Hunger Artists: Yeast Adapted to Carbon Limitation Show Trade-Offs under Carbon Sufficiency

As organisms adaptively evolve to a new environment, selection results in the improvement of certain traits, bringing about an increase in fitness. Trade-offs may result from this process if function in other traits is reduced in alternative environments either by the adaptive mutations themselves or by the accumulation of neutral mutations elsewhere in the genome. Though the cost of adaptation has long been a fundamental premise in evolutionary biology, the existence of and molecular basis for trade-offs in alternative environments are not well-established. Here, we show that yeast evolved under aerobic glucose limitation show surprisingly few trade-offs when cultured in other carbon-limited environments, under either aerobic or anaerobic conditions. However, while adaptive clones consistently outperform their common ancestor under carbon limiting conditions, in some cases they perform less well than their ancestor in aerobic, carbon-rich environments, indicating that trade-offs can appear when resources are non-limiting. To more deeply understand how adaptation to one condition affects performance in others, we determined steady-state transcript abundance of adaptive clones grown under diverse conditions and performed whole-genome sequencing to identify mutations that distinguish them from one another and from their common ancestor. We identified mutations in genes involved in glucose sensing, signaling, and transport, which, when considered in the context of the expression data, help explain their adaptation to carbon poor environments. However, different sets of mutations in each independently evolved clone indicate that multiple mutational paths lead to the adaptive phenotype. We conclude that yeasts that evolve high fitness under one resource-limiting condition also become more fit under other resource-limiting conditions, but may pay a fitness cost when those same resources are abundant

ICAR: endoscopic skull‐base surgery

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The 2010 Hans Cloos lecture : the contribution of urban geology to the development, regeneration and conservation of cities

Urban geology began to develop in the 1950s, particularly in California in relation to land-use planning, and led to Robert Legget publishing his seminal book “Cities and geology” in 1973. Urban geology has now become an important part of engineering geology. Research and practice has seen the evolution from single theme spatial datasets to multi-theme and multi-dimensional outputs for a wide range of users. In parallel to the development of these new outputs to aid urban development, regeneration and conservation, has been the growing recognition that city authorities need access to extensive databases of geo-information that are maintained in the long-term and renewed regularly. A further key advance has been the recognition that, in the urban environment, knowledge and understanding of the geology need to be integrated with those of other environmental topics (for example, biodiversity) and, increasingly, with the research of social scientists, economists and others. Despite these advances, it is suggested that the value of urban geology is not fully recognised by those charged with the management and improvement of the world’s cities. This may be because engineering geologists have failed to adequately demonstrate the benefits of urban geological applications in terms of cost and environmental improvement, have not communicated these benefits well enough and have not clearly shown the long-term contribution of geo-information to urban sustainability. Within this context future actions to improve the situation are proposed

Factors associated with intergenerational social support across the world

There has been increasing interest among social scientists with regard to the role of socioeconomic, demographic, and cultural situations on intergenerational finance and help and care transfers in society. With the rapid pace of socioeconomic development and both populations and societies generally being in transition in many parts of the world, traditional values and family dynamics are being affected. Although some researchers have attempted to explore the changing pattern of intergenerational transfers for specific geographical locations, there has been no global comparison yet made due to either an inadequate data set or complete lack of it. Utilising the 2007 Global Ageing Survey (GLAS), this study attempts to examine important determinants of financial transfers as well as help and care transfers among individuals aged between 40 and 79 years residing across 21 countries and territories in five major regions of the world. In the present study, it has been found that a respondent’s age, gender, household size, health appraisal, education, employment status, marital status, contact between generations and geographical location are key factors affecting the receipt or provision of financial support as well as help and care support. Analyses have been performed at regional and country levels providing robust and reliable estimates. This enables us to reach more effective conclusions on populations overall as well as on specific geographical settings. Some policy recommendations and future research directions are put forward in the last part of this paper