Regularization of Linear Ill-posed Problems by the Augmented Lagrangian Method and Variational Inequalities

We study the application of the Augmented Lagrangian Method to the solution of linear ill-posed problems. Previously, linear convergence rates with respect to the Bregman distance have been derived under the classical assumption of a standard source condition. Using the method of variational inequalities, we extend these results in this paper to convergence rates of lower order, both for the case of an a priori parameter choice and an a posteriori choice based on Morozov's discrepancy principle. In addition, our approach allows the derivation of convergence rates with respect to distance measures different from the Bregman distance. As a particular application, we consider sparsity promoting regularization, where we derive a range of convergence rates with respect to the norm under the assumption of restricted injectivity in conjunction with generalized source conditions of H\"older type

An in situ intercomparison exercise on passive samplers for the monitoring of metals, polycyclic aromatic hydrocarbons and pesticides in surface water

An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 for the measurement of selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at 2 rivers sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant outputs from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and its uncertainties, the representativity of DGT samples, the ability of PSs to lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compounds (PRC) approach for POCIS with pesticides. These in situ intercomparison exercises should enable to progress on the harmonization of practices for the use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD)

All Politics is Local: The Renminbi's Prospects as a Future Global Currency

Recent years have seen a heated discussion over Chinese capital account liberalization and internationalization of China’s currency, the renminbi (RMB). Against the backdrop of a weak U.S. economy and China’s growing international economic clout, there has been speculation about the RMB replacing the U.S. dollar as the world’s leading currency. Subramanian (2011: 1), for instance, maintains that “the renminbi could become the premier reserve currency by the end of this decade, or early next decade.” Much of the current discourse recalls past discussions when other currencies, especially the Japanese yen (Burstein 1988; Kwan 1994; Taguchi 1994) and the Euro (Chinn and Frankel 2007), were seen as candidates to “dethrone” the dollar

Les cultures vivrières associées aux arbustes natifs : un modèle adapté au climat sahélien

Basé sur des cas d'étude au Sénégal, ce chapitre dresse le bilan de 15 années de recherches sur le fonctionnement des sols d'agrosystèmes associant plantes cultivées (milarachide) et arbustes natifs au Sahel. Les travaux, publiés pour la plupart, ont montré que Guiera senegalensis et Piliostigma reticulatum redistribuent l'eau dans le sol, stimulent les microorganismes du sol et génèrent des îlots de fertilité au bénéfice de la culture associée. Ainsi, les rendements des cultures sont augmentés, y compris en absence de fertilisants : jusqu'à +137 % pour le mil en présence de P. reticulatum à Nioro-du-Rip. Cela justifie l'intérêt de maintenir ces arbustes dans les champs en appliquant une gestion agroécologique

The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation

Abstract Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation

PIRCHE-II Is Related to Graft Failure after Kidney Transplantation

Individual HLA mismatches may differentially impact graft survival after kidney transplantation. Therefore, there is a need for a reliable tool to define permissible HLA mismatches in kidney transplantation. We previously demonstrated that donor-derived Predicted Indirectly ReCognizable HLA Epitopes presented by recipient HLA class II (PIRCHE-II) play a role in de novo donor-specific HLA antibodies formation after kidney transplantation. In the present Dutch multi-center study, we evaluated the possible association between PIRCHE-II and kidney graft failure in 2,918 donor–recipient couples that were transplanted between 1995 and 2005. For these donors–recipients couples, PIRCHE-II numbers were related to graft survival in univariate and multivariable analyses. Adjusted for confounders, the natural logarithm of PIRCHE-II was associated with a higher risk for graft failure [hazard ratio (HR): 1.13, 95% CI: 1.04–1.23, p = 0.003]. When analyzing a subgroup of patients who had their first transplantation, the HR of graft failure for ln(PIRCHE-II) was higher compared with the overall cohort (HR: 1.22, 95% CI: 1.10–1.34, p < 0.001). PIRCHE-II demonstrated both early and late effects on graft failure in this subgroup. These data suggest that the PIRCHE-II may impact graft survival after kidney transplantation. Inclusion of PIRCHE-II in donor-selection criteria may eventually lead to an improved kidney graft survival

Bifurcated homeland and diaspora politics in China and Taiwan towards the Overseas Chinese in Southeast Asia

The conventional literature on diaspora politics tends to focus on one ‘homeland’ state and its relations with ‘sojourning’ diaspora around the world. This paper examines an instance of ‘bifurcated homeland:’ the People's Republic of China and the Republic of China (Taiwan) since 1949. The paper investigates the changing dynamics of China's and Taiwan's diaspora policies towards Overseas Chinese communities in Southeast Asia throughout the Cold War and post-Cold War periods. They were affected by their ideological competition, the rise of Chinese nationalism, and the ‘indigenisation’ of Taiwanese identity. Illustrating such changes through the case of the KMT Yunnanese communities in Northern Thailand, this paper makes two interrelated arguments. First, we should understand relations through the lens of interactive dynamics between international system-level changes and domestic political transformations. Depending on different normative underpinnings of the international system, the foundations of regime legitimacy have changed. Subsequently, the nature of relations between the diaspora and the homeland(s) transformed from one that emphasises ideological differences during the Cold War, to one infused with nationalist authenticity in the post-Cold War period. Second, the bifurcated nature of the two homelands also created mutual influences on their diaspora policies during periods of intense competition

Biochar: pyrogenic carbon for agricultural use: a critical review.

O biocarvão (biomassa carbonizada para uso agrícola) tem sido usado como condicionador do solo em todo o mundo, e essa tecnologia é de especial interesse para o Brasil, uma vez que tanto a ?inspiração?, que veio das Terras Pretas de Índios da Amazônia, como o fato de o Brasil ser o maior produtor mundial de carvão vegetal, com a geração de importante quantidade de resíduos na forma de finos de carvão e diversas biomassas residuais, principalmente da agroindústria, como bagaço de cana, resíduos das indústrias de madeira, papel e celulose, biocombustíveis, lodo de esgoto etc. Na última década, diversos estudos com biocarvão têm sido realizados e atualmente uma vasta literatura e excelentes revisões estão disponíveis. Objetivou-se aqui não fazer uma revisão bibliográfica exaustiva, mas sim uma revisão crítica para apontar alguns destaques na pesquisa sobre biochar. Para isso, foram selecionados alguns temaschave considerados críticos e relevantes e fez-se um ?condensado? da literatura pertinente, mais para orientar as pesquisas e tendências do que um mero olhar para o passad

PS14 Lessons from the rise and fall of Chinese peer-to-peer lending

This paper reviews the development and assesses the future of peer-to-peer (P2P) lending in China. Chinese P2P lending has expanded by a factor of 60 over the 4 years from 2013 to 2017. Consequently, it is now much greater, both in absolute terms and relative to the size of the economy, than in any other country. The industry though has been plagued by problematic often fraudulent business models in what was, until 2015, effectively a regulatory vacuum. A strict new regulatory regime is currently being introduced. However, the introduction of the strict new regulatory regime, especially the requirements on capital and registration are substantially reducing the volume of P2P lending. We consider the future of P2P lending concluding it is facing substantial uncertainties