Physical mechanisms and scaling laws of K-shell double photoionization

We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed

Double K-shell photoionization of low-Z atoms and He-like ions

We report on the investigation of the photon energy dependence of double 1s photoionization of light atoms and compare the cross sections for hollow atom and He-like ion production. Measurements of the Kα hypersatellite x-ray spectra of Mg, Al, and Si were carried out using the Fribourg high-resolution x-ray spectrometer installed at the ID21 and ID26 beam lines at the ESRF. The double-to-single photoionization cross section ratios were derived as a function of the incident photon beam energy and compared to convergent close-coupling (CCC) calculations for He-like ions. The dynamical electron-electron scattering contribution to the DPI cross-sections was found to be more important for neutral atoms than for the He isoelectronic serie

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FAUNE ET FLORE DES NIVEAUX PROFONDS DE SHAHI-TUMP (BALOCHISTAN, PAKISTAN) Premiers résultats

International audienceÀ Shahi-Tump, site fouillé par la Mission archéologique française au Makran (district de Kech-Makran, Balochistan pakistanais), les niveaux les plus anciens appartiennent à un faciès néolithique acéramique. Pourtant, les premiers résultats des analyses des restes archéozoologiques et archéobotaniques indiquent une séquence culturelle qui correspond à la phase ultime précédant l'introduction de la céramique dans cette région occidentale du Balochistan. L'exploitation du milieu naturel y est de faible importance et l'économie alimentaire repose fondamentalement sur des espèces animales et végétales domestiques-mais dont le spectre est encore limité. Un tel modèle est rare dans la vaste région comprise entre l'Iran oriental et l'Indus. Le seul site ayant livré des faunes et des fl ores domestiquées associées à des niveaux sans céramique est le site de Merhgarh. Ce dernier appartient cependant à une zone biogéographique très différente du Makran, et le rôle des animaux sauvages pour l'obtention de protéines d'origine animale y est très important, alors qu'il n'a joué qu'un rôle mineur dans l'économie de Shahi-Tump. La rareté de tels horizons dans toute cette région nous a paru justifi er la diffusion des points originaux concernant l'économie alimentaire de ce site avant la publication d'autres données-tout particulièrement la métrique-qui seront présentées dans le cadre de la future monographie consacrée aux restes de ce gisement. Abstract: At Shahi-Tump, a site excavated by the French Archaeological Mission to Makran (district of Kech-Makran, Baluchistan, Pakistan), the oldest occupational levels belong to an aceramic neolithic horizon. The fi rst results obtained by the analysis of archaeozoological and archaeobotanical remains suggest nevertheless that we deal here with a phase immediately preceding the introduction of ceramics into this western part of Baluchistan. The exploitation of wild resources was of minor importance and the subsistence economy seems to have been mainly based on a limited number of domestic animal and plant species. This model is uncommon in the vast region stretching from eastern Iran to the Indus. The only other site that has provided remains of domestic animals and plants associated with aceramic neolithic levels is Mehrgarh. However, at this site, situated in a quite different biogeographical zone, wild animals constituted a signifi cant part of the diet, while hunting never played an important role in the subsistence economy at Shahi-Tump. The rarity of aceramic deposits across this region justifi es the publication of the fi rst results from Shahi-Tump even though this paper does not contain detailed information, most particularly morphometric data. These will be presented at length in a future monograph dedicated to the site. Mots-clés : Archéozoologie, Archéobotanique, Shahi-Tump, Makran, Néolithique acéramique, Paléo-environnement

Testing cross-lagged relationships between work-related rumination and well-being at work in a three-wave longitudinal study across 1 and 2 years

The aim of this three‐wave longitudinal study conducted among 664 Finnish employees was to examine the cross‐lagged relationships between various work‐related ruminative thoughts (affective rumination, problem‐solving pondering, lack of detachment from work) during off‐job time and employee well‐being (exhaustion, vigour). We tested normal, reversed, and reciprocal temporal relationships across 1 and 2 years using structural equation modelling. The analyses lent most support to the reversed temporal relationships, showing first that high exhaustion predicted low problem‐solving pondering 2 years later and second, that high vigour predicted low affective rumination both 1 and 2 years later. In addition, a normal temporal relationship was supported in one model, indicating that high affective rumination predicted high exhaustion 1 year later. Thus, our study suggests that affective ruminative thoughts, in particular, play a negative role in cross‐lagged relationships. On the basis of our results, occupational health interventions intended to reduce both affective work‐related rumination and exhaustion and to increase vigour at work are desirable.peerReviewe

Protocol for evaluating a workplace intervention within the framework of consultations for suffering at work in French-speaking Switzerland.

Psychosocial suffering involves diverse human, social and economic costs. Some 34.4% of workers in Switzerland report chronic stress related to their jobs. Medical consultations for suffering at work aim to maintain-or renew-patients' abilities to make decisions and act following a diagnosis of psychological suffering related to their work; they also aim to help workers return to their workstations or remain there. Workplace interventions by consulting occupational physicians can go beyond the subjective issues: they can be offered to employees, in anticipation of a return to work when this appears feasible from the outset. To qualitatively evaluate perceptions of workplace interventions and identify their effects by collecting the verbatim statements of employees and their employers. Qualitative single-centre study of workplace interventions conducted by the Consultation Service for Suffering at Work's occupational physicians for patients seen between January 2015 to December 2017. Nineteen workplace interventions took place, out of 184 different consultations. The verbatim statements of employees and their employers will be collected over a variable timeframe, using semi-structured face-to-face interviews. These will then be recorded, transcribed and analysed. Fourteen patients refused the workplace intervention. Their professional path will be collected for comparison and exploratory purposes. This exploratory research project will provide a better understanding of the issues surrounding work-related psychological suffering and of which strategies support patients most effectively

In vivo (13)C MRS in the mouse brain at 14.1 Tesla and metabolic flux quantification under infusion of [1,6-(13)C2]glucose

In vivo (13)C magnetic resonance spectroscopy (MRS) enables the investigation of cerebral metabolic compartmentation while, e.g. infusing (13)C-labeled glucose. Metabolic flux analysis of (13)C turnover previously yielded quantitative information of glutamate and glutamine metabolism in humans and rats, while the application to in vivo mouse brain remains exceedingly challenging. In the present study, (13)C direct detection at 14.1 T provided highly resolved in vivo spectra of the mouse brain while infusing [1,6-(13)C2]glucose for up to 5 h. (13)C incorporation to glutamate and glutamine C4, C3, and C2 and aspartate C3 were detected dynamically and fitted to a two-compartment model: flux estimation of neuron-glial metabolism included tricarboxylic acid cycle (TCA) flux in astrocytes (Vg = 0.16 ± 0.03 µmol/g/min) and neurons (VTCA(n )= 0.56 ± 0.03 µmol/g/min), pyruvate carboxylase activity (VPC = 0.041 ± 0.003 µmol/g/min) and neurotransmission rate (VNT = 0.084 ± 0.008 µmol/g/min), resulting in a cerebral metabolic rate of glucose (CMRglc) of 0.38 ± 0.02 µmol/g/min, in excellent agreement with that determined with concomitant (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG PET).We conclude that modeling of neuron-glial metabolism in vivo is accessible in the mouse brain from (13)C direct detection with an unprecedented spatial resolution under [1,6-(13)C2]glucose infusion

Punica granatum (Pomegranate) juice provides an HIV-1 entry inhibitor and candidate topical microbicide

BACKGROUND: For ≈ 24 years the AIDS pandemic has claimed ≈ 30 million lives, causing ≈ 14,000 new HIV-1 infections daily worldwide in 2003. About 80% of infections occur by heterosexual transmission. In the absence of vaccines, topical microbicides, expected to block virus transmission, offer hope for controlling the pandemic. Antiretroviral chemotherapeutics have decreased AIDS mortality in industrialized countries, but only minimally in developing countries. To prevent an analogous dichotomy, microbicides should be: acceptable; accessible; affordable; and accelerative in transition from development to marketing. Already marketed pharmaceutical excipients or foods, with established safety records and adequate anti-HIV-1 activity, may provide this option. METHODS: Fruit juices were screened for inhibitory activity against HIV-1 IIIB using CD4 and CXCR4 as cell receptors. The best juice was tested for inhibition of: (1) infection by HIV-1 BaL, utilizing CCR5 as the cellular coreceptor; and (2) binding of gp120 IIIB and gp120 BaL, respectively, to CXCR4 and CCR5. To remove most colored juice components, the adsorption of the effective ingredient(s) to dispersible excipients and other foods was investigated. A selected complex was assayed for inhibition of infection by primary HIV-1 isolates. RESULTS: HIV-1 entry inhibitors from pomegranate juice adsorb onto corn starch. The resulting complex blocks virus binding to CD4 and CXCR4/CCR5 and inhibits infection by primary virus clades A to G and group O. CONCLUSION: These results suggest the possibility of producing an anti-HIV-1 microbicide from inexpensive, widely available sources, whose safety has been established throughout centuries, provided that its quality is adequately standardized and monitored

Relativistic nature of a magnetoelectric modulus of Cr_2O_3-crystals: a new 4-dimensional pseudoscalar and its measurement

Earlier, the magnetoelectric effect of chromium sesquioxide Cr_2O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2O_3 crystals or the magnetic field-induced polarization. From the magnetoelectric moduli of Cr_2O_3 we extract a 4-dimensional relativistic invariant pseudoscalar $\widetilde{\alpha}$. It is temperature dependent and of the order of 10^{-4}/Z_0, with Z_0 as vacuum impedance. We show that the new pseudoscalar is odd under parity transformation and odd under time inversion. Moreover, $\widetilde{\alpha}$ is for Cr_2O_3 what Tellegen's gyrator is for two port theory, the axion field for axion electrodynamics, and the PEMC (perfect electromagnetic conductor) for electrical engineering.Comment: Revtex, 36 pages, 9 figures (submitted in low resolution, better quality figures are available from the authors