Why Are Prices Sticky? The Dynamics of Wholesale Gasoline Prices

The menu-cost interpretation of sticky prices implies that the probability of a price change should depend on the past history of prices and fundamentals only through the gap between the current price and the frictionless price. We find that this prediction is broadly consistent with the behavior of 9 Philadelphia gasoline wholesalers. We nevertheless reject the menu-cost model as a literal description of these firms' behavior, arguing instead that price stickiness arises from strategic considerations of how customers and competitors will react to price changes.

Using Predictive Scoring Systems for Asthma Exacerbations Could Help Safely Conserve Resources During the COVID-19 Pandemic

Further studies evaluating the usefulness of mPIS for predicting outcomes in pediatric patients who are experiencing asthma exacerbations would also be beneficial during these times. These benefits could easily expand beyond the pediatric asthma population to all age groups and other patients with exacerbation-prone respiratory diseases, such as cystic fibrosis and COPD. These and other predictive tools could help us safely conserve respiratory health care resources and give the best care we can to our patients as we continue to adapt to the pandemicDr. Davis is funded by the NIH and the Indiana Clinical and Translational Science Institute and also a patent holder for Optate and co-founder of Airbase Breathing Compan

Tissue factor expression, regulation, and signaling in human airway cells

Rationale: Tissue Factor (TF) is a transmembrane glycoprotein that canonically functions as the initiator of the coagulation cascade. Increased levels of TF have been associated with inflammatory airway diseases. Since lipopolysaccharide (LPS) is known to elicit and inflammatory response in airway epithelium, we hypothesized that airway epithelial cells release TF when exposed to LPS. Since TF aids in local wound healing, we also hypothesized that inhibition of TF would decrease NHBE growth. The specific aim of this work was to evaluate the effects of LPS exposure on TF production and release from airway epithelia and determine the signaling pathways involved. A secondary aim was to evaluate the effects of TF inhibition on NHBE growth. Methods: Normal human bronchial epithelial cells were grown in submerged cell culture and exposed to LPS as well as several intracellular signaling pathway agonist and inhibitors. Measurements: Tissue Factor mRNA and protein were measured in culture media and cell lysate by reverse-transcriptase polymerize chain reaction and enzyme-linked immunosorbent assay, respectively. Signaling pathways were evaluated using selective agonists and inhibitors. Main results: TF protein levels increased nearly two-fold in cell media after exposure to LPS (p \u3c 0.01). This did not occur in the presence of an MEK/ERK inhibitor (PD98059) or a SMAD inhibitor (SB431542). TF protein levels also increased nearly ten-fold in the presence of TGF-beta (p \u3c 0.05). mRNA of TF and TGF-beta was not altered by LPS or TGF-beta exposure. NHBE grown in the presence of Tissue Factor Pathway Inhibitor grew significantly slower than those grown in standard media (P \u3c 0.05). Conclusions: NHBE release TF when exposed to LPS. This phenomenon is post-translational and may be mediated by an autocrine mechanism involving MEK/ERK signaling that increases TGF-beta which then leads to the release of TF. Our data suggest that this airway epithelium release of TF serves as a local repair function

7-Tetrahydrobiopterin is an uncoupled cofactor for rat hepatic phenylalanine hydroxylase

AbstractRat hepatic phenylalanine hydroxylase requires both a tetrahydropterin cofactor and molecular oxygen to convert phenylalanine to tyrosine. During the physiological hydroxylation, a single mol of the natural cofactor, tetrahydrobiopterin, is oxidized for each mol of phenylalanine converted to tyrosine. Artificial conditions have been devised in which the oxidation of the tetrahydropterin is uncoupled from the hydroxylation of the aromatic amino acid substrate. Recently, an isomer of tetrahydrobiopterin, 7-tetrahydrobiopterin, has been isolated from the urine of certain mildly hyperphenylalaninemic children. We report in this communication that 7-tetrahydrobiopterin may be an inefficient cofactor for phenylalanine hydroxylase because, in vitro, the phenylalanine-dependent oxidation of 7-tetrahydrobiopterin is accompanied by the hydroxylation of the aromatic amino acid substrate only about 15% of the time, i.e. the enzymatic oxidation of 7-tetrahydrobiopterin is about 85% uncoupled from the hydroxylation of the amino acid substrate

Long-term post-fire succession of reptiles in an urban remnant in south-western Australia

Background: Reptile responses to fire may differ between remnants and contiguous vegetation but this is poorly understood. Aims: We aimed to explore long-term (≤15 years) post-fire responses of reptiles in an urban Banksia woodland remnant. Methods: We trapped reptiles for 10 nights in November and December each year between 2009 and 2023 inclusive (except 2014 and 2019) to estimate relative abundance. We used mixed models to explore differences between unburnt and burnt sites and changes in both over time. Key results and conclusions: The reptile community showed short-term negative responses to fire, but communities had returned to their pre-fire state within 3 years. Two species showed short-term (3 and 5 years respectively) negative responses to fire while two species showed positive responses; one in the first year post-fire only, and the other in sites \u3e8 years post-fire. There did not appear to be consistent differences in fire responses between this study and studies conducted in contiguous Banksia woodlands, although differences in study designs renders this conclusion equivocal. Implications: Reptile communities in Banksia woodland remnants, and the species they contain appear to be relatively robust to a wide range of fire regimes

Velocity-resolved observations of water in Comet Halley

High resolution (lambda/delta lambda approx. = 3 x 10 to the 5th power) near-infrared observations of H2O emission from Comet Halley were acquired at the time of maximum post-perihelion geocentric Doppler shift. The observed widths and absolute positions of the H2O line profiles reveal characteristics of the molecular velocity field in the coma. These results support H2O outflow from a Sun-lit hemisphere or the entire nucleus, but not from a single, narrow jet emanating from the nucleus. The measured pre- and post-perihelion outflow velocities were 0.9 + or - 0.2 and 1.4 + or - 0.2 km/s, respectively. Temporal variations in the kinematic properties of the outflow were inferred from changes in the spectral line shapes. These results are consistent with the release of H2O into the coma from multiple jets

Children Get Ready to Read

One of the major concerns of early childhood education has been. and will continue to be, the development of an optimal readiness program for children. (Almy, 1967)

Surface enhanced Raman spectroscopy of neurotransmitters

The surface‐enhanced Raman spectra (SERS) of neurotransmitters in biological matrices and synthetic solutions are described. The effects of protein adsorption on cathecholamine SERS intensity are discussed. Techniques for obtaining dopamine SERS spectra in cerebrospinal fluid and rat brain dialysate are demonstrated. Preliminary SERS of histamine and tel‐methylhistamine are presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87497/2/707_1.pd

FeH Absorption in the Near-Infrared Spectra of Late M and L Dwarfs

We present medium-resolution z-, J-, and H-band spectra of four late-type dwarfs with spectral types ranging from M8 to L7.5. In an attempt to determine the origin of numerous weak absorption features throughout their near-infrared spectra, and motivated by the recent tentative identification of the E 4\Pi- A ^4\Pi system of FeH near 1.6 microns in umbral and cool star spectra, we have compared the dwarf spectra to a laboratory FeH emission spectrum. We have identified nearly 100 FeH absorption features in the z-, J-, and H-band spectra of the dwarfs. In particular, we have identified 34 features which dominate the appearance of the H-band spectra of the dwarfs and which appear in the laboratory FeH spectrum. Finally, all of the features are either weaker or absent in the spectrum of the L7.5 dwarf which is consistent with the weakening of the known FeH bandheads in the spectra of the latest L dwarfs.Comment: accepted by Ap