Community water management to intensify agricultural productivity in the polders of the coastal zone of Bangladesh

Paddy and Water Environment - Most of the lands of the southern coastal zone of Bangladesh are protected from tidal flooding and storm surges by embankments constructed during the 1960s and 1970s,...     

Endosperm Texture in Wheat

One of the fundamental means of classifying wheat is through its endosperm texture. It impacts significantly on the milling process affecting among other things flour particle size and milling yield. Hardness in wheat is largely controlled by genetic factors but it can be affected by the environment and factors such as moisture, lipid, and pentosan content. The principal genetic locus controlling endosperm texture in wheat, Ha, is located on the chromosome 5D. At this locus several genes, notably the puroindolines, have been identified. Puroindolines are the major components of the 15 kDa protein band associated with starch granules that is more abundant in soft wheats than in hard. Recently the puroindolines have been shown to enhance grain hardness in rice. In this review we discuss the structure of hard and soft wheat endosperm with particular emphasis on when differences in endosperm texture can be detected in the developing seed. The role of the environment and other factors that may affect the endosperm texture is also examined together with the role of the puroindoline genes at theHa locus. Finally, we compare endosperm hardness in wheat and in barley.     

Potential of weed seedbanks for managing weeds: a review of recent New Zealand research

Weed seedbanks are the primary source of weeds in cultivated soils. Some knowledge of the weed seedbank may therefore be appropriate for integrated weed management programs. It would also be very useful in planning herbicide programs and reducing the total herbicide use. However, a number of problems are inherent in the estimation of the seedbank size for arable weeds that usually have annual life cycles. In a long-term research project we have investigated the dynamics of weed seedbanks in corn fields for the past 8 years. Specific studies have included (i) developing cheap and efficient methods for estimating the weed seedbank; (ii) developing guidelines for efficient soil sampling (including the number and size of samples); (iii) influence of cultivation methods on weed seed distribution; (iv) mapping the spatial variability of the seedbank; (v) estimating the rate of seedbank decline for certain weed species; and (vi) assessing the potential of using the weed seed content in the soil to predict future weed problems. This paper reviews and summarizes the results of our research on the above aspects. The strong correlation between seedlings emerged in the greenhouse and seeds extracted in the laboratory for the most abundant weed species has demonstrated the potential for using the weed seed content of the soil to predict future weed infestations. The next step is to establish correlations with field emergence under commercial conditions using the sampling guidelines developed in our studies. Subsequently, we aim to offer the weed seedbank estimation as a commercial service to farmers for planning the most appropriate weed management options.     

Guided bone regeneration with beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone membrane in partial defects of canine humerus

This study was performed to evaluate the effect of beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone (TCP/PLGC) membrane in the repair of partial bone defects in canine proximal humerus. Three adult mixed-breed dogs were used during the experimental period. The length of the defect was quarter of the full length of humerus, and width of the defect was quarter of middle diameter of the lateral aspect of humerus. The humeri of each dog were divided into treatment (TCP/PLGC) and control groups. The defect was covered with TCP/PLGC membrane in treatment group. To evaluate regeneration of the bone, computerized tomography (CT) and histopathologic examination were performed. The radiopaque lines were appeared at the original defect sites in TCP/PLGC group but below the original site in control at 4th week. Radiopacity and thickness of the defect sites, and radiopaque lines were more increased at 8th week than those of 4th week. Histopathologic findings revealed fibrous connective tissue migration into the defect and the migration inhibited the structure of new cortex to be placed in the original level in control whereas new cortex growth was found in the level of original line in TCP/PLGC group. However, the new cortical bone in the TCP/PLGC group was thinner and less organized than the adjacent intact cortex, and the amount of new cancellous bones were also scanty. The result suggested that TCP/PLGC membrane is a good guided bone regeneration material to restore the original morphology of humerus in partial defect.     

Effect of Soil Moisture on Relative Leaf Water Content, Chlorophyll, Proline and Sugar Accumulation in Wheat

The responses of four wheat ( Triticum aestivum L.) varieties to soil moisture were determined by measuring plant parameters such as relative leaf water content (RLWC) and the chlorophyll, proline and sugar contents of the leaf over two seasons. Two levels of irrigation treatments were adopted: irrigated and rainfed. The rainfed plants had consistently higher amounts of proline and sugar but lower RLWC and chlorophyll content. As drought intensified, differences between the irrigated and the rainfed plants with respect to all of these characters increased. The RLWC values of the irrigated plants were significantly higher in the morning but lower values were found at noon, showing some recovery in the afternoon.     

The establishment and development of Haemonchus contortus in goats

Twelve goats were inoculated with 40,000 third-stage Haemonchus contortus larvae and two were killed on each of Days 4, 7, 11, 14, 18 and 21 after inoculation (DAI). The number of worms that established, and the site of development were recorded. More worms established in the fundic, than in the middle or pyloric thirds of the abomasum. Early development occurred within the mucosa; emergence into the lumen started between 7 and 11 days after infection. By 4 DAI, all worms had completed the third moult to the L4 stage. At 11 DAI the majority of the worms were adults. A mean of 13.2% of the female worms had eggs in their uteri at 18 DAI; by 21 DAI more than half of the female worms had eggs in their uteri. The development of H. contortus was essentially similar to that described in sheep.     

Antibacterial activity and cytotoxicity of extractives from Ravenia spectabilis

A methanolic extract of Ravenia spectabilis, an isolated alkaloid, arborinine plus a fraction comprising arborinine and gamma-fagarine (VLC), showed mild to significant in vitro antibacterial activity. In a brine shrimp lethality bioassay, the extract and the fraction were found to exhibit moderate cytotoxicity having LC50 of 76.26 microg/ml and 14.98 microg/ml, respectively.     

Antibacterial activity of Vitex trifolia.

The petroleum ether and ethanol extracts of Vitex trifolia leaves exhibited moderate inhibiting activity against both gram-positive and gram-negative bacteria.     

孟加拉涝原地区村林居住的宗教社团偏爱的乔木和灌木树种及使用的造林材料研究

2002年1月至6月对孟加拉涝原地区两个不同的宗教部落(印度教和穆斯林教)的传统家园森林进行了探索性研究，包括印度教和穆斯林教社团对树种(乔木和灌木)的偏爱度、类似性、造林材料及来源、植树地点和间距。研究发现Mangifera indica作为乔木树种，Ocimum sanctum作为灌木树种为印度教社团最喜爱的树种；Artocarpus heterophyllus和Lawsonia inermis分别为穆斯林社团最喜爱乔木树种和灌木树种。两中不同宗教社团选择乔木数种的相同性为86．57％，灌木树种为78．48％。两个宗教部落使用种子和苗木作为造林材料最多。乔木树种的造林材料主要来自家园(39％)灌木树种主要来自自然界(40％)。表3参27。     

Antibacterial compounds from the flowers of Alangium salviifolium

1-Methyl-1H-pyrimidine-2,4-dione and 3-O-beta-D-glucopyranosyl-(24beta)-ethylcholesta-5,22,25-triene, isolated from the flowers of Alangium salviifolium, showed remarkable antibacterial activities against a number of Gram-positive and Gram-negative bacterial species.