Search results for "problems"
showing 10 items of 620 documents
Falsas dietas y dietas falsas
2020
A nivel global, 1.900 millones de adultos tienen sobrepeso, de los que 650 millones presentan obesidad, con las consiguientes repercusiones sobre la salud y la economia. El tratamiento de la obesidad implica estrategias como la actividad fisica y la planificacion dietetica, siempre y cuando sean realizadas por profesionales sanitarios. En las ultimas decadas han aparecido dietas milagrosas, que tienen su origen a principios del siglo XX, y que pueden acarrear problemas de salud sobre sus usuarios. Una manera practica de detectarlas es que prometen perdidas rapidas de peso (mas de 1 kg por semana), aseguran que se realizan sin esfuerzo, tienen restricciones excesivas de energia y excluyen de…
Health Effects on Children’s Willingness to Compete
2011
The formation of human capital is important for a society's welfare and economic success. Recent literature shows that child health can provide an important explanation for disparities in children’s human capital development across different socio-economic groups. While this literature focuses on cognitive skills as determinants of human capital, it neglects non-cognitive skills. We analyze data from economic experiments with preschoolers and their mothers to investigate whether child health can explain developmental gaps in children’s non-cognitive skills. Our measure for children’s noncognitive skills is their willingness to compete with others. Our findings suggest that health problems a…
Monotonicity and local uniqueness for the Helmholtz equation
2017
This work extends monotonicity-based methods in inverse problems to the case of the Helmholtz (or stationary Schr\"odinger) equation $(\Delta + k^2 q) u = 0$ in a bounded domain for fixed non-resonance frequency $k>0$ and real-valued scattering coefficient function $q$. We show a monotonicity relation between the scattering coefficient $q$ and the local Neumann-Dirichlet operator that holds up to finitely many eigenvalues. Combining this with the method of localized potentials, or Runge approximation, adapted to the case where finitely many constraints are present, we derive a constructive monotonicity-based characterization of scatterers from partial boundary data. We also obtain the local…
Dimension bounds in monotonicity methods for the Helmholtz equation
2019
The article [B. Harrach, V. Pohjola, and M. Salo, Anal. PDE] established a monotonicity inequality for the Helmholtz equation and presented applications to shape detection and local uniqueness in inverse boundary problems. The monotonicity inequality states that if two scattering coefficients satisfy $q_1 \leq q_2$, then the corresponding Neumann-to-Dirichlet operators satisfy $\Lambda(q_1) \leq \Lambda(q_2)$ up to a finite-dimensional subspace. Here we improve the bounds for the dimension of this space. In particular, if $q_1$ and $q_2$ have the same number of positive Neumann eigenvalues, then the finite-dimensional space is trivial. peerReviewed
Stability of radial symmetry for a Monge-Ampère overdetermined problem
2008
Recently the symmetry of solutions to overdetermined problems has been established for the class of Hessian operators, including the Monge-Ampère operator. In this paper we prove that the radial symmetry of the domain and of the solution to an overdetermined Dirichlet problem for the Monge-Ampère equation is stable under suitable perturbations of the data. © 2008 Fondazione Annali di Matematica Pura ed Applicata and Springer-Verlag.
The use of history in mathematics education: The case of posthumous twins
2018
Se presenta un estudio exploratorio sobre un tipo particular de problemas verbales descriptivos de larga tradición e importancia en el desarrollo del pensamiento matemático: el problema de los gemelos póstumos. La metodología que sustenta el estudio tiene dos vertientes complementarias: el análisis histórico epistemológico y el análisis didáctico en los libros de texto y manuales escolares. Con énfasis en la resolución de problemas, se resalta la importancia de integrar la historia y epistemología de las ideas matemáticas en la investigación educativa, para provecho de estudiantes y profesores. An exploratory study is presented on a particular type of descriptive word problems of long tradi…
Credit and financial markets in the Iberian Peninsula at the end of the Middle Ages. Historiographic production and recent developments
2021
El artículo examina la trayectoria de los estudios sobre el crédito y los mercados financieros en la Península Ibérica a finales de la Edad Media, desde los primeros trabajos sobre la usura y el préstamo a interés, fundamentalmente judío, en la primera mitad del siglo XX, hasta las líneas de investigación más recientes, que se ramifican en diversas direcciones, desde el marco teórico, doctrinal y legal del mercado del crédito y el estudio de los diferentes instrumentos financieros –préstamo a interés, crédito comercial y bancario, crédito a largo plazo en forma de censales y censos consignativos– a la deuda pública y el crédito privado, especialmente el crédito rural. Todos estos estudios m…
The Role of doctors in the slave trade during the fourteenth and fifteenth centuries within the Kingdom of Valencia (Crown of Aragon)
2013
Slavery had become increasingly widespread throughout the entire Mediterranean region during the late Middle Ages. At the same time, a new form of medicine (based upon the Galenism to which the universities gave voice), together with the practice thereof and its practitioners, had gained ground. Detailed evidence from the Kingdom of Valencia enables us to study these two topics, namely slavery and the new medicine. This article illustrates how doctors came to play a highly active role in the slave trade through the assistance they provided in preventing and rectifying any instances of fraud therein.
Los intelectuales y el “espacio de opinión” mediático: el caso de La desfachatez intelectual
2020
espanolEste articulo analiza la controversia provocada por la publicacion del libro La Desfachatez intelectual (2016) de Ignacio Sanchez Cuenca, dentro del “espacio de opinion” espanol. Se observara la evolucion historica y organizacion interna del espacio de opinion, los recursos sociales de algunos actores destacados, asi como los generos intelectuales utilizados y defendidos por sus protagonistas. En este contexto, La desfachatez intelectual pretende transformar las reglas de juego del espacio y, al mismo tiempo, redefinir el equilibrio de poderes entre los diferentes campos sociales que lo conforman. EnglishThis article analyses the controversy generated after the publication of Ignacio…