Improving pedestrian safety using combined HOG and Haar partial detection in mobile systems

Objective: The objective of this study is to develop a novel algorithm on a mobile system that can warn drivers about the possibility of a collision with a pedestrian. The constraints of the algorithm are near-real-time detection speed and a good detection rate.

Method: Histogram of gradients (HOG)-based detection is widely used in pedestrian safety applications; however, it has low detection speed for real-time systems. Hence, it has no direct usage for mobile systems. In order to achieve near-real-time detection speed, partial Haar transform predetections are applied to an image before HOG detection. The partial and HOG detections are merged and a score-based confidence level is defined for the final detection phase. In this way, the outcome is prioritized and different warning levels can be issued to warn the driver before a possible pedestrian collision.

Results: The proposed algorithm provides an increase in detection speed (from 46 to 76 fps) and detection rate (from 80 to 91%) with respect to HOG-based pedestrian detection. It also improves confidence of the results by multidetection merging and score assignment to detections.

Conclusions: Performance improvement of the algorithm is compared with respect to state-of-the-art detectors/algorithms. Based on the detection rate and detection speed performance, it can be concluded that the proposed algorithm is suitable to be used for mobile systems to warn drivers about the possibility of collision with a pedestrian.     

Assessing the components of adaptive capacity to improve conservation and management efforts under global change

Natural‐resource managers and other conservation practitioners are under unprecedented pressure to categorize and quantify the vulnerability of natural systems based on assessment of the exposure, sensitivity, and adaptive capacity of species to climate change. Despite the urgent need for these assessments, neither the theoretical basis of adaptive capacity nor the practical issues underlying its quantification has been articulated in a manner that is directly applicable to natural‐resource management. Both are critical for researchers, managers, and other conservation practitioners to develop reliable strategies for assessing adaptive capacity. Drawing from principles of classical and contemporary research and examples from terrestrial, marine, plant, and animal systems, we examined broadly the theory behind the concept of adaptive capacity. We then considered how interdisciplinary, trait‐ and triage‐based approaches encompassing the oft‐overlooked interactions among components of adaptive capacity can be used to identify species and populations likely to have higher (or lower) adaptive capacity. We identified the challenges and value of such endeavors and argue for a concerted interdisciplinary research approach that combines ecology, ecological genetics, and eco‐physiology to reflect the interacting components of adaptive capacity. We aimed to provide a basis for constructive discussion between natural‐resource managers and researchers, discussions urgently needed to identify research directions that will deliver answers to real‐world questions facing resource managers, other conservation practitioners, and policy makers. Directing research to both seek general patterns and identify ways to facilitate adaptive capacity of key species and populations within species, will enable conservation ecologists and resource managers to maximize returns on research and management investment and arrive at novel and dynamic management and policy decisions.     

非对称开采条件下工作面“多向应力”变化特征研究

在非对称开采条件下,工作面受上覆岩层自重应力、超前支承应力、采空区侧向支承应力和回风巷煤柱应力等“多向应力”叠加影响,使得工作面应力呈“非对称”性。为研究非对称开采条件下工作面“多向应力”变化特征,基于微震监测、应力在线监测和理论计算,对母杜柴登煤矿30202工作面回采过程中所形成的非对称开采条件下的应力变化进行分析;并基于工作面所受应力条件和围岩体结构条件,分析了“多向应力”叠加显现机理。结果表明:30202工作面回采期间,煤柱支承应力沿走向分为应力升高区、应力明显降低区、应力缓慢降低区和应力稳定区,其应力峰值主要集中在工作面前方40 m左右,应力集中系数平均为1.61;在非对称开采阶段,在走向方向工作面超前支承应力影响范围较回采初期增加了100 m左右;在不考虑垂直应力影响的情况下,相邻工作面采空区的侧向应力对30202工作面倾向方向的影响范围为44 m,应力最大值为56.1 MPa。在“多向应力”耦合作用下工作面在回采过程中产生能量集聚,并在采动扰动下发生能量释放,满足了大能量事件发生的基本应力条件;同时在扰动条件下采空区发生高位顶板错动,以及围岩支护薄弱为大能量事件的发生提供了围岩结构条件。研究结果可为工作面非对称开采条件下采场矿压显现规律研究、顶板控制和巷道支护设计提供指导。     

几株光合细菌的表型特征及DNA－NDA同源性分析

对５株新分离的光合细菌从形态、生理生化及ＤＮＡ－ＤＮＡ同源性等方面进行了研究．结果表明，菌株８与深红红螺菌（Ｐｈｏｄｏｓｐｉｒｉｌｌｕｍｒｕｂｒｕｍ）的模式菌株ＡＴＣＣ１１１７０的ＤＮＡ－ＤＮＡ同源性为９７％，菌株３７与沼泽红假单胞菌（Ｒｈｏｄｏｐｓｅｕｄｏｍｏｎａｓｐａｌｕｓｔｒｉｓ）的模式菌株ＡＴＣＣ１７００１的ＤＮＡ－ＤＮＡ同源性为８０％；菌株５５与球形红杆菌（Ｒｈｏｄｏｂａｃｔｅｒｓｐｈａｅｒｏｉｄｅｓ）的模式菌株ＡＴＣＣ１７０２３的ＤＮＡ－ＤＮＡ同源性为７１％；菌株４０和５２分别为另外两个ＤＮＡ同源群．根据各菌株形态、生理生化等表型特征以及ＤＮＡＧ＋Ｃｍｏｌ％和ＤＮＡ－ＤＮＡ同源性分析结果，确定了几株光合细菌的分类地位．     

浙江天台山茶树光合日变化及光响应

自然条件下使用LCA－4型便携式光合测定系统研究了栽培天天台山主峰华顶山的茶树连体叶片的光合日变化及光响应。结果表明：在初夏晴天,上年越冬叶片（下称二年生叶）的光合速率,表观量子效率,羧化效率和饱和光强比展叶红16d的一年生叶高,CO2补偿点和光补偿点比一年生叶低,两者的净光合速率日进程曲线均为“双峰”型,午间胞间CO2浓度上升表明,此时净光合速率下降主要受非气孔限制因素的影响。一年生叶蒸腾速率高于二年生叶,它们日进程曲线为单峰河,午间最高,而气孔阻力进间最低。不同时段作光响应和CO2响应试验表明,上午茶树的表观量子效率,饱和光强和羧化效率较高,光补偿点和CO2补偿点较低。图3表4参26     

Patterns of sperm use in the scorpionfly Panorpa germanica L. (Mecoptera: Panorpidae)

Sperm competition can be a powerful selective force in the evolution of reproductive strategies and mating systems. In studies on sperm competition, patterns of sperm use are typically reported as the mean species value of P ₂, determined as the proportion of offspring sired by the second male to copulate with a doubly mated female. However, the within-species variance in P ₂ has mostly been ignored, although taking this variance into account may be crucial for understanding the underlying mechanisms of sperm competition. Paternity analysis among the offspring of doubly mated females of Panorpa germanica (Mecoptera, Panorpidae) revealed a relationship between relative copulation durations of both males and the proportion of offspring each male will sire. This correlation between proportional copulation durations and paternity suggests mixing of sperm from different males inside the female’s spermatheca. Yet, sperm mixing appears to be incomplete, as paternity was overall slightly shifted towards the second male on average fathering a higher proportion of the offspring than its relative copulation duration would predict in case of complete sperm mixing. For individual males, however, the outcome of sperm competition is rather unpredictable as the intraspecific variance in P ₂ was found to be very high, irrespective of copulation durations. Possible causes of the observed variance in P ₂ and the partial last male sperm precedence are discussed.     

宜兴、溧阳河流主要水质指标的年际变化与成因分析

探讨了宜溧地区河流水环境的演化趋势及其主要影响因子。结果表明 :总磷总氮年际变化无明显上升趋势 ,CODMn则相反 ;影响CODMn浓度变化的因子是工业点源排放 ,影响总氮浓度变化的因子是化肥使用量 ,影响总磷浓度变化的因子是生活污染。     

Colony level sex allocation in a polygynous and polydomous ant

The colony-level sex allocation pattern of eusocial Hymenoptera has attracted much attention in recent studies of evolutionary biology. We conducted a theoretical and empirical study on this subject using the dolichoderine ant Technomyrmex albipes. This ant is unusual in having a dispersal polymorphism in both males and females. New colonies are founded by an alate female after mating with one or more alate males in the nuptial flight. In mature colonies, the reproductive role of the foundress queen is taken over by wingless offspring (supplementary reproductives). Mature colonies are extremely polygynous, with many wingless queens reproducing through intea-colonial mating with wingless males (inbreeding), and producing both alate and wingless sexuals. The population sex ratio of wingless sexuals was found to be extremely female-biased, while the population allocation ratio of alates was almost 1:1. This result suggests that there is local mate competition among wingless sexuals. A specific model for this extraordinary life cycle predicted that the asymmetry of regression relatedness (b _f/b _m) will disappear during the first few generations of wingless reproductives after the foundress dies. If colonies begin to produce alates after several wingless generations, this undermines the hypotheses for intercolonial sex ratio variation based on the relatedness asymmetry. We compared the magnitude of variation in sex ratios and other characteristics between two levels (within-colony-inter-nest and between-colony). Although there was considerable within-colony variation in all the examined characteristics, between-colony variances were always larger. This means that allocation is important at the whole-colony level, not that of the nest. There was no apparent correlation between the sex ratio of alates and colony size. Furthermore, partial correlation analysis indicated that neither the number of workers nor investment in alates explained the variation in the sex ratio of alates. The only factor which was significantly correlated with the sex ratio of alates was the sex ratio of wingless sexuals (a positive correlation). We conclude that both the alate and wingless sex ratios may be influenced by a common primary sex ratio at the egg stage, the variance of which may have genetic components. In the wingless sexuals, partial correlation analysis indicated that colony size and the number of workers explained the sex allocation ratio. The number of wingless females was strongly (positively) correlated with the total investment in wingless sexuals, while the number of males showed no such correlation. There is, however, no convincing explanation for the variation in sex allocation ratio of wingless sexuals, because the estimates of investment in wingless males may have a large sampling error. Correspondence to: K. Tsuji     

Leaf variation in iridoid glycoside content ofPlantago lanceolata (Plantaginaceae) and oviposition of the buckeye,Junonia coenia (Nymphalidae)

Summary Chemical analysis of each individual leaf of fivePlantago lanceolata (Plantaginaceae) plants showed that iridoid glycoside content increased from undetectable in the oldest photosynthetic leaves to over 9% dry weight in the youngest leaves. The relative proportion of the two iridoid glycosides inP. lanceolata also changed with leaf age: older leaves had significantly more aucubin, whereas the youngest leaves had primarily or solely catalpol. Oviposition tests with femaleJunonia coenia (Nymphalidae) butterflies, showed that they laid most of their eggs on new leaves.     

Environmental and genetic influences on mating strategies along a replicated food availability gradient in guppies (Poecilia reticulata)

Food availability is expected to influence the relative cost of different mating tactics, but little attention has been paid to this potential source of adaptive geographic variation in behavior. Associations between the frequency of different mating tactics and resource availability could arise because tactic use responds directly to food intake (phenotypic plasticity), because populations exposed to different average levels of food availability have diverged genetically in tactic use, or both. Different populations of guppies (Poecilia reticulata) in Trinidad experience different average levels of food availability. We combined field observations with laboratory “common garden” and diet experiments to examine how this environmental gradient has influenced the evolution of male mating tactics. Three independent components of variation in male behavior were found in the field: courtship versus foraging, dominance interactions, and interference competition versus searching for mates. Compared with low-food-availability sites, males at high-food-availability sites devoted more effort to interference competition. This difference disappeared in the common garden experiment, which suggests that it was caused by phenotypic plasticity and not genetic divergence. In the diet experiment, interference competition was more frequent and intense among males raised on the greater of two food levels, but this was only true for fish descended from sites with low food availability. Thus, the association between interference competition and food availability in the field can be attributed to a genetically variable norm of reaction. Genetically variable norms of reaction with respect to food intake were found for the other two behavioral components as well and are discussed in relation to the patterns observed in the field. Our results indicate that food availability gradients are an important, albeit complex, source of geographic variation in male mating strategies.