1,241 research outputs found

    Limiting problems for a nonstandard viscous Cahn--Hilliard system with dynamic boundary conditions

    Get PDF
    This note is concerned with a nonlinear diffusion problem of phase-field type, consisting of a parabolic system of two partial differential equations, complemented by boundary and initial conditions. The system arises from a model of two-species phase segregation on an atomic lattice and was introduced by Podio-Guidugli in Ric. Mat. 55 (2006), pp.105--118. The two unknowns are the phase parameter and the chemical potential. In contrast to previous investigations about this PDE system, we consider here a dynamic boundary condition for the phase variable that involves the Laplace-Beltrami operator and models an additional nonconserving phase transition occurring on the surface of the domain. We are interested to some asymptotic analysis and first discuss the asymptotic limit of the system as the viscosity coefficient of the order parameter equation tends to 0: the convergence of solutions to the corresponding solutions for the limit problem is proven. Then, we study the long-time behavior of the system for both problems, with positive or zero viscosity coefficient, and characterize the omega-limit set in both cases

    Validation of the Italian version of the Revised Prenatal Coping Inventory (NuPCI) and its correlations with pregnancy-specific stress

    Get PDF
    Background: Pregnancy is a period of happiness but also of physical and psychological changes that can lead to distress. Functional coping strategies can reduce the pregnancy specific-stress. This study aimed to assess the psychometric properties of the Revised Prenatal Coping Inventory (NuPCI) in an Italian sample and to investigate how coping strategies were associated with pregnancy-specific stress. Methods: In this cross-sectional study, low-risk pregnant women (N = 211) were assessed with NuPCI, NuPDQ (Revised-Prenatal Distress Questionnaire), Brief-COPE (Coping Orientation to the Problems Experienced), and STAI (State-Trait Anxiety Inventory). The reliability of NuPCI was evaluated by assessing its internal consistency and factor structure (with a Confirmatory Factor Analysis, CFA). The concurrent validity between NuPCI and Brief-COPE and NuPDQ and STAI was investigated. Lastly, the relationship between NuPCI and NuPDQ was analyzed, as well as the ability of these scales to predict Apgar score at birth. Results: Internal consistency of NuPCI scales was good for Planning-Preparation (\u251C=0.84) and Spiritual-Positive Coping (\u251C=0.81) scales, acceptable for Avoidance (\u251C=0.76) scale. Moreover, the original three-factor structure was confirmed using a CFA with 29 of the 32 items (\u3c72374 = 618.06; RMSEA = 0.056, 95% confidence interval: [0.048, 0.063]); CFI = 0.920; and TLI = 0.913). Statistically significant correlations between NuPCI scales and Brief-COPE subscales ranged between r = + 0.217 and r = + 0.624; also, NuPDQ score was positively correlated with STAI scales (State scale: r = + 0.539; Trait scale: r = + 0.462). Concurrent validity was confirmed reporting that NuPDQ score was predicted by NuPCI scores (R2 = 0.423, p < 0.001), positively by Avoidance (\u3b2=+0.572) and Planning-Preparation (\u3b2=+0.215) and negatively by Spiritual-Positive Coping (\u3b2=-0.132). Finally, considering the stress, the effect of the Avoidance and Spiritual-Positive Coping scores respectively in decreasing (+ 155%) and increasing (+ 16%) the Apgar score became stronger. Conclusions: Italian NuPCI has sound psychometric properties and it is a useful coping measure. NuPDQ showed also a good validity. Our results may suggest a significant role for coping strategies, particularly in modulating the condition of the newborn at birth

    Optimal Surface Drainage Inlets Positioning Using Stochastic Pluvial Flooding Analysis

    Get PDF
    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Mitochondrial DNA diversity of five Italian autochtonous donkey breeds

    Get PDF
    AbstractTo investigate the mitochondrial DNA diversity of five Italian donkey breeds (Amiata, Martinafranca, Romagnolo, Asinara, and Ragusano), we sequenced the HVR I region (D-loop, 288 bp) and cytochrome b gene (274 bp) in 121 individuals. In the D-loop we found nineteen mutations corresponding to fourteen different haplotypes, while in cyt b coding gene only six mutations were found, originating five different haplotypes. In particular, three mutations out of six were non-synonymous, causing an aminoacidic substitution. About the D-loop region, the value of nucleotide diversity (π) observed within breeds was relatively low, but not far from values detected in other European breeds. Phylogenetic and network analyses disclosed the presence of two divergent maternal lineages within Italian donkeys. These haplogroups correspond to the well known lineages of ancestors (Equus asinus somaliensis and E. a. africanus), as donkeys were domesticated from distinct wild subspecies living in Eastern Africa regions. ..

    On a diffuse interface model for tumour growth with non-local interactions and degenerate mobilities

    Get PDF
    We study a non-local variant of a diffuse interface model proposed by Hawkins--Darrud et al. (2012) for tumour growth in the presence of a chemical species acting as nutrient. The system consists of a Cahn--Hilliard equation coupled to a reaction-diffusion equation. For non-degenerate mobilities and smooth potentials, we derive well-posedness results, which are the non-local analogue of those obtained in Frigeri et al. (European J. Appl. Math. 2015). Furthermore, we establish existence of weak solutions for the case of degenerate mobilities and singular potentials, which serves to confine the order parameter to its physically relevant interval. Due to the non-local nature of the equations, under additional assumptions continuous dependence on initial data can also be shown.Comment: 28 page

    Genetic differentiation of draa indigenous breed and relationships with other goat populations assessed by microsatellite DNA markers

    Get PDF
    Moroccan goats are characterized by the presence of different populations identified only based on their phenotypes. The objectives of this study were to assess the genetic differentiation of the Draa goat breed and to analyze its genetic structure and its relationships with other local populations using 12 microsatellite markers. The screening was done in South Eastern and Southern Morocco on 192 animals form 5 popula-tions, including Draa, Atlas, Barcha, Ghazzalia breeds, and from a set of goats showing highly variable phenotypes grouped together into "undefined goats" population. Population structure was assessed by stan-dard diversity indices, multivariate statistics, analysis of molecular variance and bayesian clustering tech-niques. The mean allelic richness was 6.526, varying from 2.777 to 9.669. More than 88.4% of the total variance was distributed between individuals and only 1.85% was due to differences between populations. The Draa breed had the lowest observed heterozygosity (0.579), the highest inbreeding coefficient (0.161) and a higher number of deviations from Hardy-Weinberg equilibrium. Moreover, it had the highest genetic distances from the other populations. Bayesian clustering showed a high level of admixture between popu-lations, with a single well defined cluster identifiable within Draa breed. It was concluded that the studied Moroccan goat populations have a substantial but weakly structured genetic diversity, with the exception of Draa breed which shows a higher degree of differentiation and population substructure
    corecore