A comparison of the globular cluster luminosity functions of the inner and outer halo of the Milky Way and M31

We show that the globular cluster luminosity function (GCLF) of the inner halo of the Milky Way is statistically different from the GCLF of the outer halo. We also find a similar difference between the inner and outer halo population of M31. We assert that this difference is evidence for some form of dynamical evolution of the cluster population and/or a dependence of GCLF shape on the environment in which the cluster population formed. We also find that the turnover luminosity of the GCLF is unaffected by these differences and further assert that this stability of the turnover luminosity affirms its usefulness as an indicator of cosmic distance.Comment: 3 pages, 2 figures, submitted to MNRA

Effective algorithm of analysis of integrability via the Ziglin's method

In this paper we continue the description of the possibilities to use numerical simulations for mathematically rigorous computer assisted analysis of integrability of dynamical systems. We sketch some of the algebraic methods of studying the integrability and present a constructive algorithm issued from the Ziglin's approach. We provide some examples of successful applications of the constructed algorithm to physical systems.Comment: a figure added, version accepted to JDC

Underpricing, underperformance and overreaction in initial public offerings : evidence from investor attention using online searches

Online activity of Internet users has proven very useful in modeling various phenomena across a wide range of scientific disciplines. In our study, we focus on two stylized facts or puzzles surrounding the initial public offerings (IPOs) - the underpricing and the long-term underperformance. Using the Internet searches on Google, we proxy the investor attention before and during the day of the offering to show that the high attention IPOs have different characteristics than the low attention ones. After controlling for various effects, we show that investor attention still remains a strong component of the high initial returns (the underpricing), primarily for the high sentiment periods. Moreover, we demonstrate that the investor attention partially explains the overoptimistic market reaction and thus also a part of the long-term underperformance

Higher Loop Spin Field Correlators in D=4 Superstring Theory

We develop calculational tools to determine higher loop superstring correlators involving massless fermionic and spin fields in four space time dimensions. These correlation functions are basic ingredients for the calculation of loop amplitudes involving both bosons and fermions in D=4 heterotic and superstring theories. To obtain the full amplitudes in Lorentz covariant form the loop correlators of fermionic and spin fields have to be expressed in terms of SO(1,3) tensors. This is one of the main achievements in this work.Comment: 59 pages, 1 figure; v2: final version published in JHE

The T cell antigen receptor complex expressed on normal peripheral blood CD4-, CD8- T lymphocytes. A CD3-associated disulfide-linked gamma chain heterodimer.

IL-2-dependent cell lines were established from normal peripheral blood T lymphocytes that express neither CD4 nor CD8 differentiation antigens. CD3+,4-,8- cell lines from 15 different donors failed to react with WT31, an mAb directed against the T cell antigen receptor alpha/beta heterodimer. Anti-Leu-4 mAb was used to isolate the CD3/T cell antigen receptor complex from 125I-labeled CD3+,4-,8- (WT31-) T cells. Using detergent conditions that preserved the CD3/T cell antigen receptor complex, an approximately 90 kD disulfide-linked heterodimer, composed of approximately 45- and approximately 40- (or approximately 37-) kD subunits, was coimmunoprecipitated with the invariant 20-29-kD CD3 complex. Analysis of these components by nonequilibrium pH gradient electrophoresis indicated that the approximately 40-kD and approximately 37-kD subunits were similar, and quite distinct from the more basic approximately 45-kD subunit. None of these three subunits reacted with an antibody directed against a beta chain framework epitope. Heteroantiserum against a T cell receptor gamma chain peptide specifically reacted with both the approximately 37- and approximately 40-kD CD3-associated proteins, but not with the approximately 45-kD subunit. CD3+,4-,8- cells failed to transcribe substantial amounts of functional 1.3-kb beta or 1.6-kb alpha mRNA, but produced abundant 1.6-kb gamma mRNA. Southern blot analysis revealed that these CD3+,4-,8- cell lines rearranged both gamma and beta genes, and indicated that the populations were polyclonal. The expression of a CD3-associated disulfide-linked heterodimer on CD3+,4-,8- T cell lines established from normal, adult peripheral blood contrasts with prior reports describing a CD3-associated non-disulfide-linked heterodimer on CD3+/WT31- cell lines established from thymus and peripheral blood obtained from patients with immunodeficiency diseases. We propose that this discrepancy may be explained by preferential usage of the two C gamma genes in T lymphocytes

Nucleic acid-based approaches to investigate microbial-related cheese quality defects

peer-reviewedThe microbial profile of cheese is a primary determinant of cheese quality. Microorganisms can contribute to aroma and taste defects, form biogenic amines, cause gas and secondary fermentation defects, and can contribute to cheese pinking and mineral deposition issues. These defects may be as a result of seasonality and the variability in the composition of the milk supplied, variations in cheese processing parameters, as well as the nature and number of the non-starter microorganisms which come from the milk or other environmental sources. Such defects can be responsible for production and product recall costs and thus represent a significant economic burden for the dairy industry worldwide. Traditional non-molecular approaches are often considered biased and have inherently slow turnaround times. Molecular techniques can provide early and rapid detection of defects that result from the presence of specific spoilage microbes and, ultimately, assist in enhancing cheese quality and reducing costs. Here we review the DNA-based methods that are available to detect/quantify spoilage bacteria, and relevant metabolic pathways in cheeses and, in the process, highlight how these strategies can be employed to improve cheese quality and reduce the associated economic burden on cheese processors.This work was funded by the Department of Agriculture, Food and the Marine under the Food Institutional Research Measure. Daniel J. O’Sullivan is in receipt of a Teagasc Walsh Fellowship, Grant Number:2012205

T-Branes and Monodromy

We introduce T-branes, or "triangular branes," which are novel non-abelian bound states of branes characterized by the condition that on some loci, their matrix of normal deformations, or Higgs field, is upper triangular. These configurations refine the notion of monodromic branes which have recently played a key role in F-theory phenomenology. We show how localized matter living on complex codimension one subspaces emerge, and explain how to compute their Yukawa couplings, which are localized in complex codimension two. Not only do T-branes clarify what is meant by brane monodromy, they also open up a vast array of new possibilities both for phenomenological constructions and for purely theoretical applications. We show that for a general T-brane, the eigenvalues of the Higgs field can fail to capture the spectrum of localized modes. In particular, this provides a method for evading some constraints on F-theory GUTs which have assumed that the spectral equation for the Higgs field completely determines a local model.Comment: 110 pages, 5 figure

Potential Role of Ultrafine Particles in Associations between Airborne Particle Mass and Cardiovascular Health

Numerous epidemiologic time-series studies have shown generally consistent associations of cardiovascular hospital admissions and mortality with outdoor air pollution, particularly mass concentrations of particulate matter (PM) ≤2.5 or ≤10 μm in diameter (PM(2.5), PM(10)). Panel studies with repeated measures have supported the time-series results showing associations between PM and risk of cardiac ischemia and arrhythmias, increased blood pressure, decreased heart rate variability, and increased circulating markers of inflammation and thrombosis. The causal components driving the PM associations remain to be identified. Epidemiologic data using pollutant gases and particle characteristics such as particle number concentration and elemental carbon have provided indirect evidence that products of fossil fuel combustion are important. Ultrafine particles < 0.1 μm (UFPs) dominate particle number concentrations and surface area and are therefore capable of carrying large concentrations of adsorbed or condensed toxic air pollutants. It is likely that redox-active components in UFPs from fossil fuel combustion reach cardiovascular target sites. High UFP exposures may lead to systemic inflammation through oxidative stress responses to reactive oxygen species and thereby promote the progression of atherosclerosis and precipitate acute cardiovascular responses ranging from increased blood pressure to myocardial infarction. The next steps in epidemiologic research are to identify more clearly the putative PM casual components and size fractions linked to their sources. To advance this, we discuss in a companion article (Sioutas C, Delfino RJ, Singh M. 2005. Environ Health Perspect 113:947–955) the need for and methods of UFP exposure assessment