Evaluation of Plantings for Wildlife on a Power Line Right of Way in Southern Arkansas

The combination of types of land preparation and species of plants seeded along a power line right-of-way was evaluated in terms of the effects upon wildlife. Relative population densities of plants, birds, and mammals were determined for each of the areas under study. A study of the reduction in maintenance costs in relation to the initial investment for preparation and seeding of the land was mad

Labor Force Participation Elasticities of Women and Secondary Earners within Married Couples

Labor supply elasticities are often used to evaluate the effect of changes in tax rates on the total hours worked in the economy. Historically, married women have tended to have larger labor supply elasticities than their spouses because they were the secondary earners in a couple. However, those elasticities have fallen sharply in recent decades—a decline that has been attributed to greater labor force participation rates and increased career orientation among married women. Indeed, a growing share of wives earn more than their husbands, raising the question whether a person’s sex or relative earnings is the relevant factor affecting the sensitivity of participation to wage and tax rates. In this paper, we use administrative data to examine whether women or lower-earning spouses have larger labor supply elasticities. We present descriptive evidence on the share of women who are the primary earner and the frequency of transitions into and out of employment by sex and relative earnings. We find that lower earning spouses are more likely to start and stop working than women, except when a couple starts a family. We then model an individual’s work decision using a dynamic probit model to isolate the labor supply response to changes in tax rates. We estimate that the participation elasticity with respect to the net-of-tax rate of the secondary earner—the spouse who typically has lower earnings—is about 0.03, slightly higher than that for women, though both of these overall elasticities are small. Participation elasticities with respect to income for both women and secondary earners are effectively zero. Our estimates are robust to several alternative models, including alternative specifications of secondary earner

Evidence for Stellar Streaming in the Cores of Elliptical Galaxies: A Kinematic Signature of Mergers?

We present evidence for non-Gaussian velocity fields within the cores of luminous elliptical galaxies. This evidence is based upon high signal-to-noise, medium-resolution spectroscopy of the cores of early-type members of the Virgo and Coma clusters obtained with the WIYN 3.5-m telescope. The Virgo data were acquired using an integral-field unit (DensePak) allowing the velocity field to be sampled over a variety of spatial scales. The Coma data were obtained through single, 2-arcsec diameter fibers. The cross-correlation profiles of luminous ellipticals show considerable structure, often having several features with amplitudes as high as 10% that of the cross-correlation peak itself. This structure is most obvious within a radius of 1.5 arcsec (at Virgo), or < 100 pc, and is nearly undetectable when the data are binned over R < 15 arcsec, or < 1 kpc. Similar features are found in the single-fiber spectra of the luminous ellipticals in the Coma Cluster suggesting they are ubiquitous to giant ellipticals. Interesting, only the most luminous elliptical galaxies show this phenomena; the central regions of lower luminosity ellipticals have regular, Gaussian-like profiles. We interpret this kinematic structure as ``stellar streaming'' and suggest that this phenomena could be a relic signature of the merger history of luminous elliptical galaxies.Comment: Latex, 5 pages, 2 figure

Salary Dispersion and Team Performance in the National Basketball Association

This paper explores the relationship between salary dispersion in the National Basketball Association (NBA) and team performance. Team performance will be measured by regular season win totals as well as playoff performance. I hypothesize that teams with higher salary dispersion typically perform better because of superstars in the NBA. Superstars are more effective in basketball than in any other sport because of rules inherent to the game. They also create high salary dispersions on their respective teams, and being superstars, they contribute largely to team success. This study will encompass all 30 NBA teams over the past 20 NBA seasons, 1995-96 to 2015-16

Resources in Europe of interest to mathematics teachers,

Thesis (M.A.)--Boston University. This thesis was written in conjunction with Dennis J. Roberts, Mary Lee McLaughlin and Robert F. Pierce.Statement of the problem: It is the purpose of this thesis to formulate plans for a guided tour throughout Western Europe for secondary-school teachers with emphasis on present and past mathematical and allied science contributions. This study will serve as an answer to four fundamental questions: 1. What are the resources available in Europe of value to mathematics teachers? 2. From the standpoint of marginal utility, which of these would be the most important? 3. where are they to be found? 4. How long would it take to see each of them profitably in a limited amount of time? [TRUNCATED

Paradigms for computational nucleic acid design

The design of DNA and RNA sequences is critical for many endeavors, from DNA nanotechnology, to PCR‐based applications, to DNA hybridization arrays. Results in the literature rely on a wide variety of design criteria adapted to the particular requirements of each application. Using an extensively studied thermodynamic model, we perform a detailed study of several criteria for designing sequences intended to adopt a target secondary structure. We conclude that superior design methods should explicitly implement both a positive design paradigm (optimize affinity for the target structure) and a negative design paradigm (optimize specificity for the target structure). The commonly used approaches of sequence symmetry minimization and minimum free‐energy satisfaction primarily implement negative design and can be strengthened by introducing a positive design component. Surprisingly, our findings hold for a wide range of secondary structures and are robust to modest perturbation of the thermodynamic parameters used for evaluating sequence quality, suggesting the feasibility and ongoing utility of a unified approach to nucleic acid design as parameter sets are refined further. Finally, we observe that designing for thermodynamic stability does not determine folding kinetics, emphasizing the opportunity for extending design criteria to target kinetic features of the energy landscape