28,303 research outputs found
The Incidence of Reserve Requirements in Brazil: Do Bank Stockholders Share the Burden?
There is consensus in the economic literature that the reserve requirements are a tax levied upon financial intermediation, yet the incidence of the tax remains controversial. In this paper, we test whether changes in reserve requirements in Brazil impact the stock returns of the financial system distinctly from the rest of the economy. We find evidence that Brazilian bank stock returns were affected by changes in reserve requirements on both time deposits and transaction accounts, which implies that the tax burden of required reserves was not fully passed through to banks' borrowers or clients. Stock returns of non-financial firms were also affected by these changes, suggesting that in some cases, reserve requirements on time deposits and transaction accounts served as a non-neutral instrument of monetary or fiscal policy in Brazil.
Continuity properties of a factor of Markov chains
Starting from a Markov chain with a finite alphabet, we consider the chain
obtained when all but one symbol are undistinguishable for the practitioner. We
study necessary and sufficient conditions for this chain to have continuous
transition probabilities with respect to the past
Quantum statistical correlations in thermal field theories: boundary effective theory
We show that the one-loop effective action at finite temperature for a scalar
field with quartic interaction has the same renormalized expression as at zero
temperature if written in terms of a certain classical field , and if
we trade free propagators at zero temperature for their finite-temperature
counterparts. The result follows if we write the partition function as an
integral over field eigenstates (boundary fields) of the density matrix element
in the functional Schr\"{o}dinger field-representation, and perform a
semiclassical expansion in two steps: first, we integrate around the
saddle-point for fixed boundary fields, which is the classical field ,
a functional of the boundary fields; then, we perform a saddle-point
integration over the boundary fields, whose correlations characterize the
thermal properties of the system. This procedure provides a
dimensionally-reduced effective theory for the thermal system. We calculate the
two-point correlation as an example.Comment: 13 pages, 1 figur
Protocolo modificado para extração de DNA do gênero Pestalotiopsis.
Objetivou-se com este trabalho modificar o protocolo de extração de DNA do gênero Pestalotiopsis. Foram obtidos 200 mg de micélio de 11 isolados de Pestalotiopsis sp. O protocolo de extração proposto por Joshi (2009) foi modificado e testado retirando-se o fenol no processo de desproteinização do DNA. A quantidade de DNA genômico extraído foi quantificada em fotodocumentador e a qualidade do DNA final foi avaliada em gel 0,9% de agarose e em reações de marcadores RAPD. A metodologia sem o emprego do fenol proporcionou quantidade satisfatória (32,55 a 49,92 ng/µL) e pureza de DNA para caracterização molecular do fungo. O protocolo modificado, portanto, pode ser utilizado para extrair DNA do gênero Pestalotiopsis com eficiência do método e segurança para os usuários
SPIDER X - Environmental effects in central and satellite early-type galaxies through the stellar fossil record
A detailed analysis of how environment affects the star formation history of
early-type galaxies (ETGs) is undertaken via high signal to noise ratio stacked
spectra obtained from a sample of 20,977 ETGs (morphologically selected) from
the SDSS-based SPIDER survey. Two major parameters are considered for the
study: the central velocity dispersion (sigma), which relates to local drivers
of star formation, and the mass of the host halo, which relates to
environment-related effects. In addition, we separate the sample between
centrals (the most massive galaxy in a halo) and satellites. We derive trends
of age, metallicity, and [alpha/Fe] enhancement, with sigma. We confirm that
the major driver of stellar population properties in ETGs is velocity
dispersion, with a second-order effect associated to the central/satellite
nature of the galaxy. No environmental dependence is detected for satellite
ETGs, except at low sigma - where satellites in groups or in the outskirts of
clusters tend to be younger than those in the central regions of clusters. In
contrast, the trends for centrals show a significant dependence on halo mass.
Central ETGs in groups (i.e. with a halo mass >10^12.5 M_Sun) have younger
ages, lower [alpha/Fe], and higher internal reddening, than "isolated" systems
(i.e. centrals residing in low-mass, <10^12.5 M_Sun, halos). Our findings imply
that central ETGs in groups formed their stellar component over longer time
scales than "isolated" centrals, mainly because of gas-rich interactions with
their companion galaxies.Comment: 22 pages, 19 figures, accepted for publication in MNRA
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