Chilling is one of the major abiotic stresses for plants,especially for rice cultivation.Many essential metabolic processes for growth and development are temperature-dependent.In that case,reducing the negative effec...Chilling is one of the major abiotic stresses for plants,especially for rice cultivation.Many essential metabolic processes for growth and development are temperature-dependent.In that case,reducing the negative effects of cold stress using exogenous chemicals is a possible option.Therefore,the current study examined the effects of pre-sowing seed treatment with different chemicals,viz.hydrogen peroxide(H_(2)O_(2)),salicylic acid(SA),calcium chloride(CaCl_(2)),thiourea(TU),and citric acid(CA)on the germination of rice seeds(cv.BRRI dhan28)under chilling environments.Rice seeds were soaked in distilled water(control),10 mM CA,2 mM SA,10 mM CaCl_(2),10 mM H_(2)O_(2),and 10 mM TU solutions for 24 h.After that,seeds were exposed to chilling stress by incubating at 4±1℃ for 8 h,followed by at 25±2℃ for 16 h for 7 days.Exposure to chilling stress significantly reduced thefinal germination percent(13.6%),germination rate index(36.0%),coefficient of the velocity(25.0%),shoot fresh weight(44.4%),and root fresh weight(60.5%).Moreover,chilling induced oxidative damage and reduced the activity of antioxidant enzymes(catalase and ascorbate peroxidase).In contrast,treatments with H_(2)O_(2),SA,CaCl_(2),TU,and CA considerably enhanced germination indices and seedling growth compared to chilling stress condi-tions.The study showed that priming with H_(2)O_(2),SA,CaCl_(2),TU,and CA significantly boosted antioxidant enzyme activities and reduced MDA and H_(2)O_(2) contents in chilling-stressed rice plants,indicating less oxidative stress and improved tolerance.Principal component analysis showed that among these priming agents,H_(2)O_(2),SA,and CA are most effective in chilling stress mitigation.Therefore,using seed-treating chemicals to combat the effect of chilling stress can help rice seedlings grow better in the winter season.展开更多
The paradise thread fish(Polynemus paradiseus)is a commercially and ecologically important euryhaline fish that primarily lives in diversified coastal and estuarine habitats.A comprehensive understanding of the diverg...The paradise thread fish(Polynemus paradiseus)is a commercially and ecologically important euryhaline fish that primarily lives in diversified coastal and estuarine habitats.A comprehensive understanding of the divergence in body shape and discrimination in population parameters related to habitats is crucial for fisheries management and conservation endeavours.To test whether significant morphological differences exist between P.paradiseus populations inhabiting different coastal environments,a total of 366 individuals(198 male and 168 female)were collected from five distant places over three zones-Cox's Bazar(Bakkhali River)and Chattogram(Karnaphuli River)in the southeast coastal regions,Noakhali(lower Meghna River)in the southcentral zone,and Khulna(Shibsa River)and Borguna(Bishkhali River)in the southwest zones adjacent to the Bay of Bengal,Bangladesh in November 2022.The truss networking and geometric morphometric analysis(GMA)indicated variations in body shape among P.paradiseus individuals induced by sexual dimorphism.Wireframe graphs demonstrated that female individuals had wider dorsal-abdominal parts than males.Using the truss networking dataset for five coastal habitats,multivariate analyses revealed two overlapping clusters:southwest(Borguna and Khulna)populations in one cluster,while central(Noakhali)and southeast(Chattogram and Cox's Bazar)populations form separate clusters.The GMA also illustrated that the Khulna-Borguna population was located near the opposite end of the Chattogram-Cox's Bazar population axis,and the Noakhali populations were somewhat in the middle,with a high degree of overlap.Wireframe graphs displayed a significant body shape variations among populations,mainly in the snout shape,the width of the dorsal-abdominal part,the tail shape,and the head shape.The Discriminant Function Analysis revealed that there were pronounced variations in body shape between two populations located in distant regions,while there were minimum variations between two populations located close to each other.This study underscores the effectiveness of landmark-based truss networking and geometric morphometrics in discerning morphological variations across different habitats.These variations likely hold adaptive significance and are critical for informed population management and conservation strategies in the population structure of euryhaline P.paradisus.展开更多
Despite the importance of mud crab species(genus Scylla)in both coastal aquaculture and artisanal fisheries,knowledge of the species diversity and stock structure of mud crab population for their sustainable managemen...Despite the importance of mud crab species(genus Scylla)in both coastal aquaculture and artisanal fisheries,knowledge of the species diversity and stock structure of mud crab population for their sustainable management across the coastal region of Bangladesh remains obscure.Therefore,the present study was conducted to delineate the diversity and stock structure of mud crab species based on the 24 morphometric length measurements and 27 morphometric ratios data collected from the three coastal regions(Chittagong,Cox’s Bazar and Bagerhat)of Bangladesh.Based on the taxonomic keys,majority of the species(about 82.4%)were identified as S.olivacea,while the remaining(about 17.6%)was S.serrata.In consistent to our preliminary analysis,both the univariate proportion and multivariate analysis of the collected morphometric lengths and ratios data also distinctly divided the mud crabs population into two multivariate spaces as S.serrata and S.olivacea.For the further analysis of the stock structure of these two species,data were subjected to the univariate ANOVA,multivariate ANOVA,Canonical Variate Analysis(CVA),and Principal Component Analysis(PCA)according to their collection sites.Scatter plots of CVA scores between CV1 and CV2 and PCA scores between PC1 and PC2 showed that the individuals of both species clearly made clusters into three multivariate spaces with minimum overlaps according to their collection sites.In morphometric traits Linear Discriminant Function Analysis(LDFA),the average percentage of correctly classified(PCC)into the original groups of the S.olivacea and S.serrata was 100%.For stock discrimination,the average PCC into their original groups of collection sites were 100%and 99%for the S.olivacea and S.serrata,respectively.Finally,dendrogram based on the Euclidean distances consistently separated S.olivacea and S.serrata and stock structures similar to other multivariate analyses.In conclusion,our study shows that S.olivacea is the dominant mud crab species and S.serrata is the minor one,and the stock discrimination of each species should be considered in the management and conservation policy of these species along the coastal region of Bangladesh.展开更多
Seaweed is a promising marine macroalgae of the millennium,providing various ecological,social,and economic benefits.At present,seaweed production reached 35.8 million t from farming,accounting for 97%of global seawee...Seaweed is a promising marine macroalgae of the millennium,providing various ecological,social,and economic benefits.At present,seaweed production reached 35.8 million t from farming,accounting for 97%of global seaweed output,with a world market of US$11.8 billion.Seaweeds are an excellent source of nutritious human food because of their low lipid content,high minerals,fibers,polyunsaturated fatty acids,polysaccharides,vitamins,and bioactive compounds.Many seaweed sub-products offer unique properties to develop various functional foods for the food processing industries.In the perspective of climate change mitigation,seaweed farms absorb carbon,serve as a CO_(2)sink and reduce agricultural emissions by providing raw materials for biofuel production and livestock feed.Seaweed farming system also helps in climate change adaptation by absorbing wave energy,safeguarding shorelines,raising the pH of the surrounding water,and oxygenating the waters to minimize the impacts of ocean acidification and hypoxia on a localized scale.Moreover,it contributes substantially to the sustainable development of the economic condition of coastal women by providing livelihood opportunities and ensuring financial solvency.This review paper highlights the significance of seaweed farming in global food and nutritional security,mitigation and adaptation to global climate change,and women empowerment within a single frame.This review paper also outlined the major issues and challenges of seaweed farming for obtaining maximum benefits in these aspects.The main challenges of making seaweed as a staple diet to millions of people include producing suitable species of seaweeds,making seaweed products accessible,affordable,nutritionally balanced,and attractive to the consumers.Various food products must be developed from seaweeds that may be considered equivalent to the foods consumed by humans today.Lack of effective marine spatial planning to avoid user conflicts is vital for expanding the seaweed farming systems to provide aquatic foods and contribute globally for mitigation and adaptation of climate change impacts.Hence,women’s empowerment through seaweed farming is primarily constrained by the lack of technical knowledge and financial resources to establish the coastal farming system.All the information discussed in this paper will help to understand the critical needs for large-scale seaweed farming for climate resilience mariculture,potentials for global food security,and future research on various aspects of seaweed farming and their diverse utilization.展开更多
Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of t...Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of these active nanoscale waveguides are sensitive to the little changes in geometry, external injection/biasing, and doping profiles, and can be crucial in design and manufacturing processes. This paper brings the active silicon waveguide for complete characterization of various distinctive guiding parameters, including perturbation in real and imaginary refractive index, mode loss, group velocity dispersion, and bending loss, which can be instrumental in developing optimal design specifications for various application-centric active silicon waveguides.展开更多
文摘Chilling is one of the major abiotic stresses for plants,especially for rice cultivation.Many essential metabolic processes for growth and development are temperature-dependent.In that case,reducing the negative effects of cold stress using exogenous chemicals is a possible option.Therefore,the current study examined the effects of pre-sowing seed treatment with different chemicals,viz.hydrogen peroxide(H_(2)O_(2)),salicylic acid(SA),calcium chloride(CaCl_(2)),thiourea(TU),and citric acid(CA)on the germination of rice seeds(cv.BRRI dhan28)under chilling environments.Rice seeds were soaked in distilled water(control),10 mM CA,2 mM SA,10 mM CaCl_(2),10 mM H_(2)O_(2),and 10 mM TU solutions for 24 h.After that,seeds were exposed to chilling stress by incubating at 4±1℃ for 8 h,followed by at 25±2℃ for 16 h for 7 days.Exposure to chilling stress significantly reduced thefinal germination percent(13.6%),germination rate index(36.0%),coefficient of the velocity(25.0%),shoot fresh weight(44.4%),and root fresh weight(60.5%).Moreover,chilling induced oxidative damage and reduced the activity of antioxidant enzymes(catalase and ascorbate peroxidase).In contrast,treatments with H_(2)O_(2),SA,CaCl_(2),TU,and CA considerably enhanced germination indices and seedling growth compared to chilling stress condi-tions.The study showed that priming with H_(2)O_(2),SA,CaCl_(2),TU,and CA significantly boosted antioxidant enzyme activities and reduced MDA and H_(2)O_(2) contents in chilling-stressed rice plants,indicating less oxidative stress and improved tolerance.Principal component analysis showed that among these priming agents,H_(2)O_(2),SA,and CA are most effective in chilling stress mitigation.Therefore,using seed-treating chemicals to combat the effect of chilling stress can help rice seedlings grow better in the winter season.
基金funded by the Chattogram Veterinary and Animal Sciences University(CVASU)research budget and the University Grants Commission(UGC)of Bangladesh(Grant No CVASU 27).
文摘The paradise thread fish(Polynemus paradiseus)is a commercially and ecologically important euryhaline fish that primarily lives in diversified coastal and estuarine habitats.A comprehensive understanding of the divergence in body shape and discrimination in population parameters related to habitats is crucial for fisheries management and conservation endeavours.To test whether significant morphological differences exist between P.paradiseus populations inhabiting different coastal environments,a total of 366 individuals(198 male and 168 female)were collected from five distant places over three zones-Cox's Bazar(Bakkhali River)and Chattogram(Karnaphuli River)in the southeast coastal regions,Noakhali(lower Meghna River)in the southcentral zone,and Khulna(Shibsa River)and Borguna(Bishkhali River)in the southwest zones adjacent to the Bay of Bengal,Bangladesh in November 2022.The truss networking and geometric morphometric analysis(GMA)indicated variations in body shape among P.paradiseus individuals induced by sexual dimorphism.Wireframe graphs demonstrated that female individuals had wider dorsal-abdominal parts than males.Using the truss networking dataset for five coastal habitats,multivariate analyses revealed two overlapping clusters:southwest(Borguna and Khulna)populations in one cluster,while central(Noakhali)and southeast(Chattogram and Cox's Bazar)populations form separate clusters.The GMA also illustrated that the Khulna-Borguna population was located near the opposite end of the Chattogram-Cox's Bazar population axis,and the Noakhali populations were somewhat in the middle,with a high degree of overlap.Wireframe graphs displayed a significant body shape variations among populations,mainly in the snout shape,the width of the dorsal-abdominal part,the tail shape,and the head shape.The Discriminant Function Analysis revealed that there were pronounced variations in body shape between two populations located in distant regions,while there were minimum variations between two populations located close to each other.This study underscores the effectiveness of landmark-based truss networking and geometric morphometrics in discerning morphological variations across different habitats.These variations likely hold adaptive significance and are critical for informed population management and conservation strategies in the population structure of euryhaline P.paradisus.
基金This study was funded by the Chittagong Veterinary and Animal Sciences University(CVASU)research budget and University Grants Commission(UGC)of Bangladesh.Supports from the masters’students and supporting staffs of the Department of Marine Bioresource Science(MBS)of CVASU are gratefully appreciated.
文摘Despite the importance of mud crab species(genus Scylla)in both coastal aquaculture and artisanal fisheries,knowledge of the species diversity and stock structure of mud crab population for their sustainable management across the coastal region of Bangladesh remains obscure.Therefore,the present study was conducted to delineate the diversity and stock structure of mud crab species based on the 24 morphometric length measurements and 27 morphometric ratios data collected from the three coastal regions(Chittagong,Cox’s Bazar and Bagerhat)of Bangladesh.Based on the taxonomic keys,majority of the species(about 82.4%)were identified as S.olivacea,while the remaining(about 17.6%)was S.serrata.In consistent to our preliminary analysis,both the univariate proportion and multivariate analysis of the collected morphometric lengths and ratios data also distinctly divided the mud crabs population into two multivariate spaces as S.serrata and S.olivacea.For the further analysis of the stock structure of these two species,data were subjected to the univariate ANOVA,multivariate ANOVA,Canonical Variate Analysis(CVA),and Principal Component Analysis(PCA)according to their collection sites.Scatter plots of CVA scores between CV1 and CV2 and PCA scores between PC1 and PC2 showed that the individuals of both species clearly made clusters into three multivariate spaces with minimum overlaps according to their collection sites.In morphometric traits Linear Discriminant Function Analysis(LDFA),the average percentage of correctly classified(PCC)into the original groups of the S.olivacea and S.serrata was 100%.For stock discrimination,the average PCC into their original groups of collection sites were 100%and 99%for the S.olivacea and S.serrata,respectively.Finally,dendrogram based on the Euclidean distances consistently separated S.olivacea and S.serrata and stock structures similar to other multivariate analyses.In conclusion,our study shows that S.olivacea is the dominant mud crab species and S.serrata is the minor one,and the stock discrimination of each species should be considered in the management and conservation policy of these species along the coastal region of Bangladesh.
基金This research is part of the CGIAR Research Program on Fish Agri-Food Systems(FISH)and is being carried out as a sub-project of the Enhanced Coastal Fisheries in Bangladesh(ECOFISH-BD)activity(PLA 12825),which is funded by the United States Agency for International Development(USAID)and is being carried out in collaboration with WorldFish,Bangladesh,and South Asia Office,and the Department of Fisheries(DOF),Bangladesh.
文摘Seaweed is a promising marine macroalgae of the millennium,providing various ecological,social,and economic benefits.At present,seaweed production reached 35.8 million t from farming,accounting for 97%of global seaweed output,with a world market of US$11.8 billion.Seaweeds are an excellent source of nutritious human food because of their low lipid content,high minerals,fibers,polyunsaturated fatty acids,polysaccharides,vitamins,and bioactive compounds.Many seaweed sub-products offer unique properties to develop various functional foods for the food processing industries.In the perspective of climate change mitigation,seaweed farms absorb carbon,serve as a CO_(2)sink and reduce agricultural emissions by providing raw materials for biofuel production and livestock feed.Seaweed farming system also helps in climate change adaptation by absorbing wave energy,safeguarding shorelines,raising the pH of the surrounding water,and oxygenating the waters to minimize the impacts of ocean acidification and hypoxia on a localized scale.Moreover,it contributes substantially to the sustainable development of the economic condition of coastal women by providing livelihood opportunities and ensuring financial solvency.This review paper highlights the significance of seaweed farming in global food and nutritional security,mitigation and adaptation to global climate change,and women empowerment within a single frame.This review paper also outlined the major issues and challenges of seaweed farming for obtaining maximum benefits in these aspects.The main challenges of making seaweed as a staple diet to millions of people include producing suitable species of seaweeds,making seaweed products accessible,affordable,nutritionally balanced,and attractive to the consumers.Various food products must be developed from seaweeds that may be considered equivalent to the foods consumed by humans today.Lack of effective marine spatial planning to avoid user conflicts is vital for expanding the seaweed farming systems to provide aquatic foods and contribute globally for mitigation and adaptation of climate change impacts.Hence,women’s empowerment through seaweed farming is primarily constrained by the lack of technical knowledge and financial resources to establish the coastal farming system.All the information discussed in this paper will help to understand the critical needs for large-scale seaweed farming for climate resilience mariculture,potentials for global food security,and future research on various aspects of seaweed farming and their diverse utilization.
文摘Changes in refractive index and the corresponding changes in the characteristics of an optical waveguide in enabling propagation of light are the basis for many modern silicon photonic devices. Optical properties of these active nanoscale waveguides are sensitive to the little changes in geometry, external injection/biasing, and doping profiles, and can be crucial in design and manufacturing processes. This paper brings the active silicon waveguide for complete characterization of various distinctive guiding parameters, including perturbation in real and imaginary refractive index, mode loss, group velocity dispersion, and bending loss, which can be instrumental in developing optimal design specifications for various application-centric active silicon waveguides.
