ORCID Profile
0000-0002-8271-428X
Current Organisation
UNSW Sydney
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Chemical Society (ACS)
Date: 05-08-2009
DOI: 10.1021/CM901644E
Publisher: David Publishing Company
Date: 28-04-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 1999
DOI: 10.1039/A809571J
Publisher: MDPI AG
Date: 23-05-2017
Publisher: SAGE Publications
Date: 12-10-2015
Abstract: This article reviews the existing literature on the association between the socioeconomic status (SES) and the health of the ageing population in the United Kingdom. It has been noted that socioeconomic differentials are more marked across the United Kingdom than they are in other developed countries. Social class gradients are significant in health for working-age people (up to age 65), whereas studies on older populations have so far been limited so as to draw any robust conclusions. In this article, we examine the inequalities through selected SES indicators in order to tease out the effects on health outcomes of the older population. We critically review the physical and mental health indicators of older people in the United Kingdom with regard to their SES differentials. The findings reveal that older people with lower SES are more likely to experience poorer health outcomes (e.g., long-standing illness or increased disability) and have shorter life expectancy compared with those of higher SES. We illustrate how education remains the single most important determinant of health inequality in later life. We suggest that educational level or occupational class allied with material deprivation offer the best combined indicators of SES for studying health inequalities among older people. The findings of this article has profound implications for prioritizing policies to improve the health and well-being of elderly people with lower SES and go offer an evidence base of how to understand and to develop interventions that minimize the inequalities in health in later life in the United Kingdom.
Publisher: Elsevier BV
Date: 03-1994
Publisher: Public Library of Science (PLoS)
Date: 20-12-2018
Publisher: Informa UK Limited
Date: 09-11-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2DT31491F
Abstract: Complementary experimental techniques and ab initio calculations were used to determine the origin and nature of negative thermal expansion (NTE) in the archetype metal-organic framework MOF-5 (Zn(4)O(1,4-benzenedicarboxylate)(3)). The organic linker was probed by inelastic neutron scattering under vacuum and at a gas pressure of 175 bar to distinguish between the pressure and temperature responses of the framework motions, and the local structure of the metal centers was studied by X-ray absorption spectroscopy. Multi-temperature powder- and single-crystal X-ray and neutron diffraction was used to characterize the polymeric nature of the s le and to quantify NTE over the large temperature range 4-400 K. Ab initio calculations complement the experimental data with detailed information on vibrational motions in the framework and their correlations. A uniform and comprehensive picture of NTE in MOF-5 has been drawn, and we provide direct evidence that the main contributor to NTE is translational transverse motion of the aromatic ring, which can be d ened by applying a gas pressure to the s le. The linker motion is highly correlated rather than local in nature. The relative energies of different framework vibrations populated in MOF-5 are suggested by analysis of neutron diffraction data. We note that the lowest-energy motion is a librational motion of the aromatic ring which does not contribute to NTE. The libration is followed by transverse motion of the linker and the carboxylate group. These motions result in unit-cell contraction with increasing temperature.
Publisher: Elsevier BV
Date: 05-1995
Publisher: AIP Publishing
Date: 22-07-1999
DOI: 10.1063/1.479398
Abstract: Three new algorithms are presented for incorporating nonholonomic constraints into molecular dynamics (MD) simulations, along with any additional holonomic constraints. The advantages of these algorithms over the commonly used Gaussian approach are discussed. Of the three algorithms presented, the optimal one can efficiently ensure satisfaction of large numbers of nonholonomic and holonomic constraints at every MD time step, without introducing additional numerical errors in the coordinate or velocity trajectories. Numerical results from MD simulations of Lennard-Jones particles, rigid water molecules, and partially rigid methane molecules are given, illustrating the advantages of this algorithm. In addition, this algorithm is suggested as a more advantageous alternative to velocity scaling, for maintaining fixed temperature during equilibration of constant energy MD simulations.
Publisher: Elsevier
Date: 1995
Publisher: IEEE
Date: 02-2010
Publisher: Wiley
Date: 09-10-2009
Publisher: AIP Publishing
Date: 17-10-2003
DOI: 10.1063/1.1613939
Abstract: The microstructure and properties of suspensions of nonspherical particles are influenced by the specific particle shapes through hydrodynamic interactions, but here traditional numerical approaches of solving the Stokes equations are limited to small systems by computational cost, and often to special particle arrangements by symmetry requirements. On the other hand, the analytical development of a hydrodynamic mobility algorithm for Stokesian dynamics (SD) simulations of rigid nonspherical particles is mathematically involved, must be derived for each distinct particle shape needed, and cannot handle deformable particles. Hence we present algorithms for SD simulations of arbitrary shape particles, rigid or flexible, constructed with appropriate constraints among rigid spherical particles whose hydrodynamic mobility is computable by various available schemes, including ours [J. Chem. Phys. 112, 2548 (2000)]. The optimal algorithm also provides for rigid attachment among particles during simulation, by aggregation for ex le. Its implementation for a system with internal coordinate constraints is tested in simulations of aggregation of spheres and sedimentation of spheroids and chains in bounded and unbounded geometries.
Publisher: AIP Publishing
Date: 02-2000
DOI: 10.1063/1.480894
Abstract: We obtain the many-body hydrodynamic friction and mobility matrices describing the motion in a fluid of N hard-spheres with stick boundary conditions in the presence of a planar hard wall or free surface using (1) a multipole expansion of the hydrodynamic force densities induced on the spheres and (2) an image representation to account for the fluid boundary. The coupled multipole equations may be truncated at any order to give positive definite approximations to the exact friction and mobility matrices. An extension of the Bossis–Brady lubrication correction to the friction matrix is also discussed and included. The resulting method for computing the mobility matrix may be used for the Stokesian or Brownian dynamics simulation of N spheres subject to interparticle and external forces and imposed shear flow. We illustrate the method by performing Stokesian dynamics simulation of particles near a hard wall. The simulations exhibit the rapid convergence of the multipole truncation scheme including lubrication corrections.
Publisher: Wiley
Date: 1995
Publisher: American Chemical Society (ACS)
Date: 19-05-2014
DOI: 10.1021/JP5004402
Publisher: Elsevier BV
Date: 06-1999
Publisher: AIP Publishing
Date: 22-06-2000
DOI: 10.1063/1.481760
Abstract: A Stokesian dynamics constraint algorithm for the irreversible deposition of colloidal particles onto a surface is presented. This algorithm can also be used to simulate a variety of nondeposition phenomena and with any method for computing the hydrodynamic interactions among the particles. In particular, a multipole scheme we recently described for computing the mobility matrix of colloidal particles, with or without the presence of a wall, is used here in conjunction with the new deposition algorithm to perform Stokesian dynamics irreversible deposition simulations on a group of 75 colloidal particles. Deposition simulations are performed with and without the hydrodynamic effect of the wall (substrate) being included in the mobility matrix. The results of the simulations lead to important qualitative conclusions on the effect of hydrodynamic interactions on the deposition process, in particular the hydrodynamic effect of the wall. In addition, the simulations serve to illustrate the performance of the new deposition algorithm.
Publisher: Wiley
Date: 25-02-1995
Publisher: American Chemical Society (ACS)
Date: 22-02-2012
DOI: 10.1021/JP210212Q
Abstract: We analyze the interplay between proton transfer in the hydrogen-bond bridge, O···H···O, and lattice dynamics in the model system tetraacetylethane (TAE) (CH(3)CO)(2)CH═CH(COCH(3))(2) using density functional theory. Lattice dynamics calculations and molecular dynamics simulations are validated against neutron scattering data. Hindrance to the cooperative reorientation of neighboring methyl groups at low temperatures gives a preferred O atom for the bridging proton. The litude of methyl torsions becomes larger with increasing temperature, so that the free-energy minimum for the proton becomes flat over 0.2 Å. For the isolated molecule, however, we show an almost temperature-independent symmetric double-well potential persists. This difference arises from the much higher barriers to methyl torsion in the crystal that make the region of torsional phase space that is most crucial for symmetrization poorly accessible. Consequently, the proton-transfer potential remains asymmetric though flat at the base, even at room temperature in the solid.
Publisher: American Chemical Society (ACS)
Date: 06-02-2012
DOI: 10.1021/JA211517H
Publisher: Wiley
Date: 1998
Publisher: Elsevier BV
Date: 1996
Publisher: AIP Publishing
Date: 07-05-2010
DOI: 10.1063/1.3358330
Abstract: We describe an algorithm for performing Stokesian dynamics (SD) simulations of suspensions of arbitrary shape rigid particles with hydrodynamic interactions, modeled as rigid groups of spheres, the hydrodynamic mobility matrix of which is accurately computable by several established schemes for spheres. The algorithm is based on Stokesian rigid body equations of translational and rotational motion, which we have derived by an approach formally analogous to that of Newtonian rigid body dynamics. Particle orientation is represented in terms of Euler parameters (quaternion of rotation). This rigid body SD algorithm (RBSDA) complements recently described constraint SD algorithms [R. Kutteh, J. Chem. Phys. 119, 9280 (2003) R. Kutteh, Phys. Rev. E 69, 011406 (2004)], over which it offers the same computational advantages in imposing total rigidity that the basic rigid body molecular dynamics (MD) algorithm offers over constraint MD algorithms. We show that SD simulation results generated with the RBSDA, in bounded and unbounded geometries, agree very well with those from experiment and other SD and non-SD methods, and are numerically identical to those from a constraint SD algorithm, HSHAKE. Finally, for completeness we also describe a third (additional to the constraint SD and rigid body SD approaches) more traditional approach for SD simulations of arbitrary shape rigid particles modeled as rigid groups of spheres.
Publisher: Springer Science and Business Media LLC
Date: 24-10-2019
DOI: 10.1186/S12877-019-1291-Z
Abstract: Over two-thirds of older Australians use different types/levels of aged care at some point in later life. Our aims were to estimate transitional probabilities and to identify risk factors influencing the movement between different levels of long-term care. The s le consisted of 9007 women from the 1921-26 birth cohort of the Australian Longitudinal Study on Women’s Health. Transitional probabilities between different levels of long-term care were estimated using a continuous-time Markov model. An 11-fold transition rates ratio was observed for the movement from non-user to home and community care (HACC) versus non-user to residential aged care (RAC). The predicted probabilities of remaining in the non-user state, HACC, and RAC after 10 years from the baseline were .28, .24, and .11, respectively. While the corresponding probabilities of dying from these states were .36, .65, and .90. The risk of transitioning from the non-user state to either HACC or RAC was greater for participants who were older at baseline, widowed, living outside of major cities, having difficulties in managing income, or having chronic condition, poor/fair self-rated health, or lower SF-36 scores ( p .05). Women spend a substantial period of their later life using long-term care. Typically, this will be in the community setting with a low level of care. The transition to either HACC or RAC was associated with several demographic and health-related factors. Our findings are important for the planning and improvement of long-term care among future generations of older people. Not applicable.
Publisher: Wiley
Date: 14-12-2013
DOI: 10.1111/JACE.12725
Publisher: Oxford University Press (OUP)
Date: 06-2012
DOI: 10.1093/IJE/DYS089
Abstract: Chakaria Health and Demographic Surveillance System (CHDSS), located on the south-eastern coast of the Bay of Bengal, was established in 1999 and is one of the field sites of International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDRB). The surveillance covers 118 315 residents living in 19 847 households. Data on socio-demographic and health indicators including birth, death, migration, marriage, maternal health, education and employment are recorded through quarterly household visits. The primary objective of CHDSS is to monitor the changes in socio-demographic indicators, inequalities in health and impact of public health interventions. A demographic change was accompanied by a shift from traditional to modern society during the past decade, but inequality in health still persists. The findings from the surveillance are shared regularly among the local and global communities. Data are also available upon request to ICDDRB and INDEPTH for use by researchers and policy makers.
Publisher: American Physical Society (APS)
Date: 05-1993
Publisher: American Physical Society (APS)
Date: 30-01-2004
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.PUHE.2018.01.015
Abstract: This study examined the inequality in cesarean section (CS) utilization and its socio-economic contributors. Retrospective two-stage stratified s le design. Data were extracted from two rounds of the Bangladesh Demographic and Health Survey conducted in 2004 and 2014. Concentration Index of CS utilization was calculated using the wealth quintile. Regression-based decomposition method was applied to assess the socio-economic contributors of inequality in CS utilization. The rate of CS utilization increased from 4.98% in 2004 to 24.21% in 2014. The utilization of CS was highly concentrated among the women of higher socio-economic status (SES) in both rounds of the survey. Results of the decomposition models revealed wealth quintile, higher education, higher number of antenatal visits, and being overweight or obese as the critical factors contributing to the inequalities of CS utilization. Bangladesh is now observing a rapid rise in CS utilization and women with higher SES are the main client group of this life saving procedure. There may have inadequate access for those who are relatively less advantaged, even when CS is necessary. Strong initiative from the government is necessary to ensure proper access to this service regardless of women's SES.
Publisher: American Physical Society (APS)
Date: 03-2000
Publisher: Elsevier BV
Date: 07-2016
Publisher: American Chemical Society (ACS)
Date: 18-01-2007
DOI: 10.1021/JP066294D
Publisher: Informa UK Limited
Date: 02-09-2017
Publisher: MDPI AG
Date: 21-08-2017
Publisher: Elsevier BV
Date: 05-1995
Location: Australia
No related grants have been discovered for Ramzi Kutteh.