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Growing length scales in aging systems  [PDF]
Federico Corberi,Leticia F. Cugliandolo,Hajime Yoshino
Physics , 2010,
Abstract: We summarize studies of growing lengths in different aging systems. The article is structured as follows. We recall the definition of a number of observables, typically correlations and susceptibilities, that give access to dynamic and static correlation lengths. We use a growing length perspective to review three out of equilibrium cases: domain growth phenomena; the evolution of Edwards-Wilkinson and Kardar-Parisi-Zhang manifolds and other directed elastic manifolds in random media; spin and structural glasses in relaxation and under an external drive. Finally, we briefly report on a mechanism for dynamic fluctuations in aging systems that is based on a time-reparametrization invariance scenario and may be at the origin of the dynamic growing length in glassy materials.
Emergence of Clusters in Growing Networks with Aging  [PDF]
Nuno Crokidakis,Marcio Argollo de Menezes
Statistics , 2009, DOI: 10.1088/1742-5468/2009/04/P04018
Abstract: We study numerically a model of nonequilibrium networks where nodes and links are added at each time step with aging of nodes and connectivity- and age-dependent attachment of links. By varying the effects of age in the attachment probability we find, with numerical simulations and scaling arguments, that a giant cluster emerges at a first-order critical point and that the problem is in the universality class of one dimensional percolation. This transition is followed by a change in the giant cluster's topology from tree-like to quasi-linear, as inferred from measurements of the average shortest-path length, which scales logarithmically with system size in one phase and linearly in the other.
Growing number of pensioners and population aging in Serbia  [PDF]
Stojilkovi? Jelena
Journal of the Geographical Institute Jovan Cvijic, SASA , 2011, DOI: 10.2298/ijgi1102069s
Abstract: The aim of this paper is to shed more light on population aging by using indicators such as years of service and average years in retirement, since the most benefits from the Fund for Pension and Disability Insurance are paid for elderly. As a method for better understanding the structure of pensioners, we used the data on years one spends as employee before gaining pension benefits, so we could get better information about previous activity of retirees, but also to emphasize legal issues that have increased the number of early retirement recipients. Many countries do not allow early retirement, so the limitation of minimum years required for the early retirement is necessary for reduction of pension spending. Another important characteristic of the financial sustainability of the Fund for Pension and Disability Insurance are the average years in retirement. Given the fact that the life expectancy of the elderly is slightly increasing, it is realistic to expect longer use of pension of old-age and disability pensioners, who are on average younger. Apart from showing the level of financial sustainability of the fund, this indicator shows the characteristics of mortality in the country. Pension Fund data show certain development tendencies that will continue in the future because all processes related to population are long-term, including those related to pensioners that are beside socio-economic, influenced by demographic factors.
Growing length scales during aging in 2d disordered systems  [PDF]
Heiko Rieger,Gregory Schehr,Raja Paul
Physics , 2004, DOI: 10.1143/PTPS.157.111
Abstract: The non-equilibrium dynamics of three paradigmatic models for two-dimensional systems with quenched disorder is studied with a focus on the existence and analysis of a growing length scale during aging at low temperatures: 1) The random bond Ising ferromagnet, 2) the Edwards-Anderson model for a spin glas, 3) the solid-on-solid model on a disordered substrate (equivalent to the sine-Gordon model with random phase shifts). Interestingly, we find in all three models a length scale that grows algebraically with time (up to the system size in cases 1 and 3, up to the finite equilibrium length in case 2) with a temperature dependent growth exponent. Whereas in cases 1 and 2 this length scale characterizes a coarsening process, it represents in case 3 the growing size of fluctuations during aging.
Evidence of growing spatial correlations during the aging of glassy glycerol  [PDF]
C. Brun,F. Ladieu,L'H?te,G. Biroli,Jean-Philippe Bouchaud
Physics , 2012, DOI: 10.1103/PhysRevLett.109.175702
Abstract: We have measured, as a function of the age $t_a$, the aging of the nonlinear dielectric susceptibility $\chi_3$ of glycerol below the glass transition. Whereas the linear susceptibility can be accurately accounted for in terms of an age dependent relaxation time $\tau_{\alpha}(t_a)$, this scaling breaks down for $\chi_3$, suggesting an increase of the amplitude of $\chi_3$. This is a strong indication that the number $N_{corr}$ of molecules involved in relaxation events increases with $t_a$. For $T=0.96 \times T_g$, we find that $N_{corr}$ increases by $\sim 10%$ when $t_a$ varies from $1\mathrm{ks}$ to $100\mathrm{ks}$. This sheds new light on the relation between length scales and time scales in glasses.
Growing correlations and aging of an elastic line in a random potential  [PDF]
José Luis Iguain,Sebastian Bustingorry,Alejandro B. Kolton,Leticia F. Cugliandolo
Physics , 2009, DOI: 10.1103/PhysRevB.80.094201
Abstract: We study the thermally assisted relaxation of a directed elastic line in a two dimensional quenched random potential by solving numerically the Edwards-Wilkinson equation and the Monte Carlo dynamics of a solid-on-solid lattice model. We show that the aging dynamics is governed by a growing correlation length displaying two regimes: an initial thermally dominated power-law growth which crosses over, at a static temperature-dependent correlation length $L_T \sim T^3$, to a logarithmic growth consistent with an algebraic growth of barriers. We present a scaling arguments to deal with the crossover-induced geometrical and dynamical effects. This analysis allows to explain why the results of most numerical studies so far have been described with effective power-laws and also permits to determine the observed anomalous temperature-dependence of the characteristic growth exponents. We argue that a similar mechanism should be at work in other disordered systems. We generalize the Family-Vicsek stationary scaling law to describe the roughness by incorporating the waiting-time dependence or age of the initial configuration. The analysis of the two-time linear response and correlation functions shows that a well-defined effective temperature exists in the power-law regime. Finally, we discuss the relevance of our results for the slow dynamics of vortex glasses in High-Tc superconductors.
Falls among elderly persons in Latin America and the Caribbean and among elderly Mexican-Americans
Reyes-Ortiz,Carlos A.; Al Snih,Soham; Markides,Kyriakos S.;
Revista Panamericana de Salud Pública , 2005, DOI: 10.1590/S1020-49892005000500008
Abstract: objective: to estimate the prevalence of and risk factors for falls among community-dwelling elders in latin america and the caribbean and among elderly mexican-americans in the southwestern united states. methods: data for the study came from a project called health, well-being, and aging in latin america and the caribbean (salud, bienestar y envejecimiento en américa latina y el caribe) (the "sabe project") (surveys from seven cities, with a total of 9 765 subjects) and from the hispanic established populations for epidemiologic studies of the elderly (h-epese) (1 483 subjects). results: the overall prevalence of falls across the seven sabe cities and the h-epese ranged from 21.6% in bridgetown, barbados, to 34.0% in santiago, chile. in multiple logistic regression analyses, female gender, increased age, high depressive symptoms, and having any functional limitations were significant independent risk factors for falls in most of the cities studied as well as among the elderly mexican-americans. in several of the cities, significant risk factors also included diabetes, urinary incontinence, and arthritis. conclusions: the prevalence of falls had a large variation among the countries studied. some of the risk factors that we identified could be modified so as to help prevent falls in older people in these populations. the factors deserving attention include depressive symptoms, functional limitations, diabetes, and urinary incontinence.
Key focal areas for bridging the fields of aging and disability: findings from the growing older with a disability conference
Vishaya Naidoo,Michelle Putnam,Andria Spindel
International Journal of Integrated Care , 2012,
Abstract: Based upon research presented at the 2011 Festival of International Conferences on Caregiving, Disability, Aging and Technology (FICCDAT)-and specifically the Growing Older with a Disability (GOWD) conference, this paper identifies areas where bridging building between aging and disability is needed to support older adults aging into or with disabilities. Five focal areas emerged: 1) The Need to Forward Bridging Between Aging and Disability Sectors, 2) Theoretical Frameworks of Individual Aging that Facilitate Bridging, 3) Bridging through Consumer Participation and Involvement, 4) Bridging Through Knowledge Transfer and 5) Bridging Opportunities in Long-Term Supports and Services and Assistive Technologies. Discussion of themes is provided within both international and Canadian contexts, reflecting the interests of FICCDAT and GOWD organizers in discussing how to improve bridging in Canada. Findings from this report form the basis of the Toronto Declaration on Bridging Aging and Disability Policy, Practice, and Research.
The conflict triad dynamical system  [PDF]
Volodymyr Koshmanenko,Igor Samoilenko
Mathematics , 2010, DOI: 10.1016/j.cnsns.2010.10.028
Abstract: A dynamical model of the natural conflict triad is investigated. The conflict interacting substances of the triad are: some biological population, a living resource, and a negative factor (e.g., infection diseases). We suppose that each substance is multi-component. The main coexistence phases for substances are established: the equilibrium point (stable state), the local cyclic orbits (attractors), the global periodic oscillating trajectories, and the evolution close to chaotic. The bifurcation points and obvious thresholds between phases are exhibited in the computer simulations.
The birds of the Augrabiese Falls National Park
J. M. Winterbottom
Koedoe : African Protected Area Conservation and Science , 1970, DOI: 10.4102/koedoe.v13i1.739
Abstract: The birds of the Augrabiese Falls National Park
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