The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and...The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.展开更多
Irrigation of fish farms with agricultural drainage water may affect cultured fish species. So, the present study utilizes antioxidants supplemented diet to overcome deterioration of drainage water and its negative ef...Irrigation of fish farms with agricultural drainage water may affect cultured fish species. So, the present study utilizes antioxidants supplemented diet to overcome deterioration of drainage water and its negative effect on fish. The studied groups are fish cultured in dechlorinated tap water as control group or drainage water and fed commercial basal diet. While, the other studied groups represented by Oreochromis niloticus fish cultured in drainage water and fed either commercial diet supplemented with vitamin C (5 g/kg diet) or fennel (5 g/kg diet) for 12 weeks. Results of the water physico-chemical parameters of all studied treatments revealed deterioration of the drainage water with a decrease in dissolved oxygen and an increase in pH, total hardness, total alkalinity, salinity, ammonia, nitrite and heavy metals (Cu, Pb and Cd) with significant differences (P ≤ 0.01) in comparison to that of the control dechlorinated tap water group. Data clarified also that Oreochromis niloticus cultured in drainage water showed a decrease in growth rate accompanied by deterioration of fish meat quality. However, fish reared in the same drainage water for the same exposure period and fed vitamin C or fennel supplemented basal diet (5 g/kg diet) recorded values of the studied parameters more or less similar to that of control group fish. Data of the present study, empowered aquaculturist to supplement fish rations with fennel or vitamin C as antioxidants to improve fish growth rate, meat quality as well as protect fish against heavy metals toxicity that could threat Human Being.展开更多
Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. Common measures of lipid quality include moisture, ...Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. Common measures of lipid quality include moisture, insolubles,and unsaponifiables(MIU), titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances(TBARS), and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same source.Furthermore, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a metabolic oxidative challenge.展开更多
The Baiyunpu deposit lies in the southwest plunging Dachengshan anticline in central Hunan, which is a large Pb-Zn polymetallic deposit. The orebodies were surrounded by the Qiziqiao Formation limestone in the Middle ...The Baiyunpu deposit lies in the southwest plunging Dachengshan anticline in central Hunan, which is a large Pb-Zn polymetallic deposit. The orebodies were surrounded by the Qiziqiao Formation limestone in the Middle Devonian, and its geological occurrence is consistent with the wall rocks. A large number of spheroidal pyrite aggregates are found unevenly distributed in the ores. The spheroidal aggregates are made up of kernels and concentric rings. The kernels are composed of approximately epigranular pyrite nanocrystals, while the rings are composed of accumulated pyrite microcrystals growing along the radial direction. The spheroidal pyrite aggregate and its outer zones can be divided into five areas(A–E). The results of electron probe micro analysis(EPMA) show that from the zone A1 to B, Co/Ni 〈1, the sum of Co and Ni is 0.08%–0.26%, S/Fe increases from 2.06 to 2.15. While from the zone C to E, Ni cannot be detected and S/Fe decreases from 2.22 to 2.08. Powder X-ray diffraction(XRD) analysis in the micro zone shows obvious crystalline characteristics in the aggregates. Moving from the inside outwards, the maximum diffraction peak intensity of the(111) and(220) crystal planes of pyrite increases, and the crystallinity improves. The degree of change in the(111) plane is the most prominent. Considering the theory of crystal growth along with the geologic features of the depositional environment where the spheroidal pyrite aggregates developed, we confirm that the spheroidal aggregates are the result of nano-micro crystalline gathering and growth occurring by the following sequence of processes:nano-crystalline nucleation and growth, gathering into a ball, oriented growth of microcrystals, continuous accumulation, and adjustment of grain boundaries. The formation of the spheroidal pyrite aggregates in the late Qiziqiao Formation of the Middle Devonian occurred in a neutral to weak alkaline and reductive sedimentary environment in the normal oxygen-rich shallowwater carbonate platform edge. The variations in the S/Fe ratio and crystallisation characteristics indicate that during pyrite crystal growth, the sulphur fugacity was high locally and rose constantly, the degree of supersaturation decreased locally and the growth environment was stable relatively.展开更多
Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in ord...Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species,we selected the shrub species Caragana korshinskii Kom.in different growth periods as the research plant and conducted in situ root pullout test.The relationships among the maximum pullout resistance,peak root displacement,shrub growth period,and aboveground growth indices(plant height and plant crown breadth)were analyzed,as well as the mechanical process of uprooting.Pullout resistance of 4-15 year-old C.korshinskii ranged from 2.49(±0.25)to 14.71(±4.96)kN,and the peak displacement ranged from 11.77(±8.61)to 26.50(±16.09)cm.The maximum pullout resistance and the peak displacement of roots increased as a power function(R^(2)=0.9038)and a linear function(R^(2)=0.8242)with increasing age,respectively.The maximum pullout resistance and the peak displacement increased with increasing plant height;however,this relationship was not significant.The maximum pullout resistance increased exponentially(R^(2)=0.5522)as the crown breadth increased.There was no significant relationship between the peak displacement and crown breadth.The pullout resistance and displacement curve were divided into three stages:the initial nonlinear growth,linear growth,and nonlinear stages.Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces:the synchronous breakage mode and the periderm preferential breakage mode.These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau,China.展开更多
Poplar leaf defoliator, Clostera fulgurita (Walker) larvae were reared on three Populus deltoides clones (PL1, PL5 and PL7) in the laboratory. The nutritional indices were computed for working out the relationship...Poplar leaf defoliator, Clostera fulgurita (Walker) larvae were reared on three Populus deltoides clones (PL1, PL5 and PL7) in the laboratory. The nutritional indices were computed for working out the relationship between food consumption and growth rate of 3rd, 4th and 5th instar larvae on three clones. The result showed that the consumption index (CI), approximate digestibility (AD), growth rate (GR), relative growth rate (RGR) and efficiency of conversion of ingested food (ECI) decreased with the increase in the age of the larvae. Efficiency of conversion of digested food (ECD) increased with increase in age of the larvae. GR and RGR varied significantly, indicating that larval development was enhanced on PL1 as compared to PL5 & PL7. The values of AD, ECI and ECD were not affected by the different clones. Feeding and growth indices could be useful to define a defoliation prediction model.展开更多
With rapid urban expansion across Tanzania,there is a need to institute steps to address factors and forms as well as impacts and challenges associated with the observed trend.This study’s aim is to use spatial urban...With rapid urban expansion across Tanzania,there is a need to institute steps to address factors and forms as well as impacts and challenges associated with the observed trend.This study’s aim is to use spatial urban landscape indices to analyze the spatial changes in urban forms,patterns,and rates across 11 urban centers in Tanzania over a 30-year study period(1990–2020).During the past three decades,urban lands of 11 cities and town in Tanzania have grown by a total of 480 km2.Leapfrog growth was found as the most dominant form of urban expansion in Tanzania while Dodoma,the capital city of Tanzania,had the highest rate of urban expansion when compared to all other individual cities.The most robust and significant interaction of the AWMLEI and MLEI was found in Kigoma,Arusha,Mtwara,Mafinga,and Tunduma cities.In contrast,Mbeya agricultural city,Arusha the tourist city,Tabora,and Geita Lake zone areas did show their own peculiarities revealing an interesting spatial temporal variation in rate and form of expansion.The outcome of this study reveals that the influence and management of economic and socio-cultural opportunities will be an effective tool for the determination of the rapidly expanding cities and towns of Tanzania.展开更多
Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicator...Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicators are normal,but various types of risk faced by the operation was展开更多
Feeding experiments using three strains ofentomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea were conducted with newly moulted 3rd-5th instar Ocinara varians Walker larvae in the...Feeding experiments using three strains ofentomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea were conducted with newly moulted 3rd-5th instar Ocinara varians Walker larvae in the laboratory. The mortality of larvae immersed individually in spore suspension (1 × 10^7 spores/mL) of all the strains was 〉 80% except 5th instar larvae treated with M. anisopliae which transformed into pupae, but did not result in adult emergence. The growth (total body mass), consumption, relative consumption rate and relative growth rate, were reduced at all three larval stages, while developmental time was extended in infected larvae with concurrent significant increase in approximate digestibility in infected larvae. Conversion of digested food (ECD) and ingested food (ECI) values declined in infected larvae as compared to the healthy larvae (control). The 5th instar larvae treated with M. anisopliae showed higher ECD and ECI values than control. Based on mortality and growth inhibition it can be suggested that all the studied fungal strains have a high potential for biocontrol and could be developed into biocontrol agents against O. varians.展开更多
文摘The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.
文摘Irrigation of fish farms with agricultural drainage water may affect cultured fish species. So, the present study utilizes antioxidants supplemented diet to overcome deterioration of drainage water and its negative effect on fish. The studied groups are fish cultured in dechlorinated tap water as control group or drainage water and fed commercial basal diet. While, the other studied groups represented by Oreochromis niloticus fish cultured in drainage water and fed either commercial diet supplemented with vitamin C (5 g/kg diet) or fennel (5 g/kg diet) for 12 weeks. Results of the water physico-chemical parameters of all studied treatments revealed deterioration of the drainage water with a decrease in dissolved oxygen and an increase in pH, total hardness, total alkalinity, salinity, ammonia, nitrite and heavy metals (Cu, Pb and Cd) with significant differences (P ≤ 0.01) in comparison to that of the control dechlorinated tap water group. Data clarified also that Oreochromis niloticus cultured in drainage water showed a decrease in growth rate accompanied by deterioration of fish meat quality. However, fish reared in the same drainage water for the same exposure period and fed vitamin C or fennel supplemented basal diet (5 g/kg diet) recorded values of the studied parameters more or less similar to that of control group fish. Data of the present study, empowered aquaculturist to supplement fish rations with fennel or vitamin C as antioxidants to improve fish growth rate, meat quality as well as protect fish against heavy metals toxicity that could threat Human Being.
文摘Feed fats and oils provide significant amounts of energy to swine diets, but there is large variation in composition,quality, feeding value, and price among sources. Common measures of lipid quality include moisture, insolubles,and unsaponifiables(MIU), titer, and free fatty acid content, but provide limited information regarding their feeding value. Lipid peroxidation is an important quality factor related to animal growth performance and health, but maximum tolerable limits in various lipids have not been established. Several indicative assays can be used to detect the presence of various peroxidation compounds, but due to the complexity and numerous compounds produced and degraded during peroxidation process, no single method can adequately determine the extent of peroxidation. Until further information is available, using a combination of peroxide value, thiobarbituric acid reactive substances(TBARS), and anisidine value appear to provide a reasonable assessment of the extent of peroxidation in a lipid at a reasonable cost. However, fatty acid composition of the lipid being evaluated should be considered when selecting specific assays. Predictive tests can also be used to estimate the stability or susceptibility of lipids to peroxidation and include active oxygen method, oil stability index, and oxygen bomb method. A review of 16 published studies with pigs has shown an average decrease of 11.4% in growth rate, 8.8% feed intake fed isocaloric diets containing peroxidized lipids compared to diets containing unperoxidized lipids of the same source.Furthermore, serum vitamin E content was generally reduced and serum TBARS content was increased when peroxidized lipids were fed in these studies, suggesting that feeding peroxidized lipids negatively affects metabolic oxidative status of pigs. However, it is unclear if antioxidants are useful additions to lipids to maintain optimal nutritional value, or if their addition to swine diets is beneficial in overcoming a metabolic oxidative challenge.
基金granted by the National Natural Science Foundation of China (Grant No. 41172047, 41272062)the Open Fund of the State Key Laboratory of Ore Deposit Geochemistry (Institute of Geochemistry, Chinese Academy of Sciences, Guiyang) (Grant No. 201308)
文摘The Baiyunpu deposit lies in the southwest plunging Dachengshan anticline in central Hunan, which is a large Pb-Zn polymetallic deposit. The orebodies were surrounded by the Qiziqiao Formation limestone in the Middle Devonian, and its geological occurrence is consistent with the wall rocks. A large number of spheroidal pyrite aggregates are found unevenly distributed in the ores. The spheroidal aggregates are made up of kernels and concentric rings. The kernels are composed of approximately epigranular pyrite nanocrystals, while the rings are composed of accumulated pyrite microcrystals growing along the radial direction. The spheroidal pyrite aggregate and its outer zones can be divided into five areas(A–E). The results of electron probe micro analysis(EPMA) show that from the zone A1 to B, Co/Ni 〈1, the sum of Co and Ni is 0.08%–0.26%, S/Fe increases from 2.06 to 2.15. While from the zone C to E, Ni cannot be detected and S/Fe decreases from 2.22 to 2.08. Powder X-ray diffraction(XRD) analysis in the micro zone shows obvious crystalline characteristics in the aggregates. Moving from the inside outwards, the maximum diffraction peak intensity of the(111) and(220) crystal planes of pyrite increases, and the crystallinity improves. The degree of change in the(111) plane is the most prominent. Considering the theory of crystal growth along with the geologic features of the depositional environment where the spheroidal pyrite aggregates developed, we confirm that the spheroidal aggregates are the result of nano-micro crystalline gathering and growth occurring by the following sequence of processes:nano-crystalline nucleation and growth, gathering into a ball, oriented growth of microcrystals, continuous accumulation, and adjustment of grain boundaries. The formation of the spheroidal pyrite aggregates in the late Qiziqiao Formation of the Middle Devonian occurred in a neutral to weak alkaline and reductive sedimentary environment in the normal oxygen-rich shallowwater carbonate platform edge. The variations in the S/Fe ratio and crystallisation characteristics indicate that during pyrite crystal growth, the sulphur fugacity was high locally and rose constantly, the degree of supersaturation decreased locally and the growth environment was stable relatively.
基金funded by the National Natural Science Foundation of China (42002283, 42062019)the Science and Technology Plan Project of Qinghai Province,China (2022-ZJ-Y08)the Second Tibetan Plateau Scientific Expedition and Research (STEP) Program (2019QZKK0905, 2019QZKK0805)
文摘Roots exert pullout resistance under pullout force,allowing plants to resist uprooting.However,the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear.In this study,in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species,we selected the shrub species Caragana korshinskii Kom.in different growth periods as the research plant and conducted in situ root pullout test.The relationships among the maximum pullout resistance,peak root displacement,shrub growth period,and aboveground growth indices(plant height and plant crown breadth)were analyzed,as well as the mechanical process of uprooting.Pullout resistance of 4-15 year-old C.korshinskii ranged from 2.49(±0.25)to 14.71(±4.96)kN,and the peak displacement ranged from 11.77(±8.61)to 26.50(±16.09)cm.The maximum pullout resistance and the peak displacement of roots increased as a power function(R^(2)=0.9038)and a linear function(R^(2)=0.8242)with increasing age,respectively.The maximum pullout resistance and the peak displacement increased with increasing plant height;however,this relationship was not significant.The maximum pullout resistance increased exponentially(R^(2)=0.5522)as the crown breadth increased.There was no significant relationship between the peak displacement and crown breadth.The pullout resistance and displacement curve were divided into three stages:the initial nonlinear growth,linear growth,and nonlinear stages.Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces:the synchronous breakage mode and the periderm preferential breakage mode.These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau,China.
文摘Poplar leaf defoliator, Clostera fulgurita (Walker) larvae were reared on three Populus deltoides clones (PL1, PL5 and PL7) in the laboratory. The nutritional indices were computed for working out the relationship between food consumption and growth rate of 3rd, 4th and 5th instar larvae on three clones. The result showed that the consumption index (CI), approximate digestibility (AD), growth rate (GR), relative growth rate (RGR) and efficiency of conversion of ingested food (ECI) decreased with the increase in the age of the larvae. Efficiency of conversion of digested food (ECD) increased with increase in age of the larvae. GR and RGR varied significantly, indicating that larval development was enhanced on PL1 as compared to PL5 & PL7. The values of AD, ECI and ECD were not affected by the different clones. Feeding and growth indices could be useful to define a defoliation prediction model.
基金supported by the Sokoine University of Agriculture Research and Innovation Support(SUARIS)2nd Phase special Grant[2022/2024]the Directorate of Postgraduate Studies,Research,Technology Transfer and Consultancy(DPRTC).
文摘With rapid urban expansion across Tanzania,there is a need to institute steps to address factors and forms as well as impacts and challenges associated with the observed trend.This study’s aim is to use spatial urban landscape indices to analyze the spatial changes in urban forms,patterns,and rates across 11 urban centers in Tanzania over a 30-year study period(1990–2020).During the past three decades,urban lands of 11 cities and town in Tanzania have grown by a total of 480 km2.Leapfrog growth was found as the most dominant form of urban expansion in Tanzania while Dodoma,the capital city of Tanzania,had the highest rate of urban expansion when compared to all other individual cities.The most robust and significant interaction of the AWMLEI and MLEI was found in Kigoma,Arusha,Mtwara,Mafinga,and Tunduma cities.In contrast,Mbeya agricultural city,Arusha the tourist city,Tabora,and Geita Lake zone areas did show their own peculiarities revealing an interesting spatial temporal variation in rate and form of expansion.The outcome of this study reveals that the influence and management of economic and socio-cultural opportunities will be an effective tool for the determination of the rapidly expanding cities and towns of Tanzania.
文摘Recently,the China Textile Industry Association held 2011 textile and economic operation analysis meeting.The meeting held that the 2011 overall economic operation of China’s textile industry was stable,the indicators are normal,but various types of risk faced by the operation was
文摘Feeding experiments using three strains ofentomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea were conducted with newly moulted 3rd-5th instar Ocinara varians Walker larvae in the laboratory. The mortality of larvae immersed individually in spore suspension (1 × 10^7 spores/mL) of all the strains was 〉 80% except 5th instar larvae treated with M. anisopliae which transformed into pupae, but did not result in adult emergence. The growth (total body mass), consumption, relative consumption rate and relative growth rate, were reduced at all three larval stages, while developmental time was extended in infected larvae with concurrent significant increase in approximate digestibility in infected larvae. Conversion of digested food (ECD) and ingested food (ECI) values declined in infected larvae as compared to the healthy larvae (control). The 5th instar larvae treated with M. anisopliae showed higher ECD and ECI values than control. Based on mortality and growth inhibition it can be suggested that all the studied fungal strains have a high potential for biocontrol and could be developed into biocontrol agents against O. varians.