58 research outputs found

    Agrammatic but numerate

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    A central question in cognitive neuroscience concerns the extent to which language enables other higher cognitive functions. In the case of mathematics, the resources of the language faculty, both lexical and syntactic, have been claimed to be important for exact calculation, and some functional brain imaging studies have shown that calculation is associated with activation of a network of left-hemisphere language regions, such as the angular gyrus and the banks of the intraparietal sulcus. We investigate the integrity of mathematical calculations in three men with large left-hemisphere perisylvian lesions. Despite severe grammatical impairment and some difficulty in processing phonological and orthographic number words, all basic computational procedures were intact across patients. All three patients solved mathematical problems involving recursiveness and structure-dependent operations (for example, in generating solutions to bracket equations). To our knowledge, these results demonstrate for the first time the remarkable independence of mathematical calculations from language grammar in the mature cognitive system

    Neuropsychological and neuroimaging characteristics of classical superficial siderosis

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    OBJECTIVE: To define the neuropsychological and neuroimaging characteristics of classical infratentorial superficial siderosis (iSS), a rare but disabling disorder defined by hemosiderin deposition affecting the superficial layers of the cerebellum, brainstem and spinal cord, usually associated with a slowly progressive neurological syndrome of deafness, ataxia and myelopathy. METHODS: We present the detailed neuropsychological and neuroimaging findings in 16 patients with iSS (mean age 57 years; 6 female). RESULTS: Cognitive impairment was present in 8/16 (50%) of patients: executive dysfunction was the most prevalent (44%), followed by impairment of visual recognition memory (27%); other cognitive domains were largely spared. Disease symptom duration was significantly correlated with the number of cognitive domains impaired (r = 0.59, p = 0.011). Mood disorders were also common (anxiety 62%, depression 38%, both 69%) but not associated with disease symptom duration. MRI findings revealed siderosis was not only in infratentorial brain regions, but also in characteristic widespread symmetrical supratentorial brain regions, independent of disease duration and degree of cognitive impairment. The presence of small vessel disease markers was very low and did not account for the cognitive impairment observed. CONCLUSION: Neuropsychological disturbances are common in iSS and need to be routinely investigated. The lack of association between the anatomical extent of hemosiderin and cognitive impairment or disease duration suggests that hemosiderin itself is not directly neurotoxic. Additional biomarkers of iSS disease severity and progression are needed for future research and clinical trials

    The environmental citizenship opinions questionnaire: a self-assessment tool for secondary students

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    IntroductionWe present a validated instrument for assessing Environmental Citizenship (EC) of students in lower secondary education. The Environmental Citizenship Opinions (ECO) questionnaire focusses on general citizenship components, key sustainability competences, and Socio-Scientific Reasoning aspects. By combining these domains, our work provides a needed innovation as these different aspects of EC have not previously been covered in one single, balanced and validated measurement instrument.MethodsThe ECO questionnaire was validated through a pilot round and a subsequent large-scale study (781 lower secondary students). Several rounds of Confirmatory Factor Analysis resulted in a final model of 38 items divided in 7 first order and 5 s order constructs.ResultsThe final model fit statistics indicate near excellent quality of our model (RMSEA = 0.036, CFI = 0.93, TLI = 0.93, SRMR = 0.05), which consists of EC knowledge, EC attitudes, EC skills, EC reflection and complexity of EC issues. Calculations on the relative attribution of each of the five main constructs to overall environmental sustainability citizenship, highlight that attitudes and reflection skills are the most important constituents.DiscussionOur result present the ECO questionnaire as a valuable, valid and reliable tool to measure environmental citizenship of students. Applications in practice include monitoring student’s development and supporting teachers during the challenging task of effective teaching for EC in and outside the classroom

    Science and society in education

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    This booklet is for teachers who want to expand their teaching approaches to include socio-scientific issues which enrich and give meaning to core scientific principles. It is meant to enhance young people’s curiosity about the social and scientific world and raise important questions about issues which affect their lives. We call this approach Socio-Scientific Inquiry-Based Learning, or ‘SSIBL’ for short. Chapters 1 and 2 present an introduction to the theoretical background of SSIBL. In chapter 3, SSIBL will be approached from a classroom perspective, providing a simplified version of the framework and showing teaching examples

    High cellular monocyte activation in people living with human immunodeficiency virus on combination antiretroviral therapy and lifestyle-matched controls is associated with greater inflammation in cerebrospinal fluid

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    Background. Increased monocyte activation and intestinal damage have been shown to be predictive for the increased morbidity and mortality observed in treated people living with human immunodeficiency virus (PLHIV). Methods. A cross-sectional analysis of cellular and soluble markers of monocyte activation, coagulation, intestinal damage, and inflammation in plasma and cerebrospinal fluid (CSF) of PLHIV with suppressed plasma viremia on combination antiretroviral therapy and age and demographically comparable HIV-negative individuals participating in the Comorbidity in Relation to AIDS (COBRA) cohort and, where appropriate, age-matched blood bank donors (BBD). Results. People living with HIV, HIV-negative individuals, and BBD had comparable percentages of classical, intermediate, and nonclassical monocytes. Expression of CD163, CD32, CD64, HLA-DR, CD38, CD40, CD86, CD91, CD11c, and CX3CR1 on monocytes did not differ between PLHIV and HIV-negative individuals, but it differed significantly from BBD. Principal component analysis revealed that 57.5% of PLHIV and 62.5% of HIV-negative individuals had a high monocyte activation profile compared with 2.9% of BBD. Cellular monocyte activation in the COBRA cohort was strongly associated with soluble markers of monocyte activation and inflammation in the CSF. Conclusions. People living with HIV and HIV-negative COBRA participants had high levels of cellular monocyte activation compared with age-matched BBD. High monocyte activation was predictive for inflammation in the CSF

    Cognitive function and drivers of cognitive impairment in a European and a Korean cohort of people living with HIV

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    Although cognitive impairments are still prevalent in the current antiretroviral therapy era, limited investigations have compared the prevalence of cognitive disorder in people living with HIV (PLWH) and its determinants in different regions and ethnicities. We compared cognitive performance across six domains using comparable batteries in 134 PLWH aged ≥45 years from the COBRA study (Netherlands, UK), and 194 PLWH aged ≥18 years from the NeuroAIDS Project (South Korea). Cognitive scores were standardized and averaged to obtain domain and global T-scores. Associations with global T-scores were evaluated using multivariable regression and the ability of individual tests to detect cognitive impairment (global T-score ≤45) was assessed using the area-under-the-receiver-operating-characteristic curve (AUROC). The median (interquartile range) age of participants was 56 (51, 62) years in COBRA (88% white ethnicity, 93% male) and 45 (37, 52) years in NeuroAIDS (100% Korean ethnicity, 94% male). The rate of cognitive impairment was 18.8% and 18.0%, respectively (p = 0.86). In COBRA, Black-African ethnicity was the factor most strongly associated with cognitive function (11.1 [7.7, 14.5] lower scores vs. white ethnicity, p < 0.01), whereas in NeuroAIDS, age (0.6 [0.1, 1.3] per 10-year, p<0.01) and education (0.7 [0.5, 0.9] per year, p<0.01) were significantly associated with cognitive function with anemia showing only a weak association (−1.2 [−2.6, 0.3], p=0.12). Cognitive domains most associated with cognitive impairment were attention (AUROC = 0.86) and executive function (AUROC = 0.87) in COBRA and processing speed (AUROC = 0.80), motor function (AUROC = 0.78) and language (AUROC = 0.78) in NeuroAIDS. Two cohorts of PLWH from different geographical regions report similar rates of cognitive impairment but different risk factors and cognitive profiles of impairment

    Validation of a Novel Multivariate Method of Defining HIV-Associated Cognitive Impairment

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    Background. The optimum method of defining cognitive impairment in virally suppressed people living with HIV is unknown. We evaluated the relationships between cognitive impairment, including using a novel multivariate method (NMM), patientreported outcome measures (PROMs), and neuroimaging markers of brain structure across 3 cohorts.Methods. Differences in the prevalence of cognitive impairment, PROMs, and neuroimaging data from the COBRA, CHARTER, and POPPY cohorts (total n = 908) were determined between HIV-positive participants with and without cognitive impairment defined using the HIV-associated neurocognitive disorders (HAND), global deficit score (GDS), and NMM criteria.Results. The prevalence of cognitive impairment varied by up to 27% between methods used to define impairment (eg, 48% for HAND vs 21% for NMM in the CHARTER study). Associations between objective cognitive impairment and subjective cognitive complaints generally were weak. Physical and mental health summary scores (SF-36) were lowest for NMM-defined impairment (P&lt;.05). There were no differences in brain volumes or cortical thickness between participants with and without cognitive impairment defined using the HAND and GDS measures. In contrast, those identified with cognitive impairment by the NMM had reduced mean cortical thickness in both hemispheres (P&lt;.05), as well as smaller brain volumes (P&lt;.01). The associations with measures of white matter microstructure and brain-predicted age generally were weaker.Conclusion. Different methods of defining cognitive impairment identify different people with varying symptomatology and measures of brain injury. Overall, NMM-defined impairment was associated with most neuroimaging abnormalities and poorer selfreported health status. This may be due to the statistical advantage of using a multivariate approach

    Do people living with HIV experience greater age advancement than their HIV-negative counterparts?

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    Objectives: Despite successful antiretroviral therapy, people living with HIV (PLWH) may show signs of premature/accentuated aging. We compared established biomarkers of aging in PLWH, appropriately chosen HIV-negative individuals, and blood donors, and explored factors associated with biological age advancement. Design: Cross-sectional analysis of 134 PLWH on suppressive antiretroviral therapy, 79 lifestyle-comparable HIV-negative controls aged 45 years or older from the Co-mor- Bidity in Relation to AIDS (COBRA) cohort, and 35 age-matched blood donors. Methods: Biological age was estimated using a validated algorithm based on 10 biomarkers. Associations between ‘age advancement’ (biological minus chronological age) and HIV status/parameters, lifestyle, cytomegalovirus (CMV), hepatitis B (HBV) and hepatitis C virus (HCV) infections were investigated using linear regression. Results: The average (95% CI) age advancement was greater in both HIV-positive [13.2 (11.6–14.9) years] and HIV-negative [5.5 (3.8–7.2) years] COBRA participants compared with blood donors [7.0 (4.1 to 9.9) years, both P’s<0.001)], but also in HIV-positive compared with HIV-negative participants (P<0.001). Chronic HBV, higher anti-CMV IgG titer and CD8þ T-cell count were each associated with increased age advancement, independently of HIV-status/group. Among HIV-positive participants, age advancement was increased by 3.5 (0.1–6.8) years among those with nadir CD4þ T-cell count less than 200 cells/ml and by 0.1 (0.06–0.2) years for each additional month of exposure to saquinavir
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