3,283 research outputs found

    The Effect of Adverse Oil Price Shocks on Monetary Policy and Output Using a Dynamic Small Open Economy General Equilibrium Model With Staggered Price for Brazil

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    The aim of the present research is to use a model economy built for Brazil, based on an optimizing dynamic general equilibrium model, in order to perform numerical simulations to derive the ability of the artificial economy to explain the impact of monetary policy interventions on Brazilian short run economic performance in terms of the inflation rate, output gap, interest rate and level of economic activity in the face of an adverse oil shock. It is an extension of Bugarin et al. (2005) concentrating on the consequence of energy price increases, facing different monetary policy rules. Following Hall (1988 e 1990) and Finn (2000) it is considered that an increase in energy prices acts like a negative productivity shock. The model provides an accessible description of an artificial economy with a tractable micro-founded dynamic setting with forward looking rational agents in a small open economy with a staggered pricing mechanism that generates inflation inertia and recessionary disinflations. Alternative specification of monetary reaction functions are introduced into the model economy in order to perform a sensitivity analysis of derived impulse responses to those interventions facing the negative productivity shock. The preliminary results suggest that the introduction of habit persistence into the consumption hypothesis does not make much difference. However the introduction of different monetary reaction functions does alter the impulse response of output, inflation rate, and nominal interest rate. A common result is the decline in potential output for all models. Additionally, the only case where a reduction in the output gap is observed is when using the Taylor rule that takes into consideration the output gap and past interest rates with high persistence.

    CTQ 839: Candidate for the Smallest Projected Separation Binary Quasar

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    We report the discovery of the new double quasar CTQ 839. This B = 18.3, radio quiet quasar pair is separated by 2.1" in BRIH filters with magnitude differences of delta m_B = 2.5, delta m_R = delta m_I = 1.9, and delta m_H = 2.3. Spectral observations reveal both components to be z = 2.24 quasars, with relative redshifts that agree at the 100 km/s level, but exhibit pronounced differences in the equivalent widths of related emission features, as well as an enhancement of blue continuum flux in the brighter component longward of the Ly alpha emission feature. In general, similar redshift double quasars can be the result of a physical binary pair, or a single quasar multiply imaged by gravitational lensing. Empirical PSF subtraction of R and H band images of CTQ 839 reveal no indication of a lensing galaxy, and place a detection limit of R = 22.5 and H = 17.4 for a third component in the system. For an Einstein-de Sitter cosmology and SIS model, the R band detection limit constrains the characteristics of any lensing galaxy to z_lens >= 1 with a corresponding luminosity of L >~ 5 L_*, while an analysis based on the redshift probability distribution for the lensing galaxy argues against the existence of a z_lens >~ 1 lens at the 2 sigma level. A similar analysis for a Lambda dominated cosmology, however, does not significantly constrain the existence of any lensing galaxy. The broadband flux differences, spectral dissimilarities, and failure to detect a lensing galaxy make the lensing hypothesis for CTQ 839 unlikely. The similar redshifts of the two components would then argue for a physical quasar binary. At a projected separation of 8.3/h kpc (Omega_matter = 1), CTQ 839 would be the smallest projected separation binary quasar currently known.Comment: Latex, 23 pages including 5 ps figures; accepted for publication in A

    New old star clusters in the Small Magellanic Cloud

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    Using Ca triplet spectroscopy and P SF photometry performed on data taken with the “Very Large Telescope” (Chile), we derived reliable ages and metallicities of 15 Small Magellanic Cloud (SMC) star clusters. Three of them were found to be very old clusters so that the determination of their fundamental properties allows us to improve our current knowledge on the SMC chemical evolution during the earliest epochs. Based on our new data, we further discuss the age-metallicity relation. The procedures and results included in this article will be presented in a more extensive and detailed way in Parisi et al. (2011 - in preparation).Usando espectroscopıa del Triplete del Calcio Ionizado y fotometrıa P SF realizada sobre datos tomados con el “Very Large Telescope” (Chile), derivamos edades y metalicidades confiables de 15 cumulos estelares de la Nube Menor de Magallanes (NmM). Encontramos que 3 de ellos son cumulos muy viejos, por lo que la determinacion de sus propiedades fundamentales permite mejorar nuestro actual conocimiento sobre la evolucion quımica de la NmM durante su etapa mas temprana. Basados en nuestros nuevos datos, rediscutimos la relacion edad-metalicidad en esta galaxia. Los procedimientos y resultados incluidos en este artıculo, seran presentados de manera mas extensa y detallada en Parisi et al. (2011 - en preparacion).Fil: Parisi, M. C.. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Geisler, D.. Universidad de Concepción; ChileFil: Grocholski, A. J.. University of Florida; Estados UnidosFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Carraro, G.. European Southern Observatory; ChileFil: Costa, E.. Universidad de Chile; ChileFil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Sarajedini, A.. University of Florida; Estados UnidosFil: Leiton, R.. Universidad de Concepción; Chil

    Magnetic resonance imaging-guided occult breast lesion localization and simultaneous sentinel lymph node mapping

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    Background: Radio-guided occult lesion localization is a valid technique for the diagnosis of suspicious non-palpable lesions. Here we determine the feasibility of pre-operative localization of occult suspect non-palpable breast lesions using radio-guided occult lesion localization, as well as for identifying the sentinel lymph node.Methods: This is a descriptive study of data collected retrospectively. Pre-operative mapping of 34 breast lesions in 25 patients suspected of being malignant was performed using conventional imaging methods with a magnetic resonance imaging-guided radiopharmaceutical injection.Results: the mean time required to perform the localization was 25 minutes. After resection of the lesions using a gamma probe, malignancy was confirmed in fifteen patients (60.0%), with nine invasive ductal carcinomas, two invasive lobular carcinomas, and four in situ ductal carcinomas the resection was confirmed by the complete removal of the radioactive material. the pathologic results and images were concordant in all but two cases, which were submitted for new magnetic resonance imaging examinations and surgery that confirmed the malignancies. of the 15 patients with confirmed malignancies, 10 had sentinel lymph node resection. of these, eight were negative for metastases, one had micro-metastases and one had confirmed metastases. Three patients had full axillary node dissection, with metastases found in only one. No side effects were observed with magnetic resonance-guided radiopharmaceutical injection.Conclusions: the sentinel node occult lesion localization technique is a simple, reproducible and effective alternative approach to occult lesions compared to other methods, such as mammotomy and the hook-wire localization technique, for mapping suspect breast lesions and identifying lymph node metastasis.Hosp Sirio Libanes, Magnet Resonance Imaging Dept, BR-01308000 SĂŁo Paulo, BrazilHosp Sirio Libanes, BR-01308000 SĂŁo Paulo, BrazilHosp Sirio Libanes, Mastol Studies Dept, BR-01308000 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Escola Paulista Med, Discipline Mastol, BR-04023062 SĂŁo Paulo, BrazilHosp Sirio Libanes, Dept Diagnost Imaging, BR-01308000 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Escola Paulista Med, Discipline Mastol, BR-04023062 SĂŁo Paulo, BrazilWeb of Scienc

    Assessing the validity of the MyJump2 app for measuring different jumps in professional cerebral palsy football players: an experimental study

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    Background: Vertical jumps can be used to assess neuromuscular status in sports performance. This is particularly important in Cerebral Palsy Football (CP Football) because players are exposed to high injury risk, but it may be complicated because the gold standard for assessing jump performance is scarce in field evaluation. Thus, field techniques, such as mobile apps, have been proposed as an alternative method for solving this problem. Objective: This study aims to evaluate the reliability of the measures of the MyJump2 app to assess vertical jump performance in professional CP Football. Methods: We assessed 40 male CP Football athletes (age 28.1 [SD 1.4] years, weight 72.5 [SD 6.2] kg, and height 176 [SD 4.2] cm) through the countermovement jump (CMJ) and squat jump (SJ) using a contact mat. At the same time, we assessed the athletes using the MyJump2 app. Results: There were no significant differences between the instruments in SJ height (P=.12) and flight time (P=.15). Additionally, there were no significant differences between the instruments for CMJ in jump height (P=.16) and flight time (P=.13). In addition, it was observed that there were significant and strong intraclass correlations in all SJ variables varying from 0.86 to 0.89 (both P<.001), which was classified as "almost perfect." Similar results were observed in all variables from the CMJ, varying from 0.92 to 0.96 (both P <=.001). Conclusions: We conclude that the MyJump2 app presents high validity and reliability for measuring jump height and flight time of the SJ and CMJ in CP Football athletes.7
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