156 research outputs found

    Scientific reasoning skills predict topic-specific knowledge after participation in a citizen science project on urban wildlife ecology

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    In citizen science (CS) projects, citizens who are not professional scientists participate in scientific research. Besides serving research purposes, CS projects provide participants opportunities for inquiry-based learning to promote their topic-specific knowledge and scientific reasoning skills. Previous research suggests that participants need scientific reasoning skills to engage in scientific activities and to learn from inquiry in CS projects. Participants' scientific reasoning skills, therefore, might enhance the resulting topic-specific knowledge at the end of a CS project. On the other hand, scientific reasoning skills themselves are a learning outcome of CS projects. Hence, they might play a double role in CS projects: as a learning outcome and as a prerequisite for acquiring knowledge. In the informal education context of CS, it has not yet been investigated whether scientific reasoning skills predict topic-specific knowledge or vice versa. To address this question, the research presented here used a cross-lagged panel design in two longitudinal field studies of a CS project on urban wildlife ecology (N = 144 participants). The results indicated that participants' scientific reasoning skills positively influenced their topic-specific knowledge at the end of the project, but not vice versa. Extending previous research on individual learning outcomes of CS projects, the results showed that inquiry-based learning in CS projects depends on certain prerequisites, such as participants' proficiency in scientific reasoning. We discuss the implications for future research on inquiry-based learning in CS projects and for further training of CS participants in acquiring scientific reasoning skills

    Working from Home and Walking during and after COVID

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    We investigate the relationship between people who worked from home during the pandemic and how often they walked before, during, and after COVID. We find that people who worked from home during the pandemic had the largest increases in walking frequency compared to people who did not work from home and people who were unemployed. Similarly, people who work from home also expect to walk more after the pandemic subsides compared to others. After controlling for socio-economic, demographic, and transportation factors, we found that working from home and having a high income are associated with a higher propensity of walking during and after the pandemic

    No Evidence for Circulating Retina Specific Autoreactive T-cells in Latent Tuberculosis-associated Uveitis and Sarcoid Uveitis

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    Purpose: To detect circulating retina-specific autoreactive CD4+ T-cells and antiretinal antibodies (ARA) in latent tuberculosis (TB)-associated uveitis or sarcoid uveitis patients. Methods: The presence of crude retinal extract (RE) autoreactive CD4+ T-cells was determined by a highly sensitive flowcytometric-based technique examining co-expression of CD25 and CD134 (OX40) on RE stimulated PBMC. The presence of ARA in available matched serum samples was assessed by indirect immunofluorescence. Results: No autoreactive CD4+ T-cells against RE could be detected in either latent TB-associated uveitis or sarcoid uveitis patients, while ARA were detected in the serum of the majority (5/6) of latent TB-associated uveitis and all (3/3) sarcoid uveitis patients. Conclusion: Even with the use of this highly sensitive flowcytometric technique circulating retina-specific autoreactive CD4+ T-cells could not be detected. In contrast, ARA were detected in the majority of patients indicating an adaptive humoral immune response toward retinal antigens had occurred

    Prevalence of Positive QuantiFERON-TB Gold In-Tube Test in Uveitis and its Clinical Implications in a Country Nonendemic for Tuberculosis

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    Purpose: To report on the prevalence and clinical implications of positive QuantiFERON-Gold (QFT-G) test results in the diagnostic evaluation of a large cohort of consecutive patients with uveitis in the Netherlands. Design: Retrospective cross-sectional study. Methods: This study included 710 consecutive patients who all underwent evaluation for uveitis including QFT-G testing. The ocular features, comorbidity, and abnormalities in diagnostic imaging and laboratory tests were registered for QFT-G–positive patients with uveitis. Results: Of all patients, 13% (92/710) were positive for QFT-G. Previously treated tuberculosis (TB) was documented in 2 patients. Of all 92 QFT-G–positive patients, culture-proven active TB was observed in 1 case. The proportion of patients with uveitis of unknown etiology was higher in QFT-G–positive than in the QFT-G–negative patients (54/92, 59% vs 238/618, 39%; P = .0004). The uveitis features of QFT-G–positive patients were mainly nonspecific. Of all QFT-G–positive patients with uveitis, 17 patients had chest imaging changes suggesting either TB or sarcoidosis. Twenty-nine QFT-G–positive patients with otherwise unexplained uveitis completed antituberculous therapy (29/710; 4% of all included patients) with beneficial effect in most cases. Conclusion: The QFT-G tested positive in 13% of patients with uveitis in the Netherlands, whereas only sporadic patients had a documented previous or active TB infection. The proportion of patients with unexplained uveitis was higher in QFT-G–positive patients. Though the association between uveitis and a positive QFT-G test might be coincidental, the majority of treated QFT-G–positive patients with otherwise unexplained severe uveitis cause had a beneficial response to antituberculous therapy

    Cell size is a determinant of stem cell potential during aging

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    Stem cells are remarkably small. Whether small size is important for stem cell function is unknown. We find that hematopoietic stem cells (HSCs) enlarge under conditions known to decrease stem cell function. This decreased fitness of large HSCs is due to reduced proliferation and was accompanied by altered metabolism. Preventing HSC enlargement or reducing large HSCs in size averts the loss of stem cell potential under conditions causing stem cell exhaustion. Last, we show that murine and human HSCs enlarge during aging. Preventing this age-dependent enlargement improves HSC function. We conclude that small cell size is important for stem cell function in vivo and propose that stem cell enlargement contributes to their functional decline during aging.Peer reviewe
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