26,362 research outputs found
Satisfiability of CTL* with constraints
We show that satisfiability for CTL* with equality-, order-, and
modulo-constraints over Z is decidable. Previously, decidability was only known
for certain fragments of CTL*, e.g., the existential and positive fragments and
EF.Comment: To appear at Concur 201
Do We Really Know that Oil Caused the Great Stagflation? A Monetary Alternative
This paper argues that major oil price increases were not nearly as essential a part of the causal mechanism that generated the stagflation of the 1970s as is often thought. There is neither a theoretical presumption that oil supply shocks are stagflationary nor robust empirical evidence for this view. In contrast, we show that monetary expansions and contractions can generate stagflation of realistic magnitude even in the absence of supply shocks. Furthermore, monetary fluctuations help to explain the historical movements of the prices of oil and other commodities, including the surge in the prices of industrial commodities that preceded the 1973/74 oil price increase. Thus, they can account for the striking coincidence of major oil price increases and worsening stagflation.
TRPC1 regulates calcium-activated chloride channels in salivary gland cells
Calcium-activated chloride channel (CaCC) plays an important role in modulating epithelial secretion. It has been suggested that in salivary tissues, sustained fluid secretion is dependent on Ca2+ influx that activates ion channels such as CaCC to initiate Cl- efflux. However direct evidence as well as the molecular identity of the Ca2+ channel responsible for activating CaCC in salivary tissues is not yet identified. Here we provide evidence that in human salivary cells, an outward rectifying Cl- current was activated by increasing [Ca2+]i, which was inhibited by the addition of pharmacological agents niflumic acid (NFA), an antagonist of CaCC, or T16Ainh-A01, a specific TMEM16a inhibitor. Addition of thapsigargin (Tg), that induces store-depletion and activates TRPC1-mediated Ca2+ entry, potentiated the Cl- current, which was inhibited by the addition of a non-specific TRPC channel blocker SKF96365 or removal of external Ca2+. Stimulation with Tg also increased plasma membrane expression of TMEM16a protein, which was also dependent on Ca2+ entry. Importantly, in salivary cells, TRPC1 silencing, but not that of TRPC3, inhibited CaCC especially upon store depletion. Moreover, primary acinar cells isolated from submandibular gland also showed outward rectifying Cl- currents upon increasing [Ca2+]i. These Cl- currents were again potentiated with the addition of Tg, but inhibited in the presence of T16Ainh-A01. Finally, acinar cells isolated from the submandibular glands of TRPC1 knockout mice showed significant inhibition of the outward Cl- currents without decreasing TMEM16a expression. Together the data suggests that Ca2+ entry via the TRPC1 channels is essential for the activation of CaCC.Fil: Sun, Yuyang. University Of North Dakota; Estados UnidosFil: Birnbaumer, Lutz. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Singh, Brij B.. University Of North Dakota; Estados Unido
From meson- and photon-nucleon scattering to vector mesons in nuclear matter
We present a relativistic and unitary approach to pion- and photon-nucleon
scattering taking into account the , , , ,
, and channels. Our scheme dynamically
generates the s- and d-wave nucleon resonances N(1535), N(1650), N(1520) and
N(1700) and isobar resonances and in terms of
quasi-local two-body interaction terms. We obtain a fair description of the
experimental data relevant for slow vector-meson propagation in nuclear matter.
The s-wave - and -meson nucleon scattering amplitudes, which
define the leading density modification of the - and -meson
spectral functions in nuclear matter, are predicted.Comment: 6 pages, 1 figure; contribution to the Int. Workshop XXX on Gross
Properties of Nuclei and Nuclear Excitations: Ultrarelativistic Heavy Ion
Collisions, Hirschegg, Jan. 13-19, 200
Operational integrator
System operates in the nonreturn-to-zero mode, maintaining the increased bit density capability of this mode but with much higher noise immunity than conventional schemes offer. This integrator performs a mathematical integrating function on inputs from 100 Hz through 100 MHz
The Impact of Employer-Provided Health Insurance on Dynamic Employment Transitions
We estimate the impact of employer-provided health insurance (EPHI) on the job mobility of males over time using a dynamic empirical model that accounts for unobserved heterogeneity. Previous studies of job-lock reach different conclusions about possible distortions in labor mobility stemming from an employment-based health insurance system: a few authors find no evidence of job-lock, while most find reductions in the mobility of insured workers of between 20 and 40%. WE use data from the National Longitudinal Survey of Youth which describes the health insurance an individual holds, as well as whether he is offered insurance by his employer. This additional information allows us to model the latent individual characteristics that are correlated with the offer of EPHI, the acceptance of EPHI, and employment transitions. Our results provide an estimate of job-lock unbiased through correlation with positive job characteristics and individual specific turnover propensity. We find no evidence of job-lock among married males, and produce small estimates of job-lock among unmarried males of between 10 and 15%.
Saturation from nuclear pion dynamics
We construct an equation-of-state for nuclear matter based on the chiral
Lagrangian. The relevant scales are discussed and an effective chiral power
expansion scheme, which is constructed to work around the nuclear saturation
density, is presented. A realistic equation-of-state is obtained by adjusting
one free parameter, when the leading and subleading terms in the expansion are
included. The saturation mechanism is due to correlations induced by the
one-pion-exchange interaction. Furthermore, we find a substantial deviation
from the Fermi-gas estimate of the quark condensate in nuclear matter already
at the saturation density.Comment: revised version, with minor corrections, 13 pages, 3 Postscript
figure
- …
