Leptogenesis via Higgs Condensate Relaxation

An epoch of Higgs relaxation may occur in the early universe during or immediately following postinflationary reheating. It has recently been pointed out that leptogenesis may occur in minimal extensions of the Standard Model during this epoch. We analyse Higgs relaxation taking into account the effects of perturbative and non-perturbative decays of the Higgs condensate, and we present a detailed derivation of the relevant kinetic equations and of the relevant particle interaction cross sections. We identify the parameter space in which a sufficiently large asymmetry is generated.Comment: 18 pages, 14 figure

Leptogenesis Via Neutrino Production During Higgs Condensate Relaxation

During inflation, scalar fields, including the Higgs boson, may acquire a nonzero vacuum expectation value, which must later relax to the equilibrium value during reheating. In the presence of the time-dependent condensate, the vacuum state can evolve into a state with a nonzero particle number. We show that, in the presence of lepton number violation in the neutrino sector, the particle production can explain the observed matter-antimatter asymmetry of the universe. We find that this form of leptogenesis is particularly effective when the Higgs condensate decays rapidly and at low reheat scale. As part of the calculation, we present some exact results for the Bogoliubov transformations for Majorana fermions with a nonzero time-dependent chemical potential, in addition to a time-dependent mass.Comment: 19 pages, 3 figure

The Gender Imbalance in Participation in Canadian Universities (1977-2005)

More females than males have been attending Canadian universities over the past decade and this gender imbalance in university participation has been increasing. We use the Linear Probability and Logit models to investigate the determinants of attending university and explore the reasons for the increasing gender imbalance. We find that, in gender-specific equations, the values of the coefficients attached to variables and the values of the variables themselves are both important in explaining the rising level of the university participation rate for women and men. The important variables include a time trend to capture the evolving societal norms, the dynamic influence of parental education, the earnings premium for a university degree, tuition fees and real income. The increasing gap between the female and male participation rates (15 percentage points by 2005) can be accounted for equally by differences in the coefficients in female and male participation equations and the widening gap in the university premium for women and men.university, participation, gender imbalance

Feature extraction from ear-worn sensor data for gait analysis

Gait analysis has a significant role in assessing human's walking pattern. It is generally used in sports science for understanding body mechanics, and it is also used to monitor patients' neuro-disorder related gait abnormalities. Traditional marker-based systems are well known for tracking gait parameters for gait analysis, however, it requires long set up time therefore very difficult to be applied in everyday realtime monitoring. Nowadays, there is ever growing of interest in developing portable devices and their supporting software with novel algorithms for gait pattern analysis. The aim of this research is to investigate the possibilities of novel gait pattern detection algorithms for accelerometer-based sensors. In particular, we have used e-AR sensor, an ear-worn sensor which registers body motion via its embedded 3-D accelerom-eter. Gait data was given semantic annotation using pressure mat as well as real-time video recording. Important time stamps within a gait cycle, which are essential for extracting meaningful gait parameters, were identified. Furthermore, advanced signal processing algorithm was applied to perform automatic feature extraction by signal decomposition and reconstruction. Analysis on real-word data has demonstrated the potential for an accelerometer-based sensor system and its ability to extract of meaningful gait parameters

The Determinants of University Participation in Canada (1977−2003)

The decision to attend university is influenced by the balance of the expected returns and costs of attending university, by liquidity constraints and capital market imperfections that may modify these calculations and, hence, by the family income of prospective students. Family circumstances also play a role. We examine the secular increase in the propensity of children from Canadian families, evident in annual surveys spanning two and a half decades, to attend university. We quantify the importance of these factors taking account of the greater propensity by young women than men to attend university and controlling for secular trends in socioeconomic norms that impinge on these decisions.university participation, parental education, university premium, gender, tuition, income, societal trends

The Gender Imbalance in Participation in Canadian Universities (1977-2005)

More females than males have been attending Canadian universities over the past decade and this gender imbalance in university participation has been increasing. We use the Linear Probability and Logit models to investigate the determinants of attending university and explore the reasons for the increasing gender imbalance. We find that, in gender-specific equations, the values of the coefficients attached to variables and the values of the variables themselves are both important in explaining the rising level of the university participation rate for women and men. The important variables include a time trend to capture the evolving societal norms, the dynamic influence of parental education, the earnings premium for a university degree, tuition fees and real income. The increasing gap between the female and male participation rates (15 percentage points by 2005) can be accounted for equally by differences in the coefficients in female and male participation equations and the widening gap in the university premium for women and men.University participation, individuals, gender, Canada

Episodic and electrical nervous system disorders caused by nonchannel genes.

As noted in the separate introduction to this special topic section, episodic and electrical disorders can appear quite different clinically and yet share many overlapping features, including attack precipitants, therapeutic responses, natural history, and the types of genes that cause many of the genetic forms (i.e., ion channel genes). Thus, as we mapped and attempted to clone genes causing other episodic disorders, ion channels were always outstanding candidates when they mapped to the critical region of linkage in such a family. However, some of these disorders do not result from mutations in channels. This realization has opened up large and exciting new areas for the pathogenesis of these disorders. In some cases, the mutations occur in genes of unknown function or without understanding of molecular pathogenesis. Recently, emerging insights into a fascinating group of episodic movement disorders, the paroxysmal dyskinesias, and study of the causative genes and proteins are leading to the emerging concept of episodic electric disorders resulting from synaptic dysfunction. Much work remains to be done, but the field is evolving rapidly. As it does, we have come to realize that the molecular pathogenesis of electrical and episodic disorders is more complex than a scenario in which such disorders are simply due to mutations in the primary determinants of membrane excitability (channels)

Parity Reversing Involutions on Plane Trees and 2-Motzkin Paths

The problem of counting plane trees with $n$ edges and an even or an odd number of leaves was studied by Eu, Liu and Yeh, in connection with an identity on coloring nets due to Stanley. This identity was also obtained by Bonin, Shapiro and Simion in their study of Schr\"oder paths, and it was recently derived by Coker using the Lagrange inversion formula. An equivalent problem for partitions was independently studied by Klazar. We present three parity reversing involutions, one for unlabelled plane trees, the other for labelled plane trees and one for 2-Motzkin paths which are in one-to-one correspondence with Dyck paths.Comment: 8 pages, 4 figure

Explicit memory schemes for evolutionary algorithms in dynamic environments

Copyright @ 2007 Springer-VerlagProblem optimization in dynamic environments has atrracted a growing interest from the evolutionary computation community in reccent years due to its importance in real world optimization problems. Several approaches have been developed to enhance the performance of evolutionary algorithms for dynamic optimization problems, of which the memory scheme is a major one. This chapter investigates the application of explicit memory schemes for evolutionary algorithms in dynamic environments. Two kinds of explicit memory schemes: direct memory and associative memory, are studied within two classes of evolutionary algorithms: genetic algorithms and univariate marginal distribution algorithms for dynamic optimization problems. Based on a series of systematically constructed dynamic test environments, experiments are carried out to investigate these explicit memory schemes and the performance of direct and associative memory schemes are campared and analysed. The experimental results show the efficiency of the memory schemes for evolutionary algorithms in dynamic environments, especially when the environment changes cyclically. The experimental results also indicate that the effect of the memory schemes depends not only on the dynamic problems and dynamic environments but also on the evolutionary algorithm used