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101.
The present investigation examined histogenesis of epithelial, stromal and angiogenic elements of the prenatal camel permanent or metanephric kidney. The primitive metanephros was first observed at the 13‐mm crown vertebral rump length (CVRL) stage as an ovoid structure composed of a centrally located epithelial ureteric bud and peripheral circumscribed masses of undifferentiated mesenchymal cells. The first morphological evidence of glomerulogenesis was observed at the 28‐mm CVRL stage. Developing renal corpuscles became obvious at the 35‐mm CVRL stage. At the 60‐mm CVRL stage, the epithelial renal pelvis gave rise to tubular branches that extended towards the cortical zone. These branches represented the presumptive collecting ducts. Differentiation of renal tubules into the proximal and distal convoluted tubules was observed at the 95‐mm CVRL stage. At the 130‐mm CVRL stage, the renal medulla was clearly delineated into medullary pyramids, which in association with the corresponding cortical caps formed the morphological basis of the renal lobar formation. A gradual nephrogenic decline was noticed from the 940‐mm CVRL on; however, the process of nephrogenesis persisted throughout all the studied foetal stages.  相似文献   
102.
This study was designed to study the effect of short‐term supplementation with rumen‐protected fat during the late luteal phase on reproduction and metabolism of sheep during breeding season. Seventy‐six ewes (Rahmani, Barki and Awassi × Barki) were allocated to two groups considering genotype: the control ewes (C‐group) received a maintenance diet, and the fat‐supplemented ewes (F‐group) received the maintenance diet plus 50 g/head/day of rumen‐ protected fat (Megalac) for 9 days during which oestrus was synchronized. The latter had been accomplished using double intramuscular injection of prostaglandin F (PGF) 11 days apart. Ovarian activity, serum concentration of cholesterol, glucose, insulin and reproductive performance variables were recorded. Data were analysed considering treatment (group) and genotype. Supplementation had positive effects on the overall mean serum concentrations of cholesterol (p < 0.05), glucose (p < 0.05) on day 6 of nutritional treatment and insulin (p = 0.07) on day 8. Fat supplementation did not affect the total number of follicles, follicle populations and ovulation rate. However, fat‐supplemented Rahmani ewes tended to have higher ovulation rate compared with other breeds (treatment × breed interaction, p = 0.06). Treatment also did not affect the mean concentration of serum estradiol or progesterone. Supplemented ewes had higher conception (p = 0.06) and lambing rates (p < 0.05) compared with control. In conclusion, short‐term supplementation with rumen‐protected fat as a source of energy around breeding time improved metabolism, conception and lambing rates of ewes without effects on steroidogenic capacity and ovarian activity being apparent.  相似文献   
103.
Indigenous communities in the Chittagong Hill Tracts (CHT) of Bangladesh had been conserving small patch of forests, commonly called village common forests (VCFs), especially for drinking water and non-timber forest produce. The size of VCFs has been decreasing, due to increasing population and conversion of forests for shifting cultivation. To restore the degraded forest resources and conserve the forest ecosystems in the VCF of the CHT, an intervention was undertaken in Bandarban, Bangladesh by Arannayk Foundation, an organization established jointly by the Government of Bangladesh and the United States of America. A training program on leadership, organizational development and alternative income generating activities was implemented to build the capacity of the members of the VCF management committee. The impact of the interventions was measured at the end of third year. Incomes of VCF-dependent communities were found to increase with resultant reduction of their dependence on VCFs. The intervention encouraged women’s participation in forest management and facilitated a written format of the constitution of the VCF management. The study identified that more training and awareness-raising activities are needed to ensure sustainability of the interventions. Mobilizing funds for the communities for sustainable alternative livelihoods was found effective. Appropriate compensation for conservation was found to make the restoration and conservation activities sustainable.  相似文献   
104.
This study was conducted to investigate the effects of increasing levels of extracts of Byrsonima crassifolia, Celtis pallida, Enterolobium cyclocarpum, Fraxinus excelsior, Ficus trigonata, Phoradendrom brevifolium and Prunus domestica on in vitro gas production (GP) and ruminal fermentation of a high concentrate diet. Plant extracts were prepared at 1 g dry matter (DM)/8 mL of solvent mixture (methanol : ethanol : water, 1:1:8) and added at levels of 0, 0.6, 1.2 and 1.8 mL/g DM of a high concentrate diet. In vitro GP was recorded at 2, 4, 6, 8, 10, 12, 24, 48 and 72 h of incubation. Increasing addition of extracts linearly increased (P < 0.001), the GP24, GP48 and GP72 (mL/g DM), and linearly decreased (P < 0.001), the discrete GP lag time. Moreover, increasing extract doses linearly increased (P < 0.001) the asymptotic GP and decreased (P < 0.001) the rate of GP. GP6 was not impacted by treatments and GP12 increased linearly (P = 0.01) with increasing addition of extracts. Rumen pH declined linearly (P < 0.05) with increasing doses of extracts added. As no interactions (P > 0.05) occurred between the extracts and doses, it could be conclude that all extracts positively modified rumen fermentation at doses of 1.2 to 1.8 mL extract/g diet DM.  相似文献   
105.
The development of a reliable methodology for spawning of African catfish, Clarias gariepinus without the use of hormone injections would greatly improve the prospects of aquaculture in Africa. Earlier work has shown that it is possible to produce C. gariepinus fingerlings by subjecting the broodfish to a physical stress of reduced water depth and/or increased temperature. The hypothesis that C. gariepinus could be induced to spawn through a combined physical stress of lowered water level and increased stocking density was tested in concrete tanks. Three water levels (25, 50 and 75 cm) and three stocking densities (2, 4 and 6 pairs of broodfish at a 1:1 sex ratio in each hapa) were tested. Water depth in the tanks and brood fish density in the hapas affected spawning success. The percentage of spawning females was significantly higher when broodfish were stocked at 2 and 4 pairs in each hapa at water levels of 25 cm or 50 cm. There was no significant difference in spawning response between the 25 and 50 cm depths while a significant difference was seen between the 75 cm and both 25 and 50 cm depths. The results indicate optimum levels and densities for enhancing spawning success in C. gariepinus.  相似文献   
106.
The present review article is intended to direct attention to the technological advances made in the 2010–2014 quinquennium for the isolation and manufacture of nanofibrillar chitin and chitosan. Otherwise called nanocrystals or whiskers, n-chitin and n-chitosan are obtained either by mechanical chitin disassembly and fibrillation optionally assisted by sonication, or by e-spinning of solutions of polysaccharides often accompanied by poly(ethylene oxide) or poly(caprolactone). The biomedical areas where n-chitin may find applications include hemostasis and wound healing, regeneration of tissues such as joints and bones, cell culture, antimicrobial agents, and dermal protection. The biomedical applications of n-chitosan include epithelial tissue regeneration, bone and dental tissue regeneration, as well as protection against bacteria, fungi and viruses. It has been found that the nano size enhances the performances of chitins and chitosans in all cases considered, with no exceptions. Biotechnological approaches will boost the applications of the said safe, eco-friendly and benign nanomaterials not only in these fields, but also for biosensors and in targeted drug delivery areas.  相似文献   
107.

In the North Nile Delta of Egypt, the impacts of overplanting paddy rice on water delivery performance have not been discussed quantitatively. Further, the amount of water that could have been saved if farmers would follow the planned area is unknown. In this study, water delivery performance was assessed by comparison of actual paddy rice planting and the government’s planned conditions. For both conditions, performance indicators relating to adequacy, equity, and dependability were analyzed across six locations in conjunction with the branch canal water level in 2013 and 2014. Based on the difference between the actual water supply and planned water demand, the amount of water that could have been saved for downstream uses was calculated. The average adequacy for the investigation period was good at one location, fair at 2 locations, and poor at 3 locations in both years. Further, adequacy under both actual and planned conditions was poor in late July at all locations. The planned adequacy and dependability downstream and equity among locations improved compared to the actual condition in both years. Under the condition that paddy rice area is the upper limit planned by the government, about 12.3% and 9.6% of water could be potentially saved in each year. The difference between actual and planned water delivery performance is caused by the branch canal’s low water level. Control of overplanting paddy rice and coordination of water distribution among water user associations would improve stable water level in the canal and, eventually, water delivery performance.

  相似文献   
108.
Alternate two different modes of actions of green chemicals: spinosad & methoxyfenozide to combat the lesser date moth, Batrachedra amydraula and the Almond moth, Cadra cautella Walk on dates in Dakhla Oasis, New Valley, Egypt were done in 2010 and 201 I. Based on infestation of the early insect pest B. amydraula, the three-rotation program with basic 1st spray of spinosad 24 SC at 20 mL/100 L showed insignificant difference. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozide 24 SC at 15 mL/100 L with two-week interval showed zero infestation and 1.8% at the last sample of 2010 and 2011, respectively. Based on infestation of the late insect pest, Cadra spp., tlhe same previous trend of the three-rotation results. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozid 24 SC at 15 mL/100 L with three-week interval indicated less than 1% and 1% infestation during harvest for 2010 and 201 l, respectively. The last reflected important value when storing the fruit. Both products proved to be working under dry hot high temperatures.  相似文献   
109.
Monitoring and assessment of agricultural land degradation is of vital importance for better land and water management planning and reclamation. It requires setting baseline information and basic analysis at specific time and space. About 33 geo-referenced soil sampling spots were selected in two agricultural production locations in the Kingdom of Bahrain to assess the status and preliminary causes of land degradation. Soil samples were taken from 13 sites in Diraz location while 19 samples were taken from Budayyi location. The samples were taken to 90 cm depth at 30 cm intervals. Standard procedures were followed to determine soil physiochemical properties. In addition, field observations on farm condition, distance from the sea, method of irrigation and irrigation water source were taken. Some of the soil samples were deliberately taken from outside the irrigated basins among trees compared with samples taken from inside the actively growing area for comparison. The results indicated that the salinity level was significantly (P 〈 0.001) higher at the 0-30 cm soil depth compared with 30-60 cm or 60-90 cm depths in both locations. The distance from the sea did not show clear correlation with surface soil salinity in Budayyi area compared with Diraz. Both locations showed significantly higher salinity levels on samples taken outside the actively growing areas compared with those taken from within. The effect is more prominent at the 0-30 cm depth. The observed variability on salinity levels may be attributed to farm management practices and deteriorating quality of ground water. Thus, agricultural land degradation in Bahrain cannot be attributed to ground water deterioration alone. The use of tertiary treated sewage water (TSE) may ease the pressure on ground water, but the pH of the TSE should be carefully monitored and managed with proper studies on leaching requirements to avoid further salinity complications.  相似文献   
110.
  1. Many river rehabilitation projects have been criticized for failing to meet their goals or for being insufficiently monitored. There is, therefore, an urgent need to develop robust approaches for assessing treatment efficacy and thus guide the increasing investment in rehabilitation.
  2. Instream biotopes (formerly called ‘functional habitats’ or ‘mesohabitats’ by different authors) and their macroinvertebrate assemblages were used to assess the effectiveness of entire-channel hydromorphological rehabilitation of a 1.8-km stretch of a lowland stream through the town of Market Harborough, Leicestershire, UK.
  3. The project successfully enhanced the physical diversity, measured in the rehabilitated reach as the coefficients of variability for channel water depth and width, wet surface area, number of instream biotopes, and biotope diversity.
  4. The project also enhanced the biodiversity conservation value, measured as macroinvertebrate total density, total biomass, richness, diversity, Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness, EPT diversity, EPT count%, and EPT biomass%, all of which significantly increased following rehabilitation. Chironomidae count% and biomass% significantly decreased following rehabilitation. Rehabilitation was also successful in significantly increasing macroinvertebrate shredder, scraper, and filter-feeder group density.
  5. Changes in the macroinvertebrate community metrics in the rehabilitated reach were related significantly to changes in the percentages of cover of instream biotopes and increases in biotope diversity in the rehabilitated reach.
  6. Macroinvertebrate structural and functional metrics can provide quantitative data for assessing reach-level rehabilitation outcomes, if samples are collected in a pre-defined sampling protocol stratified at the instream biotope level.
  7. The practical implications of this work are that the design of rehabilitation projects, if based upon the recreation of biotope heterogeneity, will succeed in improving biological value and restoring the area to near naturalness if a suitable upstream source of macroinvertebrates for natural recolonization is available. The study shows that the concept of biotopes has an important role to play in river conservation management.
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