149 research outputs found

    Stability and Change of Neuroticism in Aging

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    Data from the Longitudinal Aging Study Amsterdam were used to study the relationship between neuroticism and aging. At baseline, cross-sectional analyses of data from 2,117 respondents (aged 55–85 years, M = 70) showed no significant age differences. The magnitude of the 3- and 6-year stability coefficients was high, and 12% of the elderly participants showed a clinically relevant mean level change. Longitudinal multilevel analyses showed a small but statistical significant change with aging, but the mean change was not considered clinically relevant. A U-formed course was found, showing a slight decrease until respondents reached the age of 70. Adjusting the model for physical health-related variables slightly increased the stability. An additional interaction analysis showed that the individual trajectory of neuroticism was not affected by the physical health status. In conclusion, neuroticism remains rather stable in middle and older adulthood, with some apparent increase in late life

    Asymptotic and numerical analysis of a simple model for blade coating

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    Motivated by the industrial process of blade coating, the two-dimensional flow of a thin film of Newtonian fluid on a horizontal substrate moving parallel to itself with constant speed under a fixed blade of finite length in which the flows upstream and downstream of the blade are coupled via the flow under the blade is analysed. A combination of asymptotic and numerical methods is used to investigate the number and nature of the steady solutions that exist. Specially, it is found that in the presence of gravity there is always at least one, and (depending on the parameter values) possibly as many as three, steady solutions, and that when multiple solutions occur they are identical under and downstream of the blade, but differ upstream of it. The stability of these solutions is investigated, and their asymptotic behaviour in the limits of large and small flux and weak and strong gravity effects, respectively, determined

    CBR model for the intelligent management of customer support centers

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    [EN] In this paper, a new CBR system for Technology Management Centers is presented. The system helps the staff of the centers to solve customer problems by finding solutions successfully applied to similar problems experienced in the past. This improves the satisfaction of customers and ensures a good reputation for the company who manages the center and thus, it may increase its profits. The CBR system is portable, flexible and multi-domain. It is implemented as a module of a help-desk application to make the CBR system as independent as possible of any change in the help-desk. Each phase of the reasoning cycle is implemented as a series of configurable plugins, making the CBR module easy to update and maintain. This system has been introduced and tested in a real Technology Management center ran by the Spanish company TISSAT S.A.Financial support from Spanish government under grant PROFIT FIT-340001-2004-11 is gratefully acknowledgeHeras BarberΓ‘, SM.; Garcia Pardo Gimenez De Los Galanes, JA.; Ramos-Garijo Font De Mora, R.; Palomares Chust, A.; Julian Inglada, VJ.; Rebollo Pedruelo, M.; Botti, V. (2006). CBR model for the intelligent management of customer support centers. En Lecture Notes in Computer Science. Springer Verlag (Germany). 663-670. https://doi.org/10.1007/11875581_80S663670Acorn, T., Walden, S.: SMART: SupportManagement Automated Reasoning Technology for Compaq Customer Service. In: Scott, A., Klahr, P. (eds.) Proceedings of the 2 International Conference on Intelligent Tutoring Systems, ITS-92 Berlin, vol.Β 4, pp. 3–18. AAAI Press, Menlo Park (1992)Simoudis, E.: Using Case-Based Retrieval for Customer Technical Support. IEEE Intelligent SystemsΒ 7, 10–12 (1992)Kriegsman, M., Barletta, R.: Building a Case-Based Help Desk Application. IEEE Expert: Intelligent Systems and Their ApplicationsΒ 8, 18–26 (1993)Shimazu, H., Shibata, A., Nihei, K.: Case-Based Retrieval Interface Adapted to Customer-Initiated Dialogues in Help Desk Operations. In: Mylopoulos, J., Reiter, R. (eds.) Proceedings of the 12th National Conference on Artificial Intelligence, vol.Β 1, pp. 513–518. AAAI Press, Menlo Park (1994)Raman, R., Chang, K.H., Carlisle, W.H., Cross, J.H.: A self-improving helpdesk service system using case-based reasoning techniques. Computers in IndustryΒ 2, 113–125 (1996)Kang, B.H., Yoshida, K., Motoda, H., Compton, P.: Help Desk System with Intelligent Interface. Applied Artificial IntelligenceΒ 11, 611–631 (1997)Roth-Berghofer, T., Iglezakis, I.: Developing an Integrated Multilevel Help-Desk Support System. In: Proceedings of the 8th German Workshop on Case-Based Reasoning, pp. 145–155 (2000)Goker, M., Roth-Berghofer, T.: The development and utilization of the case-based help-desk support system HOMER. Engineering Applications of Artificial IntelligenceΒ 12, 665–680 (1999)Roth-Berghofer, T.R.: Learning from HOMER, a case-based help-desk support system. In: Melnik, G., Holz, H. (eds.) Advances in Learning Software Organizations, pp. 88–97. Springer, Heidelberg (2004)Bergmann, R., Althoff, K.D., Breen, S., GΓΆker, M., Manago, M., TraphΓΆner, R., Wess, S.: Developing Industrial Case-Based Reasoning Applications. In: The INRECA Methodology, 2nd edn. LNCS (LNAI), vol.Β 1612. Springer, Heidelberg (2003)eGain (2006), http://www.egain.comKaidara Software Corporation (2006), http://www.kaidara.com/Empolis Knowledge Management GmbH - Arvato AG (2006), http://www.empolis.com/Althoff, K.D., Auriol, E., Barletta, R., Manago, M.: A Review of Industrial Case-Based Reasoning Tools. AI Perspectives Report. Goodall, A., Oxford (1995)Watson, I.: Applying Case-Based Reasoning. Techniques for Enterprise Systems. Morgan Kaufmann Publishers, Inc. California (1997)empolis: empolis Orenge Technology Whitepaper. Technical report, empolis GmbH (2002)Tissat, S.A. (2006), http://www.tissat.esGiraud-Carrier, C., Martinez, T.R.: An integrated framework for learning and reasoning. Journal of Artificial Intelligence ResearchΒ 3, 147–185 (1995)Corchado, J.M., Borrajo, M.L., Pellicer, M.A., Yanez, J.C.: Neuro-symbolic system for Business Internal Control. In: Perner, P. (ed.) ICDM 2004. LNCS (LNAI), vol.Β 3275, pp. 1–10. Springer, Heidelberg (2004)Aamodt, A., Plaza, E.: Case-based reasoning: foundational issues, methodological variations and system approaches. AI CommunicationsΒ 7(1), 39–59 (1994)Tversky, A.: Features of similarity. Psychological ReviewΒ 84(4), 327–352 (1997

    Utilization of acute and long-term care in the last year of life: comparison with survivors in a population-based study

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    Background. It is well-known that the use of care services is most intensive in the last phase of life. However, so far only a few determinants of end-of-life care utilization are known. The aims of this study were to describe the utilization of acute and long-term care among older adults in their last year of life as compared to those not in their last year of life, and to examine which of a broad range of determinants can account for observed differences in care utilization. Methods. Data were used from the Longitudinal Aging Study Amsterdam (LASA). In a random, age and sex stratified population-based cohort of 3107 persons aged 55 ? 85 years at baseline and representative of the Netherlands, follow-up cycles took place at 3, 6 and 9 years. Those who died within one year directly after a cycle were defined as the "end-of-life group" (n = 262), and those who survived at least three years after a cycle were defined as the "survivors". Utilization of acute and long-term care services, including professional and informal care, were recorded at each cycle, as well as a broad range of health-related and psychosocial variables. Results. The end-of-life group used more care than the survivors. In the younger-old this difference was most pronounced for acute care, and in the older-old, for long-term care. Use of both acute and long-term home care in the last year of life was fully accounted for by health problems. Use of institutional care at the end of life was partly accounted for by health problems, but was not fully explained by the determinants included. Conclusion. This study shows that severity of health problems are decisive in the explanation of the increase in use of care services towards the end-of-life. This information is essential for an appropriate allocation of professional health care to the benefit of older persons themselves and their informal caregivers. Β© 2009 Pot et al; licensee BioMed Central Ltd

    Low Mid-Upper Arm Circumference, Calf Circumference, and Body Mass Index and Mortality in Older Persons

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    Background.Low body mass index is a general measure of thinness. However, its measurement can be cumbersome in older persons and other simple anthropometric measures may be more strongly associated with mortality. Therefore, associations of low mid-upper arm circumference, calf circumference, and body mass index with mortality were examined in older persons.Methods.Data of the Longitudinal Aging Study Amsterdam, a population-based cohort study in the Netherlands, were used. The present study included community-dwelling persons 65 years and older in 1992-1993 (n = 1,667), who were followed until 2007 for their vital status. Associations between anthropometric measures and 15-year mortality were examined by spline regression models and, below the nadir, Cox regression models, transforming all measures to sex-specific Z scores.Results.Mortality rates were 599 of 826 (73%) in men and 479 of 841 (57%) in women. Below the nadir, the hazard ratio of mortality per 1 standard deviation lower mid-upper arm circumference was 1.79 (95% confidence interval, 1.48-2.16) in men and 2.26 (1.71-3.00) in women. For calf circumference, the hazard ratio was 1.45 (1.22-1.71) in men and 1.30 (1.15-1.48) in women and for body mass index 1.38 (1.17-1.61) in men and 1.56 (1.10-2.21) in women. Excluding deaths within the first 3 years after baseline did not change these associations. Excluding those with a smoking history, obstructive lung disease, or cancer attenuated the associations of calf circumference (men) and body mass index (women).Conclusions.Based on the stronger association with mortality and given a more easy assessment in older persons, mid-upper arm circumference seems a more feasible and valid anthropometric measure of thinness than body mass index in older men and women. Β© 2010 The Author. Published by Oxford University Press on behalf of The Gerontological Society of America

    Is there a U-shaped association between physical activity and falling in older persons?

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    Summary: This study tests whether the relationship between physical activity and (recurrent) falling is U-shaped. Among 1,337 community-dwelling older persons, no evidence for a nonlinear association was found. If all older persons increase their physical activity level with 100 units, 4% may be prevented to become recurrent fallers. Introduction: Previous studies suggest a U-shaped relationship between physical activity and falling. This study tests this hypothesis and examines whether this relationship is modified by level of physical functioning. Methods: Community-dwelling persons (65+) from the Longitudinal Aging Study Amsterdam (LASA) were prospectively followed on falls for 3 years after baseline assessment in 1995/1996 (n=1,337). Outcome measures were time to first fall and time to recurrent falling. The LASA Physical Activity Questionnaire was used to calculate physical activity in minutes per day weighted for intensity (range 0-2000). Physical functioning was measured with physical performance tests and self reported functional limitations. Confounders were age, sex, body mass index, chronic diseases, psychotropic medication, cognitive functioning, depressive symptoms, and fear of falling. Results: No evidence for a nonlinear association was found (p for physical activity > 0.20). No significant association was found between physical activity and time to first fall. An increase in physical activity of 100 units led to a 4% decrease in risk of recurrent falling (adjusted hazard ratio 0.96, 95% confidence interval 0.92, 0.99). No interactions with physical performance or functional limitations were found (p>0.50). Conclusions: The hypothesized U-shaped relationship between physical activity and falling could not be confirmed. At higher levels of physical activity, the risk of recurrent falling decreased, while no association was found with fall risk

    Exploring cut-off values for large waist circumference in older adults: a new methodological approach

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    BACKGROUND: There is an ongoing debate about the applicability of current criteria for large waist circumference (WC) in older adults. OBJECTIVES: Our aim was to explore cut-off values for large WC in adults aged 70 years and older, using previously used and new methods. DESIGN: Prospective cohort study. PARTICIPANTS: Data of 1049 participants of the Longitudinal Aging Study Amsterdam (LASA) (1995-1996), aged 70-88y, were used. MEASUREMENTS: Measured BMI and WC, and self-reported mobility limitations. RESULTS: Linear regression analyses showed that the values of WC corresponding to BMI of 25kg/m2 and 30kg/m2 were higher than the current cut-offs. Cut-offs found in men were 97 and 110cm, whereas 88 and 98cm represented the cut-offs in women. Areas under the Receiver Operating Characteristic (ROC) curves showed that the accuracy to predict mobility limitations improved when the higher cut-offs were applied. Spline regression curves showed that the relationship of WC with mobility limitations was U-shaped in men, while in women, the risk for mobility limitations increased gradually with increasing WC. However, at the level of current cut-off values for WC the odds for mobility limitations were not increased. CONCLUSION: Based on results of extensive analyses, this study suggests that the cut-offs for large WC should be higher when applied to older adults. The association of WC with other negative health outcomes needs to be investigated to establish the final cut-points

    Self-reported diabetes is associated with self-management behaviour: a cohort study

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    <p>Abstract</p> <p>Background</p> <p>The purposes of this cohort study were to establish how frequently people with physician-diagnosed diabetes self-reported the disease, to determine factors associated with self-reporting of diabetes, and to evaluate subsequent differences in self-management behaviour, health care utilisation and clinical outcomes between people who do and do not report their disease.</p> <p>Methods</p> <p>We used a registry of physician-diagnosed diabetes as a reference standard. We studied respondents to a 2000/01 population-based health survey who were in the registry (n = 1,812), and we determined the proportion who reported having diabetes during the survey. Baseline factors associated with self-report and subsequent behavioural, utilisation and clinical differences between those who did and did not self-report were defined from the survey responses and from linkage with administrative data sources.</p> <p>Results</p> <p>Only 75% of people with physician-diagnosed diabetes reported having the disease. People who did self-report were more likely to be male, to live in rural areas, to have longer disease duration and to have received specialist physician care. People who did not report having diabetes in the survey were markedly less likely to perform capillary blood glucose monitoring in the subsequent two years (OR 0.05, 95% CI 0.02 to 0.08). They were also less likely to receive specialist physician care (OR 0.55, 95% CI 0.37 to 0.86), and were less likely to require hospital care for hypo- or hyperglycaemia (OR 0.09, 95% CI 0.01 to 0.28).</p> <p>Conclusion</p> <p>Many people with physician-diagnosed diabetes do not report having the disease, but most demographic and clinical features do not distinguish these individuals. These individuals are much less likely to perform capillary glucose monitoring, suggesting that their diabetes self-management is inadequate. Clinicians may be able to use the absence of glucose monitoring as a screening tool to identify people needing a detailed evaluation of their disease knowledge.</p

    Predictors for falls and fractures in the longitudinal aging study Amsterdam

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    The objective of this study was to identify easily measurable predictors for falls, recurrent falls, and fractures using a population-based prospective cohort study of 1469 elderly, born before 1931, in three regions of the Netherlands. The baseline at-home interview was in 1992. In 1995, falls experienced in the preceding year and fractures over the preceding 38- month period were registered. In a period of 1 year, 32% of the participants fell at least once, and 15% fell two or more times. The rate of recurrent falls was similar in men and women up until the age of 75 years. The total number of fractures was 85, including 23 wrist fractures, 12 hip fractures, and 9 humerus fractures. The incidence density per 1000 person-years for any fracture was 25.1 (95% confidence interval [CI], 18.9-31.4) for women and 8.2 (95% CI, 4.5-12.0) for men, respectively. Multiple logistic regression identified urinary incontinence, impaired mobility, use of analgetics, and use of antiepileptic drugs as the predictors most strongly associated with recurrent falls. Female gender, living alone, past fractures, inactivity, body height, and use of analgetics proved to be the predictors most strongly associated with fractures. The probabilities of recurrent falls were 4.7% (95% CI, 2.9-7.5%) to 59.2% (95% CI, 24.1-86.9%) with zero to four predictors, respectively. The probability of fractures ranged from 0.0% (95% CI, 0.0-0.4%) without any of the identified predictors to 12.9% (95% CI, 4.4- 32.2%) with all six predictors present. Our study shows that the risk of recurrent falls and of fractures can be predicted using up to, respectively, four and six easily measurable predictors. This study emphasizes the importance of impaired mobility and inactivity as predictors for falls and fractures
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