Results and speculations concerning Comer relation algebras and the flexible atom conjecture

We study some finite integral symmetric relation algebras whose forbidden cycles are all 2-cycles. These algebras arise from a finite field construction due to Comer. We consider conditions that allow other finite algebras to embed into these Comer algebras, and as an application give the first known finite representation of relation algebra $34_{65}$, one of whose atoms is flexible. We conclude with some speculation about how the ideas presented here might contribute to a proof of the flexible atom conjecture

Corruption, Optimal Taxation and Growth

How does the presence of corruption affect the optimal mix between consumption and income taxation? In this paper we examine this issue using a simple neoclassical growth model, with a self-seeking and corrupt public sector. We find that the optimal tax mix in a corrupt economy is one that relies more heavily upon consumption taxes than on income taxes, relative to an economy without corruption. Our model also allows us to investigate the effect of corruption on the optimal size of government, and our results indicate that the optimal size of government balances the wishes of the corrupt public sector for a larger government, and so greater opportunities for corruption, with those in the private sector who prefer a smaller government. Not surprisingly, the optimal size of government is smaller in an economy with corruption than in one without corruption.endogenous growth, corruption, taxation

Status of Containerized Forest Seedling Research in Minnesota

The paper describes a series of containerized seedling studies in Minnesota. Descriptions of the tubeling, styroblock plug, book planter plug and Japanese paper pot systems are provided. Survival results of field plantings with the various systems under a range of conditions are given

Crude awakening: behind the surge in oil prices

The first few months of 2008 saw crude oil prices breach one barrier after another. They topped $100 a barrel for the first time on Feb. 19, then rose past$103.76 about two weeks later, surpassing the previous inflation-adjusted peak, established in 1980. In April and early May, oil prices pushed past $110 and then$120 a barrel and beyond. ; These milestones reflect a new era in oil markets. After the tumult of the early 1980s, prices remained relatively tame for two decades - in both real and nominal terms. This long stretch of stability ended in 2004, when oil topped $40 a barrel for the first time, then embarked on a steep climb that continued into this year. ; Modern economies run on oil, so it's important to understand how recent years - with their surging prices - differ from the preceding two decades. A good starting point is strong demand, which has pushed world oil markets close to capacity. New supplies haven't kept up with this demand, fueling expectations that oil markets will remain tight for the foreseeable future. A weakening dollar has put upward pressure on the price of a commodity that trades in the U.S. currency. And because a large share of oil production takes place in politically unstable regions, fears of supply disruptions loom over markets. ; These factors have fed the steady, sometimes swift rise of oil prices in recent years. Their persistence suggests the days of relatively cheap oil are over and the global economy faces a future of high energy prices. How they play out will shape oil markets - and determine prices - for years to come.Petroleum products - Prices ; Petroleum industry and trade ; Organization of Petroleum Exporting Countries ; Dollar, American

On the Causal Mechanisms of Stuttering

Stuttering is one of the most common speech disorders. However, the etiology is poorly understood, and is likely to be heterogeneous. The aim of this thesis was to clarify causal mechanisms, focusing the brain. The project included theoretical development based on published data, and a broad approach of explorative studies and testing of hypotheses. The theoretical work focused the basal ganglia, leading to a model based on the dual premotor systems hypothesis (G. Goldberg, 1985, 1991), which defines two parallel premotor systems: the medial (the basal ganglia and the SMA), and the lateral (the lateral premotor cortex and the cerebellum). Stuttering is suggested to be caused by a disturbance of the medial system, in most cases in the basal ganglia. The core dysfunction is proposed to be impaired "go-signals" from the medial system, supposed to trigger the next motor segment in speech. According to this model, under some conditions speech control is shifted from the medial to the lateral system, thereby bypassing the dysfunction and resulting in fluent speech. The lateral system is suggested to be active when speech is combined with sensory input, like chorus speech or metronome. Also the effect of altered auditory feedback in reducing stuttering is proposed to be based on this mechanism. It seems as the lateral system is able control speech timing without sensory input, but that this demands increased attention to some particular aspect of speech, as occurs in imitation of dialects, exaggerated rhythm, reduced speech rate, or role play. Also singing is suggested to be based on the lateral system. Superfluous muscular activation accompanying stuttering may be a type of dystonia: involuntary contractions related to the basal ganglia disturbance. The high prevalence of stuttering at age 2.5 to 3 years is proposed to reflect a normally occurring peak in the number of dopamine receptors at this age. A total of 35 stuttering adults participated. Two studies, of copper metabolism and "startle prepulse inhibition", did not indicate any significant differences in comparison with matched controls. It has previously been reported that stuttering may be associated with increased neuromuscular reactivity, measured as exaggerated eye-blink in response to noise. This aspect was investigated. The stuttering group showed somewhat stronger eye-blink, though not statistically significant. Strong eye-blink was not related to anxiety, but was clearly related to low calcium, which is known to increase the excitability of the nervous system. The stuttering group showed somewhat lower calcium, and a weak tendency towards more severe stuttering in case of low calcium. It is possible that low calcium can increase the severity of stuttering in some cases. A subgroup reported some traits of childhood ADHD, and this group typically also reported neurological incidents before the onset of stuttering. The subgroup without traits of ADHD typically reported having stuttering relatives but no neurological incident

Spontaneous breaking of rotational symmetry in superconductors

We show that homogeneous superconductors with broken spin/isospin symmetry lower their energy via a transition to a novel superconducting state where the Fermi-surfaces are deformed to a quasi-ellipsoidal form at zero total momentum of Cooper pairs. In this state, the gain in the condensation energy of the pairs dominates over the loss in the kinetic energy caused by the lowest order (quadrupole) deformation of Fermi-surfaces from the spherically symmetric form. There are two energy minima in general, corresponding to the deformations of the Fermi-spheres into either prolate or oblate forms. The phase transition from spherically symmetric state to the superconducting state with broken rotational symmetry is of the first order.Comment: 5 pages, including 3 figures, published versio

W(h)ither the Tax Gap?

For decades, policy makers and politicians have railed against the “tax gap,” or the difference between what taxpayers are legally obligated to pay in taxes and what they actually pay in taxes. To close the gap, Congress has instituted numerous reforms with varying degrees of success. Notwithstanding these efforts, the tax gap has largely remained intact, and, if anything, it has gradually grown over the last several decades. However, the tax gap may well begin to diminish in size (or “wither” away), if not immediately then over time. Three developments will help narrow the tax gap’s size. First, the ubiquity of credit cards, debit cards, and smartphone payment apps has purged cash—the erstwhile driving engine of the tax gap—from its use in many economic transactions. Second, the availability of third-party sources of information, combined with the universal use of computerization to store, access, and analyze information, has significantly curtailed a taxpayer’s ability to hide income here in the United States or overseas. Third, broad economic trends such as concentration and globalization have generated a workforce dynamic in which taxpayers generally are employed by large business enterprises (where individual tax compliance is fairly high) rather than in traditional mom-and-pop businesses (where individual tax compliance is typically low). The implications associated with a lower tax gap are vast. Even beyond the usual considerations associated with greater tax compliance (e.g., increased revenues, reduced noncompliance-induced inefficiencies, and improved horizontal and vertical equity of tax burdens), taxpayers would experience a shift in the labor market and an adjustment in the prices paid for consumer goods and services. Also, rather than conducting audits and deterring noncompliance, the Internal Revenue Service (IRS) would be able to dedicate a greater share of its limited resources to other pressing agenda items, such as assisting taxpayers in their compliance endeavors. There are, of course, other countervailing economic trends that may subvert the forces that will act to reduce the tax gap, so its future path remains highly uncertain (and hence the alternative use of “whither”). Also, for a whole host of reasons, especially reductions in IRS funding, the tax gap will not be closed anytime soon. Nevertheless, the tide against tax noncompliance may finally be turning

The Internal Revenue Code and Automobiles: A Case Study of Taxpayer Noncompliance

Over the last decade, the tax gap — the difference between what taxpayers owe in taxes and what they actually pay — has remained significantly large. A contributory factor to the tax gap’s size is the fact that many taxpayers mischaracterize the tax treatment of their automobile expenses and the receipt of other employer-provided fringe benefits. This analysis explores the reasons for this phenomenon and then proposes reforms that will make taxpayers more compliant, helping to reduce the tax gap’s size. Although these reforms admittedly would not solve all of the nation’s tax noncompliance woes, they would help preserve the income tax base and minimize economic distortions