This study examines the relationship between board diversity and firm value for Fortune 1000 firms. Board diversity is defined as the percentage of women, African Americans, Asians, and Hispanics on the board of directors. This research is important because it presents the first empirical evidence examining whether board diversity is associated with improved financial value. After controlling for size, industry, and other corporate governance measures, we find significant positive relationships between the fraction of women or minorities on the board and firm value. We also find that the proportion of women and minorities on boards increases with firm size and board size, but decreases as the number of insiders increases.

Manuscript Type: EmpiricalResearch Question/Issue: We examine the business case for the inclusion of women and ethnic minority directors on the board. Specifically, we investigate the relationship between the number of women directors and the number of ethnic minority directors on the board and important board committees and financial performance measured as return on assets and Tobin's Q. Research Findings/Insights: We do not find a significant relationship between the gender or ethnic diversity of the board, or important board committees, and financial performance for a sample of major US corporations. Our evidence also suggests that the gender and ethnic minority diversity of the board and firm financial performance appear to be endogenous. Theoretical/Academic Implications: Reasonable theoretical arguments drawn from resource dependence theory, human capital theory, agency theory, and social psychology suggest that gender and ethnic diversity may have either a positive, negative, or neutral effect on the financial performance of the firm. Our statistical analysis supports the theoretical position of no effect, either positive or negative. Our results are consistent with a contingency explanation because the effect of the gender and ethnic diversity of the board may be different under different circumstances at different times. Over several companies and time periods, the results could offset to produce no effect. Practitioner/Policy Implications: The results of our analysis do not support the business case for inclusion of women and ethnic minorities on corporate boards. However, we find no evidence of any negative effect either. Our evidence implies that decisions concerning the appointment of women and ethnic minorities to corporate boards should be based on criteria other than future financial performance.

The cellular mechanisms underlying typical absence seizures, which characterize various idiopathic generalized epilepsies, are not fully understood, but impaired GABAergic inhibition remains an attractive hypothesis. In contrast, we show here that extrasynaptic GABAA receptor–dependent ‘tonic’ inhibition is increased in thalamocortical neurons from diverse genetic and pharmacological models of absence seizures. Increased tonic inhibition is due to compromised GABA uptake by the GABA transporter GAT–1 in the genetic models tested, and GAT–1 is critical in governing seizure genesis. Extrasynaptic GABAA receptors are a requirement for seizures in two of the best characterized models of absence epilepsy, and the selective activation of thalamic extrasynaptic GABAA receptors is sufficient to elicit both electrographic and behavioural correlates of seizures in normal animals. These results identify an apparently common cellular pathology in typical absence seizures that may have epileptogenic significance, and highlight novel therapeutic targets for the treatment of absence epilepsy.

The pineal gland plays an essential role in vertebrate chronobiology by converting time into a hormonal signal, melatonin, which is always elevated at night. Here we have analyzed the rodent pineal transcriptome using Affymetrix GeneChip technology to obtain a more complete description of pineal cell biology. The effort revealed that 604 genes (1,268 probe sets) with Entrez Gene identifiers are differentially expressed greater than 2-fold between midnight and mid-day (false discovery rate <0.20). Expression is greater at night in ϳ70%. These findings were supported by the results of radiochemical in situ hybridization histology and quantitative real time-PCR studies. We also found that the regulatory mechanism controlling the night/ day changes in the expression of most genes involves norepinephrine-cyclic AMP signaling. Comparison of the pineal gene expression profile with that in other tissues identified 334 genes (496 probe sets) that are expressed greater than 8-fold higher in the pineal gland relative to other tissues. Of these genes, 17% are expressed at similar levels in the retina, consistent with a common evolutionary origin of these tissues. Functional categorization of the highly expressed and/or night/day differentially expressed genes identified clusters that are markers of specialized functions, including the immune/inflammation response, melatonin synthesis, photodetection, thyroid hormone signaling, and diverse aspects of cellular signaling and cell biology. These studies produce a paradigm shift in our understanding of the 24-h dynamics of the pineal gland from one focused on melatonin synthesis to one including many cellular processes.A defining feature of the pineal gland is a 24-h rhythm in melatonin synthesis. Melatonin provides vertebrates with a circulating signal of time and is essential for optimal integration of physiological functions with environmental lighting on a daily and seasonal basis (1-4).The melatonin rhythm in mammals is driven by a circadian clock located in the suprachiasmatic nucleus (SCN), 13 which is hard-wired to the pineal gland by a polysynaptic pathway that courses through central and peripheral neuronal structures. The pineal gland is innervated by projections from the superior cervical ganglia (SCG) in the form of a dense network of catecholamine-containing sympathetic fibers. Activation of the SCN 3 pineal pathway occurs at night and results in the release

Does hedging add value to the firm, and if so, is the source of the added value consistent with hedging theory? We investigate jet fuel hedging behavior of firms in the US airline industry during 1992-2003 to examine whether such hedging is a source of value for these companies. We illustrate that the investment and financing climate in the airline industry conforms well to the theoretical framework of Froot, Scharfstein, and Stein (1993). In general, airline industry investment opportunities correlate positively with jet fuel costs, while higher fuel costs are consistent with lower cash flow. Given that jet fuel costs are hedgeable, airlines with a desire for expansion may find value in hedging future purchases of jet fuel. Our results show that jet fuel hedging is positively related to airline firm value. The coefficients on the hedging variables in our regression analysis suggest that the "hedging premium" is greater than the 5% documented in Allayannis and Weston (2001), and might be as large as 10%. We find that the positive relation between hedging and value increases in capital investment, and that most of the hedging premium is attributable to the interaction of hedging with investment. This result is consistent with the assertion that the principal benefit of jet fuel hedging by airlines comes from reduction of underinvestment costs. Copyright (c) 2006 Financial Management Association International.

Vibrational modes are assigned to the Raman bands of 1-and 2-methylimidazole. Assignments are based on a review of the literature assignments of imidazole, 1-methylimidazole and 4(5)-methylimidazole supplemented by Raman depolarization studies of 1.0 M solutions of 1-and 2-methylimidazole. Raman shifts observed for Ndeuteration of 2-methylimidazole are also considered. INTRODUCTIONThe study of imidazole and its isomers is important biologically because of its presence in the structures of the nucleic acid bases adenine and guanine and in the amino acid histidine. The structures of 1-methylimidazole (I) and 2-methylimidazole (II) (the subjects of this study) are given in Fig. 1. The structure of imidazole (III) and the 4(5)-methylimidazole tautomers (IV) are also provided. Metal complexes of imidazoles have been used as models of metalloproteins,1h6 and resonance Raman spectroscopy has been suggested as a means of selectively studying the metalÈhistidine interactions in metalloproteins.4,7 The biological behavior of imidazole-containing species is predominantly due to the Lewis base behavior of the "pyridineÏ (N-3) nitrogen. This same property a †ects how imidazole interacts with metal surfaces. As a result, these compounds are useful as anti-corrosion agents on copper8h10 and their potential for use as adhesion promoters in electric devices and metalÈpolymer (epoxy) composites has been investigated.10,11Surface-enhanced Raman scattering (SERS) of imidazole has recently been studied and used to describe the orientation of adsorbed imidazole at silver electrode surfaces.12 Analysis of adsorption-induced wavenumber shifts and application of Raman surface selection rules to changes in the relative intensities of in-plane and out-of-plane vibrational bands support adsorption through the imidazole pyridine nitrogen lone pair. The data also suggest a tilted orientation of the molecule positive of the potential of zero charge (PZC) with the molecules becoming more vertical at potentials near the PZC. The application of SERS surface selection rules to methyl vibrational bands, in this laboratory, has been used very e †ectively to estimate orientations of alcohols and alkanethiols adsorbed to Ag and Au surfaces.13 The present study was undertaken to verify the adsorption behavior of imidazole on Ag electrodes by using the methyl group in 1-and 2-methylimidazole as a SERS orientational pointer.14 4(5)-Methylimidazole was not studied because of complications resulting from the presence of two tautomeric species (4-and 5-methylimidazole).Analysis of the SERS data in the determination of orientation requires accurate assignment of observed Raman vibrational modes. While the vibrational behavior of imidazole has been studied extensively (see Ref. 12 for a review), the methylimidazoles have not been studied as exhaustively. This paper reports work undertaken to determine vibrational mode assignments of 1-and 2-methylimidazole which are adequate for the analysis of SERS data.

Recent rocket probe, barium cloud and radar measurements conducted during equatorial spread F conditions are interpreted in terms of a Rayleigh‐Taylor gravitational instability operating on the bottomside of the F peak. The persistent theoretical problems associated with strong radar echoes typically observed in patch‐like structures at high altitudes are explained in terms of regions of depleted plasma density which bouyantly rise against the gravitational field.

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