Managing the Urban Commons

All communities have common resources that are vulnerable to selfish motives. The current paper explores this challenge in the specific case of the urban commons, defined as the public spaces and scenery of city neighborhoods. A theoretical model differentiates between individual incentives and social incentives for caring for the commons. The quality of a commons is defined as the level of physical (e.g., loose garbage) and social (e.g., public disturbances) disorder. A first study compared levels of disorder across the census block groups of a single city; the second compared the disorder generated by individual addresses in two neighborhoods. Each study found that homeownership, an individual incentive, was the main predictor of disorder. Owner-occupied parcels generated less disorder than their renter-occupied neighbors, but both parcel types produced less disorder in a neighborhood with greater homeownership. The results emphasize the need for considering both individual and social incentives for group-beneficial behaviors.     

Spreading of silent chromatin: inaction at a distance

One of the oldest unsolved problems in genetics is the observation that gene silencing can 'spread' along a chromosome. Although spreading has been widely perceived as a process of long-range assembly of heterochromatin proteins, such 'oozing' might not apply in most cases. Rather, long-range silencing seems to be a dynamic process, involving local diffusion of histone-modifying enzymes from source binding sites to low-affinity sites nearby. Discontinuous silencing might reflect looping interactions, whereas the spreading of continuous silencing might be driven by the processive movement of RNA or DNA polymerases. We review the evidence for the spreading of silencing in many contexts and organisms and conclude that multiple mechanisms have evolved that silence genes at a distance.     

Missing inaction: the dangers of ignoring missing data

The most common approach to dealing with missing data is to delete cases containing missing observations. However, this approach reduces statistical power and increases estimation bias. A recent study shows how estimates of heritability and selection can be biased when the 'invisible fraction' (missing data due to mortality) is ignored, thus demonstrating the dangers of neglecting missing data in ecology and evolution. We highlight recent advances in the procedures of handling missing data and their relevance and applicability.     

The Emergence of New Commons

The emergence of ??new commons?? poses theoretical challenges that require empirical efforts and in-depth case studies. Three years of ethnographic work at an Ecuadorian coastal community brings us to propose the emergence of a new commons, historically born from an unstructured group of inhabitants, and refunded as a community seemingly able to convert a degraded socio-ecological system into a more sustainable configuration. To understand this process, we study how institutions and rules developed for the environmental management of strategic common pool resources (CPRs), transforming human?Cenvironment relationships. This socio-ecosystem constitutes a co-managed multi-level system of governance, developed through a community building process and a particular community based tourism model. Its analysis suggests that the balanced development of different levels of management with a firm base at the community level bringing into play new CPRs, can be key factors for the emergence of new commons.     

生命伦理学委员会

生命伦理学委员会是从伦理学角度审查人体试验研究,保护受试者权益的决策咨询组织。该委员会一般由来自法学、伦理学、医学、药学等领域的专家学者组成,其审查遵循的重要依据是世界医学会制订的《赫尔基辛宣言》。近年来,伦理委员会快速发展,但各伦理委员会审查质量参差不齐。因此,相关部门尚需加强对伦理委员会成员的培训,并加强对伦理委员会的监管,方能促进我国伦理委员会的良性发展。     

Executive committee

Executive Committee Aquatic Ecosystem Health & Management Society

Executive committee