Forecasting Interest Rates: an application for Brazil

Understanding the links between long and short-term interest rates is crucial for monetary policy makers, since Central Banks decide and set short-term interest rates in order to affect indirectly long-term interest rates, which affects aggregate spending. This paper studies whether VAR/VEC models are useful in predicting long-term interest rates for Brazil. The empirical results suggest that these models are useful in building qualitative scenarios for the Term structure of interest rates, but do not provide good forecasts in terms of accuracy. Furthermore, models that assume that the future path of short-term interest rates (target interest rates) is known by forecasters do not perform better in terms of both directional and forecasting accuracy.

Ultra-high sensitivity moment magnetometry of geological samples using magnetic microscopy

Useful paleomagnetic information is expected to be recorded by samples with moments up to three orders of magnitude below the detection limit of standard superconducting rock magnetometers. Such samples are now detectable using recently developed magnetic microscopes, which map the magnetic fields above room-temperature samples with unprecedented spatial resolutions and field sensitivities. However, realizing this potential requires the development of techniques for retrieving sample moments from magnetic microscopy data. With this goal, we developed a technique for uniquely obtaining the net magnetic moment of geological samples from magnetic microscopy maps of unresolved or nearly unresolved magnetization. This technique is particularly powerful for analyzing small, weakly magnetized samples such as meteoritic chondrules and terrestrial silicate crystals like zircons. We validated this technique by applying it to field maps generated from synthetic sources and also to field maps measured using a superconducting quantum interference device (SQUID) microscope above geological samples with moments down to 10⁻¹⁵ Am². For the most magnetic rock samples, the net moments estimated from the SQUID microscope data are within error of independent moment measurements acquired using lower sensitivity standard rock magnetometers. In addition to its superior moment sensitivity, SQUID microscope net moment magnetometry also enables the identification and isolation of magnetic contamination and background sources, which is critical for improving accuracy in paleomagnetic studies of weakly magnetic samples.National Science Foundation (U.S.) (DMS-1521765)National Science Foundation (U.S.) (DMS-0934689)Peterson, Thomas F

Impact assessment of interregional government transfers in Brazil: an input-output approach

Redistributive policies carried out by the central government through interregional government transfers is a relevant feature of the Brazilian federal fiscal system. Regional shares of the central government revenues in the poorer regions have been recurrently smaller than the shares of central government expenditures in those regions. Appeal to core-periphery outcomes could be made, as São Paulo, the wealthiest state in the country, concentrated, in 2005, over 40% of total Federal tax revenue, receiving less than 35% of Federal expenditures. These figures suggest a redistribution of public funds from the spatial economic core of the economy to the peripheral areas. This paper investigates the role interregional transfers play in the redistribution of activities in the country, using an interregional input-output approach. Counterfactual simulations allow us to estimate some costs and benefits, for the core and periphery respectively, from such fiscal mechanisms.Interregional government transfers, input-output analysis, impact analysis, Brazilian economy

The role of the disorder range and electronic energy in the graphene nanoribbons perfect transmission

Numerical calculations based on the recursive Green's functions method in the tight-binding approximation are performed to calculate the dimensionless conductance $g$ in disordered graphene nanoribbons with Gaussian scatterers. The influence of the transition from short- to long-ranged disorder on $g$ is studied as well as its effects on the formation of a perfectly conducting channel. We also investigate the dependence of electronic energy on the perfectly conducting channel. We propose and calculate a backscattering estimative in order to establish the connection between the perfectly conducting channel (with $g=1$) and the amount of intervalley scattering.Comment: 7 pages, 9 figures. To be published on Phys. Rev.

Towards an integrated stratigraphy of the Gramame Formation (Maastrichtian), CIPASA quarry, Pernambuco-Paraíba Basin, NE Brazil

This study presents the integrated biostratigraphic (calcareous nannofossils and foraminifera), petrographic, geochemical and ichnological analyzes of the Gramame Formation (Maastrichtian) at the CIPASA Quarry section, in the Pernambuco-Paraíba Basin, northeastern Brazil. A high resolution calcareous nannofossil biostratigraphic study has been carried out, allowing to subdivide the studied section into three subzones of Maastrichtian age: CC25A, CC25B, and CC25C. Each biostratigraphic unit was further characterized by petrographic, geochemical and ichnological parameters. During the Maastrichtian the area was characterized by a dry and warm climate with low influx of terrigenous sediments. These conditions were fundamental to the widespread development of a carbonate ramp system in an outer neritic to bathyal setting, with deposition of alternating calcareous mudstones and argillaceous mudstones of the Gramame Formation. The Gramame Formation belongs to the transgressive system tract of second-order type, characteristic of a Passive Margin Sequence. The studied section consists of part of a third order deposicional cycle, which is arranged in a transgressive systems tract and a highstand systems tract. The lowstand systems tract was not characterized

Compact beam-steerable lens antenna for 60-GHz wireless communications

WOS:000270723500012 (Nº de Acesso Web of Science)This paper presents a new concept of steerable beam antenna composed by a dielectric lens which pivots in front of a single stationary moderate gain feed. The lens not only allows steering mechanically the beam in elevation and full azimuth, but further increases the gain up to 21 dBi. The solution is broadband, including the entire international unlicensed spectrum from 57 GHz to 66 GHz. A fabricated prototype shows the possibility of tilting the beam from - 45deg to + 45deg for all azimuths with gain scan loss below 1.1 dB and radiation efficiency above 95%. The arrangement is very simple, it does not require rotary joints, it is low cost and compact, lens plus feed volume being of the order of 3 times 3 times 3 cm3 with lens weight less than 10 g

Balance and aerobic capacity of independent elderly: a longitudinal cohort study

OBJETIVO: Avaliar a variação da capacidade aeróbica e do equilíbrio postural em idosos independentes por um período de três anos. MÉTODOS: A capacidade aeróbica dos voluntários foi avaliada por meio do Teste de Caminhada de 6 minutos (TC6); o equilíbrio postural, por meio da Escala de Equilíbrio de Berg (EEB); o número de quedas foi registrado por autorrelato e o nível de atividade física, pelo Questionário Internacional de Atividade Física (IPAQ - versão longa). As avaliações realizadas em 2008 foram comparadas às realizadas em 2005. RESULTADOS: Não houve diferença na pontuação da EEB e no número de quedas dos idosos avaliados (p>0,05). Houve diminuição da distância percorrida entre as duas avaliações, sendo que os voluntários percorreram 52,46±8,4 metros a menos na segunda avaliação. O IPAQ evidenciou aumento de indivíduos considerados ativos na segunda avaliação (83,3%). CONCLUSÃO: O presente estudo demonstrou que o equilíbrio postural, avaliado pela EEB, não se alterou nos idosos independentes e ativos no período de três anos. Nesse mesmo momento, observou-se uma redução da distância percorrida, avaliada pelo TC6.OBJECTIVE: To evaluate the variation in aerobic capacity and postural balance of independents elderly for a period of three years. METHODS: The aerobic capacity of the volunteers was assessed using a six minutes walk test (6MWT), the postural balance was assessed using the Berg Balance Scale (BBS), the number of falls was self-reported and physical activity level was assessed using the International Physical Activity Questionnaire (IPAQ - long version). Evaluations undertaken in 2008 were compared to those performed in 2005. RESULTS: There were no differences in balance and number of falls between 2008 and 2005 (p>0.05). There was a decrease in aerobic capacity over time of 52.46±8.4 meters walked. The IPAQ showed an increase in physical activity on the second evaluation (83.3%). CONCLUSION: The present study demonstrated that balance, evaluated using BBS did not change in the active independent elderly for a period of three years. However, over the there year period there was a decrease in aerobic capacity evaluated using the 6MWT