228 research outputs found

    Students' perceptions of errors in mathematics learning in Tanzanian secondary schools

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    Students' perceptions of errors in mathematics learning in Tanzanian secondary schools

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    Making intelligent cities in Europe climate-neutral: About the necessity to integrate technical and socio-cultural innovations

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    Smart urban futures are currently being tested and promoted in Europe using innovative and intelligent urban technologies at different spatial scales, in individual sectors such as energy or transport, or by using specific technological innovations. However, the great transformation, though often called for and widely advocated, is yet to come. This paper discusses the necessity of promoting integrative approaches that go beyond technology-centered solutions with the aim of opening up paths towards urban climate neutrality: Precisely because urban futures are hardly predictable due to diverse and partly still hidden influencing factors, it is important to include especially socio-cultural innovations, as well as resilient technical solutions. The considerations developed in this regard conclude with a presentation of the contributions in this TATuP special topic.Smarte urbane ZukĂŒnfte werden derzeit in Europa unter dem Einsatz innovativer und intelligenter urbaner Technologien auf unterschiedlichen rĂ€umlichen Skalierungsebenen, in einzelnen Sektoren wie Energie oder Verkehr bzw. anhand spezifischer technologischer Erneuerungen erprobt und vorangetrieben. Allerdings steht die vielfach beschworene große Transformation in den StĂ€dten noch aus. Dieser Beitrag diskutiert die Notwendigkeit, ĂŒber technikzentrierte Lösungen hinausgehende integrative AnsĂ€tze zu fördern, um Wege hin zur urbanen KlimaneutralitĂ€t zu eröffnen: Gerade weil urbane ZukĂŒnfte angesichts vielfĂ€ltiger und teils noch verborgener Einflussfaktoren kaum vorhersagbar sind, gilt es, neben resilienten technischen Lösungen, insbesondere soziokulturelle Innovationen einzubeziehen. Die hierzu entwickelten Überlegungen schließen mit einer Vorstellung der BeitrĂ€ge in diesem TATuP-Thema ab

    Climate-neutral and intelligent cities in Europe : Mission statements, paths, risks

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    The great transformation to climate-neutral cites in Europe, though often called for and widely advocated, is yet to come. This TATuP special topic underscores the necessity of integrative approaches that combine smart and intelligent urban technologies with socio-cultural innovations to open up paths towards urban climate neutrality. Edited by Cordula Kropp (ZIRIUS/University of Stuttgart), Astrid Ley (SI/University of Stuttgart), Sadeeb Simon Ottenburger (ITES/Karlsruhe Institute of Technology), Ulrich Ufer (ITAS/Karlsruhe Institute of Technology

    Energy/Environment Models: Relationship to Planning in Wisconsin, GDR, Rhone Alps

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    This report is a description and cross-regional comparison of the institutional structures and modeling methodologies of the three regions participating in the IIASA Research Program on Management of Regional Energy/Environment Systems. Descriptions are presented for the state of Wisconsin (USA), the German Democratic Republic, and the Rhone-Alpes Region (France), by specialists and policy makers from the respective regions. These descriptions demonstrate quite vividly the relationships between the institutional structure of a region and its use of models and planning tools

    The challenges of clinical trials in fragile X syndrome

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    RATIONALE: Advances in understanding the underlying mechanisms of conditions such as fragile X syndrome (FXS) and autism spectrum disorders have revealed heterogeneous populations. Recent trials of novel FXS therapies have highlighted several challenges including subpopulations with possibly differential therapeutic responses, the lack of specific outcome measures capturing the full range of improvements of patients with FXS, and a lack of biomarkers that can track whether a specific mechanism is responsive to a new drug and whether the response correlates with clinical improvement. OBJECTIVES: We review the phenotypic heterogeneity of FXS and the implications for clinical research in FXS and other neurodevelopmental disorders. RESULTS: Residual levels of fragile X mental retardation protein (FMRP) expression explain in part the heterogeneity in the FXS phenotype; studies indicate a correlation with both cognitive and behavioral deficits. However, this does not fully explain the extent of phenotypic variance observed or the variability of drug response. Post hoc analyses of studies involving the selective mGluR5 antagonist mavoglurant and the GABAB agonist arbaclofen have uncovered significant therapeutic responses following patient stratification according to FMR1 promoter methylation patterns or baseline severity of social withdrawal, respectively. Future studies designed to quantify disease modification will need to develop new strategies to track changes effectively over time and in multiple symptom domains. CONCLUSION: Appropriate selection of patients and outcome measures is central to optimizing future clinical investigations of these complex disorders

    Entwicklung von Strukturmodellen fĂŒr Hydroxy-Interkalierte Tonminerale zur quantitativen Rietveld-basierten Phasenanalyse von Böden

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    Chemische und physikalische Bodeneigenschaften werden entscheidend vom Tongehalt und der Zusammensetzung der Tonfraktion geprĂ€gt. Tonminerale pedogenen Ursprungs können dabei sehr komplex sein. Insbesondere unter sauren Bedingungen kann gelöstes Al in den Zwischenschichten quellfĂ€higer 2:1 Tonminerale (Smectit, Vermiculit) durch die Bildung nicht austauschbarer Al-Polymere gebunden werden. So kann eine Reihe sogenannter Hydroxy-Interkalierter Minerale (HIM) entstehen. GegenwĂ€rtig entziehen sich diese Phasen jedoch einer verlĂ€sslichen Quantifizierung mittels Röntgenbeugung und Rietveld-Analyse, da hierfĂŒr keine kristallografischen Strukturmodelle vorliegen. Ziel unseres Projektes ist daher die Entwicklung von Strukturmodellen fĂŒr die quantitative Beschreibung pedogener HIM-Phasen, welche folgende Schritte umfasst: (1) Identifizierung wichtiger natĂŒrlich vorkommender HIM in Böden unterschiedlichen Verwitterungsgrades, (2) Abtrennung/Herstellung phasenreiner Proben zur PrĂŒfung/Verbesserung des Strukturmodells, sowie (3) ÜberprĂŒfung des Strukturmodells an natĂŒrlichen Proben (Phasengemischen). Die Identifizierung typischer HIM wurde anhand einer 120.000 Jahre alten Bodenchronosequenz (Franz-Josef Gletscher, Neuseeland) vorgenommen. Hierbei konnten diverse intermediĂ€re Phasen wie z.B. Vermiculit, Chlorit und Chlorit-Hydroxy-Interkalierter Smectit identifiziert werden, weshalb Hydroxy-Interkalierter Smectit (HIS) als erstes zu erstellendes Strukturmodell ausgewĂ€hlt wurde. Da sich HIM generell im gleichen KorngrĂ¶ĂŸenbereich anderer Tonminerale befinden, bzw. mit diesen verwachsen sind, können sie nicht phasenrein abgetrennt werden, wie fĂŒr den zweiten Schritt der Modellentwicklung notwendig. Aus diesem Grund wurde im Labor eine Probenserie von 7 HIS aus natĂŒrlichem Smectit (Bentonit von Milos, Griechenland) mit unterschiedlichem Grad der Al-Belegung (0-100%) hergestellt. HierfĂŒr wurde zu 6 Teilproben 0,1 mol/L AlCl3 gegeben und mit 0,3 mol/L NaOH Lösung bis pH=5,5 titriert. Die Teilproben unterschieden sich anhand der Volumina 0,1 mol/L AlCl3 Lösung sowie den Reaktionszeiten. Eine siebte Teilprobe wurde nicht behandelt (0% Belegung). Alle Proben wurden mittels Multimethodeneinsatz charakterisiert. Der vorliegende Beitrag gibt einen Einblick in den Ablauf und die damit verbundenen Schwierigkeiten in der Entwicklung eines Strukturmodells fĂŒr HIM, welche eine quantitative Beschreibung von Hydroxy-Interkalierten Tonmineralen in Böden zukĂŒnftig ermöglichen soll

    Monoamine oxidase-A promotes protective autophagy in human SH-SY5Y neuroblastoma cells through Bcl-2 phosphorylation.

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    Monoamine oxidases (MAOs) are located on the outer mitochondrial membrane and are drug targets for the treatment of neurological disorders. MAOs control the levels of neurotransmitters in the brain via oxidative deamination and contribute to reactive oxygen species (ROS) generation through their catalytic by-product H2O2. Increased ROS levels may modulate mitochondrial function and mitochondrial dysfunction is implicated in a vast array of disorders. However, the downstream effects of MAO-A mediated ROS production in a neuronal model has not been previously investigated. In this study, using MAO-A overexpressing neuroblastoma cells, we demonstrate that higher levels of MAO-A protein/activity results in increased basal ROS levels with associated increase in protein oxidation. Increased MAO-A levels result in increased Lysine-63 linked ubiquitination of mitochondrial proteins and promotes autophagy through Bcl-2 phosphorylation. Furthermore, ROS generated locally on the mitochondrial outer membrane by MAO-A promotes phosphorylation of dynamin-1-like protein, leading to mitochondrial fragmentation and clearance without complete loss of mitochondrial membrane potential. Cellular ATP levels are maintained following MAO-A overexpression and complex IV activity/protein levels increased, revealing a close relationship between MAO-A levels and mitochondrial function. Finally, the downstream effects of increased MAO-A levels are dependent on the availability of amine substrates and in the presence of exogenous substrate, cell viability is dramatically reduced. This study shows for the first time that MAO-A generated ROS is involved in quality control signalling, and increase in MAO-A protein levels leads to a protective cellular response in order to mediate removal of damaged macromolecules/organelles, but substrate availability may ultimately determine cell fate. The latter is particularly important in conditions such as Parkinson's disease, where a dopamine precursor is used to treat disease symptoms and highlights that the fate of MAO-A containing dopaminergic neurons may depend on both MAO-A levels and catecholamine substrate availability
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