Practical considerations for the generation of large-order spherical harmonics

Techniques for generating large-order Y^m_l(θ, ϕ) are discussed

Propositions for information technology: Planning for success

In Canada, the West Vancouver School Board proposed 13 propositions about the selection, management, and effective use of information technology. For each proposition, the senior management included a full outline of the current status, a plan of action, the name of the staff member responsible, and a time line. An external assessment of implementation of each proposition and of the impact on achievement was undertaken. The propositions, clustered in the areas of vision, statement of beliefs, student learning goals, definition, social issues, learning issues, clarification of roles and responsibilities, integration of information delivery systems, community-based information infrastructure, and assessment, are discussed

Comparison of Experimental Strategies to Control Torpedograss

Studies were conducted to evaluate whether the herbicide imazapyr or a combination of imazapyr and fluridone could be used effectively to control torpedograss ( Panicum repens L.), an exotic perennial plant that has replaced more than 6,000 ha of native vegetation and degraded quality wildlife habitat in Lake Okeechobee, Florida. Torpedograss was controlled for more than one year in some areas following a single aerial treatment using 0.56, 0.84, or 1.12 kg acid equivalents (ae) imazapyr/ha. Combining imazapyr and fluridone did not increase the level of torpedograss control. In areas where plant biomass was reduced by fire prior to being treated with 0.84 or 1.12 kg ae imazapyr/ha, torpedograss was controlled for more than two years and native plant species, including duck potato ( Sagittaria lancifolia L.) and pickerelweed ( Pontederia cordata L.) became the dominant vegetation in less than one year. Although torpedograss was controlled in some areas, little or no long-term control was observed at 16 of the 26 treatment locations. To reduce the uncertainty associated with predicting long-term treatment affects, additional studies are needed to determine whether environmental factors such as periphyton mats, plant thatch, hydroperiod and water depth affect treatment efficacy. , h

ILR Impact Brief - Pathways to Success: Human Resource Practices Do Matter

[Extract] Most researchers agree that human resource (HR) practices affect attitudes and discretionary behavior on the job and that employee actions and motivations influence company performance. The academic literature also suggests that investing in employees, through high-commitment HR practices such as internal labor markets, selecting new employees who “fit” the company rather than a particular job, compensating employees on the basis of group and company results, and training and development programs that stress team building and long-term growth, are all indirectly related to organizational success. Missing from the literature is an exploration of the causal mechanisms that mediate between these HR practices and favorable outcomes for companies operating in dynamic environments; this research begins filling the void

Geoengineering: Whiter skies?

One proposed side effect of geoengineering with stratospheric sulfate aerosols is sky whitening during the day and afterglows near sunset, as is seen after large volcanic eruptions. Sulfate aerosols in the stratosphere would increase diffuse light received at the surface, but with a non-uniform spectral distribution. We use a radiative transfer model to calculate spectral irradiance for idealized size distributions of sulfate aerosols. A 2% reduction in total irradiance, approximately enough to offset anthropogenic warming for a doubling of CO_2 concentrations, brightens the sky (increase in diffuse light) by 3 to 5 times, depending on the aerosol size distribution. The relative increase is less when optically thin cirrus clouds are included in our simulations. Particles with small radii have little influence on the shape of the spectra. Particles of radius ∼0.5 μm preferentially increase diffuse irradiance in red wavelengths, whereas large particles (∼0.9 μm) preferentially increase diffuse irradiance in blue wavelengths. Spectra show little change in dominant wavelength, indicating little change in sky hue, but all particle size distributions produce an increase in white light relative to clear sky conditions. Diffuse sky spectra in our simulations of geoengineering with stratospheric aerosols are similar to those of average conditions in urban areas today

The frequency response of temperature and precipitation in a climate model

Dynamic aspects of the climate's response to forcing are typically explored through transient simulations in the time domain. However, because of the large range of time-scales involved, some features are more easily observed in the frequency domain. We compute the frequency-response of the HadCM3L general circulation model (GCM) to sinusoidal perturbations in solar radiative forcing, with periods between 2^(−1/2) and 2^9 (512) years. The global mean temperature response decreases with increasing frequency, and the frequency scaling at time-scales longer than one year is consistent with the behavior of diffusion into a semi-infinite slab. The land-sea contrast and land-averaged precipitation, however, exhibit relatively little dependency on the frequency of the imposed perturbation, with significant response at both short and long periods. Understanding these relative characteristics of different climate variables in the frequency domain is important to understanding the transient response of the climate system to both anthropogenic and natural (e.g., volcanic) forcings; the frequency response is also relevant in understanding the spectrum of natural variability

Higgs Sector of the Left-Right Model with Explicit CP Violation

We explore the Higgs sector of the Minimal Left-Right (LR) Model based on the gauge group SU(2)_L x SU(2)_R x U(1)_{B-L} with explicit CP violation in the Higgs potential. Since flavour-changing neutral current experiments and the small scale of neutrino masses both place stringent constraints on the Higgs potential, we seek to determine whether minima of the Higgs potential exist that are consistent with current experimental bounds. We focus on the case in which the right-handed symmetry-breaking scale is only ``moderately'' large, of order 15-50 TeV. Unlike the case in which the Higgs potential is CP-invariant, the CP noninvariant case does yield viable scenarios, although these require a small amount of fine-tuning. We consider a LR model supplemented by an additional U(1) horizontal symmetry, which results in a Higgs sector consistent with current experimental constraints and a realistic spectrum of neutrino masses.Comment: 20 pages, 2 figure

Mitigating Environmental Externalities through Voluntary and Involuntary Water Reallocation: Nevada's Truckee-Carson River Basin

A transition from the era of building water projects and developing new supplies to an era of water reallocation is well underway in most of the West. Two decades ago, experts were debating the ability of western water institutions, originally conceived to serve the earliest non-native water diverters-irrigators and mines -- to adapt to the growing demands of cities. By acquiring water formerly used to grow crops, through voluntary market transactions, western cities have demonstrated that water law and policy prove flexible when the economic and political stakes are high enough.Initially fueled by urban growth, water reallocation is now being stimulated by a new array of forces. Throughout the West, water reallocation is beginning to reflect environmental benefits alongside the traditional uses for water in irrigation, cities, and industry. Some reallocations have involved market transfers of water arranged through voluntary negotiations; others have involved involuntary reallocations prompted by court rulings. This article argues that both types of reallocation will continue to be important in managing western water resources, but that each has quite different implications for the distribution of benefits and costs from reallocation

Green's Function Method for Line Defects and Gapless Modes in Topological Insulators : Beyond Semiclassical Approach

Defects which appear in heterostructure junctions involving topological insulators are sources of gapless modes governing the low energy properties of the systems, as recently elucidated by Teo and Kane [Physical Review B82, 115120 (2010)]. A standard approach for the calculation of topological invariants associated with defects is to deal with the spatial inhomogeneity raised by defects within a semiclassical approximation. In this paper, we propose a full quantum formulation for the topological invariants characterizing line defects in three-dimensional insulators with no symmetry by using the Green's function method. On the basis of the full quantum treatment, we demonstrate the existence of a nontrivial topological invariant in the topological insulator-ferromagnet tri-junction systems, for which a semiclassical approximation fails to describe the topological phase. Also, our approach enables us to study effects of electron-electron interactions and impurity scattering on topological insulators with spatial inhomogeneity which gives rise to the Axion electrodynamics responses.Comment: 15 pages, 3 figure