PaD7

The deep assessment of agricultural mechanization inside developing countries could help for local action-taking. This study investigates the use of tractors between the poles of agricultural development (PAD) in Benin Republic. Using a multi-stage random sampling procedure and a questionnaire, 203 tractor users were surveyed in 43 municipalities distributed across the seven PADs of the country. Kruskal-Wallis tests were carried out to compare the different poles of agricultural development based on the mechanization level and tractor performances. Student-Newman-Keuls tests were used to structure the means of these variables. The results show a significant variation (P < 0.05) of the mechanization level between the PADs. Apart PAD1, all the poles use greater than 60 % manual equipment. Animal-drawn is most implemented in the northern part of the country (PAD1; 2 and 3). The use of tractors is lower over the country, and the PAD2 and PAD3 are the most users. From PAD4 to PAD7, the combination of manual tillage with animal power or tractor is not well represented, indicating manual tillage-based agriculture in these poles. In general, 53.20% of the users do not have a tractor parking and the repair center is quasi-absent (97.54 %). PAD2; 4 and 3 are most disc plow users. Mechanical sowing is more observed in PAD2 and 7 and absent in PAD1; 3 and 4. Moreover, the harvester is present in PAD2; 4; 6, and 7. On average, the highest mechanized area was 134.56 ha from PAD3, whereas, the lowest, 12.00 ha was found in PAD7. PAD7 spends more on plowing (47670 FCFA) than the other poles. The mechanized plowing is most slower in PAD7 (3.53 h/ha) while much faster at the PAD2 (1.96 h/ha). These results could help decision-makers for accurate actions taking to advocate for agricultural mechanization sectors in the country based on the weakness of each pole of agricultural development.

Human adenovirus type 7 DNA was extracted from purified virus cultured in WI-38 cells. The essential fragment (68-100 mu) of Ad7 DNA was used for constructing a non-defective Ad7 vector termed as pAd7 delta E3. The vector was characterized by a deletion at the E3 region that contains a multicloning site for the insertion of foreign genes. A helper-independent adenovirus type 7-beta-galactosidase recombinant was established. The recombinant contains the beta-galactosidase gene flanked by CMV early promoter and SV40 poly A signal. The constructed recombinant virus showed efficient capacity in expressing the foreign gene, beta-galactosidase.

The use of dilution culture techniques to cultivate saccharolytic bacteria present in the anoxic soil of flooded rice microcosms allowed the isolation of three new strains of bacteria, typified by their small cell sizes, with culturable numbers estimated at between 1.2 x 10(5) and 7.3 x 10(5) cells per g of dry soil. The average cell volumes of all three strains were 0.03 to 0.04 microns3, and therefore they can be termed ultramicrobacteria or "dwarf cells." The small cell size is a stable characteristic, even when the organisms grow at high substrate concentrations, and thus is not a starvation response. All three strains have genomic DNA with a mol% G+C ratio of about 63, are gram negative, and are motile by means of a single flagellum. The three new isolates utilized only sugars and some sugar polymers as substrates for growth. The metabolism is strictly fermentative, but the new strains are oxygen tolerant. Sugars are metabolized to acetate, propionate, and succinate. Hydrogen production was not significant. In the presence of 0.2 atm of oxygen, the fermentation end products or ratios did not change. The phylogenetic analysis on the basis of 16S ribosomal DNA (rDNA) sequence comparisons indicates that the new isolates belong to a branch of the Verrucomicrobiales lineage and are closely related to a cloned 16S rDNA sequence (PAD7) recovered from rice paddy field soil from Japan. The isolation of these three strains belonging to the order Verrucomicrobiales from a model rice paddy system, in which rice was grown in soil from an Italian rice field, provides some information on the possible physiology and phenotype of the organism represented by the cloned 16S rDNA sequence PAD7. The new isolates also extend our knowledge on the phenotypic and phylogenetic depths of members of the order Verrucomicrobiales, to date acquired mainly from cloned 16S rDNA sequences from soils and other habitats.