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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.
Nicola M. Hall Bocary Kaya Jan Dick Ute Skiba Amadou Niang Ramadjita Tabo 《Biology and Fertility of Soils》2006,42(3):224-230
The impacts of fallow on soil fertility, crop production and climate-forcing gas emissions were determined in two contrasting
legumes, Gliricidia sepium and Acacia colei, in comparison with traditional unamended fallow and continuous cultivation systems. After 2 years, the amount of foliar
material produced did not differ between the two improved fallow species; however, grain yield was significantly elevated
by 55% in the first and second cropping season after G. sepium compared with traditional fallow. By contrast, relative to the unamended fallow, a drop in grain yield was observed in the
first cropping season after A. colei, followed by no improvement in the second. G. sepium had higher foliar N, K and Mg, while A. colei had lower foliar N but higher lignin and polyphenols. In the third year after fallow improvement, a simulated rainfall experiment
was performed on soils to compare efflux of N2O and CO2. Improved fallow effects on soil nutrient composition and microbial activity were demonstrated through elevated N2O and CO2 efflux from soils in G. sepium fallows compared with other treatments. N2O emissions were around six times higher from this nitrogen-fixing soil treatment, evolving 69.9 ngN2O–N g−1soil h−1 after a simulated rainfall event, compared with only 8.5 and 4.8 ngN2O–N g−1soil h−1 from soil under traditional fallow and continuous cultivation, respectively. The findings indicate that selection of improved
fallows for short-term fertility enhancement has implications for regional N2O emissions for dry land regions. 相似文献
4.
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
5.
Amadou Traoré Luis J. Royo Adama Kaboré Lucía Pérez-Pardal Isabel álvarez Iván Fernández Laya Sawadogo Hamidou H. Tamboura Félix Goyache 《Tropical animal health and production》2012,44(7):1469-1472
A total of 162 individuals, belonging to three Burkinabé and one Niger sheep populations, were analysed for prion protein (PrP) gene polymorphism at codons 136, 154 and 171. The ARQ allele was the most frequent in both the Burkinabé (86.7%) and the Niger (67.5%) sheep populations. The highly sensitive allele VRQ was not found in the sampled individuals. The highly resistant ARR allele was in very low frequency in the Burkina-Sahel (4.4%) and Mossi (3.2%) populations and was not present in the Djallonké and Touareg populations. Only 4 out of 15 possible PrP genotypes were identified in the sampled individuals. No favourable ARR/ARR genotypes were found in either of the breeds. Sequencing a subgroup of the samples allowed the identification of other five polymorphisms on the PrP gene sequence at codons 116, 138, 151, 237 and 240. The very low frequency of the ARR allele in the West African sheep should dissuade the implementation of a preventive selection programme aimed to increase resistance to scrapie, to avoid an extreme erosion of the genetic stock. 相似文献
6.
Fatou Ndoye Aboubacry Kane Niokhor Bakhoum Arsène Sanon Dioumacor Fall Diégane Diouf Samba Ndao Sylla Amadou Mustapha Bâ Mame Ourèye Sy Kandioura Noba 《Agroforestry Systems》2013,87(4):941-952
The benefits of inoculation with six arbuscular mycorrhizal fungi (AMF) isolates (Glomus aggregatum, G. fasciculatum, G. intraradices, G. manihotis, G. mosseae, and G. verriculosum) were investigated on seedlings of Acacia senegal (L.) Willd., a multipurpose tree legume highly valued for arabic gum production. Mycorrhizal root colonization, plant growth and relative mycorrhizal dependency (RMD) were measured in A. senegal seedlings growing in soils from three geographical sites in Senegal (Dahra, Bambey and Goudiry) and two soil conditions (sterilized vs unsterilized) in the glasshouse. The impact of inoculation on mycorrhizal root colonization and plant growth depended on AMF isolates, soil origins and soil conditions. Mycorrhizal root colonization and plant growth were increased in sterilized soils regardless of soil origin and AMF isolates. The degree of RMD of A. senegal seedlings varied with soil origin, soil condition and AMF isolates. A. senegal showed the highest RMD values, reaching a maximum of 45 %, when inoculated with G. manihotis. However, in unsterilized soils, no significant effect of AMF inoculation on plant growth was observed despite significant root colonization with certain AMF isolates in Dahra and Goudiry soils. This indicates that the most infective AMF isolates were not the most effective and unsterilized soils may contain effective mycorrhizal propagules. In conclusion, it is important to consider the native mycorrhizal component of the soils before harnessing mycorrhizal inoculation programs for sustainable agroforestry systems. 相似文献
7.
Adama Sanou Amadou Dicko Kadiatou R. Sow Arthur Djibougou Antoinette Kabore Bassirou Diarra Arsne K. Ouedraogo Dezemon Zingue Moumini Nouctara Zekiba Tarnagda 《The Onderstepoort journal of veterinary research》2021,88(1)
Bovine tuberculosis (bTB) is a zoonotic, infectious, chronic and contagious disease, caused by Mycobacterium bovis that mainly affects cattle. This pathology has a negative impact on animals and animal products trade. Unfortunately, in Burkina Faso where agriculture and livestock sectors represent around 80% of the socio-economic activities, the real situation of the disease is not well known especially in small ruminants and swine. Thus, our study focused on both the epidemiology and the microbiological diagnosis of tuberculosis (TB) in small ruminants and pigs slaughtered at Bobo-Dioulasso abattoir. A prospective study was conducted between August 2017 and December 2017. Epidemiological data collection was performed during routine meat inspection; moreover, samples were taken and transported to the Bacteriology laboratory of Centre Muraz for microbiological analyses. This diagnosis consisted in search of Acid Fast Bacilli (AFB) using the hot Ziehl–Neelsen staining. Out of a total of 14 648 small ruminants and 2430 pigs slaughtered during the study period, 156 and 17 had lesions suggestive of bTB with prevalence of 1.07% and 0.7%, respectively. Females and those between 2 and 4 years old were mainly infected. The most affected organs were: lungs, liver, spleen and lymph nodes. Finally, microscopy revealed 43.35% (75/173) of positive cases for AFB. These results confirm the presence of bTB in small ruminants and pigs in Burkina Faso. Efforts must still be made in the fight against this zoonosis in order to limit its economic and public health impacts. 相似文献
8.
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
9.
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
10.
Our study aimed to assess the effect of dual inoculation with the selected Rhizobium strain KWN35 and the arbuscular mycorrhizal isolate BEG 176 (Glomus etunicatum) on the growth of Calliandra
calothyrsus cultivated under irrigation in the field in Senegal (Dakar) over a period of 24 months. Although plants inoculated with both
microsymbionts grew better (height and root collar diameter) than plants from three other inoculation treatments (control,
single inoculation with KWN35 or BEG 176), these results were not statistically different except at 1 and 5 months after field
transplantation. KWN35 was present in a relatively high percentage of nodules harvested from plants inoculated with this rhizobial
strain either alone or with mycorrhiza (approximately 60% and 40% 1 and 2 years after field transplantation respectively).
The percentage of mycorrhizal root infections was around 60% in the inoculated plants after 12 months with significantly higher
N, P and K foliar contents of trees compared with the non-inoculated controls. However, as for nodulation, by 24 months after
transplantation, there were no significant differences between treatments. We conclude that field inoculation of C. calothyrsus with Rhizobium strain KWN35 and arbuscular mycorrhizal isolate BEG 176 did not have a long-lasting effect on the growth of trees, even when
a majority of nodules were occupied by the inoculated rhizobia and the roots infected by the mycorrhiza. Several reasons can
be postulated for these results, such as a possible effect of soil fertility on the efficiency of the nodules. 相似文献