The Compulsive Gambler Process

In the compulsive gambler process there is a finite set of agents who meet pairwise at random times ($i$ and $j$ meet at times of a rate-$\nu_{ij}$ Poisson process) and, upon meeting, play an instantaneous fair game in which one wins the other's money. We introduce this process and describe some of its basic properties. Some properties are rather obvious (martingale structure; comparison with Kingman coalescent) while others are more subtle (an "exchangeable over the money elements" property, and a construction reminiscent of the Donnelly-Kurtz look-down construction). Several directions for possible future research are described. One -- where agents meet neighbors in a sparse graph -- is studied here, and another -- a continuous-space extension called the {\em metric coalescent} -- is studied in Lanoue (2014)

Teaching the Presidential Debates: Helping Students to Understand and Overcome Biases during Presidential Election Campaigns David J. Lanoue Columbus State University Gregory Domin Columbus State University Abstract

In this paper, we propose ideas for teaching presidential debates within the university classroom setting. In particular, we explore methods for helping students to break through partisan and ideological barriers that might inhibit their understanding of and ability to analyze candidates’ messages. If debates are to fulfill their original purpose of creating a more informed and responsible electorate, it is first essential that viewers give each nominee a full and fair hearing. We begin our discussion with a brief history of presidential debates, emphasizing both the presentations of the candidates and how those presentations have been distorted by media analysis, particularly the general emphasis on style and trivia over substance. We then address the cognitive filters that all viewers—including students—bring to these events. Next, we introduce several ideas for disarming these filters. Finally, we conclude by addressing the potential of debates to help political science professors create better prepared voters

Genome-wide screening reveals the genetic basis of mammalian embryonic eye development.

BACKGROUND: Microphthalmia, anophthalmia, and coloboma (MAC) spectrum disease encompasses a group of eye malformations which play a role in childhood visual impairment. Although the predominant cause of eye malformations is known to be heritable in nature, with 80% of cases displaying loss-of-function mutations in the ocular developmental genes OTX2 or SOX2, the genetic abnormalities underlying the remaining cases of MAC are incompletely understood. This study intended to identify the novel genes and pathways required for early eye development. Additionally, pathways involved in eye formation during embryogenesis are also incompletely understood. This study aims to identify the novel genes and pathways required for early eye development through systematic forward screening of the mammalian genome. RESULTS: Query of the International Mouse Phenotyping Consortium (IMPC) database (data release 17.0, August 01, 2022) identified 74 unique knockout lines (genes) with genetically associated eye defects in mouse embryos. The vast majority of eye abnormalities were small or absent eyes, findings most relevant to MAC spectrum disease in humans. A literature search showed that 27 of the 74 lines had previously published knockout mouse models, of which only 15 had ocular defects identified in the original publications. These 12 previously published gene knockouts with no reported ocular abnormalities and the 47 unpublished knockouts with ocular abnormalities identified by the IMPC represent 59 genes not previously associated with early eye development in mice. Of these 59, we identified 19 genes with a reported human eye phenotype. Overall, mining of the IMPC data yielded 40 previously unimplicated genes linked to mammalian eye development. Bioinformatic analysis showed that several of the IMPC genes colocalized to several protein anabolic and pluripotency pathways in early eye development. Of note, our analysis suggests that the serine-glycine pathway producing glycine, a mitochondrial one-carbon donator to folate one-carbon metabolism (FOCM), is essential for eye formation. CONCLUSIONS: Using genome-wide phenotype screening of single-gene knockout mouse lines, STRING analysis, and bioinformatic methods, this study identified genes heretofore unassociated with MAC phenotypes providing models to research novel molecular and cellular mechanisms involved in eye development. These findings have the potential to hasten the diagnosis and treatment of this congenital blinding disease

Erwartungsbildung über den Wahlausgang und ihr Einfluss auf die Wahlentscheidung

Erwartungen über den Wahlausgang haben einen festen Platz sowohl in Rational-Choice-Theorien des Wählerverhaltens als auch in stärker sozialpsychologisch orientierten Ansätzen. Die Bildung von Erwartungen und ihr Einfluss auf die Wahlentscheidung ist dabei jedoch ein noch relativ unerforschtes Gebiet. In diesem Beitrag werden anhand von Wahlstudien für Belgien, Österreich und Deutschland verschiedene Fragen der Erwartungsbildung und ihrer Auswirkungen untersucht. Zunächst wird die Qualität der Gesamterwartungen analysiert und verschiedene Faktoren identifiziert, die einen systematischen Einfluss auf die Erwartungsbildung haben. Im zweiten Schritt wenden wir uns den Einzelerwartungen über verschiedene Parteien und Koalitionen zu und finden eine moderate Verzerrung zugunsten der präferierten Parteien und Koalitionen. Dabei kann gezeigt werden, dass der Effekt des Wunschdenkens mit dem politischen Wissen und dem Bildungsgrad abnimmt. Schließlich werden in einem letzten Schritt zwei unterschiedliche Logiken für die Auswirkungen von Erwartungen getestet, das rationale Kalkül des koalitionsstrategischen Wählens zur Vermeidung der Stimmenvergeudung sowie der sozialpsychologisch begründete Bandwagon-Effekt. Das Ausmaß an politischem Wissen scheint dabei eine zentrale vermittelnde Variable zwischen den beiden Logiken zu sein

The transport mechanism of the mitochondrial ADP/ATP carrier

The mitochondrial ADP/ATP carrier imports ADP from the cytosol and exports ATP from the mitochondrial matrix, which are key transport steps for oxidative phosphorylation in eukaryotic organisms. The transport protein belongs to the mitochondrial carrier family, a large transporter family in the inner membrane of mitochondria. It is one of the best studied members of the family and serves as a paradigm for the molecular mechanism of mitochondrial carriers. Structurally, the carrier consists of three homologous domains, each composed of two transmembrane α-helices linked with a loop and short α-helix on the matrix side. The transporter cycles between a cytoplasmic and matrix state in which a central substrate binding site is alternately accessible to these compartments for binding of ADP or ATP. On both the cytoplasmic and matrix side of the carrier are networks consisting of three salt bridges each. In the cytoplasmic state, the matrix salt bridge network is formed and the cytoplasmic network is disrupted, opening the central substrate binding site to the intermembrane space and cytosol, whereas the converse occurs in the matrix state. In the transport cycle, tighter substrate binding in the intermediate states allows the interconversion of conformations by lowering the energy barrier for disruption and formation of these networks, opening and closing the carrier to either side of the membrane in an alternating way. Conversion between cytoplasmic and matrix states might require the simultaneous rotation of three domains around a central translocation pathway, constituting a unique mechanism among transport proteins. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou

Decoration of T-independent antigen with ligands for CD22 and Siglec-G can suppress immunity and induce B cell tolerance in vivo

Autoreactive B lymphocytes first encountering self-antigens in peripheral tissues are normally regulated by induction of anergy or apoptosis. According to the “two-signal” model, antigen recognition alone should render B cells tolerant unless T cell help or inflammatory signals such as lipopolysaccharide are provided. However, no such signals seem necessary for responses to T-independent type 2 (TI-2) antigens, which are multimeric antigens lacking T cell epitopes and Toll-like receptor ligands. How then do mature B cells avoid making a TI-2–like response to multimeric self-antigens? We present evidence that TI-2 antigens decorated with ligands of inhibitory sialic acid–binding Ig-like lectins (siglecs) are poorly immunogenic and can induce tolerance to subsequent challenge with immunogenic antigen. Two siglecs, CD22 and Siglec-G, contributed to tolerance induction, preventing plasma cell differentiation or survival. Although mutations in CD22 and its signaling machinery have been associated with dysregulated B cell development and autoantibody production, previous analyses failed to identify a tolerance defect in antigen-specific mutant B cells. Our results support a role for siglecs in B cell self-/nonself-discrimination, namely suppressing responses to self-associated antigens while permitting rapid “missing self”–responses to unsialylated multimeric antigens. The results suggest use of siglec ligand antigen constructs as an approach for inducing tolerance

Whole genome assessment of the retinal response to diabetes reveals a progressive neurovascular inflammatory response

<p>Abstract</p> <p>Background</p> <p>Despite advances in the understanding of diabetic retinopathy, the nature and time course of molecular changes in the retina with diabetes are incompletely described. This study characterized the functional and molecular phenotype of the retina with increasing durations of diabetes.</p> <p>Results</p> <p>Using the streptozotocin-induced rat model of diabetes, levels of retinal permeability, caspase activity, and gene expression were examined after 1 and 3 months of diabetes. Gene expression changes were identified by whole genome microarray and confirmed by qPCR in the same set of animals as used in the microarray analyses and subsequently validated in independent sets of animals. Increased levels of vascular permeability and caspase-3 activity were observed at 3 months of diabetes, but not 1 month. Significantly more and larger magnitude gene expression changes were observed after 3 months than after 1 month of diabetes. Quantitative PCR validation of selected genes related to inflammation, microvasculature and neuronal function confirmed gene expression changes in multiple independent sets of animals.</p> <p>Conclusion</p> <p>These changes in permeability, apoptosis, and gene expression provide further evidence of progressive retinal malfunction with increasing duration of diabetes. The specific gene expression changes confirmed in multiple sets of animals indicate that pro-inflammatory, anti-vascular barrier, and neurodegenerative changes occur in tandem with functional increases in apoptosis and vascular permeability. These responses are shared with the clinically documented inflammatory response in diabetic retinopathy suggesting that this model may be used to test anti-inflammatory therapeutics.</p

MUSICAL IMAGERY IN THE POETRY OF JUAN RUIZ, GUILLAUME DE MACHAUT, AND CHAUCER: A COMPARATIVE STUDY

The dissertation is an attempt to elucidate and compare the various allegorical functions of musical imagery in the verse of Juan Ruiz, Guillaume de Machaut, and Chaucer. In the past, a consensus of critics and musicologists has approached music in medieval poetry with the assumption that musical allusions merely reflect the contemporary milieu in a verisimilar way. However, critics of Chaucer in recent decades have begun to discuss how music, which evokes both divine and carnal associations in the fourteenth-century imagination, plays an important role in Chaucer\u27s allegorical designs. By studying the meaning of music in three of the most prominent poets of the fourteenth century, two conclusions will be drawn: first, that iconographic conventions regarding music form part of a common, international syntax which poets of the age employ in their allegories; and, second, that these common musical conventions provide one key to the remarkable stylistic unity evident in the poetic art of fourteenth-century Europe. After a brief introduction describing the importance of musical imagery in the works of the three poets in question, Chapter II is an iconographic reading of music\u27s function in Ruiz\u27s Libro de buen amor. In the prose sermon, in the invocation, in the Marian lyrics, in the Arcipreste\u27s role as a troubadour, in Don Amor\u27s Ovidian advice to the lover-persona, in the seduction intrigue, in the canonical hours parody, in the mock-Easter procession, in the serranas, and in various exempla included throughout the LBA, Ruiz ironically conflates music\u27s traditional divine and fleshly associations to further the allegorical sententia of his librete de cantares. Chapter III discusses the symbolic functions of music in three of Machaut\u27s early works: Le jugement dou roy de Behaingne, Le jugement dou roy de Navarre, and the Remede de Fortune. Unlike Ruiz, Machaut prescinds from music\u27s carnal aspect in contemporary thought and instead uses harmony as a figure for divine order. In this way, Machaut underscores the spiritual themes that are central to his ostensibly frivolous poetic treatments of love. The fourth chapter focuses on Chaucerian poems that as yet have not received adequate critical attention regarding their use of musical imagery. In the first part of the chapter, the Book of the Duchess is shown to employ a concept of spiritually therapeutic musica divina in a Machautesque fashion. The main body of the chapter attempts to prove a bit more deeply than has previous criticism into the significance of musical allusions pertaining to the Summoner and Pardoner in the General Prologue, in the Summoner\u27s Tale, and in the Pardoner\u27s Tale. A consistent perversion of sacred music, it is demonstrated, helps to underscore the Summoner\u27s and Pardoner\u27s perversion of their ecclesiastical degree, and furthermore illustrates the symbiotic relationship that exists between these two figures, whose singing of an amorous duet in the General Prologue intimates their collusion as fellow corrupters of divine harmony. The final chapter provides a comparative overview of the various imaginative approaches to music in the poems of Ruiz, Machaut, and Chaucer

A lecture on the averaging process

To interpret interacting particle system style models as social dynamics, suppose each pair {i, j} of individuals in a finite population meet at random times of arbitrary specified rates vij, and update theirstates according to some specified rule. The averaging process has real-valued states and the rule: upon meeting, the values Xi(t-),Xj (t-) arereplaced by 1/2 (Xi(t-) + Xj (t-)), 1/2 (Xi(t-) + Xj (t-)). It is curious this simple process has not been studied very systematically. We provide an expository account of basic facts and open problems