A Bayesian Analysis of Abundance,Trend, and Population Viability for Harbor Seals in Iliamna Lake,Alaska

Harbor seals in Iliamna Lake, Alaska, are a small, isolated population, and one of only two freshwater populations of harbor seals in the world, yet little is known about their abundance or risk for extinction. Bayesian hierarchical models were used to estimate abundance and trend of this population. Observational models were developed from aerial survey and harvest data, and they included effects for time of year and time of day on survey counts. Underlying models of abundance and trend were based on a Leslie matrix model that used prior information on vital rates from the literature. We developed three scenarios for variability in the priors and used them as part of a sensitivity analysis. The models were fitted using Markov chain Monte Carlo methods. The population production rate implied by the vital rate estimates was about 5% per year, very similar to the average annual harvest rate. After a period of growth in the 1980s, the population appears to be relatively stable at around 400 individuals. A population viability analysis assessing the risk of quasi‐extinction, defined as any reduction to 50 animals or below in the next 100 years, ranged from 1% to 3%, depending on the prior scenario. Although this is moderately low risk, it does not include genetic or catastrophic environmental events, which may have occurred to the population in the past, so our results should be applied cautiously.     

A New Methodology for Before–After Safety Assessment Using Survival Analysis and Longitudinal Data

The widely used empirical Bayes (EB) and full Bayes (FB) methods for before–after safety assessment are sometimes limited because of the extensive data needs from additional reference sites. To address this issue, this study proposes a novel before–after safety evaluation methodology based on survival analysis and longitudinal data as an alternative to the EB/FB method. A Bayesian survival analysis (SARE) model with a random effect term to address the unobserved heterogeneity across sites is developed. The proposed survival analysis method is validated through a simulation study before its application. Subsequently, the SARE model is developed in a case study to evaluate the safety effectiveness of a recent red‐light‐running photo enforcement program in New Jersey. As demonstrated in the simulation and the case study, the survival analysis can provide valid estimates using only data from treated sites, and thus its results will not be affected by the selection of defective or insufficient reference sites. In addition, the proposed approach can take into account the censored data generated due to the transition from the before period to the after period, which has not been previously explored in the literature. Using individual crashes as units of analysis, survival analysis can incorporate longitudinal covariates such as the traffic volume and weather variation, and thus can explicitly account for the potential temporal heterogeneity.     

高薪养廉的必要性和约束条件分析

文章首先从政府和公务员之间的委托代理关系、人力资本的消耗和补偿、历史经验三个方面论述了高薪养廉的必要性 ;其次 ,分析了高薪养廉的约束条件 ;最后得出结论 ,高薪只是养廉的必要条件 ,但并非充分条件。它的真正实行 ,不但需要生产力发展的经济基础 ,而且还需要收入分配制度的改革、法律监督机制的健全、官僚机构的自身完善     

无理数e在电路基本理论中出现的物理意义

对无理数e在电路分析中出现的几个典型例子作了分析讨论，明确指出：由1／e决定的特征常数可以在时间分布上和空间分布上，把一个按指数规律非均匀变化的问题，用一个等效的均匀变化的问题来表示；可以反映初始变化率与最终稳定值之间的联系；可以更深刻地反映某些物理过程的本质特征。     

不动产物权变动登记外的公示方式

按现有立法,不动产物权变动的公示方式均是登记。但立法上却有不登记的例外,实践中也有这种需要。如果法律上能够明确,在一定条件下,不动产的物权变动可以以登记外的公示方式存在,它对于保障交易安全、提高交易效率具有较强的现实意义。为了减少负面效应——实施这种公示方式可能出现的问题,如二重买卖、重复抵押等,可采取相应的措施予以解决。     

大学生思想道德建设的理性思考

目前 ,大学生的思想道德主流是积极、健康、向上的 ;但由于当前各种社会思潮和社会上的思想道德观念多元化的影响 ,不可避免地对青年学生的立场和观念产生了冲击。笔者在分析了当前大学生思想道德现状的基础上 ,找出存在的问题 ,并有针对性地提出了一系列的教育对策 ,以期更好地开展思想教育工作。     

小说的生命叙事与人的生命建构

生命叙事把对人类肉身生存境况的关怀逐步推进到类似宗教境界的精神追求；它描述生命从物质到精神的孕育、产生、冲突、升腾的变化过程，是在对生命现实反思基础上的想像和升华。生命叙事的起点及归宿都是对蓬勃的生命状态的渴望和追求，它把叩问人类心灵的意义、建构理想的生命作为自己的神圣使命。     

几个一致连续的充要条件

本文利用极限定义及归结原则等方法,给出了几个一致连续的充要条件,得到了判定函数一致连续的有效方法。     

制造企业生存和发展的推动力--技术创新

技术创新是制造企业发展的原动力和核心竞争力.培养员工的创新精神,营造有利于创新的企业文化环境,制定符合制造企业发展要求的创新策略,建立鼓励创新的管理机制和创新能力评价体系是提高制造企业创新能力的关键.     

局部Haar条件下的变形非线性L逼近

本文讨论了局部Ｈａａｒ条件下变形的非线性Ｌ逼近，得到了包括交错定理在内的特征定理、唯一性和强唯一性定理。