Management and Organization Review Special Issue "Social Networks The Dark and Bright Sides of Informal Networks'

Research on the mechanisms of organizing and managing via interpersonal relations has a rich history in the management and organization-oriented literature. So far, however, the informal dimension of managing and organizing by drawing on informal networks in an international context has received comparably less attention. Recent research has pointed out that social capital and network theories have largely been developed by Western scholars based on circumstances and social structures that are typical of Western societies. Thus, current theory takes into account to a lesser extent their character and nature and the way in which informal ties and networks are formed in other parts of the world (Ledeneva, 2018; Li, 2007b; Qi, 2013; Sato, 2010). Besides the growing body of literature concerned with informal ties and networks in emerging and transitioning countries, for example guanxi (China), blat/svyazi (Russia), and wasta (Arab World), a trend for analyzing pervasive informal networks in advanced and industrialized economies, such as yongo (Korea), has arisen. While insights from the latter research stream indicate that informal networks persist, the results generated in both research streams will help in developing the extant informal network theories further

The Effect of Mindfulness-based Programs on Cognitive Function in Adults: A Systematic Review and Meta-analysis

Mindfulness-based programs (MBPs) are increasingly utilized to improve mental health. Interest in the putative effects of MBPs on cognitive function is also growing. This is the first meta-analysis of objective cognitive outcomes across multiple domains from randomized MBP studies of adults. Seven databases were systematically searched to January 2020. Fifty-six unique studies (n = 2,931) were included, of which 45 (n = 2,238) were synthesized using robust variance estimation meta-analysis. Meta-regression and subgroup analyses evaluated moderators. Pooling data across cognitive domains, the summary effect size for all studies favored MBPs over comparators and was small in magnitude (g = 0.15; [0.05, 0.24]). Across subgroup analyses of individual cognitive domains/subdomains, MBPs outperformed comparators for executive function (g = 0.15; [0.02, 0.27]) and working memory outcomes (g = 0.23; [0.11, 0.36]) only. Subgroup analyses identified significant effects for studies of non-clinical samples, as well as for adults aged over 60. Across all studies, MBPs outperformed inactive, but not active comparators. Limitations include the primarily unclear within-study risk of bias (only a minority of studies were considered low risk), and that statistical constraints rendered some p-values unreliable. Together, results partially corroborate the hypothesized link between mindfulness practices and cognitive performance. This review was registered with PROSPERO [CRD42018100904]

Water Microbiology. Bacterial Pathogens and Water

Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water—cholera, typhoid fever and bacillary dysentery—is presented, focusing on the biology and ecology of the causal agents and on the diseases’ characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment) and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers). Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters

Le volcanisme de la péninsule Byers (”le Livingston, Shetland du Sud, Antarctique): Apports des isotopes du Sr, du Nd et du Pb

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1992-2017: 25 years of success story on Minor Actinides Partitioning Processes Development

International audienceIn the frame of the successive 1991 and 2006 Waste Management Acts, French government supported a very significant RetD program on partitioning and transmutation of minor actinides (MA) in fast reactors. This program aimed to study potential solutions for still minimizing the quantity and the hazardousness of final waste, by MA recycling. Indeed, MA recycling can reduce the heat load and the radiotoxicity of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste. Over the 20 years of development, different types of strategies were studied, from the early multi-stage DIAMEX-SANEX processes to the most recent innovative SANEX, from the grouped extraction of MA thanks to the GANEX process to the most recent sole Americium recycling thanks to the EXAm process. These developments were supported by a robust and long-standing approach allowing successively to screen the potential extractants, to quantify their extractive properties and develop relevant chemical models to simulate it and to address their hydrolysis and radiolysis resistance. Finally, all these processes were qualified on a few kg of spent nuclear fuel within the Atalante CBP facility. This wide research program allows France to get a flexible portfolio of MA recycling processes that could be implemented after industrial upscaling. More recently, CEA initiated a demonstration experiment, the so-called integral experiment, which aims to re-irradiate in a Material Testing Reactor some fuel pellets manufactured from recycled UAm. Most recent results on these key experiments will be presented. Finally, several European Research Projects were funded in parallel by the European Commission and allow studying alternative separation processes. A general overview of these 20 years of successful and innovative research history will be synthesized in this presentation

French Perspective On The Respective Interests Of Hydro- And Pyro-Chemical Processes For Recycling Future Spent Nuclear Fuels

International audienceFor more than 25 years, France has operated the treatment and recycling of spent nuclear fuels at an industrial scale in the AREVA La Hague and MELOX plants. This industrial success story has been based on the historical PUREX separation process which allows the U and Pu separation from the fission products and minor actinides thanks to their selective extraction by the TriButylPhosphate non-miscible molecules. Beyond the initial PUREX process, more innovative processes have been developed and tested at representative scale, such as (U,Pu) co-management separation process or different minor actinides enhanced partitioning processes. Liquid/liquid extraction processes hence demonstrated their suitability both to be industrially deployed and to be upgraded and extended towards additional recycling objectives for oxides fuels. In the same time, pyrochemical processes have been developed since the early 60's for recycling of the metallic fuels. Later on, this process was implemented at the pilot scale for recovering uranium from sodium bonded metallic fuel of the EBR2 reactors. Laboratory scale processes have also been developed for recovering the plutonium and the minor actinides by using a reactive cadmium cathode. More recently, Korea developed such type of processes at the engineering scale, on surrogate materials. The long term aim is to recycle current commercial spent nuclear fuels.Furthermore, most of the future 4th generation nuclear systems plan to expand the actinides recycling, for allowing a better use of natural uranium. Uranium-238 efficient consumption would hence be possible thanks to the Pu-multirecycling in fast neutrons reactors. Recycling would therefore be the core of future nuclear energy systems with a strong requirement of efficiency and safety. From the current situation, two main routes seem to be envisaged for recycling future commercial spent nuclear fuels, pyro- or hydro-processes. This paper aims to depict the respective values of both types of processes for future fuel cycles and assess what could be their most relevant potential targets