Urban shade as a cryptic habitat: fern distribution in building gaps in Sapporo,northern Japan

Urban Ecosystems - Biodiversity conservation and restoration in cities is a global challenge for the 21st century. Unlike other common ecosystems, urban landscapes are predominantly covered by...     

A characterization of the uniform rule with several commodities and agents

We consider a problem of allocating infinitely divisible commodities among a group of agents. More specifically, there are several commodities to be allocated and agents have continuous, strictly convex, and separable preferences. We establish that a rule satisfies strategy-proofness, unanimity, weak symmetry, and nonbossiness if and only if it is the uniform rule. This result extends to the class of continuous, strictly convex, and multidimensional single-peaked preferences.     

Why Do Black Men Suffer from Low Self‐Rated Job Productivity? A Multi‐Theory Approach*

This article uses data from a national representative employer–employee matched dataset to assess the race/sex disparity in workers’ self‐rated productivity levels. Findings show that a significant proportion of black men report that they cannot achieve high job productivity. We conduct regression analyses based on human capital, social closure, and social psychological models to identify the specific mechanisms that account for black men’s low self‐rated job productivity. We find that social psychological work relational issues such as closeness of supervision and job evaluation explain the race/sex disparity in self‐rated productivity. Findings are considered in the context of emergent intersections of race and gender in accounting for disparities in workplace outcomes.     

Risk Assessment of the Carbon Nanotube Group

This study assessed the health risks via inhalation and derived the occupational exposure limit (OEL) for the carbon nanotube (CNT) group rather than individual CNT material. We devised two methods: the integration of the intratracheal instillation (IT) data with the inhalation (IH) data, and the “biaxial approach.” A four‐week IH test and IT test were performed in rats exposed to representative materials to obtain the no observed adverse effect level, based on which the OEL was derived. We used the biaxial approach to conduct a relative toxicity assessment of six types of CNTs. An OEL of 0.03 mg/m³ was selected as the criterion for the CNT group. We proposed that the OEL be limited to 15 years. We adopted adaptive management, in which the values are reviewed whenever new data are obtained. The toxicity level was found to be correlated with the Brunauer‐Emmett‐Teller (BET)‐specific surface area (BET‐SSA) of CNT, suggesting the BET‐SSA to have potential for use in toxicity estimation. We used the published exposure data and measurement results of dustiness tests to compute the risk in relation to particle size at the workplace and showed that controlling micron‐sized respirable particles was of utmost importance. Our genotoxicity studies indicated that CNT did not directly interact with genetic materials. They supported the concept that, even if CNT is genotoxic, it is secondary genotoxicity mediated via a pathway of genotoxic damage resulting from oxidative DNA attack by free radicals generated during CNT‐elicited inflammation. Secondary genotoxicity appears to involve a threshold.     

Are Religious Factors Associated with Political Consumerism?An Exploratory Study

A national survey with 876 responses examined whether political consumerism is related to religious factors including beliefs about gay marriage, if the Bible is the literal word of God, religiosity or social capital, altruism or civic engagement, cognitive engagement, and the use of political social and digital media. Results suggest religious factors may be important in political consumption, with political consumers less likely to believe the Bible is the literal word of God, suggesting they perceive self-direction regarding their religious beliefs. Political consumers may exhibit universalism by participating in altruistic activities such as volunteering to help the poor, homeless and elderly. However, given their lack of support for gay marriage, traditional religious teachings may supersede universalism for certain social justice issues.     

Robust estimation of a high-dimensional integrated covariance matrix

In this article, we consider a robust method of estimating a realized covariance matrix calculated as the sum of cross products of intraday high-frequency returns. According to recent articles in financial econometrics, the realized covariance matrix is essentially contaminated with market microstructure noise. Although techniques for removing noise from the matrix have been studied since the early 2000s, they have primarily investigated a low-dimensional covariance matrix with statistically significant sample sizes. We focus on noise-robust covariance estimation under converse circumstances, that is, a high-dimensional covariance matrix possibly with a small sample size. For the estimation, we utilize a statistical hypothesis test based on the characteristic that the largest eigenvalue of the covariance matrix asymptotically follows a Tracy–Widom distribution. The null hypothesis assumes that log returns are not pure noises. If a sample eigenvalue is larger than the relevant critical value, then we fail to reject the null hypothesis. The simulation results show that the estimator studied here performs better than others as measured by mean squared error. The empirical analysis shows that our proposed estimator can be adopted to forecast future covariance matrices using real data.     

Maximal domain for strategy-proof probabilistic rules in economies with one public good

We consider the problem of choosing a level of a public good on an interval of the real line among a group of agents. A probabilistic rule chooses a probability distribution over the interval for each preference profile. We investigate strategy-proof probabilistic rules in the case where distributions are compared based on stochastic dominance relations. First, on a “minimally rich domain”, we characterize the so-called probabilistic generalized median rules (Ehlers et al., J Econ Theory 105:408–434, 2002) by means of stochastic-dominance (sd) strategy-proofness and ontoness. Next, we study how much we can enlarge a domain to allow for the existence of sd-strategy-proof probabilistic rules that satisfy ontoness and the no-vetoer condition. We establish that the domain of “convex” preferences is the unique maximal domain including a minimally rich domain for these properties.     

进化与偶然——日本生物学家带来的新见解

生物学哲学是科学哲学的领域之一,在欧美得到了积极研究,在该领域人们用从生物学得来的新知识来解决以往哲学中的各个问题,或用来揭示解决包含在生物学内的各种哲学问题的方案。日本的生物学研究处于世界领先地位,近年来生物学哲学在日本也受到瞩目。本文从“宿命论进化观”、“物理学信息”、“生物学信息”三个层面,就“进化”问题,提出日本生物学家带来的新见解。其一,“分子进化中立说”,即指在DNA分子水平的进化中,是由遗传漂变而非自然选择来发挥主要作用的;其二,“基因重复说”,即细胞内的染色体上重复存在着相同的DNA,但这些基因并不编砝氨基酸,因此并非所有的基因都是进化所必需的。     

A host shift from wild blue cohosh to cultivated potato by the phytophagous ladybird beetle, Epilachna yasutomii (Coleoptera, Coccinellidae)

Life history traits of the phytophagous ladybird beetle Epilachna yasutomii were compared between a nonpest population feeding on wild blue cohosh and a pest population feeding on cultivated solanaceous crops, mainly potato. Newly emerged adults of the nonpest population entered diapause early in midsummer when blue cohosh withered, while adults of the pest population were found in tomato and eggplant fields until late autumn. The pest population had larger females, a higher population growth rate, a shorter larval developmental period, and reduced longevity of overwintered females, compared with the nonpest population. ANOVA indicated that all these life history traits were influenced by the food plant, and that the number of eggs laid per female and the longevity of overwintered females were also affected by the population type. These findings suggest that the life history pattern of E. yasutomii changed to high fecundity with a short life span from low fecundity with a long life span as a result of the host shift from wild blue cohosh to cultivated solanaceous crops. Received: May 22, 1998 / Accepted: January 13, 1999