Effects of law enforcement and community outreach on mammal diversity in a biodiversity hotspot

Management activities such as law enforcement and community outreach are thought to affect conservation outcomes in protected areas, but their importance relative to intrinsic environmental characteristics of the parks and extrinsic human pressures surrounding the parks have not been explored. Furthermore, it is not clear which is more related to conservation outcomes—the management itself or local people's perceptions of the management. We measured objective (reports by park staff) and subjective (reports by local people) levels of community outreach and law enforcement based on responses to 374 questionnaires. We estimated mammal abundance and diversity of 6 protected areas based on data from 115 camera traps in Xishuangbanna, southwest China, a biodiversity hotspot with high hunting and land-conversion pressures. We then examined correlations among them and found that local people's perception of law enforcement was positively related to the local abundance of 2 large, hunted species, wild boar (Sus scrofa) (β = 15.22) and muntjac (Muntiacus vaginalis) (β = 14.82), but not related to the abundance of smaller mammals or to objective levels of enforcement. The subjective frequency of outreach by park staff to local communities (β = 3.42) and park size (β = 3.28) were significantly and positively related to mammal species richness, whereas elevation, human population density, and subjective frequency of law enforcement were not. We could not conclude that community outreach and law enforcement were directly causing increased mammal abundance and diversity. Nevertheless, the patterns we detected are some of the first empirical evidence consistent with the idea that biodiversity in protected areas may be more positively and strongly related to local perceptions of the intensity of park management than to either intrinsic (e.g., elevation, park size) or extrinsic (e.g., human population density) environmental factors.     

分子吸附器在光学相机污染控制中的应用研究

分子吸附器作为一种新型的在轨污染控制手段,具有使用方便、重量轻、无功耗和成本低等特点,可以为航天器光学相机提供在轨污染控制。从在轨分子污染物和分子吸附器特点两方面进行分析,描述了光学相机在轨污染物来源及特点,分析了污染物成分及对光学相机的危害,阐述了分子吸附器(包括吸附剂和基底)的组成及吸附特点。结合相机结构,提出了分子吸附器在光学相机污染控制中的应用方案,并明确了今后的研究方向。     

基于近地多光谱和OLI影像的黄河三角洲冬小麦种植区盐分估算及遥感反演——以山东省垦利县和无棣县为例

黄河三角洲是我国重要的后备土地资源区,而土壤盐渍化对该区的农业生产影响巨大,因此,及时获取该区农作物种植区土壤盐分含量及其分布具有重要意义。论文利用ADC便携式多光谱相机和EC110便携式盐分计,采集该区近地多光谱相片和土壤表层含盐量数据,结合两期遥感影像提取黄河三角洲冬小麦种植区面积分布,构建基于近地多光谱植被指数的土壤含盐量估算模型,进而将模型拟合反演到黄河三角洲OLI影像,得到黄河三角洲冬小麦种植区土壤盐分含量空间分布图,对麦区土壤盐分状况进行了分析。结果显示,土壤含盐量最佳估算模型为以SAVI为因变量的线性模型（Y=-0.754x+0.870,n=80）,估测R²为0.747,精度达到81.44%;研究区冬小麦分布由西南部内陆至东北部沿海呈明显递减的空间趋势;麦田土壤盐分含量主要集中在1.5~3.0 g/kg之间,占种植总面积的76.90%,而含盐大于3.0 g/kg的麦田占14.09%,宜采取针对性栽培管理措施。该研究探索了基于近地多光谱数据和OLI影像的土壤含盐量估算方法,为黄河三角洲麦田管理和土壤盐分含量估算提供了快速有效的技术手段。     

Mapping of the benthic communities in the Taranto seas using side-scan sonar and an underwater video camera

Side-scan sonar and underwater video camera records as well as dredging samples were used to map the bottom morphology and biocoenoses in the Taranto seas. A 1:20,000 scale chart has been produced with all the data recorded. Most of the study area consists of biocoenoses affected by the anthropogenic activities of the town of Taranto. Some native broadly tolerant species seem to benefit from these activities and become increasingly dominant. Environmental modifications also seem to favour the settlement of exotic species.     

温度分层环境下火灾烟气羽流上升高度公式分析

对小尺度空间温度分层环境下柴油有焰火及棉绳阴燃火烟气运动进行了实验和数值模拟.结果表明,在分层环境下,烟气与环境空气温度差造成的浮力在某一高度消失并转为负值,致使烟气停止上升而向横向扩展.Morton积分公式低估了烟气羽流上升的最大高度,且在相同出口条件及分层环境下,柴油烟雾比棉绳烟雾下降趋势快,上升高度小,其原因在于积分公式中自相似卷吸及烟气为空气假设.引入烟气密度修正系数和自相似修正系数,对Morton公式进行了修正和讨论.     

A causal analysis of time-varying speed camera safety effects based on the propensity score method

Introduction: Speed limit enforcement cameras provide an effective approach to reduce vehicle speeds and the number of road accidents. However, it is still unclear whether the safety effects of speed cameras show durability over long periods of time. This paper analyses how the effects of speed cameras on road accidents change over time. A total number of 771 camera sites and 4787 potential control sites are observed for a period of 18 years (1999–2016) across England. Method: Covariates such as road class, crash history, speed limit, and annual average daily traffic (AADT) are included in the data set. A difference in difference (DID) based propensity score matching (PSM) method is employed to select proper control sites and estimate the treatment effects. The safety effects of speed cameras are then evaluated from a long-term perspective. The post-treatment period is divided into four equal-length periods: early, medium 1 and 2, and late. Results and Conclusions: The results show that speed cameras have significantly reduced the number of road accidents near the camera sites. However, the effects vary across different time periods. The safety effects of speed cameras experienced a sharp decrease during the medium periods after an initial period of highly reduced accidents (medium 1: −53.1%, medium 2: −40.7%) and recovered slightly during the late period. In addition, to evaluate the criteria for selecting camera sites in the UK, we further investigated whether speed cameras at high risk sites have better safety performance. The results show that while safety effects at high risk camera sites also decreased during the medium periods, the reduction was smaller (medium 1: −20.8%, medium 2: −2.1%). Practical Applications: Appropriate road traffic regulations and management, as well as proper camera sites selection criterion, are important to maintain the effectiveness of speed cameras.     

石膏矿采空区顶板冒落冲击气浪传播规律及安全防范研究

为探索石膏矿采空区顶板冒落灾害形成及演化过程中的微观动力学行为,以某危害型石膏矿为研究背景,选择"打气筒"模型进行了空场法采空区顶板冒落相似物理模拟试验,并利用高速摄像及纹影技术,直观地记录分析冲击气浪产生时流场在直线型、转弯型、独头式模型巷道处的传播规律及变化特性.结果表明,在直线型巷道内传播时,冲击气浪并非按直线传递,而是气浪前端阵面会发生回转,与气浪尾部和后续的气浪叠加、交混,一起向前传递.在转弯型巷道中,冲击气浪传播至巷道转弯处时,气浪会马上在此改变传播方向,开始沿着转弯方向,向巷道出口传播.当气浪完全通过此处后,由于巷道围岩和空气的阻力,冲击气浪前端部分气流又会回流至此,进行二次破坏.在独头式巷道中传播时,由于巷道一端封合密闭,气体无法涌出,气浪无法在独头巷道中顺利向前传递,而是与巷道中的气浪相互叠加、碰撞,持续地、无规则地流动.     

USE OF TIME-LAPSE PHOTOGRAPHY TO ASSESS POTENTIAL INTERCEPTION IN ARIZONA PONDEROSA PINE1

ABSTRACT: The behavior of intercepted snow on a stand of uneven-aged ponderosa pine in east-central Arizona was evaluated with the use of a super 8-mm time lapse movie camera to determine the relative significance of snowfall interception in the water yield of this type forest. A snow load index was developed to estimate interception storage for two trees in the field of view for discrete time periods. The snow load index. photographs, and climatic data were combined to describe accumulation and to identify and rank according to relative magnitudes the basic processes of canopy snow removal. The rate of snow accumulation was nonlinear with initial storage being rapid. then slowing with time. Most of the intercepted snow eventually reached the snowpack on the ground by snowslide and wind erosion or by snowmelt and subsequent stemflow and drippmg of meltwater, and was therefore not considered a significant loss to the water budget on site. Some water apparently was disposed of by the evaporation of meltwater and sublimation of canopy snow, but these losses appeared to be comparatively minor.     

Dynamics of a low‐density tiger population in Southeast Asia in the context of improved law enforcement

Recovering small populations of threatened species is an important global conservation strategy. Monitoring the anticipated recovery, however, often relies on uncertain abundance indices rather than on rigorous demographic estimates. To counter the severe threat from poaching of wild tigers (Panthera tigris), the Government of Thailand established an intensive patrolling system in 2005 to protect and recover its largest source population in Huai Kha Khaeng Wildlife Sanctuary. Concurrently, we assessed the dynamics of this tiger population over the next 8 years with rigorous photographic capture‐recapture methods. From 2006 to 2012, we sampled across 624–1026 km² with 137–200 camera traps. Cameras deployed for 21,359 trap days yielded photographic records of 90 distinct individuals. We used closed model Bayesian spatial capture‐recapture methods to estimate tiger abundances annually. Abundance estimates were integrated with likelihood‐based open model analyses to estimate rates of annual and overall rates of survival, recruitment, and changes in abundance. Estimates of demographic parameters fluctuated widely: annual density ranged from 1.25 to 2.01 tigers/100 km², abundance from 35 to 58 tigers, survival from 79.6% to 95.5%, and annual recruitment from 0 to 25 tigers. The number of distinct individuals photographed demonstrates the value of photographic capture–recapture methods for assessments of population dynamics in rare and elusive species that are identifiable from natural markings. Possibly because of poaching pressure, overall tiger densities at Huai Kha Khaeng were 82–90% lower than in ecologically comparable sites in India. However, intensified patrolling after 2006 appeared to reduce poaching and was correlated with marginal improvement in tiger survival and recruitment. Our results suggest that population recovery of low‐density tiger populations may be slower than anticipated by current global strategies aimed at doubling the number of wild tigers in a decade.     

Quantification of turbulence in cryogenic liquid using high speed flow visualization

A high speed flow visualization experiment was conducted to characterize the boiling induced turbulence when a cryogenic liquid is released on water. The advective transport of turbulent structures traversing through the liquid was captured and reconstructed using image processing software to obtain information on velocity components. The numerical results obtained from image processing were used to determine turbulence parameters like turbulent intensity, turbulent kinetic energy and eddy dissipation rate. An interesting aspect of the study was the formation of wavy structures called ‘thermals’ which were characteristic of turbulent convection. The thermals were found to act as a catalyst in increasing heat transfer and turbulence between water and cryogenic pool. The turbulent intensity was influenced by the turbulent velocity and had direct effects on the vaporization flux. Among the turbulence parameters, increase in turbulent kinetic energy resulted in faster vaporization of cryogenic liquid through enhanced mixing, whereas variations in the eddy dissipation rate had weak dependence on vaporization. Additionally, the initial height of cryogenic liquid was also found to strongly affect the vaporization mass flux.