Stock Market Yields and the Pricing of Municipal Bonds

This paper proposes an alternative to the traditional model for explaining the spread between taxable and tax-exempt bond yields. This alternative model is a special case of a general class of clientele models of portfolio choice and asset market equilibrium. In particular, we consider a setting with two types of investors, a taxable investor and a tax-exempt investor, who hold specialized bond portfolios. The tax-exempt investor holds only taxable bonds, and the taxable investor holds only tax-exempt bonds. Both investors hold equity, and the taxable and tax-exempt bond markets are linked through the equilibrium conditions governing equity holding and bond holding for each type of investor. In contrast to the traditional model, this alternative model has the potential to explain the small observed spread between taxable and tax-exempt yields. In addition, this model predicts that the yield spread between taxable and tax-exempt bonds should be an increasing function of the dividend yield on corporate stocks. Although the substantial changes in the tax code during the last four decades complicate the testing of this model, we find some support for the predicted relationship between the equity dividend yield and the yield spread between taxable and tax-exempt bonds.

Countering the Norm, (Re)authoring Our Lives: The Promise Counterstorytelling Holds as a Research Methodology With LGBTQ Youth and Beyond

Counterstorytelling, a methodology that is rooted in critical race theory, is undergirded by principles that are beneficial to understanding the experiences of lesbian, gay, bisexual, transgender, and queer-identified (LGBTQ) young people from an intersectional perspective. Counterstorytelling holds promise as a method that creates opportunities for individual transformation and resistance to dominant narratives among young people facing systemic oppression. This article outlines the design and implementation of a counterstorytelling study with LGBTQ youth and reflects on the value and associated challenges of counterstorytelling as a participatory research method

GABAergic compensation in connexin36 knock-out mice evident during low-magnesium seizure-like event activity

Gap junctions within the cerebral cortex may facilitate cortical seizure formation by their ability to synchronize electrical activity. To investigate this, one option is to compare wild-type (WT) animals with those lacking the gene for connexin36 (Cx36 KO); the protein that forms neuronal gap junctions between cortical inhibitory cells. However, genetically modified knock-out animals may exhibit compensatory effects; with the risk that observed differences between WT and Cx36 KO animals could be erroneously attributed to Cx36 gap junction effects. In this study we investigated the effect of GABAA-receptor modulation (augmentation with 16 μM etomidate and blockade with 100 μM picrotoxin) on low-magnesium seizure-like events (SLEs) in mouse cortical slices. In WT slices, picrotoxin enhanced both the amplitude (49% increase, p = 0.0006) and frequency (37% increase, p = 0.005) of SLEs; etomidate also enhanced SLE amplitude (18% increase, p = 0.003) but reduced event frequency (25% decrease, p < 0.0001). In Cx36 KO slices, the frequency effects of etomidate and picrotoxin were preserved, but the amplitude responses were abolished. Pre-treatment with the gap junction blocker mefloquin in WT slices did not significantly alter the drug responses, indicating that the reduction in amplitude seen in the Cx36 KO mice was not primarily mediated by their lack of interneuronal gap junctions, but was rather due to pre-existing compensatory changes in these animals. Conclusions from studies comparing seizure characteristics between WT and Cx36 KO mice must be viewed with a degree of caution because of the possible confounding effect of compensatory neurophysiological changes in the genetically modified animals

Supersymmetric solutions to Euclidean Romans supergravity

We study Euclidean Romans supergravity in six dimensions with a non-trivial Abelian R-symmetry gauge field. We show that supersymmetric solutions are in one-to-one correspondence with solutions to a set of differential constraints on an SU(2) structure. As an application of our results we (i) show that this structure reduces at a conformal boundary to the five-dimensional rigid supersymmetric geometry previously studied by the authors, (ii) find a general expression for the holographic dual of the VEV of a BPS Wilson loop, matching an exact field theory computation, (iii) construct holographic duals to squashed Sasaki-Einstein backgrounds, again matching to a field theory computation, and (iv) find new analytic solutions.Comment: 31 pages; v2: published version (with reference added

Ammonia uptake and release in the MnX₂–NH₃ (X = Cl, Br) systems and structure of the Mn(NH₃)nX₂ (n = 6, 2) ammines

Hexa-ammine complexes, Mn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;X&lt;sub&gt;2&lt;/sub&gt; (X = Cl, Br), have been synthesized by ammoniation of the corresponding transition metal halide and characterized by Powder X-ray diffraction (PXRD) and Raman spectroscopy. The hexa-ammine complexes are isostructural (Cubic,Fm-3m, Z = 4; a = 10.2742(6) Å and 10.527(1) Å for X = Cl, Br respectively). Temperature programmed desorption (TPD) demonstrated that ammonia release from Mn(NH&lt;sub&gt;3&lt;/sub&gt;)&lt;sub&gt;6&lt;/sub&gt;X&lt;sub&gt;2&lt;/sub&gt; complexes occurred in three stages corresponding to the release of 4, 1 and 1 NH&lt;sub&gt;3&lt;/sub&gt; equivalents respectively. The chloride and bromide both exhibit a deammoniation onset temperature below 323 K. The di-ammoniates from the first desorption step were isolated during TPD measurements and their crystal structures determined by Rietveld refinement against PXRD data (X = Cl: orthorhombicCmmm, a = 8.1991(9) Å, b = 8.2498(7) Å, c = 3.8212(4) Å, Z = 2; X = Br: orthorhombic Pbam, a = 6.0109(5) Å, b = 12.022(1) Å, c = 4.0230(2) Å, Z= 2)

Supersymmetric gauge theories on squashed five-spheres and their gravity duals

We construct the gravity duals of large N supersymmetric gauge theories defined on squashed five-spheres with SU(3) x U(1) symmetry. These five-sphere backgrounds are continuously connected to the round sphere, and we find a one-parameter family of 3/4 BPS deformations and a two-parameter family of (generically) 1/4 BPS deformations. The gravity duals are constructed in Euclidean Romans F(4) gauged supergravity in six dimensions, and uplift to massive type IIA supergravity. We holographically renormalize the Romans theory, and use our general result to compute the renormalized on-shell actions for the solutions. The results agree perfectly with the large N limit of the dual gauge theory partition function, which we compute using large N matrix model techniques. In addition we compute BPS Wilson loops in these backgrounds, both in supergravity and in the large N matrix model, again finding precise agreement. Finally, we conjecture a general formula for the partition function on any five-sphere background, which for fixed gauge theory depends only on a certain supersymmetric Killing vector.Comment: 63 pages, no figures; v2: minor corrections and reference adde

INCORPORATING GOVERNMENT PROGRAM PROVISIONS INTO A MEAN-VARIANCE FRAMEWORK

E-V studies traditionally have relied on historical data to calculate returns and variance. Historical data may not fully reflect current conditions, particularly when decisions involve government-supported crops. This paper presents a method for calculating mean and variance using subjectively-estimated data. The method is developed for both government-supported and non-program crops. Comparisons to alternative methods suggest the approach provides reasonable accuracy.Agricultural and Food Policy,

Neuro-Anatomical Changes of Carbon Monoxide Poisoning on Advanced Imaging: A Literature Review

Carbon monoxide (CO) poisoning is a major public health issue in the United States that accounts for approximately 50% of poisoning cases in the nation each year and around 50,000 emergency room visits. In most instances of CO poisoning, the culprit is a malfunctioning or poorly tended heating system within the home or, occasionally, commercial building, which causes the system to leak this hazardous gas. One of the more insidious aspects of CO poisoning is that the gas is odorless and colorless, and victims of CO poisoning often do not realize that there is a problem until they begin to experience the effects of poisoning and have no choice but to seek medical attention. Unfortunately, many victims of CO poisoning die before they are able to seek treatment. This paper makes use of a qualitative, systematic literature review to examine the four major parts of the brain that are most severely affected by CO poisoning. Overall, the literature review showed that the white matter, globus pallidus, basal ganglia, and cortex are the parts of the brain most severely impacted by CO poisoning. While many CO poisoning victims do make it to the hospital on time and are treated, they may nonetheless suffer long-term neurological consequences as a result of their exposure. As such, CO poisoning is a major public health issue