Extinction risk of the endemic vascular flora of Kauai,Hawaii, based on IUCN assessments

The International Union for Conservation of Nature's Red List of Threatened Species (IUCN Red List) is the world's most comprehensive information source on the global conservation status of species. Governmental agencies and conservation organizations increasingly rely on IUCN Red List assessments to develop conservation policies and priorities. Funding agencies use the assessments as evaluation criteria, and researchers use meta-analysis of red-list data to address fundamental and applied conservation science questions. However, the circa 143,000 IUCN assessments represent a fraction of the world's biodiversity and are biased in regional and organismal coverage. These biases may affect conservation priorities, funding, and uses of these data to understand global patterns. Isolated oceanic islands are characterized by high endemicity, but the unique biodiversity of many islands is experiencing high extinction rates. The archipelago of Hawaii has one of the highest levels of endemism of any floristic region; 90% of its 1367 native vascular plant taxa are classified as endemic. We used the IUCN's assessment of the complete single-island endemic (SIE) vascular plant flora of Kauai, Hawaii, to assess the proportion and drivers of decline of threatened plants in an oceanic island setting. We compared the IUCN assessments with federal, state, and other local assessments of Kauai species or taxa of conservation concern. Finally, we conducted a preliminary assessment for all 1044 native vascular plants of Hawaii based on IUCN criterion B by estimating area of occupancy, extent of occurrence, and number of locations to determine whether the pattern found for the SIE vascular flora of Kauai is comparable to the native vascular flora of the Hawaiian Islands. We compared our results with patterns observed for assessments of other floras. According to IUCN, 256 SIE vascular plant taxa are threatened with extinction and 5% are already extinct. This is the highest extinction risk reported for any flora to date. The preliminary assessment of the native vascular flora of Hawaii showed that 72% (753 taxa) is threatened. The flora of Hawaii may be one of the world's most threatened; thus, increased and novel conservation measures in the state and on other remote oceanic islands are urgently needed.     

重型柴油车车载排放实测与加载影响研究

采用车载排放测试仪,对2辆重型柴油卡车在空载和加载条件下进行实际道路车载排放测试.通过分析获得了油耗与排放速率的速度-加速度及其工况点的分布,发现高油耗与高排放工况点主要集中在高速加速区域,加载时油耗与排放高值随工况点分布更广;车辆在(30±2.5)km·h^-1等速及加速行驶时受加载影响最大,此时加载油耗与排放约是空载的1.6～3.2倍左右;由实测结果发现,卡车Ⅰ和卡车Ⅱ加载时油耗及CO、HC、NO_x排放因子分别是空载的1.6倍、3.5倍、1.1倍、1.5倍以及1.2倍、1.0倍、0.9倍和1.5倍,加载对油耗与NO_x排放影响最为明显,对HC影响最小,CO影响取决于车辆保养水平;卡车Ⅱ较卡车Ⅰ车型更大,发动机功率更高,相同荷载时受加载影响较小,说明重型车在发动机负荷可承受的范围内合理装载,有助于避免油耗与排放恶化,提高燃油经济性和排放水平.     

Photocatalytic oxidation of soot by P25 TiO2 films

The photomineralisation of soot by P25 titania films is studied using FT-IR and the process shown to involve the oxidation of carbon to CO2 exclusively. The efficiency of this process is low, however, with a formal quantum efficiency of 1.1 x 10(-4) molecules of carbon oxidized per incident photon of UVA light. The cause of this low efficiency is attributed largely to the less than intimate contact between the fibrous soot layer and the surface of the photocatalyst.     

Biomechanical response targets for physical and computational models of the pediatric trunk

Objectives: This paper quantifies pediatric thoracoabdominal response to belt loading to guide the scaling of existing adult response data and to assess the validity of a juvenile porcine abdominal model for application to the development of physical and computational models of the human child. Methods: Table-top belt-loading experiments were performed on 6, 7, and 15 year-old pediatric post-mortem human subjects (PMHS). Response targets are reported for diagonal belt and distributed loading of the anterior thorax and for horizontal belt loading of the abdomen. Results: The pediatric PMHS exhibited abdominal response similar to the swine, including the degree of rate sensitivity. The thoraces of the PMHS were as stiff as, or slightly more stiff than, published adult corridors. Conclusions: An assessment of age-related changes in thoracic stiffness suggests that the effective stiffness of the chest increases through the fourth decade of life and then decreases, resulting in stiffness values similar for children and elderly adults.     

Minimizing opportunity costs to aquatic connectivity restoration while controlling an invasive species

Controlling invasive species is critical for conservation but can have unintended consequences for native species and divert resources away from other efforts. This dilemma occurs on a grand scale in the North American Great Lakes, where dams and culverts block tributary access to habitat of desirable fish species and are a lynchpin of long‐standing efforts to limit ecological damage inflicted by the invasive, parasitic sea lamprey (Petromyzon marinus). Habitat restoration and sea‐lamprey control create conflicting goals for managing aging infrastructure. We used optimization to minimize opportunity costs of habitat gains for 37 desirable migratory fishes that arose from restricting sea lamprey access (0–25% increase) when selecting barriers for removal under a limited budget (US$1–105 million). Imposing limits on sea lamprey habitat reduced gains in tributary access for desirable species by 15–50% relative to an unconstrained scenario. Additional investment to offset the effect of limiting sea‐lamprey access resulted in high opportunity costs for 30 of 37 species (e.g., an additional US$20–80 million for lake sturgeon [Acipenser fulvescens]) and often required ≥5% increase in sea‐lamprey access to identify barrier‐removal solutions adhering to the budget and limiting access. Narrowly distributed species exhibited the highest opportunity costs but benefited more at less cost when small increases in sea‐lamprey access were allowed. Our results illustrate the value of optimization in limiting opportunity costs when balancing invasion control against restoration benefits for diverse desirable species. Such trade‐off analyses are essential to the restoration of connectivity within fragmented rivers without unleashing invaders.     

Improving inferences about private land conservation by accounting for incomplete reporting

Private lands provide key habitat for imperiled species and are core components of function protectected area networks; yet, their incorporation into national and regional conservation planning has been challenging. Identifying locations where private landowners are likely to participate in conservation initiatives can help avoid conflict and clarify trade-offs between ecological benefits and sociopolitical costs. Empirical, spatially explicit assessment of the factors associated with conservation on private land is an emerging tool for identifying future conservation opportunities. However, most data on private land conservation are voluntarily reported and incomplete, which complicates these assessments. We used a novel application of occupancy models to analyze the occurrence of conservation easements on private land. We compared multiple formulations of occupancy models with a logistic regression model to predict the locations of conservation easements based on a spatially explicit social–ecological systems framework. We combined a simulation experiment with a case study of easement data in Idaho and Montana (United States) to illustrate the utility of the occupancy framework for modeling conservation on private land. Occupancy models that explicitly accounted for variation in reporting produced estimates of predictors that were substantially less biased than estimates produced by logistic regression under all simulated conditions. Occupancy models produced estimates for the 6 predictors we evaluated in our case study that were larger in magnitude, but less certain than those produced by logistic regression. These results suggest that occupancy models result in qualitatively different inferences regarding the effects of predictors on conservation easement occurrence than logistic regression and highlight the importance of integrating variable and incomplete reporting of participation in empirical analysis of conservation initiatives. Failure to do so can lead to emphasizing the wrong social, institutional, and environmental factors that enable conservation and underestimating conservation opportunities in landscapes where social norms or institutional constraints inhibit reporting.     

Effects of environmental factors on radiocadmium uptake by four species of marine bivalves

Temperature, salinity, bottom-sediment type, and zinc concentration all influenced Cd uptake by 4 marine bivalves (Mya arenaria, Mytilus edulis, Mulinia lateralis and Nucula proxima) in short-term static assay systems using ¹⁰⁹Cd as a tracer. The experimental system consisted of aquaria containing 20 l of seawater maintained under controlled light and temperature conditions. The water contained either 5 or 20 g/l Cd and tracer. Distribution and kinetics of the metal were monitored in the water column and organisms. The results demonstrate that Cd uptake rates differed widely among the organisms tested. An increase in temperature increased Cd uptake rate by all test organisms. A decrease in salinity increased Cd uptake by all organisms tested. The presence of bottom sediment depresses Cd accumulation in some benthic animals. Zinc in concentrations of 0.5 mg/l substantially decreased Cd uptake by Mytilus edulis and Mulinia lateralis. It is suggested that all important species and environmental variables be considered when studying heavy-metal uptake by marine organisms or when establishing water-quality criteria.