Володимир Антонович і Дмитро Яворницький: до історії наукових і особистих взаємин

Невід’ємною складовою інтелектуальної історії є дослідження міжособистісних стосунків науковців. Особливо, якщо кожен із них є знаковою постаттю, уособленням поєднання високого професіоналізму і патріотичної громадянської позиції. Дослідження останнього часу, присвячені В.Б.Антоновичу визначають його безперечно новаторську місію у складанні першої науково доказової національно-демократичної концепції минулого України та розробленні періодизації вітчизняного історичного процесу

Multiscale mechanical analysis of the elastic modulus of skin

The mechanical properties of the skin determine tissue function and regulate dermal cell behavior. Yet measuring these properties remains challenging, as evidenced by the large range of elastic moduli reported in the literature-from below one kPa to hundreds of MPa. Here, we reconcile these disparate results by dedicated experiments at both tissue and cellular length scales and by computational models considering the multiscale and multiphasic tissue structure. At the macroscopic tissue length scale, the collective behavior of the collagen fiber network under tension provides functional tissue stiffness, and its properties determine the corresponding elastic modulus (100-200 kPa). The compliant microscale environment (0.1-10 kPa), probed by atomic force microscopy, arises from the ground matrix without engaging the collagen fiber network. Our analysis indicates that indentation-based elasticity measurements, although probing tissue properties at the cell-relevant length scale, do not assess the deformation mechanisms activated by dermal cells when exerting traction forces on the extracellular matrix. Using dermal-equivalent collagen hydrogels, we demonstrate that indentation measurements of tissue stiffness do not correlate with the behavior of embedded dermal fibroblasts. These results provide a deeper understanding of tissue mechanics across length scales with important implications for skin mechanobiology and tissue engineering. STATEMENT OF SIGNIFICANCE: Measuring the mechanical properties of the skin is essential for understanding dermal cell mechanobiology and designing tissue-engineered skin substitutes. However, previous results reported for the elastic modulus of skin vary by six orders of magnitude. We show that two distinct deformation mechanisms, related to the tension-compression nonlinearity of the collagen fiber network, can explain the large variations in elastic moduli. Furthermore, we show that microscale indentation, which is frequently used to assess the stiffness perceived by cells, fails to engage the fiber network, and therefore cannot predict the behavior of dermal fibroblasts in stiffness-tunable fibrous hydrogels. This has important implications for how to measure and interpret the mechanical properties of soft tissues across length scales

Assessing teamwork competence

Abstract. Background: In recent years, organizations of all types have undergone major changes, and teamwork is one of them. This way of working generates greater profits for an organization. This article aims to assess the teamwork competence of the employees of various Spanish companies in order to determine how effective the team members are in their professional actions. Method: We contacted 55 teams from different organizations and obtained a non-probabilistic sample comprised of 55 participants (subjects tested) and 218 observers (evaluators: coordinators and co-workers). The instrument used for data collection was the Teamwork Rubric (Torrelles, 2011) and data analysis was based on 360º feedback. Results: 80% of the teams analyzed obtained median scores for teamwork competence that were greater than 3, whereas 20% obtained scores between 2 and 3. Conclusions: The results showed that the workers in the companies studied had not fully acquired teamwork competence. It is necessary to find training solutions to improve their level of acquisition, particularly the dimensions of performance and regulation. Resumen: Evaluación de la competencia de trabajo en equipo. Antecedentes: En los últimos años las organizaciones han experimentado múltiples cambios y el trabajo en equipo es uno de ellos. Esta manera de trabajar genera más beneficio en las organizaciones. El presente artículo tiene como objetivo evaluar la competencia de trabajo en equipo de los empleados de diferentes empresas españolas para conocer las debilidades y potencialidades de los equipos en su acción profesional. Método: Se ha contactado con 55 equipos procedentes de diferentes organizaciones configurando así una muestra de carácter no probabilístico formada por 55 participantes (sujetos evaluados) y 218 observadores (sujetos evaluadores: coordinadores y compañeros de trabajo). El instrumento de recogida de los datos es la Rúbrica de Trabajo en Equipo (Torrelles, 2011) y su aplicación se ejecuta a través del método de evaluación 360º. Resultados: El 80% de los trabajadores muestran que tienen una media de 3 o superior en el nivel de adquisición de la competencia de trabajo en equipo, el 20% restante se encuentran entre 2 y 3. Conclusiones: Los resultados muestran que los trabajadores de las empresas españolas no tienen adquirida la competencia de trabajo en equipo en toda su globalidad, pues dimensiones como la regulación y la ejecución necesitan ser mejoradas

A model for the compressible, viscoelastic behavior of human amnion addressing tissue variability through a single parameter

A viscoelastic, compressible model is proposed to rationalize the recently reported response of human amnion in multiaxial relaxation and creep experiments. The theory includes two viscoelastic contributions responsible for the short- and long-term time- dependent response of the material. These two contributions can be related to physical processes: water flow through the tissue and dissipative characteristics of the collagen fibers, respectively. An accurate agreement of the model with the mean tension and kinematic response of amnion in uniaxial relaxation tests was achieved. By variation of a single linear factor that accounts for the variability among tissue samples, the model provides very sound predictions not only of the uniaxial relaxation but also of the uniaxial creep and strip-biaxial relaxation behavior of individual samples. This suggests that a wide range of viscoelastic behaviors due to patient-specific variations in tissue composition

Time-dependent mechanical behavior of human amnion: Macroscopic and microscopic characterization

Characterizing the mechanical response of the human amnion is essential to understand and to eventually prevent premature rupture of fetal membranes. In this study, a large set of macroscopic and microscopic mechanical tests have been carried out on fresh unfixed amnion to gain insight into the time-dependent material response and the underlying mechanisms. Creep and relaxation responses of amnion were characterized in macroscopic uniaxial tension, biaxial tension and inflation configurations. For the first time, these experiments were complemented by microstructural information from nonlinear laser scanning microscopy performed during in situ uniaxial relaxation tests. The amnion showed large tension reduction during relaxation and small inelastic strain accumulation in creep. The short-term relaxation response was related to a concomitant in-plane and out-of-plane contraction, and was dependent on the testing configuration. The microscopic investigation revealed a large volume reduction at the beginning, but no change of volume was measured long-term during relaxation. Tension–strain curves normalized with respect to the maximum strain were highly repeatable in all configurations and allowed the quantification of corresponding characteristic parameters. The present data indicate that dissipative behavior of human amnion is related to two mechanisms: (i) volume reduction due to water outflow (up to ∼20 s) and (ii) long-term dissipative behavior without macroscopic deformation and no systematic global reorientation of collagen fibers

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

Taxonomy of the order Bunyavirales : second update 2018

In October 2018, the order Bunyavirales was amended by inclusion of the family Arenaviridae, abolishment of three families, creation of three new families, 19 new genera, and 14 new species, and renaming of three genera and 22 species. This article presents the updated taxonomy of the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV).Non peer reviewe