Using Genetic Algorithms for Model Selection in Graphical Models

Model selection in graphical models is still not fully investigated. The main difficulty lies in the search space of all possible models which grows more than exponentially with the number of variables involved. Here, genetic algorithms seem to be a reasonable strategy to find good fitting models for a given data set. In this paper, we adapt them to the problem of model search in graphical models and discuss their performance by conducting simulation studies

GraphFitI - A computer program for graphical chain models

Fitting a graphical chain model to a multivariate data set consists of different steps some of which being rather tedious. The paper outlines the basic features and overall architecture of the computer program GraphFitI which provides the application of a selection strategy for fitting graphical chain models and for visualising the resulting models as a graph. It additionally supports the user at the different steps of the analysis by an integrated help system

Creative Togetherness. A Joint-Methods Analysis of Collaborative Artistic Performance.

In the present study, we combined first-, second-, and third-person levels of analysis to explore the feeling of being and acting together in the context of collaborative artistic performance. Following participation in an international competition held in Czech Republic in 2018, a team of ten artistic swimmers took part in the study. First, a self-assessment instrument was administered to rate the different aspects of togetherness emerging from their collective activity; second, interviews based on video recordings of their performance were conducted individually with all team members; and third, the performance was evaluated by external artistic swimming experts. By combining these levels of analysis in different ways, we explore how changes in togetherness and lived experience in individual behavior may shape, disrupt, and (re-)stabilize joint performance. Our findings suggest that the experience of being and acting together is transient and changing, often alternating phases of decrease and increase in felt togetherness that can be consistently recognized by swimmers and external raters

Jamming in Embryogenesis and Cancer Progression

The ability of tissues and cells to move and rearrange is central to a broad range of diverse biological processes such as tissue remodeling and rearrangement in embryogenesis, cell migration in wound healing, or cancer progression. These processes are linked to a solidlike to fluid-like transition, also known as unjamming transition, a not rigorously defined framework that describes switching between a stable, resting state and an active, moving state. Various mechanisms, that is, proliferation and motility, are critical drivers for the (un) jamming transition on the cellular scale. However, beyond the scope of these fundamental mechanisms of cells, a unifying understanding remains to be established. During embryogenesis, the proliferation rate of cells is high, and the number density is continuously increasing, which indicates number-density-driven jamming. In contrast, cells have to unjam in tissues that are already densely packed during tumor progression, pointing toward a shape-driven unjamming transition. Here, we review recent investigations of jamming transitions during embryogenesis and cancer progression and pursue the question of how they might be interlinked. We discuss the role of density and shape during the jamming transition and the different biological factors driving it

Axonal Ensheathment and Intercellular Barrier Formation in Drosophila

Glial cells are critical players in every major aspect of nervous system development, function, and disease. Other than their traditional supportive role, glial cells perform a variety of important functions such as myelination, synapse formation and plasticity, and establishment of blood–brain and blood–nerve barriers in the nervous system. Recent studies highlight the striking functional similarities between Drosophila and vertebrate glia. In both systems, glial cells play an essential role in neural ensheathment thereby isolating the nervous system and help to create a local ionic microenvironment for conduction of nerve impulses. Here, we review the anatomical aspects and the molecular players that underlie ensheathment during different stages of nervous system development in Drosophila and how these processes lead to the organization of neuroglial junctions. We also discuss some key aspects of the invertebrate axonal ensheathment and junctional organization with that of vertebrate myelination and axon–glial interactions. Finally, we highlight the importance of intercellular junctions in barrier formation in various cellular contexts in Drosophila. We speculate that unraveling the genetic and molecular mechanisms of ensheathment across species might provide key insights into human myelin-related disorders and help in designing therapeutic interventions

Teorias da Aleatoriedade

Este trabalho apresenta uma revisão bibliográfica sobre a definição de “seqüência aleatória”. Nós enfatizamos a definição de Martin-Löf e a definição baseada em incompressividade (complexidade de Kolmogorov). Complexidade de Kolmogorov é uma teoria sofisticada e profunda da informação e da aleatoriedade baseada na máquina de Turing. Estas duas definições resolvem todos os problemas das outras abordagens e satisfazem o nosso conceito intuitivo de aleatoriedade, sendo matematicamente corretas. Adicionalmente, apresentamos a abordagem de Schnorr que inclui um requisito de efetividade (computabilidade) em sua definição. São apresentadas as relações entre estas diversas definições de forma crítica. Palavras-chave: aleatoriedade, complexidade de Kolmogorov, máquina de Turing, computabilidade, probabilidade.This work is a survey about the definition of “random sequence”. We emphasize the definition of Martin-Löf and the definition based on incompressibility (Kolmogorov complexity). Kolmogorov complexity is a profound and sofisticated theory of information and randomness based on Turing machines. These two definitions solve all the problems of the other approaches, satisfying our intuitive concept of randomness, and both are mathematically correct. Furthermore, we show the Schnorr’s approach, that includes a requisite of effectiveness (computability) in his definition. We show the relations between all definitions in a critical way. Keywords: randomness, Kolmogorov complexity, Turing machine, computability, probability

Control of starch branching in barley defined through differential RNAi suppression of starch branching enzyme IIa and IIb

The roles of starch branching enzyme (SBE, EC 2.4.1.18) IIa and SBE IIb in defining the structure of amylose and amylopectin in barley (Hordeum vulgare) endosperm were examined. Barley lines with low expression of SBE IIa or SBE IIb, and with the low expression of both isoforms were generated through RNA-mediated silencing technology. These lines enabled the study of the role of each of these isoforms in determining the amylose content, the distribution of chain lengths, and the frequency of branching in both amylose and amylopectin. In lines where both SBE IIa and SBE IIb expression were reduced by >80%, a high amylose phenotype (>70%) was observed, while a reduction in the expression of either of these isoforms alone had minor impact on amylose content. The structure and properties of the high amylose starch resulting from the concomitant reduction in the expression of both isoforms of SBE II in barley were found to approximate changes seen in amylose extender mutants of maize, which result from lesions eliminating expression of the SBE IIb gene. Amylopectin chain length distribution analysis indicated that both SBE IIa and SBE IIb isoforms play distinct roles in determining the fine structure of amylopectin. A significant reduction in the frequency of branches in amylopectin was noticed only when both SBE IIa and SBE IIb were reduced, whereas there was a significant increase in the branching frequency of amylose when SBE IIb alone was reduced. Functional interactions between SBE isoforms are suggested, and a possible inhibitory role of SBE IIb on other SBE isoforms is discussed

Über eine Klasse polynomialer Scharen selbstadjungierter Operatoren im Hilbertraum

HEK293A cells expressing either mouse MOG (mMOG) or rat MOG (rMOG) C terminally tagged with EGFP. (DOCX 2792 kb

Long‑term results of the augmented PFNA: a prospective multicenter trial

Producción CientíficaPertrochanteric fractures are increasing and their operative treatment remains under discussion. Failures needing reoperations such as a cut-out are reported to be high and are associated with multiple factors including poor bone quality, poor fracture reduction and improper implant placement. The PFNA® with perforated blade offers an option for standardized cement augmentation with a PMMA cement to provide more stability to the fracture fixation. It remains unclear if the augmentation of this implant does any harm in a longer time span. This prospective multicenter study shows clinical and radiological results with this implant with a mean follow-up time of 15 months

A Laminin G-EGF-Laminin G Module in Neurexin IV Is Essential for the Apico-Lateral Localization of Contactin and Organization of Septate Junctions

Septate junctions (SJs) display a unique ultrastructural morphology with ladder-like electron densities that are conserved through evolution. Genetic and molecular analyses have identified a highly conserved core complex of SJ proteins consisting of three cell adhesion molecules Neurexin IV, Contactin, and Neuroglian, which interact with the cytoskeletal FERM domain protein Coracle. How these individual proteins interact to form the septal arrays that create the paracellular barrier is poorly understood. Here, we show that point mutations that map to specific domains of neurexin IV lead to formation of fewer septae and disorganization of SJs. Consistent with these observations, our in vivo domain deletion analyses identified the first Laminin G-EGF-Laminin G module in the extracellular region of Neurexin IV as necessary for the localization of and association with Contactin. Neurexin IV protein that is devoid of its cytoplasmic region is able to create septae, but fails to form a full complement of SJs. These data provide the first in vivo evidence that specific domains in Neurexin IV are required for protein-protein interactions and organization of SJs. Given the molecular conservation of SJ proteins across species, our studies may provide insights into how vertebrate axo-glial SJs are organized in myelinated axons