2,034 research outputs found
Global imbalances and current account imbalances.
As the global economy gradually recovers from the severe recession, the possible risks of unsustainable global imbalances are receiving renewed attention. In assessing global imbalances, it is important to avoid excessively focusing on current account imbalances per se. Rather, the focus should be on the root causes of the imbalance and whether they may become sources of unsustainable financial imbalances. The recent financial crisis, as well as Japanâs past experience in the 1980s, highlight the importance of information which cannot necessarily be obtained from current account statistics. Unsustainable financial imbalances can be better captured through information such as the build-up of leverage, gross cross-border capital flows, risk pricing in financial markets, and the extent of currency and maturity mismatches in the financial system. Through careful assessment of such elements central banks and other authorities will be able to assess whether current account imbalances are a reflection of the build-up of domestic financial imbalances. In formulating macroeconomic policy, the traditional emphasis was to ensure domestic stability or to put oneâs house in order. However, with the deepening of globalisation, the simple sum of each countryâs policy action may not necessarily achieve an optimal outcome at the global level. It has become ever more important for countries to review the spillover effects of their policies which will also reverberate back to each country through economic and financial interlinkages.
FamĂlia defensiva de peptĂdeos antimicrobianos em Urochloa.
O capim-braquiĂĄria Ă© muito utilizado no Brasil, principalmente no cerrado, como forrageira devido a sua alta adaptabilidade a variados solos, como solos ĂĄcidos ou pobres em nutrientes; e apresenta alta cobertura e produção de biomassa. Os peptĂdeos antimicrobianos sĂŁo molĂ©culas proteicas pequenas produzidas por todos os seres vivos como parte do sistema imune inato para combater infecçÔes e patĂłgenos. PeptĂdeos antimicrobianos vegetais possuem um amplo espectro de atividades antimicrobianas contra fitopatĂłgenos e a grande maioria deles Ă© ativa contra fungos, enquanto alguns sĂŁo inibidores de bactĂ©rias e insetos herbĂvoros. Deste modo, o objetivo deste trabalho foi verificar e identificar a presença de peptĂdeos antimicrobianos da famĂlia das defensinas em U. decumbens por meio da comparação entre as sequĂȘncias do transcriptoma da planta contra as sequĂȘncias de aminoĂĄcidos de peptĂdeos antimicrobianos. O transcriptoma da planta foi fornecido pela EMBRAPA Gado de Corte (Campo Grande, MS), obtido pela extração de RNA de plantas expostas a condiçÔes de estresse (com alumĂnio) e sem estresse (sem alumĂnio). As sequĂȘncias dos peptĂdeos antimicrobianos foram baixadas do banco de dados online CAMP e foram formatadas em FASTA em um banco local no computador da FCBA, UFGD. Foi utilizado o blast local para fazer o alinhamento entre os 164.920 transcritos Ășnicos da U. decumbens e as 5.906 sequĂȘncias de peptĂdeos antimicrobianos. Deste alinhamento obteve-se 3.161 similaridades com 251 peptĂdeos diferentes. Para a anĂĄlise dos resultados utilizou-se o MySQL, separando-os em famĂlias de acordo com a classificação do banco de dados CAMP e selecionando um grupo amostral para a construção das ĂĄrvores filogenĂ©ticas. A partir desta anĂĄlise, obteve-se 261 similaridades com 52 peptĂdeos diferentes dentro da famĂlia das defensinas. A maioria dos peptĂdeos antimicrobianos identificados possui atividade antifĂșngica ou antimicrobiana, e sĂŁo de origem vegetal o que condiz com os transcritos da gramĂnea
A new half-metallic ferromagnet K2Cr8O16 predicted by an ab-initio electronic structure calculation
The first-principles electronic structure calculation is carried out to predict that a chromium oxide K2Cr8O16 with the hollandite-type crystal structure should be a new half-metallic ferromagnet. We compare our results with recent experimental data which indicate the ferromagnetic-metal to ferromagnetic-insulator transition at T ⌠90 K, as well as the paramagnetic-metal to ferromagnetic-metal transition at T ⌠180 K. Based on the calculated electronic structures, we argue that the double-exchange mechanism is responsible for the observed saturated ferromagnetism and the formation of the incommensurate, long-wavelength density wave of spinless fermions caused by the Fermi-surface nesting may be the origin of the opening of the charge gap.Ministry of Education, Culture, Sports, Science and Technology of Japa
Bessel bridges decomposition with varying dimension. Applications to finance
We consider a class of stochastic processes containing the classical and
well-studied class of Squared Bessel processes. Our model, however, allows the
dimension be a function of the time. We first give some classical results in a
larger context where a time-varying drift term can be added. Then in the
non-drifted case we extend many results already proven in the case of classical
Bessel processes to our context. Our deepest result is a decomposition of the
Bridge process associated to this generalized squared Bessel process, much
similar to the much celebrated result of J. Pitman and M. Yor. On a more
practical point of view, we give a methodology to compute the Laplace transform
of additive functionals of our process and the associated bridge. This permits
in particular to get directly access to the joint distribution of the value at
t of the process and its integral. We finally give some financial applications
to illustrate the panel of applications of our results
AC resistivity of d-wave ceramic superconductors
We model d-wave ceramic superconductors with a three-dimensional lattice of
randomly distributed Josephson junctions with finite self-inductance. The
linear and nonlinear ac resistivity of the d-wave ceramic superconductors is
obtained as function of temperature by solving the corresponding Langevin
dynamical equations. We find that the linear ac resistivity remains finite at
the temperature where the third harmonics of resistivity has a peak. The
current amplitude dependence of the nonlinear resistivity at the peak position
is found to be a power law. These results agree qualitatively with experiments.
We also show that the peak of the nonlinear resistivity is related to the onset
of the paramagnetic Meissner effect which occurs at the crossover temperature
, which is above the chiral glass transition temperature .Comment: 7 eps figures, Phys. Rev. B (in press
Reducing nonideal to ideal coupling in random matrix description of chaotic scattering: Application to the time-delay problem
We write explicitly a transformation of the scattering phases reducing the
problem of quantum chaotic scattering for systems with M statistically
equivalent channels at nonideal coupling to that for ideal coupling. Unfolding
the phases by their local density leads to universality of their local
fluctuations for large M. A relation between the partial time delays and
diagonal matrix elements of the Wigner-Smith matrix is revealed for ideal
coupling. This helped us in deriving the joint probability distribution of
partial time delays and the distribution of the Wigner time delay.Comment: 4 pages, revtex, no figures; published versio
Stability of the Magnetopause of Disk-Accreting Rotating Stars
We discuss three modes of oscillation of accretion disks around rotating
magnetized neutron stars which may explain the separations of the kilo-Hertz
quasi periodic oscillations (QPO) seen in low mass X-ray binaries. The
existence of these compressible, non-barotropic magnetohydrodynamic (MHD) modes
requires that there be a maximum in the angular velocity of
the accreting material larger than the angular velocity of the star ,
and that the fluid is in approximately circular motion near this maximum rather
than moving rapidly towards the star or out of the disk plane into funnel
flows. Our MHD simulations show this type of flow and profile.
The first mode is a Rossby wave instability (RWI) mode which is radially
trapped in the vicinity of the maximum of a key function at
. The real part of the angular frequency of the mode is
, where is the azimuthal mode number.
The second mode, is a mode driven by the rotating, non-axisymmetric component
of the star's magnetic field. It has an angular frequency equal to the star's
angular rotation rate . This mode is strongly excited near the radius
of the Lindblad resonance which is slightly outside of . The third mode
arises naturally from the interaction of flow perturbation with the rotating
non-axisymmetric component of the star's magnetic field. It has an angular
frequency . We suggest that the first mode with is associated
with the upper QPO frequency, ; that the nonlinear interaction of the
first and second modes gives the lower QPO frequency, ;
and that the nonlinear interaction of the first and third modes gives the lower
QPO frequency , where .Comment: 10 pages, 7 figure
In vivo Ca2+ dynamics induced by Ca2+ injection in individual rat skeletal muscle fibers
Citation: Wakizaka, M., Eshima, H., Tanaka, Y., Shirakawa, H., Poole, D. C., & Kano, Y. (2017). In vivo Ca2+ dynamics induced by Ca2+ injection in individual rat skeletal muscle fibers. Physiological Reports, 5(5), 10. doi:10.14814/phy2.13180In contrast to cardiomyocytes, store overload-induced calcium ion (Ca2+) release (SOICR) is not considered to constitute a primary Ca2+ releasing system from the sarcoplasmic reticulum (SR) in skeletal muscle myocytes. In the latter, voltage-induced Ca2+ release (VICR) is regarded as the dominant mechanism facilitating contractions. Any role of the SOICR in the regulation of cytoplasmic Ca2+ concentration ([Ca2+](i)) and its dynamics in skeletal muscle in vivo remains poorly understood. By means of in vivo single fiber Ca2+ microinjections combined with bioimaging techniques, we tested the hypothesis that the [Ca2+](i) dynamics following Ca2+ injection would be amplified and fiber contraction facilitated by SOICR. The circulation-intact spinotrapezius muscle of adult male Wistar rats (n = 34) was exteriorized and loaded with Fura-2 AM to monitor [Ca2+](i) dynamics. Groups of rats underwent the following treatments: (1) 0.02, 0.2, and 2.0 mmol/L Ca2+ injections, (2) 2.0 mmol/L Ca2+ with inhibition of ryanodine receptors (RyR) by dantrolene sodium (DAN), and (3) 2.0 mmol/L Ca2+ with inhibition of SR Ca2+ ATPase (SERCA) by cyclopiazonic acid (CPA). A quantity of 0.02 mmol/L Ca2+ injection yielded no detectable response, whereas peak evoked [Ca2+](i) increased 9.9 +/- 1.8% above baseline for 0.2 mmol/L and 23.8 c 4.3% (P < 0.05) for 2.0 mmol/L Ca2+ injections. The peak [Ca2+](i) in response to 2.0 mmol/L Ca2+ injection was largely abolished by DAN and CPA (-85.8%, -71.0%, respectively, both P < 0.05 vs. unblocked) supporting dependence of the [Ca2+](i) dynamics on Ca2+ released by SOICR rather than injected Ca2+ itself. Thus, this investigation demonstrates the presence of a robust SR-evoked SOICR operant in skeletal muscle in vivo
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