15 research outputs found

    RSVP-Based Tasks for Examining Working Memory Capacity

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    In diesem technischen Bericht werden drei Aufgaben zur PrĂŒfung bzw. zur Beanspruchung unterschiedlicher Facetten der ArbeitsgedĂ€chtniskapazitĂ€t beschrieben. Die Aufgaben beruhen zum Teil auf Material von Oberauer (1993) sowie Oberauer et al. (2000, 2003). Sie wurden in RSVP programmiert und sind auf Apple-Macintosh-Rechnern lauffĂ€hig. Die Aufgaben eignen sich zur computerunterstĂŒtzten Erfassung oder Beanspruchung der ArbeitsgedĂ€chtniskapazitĂ€t im Einzelversuch, teilweise auch im Gruppenversuch und werden hauptsĂ€chlich in Forschungskontexten benutzt. FĂŒr jede Aufgabe werden das Konzept, die DurchfĂŒhrung, Auswertungs- und Anwendungsmöglichkeiten sowie gegebenenfalls Vergleichsdaten geschildert

    RSVP-Based Tasks for Examining Working Memory Capacity

    No full text
    In diesem technischen Bericht werden drei Aufgaben zur PrĂŒfung bzw. zur Beanspruchung unterschiedlicher Facetten der ArbeitsgedĂ€chtniskapazitĂ€t beschrieben. Die Aufgaben beruhen zum Teil auf Material von Oberauer (1993) sowie Oberauer et al. (2000, 2003). Sie wurden in RSVP programmiert und sind auf Apple-Macintosh-Rechnern lauffĂ€hig. Die Aufgaben eignen sich zur computerunterstĂŒtzten Erfassung oder Beanspruchung der ArbeitsgedĂ€chtniskapazitĂ€t im Einzelversuch, teilweise auch im Gruppenversuch und werden hauptsĂ€chlich in Forschungskontexten benutzt. FĂŒr jede Aufgabe werden das Konzept, die DurchfĂŒhrung, Auswertungs- und Anwendungsmöglichkeiten sowie gegebenenfalls Vergleichsdaten geschildert

    CCR4+ Regulatory T Cells Accumulate in the Very Elderly and Correlate With Superior 8-Year Survival

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    CD4(+) regulatory T cells (Tregs) are a distinct population of T cells involved in maintaining peripheral tolerance to self-antigens. Several studies have shown increased frequency and number of Tregs in the elderly. Whether such an increase has any clinical relevance has not been addressed. Here, we have analyzed circulating Tregs in 114 donors between the ages of 18 and 89 years and assessed their implications for survival of the very elderly. In line with previously published data, we observed higher proportions of Tregs in the elderly. Expression of chemokine receptor 4 (CCR4) by Tregs has been shown to characterize antigen-primed activated Tregs with immediate suppressive function. Thus we further analyzed Tregs expressing or lacking this chemokine receptor. There were more CCR4(+) and CCR4(-) Tregs in the elderly than the young. Finally, using a subset of 48 elderly donors participating in the Leiden 85-plus study we documented that people with greater median frequencies of CCR4(+) Tregs enjoyed a better 8-year survival rate than those with lower frequencies of these cells. Our data, demonstrating for the first time a positive correlation between increased frequency of Tregs and survival in the elderly, imply an increasing importance of controlling inappropriate immune responses and inflammation as we grew old

    CCR4 +

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    CD4(+) regulatory T cells (Tregs) are a distinct population of T cells involved in maintaining peripheral tolerance to self-antigens. Several studies have shown increased frequency and number of Tregs in the elderly. Whether such an increase has any clinical relevance has not been addressed. Here, we have analyzed circulating Tregs in 114 donors between the ages of 18 and 89 years and assessed their implications for survival of the very elderly. In line with previously published data, we observed higher proportions of Tregs in the elderly. Expression of chemokine receptor 4 (CCR4) by Tregs has been shown to characterize antigen-primed activated Tregs with immediate suppressive function. Thus we further analyzed Tregs expressing or lacking this chemokine receptor. There were more CCR4(+) and CCR4(-) Tregs in the elderly than the young. Finally, using a subset of 48 elderly donors participating in the Leiden 85-plus study we documented that people with greater median frequencies of CCR4(+) Tregs enjoyed a better 8-year survival rate than those with lower frequencies of these cells. Our data, demonstrating for the first time a positive correlation between increased frequency of Tregs and survival in the elderly, imply an increasing importance of controlling inappropriate immune responses and inflammation as we grew old

    Hallmark Features of Immunosenescence Are Absent in Familial Longevity

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    Seropositivity for CMV is one of the parameters of the "immune risk profile" associated with mortality in longitudinal studies of the very elderly and may accelerate immunosenescence. Thus, any genetic factors influencing human longevity may be associated with susceptibility to CMV and CMV-accelerated immunosenescence. To test this, we analyzed long-lived families in the Leiden Longevity Study (LLS) in which offspring enjoy a 30% reduced standardized mortality rate, possibly owing to genetic enrichment. Serum C-reactive protein levels and the frequency of different T cell subsets were compared between 97 LLS offspring and 97 controls (their partners, representing the normal population). We also determined the capacity of T cells to respond against immunodominant Ags from CMV in a smaller group of LLS subjects and controls. CMV infection was strongly associated with an age-related reduction in the frequency of naive T cells and an accumulation of CD45RA-re-expressing and late-differentiated effector memory T cells in the general population, but not in members of long-lived families. The latter also had significantly lower C-reactive protein levels, indicating a lower proinflammatory status compared with CMV-infected controls. Finally, T cells from a higher proportion of offspring mounted a proliferative response against CMV Ags, which was also of greater magnitude and broader specificity than controls. Our data suggest that these rare individuals genetically enriched for longevity are less susceptible to the characteristic CMV-associated age-driven immune alterations commonly considered to be hallmarks of immunosenescence, which might reflect better immunological control of the virus and contribute to their decreased mortality rate

    Infection with cytomegalovirus but not herpes simplex virus induces the accumulation of latedifferentiated CD4 <sub>+</sub> and CD8 <sub>+</sub> T-cells in humans

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    Human cytomegalovirus (CMV) establishes persistent, usually asymptomatic, infection in healthy people. Because CMV infection is associated with the presence of lower proportions of peripheral naĂŻve CD8 + T-cells and a higher fraction of late-differentiated CD8 + cells, commonly taken as biomarkers of age-associated compromised adaptive immunity ('immunosenescence'), we asked whether chronic exposure to any persistent virus mediates these effects. Herpes simplex virus (HSV) is also a widespread herpesvirus that establishes lifelong persistence, but, unlike CMV, its impact on the distribution of T-cell subsets has not been established. Here, we analysed T-cell subsets in 93 healthy people aged 42-81 years infected or not infected with CMV and/or HSV. Individuals harbouring CMV were confirmed to possess lower frequencies of nai{dotless}̈ve CD8 + T-cells (defined as CD45RA +CCR7 +CD27 +CD28 +) and greater proportions of late-differentiated effector memory (CD45RA-CCR7-CD27-CD28-) and so-called TEMRA (CD45RA +CCR7 -CD27 -CD28 -) CD4 and CD8 subsets, independent of HSV seropositivity. In CMV -seronegative donors, HSV did not affect T-cell subset distribution significantly. We conclude that these hallmarks of age-associated alterations to immune signatures are indeed observed in the general population in people infected with CMV and not those infected with a different persistent herpesvirus

    Using temporal information to construct, update, and retrieve situation models of narratives

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    Item does not contain fulltextFour experiments explored how readers use temporal information to construct and update situation models and retrieve them from memory. In Experiment 1, readers spontaneously constructed temporal and spatial situation models of single sentences. In Experiment 2, temporal inconsistencies caused problems in updating situation models similar to those observed previously for other dimensions of situation models. In Experiment 3, merely implied temporal order information was inferred from narratives, affecting comprehension of later sentences like explicitly stated order information. Moreover, inconsistent temporal order information prevented the creation and storage in memory of an integrated situation model. In Experiment 4, a temporal inconsistency increased processing time even if readers were unable to report the inconsistency. These results confirm the significance of the temporal dimension of situation models.14 p
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