On a functional equation related to the intermediate long wave equation

International Nuclear Information System (INIS)

Hone, A N W; Novikov, V S

2004-01-01

We resolve an open problem stated by Ablowitz et al (1982 J. Phys. A: Math. Gen. 15 781) concerning the integral operator appearing in the intermediate long wave equation. We explain how this is resolved using the perturbative symmetry approach introduced by one of us with Mikhailov. By solving a certain functional equation, we prove that the intermediate long wave equation and the Benjamin-Ono equation are the unique integrable cases within a particular class of integro-differential equations. Furthermore, we explain how the perturbative symmetry approach is naturally extended to treat equations on a periodic domain. (letter to the editor)

Partial Differential Equations in General Relativity

International Nuclear Information System (INIS)

Choquet-Bruhat, Yvonne

2008-01-01

General relativity is a physical theory basic in the modeling of the universe at the large and small scales. Its mathematical formulation, the Einstein partial differential equations, are geometrically simple, but intricate for the analyst, involving both hyperbolic and elliptic PDE, with local and global problems. Many problems remain open though remarkable progress has been made recently towards their solutions. Alan Rendall's book states, in a down-to-earth form, fundamental results used to solve different types of equations. In each case he gives applications to special models as well as to general properties of Einsteinian spacetimes. A chapter on ODE contains, in particular, a detailed discussion of Bianchi spacetimes. A chapter entitled 'Elliptic systems' treats the Einstein constraints. A chapter entitled 'Hyperbolic systems' is followed by a chapter on the Cauchy problem and a chapter 'Global results' which contains recently proved theorems. A chapter is dedicated to the Einstein-Vlasov system, of which the author is a specialist. On the whole, the book surveys, in a concise though precise way, many essential results of recent interest in mathematical general relativity, and it is very clearly written. Each chapter is followed by an up to date bibliography. In conclusion, this book will be a valuable asset to relativists who wish to learn clearly-stated mathematical results and to mathematicians who want to penetrate into the subtleties of general relativity, as a mathematical and physical theory. (book review)

Partial Differential Equations in General Relativity

Energy Technology Data Exchange (ETDEWEB)

Choquet-Bruhat, Yvonne

2008-09-07

General relativity is a physical theory basic in the modeling of the universe at the large and small scales. Its mathematical formulation, the Einstein partial differential equations, are geometrically simple, but intricate for the analyst, involving both hyperbolic and elliptic PDE, with local and global problems. Many problems remain open though remarkable progress has been made recently towards their solutions. Alan Rendall's book states, in a down-to-earth form, fundamental results used to solve different types of equations. In each case he gives applications to special models as well as to general properties of Einsteinian spacetimes. A chapter on ODE contains, in particular, a detailed discussion of Bianchi spacetimes. A chapter entitled 'Elliptic systems' treats the Einstein constraints. A chapter entitled 'Hyperbolic systems' is followed by a chapter on the Cauchy problem and a chapter 'Global results' which contains recently proved theorems. A chapter is dedicated to the Einstein-Vlasov system, of which the author is a specialist. On the whole, the book surveys, in a concise though precise way, many essential results of recent interest in mathematical general relativity, and it is very clearly written. Each chapter is followed by an up to date bibliography. In conclusion, this book will be a valuable asset to relativists who wish to learn clearly-stated mathematical results and to mathematicians who want to penetrate into the subtleties of general relativity, as a mathematical and physical theory. (book review)

Relations between nonlinear Riccati equations and other equations in fundamental physics

International Nuclear Information System (INIS)

Schuch, Dieter

2014-01-01

Many phenomena in the observable macroscopic world obey nonlinear evolution equations while the microscopic world is governed by quantum mechanics, a fundamental theory that is supposedly linear. In order to combine these two worlds in a common formalism, at least one of them must sacrifice one of its dogmas. Linearizing nonlinear dynamics would destroy the fundamental property of this theory, however, it can be shown that quantum mechanics can be reformulated in terms of nonlinear Riccati equations. In a first step, it will be shown that the information about the dynamics of quantum systems with analytical solutions can not only be obtainable from the time-dependent Schrödinger equation but equally-well from a complex Riccati equation. Comparison with supersymmetric quantum mechanics shows that even additional information can be obtained from the nonlinear formulation. Furthermore, the time-independent Schrödinger equation can also be rewritten as a complex Riccati equation for any potential. Extension of the Riccati formulation to include irreversible dissipative effects is straightforward. Via (real and complex) Riccati equations, other fields of physics can also be treated within the same formalism, e.g., statistical thermodynamics, nonlinear dynamical systems like those obeying a logistic equation as well as wave equations in classical optics, Bose- Einstein condensates and cosmological models. Finally, the link to abstract ''quantizations'' such as the Pythagorean triples and Riccati equations connected with trigonometric and hyperbolic functions will be shown

Age-related changes in visual temporal order judgment performance: Relation to sensory and cognitive capacities.

Science.gov (United States)

Busey, Thomas; Craig, James; Clark, Chris; Humes, Larry

2010-08-06

Five measures of temporal order judgments were obtained from 261 participants, including 146 elder, 44 middle aged, and 71 young participants. Strong age group differences were observed in all five measures, although the group differences were reduced when letter discriminability was matched for all participants. Significant relations were found between these measures of temporal processing and several cognitive and sensory assays, and structural equation modeling revealed the degree to which temporal order processing can be viewed as a latent factor that depends in part on contributions from sensory and cognitive capacities. The best-fitting model involved two different latent factors representing temporal order processing at same and different locations, and the sensory and cognitive factors were more successful predicting performance in the different location factor than the same-location factor. Processing speed, even measured using high-contrast symbols on a paper-and-pencil test, was a surprisingly strong predictor of variability in both latent factors. However, low-level sensory measures also made significant contributions to the latent factors. The results demonstrate the degree to which temporal order processing relates to other perceptual and cognitive capacities, and address the question of whether age-related declines in these capacities share a common cause. Copyright 2010 Elsevier Ltd. All rights reserved.

Spectral transform and orthogonality relations for the Kadomtsev-Petviashvili I equation

Energy Technology Data Exchange (ETDEWEB)

Boiti, M; Leon, J J.P.; Pempinelli, F [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique

1989-10-30

We define a new spectral transform r(k,l) of the potential u in the time dependent Schroedinger equation (associated to the KPI equation). Orthogonality relations for the sectionally holomorphic eigenfunctions of the Schroedinger equation are used to express the spectral transform f(k,l) previously introduced by Manakov and Fokas and Ablowitz in terms of r(k,l). The main advantage of the new spectral transform r(k,l) is that its definition does not require to introduce an additional nonanalytic eigenfunction N. Characterization equations for r(k,l) are also obtained. (orig.).

Spectral transform and orthogonality relations for the Kadomtsev-Petviashvili I equation

International Nuclear Information System (INIS)

Boiti, M.; Leon, J.J.P.; Pempinelli, F.

1989-01-01

We define a new spectral transform r(k,l) of the potential u in the time dependent Schroedinger equation (associated to the KPI equation). Orthogonality relations for the sectionally holomorphic eigenfunctions of the Schroedinger equation are used to express the spectral transform f(k,l) previously introduced by Manakov and Fokas and Ablowitz in terms of r(k,l). The main advantage of the new spectral transform r(k,l) is that its definition does not require to introduce an additional nonanalytic eigenfunction N. Characterization equations for r(k,l) are also obtained. (orig.)

Tracer kinetics: Modelling by partial differential equations of inhomogeneous compartments with age-dependent elimination rates. Pt. 1

International Nuclear Information System (INIS)

Winkler, E.

1991-01-01

Mathematical models in tracer kinetics are usually based on ordinary differential equations which correspond to a system of kinetically homogeneous compartments (standard compartments). A generalization is possible by the admission of inhomogeneities in the behaviour of the elements belonging to a compartment. The important special case of the age-dependence of elimination rates is treated in its deterministic version. It leads to partial different equations (i.e., systems with distributed coefficients) with the 'age' or the 'residence time' of an element of the compartment as a variable additional to 'time'. The basic equations for one generalized compartment and for systems of such compartments are given together with their general solutions. (orig.) [de

A goods characteristics model of the hedonic ageing equation: evidence from a French marriage bureau

OpenAIRE

Sam Cameron; Nicolas Vaillant

2005-01-01

The present paper adopts a modelling perspective derived from goods characteristics analysis [Lancaster (1971)] and the general ideas of transactions costs. This is implemented in estimated equations, which feature the age of partner sought as the dependent variable and own age and various other personal characteristics, and characteristics desired in a partner, as the right-hand side variables. The results show a very strong relationship between age and desired partner age. More interestingl...

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

Science.gov (United States)

Nikolaidis, Pantelis T.; Rosemann, Thomas; Knechtle, Beat

2018-01-01

Age-based prediction equations of maximal heart rate (HRmax), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HRmax for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants (n = 180, age 43.2 ± 8.5 years, VO2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HRmax was measured. Measured HRmax correlated largely with age in the total sample (r = −0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR. PMID:29599724

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations.

Science.gov (United States)

Nikolaidis, Pantelis T; Rosemann, Thomas; Knechtle, Beat

2018-01-01

Age-based prediction equations of maximal heart rate (HR max ), such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HR max for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants ( n = 180, age 43.2 ± 8.5 years, VO 2max 46.8 mL/min/kg, finishers in at least one marathon during the last year) performed a graded exercise test on a treadmill, where HR max was measured. Measured HR max correlated largely with age in the total sample ( r = -0.50, p marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR.

Kinetic Boltzmann, Vlasov and Related Equations

CERN Document Server

Sinitsyn, Alexander; Vedenyapin, Victor

2011-01-01

Boltzmann and Vlasov equations played a great role in the past and still play an important role in modern natural sciences, technique and even philosophy of science. Classical Boltzmann equation derived in 1872 became a cornerstone for the molecular-kinetic theory, the second law of thermodynamics (increasing entropy) and derivation of the basic hydrodynamic equations. After modifications, the fields and numbers of its applications have increased to include diluted gas, radiation, neutral particles transportation, atmosphere optics and nuclear reactor modelling. Vlasov equation was obtained in

Relating systems properties of the wave and the Schrödinger equation

NARCIS (Netherlands)

Zwart, Heiko J.; Le Gorrec, Yann; Maschke, B.M.

In this article we show that systems properties of the systems governed by the second order differential equation d2wdt2=−A0w and the first order differential equation dzdt=iA0z are related. This can be used to show that, for instance, exact observability of the N-dimensional wave equation implies

Regression equations to predict 6-minute walk distance in Chinese adults aged 55–85 years

OpenAIRE

Shirley P.C. Ngai, PhD; Alice Y.M. Jones, PhD; Sue C. Jenkins, PhD

2014-01-01

The 6-minute walk distance (6MWD) is used as a measure of functional exercise capacity in clinical populations and research. Reference equations to predict 6MWD in different populations have been established, however, available equations for Chinese population are scarce. This study aimed to develop regression equations to predict the 6MWD for a Hong Kong Chinese population. Fifty-three healthy individuals (25 men, 28 women; mean age = 69.3 ± 6.5 years) participated in this cross-sectional st...

Hecke symmetries and characteristic relations on reflection equation algebras

International Nuclear Information System (INIS)

Gurevich, D.I.; Pyatov, P.N.

1996-01-01

We discuss how properties of Hecke symmetry (i.e., Hecke type R-matrix) influence the algebraic structure of the corresponding Reflection Equation (RE) algebra. Analogues of the Newton relations and Cayley-Hamilton theorem for the matrix of generators of the RE algebra related to a finite rank even Hecke symmetry are derived. 10 refs

Health-related physical fitness measures: reference values and reference equations for use in clinical practice.

Science.gov (United States)

Tveter, Anne Therese; Dagfinrud, Hanne; Moseng, Tuva; Holm, Inger

2014-07-01

To provide reference values and reference equations for frequently used clinical field tests of health-related physical fitness for use in clinical practice. Cross-sectional design. General community. Convenience sample of volunteers (N=370) between 18 and 90 years of age were recruited from a wide range of settings (ie, work sites, schools, community centers for older adults) and different geographic locations (ie, urban, suburban, rural) in southeastern Norway. Not applicable. The participants conducted 5 clinical field tests (6-minute walk test, stair test, 30-second sit-to-stand test, handgrip test, fingertip-to-floor test). The results of the field tests showed that performance remained unchanged until approximately 50 years of age; after that, performance deteriorated with increasing age. Grip strength (79%), meters walked in 6 minutes (60%), and seconds used on the stair test (59%) could be well predicted by age, sex, height, and weight in participants ≥50 years of age, whereas the performance on all tests was less well predicted in participants clinical practice. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Age-related hearing loss

Science.gov (United States)

... grow older. Your genes and loud noise (from rock concerts or music headphones) may play a large role. The following factors contribute to age-related hearing loss: Family history (age-related hearing loss tends to run in ...

Developments in functional equations and related topics

CERN Document Server

Ciepliński, Krzysztof; Rassias, Themistocles

2017-01-01

This book presents current research on Ulam stability for functional equations and inequalities. Contributions from renowned scientists emphasize fundamental and new results, methods and techniques. Detailed examples are given to theories to further understanding at the graduate level for students in mathematics, physics, and engineering. Key topics covered in this book include: Quasi means Approximate isometries Functional equations in hypergroups Stability of functional equations Fischer-Muszély equation Haar meager sets and Haar null sets Dynamical systems Functional equations in probability theory Stochastic convex ordering Dhombres functional equation Nonstandard analysis and Ulam stability This book is dedicated in memory of Staniłsaw Marcin Ulam, who posed the fundamental problem concerning approximate homomorphisms of groups in 1940; which has provided the stimulus for studies in the stability of functional equations and inequalities.

Visual function and cognitive speed of processing mediate age-related decline in memory span and fluid intelligence.

Science.gov (United States)

Clay, Olivio J; Edwards, Jerri D; Ross, Lesley A; Okonkwo, Ozioma; Wadley, Virginia G; Roth, David L; Ball, Karlene K

2009-06-01

To evaluate the relationship between sensory and cognitive decline, particularly with respect to speed of processing, memory span, and fluid intelligence. In addition, the common cause, sensory degradation and speed of processing hypotheses were compared. Structural equation modeling was used to investigate the complex relationships among age-related decrements in these areas. Cross-sectional data analyses included 842 older adult participants (M = 73 years). After accounting for age-related declines in vision and processing speed, the direct associations between age and memory span and between age and fluid intelligence were nonsignificant. Older age was associated with visual decline, which was associated with slower speed of processing, which in turn was associated with greater cognitive deficits. The findings support both the sensory degradation and speed of processing accounts of age-related, cognitive decline. Furthermore, the findings highlight positive aspects of normal cognitive aging in that older age may not be associated with a loss of fluid intelligence if visual sensory functioning and processing speed can be maintained.

Glomerular filtration rate equations overestimate creatinine clearance in older individuals enrolled in the Baltimore Longitudinal Study on Aging: impact on renal drug dosing.

Science.gov (United States)

Dowling, Thomas C; Wang, En-Shih; Ferrucci, Luigi; Sorkin, John D

2013-09-01

To evaluate the performance of kidney function estimation equations and to determine the frequency of drug dose discordance in an older population. Cross-sectional analysis of data from community-dwelling volunteers randomly selected from the Baltimore Longitudinal Study of Aging from January 1, 2005, to December 31, 2010. A total of 269 men and women with a mean ± SD age of 81 ± 6 years, mean serum creatinine concentration (Scr ) of 1.1 ± 0.4 mg/dl, and mean 24-hour measured creatinine clearance (mClcr ) of 53 ± 13 ml/minute. Kidney function was estimated by using the following equations: Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). The performance of each equation was assessed by measuring bias and precision relative to mClcr . Dose calculation errors (discordance) were determined for 10 drugs requiring renal dosage adjustments to avoid toxicity when compared with the dosages approved by the Food and Drug Administration. The CG equation was the least biased estimate of mClcr . The MDRD and CKD-EPI equations were significantly positively biased compared with CG (mean ± SD 34 ± 20% and 22 ± 15%, respectively, prenal impairment. Thus equations estimating glomerular filtration rate should not be substituted in place of the CG equation in older adults for the purpose of renal dosage adjustments. In addition, the common practice of rounding or replacing low Scr values with an arbitrary value of 1.0 mg/dl for use in the CG equation should be avoided. Additional studies that evaluate alternative eGFR equations in the older populations that incorporate pharmacokinetic and pharmacodynamic outcomes measures are needed. © 2013 Pharmacotherapy Publications, Inc.

Study for Relation of Pressure and Aging Degradation during LOCA Test

International Nuclear Information System (INIS)

Kim, Jong Seog

2013-01-01

As result of this test, it was found that low pressure effect in aging was not significant compared with that of temperature. If temperature profile in LOCA test can satisfy the plant LOCA profile, no further analysis of pressure profile for aging degradation is necessary. For environmental qualification of electric equipment in containment building of nuclear power plant, LOCA test should be applied. During the LOCA test, temperature and pressure of LOCA chamber shall be controlled to meet a requirement of plant specific LOCA profile. It is general to keep LOCA test temperature and pressure above the plant specific LOCA profile. If the test temperature is lower than required profile in some time zone while it is higher in other time zone, calculation of total cumulated test temperature is required to compare with that of plant profile. Arrhenius equation can be applied for calculation of total temperature accumulation. If there is a deviation of pressure between test profile and plant specific profile, can we still use the same rule of temperature? Since the Arrhenius equation can't be applied to pressure, analysis of pressure effect to aging degradation is not easy. Study for relation of pressure and aging degradation during LOCA condition is described herein. To Study an aging degradation effect of pressure during LOCA test, comparison of IR during high LOCA pressure and low LOCA pressure were implemented. We expected low IR in high pressure because it contained a high concentration of oxygen which induces high aging degradation. Contrary to our expectation, IR of low pressure was lower than that of high pressure. It is assumed that high vibration of temperature profile to maintain the low pressure at high temperature induced supply of high enthalpy steam into LOCA chamber

Nonuniqueness of the two-temperature Saha equation and related considerations

International Nuclear Information System (INIS)

Giordano, D.; Capitelli, M.

2002-01-01

The present paper contains considerations relative to the long debated thermodynamic derivation of two-temperature Saha equations. The main focus of our discourse is on the dependence of the multitemperature equilibrium conditions on the constraints imposed on the thermodynamic system. We also examine the following key issues related to that dependence: correspondence between constraints and equilibrium-equation forms that have appeared in the literature; presumed dominance of the free-electron translational temperature in the two-temperature expression of the equilibrium constant of the ionization reaction A A + +e - ; disagreement between the derivation methods based on, respectively, the extended second law of classical thermodynamics and axiomatic thermodynamics; and plausibility of the existence of entropic constraints

Survey on Dirac equation in general relativity theory

International Nuclear Information System (INIS)

Paillere, P.

1984-10-01

Starting from an infinitesimal transformation expressed with a Killing vector and using systematically the formalism of the local tetrades, we show that, in the area of the general relativity, the Dirac equation may be formulated only versus the four local vectors which determine the gravitational potentials, their gradients and the 4-vector potential of the electromagnetic field [fr

On the Operator ⨁Bk Related to Bessel Heat Equation

Directory of Open Access Journals (Sweden)

Wanchak Satsanit

2010-01-01

Full Text Available We study the equation (∂/∂tu(x,t=c2⊕Bku(x,t with the initial condition u(x,0=f(x for x∈Rn+. The operator ⊕Bk is the operator iterated k-times and is defined by ⊕Bk=((∑i=1pBxi4-(∑j=p+1p+qBxi4k, where p+q=n is the dimension of the Rn+, Bxi=∂2/∂xi2+(2vi/xi(∂/∂xi, 2vi=2αi+1, αi>-1/2, i=1,2,3,…,n, and k is a nonnegative integer, u(x,t is an unknown function for (x,t=(x1,x2,…,xn,t∈Rn+×(0,∞, f(x is a given generalized function, and c is a positive constant. We obtain the solution of such equation, which is related to the spectrum and the kernel, which is so called Bessel heat kernel. Moreover, such Bessel heat kernel has interesting properties and also related to the kernel of an extension of the heat equation.

Hyperbolic partial differential equations populations, reactors, tides and waves theory and applications

CERN Document Server

Witten, Matthew

1983-01-01

Hyperbolic Partial Differential Equations, Volume 1: Population, Reactors, Tides and Waves: Theory and Applications covers three general areas of hyperbolic partial differential equation applications. These areas include problems related to the McKendrick/Von Foerster population equations, other hyperbolic form equations, and the numerical solution.This text is composed of 15 chapters and begins with surveys of age specific population interactions, populations models of diffusion, nonlinear age dependent population growth with harvesting, local and global stability for the nonlinear renewal eq

The relation among the hyperbolic-function-type exact solutions of nonlinear evolution equations

International Nuclear Information System (INIS)

Liu Chunping; Liu Xiaoping

2004-01-01

First, we investigate the solitary wave solutions of the Burgers equation and the KdV equation, which are obtained by using the hyperbolic function method. Then we present a theorem which will not only give us a clear relation among the hyperbolic-function-type exact solutions of nonlinear evolution equations, but also provide us an approach to construct new exact solutions in complex scalar field. Finally, we apply the theorem to the KdV-Burgers equation and obtain its new exact solutions

Topographic and age-related changes of the retinal epithelium and Bruch's membrane of rhesus monkeys.

Science.gov (United States)

Gouras, Peter; Ivert, Lena; Neuringer, Martha; Mattison, Julie A

2010-07-01

To examine structural differences in the retinal pigmented epithelium (RPE) and Bruch's membrane of rhesus monkeys (Macaca mulatta) as a function of topography and age. The retinas of two old (24 and 26 years old) and two young (1 and 6 years old) female monkeys were examined by light fluorescence and electron microscopy at the macula, equator, and ora serrata. All monkeys lacked fluorescence and lipofuscin granules in the RPE at the ora serrata where photoreceptors are absent. The equator and macula showed intense fluorescence and many lipofuscin granules in the RPE of the old but not the young monkeys. At the ora, the RPE contained many dense round melanin granules throughout the cell. At the equator and macula, melanin granules were more apical, less frequent, and often elongated. Mitochondria were clustered at the basal side of the RPE cell near infolds of the plasma membrane. Both mitochondria and infolds tended to increase toward the macula. In all regions, the basal lamina of the RPE did not penetrate the extracellular space adjacent to infolds. The elastin layer of Bruch's membrane was wide at the ora and equator and thinner at the macula. In the old monkeys, drusen were found at all retinal regions between the basal lamina and the internal collagen layer of Bruch's membrane. The drusen were often membrane-bound with a basal lamina and contained material resembling structures in the RPE. Lack of fluorescence and lipofuscin in the RPE at the ora serrata, where photoreceptors are absent, confirms that RPE fluorescence occurs only where outer segments are phagocytized. Mitochondrial clustering indicates that the basal side of the RPE cell uses the most energy and this becomes maximal at the macula. The presence of age-related degenerative changes and drusen at all retinal locations in the older monkeys, even at the ora where RPE lipofuscin was absent, indicates that these processes are not dependent on local lipofuscin accumulation. Therefore lipofuscin

A data mining approach for classifying DNA repair genes into ageing-related or non-ageing-related

Directory of Open Access Journals (Sweden)

Vasieva Olga

2011-01-01

Full Text Available Abstract Background The ageing of the worldwide population means there is a growing need for research on the biology of ageing. DNA damage is likely a key contributor to the ageing process and elucidating the role of different DNA repair systems in ageing is of great interest. In this paper we propose a data mining approach, based on classification methods (decision trees and Naive Bayes, for analysing data about human DNA repair genes. The goal is to build classification models that allow us to discriminate between ageing-related and non-ageing-related DNA repair genes, in order to better understand their different properties. Results The main patterns discovered by the classification methods are as follows: (a the number of protein-protein interactions was a predictor of DNA repair proteins being ageing-related; (b the use of predictor attributes based on protein-protein interactions considerably increased predictive accuracy of attributes based on Gene Ontology (GO annotations; (c GO terms related to "response to stimulus" seem reasonably good predictors of ageing-relatedness for DNA repair genes; (d interaction with the XRCC5 (Ku80 protein is a strong predictor of ageing-relatedness for DNA repair genes; and (e DNA repair genes with a high expression in T lymphocytes are more likely to be ageing-related. Conclusions The above patterns are broadly integrated in an analysis discussing relations between Ku, the non-homologous end joining DNA repair pathway, ageing and lymphocyte development. These patterns and their analysis support non-homologous end joining double strand break repair as central to the ageing-relatedness of DNA repair genes. Our work also showcases the use of protein interaction partners to improve accuracy in data mining methods and our approach could be applied to other ageing-related pathways.

Generalized Bondi-Sachs equations for characteristic formalism of numerical relativity

Science.gov (United States)

Cao, Zhoujian; He, Xiaokai

2013-11-01

The Cauchy formalism of numerical relativity has been successfully applied to simulate various dynamical spacetimes without any symmetry assumption. But discovering how to set a mathematically consistent and physically realistic boundary condition is still an open problem for Cauchy formalism. In addition, the numerical truncation error and finite region ambiguity affect the accuracy of gravitational wave form calculation. As to the finite region ambiguity issue, the characteristic extraction method helps much. But it does not solve all of the above issues. Besides the above problems for Cauchy formalism, the computational efficiency is another problem. Although characteristic formalism of numerical relativity suffers the difficulty from caustics in the inner near zone, it has advantages in relation to all of the issues listed above. Cauchy-characteristic matching (CCM) is a possible way to take advantage of characteristic formalism regarding these issues and treat the inner caustics at the same time. CCM has difficulty treating the gauge difference between the Cauchy part and the characteristic part. We propose generalized Bondi-Sachs equations for characteristic formalism for the Cauchy-characteristic matching end. Our proposal gives out a possible same numerical evolution scheme for both the Cauchy part and the characteristic part. And our generalized Bondi-Sachs equations have one adjustable gauge freedom which can be used to relate the gauge used in the Cauchy part. Then these equations can make the Cauchy part and the characteristic part share a consistent gauge condition. So our proposal gives a possible new starting point for Cauchy-characteristic matching.

On the equivalence of vacuum equations of gauge quadratic theory of gravity and general relativity theory

International Nuclear Information System (INIS)

Zhitnikov, V.V.; Ponomarev, V.N.

1986-01-01

An attempt is made to compare the solution of field equations, corresponding to quadratic equations for the fields (g μν , Γ μν α ) in gauge gravitation theory (GGT) with general relativity theory solutions. Without restrictions for a concrete type of metrics only solutions of equations, for which torsion turns to zero, are considered. Equivalence of vacuum equations of gauge quadratic theory of gravity and general relativity theory is proved using the Newman-Penrose formalism

The effect of cardiorespiratory fitness on age-related lipids and lipoproteins.

Science.gov (United States)

Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F; Lavie, Carl J; Hardin, James W; Blair, Steven N

2015-05-19

Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-age men than in older men. Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

On the relation between elementary partial difference equations and partial differential equations

NARCIS (Netherlands)

van den Berg, I.P.

1998-01-01

The nonstandard stroboscopy method links discrete-time ordinary difference equations of first-order and continuous-time, ordinary differential equations of first order. We extend this method to the second order, and also to an elementary, yet general class of partial difference/differential

Age-related oral changes.

LENUS (Irish Health Repository)

Mckenna, Gerald

2010-10-01

Age-related oral changes are seen in the oral hard and soft tissues as well as in bone, the temporomandibular joints and the oral mucosa. As older patients retain their natural teeth for longer, the clinical picture consists of normal physiological age changes in combination with pathological and iatrogenic effects. Clinical Relevance: With an ageing population retaining more of its natural teeth for longer, dental professionals should expect to observe oral age changes more frequently.

Early selection versus late correction: Age-related differences in controlling working memory contents.

Science.gov (United States)

Schwarzkopp, Tina; Mayr, Ulrich; Jost, Kerstin

2016-08-01

We examined whether a reduced ability to ignore irrelevant information is responsible for the age-related decline of working memory (WM) functions. By means of event-related brain potentials, we will show that filtering is not out of service in older adults but shifted to a later processing stage. Participants performed a visual short-term memory task (change-detection task) in which targets were presented along with distractors. To allow early selection, a cue was presented in advance of each display, indicating where the targets were to appear. Despite this relatively easy selection criterion, older adults' filtering was delayed as indicated by the amplitude pattern of the contralateral delay activity. Importantly, WM-equated younger adults did not show a delay indicating that the delay is specific to older adults and not a general phenomenon that comes with low WM capacity. Moreover, the analysis of early visual potentials revealed qualitatively different perceptual/attentional processing between the age groups. Young adults exhibited stronger distractor sensitivity that in turn facilitated filtering. Older adults, in contrast, seemed to initially store distractors and to suppress them after the fact. These early selection versus late-correction modes suggest an age-related shift in the strategy to control the contents of WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Iterated Crank-Nicolson method for hyperbolic and parabolic equations in numerical relativity

International Nuclear Information System (INIS)

Leiler, Gregor; Rezzolla, Luciano

2006-01-01

The iterated Crank-Nicolson is a predictor-corrector algorithm commonly used in numerical relativity for the solution of both hyperbolic and parabolic partial differential equations. We here extend the recent work on the stability of this scheme for hyperbolic equations by investigating the properties when the average between the predicted and corrected values is made with unequal weights and when the scheme is applied to a parabolic equation. We also propose a variant of the scheme in which the coefficients in the averages are swapped between two corrections leading to systematically larger amplification factors and to a smaller numerical dispersion

Equations of motion in general relativity of a small charged black hole

International Nuclear Information System (INIS)

Futamase, T.; Hogan, P. A.; Itoh, Y.

2008-01-01

We present the details of a model in general relativity of a small charged black hole moving in an external gravitational and electromagnetic field. The importance of our model lies in the fact that we can derive the equations of motion of the black hole from the Einstein-Maxwell vacuum field equations without encountering infinities. The key assumptions which we base our results upon are that (a) the black hole is isolated and (b) near the black hole the wave fronts of the radiation generated by its motion are smoothly deformed spheres. The equations of motion which emerge fit the pattern of the original DeWitt and Brehme equations of motion (after they 'renormalize'). Our calculations are carried out in a coordinate system in which the null hypersurface histories of the wave fronts can be specified in a simple way, with the result that we obtain a new explicit form, particular to our model, for the well-known ''tail term'' in the equations of motion.

The Impact of Cardiorespiratory Fitness on Age-Related Lipids and Lipoproteins

Science.gov (United States)

Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F.; Lavie, Carl J.; Hardin, James W.; Blair, Steven N.

2015-01-01

Background Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. Objectives This study sought to assess the longitudinal, aging trajectory of lipids and lipoproteins for the life course in adults, and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Methods Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 (mean 3.5) health examinations between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Results Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until the mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-aged men than in older men. Conclusions Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men, and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. PMID:25975472

Interventions for age-related diseases

DEFF Research Database (Denmark)

Figueira, Inês; Fernandes, Adelaide; Mladenovic Djordjevic, Aleksandra

2016-01-01

Over 60% of people aged over 65 are affected by multiple morbidities, which are more difficult to treat, generate increased healthcare costs and lead to poor quality of life compared to individual diseases. With the number of older people steadily increasing this presents a societal challenge. Age...... is the major risk factor for age-related diseases and recent research developments have led to the proposal that pharmacological interventions targeting common mechanisms of ageing may be able to delay the onset of multimorbidity. Here we review the state of the knowledge of multimorbidity, appraise...... the available evidence supporting the role of mechanisms of ageing in the development of the most common age-related diseases and assess potential molecules that may successfully target those key mechanisms....

The period-age relation for cepheids

International Nuclear Information System (INIS)

Efremov, Yu.N.

1978-01-01

The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

Multiple linear regression to develop strength scaled equations for knee and elbow joints based on age, gender and segment mass

DEFF Research Database (Denmark)

D'Souza, Sonia; Rasmussen, John; Schwirtz, Ansgar

2012-01-01

and valuable ergonomic tool. Objective: To investigate age and gender effects on the torque-producing ability in the knee and elbow in older adults. To create strength scaled equations based on age, gender, upper/lower limb lengths and masses using multiple linear regression. To reduce the number of dependent...... flexors. Results: Males were signifantly stronger than females across all age groups. Elbow peak torque (EPT) was better preserved from 60s to 70s whereas knee peak torque (KPT) reduced significantly (PGender, thigh mass and age best...... predicted KPT (R2=0.60). Gender, forearm mass and age best predicted EPT (R2=0.75). Good crossvalidation was established for both elbow and knee models. Conclusion: This cross-sectional study of muscle strength created and validated strength scaled equations of EPT and KPT using only gender, segment mass...

On the reduction of the multidimensional stationary Schroedinger equation to a first-order equation and its relation to the pseudoanalytic function theory

Energy Technology Data Exchange (ETDEWEB)

Kravchenko, Vladislav V [Departmento de Telecomunicaciones, SEPI, Escuela Superior de IngenierIa Mecanica y Electrica, Instituto Politecnico Nacional, CP 07738 Mexico DF (Mexico)

2005-01-28

Given a particular solution of a one-dimensional stationary Schroedinger equation this equation of second order can be reduced to a first-order linear ordinary differential equation. This is done with the aid of an auxiliary Riccati differential equation. In the present work we show that the same fact is true in a multidimensional situation also. For simplicity we consider the case of two or three independent variables. One particular solution of the stationary Schroedinger equation allows us to reduce this second-order equation to a linear first-order quaternionic differential equation. As in the one-dimensional case this is done with the aid of an auxiliary quaternionic Riccati equation. The resulting first-order quaternionic equation is equivalent to the static Maxwell system and is closely related to the Dirac equation. In the case of two independent variables it is the well-known Vekua equation from theory of pseudoanalytic (or generalized analytic) functions. Nevertheless, we show that even in this case it is very useful to consider not only complex valued functions, solutions of the Vekua equation, but complete quaternionic functions. In this way the first-order quaternionic equation represents two separate Vekua equations, one of which gives us solutions of the Schroedinger equation and the other one can be considered as an auxiliary equation of a simpler structure. Moreover for the auxiliary equation we always have the corresponding Bers generating pair (F, G), the base of the Bers theory of pseudoanalytic functions, and what is very important, the Bers derivatives of solutions of the auxiliary equation give us solutions of the main Vekua equation and as a consequence of the Schroedinger equation. Based on this fact we obtain an analogue of the Cauchy integral theorem for solutions of the stationary Schroedinger equation. Other results from theory of pseudoanalytic functions can be written for solutions of the Schroedinger equation. Moreover, for an ample

Staying on Task: Age-Related Changes in the Relationship Between Executive Functioning and Response Time Consistency.

Science.gov (United States)

Vasquez, Brandon P; Binns, Malcolm A; Anderson, Nicole D

2016-03-01

Little is known about the relationship of executive functioning with age-related increases in response time (RT) distribution indices (intraindividual standard deviation [ISD], and ex-Gaussian parameters mu, sigma, tau). The goals of this study were to (a) replicate findings of age-related changes in response time distribution indices during an engaging touch-screen RT task and (b) investigate age-related changes in the relationship between executive functioning and RT distribution indices. Healthy adults (24 young [aged 18-30], 24 young-old [aged 65-74], and 24 old-old [aged 75-85]) completed a touch-screen attention task and a battery of neuropsychological tests. The relationships between RT performance and executive functions were examined with structural equation modeling (SEM). ISD, mu, and tau, but not sigma, increased with age. SEM revealed tau as the most salient RT index associated with neuropsychological measures of executive functioning. Further analysis demonstrated that correlations between tau and a weighted executive function composite were significant only in the old-old group. Our results replicate findings of greater RT inconsistency in older adults and reveal that executive functioning is related to tau in adults aged 75-85. These results support literature identifying tau as a marker of cognitive control, which deteriorates in old age. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Age-related aspects of addiction

OpenAIRE

Koechl, Birgit; Unger, Annemarie; Fischer, Gabriele

2012-01-01

Research has shown that substance use, abuse and addiction are not limited to a specific age group. Problems related to substance addiction are an important cause of morbidity in the population aged 65 and above, especially the abuse of prescription drugs and legal substances. A lack of evidence-based studies and tailored treatment options for the aging population is evident. Appropriate and effective health-care is an important goal to improve health-related quality of life of elderly people...

Age-Related White Matter Changes

Directory of Open Access Journals (Sweden)

Yun Yun Xiong

2011-01-01

Full Text Available Age-related white matter changes (WMC are considered manifestation of arteriolosclerotic small vessel disease and are related to age and vascular risk factors. Most recent studies have shown that WMC are associated with a host of poor outcomes, including cognitive impairment, dementia, urinary incontinence, gait disturbances, depression, and increased risk of stroke and death. Although the clinical relevance of WMC has been extensively studied, to date, only very few clinical trials have evaluated potential symptomatic or preventive treatments for WMC. In this paper, we reviewed the current understanding in the pathophysiology, epidemiology, clinical importance, chemical biomarkers, and treatments of age-related WMC.

Tracer kinetics: Modelling by partial differential equations of inhomogeneous compartments with age-dependent elimination rates. Pt. 2

International Nuclear Information System (INIS)

Winkler, E.

1991-01-01

The general theory of inhomogeneous compartments with age-dependent elimination rates is illustrated by examples. Mathematically, it turns out that models consisting of partial differential equations include ordinary, delayed and integro-differential equations, a general fact which is treated here in the context of linear tracer kinetics. The examples include standard compartments as a degenerate case, systems of standard compartments (compartment blocks), models resulting in special residence time distributions, models with pipes, and systems with heterogeneous particles. (orig./BBR) [de

On the Volterra integral equation relating creep and relaxation

International Nuclear Information System (INIS)

Anderssen, R S; De Hoog, F R; Davies, A R

2008-01-01

The evolving stress–strain response of a material to an applied deformation is causal. If the current response depends on the earlier history of the stress–strain dynamics of the material (i.e. the material has memory), then Volterra integral equations become the natural framework within which to model the response. For viscoelastic materials, when the response is linear, the dual linear Boltzmann causal integral equations are the appropriate model. The choice of one rather than the other depends on whether the applied deformation is a stress or a strain, and the associated response is, respectively, a creep or a relaxation. The duality between creep and relaxation is known explicitly and is referred to as the 'interconversion equation'. Rheologically, its importance relates to the fact that it allows the creep to be determined from knowledge of the relaxation and vice versa. Computationally, it has been known for some time that the recovery of the relaxation from the creep is more problematic than the creep from the relaxation. Recent research, using discrete models for the creep and relaxation, has confirmed that this is an essential feature of interconversion. In this paper, the corresponding result is generalized for continuous models of the creep and relaxation

Splicing regulatory factors, ageing and age-related disease.

Science.gov (United States)

Latorre, Eva; Harries, Lorna W

2017-07-01

Alternative splicing is a co-transcriptional process, which allows for the production of multiple transcripts from a single gene and is emerging as an important control point for gene expression. Alternatively expressed isoforms often have antagonistic function and differential temporal or spatial expression patterns, yielding enormous plasticity and adaptability to cells and increasing their ability to respond to environmental challenge. The regulation of alternative splicing is critical for numerous cellular functions in both pathological and physiological conditions, and deregulated alternative splicing is a key feature of common chronic diseases. Isoform choice is controlled by a battery of splicing regulatory proteins, which include the serine arginine rich (SRSF) proteins and the heterogeneous ribonucleoprotein (hnRNP) classes of genes. These important splicing regulators have been implicated in age-related disease, and in the ageing process itself. This review will outline the important contribution of splicing regulator proteins to ageing and age-related disease. Copyright © 2017 Elsevier B.V. All rights reserved.

A New Solution for Einstein Field Equation in General Relativity

Science.gov (United States)

Mousavi, Sadegh

2006-05-01

There are different solutions for Einstein field equation in general relativity that they have been proposed by different people the most important solutions are Schwarzchild, Reissner Nordstrom, Kerr and Kerr Newmam. However, each one of these solutions limited to special case. I've found a new solution for Einstein field equation which is more complete than all previous ones and this solution contains the previous solutions as its special forms. In this talk I will present my new metric for Einstein field equation and the Christofel symbols and Richi and Rieman tensor components for the new metric that I have calculated them by GR TENSOR software. As a result I will determine the actual movement of black holes which is different From Kerr black hole's movement. Finally this new solution predicts, existence of a new and constant field in the nature (that nobody can found it up to now), so in this talk I will introduce this new field and even I will calculate the amount of this field. SADEGH MOUSAVI, Amirkabir University of Technology.

Prevalence of age-related maculopathy and age-related macular degeneration among the inuit in Greenland. The Greenland Inuit Eye Study

DEFF Research Database (Denmark)

Andersen, Mads Varis Nis; Rosenberg, Thomas; la Cour, Morten

2008-01-01

To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland.......To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland....

Relations between zeros of special polynomials associated with the Painleve equations

International Nuclear Information System (INIS)

Kudryashov, Nikolai A.; Demina, Maria V.

2007-01-01

A method for finding relations of roots of polynomials is presented. Our approach allows us to get a number of relations between the zeros of the classical polynomials as well as the roots of special polynomials associated with rational solutions of the Painleve equations. We apply the method to obtain the relations for the zeros of several polynomials. These are: the Hermite polynomials, the Laguerre polynomials, the Yablonskii-Vorob'ev polynomials, the generalized Okamoto polynomials, and the generalized Hermite polynomials. All the relations found can be considered as analogues of generalized Stieltjes relations

Models for predicting turnover of residential aged care nurses: a structural equation modelling analysis of secondary data.

Science.gov (United States)

Gao, Fengsong; Newcombe, Peter; Tilse, Cheryl; Wilson, Jill; Tuckett, Anthony

2014-09-01

Nurse turnover in the residential aged care industry is a pressing issue. Researchers have shown ongoing interest in exploring how the factors that are amendable to change in aged care policy, regulation and funding and in organizational procedures (e.g. job demands, coping resources and psychological health of nurses) impact on turnover. However, the findings are mixed. This study tested two theoretical models of turnover to examine the structural relationships among job demands, coping resources, psychological health and turnover of residential aged care nurses. Although many previous studies operationalized turnover as intention to leave, the present study investigated actual turnover by following up with the same individuals over time, and thus provided more accurate predictive models of turnover behaviour. The sample, 239 Australian residential aged care nurses, came from the Nurses and Midwives e-cohort Study. Job demands, coping resources, and psychological health were measured using standardized instruments. Structural equation modelling was used to test the measurement and structural models. Controlling for a number of workforce and individual characteristics, coping resources (measured by job control, supervisor support, and co-worker support) were negatively and directly associated with turnover. Additionally, the findings supported the Job Demand-Control-Support model in that higher coping resources and lower job demands (indicated by psychological demands, physical demands, and effort) were related to better psychological health (measured by vitality, social functioning, role emotional, and mental health), and higher job demands were related to lower coping resources. Findings suggest that aged care policy makers and service providers might consider increasing coping resources available to nurses and minimizing job demands of care work to reduce turnover and improve nurses' psychological health. Moreover, findings from this Australian study may provide

Future time perspective and awareness of age-related change: Examining their role in predicting psychological well-being.

Science.gov (United States)

Brothers, Allyson; Gabrian, Martina; Wahl, Hans-Werner; Diehl, Manfred

2016-09-01

This study examined how 2 distinct facets of perceived personal lifetime-future time perspective (FTP) and awareness of age-related change (AARC)-are associated with another, and how they may interact to predict psychological well-being. To better understand associations among subjective perceptions of lifetime, aging, and well-being, we tested a series of models to investigate questions of directionality, indirect effects, and conditional processes among FTP, AARC-Gains, AARC-Losses, and psychological well-being. In all models, we tested for differences between middle-aged and older adults, and between adults from the United States and Germany. Analyses were conducted within a structural equation modeling framework on a cross-national, 2.5-year longitudinal sample of 537 community-residing adults (age 40-98 years). Awareness of age-related losses (AARC-Losses) at Time 1 predicted FTP at Time 2, but FTP did not predict AARC-Gains or AARC-Losses. Furthermore, future time perspective mediated the association between AARC-Losses and well-being. Moderation analyses revealed a buffering effect of awareness of age-related gains (AARC-Gains) in which perceptions of more age-related gains diminished the negative effect of a limited future time perspective on well-being. Effects were robust across age groups and countries. Taken together, these findings suggest that perceived age-related loss experiences may sensitize individuals to perceive a more limited future lifetime which may then lead to lower psychological well-being. In contrast, perceived age-related gains may function as a resource to preserve psychological well-being, in particular when time is perceived as running out. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Averaging problem in general relativity, macroscopic gravity and using Einstein's equations in cosmology.

Science.gov (United States)

Zalaletdinov, R. M.

1998-04-01

The averaging problem in general relativity is briefly discussed. A new setting of the problem as that of macroscopic description of gravitation is proposed. A covariant space-time averaging procedure is described. The structure of the geometry of macroscopic space-time, which follows from averaging Cartan's structure equations, is described and the correlation tensors present in the theory are discussed. The macroscopic field equations (averaged Einstein's equations) derived in the framework of the approach are presented and their structure is analysed. The correspondence principle for macroscopic gravity is formulated and a definition of the stress-energy tensor for the macroscopic gravitational field is proposed. It is shown that the physical meaning of using Einstein's equations with a hydrodynamic stress-energy tensor in looking for cosmological models means neglecting all gravitational field correlations. The system of macroscopic gravity equations to be solved when the correlations are taken into consideration is given and described.

Development and validation of GFR-estimating equations using diabetes, transplant and weight

DEFF Research Database (Denmark)

Stevens, L.A.; Schmid, C.H.; Zhang, Y.L.

2009-01-01

interactions. Equations were developed in a pooled database of 10 studies [2/3 (N = 5504) for development and 1/3 (N = 2750) for internal validation], and final model selection occurred in 16 additional studies [external validation (N = 3896)]. RESULTS: The mean mGFR was 68, 67 and 68 ml/min/ 1.73 m(2......BACKGROUND: We have reported a new equation (CKD-EPI equation) that reduces bias and improves accuracy for GFR estimation compared to the MDRD study equation while using the same four basic predictor variables: creatinine, age, sex and race. Here, we describe the development and validation...... of this equation as well as other equations that incorporate diabetes, transplant and weight as additional predictor variables. METHODS: Linear regression was used to relate log-measured GFR (mGFR) to sex, race, diabetes, transplant, weight, various transformations of creatinine and age with and without...

Aging on a different scale--chronological versus pathology-related aging.

Science.gov (United States)

Melis, Joost P M; Jonker, Martijs J; Vijg, Jan; Hoeijmakers, Jan H J; Breit, Timo M; van Steeg, Harry

2013-10-01

In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging.

The role of hydrogen sulfide in aging and age-related pathologies.

Science.gov (United States)

Perridon, Bernard W; Leuvenink, Henri G D; Hillebrands, Jan-Luuk; van Goor, Harry; Bos, Eelke M

2016-09-27

When humans grow older, they experience inevitable and progressive loss of physiological function, ultimately leading to death. Research on aging largely focuses on the identification of mechanisms involved in the aging process. Several proposed aging theories were recently combined as the 'hallmarks of aging'. These hallmarks describe (patho-)physiological processes that together, when disrupted, determine the aging phenotype. Sustaining evidence shows a potential role for hydrogen sulfide (H 2 S) in the regulation of aging. Nowadays, H 2 S is acknowledged as an endogenously produced signaling molecule with various (patho-) physiological effects. H 2 S is involved in several diseases including pathologies related to aging. In this review, the known, assumed and hypothetical effects of hydrogen sulfide on the aging process will be discussed by reviewing its actions on the hallmarks of aging and on several age-related pathologies.

Structural equation modeling identifies markers of damage and function in the aging male Fischer 344 rat.

Science.gov (United States)

Grunz-Borgmann, Elizabeth A; Nichols, LaNita A; Wiedmeyer, Charles E; Spagnoli, Sean; Trzeciakowski, Jerome P; Parrish, Alan R

2016-06-01

The male Fischer 344 rat is an established model to study progressive renal dysfunction that is similar, but not identical, to chronic kidney disease (CKD) in humans. These studies were designed to assess age-dependent alterations in renal structure and function at late-life timepoints, 16-24 months. Elevations in BUN and plasma creatinine were not significant until 24 months, however, elevations in the more sensitive markers of function, plasma cystatin C and proteinuria, were detectable at 16 and 18 months, respectively. Interestingly, cystatin C levels were not corrected by caloric restriction. Urinary Kim-1, a marker of CKD, was elevated as early as 16 months. Klotho gene expression was significantly decreased at 24 months, but not at earlier timepoints. Alterations in renal structure, glomerulosclerosis and tubulointerstitial fibrosis, were noted at 16 months, with little change from 18 to 24 months. Tubulointerstitial inflammation was increased at 16 months, and remained similar from 18 to 24 months. A SEM (structural equation modeling) model of age-related renal dysfunction suggests that proteinuria is a marker of renal damage, while urinary Kim-1 is a marker of both damage and function. Taken together, these results demonstrate that age-dependent nephropathy begins as early as 16 months and progresses rapidly over the next 8 months. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Glucose and age-related changes in memory.

Science.gov (United States)

Gold, Paul E

2005-12-01

Epinephrine, released from the adrenal medulla, enhances memory in young rats and mice and apparently does so, at least in part, by increasing blood glucose levels. Like epinephrine, administration of glucose enhances cognitive functions in humans and rodents, including reversing age-related impairments in learning and memory. Epinephrine responses to training are increased in aged rats but the subsequent increase in blood glucose levels is severely blunted. The absence of increases in blood glucose levels during training might contribute to age-related deficits in learning and memory. Also, extracellular glucose levels in the hippocampus are depleted during spontaneous alternation testing to a far greater extent in aged than in young rats. Importantly, systemic injections of glucose block the depletion in the hippocampus and also enhance performance on the alternation task. Thus, the extensive depletion of extracellular glucose during training in aged rats may be associated with age-related memory impairments, an effect that might be related to - or may exacerbate - the effects on learning and memory of an absence of the increases in blood glucose levels to training as seen in young rats. Together, these findings suggest that age-related changes in both peripheral and central glucose physiology contribute to age-related impairments in memory.

Age and muscle strength mediate the age-related biomechanical plasticity of gait

NARCIS (Netherlands)

Hortobagyi, Tibor; Rider, Patrick; Gruber, Allison H.; DeVita, Paul

Old compared with young adults walk with reduced ankle and increased hip mechanical output. We examined the idea that age, leg strength, or both are related to the age-related changes in mechanical output during gait. Healthy young (n = 32, age 21.5 years) and old adults (n = 32, age 76.8 years)

Thin-Layer Solutions of the Helmholtz and Related Equations

KAUST Repository

Ockendon, J. R.

2012-01-01

This paper concerns a certain class of two-dimensional solutions to four generic partial differential equations-the Helmholtz, modified Helmholtz, and convection-diffusion equations, and the heat conduction equation in the frequency domain-and the connections between these equations for this particular class of solutions.S pecifically, we consider thin-layer solutions, valid in narrow regions across which there is rapid variation, in the singularly perturbed limit as the coefficient of the Laplacian tends to zero.F or the wellstudied Helmholtz equation, this is the high-frequency limit and the solutions in question underpin the conventional ray theory/WKB approach in that they provide descriptions valid in some of the regions where these classical techniques fail.E xamples are caustics, shadow boundaries, whispering gallery, and creeping waves and focusing and bouncing ball modes.It transpires that virtually all such thin-layer models reduce to a class of generalized parabolic wave equations, of which the heat conduction equation is a special case. Moreover, in most situations, we will find that the appropriate parabolic wave equation solutions can be derived as limits of exact solutions of the Helmholtz equation.W e also show how reasonably well-understood thin-layer phenomena associated with any one of the four generic equations may translate into less well-known effects associated with the others.In addition, our considerations also shed some light on the relationship between the methods of matched asymptotic, WKB, and multiple-scales expansions. © 2012 Society for Industrial and Applied Mathematics.

Are gestational age, birth weight, and birth length indicators of favorable fetal growth conditions? A structural equation analysis of Filipino infants.

Science.gov (United States)

Bollen, Kenneth A; Noble, Mark D; Adair, Linda S

2013-07-30

The fetal origins hypothesis emphasizes the life-long health impacts of prenatal conditions. Birth weight, birth length, and gestational age are indicators of the fetal environment. However, these variables often have missing data and are subject to random and systematic errors caused by delays in measurement, differences in measurement instruments, and human error. With data from the Cebu (Philippines) Longitudinal Health and Nutrition Survey, we use structural equation models, to explore random and systematic errors in these birth outcome measures, to analyze how maternal characteristics relate to birth outcomes, and to take account of missing data. We assess whether birth weight, birth length, and gestational age are influenced by a single latent variable that we call favorable fetal growth conditions (FFGC) and if so, which variable is most closely related to FFGC. We find that a model with FFGC as a latent variable fits as well as a less parsimonious model that has birth weight, birth length, and gestational age as distinct individual variables. We also demonstrate that birth weight is more reliably measured than is gestational age. FFGCs were significantly influenced by taller maternal stature, better nutritional stores indexed by maternal arm fat and muscle area during pregnancy, higher birth order, avoidance of smoking, and maternal age 20-35 years. Effects of maternal characteristics on newborn weight, length, and gestational age were largely indirect, operating through FFGC. Copyright © 2013 John Wiley & Sons, Ltd.

Scaling Green-Kubo Relation and Application to Three Aging Systems

Directory of Open Access Journals (Sweden)

A. Dechant

2014-02-01

Full Text Available The Green-Kubo formula relates the spatial diffusion coefficient to the stationary velocity autocorrelation function. We derive a generalization of the Green-Kubo formula that is valid for systems with long-range or nonstationary correlations for which the standard approach is no longer valid. For the systems under consideration, the velocity autocorrelation function ⟨v(t+τv(t⟩ asymptotically exhibits a certain scaling behavior and the diffusion is anomalous, ⟨x^{2}(t⟩≃2D_{ν}t^{ν}. We show how both the anomalous diffusion coefficient D_{ν} and the exponent ν can be extracted from this scaling form. Our scaling Green-Kubo relation thus extends an important relation between transport properties and correlation functions to generic systems with scale-invariant dynamics. This includes stationary systems with slowly decaying power-law correlations, as well as aging systems, systems whose properties depend on the age of the system. Even for systems that are stationary in the long-time limit, we find that the long-time diffusive behavior can strongly depend on the initial preparation of the system. In these cases, the diffusivity D_{ν} is not unique, and we determine its values, respectively, for a stationary or nonstationary initial state. We discuss three applications of the scaling Green-Kubo relation: free diffusion with nonlinear friction corresponding to cold atoms diffusing in optical lattices, the fractional Langevin equation with external noise recently suggested to model active transport in cells, and the Lévy walk with numerous applications, in particular, blinking quantum dots. These examples underline the wide applicability of our approach, which is able to treat very different mechanisms of anomalous diffusion.

Development of kinetics equations from the Boltzmann equation; Etablissement des equations de la cinetique a partir de l'equation de Boltzmann

Energy Technology Data Exchange (ETDEWEB)

Plas, R.

1962-07-01

The author reports a study on kinetics equations for a reactor. He uses the conventional form of these equations but by using a dynamic multiplication factor. Thus, constants related to delayed neutrons are not modified by efficiency factors. The author first describes the theoretic kinetic operation of a reactor and develops the associated equations. He reports the development of equations for multiplication factors.

Generalization of the Biot--Savart law to Maxwell's equations using special relativity

International Nuclear Information System (INIS)

Neuenschwander, D.E.; Turner, B.N.

1992-01-01

Maxwell's equations are obtained by generalizing the laws of magnetostatics, which follow from the Biot--Savart law and superposition, to be consistent with special relativity. The Lorentz force on a charged particle and its rate of energy change also follow by making Newton's second law for a particle in a magnetostatic field consistent with special relativity

Men and mice: Relating their ages.

Science.gov (United States)

Dutta, Sulagna; Sengupta, Pallav

2016-05-01

Since the late 18th century, the murine model has been widely used in biomedical research (about 59% of total animals used) as it is compact, cost-effective, and easily available, conserving almost 99% of human genes and physiologically resembling humans. Despite the similarities, mice have a diminutive lifespan compared to humans. In this study, we found that one human year is equivalent to nine mice days, although this is not the case when comparing the lifespan of mice versus humans taking the entire life at the same time without considering each phase separately. Therefore, the precise correlation of age at every point in their lifespan must be determined. Determining the age relation between mice and humans is necessary for setting up experimental murine models more analogous in age to humans. Thus, more accuracy can be obtained in the research outcome for humans of a specific age group, although current outcomes are based on mice of an approximate age. To fill this gap between approximation and accuracy, this review article is the first to establish a precise relation between mice age and human age, following our previous article, which explained the relation in ages of laboratory rats with humans in detail. Copyright © 2015 Elsevier Inc. All rights reserved.

Bodacious Berry, Potency Wood and the Aging Monster: Gender and Age Relations in Anti-Aging Ads

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Calasanti, Toni

2007-01-01

This paper situates age discrimination within a broader system of age relations that intersects with other inequalities, and then uses that framework to analyze internet advertisements for the anti-aging industry. Such ads reinforce age and gender relations by positing old people as worthwhile only to the extent that they look and act like those…

The Age-Related Changes in Cartilage and Osteoarthritis

Directory of Open Access Journals (Sweden)

YongPing Li

2013-01-01

Full Text Available Osteoarthritis (OA is closely associated with aging, but its underlying mechanism is unclear. Recent publications were reviewed to elucidate the connection between aging and OA. With increasing OA incidence, more senior people are facing heavy financial and social burdens. Age-related OA pathogenesis is not well understood. Recently, it has been realized that age-related changes in other tissues besides articular cartilage may also contribute to OA development. Many factors including senescence-related secretory phenotypes, chondrocytes’ low reactivity to growth factors, mitochondrial dysfunction and oxidative stress, and abnormal accumulation of advanced glycation end products (AGEs may all play key roles in the pathogenesis of age-related OA. Lately, epigenetic regulation of gene expression was recognized for its impact on age-related OA pathogenesis. Up to now, few studies have been reported about the role of miRNA and long-noncoding RNA (lncRNA in age-related OA. Research focusing on this area may provide valuable insights into OA pathogenesis. OA-induced financial and social burdens have become an increasingly severe threat to older population. Age-related changes in noncartilage tissue should be incorporated in the understanding of OA development. Growing attention on oxidative stress and epigenetics will provide more important clues for the better understanding of the age-related OA.

A structural equation model relating impaired sensorimotor function, fear of falling and gait patterns in older people.

Science.gov (United States)

Menz, Hylton B; Lord, Stephen R; Fitzpatrick, Richard C

2007-02-01

Many falls in older people occur while walking, however the mechanisms responsible for gait instability are poorly understood. Therefore, the aim of this study was to develop a plausible model describing the relationships between impaired sensorimotor function, fear of falling and gait patterns in older people. Temporo-spatial gait parameters and acceleration patterns of the head and pelvis were obtained from 100 community-dwelling older people aged between 75 and 93 years while walking on an irregular walkway. A theoretical model was developed to explain the relationships between these variables, assuming that head stability is a primary output of the postural control system when walking. This model was then tested using structural equation modeling, a statistical technique which enables the testing of a set of regression equations simultaneously. The structural equation model indicated that: (i) reduced step length has a significant direct and indirect association with reduced head stability; (ii) impaired sensorimotor function is significantly associated with reduced head stability, but this effect is largely indirect, mediated by reduced step length, and; (iii) fear of falling is significantly associated with reduced step length, but has little direct influence on head stability. These findings provide useful insights into the possible mechanisms underlying gait characteristics and risk of falling in older people. Particularly important is the indication that fear-related step length shortening may be maladaptive.

Incentive relativity in middle aged rats.

Science.gov (United States)

Justel, N; Mustaca, A; Boccia, M; Ruetti, E

2014-01-24

Response to a reinforcer is affected by prior experience with different reward values of that reward, a phenomenon known as incentive relativity. Two different procedures to study this phenomenon are the incentive downshift (ID) and the consummatory anticipatory negative contrast (cANC), the former is an emotional-cognitive protocol and the latter cognitive one. Aged rodents, as also well described in aged humans, exhibit alterations in cognitive functions. The main goal of this work was to evaluate the effect of age in the incentive' assessment using these two procedures. The results indicated that aged rats had an adequate assessment of the rewards but their performance is not completely comparable to that of young subjects. They recover faster from the ID and they had a cognitive impairment in the cANC. The results are discussed in relation to age-related changes in memory and emotion. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Exact solutions and transformation properties of nonlinear partial differential equations from general relativity

International Nuclear Information System (INIS)

Fischer, E.

1977-01-01

Various families of exact solutions to the Einstein and Einstein--Maxwell field equations of general relativity are treated for situations of sufficient symmetry that only two independent variables arise. The mathematical problem then reduces to consideration of sets of two coupled nonlinear differential equations. The physical situations in which such equations arise include: the external gravitational field of an axisymmetric, uncharged steadily rotating body, cylindrical gravitational waves with two degrees of freedom, colliding plane gravitational waves, the external gravitational and electromagnetic fields of a static, charged axisymmetric body, and colliding plane electromagnetic and gravitational waves. Through the introduction of suitable potentials and coordinate transformations, a formalism is presented which treats all these problems simultaneously. These transformations and potentials may be used to generate new solutions to the Einstein--Maxwell equations from solutions to the vacuum Einstein equations, and vice-versa. The calculus of differential forms is used as a tool for generation of similarity solutions and generalized similarity solutions. It is further used to find the invariance group of the equations; this in turn leads to various finite transformations that give new, physically distinct solutions from old. Some of the above results are then generalized to the case of three independent variables

Further Generalization of Golden Mean in Relation to Euler Divine Equation

OpenAIRE

Rakocevic, Miloje M.

2006-01-01

In the paper a new generalization of the Golden mean, as a further generalization in relation to Stakhov (1989) and to Spinadel (1999), is presented. Also it is first observed that the Euler divine equation represents a possible generalization of Golden mean. In this second version the Section 6 is added.

Reference equations for handgrip strength: Normative values in young adult and middle-aged subjects.

Science.gov (United States)

Lopes, Jordão; Grams, Samantha Torres; da Silva, Edy Floriano; de Medeiros, Luana Adriano; de Brito, Christina May Moran; Yamaguti, Wellington Pereira

2018-06-01

Handgrip strength (HS) has been widely used as a functionality parameter of the upper limbs (UL) and general health. The measurement of HS by dynamometry is a low cost, non-invasive method of simple applicability, widely used in pulmonary rehabilitation and in critical care units. However, there are no reports in the literature of reference equations for the Brazilian population involving young and middle-aged adults. The aim of this study was to establish reference equations to predict normal HS for young and middle-aged adults through demographic and anthropometric data. This is a cross-sectional study with a sample of 80 healthy subjects (40 men and 40 women), aged 20-60 years. Inclusion criteria were: 1) BMI between 18.5 and 30 kg/m 2 ; 2) presence of dominant hand; 3) no cardiac, pulmonary, metabolic, or neurologic diseases; 4) lack of musculoskeletal disorders; 5) no history of fractures or trauma of the UL. Anthropometric measurements of the UL were obtained by a tape (hand length and width, forearm circumference and length). The dominance of hands was defined by the Dutch Handedness Questionnaire. HS measures were obtained by a manual hydraulic dynamometer, according to the recommendations of the American Association of Hand Therapists. Data were analyzed with SPSS for Windows, version 17.0, and treated with descriptive and inferential analysis. Normality was evaluated by Kolmogorov-Smirnov. Pearson or Spearman coefficients and multiple regression analysis were also used. HS was significantly higher for men compared to women, and also higher for the dominant hand (HSD) compared to the non-dominant hand (HSND) (p  0.05). No correlation was found between HS and age. A weak correlation was found between HS and BMI. A moderate correlation of HS was observed with weight and height. Finally, moderate and high correlations were found between HS and anthropometric variables of UL. The best reference equations with R 2 , adjusted to 0.71 and 0.70, were

Relation between visual function index and falls-related factors in patients with age-related cataract

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Mei-Na Huang

2016-01-01

Full Text Available AIM:To investigate the relation between vision function index and falls-related factors in patients with age-related cataract.METHODS:Ninety-six patients with age-related cataract were interviewed using a seven-item visual function questionnaire(VF-7, then classified into poor, moderate, or good visual function group. The differences of the three groups on visual acuity, balance and mobility function, cognition, depressive symptoms, self-reported fear of falling were analyzed. RESULTS:The patients in poor visual function group had older age, tendency to depression, was more afraid of falling, compared with groups with higher score in VF-7, and they had worse visual acuity, performed worse on all balance and mobility tests. CONCLUSION:Poor visual function is related to worse visual acuity, weaker balance and mobility performance in patients with age-related cataract. The VF-7, as a simple and convenient self-reported method, can be used as a falling risk monitoring in patients with age-related cataract.

Immunology of age-related macular degeneration

Science.gov (United States)

Ambati, Jayakrishna; Atkinson, John P.; Gelfand, Bradley D.

2014-01-01

Age-related macular degeneration (AMD) is a leading cause of blindness in aged individuals. Recent advances have highlighted the essential role of immune processes in the development, progression and treatment of AMD. In this Review we discuss recent discoveries related to the immunological aspects of AMD pathogenesis. We outline the diverse immune cell types, inflammatory activators and pathways that are involved. Finally, we discuss the future of inflammation-directed therapeutics to treat AMD in the growing aged population. PMID:23702979

Prediction equations for spirometry in adults from northern India.

Science.gov (United States)

Chhabra, S K; Kumar, R; Gupta, U; Rahman, M; Dash, D J

2014-01-01

Most of the Indian studies on prediction equations for spirometry in adults are several decades old and may have lost their utility as these were carried out with equipment and standardisation protocols that have since changed. Their validity is further questionable as the lung health of the population is likely to have changed over time. To develop prediction equations for spirometry in adults of north Indian origin using the 2005 American Thoracic Society/European Respiratory Society (ATS/ERS) recommendations on standardisation. Normal healthy non-smoker subjects, both males and females, aged 18 years and above underwent spirometry using a non-heated Fleisch Pneumotach spirometer calibrated daily. The dataset was randomly divided into training (70%) and test (30%) sets and the former was used to develop the equations. These were validated on the test data set. Prediction equations were developed separately for males and females for forced vital capacity (FVC), forced expiratory volume in first second (FEV1), FEV1/FVC ratio, and instantaneous expiratory flow rates using multiple linear regression procedure with different transformations of dependent and/or independent variables to achieve the best-fitting models for the data. The equations were compared with the previous ones developed in the same population in the 1960s. In all, 685 (489 males, 196 females) subjects performed spirometry that was technically acceptable and repeatable. All the spirometry parameters were significantly higher among males except the FEV1/FVC ratio that was significantly higher in females. Overall, age had a negative relationship with the spirometry parameters while height was positively correlated with each, except for the FEV1/FVC ratio that was related only to age. Weight was included in the models for FVC, forced expiratory flow (FEF75) and FEV1/FVC ratio in males, but its contribution was very small. Standard errors of estimate were provided to enable calculation of the lower

Evaluation of peak power prediction equations in male basketball players.

Science.gov (United States)

Duncan, Michael J; Lyons, Mark; Nevill, Alan M

2008-07-01

This study compared peak power estimated using 4 commonly used regression equations with actual peak power derived from force platform data in a group of adolescent basketball players. Twenty-five elite junior male basketball players (age, 16.5 +/- 0.5 years; mass, 74.2 +/- 11.8 kg; height, 181.8 +/- 8.1 cm) volunteered to participate in the study. Actual peak power was determined using a countermovement vertical jump on a force platform. Estimated peak power was determined using countermovement jump height and body mass. All 4 prediction equations were significantly related to actual peak power (all p jump prediction equations, 12% for the Canavan and Vescovi equation, and 6% for the Sayers countermovement jump equation. In all cases peak power was underestimated.

Age-Predicted Maximal Heart Rate in Recreational Marathon Runners: A Cross-Sectional Study on Fox's and Tanaka's Equations

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Pantelis T. Nikolaidis

2018-03-01

Full Text Available Age-based prediction equations of maximal heart rate (HRmax, such as the popular formulas Fox's 220-age, or Tanaka's 208-0.7 × age, have been widely used in various populations. Surprisingly, so far these equations have not been validated in marathon runners, despite the importance of the role of HRmax for training purposes in endurance running. The aim of the present study was to examine the validity of Fox and Tanaka equations in a large sample of women and men recreational marathon runners. Participants (n = 180, age 43.2 ± 8.5 years, VO2max 46.8 mL/min/kg, finishers in at least one marathon during the last year performed a graded exercise test on a treadmill, where HRmax was measured. Measured HRmax correlated largely with age in the total sample (r = −0.50, p < 0.001, women (r = −0.60, p < 0.001 and men (r = −0.53, p < 0.001. In women, a large main effect of method on HRmax (p = 0.001, η2 = 0.294 was shown with measured HRmax lower than Fox-HRmax (−4.8 bpm; −8.4, −1.3 and Tanaka-HRmax (−4.9 bpm; −8.1, −1.8. In men, a moderate effect of assessment method on HRmax was found (p = 0.001, η2 = 0.066 with measured HRmax higher than Fox-HRmax (+2.8; 1.0, 4.6, Tanaka-HRmax higher than Fox-HRmax (+1.2; 0.7, 1.7. Based on these findings, it was concluded that Fox and Tanaka' formulas overestimated HRmax by ~5 bpm in women, whereas Fox underestimated HRmax in men by ~3 bpm. Thus, we recommend the further use of Tanaka's formula in men marathon runners. In addition, exercise physiologists and sport scientists should consider the observed differences among various assessment methods when performing exercise testing or prescribing training program relying on HR.

Age-related hair pigment loss.

Science.gov (United States)

Tobin, Desmond J

2015-01-01

Humans are social animals that communicate disproportionately via potent genetic signals imbued in the skin and hair, including racial, ethnic, health, gender, and age status. For the vast majority of us, age-related hair pigment loss becomes the inescapable signal of our disappearing youth. The hair follicle (HF) pigmentary unit is a wonderful tissue for studying mechanisms generally regulating aging, often before this becomes evident elsewhere in the body. Given that follicular melanocytes (unlike those in the epidermis) are regulated by the hair growth cycle, this cycle is likely to impact the process of aging in the HF pigmentary unit. The formal identification of melanocyte stem cells in the mouse skin has spurred a flurry of reports on the potential involvement of melanocyte stem cell depletion in hair graying (i.e., canities). Caution is recommended, however, against simple extrapolation of murine data to humans. Regardless, hair graying in both species is likely to involve an age-related imbalance in the tissue's oxidative stress handling that will impact not only melanogenesis but also melanocyte stem cell and melanocyte homeostasis and survival. There is some emerging evidence that the HF pigmentary unit may have regenerative potential, even after it has begun to produce white hair fibers. It may therefore be feasible to develop strategies to modulate some aging-associated changes to maintain melanin production for longer. © 2015 S. Karger AG, Basel.

The relation between the kink-type solution and the kink-bell-type solution of nonlinear evolution equations

International Nuclear Information System (INIS)

Liu Chunping

2003-01-01

Using a direct algebraic method, more new exact solutions of the Kolmogorov-Petrovskii-Piskunov equation are presented by formula form. Then a theorem concerning the relation between the kink-type solution and the kink-bell-type solution of nonlinear evolution equations is given. Finally, the applications of the theorem to several well-known equations in physics are also discussed

The equationally-defined commutator a study in equational logic and algebra

CERN Document Server

Czelakowski, Janusz

2015-01-01

This monograph introduces and explores the notions of a commutator equation and the equationally-defined commutator from the perspective of abstract algebraic logic.  An account of the commutator operation associated with equational deductive systems is presented, with an emphasis placed on logical aspects of the commutator for equational systems determined by quasivarieties of algebras.  The author discusses the general properties of the equationally-defined commutator, various centralization relations for relative congruences, the additivity and correspondence properties of the equationally-defined commutator, and its behavior in finitely generated quasivarieties. Presenting new and original research not yet considered in the mathematical literature, The Equationally-Defined Commutator will be of interest to professional algebraists and logicians, as well as graduate students and other researchers interested in problems of modern algebraic logic.

On some functional equations related to Steffensen's inequality

Directory of Open Access Journals (Sweden)

Bogdan Choczewski

2004-05-01

Full Text Available We consider the problem, proposed by the second author (cf. [1] of solving functional equations stemming from the Steffensen integral inequality (S, which is applicable in actuarial problems, cf. [4]. Imposing some regularity conditions we find solutions of two equations in two variables, one with two and another with three unknown functions.

Feynman path integral related to stochastic schroedinger equation

International Nuclear Information System (INIS)

Belavkin, V.P.; Smolyanov, O.G.

1998-01-01

The derivation of the Schroedinger equation describing the continuous measurement process is presented. The representation of the solution of the stochastic Schroedinger equation for continuous measurements is obtained by means of the Feynman path integral. The connection with the heuristic approach to the description of continuous measurements is considered. The connection with the Senon paradox is established [ru

Work Ability: using structural equation modeling to assess the effects of aging, health and work on the population of Brazilian municipal employees.

Science.gov (United States)

Alcântara, Marcus A; Sampaio, Rosana F; Assunção, Ada Ávila; Silva, Fabiana C Martins

2014-01-01

The Work Ability Model has a holistic structure that incorporates individual characteristics, work-related factors and life outside of work. The model has been explored in the context of Finland but still needs to be applied in other countries. The aim of this study was to examine the relationships between age, health, work and work ability in a sample of Brazilian municipal employees. A sample of 5,646 workers answered a web-survey questionnaire that collected information about socio-demographics, health, work characteristics and work ability. Structural equation modeling (SEM) was used to examine the simultaneous relationships between the variables that comprise the Work Ability Model. The sample was predominantly female (68.0%), between 30 and 49 years old (60.0%) and highly educated (66.0%). SEM produced good fit indexes that supported the Work Ability Model. Age was positively related to work ability and negatively related to health. Health and work characteristics positively influenced work ability. The results produced additional support for the conceptualization of work ability as a complex and dynamic phenomenon: a system composed of an individual and various elements of his/her work interact in time and space in a nonlinear way.

A review of some basic aspects related to integration of airplane’s equations of motion

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Dan TURCANU

2017-09-01

Full Text Available Numerical integration of the airplane’s equations of motion has long been considered among the most fundamental calculations in airplane’s analysis. Numerical algorithms have been implemented and experimentally validated. However, the need for superior speed and accuracy is still very topical, as, nowadays, various optimization algorithms rely heavily on data generated from the integration of the equations of motion and having access to larger amounts of data can increase the quality of the optimization. Now, for a number of decades, engineers have relied heavily on commercial codes based on automatically selected integration steps. However, optimally chosen constant integration steps can save time and allows for larger numbers of integrations to be performed. Yet, the basic papers that presented the fundamentals of numerical integration, as applied to airplane’s equations of motion are nowadays not easy to locate. Consequently, this paper presents a review of basic aspects related to the integration of airplane’s equation of motion. The discussion covers fundamentals of longitudinal and lateral-directional motion as well as the implementation of some numerical integration methods. The relation between numerical integration steps, accuracy, computational resource usage, numerical stability and their relation with the parameters describing the dynamic response of the airplane is considered and suggestions are presented for a faster yet accurate numerical integration.

A Comparison between Linear IRT Observed-Score Equating and Levine Observed-Score Equating under the Generalized Kernel Equating Framework

Science.gov (United States)

Chen, Haiwen

2012-01-01

In this article, linear item response theory (IRT) observed-score equating is compared under a generalized kernel equating framework with Levine observed-score equating for nonequivalent groups with anchor test design. Interestingly, these two equating methods are closely related despite being based on different methodologies. Specifically, when…

Intertwining relations and Darboux transformations for Schroedinger equations in (n+1) dimensions

International Nuclear Information System (INIS)

Schulze-Halberg, Axel

2010-01-01

We evaluate the intertwining relation for Schroedinger equations in (n+1) dimensions. The conditions for the existence of a Darboux transformation are analyzed and compared to their (1+1) dimensional counterparts. A complete solution of the conditions is given for (2+1) dimensions, and a Darboux transformation is constructed.

State-dependent neutral delay equations from population dynamics.

Science.gov (United States)

Barbarossa, M V; Hadeler, K P; Kuttler, C

2014-10-01

A novel class of state-dependent delay equations is derived from the balance laws of age-structured population dynamics, assuming that birth rates and death rates, as functions of age, are piece-wise constant and that the length of the juvenile phase depends on the total adult population size. The resulting class of equations includes also neutral delay equations. All these equations are very different from the standard delay equations with state-dependent delay since the balance laws require non-linear correction factors. These equations can be written as systems for two variables consisting of an ordinary differential equation (ODE) and a generalized shift, a form suitable for numerical calculations. It is shown that the neutral equation (and the corresponding ODE--shift system) is a limiting case of a system of two standard delay equations.

Beyond chronological age: examining time and health as age-related mediators in relations to work motives

NARCIS (Netherlands)

Kooij, T.A.M.; de Lange, A.H.; Jansen, P.G.W.; Dikkers, J.S.E.

2013-01-01

Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

Periodic Sturm-Liouville problems related to two Riccati equations of constant coefficients

International Nuclear Information System (INIS)

Khmelnytskaya, K.V.; Rosu, H.C.; Gonzalez, A.

2010-01-01

We consider two closely related Riccati equations of constant parameters whose particular solutions are used to construct the corresponding class of supersymmetrically coupled second-order differential equations. We solve analytically these parametric periodic problems along the whole real axis. Next, the analytically solved model is used as a case study for a powerful numerical approach that is employed here for the first time in the investigation of the energy band structure of periodic not necessarily regular potentials. The approach is based on the well-known self-matching procedure of James (1949) and implements the spectral parameter power series solutions introduced by Kravchenko (2008). We obtain additionally an efficient series representation of the Hill discriminant based on Kravchenko's series.

The Reduction of Chazy Classes and Other Third-Order Differential Equations Related to Boundary Layer Flow Models

International Nuclear Information System (INIS)

Fakhar, K.; Kara, A. H.

2012-01-01

We study the symmetries, conservation laws and reduction of third-order equations that evolve from a prior reduction of models that arise in fluid phenomena. These could be the ordinary differential equations (ODEs) that are reductions of partial differential equations (PDEs) or, alternatively, PDEs related to given ODEs. In this class, the analysis includes the well-known Blasius, Chazy, and other associated third-order ODEs. (general)

Age-Related Differences in Multiple Task Monitoring

OpenAIRE

Todorov, Ivo; Del Missier, Fabio; Mäntylä, Timo

2014-01-01

Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men excee...

The application of information theory for the research of aging and aging-related diseases.

Science.gov (United States)

Blokh, David; Stambler, Ilia

2017-10-01

This article reviews the application of information-theoretical analysis, employing measures of entropy and mutual information, for the study of aging and aging-related diseases. The research of aging and aging-related diseases is particularly suitable for the application of information theory methods, as aging processes and related diseases are multi-parametric, with continuous parameters coexisting alongside discrete parameters, and with the relations between the parameters being as a rule non-linear. Information theory provides unique analytical capabilities for the solution of such problems, with unique advantages over common linear biostatistics. Among the age-related diseases, information theory has been used in the study of neurodegenerative diseases (particularly using EEG time series for diagnosis and prediction), cancer (particularly for establishing individual and combined cancer biomarkers), diabetes (mainly utilizing mutual information to characterize the diseased and aging states), and heart disease (mainly for the analysis of heart rate variability). Few works have employed information theory for the analysis of general aging processes and frailty, as underlying determinants and possible early preclinical diagnostic measures for aging-related diseases. Generally, the use of information-theoretical analysis permits not only establishing the (non-linear) correlations between diagnostic or therapeutic parameters of interest, but may also provide a theoretical insight into the nature of aging and related diseases by establishing the measures of variability, adaptation, regulation or homeostasis, within a system of interest. It may be hoped that the increased use of such measures in research may considerably increase diagnostic and therapeutic capabilities and the fundamental theoretical mathematical understanding of aging and disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Age-related differences in multiple task monitoring.

Science.gov (United States)

Todorov, Ivo; Del Missier, Fabio; Mäntylä, Timo

2014-01-01

Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men exceeded women in multitasking, measured as monitoring accuracy. Individual differences in executive functioning and spatial ability were independent predictors of young adults' monitoring accuracy, but only spatial ability was related to sex differences. For older adults, age and executive functioning, but not spatial ability, predicted multitasking performance. These results suggest that executive functions contribute to multiple task performance across the adult life span and that reliance on spatial skills for coordinating deadlines is modulated by age.

Age-related differences in multiple task monitoring.

Directory of Open Access Journals (Sweden)

Ivo Todorov

Full Text Available Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men exceeded women in multitasking, measured as monitoring accuracy. Individual differences in executive functioning and spatial ability were independent predictors of young adults' monitoring accuracy, but only spatial ability was related to sex differences. For older adults, age and executive functioning, but not spatial ability, predicted multitasking performance. These results suggest that executive functions contribute to multiple task performance across the adult life span and that reliance on spatial skills for coordinating deadlines is modulated by age.

Relations between the kinetic equation and the Langevin models in two-phase flow modelling

International Nuclear Information System (INIS)

Minier, J.P.; Pozorski, J.

1997-05-01

The purpose of this paper is to discuss PDF and stochastic models which are used in two-phase flow modelling. The aim of the present analysis is essentially to try to determine relations and consistency between different models. It is first recalled that different approaches actually correspond to PDF models written either in terms of the process trajectories or in terms of the PDF itself. The main difference lies in the choice of the independent variables which are retained. Two particular models are studied, the Kinetic Equation and the Langevin Equation model. The latter uses a Langevin equation to model the fluid velocities seen along particle trajectories. The Langevin model is more general since it contains an additional variable. It is shown that, in certain cases, this variable can be summed up exactly to retrieve the Kinetic Equation model as a marginal PDF. A joint fluid and solid particle PDF which includes the characteristics of both phases is proposed at the end of the paper. (author)

Age-related changes in mastication.

Science.gov (United States)

Peyron, M A; Woda, A; Bourdiol, P; Hennequin, M

2017-04-01

The paper reviews human mastication, focusing on its age-related changes. The first part describes mastication adaptation in young healthy individuals. Adaptation to obtain a food bolus ready to be swallowed relies on variations in number of cycles, muscle strength and volume of emitted saliva. As a result, the food bolus displays granulometric and rheological properties, the values of which are maintained within the adaptive range of deglutition. The second part concerns healthy ageing. Some mastication parameters are slightly modified by age, but ageing itself does not impair mastication, as the adaptation possibilities remain operant. The third part reports on very aged subjects, who display frequent systemic or local diseases. Local and/or general diseases such as tooth loss, salivary defect, or motor impairment are then indistinguishably superimposed on the effects of very old age. The resulting impaired function increases the risk of aspiration and choking. Lastly, the consequences for eating behaviour and nutrition are evoked. © 2016 John Wiley & Sons Ltd.

Differential age-related effects on conjunctive and relational visual short-term memory binding.

Science.gov (United States)

Bastin, Christine

2017-12-28

An age-related associative deficit has been described in visual short-term binding memory tasks. However, separate studies have suggested that ageing disrupts relational binding (to associate distinct items or item and context) more than conjunctive binding (to integrate features within an object). The current study directly compared relational and conjunctive binding with a short-term memory task for object-colour associations in 30 young and 30 older adults. Participants studied a number of object-colour associations corresponding to their individual object span level in a relational task in which objects were associated to colour patches and a conjunctive task where colour was integrated into the object. Memory for individual items and for associations was tested with a recognition memory test. Evidence for an age-related associative deficit was observed in the relational binding task, but not in the conjunctive binding task. This differential impact of ageing on relational and conjunctive short-term binding is discussed by reference to two underlying age-related cognitive difficulties: diminished hippocampally dependent binding and attentional resources.

Investigating the Theoretical Structure of the DAS-II Core Battery at School Age Using Bayesian Structural Equation Modeling

Science.gov (United States)

Dombrowski, Stefan C.; Golay, Philippe; McGill, Ryan J.; Canivez, Gary L.

2018-01-01

Bayesian structural equation modeling (BSEM) was used to investigate the latent structure of the Differential Ability Scales-Second Edition core battery using the standardization sample normative data for ages 7-17. Results revealed plausibility of a three-factor model, consistent with publisher theory, expressed as either a higher-order (HO) or a…

Impacts of age-related failures on nuclear systems

International Nuclear Information System (INIS)

Meale, B.M.; Satterwhite, D.G.; Krantz, E.A.; MacDonald, P.E.

1986-01-01

Aging-related failure data from nine light water reactor safety, support, and power conversion systems have been extracted from an operational data base. Systems and components within the systems that are most affected by aging are identified. In addition, information on aging-related root causes of component failures has been extracted for service water and Class 1E electrical power distribution systems. Engineering insights are presented, and preliminary quantification of the importance of aging-related root causes for a service water system is provided

Age-related Deterioration of Hematopoietic Stem Cells.

Science.gov (United States)

Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

2008-11-01

Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the effects of aging on stem cell functions are inconclusive. Here we review the age-related properties of hematopoietic stem cells in terms of intrinsic and extrinsic alterations, proliferative potential, signaling molecules, telomere and telomerase, senescence and cancer issues, regenerative potential and other indications of stem cell aging are discussed in detail.

The Digital Ageing Atlas: integrating the diversity of age-related changes into a unified resource.

Science.gov (United States)

Craig, Thomas; Smelick, Chris; Tacutu, Robi; Wuttke, Daniel; Wood, Shona H; Stanley, Henry; Janssens, Georges; Savitskaya, Ekaterina; Moskalev, Alexey; Arking, Robert; de Magalhães, João Pedro

2015-01-01

Multiple studies characterizing the human ageing phenotype have been conducted for decades. However, there is no centralized resource in which data on multiple age-related changes are collated. Currently, researchers must consult several sources, including primary publications, in order to obtain age-related data at various levels. To address this and facilitate integrative, system-level studies of ageing we developed the Digital Ageing Atlas (DAA). The DAA is a one-stop collection of human age-related data covering different biological levels (molecular, cellular, physiological, psychological and pathological) that is freely available online (http://ageing-map.org/). Each of the >3000 age-related changes is associated with a specific tissue and has its own page displaying a variety of information, including at least one reference. Age-related changes can also be linked to each other in hierarchical trees to represent different types of relationships. In addition, we developed an intuitive and user-friendly interface that allows searching, browsing and retrieving information in an integrated and interactive fashion. Overall, the DAA offers a new approach to systemizing ageing resources, providing a manually-curated and readily accessible source of age-related changes. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion

International Nuclear Information System (INIS)

Zhang Mei-Ling; Wang Xiao-Xiao; Xie Yin-Li; Jia Li-Qun; Sun Xian-Ting

2011-01-01

Lie symmetry and the generalized Hojman conserved quantity of Nielsen equations for a variable mass holonomic system of relative motion are studied. The determining equation of Lie symmetry of Nielsen equations for a variable mass holonomic system of relative motion under the infinitesimal transformations of groups is given. The expression of generalized Hojman conserved quantity deduced directly from Lie symmetry for a variable mass holonomic system of relative motion is obtained. An example is given to illustrate the application of the results. (general)

Risk factors of age-related macular degeneration in Argentina

Directory of Open Access Journals (Sweden)

María Eugenia Nano

2013-04-01

Full Text Available PURPOSES: To assess the risk factors of age-related macular degeneration in Argentina using a case-control study. METHODS: Surveys were used for subjects' antioxidant intake, age/gender, race, body mass index, hypertension, diabetes (and type of treatment, smoking, sunlight exposure, red meat consumption, fish consumption, presence of age-related macular degeneration and family history of age-related macular degeneration. Main effects models for logistic regression and ordinal logistic regression were used to analyze the results. RESULTS: There were 175 cases and 175 controls with a mean age of 75.4 years and 75.5 years, respectively, of whom 236 (67.4% were female. Of the cases with age-related macular degeneration, 159 (45.4% had age-related macular degeneration in their left eyes, 154 (44.0% in their right eyes, and 138 (39.4% in both eyes. Of the cases with age-related macular degeneration in their left eyes, 47.8% had the dry type, 40.3% had the wet type, and the type was unknown for 11.9%. The comparable figures for right eyes were: 51.9%, 34.4%, and 13.7%, respectively. The main effects model was dominated by higher sunlight exposure (OR [odds ratio]: 3.3 and a family history of age-related macular degeneration (OR: 4.3. Other factors included hypertension (OR: 2.1, smoking (OR: 2.2, and being of the Mestizo race, which lowered the risk of age-related macular degeneration (OR: 0.40. Red meat/fish consumption, body mass index, and iris color did not have an effect. Higher age was associated with progression to more severe age-related macular degeneration. CONCLUSION: Sunlight exposure, family history of age-related macular degeneration, and an older age were the significant risk factors. There may be other variables, as the risk was not explained very well by the existing factors. A larger sample may produce different and better results.

Integral equations

CERN Document Server

Moiseiwitsch, B L

2005-01-01

Two distinct but related approaches hold the solutions to many mathematical problems--the forms of expression known as differential and integral equations. The method employed by the integral equation approach specifically includes the boundary conditions, which confers a valuable advantage. In addition, the integral equation approach leads naturally to the solution of the problem--under suitable conditions--in the form of an infinite series.Geared toward upper-level undergraduate students, this text focuses chiefly upon linear integral equations. It begins with a straightforward account, acco

Heritability of Age-Related Hearing Loss in Middle-Aged and Elderly Chinese

DEFF Research Database (Denmark)

Duan, Haiping; Zhang, Dongfeng; Liang, Yajun

2018-01-01

OBJECTIVES: The heritability of age-related hearing loss has been studied mostly in developed countries. The authors aimed to estimate the heritability of better ear hearing level (BEHL), defined as hearing level of the better ear at a given frequency, and pure-tone averages at the middle (0.5, 1.......0, and 2.0 kHz) and high (4.0, 8.0, and 12.5 kHz) frequencies among middle-aged and elderly Chinese twins, and to explore their genetic correlations. DESIGN: This population-based twin study included 226 monozygotic and 132 dizygotic twin-pairs and 1 triplet (age range, 33 to 80 years; mean age, 51.......75 at high frequencies. CONCLUSIONS: This population-based twin study suggests that genetic factors are associated with age-related hearing loss at middle and high frequencies among middle-aged and elderly Chinese....

CREB Overexpression Ameliorates Age-related Behavioral and Biophysical Deficits

Science.gov (United States)

Yu, Xiao-Wen

Age-related cognitive deficits are observed in both humans and animals. Yet, the molecular mechanisms underlying these deficits are not yet fully elucidated. In aged animals, a decrease in intrinsic excitability of pyramidal neurons from the CA1 sub-region of hippocampus is believed to contribute to age-related cognitive impairments, but the molecular mechanism(s) that modulate both these factors has yet to be identified. Increasing activity of the transcription factor cAMP response element-binding protein (CREB) in young adult rodents has been shown to facilitate cognition, and increase intrinsic excitability of their neurons. However, how CREB changes with age, and how that impacts cognition in aged animals, is not clear. Therefore, we first systematically characterized age- and training-related changes in CREB levels in dorsal hippocampus. At a remote time point after undergoing behavioral training, levels of total CREB and activated CREB (phosphorylated at S133, pCREB) were measured in both young and aged rats. We found that pCREB, but not total CREB was significantly reduced in dorsal CA1 of aged rats. Importantly, levels of pCREB were found to be positively correlated with short-term spatial memory in both young and aged rats i.e. higher pCREB in dorsal CA1 was associated with better spatial memory. These findings indicate that an age-related deficit in CREB activity may contribute to the development of age-related cognitive deficits. However, it was still unclear if increasing CREB activity would be sufficient to ameliorate age-related cognitive, and biophysical deficits. To address this question, we virally overexpressed CREB in CA1, where we found the age-related deficit. Young and aged rats received control or CREB virus, and underwent water maze training. While control aged animals exhibited deficits in long-term spatial memory, aged animals with CREB overexpression performed at levels comparable to young animals. Concurrently, aged neurons

Age-Related Macular Degeneration.

Science.gov (United States)

Mehta, Sonia

2015-09-01

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. AMD is diagnosed based on characteristic retinal findings in individuals older than 50. Early detection and treatment are critical in increasing the likelihood of retaining good and functional vision. Copyright © 2015 Elsevier Inc. All rights reserved.

Relation of Obesity and Menarche Age among

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Shila Berenjy

2008-12-01

Full Text Available Objective: The aim of this study was to investigate the relation between overweight and obesity among adolescent students and age of menarche.Materials and Methods: In a cross-sectional study 399 urban adolescent girls aged 11-14 years old were selected from schools of Kermanshah city in Iran. Anthropometric examinations including, triceps skin fold (TSF, mid arm circumference (MAC, body fat percentage (BF %, were measured and information on age of menarch and student’s demographics were collected. Results: The results showed that age, body mass index (BMI and menarche age were:12.63+1.01 year, 17.71+2.94 kg/m2 and 12.16+1.18 year respectively. Prevalence of overweight in respondents was 23.2%, however; prevalence of obesity was 23.2% for 11 years old , 22.4% for12 years olds , 24% of 13 years old  and 23.5% of 14 years old. Conclusion: There was a reverse relation  between BMI and age of menarche, however; it was not significant (p>0.1. This study suggests a high prevalence of obesity and relation between BMI and anthropometric parameters in adolesent girls.

Age-Related Declines in Early Sensory Memory: Identification of Rapid Auditory and Visual Stimulus Sequences.

Science.gov (United States)

Fogerty, Daniel; Humes, Larry E; Busey, Thomas A

2016-01-01

Age-related temporal-processing declines of rapidly presented sequences may involve contributions of sensory memory. This study investigated recall for rapidly presented auditory (vowel) and visual (letter) sequences presented at six different stimulus onset asynchronies (SOA) that spanned threshold SOAs for sequence identification. Younger, middle-aged, and older adults participated in all tasks. Results were investigated at both equivalent performance levels (i.e., SOA threshold) and at identical physical stimulus values (i.e., SOAs). For four-item sequences, results demonstrated best performance for the first and last items in the auditory sequences, but only the first item for visual sequences. For two-item sequences, adults identified the second vowel or letter significantly better than the first. Overall, when temporal-order performance was equated for each individual by testing at SOA thresholds, recall accuracy for each position across the age groups was highly similar. These results suggest that modality-specific processing declines of older adults primarily determine temporal-order performance for rapid sequences. However, there is some evidence for a second amodal processing decline in older adults related to early sensory memory for final items in a sequence. This selective deficit was observed particularly for longer sequence lengths and was not accounted for by temporal masking.

Age-related patterns in work-related injury claims from older New Zealanders, 2009-2013: Implications of injury for an aging workforce.

Science.gov (United States)

Lilley, Rebbecca; Jaye, Chrystal; Davie, Gabrielle; Keeling, Sally; Waters, Debra; Egan, Richard

2018-01-01

This study describes the incidence, nature and cause of work-related injuries in older New Zealand workers to understand the risks of work-related injury in this rapidly aging population. Data for the period 2009-2013 from 25,455 injured workers aged 55-79 years, extracted from national work-related injury entitlement claims, were stratified by age group and analysed by sex, industry, injury type and cause. Age-specific claims rates were calculated by year, sex and ethnicity. Patterns of injury differed by age: 70-79 year olds had the highest injury rates and proportion of claims due to falls (45%), for the self-employed (32%), for the agriculture sector (24%), and for fatal injuries (5%). The burden of work-related injuries in older workers, particularly in those aged over 70, will increase with their increasing participation in work. Workplace injury prevention strategies and interventions need to consider the specific characteristics and vulnerabilities of older workers. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Generalized Analytic Operator-Valued Function Space Integral and a Related Integral Equation

International Nuclear Information System (INIS)

Chang, K.S.; Kim, B.S.; Park, C.H.; Ryu, K.S.

2003-01-01

We introduce a generalized Wiener measure associated with a Gaussian Markov process and define a generalized analytic operator-valued function space integral as a bounded linear operator from L p into L p-ci r cumflexprime (1< p ≤ 2) by the analytic continuation of the generalized Wiener integral. We prove the existence of the integral for certain functionals which involve some Borel measures. Also we show that the generalized analytic operator-valued function space integral satisfies an integral equation related to the generalized Schroedinger equation. The resulting theorems extend the theory of operator-valued function space integrals substantially and previous theorems about these integrals are generalized by our results

The Female Stroke Survival Advantage: Relation to Age

DEFF Research Database (Denmark)

Olsen, Tom Skyhøj; Dehlendorff, Christian; Andersen, Klaus Kaae

2009-01-01

Background: Age-related hormonal factors are thought to be related to the gender gap in longevity. Testing the hypothesis that survival is best in young premenopausal women we studied the effect of age on 1-week mortality in stroke patients. Methods: A registry was started in 2001 with the aim...... in women. While mortality increased almost linearly in women over the entire age range, it increased steeply in men from the age of 50 and at the age of 80 years survival was 80% better in women. Conclusion: The female stroke survival advantage applies to all ages. It increases with age due to a steeply...

Prevalence of age-related macular degeneration in elderly Caucasians

DEFF Research Database (Denmark)

Erke, Maja G; Bertelsen, Geir; Peto, Tunde

2012-01-01

To describe the sex- and age-specific prevalence of drusen, geographic atrophy, and neovascular age-related macular degeneration (AMD).......To describe the sex- and age-specific prevalence of drusen, geographic atrophy, and neovascular age-related macular degeneration (AMD)....

Validity of predictive equations for basal metabolic rate in Japanese adults.

Science.gov (United States)

Miyake, Rieko; Tanaka, Shigeho; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Hikihara, Yuki; Taguri, Emiko; Kayashita, Jun; Tabata, Izumi

2011-01-01

Many predictive equations for basal metabolic rate (BMR) based on anthropometric measurements, age, and sex have been developed, mainly for healthy Caucasians. However, it has been reported that many of these equations, used widely, overestimate BMR not only for Asians, but also for Caucasians. The present study examined the accuracy of several predictive equations for BMR in Japanese subjects. In 365 healthy Japanese male and female subjects, aged 18 to 79 y, BMR was measured in the post-absorptive state using a mask and Douglas bag. Six predictive equations were examined. Total error was used as an index of the accuracy of each equation's prediction. Predicted BMR values by Dietary Reference Intakes for Japanese (Japan-DRI), Adjusted Dietary Reference Intakes for Japanese (Adjusted-DRI), and Ganpule equations were not significantly different from the measured BMR in either sex. On the other hand, Harris-Benedict, Schofield, and Food and Agriculture Organization of the United Nations/World Health Organization/United Nations University equations were significantly higher than the measured BMR in both sexes. The prediction error by Japan-DRI, Adjusted-DRI, and Harris-Benedict equations was significantly correlated with body weight in both sexes. Total error using the Ganpule equation was low in both males and females (125 and 99 kcal/d, respectively). In addition, total error using the Adjusted-DRI equation was low in females (95 kcal/d). Thus, the Ganpule equation was the most accurate in predicting BMR in our healthy Japanese subjects, because the difference between the predicted and measured BMR was relatively small, and body weight had no effect on the prediction error.

Age-related decline in global form suppression

DEFF Research Database (Denmark)

Wiegand, Iris Michaela; Finke, Kathrin; Töllner, Thomas

2015-01-01

. Selective attention, i.e., the ability to focus on relevant and ignore irrelevant information, declines with increasing age; however, how this deficit affects selection of global vs. local configurations remains unknown. On this background, the present study examined for age-related differences in a global...... differences in the subsequent (250–500 ms) posterior contralateral negativity (PCN) indicated that attentional resources were allocated faster to Kanisza, as compared to non-Kanisza, targets in both age groups, while the allocation of spatial attention seemed to be generally delayed in older relative...... to younger age. Our results suggest that the enhanced global-local asymmetry in the older age group originated from less effective suppression of global distracter forms on early processing stages – indicative of older observers having difficulties with disengaging from a global default selection mode...

Transient Relative Age Effects across annual age groups in National level Australian Swimming.

Science.gov (United States)

Cobley, Stephen; Abbott, Shaun; Dogramaci, Sera; Kable, Adam; Salter, James; Hintermann, Mirjam; Romann, Michael

2017-12-29

To determine the prevalence, magnitude and transient patterning of Relative Age Effects (RAEs) according to sex and stroke event across all age-groups at the Australian National age swimming Championships. Repeated years of cross-sectional participation data were examined. Participants were 6014 unique male (3185) and female (2829) swimmers (aged 12-18 years) who participated in Freestyle (50, 400m) and/or Breaststroke (100, 200m) at the National age swimming Championships between 2000-2014 (inclusive). RAE prevalence, magnitude and transience were determined using Chi-square tests and Cramer's V estimates for effect size. Odds Ratios (OR) and 95% Confidence Intervals (CI) examined relative age quartile discrepancies. These steps were applied across age-groups and according to sex and each stroke event. Consistent RAEs with large-medium effect sizes were evident for males at 12-15 years of age respectively, and with large-medium effects for females at 12-14 respectively across all four swimming strokes. RAE magnitude then consistently reduced with age across strokes (e.g., Q1 vs. Q4 OR range 16year old males=0.94-1.20; females=0.68-1.41). With few exceptions, by 15-16 years RAEs had typically dissipated; and by 17-18 years, descriptive and significant inverse RAEs emerged, reflecting overrepresentation of relatively younger swimmers. Performance advantages associated with relative age (and thereby likely growth and maturation) are transient. Greater consideration of transient performance and participation in athlete development systems is necessary. This may include revising the emphasis of sport programmes according to developmental stages and delaying forms of athlete selection to improve validity. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Thalamic structures and associated cognitive functions: Relations with age and aging

Science.gov (United States)

Fama, Rosemary; Sullivan, Edith V.

2015-01-01

The thalamus, with its cortical, subcortical, and cerebellar connections, is a critical node in networks supporting cognitive functions known to decline in normal aging, including component processes of memory and executive functions of attention and information processing. The macrostructure, microstructure, and neural connectivity of the thalamus changes across the adult lifespan. Structural and functional magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) have demonstrated, regional thalamic volume shrinkage and microstructural degradation, with anterior regions generally more compromised than posterior regions. The integrity of selective thalamic nuclei and projections decline with advancing age, particularly those in thalamofrontal, thalamoparietal, and thalamolimbic networks. This review presents studies that assess the relations between age and aging and the structure, function, and connectivity of the thalamus and associated neural networks and focuses on their relations with processes of attention, speed of information processing, and working and episodic memory. PMID:25862940

Age-ordered shirt numbering reduces the selection bias associated with the relative age effect.

Science.gov (United States)

Mann, David L; van Ginneken, Pleun J M A

2017-04-01

When placed into age groups for junior sporting competition, the relative differences in age between children leads to a bias in who is evaluated as being talented. While the impact of this relative age effect (RAE) is clear, until now there has been no evidence to show how to reduce it. The aim of this study was to determine whether the selection bias associated with the RAE could be reduced. Talent scouts from an elite football club watched junior games and ranked players on the basis of their potential. Scouts were allocated to one of three groups provided with contrasting information about the age of the players: (1) no age information, (2) players' birthdates or (3) knowledge that the numbers on the playing shirts corresponded to the relative age of the players. Results revealed a significant selection bias for the scouts in the no-age information group, and that bias remained when scouts knew the players' dates-of-birth. Strikingly though, the selection bias was eliminated when scouts watched the games knowing the shirt numbers corresponded to the relative ages of the players. The selection bias associated with the RAE can be reduced if information about age is presented appropriately.

Reduction of lattice equations to the Painlevé equations: PIV and PV

Science.gov (United States)

Nakazono, Nobutaka

2018-02-01

In this paper, we construct a new relation between Adler-Bobenko-Suris equations and Painlevé equations. Moreover, using this connection we construct the difference-differential Lax representations of the fourth and fifth Painlevé equations.

Vocabulary test format and differential relations to age.

Science.gov (United States)

Bowles, Ryan P; Salthouse, Timothy A

2008-06-01

Although vocabulary tests are generally considered interchangeable, regardless of format, different tests can have different relations to age and to other cognitive abilities. In this study, 4 vocabulary test formats were examined: multiple-choice synonyms, multiple-choice antonyms, produce the definition, and picture identification. Results indicated that, although they form a single coherent vocabulary knowledge factor, the formats have different relations to age. In earlier adulthood, picture identification had the strongest growth, and produce the definition had the weakest. In later adulthood, picture identification had the strongest decline, and multiple-choice synonyms had the least. The formats differed in their relation to other cognitive variables, including reasoning, spatial visualization, memory, and speed. After accounting for the differential relations to other cognitive variables, differences in relation to age were eliminated with the exception of differences for the picture identification test. No theory of the aging of vocabulary knowledge fully explains these findings. These results suggest that using a single indicator of vocabulary may yield incomplete and somewhat misleading results about the aging of vocabulary knowledge.

Cause and effect analysis by fuzzy relational equations and a genetic algorithm

International Nuclear Information System (INIS)

Rotshtein, Alexander P.; Posner, Morton; Rakytyanska, Hanna B.

2006-01-01

This paper proposes using a genetic algorithm as a tool to solve the fault diagnosis problem. The fault diagnosis problem is based on a cause and effect analysis which is formally described by fuzzy relations. Fuzzy relations are formed on the basis of expert assessments. Application of expert fuzzy relations to restore and identify the causes through the observed effects requires the solution to a system of fuzzy relational equations. In this study this search for a solution amounts to solving a corresponding optimization problem. An optimization algorithm is based on the application of genetic operations of crossover, mutation and selection. The genetic algorithm suggested here represents an application in expert systems of fault diagnosis and quality control

Some Mathematical Structures Including Simplified Non-Relativistic Quantum Teleportation Equations and Special Relativity

International Nuclear Information System (INIS)

Woesler, Richard

2007-01-01

The computations of the present text with non-relativistic quantum teleportation equations and special relativity are totally speculative, physically correct computations can be done using quantum field theory, which remain to be done in future. Proposals for what might be called statistical time loop experiments with, e.g., photon polarization states are described when assuming the simplified non-relativistic quantum teleportation equations and special relativity. However, a closed time loop would usually not occur due to phase incompatibilities of the quantum states. Histories with such phase incompatibilities are called inconsistent ones in the present text, and it is assumed that only consistent histories would occur. This is called an exclusion principle for inconsistent histories, and it would yield that probabilities for certain measurement results change. Extended multiple parallel experiments are proposed to use this statistically for transmission of classical information over distances, and regarding time. Experiments might be testable in near future. However, first a deeper analysis, including quantum field theory, remains to be done in future

An inverse spectral problem related to the Geng-Xue two-component peakon equation

CERN Document Server

Lundmark, Hans

2016-01-01

The authors solve a spectral and an inverse spectral problem arising in the computation of peakon solutions to the two-component PDE derived by Geng and Xue as a generalization of the Novikov and Degasperisâe"Procesi equations. Like the spectral problems for those equations, this one is of a âeoediscrete cubic stringâe typeâe"a nonselfadjoint generalization of a classical inhomogeneous stringâe"but presents some interesting novel features: there are two Lax pairs, both of which contribute to the correct complete spectral data, and the solution to the inverse problem can be expressed using quantities related to Cauchy biorthogonal polynomials with two different spectral measures. The latter extends the range of previous applications of Cauchy biorthogonal polynomials to peakons, which featured either two identical, or two closely related, measures. The method used to solve the spectral problem hinges on the hidden presence of oscillatory kernels of Gantmacherâe"Krein type, implying that the spectrum of...

Prediction Equations for Spirometry for Children from Northern India.

Science.gov (United States)

Chhabra, Sunil K; Kumar, Rajeev; Mittal, Vikas

2016-09-08

To develop prediction equations for spirometry for children from northern India using current international guidelines for standardization. Re-analysis of cross-sectional data from a single school. 670 normal children (age 6-17 y; 365 boys) of northern Indian parentage. After screening for normal health, we carried out spirometry with recommended quality assurance according to current guidelines. We developed linear and nonlinear prediction equations using multiple regression analysis. We selected the final models on the basis of the highest coefficient of multiple determination (R2) and statistical validity. Spirometry parameters: FVC, FEV1, PEFR, FEF50, FEF75 and FEF25-75. The equations for the main parameters were as follows: Boys, Ln FVC = -1.687+0.016*height +0.022*age; Ln FEV1 = -1.748+0.015*height+0.031*age. Girls, Ln FVC = -9.989 +(2.018*Ln(height)) + (0.324*Ln(age)); Ln FEV1 = -10.055 +(1.990*Ln(height))+(0.358*Ln(age)). Nonlinear regression yielded substantially greater R2 values compared to linear models except for FEF50 for girls. Height and age were found to be the significant explanatory variables for all parameters on multiple regression with weight making no significant contribution. We developed prediction equations for spirometry for children from northern India. Nonlinear equations were superior to linear equations.

Properties of linear integral equations related to the six-vertex model with disorder parameter II

International Nuclear Information System (INIS)

Boos, Hermann; Göhmann, Frank

2012-01-01

We study certain functions arising in the context of the calculation of correlation functions of the XXZ spin chain and of integrable field theories related to various scaling limits of the underlying six-vertex model. We show that several of these functions that are related to linear integral equations can be obtained by acting with (deformed) difference operators on a master function Φ. The latter is defined in terms of a functional equation and of its asymptotic behavior. Concentrating on the so-called temperature case, we show that these conditions uniquely determine the high-temperature series expansions of the master function. This provides an efficient calculation scheme for the high-temperature expansions of the derived functions as well. (paper)

Music to my ears: Age-related decline in musical and facial emotion recognition.

Science.gov (United States)

Sutcliffe, Ryan; Rendell, Peter G; Henry, Julie D; Bailey, Phoebe E; Ruffman, Ted

2017-12-01

We investigated young-old differences in emotion recognition using music and face stimuli and tested explanatory hypotheses regarding older adults' typically worse emotion recognition. In Experiment 1, young and older adults labeled emotions in an established set of faces, and in classical piano stimuli that we pilot-tested on other young and older adults. Older adults were worse at detecting anger, sadness, fear, and happiness in music. Performance on the music and face emotion tasks was not correlated for either age group. Because musical expressions of fear were not equated for age groups in the pilot study of Experiment 1, we conducted a second experiment in which we created a novel set of music stimuli that included more accessible musical styles, and which we again pilot-tested on young and older adults. In this pilot study, all musical emotions were identified similarly by young and older adults. In Experiment 2, participants also made age estimations in another set of faces to examine whether potential relations between the face and music emotion tasks would be shared with the age estimation task. Older adults did worse in each of the tasks, and had specific difficulty recognizing happy, sad, peaceful, angry, and fearful music clips. Older adults' difficulties in each of the 3 tasks-music emotion, face emotion, and face age-were not correlated with each other. General cognitive decline did not appear to explain our results as increasing age predicted emotion performance even after fluid IQ was controlled for within the older adult group. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Determinants of Health-Related Quality of Life in Taiwanese Middle-Aged Women Stroke Survivors.

Science.gov (United States)

Pai, Hsiang-Chu; Wu, Ming-Hsiu; Chang, Mei-Yueh

Female stroke victims have a higher survival rate and experience a greater loss of quality of life than do male stroke victims. The aim of this study was to evaluate the determinants of health-related quality of life in middle-aged women stroke survivors. This study is a cross-sectional design. This cross-sectional research uses a descriptive, prospective, and correlational study design to investigate the associations between latent variables. Participants included women stroke survivors, aged 45-65 years, who were patients at a medical center in Taiwan. Participants completed an interview and a six-part questionnaire comprising the Short-Form Health Survey (SF-36), National Institutes of Health Stroke Scale, Modified Rankin Scale, Burden Scale, Chinese Health Questionnaire, and five items that pertain to the survivor's cognitive appraisal of coping. Structural equation modeling (SEM), with the use of the partial least squares (PLS) method, was used to examine the proposed conceptual model. A total of 48 dyad samples (48 female stroke survivors, mean age = 55.29; 48 caregivers, mean age = 42.71) participated in the study. Overall, women's physical functioning (PF; stroke severity), cognitive appraisal of coping, and caregiver's psychosocial functioning were the predictors, explaining 43.3% of the variance in women's health-related quality of life. We found that female stroke survivors' level of stroke severity and negative appraisal-impact of stroke are significant predictors of the stroke survivor's quality of life. In addition to assisting women in their PF rehabilitation, rehabilitation nurses also should help to develop survivors' self-care confidence as a means to avoid the recurrence of stroke.

Absolute and Relative Socioeconomic Health Inequalities across Age Groups.

Science.gov (United States)

van Zon, Sander K R; Bültmann, Ute; Mendes de Leon, Carlos F; Reijneveld, Sijmen A

2015-01-01

The magnitude of socioeconomic health inequalities differs across age groups. It is less clear whether socioeconomic health inequalities differ across age groups by other factors that are known to affect the relation between socioeconomic position and health, like the indicator of socioeconomic position, the health outcome, gender, and as to whether socioeconomic health inequalities are measured in absolute or in relative terms. The aim is to investigate whether absolute and relative socioeconomic health inequalities differ across age groups by indicator of socioeconomic position, health outcome and gender. The study sample was derived from the baseline measurement of the LifeLines Cohort Study and consisted of 95,432 participants. Socioeconomic position was measured as educational level and household income. Physical and mental health were measured with the RAND-36. Age concerned eleven 5-years age groups. Absolute inequalities were examined by comparing means. Relative inequalities were examined by comparing Gini-coefficients. Analyses were performed for both health outcomes by both educational level and household income. Analyses were performed for all age groups, and stratified by gender. Absolute and relative socioeconomic health inequalities differed across age groups by indicator of socioeconomic position, health outcome, and gender. Absolute inequalities were most pronounced for mental health by household income. They were larger in younger than older age groups. Relative inequalities were most pronounced for physical health by educational level. Gini-coefficients were largest in young age groups and smallest in older age groups. Absolute and relative socioeconomic health inequalities differed cross-sectionally across age groups by indicator of socioeconomic position, health outcome and gender. Researchers should critically consider the implications of choosing a specific age group, in addition to the indicator of socioeconomic position and health outcome

Nutritional Considerations for Healthy Aging and Reduction in Age-Related Chronic Disease.

Science.gov (United States)

Shlisky, Julie; Bloom, David E; Beaudreault, Amy R; Tucker, Katherine L; Keller, Heather H; Freund-Levi, Yvonne; Fielding, Roger A; Cheng, Feon W; Jensen, Gordon L; Wu, Dayong; Meydani, Simin N

2017-01-01

A projected doubling in the global population of people aged ≥60 y by the year 2050 has major health and economic implications, especially in developing regions. Burdens of unhealthy aging associated with chronic noncommunicable and other age-related diseases may be largely preventable with lifestyle modification, including diet. However, as adults age they become at risk of "nutritional frailty," which can compromise their ability to meet nutritional requirements at a time when specific nutrient needs may be high. This review highlights the role of nutrition science in promoting healthy aging and in improving the prognosis in cases of age-related diseases. It serves to identify key knowledge gaps and implementation challenges to support adequate nutrition for healthy aging, including applicability of metrics used in body-composition and diet adequacy for older adults and mechanisms to reduce nutritional frailty and to promote diet resilience. This review also discusses management recommendations for several leading chronic conditions common in aging populations, including cognitive decline and dementia, sarcopenia, and compromised immunity to infectious disease. The role of health systems in incorporating nutrition care routinely for those aged ≥60 y and living independently and current actions to address nutritional status before hospitalization and the development of disease are discussed. © 2017 American Society for Nutrition.

Kinetic equations for an unstable plasma; Equations cinetiques d'un plasma instable

Energy Technology Data Exchange (ETDEWEB)

Laval, G; Pellat, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

In this work, we establish the plasma kinetic equations starting from the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy of equations. We demonstrate that relations existing between correlation functions may help to justify the truncation of the hierarchy. Then we obtain the kinetic equations of a stable or unstable plasma. They do not reduce to an equation for the one-body distribution function, but generally involve two coupled equations for the one-body distribution function and the spectral density of the fluctuating electric field. We study limiting cases where the Balescu-Lenard equation, the quasi-linear theory, the Pines-Schrieffer equations and the equations of weak turbulence in the random phase approximation are recovered. At last we generalise the H-theorem for the system of equations and we define conditions for irreversible behaviour. (authors) [French] Dans ce travail nous etablissons les equations cinetiques d'un plasma a partir des equations de la recurrence de Bogoliubov, Born, Green, Kirkwood et Yvon. Nous demontrons qu'entre les fonctions de correlation d'un plasma existent des relations qui permettent de justifier la troncature de la recurrence. Nous obtenons alors les equations cinetiques d'un plasma stable ou instable. En general elles ne se reduisent pas a une equation d'evolution pour la densite simple, mais se composent de deux equations couplees portant sur la densite simple et la densite spectrale du champ electrique fluctuant. Nous etudions le cas limites ou l'on retrouve l'equation de Balescu-Lenard, les equations de la theorie quasi-lineaire, les equations de Pines et Schrieffer et les equations de la turbulence faible dans l'approximation des phases aleatoires. Enfin, nous generalisons le theoreme H pour ce systeme d'equations et nous precisons les conditions d'evolution irreversible. (auteurs)

Electrocardiographic findings related to aging

Energy Technology Data Exchange (ETDEWEB)

Ueda, Shoichi; Yano, Katsuhiko

1962-12-12

More than 3000 electrocardiographic tracings for the ABCC-JNIH Adult Health Study Sample were studied to detect any specific abnormalities or nonspecific age changes in relation to possible radiation effects upon the cardiovascular system. The 4 comparison groups were studied with respect to the prevalence of electrocardiographic abnormalities and an electrocardiographic aging index which was defined to evaluate physiological change with age. Statistically significant differences were observed in the following aspects: In males aged 50 to 59, the prevalence of major electrocardiographic abnormalities was highest in the group located nearest the hypocenter. This was not observed in other age groups. In females, the prevalence of QRS high voltage was highest in Group 2 but low in Group 1. This trend was consistent in all age groups. These findings were not fully accounted for by differences in blood pressure, heart size, body weight or serum cholesterol values. In the age trend curve of the electrocardiographic aging index, a difference was observed among comparison groups in both sexes. This difference in electrocardiographic aging index is mainly attributed to T/sub I/ amplitude for males and R/sub II/ amplitude and QRS axis for females. Interpretation of these findings is rather difficult since very little has been known about radiation effects upon the cardiovascular system in humans. Further intensive studies are desired on the basis of the clues suggested in this report. 16 references, 3 figures, 31 tables.

Aging Is Not a Disease: Distinguishing Age-Related Macular Degeneration from Aging

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Ardeljan, Daniel; Chan, Chi-Chao

2013-01-01

Age-related macular degeneration (AMD) is a disease of the outer retina, characterized most significantly by atrophy of photoreceptors and retinal pigment epithelium accompanied with or without choroidal neovascularization. Development of AMD has been recognized as contingent on environmental and genetic risk factors, the strongest being advanced age. In this review, we highlight pathogenic changes that destabilize ocular homeostasis and promote AMD development. With normal aging, photoreceptors are steadily lost, Bruch's membrane thickens, the choroid thins, and hard drusen may form in the periphery. In AMD, many of these changes are exacerbated in addition to the development of disease-specific factors such as soft macular drusen. Para-inflammation, which can be thought of as an intermediate between basal and robust levels of inflammation, develops within the retina in an attempt to maintain ocular homeostasis, reflected by increased expression of the anti-inflammatory cytokine IL-10 coupled with shifts in macrophage plasticity from the pro-inflammatory M1 to the anti-inflammatory M2 polarization. In AMD, imbalances in the M1 and M2 populations together with activation of retinal microglia are observed and potentially contribute to tissue degeneration. Nonetheless, the retina persists in a state of chronic inflammation and increased expression of certain cytokines and inflammasomes is observed. Since not everyone develops AMD, the vital question to ask is how the body establishes a balance between normal age-related changes and the pathological phenotypes in AMD. PMID:23933169

Age--velocity-dispersion relation in the solar neighborhood

International Nuclear Information System (INIS)

Carlberg, R.G.; Dawson, P.C.; Hsu, T.; VandenBerg, D.A.

1985-01-01

The age--velocity-dispersion relation for stars in the solar neighborhood is examined as an indicator of the dominant acceleration mechanism of the stars and the formation history of the local disk. Twarog's sample of F stars, for which ages and photometric distances can be determined, is combined with astrometric data to obtain tangential velocities of a set of stars with a large age range. The resulting age--velocity-dispersion relation rises fairly steeply for stars less than 6 Gyr old, thereafter becoming nearly constant with age. These data are consistent with a simple model in which no local disk is initially present, following which stars are born at a constant rate in time and heated by transient spiral waves. The corresponding age-metallicity relation complements this dynamical measure of the formation history of the disk. The use of new stellar models and a revised metallicity calibration leads to quantitative differences from previous work

Accident sequence precursor events with age-related contributors

Energy Technology Data Exchange (ETDEWEB)

Murphy, G.A.; Kohn, W.E.

1995-12-31

The Accident Sequence Precursor (ASP) Program at ORNL analyzed about 14.000 Licensee Event Reports (LERs) filed by US nuclear power plants 1987--1993. There were 193 events identified as precursors to potential severe core accident sequences. These are reported in G/CR-4674. Volumes 7 through 20. Under the NRC Nuclear Plant Aging Research program, the authors evaluated these events to determine the extent to which component aging played a role. Events were selected that involved age-related equipment degradation that initiated an event or contributed to an event sequence. For the 7-year period, ORNL identified 36 events that involved aging degradation as a contributor to an ASP event. Except for 1992, the percentage of age-related events within the total number of ASP events over the 7-year period ({approximately}19%) appears fairly consistent up to 1991. No correlation between plant ape and number of precursor events was found. A summary list of the age-related events is presented in the report.

The effect of education on age-related changes in three cognitive domains: a cross-sectional study in primary care.

Science.gov (United States)

Martins, Isabel Pavão; Maruta, Carolina; Silva, Cláudia; Rodrigues, Pedro; Chester, Catarina; Ginó, Sandra; Freitas, Vanda; Freitas, Sara; Oliveira, António Gouveia

2012-01-01

The present study aims to investigate the protective effect of formal education on age-related changes in different cognitive domains with the hypothesis that it may attenuate the rate of decline. Individuals aged 50 years or older attending primary care physicians without known brain disease (431 participants, mostly [60.3%] female with 66.3 [±9.1] years of age and 7.7 [±4.1] years of education, on average), were evaluated with a neuropsychological battery including 28 cognitive measures. Cognitive domains identified by factor analysis were subject to repeated multiple regression analyses to determine the variance explained by age and education controlling for gender, depressive symptoms, and vascular risk factors. The slope of the regression equation was compared between two educational groups with an average of 4 years and 11 years of education, respectively. Factors identified corresponded to processing ability (Factor 1), memory (Factor 2), and acquired knowledge (Factor 3). Although education improved performance in Factors 1 and 3, it did not change the slope of age-related decline in any factor. This study suggests that in culturally heterogeneous groups, small increments in education enhance cognition but do not modify the rate of decline of executive functioning with age. These results contradict some clinical findings and need to be confirmed in longitudinal studies.

Age-related macular degeneration.

Science.gov (United States)

Cheung, Lily K; Eaton, Angie

2013-08-01

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, and the prevalence of the disease increases exponentially with every decade after age 50 years. It is a multifactorial disease involving a complex interplay of genetic, environmental, metabolic, and functional factors. Besides smoking, hypertension, obesity, and certain dietary habits, a growing body of evidence indicates that inflammation and the immune system may play a key role in the development of the disease. AMD may progress from the early form to the intermediate form and then to the advanced form, where two subtypes exist: the nonneovascular (dry) type and the neovascular (wet) type. The results from the Age-Related Eye Disease Study have shown that for the nonneovascular type of AMD, supplementation with high-dose antioxidants (vitamin C, vitamin E, and β-carotene) and zinc is recommended for those with the intermediate form of AMD in one or both eyes or with advanced AMD or vision loss due to AMD in one eye. As for the neovascular type of the advanced AMD, the current standard of therapy is intravitreal injections of vascular endothelial growth factor inhibitors. In addition, lifestyle and dietary modifications including improved physical activity, reduced daily sodium intake, and reduced intake of solid fats, added sugars, cholesterol, and refined grain foods are recommended. To date, no study has demonstrated that AMD can be cured or effectively prevented. Clearly, more research is needed to fully understand the pathophysiology as well as to develop prevention and treatment strategies for this devastating disease. © 2013 Pharmacotherapy Publications, Inc.

Examining age-related shared variance between face cognition, vision, and self-reported physical health: a test of the common cause hypothesis for social cognition

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Olderbak, Sally; Hildebrandt, Andrea; Wilhelm, Oliver

2015-01-01

The shared decline in cognitive abilities, sensory functions (e.g., vision and hearing), and physical health with increasing age is well documented with some research attributing this shared age-related decline to a single common cause (e.g., aging brain). We evaluate the extent to which the common cause hypothesis predicts associations between vision and physical health with social cognition abilities specifically face perception and face memory. Based on a sample of 443 adults (17–88 years old), we test a series of structural equation models, including Multiple Indicator Multiple Cause (MIMIC) models, and estimate the extent to which vision and self-reported physical health are related to face perception and face memory through a common factor, before and after controlling for their fluid cognitive component and the linear effects of age. Results suggest significant shared variance amongst these constructs, with a common factor explaining some, but not all, of the shared age-related variance. Also, we found that the relations of face perception, but not face memory, with vision and physical health could be completely explained by fluid cognition. Overall, results suggest that a single common cause explains most, but not all age-related shared variance with domain specific aging mechanisms evident. PMID:26321998

Examining Age-Related Shared Variance Between Face Cognition, Vision, and Self-Reported Physical Health: A Test of the Common Cause Hypothesis for Social Cognition

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Sally eOlderbak

2015-08-01

Full Text Available The shared decline in cognitive abilities, sensory functions (e.g., vision and hearing, and physical health with increasing age is well documented with some research attributing this shared age-related decline to a single common cause (e.g., aging brain. We evaluate the extent to which the common cause hypothesis predicts associations between vision and physical health with social cognition abilities, specifically face perception and face memory. Based on a sample of 443 adults (17 to 88 years old, we test a series of structural equation models, including Multiple Indicator Multiple Cause (MIMIC models, and estimate the extent to which vision and self-reported physical health are related to face perception and face memory through a common factor, before and after controlling for their fluid cognitive component and the linear effects of age. Results suggest significant shared variance amongst these constructs, with a common factor explaining some, but not all, of the shared age-related variance. Also, we found that the relations of face perception, but not face memory, with vision and physical health could be completely explained by fluid cognition. Overall, results suggest that a single common cause explains most, but not all age-related shared variance with domain specific aging mechanisms evident.

Sleep-Related Erections Throughout the Ages

NARCIS (Netherlands)

van Driel, Mels F.

Introduction. The occurrence of sleep-related erections (SREs) has been known since antiquity. Aim. To highlight historical, theological, and sexual medicine-related aspects of SREs throughout the ages. Methods. Review of old medical books on male sexual functioning and review of scientific medical

A simple algebraic cancer equation: calculating how cancers may arise with normal mutation rates

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Shibata Darryl

2010-01-01

Full Text Available Abstract Background The purpose of this article is to present a relatively easy to understand cancer model where transformation occurs when the first cell, among many at risk within a colon, accumulates a set of driver mutations. The analysis of this model yields a simple algebraic equation, which takes as inputs the number of stem cells, mutation and division rates, and the number of driver mutations, and makes predictions about cancer epidemiology. Methods The equation [p = 1 - (1 - (1 - (1 - udkNm ] calculates the probability of cancer (p and contains five parameters: the number of divisions (d, the number of stem cells (N × m, the number of critical rate-limiting pathway driver mutations (k, and the mutation rate (u. In this model progression to cancer "starts" at conception and mutations accumulate with cell division. Transformation occurs when a critical number of rate-limiting pathway mutations first accumulates within a single stem cell. Results When applied to several colorectal cancer data sets, parameter values consistent with crypt stem cell biology and normal mutation rates were able to match the increase in cancer with aging, and the mutation frequencies found in cancer genomes. The equation can help explain how cancer risks may vary with age, height, germline mutations, and aspirin use. APC mutations may shorten pathways to cancer by effectively increasing the numbers of stem cells at risk. Conclusions The equation illustrates that age-related increases in cancer frequencies may result from relatively normal division and mutation rates. Although this equation does not encompass all of the known complexity of cancer, it may be useful, especially in a teaching setting, to help illustrate relationships between small and large cancer features.

Intrinsic brain connectivity related to age in young and middle aged adults.

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Michelle Hampson

Full Text Available Age-related variations in resting state connectivity of the human brain were examined from young adulthood through middle age. A voxel-based network measure, degree, was used to assess age-related differences in tissue connectivity throughout the brain. Increases in connectivity with age were found in paralimbic cortical and subcortical regions. Decreases in connectivity were found in cortical regions, including visual areas and the default mode network. These findings differ from those of recent developmental studies examining earlier growth trajectories, and are consistent with known changes in cognitive function and emotional processing during mature aging. The results support and extend previous findings that relied on a priori definitions of regions of interest for their analyses. This approach of applying a voxel-based measure to examine the functional connectivity of individual tissue elements over time, without the need for a priori region of interest definitions, provides an important new tool in brain science.

Ordinary differential equations

CERN Document Server

Greenberg, Michael D

2014-01-01

Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps

Low Calorie Diet Affects Aging-Related Factors

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... Current Issue Past Issues Research News From NIH Low Calorie Diet Affects Aging-Related Factors Past Issues / ... to learn more about the effects of sustained low-calorie diets in humans on factors affecting aging. ...

The Prevalence of Age-Related Eye Diseases and Visual Impairment in Aging: Current Estimates

Science.gov (United States)

Klein, Ronald; Klein, Barbara E. K.

2013-01-01

Purpose. To examine prevalence of five age-related eye conditions (age-related cataract, AMD, open-angle glaucoma, diabetic retinopathy [DR], and visual impairment) in the United States. Methods. Review of published scientific articles and unpublished research findings. Results. Cataract, AMD, open-angle glaucoma, DR, and visual impairment prevalences are high in four different studies of these conditions, especially in people over 75 years of age. There are disparities among racial/ethnic groups with higher age-specific prevalence of DR, open-angle glaucoma, and visual impairment in Hispanics and blacks compared with whites, higher prevalence of age-related cataract in whites compared with blacks, and higher prevalence of late AMD in whites compared with Hispanics and blacks. The estimates are based on old data and do not reflect recent changes in the distribution of age and race/ethnicity in the United States population. There are no epidemiologic estimates of prevalence for many visually-impairing conditions. Conclusions. Ongoing prevalence surveys designed to provide reliable estimates of visual impairment, AMD, age-related cataract, open-angle glaucoma, and DR are needed. It is important to collect objective data on these and other conditions that affect vision and quality of life in order to plan for health care needs and identify areas for further research. PMID:24335069

Factors relating to age of onset in autism.

Science.gov (United States)

Short, A B; Schopler, E

1988-06-01

We examined the distribution of ages of onset of autism and related communication handicaps and assessed factors related to age of onset. Subjects were approximately 1,800 children seen at Division TEACCH (Treatment and Education of Autistic and related Communication handicapped CHildren) since 1970. Exact numbers of subjects varied with different analyses due to missing data. Data were gathered through direct assessment, interview, and questionnaire. Seventy-six percent of autistic children were identified by parents by 24 months of age, and 94% by 36 months. Families reporting early onset tended to seek help sooner and to be seen by TEACCH sooner. Early onset was most clearly related to severity as measured by IQ and ratings on the Childhood Autism Rating Scale (Schopler, Reichler, & Renner, 1986). The findings support the treatment of age of onset of autism by DSM-III-R (American Psychiatric Association, 1987).

Relative Age Effects in Dutch Adolescents: Concurrent and Prospective Analyses.

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Bertus F Jeronimus

Full Text Available The literature on relative age position effects is rather inconsistent. In this study we examined intra-classroom age position (or relative age effects on Dutch adolescents' school progress and performance (as rated by teachers, physical development, temperamental development (fear and frustration, and depressive symptoms, all adjusted for age at the time of measurement. Data were derived from three waves of Tracking Adolescents' Individuals Lives Survey (TRAILS of 2230 Dutch adolescents (baseline mean age 11.1, SD = 0.6, 51% girls. Albeit relative age predicted school progress (grade retention ORs = 0.83 for each month, skipped grade OR = 1.47, both p<.001, our key observation is the absence of substantial developmental differences as a result of relative age position in Dutch adolescents with a normative school trajectory, in contrast to most literature. For adolescents who had repeated a grade inverse relative age effects were observed, in terms of physical development and school performance, as well as on depressive symptoms, favoring the relatively young. Cross-cultural differences in relative age effect may be partly explained by the decision threshold for grade retention.

Age-related synaptic loss of the medial olivocochlear efferent innervation

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Schrader Angela

2010-11-01

Full Text Available Abstract Age-related functional decline of the nervous system is consistently observed, though cellular and molecular events responsible for this decline remain largely unknown. One of the most prevalent age-related functional declines is age-related hearing loss (presbycusis, a major cause of which is the loss of outer hair cells (OHCs and spiral ganglion neurons. Previous studies have also identified an age-related functional decline in the medial olivocochlear (MOC efferent system prior to age-related loss of OHCs. The present study evaluated the hypothesis that this functional decline of the MOC efferent system is due to age-related synaptic loss of the efferent innervation of the OHCs. To this end, we used a recently-identified transgenic mouse line in which the expression of yellow fluorescent protein (YFP, under the control of neuron-specific elements from the thy1 gene, permits the visualization of the synaptic connections between MOC efferent fibers and OHCs. In this model, there was a dramatic synaptic loss between the MOC efferent fibers and the OHCs in older mice. However, age-related loss of efferent synapses was independent of OHC status. These data demonstrate for the first time that age-related loss of efferent synapses may contribute to the functional decline of the MOC efferent system and that this synaptic loss is not necessary for age-related loss of OHCs.

Working memory in middle-aged males: Age-related brain activation changes and cognitive fatigue effects

NARCIS (Netherlands)

Klaassen, Elissa; Evers, Elisabeth; De Groot, Renate; Backes, Walter; Veltman, Dick; Jolles, Jelle

2017-01-01

We examined the effects of aging and cognitive fatigue on working memory (WM) related brain activation using functional magnetic resonance imaging. Age-related differences were investigated in 13 young and 16 middle-aged male school teachers. Cognitive fatigue was induced by sustained performance on

Linking age, survival, and transit time distributions

Science.gov (United States)

Calabrese, Salvatore; Porporato, Amilcare

2015-10-01

Although the concepts of age, survival, and transit time have been widely used in many fields, including population dynamics, chemical engineering, and hydrology, a comprehensive mathematical framework is still missing. Here we discuss several relationships among these quantities by starting from the evolution equation for the joint distribution of age and survival, from which the equations for age and survival time readily follow. It also becomes apparent how the statistical dependence between age and survival is directly related to either the age dependence of the loss function or the survival-time dependence of the input function. The solution of the joint distribution equation also allows us to obtain the relationships between the age at exit (or death) and the survival time at input (or birth), as well as to stress the symmetries of the various distributions under time reversal. The transit time is then obtained as a sum of the age and survival time, and its properties are discussed along with the general relationships between their mean values. The special case of steady state case is analyzed in detail. Some examples, inspired by hydrologic applications, are presented to illustrate the theory with the specific results. This article was corrected on 11 Nov 2015. See the end of the full text for details.

Age-related differences in working memory updating components.

Science.gov (United States)

Linares, Rocío; Bajo, M Teresa; Pelegrina, Santiago

2016-07-01

The aim of this study was to investigate possible age-related changes throughout childhood and adolescence in different component processes of working memory updating (WMU): retrieval, transformation, and substitution. A set of numerical WMU tasks was administered to four age groups (8-, 11-, 14-, and 21-year-olds). To isolate the effect of each of the WMU components, participants performed different versions of a task that included different combinations of the WMU components. The results showed an expected overall decrease in response times and an increase in accuracy performance with age. Most important, specific age-related changes in the retrieval component were found, demonstrating that the effect of retrieval on accuracy was larger in children than in adolescents or young adults. These findings indicate that the availability of representations from outside the focus of attention may change with age. Thus, the retrieval component of updating could contribute to the age-related changes observed in the performance of many updating tasks. Copyright © 2016 Elsevier Inc. All rights reserved.

Does eating particular diets alter risk of age-related macular degeneration in users of the Age-Related Eye Disease Study supplements?

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Background: Recent information suggests that the Age-Related Eye Disease Study (AREDS) supplement, enhanced intake of omega-3 fatty acids, and diminishing dietary glycemic index (dGI) are protective against advanced age-related macular degeneration (AMD). Methods: Dietary information was collected a...

A new type of massive spin-one boson: And its relation with Maxwell equations

International Nuclear Information System (INIS)

Ahluwalia, D.V.

1995-01-01

First, the author showed that in the (1, 0) circle-plus (0, 1) representation space there exist not one but two theories for charged particles. In the Weinberg construct, the boson and its antiboson carry same relative intrinsic parity, whereas in the author's construct the relative intrinsic parities of the boson and its antiboson are opposite. These results originate from the commutativity of the operations of Charge conjugation and Parity in Weinberg's theory, and from the anti-commutativity of the operations of Charge conjugation and Parity in the author's theory. The author thus claims that he has constructed a first non-trivial quantum theory of fields for the Wigner-type particles. Second, the massless limit of both theories seems formally identical and suggests a fundamental modification of Maxwell equations. At its simplest level, the modification to Maxwell equations enters via additional boundary condition(s)

A note on Verhulst's logistic equation and related logistic maps

International Nuclear Information System (INIS)

Gutierrez, M Ranferi; Reyes, M A; Rosu, H C

2010-01-01

We consider the Verhulst logistic equation and a couple of forms of the corresponding logistic maps. For the case of the logistic equation we show that using the general Riccati solution only changes the initial conditions of the equation. Next, we consider two forms of corresponding logistic maps reporting the following results. For the map x n+1 = rx n (1 - x n ) we propose a new way to write the solution for r = -2 which allows better precision of the iterative terms, while for the map x n+1 - x n = rx n (1 - x n+1 ) we show that it behaves identically to the logistic equation from the standpoint of the general Riccati solution, which is also provided herein for any value of the parameter r.

The Relative Age Effect and Its Influence on Academic Performance.

Science.gov (United States)

Navarro, Juan-José; García-Rubio, Javier; Olivares, Pedro R

2015-01-01

The policy of school organisation for grouping students in the same academic year is based on date of birth. The differences in the experiences and maturation of older students involve a relatively better performance in academic settings, which is known as the relative age effect (RAE). This effect is more important the younger the student is. The goal of this study is to identify the connections of influence that RAE, socioeconomic status (SES), and type of institution have on academic performance in a school population of eighth graders. The study is based on a population-based, representative sample of 15,234 8th graders (50.4% female; average age = 13.61 years) in the 2011 National System of Quality Assessment in Education Survey (SIMCE) from Chile. The SIMCE for global academic performance consists of 4 tests: reading, mathematics, social studies, and science. All tests consist of multiple-choice and closed questions. In addition, in order to have the information of general academic performance, an extra variable expressing the average score of each student was created. Also, the SIMCE includes additional variables for the evaluation process such as SES or type of school. Students were assigned to one of five age groups in terms of date of birth (G1, G2, G3, G4, and G5), in which students belonging to G1 are the oldest and students belonging to G5 are the youngest. The results achieved in the structural equation modelling indicate a good global fit. Individual relationships show significant effects of the three variables observed on academic performance, although SES received the highest values. The influence of RAE took place both in the full sample and sub-samples composed according to the SES and academic performance, showing higher values for students with lower scores. Although the influence of RAE decreases when SES is controlled, its effect is still significant and contributes to additionally explain the performance. The RAE remains, even with residual

The Relative Age Effect and Its Influence on Academic Performance.

Directory of Open Access Journals (Sweden)

Juan-José Navarro

Full Text Available The policy of school organisation for grouping students in the same academic year is based on date of birth. The differences in the experiences and maturation of older students involve a relatively better performance in academic settings, which is known as the relative age effect (RAE. This effect is more important the younger the student is. The goal of this study is to identify the connections of influence that RAE, socioeconomic status (SES, and type of institution have on academic performance in a school population of eighth graders.The study is based on a population-based, representative sample of 15,234 8th graders (50.4% female; average age = 13.61 years in the 2011 National System of Quality Assessment in Education Survey (SIMCE from Chile. The SIMCE for global academic performance consists of 4 tests: reading, mathematics, social studies, and science. All tests consist of multiple-choice and closed questions. In addition, in order to have the information of general academic performance, an extra variable expressing the average score of each student was created. Also, the SIMCE includes additional variables for the evaluation process such as SES or type of school. Students were assigned to one of five age groups in terms of date of birth (G1, G2, G3, G4, and G5, in which students belonging to G1 are the oldest and students belonging to G5 are the youngest.The results achieved in the structural equation modelling indicate a good global fit. Individual relationships show significant effects of the three variables observed on academic performance, although SES received the highest values. The influence of RAE took place both in the full sample and sub-samples composed according to the SES and academic performance, showing higher values for students with lower scores. Although the influence of RAE decreases when SES is controlled, its effect is still significant and contributes to additionally explain the performance.The RAE remains, even

Age-Related Maculopathy: a biochemical and immunohistochemical study

NARCIS (Netherlands)

M. Kliffen (Mike)

1996-01-01

textabstractAge-related maculopathy (ARM) is an age-related degenerative disorder of the central part of the retina, the macula lutea (yellow spot). Essentially, ARM is a clinical diagnosis based on funduscopical changes. It is customary nowadays to call the late stages of ARM, geographic atrophy

Age-related hearing loss or presbycusis.

Science.gov (United States)

Huang, Qi; Tang, Jianguo

2010-08-01

Aging is a natural consequence of a society developing process. Although many adults retain good hearing as they aging, hearing loss related with age-presbycusis which can vary in severity from mild to substantial is common among elderly persons. There are a number of pathophysiological processes underlying age-related changes in the auditory system as well as in the central nervous systems. Many studies have been dedicated to the illustration of risk factors accumulating presbycusis such as heritability, environment factors, medical conditions, free radical (reactive oxygen species, ROS) and damage of mitochondrial DNA. Left untreated, presbycusis can not only lead sufferers to reduced quality of life, isolation, dependence and frustration, but also affect the healthy people around. These can be partly corrected using hearing aids, but it is not enough, more and more strategies of treatment based on the findings associating with presbycusis should be added rather than using single hearing aids. We review here the pathophysiology; heritability, susceptibility genes and other risk factors including environmental, medical, especially free radical (ROS) and damage of mitochondrial DNA; and some strategies of treatment, as well as promising rehabilitations associating with presbycusis.

Age-Related Neurochemical Changes in the Vestibular Nuclei

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Paul eSmith

2016-03-01

Full Text Available There is evidence that the normal aging process is associated with impaired vestibulo-ocular (VOR and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa’s ganglion and the vestibular nucleus complex (VNC, it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarises and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

Age-Related Neurochemical Changes in the Vestibular Nuclei.

Science.gov (United States)

Smith, Paul F

2016-01-01

There is evidence that the normal aging process is associated with impaired vestibulo-ocular reflexes (VOR) and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa's ganglion and the vestibular nucleus complex (VNC), it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarizes and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

Genome and Epigenome Editing in Mechanistic Studies of Human Aging and Aging-Related Disease.

Science.gov (United States)

Lau, Cia-Hin; Suh, Yousin

2017-01-01

The recent advent of genome and epigenome editing technologies has provided a new paradigm in which the landscape of the human genome and epigenome can be precisely manipulated in their native context. Genome and epigenome editing technologies can be applied to many aspects of aging research and offer the potential to develop novel therapeutics against age-related diseases. Here, we discuss the latest technological advances in the CRISPR-based genome and epigenome editing toolbox, and provide insight into how these synthetic biology tools could facilitate aging research by establishing in vitro cell and in vivo animal models to dissect genetic and epigenetic mechanisms underlying aging and age-related diseases. We discuss recent developments in the field with the aims to precisely modulate gene expression and dynamic epigenetic landscapes in a spatial and temporal manner in cellular and animal models, by complementing the CRISPR-based editing capability with conditional genetic manipulation tools including chemically inducible expression systems, optogenetics, logic gate genetic circuits, tissue-specific promoters, and the serotype-specific adeno-associated virus. We also discuss how the combined use of genome and epigenome editing tools permits investigators to uncover novel molecular pathways involved in the pathophysiology and etiology conferred by risk variants associated with aging and aging-related disease. A better understanding of the genetic and epigenetic regulatory mechanisms underlying human aging and age-related disease will significantly contribute to the developments of new therapeutic interventions for extending health span and life span, ultimately improving the quality of life in the elderly populations. © 2016 S. Karger AG, Basel.

From ordinary to partial differential equations

CERN Document Server

Esposito, Giampiero

2017-01-01

This book is addressed to mathematics and physics students who want to develop an interdisciplinary view of mathematics, from the age of Riemann, Poincaré and Darboux to basic tools of modern mathematics. It enables them to acquire the sensibility necessary for the formulation and solution of difficult problems, with an emphasis on concepts, rigour and creativity. It consists of eight self-contained parts: ordinary differential equations; linear elliptic equations; calculus of variations; linear and non-linear hyperbolic equations; parabolic equations; Fuchsian functions and non-linear equations; the functional equations of number theory; pseudo-differential operators and pseudo-differential equations. The author leads readers through the original papers and introduces new concepts, with a selection of topics and examples that are of high pedagogical value.

Beyond chronological age. Examining perceived future time and subjective health as age-related mediators in relation to work-related motivations and well-being

NARCIS (Netherlands)

Kooij, D.T.A.M.; Lange, A.H. de; Jansen, P.G.W.; Dikkers, J.S.E.

2013-01-01

Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

Beyond chronological age : Examining perceived future time and subjective health as age-related mediators in relation to work-related motivations and well-being

NARCIS (Netherlands)

Kooij, T.A.M.; de Lange, A.H.; Jansen, P.G.W.; Dikkers, J.S.E.

2013-01-01

Since workforces across the world are aging, researchers and organizations need more insight into how and why occupational well-being, together with work-related attitudes and motivations, change with age. Lifespan theories point to subjective health and future time perspective (i.e. an individual's

The Rationale for Delaying Aging and the Prevention of Age-Related Diseases

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Nir Barzilai

2012-10-01

Full Text Available [Excerpt] We offer a different approach to delaying or preventing age-related diseases. To understand the necessity for a new approach we have plotted the mortality rates in Israelis in relation to specific age groups and diseases. With the common phenomenon of aging of Western populations it is of utmost importance to follow time-dependent and age-dependent mortality patterns to predict future needs of Western health systems. Age-specific, gender-specific, and cause-of-death-specific mortality rates were extracted from the statistical abstract of Israel1 and include data for the period of 1975–2010; these are presented in Figure 1, separately for men (A and women (B. Detailed age-specific causes of death data were available for the year 2009. Data presented were restricted to 5-year age groups starting at age 50, and for cause-specific mortality to the following age groups: 45–54, 55–64, 65–74, 75–84, and 85+. Causes of mortality were separated into malignant diseases, acute myocardial infarction, other ischemic heart diseases, other forms of heart diseases, cerebrovascular disease, diabetes mellitus, respiratory diseases, diseases of kidney, infectious diseases, all external causes, signs/symptoms and ill-defined conditions, and all other diseases. Figure 1 is similar to the one posted on the National Institute of Aging website and similar to data across the industrial world. The striking feature of this graph is that aging is a major log scale risk for most diseases, including the major killers: heart disease, cancer, diabetes, and Alzheimer’s. For example, while aging is a 100-fold risk for cardiovascular disease (CVD according to Figure 1, hypercholesterolemia is known to carry only a three-fold risk for CVD. For each of the mentioned diseases, aging is a log risk greater than the most important known risk factor for that disease.

Age at menarche and pregnancy-related pelvic pain

DEFF Research Database (Denmark)

Kirkeby, Mette J; Biering, Karin; Olsen, Jørn

2013-01-01

AIM: Menarcheal age is a predictor of several complications related to pregnancy and diseases later in life. We aimed to study if menarcheal age is a risk factor for pregnancy-related pelvic pain. MATERIAL AND METHODS: A nested case-control study was conducted within the Danish National Birth...

Applied partial differential equations

CERN Document Server

Logan, J David

2004-01-01

This primer on elementary partial differential equations presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs. What makes this book unique is that it is a brief treatment, yet it covers all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. Mathematical ideas are motivated from physical problems, and the exposition is presented in a concise style accessible to science and engineering students; emphasis is on motivation, concepts, methods, and interpretation, rather than formal theory. This second edition contains new and additional exercises, and it includes a new chapter on the applications of PDEs to biology: age structured models, pattern formation; epidemic wave fronts, and advection-diffusion processes. The student who reads through this book and solves many of t...

The general class of the vacuum spherically symmetric equations of the general relativity theory

International Nuclear Information System (INIS)

Karbanovski, V. V.; Sorokin, O. M.; Nesterova, M. I.; Bolotnyaya, V. A.; Markov, V. N.; Kairov, T. V.; Lyash, A. A.; Tarasyuk, O. R.

2012-01-01

The system of the spherical-symmetric vacuum equations of the General Relativity Theory is considered. The general solution to a problem representing two classes of line elements with arbitrary functions g 00 and g 22 is obtained. The properties of the found solutions are analyzed.

Reciprocity relations and the mode conversion-absorption equation with an inhomogeneous source term

International Nuclear Information System (INIS)

Cho, S.; Swanson, D.G.

1990-01-01

The fourth-order mode conversion equation is solved completely via the Green's function to include an inhomogeneous source term. This Green's function itself contains all the plasma responsive effects such as mode conversion and absorption, and can be used to describe the spontaneous emission. In the course of the analysis, the reciprocity relations between coupling parameters are proved

A differential equation for the transition probability B(E2)↑ and the resulting recursion relations connecting even–even nuclei

Energy Technology Data Exchange (ETDEWEB)

Pattnaik, S. [Taratarini College, Purusottampur, Ganjam, Odisha (India); Nayak, R. C. [Department of Physics, Berhampur University, Brahmapur-760007 (India)

2014-04-15

We obtain here a new relation for the reduced electric quadrupole transition probability B(E2)↑ of a given nucleus in terms of its derivatives with respect to neutron and proton numbers based on a similar local energy relation in the Infinite Nuclear Matter (INM) model of atomic nuclei, which is essentially built on the foundation of the Hugenholtz–Van Hove (HVH) theorem of many-body theory. Obviously, such a relation in the form of a differential equation is expected to be more powerful than the usual algebraic difference equations. Although the relation for B(E2)↑ has been perceived simply on the basis of a corresponding differential equation for the local energy in the INM model, its theoretical foundation otherwise has been clearly demonstrated. We further exploit the differential equation in using the very definitions of the derivatives to obtain two different recursion relations for B(E2)↑, connecting in each case three neighboring even–even nuclei from lower to higher mass numbers and vice versa. We demonstrate their numerical validity using available data throughout the nuclear chart and also explore their possible utility in predicting B(E2)↑ values. (author)

A differential equation for the transition probability B(E2)↑ and the resulting recursion relations connecting even–even nuclei

International Nuclear Information System (INIS)

Pattnaik, S.; Nayak, R.C.

2014-01-01

We obtain here a new relation for the reduced electric quadrupole transition probability B(E2)↑ of a given nucleus in terms of its derivatives with respect to neutron and proton numbers based on a similar local energy relation in the Infinite Nuclear Matter (INM) model of atomic nuclei, which is essentially built on the foundation of the Hugenholtz–Van Hove (HVH) theorem of many-body theory. Obviously, such a relation in the form of a differential equation is expected to be more powerful than the usual algebraic difference equations. Although the relation for B(E2)↑ has been perceived simply on the basis of a corresponding differential equation for the local energy in the INM model, its theoretical foundation otherwise has been clearly demonstrated. We further exploit the differential equation in using the very definitions of the derivatives to obtain two different recursion relations for B(E2)↑, connecting in each case three neighboring even–even nuclei from lower to higher mass numbers and vice versa. We demonstrate their numerical validity using available data throughout the nuclear chart and also explore their possible utility in predicting B(E2)↑ values. (author)

Refractive error magnitude and variability: Relation to age.

Science.gov (United States)

Irving, Elizabeth L; Machan, Carolyn M; Lam, Sharon; Hrynchak, Patricia K; Lillakas, Linda

2018-03-19

To investigate mean ocular refraction (MOR) and astigmatism, over the human age range and compare severity of refractive error to earlier studies from clinical populations having large age ranges. For this descriptive study patient age, refractive error and history of surgery affecting refraction were abstracted from the Waterloo Eye Study database (WatES). Average MOR, standard deviation of MOR and astigmatism were assessed in relation to age. Refractive distributions for developmental age groups were determined. MOR standard deviation relative to average MOR was evaluated. Data from earlier clinically based studies with similar age ranges were compared to WatES. Right eye refractive errors were available for 5933 patients with no history of surgery affecting refraction. Average MOR varied with age. Children <1 yr of age were the most hyperopic (+1.79D) and the highest magnitude of myopia was found at 27yrs (-2.86D). MOR distributions were leptokurtic, and negatively skewed. The mode varied with age group. MOR variability increased with increasing myopia. Average astigmatism increased gradually to age 60 after which it increased at a faster rate. By 85+ years it was 1.25D. J 0 power vector became increasingly negative with age. J 45 power vector values remained close to zero but variability increased at approximately 70 years. In relation to comparable earlier studies, WatES data were most myopic. Mean ocular refraction and refractive error distribution vary with age. The highest magnitude of myopia is found in young adults. Similar to prevalence, the severity of myopia also appears to have increased since 1931. Copyright © 2018 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

Emotion identification and aging: Behavioral and neural age-related changes.

Science.gov (United States)

Gonçalves, Ana R; Fernandes, Carina; Pasion, Rita; Ferreira-Santos, Fernando; Barbosa, Fernando; Marques-Teixeira, João

2018-05-01

Aging is known to alter the processing of facial expressions of emotion (FEE), however the impact of this alteration is less clear. Additionally, there is little information about the temporal dynamics of the neural processing of facial affect. We examined behavioral and neural age-related changes in the identification of FEE using event-related potentials. Furthermore, we analyze the relationship between behavioral/neural responses and neuropsychological functioning. To this purpose, 30 younger adults, 29 middle-aged adults and 26 older adults identified FEE. The behavioral results showed a similar performance between groups. The neural results showed no significant differences between groups for the P100 component and an increased N170 amplitude in the older group. Furthermore, a pattern of asymmetric activation was evident in the N170 component. Results also suggest deficits in facial feature decoding abilities, reflected by a reduced N250 amplitude in older adults. Neuropsychological functioning predicts P100 modulation, but does not seem to influence emotion identification ability. The findings suggest the existence of a compensatory function that would explain the age-equivalent performance in emotion identification. The study may help future research addressing behavioral and neural processes involved on processing of FEE in neurodegenerative conditions. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

A cross-lagged structural equation model of relational aggression, physical aggression, and peer status in a Chinese culture.

Science.gov (United States)

Tseng, Wan-Ling; Banny, Adrienne M; Kawabata, Yoshito; Crick, Nicki R; Gau, Susan Shur-Fen

2013-01-01

This short-term longitudinal study examined the associations among relational aggression, physical aggression, and peer status (i.e., acceptance, rejection, and perceived popularity) across three time points, six months apart, in a Taiwanese sample. Participants were 198 fifth grade students (94 girls and 104 boys; Mean age = 10.35 years) from Taipei, Taiwan. Study variables were assessed using peer nomination procedure. Results from the cross-lagged structural equation models demonstrated that there were longitudinal associations between relational aggression and each of the peer status constructs while only one longitudinal association was found for physical aggression such that physical aggression positively predicted subsequent peer rejection. The longitudinal associations did not vary with gender. Results also showed high stabilities of relational aggression, physical aggression, and the three peer status constructs over 1 year as well as high concurrent association between relational and physical aggression. In addition, relational aggression and physical aggression were concurrently related to less acceptance, more rejection, and less perceived popularity, especially at the outset of the study. Findings of this study demonstrated both similarities and differences in relation to previous literature in primarily Western cultures. This study also highlights the bidirectional and complex nature of the association between aggression and peer status, which appears to depend on the form of aggression and on the particular indicator of peer status under study. Copyright © 2013 Wiley Periodicals, Inc.

[Presbycusis - Age Related Hearing Loss].

Science.gov (United States)

Fischer, N; Weber, B; Riechelmann, H

2016-07-01

Presbycusis or age related hearing loss can be defined as a progressive, bilateral and symmetrical sensorineural hearing loss due to age related degeneration of inner ear structures. It can be considered a multifactorial complex disorder with environmental and genetic factors. The molecular, electrophysiological and histological damage at different levels of the inner ear cause a progressive hearing loss, which usually affects the high frequencies of hearing. The resulting poor speech recognition has a negative impact on cognitive, emotional and social function in older adults. Recent investigations revealed an association between hearing impairment and social isolation, anxiety, depression and cognitive decline in elderly. These findings emphasize the importance of diagnosis and treating hearing loss in the elderly population. Hearing aids are the most commonly used devices for treating presbycusis. The technical progress of implantable hearing devices allows an effective hearing rehabilitation even in elderly with severe hearing loss. However, most people with hearing impairments are not treated adequately. © Georg Thieme Verlag KG Stuttgart · New York.

The epigenetic landscape of age-related diseases: the geroscience perspective.

Science.gov (United States)

Gensous, Noémie; Bacalini, Maria Giulia; Pirazzini, Chiara; Marasco, Elena; Giuliani, Cristina; Ravaioli, Francesco; Mengozzi, Giacomo; Bertarelli, Claudia; Palmas, Maria Giustina; Franceschi, Claudio; Garagnani, Paolo

2017-08-01

In this review, we summarize current knowledge regarding the epigenetics of age-related diseases, focusing on those studies that have described DNA methylation landscape in cardio-vascular diseases, musculoskeletal function and frailty. We stress the importance of adopting the conceptual framework of "geroscience", which starts from the observation that advanced age is the major risk factor for several of these pathologies and aims at identifying the mechanistic links between aging and age-related diseases. DNA methylation undergoes a profound remodeling during aging, which includes global hypomethylation of the genome, hypermethylation at specific loci and an increase in inter-individual variation and in stochastic changes of DNA methylation values. These epigenetic modifications can be an important contributor to the development of age-related diseases, but our understanding on the complex relationship between the epigenetic signatures of aging and age-related disease is still poor. The most relevant results in this field come from the use of the so called "epigenetics clocks" in cohorts of subjects affected by age-related diseases. We report these studies in final section of this review.

Equations of motion according to the asymptotic post-Newtonian scheme for general relativity in the harmonic gauge

Science.gov (United States)

Arminjon, Mayeul

2005-10-01

The asymptotic scheme of post-Newtonian approximation defined for general relativity in the harmonic gauge by Futamase & Schutz (1983) is based on a family of initial data for the matter fields of a perfect fluid and for the initial metric, defining a family of weakly self-gravitating systems. We show that Weinberg’s (1972) expansion of the metric and his general expansion of the energy-momentum tensor T, as well as his expanded equations for the gravitational field and his general form of the expanded dynamical equations, apply naturally to this family. Then, following the asymptotic scheme, we derive the explicit form of the expansion of T for a perfect fluid, and the expanded fluid-dynamical equations. (These differ from those written by Weinberg.) By integrating these equations in the domain occupied by a body, we obtain a general form of the translational equations of motion for a 1PN perfect-fluid system in general relativity. To put them into a tractable form, we use an asymptotic framework for the separation parameter η, by defining a family of well-separated 1PN systems. We calculate all terms in the equations of motion up to the order η3 included. To calculate the 1PN correction part, we assume that the Newtonian motion of each body is a rigid one, and that the family is quasispherical, in the sense that in all bodies the inertia tensor comes close to being spherical as η→0. Apart from corrections that cancel for exact spherical symmetry, there is in the final equations of motion one additional term, as compared with the Lorentz-Droste (Einstein-Infeld-Hoffmann) acceleration. This term depends on the spin of the body and on its internal structure.

ROS, Cell Senescence, and Novel Molecular Mechanisms in Aging and Age-Related Diseases

Directory of Open Access Journals (Sweden)

Pierpaola Davalli

2016-01-01

Full Text Available The aging process worsens the human body functions at multiple levels, thus causing its gradual decrease to resist stress, damage, and disease. Besides changes in gene expression and metabolic control, the aging rate has been associated with the production of high levels of Reactive Oxygen Species (ROS and/or Reactive Nitrosative Species (RNS. Specific increases of ROS level have been demonstrated as potentially critical for induction and maintenance of cell senescence process. Causal connection between ROS, aging, age-related pathologies, and cell senescence is studied intensely. Senescent cells have been proposed as a target for interventions to delay the aging and its related diseases or to improve the diseases treatment. Therapeutic interventions towards senescent cells might allow restoring the health and curing the diseases that share basal processes, rather than curing each disease in separate and symptomatic way. Here, we review observations on ROS ability of inducing cell senescence through novel mechanisms that underpin aging processes. Particular emphasis is addressed to the novel mechanisms of ROS involvement in epigenetic regulation of cell senescence and aging, with the aim to individuate specific pathways, which might promote healthy lifespan and improve aging.

Age related distributive justice and claims on resources.

Science.gov (United States)

Irwin, S

1996-03-01

The ageing population structure, and claims on resources by non-working groups, are seen by many to be contributing to a growing welfare crisis. In their arguments, relations between age groups and generations will become increasingly fraught, and welfare arrangements will be undermined, as 'unacceptable' levels of taxation blight the experience of a contracting workforce, required to resource a growing welfare population. However, more seems to be known about researchers' views on distributive justice than is known about the perceptions of their subject populations. It has not been demonstrated that members of age groups share interests which are consonant with their cohort experience, or perceive their interests to be in conflict with those members of other age groups or generations. This paper analyses empirical evidence on people's perceptions of who should get, and do, what, in developing an argument that standard processes do not place age groups or generations in antagonistic relationship. Understanding the relations between age groups and generations is essential to explaining change in patterns of inequality, but the interdependence of these relations suggest that they are part of a coherent social structure, and not likely to give rise to crisis in the ways predicted.

Sarcopenia and Age-Related Endocrine Function

Directory of Open Access Journals (Sweden)

Kunihiro Sakuma

2012-01-01

Full Text Available Sarcopenia, the age-related loss of skeletal muscle, is characterized by a deterioration of muscle quantity and quality leading to a gradual slowing of movement, a decline in strength and power, and an increased risk of fall-related injuries. Since sarcopenia is largely attributed to various molecular mediators affecting fiber size, mitochondrial homeostasis, and apoptosis, numerous targets exist for drug discovery. In this paper, we summarize the current understanding of the endocrine contribution to sarcopenia and provide an update on hormonal intervention to try to improve endocrine defects. Myostatin inhibition seems to be the most interesting strategy for attenuating sarcopenia other than resistance training with amino acid supplementation. Testosterone supplementation in large amounts and at low frequency improves muscle defects with aging but has several side effects. Although IGF-I is a potent regulator of muscle mass, its therapeutic use has not had a positive effect probably due to local IGF-I resistance. Treatment with ghrelin may ameliorate the muscle atrophy elicited by age-dependent decreases in growth hormone. Ghrelin is an interesting candidate because it is orally active, avoiding the need for injections. A more comprehensive knowledge of vitamin-D-related mechanisms is needed to utilize this nutrient to prevent sarcopenia.

Relativistic phenomenological equations and transformation laws of relative coefficients

Directory of Open Access Journals (Sweden)

Patrizia Rogolino

2017-06-01

Full Text Available The aim of this paper is to derive the phenomenological equations in the context of special relativistic non-equilibrium thermodynamics with internal variables. In particular, after introducing some results developed in our previous paper, by means of classical non-equilibrium thermodynamic procedure and under suitable assumptions on the entropy density production, the phenomenological equations and transformation laws of phenomenological coefficients are derived. Finally, some symmetries of aforementioned coefficients are obtained.

Age-related variations of visuo-motor adaptation beyond explicit knowledge

Directory of Open Access Journals (Sweden)

Herbert eHeuer

2014-07-01

Full Text Available Visuo-motor adaptation suffers at older working age. The age-related decline of behavioural adjustments is accompanied by reduced explicit knowledge of the visuo-motor transformation. It disappears when explicit knowledge is kept constant across the age range, except for particularly high levels of explicit knowledge. According to these findings, at older adult age both the acquisition of explicit knowledge and its application for strategic corrections become poorer. Recently it has been posited that visuo-motor adaptation can involve model-free reinforcement mechanisms of learning in addition to model-based mechanisms. We tested whether age-related declines of reinforcement learning can also contribute to the age-related changes of visuo-motor adaptation. Therefore we enhanced the contribution of reinforcement learning to visuo-motor adaptation by way of introducing salient markers of success and failure during practice. With such modified practice conditions, there were residual age-related variations of behavioural adjustments at all levels of explicit knowledge, even when explicit knowledge was absent. The residual age-related variations were observed for practiced target directions only, but not for new target directions. These findings are consistent with an age-related decline of model-free reinforcement learning as a third factor in the age-related decline of visuo-motor adaptation. Under practice conditions, which spur model-free reward-based learning, this factor adds to the decrements of the acquisition of explicit knowledge and its use for strategic corrections.

Nutritional Considerations for Healthy Aging and Reduction in Age-Related Chronic Disease12

Science.gov (United States)

Shlisky, Julie; Bloom, David E; Beaudreault, Amy R; Tucker, Katherine L; Keller, Heather H; Freund-Levi, Yvonne; Fielding, Roger A; Cheng, Feon W; Jensen, Gordon L; Wu, Dayong; Meydani, Simin N

2017-01-01

A projected doubling in the global population of people aged ≥60 y by the year 2050 has major health and economic implications, especially in developing regions. Burdens of unhealthy aging associated with chronic noncommunicable and other age-related diseases may be largely preventable with lifestyle modification, including diet. However, as adults age they become at risk of “nutritional frailty,” which can compromise their ability to meet nutritional requirements at a time when specific nutrient needs may be high. This review highlights the role of nutrition science in promoting healthy aging and in improving the prognosis in cases of age-related diseases. It serves to identify key knowledge gaps and implementation challenges to support adequate nutrition for healthy aging, including applicability of metrics used in body-composition and diet adequacy for older adults and mechanisms to reduce nutritional frailty and to promote diet resilience. This review also discusses management recommendations for several leading chronic conditions common in aging populations, including cognitive decline and dementia, sarcopenia, and compromised immunity to infectious disease. The role of health systems in incorporating nutrition care routinely for those aged ≥60 y and living independently and current actions to address nutritional status before hospitalization and the development of disease are discussed. PMID:28096124

Quantum linear Boltzmann equation

International Nuclear Information System (INIS)

Vacchini, Bassano; Hornberger, Klaus

2009-01-01

We review the quantum version of the linear Boltzmann equation, which describes in a non-perturbative fashion, by means of scattering theory, how the quantum motion of a single test particle is affected by collisions with an ideal background gas. A heuristic derivation of this Lindblad master equation is presented, based on the requirement of translation-covariance and on the relation to the classical linear Boltzmann equation. After analyzing its general symmetry properties and the associated relaxation dynamics, we discuss a quantum Monte Carlo method for its numerical solution. We then review important limiting forms of the quantum linear Boltzmann equation, such as the case of quantum Brownian motion and pure collisional decoherence, as well as the application to matter wave optics. Finally, we point to the incorporation of quantum degeneracies and self-interactions in the gas by relating the equation to the dynamic structure factor of the ambient medium, and we provide an extension of the equation to include internal degrees of freedom.

Age-related deterioration of rod vision in mice.

Science.gov (United States)

Kolesnikov, Alexander V; Fan, Jie; Crouch, Rosalie K; Kefalov, Vladimir J

2010-08-18

Even in healthy individuals, aging leads to deterioration in visual acuity, contrast sensitivity, visual field, and dark adaptation. Little is known about the neural mechanisms that drive the age-related changes of the retina and, more specifically, photoreceptors. According to one hypothesis, the age-related deterioration in rod function is due to the limited availability of 11-cis-retinal for rod pigment formation. To determine how aging affects rod photoreceptors and to test the retinoid-deficiency hypothesis, we compared the morphological and functional properties of rods of adult and aged B6D2F1/J mice. We found that the number of rods and the length of their outer segments were significantly reduced in 2.5-year-old mice compared with 4-month-old animals. Aging also resulted in a twofold reduction in the total level of opsin in the retina. Behavioral tests revealed that scotopic visual acuity and contrast sensitivity were decreased by twofold in aged mice, and rod ERG recordings demonstrated reduced amplitudes of both a- and b-waves. Sensitivity of aged rods determined from single-cell recordings was also decreased by 1.5-fold, corresponding to not more than 1% free opsin in these photoreceptors, and kinetic parameters of dim flash response were not altered. Notably, the rate of rod dark adaptation was unaffected by age. Thus, our results argue against age-related deficiency of 11-cis-retinal in the B6D2F1/J mouse rod visual cycle. Surprisingly, the level of cellular dark noise was increased in aged rods, providing an alternative mechanism for their desensitization.

Age-related retinopathy in NRF2-deficient mice.

Directory of Open Access Journals (Sweden)

Zhenyang Zhao

2011-04-01

Full Text Available Cumulative oxidative damage is implicated in the pathogenesis of age-related macular degeneration (AMD. Nuclear factor erythroid 2-related factor 2 (NRF2 is a transcription factor that plays key roles in retinal antioxidant and detoxification responses. The purposes of this study were to determine whether NRF2-deficient mice would develop AMD-like retinal pathology with aging and to explore the underlying mechanisms.Eyes of both wild type and Nrf2(-/- mice were examined in vivo by fundus photography and electroretinography (ERG. Structural changes of the outer retina in aged animals were examined by light and electron microscopy, and immunofluorescence labeling. Our results showed that Nrf2(-/- mice developed age-dependent degenerative pathology in the retinal pigment epithelium (RPE. Drusen-like deposits, accumulation of lipofuscin, spontaneous choroidal neovascularization (CNV and sub-RPE deposition of inflammatory proteins were present in Nrf2(-/- mice after 12 months. Accumulation of autophagy-related vacuoles and multivesicular bodies was identified by electron microscopy both within the RPE and in Bruch's membrane of aged Nrf2(-/- mice.Our data suggest that disruption of Nfe2l2 gene increased the vulnerability of outer retina to age-related degeneration. NRF2-deficient mice developed ocular pathology similar to cardinal features of human AMD and deregulated autophagy is likely a mechanistic link between oxidative injury and inflammation. The Nrf2(-/- mice can provide a novel model for mechanistic and translational research on AMD.

Towards age/rotation/magnetic activity relation with seismology

Directory of Open Access Journals (Sweden)

Mathur Savita

2015-01-01

Full Text Available The knowledge of stellar ages directly impacts the characterization of a planetary system as it puts strong constraints on the moment when the system was born. Unfortunately, the determination of precise stellar ages is a very difficult task. Different methods can be used to do so (based on isochrones or chemical element abundances but they usually provide large uncertainties. During its evolution a star goes through processes leading to loss of angular momentum but also changes in its magnetic activity. Building rotation, magnetic, age relations would be an asset to infer stellar ages model independently. Several attempts to build empirical relations between rotation and age (namely gyrochronology were made with a focus on cluster stars where the age determination is easier and for young stars on the main sequence. For field stars, we can now take advantage of high-precision photometric observations where we can perform asteroseismic analyses to improve the accuracy of stellar ages. Furthermore, the variability in the light curves allow us to put strong constraints on the stellar rotation and magnetic activity. By combining these precise measurements, we are on the way of understanding and improving relations between magnetic activity, rotation, and age, in particular at different stages of stellar evolution. I will review the status on gyrochronology relationships based on observations of young cluster stars. Then I will focus on solar-like stars and describe the inferences on stellar ages, rotation, and magnetism that can be provided by high-quality photometric observations such as the ones of the Kepler mission, in particular through asteroseismic analyses.

Use of profit equations to determine relative economic value of dairy cattle herd life and production from field data.

NARCIS (Netherlands)

Arendonk, van J.A.M.

1991-01-01

Profit equations or functions that reflect the realized profitability of cows have been used in the literature to determine the relative importance of different variables such as milk yield and herd life. In all profit equations, the opportunity cost of postponed replacement, which reflects the

Memory's aging echo: age-related decline in neural reactivation of perceptual details during recollection.

Science.gov (United States)

McDonough, Ian M; Cervantes, Sasha N; Gray, Stephen J; Gallo, David A

2014-09-01

Episodic memory decline is a hallmark of normal cognitive aging. Here, we report the first event-related fMRI study to directly investigate age differences in the neural reactivation of qualitatively rich perceptual details during recollection. Younger and older adults studied pictures of complex scenes at different presentation durations along with descriptive verbal labels, and these labels subsequently were used during fMRI scanning to cue picture recollections of varying perceptual detail. As expected from prior behavioral work, the two age groups subjectively rated their recollections as containing similar amounts of perceptual detail, despite objectively measured recollection impairment in older adults. In both age groups, comparisons of retrieval trials that varied in recollected detail revealed robust activity in brain regions previously linked to recollection, including hippocampus and both medial and lateral regions of the prefrontal and posterior parietal cortex. Critically, this analysis also revealed recollection-related activity in visual processing regions that were active in an independent picture-perception task, and these regions showed age-related reductions in activity during recollection that cannot be attributed to age differences in response criteria. These fMRI findings provide new evidence that aging reduces the absolute quantity of perceptual details that are reactivated from memory, and they help to explain why aging reduces the reliability of subjective memory judgments. Copyright © 2014 Elsevier Inc. All rights reserved.

[Current concepts in pathogenesis of age-related macular degeneration].

Science.gov (United States)

Kubicka-Trząska, Agnieszka; Karska-Basta, Izabella; Romanowska-Dixon, Bożena

2014-01-01

Age-related macular degeneration is the leading cause of central blindness in elderly population of the western world. The pathogenesis of this disease, likely multifactorial, is not well known, although a number of theories have been put forward, including oxidative stress, genetic interactions, hemodynamic imbalance, immune and inflammatory processes. The understanding of age-related macular degeneration pathogenesis will give rise to new approaches in prevention and treatment of the early and late stages of both atrophic and neovascular age-related macular degeneration.

Uniaxial Tension Test of Slender Reinforced Early Age Concrete Members

Directory of Open Access Journals (Sweden)

Wenbo Zhang

2011-08-01

Full Text Available The present study aims to obtain the tensile properties of early age concrete based on a uniaxial tension test employing RC slender members. First, the paper shows that concrete strain is equal to the strain of rebar at the mid-span of the RC member. The tensile Young’s modulus and the strain capacity of early age concrete are estimated using strain measurements. The experiment indicated that the tensile Young’s modulus at an early age is higher than the compressive modulus. This observation was similar to one found in a previous investigation which used a direct tension test of early age concrete. Moreover, the paper describes how an empirical equation for mature concrete can be applied to the relation between uniaxial tensile strength and splitting tensile strength even in early age concrete. Based on a uniaxial tension test, the paper proposes an empirical equation for the relationship between standard bond stresses and relative slip.

Experience-based attenuation of age-related differences in music cognition tasks.

Science.gov (United States)

Meinz, E J

2000-06-01

Pianists of a wide experience and age range were tested on measures of musical memory and musical perceptual speed to better understand the effects of experience on age-cognition relations. Experience-related attenuation might be in the form of an Age x Experience interaction or in the form of a "confounding" of age and experience such that positive age-experience relations offset negative age-cognition relations. It was predicted that the former, considered evidence for disuse interpretations of aging, would be likely to emerge in tasks with strong experience effects and strong age-related declines among inexperienced individuals. However, in no case were the interactions of age and experience on the memory or perceptual speed variables significant. There was, however, evidence that high levels of experience in the older participants partially attenuated the negative effects of age on the memory and perceptual speed tasks.

Nutritional modulation of age-related macular degeneration

Science.gov (United States)

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated wi...

Equation with the many fathers

DEFF Research Database (Denmark)

Kragh, Helge

1984-01-01

In this essay I discuss the origin and early development of the first relativistic wave equation, known as the Klein-Gordon equation. In 1926 several physicists, among them Klein, Fock, Schrödinger, and de Broglie, announced this equation as a candidate for a relativistic generalization of the us...... as electrodynamics. Although this ambitious attempt attracted some interest in 1926, its impact on the mainstream of development in quantum mechanics was virtually nil....... of the usual Schrödinger equation. In most of the early versions the Klein-Gordon equation was connected with the general theory of relativity. Klein and some other physicists attempted to express quantum mechanics within a five-dimensional unified theory, embracing general relativity as well...

Dirac equation in very special relativity for hydrogen atom

Energy Technology Data Exchange (ETDEWEB)

Maluf, R.V., E-mail: r.v.maluf@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil); Silva, J.E.G., E-mail: euclides@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil); Cruz, W.T., E-mail: wilamicruz@gmail.com [Instituto Federal de Educação, Ciência e Tecnologia do Ceará (IFCE), Campus Juazeiro do Norte, 63040-000 Juazeiro do Norte, Ceará (Brazil); Almeida, C.A.S., E-mail: carlos@fisica.ufc.br [Universidade Federal do Ceará (UFC), Departamento de Física, Campus do Pici, Caixa Postal 6030, 60455-760 Fortaleza, Ceará (Brazil)

2014-11-10

In this work, we study the modified Dirac equation in the framework of very special relativity (VSR). The low-energy regime is accessed and the nonrelativistic Hamiltonian is obtained. It turns out that this Hamiltonian is similar to that achieved from the Standard Model Extension (SME) via coupling of the spinor field to a Lorentz-violating term, but new features arise inherited from the non-local character of the VSR. In addition, the implications of the VSR-modified Lorentz symmetry on the spectrum of a hydrogen atom are determined by calculating the first-order energy corrections in the context of standard quantum mechanics. Among the results, we highlight that the modified Hamiltonian provides non-vanishing corrections which lift the degeneracy of the energy levels and allow us to find an upper bound upon the VSR-parameter.

Age-related changes in trabecular and cortical bone microstructure.

Science.gov (United States)

Chen, Huayue; Zhou, Xiangrong; Fujita, Hiroshi; Onozuka, Minoru; Kubo, Kin-Ya

2013-01-01

The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT), micro-CT, and high resolution peripheral quantitative CT (HR-pQCT), imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

Age-related infra-tentorial brain atrophy on CT scan

International Nuclear Information System (INIS)

Kitani, Mitsuhiro; Kobayashi, Shotai; Yamaguchi, Shuhei; Okada, Kazunori; Murata, Akihiro; Tsunematsu, Tokugoro

1985-01-01

We had reported that the brain atrophy progressed significantly with advancing age using the two dimensional CT measurement by digitizer which was connected with personal computer. Using this method, we studied the age-related infra-tentrial brain atrophy in 67 normal subjects (14-90 years), and compared that with age-related supra-tentrial brain atrophy. There was a significant correlation between age and all indices [cranio-ventricular index (CVI), ventricular area index (VAI) and brain atrophy index (BAI)] in supratentrial brain. These indices did not correlated to the age in infra-tentrial brain (brainstem and cerebellum). Significant change of the brain atrophy occured above 60 years old was observed by BAI and VAI in supra-tentrial brain. There was a significant correlation between supra-tentrial brain atrophy index (BAI) and that of infratentrial brain. These results indicate that age-related brain atrophy might progress more slowly in brainstem and cerebellum than in cerebrum. (author)

On a theorem of Cattabriga related to Stokes equations

International Nuclear Information System (INIS)

Georgescu, V.

1978-01-01

We study the ''generalized Stokes boundary value problem'', which is a (generalization of a) linearized version of Navier-Stokes equations and we show the existence and unicity of the weak solution. It is known that these results can be used to prove the existence of weak (local) solutions to the Navier-Stokes equations. However, we are mainly interested in the method of proving it will be seen how easy the result follows from some general theorems about differential forms on a Riemannian manifold. (author)

Model Compaction Equation

African Journals Online (AJOL)

The currently proposed model compaction equation was derived from data sourced from the. Niger Delta and it relates porosity to depth for sandstones under hydrostatic pressure condition. The equation is useful in predicting porosity and compaction trend in hydrostatic sands of the. Niger Delta. GEOLOGICAL SETTING OF ...

The neural architecture of age-related dual-task interferences

Directory of Open Access Journals (Sweden)

Witold Xaver Chmielewski

2014-07-01

Full Text Available In daily life elderly adults exhibit deficits when dual-tasking is involved. So far these deficits have been verified on a behavioral level in dual-tasking. Yet, the neuronal architecture of these deficits in aging still remains to be explored especially when late-middle aged individuals around 60 years of age are concerned. Neuroimaging studies in young participants concerning dual-tasking were, among others, related to activity in middle frontal (MFG and superior frontal gyrus (SFG and the anterior insula (AI. According to the frontal lobe hypothesis of aging, alterations in these frontal regions (i.e., SFG and MFG might be responsible for cognitive deficits. We measured brain activity using fMRI, while examining age-dependent variations in dual-tasking by utilizing the PRP (psychological refractory period test. Behavioral data showed an increasing PRP effect in late-middle aged adults. The results suggest the age-related deteriorated performance in dual-tasking, especially in conditions of risen complexity. These effects are related to changes in networks involving the anterior insula, the SFG and the MFG. The results suggest that different cognitive subprocesses are affected that mediate the observed dual-tasking problems in late-middle aged individuals.

The neural architecture of age-related dual-task interferences.

Science.gov (United States)

Chmielewski, Witold X; Yildiz, Ali; Beste, Christian

2014-01-01

In daily life elderly adults exhibit deficits when dual-tasking is involved. So far these deficits have been verified on a behavioral level in dual-tasking. Yet, the neuronal architecture of these deficits in aging still remains to be explored especially when late-middle aged individuals around 60 years of age are concerned. Neuroimaging studies in young participants concerning dual-tasking were, among others, related to activity in middle frontal (MFG) and superior frontal gyrus (SFG) and the anterior insula (AI). According to the frontal lobe hypothesis of aging, alterations in these frontal regions (i.e., SFG and MFG) might be responsible for cognitive deficits. We measured brain activity using fMRI, while examining age-dependent variations in dual-tasking by utilizing the PRP (psychological refractory period) test. Behavioral data showed an increasing PRP effect in late-middle aged adults. The results suggest the age-related deteriorated performance in dual-tasking, especially in conditions of risen complexity. These effects are related to changes in networks involving the AI, the SFG and the MFG. The results suggest that different cognitive subprocesses are affected that mediate the observed dual-tasking problems in late-middle aged individuals.

Relative and Absolute Error Control in a Finite-Difference Method Solution of Poisson's Equation

Science.gov (United States)

Prentice, J. S. C.

2012-01-01

An algorithm for error control (absolute and relative) in the five-point finite-difference method applied to Poisson's equation is described. The algorithm is based on discretization of the domain of the problem by means of three rectilinear grids, each of different resolution. We discuss some hardware limitations associated with the algorithm,…

An estimator for the relative entropy rate of path measures for stochastic differential equations

Energy Technology Data Exchange (ETDEWEB)

Opper, Manfred, E-mail: manfred.opper@tu-berlin.de

2017-02-01

We address the problem of estimating the relative entropy rate (RER) for two stochastic processes described by stochastic differential equations. For the case where the drift of one process is known analytically, but one has only observations from the second process, we use a variational bound on the RER to construct an estimator.

Nutritional Considerations for Healthy Aging and Reduction in Age-Related Chronic Disease12

OpenAIRE

Shlisky, Julie; Bloom, David E; Beaudreault, Amy R; Tucker, Katherine L; Keller, Heather H; Freund-Levi, Yvonne; Fielding, Roger A; Cheng, Feon W; Jensen, Gordon L; Wu, Dayong; Meydani, Simin N

2017-01-01

A projected doubling in the global population of people aged ≥60 y by the year 2050 has major health and economic implications, especially in developing regions. Burdens of unhealthy aging associated with chronic noncommunicable and other age-related diseases may be largely preventable with lifestyle modification, including diet. However, as adults age they become at risk of “nutritional frailty,” which can compromise their ability to meet nutritional requirements at a time when specific nutr...

A generalized simplest equation method and its application to the Boussinesq-Burgers equation.

Science.gov (United States)

Sudao, Bilige; Wang, Xiaomin

2015-01-01

In this paper, a generalized simplest equation method is proposed to seek exact solutions of nonlinear evolution equations (NLEEs). In the method, we chose a solution expression with a variable coefficient and a variable coefficient ordinary differential auxiliary equation. This method can yield a Bäcklund transformation between NLEEs and a related constraint equation. By dealing with the constraint equation, we can derive infinite number of exact solutions for NLEEs. These solutions include the traveling wave solutions, non-traveling wave solutions, multi-soliton solutions, rational solutions, and other types of solutions. As applications, we obtained wide classes of exact solutions for the Boussinesq-Burgers equation by using the generalized simplest equation method.

Prevention of age-related macular degeneration.

Science.gov (United States)

Wong, Ian Yat Hin; Koo, Simon Chi Yan; Chan, Clement Wai Nang

2011-02-01

Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula.

Age-related macular degeneration

DEFF Research Database (Denmark)

la Cour, Morten; Kiilgaard, Jens Folke; Nissen, Mogens Holst

2002-01-01

Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian....... Smoking is probably also a risk factor. Preventive strategies using macular laser photocoagulation are under investigation, but their efficacy in preventing visual loss is as yet unproven. There is no treatment with proven efficacy for geographic atrophy. Optimal treatment for exudative AMD requires...

Age-related perspectives and emotion processing.

Science.gov (United States)

Lynchard, Nicholas A; Radvansky, Gabriel A

2012-12-01

Emotion is processed differently in younger and older adults. Older adults show a positivity effect, whereas younger adults show a negativity effect. Socioemotional selectivity theory suggests that these effects can be elicited in any age group when age-related perspectives are manipulated. To examine this, younger and older adults were oriented to actual and age-contrasting possible selves. Emotion activations were assessed using lexical decision. In line with socioemotional selectivity theory, shifts in emotion orientation varied according to perspective, with both younger and older adults showing a negativity effect when a younger adult perspective was taken and a positivity effect when an older adult perspective was taken. 2013 APA, all rights reserved

Covariant field equations in supergravity

Energy Technology Data Exchange (ETDEWEB)

Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

2017-12-15

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Covariant field equations in supergravity

International Nuclear Information System (INIS)

Vanhecke, Bram; Proeyen, Antoine van

2017-01-01

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Age-related memory decline is associated with vascular and microglial degeneration in aged rats.

Science.gov (United States)

Zhang, Rong; Kadar, Tamar; Sirimanne, Ernest; MacGibbon, Alastair; Guan, Jian

2012-12-01

The hippocampus processes memory is an early target of aging-related biological and structural lesions, leading to memory decline. With absent neurodegeneration in the hippocampus, which identified in rodent model of normal aging the pathology underlying age-related memory impairment is not complete. The effective glial-vascular networks are the key for maintaining neuronal functions. The changes of glial cells and cerebral capillaries with age may contribute to memory decline. Thus we examined age associated changes in neurons, glial phenotypes and microvasculature in the hippocampus of aged rats with memory decline. Young adult (6 months) and aged (35 months) male rats (Fisher/Norway-Brown) were used. To evaluate memory, four days of acquisition phase of Morris water maze tasks were carried out in both age groups and followed by a probe trial 2 h after the acquisition. The brains were then collected for analysis using immunochemistry. The aged rats showed a delayed latency (pvascular and microglial degeneration with reduced vascular endothelial growth factor and elevated GFAP expression in the hippocampus. The data indicate the memory decline with age is associated with neuronal dysfunction, possibly due to impaired glial-vascular-neuronal networks, but not neuronal degeneration. Glial and vascular degeneration found in aged rats may represent early event of aging pathology prior to neuronal degeneration. Copyright © 2012 Elsevier B.V. All rights reserved.

Local WKB dispersion relation for the Vlasov-Maxwell equations

International Nuclear Information System (INIS)

Berk, H.L.; Dominguez, R.R.

1982-10-01

A formalism for analyzing systems of integral equations, based on the Wentzel-Kramers-Brillouin (WKB) approximation, is applied to the Vlasov-Maxwell integral equations in an arbitrary-β, spatially inhomogenous plasma model. It is shown that when treating frequencies comparable with and larger than the cyclotron frequency, relevant new terms must be accounted for to treat waves that depend upon local spatial gradients. For a specific model, the response for very short wavelength and high frequency is shown to reduce to the straight-line orbit approximation when the WKB rules are correctly followed

Infant pain-related negative affect at 12 months of age: early infant and caregiver predictors.

Science.gov (United States)

Din Osmun, Laila; Pillai Riddell, Rebecca; Flora, David B

2014-01-01

To examine the predictive relationships of early infant and caregiver variables on expressed pain-related negative affect duration at the 12-month immunization. Infants and their caregivers (N = 255) were followed during immunization appointments over the first year of life. Latent growth curve modeling in a structural equation modeling context was used. Higher levels of initial infant pain reactivity at 2 months and caregiver emotional availability averaged across 2, 4, and 6 months of age were related to larger decreases in the duration of infant negative affect over the first 6 months of life. Longer duration of infant negative affect at 2 months and poorer regulation of infant negative affect over the first 6 months of life predicted longer durations of infant negative affect by 12 months. Infant negative affect at 12 months was a function of both infant factors and the quality of caregiver interactive behaviors (emotional availability) in early infancy.

The Schroeder functional equation and its relation to the invariant measures of chaotic maps

International Nuclear Information System (INIS)

Luevano, Jose-Ruben; Pina, Eduardo

2008-01-01

The aim of this paper is to show that the invariant measure for a class of one-dimensional chaotic maps, T(x), is an extended solution of the Schroeder functional equation, q(T(x)) = λq(x), induced by them. Hence, we give a unified treatment of a collection of exactly solved examples worked out in the current literature. In particular, we show that these examples belong to a class of functions introduced by Mira (see the text). Moreover, as a new example, we compute the invariant densities for a class of rational maps having the Weierstrass p function as an invariant one. Also, we study the relation between that equation and the well-known Frobenius-Perron and Koopman's operators

Age-Related Differences in Idiom Production in Adulthood

Science.gov (United States)

Conner, Peggy S.; Hyun, Jungmoon; O'Connor Wells, Barbara; Anema, Inge; Goral, Mira; Monereau-Merry, Marie-Michelle; Rubino, Daniel; Kuckuk, Raija; Obler, Loraine K.

2011-01-01

To investigate whether idiom production was vulnerable to age-related difficulties, we asked 40 younger (ages 18-30) and 40 older healthy adults (ages 60-85) to produce idiomatic expressions in a story-completion task. Younger adults produced significantly more correct idiom responses (73%) than did older adults (60%). When older adults generated…

On kinetic Boltzmann equations and related hydrodynamic flows with dry viscosity

Directory of Open Access Journals (Sweden)

Nikolai N. Bogoliubov (Jr.

2007-01-01

Full Text Available A two-component particle model of Boltzmann-Vlasov type kinetic equations in the form of special nonlinear integro-differential hydrodynamic systems on an infinite-dimensional functional manifold is discussed. We show that such systems are naturally connected with the nonlinear kinetic Boltzmann-Vlasov equations for some one-dimensional particle flows with pointwise interaction potential between particles. A new type of hydrodynamic two-component Benney equations is constructed and their Hamiltonian structure is analyzed.

Risk factors for age-related maculopathy.

Science.gov (United States)

Connell, Paul P; Keane, Pearse A; O'Neill, Evelyn C; Altaie, Rasha W; Loane, Edward; Neelam, Kumari; Nolan, John M; Beatty, Stephen

2009-01-01

Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

Risk Factors for Age-Related Maculopathy

Directory of Open Access Journals (Sweden)

Paul P. Connell

2009-01-01

Full Text Available Age-related maculopathy (ARM is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

Risk factors for age-related maculopathy.

LENUS (Irish Health Repository)

Connell, Paul P

2012-02-01

Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715\\/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

A Relation Between the Eikonal Equation Associated to a Potential Energy Surface and a Hyperbolic Wave Equation.

Science.gov (United States)

Bofill, Josep Maria; Quapp, Wolfgang; Caballero, Marc

2012-12-11

The potential energy surface (PES) of a molecule can be decomposed into equipotential hypersurfaces. We show in this article that the hypersurfaces are the wave fronts of a certain hyperbolic partial differential equation, a wave equation. It is connected with the gradient lines, or the steepest descent, or the steepest ascent lines of the PES. The energy seen as a reaction coordinate plays the central role in this treatment.

[Depression in Patients with Age-Related Macular Degeneration].

Science.gov (United States)

Narváez, Yamile Reveiz; Gómez-Restrepo, Carlos

2012-09-01

Age-related macular degeneration is a cause for disability in the elderly since it greatly affects their quality of life and increases depression likelihood. This article discusses the negative effect depression has on patients with age-related macular degeneration and summarizes the interventions available for decreasing their depression index. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

A Structural Equation Model of HIV-related Symptoms, Depressive Symptoms, and Medication Adherence.

Science.gov (United States)

Yoo-Jeong, Moka; Waldrop-Valverde, Drenna; McCoy, Katryna; Ownby, Raymond L

2016-05-01

Adherence to combined antiretroviral therapy (cART) remains critical in management of HIV infection. This study evaluated depression as a potential mechanism by which HIV-related symptoms affect medication adherence and explored if particular clusters of HIV symptoms are susceptible to this mechanism. Baseline data from a multi-visit intervention study were analyzed among 124 persons living with HIV (PLWH). A bifactor model showed two clusters of HIV-related symptom distress: general HIV-related symptoms and gastrointestinal (GI) symptoms. Structural equation modeling showed that both general HIV-related symptoms and GI symptoms were related to higher levels of depressive symptoms, and higher levels of depressive symptoms were related to lower levels of medication adherence. Although general HIV-related symptoms and GI symptoms were not directly related to adherence, they were indirectly associated with adherence via depression. The findings highlight the importance of early recognition and evaluation of symptoms of depression, as well as the underlying physical symptoms that might cause depression, to improve medication adherence.

KCNQ channels regulate age-related memory impairment.

Directory of Open Access Journals (Sweden)

Sonia Cavaliere

Full Text Available In humans KCNQ2/3 heteromeric channels form an M-current that acts as a brake on neuronal excitability, with mutations causing a form of epilepsy. The M-current has been shown to be a key regulator of neuronal plasticity underlying associative memory and ethanol response in mammals. Previous work has shown that many of the molecules and plasticity mechanisms underlying changes in alcohol behaviour and addiction are shared with those of memory. We show that the single KCNQ channel in Drosophila (dKCNQ when mutated show decrements in associative short- and long-term memory, with KCNQ function in the mushroom body α/βneurons being required for short-term memory. Ethanol disrupts memory in wildtype flies, but not in a KCNQ null mutant background suggesting KCNQ maybe a direct target of ethanol, the blockade of which interferes with the plasticity machinery required for memory formation. We show that as in humans, Drosophila display age-related memory impairment with the KCNQ mutant memory defect mimicking the effect of age on memory. Expression of KCNQ normally decreases in aging brains and KCNQ overexpression in the mushroom body neurons of KCNQ mutants restores age-related memory impairment. Therefore KCNQ is a central plasticity molecule that regulates age dependent memory impairment.

Targeting Mitochondria to Counteract Age-Related Cellular Dysfunction

Directory of Open Access Journals (Sweden)

Corina T. Madreiter-Sokolowski

2018-03-01

Full Text Available Senescence is related to the loss of cellular homeostasis and functions, which leads to a progressive decline in physiological ability and to aging-associated diseases. Since mitochondria are essential to energy supply, cell differentiation, cell cycle control, intracellular signaling and Ca2+ sequestration, fine-tuning mitochondrial activity appropriately, is a tightrope walk during aging. For instance, the mitochondrial oxidative phosphorylation (OXPHOS ensures a supply of adenosine triphosphate (ATP, but is also the main source of potentially harmful levels of reactive oxygen species (ROS. Moreover, mitochondrial function is strongly linked to mitochondrial Ca2+ homeostasis and mitochondrial shape, which undergo various alterations during aging. Since mitochondria play such a critical role in an organism’s process of aging, they also offer promising targets for manipulation of senescent cellular functions. Accordingly, interventions delaying the onset of age-associated disorders involve the manipulation of mitochondrial function, including caloric restriction (CR or exercise, as well as drugs, such as metformin, aspirin, and polyphenols. In this review, we discuss mitochondria’s role in and impact on cellular aging and their potential to serve as a target for therapeutic interventions against age-related cellular dysfunction.

Equations for the gravitational field and local conserved quantities in the general theory of relativity

International Nuclear Information System (INIS)

Manoff, S.

1979-07-01

By utilization of the method of Lagrangians with covariant derivatives (MLCD) the different energy-momentum tensors (canonical, generalized canonical, symmetrical) and the relations between them are considered. On this basis, Einstein's theory of gravitation is studied as a field theory with a Lagrangian density of the type Lsub(g)=√-g.Lsub(g)(gsub(ij),Rsub(A)), (Rsub(A)=Rsub(ijkl)). It is shown that the energy-momentum tensors of the gravitational field can be defined for this theory. The symmetrical energy-momentum tensor of the gravitational field sub(gs)Tsub(k)sup(i), which in the general case is not a local conserved quantity (sub(gs)Tsub(k)sup(i)sub(;i) unequal 0) (in contrast to the material fields satisfying condition sub(Ms)Tsub(k)sup(i)sub(;i) = 0), is equal to zero for the gravitational field in vacuum (cosmological constant Λ = 0). Equations of the gravitational field of a new type are suggested, leading to equations of motion (sub(Ms)Tsub(k)sup(i) + sub(gs)Tsub(k)sup(i))sub(;i) = 0. The equations corresponding to the Lagrangian density Lsub(g)=(√-g/kappasub(o)) (R - lambda approximately), lambda approximately = const., are considered. The equations of Einstein Rsub(ij) = 0 are obtained in the case of gravitational field in vacuum. Some particular cases are examined as an illustration to material fields and the corresponding gravitational equations. (author)

Reduced Braginskii equations

International Nuclear Information System (INIS)

Yagi, M.; Horton, W.

1993-11-01

A set of reduced Braginskii equations is derived without assuming flute ordering and the Boussinesq approximation. These model equations conserve the physical energy. It is crucial at finite β that we solve the perpendicular component of Ohm's law to conserve the physical energy while ensuring the relation ∇ · j = 0

Gender, age, and sport differences in relative age effects among US Masters swimming and track and field athletes.

Science.gov (United States)

Medic, Nikola; Young, Bradley W; Starkes, Janet L; Weir, Patricia L; Grove, J Robert

2009-12-01

A relative age effect has been identified in Masters sports (Medic, Starkes, & Young, 2007). Since gender, age, and type of sport have been found to influence the relative age effect in youth sports (Musch & Grondin, 2001), we examined how these three variables influenced possible relative age effects among Masters swimmers and track and field athletes. Using archived data between 1996 and 2006, frequency of participation entries and record-setting performances at the US Masters championships were examined as a function of an individual's constituent year within any 5-year age category. Study 1 investigated the frequency of Master athletes who participated; Study 2 examined the frequency of performance records that were set across constituent years within an age category, while accounting for the distribution of participation frequencies. Results showed that a participation-related relative age effect in Masters sports is stronger for males, that it becomes progressively stronger with each successive decade of life, and that it does not differ across track and field and swimming. In addition, a performance-related relative age effect in Masters sport seems to be stronger for swimming than track and field, but it does not differ across gender and decades of life.

Extrinsic Mechanisms Involved in Age-Related Defective Bone Formation

DEFF Research Database (Denmark)

Trinquier, Anne Marie-Pierre Emilie; Kassem, Moustapha

2011-01-01

Context: Age-related bone loss is associated with progressive changes in bone remodeling characterized by decreased bone formation relative to bone resorption. Both trabecular and periosteal bone formation decline with age in both sexes, which contributes to bone fragility and increased risk of f...

Age-Related Changes in Trabecular and Cortical Bone Microstructure

Directory of Open Access Journals (Sweden)

Huayue Chen

2013-01-01

Full Text Available The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT, micro-CT, and high resolution peripheral quantitative CT (HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

[Pharmacological therapy of age-related macular degeneration based on etiopathogenesis].

Science.gov (United States)

Fischer, Tamás

2015-11-15

It is of great therapeutic significance that disordered function of the vascular endothelium which supply the affected ocular structures plays a major role in the pathogenesis and development of age-related macular degeneration. Chronic inflammation is closely linked to diseases associated with endothelial dysfunction, and age-related macular degeneration is accompanied by a general inflammatory response. According to current concept, age-related macular degeneration is a local manifestation of systemic vascular disease. This recognition could have therapeutic implications because restoration of endothelial dysfunction can restabilize the condition of chronic vascular disease including age-related macular degeneration as well. Restoration of endothelial dysfunction by pharmaacological or non pharmacological interventions may prevent the development or improve endothelial dysfunction, which result in prevention or improvement of age related macular degeneration as well. Medicines including inhibitors of the renin-angiotensin system (converting enzyme inhibitors, angiotensin-receptor blockers and renin inhibitors), statins, acetylsalicylic acid, trimetazidin, third generation beta-blockers, peroxisome proliferator-activated receptor gamma agonists, folate, vitamin D, melatonin, advanced glycation end-product crosslink breaker alagebrium, endothelin-receptor antagonist bosentan, coenzyme Q10; "causal" antioxidant vitamins, N-acetyl-cysteine, resveratrol, L-arginine, serotonin receptor agonists, tumor necrosis factor-alpha blockers, specific inhibitor of the complement alternative pathway, curcumin and doxycyclin all have beneficial effects on endothelial dysfunction. Restoration of endothelial dysfunction can restabilize chronic vascular disease including age-related macular degeneration as well. Considering that the human vascular system is consubstantial, medicines listed above should be given to patients (1) who have no macular degeneration but have risk factors

eNOS-uncoupling in age-related erectile dysfunction

OpenAIRE

Johnson, JM; Bivalacqua, TJ; Lagoda, GA; Burnett, AL; Musicki, B

2011-01-01

Aging is associated with ED. Although age-related ED is attributed largely to increased oxidative stress and endothelial dysfunction in the penis, the molecular mechanisms underlying this effect are not fully defined. We evaluated whether endothelial nitric oxide synthase (eNOS) uncoupling in the aged rat penis is a contributing mechanism. Correlatively, we evaluated the effect of replacement with eNOS cofactor tetrahydrobiopterin (BH4) on erectile function in the aged rats. Male Fischer 344 ...

Fruits, Nuts, and Brain Aging: Nutritional Interventions Targeting Age-Related Neuronal and Behavioral Deficits

Science.gov (United States)

By the year 2050, 30% of the total population of the US will be over 65 years of age. As the aged population expands, the economic burden of care and treatment of those with age-related health disorders also increases, necessitating the immediate implementation of therapeutics to prevent or even rev...

Development of age-related maculopathy: a histochemical and molecular approach

NARCIS (Netherlands)

A.C. Lambooij (Antoinette)

2002-01-01

textabstractAge-related maculopathy (ARM) is a severe threat to the visual ability of people over 65 years of age. In the late stages of ARM, called age-related macular degeneration (AMD), photoreceptor cells gradually disappear. New vessels growing beneath the retina may complicateb the disease;

Reduced Braginskii equations

Energy Technology Data Exchange (ETDEWEB)

Yagi, M. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Horton, W. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

1993-11-01

A set of reduced Braginskii equations is derived without assuming flute ordering and the Boussinesq approximation. These model equations conserve the physical energy. It is crucial at finite {beta} that we solve the perpendicular component of Ohm`s law to conserve the physical energy while ensuring the relation {del} {center_dot} j = 0.

Public opinion on age-related degradation in nuclear power plants

International Nuclear Information System (INIS)

Matsuda, Toshihiro

2005-01-01

The first objective of this study is to shed light on the public opinion on age-related degradation at nuclear power plants, namely, on how the general public recognizes or views age-related degradation, which is a safety-related issue and one of the factors contributing to accidents and failures which occur at nuclear power plants. The second objective is to look into the impacts of the accident at Mihama Unit 3, which was caused by a failure to check on the piping wall thickness, on the public opinion on age-related degradation. The first survey was conducted in August 2003, followed by the second survey in October 2004, two months after the accident. The surveys found that the age-related degradation is being perceived by people as one of the risk factors that affect the safety of nuclear power plants. The characteristics of the citizens' perceptions toward age-related degradation in the form of piping cracks are that: (a) many respondents feel uneasy but a relatively few people consider that nuclear operators are technologically capable of coping with this problem; (b) many people believe that radioactivity may be released; and (c) numerous respondents consider that signs of cracks must be thoroughly detected through inspections, while on the other hand, a large percentage of the respondents attribute the accident to improper inspections/maintenance. Based on these results, the government and nuclear operators are expected to give most illuminating explanation on the current situation of and remedial measures against age-related degradation at nuclear power plants. As for the effects of the Mihama-3 accident on the public opinion on age-related degradation, it was revealed that the accident has not so significantly affected the general view for the safety of nuclear power plants, but has newly or strongly aroused people's consciousness of two of the risk factors - improper inspections/maintenance and the age-related degradation of piping. (author)

Reviewing fluid systems for age-related degradation

International Nuclear Information System (INIS)

Smith, Stan

1991-01-01

Yankee Atomic Electric Company has developed the component degradation assessment tool (CoDAT), an expert system, that aids in handling and evaluating the large amounts of data required to support the license renewal process for nuclear power station fluid systems. In 1990, CoDAT evaluated the Yankee Nuclear Power Station fluid systems for age-related degradation. Its results are now being used to help focus the plant's maintenance programs and manage the expected degradation. CoDAT uses 'If-Then' rules, developed from industry codes, standards and publications, to determine the potential for 19 age-related degradation mechanisms. Other nuclear utilities pursuing the license renewal option also could use CoDAT. (author)

Alcohol consumption, smoking and development of visible age-related signs

DEFF Research Database (Denmark)

Schou, Anne L; Mølbak, Marie-Louise; Schnor, Peter

2017-01-01

age-related signs (arcus corneae, xanthelasmata, earlobe crease and male pattern baldness). METHODS: We used information from 11 613 individuals in the Copenhagen City Heart Study (1976-2003). Alcohol intake, smoking habits and other lifestyle factors were assessed prospectively and visible age......BACKGROUND: Visible age-related signs indicate biological age, as individuals that appear old for their age are more likely to be at poor health, compared with people that appear their actual age. The aim of this study was to investigate whether alcohol and smoking are associated with four visible......-related signs were inspected during subsequent examinations. RESULTS: The risk of developing arcus corneae, earlobe crease and xanthelasmata increased stepwise with increased smoking as measured by pack-years. For alcohol consumption, a high intake was associated with the risk of developing arcus corneae...

Self-reported optometric practise patterns in age-related macular degeneration.

Science.gov (United States)

Ly, Angelica; Nivison-Smith, Lisa; Zangerl, Barbara; Assaad, Nagi; Kalloniatis, Michael

2017-11-01

The use of advanced imaging in clinical practice is emerging and the use of this technology by optometrists in assessing patients with age-related macular degeneration is of interest. Therefore, this study explored contemporary, self-reported patterns of practice regarding age-related macular degeneration diagnosis and management using a cross-sectional survey of optometrists in Australia and New Zealand. Practising optometrists were surveyed on four key areas, namely, demographics, clinical skills and experience, assessment and management of age-related macular degeneration. Questions pertaining to self-rated competency, knowledge and attitudes used a five-point Likert scale. Completed responses were received from 127 and 87 practising optometrists in Australia and New Zealand, respectively. Advanced imaging showed greater variation in service delivery than traditional techniques (such as slitlamp funduscopy) and trended toward optical coherence tomography, which was routinely performed in age-related macular degeneration by 49 per cent of respondents. Optical coherence tomography was also associated with higher self-rated competency, knowledge and perceived relevance to practice than other modalities. Most respondents (93 per cent) indicated that they regularly applied patient symptoms, case history, visual function results and signs from traditional testing, when queried about their management of patients with age-related macular degeneration. Over half (63 per cent) also considered advanced imaging, while 31 per cent additionally considered all of these as well as the disease stage and clinical guidelines. Contrary to the evidence base, 68 and 34 per cent rated nutritional supplements as highly relevant or relevant in early age-related macular degeneration and normal aging changes, respectively. These results highlight the emergence of multimodal and advanced imaging (especially optical coherence tomography) in the assessment of age-related macular degeneration

Age and work-related motives : Results of a meta-analysis

NARCIS (Netherlands)

Kooij, Dorien T. A. M.; De Lange, Annet H.; Jansen, Paul G. W.; Kanfer, Ruth; Dikkers, Josje S. E.

An updated literature review was conducted and a meta-analysis was performed to investigate the relationship between age and work-related motives. Building on theorizing in life span psychology, we hypothesized the existence of age-related differences in work-related motives. Specifically, we

Age and work-related motives: Results of a meta-analysis

NARCIS (Netherlands)

Kooij, D.T.A.M.; Lange, A.H. de; Jansen, P.G.W.; Kanfer, R.; Dikkers, J.S.E.

2011-01-01

An updated literature review was conducted and a meta-analysis was performed to investigate the relationship between age and work-related motives. Building on theorizing in life span psychology, we hypothesized the existence of age-related differences in work-related motives. Specifically, we

Evidence of the relative age effect in football in Australia.

Science.gov (United States)

van den Honert, Robin

2012-01-01

The birth date distributions of elite male and female footballers in Australia, from junior youth (age 14 and upwards) to senior (professional) players, were examined. A statistically significant relative age effect was found among junior male players, reducing in effect with increasing age. An inter-year relative age effect that became apparent among the players at national level in the Under-17 and Under-20 age groups, due to the timing of the respective World Cups for those age groups, was also identified. It is conjectured that this might lead to players born in certain years having a curtailed pathway in the elite game, leading to drop-out among this very elite group. In the case of women elite players, no significant relative age effect was found among youth players, possibly due to less fierce competition for places, although a significant effect was found to exist at senior elite level.

A large, population-based study of age-related associations between vaginal pH and human papillomavirus infection.

Science.gov (United States)

Clarke, Megan A; Rodriguez, Ana Cecilia; Gage, Julia C; Herrero, Rolando; Hildesheim, Allan; Wacholder, Sholom; Burk, Robert; Schiffman, Mark

2012-02-08

Vaginal pH is related to genital tract inflammation and changes in the bacterial flora, both suggested cofactors for persistence of human papillomavirus (HPV) infection. To evaluate the relationship between vaginal pH and HPV, we analyzed data from our large population-based study in Guanacaste, Costa Rica. We examined vaginal pH and the risk of HPV infection, cytological abnormalities, and C. trachomatis infection. Our study included 9,165 women aged 18-97 at enrollment with a total of 28,915 visits (mean length of follow-up = 3.4 years). Generalized estimating equations were used to evaluate the relationship between vaginal pH and HPV infection (both overall and single versus multiple types) and low-grade squamous intraepithelial lesions (LSIL), the cytomorphic manifestation of HPV infection. The relationship between enrollment vaginal pH and C. trachomatis infection was assessed by logistic regression. Results were stratified by age at visit. Detection of HPV was positively associated with vaginal pH, mainly in women vaginal pH was associated with 30% greater risk of infection with multiple HPV types and with LSIL, predominantly in women younger than 35 and 65+ years of age. Detection of C. trachomatis DNA was associated with increased vaginal pH in women vaginal pH in a more complex assessment of hormonal changes and the cervicovaginal microbiome as they relate to the natural history of cervical neoplasia.

What Is Age-Related Macular Degeneration?

Science.gov (United States)

... Eye Health / Eye Health A-Z Age-Related Macular Degeneration Sections What Is Macular Degeneration? How is AMD ... What Does Macular Degeneration Look Like? What Is Macular Degeneration? Leer en Español: ¿Qué es la degeneración macular ...

Parainflammation, chronic inflammation and age-related macular degeneration

Science.gov (United States)

Chen, Mei; Xu, Heping

2016-01-01

Inflammation is an adaptive response of the immune system to noxious insults to maintain homeostasis and restore functionality. The retina is considered an immune privileged tissue due to its unique anatomical and physiological properties. During aging, the retina suffers from a low-grade chronic oxidative insult, which sustains for decades and increases in level with advancing age. As a result, the retinal innate immune system, particularly microglia and the complement system, undergo low levels of activation (para-inflammation). In many cases, this para-inflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration (AMD), this para-inflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal para-inflammation include genetic predisposition, environmental risk factors and old age. Dysregulated para-inflammation (chronic inflammation) in AMD damages the blood retina barrier (BRB), resulting in the breach of retinal immune privilege leading to the development of retinal lesions. This review discusses the basic principles of retinal innate immune responses to endogenous chronic insults in normal aging and in AMD, and explores the difference between beneficial para-inflammation and the detrimental chronic inflammation in the context of AMD. PMID:26292978

Gender differences in age-related decline in regional cerebral glucose metabolism

International Nuclear Information System (INIS)

Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Park, Hyun Soo; Lee, Eun Ju; Kim, Yu Kyeong; Kim, Sang Sun

2007-01-01

In this study, we investigated gender differences in age-related declines in regional cerebral glucose metabolism using FDG-PET in a large population sample with a broad age range. 230 healthy subjects (90 male; age: 34-80 y, 140 females; age: 33-82 y) participated. Correlation maps showing age related declines in glucose uptake were created separately for each gender in SPM2. Using population-based probabilistic volume of interests (VOIs), VOIs were defined for the regions showing significant decline with aging. Age related declines were separately assessed within each age range using analysis of covariate in SPSS 13.0. In the total population without gender effect, age-related negative correlation of glucose metabolism was found in the bilateral inferior frontal gyri, bilateral caudate, bilateral thalamus, left insula, left superior frontal gyrus, left uncus, right superior temporal gyrus, right medial frontal gyrus, right parahippocampal gyrus, right anterior cingulate gyrus (P < 0.001 corrected, extent threshold k = 100). 14 VOIs values of brain regions were calculated based on this negative correlation results. The rate of decline across all defined VOIs assessed in the age category of 'more than 70' referenced to the category of '30- 39years' were 7.85% in the entire sample; 7.62% in male and 8.09% in female. Detailed analyses of declines in each age range showed separable patterns of declines across gender. In males, greater decline was observed after the age 60 (20.45%) than the ages of 30 and 50(7.98%). Whereas in females, greater declines were found in age 60s (20.15%) compared to 50s, and in 40(14.84%) compared to 30s. Age-related decline in cerebral glucose metabolism was found in both genders. We further observed that males show a relatively constant pattern of decline across a life span; whereas, females show a pattern of steep changes aging to 60s and to 40s, which may be related to changes in sex hormone levels after menopause

Gender differences in age-related decline in regional cerebral glucose metabolism

Energy Technology Data Exchange (ETDEWEB)

Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Park, Hyun Soo; Lee, Eun Ju; Kim, Yu Kyeong; Kim, Sang Sun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

2007-07-01

In this study, we investigated gender differences in age-related declines in regional cerebral glucose metabolism using FDG-PET in a large population sample with a broad age range. 230 healthy subjects (90 male; age: 34-80 y, 140 females; age: 33-82 y) participated. Correlation maps showing age related declines in glucose uptake were created separately for each gender in SPM2. Using population-based probabilistic volume of interests (VOIs), VOIs were defined for the regions showing significant decline with aging. Age related declines were separately assessed within each age range using analysis of covariate in SPSS 13.0. In the total population without gender effect, age-related negative correlation of glucose metabolism was found in the bilateral inferior frontal gyri, bilateral caudate, bilateral thalamus, left insula, left superior frontal gyrus, left uncus, right superior temporal gyrus, right medial frontal gyrus, right parahippocampal gyrus, right anterior cingulate gyrus (P < 0.001 corrected, extent threshold k = 100). 14 VOIs values of brain regions were calculated based on this negative correlation results. The rate of decline across all defined VOIs assessed in the age category of 'more than 70' referenced to the category of '30- 39years' were 7.85% in the entire sample; 7.62% in male and 8.09% in female. Detailed analyses of declines in each age range showed separable patterns of declines across gender. In males, greater decline was observed after the age 60 (20.45%) than the ages of 30 and 50(7.98%). Whereas in females, greater declines were found in age 60s (20.15%) compared to 50s, and in 40(14.84%) compared to 30s. Age-related decline in cerebral glucose metabolism was found in both genders. We further observed that males show a relatively constant pattern of decline across a life span; whereas, females show a pattern of steep changes aging to 60s and to 40s, which may be related to changes in sex hormone levels after menopause.

Factors related to accelerometer-derived physical activity in Pacific children aged 6 years.

Science.gov (United States)

Oliver, Melody; Schluter, Philip J; Schofield, Grant M; Paterson, Janis

2011-01-01

The objective of this study was to investigate potential factors related to Pacific children's moderate-to-vigorous physical activity (MVPA). A total of 393 Pacific children aged 6 years and their mothers were invited to participate. Participants wore accelerometers over 8 days; height, weight, and waist circumference were measured, and mothers reported on individual, social, and perceived environmental factors. Generalized estimation equation models were used to identify associates of children's daily MVPA. In all, 135 children and 91 mothers were included in analyses. Children spent 24% of time in MVPA; 99% of days had ≥60 minutes of MVPA. Higher maternal MVPA, male sex, longer sunlight hours, and rain-free days were associated with children's MVPA. Approaches for improving activity in Pacific children may be most efficacious if strategies for inclement weather and the encouragement of activity in mothers and, in particular, their daughters are included. Also, 60 minutes of daily MVPA may be insufficient to protect Pacific children from increased body size.

Telomere in Aging and Age-Related Diseases

Directory of Open Access Journals (Sweden)

Anna Meiliana

2017-12-01

Full Text Available BACKGROUND: The number of elderly population in the world keep increasing. In their advanced ages, many elderly face years of disability because of multiple chronic diseases, frailty, making them lost their independence. Consequently, this could have impacts on social and economic stability. A huge challenge has been sent for biomedical researchers to compress or at least eliminate this period of disability and increase the health span. CONTENT: Over the past decades, many studies of telomere biology have demonstrated that telomeres and telomere-associated proteins are implicated in human diseases. Accelerated telomere erosion was clearly correlated with a pack of metabolic and inflammatory diseases. Critically short telomeres or the unprotected end, are likely to form telomeric fusion, generating genomic instability, the cornerstone for carcinogenesis. Enlightening how telomeres involved in the mechanisms underlying the diseases’ pathogenesis was expected to uncover new molecular targets for any important diagnosis or therapeutic implications. SUMMARY: Telomere shortening was foreseen as an imporant mechanism to supress tumor by limiting cellular proliferative capacity by regulating senescence check point activation. Many human diseases and carcinogenesis are causally related to defective telomeres, asserting the importance of telomeres sustainment. Thus, telomere length assessment might serve as an important tool for clinical prognostic, diagnostic, monitoring and management. KEYWORDS: telomerase, cellular senescence, aging, cancer

Heart Failure as an Aging-Related Phenotype.

Science.gov (United States)

Morita, Hiroyuki; Komuro, Issei

2018-01-27

The molecular pathophysiology of heart failure, which is one of the leading causes of mortality, is not yet fully understood. Heart failure can be regarded as a systemic syndrome of aging-related phenotypes. Wnt/β-catenin signaling and the p53 pathway, both of which are key regulators of aging, have been demonstrated to play a critical role in the pathogenesis of heart failure. Circulating C1q was identified as a novel activator of Wnt/β-catenin signaling, promoting systemic aging-related phenotypes including sarcopenia and heart failure. On the other hand, p53 induces the apoptosis of cardiomyocytes in the failing heart. In these molecular mechanisms, the cross-talk between cardiomyocytes and non-cardiomyocytes (e,g,. endothelial cells, fibroblasts, smooth muscle cells, macrophages) deserves mentioning. In this review, we summarize recent advances in the understanding of the molecular pathophysiology underlying heart failure, focusing on Wnt/β-catenin signaling and the p53 pathway.

Generalized Lorentz-Force equations

International Nuclear Information System (INIS)

Yamaleev, R.M.

2001-01-01

Guided by Nambu (n+1)-dimensional phase space formalism we build a new system of dynamic equations. These equations describe a dynamic state of the corporeal system composed of n subsystems. The dynamic equations are formulated in terms of dynamic variables of the subsystems as well as in terms of dynamic variables of the corporeal system. These two sets of variables are related respectively as roots and coefficients of the n-degree polynomial equation. In the special n=2 case, this formalism reproduces relativistic dynamics for the charged spinning particles

Nutritional influences on epigenetics and age-related disease

Science.gov (United States)

Nutritional epigenetics has emerged as a novel mechanism underlying gene–diet interactions, further elucidating the modulatory role of nutrition in aging and age-related disease development. Epigenetics is defined as a heritable modification to the DNA that regulates chromosome architecture and modu...

Liouville's equation and radiative acceleration in general relativity

International Nuclear Information System (INIS)

Keane, A.J.

1999-01-01

This thesis examines thoroughly the general motion of a material charged particle in the intense radiation field of a static spherically symmetric compact object with spherical emitting surface outside the Schwarzschild radius. Such a test particle will be pulled in by the gravitational attraction of the compact object and pushed out by the radiation pressure force, therefore the types of trajectory admitted will depend the gravitational field, the radiation field and the particle cross-section. The presence of a strong gravitational field demands a fully general relativistic treatment of the problem. This type of calculation is interesting not only as a formal problem in general relativity but also since it has important astrophysical implications, for example, application to astrophysical discs and jets. In chapter 1 we review the classical radiation force problem and outline the transition to a fully general relativistic scenario. We discuss the method for obtaining the radiation pressure force and calculating the particle trajectories. We review previous work in this area and outline the aims of the thesis. Then we consider some astrophysical applications and discuss how realistic our calculations are. In chapter 2 we give an introduction and overview of differential geometry as this is necessary for an accurate description of tensors on a curved manifold. Then we review the general theory of relativity and in particular obtain the Schwarzschild metric describing a static spherically symmetric vacuum spacetime. Chapter 3 deals with test particle motion through a curved spacetime. Liouville's equation describes the statistical distribution in phase space of a collection of test particles and is based upon a Hamiltonian formulation of the dynamical system - this material also relies heavily upon the concepts of differential geometry introduced in chapter 2. In particular we are interested in photon transport and find the general solutions for some symmetric

Obesity related factors in school-aged children.

Science.gov (United States)

Soltani, Parvaneh Reza; Ghanbari, Atefeh; Rad, Afagh Hasanzadeh

2013-05-01

Overweight and obesity is becoming an increasingly prevalent problem in both developed and developing world, and is one of the most serious public health challenges of the 21(st) century. Although various studies demonstrated pediatric obesity-related factors, but, due to its ongoing hazardous effects, researchers aimed to assess obesity-related factors in school-aged children in Rasht, Iran. This was a case-control study which was performed in eight primary schools of Rasht. A cluster sampling method was used to select 320 students including 80 in case (BMI ≥85(th) percentile for age and gender) and 240 in control group (BMI = 5(th)-85(th) percentile for age and gender). Data were collected by a scale, a tape meter, and a form which consisted of obesity-related factors, and were analyzed by Chi-square, Mann-Whitney, and stepwise multivariate regression tests in SPSS 19. Findings showed that the mean and standard deviation of birth weight (g) in case and control groups were 3671 ± 5.64 and 190 ± 5.46, respectively (P = 0.000). 82.5% of case and 92.9% of control group had exclusive breastfeeding for 4-6 months (P = 0.024). Also, multivariate regression analysis indicated that birth weight, age, exclusive breastfeeding, and frequency of meals have significant effects on body mass index (BMI). It seems that more accurate interventions for primordial prevention are essential to reduce childhood obesity risk factors, including promotion of pre-pregnancy and prenatal care to have neonates who are appropriate for gestational age and also improving exclusive breastfeeding in the first 6 months of life. In addition, identifying children at risk for adolescent obesity provides physicians and midwives with an opportunity for earlier intervention with the goal of limiting the progression of abnormal weight gain.

Radiation-related ophthalmologic changes and aging among the atomic bomb survivors

International Nuclear Information System (INIS)

Otake, Masanori; Finch, S.C.; Choshi, Kanji; Takaku, Isao; Mishima, Hiromu; Takase, Tomoko.

1993-05-01

The relationship of ionizing radiation to the age-related ophthalmologic findings of the 1978-80 ophthalmologic examination of the atomic bomb (A-bomb) survivors of Hiroshima and Nagasaki has been reanalyzed using Dosimetry System 1986 eye organ dose estimates. The main purpose of this re-evaluation was to determine whether age and radiation exposure have an additive, synergistic, or antagonistic effect on ophthalmologic changes. The best model fitting axial opacities gives a significant positive effect for both linear dose-response and linear age-related regression coefficients and a significant negative effect for an interaction between radiation dose and age. Such a negative interaction implies an antagonistic effect in that the relative risks with relation to radiation doses decrease with increasing age. This phenomenon suggests that the lenses of younger persons are more sensitive to radiation than are those of older persons. However, the best-fitting relationship for posterior subcapsular changes suggested a linear-quadratic dose response and linear age-related effects. The quadratic estimate of radiation dose squared showed a highly significant effect with a negative trend, but the negative quadratic estimate was so extremely small it had almost no contributive value within an appropriative dose area. These data suggest an additive relationship between aging and radiation for the induction of posterior subcapsular changes, and they also indicate that there is no distinct evidence of a radiation-induced aging effect. The radiation-related relative risks increase with a log linearity. The decrease of visual acuity and accommodation with increasing age were comparable in both exposed and control subjects, with age-related visual acuity decreasing more than accommodation. (J.P.N.)

Test equating methods and practices

CERN Document Server

Kolen, Michael J

1995-01-01

In recent years, many researchers in the psychology and statistical communities have paid increasing attention to test equating as issues of using multiple test forms have arisen and in response to criticisms of traditional testing techniques This book provides a practically oriented introduction to test equating which both discusses the most frequently used equating methodologies and covers many of the practical issues involved The main themes are - the purpose of equating - distinguishing between equating and related methodologies - the importance of test equating to test development and quality control - the differences between equating properties, equating designs, and equating methods - equating error, and the underlying statistical assumptions for equating The authors are acknowledged experts in the field, and the book is based on numerous courses and seminars they have presented As a result, educators, psychometricians, professionals in measurement, statisticians, and students coming to the subject for...

Age Differences in Text Processing: The Role of Working Memory, Inhibition, and Processing Speed

OpenAIRE

BORELLA ERIKA; GHISLETTA PAOLO; DE RIBAUPIERRE ANIK

2011-01-01

Objectives. Age-related changes in the efficiency of various general cognitive mechanisms have been evoked to account for age-related differences between young and older adults in text comprehension performance. Using structural equation modeling, we investigate the relationship between age, working memory (WM), inhibition-related mechanisms, processing speed, and text comprehension, focusing on surface and text-based levels of processing. Methods. Eighty-nine younger (M = 23.11 years) and 10...

Mathematical Model of Age Aggression

OpenAIRE

Golovinski, P. A.

2013-01-01

We formulate a mathematical model of competition for resources between representatives of different age groups. A nonlinear kinetic integral-differential equation of the age aggression describes the process of redistribution of resources. It is shown that the equation of the age aggression has a stationary solution, in the absence of age-dependency in the interaction of different age groups. A numerical simulation of the evolution of resources for different initial distributions has done. It ...

Multiple Brain Markers are Linked to Age-Related Variation in Cognition

Science.gov (United States)

Hedden, Trey; Schultz, Aaron P.; Rieckmann, Anna; Mormino, Elizabeth C.; Johnson, Keith A.; Sperling, Reisa A.; Buckner, Randy L.

2016-01-01

Age-related alterations in brain structure and function have been challenging to link to cognition due to potential overlapping influences of multiple neurobiological cascades. We examined multiple brain markers associated with age-related variation in cognition. Clinically normal older humans aged 65–90 from the Harvard Aging Brain Study (N = 186) were characterized on a priori magnetic resonance imaging markers of gray matter thickness and volume, white matter hyperintensities, fractional anisotropy (FA), resting-state functional connectivity, positron emission tomography markers of glucose metabolism and amyloid burden, and cognitive factors of processing speed, executive function, and episodic memory. Partial correlation and mediation analyses estimated age-related variance in cognition shared with individual brain markers and unique to each marker. The largest relationships linked FA and striatum volume to processing speed and executive function, and hippocampal volume to episodic memory. Of the age-related variance in cognition, 70–80% was accounted for by combining all brain markers (but only ∼20% of total variance). Age had significant indirect effects on cognition via brain markers, with significant markers varying across cognitive domains. These results suggest that most age-related variation in cognition is shared among multiple brain markers, but potential specificity between some brain markers and cognitive domains motivates additional study of age-related markers of neural health. PMID:25316342

Relativistic three-particle dynamical equations: I. Theoretical development

International Nuclear Information System (INIS)

Adhikari, S.K.; Tomio, L.; Frederico, T.

1993-11-01

Starting from the two-particle Bethe-Salpeter equation in the ladder approximation and integrating over the time component of momentum, three dimensional scattering integral equations satisfying constrains of relativistic unitarity and covariance are rederived. These equations were first derived by Weinberg and by Blankenbecler and Sugar. These two-particle equations are shown to be related by a transformation of variables. Hence it is shown to perform and relate dynamical calculation using these two equations. Similarly, starting from the Bethe-Salpeter-Faddeev equation for the three-particle system and integrating over the time component of momentum, several three dimensional three-particle scattering equations satisfying constraints of relativistic unitary and covariance are derived. Two of these three-particle equations are related by a transformation of variables as in the two-particle case. The three-particle equations obtained are very practical and suitable for performing relativistic scattering calculations. (author)

Mobility decline in old age

DEFF Research Database (Denmark)

Nilsson, C.J.; Siersma, V.; Mänty, Minna Regina

2014-01-01

BACKGROUND: Mobility-related fatigue and low socioeconomic position predicts mobility limitations and disability in old age, but the interplay between these two factors is unknown. To evaluate whether mobility-related fatigue is a stronger risk factor for mobility limitations in certain...... socioeconomic groups, the aim of this study was to examine the combined effect of mobility-related fatigue and socioeconomic position on mobility limitations in a prospective study among older Danish men and women. METHODS: Multivariate linear regression models with combined exposure variables using generalised...... estimating equations were performed using four waves of data on 2874 individuals without mobility limitations at baseline from The Danish Intervention Study on Preventive Home Visits. RESULTS: Low socioeconomic position and mobility-related fatigue are risk factors for mobility limitations in old age...

[Aged woman's vulnerability related to AIDS].

Science.gov (United States)

Silva, Carla Marins; Lopes, Fernanda Maria do Valle Martins; Vargens, Octavio Muniz da Costa

2010-09-01

This article is a systhematic literature review including the period from 1994 to 2009, whose objective was to discuss the aged woman's vulnerability in relation to Acquired Imunodeficiency Syndrome (Aids). The search for scientific texts was accomplished in the following databases: Biblioteca Virtual em Saúde, Scientific Eletronic Library Online (SciELO), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) and Medical Literature Analysis and Retrieval System Online (MEDLINE). The descriptors used were vulnerability, woman and Aids. Eighteen texts were analyzed, including articles in scientific journals, thesis and dissertations. As a conclusion, it was noted that aged women and vulnerability to Aids are directly related, through gender characteristics including submission and that were built historical and socially. We consider as fundamental the development of studies which may generate publications accessible to women, in order to help them see themselves as persons vulnerable to Aids contagion just for being women.

Age-Related Imbalance Is Associated With Slower Walking Speed: An Analysis From the National Health and Nutrition Examination Survey.

Science.gov (United States)

Xie, Yanjun J; Liu, Elizabeth Y; Anson, Eric R; Agrawal, Yuri

Walking speed is an important dimension of gait function and is known to decline with age. Gait function is a process of dynamic balance and motor control that relies on multiple sensory inputs (eg, visual, proprioceptive, and vestibular) and motor outputs. These sensory and motor physiologic systems also play a role in static postural control, which has been shown to decline with age. In this study, we evaluated whether imbalance that occurs as part of healthy aging is associated with slower walking speed in a nationally representative sample of older adults. We performed a cross-sectional analysis of the previously collected 1999 to 2002 National Health and Nutrition Examination Survey (NHANES) data to evaluate whether age-related imbalance is associated with slower walking speed in older adults aged 50 to 85 years (n = 2116). Balance was assessed on a pass/fail basis during a challenging postural task-condition 4 of the modified Romberg Test-and walking speed was determined using a 20-ft (6.10 m) timed walk. Multivariable linear regression was used to evaluate the association between imbalance and walking speed, adjusting for demographic and health-related covariates. A structural equation model was developed to estimate the extent to which imbalance mediates the association between age and slower walking speed. In the unadjusted regression model, inability to perform the NHANES balance task was significantly associated with 0.10 m/s slower walking speed (95% confidence interval: -0.13 to -0.07; P imbalance mediates 12.2% of the association between age and slower walking speed in older adults. In a nationally representative sample, age-related balance limitation was associated with slower walking speed. Balance impairment may lead to walking speed declines. In addition, reduced static postural control and dynamic walking speed that occur with aging may share common etiologic origins, including the decline in visual, proprioceptive, and vestibular sensory and

The relative age effect in sport: a developmental systems model.

Science.gov (United States)

Wattie, Nick; Schorer, Jörg; Baker, Joseph

2015-01-01

The policies that dictate the participation structure of many youth sport systems involve the use of a set selection date (e.g. 31 December), which invariably produces relative age differences between those within the selection year (e.g. 1 January to 31 December). Those born early in the selection year (e.g. January) are relatively older—by as much as 12 months minus 1 day—than those born later in the selection year (e.g. December). Research in the area of sport has identified a number of significant developmental effects associated with such relative age differences. However, a theoretical framework that describes the breadth and complexity of relative age effects (RAEs) in sport does not exist in the literature. This paper reviews and summarizes the existing literature on relative age in sport, and proposes a constraints-based developmental systems model for RAEs in sport.

Lipids, lipid genes, and incident age-related macular degeneration: the three continent age-related macular degeneration consortium

NARCIS (Netherlands)

Klein, Ronald; Myers, Chelsea E.; Buitendijk, Gabriëlle H. S.; Rochtchina, Elena; Gao, Xiaoyi; de Jong, Paulus T. V. M.; Sivakumaran, Theru A.; Burlutsky, George; McKean-Cowdin, Roberta; Hofman, Albert; Iyengar, Sudha K.; Lee, Kristine E.; Stricker, Bruno H.; Vingerling, Johannes R.; Mitchell, Paul; Klein, Barbara E. K.; Klaver, Caroline C. W.; Wang, Jie Jin

2014-01-01

To describe associations of serum lipid levels and lipid pathway genes to the incidence of age-related macular degeneration (AMD). Meta-analysis. setting: Three population-based cohorts. population: A total of 6950 participants from the Beaver Dam Eye Study (BDES), Blue Mountains Eye Study (BMES),

Age-related attitudes: the influence on relationships and performance at work

NARCIS (Netherlands)

Dr. Franz Josef Gellert; R. Schalk

2012-01-01

Purpose: – This paper aims to examine the influence of age and age-related attitudes on relationship factors. In addition, it seeks to assess how both factors affect care service work performance. Design/methodology/approach: – The paper explores the influence of age and age-related attitudes on the

Age-related decrements in cycling and running performance ...

African Journals Online (AJOL)

South African Journal of Sports Medicine ... This study examined age-related decrements in athletic performance during running and cycling activities. ... These findings establish a trend that there is 'accelerated' aging during running which can perhaps be attributed to the increased weight-bearing stress on the muscles ...

Age-related macular degeneration in Onitsha, Nigeria | Nwosu ...

African Journals Online (AJOL)

Objectives: To determine the incidence, pattern and ocular morbidity associated with age-related macular degeneration (AMD) at the Guinness Eye Center Onitsha Nigeria. Materials and Methods: The case files of all new patients aged 50 years and above seen between January 1997 and December 2004 were reviewed.

Age-related degradation of Westinghouse 480-volt circuit breakers

International Nuclear Information System (INIS)

Subudhi, M.; Shier, W.; MacDougall, E.

1990-07-01

An aging assessment of Westinghouse DS-series low-voltage air circuit breakers was performed as part of the Nuclear Plant Aging Research (NPAR) program. The objectives of this study are to characterize age-related degradation within the breaker assembly and to identify maintenance practices to mitigate their effect. Since this study has been promulgated by the failures of the reactor trip breakers at the McGuire Nuclear Station in July 1987, results relating to the welds in the breaker pole lever welds are also discussed. The design and operation of DS-206 and DS-416 breakers were reviewed. Failure data from various national data bases were analyzed to identify the predominant failure modes, causes, and mechanisms. Additional operating experiences from one nuclear station and two industrial breaker-service companies were obtained to develop aging trends of various subcomponents. The responses of the utilities to the NRC Bulletin 88-01, which discusses the center pole lever welds, were analyzed to assess the final resolution of failures of welds in the reactor trips. Maintenance recommendations, made by the manufacturer to mitigate age-related degradation were reviewed, and recommendations for improving the monitoring of age-related degradation are discussed. As described in Volume 2 of this NUREG, the results from a test program to assess degradation in breaker parts through mechanical cycling are also included. The testing has characterized the cracking of center-pole lever welds, identified monitoring techniques to determine aging in breakers, and provided information to augment existing maintenance programs. Recommendations to improve breaker reliability using effective maintenance, testing, and inspection programs are suggested. 13 refs., 21 figs., 8 tabs

Dietary compound score and risk of age-related macular degeneration in the Age-Related Eye Disease Study

Science.gov (United States)

Purpose: Because foods provide many nutrients, which may interact with each other to modify risk for multifactorial diseases such as age-related macular degeneration (AMD), we sought to develop a composite scoring system to summarize the combined effect of multiple dietary nutrients on AMD risk. Th...

Gender Relations and Applied Research on Aging

Science.gov (United States)

Calasanti, Toni

2010-01-01

As a concept in gerontology, gender appears as lists of traits learned through socialization when theorized at all. I argue for a framework that theorizes the intersections of relations of gender inequality with those of age. This framework holds that men and women gain resources and bear responsibilities, in relation to one another, by virtue of…

Multivalued stochastic delay differential equations and related ...

African Journals Online (AJOL)

We study the existence and uniqueness of a solution for the multivalued stochastic differential equation with delay (the multivalued term is of subdifferential type):. dX(t) + aφ (X(t))dt ∍ b(t,X(t), Y(t), Z(t)) dt. ⎨ +σ (t, X (t), Y (t), Z (t)) dW (t), t ∈ (s, T). X(t) = ξ (t - s), t ∈ [s - δ, s]. Specify that in this case the coefficients at time t ...

Local Observed-Score Kernel Equating

Science.gov (United States)

Wiberg, Marie; van der Linden, Wim J.; von Davier, Alina A.

2014-01-01

Three local observed-score kernel equating methods that integrate methods from the local equating and kernel equating frameworks are proposed. The new methods were compared with their earlier counterparts with respect to such measures as bias--as defined by Lord's criterion of equity--and percent relative error. The local kernel item response…

Generalization of Einstein's gravitational field equations

Science.gov (United States)

Moulin, Frédéric

2017-12-01

The Riemann tensor is the cornerstone of general relativity, but as is well known it does not appear explicitly in Einstein's equation of gravitation. This suggests that the latter may not be the most general equation. We propose here for the first time, following a rigorous mathematical treatment based on the variational principle, that there exists a generalized 4-index gravitational field equation containing the Riemann curvature tensor linearly, and thus the Weyl tensor as well. We show that this equation, written in n dimensions, contains the energy-momentum tensor for matter and that of the gravitational field itself. This new 4-index equation remains completely within the framework of general relativity and emerges as a natural generalization of the familiar 2-index Einstein equation. Due to the presence of the Weyl tensor, we show that this equation contains much more information, which fully justifies the use of a fourth-order theory.

Audiovisual Temporal Perception in Aging: The Role of Multisensory Integration and Age-Related Sensory Loss.

Science.gov (United States)

Brooks, Cassandra J; Chan, Yu Man; Anderson, Andrew J; McKendrick, Allison M

2018-01-01

Within each sensory modality, age-related deficits in temporal perception contribute to the difficulties older adults experience when performing everyday tasks. Since perceptual experience is inherently multisensory, older adults also face the added challenge of appropriately integrating or segregating the auditory and visual cues present in our dynamic environment into coherent representations of distinct objects. As such, many studies have investigated how older adults perform when integrating temporal information across audition and vision. This review covers both direct judgments about temporal information (the sound-induced flash illusion, temporal order, perceived synchrony, and temporal rate discrimination) and judgments regarding stimuli containing temporal information (the audiovisual bounce effect and speech perception). Although an age-related increase in integration has been demonstrated on a variety of tasks, research specifically investigating the ability of older adults to integrate temporal auditory and visual cues has produced disparate results. In this short review, we explore what factors could underlie these divergent findings. We conclude that both task-specific differences and age-related sensory loss play a role in the reported disparity in age-related effects on the integration of auditory and visual temporal information.

Audiovisual Temporal Perception in Aging: The Role of Multisensory Integration and Age-Related Sensory Loss

Science.gov (United States)

Brooks, Cassandra J.; Chan, Yu Man; Anderson, Andrew J.; McKendrick, Allison M.

2018-01-01

Within each sensory modality, age-related deficits in temporal perception contribute to the difficulties older adults experience when performing everyday tasks. Since perceptual experience is inherently multisensory, older adults also face the added challenge of appropriately integrating or segregating the auditory and visual cues present in our dynamic environment into coherent representations of distinct objects. As such, many studies have investigated how older adults perform when integrating temporal information across audition and vision. This review covers both direct judgments about temporal information (the sound-induced flash illusion, temporal order, perceived synchrony, and temporal rate discrimination) and judgments regarding stimuli containing temporal information (the audiovisual bounce effect and speech perception). Although an age-related increase in integration has been demonstrated on a variety of tasks, research specifically investigating the ability of older adults to integrate temporal auditory and visual cues has produced disparate results. In this short review, we explore what factors could underlie these divergent findings. We conclude that both task-specific differences and age-related sensory loss play a role in the reported disparity in age-related effects on the integration of auditory and visual temporal information. PMID:29867415

Age-related changes of monoaminooxidases in rat cerebellar cortex

Directory of Open Access Journals (Sweden)

FM Tranquilli Leali

2009-06-01

Full Text Available Age-related changes of the monoaminoxidases, evaluated by enzymatic staining, quantitative analysis of images, biochemical assay and statistical analysis of data were studied in cerebellar cortex of young (3-month-old and aged (26- month-old male Sprague-Dawley rats. The enzymatic staining shows the presence of monoamino-oxidases within the molecular and granular layers as well as within the Purkinje neurons of the cerebellum of young and aged animals. In molecular layer, and in Purkinje neurons the levels of monoaminooxidases were strongly increased in old rats. The granular layer showed, on the contrary, an age-dependent loss of enzymatic staining. These morphological findings were confirmed by biochemical results. The possibility that age-related changes in monoaminooxidase levels may be due to impaired energy production mechanisms and/or represent the consequence of reduced energetic needs is discussed.

Age-related effects in the neocortical organization of chimpanzees

DEFF Research Database (Denmark)

Autrey, Michelle M; Reamer, Lisa A; Mareno, Mary Catherine

2014-01-01

chimpanzees. We used the BrainVisa software to measure total brain volume, gray and white matter volumes, gray matter thickness, and gyrification index in a cross-sectional sample of 219 captive chimpanzees (8-53 years old), with 38 subjects being 40 or more years of age. Mean depth and cortical fold opening...... of 11 major sulci of the chimpanzee brains were also measured. We found that chimpanzees showed increased gyrification with age and a cubic relationship between age and white matter volume. For the association between age and sulcus depth and width, the results were mostly non......Among primates, humans exhibit the most profound degree of age-related brain volumetric decline in particular regions, such as the hippocampus and the frontal lobe. Recent studies have shown that our closest living relatives, the chimpanzees, experience little to no volumetric decline in gray...

Lorentz-force equations as Heisenberg equations for a quantum system in the euclidean space

International Nuclear Information System (INIS)

Rodriguez D, R.

2007-01-01

In an earlier work, the dynamic equations for a relativistic charged particle under the action of electromagnetic fields were formulated by R. Yamaleev in terms of external, as well as internal momenta. Evolution equations for external momenta, the Lorentz-force equations, were derived from the evolution equations for internal momenta. The mapping between the observables of external and internal momenta are related by Viete formulae for a quadratic polynomial, the characteristic polynomial of the relativistic dynamics. In this paper we show that the system of dynamic equations, can be cast into the Heisenberg scheme for a four-dimensional quantum system. Within this scheme the equations in terms of internal momenta play the role of evolution equations for a state vector, whereas the external momenta obey the Heisenberg equation for an operator evolution. The solutions of the Lorentz-force equation for the motion inside constant electromagnetic fields are presented via pentagonometric functions. (Author)

Didactic derivation of the special theory of relativity from the Klein–Gordon equation

International Nuclear Information System (INIS)

Arodź, H

2014-01-01

We present a didactic derivation of the special theory of relativity in which Lorentz transformations are ‘discovered’ as symmetry transformations of the Klein–Gordon equation. The interpretation of Lorentz boosts as transformations to moving inertial reference frames is not assumed at the start, but it naturally appears at a later stage. The relative velocity v of two inertial reference frames is defined in terms of the elements of the pertinent Lorentz matrix, and the bound |v|< c is presented as a simple theorem that follows from the structure of the Lorentz group. The polar decomposition of Lorentz matrices is used to explain noncommutativity and nonassociativity of the relativistic composition (‘addition’) of velocities. (paper)

The Influence of Age-Related Cues on Health and Longevity.

Science.gov (United States)

Hsu, Laura M; Chung, Jaewoo; Langer, Ellen J

2010-11-01

Environmental cues that signal aging may directly and indirectly prime diminished capacity. Similarly, the absence of these cues may prime improved health. The authors investigated the effects of age cues on health and longevity in five very different settings. The findings include the following: First, women who think they look younger after having their hair colored/cut show a decrease in blood pressure and appear younger in photographs (in which their hair is cropped out) to independent raters. Second, clothing is an age-related cue. Uniforms eliminate these age-related cues: Those who wear work uniforms have lower morbidity than do those who earn the same amount of money and do not wear work uniforms. Third, baldness cues old age. Men who bald prematurely see an older self and therefore age faster: Prematurely bald men have an excess risk of getting prostate cancer and coronary heart disease than do men who do not prematurely bald. Fourth, women who bear children later in life are surrounded by younger age-related cues: Older mothers have a longer life expectancy than do women who bear children earlier in life. Last, large spousal age differences result in age-incongruent cues: Younger spouses live shorter lives and older spouses live longer lives than do controls. © The Author(s) 2010.

Rare event simulation for stochastic fixed point equations related to the smoothing transform

DEFF Research Database (Denmark)

Collamore, Jeffrey F.; Vidyashankar, Anand N.; Xu, Jie

2013-01-01

In several applications arising in computer science, cascade theory, and other applied areas, it is of interest to evaluate the tail probabilities of non-homogeneous stochastic fixed point equations. Recently, techniques have been developed for the related linear recursions, yielding tail estimates...... and importance sampling methods for these recursions. However, such methods do not routinely generalize to non-homogeneous recursions. Drawing on techniques from the weighted branching process literature, we present a consistent, strongly efficient importance sampling algorithm for estimating the tail...

A Kind of Nonlinear Programming Problem Based on Mixed Fuzzy Relation Equations Constraints

Science.gov (United States)

Li, Jinquan; Feng, Shuang; Mi, Honghai

In this work, a kind of nonlinear programming problem with non-differential objective function and under the constraints expressed by a system of mixed fuzzy relation equations is investigated. First, some properties of this kind of optimization problem are obtained. Then, a polynomial-time algorithm for this kind of optimization problem is proposed based on these properties. Furthermore, we show that this algorithm is optimal for the considered optimization problem in this paper. Finally, numerical examples are provided to illustrate our algorithms.

Age-related percutaneous penetration part 1: skin factors.

Science.gov (United States)

Konda, S; Meier-Davis, S R; Cayme, B; Shudo, J; Maibach, H I

2012-05-01

Changes in the skin that occur in the elderly may put them at increased risk for altered percutaneous penetration from pharmacotherapy along with potential adverse effects. Skin factors that may have a role in age-related percutaneous penetration include blood flow, pH, skin thickness, hair and pore density, and the content and structure of proteins, glycosaminoglycans (GAGs), water, and lipids. Each factor is examined as a function of increasing age along with its potential impact on percutaneous penetration. Additionally, topical drugs that successfully overcome the barrier function of the skin can still fall victim to cutaneous metabolism, thereby producing metabolites that may have increased or decreased activity. This overview discusses the current data and highlights the importance of further studies to evaluate the impact of skin factors in age-related percutaneous penetration.

Age-related changes in the retinal pigment epithelium (RPE.

Directory of Open Access Journals (Sweden)

Xiaorong Gu

Full Text Available Age-related changes in the retina are often accompanied by visual impairment but their mechanistic details remain poorly understood.Proteomic studies were pursued toward a better molecular understanding of retinal pigment epithelium (RPE aging mechanisms. RPE cells were isolated from young adults (3-4 month-old and old (24-25 month-old F344BN rats, and separated into subcellular fractions containing apical microvilli (MV and RPE cell bodies (CB lacking their apical microvilli. Proteins were extracted in detergent, separated by SDS-PAGE, digested in situ with trypsin and analyzed by LC MS/MS. Select proteins detected in young and old rat RPE were further studied using immunofluorescence and Western blot analysis.A total of 356 proteins were identified in RPE MV from young and 378 in RPE MV from old rats, 48% of which were common to each age group. A total of 897 proteins were identified in RPE CB from young rats and 675 in old CB, 56% of which were common to each age group. Several of the identified proteins, including proteins involved in response to oxidative stress, displayed both quantitative and qualitative changes in overall abundance during RPE aging. Numerous proteins were identified for the first time in the RPE. One such protein, collectrin, was localized to the apical membrane of apical brush border of proximal tubules where it likely regulates several amino acid transporters. Elsewhere, collectrin is involved in pancreatic β cell proliferation and insulin secretion. In the RPE, collectrin expression was significantly modulated during RPE aging. Another age-regulated, newly described protein was DJ-1, a protein extensively studied in brain where oxidative stress-related functions have been described.The data presented here reveals specific changes in the RPE during aging, providing the first protein database of RPE aging, which will facilitate future studies of age-related retinal diseases.

Work-related injuries: injury characteristics, survival, and age effect.

Science.gov (United States)

Konstantinidis, Agathoklis; Talving, Peep; Kobayashi, Leslie; Barmparas, Galinos; Plurad, David; Lam, Lydia; Inaba, Kenji; Demetriades, Demetrios

2011-06-01

Work-related injuries impose a significant burden on society. The goal of this study was to delineate the epidemiology and the effect of age on type and mortality after occupational injuries. Patients 16 years of age or older sustaining work-related injuries were identified from the National Trauma Databank 12.0. The study population was stratified into four age groups: 16 to 35, 36 to 55, 56 to 65, and older than 65 years old. The demographic characteristics, type of injury, mechanism of injury, setting of injury, use of alcohol or other illicit drugs, and mortality were analyzed and related to age strata. Overall 67,658 patients were identified. There were 27,125 (40.1%) patients in the age group 16 to 35 years, 30,090 (44.5%) in the group 36 to 55 years, 6,618 (9.8%) in the group 56 to 65 years, and 3,825 (5.7%) older than 65 years. The injury severity increased significantly with age. Elderly patients were significantly more likely to sustain intracranial hemorrhages, spinal, and other skeletal injuries. The overall mortality was 2.9 per cent (1938) with the latter increasing significantly in a stepwise fashion with progressing age, becoming sixfold higher in patients older than 65 years (OR, 6.18; 95% CI, 4.78 to 7.80; P < 0.001). Our examination illustrates the associations between occupational injury and significant mortality that warrant intervention for mortality reduction. There is a stepwise-adjusted increase in mortality with progressing age.

Age-Related Changes in Electroencephalographic Signal Complexity

Science.gov (United States)

Zappasodi, Filippo; Marzetti, Laura; Olejarczyk, Elzbieta; Tecchio, Franca; Pizzella, Vittorio

2015-01-01

The study of active and healthy aging is a primary focus for social and neuroscientific communities. Here, we move a step forward in assessing electrophysiological neuronal activity changes in the brain with healthy aging. To this end, electroencephalographic (EEG) resting state activity was acquired in 40 healthy subjects (age 16–85). We evaluated Fractal Dimension (FD) according to the Higuchi algorithm, a measure which quantifies the presence of statistical similarity at different scales in temporal fluctuations of EEG signals. Our results showed that FD increases from age twenty to age fifty and then decreases. The curve that best fits the changes in FD values across age over the whole sample is a parabola, with the vertex located around age fifty. Moreover, FD changes are site specific, with interhemispheric FD asymmetry being pronounced in elderly individuals in the frontal and central regions. The present results indicate that fractal dimension well describes the modulations of brain activity with age. Since fractal dimension has been proposed to be related to the complexity of the signal dynamics, our data demonstrate that the complexity of neuronal electric activity changes across the life span of an individual, with a steady increase during young adulthood and a decrease in the elderly population. PMID:26536036

Comprehensive Analysis of Large Sets of Age-Related Physiological Indicators Reveals Rapid Aging around the Age of 55 Years.

Science.gov (United States)

Lixie, Erin; Edgeworth, Jameson; Shamir, Lior

2015-01-01

While many studies show a correlation between chronological age and physiological indicators, the nature of this correlation is not fully understood. To perform a comprehensive analysis of the correlation between chronological age and age-related physiological indicators. Physiological aging scores were deduced using principal component analysis from a large dataset of 1,227 variables measured in a cohort of 4,796 human subjects, and the correlation between the physiological aging scores and chronological age was assessed. Physiological age does not progress linearly or exponentially with chronological age: a more rapid physiological change is observed around the age of 55 years, followed by a mild decline until around the age of 70 years. These findings provide evidence that the progression of physiological age is not linear with that of chronological age, and that periods of mild change in physiological age are separated by periods of more rapid aging. © 2015 S. Karger AG, Basel.

Deriving the equations of motion of porous isotropic media

International Nuclear Information System (INIS)

Pride, S.R.; Gangi, A.F.; Morgan, F.D.

1992-01-01

The equations of motion and stress/strain relations for the linear dynamics of a two-phase, fluid/solid, isotropic, porous material have been derived by a direct volume averaging of the equations of motion and stress-strain relations known to apply in each phase. The equations thus obtained are shown to be consistent with Biot's equations of motion and stress/strain relations; however, the effective fluid density in the equation of relative flow has an unambiguous definition in terms of the tractions acting on the pore walls. The stress/strain relations of the theory correspond to 'quasistatic' stressing (i.e., inertial effects are ignored). It is demonstrated that using such quasistatic stress/strain relations in the equations of motion is justified whenever the wavelengths are greater than a length characteristic of the averaging volume size. 37 refs., 2 figs

Formal Derivation of Lotka-Volterra-Haken Amplitude Equations of Task-Related Brain Activity in Multiple, Consecutively Performed Tasks

Science.gov (United States)

Frank, T. D.

The Lotka-Volterra-Haken equations have been frequently used in ecology and pattern formation. Recently, the equations have been proposed by several research groups as amplitude equations for task-related patterns of brain activity. In this theoretical study, the focus is on the circular causality aspect of pattern formation systems as formulated within the framework of synergetics. Accordingly, the stable modes of a pattern formation system inhibit the unstable modes, whereas the unstable modes excite the stable modes. Using this circular causality principle it is shown that under certain conditions the Lotka-Volterra-Haken amplitude equations can be derived from a general model of brain activity akin to the Wilson-Cowan model. The model captures the amplitude dynamics for brain activity patterns in experiments involving several consecutively performed multiple-choice tasks. This is explicitly demonstrated for two-choice tasks involving grasping and walking. A comment on the relevance of the theoretical framework for clinical psychology and schizophrenia is given as well.

Age-Related Reversals in Neural Recruitment across Memory Retrieval Phases.

Science.gov (United States)

Ford, Jaclyn H; Kensinger, Elizabeth A

2017-05-17

Over the last several decades, neuroimaging research has identified age-related neural changes that occur during cognitive tasks. These changes are used to help researchers identify functional changes that contribute to age-related impairments in cognitive performance. One commonly reported example of such a change is an age-related decrease in the recruitment of posterior sensory regions coupled with an increased recruitment of prefrontal regions across multiple cognitive tasks. This shift is often described as a compensatory recruitment of prefrontal regions due to age-related sensory-processing deficits in posterior regions. However, age is not only associated with spatial shifts in recruitment, but also with temporal shifts, in which younger and older adults recruit the same neural region at different points in a task trial. The current study examines the possible contribution of temporal modifications in the often-reported posterior-anterior shift. Participants, ages 19-85, took part in a memory retrieval task with a protracted retrieval trial consisting of an initial memory search phase and a subsequent detail elaboration phase. Age-related neural patterns during search replicated prior reports of age-related decreases in posterior recruitment and increases in prefrontal recruitment. However, during the later elaboration phase, the same posterior regions were associated with age-related increases in activation. Further, ROI and functional connectivity results suggest that these posterior regions function similarly during search and elaboration. These results suggest that the often-reported posterior-anterior shift may not reflect the inability of older adults to engage in sensory processing, but rather a change in when they recruit this processing. SIGNIFICANCE STATEMENT The current study provides evidence that the often-reported posterior-anterior shift in aging may not reflect a global sensory-processing deficit, as has often been reported, but rather a

Age-related changes in the testes and prostate of the Beagle dog

International Nuclear Information System (INIS)

Lowseth, L.A.; Gerlach, R.F.; Gillett, N.A.; Muggenburg, B.A.

1988-01-01

Age-related changes in the histologic morphology of the Beagle dog prostate and testes must be separated from those changes that may result from the testing of experimental compounds. The prostate and testes of healthy age-matched Beagle dogs 3 to 14 yr of age were obtained. Serum to evaluate testosterone levels was also obtained from each dog at the time of euthanasia. Tissue sections from the prostate and testes were examined by light microscopy for both qualitative and quantitative morphologic assessment. A statistically significant increase in prostatic weight with increased age was noted. Significant morphometric findings in the prostate included a decrease in the relative percent of epithelial cells and an increase in the relative lumen size of glandular acini with increased age. The absolute volume of prostate interstitial tissue and inflammation showed a statistically significant increase with age. Stereological analysis of the testes showed a decrease in the relative percent epithelium with increasing age. No distinct age-related trend could be detected in serum testosterone levels. Serum testosterone levels did not correlate with the morphologic age-related changes observed in the testes or prostate. (author)

Aging of nuclear safety related concrete structures

International Nuclear Information System (INIS)

Cerny, R.; Vydra, V.; Toman, J.; Vodak, F.

1994-01-01

An analysis of aging processes in nuclear-safety-related concrete structures (NSRCS) is presented. The major environmental stressor and aging factors affecting the performance of NSRCS are summarized, as are drying and plastic shrinkage, expansion of water during the freeze-thaw cycle, water passing through cracks dissolving or leaching the soluble calcium hydroxide, attack of acid rain and ground water, chemical reactions between particular aggregates and the alkaline solution within cement paste, reaction of calcium hydroxide in cement paste hydration products with atmospheric carbon dioxide, and physical radiation effects of neutrons and gamma radiation. The current methods for aging management in NSRCS are analyzed and evaluated. A new treatment is presented for the monitoring, evaluation and prediction of aging processes, consisting in a combination of theoretical methods, laboratory experiments, in-situ measurements and numerical simulations. 24 refs

Research on Relative Age in Hungarian Swimming

Directory of Open Access Journals (Sweden)

Nagy Nikoletta

2015-12-01

Full Text Available In 2017, the 19th World Swimming Championship will be organized in Hungary. Up to now, many people have already been working with swimmers to achieve good results. However, in the next period they must work even harder to ensure that the national swimmers of a country as small as Hungary can achieve the outstanding results of their predecessors. Since high-level competitions in swimming have become more intense, innovations including scientific studies are needed during preparation for the event. The purpose of this paper is to present the major results of an independent study carried out by the authors about the relative age of the best Hungarian swimmers with the aim of contributing to their preparation. The research population consisted of selected age groups of swimmers registered by the Hungarian Swimming Association (N=400. The method for data collection was an analysis of documents. To evaluate the data, the Chi-square and Kruskal-Wallis tests were used. The results are presented according to the period of the competitor’s date of birth, gender, and age group. The results confirm only partly the hypothesis that people born in the first quarters of the year play a dominant role in Hungarian national swimming teams. In the conclusion, the authors recommend further research on relative age in swimming and in other sports.

Insufficient DNA methylation affects healthy aging and promotes age-related health problems.

Science.gov (United States)

Liu, Liang; van Groen, Thomas; Kadish, Inga; Li, Yuanyuan; Wang, Deli; James, Smitha R; Karpf, Adam R; Tollefsbol, Trygve O

2011-08-01

DNA methylation plays an integral role in development and aging through epigenetic regulation of genome function. DNA methyltransferase 1 (Dnmt1) is the most prevalent DNA methyltransferase that maintains genomic methylation stability. To further elucidate the function of Dnmt1 in aging and age-related diseases, we exploited the Dnmt1+/- mouse model to investigate how Dnmt1 haploinsufficiency impacts the aging process by assessing the changes of several major aging phenotypes. We confirmed that Dnmt1 haploinsufficiency indeed decreases DNA methylation as a result of reduced Dnmt1 expression. To assess the effect of Dnmt1 haploinsufficiency on general body composition, we performed dual-energy X-ray absorptiometry analysis and showed that reduced Dnmt1 activity decreased bone mineral density and body weight, but with no significant impact on mortality or body fat content. Using behavioral tests, we demonstrated that Dnmt1 haploinsufficiency impairs learning and memory functions in an age-dependent manner. Taken together, our findings point to the interesting likelihood that reduced genomic methylation activity adversely affects the healthy aging process without altering survival and mortality. Our studies demonstrated that cognitive functions of the central nervous system are modulated by Dnmt1 activity and genomic methylation, highlighting the significance of the original epigenetic hypothesis underlying memory coding and function.

Parental age in relation to severity of clefting

DEFF Research Database (Denmark)

Hermann, Nuno Vibe; Darvann, Tron Andre; Kreiborg, Sven

2016-01-01

Lip and/or Palate (IC). Wilcoxon Rank-Sum test (5% significance level) was applied in order to test for group differences. Standard logistic regression was used in order to estimate the risk of developing CC relative to IC. Results. In the group with CC mean paternal age was 29.5+/-4.5 (1SD) years...... parental ages in the group with IC did not differ from normative population values during the same time period. Logistic regression showed for paternal age OR=1.1[1.04,1.16](Wald confidence limits); for maternal age 1.08[1.01,1.15]. Conclusions. The hypothesis was rejected. Parental age was significantly...... of cleft individuals, as well as to compare parental age in the cleft population with normative values of parental age. It was hypothesized that there was no difference in parental age between the cleft groups with incomplete and complete clefts, respectively. Methods/Descriptions. The consecutive non...

Fundamental equations for two-phase flow. Part 1: general conservation equations. Part 2: complement and remarks; Equations fondamentales des ecoulements diphasiques. Premiere partie: equations generales de conservation. Deuxieme partie: complements et remarques

Energy Technology Data Exchange (ETDEWEB)

Delhaye, J M [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1968-12-01

This report deals with the general equations of mass conservation, of momentum conservation, and energy conservation in the case of a two-phase flow. These equations are presented in several forms starting from integral equations which are assumed initially a priori. 1. Equations with local instantaneous variables, and interfacial conditions; 2. Equations with mean instantaneous variables in a cross-section, and practical applications: these equations include an important experimental value which is the ratio of the cross-section of passage of one phase to the total cross-section of a flow-tube. 3. Equations with a local statistical mean, and equations averaged over a period of time: A more advanced attempt to relate theory and experiment consists in taking the statistical averages of local equations. Equations are then obtained involving variables which are averaged over a period of time with the help of an ergodic assumption. 4. Combination of statistical averages and averages over a cross-section: in this study are considered the local variables averaged statistically, then averaged over the cross-section, and also the variables averaged over the section and then averaged statistically. 5. General equations concerning emulsions: In this case a phase exists in a locally very finely divided form. This peculiarity makes it possible to define a volume concentration, and to draw up equations which have numerous applications. - Certain points arising in the first part of this report concerning general mass conservation equations for two-phase flow have been completed and clarified. The terms corresponding to the interfacial tension have been introduced into the general equations. The interfacial conditions have thus been generalized. A supplementary step has still to be carried out: it has, in effect, been impossible to take the interfacial tension into account in the case of emulsions. It was then appeared interesting to compare this large group of fundamental

Fundamental equations for two-phase flow. Part 1: general conservation equations. Part 2: complement and remarks; Equations fondamentales des ecoulements diphasiques. Premiere partie: equations generales de conservation. Deuxieme partie: complements et remarques

Energy Technology Data Exchange (ETDEWEB)

Delhaye, J.M. [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1968-12-01

This report deals with the general equations of mass conservation, of momentum conservation, and energy conservation in the case of a two-phase flow. These equations are presented in several forms starting from integral equations which are assumed initially a priori. 1. Equations with local instantaneous variables, and interfacial conditions; 2. Equations with mean instantaneous variables in a cross-section, and practical applications: these equations include an important experimental value which is the ratio of the cross-section of passage of one phase to the total cross-section of a flow-tube. 3. Equations with a local statistical mean, and equations averaged over a period of time: A more advanced attempt to relate theory and experiment consists in taking the statistical averages of local equations. Equations are then obtained involving variables which are averaged over a period of time with the help of an ergodic assumption. 4. Combination of statistical averages and averages over a cross-section: in this study are considered the local variables averaged statistically, then averaged over the cross-section, and also the variables averaged over the section and then averaged statistically. 5. General equations concerning emulsions: In this case a phase exists in a locally very finely divided form. This peculiarity makes it possible to define a volume concentration, and to draw up equations which have numerous applications. - Certain points arising in the first part of this report concerning general mass conservation equations for two-phase flow have been completed and clarified. The terms corresponding to the interfacial tension have been introduced into the general equations. The interfacial conditions have thus been generalized. A supplementary step has still to be carried out: it has, in effect, been impossible to take the interfacial tension into account in the case of emulsions. It was then appeared interesting to compare this large group of fundamental

Degenerate nonlinear diffusion equations

CERN Document Server

Favini, Angelo

2012-01-01

The aim of these notes is to include in a uniform presentation style several topics related to the theory of degenerate nonlinear diffusion equations, treated in the mathematical framework of evolution equations with multivalued m-accretive operators in Hilbert spaces. The problems concern nonlinear parabolic equations involving two cases of degeneracy. More precisely, one case is due to the vanishing of the time derivative coefficient and the other is provided by the vanishing of the diffusion coefficient on subsets of positive measure of the domain. From the mathematical point of view the results presented in these notes can be considered as general results in the theory of degenerate nonlinear diffusion equations. However, this work does not seek to present an exhaustive study of degenerate diffusion equations, but rather to emphasize some rigorous and efficient techniques for approaching various problems involving degenerate nonlinear diffusion equations, such as well-posedness, periodic solutions, asympt...

Sports related injuries in Scottish adolescents aged 11-15

OpenAIRE

Williams, J. M.; Wright, P.; Currie, C. E.; Beattie, T. F.

1998-01-01

OBJECTIVES: To measure the age and sex distribution of self reported sports and leisure injuries in a 12 month retrospective recall period among a representative national sample of Scottish adolescents, and to examine the characteristics (gender, age, handedness, and level of sports participation) of sports related injuries in relation to injuries sustained during other activities. DESIGN/SETTING: Self completion questionnaire survey administered in schools during April- June 1994. SUBJ...

On the balance equations for a dilute binary mixture in special relativity

International Nuclear Information System (INIS)

Moratto, Valdemar; Garcia-Perciante, A. L.; Garcia-Colin, L. S.

2010-01-01

In this work we study the properties of a relativistic mixture of two non-reacting species in thermal local equilibrium. We use the full Boltzmann equation (BE) to find the general balance equations. Following conventional ideas in kinetic theory, we use the concept of chaotic velocity. This is a novel approach to the problem. The resulting equations will be the starting point of the calculation exhibiting the correct thermodynamic forces and the corresponding fluxes; these results will be published elsewhere.

Sleep-related erections throughout the ages.

Science.gov (United States)

van Driel, Mels F

2014-07-01

The occurrence of sleep-related erections (SREs) has been known since antiquity. To highlight historical, theological, and sexual medicine-related aspects of SREs throughout the ages. Review of old medical books on male sexual functioning and review of scientific medical and theological articles on SREs from about 1900 on. The cyclic character of SREs was first noted by German researchers in the forties of the 20th century. However, already before the beginning of the Christian era, one knew that men had erections and ejaculations during sleep. In the Middle Ages, SREs were generally considered to be rebellious manifestations of the male body, while it seemed to disobey its owner and showed up its perverted and sinful side. From the fifteenth to the end of the 17th century, severe erectile dysfunction (ED) was ground for divorce. The ecclesiastical court records show that if necessary, the members of the jury sat at the defendant's bedside at night to be able to judge any SREs occurring. Since the 17th century, SREs were considered to be part of masturbation, which could cause many ailments and diseases. Psychoanalyst Stekel acknowledged in 1920 that a morning erection, the last SRE, is a naturally occurring phenomenon in healthy men from infancy to old age. Today, some scientists assume that SREs protect the integrity of the penile cavernous bodies. Throughout the ages, philosophers, theologians, physicians, members of ecclesial law courts, psychoanalysts, psychiatrists, sexologists, physiologists, and urologists have shown interest in SREs. Obviously, the observations and testing of SREs have a long history, from antiquity to modern sleep labs, in men and in women, in newborns and old adults, by penis rings with sharp spikes to fancy strain gauge devices. Despite all these efforts, the mechanisms leading to SREs and its function are however not yet completely understood. © 2014 International Society for Sexual Medicine.

The time dependent Schrodinger equation revisited I: quantum field and classical Hamilton-Jacobi routes to Schrodinger's wave equation

International Nuclear Information System (INIS)

Scully, M O

2008-01-01

The time dependent Schrodinger equation is frequently 'derived' by postulating the energy E → i h-bar (∂/∂t) and momentum p-vector → ( h-bar /i)∇ operator relations. In the present paper we review the quantum field theoretic route to the Schrodinger wave equation which treats time and space as parameters, not operators. Furthermore, we recall that a classical (nonlinear) wave equation can be derived from the classical action via Hamiltonian-Jacobi theory. By requiring the wave equation to be linear we again arrive at the Schrodinger equation, without postulating operator relations. The underlying philosophy is operational: namely 'a particle is what a particle detector detects.' This leads us to a useful physical picture combining the wave (field) and particle paradigms which points the way to the time-dependent Schrodinger equation

A Divide-and-Conquer Approach for Solving Fuzzy Max-Archimedean t-Norm Relational Equations

Directory of Open Access Journals (Sweden)

Jun-Lin Lin

2014-01-01

Full Text Available A system of fuzzy relational equations with the max-Archimedean t-norm composition was considered. The relevant literature indicated that this problem can be reduced to the problem of finding all the irredundant coverings of a binary matrix. A divide-and-conquer approach is proposed to solve this problem and, subsequently, to solve the original problem. This approach was used to analyze the binary matrix and then decompose the matrix into several submatrices such that the irredundant coverings of the original matrix could be constructed using the irredundant coverings of each of these submatrices. This step was performed recursively for each of these submatrices to obtain the irredundant coverings. Finally, once all the irredundant coverings of the original matrix were found, they were easily converted into the minimal solutions of the fuzzy relational equations. Experiments on binary matrices, with the number of irredundant coverings ranging from 24 to 9680, were also performed. The results indicated that, for test matrices that could initially be partitioned into more than one submatrix, this approach reduced the execution time by more than three orders of magnitude. For the other test matrices, this approach was still useful because certain submatrices could be partitioned into more than one submatrix.

Sexual activity and aging.

Science.gov (United States)

Ni Lochlainn, Mary; Kenny, Rose Anne

2013-08-01

Sexuality is an important component of emotional and physical intimacy that men and women experience throughout their lives. Research suggesting that a high proportion of men and women remain sexually active well into later life refutes the prevailing myth that aging and sexual dysfunction are inexorably linked. Age-related physiological changes do not render a meaningful sexual relationship impossible or even necessarily difficult. Many of these physiological changes are modifiable. There are various therapeutic options available to patients to achieve maximum sexual capacity in old age. This article reviews the prevalence of sexual activity among older adults, the problems these adults encounter with sexual activity, and the role of the health care professional in addressing these problems. The physiological sex-related changes that occur as part of the normal aging process in men and women are reviewed, as well as the effect of age-related physical and psychological illness on sexual function. The attitudes and perceptions of the media and general public toward sexual activity and aging are summarized. An understanding of the sexual changes that accompany the aging process may help general practitioners and other doctors to give practical and useful advice on sexuality as well as refute the misconception that aging equates to celibacy. A thorough awareness of this aspect of older people's quality of life can raise meaningful expectations for aging patients. Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

A note on Verhulst's logistic equation and related logistic maps

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, M Ranferi; Reyes, M A [Depto de Fisica, Universidad de Guanajuato, Apdo. Postal E143, 37150 Leon, Gto. (Mexico); Rosu, H C, E-mail: hcr@ipicyt.edu.m [IPICyT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Apdo Postal 3-74 Tangamanga, 78231 San Luis PotosI (Mexico)

2010-05-21

We consider the Verhulst logistic equation and a couple of forms of the corresponding logistic maps. For the case of the logistic equation we show that using the general Riccati solution only changes the initial conditions of the equation. Next, we consider two forms of corresponding logistic maps reporting the following results. For the map x{sub n+1} = rx{sub n}(1 - x{sub n}) we propose a new way to write the solution for r = -2 which allows better precision of the iterative terms, while for the map x{sub n+1} - x{sub n} = rx{sub n}(1 - x{sub n+1}) we show that it behaves identically to the logistic equation from the standpoint of the general Riccati solution, which is also provided herein for any value of the parameter r.

New approaches and potential treatments for dry age-related macular degeneration

Directory of Open Access Journals (Sweden)

Francisco Max Damico

2012-02-01

Full Text Available Emerging treatments for dry age-related macular degeneration (AMD and geographi c atrophy focus on two strategies that target components involved in physiopathological pathways: prevention of photoreceptors and retinal pigment epithelium loss (neuroprotection induction, oxidative damage prevention, and visual cycle modification and suppression of inflammation. Neuroprotective drugs, such as ciliary neurotrophic factor, brimonidine tartrate, tandospirone, and anti-amyloid β antibodies, aim to prevent apoptosis of retinal cells. Oxidative stress and depletion of essential micronutrients are targeted by the Age-Related Eye Disease Study (AREDS formulation. Visual cycle modulators reduce the activity of the photoreceptors and retinal accumulation of toxic fluorophores and lipofuscin. Eyes with dry age-related macular degeneration present chronic inflammation and potential treatments include corticosteroid and complement inhibition. We review the current concepts and rationale of dry age-related macular degeneration treatment that will most likely include a combination of drugs targeting different pathways involved in the development and progression of age-related macular degeneration.

Age-related decline in functional connectivity of the vestibular cortical network.

Science.gov (United States)

Cyran, Carolin Anna Maria; Boegle, Rainer; Stephan, Thomas; Dieterich, Marianne; Glasauer, Stefan

2016-04-01

In the elderly, major complaints include dizziness and an increasing number of falls, possibly related to an altered processing of vestibular sensory input. In this study, we therefore investigate age-related changes induced by processing of vestibular sensory stimulation. While previous functional imaging studies of healthy aging have investigated brain function during task performance or at rest, we used galvanic vestibular stimulation during functional MRI in a task-free sensory stimulation paradigm to study the effect of healthy aging on central vestibular processing, which might only become apparent during stimulation processing. Since aging may affect signatures of brain function beyond the BOLD-signal amplitude-such as functional connectivity or temporal signal variability--we employed independent component analysis and partial least squares analysis of temporal signal variability. We tested for age-associated changes unrelated to vestibular processing, using a motor paradigm, voxel-based morphometry and diffusion tensor imaging. This allows us to control for general age-related modifications, possibly originating from vascular, atrophic or structural connectivity changes. Age-correlated decreases of functional connectivity and increases of BOLD--signal variability were associated with multisensory vestibular networks. In contrast, no age-related functional connectivity changes were detected in somatosensory networks or during the motor paradigm. The functional connectivity decrease was not due to structural changes but to a decrease in response amplitude. In synopsis, our data suggest that both the age-dependent functional connectivity decrease and the variability increase may be due to deteriorating reciprocal cortico-cortical inhibition with age and related to multimodal vestibular integration of sensory inputs.

Group foliation of finite difference equations

Science.gov (United States)

Thompson, Robert; Valiquette, Francis

2018-06-01

Using the theory of equivariant moving frames, a group foliation method for invariant finite difference equations is developed. This method is analogous to the group foliation of differential equations and uses the symmetry group of the equation to decompose the solution process into two steps, called resolving and reconstruction. Our constructions are performed algorithmically and symbolically by making use of discrete recurrence relations among joint invariants. Applications to invariant finite difference equations that approximate differential equations are given.

Manhattan equation for the operational amplifier

OpenAIRE

Mishonov, Todor M.; Danchev, Victor I.; Petkov, Emil G.; Gourev, Vassil N.; Dimitrova, Iglika M.; Varonov, Albert M.

2018-01-01

A differential equation relating the voltage at the output of an operational amplifier $U_0$ and the difference between the input voltages ($U_{+}$ and $U_{-}$) has been derived. The crossover frequency $f_0$ is a parameter in this operational amplifier master equation. The formulas derived as a consequence of this equation find applications in thousands of specifications for electronic devices but as far as we know, the equation has never been published. Actually, the master equation of oper...

Driving and Age-Related Macular Degeneration

OpenAIRE

Owsley, Cynthia; McGwin, Gerald

2008-01-01

This article reviews the research literature on driving and age-related macular degeneration, which is motivated by the link between driving and the quality of life of older adults and their increased collision rate. It addresses the risk of crashes, driving performance, driving difficulty, self-regulation, and interventions to enhance, safety, and considers directions for future research.

The effect of normal aging and age-related macular degeneration on perceptual learning.

Science.gov (United States)

Astle, Andrew T; Blighe, Alan J; Webb, Ben S; McGraw, Paul V

2015-01-01

We investigated whether perceptual learning could be used to improve peripheral word identification speed. The relationship between the magnitude of learning and age was established in normal participants to determine whether perceptual learning effects are age invariant. We then investigated whether training could lead to improvements in patients with age-related macular degeneration (AMD). Twenty-eight participants with normal vision and five participants with AMD trained on a word identification task. They were required to identify three-letter words, presented 10° from fixation. To standardize crowding across each of the letters that made up the word, words were flanked laterally by randomly chosen letters. Word identification performance was measured psychophysically using a staircase procedure. Significant improvements in peripheral word identification speed were demonstrated following training (71% ± 18%). Initial task performance was correlated with age, with older participants having poorer performance. However, older adults learned more rapidly such that, following training, they reached the same level of performance as their younger counterparts. As a function of number of trials completed, patients with AMD learned at an equivalent rate as age-matched participants with normal vision. Improvements in word identification speed were maintained at least 6 months after training. We have demonstrated that temporal aspects of word recognition can be improved in peripheral vision with training across a range of ages and these learned improvements are relatively enduring. However, training targeted at other bottlenecks to peripheral reading ability, such as visual crowding, may need to be incorporated to optimize this approach.

Age-related cerebral white matter changes on computed tomography

International Nuclear Information System (INIS)

Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

1989-01-01

Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm 2 ) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author)

Age-related cerebral white matter changes on computed tomography

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

1989-01-01

Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm/sup 2/) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author).

[Impact of thymic function in age-related immune deterioration].

Science.gov (United States)

Ferrando-Martínez, Sara; de la Fuente, Mónica; Guerrero, Juan Miguel; Leal, Manuel; Muñoz-Fernández, M Ángeles

2013-01-01

Age-related biological deterioration also includes immune system deterioration and, in consequence, a rise in the incidence and prevalence of infections and cancers, as well as low responses to vaccination strategies. Out of all immune cell subsets, T-lymphocytes seem to be involved in most of the age-related defects. Since T-lymphocytes mature during their passage through the thymus, and the thymus shows an age-related process of atrophy, thymic regression has been proposed as the triggering event of this immune deterioration in elderly people. Historically, it has been accepted that the young thymus sets the T-lymphocyte repertoire during the childhood, whereupon atrophy begins until the elderly thymus is a non-functional evolutionary trace. However, a rising body of knowledge points toward the thymus functioning during adulthood. In the elderly, higher thymic function is associated with a younger immune system, while thymic function failure is associated with all-cause mortality. Therefore, any new strategy focused on the improvement of the elderly quality of life, especially those trying to influence the immune system, should take into account, together with peripheral homeostasis, thymus function as a key element in slowing down age-related decline. Copyright © 2012 SEGG. Published by Elsevier Espana. All rights reserved.

Hypoxia-Inducible Histone Lysine Demethylases: Impact on the Aging Process and Age-Related Diseases

Science.gov (United States)

Salminen, Antero; Kaarniranta, Kai; Kauppinen, Anu

2016-01-01

Hypoxia is an environmental stress at high altitude and underground conditions but it is also present in many chronic age-related diseases, where blood flow into tissues is impaired. The oxygen-sensing system stimulates gene expression protecting tissues against hypoxic insults. Hypoxia stabilizes the expression of hypoxia-inducible transcription factor-1α (HIF-1α), which controls the expression of hundreds of survival genes related to e.g. enhanced energy metabolism and autophagy. Moreover, many stress-related signaling mechanisms, such as oxidative stress and energy metabolic disturbances, as well as the signaling cascades via ceramide, mTOR, NF-κB, and TGF-β pathways, can also induce the expression of HIF-1α protein to facilitate cell survival in normoxia. Hypoxia is linked to prominent epigenetic changes in chromatin landscape. Screening studies have indicated that the stabilization of HIF-1α increases the expression of distinct histone lysine demethylases (KDM). HIF-1α stimulates the expression of KDM3A, KDM4B, KDM4C, and KDM6B, which enhance gene transcription by demethylating H3K9 and H3K27 sites (repressive epigenetic marks). In addition, HIF-1α induces the expression of KDM2B and KDM5B, which repress transcription by demethylating H3K4me2,3 sites (activating marks). Hypoxia-inducible KDMs support locally the gene transcription induced by HIF-1α, although they can also control genome-wide chromatin landscape, especially KDMs which demethylate H3K9 and H3K27 sites. These epigenetic marks have important role in the control of heterochromatin segments and 3D folding of chromosomes, as well as the genetic loci regulating cell type commitment, proliferation, and cellular senescence, e.g. the INK4 box. A chronic stimulation of HIF-1α can provoke tissue fibrosis and cellular senescence, which both are increasingly present with aging and age-related diseases. We will review the regulation of HIF-1α-dependent induction of KDMs and clarify their role in

Antagonistic pleiotropy and mutation accumulation contribute to age-related decline in stress response.

Science.gov (United States)

Everman, Elizabeth R; Morgan, Theodore J

2018-02-01

As organisms age, the effectiveness of natural selection weakens, leading to age-related decline in fitness-related traits. The evolution of age-related changes associated with senescence is likely influenced by mutation accumulation (MA) and antagonistic pleiotropy (AP). MA predicts that age-related decline in fitness components is driven by age-specific sets of alleles, nonnegative genetic correlations within trait across age, and an increase in the coefficient of genetic variance. AP predicts that age-related decline in a trait is driven by alleles with positive effects on fitness in young individuals and negative effects in old individuals, and is expected to lead to negative genetic correlations within traits across age. We build on these predictions using an association mapping approach to investigate the change in additive effects of SNPs across age and among traits for multiple stress-response fitness-related traits, including cold stress with and without acclimation and starvation resistance. We found support for both MA and AP theories of aging in the age-related decline in stress tolerance. Our study demonstrates that the evolution of age-related decline in stress tolerance is driven by a combination of alleles that have age-specific additive effects, consistent with MA, as well as nonindependent and antagonistic genetic architectures characteristic of AP. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Gene expression changes for antioxidants pathways in the mouse cochlea: relations to age-related hearing deficits.

Directory of Open Access Journals (Sweden)

Sherif F Tadros

Full Text Available Age-related hearing loss - presbycusis - is the number one neurodegenerative disorder and top communication deficit of our aged population. Like many aging disorders of the nervous system, damage from free radicals linked to production of reactive oxygen and/or nitrogen species (ROS and RNS, respectively may play key roles in disease progression. The efficacy of the antioxidant systems, e.g., glutathione and thioredoxin, is an important factor in pathophysiology of the aging nervous system. In this investigation, relations between the expression of antioxidant-related genes in the auditory portion of the inner ear - cochlea, and age-related hearing loss was explored for CBA/CaJ mice. Forty mice were classified into four groups according to age and degree of hearing loss. Cochlear mRNA samples were collected and cDNA generated. Using Affymetrix® GeneChip, the expressions of 56 antioxidant-related gene probes were analyzed to estimate the differences in gene expression between the four subject groups. The expression of Glutathione peroxidase 6, Gpx6; Thioredoxin reductase 1, Txnrd1; Isocitrate dehydrogenase 1, Idh1; and Heat shock protein 1, Hspb1; were significantly different, or showed large fold-change differences between subject groups. The Gpx6, Txnrd1 and Hspb1 gene expression changes were validated using qPCR. The Gpx6 gene was upregulated while the Txnrd1 gene was downregulated with age/hearing loss. The Hspb1 gene was found to be downregulated in middle-aged animals as well as those with mild presbycusis, whereas it was upregulated in those with severe presbycusis. These results facilitate development of future interventions to predict, prevent or slow down the progression of presbycusis.

Age-Related Differences in Quality of Standing Balance Using a Composite Score

NARCIS (Netherlands)

Pasma, J.H.; Bijlsma, A.Y.; van der Bij, M.D.W.; Arendzen, J.H.; Meskers, C.G.M.; Maier, A.B.

2014-01-01

Background: Age-related differences in standing balance are not detected by testing the ability to maintain balance. Quality of standing balance might be more sensitive to detect age-related differences. Objective: To study age-related differences in quality of standing balance, center of pressure

The changes of cerebral morphology related to aging in Taiwanese population.

Directory of Open Access Journals (Sweden)

Hsiao-Lan Sharon Wang

Full Text Available A cross-sectional study with the 3-dimensional (3D MRI reconstruction technique was conducted to investigate cerebral complexity changes related to age differences in native Taiwanese population. In our sample of 85 participants aged between 25 and 81, age was associated with gradual ventricular expansion. A nonlinear quadratic relationship between white matter volume and age was found overall in the brain. Widespread age-related reduction in white matter was detected from late adulthood onwards. However, no significant age-related changes in the cortex and whole brain volume were determined throughout adulthood. These findings provided information in describing brain structural complexity, which might in the future serve as an objective diagnostic index or as a predictive parameter for neurological diseases. Our method then may be used for cross-cultural longitudinal studies to evaluate the effect of disease, environment and aging on the brain.

Perceptual and social attributes underlining age-related preferences for faces

Directory of Open Access Journals (Sweden)

Hanni SM Kiiski

2016-08-01

Full Text Available Although aesthetic preferences are known to be important in person perception and can play a significant role in everyday social decisions, the effect of the age of the observer on aesthetic preferences for faces of different ages has not yet been fully investigated. In the present study we investigated whether aesthetic preferences change with ageing, with an age-related bias in favouring faces from one’s own age group. In addition, we examined the role of age on both the perceptual qualities and the social attributes of faces that may influence these aesthetic judgements. Both younger and older adult observers provided ratings to images of younger, middle-aged and older unfamiliar faces. As well as attractiveness, the rating dimensions included other perceptual (distinctiveness, familiarity and social (competence, trustworthiness and dominance factors. The results suggested a consistent aesthetic preference for youthful faces across all ages of the observers but, surprisingly, no evidence for an age-related bias in attractiveness ratings. Older adults tended to provide higher ratings of attractiveness, competence and trustworthiness to the unfamiliar faces, consistent with the positivity effect previously reported. We also tested whether perceptual factors such as face familiarity or distinctiveness affected aesthetic ratings. Only ratings of familiarity, but not distinctiveness, were positively associated with the attractiveness of the faces. Moreover, ratings of familiarity decreased with increasing age of the face. With regard to the social characteristics of the faces, we found that the age of the face negatively correlated with ratings of trustworthiness provided by all observers, but with the competence ratings of older observers only. Interestingly, older adults provided higher ratings of perceived competence and trustworthiness to younger than older faces. However, our results also suggest that higher attractiveness ratings, together

Perceptual and Social Attributes Underlining Age-Related Preferences for Faces

Science.gov (United States)

Kiiski, Hanni S. M.; Cullen, Brendan; Clavin, Sarah L.; Newell, Fiona N.

2016-01-01

Although aesthetic preferences are known to be important in person perception and can play a significant role in everyday social decisions, the effect of the age of the observer on aesthetic preferences for faces of different ages has not yet been fully investigated. In the present study we investigated whether aesthetic preferences change with aging, with an age-related bias in favoring faces from one’s own age group. In addition, we examined the role of age on both the perceptual qualities and the social attributes of faces that may influence these aesthetic judgements. Both younger and older adult observers provided ratings to images of younger, middle-aged and older unfamiliar faces. As well as attractiveness, the rating dimensions included other perceptual (distinctiveness, familiarity) and social (competence, trustworthiness and dominance) factors. The results suggested a consistent aesthetic preference for youthful faces across all ages of the observers but, surprisingly, no evidence for an age-related bias in attractiveness ratings. Older adults tended to provide higher ratings of attractiveness, competence and trustworthiness to the unfamiliar faces, consistent with the positivity effect previously reported. We also tested whether perceptual factors such as face familiarity or distinctiveness affected aesthetic ratings. Only ratings of familiarity, but not distinctiveness, were positively associated with the attractiveness of the faces. Moreover, ratings of familiarity decreased with increasing age of the face. With regard to the social characteristics of the faces, we found that the age of the face negatively correlated with ratings of trustworthiness provided by all observers, but with the competence ratings of older observers only. Interestingly, older adults provided higher ratings of perceived competence and trustworthiness to younger than older faces. However, our results also suggest that higher attractiveness ratings, together with older aged

Age-related changes in crowding and reading speed

OpenAIRE

Liu, Rong; Patel, Bhavika N.; Kwon, MiYoung

2017-01-01

Crowding, the inability to recognize objects in clutter, is known to play a role in developmental changes in reading speed. Here, we investigated whether crowding also plays a role in age-related changes in reading speed. We recruited 18 young (mean age: 22.6???3.5; range: 18~31) and 21 older adults (mean age: 58.2???7.0; range: 50~73) with normal vision. Reading speed was measured with short blocks of text. The degree of crowding was determined by measuring crowding zone (the distance betwee...

Vitamin D Deficiency in Community-Dwelling Elderly Is Not Associated with Age-Related Macular Degeneration.

Science.gov (United States)

Cougnard-Grégoire, Audrey; Merle, Bénédicte M J; Korobelnik, Jean-Francois; Rougier, Marie-Bénédicte; Delyfer, Marie-Noëlle; Féart, Catherine; Le Goff, Mélanie; Dartigues, Jean-François; Barberger-Gateau, Pascale; Delcourt, Cécile

2015-08-01

Elderly persons are at elevated risk of vitamin D deficiency, which is involved in various health problems. However, its relation with age-related macular degeneration (AMD) is debated. We investigated factors associated with plasma 25-hydroxyvitamin D [25(OH)D] deficiency and the associations between plasma 25(OH)D concentrations and AMD in elderly subjects. Antioxydants, Lipides Essentiels, Nutrition et maladies OculaiRes (ALIENOR) is a population-based study on eye diseases performed in elderly residents of Bordeaux, France. Plasma 25(OH)D concentrations were assessed from blood samples and categorized as D status were examined with multinomial logistic regression analysis. Associations between AMD and plasma 25(OH)D status were estimated using generalized estimating equation logistic regressions. Six hundred ninety-seven subjects with complete data were included. The prevalence of plasma 25(OH)D deficiency and insufficiency were 27.3% and 55.9%, respectively. In multivariate analysis, 25(OH)D deficiency was significantly associated with older age (P = 0.0007), females (P = 0.0007), absence of physical activity (P = 0.01), absence of vitamin D supplementation (P D insufficiency or deficiency (OR: 0.71, P = 0.12; OR: 0.73, P = 0.23, respectively) or with late AMD (OR: 1.04, P = 0.93; OR: 0.74, P = 0.59, respectively). These findings underline the very high prevalence of plasma 25(OH)D deficiency in this elderly population but do not support a specific role for vitamin D in AMD. © 2015 American Society for Nutrition.

On the fluid-dynamical approximation to the Boltzmann equation at the level of the Navier-Stokes equation

International Nuclear Information System (INIS)

Kawashima, S.; Matsumara, A.; Nishida, T.

1979-01-01

The compressible and heat-conductive Navier-Stokes equation obtained as the second approximation of the formal Chapman-Enskog expansion is investigated on its relations to the original nonlinear Boltzmann equation and also to the incompressible Navier-Stokes equation. The solutions of the Boltzmann equation and the incompressible Navier-Stokes equation for small initial data are proved to be asymptotically equivalent (mod decay rate tsup(-5/4)) as t → + infinitely to that of the compressible Navier-Stokes equation for the corresponding initial data. (orig.) 891 HJ/orig. 892 MKO

Weierstrass Elliptic Function Solutions to Nonlinear Evolution Equations

International Nuclear Information System (INIS)

Yu Jianping; Sun Yongli

2008-01-01

This paper is based on the relations between projection Riccati equations and Weierstrass elliptic equation, combined with the Groebner bases in the symbolic computation. Then the novel method for constructing the Weierstrass elliptic solutions to the nonlinear evolution equations is given by using the above relations

Psychophysical function in age-related maculopathy.

LENUS (Irish Health Repository)

Neelam, Kumari

2012-02-01

Age-related macular degeneration (AMD), the late stage of age-related maculopathy (ARM), is the leading cause of blind registration in developed countries. The visual loss in AMD occurs due to dysfunction and death of photoreceptors (rods and cones) secondary to an atrophic or a neovascular event. The psychophysical tests of vision, which depend on the functional status of the photoreceptors, may detect subtle alterations in the macula before morphological fundus changes are apparent ophthalmoscopically, and before traditional measures of visual acuity exhibit deterioration, and may be a useful tool for assessing and monitoring patients with ARM. Furthermore, worsening of these visual functions over time may reflect disease progression, and some of these, alone or in combination with other parameters, may act as a prognostic indicator for identifying eyes at risk for developing neovascular AMD. Lastly, psychophysical tests often correlate with subjective and relatively undefined symptoms in patients with early ARM, and may reflect limitation of daily activities for ARM patients. However, clinical studies investigating psychophysical function have largely been cross-sectional in nature, with small sample sizes, and lack consistency in terms of the grading and classification of ARM. This article aims to comprehensively review the literature germane to psychophysical tests in ARM, and to furnish the reader with an insight into this complex area of research.

Linear integral equations and soliton systems

International Nuclear Information System (INIS)

Quispel, G.R.W.

1983-01-01

A study is presented of classical integrable dynamical systems in one temporal and one spatial dimension. The direct linearizations are given of several nonlinear partial differential equations, for example the Korteweg-de Vries equation, the modified Korteweg-de Vries equation, the sine-Gordon equation, the nonlinear Schroedinger equation, and the equation of motion for the isotropic Heisenberg spin chain; the author also discusses several relations between these equations. The Baecklund transformations of these partial differential equations are treated on the basis of a singular transformation of the measure (or equivalently of the plane-wave factor) occurring in the corresponding linear integral equations, and the Baecklund transformations are used to derive the direct linearization of a chain of so-called modified partial differential equations. Finally it is shown that the singular linear integral equations lead in a natural way to the direct linearizations of various nonlinear difference-difference equations. (Auth.)

Hyperbolic partial differential equations

CERN Document Server

Witten, Matthew

1986-01-01

Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M

ANTHROPOMETRIC PREDICTIVE EQUATIONS FOR ...

African Journals Online (AJOL)

Keywords: Anthropometry, Predictive Equations, Percentage Body Fat, Nigerian Women, Bioelectric Impedance ... such as Asians and Indians (Pranav et al., 2009), ... size (n) of at least 3o is adjudged as sufficient for the ..... of people, gender and age (Vogel eta/., 1984). .... Fish Sold at Ile-Ife Main Market, South West Nigeria.

Age-related increase in brain activity during task-related and -negative networks and numerical inductive reasoning.

Science.gov (United States)

Sun, Li; Liang, Peipeng; Jia, Xiuqin; Qi, Zhigang; Li, Kuncheng

2014-01-01

Recent neuroimaging studies have shown that elderly adults exhibit increased and decreased activation on various cognitive tasks, yet little is known about age-related changes in inductive reasoning. To investigate the neural basis for the aging effect on inductive reasoning, 15 young and 15 elderly subjects performed numerical inductive reasoning while in a magnetic resonance (MR) scanner. Functional magnetic resonance imaging (fMRI) analysis revealed that numerical inductive reasoning, relative to rest, yielded multiple frontal, temporal, parietal, and some subcortical area activations for both age groups. In addition, the younger participants showed significant regions of task-induced deactivation, while no deactivation occurred in the elderly adults. Direct group comparisons showed that elderly adults exhibited greater activity in regions of task-related activation and areas showing task-induced deactivation (TID) in the younger group. Our findings suggest an age-related deficiency in neural function and resource allocation during inductive reasoning.

Application of quality assurance program to safety related aging equipment or components

International Nuclear Information System (INIS)

Papaiya, N.C.

1990-01-01

This paper addresses how quality assurance programs and their criteria are applied to safety related and aging equipment or components used in commercial nuclear plant applications. The QA Programs referred to are 10CFR50 Appendix B and EPRI NP-5652. The QA programs as applicable are applied to equipment/component aging qualification, preventive maintenance, surveillance testing and procurement engineering. The intent of this paper is not the technical issues, methods and research of aging. The paper addresses QA program's application to age-related equipment or components in safety related applications. Quality Assurance Program 10CFR50 Appendix B applies to all safety related aging components or equipment related to the qualification program and associated preventive maintenance and surveillance testing programs. Quality Assurance involvement with procurement engineering for age-related commercial grade items supports EPRI NP-5652 and assures that the dedicated OGI is equal to the item purchased as a basic component to 10CFR50 Appendix B requirements

Age-related associative deficits and the isolation effect.

Science.gov (United States)

Badham, Stephen P; Maylor, Elizabeth A

2013-01-01

If all but one of the items in a list are similar (e.g., all black except one red), memory for the different item is enhanced (the isolation effect). Older adults generally show similar or smaller isolation effects compared to young adults, which has been attributed to age-related deficits in associative memory whereby older adults are less able to associate an isolated stimulus to its isolating feature. Experiment 1 examined the isolation effect for isolation based on spatial position, modality and color; in Experiment 2, the criterion for isolation was the associative relation between stimuli. The results consistently showed no differences between young and older participants in the magnitude of the isolation effect. Whilst age deficits in associative memory may act to reduce the isolation effect in older adults, age deficits in self-initiated processing and inhibitory functionality may counteract this reduction by enhancing the isolation effect in older adults.

Differential Equations Compatible with KZ Equations

International Nuclear Information System (INIS)

Felder, G.; Markov, Y.; Tarasov, V.; Varchenko, A.

2000-01-01

We define a system of 'dynamical' differential equations compatible with the KZ differential equations. The KZ differential equations are associated to a complex simple Lie algebra g. These are equations on a function of n complex variables z i taking values in the tensor product of n finite dimensional g-modules. The KZ equations depend on the 'dual' variable in the Cartan subalgebra of g. The dynamical differential equations are differential equations with respect to the dual variable. We prove that the standard hypergeometric solutions of the KZ equations also satisfy the dynamical equations. As an application we give a new determinant formula for the coordinates of a basis of hypergeometric solutions

Age-related changes in normal adult pancreas: MR imaging evaluation

International Nuclear Information System (INIS)

Sato, Tomohiro; Ito, Katsuyoshi; Tamada, Tsutomu; Sone, Teruki; Noda, Yasufumi; Higaki, Atsushi; Kanki, Akihiko; Tanimoto, Daigo; Higashi, Hiroki

2012-01-01

Objective: To investigate age-related changes in normal adult pancreas as identified by magnetic resonance imaging (MRI). Materials and methods: We examined 115 patients without pancreatic diseases (21–90 years) who underwent upper abdominal MRI to evaluate the normal pancreatic MRI findings related to aging. The parameters examined were the pancreatic anteroposterior (AP) diameter, pancreatic lobulation, pancreatic signal intensity (SI), depiction of the main pancreatic duct (MPD), grade of the visual SI decrease on the opposed-phase T1-weighted images compared with in-phase images, and enhancement effect of the pancreas in the arterial phase of dynamic imaging. Results: The pancreatic AP diameter significantly reduced (head, p = 0.0172; body, p = 0.0007; tail, p < 0.0001), and lobulation (p < 0.0001) and parenchymal fatty change (p < 0.0001) became more evident with aging. No significant correlation was observed between aging and pancreatic SI, however the SI on the in-phase T1-weighted images tended to decrease with aging. No significant correlation was observed between aging and the depiction of the MPD as well as aging and contrast enhancement. Conclusion: MRI findings of pancreatic atrophy, lobulation, and fatty degeneration are characteristic changes related to aging, and it is necessary to recognize these changes in the interpretation of abdominal MRI in patients with and without pancreatic disease

[Factors Related to Presenteeism in Young and Middle-aged Nurses].

Science.gov (United States)

Yoshida, Mami; Miki, Akiko

2018-04-03

Presenteeism is considered to be not only a work-related stressor but also a factor involved in the development of workaholism and error proneness, which is often described as careless. Additionally, increasing health issues arising from aging suggest the possibility that presenteeism in middle-aged nurses is different than that in young ones. Therefore, the present study aimed to identify and tease apart factors involved in presenteeism among young and middle-aged nurses. An anonymous self-administered questionnaire survey was conducted among 2,006 nurses working at 10 hospitals. In total, 761 nurses aged nurses aged ≥40 years were enrolled in this study. Work Impairment Scores (WIS) on the Japanese version of the Stanford Presenteeism Scale were measured for presenteeism. Job stressors, workaholism, and error proneness were measured for related factors. Multiple regression analysis was conducted after determining the WIS as the dependent variable and related factors as independent variables. Overall, 70.8% of the young nurses reported health problems compared to 82.5% of the middle-aged nurses. However, WIS in young nurses was significantly higher than that in middle-aged ones (p nurses showed a significant relationship with the degree of stressors, "difficulty of work" (β = 0.28, p nurses showed a significant relationship with "cognitive narrowing" (β = 0.29, p nurses does not necessarily lower their working capacity. Also, compared to young nurses, the degree of failing tendency, rather than the degree of job stressors, was more related to presenteeism for middle-aged nurses. It can be considered that middle-aged nurses simply realize that their working ability is hindered because of incidents resulting from attention narrowing. As fatigue and state of tension tend to cause narrowing of attention, it may be necessary to reduce such risks and adjust work environments so mistakes can be avoided.

Recent advances in treatment of wet age-related macular degeneration

Directory of Open Access Journals (Sweden)

Ming Li

2015-02-01

Full Text Available Age-related macular degeneration(AMDis one of the important eye diseases of the WHO present three big blindness, is one of the main blinding eye disease in people over the age of 50, people over the age of 65, about 2% of the disease caused by monocular blindness, as the population ages, AMD prevalence is increasing in our country. AMD with respect to its clinical manifestations can be divided into dry AMD and wet AMD, wet AMD is the most harmful for the vision of patients, at present there are many treatments for AMD(mainly for wet age-related macular degeneration, mainly including laser treatment, drug therapy, surgical treatment, gene therapy,etc. The treatments of AMD would be illuminated in this article.

The GUP and quantum Raychaudhuri equation

Science.gov (United States)

Vagenas, Elias C.; Alasfar, Lina; Alsaleh, Salwa M.; Ali, Ahmed Farag

2018-06-01

In this paper, we compare the quantum corrections to the Schwarzschild black hole temperature due to quadratic and linear-quadratic generalised uncertainty principle, with the corrections from the quantum Raychaudhuri equation. The reason for this comparison is to connect the deformation parameters β0 and α0 with η which is the parameter that characterises the quantum Raychaudhuri equation. The derived relation between the parameters appears to depend on the relative scale of the system (black hole), which could be read as a beta function equation for the quadratic deformation parameter β0. This study shows a correspondence between the two phenomenological approaches and indicates that quantum Raychaudhuri equation implies the existence of a crystal-like structure of spacetime.

Relative age and age sequence of fractions of soil organic matter

International Nuclear Information System (INIS)

Scharpenseel, H.W.

1975-01-01

Natural radiocarbon measurements on soil fractions provide information regarding the chances of separating the ''old biologically inert carbon'' out of samples of recent soil material. Beyond this, the relative fraction ages are scrutinized for the sequential order of the origin of the fractions within the biosynthetic reaction chain of soil humic matter. Among all fractions compared (classic humic matter fractionation by alkali and acid treatment; successive extraction with organic solvents of increasing polarity; separation according to particle size by Sephadex gel filtration; hydrolysis residue) the 6 n HCl hydrolysis residue shows the most consistent significant age increment. Repeated exhaustive hydrolysis treatment of the same sample material is still pending. All other fraction types indicate an age pattern under strong predetermination by method of origin, e.g., existence or lack of hydromorphy, without an evident enrichment of the ''old biologically inert carbon''. Among the organic extracts, no persistent age hierarchy is noticeable, whereas the classical fractions follow an age sequence mainly parallel to an increase of the molecular weight. Hymatomelanic acids appear rejuvenated by relics of recent carbon derived from the extractant ethanol. Grey humic acids are older than the brown humic acids, humines from fully terrestrial soil environment are older than humic acids, while in hydromorphic soils, cold alkali insoluble young C-compounds seem to be conserved which are liable to falsify rejuvenation of the humines

Teasing apart the relations between age, birth cohort, and vocational interests.

Science.gov (United States)

Leuty, Melanie E; Hansen, Jo-Ida C

2014-04-01

Empirical evidence supports that aging is related to differences in work attitudes and motivation (Inceoglu, Segers, & Bartram, 2012; Kooij, de Lange, Jansen, Kanfer, & Kikkers, 2011; Ng & Feldman, 2008, 2010), but little research has explored the relations between age and vocational interests. Furthermore, recent studies of age and work attitudes suggest that generational experiences (i.e., birth year) may account for age differences in the workplace (Inceoglu et al., 2012; Ng & Feldman, 2008, 2010), which in turn suggests that researchers need to incorporate both age and birth cohort effects in their designs. Thus, this study was designed to explore the relations of age at the time of testing and birth year to vocational interests using a sample of adults (N = 1,792) collected over a period of 3 decades. As expected, age was not a significant predictor of most interests, but birth year also was not found to predict most interests, with the significant prediction of Realistic interests by both age and birth year being the exception. Gender, however, significantly predicted most areas of interests. Neither age nor gender moderated any relationships between birth year and interests. Results suggest that birth year and age were minimally related to interests as all effect sizes were small. Discussion of the results illustrates the need for further research on this issue and also offers considerations for attracting and retaining different generations of workers in light of the findings. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Genetics Home Reference: age-related hearing loss

Science.gov (United States)

... quality of life. Because affected individuals have trouble understanding speech, the condition affects their ability to communicate. It can contribute to social isolation, depression, and loss of self-esteem. Age-related hearing loss also causes safety issues if individuals become ...

Gender effects on age-related changes in brain structure.

Science.gov (United States)

Xu, J; Kobayashi, S; Yamaguchi, S; Iijima, K; Okada, K; Yamashita, K

2000-01-01

Previous reports have suggested that brain atrophy is associated with aging and that there are gender differences in brain atrophy with aging. These reports, however, neither exclude silent brain lesions in "healthy subjects" nor divide the brain into subregions. The aim of this study is to clarify the effect of gender on age-related changes in brain subregions by MR imaging. A computer-assisted system was used to calculate the brain matter area index (BMAI) of various regions of the brain from MR imaging of 331 subjects without brain lesions. There was significantly more brain atrophy with aging in the posterior parts of the right frontal lobe in male subjects than there was in female subjects. Age-related atrophy in the middle part of the right temporal lobe, the left basal ganglia, the parietal lobe, and the cerebellum also was found in male subjects, but not in female subjects. In the temporal lobe, thalamus, parieto-occipital lobe, and cerebellum, brain volume in the left hemisphere is significantly smaller than in the right hemisphere; sex and age did not affect the hemisphere differences of brain volume in these regions. The effect of gender on brain atrophy with aging varied in different subregions of the brain. There was more brain atrophy with aging in male subjects than in female subjects.

NATO Advanced Research Workshop on Approximation by Solutions of Partial Differential Equations, Quadrature Formulae, and Related Topics

CERN Document Server

Goldstein, M; Haussmann, W; Hayman, W; Rogge, L

1992-01-01

This volume consists of the proceedings of the NATO Advanced Research Workshop on Approximation by Solutions of Partial Differential Equations, Quadrature Formulae, and Related Topics, which was held at Hanstholm, Denmark. These proceedings include the main invited talks and contributed papers given during the workshop. The aim of these lectures was to present a selection of results of the latest research in the field. In addition to covering topics in approximation by solutions of partial differential equations and quadrature formulae, this volume is also concerned with related areas, such as Gaussian quadratures, the Pompelu problem, rational approximation to the Fresnel integral, boundary correspondence of univalent harmonic mappings, the application of the Hilbert transform in two dimensional aerodynamics, finely open sets in the limit set of a finitely generated Kleinian group, scattering theory, harmonic and maximal measures for rational functions and the solution of the classical Dirichlet problem. In ...

On a complex differential Riccati equation

International Nuclear Information System (INIS)

Khmelnytskaya, Kira V; Kravchenko, Vladislav V

2008-01-01

We consider a nonlinear partial differential equation for complex-valued functions which is related to the two-dimensional stationary Schroedinger equation and enjoys many properties similar to those of the ordinary differential Riccati equation such as the famous Euler theorems, the Picard theorem and others. Besides these generalizations of the classical 'one-dimensional' results, we discuss new features of the considered equation including an analogue of the Cauchy integral theorem

An interpolation between the wave and diffusion equations through the fractional evolution equations Dirac like

International Nuclear Information System (INIS)

Pierantozzi, T.; Vazquez, L.

2005-01-01

Through fractional calculus and following the method used by Dirac to obtain his well-known equation from the Klein-Gordon equation, we analyze a possible interpolation between the Dirac and the diffusion equations in one space dimension. We study the transition between the hyperbolic and parabolic behaviors by means of the generalization of the D'Alembert formula for the classical wave equation and the invariance under space and time inversions of the interpolating fractional evolution equations Dirac like. Such invariance depends on the values of the fractional index and is related to the nonlocal property of the time fractional differential operator. For this system of fractional evolution equations, we also find an associated conserved quantity analogous to the Hamiltonian for the classical Dirac case

New developments in age-related macular degeneration

Directory of Open Access Journals (Sweden)

Lyndon da Cruz

2008-09-01

Full Text Available The World Health Organization (WHO estimates that over 3 million people (9% of global blindness are blinded by age-related macular degeneration (AMD. AMD affects people over the age of 55. There are two main types of AMD, dry and wet. In dry AMD, patients slowly lose vision through progressive atrophy of the macular tissue. Wet, or exudative, AMD, is associated with new blood vessels called subretinal neovascular membranes (or SRNVM and affected patients lose vision more rapidly due to fluid leakage and haemorrhage at the macula.

Age Differences in Brain Activity during Emotion Processing: Reflections of Age-Related Decline or Increased Emotion Regulation?

Science.gov (United States)

Nashiro, Kaoru; Sakaki, Michiko; Mather, Mara

2012-01-01

Despite the fact that physical health and cognitive abilities decline with aging, the ability to regulate emotion remains stable and in some aspects improves across the adult life span. Older adults also show a positivity effect in their attention and memory, with diminished processing of negative stimuli relative to positive stimuli compared with younger adults. The current paper reviews functional magnetic resonance imaging studies investigating age-related differences in emotional processing and discusses how this evidence relates to two opposing theoretical accounts of older adults’ positivity effect. The aging-brain model [Cacioppo et al. in: Social Neuroscience: Toward Understanding the Underpinnings of the Social Mind. New York, Oxford University Press, 2011] proposes that older adults’ positivity effect is a consequence of age-related decline in the amygdala, whereas the cognitive control hypothesis [Kryla-Lighthall and Mather in: Handbook of Theories of Aging, ed 2. New York, Springer, 2009; Mather and Carstensen: Trends Cogn Sci 2005;9:496–502; Mather and Knight: Psychol Aging 2005;20:554–570] argues that the positivity effect is a result of older adults’ greater focus on regulating emotion. Based on evidence for structural and functional preservation of the amygdala in older adults and findings that older adults show greater prefrontal cortex activity than younger adults while engaging in emotion-processing tasks, we argue that the cognitive control hypothesis is a more likely explanation for older adults’ positivity effect than the aging-brain model. PMID:21691052

Age and gender related differences in aortic blood flow

DEFF Research Database (Denmark)

Traberg, Marie Sand; Pedersen, Mads Møller; Hemmsen, Martin Christian

2012-01-01

The abdominal aorta (AA) is predisposed to development of abdominal aneurysms (AAA), a focal dilatation of the artery with fatal consequences if left untreated. The blood flow patterns in the AA is thought to play an important role in the development of AAA. The purpose of this work is to investi......The abdominal aorta (AA) is predisposed to development of abdominal aneurysms (AAA), a focal dilatation of the artery with fatal consequences if left untreated. The blood flow patterns in the AA is thought to play an important role in the development of AAA. The purpose of this work...... is to investigate the blood flow pat- terns within a group of healthy volunteers (4 females, 7 males) aged 23 to 76 years to identify changes and differences related to age and gender. The healthy volunteers were categorized by gender (male/female) and age (below/above 35 years). Subject-specific flow and geometry...... to elderly. Thus, changes in blood flow patterns in the AA related to age and gender is observed. Further investigations are needed to determine the relation between changes in blood flow patterns and AAA development....

Identification of Age-Related Macular Degeneration Using OCT Images

Science.gov (United States)

Arabi, Punal M., Dr; Krishna, Nanditha; Ashwini, V.; Prathibha, H. M.

2018-02-01

Age-related Macular Degeneration is the most leading retinal disease in the recent years. Macular degeneration occurs when the central portion of the retina, called macula deteriorates. As the deterioration occurs with the age, it is commonly referred as Age-related Macular Degeneration. This disease can be visualized by several imaging modalities such as Fundus imaging technique, Optical Coherence Tomography (OCT) technique and many other. Optical Coherence Tomography is the widely used technique for screening the Age-related Macular Degeneration disease, because it has an ability to detect the very minute changes in the retina. The Healthy and AMD affected OCT images are classified by extracting the Retinal Pigmented Epithelium (RPE) layer of the images using the image processing technique. The extracted layer is sampled, the no. of white pixels in each of the sample is counted and the mean value of the no. of pixels is calculated. The average mean value is calculated for both the Healthy and the AMD affected images and a threshold value is fixed and a decision rule is framed to classify the images of interest. The proposed method showed an accuracy of 75%.

Age-related differences in emotion recognition ability: a cross-sectional study.

Science.gov (United States)

Mill, Aire; Allik, Jüri; Realo, Anu; Valk, Raivo

2009-10-01

Experimental studies indicate that recognition of emotions, particularly negative emotions, decreases with age. However, there is no consensus at which age the decrease in emotion recognition begins, how selective this is to negative emotions, and whether this applies to both facial and vocal expression. In the current cross-sectional study, 607 participants ranging in age from 18 to 84 years (mean age = 32.6 +/- 14.9 years) were asked to recognize emotions expressed either facially or vocally. In general, older participants were found to be less accurate at recognizing emotions, with the most distinctive age difference pertaining to a certain group of negative emotions. Both modalities revealed an age-related decline in the recognition of sadness and -- to a lesser degree -- anger, starting at about 30 years of age. Although age-related differences in the recognition of expression of emotion were not mediated by personality traits, 2 of the Big 5 traits, openness and conscientiousness, made an independent contribution to emotion-recognition performance. Implications of age-related differences in facial and vocal emotion expression and early onset of the selective decrease in emotion recognition are discussed in terms of previous findings and relevant theoretical models.

Absolute and Relative Socioeconomic Health Inequalities across Age Groups

NARCIS (Netherlands)

van Zon, Sander K. R.; Bultmann, Ute; de Leon, Carlos F. Mendes; Reijneveld, Sijmen A.

2015-01-01

Background The magnitude of socioeconomic health inequalities differs across age groups. It is less clear whether socioeconomic health inequalities differ across age groups by other factors that are known to affect the relation between socioeconomic position and health, like the indicator of

Birth Order, Age-Spacing, IQ Differences, and Family Relations.

Science.gov (United States)

Pfouts, Jane H.

1980-01-01

Very close age spacing was an obstacle to high academic performance for later borns. In family relations and self-esteem, first borns scored better and performed in school as well as their potentially much more able younger siblings, regardless of age spacing. (Author)

PATTERNS OF FUNDUS AUTOFLUORESCENCE DEFECTS IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION SUBTYPES.

Science.gov (United States)

Ozkok, Ahmet; Sigford, Douglas K; Tezel, Tongalp H

2016-11-01

To test define characteristic fundus autofluorescence patterns of different exudative age-related macular degeneration subtypes. Cross-sectional study. Fifty-two patients with choroidal neovascularization because of three different neovascular age-related macular degeneration subtypes were included in the study. Macular and peripheral fundus autofluorescence patterns of study subjects were compared in a masked fashion. Fundus autofluorescence patterns of all three neovascular age-related macular degeneration subtypes revealed similar patterns. However, peripapillary hypo-autofluorescence was more common among patients with polypoidal choroidal vasculopathy (88.2%) compared with patients with retinal angiomatous proliferation (12.5%) and patients without retinal angiomatous proliferation and polypoidal choroidal vasculopathy (21.1%) (P autofluorescence defects in neovascular age-related macular degeneration maybe suggestive of polypoidal choroidal vasculopathy as a variant of neovascular age-related macular degeneration.

Therapeutic potential of eccentric exercises for age-related muscle atrophy

Directory of Open Access Journals (Sweden)

Jae-Young Lim

2016-09-01

Full Text Available Recent studies have focused on evidence-based interventions to prevent mobility decline and enhance physical performance in older adults. Several modalities, in addition to traditional strengthening programs, have been designed to manage age-related functional decline more effectively. In this study, we reviewed the current relevant literatures to assess the therapeutic potential of eccentric exercises for age-related muscle atrophy (sarcopenia. Age-related changes in human skeletal muscle, and their relationship with physical performance, are discussed with reference to in vitro physiologic and human biomechanics studies. An overview of issues relevant to sarcopenia is provided in the context of the recent consensus on the diagnosis and management of the condition. A decline in mobility among the aging population is closely linked with changes in the muscle force–velocity relationship. Interventions based specifically on increasing velocity and eccentric strength can improve function more effectively compared with traditional strengthening programs. Eccentric strengthening programs are introduced as a specific method for improving both muscle force and velocity. To be more effective, exercise interventions for older adults should focus on enhancing the muscle force–velocity relationship. Exercises that can be performed easily, and that utilize eccentric strength (which is relatively spared during the aging process, are needed to improve both muscle force and velocity.

Age-Related Neurodegeneration and Memory Loss in Down Syndrome

Directory of Open Access Journals (Sweden)

Jason P. Lockrow

2012-01-01

Full Text Available Down syndrome (DS is a condition where a complete or segmental chromosome 21 trisomy causes variable intellectual disability, and progressive memory loss and neurodegeneration with age. Many research groups have examined development of the brain in DS individuals, but studies on age-related changes should also be considered, with the increased lifespan observed in DS. DS leads to pathological hallmarks of Alzheimer's disease (AD by 40 or 50 years of age. Progressive age-related memory deficits occurring in both AD and in DS have been connected to degeneration of several neuronal populations, but mechanisms are not fully elucidated. Inflammation and oxidative stress are early events in DS pathology, and focusing on these pathways may lead to development of successful intervention strategies for AD associated with DS. Here we discuss recent findings and potential treatment avenues regarding development of AD neuropathology and memory loss in DS.

Prediction and characterization of human ageing-related proteins by using machine learning.

Science.gov (United States)

Kerepesi, Csaba; Daróczy, Bálint; Sturm, Ádám; Vellai, Tibor; Benczúr, András

2018-03-06

Ageing has a huge impact on human health and economy, but its molecular basis - regulation and mechanism - is still poorly understood. By today, more than three hundred genes (almost all of them function as protein-coding genes) have been related to human ageing. Although individual ageing-related genes or some small subsets of these genes have been intensively studied, their analysis as a whole has been highly limited. To fill this gap, for each human protein we extracted 21000 protein features from various databases, and using these data as an input to state-of-the-art machine learning methods, we classified human proteins as ageing-related or non-ageing-related. We found a simple classification model based on only 36 protein features, such as the "number of ageing-related interaction partners", "response to oxidative stress", "damaged DNA binding", "rhythmic process" and "extracellular region". Predicted values of the model quantify the relevance of a given protein in the regulation or mechanisms of the human ageing process. Furthermore, we identified new candidate proteins having strong computational evidence of their important role in ageing. Some of them, like Cytochrome b-245 light chain (CY24A) and Endoribonuclease ZC3H12A (ZC12A) have no previous ageing-associated annotations.

Perceptions of aging among middle-aged offspring of traumatized parents: the effects of parental Holocaust-related communication and secondary traumatization.

Science.gov (United States)

Shrira, Amit

2016-01-01

Traumatized parents may transmit anxieties of physical deterioration and demise to their offspring. These anxieties can amplify negative perceptions of the aging process when the offspring enter old age. The current study examined how middle-aged offspring of Holocaust survivors (OHS) recount trauma-related communication by their parents, and how these reports are related to offspring's perceptions of their aging process. The study included 450 respondents at the age range of 50-67 (mean age = 57.5, SD = 4.6): 300 OHS and 150 comparisons. Participants reported parental communication of the Holocaust, completed measures of subjective successful aging, aging and death anxieties, and reported secondary traumatization assessing symptoms, developed as a result of a close and continuous relationship with a traumatized parent. Latent profile analysis identified two profiles of parental Holocaust-related communication: intrusive and informative. Offspring who reported intrusive parental communication about the Holocaust perceived themselves as aging less successfully and were more anxious of aging and death than comparisons. Offspring who reported informative parental communication and comparisons did not differ in perceptions of aging. Secondary traumatization mediated these group differences, meaning, intrusive parental communication was related to higher secondary traumatization, which in turn was related to less favorable perceptions of aging. These findings allude to the possibility that secondary traumatization mold negative perceptions of the aging process among middle-aged offspring of traumatized parents. Mental health practitioners may help OHS process fragmented and intrusive remnants of parental trauma, thereby diminishing secondary traumatization, and promoting more adaptive perceptions of aging.

Radiation treatment for age-related macular degeneration

Energy Technology Data Exchange (ETDEWEB)

Taniguchi, Tomoko; Mandai, Michiko; Honjo, Megumi; Matsuda, Naoko; Miyamoto, Hideki; Takahashi, Masayo; Ogura, Yuichiro; Sasai, Keisuke [Kyoto Univ. (Japan). Faculty of Medicine

1996-11-01

Fifteen eyes of age-related macular degeneration were treated by low-dose radiation. All the affected eyes had subfoveal neovascular membrane. Seventeen nontreated eyes with similar macular lesion served as control. Radiation was performed using photon beam at 6MV. Each eye received daily dose of 2 Gy for 5 consecutive days. When evaluated 9 to 12 months after treatment, the size of neovascular membrane had decreased in 47% of treated eyes and 7% of control eyes. The visual acuity improved by 2 lines or more in 13% of treated eyes and in none of control eyes. When the initial neovascular membrane was less than 1.5 disc diameter in size, the visual acuity had improved or remained stationary in 90% of treated eyes and in 36% of control eyes. The findings show the potential beneficial effect of radiation for age-related macular degeneration. (author)

Relation of Age at Menarche to Physical Activity

Directory of Open Access Journals (Sweden)

Egreta Peja

2016-10-01

Full Text Available The aim of this study is to determine whether regular physical activity during early puberty is influential in preventing early menarche. This cross sectional study was carried out on 102 post-menarcheal girls aged 11–20 (14.79±0.33. 51 of them were already engaged in competitive sport activities prior to the onset of menstruation (group 1, while the others got engaged in such activities after the onset of menstruation (group 2. All participants provided the year and the month of their first menstrual period. First, we estimated the equality of dispersion between the two groups, by conducting Two Samples for Variances F-test. Second, because no homogeneity of variances between groups was found, they were compared by using Two Samples Assuming Unequal Variances t-test. The difference between groups is statistically significant, as the t statistics (=2.883 is greater than both critical t statistics (one-tail=1.664 two-tail=1.990 and the p value less than 0.05 in both cases (one-tail=0.002 two-tail=0.005. None of the girls in the first group starts to menstruate before 11 years of age and 90% of them are menstruating by age 14, with a median age of 12.95±0.35 years. Age of menarche is lower in the second group with a median age of 12.25±0.31 years, thus approximately 8 months lower than median age for the first group. 11.76% of the girls in the second group start to menstruate before 11 years of age and 90% of them are menstruating by age 13. It is rather, the decline in early matures among those engaged in regular physical activity prior to the onset of menses, that makes the statistically significant correlation between physical activity and age at menarche practically meaningful. Relatively early matures (<11 years have been found to be slightly shorter but up to 5.5 kg heavier in adulthood than are late matures. In addition, a relatively young age at menarche has been associated with an increased risk for breast cancer and spontaneous

Association of age-related macular degeneration and reticular macular disease with cardiovascular disease.

Science.gov (United States)

Rastogi, Neelesh; Smith, R Theodore

2016-01-01

Age-related macular degeneration is the leading cause of adult blindness in the developed world. Thus, major endeavors to understand the risk factors and pathogenesis of this disease have been undertaken. Reticular macular disease is a proposed subtype of age-related macular degeneration correlating histologically with subretinal drusenoid deposits located between the retinal pigment epithelium and the inner segment ellipsoid zone. Reticular lesions are more prevalent in females and in older age groups and are associated with a higher mortality rate. Risk factors for developing age-related macular degeneration include hypertension, smoking, and angina. Several genes related to increased risk for age-related macular degeneration and reticular macular disease are also associated with cardiovascular disease. Better understanding of the clinical and genetic risk factors for age-related macular degeneration and reticular macular disease has led to the hypothesis that these eye diseases are systemic. A systemic origin may help to explain why reticular disease is diagnosed more frequently in females as males suffer cardiovascular mortality at an earlier age, before the age of diagnosis of reticular macular disease and age-related macular degeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Age-related slowing of digit symbol substitution revisited: what do longitudinal age changes reflect?

Science.gov (United States)

MacDonald, Stuart W S; Hultsch, David F; Strauss, Esther; Dixon, Roger A

2003-05-01

A previous investigation reported that cross-sectional age differences in Digit Symbol Substitution (DSS) test performance reflect declines in perceptual processing speed. Support for the tenability of the processing speed hypothesis requires examining whether longitudinal age-related change in DSS performance is largely mediated by changes in speed. The present study used data from the Victoria Longitudinal Study to examine patterns and predictors of longitudinal change in DSS for 512 older adults (M(age) = 68.37 years, SD = 7.43). On the basis of multilevel modeling, baseline DSS performance was poorer for older participants and men, with longitudinal declines more pronounced with increasing age and decreasing speed. In contrast to the present cross-sectional findings, statistical control of change trajectories in perceptual speed using the same data did not substantially attenuate age changes. These discrepancies suggest different sources of variance may underlie cross-sectional age differences and longitudinal age changes for DSS.

Are Gestational Age, Birth Weight, and Birth Length Indicators of Favorable Fetal Growth Conditions? A Structural Equation Analysis of Filipino Infants

OpenAIRE

Bollen, Kenneth A.; Noble, Mark D.; Adair, Linda S.

2013-01-01

The fetal origin hypothesis emphasizes the life-long health impacts of prenatal conditions. Birth weight, birth length, and gestational age are indicators of the fetal environment. However, these variables often have missing data and are subject to random and systematic errors caused by delays in measurement, differences in measurement instruments, and human error. With data from the Cebu (Philippines) Longitudinal Health and Nutrition Survey, we use structural equation models (SEMs), to expl...

Cognitive and neuropsychological underpinnings of relational and conjunctive working memory binding across age.

Science.gov (United States)

van Geldorp, Bonnie; Parra, Mario A; Kessels, Roy P C

2015-01-01

The ability to form associations (i.e., binding) is critical for memory formation. Recent studies suggest that aging specifically affects relational binding (associating separate features) but not conjunctive binding (integrating features within an object). Possibly, this dissociation may be driven by the spatial nature of the studies so far. Alternatively, relational binding may simply require more attentional resources. We assessed relational and conjunctive binding in three age groups and we included an interfering task (i.e., an articulatory suppression task). Binding was examined in a working memory (WM) task using non-spatial features: shape and colour. Thirty-one young adults (mean age = 22.35), 30 middle-aged adults (mean age = 54.80) and 30 older adults (mean age = 70.27) performed the task. Results show an effect of type of binding and an effect of age but no interaction between type of binding and age. The interaction between type of binding and interference was significant. These results indicate that aging affects relational binding and conjunctive binding similarly. However, relational binding is more susceptible to interference than conjunctive binding, which suggests that relational binding may require more attentional resources. We suggest that a general decline in WM resources associated with frontal dysfunction underlies age-related deficits in WM binding.

Influence of Biomedical Factors on the Five Viscera Score (FVS on Middle-Aged and Elderly Individuals: Application of Structural Equation Modeling

Directory of Open Access Journals (Sweden)

Taro Tomura

2015-01-01

Full Text Available The five viscera score (FVS is a diagnostic scale for traditional Chinese medicine (TCM. The purposes of current study are to elucidate the characteristics of FVS obtained from middle-aged to elderly individuals and to investigate the validity of FVS using biological medical data of middle-aged and elderly individuals. Structural equation modeling (SEM was used to conduct assessments between FVS and medical data. Eighty men and 99 women participated in this study, whose mean ages (SD were 58 ± 7 years in both genders showing no significant difference. FVS of women was significantly higher than that of men in the spleen of the 50s (P=0.019 and liver of the 60s age group (P=0.030. By SEM, the following biomedical factors were found to influence viscera: gender, diastolic blood pressure, and HDL-C for the liver; GLU, GOT, and γ-GTP for the spleen; age, BMI, and HCRP for the lungs; and HbA1c and creatinine clearance for the kidneys. These results provide objective evidence that FVS can be used for TCM diagnosis in middle-aged and elderly individuals.

[Physical activity diminishes aging-related decline of physical and cognitive performance].

Science.gov (United States)

Apor, Péter; Babai, László

2014-05-25

Aging-related decline of muscle force, walking speed, locomotor coordination, aerobic capacity and endurance exert prognostic impact on life expectancy. Proper use of training may diminish the aging process and it may improve the quality of life of elderly persons. This paper provides a brief summary on the impact of training on aging-related decline of physical and cognitive functions.

Age-Related Racial Disparity in Suicide Rates Among U.S. Youth

Science.gov (United States)

... May 30, 2018 Age-Related Racial Disparity in Youth Suicide Rates May 21, 2018 News by Year 2018 ... May 30, 2018 Age-Related Racial Disparity in Youth Suicide Rates May 21, 2018 News by Year 2018 ...

Assessing Age-Related Etiologic Heterogeneity in the Onset of Islet Autoimmunity

Directory of Open Access Journals (Sweden)

Brittni N. Frederiksen

2015-01-01

Full Text Available Type 1 diabetes (T1D, a chronic autoimmune disease, is often preceded by a preclinical phase of islet autoimmunity (IA where the insulin-producing beta cells of the pancreas are destroyed and circulating autoantibodies can be detected. The goal of this study was to demonstrate methods for identifying exposures that differentially influence the disease process at certain ages by assessing age-related heterogeneity. The Diabetes Autoimmunity Study in the Young (DAISY has followed 2,547 children at increased genetic risk for T1D from birth since 1993 in Denver, Colorado, 188 of whom developed IA. Using the DAISY population, we evaluated putative determinants of IA, including non-Hispanic white (NHW ethnicity, maternal age at birth, and erythrocyte membrane n-3 fatty acid (FA levels, for age-related heterogeneity. A supremum test, weighted Schoenfeld residuals, and restricted cubic splines were used to assess nonproportional hazards, that is, an age-related association of the exposure with IA risk. NHW ethnicity, maternal age, and erythrocyte membrane n-3 FA levels demonstrated a significant age-related association with IA risk. Assessing heterogeneity in disease etiology enables researchers to identify associations that may lead to better understanding of complex chronic diseases.

The GUP and quantum Raychaudhuri equation

Directory of Open Access Journals (Sweden)

Elias C. Vagenas

2018-06-01

Full Text Available In this paper, we compare the quantum corrections to the Schwarzschild black hole temperature due to quadratic and linear-quadratic generalised uncertainty principle, with the corrections from the quantum Raychaudhuri equation. The reason for this comparison is to connect the deformation parameters β0 and α0 with η which is the parameter that characterises the quantum Raychaudhuri equation. The derived relation between the parameters appears to depend on the relative scale of the system (black hole, which could be read as a beta function equation for the quadratic deformation parameter β0. This study shows a correspondence between the two phenomenological approaches and indicates that quantum Raychaudhuri equation implies the existence of a crystal-like structure of spacetime.

The age-related performance decline in ultraendurance mountain biking.

Science.gov (United States)

Haupt, Samuel; Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas; Lepers, Romuald

2013-01-01

The age-related changes in ultraendurance performance have been previously examined for running and triathlon but not mountain biking. The aims of this study were (i) to describe the performance trends and (ii) to analyze the age-related performance decline in ultraendurance mountain biking in a 120-km ultraendurance mountain bike race the "Swiss Bike Masters" from 1995 to 2009 in 9,325 male athletes. The mean (±SD) race time decreased from 590 ± 80 min to 529 ± 88 min for overall finishers and from 415 ± 8 min to 359 ± 16 min for the top 10 finishers, respectively. The mean (±SD) age of all finishers significantly (P Bike Masters" appears to start earlier compared with other ultraendurance sports.

Age-related degradation of boiling water reactor vessel internals

International Nuclear Information System (INIS)

Ware, A.G.; Shah, V.N.

1992-01-01

Researchers at the Idaho National Engineering Laboratory performed an assessment of the aging of the reactor internals in boiling water reactors (BWRs), and identified the unresolved technical issues related to the degradation of these components. The overall life-limiting mechanism is intergranular stress corrosion cracking (IGSCC). Irradiation-assisted stress corrosion cracking, fatigue, and thermal aging embrittlement are other potential degradation mechanisms. Several failures in BWR internals have been caused by a combination of factors such as environment, high residual or preload stresses, and flow-induced vibration. The ASME Code Section XI in-service inspection requirements are insufficient for detecting aging-related degradation at many locations in reactor internals. Many of the potential locations for IGSCC or fatigue are not accessible for inspection. (orig.)

Quantum derivatives and the Schroedinger equation

International Nuclear Information System (INIS)

Ben Adda, Faycal; Cresson, Jacky

2004-01-01

We define a scale derivative for non-differentiable functions. It is constructed via quantum derivatives which take into account non-differentiability and the existence of a minimal resolution for mean representation. This justify heuristic computations made by Nottale in scale-relativity. In particular, the Schroedinger equation is derived via the scale-relativity principle and Newton's fundamental equation of dynamics

Some Functional Equations Originating from Number Theory

Indian Academy of Sciences (India)

We will introduce new functional equations (3) and (4) which are strongly related to well-known formulae (1) and (2) of number theory, and investigate the solutions of the equations. Moreover, we will also study some stability problems of those equations.

The Dirac equation for accountants

International Nuclear Information System (INIS)

Ord, G.N.

2006-01-01

In the context of relativistic quantum mechanics, derivations of the Dirac equation usually take the form of plausibility arguments based on experience with the Schroedinger equation. The primary reason for this is that we do not know what wavefunctions physically represent, so derivations have to rely on formal arguments. There is however a context in which the Dirac equation in one dimension is directly related to a classical generating function. In that context, the derivation of the Dirac equation is an exercise in counting. We provide this derivation here and discuss its relationship to quantum mechanics

The relation between hypochondriasis and age.

Science.gov (United States)

Barsky, A J; Frank, C B; Cleary, P D; Wyshak, G; Klerman, G L

1991-07-01

This study examined the relation between hypochondriasis and age while controlling for the possible confounding influences of medical morbidity, social isolation, and other psychiatric disorder. Consecutive patients attending a general medical clinic on randomly selected days were screened with a hypochondriasis self-report questionnaire. Those whose scores exceeded a preestablished cutoff level and a random sample of those who scored below it completed a research battery consisting of self-report questionnaires and structured interviews for DSM-III-R diagnoses of hypochondriasis and other axis I disorders. The patients' medical records were audited, and their physicians completed questionnaires about them. The 60 patients who met the DSM-III-R criteria for hypochondriasis at interview constituted the study group, and 100 patients randomly chosen from among those who scored below the cutoff for hypochondriasis constituted the comparison group. The hypochondriacal group was not older than the comparison group. Hypochondriacal patients aged 65 years and over did not differ significantly from younger hypochondriacal patients in hypochondriacal attitudes, somatization, tendency to amplify bodily sensation, or global assessment of their overall health, even though their aggregate medical morbidity was greater. The elderly hypochondriacal patients had higher levels of disability, but this appeared to be attributable to their medical status rather than to any increase in hypochondriasis. Within the comparison sample, subjects aged 65 years and over were not more hypochondriacal than those under 65 years of age. Hypochondriasis is found to some degree in all patients and appears to be unrelated to age.

A Discrete Spectral Problem and Related Hierarchy of Discrete Hamiltonian Lattice Equations

International Nuclear Information System (INIS)

Xu Xixiang; Cao Weili

2007-01-01

Staring from a discrete matrix spectral problem, a hierarchy of lattice soliton equations is presented though discrete zero curvature representation. The resulting lattice soliton equations possess non-local Lax pairs. The Hamiltonian structures are established for the resulting hierarchy by the discrete trace identity. Liouville integrability of resulting hierarchy is demonstrated.

Expertise and age-related changes in components of intelligence.

Science.gov (United States)

Masunaga, H; Horn, J

2001-06-01

In a sample of 263 male GO players at 48 levels of expertise and ranging from 18 to 78 years of age, it was found that factors of expertise deductive reasoning (EDR) and expertise working memory (EWM) were independent of factors of fluid reasoning (Gf) and short-term working memory (STWM) that, along with cognitive speed (Gs), have been found to characterize decline of intelligence in adulthood. The main effects of analyses of cross-sectional age differences indicated age-related decline in EDR and EWM as well as in Gf, STWM, and Gs. However, interaction and partialing analyses indicated that decline in EDR and EWM decreased to no decline with increase in level of expertise. The results thus suggest that with increase in factors known to raise the level of expertise--particularly, intensive, well-designed practice--there may be no age-related decline in the intelligence that is measured in the abilities of expertise.

 Age-related changes of skeletal muscles: physiology, pathology and regeneration

Directory of Open Access Journals (Sweden)

Aleksandra Ławniczak

2012-06-01

Full Text Available  This review provides a short presentation of the aging-related changes of human skeletal muscles. The aging process is associated with the loss of skeletal muscle mass (sarcopenia and strength. This results from fibre atrophy and apoptosis, decreased regeneration capacity, mitochondrial dysfunction, gradual reduction of the number of spinal cord motor neurons, and local and systemic metabolic and hormonal alterations. The latter involve age-related decrease of the expression and activity of some mitochondrial and cytoplasmic enzymes, triacylglycerols and lipofuscin accumulation inside muscle fibres, increased proteolytic activity, insulin resistance and decreased serum growth hormone and IGF-1 concentrations. Aging of the skeletal muscles is also associated with a decreased number of satellite cells and their proliferative activity. The age-related reduction of skeletal muscle mass and function may be partially prevented by dietary restriction and systematic physical exercises.

The extended Fan's sub-equation method and its application to KdV-MKdV, BKK and variant Boussinesq equations

International Nuclear Information System (INIS)

Yomba, Emmanuel

2005-01-01

An extended Fan's sub-equation method is used for constructing exact travelling wave solutions of nonlinear partial differential equations (NLPDEs). The key idea of this method is to take full advantage of the general elliptic equation involving five parameters which has more new solutions and whose degeneracies can lead to special sub-equations involving three parameters. More new solutions are obtained for KdV-MKdV, Broer-Kaup-Kupershmidt (BKK) and variant Boussinesq equations. Then we present a technique which not only gives us a clear relation among this general elliptic equation and other sub-equations involving three parameters (Riccati equation, first kind elliptic equation, auxiliary ordinary equation, generalized Riccati equation and so on), but also provides an approach to construct new exact solutions to NLPDEs

Age-related deficits in free recall: the role of rehearsal.

Science.gov (United States)

Ward, Geoff; Maylor, Elizabeth A

2005-01-01

Age-related deficits have been consistently observed in free recall. Recent accounts of episodic memory suggest that these deficits could result from differential patterns of rehearsal. In the present study, 20 young and 20 older adults (mean ages 21 and 72 years, respectively) were presented with lists of 20 words for immediate free recall using the overt rehearsal methodology. The young outperformed the older adults at all serial positions. There were significant age-related differences in the patterns of overt rehearsals: Young adults rehearsed a greater number of different words than did older adults, they rehearsed words to more recent serial positions, and their rehearsals were more widely distributed throughout the list. Consistent with a recency-based account of episodic memory, age deficits in free recall are largely attributable to age differences in the recency, frequency, and distribution of rehearsals.

Local p-Adic Differential Equations

NARCIS (Netherlands)

Put, Marius van der; Taelman, Lenny

2006-01-01

This paper studies divergence in solutions of p-adic linear local differential equations. Such divergence is related to the notion of p-adic Liouville numbers. Also, the influence of the divergence on the differential Galois groups of such differential equations is explored. A complete result is

An inverse problem in a parabolic equation

Directory of Open Access Journals (Sweden)

Zhilin Li

1998-11-01

Full Text Available In this paper, an inverse problem in a parabolic equation is studied. An unknown function in the equation is related to two integral equations in terms of heat kernel. One of the integral equations is well-posed while another is ill-posed. A regularization approach for constructing an approximate solution to the ill-posed integral equation is proposed. Theoretical analysis and numerical experiment are provided to support the method.

Radiation therapy for age-related macular degeneration

Energy Technology Data Exchange (ETDEWEB)

Takagi, Chikako; Mori, Hideo; Akuta, Keizou [Otsu Red Cross Hospital, Shiga (Japan); Yoshimura, Nagahisa

1998-04-01

We evaluated the effect of low-dose radiation on age-related macular degeneration in 8 affected eyes. Radiation was applied using photons at 4 MV. Each eye received 10 fractions of 2 Gy per day over 2 weeks. At 6 months after treatment, funduscopic or angiographic findings had either improved or remained unchanged in all the eyes. The visual acuity improved by 2 lines or more in 2 eyes (25%), remained unchanged in 5 eyes (63%) and deteriorated in 1 eye (13%). At the last examination, fundus findings had improved in 2 eyes (25%), remained unchanged in 1 eye (13%) and deteriorated in 5 eyes (63%). The visual acuity had improved or unchanged in 2 eyes each (25%) and deteriorated in 4 eyes (50%). There has been no negative side effects of radiation. Above findings show that low-dose radiation is potentially beneficial for subfoveal or juxtafoveal choroidal neovascularizations in age-related macular degeneration on a short term basis. (author)

Depth and Elaboration of Processing in Relation to Age.

Science.gov (United States)

Simon, Eileen

1979-01-01

The recall effectiveness of semantic and phonemic cues was compared to uncover the pattern of deep and elaborate processing in relation to age and experimental treatment. It was concluded that aging results in poor elaboration, especially in inefficient integration of word events with the context of presentation. (Author/CP)

Mechanism of Inflammation in Age-Related Macular Degeneration

Directory of Open Access Journals (Sweden)

Francesco Parmeggiani

2012-01-01

Full Text Available Age-related macular degeneration (AMD is a multifactorial disease that represents the most common cause of irreversible visual impairment among people over the age of 50 in Europe, the United States, and Australia, accounting for up to 50% of all cases of central blindness. Risk factors of AMD are heterogeneous, mainly including increasing age and different genetic predispositions, together with several environmental/epigenetic factors, that is, cigarette smoking, dietary habits, and phototoxic exposure. In the aging retina, free radicals and oxidized lipoproteins are considered to be major causes of tissue stress resulting in local triggers for parainflammation, a chronic status which contributes to initiation and/or progression of many human neurodegenerative diseases such as AMD. Experimental and clinical evidences strongly indicate the pathogenetic role of immunologic processes in AMD occurrence, consisting of production of inflammatory related molecules, recruitment of macrophages, complement activation, microglial activation and accumulation within those structures that compose an essential area of the retina known as macula lutea. This paper reviews some attractive aspects of the literature about the mechanisms of inflammation in AMD, especially focusing on those findings or arguments more directly translatable to improve the clinical management of patients with AMD and to prevent the severe vision loss caused by this disease.

Bioactive Nutrients and Nutrigenomics in Age-Related Diseases

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Tania Rescigno

2017-01-01

Full Text Available The increased life expectancy and the expansion of the elderly population are stimulating research into aging. Aging may be viewed as a multifactorial process that results from the interaction of genetic and environmental factors, which include lifestyle. Human molecular processes are influenced by physiological pathways as well as exogenous factors, which include the diet. Dietary components have substantive effects on metabolic health; for instance, bioactive molecules capable of selectively modulating specific metabolic pathways affect the development/progression of cardiovascular and neoplastic disease. As bioactive nutrients are increasingly identified, their clinical and molecular chemopreventive effects are being characterized and systematic analyses encompassing the “omics” technologies (transcriptomics, proteomics and metabolomics are being conducted to explore their action. The evolving field of molecular pathological epidemiology has unique strength to investigate the effects of dietary and lifestyle exposure on clinical outcomes. The mounting body of knowledge regarding diet-related health status and disease risk is expected to lead in the near future to the development of improved diagnostic procedures and therapeutic strategies targeting processes relevant to nutrition. The state of the art of aging and nutrigenomics research and the molecular mechanisms underlying the beneficial effects of bioactive nutrients on the main aging-related disorders are reviewed herein.

Mechanism of Inflammation in Age-Related Macular Degeneration

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Parmeggiani, Francesco; Romano, Mario R.; Costagliola, Ciro; Semeraro, Francesco; Incorvaia, Carlo; D'Angelo, Sergio; Perri, Paolo; De Palma, Paolo; De Nadai, Katia; Sebastiani, Adolfo

2012-01-01

Age-related macular degeneration (AMD) is a multifactorial disease that represents the most common cause of irreversible visual impairment among people over the age of 50 in Europe, the United States, and Australia, accounting for up to 50% of all cases of central blindness. Risk factors of AMD are heterogeneous, mainly including increasing age and different genetic predispositions, together with several environmental/epigenetic factors, that is, cigarette smoking, dietary habits, and phototoxic exposure. In the aging retina, free radicals and oxidized lipoproteins are considered to be major causes of tissue stress resulting in local triggers for parainflammation, a chronic status which contributes to initiation and/or progression of many human neurodegenerative diseases such as AMD. Experimental and clinical evidences strongly indicate the pathogenetic role of immunologic processes in AMD occurrence, consisting of production of inflammatory related molecules, recruitment of macrophages, complement activation, microglial activation and accumulation within those structures that compose an essential area of the retina known as macula lutea. This paper reviews some attractive aspects of the literature about the mechanisms of inflammation in AMD, especially focusing on those findings or arguments more directly translatable to improve the clinical management of patients with AMD and to prevent the severe vision loss caused by this disease. PMID:23209345

Developmental improvement and age-related decline in unfamiliar face matching.

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Megreya, Ahmed M; Bindemann, Markus

2015-01-01

Age-related changes have been documented widely in studies of face recognition and eyewitness identification. However, it is not clear whether these changes arise from general developmental differences in memory or occur specifically during the perceptual processing of faces. We report two experiments to track such perceptual changes using a 1-in- 10 (experiment 1) and 1-in-1 (experiment 2) matching task for unfamiliar faces. Both experiments showed improvements in face matching during childhood and adult-like accuracy levels by adolescence. In addition, face-matching performance declined in adults of the age of 65 years. These findings indicate that developmental improvements and aging-related differences in face processing arise from changes in the perceptual encoding of faces. A clear face inversion effect was also present in all age groups. This indicates that those age-related changes in face matching reflect a quantitative effect, whereby typical face processes are engaged but do not operate at the best-possible level. These data suggest that part of the problem of eyewitness identification in children and elderly persons might reflect impairments in the perceptual processing of unfamiliar faces.

Impact of age-related neuroglial cell responses on hippocampal deterioration

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Joseph O Ojo

2015-04-01

Full Text Available Aging is one of the greatest risk factors for the development of sporadic age-related neurodegenerative diseases and neuroinflammation is a common feature of this disease phenotype. In the immunoprivileged brain, neuroglial cells, which mediate neuroinflammatory responses, are influenced by the physiological factors in the microenvironment of the central nervous system (CNS. These physiological factors include but are not limited to cell-to-cell communication involving cell adhesion molecules, neuronal electrical activity and neurotransmitter and neuromodulator action. However, despite this dynamic control of neuroglial activity, in the healthy aged brain there is an alteration in the underlying neuroinflammatory response notably seen in the hippocampus, typified by astrocyte/microglia activation and increased pro-inflammatory cytokine production and signalling. Normally, these changes occur without any concurrent pathology, however, they can correlate with deteriorations in hippocampal or cognitive function. In this review we examine two important phenomenons, firstly the relationship between age-related brain deterioration (focusing on hippocampal function and underlying neuroglial response(s, and secondly how the latter affects molecular and cellular processes within the hippocampus that makes it vulnerable to age-related cognitive decline.

Pediatric health-related quality of life: a structural equation modeling approach.

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Ester Villalonga-Olives

Full Text Available OBJECTIVES: One of the most referenced theoretical frameworks to measure Health Related Quality of Life (HRQoL is the Wilson and Cleary framework. With some adaptions this framework has been validated in the adult population, but has not been tested in pediatric populations. Our goal was to empirically investigate it in children. METHODS: The contributory factors to Health Related Quality of Life that we included were symptom status (presence of chronic disease or hospitalizations, functional status (developmental status, developmental aspects of the individual (social-emotional behavior, and characteristics of the social environment (socioeconomic status and area of education. Structural equation modeling was used to assess the measurement structure of the model in 214 German children (3-5 years old participating in a follow-up study that investigates pediatric health outcomes. RESULTS: Model fit was χ2 = 5.5; df = 6; p = 0.48; SRMR  = 0.01. The variance explained of Health Related Quality of Life was 15%. Health Related Quality of Life was affected by the area education (i.e. where kindergartens were located and development status. Developmental status was affected by the area of education, socioeconomic status and individual behavior. Symptoms did not affect the model. CONCLUSIONS: The goodness of fit and the overall variance explained were good. However, the results between children' and adults' tests differed and denote a conceptual gap between adult and children measures. Indeed, there is a lot of variety in pediatric Health Related Quality of Life measures, which represents a lack of a common definition of pediatric Health Related Quality of Life. We recommend that researchers invest time in the development of pediatric Health Related Quality of Life theory and theory based evaluations.

Age-related inequalities in health and healthcare: the life stages approach.

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Jecker, Nancy S

2017-05-16

How should healthcare systems prepare to care for growing numbers and proportions of older people? Older people generally suffer worse health than younger people do. Should societies take steps to reduce age-related health inequalities? Some express concern that doing so would increase age-related inequalities in healthcare. This paper addresses this debate by (1) presenting an argument in support of three principles for distributing scarce resources between age groups; (2) framing these principles of age group justice in terms of life stages; and (3) indicating policy implications that merit further attention in light of rapidly aging societies. © 2017 John Wiley & Sons Ltd.

Incidence and progression rates of age-related maculopathy: the Rotterdam Study

NARCIS (Netherlands)

J.J.M. Willemse-Assink (Jacqueline); R. van Leeuwen (Redmer); R.C.W. Wolfs (Roger); J.R. Vingerling (Hans); Th. Stijnen (Theo); P.T.V.M. de Jong (Paulus); C.C.W. Klaver (Caroline); A. Hofman (Albert)

2001-01-01

textabstractPURPOSE: To describe the incidence rate of age-related macular degeneration (AMD) and the progression rates of early stages of age-related maculopathy (ARM), and to study the hierarchy of fundus features that determine progression. METHODS: A group of 4953 subjects

Complex centers of polynomial differential equations

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Mohamad Ali M. Alwash

2007-07-01

Full Text Available We present some results on the existence and nonexistence of centers for polynomial first order ordinary differential equations with complex coefficients. In particular, we show that binomial differential equations without linear terms do not have complex centers. Classes of polynomial differential equations, with more than two terms, are presented that do not have complex centers. We also study the relation between complex centers and the Pugh problem. An algorithm is described to solve the Pugh problem for equations without complex centers. The method of proof involves phase plane analysis of the polar equations and a local study of periodic solutions.

Oxidative stress participates in age-related changes in rat lumbar intervertebral discs.

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Hou, Gang; Lu, Huading; Chen, Mingjuan; Yao, Hui; Zhao, Huiqing

2014-01-01

Aging is a major factor associated with lumber intervertebral disc degeneration, and oxidative stress is known to play an essential role in the pathogenesis of many age-related diseases. In this study, we investigated oxidative stress in intervertebral discs of Wistar rats in three different age groups: youth, adult, and geriatric. Age-related intervertebral disc changes were examined by histological analysis. In addition, oxidative stress was evaluated by assessing nitric oxide (NO), superoxide dismutase (SOD), malondialdehyde (MDA), and advanced oxidation protein products (AOPPs). Intervertebral disc, but not serum, NO concentrations significantly differed between the three groups. Serum and intervertebral disc SOD activity gradually decreased with age. Furthermore, both serum and intervertebral disc MDA and AOPP levels gradually increased with age. Our studies suggest that oxidative stress is associated with age-related intervertebral disc changes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Partial differential equations of mathematical physics

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Sobolev, S L

1964-01-01

Partial Differential Equations of Mathematical Physics emphasizes the study of second-order partial differential equations of mathematical physics, which is deemed as the foundation of investigations into waves, heat conduction, hydrodynamics, and other physical problems. The book discusses in detail a wide spectrum of topics related to partial differential equations, such as the theories of sets and of Lebesgue integration, integral equations, Green's function, and the proof of the Fourier method. Theoretical physicists, experimental physicists, mathematicians engaged in pure and applied math

From the continuous PV to discrete Painleve equations

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Tokihiro, T.; Grammaticos, B.; Ramani, A.

2002-01-01

We study the discrete transformations that are associated with the auto-Baecklund of the (continuous) P V equation. We show that several two-parameter discrete Painleve equations can be obtained as contiguity relations of P V . Among them we find the asymmetric d-P II equation which is a well-known form of discrete P III . The relation between the ternary P I (previously obtained through the discrete dressing approach) and P V is also established. A new discrete Painleve equation is also derived. (author)

Aging-related episodic memory decline: are emotions the key?

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Kinugawa, Kiyoka; Schumm, Sophie; Pollina, Monica; Depre, Marion; Jungbluth, Carolin; Doulazmi, Mohamed; Sebban, Claude; Zlomuzica, Armin; Pietrowsky, Reinhard; Pause, Bettina; Mariani, Jean; Dere, Ekrem

2013-01-01

Episodic memory refers to the recollection of personal experiences that contain information on what has happened and also where and when these events took place. Episodic memory function is extremely sensitive to cerebral aging and neurodegerative diseases. We examined episodic memory performance with a novel test in young (N = 17, age: 21–45), middle-aged (N = 16, age: 48–62) and aged but otherwise healthy participants (N = 8, age: 71–83) along with measurements of trait and state anxiety. As expected we found significantly impaired episodic memory performance in the aged group as compared to the young group. The aged group also showed impaired working memory performance as well as significantly decreased levels of trait anxiety. No significant correlation between the total episodic memory and trait or state anxiety scores was found. The present results show an age-dependent episodic memory decline along with lower trait anxiety in the aged group. Yet, it still remains to be determined whether this difference in anxiety is related to the impaired episodic memory performance in the aged group. PMID:23378831

Neural Alterations in Acquired Age-Related Hearing Loss