Four new^(10)Be-^(26)Al isochron burial ages ranging from 4.4 to 2 Ma on ancestral Colorado River deposits in the lower Colorado River corridor(LCRC)help constrain the river’s evolution during the Pliocene and early ...Four new^(10)Be-^(26)Al isochron burial ages ranging from 4.4 to 2 Ma on ancestral Colorado River deposits in the lower Colorado River corridor(LCRC)help constrain the river’s evolution during the Pliocene and early Pleisto-cene.They help fill a gap between previous work that focused on older and younger deposits:Older dated deposits include the 5 Ma Bouse Formation,which records the integration of the Colorado River through a series of preexisting basins to the Gulf of California and the ca.4.5-3.5 Ma Bullhead Alluvium,a 200 to 300 m thick aggregational package that immediately followed integration.The much younger,100-70 ka,Chemehuevi Formation is another major aggrada-tion package mapped throughout the LCRC.The new burial ages on the facies of Santa Fe Railway(4.37±0.71 Ma),boulder conglomerate of Bat Cave Wash(2.12±0.26 and 2.05±0.31 Ma),and the Palo Verde alluvium(3.03±0.26 Ma)partially fill in a 3.5 M.y.gap between the deposition of the Bullhead Alluvium and the Chemeheuvi Formation and document the timescales over which the Colorado River was able to remove the Bullhead aggradational package and initiate newer and smaller aggradational pulses.展开更多
Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response ...Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response to the global climate change, and thus it is important to track and analyze them. One of the ways to monitor these glaciers is by using multispectral satellite imagery (Landsat imagery). In this article, the feasibility of tracking glacial area via Landsat satellites has been discussed and the trend of 13 glaciers in the Colorado Front Range Region has been analyzed from 1993 to 2021. In this period, the total glacial area across 13 glaciers in the Colorado Front Range Region has decreased by 63.6%, and a significant correlation (p-value p < 0.05) found with the annual global average temperature indicates that the retraction of glaciers is likely a response to the global warming.展开更多
This paper describes the spatial and temporal relationship between AVHRR/NDVI (Normalized Difference Vegetation Index) and climatological parameters (temperature and precipitation), which, in some sense, is influenced...This paper describes the spatial and temporal relationship between AVHRR/NDVI (Normalized Difference Vegetation Index) and climatological parameters (temperature and precipitation), which, in some sense, is influenced by topographical factors and land-cover types in Colorado. The correlation coefficients and partial correlation coefficients have been computed pixel by pixel over Colorado in order to analyze the relationship. The temporal variation and correlation of AVHRR/NDVI, temperature and precipitation were analyzed with a sampling method. The study reveals that there exists a close correspondence between monthly NDVI and temperature, which has strong impact from temperature on the changes of NDVI in Colorado. The spatial changes of NDVI are not influenced obviously by the precipitation since these two variables are different from each other in time series in Colorado. The study clearly revealed the spatial variation and its distribution patterns of relationship between NDVI and climatic parameters (temperature and precipitation) in Colorado.展开更多
Colorado potato beetle(CPB),Leptinotarsa decemlineata,is a notorious destructive pest that mainly feeds on the leaves of potato and several other solanaceous plants.CPB is widely recognized for its adaptation to a rem...Colorado potato beetle(CPB),Leptinotarsa decemlineata,is a notorious destructive pest that mainly feeds on the leaves of potato and several other solanaceous plants.CPB is widely recognized for its adaptation to a remarkable variety of host plants and diverse climates,and its high resistance to insecticides and Bacillus thuringiensis toxins.RNA interference(RNAi)is a sequence-specific,endogenous gene silencing mechanism evoked by small RNA molecules that is used as a robust tool for virus and pest control.RNAi has been extensively tested for CPB management by employing various target genes and delivery methods.This article reviews the screening of RNAi target genes,efficient RNAi delivery systems,and factors affecting RNAi efficiency in CPB,which may help understand the mechanisms of RNAi and its application in CPB control strategy.展开更多
The Colorado potato beetle(CPB),Leptinotarsa decemlineata Say,is an infamous invasive species worldwide.It was first found in Xinjiang Uygur Autonomous Region of China in 1993 and spread to Northeast China in 2013.To ...The Colorado potato beetle(CPB),Leptinotarsa decemlineata Say,is an infamous invasive species worldwide.It was first found in Xinjiang Uygur Autonomous Region of China in 1993 and spread to Northeast China in 2013.To better understand the genetic structure and the diffusion path of their populations in China,we used nine polymorphic microsatellite loci to elucidate the genetic diversity,genetic structure and gene flow among nine CPB populations across Xinjiang and Northeast China.The results show that:(1)Two genetically separated clusters were identified by phylogenetic tree,principal coordinate analysis(PCoA)and Bayesian cluster method.Cluster one contained populations from Xinjiang,China.Cluster two contained populations from Northeast China.A genetic differentiation existed between the two clusters.(2)Three populations in Northeast China hold an obvious genetic differentiation according to the phylogenetic tree and PCoA,indicating that multiple introductions may occur in Northeast China.(3)The Altay population in Xinjiang showed a closer genetic relationship with the populations in Northeast China which may be due to the fact that they collectively originated in neighboring Russia.(4)Among all populations,Mulei and Wusu had obvious gene migrations from Tacheng,indicating that the inland populations are most likely to originate from Tacheng,Xinjiang.展开更多
Land cover change from renewable energy development in southern California is receiving increasing attention due to potential impacts on protected area conservation, endangered species, and greenhouse gas emissions. T...Land cover change from renewable energy development in southern California is receiving increasing attention due to potential impacts on protected area conservation, endangered species, and greenhouse gas emissions. This study was designed to quantify and map, for the first time, variations desert vegetation canopy density and related growth rates using 30 consecutive years of Landsat satellite image data across the Lower Colorado Desert. The time-series for mean normalized difference vegetation index (NDVI) values sampled from each of the three major land cover types (shrubland, barren sand dune, and developed urban) showed no significant positive or negative trend in vegetation canopy density. Three periods of significant decrease in NDVI were detected during the drought periods of 1989-1990, 2002-2003, and 2013-2015, indicating that annual precipitation has been the main controller of shrubland canopy growth and green cover. Shrubland canopy cover has been relatively stable in renewable energy development zones since the mid-2000s. NDVI change in the period after nearly all southern California solar energy developments were initiated (post-2010) could be attributed largely to topographic water flow pathways through canyons and desert washes, both in and around all solar energy development zones.展开更多
The CPB （Colorado potato beetle）, Leptinotarsa decemlineata （Say）, is the major insect pest of potato crops in North America, Europe and Asia. Large amounts of chemical insecticides are used to control this insect...The CPB （Colorado potato beetle）, Leptinotarsa decemlineata （Say）, is the major insect pest of potato crops in North America, Europe and Asia. Large amounts of chemical insecticides are used to control this insect pest. Also, the CPB has developed over the years a resistance to most of the registered chemical insecticides, including those that were effective at one time. One of the most promising alternatives to chemical insecticides consists of taking advantage of natural enemies. The use of the stinkbug predator Perillus bioculatus to control the CPB has been successful at small scale. However, this natural enemy is not abundant in the nature and its hand release at large scale is not realistic. To remedy to this problem, predators must be massively released in potato fields using a mechanical distributor. Such a machine has been successfully designed and built at the Department of Soils and Agri-Food Engineering of University Lavak In this distributor, masses of predators are placed in small containers and mixed with a carrier material. In the field, the containers are mechanically opened at different locations, based on a source-point mass release option. These locations are determined in advance following a field monitoring of the populations of CPBs. Field trials proved that the mechanical distributor is reliable and ease of use. Its efficiency in releasing insect predators is high and comparable to that obtained in previous laboratory tests.展开更多
Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is one of the most important insect pests of potato (Solanum tuberosum L.). Because of the high value of potato crops, most growers approach management in a ...Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is one of the most important insect pests of potato (Solanum tuberosum L.). Because of the high value of potato crops, most growers approach management in a similar manner. Chemical control of arthropod pests in potato is the standard pest management practice, and will likely continue to be in the foreseeable future. This heavy reliance on chemical control has led to high levels of insecticide resistance. Strategies that rotate chemistries are critical in order to maintain insecticide efficacy, highlighting the immediate need to evaluate novel chemistries to continue to manage this pest successfully. Working with different populations of L. decemlineata, field and lab experiments were conducted to evaluate the baseline toxicity, ovicidal activity, and field efficacy of the novel insecticide tolfenpyrad to L. decemlineata. Lab assays revealed that tolfenpyrad was toxic to both larvae and adults, and that L. decemlineata treated egg masses had a 0% hatch rate. Potato field plots treated with tolfenpyrad had significantly fewer larvae, less defoliation, and higher tuber yields. These data will provide accurate field rates for proper labeling, a baseline reference for tracking changes in L. decemlineata susceptibility, as well as provide a novel chemistry to aid in resistance management programs.展开更多
Detailed topographic map drainage system and erosional landform evidence such as drainage route orientations, drainage divides, divide crossings (low points on drainage divides), erosional escarpments, and similar fea...Detailed topographic map drainage system and erosional landform evidence such as drainage route orientations, drainage divides, divide crossings (low points on drainage divides), erosional escarpments, and similar features in the east central Colorado Elbert and Lincoln County region are considered as pieces of a complex but solvable drainage history puzzle. A satisfactory solution to date has eluded investigators who have worked from the accepted Cenozoic geology and glacial history paradigm (accepted paradigm) perspective in which climatic and tectonic factors operating over long time periods lead to what might be considered to be a randomly determined regional drainage history. A new and fundamentally different Cenozoic geology and glacial history paradigm (new paradigm) in which immense and prolonged south-oriented continental ice sheet meltwater floods flowed across the Elbert and Lincoln County area which at that time was near the rising rim surrounding a thick continental icesheet created and occupied deep “hole”. Map evidence documents how northeast-oriented Republican River headwaters valleys eroded headward across must have been large southeast-oriented floods probably moving toward what at that time would have been an actively eroding and deep east-oriented Arkansas River valley head and how those massive southeast-oriented floods subsequently lowered the Colorado Piedmont surface before being beheaded and reversed when the deep northeast- and east-oriented South Platte River valley eroded headward to create in an identifiable sequence (from east to west) what are now long north-oriented South Platte River tributaries. New paradigm predicted massive and prolonged south-oriented meltwater floods flowing across what must have been a rising region explains much, if not all of the Elbert and Lincoln County detailed topographic map drainage system and erosional landform evidence.展开更多
In field and laboratory conditions the reproductive potential （survival at different stages of development） of the Colorado potato beetle has been measured, the dependence of the parameters of insects fertility on v...In field and laboratory conditions the reproductive potential （survival at different stages of development） of the Colorado potato beetle has been measured, the dependence of the parameters of insects fertility on varietal features of the feed has been investigated, the food activity of the representatives of insects from four areas of the Southern Urals has been measured, the intensity and time of hypersensitivity reactions on potato leaves has been defined. In laboratory experiments, the level of activity of hydrolytic enzymes in insects and the level of activity of these enzymes inhibitors in the leaves of three potato varieties differing in their resistance to the Colorado potato beetle have been determined. The results show that the insects-representatives of different samples have different food activity in relation to different potato varieties. High mortality rates were revealed at feeding with leaves of potato of the Bashkir variety characterized by a high level of hydrolases inhibitors and relatively rapid development of necrotic reactions after the appearance of eggs laying on the leaves. We suppose that the neerogenetic barrier appearing in the form of necrosis is the major cause of the fetal mortality of insects. The level of the content of inhibitors inactivating larvae digestive enzymes affects the survival of insects at postembryonic stages. The speed of the necrosis emergence, the level of activity of digestive enzymes inhibitors in potato can be considered as criteria for the selection of breeding material for resistance to the Colorado potato beetle.展开更多
Mixed methods were used to gain an understanding of Colorado ski resort employees＇ perceptions of diffusion ofsustainability innovation. Data included eight semi-structured interviews with sustainability managers fro...Mixed methods were used to gain an understanding of Colorado ski resort employees＇ perceptions of diffusion ofsustainability innovation. Data included eight semi-structured interviews with sustainability managers from six skiareas in Colorado and quantitative data from online surveys （N = 264） distributed to employees from five Coloradoski resorts. A sustainability framework coupled with diffusion of innovations theory linked the qualitative andquantitative data. The strongest indicator of corporate sustainability was innovativeness as it relates to leadership.General agreement between the two study groups pertained to drivers and barriers of corporate sustainability fromthe external environment, including competition, customer demand, and government regulations as well as therole of company size and financial structure. While sustainability managers considered innovation characteristicsas important factors affecting corporate sustainability, the second study group （employees not holdingsustainability-related positions） felt those items affected just one dimension of sustainability. Internalcommunication within the resort and the possible lack of understanding of corporate sustainability at allorganizational levels was a concern. Challenges and opportunities for organizational change towards corporatesustainability were noted from the mixed-methods approach.展开更多
The CPB （Colorado potato beetle） is unquestionably the major insect pest of potato crops in North America, Europe, and Asia. The use of chemical insecticides to control this insect pest started in the 1860s. To date...The CPB （Colorado potato beetle） is unquestionably the major insect pest of potato crops in North America, Europe, and Asia. The use of chemical insecticides to control this insect pest started in the 1860s. To date, no registered chemical has been capable of effectively managing this agricultural pest. Moreover, the CPB has developed over the years a resistance to most of the registered chemical insecticides. The biological control through manual release of natural enemies of the CPB has been successful at small scale. However, hand release of these predators at large scale is not realistic. The objective of this study was to investigate the effectiveness of controlling the CPB through mechanical release of predator insects under real conditions in a potato field. Obtained results indicate that the mechanical release of predator insects resulted in a better control of the CPB populations and egg masses than the manual release. The success of this mechanical release of predator insects in potato fields will be highly valuable for the biological control of insect pests in many other row crops such as strawberry, lettuce, etc..展开更多
Vail, a ski area in Colorado established in 1962, has undergone many changes since its inception. How to explain the growth of an ever expanding urban corridor （“Vail Valley”） in the Colorado High Country, with co...Vail, a ski area in Colorado established in 1962, has undergone many changes since its inception. How to explain the growth of an ever expanding urban corridor （“Vail Valley”） in the Colorado High Country, with considerable implications for the social and built-up environment and the surrounding wilderness？ It is argued here that Steinbeck’s writings – as laid out, for instance, in Cannery Row - could offer a strategy to reconstruct the events and developments that transformed the Vail ski resort destination over the past decades. Eight chapters lay out major themes of the Vail Story, from “Vail before Vail” to “Vail after Vail.” Quotations from Steinbeck’s novels and from other writers in the analysis of his works introduce a given theme. The discussion of the beginnings of the ski area and the town, the staging of Vail mega sports events like three world alpine ski championships and the changing directions and policies of the ski corporation result in a narrative closely aligned with the style of Steinbeck’s realistic prose.展开更多
文摘Four new^(10)Be-^(26)Al isochron burial ages ranging from 4.4 to 2 Ma on ancestral Colorado River deposits in the lower Colorado River corridor(LCRC)help constrain the river’s evolution during the Pliocene and early Pleisto-cene.They help fill a gap between previous work that focused on older and younger deposits:Older dated deposits include the 5 Ma Bouse Formation,which records the integration of the Colorado River through a series of preexisting basins to the Gulf of California and the ca.4.5-3.5 Ma Bullhead Alluvium,a 200 to 300 m thick aggregational package that immediately followed integration.The much younger,100-70 ka,Chemehuevi Formation is another major aggrada-tion package mapped throughout the LCRC.The new burial ages on the facies of Santa Fe Railway(4.37±0.71 Ma),boulder conglomerate of Bat Cave Wash(2.12±0.26 and 2.05±0.31 Ma),and the Palo Verde alluvium(3.03±0.26 Ma)partially fill in a 3.5 M.y.gap between the deposition of the Bullhead Alluvium and the Chemeheuvi Formation and document the timescales over which the Colorado River was able to remove the Bullhead aggradational package and initiate newer and smaller aggradational pulses.
文摘Cirque glaciers found on the Colorado Front Range, USA are sensitive to climate change and are important for water supply and the delivery of water downstream. These glaciers are shrinking at a rapid rate in response to the global climate change, and thus it is important to track and analyze them. One of the ways to monitor these glaciers is by using multispectral satellite imagery (Landsat imagery). In this article, the feasibility of tracking glacial area via Landsat satellites has been discussed and the trend of 13 glaciers in the Colorado Front Range Region has been analyzed from 1993 to 2021. In this period, the total glacial area across 13 glaciers in the Colorado Front Range Region has decreased by 63.6%, and a significant correlation (p-value p < 0.05) found with the annual global average temperature indicates that the retraction of glaciers is likely a response to the global warming.
基金Knowledge Innovation Project of CAS No. KZCX1-Y-02
文摘This paper describes the spatial and temporal relationship between AVHRR/NDVI (Normalized Difference Vegetation Index) and climatological parameters (temperature and precipitation), which, in some sense, is influenced by topographical factors and land-cover types in Colorado. The correlation coefficients and partial correlation coefficients have been computed pixel by pixel over Colorado in order to analyze the relationship. The temporal variation and correlation of AVHRR/NDVI, temperature and precipitation were analyzed with a sampling method. The study reveals that there exists a close correspondence between monthly NDVI and temperature, which has strong impact from temperature on the changes of NDVI in Colorado. The spatial changes of NDVI are not influenced obviously by the precipitation since these two variables are different from each other in time series in Colorado. The study clearly revealed the spatial variation and its distribution patterns of relationship between NDVI and climatic parameters (temperature and precipitation) in Colorado.
基金funded by the National Natural Science Foundation of China (31572071)
文摘Colorado potato beetle(CPB),Leptinotarsa decemlineata,is a notorious destructive pest that mainly feeds on the leaves of potato and several other solanaceous plants.CPB is widely recognized for its adaptation to a remarkable variety of host plants and diverse climates,and its high resistance to insecticides and Bacillus thuringiensis toxins.RNA interference(RNAi)is a sequence-specific,endogenous gene silencing mechanism evoked by small RNA molecules that is used as a robust tool for virus and pest control.RNAi has been extensively tested for CPB management by employing various target genes and delivery methods.This article reviews the screening of RNAi target genes,efficient RNAi delivery systems,and factors affecting RNAi efficiency in CPB,which may help understand the mechanisms of RNAi and its application in CPB control strategy.
基金supported by the Monitoring and Control Technology of Alien Species Program of the Ministry of Science and Technology, China (2015BAD08B03)the Strategic Priority Research Program of the Chinese Academy Sciences (CAS) (XDA19050204)+1 种基金the National Key Research and Development Program of China (2018YFD0200802)the National Invasive Biological Prevention and Control Technology Program of the CAS (KFZD-SW-208-07)
文摘The Colorado potato beetle(CPB),Leptinotarsa decemlineata Say,is an infamous invasive species worldwide.It was first found in Xinjiang Uygur Autonomous Region of China in 1993 and spread to Northeast China in 2013.To better understand the genetic structure and the diffusion path of their populations in China,we used nine polymorphic microsatellite loci to elucidate the genetic diversity,genetic structure and gene flow among nine CPB populations across Xinjiang and Northeast China.The results show that:(1)Two genetically separated clusters were identified by phylogenetic tree,principal coordinate analysis(PCoA)and Bayesian cluster method.Cluster one contained populations from Xinjiang,China.Cluster two contained populations from Northeast China.A genetic differentiation existed between the two clusters.(2)Three populations in Northeast China hold an obvious genetic differentiation according to the phylogenetic tree and PCoA,indicating that multiple introductions may occur in Northeast China.(3)The Altay population in Xinjiang showed a closer genetic relationship with the populations in Northeast China which may be due to the fact that they collectively originated in neighboring Russia.(4)Among all populations,Mulei and Wusu had obvious gene migrations from Tacheng,indicating that the inland populations are most likely to originate from Tacheng,Xinjiang.
文摘Land cover change from renewable energy development in southern California is receiving increasing attention due to potential impacts on protected area conservation, endangered species, and greenhouse gas emissions. This study was designed to quantify and map, for the first time, variations desert vegetation canopy density and related growth rates using 30 consecutive years of Landsat satellite image data across the Lower Colorado Desert. The time-series for mean normalized difference vegetation index (NDVI) values sampled from each of the three major land cover types (shrubland, barren sand dune, and developed urban) showed no significant positive or negative trend in vegetation canopy density. Three periods of significant decrease in NDVI were detected during the drought periods of 1989-1990, 2002-2003, and 2013-2015, indicating that annual precipitation has been the main controller of shrubland canopy growth and green cover. Shrubland canopy cover has been relatively stable in renewable energy development zones since the mid-2000s. NDVI change in the period after nearly all southern California solar energy developments were initiated (post-2010) could be attributed largely to topographic water flow pathways through canyons and desert washes, both in and around all solar energy development zones.
文摘The CPB （Colorado potato beetle）, Leptinotarsa decemlineata （Say）, is the major insect pest of potato crops in North America, Europe and Asia. Large amounts of chemical insecticides are used to control this insect pest. Also, the CPB has developed over the years a resistance to most of the registered chemical insecticides, including those that were effective at one time. One of the most promising alternatives to chemical insecticides consists of taking advantage of natural enemies. The use of the stinkbug predator Perillus bioculatus to control the CPB has been successful at small scale. However, this natural enemy is not abundant in the nature and its hand release at large scale is not realistic. To remedy to this problem, predators must be massively released in potato fields using a mechanical distributor. Such a machine has been successfully designed and built at the Department of Soils and Agri-Food Engineering of University Lavak In this distributor, masses of predators are placed in small containers and mixed with a carrier material. In the field, the containers are mechanically opened at different locations, based on a source-point mass release option. These locations are determined in advance following a field monitoring of the populations of CPBs. Field trials proved that the mechanical distributor is reliable and ease of use. Its efficiency in releasing insect predators is high and comparable to that obtained in previous laboratory tests.
文摘Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is one of the most important insect pests of potato (Solanum tuberosum L.). Because of the high value of potato crops, most growers approach management in a similar manner. Chemical control of arthropod pests in potato is the standard pest management practice, and will likely continue to be in the foreseeable future. This heavy reliance on chemical control has led to high levels of insecticide resistance. Strategies that rotate chemistries are critical in order to maintain insecticide efficacy, highlighting the immediate need to evaluate novel chemistries to continue to manage this pest successfully. Working with different populations of L. decemlineata, field and lab experiments were conducted to evaluate the baseline toxicity, ovicidal activity, and field efficacy of the novel insecticide tolfenpyrad to L. decemlineata. Lab assays revealed that tolfenpyrad was toxic to both larvae and adults, and that L. decemlineata treated egg masses had a 0% hatch rate. Potato field plots treated with tolfenpyrad had significantly fewer larvae, less defoliation, and higher tuber yields. These data will provide accurate field rates for proper labeling, a baseline reference for tracking changes in L. decemlineata susceptibility, as well as provide a novel chemistry to aid in resistance management programs.
文摘Detailed topographic map drainage system and erosional landform evidence such as drainage route orientations, drainage divides, divide crossings (low points on drainage divides), erosional escarpments, and similar features in the east central Colorado Elbert and Lincoln County region are considered as pieces of a complex but solvable drainage history puzzle. A satisfactory solution to date has eluded investigators who have worked from the accepted Cenozoic geology and glacial history paradigm (accepted paradigm) perspective in which climatic and tectonic factors operating over long time periods lead to what might be considered to be a randomly determined regional drainage history. A new and fundamentally different Cenozoic geology and glacial history paradigm (new paradigm) in which immense and prolonged south-oriented continental ice sheet meltwater floods flowed across the Elbert and Lincoln County area which at that time was near the rising rim surrounding a thick continental icesheet created and occupied deep “hole”. Map evidence documents how northeast-oriented Republican River headwaters valleys eroded headward across must have been large southeast-oriented floods probably moving toward what at that time would have been an actively eroding and deep east-oriented Arkansas River valley head and how those massive southeast-oriented floods subsequently lowered the Colorado Piedmont surface before being beheaded and reversed when the deep northeast- and east-oriented South Platte River valley eroded headward to create in an identifiable sequence (from east to west) what are now long north-oriented South Platte River tributaries. New paradigm predicted massive and prolonged south-oriented meltwater floods flowing across what must have been a rising region explains much, if not all of the Elbert and Lincoln County detailed topographic map drainage system and erosional landform evidence.
文摘In field and laboratory conditions the reproductive potential （survival at different stages of development） of the Colorado potato beetle has been measured, the dependence of the parameters of insects fertility on varietal features of the feed has been investigated, the food activity of the representatives of insects from four areas of the Southern Urals has been measured, the intensity and time of hypersensitivity reactions on potato leaves has been defined. In laboratory experiments, the level of activity of hydrolytic enzymes in insects and the level of activity of these enzymes inhibitors in the leaves of three potato varieties differing in their resistance to the Colorado potato beetle have been determined. The results show that the insects-representatives of different samples have different food activity in relation to different potato varieties. High mortality rates were revealed at feeding with leaves of potato of the Bashkir variety characterized by a high level of hydrolases inhibitors and relatively rapid development of necrotic reactions after the appearance of eggs laying on the leaves. We suppose that the neerogenetic barrier appearing in the form of necrosis is the major cause of the fetal mortality of insects. The level of the content of inhibitors inactivating larvae digestive enzymes affects the survival of insects at postembryonic stages. The speed of the necrosis emergence, the level of activity of digestive enzymes inhibitors in potato can be considered as criteria for the selection of breeding material for resistance to the Colorado potato beetle.
文摘Mixed methods were used to gain an understanding of Colorado ski resort employees＇ perceptions of diffusion ofsustainability innovation. Data included eight semi-structured interviews with sustainability managers from six skiareas in Colorado and quantitative data from online surveys （N = 264） distributed to employees from five Coloradoski resorts. A sustainability framework coupled with diffusion of innovations theory linked the qualitative andquantitative data. The strongest indicator of corporate sustainability was innovativeness as it relates to leadership.General agreement between the two study groups pertained to drivers and barriers of corporate sustainability fromthe external environment, including competition, customer demand, and government regulations as well as therole of company size and financial structure. While sustainability managers considered innovation characteristicsas important factors affecting corporate sustainability, the second study group （employees not holdingsustainability-related positions） felt those items affected just one dimension of sustainability. Internalcommunication within the resort and the possible lack of understanding of corporate sustainability at allorganizational levels was a concern. Challenges and opportunities for organizational change towards corporatesustainability were noted from the mixed-methods approach.
文摘The CPB （Colorado potato beetle） is unquestionably the major insect pest of potato crops in North America, Europe, and Asia. The use of chemical insecticides to control this insect pest started in the 1860s. To date, no registered chemical has been capable of effectively managing this agricultural pest. Moreover, the CPB has developed over the years a resistance to most of the registered chemical insecticides. The biological control through manual release of natural enemies of the CPB has been successful at small scale. However, hand release of these predators at large scale is not realistic. The objective of this study was to investigate the effectiveness of controlling the CPB through mechanical release of predator insects under real conditions in a potato field. Obtained results indicate that the mechanical release of predator insects resulted in a better control of the CPB populations and egg masses than the manual release. The success of this mechanical release of predator insects in potato fields will be highly valuable for the biological control of insect pests in many other row crops such as strawberry, lettuce, etc..
文摘Vail, a ski area in Colorado established in 1962, has undergone many changes since its inception. How to explain the growth of an ever expanding urban corridor （“Vail Valley”） in the Colorado High Country, with considerable implications for the social and built-up environment and the surrounding wilderness？ It is argued here that Steinbeck’s writings – as laid out, for instance, in Cannery Row - could offer a strategy to reconstruct the events and developments that transformed the Vail ski resort destination over the past decades. Eight chapters lay out major themes of the Vail Story, from “Vail before Vail” to “Vail after Vail.” Quotations from Steinbeck’s novels and from other writers in the analysis of his works introduce a given theme. The discussion of the beginnings of the ski area and the town, the staging of Vail mega sports events like three world alpine ski championships and the changing directions and policies of the ski corporation result in a narrative closely aligned with the style of Steinbeck’s realistic prose.
