Resolution of the strong CP problem

It is shown that the quark mass aligns QCD $\theta$ vacuum in such a way that the strong CP is conserved, resolving the strong CP problem.Comment: 9 pages;v2 slightly rewritten and expanded;v3 a few points clarified;v4 minor changes, journal versio

Modeling the Void H I Column Density Spectrum

The equivalent width distribution function (EWDF) of \hone absorbers specific to the void environment has been recently derived (Manning 2002), revealing a large line density of clouds (dN/dz ~500 per unit z for Log (N_HI)> 12.4). I show that the void absorbers cannot be diffuse (or so-called filamentary) clouds, expanding with the Hubble flow, as suggested by N-body/hydro simulations. Absorbers are here modeled as the baryonic remnants of sub-galactic perturbations that have expanded away from their dark halos in response to reionization at z ~ 6.5. A 1-D Lagrangian hydro/gravity code is used to follow the dynamic evolution and ionization structure of the baryonic clouds for a range of halo circular velocities. The simulation products at z=0 can be combined according to various models of the halo velocity distribution function to form a column density spectrum that can be compared with the observed. I find that such clouds may explain the observed EWDF if the halo velocity distribution function is as steep as that advanced by Klypin (1999), and the halo mass distribution is closer to isothermal than to NFW.Comment: 21 pages, 15 figures. Paper in press; ApJ 591, n

Geogrid Reinforced Soil Retaining Wall on Compressible Soils

A geogrid reinforced soil wall with a wrap-around facing system was successfully constructed on soft, compressible alluvial and residual soils. An originally designed 20-foot (6.1 m) high, reinforced concrete cantilever retaining wall was not constructed because of the expected settlements induced by the wall and backfill. The geogrid reinforced wall was utilized because of its ability to withstand the estimated settlement and because it was considered less expensive than providing deep foundation support of a cantilever wall. This paper discusses the design, construction, and performance of the geogrid reinforced wall

A New Technique for Determining the Properties of a Narrow ss-channel Resonance at a Muon Collider

We explore an alternative to the usual procedure of scanning for determining the properties of a narrow $s$-channel resonance. By varying the beam energy resolution while sitting on the resonance peak, the width and branching ratios of the resonance can be determined. The statistical accuracy achieved is superior to that of the usual scan procedure in the case of a light SM-like Higgs boson with \mh>130\gev or for the lightest pseudogoldstone boson of a strong electroweak breaking model if \mpzero>150\gev.Comment: 4 pages, 1 figur

Evolution of Preprofessional Pharmacy Curricula

Objectives. To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. Methods. Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor’s degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. Results. In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor’s degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. Conclusions. The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants

Disgust sensitivity is not associated with health in a rural Bangladeshi sample.

Disgust can be considered a psychological arm of the immune system that acts to prevent exposure to infectious agents. High disgust sensitivity is associated with greater behavioral avoidance of disease vectors and thus may reduce infection risk. A cross-sectional survey in rural Bangladesh provided no strong support for this hypothesis. In many species, the expression of pathogen- and predator-avoidance mechanisms is contingent on early life exposure to predators and pathogens. Using childhood health data collected in the 1990s, we examined if adults with more infectious diseases in childhood showed greater adult disgust sensitivity: no support for this association was found. Explanations for these null finding and possible directions for future research are discussed

The Accretion of Lyman Alplha Clouds onto Gas-Rech Protogalaxies; A Scenario for the Formation of Globular Star Clusters

A satisfactory theory for the formation of globular star clusters (GCs) has long been elusive, perhaps because their true progenitors had not yet been guessed. In this paper I propose a causal relationship between the strongly decreasing densities of Lyman alpha (LyA) clouds at high redshift and the formation of GCs - namely that GCs were created by the accretion of LyA clouds onto protogalaxies. I describe a scenario which involves an inherently stable and orderly cycling of compression and cooling in the central cores of clouds during the extended period of dissipation in the outer regins of gas-rich proto galaxies, culminating in a burst of efficient star formation. I demonstrate that the comoving density of GCs is comparable to that of LyA clouds at high redshift, that the energetic requirements for compression to core GC densities can be met, and that the time-scale for cooling is within obvious limits imposed by dynamical stability. This dissipative process requires there to be a large column of dissipated gas about the attractor in order to form GCs. In addition, the energy requirements for compression requires attractor masses greater than that capable of sustaining circular velocities of ~40 km/s. If this scenario is supported by numerical simulations, then by implication, the GCs were formed at modest redshifts of z~1-3. This knowledge could help to break the degeneracy between lookback time and redshift. The model is consistent with a picture of hierarchical galaxy growth over time scales of many billions of years.Comment: 7 pages. Accepted, 10 June 1999 Astrophysical Journa

The Search for Intergalactic Hydrogen Clouds in Voids

I present the results of a search for intergalactic hydrogen clouds in voids. Clouds are detected by their HI LyA absorption lines in the HST spectra of low-redshift AGN. The parameter with which the environments of clouds are characterized is the tidal field, which places a lower limit on the cloud mass-density which is dynamically stable against disruption. Galaxy redshift catalogs are used to sum the tidal fields along the lines of sight, sorting clouds according to tidal field upper, or lower limits. The analytical methodology employed is designed to detect gas clouds whose expansion following reionization is restrained by dark matter perturbations. End-products are the cloud equivalent width distribution functions (EWDF) of catalogs formed by sorting clouds according to various tidal field upper, or lower limits. Cumulative EWDFs are steep in voids (S ~ -1.5 \pm 0.2), but flatter in high tidal field zones (S ~ -0.5 \pm 0.1). Most probable cloud Doppler parameters are ~30 km/s in voids and ~60 km/s in proximity to galaxies. In voids, the cumulative line density at low EW (~ 15 mA) is ~ 500 per unit redshift. The void filling factor is found to be 0.87 <= f_v <= 0.94. The void EWDF is remarkably uniform over this volume, with a possible tendency for more massive clouds to be in void centers. The size and nature of the void cloud population suggested by this study is completely unanticipated by the results of published 3-D simulations, which predict that most clouds are in filamentary structures around galaxy concentrations, and that very few observable absorbers would lie in voids. Strategies for modeling this population are briefly discussed.Comment: 21 pages, 19 figures, apjemulate style, to appear in ApJ vol. 57

The Nature and Origin of the Non-Void Lyman alpha Cloud Population

I continue my study of the low-z Lyman alpha cloud population. Previously I showed how galaxy catalogs are used to attribute relative degrees of isolation to those clouds found in HST/GHRS spectra. I find that there exist two distinct populations corresponding to two distinct environments, variously characterized as void (unshocked) and non-void (shocked). Void clouds have a steep equivalent width distribution (i.e., many smaller absorbers) while non-void clouds have a flat distribution. These environment-specific observations of LyA clouds show that the predictions from N-body/hydro simulations are incorrect. Simulations fail to predict the existence of significant numbers of detectable void clouds. They incorrectly predict the characteristics of non-void clouds. Implicated in this failure is the so-called fluctuating Gunn-Peterson Approximation (FGPA) which envisions that LyA absorbers are formed in the large-scale structures of coalescing matter. I recently modeled the void cloud population as sub-galactic perturbations that have expanded in response to reionization. However, the success in this modeling was contingent upon using the more massive isothermal halo in place of the standard Navarro, Frenk & White. Here, I extend my modeling to non-void LyA clouds using the same basic cloud model. Nonvoid clouds were once unshocked, but when entering nonvoid space, they are shock stripped. By analytically stripping model void clouds, a good fit of the model CDS to observations is found if cloud velocities are ~100 km/s. Nonvoid clouds show strong concentration around galaxies, suggesting that the compact HVC population are members of this population.Comment: 10 pages, 6 figures, ApJ 595 n1, in pres

The Evo-Eco approach to behaviour change

We introduce a new approach to behaviour change called ‘Evo–Eco’ because of its intellectual roots in evolutionary biology and ecological psychology. This approach is based on the inference that brains evolved to provide adaptive behavioural responses to rapidly changing or complex environmental conditions. From this foundation, we develop a model with three basic components: the environment, which presents some challenge or opportunity to the individual; the brain, which produces potential responses to that challenge; and the body, which engages in interactions with the environment (i.e. produces behaviour) that changes that environment. The behaviours of interest to behaviour-change professionals typically occur in particular settings, which can be seen as a context within which these basic components interact. We report how the approach has been used to develop public health programmes, as well as to make novel predictions about behavioural causes (i.e. placement of new target behaviours within a routine) which have proved to impact on the ability to change a behaviour. The Evo–Eco approach thus deserves to be used by public health workers and others to change behaviour