O₂ Adsorption Dynamics at Metal Surfaces: Non-adiabatic Effects, Dissociation and Dissipation

We review recent progress in the theoretical description of the O2 adsorption dynamics at metal surfaces. Intriguing conceptual challenges to a quantitative modeling arise from the spin triplet ground state of the free oxygen molecule, the typically highly corrugated potential energy surfaces (PESs), and the high exothermicity of dissociative adsorption processes. This dictates extensive dynamical simulations (either through direct ab initio molecular dynamics or PES interpolating divide and conquer approaches), an account of electronic non- adiabaticity, as well as heat dissipation channels. We critically discuss the present status of corresponding methodology and the physical insight gained through it, using the oxygen adsorption at Al(111), Pt(111), Pt(211) and Pd(100) as showcases

Risk factors for type 2 diabetes in women attending menopause clinics in Italy: a cross-sectional study

OBJECTIVE: To analyze risk factors for type 2 diabetes among women attending menopause clinics in Italy for counselling about the menopause. SUBJECTS: Women attending a network of first-level outpatient menopause clinics in Italy for general counselling about menopause or treatment of menopausal symptoms. METHODS: Cross-sectional study with no exclusion criteria. Type 2 diabetes was defined according to National Diabetes Data Groups Indications and the fasting blood glucose at an oral glucose tolerance test within the previous year. RESULTS: Out of the 44 694 considered in this analysis, 808 had a diagnosis of diabetes type 2 (1.8%). In comparison with women aged or = 57 years. Type 2 diabetes was less frequently reported in more educated women (OR high school/university vs. primary school = 0.44 (95% CI, 0.36-0.55)). Being overweight was associated with an increased risk of type 2 diabetes. In comparison with women reporting a low level of physical activity, the multivariate OR of type 2 diabetes was 0.67 (95% CI, 0.54-0.84) for women reporting regular physical activity. In comparison with premenopausal women, the multivariate OR of type 2 diabetes was 1.38 (95% CI, 1.03-1.84) in women with natural menopause. This finding was present also after allowing for the potential confounding effect of age. The multivariate OR of diabetes for users of hormonal replacement therapy was 0.58 (95% CI, 0.46-0.73). CONCLUSIONS: This large cross-sectional study suggests that postmenopausal women are at higher risk of type 2 diabetes after allowance for the effect of age. Other main determinants of risk of type 2 diabetes in women around menopause were low socioeconomic status and being overweight. Diabetes was found less frequently in those taking hormone replacement therapy

One stop shop: backbones trees for important phytopathogenic genera: I (2014)

Many fungi are pathogenic on plants and cause significant damage in agriculture and forestry. They are also part of the natural ecosystem and may play a role in regulating plant numbers/density. Morphological identification and analysis of plant pathogenic fungi, while important, is often hampered by the scarcity of discriminatory taxonomic characters and the endophytic or inconspicuous nature of these fungi. Molecular (DNA sequence) data for plant pathogenic fungi have emerged as key information for diagnostic and classification studies, although hampered in part by non-standard laboratory practices and analytical methods. To facilitate current and future research, this study provides phylogenetic synopses for 25 groups of plant pathogenic fungi in the Ascomycota, Basidiomycota, Mucormycotina (Fungi), and Oomycota, using recent molecular data, up-to-date names, and the latest taxonomic insights. Lineage-specific laboratory protocols together with advice on their application, as well as general observations, are also provided. We hope to maintain updated backbone trees of these fungal lineages over time and to publish them jointly as new data emerge. Researchers of plant pathogenic fungi not covered by the present study are invited to join this future effort. Bipolaris, Botryosphaeriaceae, Botryosphaeria, Botrytis, Choanephora, Colletotrichum, Curvularia, Diaporthe, Diplodia, Dothiorella, Fusarium, Gilbertella, Lasiodiplodia, Mucor, Neofusicoccum, Pestalotiopsis, Phyllosticta, Phytophthora, Puccinia, Pyrenophora, Pythium, Rhizopus, Stagonosporopsis, Ustilago and Verticillium are dealt with in this paper

Long-lived coupled peeling ballooning modes preceding ELMs on JET

In some JET discharges, type-I edge localised modes (ELMs) are preceded by a class of low-frequency oscillations (Perez et al 2004 Nucl. Fusion 44 609). While in many cases the ELM is triggered during the growth phase of this oscillation, it is also observed that this type of oscillation can saturate and last for several tens of ms until an ELM occurs. In order to identify the nature of these modes, a wide pre-ELM oscillation database, including detailed pedestal profile information, has been assembled and analysed in terms of MHD stability parameters. The existence domain of these pre-ELM oscillations and the statistical distribution of toroidal mode numbers (n) up to n = 16 have been mapped in ballooning alpha (alpha(ball)) and either edge current density (J(edge)) or pedestal collisionality (nu(ee,ped)*) coordinates and compared to linear MHD stability predictions. The pre-ELM oscillations are reliably observed when the J/alpha ratio is high enough for the pedestal to access the coupled peeling-ballooning (PB) domain (aka stability nose). Conversely, when the pedestal is found to be in or near the high-n ballooning domain (which is at low J/alpha ratio), ELMs are usually triggered promptly, i.e. with no detectable pre-ELM oscillations, or with pre-ELM oscillations only observable on ECE whose n appears to be too high to be resolved by the magnetics. Individual discharges can sometimes exhibit a fairly wide range of pre-ELM mode numbers, but for a wider database, the statistical n-number domains are found to be well ordered along the J - alpha stability boundary and behave as expected from PB theory: the higher the J/alpha ratio, the lower the mode's measured n tends to be. Within the measurement uncertainties, the measured n is usually found to be compatible with the most unstable n predicted by the linear stability code MISHKA1. These results confirm the earlier hypothesis that these modes are coupled peeling-ballooning modes, and extend and generalise to higher-mode numbers the work by Huysmans et al (1998 Nucl. Fusion 38 179), who identified the lowest n modes as pure external kink modes. Since the destabilisation of PB modes is widely accepted to give rise to ELMs, the mode saturation and delayed ELM triggering that is sometimes observed is rather unexpected. Possibilities to reconcile the extended lifetime of these modes with current ELM models are briefly discussed, but will require further investigation

Diagnostic of fast-ion energy spectra and densities in magnetized plasmas

The measurement of the energy spectra and densities of alpha-particles and other fast ions are part of the ITER measurement requirements, highlighting the importance of energy-resolved energetic-particle measurements for the mission of ITER. However, it has been found in recent years that the velocity-space interrogation regions of the foreseen energetic-particle diagnostics do not allow these measurements directly. We will demonstrate this for gamma-ray spectroscopy (GRS), collective Thomson scattering (CTS), neutron emission spectroscopy and fast-ion D-alpha spectroscopy by invoking energy and momentum conservation in each case, highlighting analogies and differences between the different diagnostic velocity-space sensitivities. Nevertheless, energy spectra and densities can be inferred by velocity-space tomography which we demonstrate using measurements at JET and ASDEX Upgrade. The measured energy spectra agree well with corresponding simulations. At ITER, alpha-particle energy spectra and densities can be inferred for energies larger than 1.7 MeV by velocity-space tomography based on GRS and CTS. Further, assuming isotropy of the alpha-particles in velocity space, their energy spectra and densities can be inferred by 1D inversion of spectral single-detector measurements down to about 300 keV by CTS. The alpha-particle density can also be found by fitting a model to the CTS measurements assuming the alpha-particle distribution to be an isotropic slowing-down distribution

Radial variation of heat transport in L-mode JET discharges

In this paper, we analyze heat transport in the JET tokamak using data from its high resolution ECE diagnostic and analyses based on the transfer entropy (TE). The analysis reveals that heat transport is not smooth and continuous, but is characterized by 'trapping regions' separated by `minor transport barriers'. Meat may 'jump over' these barriers and when the heating power is raised, this 'jumping' behavior becomes more prominent. To check that our results are relevant for global heat transport, we deduced an effective diffusion coefficient from the TE results. Both its value and overall radial variation are consistent with heat diffusivities reported in literature. The detailed radial structure of the effective diffusion coefficient was shown to be linked to the mentioned minor transport barriers

Direct gyrokinetic comparison of pedestal transport in JET with carbon and ITER-like walls

This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). The discharges were selected for a comparison of JET-ILW and JET-C discharges with good confinement at high current (3 MA, corresponding also to low rho(*)) and retain the distinguishing features of JET-C and JET-ILW, notably, decreased pedestal top temperature for JET-ILW. A comparison of the profiles and heating power reveals a stark qualitative difference between the discharges: the JET-ILW pulse (92432) requires twice the heating power, at a gas rate of 1.9 x 10(22) e s(-1), to sustain roughly half the temperature gradient of the JET-C pulse (78697), operated at zero gas rate. This points to heat transport as a central component of the dynamics limiting the JET-ILW pedestal and reinforces the following emerging JET-ILW pedestal transport paradigm, which is proposed for further examination by both theory and experiment. ILW conditions modify the density pedestal in ways that decrease the normalized pedestal density gradient a/L-n, often via an outward shift in relation to the temperature pedestal. This is attributable to some combination of direct metal wall effects and the need for increased fueling to mitigate tungsten contamination. The modification to the density profile increases eta = L-n/L-T, thereby producing more robust ion temperature gradient (ITG) and electron temperature gradient driven instability. The decreased pedestal gradients for JET-ILW (92432) also result in a strongly reduced E x B shear rate, further enhancing the ion scale turbulence. Collectively, these effects limit the pedestal temperature and demand more heating power to achieve good pedestal performance. Our simulations, consistent with basic theoretical arguments, find higher ITG turbulence, stronger stiffness, and higher pedestal transport in the ILW plasma at lower rho(*)