Reduction of the Clavicles in the Mesoenatidae, with Some Remarks Concerning the Relationship of the Clavicle to Flight-Function in Birds

Author Institution: Blue Sea Lake Biological Laboratory, Messines, Quebec, and Division of Birds, U. S. National Museum, Washington, D. C

Constructing ordinary places: Place-making in urban informal settlements in Mexico

Observers from a variety of disciplines agree that informal settlements account for the majority of housing in many cities of the global South. Urban informal settlements, usually defined by certain criteria such as self-build housing, sub-standard services, and residents’ low incomes, are often seen as problematic, due to associations with poverty, irregularity and marginalisation. In particular, despite years of research and policy, gaps in urban theory and limited understandings of urban informal settlements mean that they are often treated as outside ‘normal’ urban considerations, with material effects for residents including discrimination, eviction and displacement. In response to these considerations, this article uses a place-making approach to explore the spatial, social and cultural construction of place in this context, in order to unsettle some of the assumptions underlying discursive constructions of informal settlements, and how these relate to spatial and social marginalisation. Research was carried out using a qualitative, ethnographic methodology in two case study neighbourhoods in Xalapa, Mexico. Mexico offers fertile ground to explore these issues. Despite an extensive land tenure regularisation programme, at least 60 per cent of urban dwellers live in colonias populares, neighbourhoods with informal characteristics. The research found that local discourses reveal complex and ambivalent views of colonias populares, which both reproduce and undermine marginalising tendencies relating to ‘informality’. A focus on residents’ own place-making activities hints at prospects for rethinking urban informal settlements. By capturing the messy, dynamic and contextualised processes that construct urban informal settlements as places, the analytical lens of place-making offers a view of the multiple influences which frame them. Informed by perspectives from critical social geography which seek to capture the ‘ordinary’ nature of cities, this article suggests imagining urban informal settlements differently, in order to re-evaluate their potential contribution to the city as a whole

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

A new race of the crested eagle-hawk, Spizaetus ornatus

Volume: 25Start Page: 450End Page: 45

The parasitic habit in the ducks, a theoretical consideration

Volume: 80Start Page: 1End Page: