124 research outputs found

    In vitro analyses of mitochondrial ATP/phosphate carriers from Arabidopsis thaliana revealed unexpected Ca2+-effects

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    Background: Adenine nucleotide/phosphate carriers (APCs) from mammals and yeast are commonly known to adapt the mitochondrial adenine nucleotide pool in accordance to cellular demands. They catalyze adenine nucleotide - particularly ATP-Mg - and phosphate exchange and their activity is regulated by calcium. Our current knowledge about corresponding proteins from plants is comparably limited. Recently, the three putative APCs from Arabidopsis thaliana were shown to restore the specific growth phenotype of APC yeast loss-of-function mutants and to interact with calcium via their N-terminal EF-hand motifs in vitro. In this study, we performed biochemical characterization of all three APC isoforms from A. thaliana to gain further insights into their functional properties. Results: Recombinant plant APCs were functionally reconstituted into liposomes and their biochemical characteristics were determined by transport measurements using radiolabeled substrates. All three plant APCs were capable of ATP, ADP and phosphate exchange, however, high preference for ATP-Mg, as shown for orthologous carriers, was not detectable. By contrast, the obtained data suggest that in the liposomal system the plant APCs rather favor ATP-Ca as substrate. Moreover, investigation of a representative mutant APC protein revealed that the observed calcium effects on ATP transport did not primarily/essentially involve Ca2+-binding to the EF-hand motifs in the N-terminal domain of the carrier. Conclusion: Biochemical characteristics suggest that plant APCs can mediate net transport of adenine nucleotides and hence, like their pendants from animals and yeast, might be involved in the alteration of the mitochondrial adenine nucleotide pool. Although, ATP-Ca was identified as an apparent import substrate of plant APCs in vitro it is arguable whether ATP-Ca formation and thus the corresponding transport can take place in vivo

    Maxillary premolars extraction or molar distalization with or without TADs: cephalometric evaluation of soft tissue changes in Class II treatment

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    Introduction: Problem solving in Class II malocclusion treatment performed with premolars extractions or distalizing techniques in relation to the profile modification. Aim: To cephalometrically compare soft tissue changes produced either by maxillary premolar extraction, tooth-borne Pendulum appliance or bone-borne MGBM appliance. Materials and Methods: Both pre- (T1) and post-treatment (T2) lateral cephalograms of 89 skeletal Class II patients (36 M, 53 F), treated during pubertal growth spurt, were retrospectively selected. Three groups were formed based on the therapy performed: 30 patients had been treated with maxillary first premolars extraction (U4), 31 patients with a conventional tooth-borne distalizing with Pendulum appliance (PA), and 28 patients with a skeletally anchored distalizing appliance (MGBM). Soft tissue was analyzed comparing upper (UL) and lower (LL) lip’s points with regard to True Vertical Line (TVL) and Esthetic plane (E-plane). Skeletal and dental values have been recorded in order to cephalometrically compare ΔT2-T1 changes among groups and to correlate dental and skeletal changes to profile modifications. One-way ANOVA was employed to compare groups at T1. Paired sample t-tests were employed to assess significant intra- and intergroup differences between T2 and T1. Significance level was set at 0.05 Results: UL and LL showed a slight but not significant retrusion relative to TVL in all three groups. UL and LL distances to E-plane were not statistically significant among U4, PA, and MGBM groups. Independently of the treatment, UL was tangent to TVL in all groups. No statistically significant differences have been shown in skeletal records. Significant differences were recorded in Overjet among U4 than PA and MGBM groups. Conclusions: Class II malocclusion treatment with maxillary first premolar extraction, conventional or skeletal distalization did not significantly affect the profile producing similar changes in the soft tissue

    Dynamic culture of human liver equivalents inside a micro-bioreactor for long-term substance testing : From 23rd European Society for Animal Cell Technology (ESACT) Meeting: Better Cells for Better Health Lille, France. 23-26 June 2013

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    Published by BioMed Central: Materne, Eva-Maria et al.: Dynamic culture of human liver equivalents inside a micro-bioreactor for longterm substance testing. - In: BMC Proceedings. - ISSN 1753-6561 (online). - 7 (2012), suppl. 6, art. P72. - doi:10.1186/1753-6561-7-S6-P72

    Improving attitudes and knowledge in a citizen science project about urban bat ecology

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    In order to deal with the current, dramatic decline in biodiversity, the public at large needs to be aware of and participate in biodiversity research activities. One way to do this is citizen science projects, in which researchers collaborate with volunteering citizens in scientific research. However, it remains unclear whether engaging in such projects has an impact on the learning outcomes of volunteers. Previous research has so far presented mixed results on the improvement of citizens’ attitudes and knowledge, mostly because such research has focused only on single aspects of citizen science projects in case studies. To address these limitations, we investigated the impact of an urban bat ecology project on citizens’ attitudes and knowledge about bats, and on their engagement with citizen science. We also examined whether the degree of citizen participation (i.e., collecting data vs. collecting and analyzing data) had an influence on the outcomes. We conducted four field studies and used a survey-based, experimental, pre-/post-measurement design. To vary the degree of participation, we assessed the post measurement in one group directly after data collection, whereas, in a second group, we assessed it after data collection and analysis, at the end of the project. Across all studies, the results demonstrated that citizens’ content knowledge of urban bat ecology increased, and their attitudes toward bats and toward their engagement in citizen science improved during their participation. Citizens’ degrees of participation did not influence these outcomes. Thus, our research illustrates that citizen science can increase awareness of urban bat conservation, independently of citizens’ degree of participation. We discuss the implications of our findings for the citizen science community. © 2022 by the author(s)

    InterdisziplinĂ€re Studienprojekte gestalten: Aus der Praxis fĂŒr die Praxis

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    In dem Praxisband werden Konzepte und praktische Umsetzung von fachbereichsĂŒbergreifenden Studienprojekten dokumentiert. Grundlage ist das Know-how aus ĂŒber 30 interdisziplinĂ€ren Projekten fĂŒr 10 000 Studierende an der Technischen UniversitĂ€t Darmstadt. Die Publikation wendet sich an Lehrende, Hochschuldidaktiker sowie Lehr- und Studiengangentwickler. Das Autorenteam fĂŒhrt in das didaktische Konzept ein und erlĂ€utert die Gestaltung interdisziplinĂ€rer Wochen-, Semester- und Kleingruppenprojekte. Schwerpunkte der weiteren Kapitel sind die Qualifizierung von Studienprojekt-Tutoren sowie der strukturelle Rahmen fĂŒr die flĂ€chendeckende EinfĂŒhrung von interdisziplinĂ€ren Studienprojekten. Zahlreiche Übersichten, Checklisten, Beispiele und Vorlagen erleichtern die Umsetzung in die Praxis.The practical handbook documents concepts and practical implementation of interdepartmental study projects. It is based on know-how from more than 30 interdisciplinary projects for 10,000 students at Technische UniversitĂ€t Darmstadt. The publication is intended for teaching staff, university educationalists, as well as course developers. The team of authors gives an introduction to the didactic concept and explains the design of interdisciplinary weekly and semesterly projects and projects in small groups. Other chapters focus on qualification of study project tutors, as well as structural frameworks for comprehensive introduction of interdisciplinary study projects. Practical implementation is facilitated by numerous overviews, checklists, examples and models

    Erinnerte Macht. Antike HerrschergrÀber in transkultureller Perspektive

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    Zu den Leitformen der alten Reiche Ostasiens und der westlichen Antike gehören exponierte GrĂ€ber der fĂŒhrenden Persönlichkeiten. Die BeitrĂ€ge untersuchen, wie die Grabanlagen die Erinnerung an den Toten formten, zugleich die Wertvorstellungen ihrer Zeit spiegeln und zur Stabilisierung der geltenden Ordnung beitrugen. Dabei interessiert die Funktion der GrĂ€ber als Mittel der Selbstdarstellung und als Selbstbeschreibung des Herrschers. Aufschluss geben vor allem jene Monumente, die vom Regenten selber zu Lebzeiten geplant und errichtet worden sind. Ein zweiter Aspekt ist die Bedeutung des Grabs als Manifestation von Vorstellungen ĂŒber Herrschaft. So kann die Wahl der Bauform den Bezug auf frĂŒhere DenkmĂ€ler herstellen und damit den Verstorbenen in eine bestimmte Tradition stellen oder aber grundlegende neue Formen finden und so seine besondere Position betonen. Ebenso untersucht wird der Einfluss der GrĂ€ber auf das Bild der Nachwelt von der Person des Herrschers und ihre Instrumentalisierung durch die Nachfolger zur Stabilisierung der eigenen Macht

    Identification of FOXP1 Deletions in Three Unrelated Patients with Mental Retardation and Significant Speech and Language Deficits

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    Mental retardation affects 2-3% of the population and shows a high heritability. Neurodevelopmental disorders that include pronounced impairment in language and speech skills occur less frequently. For most cases, the molecular basis of mental retardation with or without speech and language disorder is unknown due to the heterogeneity of underlying genetic factors. We have used molecular karyotyping on 1523 patients with mental retardation to detect copy number variations (CNVs) including deletions or duplications. These studies revealed three heterozygous overlapping deletions solely affecting the forkhead box P1 (FOXP1) gene. All three patients had moderate mental retardation and significant language and speech deficits. Since our results are consistent with a de novo occurrence of these deletions, we considered them as causal although we detected a single large deletion including FOXP1 and additional genes in 4104 ancestrally matched controls. These findings are of interest with regard to the structural and functional relationship between FOXP1 and FOXP2. Mutations in FOXP2 have been previously related to monogenic cases of developmental verbal dyspraxia. Both FOXP1 and FOXP2 are expressed in songbird and human brain regions that are important for the developmental processes that culminate in speech and language. ©2010 Wiley-Liss, Inc

    A study of the possibility of sprites in the atmospheres of other planets

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    Sprites are a spectacular type of transient luminous events (TLE) which occur above thunderstorms immediately after lightning. They have shapes of giant jellyfish, carrots or columns and last tens of milliseconds. In Earth's atmosphere, sprites mostly emit in red and blue wavelengths from excited N2 and N2+ and span a vertical range between 50 and 90 km above the surface. The emission spectra, morphology and occurrence heights of sprites reflect the properties of the planetary atmosphere they inhabit and are related to the intensity of the initiating parent lightning.. This paper presents results of theoretical calculations of the expected occurrence heights of sprites above lightning discharges in the CO2 atmosphere of Venus, the N2 atmosphere of Titan and the H2-He atmosphere of Jupiter. The expected emission features are presented and the potential of detecting sprites in planetary atmospheres by orbiting spacecraft is discussed.Comment: 26 pages, 4 figures, to appear in J. Geophys. Res. - Planet
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