3,248 research outputs found
Social Support and Attitudes to Aging in Later Life
Negative attitudes to aging are a risk factor for poor health and well-being. The current study sought to examine satisfaction with social support as a potentially modifiable factor that might facilitate the development of more positive attitudes to aging. A convenience sample of 501 older respondents (Mage = 72.06) reported on frequency of social support and their satisfaction with it, as well as completing a rating of attachment (model of the self and others), a measure of attitudes to aging, and a number of background measures. Results indicated that better subjective health, younger age, and greater satisfaction with social support were all significant predictors of more positive attitudes to aging, while frequency of social support was not. Model of the self accounted for some variation in satisfaction with social support. Interventions to increase satisfaction with social support in later life, recognizing individual differences and attachment styles, may improve attitudes to aging, and further support health and well-being.Data collection for this study was supported by the ESRC grant (RES-000-22-4117) awarded to S.M. Nelis (PI), L. Clare and C.J. Whitaker. We also acknowledge the support of the ESRC and NIHR through grant ES/L001853/1 âImproving the experience of dementia and enhancing active life: living well with dementiaâ (Investigators: L. Clare, I.R. Jones, C.Victor, J.V. Hindle, R.W.Jones, M.Knapp, M.Kopelman, A.Martyr, F.Matthews, R.G.Morris, S.M.Nelis, J.Pickett, C.Quinn, J.Rusted, N.Savitch, J.Thom)
The adsorption structure of furan on Pd(1 1 1)
The structure of molecular furan, C4H4O, on Pd(1 1 1) has been investigated by O K-edge near-edge X-ray absorption fine structure (NEXAFS) and C 1s scanned-energy mode photoelectron diffraction (PhD). NEXAFS shows the molecule to be adsorbed with the molecular plane close to parallel to the surface, a conclusion confirmed by the PhD analysis. Chemical-state specific C 1s PhD data were obtained for the two inequivalent C atoms in the furan, the α-C atoms adjacent to the O atom, and the ÎČ-C atoms bonded only to C atoms, but only the PhD modulations for the α-C emitters were of sufficiently large amplitude for detailed evaluation using multiple scattering calculations. This analysis shows the α-C atoms to be located approximately 0.6 Ă
off-atop surface Pd atoms with an associated CâPd bondlength of 2.13 ± 0.03 Ă
. Two alternative local geometries consistent with the data place the O atom in off-atop or near-hollow locations, and for each of these local structures there are two equally-possible registries relative to the fcc and hcp hollow sites. The results are in good agreement with earlier density functional theory calculations which indicate that the fcc and hcp registries are equally probable, but the PhD results fail to distinguish the two distinct local bonding geometries
A structural study of a C3H3 species coadsorbed with CO on Pd(1 1 1)
The combination of chemical-state-specific C 1s scanned-energy mode photoelectron diffraction (PhD) and O K-edge near-edge X-ray absorption fine structure (NEXAFS) has been used to determine the local adsorption geometry of the coadsorbed C3H3 and CO species formed on Pd(1 1 1) by dissociation of molecular furan. CO is found to adopt the same geometry as in the Pd(1 1 1)c(4 Ă 2)-CO phase, occupying the two inequivalent three-fold coordinated hollow sites with the CâO axis perpendicular to the surface. C3H3 is found to lie with its molecular plane almost parallel to the surface, most probably with the two âouterâ C atoms in equivalent off-atop sites, although the PhD analysis formally fails to distinguish between two distinct local adsorption sites
A photoelectron diffraction investigation of vanadyl phthalocyanine on Au(1 1 1)
Scanned-energy mode photoelectron diffraction using the O 1s and V 2p emission perpendicular to the surface has been used to investigate the orientation and internal conformation of vanadyl phthalocyanine (VOPc) adsorbed on Au(1 1 1). The results confirm earlier indications from scanning tunnelling microscopy that the Vdouble bond; length as m-dashO vanadyl bond points out of, and not into, the surface. The Vdouble bond; length as m-dashO bondlength is 1.60 ± 0.04 Ă
, not significantly different from its value in bulk crystalline VOPc. However, the V atom in the adsorbed molecule is almost coplanar with the surrounding N atoms and is thus pulled down into the approximately planar region defined by the N and C atoms by 0.52 (+0.14/â0.10) Ă
, relative to its location in crystalline VOPc. This change must be attributed to the bonding interaction between the molecule and the underlying metal surface
Adsorption structure of glycine on TiO2(1 1 0): a photoelectron diffraction determination
High-resolution core-level photoemission and scanned-energy mode photoelectron diffraction (PhD) of the O 1s and N 1s states have been used to investigate the interaction of glycine with the rutile TiO2(1 1 0) surface. Whilst there is clear evidence for the presence of the zwitterion View the MathML sourceCH2COOâ with multilayer deposition, at low coverage only the deprotonated glycinate species, NH2CH2COO is present. Multiple-scattering simulations of the O 1s PhD data show the glycinate is bonded to the surface through the two carboxylate O atoms which occupy near-atop sites above the five-fold-coordinated surface Ti atoms, with a TiâO bondlength of 2.12 ± 0.06 Ă
. Atomic hydrogen arising from the deprotonation is coadsorbed to form hydroxyl species at the bridging oxygen sites with an associated TiâO bondlength of 2.01 ± 0.03 Ă
. Absence of any significant PhD modulations of the N 1s emission is consistent with the amino N atom not being involved in the surface bonding, unlike the case of glycinate on Cu(1 1 0) and Cu(1 0 0)
Characterization of Polar Stratospheric Clouds With Spaceborne Lidar: CALIPSO and the 2006 Antarctic Season
The role of polar stratospheric clouds in polar ozone loss has been well documented. The CALIPSO satellite mission offers a new opportunity to characterize PSCs on spatial and temporal scales previously unavailable. A PSC detection algorithm based on a single wavelength threshold approach has been developed for CALIPSO. The method appears to accurately detect PSCs of all opacities, including tenuous clouds, with a very low rate of false positives and few missed clouds. We applied the algorithm to CALIPSO data acquired during the 2006 Antarctic winter season from 13 June through 31 October. The spatial and temporal distribution of CALIPSO PSC observations is illustrated with weekly maps of PSC occurrence. The evolution of the 2006 PSC season is depicted by time series of daily PSC frequency as a function of altitude. Comparisons with virtual solar occultation data indicate that CALIPSO provides a different view of the PSC season than attained with previous solar occultation satellites. Measurement-based time series of PSC areal coverage and vertically-integrated PSC volume are computed from the CALIPSO data. The observed area covered with PSCs is significantly smaller than would be inferred from a temperature-based proxy such as TNAT but is similar in magnitude to that inferred from TSTS. The potential of CALIPSO measurements for investigating PSC microphysics is illustrated using combinations of lidar backscatter coefficient and volume depolarization to infer composition for two CALIPSO PSC scenes
The local adsorption structure of benzene on Si(001)-(2 Ă 1): a photoelectron diffraction investigation
Scanned-energy mode C 1s photoelectron diffraction has been used to investigate the local adsorption geometry of benzene on Si(001) at saturation coverage and room temperature. The results show that two different local bonding geometries coexist, namely the 'standard butterfly' (SB) and 'tilted bridge' (TB) forms, with a composition of 58 ± 29% of the SB species. Detailed structural parameter values are presented for both species including SiâC bond lengths. On the basis of published measurements of the rate of conversion of the SB to the TB form on this surface, we estimate that the timescale of our experiment is sufficient for achieving equilibrium, and in this case our results indicate that the difference in the Gibbs free energy of adsorption, ÎG(TB)âÎG(SB), is in the range â0.023 to +0.049 eV. We suggest, however, that the relative concentration of the two species may also be influenced by a combination of steric effects influencing the kinetics, and a sensitivity of the adsorption energies of the adsorbed SB and TB forms to the nature of the surrounding benzene molecules
Photoelectron diffraction investigation of the structure of the clean TiO2(110)(1Ă1) surface
The surface relaxations of the rutile TiO2(110)(1Ă1) clean surface have been determined by O 1 s and Ti 2p3â2 scanned-energy mode photoelectron diffraction. The results are in excellent agreement with recent low-energy electron diffraction (LEED) and medium energy ion scattering (MEIS) results, but in conflict with the results of some earlier investigations including one by surface x-ray diffraction. In particular, the bridging O atoms at the surface are found to relax outward, rather than inward, relative to the underlying bulk. Combined with the recent LEED and MEIS results, a consistent picture of the structure of this surface is provided. While the results of the most recent theoretical total-energy calculations are qualitatively consistent with this experimental consensus, significant quantitative differences remain
Recent Results on Strangeness Production at RHIC
Due to its large acceptance, the STAR experiment has acquired a wealth of
data on strangeness production for a variety of collisions systems and
energies, from p+p to Au+Au. By using the yields and spectra, we address the
evolution of the bulk system, including strangeness enhancement and the flavour
dependence of radial and elliptic flow. Utilising the fact that we can identify
strange baryons and mesons, we investigate different hadronization mechanisms
in the intermediate and high p regions. The ratios of the particle
yields, measured to high p, are used to further investigate the range and
applicability of the previously reported anomalous baryon production. We also
study two-particle azimuthal correlations of identified particles in order to
investigate any flavour dependence of jet fragmentation in the available
p range. Data was presented for a number of different collision systems
and energies.Comment: Proceedings of SQM'06 Conference, LA, 2006 (submitted to J. Phys. G
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