Early onset airway obstruction in response to organic dust in the horse

Equine recurrent airway obstruction (RAO) has been used as a naturally occurring model of human asthma. However, it is unknown whether there is an early-phase response in RAO. The aim of this study was to determine whether exposure to organic dust induces immediate changes in lung function in RAO-affected horses, which could be mediated by airway mast cells. Six RAO-affected horses in remission and six control horses were challenged with hay-straw dust suspension by nebulization. Total respiratory resistance at 1 Hz, measured by forced oscillation, was increased from 0.62 +/- 0.09 cmH(2)O.l(-1).s (mean +/- SE) to 1.23 +/- 0.20 cmH(2)O.l(-1).s 15 min after nebulization in control horses (P = 0.023) but did not change significantly in the RAO group. Total respiratory reactance at 1 Hz (P = 0.005) was significantly lower in the control horses (-0.77 +/- 0.07 cmH(2)O.l(-1).s) than in the RAO group (-0.49 +/- 0.04 cmH(2)O.l(-1).s) 15 min after nebulization. Bronchoalveolar lavage fluid (BALF) histamine concentration was significantly elevated 10 and 20 min postnebulization in control horses but not in RAO horses. Minimum reactance at 1 Hz in the early postnebulization period significantly correlated with both prechallenge BALF mast cell numbers (r = -0.65, P = 0.02) and peak BALF histamine concentration postnebulization (r = -0.61, P = 0.04). In conclusion, RAO horses, unlike human asthmatic patients, do not exhibit an early-phase response. However, healthy control horses do demonstrate a mild but significant early (<20 min) phase response to inhaled organic dust. This response may serve to decrease the subsequent dose of dust inhaled and as such provide a protective mechanism, which may be compromised in RAO horses

Credit Constraints and the Measurement of Time Preferences

Incentivized experiments are commonly used to estimate marginal rates of intertemporal substitution (MRS) in the lab and in the field in order to make inferences about individual time preferences. This paper considers an integrated model of behavior in which individuals are subject to financial shocks and credit constraints, and take those into account when making experimental choices. The model shows that measured MRS depends on the individual’s effective interest rate which is equal to the relative marginal utility of current and future consumption. Experimental responses should therefore be correlated with other variables that describe the subject’s financial situation, like savings and shocks to income and consumption. We test the model using a new a panel data set from Mali and find evidence for such effects. Our results imply that the relationship between experimentally elicited MRS and time preferences is not straightforward. However, measured MRS can be useful in determining the importance of different types of financial shocks to the household

Life-Cycle Consumption Patterns at Older Ages in the US and the UK: Can Medical Expenditures Explain the Difference?

In this paper we document significantly steeper declines in nondurable expenditures in the UK compared to the US, in spite of income paths being similar. We explore several possible causes, including different employment paths, housing ownership and expenses, levels and paths of health status, and out-of -pocket medical expenditures. Among all the potential explanations considered, we find that those to do with healthcare - differences in levels, age paths, and uncertainty in medical expenses - are the main factor accounting for the steeper declines in nondurable expenses in the US compared to the UK

Transverse momentum and centrality dependence of dihadron correlations in Au+Au collisions at sqrt(s_NN)=200 GeV: Jet-quenching and the response of partonic matter

Azimuthal angle \Delta\phi correlations are presented for charged hadrons from dijets for 0.4 < p_T < 10 GeV/c in Au+Au collisions at sqrt(s_NN) = 200 GeV. With increasing p_T, the away-side distribution evolves from a broad to a concave shape, then to a convex shape. Comparisons to p+p data suggest that the away-side can be divided into a partially suppressed "head" region centered at Delta\phi ~ \pi, and an enhanced "shoulder" region centered at Delta\phi ~ \pi +/- 1.1. The p_T spectrum for the "head" region softens toward central collisions, consistent with the onset of jet quenching. The spectral slope for the "shoulder" region is independent of centrality and trigger p_T, which offers constraints on energy transport mechanisms and suggests that the "shoulder" region contains the medium response to energetic jets.Comment: 420 authors from 58 institutions, 6 pages, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Quantitative Constraints on the Transport Properties of Hot Partonic Matter from Semi-Inclusive Single High Transverse Momentum Pion Suppression in Au+Au collisions at sqrt(s_NN) = 200 GeV

The PHENIX experiment has measured the suppression of semi-inclusive single high transverse momentum pi^0's in Au+Au collisions at sqrt(s_NN) = 200 GeV. The present understanding of this suppression is in terms of energy-loss of the parent (fragmenting) parton in a dense color-charge medium. We have performed a quantitative comparison between various parton energy-loss models and our experimental data. The statistical point-to-point uncorrelated as well as correlated systematic uncertainties are taken into account in the comparison. We detail this methodology and the resulting constraint on the model parameters, such as the initial color-charge density dN^g/dy, the medium transport coefficient , or the initial energy-loss parameter epsilon_0. We find that high transverse momentum pi^0 suppression in Au+Au collisions has sufficient precision to constrain these model dependent parameters at the +/1 20%-25% (one standard deviation) level. These constraints include only the experimental uncertainties, and further studies are needed to compute the corresponding theoretical uncertainties.Comment: 422 authors, 13 pages text, RevTeX-4, 9 figures, 2 tables. This version is updated with changes made during the review process and is now the same as what was published in Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are publicly available at http://www.phenix.bnl.gov/papers.htm

Measurement of high-p_T Single Electrons from Heavy-Flavor Decays in p+p Collisions at sqrt(s) = 200 GeV

The momentum distribution of electrons from decays of heavy flavor (charm and beauty) for midrapidity |y| < 0.35 in p+p collisions at sqrt(s) = 200 GeV has been measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) over the transverse momentum range 0.3 < p_T < 9 GeV/c. Two independent methods have been used to determine the heavy flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log pQCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.72 +/- 0.02^stat +/- 0.19^sys for 0.3 < p_T < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma_(c c^bar) = 567 +/- 57^stat +/- 224^sys micro barns.Comment: 375 authors from 57 institutions, 6 pages, 3 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Charged hadron multiplicity fluctuations in Au+Au and Cu+Cu collisions from sqrt(s_NN) = 22.5 to 200 GeV

A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for non-dynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. An analysis of Negative Binomial Distribution fits to the multiplicity distributions demonstrates that the heavy ion data exhibit weak clustering properties.Comment: 464 authors from 60 institutions, 17 pages, 12 figures, 1 table. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Identified charged hadron production in p+p collisions at sqrt(s)=200 and 62.4 GeV

Transverse momentum distributions and yields for $\pi^{\pm}$, $K^{\pm}$, $p$ and $\bar{p}$ in $p+p$ collisions at $\sqrt{s}$=200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). These data provide important baseline spectra for comparisons with identified particle spectra in heavy ion collisions at RHIC. We present the inverse slope parameter $T_{\rm inv}$, mean transverse momentum $$ and yield per unit rapidity $dN/dy$ at each energy, and compare them to other measurements at different $\sqrt{s}$ in $p+p$ and $p+\bar{p}$ collisions. We also present the scaling properties such as $m_T$ scaling, $x_T$ scaling on the $p_T$ spectra between different energies. To discuss the mechanism of the particle production in $p+p$ collisions, the measured spectra are compared to next-to-leading-order or next-to-leading-logarithmic perturbative quantum chromodynamics calculations.Comment: 431 authors from 62 institutions, 32 pages, 23 figures, and 18 tables. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Cross section and double helicity asymmetry for eta mesons and their comparison to neutral pion production in p+p collisions at sqrt(s)=200 GeV

Measurements of double-helicity asymmetries for inclusive hadron production in polarized p+p collisions are sensitive to helicity--dependent parton distribution functions, in particular to the gluon helicity distribution, Delta(g). This study focuses on the extraction of the double-helicity asymmetry in eta production: polarized p+p --> eta + X, the eta cross section, and the eta/pi^0 cross section ratio. The cross section and ratio measurements provide essential input for the extraction of fragmentation functions that are needed to access the helicity-dependent parton distribution functions.Comment: 432 authors from 62 institutions, 13 pages, 5 figures, and 3 tables. Submitted to Physical Review D. v2 has minor changes only to update references and reposition figures and tables. All data points plotted in Figs. 2, 4, and 5 are given in Tables I, II, and III, respectivel