THE numbers are ever-changing, said Wilson Fevrin, head of an international humanitarian agency in Yumbe in north Uganda. Fevrin has been working in the area for as tong as the South Sudanese refugees started coming i...THE numbers are ever-changing, said Wilson Fevrin, head of an international humanitarian agency in Yumbe in north Uganda. Fevrin has been working in the area for as tong as the South Sudanese refugees started coming in, fleeing violence back home.展开更多
The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings....The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments (non-vented, vented, and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk (organic mulches), gravel (inorganic mulch) and no mulch). At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass (from samples extracted after two years) were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth.展开更多
Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reach...Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reaches of the Yangtze River became one of the most important tasks of Western Development strategy. This article, taking Zhaotong as an example, studies the functional regionalization of ecological shelter zones. The study supplies a case for functional regionalization of small and medium regions whose main tasks are environment reservation. With the guidance of theories of functional regionalization, and based on the analysis of Zhaotong's natural, ecological and socioeconomic factors, the paper suggests five principles for factors selection. These principles include: (1) reversing order evaluation; (2) selecting main factors; (3) keeping the integrality of administrative regions of towns; and (4) making the products acceptable by local government. To analyze spatial status of selected factors, LUCC data in 2002, 1:50,000 relief maps and town-unit socioeconomic statistical data in 2004 are used. RS and GIS tools are also applied to melt traditional and modern geographical methods. This would be useful to functional regionalization research in mountainous areas. As a conclusion, the leading functional regions of ecological conservation or economic development are suggested, respectively. Zhaotong city is divided into two-level functional regions. The first-level includes three leading functional regions and they will lead developing direction of sub-regions. The second-level includes eight sub-regions, which are policy implemented regions, and will supply guidance to Zhaotong's ecological shelter zones reconstruction.展开更多
Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studi...Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studies have assessed the protective effect of PSP sand fences,especially through field observations.This study analyzes the effects of double-row PSP sand fences on wind and sand resistance using field observations and a computational fluid dynamics(CFD)numerical simulation.The results of field observations showed that the average windproof efficiencies of the first-row and second-row sand fences were 79.8%and 70.8%,respectively.Moreover,the average windproof efficiencies of the numerical simulation behind the first-row and second-row sand fences were 89.8%and 81.1%,respectively.The sand-resistance efficiency of the double-row PSP sand fences was 65.4%.Sand deposition occurred close to the first-row sand fence;however,there was relatively little sand on the leeward side of the second-row sand fence.The length of sand accumulation near PSP sand fences obtained by numerical simulation was basically consistent with that through field observations,indicating that field observations combined with numerical simulation can provide insight into the complex wind-blown sand field over PSP sand fences.This study indicates that the protection efficiency of the double-row PSP sand fences is sufficient for effective control of sand hazards associated with extremely strong wind in the Gobi areas.The output of this work is expected to improve the future application of PSP sand fences.展开更多
Sustainable livelihood theory provides a comprehensive framework for understanding the interactions between livelihoods of peasant households and regional environment change in low-income areas. Based on field survey ...Sustainable livelihood theory provides a comprehensive framework for understanding the interactions between livelihoods of peasant households and regional environment change in low-income areas. Based on field survey and 946 questionnaires from peasant household conducted in the case study area of Zhaotong, Yunnan Province, the paper has analyzed the basic characteristics of the rural livelihoods, including the asset base status, the income-generating activities, the energy consumption pattern, and the fertility behavior, in the upper reaches of the Changjiang (Yangtze) River. The micro-level findings show the conflicts among extensive agricultural development models, rural energy consumption structures heavily relying on biomass and the environment protection. The conversion of cropland to forest and grass program(CCFGP) has exerted an important influence on the livelihoods of the peasant households, but its design has given little considerations to their long-term livelihood sources, which will affect its sustainability to a great extent. From the perspective of sustainable livelihoods framework, the objectives that must be addressed in the ecological shelter construction in the upper reaches of the Changjiang River should include, first, facilitating access of peasant households to credit, technology and public services, second, encouraging the peasant households to adopt agricultural technology with environmental benefits and strengthen resources-conserving investments, and third, paying close attention to the rural energy problems and the long-term livelihood sources of the households with CCFGP. Given the weak asset base and difficulties of livelihood strategies shift, ecological shelter construction in the upper reaches of the Changjiang River will take a long time.展开更多
Carbon monoxide (CO) is an odorless, colorless gas produced by incomplete combustion of carbonbased compounds. Exposure to CO can cause various adverse health effects ranging from headache and fatigue to coma and de...Carbon monoxide (CO) is an odorless, colorless gas produced by incomplete combustion of carbonbased compounds. Exposure to CO can cause various adverse health effects ranging from headache and fatigue to coma and death. Thousands of illnesses and deaths have been documented through CO poisoning surveillance systems and accident investigations each year.展开更多
At the end of 2019,the novel coronavirus infection outbroke in Wuhan,Hubei Province.On Feb.2,2020,Wuhan,as the worst-hit region,began to build“shelter hospital”rapidly to treat patients with mild ilness.The shelter ...At the end of 2019,the novel coronavirus infection outbroke in Wuhan,Hubei Province.On Feb.2,2020,Wuhan,as the worst-hit region,began to build“shelter hospital”rapidly to treat patients with mild ilness.The shelter hospital has multiple functions such as emergency treatment,surgical treatment and clinical test,which can adapt to emergency medical rescue tasks.Based on the characteristics that shelter hospital only treats patients with mild ilness,tests of shelter laboratory,including coronavirus nucleic acid detection,IgM/IgG antibody serology detection,monitoring and auxiliary diagnosis and/or a required blood routine,urine routine,C-reactive protein,calcitonin original,biochemical indicators(liver enzymes,myocardial enzymes,renal function,etc.)and blood coagulation function test etc,were used to provide important basis for the diagnosis and treatment of the disease.In order to ensure laboratory biosafety,it is necessary to first evaluate the harm level of various specimens.In the laboratory biosafety management,the harm level assessment of microorganisms is the core work of biosafety,which is of great significance to guarantee biosafety.As an emergency deployment afcted by the environment,shelter laboratory must possess strong mobility.This paper will explore how to combine the biosafety model of traditional laboratory with the particularity of shelter laboratory to carry out effective work in response to the current epidemic.展开更多
We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Ital...We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Italian Stone Pine(Pinus pinea L.), Lentisk(Pistacia lentiscus L.),and a combination of Italian Stone Pine and Lentisk(organic mulches), gravel(inorganic mulch) and control), and three tree shelter types(non-vented and vented tree shelters, and control) were tested. An increase in the number of internodes occurred under the gravel mulch, while a reduction in survival was found for the lentisk mulch. Tree shelters had no effect on survival, but increased mean height growth and reduced mean diameter growth during the 4 years(excepting a non-significant effect for vented tree shelter at year four). Comparison of the annual shoots and growth units(GU) between sheltered and unsheltered plants according to year of formation revealed two growth phases. In first phase, shoots were totally or partially inside the shelters; mean length of annual shoots and GU were greater for sheltered plants. The second phase was characterized by shoots emerging from shelters; mean length of annual shoots and GU were similar for all plants, with or without tree shelters. Results suggest that the use of tree shelters, particularly vented shelters, could contribute to the improvement of the artificial regeneration of zeen oak.The use of mulching alone or in combination with tree shelters did not improve zeen oak performance in the field.展开更多
The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertificat...The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world's largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process(i.e., on the changing area of sandy land) because desertification is a complex process,that can be affected by vegetation(including vegetation cover and extent of shelter forests) and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions(i.e., evapotranspiration and precipitation)and the area of shelter forests(P / 0.0001), in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests(accounting for 95.3 % of the total increase in shelter forests) on reducing desertification might be that the selected arbor species were not suited to water conditions(low precipitation, high evapotranspiration) prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.展开更多
The earthquake is considered one of the most devastating disasters in any area of the world due to its potentially destructive force.Based on the various earthquake-related parameters,the risk assessment is enabled in...The earthquake is considered one of the most devastating disasters in any area of the world due to its potentially destructive force.Based on the various earthquake-related parameters,the risk assessment is enabled in advance to prevent future earthquake disasters.In this paper,for providing the shelter space demands to reduce the damage level and prevention costs,an earthquake risk assessment approach is proposed for deriving the risk index based on multiple spatial parameters in the gridded map.The proposed assessment approach is comprised of pre-processing,methodologymodel,and data visualization.The risk index model derives the earthquake risk index by multiple spatial parameters including indexes of earthquake,danger,shelter,and building for blocks in the quantitative gridded map.The parameters are provided based onmathematicalmodels and combinedwith the risk index that presents the earthquake risk assessment result for each block.Therefore,the gridding approach is proposed to provide the elements of the risk assessment area that are used in the spatial parameters.The gridded map is developed for the selected area to visualize risk index parameters associated with each risk zone.Based on the derived result of the proposed earthquake risk indexmodel,emergency shelter requirements are provided according to the risk index for each location,which supports safety measures in advance to prevent future earthquake disasters.展开更多
Under extreme loading condition,a shelter will provide a safe place to protect people from injury caused by blast wave and fragments.In order to save resource and reuse waste materi-als,a new design concept for blast ...Under extreme loading condition,a shelter will provide a safe place to protect people from injury caused by blast wave and fragments.In order to save resource and reuse waste materi-als,a new design concept for blast protection shelter was explored.The new construction was composed of I-section steel panel or C-channel steel panel filled with recycled concrete aggregate.The compaction process of the recycled concrete aggregate filled in the steel construction was ex-perimentally investigated.A single storey shelter based on the proposed design concept was nu-merically simulated by using LS-DYNA software.In the 3D numerical model,three walls were de-signed using I-section steel and one wall using C-channel steel,and all of the four walls were filled with recycled concrete aggregate.The penetration analysis was done by using ConWep.Some penetration tests were also carried out by using a gas gun.It is found that the proposed shelter based on the design concept is effective for blast protection.展开更多
The Great Spotted Woodpecker Dendrocopos major (L.), one of the natural predators of Anoplophora glabripennis (Motsch.) (Coleoptera: Cerambycidae), is resident to Wulate Qianqi County of the Inner Mongolia and ...The Great Spotted Woodpecker Dendrocopos major (L.), one of the natural predators of Anoplophora glabripennis (Motsch.) (Coleoptera: Cerambycidae), is resident to Wulate Qianqi County of the Inner Mongolia and widely found in shelter plantations. In August 2005 and 2006, 174 and 153 nest-cavities of Great Spotted Woodpeckers were found respectively in Wulate Qianqi County and 22 breeding nest-cavities were investigated in 2007. The results showed that mostly willow species were selected for nesting by the Great Spotted Woodpecker, but mature poplar trees also could be chosen. Nest cavities were often found with a protuberance above the cavity entrance or with a downward sloping gradient, or both. The selection of the height of the nest-cavity height was not significant. The vertical diameter of the nest-cavity entrance (VDE) and the horizontal diameter of the nest-cavity entrance (HDE) ranged from 5.0 to 5.8 cm. The results also indicated that the compass orientation of more than 60% of nest-cavities were towards the north, northeast and east. This study suggests a convergence of some nest-cavity characteristics of the Great Spotted Woodpecker in shelter plantations and will help us to make artificial nest for conserving the woodpecker and, as well, use the bird for controlling pests.展开更多
Humanity suffers an ever-present threat of crises. In the event of a crisis, the population in affected areas will be in danger and will need to be evacuated to a safer in order to protect their lives. One of the diff...Humanity suffers an ever-present threat of crises. In the event of a crisis, the population in affected areas will be in danger and will need to be evacuated to a safer in order to protect their lives. One of the difficulties in emergency management is quickly and accurately selecting suitably safe areas of refuge. This paper aims to explain an evacuation shelter selection process that uses rough set theory and a geographical information system (GIS). The proposed approach uses rough set theory concepts to classify shelters and selects suitable shelters on the basis of three factors: distance, capacity, and the availability of life requirements. The preparation of data and reporting of results are performed via the GIS environment. The proposed approach was implemented using Masoura,Egypt, as a case study and the re- sults of this implementation are presented.展开更多
The study describes the improvements of the participants in ESP course incorporating Sheltered Instruction Observation Protocol(SIOP) instruction in China. It aims to investigate whether or not it is effective to inco...The study describes the improvements of the participants in ESP course incorporating Sheltered Instruction Observation Protocol(SIOP) instruction in China. It aims to investigate whether or not it is effective to incorporate the sheltered instruction into ESP course and whether or not the participants will be motivated to improve their English skills for professional purposes. Quantitative and qualitative data sources were employed, including English language tests, questionnaires, and interviews.Findings reveal that the sheltered instruction was helpful to ESP course and produced significant achievements in participants' English vocabulary and skills. The most interesting result is that the participants' confidence and interest in learning professional English for future jobs has been improved much.展开更多
Objective:To determine the prevalence of infection with intestinal parasites in 101 dogs in an animal shelter in Veracruz.Mexico,and investigate whether any general characteristics of the dogs were associated with inf...Objective:To determine the prevalence of infection with intestinal parasites in 101 dogs in an animal shelter in Veracruz.Mexico,and investigate whether any general characteristics of the dogs were associated with infections.Methods:Parasitologiesl examination of fecal samples from the dogs was performed by means of centrifuge-flotation using Sheather's sucrose and zinc sulfate flotation media.In addition,hematocrit was determined in each canine blood sample.Results:Intestinal parasites were found in 99(98.0%) of the 101 dogs studied.About five different intestinal parasites were identified:Ancylostoma caninum in 89 dogs(88.1%).Giardia canis in 46(45.5%).Unciiuiria stenocephalia in 43(42.6%).Trichuris vulpis in 19(18.8%)and Strongyloides canis in 16(15.8%).Multivariate analysis showed:I) Giardia infection was associated with young age and mixed breed;2) Ancylostoma was associated with young age and no rabies vaccination:and 3) Strongyloides was associated with no rabies vaccination.Unciiuiria and Trichuris infections were not associated with the variables assessed.Conclusions:A high prevalence of intestinal parasites was found in the dogs studied.This suggests that the environment is highly contaminated with intestinal parasites.Preventive and therapeutic measures should be taken against infection with intestinal parasites in dogs in this region.展开更多
The construction of artificial shelter forests(ASFs)has resulted in substantial ecological,economic,and societal benefits to the Chinese Loess Plateau(CLP).However,the health and benefits of ASFs are being increasingl...The construction of artificial shelter forests(ASFs)has resulted in substantial ecological,economic,and societal benefits to the Chinese Loess Plateau(CLP).However,the health and benefits of ASFs are being increasingly threatened by the formation of low-efficiency artificial shelter forests(LEASFs).In this study,LEASFs are systematically analyzed in terms of their status,formation mechanisms,and developmental obstacles.The key restoration techniques and schemes were summarized to improve the quality and efficiency of LEASFs.LEASFs are formed by relatively complex mechanisms,but they arise mainly due to poor habitat conditions,improper tree species selections,mismatch between stands and habitat,extensive forest management measures,and human interferences.The restoration and improvement of LEASFs are hindered by water deficits,mismatch between stands and habitat,single management purpose,and low efficiency.LEASFs are becoming more complex due to their wide range,the challenges associated with their restoration,and insufficient technological measures for their restoration.The key techniques of the quality and efficiency improvement of LEASFs include basic forest tending methods,near-natural restoration,multifunction-oriented improvement,and systematic restoration.An understanding on the formation mechanisms of LEASFs and a scientific approach toward their restoration are urgently needed and critical for the ecological protection and high-quality development of LEASFs on the CLP.Based on these analyses,we recommend strengthening the monitoring and supervision of LEASFs,considering the bearing capacity of regional water resources,implementing multiple restoration techniques,promoting multifunction-oriented ecological development,and exploring new management concepts to achieve the sustainable development of ASFs on the CLP.展开更多
The structure and dynamics of land resources system in the shelter forest region in the Northeast Plain is discussed according to the remote sensing and statistical information from the typical profiles and spots. For...The structure and dynamics of land resources system in the shelter forest region in the Northeast Plain is discussed according to the remote sensing and statistical information from the typical profiles and spots. For agricultural utilization, the land resources system is made up of five components, i.e. man, land resources, water resources,climatic resources and barren land. The local economy depends heavily upon its land resources, especially farm land. Having been exploited for 50-60 years from the 1930s to 1980s, it has already changed from the reclaiming period into the declining period.There is no waste land to be reclaimed. Facing the increase of population and requirements and the decrease of farmland fertility, proper management of land resources is indispensable if local economic and living level is maintained. It is imperative to make artificial regeneration (highest input) for the land resources and to keep fine circle of thesystem. If only natural regeneration if relied, the system will be changed to vicious circle.展开更多
文摘THE numbers are ever-changing, said Wilson Fevrin, head of an international humanitarian agency in Yumbe in north Uganda. Fevrin has been working in the area for as tong as the South Sudanese refugees started coming in, fleeing violence back home.
基金supported by the laboratory of silvopastoral resources (Silvopastoral Institute-Tabarka)
文摘The need for reforestation in cork oak (Quercus suber L.) areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments (non-vented, vented, and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk (organic mulches), gravel (inorganic mulch) and no mulch). At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass (from samples extracted after two years) were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth.
基金National Natural'Science Foundation of China, No.40401016
文摘Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reaches of the Yangtze River became one of the most important tasks of Western Development strategy. This article, taking Zhaotong as an example, studies the functional regionalization of ecological shelter zones. The study supplies a case for functional regionalization of small and medium regions whose main tasks are environment reservation. With the guidance of theories of functional regionalization, and based on the analysis of Zhaotong's natural, ecological and socioeconomic factors, the paper suggests five principles for factors selection. These principles include: (1) reversing order evaluation; (2) selecting main factors; (3) keeping the integrality of administrative regions of towns; and (4) making the products acceptable by local government. To analyze spatial status of selected factors, LUCC data in 2002, 1:50,000 relief maps and town-unit socioeconomic statistical data in 2004 are used. RS and GIS tools are also applied to melt traditional and modern geographical methods. This would be useful to functional regionalization research in mountainous areas. As a conclusion, the leading functional regions of ecological conservation or economic development are suggested, respectively. Zhaotong city is divided into two-level functional regions. The first-level includes three leading functional regions and they will lead developing direction of sub-regions. The second-level includes eight sub-regions, which are policy implemented regions, and will supply guidance to Zhaotong's ecological shelter zones reconstruction.
基金This research was funded by the Fellowship of the China Postdoctoral Science Foundation(2021M703466)the Basic Research Innovation Group Project of Gansu Province,China(21JR7RA347)the Natural Science Foundation of Gansu Province,China(20JR10RA231).
文摘Sand fences made of punched steel plate(PSP)have recently been applied to control wind-blown sand in desertified and Gobi areas due to their strong wind resistance and convenient in situ construction.However,few studies have assessed the protective effect of PSP sand fences,especially through field observations.This study analyzes the effects of double-row PSP sand fences on wind and sand resistance using field observations and a computational fluid dynamics(CFD)numerical simulation.The results of field observations showed that the average windproof efficiencies of the first-row and second-row sand fences were 79.8%and 70.8%,respectively.Moreover,the average windproof efficiencies of the numerical simulation behind the first-row and second-row sand fences were 89.8%and 81.1%,respectively.The sand-resistance efficiency of the double-row PSP sand fences was 65.4%.Sand deposition occurred close to the first-row sand fence;however,there was relatively little sand on the leeward side of the second-row sand fence.The length of sand accumulation near PSP sand fences obtained by numerical simulation was basically consistent with that through field observations,indicating that field observations combined with numerical simulation can provide insight into the complex wind-blown sand field over PSP sand fences.This study indicates that the protection efficiency of the double-row PSP sand fences is sufficient for effective control of sand hazards associated with extremely strong wind in the Gobi areas.The output of this work is expected to improve the future application of PSP sand fences.
基金Under the auspices of the Fund Project of Ministry of Science and Technology of the People's Republic of China (No.2005BA807B05)
文摘Sustainable livelihood theory provides a comprehensive framework for understanding the interactions between livelihoods of peasant households and regional environment change in low-income areas. Based on field survey and 946 questionnaires from peasant household conducted in the case study area of Zhaotong, Yunnan Province, the paper has analyzed the basic characteristics of the rural livelihoods, including the asset base status, the income-generating activities, the energy consumption pattern, and the fertility behavior, in the upper reaches of the Changjiang (Yangtze) River. The micro-level findings show the conflicts among extensive agricultural development models, rural energy consumption structures heavily relying on biomass and the environment protection. The conversion of cropland to forest and grass program(CCFGP) has exerted an important influence on the livelihoods of the peasant households, but its design has given little considerations to their long-term livelihood sources, which will affect its sustainability to a great extent. From the perspective of sustainable livelihoods framework, the objectives that must be addressed in the ecological shelter construction in the upper reaches of the Changjiang River should include, first, facilitating access of peasant households to credit, technology and public services, second, encouraging the peasant households to adopt agricultural technology with environmental benefits and strengthen resources-conserving investments, and third, paying close attention to the rural energy problems and the long-term livelihood sources of the households with CCFGP. Given the weak asset base and difficulties of livelihood strategies shift, ecological shelter construction in the upper reaches of the Changjiang River will take a long time.
基金supported by the Medicine and Technology Development Plan Project of Shandong Province(2016WS0119)
文摘Carbon monoxide (CO) is an odorless, colorless gas produced by incomplete combustion of carbonbased compounds. Exposure to CO can cause various adverse health effects ranging from headache and fatigue to coma and death. Thousands of illnesses and deaths have been documented through CO poisoning surveillance systems and accident investigations each year.
基金This project was supported by Major Research Projects of Sichuan Health Commission(No.16ZD026).
文摘At the end of 2019,the novel coronavirus infection outbroke in Wuhan,Hubei Province.On Feb.2,2020,Wuhan,as the worst-hit region,began to build“shelter hospital”rapidly to treat patients with mild ilness.The shelter hospital has multiple functions such as emergency treatment,surgical treatment and clinical test,which can adapt to emergency medical rescue tasks.Based on the characteristics that shelter hospital only treats patients with mild ilness,tests of shelter laboratory,including coronavirus nucleic acid detection,IgM/IgG antibody serology detection,monitoring and auxiliary diagnosis and/or a required blood routine,urine routine,C-reactive protein,calcitonin original,biochemical indicators(liver enzymes,myocardial enzymes,renal function,etc.)and blood coagulation function test etc,were used to provide important basis for the diagnosis and treatment of the disease.In order to ensure laboratory biosafety,it is necessary to first evaluate the harm level of various specimens.In the laboratory biosafety management,the harm level assessment of microorganisms is the core work of biosafety,which is of great significance to guarantee biosafety.As an emergency deployment afcted by the environment,shelter laboratory must possess strong mobility.This paper will explore how to combine the biosafety model of traditional laboratory with the particularity of shelter laboratory to carry out effective work in response to the current epidemic.
基金supported by the laboratory of silvopastoral resources(Silvopastoral Institute-Tabarka)
文摘We assessed the effect of mulching and tree shelters on the establishment and early growth of zeen oak(Quercus canariensis Willd.) during the first 4 years after planting in Northwestern Tunisia. Five mulch types(Italian Stone Pine(Pinus pinea L.), Lentisk(Pistacia lentiscus L.),and a combination of Italian Stone Pine and Lentisk(organic mulches), gravel(inorganic mulch) and control), and three tree shelter types(non-vented and vented tree shelters, and control) were tested. An increase in the number of internodes occurred under the gravel mulch, while a reduction in survival was found for the lentisk mulch. Tree shelters had no effect on survival, but increased mean height growth and reduced mean diameter growth during the 4 years(excepting a non-significant effect for vented tree shelter at year four). Comparison of the annual shoots and growth units(GU) between sheltered and unsheltered plants according to year of formation revealed two growth phases. In first phase, shoots were totally or partially inside the shelters; mean length of annual shoots and GU were greater for sheltered plants. The second phase was characterized by shoots emerging from shelters; mean length of annual shoots and GU were similar for all plants, with or without tree shelters. Results suggest that the use of tree shelters, particularly vented shelters, could contribute to the improvement of the artificial regeneration of zeen oak.The use of mulching alone or in combination with tree shelters did not improve zeen oak performance in the field.
基金supported by grants from the National Nature Science Foundation of China(31025007)the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX1-YW-08-02)
文摘The Horqin Sandy Land(HSL), the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective Forest Program, world's largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling desertification.However, there is little evidence to directly link causal effects with desertification process(i.e., on the changing area of sandy land) because desertification is a complex process,that can be affected by vegetation(including vegetation cover and extent of shelter forests) and water factors such as precipitation, surface soil moisture, and evapotranspiration.The objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions(i.e., evapotranspiration and precipitation)and the area of shelter forests(P / 0.0001), in which water conditions and the existence of shelter forests contributed49.7 and 12.8 % to total vegetation cover, respectively. The area of shelter forests increased sharply due to program efforts, but only shrub forests had significant direct effects on reducing the area of desertification categorized as slightly desertified. The reason for the lack of direct effect of increased arbor forests(accounting for 95.3 % of the total increase in shelter forests) on reducing desertification might be that the selected arbor species were not suited to water conditions(low precipitation, high evapotranspiration) prevailing at HSL. The establishment of shelter forests aided control of desertification in the HSL region, but the effect was less than expected. Effective control of desertification in the HSL region or other similar sandy areas will require greater improvements in vegetation cover. In particular,shrub species should be selected for plantation with reference to their potential to survive and reproduce in the harsh climatic and weather conditions typical of desertified areas.
基金This research was supported in part by the Energy Cloud R&D Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT(2019M3F2A1073387)in part by the Basic Science Research Program through the NRF funded by the Ministry of Education(NRF-2019R1I1A1A01062456),Any correspondence related to this paper should be addressed to Dohyeun Kim.
文摘The earthquake is considered one of the most devastating disasters in any area of the world due to its potentially destructive force.Based on the various earthquake-related parameters,the risk assessment is enabled in advance to prevent future earthquake disasters.In this paper,for providing the shelter space demands to reduce the damage level and prevention costs,an earthquake risk assessment approach is proposed for deriving the risk index based on multiple spatial parameters in the gridded map.The proposed assessment approach is comprised of pre-processing,methodologymodel,and data visualization.The risk index model derives the earthquake risk index by multiple spatial parameters including indexes of earthquake,danger,shelter,and building for blocks in the quantitative gridded map.The parameters are provided based onmathematicalmodels and combinedwith the risk index that presents the earthquake risk assessment result for each block.Therefore,the gridding approach is proposed to provide the elements of the risk assessment area that are used in the spatial parameters.The gridded map is developed for the selected area to visualize risk index parameters associated with each risk zone.Based on the derived result of the proposed earthquake risk indexmodel,emergency shelter requirements are provided according to the risk index for each location,which supports safety measures in advance to prevent future earthquake disasters.
文摘Under extreme loading condition,a shelter will provide a safe place to protect people from injury caused by blast wave and fragments.In order to save resource and reuse waste materi-als,a new design concept for blast protection shelter was explored.The new construction was composed of I-section steel panel or C-channel steel panel filled with recycled concrete aggregate.The compaction process of the recycled concrete aggregate filled in the steel construction was ex-perimentally investigated.A single storey shelter based on the proposed design concept was nu-merically simulated by using LS-DYNA software.In the 3D numerical model,three walls were de-signed using I-section steel and one wall using C-channel steel,and all of the four walls were filled with recycled concrete aggregate.The penetration analysis was done by using ConWep.Some penetration tests were also carried out by using a gas gun.It is found that the proposed shelter based on the design concept is effective for blast protection.
文摘The Great Spotted Woodpecker Dendrocopos major (L.), one of the natural predators of Anoplophora glabripennis (Motsch.) (Coleoptera: Cerambycidae), is resident to Wulate Qianqi County of the Inner Mongolia and widely found in shelter plantations. In August 2005 and 2006, 174 and 153 nest-cavities of Great Spotted Woodpeckers were found respectively in Wulate Qianqi County and 22 breeding nest-cavities were investigated in 2007. The results showed that mostly willow species were selected for nesting by the Great Spotted Woodpecker, but mature poplar trees also could be chosen. Nest cavities were often found with a protuberance above the cavity entrance or with a downward sloping gradient, or both. The selection of the height of the nest-cavity height was not significant. The vertical diameter of the nest-cavity entrance (VDE) and the horizontal diameter of the nest-cavity entrance (HDE) ranged from 5.0 to 5.8 cm. The results also indicated that the compass orientation of more than 60% of nest-cavities were towards the north, northeast and east. This study suggests a convergence of some nest-cavity characteristics of the Great Spotted Woodpecker in shelter plantations and will help us to make artificial nest for conserving the woodpecker and, as well, use the bird for controlling pests.
文摘Humanity suffers an ever-present threat of crises. In the event of a crisis, the population in affected areas will be in danger and will need to be evacuated to a safer in order to protect their lives. One of the difficulties in emergency management is quickly and accurately selecting suitably safe areas of refuge. This paper aims to explain an evacuation shelter selection process that uses rough set theory and a geographical information system (GIS). The proposed approach uses rough set theory concepts to classify shelters and selects suitable shelters on the basis of three factors: distance, capacity, and the availability of life requirements. The preparation of data and reporting of results are performed via the GIS environment. The proposed approach was implemented using Masoura,Egypt, as a case study and the re- sults of this implementation are presented.
文摘The study describes the improvements of the participants in ESP course incorporating Sheltered Instruction Observation Protocol(SIOP) instruction in China. It aims to investigate whether or not it is effective to incorporate the sheltered instruction into ESP course and whether or not the participants will be motivated to improve their English skills for professional purposes. Quantitative and qualitative data sources were employed, including English language tests, questionnaires, and interviews.Findings reveal that the sheltered instruction was helpful to ESP course and produced significant achievements in participants' English vocabulary and skills. The most interesting result is that the participants' confidence and interest in learning professional English for future jobs has been improved much.
基金Supported by Universidad Veracruzana and Juarez University of Durango State(Grant No.P4 UV-UJED)
文摘Objective:To determine the prevalence of infection with intestinal parasites in 101 dogs in an animal shelter in Veracruz.Mexico,and investigate whether any general characteristics of the dogs were associated with infections.Methods:Parasitologiesl examination of fecal samples from the dogs was performed by means of centrifuge-flotation using Sheather's sucrose and zinc sulfate flotation media.In addition,hematocrit was determined in each canine blood sample.Results:Intestinal parasites were found in 99(98.0%) of the 101 dogs studied.About five different intestinal parasites were identified:Ancylostoma caninum in 89 dogs(88.1%).Giardia canis in 46(45.5%).Unciiuiria stenocephalia in 43(42.6%).Trichuris vulpis in 19(18.8%)and Strongyloides canis in 16(15.8%).Multivariate analysis showed:I) Giardia infection was associated with young age and mixed breed;2) Ancylostoma was associated with young age and no rabies vaccination:and 3) Strongyloides was associated with no rabies vaccination.Unciiuiria and Trichuris infections were not associated with the variables assessed.Conclusions:A high prevalence of intestinal parasites was found in the dogs studied.This suggests that the environment is highly contaminated with intestinal parasites.Preventive and therapeutic measures should be taken against infection with intestinal parasites in dogs in this region.
基金supported by the Science and Technology Innovation Program of the Shaanxi Academy of Forestry (SXLK2022-02)the National Natural Science Foundation of China (42077452)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA23070201).
文摘The construction of artificial shelter forests(ASFs)has resulted in substantial ecological,economic,and societal benefits to the Chinese Loess Plateau(CLP).However,the health and benefits of ASFs are being increasingly threatened by the formation of low-efficiency artificial shelter forests(LEASFs).In this study,LEASFs are systematically analyzed in terms of their status,formation mechanisms,and developmental obstacles.The key restoration techniques and schemes were summarized to improve the quality and efficiency of LEASFs.LEASFs are formed by relatively complex mechanisms,but they arise mainly due to poor habitat conditions,improper tree species selections,mismatch between stands and habitat,extensive forest management measures,and human interferences.The restoration and improvement of LEASFs are hindered by water deficits,mismatch between stands and habitat,single management purpose,and low efficiency.LEASFs are becoming more complex due to their wide range,the challenges associated with their restoration,and insufficient technological measures for their restoration.The key techniques of the quality and efficiency improvement of LEASFs include basic forest tending methods,near-natural restoration,multifunction-oriented improvement,and systematic restoration.An understanding on the formation mechanisms of LEASFs and a scientific approach toward their restoration are urgently needed and critical for the ecological protection and high-quality development of LEASFs on the CLP.Based on these analyses,we recommend strengthening the monitoring and supervision of LEASFs,considering the bearing capacity of regional water resources,implementing multiple restoration techniques,promoting multifunction-oriented ecological development,and exploring new management concepts to achieve the sustainable development of ASFs on the CLP.
文摘The structure and dynamics of land resources system in the shelter forest region in the Northeast Plain is discussed according to the remote sensing and statistical information from the typical profiles and spots. For agricultural utilization, the land resources system is made up of five components, i.e. man, land resources, water resources,climatic resources and barren land. The local economy depends heavily upon its land resources, especially farm land. Having been exploited for 50-60 years from the 1930s to 1980s, it has already changed from the reclaiming period into the declining period.There is no waste land to be reclaimed. Facing the increase of population and requirements and the decrease of farmland fertility, proper management of land resources is indispensable if local economic and living level is maintained. It is imperative to make artificial regeneration (highest input) for the land resources and to keep fine circle of thesystem. If only natural regeneration if relied, the system will be changed to vicious circle.