The Real Chevalley Involution

We consider the Chevalley involution in the context of real reductive groups. We show that if G(R) is the real points of a connected reductive group, there is an involution, unique up to conjugacy by G(R), taking any semisimple element to a conjugate of its inverse. As applications we give a condition for every irreducible representation of G(R) to be self-dual, and to the Frobenius Schur indicator for such groups

Duality for nonlinear simply laced groups

Let G be a nonlinear double cover of the real points of a connected reductive complex algebraic group with simply laced root system. We establish a uniform character multiplicity duality theory for the category of Harish-Chandra modules for G.Comment: 51 pages, 1 figur

Using Market-Based Spectrum Policy to Promote the Public Interest

With the increasing demand for spectrum to accommodate emerging technologies, and the discovery that higher frequencies are usable, the FCC has replaced its reliance on administrative mechanisms for allocating spectrum with a more flexible, market-based approach. The FCC can best accomplish its mission of promoting the public interest by continuing to rely on competitive market forces and by establishing a clear and consistent paradigm for approaching allocation, assignment, usage, and other policies. Such a paradigm envisions an FCC that would actively monitor spectrum to remedy situations in which it is not used to its full value; establish mechanisms to reduce new services\u27 need for immediate secondary market transactions; set and enforce minimally restrictive baseline rules governing interference and health effects; maximize the amount of spectrum available to users; and, in some cases, intervene in markets to correct significant market failures

Oxalic, glyoxalic and pyruvic acids in eastern Pacific Ocean waters

A sensitive high performance liquid chromatographic (HPLC) technique has been used to determine the concentration and distribution of several α-keto acids and oxalic acid in seawater samples from a station (28°29′N, 128°38′W) in the eastern Pacific Ocean. Glyoxalic, pyruvic and oxalic acids were found to be present. Although the pyruvic acid profile at this station was in general featureless, the profiles for glyoxalic and oxalic acids showed variations which could be attributed to both primary production and heterotropic activity. Surface waters were found to have a combined concentration of glyoxalic and oxalic acids of ∼300 to 400 nm/liter which makes these two compounds some of the more abundant organic constituents of surface ocean waters

Exploring How Social Media Can Be Used to Promote Space Awareness: A Case Study of the Yuri\u27s Night Web 2.0

Despite the importance of social media as an inexpensive and efficient means of communication, it is not clear to what degree space advocacy groups are making a strong organized effort to use the resources available to them. Moreover, there is no previous literature that specifically examines the use of social media tools by space organizations. This study seeks to start a larger dialog regarding how the space advocacy community can make use of these tools to promote their mission. Using a case study approach, this article focuses specifically on the organization of Yuri’s Night to explore how this group is using social media to accomplish its mission of building general space awareness. In addition, this article evaluates the organization’s social media presence as well as the role social media has played in the organization’s ability to accomplish its mission. Other space advocacy groups can use the lessons learned here to improve their own social media strategies

Lifting representations of finite reductive groups: a character relation

Given a connected reductive group $\tilde{G}$ over a finite field $k$, and a semisimple $k$-automorphism $\varepsilon$ of $\tilde{G}$ of finite order, let $G$ denote the connected part of the group of $\varepsilon$-fixed points. Then there exists a lifting from packets of representations of $G(k)$ to packets for $\tilde{G}(k)$. In the case of Deligne-Lusztig representations, we show that this lifting satisfies a character relation analogous to that of Shintani.Comment: Minor errors corrected, proofs streamlined. Main result slightly generalized, restated to emphasize analogy with stabilit

Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores

Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis

Hydrophilic polymer embolism identified in brain tumor specimens following Wada testing: A report of 2 cases

Hydrophilic polymers are commonly used as coatings on intravascular medical devices. As intravascular pro-cedures continue to increase in frequency, the risk of embolization of this material throughout the body has become evident. These emboli may be discovered incidentally but can result in serious complications includ-ing death. Here, we report the first two cases of hydrophilic polymer embolism (HPE) identified on brain tu-mor resection following Wada testing. One patient experienced multifocal vascular complications and diffuse cerebral edema, while the other had an uneventful postoperative course. Wada testing is frequently per-formed during preoperative planning prior to epilepsy surgery or the resection of tumors in eloquent brain regions. These cases demonstrate the need for increased recognition of this histologic finding to enable fur-ther correlation with clinical outcomes