Science.gov

Sample records for age related degradation

  1. Age related degradation in operating nuclear plants

    SciTech Connect

    Hermann, R.A.; Davis, J.A.; Banic, M.J.

    1995-12-01

    The aging issues being addressed for today`s operating commercial nuclear power plants encompass a wide spectrum of components, complexities, and reasons for concern. Issues include such things as the intergranular stress corrosion cracking (IGSCC) of boiling water reactor (BWR) internals, the degradation of pressurized water reactor (PWR) Alloy 600 components by primary water stress corrosion cracking (PWSCC) to those associated with significant portions of piping systems, such as service water systems. a discussion of the regulatory activity and action associated with the above issues is provided. Proactive NRC/Industry programs for inspection and repair or replacement of affected components are essential for continued operation of these nuclear reactors. These programs are also essential as licensees consider license extensions for their facilities. These plants are licensed for 40 years and can be granted an extension for an additional 20 years of operation if all of the NRC rules and regulations are met. Proper handling of potential age related problems will be a key consideration in the granting of a license extension.

  2. Age-related degradation of Westinghouse 480-volt circuit breakers

    SciTech Connect

    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.

  3. AGE-RELATED DEGRADATION OF NUCLEAR POWER PLANT STRUCTURES AND COMPONENTS.

    SciTech Connect

    BRAVERMAN,J.

    1999-03-29

    This paper summarizes and highlights the results of the initial phase of a research project on the assessment of aged and degraded structures and components important to the safe operation of nuclear power plants (NPPs). A review of age-related degradation of structures and passive components at NPPs was performed. Instances of age-related degradation have been collected and reviewed. Data were collected from plant generated documents such as Licensing Event Reports, NRC generic communications, NUREGs and industry reports. Applicable cases of degradation occurrences were reviewed and then entered into a computerized database. The results obtained from the review of degradation occurrences are summarized and discussed. Various trending analyses were performed to identify which structures and components are most affected, whether degradation occurrences are worsening, and what are the most common aging mechanisms. The paper also discusses potential aging issues and degradation-susceptible structures and passive components which would have the greatest impact on plant risk.

  4. Age-Related Degradation of Nuclear Power Plant Structures and Components

    SciTech Connect

    Braverman, J.; Chang, T.-Y.; Chokshi, N.; Hofmayer, C.; Morante, R.; Shteyngart, S.

    1999-03-29

    This paper summarizes and highlights the results of the initial phase of a research project on the assessment of aged and degraded structures and components important to the safe operation of nuclear power plants (NPPs). A review of age-related degradation of structures and passive components at NPPs was performed. Instances of age-related degradation have been collected and reviewed. Data were collected from plant generated documents such as Licensing Event Reports, NRC generic communications, NUREGs and industry reports. Applicable cases of degradation occurrences were reviewed and then entered into a computerized database. The results obtained from the review of degradation occurrences are summarized and discussed. Various trending analyses were performed to identify which structures and components are most affected, whether degradation occurrences are worsening, and what was the most common aging mechanisms. The paper also discusses potential aging issues and degradation-susceptible structures and passive components which would have the greatest impact on plant risk.

  5. Seismic Fragility Analysis of a Condensate Storage Tank with Age-Related Degradations

    SciTech Connect

    Nie, J.; Braverman, J.; Hofmayer, C; Choun, Y-S; Kim, MK; Choi, I-K

    2011-04-01

    The Korea Atomic Energy Research Institute (KAERI) is conducting a five-year research project to develop a realistic seismic risk evaluation system which includes the consideration of aging of structures and components in nuclear power plants (NPPs). The KAERI research project includes three specific areas that are essential to seismic probabilistic risk assessment (PRA): (1) probabilistic seismic hazard analysis, (2) seismic fragility analysis including the effects of aging, and (3) a plant seismic risk analysis. Since 2007, Brookhaven National Laboratory (BNL) has entered into a collaboration agreement with KAERI to support its development of seismic capability evaluation technology for degraded structures and components. The collaborative research effort is intended to continue over a five year period. The goal of this collaboration endeavor is to assist KAERI to develop seismic fragility analysis methods that consider the potential effects of age-related degradation of structures, systems, and components (SSCs). The research results of this multi-year collaboration will be utilized as input to seismic PRAs. This report describes the research effort performed by BNL for the Year 4 scope of work. This report was developed as an update to the Year 3 report by incorporating a major supplement to the Year 3 fragility analysis. In the Year 4 research scope, an additional study was carried out to consider an additional degradation scenario, in which the three basic degradation scenarios, i.e., degraded tank shell, degraded anchor bolts, and cracked anchorage concrete, are combined in a non-perfect correlation manner. A representative operational water level is used for this effort. Building on the same CDFM procedure implemented for the Year 3 Tasks, a simulation method was applied using optimum Latin Hypercube samples to characterize the deterioration behavior of the fragility capacity as a function of age-related degradations. The results are summarized in Section 5

  6. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans.

    PubMed

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition.

  7. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    SciTech Connect

    Nie,J.; Braverman, J.; Hofmayer, C.; Kim, M. K.; Choi, I-K.

    2009-04-27

    When performing seismic safety assessments of nuclear power plants (NPPs), the potential effects of age-related degradation on structures, systems, and components (SSCs) should be considered. To address the issue of aging degradation, the Korea Atomic Energy Research Institute (KAERI) has embarked on a five-year research project to develop a realistic seismic risk evaluation system which will include the consideration of aging of structures and components in NPPs. Three specific areas that are included in the KAERI research project, related to seismic probabilistic risk assessment (PRA), are probabilistic seismic hazard analysis, seismic fragility analysis including the effects of aging, and a plant seismic risk analysis. To support the development of seismic capability evaluation technology for degraded structures and components, KAERI entered into a collaboration agreement with Brookhaven National Laboratory (BNL) in 2007. The collaborative research effort is intended to continue over a five year period with the goal of developing seismic fragility analysis methods that consider the potential effects of age-related degradation of SSCs, and using these results as input to seismic PRAs. In the Year 1 scope of work BNL collected and reviewed degradation occurrences in US NPPs and identified important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. This information is presented in the Annual Report for the Year 1 Task, identified as BNL Report-81741-2008 and also designated as KAERI/RR-2931/2008. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, the report provides a description of U.S. current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. This report

  8. A complementary role of intracortical inhibition in age-related tactile degradation and its remodelling in humans

    PubMed Central

    Pleger, Burkhard; Wilimzig, Claudia; Nicolas, Volkmar; Kalisch, Tobias; Ragert, Patrick; Tegenthoff, Martin; Dinse, Hubert R.

    2016-01-01

    Many attempts are currently underway to restore age-related degraded perception, however, the link between restored perception and remodeled brain function remains elusive. To understand remodeling of age-related cortical reorganization we combined functional magnetic resonance imaging (fMRI) with assessments of tactile acuity, perceptual learning, and computational modeling. We show that aging leads to tactile degradation parallel to enhanced activity in somatosensory cortex. Using a neural field model we reconciled the empirical age-effects by weakening of cortical lateral inhibition. Using perceptual learning, we were able to partially restore tactile acuity, which however was not accompanied by the expected attenuation of cortical activity, but by a further enhancement. The neural field model reproduced these learning effects solely through a weakening of the amplitude of inhibition. These findings suggest that the restoration of age-related degraded tactile acuity on the cortical level is not achieved by re-strengthening lateral inhibition but by further weakening intracortical inhibition. PMID:27302219

  9. Effect of ozone on degradation and mRNA levels of Rubisco in relation to potato leaf age

    SciTech Connect

    Eckardt, N.A.; Pell, E.J. )

    1993-05-01

    Leaf senescence is characterized by loss of the major photosynthetic enzyme, Ribulose bisphosphate carboxylase (Rubisco). Exposure to ozone (O[sub 3]) is often associated with a premature decline in the quantity of this enzyme. Declines in Rubisco quantity could arise through inhibition of synthesis or enhancement of degradation. Several experiments were conducted to investigate the effect of O[sub 3] on these events in immature and mature leaves of potato. The effect of O[sub 3] on Rubisco synthesis was investigated indirectly by measuring the relative quantities of mRNA for the rubisco large (rbcL) and small (rbcS) subunits following a 5 hour exposure to 0.309 [mu]L L[sup [minus]1] O[sup 3] or charcoal-filtered air. O[sup 3] treatment was associated with a significant loss in rbcS mRNA in immature and mature potato leaves sampled immediately following the exposure. After the O[sup 3] exposure, a set of plants was placed in the dark at 30 C for two days. Levels of rbcS mRNA declined rapidly during the first twelve hours of dark incubation, thus declines in Rubisco quantity following two days of dark incubation were ascribed to degradation. Enhanced degradation due to O[sub 3] during the dark incubation was observed in the mature leaves, but not in the immature leaves. We conclude that O[sub 3] can cause both inhibited synthesis and enhanced degradation of Rubisco, and the response in dependent on leaf age.

  10. Review of Recent Aging-Related Degradation Occurrences of Structures and Passive Components in U.S. Nuclear Power Plants

    SciTech Connect

    Nie,J.; Braverman, J.; Hofmayer, C.; Choun, Y.-S.; Kim, M.K.; Choi, I.-K.

    2009-04-02

    The Korea Atomic Energy Research Institute (KAERI) and Brookhaven National Laboratory (BNL) are collaborating to develop seismic capability evaluation technology for degraded structures and passive components (SPCs) under a multi-year research agreement. To better understand the status and characteristics of degradation of SPCs in nuclear power plants (NPPs), the first step in this multi-year research effort was to identify and evaluate degradation occurrences of SPCs in U.S. NPPs. This was performed by reviewing recent publicly available information sources to identify and evaluate the characteristics of degradation occurrences and then comparing the information to the observations in the past. Ten categories of SPCs that are applicable to Korean NPPs were identified, comprising of anchorage, concrete, containment, exchanger, filter, piping system, reactor pressure vessel, structural steel, tank, and vessel. Software tools were developed to expedite the review process. Results from this review effort were compared to previous data in the literature to characterize the overall degradation trends.

  11. Degradation mechanisms and accelerated aging test design

    SciTech Connect

    Clough, R L; Gillen, K T

    1985-01-01

    The fundamental mechanisms underlying the chemical degradation of polymers can change as a function of environmental stress level. When this occurs, it greatly complicates any attempt to use accelerated tests for predicting long-term material degradation behaviors. Understanding how degradation mechanisms can change at different stress levels facilitates both the design and the interpretation of aging tests. Oxidative degradation is a predominant mechanism for many polymers exposed to a variety of different environments in the presence of air, and there are two mechanistic considerations which are widely applicable to material oxidation. One involves a physical process, oxygen diffusion, as a rate-limiting step. This mechanism can predominate at high stress levels. The second is a chemical process, the time-dependent decomposition of peroxide species. This leads to chain branching and can become a rate-controlling factor at lower stress levels involving time-scales applicable to use environments. The authors describe methods for identifying the operation of these mechanisms and illustrate the dramatic influence they can have on the degradation behaviors of a number of polymer types. Several commonly used approaches to accelerated aging tests are discussed in light of the behaviors which result from changes in degradation mechanisms. 9 references, 4 figures.

  12. Reliability Degradation Due to Stockpile Aging

    SciTech Connect

    Robinson, David G.

    1999-04-01

    The objective of this reseach is the investigation of alternative methods for characterizing the reliability of systems with time dependent failure modes associated with stockpile aging. Reference to 'reliability degradation' has, unfortunately, come to be associated with all types of aging analyes: both deterministic and stochastic. In this research, in keeping with the true theoretical definition, reliability is defined as a probabilistic description of system performance as a funtion of time. Traditional reliability methods used to characterize stockpile reliability depend on the collection of a large number of samples or observations. Clearly, after the experiments have been performed and the data has been collected, critical performance problems can be identified. A Major goal of this research is to identify existing methods and/or develop new mathematical techniques and computer analysis tools to anticipate stockpile problems before they become critical issues. One of the most popular methods for characterizing the reliability of components, particularly electronic components, assumes that failures occur in a completely random fashion, i.e. uniformly across time. This method is based primarily on the use of constant failure rates for the various elements that constitute the weapon system, i.e. the systems do not degrade while in storage. Experience has shown that predictions based upon this approach should be regarded with great skepticism since the relationship between the life predicted and the observed life has been difficult to validate. In addition to this fundamental problem, the approach does not recognize that there are time dependent material properties and variations associated with the manufacturing process and the operational environment. To appreciate the uncertainties in predicting system reliability a number of alternative methods are explored in this report. All of the methods are very different from those currently used to assess stockpile

  13. Perceptual restoration of degraded speech is preserved with advancing age.

    PubMed

    Saija, Jefta D; Akyürek, Elkan G; Andringa, Tjeerd C; Başkent, Deniz

    2014-02-01

    Cognitive skills, such as processing speed, memory functioning, and the ability to divide attention, are known to diminish with aging. The present study shows that, despite these changes, older adults can successfully compensate for degradations in speech perception. Critically, the older participants of this study were not pre-selected for high performance on cognitive tasks, but only screened for normal hearing. We measured the compensation for speech degradation using phonemic restoration, where intelligibility of degraded speech is enhanced using top-down repair mechanisms. Linguistic knowledge, Gestalt principles of perception, and expectations based on situational and linguistic context are used to effectively fill in the inaudible masked speech portions. A positive compensation effect was previously observed only with young normal hearing people, but not with older hearing-impaired populations, leaving the question whether the lack of compensation was due to aging or due to age-related hearing problems. Older participants in the present study showed poorer intelligibility of degraded speech than the younger group, as expected from previous reports of aging effects. However, in conditions that induce top-down restoration, a robust compensation was observed. Speech perception by the older group was enhanced, and the enhancement effect was similar to that observed with the younger group. This effect was even stronger with slowed-down speech, which gives more time for cognitive processing. Based on previous research, the likely explanations for these observations are that older adults can overcome age-related cognitive deterioration by relying on linguistic skills and vocabulary that they have accumulated over their lifetime. Alternatively, or simultaneously, they may use different cerebral activation patterns or exert more mental effort. This positive finding on top-down restoration skills by the older individuals suggests that new cognitive training methods

  14. Perceptual restoration of degraded speech is preserved with advancing age.

    PubMed

    Saija, Jefta D; Akyürek, Elkan G; Andringa, Tjeerd C; Başkent, Deniz

    2014-02-01

    Cognitive skills, such as processing speed, memory functioning, and the ability to divide attention, are known to diminish with aging. The present study shows that, despite these changes, older adults can successfully compensate for degradations in speech perception. Critically, the older participants of this study were not pre-selected for high performance on cognitive tasks, but only screened for normal hearing. We measured the compensation for speech degradation using phonemic restoration, where intelligibility of degraded speech is enhanced using top-down repair mechanisms. Linguistic knowledge, Gestalt principles of perception, and expectations based on situational and linguistic context are used to effectively fill in the inaudible masked speech portions. A positive compensation effect was previously observed only with young normal hearing people, but not with older hearing-impaired populations, leaving the question whether the lack of compensation was due to aging or due to age-related hearing problems. Older participants in the present study showed poorer intelligibility of degraded speech than the younger group, as expected from previous reports of aging effects. However, in conditions that induce top-down restoration, a robust compensation was observed. Speech perception by the older group was enhanced, and the enhancement effect was similar to that observed with the younger group. This effect was even stronger with slowed-down speech, which gives more time for cognitive processing. Based on previous research, the likely explanations for these observations are that older adults can overcome age-related cognitive deterioration by relying on linguistic skills and vocabulary that they have accumulated over their lifetime. Alternatively, or simultaneously, they may use different cerebral activation patterns or exert more mental effort. This positive finding on top-down restoration skills by the older individuals suggests that new cognitive training methods

  15. Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods. 1. Artificially aged model samples.

    PubMed

    Monico, Letizia; Van der Snickt, Geert; Janssens, Koen; De Nolf, Wout; Miliani, Costanza; Verbeeck, Johan; Tian, He; Tan, Haiyan; Dik, Joris; Radepont, Marie; Cotte, Marine

    2011-02-15

    On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO(4), PbCrO(4)·xPbSO(4), or PbCrO(4)·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1-3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr(2)O(3)·2H(2)O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr(2)(SO(4))(3)·H(2)O or (CH(3)CO(2))(7)Cr(3)(OH)(2) [chromium(III) acetate hydroxide], is likely.

  16. Depression in Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Casten, Robin; Rovner, Barry

    2008-01-01

    Age-related macular degeneration (AMD) is a major cause of disability in the elderly, substantially degrades the quality of their lives, and is a risk factor for depression. Rates of depression in AMD are substantially greater than those found in the general population of older people, and are on par with those of other chronic and disabling…

  17. Pressurized-water reactor internals aging degradation study. Phase 1

    SciTech Connect

    Luk, K.H.

    1993-09-01

    This report documents the results of a Phase I study on the effects of aging degradations on pr internals. Primary stressers for internals an generated by the primary coolant flow in the they include unsteady hydrodynamic forces and pump-generated pressure pulsations. Other stressors are applied loads, manufacturing processes, impurities in the coolant and exposures to fast neutron fluxes. A survey of reported aging-related failure information indicates that fatigue, stress corrosion cracking (SCC) and mechanical wear are the three major aging-related degradation mechanisms for PWR internals. Significant reported failures include thermal shield flow-induced vibration problems, SCC in guide tube support pins and core support structure bolts, fatigue-induced core baffle water-jet impingement problems and excess wear in flux thimbles. Many of the reported problems have been resolved by accepted engineering practices. Uncertainties remain in the assessment of long-term neutron irradiation effects and environmental factors in high-cycle fatigue failures. Reactor internals are examined by visual inspections and the technique is access limited. Improved inspection methods, especially one with an early failure detection capability, can enhance the safety and efficiency of reactor operations.

  18. Evaluation of aging degradation of structural components

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1992-03-01

    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center_dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  19. Evaluation of aging degradation of structural components

    SciTech Connect

    Chopra, O.K.; Shack, W.J.

    1992-03-01

    Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

  20. Effects of Age on Long Term Memory for Degraded Speech

    PubMed Central

    Thiel, Christiane M.; Özyurt, Jale; Nogueira, Waldo; Puschmann, Sebastian

    2016-01-01

    Prior research suggests that acoustical degradation impacts encoding of items into memory, especially in elderly subjects. We here aimed to investigate whether acoustically degraded items that are initially encoded into memory are more prone to forgetting as a function of age. Young and old participants were tested with a vocoded and unvocoded serial list learning task involving immediate and delayed free recall. We found that degraded auditory input increased forgetting of previously encoded items, especially in older participants. We further found that working memory capacity predicted forgetting of degraded information in young participants. In old participants, verbal IQ was the most important predictor for forgetting acoustically degraded information. Our data provide evidence that acoustically degraded information, even if encoded, is especially vulnerable to forgetting in old age. PMID:27708570

  1. Age, distribution, and formation of late cenozoic paleovalleys of the lower Colorado River and their relation to river aggradation and degradation

    USGS Publications Warehouse

    Howard, K.A.; Lundstrom, S.C.; Malmon, D.V.; Hook, S.J.

    2008-01-01

    Distinctive far-traveled fluvial sediment of the lower Colorado River fills 20 paleo-valleys now stranded by the river downstream of Grand Canyon as it crosses the Basin and Range Province. These sediments resulted from two or more aggradational epi sodes in Pliocene and Pleistocene times following initial incision during the early Pliocene. A review of the stratigraphic evidence of major swings in river elevation over the last 5 m.y. from alternating degradation and aggradation episodes establishes a framework for understanding the incision and filling of the paleovalleys. The paleo-valleys are found mostly along narrow bedrock canyon reaches of the river, where divides of bedrock or old deposits separate them from the modern river. The paleo-valleys are interpreted to have stemmed from periods of aggradation that filled and broadened the river valley, burying low uplands in the canyon reaches into which later channel positions were entrenched during subsequent degradation episodes. The aggradation-degradation cycles resulted in the stranding of incised river valleys that range in elevation from near the modern river to 350 m above it. ?? 2008 The Geological Society of America.

  2. Multiscale Concrete Modeling of Aging Degradation

    SciTech Connect

    Hammi, Yousseff; Gullett, Philipp; Horstemeyer, Mark F.

    2015-07-31

    In this work a numerical finite element framework is implemented to enable the integration of coupled multiscale and multiphysics transport processes. A User Element subroutine (UEL) in Abaqus is used to simultaneously solve stress equilibrium, heat conduction, and multiple diffusion equations for 2D and 3D linear and quadratic elements. Transport processes in concrete structures and their degradation mechanisms are presented along with the discretization of the governing equations. The multiphysics modeling framework is theoretically extended to the linear elastic fracture mechanics (LEFM) by introducing the eXtended Finite Element Method (XFEM) and based on the XFEM user element implementation of Giner et al. [2009]. A damage model that takes into account the damage contribution from the different degradation mechanisms is theoretically developed. The total contribution of damage is forwarded to a Multi-Stage Fatigue (MSF) model to enable the assessment of the fatigue life and the deterioration of reinforced concrete structures in a nuclear power plant. Finally, two examples are presented to illustrate the developed multiphysics user element implementation and the XFEM implementation of Giner et al. [2009].

  3. Age-related cataract.

    PubMed

    Asbell, Penny A; Dualan, Ivo; Mindel, Joel; Brocks, Dan; Ahmad, Mehdi; Epstein, Seth

    Cataract, opacification of the lens, is one of the commonest causes of loss of useful vision, with an estimated 16 million people worldwide affected. Several risk factors have been identified in addition to increasing age--genetic composition, exposure to ultraviolet light, and diabetes. However, no method to halt the formation of a cataractous lens has been shown to be effective. Nevertheless, advances in surgical removal of cataracts, including small-incision surgery, use of viscoelastics, and the development of intraocular lenses, have made treatment very effective and visual recovery rapid in most cases. Despite these advances, cataract continues to be a leading public-health issue that will grow in importance as the population increases and life expectancy is extended worldwide. PMID:15708105

  4. Final Report Inspection of Aged/Degraded Containments Program.

    SciTech Connect

    Naus, Dan J; Ellingwood, B R; Oland, C Barry

    2005-09-01

    The Inspection of Aged/Degraded Containments Program had primary objectives of (1) understanding the significant factors relating corrosion occurrence, efficacy of inspection, and structural capacity reduction of steel containments and liners of reinforced concrete containments; (2) providing the United States Nuclear Regulatory Commission (USNRC) reviewers a means of establishing current structural capacity margins or estimating future residual structural capacity margins for steel containments, and concrete containments as limited by liner integrity; (3) providing recommendations, as appropriate, on information to be requested of licensees for guidance that could be utilized by USNRC reviewers in assessing the seriousness of reported incidences of containment degradation; and (4) providing technical assistance to the USNRC (as requested) related to concrete technology. Primary program accomplishments have included development of a degradation assessment methodology; reviews of techniques and methods for inspection and repair of containment metallic pressure boundaries; evaluation of high-frequency acoustic imaging, magnetostrictive sensor, electromagnetic acoustic transducer, and multimode guided plate wave technologies for inspection of inaccessible regions of containment metallic pressure boundaries; development of a continuum damage mechanics-based approach for structural deterioration; establishment of a methodology for reliability-based condition assessments of steel containments and liners; and fragility assessments of steel containments with localized corrosion. In addition, data and information assembled under this program has been transferred to the technical community through review meetings and briefings, national and international conference participation, technical committee involvement, and publications of reports and journal articles. Appendix A provides a listing of program reports, papers, and publications; and Appendix B contains a listing of

  5. Confidant Relations of the Aged.

    ERIC Educational Resources Information Center

    Tigges, Leann M.; And Others

    The confidant relationship is a qualitatively distinct dimension of the emotional support system of the aged, yet the composition of the confidant network has been largely neglected in research on aging. Persons (N=940) 60 years of age and older were interviewed about their socio-environmental setting. From the enumeration of their relatives,…

  6. Boiling-Water Reactor internals aging degradation study. Phase 1

    SciTech Connect

    Luk, K.H.

    1993-09-01

    This report documents the results of an aging assessment study for boiling water reactor (BWR) internals. Major stressors for BWR internals are related to unsteady hydrodynamic forces generated by the primary coolant flow in the reactor vessel. Welding and cold-working, dissolved oxygen and impurities in the coolant, applied loads and exposures to fast neutron fluxes are other important stressors. Based on results of a component failure information survey, stress corrosion cracking (SCC) and fatigue are identified as the two major aging-related degradation mechanisms for BWR internals. Significant reported failures include SCC in jet-pump holddown beams, in-core neutron flux monitor dry tubes and core spray spargers. Fatigue failures were detected in feedwater spargers. The implementation of a plant Hydrogen Water Chemistry (HWC) program is considered as a promising method for controlling SCC problems in BWR. More operating data are needed to evaluate its effectiveness for internal components. Long-term fast neutron irradiation effects and high-cycle fatigue in a corrosive environment are uncertainty factors in the aging assessment process. BWR internals are examined by visual inspections and the method is access limited. The presence of a large water gap and an absence of ex-core neutron flux monitors may handicap the use of advanced inspection methods, such as neutron noise vibration measurements, for BWR.

  7. Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation

    PubMed Central

    van der Goot, Annemieke T.; Zhu, Wentao; Vázquez-Manrique, Rafael P.; Seinstra, Renée I.; Dettmer, Katja; Michels, Helen; Farina, Francesca; Krijnen, Jasper; Melki, Ronald; Buijsman, Rogier C.; Ruiz Silva, Mariana; Thijssen, Karen L.; Kema, Ido P.; Neri, Christian; Oefner, Peter J.; Nollen, Ellen A. A.

    2012-01-01

    Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer’s diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a metabolic regulator of age-related α-synuclein toxicity in a Caenorhabditis elegans model. Depletion of tdo-2 also suppresses toxicity of other heterologous aggregation-prone proteins, including amyloid-β and polyglutamine proteins, and endogenous metastable proteins that are sensors of normal protein homeostasis. This finding suggests that tdo-2 functions as a general regulator of protein homeostasis. Analysis of metabolite levels in C. elegans strains with mutations in enzymes that act downstream of tdo-2 indicates that this suppression of toxicity is independent of downstream metabolites in the kynurenine pathway. Depletion of tdo-2 increases tryptophan levels, and feeding worms with extra l-tryptophan also suppresses toxicity, suggesting that tdo-2 regulates proteotoxicity through tryptophan. Depletion of tdo-2 extends lifespan in these worms. Together, these results implicate tdo-2 as a metabolic switch of age-related protein homeostasis and lifespan. With TDO and Indoleamine 2,3-dioxygenase as evolutionarily conserved human orthologs of TDO-2, intervening with tryptophan metabolism may offer avenues to reducing proteotoxicity in aging and age-related diseases. PMID:22927396

  8. Aging degradation of cast stainless steel

    SciTech Connect

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the ..cap alpha..' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450/sup 0/C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450/sup 0/C. 18 refs., 13 figs.

  9. Ageing of GaN HEMT devices: which degradation indicators?

    NASA Astrophysics Data System (ADS)

    Divay, A.; Latry, O.; Duperrier, C.; Temcamani, F.

    2016-01-01

    A following of diverse degradation indicators during the ageing in operational conditions of AlGaN/GaN HEMTs (high electron mobility transistors) is proposed. Measurements of pulsed I-V, Schottky barrier height, RF output power and gate current versus output power during the early phase of the ageing test (2000 h on a 6000 h total) are presented. These preliminary results give insight on some of the principal degradation indicators that are interesting to follow during an ageing test close to operational conditions on such components.

  10. [Fibronectin, aging and related pathologies].

    PubMed

    Labat-Robert, J; Chevalier, X

    1991-01-01

    It could be demonstrated that plasma and tissue fibronectin (FN) increase with age. Some age dependent diseases as diabetes, osteoarthritis and Werner syndrome produce also an increase of tissue fibronectin biosynthesis. Plasma fibronectin decreases in diabetes and in breast cancer. Alternative splicing of the FN gene appears also to vary with age and in some related pathologies. Nutritional status and UV light also influence FN biosynthesis. It appears therefore that the determination of plasma FN and its isoforms as well as the study of tissue FN may be of interest for the study of chronological aging and related pathologies. PMID:1835421

  11. Nylon 6.6 accelerated aging studies : thermal-oxidative degradation and its interaction with hydrolysis.

    SciTech Connect

    Bernstein, Robert; Derzon, Dora Kay; Gillen, Kenneth T.

    2004-06-01

    Accelerated aging of Nylon 6.6 fibers used in parachutes has been conducted by following the tensile strength loss under both thermal-oxidative and 100% relative humidity conditions. Thermal-oxidative studies (air circulating ovens) were performed for time periods of weeks to years at temperatures ranging from 37 C to 138 C. Accelerated aging humidity experiments (100% RH) were performed under both an argon atmosphere to examine the 'pure' hydrolysis pathway, and under an oxygen atmosphere (oxygen partial pressure close to that occurring in air) to mimic true aging conditions. As expected the results indicated that degradation caused by humidity is much more important than thermal-oxidative degradation. Surprisingly when both oxygen and humidity were present the rate of degradation was dramatically enhanced relative to humidity aging in the absence of oxygen. This significant and previously unknown phenomena underscores the importance of careful accelerated aging that truly mimics real world storage conditions.

  12. Aging, frailty and age-related diseases.

    PubMed

    Fulop, T; Larbi, A; Witkowski, J M; McElhaney, J; Loeb, M; Mitnitski, A; Pawelec, G

    2010-10-01

    The concept of frailty as a medically distinct syndrome has evolved based on the clinical experience of geriatricians and is clinically well recognizable. Frailty is a nonspecific state of vulnerability, which reflects multisystem physiological change. These changes underlying frailty do not always achieve disease status, so some people, usually very elderly, are frail without a specific life threatening illness. Current thinking is that not only physical but also psychological, cognitive and social factors contribute to this syndrome and need to be taken into account in its definition and treatment. Together, these signs and symptoms seem to reflect a reduced functional reserve and consequent decrease in adaptation (resilience) to any sort of stressor and perhaps even in the absence of extrinsic stressors. The overall consequence is that frail elderly are at higher risk for accelerated physical and cognitive decline, disability and death. All these characteristics associated with frailty can easily be applied to the definition and characterization of the aging process per se and there is little consensus in the literature concerning the physiological/biological pathways associated with or determining frailty. It is probably true to say that a consensus view would implicate heightened chronic systemic inflammation as a major contributor to frailty. This review will focus on the relationship between aging, frailty and age-related diseases, and will highlight possible interventions to reduce the occurrence and effects of frailty in elderly people. PMID:20559726

  13. Degradation Characteristics of O-rings on Highly Aged GIS

    NASA Astrophysics Data System (ADS)

    Minagawa, Tadao; Nagao, Eiichi; Tsuchie, Ei; Yonezawa, Hiroshi; Takayama, Daisuke; Yamakawa, Yutaka

    Owing to increasing number of highly aged GIS, the investigation of the remaining lifetimes of those systems are becoming more important. Because a lot of O-rings are used in GIS, the study of degradation mechanism and lifetime estimation method of O-ring is essential. In this paper, the information about O-ring degradation mechanism is described, and the statistical method for estimating the remaining lifetime of O-ring is proposed. The degradation of O-ring is mainly subject to chemical reactions triggered by oxygen. Because there are many factors influencing those chemical reactions, the dispersion of degradation rates of O-rings in GIS is very large. Consequently the statistical analysis is one of the effective techniques for lifetime estimation of O-rings in GIS.

  14. Ultraviolet treatment overcomes time-related degrading bioactivity of titanium.

    PubMed

    Suzuki, Takeo; Hori, Norio; Att, Wael; Kubo, Katsutoshi; Iwasa, Fuminori; Ueno, Takeshi; Maeda, Hatsuhiko; Ogawa, Takahiro

    2009-12-01

    The shelf life of titanium implant products, that is, a possible time-related change of their bioactivity, has rarely been addressed. The objective of this study was to examine the bioactivity of newly processed and aged titanium surfaces and determine whether ultraviolet (UV) light treatment of the titanium surface restores the possible adverse effects of titanium aging. Titanium disks, either acid-etched or sandblasted, were used immediately after processing (fresh surface) or after storing in dark for 4 weeks (aged surface). Some disks were treated with UV light for 48 h after 4 weeks of storage. Albumin adsorbed to the aged surfaces was only 15% of that adsorbed to the fresh surfaces during 2-h incubation, whereas UV-treated aged surfaces adsorbed equivalent amount of albumin to that for the fresh surfaces. During 24-h incubation, the number of human mesenchymal stem cells attached to the aged surfaces was less than half of that for the fresh surfaces, whereas UV treatment of the aged surfaces increased the number three times. Proliferation, alkaline phosphatase activity, and calcium deposition of the cells were substantially lower on the aged surfaces than on the fresh surfaces, while those on the UV-treated aged surfaces were higher than on the fresh surfaces. The strength of bone-implant integration evaluated at week 2 of healing in a rat femur model was reduced to half after 4 weeks of titanium aging, whereas UV treatment of the aged implants increased the strength to the level equivalent to or even higher than the freshly prepared implants. Fresh and UV-treated aged surfaces were superhydrophilic, while the aged surface was hydrophobic. The data suggest that bioactivity of titanium surfaces degrades with time and that UV treatment of the aged surface increases the bioactivity over the level of the freshly prepared surface.

  15. Galactic Globular Cluster Relative Ages

    NASA Astrophysics Data System (ADS)

    De Angeli, Francesca; Piotto, Giampaolo; Cassisi, Santi; Busso, Giorgia; Recio-Blanco, Alejandra; Salaris, Maurizio; Aparicio, Antonio; Rosenberg, Alfred

    2005-07-01

    We present accurate relative ages for a sample of 55 Galactic globular clusters. The ages have been obtained by measuring the difference between the horizontal branch and the turnoff in two internally photometrically homogeneous databases. The mutual consistency of the two data sets has been assessed by comparing the ages of 16 globular clusters in common between the two databases. We have also investigated the consistency of our relative age determination within the recent stellar model framework. All clusters with [Fe/H]<-1.7 are found to be old and coeval, with the possible exception of two objects, which are marginally younger. The age dispersion for the metal-poor clusters is 0.6 Gyr (rms), consistent with a null age dispersion. Intermediate-metallicity clusters (-1.7<[Fe/H]<-0.8) are on average 1.5 Gyr younger than the metal-poor ones, with an age dispersion of 1.0 Gyr (rms) and a total age range of ~3 Gyr. About 15% of the intermediate-metallicity clusters are coeval with the oldest clusters. All the clusters with [Fe/H]>-0.8 are ~1 Gyr younger than the most metal-poor ones, with a relatively small age dispersion, although the metal-rich sample is still too small to allow firmer conclusions. There is no correlation of the cluster age with the galactocentric distance. We briefly discuss the implication of these observational results for the formation history of the Galaxy. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, and on observations made at the European Southern Observatory, La Silla, Chile, and with the Isaac Newton Group Telescopes.

  16. Scarp degraded by linear diffusion: inverse solution for age.

    USGS Publications Warehouse

    Andrews, D.J.; Hanks, T.C.

    1985-01-01

    Under the assumption that landforms unaffected by drainage channels are degraded according to the linear diffusion equation, a procedure is developed to invert a scarp profile to find its 'diffusion age'. The inverse procedure applied to synthetic data yields the following rules of thumb. Evidence of initial scarp shape has been lost when apparent age reaches twice its initial value. A scarp that appears to have been formed by one event may have been formed by two with an interval between them as large as apparent age. The simplicity of scarp profile measurement and this inversion makes profile analysis attractive. -from Authors

  17. Age-Related Macular Degeneration.

    PubMed

    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.

  18. Statistical physics of age related macular degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, H. E.

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer disease and Parkinson disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. We introduce a model of non-equilibrium cluster growth and aggregation that we have developed for studying the formation and growth of lipofuscin in the aging RPE. Our results agree with a linear growth of the number of lipofuscin granules with age. We apply the dynamic scaling approach to our model and find excellent data collapse for the cluster size distribution. An unusual feature of our model is that while small particles are removed from the RPE the larger ones become fixed and grow by aggregation.

  19. Lithium battery aging model based on Dakin's degradation approach

    NASA Astrophysics Data System (ADS)

    Baghdadi, Issam; Briat, Olivier; Delétage, Jean-Yves; Gyan, Philippe; Vinassa, Jean-Michel

    2016-09-01

    This paper proposes and validates a calendar and power cycling aging model for two different lithium battery technologies. The model development is based on previous SIMCAL and SIMSTOCK project data. In these previous projects, the effect of the battery state of charge, temperature and current magnitude on aging was studied on a large panel of different battery chemistries. In this work, data are analyzed using Dakin's degradation approach. In fact, the logarithms of battery capacity fade and the increase in resistance evolves linearly over aging. The slopes identified from straight lines correspond to battery aging rates. Thus, a battery aging rate expression function of aging factors was deduced and found to be governed by Eyring's law. The proposed model simulates the capacity fade and resistance increase as functions of the influencing aging factors. Its expansion using Taylor series was consistent with semi-empirical models based on the square root of time, which are widely studied in the literature. Finally, the influence of the current magnitude and temperature on aging was simulated. Interestingly, the aging rate highly increases with decreasing and increasing temperature for the ranges of -5 °C-25 °C and 25 °C-60 °C, respectively.

  20. Age-related atrial fibrosis.

    PubMed

    Gramley, Felix; Lorenzen, Johann; Knackstedt, Christian; Rana, Obaida R; Saygili, Erol; Frechen, Dirk; Stanzel, Sven; Pezzella, Francesco; Koellensperger, Eva; Weiss, Christian; Münzel, Thomas; Schauerte, Patrick

    2009-03-01

    Many age-related diseases are associated with, and may be promoted by, cardiac fibrosis. Transforming growth factor (TGF)-beta, hypoxia-induced factor (HIF), and the matrix metalloproteinase (MMP) system have been implicated in fibrogenesis. Thus, we investigated whether age is related to these systems and to atrial fibrosis. Right atrial appendages (RAA) obtained during heart surgery (n = 115) were grouped according to patients' age (<50 years, 51-60 years, 61-70 years, or >70 years). Echocardiographic ejection fractions (EF) and fibrosis using Sirius-red-stained histological sections were determined. TGF-beta was determined by quantitative RT-PCR and hypoxia-related factors [HIF1 alpha, the vascular endothelial growth factor (VEGF)-receptor, CD34 (a surrogate marker for microvessel density), the factor inhibiting HIF (FIH), and prolyl hydroxylase 3 (PHD 3)] were detected by immunostaining. MMP-2 and -9 activity were determined zymographically, and mRNA levels of their common tissue inhibitor TIMP-1 were determined by RT-PCR. Younger patients (<50 years) had significantly less fibrosis (10.1% +/- 4.4% vs 16.6% +/- 8.3%) than older individuals (>70 years). While HIF1 alpha, FIH, the VEGF-receptor, and CD34 were significantly elevated in the young, TGF-beta and PHD3 were suppressed in these patients. MMP-2 and -9 activity was found to be higher while TIMP-1 levels were lower in older patients. Statistical analysis proved age to be the only factor influencing fibrogenesis. With increasing age, RAAs develop significantly more fibrosis. An increase of fibrotic and decrease of hypoxic signalling and microvessel density, coupled with differential expression of MMPs and TIMP-1 favouring fibrosis may have helped promote atrial fibrogenesis. PMID:19234766

  1. [Presbycusis - Age Related Hearing Loss].

    PubMed

    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. PMID:27392191

  2. [Age-related changes of the brain].

    PubMed

    Paltsyn, A A; Komissarova, S V

    2015-01-01

    The first morphological signs of aging of the brain are found in the white matter already at a young age (20-40 years), and later (40-50 years) in a gray matter. After the 40-50 years appear and in subsequently are becoming more pronounced functional manifestations of morphological changes: the weakening of sensory-motor and cognitive abilities. While in principle this dynamic of age-related changes is inevitable, the rate of their development to a large extent determined by the genetic characteristics and lifestyle of the individual. According to modem concepts age-related changes in the number of nerve cells are different in different parts of the brain. However, these changes are not large and are not the main cause of senile decline brain. The main processes that contribute to the degradation of the brain develop as in the bodies of neurons and in neuropil. In the bodies of neurons--it is a damage (usually decrease) of the level of expression of many genes, and especially of the genes determining cell communication. In neuropil: reduction in the number of synapses and the strength of synaptic connections, reduction in the number of dendritic spines and axonal buttons, reduction in the number and thickness of the dendritic branches, demyelination of axons. As the result of these events, it becomes a violation of the rate of formation and rebuilding neuronal circuits. It is deplete associative ability, brain plasticity, and memory. PMID:27116888

  3. Birthdate and Performance: The Relative Age Effect.

    ERIC Educational Resources Information Center

    Barnsley, Roger H.

    The purpose of this paper is to consider the concept of "relative age" and to review recent research findings that have demonstrated that relative age is related to a variety of academic and athletic performance measures. The paper is divided into six parts: (1) the relative age concept; (2) relative age and achievement in sports; (3) relative age…

  4. [Age-related macular degeneration].

    PubMed

    Garcia Layana, A

    1998-01-01

    Age-related macular degeneration (ARMD) is the leading cause of blindness in the occidental world. Patients suffering this process have an important reduction on their quality of life being handicapped to read, to write, to recognise faces of their friends, or even to watch the television. One of the main problems of that disease is the absence of an effective treatment able to revert the process. Laser treatment is only useful in a limited number of patients, and even in these cases recurrent lesions are frequent. These facts and the progressive ageing of our society establish the ARMD as one of the biggest aim of medical investigations for the next century, and currently is focus of attention in the most industrialised countries. One of the most promising pieces of research is focused in the investigation of the risk factors associated with the age-related macular degeneration, in order to achieve a prophylactic treatment avoiding its appearance. Diet elements such as fat ingestion or reduced antioxidant intakes are being investigated as some of these factors, what open a new possibility for a prophylactic treatment. Finally, research is looking for new therapeutic modalities such as selective radiotherapy in order to improve or maintain the vision of these patients.

  5. Physics of Age Related Macular Degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon

    2009-11-01

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer's disease, and Parkinson's disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. In this talk I will discuss a model of non-equilibrium cluster growth that we have developed for studying the formation and growth of lipofuscin in AMD [K.I. Mazzitello, C.M. Arizmendi, Fereydoon Family, H. E. Grossniklaus, Physical Review E (2009)]. I will also present an overview of our theoretical and computational efforts in modeling some other aspects of the physics of AMD, including CNV and the breakdown of Bruch's membrane [Ongoing collaboration with Abbas Shirinifard and James A. Glazier, Biocomplexity Institute and Department of Physics, Indiana University, Y. Jiang, Los Alamos, and Hans E. Grossniklaus, Department of Ophthalmology, Emory University].

  6. Medical bioremediation of age-related diseases

    PubMed Central

    Mathieu, Jacques M; Schloendorn, John; Rittmann, Bruce E; Alvarez, Pedro JJ

    2009-01-01

    Catabolic insufficiency in humans leads to the gradual accumulation of a number of pathogenic compounds associated with age-related diseases, including atherosclerosis, Alzheimer's disease, and macular degeneration. Removal of these compounds is a widely researched therapeutic option, but the use of antibodies and endogenous human enzymes has failed to produce effective treatments, and may pose risks to cellular homeostasis. Another alternative is "medical bioremediation," the use of microbial enzymes to augment missing catabolic functions. The microbial genetic diversity in most natural environments provides a resource that can be mined for enzymes capable of degrading just about any energy-rich organic compound. This review discusses targets for biodegradation, the identification of candidate microbial enzymes, and enzyme-delivery methods. PMID:19358742

  7. HYDRIDE-RELATED DEGRADATION OF SNF CLADDING UNDER REPOSITORY CONDITIONS

    SciTech Connect

    K. McCoy

    2000-12-12

    The purpose and scope of this analysis/model report is to analyze the degradation of commercial spent nuclear fuel (CSNF) cladding under repository conditions by the hydride-related metallurgical processes, such as delayed hydride cracking (DHC), hydride reorientation and hydrogen embrittlement, thereby providing a better understanding of the degradation process and clarifying which aspects of the process are known and which need further evaluation and investigation. The intended use is as an input to a more general analysis of cladding degradation.

  8. Restricting the ageing degradation of the mechanical properties of gamma irradiated UHMWPE using MWCNTs.

    PubMed

    Rama Sreekanth, P S; Kanagaraj, S

    2013-05-01

    Property degradation of the medical grade polymers after gamma irradiation is the primary concern that limits longevity of them. Though the conventional antioxidant material helps to reduce the degradation but it limits the degree of crosslinking of the polymer. The objective of the present work is to study the influence of multi walled carbon nanotubes (MWCNTs) on restricting the degradation of mechanical properties of medical grade ultra high molecular weight polyethylene (UHMWPE) after its irradiation. UHMWPE was reinforced by chemically treated MWCNTs at different concentrations such as 0.5, 1.0, 1.5, and 2.0 wt%. The test samples were then subjected to Co⁶⁰ gamma irradiation with an integral dose of 25, 50, 75 and 100 kGy in air. The mechanical properties of irradiated samples were evaluated within 10 days, 60 and 120 days after irradiation. It was observed that the mechanical properties of virgin UHMWPE and nanocomposites were enhanced immediately after irradiation but they were found to be reduced at later stages. It was also observed that the presence of MWCNTs limited the ageing degradation of the mechanical properties of UHMWPE. Raman spectroscopic and TEM studies confirmed the formation of irradiation induced defects on the MWCNTs. Electron spin resonance studies showed that the relative radical intensity of virgin UHWMPE was reduced significantly with an increase of MWCNTs concentration confirming the radical scavenging ability of them. It is concluded that MWCNTs restricted the ageing degradation of irradiated UHMWPE.

  9. Changes in Structural-Mechanical Properties and Degradability of Collagen during Aging-associated Modifications.

    PubMed

    Panwar, Preety; Lamour, Guillaume; Mackenzie, Neil C W; Yang, Heejae; Ko, Frank; Li, Hongbin; Brömme, Dieter

    2015-09-18

    During aging, changes occur in the collagen network that contribute to various pathological phenotypes in the skeletal, vascular, and pulmonary systems. The aim of this study was to investigate the consequences of age-related modifications on the mechanical stability and in vitro proteolytic degradation of type I collagen. Analyzing mouse tail and bovine bone collagen, we found that collagen at both fibril and fiber levels varies in rigidity and Young's modulus due to different physiological changes, which correlate with changes in cathepsin K (CatK)-mediated degradation. A decreased susceptibility to CatK-mediated hydrolysis of fibrillar collagen was observed following mineralization and advanced glycation end product-associated modification. However, aging of bone increased CatK-mediated osteoclastic resorption by ∼27%, and negligible resorption was observed when osteoclasts were cultured on mineral-deficient bone. We observed significant differences in the excavations generated by osteoclasts and C-terminal telopeptide release during bone resorption under distinct conditions. Our data indicate that modification of collagen compromises its biomechanical integrity and affects CatK-mediated degradation both in bone and tissue, thus contributing to our understanding of extracellular matrix aging.

  10. Changes in Structural-Mechanical Properties and Degradability of Collagen during Aging-associated Modifications*

    PubMed Central

    Panwar, Preety; Lamour, Guillaume; Mackenzie, Neil C. W.; Yang, Heejae; Ko, Frank; Li, Hongbin; Brömme, Dieter

    2015-01-01

    During aging, changes occur in the collagen network that contribute to various pathological phenotypes in the skeletal, vascular, and pulmonary systems. The aim of this study was to investigate the consequences of age-related modifications on the mechanical stability and in vitro proteolytic degradation of type I collagen. Analyzing mouse tail and bovine bone collagen, we found that collagen at both fibril and fiber levels varies in rigidity and Young's modulus due to different physiological changes, which correlate with changes in cathepsin K (CatK)-mediated degradation. A decreased susceptibility to CatK-mediated hydrolysis of fibrillar collagen was observed following mineralization and advanced glycation end product-associated modification. However, aging of bone increased CatK-mediated osteoclastic resorption by ∼27%, and negligible resorption was observed when osteoclasts were cultured on mineral-deficient bone. We observed significant differences in the excavations generated by osteoclasts and C-terminal telopeptide release during bone resorption under distinct conditions. Our data indicate that modification of collagen compromises its biomechanical integrity and affects CatK-mediated degradation both in bone and tissue, thus contributing to our understanding of extracellular matrix aging. PMID:26224630

  11. Product analysis for polyethylene degradation by radiation and thermal ageing

    NASA Astrophysics Data System (ADS)

    Sugimoto, Masaki; Shimada, Akihiko; Kudoh, Hisaaki; Tamura, Kiyotoshi; Seguchi, Tadao

    2013-01-01

    The oxidation products in crosslinked polyethylene for cable insulation formed during thermal and radiation ageing were analyzed by FTIR-ATR. The products were composed of carboxylic acid, carboxylic ester, and carboxylic anhydride for all ageing conditions. The relative yields of carboxylic ester and carboxylic anhydride increased with an increase of temperature for radiation and thermal ageing. The carboxylic acid was the primary oxidation product and the ester and anhydride were secondary products formed by the thermally induced reactions of the carboxylic acids. The carboxylic acid could be produced by chain scission at any temperature followed by the oxidation of the free radicals formed in the polyethylene. The results of the analysis led to formulation of a new oxidation mechanism which was different from the chain reactions via peroxy radicals and peroxides.

  12. Pathophysiology of ageing, longevity and age related diseases

    PubMed Central

    Bürkle, Alexander; Caselli, Graziella; Franceschi, Claudio; Mariani, Erminia; Sansoni, Paolo; Santoni, Angela; Vecchio, Giancarlo; Witkowski, Jacek M; Caruso, Calogero

    2007-01-01

    On April 18, 2007 an international meeting on Pathophysiology of Ageing, Longevity and Age-Related Diseases was held in Palermo, Italy. Several interesting topics on Cancer, Immunosenescence, Age-related inflammatory diseases and longevity were discussed. In this report we summarize the most important issues. However, ageing must be considered an unavoidable end point of the life history of each individual, nevertheless the increasing knowledge on ageing mechanisms, allows envisaging many different strategies to cope with, and delay it. So, a better understanding of pathophysiology of ageing and age-related disease is essential for giving everybody a reasonable chance for living a long and enjoyable final part of the life. PMID:17683521

  13. Overcoming Age-Related Differences

    ERIC Educational Resources Information Center

    Agullo, Gloria Luque

    2006-01-01

    One of the most controversial issues in foreign language (FL) teaching is the age at which language learning should start. Nowadays it is recognized that in second language contexts maturational constraints make an early start advisable, but there is still disagreement regarding the problem of when to start or the best way to learn in foreign…

  14. Analyses of component degradation to evaluate maintenance effectiveness and aging effects

    SciTech Connect

    Samanta, P.K.; Hsu, F.; Subudhi, M. ); Vesely, W.E. )

    1991-01-01

    This paper describes degradation modeling, an approach for analyzing degradation and failure of components to understand the aging process of components. As used in our study, degradation modeling is the analysis of information on degradation of components for developing models of the degradation process and its implications. This modeling focuses on the analysis of the times of degradations of components, to model how the rate of degradation changes with the age of the component. With this methodology we also determine the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of degradation rates of components and failure rates of components from plant-specific data. The statistical techniques allow aging trends to be identified in the degradation data and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends. 2 refs., 8 figs., 1 tab.

  15. Nutrition and age-related eye diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vision loss among the elderly is an important health problem. Approximately one person in three has some form of vision-reducing eye disease by the age of 65 [1]. Age-related cataract, age-related macular degeneration (AMD), diabetic retinopathy and glaucoma are the major diseases resulting in visu...

  16. Oxidative degradation in highly cross-linked and conventional polyethylene after 2 years of real-time shelf aging.

    PubMed

    Willie, Bettina M; Bloebaum, Roy D; Ashrafi, Shadi; Dearden, Colette; Steffensen, Trina; Hofmann, Aaron A

    2006-04-01

    Previous studies have reported oxidative degradation of conventional polyethylene (PE) components during shelf aging, following radiation. However, no studies have yet reported data concerning the effect of real-time shelf aging in the manufacturer's packaging on the oxidative degradation of commercially available highly cross-linking PE components. The null hypothesis tested was that in either highly cross-linked or conventional PE acetabular components there would be no significant difference in the amount of oxidative degradation between time zero PE liners and PE liners that had been real-time shelf aged for 2 years in their respective packaging. The results of the study indicated that after 2 years of real-time shelf aging, negligible oxidative degradation occurred with minimal changes in oxidation index, density, and percent crystallinity in commercially available highly cross-linked and conventional PE acetabular liners. These data suggested that oxidative degradation was not a clinical issue in the highly cross-linked and conventional PE components examined after 2 years of real-time shelf aging. It is likely that current manufacturing and packaging technologies have limited the previous clinical concerns related to oxidative degradation during shelf aging of highly cross-linked and conventional PE components.

  17. Telomere length variations in aging and age-related diseases.

    PubMed

    Rizvi, Saliha; Raza, Syed Tasleem; Mahdi, Farzana

    2014-01-01

    Telomeres are gene sequences present at chromosomal ends and are responsible for maintaining genome integrity. Telomere length is maximum at birth and decreases progressively with advancing age and thus is considered as a biomarker of chronological aging. This age associated decrease in the length of telomere is linked to various ageing associated diseases like diabetes, hypertension, Alzheimer's disease, cancer etc. and their associated complications. Telomere length is a result of combined effect of oxidative stress, inflammation and repeated cell replication on it, and thus forming an association between telomere length and chronological aging and related diseases. Thus, decrease in telomere length was found to be important in determining both, the variations in longevity and age-related diseases in an individual. Ongoing and progressive research in the field of telomere length dynamics has proved that aging and age-related diseases apart from having a synergistic effect on telomere length were also found to effect telomere length independently also. Here a short description about telomere length variations and its association with human aging and age-related diseases is reviewed.

  18. Ethylene propylene cable degradation during LOCA research tests: tensile properties at the completion of accelerated aging

    SciTech Connect

    Bustard, L.D.

    1982-05-01

    Six ethylene-propylene rubber (EPR) insulation materials were aged at elevated temperature and radiation stress exposures common in cable LOCA qualification tests. Material samples were subjected to various simultaneous and sequential aging simulations in preparation for accident environmental exposures. Tensile properties subsequent to the aging exposure sequences are reported. The tensile properties of some, but not all, specimens were sensitive to the order of radiation and elevated temperature stress exposure. Other specimens showed more severe degradation when simultaneously exposed to radiation and elevated temperature as opposed to the sequential exposure to the same stresses. Results illustrate the difficulty in defining a single test procedure for nuclear safety-related qualification of EPR elastomers. A common worst-case sequential aging sequence could not be identified.

  19. LWR Sustainability: Assessment of Aging of Nuclear Power Plant Safety Related Concrete Strutures

    SciTech Connect

    Graves III, Herman; Naus, Dan J

    2013-01-01

    Current regulatory testing and inspection requirements are reviewed and a summary of degradation experience is presented. Techniques commonly used to inspect NPP concrete structures to assess and quantify age-related degradation are summarized. An approach for conduct of condition assessments of structures in NPPs is presented. Criteria, based primarily on visual indications, are provided for use in classification and assessment of concrete degradation. Materials and techniques for repair of degraded structures are generally discussed.

  20. Long noncoding RNAs in aging and age-related diseases.

    PubMed

    Kour, Sukhleen; Rath, Pramod C

    2016-03-01

    Aging is the universal, intrinsic, genetically-controlled, evolutionarily-conserved and time-dependent intricate biological process characterised by the cumulative decline in the physiological functions and their coordination in an organism after the attainment of adulthood resulting in the imbalance of neurological, immunological and metabolic functions of the body. Various biological processes and mechanisms along with altered levels of mRNAs and proteins have been reported to be involved in the progression of aging. It is one of the major risk factors in the patho-physiology of various diseases and disorders. Recently, the discovery of pervasive transcription of a vast pool of heterogeneous regulatory noncoding RNAs (ncRNAs), including small ncRNAs (sncRNAs) and long ncRNAs (lncRNAs), in the mammalian genome have provided an alternative way to study and explore the missing links in the aging process, its mechanism(s) and related diseases in a whole new dimension. The involvement of small noncoding RNAs in aging and age-related diseases have been extensively studied and recently reviewed. However, lncRNAs, whose function is far less explored in relation to aging, have emerged as a class of major regulators of genomic functions. Here, we have described some examples of known as well as novel lncRNAs that have been implicated in the progression of the aging process and age-related diseases. This may further stimulate research on noncoding RNAs and the aging process.

  1. Long noncoding RNAs in aging and age-related diseases.

    PubMed

    Kour, Sukhleen; Rath, Pramod C

    2016-03-01

    Aging is the universal, intrinsic, genetically-controlled, evolutionarily-conserved and time-dependent intricate biological process characterised by the cumulative decline in the physiological functions and their coordination in an organism after the attainment of adulthood resulting in the imbalance of neurological, immunological and metabolic functions of the body. Various biological processes and mechanisms along with altered levels of mRNAs and proteins have been reported to be involved in the progression of aging. It is one of the major risk factors in the patho-physiology of various diseases and disorders. Recently, the discovery of pervasive transcription of a vast pool of heterogeneous regulatory noncoding RNAs (ncRNAs), including small ncRNAs (sncRNAs) and long ncRNAs (lncRNAs), in the mammalian genome have provided an alternative way to study and explore the missing links in the aging process, its mechanism(s) and related diseases in a whole new dimension. The involvement of small noncoding RNAs in aging and age-related diseases have been extensively studied and recently reviewed. However, lncRNAs, whose function is far less explored in relation to aging, have emerged as a class of major regulators of genomic functions. Here, we have described some examples of known as well as novel lncRNAs that have been implicated in the progression of the aging process and age-related diseases. This may further stimulate research on noncoding RNAs and the aging process. PMID:26655093

  2. Age Related Changes in Preventive Health Behavior.

    ERIC Educational Resources Information Center

    Leventhal, Elaine A.; And Others

    Health behavior may be influenced by age, beliefs, and symptomatology. To examine age-related health beliefs and behaviors with respect to six diseases (the common cold, colon-rectal cancer, lung cancer, heart attack, high blood pressure, and senility), 396 adults (196 males, 200 females) divided into three age groups completed a questionnaire…

  3. Age-related aspects of addiction

    PubMed Central

    Koechl, Birgit; Unger, Annemarie; Fischer, Gabriele

    2013-01-01

    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. Research in the increasingly aging population needs to include an age- and gender-sensitive approach. PMID:22722821

  4. The mitochondrial theory of aging: do damaged mitochondria accumulate by delayed degradation?

    PubMed

    Kowald, A

    1999-08-01

    The mitochondrial theory of aging states that the slow accumulation of impaired mitochondria is the driving force of the aging process. In recent years, this theory has gained new support with the discovery of age-related mitochondrial DNA deletions. However, the underlying mechanism of the accumulation of defective mitochondria remained unclear. This has changed recently with the proposal of de Grey that damaged mitochondria have a decreased degradation rate. The resulting increase in biological half-life would be a strong selection advantage leading to the accumulation of defective mitochondria. In this article, I summarize current ideas on how damaged organelles can build up in a cell as well as the shortcomings of these ideas. Then the new hypothesis and its justification are described. It appears that de Grey's hypothesis is a very promising concept that elegantly solves inconsistencies of current models and is in accordance with experimental findings. PMID:10530786

  5. Immunology of age-related macular degeneration

    PubMed Central

    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

  6. Consequences of Age-Related Cognitive Declines

    PubMed Central

    Salthouse, Timothy

    2013-01-01

    Adult age differences in a variety of cognitive abilities are well documented, and many of those abilities have been found to be related to success in the workplace and in everyday life. However, increased age is seldom associated with lower levels of real-world functioning, and the reasons for this lab-life discrepancy are not well understood. This article briefly reviews research concerned with relations of age to cognition, relations of cognition to successful functioning outside the laboratory, and relations of age to measures of work performance and achievement. The final section discusses several possible explanations for why there are often little or no consequences of age-related cognitive declines in everyday functioning. PMID:21740223

  7. Latent Fingermark Aging Patterns (Part II): Color Contrast Between Ridges and Furrows as One Indicator of Degradation.

    PubMed

    De Alcaraz-Fossoul, Josep; Barrot Feixat, Carme; Tasker, Jack; McGarr, Luke; Stow, Karen; Carreras-Marin, Clara; Turbany Oset, Jaume; Gené Badia, Manel

    2016-07-01

    Currently, no established methodology exists to determine degradation patterns of latent fingermarks by visual means. This article is the second in a series of reports exploring quantifiable degradation-related parameters, which focuses on color contrast changes between fingermark ridges and furrows over time. Experiment variables included type of secretion (eccrine and sebaceous), substrate (glass and plastic), and exposure to natural light (dark, shade, and direct light). Fingermarks were sequentially visualized with titanium dioxide powder and photographed. Image histogram profiles were evaluated and combined with statistical analysis of color data values. Results indicate that sebaceous depositions on glass were generally less degraded by the effect of environmental conditions compared with those on plastic. In addition, aging in darkness was not always the best condition for preservation, and direct exposure to light seemed to inhibit visual degradation under certain conditions. Overall, the technique provided sufficient sensitivity to discern degradation patterns of fingermarks. PMID:27364272

  8. Latent Fingermark Aging Patterns (Part II): Color Contrast Between Ridges and Furrows as One Indicator of Degradation.

    PubMed

    De Alcaraz-Fossoul, Josep; Barrot Feixat, Carme; Tasker, Jack; McGarr, Luke; Stow, Karen; Carreras-Marin, Clara; Turbany Oset, Jaume; Gené Badia, Manel

    2016-07-01

    Currently, no established methodology exists to determine degradation patterns of latent fingermarks by visual means. This article is the second in a series of reports exploring quantifiable degradation-related parameters, which focuses on color contrast changes between fingermark ridges and furrows over time. Experiment variables included type of secretion (eccrine and sebaceous), substrate (glass and plastic), and exposure to natural light (dark, shade, and direct light). Fingermarks were sequentially visualized with titanium dioxide powder and photographed. Image histogram profiles were evaluated and combined with statistical analysis of color data values. Results indicate that sebaceous depositions on glass were generally less degraded by the effect of environmental conditions compared with those on plastic. In addition, aging in darkness was not always the best condition for preservation, and direct exposure to light seemed to inhibit visual degradation under certain conditions. Overall, the technique provided sufficient sensitivity to discern degradation patterns of fingermarks.

  9. Age-related preferences and age weighting health benefits.

    PubMed

    Tsuchiya, A

    1999-01-01

    This paper deals with the relevance of age in the paradigm of quality adjusted life years (QALYs). The first section outlines two rationales for incorporating age weights into QALYs. One of them is based on efficiency concerns; and the other on equity concerns. Both of these are theoretical constructs. The main purpose of this paper is to examine the extent of published empirical support for such age weighting. The second section is a brief survey of nine empirical studies that elicited age-related preferences from the general public. Six of these quantified the strength of the preferences, and these are discussed in more detail in the third section. The analysis distinguishes three kinds of age-related preference: productivity ageism, utilitarian ageism and egalitarian ageism. The relationship between them and their relevance to the two different rationales for age weighting are then explored. It is concluded that, although there is strong prima facie evidence of public support for both types of age weighting, the empirical evidence to support any particular set of weights is at present weak. PMID:10048783

  10. Identification of age degradation in EPROM chips using infrared thermography

    NASA Astrophysics Data System (ADS)

    Allred, Lloyd G.

    1998-03-01

    In a recent upgrade of the digital flight control computer for the F-16, there was serious consternation expressed about the quality of the soldering repair process. Dozens of circuit cards failed to function after the upgrade, even though all of these cards operated correctly before the modifications. The shop called for the use of the IR camera to assist in diagnosing and repairing these cards. What the Neural Radiant Energy Detection found was faulty and marginal chips.Of particular interest was the presence of degraded EPROM chips on the Program Memory cards. While it is known that EPROMs have a limited life cycle, the failure has been further characterized. Thermography provides a quantification of the degradation in thermal performance as the EPROMs are reused. Pristine EPROM chips have a rise rate of about 0.008 degrees C/sec. When the heat rates exceed 0.021 degrees C/sec, the EPROM chips will not accept a program. Some of the chips exhibited heat rates exceeding 0.1 degrees C/sec. Some chips with degradation of 0.018 degrees C/sec would accept a program, but fail other functional tests. What is clear from these results is that IR thermography can be used to identify degrading EPROM chips for replacement before failures become immanent.

  11. Incentive relativity in middle aged rats.

    PubMed

    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.

  12. X-82 to Treat Age-related Macular Degeneration

    ClinicalTrials.gov

    2016-08-16

    Age-Related Macular Degeneration (AMD); Macular Degeneration; Exudative Age-related Macular Degeneration; AMD; Macular Degeneration, Age-related, 10; Eye Diseases; Retinal Degeneration; Retinal Diseases

  13. Curcumin, inflammation, ageing and age-related diseases.

    PubMed

    Sikora, E; Scapagnini, Giovanni; Barbagallo, Mario

    2010-01-17

    A Symposium regarding the Pathophysiology of Successful and Unsuccessful Ageing was held in Palermo, Italy between April 7 and 8th 2009. Here the lecture by Sikora with some input from the chairpersons Scapagnini and Barbagallo is summarized. Ageing is manifested by the decreasing health status and increasing probability to acquire age-related disease such as cancer, Alzheimer's disease, atherosclerosis, metabolic disorders and others. They are likely caused by low grade inflammation driven by oxygen stress and manifested by the increased level of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-alpha, encoded by genes activated by the transcription factor NF-kappaB. It is believed that ageing is plastic and can be slowed down by caloric restriction as well as by some nutraceuticals. Accordingly, slowing down ageing and postponing the onset of age-related diseases might be achieved by blocking the NF-kappaB-dependent inflammation. In this review we consider the possibility of the spice curcumin, a powerful antioxidant and anti-inflammatory agent possibly capable of improving the health status of the elderly.

  14. Ages estimated from a diffusion equation model for scarp degradation

    USGS Publications Warehouse

    Colman, Steven M.; Watson, K.E.N.

    1983-01-01

    The diffusion equation derived from the continuity equation for hillslopes is applied to scarp erosion in unconsolidated materials. Solutions to this equation allow direct calculation of the product of the rate coefficient and the age of the scarp from measurements of scarp morphology. Where the rate coefficient can be estimated or can be derived from scarps of known age, this method allows direct calculation of unknown ages of scarps.

  15. Translational strategies in aging and age-related disease.

    PubMed

    Armanios, Mary; de Cabo, Rafael; Mannick, Joan; Partridge, Linda; van Deursen, Jan; Villeda, Saul

    2015-12-01

    Aging is a risk factor for several of the world's most prevalent diseases, including neurodegenerative disorders, cancer, cardiovascular disease and metabolic disease. Although our understanding of the molecular pathways that contribute to the aging process and age-related disease is progressing through the use of model organisms, how to apply this knowledge in the clinic is less clear. In September, Nature Medicine, in collaboration with the Volkswagen Foundation, hosted a conference at the beautiful Herrenhausen Palace in Hannover, Germany with the goal of broadening our understanding of the aging process and its meaning as a 'risk factor' in disease. Here, several of the speakers at that conference answer questions posed by Nature Medicine.

  16. Translational strategies in aging and age-related disease.

    PubMed

    Armanios, Mary; de Cabo, Rafael; Mannick, Joan; Partridge, Linda; van Deursen, Jan; Villeda, Saul

    2015-12-01

    Aging is a risk factor for several of the world's most prevalent diseases, including neurodegenerative disorders, cancer, cardiovascular disease and metabolic disease. Although our understanding of the molecular pathways that contribute to the aging process and age-related disease is progressing through the use of model organisms, how to apply this knowledge in the clinic is less clear. In September, Nature Medicine, in collaboration with the Volkswagen Foundation, hosted a conference at the beautiful Herrenhausen Palace in Hannover, Germany with the goal of broadening our understanding of the aging process and its meaning as a 'risk factor' in disease. Here, several of the speakers at that conference answer questions posed by Nature Medicine. PMID:26646495

  17. Accelerated aging studies of UHMWPE. II. Virgin UHMWPE is not immune to oxidative degradation.

    PubMed

    Edidin, A A; Villarraga, M L; Herr, M P; Muth, J; Yau, S S; Kurtz, S M

    2002-08-01

    In Part I of this series, we showed that aging at elevated oxygen pressure is more successful at increasing the depth to which degradation occurs although it, too, generally causes greater degradation at the surface than at the subsurface. Therefore we hypothesized that thermal degradation alone, in the absence of free radicals, could be sufficient to artificially age UHMWPE in a manner analogous to natural aging. In the present study, virgin and air-irradiated UHMWPE (extruded GUR 1050 and compression-molded 1900) were aged up to 4 weeks at elevated oxygen pressure, and the mechanical behavior at the surface and subsurface was examined. All the materials were substantially degraded following 4 weeks of aging, but the spatial variations in the nonirradiated materials more closely mimicked the previously observed subsurface peak of degradation seen in naturally aged UHMWPE following irradiation in air. This aged material could provide a more realistic model for subsurface mechanical degradation, making it suitable for further mechanical testing in venues such as wear simulation.

  18. Relative age effect in Japanese male athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2011-10-01

    The present study investigated the relative age effect, a biased distribution of elite athletes' birthdates, in Japanese male athletes. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. A total of 4,318 male athletes was evaluated from 12 sports: baseball, soccer, basketball, volleyball, handball, golf, horse racing, rugby, American football, sumo, Ekiden (track and field in long distance), and badminton. They played in the top level of Japanese leagues for each sport in 2010. The distribution of the birth dates was examined in each sport and showed significant relative age effect in baseball, soccer, volleyball, Ekiden, basketball, sumo, and horse racing, but not in all sports. The findings suggest that although the school year in Japan starts on April 1, significant relative age effects are observed in some sporting events. PMID:22185072

  19. Relative age effect in Japanese male athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2011-10-01

    The present study investigated the relative age effect, a biased distribution of elite athletes' birthdates, in Japanese male athletes. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. A total of 4,318 male athletes was evaluated from 12 sports: baseball, soccer, basketball, volleyball, handball, golf, horse racing, rugby, American football, sumo, Ekiden (track and field in long distance), and badminton. They played in the top level of Japanese leagues for each sport in 2010. The distribution of the birth dates was examined in each sport and showed significant relative age effect in baseball, soccer, volleyball, Ekiden, basketball, sumo, and horse racing, but not in all sports. The findings suggest that although the school year in Japan starts on April 1, significant relative age effects are observed in some sporting events.

  20. Age related changes in age of starting to smoke.

    PubMed

    Weinkam, J J; Sterling, T D

    1990-01-01

    The Average Age of Starting to Smoke (AASS) has been reported to decline for younger birth cohorts. That apparent decline has been used to support a conclusion of an increase in smoking among younger individuals. However, in some cases the apparent decline is an artifact of the method of computation which arises when the quantity being averaged is related to a quantity used to classify subjects for comparison. In one other case, a second type of error arises because the distribution of smoking initiation with age changed in such a way that the proportion of individuals taking up smoking at older ages declined more rapidly than the proportion starting at younger ages. In fact, comparison of the 1970 National Health Interview Survey (NHIS) to the 1979/80 NHIS shows a uniform decrease in starting to smoke among teens and preteens. Examples are discussed which show that estimates of possible disease related factors actually experienced by a cohort are possible only if other suitable data are available for comparable representative sections of the population at different time periods and for different ages.

  1. Age related changes in age of starting to smoke.

    PubMed

    Weinkam, J J; Sterling, T D

    1990-01-01

    The Average Age of Starting to Smoke (AASS) has been reported to decline for younger birth cohorts. That apparent decline has been used to support a conclusion of an increase in smoking among younger individuals. However, in some cases the apparent decline is an artifact of the method of computation which arises when the quantity being averaged is related to a quantity used to classify subjects for comparison. In one other case, a second type of error arises because the distribution of smoking initiation with age changed in such a way that the proportion of individuals taking up smoking at older ages declined more rapidly than the proportion starting at younger ages. In fact, comparison of the 1970 National Health Interview Survey (NHIS) to the 1979/80 NHIS shows a uniform decrease in starting to smoke among teens and preteens. Examples are discussed which show that estimates of possible disease related factors actually experienced by a cohort are possible only if other suitable data are available for comparable representative sections of the population at different time periods and for different ages. PMID:2303843

  2. Gender Relations and Applied Research on Aging

    ERIC Educational Resources Information Center

    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…

  3. Hydrogen degradation of steels and its related parameters, a review

    NASA Astrophysics Data System (ADS)

    Shirband, Zeynab; Shishesaz, Mohammad Reza; Ashrafi, Ali

    2011-11-01

    Many steel structures can absorb varying amounts of hydrogen during manufacturing, processing such as electroplating or acid pickling and during service life by corrosion reactions or cathodic protection. Hydrogen is known to have a devastating effect on strength and ductility of iron and steel components. Many studies have been done on the detrimental effects of hydrogen on iron and different steel structures but there is a need for comprehensive research to cover all related parameters which can control the extent of hydrogen interaction and degradation in steels. In this review, at first hydrogen uptake and different damages associated with absorbed hydrogen in steels are discussed. Then, the effective parameters in the extent of hydrogen interaction and degradation, especially hydrogen embrittlement which is more common in steel components are reviewed.

  4. Environmental aging degradation in continuous fiber ceramic composites

    SciTech Connect

    Plucknett, K.P.; Lin, H.T.; Braski, D.N.; Becher, P.F.

    1995-12-31

    The thermal stability of two-continuous fiber ceramic composites (CFCC`s) has been assessed. A Nicalon/CaO-Al{sub 2}O{sub 3}-SiO{sub 2} (CAS) glass-ceramic composite has been subjected to unstressed, oxidation heat treatments between 375 and 1200{degrees}C, after which the material was tested in flexure at room temperature. The static fatigue behavior of a chemical vapor infiltrated (CVI) Nicalon/SiC ceramic matrix composite has been assessed in air, between 425 and 1150{degrees}C, both with and without protective seal coating. Severe property degradation was observed due to oxidation of the graphite fiber/matrix interlayer in both CFCC`s.

  5. MicroRNAs in age-related diseases.

    PubMed

    Dimmeler, Stefanie; Nicotera, Pierluigi

    2013-02-01

    Aging is a complex process that is linked to an increased incidence of major diseases such as cardiovascular and neurodegenerative disease, but also cancer and immune disorders. MicroRNAs (miRNAs) are small non-coding RNAs, which post-transcriptionally control gene expression by inhibiting translation or inducing degradation of targeted mRNAs. MiRNAs target up to hundreds of mRNAs, thereby modulating gene expression patterns. Many miRNAs appear to be dysregulated during cellular senescence, aging and disease. However, only few miRNAs have been so far linked to age-related changes in cellular and organ functions. The present article will discuss these findings, specifically focusing on the cardiovascular and neurological systems.

  6. Audience Design and Social Relations in Aging.

    PubMed

    Keller-Cohen, Deborah

    2015-10-01

    This study asks two questions: (1) Do older adults modify their language based on age of the listener (audience design)? (2) Does social contact affect audience design in older adults? Older adults (n = 34; mean age = 82) engaged in an instructions task with two fictive listeners (a child and an adult) to test these questions. Results show that older adults used a greater total number of propositions and rapport-building devices and a lower type-token ratio when giving instructions to the child compared to the adult listener. Adults with more social interactions used more propositions when talking to a child. In addition, satisfaction with interactions was significantly positively related to task-tracking devices and negatively related to rapport-building devices by older adults. These results suggest that audience design and social relations are worth further study in language maintenance in older age. PMID:25651591

  7. Aging degradation of cast stainless steel: status and program

    SciTech Connect

    Chopra, O.K.; Ayrault, G.

    1983-10-01

    A program has been initiated to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. The existing data are reviewed to determine the critical parameters that control the aging behavior and to define the objectives and scope of the investigation. The test matrices for microstructural studies and mechanical property measurements are presented. The initial experimental effort is focussed on characterizing the microstructure of long-term, low-temperature aged material. Specimens from three heats of cast CF-8 and CF-8M stainless steel aged for up to 70,000 h at 300, 350, and 400/sup 0/C were obtained from George Fisher Ltd., of Switzerland. Initial analyses reveal the formation of three different types of precipitates which are not ..cap alpha..'. An FCC phase, similar to the M/sub 23/C/sub 6/ precipitates, was present in all the long-term aged material. 15 references, 10 figures, 2 tables.

  8. Age-related hair pigment loss.

    PubMed

    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. PMID:26370651

  9. Identification of CSSC Caused by Aging and Degradation

    SciTech Connect

    Florescu, Gheorghe; Cojan, Mihail

    2006-07-01

    PSA studies, that were developed for some NPPs, permit the using of the created models to perform many research tests, in order to optimize the structures, systems and components (SSCs) operation or to identify the NPP or systems weaknesses, due to specific or special factors. SSCs that influence decisively the NPP reliability are considered as critical. Also, for the accident conditions, the SSC, which have a major influence to the system availability or operability, are considered as critical. Many worldwide NPPs reached the life time or are very close to do that. Several SSCs have shorter life times than NPP's life time. Ageing is one of the factors that decrease the SSC life time. Due to ageing, if are not replaced, some SSCs, or groups of redundant SSCs, become critical looking to safety. Some questions for what to do in the situation when a SSC must be replaced and the SSC specific manufacturer does not exist, could also be put. The paper tried to solve the problem of SSC modeling by introducing of an ageing factor in SSC model. Fault tree (F/T) modeling approach is assumed. There are two possibilities for modeling: failure rates that are changed or specific MCS. (authors)

  10. Phylogeny of Aging and Related Phenoptotic Phenomena.

    PubMed

    Libertini, G

    2015-12-01

    The interpretation of aging as adaptive, i.e. as a phenomenon genetically determined and modulated, and with an evolutionary advantage, implies that aging, as any physiologic mechanism, must have phylogenetic connections with similar phenomena. This review tries to find the phylogenetic connections between vertebrate aging and some related phenomena in other species, especially within those phenomena defined as phenoptotic, i.e. involving the death of one or more individuals for the benefit of other individuals. In particular, the aim of the work is to highlight and analyze similarities and connections, in the mechanisms and in the evolutionary causes, between: (i) proapoptosis in prokaryotes and apoptosis in unicellular eukaryotes; (ii) apoptosis in unicellular and multicellular eukaryotes; (iii) aging in yeast and in vertebrates; and (iv) the critical importance of the DNA subtelomeric segment in unicellular and multicellular eukaryotes. In short, there is strong evidence that vertebrate aging has clear similarities and connections with phenomena present in organisms with simpler organization. These phylogenetic connections are a necessary element for the sustainability of the thesis of aging explained as an adaptive phenomenon, and, on the contrary, are incompatible with the opposite view of aging as being due to the accumulation of random damages of various kinds.

  11. Phylogeny of Aging and Related Phenoptotic Phenomena.

    PubMed

    Libertini, G

    2015-12-01

    The interpretation of aging as adaptive, i.e. as a phenomenon genetically determined and modulated, and with an evolutionary advantage, implies that aging, as any physiologic mechanism, must have phylogenetic connections with similar phenomena. This review tries to find the phylogenetic connections between vertebrate aging and some related phenomena in other species, especially within those phenomena defined as phenoptotic, i.e. involving the death of one or more individuals for the benefit of other individuals. In particular, the aim of the work is to highlight and analyze similarities and connections, in the mechanisms and in the evolutionary causes, between: (i) proapoptosis in prokaryotes and apoptosis in unicellular eukaryotes; (ii) apoptosis in unicellular and multicellular eukaryotes; (iii) aging in yeast and in vertebrates; and (iv) the critical importance of the DNA subtelomeric segment in unicellular and multicellular eukaryotes. In short, there is strong evidence that vertebrate aging has clear similarities and connections with phenomena present in organisms with simpler organization. These phylogenetic connections are a necessary element for the sustainability of the thesis of aging explained as an adaptive phenomenon, and, on the contrary, are incompatible with the opposite view of aging as being due to the accumulation of random damages of various kinds. PMID:26638678

  12. Work related injury among aging women.

    PubMed

    Harrison, Tracie; Legarde, Brittany; Kim, Sunhun; Walker, Janiece; Blozis, Shelley; Umberson, Debra

    2013-02-01

    This article reports the experiences of women aged 55 to 75 with mobility impairments who attributed aspects of their limitations to workplace injuries and provides insight into worker's compensation policies. The study sample includes Mexican American (MA) and non-Hispanic White (NHW) women aged 55 to 75 who participated in a 4-year ethnographic study of disablement. Ninety-two of the 122 participants in the study attributed aspects of their functional limitations to employment, and their experiences were analyzed using data from 354 meetings. Using Lipscomb and colleagues' conceptual model of work and health disparities, the women's experiences were grouped into three categories according to type of injury, assistance gained, and the consequences of a workplace injury; the results have broad implications for policies that influence aging outcomes. Workplace injuries causing permanent functional limitations compound the effects of age and gender on employment outcomes. Policies addressing health disparities should consider work related influences. PMID:23528432

  13. Work Related Injury among Aging Women

    PubMed Central

    LeGarde, Brittany; Kim, SungHun; Walker, Janiece; Blozis, Shelley; Umberson, Debra

    2013-01-01

    This article reports the experiences of women age 55 to 75 with mobility impairments who attributed aspects of their limitations to workplace injuries and provides insight into worker’s compensation policies. The study sample includes Mexican American and non-Hispanic White women ages 55–75 who participated in a 4-year ethnographic study of disablement. Ninety-two of the 122 participants in the study attributed aspects of their functional limitations to employment, and their experiences were analyzed using data from 354 meetings. Using Lipscomb and colleagues’ conceptual model of work and health disparities, the women’s experiences were grouped into three categories according to type of injury, assistance gained, and the consequences of a workplace injury; the results have broad implications for policies that influence aging outcomes. Workplace injuries causing permanent functional limitations compound the effects of age and gender on employment outcomes. Policies addressing health disparities should consider work related influences. PMID:23528432

  14. Driving and Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Owsley, Cynthia; McGwin, Gerald, Jr.

    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,…

  15. Structural degradation of acrylic bone cements due to in vivo and simulated aging.

    PubMed

    Hughes, Kerry F; Ries, Michael D; Pruitt, Lisa A

    2003-05-01

    Acrylic bone cement is the primary load-bearing material used for the attachment of orthopedic devices to adjoining bone. Degradation of acrylic-based cements in vivo results in a loss of structural integrity of the bone-cement-prosthesis interface and limits the longevity of cemented orthopedic implants. The purpose of this study is to investigate the effect of in vivo aging on the structure of the acrylic bone cement and to develop an in vitro artificial aging protocol that mimics the observed degradation. Three sets of retrievals are examined in this study: Palacos brand cement retrieved from hip replacements, and Simplex brand cement retrieved from both hip and knee replacement surgeries. In vitro aging is performed using oxidative and acidic environments on three acrylic-based cements: Palacos, Simplex, and CORE. Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) are used to examine the evolution of molecular weight and chemical species within the acrylic cements due to both in vivo and simulated aging. GPC analysis indicates that molecular weight is degraded in the hip retrievals but not in the knee retrievals. Artificial aging in an oxidative environment best reproduces this degradation mechanism. FTIR analysis indicates that there exists a chemical evolution within the cement due to in vivo and in vitro aging. These findings are consistent with scission-based degradation schemes in the cement. Based on the results of this study, a pathway for structural degradation of acrylic bone cement is proposed. The findings from this investigation have broad applicability to acrylic-based cements and may provide guidance for the development of new bone cements that resist degradation in the body.

  16. The age of astronomy-related organizations

    NASA Astrophysics Data System (ADS)

    Heck, A.

    1999-03-01

    The age of currently active astronomy-related organizations is investigated from comprehensive and up-to-date samples. Results for professional institutions, associations, planetariums, and public observatories are commented, as well as specific distributions for astronomy-related publishers and software producers. Some events had a clear impact on the rate of foundation of astronomy-related organizations, such as World War I and II, the beginning of space exploration and the landing of man on the Moon, but not all of them affected in the same way Western Europe and North America. It is still premature to assess the impact of the end of the Cold War. A category such as the software producers would of course not exist nor prosper without the advent of the computer age and the subsequent electronic networking of the planet. Other aspects are discussed in the paper.

  17. Neuropharmacology of depression in aging and age-related diseases.

    PubMed

    Gareri, Pietro; De Fazio, Pasquale; De Sarro, Giovambattista

    2002-02-01

    Depression in the elderly is nowadays a predominant health care problem, mainly due to the progressive aging of the population. It results from psychosocial stress, polypathology, as well as some biochemical changes which occur in the aged brain and can lead to cognitive impairments, increased symptoms from medical illness, higher utilization of health care services and increased rates of suicide and non-suicide mortality. Depression may be also caused by a various number of drugs currently administered; this is remarkable especially in elderly people, where polypathology is often associated with polypharmacotherapy. However, the pathogenesis of geriatric depression is not well understood; major depression may arise from dysfunction of the limbic-hypothalamic-pituitary-adrenal axis. Some clinical observations also suggest that striato-frontal dysfunction is associated with late life depression. A number of hypotheses have been made, focusing that mood disturbances are probably linked to a disturbed central metabolism of monoamines 5-hydroxytryptamine, noradrenaline and dopamine; however most of this knowledge is derived from animal models. Parkinson's and Alzheimer's diseases are age-related diseases associated to decreased activity or brain lesions in the orbital frontal cortex and basal ganglia. These observations lead to the hypothesis that the dysfunction of one or more of the cortical basal ganglia-thalamic neuronal loops are involved in the pathophysiology of primary and secondary depression. This dysfunction may be mediated by decreased serotonin release and probably, also by reduction in serotonin receptors. Development of novel approaches such as dynamic brain imaging methods, together with indirect knowledge coming from the effects of new antidepressants, will increase the understanding of neurochemistry of depression in old age. PMID:12039452

  18. [Treatment options for age-related infertility].

    PubMed

    Belaisch-Allart, Joëlle

    2010-06-20

    There has been a consistent trend towards delayed childbearing in most Western countries. Treatment options for age-related infertility includes controlled ovarian hyperstimulation with intrauterine insemination and in vitro fertilization (IVF). A sharp decline in pregnancy rate with advancing female age is noted with assisted reproductive technologies (ART) including IVF. Evaluation and treatment of infertility should not be delayed in women 35 years and older. No treatment other than oocyte donation has been shown to be effective for women over 40 and for those with compromised ovarian reserve, but its pratice is not easy in France hence the procreative tourism. As an increasing number of couples choose to postpone childbearing, they should be informed that maternal age is an important risk factor for failure to conceive. PMID:20623902

  19. [Aged woman's vulnerability related to AIDS].

    PubMed

    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.

  20. Immunolocalization of Tom1 in relation to protein degradation systems in Alzheimer's disease.

    PubMed

    Makioka, Kouki; Yamazaki, Tsuneo; Takatama, Masamitsu; Ikeda, Masaki; Murayama, Shigeo; Okamoto, Koichi; Ikeda, Yoshio

    2016-06-15

    Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Its pathological hallmarks are senile plaques (SPs), which contain extracellular deposits of amyloid β (Aβ) protein fibrils and dystrophic neurites (DNs), and neurofibrillary tangles (NFTs) containing hyperphosphorylated tau. Impairment of protein-degradation systems, including the ubiquitin-proteasome and the autophagy-lysosome systems, has been proposed as one of the causes of the accumulation of these aberrant proteins in AD brains. Tom1 (target of Myb1) was originally identified by the induction of its expression by the v-Myb oncogene and is a part of two major protein-degradation systems. The present study was conducted by immunohistochemical and immunofluorescent stainings to show that Tom1 was localized in DNs, perisomatic granules (PSGs), and NFTs in AD brains. Moreover, in DNs, Tom1 colocalized with ubiquitin, lysosomal proteins, and Tom1-related proteins (Tollip and myosin VI), which act in both protein-degradation systems via Tom1. These results indicate that Tom1 plays important roles in protein-degradation systems in AD pathogenesis.

  1. Immunolocalization of Tom1 in relation to protein degradation systems in Alzheimer's disease.

    PubMed

    Makioka, Kouki; Yamazaki, Tsuneo; Takatama, Masamitsu; Ikeda, Masaki; Murayama, Shigeo; Okamoto, Koichi; Ikeda, Yoshio

    2016-06-15

    Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Its pathological hallmarks are senile plaques (SPs), which contain extracellular deposits of amyloid β (Aβ) protein fibrils and dystrophic neurites (DNs), and neurofibrillary tangles (NFTs) containing hyperphosphorylated tau. Impairment of protein-degradation systems, including the ubiquitin-proteasome and the autophagy-lysosome systems, has been proposed as one of the causes of the accumulation of these aberrant proteins in AD brains. Tom1 (target of Myb1) was originally identified by the induction of its expression by the v-Myb oncogene and is a part of two major protein-degradation systems. The present study was conducted by immunohistochemical and immunofluorescent stainings to show that Tom1 was localized in DNs, perisomatic granules (PSGs), and NFTs in AD brains. Moreover, in DNs, Tom1 colocalized with ubiquitin, lysosomal proteins, and Tom1-related proteins (Tollip and myosin VI), which act in both protein-degradation systems via Tom1. These results indicate that Tom1 plays important roles in protein-degradation systems in AD pathogenesis. PMID:27206884

  2. [Epidemiology of age related macular degeneration].

    PubMed

    Leveziel, N; Delcourt, C; Zerbib, J; Dollfus, H; Kaplan, J; Benlian, P; Coscas, G; Souied, E H; Soubrane, G

    2009-06-01

    Age-related macular degeneration (ARMD) is a multifactorial and polygenic disease and is the main cause of vision loss in developed countries. The environmental factors of ARMD can modify prevalence and incidence of this disease. This article is a review of the main environmental factors currently recognized as at risk or protective factor for ARMD. Modification of these factors is of crucial importance because it could delay the onset of exudative or atrophic forms of the disease. PMID:19515460

  3. Oxidative modification of proteins: age-related changes.

    PubMed

    Chakravarti, Bulbul; Chakravarti, Deb N

    2007-01-01

    Aging is a complex biological phenomenon which involves progressive loss of different physiological functions of various tissues of living organisms. It is the inevitable fate of life and is a major risk factor for death and different pathological disorders. Based on a wide variety of studies performed in humans as well as in various animal models and microbial systems, reactive oxygen species (ROS) are believed to play a key role in the aging process. The production of ROS is influenced by cellular metabolic activities as well as environmental factors. ROS can react with all major biological macromolecules such as carbohydrates, nucleic acids, lipids, and proteins. Since, in general, proteins are the key molecules that play the ultimate role in various structural and functional aspects of living organisms, this review will focus on the age-related oxidative modifications of proteins as well as on mechanism for removal or repair of the oxidized proteins. The topics covered include protein oxidation as a marker of oxidative stress, experimental evidence indicating the role of ROS in protein oxidation, protein carbonyl content, enzymatic degradation of oxidized proteins, and effects of caloric restriction on protein oxidation in the context of aging. Finally, we will discuss different strategies which have been or can be undertaken to slow down the oxidative damage of proteins and the aging process.

  4. GENETICS OF HUMAN AGE RELATED DISORDERS.

    PubMed

    Srivastava, I; Thukral, N; Hasija, Y

    2015-01-01

    Aging is an inevitable biological phenomenon. The incidence of age related disorders (ARDs) such as cardiovascular diseases, cancer, arthritis, dementia, osteoporosis, diabetes, neurodegenerative diseases increase rapidly with aging. ARDs are becoming a key social and economic trouble for the world's elderly population (above 60 years), which is expected to reach 2 billion by 2050. Advancement in understanding of genetic associations, particularly through genome wide association studies (GWAS), has revealed a substantial contribution of genes to human aging and ARDs. In this review, we have focused on the recent understanding of the extent to which genetic predisposition may influence the aging process. Further analysis of the genetic association studies through pathway analysis several genes associated with multiple ARDs have been highlighted such as apolipoprotein E (APOE), brain-derived neurotrophic factor (BDNF), cadherin 13 (CDH13), CDK5 regulatory subunit associated protein 1 (CDKAL-1), methylenetetrahydrofolate reductase (MTHFR), disrupted in schizophrenia 1 (DISC1), nitric oxide synthase 3 (NOS3), paraoxonase 1 (PON1), indicating that these genes could play a pivotal role in ARD causation. These genes were found to be significantly enriched in Jak-STAT signalling pathway, asthma and allograft rejection. Further, interleukin-6 (IL-6), insulin (INS), vascular endothelial growth factor A (VEGFA), estrogen receptor1 (ESR1), transforming growth factor, beta 1(TGFB1) and calmodulin 1 (CALM1) were found to be highly interconnected in network analysis. We believe that extensive research on the presence of common genetic variants among various ARDs may facilitate scientists to understand the biology behind ARDs causation. PMID:26856084

  5. Degradation of mechanical behavior in UHMWPE after natural and accelerated aging.

    PubMed

    Edidin, A A; Jewett, C W; Kalinowski, A; Kwarteng, K; Kurtz, S M

    2000-07-01

    Ultra-high molecular weight polyethylene (UHMWPE) is known to degrade during natural (shelf) aging following gamma irradiation in air, but the mechanical signature of degradation remains poorly understood. Accelerated aging methods have been developed to reproduce the natural aging process as well as to precondition total joint replacement components prior to joint simulator wear testing. In this study, we compared the mechanical behavior of naturally (shelf) aged and accelerated aged tibial inserts using a previously validated miniature specimen testing technique known as the small punch test. Tibial inserts made-of GUR 1120 and sterilized with 25 to 40 kGy of gamma radiation (in air) in 1988, 1993, and 1997 were obtained; a subset of the 1997 implants were subjected to 4 weeks of accelerated aging in air at 80 degrees C. To determine the spatial variation of mechanical properties within each insert, miniature disk shaped specimens were machined from the surface and subsurface regions of the inserts. Analysis of variance of the test data showed that aging significantly affected the small punch test measures of elastic modulus, initial load, ultimate load, ultimate displacement, and work to failure. The accelerated aging protocol was unable to reproduce the spatial mechanical profile seen in shelf aged components, but it did mechanically degrade the surface of GUR 1120 tibial components to an extent comparable to that seen after 10 years of natural aging. Test specimens showed a fracture morphology consistent with the decreased ductility and toughness which was corroborated by the small punch test metrics of this study. Our data support the hypothesis that UHMWPE undergoes a spatially nonuniform change towards a less ductile (more brittle) mechanical behavior after gamma irradiation in air and shelf aging.

  6. The Neural Consequences of Age-Related Hearing Loss.

    PubMed

    Peelle, Jonathan E; Wingfield, Arthur

    2016-07-01

    During hearing, acoustic signals travel up the ascending auditory pathway from the cochlea to auditory cortex; efferent connections provide descending feedback. In human listeners, although auditory and cognitive processing have sometimes been viewed as separate domains, a growing body of work suggests they are intimately coupled. Here, we review the effects of hearing loss on neural systems supporting spoken language comprehension, beginning with age-related physiological decline. We suggest that listeners recruit domain general executive systems to maintain successful communication when the auditory signal is degraded, but that this compensatory processing has behavioral consequences: even relatively mild levels of hearing loss can lead to cascading cognitive effects that impact perception, comprehension, and memory, leading to increased listening effort during speech comprehension. PMID:27262177

  7. The Neural Consequences of Age-Related Hearing Loss.

    PubMed

    Peelle, Jonathan E; Wingfield, Arthur

    2016-07-01

    During hearing, acoustic signals travel up the ascending auditory pathway from the cochlea to auditory cortex; efferent connections provide descending feedback. In human listeners, although auditory and cognitive processing have sometimes been viewed as separate domains, a growing body of work suggests they are intimately coupled. Here, we review the effects of hearing loss on neural systems supporting spoken language comprehension, beginning with age-related physiological decline. We suggest that listeners recruit domain general executive systems to maintain successful communication when the auditory signal is degraded, but that this compensatory processing has behavioral consequences: even relatively mild levels of hearing loss can lead to cascading cognitive effects that impact perception, comprehension, and memory, leading to increased listening effort during speech comprehension.

  8. Age-Related Tissue Stiffening: Cause and Effect

    PubMed Central

    Sherratt, Michael J.

    2013-01-01

    Significance Tissue elasticity is severely compromised in aging skin, lungs, and blood vessels. In the vascular and pulmonary systems, respectively, loss of mechanical function is linked to hypertension, which in turn is a risk factor for heart and renal failure, stroke, and aortic aneurysms, and to an increased risk of mortality as a result of acute lung infections. Recent Advances Although cellular mechanisms were thought to play an important role in mediating tissue aging, the reason for the apparent sensitivity of elastic fibers to age-related degradation remained unclear. We have recently demonstrated that compared with type I collagen, a key component of the elastic fiber system, the cysteine-rich fibrillin microfibril is highly susceptible to direct UV exposure in a cell-free environment. We hypothesized therefore that, as a consequence of both their remarkable longevity and cysteine-rich composition, many elastic fiber-associated components will be susceptible to the accumulation of damage by both direct UV radiation and reactive oxygen species-mediated oxidation. Critical Issues Although elastic fiber remodeling is a common feature of aging dynamic tissues, the inaccessibility of most human tissues has hampered attempts to define the molecular causes. Clinical Care Relevance Although, currently, the localized repair of damaged elastic fibers may be effected by the topical application of retinoids and some cosmetic products, future studies may extend the application of systemic transforming growth factor β antagonists, which can prevent cardiovascular remodeling in murine Marfan syndrome, to aging humans. Acellular mechanisms may be key mediators of elastic fiber remodeling and hence age-related tissue stiffening. PMID:24527318

  9. Perception of Acoustically Degraded Sentences in Bilingual Listeners Who Differ in Age of English Acquisition

    ERIC Educational Resources Information Center

    Shi, Lu-Feng

    2010-01-01

    Purpose: The effects of acoustic degradation and context use on sentence perception were evaluated in listeners differing in age of English acquisition. Method: Five groups of 8 listeners, native monolingual (NM), native bilingual (NB), and early, late, and very late non-native bilingual (NN-E, NN-L, and NN-VL, respectively), identified target…

  10. Neural Alterations in Acquired Age-Related Hearing Loss

    PubMed Central

    Mudar, Raksha A.; Husain, Fatima T.

    2016-01-01

    Hearing loss is one of the most prevalent chronic health conditions in older adults. Growing evidence suggests that hearing loss is associated with reduced cognitive functioning and incident dementia. In this mini-review, we briefly examine literature on anatomical and functional alterations in the brains of adults with acquired age-associated hearing loss, which may underlie the cognitive consequences observed in this population, focusing on studies that have used structural and functional magnetic resonance imaging, diffusion tensor imaging, and event-related electroencephalography. We discuss structural and functional alterations observed in the temporal and frontal cortices and the limbic system. These neural alterations are discussed in the context of common cause, information-degradation, and sensory-deprivation hypotheses, and we suggest possible rehabilitation strategies. Although, we are beginning to learn more about changes in neural architecture and functionality related to age-associated hearing loss, much work remains to be done. Understanding the neural alterations will provide objective markers for early identification of neural consequences of age-associated hearing loss and for evaluating benefits of intervention approaches. PMID:27313556

  11. Relative age effect: implications for effective practice.

    PubMed

    Andronikos, Georgios; Elumaro, Adeboye Israel; Westbury, Tony; Martindale, Russell J J

    2016-01-01

    Physical and psychological differences related to birthdate amongst athletes of the same selection year have been characterised as the "relative age effects" (RAEs). RAEs have been identified in a variety of sports, both at youth and adult level, and are linked with dropout of athletes and a reduction of the talent pool. This study examined the existence, mechanisms and possible solutions to RAEs using qualitative methodology. Seven experts in the field of talent identification and development were interviewed. Inductive analysis of the data showed that, while there was mixed evidence for the existence of RAEs across sports, the eradication of RAEs was attributed to controllable features of the development environment. The factors reported included the structure of "categories" used to group athletes within the sport (e.g. age, weight, size, skills), recognition and prioritisation of long-term development over "short term win focus." Education of relevant parties (e.g. coaches, scouts, clubs) about RAEs and the nature of "talent" within a long-term context was suggested, along with careful consideration of the structure of the development environment (e.g. delayed selection, provision for late developers, focus on skills not results, use of challenge). Implications for research and practice are discussed.

  12. Degradation of explosives-related compounds using nickel catalysts.

    PubMed

    Fuller, Mark E; Schaefer, Charles E; Lowey, Jean M

    2007-03-01

    We report the ability of nickel-based catalysts to degrade explosives compounds in aqueous solution. Several nickel catalysts completely degraded the explosives, although rates varied. Nearly all of the organic explosive compounds tested, including 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), were rapidly degraded to below detection limits by a powdered nickel on an alumina-silicate support (Aldrich nickel catalyst). Perchlorate degradation was minimal (<25%). Degradation of TNT by Aldrich nickel catalyst resulted in apparent first-order kinetics. Significant gaseous 14C was released and collected in an alkaline solution (most likely carbon dioxide) from [14C]RDX and [14C]HMX, indicating heterocyclic ring cleavage. Significant gaseous 14C was not produced from [14C]TNT, but spectrophotometric evidence indicated loss of aromaticity. Degradation occurred in low ionic strength solutions, groundwater, and from pH 3 to pH 9. Degradation of TNT, RDX, and HMX was maintained in flow-through columns of Aldrich nickel catalyst mixed with sand down to a hydraulic retention time of 4h. These data indicate that nickel-based catalysts may be an effective means for remediation of energetics-contaminated groundwater.

  13. The endoplasmic reticulum stress response in aging and age-related diseases

    PubMed Central

    Brown, Marishka K.; Naidoo, Nirinjini

    2012-01-01

    The endoplasmic reticulum(ER) is a multifunctional organelle within which protein folding, lipid biosynthesis, and calcium storage occurs. Perturbations such as energy or nutrient depletion, disturbances in calcium or redox status that disrupt ER homeostasis lead to the misfolding of proteins, ER stress and up-regulation of several signaling pathways coordinately called the unfolded protein response (UPR). The UPR is characterized by the induction of chaperones, degradation of misfolded proteins and attenuation of protein translation. The UPR plays a fundamental role in the maintenance of cellular homeostasis and thus is central to normal physiology. However, sustained unresolved ER stress leads to apoptosis. Aging linked declines in expression and activity of key ER molecular chaperones and folding enzymes compromise proper protein folding and the adaptive response of the UPR. One mechanism to explain age associated declines in cellular functions and age-related diseases is a progressive failure of chaperoning systems. In many of these diseases, proteins or fragments of proteins convert from their normally soluble forms to insoluble fibrils or plaques that accumulate in a variety of organs including the liver, brain or spleen. This group of diseases, which typically occur late in life includes Alzheimer's, Parkinson's, type II diabetes and a host of less well known but often equally serious conditions such as fatal familial insomnia. The UPR is implicated in many of these neurodegenerative and familial protein folding diseases as well as several cancers and a host of inflammatory diseases including diabetes, atherosclerosis, inflammatory bowel disease and arthritis. This review will discuss age-related changes in the ER stress response and the role of the UPR in age-related diseases. PMID:22934019

  14. Animal models of age related macular degeneration

    PubMed Central

    Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444

  15. [Epidemiology of age-related macular degeneration].

    PubMed

    Brandl, C; Stark, K J; Wintergerst, M; Heinemann, M; Heid, I M; Finger, R P

    2016-09-01

    Age-related macular degeneration (AMD) is the main cause of blindness in industrialized societies. Population-based epidemiological investigations generate important data on prevalence, incidence, risk factors, and future trends. This review summarizes the most important epidemiological studies on AMD with a focus on their transferability to Germany including existing evidence for the main risk factors for AMD development and progression. Future tasks, such as the standardization of grading systems and the use of recent retinal imaging technology in epidemiological studies are discussed. In Germany, epidemiological data on AMD are scarce. However, the need for epidemiological research in ophthalmology is currently being addressed by several recently started population-based studies. PMID:27541733

  16. Inflammation in age-related macular degeneration.

    PubMed

    Ozaki, Ema; Campbell, Matthew; Kiang, Anna-Sophia; Humphries, Marian; Doyle, Sarah L; Humphries, Peter

    2014-01-01

    Age-related macular degeneration (AMD) is the leading cause of legal blindness in elderly individuals in the developed world, affecting 30-50 million people worldwide. AMD primarily affects the macular region of the retina that is responsible for the majority of central, color and daytime vision. The presence of drusen, extracellular protein aggregates that accumulate under the retinal pigment epithelium (RPE), is a major pathological hallmark in the early stages of the disease. The end stage 'dry' and 'wet' forms of the disease culminate in vision loss and are characterized by focal degeneration of the RPE and cone photoreceptors, and choroidal neovascularization (CNV), respectively. Being a multifactorial and genetically heterogeneous disease, the pathophysiology of AMD remains unclear, yet, there is ample evidence supporting immunological and inflammatory processes. Here, we review the recent literature implicating some of these immune processes in human AMD and in animal models. PMID:24664703

  17. Age-related macular degeneration: current treatments

    PubMed Central

    Hubschman, Jean Pierre; Reddy, Shantan; Schwartz, Steven D

    2009-01-01

    Purpose: Although important progress has been made in understanding age-related macular degeneration (AMD), management of the disease continues to be a challenge. AMD research has led to a widening of available treatment options and improved prognostic perspectives. This essay reviews these treatment options. Design: Interpretative essay. Methods: Literature review and interpretation. Results: Current treatments to preserve vision in patients with non-exudative AMD include antioxidant vitamins and mineral supplementations. Exudative AMD is currently most often treated monthly with anti-VEGF intravitreal injections. However, investigators are beginning to experiment with combination therapy and surgical approaches in an attempt to limit the number of treatment and reduce the financial burden on the health care system. Conclusion: By better understanding the basis and pathogenesis of AMD, newer therapies will continue to be developed that target specific pathways in patients with AMD, with the hoped for outcome of better management of the disease and improved visual acuity. PMID:19668560

  18. On the definition of age-related norms for visual function testing.

    PubMed

    Johnson, M A; Choy, D

    1987-04-15

    Cross-sectional psychophysical and electrophysiologic studies of aging indicate that visual function declines only slightly or not at all until age 50-60, at which time the decline in visual function rapidly accelerates. This accelerated loss of function may reflect an increased rate of natural cellular degradation, or it may reflect an increased proportion of subclinical pathology in the presumed normal older population. This paper provides a critical review of the changes in visual function that occur with age. The results of this review have implications for both the definition of age-matched control groups and for early detection of age-related pathology.

  19. Assessment of in-depth degradation of artificially aged triterpenoid paint varnishes using nonlinear microscopy techniques.

    PubMed

    Filippidis, George; Mari, Meropi; Kelegkouri, Lambrini; Philippidis, Aggelos; Selimis, Aleksandros; Melessanaki, Kristallia; Sygletou, Maria; Fotakis, Costas

    2015-04-01

    The present work investigates the applicability of nonlinear imaging microscopy for the precise assessment of degradation of the outer protective layers of painted artworks as a function of depth due to aging. Two fresh and artificially aged triterpenoid varnishes, dammar and mastic, were tested. Nonlinear imaging techniques have been employed as a new diagnostic tool for determination of the exact thickness of the affected region due to artificial aging of the natural varnishes. The measured thicknesses differ from the calculated mean penetration depths of the samples. These nondestructive, high resolution modalities are valuable analytical tools for aging studies and they have the potential to provide unique in-depth information. Single photon laser induced fluorescence measurements and Raman spectroscopy were used for the integrated investigation and analysis of aging effects in varnishes.

  20. Age-related consequences of childhood obesity.

    PubMed

    Kelsey, Megan M; Zaepfel, Alysia; Bjornstad, Petter; Nadeau, Kristen J

    2014-01-01

    The severity and frequency of childhood obesity has increased significantly over the past three to four decades. The health effects of increased body mass index as a child may significantly impact obese youth as they age. However, many of the long-term outcomes of childhood obesity have yet to be studied. This article examines the currently available longitudinal data evaluating the effects of childhood obesity on adult outcomes. Consequences of obesity include an increased risk of developing the metabolic syndrome, cardiovascular disease, type 2 diabetes and its associated retinal and renal complications, nonalcoholic fatty liver disease, obstructive sleep apnea, polycystic ovarian syndrome, infertility, asthma, orthopedic complications, psychiatric disease, and increased rates of cancer, among others. These disorders can start as early as childhood, and such early onset increases the likelihood of early morbidity and mortality. Being obese as a child also increases the likelihood of being obese as an adult, and obesity in adulthood also leads to obesity-related complications. This review outlines the evidence for childhood obesity as a predictor of adult obesity and obesity-related disorders, thereby emphasizing the importance of early intervention to prevent the onset of obesity in childhood. PMID:24434909

  1. Age-related consequences of childhood obesity.

    PubMed

    Kelsey, Megan M; Zaepfel, Alysia; Bjornstad, Petter; Nadeau, Kristen J

    2014-01-01

    The severity and frequency of childhood obesity has increased significantly over the past three to four decades. The health effects of increased body mass index as a child may significantly impact obese youth as they age. However, many of the long-term outcomes of childhood obesity have yet to be studied. This article examines the currently available longitudinal data evaluating the effects of childhood obesity on adult outcomes. Consequences of obesity include an increased risk of developing the metabolic syndrome, cardiovascular disease, type 2 diabetes and its associated retinal and renal complications, nonalcoholic fatty liver disease, obstructive sleep apnea, polycystic ovarian syndrome, infertility, asthma, orthopedic complications, psychiatric disease, and increased rates of cancer, among others. These disorders can start as early as childhood, and such early onset increases the likelihood of early morbidity and mortality. Being obese as a child also increases the likelihood of being obese as an adult, and obesity in adulthood also leads to obesity-related complications. This review outlines the evidence for childhood obesity as a predictor of adult obesity and obesity-related disorders, thereby emphasizing the importance of early intervention to prevent the onset of obesity in childhood.

  2. Technical note: nitrogen fertilization effects on the degradation of aged diesel oil in composted drilling wastes.

    PubMed

    Choi, Woo-Jung; Chang, Scott X

    2009-07-01

    Hydrocarbon-contaminated wastes generated from oil and gas drilling activities may be used as a soil amendment once composted and further decomposition of residual hydrocarbons can be accomplished after the composts are applied to soils. To test if N fertilization may enhance hydrocarbon decomposition, we investigated the effects of N application on hydrocarbon degradation in different-aged composts (1-, 2-, 3-, and 4-year-old composts, coded as 1Y, 2Y, 3Y, and 4Y composts, respectively) through a pot experiment planted with white spruce (Picea glauca [Moench] Voss) seedlings. The percentage degradation of total petroleum hydrocarbon (TPH, C11 to C40) in the composts without N fertilization was correlated to initial NH4+ concentrations (R = 0.99, P < 0.001). The percentage degradation of TPH was highest in the 3Y compost (41.1%) that had an initial level of 325.3 mg NH4+ -N kg(-1) and the lowest in the IY compost (9.3%) that had an initial level of 8.3 mg NH4+ -N kg(-1). The degradation of TPH was enhanced by Nfertilization in the 1Y (from 9.3 to 15.3%) and 4Y composts (from 14.3 to 22.6%) that had low initial NH4+ concentrations. Our results show that application of NH4+ -based fertilizers may enhance the degradation of TPH when initial NH4+ concentrations in the compost are low. PMID:19810347

  3. Nut consumption and age-related disease.

    PubMed

    Grosso, G; Estruch, R

    2016-02-01

    Current knowledge on the effects of nut consumption on human health has rapidly increased in recent years and it now appears that nuts may play a role in the prevention of chronic age-related diseases. Frequent nut consumption has been associated with better metabolic status, decreased body weight as well as lower body weight gain over time and thus reduce the risk of obesity. The effect of nuts on glucose metabolism, blood lipids, and blood pressure is still controversial. However, significant decreased cardiovascular risk has been reported in a number of observational and clinical intervention studies. Thus, findings from cohort studies show that increased nut consumption is associated with a reduced risk of cardiovascular disease and mortality (especially that due to cardiovascular-related causes). Similarly, nut consumption has been also associated with reduced risk of certain cancers, such as colorectal, endometrial, and pancreatic neoplasms. Evidence regarding nut consumption and neurological or psychiatric disorders is scarce, but a number of studies suggest significant protective effects against depression, mild cognitive disorders and Alzheimer's disease. The underlying mechanisms appear to include antioxidant and anti-inflammatory actions, particularly related to their mono- and polyunsaturated fatty acids (MUFA and PUFA, as well as vitamin and polyphenol content). MUFA have been demonstrated to improve pancreatic beta-cell function and regulation of postprandial glycemia and insulin sensitivity. PUFA may act on the central nervous system protecting neuronal and cell-signaling function and maintenance. The fiber and mineral content of nuts may also confer health benefits. Nuts therefore show promise as useful adjuvants to prevent, delay or ameliorate a number of chronic conditions in older people. Their association with decreased mortality suggests a potential in reducing disease burden, including cardiovascular disease, cancer, and cognitive impairments

  4. Nut consumption and age-related disease.

    PubMed

    Grosso, G; Estruch, R

    2016-02-01

    Current knowledge on the effects of nut consumption on human health has rapidly increased in recent years and it now appears that nuts may play a role in the prevention of chronic age-related diseases. Frequent nut consumption has been associated with better metabolic status, decreased body weight as well as lower body weight gain over time and thus reduce the risk of obesity. The effect of nuts on glucose metabolism, blood lipids, and blood pressure is still controversial. However, significant decreased cardiovascular risk has been reported in a number of observational and clinical intervention studies. Thus, findings from cohort studies show that increased nut consumption is associated with a reduced risk of cardiovascular disease and mortality (especially that due to cardiovascular-related causes). Similarly, nut consumption has been also associated with reduced risk of certain cancers, such as colorectal, endometrial, and pancreatic neoplasms. Evidence regarding nut consumption and neurological or psychiatric disorders is scarce, but a number of studies suggest significant protective effects against depression, mild cognitive disorders and Alzheimer's disease. The underlying mechanisms appear to include antioxidant and anti-inflammatory actions, particularly related to their mono- and polyunsaturated fatty acids (MUFA and PUFA, as well as vitamin and polyphenol content). MUFA have been demonstrated to improve pancreatic beta-cell function and regulation of postprandial glycemia and insulin sensitivity. PUFA may act on the central nervous system protecting neuronal and cell-signaling function and maintenance. The fiber and mineral content of nuts may also confer health benefits. Nuts therefore show promise as useful adjuvants to prevent, delay or ameliorate a number of chronic conditions in older people. Their association with decreased mortality suggests a potential in reducing disease burden, including cardiovascular disease, cancer, and cognitive impairments.

  5. Relative humidity and temperature dependence of mechanical degradation of natural fiber composites

    NASA Astrophysics Data System (ADS)

    Pan, YiHui; Zhong, Zheng

    2016-06-01

    In this paper, the mechanical degradation of natural fiber composites is studied with the consideration of the relative humidity and the temperature. A nonlinear constitutive model is established, which employs an internal variable to describe the mechanical degradation related to the energy dissipation during moisture absorption. The existing experimental researches demonstrated that the mechanical degradation is an irreversible thermodynamic process induced by the degradation of fibers and the damages of interfaces between fiber and matrix, both of which depend on the variation of the relative humidity or the temperature. The evolution of the mechanical degradation is obtained through the determination of dissipation rates as a function of the relative humidity and the temperature. The theoretically predicted mechanical degradations are compared with experimental results of sisal fiber reinforced composites subject to different relative humidity and temperatures, and a good agreement is found.

  6. Aging modulates calcium-dependent phosphatidylinositol degradation by cerebral cortex synaptic plasma membrane phospholipases.

    PubMed

    Strosznajder, J; Samochocki, M; Wikieł, H; Małecki, A

    1994-01-01

    The synaptic plasma membrane (SPM) and cytosol fractions from cerebral cortex of adult (4-mo-old) and aged (27-mo-old) rats were used as a source of phospholipase A2 (PLA2) and phospholipase C (PLC). The activity of PLC acting on [3H-inositol]phosphatidylinositol ([3H]PtdIns) was investigated in the presence of endogenous and 2 mM Ca2+. Arachidonic acid (AA) release was studied in the same conditions, using 1-stearoyl-[2-14C]arachidonyl-sn-glycerophosphoinositol ([14C]PtdIns) as a substrate. In the presence of endogenous Ca2+ (i.e., no added Ca2+) SPM-bound PLC and PLA2 or diacylglycerol (DAG) lipase of aged brain exert significantly higher activity in degradation of PtdIns as compared to their activities in adult brain. Moreover, these enzymes of aged brain are less or not further activated by 2 mM Ca2+, contrary to the enzymes isolated from adult brain. The activity of cytosolic enzymes involved in degradation [3H]PtdIns and [14C]PtdIns and their regulation by Ca2+ ions are not significantly changed in senescent cerebral cortex as compared to the adult. The intracellular calcium concentration ([Ca2+]i), measured with fura-2, is lower in aged brain compared to adult brain, which may suggest the modification in Ca2+ ion redistribution in aged brain and probably its higher concentration in membranes. These results indicate that aging modifies significantly the activity of membrane-bound, Ca(2+)-dependent phospholipase(s) degrading PtdIns, which may be connected with alteration of Ca2+ ion redistribution and may influence the formation and accumulation of very potent lipid messengers as diacylglycerol, lysophospholipid, and arachidonic acid, known to be involved in neurotransmission processes. PMID:8179775

  7. Mechanisms of age-related macular degeneration

    PubMed Central

    Ambati, Jayakrishna; Fowler, Benjamin J.

    2012-01-01

    Age-related macular degeneration (AMD), a progressive condition that is untreatable in up to 90% of patients, is a leading cause of blindness in the elderly worldwide. The two forms of AMD, wet and dry, are classified based on the presence or absence of blood vessels that have disruptively invaded the retina, respectively. A detailed understanding of the molecular mechanisms underlying wet AMD has led to several robust FDA-approved therapies. In contrast, there are not any approved treatments for dry AMD. In this review, we provide insight into the critical effector pathways that mediate each form of disease. The interplay of immune and vascular systems for wet AMD, and the proliferating interest in hunting for gene variants to explain AMD pathogenesis, are placed in the context of the latest clinical and experimental data. Emerging models of dry AMD pathogenesis are presented, with a focus on DICER1 deficit and the toxic accumulation of retinal debris. A recurring theme that spans most aspects of AMD pathogenesis is defective immune modulation in the classically immune-privileged ocular haven. Interestingly, the latest advances in AMD research highlight common molecular disease pathways with other common neurodegenerations. Finally, the therapeutic potential of intervening at known mechanisms of AMD pathogenesis is discussed. PMID:22794258

  8. Association of Age Related Macular Degeneration and Age Related Hearing Impairment

    PubMed Central

    Ghasemi, Hassan; Pourakbari, Malihe Shahidi; Entezari, Morteza; Yarmohammadi, Mohammad Ebrahim

    2016-01-01

    Purpose: To evaluate the association between age-related macular degeneration (ARMD) and sensory neural hearing impairment (SHI). Methods: In this case-control study, hearing status of 46 consecutive patients with ARMD were compared with 46 age-matched cases without clinical ARMD as a control group. In all patients, retinal involvements were confirmed by clinical examination, fluorescein angiography (FA) and optical coherence tomography (OCT). All participants were examined with an otoscope and underwent audiological tests including pure tone audiometry (PTA), speech reception threshold (SRT), speech discrimination score (SDS), tympanometry, reflex tests and auditory brainstem response (ABR). Results: A significant (P = 0.009) association was present between ARMD, especially with exudative and choroidal neovascularization (CNV) components, and age-related hearing impairment primarily involving high frequencies. Patients had higher SRT and lower SDS against anticipated presbycusis than control subjects. Similar results were detected in exudative, CNV and scar patterns supporting an association between late ARMD with SRT and SDS abnormalities. ABR showed significantly prolonged wave I and IV latency times in ARMD (P = 0.034 and 0.022, respectively). Average latency periods for wave I in geographic atrophy (GA) and CNV, and that for wave IV in drusen patterns of ARMD were significantly higher than controls (P = 0.030, 0.007 and 0.050, respectively). Conclusion: The association between ARMD and age-related SHI may be attributed to common anatomical components such as melanin in these two sensory organs. PMID:27195086

  9. Age-Related Changes in the Misinformation Effect.

    ERIC Educational Resources Information Center

    Sutherland, Rachel; Hayne, Harlene

    2001-01-01

    Two experiments examined relation between age-related changes in retention and age-related changes in the misinformation effect. Found large age-related retention differences when participants were interviewed immediately and after 1 day, but after 6 weeks, differences were minimal. Exposure to misleading information increased commission errors.…

  10. Neuroanatomical Substrates of Age-Related Cognitive Decline

    ERIC Educational Resources Information Center

    Salthouse, Timothy A.

    2011-01-01

    There are many reports of relations between age and cognitive variables and of relations between age and variables representing different aspects of brain structure and a few reports of relations between brain structure variables and cognitive variables. These findings have sometimes led to inferences that the age-related brain changes cause the…

  11. Age related diastolic function in amateur athletes.

    PubMed

    Santoro, Amato; Alvino, Federico; Antonelli, Giovanni; Cassano, Francesco Emmanuel; De Vito, Raffaella; Cameli, Matteo; Mondillo, Sergio

    2015-03-01

    Diastolic function get worse with increasing age. Aim of this study was to investigate the impact of aerobic training on diastolic function with increasing age with speckle tracking echocardiography. We enrolled 125 amateur swimmers (AG), divided in three groups at increasing age: young athletes, adult athletes (AG2), old athletes (AG3). We enrolled 95 sedentary controls (SG) age-matched with athletes and divided into three groups: young sedentary group, adult sedentary group (SG2) and old sedentary group (SG3). AG had better diastolic function than SG. AG showed lower left ventricular twist than controls. E/A ratio got worse at increasing of age in all population (r = -0.34; p < 0.001); particularly in SG2 and SG3 there was a worsening of diastolic function respect to diastolic function of AG2 and AG3; in fact E/A ratio decreased with aging. Furthermore in SG E/A ratio showed a linear correlation with age (r = -0.54; p < 0.001); in AG this correlation was lost. Therefore the training and age were independent predictor of E/A (respectively β = -0.27; p = 0.004; β = -0.24, p = 0.008). Regular and aerobic training may minimize aging changes of diastolic function. This training-effect may play a key role to preserve diastolic filling in older athletes. PMID:25795025

  12. Divergent Thinking and Age-Related Changes

    ERIC Educational Resources Information Center

    Palmiero, Massimiliano; Di Giacomo, Dina; Passafiume, Domenico

    2014-01-01

    Aging can affect cognition in different ways. The extent to which aging affects divergent thinking is unclear. In this study, younger and older adults were compared at the performance on the Torrance Test of Creative Thinking in visual and verbal form. Results showed that older adults can think divergently as younger participants, although they…

  13. Growth factors, aging and age-related diseases.

    PubMed

    Balasubramanian, Priya; Longo, Valter D

    2016-06-01

    Simple organisms including yeast and flies with mutations in the IGF-1 and Tor-S6K pathways are dwarfs, are highly protected from toxins, and survive up to 3 times longer. Similarly, dwarf mice with deficiencies in the growth hormone-IGF-I axis are also long lived and protected from diseases. We recently reported that humans with Growth Hormone Receptor Deficiency (GHRD) rarely develop cancer or diabetes. These findings are in agreement with the effect of defects in the Tor-S6K pathways in causing dwarfism and protection of DNA. Because protein restriction reduces both GHR-IGF-1 axis and Tor-S6K activity, we examined links between protein intake, disease, and mortality in over 6000 US subjects in the NHANES CDC database. Respondents aged 50-65 reporting a high protein intake displayed an increase in IGF-I levels, a 75% increased risk of overall mortality and a 3-4 fold increased risk of cancer mortality in agreement with findings in mouse experiments. These studies point to a conserved link between proteins and amino acids, GHR-IGF-1/insulin, Tor-S6k signaling, aging, and diseases. PMID:26883276

  14. Degradation mechanisms of cable insulation materials during radiation-thermal ageing in radiation environment

    NASA Astrophysics Data System (ADS)

    Seguchi, Tadao; Tamura, Kiyotoshi; Ohshima, Takeshi; Shimada, Akihiko; Kudoh, Hisaaki

    2011-02-01

    Radiation and thermal degradation of ethylene-propylene rubber (EPR) and crosslinked polyethylene (XLPE) as cable insulation materials were investigated by evaluating tensile properties, gel-fraction, and swelling ratio, as well as by the infrared (FTIR) analysis. The activation energy of thermal oxidative degradation changed over the range 100-120 °C for both EPR and XLPE. This may be attributed to the fact that the content of an antioxidant used as the stabilizer for polymers decreases by evaporation during thermal ageing at high temperatures. The analysis of antioxidant content and oxidative products in XLPE as a model sample showed that a small amount of antioxidant significantly reduced the extent of thermal oxidation, but was not effective for radiation induced oxidation. The changes in mechanical properties were well reflected by the degree of oxidation. A new model of polymer degradation mechanisms was proposed where the degradation does not take place by chain reaction via peroxy radical and hydro-peroxide. The role of the antioxidant in the polymer is the reduction of free radical formation in the initiation step in thermal oxidation, and it could not stop radical reactions for either radiation or thermal oxidation.

  15. Time-dependent degradation of titanium osteoconductivity: an implication of biological aging of implant materials.

    PubMed

    Att, Wael; Hori, Norio; Takeuchi, Masato; Ouyang, Jianyong; Yang, Yang; Anpo, Masakazu; Ogawa, Takahiro

    2009-10-01

    The shelf life of implantable materials has rarely been addressed. We determined whether osteoconductivity of titanium is stable over time. Rat bone marrow-derived osteoblasts were cultured on new titanium disks (immediately after acid-etching), 3-day-old (stored after acid-etching for 3 days in dark ambient conditions), 2-week-old, and 4-week-old disks. Protein adsorption capacity, and osteoblast migration, attachment, spread, proliferation and mineralization decreased substantially on old titanium surfaces in an age-dependent manner. When the 4-week-old implants were placed into rat femurs, the biomechanical strength of bone-titanium integration was less than half that for newly processed implants at the early healing stage. More than 90% of the new implant surface was covered by newly generated bone compared to 58% for 4-week-old implants. This time-dependent biological degradation was also found for machined and sandblasted titanium surfaces and was associated with progressive accumulation of hydrocarbon on titanium surfaces. The new surface could attract osteoblasts even under a protein-free condition, but its high bioactivity was abrogated by masking the surface with anions. These results uncover an aging-like time-dependent biological degradation of titanium surfaces from bioactive to bioinert. We also suggest possible underlying mechanisms for this biological degradation that provide new insights into how we could inadvertently lose, and conversely, maximize the osteoconductivity of titanium-based implant materials.

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

    PubMed Central

    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

  17. Aging is not a disease: distinguishing age-related macular degeneration from aging.

    PubMed

    Ardeljan, Daniel; Chan, Chi-Chao

    2013-11-01

    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.

  18. Degradation and formation of polycyclic aromatic compounds during bioslurry treatment of an aged gasworks soil.

    PubMed

    Lundstedt, Staffan; Haglund, Peter; Oberg, Lars

    2003-07-01

    The goals of this study were to investigate the relative degradation rates of polycyclic aromatic compounds (PACs) in contaminated soil, and to assess whether persistent oxidation products are formed during their degradation. Samples were taken on five occasions during a pilot-scale bioslurry treatment of soil from a former gasworks site. More than 100 PACs were identified in the soil, including unsubstituted polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs (alkyl-PAHs), heterocyclic PACs, and oxygenated PAHs (oxy-PAHs), such as ketones, quinones, and coumarins. During the treatment, the low molecular weight PAHs and heterocyclics were degraded faster than the high molecular weight compounds. The unsubstituted PAHs also appear to have degraded more quickly than the corresponding alkyl-PAHs and nitrogen-containing heterocyclics. No new oxidation products that were not present in the untreated soil were identified after the soil treatment. However, oxy-PAHs that were present in the untreated soil were generally degraded more slowly than the parent compounds, suggesting that they were formed during the treatment or that they are more persistent. Two oxidation products, 1-acenaphthenone and 4-oxapyrene-5-one, were found at significantly higher concentrations at the end of the study. Because oxy-PAHs can be acutely toxic, mutagenic, or carcinogenic, we suggest that this group of compounds should also be monitored during the treatment of PAH-contaminated soil. PMID:12836964

  19. Aging Changes in Retinal Microglia and their Relevance to Age-related Retinal Disease.

    PubMed

    Ma, Wenxin; Wong, Wai T

    2016-01-01

    Age-related retinal diseases, such as age-related macular degeneration (AMD) and glaucoma, contain features of chronic retinal inflammation that may promote disease progression. However, the relationship between aging and neuroinflammation is unclear. Microglia are long-lived, resident immune cells of the retina, and mediate local neuroinflammatory reactions. We hypothesize that aging changes in microglia may be causally linked to neuroinflammatory changes underlying age-dependent retinal diseases. Here, we review the evidence for (1) how the retinal microglial phenotype changes with aging, (2) the factors that drive microglial aging in the retina, and (3) aging-related changes in microglial gene expression. We examine how these aspects of microglial aging changes may relate to pathogenic mechanisms of immune dysregulation driving the progression of age-related retinal disease. These relationships can highlight microglial aging as a novel target for the prevention and treatment of retinal disease.

  20. Age-related elemental change in bones

    NASA Astrophysics Data System (ADS)

    Wang, C.; Eisa, M. H.; Jin, W.; Shen, H.; Mi, Y.; Gao, J.; Zhou, Y.; Yao, H.; Zhao, Y.

    2008-04-01

    To investigate age dependence of the bone element contents and structure, lumbar and femur from Sprague-Dawley (SD) rats were chosen for their more susceptibility to fracture. These rats were divided into to 5 age groups: 1, 4, 7, 11 and 25 month-age, corresponding human beings from the young to the old. The elements contents were detected by external Proton Induced X-ray emission (PIXE) technique. X-ray Absorption Fine Structure (XAFS) method was also applied to obtain information about calcium (Ca) and phosphor (P) structure. It was found that Ca content, Ca/P ratio, valance state of Ca and P and their coordinate structure remains unaltered with age variance, whereas the content of strontium (Sr) was significantly decreasing. Sr concentration may provide a new parameter for diagnosis of bone disorder.

  1. 8 Areas of Age-Related Change

    MedlinePlus

    ... please turn Javascript on. Photo: PhotoDisc 1. Brain: Memory and Alzheimer's Disease (AD) As adults age, many ... sign of Alzheimer's Disease (AD). In the past, memory loss and confusion were accepted as just part ...

  2. Age Related Changes in Autonomic Functions

    PubMed Central

    Amir, Mohammed; Pakhare, Abhijit; Rathi, Preeti; Chaudhary, Lalita

    2016-01-01

    Introduction Autonomic Nervous System (ANS) imbalance may trigger or enhance pathology in different organ systems that varies in different age groups hence objective of present study was to evaluate association of different Age-groups with autonomic functions. Materials and Methods A cross-sectional study was conducted in 62 healthy volunteers in Department of Physiology LLRM Medical College Meerut, India. Volunteers were divided into three groups as younger (15-45 years), middle (45-60) and elder age (above 60), Autonomic functions were tested in three domains viz. Cardio-vagal, adrenergic and sudomotor functions. Numerical data was summarized as mean and standard deviation and categorical data as count and percentage. ANOVA and Chi-square test were used to find difference among groups, p<0.05 was considered statistically significant. Results Mean ± standard deviation OHT(Orthostatic Hypotension Test) among of younger, middle and elder age groups were 8.80±2.28, 13.40±4.64 and 21.82±6.04 respectively which represent decrease in sympathetic functions with age (p<0.001). Cardio-vagal or parasympathetic responses indicated by DBT (Deep Breathing Test) Valsalva and 30:15 ratio of HR response to standing tests has shown statistically significant (p<0.001) decrease in mean response with increasing age. Sudomotor response appeared normal in younger and middle group but was interrupted in more than half of elderly people (p<0.001). Conclusion Sympathetic responses & para-sympathetic responses have shown the significant decline with increasing age group. Sudomotor responses were partially interrupted in elderly age group. PMID:27134865

  3. High-resolution photoelectron spectroscopy study of degradation of rubber-to-brass adhesion by thermal aging

    NASA Astrophysics Data System (ADS)

    Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Izumi, Yudai; Muro, Takayuki; Komatsu, Takayuki

    2013-03-01

    High resolution photoelectron spectroscopy is utilized to investigate degradation of rubber-to-brass adhesion by thermal aging. Special attention is given to the role of water in the environment surrounding brass-embedded rubber so that three aging processes are employed; hydrothermal aging, moist-heat aging and dry-heat aging. All aging processes lead to the decrease in the amount of S at the rubber/brass interface. This desulfurization accompanies the decrease in the ratio of CuxS (x ≃ 2) to CuS, i.e., CuxS/CuS, and the increase in the amount of ZnO, Zn(OH)2 and ZnS, all of which are key factors for degradation of adhesion. The changes in the chemical composition are enhanced by water in the surrounding environment during the aging treatments, indicating that the water molecules accelerate degradation of rubber-to-brass adhesion.

  4. Relative Age Effect in Masters Sports: Replication and Extension

    ERIC Educational Resources Information Center

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

    2009-01-01

    The relative age effect refers to the performance-related advantage of being born early in a cohort or selection year. Until recently it was unknown whether the relative age effect generalizes across the lifespan. Medic, Starkes, and Young (2007) reasoned that the 5-year age categories that are widely used in masters-level sports to organize…

  5. Analysis of the degradation and aging of a commercial photovoltaic installation

    NASA Astrophysics Data System (ADS)

    Bradley, Alexander; Hamzavy, Babak; Gambogi, William

    2014-10-01

    Simple and accurate methods are needed to monitor and assess PV systems. It is important to characterize and understand the value of the system with regard to safety and performance (including seasonal and geographical variations) as well as operation and maintenance. This documentation is becoming necessary for the secondary or resale value of PV assets. We report the results from an analysis of a commercial c-Si PV array owned and operated by DuPont. Our technical assessment consists of remote monitoring, field inspection with visual examination and thermal imaging to create a pareto chart of degradation modes, and laboratory analysis. A comparison of remote monitoring and site inspection is presented as well as laboratory analysis (nondestructive and destructive test methods) of modules removed from the service environment. Degradation modes and quality issues became evident as electrical, optical, physical or chemical defects developed with system age. This evaluation provided system data, documented quality issues, and quantified the cost of ownership.

  6. Small impact craters in the lunar regolith - Their morphologies, relative ages, and rates of formation

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Boyce, J. M.; Hahn, D. A.

    1980-01-01

    The size frequency distributions, relative ages, and absolute age determination of lunar impact craters ranging in diameter from 1 to 100 m are discussed in relation to present-day and past impact rates. The size frequency distributions of craters produced by impacts on the lunar surface and of craters remaining after degradation with time and later impacts are examined, together with the steady state frequency curves for various crater morphologies. Relations between the relative ages of craters, their morphologies and their diameters are discussed, and the calibration of this kind of relationship with absolute crater ages by the location of individual craters with known absolute ages, diameters and frequency distribution statistics is considered. Estimates of present and past cratering rates based on crater size-frequency distributions are presented which suggest that the rate of impacting objects producing small lunar craters could have been constant over the last 100 million years.

  7. Age-related differences in associative memory: the role of sensory decline.

    PubMed

    Naveh-Benjamin, Moshe; Kilb, Angela

    2014-09-01

    Numerous studies show age-related decline in episodic memory. One of the explanations for this decline points to older adults' deficit in associative memory, reflecting the difficulties they have in binding features of episodes into cohesive entities and retrieving these bindings. Here, we evaluate the degree to which this deficit may be mediated by sensory loss associated with increased age. In 2 experiments, young adults studied word pairs that were degraded at encoding either visually (Experiment 1) or auditorily (Experiment 2). We then tested their memory for both the component words and the associations with recognition tests. For both experiments, young adults under nondegraded conditions showed an advantage in associative over item memory, relative to a group of older adults. In contrast, under perceptually degraded conditions younger adults performed similarly to the older adults who were tested under nondegraded conditions. More specifically, under perceptual degradation, young adults' associative memory declined and their component memory improved somewhat, resulting in an associative deficit, similar to that shown by older adults. This evidence is consistent with a sensory acuity decline in old age being one mediator in the associative deficit of older adults. These results broaden our understanding of age-related memory changes and how sensory and cognitive processes interact to shape these changes. The theoretical implications of these results are discussed with respect to mechanisms underlying age-related changes in episodic memory and resource tradeoffs in the encoding of component and associative memory.

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

    ERIC Educational Resources Information Center

    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…

  9. COMPONENT DEGRADATION SUSCEPTIBILITIES AS THE BASES FOR MODELING REACTOR AGING RISK

    SciTech Connect

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2010-07-18

    The extension of nuclear power plant operating licenses beyond 60 years in the United States will be necessary if we are to meet national energy needs while addressing the issues of carbon and climate. Characterizing the operating risks associated with aging reactors is problematic because the principal tool for risk-informed decision-making, Probabilistic Risk Assessment (PRA), is not ideally-suited to addressing aging systems. The components most likely to drive risk in an aging reactor - the passives - receive limited treatment in PRA, and furthermore, standard PRA methods are based on the assumption of stationary failure rates: a condition unlikely to be met in an aging system. A critical barrier to modeling passives aging on the wide scale required for a PRA is that there is seldom sufficient field data to populate parametric failure models, and nor is there the availability of practical physics models to predict out-year component reliability. The methodology described here circumvents some of these data and modeling needs by using materials degradation metrics, integrated with conventional PRA models, to produce risk importance measures for specific aging mechanisms and component types. We suggest that these measures have multiple applications, from the risk-screening of components to the prioritization of materials research.

  10. Statins for age-related macular degeneration

    PubMed Central

    Gehlbach, Peter; Li, Tianjing; Hatef, Elham

    2016-01-01

    Background Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries. Recent epidemiologic, genetic, and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD. Objectives The objective of this review was to examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and progression of AMD. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to June 2014), PubMed (January 1946 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 June 2014. Selection criteria We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD. Data collection and analysis We used standard methodological procedures expected by The Cochrane Collaboration. Two authors independently evaluated the search results against the selection criteria, abstracted data, and assessed risk of bias. We did not perform meta-analysis due to heterogeneity in the interventions and outcomes among the

  11. Statins for age-related macular degeneration

    PubMed Central

    Gehlbach, Peter; Li, Tianjing; Hatef, Elham

    2016-01-01

    Background Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries. Recent epidemiologic, genetic, and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD. Objectives The objective of this review was to examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and progression of AMD. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to June 2014), PubMed (January 1946 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 June 2014. Selection criteria We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD. Data collection and analysis We used standard methodological procedures expected by The Cochrane Collaboration. Two authors independently evaluated the search results against the selection criteria, abstracted data, and assessed risk of bias. We did not perform meta-analysis due to heterogeneity in the interventions and outcomes among the

  12. The relevance of aging-related changes in brain function to rehabilitation in aging-related disease

    PubMed Central

    Crosson, Bruce; McGregor, Keith M.; Nocera, Joe R.; Drucker, Jonathan H.; Tran, Stella M.; Butler, Andrew J.

    2015-01-01

    The effects of aging on rehabilitation of aging-related diseases are rarely a design consideration in rehabilitation research. In this brief review we present strong coincidental evidence from these two fields suggesting that deficits in aging-related disease or injury are compounded by the interaction between aging-related brain changes and disease-related brain changes. Specifically, we hypothesize that some aphasia, motor, and neglect treatments using repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) in stroke patients may address the aging side of this interaction. The importance of testing this hypothesis and addressing the larger aging by aging-related disease interaction is discussed. Underlying mechanisms in aging that most likely are relevant to rehabilitation of aging-related diseases also are covered. PMID:26074807

  13. Spider silk aging: initial improvement in a high performance material followed by slow degradation.

    PubMed

    Agnarsson, Ingi; Boutry, Cecilia; Blackledge, Todd A

    2008-10-01

    Spider silk possesses a unique combination of high tensile strength and elasticity resulting in extraordinarily tough fibers, compared with the best synthetic materials. However, the potential application of spider silk and biomimetic fibers depends upon retention of their high performance under a variety of conditions. Here, we report on changes in the mechanical properties of dragline and capture silk fibers from several spider species over periods up to 4 years of benign aging. We find an improvement in mechanical performance of silk fibers during the first year of aging. Fibers rapidly decrease in diameter, suggesting an increase in structural alignment and organization of molecules. One-year old silk also is stiffer and has higher stress at yield than fresh silk, whereas breaking force, elasticity, and toughness either improve or are unaffected by early aging. However, 4-year old silk shows signs of degradation as the breaking load, elasticity, and toughness are all lower than in fresh silk. Aging, however, does not reduce the tensile strength of silk. These data suggest initially rapid reorganization and tighter packaging of molecules within the fiber, followed by longer-term decomposition. We hypothesize that possibly the breakdown of amino acids via emission of ammonia gas, as is seen in long-term aging of museum silkworm fabrics, may contribute. Degradation of spider silk under benign conditions may be a concern for efforts to construct and utilize biomimetic silk analogs. However, our findings suggest an initial improvement in mechanical performance and that even old spider silk still retains impressive mechanical performance. PMID:18626974

  14. AGE-RELATED SUSCEPTIBILITY: A GENOMICS APPROACH.

    EPA Science Inventory

    By the year 2030 more than 70 million Americans will be over the age of 65. These older adults are a subpopulation that may have special susceptibility to toxic insult due to critical characteristics of their life-stage. Current EPA testing guidelines do not identify the elderl...

  15. Age-Related Changes in Visual Pseudoneglect

    ERIC Educational Resources Information Center

    Schmitz, Remy; Peigneux, Philippe

    2011-01-01

    Pseudoneglect is a slight but consistent leftward attentional bias commonly observed in healthy young populations, purportedly explained by right hemispheric dominance. It has been suggested that normal aging might be associated with a decline of the right hemisphere. According to this hypothesis, a few studies have shown that elderly tend to…

  16. Aging, Obsolescence, Impact, Growth, and Utilization: Definitions and Relations.

    ERIC Educational Resources Information Center

    Egghe, Leo; Rousseau, Ronald

    2000-01-01

    Examines the notions of aging, obsolescence, impact, growth, utilization, and related concepts in information science. Illustrates the influence of growth on aging, how aging rates can be corrected for growth, and the relation with impact measures. Presents mathematical results, practical calculations, and examples of these concepts. Gives a brief…

  17. Age-related forgetting in locomotor adaptation

    PubMed Central

    Malone, Laura A.; Bastian, Amy J.

    2016-01-01

    The healthy aging process affects the ability to learn and remember new facts and tasks. Prior work has shown that motor learning can be adversely affected by non-motor deficits, such as time. Here we investigated how age, and a dual task influence the learning and forgetting of a new walking pattern. We studied healthy younger (<30 yo) and older adults (>50 yo) as they alternated between 5-minute bouts of split-belt treadmill walking and resting. Older subjects learned a new walking pattern at the same rate as younger subjects, but forgot some of the new pattern during the rest breaks. We tested if forgetting was due to reliance on a cognitive strategy that was not fully engaged after rest breaks. When older subjects performed a dual cognitive task to reduce strategic control of split-belt walking, their adaptation rate slowed, but they still forgot much of the new pattern during the rest breaks. Our results demonstrate that the healthy aging process weakens motor memories during rest breaks and that this phenomenon cannot be explained solely by reliance on a conscious strategy in older adults. PMID:26589520

  18. Comparison of Quantifiler(®) Trio and InnoQuant™ human DNA quantification kits for detection of DNA degradation in developed and aged fingerprints.

    PubMed

    Goecker, Zachary C; Swiontek, Stephen E; Lakhtakia, Akhlesh; Roy, Reena

    2016-06-01

    The development techniques employed to visualize fingerprints collected from crime scenes as well as post-development ageing may result in the degradation of the DNA present in low quantities in such evidence samples. Amplification of the DNA samples with short tandem repeat (STR) amplification kits may result in partial DNA profiles. A comparative study of two commercially available quantification kits, Quantifiler(®) Trio and InnoQuant™, was performed on latent fingerprint samples that were either (i) developed using one of three different techniques and then aged in ambient conditions or (ii) undeveloped and then aged in ambient conditions. The three fingerprint development techniques used were: cyanoacrylate fuming, dusting with black powder, and the columnar-thin-film (CTF) technique. In order to determine the differences between the expected quantities and actual quantities of DNA, manually degraded samples generated by controlled exposure of DNA standards to ultraviolet radiation were also analyzed. A total of 144 fingerprint and 42 manually degraded DNA samples were processed in this study. The results indicate that the InnoQuant™ kit is capable of producing higher degradation ratios compared to the Quantifiler(®) Trio kit. This was an expected result since the degradation ratio is a relative value specific for a kit based on the length and extent of amplification of the two amplicons that vary from one kit to the other. Additionally, samples with lower concentrations of DNA yielded non-linear relationships of degradation ratio with the duration of aging, whereas samples with higher concentrations of DNA yielded quasi-linear relationships. None of the three development techniques produced a noticeably different degradation pattern when compared to undeveloped fingerprints, and therefore do not impede downstream DNA analysis.

  19. Low Calorie Diet Affects Aging-Related Factors

    MedlinePlus

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

  20. New Clues to Age-Related Hearing Loss

    MedlinePlus

    ... gov/news/fullstory_161359.html New Clues to Age-Related Hearing Loss Older people's brains have a ... the brain's ability to process speech declines with age. For the study, Alessandro Presacco and colleagues divided ...

  1. Formation kinetics of copper-related light-induced degradation in crystalline silicon

    SciTech Connect

    Lindroos, J. Savin, H.

    2014-12-21

    Light-induced degradation (LID) is a deleterious effect in crystalline silicon, which is considered to originate from recombination-active boron-oxygen complexes and/or copper-related defects. Although LID in both cases appears as a fast initial decay followed by a second slower degradation, we show that the time constant of copper-related degradation increases with increasing boron concentration in contrast to boron-oxygen LID. Temperature-dependent analysis reveals that the defect formation is limited by copper diffusion. Finally, interface defect density measurements confirm that copper-related LID is dominated by recombination in the wafer bulk.

  2. Translation by Ribosomes with mRNA Degradation: Exclusion Processes on Aging Tracks

    NASA Astrophysics Data System (ADS)

    Nagar, Apoorva; Valleriani, Angelo; Lipowsky, Reinhard

    2011-12-01

    We investigate the role of degradation of mRNA on protein synthesis using the totally asymmetric simple exclusion process (TASEP) as the underlying model for ribosome dynamics. mRNA degradation has a strong effect on the lifetime distribution of the mRNA, which in turn affects polysome statistics such as the number of ribosomes present on an mRNA strand of a given size. An average over mRNA of all ages is equivalent to an average over possible configurations of the corresponding TASEP—both before steady state and in steady state. To evaluate the relevant quantities for the translation problem, we first study the approach towards steady state of the TASEP, starting with an empty lattice representing an unloaded mRNA. When approaching the high density phase, the system shows two distinct phases with the entry and exit boundaries taking control of the density at their respective ends in the second phase. The approach towards the maximal current phase exhibits the surprising property that the ribosome entry flux can exceed the maximum possible steady state value. In all phases, the averaging over the mRNA age distribution shows a decrease in the average ribosome density profile as a function of distance from the entry boundary. For entry/exit parameters corresponding to the high density phase of TASEP, the average ribosome density profile also has a maximum near the exit end.

  3. Relationship of Bacterial Richness to Organic Degradation Rate and Sediment Age in Subseafloor Sediment

    PubMed Central

    Walsh, Emily A.; Kirkpatrick, John B.; Pockalny, Robert; Sauvage, Justine; Spivack, Arthur J.; Murray, Richard W.; Sogin, Mitchell L.

    2016-01-01

    ABSTRACT Subseafloor sediment hosts a large, taxonomically rich, and metabolically diverse microbial ecosystem. However, the factors that control microbial diversity in subseafloor sediment have rarely been explored. Here, we show that bacterial richness varies with organic degradation rate and sediment age. At three open-ocean sites (in the Bering Sea and equatorial Pacific) and one continental margin site (Indian Ocean), richness decreases exponentially with increasing sediment depth. The rate of decrease in richness with increasing depth varies from site to site. The vertical succession of predominant terminal electron acceptors correlates with abundance-weighted community composition but does not drive the vertical decrease in richness. Vertical patterns of richness at the open-ocean sites closely match organic degradation rates; both properties are highest near the seafloor and decline together as sediment depth increases. This relationship suggests that (i) total catabolic activity and/or electron donor diversity exerts a primary influence on bacterial richness in marine sediment and (ii) many bacterial taxa that are poorly adapted for subseafloor sedimentary conditions are degraded in the geologically young sediment, where respiration rates are high. Richness consistently takes a few hundred thousand years to decline from near-seafloor values to much lower values in deep anoxic subseafloor sediment, regardless of sedimentation rate, predominant terminal electron acceptor, or oceanographic context. IMPORTANCE Subseafloor sediment provides a wonderful opportunity to investigate the drivers of microbial diversity in communities that may have been isolated for millions of years. Our paper shows the impact of in situ conditions on bacterial community structure in subseafloor sediment. Specifically, it shows that bacterial richness in subseafloor sediment declines exponentially with sediment age, and in parallel with organic-fueled oxidation rate. This result

  4. Health habits in relation to aging.

    PubMed

    McGlone, F B; Kick, E

    1978-11-01

    A review of the literature and a study of 52 patients of the 80+ age group confirmed the premise that good health habits have a positive effect on the quantity and quality of life. Not all persons can live beyond 80, but those who do can lead a better life if they live properly. A profile of these 52 subjects aged 80 or older revealed that they were of average size or thin, and of a happy temperament; they ate well and regularly, slept adequately, avoided excessive amounts of alcohol, did not smoke, used drugs sparingly, and led an active life, physically and mentally. Also, it was apparent that the rugged elderly can withstand the impact of a major illness or a surgical operation with associated anesthesia. The following factors are important for longevity: 1) pick the right grandparents, 2) keep active physically and mentally, 3) eat properly, 4) stay thin, 5) drink alcohol moderately if at all, and 6) do not smoke. PMID:701699

  5. Age-related disruption of autophagy in dermal fibroblasts modulates extracellular matrix components

    SciTech Connect

    Tashiro, Kanae; Shishido, Mayumi; Fujimoto, Keiko; Hirota, Yuko; Yo, Kazuyuki; Gomi, Takamasa; Tanaka, Yoshitaka

    2014-01-03

    Highlights: •Autophagosomes accumulate in aged dermal fibroblasts. •Autophagic degradation is impaired in aged dermal fibroblasts. •Autophagy disruption affects extracellular matrix components in dermal fibroblasts. -- Abstract: Autophagy is an intracellular degradative system that is believed to be involved in the aging process. The contribution of autophagy to age-related changes in the human skin is unclear. In this study, we examined the relationship between autophagy and skin aging. Transmission electron microscopy and immunofluorescence microscopy analyses of skin tissue and cultured dermal fibroblasts derived from women of different ages revealed an increase in the number of nascent double-membrane autophagosomes with age. Western blot analysis showed that the amount of LC3-II, a form associated with autophagic vacuolar membranes, was significantly increased in aged dermal fibroblasts compared with that in young dermal fibroblasts. Aged dermal fibroblasts were minimally affected by inhibition of autophagic activity. Although lipofuscin autofluorescence was elevated in aged dermal fibroblasts, the expression of Beclin-1 and Atg5—genes essential for autophagosome formation—was similar between young and aged dermal fibroblasts, suggesting that the increase of autophagosomes in aged dermal fibroblasts was due to impaired autophagic flux rather than an increase in autophagosome formation. Treatment of young dermal fibroblasts with lysosomal protease inhibitors, which mimic the condition of aged dermal fibroblasts with reduced autophagic activity, altered the fibroblast content of type I procollagen, hyaluronan and elastin, and caused a breakdown of collagen fibrils. Collectively, these findings suggest that the autophagy pathway is impaired in aged dermal fibroblasts, which leads to deterioration of dermal integrity and skin fragility.

  6. Age Related Decline in Postural Control Mechanisms.

    ERIC Educational Resources Information Center

    Stelmach, George E.; And Others

    1989-01-01

    Studied voluntary and reflexive mechanisms of postural control of young (N=8) and elderly (N=8) adults through measurement of reflexive reactions to large-fast and small-slow ankle rotation postural disturbances. Found reflexive mechanisms relatively intact for both groups although elderly appeared more disadvantaged when posture was under the…

  7. Mechanisms of enzymatic degradation of amyloid Beta microfibrils generating nanofilaments and nanospheres related to cytotoxicity.

    PubMed

    Numata, Keiji; Kaplan, David L

    2010-04-20

    Amyloid beta (Abeta) fibrils are found in the brain tissue of persons with Alzheimer's disease (AD), where they accumulate as plaques. One way to reduce the level of accumulation of Abeta in the brain and potentially treat AD is with Abeta-degrading enzymes such as neprilysin (NEP) and insulin-degrading enzyme (IDE). However, enzymatic responses and degradation mechanisms of Abeta fibrils (crystalline-state Abeta) have not been investigated, particularly with respect to how to avoid cytotoxicity of the degradation products to neuronal cells. Thus, insight into mechanisms of enzymatic degradation of Abeta fibrils would be instructive as a route to elucidating different structural features related to degradation and to cytotoxicity. We report mechanisms of enzymatic degradation of Abeta with cross-beta structures and show the series of steps involved in the digestion of Abeta microfibrils to nanospheres or nanofilaments by protease XIV or alpha-chymotrypsin, respectively. These degradation products, which contained almost the same secondary structures, exhibited different cytotoxicities, indicating that relationships between nanoassembled structures and cytotoxicity of Abeta peptides are more significant than the beta-sheet content. In addition, the enzymatic digestion at the Lys28 loop region linking the two beta-sheets in Abeta fibrils is suggested as a key target related to cytotoxicity, a feature that can be selectively targeted on the basis of the choice of protease.

  8. Relative response factor determination of β-artemether degradants by a dry heat stress approach.

    PubMed

    De Spiegeleer, Bart M J; D'Hondt, Matthias; Vangheluwe, Elien; Vandercruyssen, Kirsten; De Spiegeleer, Bart V I; Jansen, Herwig; Koijen, Ilse; Van Gompel, Jacques

    2012-11-01

    During the stability evaluation of β-artemether containing finished drug products, a consistent and disproportional increase in the UV-peak areas of β-artemether degradation products, when compared to the peak area decline of β-artemether itself, was observed. This suggested that the response factors of the formed β-artemether degradants were significantly higher than β-artemether. Dry heat stressing of β-artemether powder, as a single compound, using different temperatures (125-150 °C), times (10-90 min) and environmental conditions (neutral, KMnO(4) and zinc), resulted in the formation of 17 degradants. The vast majority of degradants seen during the long-term and accelerated ICH stability study of the drug product, were also observed here. The obtained stress results allowed the calculation of the overall average relative response factor (RRF) of β-artemether degradants, i.e. 21.2, whereas the individual RRF values of the 9 most prominent selected degradants ranged from 4.9 to 42.4. Finally, Ames tests were performed on β-artemether as well as a representative stressed sample mixture, experimentally assessing their mutagenic properties. Both were found to be negative, suggesting no mutagenicity problems of the degradants at high concentrations. Our general approach and specific results solve the developmental quality issue of mass balance during stability studies and the related genotoxicity concerns of the key antimalarial drug β-artemether and its degradants. PMID:22770733

  9. Relative response factor determination of β-artemether degradants by a dry heat stress approach.

    PubMed

    De Spiegeleer, Bart M J; D'Hondt, Matthias; Vangheluwe, Elien; Vandercruyssen, Kirsten; De Spiegeleer, Bart V I; Jansen, Herwig; Koijen, Ilse; Van Gompel, Jacques

    2012-11-01

    During the stability evaluation of β-artemether containing finished drug products, a consistent and disproportional increase in the UV-peak areas of β-artemether degradation products, when compared to the peak area decline of β-artemether itself, was observed. This suggested that the response factors of the formed β-artemether degradants were significantly higher than β-artemether. Dry heat stressing of β-artemether powder, as a single compound, using different temperatures (125-150 °C), times (10-90 min) and environmental conditions (neutral, KMnO(4) and zinc), resulted in the formation of 17 degradants. The vast majority of degradants seen during the long-term and accelerated ICH stability study of the drug product, were also observed here. The obtained stress results allowed the calculation of the overall average relative response factor (RRF) of β-artemether degradants, i.e. 21.2, whereas the individual RRF values of the 9 most prominent selected degradants ranged from 4.9 to 42.4. Finally, Ames tests were performed on β-artemether as well as a representative stressed sample mixture, experimentally assessing their mutagenic properties. Both were found to be negative, suggesting no mutagenicity problems of the degradants at high concentrations. Our general approach and specific results solve the developmental quality issue of mass balance during stability studies and the related genotoxicity concerns of the key antimalarial drug β-artemether and its degradants.

  10. Relative degradation of near infrared avalanche photodiodes from proton irradiation

    NASA Technical Reports Server (NTRS)

    Becker, Heidi; Johnston, Allan H.

    2004-01-01

    InGaAs and Ge avalanche photodiodes are compared for the effects of 63-MeV protons on dark current. Differences in displacement damage factors are discussed as they relate to structural differences between devices.

  11. Slowing Down: Age-Related Neurobiological Predictors of Processing Speed

    PubMed Central

    Eckert, Mark A.

    2011-01-01

    Processing speed, or the rate at which tasks can be performed, is a robust predictor of age-related cognitive decline and an indicator of independence among older adults. This review examines evidence for neurobiological predictors of age-related changes in processing speed, which is guided in part by our source based morphometry findings that unique patterns of frontal and cerebellar gray matter predict age-related variation in processing speed. These results, together with the extant literature on morphological predictors of age-related changes in processing speed, suggest that specific neural systems undergo declines and as a result slow processing speed. Future studies of processing speed – dependent neural systems will be important for identifying the etiologies for processing speed change and the development of interventions that mitigate gradual age-related declines in cognitive functioning and enhance healthy cognitive aging. PMID:21441995

  12. Age-Related Differences in Idiom Production in Adulthood

    ERIC Educational Resources Information Center

    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…

  13. Age-Related Differences in the Production of Textual Descriptions

    ERIC Educational Resources Information Center

    Marini, Andrea; Boewe, Anke; Caltagirone, Carlo; Carlomagno, Sergio

    2005-01-01

    Narratives produced by 69 healthy Italian adults were analyzed for age-related changes of microlinguistic, macrolinguistic and informative aspects. The participants were divided into five age groups (20-24, 25-39, 40-59, 60-74, 75-84). One single-picture stimulus and two cartoon sequences were used to elicit three stories per subject. Age-related…

  14. The Relative Age Effect among Female Brazilian Youth Volleyball Players

    ERIC Educational Resources Information Center

    Okazaki, Fabio H. A.; Keller, Birgit; Fontana, Fabio E.; Gallagher, Jere D.

    2011-01-01

    In sports, the relative age effect (RAE) refers to performance disadvantages of children born late in the competition year compared to those with birthdays soon after the cutoff date. This effect is derived from age grouping, a strategy commonly used in youth sport programs. The purpose of age grouping is to decrease possible cognitive, physical,…

  15. Age at Natural Menopause and Related Factors in Isfahan, Iran

    PubMed Central

    Golshiri, Parastoo; Abdollahzadeh, Mohammad Reza

    2016-01-01

    Objective This study was aimed to evaluate the age at natural menopause and related factors among women in a population based study in 2015 in Isfahan, Islamic Republic of Iran. Methods In this cross-sectional study 960 menopausal women were selected by cluster sampling. Demographic, socioeconomic, lifestyle behavior and reproductive history aspects were collected using a structured questionnaire. Woman and her husband's educational level and occupation with family income were the variables to construct socioeconomic status using principal component analysis. Results Mean and median of natural menopause age were 48.66 and 48 years, respectively. Women body mass index (BMI) more than 30 kg/m2 had significantly higher menopausal age than women with lower BMI (P value = 0.022). The mean of menopausal age was not statistically significant in regard to marital status, physical activity, smoking status, menarche age, age at first pregnancy and history of abortion. Menopause age with pregnancy numbers and age at last pregnancy had a significant positive association. Women with better socioeconomic status had significantly higher natural menopause age. Multiple linear regression shows significant relationship between lower age at menopause with higher age at marriage, higher number of pregnancy and lower socioeconomic status. Conclusion Age at menopause in our studied sample is similar to previous estimates reported for other Iranian populations. Age at marriage, higher number of pregnancy and lower socioeconomic status were the significant factors in relations to age at menopause. PMID:27617243

  16. Age at Natural Menopause and Related Factors in Isfahan, Iran

    PubMed Central

    Golshiri, Parastoo; Abdollahzadeh, Mohammad Reza

    2016-01-01

    Objective This study was aimed to evaluate the age at natural menopause and related factors among women in a population based study in 2015 in Isfahan, Islamic Republic of Iran. Methods In this cross-sectional study 960 menopausal women were selected by cluster sampling. Demographic, socioeconomic, lifestyle behavior and reproductive history aspects were collected using a structured questionnaire. Woman and her husband's educational level and occupation with family income were the variables to construct socioeconomic status using principal component analysis. Results Mean and median of natural menopause age were 48.66 and 48 years, respectively. Women body mass index (BMI) more than 30 kg/m2 had significantly higher menopausal age than women with lower BMI (P value = 0.022). The mean of menopausal age was not statistically significant in regard to marital status, physical activity, smoking status, menarche age, age at first pregnancy and history of abortion. Menopause age with pregnancy numbers and age at last pregnancy had a significant positive association. Women with better socioeconomic status had significantly higher natural menopause age. Multiple linear regression shows significant relationship between lower age at menopause with higher age at marriage, higher number of pregnancy and lower socioeconomic status. Conclusion Age at menopause in our studied sample is similar to previous estimates reported for other Iranian populations. Age at marriage, higher number of pregnancy and lower socioeconomic status were the significant factors in relations to age at menopause.

  17. Metolachlor Sorption and Degradation in Soil Amended with Fresh and Aged Biochars.

    PubMed

    Trigo, Carmen; Spokas, Kurt A; Hall, Kathleen E; Cox, Lucia; Koskinen, William C

    2016-04-27

    Addition of organic amendments such as biochar to soils can influence pesticide sorption-desorption processes and, in turn, the amount of pesticide readily availability for transport and biodegradation. Sorption-desorption processes are affected by both the physical and chemical properties of soils and pesticides, as well as soil-pesticide contact time, or aging. Changes in sorption-desorption of metolachlor with aging in soil amended with three macadamia nut shell biochars aged 0 (BCmac-fr), 1 year (BCmac-1yr), and 2 years (BCmac-2yr) and two wood biochars aged 0 (BCwood-fr) and 5 years (BCwood-5yr) were determined. Apparent sorption coefficient (Kd-app) values increased with incubation time to a greater extent in amended soil as compared to unamended soils; Kd-app increased by 1.2-fold for the unamended soil, 2.0-fold for BCwood-fr, 1.4-fold for BCwood-5yr, 2.4-fold for BCmac-fr, 2.5-fold for BCmac-1yr, and 1.9-fold for BCmac-4yr. The increase in calculated Kd-app value was the result of a 15% decrease in the metolachlor solution concentration extractable with CaCl2 solution with incubation time in soil as compared to a 50% decrease in amended soil with very little change in the sorbed concentration. Differences could possibly be due to diffusion to less accessible or stronger binding sites with time, a faster rate of degradation (in solution and on labile sites) than desorption, or a combination of the two in the amended soils. These data show that transport models would overpredict the depth of movement of metolachlor in soil if effects of aging or biochar amendments are not considered.

  18. Metolachlor Sorption and Degradation in Soil Amended with Fresh and Aged Biochars.

    PubMed

    Trigo, Carmen; Spokas, Kurt A; Hall, Kathleen E; Cox, Lucia; Koskinen, William C

    2016-04-27

    Addition of organic amendments such as biochar to soils can influence pesticide sorption-desorption processes and, in turn, the amount of pesticide readily availability for transport and biodegradation. Sorption-desorption processes are affected by both the physical and chemical properties of soils and pesticides, as well as soil-pesticide contact time, or aging. Changes in sorption-desorption of metolachlor with aging in soil amended with three macadamia nut shell biochars aged 0 (BCmac-fr), 1 year (BCmac-1yr), and 2 years (BCmac-2yr) and two wood biochars aged 0 (BCwood-fr) and 5 years (BCwood-5yr) were determined. Apparent sorption coefficient (Kd-app) values increased with incubation time to a greater extent in amended soil as compared to unamended soils; Kd-app increased by 1.2-fold for the unamended soil, 2.0-fold for BCwood-fr, 1.4-fold for BCwood-5yr, 2.4-fold for BCmac-fr, 2.5-fold for BCmac-1yr, and 1.9-fold for BCmac-4yr. The increase in calculated Kd-app value was the result of a 15% decrease in the metolachlor solution concentration extractable with CaCl2 solution with incubation time in soil as compared to a 50% decrease in amended soil with very little change in the sorbed concentration. Differences could possibly be due to diffusion to less accessible or stronger binding sites with time, a faster rate of degradation (in solution and on labile sites) than desorption, or a combination of the two in the amended soils. These data show that transport models would overpredict the depth of movement of metolachlor in soil if effects of aging or biochar amendments are not considered. PMID:27050383

  19. Tocopherol-mediated modulation of age-related changes in microglial cells: turnover of extracellular oxidized protein material.

    PubMed

    Stolzing, Alexandra; Widmer, Rebecca; Jung, Tobias; Voss, Peter; Grune, Tilman

    2006-06-15

    Proteins accumulate during aging and form insoluble protein aggregates. Microglia are responsible for their removal from the brain. During aging, changes within the microglia might play a crucial role in the malfunctioning of these cells. Therefore, we isolated primary microglial cells from adult rats and compared their activation status and their ability to degrade proteins to that of microglial cells isolated from newborn animals. The ability of adult microglial cells to degrade proteins is substantially decreased. However, the preincubation of microglial cells with vitamin E improves significantly the degradation of such modified proteins. The degradation of proteins from apoptotic vesicles is decreased in microglia isolated from adult rats. This might be the result of a suppression of the CD36 receptor due to vitamin E treatment. We concluded that microglial cells isolated from adult organisms have different metabolic properties and seem to be a more valuable model to study age-related diseases.

  20. Age-Related Neural Oscillation Patterns During the Processing of Temporally Manipulated Speech.

    PubMed

    Rufener, Katharina S; Oechslin, Mathias S; Wöstmann, Malte; Dellwo, Volker; Meyer, Martin

    2016-05-01

    This EEG-study aims to investigate age-related differences in the neural oscillation patterns during the processing of temporally modulated speech. Viewing from a lifespan perspective, we recorded the electroencephalogram (EEG) data of three age samples: young adults, middle-aged adults and older adults. Stimuli consisted of temporally degraded sentences in Swedish-a language unfamiliar to all participants. We found age-related differences in phonetic pattern matching when participants were presented with envelope-degraded sentences, whereas no such age-effect was observed in the processing of fine-structure-degraded sentences. Irrespective of age, during speech processing the EEG data revealed a relationship between envelope information and the theta band (4-8 Hz) activity. Additionally, an association between fine-structure information and the gamma band (30-48 Hz) activity was found. No interaction, however, was found between acoustic manipulation of stimuli and age. Importantly, our main finding was paralleled by an overall enhanced power in older adults in high frequencies (gamma: 30-48 Hz). This occurred irrespective of condition. For the most part, this result is in line with the Asymmetric Sampling in Time framework (Poeppel in Speech Commun 41:245-255, 2003), which assumes an isomorphic correspondence between frequency modulations in neurophysiological patterns and acoustic oscillations in spoken language. We conclude that speech-specific neural networks show strong stability over adulthood, despite initial processes of cortical degeneration indicated by enhanced gamma power. The results of our study therefore confirm the concept that sensory and cognitive processes undergo multidirectional trajectories within the context of healthy aging.

  1. Age-Related Neural Oscillation Patterns During the Processing of Temporally Manipulated Speech.

    PubMed

    Rufener, Katharina S; Oechslin, Mathias S; Wöstmann, Malte; Dellwo, Volker; Meyer, Martin

    2016-05-01

    This EEG-study aims to investigate age-related differences in the neural oscillation patterns during the processing of temporally modulated speech. Viewing from a lifespan perspective, we recorded the electroencephalogram (EEG) data of three age samples: young adults, middle-aged adults and older adults. Stimuli consisted of temporally degraded sentences in Swedish-a language unfamiliar to all participants. We found age-related differences in phonetic pattern matching when participants were presented with envelope-degraded sentences, whereas no such age-effect was observed in the processing of fine-structure-degraded sentences. Irrespective of age, during speech processing the EEG data revealed a relationship between envelope information and the theta band (4-8 Hz) activity. Additionally, an association between fine-structure information and the gamma band (30-48 Hz) activity was found. No interaction, however, was found between acoustic manipulation of stimuli and age. Importantly, our main finding was paralleled by an overall enhanced power in older adults in high frequencies (gamma: 30-48 Hz). This occurred irrespective of condition. For the most part, this result is in line with the Asymmetric Sampling in Time framework (Poeppel in Speech Commun 41:245-255, 2003), which assumes an isomorphic correspondence between frequency modulations in neurophysiological patterns and acoustic oscillations in spoken language. We conclude that speech-specific neural networks show strong stability over adulthood, despite initial processes of cortical degeneration indicated by enhanced gamma power. The results of our study therefore confirm the concept that sensory and cognitive processes undergo multidirectional trajectories within the context of healthy aging. PMID:26613726

  2. [Attenuated Total Reflection Infrared Spectroscopy for Degradation Profile of High Density Polyethylene after Weathering Aging].

    PubMed

    Guo, Jun-jun; Yan, Hua; Bao, He-bin; Wang, Xue-mei; Hu, Zhi-de; Yang, Jian-jian

    2015-06-01

    High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (ATR-FTIR). The structural changes were studied qualitatively, mainly from the polymeric chain breaking, branching and oxidation to distinguish the degradation profile. The variations of crystallinity & carbonyl index were also studied quantitatively according to the characteristic peaks intensity & area ratio. Finally, the relationships between structural changes and mechanical properties were investigated. The results showed that the polymeric chain breaking & branching play a leading role before 3 months in the aging progress. Then oxidation phenomena gradually takes place during 3-6 months. The chain branching & oxidation were predominant factors after 6 months. Nine months later, the oxidation was saturated gradually. Furthermore, the aging process is positively correlated to the temperature and irradiation. After 12 months aging, the carbonyl index increased by 112 times and crystallinity was 10% higher than before. The tensile/bending modulus deceased faster than tensile/bending strength of HDPE. The linear degree of tensile modulus and carbonyl index was 0.97. The degree of linearity of tensile strength and crystallinity calculated by feature bands (720-730 cm(-1)) was 0.96. It showed that the mechanical properties of HDPE can be speculated from the structural changes by ATR-FTIR. PMID:26601359

  3. Effectiveness of storage practices in mitigating aging degradation during reactor layup

    SciTech Connect

    Enderlin, W.I.

    1995-09-01

    One of the issues identified in the US Nuclear Regulatory Commission`s Nuclear Plant Aging Research program plan is the need to understand the state of ``mothballed`` or other out-of-service equipment to ensure subsequent safe operation. Programs for proper storage and preservation of materials and components are required by NRC regulations (10 CFR 50, Appendix B). However, materials and components have been seriously degraded due to improper storage, protection, or layup, at facilities under construction as well as those with operating licenses. Pacific Northwest Laboratory has evaluated management of aging for unstarted or mothballed nuclear power plants. The investigations revealed that no uniform guidance in the industry addresses reactor layup. In each case investigated, layup was not initiated in a timely manner, primarily because of schedule uncertainty. Hence, it is reasonable to assume that this delay resulted in accelerated aging of some safety-significant structures, systems, and components (SSCs). The applicable layup process is site-specific. The reactor type, climatic setting, operational status, and materials of construction are factors that strongly dictate the layup method to be used. The adequacy of current layup practices, and hence their impact on safety-significant SSCS, is not fully understood.

  4. [Attenuated Total Reflection Infrared Spectroscopy for Degradation Profile of High Density Polyethylene after Weathering Aging].

    PubMed

    Guo, Jun-jun; Yan, Hua; Bao, He-bin; Wang, Xue-mei; Hu, Zhi-de; Yang, Jian-jian

    2015-06-01

    High density polyethylene (HDPE) was widely used as rotational packaging case in the material reserve field. The chemical changes of HDPE, exposed to particular climatic conditions of tropic marine atmosphere for one year-long in Wanning Hainan, were elucidated by the attenuated total reflection infrared spectroscopy (ATR-FTIR). The structural changes were studied qualitatively, mainly from the polymeric chain breaking, branching and oxidation to distinguish the degradation profile. The variations of crystallinity & carbonyl index were also studied quantitatively according to the characteristic peaks intensity & area ratio. Finally, the relationships between structural changes and mechanical properties were investigated. The results showed that the polymeric chain breaking & branching play a leading role before 3 months in the aging progress. Then oxidation phenomena gradually takes place during 3-6 months. The chain branching & oxidation were predominant factors after 6 months. Nine months later, the oxidation was saturated gradually. Furthermore, the aging process is positively correlated to the temperature and irradiation. After 12 months aging, the carbonyl index increased by 112 times and crystallinity was 10% higher than before. The tensile/bending modulus deceased faster than tensile/bending strength of HDPE. The linear degree of tensile modulus and carbonyl index was 0.97. The degree of linearity of tensile strength and crystallinity calculated by feature bands (720-730 cm(-1)) was 0.96. It showed that the mechanical properties of HDPE can be speculated from the structural changes by ATR-FTIR.

  5. Degradation diagnosis of aged Li4Ti5O12/LiFePO4 batteries

    NASA Astrophysics Data System (ADS)

    Castaing, Rémi; Reynier, Yvan; Dupré, Nicolas; Schleich, Donald; Jouanneau Si Larbi, Séverine; Guyomard, Dominique; Moreau, Philippe

    2014-12-01

    Li4Ti5O12/LiFePO4 cells are cycled under 4 different conditions of discharge profile (galvanostatic or driving-based) and cycling rates (C/8 or 1C) during 4-5 months. All the cells exhibit capacity fade whose extent is not correlated with the aging condition. In order to understand aging phenomena, cells are disassembled at the end of cycle life and the recovered electrodes are analyzed using electrochemistry, electron microscopy, XRD and MAS-NMR. Positive and negative electrodes show no loss in active material and no change in electrochemical activity, active material structure and composite electrode structure. This rules out any irreversible electrode degradation. Lithium stoichiometry estimated by both XRD and electrochemistry is unexpectedly low in the positive electrode when the aging is stopped at full discharge. That indicates a loss of cyclable lithium or electrons leading to cell balancing evolution. That loss may have been caused by parasitic reactions occurring at both electrodes, in accordance with their rich surface chemistry as evidenced by MAS-NMR.

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

    PubMed Central

    Jeronimus, Bertus F.; Stavrakakis, Nikolaos; Veenstra, René; Oldehinkel, Albertine J.

    2015-01-01

    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. PMID:26076384

  7. Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

    NASA Astrophysics Data System (ADS)

    Lai, T.; Biggie, R.; Brooks, A.; Potter, B. G.; Simmons-Potter, K.

    2015-09-01

    Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following

  8. Age-dependent degradation of the protein adsorption capacity of titanium.

    PubMed

    Hori, N; Att, W; Ueno, T; Sato, N; Yamada, M; Saruwatari, L; Suzuki, T; Ogawa, T

    2009-07-01

    Reported bone-implant contact percentages are far below the ideal 100%. We tested a hypothesis that the protein adsorption capability of titanium, which is critical to the process of osseointegration, changes over time before its use. Machined, acid-etched, and sandblasted surfaces were prepared and stored under dark ambient conditions for 3 days, 1 week, or 4 weeks. For all surfaces, protein adsorption decreased as the storage time increased, and their decreasing rates were dependent on titanium topography. After 4 weeks, the amounts of albumin and fibronectin adsorbed by the acid-etched surface were only 20% and 35%, respectively, of that adsorbed by the fresh surface after 2 hours of incubation, and remained substantially low even after 24 hours. This time-dependent degradation in protein adsorption of titanium correlated with its naturally decreasing hydrophilicity, which was not observed for the nickel and chromium surfaces, indicating a titanium-specific biological aging.

  9. Parainflammation, chronic inflammation, and age-related macular degeneration.

    PubMed

    Chen, Mei; Xu, Heping

    2015-11-01

    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 as a result of its unique anatomic and physiologic 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, undergoes low levels of activation (parainflammation). In many cases, this parainflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration, this parainflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal parainflammation include genetic predisposition, environmental risk factors, and old age. Dysregulated parainflammation (chronic inflammation) in age-related macular degeneration damages the blood retina barrier, 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 age-related macular degeneration and explores the difference between beneficial parainflammation and the detrimental chronic inflammation in the context of age-related macular degeneration.

  10. Relative Weights of the Backpacks of Elementary-Aged Children

    ERIC Educational Resources Information Center

    Bryant, Benjamin P.; Bryant, Judith B.

    2014-01-01

    The purpose of the study was to describe the range of relative backpack weights of one group of elementary-aged children and the extent to which they exceeded recommended levels. A second purpose was to explore whether gender and age help predict the relative weight of children's backpacks. Ninety-five 8- to 12-year-old elementary school…

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

    PubMed

    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. PMID:26572116

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

    PubMed

    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.

  13. A Context for Teaching Aging-Related Public Policy.

    ERIC Educational Resources Information Center

    Brown, David K.

    1999-01-01

    Describes two points of view regarding age-related public programs (Medicaid, Medicare, Social Security): that of devolutionists who would curtail them and safety netters who maintain the government's role is indispensable. Uses Relative Deprivation theory as a framework for teaching public policy about aging. (SK)

  14. Unique Relations of Age and Delinquency with Cognitive Control

    ERIC Educational Resources Information Center

    Iselin, Anne-Marie R.; DeCoster, Jamie

    2012-01-01

    Context processing has significant empirical support as an explanation of age- and psychopathology-related deficiencies in cognitive control. We examined whether context processing generalizes to younger individuals who are in trouble with the law. We tested whether age and delinquency might have unique relations to context processing skills in…

  15. How Pervasive Are Relative Age Effects in Secondary School Education?

    ERIC Educational Resources Information Center

    Cobley, Stephen; McKenna, Jim; Baker, Joeseph; Wattie, Nick

    2009-01-01

    Relative age effects (RAEs; R. H. Barnsley, A. H. Thompson, & P. E. Barnsley, 1985) convey school attainment (dis)advantages depending on whether one is relatively older or younger within annually age-grouped cohorts. In the present study, the authors examined the pervasiveness of RAEs by examining (a) attainment in 4 secondary school subjects,…

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

    PubMed

    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.

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

    PubMed Central

    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. PMID:25232097

  18. Glycation-altered proteolysis as a pathobiologic mechanism that links dietary glycemic index, aging, and age-related disease (in nondiabetics).

    PubMed

    Uchiki, Tomoaki; Weikel, Karen A; Jiao, Wangwang; Shang, Fu; Caceres, Andrea; Pawlak, Dorota; Handa, James T; Brownlee, Michael; Nagaraj, Ram; Taylor, Allen

    2012-02-01

    Epidemiologic studies indicate that the risks for major age-related debilities including coronary heart disease, diabetes, and age-related macular degeneration (AMD) are diminished in people who consume lower glycemic index (GI) diets, but lack of a unifying physiobiochemical mechanism that explains the salutary effect is a barrier to implementing dietary practices that capture the benefits of consuming lower GI diets. We established a simple murine model of age-related retinal lesions that precede AMD (hereafter called AMD-like lesions). We found that consuming a higher GI diet promotes these AMD-like lesions. However, mice that consumed the lower vs. higher GI diet had significantly reduced frequency (P < 0.02) and severity (P < 0.05) of hallmark age-related retinal lesions such as basal deposits. Consuming higher GI diets was associated with > 3 fold higher accumulation of advanced glycation end products (AGEs) in retina, lens, liver, and brain in the age-matched mice, suggesting that higher GI diets induce systemic glycative stress that is etiologic for lesions. Data from live cell and cell-free systems show that the ubiquitin-proteasome system (UPS) and lysosome/autophagy pathway [lysosomal proteolytic system (LPS)] are involved in the degradation of AGEs. Glycatively modified substrates were degraded significantly slower than unmodified substrates by the UPS. Compounding the detriments of glycative stress, AGE modification of ubiquitin and ubiquitin-conjugating enzymes impaired UPS activities. Furthermore, ubiquitin conjugates and AGEs accumulate and are found in lysosomes when cells are glycatively stressed or the UPS or LPS/autophagy are inhibited, indicating that the UPS and LPS interact with one another to degrade AGEs. Together, these data explain why AGEs accumulate as glycative stress increases. PMID:21967227

  19. Prediction of troponin-T degradation using color image texture features in 10d aged beef longissimus steaks.

    PubMed

    Sun, X; Chen, K J; Berg, E P; Newman, D J; Schwartz, C A; Keller, W L; Maddock Carlin, K R

    2014-02-01

    The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n = 102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat. PMID:24200578

  20. Undergraduate Students' Perceptions and Behaviors Related to the Aged and to Aging Processes

    ERIC Educational Resources Information Center

    Van Dussen, Daniel J.; Weaver, Robert R.

    2009-01-01

    Aging education is relatively new to the university, and our understanding of the perspectives students bring to aging populations is correspondingly limited. This investigation surveys 546 students at a midsized, Midwestern university to explore students' views toward elders, toward serving elders, and toward the relevance of aging education for…

  1. Meta-analysis of age-related gene expression profiles identifies common signatures of aging

    PubMed Central

    de Magalhães, João Pedro; Curado, João; Church, George M.

    2009-01-01

    Motivation: Numerous microarray studies of aging have been conducted, yet given the noisy nature of gene expression changes with age, elucidating the transcriptional features of aging and how these relate to physiological, biochemical and pathological changes remains a critical problem. Results: We performed a meta-analysis of age-related gene expression profiles using 27 datasets from mice, rats and humans. Our results reveal several common signatures of aging, including 56 genes consistently overexpressed with age, the most significant of which was APOD, and 17 genes underexpressed with age. We characterized the biological processes associated with these signatures and found that age-related gene expression changes most notably involve an overexpression of inflammation and immune response genes and of genes associated with the lysosome. An underexpression of collagen genes and of genes associated with energy metabolism, particularly mitochondrial genes, as well as alterations in the expression of genes related to apoptosis, cell cycle and cellular senescence biomarkers, were also observed. By employing a new method that emphasizes sensitivity, our work further reveals previously unknown transcriptional changes with age in many genes, processes and functions. We suggest these molecular signatures reflect a combination of degenerative processes but also transcriptional responses to the process of aging. Overall, our results help to understand how transcriptional changes relate to the process of aging and could serve as targets for future studies. Availability: http://genomics.senescence.info/uarrays/signatures.html Contact: jp@senescence.info Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19189975

  2. Age-related responses to mild restraint in the rat.

    PubMed

    Rattner, B A; Michael, S D; Altland, P D

    1983-11-01

    Immature, postpubertal, young adult, and middle-aged rats were lightly restrained for 4 h. Relative to untreated controls, restraint uniformly reduced body weight and plasma luteinizing hormone concentration and elevated plasma corticosterone concentration in all age groups. However, restraint increased activities of plasma alanine and aspartate aminotransferase, creatine phosphokinase, and fructose-diphosphate aldolase in only immature and middle-aged animals. This age-related release of tissue enzymes is hypothesized to reflect enhanced responsiveness to catecholamines in immature rats, and possible ischemia related to diminished vasodilatory activity in middle-aged rats. On the basis of these changes, tolerance to restraint in postpubertal and young adults appears to be slightly greater than that of immature and middle-aged rats.

  3. Age-related cochlear hair cell loss in the chinchilla.

    PubMed

    Bhattacharyya, T K; Dayal, V S

    1985-01-01

    The spiral organ of the chinchilla was studied by the surface-preparation technique in four different age groups: 1 month, 6 months, 1 year, and 4 years, to assess age-related hair cell loss. Decrease in hair cell population is linearly related to age, and damage rate of outer hair cells is greater than that of inner hair cells. The mean percentage of damaged total outer hair cells was 0.60%, 1.16%, 1.71%, and 7.07% in animals in 1 month, 6 months, 1 year, and 4 years of age, respectively. Outer hair cell loss was greatest in the apex of the cochlea and, of these cells, the outermost row was the most affected. Damage to inner hair cells also increases with age. Age-related apical cochlear cell loss in the chinchilla is comparable to that observed in other laboratory animals. PMID:3970507

  4. Thermal degradation of new and aged urethane foam and epon 826 epoxy.

    SciTech Connect

    Kruizenga, Alan Michael; Mills, Bernice E.

    2013-08-01

    Thermal desorption spectroscopy was used to monitor the decomposition as a function of temperature for the foam and epoxy as a function of temperature in the range of 60C to 170C. Samples were studied with one day holds at each of the studied temperatures. Both new (FoamN and EpoxyN) and aged (FoamP and EpoxyP) samples were studied. During these ~10 day experiments, the foam samples lost 11 to 13% of their weight and the EpoxyN lost 10% of its weight. The amount of weight lost was difficult to quantify for EpoxyP because of its inert filler. The onset of the appearance of organic degradation products from FoamP began at 110C. Similar products did not appear until 120C for FoamN, suggesting some effect of the previous decades of storage for FoamP. In the case of the epoxies, the corresponding temperatures were 120C for EpoxyP and 110C for EpoxyN. Suggestions for why the aged epoxy seems more stable than newer sample include the possibility of incomplete curing or differences in composition. Recommendation to limit use temperature to 90-100C for both epoxy and foam.

  5. Glutamatergic treatment strategies for age-related memory disorders.

    PubMed

    Müller, W E; Scheuer, K; Stoll, S

    1994-01-01

    Age-related changes of N-methyl-D-aspartate (NMDA) receptors have been found in cortical areas and in the hippocampus of many species. On the basis of a variety of experimental observations it has been suggested that the decrease of NMDA receptor density might be one of the causative factors of the cognitive decline with aging. Based on these findings several strategies have been developed to improve cognition by compensating the NMDA receptor deficits in aging. The most promising approaches are the indirect activation of glutamatergic neurotransmission by agonists of the glycine site or the restoration of the age-related deficit of receptor density by several nootropics. PMID:7997073

  6. Evaluation of the effect of organic pro-degradant concentration in polypropylene exposed to the natural ageing

    NASA Astrophysics Data System (ADS)

    Montagna, L. S.; Catto, A. L.; Rossini, K.; Forte, M. M. C.; Santana, R. M. C.

    2014-05-01

    The production and consumption of plastics in the last decade has recorded a remarkable increase in the scientific and industrial interest in environmentally degradable polymer (EDPs). Polymers wastes are deposited improperly, such as dumps, landfills, rivers and seas, causing a serious problem by the accumulation in the environment. The abiotic processes, like the photodegradation, are the most efficient occurring in the open environmental, where the polymers undergo degradation from the action of sunlight that result from direct exposure to solar radiation, however depend of the type of chemical ageing, which is the principal component of climatic ageing. The subject of this work is to study the influence of concentration of organic pro-degradant (1, 2 and 3 % w/w) in the polypropylene (PP) exposed in natural ageing. PP samples with and without the additive were processed in plates square form, obtained by thermal compression molding (TCM) using a press at 200°C under 2 tons for 5 min, and then were exposed at natural ageing during 120 days. The presence of organic additive influenced on PP degradability, this fact was assessed by changes in the thermal and morphology properties of the samples after 120 days of natural ageing. Scanning Electronic Microscopy (SEM) results of the morphological surface of the modified PP samples showed greater degradation photochemical oxidative when compared to neat PP, due to increase of rugosity and formation of microvoids. PP samples with different pro-degradant concentration under natural ageing presented a degree of crystallinity, obtained by Differential Scanning Calorimeter (DSC) increases in comparing the neat PP.

  7. Evaluation of the effect of organic pro-degradant concentration in polypropylene exposed to the natural ageing

    SciTech Connect

    Montagna, L. S. E-mail: andrecatto@terra.com.br E-mail: mmcforte@hotmail.com Catto, A. L. E-mail: andrecatto@terra.com.br E-mail: mmcforte@hotmail.com Rossini, K. E-mail: andrecatto@terra.com.br E-mail: mmcforte@hotmail.com Forte, M. M. C. E-mail: andrecatto@terra.com.br E-mail: mmcforte@hotmail.com Santana, R. M. C. E-mail: andrecatto@terra.com.br E-mail: mmcforte@hotmail.com

    2014-05-15

    The production and consumption of plastics in the last decade has recorded a remarkable increase in the scientific and industrial interest in environmentally degradable polymer (EDPs). Polymers wastes are deposited improperly, such as dumps, landfills, rivers and seas, causing a serious problem by the accumulation in the environment. The abiotic processes, like the photodegradation, are the most efficient occurring in the open environmental, where the polymers undergo degradation from the action of sunlight that result from direct exposure to solar radiation, however depend of the type of chemical ageing, which is the principal component of climatic ageing. The subject of this work is to study the influence of concentration of organic pro-degradant (1, 2 and 3 % w/w) in the polypropylene (PP) exposed in natural ageing. PP samples with and without the additive were processed in plates square form, obtained by thermal compression molding (TCM) using a press at 200°C under 2 tons for 5 min, and then were exposed at natural ageing during 120 days. The presence of organic additive influenced on PP degradability, this fact was assessed by changes in the thermal and morphology properties of the samples after 120 days of natural ageing. Scanning Electronic Microscopy (SEM) results of the morphological surface of the modified PP samples showed greater degradation photochemical oxidative when compared to neat PP, due to increase of rugosity and formation of microvoids. PP samples with different pro-degradant concentration under natural ageing presented a degree of crystallinity, obtained by Differential Scanning Calorimeter (DSC) increases in comparing the neat PP.

  8. Network strategies to understand the aging process and help age-related drug design

    PubMed Central

    2009-01-01

    Recent studies have demonstrated that network approaches are highly appropriate tools for understanding the extreme complexity of the aging process. Moreover, the generality of the network concept helps to define and study the aging of technological and social networks and ecosystems, which may generate novel concepts for curing age-related diseases. The current review focuses on the role of protein-protein interaction networks (inter-actomes) in aging. Hubs and inter-modular elements of both interactomes and signaling networks are key regulators of the aging process. Aging induces an increase in the permeability of several cellular compartments, such as the cell nucleus, introducing gross changes in the representation of network structures. The large overlap between aging genes and genes of age-related major diseases makes drugs that aid healthy aging promising candidates for the prevention and treatment of age-related diseases, such as cancer, atherosclerosis, diabetes and neurodegenerative disorders. We also discuss a number of possible research options to further explore the potential of the network concept in this important field, and show that multi-target drugs (representing 'magic-buckshots' instead of the traditional 'magic bullets') may become an especially useful class of age-related drugs in the future. PMID:19804610

  9. Network strategies to understand the aging process and help age-related drug design.

    PubMed

    Simkó, Gábor I; Gyurkó, Dávid; Veres, Dániel V; Nánási, Tibor; Csermely, Peter

    2009-01-01

    Recent studies have demonstrated that network approaches are highly appropriate tools for understanding the extreme complexity of the aging process. Moreover, the generality of the network concept helps to define and study the aging of technological and social networks and ecosystems, which may generate novel concepts for curing age-related diseases. The current review focuses on the role of protein-protein interaction networks (inter-actomes) in aging. Hubs and inter-modular elements of both interactomes and signaling networks are key regulators of the aging process. Aging induces an increase in the permeability of several cellular compartments, such as the cell nucleus, introducing gross changes in the representation of network structures. The large overlap between aging genes and genes of age-related major diseases makes drugs that aid healthy aging promising candidates for the prevention and treatment of age-related diseases, such as cancer, atherosclerosis, diabetes and neurodegenerative disorders. We also discuss a number of possible research options to further explore the potential of the network concept in this important field, and show that multi-target drugs (representing 'magic-buckshots' instead of the traditional 'magic bullets') may become an especially useful class of age-related drugs in the future.

  10. Adverse environmental conditions influence age-related innate immune responsiveness

    PubMed Central

    May, Linda; van den Biggelaar, Anita HJ; van Bodegom, David; Meij, Hans J; de Craen, Anton JM; Amankwa, Joseph; Frölich, Marijke; Kuningas, Maris; Westendorp, Rudi GJ

    2009-01-01

    Background- The innate immune system plays an important role in the recognition and induction of protective responses against infectious pathogens, whilst there is increasing evidence for a role in mediating chronic inflammatory diseases at older age. Despite indications that environmental conditions can influence the senescence process of the adaptive immune system, it is not known whether the same holds true for the innate immune system. Therefore we studied whether age-related innate immune responses are similar or differ between populations living under very diverse environmental conditions. Methods- We compared cross-sectional age-related changes in ex vivo innate cytokine responses in a population living under affluent conditions in the Netherlands (age 20–68 years old, n = 304) and a population living under adverse environmental conditions in Ghana (age 23–95 years old, n = 562). Results- We found a significant decrease in LPS-induced Interleukin (IL)-10 and Tumor Necrosis Factor (TNF) production with age in the Dutch population. In Ghana a similar age-related decline in IL-10 responses to LPS, as well as to zymosan, or LPS plus zymosan, was observed. TNF production, however, did not show an age-associated decline, but increased significantly with age in response to co-stimulation with LPS and zymosan. Conclusion- We conclude that the decline in innate cytokine responses is an intrinsic ageing phenomenon, while pathogen exposure and/or selective survival drive pro-inflammatory responses under adverse living conditions. PMID:19480711

  11. Age-Related Changes in 1/f Neural Electrophysiological Noise

    PubMed Central

    Kramer, Mark A.; Case, John; Lepage, Kyle Q.; Tempesta, Zechari R.; Knight, Robert T.; Gazzaley, Adam

    2015-01-01

    Aging is associated with performance decrements across multiple cognitive domains. The neural noise hypothesis, a dominant view of the basis of this decline, posits that aging is accompanied by an increase in spontaneous, noisy baseline neural activity. Here we analyze data from two different groups of human subjects: intracranial electrocorticography from 15 participants over a 38 year age range (15–53 years) and scalp EEG data from healthy younger (20–30 years) and older (60–70 years) adults to test the neural noise hypothesis from a 1/f noise perspective. Many natural phenomena, including electrophysiology, are characterized by 1/f noise. The defining characteristic of 1/f is that the power of the signal frequency content decreases rapidly as a function of the frequency (f) itself. The slope of this decay, the noise exponent (χ), is often <−1 for electrophysiological data and has been shown to approach white noise (defined as χ = 0) with increasing task difficulty. We observed, in both electrophysiological datasets, that aging is associated with a flatter (more noisy) 1/f power spectral density, even at rest, and that visual cortical 1/f noise statistically mediates age-related impairments in visual working memory. These results provide electrophysiological support for the neural noise hypothesis of aging. SIGNIFICANCE STATEMENT Understanding the neurobiological origins of age-related cognitive decline is of critical scientific, medical, and public health importance, especially considering the rapid aging of the world's population. We find, in two separate human studies, that 1/f electrophysiological noise increases with aging. In addition, we observe that this age-related 1/f noise statistically mediates age-related working memory decline. These results significantly add to this understanding and contextualize a long-standing problem in cognition by encapsulating age-related cognitive decline within a neurocomputational model of 1/f noise

  12. Age-Related Changes in 1/f Neural Electrophysiological Noise.

    PubMed

    Voytek, Bradley; Kramer, Mark A; Case, John; Lepage, Kyle Q; Tempesta, Zechari R; Knight, Robert T; Gazzaley, Adam

    2015-09-23

    Aging is associated with performance decrements across multiple cognitive domains. The neural noise hypothesis, a dominant view of the basis of this decline, posits that aging is accompanied by an increase in spontaneous, noisy baseline neural activity. Here we analyze data from two different groups of human subjects: intracranial electrocorticography from 15 participants over a 38 year age range (15-53 years) and scalp EEG data from healthy younger (20-30 years) and older (60-70 years) adults to test the neural noise hypothesis from a 1/f noise perspective. Many natural phenomena, including electrophysiology, are characterized by 1/f noise. The defining characteristic of 1/f is that the power of the signal frequency content decreases rapidly as a function of the frequency (f) itself. The slope of this decay, the noise exponent (χ), is often <-1 for electrophysiological data and has been shown to approach white noise (defined as χ = 0) with increasing task difficulty. We observed, in both electrophysiological datasets, that aging is associated with a flatter (more noisy) 1/f power spectral density, even at rest, and that visual cortical 1/f noise statistically mediates age-related impairments in visual working memory. These results provide electrophysiological support for the neural noise hypothesis of aging. Significance statement: Understanding the neurobiological origins of age-related cognitive decline is of critical scientific, medical, and public health importance, especially considering the rapid aging of the world's population. We find, in two separate human studies, that 1/f electrophysiological noise increases with aging. In addition, we observe that this age-related 1/f noise statistically mediates age-related working memory decline. These results significantly add to this understanding and contextualize a long-standing problem in cognition by encapsulating age-related cognitive decline within a neurocomputational model of 1/f noise-induced deficits in

  13. Mouse models of age-related mitochondrial neurosensory hearing loss.

    PubMed

    Han, Chul; Someya, Shinichi

    2013-07-01

    Hearing loss is the most common sensory disorder in the elderly population. Overall, 10% of the population has a hearing loss in the US, and this age-related hearing disorder is projected to afflict more than 28 million Americans by 2030. Age-related hearing loss is associated with loss of sensory hair cells (sensory hearing loss) and/or spiral ganglion neurons (neuronal hearing loss) in the cochlea of the inner ear. Many lines of evidence indicate that oxidative stress and associated mitochondrial dysfunction play a central role in age-related neurodegenerative diseases and are a cause of age-related neurosensory hearing loss. Yet, the molecular mechanisms of how oxidative stress and/or mitochondrial dysfunction lead to hearing loss during aging remain unclear, and currently there is no treatment for this age-dependent disorder. Several mouse models of aging and age-related diseases have been linked to age-related mitochondrial neurosensory hearing loss. Evaluation of these animal models has offered basic knowledge of the mechanism underlying hearing loss associated with oxidative stress, mitochondrial dysfunction, and aging. Here we review the evidence that specific mutations in the mitochondrial DNA or nuclear DNA that affect mitochondrial function result in increased oxidative damage and associated loss of sensory hair cells and/or spiral ganglion neurons in the cochlea during aging, thereby causing hearing loss in these mouse models. Future studies comparing these models will provide further insight into fundamental knowledge about the disordered process of hearing and treatments to improve the lives of individuals with communication disorders. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.

  14. Syntactic processing with aging: an event-related potential study.

    PubMed

    Kemmer, Laura; Coulson, Seana; De Ochoa, Esmeralda; Kutas, Marta

    2004-05-01

    To assess age-related changes in simple syntactic processing with normal aging, event-related brain potentials (ERPs) elicited by grammatical number violations as individuals read sentences for comprehension were analyzed. Violations were found to elicit a P600 of equal amplitude and latency regardless of an individual's age. Instead, advancing age was associated with a change in the scalp distribution of the P600 effect, being less asymmetric and more frontal (though still with a parietal maximum) in older than younger adults. Our results thus show that the brain's response to simple syntactic violations, unlike those reported for simple binary categorizations and simple semantic violations, is neither slowed nor diminished in amplitude by age. At the same time, the brain's processing of these grammatical number violations did engage at least somewhat different brain regions as a function of age, suggesting a qualitative change rather than any simple quantitative change in speed of processing.

  15. Age-related gene expression change of GABAergic system in visual cortex of rhesus macaque.

    PubMed

    Liao, Chenghong; Han, Qian; Ma, Yuanye; Su, Bing

    2016-09-30

    Degradation of visual function is a common phenomenon during aging and likely mediated by change in the impaired central visual pathway. Treatment with GABA or its agonist could recover the ability of visual neurons in the primary visual cortex of senescent macaques. However, little is known about how GABAergic system change is related to the aged degradation of visual function in nonhuman primate. With the use of quantitative PCR method, we measured the expression change of 24 GABA related genes in the primary visual cortex (Brodmann's 17) of different age groups. In this study, both of mRNA and protein of glutamic acid decarboxylase (GAD65) were measured by real-time RT-PCR and Western blot, respectively. Results revealed that the level of GAD65 message was not significantly altered, but the proteins were significantly decreased in the aged monkey. As GAD65 plays an important role in GABA synthesis, the down-regulation of GAD65 protein was likely the key factor leading to the observed GABA reduction in the primary visual cortex of the aged macaques. In addition, 7 of 14 GABA receptor genes were up-regulated and one GABA receptor gene was significantly reduced during aging process even after Banjamini correction for multiple comparisons (P<0.05). These results suggested that the dysregulation of GAD65 protein might contribute to some age-related neural visual dysfunctions and most of GABA receptor genes induce a clear indication of compensatory effect for the reduced GABA release in the healthy aged monkey cortex. PMID:27196061

  16. Epigenome-Wide Scans Identify Differentially Methylated Regions for Age and Age-Related Phenotypes in a Healthy Ageing Population

    PubMed Central

    Yang, Tsun-Po; Pidsley, Ruth; Nisbet, James; Glass, Daniel; Mangino, Massimo; Zhai, Guangju; Zhang, Feng; Valdes, Ana; Shin, So-Youn; Dempster, Emma L.; Murray, Robin M.; Grundberg, Elin; Hedman, Asa K.; Nica, Alexandra; Small, Kerrin S.; Dermitzakis, Emmanouil T.; McCarthy, Mark I.; Mill, Jonathan; Spector, Tim D.; Deloukas, Panos

    2012-01-01

    Age-related changes in DNA methylation have been implicated in cellular senescence and longevity, yet the causes and functional consequences of these variants remain unclear. To elucidate the role of age-related epigenetic changes in healthy ageing and potential longevity, we tested for association between whole-blood DNA methylation patterns in 172 female twins aged 32 to 80 with age and age-related phenotypes. Twin-based DNA methylation levels at 26,690 CpG-sites showed evidence for mean genome-wide heritability of 18%, which was supported by the identification of 1,537 CpG-sites with methylation QTLs in cis at FDR 5%. We performed genome-wide analyses to discover differentially methylated regions (DMRs) for sixteen age-related phenotypes (ap-DMRs) and chronological age (a-DMRs). Epigenome-wide association scans (EWAS) identified age-related phenotype DMRs (ap-DMRs) associated with LDL (STAT5A), lung function (WT1), and maternal longevity (ARL4A, TBX20). In contrast, EWAS for chronological age identified hundreds of predominantly hyper-methylated age DMRs (490 a-DMRs at FDR 5%), of which only one (TBX20) was also associated with an age-related phenotype. Therefore, the majority of age-related changes in DNA methylation are not associated with phenotypic measures of healthy ageing in later life. We replicated a large proportion of a-DMRs in a sample of 44 younger adult MZ twins aged 20 to 61, suggesting that a-DMRs may initiate at an earlier age. We next explored potential genetic and environmental mechanisms underlying a-DMRs and ap-DMRs. Genome-wide overlap across cis-meQTLs, genotype-phenotype associations, and EWAS ap-DMRs identified CpG-sites that had cis-meQTLs with evidence for genotype–phenotype association, where the CpG-site was also an ap-DMR for the same phenotype. Monozygotic twin methylation difference analyses identified one potential environmentally-mediated ap-DMR associated with total cholesterol and LDL (CSMD1). Our results suggest that in a

  17. Age-related differences in multiple task monitoring.

    PubMed

    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.

  18. Stem cell transplantation improves aging-related diseases

    PubMed Central

    Ikehara, Susumu; Li, Ming

    2014-01-01

    Aging is a complex process of damage accumulation, and has been viewed as experimentally and medically intractable. The number of patients with age-associated diseases such as type 2 diabetes mellitus (T2DM), osteoporosis, Alzheimer's disease (AD), Parkinson's disease, atherosclerosis, and cancer has increased recently. Aging-related diseases are related to a deficiency of the immune system, which results from an aged thymus and bone marrow cells. Intra bone marrow-bone marrow transplantation (IBM-BMT) is a useful method to treat intractable diseases. This review summarizes findings that IBM-BMT can improve and treat aging-related diseases, including T2DM, osteoporosis and AD, in animal models. PMID:25364723

  19. Age-Related Differences in Multiple Task Monitoring

    PubMed Central

    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. PMID:25215609

  20. Nutritional influences on epigenetics and age-related disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Age-Related Differences in Moral Identity across Adulthood

    ERIC Educational Resources Information Center

    Krettenauer, Tobias; Murua, Lourdes Andrea; Jia, Fanli

    2016-01-01

    In this study, age-related differences in adults' moral identity were investigated. Moral identity was conceptualized a context-dependent self-structure that becomes differentiated and (re)integrated in the course of development and that involves a broad range of value-orientations. Based on a cross-sectional sample of 252 participants aged 14 to…

  2. The Role of Social Activity in Age-Cognition Relations

    ERIC Educational Resources Information Center

    Soubelet, Andrea

    2013-01-01

    The goal of the current project was to examine whether engaging in social activity may moderate or mediate the relation between age and cognitive functioning. A large age range sample of adults performed a variety of cognitive tests and completed a social activities questionnaire. Results did not support the moderator hypothesis, as age…

  3. Nutritional modulation of age-related macular degeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Age-related Oxidative Stress Compromises Endosomal Proteostasis

    PubMed Central

    Cannizzo, Elvira S.; Clement, Cristina C.; Morozova, Kateryna; Valdor, Rut; Kaushik, Susmita; Almeida, Larissa N.; Follo, Carlo; Sahu, Ranjit; Cuervo, Ana Maria; Macian, Fernando; Santambrogio, Laura

    2012-01-01

    A hallmark of aging is an imbalance between production and clearance of reactive oxygen species and increased levels of oxidatively damaged biomolecules. Herein we demonstrate that splenic and nodal antigen presenting cells purified from old mice accumulate oxidatively modified proteins with side chain carbonylation, advanced glycation end products and lipid peroxidation. We show further that the endosomal accumulation of oxidatively modified proteins interferes with the efficient processing of exogenous antigens and degradation of macroautophagy-delivered proteins. In support of a causative role for oxidized products in the inefficient immune response, a decrease in oxidative stress improved the adaptive immune response to immunizing antigens. These findings underscore a previously unrecognized negative effect of age-dependent changes in cellular proteostasis on the immune response. PMID:22840404

  5. BOLD Variability is Related to Dopaminergic Neurotransmission and Cognitive Aging.

    PubMed

    Guitart-Masip, Marc; Salami, Alireza; Garrett, Douglas; Rieckmann, Anna; Lindenberger, Ulman; Bäckman, Lars

    2016-05-01

    Dopamine (DA) losses are associated with various aging-related cognitive deficits. Typically, higher moment-to-moment brain signal variability in large-scale patterns of voxels in neocortical regions is linked to better cognitive performance and younger adult age, yet the physiological mechanisms regulating brain signal variability are unknown. We explored the relationship among adult age, DA availability, and blood oxygen level-dependent (BOLD) signal variability, while younger and older participants performed a spatial working memory (SWM) task. We quantified striatal and extrastriatal DA D1 receptor density with [(11)C]SCH23390 and positron emission tomography in all participants. We found that BOLD variability in a neocortical region was negatively related to age and positively related to SWM performance. In contrast, BOLD variability in subcortical regions and bilateral hippocampus was positively related to age and slower responses, and negatively related to D1 density in caudate and dorsolateral prefrontal cortex. Furthermore, BOLD variability in neocortical regions was positively associated with task-related disengagement of the default-mode network, a network whose activation needs to be suppressed for efficient SWM processing. Our results show that age-related DA losses contribute to changes in brain signal variability in subcortical regions and suggest a potential mechanism, by which neocortical BOLD variability supports cognitive performance.

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

    PubMed

    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.

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

    PubMed Central

    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

  8. Managed care implications of age-related ocular conditions.

    PubMed

    Cardarelli, William J; Smith, Roderick A

    2013-05-01

    The economic costs of age-related ocular diseases and vision loss are increasing rapidly as our society ages. In addition to the direct costs of treating age-related eye diseases, elderly persons with vision loss are at significantly increased risk for falls and fractures, experiencing social isolation, and suffering from an array of comorbid medical conditions compared with individuals with normal vision. Recent studies estimate the total economic burden (direct and indirect costs) of adult vision impairment in the United States at $51.4 billion. This figure is expected to increase as the baby boomer generation continues to age. While a number of highly effective new therapies have caused a paradigm shift in the management of several major age-related ocular diseases in recent years, these treatments come at a substantial cost. This article reviews the economic burdens and treatment-related costs of 4 major ocular diseases of aging-glaucoma, age-related macular degeneration, diabetic retinopathy, and dry eye disease-and the implications for managed care.

  9. Age-related changes in monocytes exacerbate neointimal hyperplasia after vascular injury

    PubMed Central

    Martinez, Laisel; Gomez, Camilo; Vazquez-Padron, Roberto I.

    2015-01-01

    Neointimal hyperplasia is the leading cause of restenosis after endovascular interventions. It is characterized by the accumulation of myofibroblast-like cells and extracellular matrix in the innermost layer of the wall and is exacerbated by inflammation. Monocytes from either young or aged rats were applied perivascularly to injured vascular walls of young recipient animals. Monocytes from aged rats, but not young donors, increased neointima thickness. Accordingly, the gene expression profiles of CD11b+ monocytes from aged rats showed significant up-regulation of genes involved in cellular adhesion, lipid degradation, cytotoxicity, differentiation, and inflammation. These included cadherin 13 (Cdh13), colony stimulating factor 1 (Csf1), chemokine C-X-C motif ligand 1 (Cxcl1), endothelial cell-selective adhesion molecule (Esam), and interferon gamma (Ifng). In conclusion, our results suggest that the increased inflammatory and adhesive profile of monocytes contributes to pathological wall remodeling in aged-related vascular diseases. PMID:25965835

  10. RELIABILITY MODELS OF AGING PASSIVE COMPONENTS INFORMED BY MATERIALS DEGRADATION METRICS TO SUPPORT LONG-TERM REACTOR OPERATIONS

    SciTech Connect

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2012-05-01

    Paper describes a methodology for the synthesis of nuclear power plant service data with expert-elicited materials degradation information to estimate the future failure rates of passive components. This method should be an important resource to long-term plant operations and reactor life extension. Conventional probabilistic risk assessments (PRAs) are not well suited to addressing long-term reactor operations. Since passive structures and components are among those for which replacement can be least practical, they might be expected to contribute increasingly to risk in an aging plant; yet, passives receive limited treatment in PRAs. Furthermore, PRAs produce only snapshots of risk based on the assumption of time-independent component failure rates. This assumption is unlikely to be valid in aging systems. The treatment of aging passive components in PRA presents challenges. Service data to quantify component reliability models are sparse, and this is exacerbated by the greater data demands of age-dependent reliability models. Another factor is that there can be numerous potential degradation mechanisms associated with the materials and operating environment of a given component. This deepens the data problem since risk-informed management of component aging will demand an understanding of the long-term risk significance of individual degradation mechanisms. In this paper we describe a Bayesian methodology that integrates metrics of materials degradation susceptibility with available plant service data to estimate age-dependent passive component reliabilities. Integration of these models into conventional PRA will provide a basis for materials degradation management informed by predicted long-term operational risk.

  11. Degradation of sucralose in groundwater and implications for age dating contaminated groundwater.

    PubMed

    Robertson, W D; Van Stempvoort, D R; Spoelstra, J; Brown, S J; Schiff, S L

    2016-01-01

    The artificial sweetener sucralose has been in use in Canada and the US since about 2000 and in the EU since 2003, and is now ubiquitous in sanitary wastewater in many parts of the world. It persists during sewage treatment and in surface water environments and as such, has been suggested as a powerful tracer of wastewater. In this study, longer-term persistence of sucralose was examined in groundwater by undertaking a series of three sampling snapshots of a well constrained wastewater plume in Canada (Long Point septic system) over a 6-year period from 2008 to 2014. A shrinking sucralose plume in 2014, compared to earlier sampling, during this period when sucralose use was likely increasing, provides clear evidence of degradation. However, depletion of sucralose from a mean of 40 μg/L in the proximal plume zone, occurred at a relatively slow rate over a period of several months to several years. Furthermore, examination of septic tank effluent and impacted groundwater at six other sites in Canada, revealed that sucralose was present in all samples of septic tank effluent (6-98 μg/L, n = 32) and in all groundwater samples (0.7-77 μg/L, n = 64). Even though sucralose degradation is noted in the Long Point plume, its ubiquitous presence in the groundwater plumes at all seven sites implies a relatively slow rate of decay in many groundwater septic plume environments. Thus, sucralose has the potential to be used as an indicator of 'recent' wastewater contamination. The presence of sucralose identifies groundwater that was recharged after 2000 in Canada and the US and after 2003 in the EU and many Asian countries. PMID:26575474

  12. Degradation of sucralose in groundwater and implications for age dating contaminated groundwater.

    PubMed

    Robertson, W D; Van Stempvoort, D R; Spoelstra, J; Brown, S J; Schiff, S L

    2016-01-01

    The artificial sweetener sucralose has been in use in Canada and the US since about 2000 and in the EU since 2003, and is now ubiquitous in sanitary wastewater in many parts of the world. It persists during sewage treatment and in surface water environments and as such, has been suggested as a powerful tracer of wastewater. In this study, longer-term persistence of sucralose was examined in groundwater by undertaking a series of three sampling snapshots of a well constrained wastewater plume in Canada (Long Point septic system) over a 6-year period from 2008 to 2014. A shrinking sucralose plume in 2014, compared to earlier sampling, during this period when sucralose use was likely increasing, provides clear evidence of degradation. However, depletion of sucralose from a mean of 40 μg/L in the proximal plume zone, occurred at a relatively slow rate over a period of several months to several years. Furthermore, examination of septic tank effluent and impacted groundwater at six other sites in Canada, revealed that sucralose was present in all samples of septic tank effluent (6-98 μg/L, n = 32) and in all groundwater samples (0.7-77 μg/L, n = 64). Even though sucralose degradation is noted in the Long Point plume, its ubiquitous presence in the groundwater plumes at all seven sites implies a relatively slow rate of decay in many groundwater septic plume environments. Thus, sucralose has the potential to be used as an indicator of 'recent' wastewater contamination. The presence of sucralose identifies groundwater that was recharged after 2000 in Canada and the US and after 2003 in the EU and many Asian countries.

  13. Do weight categories prevent athletes from relative age effect?

    PubMed

    Delorme, Nicolas

    2014-01-01

    The aim of this study was to investigate whether weight categories prevent young athletes from being exposed to a relative age effect. The dates of birth of all French female (n = 727) and male (n = 5440) amateur boxers who participated in the 2010-2011 season were collected from the federation database. The dates of birth of all French male professional boxers (n = 354) were also collected. The results show an absence of a relative age effect among French female and male amateur boxers. The results also show an absence of this phenomenon among French male professional boxers. The male 18-18+ age category reveal an inverse relative age effect. This inverse relative age effect might be interpreted as the result of a strategic adaptation from relatively younger children who shift from one sport to another where there are weight categories in order to ensure fair competition. The results of this study suggest that the weight category system is a possible solution within the relative age effect phenomenon.

  14. Age-related carbonyl stress and erythrocyte membrane protein carbonylation.

    PubMed

    Li, Guolin; Liu, Li; Hu, Hui; Zhao, Qiong; Xie, Fuxia; Chen, Keke; Liu, Shenglin; Chen, Yaqin; Shi, Wang; Yin, Dazhong

    2010-01-01

    Reactive carbonyl species (RCS) have been widely used as indicators of oxidative stress. However, the associations of carbonyl stress with aging process and biochemical alteration of erythrocyte are still poorly understood. Fresh blood samples in vacutainer tubes containing sodium heparinate were obtained from 874 volunteers who were divided into young, adult and old groups based on their age. Plasma RCS and thiols concentrations between different age groups and erythrocyte membrane protein carbonylation in the adult group were detected within 24h of the blood sampling. Results showed that the plasma thiols concentration decreased gradually during aging process, and the p-values between all three groups are less than 0.05. The plasma RCS concentration in different age groups showed a nonlinear association with age. The levels in the young group were slightly higher than the adult group (not significant) and lower than the old group (p < 0.01). The protein carbonylation of erythrocyte membrane was positively correlated with plasma RCS concentration (p < 0.01), but not plasma thiols concentration. We conclude that higher levels of RCS, not lower levels of thiols, in plasma are a direct risk factor for the protein carbonylation of erythrocyte membrane. Owing to the decrease of thiols levels and increase of RCS levels during aging process, a shift from RCS-related redox allostasis to carbonyl stress would contribute to age-related biological dysfunction and even aging process.

  15. The suprachiasmatic nucleus: age-related decline in biological rhythms.

    PubMed

    Nakamura, Takahiro J; Takasu, Nana N; Nakamura, Wataru

    2016-09-01

    Aging is associated with changes in sleep duration and quality, as well as increased rates of pathologic/disordered sleep. While several factors contribute to these changes, emerging research suggests that age-related changes in the mammalian central circadian clock within the suprachiasmatic nucleus (SCN) may be a key factor. Prior work from our group suggests that circadian output from the SCN declines because of aging. Furthermore, we have previously observed age-related infertility in female mice, caused by a mismatch between environmental light-dark cycles and the intrinsic, internal biological clocks. In this review, we address regulatory mechanisms underlying circadian rhythms in mammals and summarize recent literature describing the effects of aging on the circadian system.

  16. Aging assessment of reactor instrumentation and protection system components. Aging-related operating experiences

    SciTech Connect

    Gehl, A.C.; Hagen, E.W.

    1992-07-01

    A study of the aging-related operating experiences throughout a five-year period (1984--1988) of six generic instrumentation modules (indicators, sensors, controllers, transmitters, annunciators, and recorders) was performed as a part of the Nuclear Plant Aging Research Program. The effects of aging from operational and environmental stressors were characterized from results depicted in Licensee Event Reports (LERs). The data are graphically displayed as frequency of events per plant year for operating plant ages from 1 to 28 years to determine aging-related failure trend patterns. Three main conclusions were drawn from this study: (1) Instrumentation and control (I&C) modules make a modest contribution to safety-significant events: 17% of LERs issued during 1984--1988 dealt with malfunctions of the six I&C modules studied, and 28% of the LERs dealing with these I&C module malfunctions were aging related (other studies show a range 25--50%); (2) Of the six modules studied, indicators, sensors, and controllers account for the bulk (83%) of aging-related failures; and (3) Infant mortality appears to be the dominant aging-related failure mode for most I&C module categories (with the exception of annunciators and recorders, which appear to fail randomly).

  17. PPARα agonist, fenofibrate, ameliorates age-related renal injury.

    PubMed

    Kim, Eun Nim; Lim, Ji Hee; Kim, Min Young; Kim, Hyung Wook; Park, Cheol Whee; Chang, Yoon Sik; Choi, Bum Soon

    2016-08-01

    The kidney ages quickly compared with other organs. Expression of senescence markers reflects changes in the energy metabolism in the kidney. Two important issues in aging are mitochondrial dysfunction and oxidative stress. Peroxisome proliferator-activated receptor α (PPARα) is a member of the ligand-activated nuclear receptor superfamily. PPARα plays a major role as a transcription factor that regulates the expression of genes involved in various processes. In this study, 18-month-old male C57BL/6 mice were divided into two groups, the control group (n=7) and the fenofibrate-treated group (n=7) was fed the normal chow plus fenofibrate for 6months. The PPARα agonist, fenofibrate, improved renal function, proteinuria, histological change (glomerulosclerosis and tubular interstitial fibrosis), inflammation, and apoptosis in aging mice. This protective effect against age-related renal injury occurred through the activation of AMPK and SIRT1 signaling. The activation of AMPK and SIRT1 allowed for the concurrent deacetylation and phosphorylation of their target molecules and decreased the kidney's susceptibility to age-related changes. Activation of the AMPK-FOXO3a and AMPK-PGC-1α signaling pathways ameliorated oxidative stress and mitochondrial dysfunction. Our results suggest that activation of PPARα and AMPK-SIRT1 signaling may have protective effects against age-related renal injury. Pharmacological targeting of PPARα and AMPK-SIRT1 signaling molecules may prevent or attenuate age-related pathological changes in the kidney. PMID:27130813

  18. Glycation: the angiogenic paradox in aging and age-related disorders and diseases.

    PubMed

    Roca, F; Grossin, N; Chassagne, P; Puisieux, F; Boulanger, E

    2014-05-01

    Angiogenesis is generally a quiescent process which, however, may be modified by different physiological and pathological conditions. The "angiogenic paradox" has been described in diabetes because this disease impairs the angiogenic response in a manner that differs depending on the organs involved and disease evolution. Aging is also associated with pro- and antiangiogenic processes. Glycation, the post-translational modification of proteins, increases with aging and the progression of diabetes. The effect of glycation on angiogenesis depends on the type of glycated proteins and cells involved. This complex link could be responsible for the "angiogenic paradox" in aging and age-related disorders and diseases. Using diabetes as a model, the present work has attempted to review the age-related angiogenic paradox, in particular the effects of glycation on angiogenesis during aging.

  19. Age-related differences in human skin proteoglycans

    PubMed Central

    Carrino, David A; Calabro, Anthony; Darr, Aniq B; Dours-Zimmermann, Maria T; Sandy, John D; Zimmermann, Dieter R; Sorrell, J Michael; Hascall, Vincent C; Caplan, Arnold I

    2011-01-01

    Previous work has shown that versican, decorin and a catabolic fragment of decorin, termed decorunt, are the most abundant proteoglycans in human skin. Further analysis of versican indicates that four major core protein species are present in human skin at all ages examined from fetal to adult. Two of these are identified as the V0 and V1 isoforms, with the latter predominating. The other two species are catabolic fragments of V0 and V1, which have the amino acid sequence DPEAAE as their carboxyl terminus. Although the core proteins of human skin versican show no major age-related differences, the glycosaminoglycans (GAGs) of adult skin versican are smaller in size and show differences in their sulfation pattern relative to those in fetal skin versican. In contrast to human skin versican, human skin decorin shows minimal age-related differences in its sulfation pattern, although, like versican, the GAGs of adult skin decorin are smaller than those of fetal skin decorin. Analysis of the catabolic fragments of decorin from adult skin reveals the presence of other fragments in addition to decorunt, although the core proteins of these additional decorin catabolic fragments have not been identified. Thus, versican and decorin of human skin show age-related differences, versican primarily in the size and the sulfation pattern of its GAGs and decorin in the size of its GAGs. The catabolic fragments of versican are detected at all ages examined, but appear to be in lower abundance in adult skin compared with fetal skin. In contrast, the catabolic fragments of decorin are present in adult skin, but are virtually absent from fetal skin. Taken together, these data suggest that there are age-related differences in the catabolism of proteoglycans in human skin. These age-related differences in proteoglycan patterns and catabolism may play a role in the age-related changes in the physical properties and injury response of human skin. PMID:20947661

  20. Age-Related Deterioration of Rod Vision in Mice

    PubMed Central

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

    2010-01-01

    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 of 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 to 4 month-old animals. Aging also resulted in a 2-fold reduction in the total level of opsin in the retina. Behavioral tests revealed that scotopic visual acuity and contrast sensitivity were decreased by 2-fold 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. PMID:20720130

  1. eNOS-uncoupling in age-related erectile dysfunction.

    PubMed

    Johnson, J M; Bivalacqua, T J; Lagoda, G A; Burnett, A L; 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 (BH(4)) on erectile function in the aged rats. Male Fischer 344 'young' (4-month-old) and 'aged' (19-month-old) rats were treated with a BH(4) precursor sepiapterin (10 mg/kg intraperitoneally) or vehicle for 4 days. After 1-day washout, erectile function was assessed in response to electrical stimulation of the cavernous nerve. Endothelial dysfunction (eNOS uncoupling) and oxidative stress (thiobarbituric acid reactive substances, TBARS) were measured by conducting western blot in penes samples. Erectile response was significantly reduced in aged rats, whereas eNOS uncoupling and TBARS production were significantly increased in the aged rat penis compared with young rats. Sepiapterin significantly improved erectile response in aged rats and prevented increase in TBARS production, but did not affect eNOS uncoupling in the penis of aged rats. These findings suggest that aging induces eNOS uncoupling in the penis, resulting in increased oxidative stress and ED. PMID:21289638

  2. Epigenetic modification of PKMζ rescues aging-related cognitive impairment.

    PubMed

    Chen, Chen; Meng, Shi-Qiu; Xue, Yan-Xue; Han, Ying; Sun, Cheng-Yu; Deng, Jia-Hui; Chen, Na; Bao, Yan-Ping; Zhang, Fei-Long; Cao, Lin-Lin; Zhu, Wei-Guo; Shi, Jie; Song, Wei-Hong; Lu, Lin

    2016-03-01

    Cognition is impacted by aging. However, the mechanisms that underlie aging-associated cognitive impairment are unclear. Here we showed that cognitive decline in aged rats was associated with changes in DNA methylation of protein kinase Mζ (PKMζ) in the prelimbic cortex (PrL). PKMζ is a crucial molecule involved in the maintenance of long-term memory. Using different behavioral models, we confirmed that aged rats exhibited cognitive impairment in memory retention test 24 h after training, and overexpression of PKMζ in the PrL rescued cognitive impairment in aged rats. After fear conditioning, the protein levels of PKMζ and the membrane expression of GluR2 increased in the PrL in young and adult rats but not in aged rats, and the levels of methylated PKMζ DNA in the PrL decreased in all age groups, whereas the levels of unmethylated PKMζ DNA increased only in young and adult rats. We also found that environmentally enriched housing reversed the hypermethylation of PKMζ and restored cognitive performance in aged rats. Inactivation of PKMζ prevented the potentiating effects of environmental enrichment on memory retention in aged rats. These results indicated that PKMζ might be a potential target for the treatment of aging-related cognitive impairment, suggesting a potential therapeutic avenue.

  3. Epigenetic modification of PKMζ rescues aging-related cognitive impairment

    PubMed Central

    Chen, Chen; Meng, Shi-Qiu; Xue, Yan-Xue; Han, Ying; Sun, Cheng-Yu; Deng, Jia-Hui; Chen, Na; Bao, Yan-Ping; Zhang, Fei-Long; Cao, Lin-Lin; Zhu, Wei-Guo; Shi, Jie; Song, Wei-Hong; Lu, Lin

    2016-01-01

    Cognition is impacted by aging. However, the mechanisms that underlie aging-associated cognitive impairment are unclear. Here we showed that cognitive decline in aged rats was associated with changes in DNA methylation of protein kinase Mζ (PKMζ) in the prelimbic cortex (PrL). PKMζ is a crucial molecule involved in the maintenance of long-term memory. Using different behavioral models, we confirmed that aged rats exhibited cognitive impairment in memory retention test 24 h after training, and overexpression of PKMζ in the PrL rescued cognitive impairment in aged rats. After fear conditioning, the protein levels of PKMζ and the membrane expression of GluR2 increased in the PrL in young and adult rats but not in aged rats, and the levels of methylated PKMζ DNA in the PrL decreased in all age groups, whereas the levels of unmethylated PKMζ DNA increased only in young and adult rats. We also found that environmentally enriched housing reversed the hypermethylation of PKMζ and restored cognitive performance in aged rats. Inactivation of PKMζ prevented the potentiating effects of environmental enrichment on memory retention in aged rats. These results indicated that PKMζ might be a potential target for the treatment of aging-related cognitive impairment, suggesting a potential therapeutic avenue. PMID:26926225

  4. Cellular senescence in aging and age-related disease: from mechanisms to therapy

    PubMed Central

    Childs, Bennett G; Durik, Matej; Baker, Darren J; van Deursen, Jan M

    2016-01-01

    Cellular senescence, a process that imposes permanent proliferative arrest on cells in response to various stressors, has emerged as a potentially important contributor to aging and age-related disease, and it is an attractive target for therapeutic exploitation. A wealth of information about senescence in cultured cells has been acquired over the past half century; however, senescence in living organisms is poorly understood, largely because of technical limitations relating to the identification and characterization of senescent cells in tissues and organs. Furthermore, newly recognized beneficial signaling functions of senescence suggest that indiscriminately targeting senescent cells or modulating their secretome for anti-aging therapy may have negative consequences. Here we discuss current progress and challenges in understanding the stressors that induce senescence in vivo, the cell types that are prone to senesce, and the autocrine and paracrine properties of senescent cells in the contexts of aging and age-related diseases as well as disease therapy. PMID:26646499

  5. Cellular senescence in aging and age-related disease: from mechanisms to therapy.

    PubMed

    Childs, Bennett G; Durik, Matej; Baker, Darren J; van Deursen, Jan M

    2015-12-01

    Cellular senescence, a process that imposes permanent proliferative arrest on cells in response to various stressors, has emerged as a potentially important contributor to aging and age-related disease, and it is an attractive target for therapeutic exploitation. A wealth of information about senescence in cultured cells has been acquired over the past half century; however, senescence in living organisms is poorly understood, largely because of technical limitations relating to the identification and characterization of senescent cells in tissues and organs. Furthermore, newly recognized beneficial signaling functions of senescence suggest that indiscriminately targeting senescent cells or modulating their secretome for anti-aging therapy may have negative consequences. Here we discuss current progress and challenges in understanding the stressors that induce senescence in vivo, the cell types that are prone to senesce, and the autocrine and paracrine properties of senescent cells in the contexts of aging and age-related diseases as well as disease therapy.

  6. Relative age effects in Japanese baseball: an historical analysis.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2013-08-01

    The present study investigated the existence of the relative age effect, a biased distribution of birth dates, in Japanese professional baseball players born from 1911 to 1980. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. Thus, athletes were divided into four groups based on their month of birth; quarters Q1 (April-June), Q2 (July-September), Q3 (October-December), and Q4 (January-March of the following year). There were statistically biased distributions of birth dates among players born in the 1940s and subsequent decades (medium effects), and similar (but small) relative age effects were observed among players born in the 1910s, 1920s, and 1930s. The magnitude of the relative age effect changed with time, and socio-cultural factors such as international competition and media coverage may have contributed greatly to this effect.

  7. Relative age effects in Japanese baseball: an historical analysis.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2013-08-01

    The present study investigated the existence of the relative age effect, a biased distribution of birth dates, in Japanese professional baseball players born from 1911 to 1980. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. Thus, athletes were divided into four groups based on their month of birth; quarters Q1 (April-June), Q2 (July-September), Q3 (October-December), and Q4 (January-March of the following year). There were statistically biased distributions of birth dates among players born in the 1940s and subsequent decades (medium effects), and similar (but small) relative age effects were observed among players born in the 1910s, 1920s, and 1930s. The magnitude of the relative age effect changed with time, and socio-cultural factors such as international competition and media coverage may have contributed greatly to this effect. PMID:24422356

  8. Age related changes in steroid receptors on cultured lung fibroblasts

    SciTech Connect

    Barile, F.A.; Bienkowski, R.S.

    1986-03-05

    The number of high affinity glucocorticoid receptors (Ro) on human fetal lung fibroblasts decreases as the cells age in vitro, and it has been suggested that these cell systems may be useful models of age-related changes in vivo. They examined the relation between change in Ro with in vitro aging and donor age. Confluent monolayers of lung fibroblasts at various population doubling levels (PDL), were incubated with (/sup 3/H)-dexamethasone ((/sup 3/H)Dex) either alone or with excess (.01 mM) Dex. Specific binding was calculated as the difference between radioactivity in cells incubated with and without unlabeled Dex; Scatchard plots were used to analyze the data. Ro, measured as fmol (/sup 3/H)Dex/10/sup 6/ cells, for two lines of human fetal cells (HFL-1 and MRC-5) decreased with increasing age in vitro. However, human newborn (CRL-1485) and adult (CCL-201) cells and fetal rabbit cells (FAB-290), showed increases in Ro with continuous passage. For each cell line, the affinity constant (K/sub d/) did not change significantly with passage. They conclude that the direction of changes in steroid receptor levels on cells aging in vitro is influenced by donor age and species. Caution should be used in applying results obtained from model systems to aging organisms.

  9. Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations

    PubMed Central

    Goossens, Tine; Vercammen, Charlotte; Wouters, Jan; van Wieringen, Astrid

    2016-01-01

    As people age, speech perception problems become highly prevalent, especially in noisy situations. In addition to peripheral hearing and cognition, temporal processing plays a key role in speech perception. Temporal processing of speech features is mediated by synchronized activity of neural oscillations in the central auditory system. Previous studies indicate that both the degree and hemispheric lateralization of synchronized neural activity relate to speech perception performance. Based on these results, we hypothesize that impaired speech perception in older persons may, in part, originate from deviances in neural synchronization. In this study, auditory steady-state responses that reflect synchronized activity of theta, beta, low and high gamma oscillations (i.e., 4, 20, 40, and 80 Hz ASSR, respectively) were recorded in young, middle-aged, and older persons. As all participants had normal audiometric thresholds and were screened for (mild) cognitive impairment, differences in synchronized neural activity across the three age groups were likely to be attributed to age. Our data yield novel findings regarding theta and high gamma oscillations in the aging auditory system. At an older age, synchronized activity of theta oscillations is increased, whereas high gamma synchronization is decreased. In contrast to young persons who exhibit a right hemispheric dominance for processing of high gamma range modulations, older adults show a symmetrical processing pattern. These age-related changes in neural synchronization may very well underlie the speech perception problems in aging persons. PMID:27378906

  10. Age-related changes in ultra-triathlon performances

    PubMed Central

    2012-01-01

    Background The age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in ultra-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron ultra-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron ultra-triathlon (38-km swimming, 1,800-km cycling and 420-km running). Methods The age and performances of 423 male Triple Iron ultra-triathletes and 119 male Deca Iron ultra-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA. Results The mean age of the finishers was significantly higher for Deca Iron ultra-triathletes (41.3 ± 3.1 years) compared to a Triple Iron ultra-triathletes (38.5 ± 3.3 years) (P < 0.05). For both ultra-distances, the fastest overall race times were achieved between the ages of 25 and 44 years. Deca Iron ultra-triathletes achieved the same level of performance in swimming and cycling between 25 and 54 years of age. Conclusions The magnitudes of age-related declines in performance in the three disciplines of ultra-triathlon differ slightly between Triple and Deca Iron ultra-triathlon. Although the ages of Triple Iron ultra-triathletes were on average younger compared to Deca Iron ultra-triathletes, the fastest race times were achieved between 25 and 44 years for both distances. Further studies should investigate the motivation and training of ultra-triathletes to gain better insights in ultra-triathlon performance. PMID:23849327

  11. DNA-aptamers raised against AGEs as a blocker of various aging-related disorders.

    PubMed

    Yamagishi, Sho-Ichi; Taguchi, Kensei; Fukami, Kei

    2016-08-01

    A non-enzymatic reaction between sugars or aldehydes and the amino groups of proteins, lipids and nucleic acids contributes to the aging of macromolecules, which could impair their structural integrity and function. This process begins with the conversion of reversible Schiff base adducts, and then to more stable, covalently-bound Amadori rearrangement products. Over a course of days to weeks, these early glycation products undergo further reactions, such as rearrangements and dehydration to become irreversibly crossed-linked, fluorescent protein derivatives termed advanced glycation end products (AGEs). The formation and accumulation of AGEs have been known to progress in a physiological aging process and at an accelerated rate under hyperglycemic, inflammatory and oxidative stress conditions. There is a growing body of evidence that AGEs and their receptor RAGE interaction play a role in the pathogenesis of various devastating disorders, including cardiovascular disease, Alzheimer's disease, insulin resistance, osteoporosis and cancer growth and metastasis. Furthermore, diet has been recently recognized as a major environmental source of AGEs that could also elicit pro-inflammatory reactions, thereby being involved in organ damage in vivo. Therefore, inhibition of AGE formation and/or blockade of the interaction of AGEs with RAGE may be a novel therapeutic target for aging-related disorders. This article discusses a potential utility of DNA-aptamers raised against AGEs for preventing aging and/or diabetes-associated organ damage, especially focusing on diabetic microvascular complications, vascular remodeling, metabolic derangements, and melanoma growth and expansion in animal models. PMID:27338620

  12. Aging-related differences in chondrocyte viscoelastic properties.

    PubMed

    Steklov, Nikolai; Srivastava, Ajay; Sung, K L P; Chen, Peter C; Lotz, Martin K; D'Lima, Darryl D

    2009-06-01

    The biomechanical properties of articular cartilage change profoundly with aging. These changes have been linked with increased potential for cartilage degeneration and osteoarthritis. However, less is known about the change in biomechanical properties of chondrocytes with increasing age. Cell stiffness can affect mechanotransduction pathways and may alter cell function. We measured aging-related changes in the biomechanical properties of chondrocytes. Human chondrocytes were isolated from knee articular cartilage within 48 hours after death or from osteochondral specimens obtained from knee arthroplasty. Cells were divided into two age groups: between 18 and 35 years (18 - 35); and greater than 55 years (55+) of age. The 55+ group was further subdivided based on visual grade of osteoarthritis: normal (N) or osteoarthritic (OA). The viscoelastic properties of the cell were measured using the previously described micropipette cell aspiration technique. The equilibrium modulus, instantaneous modulus, and apparent viscosity were significantly higher in the 55+ year age group than in the 18 - 35 age group. On the other hand, no differences were found in the equilibrium modulus, instantaneous modulus, or apparent viscosity between the N and OA groups. The increase in cell stiffness can be attributed to altered mechanical properties of the cell membrane, the cytoplasm, or the cytoskeleton. Increased stiffness has been reported in osteoarthritic chondrocytes, which in turn has been attributed to the actin cytoskeleton. A similar mechanism may be responsible for our finding of increased stiffness in aging chondrocytes. With advancing age, changes in the biomechanical properties of the cell could alter molecular and biochemical responses.

  13. eNOS-uncoupling in age-related erectile dysfunction

    PubMed Central

    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 ‘young’ (4-month-old) and ‘aged’ (19-month-old) rats were treated with a BH4 precursor sepiapterin (10 mg/kg intraperitoneally) or vehicle for 4 days. After 1-day washout, erectile function was assessed in response to electrical stimulation of the cavernous nerve. Endothelial dysfunction (eNOS uncoupling) and oxidative stress (thiobarbituric acid reactive substances, TBARS) were measured by conducting western blot in penes samples. Erectile response was significantly reduced in aged rats, whereas eNOS uncoupling and TBARS production were significantly increased in the aged rat penis compared with young rats. Sepiapterin significantly improved erectile response in aged rats and prevented increase in TBARS production, but did not affect eNOS uncoupling in the penis of aged rats. These findings suggest that aging induces eNOS uncoupling in the penis, resulting in increased oxidative stress and ED. PMID:21289638

  14. Human Aging Is a Metabolome-related Matter of Gender.

    PubMed

    Jové, Mariona; Maté, Ianire; Naudí, Alba; Mota-Martorell, Natalia; Portero-Otín, Manuel; De la Fuente, Mónica; Pamplona, Reinald

    2016-05-01

    A molecular description of the mechanisms by which aging is produced is still very limited. Here, we have determined the plasma metabolite profile by using high-throughput metabolome profiling technologies of 150 healthy humans ranging from 30 to 100 years of age. Using a nontargeted approach, we detected 2,678 metabolite species in plasma, and the multivariate analyses separated perfectly two groups indicating a specific signature for each gender. In addition, there is a set of gender-shared metabolites, which change significantly during aging with a similar tendency. Among the identified molecules, we found vitamin D2-related compound, phosphoserine (40:5), monoacylglyceride (22:1), diacylglyceride (33:2), and resolvin D6, all of them decreasing with the aging process. Finally, we found three molecules that directly correlate with age and seven that inversely correlate with age, independently of gender. Among the identified molecules (6 of 10 according to exact mass and retention time), we found a proteolytic product (l-γ-glutamyl-l-leucine), which increased with age. On the contrary, a hydroxyl fatty acid (25-hydroxy-hexacosanoic), a polyunsaturated fatty acid (eicosapentaenoic acid), two phospholipids (phosphocholine [42:9]and phosphoserine [42:3]) and a prostaglandin (15-keto-prostaglandin F2α) decreased with aging. These results suggest that lipid species and their metabolism are closely linked to the aging process.

  15. Caspase-2 Deficiency Enhances Aging-Related Traits in Mice

    PubMed Central

    Zhang, Yingpei; Padalecki, Susan S; Chaudhuri, Asish R; Waal, Eric De; Goins, Beth A; Grubbs, Barry; Ikeno, Yuji; Richardson, Arlan; Mundy, Gregory R; Herman, Brian

    2007-01-01

    Alteration of apoptotic activity has been observed in a number of tissues in aging mammals, but it remains unclear whether and/or how apoptosis may affect aging. Caspase-2 is a member of the cysteine protease family that plays a critical role in apoptosis. To understand the impact of compromised apoptosis function on mammalian aging, we conducted a comparative study on caspase-2 deficient mice and their wild-type littermates with a specific focus on the aging-related traits at advanced ages. We found that caspase-2 deficiency enhanced a number of traits commonly seen in premature aging animals. Loss of caspase-2 was associated with shortened maximum lifespan, impaired hair growth, increased bone loss, and reduced body fat content. In addition, we found that the livers of caspase-2 deficient mice had higher levels of oxidized proteins than those of age-matched wild-type mice, suggesting that caspase-2 deficiency compromised the animal's ability to clear oxidatively damaged cells. Collectively, these results suggest that caspase-2 deficiency affects aging in the mice. This study thus demonstrates for the first time that disruption of a key apoptotic gene has a significant impact on aging. PMID:17188333

  16. Awareness, Knowledge, and Concern about Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Cimarolli, Verena R.; Laban-Baker, Allie; Hamilton, Wanda S.; Stuen, Cynthia

    2012-01-01

    Age-related macular degeneration (AMD)--a common eye disease causing vision loss--can be detected early through regular eye-health examinations, and measures can be taken to prevent visual decline. Getting eye examinations requires certain levels of awareness, knowledge, and concern related to AMD. However, little is known about AMD-related…

  17. Isolation and characterization of process-related impurities and degradation products in larotaxel.

    PubMed

    Che, Xin; Shen, Li; Xu, Hui; Liu, Ke

    2011-07-15

    The isolation and characterization of the process related impurities and degradation products of larotaxel drug substance were described. Forced degradation of larotaxel was carried out under acidic, basic, oxidation, light and thermal conditions to assess the nature of the impurities. The pure impurities were obtained by semi-preparative LC isolation and analyzed by NMR and MS. The structures of impurities were confirmed as 7,8-cyclopropyl baccatin III, 10-deacetyl larotaxel, 10-deacetyl-7, 8-cyclopropyl baccatin III, 7-acetyl-8-methyl larotaxel and 2',13-bissidechain larotaxel.

  18. Discover the network mechanisms underlying the connections between aging and age-related diseases.

    PubMed

    Yang, Jialiang; Huang, Tao; Song, Won-Min; Petralia, Francesca; Mobbs, Charles V; Zhang, Bin; Zhao, Yong; Schadt, Eric E; Zhu, Jun; Tu, Zhidong

    2016-01-01

    Although our knowledge of aging has greatly expanded in the past decades, it remains elusive why and how aging contributes to the development of age-related diseases (ARDs). In particular, a global mechanistic understanding of the connections between aging and ARDs is yet to be established. We rely on a network modelling named "GeroNet" to study the connections between aging and more than a hundred diseases. By evaluating topological connections between aging genes and disease genes in over three thousand subnetworks corresponding to various biological processes, we show that aging has stronger connections with ARD genes compared to non-ARD genes in subnetworks corresponding to "response to decreased oxygen levels", "insulin signalling pathway", "cell cycle", etc. Based on subnetwork connectivity, we can correctly "predict" if a disease is age-related and prioritize the biological processes that are involved in connecting to multiple ARDs. Using Alzheimer's disease (AD) as an example, GeroNet identifies meaningful genes that may play key roles in connecting aging and ARDs. The top modules identified by GeroNet in AD significantly overlap with modules identified from a large scale AD brain gene expression experiment, supporting that GeroNet indeed reveals the underlying biological processes involved in the disease. PMID:27582315

  19. Discover the network mechanisms underlying the connections between aging and age-related diseases

    PubMed Central

    Yang, Jialiang; Huang, Tao; Song, Won-min; Petralia, Francesca; Mobbs, Charles V.; Zhang, Bin; Zhao, Yong; Schadt, Eric E.; Zhu, Jun; Tu, Zhidong

    2016-01-01

    Although our knowledge of aging has greatly expanded in the past decades, it remains elusive why and how aging contributes to the development of age-related diseases (ARDs). In particular, a global mechanistic understanding of the connections between aging and ARDs is yet to be established. We rely on a network modelling named “GeroNet” to study the connections between aging and more than a hundred diseases. By evaluating topological connections between aging genes and disease genes in over three thousand subnetworks corresponding to various biological processes, we show that aging has stronger connections with ARD genes compared to non-ARD genes in subnetworks corresponding to “response to decreased oxygen levels”, “insulin signalling pathway”, “cell cycle”, etc. Based on subnetwork connectivity, we can correctly “predict” if a disease is age-related and prioritize the biological processes that are involved in connecting to multiple ARDs. Using Alzheimer’s disease (AD) as an example, GeroNet identifies meaningful genes that may play key roles in connecting aging and ARDs. The top modules identified by GeroNet in AD significantly overlap with modules identified from a large scale AD brain gene expression experiment, supporting that GeroNet indeed reveals the underlying biological processes involved in the disease. PMID:27582315

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

    PubMed

    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.

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

    PubMed Central

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

    2013-01-01

    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. PMID:24131799

  2. The Marmoset as a Model of Aging and Age-Related Diseases

    PubMed Central

    Tardif, Suzette D.; Mansfield, Keith G.; Ratnam, Rama; Ross, Corinna N.; Ziegler, Toni E.

    2013-01-01

    The common marmoset (Callithrix jacchus) is poised to become a standard nonhuman primate aging model. With an average lifespan of 5 to 7 years and a maximum lifespan of 16.5 years, marmosets are the shortest-lived anthropoid primates. They display age-related changes in pathologies that mirror those seen in humans, such as cancer, amyloidosis, diabetes, and chronic renal disease. They also display predictable age-related differences in lean mass, calf circumference, circulating albumin, hemoglobin, and hematocrit. Features of spontaneous sensory and neurodegenerative change—for example, reduced neurogenesis, β-amyloid deposition in the cerebral cortex, loss of calbindin D28k binding, and evidence of presbycusis—appear between the ages of 7 and 10 years. Variation among colonies in the age at which neurodegenerative change occurs suggests the interesting possibility that marmosets could be specifically managed to produce earlier versus later occurrence of degenerative conditions associated with differing rates of damage accumulation. In addition to the established value of the marmoset as a model of age-related neurodegenerative change, this primate can serve as a model of the integrated effects of aging and obesity on metabolic dysfunction, as it displays evidence of such dysfunction associated with high body weight as early as 6 to 8 years of age. PMID:21411858

  3. The age-related emergence of cranial morphological variation.

    PubMed

    Wood, Carolan

    2015-06-01

    Evaluation of ancestry from skeletal remains is problematic for subadults because of a lack of systematic research on the topic. This paper addresses the need for systematic research into geographical variation through childhood and puberty through the examination of the emergence of cranial morphological traits through an analysis of 756 subadults from 4 months in utero to <20 years of age. The first appearance of a trait, changes in the morphology of a trait through time, age stability as related to the age of maturation of the structure, and the developmental mechanisms and processes that cause traits to appear together are addressed. Most traits are influenced by patterns of growth and development and become age stable in conjunction with the larger growth complexes of which they are a part. Geographic cranial variation is present from an early age. Population specific differences in the expression of most traits are apparent from their first appearance.

  4. Ageism, age relations, and garment industry work in Montreal.

    PubMed

    McMullin, J A; Marshall, V W

    2001-02-01

    This study examined the complexities of age relations at work. Garment workers believed that their fate was linked to ageism and that their work experience was discounted by management. Managers wanted to be rid of older workers because they commanded higher wages than younger workers. The issue was cost reduction, and age was implicated unintendedly. Still, managers seemed to use stereotypical images to discourage older workers and they did not organize work routines to facilitate the adaptation of them. Instead, they subcontracted the easy jobs, relying on the experience of the older employees for difficult work while not adapting the workplace. Theoretically, the authors argue that ageism and age discrimination can best be understood through a recognition of the importance of structured age relations and human agency.

  5. Relational learning and transitive expression in aging and amnesia.

    PubMed

    Ryan, Jennifer D; D'Angelo, Maria C; Kamino, Daphne; Ostreicher, Melanie; Moses, Sandra N; Rosenbaum, R Shayna

    2016-02-01

    Aging has been associated with a decline in relational memory, which is critically supported by the hippocampus. By adapting the transitivity paradigm (Bunsey and Eichenbaum (1996) Nature 379:255-257), which traditionally has been used in nonhuman animal research, this work examined the extent to which aging is accompanied by deficits in relational learning and flexible expression of relational information. Older adults' performance was additionally contrasted with that of amnesic case DA to understand the critical contributions of the medial temporal lobe, and specifically, the hippocampus, which endures structural and functional changes in healthy aging. Participants were required to select the correct choice item (B versus Y) based on the presented sample item (e.g., A). Pairwise relations must be learned (A->B, B->C, C->D) so that ultimately, the correct relations can be inferred when presented with a novel probe item (A->C?Z?). Participants completed four conditions of transitivity that varied in terms of the degree to which the stimuli and the relations among them were known pre-experimentally. Younger adults, older adults, and DA performed similarly when the condition employed all pre-experimentally known, semantic, relations. Older adults and DA were less accurate than younger adults when all to-be-learned relations were arbitrary. However, accuracy improved for older adults when they could use pre-experimentally known pairwise relations to express understanding of arbitrary relations as indexed through inference judgments. DA could not learn arbitrary relations nor use existing knowledge to support novel inferences. These results suggest that while aging has often been associated with an emerging decline in hippocampal function, prior knowledge can be used to support novel inferences. However, in case DA, significant damage to the hippocampus likely impaired his ability to learn novel relations, while additional damage to ventromedial prefrontal and

  6. Procyanidins extracted from the lotus seedpod ameliorate age-related antioxidant deficit in aged rats.

    PubMed

    Xu, Jiqu; Rong, Shuang; Xie, Bijun; Sun, Zhida; Zhang, Li; Wu, Hailei; Yao, Ping; Hao, Liping; Liu, Liegang

    2010-03-01

    The alleviative effect of procyanidins extracted from the lotus seedpod (LSPC) on oxidative stress in various tissues was evaluated by determining the activities of the antioxidant enzymes and the content of reduced glutathione (GSH) in heart, liver, lung, kidney, skeletal muscle, and serum in aged rats. Aging led to antioxidant deficit in various tissues in this study, which is confirmed by remarkable increased lipid peroxidation, whereas the change patterns of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and GSH were diverse in various tissues of aged rats. LSPC treatment (50 and 100 mg/kg body weight) modified the activity of SOD, CAT, and GPx as well as GSH content alteration in these tissues, which reversed the age-related antioxidant deficit in aged rats. However, the regulatory patterns on the activities of these enzymes and GSH content by LSPC treatment were different according to the tissues in aged rats.

  7. Common cell biologic and biochemical changes in aging and age-related diseases of the eye: Toward new therapeutic approaches to age-related ocular diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reviews of information about age related macular degeneration (AMD), cataract, and glaucoma make it apparent that while each eye tissue has its own characteristic metabolism, structure and function, there are common perturbations to homeostasis that are associated with age-related dysfunction. The c...

  8. Age-Related and Sex-Related Differences in Hand and Pinch Grip Strength in Adults

    ERIC Educational Resources Information Center

    Puh, Urska

    2010-01-01

    The purpose of the study was to quantify age-related changes in hand grip strength and three types of pinch grip strength (key pinch, tip pinch, and palmar pinch) among male and female participants. The study included 199 healthy participants (100 females, 99 males) aged 20-79 years, who were divided into four age groups. The Baseline Hydraulic…

  9. Age-Related Neurochemical Changes in the Vestibular Nuclei.

    PubMed

    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. PMID:26973593

  10. Age-Related Neurochemical Changes in the Vestibular Nuclei

    PubMed Central

    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. PMID:26973593

  11. A validated stability-indicating RP-HPLC method for levofloxacin in the presence of degradation products, its process related impurities and identification of oxidative degradant.

    PubMed

    Lalitha Devi, M; Chandrasekhar, K B

    2009-12-01

    The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of levofloxacin as well as its related substances determination in bulk samples, pharmaceutical dosage forms in the presence of degradation products and its process related impurities. Forced degradation studies were performed on bulk sample of levofloxacin as per ICH prescribed stress conditions using acid, base, oxidative, water hydrolysis, thermal stress and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed during oxidative stress and the degradation product formed was identified by LCMS/MS, slight degradation in acidic stress and no degradation was observed in other stress conditions. The chromatographic method was optimized using the samples generated from forced degradation studies and the impurity spiked solution. Good resolution between the peaks corresponds to process related impurities and degradation products from the analyte were achieved on ACE C18 column using the mobile phase consists a mixture of 0.5% (v/v) triethyl amine in sodium dihydrogen orthophosphate dihydrate (25 mM; pH 6.0) and methanol using a simple linear gradient. The detection was carried out at 294 nm. The limit of detection and the limit of quantitation for the levofloxacin and its process related impurities were established. The stressed test solutions were assayed against the qualified working standard of levofloxacin and the mass balance in each case was in between 99.4 and 99.8% indicating that the developed LC method was stability indicating. Validation of the developed LC method was carried out as per ICH requirements. The developed LC method was found to be suitable to check the quality of bulk samples of levofloxacin at the time of batch release and also during its stability studies (long term and accelerated stability).

  12. Age-related differences in updating working memory.

    PubMed

    Van der Linden, M; Brédart, S; Beerten, A

    1994-02-01

    Age-related differences in updating working memory were investigated in two experiments using a running memory task. In the first experiment, the task of the young and elderly subjects was to watch strings of four to 10 consonants and then to recall serially the four most recent items. Results revealed no age effect. A second experiment was then carried out using a memory load that was close to memory span: lists of six to 12 consonants were presented and subjects had to recall the last six items. Age interacted with list length but not with serial position. This dissociation is discussed in terms of Baddeley's (1986) model.

  13. A New Class of Risk-Importance Measures to Support Reactor Aging Management and the Prioritization of Materials Degradation Research

    SciTech Connect

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2010-06-07

    As the US fleet of light water reactors ages, the risks of operation might be expected to increase. Although probabilistic risk assessment has proven a critical resource in risk-informed regulatory decision-making, limitations in current methods and models have constrained their prospective value in reactor aging management. These limitations stem principally from the use of static component failure rate models (which do not allow the impact of component aging on failure rates to be represented) and a very limited treatment of passive components (which would be expected to have an increasingly significant risk contribution in an aging system). Yet, a PRA captures a substantial knowledge base that could be of significant value in addressing plant aging. In this paper we will describe a methodology and a new class of risk importance measures that allow the use of an existing PRA model to support the management of plant aging, the prioritization of improvements to non-destructive examination and monitoring techniques, and the establishment of research emphases in materials science. This methodology makes use of data resources generated under the USNRC Proactive Management of Materials Degradation program which addresses the anticipated effects of numerous aging degradation mechanisms on a wide variety of component types.

  14. Age-related alterations in retinal neurovascular and inflammatory transcripts

    PubMed Central

    Van Kirk, Colleen A.; VanGuilder, Heather D.; Young, Megan; Farley, Julie A.; Sonntag, William E.

    2011-01-01

    Purpose Vision loss is one of the most common complications of aging, even in individuals with no diagnosed ocular disease. Increasing age induces structural alterations and functional impairments in retinal neurons and microvasculature linked to the activation of proinflammatory signaling pathways. Commonalities between the effects of aging and those observed with diabetes, including visual impairment, vascular dysfunction, and increased inflammatory response, have led to the hypothesis that diabetes-associated pathologies reflect an “advanced aging” phenotype. The goal of this study was to investigate the effects of aging on retinal mRNA expression of neurovascular and inflammatory transcripts previously demonstrated to be regulated with diabetes. Methods The relative expression of 36 genes of interest previously identified as consistently regulated with diabetes was assessed in retinas of Young (3 month), Adult (12 month), and Aged (26 month) Fischer 344 x Brown Norway (F1) hybrid rats using quantitative PCR. Serum samples obtained at sacrifice were assayed to determine serum glucose levels. Results Eleven inflammation- and microvascular-related genes previously demonstrated to be upregulated in young diabetic rats (complement component 1 s subcomponent [C1s], chitinase 3-like 1 [Chi3L1], endothelin 2 [Edn2], guanylate nucleotide binding protein 2 [Gbp2], glial fibrillary acidic protein [Gfap], intracellular adhesion molecule 1 [Icam1], janus kinase 3 [Jak3], lipopolysaccharide-induced TNF factor [Litaf], complement 1-inhibitor [Serping1], signal transducer and activator of transcription 3 [Stat3], tumor necrosis factor receptor subfamily member 12a [Tnfrsf12a]) demonstrated progressively increasing retinal expression in aged normoglycemic rats. Additionally, two neuronal function–related genes (glutamate receptor ionotropic NMDA 2A [Grin2a] and polycomb group ring finger 1 [Pcgf1]) and one inflammation-related gene (pigment epithelium-derived growth

  15. HPLC method for the determination of emtricitabine and related degradation substances.

    PubMed

    Hamarapurkar, P D; Parate, Abhijeet N

    2013-01-01

    A new high-performance liquid chromatography method has been developed for a stability-indicating assay for emtricitabine and the quantification of its related substances. Good resolution between the peaks corresponds to process-related impurities, and degradation products from the analyte were achieved on a C18 HiQSil column using a mobile phase consisting of ammonium formate (pH 4.2) and methanol in a gradient elution mode. The detection was conducted at a wavelength of 280 nm. The investigated validation elements showed that the method has acceptable specificity, accuracy, linearity, precision, robustness and sensitivity. Detection and quantification limits were established at 0.02 and 0.05 µg/mL, respectively. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal decomposition to determine the degradation behavior. Extensive degradation was found under acid, alkaline and oxidative stress. Five related substances were consistently monitored under stress conditions. Because the method effectively separates the drug from its degradation products, it can be used as a stability indicating method and for purity control of emtricitabine.

  16. Age related distributive justice and claims on resources.

    PubMed

    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.

  17. Classical Cepheid Pulsation Models. X. The Period-Age Relation

    NASA Astrophysics Data System (ADS)

    Bono, G.; Marconi, M.; Cassisi, S.; Caputo, F.; Gieren, W.; Pietrzynski, G.

    2005-03-01

    We present new period-age (PA) and period-age-color (PAC) relations for fundamental and first-overtone classical Cepheids. Current predictions rely on homogeneous sets of evolutionary and pulsation models covering a broad range of stellar masses and chemical compositions. We found that PA and PAC relations present a mild dependence on metal content. Moreover, the use of different PA and PAC relations for fundamental and first-overtone Cepheids improves the accuracy of age estimates in the short-period (logP<1) range (old Cepheids), because they present smaller intrinsic dispersions. At the same time, the use of the PAC relations improves the accuracy in the long-period (logP>=1) range (young Cepheids), since they account for the position of individual objects inside the instability strip. We performed a detailed comparison between evolutionary and pulsation ages for a sizable sample of LMC (15) and SMC (12) clusters which host at least two Cepheids. In order to avoid deceptive uncertainties in the photometric absolute zero point, we adopted the homogeneous set of B, V, and I data for clusters and Cepheids collected by OGLE. We also adopted the same reddening scale. The different age estimates agree at the level of 20% for LMC clusters and of 10% for SMC clusters. We also performed the same comparison for two Galactic clusters (NGC 6067, NGC 7790), and the difference in age is smaller than 20%. These findings support the use of PA and PAC relations to supply accurate estimates of individual stellar ages in the Galaxy and in external Galaxies. The main advantage of this approach is its independence from the distance.

  18. Later developments: molecular keys to age-related memory impairment.

    PubMed

    Barad, Mark

    2003-01-01

    Age-related memory impairment, a cognitive decline not clearly related to any gross pathology, is progressive and widespread in the population, although not universal. While the mechanisms of learning and memory remain incompletely understood, the study of their molecular mechanisms is already yielding promising approaches toward therapy for such "normal" declines in the efficiency of learning. This review presents the rationale and results for two such approaches. One approach, partial inhibition of the type IV cAMP specific phosphodiesterase, appears to act indirectly. Although little evidence supports an age-related decline in this system, considerable evidence indicates that this approach can facilitate the transition from short-term to long-term memory and thus counterbalance defects in long-term memory, which may be due to other causes. A second approach, inhibition of l-type voltage gated calcium channels (LVGCCs) may be a specific corrective for a molecular pathology of aging, as substantial evidence indicates that an ongoing increase occurs throughout the lifespan in the density of these channels in hippocampal pyramidal cells, with a concomitant reduction in cellular excitability. Because LVGCCs are also crucial to extinction, a paradigm of inhibitory learning, age-related memory impairment may be an unfortunate side effect of a developmental process necessary to the maturation of the ability to suppress inappropriate behavior, an interpretation consistent with the antagonistic pleiotropy theory of aging.

  19. Early age-related changes in episodic memory retrieval as revealed by event-related potentials.

    PubMed

    Guillaume, Cécile; Clochon, Patrice; Denise, Pierre; Rauchs, Géraldine; Guillery-Girard, Bérengère; Eustache, Francis; Desgranges, Béatrice

    2009-01-28

    Familiarity is better preserved than recollection in ageing. The age at which changes first occur and the slope of the subsequent decline, however, remain unclear. In this study, we investigated changes in episodic memory, by using event-related potentials (ERPs) in young (m=24), middle-aged (m=58) and older (m=70) adults. Although behavioural performance did not change before the age of 65 years, changes in ERP correlates were already present in the middle-aged adults. The ERP correlates of recollection and monitoring processes were the first to be affected by ageing, with a linear decrease as age increased. Conversely, the ERP correlate of familiarity remained unchanged, at least up to the age of 65 years. These results suggest a differential time course for the age effects on episodic retrieval. PMID:19104457

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

    PubMed Central

    Davalli, Pierpaola; Mitic, Tijana; Caporali, Andrea; Lauriola, Angela; D'Arca, Domenico

    2016-01-01

    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. PMID:27247702

  1. Age-related changes in postural control to the demands of a precision task.

    PubMed

    Yeh, Ting-Ting; Cinelli, Michael E; Lyons, James L; Lee, Timothy D

    2015-12-01

    Optimal sensorimotor integration is needed to maintain the precision of a visuomotor postural task. Furthermore, cognitive resources have been suggested to be involved in maintaining balance, especially in older adults. This study investigated how older and younger adults differed in employing sensorimotor strategies in a dual-task situation. Older (age 65-84 years) and younger adults (age 19-30 years) performed a visually-based, postural tracking task in different body orientations (from 0° to 45°), which necessitated slightly different task goals. On some trials, participants performed a concurrent silent arithmetic task with the visuomotor tracking task. The results demonstrated that sensorimotor control declined with age. Older adults showed greater medial-lateral center of pressure variability compared to younger adults in the precision task. Younger adults displayed a trend to decrease anterior-posterior variability, but older adults exhibited an opposite trend when the body orientation changed from 0° to 45°. The addition of a dual-task situation decreased overall postural variability in both age groups. Age-related changes in postural control may degrade the flexible coordination of the sensory feedback and motor execution. This study suggested that medial-lateral stability may be more sensitive to this age-related decline and may be closely associated with postural instability and falls.

  2. Age-related decline in emotional prosody discrimination: acoustic correlates.

    PubMed

    Mitchell, Rachel L C; Kingston, Rachel A

    2014-01-01

    It is now accepted that older adults have difficulty recognizing prosodic emotion cues, but it is not clear at what processing stage this ability breaks down. We manipulated the acoustic characteristics of tones in pitch, amplitude, and duration discrimination tasks to assess whether impaired basic auditory perception coexisted with our previously demonstrated age-related prosodic emotion perception impairment. It was found that pitch perception was particularly impaired in older adults, and that it displayed the strongest correlation with prosodic emotion discrimination. We conclude that an important cause of age-related impairment in prosodic emotion comprehension exists at the fundamental sensory level of processing.

  3. Accelerated aging studies of UHMWPE. I. Effect of resin, processing, and radiation environment on resistance to mechanical degradation.

    PubMed

    Edidin, A A; Herr, M P; Villarraga, M L; Muth, J; Yau, S S; Kurtz, S M

    2002-08-01

    The resin and processing route have been identified as potential variables influencing the mechanical behavior, and hence the clinical performance, of ultra-high molecular weight polyethylene (UHMWPE) orthopedic components. Researchers have reported that components fabricated from 1900 resin may oxidize to a lesser extent than components fabricated from GUR resin during shelf aging after gamma sterilization in air. Conflicting reports on the oxidation resistance for 1900 raise the question of whether resin or manufacturing method, or an interaction between resin and manufacturing method, influences the mechanical behavior of UHMWPE. We conducted a series of accelerated aging studies (no aging, aging in oxygen or in nitrogen) to systematically examine the influence of resin (GUR or 1900), manufacturing method (bulk compression molding or extrusion), and sterilization method (none, in air, or in nitrogen) on the mechanical behavior of UHMWPE. The small punch testing technique was used to evaluate the mechanical behavior of the materials, and Fourier transform infrared spectroscopy was used to characterize the oxidation in selected samples. Our study showed that the sterilization environment, aging condition, and specimen location (surface or subsurface) significantly affected the mechanical behavior of UHMWPE. Each of the three polyethylenes evaluated seem to degrade according to a similar pathway after artificial aging in oxygen and gamma irradiation in air. The initial ability of the materials to exhibit post-yield strain hardening was significantly compromised by degradation. In general, there were only minor differences in the aging behavior of molded and extruded GUR 1050, whereas the molded 1900 material seemed to degrade slightly faster than either of the 1050 materials.

  4. Involvement of cellular metabolism in age-related LTP modifications in rat hippocampal slices.

    PubMed

    Drulis-Fajdasz, Dominika; Wójtowicz, Tomasz; Wawrzyniak, Marcin; Wlodarczyk, Jakub; Mozrzymas, Jerzy W; Rakus, Dariusz

    2015-06-10

    Recent studies emphasized crucial role of astrocytic glycogen metabolism in regulation of synaptic transmission and plasticity in young animals. However, the interplay between age-related synaptic plasticity impairments and changes in energetic metabolism remains obscure. To address this issue, we investigated, in hippocampal slices of young (one month) and aged rats (20-22-months), the impact of glycogen degradation inhibition on LTP, mRNA expression for glycogen metabolism enzymes and morphology of dendritic spines. We show that, whereas in young hippocampi, inhibition of glycogen phosphorolysis disrupts the late phase of LTP in the Schaffer collateral-CA1 pathway, in aged rats, blockade of glycogen phosphorylase tends to enhance it. Gene expression for key energy metabolism enzymes, such as glycogen synthase and phosphorylase and glutamine synthetase showed marked differences between young and aged groups and changes in expression of these enzymes preceded plasticity phenomena. Interestingly, in the aged group, a prominent expression of these enzymes was found also in neurons. Concluding, we show that LTP in the considered pathway is differentially modulated by metabolic processes in young and aging animals, indicating a novel venue of studies aiming at preventing cognitive decline during aging. PMID:26101857

  5. Time-related degradation, a key issue in nuclear plant safety evaluations

    SciTech Connect

    Bonzon, L.L.; Bustard, L.D.; Clough, R.L.; Gillen, K.T.

    1982-01-01

    Sandia National Laboratories is conducting a number of programs under NRC sponsorship which deal with safety-related equipment qualification issues, including the important aspect of aging. Among these is the Qualification Testing Evaluation (QTE) program which was probably the first to devote significant effort towards aging research and was one of the primary motivators leading to the Workshop. The thrust of the QTE aging efforts has been on elastomeric materials, typically used in electrical cables, seals, gaskets, and the like; currently, efforts are being pursued on plant ambient environments measurements, aging of electronics, and aging of motors. A brief status report is presented in this paper.

  6. Age related microsatellite instability in T cells from healthy individuals.

    PubMed

    Krichevsky, Svetlana; Pawelec, Graham; Gural, Alexander; Effros, Rita B; Globerson, Amiela; Yehuda, Dina Ben; Yehuda, Arie Ben

    2004-04-01

    Many immune functions decline with age and may jeopardize the elderly, as illustrated, for example by the significantly higher mortality rate from influenza in old age. Although innate and humoral immunity are affected by aging, it is the T cell compartment, which manifests most alterations. The mechanisms behind these alterations are still unclear, and several explanations have been offered including thymic involution and Telomere attrition leading to cell senescence. Age related accumulation of mutations has been documented and could serve as an additional mechanism of T cell dysfunction. One effective repair mechanism capable of rectifying errors in DNA replications is the mismatch repair (MMR) system. We previously reported a comparative examination of individual DNA samples from blood cells obtained at 10 year intervals from young and old subjects. We showed significantly higher rates of microsatellite instability (MSI), an indicator of MMR dysfunction in older subjects, compared to young. In the present study we confirm this result, using direct automated sequencing and in addition, we demonstrate that as CD8 lymphocytes from aged individuals, undergo repeated population doublings (PDs) in culture, they develop MSI. CD4 clones that also undergo repeated PDs in culture develop significant MSI as well. Elucidation of this previously unexplored facet of lymphocyte dynamics in relation to aging may help identify novel mechanisms of immunosenescence and pathways that could serve as targets for interventions to restore immune function.

  7. Dissecting simulated disc galaxies - II. The age-velocity relation

    NASA Astrophysics Data System (ADS)

    Martig, Marie; Minchev, Ivan; Flynn, Chris

    2014-09-01

    We study the relation between stellar ages and vertical velocity dispersion (the age-velocity relation, or AVR) in a sample of seven simulated disc galaxies. In our simulations, the shape of the AVR for stars younger than 9 Gyr depends strongly on the merger history at low redshift, with even 1:10-1:15 mergers being able to create jumps in the AVR (although these jumps might not be detectable if the errors on stellar ages are of the order of 30 per cent). For galaxies with a quiescent history at low redshift, we find that the vertical velocity dispersion rises smoothly for ages up to 8-9 Gyr, following a power law with a slope of ˜0.5, similar to what is observed in the solar neighbourhood by the Geneva-Copenhagen Survey. For these galaxies, we show that the slope of the AVR is not imprinted at birth, but is the result of subsequent heating. By contrast, in all our simulations, the oldest stars form a significantly different population, with a high velocity dispersion. These stars are usually born kinematically hot in a turbulent phase of intense mergers at high redshift, and also include some stars accreted from satellites. This maximum in σz is strongly decreased when age errors are included, suggesting that observations can easily miss such a jump with the current accuracy of age measurements.

  8. [The relationship between the polymorphism of immunity genes and both aging and age-related diseases].

    PubMed

    Ruan, Qing-Wei; Yu, Zhuo-Wei; Bao, Zhi-Jun; Ma, Yong-Xing

    2013-07-01

    Aging is acommon, progressive and irreversible state of multi-cell dysfunction. Immune aging mainly includes the declines of regenerative capacity and lymphoid lineage differentiation potential, the hyporesponsive to infection and vaccination, the hyperresponsive in the context of inflammatory pathology, and the increased risk of autoimmunity. The dysfunction of aged immune system accelerates the occurrence of aging and age-related diseases. The mutation of immunity genes that affect immune responses accelerates or slows aging process and age-related diseases. The frequencies of acquired immunity genes, such as immune protective HLA II DRB1*11 and DRB*16-associated haplotype, are increased in the longevity populations. The increased susceptibility of immune inflammatory response, morbidity and mortality in the elderly is often associated with decreased frequencies of anti-inflammatory factor IL-10 -1082G allele, TNF-β1 haplotype cnd10T/C, cnd25G/G, -988C/C, -800G/A, low proinflammatory fator TNFa level related extended TNF-A genotype -1031C/C, -863C/A, -857C/C, IL-6-174 CC and IFN-γ+874 T allele as well. The innate immunity genes, such as highly expressed anti-inflammatory +896 G KIR4 allele, CCR5Δ32 variant, -765 C Cox-2 allele, -1708 G and 21 C 5-Lox alleles are detected in centenarians. In age-related diseases, a higher CMV-specific IgG antibody level in elderly individuals is associated with a decreased frequency of KIR haplotypes KIR2DS5 and A1B10 and an increased frequency of MBL2 haplotypes LYPB, LYQC and HYPD that result in the absence of MBL2 protein. The increased frequencies of CRP ATG haplotypes and CFH 402 His allele indicate high mortality in the elderly. In the present study, we review the advances in the polymorphism and haplotype of innate and adoptive immunity genes, and their association with both aging and age-related diseases. To strengthen the analysis of extended haplotypes, epigenetic studies of immunity genes and genetic study of

  9. Age-related changes in skin topography and microcirculation.

    PubMed

    Li, Li; Mac-Mary, Sophie; Marsaut, David; Sainthillier, Jean Marie; Nouveau, Stéphanie; Gharbi, Tijani; de Lacharriere, Olivier; Humbert, Philippe

    2006-03-01

    Skin topography and microvasculature undergo characteristic changes with age. Although several non-invasive bioengineering methods are currently available to measure them quantitatively, few publications have referred to their relationship with age in different anatomical sites. This study was carried out to observe the age-related changes of the skin topography and skin microcirculation. The microrelief was assessed with special processing software from scanning by interference fringe profilometry of silicone replicas performed on two sites (volar forearm and back of hand) on 50 female volunteers (aged 20-74 years who consisted of ten probands in each decade). The superficial vascular network of both sites was assessed by videocapillaroscopy, and the subpapillary vascular plexus was studied with laser Doppler flowmetry. Skin color, which is affected by blood flow, was observed by colorimeter. The skin roughness and the mean height between peak and valley increased with age. There were statistically significant differences between the evaluated sites. This study also shows that the capillary loops in the dermal papillae decrease but the subpapillary plexus increase with age. The interference fringe profilometry associated with videocapillaroscopy may be useful and accurate to measure the efficacy of medical or cosmetic products to delay skin aging.

  10. The Chromospheric Activity-Age Relation for M Dwarf Stars

    NASA Astrophysics Data System (ADS)

    Silvestri, N. M.; Oswalt, T. D.; Hawley, S. L.

    2000-12-01

    We present preliminary results from our study in which we use moderate resolution spectroscopy to determine the correlation between the chromospheric activity and age of M dwarf stars in wide binary systems. We have observed ~50 M dwarf stars from our sample with the Apache Point Observatory 3.5-m telescope. We measure the ratio of Hα luminosity to the bolometric luminosity (LHα /Lbol) of the M dwarf---a measure of activity that is proven to correlate well with age. This project is unique in that it will extend the chromospheric activity-age relation of low-mass main sequence stars beyond the ages provided by cluster methods. The ages so determined are also independent of the uncertainties in cluster age determinations. The technique has the potential to improve by at least a factor of two the precision and the range over which ages can currently be determined for main sequence stars. Work on this project is supported by the NASA Graduate Student Researchers Program grant NGT-50290 (N.M.S.).

  11. [Presbiphonia. Age-related changes in the acoustic voice characteristics].

    PubMed

    Shilenkova, V V; Bestolkova, O S

    2013-01-01

    The objective of the present study was the comparative analysis of acoustic parameters of the voice in the subjects of different age groups. The phonetographic analysis involved 85 relatively healthy subjects (40 men and 45 women) divided into two age-matched groups. Group 1 included mature adults at the age of 43-59 years (n=43), group 2 was comprised of the aged and elderly persons (60-85 years, n=42). It was shown that the frequency of the primary tone decreases with age not only in women but also in men even though the decrease is less pronounced in the latter group. The process of ageing is accompanied by the narrowing of the frequency and dynamic range of the voice, the increase of Jitter, and the decrease in the strength of the voice. As a result, the dyshonia severity index (DSI) shifts toward negative values. These changes are more pronounced in women compared with men. Age-specific negative dynamics of maximum phonation time was not documented.

  12. The Age Related Properties of Solar Type Stars

    NASA Technical Reports Server (NTRS)

    Soderblom, David

    1999-01-01

    The studies of lithium in solar-type stars in clusters of a wide range of ages has provided critical information on a tracer of convective processes, especially among very young stars. Our most recent work has been on a pre-main sequence cluster (NGC 2264) that took place after this grant expired, but was founded on it. The spread seen in Li in Zero-Age Main Sequence clusters like the Pleiades is huge and possibly related to rotation. No clear spread in seen in NGC 2264, so it does not have its origins in the conditions of formation but is instead a result of processes occurring during PMS evolution. Our observations of M67 were particularly interesting because this cluster is the same age as the Sun, i.e.,very old. Clear evidence was seen for a spread in Li there too, indicating that the spread seen in very young stars perpetuates itself into old age.

  13. Hhip haploinsufficiency sensitizes mice to age-related emphysema.

    PubMed

    Lao, Taotao; Jiang, Zhiqiang; Yun, Jeong; Qiu, Weiliang; Guo, Feng; Huang, Chunfang; Mancini, John Dominic; Gupta, Kushagra; Laucho-Contreras, Maria E; Naing, Zun Zar Chi; Zhang, Li; Perrella, Mark A; Owen, Caroline A; Silverman, Edwin K; Zhou, Xiaobo

    2016-08-01

    Genetic variants in Hedgehog interacting protein (HHIP) have consistently been associated with the susceptibility to develop chronic obstructive pulmonary disease and pulmonary function levels, including the forced expiratory volume in 1 s (FEV1), in general population samples by genome-wide association studies. However, in vivo evidence connecting Hhip to age-related FEV1 decline and emphysema development is lacking. Herein, using Hhip heterozygous mice (Hhip(+/-)), we observed increased lung compliance and spontaneous emphysema in Hhip(+/-) mice starting at 10 mo of age. This increase was preceded by increases in oxidative stress levels in the lungs of Hhip(+/-) vs. Hhip(+/+) mice. To our knowledge, these results provide the first line of evidence that HHIP is involved in maintaining normal lung function and alveolar structures. Interestingly, antioxidant N-acetyl cysteine treatment in mice starting at age of 5 mo improved lung function and prevented emphysema development in Hhip(+/-) mice, suggesting that N-acetyl cysteine treatment limits the progression of age-related emphysema in Hhip(+/-) mice. Therefore, reduced lung function and age-related spontaneous emphysema development in Hhip(+/-) mice may be caused by increased oxidative stress levels in murine lungs as a result of haploinsufficiency of Hhip. PMID:27444019

  14. Degradation products from naturally aged paper leaves of a 16th-century-printed book: a spectrochemical study.

    PubMed

    Bronzato, Maddalena; Calvini, Paolo; Federici, Carlo; Bogialli, Sara; Favaro, Gabriella; Meneghetti, Moreno; Mba, Miriam; Brustolon, Marina; Zoleo, Alfonso

    2013-07-15

    In this work, we present a wide-range spectrochemical analysis of the degradation products from naturally aged paper. The samples obtained from wash waters used during the de-acidification treatment of leaves from a 16th-century-printed book were analysed through NMR, IR, Raman UV/Vis, EPR and X-ray fluorescence (XRF) spectroscopy and HPLC-MS and inductively coupled plasma (ICP) analysis. By these methods we also studied some of the previous samples treated by acidification (sample AP) and catalytic hydrogenation (sample HP). Crossing all the data, we obtained precise indications about the main functional groups occurring on the degraded, water-soluble cellulose oligomers. These results point out that the chromophores responsible for browning are conjugated carbonyl and carboxyl compounds. As a whole, we show that the analysis of wash waters, used in the usual conservation treatments of paper de-acidification, gives much valuable information about both the conservation state of the book and the degradation reactions occurring on the leaves, due to the huge amount of cellulose by-products contained in the samples. We propose therefore this procedure as a new very convenient general method to obtain precious and normally unavailable information on the cellulose degradation by-products from naturally aged paper. PMID:23733361

  15. Aging-associated formaldehyde-induced norepinephrine deficiency contributes to age-related memory decline.

    PubMed

    Mei, Yufei; Jiang, Chun; Wan, You; Lv, Jihui; Jia, Jianping; Wang, Xiaomin; Yang, Xu; Tong, Zhiqian

    2015-08-01

    A norepinephrine (NE) deficiency has been observed in aged rats and in patients with Alzheimer's disease and is thought to cause cognitive disorder. Which endogenous factor induces NE depletion, however, is largely unknown. In this study, we investigated the effects of aging-associated formaldehyde (FA) on the inactivation of NE in vitro and in vivo, and on memory behaviors in rodents. The results showed that age-related DNA demethylation led to hippocampal FA accumulation, and when this occurred, the hippocampal NE content was reduced in healthy male rats of different ages. Furthermore, biochemical analysis revealed that FA rapidly inactivated NE in vitro and that an intrahippocampal injection of FA markedly reduced hippocampal NE levels in healthy adult rats. Unexpectedly, an injection of FA (at a pathological level) or 6-hydroxydopamine (6-OHDA, a NE depletor) can mimic age-related NE deficiency, long-term potentiation (LTP) impairments, and spatial memory deficits in healthy adult rats. Conversely, an injection of NE reversed age-related deficits in both LTP and memory in aged rats. In agreement with the above results, the senescence-accelerated prone 8 (SAMP8) mice also exhibited a severe deficit in LTP and memory associated with a more severe NE deficiency and FA accumulation, when compared with the age-matched, senescence-resistant 1 (SAMR1) mice. Injection of resveratrol (a natural FA scavenger) or NE into SAMP8 mice reversed FA accumulation and NE deficiency and restored the magnitude of LTP and memory. Collectively, these findings suggest that accumulated FA is a critical endogenous factor for aging-associated NE depletion and cognitive decline.

  16. Trajectories of depressive symptoms in old age: Integrating age-, pathology-, and mortality-related changes.

    PubMed

    Chui, Helena; Gerstorf, Denis; Hoppmann, Christiane A; Luszcz, Mary A

    2015-12-01

    Late life involves a variety of different challenges to well-being. This study extends and qualifies propositions drawn from the paradox of well-being in aging using 15-year longitudinal data on depressive symptoms from old and very old participants in the Australian Longitudinal Study of Ageing (Baseline N = 2,087; Mage = 78.69 years; range: 65-103 years; 49.40% women). We first examined age-related trajectories in depressive symptoms from young-old to oldest-old, taking into account (changes in) relevant correlates, pathology, and mortality; and, second, we investigated gender differences in these trajectories. Results revealed that age-related trajectories of depressive symptoms were predictive of mortality hazards. The unique predictive effects of both level of, and change in, depressive symptoms were independent of one another and held after taking into account education as well as changes in marital status, living arrangements, cognitive function, and illness burden. In addition, results indicated that depressive symptoms were elevated among participants suffering from arthritis, and increased with age more markedly in men than in women. In particular, the significant Age × Gender interaction indicated that the gender gap in depressive symptoms reduced from young-old to old-old and reversed in very old age when men showed more depressive symptoms than women. Qualifying the paradox of well-being in aging, findings demonstrated that depressive symptoms increased from young-old to oldest-old and suggest that age-, pathology-, and mortality-related changes should be examined in concert to advance our understanding of individual differences in depressive symptom trajectories in late life.

  17. Age-related priming effects in social judgments.

    PubMed

    Hess, T M; McGee, K A; Woodburn, S M; Bolstad, C A

    1998-03-01

    Two experiments investigated adult age differences in the impact of previously activated (and thus easily accessible) trait-related information on judgments about people. The authors hypothesized that age-related declines in the efficiency of controlled processing mechanisms during adulthood would be associated with increased susceptibility to judgment biases associated with such information. In each study, different-aged adults made impression judgments about a target, and assimilation of these judgments to trait constructs activated in a previous, unrelated task were examined. Consistent with the authors' hypotheses, older adults were likely to form impressions that were biased toward the primed trait constructs. In contrast, younger adults exhibited greater awareness of the primed information and were more likely to correct for its perceived influence, especially when distinctive contextual cues regarding the source of the primes were available. PMID:9533195

  18. The relative impact of age and attractiveness stereotypes on persuasion.

    PubMed

    Puckett, J M; Petty, R E; Cacioppo, J T; Fischer, D L

    1983-05-01

    The relative impact of the old-age and attractiveness stereotypes on persuasion was investigated. College students read essays that contained either cogent or specious arguments that were attributed either to young or old, socially attractive or unattractive authors. Evaluations of the essay itself were affected only by the quality of the arguments presented. Argument quality and attractiveness interacted to determine perceptions of the author and opinions on the position advocated in the essay: attractive authors were rated higher and were more persuasive than unattractive authors when the essay was strong, but were derogated and unpersuasive relative to unattractive authors when the essay was weak. Age of the author had an impact only on a few of the author-evaluation scales. A hierarchy of stereotype potency in which social attractiveness is prepotent over age is offered tentatively.

  19. Age-related macular degeneration: Evidence of a major gene

    SciTech Connect

    Bhatt, S.; Warren, C.; Yang, H.

    1994-09-01

    Age-related macular degeneration is a major cause of blindness in developing countries. It remains a very poorly understood disorder. Although environmental and genetic factors have been implicated in its pathogenesis, none have been firmly implicated. The purpose of this study was to use pedigree analysis to evaluate the possible role of a major gene as a determinant of familial aggregation. Information was collected regarding occupation, smoking, sun exposure, associated medical problems and family history. 50 probands with age-related macular degeneration (ARMD) and 39 age, race and sex-matched controls were included in the study. In the ARMD group 15/50 (30%) of probands reported a positive family history; 22 out of 222 first degree relatives over age 60 were reported to be affected. In the control groups, none of the 138 first degree relatives over age 50 had a history of ARMD. This difference is statistically significant (p = 0.0003), indicating that genetic factors may play an important role in the pathogenesis of ARMD. In the ARMD group more siblings as compared to parents (16/127 vs. 5/82) were affected. 5/50 (10%) of the ARMD probands also gave a history of a second degree relative affected with ARMD, compared to none known among the relatives of controls. Data from 50 pedigrees were analyzed by complex segregation analysis under a class A regressive logistic model using the REGD program implemented in the SAGE package. Preliminary results allow rejection of a polygenic model and suggest there is a major gene for ARMD in these families. The inheritance model most compatible with the observed familial aggregation is autosomal recessive. In conclusion, these results are suggestive of a major gene effect in the etiology of ARMD. Identification of a major gene effect is a first step to further pursue linkage analysis and to search for the gene(s) involved in the causation of ARMD.

  20. Nutritional antioxidants and age-related cataract and maculopathy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that...

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

    PubMed

    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.

  2. Age-Related Factors in Second Language Acquisition.

    ERIC Educational Resources Information Center

    Twyford, Charles William

    The convergence of several lines of psycholinguistic and sociolinguistic research suggests possible explanations for age-related influences on language acquisition. These factors, which include cognitive development, sociocultural context, affective factors, and language input, can be helpful to language educators. By being alert to the cognitive…

  3. Relations among Socioeconomic Status, Age, and Predictors of Phonological Awareness

    ERIC Educational Resources Information Center

    McDowell, Kimberly D.; Lonigan, Christopher J.; Goldstein, Howard

    2007-01-01

    Purpose: This study simultaneously examined predictors of phonological awareness within the framework of 2 theories: the phonological distinctness hypothesis and the lexical restructuring model. Additionally, age as a moderator of the relations between predictor variables and phonological awareness was examined. Method: This cross-sectional…

  4. The Experience of Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Wong, Elaine Y. H.; Guymer, Robyn H.; Hassell, Jennifer B.; Keeffe, Jill E.

    2004-01-01

    This qualitative article describes the impact of age-related macular degeneration (ARMD) among 15 participants: how a person makes sense of ARMD, the effect of ARMD on the person's quality of life, the psychological disturbances associated with the limitations of ARMD, and the influence of ARMD on social interactions. Such in-depth appreciation of…

  5. The Relative Age Effect in Elite Sport: The French Case

    ERIC Educational Resources Information Center

    Delorme, Nicolas; Boiche, Julie; Raspaud, Michel

    2009-01-01

    The relative age effect (RAE) is considered a common phenomenon in elite sport. However, it has not been examined systematically in previous research, and the mechanisms likely to generate or to limit such an effect are little understood. This paper investigates the prevalence of the RAE in French professional championship-level players, taking…

  6. Related Services for School-Aged Children with Disabilities.

    ERIC Educational Resources Information Center

    Smith-Davis, Judy; Littlejohn, William R.

    1991-01-01

    This theme issue provides an overview of related services for school aged children with disabilities as required by federal law, especially the Individuals with Disabilities Education Act and Section 504 of the Rehabilitation Act of 1973. It identifies the personnel associated with delivering various services including audiology, occupational…

  7. Age-Related Health Stereotypes and Illusory Correlation

    ERIC Educational Resources Information Center

    Madey, Scott F.; Chasteen, Alison L.

    2004-01-01

    This experiment investigated how age-related health stereotypes affect people's judgments of younger and older patients' medical compliance. Previous research has shown that stereotypes of young adults include healthy components, but stereotypes of older adults include both healthy and unhealthy components (Hummert, 1990). We predicted that…

  8. The Relative Impact of Age and Attractiveness Stereotypes on Persuasion.

    ERIC Educational Resources Information Center

    Puckett, James M.; And Others

    1983-01-01

    Investigated the impact of old-age and attractiveness stereotypes on persuasion. College students (N=220) read essays attributed to young or old authors. Attractive authors were rated higher and were more persuasive relative to unattractive authors when the essay was weak. (Author/JAC)

  9. Soybean β-Conglycinin Prevents Age-Related Hearing Impairment.

    PubMed

    Tanigawa, Tohru; Shibata, Rei; Kondo, Kazuhisa; Katahira, Nobuyuki; Kambara, Takahiro; Inoue, Yoko; Nonoyama, Hiroshi; Horibe, Yuichiro; Ueda, Hiromi; Murohara, Toyoaki

    2015-01-01

    Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress.

  10. Evaluation of Ultrasonic and Thermal Nondestructive Evaluation for the Characterization of Aging Degradation in Braided Composite Materials

    NASA Technical Reports Server (NTRS)

    Martin, Richard E.

    2010-01-01

    This paper examines the ability of traditional nondestructive evaluation (NDE) techniques to measure the degradation of braided polymer composite materials subjected to thermal-humidity cycling to simulate aging. A series of braided composite coupons were examined using immersion ultrasonic and pulsed thermography techniques in the as received condition. These same specimens were then examined following extended thermal-humidity cycling. Results of this examination did not show a significant change in the resulting (NDE) signals.

  11. Brain site-specific proteome changes in aging-related dementia

    PubMed Central

    Manavalan, Arulmani; Mishra, Manisha; Feng, Lin; Sze, Siu Kwan; Akatsu, Hiroyasu; Heese, Klaus

    2013-01-01

    This study is aimed at gaining insights into the brain site-specific proteomic senescence signature while comparing physiologically aged brains with aging-related dementia brains (for example, Alzheimer's disease (AD)). Our study of proteomic differences within the hippocampus (Hp), parietal cortex (pCx) and cerebellum (Cb) could provide conceptual insights into the molecular mechanisms involved in aging-related neurodegeneration. Using an isobaric tag for relative and absolute quantitation (iTRAQ)-based two-dimensional liquid chromatography coupled with tandem mass spectrometry (2D-LC-MS/MS) brain site-specific proteomic strategy, we identified 950 proteins in the Hp, pCx and Cb of AD brains. Of these proteins, 31 were significantly altered. Most of the differentially regulated proteins are involved in molecular transport, nervous system development, synaptic plasticity and apoptosis. Particularly, proteins such as Gelsolin (GSN), Tenascin-R (TNR) and AHNAK could potentially act as novel biomarkers of aging-related neurodegeneration. Importantly, our Ingenuity Pathway Analysis (IPA)-based network analysis further revealed ubiquitin C (UBC) as a pivotal protein to interact with diverse AD-associated pathophysiological molecular factors and suggests the reduced ubiquitin proteasome degradation system (UPS) as one of the causative factors of AD. PMID:24008896

  12. A Nanoindentation Study on Grain-Boundary Contributions to Strengthening and Aging Degradation Mechanisms in Advanced 12Cr Ferritic Steel

    SciTech Connect

    Jang, Jae-il; Shim, Sang Hoon; Komazaki, Shin-ichi; Honda, Tetsuya

    2007-01-01

    Nanoindentation experiments and microstructural analysis were performed on advanced 12% Cr ferritic steel having extremely fine and complex martensitic microstructures, to answer unsolved questions on the contributions of grain boundaries to strengthening and aging degradation mechanisms in both as-tempered and thermally aged steels. Interesting features of the experimental results led us to suggest that among several high angle boundaries, block boundary is most effective in enhancing the macroscopic strength in as-tempered virgin sample, and that a decrease in matrix strength rather than reduction in grain-boundary strengthening effect is primarily responsible for the macroscopic softening behavior observed during thermal exposure.

  13. Short-Term Rhizosphere Effect on Available Carbon Sources, Phenanthrene Degradation, and Active Microbiome in an Aged-Contaminated Industrial Soil

    PubMed Central

    Thomas, François; Cébron, Aurélie

    2016-01-01

    Over the last decades, understanding of the effects of plants on soil microbiomes has greatly advanced. However, knowledge on the assembly of rhizospheric communities in aged-contaminated industrial soils is still limited, especially with regard to transcriptionally active microbiomes and their link to the quality or quantity of carbon sources. We compared the short-term (2–10 days) dynamics of bacterial communities and potential PAH-degrading bacteria in bare or ryegrass-planted aged-contaminated soil spiked with phenanthrene, put in relation with dissolved organic carbon (DOC) sources and polycyclic aromatic hydrocarbon (PAH) pollution. Both resident and active bacterial communities (analyzed from DNA and RNA, respectively) showed higher species richness and smaller dispersion between replicates in planted soils. Root development strongly favored the activity of Pseudomonadales within the first 2 days, and of members of Actinobacteria, Caulobacterales, Rhizobiales, and Xanthomonadales within 6–10 days. Plants slowed down the dissipation of phenanthrene, while root exudation provided a cocktail of labile substrates that might preferentially fuel microbial growth. Although the abundance of PAH-degrading genes increased in planted soil, their transcription level stayed similar to bare soil. In addition, network analysis revealed that plants induced an early shift in the identity of potential phenanthrene degraders, which might influence PAH dissipation on the long-term. PMID:26903971

  14. Examining Relative Age Effects in Fundamental Skill Proficiency in British Children Aged 6-11 Years.

    PubMed

    Birch, Samantha; Cummings, Laura; Oxford, Samuel W; Duncan, Michael J

    2016-10-01

    Birch, S, Cummings, L, Oxford, SW, and Duncan, MJ. Examining relative age effects in fundamental skill proficiency in British children aged 6-11 years. J Strength Cond Res 30(10): 2809-2815, 2016-The relative age effect (RAE) suggests that there is a clustering of birth dates just after the cutoff used for sports selection in age-grouped sports and that in such circumstances, relatively older sportspeople may enjoy maturational and physical advantages over their younger peers. Few studies have examined this issue in nonselective groups of children, and none have examined whether there is evidence of any RAE in skill performance. The aim of this study was to assess whether there were differences in fundamental movement skill (FMS) proficiency within children placed in age groups according to the school year. Six FMS (sprint, side gallop, balance, jump, catch, and throw) were assessed in 539 school children (258 boys and 281 girls) aged 6-11 years (mean age ± SD = 7.7 ± 1.7 years). We examined differences in these FMS between gender groups and children born in different quarters of the year after controlling for age and body mass index (BMI). For balance, chronological age was significant as a covariate (p = 0.0001) with increases in age associated with increases in balance. Boys had significantly higher sprint mastery compared with girls (p = 0.012), and increased BMI was associated with poorer sprint mastery (p = 0.001). Boys had higher catching mastery than girls (p = 0.003), and children born in Q1 had significantly greater catching mastery than those born in Q2 (p = 0.015), Q3 (p = 0.019), and Q4 (p = 0.01). Results for throwing mastery also indicated higher mastery in boys compared with girls (p = 0.013) and that children born in Q1 had higher throwing proficiency than those born in Q4 (p = 0.038). These results are important if coaches are basing sport selection on measures of skilled performance, particularly in object-control skills. Categorizing children

  15. Prevalence of age-related macular degeneration among the elderly

    PubMed Central

    Rasoulinejad, Seyed Ahmad; Zarghami, Amin; Hosseini, Seyed Reza; Rajaee, Neda; Rasoulinejad, Seyed Elahe; Mikaniki, Ebrahim

    2015-01-01

    Background: Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in elderly population in the developing countries. Previous epidemiological studies revealed various potential modifiable risk factors for this disease. The purpose of this study was to evaluate the prevalence of AMD among elderly living in Babol, North of Iran. Methods: The study population of this cross-sectional study came from the Amirkola Health and Ageing Project (AHAP), the first comprehensive cohort study of the health of people aged 60 years and over in Amirkola, North of Iran. The prevalence of AMD was estimated and its risk was determined using logistic regression analysis (LRA) with regard to variables such as smoking, hyperlipidemia, hypertension and diabetes. Results: Five hundred and five participants with mean age of 71.55±5.9 (ranged 60-89) years entered the study. The prevalence of AMD was 17.6%. There was a significant association between AMD and smoking (P<0.001) but no association was seen with AMD and age, level of education, history of hyperlipidemia, hypertension and diabetes. Multiple LRAs revealed that smoking increased AMD by odds ratio of 5.03 (95% confidence interval 2.47-10.23 p<0.001) as compared to nonsmokers Conclusion: According to our findings, the prevalence of AMD was relatively high and smoking increased the risk of AMD in the elderly population. PMID:26644880

  16. Age-related impairment of mesenchymal progenitor cell function.

    PubMed

    Stolzing, Alexandra; Scutt, Andrew

    2006-06-01

    In most mesenchymal tissues a subcompartment of multipotent progenitor cells is responsible for the maintenance and repair of the tissue following trauma. With increasing age, the ability of tissues to repair themselves is diminished, which may be due to reduced functional capacity of the progenitor cells. The purpose of this study was to investigate the effect of aging on rat mesenchymal progenitor cells. Mesenchymal progenitor cells were isolated from Wistar rats aged 3, 7, 12 and 56 weeks. Viability, capacity for differentiation and cellular aging were examined. Cells from the oldest group accumulated raised levels of oxidized proteins and lipids and showed decreased levels of antioxidative enzyme activity. This was reflected in decreased fibroblast colony-forming unit (CFU-f) numbers, increased levels of apoptosis and reduced proliferation and potential for differentiation. These data suggest that the reduced ability to maintain mesenchymal tissue homeostasis in aged mammals is not purely due to a decline in progenitor cells numbers but also to a loss of progenitor functionality due to the accumulation of oxidative damage, which may in turn be a causative factor in a number of age-related pathologies such as arthritis, tendinosis and osteoporosis.

  17. Age and gender related differences in aortic blood flow

    NASA Astrophysics Data System (ADS)

    Enevoldsen, Marie Sand; Pedersen, Mads Møller; Hemmsen, Martin Christian; Lönn, Lars; Henneberg, Kaj-Åge; Jensen, Jørgen Arendt

    2012-03-01

    The abdominal aorta (AA) is predisposed to development of abdominal aneurysms (AAA), a focal dilatation with fatal consequences if left untreated. The blood flow patterns is thought to play an important role in the development of AAA. The purpose of this work is to investigate the blood flow patterns within a group of healthy volunteers (six females, eight 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 data were acquired using the research interface on a Profocus ultrasound scanner (B-K Medical, Herlev, Denmark; segmentation of 3D magnetic resonance angiography (Magnetom Trio, Siemens Healthcare, Erlangen, Germany). The largest average diameter was among the elderly males (19.7 (+/- 1.33) mm) and smallest among the young females (12.4 (+/- 0.605) mm). The highest peak systolic velocity was in the young female group (1.02 (+/- 0.336) m/s) and lowest in the elderly male group (0.836 (+/- 0.127) m/s). A geometrical change with age was observed as the AA becomes more bended with age. This also affects the blood flow velocity patterns, which are markedly different from young to elderly. Thus, changes in blood flow patterns in the AA related to age and gender are observed. Further investigations are needed to determine the relation between changes in blood flow patterns and AAA development.

  18. Relational learning and transitive expression in aging and amnesia

    PubMed Central

    D'Angelo, Maria C.; Kamino, Daphne; Ostreicher, Melanie; Moses, Sandra N.; Rosenbaum, R. Shayna

    2016-01-01

    ABSTRACT Aging has been associated with a decline in relational memory, which is critically supported by the hippocampus. By adapting the transitivity paradigm (Bunsey and Eichenbaum (1996) Nature 379:255‐257), which traditionally has been used in nonhuman animal research, this work examined the extent to which aging is accompanied by deficits in relational learning and flexible expression of relational information. Older adults' performance was additionally contrasted with that of amnesic case DA to understand the critical contributions of the medial temporal lobe, and specifically, the hippocampus, which endures structural and functional changes in healthy aging. Participants were required to select the correct choice item (B versus Y) based on the presented sample item (e.g., A). Pairwise relations must be learned (A‐>B, B‐>C, C‐>D) so that ultimately, the correct relations can be inferred when presented with a novel probe item (A‐>C?Z?). Participants completed four conditions of transitivity that varied in terms of the degree to which the stimuli and the relations among them were known pre‐experimentally. Younger adults, older adults, and DA performed similarly when the condition employed all pre‐experimentally known, semantic, relations. Older adults and DA were less accurate than younger adults when all to‐be‐learned relations were arbitrary. However, accuracy improved for older adults when they could use pre‐experimentally known pairwise relations to express understanding of arbitrary relations as indexed through inference judgments. DA could not learn arbitrary relations nor use existing knowledge to support novel inferences. These results suggest that while aging has often been associated with an emerging decline in hippocampal function, prior knowledge can be used to support novel inferences. However, in case DA, significant damage to the hippocampus likely impaired his ability to learn novel relations, while additional damage to

  19. Dynamics of biomarkers in relation to aging and mortality.

    PubMed

    Arbeev, Konstantin G; Ukraintseva, Svetlana V; Yashin, Anatoliy I

    2016-06-01

    Contemporary longitudinal studies collect repeated measurements of biomarkers allowing one to analyze their dynamics in relation to mortality, morbidity, or other health-related outcomes. Rich and diverse data collected in such studies provide opportunities to investigate how various socio-economic, demographic, behavioral and other variables can interact with biological and genetic factors to produce differential rates of aging in individuals. In this paper, we review some recent publications investigating dynamics of biomarkers in relation to mortality, which use single biomarkers as well as cumulative measures combining information from multiple biomarkers. We also discuss the analytical approach, the stochastic process models, which conceptualizes several aging-related mechanisms in the structure of the model and allows evaluating "hidden" characteristics of aging-related changes indirectly from available longitudinal data on biomarkers and follow-up on mortality or onset of diseases taking into account other relevant factors (both genetic and non-genetic). We also discuss an extension of the approach, which considers ranges of "optimal values" of biomarkers rather than a single optimal value as in the original model. We discuss practical applications of the approach to single biomarkers and cumulative measures highlighting that the potential of applications to cumulative measures is still largely underused. PMID:27138087

  20. PETN: Variation in Physical and Chemical Characteristics Related to Aging.

    SciTech Connect

    Monroe, D. C.; Laintz, K. E.; Kramer, J. F.; Peterson, P. D.

    2006-01-01

    Physical and chemical analyses of five PETN (pentaerythritol tetranitrate) batches have been conducted to assist in defining powder acceptance criteria for qualification of newly manufactured powders, as well as for examination of potential changes related to aging and thus changes in performance. Results showed that (1) repeatable Fisher Sub-Sieve Sizer measurements (which relate well to historic performance data) could be obtained with consistent sample setup and measurement techniques; (2) BET nitrogen adsorption estimates of surface area correlate well with Fisher measurements and appear less variable; (3) PharmaVision particle size analyses show promise in discriminating among PETN batches; and (4) SEMs are extremely useful in semi-quantitative discrimination among batches. Physical and chemical data will be related to performance data (to be obtained) to develop quantitative physical and chemical tests useful in predicting performance over time, i.e., as powders age.

  1. The aging correlation (RH + t): Relative humidity (%) + temperature (deg C)

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.

    1986-01-01

    An aging correlation between corrosion lifetime, and relative humidity RH (%) and temperature t (C) has been reported in the literature. This aging correlation is a semi-log plot of corrosion lifetime on the log scale versus the interesting summation term RH(%) + t(C) on the linear scale. This empirical correlation was derived from observation of experimental data trends and has been referred to as an experimental law. Using electrical resistivity data of polyvinyl butyral (PVB) measured as a function of relative humidity and temperature, it was found that the electrical resistivity could be expressed as a function of the term RH(%) t(C). Thus, if corrosion is related to leakage current through an organic insulator, which, in turn, is a function of RH and t, then some partial theoretical validity for the correlation is indicated. This article describes the derivation of the term RH(%) t(C) from PVB electrical resistivity data.

  2. Analysis of genomic regions of Trichoderma harzianum IOC-3844 related to biomass degradation.

    PubMed

    Crucello, Aline; Sforça, Danilo Augusto; Horta, Maria Augusta Crivelente; dos Santos, Clelton Aparecido; Viana, Américo José Carvalho; Beloti, Lilian Luzia; de Toledo, Marcelo Augusto Szymanski; Vincentz, Michel; Kuroshu, Reginaldo Massanobu; de Souza, Anete Pereira

    2015-01-01

    Trichoderma harzianum IOC-3844 secretes high levels of cellulolytic-active enzymes and is therefore a promising strain for use in biotechnological applications in second-generation bioethanol production. However, the T. harzianum biomass degradation mechanism has not been well explored at the genetic level. The present work investigates six genomic regions (~150 kbp each) in this fungus that are enriched with genes related to biomass conversion. A BAC library consisting of 5,760 clones was constructed, with an average insert length of 90 kbp. The assembled BAC sequences revealed 232 predicted genes, 31.5% of which were related to catabolic pathways, including those involved in biomass degradation. An expression profile analysis based on RNA-Seq data demonstrated that putative regulatory elements, such as membrane transport proteins and transcription factors, are located in the same genomic regions as genes related to carbohydrate metabolism and exhibit similar expression profiles. Thus, we demonstrate a rapid and efficient tool that focuses on specific genomic regions by combining a BAC library with transcriptomic data. This is the first BAC-based structural genomic study of the cellulolytic fungus T. harzianum, and its findings provide new perspectives regarding the use of this species in biomass degradation processes. PMID:25836973

  3. Analysis of Genomic Regions of Trichoderma harzianum IOC-3844 Related to Biomass Degradation

    PubMed Central

    Crucello, Aline; Sforça, Danilo Augusto; Horta, Maria Augusta Crivelente; dos Santos, Clelton Aparecido; Viana, Américo José Carvalho; Beloti, Lilian Luzia; de Toledo, Marcelo Augusto Szymanski; Vincentz, Michel; Kuroshu, Reginaldo Massanobu; de Souza, Anete Pereira

    2015-01-01

    Trichoderma harzianum IOC-3844 secretes high levels of cellulolytic-active enzymes and is therefore a promising strain for use in biotechnological applications in second-generation bioethanol production. However, the T. harzianum biomass degradation mechanism has not been well explored at the genetic level. The present work investigates six genomic regions (~150 kbp each) in this fungus that are enriched with genes related to biomass conversion. A BAC library consisting of 5,760 clones was constructed, with an average insert length of 90 kbp. The assembled BAC sequences revealed 232 predicted genes, 31.5% of which were related to catabolic pathways, including those involved in biomass degradation. An expression profile analysis based on RNA-Seq data demonstrated that putative regulatory elements, such as membrane transport proteins and transcription factors, are located in the same genomic regions as genes related to carbohydrate metabolism and exhibit similar expression profiles. Thus, we demonstrate a rapid and efficient tool that focuses on specific genomic regions by combining a BAC library with transcriptomic data. This is the first BAC-based structural genomic study of the cellulolytic fungus T. harzianum, and its findings provide new perspectives regarding the use of this species in biomass degradation processes. PMID:25836973

  4. Analysis of genomic regions of Trichoderma harzianum IOC-3844 related to biomass degradation.

    PubMed

    Crucello, Aline; Sforça, Danilo Augusto; Horta, Maria Augusta Crivelente; dos Santos, Clelton Aparecido; Viana, Américo José Carvalho; Beloti, Lilian Luzia; de Toledo, Marcelo Augusto Szymanski; Vincentz, Michel; Kuroshu, Reginaldo Massanobu; de Souza, Anete Pereira

    2015-01-01

    Trichoderma harzianum IOC-3844 secretes high levels of cellulolytic-active enzymes and is therefore a promising strain for use in biotechnological applications in second-generation bioethanol production. However, the T. harzianum biomass degradation mechanism has not been well explored at the genetic level. The present work investigates six genomic regions (~150 kbp each) in this fungus that are enriched with genes related to biomass conversion. A BAC library consisting of 5,760 clones was constructed, with an average insert length of 90 kbp. The assembled BAC sequences revealed 232 predicted genes, 31.5% of which were related to catabolic pathways, including those involved in biomass degradation. An expression profile analysis based on RNA-Seq data demonstrated that putative regulatory elements, such as membrane transport proteins and transcription factors, are located in the same genomic regions as genes related to carbohydrate metabolism and exhibit similar expression profiles. Thus, we demonstrate a rapid and efficient tool that focuses on specific genomic regions by combining a BAC library with transcriptomic data. This is the first BAC-based structural genomic study of the cellulolytic fungus T. harzianum, and its findings provide new perspectives regarding the use of this species in biomass degradation processes.

  5. Age related alterations of adrenoreceptor activity in erythrocyte membrane.

    PubMed

    Lomsadze, G; Khetsuriani, R; Arabuli, M; Intskirveli, N; Sanikidze, T

    2011-06-01

    The aim of the study was the investigation of age-related functional alterations of adrenoreceptors and the effect of agonist and antagonist drugs on age related adrenoreceptor activity in erythrocyte membrane. The impact of isopropanol and propanol on functional activity β- adrenergic receptors in red blood cell membrane were studied in 50 practically healthy men--volunteers. (I group--75-89 years old, II group--22-30 years old). The EPR signals S1 and S2 were registered in red blood cell membrane samples after incubation with isopropanol and propanol respectively. It was found that decreasing sensitivity (functional activity) of red blood cells membrane adrenoreceptors comes with aging (S1oldage-related hypertension, heart failure, type II diabetes and other diseases, The findings suggests that the erythrocyte could be a new therapeutic marker in the treatment different diseases.

  6. Adiponectin deficiency exacerbates age-related hearing impairment.

    PubMed

    Tanigawa, T; Shibata, R; Ouchi, N; Kondo, K; Ishii, M; Katahira, N; Kambara, T; Inoue, Y; Takahashi, R; Ikeda, N; Kihara, S; Ueda, H; Murohara, T

    2014-04-24

    Obesity-related disorders are closely associated with the development of age-related hearing impairment (ARHI). Adiponectin (APN) exerts protective effects against obesity-related conditions including endothelial dysfunction and atherosclerosis. Here, we investigated the impact of APN on ARHI. APN-knockout (APN-KO) mice developed exacerbation of hearing impairment, particularly in the high frequency range, compared with wild-type (WT) mice. Supplementation with APN prevented the hearing impairment in APN-KO mice. At 2 months of age, the cochlear blood flow and capillary density of the stria vascularis (SV) were significantly reduced in APN-KO mice as compared with WT mice. APN-KO mice also showed a significant increase in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells in the organ of Corti in the cochlea at 2 months of age. At the age of 6 months, hair cells were lost at the organ of Corti in APN-KO mice. In cultured auditory HEI-OC1 cells, APN reduced apoptotic activity under hypoxic conditions. Clinically, plasma APN levels were significantly lower in humans with ARHI. Multiple logistic regression analysis identified APN as a significant and independent predictor of ARHI. Our observations indicate that APN has an important role in preventing ARHI.

  7. [Glaucoma and age-related macular degeneration intricacy].

    PubMed

    Valtot, F

    2008-07-01

    Age-related macular degeneration (AMD) is the leading cause of legal blindness among the elderly in Western nations. Age is also a well-known and well-evidenced risk factor for glaucoma. With increasing longevity and the rising prevalence of older people around the world, more and more patients will have glaucoma and AMD. Clinical evaluation of these patients still poses problems for clinicians. It is very important to order the right tests at the right time to distinguish glaucomatous defects from those caused by retinal lesions, because appropriate therapy has a beneficial effect on slowing or halting damage. PMID:18957915

  8. Age-related lesions in the cerebrum in middle-aged female cynomolgus monkeys.

    PubMed

    Kodama, Rinya; Yang, Xiuying; Saski, Yuji; Iwashige, Shuichiro; Tanigawa, Yohei; Yoshikawa, Tsuyoshi; Nagaoka, Takaharu; Kamimura, Yasuhiro; Maeda, Horishi

    2010-02-01

    Alzheimer's disease (AD) in humans is a progressive neurogenic disease that can be linked with such characteristic pathological findings in the cerebrum as senile plaques (SPs), neurofibrillary tangles (NFTs), cerebral amyloid angiopathy (CAA), and neuronal loss. In the present study, the authors investigated the age-related morphological changes in 12 middle-aged and 12 young cynomolgus monkeys. Low numbers of neurons and astrocytes in the hippocampal region in cynomolgus monkeys accompanied ageing, and there was a high number of microglial cells; however, no clearly neurotoxic abnormalities due to beta-amyloid were noted before the age of 20 years. The onset of SPs and CAA in the cerebrum in cynomolgus monkeys can occur before the age of 20 years. SPs were almost all categorized as diffuse plaques (DPs); they did not have amyloid cores and were unaccompanied by neuritic degeneration. In cynomolgus monkeys, SPs (DPs) occur before the appearance of CAA. From the above, it was concluded that cynomolgus monkeys showed pathological changes due to ageing similar to those related to Alzheimer's disease in humans, even before they were 20 years old.

  9. Innate immunity and inflammation in ageing: a key for understanding age-related diseases

    PubMed Central

    Licastro, Federico; Candore, Giuseppina; Lio, Domenico; Porcellini, Elisa; Colonna-Romano, Giuseppina; Franceschi, Claudio; Caruso, Calogero

    2005-01-01

    The process of maintaining life for the individual is a constant struggle to preserve his/her integrity. This can come at a price when immunity is involved, namely systemic inflammation. Inflammation is not per se a negative phenomenon: it is the response of the immune system to the invasion of viruses or bacteria and other pathogens. During evolution the human organism was set to live 40 or 50 years; today, however, the immune system must remain active for much a longer time. This very long activity leads to a chronic inflammation that slowly but inexorably damages one or several organs: this is a typical phenomenon linked to ageing and it is considered the major risk factor for age-related chronic diseases. Alzheimer's disease, atherosclerosis, diabetes and even sarcopenia and cancer, just to mention a few – have an important inflammatory component, though disease progression seems also dependent on the genetic background of individuals. Emerging evidence suggests that pro-inflammatory genotypes are related to unsuccessful ageing, and, reciprocally, controlling inflammatory status may allow a better chance of successful ageing. In other words, age-related diseases are "the price we pay" for a life-long active immune system: this system has also the potential to harm us later, as its fine tuning becomes compromised. Our immune system has evolved to control pathogens, so pro-inflammatory responses are likely to be evolutionarily programmed to resist fatal infections with pathogens aggressively. Thus, inflammatory genotypes are an important and necessary part of the normal host responses to pathogens in early life, but the overproduction of inflammatory molecules might also cause immune-related inflammatory diseases and eventually death later. Therefore, low responder genotypes involved in regulation of innate defence mechanisms, might better control inflammatory responses and age-related disease development, resulting in an increased chance of long life survival

  10. Age-related decline in global form suppression.

    PubMed

    Wiegand, Iris; Finke, Kathrin; Töllner, Thomas; Starman, Kornelija; Müller, Hermann J; Conci, Markus

    2015-12-01

    Visual selection of illusory 'Kanizsa' figures, an assembly of local elements that induce the percept of a whole object, is facilitated relative to configurations composed of the same local elements that do not induce a global form--an instance of 'global precedence' in visual processing. 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-local task requiring selection of either a 'global' Kanizsa- or a 'local' non-Kanizsa configuration (in the presence of the respectively other configuration) by analyzing event-related lateralizations (ERLs). Behaviorally, older participants showed a more pronounced global-precedence effect. Electrophysiologically, this effect was accompanied by an early (150-225 ms) 'positivity posterior contralateral' (PPC), which was elicited for older, but not younger, participants, when the target was a non-Kanizsa configuration and the Kanizsa figure a distractor (rather than vice versa). In addition, timing differences in the subsequent (250-500 ms) posterior contralateral negativity (PCN) indicated that attentional resources were allocated faster to Kanizsa, as compared to non-Kanizsa, 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 and switching to the required local state of attentional resolution. PMID:26498865

  11. Aging Chart: a community resource for rapid exploratory pathway analysis of age-related processes.

    PubMed

    Moskalev, Alexey; Zhikrivetskaya, Svetlana; Shaposhnikov, Mikhail; Dobrovolskaya, Evgenia; Gurinovich, Roman; Kuryan, Oleg; Pashuk, Aleksandr; Jellen, Leslie C; Aliper, Alex; Peregudov, Alex; Zhavoronkov, Alex

    2016-01-01

    Aging research is a multi-disciplinary field encompassing knowledge from many areas of basic, applied and clinical research. Age-related processes occur on molecular, cellular, tissue, organ, system, organismal and even psychological levels, trigger the onset of multiple debilitating diseases and lead to a loss of function, and there is a need for a unified knowledge repository designed to track, analyze and visualize the cause and effect relationships and interactions between the many elements and processes on all levels. Aging Chart (http://agingchart.org/) is a new, community-curated collection of aging pathways and knowledge that provides a platform for rapid exploratory analysis. Building on an initial content base constructed by a team of experts from peer-reviewed literature, users can integrate new data into biological pathway diagrams for a visible, intuitive, top-down framework of aging processes that fosters knowledge-building and collaboration. As the body of knowledge in aging research is rapidly increasing, an open visual encyclopedia of aging processes will be useful to both the new entrants and experts in the field. PMID:26602690

  12. Aging Chart: a community resource for rapid exploratory pathway analysis of age-related processes.

    PubMed

    Moskalev, Alexey; Zhikrivetskaya, Svetlana; Shaposhnikov, Mikhail; Dobrovolskaya, Evgenia; Gurinovich, Roman; Kuryan, Oleg; Pashuk, Aleksandr; Jellen, Leslie C; Aliper, Alex; Peregudov, Alex; Zhavoronkov, Alex

    2016-01-01

    Aging research is a multi-disciplinary field encompassing knowledge from many areas of basic, applied and clinical research. Age-related processes occur on molecular, cellular, tissue, organ, system, organismal and even psychological levels, trigger the onset of multiple debilitating diseases and lead to a loss of function, and there is a need for a unified knowledge repository designed to track, analyze and visualize the cause and effect relationships and interactions between the many elements and processes on all levels. Aging Chart (http://agingchart.org/) is a new, community-curated collection of aging pathways and knowledge that provides a platform for rapid exploratory analysis. Building on an initial content base constructed by a team of experts from peer-reviewed literature, users can integrate new data into biological pathway diagrams for a visible, intuitive, top-down framework of aging processes that fosters knowledge-building and collaboration. As the body of knowledge in aging research is rapidly increasing, an open visual encyclopedia of aging processes will be useful to both the new entrants and experts in the field.

  13. Aging Chart: a community resource for rapid exploratory pathway analysis of age-related processes

    PubMed Central

    Moskalev, Alexey; Zhikrivetskaya, Svetlana; Shaposhnikov, Mikhail; Dobrovolskaya, Evgenia; Gurinovich, Roman; Kuryan, Oleg; Pashuk, Aleksandr; Jellen, Leslie C.; Aliper, Alex; Peregudov, Alex; Zhavoronkov, Alex

    2016-01-01

    Aging research is a multi-disciplinary field encompassing knowledge from many areas of basic, applied and clinical research. Age-related processes occur on molecular, cellular, tissue, organ, system, organismal and even psychological levels, trigger the onset of multiple debilitating diseases and lead to a loss of function, and there is a need for a unified knowledge repository designed to track, analyze and visualize the cause and effect relationships and interactions between the many elements and processes on all levels. Aging Chart (http://agingchart.org/) is a new, community-curated collection of aging pathways and knowledge that provides a platform for rapid exploratory analysis. Building on an initial content base constructed by a team of experts from peer-reviewed literature, users can integrate new data into biological pathway diagrams for a visible, intuitive, top-down framework of aging processes that fosters knowledge-building and collaboration. As the body of knowledge in aging research is rapidly increasing, an open visual encyclopedia of aging processes will be useful to both the new entrants and experts in the field. PMID:26602690

  14. Age-related cognitive decline during normal aging: the complex effect of education.

    PubMed

    Ardila, A; Ostrosky-Solis, F; Rosselli, M; Gómez, C

    2000-08-01

    The purpose of this study was to further analyze the effects of education on cognitive decline during normal aging. An 806-subject sample was taken from five different Mexican regions. Participants ranged in age from 16 to 85 years. Subjects were grouped into four educational levels: illiterate, 1-4, 5-9, and 10 or more years of education, and four age ranges: 16-30, 31-50, 51-65, and 66-85 years. A brief neuropsychological test battery (NEUROPSI), standardized and normalized in Spanish, was administered. The NEUROPSI test battery includes assessment of orientation, attention, memory, language, visuoperceptual abilities, motor skills, and executive functions. In general, test scores were strongly associated with level of educational, and differences among age groups were smaller than differences among education groups. However, there was an interaction between age and education such as that among illiterate individuals scores of participants 31-50 years old were higher than scores of participants 16-30 years old for over 50% of the tests. Different patterns of interaction among educational groups were distinguished. It was concluded that: (a) The course of life-span changes in cognition are affected by education. Among individuals with a low level of education, best neuropsychological test performance is observed at an older age than among higher-educated subjects; and (b) there is not a single relationship between age-related cognitive decline and education, but different patterns may be found, depending upon the specific cognitive domain. PMID:14590204

  15. The role of glucocorticoids in aging and age-related pharmacotherapy.

    PubMed

    Goudochnikov, V I

    2011-01-01

    Recently we have evaluated the role of glucocorticoids (GC) and other stress hormones in the pathogeny of age-related diseases. In order to perform this evaluation, we considered the DOHaD paradigm discussing long-term effects of adverse perinatal factors. In the present work, a part of the data collected previously was used for analyzing the role of GC in aging, as well as in age-related pharmacotherapy. The data were gathered in various databases, preferably in English, during the last 25-30 years. Although some authors suggest that GC can be considered as hormones of aging, the majority of investigators are quite careful in this respect. Nevertheless, it appears that the role of GC in various stages of ontogeny and transitions between them is well established. Besides, there are a lot of data that confirm a contribution of GC to the phenomena of perinatal programming/imprinting of adult diseases. What for the relationship between GC and aging, some studies confirm its existence, at least partially. Having analyzed the dynamics of morbidity and mortality of age-related diseases, we concluded on the absence of evidence in favor of unique general scheme of aging, where GC could play a role. However, in a rather paradoxal mode it was demonstrated that GC participate, at least indirectly, in the mechanisms of action of various drugs used for the treatment of cardiometabolic disorders (beta-blockers, angiotensin antagonists, some oral hypoglycemic agents) and neuropsychiatric diseases (antidepressants, antipsychotic agents, benzodiazepines and some anticonvulsive medicines), as well as in the effects of toxic agents (for example, drugs of abuse, including caffeine). Using the concept of hormesis, we discuss a reason for frequent utilization of these drugs, and not GC or their antagonists, in age-related pharmacotherapy. The caution is suggested in considering the essential function of GC in aging. Nevertheless, due to existence of theory that connects GC with aging

  16. Latent Fingermark Aging Patterns (Part I): Minutiae Count as One Indicator of Degradation.

    PubMed

    De Alcaraz-Fossoul, Josep; Mestres Patris, Cristina; Barrot Feixat, Carme; McGarr, Luke; Brandelli, Donna; Stow, Karen; Gené Badia, Manel

    2016-03-01

    The authors are exploring degradation patterns of latent fingermarks over time which can be quantitatively determined in a predictable manner by visual means. Several physical degradation parameters for assessing this hypothesis are evaluated. This article analyzes the parameter "minutiae count" as a function of time. Experiment variables included were secretion type (sebaceous-rich and eccrine-rich), substrate (glass and plastic), and exposure to light (dark, shade, and direct light). Depositions were sequentially visualized with Titanium Dioxide powder over a period of 6 months, photographed, and number of minutiae recorded. Results revealed a significant decrease of minutiae for eccrine-rich marks on glass but insignificant for sebaceous-rich marks on the same surface. However, significant degradation was observed for both types of secretions on plastic. The authors conclude that the distinctive prevalence of minutiae changes over time indicates with a high degree of certainty the hypothesis is valid and deserves additional exploration.

  17. Latent Fingermark Aging Patterns (Part I): Minutiae Count as One Indicator of Degradation.

    PubMed

    De Alcaraz-Fossoul, Josep; Mestres Patris, Cristina; Barrot Feixat, Carme; McGarr, Luke; Brandelli, Donna; Stow, Karen; Gené Badia, Manel

    2016-03-01

    The authors are exploring degradation patterns of latent fingermarks over time which can be quantitatively determined in a predictable manner by visual means. Several physical degradation parameters for assessing this hypothesis are evaluated. This article analyzes the parameter "minutiae count" as a function of time. Experiment variables included were secretion type (sebaceous-rich and eccrine-rich), substrate (glass and plastic), and exposure to light (dark, shade, and direct light). Depositions were sequentially visualized with Titanium Dioxide powder over a period of 6 months, photographed, and number of minutiae recorded. Results revealed a significant decrease of minutiae for eccrine-rich marks on glass but insignificant for sebaceous-rich marks on the same surface. However, significant degradation was observed for both types of secretions on plastic. The authors conclude that the distinctive prevalence of minutiae changes over time indicates with a high degree of certainty the hypothesis is valid and deserves additional exploration. PMID:27404605

  18. Principles and practice of hormetic treatment of aging and age-related diseases.

    PubMed

    Rattan, Suresh Is

    2008-02-01

    Aging is characterized by stochastic accumulation of molecular damage, progressive failure of maintenance and repair, and consequent onset of age-related diseases. Applying hormesis in aging research and therapy is based on the principle of stimulation of maintenance and repair pathways by repeated exposure to mild stress. Studies on the beneficial biological effects of repeated mild heat shock on human cells in culture, and other studies on the anti-aging and life-prolonging effects of proxidants, hypergravity, irradiation and ethanol on cells and organisms suggest that hormesis as an antiaging and gerontomodulatory approach has a promising future. Its clinical applications include prevention and treatment of diabetes, cataract, osteoporosis, dementia and some cancers.

  19. NADPH oxidases: key modulators in aging and age-related cardiovascular diseases?

    PubMed Central

    Sahoo, Sanghamitra; Meijles, Daniel N.; Pagano, Patrick J.

    2016-01-01

    Reactive oxygen species (ROS) and oxidative stress have long been linked to aging and diseases prominent in the elderly such as hypertension, atherosclerosis, diabetes and atrial fibrillation (AF). NADPH oxidases (Nox) are a major source of ROS in the vasculature and are key players in mediating redox signalling under physiological and pathophysiological conditions. In this review, we focus on the Nox-mediated ROS signalling pathways involved in the regulation of ‘longevity genes’ and recapitulate their role in age-associated vascular changes and in the development of age-related cardiovascular diseases (CVDs). This review is predicated on burgeoning knowledge that Nox-derived ROS propagate tightly regulated yet varied signalling pathways, which, at the cellular level, may lead to diminished repair, the aging process and predisposition to CVDs. In addition, we briefly describe emerging Nox therapies and their potential in improving the health of the elderly population. PMID:26814203

  20. Identification of MOAG-4/SERF as a regulator of age-related proteotoxicity.

    PubMed

    van Ham, Tjakko J; Holmberg, Mats A; van der Goot, Annemieke T; Teuling, Eva; Garcia-Arencibia, Moises; Kim, Hyun-eui; Du, Deguo; Thijssen, Karen L; Wiersma, Marit; Burggraaff, Rogier; van Bergeijk, Petra; van Rheenen, Jeroen; Jerre van Veluw, G; Hofstra, Robert M W; Rubinsztein, David C; Nollen, Ellen A A

    2010-08-20

    Fibrillar protein aggregates are the major pathological hallmark of several incurable, age-related, neurodegenerative disorders. These aggregates typically contain aggregation-prone pathogenic proteins, such as amyloid-beta in Alzheimer's disease and alpha-synuclein in Parkinson's disease. It is, however, poorly understood how these aggregates are formed during cellular aging. Here we identify an evolutionarily highly conserved modifier of aggregation, MOAG-4, as a positive regulator of aggregate formation in C. elegans models for polyglutamine diseases. Inactivation of MOAG-4 suppresses the formation of compact polyglutamine aggregation intermediates that are required for aggregate formation. The role of MOAG-4 in driving aggregation extends to amyloid-beta and alpha-synuclein and is evolutionarily conserved in its human orthologs SERF1A and SERF2. MOAG-4/SERF appears to act independently from HSF-1-induced molecular chaperones, proteasomal degradation, and autophagy. Our results suggest that MOAG-4/SERF regulates age-related proteotoxicity through a previously unexplored pathway, which will open up new avenues for research on age-related, neurodegenerative diseases.

  1. Stability-indicating UPLC method for determining related substances and degradants in dronedarone.

    PubMed

    Pydimarry, Surya Prakash Rao; Cholleti, Vijay Kumar; Vangala, Ranga Reddy

    2014-08-01

    A simple, sensitive and reproducible method was developed on ultra-performance liquid chromatography coupled with photodiode array detection for the quantitative determination of dronedarone hydrochloride (DRO) in drug substance and pharmaceutical dosage forms. The method is applicable for the quantification of related substances and assays of drug substances. Chromatographic separation was achieved on Acquity UPLC BEH C8 100 mm, 2.1 mm and 1.7 µm columns, using gradient elution within a short run time of 10.0 min. The eluted compounds were monitored at 288 nm, the flow rate was 0.5 mL/min and the column oven temperature was maintained at 40°C. The resolution of DRO and 11 impurities (potentials and by-products) was greater than 2.0 for all pairs of components. The high correlation coefficient value (>0.9995) indicates the clear correlations between the concentrations of investigated compound and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the relative standard deviation, were less than 2.5%. The accuracy and validity of the method were further ascertained by performing recovery studies via a spike method. The accuracy of the method, expressed as relative error, was satisfactory. No interference was observed from concomitant substances normally added to the tablets. DRO was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. DRO was found to degrade significantly in acid and base stress conditions and to remain stable in thermal, photolytic degradation, oxidative and hydrolytic conditions. The degradation products were well resolved from primary peak and its impurities, proving that the method is stability indicating. The developed method was validated as per International Conference on Harmonization guidelines with respect to specificity, limit of detection, limit of quantification, linearity, accuracy, precision, solution stability and robustness

  2. Age-related changes in human vitreous structure.

    PubMed

    Sebag, J

    1987-01-01

    Changes in vitreous structure that occur with aging are important in the pathogenesis of vitreous liquefaction (synchisis senilis), vitreous detachment, and retinal disease. Vitreous morphology was studied in 59 human eyes post-mortem using dark-field horizontal slit illumination of the entire dissected vitreous. In many individuals younger than 30 years, the vitreous was homogeneous in structure. Middle-aged individuals had macroscopic fibers in the central vitreous, which coursed anteroposteriorly and inserted into the vitreous base and the vitreous cortex, posteriorly. During senescence, the vitreous volume was reduced, the vitreous body was collapsed (syneresis), and the fibers were thickened, tortuous, and surrounded by liquid vitreous. This sequence of age-related changes probably results from a progressive reorganization of the hyaluronic acid and collagen molecular networks. Characterization of the molecular events underlying these changes will elucidate the mechanisms of the phenomena of synchisis, syneresis, and detachment, and may provide methods with which to prevent or induce vitreous detachment prophylactically.

  3. Age-related differences in arithmetic strategy sequential effects.

    PubMed

    Lemaire, Patrick

    2016-03-01

    In this article, I review a series of new findings concerning how age-related changes in strategic variations are modulated by sequential effects. Sequential effects refer to how strategy selection and strategy execution on current problems are influenced by which strategy is used on immediately preceding problems. Two sequential effects during strategy selection (i.e., strategy revisions and strategy perseverations) and during strategy execution (i.e., strategy switch costs and modulations of poorer strategy effects) are presented. I also discuss how these effects change with age during adulthood. These phenomena are important, as they shed light on arithmetic processes and how these processes change with age during adulthood. In particular, they speak to the role of executive control while participants select and execute arithmetic strategies. Finally, I discuss the implications of sequential effects for theories of strategies and of arithmetic.

  4. Age-related Shifts in Distortion Product Otoacoustic Emissions Peak-ratios and Amplitude Modulation Spectra

    PubMed Central

    Lai, Jesyin; Bartlett, Edward L.

    2015-01-01

    Amplitude modulation (AM) is an important temporal cue for precise speech and complex sound recognition. However, functional decline of the auditory periphery as well as degradation of central auditory processing due to aging can reduce the salience and resolution of temporal cues. Age-related deficits in central temporal processing have previously been observed at more rapid AM frequencies and various AM depths. These centrally observed changes result from cochlear changes compounded with changes along the ascending auditory pathway. In fact, a decrease in ability to detect temporally modulated sounds accurately could originate from changes in cochlear filtering properties and in cochlear mechanics due to aging. Nonetheless, few studies have examined cochlear mechanisms in AM detection. To assess integrity of the mechanical properties of the auditory periphery, distortion product otoacoustic emissions (DPOAEs) are a tool commonly used in clinics and in research. In this study, we measured DPOAEs to reveal age-related changes in peak f2/f1 ratio and degradation in AM detection by basilar membrane vibration. Two tones (f1 and f2, f2>f1) at various f2/f1 ratios and simultaneous presentation of one AM and one pure tone were used as stimuli to evoke DPOAEs. In addition of observing reduced DPOAE amplitudes and steeper slopes in the input-output DPOAE functions, higher peak f2/f1 ratios and broader f2/f1 tuning were also observed in aged animals. Aged animals generally had lower distortion product (DP) and first sideband (SB 1) responses evoked by an f1 pure tone and an f2 AM tone, regardless of whether the AM frequency was 45 Hz or 128 Hz. SB 1 thresholds, which corresponds to the smallest stimulus AM depth that can induce cochlear vibrations at the DP generator locus, were higher in aged animals as well. The results suggest that age-related changes in peak f2/f1 ratio and AM detection by basilar membrane vibration are consistent with a reduction in endocochlear

  5. Breed- and age-related differences in canine mammary tumors.

    PubMed

    Kim, Hyun-Woo; Lim, Ha-Young; Shin, Jong-Il; Seung, Byung-Joon; Ju, Jung-Hyung; Sur, Jung-Hyang

    2016-04-01

    Triple-negative breast cancer is a type of breast cancer that does not express the genes for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2). It is an important and clinically relevant condition as it has a poor prognosis and is difficult to treat. Basal-like triple-negative cancer is highly prevalent in both African-Americans and adolescents. We therefore examined whether such a cancer likewise occurs in specific breeds and age groups in dogs, focusing on basal-like triple-negative cancer in particular. In this study, 181 samples from dogs with malignant mammary carcinoma from the 5 most common breeds and 2 age groups in Korea were analyzed. Histological classification and molecular subtyping, including assessment of immunohistochemical findings, were carried out. Twenty-five of 28 (89.3%) triple-negative carcinomas were identified as basal-like triple-negative carcinomas. Analysis of associations of classified factors revealed that the shih tzu breed (9/25, 36.0%) and advanced-age (19/25, 76.0%) groups were characterized by higher prevalence of basal-like triple-negative tumors with diverse histological types and of a higher grade. These results suggest that breed- and age-related differences can be identified in canine mammary carcinoma and, notably, in the shih tzu breed and at older ages. Further investigation of these distinguishing characteristics of the shih tzu breed is warranted. PMID:27127342

  6. Breed- and age-related differences in canine mammary tumors

    PubMed Central

    Kim, Hyun-Woo; Lim, Ha-Young; Shin, Jong-Il; Seung, Byung-Joon; Ju, Jung-Hyung; Sur, Jung-Hyang

    2016-01-01

    Triple-negative breast cancer is a type of breast cancer that does not express the genes for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2). It is an important and clinically relevant condition as it has a poor prognosis and is difficult to treat. Basal-like triple-negative cancer is highly prevalent in both African-Americans and adolescents. We therefore examined whether such a cancer likewise occurs in specific breeds and age groups in dogs, focusing on basal-like triple-negative cancer in particular. In this study, 181 samples from dogs with malignant mammary carcinoma from the 5 most common breeds and 2 age groups in Korea were analyzed. Histological classification and molecular subtyping, including assessment of immunohistochemical findings, were carried out. Twenty-five of 28 (89.3%) triple-negative carcinomas were identified as basal-like triple-negative carcinomas. Analysis of associations of classified factors revealed that the shih tzu breed (9/25, 36.0%) and advanced-age (19/25, 76.0%) groups were characterized by higher prevalence of basal-like triple-negative tumors with diverse histological types and of a higher grade. These results suggest that breed- and age-related differences can be identified in canine mammary carcinoma and, notably, in the shih tzu breed and at older ages. Further investigation of these distinguishing characteristics of the shih tzu breed is warranted. PMID:27127342

  7. Age-related changes in the rat hippocampus.

    PubMed

    Is, Merih; Comunoglu, Nil Ustundag; Comunoglu, Cem; Eren, Bulent; Ekici, Isin Dogan; Ozkan, Ferda

    2008-05-01

    The human brain is uniquely powerful in its cognitive abilities, yet the hippocampal and neocortical circuits that mediate these complex functions are highly vulnerable during aging. In this study, we analyzed age-related changes in the rat hippocampus by studying newborn (1 month), middle-aged (12 months), and older (24 months) male and female Sprague-Dawley rats. We evaluated neuronal dystrophy, neuron scattering, and granulovacuolar degeneration in the hippocampal area using light microscopy, according to age and gender. We detected significant neuronal dystrophy in the CA1, CA2, and CA3 areas in male rats, and in the CA1, CA3, and CA4 areas in female rats. Degenerative changes, indicated by neuron scattering, were observed in the CA1, CA2, and CA3 areas of male and the CA2 and CA4 areas of female rats. Changes in all areas of the hippocampus were observed with increasing age; these changes included neuronal dystrophy and neuron scattering and did not differ significantly between male and female rats.

  8. Age-related changes in the meibomian gland.

    PubMed

    Nien, Chyong Jy; Paugh, Jerry R; Massei, Salina; Wahlert, Andrew J; Kao, Winston W; Jester, James V

    2009-12-01

    The purpose of this study was to characterize the age-related changes of the mouse meibomian gland. Eyelids from adult C57Bl/6 mice at 2, 6, 12 and 24 months of age were stained with specific antibodies against peroxisome proliferator activated receptor gamma (PPARgamma) to identify differentiating meibocytes, Oil Red O (ORO) to identify lipid, Ki67 nuclear antigen to identify cycling cells, B-lymphocyte-induced maturation protein-1 (Blimp1) to identify potential stem cells and CD45 to identify immune cells. Meibomian glands from younger mice (2 and 6 months) showed cytoplasmic and perinuclear staining with anti-PPARgamma antibodies with abundant ORO staining of small, intracellular lipid droplets. Meibomian glands from older mice (12 and 24 months) showed only nuclear PPARgamma localization with less ORO staining and significantly reduced acinar tissue (p < 0.04). Acini of older mice also showed significantly reduced (p < 0.004) numbers of Ki67 stained nuclei. While Blimp1 appeared to diffusely stain the superficial ductal epithelium, isolated cells were occasionally stained within the meibomian gland duct and acini of older mice that also stained with CD45 antibodies, suggesting the presence of infiltrating plasmacytoid cells. These findings suggest that there is altered PPARgamma receptor signaling in older mice that may underlie changes in cell cycle entry/proliferation, lipid synthesis and gland atrophy during aging. These results are consistent with the hypothesis that mouse meibomian glands undergo age-related changes similar to those identified in humans and may be used as a model for age-related meibomian gland dysfunction.

  9. A role of Bradyrhizobium elkanii and closely related strains in the degradation of methoxychlor in soil and surface water environments.

    PubMed

    Satsuma, Koji; Masuda, Minoru; Sato, Kiyoshi

    2013-01-01

    We have reported that a leguminous bacterial strain, Bradyrhizobium sp. strain 17-4, isolated from river sediment, phylogenetically very close to Bradyrhizobium elkanii, degraded methoxychlor through O-demethylation and oxidative dechlorination. In the present investigation, we found that B. elkanii (USDA94), a standard species deposited in the Culture Collection, degraded methoxychlor. Furthermore, Bradyrhizobium sp. strain 4-1, also very close to B. elkanii, isolated from Japanese paddy field soil, degraded methoxychlor. These B. elkanii and closely related strains degraded methoxychlor through almost identical metabolic pathways, and cleaved the phenyl ring and mineralized. In contrast, another representative Bradyrhizobium species, B. japonicum (USDA110), did not degrade methoxychlor at all. Based on these findings, B. elkanii and closely related strains are likely to play an important role not only in providing the readily biodegradable substrates but also in completely degrading (mineralizing) methoxychlor by themselves in the soil and surface water environment.

  10. Defining the boundary: age-related changes in childhood amnesia.

    PubMed

    Tustin, Karen; Hayne, Harlene

    2010-09-01

    Childhood amnesia refers to the inability of adults to recall events that occurred during their infancy and early childhood. Although it is generally assumed that children and adolescents also experience childhood amnesia, with limited exceptions, most empirical research on the phenomenon has focused exclusively on adults. Here, we developed a new Timeline procedure to directly compare the early memories reported by children, adolescents, and adults. Overall, the proportion of memories reported before the age of 3 years was greater for the children and adolescents relative to the adults. In addition, the single earliest memory reported by children and adolescents was at a younger age than that reported by adults. In fact, the earliest memories reported by the children and adolescents, but not the adults, were significantly younger than the traditional 3 (1/2)-year-old boundary of childhood amnesia. Regardless of the age of the rememberer, participants' early memories had the same episodic characteristics. We conclude that the boundary and the density of childhood amnesia may increase over the course of human development and that age-related changes in basic memory mechanisms make an important contribution to our understanding of the source of childhood amnesia.

  11. Exploring age-related brain degeneration in meditation practitioners.

    PubMed

    Luders, Eileen

    2014-01-01

    A growing body of research suggests that meditation practices are associated with substantial psychological as well as physiological benefits. In searching for the biological mechanisms underlying the beneficial impact of meditation, studies have revealed practice-induced alterations of neurotransmitters, brain activity, and cognitive abilities, just to name a few. These findings not only imply a close link between meditation and brain structure, but also suggest possible modulating effects of meditation on age-related brain atrophy. Given that normal aging is associated with significant loss of brain tissue, meditation-induced growth and/or preservation might manifest as a seemingly reduced brain age in meditators (i.e., cerebral measures characteristic of younger brains). Surprisingly, there are only three published studies that have addressed the question of whether meditation diminishes age-related brain degeneration. This paper reviews these three studies with respect to the brain attributes studied, the analytical strategies applied, and the findings revealed. The review concludes with an elaborate discussion on the significance of existing studies, implications and directions for future studies, as well as the overall relevance of this field of research.

  12. Mechanism of Inflammation in Age-Related Macular Degeneration

    PubMed Central

    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

  13. Auditory white noise reduces age-related fluctuations in balance.

    PubMed

    Ross, J M; Will, O J; McGann, Z; Balasubramaniam, R

    2016-09-01

    Fall prevention technologies have the potential to improve the lives of older adults. Because of the multisensory nature of human balance control, sensory therapies, including some involving tactile and auditory noise, are being explored that might reduce increased balance variability due to typical age-related sensory declines. Auditory white noise has previously been shown to reduce postural sway variability in healthy young adults. In the present experiment, we examined this treatment in young adults and typically aging older adults. We measured postural sway of healthy young adults and adults over the age of 65 years during silence and auditory white noise, with and without vision. Our results show reduced postural sway variability in young and older adults with auditory noise, even in the absence of vision. We show that vision and noise can reduce sway variability for both feedback-based and exploratory balance processes. In addition, we show changes with auditory noise in nonlinear patterns of sway in older adults that reflect what is more typical of young adults, and these changes did not interfere with the typical random walk behavior of sway. Our results suggest that auditory noise might be valuable for therapeutic and rehabilitative purposes in older adults with typical age-related balance variability. PMID:27495013

  14. Poly(aryl ethers) and related polysiloxane copolymer molecular coatings: Preparation and radiation degradation

    NASA Technical Reports Server (NTRS)

    Mcgrath, J. E.

    1982-01-01

    The radiation degradation of poly(arylene ether sulfones) and related materials is studied. These basic studies are important both as a means to developing stronger, more stable matrix resins for composite materials, as well as to improve the data base in regard to chemical structure-physical property relationships. Thirty homo and copolymers were synthesized, at least partially characterized and, in several cases suitable film casting techniques were developed. Four samples were chosen for initial radiation degradation. Poly(dimethyl siloxane) soft bocks/segments can preferentially migrate to the surface of copolymer films. Since siloxanes are utilized as thermal control coatings, this form of 'molecular' coating is of interest. The chemistry for preparing such copolymers with any of the polymers described was demonstrated.

  15. The emerging role of Notch pathway in ageing: Focus on the related mechanisms in age-related diseases.

    PubMed

    Balistreri, Carmela Rita; Madonna, Rosalinda; Melino, Gerry; Caruso, Calogero

    2016-08-01

    Notch signaling is an evolutionarily conserved pathway, which is fundamental for the development of all tissues, organs and systems of human body. Recently, a considerable and still growing number of studies have highlighted the contribution of Notch signaling in various pathological processes of the adult life, such as age-related diseases. In particular, the Notch pathway has emerged as major player in the maintenance of tissue specific homeostasis, through the control of proliferation, migration, phenotypes and functions of tissue cells, as well as in the cross-talk between inflammatory cells and the innate immune system, and in onset of inflammatory age-related diseases. However, until now there is a confounding evidence about the related mechanisms. Here, we discuss mechanisms through which Notch signaling acts in a very complex network of pathways, where it seems to have the crucial role of hub. Thus, we stress the possibility to use Notch pathway, the related molecules and pathways constituting this network, both as innovative (predictive, diagnostic and prognostic) biomarkers and targets for personalised treatments for age-related diseases. PMID:27328278

  16. Veterans have less age-related cognitive decline.

    PubMed

    McLay, R N; Lyketsos, C G

    2000-08-01

    Military service involves exposure to a number of stresses, both psychological and physical. On the other hand, military personnel generally maintain excellent fitness, and veterans have increased access to education and health care. The overall effect on age-related cognitive decline, whether for good or ill, of having served in the armed forces has not been investigated previously. In this study, we examined a diverse population of 208 veterans and 1,216 civilians followed as part of the Epidemiologic Catchment Area Study in 1981, 1982, and 1993 to 1996. We examined change in Mini-Mental State Examination (MMSE) score after a median of 11.5 years. Veterans were found to have significantly less decrease in MMSE scores at follow-up even after sex, race, and education were taken into account. These results suggest an overall positive effect of military service on the rate of age-related cognitive decline. PMID:10957857

  17. Bioavailable Carbon and the Relative Degradation State of Organic Matter in Active Layer and Permafrost Soils

    NASA Astrophysics Data System (ADS)

    Jastrow, J. D.; Burke, V. J.; Vugteveen, T. W.; Fan, Z.; Hofmann, S. M.; Lederhouse, J. S.; Matamala, R.; Michaelson, G. J.; Mishra, U.; Ping, C. L.

    2015-12-01

    The decomposability of soil organic carbon (SOC) in permafrost regions is a key uncertainty in efforts to predict carbon release from thawing permafrost and its impacts. The cold and often wet environment is the dominant factor limiting decomposer activity, and soil organic matter is often preserved in a relatively undecomposed and uncomplexed state. Thus, the impacts of soil warming and permafrost thaw are likely to depend at least initially on the genesis and past history of organic matter degradation before its stabilization in permafrost. We compared the bioavailability and relative degradation state of SOC in active layer and permafrost soils from Arctic tundra in Alaska. To assess readily bioavailable SOC, we quantified salt (0.5 M K2SO4) extractable organic matter (SEOM), which correlates well with carbon mineralization rates in short-term soil incubations. To assess the relative degradation state of SOC, we used particle size fractionation to isolate fibric (coarse) from more degraded (fine) particulate organic matter (POM) and separated mineral-associated organic matter into silt- and clay-sized fractions. On average, bulk SOC concentrations in permafrost were lower than in comparable active layer horizons. Although SEOM represented a very small proportion of the bulk SOC, this proportion was greater in permafrost than in comparable active layer soils. A large proportion of bulk SOC was found in POM for all horizons. Even for mineral soils, about 40% of bulk SOC was in POM pools, indicating that organic matter in both active layer and permafrost mineral soils was relatively undecomposed compared to typical temperate soils. Not surprisingly, organic soils had a greater proportion of POM and mineral soils had greater silt- and clay-sized carbon pools, while cryoturbated soils were intermediate. For organic horizons, permafrost organic matter was generally more degraded than in comparable active layer horizons. However, in mineral and cryoturbated horizons

  18. Chlorophyll degradation: the tocopherol biosynthesis-related phytol hydrolase in Arabidopsis seeds is still missing.

    PubMed

    Zhang, Wei; Liu, Tianqi; Ren, Guodong; Hörtensteiner, Stefan; Zhou, Yongming; Cahoon, Edgar B; Zhang, Chunyu

    2014-09-01

    Phytyl diphosphate (PDP) is the prenyl precursor for tocopherol biosynthesis. Based on recent genetic evidence, PDP is supplied to the tocopherol biosynthetic pathway primarily by chlorophyll degradation and sequential phytol phosphorylation. Three enzymes of Arabidopsis (Arabidopsis thaliana) are known to be capable of removing the phytol chain from chlorophyll in vitro: chlorophyllase1 (CLH1), CLH2, and pheophytin pheophorbide hydrolase (PPH), which specifically hydrolyzes pheophytin. While PPH, but not chlorophyllases, is required for in vivo chlorophyll breakdown during Arabidopsis leaf senescence, little is known about the involvement of these phytol-releasing enzymes in tocopherol biosynthesis. To explore the origin of PDP for tocopherol synthesis, seed tocopherol concentrations were determined in Arabidopsis lines engineered for seed-specific overexpression of PPH and in single and multiple mutants in the three genes encoding known dephytylating enzymes. Except for modestly increasing tocopherol content observed in the PPH overexpressor, none of the remaining lines exhibited significantly reduced tocopherol concentrations, suggesting that the known chlorophyll-derived phytol-releasing enzymes do not play major roles in tocopherol biosynthesis. Tocopherol content of seeds from double mutants in NONYELLOWING1 (NYE1) and NYE2, regulators of chlorophyll degradation, had modest reduction compared with wild-type seeds, although mature seeds of the double mutant retained significantly higher chlorophyll levels. These findings suggest that NYEs may play limited roles in regulating an unknown tocopherol biosynthesis-related phytol hydrolase. Meanwhile, seeds of wild-type over-expressing NYE1 had lower tocopherol levels, suggesting that phytol derived from NYE1-dependent chlorophyll degradation probably doesn't enter tocopherol biosynthesis. Potential routes of chlorophyll degradation are discussed in relation to tocopherol biosynthesis.

  19. Smoking and Age-Related Macular Degeneration: Review and Update

    PubMed Central

    Velilla, Sara; García-Medina, José Javier; García-Layana, Alfredo; Pons-Vázquez, Sheila; Pinazo-Durán, M. Dolores; Gómez-Ulla, Francisco; Arévalo, J. Fernando; Díaz-Llopis, Manuel; Gallego-Pinazo, Roberto

    2013-01-01

    Age-related macular degeneration (AMD) is one of the main socioeconomical health issues worldwide. AMD has a multifactorial etiology with a variety of risk factors. Smoking is the most important modifiable risk factor for AMD development and progression. The present review summarizes the epidemiological studies evaluating the association between smoking and AMD, the mechanisms through which smoking induces damage to the chorioretinal tissues, and the relevance of advising patients to quit smoking for their visual health. PMID:24368940

  20. Age-Related Hyperkyphosis: Its Causes, Consequences, and Management

    PubMed Central

    Katzman, Wendy B.; Wanek, Linda; Shepherd, John A.; Sellmeyer, Deborah E.

    2010-01-01

    Age-related postural hyperkyphosis is an exaggerated anterior curvature of the thoracic spine, sometimes referred to as Dowager’s hump or gibbous deformity. This condition impairs mobility,2,31 and increases the risk of falls33 and fractures.26 The natural history of hyperkyphosis is not firmly established. Hyperkyphosis may develop from either muscle weakness and degenerative disc disease, leading to vertebral fractures and worsening hyperkyphosis, or from initial vertebral fractures that precipitate its development. PMID:20511692

  1. DNA damage and repair in telomeres: relation to aging.

    PubMed Central

    Kruk, P A; Rampino, N J; Bohr, V A

    1995-01-01

    We have established a method for the detection of DNA damage and its repair in human telomeres, the natural ends of chromosomes which are necessary for replication and critical for chromosomal stability. We find that ultraviolet light-induced pyrimidine dimers in telomeric DNA are repaired less efficiently than endogenous genes but more efficiently than inactive, noncoding regions. We have also measured telomeric length, telomeric DNA damage, and its repair in relation to the progression of aging. Telomeres are shorter in fibroblasts from an old donor compared to fibroblasts from a young donor, shortest in cells from a patient with the progeroid disorder Werner syndrome, and relatively long in fibroblasts from a patient with Alzheimer disease. Telomeric DNA repair efficiency is lower in cells from an old donor than in cells from a young donor, normal in Alzheimer cells, and slightly lower in Werner cells. It is possible that this decline in telomeric repair with aging is of functional significance to an age-related decline in genomic stability. Images Fig. 1 Fig. 2 PMID:7816828

  2. [Diagnostic Criteria for Atrophic Age-related Macular Degeneration].

    PubMed

    Takahashi, Kanji; Shiraga, Fumio; Ishida, Susumu; Kamei, Motohiro; Yanagi, Yasuo; Yoshimura, Nagahisa

    2015-10-01

    Diagnostic criteria for dry age-related macular degeneration is described. Criteria include visual acuity, fundscopic findings, diagnostic image findings, exclusion criteria and classification of severity grades. Essential findings to make diagnosis as "geographic atrophy" are, 1) at least 250 μm in diameter, 2) round/oval/cluster-like or geographic in shape, 3) sharp delineation, 4) hypopigmentation or depigmentation in retinal pigment epithelium, 5) choroidal vessels are more visible than in surrounding area. Severity grades were classified as mild, medium and severe by relation of geographic atrophy to the fovea and attendant findings. PMID:26571627

  3. Genetic and Environmental Factors in Age-Related Hearing Impairment.

    PubMed

    Momi, Sukhleen K; Wolber, Lisa E; Fabiane, Stella Maris; MacGregor, Alex J; Williams, Frances M K

    2015-08-01

    Age-related hearing impairment (ARHI) is a common condition with complex etiology but a recognized genetic component. Heritability estimates for pure tone audiogram-determined hearing ability lie in the range 26-75%. The speech-in-noise (SIN) auditory test, however, may be better at encapsulating ARHI symptoms, particularly the diminished ability to segregate environmental sounds into comprehendible auditory streams. As heritability of SIN has not previously been reported, we explored the genetic and environmental contributions to ARHI determined by SIN in 2,076 twins (87.8% female) aged 18-87 (mean age 54.4). SIN was found to be significantly heritable (A, unadjusted for age=40%; 95% confidence intervals, CI=32%-47%). With age adjustment, heritability fell (A=25%; 95% CI=16-33%), and a relatively strong influence of environmental exposure unshared within twin siblings was identified (E=75%). To explore the environmental aspects further, we assessed the influence of diet (through the Food Frequency Questionnaire, FFQ), smoking (through self-report and cotinine metabolite levels) and alcohol intake (through the FFQ). A negative influence of high cholesterol diet was observed after adjustment (p=.037). A protective effect of raised serum high-density lipoprotein (HDL) cholesterol levels was observed after adjustment (p=.004). This study is the first assessment of the genetic and environmental influence on SIN perception. The findings suggest SIN is less heritable than pure tone audiogram (PTA) ability and highly influenced by the environment unique to each twin. Furthermore, a possible role of dietary fat in the etiology of ARHI is highlighted.

  4. Age-related modifications in neural cardiovascular control.

    PubMed

    Ferrari, A U

    1992-09-01

    Integrated cardiovascular responses to a range of different stimuli, as well as the overall, spontaneously occurring variability in blood pressure and heart rate, undergo complex changes with aging. A general trend is that homeostatic control mechanisms lose part of their ability to modulate heart rate and to buffer the concomitant blood pressure variations; the two phenomena are possibly linked by a cause-effect relationship. A detailed analysis of the age-related changes in the major reflex systems reveals a clear-cut impairment in arterial baroreceptor control of the heart rate, but much less pronounced changes in its control of blood pressure, on the other hand, both the hemodynamic and humoral components of the cardiopulmonary reflex appear to be markedly attenuated. The experimental evidence of the mechanisms underlying these changes is still largely incomplete, and it appears that the gaps will have to be filled by a systematic, detailed analysis, i.e., that no generalizations or extrapolations will be possible. Indeed, the data available so far indicate that the age-related alterations are highly non-uniform, some functions undergoing a definite impairment but others being much better preserved and some being even enhanced; thus aging is by no means associated with a generalized decline in cardiovascular functions and should instead be viewed as a complex, highly selective process. These peculiar biological features of the aging phenomena merit further investigation in both the cardiovascular and the other organ systems, in order to verify the possibility that currently unrecognized homeostatic potentials in the elderly subject may be exploited to advance his/her clinical management in health and disease.

  5. Age-related changes to the production of linguistic prosody

    NASA Astrophysics Data System (ADS)

    Barnes, Daniel R.

    The production of speech prosody (the rhythm, pausing, and intonation associated with natural speech) is critical to effective communication. The current study investigated the impact of age-related changes to physiology and cognition in relation to the production of two types of linguistic prosody: lexical stress and the disambiguation of syntactically ambiguous utterances. Analyses of the acoustic correlates of stress: speech intensity (or sound-pressure level; SPL), fundamental frequency (F0), key word/phrase duration, and pause duration revealed that both young and older adults effectively use these acoustic features to signal linguistic prosody, although the relative weighting of cues differed by group. Differences in F0 were attributed to age-related physiological changes in the laryngeal subsystem, while group differences in duration measures were attributed to relative task complexity and the cognitive-linguistic load of these respective tasks. The current study provides normative acoustic data for older adults which informs interpretation of clinical findings as well as research pertaining to dysprosody as the result of disease processes.

  6. Age-related mate choice in the wandering albatross.

    PubMed

    Jouventin; Lequette; Dobson

    1999-05-01

    We studied mate choice in the wandering albatross, Diomedea exulans, using data from 32 years of banding returns in the population of the Crozet Islands. We studied mating choices in a single year, when the Crozet Islands population was male biased (8:5, males:females). Thus, we expected that females might show great flexibility of choice of partners. Because age and experience might influence mate choice, we tested the expectation that females would choose the oldest and most experienced males for pair bonding. Pair bonds usually last until one member of the pair dies (0.3% of the birds 'divorce'), so mate choice should be especially important. We found that the ages of males and females in both displaying and bonded (breeding) pairs were significantly correlated. These age-associated pairings were not a passive phenomenon, but appeared to be due to an active process of selection of mates of similar age. First-time breeders sought mates of similar age, but preferred those with the most experience. Remating, experienced birds whose mates had died did not pair with individuals of significantly similar age, but predominantly paired with other widowed birds that, on average, were also relatively old. Mate fidelity in wandering albatrosses may be due to the cost of finding and bonding with a new mate. Pair bonds, and thus breeding, took an average of 3.2 and 2.3 years to establish, for males and females, respectively. Thus, remating exerts a potential average reproductive cost of about 15% of lifetime reproductive success. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10328796

  7. Sex-Related and Age-Related Differences in Knee Strength of Basketball Players Ages 11-17 Years.

    PubMed

    Buchanan, Patricia A.; Vardaxis, Vassilios G.

    2003-09-01

    OBJECTIVE: To assess hamstrings and quadriceps strength of basketball players ages 11-13 and 15-17 years. DESIGN AND SETTING: This cross-sectional study occurred during the 2000 American Youth Basketball Tour National Tournament. We investigated whether sex- or age-related strength differences existed among study participants. SUBJECTS: Forty-one tournament participants (22 girls, 19 boys; 11-13 or 15-17 years old) who reported no history of knee sprain or surgery were recruited. MEASUREMENTS: We used a Cybex II dynamometer to obtain isokinetic concentric peak torques relative to body mass (Nm/kg) at 60 degrees /s for hamstrings and quadriceps bilaterally. From average peak torques, we determined ipsilateral hamstrings:quadriceps and homologous muscle-group ratios. RESULTS: Correlations between hamstrings and quadriceps strength measures ranged from 0.78 to 0.97. Players 15-17 years old had greater relative hamstrings and quadriceps strength than 11- to 13-year-old athletes. Age and sex interacted significantly for quadriceps strength. The quadriceps strength of 15- to 17-year-old girls did not differ from that of 11- to 13-year-old girls, whereas 15- to 17-year-old boys had stronger quadriceps than 11- to 13-year-old boys. Boys 15-17 years old had greater quadriceps strength than girls 15-17 years old. CONCLUSIONS: This study is unique in providing normative data for the hamstrings and quadriceps strength of basketball players 11-13 and 15-17 years old. Age-related strength differences did not occur consistently between the sexes, as girls 11-13 and 15-17 years old had similar relative quadriceps strength.

  8. Exploring the microbiota dynamics related to vegetable biomasses degradation and study of lignocellulose-degrading bacteria for industrial biotechnological application

    NASA Astrophysics Data System (ADS)

    Ventorino, Valeria; Aliberti, Alberto; Faraco, Vincenza; Robertiello, Alessandro; Giacobbe, Simona; Ercolini, Danilo; Amore, Antonella; Fagnano, Massimo; Pepe, Olimpia

    2015-02-01

    The aims of this study were to evaluate the microbial diversity of different lignocellulosic biomasses during degradation under natural conditions and to isolate, select, characterise new well-adapted bacterial strains to detect potentially improved enzyme-producing bacteria. The microbiota of biomass piles of Arundo donax, Eucalyptus camaldulensis and Populus nigra were evaluated by high-throughput sequencing. A highly complex bacterial community was found, composed of ubiquitous bacteria, with the highest representation by the Actinobacteria, Proteobacteria, Bacteroidetes and Firmicutes phyla. The abundances of the major and minor taxa retrieved during the process were determined by the selective pressure produced by the lignocellulosic plant species and degradation conditions. Moreover, cellulolytic bacteria were isolated using differential substrates and screened for cellulase, cellobiase, xylanase, pectinase and ligninase activities. Forty strains that showed multienzymatic activity were selected and identified. The highest endo-cellulase activity was seen in Promicromonospora sukumoe CE86 and Isoptericola variabilis CA84, which were able to degrade cellulose, cellobiose and xylan. Sixty-two percent of bacterial strains tested exhibited high extracellular endo-1,4-ß-glucanase activity in liquid media. These approaches show that the microbiota of lignocellulosic biomasses can be considered an important source of bacterial strains to upgrade the feasibility of lignocellulose conversion for the `greener' technology of second-generation biofuels.

  9. Exploring the microbiota dynamics related to vegetable biomasses degradation and study of lignocellulose-degrading bacteria for industrial biotechnological application

    PubMed Central

    Ventorino, Valeria; Aliberti, Alberto; Faraco, Vincenza; Robertiello, Alessandro; Giacobbe, Simona; Ercolini, Danilo; Amore, Antonella; Fagnano, Massimo; Pepe, Olimpia

    2015-01-01

    The aims of this study were to evaluate the microbial diversity of different lignocellulosic biomasses during degradation under natural conditions and to isolate, select, characterise new well-adapted bacterial strains to detect potentially improved enzyme-producing bacteria. The microbiota of biomass piles of Arundo donax, Eucalyptus camaldulensis and Populus nigra were evaluated by high-throughput sequencing. A highly complex bacterial community was found, composed of ubiquitous bacteria, with the highest representation by the Actinobacteria, Proteobacteria, Bacteroidetes and Firmicutes phyla. The abundances of the major and minor taxa retrieved during the process were determined by the selective pressure produced by the lignocellulosic plant species and degradation conditions. Moreover, cellulolytic bacteria were isolated using differential substrates and screened for cellulase, cellobiase, xylanase, pectinase and ligninase activities. Forty strains that showed multienzymatic activity were selected and identified. The highest endo-cellulase activity was seen in Promicromonospora sukumoe CE86 and Isoptericola variabilis CA84, which were able to degrade cellulose, cellobiose and xylan. Sixty-two percent of bacterial strains tested exhibited high extracellular endo-1,4-ß-glucanase activity in liquid media. These approaches show that the microbiota of lignocellulosic biomasses can be considered an important source of bacterial strains to upgrade the feasibility of lignocellulose conversion for the ‘greener' technology of second-generation biofuels. PMID:25641069

  10. THE ENERGY-REDOX AXIS IN AGING AND AGE-RELATED NEURODEGENERATION

    PubMed Central

    Yap, Li-Peng; Garcia, Jerome V.; Han, Derick; Cadenas, Enrique

    2009-01-01

    Decrease in mitochondrial energy-transducing capacity is a feature of the aging process that accompanies redox alterations, such as increased generation of mitochondrial oxidants, altered GSH status, and increased protein oxidation. The decrease in mitochondrial energy-transducing capacity and altered redox status should be viewed as a concerted process that embodies the mitochondrial energy – redox axis and is linked through various mechanisms including: (a) an inter-convertible reducing equivalents pool (i.e., NAD(P)+/NAD(P)H) and (b) redox-mediated protein post-translational modifications involved in energy metabolism. The energy–redox axis provides the rationale for therapeutic approaches targeted to each or both component(s) of the axis that effectively preserves or improve mitochondrial function and that have implications for aging and age-related neurodegenerative disorders. PMID:19716388

  11. Complexity in caring for an ageing heart failure population: concomitant chronic conditions and age related impairments.

    PubMed

    De Geest, Sabina; Steeman, Els; Leventhal, Marcia E; Mahrer-Imhof, Romy; Hengartner-Kopp, Beatrice; Conca, Antoinette; Bernasconi, Arlette T; Petry, Heidi; Brunner-La Rocca, Hanspeter

    2004-12-01

    The complexity of caring for the ageing heart failure (HF) population is further complicated by concomitant chronic conditions (i.e., polypharmacy, depression), age related impairments (i.e., hearing, visual and cognitive impairments, impairments in activities of daily living (ADL/IADL), and other issues (e.g., health illiteracy, lack of social support). This paper provides an overview of these risk factors, outlines how they individually and in interplay endanger favourable outcome by putting patients at risk for poor self-management. Moreover, suggestions are made on how these issues could be addressed and integrated in heart failure management by applying gerontological care principles in caring for the ageing heart failure population.

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

    PubMed Central

    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. PMID:26605694

  13. Relative importance of natural disturbances and habitat degradation on snail kite population dynamics

    USGS Publications Warehouse

    Martin, J.; Kitchens, W.M.; Cattau, Christopher E.; Oli, M.K.

    2008-01-01

    Natural disturbances and habitat degradation are major factors influencing the dynamics and persistence of many wildlife populations, yet few large-scale studies have explored the relative influence of these factors on the dynamics and persistence of animal populations. We used longterm demographic data and matrix population models to examine the potential effects of habitat degradation and natural disturbances on the dynamics of the endangered snail kite Rostrhamus sociabilis in Florida, USA. We found that estimates of stochastic population growth rate were low (0.90). Population growth rate (??) during the first half or our study period (1992 to 1998) was substantially greater than during the second half (1999 to 2005). These 2 periods were characterized by contrasting hydrological conditions. Although ?? was most sensitive to changes in adult survival, the analysis of life table response experiments revealed that a reduction in fertility of kites accounted for >80% of the observed decline in population growth rate. We examined the possibility that the reduction in ?? was caused by (1) habitat degradation due to management, (2) an increase in frequency of moderate drying events in recent years, and (3) both habitat degradation and an increase in frequency of moderate drying events. Our results suggest that both factors could potentially contribute to a large decrease in population growth rate. Our study highlights the importance of simultaneously considering short- and long-term effects of disturbances when modeling population dynamics. Indeed, focusing exclusively on one type of effect may be misleading to both our understanding of the ecological dynamics of the system and to management. The relevance of our results to management is heightened because the snail kite has been selected as a key performance measure of one of the most ambitious ecosystem restoration projects ever undertaken. ?? Inter-Research 2008.

  14. Age-Related Deficits in Reality Monitoring of Action Memories

    PubMed Central

    McDaniel, Mark A.; Lyle, Keith B.; Butler, Karin M.; Dornburg, Courtney C.

    2008-01-01

    We describe three theoretical accounts of age-related increases in falsely remembering that imagined actions were performed (Thomas & Bulevich, 2006). To investigate these accounts and further explore age-related changes in reality monitoring of action memories, we used a new paradigm in which actions were (a) imagined-only (b) actually performed, or (c) both imagined and performed. Older adults were more likely than younger adults to misremember the source of imagined-only actions, with older adults’ more often specifying that the action was imagined and also that it was performed. For both age groups, as repetitions of the imagined-only events increased, illusions that the actions were only performed decreased. These patterns suggest that both older and younger adults utilize qualitative characteristics when making reality-monitoring judgments and that repeated imagination produces richer records of both sensory details and cognitive operations. However, sensory information derived from imagination appears to be more similar to that derived from performance for older than younger adults. PMID:18808253

  15. Age-Related Loss of Muscle Mass and Strength

    PubMed Central

    Goldspink, Geoffrey

    2012-01-01

    Age-related muscle wasting and increased frailty are major socioeconomic as well as medical problems. In the quest to extend quality of life it is important to increase the strength of elderly people sufficiently so they can carry out everyday tasks and to prevent them falling and breaking bones that are brittle due to osteoporosis. Muscles generate the mechanical strain that contributes to the maintenance of other musculoskeletal tissues, and a vicious circle is established as muscle loss results in bone loss and weakening of tendons. Molecular and proteomic approaches now provide strategies for preventing age-related muscle wasting. Here, attention is paid to the role of the GH/IGF-1 axis and the special role of the IGFI-Ec (mechano growth factor/MGF) which is derived from the IGF-I gene by alternative splicing. During aging MGF levels decline but when administered MGF activates the muscle satellite (stem) cells that “kick start” local muscle repair and induces hypertrophy. PMID:22506111

  16. Sex differences in relative age effects among Japanese athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2012-08-01

    The present study investigated the relative age effect (RAE), a biased distribution of elite athletes' birthdates, in Japanese female athletes. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. A total of 1,335 female athletes were evaluated from six sports: softball, soccer, volleyball, basketball, badminton, and track and field (long distance), and compared with male athletes. All athletes played in the top level of Japanese leagues for each sport in 2010. Distribution of the birth dates in each female sport showed a significant RAE only in volleyball. For males, significant RAEs were observed in baseball, soccer, and track and field. Findings suggest that the determinants of RAEs in sports may differ between males and females. PMID:23033755

  17. Sex differences in relative age effects among Japanese athletes.

    PubMed

    Nakata, Hiroki; Sakamoto, Kiwako

    2012-08-01

    The present study investigated the relative age effect (RAE), a biased distribution of elite athletes' birthdates, in Japanese female athletes. Japan applies a unique annual-age grouping for sport and education, which is from April 1 to March 31 of the following year. A total of 1,335 female athletes were evaluated from six sports: softball, soccer, volleyball, basketball, badminton, and track and field (long distance), and compared with male athletes. All athletes played in the top level of Japanese leagues for each sport in 2010. Distribution of the birth dates in each female sport showed a significant RAE only in volleyball. For males, significant RAEs were observed in baseball, soccer, and track and field. Findings suggest that the determinants of RAEs in sports may differ between males and females.

  18. Relation of Chlorofluorocarbon Ground-Water Age Dates to Water Quality in Aquifers of West Virginia

    USGS Publications Warehouse

    ,; Kurt, J.; Kozar, Mark D.

    2007-01-01

    The average apparent age of ground water in fractured-bedrock aquifers in West Virginia was determined using chlorofluorocarbon (CFC) dating methods. Since the introduction of CFC gases as refrigerants in the late 1930s, atmospheric concentrations have increased until production ceased in the mid-1990s. CFC dating methods are based on production records that date to the early 1940s, and the preservation of atmospheric CFC concentrations in ground water at the time of recharge. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Ambient Ground-Water Monitoring Network (AGN) programs in West Virginia from 1997 to 2005, 80 samples from the Appalachian Plateaus Physiographic Province, 27 samples from the Valley and Ridge Physiographic Province, and 5 samples from the Ohio River alluvial aquifers were collected to estimate ground-water ages in aquifers of West Virginia. Apparent CFC ages of water samples from West Virginia aquifers ranged from 5.8 to 56 years. In the Appalachian Plateaus, topographically driven ground-water flow is evident from apparent ages of water samples from hilltop, hillside, and valley settings (median apparent ages of 12, 14, and 25 years, respectively). Topographic setting was the only factor that was found to be related to apparent ground-water age in the Plateaus at the scale of this study. Similar relations were not found in Valley and Ridge aquifers, indicating that other factors such as bedding or geologic structure may serve larger roles in controlling ground-water flow in that physiographic province. Degradation of CFCs was common in samples collected from methanogenic/anoxic aquifers in the Appalachian Plateaus and suboxic to anoxic aquifers in the Valley and Ridge. CFC contamination was most common in Ohio River alluvial aquifers and carbonate units of the Valley and Ridge, indicating that these highly transmissive surficial aquifers are the most vulnerable to water-quality degradation and may

  19. Individual and age-related variation in chromatic contrast adaptation

    PubMed Central

    Elliott, Sarah L.; Werner, John S.; Webster, Michael A.

    2012-01-01

    Precortical color channels are tuned primarily to the LvsM (stimulation of L and M cones varied, but S cone stimulation held constant) or SvsLM (stimulation of S cones varied, but L and M cone stimulation held constant) cone-opponent (cardinal) axes, but appear elaborated in the cortex to form higher-order mechanisms tuned to both cardinal and intermediate directions. One source of evidence for these higher-order mechanisms has been the selectivity of color contrast adaptation for noncardinal directions, yet the degree of this selectivity has varied widely across the small sample of observers tested in previous studies. This study explored the possible bases for this variation, and in particular tested whether it reflected age-related changes in the distribution or tuning of color mechanisms. Observers included 15 younger (18–22 years of age) and 15 older individuals (66–82), who adapted to temporal modulations along one of four chromatic axes (two cardinal and two intermediate axes) and then matched the hue and contrast of test stimuli lying along eight different directions in the equiluminant plane. All observers exhibited aftereffects that were selective for both the cardinal and intermediate directions, although selectivity was weaker for the intermediate axes. The degree of selectivity increased with the magnitude of adaptation for all axes, and thus adaptation strength alone may account for much of the variance in selectivity among observers. Older observers showed a stronger magnitude of adaptation thus, surprisingly, more conspicuous evidence for higher-order mechanisms. For both age groups the aftereffects were well predicted by response changes in chromatic channels with linear spectral sensitivities, and there was no evidence for weakened channel tuning with aging. The results suggest that higher-order mechanisms may become more exposed in observers or conditions in which the strength of adaptation is greater, and that both chromatic contrast

  20. The genetics of age-related macular degeneration.

    PubMed

    Gorin, M B; Breitner, J C; De Jong, P T; Hageman, G S; Klaver, C C; Kuehn, M H; Seddon, J M

    1999-11-01

    Age-related macular degeneration (AMD) is increasingly recognized as a complex genetic disorder in which one or more genes contribute to an individual's susceptibility for developing the condition. Twin and family studies as well as population-based genetic epidemiologic methods have convincingly demonstrated the importance of genetics in AMD, though the extent of heritability, the number of genes involved, and the phenotypic and genetic heterogeneity of the condition remain unresolved. The extent to which other hereditary macular dystrophies such as Stargardts disease, familial radial drusen (malattia leventinese), Best's disease, and peripherin/RDS-related dystrophy are related to AMD remains unclear. Alzheimer's disease, another late onset, heterogeneous degenerative disorder of the central nervous system, offers a valuable model for identifying the issues that confront AMD genetics.

  1. Dietary folate improves age-related decreases in lymphocyte function.

    PubMed

    Field, Catherine J; Van Aerde, Arne; Drager, Kelly L; Goruk, Susan; Basu, Tapan

    2006-01-01

    Although low folate status is thought to be fairly common in the older population, its implication on immunity has not been adequately investigated. Using 11-month-old and 23-month-old male rats (Fisher 344), the present study was undertaken to examine the modifying effects of feeding a control diet (NIH-07) supplemented with folate (35.7 mg/kg) for 3 weeks on the immune cells of spleen and mesenteric lymph node (MLN) origin. The serum concentrations of folate along with vitamin B(12) were elevated in response to the folate supplementation (P<.05). These results were accompanied by an improved proliferative response (stimulation index) to mitogens in both the spleen and MLNs (P<.05). The proportion of T cells in the MLNs, but not in the spleen, was significantly increased in rats fed a diet supplemented with folate. In the spleen, the folate-supplemented diet prevented the age-associated decrease (P<.05) in the production of interferon (IFN)alpha by unstimulated cells and the decrease in T-helper (Th)1/Th2-type response after stimulation with phorbol myristate acetate and ionomycin. In the MLNs, on the other hand, the folate-supplemented diet failed to influence any age-related increase in interleukin (IL)-2, tumor necrosis factor alpha and IFNgamma following stimulation but did result in a significantly increased production of IL-4 (P<.05). Overall, this study provides data suggesting that aging is associated with changes in the proportion of T cells, the ability of immune cells to proliferate and the production of cytokines after stimulation. Supplementing a folate-sufficient diet with additional folate improves proliferative response to mitogens, the distribution of T cells in the MLNs and the age-related changes in cytokine production in the spleen. These results suggest that the dietary folate requirement may be higher in the older population than in the younger population to support immune functions.

  2. Aging-related tau astrogliopathy (ARTAG): harmonized evaluation strategy.

    PubMed

    Kovacs, Gabor G; Ferrer, Isidro; Grinberg, Lea T; Alafuzoff, Irina; Attems, Johannes; Budka, Herbert; Cairns, Nigel J; Crary, John F; Duyckaerts, Charles; Ghetti, Bernardino; Halliday, Glenda M; Ironside, James W; Love, Seth; Mackenzie, Ian R; Munoz, David G; Murray, Melissa E; Nelson, Peter T; Takahashi, Hitoshi; Trojanowski, John Q; Ansorge, Olaf; Arzberger, Thomas; Baborie, Atik; Beach, Thomas G; Bieniek, Kevin F; Bigio, Eileen H; Bodi, Istvan; Dugger, Brittany N; Feany, Mel; Gelpi, Ellen; Gentleman, Stephen M; Giaccone, Giorgio; Hatanpaa, Kimmo J; Heale, Richard; Hof, Patrick R; Hofer, Monika; Hortobágyi, Tibor; Jellinger, Kurt; Jicha, Gregory A; Ince, Paul; Kofler, Julia; Kövari, Enikö; Kril, Jillian J; Mann, David M; Matej, Radoslav; McKee, Ann C; McLean, Catriona; Milenkovic, Ivan; Montine, Thomas J; Murayama, Shigeo; Lee, Edward B; Rahimi, Jasmin; Rodriguez, Roberta D; Rozemüller, Annemieke; Schneider, Julie A; Schultz, Christian; Seeley, William; Seilhean, Danielle; Smith, Colin; Tagliavini, Fabrizio; Takao, Masaki; Thal, Dietmar Rudolf; Toledo, Jon B; Tolnay, Markus; Troncoso, Juan C; Vinters, Harry V; Weis, Serge; Wharton, Stephen B; White, Charles L; Wisniewski, Thomas; Woulfe, John M; Yamada, Masahito; Dickson, Dennis W

    2016-01-01

    Pathological accumulation of abnormally phosphorylated tau protein in astrocytes is a frequent, but poorly characterized feature of the aging brain. Its etiology is uncertain, but its presence is sufficiently ubiquitous to merit further characterization and classification, which may stimulate clinicopathological studies and research into its pathobiology. This paper aims to harmonize evaluation and nomenclature of aging-related tau astrogliopathy (ARTAG), a term that refers to a morphological spectrum of astroglial pathology detected by tau immunohistochemistry, especially with phosphorylation-dependent and 4R isoform-specific antibodies. ARTAG occurs mainly, but not exclusively, in individuals over 60 years of age. Tau-immunoreactive astrocytes in ARTAG include thorn-shaped astrocytes at the glia limitans and in white matter, as well as solitary or clustered astrocytes with perinuclear cytoplasmic tau immunoreactivity that extends into the astroglial processes as fine fibrillar or granular immunopositivity, typically in gray matter. Various forms of ARTAG may coexist in the same brain and might reflect different pathogenic processes. Based on morphology and anatomical distribution, ARTAG can be distinguished from primary tauopathies, but may be concurrent with primary tauopathies or other disorders. We recommend four steps for evaluation of ARTAG: (1) identification of five types based on the location of either morphologies of tau astrogliopathy: subpial, subependymal, perivascular, white matter, gray matter; (2) documentation of the regional involvement: medial temporal lobe, lobar (frontal, parietal, occipital, lateral temporal), subcortical, brainstem; (3) documentation of the severity of tau astrogliopathy; and (4) description of subregional involvement. Some types of ARTAG may underlie neurological symptoms; however, the clinical significance of ARTAG is currently uncertain and awaits further studies. The goal of this proposal is to raise awareness of

  3. Capillary electrophoresis with electrospray ionisation-mass spectrometry for the characterisation of degradation products in aged papers.

    PubMed

    Dupont, Anne-Laurence; Seemann, Agathe; Lavédrine, Bertrand

    2012-01-30

    A methodology for capillary electrophoresis/electrospray ionisation mass spectrometry (CE/ESI-MS) was developed for the simultaneous analysis of degradation products from paper among two families of compounds: low molar mass aliphatic organic acids, and aromatic (phenolic and furanic) compounds. The work comprises the optimisation of the CE separation and the ESI-MS parameters for improved sensitivity with model compounds using two successive designs of experiments. The method was applied to the analysis of lignocellulosic paper at different stages of accelerated hygrothermal ageing. The compounds of interest were identified. Most of them could be quantified and several additional analytes were separated.

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

    PubMed Central

    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

  5. The Theory Behind the Age-Related Positivity Effect

    PubMed Central

    Reed, Andrew E.; Carstensen, Laura L.

    2012-01-01

    The “positivity effect” refers to an age-related trend that favors positive over negative stimuli in cognitive processing. Relative to their younger counterparts, older people attend to and remember more positive than negative information. Since the effect was initially identified and the conceptual basis articulated (Mather and Carstensen, 2005) scores of independent replications and related findings have appeared in the literature. Over the same period, a number of investigations have failed to observe age differences in the cognitive processing of emotional material. When findings are considered in theoretical context, a reliable pattern of evidence emerges that helps to refine conceptual tenets. In this article we articulate the operational definition and theoretical foundations of the positivity effect and review the empirical evidence based on studies of visual attention, memory, decision making, and neural activation. We conclude with a discussion of future research directions with emphasis on the conditions where a focus on positive information may benefit and/or impair cognitive performance in older people. PMID:23060825

  6. Rejuvenation of senescent cells-the road to postponing human aging and age-related disease?

    PubMed

    Sikora, Ewa

    2013-07-01

    Cellular senescence is the state of permanent inhibition of cell proliferation. Replicative senescence occurs due to the end replication problem and shortening telomeres with each cell division leading to DNA damage response (DDR). The number of short telomeres increases with age and age-related pathologies. Stress induced senescence, although not accompanied by attrition of telomeres, is also attributed to the DDR induced by irreparable DNA lesions in telomeric DNA. Senescent cells characterized by the presence of γH2AX, the common marker of double DNA strand breaks, and other senescence markers including activity of SA-β-gal, accumulate in tissues of aged animals and humans as well as at sites of pathology. It is believed that cellular senescence evolved as a cancer barrier since non-proliferating senescent cells cannot be transformed to neoplastic cells. On the other hand senescent cells favor cancer development, just like other age-related pathologies, by creating a low grade inflammatory state due to senescence associated secretory phenotype (SASP). Reversal/inhibition of cellular senescence could prolong healthy life span, thus many attempts have been undertaken to influence cellular senescence. The two main approaches are genetic and pharmacological/nutritional modifications of cell fate. The first one concerns cell reprogramming by induced pluripotent stem cells (iPSCs), which in vitro is effective even in cells undergoing senescence, or derived from very old or progeroid patients. The second approach concerns modification of senescence signaling pathways just like TOR-induced by pharmacological or with natural agents. However, knowing that aging is unavoidable we cannot expect its elimination, but prolonging healthy life span is a goal worth serious consideration. PMID:23064316

  7. Effects of Vitreomacular Adhesion on Age-Related Macular Degeneration

    PubMed Central

    Kang, Eui Chun; Koh, Hyoung Jun

    2015-01-01

    Herein, we review the association between vitreomacular adhesion (VMA) and neovascular age-related macular degeneration (AMD). Meta-analyses have shown that eyes with neovascular AMD are twice as likely to have VMA as normal eyes. VMA in neovascular AMD may induce inflammation, macular traction, decrease in oxygenation, sequestering of vascular endothelial growth factor (VEGF), and other cytokines or may directly stimulate VEGF production. VMA may also interfere with the treatment effects of anti-VEGF therapy, which is the standard treatment for neovascular AMD, and releasing VMA can improve the treatment response to anti-VEGF treatment in neovascular AMD. We also reviewed currently available methods of relieving VMA. PMID:26425354

  8. Age-Related Macular Degeneration: Advances in Management and Diagnosis

    PubMed Central

    Yonekawa, Yoshihiro; Miller, Joan W.; Kim, Ivana K.

    2015-01-01

    Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment in older populations in industrialized nations. AMD is a late-onset deterioration of photoreceptors and retinal pigment epithelium in the central retina caused by various environmental and genetic factors. Great strides in our understanding of AMD pathogenesis have been made in the past several decades, which have translated into revolutionary therapeutic agents in recent years. In this review, we describe the clinical and pathologic features of AMD and present an overview of current diagnosis and treatment strategies. PMID:26239130

  9. Squalamine lactate for exudative age-related macular degeneration.

    PubMed

    Connolly, Brian; Desai, Avinash; Garcia, Charles A; Thomas, Edgar; Gast, Michael J

    2006-09-01

    Squalamine lactate inhibits angiogenesis by a long-lived, intracellular mechanism of action. The drug is taken up into activated endothelial cells through caveolae, small invaginations in the cellular membrane. Subsequently, the drug binds to and "chaperones" calmodulin to an intracellular membrane compartment and blocks angiogenesis at several levels. A series of basic investigations, preclinical studies, and human clinical trials have begun to establish the proof of concept, efficacy, and safety parameters for use of squalamine lactate as a therapeutic agent for exudative age-related macular degeneration and several types of malignancies. PMID:16935213

  10. Aging-Related Geniohyoid Muscle Atrophy Is Related to Aspiration Status in Healthy Older Adults

    PubMed Central

    2013-01-01

    Background. Age-related muscle weakness due to atrophy and fatty infiltration in orofacial muscles may be related to swallowing deficits in older adults. An important component of safe swallowing is the geniohyoid (GH) muscle, which helps elevate and stabilize the hyoid bone, thus protecting the airway. This study aimed to explore whether aging and aspiration in older adults were related to GH muscle atrophy and fatty infiltration. Method. Eighty computed tomography scans of the head and neck from 40 healthy older (average age 78 years) and 40 younger adults (average age 32 years) were analyzed. Twenty aspirators and 20 nonaspirators from the 40 older adults had been identified previously. Two-dimensional views in the sagittal and coronal planes were used to measure the GH cross-sectional area and fatty infiltration. Results. GH cross-sectional area was larger in men than in women (p < .05). Decreased cross-sectional area was associated with aging (p < .05), and cross-sectional area was significantly smaller in aspirators compared with nonaspirators, but only among the older men (p < .01). Increasing fatty infiltration was associated with aging in the middle (p < .05) and posterior (p < .01) portions of the GH muscle. There was no significant difference in fatty infiltration of the GH muscle among aspirators and nonaspirators. Conclusion. GH muscle atrophy was associated with aging and aspiration. Fatty infiltration in the GH muscle was increased with aging but not related to aspiration status. These findings suggest that GH muscle atrophy may be a component of decreased swallowing safety and aspiration in older adults and warrants further investigation. PMID:23112114

  11. Nutritional Risk Factors for Age-Related Macular Degeneration

    PubMed Central

    Ersoy, Lebriz; Lechanteur, Yara T.; Hoyng, Carel B.; Kirchhof, Bernd; den Hollander, Anneke I.

    2014-01-01

    Purpose. To evaluate the role of nutritional factors, serum lipids, and lipoproteins in late age-related macular degeneration (late AMD). Methods. Intake of red meat, fruit, fish, vegetables, and alcohol, smoking status, and body mass index (BMI) were ascertained questionnaire-based in 1147 late AMD cases and 1773 controls from the European Genetic Database. Serum levels of lipids and lipoproteins were determined. The relationship between nutritional factors and late AMD was assessed using logistic regression. Based on multivariate analysis, area-under-the-curve (AUC) was calculated by receiver-operating-characteristics (ROC). Results. In a multivariate analysis, besides age and smoking, obesity (odds ratio (OR): 1.44, P = 0.014) and red meat intake (daily: OR: 2.34, P = 8.22 × 10−6; 2–6x/week: OR: 1.67, P = 7.98 × 10−5) were identified as risk factors for developing late AMD. Fruit intake showed a protective effect (daily: OR: 0.52, P = 0.005; 2–6x/week: OR: 0.58, P = 0.035). Serum lipid and lipoprotein levels showed no significant association with late AMD. ROC for nutritional factors, smoking, age, and BMI revealed an AUC of 0.781. Conclusion. Red meat intake and obesity were independently associated with increased risk for late AMD, whereas fruit intake was protective. A better understanding of nutritional risk factors is necessary for the prevention of AMD. PMID:25101280

  12. Relative Age Effect in UEFA Championship Soccer Players

    PubMed Central

    González-Víllora, Sixto; Pastor-Vicedo, Juan C.; Cordente, David

    2015-01-01

    Relative Age Effect (RAE) is the breakdown by both age grouping and dates of birth of athletes. In the past 20 years the existence of this effect has been shown with higher or smaller impact in multiple sports, including soccer. The purpose of this study was to identify the existence of RAE in European soccer players. The sample included 841 elite soccer players who were participants in the UEFA European Soccer Championship in different categories. The professional category (n = 368), U-19 (n = 144) and U-17 (n = 145) were in 2012, and U-21 was in 2011 (n = 184). The Kolmogorov-Smirnov test and the Levene test recommended the use of nonparametric statistics. The results obtained by the square test ( the Kruskal-Wallis test and Cohen’s effect sizes revealed the existence of RAE (χ2 = 17.829, p < 0.001; d = 0.30), with the size of their different effects depending on their category or qualifying round achieved by the national team and the existence of significance in the observed differences by category. Therefore, we could continue examining RAE which is present in elite soccer, and could be considered a factor that influences performance of the national teams tested. RAE was not evident in the professional teams analysed, however it was present in the three lower categories analysed (youth categories), with its influence being greater on younger age categories (U-17). PMID:26557207

  13. Aging Related Changes of Retina and Optic Nerve of Uromastyx aegyptia and Falco tinnunculus

    PubMed Central

    2013-01-01

    Aging is a biological phenomenon that involves gradual degradation of the structure and function of the retina and optic nerve. To our knowledge, little is known about the aging-related ocular cell loss in avian (Falco tinnunculus) and reptilian species (Uromastyx aegyptia). A selected 90 animals of pup, middle, and old age U. aegyptia (reptilian) and F. tinnunculus (avian) were used. The retinae and optic nerves were investigated by light and transmission electron microscopy (TEM) and assessments of neurotransmitters, antioxidant enzymes (catalase, superoxide dismustase and glutathione s transferase), caspase-3 and -7, malonadialdhyde, and DNA fragmentation. Light and TEM observations of the senile specimens revealed apparent deterioration of retinal cell layers, especially the pigmented epithelium and photoreceptor outer segments. Their inclusions of melanin were replaced by lipofuscins. Also, vacuolar degeneration and demyelination of the optic nerve axons were detected. Concomitantly, there was a marked increase of oxidative stress involved reduction of neurotransmitters and antioxidant enzymes and an increase of lipid peroxidation, caspase-3 and -7, subG0/G1 apoptosis, and P53. We conclude that aging showed an inverse relationship with the neurotransmitters and antioxidant enzymes and a linear relationship of caspases, malondialdhyde, DNA apoptosis, and P53 markers of cell death. These markers reflected the retinal cytological alterations and lipofuscin accumulation within inner segments. PMID:24215233

  14. A twin study on age-related macular degeneration.

    PubMed Central

    Meyers, S M

    1994-01-01

    A prospective twin study on age-related macular degeneration (AMD) recruited 83 monozygotic pairs, 28 dizygotic pairs, and one triplet set from 1986 through 1993. Zygosity was determined by genetic testing of red cell markers, HLA antigens, or specific DNA loci. There were no twin pairs in which I collected data on only one twin. To decrease ascertainment bias, after 1991 the recruitment notice did not mention AMD, and I did not ask about a history of eye disease before the eye examination. Because of this, twin pairs recruited from 1986 through 1991 were statistically analyzed separately from those after January 1, 1992. From 1986 through 1991, 23 twin pairs were recruited; 11 monozygotic and 2 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 9 monozygotic pairs with AMD were all concordant, and 1 dizygotic pair was discordant for basal laminar drusen. The concordance rate of AMD did not differ significantly between monozygotic and dizygotic twin pairs (P = .10) for 1986 through 1991. In 1992 and 1993, 88 twin pairs and one triplet set were recruited; 49 monozygotic and 19 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 14 monozygotic pairs with AMD were all concordant, and 2 of 7 dizygotic pairs were concordant for AMD. The nonidentical triplets (1 with and 2 without AMD) were categorized as one of the discordant dizygotic pairs in the statistical evaluation. In nontwin age-matched (within 2 or 5 years of age) or age- and sex-matched sibling pairs the concordance rate of AMD ranged from 16% to 25%. The concordance rate of AMD was significantly higher in monozygotic than in dizygotic twins (P = .001) for 1992 and 1993. The concordance rate was higher for monozygotic twin pairs recruited in 1992 and 1993 than in any of the four subsets of nontwin age-method or age- and sex-matched sibling pairs (P < .0001). Overall, from 1986 through 1993, 23 of 23 monozygotic and 2 of 8 dizygotic twin pairs were concordant for AMD

  15. Age-related changes in the Brazilian woman's smile.

    PubMed

    Correia, Luiza Nayara Almeida Lyra; Reis, Silvia Augusta Braga; Conti, Ana Claudia de Castro Ferreira; Capelozza Filho, Leopoldino; Almeida-Pedrin, Renata Rodrigues

    2016-01-01

    The aim of this research was to evaluate age-related changes in the smile of Brazilian women. The sample consisted of 249 Brazilian women who had not undergone previous orthodontic treatment or facial surgery. They were divided into four groups, according to age: G1 (20-29), G2 (30-39), G3 (40-49) and G4 (50 or older). Standardized front view photographs were taken while smiling and at rest. Measurements were evaluated by ANOVA and post-hoc Tukey. The Chi-square test was applied for qualitative variables. Upper lip thickness at rest and exposure of upper incisors on smiling decreased with age. Most individuals (60.9%) exhibited a medium smile. High smiles were more often seen in G1 (45%) and less frequently in G4 (18.8%), whereas the opposite occurred with the low smile, i.e., G4 (21.9%) and G1 (6.7%). Variations among the groups were observed in the transverse exposure of the teeth on smiling. In G1 and G3, there was a balance between tooth exposures, so that the teeth were exposed as far as the premolars and/or molars. Most of the women (56.3%) in G2 exposed their teeth as far as the first molars on smiling, whereas most of those (40.6%) in G4 exposed their teeth only as far as the first premolars on smiling. As age increased, there was decreased exposure of the upper incisors, decreased upper lip thickness and lower exposure of teeth vertically and transversely.

  16. The Age-Related Orientational Changes of Human Semicircular Canals

    PubMed Central

    Lyu, Hui-Ying; Chen, Ke-Guang; Yin, Dong-Ming; Hong, Juan; Yang, Lin; Zhang, Tian-Yu; Dai, Pei-Dong

    2016-01-01

    Objectives Some changes are found in the labyrinth anatomy during postnatal development. Although the spatial orientation of semicircular canals was thought to be stable after birth, we investigated the age-related orientational changes of human semicircular canals during development. Methods We retrospectively studied the computed tomography (CT) images of both ears of 76 subjects ranged from 1 to 70 years old. They were divided into 4 groups: group A (1–6 years), group B (7–12 years), group C (13–18 years), and group D (>18 years). The anatomical landmarks of the inner ear structures were determined from CT images. Their coordinates were imported into MATLAB software for calculating the semicircular canals orientation, angles between semicircular canal planes and the jugular bulb (JB) position. Differences between age groups were analyzed using multivariate statistics. Relationships between variables were analyzed using Pearson analysis. Results The angle between the anterior semicircular canal plane and the coronal plane, and the angle between the horizontal semicircular canal plane and the coronal plane were smaller in group D than those in group A (P<0.05). The JB position, especially the anteroposterior position of right JB, correlated to the semicircular canals orientation (P<0.05). However, no statistically significant differences in the angles between ipsilateral canal planes among different age groups were found. Conclusion The semicircular canals had tendencies to tilt anteriorly simultaneously as a whole with age. The JB position correlated to the spatial arrangement of semicircular canals, especially the right JB. Our calculation method helps detect developmental and pathological changes in vestibular anatomy. PMID:27090280

  17. Effects of the benzoxazolinone BOA, selected degradation products and structure related pesticides on soil organisms.

    PubMed

    Coja, Tamara; Idinger, Jacqueline; Blümel, Sylvia

    2006-02-01

    The benzoxazolinone BOA and the degradation products APO, AAPO and HPAA, as well as four structure related compounds to BOA, were tested for their lethal and sublethal effects on the collembola Folsomia candida and on the carabid beetle Poecilus cupreus applying validated standard laboratory methods. According to the results of the recommended risk assessment for plant protection products (EPPO, 2003), BOA and its structure related compounds carbendazim, benoxacor and benazolin (and additionally the formulated product Cresopur) were classified as low risk compounds for both test organisms. Phosalone was of high risk for F. candida. APO, AAPO and HPAA were of medium risk for F. candida, but were rated as low risk compounds for P. cupreus at the tested rates of about 2 mg/kg substrate. However, as the BOA degradation products have been found to occur at field rates below 0.2 mg/kg substrate or are often even not detectable, it is assumed that their potential risk for both non-target soil organisms in the field will be acceptable.

  18. Material Degradation during Isothermal Aging and Thermal Cycling of Hybrid Mica Seal with Ag Interlayer under SOFC Exposure Conditions

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.; Hardy, John S.; Singh, Prabhakar

    2006-11-01

    Hybrid phlogopite mica seals with silver interlayers were evaluated in terms of materials degradation in a combined isothermal ageing and thermal cycling test. The hybrid mica seal was composed of a phlogopite mica paper sandwiched between two Ag foils. The hybrid micas were first aged at 800oC for ~1,000 hrs in a moist, dilute hydrogen fuel (~2.7% H2/bal. Ar + ~3% H2O), followed by short-term thermal cycling between ~100oC and 800oC. The combined test was repeated for 3 times for a total of 4,000 hrs ageing at 800oC and 119 thermal cycles. The results of high temperature leak rate tests showed very good thermal stability and thermal cycle stability with 800oC leak rates of ~0.02-0.03 sccm/cm. A hybrid mica seal tested in a high water content fuel (30 v% H2O/70 v% H2) demonstrated similar leakage during isothermal ageing and subsequent thermal cycles. Post-mortem analyses showed no extensive reaction between Ag and phlogopite mica as well as no significant mica degradation. Simple calculations to estimate the effect of measured leakage on the open circuit voltage and the total fuel loss for various SOFC stack sizes suggest very small fuel losses for the current hybrid mica seals, indicating that they are good candidates for SOFC sealing applications. Corresponding author: Yeong-Shyung Chou Tel: 509-375-2527, Fax: 509-375-2186, E-mail: yeong-shyung.chou@pnl.gov

  19. Sex- and age-related differences in mathematics.

    PubMed

    Rustemeyer, Ruth; Fischer, Natalie

    2005-08-01

    This study examined sex differences and age-related changes in mathematics based on Eccles's 1985 expectancy-value model of "achievement-related choices" and Dweck's 1986 motivation-process model. We have assessed motivational variables and performance in mathematics for youth in Grades 5, 7, and 9 in a German comprehensive secondary school. Significant sex differences in Grades 7 and 9 were observed even when school marks were controlled for. Furthermore, the results indicated differences between Grade 7 and Grade 9 on most of the motivational variables. Older students show a less favorable motivational pattern. Our results give evidence of the importance of motivational encouragement in mathematics classes, especially for girls and low achieving learners. PMID:16279324

  20. The role of DNA methylation in aging, rejuvenation, and age-related disease.

    PubMed

    Johnson, Adiv A; Akman, Kemal; Calimport, Stuart R G; Wuttke, Daniel; Stolzing, Alexandra; de Magalhães, João Pedro

    2012-10-01

    DNA methylation is a major control program that modulates gene expression in a plethora of organisms. Gene silencing through methylation occurs through the activity of DNA methyltransferases, enzymes that transfer a methyl group from S-adenosyl-L-methionine to the carbon 5 position of cytosine. DNA methylation patterns are established by the de novo DNA methyltransferases (DNMTs) DNMT3A and DNMT3B and are subsequently maintained by DNMT1. Aging and age-related diseases include defined changes in 5-methylcytosine content and are generally characterized by genome-wide hypomethylation and promoter-specific hypermethylation. These changes in the epigenetic landscape represent potential disease biomarkers and are thought to contribute to age-related pathologies, such as cancer, osteoarthritis, and neurodegeneration. Some diseases, such as a hereditary form of sensory neuropathy accompanied by dementia, are directly caused by methylomic changes. Epigenetic modifications, however, are reversible and are therefore a prime target for therapeutic intervention. Numerous drugs that specifically target DNMTs are being tested in ongoing clinical trials for a variety of cancers, and data from finished trials demonstrate that some, such as 5-azacytidine, may even be superior to standard care. DNMTs, demethylases, and associated partners are dynamically shaping the methylome and demonstrate great promise with regard to rejuvenation.

  1. The Role of DNA Methylation in Aging, Rejuvenation, and Age-Related Disease

    PubMed Central

    Johnson, Adiv A.; Akman, Kemal; Calimport, Stuart R.G.; Wuttke, Daniel; de Magalhães, João Pedro

    2012-01-01

    Abstract DNA methylation is a major control program that modulates gene expression in a plethora of organisms. Gene silencing through methylation occurs through the activity of DNA methyltransferases, enzymes that transfer a methyl group from S-adenosyl-l-methionine to the carbon 5 position of cytosine. DNA methylation patterns are established by the de novo DNA methyltransferases (DNMTs) DNMT3A and DNMT3B and are subsequently maintained by DNMT1. Aging and age-related diseases include defined changes in 5-methylcytosine content and are generally characterized by genome-wide hypomethylation and promoter-specific hypermethylation. These changes in the epigenetic landscape represent potential disease biomarkers and are thought to contribute to age-related pathologies, such as cancer, osteoarthritis, and neurodegeneration. Some diseases, such as a hereditary form of sensory neuropathy accompanied by dementia, are directly caused by methylomic changes. Epigenetic modifications, however, are reversible and are therefore a prime target for therapeutic intervention. Numerous drugs that specifically target DNMTs are being tested in ongoing clinical trials for a variety of cancers, and data from finished trials demonstrate that some, such as 5-azacytidine, may even be superior to standard care. DNMTs, demethylases, and associated partners are dynamically shaping the methylome and demonstrate great promise with regard to rejuvenation. PMID:23098078

  2. Progress on retinal image analysis for age related macular degeneration.

    PubMed

    Kanagasingam, Yogesan; Bhuiyan, Alauddin; Abràmoff, Michael D; Smith, R Theodore; Goldschmidt, Leonard; Wong, Tien Y

    2014-01-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss in those over the age of 50 years in the developed countries. The number is expected to increase by ∼1.5 fold over the next ten years due to an increase in aging population. One of the main measures of AMD severity is the analysis of drusen, pigmentary abnormalities, geographic atrophy (GA) and choroidal neovascularization (CNV) from imaging based on color fundus photograph, optical coherence tomography (OCT) and other imaging modalities. Each of these imaging modalities has strengths and weaknesses for extracting individual AMD pathology and different imaging techniques are used in combination for capturing and/or quantification of different pathologies. Current dry AMD treatments cannot cure or reverse vision loss. However, the Age-Related Eye Disease Study (AREDS) showed that specific anti-oxidant vitamin supplementation reduces the risk of progression from intermediate stages (defined as the presence of either many medium-sized drusen or one or more large drusen) to late AMD which allows for preventative strategies in properly identified patients. Thus identification of people with early stage AMD is important to design and implement preventative strategies for late AMD, and determine their cost-effectiveness. A mass screening facility with teleophthalmology or telemedicine in combination with computer-aided analysis for large rural-based communities may identify more individuals suitable for early stage AMD prevention. In this review, we discuss different imaging modalities that are currently being considered or used for screening AMD. In addition, we look into various automated and semi-automated computer-aided grading systems and related retinal image analysis techniques for drusen, geographic atrophy and choroidal neovascularization detection and/or quantification for measurement of AMD severity using these imaging modalities. We also review the existing telemedicine studies which

  3. The Relative Age Effect and Its Influence on Academic Performance

    PubMed Central

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

    2015-01-01

    Introduction and Purpose 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. Methods 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. Results 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

  4. Age-related decline in bottom-up processing and selective attention in the very old.

    PubMed

    Zhuravleva, Tatyana Y; Alperin, Brittany R; Haring, Anna E; Rentz, Dorene M; Holcomb, Philip J; Daffner, Kirk R

    2014-06-01

    Previous research demonstrating age-related deficits in selective attention have not included old-old adults, an increasingly important group to study. The current investigation compared event-related potentials in 15 young-old (65-79 years old) and 23 old-old (80-99 years old) subjects during a color-selective attention task. Subjects responded to target letters in a specified color (Attend) while ignoring letters in a different color (Ignore) under both low and high loads. There were no group differences in visual acuity, accuracy, reaction time, or latency of early event-related potential components. The old-old group showed a disruption in bottom-up processing, indexed by a substantially diminished posterior N1 (smaller amplitude). They also demonstrated markedly decreased modulation of bottom-up processing based on selected visual features, indexed by the posterior selection negativity (SN), with similar attenuation under both loads. In contrast, there were no group differences in frontally mediated attentional selection, measured by the anterior selection positivity (SP). There was a robust inverse relationship between the size of the SN and SP (the smaller the SN, the larger the SP), which may represent an anteriorly supported compensatory mechanism. In the absence of a decline in top-down modulation indexed by the SP, the diminished SN may reflect age-related degradation of early bottom-up visual processing in old-old adults.

  5. Age-related vascular stiffening: causes and consequences

    PubMed Central

    Kohn, Julie C.; Lampi, Marsha C.; Reinhart-King, Cynthia A.

    2015-01-01

    Arterial stiffening occurs with age and is closely associated with the progression of cardiovascular disease. Stiffening is most often studied at the level of the whole vessel because increased stiffness of the large arteries can impose increased strain on the heart leading to heart failure. Interestingly, however, recent evidence suggests that the impact of increased vessel stiffening extends beyond the tissue scale and can also have deleterious microscale effects on cellular function. Altered extracellular matrix (ECM) architecture has been recognized as a key component of the pre-atherogenic state. Here, the underlying causes of age-related vessel stiffening are discussed, focusing on age-related crosslinking of the ECM proteins as well as through increased matrix deposition. Methods to measure vessel stiffening at both the macro- and microscale are described, spanning from the pulse wave velocity measurements performed clinically to microscale measurements performed largely in research laboratories. Additionally, recent work investigating how arterial stiffness and the changes in the ECM associated with stiffening contributed to endothelial dysfunction will be reviewed. We will highlight how changes in ECM protein composition contribute to atherosclerosis in the vessel wall. Lastly, we will discuss very recent work that demonstrates endothelial cells (ECs) are mechano-sensitive to arterial stiffening, where changes in stiffness can directly impact EC health. Overall, recent studies suggest that stiffening is an important clinical target not only because of potential deleterious effects on the heart but also because it promotes cellular level dysfunction in the vessel wall, contributing to a pathological atherosclerotic state. PMID:25926844

  6. Genetic risk factors and age-related macular degeneration (AMD)

    PubMed Central

    Mousavi, Maryam; Armstrong, Richard A.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of blindness in individuals older than 65 years of age. It is a multifactorial disorder and identification of risk factors enables individuals to make lifestyle choices that may reduce the risk of disease. Collaboration between geneticists, ophthalmologists, and optometrists suggests that genetic risk factors play a more significant role in AMD than previously thought. The most important genes are associated with immune system modulation and the complement system, e.g., complement factor H (CFH), factor B (CFB), factor C3, and serpin peptidase inhibitor (SERPING1). Genes associated with membrane transport, e.g., ATP-binding cassette protein (ABCR) and voltage-dependent calcium channel gamma 3 (CACNG3), the vascular system, e.g., fibroblast growth factor 2 (FGF2), fibulin-5, lysyl oxidase-like gene (LOXL1) and selectin-P (SELP), and with lipid metabolism, e.g., apolipoprotein E (APOE) and hepatic lipase (LIPC) have also been implicated. In addition, several other genes exhibit some statistical association with AMD, e.g., age-related maculopathy susceptibility protein 2 (ARMS2) and DNA excision repair protein gene (ERCC6) but more research is needed to establish their significance. Modifiable risk factors for AMD should be discussed with patients whose lifestyle and/or family history place them in an increased risk category. Furthermore, calculation of AMD risk using current models should be recommended as a tool for patient education. It is likely that AMD management in future will be increasingly influenced by assessment of genetic risk as such screening methods become more widely available.

  7. Age-Related Macular Degeneration: A Scientometric Analysis

    PubMed Central

    Ramin, Shahrokh; Soheilian, Masoud; Habibi, Gholamreza; Ghazavi, Roghayeh; Gharebaghi, Reza; Heidary, Fatemeh

    2015-01-01

    Age-related macular degeneration (ARMD) is a major cause of central blindness among working aged adults across the world. Systematic research planning on any subject, including ARMD is in need of solid data regarding previous efforts in this field and to identify the gaps in the research. This study aimed to elucidate the most important trends, directions, and gap in this subject. The data extracted from the Institute for Scientific Information were used to perform a bibliometric analysis of the scientific productions (1993–2013) about ARMD. Specific parameters related to ARMD were analyzed to obtain a view of the topic’s structure, history, and document relationships. Additionally, the trends and authors in the most influential publications were analyzed. The number of articles in this field was found constantly increasing. Most highly cited articles addressed genetic epidemiology and clinical research topics in this field. During the past 3 years, there has been a trend toward biomarker research. Through performing the first scientometric survey on ARMD research, we analyzed the characteristics of papers and the trends in scientific production. We also identified some of the critical gaps in the current research efforts that would help in large-scale research strategic planning. PMID:26060829

  8. Age-related neural changes in autobiographical remembering and imagining.

    PubMed

    Addis, Donna Rose; Roberts, Reece P; Schacter, Daniel L

    2011-11-01

    Numerous neuroimaging studies have revealed that in young adults, remembering the past and imagining the future engage a common core network. Although it has been observed that older adults engage a similar network during these tasks, it is unclear whether or not they activate this network in a similar manner to young adults. Young and older participants completed two autobiographical tasks (imagining future events and recalling past events) in addition to a semantic-visuospatial control task. Spatiotemporal Partial Least Squares analyses examined whole brain patterns of activity across both the construction and elaboration of autobiographical events. These analyses revealed that that both age groups activated a similar network during the autobiographical tasks. However, some key age-related differences in the activation of this network emerged. During the construction of autobiographical events, older adults showed less activation relative to younger adults, in regions supporting episodic detail such as the medial temporal lobes and the precuneus. Later in the trial, older adults showed differential recruitment of medial and lateral temporal regions supporting the elaboration of autobiographical events, and possibly reflecting an increased role of conceptual information when older adults describe their pasts and their futures.

  9. Current therapeutic developments in atrophic age-related macular degeneration.

    PubMed

    Hanus, Jakub; Zhao, Fangkun; Wang, Shusheng

    2016-01-01

    Age-related macular degeneration (AMD), a degenerative disorder of the central retina, is the leading cause of irreversible blindness in the elderly. The underlying mechanism of the advanced form of dry AMD, also named geographic atrophy (GA) or atrophic AMD, remains unclear. Consequently, no cure is available for dry AMD or GA. The only prevention option currently available is the Age-Related Eye Disease Study (AREDS) formulation, which has been demonstrated to slow down the progression of dry AMD. This review summarises recent advances in therapy for dry AMD and GA. Building on the new understanding of the disease and recent technological breakthroughs, numerous ongoing clinical trials have the goal of meeting the need to cure AMD. Therapeutic agents are being developed to target the key features of the disease, including inhibiting the complement pathway and other inflammatory pathways, reducing oxidative stress and protecting retinal pigment epithelial (RPE) cells, inhibiting lipofuscin and visual cycle, regenerating RPE cells from stem cells and restoring choroidal blood flow. Some of these therapeutic options, especially the stem cell-based therapy, hold great promise, which brings great hope for this devastating blinding disease. PMID:26553922

  10. Age-Related Macular Degeneration: A Scientometric Analysis.

    PubMed

    Ramin, Shahrokh; Soheilian, Masoud; Habibi, Gholamreza; Ghazavi, Roghayeh; Gharebaghi, Reza; Heidary, Fatemeh

    2015-01-01

    Age-related macular degeneration (ARMD) is a major cause of central blindness among working aged adults across the world. Systematic research planning on any subject, including ARMD is in need of solid data regarding previous efforts in this field and to identify the gaps in the research. This study aimed to elucidate the most important trends, directions, and gap in this subject. The data extracted from the Institute for Scientific Information were used to perform a bibliometric analysis of the scientific productions (1993-2013) about ARMD. Specific parameters related to ARMD were analyzed to obtain a view of the topic's structure, history, and document relationships. Additionally, the trends and authors in the most influential publications were analyzed. The number of articles in this field was found constantly increasing. Most highly cited articles addressed genetic epidemiology and clinical research topics in this field. During the past 3 years, there has been a trend toward biomarker research. Through performing the first scientometric survey on ARMD research, we analyzed the characteristics of papers and the trends in scientific production. We also identified some of the critical gaps in the current research efforts that would help in large-scale research strategic planning. PMID:26060829

  11. Age-Related Macular Degeneration: A Scientometric Analysis.

    PubMed

    Ramin, Shahrokh; Soheilian, Masoud; Habibi, Gholamreza; Ghazavi, Roghayeh; Gharebaghi, Reza; Heidary, Fatemeh

    2015-01-01

    Age-related macular degeneration (ARMD) is a major cause of central blindness among working aged adults across the world. Systematic research planning on any subject, including ARMD is in need of solid data regarding previous efforts in this field and to identify the gaps in the research. This study aimed to elucidate the most important trends, directions, and gap in this subject. The data extracted from the Institute for Scientific Information were used to perform a bibliometric analysis of the scientific productions (1993-2013) about ARMD. Specific parameters related to ARMD were analyzed to obtain a view of the topic's structure, history, and document relationships. Additionally, the trends and authors in the most influential publications were analyzed. The number of articles in this field was found constantly increasing. Most highly cited articles addressed genetic epidemiology and clinical research topics in this field. During the past 3 years, there has been a trend toward biomarker research. Through performing the first scientometric survey on ARMD research, we analyzed the characteristics of papers and the trends in scientific production. We also identified some of the critical gaps in the current research efforts that would help in large-scale research strategic planning.

  12. Current Therapeutic Development for Atrophic Age-related Macular Degeneration

    PubMed Central

    Hanus, Jakub; Zhao, Fangkun; Wang, Shusheng

    2016-01-01

    Age-related macular degeneration (AMD), a degenerative disorder of the central retina, is the leading cause of irreversible blindness in the elderly. The underlying mechanism of the advanced form of dry AMD, also named geographic atrophy (GA) or atrophic AMD, remains unclear. Consequently, no cure is available for dry AMD or GA. The only prevention option currently available is the Age Related Eye Disease Study (AREDS) formulation which has been demonstrated to slow down the progression of dry AMD. This review summarizes recent advances in therapy for dry AMD and GA. Building on the new understanding of the disease and recent technological breakthroughs, numerous ongoing clinical trials have the goal of meeting the need to cure AMD. Therapeutic agents are being developed to target the key features of the disease, including inhibiting the complement pathway and other inflammatory pathways, reducing oxidative stress and protecting retinal pigment epithelial (RPE) cells, inhibiting lipofuscin and visual cycle, regenerating RPE cells from stem cells and restoring choroidal blood flow. Some of these therapeutic options, especially the stem-cell based therapy, hold great promise, which brings great hope for this devastating blinding disease. PMID:26553922

  13. Age-Related Changes in Demand–Withdraw Communication Behaviors

    PubMed Central

    Holley, Sarah R.; Haase, Claudia M.; Levenson, Robert W.

    2013-01-01

    Demand–withdraw communication is a set of conflict-related behaviors in which one partner blames or pressures while the other partner withdraws or avoids. The present study examined age-related changes in these behaviors longitudinally over the course of later life stages. One hundred twenty-seven middle-aged and older long-term married couples were observed at 3 time points across 13 years as they engaged in a conversation about an area of relationship conflict. Husbands’ and wives’ demand–withdraw behaviors (i.e., blame, pressure, withdrawal, avoidance) were objectively rated by trained coders at each time point. Data were analyzed using dyad-level latent growth curve models in a structural equation modeling framework. For both husbands and wives, the results showed a longitudinal pattern of increasing avoidance behavior over time and stability in all other demand and withdraw behaviors. This study supports the notion that there is an important developmental shift in the way that conflict is handled in later life. PMID:23913982

  14. Age-related and death-related differences in emotional complexity.

    PubMed

    Palgi, Yuval; Shrira, Amit; Ben-Ezra, Menachem; Spalter, Tal; Kavé, Gitit; Shmotkin, Dov

    2014-06-01

    The present study aimed to examine an aspect of emotional complexity as seen in covariation between retrospective judgments of positive and negative affects. We assume that individuals can experience positive affect independently of negative affect. Theories argue that emotional complexity increases in old age, but research shows mixed evidence. Additionally, emotional complexity has been shown to decrease in situations prevalent in old age, such as physical illness and disability. Integrating distinct effects of age and distance to death, we propose that emotional complexity may remain intact or even increase in old age, and yet it decreases in light of functional deterioration shortly before death. The current research examined whether emotional complexity decreases as a function of subjective perception of closeness to death (subjective survival probability) or actual closeness to death. We used 3 large-scale databases: 2 cross-sectional (SHARE, N = 17,437, mean age = 64; HRS, N = 6,032, mean age = 67) and 1 longitudinal (CALAS, N = 1,310, mean age at baseline = 83). Hierarchical multiple regressions and multilevel models showed that respondents who perceived themselves as closer to death or were actually closer to death showed lower emotional complexity (a stronger negative correlation between positive and negative affects). Age and emotional complexity were unrelated or positively related, depending on the sample. Findings remained the same after controlling for demographic characteristics, as well as physical and cognitive functioning. The results indicate that both subjective and objective closeness to death are associated with lower emotional complexity. This death-related decrease in emotional complexity is discussed within current theories of aging.

  15. Effect of UV aging on degradation of Ethylene-vinyl Acetate (EVA) as encapsulant in photovoltaic (PV) modules

    NASA Astrophysics Data System (ADS)

    Badiee, Amir; Wildman, Ricky; Ashcroft, Ian

    2014-10-01

    A lifetime of 20-30 years is generally regarded as necessary for photovoltaic modules to achieve economic break even. As a consequence, understanding how to improve the durability and reliability of the modules is becoming a necessity. Photovoltaic modules are exposed to extremely harsh conditions of heat, humidity, and ultraviolet (UV) radiation which affect the properties of the encapsulant material and cause yellowing, delamination and degradation of the material, which knock on effects on the performance and the long-term reliability of photovoltaic modules. This study addresses the impact of UV on the photochemical degradation of Ethylene-vinyl Acetate (EVA). Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance (FTIR-ATR) mode was performed on aged samples. The samples were exposed to UV light from a xenon lamp at 0.68 W/m2 at 340 nm with exposure up to 1000 hours. The FTIR-ATR measurement shows significant changes in the absorption at 1740 cm-1, 1720 cm-1 and 910 cm-1 which correspond to acetate, carboxylic acid and vinyl group respectively. It is shown that the UV exposure is the most significant aging factor. The rate of the photooxidation of EVA is compared by measuring the changes of absorbance at 1720 cm-1 with the UV irradiation time.

  16. Inspection Time and Cognitive Abilities in Twins Aged 7 to 17 Years: Age-Related Changes, Heritability and Genetic Covariance

    ERIC Educational Resources Information Center

    Edmonds, Caroline J.; Isaacs, Elizabeth B.; Visscher, Peter M.; Rogers, Mary; Lanigan, Julie; Singhal, Atul; Lucas, Alan; Gringras, Paul; Denton, Jane; Deary, Ian J.

    2008-01-01

    We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

  17. Degradation of mechanical properties of stainless steel cladding due to neutron irradiation and thermal aging

    SciTech Connect

    Haggag, F.M.

    1994-09-01

    Thermal aging of three-wire series-arc stainless steel weld overlay cladding at 288{degrees}C for 1605 h resulted in an appreciable decrease (16%) in the Charpy V-notch (CVN) upper-shelf energy (USE), but the effect on the 41-J transition temperature shift was very small (3{degrees}C). The combined effect following neutron irradiation at 288{degrees}C to a fluence of 5 X 10{sup 19} neutrons/cm{sup 2} (>1 MeV) was a 22% reduction in the USE and a 29{degrees}C shift in the 41-J transition temperature. The effect of thermal aging on tensile properties was very small. However, the combined effect of irradiation and aging was an increase in the yield strength (6 to 34% at test temperatures from 288 to -125{degrees}C) and no apparent change in ultimate tensile strength or total elongation. Neutron irradiation reduced the initiation fracture toughness (J{sub {kappa}}) much more than did thermal aging alone. However, irradiation slightly decreased the tearing modulus but no reduction was caused by thermal aging alone. The effects of long-term thermal exposure times (20,000 and 50,000 h) will be investigated when the specimens become available. Also, long-term thermal exposure of the three-wire cladding as well as type 308 stainless steel weld materials at 343{degrees}C is in progress.

  18. Applications and extensions of degradation modeling

    SciTech Connect

    Hsu, F.; Subudhi, M.; Samanta, P.K. ); Vesely, W.E. )

    1991-01-01

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.

  19. Applications and extensions of degradation modeling

    SciTech Connect

    Hsu, F.; Subudhi, M.; Samanta, P.K.; Vesely, W.E.

    1991-12-31

    Component degradation modeling being developed to understand the aging process can have many applications with potential advantages. Previous work has focused on developing the basic concepts and mathematical development of a simple degradation model. Using this simple model, times of degradations and failures occurrences were analyzed for standby components to detect indications of aging and to infer the effectiveness of maintenance in preventing age-related degradations from transforming to failures. Degradation modeling approaches can have broader applications in aging studies and in this paper, we discuss some of the extensions and applications of degradation modeling. The application and extension of degradation modeling approaches, presented in this paper, cover two aspects: (1) application to a continuously operating component, and (2) extension of the approach to analyze degradation-failure rate relationship. The application of the modeling approach to a continuously operating component (namely, air compressors) shows the usefulness of this approach in studying aging effects and the role of maintenance in this type component. In this case, aging effects in air compressors are demonstrated by the increase in both the degradation and failure rate and the faster increase in the failure rate compared to the degradation rate shows the ineffectiveness of the existing maintenance practices. Degradation-failure rate relationship was analyzed using data from residual heat removal system pumps. A simple linear model with a time-lag between these two parameters was studied. The application in this case showed a time-lag of 2 years for degradations to affect failure occurrences. 2 refs.

  20. Age-Related Differences in Judgments of Inappropriate Behavior are Related to Humor Style Preferences

    PubMed Central

    Stanley, Jennifer Tehan; Lohani, Monika; Isaacowitz, Derek M.

    2014-01-01

    Identifying social gaffes is important for maintaining relationships. Older adults are less able than young to discriminate between socially appropriate and inappropriate behavior in video clips. One open question is how these social appropriateness ratings relate to potential age differences in the perception of what is actually funny or not. In the present study, young, middle-aged, and older adults were equally able to discriminate between appropriate and inappropriate social behavior in a diverse set of clips relevant to both age groups. However, young and middle-aged adults rated the gaffe clips as funnier than control clips and young adults smiled more during the inappropriate clips than the control clips. Older adults did not show this pattern, suggesting that they did not find the inappropriate clips funny. Additionally, young adults endorsed a more aggressive humor style than middle-aged and older adults and aggressive humor style endorsement mediated age differences in social appropriateness ratings. Results are discussed in terms of possible mechanisms such as cohort differences in humor and developmental prioritization of certain humor styles, as well as the importance of investigating age differences in both abilities and preferences. PMID:25244473

  1. Age-related differences in judgments of inappropriate behavior are related to humor style preferences.

    PubMed

    Stanley, Jennifer Tehan; Lohani, Monika; Isaacowitz, Derek M

    2014-09-01

    Identifying social gaffes is important for maintaining relationships. Older adults are less able than young to discriminate between socially appropriate and inappropriate behavior in video clips. One open question is how these social appropriateness ratings relate to potential age differences in the perception of what is actually funny or not. In the present study, young, middle-aged, and older adults were equally able to discriminate between appropriate and inappropriate social behavior in a diverse set of clips relevant across age groups. However, young and middle-aged adults rated the gaffe clips as funnier than control clips and young adults smiled more during the inappropriate clips than the control clips. Older adults did not show this pattern, suggesting that they did not find the inappropriate clips funny. Additionally, young adults endorsed a more aggressive humor style than middle-aged and older adults and aggressive humor style endorsement mediated age differences in social appropriateness ratings. Results are discussed in terms of possible mechanisms such as cohort differences in humor and developmental prioritization of certain humor styles, as well as the importance of investigating age differences in both abilities and preferences. PMID:25244473

  2. Xanthine degradation and related enzyme activities in leaves and fruits of two coffea species differing in caffeine catabolism.

    PubMed

    Vitória, A P; Mazzafera, P

    1999-05-01

    The degradation of xanthine was studied in young and aged leaves and in immature and mature fruits of Coffea arabica and Coffea dewevrei, which differ with respect to caffeine catabolism. Radioisotope feeding experiments showed that leaves degraded xanthine more readily than fruits but that mature fruits and aged leaves were less efficient than younger tissues. In all cases, a significant part of the recovered radioactivity was in the ureides. Xanthine dehydrogenase was characterized as the enzyme responsible for xanthine degradation, and its activity and that of uricase were consistent with the results obtained in the radioisotope feeding experiments. Activities of allantoinase and allantoate amidohydrolase could not be detected. Considerable levels of endogenous allantoin and allantoic acid were found in fruits and leaves. Therefore, ureide accumulation might be a consequence of low enzyme activity. There was no positive correlation between urease activity and the data from the radioisotope feeding experiments.

  3. Effects of aging on P300 between late young-age and early middle-age adulthood: an electroencephalogram event-related potential study.

    PubMed

    Bourisly, Ali K

    2016-09-28

    The aim of this study was to identify age-related changes of P300 peak amplitude and P300 latency between closely separated nonsenile age groups (late young-aged adults and early middle-aged adults) and to investigate whether or not P300 has the potential to be used as a measure of cognitive aging even among nonsenile age groups. Twenty-eight adults (25-55 years old) completed an event-related potential oddball task. The elicitation of both P300 peak amplitude and P300 latency indicated age-related changes of P300. The results of the study showed that the P300 target peak amplitude was significantly larger in late young age compared with early middle age and that P300 target latency was also significantly delayed in early middle age compared with late young age. The results of this work contribute toward research efforts on a consensus on how aging affects event-related potential and/or P300. The main conclusions are that there exist significant age-related P300 changes even between closely separated, relatively younger, and nonsenile age groups, and that P300 has the potential to be used as a measure for cognitive aging even in nonsenile adults.

  4. Relating Age Change and Behavior to Job Requirements.

    ERIC Educational Resources Information Center

    Schaie, K. Warner

    The Age Discrimination in Employment Act has been amended to outlaw mandatory retirement at any age. However, the act permits employers to impose a specific retirement age if there is a bona fide occupational qualification (BFOQ) which cannot be met by all or most individuals. Imposition of BFOQ mandatory retirement ages by employers has led to…

  5. Varying relative degradation rates of oil in different forms and environments revealed by ramped pyrolysis.

    PubMed

    Pendergraft, Matthew A; Rosenheim, Brad E

    2014-09-16

    Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon ((13)C) and radiocarbon ((14)C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil. PMID:25105342

  6. Varying relative degradation rates of oil in different forms and environments revealed by ramped pyrolysis.

    PubMed

    Pendergraft, Matthew A; Rosenheim, Brad E

    2014-09-16

    Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon ((13)C) and radiocarbon ((14)C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil.

  7. Age-Related Susceptibility of Turkeys to Enteric Viruses.

    PubMed

    Awe, Olusegun O; Kang, Kyung-il; Ibrahim, Mahmoud; Ali, Ahmed; Elaish, Mohamed; Saif, Yehia M; Lee, Chang-Won

    2015-06-01

    Several different enteric viruses have been identified as the causes of gastrointestinal infections in poultry. Enteric virus infections are well characterized in poults, but limited studies have been conducted in older birds. The susceptibility of 2-, 7-, 12-, 30-, and 52-wk-old turkeys to turkey coronavirus (TCoV) and turkey astrovirus (TAstV) was evaluated, as well as the effect of combined infection of TAstV and TCoV in 2-wk-old poults and turkey hens. From cloacal swabs and intestines, TCoV was consistently detected by reverse transcriptase-PCR throughout the experimental period (1-21 days postinoculation [DPI]) from all age groups. In contrast, the last detection point of TAstV gradually decreased to 21, 16, and 12 DPI in birds inoculated at 2, 7, and 12 wk of age, respectively, and viral RNA was rarely detected from cloacal swabs or intestinal contents in turkey hens within 3 DPI. Infection with TAstV alone did not affect body weight in poults or egg production in hens. The combined infection of TAstV and TCoV did not induce more severe clinical signs and pathology than the TCoV infection alone. However, a severe prolonged decrease in egg production (about 50%) was observed in turkey hens in the combined infection group compared with a transient egg production drop in the TCoV-infected hens alone. The underlying mechanism regarding the age-related TAstV susceptibility and the pathogenesis of the TAstV and TCoV coinfection in layer hens needs to be further elucidated. PMID:26473670

  8. Factors Associated With Age-related Hearing Impairment

    PubMed Central

    Moon, Il Joon; Byun, Hayoung; Woo, Sook-young; Gwak, Geum-Youn; Hong, Sung Hwa; Chung, Won-Ho; Cho, Yang-Sun

    2015-01-01

    Abstract Age-related hearing impairment (ARHI) is a complex degenerative disease in the elderly. As multiple factors interact during the development of ARHI, it is important to elucidate the major influencing factors to understand and prevent ARHI. We aimed to identify risk factors associated with the development of ARHI with a retrospective cohort from 2001 to 2010. The records of the adult subjects over 40 years of age who consecutively underwent a comprehensive health checkup including pure-tone audiometry at the Health Promotion Center were reviewed. During this period, 1560 subjects who underwent pure-tone audiometry more than twice, had no other otologic diseases, and were followed-up more than 2 years were included. A pure-tone average (PTA: 0.5, 1, 2, 4 kHz) was calculated. Development of ARHI was defined as a PTA at follow-up more than 10 dB greater than the baseline PTA. Times to the first development of ARHI were investigated. Overall, 12.7% of subjects developed ARHI within the first 4 years. High blood ionized calcium (hazard ratio [HR] 0.084), albumin (HR 0.239), systolic blood pressure (HR 0.577), thyroid hormone (T3) (HR 0.593), and alpha fetoprotein levels (HR 0.883) were associated with decreased hazard for the development of ARHI. In contrast, high blood high-density lipoprotein (HR 2.105), uric acid (HR 1.684), total protein (HR 1.423), and total bilirubin levels (HR 1.220) were potential risk factors for the development of ARHI. Development of ARHI is common among the aged population, and a variety of factors may interact during this process. The results of this study can be used for counseling of adults at high-risk of developing ARHI with regard to regular audiological check-up. PMID:26512592

  9. Metabolomics of human brain aging and age-related neurodegenerative diseases.

    PubMed

    Jové, Mariona; Portero-Otín, Manuel; Naudí, Alba; Ferrer, Isidre; Pamplona, Reinald

    2014-07-01

    Neurons in the mature human central nervous system (CNS) perform a wide range of motor, sensory, regulatory, behavioral, and cognitive functions. Such diverse functional output requires a great diversity of CNS neuronal and non-neuronal populations. Metabolomics encompasses the study of the complete set of metabolites/low-molecular-weight intermediates (metabolome), which are context-dependent and vary according to the physiology, developmental state, or pathologic state of the cell, tissue, organ, or organism. Therefore, the use of metabolomics can help to unravel the diversity-and to disclose the specificity-of metabolic traits and their alterations in the brain and in fluids such as cerebrospinal fluid and plasma, thus helping to uncover potential biomarkers of aging and neurodegenerative diseases. Here, we review the current applications of metabolomics in studies of CNS aging and certain age-related neurodegenerative diseases such as Alzheimer disease, Parkinson disease, and amyotrophic lateral sclerosis. Neurometabolomics will increase knowledge of the physiologic and pathologic functions of neural cells and will place the concept of selective neuronal vulnerability in a metabolic context.

  10. Idiopathic preretinal glia in aging and age-related macular degeneration.

    PubMed

    Edwards, Malia M; McLeod, D Scott; Bhutto, Imran A; Villalonga, Mercedes B; Seddon, Johanna M; Lutty, Gerard A

    2016-09-01

    During analysis of glia in wholemount aged human retinas, frequent projections onto the vitreal surface of the inner limiting membrane (ILM) were noted. The present study characterized these preretinal glial structures. The amount of glial cells on the vitreal side of the ILM was compared between eyes with age-related macular degeneration (AMD) and age-matched control eyes. Retinal wholemounts were stained for markers of retinal astrocytes and activated Müller cells (glial fibrillary acidic protein, GFAP), Müller cells (vimentin, glutamine synthetase) and microglia/hyalocytes (IBA-1). Retinal vessels were labeled with UEA lectin. Images were collected using a Zeiss LSM 710 confocal microscope. Retinas were then cryopreserved. Laminin labeling of cryosections determined the location of glial structures in relation to the ILM. All retinas investigated herein had varied amounts of preretinal glia. These glial structures were classified into three groups based on size: sprouts, blooms, and membranes. The simplest of the glial structures observed were focal sprouts of singular GFAP-positive cells or processes on the vitreal surface of the ILM. The intermediate structures observed, glial blooms, were created by multiple cells/processes exiting from a single point and extending along the vitreoretinal surface. The most extensive structures, glial membranes, consisted of compact networks of cells and processes. Preretinal glia were observed in all areas of the retina but they were most prominent over large vessels. While all glial blooms and membranes contained vimentin and GFAP-positive cells, these proteins did not always co-localize. Many areas had no preretinal GFAP but had numerous vimentin only glial sprouts. In double labeled glial sprouts, vimentin staining extended beyond that of GFAP. Hyalocytes and microglia were detected along with glial sprouts, blooms, and membranes. They did not, however, concentrate in the retina below these structures. Cross sectional

  11. Parabiosis for the study of age-related chronic disease

    PubMed Central

    Eggel, Alexander; Wyss-Coray, Tony

    2014-01-01

    Summary Modern medicine wields the power to treat large numbers of diseases and injuries most of us would have died from just a hundred years ago. In view of this tremendous achievement, it can seem as if progress has slowed, and we have been unable to impact the most devastating diseases of our time. Chronic diseases of age such as cardiovascular disease, diabetes, osteoarthritis, or Alzheimer’s disease turn out to be of a complexity that may require transformative ideas and paradigms to understand and treat them. Parabiosis, which mimics aspects of the naturally occurring shared blood supply in conjoined twins in humans and certain animals, may just have the power to be such a transformative experimental paradigm. Forgotten and now shunned in many countries, it has contributed to major breakthroughs in tumor biology, endocrinology, and transplantation research in the past century, and a set of new studies in the US and Britain report stunning advances in stem cell biology and tissue regeneration using parabiosis between young and old mice. We review here briefly the history of parabiosis and discuss its utility to study physiological and pathophysiological processes. We argue that parabiosis is a technique that should enjoy wider acceptance and application, and that policies should be revisited especially if one is to study complex age-related, chronic disorders. PMID:24496774

  12. Eye Conditions in Older Adults: Age-Related Macular Degeneration.

    PubMed

    Iroku-Malize, Tochi; Kirsch, Scott

    2016-06-01

    Age-related macular degeneration (AMD) causes a progressive loss of photoreceptors in the macula. It is the most common cause of legal blindness in the United States, and some form of AMD is thought to affect more than 9 million individuals. Risk factors include older age, smoking, dyslipidemia, obesity, white race, female sex, and a family history of AMD. There are two types of advanced AMD: nonexudative (dry or geographic atrophy) and exudative (wet or neovascular). Both cause progressive central vision loss with intact peripheral vision. Nonexudative AMD accounts for 80% to 90% of all advanced cases, and more than 90% of patients with severe vision loss have exudative AMD. On ophthalmoscopic examination, early findings include drusen (ie, yellow deposits in the retina). Prominent choroidal vessels, subretinal edema, and/or hemorrhage are seen in wet AMD. Regular eye examinations, visual field testing, fluorescein angiography, and optical coherence tomography are used for diagnosis and to guide management. There is no specific therapy for dry AMD, but antioxidant supplementation may be helpful. Intravitreal injection of a vascular endothelial growth factor inhibitor is the treatment of choice for wet AMD. Optical aids and devices can help to maximize function for patients with AMD. PMID:27348529

  13. Endocrine causes of age-related bone loss and osteoporosis.

    PubMed

    Riggs, B Lawrence

    2002-01-01

    Women have an early postmenopausal phase of rapid bone loss that lasts for 5-10 years after menopause, whereas both ageing women and men have a slow continuous phase of bone loss that lasts indefinitely. In women, the rapid phase is mediated mainly by loss of the direct restraining effect of oestrogen on bone cell function, whereas the slow phase is mediated mainly by the loss of oestrogen action on extraskeletal calcium homeostasis leading to net calcium wasting and secondary hyperparathyroidism. Because elderly men have low serum bioavailable oestrogen and testosterone levels, and because recent data suggest that oestrogen is the main sex steroid regulating bone metabolism in men, oestrogen deficiency may also be the principal cause of bone loss in elderly men. Decreased bone formation contributes to bone loss in both genders and may be caused by a decreased production of growth hormone and IGF1 as well as oestrogen and testosterone deficiency. Other changes in endocrine secretion, although present in the elderly, seem less important in the pathophysiology of age-related bone loss and osteoporosis. PMID:11855691

  14. Age-related changes in matching novel objects across viewpoints

    PubMed Central

    Konar, Yaroslav; Vuong, Quoc C.; Bennett, Patrick J.; Sekuler, Allison B.

    2016-01-01

    Object recognition is an important visual process. We are not only required to recognize objects across a variety of lighting conditions and variations in size, but also across changes in viewpoint. It has been shown that reaction times in object matching increase as a function of increasing angular disparity between two views of the same object, and it is thought that this is related to the time it takes to mentally rotate an object. Recent studies have shown that object rotations for familiar objects affect older subjects differently than younger subjects. To investigate the general normalization effects for recognizing objects across different viewpoints regardless of visual experience with an object, in the current study we used novel 3D stimuli. Older and younger subjects matched objects across a variety of viewpoints along both in-depth and picture-plane rotations. Response times (RTs) for in-depth rotations were generally slower than for picture plane rotations and older subjects, overall, responded slower than younger subjects. However, a male RT advantage was only found for objects that differed by large, in-depth rotations. Compared to younger subjects, older subjects were not only slower but also less accurate at matching objects across both rotation axes. The age effect was primarily due to older male subjects performing worse than younger male subjects, whereas there was no significant age difference for female subjects. In addition, older males performed even worse than older females, which argues against a general male advantage in mental rotations tasks. PMID:21784094

  15. Eye Conditions in Older Adults: Age-Related Macular Degeneration.

    PubMed

    Iroku-Malize, Tochi; Kirsch, Scott

    2016-06-01

    Age-related macular degeneration (AMD) causes a progressive loss of photoreceptors in the macula. It is the most common cause of legal blindness in the United States, and some form of AMD is thought to affect more than 9 million individuals. Risk factors include older age, smoking, dyslipidemia, obesity, white race, female sex, and a family history of AMD. There are two types of advanced AMD: nonexudative (dry or geographic atrophy) and exudative (wet or neovascular). Both cause progressive central vision loss with intact peripheral vision. Nonexudative AMD accounts for 80% to 90% of all advanced cases, and more than 90% of patients with severe vision loss have exudative AMD. On ophthalmoscopic examination, early findings include drusen (ie, yellow deposits in the retina). Prominent choroidal vessels, subretinal edema, and/or hemorrhage are seen in wet AMD. Regular eye examinations, visual field testing, fluorescein angiography, and optical coherence tomography are used for diagnosis and to guide management. There is no specific therapy for dry AMD, but antioxidant supplementation may be helpful. Intravitreal injection of a vascular endothelial growth factor inhibitor is the treatment of choice for wet AMD. Optical aids and devices can help to maximize function for patients with AMD.

  16. Age-related synthesis of glucocorticoids in thymocytes

    SciTech Connect

    Qiao Shengjun Chen Liying; Okret, Sam; Jondal, Mikael

    2008-10-01

    Glucocorticoids (GCs) are primarily synthesized in the adrenal glands but an ectopic production has also been reported in the brain, the gastrointestinal tract and in thymic epithelial cells (TEC). Here we show that thymocytes express genes encoding for all enzymes required for de novo GC synthesis and produce the hormone as demonstrated by both a GC specific reporter assay and a corticosterone specific ELISA assay. Interestingly, GC synthesis is detectable in cells from young mice (4 weeks) and thereafter increases during aging (14-22 weeks) together with an increased gene expression of the rate-limiting enzymes StAR and CYP11A1. Hormone production occurred at a thymocyte differentiation stage characterized by being double positive for the CD4 and CD8 surface markers but was found to be unrelated to CD69 expression, a marker for thymocytes undergoing positive selection. No GC synthesis was found in resting or anti-CD3 activated CD4 and CD8 positive T cells isolated from the spleen. Thymocyte-derived GC had an anti-proliferative effect on a GR-transfected cell line and induced apoptosis in thymocytes. The age- and differentiation stage-related GC synthesis in thymocytes may play a role in the involution process that the thymus gland undergoes.

  17. Polymer Aging Techniques Applied to Degradation of a Polyurethane Propellant Binder

    SciTech Connect

    Assink, R.A.; Celina, M.; Graham, A.C.; Minier, L.M.

    1999-07-27

    The oxidative thermal aging of a crosslinked hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) polyurethane rubber, commonly used as the polymeric binder matrix in solid rocket propellants, was studied at temperatures of RT to 125 C. We investigate changes in tensile elongation, mechanical hardening, polymer network properties, density, O{sub 2} permeation and molecular chain dynamics using a range of techniques including solvent swelling, detailed modulus profiling and NMR relaxation measurements. Using extensive data superposition and highly sensitive oxygen consumption measurements, we critically evaluate the Arrhenius methodology, which normally assumes a linear extrapolation of high temperature aging data. Significant curvature in the Arrhenius diagram of these oxidation rates was observed similar to previous results found for other rubber materials. Preliminary gel/network properties suggest that crosslinking is the dominant process at higher temperatures. We also assess the importance of other constituents such as ammonium perchlorate or aluminum powder in the propellant formulation.

  18. Gene-Diet Interactions in Age-Related Macular Degeneration.

    PubMed

    Rowan, Sheldon; Taylor, Allen

    2016-01-01

    Age-related macular degeneration (AMD) is a prevalent blinding disease, accounting for roughly 50 % of blindness in developed nations. Very significant advances have been made in terms of discovering genetic susceptibilities to AMD as well as dietary risk factors. To date, nutritional supplementation is the only available treatment option for the dry form of the disease known to slow progression of AMD. Despite an excellent understanding of genes and nutrition in AMD, there is remarkably little known about gene-diet interactions that may identify efficacious approaches to treat individuals. This review will summarize our current understanding of gene-diet interactions in AMD with a focus on animal models and human epidemiological studies.

  19. A Revised Hemodynamic Theory of Age-Related Macular Degeneration.

    PubMed

    Gelfand, Bradley D; Ambati, Jayakrishna

    2016-08-01

    Age-related macular degeneration (AMD) afflicts one out of every 40 individuals worldwide, causing irreversible central blindness in millions. The transformation of various tissue layers within the macula in the retina has led to competing conceptual models of the molecular pathways, cell types, and tissues responsible for the onset and progression of AMD. A model that has persisted for over 6 decades is the hemodynamic, or vascular theory of AMD progression, which states that vascular dysfunction of the choroid underlies AMD pathogenesis. Here, we re-evaluate this hypothesis in light of recent advances on molecular, anatomic, and hemodynamic changes underlying choroidal dysfunction in AMD. We propose an updated, detailed model of hemodynamic dysfunction as a mechanism of AMD development and progression. PMID:27423265

  20. Molecular pathology of age-related macular degeneration

    PubMed Central

    Ding, Xiaoyan; Patel, Mrinali; Chan, Chi-Chao

    2009-01-01

    Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in the world. Although the etiology and pathogenesis of AMD remain largely unclear, a complex interaction of genetic and environmental factors is thought to exist. AMD pathology is characterized by degeneration involving the retinal photoreceptors, retinal pigment epithelium, and Bruch’s membrane, as well as, in some cases, alterations in choroidal capillaries. Recent research on the genetic and molecular underpinnings of AMD brings to light several basic molecular pathways and pathophysiological processes that might mediate AMD risk, progression, and/or response to therapy. This review summarizes, in detail, the molecular pathological findings in both humans and animal models, including genetic variations in CFH, CX3CR1, and ARMS2/HtrA1, as well as the role of numerous molecules implicated in inflammation, apoptosis, cholesterol trafficking, angiogenesis, and oxidative stress. PMID:19026761

  1. Radiation Therapy for Neovascular Age-related Macular Degeneration

    SciTech Connect

    Kishan, Amar U.; Modjtahedi, Bobeck S.; Morse, Lawrence S.; Lee, Percy

    2013-03-01

    In the enormity of the public health burden imposed by age-related macular degeneration (ARMD), much effort has been directed toward identifying effective and efficient treatments. Currently, anti-vascular endothelial growth factor (VEGF) injections have demonstrated considerably efficacy in treating neovascular ARMD, but patients require frequent treatment to fully benefit. Here, we review the rationale and evidence for radiation therapy of ARMD. The results of early photon external beam radiation therapy are included to provide a framework for the sequential discussion of evidence for the usage of stereotactic radiation therapy, proton therapy, and brachytherapy. The evidence suggests that these 3 modern modalities can provide a dose-dependent benefit in the treatment of ARMD. Most importantly, preliminary data suggest that all 3 can be used in conjunction with anti-VEGF therapeutics, thereby reducing the frequency of anti-VEGF injections required to maintain visual acuity.

  2. Targeting MAPK Signaling in Age-Related Macular Degeneration

    PubMed Central

    Kyosseva, Svetlana V.

    2016-01-01

    Age-related macular degeneration (AMD) is a major cause of irreversible blindness affecting elderly people in the world. AMD is a complex multifactorial disease associated with demographic, genetics, and environmental risk factors. It is well established that oxidative stress, inflammation, and apoptosis play critical roles in the pathogenesis of AMD. The mitogen-activated protein kinase (MAPK) signaling pathways are activated by diverse extracellular stimuli, including growth factors, mitogens, hormones, cytokines, and different cellular stressors such as oxidative stress. They regulate cell proliferation, differentiation, survival, and apoptosis. This review addresses the novel findings from human and animal studies on the relationship of MAPK signaling with AMD. The use of specific MAPK inhibitors may represent a potential therapeutic target for the treatment of this debilitating eye disease. PMID:27385915

  3. Complement factor H polymorphism and age-related macular degeneration.

    PubMed

    Edwards, Albert O; Ritter, Robert; Abel, Kenneth J; Manning, Alisa; Panhuysen, Carolien; Farrer, Lindsay A

    2005-04-15

    Age-related macular degeneration (AMD) is a common, late-onset, and complex trait with multiple risk factors. Concentrating on a region harboring a locus for AMD on 1q25-31, the ARMD1 locus, we tested single-nucleotide polymorphisms for association with AMD in two independent case-control populations. Significant association (P = 4.95 x 10(-10)) was identified within the regulation of complement activation locus and was centered over a tyrosine-402 --> histidine-402 protein polymorphism in the gene encoding complement factor H. Possession of at least one histidine at amino acid position 402 increased the risk of AMD 2.7-fold and may account for 50% of the attributable risk of AMD.

  4. Age-related macular degeneration and the complement system.

    PubMed

    Khandhadia, S; Cipriani, V; Yates, J R W; Lotery, A J

    2012-02-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. It is a complex multifactorial disease, and despite new advances in treatment, many patients still succumb to visual impairment. The complement pathway has been implicated in the pathogenesis of many diseases, and recently variants in several genes encoding complement pathway proteins have been associated with AMD. Complement proteins have been found in histological specimens of eyes with AMD. Altered levels of both intrinsic complement proteins and activated products have been found in the circulation of patients with AMD. Complement activation may be triggered by oxidative stress, resulting from retinal exposure to incoming light; indeed an inter-play between these two pathological processes seems to exist. Finally, complement inhibitors are currently being evaluated in clinical trials. This article reviews the role of the complement system in AMD, and the potential of complement inhibition in preventing the devastating blindness resulting from this disease.

  5. Optical thickness as related to pollutant episodes and the concentration of visibility degrading pollutants

    NASA Technical Reports Server (NTRS)

    Prospero, J. M.; Savoie, D.; Snowdon, T.; Ewbank, P.

    1983-01-01

    A network of six sun photometers was placed in the central and northeast United States during the months of July through October, 1931. The objective of the program was to obtain measurements of atmospheric turbidity which can be related to the concentration of visibility-degrading pollutants in the atmosphere. These measurements serve as ground truth for a program to develop remote sensing techniques for measuring the vertically integrated aerosol concentrations in pollution episodes. The sun photometers measure the direct solar radiation in four passbands: 380 nm, 500 nm, 875 nm and 940 nm. The first three passbands will be used for measuring the aerosol optical depth and the last for measuring precipitable water.

  6. DNA-related pathways defective in human premature aging.

    PubMed

    Bohr, Vilhelm A

    2002-05-07

    One of the major issues in studies on aging is the choice of biological model system. The human premature aging disorders represent excellent model systems for the study of the normal aging process, which occurs at a much earlier stage in life in these individuals than in normals. The patients with premature aging also get the age associated diseases at an early stage in life, and thus age associated disease can be studied as well. It is thus of great interest to understand the molecular pathology of these disorders.

  7. Heterogeneity in age-related white matter changes.

    PubMed

    Schmidt, Reinhold; Schmidt, Helena; Haybaeck, Johannes; Loitfelder, Marisa; Weis, Serge; Cavalieri, Margherita; Seiler, Stephan; Enzinger, Christian; Ropele, Stefan; Erkinjuntti, Timo; Pantoni, Leonardo; Scheltens, Philip; Fazekas, Franz; Jellinger, Kurt

    2011-08-01

    White matter changes occur endemically in routine magnetic resonance imaging (MRI) scans of elderly persons. MRI appearance and histopathological correlates of white matter changes are heterogeneous. Smooth periventricular hyperintensities, including caps around the ventricular horns, periventricular lining and halos are likely to be of non-vascular origin. They relate to a disruption of the ependymal lining with subependymal widening of the extracellular space and have to be differentiated from subcortical and deep white matter abnormalities. For the latter a distinction needs to be made between punctate, early confluent and confluent types. Although punctate white matter lesions often represent widened perivascular spaces without substantial ischemic tissue damage, early confluent and confluent lesions correspond to incomplete ischemic destruction. Punctate abnormalities on MRI show a low tendency for progression, while early confluent and confluent changes progress rapidly. The causative and modifying pathways involved in the occurrence of sporadic age-related white matter changes are still incompletely understood, but recent microarray and genome-wide association approaches increased the notion of pathways that might be considered as targets for therapeutic intervention. The majority of differentially regulated transcripts in white matter lesions encode genes associated with immune function, cell cycle, proteolysis, and ion transport. Genome-wide association studies identified six SNPs mapping to a locus on chromosome 17q25 to be related to white matter lesion load in the general population. We also report first and preliminary data that demonstrate apolipoprotein E (ApoE) immunoreactivity in white matter lesions and support epidemiological findings indicating that ApoE is another factor possibly related to white matter lesion occurrence. Further insights come from modern MRI techniques, such as diffusion tensor and magnetization transfer imaging, as they

  8. Age-Related Macular Degeneration: Genetics and Biology.

    PubMed

    Kumaramanickavel, Govindasamy

    2016-01-01

    Age-related macular degeneration (AMD), widely prevalent across the globe, is a major stakeholder among adult visual morbidity and blindness, not only in the Western world but also in Asia. Several risk factors have been identified, including critical genetic factors, which were never imagined 2 decades ago. The etiopathogenesis is emerging to demonstrate that immune and complement-related inflammation pathway members chronically exposed to environmental insults could justifiably influence disease morbidity and treatment outcomes. Approximately half a dozen physiological and biochemical cascades are disrupted in the AMD disease genesis, eventually leading to the distortion and disruption of the subretinal space, subretinal pigment epithelium, and Bruch membrane, thus setting off chaos and disorder for signs and symptoms to manifest. Approximately 3 dozen genetic factors have so far been identified, including the recent ones, through powerful genomic technologies and large robust sample sizes. The noteworthy genetic variants (common and rare) are complement factor H, complement factor H-related genes 1 to 5, C3, C9, ARMS2/HTRA1, vascular endothelial growth factor A, vascular endothelial growth factor receptor 2/KDR, and rare variants (show causal link) such as TIMP3, fibrillin, COL4A3, MMP19, and MMP9. Despite the enormous amount of scientific information generated over the years, diagnostic genetic or biomarker tests are still not available for clinicians to understand the natural course of the disease and its management in a patient. However, further research in the field should reduce this gap not only by aiding the clinician but also through the possibilities of clinical intervention with complement pathway-related inhibitors entering preclinical and clinical trials in the near future. PMID:27488064

  9. Gene Therapy for Age-Related Macular Degeneration.

    PubMed

    Constable, Ian Jeffery; Blumenkranz, Mark Scott; Schwartz, Steven D; Barone, Sam; Lai, Chooi-May; Rakoczy, Elizabeth Piroska

    2016-01-01

    The purpose of this article was to evaluate safety and signals of efficacy of gene therapy with subretinal rAAV.sFlt-1 for wet age-related macular degeneration (wet AMD). A phase 1 dose-escalating single-center controlled unmasked human clinical trial was followed up by extension of the protocol to a phase 2A single-center trial. rAAV.sFlt-1 vector was used to deliver a naturally occurring anti-vascular endothelial growth factor agent, sFlt-1, into the subretinal space. In phase 1, step 1 randomized 3 subjects to low-dose rAAV.sFlt-1 (1 × 10 vector genomes) and 1 subject to the control arm; step 2 randomized an additional 3 subjects to treatment with high-dose rAAV.sFlt-1 (1 × 10 vector genomes) and 1 subject to the control arm. Follow-up studies demonstrated that rAAV.sFlt-1 was well tolerated with a favorable safety profile in these elderly subjects with wet AMD. Subretinal injection was highly reproducible, and no drug-related adverse events were reported. Procedure-related adverse events were mild and self-resolving. Two phakic patients developed cataract and underwent cataract surgery. Four of the 6 patients responded better than the small control group in this study and historical controls in terms of maintaining vision and a relatively dry retina with zero ranibizumab retreatments per annum. Two patients required 1 ranibizumab injection over the 52-week follow-up period. rAAV.sFlt-1 gene therapy may prove to be a potential adjunct or alternative to conventional intravitreal injection for patients with wet AMD by providing extended delivery of a naturally occurring antiangiogenic protein. PMID:27488071

  10. Age-Related Differences in Lexical Access Relate to Speech Recognition in Noise

    PubMed Central

    Carroll, Rebecca; Warzybok, Anna; Kollmeier, Birger; Ruigendijk, Esther

    2016-01-01

    Vocabulary size has been suggested as a useful measure of “verbal abilities” that correlates with speech recognition scores. Knowing more words is linked to better speech recognition. How vocabulary knowledge translates to general speech recognition mechanisms, how these mechanisms relate to offline speech recognition scores, and how they may be modulated by acoustical distortion or age, is less clear. Age-related differences in linguistic measures may predict age-related differences in speech recognition in noise performance. We hypothesized that speech recognition performance can be predicted by the efficiency of lexical access, which refers to the speed with which a given word can be searched and accessed relative to the size of the mental lexicon. We tested speech recognition in a clinical German sentence-in-noise test at two signal-to-noise ratios (SNRs), in 22 younger (18–35 years) and 22 older (60–78 years) listeners with normal hearing. We also assessed receptive vocabulary, lexical access time, verbal working memory, and hearing thresholds as measures of individual differences. Age group, SNR level, vocabulary size, and lexical access time were significant predictors of individual speech recognition scores, but working memory and hearing threshold were not. Interestingly, longer accessing times were correlated with better speech recognition scores. Hierarchical regression models for each subset of age group and SNR showed very similar patterns: the combination of vocabulary size and lexical access time contributed most to speech recognition performance; only for the younger group at the better SNR (yielding about 85% correct speech recognition) did vocabulary size alone predict performance. Our data suggest that successful speech recognition in noise is mainly modulated by the efficiency of lexical access. This suggests that older adults’ poorer performance in the speech recognition task may have arisen from reduced efficiency in lexical access

  11. Age-Related Differences in Lexical Access Relate to Speech Recognition in Noise.

    PubMed

    Carroll, Rebecca; Warzybok, Anna; Kollmeier, Birger; Ruigendijk, Esther

    2016-01-01

    Vocabulary size has been suggested as a useful measure of "verbal abilities" that correlates with speech recognition scores. Knowing more words is linked to better speech recognition. How vocabulary knowledge translates to general speech recognition mechanisms, how these mechanisms relate to offline speech recognition scores, and how they may be modulated by acoustical distortion or age, is less clear. Age-related differences in linguistic measures may predict age-related differences in speech recognition in noise performance. We hypothesized that speech recognition performance can be predicted by the efficiency of lexical access, which refers to the speed with which a given word can be searched and accessed relative to the size of the mental lexicon. We tested speech recognition in a clinical German sentence-in-noise test at two signal-to-noise ratios (SNRs), in 22 younger (18-35 years) and 22 older (60-78 years) listeners with normal hearing. We also assessed receptive vocabulary, lexical access time, verbal working memory, and hearing thresholds as measures of individual differences. Age group, SNR level, vocabulary size, and lexical access time were significant predictors of individual speech recognition scores, but working memory and hearing threshold were not. Interestingly, longer accessing times were correlated with better speech recognition scores. Hierarchical regression models for each subset of age group and SNR showed very similar patterns: the combination of vocabulary size and lexical access time contributed most to speech recognition performance; only for the younger group at the better SNR (yielding about 85% correct speech recognition) did vocabulary size alone predict performance. Our data suggest that successful speech recognition in noise is mainly modulated by the efficiency of lexical access. This suggests that older adults' poorer performance in the speech recognition task may have arisen from reduced efficiency in lexical access; with an

  12. Oxidative Damage and Autophagy in the Human Trabecular Meshwork as Related with Ageing

    PubMed Central

    Pulliero, Alessandra; Seydel, Anke; Camoirano, Anna; Saccà, Sergio Claudio; Sandri, Marco; Izzotti, Alberto

    2014-01-01

    Autophagy is an intracellular lysosomal degradation process induced under stress conditions. Autophagy also plays a major role in ocular patho-physiology. Molecular aging does occur in the trabecular meshwork, the main regulator of aqueous humor outflow, and trabecular meshwork senescence is accompanied by increased oxidative stress. However, the role of autophagy in trabecular meshwork patho-physiology has not yet been examined in vivo in human ocular tissues. The purpose of the herein presented study is to evaluate autophagy occurrence in ex-vivo collected human trabecular meshwork specimens and to evaluate the relationship between autophagy, oxidative stress, and aging in this tissue. Fresh trabecular meshwork specimens were collected from 28 healthy corneal donors devoid of ocular pathologies and oxidative DNA damage, and LC3 and p62 protein expression analyzed. In a subset of 10 subjects, further to trabecular meshwork proteins, the amounts of cathepesin L and ubiquitin was analyzed by antibody microarray in aqueous humor. Obtained results demonstrate that autophagy activation, measured by LC3II/I ratio, is related with. oxidative damage occurrence during aging in human trabecular meshwork. The expression of autophagy marker p62 was lower in subjects older than 60 years as compared to younger subjects. These findings reflect the occurrence of an agedependent increase in the autophagy as occurring in the trabecular meshwork. Furthermore, we showed that aging promotes trabecular-meshwork senescence due to increased oxidative stress paralleled by autophagy increase. Indeed, both oxidative DNA damage and autophagy were more abundant in subjects older than 60 years. These findings shed new light on the role of oxidative damage and autophagy during trabecular-meshwork aging. PMID:24945152

  13. Review of nutrient actions on age-related macular degeneration.

    PubMed

    Zampatti, Stefania; Ricci, Federico; Cusumano, Andrea; Marsella, Luigi Tonino; Novelli, Giuseppe; Giardina, Emiliano

    2014-02-01

    The actions of nutrients and related compounds on age-related macular degeneration (AMD) are explained in this review. The findings from 80 studies published since 2003 on the association between diet and supplements in AMD were reviewed. Antioxidants and other nutrients with an effect on AMD susceptibility include carotenoids (lutein and zeaxanthin, β-carotene), vitamins (vitamin A, E, C, D, B), mineral supplements (zinc, copper, selenium), dietary fatty acids [monounsaturated fatty acids, polyunsaturated fatty acids (PUFA both omega-3 PUFA and omega-6 PUFA), saturated fatty acids and cholesterol], and dietary carbohydrates. The literature revealed that many of these antioxidants and nutrients exert a protective role by functioning synergistically. Specifically, the use of dietary supplements with targeted actions can provide minimal benefits on the onset or progression of AMD; however, this does not appear to be particularly beneficial in healthy people. Furthermore, some supplements or nutrients have demonstrated discordant effects on AMD in some studies. Since intake of dietary supplements, as well as exposure to damaging environmental factors, is largely dependent on population habits (including dietary practices) and geographical localization, an overall healthy diet appears to be the best strategy in reducing the risk of developing AMD. As of now, the precise mechanism of action of certain nutrients in AMD prevention remains unclear. Thus, future studies are required to examine the effects that nutrients have on AMD and to determine which factors are most strongly correlated with reducing the risk of AMD or preventing its progression. PMID:24461310

  14. The Age-Related Properties of the HD 98800 System

    NASA Technical Reports Server (NTRS)

    Soderblom, David R.; Henry, Todd J.; Shetrone, Matthew D.; Jones, Burton F.; Saar, Steven H.

    1996-01-01

    We present optical spectroscopy of the field K star system HD 98800, which has been found to have significant infrared emission from circumstellar material. The lithium abundances of the stars in HD 98800 are well above those of Pleiades of similar color, but activity levels and rotation in these stars are at or below Pleiades level. Thus, it is not yet possible to say whether HD 98800 is or is not a pre-main-sequence system, and it is possible that its components are on or near the zero-age main sequence. However, the two visible objects that make up HD 98800 both have high levels of lithium and activity, strongly suggesting that they are physically related to one another. As shown by Torres and coworkers, having these stars physically tied implies that their relative orbit is highly eccentric and highly inclined to our line of sight, and it also means that we are viewing the HD 98800 system at an unusual time in its orbit.

  15. Modifiable risk factors for age-related macular degeneration.

    PubMed

    Guymer, Robyn H; Chong, Elaine Wei-Tinn

    2006-05-01

    Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in Australia and other Western countries. As there is no cure for AMD, and treatments to stop its progression have met with limited success, there is an interest in identifying modifiable risk factors to prevent or slow disease progression. To date, smoking is the only proven modifiable risk factor for AMD. Other factors under study include (i) cardiovascular risk factors such as hypertension, body mass index, and atherosclerosis; and (ii) dietary risk factors including fat and antioxidant intake, but so far these studies have produced conflicting results. Dietary fat in relation to AMD has recently attracted media attention. Despite very limited work supporting an association between vegetable fat and AMD, widespread publicity advocating margarine as a cause of AMD and encouraging use of butter instead has caused confusion and anxiety among sufferers of AMD and the general public, as well as concern among health professionals. The antioxidant carotenoids--lutein and zeaxanthin--found in dark green or yellow vegetables exist in high concentrations in the macula and are hypothesised to play a protective role. Of nine controlled trials of supplementation with carotenoids and other antioxidants, three suggested that various combinations of antioxidants and carotenoids were protective. While a low-fat diet rich in dark green and yellow vegetables is advocated in general, any specific recommendations regarding certain fats or antioxidant supplementation and AMD are not based on consistent findings at this stage. PMID:16646746

  16. [Study on degradation of polycyclic aromatic hydrocarbons (PAHs) with different additional carbon sources in aged contaminated soil].

    PubMed

    Yin, Chun-Qin; Jiang, Xin; Wang, Fang; Wang, Cong-Ying

    2012-02-01

    This study was conducted with different additional carbon sources (such as: glucose, DL-malic acid, citrate, urea and ammonium acetate) to elucidate the degradation of polycyclic aromatic hydrocarbons (PAHs) in aged contaminated soil under an indoor simulation experiment. The results showed that the quantity of CO2 emission in different additional carbon sources treatments was obviously much more than that of check treatment in the first week, and the quantity of CO2 emission in DL-malic acid treatment was the largest. The average CO2 production decreased in an order urea > glucose approximately citrate approximately DL-malic acid approximately ammonium acetate > check. Meanwhile, the amount of volatized PAHs in applied carbon sources treatments was significantly less than that in check treatment. The amount of three volatized PAHs decreased in an order phenanthrene > fluoranthene > benzo(b)fluoranthene. Compared with the check treatment, the average degradation rates of the three PAHs were significantly augmented in the supplied carbon sources treatments, in which rates of the three PAHs were much higher in DL-malic acid and urea treatments than those in other treatments. The largest proportion of residual was benzo(b)fluoranthene (from 72% to 81%) among three PAHs compounds, followed by fluoranthene (from 53% to 70% ) and phenanthrene (from 27% to 44%).

  17. Age-Related Differences in Evaluating Developmental Stability

    ERIC Educational Resources Information Center

    Mustafic, Maida; Freund, Alexandra M.

    2013-01-01

    Two studies examined the hypothesis that the evaluation of developmental stability changes across adulthood. Results of Study 1 ("N" = 119) supported the expectation that older adults ("M"[subscript age] = 65.29 years)--compared to younger ("M"[subscript age] = 23.38 years) and middle-aged adults…

  18. Degradation of lithium ion batteries employing graphite negatives and nickel-cobalt-manganese oxide + spinel manganese oxide positives: Part 1, aging mechanisms and life estimation

    NASA Astrophysics Data System (ADS)

    Wang, John; Purewal, Justin; Liu, Ping; Hicks-Garner, Jocelyn; Soukazian, Souren; Sherman, Elena; Sorenson, Adam; Vu, Luan; Tataria, Harshad; Verbrugge, Mark W.

    2014-12-01

    We examine the aging and degradation of graphite/composite metal oxide cells. Non-destructive electrochemical methods were used to monitor the capacity loss, voltage drop, resistance increase, lithium loss, and active material loss during the life testing. The cycle life results indicated that the capacity loss was strongly impacted by the rate, temperature, and depth of discharge (DOD). Lithium loss and active electrode material loss were studied by the differential voltage method; we find that lithium loss outpaces active material loss. A semi-empirical life model was established to account for both calendar-life loss and cycle-life loss. For the calendar-life equation, we adopt a square root of time relation to account for the diffusion limited capacity loss, and an Arrhenius correlation is used to capture the influence of temperature. For the cycle life, the dependence on rate is exponential while that for time (or charge throughput) is linear.

  19. Long-term ageing and materials degradation of hybrid mica compressive seals for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Chou, Yeong-Shyung; Stevenson, J. W.

    Hybrid phlogopite mica seals with silver interlayers were evaluated in long-term isothermal ageing tests in a dual environment consisting of dilute hydrogen versus air at 800 °C. High-temperature leak tests with helium showed very stable leakage of 0.01-0.02 sccm cm -1 for 28,366 h under a low applied compressive stress of 82 kPa (12 psi). Post-mortem SEM and EDS analyses of the mica showed minimum degradation in terms of changes in microstructure and chemical composition, although there appeared to be some Ag migration and segregation at interstices between mica flakes. Fluorine was also found to be released from mica. Overall, the low, constant leakage through the hybrid mica/Ag seals clearly demonstrated a very promising candidate for SOFC sealing.

  20. Fracture Resistance of Hybrid Glass Matrix Composite and Its Degradation Due to Thermal Ageing and Thermal Shock

    NASA Astrophysics Data System (ADS)

    Dlouhý, Ivo; Chlup, Zdenêk; Atiq, Shabbar; Boccaccini, Aldo R.

    In brittle matrix composites reinforced by continuous ceramic fibres, the favourable fracture behaviour is provided by the presence of weak fibre/matrix interfaces, which lead to the fibre pullout effect [1]. The thermal stability and high temperature mechanical properties of silicate matrix composites reinforced by carbon and SiC based fibres in oxidising environments have been investigated quite extensively in the past by conducting thermal aging and thermal cycling experiments over a wide range of temperatures [2-5]. A common result of investigations conducted at temperatures in the range 500-700°C is that there is a decrease of tensile and flexural strength of the composites. It has been shown that this is the consequence of oxidation of the fibres, in case of carbon fibre reinforced composites, or of degradation of the fibre/matrix interphase, which is in fact a carbon-rich nanometric interfacial layer, in SiC fibre reinforced composites [2-5].

  1. Long-term ageing and materials degradation of hybrid mica compressive seals for solid oxide fuel cells

    SciTech Connect

    Chou, Y. S.; Stevenson, Jeffry W.

    2009-06-15

    Hybrid phlogopite mica seals with silver interlayers were evaluated in long term isothermal ageing tests in a dual environment consisting of dilute hydrogen vs. air at 800 degrees C. High-temperature leak tests with helium showed very stable leakage of 0.01-0.02 sccm/cm for 28366 hrs under a low applied compressive stress of 82 kPa (12 psi). Post-mortem SEM and EDS analyses of the mica showed minimum degradation in terms of changes in microstructure and chemical composition, although there appeared to be some Ag migration and segregation at interstices between mica flakes. Fluorine was also found to be released from mica. Overall, the low, constant leakage through the hybrid mica/Ag seals clearly demonstrated a very promising candidate for SOFC sealing.

  2. Glycolysis in Patients with Age-Related Macular Degeneration

    PubMed Central

    Yokosako, Kanako; Mimura, Tatsuya; Funatsu, Hideharu; Noma, Hidetaka; Goto, Mari; Kamei, Yuko; Kondo, Aki; Matsubara, Masao

    2014-01-01

    Purpose: Retinal adenosine triphosphate is mainly produced via glycolysis, so inhibition of glycolysis may promote the onset and progression of age-related macular degeneration (AMD). When glycolysis is inhibited, pyruvate is metabolized by lactic acid fermentation instead of entering the mitochondrial tricarboxylic acid (TCA) cycle. We measured urinary pyruvate and lactate levels in patients with AMD. Methods: Eight patients with typical AMD (tAMD group) and 9 patients with polypoidal choroidal vasculopathy (PCV group) were enrolled. Urinary levels of pyruvate, lactate, α-hydroxybutyrate, and β-hydroxybutyrate were measured in all patients. Results: The mean urinary levels of pyruvate and lactate were 8.0 ± 2.8 and 7.5 ± 8.3 μg/mg creatinine (reference values: 0.5-6.6 and 0.0-1.6), respectively, with the mean increase over the reference value being 83.6 ± 51.1% and 426.5 ± 527.8%, respectively. In 12 patients (70.6%), the lactate/pyruvate ratio was above the reference range. Urinary levels of α-hydroxybutyrate and β-hydroxybutyrate were decreased by -31.9 ± 15.2% and -33.1 ± 17.5% compared with the mean reference values. There were no significant differences of any of these glycolysis metabolites between the tAMD and PCV groups. Multivariate analysis revealed that none of the variables tested, including patient background factors (age, hypertension, diabetes, hyperlipidemia, cerebrovascular disease, alcohol, smoking, visual acuity, and AMD phenotype), were significantly associated with the lactate/pyruvate ratio. Conclusion: A high lactate/pyruvate ratio is a well-known marker of mitochondrial impairment, and it indicates poor oxidative function in AMD. Our results suggest that increased lactate levels may be implicated in the pathogenesis of AMD. PMID:25191529

  3. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    SciTech Connect

    Gunther, W.E.; Higgins, J.C.; Aggarwal, S.K.

    1991-12-31

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  4. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    SciTech Connect

    Gunther, W.E.; Higgins, J.C. ); Aggarwal, S.K. )

    1991-01-01

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  5. Enhanced degradation of haloacid by heterologous expression in related Burkholderia species.

    PubMed

    Su, Xianbin; Deng, Liyu; Kong, Ka Fai; Tsang, Jimmy S H

    2013-10-01

    Haloacids are environmental pollutant and can be transformed to non-toxic alkanoic acids by microbial dehalogenase. Bacterium Burkholderia species MBA4 was enriched from soil for its ability to bioremediate haloacids such as mono-chloroacetate (MCA), mono-bromoacetate (MBA), 2-mono-chloropropionate, and 2-mono-bromopropionate. MBA4 produces an inducible dehalogenase Deh4a that catalyzes the dehalogenation process. The growth of MBA4 on haloacid also relies on the presence of a haloacid-uptake system. Similar dehalogenase genes can be found in the genome of many related species. However, wildtype Burkholderia caribensis MWAP64, Burkholderia phymatum STM815, and Burkholderia xenovorans LB400 were not able to grow on MCA. When a plasmid containing the regulatory and structural gene of Deh4a was transformed to these species, they were able to grow on haloacid. The specific enzyme activities in these recombinants ranges from 2- to 30-fold that of MBA4 in similar condition. Reverse transcription-quantitative real-time PCR showed that the relative transcript levels in these recombinant strains ranges from 9 to over 1,600 times that of MBA4 in similar condition. A recombinant has produced nearly five times of dehalogenase that MBA4 could ever achieve. While the expressions of Deh4a were more relaxed in these phylogenetically related species, an MCA-uptake activity was found to be inducible. These metabolically engineered strains are better degraders than the haloacid-enriched MBA4.

  6. Annealing neutron damaged silicon bipolar transistors: Relating gain degradation to specific lattice defects

    NASA Astrophysics Data System (ADS)

    Fleming, R. M.; Seager, C. H.; Lang, D. V.; Campbell, J. M.

    2010-09-01

    Isochronal anneal sequences have been carried out on pnp and npn transistors irradiated with fast neutrons at a variety of fluences. The evolution of base and collector currents was utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. Various annealing biases, theoretical modeling, as well as previous deep level transient spectroscopy (DLTS) data, were used to assign the relative magnitude of each of the important defects to the total recombination current. We find that donor-vacancy pairs in the neutral n-type base of our pnp transistors are responsible for about 1/3 of the postdamage lifetime degradation, while the remaining recombination currents can be largely attributed to a cluster-related divacancylike defect which has no shallow state DLTS emission peak. This latter defect anneals gradually from 350 to 590 K. Generation/recombination currents in the base-emitter junctions in both types of devices were found to anneal in a similar, gradual fashion, suggesting that this same cluster-related intrinsic lattice defect is also responsible for the large, damage-induced base currents.

  7. Ancient sandstone condition assessment in relation to degradation, cleaning and consolidation phenomena

    NASA Astrophysics Data System (ADS)

    Drdácký, Miloš; Frankeová, Dita; Slížková, Zuzana

    2015-04-01

    Non-invasive methods for assessing the state of historic stone types rely on measurement of their surface or subsurface characteristics, which are supposed to correlate with objective physical characteristics. Such measurements are influenced by surface conditions of stone, as well as by previous conservation treatments. The authors performed a comprehensive study of characteristics and behaviour of typical sandstone types present in the Charles' Bridge in Prague as a preparatory work for its diagnostic and restoration in order to understand the problem of a large, important, and non-homogeneous (from the material point of view) historic structure, that was intended for repair interventions. The study itself took advantage of the combination of non-invasive, or considerately destructive methods and fully destructive tests, because it was possible to use damaged sandstone blocks, which were extracted from a masonry rail of the bridge before replacement with new elements. Stone characteristics were studied on test specimens prepared from materials in various conditions and after various interventions. Seven types of sandstone were tested in nine sets (degraded surface layer with a crust, degraded surface layer after cleaning, and unweathered core material; all three without any consolidation treatment, and all three after consolidation with two products based on silicic acid ester - Funcosil 100 and 300). The paper will present only selected results of experiments and the most important conclusions taken from the tests and their comparison. During experimental work the following characteristics were investigated: bending strength, modulus of elasticity, ultrasonic velocity, micro-drilling resistance, water uptake, porosity, frost resistance, hydric dilation and thermal dilation. The degraded stone had a rather strong variation of its characteristics along the depth profile from the surface inside the stone ashlar. Therefore, the stone samples were prepared in a form

  8. Dosimetric implications of age related glandular changes in screening mammography

    NASA Astrophysics Data System (ADS)

    Beckett, J. R.; Kotre, C. J.

    2000-03-01

    The UK National Health Service Breast Screening Programme is currently organized to routinely screen women between the ages of 50 and 64, with screening for older women available on request. The lower end of this age range closely matches the median age for the menopause (51 years), during which significant changes in the composition of the breast are known to occur. In order to quantify the dosimetric effect of these changes, radiographic factors and compressed breast thickness data for a cohort of 1258 women aged between 35 and 79 undergoing breast screening mammography have been used to derive estimates of breast glandularity and mean glandular dose (MGD), and examine their variation with age. The variation of mean radiographic exposure factors with age is also investigated. The presence of a significant number of age trial women within the cohort allowed an extended age range to be studied. Estimates of MGD including corrections for breast glandularity based on compressed breast thickness only, compressed breast thickness and age and for each individual woman are compared with the MGD based on the conventional assumption of a 50:50 adipose/glandular composition. It has been found that the use of the conventional 50:50 assumption leads to overestimates of MGD of up to 13% over the age range considered. By using compressed breast thickness to estimate breast glandularity, this error range can be reduced to 8%, whilst age and compressed breast thickness based glandularity estimates result in an error range of 1%.

  9. Oxidative stress, innate immunity, and age-related macular degeneration

    PubMed Central

    Shaw, Peter X.; Stiles, Travis; Douglas, Christopher; Ho, Daisy; Fan, Wei; Du, Hongjun; Xiao, Xu

    2016-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss affecting tens of millions of elderly worldwide. Early AMD is characterized by the appearance of soft drusen, as well as pigmentary changes in the retinal pigment epithelium (RPE). These soft, confluent drusen can progress into two forms of advanced AMD: geographic atrophy (GA, or dry AMD) or choroidal neovascularization (CNV, or wet AMD). Both forms of AMD result in a similar clinical progression in terms of loss of central vision. The exact mechanism for developing early AMD, as well as triggers responsible for progressing to advanced stage of disease, is still largely unknown. However, significant evidence exists demonstrating a complex interplay of genetic and environmental factors as causes of AMD progression. Multiple genes and/or single nucleotide polymorphisms (SNPs) have been found associated with AMD, including various genes involved in the complement pathway, lipid metabolism and extracellular matrix (ECM) remodeling. Of the known genetic contributors to disease risk, the CFH Y402H and HTRA1/ARMS polymorphisms contribute to more than 50% of the genetic risk for AMD. Environmentally, oxidative stress plays a critical role in many aging diseases including cardiovascular disease, cancer, Alzheimer’s disease and AMD. Due to the exposure to sunlight and high oxygen concentration, the oxidative stress burden is higher in the eye than other tissues, which can be further complicated by additional oxidative stressors such as smoking. Increasingly, evidence is accumulating suggesting that functional abnormalities of the innate immune system incurred via high risk genotypes may be contributing to the pathogenesis of AMD by altering the inflammatory homeostasis in the eye, specifically in the handling of oxidation products. As the eye in non-pathological instances maintains a low level of inflammation despite the presence of a relative abundance of potentially inflammatory molecules, we have

  10. The impact of sleep on age-related sarcopenia: Possible connections and clinical implications.

    PubMed

    Piovezan, Ronaldo D; Abucham, Julio; Dos Santos, Ronaldo Vagner Thomatieli; Mello, Marco Tulio; Tufik, Sergio; Poyares, Dalva

    2015-09-01

    Sarcopenia is a geriatric condition that comprises declined skeletal muscle mass, strength and function, leading to the risk of multiple adverse outcomes, including death. Its pathophysiology involves neuroendocrine and inflammatory factors, unfavorable nutritional habits and low physical activity. Sleep may play a role in muscle protein metabolism, although this hypothesis has not been studied extensively. Reductions in duration and quality of sleep and increases in prevalence of circadian rhythm and sleep disorders with age favor proteolysis, modify body composition and increase the risk of insulin resistance, all of which have been associated with sarcopenia. Data on the effects of age-related slow-wave sleep decline, circadian rhythm disruptions and obstructive sleep apnea (OSA) on hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG), somatotropic axes, and glucose metabolism indicate that sleep disorder interventions may affect muscle loss. Recent research associating OSA with the risk of conditions closely related to the sarcopenia process, such as frailty and sleep quality impairment, indirectly suggest that sleep can influence skeletal muscle decline in the elderly. Several protein synthesis and degradation pathways are mediated by growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol and insulin, which act on the cellular and molecular levels to increase or reestablish muscle fiber, strength and function. Age-related sleep problems potentially interfere intracellularly by inhibiting anabolic hormone cascades and enhancing catabolic pathways in the skeletal muscle. Specific physical exercises combined or not with nutritional recommendations are the current treatment options for sarcopenia. Clinical studies testing exogenous administration of anabolic hormones have not yielded adequate safety profiles. Therapeutic approaches targeting sleep disturbances to normalize circadian rhythms and sleep homeostasis may

  11. The impact of sleep on age-related sarcopenia: Possible connections and clinical implications.

    PubMed

    Piovezan, Ronaldo D; Abucham, Julio; Dos Santos, Ronaldo Vagner Thomatieli; Mello, Marco Tulio; Tufik, Sergio; Poyares, Dalva

    2015-09-01

    Sarcopenia is a geriatric condition that comprises declined skeletal muscle mass, strength and function, leading to the risk of multiple adverse outcomes, including death. Its pathophysiology involves neuroendocrine and inflammatory factors, unfavorable nutritional habits and low physical activity. Sleep may play a role in muscle protein metabolism, although this hypothesis has not been studied extensively. Reductions in duration and quality of sleep and increases in prevalence of circadian rhythm and sleep disorders with age favor proteolysis, modify body composition and increase the risk of insulin resistance, all of which have been associated with sarcopenia. Data on the effects of age-related slow-wave sleep decline, circadian rhythm disruptions and obstructive sleep apnea (OSA) on hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG), somatotropic axes, and glucose metabolism indicate that sleep disorder interventions may affect muscle loss. Recent research associating OSA with the risk of conditions closely related to the sarcopenia process, such as frailty and sleep quality impairment, indirectly suggest that sleep can influence skeletal muscle decline in the elderly. Several protein synthesis and degradation pathways are mediated by growth hormone (GH), insulin-like growth factor-1 (IGF-1), testosterone, cortisol and insulin, which act on the cellular and molecular levels to increase or reestablish muscle fiber, strength and function. Age-related sleep problems potentially interfere intracellularly by inhibiting anabolic hormone cascades and enhancing catabolic pathways in the skeletal muscle. Specific physical exercises combined or not with nutritional recommendations are the current treatment options for sarcopenia. Clinical studies testing exogenous administration of anabolic hormones have not yielded adequate safety profiles. Therapeutic approaches targeting sleep disturbances to normalize circadian rhythms and sleep homeostasis may

  12. Oceanobacter-related bacteria are important for the degradation of petroleum aliphatic hydrocarbons in the tropical marine environment.

    PubMed

    Teramoto, Maki; Suzuki, Masahito; Okazaki, Fumiyoshi; Hatmanti, Ariani; Harayama, Shigeaki

    2009-10-01

    Petroleum-hydrocarbon-degrading bacteria were obtained after enrichment on crude oil (as a 'chocolate mousse') in a continuous supply of Indonesian seawater amended with nitrogen, phosphorus and iron nutrients. They were related to Alcanivorax and Marinobacter strains, which are ubiquitous petroleum-hydrocarbon-degrading bacteria in marine environments, and to Oceanobacter kriegii (96.4-96.5 % similarities in almost full-length 16S rRNA gene sequences). The Oceanobacter-related bacteria showed high n-alkane-degrading activity, comparable to that of Alcanivorax borkumensis strain SK2. On the other hand, Alcanivorax strains exhibited high activity for branched-alkane degradation and thus could be key bacteria for branched-alkane biodegradation in tropical seas. Oceanobacter-related bacteria became most dominant in microcosms that simulated a crude oil spill event with Indonesian seawater. The dominance was observed in microcosms that were unamended or amended with fertilizer, suggesting that the Oceanobacter-related strains could become dominant in the natural tropical marine environment after an accidental oil spill, and would continue to dominate in the environment after biostimulation. These results suggest that Oceanobacter-related bacteria could be major degraders of petroleum n-alkanes spilt in the tropical sea. PMID:19541999

  13. Neutral chloroacetamide herbicide degradates and related compounds in Midwestern United States drinking water sources.

    PubMed

    Hladik, Michelle L; Bouwer, Edward J; Roberts, A Lynn

    2008-02-01

    Recent studies have revealed the presence of neutral degradates of chloroacetamide herbicides in the Chesapeake Bay at concentrations greatly in excess of the parent compounds. As some degradates are being considered for regulation in drinking water, exposure of human populations to such micropollutants is of interest. Here we report the results of a survey of source waters used by 12 drinking water utilities in the Midwestern United States. Analytes included 20 neutral and six ionic chloroacetamide degradates, four parent chloroacetamide herbicides, three triazine herbicides, and two triazine degradates. Samples were collected during Fall 2003 and Spring 2004. In the fall samples, 16 of 20 neutral chloroacetamide degradates were detected, while 18 of 20 neutral chloroacetamide degradates were detected in the spring samples. Concentrations of most parent chloroacetamides and neutral degradates were somewhat to substantially higher in the spring than in the fall, with median concentrations of approximately 10-100 ng/L. Groundwater sources tended to have lower concentrations of parents and neutral degradates than surface water sources in the fall, although concentrations of parents and degradates in groundwater were similar to those in surface water in the spring.

  14. Carnosine and Related Peptides: Therapeutic Potential in Age-Related Disorders

    PubMed Central

    Cararo, José H; Streck, Emilio L; Schuck, Patricia F; Ferreira, Gustavo da C

    2015-01-01

    Imidazole dipeptides (ID), such as carnosine (β-alanyl-L-histidine), are compounds widely distributed in excitable tissues of vertebrates. ID are also endowed of several biochemical properties in biological tissues, including antioxidant, bivalent metal ion chelating, proton buffering, and carbonyl scavenger activities. Furthermore, remarkable biological effects have been assigned to such compounds in age-related human disorders and in patients whose activity of serum carnosinase is deficient or undetectable. Nevertheless, the precise biological role of ID is still to be unraveled. In the present review we shall discuss some evidences from clinical and basic studies for the utilization of ID as a drug therapy for age-related human disorders. PMID:26425391

  15. Carnosine and Related Peptides: Therapeutic Potential in Age-Related Disorders.

    PubMed

    Cararo, José H; Streck, Emilio L; Schuck, Patricia F; Ferreira, Gustavo da C

    2015-09-01

    Imidazole dipeptides (ID), such as carnosine (β-alanyl-L-histidine), are compounds widely distributed in excitable tissues of vertebrates. ID are also endowed of several biochemical properties in biological tissues, including antioxidant, bivalent metal ion chelating, proton buffering, and carbonyl scavenger activities. Furthermore, remarkable biological effects have been assigned to such compounds in age-related human disorders and in patients whose activity of serum carnosinase is deficient or undetectable. Nevertheless, the precise biological role of ID is still to be unraveled. In the present review we shall discuss some evidences from clinical and basic studies for the utilization of ID as a drug therapy for age-related human disorders. PMID:26425391

  16. Effects of ageing and experimental diabetes on insulin-degrading enzyme expression in male rat tissues.

    PubMed

    Kochkina, Ekaterina G; Plesneva, Svetlana A; Vasilev, Dmitrii S; Zhuravin, Igor A; Turner, Anthony J; Nalivaeva, Natalia N

    2015-08-01

    Due to an increasing life expectancy in developing countries, cases of type 2 diabetes and Alzheimer's disease (AD) in the elderly are growing exponentially. Despite a causative link between diabetes and AD, general molecular mechanisms underlying pathogenesis of these disorders are still far from being understood. One of the factors leading to cell death and cognitive impairment characteristic of AD is accumulation in the brain of toxic aggregates of amyloid-β peptide (Aβ). In the normally functioning brain Aβ catabolism is regulated by a cohort of proteolytic enzymes including insulin-degrading enzyme (IDE) and their deficit with ageing can result in Aβ accumulation and increased risk of AD. The aim of this study was a comparative analysis of IDE expression in the brain structures involved in AD, as well as in peripheral organs (the liver and kidney) of rats, during natural ageing and after experimentally-induced diabetes. It was found that ageing is accompanied by a significant decrease of IDE mRNA and protein content in the liver (by 32 and 81%) and brain structures (in the cortex by 58 and 47% and in the striatum by 53 and 68%, respectively). In diabetic animals, IDE protein level was increased in the liver (by 36%) and in the striatum (by 42%) while in the brain cortex and hippocampus it was 20-30% lower than in control animals. No significant IDE protein changes were observed in the kidney of diabetic rats. These data testify that ageing and diabetes are accompanied by a deficit of IDE in the brain structures where accumulation of Aβ was reported in AD patients, which might be one of the factors predisposing to development of the sporadic form of AD in the elderly, and especially in diabetics.

  17. Age-Related and Heteroplasmy-Related Variation in Human mtDNA Copy Number

    PubMed Central

    Li, Mingkun; Madea, Burkhard; Stoneking, Mark

    2016-01-01

    The mitochondrial (mt) genome is present in many copies in human cells, and intra-individual variation in mtDNA sequences is known as heteroplasmy. Recent studies found that heteroplasmies are highly tissue-specific, site-specific, and allele-specific, however the functional implications have not been explored. This study investigates variation in mtDNA copy numbers (mtCN) in 12 different tissues obtained at autopsy from 152 individuals (ranging in age from 3 days to 96 years). Three different methods to estimate mtCN were compared: shotgun sequencing (in 4 tissues), capture-enriched sequencing (in 12 tissues) and droplet digital PCR (ddPCR, in 2 tissues). The highest precision in mtCN estimation was achieved using shotgun sequencing data. However, capture-enrichment data provide reliable estimates of relative (albeit not absolute) mtCNs. Comparisons of mtCN from different tissues of the same individual revealed that mtCNs in different tissues are, with few exceptions, uncorrelated. Hence, each tissue of an individual seems to regulate mtCN in a tissue-related rather than an individual-dependent manner. Skeletal muscle (SM) samples showed an age-related decrease in mtCN that was especially pronounced in males, while there was an age-related increase in mtCN for liver (LIV) samples. MtCN in SM samples was significantly negatively correlated with both the total number of heteroplasmic sites and with minor allele frequency (MAF) at two heteroplasmic sites, 408 and 16327. Heteroplasmies at both sites are highly specific for SM, accumulate with aging and are part of functional elements that regulate mtDNA replication. These data support the hypothesis that selection acting on these heteroplasmic sites is reducing mtCN in SM of older individuals. PMID:26978189

  18. Degradation mechanism of LiCoO2/mesocarbon microbeads battery based on accelerated aging tests

    NASA Astrophysics Data System (ADS)

    Guan, Ting; Zuo, Pengjian; Sun, Shun; Du, Chunyu; Zhang, Lingling; Cui, Yingzhi; Yang, Lijie; Gao, Yunzhi; Yin, Geping; Wang, Fuping

    2014-12-01

    A series of LiCoO2/mesocarbon microbeads (MCMB) commercial cells cycled at different rates (0.6C, 1.2C, 1.5C, 1.8C, 2.4C and 3.0C) are disassembled and the capacity fade mechanism is proposed by analyzing the structure, morphology and electrochemical performance evolution at the capacity retention of 95%, 90%, 85%, 80%. The capacity deterioration of the commercial cell is mainly caused by the decay of the reversible capacity of LiCoO2 cathode, the irreversible loss of active lithium and the lithium remaining in anode. The proportions of effects by the above three factors are calculated accurately. The consumption of the active lithium leads to a cell imbalance between the anode and the cathode. The electrochemical test results indicate that the capacity fade of the active materials at the low rate is more obvious than that at the high rate. The influence of the active lithium is gradually increscent with the increasing rate. The rate of 1.5C is the optimal value to accelerate the aging of the full cell by comparing the testing results at different capacity retentions in the specific condition of low charge/discharge rate and shallow depth of discharge.

  19. Age-Related Psychophysiological Vulnerability to Phenylalanine in Phenylketonuria

    PubMed Central

    Leuzzi, Vincenzo; Mannarelli, Daniela; Manti, Filippo; Pauletti, Caterina; Locuratolo, Nicoletta; Carducci, Carla; Carducci, Claudia; Vanacore, Nicola; Fattapposta, Francesco

    2014-01-01

    Background: Phenylketonuria (PKU) is caused by the inherited defect of the phenylalanine hydroxylase enzyme, which converts phenylalanine (Phe) into tyrosine (Tyr). Neonatal screening programs and early treatment have radically changed the natural history of PKU. Nevertheless, an increased risk of neurocognitive and psychiatric problems in adulthood remains a challenging aspect of the disease. In order to assess the vulnerability of complex skills to Phe, we explored: (a) the effect of a rapid increase in blood Phe levels on event-related potentials (ERP) in PKU subjects during their second decade of life; (b) the association (if existing) between psychophysiological and neurocognitive features. Methods: Seventeen early-treated PKU subjects, aged 10–20, underwent ERP [mismatch negativity, auditory P300, contingent negative variation (CNV), and Intensity Dependence of Auditory Evoked Potentials] recording before and 2 h after an oral loading of Phe. Neurocognitive functioning, historical and concurrent biochemical values of blood Phe, Tyr, and Phe/Tyr ratio, were all included in the statistical analysis. Results: Event-related potential components were normally detected in all the subjects. In subjects younger than 13 CNV amplitude, W2-CNV area, P3b latency, and reaction times in motor responses were negatively influenced by Phe-loading. Independently from the psychophysiological vulnerability, some neurocognitive skills were more impaired in younger patients. No correlation was found between biochemical alterations and neurocognitive and psychophysiological findings. Conclusion: The vulnerability of the emerging neurocognitive functions to Phe suggests a strict metabolic control in adolescents affected by PKU and a neurodevelopmental approach in the study of neurocognitive outcome in PKU. PMID:25003100

  20. Age-related changes in deformability of human erythrocytes.

    PubMed

    Sutera, S P; Gardner, R A; Boylan, C W; Carroll, G L; Chang, K C; Marvel, J S; Kilo, C; Gonen, B; Williamson, J R

    1985-02-01

    The present study was designed to further the characterization of age-related changes in the deformability of human erythrocytes. The top (approximately young) and bottom (approximately old) 10% fractions of density-separated red cells from ten normal donors were subjected to graded levels of shear stress in a rheoscope. Measurements were made of steady-state elongation (cells tank treading in a state of dynamic equilibrium) and the time course of shape recovery following abrupt cessation of shear. In parallel with the rheologic experiments, several physical and chemical properties were assayed to determine correlates of mechanical properties. These included mean cell volume, mean corpuscular hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane proteins, and membrane phospholipid and protein concentration. The microrheologic observations revealed that only about 90% of the old cells retained their capacity to tank tread. However, the tank-treading cells elongated less than their younger counterparts at corresponding levels of shear stress, thus demonstrating a reduced level of deformability. Further analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.

  1. Promising new treatments for neovascular age-related macular degeneration.

    PubMed

    Michels, Stephan; Schmidt-Erfurth, Ursula; Rosenfeld, Philip J

    2006-07-01

    Angiogenesis, the growth of new blood vessels from existing blood vessels, is responsible for vision loss in a variety of ophthalmic diseases. In neovascular age-related macular degeneration (AMD), the leading cause for legal blindness in many industrialised countries, abnormal blood vessels grow in the macula and cause blindness. There are a number of factors important in the angiogenic cascade but VEGF-A has been implicated in recent years as the major factor responsible for neovascular and exudative diseases of the eye. Numerous antiangiogenic drugs are in development but anti-VEGF drugs have shown great promise in treating neovascular AMD and other ocular diseases, and many of these drugs have been adopted from oncology where antiangiogenic therapy is gaining wide acceptance. For the first time in neovascular AMD, anti-VEGF drugs have brought the hope of vision improvement to a significant proportion of patients. This review provides an overview on angiogenic mechanisms, potential antiangiogenic treatment strategies and different antiangiogenic drugs with special focus on neovascular AMD.

  2. Radiation therapy for neovascular age-related macular degeneration

    PubMed Central

    Petrarca, Robert; Jackson, Timothy L

    2011-01-01

    Antivascular endothelial growth factor (anti-VEGF) therapies represent the standard of care for most patients presenting with neovascular (wet) age-related macular degeneration (neovascular AMD). Anti-VEGF drugs require repeated injections and impose a considerable burden of care, and not all patients respond. Radiation targets the proliferating cells that cause neovascular AMD, including fibroblastic, inflammatory, and endothelial cells. Two new neovascular AMD radiation treatments are being investigated: epimacular brachytherapy and stereotactic radiosurgery. Epimacular brachytherapy uses beta radiation, delivered to the lesion via a pars plana vitrectomy. Stereotactic radiosurgery uses low voltage X-rays in overlapping beams, directed onto the lesion. Feasibility data for epimacular brachytherapy show a greatly reduced need for anti-VEGF therapy, with a mean vision gain of 8.9 ETDRS letters at 12 months. Pivotal trials are underway (MERLOT, CABERNET). Preliminary stereotactic radiosurgery data suggest a mean vision gain of 8 to 10 ETDRS letters at 12 months. A large randomized sham controlled stereotactic radiosurgery feasibility study is underway (CLH002), with pivotal trials to follow. While it is too early to conclude on the safety and efficacy of epimacular brachytherapy and stereotactic radiosurgery, preliminary results are positive, and these suggest that radiation offers a more durable therapeutic effect than intraocular injections. PMID:21311657

  3. Automatic age-related macular degeneration detection and staging

    NASA Astrophysics Data System (ADS)

    van Grinsven, Mark J. J. P.; Lechanteur, Yara T. E.; van de Ven, Johannes P. H.; van Ginneken, Bram; Theelen, Thomas; Sánchez, Clara I.

    2013-03-01

    Age-related macular degeneration (AMD) is a degenerative disorder of the central part of the retina, which mainly affects older people and leads to permanent loss of vision in advanced stages of the disease. AMD grading of non-advanced AMD patients allows risk assessment for the development of advanced AMD and enables timely treatment of patients, to prevent vision loss. AMD grading is currently performed manually on color fundus images, which is time consuming and expensive. In this paper, we propose a supervised classification method to distinguish patients at high risk to develop advanced AMD from low risk patients and provide an exact AMD stage determination. The method is based on the analysis of the number and size of drusen on color fundus images, as drusen are the early characteristics of AMD. An automatic drusen detection algorithm is used to detect all drusen. A weighted histogram of the detected drusen is constructed to summarize the drusen extension and size and fed into a random forest classifier in order to separate low risk from high risk patients and to allow exact AMD stage determination. Experiments showed that the proposed method achieved similar performance as human observers in distinguishing low risk from high risk AMD patients, obtaining areas under the Receiver Operating Characteristic curve of 0.929 and 0.934. A weighted kappa agreement of 0.641 and 0.622 versus two observers were obtained for AMD stage evaluation. Our method allows for quick and reliable AMD staging at low costs.

  4. Age-related hearing loss increases cross-modal distractibility.

    PubMed

    Puschmann, Sebastian; Sandmann, Pascale; Bendixen, Alexandra; Thiel, Christiane M

    2014-10-01

    Recent electrophysiological studies have provided evidence that changes in multisensory processing in auditory cortex cannot only be observed following extensive hearing loss, but also in moderately hearing-impaired subjects. How the reduced auditory input affects audio-visual interactions is however largely unknown. Here we used a cross-modal distraction paradigm to investigate multisensory processing in elderly participants with an age-related high-frequency hearing loss as compared to young and elderly subjects with normal hearing. During the experiment, participants were simultaneously presented with independent streams of auditory and visual input and were asked to categorize either the auditory or visual information while ignoring the other modality. Unisensory sequences without any cross-modal input served as control conditions to assure that all participants were able to perform the task. While all groups performed similarly in these unisensory conditions, hearing-impaired participants showed significantly increased error rates when confronted with distracting cross-modal stimulation. This effect could be observed in both the auditory and the visual task. Supporting these findings, an additional regression analysis indicted that the degree of high-frequency hearing loss significantly modulates cross-modal visual distractibility in the auditory task. These findings provide new evidence that already a moderate sub-clinical hearing loss, a common phenomenon in the elderly population, affects the processing of audio-visual information.

  5. Seven New Loci Associated with Age-Related Macular Degeneration

    PubMed Central

    2013-01-01

    Age-related macular degeneration (AMD) is a common cause of blindness in older individuals. To accelerate understanding of AMD biology and help design new therapies, we executed a collaborative genomewide association study, examining >17,100 advanced AMD cases and >60,000 controls of European and Asian ancestry. We identified 19 genomic loci associated with AMD with p<5×10−8 and enriched for genes involved in regulation of complement activity, lipid metabolism, extracellular matrix remodeling and angiogenesis. Our results include 7 loci reaching p<5×10−8 for the first time, near the genes COL8A1/FILIP1L, IER3/DDR1, SLC16A8, TGFBR1, RAD51B, ADAMTS9/MIR548A2, and B3GALTL. A genetic risk score combining SNPs from all loci displayed similar good ability to distinguish cases and controls in all samples examined. Our findings provide new directions for biological, genetic and therapeutic studies of AMD. PMID:23455636

  6. Cutaneous vascular responses and thermoregulation in relation to age.

    PubMed

    Khan, F; Spence, V A; Belch, J J

    1992-05-01

    1. Sympathetic vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge were assessed in fingertip skin in relation to age and were correlated with vasoconstrictor ability during body cooling. The above relationship was also examined in diabetic patients in whom vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge had been shown previously to be markedly impaired. 2. Vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge, measured by laser Doppler flowmetry, were significantly reduced in the elderly group, although individual responses varied from normal to absent, and they also had a considerably greater variability as measured on three separate occasions than seen in young subjects. Discriminant analysis showed that, from each of three occasions, 65% of vasoconstrictor responses were abnormal in the elderly group. 3. Body cooling was performed by reducing the environmental temperature from 40 degrees C to 12 degrees C, and the time taken for blood flow to fall to 75%, 50% and 25% of the pre-cooling level (VC75, VC50, VC25, respectively) was calculated. Vasoconstriction was rapid in young subjects and was consistent with good vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge. In the elderly group, vasoconstriction was slower, but only the VC25 value differed significantly [elderly group, 13.3 (7.9-31.0) min, young group, 5.7 (2.7-15.5) min; median (interquartile range); P less than 0.05].(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1317761

  7. Promising new treatments for neovascular age-related macular degeneration.

    PubMed

    Michels, Stephan; Schmidt-Erfurth, Ursula; Rosenfeld, Philip J

    2006-07-01

    Angiogenesis, the growth of new blood vessels from existing blood vessels, is responsible for vision loss in a variety of ophthalmic diseases. In neovascular age-related macular degeneration (AMD), the leading cause for legal blindness in many industrialised countries, abnormal blood vessels grow in the macula and cause blindness. There are a number of factors important in the angiogenic cascade but VEGF-A has been implicated in recent years as the major factor responsible for neovascular and exudative diseases of the eye. Numerous antiangiogenic drugs are in development but anti-VEGF drugs have shown great promise in treating neovascular AMD and other ocular diseases, and many of these drugs have been adopted from oncology where antiangiogenic therapy is gaining wide acceptance. For the first time in neovascular AMD, anti-VEGF drugs have brought the hope of vision improvement to a significant proportion of patients. This review provides an overview on angiogenic mechanisms, potential antiangiogenic treatment strategies and different antiangiogenic drugs with special focus on neovascular AMD. PMID:16787141

  8. Age-related macular degeneration: experimental and emerging treatments

    PubMed Central

    Hubschman, Jean Pierre; Reddy, Shantan; Schwartz, Steven D

    2009-01-01

    Purpose: This essay reviews the experimental treatments and new imaging modalities that are currently being explored by investigators to help treat patients with age-related macular degeneration (AMD). Design: Interpretative essay. Methods: Literature review and interpretation. Results: Experimental treatments to preserve vision in patients with exudative AMD include blocking vascular endothelial growth factor (VEGF), binding VEGF, and modulating the VEGF receptors. Investigators are also attempting to block signal transduction with receptor tyrosine kinase inhibitors. Experimental treatments for non-exudative AMD include agents that target inflammation, oxidative stress, and implement immune-modulation. The effectiveness of these newer pharmacologic agents has the potential to grow exponentially when used in combination with new and improved imaging modalities that can help identify disease earlier and follow treatment response more precisely. Conclusion: With a better understanding, at the genetic and molecular level, of AMD and the development of superior imaging modalities, investigators are able to offer treatment options that may offer unprecedented visual gains while reducing the need for repetitive treatments. PMID:19668561

  9. Temperature-related degradation and colour changes of historic paintings containing vivianite.

    PubMed

    Čermáková, Zdeňka; Švarcová, Silvie; Hradilová, Janka; Bezdička, Petr; Lančok, Adriana; Vašutová, Vlasta; Blažek, Jan; Hradil, David

    2015-04-01

    Temperature-related degradation of pure synthetic as well as partly oxidised natural vivianite has been studied by high-temperature X-ray diffraction (HT-XRD) covering the whole extent of the temperature-related stability of its structure. While temperatures around 70°C are already damaging to vivianite, exposition to 160°C results in complete amorphisation of both the vivianite and its oxidation products. As indicated by Mössbauer spectroscopy, temperature-induced oxidation of vivianite starts at 90°C. To study the occurring structural as well as accompanying colour changes in more detail, model vivianite paint layer samples with different historic binders were prepared and subjected to increased temperatures. Exposition to 80°C caused pronounced colour changes of all the samples: ground natural blue vivianite became grey--a colour change which has been described in actual works of art. Regarding the binders, the oil seemed to facilitate the transfer of heat to vivianite's grains. To simulate conditions of conservation treatment under which the painting is exposed to increased temperatures, oil-on-canvas mock-ups with vivianite were prepared and relined in a traditional way using iron. The treatment affected preferentially larger grains of vivianite; the micro-samples documented their change to grey, and their Raman spectra showed the change from vivianite to metavivianite.

  10. Primary age-related tauopathy (PART): a common pathology associated with human aging

    PubMed Central

    Crary, John F.; Trojanowski, John Q.; Schneider, Julie A.; Abisambra, Jose F.; Abner, Erin L.; Alafuzoff, Irina; Arnold, Steven E.; Attems, Johannes; Beach, Thomas G.; Bigio, Eileen H.; Cairns, Nigel J.; Dickson, Dennis W.; Gearing, Marla; Grinberg, Lea T.; Hof, Patrick R.; Hyman, Bradley T.; Jellinger, Kurt; Jicha, Gregory A.; Kovacs, Gabor G.; Knopman, David S.; Kofler, Julia; Kukull, Walter A.; Mackenzie, Ian R.; Masliah, Eliezer; McKee, Ann; Montine, Thomas J.; Murray, Melissa E.; Neltner, Janna H.; Santa-Maria, Ismael; Seeley, William W.; Serrano-Pozo, Alberto; Shelanski, Michael L.; Stein, Thor; Takao, Masaki; Thal, Dietmar R.; Toledo, Jonathan B.; Troncoso, Juan C.; Vonsattel, Jean Paul; White, Charles L.; Wisniewski, Thomas; Woltjer, Randall L.; Yamada, Masahito; Nelson, Peter T.

    2014-01-01

    We recommend a new term, “primary age-related tauopathy” (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFT) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aβ) plaques. For these “NFT+/Aβ−” brains, for which formal criteria for AD neuropathologic changes are not met, the NFT are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as “tangle-only dementia” and “tangle-predominant senile dementia”, are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aβ accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed. PMID:25348064

  11. Age-Related Evolution Patterns in Online Handwriting

    PubMed Central

    2016-01-01

    Characterizing age from handwriting (HW) has important applications, as it is key to distinguishing normal HW evolution with age from abnormal HW change, potentially triggered by neurodegenerative decline. We propose, in this work, an original approach for online HW style characterization based on a two-level clustering scheme. The first level generates writer-independent word clusters from raw spatial-dynamic HW information. At the second level, each writer's words are converted into a Bag of Prototype Words that is augmented by an interword stability measure. This two-level HW style representation is input to an unsupervised learning technique, aiming at uncovering HW style categories and their correlation with age. To assess the effectiveness of our approach, we propose information theoretic measures to quantify the gain on age information from each clustering layer. We have carried out extensive experiments on a large public online HW database, augmented by HW samples acquired at Broca Hospital in Paris from people mostly between 60 and 85 years old. Unlike previous works claiming that there is only one pattern of HW change with age, our study reveals three major aging HW styles, one specific to aged people and the two others shared by other age groups. PMID:27752277

  12. Localizing Age-Related Individual Differences in a Hierarchical Structure

    ERIC Educational Resources Information Center

    Salthouse, Timothy A.

    2004-01-01

    Data from 33 separate studies were combined to create an aggregate data set consisting of 16 cognitive variables and 6832 different individuals who ranged between 18 and 95 years of age. Analyses were conducted to determine where in a hierarchical structure of cognitive abilities individual differences associated with age, gender, education, and…

  13. Modeling the mechanical behavior of vertebral trabecular bone: effects of age-related changes in microstructure.

    PubMed

    Silva, M J; Gibson, L J

    1997-08-01

    Age-related reductions in the thickness and number of trabeculae in vertebral trabecular bone have been documented by several workers, yet the relative effects of these changes on mechanical properties are not known. We developed a two-dimensional model of human vertebral trabecular bone and investigated its mechanical behavior using finite element analysis. The stress-strain behavior, failure mode, and strain distributions predicted using the model were consistent with those observed for vertebral trabecular bone under compressive loading. Random reductions in the number of trabeculae reduced the modulus and strength of the models two to five times more than uniform reductions in the thickness of trabeculae that caused the same loss of bone volume. For example, randomly removing longitudinal trabeculae to achieve a reduction in density of 10% reduced the strength by approximately 70%, whereas removing the same amount of bone by uniformly reducing the thickness of the longitudinal trabeculae only reduced the strength by approximately 20%. For a simulation of aged bone, in which the thickness and number of trabeculae were reduced concurrently, the strength was 23% of its intact ("young") value. When the bone mass of the aged model was restored to its intact level by increasing the thickness but not the number of trabeculae, the strength increased by 60%, but was still only 37% of its intact value. These combined findings, based on a two-dimensional, idealized model of vertebral trabecular bone, illustrate the importance of maintaining trabecular number and suggest that it may not be possible to restore bone strength following a period of advanced bone loss if a substantial number of trabeculae have been resorbed. Thus, until treatments exist that can increase trabecular number, the most effective treatment strategy is to prevent the degradation of bone strength by maintaining the number of trabeculae at a healthy level.

  14. Age-related changes in mucins from human whole saliva.

    PubMed

    Denny, P C; Denny, P A; Klauser, D K; Hong, S H; Navazesh, M; Tabak, L A

    1991-10-01

    The predominant mucins in human whole saliva, MG1 and MG2, serve to protect and to lubricate the oral cavity. In this study, both unstimulated and stimulated whole salivas were collected from two groups of subjects: young (18-35 years of age) and aged (65-83 years of age). The subjects were in apparent good health. Saliva samples from each subject were analyzed by SDS-PAGE. The gels were stained with Stains-all, and both MG1 and MG2 were quantitated by video-image densitometry. The protocol gave reproducible values for each mucin. The stimulated and unstimulated salivas from aged subjects showed significant reductions in concentrations of both MG1 and MG2, as quantitated in mucin dye-binding units. Possible associations of these reductions with the aging process are discussed. PMID:1719051

  15. Age-related changes in mucins from human whole saliva.

    PubMed

    Denny, P C; Denny, P A; Klauser, D K; Hong, S H; Navazesh, M; Tabak, L A

    1991-10-01

    The predominant mucins in human whole saliva, MG1 and MG2, serve to protect and to lubricate the oral cavity. In this study, both unstimulated and stimulated whole salivas were collected from two groups of subjects: young (18-35 years of age) and aged (65-83 years of age). The subjects were in apparent good health. Saliva samples from each subject were analyzed by SDS-PAGE. The gels were stained with Stains-all, and both MG1 and MG2 were quantitated by video-image densitometry. The protocol gave reproducible values for each mucin. The stimulated and unstimulated salivas from aged subjects showed significant reductions in concentrations of both MG1 and MG2, as quantitated in mucin dye-binding units. Possible associations of these reductions with the aging process are discussed.

  16. Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents.

    PubMed

    Ballak, Sam B; Degens, Hans; de Haan, Arnold; Jaspers, Richard T

    2014-03-01

    Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men.

  17. Ages of legal importance: Implications in relation to birth registration and age assessment practices.

    PubMed

    Jayaraman, Jayakumar; Roberts, Graham J; Wong, Hai Ming; McDonald, Fraser; King, Nigel M

    2016-01-01

    Assessment of age is a common procedure routinely conducted in many countries following birth date disputes, particularly following asylum claims and criminal offenses. UNICEF reports that only 65% of children in the world were registered, and the numbers of children who possess an authentic birth certificate were significantly lower than those registered. Legally important ages can be categorized into defined age ranges that vary among different countries. Recently, following an increase in the number of age-specific crimes, many countries have revised their legally important ages. This article is intended to report the most recent data on the ages of legal importance in the major countries of the world and implicate its relevance to birth registration and age assessment practices. PMID:26101440

  18. New Treatment Greatly Improves Prognosis for Patients with AMD (Age-Related Macular Degeneration)

    MedlinePlus

    ... turn JavaScript on. Feature: Age-related Macular Degeneration New Treatment Greatly Improves Prognosis for Patients with AMD ... Eye Institute Photo Courtesy of: NEI In a new study of nearly 650 people with age-related ...

  19. Stability and degradation of organic photovoltaics fabricated, aged, and characterized by the ISOS 3 inter-laboratory collaboration

    NASA Astrophysics Data System (ADS)

    Tanenbaum, David M.; Hermenau, Martin; Voroshazi, Eszter; Lloyd, Matthew T.; Galagan, Yulia; Zimmermann, Birger; Hösel, Markus; Dam, Henrik F.; Jørgensen, Mikkel; Gevorgyan, Suren; Kudret, Suleyman; Maes, Wouter; Lutsen, Laurence; Vanderzande, Dirk; Würfel, Uli; Andriessen, Ronn; Rösch, Roland; Hoppe, Harald; Lira-Cantu, Monica; Teran-Escobar, Gerardo; Dupuis, Aurélie; Bussière, Pierre-Olivier; Rivaton, Agnès.; Uzunoglu, Gülsah Y.; Germack, David; Andreasen, Birgitta; Madsen, Morten V.; Norrman, Kion; Bundgaard, Eva; Krebs, Frederik C.

    2012-09-01

    Seven distinct sets (n >= 12) of state of the art organic photovoltaic devices were prepared by leading research laboratories in a collaboration planned at the Third International Summit on Organic Photovoltaic Stability (ISOS-3). All devices were shipped to DTU and characterized simultaneously up to 1830 h in accordance with established ISOS-3 protocols under three distinct illumination conditions: accelerated full sun simulation; low level indoor fluorescent lighting; and dark storage with daily measurement under full sun simulation. Three nominally identical devices were used in each experiment both to provide an assessment of the homogeneity of the samples and to distribute samples for a variety of post soaking analytical measurements at six distinct laboratories enabling comparison at various stages in the degradation of the devices. Characterization includes current-voltage curves, light beam induced current (LBIC) imaging, dark lock-in thermography (DLIT), photoluminescence (PL), electroluminescence (EL), in situ incident photon-to-electron conversion efficiency (IPCE), time of flight secondary ion mass spectrometry (TOF-SIMS), cross sectional electron microscopy (SEM), UV visible spectroscopy, fluorescence microscopy, and atomic force microscopy (AFM). Over 100 devices with more than 300 cells were used in the study. We present here design of the device sets, results both on individual devices and uniformity of device sets from the wide range of characterization methods applied at different stages of aging under the three illumination conditions. We will discuss how these data can help elucidate the degradation mechanisms as well as the benefits and challenges associated with the unprecedented size of the collaboration.

  20. Age-related changes in genomic stability of horses.

    PubMed

    Wnuk, Maciej; Bugno-Poniewierska, Monika; Lewinska, Anna; Oklejewicz, Bernadetta; Zabek, Tomasz; Bartosz, Grzegorz; Słota, Ewa

    2011-05-01

    Recently, the old horse has been proposed as a model to study telomere-dependent senescence, immunosenescence and inflamm-aging. In the present paper, we used 80 Hucul and Anglo-Arabian horses divided into 3 age groups (juvenile, adult, old) to evaluate age-dependent changes at the genomic and DNA level and in cell proliferative potential. The level of positive TUNEL cells (both apoptotic and with DNA fragmentation), oxidative DNA damage (8-oxoG immunostaining), sister chromatid exchange and bleomycin-induced chromatid breaks were significantly increased in the combined old group compared to the combined adult group. We observed a negative correlation between micronuclei formation and age, which may be associated with damaged cells undergoing apoptosis, rather than expressing micronuclei. We were unable to show any significant changes in the nuclear division index value, which reflects the proliferative status of the viable cell fraction during aging. Here, we show that breed-independent and age-associated changes in genomic stability may contribute, at least in part, to the aging process in the horse. PMID:21557962