Caracterización de la cadena de comercialización de la langosta (Jasus Frontalis) del Archipiélago Juan Fernández

La economía del Archipiélago Juan Fernández, se sustenta principalmente por la extracción y comercialización de las langostas vivas y, en menor medida, por la venta de otras especies. Los pescadores de la zona, en forma individual o en varias agrupaciones, venden a empresas intermediarias establecidas en las islas Robinson Crusoe y Alejandro Selkirk, o bien, se comprometen a entregar el recurso en forma exclusiva a algún comprador, mediante convenios informales.La presente investigación, describe la estructura comercial de la langosta (Jasus Frontalis), del archipiélago de Juan Fernández, describiendo todos los integrantes de su cadena comercial, de la cual no habían precedentes, se estiman los costos y márgenes de comercialización, para cada eslabón, y finalmente se realiza un análisis de costos de los pescadores, otorgando antecedentes que permitan generar estrategias de corto, mediano y largo plazo, con el fin de lograr, una comercialización más eficiente, para el primer eslabón de la cadena.Esta investigación es un estudio de tipo exploratorio, realizado entre los años 2007 y 2008., cuyos resultados permiten conocer los principales actores que participan en la cadena de comercialización de las langostas, estos son: Pescadores, Intermediarios en la Isla y del Continente. Se determinó que, los pescadores obtienen un 37,9% de retorno sobre sus ventas, por lo que son el eslabón más rentable en relación a los costos. Sin embargo el margen de comercialización indica que los pescadores ganan el 18,7 % del precio final.  

Nuevas técnicas de investigación basadas en la observación de la respuesta emocional de los consumidores. Análisis del servicio de despacho a domicilio de alimento de mascotas

Debido a la dudas respecto de posibles diferencias entre lo que declaran consumidores que participan en estudios de mercado y lo que realmente sienten, se realizó un estudio para evaluar el uso de nuevas técnicas de investigación de conducta de los consumidores, aplicada a la percepción de los participantes respecto de un estímulo de marketing, consistente en el logotipo de una empresa de servicios de despacho a domicilio de alimento para mascotas. La técnica evaluada consistió en la observación no obstructiva de la respuesta emocional de consumidores durante la evaluación dicho logotipo, medida en términos de la emoción predominante y la valencia de dicha emoción. El estudio se organizó en tres etapas, en la primera se realizaron cuatro sesiones de Grupo Focales con un total de 32 participantes, organizados en categorías de acuerdo a su edad y Grupo Socioeconómico. Las etapas dos y tres consistieron en una serie de entrevistas individuales, a un grupo de cinco y seis mujeres respectivamente. Los resultados del trabajo sugieren que el uso de la medición y análisis de la respuesta emocional de las personas, provee de información de utilidad, complementaria a la generada por técnicas tradicionales de investigación, contribuyendo de ese modo con información que permite generar estímulos de marketing más coherentes para los consumidores

A Complexity Architecture for Information Technologies: a Three-Year Didactic Experiment

One medium-term strategy for helping in the management of complexity is the introduction of a conceptual complexity component in the very centre of university curricula. In very few areas is the growth of complexity as evident as in the information technologies (ITs), the focus of the work presented in the current paper. We have therefore developed an integrated way of tackling the specific field of information technologies by means of an approach,to complexity. The content of this paper describes the guidelines of our research effort, placing an emphasis on informatics. Concepts of complexity based on the system metaphor have been substantially drawn upon in this exercise and are thus presented in some detail. Also described is a didactic experiment conducted by the author and designed to provide a new and integrating approach to University curricula for future professionals. The students' "discovery" of complexity is the focal point of the experiment. The findings of this effort are encouraging and call for the continuation and expansion of this experiment

Chameleonic Generalized Brans--Dicke model and late-time acceleration

In this paper we consider Chameleonic Generalized Brans--Dicke Cosmology in the framework of FRW universes. The bouncing solution and phantom crossing is investigated for the model. Two independent cosmological tests: Cosmological Redshift Drift (CRD) and distance modulus are applied to test the model with the observation.Comment: 20 pages, 15 figures, to be published in Astrophys. Space Sci. (2011

Mice Lacking Thyroid Hormone Receptor β Show Enhanced Apoptosis and Delayed Liver Commitment for Proliferation after Partial Hepatectomy

This is an open-access article distributed under the terms of the Creative Commons Attribution License.[Background]: The role of thyroid hormones and their receptors (TR) during liver regeneration after partial hepatectomy (PH) was studied using genetic and pharmacologic approaches. Roles in liver regeneration have been suggested for T3, but there is no clear evidence distinguishing the contribution of increased amounts of T3 from the modulation by unoccupied TRs. [Methodology/Principal Findings]: Mice lacking TR alpha 1/TR beta or TR beta alone fully regenerated liver mass after PH, but showed delayed commitment to the initial round of hepatocyte proliferation and transient but intense apoptosis at 48h post-PH, affecting similar to 30% of the remaining hepatocytes. Pharmacologically induced hypothyroidism yielded similar results. Loss of TR activity was associated with enhanced nitrosative stress in the liver remnant, due to an increase in the activity of the nitric oxide synthase (NOS) 2 and 3, caused by a transient decrease in the concentration of asymmetric dimethylarginine (ADMA), a potent NOS inhibitor. This decrease in the ADMA levels was due to the presence of a higher activity of dimethylarginineaminohydrolase-1 (DDAH-1) in the regenerating liver of animals lacking TR alpha 1/TR beta or TR beta. DDAH-1 expression and activity was paralleled by the activity of FXR, a transcription factor involved in liver regeneration and up-regulated in the absence of TR. [Conclusions/Significance]: We report that TRs are not required for liver regeneration; however, hypothyroid mice and TR beta-or TR alpha 1/TR beta-deficient mice exhibit a delay in the restoration of liver mass, suggesting a specific role for TRb in liver regeneration. Altered regenerative responses are related with a delay in the expression of cyclins D1 and E, and the occurrence of liver apoptosis in the absence of activated TRb that can be prevented by administration of NOS inhibitors. Taken together, these results indicate that TRb contributes significantly to the rapid initial round of hepatocyte proliferation following PH, and improves the survival of the regenerating liver at later times.This work was supported by grants BFU2008-02161, BFU2007-62402, SAF2007-60511, and SAF2007-60551 from MICINN; S-BIO-0283/2006 from Comunidad de Madrid and FIS-RECAVA RD06/0014/0025 to L.B.; and PI05.0050, PI080070, and the Fundacion Mutua Madrileña to S.H. RECAVA and Ciberehd are funded by the Instituto de Salud Carlos III. R. L-F. is supported by a fellowship from Instituto de Salud Carlos III. The CNIC is supported by the Spanish Ministry of Science and Innovation and the Pro-CNIC Foundation.Peer reviewe

The evolution of the North Atlantic Oscillation for the last 700 years inferred from D/H isotopes in the sedimentary record of Lake Azul (Azores archipelago, Portugal).

TheD plant leaf wax variations provide insights on precipitation and evaporation evolution through time. This proxy has been used to reconstruct the temporal evolution of the North Atlantic Oscillation (NAO) climate mode since this mode rules most of the climate variability in the central North Atlantic area. A total lipid extraction preparation and the correspondent analyses in the IRMS have been done for 100 samples from the uppermost 1.5 m of the sedimentary infill of Lake Azul (Azores archipelago, Portugal). According to the chronological model, established by 210Pb profile and 4 AMS 14C dates, this record contains the environmental history of the last 730 years. The reconstructed precipitation variations obtained from D/H isotope values, suggest that this area has suffered significant changes in its distribution and intensity rainfall patterns through time. The end of the Medieval Climate Anomaly (MCA, 1100- 1300 AD) is characterized by a progressive enrichmentof D/H isotope values which meant decreasing arid conditions. These rainfalls’ increase might be interpreted by a shift from positive to negative dominance of the NAO. The Little Ice Age (LIA, 1300 - 1850 AD) was characterized by two humid periods (1300- 1550 AD and 1650 - 1850 AD) separated by a relatively dry period. These precipitation oscillations are clearly visible by marked changes in the D/H isotope values. The LIA was followed by the persistence of the positive NAO mode, exhibited by the depletion of the D/H isotope signal, which indicated an overall decrease of the precipitation in the central North Atlantic area. Surprisingly, the D/H of the last 100 years, characterized by the present global warming and a persistent positive NAO mode, display large fluctuations most possibly linked to an enhancement of the storminess which is in concordance with the data fluctuations observed in the instrumental record for the last 80 years in the archipelago. This climatic evolution is in accordance with other NAO records of the North Atlantic region (Trouet et al., 2012) highlighting the validity of the D/H isotopes as precipitation proxy.Peer Reviewe

Stabilization of microturbulence by fast ions n ASDEX upgrade

The goal of the present work is to study the impact of fast ions, generated by ICRH, on microturbulence. Our methodology is similar to that in [2] and is based on extensive simulations of discharges carried out on the ASDEX Upgrade (AUG) tokamak, in Germany using state-of-art fusion simulations codes

Casimir Effects Near the Big Rip Singularity in Viscous Cosmology

Analytical properties of the scalar expansion in the cosmic fluid are investigated, especially near the future singularity, when the fluid possesses a constant bulk viscosity \zeta. In addition, we assume that there is a Casimir-induced term in the fluid's energy-momentum tensor, in such a way that the Casimir contributions to the energy density and pressure are both proportional to 1/a^4, 'a' being the scale factor. A series expansion is worked out for the scalar expansion under the condition that the Casimir influence is small. Close to the Big Rip singularity the Casimir term has however to fade away and we obtain the same singular behavior for the scalar expansion, the scale factor, and the energy density, as in the Casimir-free viscous case.Comment: 7 pages RevTeX, no figures. Minor changes in discussion, some references added. To appear in Gen. Rel. Gra

Modelling the cardiovascular system for assessing the blood pressure curve

A four compartment model of the cardiovascular system is developed. To allow for easy interpretation and to minimise the number of parameters, an effort was made to keep the model as simple as possible. Using a standard method (Matlab function fminsearch) to calculate the parameter values led to unacceptable run times or non-convergence. Consequently we developed an algorithm which first finds the most important model parameters and uses these as a basis for a four stage process which accurately determines all parameter values. This process is then applied to data from three ICU patients. Good agreement between the model and measured arterial pressure is demonstrated in all cases