The Giant Inflaton

We investigate a new mechanism for realizing slow roll inflation in string theory, based on the dynamics of p anti-D3 branes in a class of mildly warped flux compactifications. Attracted to the bottom of a warped conifold throat, the anti-branes then cluster due to a novel mechanism wherein the background flux polarizes in an attempt to screen them. Once they are sufficiently close, the M units of flux cause the anti-branes to expand into a fuzzy NS5-brane, which for rather generic choices of p/M will unwrap around the geometry, decaying into D3-branes via a classical process. We find that the effective potential governing this evolution possesses several epochs that can potentially support slow-roll inflation, provided the process can be arranged to take place at a high enough energy scale, of about one or two orders of magnitude below the Planck energy; this scale, however, lies just outside the bounds of our approximations.Comment: 31 pages, 4 figures, LaTeX. v2: references added, typos fixe

Dephasing of Electrons on Helium by Collisions with Gas Atoms

The damping of quantum effects in the transport properties of electrons deposited on a surface of liquid helium is studied. It is found that due to vertical motion of the helium vapour atoms the interference of paths of duration $t$ is damped by a factor $\exp - (t/\tau_v)^3$. An expression is derived for the weak-localization lineshape in the case that damping occurs by a combination of processes with this type of cubic exponential damping and processes with a simple exponential damping factor.Comment: 7 pages, 2 figures, Revte

Brane/Flux Annihilation and the String Dual of a Non-Supersymmetric Field Theory

We consider the dynamics of p anti-D3 branes inside the Klebanov-Strassler geometry, the deformed conifold with M units of RR 3-form flux around the S^3. We find that for p<<M the system relaxes to a nonsupersymmetric NS 5-brane ``giant graviton'' configuration, which is classically stable, but quantum mechanically can tunnel to a nearby supersymmetric vacuum with M-p D3 branes. This decay mode is exponentially suppressed and proceeds via the nucleation of an NS 5-brane bubble wall. We propose a dual field theory interpretation of the decay as the transition between a nonsupersymmetric ``baryonic'' branch and a supersymmetric ``mesonic'' branch of the corresponding SU(2M-p)x SU(M-p) low energy gauge theory. The NS 5-brane tunneling process also provides a simple explanation of the geometric transition by which D3-branes can dissolve into 3-form flux.Comment: 27 pages, 4 figures, typo correcte

Problems experienced by secondary school deputy principals in diverse contexts: a South African study

This paper reports on research that was undertaken to determine the problems experienced by deputy principals in secondary schools, and the extent to which these problems were experienced. Although some research was conducted on the deputy principalship, no research treats the problems that deputy principals experience upon appointment comprehensively. An understanding of the problems experienced by secondary school deputy principals is a necessary precursor of an induction program to address the problems. A quantitative approach which was underpinned by the post-positivist paradigm was adopted. In order to determine the extent to which the problems were experienced, a survey was conducted among one hundred and fifty seven secondary school deputy principals in the North West Province. The participants came from a diverse context of rural, township and urban schools. The deputy principals who participated in the study included those who were newly appointed (one to three years of service) and those who were experienced (more than three years of service). Data were analyzed by means of descriptive statistics such as frequencies, means and percentages. There were no significant differences in the responses of both newly-appointed and experienced deputy principals. The results revealed that deputy principals experienced administrative, financial management, work pressure, personal and physical resources problems. In an attempt to address the problems identified, a context-specific induction program is recommended. The induction program should be an on-going program of professional development and should preferably include specific aims, action steps to be taken to achieve the aims that are set and measures to evaluate progress

A randomized controlled trial of eplerenone in asymptomatic phospholamban p.Arg14del carriers

Phospholamban (PLN; p.Arg14del) cardiomyopathy is an inherited disease caused by the pathogenic p.Arg14del variant in the PLN gene. Clinically, it is characterized by malignant ventricular arrhythmias and progressive heart failure.1,2 Cardiac fibrotic tissue remodelling occurs early on in PLN p.Arg14del carriers.3,4 Eplerenone was deemed a treatment candidate because of its beneficial effects on ventricular remodelling and antifibrotic properties.5,6 We conducted the multicentre randomized trial ‘intervention in PHOspholamban RElated CArdiomyopathy STudy’ (i-PHORECAST) to assess whether treatment with eplerenone of asymptomatic PLN p.Arg14del carriers attenuates disease onset and progression

The 2009 edition of the GEISA spectroscopic database

The updated 2009 edition of the spectroscopic database GEISA (Gestionet Etudedes Informations Spectroscopiques Atmospheriques ; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1. GEISA, continuously developed and maintained at LMD (Laboratoirede Meteorologie Dynamique, France) since 1976, is implemented on the IPSL/CNRS(France) ‘‘Ether’’ Products and Services Centre WEB site (http://ether.ipsl.jussieu.fr), where all archived spectroscopic data can be handled through general and user friendly associated managements of software facilities. More than 350 researchers are registered for online use of GEISA

Portion Size: What We Know and What We Need to Know

There is increasing evidence that the portion sizes of many foods have increased and in a laboratory at least this increases the amount eaten. The conclusions are, however, limited by the complexity of the phenomenon. There is a need to consider meals freely chosen over a prolonged period when a range of foods of different energy densities are available. A range of factors will influence the size of the portion size chosen: amongst others packaging, labeling, advertising, and the unit size rather than portion size of the food item. The way portion size interacts with the multitude of factors that determine food intake needs to be established. In particular, the role of portion size on energy intake should be examined as many confounding variables exist and we must be clear that it is portion size that is the major problem. If the approach is to make a practical contribution, then methods of changing portion sizes will need to be developed. This may prove to be a problem in a free market, as it is to be expected that customers will resist the introduction of smaller portion sizes, given that value for money is an important motivator