As políticas monetárias não convencionais nos países avançados : características, efeitos e avaliações

Este trabalho tem como objetivo principal avaliar alguns possíveis impactos dos anúncios de políticas monetárias não convencionais na economia dos Estados Unidos e do Japão sobre algumas variáveis macroeconômicas. Para isso é discutido se o uso das políticas monetárias não convencionais, feitas pelo Federal Reserve, após a crise de 2007-2008, e pelo Banco do Japão no início dos anos 2000, foram eficazes em afetar a inflação, a taxa de desemprego, a taxa de câmbio e as taxas de juros de longo prazo, a fim de impulsionar o crescimento econômico. Também deseja-se identificar quais os canais de transmissão da política monetária foram mais eficazes no período que abrange 2008 a 2014, na economia dos Estados Unidos e entender o papel da política monetária, em um contexto de taxa nominal de juros próxima de zero.This paper has the main objective to measure some possible impacts of the anouncement of non conventional monetary policies in the economy of United States and Japan upon the macroeconomics variables. Therefore it will be tested if the use of conventional monetary policies made by the Federal Reserve, after the 2007-2008 crisis and by the Bank of Japan, were effective in affect the inflation rate, the unemployment rate, the exchange rate and the long term interest rate, to boost economic growth. As well, the paper aims to identify which transmission channels of monetary policy were more effective in the period between 2008 and 2014, on the United States economy and understand the role of monetary policy, in a context of nominal interest rate close to zero

Late effects on hypothalamic-pituitary function following treatment of paraselar tumours

O acompanhamento a longo prazo de pacientes submetidos a tratamento de tumores da região parasselar é importante para detectar complicações tardias da terapêutica. Neste estudo avaliamos 6 pacientes com craniofaringioma, 1 com meningioma, 1 com germinoma e 1 com cisto epidermóíde, localizados na região parasselar. Eles haviam sido tratados, em média, 3,8±3,2 anos antes, por cirurgia e radioterapia (6 casos) ou somente cirurgia (3 casos). Cinco pacientes eram do sexo feminino e a média de idade era de 24,3±18,8 anos. A avaliação consistiu na infusão endovenosa de TRH (200 mg), GnRH (100 mg) e insulina regular (0,1 UI Kg/peso), bem como na dosagem dos hormônios hipofisários antes (0) e após 20, 40, 60 e 80 minutos. Encontramos os seguintes resultados: (a) resposta deficitária do GH e do cortisol era todos pacientes; (b) 7/9 pacientes não tiveram respostas adequadas do FSH e 3/9 do L.H; (c) 4/9 tiveram respostas inadequadas da prolactina e 2/8 do TSH. Concluimos que: (a) o déficit de GH e cortisol são os mais frequentes nestes pacientes; (b) a lesão após radioterapia pode localizar-se tanto no hipotálamo quanto na hipófise ou, ainda, em ambos; (c) a sensibilidade das células hipofisárias e hipotalâmicas à irradiação é diferente de acordo com os hormônios que produzem; (d) é necessário o acompanhamento endocrinológico frequente dos pacientes submetidos a tratamento de tumores parasselares, a fim de detectar déficits hormonais tardios.Long term follow-up of patients submitted to treatment of paraselar tumours region is important for the detection of late therapeutic complications. In this study the authors conducted an evaluation of six patients with craniopharyngioma, one with germinoma, one with meningioma, and one epidermoid cyst. All above tumours were localized at paraselar region. Six out of nine patients had been treated both by surgery and by radiotherapy and the other three surgically only, on an average 3.8±3.2 years before this observation was carried out. Five patients were female with their ages average 24.3±18.8 years old. Evaluation consisted: in the first place, an intravenous infusion of thyrotropin-releasing hormone (TRH, 200 mg), gonadotropin-releasing hormone (GnRH, 100 mg), and insulin tolerance test (0,1 IU/Kg, regular insulin); and secondly, in measurements of pituitary hormones secretion at different time points - 0, 20,40, 60 and 80 minutes. We found both diminished response of growth hormone and Cortisol in all the patients. Seven out of nine patients did not have adequate response to follicle-stimulating hormone. Three out of nine responded unsatisfactory to luteinizing hormone. Four out of nine showed inadequate responses to prolactin as well as, two out of eight to thyrotropin. We concluded that: (a) growth hormone and Cortisol deficiency are the most frequent finding in these patients; (b) post-radiotherapy lesions can be located in the hypothalamus or pituitary, or even in both; (c) hypophsial and hypothalamic cell sensitivity to irradiation is different, according to their respective hormones; and (d) it is necessary a frequent endocrinologic follow-up of patients to detect late hormonal deficiences

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

The dynamic range of the upgraded surface-detector stations of AugerPrime

The detection of ultra-high-energy cosmic rays by means of giant detector arrays is often limited by the saturation of the recorded signals near the impact point of the shower core at the ground, where the particle density dramatically increases. The saturation affects in particular the highest energy events, worsening the systematic uncertainties in the reconstruction of the shower characteristics. The upgrade of the Pierre Auger Observatory, called AugerPrime, includes the installation of an 1-inch Small PhotoMultiplier Tube (SPMT) inside each water-Cherenkov station (WCD) of the surface detector array. The SPMT allows an unambiguous measurement of signals down to about 250m from the shower core, thus reducing the number of events featuring a saturated station to a negligible level. In addition, a 3.8m2 plastic scintillator (Scintillator Surface Detector, SSD) is installed on top of each WCD. The SSD is designed to match the WCD (with SPMT) dynamic range, providing a complementary measurement of the shower components up to the highest energies. In this work, the design and performances of the upgraded AugerPrime surface-detector stations in the extended dynamic range are described, highlighting the accuracy of the measurements. A first analysis employing the unsaturated signals in the event reconstruction is also presented

Investigating multiple elves and halos above strong lightning with the fluorescence detectors of the Pierre Auger Observatory

ELVES are being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, in the province of Mendoza (Argentina), the world’s largest facility for the study of ultra-high energy cosmic rays. This study exploits a dedicated trigger and extended readout. Since December 2020, this trigger has been extended to the three High levation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, allowing a study of ELVES from closer lightning. The high time resolution of the Auger telescopes allows us to upgrade reconstruction algorithms and to do detailed studies on multiple ELVES. The origin of multiple elves can be studied by analyzing the time difference and the amplitude ratio between flashes and comparing them with the properties of radio signals detected by the ENTLN lightning network since 2018. A fraction of multi-ELVES can also be interpreted as halos following ELVES. Halos are disc-shaped light transients emitted at 70-80 km altitudes, appearing at the center of the ELVES rings, due to the rearrangement of electric charges at the base of the ionosphere after a strong lightning event