- DELEGATION AND ENDOGENOUS MERGERS IN OLIGOPOLY

In this paper we consider the interactions between the use of strategic delegation and mergers in the context of a Cournot oligopoly with linear demand and cost functions. It is assumed that, after the merging process is completed, the owner of every independent firm decides its managerial incentive for his manager. In the context of endogenous mergers through acquisitions, we show that the incentive to merge, under delegation, is considerably increased with respect to the setting without delegation. In fact, we prove that the level of welfare in the setting with delgation is, in some cases, lower than the corresponding under non delegation.Strategic delegation, endoqenous mergers, cournot oligopoly

Global properties of the spectrum of the Haldane-Shastry spin chain

We derive an exact expression for the partition function of the su(m) Haldane-Shastry spin chain, which we use to study the density of levels and the distribution of the spacing between consecutive levels. Our computations show that when the number of sites N is large enough the level density is Gaussian to a very high degree of approximation. More surprisingly, we also find that the nearest-neighbor spacing distribution is not Poissonian, so that this model departs from the typical behavior for an integrable system. We show that the cumulative spacing distribution of the model can be well approximated by a simple functional law involving only three parameters.Comment: RevTeX 4, 7 pages, 4 figures. To appear in Phys. Rev.

Universidad de California San Diego versus Universidad Politécnica de Cataluña

Peer Reviewe

Mechanisms of Action and Targets of Nitric Oxide in the Oculomotor System

Nitric oxide (NO) production by neurons in the prepositus hypoglossi (PH) nucleus is necessary for the normal performance of eye movements in alert animals. In this study, the mechanism(s) of action of NO in the oculomotor system has been investigated. Spontaneous and vestibularly induced eye movements were recorded in alert cats before and after microinjections in the PH nucleus of drugs affecting the NO–cGMP pathway. The cellular sources and targets of NO were also studied by immunohistochemical detection of neuronal NO synthase (NOS) and NO-sensitive guanylyl cyclase, respectively. Injections of NOS inhibitors produced alterations of eye velocity, but not of eye position, for both spontaneous and vestibularly induced eye movements, suggesting that NO produced by PH neurons is involved in the processing of velocity signals but not in the eye position generation. The effect of neuronal NO is probably exerted on a rich cGMP-producing neuropil dorsal to the nitrergic somas in the PH nucleus. On the other hand, local injections of NO donors or 8-Br-cGMP produced alterations of eye velocity during both spontaneous eye movements and vestibulo-ocular reflex (VOR), as well as changes in eye position generation exclusively during spontaneous eye movements. The target of this additional effect of exogenous NO is probably a well defined group of NO-sensitive cGMP-producing neurons located between the PH and the medial vestibular nuclei. These cells could be involved in the generation of eye position signals during spontaneous eye movements but not during the VOR.Fondo de Investigación Sanitaria Grants 94/0388 and 97/2054Comunidad Autónoma de Madrid Grant 08.5/0019/1997Dirección General de Investigación Científica y Technológica Grant PB 93–117

Encuentros con... El Hematocrítico

En la conferencia a cargo de Miguel Ángel López, (@hematocritico) se traslada al alumnado la trayectoria en el ámbito de la Comunicación de este habitual de diversos medios online, con más de 100.000 seguidores en Twitter. Se explica cómo ha sido la trayectoria desde la creación de un modesto blog primigenio hasta llegar actualmente a diversas participaciones en el mundo de la Comunicación: se habla del programa 'Los hermanos Podcast', que llegó a encabezar la lista de podcast más oídos, de los tumblrs y blogs temáticos como Drama en el portal o El Hematocrítico de Arte, de los cuales se han editado libros recopilatorios. Se habla del trabajo como colaborador con su propia sección en revistas como Mongolia, Cuore y Ser Padres así como en televisión para Atresmedia (Top Chef, Liopardo). Se relatan las experiencias en las charlas TEDx y en otros foros de innovación en comunicación digital. Se aconseja al alumnado la constancia y ejercitar diariamente aquello a lo que se aspira (entradas diarias en blogs, en canales de Youtube, etc.) para poder presentar un conjunto de trabajos además de la formación que se acredite y para ir creando una rutina de trabajo que facilite hacerlo con mayor práctica.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effects of positive physical imagined contact in a spanish sample

Intergroup conflict has been present since the beginning of humankind. The fights for territories or power and the discrimination of the other seems a constant in our History. From several fields, it is have shown how the boundaries between groups and cultures and the competitive style of many of these relations set the basis for the emergence of conflict, being each day more obvious due to the Globalisation processes. For this reason, the reduction of prejudice and discrimination has been a main objective for the Intercultural Psychology, which, must create tools for this purpose. This work emphasise the usefulness of one of the most promising tools on this field, the imagined contact, grounded in Intergroup Contact Theory (Brown & Hewstone, 2005; Pettigrew, 1998). This technique allows the reduction of implicit negative attitudes toward outgroups using the imagination of individual interactions with members of an outgroup. In this experiment, it is tested a variant of this kind of contact, the physical imagined contact, as well as we try to demonstrate the existence of an improvement in prejudice reduction, at levels of implicit attitudes, when an imagined positive physical contact is given. The findings could not support statically our hypothesis. We discuss the implications of these results and the possibilities in the development of improvements for this useful tool.O conflito intergrupal tem estado presente desde o começo da civilização. As lutas por territórios ou poder e a discriminação dos outros são uma constante na nossa historia. Desde diversos campos tem sido demostrado como as fronteiras entre os grupos e culturas e o estilo competitivo de muitas de estas relações assentam as bases para o surgimento do conflito, sendo sus efeitos ainda mais óbvios devido aos processos de globalização. Por esta razão, a redução do preconceito e da discriminação tem sido um uma preocupação central para a Psicologia Intercultural, a qual, deve encarregar-se de criar ferramentas encaminhadas a este objetivo. Este trabalho remarca a utilidade de uma das técnicas mais promissoras de este campo, o contato imaginado, baseado na Teoria do Contato Intergrupal (Brown & Hewstone, 2005; Pettigrew, 1998). Esta técnica permite a redução das atitudes implícitas negativas faz aos exo-grupos, utilizando a imaginação de interações individuais com membros de outros grupos. Em este experimento é testada uma variante de este tipo de contato, o contato físico imaginado, assim como trata de demostrar a existência de uma melhora na redução do preconceito no nível das atitudes implícitas quando o contato físico imaginado é percebido como positivo. Os resultados não puderam suportar estatisticamente esta hipóteses. Discutimos estos resultados e as possibilidades no desenvolvimento de melhoras para esta útil ferramenta

Quasi-Exactly Solvable Spin 1/2 Schr\"odinger Operators

The algebraic structures underlying quasi-exact solvability for spin 1/2 Hamiltonians in one dimension are studied in detail. Necessary and sufficient conditions for a matrix second-order differential operator preserving a space of wave functions with polynomial components to be equivalent to a \sch\ operator are found. Systematic simplifications of these conditions are analyzed, and are then applied to the construction of several new examples of multi-parameter QES spin 1/2 Hamiltonians in one dimension.Comment: 32 pages, LaTeX2e using AMS-LaTeX packag

Quick Analysis of Organic Amendments via Portable X-ray Fluorescence Spectrometry

The determination of heavy metals in soils and organic amendments, such as compost, manure, biofertilizer, and sludge, generally involves the digestion of samples with aqua regia, and the determination of those in the solution using various techniques. Portable X-ray fluorescence (PXRF) has many advantages in relation to traditional analytical techniques. However, PXRF determines the total elemental content and, until now, its use for the analysis of organic amendments has been limited. The objective of this work is the calibration of a PXRF instrument to determine the aqua regia-soluble elemental contents directly in solid samples of organic amendments. Our proposal will avoid the digestion step and the use of other laboratory techniques. Using a training set of samples, calibration functions were obtained that allow the determination of the aqua regia-soluble contents from the PXRF readings of total contents. The calibration functions (obtained by multiple linear regression) allowed the quantitative determination of the aqua regia-soluble contents of Fe, K, P, S, Zn, Cu, Pb, Sr, Cr, and Mn, as well as the organic matter content and a semi-quantitative assessment of Al, Ca, V, Ba, Ni, and As contents. The readings of Si, Fe, Al, Ca, K, or S were used as correction factors, indicating that the calibrations functions found are truly based on the chemical composition of the sample matrix. This study will allow a fast, cheap, and reliable field analysis of organic amendments and of other biomass-based materials.Spanish Ministry of Science, Innovation and Universities, and the European Regional Development Fund, European Union, (AEI/FEDER, UE), grant number CGL2016-78937-R

On form-preserving transformations for the time-dependent Schr\"odinger equation

In this paper we point out a close connection between the Darboux transformation and the group of point transformations which preserve the form of the time-dependent Schr\"odinger equation (TDSE). In our main result, we prove that any pair of time-dependent real potentials related by a Darboux transformation for the TDSE may be transformed by a suitable point transformation into a pair of time-independent potentials related by a usual Darboux transformation for the stationary Schr\"odinger equation. Thus, any (real) potential solvable via a time-dependent Darboux transformation can alternatively be solved by applying an appropriate form-preserving transformation of the TDSE to a time-independent potential. The preeminent role of the latter type of transformations in the solution of the TDSE is illustrated with a family of quasi-exactly solvable time-dependent anharmonic potentials.Comment: LaTeX2e (with amsmath, amssymb, amscd, cite packages), 11 page