3,984 research outputs found
Portfolio Allocation, Income Uncertainty and Households' Flight from Risk
Analysing the US Panel Study of Income Dynamics, we present a new empirical method to investigate the extent to which households reduce their financial risk exposure when confronted with background risk. Our novel modelling approach - termed a deflated fractional ordered probit model - quantifies how the overall asset composition in a portfolio adjusts with background risk, and is unique in recovering for, any given risky asset class, the shares that are reallocated to a safer asset category. Background risk exerts a significant impact on household portfolios, resulting in a 'flight from risk', away from riskier to safer assets
Financial expectations and household consumption : does middle inflation matter?
Using British panel data, we explore the Finding that households often expect their financial position to remain unchanged compared to other alternatives, using a generalised middle inflated ordered probit (GMIOP) model. In doing so we account for the tendency of individuals to choose ‘neutral’ responses when faced with attitudinal and opinion-based questions, which are a common feature of survey data. Our empirical analysis strongly supports the use of a GMIOP model to account for this response pattern. Expectations indices based on competing discrete choice models are then exploited to explore the role that financial expectations play in driving the consumption of different types of durable goods and the amount of expenditure undertaken. Whilst financial optimism is significantly associated with consumption, indices which fail to take into account middle-inflation are found to overestimate the impact of financial expectations
Accurate exchange-correlation energies for the warm dense electron gas
Density matrix quantum Monte Carlo (DMQMC) is used to sample exact-on-average
-body density matrices for uniform electron gas systems of up to 10
matrix elements via a stochastic solution of the Bloch equation. The results of
these calculations resolve a current debate over the accuracy of the data used
to parametrize finite-temperature density functionals. Exchange-correlation
energies calculated using the real-space restricted path-integral formalism and
the -space configuration path-integral formalism disagree by up to
\% at certain reduced temperatures and densities . Our calculations confirm the accuracy of the configuration
path-integral Monte Carlo results available at high density and bridge the gap
to lower densities, providing trustworthy data in the regime typical of
planetary interiors and solids subject to laser irradiation. We demonstrate
that DMQMC can calculate free energies directly and present exact free energies
for and .Comment: Accepted version: added free energy data and restructured text. Now
includes supplementary materia
Small molecule induced reactivation of mutant p53 in cancer cells
The p53 cancer mutant Y220C is an excellent paradigm for rescuing the function of conformationally unstable p53 mutants because it has a unique surface crevice that can be targeted by small-molecule stabilizers. Here, we have identified a compound, PK7088, which is active in vitro: PK7088 bound to the mutant with a dissociation constant of 140 μM and raised its melting temperature, and we have determined the binding mode of a close structural analogue by X-ray crystallography. We showed that PK7088 is biologically active in cancer cells carrying the Y220C mutant by a battery of tests. PK7088 increased the amount of folded mutant protein with wild-type conformation, as monitored by immunofluorescence, and restored its transcriptional functions. It induced p53-Y220C-dependent growth inhibition, cell-cycle arrest and apoptosis. Most notably, PK7088 increased the expression levels of p21 and the proapoptotic NOXA protein. PK7088 worked synergistically with Nutlin-3 on up-regulating p21 expression, whereas Nutlin-3 on its own had no effect, consistent with its mechanism of action. PK7088 also restored non-transcriptional apoptotic functions of p53 by triggering nuclear export of BAX to the mitochondria. We suggest a set of criteria for assigning activation of p53
In vivo localization at the cellular level of stilbene fluorescence induced by Plasmopara viticola in grapevine leaves
Accurate localization of phytoalexins is a key for better understanding their role. This work aims to localize stilbenes, the main phytoalexins of grapevine. The cellular localization of stilbene fluorescence induced by Plasmopara viticola, the agent of downy mildew, was determined in grapevine leaves of very susceptible, susceptible, and partially resistant genotypes during infection. Laser scanning confocal microscopy and microspectrofluorimetry were used to acquire UV-excited autofluorescence three-dimensional images and spectra of grapevine leaves 5–6 days after inoculation. This noninvasive technique of investigation in vivo was completed with in vitro spectrofluorimetric studies on pure stilbenes as their fluorescence is largely affected by the physicochemical environment in various leaf compartments. Viscosity was the major physicochemical factor influencing stilbene fluorescence intensity, modifying fluorescence yield by more than two orders of magnitude. Striking differences in the localization of stilbene fluorescence induced by P. viticola were observed between the different genotypes. All inoculated genotypes displayed stilbene fluorescence in cell walls of guard cells and periclinal cell walls of epidermal cells. Higher fluorescence intensity was observed in guard-cell walls than in any other compartment due to increased local viscosity. In addition stilbene fluorescence was found in epidermal cell vacuoles of the susceptible genotype and in the infected spongy parenchyma of the partially resistant genotype. The very susceptible genotype was devoid of fluorescence both in the epidermal vacuoles and the mesophyll. This strongly suggests that the resistance of grapevine leaves to P. viticola is correlated with the pattern of localization of induced stilbenes in host tissues
Cytosolic Phospholipase A2α and Eicosanoids Regulate Expression of Genes in Macrophages Involved in Host Defense and Inflammation
Acknowledgments: We thank Dr. Robert Barkley and Charis Uhlson for mass spectrometry analysis. Funding: This work was supported by grants from the National Institutes of Health HL34303 (to C.C.L., R.C.M. and D.L.B), DK54741 (to J.V.B.), GM5322 (to D.L.W.) and the Wellcome Trust (to N.A.R.G. and G.D.B.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Unequal relationships in high and low power distance societies: a comparative study of tutor - student role relations in Britain and China
This study investigated people's conceptions of an unequal role relationship in two different types of society: a high power distance society and a low power distance society. The study focuses on the role relationship of tutor and student. British and Chinese tutors and postgraduate students completed a questionnaire that probed their conceptions of degrees of power differential and social distance/closeness in this role relationship. ANOVA results yielded a significant nationality effect for both aspects. Chinese respondents judged the relationship to be closer and to have a greater power differential than did British respondents. Written comments on the questionnaire and interviews with 9 Chinese academics who had experienced both British and Chinese academic environments supported the statistical findings and indicated that there are fundamental ideological differences associated with the differing conceptions. The results are discussed in relation to Western and Asian concepts of leadership and differing perspectives on the compatibility/incompatibility of power and distance/closeness
Multi-wavelength INTEGRAL NEtwork (MINE) observations of the microquasar GRS 1915+105
We present the international collaboration MINE (Multi-lambda Integral
NEtwork) aimed at conducting multi-wavelength observations of X-ray binaries
and microquasars simultaneously with the INTEGRAL gamma-ray satellite. We will
focus on the 2003 March-April campaign of observations of the peculiar
microquasar GRS 1915+105 gathering radio, IR and X-ray data. The source was
observed 3 times in the plateau state, before and after a major radio and X-ray
flare. It showed strong steady optically thick radio emission corresponding to
powerful compact jets resolved in the radio images, bright near-infrared
emission, a strong QPO at 2.5 Hz in the X-rays and a power law dominated
spectrum without cutoff in the 3-300 keV range. We compare the different
observations, their multi-wavelength light curves, including JEM-X, ISGRI and
SPI, and the parameters deduced from fitting the spectra obtained with these
instruments on board INTEGRAL.Comment: 4 pages, 9 fig., Proc. of the 5th INTEGRAL Workshop (Feb. 16-20
2004), to be published by ES
Simultaneous multi-wavelength observations of microquasars (the MINE collaboration)
We present the international collaboration MINE (Multi-lambda INTEGRAL
NEtwork) aimed at conducting multi-wavelength observations of microquasars
simultaneously with the INTEGRAL satellite. The first results on GRS 1915+105
are encouraging and those to come should help us to understand the physics of
the accretion and ejection phenomena around a compact object.Comment: 2 p, 3 fig., proc. of the IAU Coll. 194, ``Compact Binaries in the
Galaxy and Beyond'', Nov. 2003, La Paz, Mexico, to be published in the Conf.
Series of Revista Mexicana de Astronomia y Astrofisica, Eds. G. Tovmassian &
E. Sio
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