Genome diversity at the serA-linked capsule locus in Escherichia coli

Individual isolates of Escherichia coli synthesize one of more than 70 chemically distinct polysaccharides which form the capsule. In this article we review the genetics of capsule production in E. coli and highlight what this is beginning to reveal in terms of the genetic basis of the structural diversity of polysaccharides. The serA-linked capsule locus can take three different allelic forms. Two of these are associated with capsule genes and are themselves internally variant, whilst the third form has not so far been implicated in capsule biogenesis. Thus the serA-linked region of the E. coli genome is strikingly polymorphic.     

Lessons from the Ebola Outbreak: Action Items for Emerging Infectious Disease Preparedness and Response

EcoHealth - As the Ebola outbreak in West Africa wanes, it is time for the international scientific community to reflect on how to improve the detection of and coordinated response to future...     

Late Glacial and Early Holocene human demographic responses to climatic and environmental change in Atlantic Iberia

Successive generations of hunter–gatherers of the Late Glacial and Early Holocene in Iberia had to contend with rapidly changing environments and climatic conditions. This constrained their economic resources and capacity for demographic growth. The Atlantic façade of Iberia was occupied throughout these times and witnessed very significant environmental transformations. Archaeology offers a perspective on how past human population ecologies changed in response to this scenario. Archaeological radiocarbon data are used here to reconstruct demographics of the region over the long term. We introduce various quantitative methods that allow us to develop palaeodemographic and spatio-temporal models of population growth and density, and compare our results to independent records of palaeoenvironmental and palaeodietary change, and growth rates derived from skeletal data. Our results demonstrate that late glacial population growth was stifled by the Younger Dryas stadial, but populations grew in size and density during the Early to Middle Holocene transition. This growth was fuelled in part by an increased dependence on marine and estuarine food sources, demonstrating how the environment was linked to demographic change via the resource base, and ultimately the carrying capacity of the environment.This article is part of the theme issue ‘Cross-disciplinary approaches to prehistoric demography’.     

A transfer function approach to measuring cell inheritance

Background  

The inheritance of cellular material between parent and daughter cells during mitosis is highly influential in defining the properties of the cell and therefore the population lineage. This is of particular relevance when studying cell population evolution to assess the impact of a disease or the perturbation due to a drug treatment. The usual technique to investigate inheritance is to use time-lapse microscopy with an appropriate biological marker, however, this is time consuming and the number of inheritance events captured are too low to be statistically meaningful.     

The wild bird trade and African parrots: past,present and future challenges

African parrots are among the most traded of all birds listed on the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Collapses in some wild populations due to trapping for the pet trade have highlighted the threats posed by overexploitation. Although over 3.3 million African parrots have been reported in trade since 1975, virtually no monitoring of exploited populations has taken place and basic ecological data do not exist for the majority of traded species. Greater scrutiny of the wild bird trade in Africa would help ensure the practice is compatible with conservation goals as well as minimise biosecurity risks, including the spread of infectious diseases and the establishment of invasive populations.