373 research outputs found

    Kinematics of Herbig-Haro Objects and Jets in the Orion Nebula

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    We have surveyed the inner 5' of the Orion Nebula by means of Halpha and [NII] Fabry-Perot imaging spectroscopy to present a kinematical study of the Herbig-Haro objects in the nebula. The objects studied in this work are HH 202, 203, 204, 529, 269 and other associated features. For HH 202 we find new features that, because of their high velocities (up to 100 km/seg) indicate the presence of an outflow that probably is a HH flow not catalogued previously. HH 202 could be only a part of this larger outflow. Large internal motions are found in the fainter regions of HH 203-204, as well as evidence of transverse density gradients that could account for the asymmetry in the brightness distribution of HH 204. We report for the first time a high blueshifted velocity (-118 km/seg) associated with HH 204, and show that the apex of HH 204 is indeed the zone of maximum velocity, in agreement with bow shock models. We also studied the radial velocity field of HH 269 finding features associated with the HH object. From our studies, we find kinematic evidence that suggests that HH 203-204 and HH 202 are part of a big (aprox. 0.55 pc) bipolar HH outflow.Comment: 24 pages, 10 figures (in three jpg files). To be Published in Astronomical Journa

    Confirmation of symmetrical distributions of clinical attachment loss and tooth loss in a homogeneous Mexican adult male population

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    Background/purpose To ascertain whether or not clinical attachment loss and tooth loss are present with similar severity and prevalence across the two sides of the mouth in a homogeneous sample of urban male adults. Materials and methods A cross-sectional study was carried out on 161 policemen (a largely homogeneous group in terms of ethnic background, socioeconomic status, sex, occupation, and medical/dental insurance) in Campeche, Mexico. Periodontal examinations were undertaken using the Florida Probe System in a dental chair by one trained and standardized examiner (kappa ≥ 0.60) to determine clinical attachment loss and tooth loss. We examined six sites in all teeth present in the mouth (a maximum of 168 sites, no third molars). Because of correlated data between observations, McNemar (for tooth loss) and Wilcoxon (for attachment loss) signed-rank tests were used to compare right and left sites within the same patient. Results The mean age was 38.4 ± 11.0 years. The mean number of teeth present was 24.4 ± 4.6; the mean number of periodontal sites/person was 146.7 ± 27.8. All P values were ≥ 0.05 (except for attachment loss in the upper first premolars), suggesting that there were no statistically significant differences between the right and left sides for the frequency of presentation of these two conditions. Conclusion Tooth loss and attachment loss measurements largely resemble each other on both sides of the mouth

    Economic Growth, CO2 Emissions and Electric Consumption: Is there an Environmental Kuznets Curve? An Empirical Study for North America Countries

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    The goal of this paper is validity the environmental Kuznets curve (EKC) hypothesis for north America countries (Canada, United States and Mexico) over the annual period 1980–2008. Pedroni cointegration tests are applied for testing long-run relationship between the variables. Using the panel fully modified ordinary least squares (FMOLS) and the panel dynamic ordinary least squares (DOLS) determinate the elasticities of the long-run relationships. The results show that there is an inverted U-shape relationship. Finally, in the long-run, the results of the causality test show that there is a unidirectional causal flow from energy consumption, electricity consumption and economic growth to CO2 emissions in North America. Keywords: Environmental Kuznets Curve, Carbon Dioxide Emissions, Economic Growth. JEL Classifications: C33, Q4, Q43, Q5

    Influencia de actores y del contexto político en el diseño e implementación de la reforma del Sistema Privado de Pensiones del 2012

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    La presente tesis tiene como propósito explicar cómo influyeron los actores involucrados, así como el contexto político existente en el diseño e implementación de la reforma al Sistema Privado de Pensiones (SPP) aprobada en el 2012, durante el gobierno del presidente Ollanta Humala. Para ello, se ha realizado una investigación bibliográfica, se revisaron las entrevistas y declaraciones dadas por los actores involucrados en medios de prensa, y se efectuaron entrevistas con algunos participantes directos en el diseño de la política pública analizada. La investigación muestra que existieron actores clave, como el Presidente de la República, el Ministro de Economía y Finanzas, el Superintendente de Banca, Seguros y AFP y algunos congresistas del partido de gobierno, que tuvieron un rol importante en el diseño de la reforma, pues establecieron lineamientos y tomaron decisiones que orientaron el contenido de la reforma y permitieron su aprobación. Estos lineamientos estuvieron influenciados, a su vez, por otros actores, como la Asociación de AFP y los medios de comunicación que, en el periodo comprendido entre la primera y la segunda vuelta electoral, realizaron acciones para lograr que la reforma al sistema de pensiones tenga un alcance limitado. En la implementación de la reforma, participaron los mismos actores y adicionalmente, se aprecia una mayor participación e influencia de los partidos de oposición y de la sociedad civil, lo cual unido al desgaste del gobierno y errores en el diseño, permitieron que algunos aspectos de la reforma no se logren implementar.Tesi

    An AER handshake-less modular infrastructure PCB with x8 2.5Gbps LVDS serial links

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    Nowadays spike-based brain processing emulation is taking off. Several EU and others worldwide projects are demonstrating this, like SpiNNaker, BrainScaleS, FACETS, or NeuroGrid. The larger the brain process emulation on silicon is, the higher the communication performance of the hosting platforms has to be. Many times the bottleneck of these system implementations is not on the performance inside a chip or a board, but in the communication between boards. This paper describes a novel modular Address-Event-Representation (AER) FPGA-based (Spartan6) infrastructure PCB (the AER-Node board) with 2.5Gbps LVDS high speed serial links over SATA cables that offers a peak performance of 32-bit 62.5Meps (Mega events per second) on board-to-board communications. The board allows back compatibility with parallel AER devices supporting up to x2 28-bit parallel data with asynchronous handshake. These boards also allow modular expansion functionality through several daughter boards. The paper is focused on describing in detail the LVDS serial interface and presenting its performance.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02/01Ministerio de Economía y Competitividad TEC2012-37868-C04-02/01Junta de Andalucía TIC-6091Ministerio de Economía y Competitividad PRI-PIMCHI-2011-076

    Model transform and local parameters. Application to instantaneous attractors

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    The model transform fits exactly the parameters of a suitable model to empirical or simulated data in each point in time and/or space. We describe several examples of concrete model transforms and their applications. The model transform allows simple theoretical models to be applied to complex empirical systems in each short interval of time or/and in each local neighborhood. The model can be chosen to identify, for instance, the temporal evolution of the attractor landscape for empirical systems which depict a complex dynamics over time

    Live Demonstration: Multiplexing AER Asynchronous Channels over LVDS Links with Flow-Control and Clock- Correction for Scalable Neuromorphic Systems

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    In this live demonstration we exploit the use of a serial link for fast asynchronous communication in massively parallel processing platforms connected to a DVS for realtime implementation of bio-inspired vision processing on spiking neural networks

    FKBP52 is involved in the regulation of SOCE channels in the human platelets and MEG 01 cells

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    AbstractImmunophilins are FK506-binding proteins that have been involved in the regulation of calcium homeostasis, either by modulating Ca2+ channels located in the plasma membrane or in the rough endoplasmic reticulum (RE). We have investigated whether immunophilins would participate in the regulation of stored-operated Ca2+ entry (SOCE) in human platelets and MEG 01. Both cell types were loaded with fura-2 for determining cytosolic calcium concentration changes ([Ca2+]c), or stimulated and fixed to evaluate the protein interaction profile by performing immunoprecipitation and western blotting. We have found that incubation of platelets with FK506 increases Ca2+ mobilization. Thapsigargin (TG)-evoked, Thr-evoked SOCE and TG-evoked Mn2+ entry resulted in significant reduction by treatment of platelets with immunophilin antagonists. We confirmed by immunoprecipitation that immunophilins interact with transient receptor potential channel 1 (TRPC1) and Orai1 in human platelets. FK506 and rapamycin reduced the association between TRPC1 and Orai1 with FK506 binding protein (52) (FKBP52) in human platelets, and between TRPC1 and the type II IP3R, which association is known to be crucial for the maintenance of SOCE in human platelets. FKBP52 role in SOCE activation was confirmed by silencing FKBP52 using SiRNA FKBP52 in MEG 01 as demonstrated by single cell configuration imaging technique. TRPC1 silencing and depletion of cell of TRPC1 and FKBP52 simultaneously, impair activation of SOCE evoked by TG in MEG 01. Finally, in MEG 01 incubated with FK506 we observed a reduction in TRPC1/FKBP52 coupling, and similarly, FKBP52 silencing reduced the association between IP3R type II and TRPC1 during SOCE. All together, these results demonstrate that immunophilins participate in the regulation of SOCE in human platelets

    Existence and nonexistence of unbounded forward attractor for a class of non-autonomous reaction diffusion equations

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    The goal of this work is to study the forward dynamics of positive solutions for the nonautonomous logistic equation ut − ∆u = λu − b(t)up, with p > 1, b(t) > 0, for all t ∈ R, limt→∞ b(t) = 0. While the pullback asymptotic behaviour for this equation is now well understood, several different possibilities are realised in the forward asymptotic regime.Ministerio de Educación y Cienci
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