Künstliches feedback für oberschenkelamputierte; theoretische Analyse - Artificial feedback for transfemoral amputees: Theoretical analysis

Dieser Beitrag untersucht auf Basis von Modellen der menschlichen Wahrnehmung den Einfluss künstlichen sensorischen Feedbacks auf posturale Kontrolle und Gangsymmetrie von Oberschenkelamputierten. In der Standphase wird ein vereinfachtes, statisches neuromechanisches Modell verwendet, in der Schwungphase ein Erweitertes Kalman-Filter, das dynamische Effekte berücksichtigt. Die Simulation lässt den Schluss zu, dass Rückmeldung des Fußdruckpunktes während der Standphase die Wahrnehmung verbessern könnte, künstliches Feedback während der Schwungphase jedoch nicht von Vorteil ist. Eine klinische Fallstudie wäre nötig, um die in der Simulation beobachteten Effekte sensorischen Feedbacks in der praktischen Anwendung mit Amputierten zu uberprufenBiomechanical EngineeringMechanical, Maritime and Materials Engineerin

Genome interplay in the grain transcriptome of hexaploid bread wheat

Allohexaploid bread wheat (Triticum aestivum L.) provides approximately 20% of calories consumed by humans. Lack of genome sequence for the three homeologous and highly similar bread wheat genomes (A, B, and D) has impeded expression analysis of the grain transcriptome. We used previously unknown genome information to analyze the cell type-specific expression of homeologous genes in the developing wheat grain and identified distinct co-expression clusters reflecting the spatiotemporal progression during endosperm development. We observed no global but cell type-and stage-dependent genome dominance, organization of the wheat genome into transcriptionally active chromosomal regions, and asymmetric expression in gene families related to baking quality. Our findings give insight into the transcriptional dynamics and genome interplay among individual grain cell types in a polyploid cereal genome

Ancient hybridizations among the ancestral genomes of bread wheat

The allohexaploid bread wheat genome consists of three closely related subgenomes (A, B, and D), but a clear understanding of their phylogenetic history has been lacking. We used genome assemblies of bread wheat and five diploid relatives to analyze genome-wide samples of gene trees, as well as to estimate evolutionary relatedness and divergence times. We show that the A and B genomes diverged from a common ancestor similar to 7 million years ago and that these genomes gave rise to the D genome through homoploid hybrid speciation 1 to 2 million years later. Our findings imply that the present-day bread wheat genome is a product of multiple rounds of hybrid speciation (homoploid and polyploid) and lay the foundation for a new framework for understanding the wheat genome as a multilevel phylogenetic mosaic