Stability of resilience in times of the COVID‐19 pandemic

There is disagreement among researchers regarding the conceptualization of resilience as a dynamic state or stable trait. Aiming to shed light on the state-versus-trait debate, we explored the stability and construct validity of four of the most frequently utilized state or trait resilience scales in a longitudinal assessment. Additionally, we examined the predictive validity of these scales. Our study was conducted before and during the COVID-19 pandemic, which served as collectively experienced adversity. Correlations among the resilience scales and among resilience scales and Big Five personality traits were strong. All except one scale showed high test-retest correlations. Experience of an additional critical life event during the pandemic led to an increase in resilience. Other than in cross-sectional studies, associations between resilience and psychological distress were weak, because personality and baseline psychological distress were controlled for. Nevertheless, next to personality, resilience explained additional variance in distress change. Our results show relatively high stability of resilience overall. Yet, they also confirm dynamic resilience features, suggesting that resilience change occurs with significant adversity, leading to improved adaptation. To gauge the true association between resilience and mental health, baseline levels of these variables as well as personality traits should be considered

Resilience and personality as predictors of the biological stress load during the first wave of the Covid-19 pandemic in Germany

Since the Covid-19 outbreak, pandemic-specific stressors have potentiated the-already severe-stress load across the world. However, stress is more than an adverse state, and chronic exposure is causally involved in the development of mental and physical disease. We ask the question whether resilience and the Big Five personality traits predict the biological stress response to the first lockdown in Germany. In a prospective, longitudinal, observational study, N = 80 adult volunteers completed an internet-based survey prior to the first Covid-19-related fatality in Germany (T0), during the first lockdown period (T1), and during the subsequent period of contact restrictions (T2). Hair strands for the assessment of systemic cortisol and cortisone levels were collected at T2. Higher neuroticism predicted higher hair cortisol, cortisone and subjective stress levels. Higher extraversion predicted higher hair cortisone levels. Resilience showed no effects on subjective or physiological stress markers. Our study provides longitudinal evidence that neuroticism and extraversion have predictive utility for the accumulation of biological stress over the course of the pandemic. While in pre-pandemic times individuals high in neuroticism are typically at risk for worse health outcomes, extraverted individuals tend to be protected. We conclude that, in the pandemic context, we cannot simply generalize from pre-pandemic knowledge. Neurotic individuals may currently suffer due to their general emotional lability. Extraverted individuals may primarily be socially stressed. Individualized stress management programs need to be developed, and offered in a lockdown-friendly format, to minimize the stress burden caused by Covid-19 or future pandemics and to protect the most severely affected individuals from the development of stress-associated disease

Definition of critical conditions for obtaining of a macromodel of ceramic matrix composites

The necessity for development of an approach to studying the phase composition and physico-chemical processes occurring during the firing of ceramic materials with a matrix structure based on technogenic and natural materials is substantiated. The study results on definition of critical conditions for obtaining of a ceramic matrix composites macromodel are presented

BIOCONTROL OF PHYTOPHTHORA CINNAMOMI ON AVOCADO: IDENTIFICATION AND FIELD TESTING OF LOCAL NATURAL ANTAGONISTS, AND EVALUATION OF ROOTSTOCKS FOR RESISTANCE

Abstract Soils suppressive to root rot of avocado (caused by Phytophthora cinnamomi), were first identified in South Africa in 1990. Mcro-organisms from these soils were tested for in vitro antagonism to Phytophthora cinnamomi and subsequently evaluated for suppression of root rot of avocado seedling plants in a mistbed. Three fungal antagonists, Paecilomyces filacinus, Aspergillus candidus and Trichoderma hamatum were effective in suppressing root rot. These antagonists have been evaluated since 1992 for control of root rot in avocado trees in the field. Populations of the antagonists have been found to increase in the root zone of newly planted trees (after antagonist treatment in the nursery and in the orchard) and in the root zone of established Hass and Fuerte trees planted in 1981 and 1980 (after antagonist treatment in the orchard). In an isolated planting site consisting of various ungrafted avocado rootstocks (eg. G1033, Dusa, Latas, D9, Duke 7, Barr Duke, Thomas, Velvic) trees undergo open pollination. Seeds from this orchard, situated at Westfalia Estate, are germinated and the seedlings evaluated for resistance to root rot in a mistbed. A number of successful selections have been made and these are being clonally propagated and grafted with Hass. These trees are to be planted in a root rot infested field site where they will be evaluated for yield and resistance to root rot

Thermodynamical Consistent Modeling and Analysis of Nematic Liquid Crystal Flows

The general Ericksen-Leslie system for the flow of nematic liquid crystals is reconsidered in the non-isothermal case aiming for thermodynamically consistent models. The non-isothermal model is then investigated analytically. A fairly complete dynamic theory is developed by analyzing these systems as quasilinear parabolic evolution equations in an $L^p-L^q$-setting. First, the existence of a unique, local strong solution is proved. It is then shown that this solution extends to a global strong solution provided the initial data are close to an equilibrium or the solution is eventually bounded in the natural norm of the underlying state space. In these cases, the solution converges exponentially to an equilibrium in the natural state manifold

Vorhersage von reaktivem Stofftransport in porösen Medien auf Basis unabhängiger Beobachtungen mit X-Ray µ-CT

Der reaktive Transport und die Transformation von gelösten organischen Substanzen beeinflussen die Funktionen des Bodens in maßgeblicher Weise. Eine Einschätzung dieser Funktionen ist daher an ein quantitatives Verständnis der Transportprozesse gebunden, um die Ausbreitung von organischen Substanzen voraussagen zu können. Die hierfür geeigneten Modelle enthalten jedoch häufig eine Vielzahl unbekannter Parameter, die durch Modellinversion bestimmt werden. Diese Herangehensweise spiegelt nicht notwendigerweise eine physikalisch sinnvolle Parametrisierung wider und verhindert damit realistische Prognosen. Das Ziel dieser Studie ist die von Transportdaten unabhängige Bestimmung der reaktiven Transportparameter. Um Transport unter möglichst konstanten Randbedingungen beobachten zu können, führten wir Säulenversuche mit Schüttungen wohldefinierter Mineralzusammensetzung (Glas, Quarz und Goethit) durch. Teile der Oberflächen wurden dabei homogen mit Goethit beschichtet. Als Versuchslösungen kamen konservative Tracer (NaCl) zur Charakterisierung des Fließfeldes sowie reaktive Tracer (Phthalsäure) zur Veranschaulichung von Adsorption an der Festphase zum Einsatz. Der Porenraum und die Mineralverteilung der Säulen wurden mittels X-Ray µ-CT dreidimensional erfasst und relevante morphologische Parameter extrahiert (Porengrößenverteilung, Vernetzung, Oberfläche). Unter Verwendung dieser Parameter wurde anschließend ein Porennetzwerkmodell erstellt, welches die gleichen morphologischen Charakteristika aufweist wie der tatsächliche Porenraum. Auf diese Weise gelang die Vorhersage des konservativen Stofftransports bereits ohne die Verwendung eines kontinuumskaligen Dispersionsparameters. Im nächsten Schritt werden Interaktionsparameter der verwendeten Sorbat/Sorbenten-Mischung in Schüttelversuchen bestimmt und in die Modellierung mit einbezogen. Auf diesem Weg wird sich zeigen, ob auch der reaktive Transport unabhängig von Durchbruchsdaten nachzuvollziehen ist

The ℓs\ell^s-boundedness of a family of integral operators on UMD Banach function spaces

We prove the $\ell^s$-boundedness of a family of integral operators with an operator-valued kernel on UMD Banach function spaces. This generalizes and simplifies earlier work by Gallarati, Veraar and the author, where the $\ell^s$-boundedness of this family of integral operators was shown on Lebesgue spaces. The proof is based on a characterization of $\ell^s$-boundedness as weighted boundedness by Rubio de Francia.Comment: 13 pages. Generalization of arXiv:1410.665

On thermodynamically consistent Stefan problems with variable surface energy

A thermodynamically consistent two-phase Stefan problem with temperature-dependent surface tension and with or without kinetic undercooling is studied. It is shown that these problems generate local semiflows in well-defined state manifolds. If a solution does not exhibit singularities, it is proved that it exists globally in time and converges towards an equilibrium of the problem. In addition, stability and instability of equilibria is studied. In particular, it is shown that multiple spheres of the same radius are unstable if surface heat capacity is small; however, if kinetic undercooling is absent, they are stable if surface heat capacity is sufficiently large.Comment: To appear in Arch. Ration. Mech. Anal. The final publication is available at Springer via http://dx.doi.org/10.1007/s00205-015-0938-y. arXiv admin note: substantial text overlap with arXiv:1101.376