Duality Invariant Magnetohydrodynamics And Dyons

The theory of magnetohydrodynamics is extended to the cases of a plasma of separate magnetic and electric charges, as well as to a plasma of dyons respectively. In both these cases the system possesses electric-magnetic duality symmetry. In the former case we find that because of the existence of two independent generalized Ohm's law equations, the limit of infinite electric and magnetic conductivity results in the vanishing of both electric and magnetic fields, as well as the corresponding currents. In the dyonic case, we find that the resulting duality-invariant system of equations are equivalent to those of ordinary MHD, after suitable field redefinitions.Comment: 11 pages, late

Controlled Guidance of Light in Large Area Flexible Optical Waveguide Sheets

Large surface area, thin, polymer optical waveguides are an emerging technology that enable a wide variety of light collection and illumination systems to be created for passive lighting, solar collectors, and safety lighting for motorized vehicles. This research builds on design of rigid concentrator and diffuser waveguides, proposing and evaluating modifications for the design of a flexible waveguide combining both concentrating and diffusing functionalities. The waveguides are thin, mechanically flexible sheets with thicknesses in the range of mm, and active surfaces from a few cm2 to several m2. Regions of the functional surface are designed to act as light concentrators, light diffusers, light transmission conduits or some combination thereof. This research examines how the geometry and spatial distribution of micro-optical features patterned on a bi-layered thin polydimethylsiloxane (PDMS) waveguides can be used to guide captured light rays through flat and flexible configurations. Zemax OpticStudio software simulation tool is used to investigate the design parameters and their impact on concentrator and diffuser performance. A multi-functional concentrator-diffuser waveguide is modelled and analysed in a study which shows the flat waveguide has an overall efficiency of over 94%, however when it is modelled as a flexible waveguide, less than 1% of the incident light is successfully guided. Various design modifications are considered to mitigate these losses, and the efficiency of the flexible waveguide is improved to nearly 60%. Based on the parametric optimization of the microfeatures, the suitable waveguide design is identified for variations in the waveguide’s flexibility, geometry, material and application

Using System Dynamics Modelling Approach to Develop Management Tools for Animal Production with Emphasis on Small Ruminants

Small ruminants are important assets in several regions of the world. They account for more than half of the domesticated ruminants. Despite the growth in goat production in the world (more than 2% per year), research related to goat production is less than desired. One underused but potentially valuable approach for research on small ruminants is simulation modelling. Models of the components of small ruminant systems can enhance the financial returns and reduce negative environmental impacts. These models can be used to assess many dimensions of small ruminant production, from rumen dynamics to economic policies designed to support small ruminant production. Understanding the nutrition, production, and economic policy feedback signals and planning ahead is crucial to build a robust and integrated production activity that can be managed under different production scenarios. System Dynamics (SD) is a computer-aided modelling methodology that can be used to perform policy analysis and decision support system (DSS) applied to dynamic problems arising in complex social, managerial, economic, or ecological dynamic systems characterized by interdependence, mutual interaction, information feedback, and circular causality. SD can be used as a modelling tool to aggregate knowledge to solve different types of problems that have a limited scope to a specific location or have broad trends of applications across locations and areas of science. Important issues of broad application include the bearings of animal production in the climate change and the impacts of climate change in animal production, alternative production scenarios of animal and crop integration, associations between animal production and business (economics, marketing). The trend of increasing small ruminants in tropical and subtropical regions and an increasing pressure on tropical and subtropical livestock systems to produce food, to feed livestock, and to produce energy crops warrants the development of DSS to address issues such as what is the “real” benefits of livestock, the negative impacts livestock can have on greenhouse-gas emissions and the environment, and the effects of climate change on livestock systems

Probing strongly interacting atomic gases with energetic atoms

We investigate properties of an energetic atom propagating through strongly interacting atomic gases. The operator product expansion is used to systematically compute a quasiparticle energy and its scattering rate both in a spin-1/2 Fermi gas and in a spinless Bose gas. Reasonable agreement with recent quantum Monte Carlo simulations even at a relatively small momentum k/kF>1.5 indicates that our large-momentum expansions are valid in a wide range of momentum. We also study a differential scattering rate when a probe atom is shot into atomic gases. Because the number density and current density of the target atomic gas contribute to the forward scattering only, its contact density (measure of short-range pair correlation) gives the leading contribution to the backward scattering. Therefore, such an experiment can be used to measure the contact density and thus provides a new local probe of strongly interacting atomic gases.Comment: 35 pages, 11 figures; (v4) published with the new titl

Turning Points in the Development of Blended Families

A modified retrospective interview technique (RIT) was employed with members of 53 blended families to determine the types of turning points they reported experiencing and the developmental trajectories of their respective blended family’s first 4 years. Findings revealed 15 primary types of turning points, of which “Changes in Household Configuration,” “Conflict,” “Holidays/Special Events,” “Quality Time,” and “Family Crisis” were the most frequent. A cluster analysis revealed five basic trajectories of development for the first 48 months of family development: Accelerated, Prolonged, Stagnating, Declining, and High-Amplitude Turbulent. The trajectories differed in the overall positive-to-negative valence ratio, the frequency of conflict related events, the average amplitude of change in feeling like a family, and the current reported level of feeling like a family

A Longitudinal Study of the Temporal Relation Between Problem Gambling and Mental and Substance Use Disorders Among Young Adults

Objective: Relatively little is known about the temporal relation between at-risk gambling or problem gambling (PG) and mental and substance use disorders (SUDs) in young adulthood. Our study aimed to examine whether past-year, at-risk, or PG is associated with incident mental disorders and SUDs (that is, depression, generalized anxiety disorder, obsessive–compulsive disorder [OCD], or alcohol dependence) and illegal drug use, and whether past-year mental disorders and SUDs and illegal drug use is associated with incident at-risk or PG. Method: Data for this longitudinal study were drawn from the Manitoba Longitudinal Study of Young Adults (MLSYA). Respondents aged 18 to 20 years in 2007 were followed prospectively for 5 years. Results: In cross-sectional analyses, at-risk or PG was associated with increased odds of depression, OCD, alcohol dependence, and illegal drug use. In longitudinal analysis at-risk or PG at cycle 1 was associated with incident major depressive disorder, alcohol dependence, and illegal drug use in the follow-up period. Only illegal drug use at cycle 1 was associated with incident at-risk or PG during follow-up. Conclusions: At-risk or PG was associated with more new onset mental disorders and SUDs (depression, alcohol dependence, and illegal drug use), compared with the reverse (illegal drug use was the only association with new onset at-risk or PG). Preventing at-risk or PG from developing early in adulthood may correspond with decreases in new onset mental disorders and SUDs later in adulthood

Recent advances in the vibrational spectroscopic diagnosis of non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths worldwide accounting for 1.69 million deaths in 2015. Studies have indicated a 5 year survival rate of 8%–15% in western countries, although a survival rate as low as 1% has been demonstrated for late stage diagnosis. With the advent of targeted therapies, it is imperative to accurately differentiate non-small cell lung cancer (NSCLC) subtypes in order to ensure efficacy of treatment for patients. Immunohistochemistry and molecular techniques for the diagnosis of NSCLC are increasingly part of the diagnostic algorithm and clinical work-up of lung cancer patients, however due to the limitation of small sample size, overlapping morphological features and molecular characterisation, differential diagnosis of NSCLC still proves challenging. Vibrational spectroscopy has shown promising results for the detection of a variety of cancers and a limited number of studies have focused on lung cancer. Yet to date there has been no published evaluation of vibrational spectroscopy on cytology bronchoscopy samples which may eliminate the necessity for an invasive biopsy procedure. Following an introduction to the epidemiology and etiological factors associated with NSCLC, currently used diagnostic methods and their limitations are presented. A thorough review of Raman and FTIR spectroscopic methods in lung cancer diagnosis is then presented. On review of the literature, vibrational spectroscopy offers an alternative or adjunct diagnostic method to be applied in bronchoscopy cytology samples