Decomposition driven interface evolution for layers of binary mixtures: I. Model derivation and stratified base states

A dynamical model is proposed to describe the coupled decomposition and profile evolution of a free surface film of a binary mixture. An example is a thin film of a polymer blend on a solid substrate undergoing simultaneous phase separation and dewetting. The model is based on model-H describing the coupled transport of the mass of one component (convective Cahn-Hilliard equation) and momentum (Navier-Stokes-Korteweg equations) supplemented by appropriate boundary conditions at the solid substrate and the free surface. General transport equations are derived using phenomenological non-equilibrium thermodynamics for a general non-isothermal setting taking into account Soret and Dufour effects and interfacial viscosity for the internal diffuse interface between the two components. Focusing on an isothermal setting the resulting model is compared to literature results and its base states corresponding to homogeneous or vertically stratified flat layers are analysed.Comment: Submitted to Physics of Fluid

Geometric diagnostics of complex patterns: Spiral defect chaos

Motivated by the observation of spiral patterns in a wide range of physical, chemical, and biological systems, we present an automated approach that aims at characterizing quantitatively spiral-like elements in complex stripelike patterns. The approach provides the location of the spiral tip and the size of the spiral arms in terms of their arc length and their winding number. In addition, it yields the number of pattern components (Betti number of order 1), as well as their size and certain aspects of their shape. We apply the method to spiral defect chaos in thermally driven Rayleigh- Bénard convection and find that the arc length of spirals decreases monotonically with decreasing Prandtl number of the fluid and increasing heating. By contrast, the winding number of the spirals is nonmonotonic in the heating. The distribution function for the number of spirals is significantly narrower than a Poisson distribution. The distribution function for the winding number shows approximately an exponential decay. It depends only weakly on the heating, but strongly on the Prandtl number. Large spirals arise only for larger Prandtl numbers. In this regime the joint distribution for the spiral length and the winding number exhibits a three-peak structure, indicating the dominance of Archimedean spirals of opposite sign and relatively straight sections. For small Prandtl numbers the distribution function reveals a large number of small compact pattern components

Jumping-based asymmetries are negatively associated with jump, change of direction, and repeated sprint performance, but not linear speed, in adolescent handball athletes

The aim of the present study was to determine the association of multi-directional jumping asymmetries with measures of physical performance. Forty-two youth handball athletes (age: 16.0 ± 1.3 years; body height: 174.11 ± 7.3 cm; body mass: 70.49 ± 13.3 kg) performed a mid-season fitness test battery consisting of single leg countermovement, lateral and broad jump tests, two change of direction speed (CODS) tests, an 8 x 10 m repeated sprint test, and a 20 m sprint. The Kappa coefficient showed only ‘slight’ levels of agreement (K range = -0.05 to 0.15), indicating that asymmetries rarely favoured the same side during each of the jump tests. The single leg countermovement jump showed significantly (p = 0.006) larger asymmetries (11.2 ± 8.4) than the broad jump (6.4 ± 4.6) and significant correlations were present between jumping asymmetries and jump (r = -0.32 to -0.52), CODS (r = 0.31 to 0.32) and repeated sprint (r = 0.35 to 0.40) performance. The findings of the present study highlight the independent nature of jumping asymmetries and associations with measures of physical performance. Practitioners are encouraged to use multiple tests to detect existing side differences and consider appropriate training interventions for the reduction of inter-limb asymmetries

Positive correlational shift between crevicular antimicrobial peptide LL-37, pain and periodontal status following non-surgical periodontal therapy. A pilot study

Background: Periodontitis has a high prevalence and uncertain recurrence. Unlike the pro-inflammatory cytokine profile, little is known about the anti-inflammatory cytokine and antimicrobial peptide overview following treatment. The present study aimed to evaluate if any of the antimicrobial peptide LL-37, interleukin (IL) 4, 10 and 6 together with the volume of gingival crevicular fluid (GCF) and total protein concentration in GCF could be used as correlative biomarkers for the severity in periodontitis as well as prognostic factors in the management of the disease. Methods: Forty-five participants were recruited and allocated to the healthy (15), Stage I-II (15) or Stage III-IV periodontitis (15) group. Along with periodontal examination, GCF samples were obtained at baseline and 4–6 weeks following scaling and root planing (SRP) for the periodontitis groups. GCF samples were analyzed by ELISA kits to quantify LL-37 and IL-4, -6 and − 10. One-way ANOVA followed by Dunnett’s test was used to determine differences among the three groups at baseline. Two-way ANOVA followed by Sidak’s post-hoc test was used to compare between pre- and post-SRP in the two periodontitis groups. Results: The amount of GCF volume was significantly correlated to the severity of periodontitis and decreased following SRP, particularly in the Stage III-IV group (p < 0.01). The levels of LL-37, IL-6, and pain and periodontal clinical parameters were significantly correlated to the severity of periodontitis. IL-4 and IL-10 in the periodontitis groups were significantly lower than the healthy group (p < 0.0001) and barely improved following SRP up to the level of the healthy group. Conclusions: With the limitations of this study, crevicular LL-37 may be a candidate for a biomarker of periodontitis and the associated pain upon probing. Trial registration: The study was registered in clinical trials.gov, with number NCT04404335, dated 27/05/2020

Effects of 8-weeks of isoinertial vs. cable-resistance training on motor skills performance and interlimb asymmetries

Two training interventions conducted on youth handball athletes

Relationship between inter-limb asymmetries and speed and change of direction speed in youth handball players

The aims of the present study were to quantify inter-limb asymmetry from jumping, change of direction speed (CODS) and iso-inertial tests and to establish the association between those asymmetry scores and performance during speed and CODS tests in youth handball athletes. Twenty-six youth handball players (age: 16.2 0.9 years) volunteered to participate in this study and performed single leg countermovement jumps (SLCMJ), broad jumps (SLBJ), lateral jumps (SLLJ), CODS tests at 180º (CODS180) and 90º (CODS90), change of direction actions with iso-inertial overload (crossover step (CRO) and lateral shuffle step (LSS)) and 20 m sprint test. Excellent ICC values were found for all tests (ICC = 0.96-1.00) with the exception of the dominant limb during the CODS90 test (ICC = 0.69). Inter-limb asymmetry scores ranged from 3.66-12.67%. Iso-inertial asymmetry values were higher than those found during jumping tasks (9.8-12.7% vs. 3.66-8.76%). Spearman's r correlations showed significant relationships between CRO asymmetry and CODS90 performance on both limbs (r = 0.48-0.51; p < 0.05) and CODS180 (r = 0.41-0.51; p < 0.05) and sprint test (r = 0.46; p < 0.05). These results show the test-specific nature of asymmetries in youth handball players, with iso-inertial device and CODS deficit presenting the greatest magnitude of asymmetries. Furthermore, inter-limb differences during iso-inertial device (CRO) were associated with reduced CODS and sprint performance. These results suggest that the use of iso-inertial devices for the detection of inter-limb asymmetry may be more effective than total time during traditional CODS tests and that larger imbalances are associated with reduced athletic performance in youth handball players

Estabilidade de linguiça frescal elaborada com carne de caprinos de descarte sem adição de gordura sob armazenamento refrigerado.

Resumo: O presente trabalho objetivou avaliar a viabilidade de produção de linguiça frescal elaborada com carne caprina de animais de descarte, sem adição de gordura suína na formulação, e determinar a estabilidade química e microbiológica deste produto durante o armazenamento à temperatura de 5ºC. As amostras foram avaliadas após 0, 7, 14, 21, 28, 35 e 42 dias de armazenamento refrigerado quanto aos parâmetros de oxidação lipídica, pH e qualidade microbiológica. A composição centesimal foi analisada logo após a elaboração O produto apresentou umidade acima do limite máximo estabelecido pelo padrão de identidade e qualidade para linguiças. Não foram constatadas alterações significativas (p>0.05) com relação à oxidação lipídica nem com relação aos parâmetros microbiológicos avaliados. A utilização de carne caprina proveniente de animais de descarte na elaboração de linguiça frescal mostrou-se viável, resultando em um produto cárneo estável para os parâmetros analisados até 35 dias de armazenamento refrigerado. [Chemical and microbiological stability of fresh sausages without fat addition elaborated with meat from discarded goat and stored under refrigeration]. Abstract: The use of goat meat from discarded old animals in the manufacture of fresh sausages made without addition of pork fat was investigated to evaluate its chemical and microbiological stability under refrigeration storage at 5°C. Samples are analyzed at 0, 7, 14, 21, 28, 35 and 42 days of refrigeration storage in relation to microbiological, fat oxidation and pH parameters. The chemical composition was performes as soon as the sausages were produced. The product presented the level of moisture above the maximum limit settled by the legislation. The sausages were stable during the refrigeration storage in relation to lipid oxidation and microbiological growth. The use of goat meat from discarded animals showed to be a viable alternative, goat sausages present stability in relation to analyzed parameters until 28 days under refrigeration storage