Joan Robinson Was Almost Right: Output under Third-Degree Price Discrimination

In this paper, we show that in order for third-degree price discrimination to increase total output, the demands of the strong markets should be, as conjectured by Robinson (1933), more concave than the demands of the weak markets. By making the distinction between adjusted concavity of the inverse demand and adjusted concavity of the direct demand, we are able to state necessary conditions and sufficient conditions for third-degree price discrimination to increase total output.

Uptake and intracytoplasmic storage of pigmented particles by human CD34+stromal cells/telocytes: endocytic property of telocytes

We studied the phagocytic-like capacity of human CD34+ stromal cells/telocytes (TCs). For this, we examined segments of the colon after injection of India ink to help surgeons localize lesions identified at endoscopy. Our results demonstrate that CD34+ TCs have endocytic properties (phagocytic-like TCs: phTCs), with the capacity to uptake and store India ink particles. phTCs conserve the characteristics of TCs (long, thin, bipolar or multipolar, moniliform cytoplasmic processes/telopodes, with linear distribution of the pigment) and maintain their typical distribution. Likewise, they are easily distinguished from pigment-loaded macrophages (CD68+ macrophages, with oval morphology and coarse granules of pigment clustered in their cytoplasm). A few c-kit/CD117+ interstitial cells of Cajal also incorporate pigment and may conserve the phagocytic-like property of their probable TC precursors. CD34+ stromal cells in other locations (skin and periodontal tissues) also have the phagocytic-like capacity to uptake and store pigments (hemosiderin, some components of dental amalgam and melanin). This suggests a function of TCs in general, which may be related to the transfer of macromolecules in these cells. Our ultrastructural observation of melanin-storing stromal cells with characteristics of TCs (telopodes with dichotomous branching pattern) favours this possibility. In conclusion, intestinal TCs have a phagocytic-like property, a function that may be generalized to TCs in other locations. This function (the ability to internalize small particles), together with the capacity of these cells to release extracellular vesicles with macromolecules, could close the cellular bidirectional cooperative circle of informative exchange and intercellular interactions.

Coincidence point theorems in quasi-metric spaces without assuming the mixed monotone property and consequences in G-metric spaces

In this paper, we present some coincidence point theorems in the setting of quasi-metric spaces that can be applied to operators which not necessarily have the mixed monotone property. As a consequence, we particularize our results to the field of metric spaces, partially ordered metric spaces and G-metric spaces, obtaining some very recent results. Finally, we show how to use our main theorems to obtain coupled, tripled, quadrupled and multidimensional coincidence point results.

El ADPIC y la corrupción de la industria farmacéutica: el acceso a los medicamentos en los países del Norte y del Sur

Resumen (Castellano): El acceso a los medicamentos ha sido en las últimas décadas un tema a debatir tanto en los países del Sur como en los países del Norte. Los precios impuestos por la industria farmacéutica para enfermedades tan graves como el VIH-SIDA han sido excesivos y consecuentemente inalcanzables para los países más pobres. Sin embargo, actualmente los países más ricos del Norte están sufriendo estas mismas consecuencias a causa del nuevo tratamiento contra la hepatitis C, cuyos precios astronómicos han excluido a numerosos enfermos del acceso al mismo. El derecho humano a la salud está siendo vulnerado, y las principales responsables son las empresas farmacéuticas, las cuales han corrompido los sistemas de salud. La fijación de precios monopólicos, tras el fortalecimiento de las patentes farmacéuticas con la firma del Acuerdo sobre Derechos de Propiedad Intelectual relacionados con el Comercio (ADPIC), ha constituido un obstáculo para la realización del mismo, agrandado por las disposiciones ADPIC-plus incluidas en los tratados de libre comercio . No obstante, la consolidación de la industria de medicamentos genéricos ha logrado competir contra ellas, suministrando medicamentos asequibles y promoviendo los intereses de los más necesitados.

Approximate Solutions by Truncated Taylor Series Expansions of Nonlinear Differential Equations and Related Shadowing Property with Applications

This paper investigates the errors of the solutions as well as the shadowing property of a class of nonlinear differential equations which possess unique solutions on a certain interval for any admissible initial condition. The class of differential equations is assumed to be approximated by well-posed truncated Taylor series expansions up to a certain order obtained about certain, in general nonperiodic, sampling points t(i) is an element of [t(0), t(J)] for i = 0, 1, . . . , J of the solution. Two examples are provided.