Non‐parametric Bayesian Intensity Model: Exploring Time‐to‐Event Data on Two Time Scales

Time‐to‐event data have been extensively studied in many areas. Although multiple time scales are often observed, commonly used methods are based on a single time scale. Analysing time‐to‐event data on two time scales can offer a more extensive insight into the phenomenon. We introduce a non‐parametric Bayesian intensity model to analyse two‐dimensional point process on Lexis diagrams. After a simple discretization of the two‐dimensional process, we model the intensity by a one‐dimensional piecewise constant hazard functions parametrized by the change points and corresponding hazard levels. Our prior distribution incorporates a built‐in smoothing feature in two dimensions. We implement posterior simulation using the reversible jump Metropolis–Hastings algorithm and demonstrate the applicability of the method using both simulated and empirical survival data. Our approach outperforms commonly applied models by borrowing strength in two dimensions.     

Effects of fragmentation and trampling on carabid beetle assemblages in urban woodlands in Helsinki, Finland

We studied the effects of fragmentation (edge effects and patch size) and trampling (path cover) on carabid beetle assemblages in urban woodland patches in Helsinki, Finland. We expected that (1) open habitat and generalist species would benefit and forest species would suffer from increased woodland fragmentation, and (2) most carabid species would respond negatively to increased levels of trampling. A total of 2088 carabid individuals representing 37 species were collected. A cluster analysis distinguished sites in the interior of large woodland patches, with low or moderate path cover, from the other sites. The other sites did not cluster meaningfully, suggesting increased variation in the carabid fauna with increasing human impact. All species and ecological species-groups decreased with increasing distance from the edge toward the woodland interior and with increasing patch size. This pattern is in accordance with our expectation for open habitat and generalist species but opposite to what we expected for forest species. The reason for these surprising results may be that (1) the species we collected are not true forest interior species, (2) urban woodland edges are optimal habitats for many forest carabids, or (3) edges are actually sub-optimal, and high catches simply reflect increased activity of beetles moving away from the edge. Trampling did not have an overall negative effect on carabids as hypothesized. Species associated with moist forest habitat responded as predicted: they decreased in abundance with increasing path cover. Furthermore, open habitat species decreased with increasing path cover but more straightforward than we had predicted. Model elaboration, by dropping the highly trampled sites from the analyses, suggested that our data of high trampling may be too scarce: the results without these sites were more in accordance with our predictions than with the full dataset.     

Is there a need for a theory of urban ecology?

Although urban ecosystems are governed by the same ecological laws as rural ecosystems, the relative importance of certain ecological patterns and processes differs between the two types of ecosystems. For instance, as compared to rural areas, urban habitats are usually more islandlike, more often represent early successional stages, and more easily invaded by alien species. All these features are results of the intense human influence on urban landscapes. The question then arises whether a distinct theory of urban ecology is needed for understanding ecological patterns and processes in the urban setting. The answer is no, because urban ecosystems can be successfully studied using existing ecological theories, such as the metapopulation theory. However, due to the intense human presence approaches that include the human aspect are useful in studying urban systems. For instance, the human ecosystem model, which emphasizes human impact by identifying social components with connections to ecology, is a useful approach in urban studies. This model, combined with the urban–rural gradient approach, forms an effective tool for studying key ecological features of urban ecosystems. Better understanding of these features would increase our ability to predict changes that land use causes in urban ecosystems, and would help to integrate ecology better into urban planning.     

地权结构和村庄民主对农户林业投入的影响

在民主实施集体林权改革的要求下,通过中国南方集体林区658户农户调研数据,运用两步法Double-Hurdle模型重点研究林地产权结构优化及村庄民主程序对农户林业投入的影响。研究发现林地使用权与处置权优化具有显著的投资激励效应,而林地使用权的投资激励效用不显著。更重要的是,村庄民主能够显著正向调节投资激励效应,主要是林地通过使用权与处置权发挥作用的。可能的解释为村庄民主程序能够显著增强农户对林地使用权与处置权的感知、认知与信心。基于研究结论,提出三个方面政策启示：（1）虽然新一轮改革具有一定的投资激励效应,但是法律与制度层面的林地产权制度并未完全落实,基层政府仍有进一步优化和推进改革配套政策有效落实的空间,尤其是要重视林农收益权的提升;（2）相关管理部门须进一步引导农户正确、充分地认知其对于自身林地资源享有的权利,增强农户对林地产权的认知与信心,以加强政策效能;（3）政府仍需推进村庄民主制度建设,加强农民在村庄公共事务决策中的话语权,运用村庄民主程序显化基层群众的政策需求,以辅助政府进行有效的政策供给。     

Coordinating co-production in complex network settings

This article draws together the concepts of network management and co-production with complexity sciences. So far, these approaches have rarely been connected in research literature. We suggest that this conceptual framework offers new insights for analyzing the challenges of co-production in complex network settings in the local public services. The aim of the article is to find out how complex network structures meet the co-production process in the context of social and health care services. The empirical part of the article presents a Finnish case study of a multiprofessional service network producing social and health care services for youth. Here, the clients, in this case children and young people with a need for social services, often need multiple services from different service providers simultaneously. Our research findings suggest that the outcomes of the service process are not only dependent on the client's needs, but rather on organizational and professional interests. Our research gives new insights for the discussion on co-production; when it is applied as an intended policy to improve and deliver public services, the complexity of interaction among the street-level workers and the detached professional frameworks should be kept in mind.     

The Emergence and Stability of the Attentional Bias to Fearful Faces in Infancy

Several studies have shown that at 7 months of age, infants display an attentional bias toward fearful facial expressions. In this study, we analyzed visual attention and heart rate data from a cross‐sectional study with 5‐, 7‐, 9‐, and 11‐month‐old infants (Experiment 1) and visual attention from a longitudinal study with 5‐ and 7‐month‐old infants (Experiment 2) to examine the emergence and stability of the attentional bias to fearful facial expressions. In both experiments, the attentional bias to fearful faces appeared to emerge between 5 and 7 months of age: 5‐month‐olds did not show a difference in disengaging attention from fearful and nonfearful faces, whereas 7‐ and 9‐month‐old infants had a lower probability of disengaging attention from fearful than nonfearful faces. Across the age groups, heart rate (HR) data (Experiment 1) showed a more pronounced and longer‐lasting HR deceleration to fearful than nonfearful expressions. The results are discussed in relation to the development of the perception and experience of fear and the interaction between emotional and attentional processes.     

The EKC Hypothesis Does Not Hold for Direct Material Flows: Environmental Kuznets Curve Hypothesis Tests for Direct Material Flows in Five Industrial Countries

This study analyses the Environmental Kuznets Curve Hypothesis (EKC) with direct material flow data from the USA, Germany, Japan, the Netherlands and Finland in the years 1975 to 1994. Recently, there has been a discussion concerning the relevance of the EKC hypothesis suggesting that also the intensity of material use should decline with income growth. The EKC hypothesis has not been widely tested with direct material flow data, and this paper presents one of the first attempts to do such tests. The results of the empirical hypothesis tests indicate that the EKC hypothesis does not hold in the case of aggregated direct material flows among industrialised countries like Germany, Japan, the USA, the Netherlands and Finland.