Effect of the glucocorticoid receptor antagonist Org 34850 on fast and delayed feedback of corticosterone release

We investigated the effect of the glucocorticoid receptor (GR) antagonist Org 34850 on fast and delayed inhibition of corticosterone secretion in response to the synthetic glucocorticoid methylprednisolone (MPL). Male rats were implanted with a catheter in the right jugular vein, for blood sampling and MPL administration, and with an s.c. cannula for Org 34850 administration. All experiments were conducted at the diurnal hormonal peak in the late afternoon. Rats were connected to an automated sampling system and blood samples were collected every 5 or 10 min. Org 34850 (10 mg/kg, s.c.) or vehicle (5% mulgofen in saline) was injected at 1630 h; 30 min later, rats received an injection of MPL (500 μg/rat, i.v.) or saline (0.1 ml/rat). We found that an acute administration of MPL rapidly decreased the basal corticosterone secretion and this effect was not prevented by acute pretreatment with Org 34850. However, blockade of GR with Org 34850 prevented delayed inhibition of MPL on corticosterone secretion measured between 4 and 12 h after MPL administration. Our data suggest an involvement of GR in modulating delayed, but not fast, inhibition induced by MPL on basal corticosterone secretion

Constraint on the early Universe by relic gravitational waves: From pulsar timing observations

Recent pulsar timing observations by the Parkers Pulsar Timing Array and European Pulsar Timing Array teams obtained the constraint on the relic gravitational waves at the frequency $f_*=1/{\rm yr}$, which provides the opportunity to constrain $H_*$, the Hubble parameter when these waves crossed the horizon during inflation. In this paper, we investigate this constraint by considering the general scenario for the early Universe: we assume that the effective (average) equation-of-state $w$ before the big bang nucleosynthesis stage is a free parameter. In the standard hot big-bang scenario with $w=1/3$, we find that the current PPTA result follows a bound H_*\leq 1.15\times10^{-1}\mpl, and the EPTA result follows H_*\leq 6.92\times10^{-2}\mpl. We also find that these bounds become much tighter in the nonstandard scenarios with $w>1/3$. When $w=1$, the bounds become H_*\leq5.89\times10^{-3}\mpl for the current PPTA and H_*\leq3.39\times10^{-3}\mpl for the current EPTA. In contrast, in the nonstandard scenario with $w=0$, the bound becomes H_*\leq7.76\mpl for the current PPTA.Comment: 8 pages, 3 figures, 1 table, PRD in pres

Construction of time preference: an investigation of the role of elicitation method in experimental elicitation of time preference.

The idea of preference reversal and construction of preference is not new to literature in decision making. Indeed, several theories have been developed to explain it. (Lichtenstein and Slovic, 2006). The present paper considers heuristics activated in different elicitation procedures applied in time preference research. I show that activation of these rules in correspondence with different elicitation methods leads to observation of a particular pattern most frequently reported in time preference literature: hyperbolic discounting. In particular, I analyze two most diffused elicitation procedures, matching task and two variations of choice task in multiple price list format (MPL). In a series of experiments I demonstrate that matching task is characterized by choice of focal amounts and anchoring to previously reported amount. At the same time, choice in MPL format largely depends on the structure of the list from which the choice is made. I study two widely used structures of MPL choice task format: (a) MPL with nominal structure (Green et al, 1997), where choice alternatives correspond to the same nominal amounts that are available at different time horizons; (b) MPL with interest rate structure (Coller and Williams, 1999), in which monetary alternatives at each time horizon in consideration are constructed as increases corresponding to a fixed interest rate. Although these two elicitation structures activate similar decision processes they lead to observation of qualitatively different results that are in large part defined by the underlying structure of the list of alternatives. I show that matching task and MPL with nominal structure lead to observation of hyperbolic evidence, that could be of different kinds depending on the structure of MPL table. At the same time, elicitation with MPL with interest rate structure leads to observation of rather stable time preference that can be well approximated by exponential discounting.decision making; time preference; elicitation procedures

Construction of time preference: an investigation of the role of elicitation method in experimental elicitation of time preference.

The idea of preference reversal and construction of preference is not new to literature in decision making. Indeed, several theories have been developed to explain it. (Lichtenstein and Slovic, 2006). The present paper considers heuristics activated in different elicitation procedures applied in time preference research. I show that activation of these rules in correspondence with different elicitation methods leads to observation of a particular pattern most frequently reported in time preference literature: hyperbolic discounting. In particular, I analyze two most diffused elicitation procedures, matching task and two variations of choice task in multiple price list format (MPL). In a series of experiments I demonstrate that matching task is characterized by choice of focal amounts and anchoring to previously reported amount. At the same time, choice in MPL format largely depends on the structure of the list from which the choice is made. I study two widely used structures of MPL choice task format: (a) MPL with nominal structure (Green et al, 1997), where choice alternatives correspond to the same nominal amounts that are available at different time horizons; (b) MPL with interest rate structure (Coller and Williams, 1999), in which monetary alternatives at each time horizon in consideration are constructed as increases corresponding to a fixed interest rate. Although these two elicitation structures activate similar decision processes they lead to observation of qualitatively different results that are in large part defined by the underlying structure of the list of alternatives. I show that matching task and MPL with nominal structure lead to observation of hyperbolic evidence, that could be of different kinds depending on the structure of MPL table. At the same time, elicitation with MPL with interest rate structure leads to observation of rather stable time preference that can be well approximated by exponential discounting.

Regional and global hydrology and water resources issues: The role of international and national programs

This paper presents an overview of water resources issues in the context of world population growth, climate change, and variability, and provides examples of how these issues affect local and regional water policy concerns. Also discussed is the associated research of the international scientific community in regard to physically-based modeling of the hydrological cycle, with special focus on the Global Energy and Water cycle EXperiment (GEWEX) Programme. The critical role of precipitation measurements for climate model accuracy is emphasized, with a review of several satellite methods and strategies for improving precipitation measurements. Finally, the impact of semiarid regions on global hydrologic issues is underscored with a review of research conducted by SAHRA, the National Science Foundation Science and Technology Center dedicated to Sustainability of semi-Add Hydrology and Riparian Areas

Impact of histone H4 lysine 20 methylation on 53BP1 responses to chromosomal double strand breaks.

Recruitment of 53BP1 to chromatin flanking double strand breaks (DSBs) requires γH2AX/MDC1/RNF8-dependent ubiquitination of chromatin and interaction of 53BP1 with histone H4 methylated on lysine 20 (H4K20me). Several histone methyltransferases have been implicated in 53BP1 recruitment, but their quantitative contributions to the 53BP1 response are unclear. We have developed a multi-photon laser (MPL) system to target DSBs to subfemtoliter nuclear volumes and used this to mathematically model DSB response kinetics of MDC1 and of 53BP1. In contrast to MDC1, which revealed first order kinetics, the 53BP1 MPL-DSB response is best fitted by a Gompertz growth function. The 53BP1 MPL response shows the expected dependency on MDC1 and RNF8. We determined the impact of altered H4K20 methylation on 53BP1 MPL response kinetics in mouse embryonic fibroblasts (MEFs) lacking key H4K20 histone methyltransferases. This revealed no major requirement for the known H4K20 dimethylases Suv4-20h1 and Suv4-20h2 in 53BP1 recruitment or DSB repair function, but a key role for the H4K20 monomethylase, PR-SET7. The histone methyltransferase MMSET/WHSC1 has recently been implicated in 53BP1 DSB recruitment. We found that WHSC1 homozygous mutant MEFs reveal an alteration in balance of H4K20 methylation patterns; however, 53BP1 DSB responses in these cells appear normal

Inflation with TeV-scale gravity

Allowing for the possibility of large extra dimensions, the fundamental Planck scale $M$ could be anywhere in the range \TeV\lsim M\lsim \mpl, where \mpl=2.4\times 10^{18}\GeV is the four-dimensional Planck scale. If M\sim\TeV, quantum corrections would not destabilize the Higgs mass even if there were no supersymmetry. But we point out that supersymmetry must in fact be present, if there is an era of cosmological inflation, since during such an era the inflaton mass satisfies m\ll M^2/\mpl=10^{-15}(M/\TeV) and supersymmetry will be needed to protect it. If the inflation hypothesis is accepted, there is no reason to think that Nature has chosen the low value M\sim \TeV, however convenient that choice might have been for the next generation of collider experiments.Comment: 6 pages, to appear in PLB. v3 has Same conclusion stated more precisel

Magnetic Field Induced Charged Exciton Studies in a GaAs/Al(0.3)Ga(0.7)As Single Heterojunction

The magnetophotoluminescence (MPL) behavior of a GaAs/Al(0.3)Ga(0.7)As single heterojunction has been investigated to 60T. We observed negatively charged singlet and triplet exciton states that are formed at high magnetic fields beyond the nu=1 quantum Hall state. The variation of the charged exciton binding energies are in good agreement with theoretical predictions. The MPL transition intensities for these states showed intensity variations (maxima and minima) at the nu=1/3 and 1/5 fractional quantum Hall (FQH) state as a consequence of a large reduction of electron-hole screening at these filling factors.Comment: submitted to Phys. Rev. Let

Excited states of the free excitons in CuInSe2 single crystals

High-quality CuInSe2 single crystals were studied using polarization resolved photoluminescence (PL) and magnetophotoluminescence (MPL). The emission lines related to the first (n=2) excited states for the A and B free excitons were observed in the PL and MPL spectra at 1.0481 meV and 1.0516 meV, respectively. The spectral positions of these lines were used to estimate accurate values for the A and B exciton binding energies (8.5 meV and 8.4 meV, respectively), Bohr radii (7.5 nm), band gaps (E-g(A)=1.050 eV and E-g(B)=1.054 eV), and the static dielectric constant (11.3) assuming the hydrogenic model