320 research outputs found

    Современные тенденции развития рекреационного хозяйства в Украине

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    Chromiferous ultramafic rocks from Campo Formoso (Bahia State, Brazil) exhibit various stages of hydrothermal alteration and weathering, each being characterized by distinct chromiferous parageneses. These Cr-bearing minerals are mainly phyllosilicates, but other phases are also present as chromiferous opal and hydroxycarbonates. Optical absorption spectra and K-edge fine structure allow a better knowledge of chromium crystal chemistry in these minerals. The first stages of chromite oxidation have been precised, and particularly the influence of structural factors was pointed out : the inversion grade of these spinels controls the evolution from a mainly direct chromite to the inverse forms (ferritchromit). Chromium ions inserted in mineral structures do not exhibit any change in the oxidation state during alteration processes. In contrast, crystal field stabilization energy (CFSE) of Cr3+ ions exhibits important variations among the studied minerals. Study of EXAFS spectra demonstrated that Cr-O distances do not change significandy among the investigated minerals, the effective oxygen charge playing the main role in the observed CFSE variations. This latter parameter explains the concentration of chromium in these minerals and contributes to the stability of some phases like clinochlores and hydroxycarbonates, where trivalent chromium has the highest CFSE.Les ultrabasites chromifères de Campo Formoso (Etat de Bahia, Brésil) montrent plusieurs stades successifs d'altération hydrothermale puis superficielle qui s'accompagnent de paragenèses chromifères variées. Les minéraux caractéristiques de ces dernières sont essentiellement des phyllosilicates, mais on note aussi d'autres phases comme la stichtite et l'opale chromifère. Les spectres d'absorption X ont permis de caractériser la cristallochimie du chrome dans ces minéraux. Les premiers stades d'oxydation des chromites ont été précisés, en particulier l'influence de la structure réelle du spinelle (degré d'inversion) qui contrôle les conditions d'évolution de la chromite. Le degré d'oxydation +3 du chrome est conservé lors des processus d'altération et seule l'énergie de stabilisation liée au champ cristallin montre des changements importants. L'étude des spectres EXAFS (Extended X-ray Absorption Fine Structure) a montré que, les distances Cr-O ne changeant pas entre les minéraux étudiés, seule la nature des ligandes a une influence sur la valeur de l'énergie de champ cristallin. Ceci explique la forte concentration en chrome de ces minéraux d'altération et contribue à la stabilité des phases comme les clinochlores ou les hydroxycarbonates où les ions Cr3+ ont la plus forte énergie de stabilisation.Calas Georges, Manceau Alain, Novikoff André, Boukili Hassan. Comportement du chrome dans les minéraux d'altération du gisement de chromite de Campo Formoso (Bahia, Brésil). In: Bulletin de Minéralogie, volume 107, 6, 1984. pp. 755-766

    On Limitations of the Ultrasonic Characterization of Pieces Manufactured with Highly Attenuating Materials

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    Some technical aspects of two Spanish cooperation projects, funded by DPI and Innpacto Programs of the R&D National Plan, are discussed. The objective is to analyze the common belief about than the ultrasonic testing in MHz range is not a tool utilizable to detect internal flaws in highly attenuating pieces made of coarse-grained steel. In fact high-strength steels, used in some safe industrial infrastructures of energy & transport sectors, are difficult to be inspected using the conventional “state of the art” in ultrasonic technology, due to their internal microstructures are very attenuating and coarse-grained. It is studied if this inspection difficulty could be overcome by finding intense interrogating pulses and advanced signal processing of the acquired echoes. A possible solution would depend on drastically improving signal-to-noise-ratios, by applying new advances on: ultrasonic transduction, HV electronics for intense pulsed driving of the testing probes, and an “ad-hoc” digital processing or focusing of the received noisy signals, in function of each material to be inspected. To attain this challenging aim on robust steel pieces would open the possibility of obtaining improvements in inspecting critical industrial components made of highly attenuating & dispersive materials, as new composites in aeronautic and motorway bridges, or new metallic alloys in nuclear area, where additional testing limitations often appear.The Spanish I+D National Plan (MINECO), by funding the Projects: Fundamental Research / DPI2011 – 22438, and INNPACTO Program / IMAAD - IPT-020000-2010-0004

    X-ray Linear Dichroism in cubic compounds: the case of Cr3+ in MgAl2O4

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    The angular dependence (x-ray linear dichroism) of the Cr K pre-edge in MgAl2O4:Cr3+ spinel is measured by means of x-ray absorption near edge structure spectroscopy (XANES) and compared to calculations based on density functional theory (DFT) and ligand field multiplet theory (LFM). We also present an efficient method, based on symmetry considerations, to compute the dichroism of the cubic crystal starting from the dichroism of a single substitutional site. DFT shows that the electric dipole transitions do not contribute to the features visible in the pre-edge and provides a clear vision of the assignment of the 1s-->3d transitions. However, DFT is unable to reproduce quantitatively the angular dependence of the pre-edge, which is, on the other side, well reproduced by LFM calculations. The most relevant factors determining the dichroism of Cr K pre-edge are identified as the site distortion and 3d-3d electronic repulsion. From this combined DFT, LFM approach is concluded that when the pre-edge features are more intense than 4 % of the edge jump, pure quadrupole transitions cannot explain alone the origin of the pre-edge. Finally, the shape of the dichroic signal is more sensitive than the isotropic spectrum to the trigonal distortion of the substitutional site. This suggests the possibility to obtain quantitative information on site distortion from the x-ray linear dichroism by performing angular dependent measurements on single crystals

    Possible Patient Early Diagnosis by Ultrasonic Noninvasive Estimation of Thermal Gradients into Tissues Based on Spectral Changes Modeling

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    To achieve a precise noninvasive temperature estimation, inside patient tissues, would open promising research fields, because its clinic results would provide early-diagnosis tools. In fact, detecting changes of thermal origin in ultrasonic echo spectra could be useful as an early complementary indicator of infections, inflammations, or cancer. But the effective clinic applications to diagnosis of thermometry ultrasonic techniques, proposed previously, require additional research. Before their implementations with ultrasonic probes and real-time electronic and processing systems, rigorous analyses must be still made over transient echotraces acquired from well-controlled biological and computational phantoms, to improve resolutions and evaluate clinic limitations. It must be based on computing improved signal-processing algorithms emulating tissues responses. Some related parameters in echo-traces reflected by semiregular scattering tissues must be carefully quantified to get a precise processing protocols definition. In this paper, approaches for non-invasive spectral ultrasonic detection are analyzed. Extensions of author's innovations for ultrasonic thermometry are shown and applied to computationally modeled echotraces from scattered biological phantoms, attaining high resolution (better than 0.1°C). Computer methods are provided for viability evaluation of thermal estimation from echoes with distinct noise levels, difficult to be interpreted, and its effectiveness is evaluated as possible diagnosis tool in scattered tissues like liver

    Towards a Performative Understanding of Deservingness: Merit, Gender and the BBC Pay Dispute

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    Drawing largely on a high profile case of unequal pay at the BBC (British Broadcasting Corporation) as an illustrative example, this conceptual paper considers differences and interrelationships between merit and deservingness, where the latter captures how, through appropriate performances, merit is given recognition and value. We propose a performative understanding of deservingness that highlights its gendered and embodied dimensions. Informed by Judith Butler’s account of gender performativity, we show that, while merit is conventionally conceptualized as a relatively fixed set of attributes (qualifications, skill) ‘attached’ to the individual, deservingness captures how, in gendered terms, value and recognition are both claimed and conferred. As we argue, a gendered, deserving subject does not pre-exist but is performatively constituted through embodied practices and performances of what is seen as worthy in a particular time and place

    Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

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    Background Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence. Methods and findings We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries. Conclusions This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.This collaborative project received funding from the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 733206 LifeCycle, Grand Recipient VWVJ; Grant Agreement No. 824989 EUCAN-Connect, Grand Recipient AMNA). Please, see S1 Appendix for list of cohort-specific funding/support. DAL is supported by the UK Medical Research Council (MC_UU_00011/6) and British Heart Foundation (CH/F/20/90003 and AA/18/7/34219). RCW is supported by UKRI Innovation Fellowship with Health Data Research UK [MR/S003959/1]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    RMDAP: A Versatile, Ready-To-Use Toolbox for Multigene Genetic Transformation

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    Background: The use of transgenes to improve complex traits in crops has challenged current genetic transformation technology for multigene transfer. Therefore, a multigene transformation strategy for use in plant molecular biology and plant genetic breeding is thus needed. Methodology/Principal Findings: Here we describe a versatile, ready-to-use multigene genetic transformation method, named the Recombination-assisted Multifunctional DNA Assembly Platform (RMDAP), which combines many of the useful features of existing plant transformation systems. This platform incorporates three widely-used recombination systems, namely, Gateway technology, in vivo Cre/loxP and recombineering into a highly efficient and reliable approach for gene assembly. RMDAP proposes a strategy for gene stacking and contains a wide range of flexible, modular vectors offering a series of functionally validated genetic elements to manipulate transgene overexpression or gene silencing involved in a metabolic pathway. In particular, the ability to construct a multigene marker-free vector is another attractive feature. The built-in flexibility of original vectors has greatly increased the expansibility and applicability of the system. A proof-ofprinciple experiment was confirmed by successfully transferring several heterologous genes into the plant genome. Conclusions/Significance: This platform is a ready-to-use toolbox for full exploitation of the potential for coordinate regulation of metabolic pathways and molecular breeding, and will eventually achieve the aim of what we call ‘‘one-sto

    On the Harmony of Feminist Ethics and Business Ethics

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    If business requires ethical solutions that are viable in the liminal landscape between concepts and corporate office, then business ethics and corporate social responsibility should offer tools that can survive the trek, that flourish in this well-traveled, but often unarticulated, environment. Indeed, feminist ethics produces, accesses, and engages such tools. However, work in BE and CSR consistently conflates feminist ethics and feminine ethics and care ethics. I offer clarification and invoke the analytic power of three feminist ethicists 'in action' whose investigations into the "grey zones" of harms; identity and representational conventions; and "asymmetrical reciprocity" harmonize with business ethics' requirements
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