39 research outputs found

    The COMT p.Val158Met Polymorphism and Cognitive Performance in Adult Development, Healthy Aging and Mild Cognitive Impairment

    Get PDF
    Background: The impact of genetic polymorphisms on cognition is assumed to increase with age as losses of brain resources have to be compensated for. We investigate the relation of catechol-O-methyltransferase (COMT) p.Val158Met polymorphism and cognitive capacity in the course of adult development, healthy aging and the development of mild cognitive impairment (MCI) in two birth cohorts of subjects born between 1930 and 1932 or between 1950 and 1952. Methods: Thorough neuropsychological assessment was conducted in a total of 587 participants across three examination waves between 1993 and 2008. The COMT genotype was determined as a restriction fragment length polymorphism after PCR amplification and digestion with Nla III. Results: Significant effects of the COMT p.Val158Met polymorphism were identified for attention and cognitive flexibility in the younger but not the older cohort. Conclusion: These results confirm the importance of the COMT p.Val158Met genotype on tasks assessing attention and cognitive flexibility in midlife but not in healthy aging and the development of MCI. Our findings suggest that the influence of COMT changes as a function of age, decreasing from midlife to aging

    Perplexity – a new predictor of cognitive changes in spoken language? – results of the Interdisciplinary Longitudinal Study on Adult Development and Aging (ILSE)

    Get PDF
    Abstract: In addition to memory loss, progressive deterioration of speech and language skills is among the main symptoms at the onset of Alzheimer’s disease (AD) as well as in mild cognitive impairment (MCI). Detailed interview analyses demonstrated early symptoms years before the onset of AD/MCI. Automatic speech processing could be a promising approach to identifying underlying mechanisms in larger studies or even support diagnostics. Perplexity as a measure of predictability of text could be a sensitive indicator of cognitive deterioration. Therefore, voice recordings from the Interdisciplinary Longitudinal Study on Adult Development and Aging were analyzed with regard to neuropsychological parameters in participants that develop MCI/AD or remain cognitively healthy. Preliminary results indicate that perplexity predicts severity of cognitive deficits and information processing speed obtained 10–12 years later in participants who developed MCI/AD in contrast to those who stayed healthy. Findings support the heuristic value of research on the diagnostic potential of automatic speech processing

    Maximum Photosynthetic Yield of Green Microalgae in Photobioreactors

    Get PDF
    The biomass yield on light energy of Dunaliella tertiolecta and Chlorella sorokiniana was investigated in a 1.25- and 2.15-cm light path panel photobioreactor at constant ingoing photon flux density (930 µmol photons m−2 s−1). At the optimal combination of biomass density and dilution rate, equal biomass yields on light energy were observed for both light paths for both microalgae. The observed biomass yield on light energy appeared to be based on a constant intrinsic biomass yield and a constant maintenance energy requirement per gram biomass. Using the model of Pirt (New Phytol 102:3–37, 1986), a biomass yield on light energy of 0.78 and 0.75 g mol photons−1 and a maintenance requirement of 0.0133 and 0.0068 mol photons g−1 h−1 were found for D. tertiolecta and C. sorokiniana, respectively. The observed yield decreases steeply at low light supply rates, and according to this model, this is related to the increase of the amount of useable light energy diverted to biomass maintenance. With this study, we demonstrated that the observed biomass yield on light in short light path bioreactors at high biomass densities decreases because maintenance requirements are relatively high at these conditions. All our experimental data for the two strains tested could be described by the physiological models of Pirt (New Phytol 102:3–37, 1986). Consequently, for the design of a photobioreactor, we should maintain a relatively high specific light supply rate. A process with high biomass densities and high yields at high light intensities can only be obtained in short light path photobioreactors

    Sonate, für Altblockflöte (Querflöte, Oboe, Violine) und Basso continuo

    No full text
    "Edition Schott." --- For recorder (or flute, oboe, or violin) and continuo; unfigured bass realized for keyboard instrument; includes part for violincello (or viola da gamba). --- Stamp on cover: Available from: European American Music Distributors Corp., Clifton, New Jersey. --- Edited from a ms. in the Mecklenburgische Landesbibliothek, Schwerin. --- Postface in German, French, and English. Digital images made available during the final 20 years of US copyright in accordance with the Digital Millennium Copyright Act

    Differences in Cognitive Functioning in Two Birth Cohorts Born 20 Years Apart: Data from the Interdisciplinary Longitudinal Study of Ageing

    No full text
    We compared neuropsychological functioning and prevalence of mild cognitive impairment (MCI) in two birth cohorts born 20 years apart when participants had reached the same age, i.e., the mid-60s. The study followed up 500 volunteers born 1930–1932 (C30) and 502 born 1950–1952 (C50). Participants underwent medical, neuropsychological, and psychiatric examinations in 1993–1996 (T1), 1997–2000 (T2), 2005–2008 (T3), and 2014–2016 (T4), including assessment of abstract thinking, memory performance, verbal fluency, visuo-spatial thinking, psychomotor speed, and attention. Healthy participants from C30 at T2 (n = 298) and from C50 at T4 (n = 205) were compared using multivariate ANCOVAs. Groups slightly differed with respect to age (C50: 63.86 ± 1.14 vs. C30: 66.80 ± 0.91; p < 0.05) and years of education (13.28 ± 2.89 vs. 14.56 ± 2.45). After correcting for age, C50 significantly outperformed C30 in all domains except concentration and verbal fluency. After additionally adjusting for education, C50 significantly outperformed C30 in declarative memory performances and abstract thinking only. Prevalence rates of MCI were 25.2% in C30 and 9.6% in C50 (p < 0.001). Our findings confirm the association between better educational attainment and enhanced cognitive performance in “younger” old individuals. While this association corresponds to the Flynn effect, various life course influences may have also contributed to better performance, including improvements in healthcare provision, medication, and lifestyle factors. Their overall effects may foster cognitive reserve and thus translate into the decline in MCI prevalence reported here

    Development of advanced methods and related software for human reliability evaluation within probabilistic safety analyses

    No full text
    Human Reliability Analysis (HRA) is an important part of Probabilistic Safety Analysis (PSA). The first part of this report consists of an overview of types of human behaviour and human error including the effect of significant performance shaping factors on human reliability. Particularly with regard to safety assessments for nuclear power plants a lot of HRA merhods have been developed. The most imortant of these methods are presented and discussed in the report, together with techniques for incorporating HRA into PSA and with models of operator cognitive behaviour. Based on existing HRA methods the concept of a software system is described. For the development of this system the utilization of modern programmig tools is proposed; the essential goal is th effective application of HRA methods. A possible integration of computeraided HRA within PSA is discussed. The features of Expert System Technology and examplas of applications (PSA, HRA) are presented in four appendices

    The COMT p.Val158Met Polymorphism and Cognitive Performance in Adult Development, Healthy Aging and Mild Cognitive Impairment

    Get PDF
    Background: The impact of genetic polymorphisms on cognition is assumed to increase with age as losses of brain resources have to be compensated for. We investigate the relation of catechol-O-methyltransferase (COMT) p.Val158Met polymorphism and cognitive capacity in the course of adult development, healthy aging and the development of mild cognitive impairment (MCI) in two birth cohorts of subjects born between 1930 and 1932 or between 1950 and 1952. Methods: Thorough neuropsychological assessment was conducted in a total of 587 participants across three examination waves between 1993 and 2008. The COMT genotype was determined as a restriction fragment length polymorphism after PCR amplification and digestion with Nla III. Results: Significant effects of the COMT p.Val158Met polymorphism were identified for attention and cognitive flexibility in the younger but not the older cohort. Conclusion: These results confirm the importance of the COMT p.Val158Met genotype on tasks assessing attention and cognitive flexibility in midlife but not in healthy aging and the development of MCI. Our findings suggest that the influence of COMT changes as a function of age, decreasing from midlife to aging
    corecore