire

In Côte d’Ivoire, limited information are available on vector-borne pathogens, their prevalence and distribution. Here, we assess the occurrence and diversity of canine vector-borne diseases (CVBDs) in Abidjan and Yamoussoukro cities. Blood from a total of 123 dogs were tested for Leishmania infantum and Ehrlichia canis antibodies and screened for Leishmania and Trypanosoma spp., Piroplasmida, Filariidae and Anaplasmataceae by PCR and sequencing. Among dogs, 39 % were positive for at least one pathogen. Seroprevalences were: 15.4 % and 12.2 % for L. infantum and E. canis, respectively. DNA of L. infantum and T. congolense (4.1 %), Baabesia vogeli (1.6 %), Filariidae (Dirofilaria immitis, D. repens and Acanthocheilonema reconditum) (10.6 %) has been detected. Anaplasmataceae were detected in (17.1 %) and E. canis was the only identified specie. Co-infections were observed in 13.8 % of dogs: E. canis-L. infantum co-infection was the most prevalent (4.9 %). Age, breed and sex of dogs do not seem to influence infections. Village dogs were more susceptible to CVBDs than kennel dogs (PV = 0.0000008). This study reports for the first time the presence of L. infantum, B. vogeli, A. reconditum, D. immitis and D. repens in dogs from Côte d’Ivoire and determines the prevalence and diversity of CVBD pathogens. The results indicate that human and animal pathogens are abundant in Ivoirian dogs which requires attention of veterinarians, physicians and authorities against these diseases, especially against major zoonosis such as visceral leishmaniasis (L. infantum).     

利用γ射线辐照诱发水稻龙特甫B叶色突变

用60Co-γ射线直接辐照龙特甫B干种子,诱发获得了多种类型叶色突变体。M2 代按苗计,白化、黄化和条纹三种叶色突变体的频率依次为0.347% ,0.041% 和0.031% 。对M2 代黄化和条纹两类突变群体的生长发育动态研究发现,其平均叶片数和分蘖数与对照有较大的差异。但有一些黄化和条纹突变体在三叶期后即可转为绿色,其叶片数和分蘖数与对照相近。在用这些叶色突变体与龙特甫A 杂交、回交后的M 4BC1 群体中,分离出正常绿色和带有叶色标记的两类不育株,二者之比接近1∶1。根据苗期和成株期的叶色特征,这些突变系分为 6 种类型。对M 4 突变系的株高、单株穗数、每穗总粒数、每穗实粒数和结实率及相应的 M4BC1 植株的株高和单株穗数进行了考察,发现转绿型突变系及其相应的M4BC1 带叶色标记植株的农艺性状与相应的对照相仿。     

Origin of Clostridium perfringens isolates determines the ability to induce necrotic enteritis in broilers

Since the ban on growth-promoting antibiotics in animal feed in the European Union, necrotic enteritis has become a major cause of mortality in broiler chickens. Despite the importance of the disease, the pathogenesis is still not completely understood. In the current study, Clostridium perfringens strains isolated from healthy flocks and isolates from outbreaks of necrotic enteritis were evaluated for the ability to cause gut necrosis in an intestinal loop model in laying hens and in an experimental infection model in broilers. High, intermediate and low alpha toxin producing strains were chosen from each isolation source. Only the isolates from field outbreaks induced necrotic gut lesions, independent of the amount of alpha toxin produced in vitro. It was also shown that alpha toxin producing isolates from calf hemorrhagic enteritis cases were not able to induce necrotic enteritis in poultry. These results suggest the presence of host specific virulence factors in C. perfringens strains, isolated from chickens with intestinal necrotic enteritis lesions.     

溶液介质条件对Fe~(3+)共沉淀去除Cu~(2+)的影响

采用室内试验方法，研究了溶液介质条件对Fe^3 共沉淀去除Cu^2 的影响。试验结果表明，pH是影响Fe^3 共沉淀去除Cu^2 的主要因素之一，其去除率随pH的增加而增加，并且其固液分配系数Kd的对数值与pH之间显示出较好的线性关系；天然水体中溶解的电解质离子及无机和有机配位体对Cu^2 的去除均产生很大影响，Cu^2 的去除率随加入的NaCl和NaClO4浓度的增加而降低，而随Ca(NO3)2和Mg(NO3)2浓度的增加而增加，除磷酸盐的增强作用外，硫酸钠、碳酸氢钠、甘氨酸、草酸钠、柠檬酸钠以及十二烷基苯磺酸钠的加入则不同程度地减弱了Cu^2 的去除；与Cu^2 共存的等量竞争阳离子Pb^2 、Zn^2 和Cd^2 也同样减弱了Fe^3 对Cu^2 的去除。     

Geographical patterns of phenotypic diversity in <Emphasis Type="Italic">Oryza sativa</Emphasis> landraces of Côte d’Ivoire

The knowledge of agro-morphological diversity and the distribution pattern of variation among conserved accessions could be an invaluable aid in germplasm management and crop improvement strategies. In this study, the geographical pattern of morphological variation of 880 landrace rice (Oryza sativa (L.)) accessions in Côte d’Ivoire was evaluated for 13 agro-morphological characters. Shannon –weaver diversity index indicated an overall mean of 0.47 ± 0.07 in the collection, with the greatest diversity from derived Savanna and north-west (H′ = 0.52 and 0.50) while the west-central had the lowest diversity (H′ = 0.41). Canonical discriminant analysis showed that traits such as panicle length, grain size (weight and length), tillering ability, number of days to heading and maturity were the main discriminatory characteristics. Result of the phenotypic frequency shows that, the landraces from the north and north-western zones were mostly tall, early heading and maturity, compared to those from the west and west-central which were mainly dwarf to medium height, late heading and maturing. This differential distribution of landraces with height, heading and maturity period reflected the distribution pattern of different Oryza sativa landraces in Côte d’Ivoire, which could be useful in germplasm management and breeding programs.     

An explicit stem profile model for forked and un-forked teak (Tectona grandis) trees in West Africa

Studies on stem profile of teak (Tectona grandis) hardly exist. This can be possibly attributed to the occurrence of forks that is prevalent on teak trees. Stem profile model was therefore developed for teak in West Africa, which took into account the occurrence of forks. Trees were destructively sampled from Moist Evergreen Forest (MEF), Moist Semi-deciduous Forest (MSDF), Dry Semi-deciduous Forest (DSDF) and Savannah ecological zones in both Ghana and Côte d’Ivoire for the study. A single set of parameters could be used explicitly to predict stem profile of any teak tree, irrespective of country, eco-climatic zone, edaphic variables, site index, tree age, stand density and tree competition. The model efficiency and root mean square error (in relative diameter) were calculated to be 0.97 and 0.053, respectively. The relative position of the forks along the stem bole, with respect to total tree height, was highly variable and did not follow any particular trend, except higher value for the first fork in the Moist Evergreen Forest zone. However, average tree height to the first fork decreased along the ecological gradient from MEF, MSDF and DSDF to Savannah. The extent of diameter reduction due to the forks could be predicted. Relative tree form for zero-forked, one-forked and two-forked trees was calculated to be 0.39, 0.36 and 0.33, respectively. Relative loss of stem volume due to one fork and two forks was estimated to be 6.5 and 13.9%, respectively. The measured stem volume when related to the corresponding predicted value yielded coefficient and intercept not significantly different from unity and zero, respectively, with an r² value of 0.97.     

寒地粳稻不同杂种优势组合碳氮代谢关键酶活性比较分析

选用产量性状杂种优势有显著差异的4个粳稻杂交组合,分析分蘖期氮代谢关键酶活性和灌浆过程中碳氮代谢关键酶活性及其与产量的关系.结果表明,在分蘖期,高亲优势正向组合的氮代谢关键酶活性显著或极显著高于高亲优势负向组合;在灌浆过程中,高亲优势正向组合的籽粒谷氨酰胺合成酶活性、叶片蛋白水解酶活性、籽粒可溶性淀粉合成酶活性和ADPG焦磷酸化酶活性显著或极显著高于高亲优势负向组合.灌浆过程中碳氮代谢关键酶活性与千粒重,单株产量等呈不同程度正相关.     

Multidisciplinary assessment of agricultural innovation and its impact: a case study of lowland rice variety WITA 9 in Côte d’Ivoire

ABSTRACT

Information on comprehensive evaluation of agricultural innovations is often limited. This study provides an overview of multidisciplinary evaluation of a lowland rice variety, WITA 9 (released in Côte d’Ivoire in 1998), with respect to its agronomic performance, grain quality, resistance to diseases, adoption by farmers, impact on productivity and farmers’ income, and marketability. WITA 9 had the highest paddy yield among the tested varieties including an international check (IR 64) and recently developed varieties adapted to this country. WITA 9 had a higher amylose content (26–28%) than others tested. This study confirmed its resistance to bacterial leaf blight, Rice yellow mottle virus (RYMV), and rice blast. A household survey showed that the adoption rate was 24%, its paddy yield advantage was 0.7 t ha^–1, and its adoption increased farmer’s income by US$ 91 ha^–1 per season. A market study showed that consumers’ willingness to pay was higher for WITA 9 than any other locally produced rice variety and comparable to imported rice in one of two markets. We conclude that WITA 9 is an ideal innovation for enhancing productivity and rice import substitution in Côte d’Ivoire. An effective seed delivery system and enhancing farmers’ and consumers’ awareness of this variety are vital for accelerating impact.     

Pesticide Application Equipment

Abstract

Studies on the use of 22 chemical attractants for Glossina tachinoides were undertaken in Côte d'Ivoire following earlier work on G. m. morsitans and G. pallidipes in Zimbabwe. While catches of G. m. morsitans and G. pallidipes increased by several times when traps were baited with some of these substances, catches of G. tachinoides were only marginally increased. G. tachinoides is slightly attracted by octenol and acetone, alone or in combination, and its response to CO₂ is much weaker than that of the species tested in Zimbabwe. Phenol and indol mixtures both showed dose‐response relationships with catch. The indols were more potent in the lowest of the tested dosages (catch increase of 52%, P < 0001) whereas the phenols showed better attractiveness in their higher concentrations (catch increase of 42%, P < 0.05). Odour is probably less important in host finding for the riverine species G. tachinoides than it is for the savanna species studied in Zimbabwe.