A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in t...A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan展开更多
The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that incl...The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that includes recreational and commercial fisheries. Due to river training and diversion structures constructed during the past 80 years, the historic characteristics of the LMR have been drastically altered and have likely influenced fishes and fisheries in the system. One common restoration measure used throughout the LMR has been to "notch" wing-dike structures that close secondary(side) river channels. Dike notching allows year-round flows through secondary channels, which enhances habitat diversity and promotes biological productivity at the ecosystem scale. Although notching is presumed good for LMR fishes and other biota, few studies have examined its effects on fish assemblages. In this study, fish assemblages were sampled at seven LMR secondary channels spanning from river kilometer(rkm) 628(Louisiana-Mississippi, U.S.A.) upstream to rkm 1504(Missouri-Kentucky, U.S.A.). Four secondary channels were termed "permanent"(i.e.,with notched dikes) while three secondary channels were termed "temporary"(i.e., without notched dikes).Fishes were sampled by boat-mounted electrofishing conducted during falling and low stages from1995—1997. Fish assemblages differed between permanent and temporary secondary channels, and varied somewhat between falling and low stages. Gizzard shad(Dorosoma cepedianum), threadfin shad(D. petenense), and white bass(Morone chrysops) demonstrated consistent preferences for low-current conditions associated with temporary secondary channels. Conversely, blue catfish(Ictalurus furcatus), flathead catfish(Pylodictis olivaris), and freshwater drum(Aplodinotus grunniens) were more associated with permanent secondary channels. Future restoration strategies in the LMR should consider dike notching and resultant maintenance of permanent secondary channels in selected river reaches. However, temporary secondary channels also contain unique fish species, and also appear to be important sites of riverine primary production. Restoration strategies should consider a balance of both secondary channel types, which should support the greatest biodiversity for the LMR ecosystem.展开更多
This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry te...This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry techniques to be used.Compared with previous similar designs,the circuits proposed in this paper have advantages such as low dissipation,low output impedance,and simplicity of construction.展开更多
Understanding migratory waterfowl spatiotemporal distributions is important because,in addition to their economic and cultural value,wild waterfowl can be infectious reservoirs of highly pathogenic avian influenza vir...Understanding migratory waterfowl spatiotemporal distributions is important because,in addition to their economic and cultural value,wild waterfowl can be infectious reservoirs of highly pathogenic avian influenza virus(HPAIV).Waterfowl migration has been implicated in regional and intercontinental HPAIV dispersal,and predictive capabilities of where and when HPAIV may be introduced to susceptible spillover hosts would facilitate biosecurity and mitigation efforts.To develop forecasts for HPAIV dispersal,an improved understanding of how individual birds interact with their environment and move on a landscape scale is required.Using an agent-based modeling approach,we integrated individual-scale energetics,species-specific morphology and behavior,and landscape-scale weather and habitat data in a mechanistic stochastic framework to simulate Mallard(Anas platyrhynchos)and Northern Pintail(Anas acuta)annual migration across the Northern Hemisphere.Our model recreated biologically realistic migratory patterns using a first principles approach to waterfowl ecology,behavior,and physiology.Conducting a limited structural sensitivity analysis comparing reduced models to eBird Status and Trends in reference to the full model,we identified density dependence as the main factor influencing spring migration and breeding distributions,and wind as the main factor influencing fall migration and overwintering distributions.We show evidence of weather patterns in Northeast Asia causing significant intercontinental pintail migration to North America.By linking individual energetics to landscapescale processes,we identify key drivers of waterfowl migration while developing a predictive model responsive to daily weather patterns.This model paves the way for future waterfowl migration research predicting HPAIV transmission,climate change impacts,and oil spill effects.展开更多
Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic...Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H^(2)) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.展开更多
The Larry Nassar scandal at Michigan State University is the worst and most widespread case of childhood sex abuse in this nation’s history to date,affecting over 150 young girls and women.This article asks:What were...The Larry Nassar scandal at Michigan State University is the worst and most widespread case of childhood sex abuse in this nation’s history to date,affecting over 150 young girls and women.This article asks:What were the structural and ideological mechanisms,policies,and practices that enabled this widespread abuse over a thirty-year period?Louis Althusser’s Marxist theory of Ideological State Apparatuses(and feminist responses to this theory)is useful in explaining how state-making institutions-media outlets,universities,athletic organizations,and family units-are not only produced and reproduced along class lines,but also with respect to gendered power dynamics.By examining the patriarchal nature of ISAs,one can begin to understand how Larry Nassar was for so long shielded from suspicion and criminal prosecution by the institutions that employed him.展开更多
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars State Education Ministry(2002-2004)and Shaanxi Provincial Foreign Expert Bureau (2003).
文摘A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan
基金Supported by the Financial from the U.S.Army Corps of Engineers-Lower Mississippi Valley Division,Vicksburg,Mississippi,U.S.A.
文摘The lower Mississippi River(LMR) has been heavily modified for multiple human purposes such as navigation, flood control, and bank stabilization. However, the LMR simultaneously supports a diverse fish fauna that includes recreational and commercial fisheries. Due to river training and diversion structures constructed during the past 80 years, the historic characteristics of the LMR have been drastically altered and have likely influenced fishes and fisheries in the system. One common restoration measure used throughout the LMR has been to "notch" wing-dike structures that close secondary(side) river channels. Dike notching allows year-round flows through secondary channels, which enhances habitat diversity and promotes biological productivity at the ecosystem scale. Although notching is presumed good for LMR fishes and other biota, few studies have examined its effects on fish assemblages. In this study, fish assemblages were sampled at seven LMR secondary channels spanning from river kilometer(rkm) 628(Louisiana-Mississippi, U.S.A.) upstream to rkm 1504(Missouri-Kentucky, U.S.A.). Four secondary channels were termed "permanent"(i.e.,with notched dikes) while three secondary channels were termed "temporary"(i.e., without notched dikes).Fishes were sampled by boat-mounted electrofishing conducted during falling and low stages from1995—1997. Fish assemblages differed between permanent and temporary secondary channels, and varied somewhat between falling and low stages. Gizzard shad(Dorosoma cepedianum), threadfin shad(D. petenense), and white bass(Morone chrysops) demonstrated consistent preferences for low-current conditions associated with temporary secondary channels. Conversely, blue catfish(Ictalurus furcatus), flathead catfish(Pylodictis olivaris), and freshwater drum(Aplodinotus grunniens) were more associated with permanent secondary channels. Future restoration strategies in the LMR should consider dike notching and resultant maintenance of permanent secondary channels in selected river reaches. However, temporary secondary channels also contain unique fish species, and also appear to be important sites of riverine primary production. Restoration strategies should consider a balance of both secondary channel types, which should support the greatest biodiversity for the LMR ecosystem.
基金Project supported by the National Natural Science Foundation of China.
文摘This paper presents CMOS circuit designs of a ternary adder and a ternary multiplier,formulated using transmission function theory.Binary carry signals appearing in these designs allow conventional look-ahead carry techniques to be used.Compared with previous similar designs,the circuits proposed in this paper have advantages such as low dissipation,low output impedance,and simplicity of construction.
文摘Understanding migratory waterfowl spatiotemporal distributions is important because,in addition to their economic and cultural value,wild waterfowl can be infectious reservoirs of highly pathogenic avian influenza virus(HPAIV).Waterfowl migration has been implicated in regional and intercontinental HPAIV dispersal,and predictive capabilities of where and when HPAIV may be introduced to susceptible spillover hosts would facilitate biosecurity and mitigation efforts.To develop forecasts for HPAIV dispersal,an improved understanding of how individual birds interact with their environment and move on a landscape scale is required.Using an agent-based modeling approach,we integrated individual-scale energetics,species-specific morphology and behavior,and landscape-scale weather and habitat data in a mechanistic stochastic framework to simulate Mallard(Anas platyrhynchos)and Northern Pintail(Anas acuta)annual migration across the Northern Hemisphere.Our model recreated biologically realistic migratory patterns using a first principles approach to waterfowl ecology,behavior,and physiology.Conducting a limited structural sensitivity analysis comparing reduced models to eBird Status and Trends in reference to the full model,we identified density dependence as the main factor influencing spring migration and breeding distributions,and wind as the main factor influencing fall migration and overwintering distributions.We show evidence of weather patterns in Northeast Asia causing significant intercontinental pintail migration to North America.By linking individual energetics to landscapescale processes,we identify key drivers of waterfowl migration while developing a predictive model responsive to daily weather patterns.This model paves the way for future waterfowl migration research predicting HPAIV transmission,climate change impacts,and oil spill effects.
基金supported by the Specialty Crop Block Grant Program of the U.S. Department of Agriculture's (USDA), Agricultural Marketing Service (AMS) through the California Department of Food and Agriculture (SCB15015)partly also by funding from the California Leafy Greens Research Board and by Oak Ridge Institute for Science and Education (ORISE) Research Participation Program。
文摘Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H^(2)) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.
文摘The Larry Nassar scandal at Michigan State University is the worst and most widespread case of childhood sex abuse in this nation’s history to date,affecting over 150 young girls and women.This article asks:What were the structural and ideological mechanisms,policies,and practices that enabled this widespread abuse over a thirty-year period?Louis Althusser’s Marxist theory of Ideological State Apparatuses(and feminist responses to this theory)is useful in explaining how state-making institutions-media outlets,universities,athletic organizations,and family units-are not only produced and reproduced along class lines,but also with respect to gendered power dynamics.By examining the patriarchal nature of ISAs,one can begin to understand how Larry Nassar was for so long shielded from suspicion and criminal prosecution by the institutions that employed him.
