1,293 research outputs found
Π‘ΠΊΠ°ΡΠ½Ρ ΠΈ ΠΏΠΎΡΠ»Π΅ΡΠΊΠ°ΡΠ½ΠΎΠ²ΡΠ΅ ΠΌΠ΅ΡΠ°ΡΠΎΠΌΠ°ΡΠΈΡΡ ΡΠ΅Π²Π΅ΡΠ½ΠΎΠΉ ΡΠ°ΡΡΠΈ Π‘Π°ΡΠ°Π»ΠΈΠ½ΡΠΊΠΎΠ³ΠΎ ΡΡΠ΄Π½ΠΎΠ³ΠΎ ΠΏΠΎΠ»Ρ
Π ΡΡΠ°ΡΡΠ΅ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΡΡΡ Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΏΠΎΠ·ΠΈΡΠΈΡ ΡΠΊΠ°ΡΠ½ΠΎΠ² ΠΈ ΠΏΠΎΡΠ»Π΅ΡΠΊΠ°ΡΠ½ΠΎΠ²ΡΡ
ΠΌΠ΅ΡΠ°ΡΠΎΠΌΠ°ΡΠΈΡΠΎΠ². ΠΠ°ΡΡΡΡ ΠΊΡΠ°ΡΠΊΠΈΠ΅ ΠΏΠ΅ΡΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅, Π³Π΅ΠΎΡ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΈ ΡΡΡΠ°Π½Π°Π²Π»ΠΈΠ²Π°Π΅ΡΡΡ ΠΈΡ
Π³Π΅Π½Π΅ΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΠ²ΡΠ·Ρ Ρ Π±ΠΎΠ»Π΅Π΅ ΠΌΠΎΠ»ΠΎΠ΄ΠΎΠΉ, Π½Π΅Π·ΠΎΠ»ΠΎΡΠΎΠ½ΠΎΡΠ½ΠΎΠΉ ΠΈΠ½ΡΡΡΠ·ΠΈΠ΅ΠΉ Π³ΡΠ°Π½ΠΈΡ-Π³ΡΠ°Π½ΠΎΠ΄ΠΈΠΎΡΠΈΡΠΎΠ²ΠΎΠ³ΠΎ ΡΠΎΡΡΠ°Π²Π°
Models and techniques for hotel revenue management using a rolling horizon.
This paper studies decision rules for accepting reservations for stays in a hotel based on
deterministic and stochastic mathematical programming techniques. Booking control strategies
are constructed that include ideas for nesting, booking limits and bid prices. We allow for
multiple day stays. Instead of optimizing a decision period consisting of a fixed set of
target booking days, we simultaneously optimize the complete range of target booking dates
that are open for booking at the moment of optimization. This yields a rolling horizon of
overlapping decision periods, which will conveniently capture the effects of overlapping stays
Sub-Alfvenic Non-Ideal MHD Turbulence Simulations with Ambipolar Diffusion: I. Turbulence Statistics
Most numerical investigations on the role of magnetic fields in turbulent
molecular clouds (MCs) are based on ideal magneto-hydrodynamics (MHD). However,
MCs are weakly ionized, so that the time scale required for the magnetic field
to diffuse through the neutral component of the plasma by ambipolar diffusion
(AD) can be comparable to the dynamical time scale. We have performed a series
of 256^3 and 512^3 simulations on supersonic but sub-Alfvenic turbulent systems
with AD using the Heavy-Ion Approximation developed in Li, McKee, & Klein
(2006). Our calculations are based on the assumption that the number of ions is
conserved, but we show that these results approximately apply to the case of
time-dependent ionization in molecular clouds as well. Convergence studies
allow us to determine the optimal value of the ionization mass fraction when
using the heavy-ion approximation for low Mach number, sub-Alfvenic turbulent
systems. We find that ambipolar diffusion steepens the velocity and magnetic
power spectra compared to the ideal MHD case. Changes in the density PDF, total
magnetic energy, and ionization fraction are determined as a function of the AD
Reynolds number. The power spectra for the neutral gas properties of a strongly
magnetized medium with a low AD Reynolds number are similar to those for a
weakly magnetized medium; in particular, the power spectrum of the neutral
velocity is close to that for Burgers turbulence.Comment: 37 pages, 11 figures, 4 table
Alcohol Dysregulates Corticotropin-Releasing-Hormone (CRH) Promoter Activity by Interfering with the Negative Glucocorticoid Response Element (nGRE)
EtOH exposure in male rats increases corticotropin-releasing hormone (CRH) mRNA in the paraventricular nucleus of the hypothalamus (PVN), a brain region responsible for coordinating stress and anxiety responses. In this study we identified the molecular mechanisms involved in mediating these effects by examining the direct effects of EtOH on CRH promoter activity in a neuronal cell line derived from the PVN (IVB). In addition, we investigated the potential interactions of EtOH and glucocorticoids on the CRH promoter by concomitantly treating cells with EtOH and the glucocorticoid receptor (GR) antagonist RU486, and by sequentially deleting GR binding sites within glucocorticoid response element (GRE) on the CRH promoter. Cells were transiently transfected with a firefly luciferase reporter construct containing 2.5 kb of the rat wild type (WT) or mutated CRH promoter. Our results showed that EtOH treatment induced a biphasic response in CRH promoter activity. EtOH exposure for 0.5 h significantly decreased promoter activity compared to vehicle treated controls, whereas promoter activity was significantly increased after 2.0 h of EtOH exposure. Treatment with RU486, or deletion of the GR binding sites 1 and 2 within the GRE, abolished the EtOH-induced increase in the promoter activity, however did not affect EtOH-induced decrease in CRH promoter activity at an earlier time point. Overall, our data suggest that alcohol exposure directly regulates CRH promoter activity by interfering with the normal feedback mechanisms of glucocorticoids mediated by GR signaling at the GRE site of the CRH promoter
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