Constructing solutions for a kinetic model of angiogenesis in annular domains

We prove existence and stability of solutions for a model of angiogenesis set in an annular region. Branching, anastomosis and extension of blood vessel tips are described by an integrodifferential kinetic equation of Fokker-Planck type supplemented with nonlocal boundary conditions and coupled to a diffusion problem with Neumann boundary conditions through the force field created by the tumor induced angiogenic factor and the flux of vessel tips. Our technique exploits balance equations, estimates of velocity decay and compactness results for kinetic operators, combined with gradient estimates of heat kernels for Neumann problems in non convex domains.Comment: to appear in Applied Mathematical Modellin

Economic Development, Institutional Quality and Regional integration: Evidence from Africa Countries.

The aim of this paper is to provide new empirical evidence about the determinants of per capita income in African countries, with particular attention to the affects of governance institutional quality and sub regional integration on income level. We use a sample of 49 countries from the period 1996-2004 and the Generalized Method of Moments Estimation model for dynamic panel, proposed by Arellano and Bond (1991). The results show that African regional groups with better institutions, higher degrees of regional integration cooperation, higher rates of investment in human capital and lower rates of population growth, show a higher level of per capita incomeSub-Regional Integration, Institutional Quality, Economic development

Participatory Building of a Decision Support System for Adaptive Water Management in the Upper Guadiana Basin

Water management has evolved in the last years towards more integrated and participatory approaches, aiming at improving the adaptability of water systems. Following this line, we propose a methodology to build a decision support system, based on the participation of stakeholders and the integration of the different disciplines involved in water use, as well as the inclusion of uncertainties in the management planning. The process has been implemented in the Upper Guadiana basin (Spain) with the aim of solving the existing conflicts: the aquifer, which is the main water source in the area, has been over-exploited during the last decades for irrigation. This has lead to serious degradation of natural water-related ecosystems and important social conflicts. The river basin authority has tried to implement different policies to attain the aquifer recovery, so far without much success. At present, a new management plan specifically for the Upper Guadiana has been approved, where some policy measures are proposed for attaining the reduction of agricultural water consumption. The methodology proposed in this work is based on the combination of a Bayesian network and an economic mathematical programming model, elaborated with the active participation of stakeholders. The resulting DSS will be used to evaluate different management options, within those included in the Special Plan of the Upper Guadiana, in terms of their impacts on the agricultural income and the environmental sustainability. Results show that new measures would not be successful unless they are accompanied by an increase of compliance of farmers with water regulations.Decision support system, Bayesian networks, economic model, Resource /Energy Economics and Policy,

Motivation to learn Chemistry in massive open online courses

One of the key factors for any educational proposal to achieve success lies in the motivation of students. The disposition that the students have before the learning is fundamental to be able to obtain the objectives. MOOC (Massive Open Online Course) has emerged strongly in the context of university education. The use of MOOC offers time in the classroom that can be used to do active learning activities in which teachers' role is essential, and students can review learning materials at their own pace. The objective of this paper was to evaluate a course about concepts. The use of a MOOC named Introduction to Chemistry: Reactions. It is a course for students with limited background in chemistry; basic concepts involved in chemical reactions, stoichiometry, the periodic table, periodic trends, nomenclature. The evaluation of the proposal was made by students of Electrical Engineers at University of Malaga, with satisfactory results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

How to teach chemistry? Is Chemistry a new universal language

Chemistry has been developed greatly throughout the 20th century. Chemistry is included in the curriculum of elementary and secondary education. In general, students are not interested in science, and because of this ,students tend not to make an effort to learn and understand the meaning of concepts and the chemistry language that are being taught to them. If we consider that there is a little bit analogy between chemistry and foreign languages, we should learn the sym bols of the Periodic Table as symbols of an alphabet. The first knowledge that one needs to know when we are learning a second language is the new symbols of our new alphabet. It is necessary to learn more than 103 symbols, the chemical alphabet. After that, the students are ready to begin the formation of chemical words. In this case, learning the compounds names is easier when only two elements are involved, but when there are more than two, the chemical language is more complex. The proposal of this study is intended to design and implement a teaching strategy for teaching and learning the chemical language, first of all the chemical alphabet, the Periodic Table and then, the language which it is built the chemistry. For this proposal, we will use some m ultimedia application (Information and Communication Technologies (ITC)), which consists in an interactive periodic table. Students will be able to push one element and they will be able to see the properties of this element and which other element will be able to combine with it, and furthermore, if this element will be able to combine with itself. When they know properly the simple language, they will be able to continue studying more complex words, in this case, the reactions. With this multimedia application, the students will be able to watch how the atoms will change, one atom changes to a new atom during a whole reaction. And finally, they will be able to watch how these new atoms have new properties, and they combine each one. With this Periodic Table, the students learn chemical formulas and equations. 2. Experimental. This study was created as a descriptive study in which the survey technique was used. The study was carried out during the course 2013 /14. The sample consisted of 35 volunteer studen ts from two different classes, at the first course of Mechanical Engineer degree at University of Málaga. But the vast majority of them were there, they did not love chemistry. Each student made one questionnaire about the utility of our multimedia application. The scale of the test was a five point Likert type scale with a range of five options. The positive items range from 1= Certainly Agree to 5 = Certainly Disagree. 3. Results and Discussion. Mostly the average of these statements showed an overall positive response statements .The majority of the each student average of the response statements shown are positive, more than 2.5. After this study, we studied if there was some difference between the two groups studied and it can be seen that the mean an d the standard deviation for the different variables according to the two investigated groups demonstrated that there was no significant difference in the level of interest or utility that they give to the multimedia application. 4. Conclusions. The results of this study are based on a survey purpose after the use of an interactive application in order to improve the learning process of the chemistry language. This information is valuable since students could watch these animations on a computer. This is based on the cognitive theory of multimedia learning, which assumes that learners process information through a dual coding capability involving a auditory/verbal channel and a visual/pictorial channel. Nevertheless, the vast majority of students recognize that chemistry knowledge is useful to interpret aspect of their everyday life, but not many of them express their wish to continue chemistry studies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Publishing performance in economics: Spanish rankings (1990-1999)

This paper contributes to the growing literature that analyses the Spanish publishing performance in Economics throughout the 1990s. Several bibliometric indicators are used in order to provide Spanish rankings (of both institutions and individual authors) based on Econlit journals. Further, lists of the ten most influential authors and articles over that period, in terms of citations, are reported.Publicad

Well posedness of an angiogenesis related integrodifferential diffusion model

We prove existence and uniqueness of nonnegative solutions for a nonlocal in time integrodifferential diffusion system related to angiogenesis descriptions. Fundamental solutions of appropriately chosen parabolic operators with bounded coefficients allow us to generate sequences of approximate solutions. Comparison principles and integral equations provide uniform bounds ensuring some convergence properties for iterative schemes and providing stability bounds. Uniqueness follows from chained integral inequalities

Simple relationship between the virial-route hypernetted-chain and the compressibility-route Percus--Yevick values of the fourth virial coefficient

As is well known, approximate integral equations for liquids, such as the hypernetted chain (HNC) and Percus--Yevick (PY) theories, are in general thermodynamically inconsistent in the sense that the macroscopic properties obtained from the spatial correlation functions depend on the route followed. In particular, the values of the fourth virial coefficient $B_4$ predicted by the HNC and PY approximations via the virial route differ from those obtained via the compressibility route. Despite this, it is shown in this paper that the value of $B_4$ obtained from the virial route in the HNC theory is exactly three halves the value obtained from the compressibility route in the PY theory, irrespective of the interaction potential (whether isotropic or not), the number of components, and the dimensionality of the system. This simple relationship is confirmed in one-component systems by analytical results for the one-dimensional penetrable-square-well model and the three-dimensional penetrable-sphere model, as well as by numerical results for the one-dimensional Lennard--Jones model, the one-dimensional Gaussian core model, and the three-dimensional square-well model.Comment: 8 pages; 4 figures; v2: slight change of title; proof extended to multicomponent fluid