Search Results (9)

This work presents a solving method for problems of Ambrosetti-Prodi type involving p-Laplacian and p-pseudo-Laplacian operators by using adequate variational methods. A variant of the mountain pass theorem, together with a kind of Palais-Smale condition, is involved in order to obtain and characterize solutions for some mathematical physics issues. Applications of these results for solving some physical chemical problems evolved from the need to model real phenomena are displayed. Solutions for Dirichlet problems containing these two operators applied for modeling critical micellar concentration, as well as the volume fraction of liquid mixtures, have been drawn. Full article

This paper aims to identify the export competitiveness of agri-food products at the level of the European Union Member States, considering indicators/elements belonging to technical innovation (technical complexity) as well as qualitative elements. The main research problem is to examine the differences in the technical complexity of agri-food exports (EXPY) between EU Member States. Through detailed analysis of product categories and Member States’ performance, we have identified significant differences in the technical complexity of exports. Products such as dairy, meat, cereal and vegetable preparations were associated with high technical complexity, while fruit, tobacco and oils were classified in the low technical complexity category. We also identified Member States with exports characterised by high technical complexity, including Cyprus, Ireland and Luxembourg, and those with low technical complexity, such as Slovakia, Latvia and Croatia. These findings suggest the influence of various factors, such as economic specialisation, natural resources and R&D investment on shaping the agri-food export landscape in the European Union. In-depth analysis of these issues provides significant insights for understanding the economic and technical dynamics in the European agri-food sector. Full article

Macromolecular assemblies, such as protein complexes, undergo continuous structural dynamics, including global reconfigurations critical for their function. Two fast analytical methods are widely used to study these global dynamics, namely elastic network model normal mode analysis and principal component analysis of ensembles of structures. These approaches have found wide use in various computational studies, driving the development of complex pipelines in several software packages. One common theme has been conformational sampling through hybrid simulations incorporating all-atom molecular dynamics and global modes of motion. However, wide functionality is only available for experienced programmers with limited capabilities for other users. We have, therefore, integrated one popular and extensively developed software for such analyses, the ProDy Python application programming interface, into the Scipion workflow engine. This enables a wider range of users to access a complete range of macromolecular dynamics pipelines beyond the core functionalities available in its command-line applications and the normal mode wizard in VMD. The new protocols and pipelines can be further expanded and integrated into larger workflows, together with other software packages for cryo-electron microscopy image analysis and molecular simulations. We present the resulting plugin, Scipion-EM-ProDy, in detail, highlighting the rich functionality made available by its development. Full article

This paper deals with two types of systems of second-order differential equations with parameters: coupled systems with the boundary conditions of the Sturm–Liouville type and classical systems with Dirichlet boundary conditions. We discuss an Ambosetti–Prodi alternative for each system. For the first type of system, we present sufficient conditions for the existence and non-existence of its solutions, and for the second type of system, we present sufficient conditions for the existence and non-existence of a multiplicity of its solutions. Our arguments apply the lower and upper solutions method together with the properties of the Leary–Schauder topological degree theory. To the best of our knowledge, the present study is the first time that the Ambrosetti–Prodi alternative has been obtained for such systems with different parameters. Full article

A lifelong strict gluten-free diet is the only available treatment for patients with coeliac disease (CD). As with any restrictive diet, it may potentially lead to nutritional deficits. Seventy-six patients with CD (mean age 9.0 ± 4.3 years, 57% female) and 590 healthy controls (HC) (mean age 9.9 ± 0.1 years, 54% female) were recruited and requested to keep a 3-day food record (3DFR). In HC patients, anthropometric data were determined at the time when 3DFRs were collected. In CD patients, anthropometric data were determined at two time points: at diagnosis and at the time of 3DFRs collection. Intake of energy, macronutrients, and micronutrients was determined using PRODI expert 6.9 software and expressed as a percentage of recommended daily intake. In CD patients, all measured anthropometric measures (body weight (BW), body height (BH), and body mass index (BMI) z-scores) increased significantly after the mean duration of 34.1 months of a GFD. Overall, CD patients had significantly lower BW and BH z-scores compared to healthy controls. Patients with CD were generally more compliant with the recommended dietary intakes of macronutrients and some micronutrients, as compared to HC. Three participants were not compliant with the GFD; 42.1% of participants took oral nutritional supplements at the start of their GFD. Our study showed that patients with CD have better compliance with dietary recommendations compared to healthy controls, showing that a well-balanced GFD diet can provide necessary macro- and micronutrients. Full article

Accurate dietary analysis of energy, nutrient intake, and meal timing in human studies using traditional dietary assessment methods (e.g., food records) is challenging and time-consuming. The widespread use of smartphones, tablets, and nutrition applications (apps) can overcome some of these problems. The objective of this study was to evaluate the validity of an FDDB smartphone app and food database compared with PRODI^®—a professional platform for nutritional counselling using the German Nutrient Database. Dietary records were collected from 10 subjects participating in the crossover intermittent fasting trial for 2 weeks at baseline and during the eating timeframe of 8 h (early or late in the course of the day). The FDDB app and database enabled a quicker and less sophisticated analysis of food composition and timing than the PRODI^® software. Good agreement between the methods was found for energy and macronutrient intakes, while the FDDB data on most micronutrients and saturated/unsaturated fat intake were unreliable. In contrast to PRODI^®, FDDB provided effective assessment of timely compliance, making it a promising tool for chrononutritional studies. Thus, the FDDB app is comparable to the traditional PRODI^® dietary assessment method, and can be effectively used in human dietary trials and medical practice for specific goals. Full article

This paper presents sufficient conditions for the existence of a bifurcation point for nonlinear periodic third-order fully differential equations. In short, the main discussion on the parameter s about the existence, non-existence, or the multiplicity of solutions, states that there are some critical numbers ${\sigma }_0$ and ${\sigma }_1$ such that the problem has no solution, at least one or at least two solutions if $s<{\sigma }_0$, $s={\sigma }_0$ or ${\sigma }_0>s>{\sigma }_1,$ respectively, or with reversed inequalities. The main tool is the different speed of variation between the variables, together with a new type of (strict) lower and upper solutions, not necessarily ordered. The arguments are based in the Leray–Schauder’s topological degree theory. An example suggests a technique to estimate for the critical values ${\sigma }_0$ and ${\sigma }_1$ of the parameter. Full article

Micropolar fluids are fluids with microstructure and belong to a class of fluids with asymmetric stress tensor that called Polar fluids, and include, as a special case, the well-established Navier–Stokes model. In this work we study a 3D micropolar fluids model with Navier boundary conditions without friction for the velocity field and homogeneous Dirichlet boundary conditions for the angular velocity. Using the Galerkin method, we prove the existence of weak solutions and establish a Prodi–Serrin regularity type result which allow us to obtain global-in-time strong solutions at finite time. Full article

Among several developments, the field of Economic Complexity (EC) has notably seen the introduction of two new techniques. One is the Bootstrapped Selective Predictability Scheme (SPSb), which can provide quantitative forecasts of the Gross Domestic Product of countries. The other, Hidden Markov Model (HMM) regularisation, denoises the datasets typically employed in the literature. We contribute to EC along three different directions. First, we prove the convergence of the SPSb algorithm to a well-known statistical learning technique known as Nadaraya-Watson Kernel regression. The latter has significantly lower time complexity, produces deterministic results, and it is interchangeable with SPSb for the purpose of making predictions. Second, we study the effects of HMM regularization on the Product Complexity and logPRODY metrics, for which a model of time evolution has been recently proposed. We find confirmation for the original interpretation of the logPRODY model as describing the change in the global market structure of products with new insights allowing a new interpretation of the Complexity measure, for which we propose a modification. Third, we explore new effects of regularisation on the data. We find that it reduces noise, and observe for the first time that it increases nestedness in the export network adjacency matrix. Full article