Electron and Photon Interactions in the Regime of Strong LPM Suppression

Most searches for ultra-high energy (UHE) astrophysical neutrinos look for radio emission from the electromagnetic and hadronic showers produced in their interactions. The radio frequency spectrum and angular distribution depend on the shower development, so are sensitive to the interaction cross sections. At energies above about 10^{16} eV (in ice), the Landau-Pomeranchuk-Migdal (LPM) effect significantly reduces the cross sections for the two dominant electromagnetic interactions: bremsstrahlung and pair production. At higher energies, above about 10^{20} eV, the photonuclear cross section becomes larger than that for pair production, and direct pair production and electronuclear interactions become dominant over bremsstrahlung. The electron interaction length reaches a maximum around 10^{21} eV, and then decreases slowly as the electron energy increases further. In this regime, the growth in the photon cross section and electron energy loss moderates the rise in nu_e shower length, which rises from ~10 m at 10^{16} eV to ~50 m at 10^{19} eV and ~100 m at 10^{20} eV, but only to ~1 km at 10^{24} eV. In contrast, without photonuclear and electronuclear interactions, the shower length would be over 10 km at 10^{24} eV.Comment: 10 pages, 9 figures. Submitted to Physical Review

Intermedia Substitutability and Market Demand by National Advertisers

We assess substitutable and complementary relationships among eight national advertising media classes, as well as the magnitude of their own-price elasticities. We use a translog demand model, whose parameters we estimate by three-stage least squares, based on 1960-94 annual U.S. data.We find aggregate demand by national advertisers for each of the eight media is own-price inelastic, and that cross-price elasticities suggest slightly more substitute than complementary relationships, although both are rather weak. These patterns are consistent with long prevailing institutional arrangements and media selection practices.

Rural Bashing

Anti-rural sentiment is expressed in the United States in three major threads. The first is a narrative about the political structure of our representative democracy—an assertion that rural people are over-represented thanks to the structural features of the U.S. Senate and the Electoral College. Because rural residents are less than a fifth of the U.S. population, complaints about this situation are often framed as “minority rule.” The second thread is related to the first: rural people and their communities get more than their fair share from federal government coffers. The argument, often expressed in terms of “subsidies,” is that rural places enjoy disproportionate government investments, especially from the federal government, in forms such as social safety net payments, infrastructure investments, and payments associated with the Farm Bill. These investments are said not to be justified by the relatively low amount of taxes rural folks pay and their small populations. Some see these investments as a function of earmarks and pork-barrel politics attributable to outsized small-state power in the U.S. Senate. Implicit in this line of thinking is that urban America does not get enough return on its investment in rural America. It may even evince a lack of awareness that rural and urban are interdependent and that urban folks do enjoy—even rely upon the fruits of rural labor. The third thread, which emerges from the other two, is a culture of annoyance, even disdain, directed by metropolitan dwellers at rural people, their cultural trappings, and their intelligence. This contempt for rural people seems to envision and target an imagined caricature of working-class and illiberal White Americans; it tends to merge negative associations of working-class Whites with rurality in a “hillbilly” or “redneck” stereotype.19 Such contempt effectively “other[s]” rural folks, marginalizing them from mainstream society as manifested in urban norms. All three of these phenomena fuel an impulse to dismiss rural needs and penalize rural residents. This unfortunate framing necessarily overlooks the complex realities of rural life, as well as the nuances of rural power and powerlessness. Among other goals, we seek in this Article to re-complicate the situation of rural people as a step toward rural-urban détente, even collaboration. Our task is not to rebut every criticism of rural populations and lifestyles. It is, rather, to document the extreme animus and call attention to how it undermines the wellbeing of communities along the rural-urban continuum. We are deeply concerned that rural bashing hinders coalition building that could solve problems afflicting both urban and rural places

Experience with Community‐Based Amphotericin B Infusion Therapy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90368/1/phco.25.5.690.63591.pd

Radio Continuum and Star Formation in CO-rich Early Type Galaxies

In this paper we present new high resolution VLA 1.4 GHz radio continuum observations of five FIR bright CO-rich early-type galaxies and two dwarf early-type galaxies. The position on the radio-FIR correlation combined with striking agreements in morphology between high resolution CO and radio maps show that the radio continuum is associated with star formation in at least four of the eight galaxies. The average star formation rate for the sample galaxies detected in radio is approximately 2 solar masses per year. There is no evidence of a luminous AGN in any of our sample galaxies. We estimate Toomre Q values and find that the gas disks may well be gravitationally unstable, consistent with the above evidence for star formation activity. The radio continuum emission thus corroborates other recent suggestions that star formation in early type galaxies may not be uncommon.Comment: 21 pages, 7 figures, to be published in the Astronomical Journa

High frequencies of PMN-MDSCs are associated with low suppressive capacity in advanced stages of HIV-1 infection

Background Polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are an immature cell type that inhibits the effector functions of T lymphocytes in chronic HIV infection. A well-known immunological feature of the disease course is the development of immune exhaustion, which is correlated with excessive immune activation in late-stage disease. Here, we hypothesized that immune exhaustion would also affect PMN-MDSCs in late-stage HIV-1 infection. Methods We evaluated untreated chronically HIV-infected patients (progressors, n = 10) and control groups (controllers, patients with non-small cell lung carcinoma and healthy controls, n = 16) with regard to levels of PMN-MDSCs and their inhibitory potential. Additionally, we studied CD8 T cell effector functions (interferon-gamma, TNF alpha, IL-2 and CD107) and parameters of CD8 T cell activation (CD38 and HLA-DR) and exhaustion (PD-1 and LAG-3) by flow cytometry. Plasma inflammation markers analyzed here were IL-6, IL-8, soluble CD14, highly sensitive CRP, and cystatin C. Results Coincubation experiments with isolated PMN-MDSCs led to a significant inhibition of CD8 T cell proliferation (p < 0.0001), with a significant correlation between PMN-MDSC frequency and suppressive capacity: the higher the frequency of PMN-MDSCs was, the lower the suppressive capacity (rho = 0.51, p = 0.0082). Stratifying all study subjects into subgroups with PMN-MDSC frequencies above or below 2.5% resulted in a significantly increased suppressive capacity in patients with frequencies below 2.5% (p = 0.021). While there was no correlation with the cellular activation markers CD38 and HLA-DR, high IL-8 levels were significantly associated with high PMN-MDSC frequencies (rho = 0.52, p = 0.0074) and low suppressive capacity (rho = 0.47, p = 0.019). Conclusions In this study, we demonstrate for the first time that PMN-MDSCs show limited effector functions in advanced disease stages of HIV infection. The hyperactive immune state is associated with this loss of function. However, we show an association with the proinflammatory cytokine IL-8, which is an important factor for the migration and adhesion of polymorphonuclear cells

The STAR Time Projection Chamber: A Unique Tool for Studying High Multiplicity Events at RHIC

The STAR Time Projection Chamber (TPC) is used to record collisions at the Relativistic Heavy Ion Collider (RHIC). The TPC is the central element in a suite of detectors that surrounds the interaction vertex. The TPC provides complete coverage around the beam-line, and provides complete tracking for charged particles within +- 1.8 units of pseudo-rapidity of the center-of-mass frame. Charged particles with momenta greater than 100 MeV/c are recorded. Multiplicities in excess of 3,000 tracks per event are routinely reconstructed in the software. The TPC measures 4 m in diameter by 4.2 m long, making it the largest TPC in the world.Comment: 28 pages, 11 figure

Acute Decline in Renal Function, Inflammation, and Cardiovascular Risk after an Acute Coronary Syndrome

Background and objectives: Chronic kidney disease is associated with a higher risk of cardiovascular outcomes. The prognostic significance of worsening renal function has also been shown in various cohorts of cardiac disease; however, the predictors of worsening renal function and the contribution of inflammation remains to be established. Design, setting, participants, & measurements: Worsening renal function was defined as a 25% or more decrease in estimated GFR (eGFR) over a 1-mo period in patients after a non-ST or ST elevation acute coronary syndromes participating in the Aggrastat-to-Zocor Trial; this occurred in 5% of the 3795 participants. Results: A baseline C-reactive protein (CRP) in the fourth quartile was a significant predictor of developing worsening renal function (odds ratio, 2.48; 95% confidence interval, 1.49, 4.14). After adjusting for baseline CRP and eGFR, worsening renal function remained a strong multivariate predictor for the combined cardiovascular composite of CV death, recurrent myocardial infarction (MI), heart failure or stroke (hazard ratio, 1.6; 95% confidence interval, 1.1, 2.3). Conclusions: Patients with an early decline in renal function after an acute coronary syndrome are at a significant increased risk for recurrent cardiovascular events. CRP is an independent predictor for subsequent decline in renal function and reinforces the idea that inflammation may be related to the pathophysiology of progressive renal disease

Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for Human Leukocyte Antigen B (HLA-B) Genotype and Allopurinol Dosing: 2015 update

The Clinical Pharmacogenetics Implementation Consortium (CPIC) Guidelines for HLA-B*58:01 Genotype and Allopurinol Dosing was originally published in February 2013. We reviewed the recent literature and concluded that none of the evidence would change the therapeutic recommendations in the original guideline; therefore, the original publication remains clinically current. However, we have updated the Supplemental Material and included additional resources for applying CPIC guidelines into the electronic health record. Up-to-date information can be found at PharmGKB (http://www.pharmgkb.org)