EXAFS investigation on U(VI) immobilization in hardened cement paste: influence of experimental conditions on speciation

Extended X-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the coordination environment of U(VI) in cementitious materials. The EXAFS measurements were carried out on U(VI)-doped samples prepared under varying conditions, such as samples from sorption, hydration and diffusion experiments, and using different cementitious materials, such as crushed hydrated hardened cement paste (HCP) and calcium silicate hydrates (C-S-H). The samples had U(VI) loadings ranging from 1700μg/g to 45000μg/g. Applying principal component analysis (PCA) on 13 EXAFS spectra (each spectra corresponding to aminimum of five different scans) of the low loading samples, one single species is obtained indicating asimilar U(VI) coordination environment for both HCP and C-S-H samples. This result confirms that C-S-H phases control the uptake of U(VI) in the complex cement matrix. The coordination environment structure of this species is similar to aU(VI) surface complex or to U(VI) in uranyl silicate minerals (two axial O atoms at 1.82±0.02 Å; four equatorial O atoms at 2.25±0.01 Å; one Si atom at 3.10±0.03 Å). At high U(VI) loading, PCA revealed asecond U(VI) species, with acoordination environment similar to that of U(VI) in calcium uranate (two axial O atoms at 1.94±0.04 Å; five equatorial O atoms at 2.26±0.01 Å; four Ca atoms at 3.69±0.05 Å and five U atoms at 3.85±0.04 Å). This study suggest that, at low U(VI) loading, U(VI) is bound to C-S-H phases in HCP while at high U(VI) loading, the immobilization of U(VI) in cementitious materials is mainly controlled by the precipitation of acalcium uranate-type phas

Unified Framework for Development, Deployment and Robust Testing of Neuroimaging Algorithms

Developing both graphical and commandline user interfaces for neuroimaging algorithms requires considerable effort. Neuroimaging algorithms can meet their potential only if they can be easily and frequently used by their intended users. Deployment of a large suite of such algorithms on multiple platforms requires consistency of user interface controls, consistent results across various platforms and thorough testing. We present the design and implementation of a novel object-oriented framework that allows for rapid development of complex image analysis algorithms with many reusable components and the ability to easily add graphical user interface controls. Our framework also allows for simplified yet robust nightly testing of the algorithms to ensure stability and cross platform interoperability. All of the functionality is encapsulated into a software object requiring no separate source code for user interfaces, testing or deployment. This formulation makes our framework ideal for developing novel, stable and easy-to-use algorithms for medical image analysis and computer assisted interventions. The technological The framework has been both deployed at Yale and released for public use in the open source multi-platform image analysis software - BioImage Suite (bioimagesuite.org)

Synthesis of a Se0/Calcite Composite Using Hydrothermal Carbonation of Ca(OH)2 Coupled to a Complex Selenocystine Fragmentation

International audienceElemental selenium (Se0)/calcite composites were synthesized in a batch system by hydrothermal carbonation of calcium hydroxide under high CO2−Ar pressure (90 bar) and high temperature (90 °C) coupled to a complex selenocystine fragmentation. Under O2-poor conditions, the composite consisted predominantly of spherical, amorphous nanoparticles of elemental red selenium (<500 nm) deposited on the calcite matrix. Conversely, under O2-rich conditions, the composite consisted rod-shaped, well-crystallized microparticles of elemental gray selenium (<25 µm) dispersed in the calcite matrix. The carbonate matrix was constituted by nano- to microrhombohedral crystals (<2 µm) and micrometric agglomerates and/or aggregates (<5 µm). Our results present a new synthesis path to Se0/calcite composites, with spherical or rod-shaped Se0 morphology with high potential for medical (e.g., dietary supplement) or industrial (e.g., pigments) applications. Furthermore, this study may have implications in the field of biomineralization

Bi-Annual Report 2007/08 - Rossendorf Beamline at ESRF (ROBL-CRG)

The Rossendorf Beamline (ROBL) - located at BM20 of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France - is in operation since 1998. This 6th report covers the period from January 2007 to December 2008. In these two years, 50 peerreviewed papers have been published based on experiments done at the beamline. The average citation index, which increased constantly over the years, has now reached 3.5 (RCH) and 3.0 (MRH), indicating that papers are predominately published in journals with high impact factors. Six exemplary highlight reports on the following pages should demonstrate the scientific strength and diversity of the experiments performed on the two end-stations of the beamline, dedicated to Radiochemistry (RCH) and Materials Research (MRH). Demand for beamtime remains very high as in the previous years, with an average oversubscription rate of 1.8 for ESRF experiments. The attractiveness of our beamline is based upon the high specialization of its two end-stations. RCH is one of only two stations in Europe dedicated to x-ray absorption spectroscopy of actinides and other radionuclides. The INE beamline at ANKA provides superior experimental flexibility and extends to lower energies, including important elements like P and S. In contrast, ROBL-RCH provides a much higher photon flux, hence lower detection limits crucial for environmental samples, and a higher energy range extending to elements like Sb and I. Therefore, both beamlines are highly complementary, covering different aspects of radiochemistry research. Once the MARS beamline at SOLEIL is ready to run radionuclides (>2010), it will cover a third niche (Materials Science of actinides, including irradiated fuel) not accessible for the two other beamlines. The Materials Research Hutch MRH has realized an increasing number of in-situ investigations in the last years. On the one hand thin film systems were characterized during magnetron sputtering. On the other hand diffraction experiments under controlled atmosphere were performed. A high variety of experimental parameters was covered by varying pressure, temperature and atmospheric compositions including highly reactive gases. Furthermore structural investigations were combined with electrical conductivity measurements. These kind of in-situ experiments are the key to monitor and understand reaction mechanism or the influence of process parameters, which are again the basis to tailor materials properties on demand. The core competences of MRH are these experimental possibilities, which make it unique among other diffraction beamlines. In fall 2007, ROBL was reviewed by an international panel on behalf of the ESRF. The very positive panel report recommended a renewal of the contract between ESRF and FZD for the next five years, and a major upgrade of critical optical components of the beamline to keep ROBL competitive for the next decade. The FZD will provide 2 Mio € from 2009 to 2011 for this upgrade, which will be performed in parallel to the major upgrade of the ESRF to minimize the downtime. According to the current plans of the ESRF, our users have to expect that ROBL will have only limited or no operation for several months from August 2011 on. Since July 2004 the beamline is a member of the pooled facilities of ACTINET – European Network of Excellence. In the reported period, RCH has provided 27 % of its inhouse beamtime to perform 11 ACTINET experiments. The success of ACTINET within FP-6 has now led to a renewal of ACTINET within FP-7, running until end of 2011

Changing face of organised crime or old and new usual suspects

Scheinost, M. Changing face of organised crime or old and new usual suspects / Miroslav Scheinost // Constructing and organising crime in Europe / Petrus C. van Duyne, Alexey Serdyuk, Georgios A. Antonopoulos, Jackie H. Harvey, Klaus von Lampe (Eds.); Kharkiv National University of Internal Affairs, Northumbria University, Teesside University, Utrecht University. – Chicago-Kharkiv : Eleven International Publishing, Kharkiv National University of Internal Affairs, 2019. - P. 235-257. - DOI: https://doi.org/10.32631/ccc19.10.Концепція організованої злочинності в Чеській Республіці зазнала значних змін. Організована злочинність за «старим стилем» з «звичайними підозрюваними» більше не є головною проблемою і основним джерелом занепокоєння в порівнянні з громадською думкою в 1990-х роках. Замість цього загроза організованої злочинності полягає в її економічному і політичному впливі. У зв'язку з цим ми можемо нагадати читачеві про концепцію «хрещеного батька», який завдяки своїм економічним становищем і владі здатний уникати правозастосування та маніпулювати демократичними механізмами, що впливає на формування політики державними органами.The concept of organised crime in the Czech Republic has undergone significant developments. Organised crime ‘old style’ with the ‘usual suspects’ is no longer the top problem and major source of concern, at least in comparison with the public opinion during the 1990s. The threat of organised crime, instead, is found in its economic and political influence. In this regard we may remind the reader of the concept of the ‘godfather’ who due to his economic position and power is able to avoid law enforcement and manipulate democratic mechanisms, thereby affecting policy making by public authorities. The official reports on the security situation do not use the term ‘godfather’ but the threat of the influence of organised crime operating in economic sectors is distinctly articulated.Концепция организованной преступности в Чешской Республике претерпела значительные изменения. Организованная преступность по «старому стилю» с «обычными подозреваемыми» больше не является главной проблемой и основным источником беспокойства, по крайней мере, по сравнению с общественным мнением в 1990-х годах. Вместо этого угроза организованной преступности заключается в ее экономическом и политическом влиянии. В связи с этим мы можем напомнить читателю о концепции «крестного отца», который благодаря своему экономическому положению и власти способен избегать правоприменения и манипулировать демократическими механизмами, что влияет на формирование политики государственными органами

Maternal race-ethnicity, immigrant status, country of birth, and the odds of a child with autism spectrum disorder

The risk of autism spectrum disorder varies by maternal race–ethnicity, immigration status, and birth region. In this retrospective cohort study, Western Australian state registries and a study population of 134 204 mothers enabled us to examine the odds of autism spectrum disorder with intellectual disability in children born from 1994 to 2005 by the aforementioned characteristics. We adjusted for maternal age, parity, socioeconomic status, and birth year. Indigenous women were 50% less likely to have a child with autism spectrum disorder with intellectual disability than Caucasian, nonimmigrant women. Overall, immigrant women were 40% less likely to have a child with autism spectrum disorder with intellectual disability than nonimmigrant women. However, Black women from East Africa had more than 3.5 times the odds of autism spectrum disorder with intellectual disability in their children than Caucasian nonimmigrant women. Research is implicated on risk and protective factors for autism spectrum disorder with intellectual disability in the children of immigrant women

Electron transfer at the mineral/water interface: Selenium reduction by ferrous iron sorbed on clay

International audienceThe mobility and availability of the toxic metalloid selenium in the environment is largely controlled by sorption and redox reactions, which may proceed at temporal scales similar to that of subsurface water movement under saturated or unsaturated conditions. Since such waters are often anaerobic and rich in Fe2+, we investigated the long-term (≤ 1 month) kinetics of selenite (Se(IV)O3 -) sorption to montmorillonite in the presence of Fe2+ under anoxic conditions. A synthetic montmorillonite was used to eliminate the influence of structural Fe. In the absence of aqueous Fe2+, selenite was sorbed as outer-sphere sorption complex, covering only part of the positive edge sites, as verified by a structure-based MUSIC model and Se K-edge XAS (X-ray absorption spectroscopy). When selenite was added to montmorillonite previously equilibrated with Fe2+ solution however, slow reduction of Se and formation of a solid phase was observed with Se K-edge XANES (x-ray absorption near-edge spectroscopy) and EXAFS (extended x-ray absorption finestructure) spectroscopy. Iterative transformation factor analysis of XANES and EXAFS spectra suggested that only one Se reaction product formed, which was identified as nano-particulate Se(0). Even after one month, only 75% of the initially sorbed Se(IV) was reduced to this solid species. Mössbauer spectrometry revealed that before and after addition and reduction of Se, 5% of total sorbed Fe occurred as Fe(III) species on edge sites of montmorillonite (≈ 2 mmol kg-1). The only change observed after addition of Se was the formation of a new Fe(II) species (15%) attributed to the formation of an outer-sphere Fe(II)-Se sorption complex. The combined Mössbauer and XAS results hence clearly suggest that the Se and Fe redox reactions are not directly coupled. Based on the results of a companion paper, we hypothesize that the electrons produced in the absence of Se by oxidation of sorbed Fe(II) are stored, for example by formation of surface H2 species, and are then 3 available for the later Se(IV) reduction. The slow reaction rate indicates a diffusion controlled process. Homogeneous precipitation of an iron selenite was thermodynamically predicted and experimentally observed only in the absence of clay. Interestingly, half of Fe was oxidized in this precipitate (Mössbauer). Since DFT calculations predicted the oxidation of Fe at the water-FeSe solid interface only and not in the bulk phase, the average particle size of this precipitate does not exceed 2 nm. A comparison with the Mössbauer and XAS spectra of the clay samples demonstrates that such homogenous precipitation can be excluded as a mechanism for the observed slow Se reduction, emphasizing the role of abiotic, heterogeneous precipitation and reduction for the removal of Se from subsurface waters

Microbial transformations of selenite by methane-oxidizing bacteria

Abstract Methane oxidizing bacteria are well known for their role in the global methane cycle and their potential for microbial transformation of wide range of hydrocarbon and chlorinated hydrocarbon pollution. Recently, it has also emerged that methane-oxidizing bacteria interact with inorganic pollutants in the environment. Here we report what we believe to be the first study of the interaction of pure strains of methane-oxidizing bacteria with selenite. Results indicate that the commonly used laboratory model strains of methane oxidizing bacteria, Methylococcus capsulatus (Bath) and Methylosinus trichosporium OB3b are both able to reduce the toxic selenite (SeO32-) but not selenate (SeO42-) to red spherical nanoparticulate elemental selenium (Se0), which was characterised via EDX and EXAFS. The cultures also produced volatile selenium-containing species, which suggests that both strains may have an additional activity that can either transform Se0 or selenite into volatile methylated forms of selenium. Transmission electron microscopy (TEM) measurements and experiments with the cell fractions: cytoplasm, cell wall and cell membrane show that the nanoparticles are formed mainly on the cell wall. Collectively these results are promising for the use of methane-oxidizing bacteria for bioremediation or suggest possible uses in the production of selenium nanoparticles for biotechnology

Annual Report 2009/10 Rossendorf Beamline at ESRF (ROBL-CRG)

The Rossendorf Beamline (ROBL) - located at BM20 of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France - is in operation since 1998. This 7th report covers the period from January 2009 to December 2010. In these two years, 67 peer- reviewed papers have been published based on experiments done at the beamline, more than in any biannual period before. Six highlight reports have been selected for this report to demonstrate the scientific strength and diversity of the experiments performed on the two end-stations of the beamline, dedicated to Radiochemistry (RCH) and Materials Research (MRH). The beamtime was more heavily overbooked than ever before, with an acceptance rate of only 25% experiments. We would like to thank our external proposal review members, Prof. Andre Maes (KU Leuven, Belgium), Prof. Laurent Charlet (UJF Grenoble, France), Dr. Andreas Leinweber (MPI Metallforschung, Stuttgart, Germany), Prof. David Rafaja (TU Bergakademie Freiberg, Germany), Prof. Dirk Meyer (TU Dresden, Germany), who evaluated the inhouse proposals in a thorough manner, thereby ensuring that beamtime was distributed according to scientific merit. The period was not only characterized by very successful science, but also by intense work on the optics upgrade. In spring 2009, a workshop was held at ROBL, assembling beamline experts from German, Spanish and Swiss synchrotrons, to evaluate the best setup for the new optics. These suggestions was used to prepare the call for tender published in July 2009. From the tender acceptance in November 2009 on, a series of design review meetings and factory acceptance tests followed. Already in July 2010, the first piece of equipment was delivered, the new double-crystal, double-multilayer monochromator. The disassembly of the old optics components started end of July, 2011, followed by the installation of the new components. As of December 2011, the new optics have seen the first test beam and thorough hot commissioning will be continued until May 2012, since the ESRF shuts down for a major upgrade from December 2011 to April 2012. We expect that we will be ready for user operation from June 2012 on, with a better beamline than ever. The beamline staff would like to thank all partners, research groups and organizations who supported the beamline during the last 24 months. Special thanks to the FZD management, the CRG office of the ESRF with Axel Kaprolat as liaison officer and Eric Dettona as lead technician, and to the ESRF safety group members, Paul Berkvens, Patrick Colomp and Yann Pira