Evidence That Mutation Is Universally Biased towards AT in Bacteria

Mutation is the engine that drives evolution and adaptation forward in that it generates the variation on which natural selection acts. Mutation is a random process that nevertheless occurs according to certain biases. Elucidating mutational biases and the way they vary across species and within genomes is crucial to understanding evolution and adaptation. Here we demonstrate that clonal pathogens that evolve under severely relaxed selection are uniquely suitable for studying mutational biases in bacteria. We estimate mutational patterns using sequence datasets from five such clonal pathogens belonging to four diverse bacterial clades that span most of the range of genomic nucleotide content. We demonstrate that across different types of sites and in all four clades mutation is consistently biased towards AT. This is true even in clades that have high genomic GC content. In all studied cases the mutational bias towards AT is primarily due to the high rate of C/G to T/A transitions. These results suggest that bacterial mutational biases are far less variable than previously thought. They further demonstrate that variation in nucleotide content cannot stem entirely from variation in mutational biases and that natural selection and/or a natural selection-like process such as biased gene conversion strongly affect nucleotide content

Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes

Intima media thickness as a predictor of atherosclerosis in renal transplantation

Joint Meeting of the Turkish-Transplantation-Society and Eurotransplant -- JUN 25-27, 2003 -- ANKARA, TURKEYWOS: 000188758100047PubMed ID: 15013331It has been reported that an increase in carotid artery intima-media thickness (IMT), a sign of early atherosclerosis, has a predictive value for future cardiovascular (CV) events. There are limited data about IMT measurements in renal transplant patients who display a high rate of CV mortality. In this study carotid artery IMT was measured by high resolution B-mode ultrasonography in 102 randomly selected RT patients to assess the relationship between IMT and CV disease and risk factors. A positive correlation was found between IMT and age, triglyceride level, and hematocrit. IMT was significantly higher among patients who were diabetic (0.68 +/- 0.27 vs 0.50 +/- 0.2) or had CV disease (0.88 +/- 0.28 vs 0.53 +/- 0.21). An increased IMT was associated with a longer duration of ESRD, higher lipid level, lower serum albumin, and presence of previous CMV disease. CV disease was more frequent among patients with increased IMT. Considering its relation to CV risk factors, it is concluded that the measurement of carotid artery IMT is an easy, reliable and non-invasive method to be used to assess atherosclerotic disease in renal transplant patients.Turkish Transplantat Soc, Eurotransplan

The transfer and implementation of an Aboriginal Australian wellbeing program: a grounded theory study

Background: The concepts and standard practices of implementation, largely originating in developed countries, cannot necessarily be simply transferred into diverse cultural contexts. There has been relative inattention in the implementation science literature paid to the implementation of interventions targeting minority Indigenous populations within developed countries. This suggests that the implementation literature may be bypassing population groups within developed countries who suffer some of the greatest disadvantage. Within the context of Aboriginal Australian health improvement, this study considers the impact of political and cultural issues by examining the transfer and implementation of the Family Wellbeing program across 56 places over a 20-year period.\ud \ud Methods: A theoretical model of program transfer was developed using constructivist-grounded theory methods. Data were generated by conducting in-depth interviews with 18 Aboriginal and non-Aboriginal research respondents who had been active in transferring the program. Data were categorised into higher order abstract concepts and the core impetus for and process of program transfer were identified.\ud \ud Results: Organizations transferred the program by using it as a vehicle for supporting inside-out empowerment. The impetus to support inside-out empowerment referred to support for Aboriginal people's participation, responsibility for and control of their own affairs, and the associated ripple effects to family members, organizations, communities, and ultimately reconciliation with Australian society at large. Program transfer occurred through a multi-levelled process of embracing relatedness which included relatedness with self, others, and structural conditions; all three were necessary at both individual and organizational levels.\ud \ud Conclusions: Similar to international implementation models, the model of supporting inside-out empowerment by embracing relatedness involved individuals, organizations, and interpersonal and inter-organizational networks. However, the model suggests that for minority Indigenous populations within developed countries, implementation approaches may require greater attention to the empowering nature of the intervention and its implementation, and multiple levels of relatedness by individuals and organizations with self, others, and the structural conditions. Key elements of the theoretical model provide a useful blueprint to inform the transfer of other empowerment programs to minority Indigenous and other disadvantaged populations on a case-by-case basis