Mechanically-driven Stem Cell Separation in Tissues caused by Proliferating Daughter Cells

The homeostasis of epithelial tissue relies on a balance between the self-renewal of stem cell populations, cellular differentiation, and loss. Although this balance needs to be tightly regulated to avoid pathologies, such as tumor growth, the regulatory mechanisms, both cell-intrinsic and collective, which ensure tissue steady-state are still poorly understood. Here, we develop a computational model that incorporates basic assumptions of stem cell renewal into distinct populations and mechanical interactions between cells. We find that the model generates unexpected dynamic features: stem cells repel each other in the bulk tissue and are thus found rather isolated, as in a number of in vivo contexts. By mapping the system onto a gas of passive Brownian particles with effective repulsive interactions, that arise from the generated flows of differentiated cells, we show that we can quantitatively describe such stem cell distribution in tissues. The interaction potential between a pair of stem cells decays exponentially with a characteristic length that spans several cell sizes, corresponding to the volume of cells generated per stem cell division. Our findings may help understanding the dynamics of normal and cancerous epithelial tissues

Kompatibilität und Relevanz von Social Media in der mittelständischen Unternehmenspraxis: Ergebnisbericht einer empirischen Untersuchung

Die Nutzung von Social Media zu Unternehmenszwecken ist mittlerweile gängige Praxis. Sowohl Großunternehmen als auch zunehmend der Mittelstand setzen soziale Medien ein, um einerseits die Kollaboration mit internen und externen Stakeholdern zu fördern und um andererseits insbesondere ihre Kommunikationsprozesse sowohl innerhalb als auch außerhalb des Unternehmens zu optimieren. Weitgehend unberücksichtigt bleiben dabei insbesondere im Mittelstand bislang die Besonderheiten dieser Unternehmen, die einen Einsatz von Social Media sowohl begünstigen als auch diesem eher entgegenstehen können. Der vorliegende Forschungsbericht ist das Ergebnis einer Studie zu den unternehmenstypabhängigen Nutzungspotenzialen von Social Media im Mittelstand. Er soll einen Einblick in die Kompatibilität von Social Media mit den Charakteristika mittelständischer Unternehmenstypen sowie in die Nutzungspotenziale von Social Media in unterschiedlichen Anwendungsbereichen mittelständischer Unternehmen geben

Kompatibilität und Relevanz von Social Media in der mittelständischen Unternehmenspraxis: Materialien zur empirischen Untersuchung

Die Nutzung von Social Media zu Unternehmenszwecken ist mittlerweile gängige Praxis. Sowohl Großunternehmen als auch zunehmend der Mittelstand setzen soziale Medien ein, um einerseits die Kollaboration mit internen und externen Stakeholdern zu fördern und um andererseits insbesondere ihre Kommunikationsprozesse sowohl innerhalb als auch außerhalb des Unternehmens zu optimieren. Weitgehend unberücksichtigt bleiben dabei insbesondere im Mittelstand bislang die Besonderheiten dieser Unternehmen, die einen Einsatz von Social Media sowohl begünstigen als auch diesem eher entgegenstehen können. Die vorliegende Sammlung von Materialien ist das Ergebnis einer Studie zu den unternehmenstypabhängigen Nutzungspotenzialen von Social Media im Mittelstand. Sie stellt die wesentlichen Erkenntnisse in grafisch kondensierter Form dar und bildet die Grundlage für den vorab als Band 181 in der Reihe Bamberger Betriebswirtschaftliche Beiträge (BBB) veröffentlichten Ergebnisbericht

A Practical Second-Order Fault Attack against a Real-World Pairing Implementation

Several fault attacks against pairing-based cryptography have been described theoretically in recent years. Interestingly, none of these have been practically evaluated. We accomplished this task and prove that fault attacks against pairing-based cryptography are indeed possible and are even practical — thus posing a serious threat. Moreover, we successfully conducted a second-order fault attack against an open source implementation of the eta pairing on an AVR XMEGA A1. We injected the first fault into the computation of the Miller Algorithm and applied the second fault to skip the final exponentiation completely. We introduce a low-cost setup that allowed us to generate multiple independent faults in one computation. The setup implements these faults by clock glitches which induce instruction skips. With this setup we conducted the first practical fault attack against a complete pairing computation

Associations between BMI and the FTO Gene Are Age Dependent: Results from the GINI and LISA Birth Cohort Studies up to Age 6 Years

Objective: The association between polymorphisms in intron 1 of the fat mass and obesity associated gene (FTO) and obesity-related traits is one of the most robust associations reported for complex traits and is established both in adults and children. However, little is known about the longitudinal dynamics of these polymorphisms on body mass index (BMI), overweight, and obesity. Methods: This study is based on the 2,732 full-term neonates of the German GINI-plus and LISA-plus birth cohorts, for whom genotyping data on the FTO variants rs1558902 (T>A) or rs9935401 (G>A) were available. Children were followed from birth up to age 6 years. Up to 9 anthropometric measurements of BMI were obtained. Fractional-Polynomial-Generalized-Estimation-Equation modeling was used to assess developmental trends and their potential dependence on genotype status. Results: We observed no evidence for BMI differences between genotypes of both variants for the first 3 years of life. However, from age 3 years onwards, we noted a higher BMI for the homozygous minor alleles carriers in comparison to the other two genotype groups. However, evidence for statistical significance was reached from the age of 4 years onwards. Conclusions: This is one of the first studies investigating in detail the development of BMI depending on FTO genotype between birth and the age of 6 years in a birth cohort not selected for the phenotype studied. We observed that the association between BMI and FTO genotype evolves gradually and becomes descriptively detectable from the age of 3 years onwards

An expert consensus on the recommendations for the use of biomarkers in Fabry disease

Fabry disease is an X-linked lysosomal storage disorder caused by the accumulation of glycosphingolipids in various tissues and body fluids, leading to progressive organ damage and life-threatening complications. Phenotypic classification is based on disease progression and severity and can be used to predict outcomes. Patients with a classic Fabry phenotype have little to no residual α-Gal A activity and have widespread organ involvement, whereas patients with a later-onset phenotype have residual α-Gal A activity and disease progression can be limited to a single organ, often the heart. Diagnosis and monitoring of patients with Fabry disease should therefore be individualized, and biomarkers are available to support with this. Disease-specific biomarkers are useful in the diagnosis of Fabry disease; non-disease-specific biomarkers may be useful to assess organ damage. For most biomarkers it can be challenging to prove they translate to differences in the risk of clinical events associated with Fabry disease. Therefore, careful monitoring of treatment outcomes and collection of prospective data in patients are needed. As we deepen our understanding of Fabry disease, it is important to regularly re-evaluate and appraise published evidence relating to biomarkers. In this article, we present the results of a literature review of evidence published between February 2017 and July 2020 on the impact of disease-specific treatment on biomarkers and provide an expert consensus on clinical recommendations for the use of those biomarkers.publishedVersio

Risk factors and outcomes of unrecognised endobronchial intubation in major trauma patients

Background Emergency tracheal intubation during major trauma resuscitation may be associated with unrecognised endobronchial intubation. The risk factors and outcomes associated with this issue have not previously been fully defined. Methods We retrospectively analysed adult patients admitted directly from the scene to the ED of a single level 1 trauma centre, who received either prehospital or ED tracheal intubation prior to initial whole-body CT from January 2008 to December 2019. Our objectives were to describe tube-to- carina distances (TCDs) via CT and to assess the risk factors and outcomes (mortality, length of intensive care unit stay and mechanical ventilation) of patients with endobronchial intubation (TCD <0 cm) using a multivariable model. Results We included 616 patients and discovered 26 (4.2%) cases of endobronchial intubation identified on CT. Factors associated with an increased risk of endobronchial intubations were short body height (OR per 1 cm increase 0.89; 95% CI 0.84 to 0.94; p≤0.001), a high body mass index (OR 1.14; 95% CI 1.04 to 1.25; p=0.005) and ED intubation (OR 3.62; 95% CI 1.39 to 8.90; p=0.006). Eight of 26 cases underwent tube thoracostomy, four of whom had no evidence of underlying chest injury on CT. There was no statistically significant difference in mortality or length of stay although the absolute number of endobronchial intubations was small. Conclusions Short body height and high body mass index were associated with endobronchial intubation. Before considering tube thoracostomy in intubated major trauma patients suspected of pneumothorax, the possibility of unrecognised endobronchial intubation should be considered

A Framework to Select Parameters for Lattice-Based Cryptography

Selecting parameters in lattice-based cryptography is a challenging task, which is essentially accomplished using one of two approaches. The first (very common) approach is to derive parameters assuming that the desired security level is equivalent to the bit hardness of the underlying lattice problem, ignoring the gap implied by available security reductions. The second (barely used) approach takes the gap and thus the security reduction into account. In this work, we investigate how efficient lattice-based schemes are if they respect existing security reductions. Thus, we present a framework to systematically select parameters for any lattice-based scheme using either approaches. We apply our methodology to the schemes by Lindner and Peikert (LP), by El Bansarkhani (LARA), and by Ducas et al. (BLISS). We analyze their security reductions and derive a gap of 2, 3, and 63 bits, respectively. We show how parameters impact the schemes\u27 efficiency when involving these gaps