Regardless of the excellent properties of glass ionomer cements,their poor mechanical properties limit their applications to non-load bearing areas.This study aimed to investigate the effect of incorporated short,chop...Regardless of the excellent properties of glass ionomer cements,their poor mechanical properties limit their applications to non-load bearing areas.This study aimed to investigate the effect of incorporated short,chopped and randomly distributed flax fibers(0,0.5,1,2.5,5 and 25 wt%) on setting reaction kinetics,and mechanical and morphological properties of glass ionomer cements.Addition of flax fibers did not significantly affect the setting reaction extent.According to their content,flax fibers increased the compressive(from 148 to 250 MPa) and flexure strength(from 20 to 42 MPa).They also changed the brittle behavior of glass ionomer cements to a plastic one.They significantly reduced the compressive(from 3 to 1.3 GPa) and flexure modulus(from 19 to 14 GPa).Accordingly,flax fiber-modified glass ionomer cements could be potentially used in high-stress bearing areas.展开更多
Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion ...Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.展开更多
The Southwest Australian Floristic Region(SWAFR) is a global biodiversity hotspot with high plant diversity and endemism and a broad range of threatening processes. An outcome of this is a high proportion of rare and ...The Southwest Australian Floristic Region(SWAFR) is a global biodiversity hotspot with high plant diversity and endemism and a broad range of threatening processes. An outcome of this is a high proportion of rare and threatened plant species. Ongoing discovery and taxonomic description of new species, many of which are rare, increases the challenges for recovery of threatened species and prioritisation of conservation actions. Current conservation of this diverse flora is based on integrated and scientific evidence-based management. Here we present an overview of current approaches to the conservation of threatened flora in the SWAFR with a focus on active management through recovery and restoration that is integrated with targeted research. Key threats include disease, fragmentation, invasive weeds, altered fire regimes, grazing, altered hydro-ecology and climate change. We highlight the integrated approach to management of threats and recovery of species with four case studies of threatened flora recovery projects that illustrate the breadth of interventions ranging from In situ management to conservation reintroductions and restoration of threatened species habitats. Our review and case studies emphasise that despite the scale of the challenge, a scientific understanding of threats and their impacts enables effective conservation actions to arrest decline and enhance recovery of threatened species and habitats.展开更多
Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but the...Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but there is currently limited reliable data indicating density and population size. This hinders the development of conservation action plans, including population monitoring, for this species. To address this data gap, we assessed lions’ demography and population estimates (population size and density) in the Katavi National Park using a call-back survey method. In addition, we assessed ecological factors that influenced distribution of lions to the call-back stations. Our estimated population size revealed 84 lions (95% CI 53 - 116), with a density of 5/100 km<sup>2</sup> (95% CI 3.14 - 6.86) in the sampled area, representing 38% of the total park. This resulted in an estimated 214 individuals when extrapolated to the whole park. Sixty-seven percent of lions that responded to the stations were female, and ecological factors that significantly influenced their distribution included elevation, land cover, precipitation, temperature, wind speed, and prey abundance. Our results suggest that female lions are more abundant than males in Katavi National Park and that population size and density estimates, as well as understanding prey-lion relations, are important indices for lion monitoring and identifying conservation priorities. Further, our study suggests that the call-back survey method is an effective, rapid, and less costly population assessment method for lions, may be useful for assessing other social species in the Katavi ecosystem and can be a useful tool for community engagement and contributing to scientific monitoring.展开更多
The Sociable Lapwing(Vanellus gregarius) was recently categorized as Critically Endangered by the IUCN due to a strong decline and overall range contraction.Until now the only published Chinese record of the species w...The Sociable Lapwing(Vanellus gregarius) was recently categorized as Critically Endangered by the IUCN due to a strong decline and overall range contraction.Until now the only published Chinese record of the species was a vagrant sighting in 1998.We reviewed reports and historic literature from a German ornithological expedition in 1876,which reported the species to be a breeding bird in Xinjiang,western China in the second half of the 19th century.According to local expertise,the species seems since to have become extinct in Xinjiang,but surveys are suggested to clarify its current status.展开更多
Objective: According to theory of Chinese medicine property, the ecological environment shapes properties(natures and flavors) of Chinese materia medica(CMM) and there are close relationships between certain natures a...Objective: According to theory of Chinese medicine property, the ecological environment shapes properties(natures and flavors) of Chinese materia medica(CMM) and there are close relationships between certain natures and flavors. However, to date these observations have not been validated scientifically in the context of the whole flora of a region. The present study aims to address this gap.Methods: We collected geographical distributions of 3637 vascular plant species native to the Xinjiang region of northwest China, of which around 812 are medicinal plants. The CMM property characters of these medicinal plants were also collected. All medicinal plants were then analyzed in the occurrence of their natures(cold, cool, neutral, warm, and hot) and flavors(sweet, bitter, sour, salty, and pungent). Possible correlations between these properties and environmental factors, notably climate, as well as correlations with plant species richness of the wider native flora of Xinjiang were then investigated using permutation test and regression.Results: Cold species(38.5%) were more numerous than warm(21.0%) and neutral(22.3%), while bitter species(43.3%) were more numerous than pungent(25.6%), sweet(22.4%) and sour(6.7%) ones. Species with bitter flavor were most commonly also cold(48.6%) in nature, sour flavor usually coincided with cold(44.2%) or cool nature(26.0%), whereas pungent or sweet species tended to be warm(34.4%, 28.4%) or neutral(27.8%, 28.4%). The percentages of species of cold/cool nature, bitter flavor were higher in mountainous regions, and the percentages of warm/neutral and pungent/sweet/sour were higher in basins. The percentages of species of cold/cool, bitter were positively correlated with actual evapotranspiration(AET),and also plant species richness but had a bell-shaped relationship with potential evapotranspiration(PET),whereas the inverse situation was shown for warm/neutral and pungent/sweet/sour species.Conclusion: Analysis of the data in Xinjiang region of China supports the qualitative observations concerning natures and flavors in traditional theory of Chinese medicine property. Specifically,(i) certain natures and flavors co-occur more frequently than if randomly distributed;(ii) correlations between proportions of natures and flavors and climatic variables suggest a role for the environment in shaping the properties of CMM.展开更多
Developing countries,which contribute 90%of global aquaculture production,are considered global climate risk hotspots.However,no study focuses on measuring district-or sub-national-level aquaculture vulnerability to c...Developing countries,which contribute 90%of global aquaculture production,are considered global climate risk hotspots.However,no study focuses on measuring district-or sub-national-level aquaculture vulnerability to climatic hazards or disasters.This study has measured the level of aquaculture vulnerability to climate variability and change in all 64 districts of Bangladesh using a composite vulnerability index approach(using 19 climatic,environmental and socio-economic indicators)and geographical information system(GIS).The results reveal that aquaculture in 12 districts namely Satkhira,Mymensingh,Panchagarh,Lalmonirhat,Nilphamari,Thakurgaon,Sunamganj,Dinajpur,Kurigram,Noakhali,Lakshmipur,and Cox's Bazar have very high vulnerability(in order of highest to lowest vulnerability),which are explained by their higher level of exposure,moderate level of sensitivity,and lower to moderate level of adaptive capacity.Among these,8 districts belong to inland and 4 districts to coastal regions of the country.Three districts,namely Dhaka,Chittagong,and Bandarban,have the lowest level of aquaculture vulnerability(in order of lowest to highest vulnerability)mainly because of very high adaptive capacity and moderate or low level of sensitivity and exposure.This study will punctuate the vulnerability of inland aquaculture and develop and prioritize actions to reduce the climatic impacts.展开更多
文摘Regardless of the excellent properties of glass ionomer cements,their poor mechanical properties limit their applications to non-load bearing areas.This study aimed to investigate the effect of incorporated short,chopped and randomly distributed flax fibers(0,0.5,1,2.5,5 and 25 wt%) on setting reaction kinetics,and mechanical and morphological properties of glass ionomer cements.Addition of flax fibers did not significantly affect the setting reaction extent.According to their content,flax fibers increased the compressive(from 148 to 250 MPa) and flexure strength(from 20 to 42 MPa).They also changed the brittle behavior of glass ionomer cements to a plastic one.They significantly reduced the compressive(from 3 to 1.3 GPa) and flexure modulus(from 19 to 14 GPa).Accordingly,flax fiber-modified glass ionomer cements could be potentially used in high-stress bearing areas.
文摘Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km<sup>2 </sup>revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km<sup>2 </sup>during the wet season, and 6.3/100 km<sup>2</sup> during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.
基金funded by Australian and Western Australian government threatened species and natural resources management initiativesGeraldton Regional Herbarium Group+4 种基金Central West College of Technical and Further EducationNorthern Agricultural Catchment CouncilWestern Mulga, Greenough Regional PrisonCity of Geraldton Community Nurserythe Department of Environment and Energy's ‘20 Million Trees Program’ and Western Australian State Natural Resource Management Program.
文摘The Southwest Australian Floristic Region(SWAFR) is a global biodiversity hotspot with high plant diversity and endemism and a broad range of threatening processes. An outcome of this is a high proportion of rare and threatened plant species. Ongoing discovery and taxonomic description of new species, many of which are rare, increases the challenges for recovery of threatened species and prioritisation of conservation actions. Current conservation of this diverse flora is based on integrated and scientific evidence-based management. Here we present an overview of current approaches to the conservation of threatened flora in the SWAFR with a focus on active management through recovery and restoration that is integrated with targeted research. Key threats include disease, fragmentation, invasive weeds, altered fire regimes, grazing, altered hydro-ecology and climate change. We highlight the integrated approach to management of threats and recovery of species with four case studies of threatened flora recovery projects that illustrate the breadth of interventions ranging from In situ management to conservation reintroductions and restoration of threatened species habitats. Our review and case studies emphasise that despite the scale of the challenge, a scientific understanding of threats and their impacts enables effective conservation actions to arrest decline and enhance recovery of threatened species and habitats.
文摘Lion populations are declining globally, including in Tanzania, and Africa. However, Katavi National Park is a landscape with potential for a sustainable and healthy population of African lions (Panthera leo), but there is currently limited reliable data indicating density and population size. This hinders the development of conservation action plans, including population monitoring, for this species. To address this data gap, we assessed lions’ demography and population estimates (population size and density) in the Katavi National Park using a call-back survey method. In addition, we assessed ecological factors that influenced distribution of lions to the call-back stations. Our estimated population size revealed 84 lions (95% CI 53 - 116), with a density of 5/100 km<sup>2</sup> (95% CI 3.14 - 6.86) in the sampled area, representing 38% of the total park. This resulted in an estimated 214 individuals when extrapolated to the whole park. Sixty-seven percent of lions that responded to the stations were female, and ecological factors that significantly influenced their distribution included elevation, land cover, precipitation, temperature, wind speed, and prey abundance. Our results suggest that female lions are more abundant than males in Katavi National Park and that population size and density estimates, as well as understanding prey-lion relations, are important indices for lion monitoring and identifying conservation priorities. Further, our study suggests that the call-back survey method is an effective, rapid, and less costly population assessment method for lions, may be useful for assessing other social species in the Katavi ecosystem and can be a useful tool for community engagement and contributing to scientific monitoring.
基金funded by the Darwin Initiative of the UK government and the Royal Society for the Protection of Birds (RSPB)support from Swarovski optics, The Rufford Foundation and Deutsche Ornithologen-Gesellschaft (DO-G)
文摘The Sociable Lapwing(Vanellus gregarius) was recently categorized as Critically Endangered by the IUCN due to a strong decline and overall range contraction.Until now the only published Chinese record of the species was a vagrant sighting in 1998.We reviewed reports and historic literature from a German ornithological expedition in 1876,which reported the species to be a breeding bird in Xinjiang,western China in the second half of the 19th century.According to local expertise,the species seems since to have become extinct in Xinjiang,but surveys are suggested to clarify its current status.
基金funded by National Natural Science Foundation of China (NSFC 81560660, 81503183)
文摘Objective: According to theory of Chinese medicine property, the ecological environment shapes properties(natures and flavors) of Chinese materia medica(CMM) and there are close relationships between certain natures and flavors. However, to date these observations have not been validated scientifically in the context of the whole flora of a region. The present study aims to address this gap.Methods: We collected geographical distributions of 3637 vascular plant species native to the Xinjiang region of northwest China, of which around 812 are medicinal plants. The CMM property characters of these medicinal plants were also collected. All medicinal plants were then analyzed in the occurrence of their natures(cold, cool, neutral, warm, and hot) and flavors(sweet, bitter, sour, salty, and pungent). Possible correlations between these properties and environmental factors, notably climate, as well as correlations with plant species richness of the wider native flora of Xinjiang were then investigated using permutation test and regression.Results: Cold species(38.5%) were more numerous than warm(21.0%) and neutral(22.3%), while bitter species(43.3%) were more numerous than pungent(25.6%), sweet(22.4%) and sour(6.7%) ones. Species with bitter flavor were most commonly also cold(48.6%) in nature, sour flavor usually coincided with cold(44.2%) or cool nature(26.0%), whereas pungent or sweet species tended to be warm(34.4%, 28.4%) or neutral(27.8%, 28.4%). The percentages of species of cold/cool nature, bitter flavor were higher in mountainous regions, and the percentages of warm/neutral and pungent/sweet/sour were higher in basins. The percentages of species of cold/cool, bitter were positively correlated with actual evapotranspiration(AET),and also plant species richness but had a bell-shaped relationship with potential evapotranspiration(PET),whereas the inverse situation was shown for warm/neutral and pungent/sweet/sour species.Conclusion: Analysis of the data in Xinjiang region of China supports the qualitative observations concerning natures and flavors in traditional theory of Chinese medicine property. Specifically,(i) certain natures and flavors co-occur more frequently than if randomly distributed;(ii) correlations between proportions of natures and flavors and climatic variables suggest a role for the environment in shaping the properties of CMM.
文摘Developing countries,which contribute 90%of global aquaculture production,are considered global climate risk hotspots.However,no study focuses on measuring district-or sub-national-level aquaculture vulnerability to climatic hazards or disasters.This study has measured the level of aquaculture vulnerability to climate variability and change in all 64 districts of Bangladesh using a composite vulnerability index approach(using 19 climatic,environmental and socio-economic indicators)and geographical information system(GIS).The results reveal that aquaculture in 12 districts namely Satkhira,Mymensingh,Panchagarh,Lalmonirhat,Nilphamari,Thakurgaon,Sunamganj,Dinajpur,Kurigram,Noakhali,Lakshmipur,and Cox's Bazar have very high vulnerability(in order of highest to lowest vulnerability),which are explained by their higher level of exposure,moderate level of sensitivity,and lower to moderate level of adaptive capacity.Among these,8 districts belong to inland and 4 districts to coastal regions of the country.Three districts,namely Dhaka,Chittagong,and Bandarban,have the lowest level of aquaculture vulnerability(in order of lowest to highest vulnerability)mainly because of very high adaptive capacity and moderate or low level of sensitivity and exposure.This study will punctuate the vulnerability of inland aquaculture and develop and prioritize actions to reduce the climatic impacts.