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1.
Veronica R Alava Emilia T Quinitio Jennete B de Pedro Flora Mae P Priolo Zenith Gaye A Orozco & Mathieu Wille 《Aquaculture Research》2007,38(14):1468-1477
Wild‐caught and pond‐reared female mud crab Scylla serrata at different stages of ovarian maturation were collected from Samar and Capiz, Philippines. Crabs were categorized into five stages according to the external morphological and microscopic appearance of the most advanced oocytes. The ovaries, hepatopancreas, muscle and newly spawned eggs (NSE) were analysed for lipid class components and fatty acids. Total lipid was higher in pond‐reared than in wild‐caught crabs but increased with ovarian maturation in both groups. Ovarian lipid peaked at the fully mature stage, coinciding with a decline in hepatopancreatic and muscle lipids. Lipid levels declined significantly in spent females. The tissues contained elevated highly unsaturated fatty acids such as arachidonic (20:4n‐6), eicosapentaenoic (20:5n‐3) and docosahexaenoic (22:6n‐3) acids, but at higher levels in late maturing and fully mature ovaries and in NSE. The type of lipid class and fatty acid components in mature ovaries as well as in NSE are generally considered to be indicative of their importance in reproductive physiology and embryonic and larval development. 相似文献
2.
The aim of this study was to understand the ±45 ° directional off-axis tensile properties of the developed two dimensional (2D) multistitched multilayer E-glass/polyester woven composites. It was found that the off-axis tensile strength of the unstitched structure was slightly higher than those of the multistitched structures. The reason was that the multistitching process caused the filament breakages. It was also found that when the stitching direction and stitching density in structures increased, their off-axis tensile modulus decreased. Therefore, stitching directions, stitching density and stitching yarn on the composite structures were considered as important parameters. All structures under the off-axis tensile load had normal deformation, or angular deformation or shrinkage in width. In addition, both the normal deformation and the shrinkages in width occurred in most of the two and four directional stitched structures. On the other hand, four directional Kevlar® 129 yarn dense stitched E-glass/polyester structure showed only shrinkage in width after angular deformation. This could be considered as a new failure mode because of the multistitching. These results indicated that the stitching directions and density generally influenced the off-axis tensile properties of the multistitched E-glass/polyester woven composites. 相似文献
3.
Dhollander S Bos J Kora S Sanneh M Gaye M Leak S Berkvens D Geerts S 《Veterinary parasitology》2005,130(1-2):1-8
West African Dwarf goats (WADs) and their Saanen crosses were experimentally infected with Trypanosoma congolense. No significant differences were found between trypanosome parasitaemia and antibody response of the crossbred and WAD goats. Neither the WAD goats nor the Saanen crosses were able to control the drop in PCV following trypanosome infection. The level of anaemia caused by the trypanosome infection was similar in the two breeds during the trial. Based on these findings, no difference in tolerance or susceptibility to T. congolense could be demonstrated between the WAD goats and their Saanen crosses. Although the weight of all goats increased during the trial, the crosses gained significantly more weight than the WAD goats. The trypanosome infection reduced the growth rate of both breeds, but this reduction was not statistically significant. Crossbreeding trypanotolerant WADs with trypanosusceptible Saanen goats might, therefore, be an effective means of increasing productivity. 相似文献
4.
Ousmane Diankha Aliou Ba Patrice Brehmer Timothée Brochier Bamol Ali Sow Modou Thiaw Amadou Thierno Gaye Fambaye Ngom Hervé Demarcq 《Fisheries Oceanography》2018,27(4):351-365
We investigate Sardinella aurita and Sardinella maderensis recruitment success relative to the variability of oceanographic conditions in Senegalese waters using generalized additive models (GAM). Results show that recruitment of both species is marked by a strong intra‐annual (seasonal) variation with minimum and maximum in winter and summer, respectively. Their interannual variations are synchronous until 2006 (recruitment decreasing), while from 2007 there is no synchrony. The model developed shows that sardinella recruitment variability is closely related to the tested environmental variables in the study area. However, the key environmental variables influencing the recruitment success are different for both species: the Coastal Upwelling Index and the sea surface temperature for S. aurita and S. maderensis, respectively. We report that recruitment success of S. aurita and S. maderensis are associated with distinct ranges of sea surface temperature, upwelling intensity, wind‐induced turbulence, concentration of chlorophyll‐a and north Atlantic oscillation index. Considering food security and socio‐economic importance of both stocks, we recommend that consideration is given to the environmental variability in the small pelagic fish national management plans, particularly in the context of climate change. 相似文献
5.
Gaye Yolacan 《Fibers and Polymers》2009,10(5):625-635
The effects of alkali (aqueous NaOH and KOH solutions) pre-treatment on dye exhaustion, color values, color fastness, tensile and surface properties of lyocell yarns were investigated. Dye exhaustion and color yield of lyocell yarns increased by increasing alkali concentrations. The lyocell yarns showed weight loss due to the decrease in carboxyl groups during alkali pre-treatment. The tensile strengths of lyocell yarns decreased with the increase of alkali concentrations because of the decrement of yarn diameter by weight loss the open twist spirals, and the increased volume of lyocell yarns after alkali pre-treatment. The washing and perspiration fastness results of untreated lyocell yarns were better than alkali pre-treated lyocell yarns, while the light fastness results of untreated and alkali pre-treated samples were similar. 相似文献
6.
针对Inconel 718合金材料加工中不断提高的表面质量需求,研究了采用磁性复合流体(Magneticcompound fluid)抛光Inconel718合金材料的加工工艺.根据磁性复合流体抛光原理搭建Inconel718合金抛光实验平台,进行不同抛光方向、抛光时间、抛光转速等工艺参数下的Inconel718合金抛... 相似文献
7.
Dhollander S Jallow A Mbodge K Kora S Sanneh M Gaye M Bos J Leak S Berkvens D Geerts S 《Preventive veterinary medicine》2006,75(3-4):152-162
The objective of this study was to provide epidemiological information of equine trypanosomosis in the Central River Division (CRD) of The Gambia. Therefore, 2285 consultations records of equines, admitted in a gate-clinic at Sololo in CRD, were studied retrospectively. The data were recorded in the period between September 1995 and July 2002 and comprised consultations of 2113 horses and 172 donkeys.
‘Trypanosome infection’ was the most frequently diagnosed condition and accounted for 61% of the cases. Horses were more frequently diagnosed with trypanosome infections than donkeys (p < 0.001), with an occurrence of 63% compared to 43% in donkeys. In both horses and donkeys, trypanosome infections were mainly due to Trypanosoma congolense (64%) and T. vivax (32%). There was no difference observed in the occurrence of trypanosome infections in male or female donkeys (p = 0.585), but there were more female (67.8%) horses observed with trypanosome infections than male horses (60.7%; p = 0.003). There was no difference observed in the occurrence of trypanosome infections in donkeys older or younger than 1 year (p = 0.130), but more older horses (63.2% >1 year) were observed with trypanosome infections than young horses (54.5% <1 year; p = 0.033).
The number of donkeys and horses with trypanosome infections decreased during the rainy season (June–September).
The majority of equines that were admitted with trypanosome infections were severely anaemic. The average packed cell volume (PCV) declined with increasing parasitaemia (p = 0.006).
Seventy-four percent of the farmers’ predictions of trypanosome infections in their equines were confirmed by darkground-microscopy. That proved that farmers had a fairly accurate knowledge of the diseases affecting their equines.
The treatments executed at the gate-clinic were generally effective. The few (0.4%) relapses of the T. vivax infections that were previously treated with diminazene aceturate in this study were not sufficient to prove drug resistance.
The study showed that the analysis of consultation records at a gate-clinic can provide complementary information to conventional epidemiological studies in the same research area. 相似文献
8.
The African rice Oryza glaberrima, traditionally cultivated since more than 3.500 years, is of poor agronomic performance but resistant/tolerant to various
stresses and diseases. The introduction of these characters into O. sativa cultivars is difficult since crossing barriers cause spikelet sterility in F1. Backcrossing can restore fertility and recently
facilitated the development of fertile O. glaberrima × O. sativa ssp. japonica hybrid progenies for rain fed systems. With the objective to gain access to African rice germplasm for improvement of irrigated
rice, crosses were performed with eighteen O. glaberrima and twenty O. sativa ssp. indica accessions. In total about one hundred F1-hybrid grains were obtained. The F1 plants were all completely sterile and backcrossing
(BC) to O. sativa was performed in order to restore spikelet fertility. Monitoring of Tog5681 × IR64 hybrid progenies under field conditions
revealed a broad genetic diversity within the BC1 and BC2 populations. Some BC1 and BC2 progeny plants outperformed the O. sativa parent, indicating that the heterozygocity level and complementary gene action after two backcrosses are still sufficient
to positively influence plant vigor. Spikelet fertility of progenies was highly variable, but almost complete fertility was
already observed within the BC1F2 population. High spikelet fertility was preserved in one out of two analyzed BC1F3 families and inmost of the BC2F3 families. The ability to restore spikelet fertility within few generations and the potential of the genetic diversity present
in interspecific progenies facilitates the development of plant types specifically designed for the African irrigated and
lowland environment.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
Daouda Sidibé Haby Sanou Zewge Teklehaimanot Dianda Mahamadi Souleymane Koné 《Agroforestry Systems》2012,85(3):519-528
Pot experiments were conducted in a nursery in 2008 in Mali to study the effect of mycorrhizal symbionts on the growth and root infection of Ziziphus mauritiana and Tamarindus indica seedlings in unsterile soils. Three treatments were used and consisted of two types of inoculum (Glomus aggregatum, G. fasciculatum) and an uninoculated control. The seedlings were non-destructively assessed each month, and an additional, destructive harvest was made, after 6 and 10?months for Z. mauritiana and T. indica respectively. Mycorrhizal inoculation had a more positive impact on the growth of Z. mauritiana than on T. indica. G. aggregatum significantly (P?<?0.01) improved the growth of Z. mauritiana seedlings. However, the growth of T. indica seedlings was significantly better in the control compared to the two types of inoculum used. This indicates that unsterile nursery soil may contain effective mycorrhizal propagules. The mean percentage of infection of Z. mauritiana seedlings (74%) was significantly higher than that of T. indica (57%). We conclude that mycorrhizal inoculation can improve both mycorrhizal infection and growth of Z. mauritiana seedlings in unsterile nursery soils. 相似文献
10.
Alizèta Sawadogo Estérer Nagalo Souleymane Nacro Mathurin Rouamba Marc Kenis 《Journal of insect science (Online)》2015,15(1)
The flea beetle Aphthona whitfieldi Bryant (Coleoptera: Chrysomelidae) is the main pest of the bioenergy crop Jatropha curcas L. (Euphorbiaceae) in Burkina Faso and several other West African countries. Adults severely defoliate plants, resulting in seedling mortality, poor growth, and low yields. To study the population dynamics of the pest in the Sissili Province of Burkina Faso, 12 sites were monitored weekly during a year and 31 sites were inspected for damage at the peak period of insect abundance. The effect of cropping systems (hedge, intercropping, and monoculture) and surrounding vegetation on population densities of A. whitfieldi was assessed. Beetles were rarely found in the dry season and peaked in the second half of the rainy season. The cropping system did not significantly influence the abundance and attack level. In contrast, the close vicinity of fallow lands seems to increase damage levels. Many aspects of the biology and ecology of A. whitfieldi remain to be investigated before sustainable control methods can be developed. However, this study already allows us to propose recommendations for further research on management. 相似文献