The Papers of Samuel Van Valkenburg

Samuel Van Valkenburg was a Professor of Georgraphy and Climatology at Clark University from 1926 to 1976. He also was Director of the Graduate School of Geography. His papers consists of correspondence and tapes of lectures

An Investigation of Intraspecific Variation of Bolboschoenus Maritimus (Alkali Bulrush)

Wetlands are unique because although they are highly productive, they are often species poor. Previous research suggests intraspecific genetic variation of traits within species may be driving high functioning. If genetic differences influence functional traits, then this relationship could explain the high functioning of wetland systems despite low species diversity. We examined trait variation among different genotypes of the wetland plant Bolboschoenus martimus (alkali bulrush). We collected rhizomes from wetlands in Montana, Arizona, and Utah and grew 5 genotypes from these various sites in a common garden experiment for 22 weeks. We measured above ground and belowground traits which include maximum stem height, stem density, specific leaf area, relative growth rate, number of inflorescences, above and below ground carbon to nitrogen ratio, number of new rhizomes, and biomass. These traits mitigate for drought, water saturation, nutrient scarcity, shading, and crowding. We found some of these traits, specifically stem density and number of inflorescence were significantly different between genotypes. Understanding the level of functional trait diversity required to maintain high levels of function not only helps us better understand the relationship between intraspecific biodiversity and ecosystem functioning. Furthermore, understanding trait variation among genotypes of single species can help with restoration efforts when a specific species is needed to improve a wetland ecosystem

Yoga and the Effects on Balance, Hamstring Flexibility, and Blood Pressure

Yoga is an ancient form of exercise and meditation that has recently gained popularity in the United States. Medical research regarding the benefits of yoga, however, continues to be in demand. The purpose of this study was to determine the effects of yoga on normal, healthy individuals. The focus of this study revolved around balance, hamstring flexibility, and blood pressure changes after six weeks of yoga training. Eighteen normal, healthy individuals between 20-33 years of age participated in this study. Subjects were assessed using the NeuroCom®Balance Master test for rhythmic weight shift (RWS), the Functional Reach Test (FRT), the measure of blood pressure (BP), the Sit-and-Reach Test (SRT), and the Single Limb Stance Timed Test (SLST). The yoga group performed a random combination of 14 asanas in a six-week yoga-training program that met for 45 minutes, three times per week. The walking group (control group) walked below their target heart rates and performed basic hamstring stretching three times per week for six weeks. Paired samples t-tests indicated significance for diastolic blood pressure (Sig. .04) and on-axis velocity RWS anterior-posterior (Sig .. 048) for the yoga group and for SLST on the left with eyes closed (Sig .. 005) for the walking group. Wilcoxen tests indicated significance for the yoga group in the SRT (Sig .. 003) and SLST on the right with eyes open (Sig .. 003) and eyes closed (Sig .. 021). These findings provide evidence that the practice of yoga is beneficial in improving physical well-being

Attacking the Tax Gap

Today a radio station played something extraordinary, an Internal Revenue Service (IRS) advertisement promoting taxes. Help someone with their taxes, there is no telling what the returns may be. At last, after five years of American Bar Association (ABA) research, the Tax Reform Act of 1986 (TRA\u2786), and countless private studies, the IRS seems to be taking an affirmative step in dealing with tax noncompliance. Moreover, the IRS realizes the answer lies in the attitudes of the taxpayers, as well as in the collection system itself. This news is truly exciting. Specific arenas of taxation like gift and estate tax, depreciation, or capital gains are complex and contain policy implications. In the arena of tax compliance, the fairness of laws is assumed and the tax owed is merely collected. Compliance is a politically safer way to attack the national deficit because it promotes economic good and does not directly cut government services. While the complexity of the other tax arenas requires attention, not even administratively simple taxes can be raised against the hostility of everybody concerned, no matter how rigid the controls. United States citizens typically follow the tax laws. Eighty-one percent reported the tax owed on legal income in 1987. Still, noncompliance exceeded $100 billion for the 1987 tax year. The tax gap is the difference between taxes paid and taxes owed (if all taxpayers filed complete and accurate returns and paid all of the taxes)