69 research outputs found

    Investigation of Finnish and German 9th grade students’ personal meaning with relation to mathematics

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    This study focuses on a comparison of personal meanings that students from Finland (FIN) and Germany (GER) assign to (learning) mathematics. Participants are 256 Finnish and 276 German ninth graders. The survey consists of 18 scales that are based on the theory of personal meaning. The original German version was translated into Finnish. Using item response theory (IRT) partial credit models, the psychometric properties of the scales were found to be good. As statistical procedure, Differential Item Functioning (DIF) analysis and mean comparisons were conducted to compare the two groups’ (FIN and GER) responses. Indicators of educational system and curriculum could be found in students’ responses to explain similarities and differences between the two samples. In both countries, social inclusion is meaningful for most of the students (Support by teacher, Experience of relatedness, and Emotional-affective relation to teacher). In addition, it is personally meaningful for Finnish students to do well in mathematics. This shows a link to identity-related questions such as confirming important aspects of the self. Hence, personal meanings related to mathematics are more common in Finland than in Germany (Active practice of mathematics, Cognitive challenge, and Self-perfection). Neruja Suriakumaran1, Markku S. Hannula2 and Maike Vollstedt1This study focuses on a comparison of personal meanings that students from Finland (FIN) and Germany (GER) assign to (learning) mathematics. Participants are 256 Finnish and 276 German ninth graders. The survey consists of 18 scales that are based on the theory of personal meaning. The original German version was translated into Finnish. Using item response theory (IRT) partial credit models, the psychometric properties of the scales were found to be good. As statistical procedure, Differential Item Functioning (DIF) analysis and mean comparisons were conducted to compare the two groups’ (FIN and GER) responses. Indicators of educational system and curriculum could be found in students’ responses to explain similarities and differences between the two samples. In both countries, social inclusion is meaningful for most of the students (Support by teacher, Experience of relatedness, and Emotional-affective relation to teacher). In addition, it is personally meaningful for Finnish students to do well in mathematics. This shows a link to identity-related questions such as confirming important aspects of the self. Hence, personal meanings related to mathematics are more common in Finland than in Germany (Active practice of mathematics, Cognitive challenge, and Self-perfection).Peer reviewe

    Fresh Perspectives on Motivation, Engagement, and Identity : An Introduction

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    The 13th International Congress on Mathematical Education [ICME-13] was organized in Hamburg, Germany in 2016. This chapter is the introduction to the book composed of the selected papers presented in the Topic Study Group 28 on “Affect, beliefs and identity in mathematics education”. After the conference, 33 reworked papers had been submitted for evaluation and, based on a peer-reviewing process, 15 chapters were judged to be suitable for inclusion in the book. These contributions were clustered as follows: a stand-alone overview chapter, followed by three sections under the headings of interest, motivation, and values; engagement and flow; and identity. To enrich and broaden the contents of the book even further, the book editors invited three established mathematics educators to each write a commentary and critique on one of the three clusters. Mathematics-related affect is a research area with a variety of theoretical approaches. The different sections of the book provide a rich and diverse spectrum of different approaches, exhibiting both chapters that build on extensive research in the field as well as interesting new openings to the directions less explored in mathematics education to this date. The commentary chapters and the final conclusion offer insightful reflections on this field of research.Peer reviewe

    Comparison of target enrichment strategies for ancient pathogen DNA

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    In ancient DNA research, the degraded nature of the samples generally results in poor yields of highly fragmented DNA; targeted DNA enrichment is thus required to maximize research outcomes. The three commonly used methods ? array-based hybridization capture and in-solution capture using either RNA or DNA baits ? have different characteristics that may influence the capture efficiency, specificity and reproducibility. Here we compare their performance in enriching pathogen DNA of Mycobacterium leprae and Treponema pallidum from 11 ancient and 19 modern samples. We find that in-solution approaches are the most effective method in ancient and modern samples of both pathogens and that RNA baits usually perform better than DNA baits

    Functional Characterization of Rare RAB12 Variants and Their Role in Musician's and Other Dystonias

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    Mutations in RAB (member of the Ras superfamily) genes are increasingly recognized as cause of a variety of disorders including neurological conditions. While musician's dystonia (MD) and writer's dystonia (WD) are task-specific movement disorders, other dystonias persistently affect postures as in cervical dystonia. Little is known about the underlying etiology. Next-generation sequencing revealed a rare missense variant (c.586A> G; p.Ile196Val) in RAB12 in two of three MD/WD families. Next, we tested 916 additional dystonia patients; 512 Parkinson's disease patients; and 461 healthy controls for RAB12 variants and identified 10 additional carriers of rare missense changes among dystonia patients (1.1%) but only one carrier in non-dystonic individuals (0.1%; p = 0.005). The detected variants among index patients comprised p.Ile196Val (n = 6); p.Ala174Thr (n = 3); p.Gly13Asp; p.Ala148Thr; and p.Arg181Gln in patients with MD; cervical dystonia; or WD. Two relatives of MD patients with WD also carried p.Ile196Val. The two variants identified in MD patients (p.Ile196Val; p.Gly13Asp) were characterized on endogenous levels in patient-derived fibroblasts and in two RAB12-overexpressing cell models. The ability to hydrolyze guanosine triphosphate (GTP), so called GTPase activity, was increased in mutants compared to wildtype. Furthermore, subcellular distribution of RAB12 in mutants was altered in fibroblasts. Soluble Transferrin receptor 1 levels were reduced in the blood of all three tested p.Ile196Val carriers. In conclusion, we demonstrate an enrichment of missense changes among dystonia patients. Functional characterization revealed altered enzyme activity and lysosomal distribution in mutants suggesting a contribution of RAB12 variants to MD and other dystonias

    Bioluminescent Imaging Reveals Divergent Viral Pathogenesis in Two Strains of Stat1-Deficient Mice, and in αßγ Interferon Receptor-Deficient Mice

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    Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1−/− and IFNαßγR−/− mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1−/− mice and in IFNαßγR−/− mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1−/− (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFNαßγR−/− mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1−/− and IFNαßγR−/− mice, we infected an additional Stat1−/− strain deleted in the DNA-binding domain (129Stat1−/− (DBD)). These 129Stat1−/− (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFNαßγR−/− mice. This lethal pattern was also observed when 129Stat1−/− (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1−/− (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1−/− mouse strains. The data are consistent with the hypothesis that Stat1−/− (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection

    Embracing Monogenic Parkinson's Disease: The MJFF Global Genetic PD Cohort

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    Background: As gene-targeted therapies are increasingly being developed for Parkinson's disease (PD), identifying and characterizing carriers of specific genetic pathogenic variants is imperative. Only a small fraction of the estimated number of subjects with monogenic PD worldwide are currently represented in the literature and availability of clinical data and clinical trial-ready cohorts is limited. Objective: The objectives are to (1) establish an international cohort of affected and unaffected individuals with PD-linked variants; (2) provide harmonized and quality-controlled clinical characterization data for each included individual; and (3) further promote collaboration of researchers in the field of monogenic PD. Methods: We conducted a worldwide, systematic online survey to collect individual-level data on individuals with PD-linked variants in SNCA, LRRK2, VPS35, PRKN, PINK1, DJ-1, as well as selected pathogenic and risk variants in GBA and corresponding demographic, clinical, and genetic data. All registered cases underwent thorough quality checks, and pathogenicity scoring of the variants and genotype–phenotype relationships were analyzed. Results: We collected 3888 variant carriers for our analyses, reported by 92 centers (42 countries) worldwide. Of the included individuals, 3185 had a diagnosis of PD (ie, 1306 LRRK2, 115 SNCA, 23 VPS35, 429 PRKN, 75 PINK1, 13 DJ-1, and 1224 GBA) and 703 were unaffected (ie, 328 LRRK2, 32 SNCA, 3 VPS35, 1 PRKN, 1 PINK1, and 338 GBA). In total, we identified 269 different pathogenic variants; 1322 individuals in our cohort (34%) were indicated as not previously published. Conclusions: Within the MJFF Global Genetic PD Study Group, we (1) established the largest international cohort of affected and unaffected individuals carrying PD-linked variants; (2) provide harmonized and quality-controlled clinical and genetic data for each included individual; (3) promote collaboration in the field of genetic PD with a view toward clinical and genetic stratification of patients for gene-targeted clinical trials. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

    Using global team science to identify genetic parkinson's disease worldwide.

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    Defining the causes of sporadic Parkinson’s disease in the global Parkinson’s genetics program (GP2)

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    \ua9 2023, Springer Nature Limited. The Global Parkinson’s Genetics Program (GP2) will genotype over 150,000 participants from around the world, and integrate genetic and clinical data for use in large-scale analyses to dramatically expand our understanding of the genetic architecture of PD. This report details the workflow for cohort integration into the complex arm of GP2, and together with our outline of the monogenic hub in a companion paper, provides a generalizable blueprint for establishing large scale collaborative research consortia

    Multi-ancestry genome-wide association meta-analysis of Parkinson’s disease

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    \ua9 2023, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply. Although over 90 independent risk variants have been identified for Parkinson’s disease using genome-wide association studies, most studies have been performed in just one population at a time. Here we performed a large-scale multi-ancestry meta-analysis of Parkinson’s disease with 49,049 cases, 18,785 proxy cases and 2,458,063 controls including individuals of European, East Asian, Latin American and African ancestry. In a meta-analysis, we identified 78 independent genome-wide significant loci, including 12 potentially novel loci (MTF2, PIK3CA, ADD1, SYBU, IRS2, USP8, PIGL, FASN, MYLK2, USP25, EP300 and PPP6R2) and fine-mapped 6 putative causal variants at 6 known PD loci. By combining our results with publicly available eQTL data, we identified 25 putative risk genes in these novel loci whose expression is associated with PD risk. This work lays the groundwork for future efforts aimed at identifying PD loci in non-European populations
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