Background: The investigation of toxin genes in strains involved in staphylococcal food poisoning contributes to food safety. The aim of this study was to isolate and identify enterotoxigenic Staphylococcus strains fr...Background: The investigation of toxin genes in strains involved in staphylococcal food poisoning contributes to food safety. The aim of this study was to isolate and identify enterotoxigenic Staphylococcus strains from dried, smoked, and braised fish sold in Ouagadougou markets. Methodology: Staphylococci were isolated using standard microbiology methods. Staphylococcus strains were identified using API Staph kit (Reference # 20500, BioMerieux S.A., Marcy l'Etoile, France). The molecular identification of isolated Staphylococcus aureus strains was specifically confirmed by PCR using the Staur4 and Staur6 primers. The genes encoding enterotoxins, enterotoxin-like toxins, exfoliative toxins, and TSST-1 toxin were detected by multiplex PCR using specific primers from Inquaba Biotec West Africa Ltd, Africa's Genomics Company. Results: The results of the microbiological quality assessment indicated that most of the samples analyzed were found to be of unsatisfactory microbiological quality according to the Staphylococcus aureus microbiological criteria (m = 102). Overall, only 12.55% of samples were satisfactory, while 97.45% were unsatisfactory. The STAPH API gallery allowed the identification of the following species: Staphylococcus aureus, Staphylococcus xylosus, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus lentus, Staphylococcus sciuri and Staphylococcus capitis. Of the 108 Staphylococcus isolates, 81 (75%) showed at least one (1) toxin gene. Among the 21 toxin genes tested in this study, 20 genes were detected in all strains analyzed. The staphylococcal toxin genes detected were present in both Staphylococcus aureus and the other coagulase-negative strains isolated in this study. In addition, these genes are found individually or in association in certain strains. The most frequent genes detected in toxin gene-positive strains were: the tsst-1 gene in 45 isolated strains (41.7%), sei (16/14.8%), seg (13/12%), ser (7/6.5%) sec (6/5.5%), and sea (5/4.6%) for staphylococcal enterotoxins, seln (14/12.9%), selq (8/7.4%), for enterotoxin-like toxin gene and eta (3/2.7%) for exfoliative toxin genes. Conclusion: This study highlighted the pathogenicity of Staphylococcus strains isolated from dried, smoked, and braised fish sold in Ouagadougou markets. Monitoring toxin-producing strains of Staphylococcus is invaluable for better prevention of food poisoning.展开更多
Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem functioning.In this study,we described the spatial-temporal characteristics of demersal fish communities al...Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem functioning.In this study,we described the spatial-temporal characteristics of demersal fish communities along a coastal habitat in Rongcheng Bay,Shandong Peninsula,China with both species-based and biological trait-based approaches.The field survey was carried out monthly using traps from April to October of 2018,and divided into three seasons(spring:April and May;summer:June,July and August;autumn:September,October and November).The study area included five distinct habitats:seagrass bed,natural rocky reef,bare sand,artificial reef together with natural rocky reef,and artificial reef together with bare sand.We analyzed the fish communities with three taxonomic diversity indices,including Shannon-Wiener,Simpson,and Pielou Evenness,as well as four functional diversity indices,including FRic,FEve,FDiv,and FDis,based on 7 functional groups which are categorized into 27 traits.The results showed that there were no significant differences in taxonomic diversity indices among different habitats in the three seasons.However,significant differences were found in the functional richness of fish communities among different habitats in three seasons.Seagrass bed represented the highest functional richness in spring and autumn.This study demonstrates that seagrass bed is very important in enhancing the functional diversity of fish communities in a complex habitat.The study also indicates that the combination of taxonomic diversity and functional diversity will provide a more detailed description of the characteristics of fish communities.展开更多
Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Te...Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.展开更多
Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African...Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.展开更多
This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochl...This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.展开更多
Background The development of a sustainable business model with social acceptance,makes necessary to develop new strategies to guarantee the growth,health,and well-being of farmed animals.Debaryomyces hansenii is a ye...Background The development of a sustainable business model with social acceptance,makes necessary to develop new strategies to guarantee the growth,health,and well-being of farmed animals.Debaryomyces hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i)promote cell proliferation and differen-tiation,ii)have immunostimulatory effects,iii)modulate gut microbiota,and/or iv)enhance the digestive function.To provide inside into the effects of D.hansenii on juveniles of gilthead seabream(Sparus aurata)condition,we inte-grated the evaluation of the main key performance indicators coupled with the integrative analysis of the intestine condition,through histological and microbiota state,and its transcriptomic profiling.Results After 70 days of a nutritional trial in which a diet with low levels of fishmeal(7%)was supplemented with 1.1%of D.hansenii(17.2×10^(5) CFU),an increase of ca.12%in somatic growth was observed together with an improve-ment in feed conversion in fish fed a yeast-supplemented diet.In terms of intestinal condition,this probiotic modu-lated gut microbiota without affecting the intestine cell organization,whereas an increase in the staining intensity of mucins rich in carboxylated and weakly sulphated glycoconjugates coupled with changes in the affinity for certain lectins were noted in goblet cells.Changes in microbiota were characterized by the reduction in abundance of several groups of Proteobacteria,especially those characterized as opportunistic groups.The microarrays-based transcrip-tomic analysis found 232 differential expressed genes in the anterior-mid intestine of S.aurata,that were mostly related to metabolic,antioxidant,immune,and symbiotic processes.Conclusions Dietary administration of D.hansenii enhanced somatic growth and improved feed efficiency param-eters,results that were coupled to an improvement of intestinal condition as histochemical and transcriptomic tools indicated.This probiotic yeast stimulated host-microbiota interactions without altering the intestinal cell organization nor generating dysbiosis,which demonstrated its safety as a feed additive.At the transcriptomic level,D.hansenii pro-moted metabolic pathways,mainly protein-related,sphingolipid,and thymidylate pathways,in addition to enhance antioxidant-related intestinal mechanisms,and to regulate sentinel immune processes,potentiating the defensive capacity meanwhile maintaining the homeostatic status of the intestine.展开更多
BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)emergency.However,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to...BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)emergency.However,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid abscess.Proper and timely management can help reduce complications,especially in elderly patients.CASE SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the condition.In the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her throat.Eventually,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a stripe.CONCLUSION If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the thyroid.To avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its removal.At the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.展开更多
Modern technology for developing new items made from renewable resources is becoming more and more popular as a result of rising environmental concern.Recently,contemporary polymer composites have included the hybridi...Modern technology for developing new items made from renewable resources is becoming more and more popular as a result of rising environmental concern.Recently,contemporary polymer composites have included the hybridization of natural fibers with synthetic ones,along with the inclusion of a variety of biowaste filler for developing sustainable goods.In this work,the kenaf/glass hybrid polyester composites are strengthened by the addition of fish scale(FS),which is taken from the fishs outermost layer of skin.Five different stacked-order laminates,such as KKKK,KGKG,GKKG,KGGK,and GGGG,are fabricated by using the hand lay-up method with four different weight concentrations of filler content:0%,5%,10%,and 15%.Mechanical possessions such as tensile,flexural,impact strength and micro-hardness have been evaluated through experimentation in accordance with ASTM standards.The experimental findings revealed that,the tensile strength and micro-hardness value of KGKG laminates with 15wt% of FS filler are found to be maximum of 118.72 MPa and 17.82 HV respectively which are 39.67%and 26.11%greater than that of KGKG laminates without FS filler.However,the flexural and impact strength of same laminates with 10 wt% FS filler exhibited a maximum value of 142.77 MPa and 62.08 kJ/m^(2).In order to corroborate its applicability for structural and building materials in open environment,the dimensional stability of the composite has been studied through moisture absorption test.The influences of FS filler loading on dimensional stability and resistance to moisture absorption capacity of laminates are also investigated.The experimental results reflected that the addition of FS-filler has significantly improved the dimensional stability of the laminates in moist environment by reducing the moisture absorption tendency.To further support the mode of failures,a fractography investigation of fractured surfaces was conducted.展开更多
The aim of this study of the Manantali dam reservoir is to investigate the biological quality of the water through inventories and analysis of the ichthyofauna and planktonic communities (zooplankton and phytoplankton...The aim of this study of the Manantali dam reservoir is to investigate the biological quality of the water through inventories and analysis of the ichthyofauna and planktonic communities (zooplankton and phytoplankton). Inventories of ichthyofauna and plankton communities were carried out quarterly from 2003 to 2022. The fish populations studied on the basis of bioindicators (species richness, diversity index, equitability index, diversification index) identified 29 species belonging to 10 families. The Cichlidae family is the most represented, while the Schilbeidae and Tetraodontioae families are less represented in terms of number of species. The species Hydrocynus forskalii and Brycinus nurse with relative abundances of 40.12% and 21.4% respectively, both from the family Alestidae, are the most abundant. The species H. forskalii has a frequency of occurrence of 100%. The specific diversity index of 2.9 and the equitability index of 0.6 show an average diversity of fish species. The diversification index of 2.9 indicates a theoretical number of habitats of 2 to 3. The planktonic community is made up of zooplankton and phytoplankton. The inventory of zooplankton shows the presence of 28 zooplankton species belonging to 9 families of the three zooplankton groups Rotifera, Cladocera and Copepoda. Analysis of the frequencies of occurrence of the various taxa showed that the characteristic species of Lake Manantali are the omnipresent rotifers Keratella cochlearis, Keratella quadrata and Trichocerca chattoni. For phytoplankton, the inventories carried out show the presence of 65 species belonging to 5 families (Chlorophycees, Diatomees, Dinophycees, Chrysophycees and Cyanophycees). An analysis of the frequency of occurrence of the various taxa shows that the characteristic species of Lake Manantali are Chlorophycees, with 7 species: Desmidium baileyi, Micrasterias alata, Sphaerocystis schroeteri, Spondylosium sp., Staurastrum heimii, Staurastrum subanchora, Staurodesmus wandae;Diatoms, with one species: Navicula sp. and Cyanophycees, with one species: Microcystis aeruginosa.展开更多
【目的】深化柑橘减数分裂粗线期染色体结构组成和配对分析。【方法】首次利用柑橘染色体全长特异寡核苷酸荧光原位杂交(oligo-fluorescence in situ hybridization,oligo-FISH)涂染探针,精准示踪鉴定沙田柚粗线期1号染色体的结构特征,...【目的】深化柑橘减数分裂粗线期染色体结构组成和配对分析。【方法】首次利用柑橘染色体全长特异寡核苷酸荧光原位杂交(oligo-fluorescence in situ hybridization,oligo-FISH)涂染探针,精准示踪鉴定沙田柚粗线期1号染色体的结构特征,比较其与有丝分裂间期细胞核、有丝分裂前中期和中期染色体的结构差异,并揭示粗线期全长染色体的同源配对。【结果】观测到同源配对的全长粗线期与有丝分裂中期较大染色质结构差异。经测定,柚粗线期1号染色体平均全长、长臂长、短臂长和臂比分别为中期的13.93倍、16.54倍、10.44倍和1.54倍,表现出更高FISH信号分辨率。检测到柚粗线期1号染色体着丝粒附近约3.01 Mb的探针信号缺失区。【结论】首次实现柑橘特定全长粗线期染色体的跟踪研究,为深入开展其结构和配对遗传利用的精准研究提供了新方法。展开更多
Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired ma...Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers.The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures.In particular,the double-Bouligand architecture can effectively deflect cracking paths,alleviate strain localization,and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite,representing a successful implementation of the property-optimizing mechanisms in fish scales.The strength of the composites,specifically the effect of their bioinspired architectures,was interpreted based on the adaptation of classical laminate theory.This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.展开更多
文摘Background: The investigation of toxin genes in strains involved in staphylococcal food poisoning contributes to food safety. The aim of this study was to isolate and identify enterotoxigenic Staphylococcus strains from dried, smoked, and braised fish sold in Ouagadougou markets. Methodology: Staphylococci were isolated using standard microbiology methods. Staphylococcus strains were identified using API Staph kit (Reference # 20500, BioMerieux S.A., Marcy l'Etoile, France). The molecular identification of isolated Staphylococcus aureus strains was specifically confirmed by PCR using the Staur4 and Staur6 primers. The genes encoding enterotoxins, enterotoxin-like toxins, exfoliative toxins, and TSST-1 toxin were detected by multiplex PCR using specific primers from Inquaba Biotec West Africa Ltd, Africa's Genomics Company. Results: The results of the microbiological quality assessment indicated that most of the samples analyzed were found to be of unsatisfactory microbiological quality according to the Staphylococcus aureus microbiological criteria (m = 102). Overall, only 12.55% of samples were satisfactory, while 97.45% were unsatisfactory. The STAPH API gallery allowed the identification of the following species: Staphylococcus aureus, Staphylococcus xylosus, Staphylococcus lugdunensis, Staphylococcus hominis, Staphylococcus haemolyticus, Staphylococcus lentus, Staphylococcus sciuri and Staphylococcus capitis. Of the 108 Staphylococcus isolates, 81 (75%) showed at least one (1) toxin gene. Among the 21 toxin genes tested in this study, 20 genes were detected in all strains analyzed. The staphylococcal toxin genes detected were present in both Staphylococcus aureus and the other coagulase-negative strains isolated in this study. In addition, these genes are found individually or in association in certain strains. The most frequent genes detected in toxin gene-positive strains were: the tsst-1 gene in 45 isolated strains (41.7%), sei (16/14.8%), seg (13/12%), ser (7/6.5%) sec (6/5.5%), and sea (5/4.6%) for staphylococcal enterotoxins, seln (14/12.9%), selq (8/7.4%), for enterotoxin-like toxin gene and eta (3/2.7%) for exfoliative toxin genes. Conclusion: This study highlighted the pathogenicity of Staphylococcus strains isolated from dried, smoked, and braised fish sold in Ouagadougou markets. Monitoring toxin-producing strains of Staphylococcus is invaluable for better prevention of food poisoning.
基金supported by funds from the National Natural Science Foundation of China(No.42076100)the Joint Funds of the National Natural Science Foundation of China(No.U2006214).
文摘Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem functioning.In this study,we described the spatial-temporal characteristics of demersal fish communities along a coastal habitat in Rongcheng Bay,Shandong Peninsula,China with both species-based and biological trait-based approaches.The field survey was carried out monthly using traps from April to October of 2018,and divided into three seasons(spring:April and May;summer:June,July and August;autumn:September,October and November).The study area included five distinct habitats:seagrass bed,natural rocky reef,bare sand,artificial reef together with natural rocky reef,and artificial reef together with bare sand.We analyzed the fish communities with three taxonomic diversity indices,including Shannon-Wiener,Simpson,and Pielou Evenness,as well as four functional diversity indices,including FRic,FEve,FDiv,and FDis,based on 7 functional groups which are categorized into 27 traits.The results showed that there were no significant differences in taxonomic diversity indices among different habitats in the three seasons.However,significant differences were found in the functional richness of fish communities among different habitats in three seasons.Seagrass bed represented the highest functional richness in spring and autumn.This study demonstrates that seagrass bed is very important in enhancing the functional diversity of fish communities in a complex habitat.The study also indicates that the combination of taxonomic diversity and functional diversity will provide a more detailed description of the characteristics of fish communities.
文摘Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively.
文摘Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.
文摘This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.
基金financed through the DIETAplus project of JACUMAR(Junta de Cultivos Marinos,MAPAMASpanish government),which is cofunded with FEMP funds(EU)+3 种基金funded by means of grants from the Spanish Government:PID2019-106878RB-I00 and IS was granted with a Postdoctoral fellowship(FJC2020-043933-I)support of Fondecyt iniciación(project number 11221308)Fondecyt regular(project number 11221308)grants(Agencia Nacional de Investigacióny Desarrollo de Chile,Government of Chile),respectivelythe framework of the network LARVAplus“Strategies for the development and im-provement of fish larvae production in Ibero-America”(117RT0521)funded by the Ibero-American Program of Science and Technology for Development(CYTED,Spain)。
文摘Background The development of a sustainable business model with social acceptance,makes necessary to develop new strategies to guarantee the growth,health,and well-being of farmed animals.Debaryomyces hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i)promote cell proliferation and differen-tiation,ii)have immunostimulatory effects,iii)modulate gut microbiota,and/or iv)enhance the digestive function.To provide inside into the effects of D.hansenii on juveniles of gilthead seabream(Sparus aurata)condition,we inte-grated the evaluation of the main key performance indicators coupled with the integrative analysis of the intestine condition,through histological and microbiota state,and its transcriptomic profiling.Results After 70 days of a nutritional trial in which a diet with low levels of fishmeal(7%)was supplemented with 1.1%of D.hansenii(17.2×10^(5) CFU),an increase of ca.12%in somatic growth was observed together with an improve-ment in feed conversion in fish fed a yeast-supplemented diet.In terms of intestinal condition,this probiotic modu-lated gut microbiota without affecting the intestine cell organization,whereas an increase in the staining intensity of mucins rich in carboxylated and weakly sulphated glycoconjugates coupled with changes in the affinity for certain lectins were noted in goblet cells.Changes in microbiota were characterized by the reduction in abundance of several groups of Proteobacteria,especially those characterized as opportunistic groups.The microarrays-based transcrip-tomic analysis found 232 differential expressed genes in the anterior-mid intestine of S.aurata,that were mostly related to metabolic,antioxidant,immune,and symbiotic processes.Conclusions Dietary administration of D.hansenii enhanced somatic growth and improved feed efficiency param-eters,results that were coupled to an improvement of intestinal condition as histochemical and transcriptomic tools indicated.This probiotic yeast stimulated host-microbiota interactions without altering the intestinal cell organization nor generating dysbiosis,which demonstrated its safety as a feed additive.At the transcriptomic level,D.hansenii pro-moted metabolic pathways,mainly protein-related,sphingolipid,and thymidylate pathways,in addition to enhance antioxidant-related intestinal mechanisms,and to regulate sentinel immune processes,potentiating the defensive capacity meanwhile maintaining the homeostatic status of the intestine.
文摘BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)emergency.However,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid abscess.Proper and timely management can help reduce complications,especially in elderly patients.CASE SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the condition.In the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her throat.Eventually,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a stripe.CONCLUSION If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the thyroid.To avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its removal.At the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.
文摘Modern technology for developing new items made from renewable resources is becoming more and more popular as a result of rising environmental concern.Recently,contemporary polymer composites have included the hybridization of natural fibers with synthetic ones,along with the inclusion of a variety of biowaste filler for developing sustainable goods.In this work,the kenaf/glass hybrid polyester composites are strengthened by the addition of fish scale(FS),which is taken from the fishs outermost layer of skin.Five different stacked-order laminates,such as KKKK,KGKG,GKKG,KGGK,and GGGG,are fabricated by using the hand lay-up method with four different weight concentrations of filler content:0%,5%,10%,and 15%.Mechanical possessions such as tensile,flexural,impact strength and micro-hardness have been evaluated through experimentation in accordance with ASTM standards.The experimental findings revealed that,the tensile strength and micro-hardness value of KGKG laminates with 15wt% of FS filler are found to be maximum of 118.72 MPa and 17.82 HV respectively which are 39.67%and 26.11%greater than that of KGKG laminates without FS filler.However,the flexural and impact strength of same laminates with 10 wt% FS filler exhibited a maximum value of 142.77 MPa and 62.08 kJ/m^(2).In order to corroborate its applicability for structural and building materials in open environment,the dimensional stability of the composite has been studied through moisture absorption test.The influences of FS filler loading on dimensional stability and resistance to moisture absorption capacity of laminates are also investigated.The experimental results reflected that the addition of FS-filler has significantly improved the dimensional stability of the laminates in moist environment by reducing the moisture absorption tendency.To further support the mode of failures,a fractography investigation of fractured surfaces was conducted.
文摘The aim of this study of the Manantali dam reservoir is to investigate the biological quality of the water through inventories and analysis of the ichthyofauna and planktonic communities (zooplankton and phytoplankton). Inventories of ichthyofauna and plankton communities were carried out quarterly from 2003 to 2022. The fish populations studied on the basis of bioindicators (species richness, diversity index, equitability index, diversification index) identified 29 species belonging to 10 families. The Cichlidae family is the most represented, while the Schilbeidae and Tetraodontioae families are less represented in terms of number of species. The species Hydrocynus forskalii and Brycinus nurse with relative abundances of 40.12% and 21.4% respectively, both from the family Alestidae, are the most abundant. The species H. forskalii has a frequency of occurrence of 100%. The specific diversity index of 2.9 and the equitability index of 0.6 show an average diversity of fish species. The diversification index of 2.9 indicates a theoretical number of habitats of 2 to 3. The planktonic community is made up of zooplankton and phytoplankton. The inventory of zooplankton shows the presence of 28 zooplankton species belonging to 9 families of the three zooplankton groups Rotifera, Cladocera and Copepoda. Analysis of the frequencies of occurrence of the various taxa showed that the characteristic species of Lake Manantali are the omnipresent rotifers Keratella cochlearis, Keratella quadrata and Trichocerca chattoni. For phytoplankton, the inventories carried out show the presence of 65 species belonging to 5 families (Chlorophycees, Diatomees, Dinophycees, Chrysophycees and Cyanophycees). An analysis of the frequency of occurrence of the various taxa shows that the characteristic species of Lake Manantali are Chlorophycees, with 7 species: Desmidium baileyi, Micrasterias alata, Sphaerocystis schroeteri, Spondylosium sp., Staurastrum heimii, Staurastrum subanchora, Staurodesmus wandae;Diatoms, with one species: Navicula sp. and Cyanophycees, with one species: Microcystis aeruginosa.
文摘【目的】深化柑橘减数分裂粗线期染色体结构组成和配对分析。【方法】首次利用柑橘染色体全长特异寡核苷酸荧光原位杂交(oligo-fluorescence in situ hybridization,oligo-FISH)涂染探针,精准示踪鉴定沙田柚粗线期1号染色体的结构特征,比较其与有丝分裂间期细胞核、有丝分裂前中期和中期染色体的结构差异,并揭示粗线期全长染色体的同源配对。【结果】观测到同源配对的全长粗线期与有丝分裂中期较大染色质结构差异。经测定,柚粗线期1号染色体平均全长、长臂长、短臂长和臂比分别为中期的13.93倍、16.54倍、10.44倍和1.54倍,表现出更高FISH信号分辨率。检测到柚粗线期1号染色体着丝粒附近约3.01 Mb的探针信号缺失区。【结论】首次实现柑橘特定全长粗线期染色体的跟踪研究,为深入开展其结构和配对遗传利用的精准研究提供了新方法。
基金the financial support by the National Key R&D Program of China under grant number 2020YFA0710404the National Natural Science Foundation of China under grant number 51871216+6 种基金the KC Wong Education Foundation(GJTD-2020-09)the Liao Ning Revitalization Talents Programthe State Key Laboratory for Modification of Chemical Fibers and Polymer Materials at Donghua Universitythe Opening Project of Jiangsu Province Key Laboratory of High-End Structural Materials under grant number hsm1801the Opening Project of National Key Laboratory of Shock Wave and Detonation Physics under grant number 6142A03203002the Youth Innovation Promotion Association CASsupported by the Multi-University Research Initiative under grant number AFOSR-FA9550-151-0009 from the Air Force Office of Scientific Research
文摘Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials.Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers.The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures.In particular,the double-Bouligand architecture can effectively deflect cracking paths,alleviate strain localization,and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite,representing a successful implementation of the property-optimizing mechanisms in fish scales.The strength of the composites,specifically the effect of their bioinspired architectures,was interpreted based on the adaptation of classical laminate theory.This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.