Effects of dietary supplementation of chitosan-oligosaccharides （COS） on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied....Effects of dietary supplementation of chitosan-oligosaccharides （COS） on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied. Four experimental diets containing 0, 20, 40, or 60 mg/kg COS （COSO, COS20, COS40, and COS60, respectively） were fed to juvenile rainbow trout （initial weight = 5.2 ± 0.3 g） for 8 weeks. By the end of the feeding trial, representative groups of fish from each dietary treatment were challenged with stressor （30 see air exposure） and pathogen exposure （intraperitoneal injection with Aeromonas hydrophila ）. Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout. However, fish fed the COS40 diet demonstrated improved phagocytic activities, respiratory burst activities and decreased serum cortisol level. Additionally, survival following A. hydrophila challenge was significant higher among fish fed the COS-supplemented feeds, although there was no difference based on the level of supplementation. The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds展开更多
The inclusion of PepSoyGen (PSG), a commercially-available fermented soybean meal product, was evaluated with juvenile rainbow trout, Oncorhynchus mykiss in an initial 70-day feeding trial, with a supplemental trial i...The inclusion of PepSoyGen (PSG), a commercially-available fermented soybean meal product, was evaluated with juvenile rainbow trout, Oncorhynchus mykiss in an initial 70-day feeding trial, with a supplemental trial involving a subset of the experimental diets continuing for an additional 40 d. Six diets containing 0%, 10%, 20%, 30%, 40%, or 50% PSG, with the PSG directly replacing fish meal, were used in the first trial. There were no significant differences in weight gain or feed conversion ratio between the fish meal-based control diet and diets containing up to 30% PSG. However, weight gain was significantly reduced and feed conversion ratio significantly increased with the 40% and 50% PSG diets. No health assessment differences were observed in fish receiving any of the diets, and no evidence of gross gut inflammation was evident. There were no significant differences in weight gain or feed conversion ratio among the four dietary treatments ranging from 0% to 30% PSG which were fed for an additional 40 d after the initial 70-d trial (110 days total). Based on these results, juvenile rainbow trout diets can contain up to 30% PSG without any loss of rearing performance, thereby replacing at least 60% of the fish meal.展开更多
A new type of large-displacement actuating materials called RAINBOW (Reduced and Internally Biased Oxide Wafer) ceramics is fabricated by a chemical reduction of PLZT piezoelectric ceramics. It is found that PLZT is e...A new type of large-displacement actuating materials called RAINBOW (Reduced and Internally Biased Oxide Wafer) ceramics is fabricated by a chemical reduction of PLZT piezoelectric ceramics. It is found that PLZT is easily reduced and the thickness of reduced layer has a linear relationship with the reduction time. The optimal conditions for producing RAINBOW samples from PLZT are determined to be 950℃ for 1-1.5 hours. SEM micrograph shows that the RAINBOW ceramics are composed of reduced and unreduced layer obviously. And the reduced layer is transgranularly fractured while the unreduced ceramic is intergranularly fractured. Metallic lead and refractor oxides (PbO, ZrO_2, ZrTiO_4, etc.) are found in the reduced layer by XRD analyses, however, the crystal structure of PLZT is not found. The analysis of the reduction mechanism is in good accordance with experimental data.展开更多
Background:Aquaculture must continue to reduce dependence on fishmeal(FM)and fishoil in feeds to ensure sustainable sector growth.Therefore,the use of novel aquaculture feed ingredients is growing.In this regard,insec...Background:Aquaculture must continue to reduce dependence on fishmeal(FM)and fishoil in feeds to ensure sustainable sector growth.Therefore,the use of novel aquaculture feed ingredients is growing.In this regard,insects can represent a new world of sustainable and protein-rich ingredients for farmed fish feeds.Accordingly,we investigated the effects of full replacement of FM with Tenebrio molitor(TM)larvae meal in the diet of rainbow trout(Oncorhynchus mykiss)on fish gut and skin microbiota.Methods:A feeding trial was conducted with 126 trout of about 80 g mean initial weight that were fed for 22 weeks with two isonitrogenous,isolipidic,and isoenergetic extruded experimental diets.Partially defatted TM meal was included in one of the diets to replace 100%(TM 100)of FM,whereas the other diet(TM 0)was without TM.To analyse the microbial communities,the Illumina MiSeq platform for sequencing of 16S rRNA gene and Qiime pipeline were used to identify bacteria in the gut and skin mucosa,and in the diets.Results:The data showed no major effects of full FM substitution with TM meal on bacterial species richness and diversity in both,gut mucosa-and skin mucus-associated microbiome.Skin microbiome was dominated by phylum Proteobacteria and especially by Gammaproteobacteria class that constituted approximately half of the bacterial taxa found.The two dietary fish groups did not display distinctive features,except for a decrease in the relative abundance of Deefgea genus(family Neisseriaceae)in trout fed with insect meal.The metagenomic analysis of the gut mucosa indicated that Tenericutes was the most abundant phylum,regardless of the diet.Specifically,within this phylum,the Mollicutes,mainly represented by Mycoplasmataceae family,were the dominant class.However,we observed only a weak dietary modulation of intestinal bacterial communities.The only changes due to full FM replacement with TM meal were a decreased number of Proteobacteria and a reduced number of taxa assigned to Ruminococcaceae and Neisseriaceae families.Conc展开更多
Let G={Gi:i∈[n]} be a collection of not necessarily distinct n-vertex graphs with the same vertex set V,where G can be seen as an edge-colored(multi)graph and each Gi is the set of edges with color i.A graph F on V i...Let G={Gi:i∈[n]} be a collection of not necessarily distinct n-vertex graphs with the same vertex set V,where G can be seen as an edge-colored(multi)graph and each Gi is the set of edges with color i.A graph F on V is called rainbow if any two edges of F come from different Gis’.We say that G is rainbow pancyclic if there is a rainbow cycle Cℓof lengthℓin G for each integerℓ2[3,n].In 2020,Joos and Kim proved a rainbow version of Dirac’s theorem:Ifδ(Gi)≥2/n for each i∈[n],then there is a rainbow Hamiltonian cycle in G.In this paper,under the same condition,we show that G is rainbow pancyclic except that n is even and G consists of n copies of Kn/2,n/2.This result supports the famous meta-conjecture posed by Bondy.展开更多
This review explores the recent development of research on rainbow herbicides as chemical weapons and the geographies of chemical warfare in what is now the Socialist Republic of Vietnam. While the use and impacts of ...This review explores the recent development of research on rainbow herbicides as chemical weapons and the geographies of chemical warfare in what is now the Socialist Republic of Vietnam. While the use and impacts of Agent Orange have previously been well documented, the production and extensive application of five other rainbow agents by the United States military has only recently been investigated in detail. What is exceptional about this research of chemical warfare landscapes is that the 23 refereed journal publications in this review were designed, implemented, and published in a unique collective research project by Ken Olson and a Merry Band of Military Retirees. Their groundbreaking research portfolio includes many geographical dimensions and the political ecology of chemical warfare. This includes the extensive exposure of civilians in Vietnam to these chemical agents, exposure of US military personnel in Southeast Asia and Panama, exposure of civilians near the private industrial sites that produced these rainbow agents in North America and the hazardous soil contamination that perseveres at these sites in Vietnam and the US. Given this impressive research depth and global scope, this review explores the unique way this research portfolio was developed by a Merry Band of Retirees through an interview with its leader, Ken Olson. It examines the goals and ethical orientation of these military veterans, the political ecology involved, the creative strategies they utilized to produce this innovative research, and how they changed the way Veterans exposed to chemical warfare agents are treated by the US government.展开更多
Decabromodiphenyl ether （BDE209） is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethe...Decabromodiphenyl ether （BDE209） is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethers （De-BDEs） and methoxylated brominated diphenyl ethers （MeO-BDEs） posed a potential threat to organisms. Many studies had indicated that BDE209 could metabolize quickly in mammals, but lacking in the basic data about the metabolism of BDE209 in fish. In the present study, two replicate treatment groups of rainbow trout （Oncorhynchus rnykiss） were exposed to BDE209 via a single intraperitoneal injection approximately 100 and 500 ng/g, respectively. Muscle, liver and blood samples were collected to analyze the specific metabolites on day 1 and day 28 post injection. The highest concentration of BDE209 was detected in muscle tissues, from 796.1 ng/g wet weight （day 1） to 687.1 ng/g wet weight （day 28） in high dose group, suggesting that BDE209 could accumulate slightly in muscle tissues. However, BDE209 was not detected in the blood for all treatments. Most congeners of De-BDEs were found in muscle and liver tissues, with the highest concentration in the liver. The main De-BDEs were nona-, octa-, hepta- and penta-De-BDEs. A total of seven MeO-BDE metabolites were observed among different fish tissues. Blood had the highest contribution of the MeO-BDE metabolites. Each MeO-BDE congener increased over the 28 days. These results in contrast to other studies suggested possible species-specific differences in metabolic abilities.展开更多
基金Financial support was provided by 11th 5-year National Key Technologies R & D Program Project No.2006BAD12B06,2006BAD12B08
文摘Effects of dietary supplementation of chitosan-oligosaccharides （COS） on the growth performance, immune response, stress resistance, and disease resistance of juvenile rainbow trout Oncorhynchus mykiss were studied. Four experimental diets containing 0, 20, 40, or 60 mg/kg COS （COSO, COS20, COS40, and COS60, respectively） were fed to juvenile rainbow trout （initial weight = 5.2 ± 0.3 g） for 8 weeks. By the end of the feeding trial, representative groups of fish from each dietary treatment were challenged with stressor （30 see air exposure） and pathogen exposure （intraperitoneal injection with Aeromonas hydrophila ）. Results showed that supplementation of COS in diets did not affect production performance and body composition of rainbow trout. However, fish fed the COS40 diet demonstrated improved phagocytic activities, respiratory burst activities and decreased serum cortisol level. Additionally, survival following A. hydrophila challenge was significant higher among fish fed the COS-supplemented feeds, although there was no difference based on the level of supplementation. The present study suggests that COS can be used as an immuno-stimulant in rainbow trout feeds
文摘The inclusion of PepSoyGen (PSG), a commercially-available fermented soybean meal product, was evaluated with juvenile rainbow trout, Oncorhynchus mykiss in an initial 70-day feeding trial, with a supplemental trial involving a subset of the experimental diets continuing for an additional 40 d. Six diets containing 0%, 10%, 20%, 30%, 40%, or 50% PSG, with the PSG directly replacing fish meal, were used in the first trial. There were no significant differences in weight gain or feed conversion ratio between the fish meal-based control diet and diets containing up to 30% PSG. However, weight gain was significantly reduced and feed conversion ratio significantly increased with the 40% and 50% PSG diets. No health assessment differences were observed in fish receiving any of the diets, and no evidence of gross gut inflammation was evident. There were no significant differences in weight gain or feed conversion ratio among the four dietary treatments ranging from 0% to 30% PSG which were fed for an additional 40 d after the initial 70-d trial (110 days total). Based on these results, juvenile rainbow trout diets can contain up to 30% PSG without any loss of rearing performance, thereby replacing at least 60% of the fish meal.
文摘A new type of large-displacement actuating materials called RAINBOW (Reduced and Internally Biased Oxide Wafer) ceramics is fabricated by a chemical reduction of PLZT piezoelectric ceramics. It is found that PLZT is easily reduced and the thickness of reduced layer has a linear relationship with the reduction time. The optimal conditions for producing RAINBOW samples from PLZT are determined to be 950℃ for 1-1.5 hours. SEM micrograph shows that the RAINBOW ceramics are composed of reduced and unreduced layer obviously. And the reduced layer is transgranularly fractured while the unreduced ceramic is intergranularly fractured. Metallic lead and refractor oxides (PbO, ZrO_2, ZrTiO_4, etc.) are found in the reduced layer by XRD analyses, however, the crystal structure of PLZT is not found. The analysis of the reduction mechanism is in good accordance with experimental data.
基金This research was partially funded by AGER,Network Foundation,Project Fine Feed for Fish(4F)Rif.No.2016-01-01This work was also co-funded by the EU Horizon 2020 AquaIMPACT(Genomic and nutritional innovations for genetically superior farmed fish to improve efficiency in European aquaculture),number:818367.
文摘Background:Aquaculture must continue to reduce dependence on fishmeal(FM)and fishoil in feeds to ensure sustainable sector growth.Therefore,the use of novel aquaculture feed ingredients is growing.In this regard,insects can represent a new world of sustainable and protein-rich ingredients for farmed fish feeds.Accordingly,we investigated the effects of full replacement of FM with Tenebrio molitor(TM)larvae meal in the diet of rainbow trout(Oncorhynchus mykiss)on fish gut and skin microbiota.Methods:A feeding trial was conducted with 126 trout of about 80 g mean initial weight that were fed for 22 weeks with two isonitrogenous,isolipidic,and isoenergetic extruded experimental diets.Partially defatted TM meal was included in one of the diets to replace 100%(TM 100)of FM,whereas the other diet(TM 0)was without TM.To analyse the microbial communities,the Illumina MiSeq platform for sequencing of 16S rRNA gene and Qiime pipeline were used to identify bacteria in the gut and skin mucosa,and in the diets.Results:The data showed no major effects of full FM substitution with TM meal on bacterial species richness and diversity in both,gut mucosa-and skin mucus-associated microbiome.Skin microbiome was dominated by phylum Proteobacteria and especially by Gammaproteobacteria class that constituted approximately half of the bacterial taxa found.The two dietary fish groups did not display distinctive features,except for a decrease in the relative abundance of Deefgea genus(family Neisseriaceae)in trout fed with insect meal.The metagenomic analysis of the gut mucosa indicated that Tenericutes was the most abundant phylum,regardless of the diet.Specifically,within this phylum,the Mollicutes,mainly represented by Mycoplasmataceae family,were the dominant class.However,we observed only a weak dietary modulation of intestinal bacterial communities.The only changes due to full FM replacement with TM meal were a decreased number of Proteobacteria and a reduced number of taxa assigned to Ruminococcaceae and Neisseriaceae families.Conc
基金supported by the National Natural Science Foundation of China(No.12131013,No.12161141006 and No.12201375)the Tianjin Research Innovation Project for Postgraduate Students(No.2022BKY039).
文摘Let G={Gi:i∈[n]} be a collection of not necessarily distinct n-vertex graphs with the same vertex set V,where G can be seen as an edge-colored(multi)graph and each Gi is the set of edges with color i.A graph F on V is called rainbow if any two edges of F come from different Gis’.We say that G is rainbow pancyclic if there is a rainbow cycle Cℓof lengthℓin G for each integerℓ2[3,n].In 2020,Joos and Kim proved a rainbow version of Dirac’s theorem:Ifδ(Gi)≥2/n for each i∈[n],then there is a rainbow Hamiltonian cycle in G.In this paper,under the same condition,we show that G is rainbow pancyclic except that n is even and G consists of n copies of Kn/2,n/2.This result supports the famous meta-conjecture posed by Bondy.
文摘This review explores the recent development of research on rainbow herbicides as chemical weapons and the geographies of chemical warfare in what is now the Socialist Republic of Vietnam. While the use and impacts of Agent Orange have previously been well documented, the production and extensive application of five other rainbow agents by the United States military has only recently been investigated in detail. What is exceptional about this research of chemical warfare landscapes is that the 23 refereed journal publications in this review were designed, implemented, and published in a unique collective research project by Ken Olson and a Merry Band of Military Retirees. Their groundbreaking research portfolio includes many geographical dimensions and the political ecology of chemical warfare. This includes the extensive exposure of civilians in Vietnam to these chemical agents, exposure of US military personnel in Southeast Asia and Panama, exposure of civilians near the private industrial sites that produced these rainbow agents in North America and the hazardous soil contamination that perseveres at these sites in Vietnam and the US. Given this impressive research depth and global scope, this review explores the unique way this research portfolio was developed by a Merry Band of Retirees through an interview with its leader, Ken Olson. It examines the goals and ethical orientation of these military veterans, the political ecology involved, the creative strategies they utilized to produce this innovative research, and how they changed the way Veterans exposed to chemical warfare agents are treated by the US government.
基金supported by the National Basic Research Program (973) of China (No. 2009CB421605)the National Natural Science Foundation of China (No.20877089,20737003)
文摘Decabromodiphenyl ether （BDE209） is the primary component in a commonly used flame retardant. Previous studies had proved that BDE209 itself was not toxic, while its metabolites including debrominated diphenyl ethers （De-BDEs） and methoxylated brominated diphenyl ethers （MeO-BDEs） posed a potential threat to organisms. Many studies had indicated that BDE209 could metabolize quickly in mammals, but lacking in the basic data about the metabolism of BDE209 in fish. In the present study, two replicate treatment groups of rainbow trout （Oncorhynchus rnykiss） were exposed to BDE209 via a single intraperitoneal injection approximately 100 and 500 ng/g, respectively. Muscle, liver and blood samples were collected to analyze the specific metabolites on day 1 and day 28 post injection. The highest concentration of BDE209 was detected in muscle tissues, from 796.1 ng/g wet weight （day 1） to 687.1 ng/g wet weight （day 28） in high dose group, suggesting that BDE209 could accumulate slightly in muscle tissues. However, BDE209 was not detected in the blood for all treatments. Most congeners of De-BDEs were found in muscle and liver tissues, with the highest concentration in the liver. The main De-BDEs were nona-, octa-, hepta- and penta-De-BDEs. A total of seven MeO-BDE metabolites were observed among different fish tissues. Blood had the highest contribution of the MeO-BDE metabolites. Each MeO-BDE congener increased over the 28 days. These results in contrast to other studies suggested possible species-specific differences in metabolic abilities.
