Interactions among biotic and abiotic controls of carbon dynamics in a global change field experiment

Climate warming and increased atmospheric nitrogen deposition may substantially influence biosphere C cycling over the next century by altering ecosystem processes such as productivity and decomposition. Field studies are commonly used to explore plant responses to global change, although the underlying mechanisms can be difficult to isolate owing to the lack of control of factors such as plant-animal interactions. Ultimately, indirect effects via herbivore and detritivore responses may feedback to influence plant responses to the experimental treatments. The goal of this thesis was to explore interactions among biotic and abiotic drivers of carbon dynamics within the context of experimental warming and nitrogen addition in the field. Evidence from a herbivore exclusion experiment revealed that mollusc effects on net primary productivity were more pronounced in warmed plots than in ambient temperature plots, likely as a result of temperature-related increases in mollusc metabolic activity and plant consumption rate. Furthermore, the effects of rodent exclusion on grass biomass were significantly greater in N-fertilized plots than non-fertilized plots. Feeding experiments suggested that this finding is likely attributed to increased grass palatability in response to N addition. Results from a litter decomposition experiment indicated that warming impeded the contribution of detritivores to carbon turnover, though this effect was transient. Increased precipitation over the course of the experiment may have promoted recovery of the detritivore community, and could also account for the significant detritivore effects observed following one year of incubation. Reciprocal litter transplants between the treatments plots and untreated areas of the field indicated that the observed responses from the main experiment were unlikely to be accounted for by the individual effects of litter quality or microenvironment alone. Overall, the influence of global change factors such as warming and increased atmospheric nitrogen deposition on carbon-related processes such as productivity can be substantially modified by indirect effects on herbivore dynamics, with consumer-specific treatment effects suggesting that this relationship is complex and can depend on both diet quality and microclimate. Though detritivores were relatively insensitive to warming and N addition as decomposition progressed, they likely play an important role in the overall magnitude of ecosystem C turnover

Metabolism and transactivation activity of 13,14-dihydroretinoic acid

Journal ArticleThe metabolism of vitamin A is a highly regulated process that generates essential mediators involved in the development, cellular differentiation, immunity, and vision of vertebrates. Retinol saturase converts all-trans-retinol to all-trans-13,14-dihydroretinol (Moise, A. R., Kuksa, V., Imanishi, Y., and Palczewski, K. (2004) J. Biol. Chem. 279, 50230-50242). Here we demonstrate that the enzymes involved in oxidation of retinol to retinoic acid and then to oxidized retinoic acid metabolites are also involved in the synthesis and oxidation of all-trans-13,14-dihydroretinoic acid. All-trans-13,14-dihydroretinoic acid can activate retinoic acid receptor/retinoid X receptor heterodimers but not retinoid X receptor homodimers in reporter cell assays. All-trans-13,14-dihydroretinoic acid was detected in vivo in Lrat-/- mice supplemented with retinyl palmitate. Thus, all-trans-13,14-dihydroretinoic acid is a naturally occurring retinoid and a potential ligand for nuclear receptors. This new metabolite can also be an intermediate in a retinol degradation pathway or it can serve as a precursor for the synthesis of bioactive 13,14-dihydroretinoid metabolites

Endothelial dysfunction in adolescents and young adults with nonalcoholic liver disease

Nonalcoholic liver disease is a global public health problem that increases cardiovascular morbidity and mortality in these patients. This paper discusses endothelial dysfunction among patients (adolescents and young adults) with nonalcoholic liver disease. On the one hand, evidence suggests that cardiovascular disease is the leading cause of mortality in patients with advanced nonalcoholic liver disease and that nonalcoholic fatty liver is associated with an increased risk of cardiovascular disease independent of the presence of cardiovascular risk factors and metabolic syndrome components. On the other hand, nonalcoholic liver disease, especially the non-inflammatory form of nonalcoholic steatohepatitis, may not only be a marker of cardiovascular damage but also a factor involved in its pathogenesis. Such patients are candidates not only for the treatment of liver disease but also for the early treatment of cardiovascular risk factors because many of them, especially those with severe nonalcoholic liver disease, will develop major cardiovascular events and may eventually die of cardiovascular disease before the advanced liver disease occurs

Diaspora diplomacy and modes of engagement: the case of Romanian Diaspora in the UK

Purpose The current study aims to map the existent modes of engagement used by both individual and organisational actors of Romanian diaspora community in the UK to build public legitimacy and social value in the host society. This study focuses on two main questions: (1) What are the forms of engagement by which diaspora members enact their role as diplomats for ethnic diaspora communities? (2) What is the nature of their communication practices that sustain these forms of diasporic engagement? Design/methodology/approach This study is based on an analysis of online public documents extracted from different websites, blogs and public social media accounts, complemented by primary data. The research design is a multi-levelled case study. Findings The main findings are that Romanian diaspora in the UK develops a specific model of diplomacy, focused on cultural and political forms of engagement. Firstly, equality and belonging are two key dimensions that clearly define this diasporic community diplomatic actions and practices. Secondly, the communication that fosters its networked and associative features has shifted towards a more democratic and strategic model. Originality/value This paper has multiple original points. Firstly, it deepens the understanding of diaspora diplomacy, connecting the concept with strategic communication. Secondly, the identification and theorisation of specific forms of engagement of diasporic communities reflects a process which is yet underdeveloped in both types of literature. Findings may be instrumental in providing strategies for relationship building, cultivation and the engagement efforts of the UK institutions regarding immigrant integration

The Deliberative Nature of London’s Civic and Democratic Participation Sector. The Uses of Lived Experiences in the Advocacy NGO’s Rhetoric The Deliberative Nature of London’s Civic and Democratic Participation Sector. The Uses of Lived Experiences in the Advocacy NGO’s Rhetoric

Starting from an applied research project and its findings, we develop a broader discussion about the uses of lived experiences highlighted through applied research in the advocacy NGO’s rhetoric. As emphasised by many scholars having researched rhetoric and political communication, lived experiences of marginalised community members are being increasingly included in the organisational communication that aims to foster civic and democratic participation. Having actively collaborated as an external consultant for a research project funded by the Trust for London, on behalf of the Citizenship and Integration Initiative, and the UK Democracy Fund, a Joseph Rowntree Reform Trust initiative, we explore the role of applied research projects as mediums of lived experiences in public deliberations around civic and democratic participation.

The Social Value of Public Relations in the Romanian Book Sector

The aim of the present article is to identify the social and cultural value of Public Relations in the Romanian book sector. Our approach overpasses the functionalist perspective of Public Relations as an organizational discipline and considers Public Relations as a discipline that institutionalizes relationships and discourses that are commonly practiced in the society by mutual and tacit agreement. We investigate the current communication practices used by three Romanian publishing houses in order to generate and to increase the symbolic value of the book. In order to analyze the uses and practices of Public Relations of generating literary sociability at the level of Romanian society, we analysed the communication management through owned new media (websites, blogs, Facebook) that three of the publishing houses in Romania have developed since their foundation. We analyzed the conversational competency in the online environment, using a complex methodology: starting from three Romanian publishing houses, selected on the basis of dimension, financial capacity and consumer perception of reputation, we have analyzed the content produced on the main owned-media channels used for public communication (websites, blogs, social media pages and accounts – Facebook, Twitter) between June – October 2014. We also analyzed the quality of interaction, by taking into account the number of positive reactions to a post, the number of replies and the number of comments

MECHANISTIC ASPECTS OF CAROTENOID BIOSYNTHESIS

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Reviews, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/cr400106

Coupled model simulations of current Australian surface climate and its changes under greenhouse warming: an analysis of 18 CMIP2 models

Coupled climate models have been extensively used to further our understanding of the dynamics and physics of the Earth's climate system and the potential changes of regional and global climates in the future, especially due to human activities such as fossil fuel burning and land-use activities. Nevertheless, there are still large uncertainties in our knowledge of the global climate system and in our representations of such a complex system. The confidence of our projected future climate change, therefore, inevitably depends on how well the current climate is simulated by coupled climate models and how large the scatter is among the model simulations of current and future climates. As one of the diagnostic subprojects within the Coupled Model Intercomparison Project phase II (CMIP2), we present an evaluation of 18 CMIP2 coupled model simulations over the Australian region.Monthly rainfall and surface air temperature climatologies over the Australian region have been derived from the 18 CMIP2 control simulations and compared with observations from the Australian Bureau of Meteorology. The gross spatial patterns of austral summer rainfall (DJF) are reasonably simulated by the majority of the models. However, there are significant model errors in simulating the intensity and location of the heavy Australian monsoon rainfall in the north and eastern parts of the continent, with about half of the models showing more than 100 mm/month biases and a number of models simulating wrong locations of the monsoon rainfall. The seasonal cycle of the surface temperature is reasonably reproduced in the models although there are biases of around 2-4 degrees C present in the model simulated surface air temperature climatology.Based on the 80-year model simulations of perturbed climate, with 1% per year increase of atmospheric CO2 concentration, the changes of surface air temperature and precipitation have also been analysed. The average annual surface temperature change in the last 20-year period of the model simulations against the model control simulations over the Australian region varies from 1.00 degrees C to 2.18 degrees C, with an ensemble average of 1.59 degrees C and 0.33 degrees C scatter measured by one standard deviation. The models give a mixed signal in predicting averaged Australian rainfall changes, with some models simulating more than 3 mm/month increase while others show more than 4 mm/month decrease with on average no change. The spatial distributions of the model-simulated surface temperature and precipitation changes have also been analysed. Surface temperature is increased over the whole continent in all models, while the changes in precipitation show large spatial variations. The ensemble mean model shows decreases in winter rainfall across southern Australia and over northwestern Australia during summer. Increased rainfall is simulated over parts of eastern Australia during winter, extending further north during summer. Besides the analysis of changes in mean climate, the potential impacts of global warming on Australian climate variability is explored in a preliminary way by analysing the changes in tropical Australian precipitation correlations with surface temperature variations over four key oceanic regions. Results suggest that the influence of tropical and subtropical sea-surface temperature (SST) forcing on the Australian climate may change under greenhouse warmin