126 research outputs found

    Geometric Constraints and the Anatomical Interpretation of Twisted Plant Organ Phenotypes

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    The study of plant mutants with twisting growth in axial organs, which normally grow straight in the wild-type, is expected to improve our understanding of the interplay among microtubules, cellulose biosynthesis, cell wall structure, and organ biomechanics that control organ growth and morphogenesis. However, geometric constraints based on symplastic growth and the consequences of these geometric constraints concerning interpretations of twisted-organ phenotypes are currently underestimated. Symplastic growth, a fundamental concept in plant developmental biology, is characterized by coordinated growth of adjacent cells based on their connectivity through cell walls. This growth behavior implies that in twisting axial organs, all cell files rotate in phase around the organ axis, as has been illustrated for the Arabidopsis spr1 and twd1 mutants in this work. Evaluating the geometry of such organs, we demonstrate that a radial gradient in cell elongation and changes in cellular growth anisotropy must occur in twisting organs out of geometric necessity alone. In-phase rotation of the different cell layers results in a decrease of length and angle toward organ axis from the outer cell layers inward. Additionally, the circumference of each cell layer increases in twisting organs, which requires compensation through radial expansion or an adjustment of cell number. Therefore, differential cell elongation and growth anisotropy cannot serve as arguments for or against specific hypotheses regarding the molecular cause of twisting growth. We suggest instead, that based on mathematical modeling, geometric constraints in twisting organs are indispensable for the explanation of the causal connection of molecular and biomechanical processes in twisting as well as normal organs

    Laser-Induced-Fluorescence Detection of Nitric Oxide in High-Pressure Flames with A-X(0, 2) Excitation

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    Laser-induced fluorescence techniques have been used successfully for quantitative two-dimensional measurements of nitric oxide. The commonly applied D–X(0, 1) or A–X(0, 0) schemes are restricted to atmospheric-pressure flames and engines driven with gaseous fuels because of strong attenuation of the exciting laser beam by combustion intermediates. The properties of a detection scheme for which excitation in the nitric oxide A–X(0, 2) band was used were investigated. We discuss the advantages of the A–X(0, 2) system (excited at 247.95 nm) based on measurements in laminar premixed methane/air flames at 1–40 bars.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86764/1/Sick41.pd

    Report on the First Working Group Meeting of the “AG Marketing”

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    This contribution reports on the first meeting of the new formed working group “Data Analysis and Classification in Marketing (AG Marketing)” of the data science society (GfKl) held at the KIT, Karlsruhe, November 14th – 15th, 2019. The abstracts of the presentations given reflect the ongoing trend to exploit a large variety of digital data sources for marketing purposes and the need for advanced and innovative analysis methods

    Konvergenz und regulatorische Folgen. Gutachten im Auftrag der Rundfunkkommission der Länder

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    Zunehmende technische Konvergenz stellt die Medienregulierung ebenso vor neue Herausforderungen wie die Konvergenz bisher getrennter Medienbranchen. Grundsätzlich geht das Medienrecht noch von einer begriffsbasierten Regulierung anhand technischer Unterscheidungsmerkmale aus. Diese technischen Kriterien verschwimmen mit zunehmender Konvergenz und stellen immer weniger taugliche Anknüpfungspunkte für eine moderne Medienregulierung dar. Im Gutachten für die Rundfunkkommission der Länder werden diese Regelungsbereiche analysiert und auf ihr Optimierungspotenzial hin untersucht. Basis der Problemanalyse ist die Auswertung von Entscheidungen von Gerichten und Behörden, wissenschaftliche Analysen und Informationen aus den betroffenen Branchen. Das Gutachten soll damit auch als Vorbereitung der Bund-Länder-Gespräche zur Abstimmung ihrer jeweils einschlägigen gesetzlichen Regelungen dienen

    Comparison of integrative nature conservation in forest policy in Europe: a qualitative pilot study of institutional determinants

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    In this pilot study, we examine the relationship between the organisation of property rights and the economic importance of forestry on the one hand and the degree to which integrative nature conservation is formally implemented in forest policy on the other hand. Further, we are interested in whether political institutions moderate this relationship. We first offer a conceptualization of integrative nature conservation in forests and how to measure its implementation in law, ordinances and private agreements for a sample of European national and sub-national jurisdictions (Austria, Croatia, Finland, France, the Netherlands, Switzerland, Flanders, Baden-Württemberg and Piedmont). We subsequently try to assess the implementation of these rules and to relate them both to the structural characteristics of forestry and to an appraisal of pluralism in forest policy. Our qualitative analysis reveals that among the jurisdictions with a more centralized and corporatist forest policy, integrative nature conservation in forests tend to be less formally implemented the more corporatism dominates decision-making. It also confirms the expectation that among the more consensual jurisdictions with a strong forestry sector, rules tend to be less formally implemented. Further, the suspicion prevails that in the latter case, such rules are either complemented with exceptions for private forests or higher compensation. A more in-depth comparative examination is needed to further corroborate these findings

    Two New Loci for Body-Weight Regulation Identified in a Joint Analysis of Genome-Wide Association Studies for Early-Onset Extreme Obesity in French and German Study Groups

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    Meta-analyses of population-based genome-wide association studies (GWAS) in adults have recently led to the detection of new genetic loci for obesity. Here we aimed to discover additional obesity loci in extremely obese children and adolescents. We also investigated if these results generalize by estimating the effects of these obesity loci in adults and in population-based samples including both children and adults. We jointly analysed two GWAS of 2,258 individuals and followed-up the best, according to lowest p-values, 44 single nucleotide polymorphisms (SNP) from 21 genomic regions in 3,141 individuals. After this DISCOVERY step, we explored if the findings derived from the extremely obese children and adolescents (10 SNPs from 5 genomic regions) generalized to (i) the population level and (ii) to adults by genotyping another 31,182 individuals (GENERALIZATION step). Apart from previously identified FTO, MC4R, and TMEM18, we detected two new loci for obesity: one in SDCCAG8 (serologically defined colon cancer antigen 8 gene; p = 1.85610 x 10(-8) in the DISCOVERY step) and one between TNKS (tankyrase, TRF1-interacting ankyrin-related ADP-ribose polymerase gene) and MSRA (methionine sulfoxide reductase A gene; p = 4.84 x 10(-7)), the latter finding being limited to children and adolescents as demonstrated in the GENERALIZATION step. The odds ratios for early-onset obesity were estimated at similar to 1.10 per risk allele for both loci. Interestingly, the TNKS/MSRA locus has recently been found to be associated with adult waist circumference. In summary, we have completed a meta-analysis of two GWAS which both focus on extremely obese children and adolescents and replicated our findings in a large followed-up data set. We observed that genetic variants in or near FTO, MC4R, TMEM18, SDCCAG8, and TNKS/MSRA were robustly associated with early-onset obesity. We conclude that the currently known major common variants related to obesity overlap to a substantial degree between children and adults

    Structural characteristics and contractual terms of specialist palliative homecare in Germany

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    Background Multi-professional specialist palliative homecare (SPHC) teams care for palliative patients with complex symptoms. In Germany, the SPHC directive regulates care provision, but model contracts for each federal state are heterogeneous regarding staff requirements, cooperation with other healthcare providers, and financial reimbursement. The structural characteristics of SPHC teams also vary. Aim We provide a structured overview of the existing model contracts, as well as a nationwide assessment of SPHC teams and their structural characteristics. Furthermore, we explore whether these characteristics serve to find specifc patterns of SPHC team models, based on empirical data. Methods This study is part of the multi-methods research project “SAVOIR”, funded by the German Innovations Fund. Most model contracts are publicly available. Structural characteristics (e.g. number, professions, and affiliations of team members, and external cooperation) were assessed via an online database (“Wegweiser Hospiz- und Palliativversorgung”) based on voluntary information obtained from SPHC teams. All the data were updated by phone during the assessment process. Data were descriptively analysed regarding staff, cooperation requirements, and reimbursement schemes, while latent class analysis (LCA) was used to identify structural team models. Results Model contracts have heterogeneous contract partners and terms related to staff requirements (number and qualifications) and cooperation with other services. Fourteen reimbursement schemes were available, all combining different payment models. Of the 283 SPHC teams, 196 provided structural characteristics. Teams reported between one and 298 members (mean: 30.3, median: 18), mainly nurses and physicians, while 37.8% had a psychosocial professional as a team member. Most teams were composed of nurses and physicians employed in different settings; for example, staff was employed by the team, in private practices/nursing services, or in hospitals. Latent class analysis identified four structural team models, based on the team size, team members’ affiliation, and care organisation. Conclusion Both the contractual terms and teams’ structural characteristics vary substantially, and this must be considered when analysing patient data from SPHC. The identified patterns of team models can form a starting point from which to analyse different forms of care provision and their impact on care quality

    Accumulation of α-synuclein mediates podocyte injury in Fabry nephropathy

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    Current therapies for Fabry disease are based on reversing intracellular accumulation of globotriaosylceramide (Gb3) by enzyme replacement therapy (ERT) or chaperone-mediated stabilization of the defective enzyme, thereby alleviating lysosomal dysfunction. However, their effect in the reversal of end-organ damage, like kidney injury and chronic kidney disease, remains unclear. In this study, ultrastructural analysis of serial human kidney biopsies showed that long-term use of ERT reduced Gb3 accumulation in podocytes but did not reverse podocyte injury. Then, a CRISPR/Cas9–mediated α-galactosidase knockout podocyte cell line confirmed ERT-mediated reversal of Gb3 accumulation without resolution of lysosomal dysfunction. Transcriptome-based connectivity mapping and SILAC-based quantitative proteomics identified α-synuclein (SNCA) accumulation as a key event mediating podocyte injury. Genetic and pharmacological inhibition of SNCA improved lysosomal structure and function in Fabry podocytes, exceeding the benefits of ERT. Together, this work reconceptualizes Fabry-associated cell injury beyond Gb3 accumulation, and introduces SNCA modulation as a potential intervention, especially for patients with Fabry nephropathy.publishedVersio
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