Maize constitutes one of the most important crops in Niger’s fight for food security, and it is cultivated in all regions of the country. However, maize cultivation is declining due to low soil fertility. This study ...Maize constitutes one of the most important crops in Niger’s fight for food security, and it is cultivated in all regions of the country. However, maize cultivation is declining due to low soil fertility. This study focused on evaluating the impact of fertilizers on maize plant production in Zinder. The fertilizer effect was evaluated based on 21 quantitative and 9 qualitative descriptors proposed by IBPGR and CIMMYT 1991. The experiment was conducted during the rainy season in the experimental domain of Université André Salifou following randomized complete block designs with three repetitions. Seven fertilizer treatments, including two organic, two mineral, two combinations of fertilizers, and a control treatment, were applied. The analysis shows that fertilizers had positive effects on the earliness and productivity of the selected variety. The best yield of dry corn cob (7480 kg/ha) was recorded on organic fertilizer of composted poultry manure, which is equal to 4.8 times that obtained with the control (1561 kg/ha), followed by the mineral fertilizer NPK combined with composted cow dung with 6395.231 kg/ha. Therefore, the use of fertilizers could be an appropriate alternative to overcome the negative consequences of yield declines in the corn production system in the Zinder region.展开更多
Geopolymers are an alternative to Portland cement, well known for their contribution to greenhouse gas emissions. Finding materials that can validly replace Portland cement is a challenge. It is in this logic that thi...Geopolymers are an alternative to Portland cement, well known for their contribution to greenhouse gas emissions. Finding materials that can validly replace Portland cement is a challenge. It is in this logic that this work was undertaken with the objective of characterizing two local clay resources of Togo as raw materials for geopolymers. The physico-chemical properties of these clays were determined by characterization using X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric (TGA) and elemental analysis (ICP-OES). The results show that these clays contain kaolinite and therefore can be used in the formulation of geopolymers. The characterized clays underwent heat treatments transforming the crystalline phases into more reactive amorphous phases and then were activated by an alkaline solution in order to formulate the geopolymer materials. These elaborated materials were analyzed by Fourier transform infrared to identify the types of bonds formed. The results of these analyses show that these two local clays are well suited to be used in synthesizing geopolymers. Our future work will focus on the constraints of consolidation as well as the mechanical properties of these geopolymer materials.展开更多
Catfishes belonging to the genus <em>Chrysichthys</em> are generally important fish species in inland water bodies of Africa because of their high commercial value. Among them, <em>C.</em> <...Catfishes belonging to the genus <em>Chrysichthys</em> are generally important fish species in inland water bodies of Africa because of their high commercial value. Among them, <em>C.</em> <em>nigrodigitatus</em> could represent, at certain periods of the year the highest biomass of the littoral ichthyofauna, accounting for 17 to 43.8% of total catches. In this paper, its diet in the hydrosystem Lake Togo-Lagoon of Aného was investigated focusing on how differences in diet and food consumption are related to size, season and sexual maturity. A total of 195 males and 137 females were sampled from January to December 2017. The digestive tract of each individual was dissected and its content was analyzed, using indexes of stomach contents analysis method. Diet variability in relation to season and biometric <em></em>parameters was also studied. About 99 stomachs were empty with an overall vacuity index of 29.82%. However, vacuity index was found to vary in relation to fish size and months. The fish has been found to be omnivorous with a carnivorous tendency consuming a wide range of prey items (H = 3.34). Juvenile and adult freshwater clams (<em>Galatea paradoxa</em>) were the numerical dominant preys (%N = 44%) while the penaeid shrimps (<em>Farfantepenaeus notialis</em>) with an annual frequency of occurrence (Fo) of 49.36% and all species confused of fish (33.91%) were the most preferred preys. The index of relative importance (IRI) reveals that freshwater clam (40.49%), penaeid shrimps (35.85%) and all species confused of fish (14.58%) were the most important preys of <em>C. nigrodigitatus</em>. The dominance of Malacostraca and Mollusca in the diet of <em>C. nigrodigitatus</em> in the hydrosystem Lake Togo-Lagoon of Aného is likely one of the more important considerations for future management plans.展开更多
The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include orga...The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.展开更多
Bambara groundnut (Vigna subterranea (L.) Verdc.) has economic importance for the producers and the traders as cash crop since it generates substantial income for households in Niger. The objective of this study was t...Bambara groundnut (Vigna subterranea (L.) Verdc.) has economic importance for the producers and the traders as cash crop since it generates substantial income for households in Niger. The objective of this study was to assess eight (8) Bambara groundnut morphotype from Université André Salifou de Zinder in Niger Republic by their morphological and agronomic characters. The experiment was conducted in a randomized complete block design with three replications during the rainy season of 2020-2021. Data were collected on the Number of leaves, Plant height (cm), Growth habit (cm), Terminal leaflet length, Terminal leaflet width, Number of nodes/stem, Number of stems/plant, Number of pods/plant, Weight of 100 pods (g), Weight of 100 seeds (g), Length of seeds (mm), Width of seeds (mm), Weight of seeds/Plot (kg). There were significant differences for all characters, except Number of leaves, Terminal leaflet length, Terminal leaflet width, Length of seeds (mm) Weight of 100 pods (g), Weight of 100 seeds (g). The morphotypes UZ-VZ-04, UZ-VZ-03, UZ-VZ-06, UZ-VZ-02 and UZ-VZ-05 have demonstrated good performance for grain weight per plot and can be useful for a breeding program.展开更多
Green coal or bio-coal is coal produced with rich biodegradable materials, elaborated from agricultural and household residues with a high percentage of carbon. This green charcoal (fuel briquettes) is an alternative ...Green coal or bio-coal is coal produced with rich biodegradable materials, elaborated from agricultural and household residues with a high percentage of carbon. This green charcoal (fuel briquettes) is an alternative to charcoal. Well known for its contribution to greenhouse gas emissions, charcoal is one of the causes of tree felling. The valorization of waste by the manufacture of biofuels could be an alternative to the use of charcoal. The general objective of the present study is the valorization of nine biomasses from Togo as raw materials. Specifically, physico-chemical characteristics such as dehydration, acidity, and conductivity were determined. Information on the structure and composition of the biomass was found. These data on the nature of the biomass were found through the use of Fourier Transform Infrared (FTIR) and Thermogravimetry (TGA). The promising results inform on the nature of the analyzed samples and allow the selection of the best biomass which would give an important thermal conductivity for the manufacture of the briquettes, but also of the binders to be used according to the physico-chemical characteristics like the pH.展开更多
</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="...</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:""><span style="font-family:Verdana;"> is a giant land snail taxa endemic to the northern sectors of the Monts Togo, which has been regarded as full species or subspecies of the highly variable, widespread </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> (L.). To address this issue, samples of snails were taken throughout the distribution range of the two taxa in the Dahomey Gap (West Africa) and separated into 112 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> and 141 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> according to color of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">columella and parietal wall. Radulae were compared and shell characters of these 2 species were evaluated through </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">traditional morphometric method. The results indicate that the species cannot be distinguished by overall shell size and radular morphology, but they exhibit significant differences in shell shape and meristic traits. The typical </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">with vinaceous-red columella</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">has a low-spired shell and an expanded aperture (globose shape) whereas </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> has a higher-spired and smaller aperture (a fusiform shape). We suggest that local environmental effects are probably the causes of morphological divergence between the two taxa. It is likely that peripheral populations of the typical form of </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> would have isolated and developed in the drier facies of the humid forest that individualized in the northern sector of the mountains after the arid or interpluvial period of Holocene. In addition, we find that </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> meets the criteria B2ab</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">(ii, iii) to categorize as “Endangered”. However, whether this latter should be considered as separate species cannot be decided at the current state of knowledge.展开更多
The omnivorous fish species, <i>C. nigrodigitatus</i> feeds mainly on benthic organisms and may therefore consume contaminated food throughout its food web. This can lead to the bioaccumulation of contamin...The omnivorous fish species, <i>C. nigrodigitatus</i> feeds mainly on benthic organisms and may therefore consume contaminated food throughout its food web. This can lead to the bioaccumulation of contaminants such as trace elements in their tissues. However, fish consumption is a major pathway of human exposure to contaminants which may cause public health problems. The aim of the present study is to assess trace elements contamination in some species from the food web of <i>C. nigrodigitatus</i>. For this, 10 main food items of the silver catfish were collected at two sites from February to July 2017 and analyzed using an Atomic Absorption Spectrometer coupled with a hydride and cold vapour generator. The concentrations of trace elements varied greatly from one species to another and within each species. These values ranged from 0.007 mg/kg for Hg in C hippos to 354.84 mg/kg for Mn in <i>P. fusca</i>. The most contaminated species by trace elements were benthic organisms: <i>M. perna</i> (Cd, Pb, Hg), <i>Pagurus</i> sp. (Cr, Ni, Cu, Zn), <i>G. paradoxa</i> (As) and <i>P. fusca</i> (Mn). The average concentrations of trace elements found in species were, for the most part, above WHO standards except Hg in <i>M. perna</i> and <i>G. paradoxa</i>. The water-based bioconcentration factors (BCFw) reach 92.58 for Cd, 44.72 for Pb, 382.49 for Hg and 1514.34 for As in <i>M. perna</i>. It is therefore necessary to pay particular attention to this ecosystem and to put in place a better management plan.展开更多
The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and conti...The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and continuously.The mechanical properties and surface appearance of the heated samples were also investigated.Continuous and intermittent microwave drying kinetic experiments were conducted at a frequency of 2.45 GHz using a microwave laboratory oven at 300,500,and 1000 watts.Drying rate curves indicated three distinct phases of MWH.Increasing the microwave power with a shorter drying time led to rapid increases in internal temperature and water evaporation rates of the heated samples.Mechanical results indicated that samples heated under continuous MW(Microwave)power at 300 watts had a modulus of rupture(MOR)and modulus of elasticity(MOE)in three static bending tests higher than 29%and 36%,respectively,than samples heated at 1000 watts.Intermittent microwave heating(IMWH)of samples at 300 and 1000 watts produced the highest MOR and MOE values of 31%and 51%,respectively,unlike those heated under continuous microwave heating(CMWH).External qualitative observation showed that samples heated at high microwave power had severe surface checks.These defects were missing when using IMWH.An analysis of variance(ANOVA)showed that mechanical properties were linked to both microwave power level and the heating scenario,except for MOR in axial compression under CMWH.展开更多
The diversity of Botryosphaeriaceae species associated with“Botryosphaeria dieback”of grapevine was investigated in 18 vineyards in Sardinia,Italy.Lasiodiplodia isolates obtained from different woody hosts including...The diversity of Botryosphaeriaceae species associated with“Botryosphaeria dieback”of grapevine was investigated in 18 vineyards in Sardinia,Italy.Lasiodiplodia isolates obtained from different woody hosts including holm oak,sweet orange and broom bush in Italy,Algeria and Tunisia were also characterized.Morphological and cultural characteristics as well as ITS and EF1-αsequence data were used to identify the fungal isolates.Forty-eight botryosphaeriaceous isolates were obtained from 113 symptomatic grapevine samples,from which ten species were identified.Diplodia seriata was the dominant species(25%of isolates),followed by Neofusicoccum parvum(21.7%).Two species,Diplodia olivarum and D.africana are reported for the first time on grapevine.In addition,two new species namely Lasiodiplodia mediterranea sp.nov.from grapevine,holm oak and sweet orange and Lasiodiplodia exigua sp.nov.from broom bush are described.In artificial inoculation experiments conducted on excised green grapevine shoots and lignified canes as well as holm oak seedlings,L.mediterranea was shown to be an aggressive pathogen.展开更多
Polycyclic aromatic hydrocarbons(PAHs)and their oxygenated derivates(O-PAHs)are identified in soils and groundwater of industrialized sites and contribute to the risk for Humans and the Environment.Nevertheless,data a...Polycyclic aromatic hydrocarbons(PAHs)and their oxygenated derivates(O-PAHs)are identified in soils and groundwater of industrialized sites and contribute to the risk for Humans and the Environment.Nevertheless,data are scarce in literature concerning their retention and transfer in soils and no soil-water partition coefficients are available for these compounds.Sorption of two PAHs,fluorene and acenaphthene and two O-PAHs,9H-fluorenone and dibenzofuran onto two soils with different organic carbon contents was evaluated and compared by determining their sorption isotherms.Effect of ionic strength and liquid to solid ratio,on fluorene and fluorenone sorption was also evaluated.Sorption equilibrium is achieved within less than 24 hr of mixing and linear sorption models best fit the isotherm data.Acenaphthene and dibenzofuran are similarly sorbed onto the soil.KD of fluorene is higher than the one of fluorenone,showing a smaller affinity of fluorenone towards the solid phase.This means that O-PAH could form larger contamination plumes in groundwater than PAHs.Decreasing the L/S ratio from 100 to 50 and 30,increases the sorption of fluorenone onto the soil by 56% and 67%respectively,while the sorption of fluorene is slightly increased.Increasing the ionic strength of the aqueous phase also modifies the sorption of fluorenone,contrary to the sorption of fluorene which is slightly affected.展开更多
文摘Maize constitutes one of the most important crops in Niger’s fight for food security, and it is cultivated in all regions of the country. However, maize cultivation is declining due to low soil fertility. This study focused on evaluating the impact of fertilizers on maize plant production in Zinder. The fertilizer effect was evaluated based on 21 quantitative and 9 qualitative descriptors proposed by IBPGR and CIMMYT 1991. The experiment was conducted during the rainy season in the experimental domain of Université André Salifou following randomized complete block designs with three repetitions. Seven fertilizer treatments, including two organic, two mineral, two combinations of fertilizers, and a control treatment, were applied. The analysis shows that fertilizers had positive effects on the earliness and productivity of the selected variety. The best yield of dry corn cob (7480 kg/ha) was recorded on organic fertilizer of composted poultry manure, which is equal to 4.8 times that obtained with the control (1561 kg/ha), followed by the mineral fertilizer NPK combined with composted cow dung with 6395.231 kg/ha. Therefore, the use of fertilizers could be an appropriate alternative to overcome the negative consequences of yield declines in the corn production system in the Zinder region.
文摘Geopolymers are an alternative to Portland cement, well known for their contribution to greenhouse gas emissions. Finding materials that can validly replace Portland cement is a challenge. It is in this logic that this work was undertaken with the objective of characterizing two local clay resources of Togo as raw materials for geopolymers. The physico-chemical properties of these clays were determined by characterization using X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric (TGA) and elemental analysis (ICP-OES). The results show that these clays contain kaolinite and therefore can be used in the formulation of geopolymers. The characterized clays underwent heat treatments transforming the crystalline phases into more reactive amorphous phases and then were activated by an alkaline solution in order to formulate the geopolymer materials. These elaborated materials were analyzed by Fourier transform infrared to identify the types of bonds formed. The results of these analyses show that these two local clays are well suited to be used in synthesizing geopolymers. Our future work will focus on the constraints of consolidation as well as the mechanical properties of these geopolymer materials.
文摘Catfishes belonging to the genus <em>Chrysichthys</em> are generally important fish species in inland water bodies of Africa because of their high commercial value. Among them, <em>C.</em> <em>nigrodigitatus</em> could represent, at certain periods of the year the highest biomass of the littoral ichthyofauna, accounting for 17 to 43.8% of total catches. In this paper, its diet in the hydrosystem Lake Togo-Lagoon of Aného was investigated focusing on how differences in diet and food consumption are related to size, season and sexual maturity. A total of 195 males and 137 females were sampled from January to December 2017. The digestive tract of each individual was dissected and its content was analyzed, using indexes of stomach contents analysis method. Diet variability in relation to season and biometric <em></em>parameters was also studied. About 99 stomachs were empty with an overall vacuity index of 29.82%. However, vacuity index was found to vary in relation to fish size and months. The fish has been found to be omnivorous with a carnivorous tendency consuming a wide range of prey items (H = 3.34). Juvenile and adult freshwater clams (<em>Galatea paradoxa</em>) were the numerical dominant preys (%N = 44%) while the penaeid shrimps (<em>Farfantepenaeus notialis</em>) with an annual frequency of occurrence (Fo) of 49.36% and all species confused of fish (33.91%) were the most preferred preys. The index of relative importance (IRI) reveals that freshwater clam (40.49%), penaeid shrimps (35.85%) and all species confused of fish (14.58%) were the most important preys of <em>C. nigrodigitatus</em>. The dominance of Malacostraca and Mollusca in the diet of <em>C. nigrodigitatus</em> in the hydrosystem Lake Togo-Lagoon of Aného is likely one of the more important considerations for future management plans.
文摘The main cash crop in Togo is cotton, with about 70% of agricultural exports. This crop is very dependent on the use of chemical inputs, in particular pesticides. Pesticides used in cotton farming in Togo include organochlorines, triazines, organophosphates and pyrethroids. We conducted a study on the impact of these pesticide use, in particular organochlorines and triazines, on cotton farming soils. We chose the Plateaux region (southern Togo) as the study area because of its high cotton production. Analysis was carried out on crop soil samples at the 0 - 20 cm horizon. Several pesticide residues were found: simazine (0.051 to 0.103 μg/Kg soil);atrazine (0.149 to 0.197 μg/Kg soil);lindane (0.259 to 0.672 μg/Kg soil);β-endosulfan (1.37 to 5.727 μg/Kg soil);dieldrin (0.063 to 1.16 μg/Kg soil);endrin (0.512 μg/Kg soil), Heptachlor (0.489 to 1.243 μg/Kg soil);Heptachlor epoxide (0.928 to 1.633 μg/Kg soil);[2,4'DDT] (0.257 μg/Kg soil);[4,4'DDE] (0.262 μg/Kg soil). These results show pesticide contamination of cotton farming soils.
文摘Bambara groundnut (Vigna subterranea (L.) Verdc.) has economic importance for the producers and the traders as cash crop since it generates substantial income for households in Niger. The objective of this study was to assess eight (8) Bambara groundnut morphotype from Université André Salifou de Zinder in Niger Republic by their morphological and agronomic characters. The experiment was conducted in a randomized complete block design with three replications during the rainy season of 2020-2021. Data were collected on the Number of leaves, Plant height (cm), Growth habit (cm), Terminal leaflet length, Terminal leaflet width, Number of nodes/stem, Number of stems/plant, Number of pods/plant, Weight of 100 pods (g), Weight of 100 seeds (g), Length of seeds (mm), Width of seeds (mm), Weight of seeds/Plot (kg). There were significant differences for all characters, except Number of leaves, Terminal leaflet length, Terminal leaflet width, Length of seeds (mm) Weight of 100 pods (g), Weight of 100 seeds (g). The morphotypes UZ-VZ-04, UZ-VZ-03, UZ-VZ-06, UZ-VZ-02 and UZ-VZ-05 have demonstrated good performance for grain weight per plot and can be useful for a breeding program.
文摘Green coal or bio-coal is coal produced with rich biodegradable materials, elaborated from agricultural and household residues with a high percentage of carbon. This green charcoal (fuel briquettes) is an alternative to charcoal. Well known for its contribution to greenhouse gas emissions, charcoal is one of the causes of tree felling. The valorization of waste by the manufacture of biofuels could be an alternative to the use of charcoal. The general objective of the present study is the valorization of nine biomasses from Togo as raw materials. Specifically, physico-chemical characteristics such as dehydration, acidity, and conductivity were determined. Information on the structure and composition of the biomass was found. These data on the nature of the biomass were found through the use of Fourier Transform Infrared (FTIR) and Thermogravimetry (TGA). The promising results inform on the nature of the analyzed samples and allow the selection of the best biomass which would give an important thermal conductivity for the manufacture of the briquettes, but also of the binders to be used according to the physico-chemical characteristics like the pH.
文摘</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:""><span style="font-family:Verdana;"> is a giant land snail taxa endemic to the northern sectors of the Monts Togo, which has been regarded as full species or subspecies of the highly variable, widespread </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> (L.). To address this issue, samples of snails were taken throughout the distribution range of the two taxa in the Dahomey Gap (West Africa) and separated into 112 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> and 141 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> according to color of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">columella and parietal wall. Radulae were compared and shell characters of these 2 species were evaluated through </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">traditional morphometric method. The results indicate that the species cannot be distinguished by overall shell size and radular morphology, but they exhibit significant differences in shell shape and meristic traits. The typical </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">with vinaceous-red columella</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">has a low-spired shell and an expanded aperture (globose shape) whereas </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> has a higher-spired and smaller aperture (a fusiform shape). We suggest that local environmental effects are probably the causes of morphological divergence between the two taxa. It is likely that peripheral populations of the typical form of </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> would have isolated and developed in the drier facies of the humid forest that individualized in the northern sector of the mountains after the arid or interpluvial period of Holocene. In addition, we find that </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> meets the criteria B2ab</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">(ii, iii) to categorize as “Endangered”. However, whether this latter should be considered as separate species cannot be decided at the current state of knowledge.
文摘The omnivorous fish species, <i>C. nigrodigitatus</i> feeds mainly on benthic organisms and may therefore consume contaminated food throughout its food web. This can lead to the bioaccumulation of contaminants such as trace elements in their tissues. However, fish consumption is a major pathway of human exposure to contaminants which may cause public health problems. The aim of the present study is to assess trace elements contamination in some species from the food web of <i>C. nigrodigitatus</i>. For this, 10 main food items of the silver catfish were collected at two sites from February to July 2017 and analyzed using an Atomic Absorption Spectrometer coupled with a hydride and cold vapour generator. The concentrations of trace elements varied greatly from one species to another and within each species. These values ranged from 0.007 mg/kg for Hg in C hippos to 354.84 mg/kg for Mn in <i>P. fusca</i>. The most contaminated species by trace elements were benthic organisms: <i>M. perna</i> (Cd, Pb, Hg), <i>Pagurus</i> sp. (Cr, Ni, Cu, Zn), <i>G. paradoxa</i> (As) and <i>P. fusca</i> (Mn). The average concentrations of trace elements found in species were, for the most part, above WHO standards except Hg in <i>M. perna</i> and <i>G. paradoxa</i>. The water-based bioconcentration factors (BCFw) reach 92.58 for Cd, 44.72 for Pb, 382.49 for Hg and 1514.34 for As in <i>M. perna</i>. It is therefore necessary to pay particular attention to this ecosystem and to put in place a better management plan.
文摘The aim of this paper was to characterize through experiment the moisture and temperature kinetic behavior of Eucalyptus gomphocephala wood samples using microwave heating(MWH)in two scenarios:intermittently and continuously.The mechanical properties and surface appearance of the heated samples were also investigated.Continuous and intermittent microwave drying kinetic experiments were conducted at a frequency of 2.45 GHz using a microwave laboratory oven at 300,500,and 1000 watts.Drying rate curves indicated three distinct phases of MWH.Increasing the microwave power with a shorter drying time led to rapid increases in internal temperature and water evaporation rates of the heated samples.Mechanical results indicated that samples heated under continuous MW(Microwave)power at 300 watts had a modulus of rupture(MOR)and modulus of elasticity(MOE)in three static bending tests higher than 29%and 36%,respectively,than samples heated at 1000 watts.Intermittent microwave heating(IMWH)of samples at 300 and 1000 watts produced the highest MOR and MOE values of 31%and 51%,respectively,unlike those heated under continuous microwave heating(CMWH).External qualitative observation showed that samples heated at high microwave power had severe surface checks.These defects were missing when using IMWH.An analysis of variance(ANOVA)showed that mechanical properties were linked to both microwave power level and the heating scenario,except for MOR in axial compression under CMWH.
基金Antonio Deidda and Bruno Scanu gratefully acknowledge Sardinia Regional Government for the financial support of the PhD scholarship and research grant,respectively(P.O.R.Sardegna F.S.E.Operational Programme of the Autonomous Region of Sardinia,European Social Fund 2007–2013-Axis IV Human Resources,Objective l.3,Line of Activity l.3.1.).
文摘The diversity of Botryosphaeriaceae species associated with“Botryosphaeria dieback”of grapevine was investigated in 18 vineyards in Sardinia,Italy.Lasiodiplodia isolates obtained from different woody hosts including holm oak,sweet orange and broom bush in Italy,Algeria and Tunisia were also characterized.Morphological and cultural characteristics as well as ITS and EF1-αsequence data were used to identify the fungal isolates.Forty-eight botryosphaeriaceous isolates were obtained from 113 symptomatic grapevine samples,from which ten species were identified.Diplodia seriata was the dominant species(25%of isolates),followed by Neofusicoccum parvum(21.7%).Two species,Diplodia olivarum and D.africana are reported for the first time on grapevine.In addition,two new species namely Lasiodiplodia mediterranea sp.nov.from grapevine,holm oak and sweet orange and Lasiodiplodia exigua sp.nov.from broom bush are described.In artificial inoculation experiments conducted on excised green grapevine shoots and lignified canes as well as holm oak seedlings,L.mediterranea was shown to be an aggressive pathogen.
基金the French National Institute for Industrial and Environment and Risks, and the French National Agency for Ecological Transition for their financial support
文摘Polycyclic aromatic hydrocarbons(PAHs)and their oxygenated derivates(O-PAHs)are identified in soils and groundwater of industrialized sites and contribute to the risk for Humans and the Environment.Nevertheless,data are scarce in literature concerning their retention and transfer in soils and no soil-water partition coefficients are available for these compounds.Sorption of two PAHs,fluorene and acenaphthene and two O-PAHs,9H-fluorenone and dibenzofuran onto two soils with different organic carbon contents was evaluated and compared by determining their sorption isotherms.Effect of ionic strength and liquid to solid ratio,on fluorene and fluorenone sorption was also evaluated.Sorption equilibrium is achieved within less than 24 hr of mixing and linear sorption models best fit the isotherm data.Acenaphthene and dibenzofuran are similarly sorbed onto the soil.KD of fluorene is higher than the one of fluorenone,showing a smaller affinity of fluorenone towards the solid phase.This means that O-PAH could form larger contamination plumes in groundwater than PAHs.Decreasing the L/S ratio from 100 to 50 and 30,increases the sorption of fluorenone onto the soil by 56% and 67%respectively,while the sorption of fluorene is slightly increased.Increasing the ionic strength of the aqueous phase also modifies the sorption of fluorenone,contrary to the sorption of fluorene which is slightly affected.
