Equivalence of the dynamics of nonholonomic and variational nonholonomic systems for certain initial data

"In this paper, we discuss the necessary and sufficient conditions for the equivalence of the dynamics of nonholonomic mechanics and variational nonholonomic (vakonomic) dynamics for certain initial conditions. We derive a priori results for identifying equivalence and, specializing to Abelian Chaplygin systems, prove that equivalence results if and only if the constrained nonholonomic equations are Lagrangian. We eliminate the need to solve the variational nonholonomic problem when checking equivalence by obtaining explicit formulae for the system's multipliers, and then derive conditions under which the multiplier free Lagrangian gives equivalence of the dynamics. We consider nonholonomic systems possessing invariant measures, showing when equivalence and Hamiltonization are the same. We also derive conditions under which measure-preserving systems exhibit equivalence. We apply the results to many of the known nonholonomic systems."http://deepblue.lib.umich.edu/bitstream/2027.42/64185/1/a8_34_344005.pd

Sector Agroalimentario e Integración Regional: una simbiosis necesaria para la Seguridad Alimentaria y Nutricional

Through a documentary-descriptive and quantitative-analytical research, supported by calculation and interpretation of trade position and intraregional trade dynamics indicators, this work examines relationship between agriculture, regional integration and food security. For this reason, it analyzes the role played by agricultural variable in the context of integration agreements, characterizes elements that confer sensitivity to agri-food sector and conditions its special treatment within regionalism experiences, and evaluates current state of regional agri-food integration between 2001 and 2019 by comparing three Latin American schemes: ALADI, CAN and MERCOSUR. The central discussion argues that deepening of agri-food trade through economic integration offers opportunities to guarantee food security, as an instrument capable of supplying food in a stable and fluid way (facing turbulences in international markets) and with lower transaction costs. It is concluded that in Latin America there is no integration from the agri-food trade point of view and offers public policies recommendations for agricultural development, trade and strengthening integration.Mediante una investigación documental-descriptiva y cuantitativa-analítica, apoyada en el cálculo e interpretación de indicadores de posición comercial y dinámica del comercio intrarregional, el trabajo examina la relación existente entre agricultura, integración regional y seguridad alimentaria. Para ello analiza el papel desempeñado por la variable agrícola en el contexto de los acuerdos de integración, caracteriza los elementos que confieren sensibilidad al sector agroalimentario y condicionan su tratamiento especial dentro de las experiencias de regionalismo y evalúa el estado de la integración agroalimentaria regional entre 2001 y 2019 comparando tres esquemas latinoamericanos: ALADI, CAN y MERCOSUR. La discusión central argumenta que la profundización del comercio agroalimentario a través de la integración económica ofrece oportunidades para garantizar la seguridad alimentaria, como instrumento capaz de suministrar alimentos de manera estable y fluida, frente a las turbulencias en los mercados internacionales y con costos transaccionales más bajos. Se concluye que en América Latina no existe integración desde el punto de vista del intercambio agroalimentario y se ofrece una serie de recomendaciones a nivel de políticas públicas en aras del desarrollo agrícola, del comercio y del fortalecimiento de la integración

Euro Stoxx 50: 1997-2005. Shareholder value creation in Europe

2005 was a very good year for the shareholders of the companies in the Euro Stoxx 50. The shareholder value creation of these 50 companies was €292.9 billion. The companies that created most value for their shareholders were Total (€30 billion), Sanofi-Synthelabo (€23.2 billion) and Eni (€20.7 billion). The companies that destroyed most value were telecoms: Deutsche Telekom (€-14.8 billion), France Telecom (€-11.8 billion) and Telecom Italia (€-7.1 billion). In 2005, the Euro Stoxx 50 was slightly more volatile than the S&P 500. Shareholder value creation in the three-year period 2003-2005 was €551 billion. The market value of the 50 companies included in the Euro Stoxx 50 was €2.1 trillion in 2005, although only €1.8 trillion were included in the index. SAP was the top shareholder value creator and Deutsche Telekom the top shareholder value destroyer during the eight-year period 1997-2005. A portfolio long in the companies that entered the index and short in the companies that abandoned the index had on average a 6.85% return in the 20 days prior to the index recomposition and a 0.97% return in the 20 days after the index recomposition.shareholder value creation; created shareholder value; shareholder value added; shareholder return; required return to equity;

Nonholonomic Hamilton-Jacobi Theory via Chaplygin Hamiltonization

We develop Hamilton-Jacobi theory for Chaplygin systems, a certain class of nonholonomic mechanical systems with symmetries, using a technique called Hamiltonization, which transforms nonholonomic systems into Hamiltonian systems. We give a geometric account of the Hamiltonization, identify necessary and sufficient conditions for Hamiltonization, and apply the conventional Hamilton-Jacobi theory to the Hamiltonized systems. We show, under a certain sufficient condition for Hamiltonization, that the solutions to the Hamilton-Jacobi equation associated with the Hamiltonized system also solve the nonholonomic Hamilton-Jacobi equation associated with the original Chaplygin system. The results are illustrated through several examples.Comment: Accepted for publication in Journal of Geometry and Physic

Mobile y Cloud: plataforma de desarrollo Android, experiencia de aprendizaje en robótica

Las rápidos avances tecnológicos han provocado cambios en las distintas ramas que componen la disciplina Informática, proliferando una variedad de herramientas que facilitan el desarrollo de aplicaciones muy diversas. Este trabajo presenta un desarrollo basado en Android, disponible en Cloud y aplicado a un proyecto interdisciplinario de robótica. Se presenta una síntesis de la construcción de un brazo robótico enfatizando en la programación de su dinámica, sobre la plataforma App Inventor. Se realizaron pruebas y ajustes sobre el mismo y al finalizar se plantean conclusiones al respecto y trabajos futuros a abordar.VI Workshop Innovación en Sistemas de Software (WISS)Red de Universidades con Carreras de Informática (RedUNCI

Mobile y Cloud: plataforma de desarrollo Android, experiencia de aprendizaje en robótica

Las rápidos avances tecnológicos han provocado cambios en las distintas ramas que componen la disciplina Informática, proliferando una variedad de herramientas que facilitan el desarrollo de aplicaciones muy diversas. Este trabajo presenta un desarrollo basado en Android, disponible en Cloud y aplicado a un proyecto interdisciplinario de robótica. Se presenta una síntesis de la construcción de un brazo robótico enfatizando en la programación de su dinámica, sobre la plataforma App Inventor. Se realizaron pruebas y ajustes sobre el mismo y al finalizar se plantean conclusiones al respecto y trabajos futuros a abordar.VI Workshop Innovación en Sistemas de Software (WISS)Red de Universidades con Carreras de Informática (RedUNCI

Mobile y Cloud: plataforma de desarrollo Android, experiencia de aprendizaje en robótica

Las rápidos avances tecnológicos han provocado cambios en las distintas ramas que componen la disciplina Informática, proliferando una variedad de herramientas que facilitan el desarrollo de aplicaciones muy diversas. Este trabajo presenta un desarrollo basado en Android, disponible en Cloud y aplicado a un proyecto interdisciplinario de robótica. Se presenta una síntesis de la construcción de un brazo robótico enfatizando en la programación de su dinámica, sobre la plataforma App Inventor. Se realizaron pruebas y ajustes sobre el mismo y al finalizar se plantean conclusiones al respecto y trabajos futuros a abordar.VI Workshop Innovación en Sistemas de Software (WISS)Red de Universidades con Carreras de Informática (RedUNCI

Contribution of the single photon emission computed tomography with 99mTc red blood cells in splenosis

The term splenosis refers to the presence of auto-transplanted splenic tissue in a heterotopic location. These foci can be localized to the liver simulating a malignant lesion. Sometimes these lesions are difficult to identify using conventional imaging techniques (ultrasound, CT and MR). Then, a scan with denatured erythrocytes marked with 99mTc has proven to be an effective technique to confirm the diagnosis of splenosis and to establish its extension. The incorporation of hybrid imaging techniques (SPECT-CT) into usual clinical practice has increased the precision of the localization of these foci of splenosis. We hereby report the cases of two patients diagnosed with splenosis, the first by laparotomy and the second after performing scintigraphy with red blood cells labeled with 99mTc. In the first case, the laparotomy revealed numerous reticulated nodules on the diaphragmatic peritoneal surface, the transverse colon and the right kidney. Finally, the anatomopathological diagnosis confirmed a case of splenosis. In the second case, the results of the 99mTc marked red blood cell gammagraphy and SPECT-CT were consistent with the diagnosis of splenosis in the patient. To obtain correct information in cases of lesions highly suspicious of splenosis, 99mTc marked red blood cell gammagraphy should be performed due to the high sensitivity and specificity of the test. Combined diagnostic imaging (SPECT-CT), have increased the specificity of this test due to improvements in the characterization of lesions. We believe that the use of this technique will help avoid unnecessary surgical procedures

POLD3 Is Haploinsufficient for DNA Replication in Mice

The Pold3 gene encodes a subunit of the Polδ DNA polymerase complex. Pold3 orthologs are not essential in Saccharomyces cerevisiae or chicken DT40 cells, but the Schizosaccharomyces pombe ortholog is essential. POLD3 also has a specialized role in the repair of broken replication forks, suggesting that POLD3 activity could be particularly relevant for cancer cells enduring high levels of DNA replication stress. We report here that POLD3 is essential for mouse development and is also required for viability in adult animals. Strikingly, even Pold3(+/-) mice were born at sub-Mendelian ratios, and, of those born, some presented hydrocephaly and had a reduced lifespan. In cells, POLD3 deficiency led to replication stress and cell death, which were aggravated by the expression of activated oncogenes. Finally, we show that Pold3 deletion destabilizes all members of the Polδ complex, explaining its major role in DNA replication and the severe impact of its deficiency.Research was funded by Fundacion Botin, Banco Santander, through its Santander Universities Global Division, and by grants from the Spanish Ministry of Economy and Competitiveness (MINECO) (SAF2014-59498-R; SAF2014-57791-REDC), Fundacio La Marato de TV3, the Howard Hughes Medical Institute, and the European Research Council (ERC-617840) to O.F.-C.; by a Marie Curie International Outgoing Fellowshp (IOF) from the FP7 Marie Curie Actions and a grant from MINECO (BFU2014-55168-JIN) that was co-funded by European Regional Development Funds (FEDER) to E.L.; by a grant from MINECO (BFU2013-49153) to J.M.; and by the European Commission (ERC grant ONIDDAC) to T.D.H.S