INITIAL CHARACTERIZATION OF MAJOR HISTOCOMPATIBILITY COMPLEX (MHC) CLASS IIB EXON 2 IN AN ENDANGERED RATTLESNAKE, THE EASTERN MASSASAUGA (SISTRURUS CATENATUS)

Genes of the major histocompatibility complex (MHC) play an important role in the vertebrate immune system and exhibit remarkably high levels of polymorphism, maintained by strong balancing selection. While the conservation implications of MHC variation have been explored in a variety of vertebrates, non-avian reptiles (most notably snakes) have received less attention. To address this gap and take the first steps toward more extensive population-level analyses, we cloned and sequenced MHC IIB exon 2 in an endangered rattlesnake, the Eastern Massasauga (Sistrurus catenatus). Based on three individuals, we found evidence of at least four putatively functional loci. These sequences exhibited relatively high levels of variation and significantly higher rates of nonsynonymous to synonymous substitutions, especially within the antigen-binding sites, indicating strong positive selection. Phylogenetic analysis revealed a pattern of trans-species polymorphism, also suggesting positive selection. These results contribute to our understanding of MHC variation in non-avian reptiles and form a basis for more studies of MHC variation in snakes of conservation concern

CURLY LEAF is required for the auxin-dependent regulation of 3-dimensional growth specification in Physcomitrium patens

The no gametophores 4 (nog4-R) mutant cannot make the transition from 2-dimensional (2D) to 3-dimensional (3D) growth in Physcomitrium patens and forms side branch initials that are largely fated to become sporophyte-like structures. We describe the three different developmental trajectories adopted by the nog4-R mutant, all of which result in indeterminate growth and defects in cell division plane orientation. A candidate gene approach confirmed that the causative mutation resided in the CURLY LEAF gene, and we highlight a previously uncharacterized role for CURLY LEAF in maintaining auxin homeostasis in P. patens

Is the five-flow conjecture almost false?

The number of nowhere zero Z_Q flows on a graph G can be shown to be a polynomial in Q, defining the flow polynomial \Phi_G(Q). According to Tutte's five-flow conjecture, \Phi_G(5) > 0 for any bridgeless G.A conjecture by Welsh that \Phi_G(Q) has no real roots for Q \in (4,\infty) was recently disproved by Haggard, Pearce and Royle. These authors conjectured the absence of roots for Q \in [5,\infty). We study the real roots of \Phi_G(Q) for a family of non-planar cubic graphs known as generalised Petersen graphs G(m,k). We show that the modified conjecture on real flow roots is also false, by exhibiting infinitely many real flow roots Q>5 within the class G(nk,k). In particular, we compute explicitly the flow polynomial of G(119,7), showing that it has real roots at Q\approx 5.0000197675 and Q\approx 5.1653424423. We moreover prove that the graph families G(6n,6) and G(7n,7) possess real flow roots that accumulate at Q=5 as n\to\infty (in the latter case from above and below); and that Q_c(7)\approx 5.2352605291 is an accumulation point of real zeros of the flow polynomials for G(7n,7) as n\to\infty.Comment: 44 pages (LaTeX2e). Includes tex file, three sty files, and a mathematica script polyG119_7.m. Many improvements from version 3, in particular Sections 3 and 4 have been mostly re-writen, and Sections 7 and 8 have been eliminated. (This material can now be found in arXiv:1303.5210.) Final version published in J. Combin. Theory

Eine Arbeitslosenversicherung für den Euroraum als automatischer Stabilisator: Grenzen und Möglichkeiten. Endbericht: Gutachten im Auftrag des Bundesministeriums für Arbeit, Soziales und Konsumentenschutz der Republik Österreich

Die vorliegende Studie analysiert die makroökonomischen Stabilisierungs- und mikroökonomischen Verteilungswirkungen der Einführung einer Europäischen Arbeitslosenversicherung. Auf Grundlage dynamischer makroökonomischer Simulationen wird gezeigt, dass ein solches Transfersystem innerhalb des Euroraums - je nach Ausgestaltung - zu einer merklichen Stabilisierung der wirtschaftlichen Entwicklung geführt hätte. Dies gilt selbst für eine gemessen am Transferumfang relativ kleine Europäische Arbeitslosenversicherung mit einer maximalen Bezugszeit von sechs Monaten und einer Nettoersatzquote von 30 Prozent; mit größerem Leistungsumfang steigt die Stabilisierungswirkung, aber im Gegenzug auch die möglicherweise unerwünschten Wirkungen auf Arbeitsanreize und das Ausmaß der Umverteilung zwischen den Mitgliedsländern. Die Verteilungswirkungen dürften insgesamt aus politischer Sicht unproblematisch sein; tendenziell finden sich leicht progressive bis neutrale Effekte auf die Einkommensverteilung, Haushalte mit niedrigeren Einkommen profitieren also überproportional von der Einführung einer Europäischen Arbeitslosenversicherung. [...]The present study analyzes the stabilization and distributional effects of the establishment of a European unemployment insurance. Using dynamic macroeconomic simulations it is shown that, depending on the design, such a transfer system within the Eurozone would lead to a sizeable stabilization of output and employment. This is also true for an insurance scheme of relatively small size (in terms of the respective transfers to the unemployed), with a maximum period of entitlement to unemployment benefits of six months and a net replacement rate of 30 percent. A larger scheme would have greater stabilizing effects but would be coupled with potentially undesirable consequences for work incentives and fiscal redistribution between member states. From a policy perspective, the distributional effects within a country can be expected to be limited, with slightly progressive or neutral effects on income inequality. As a result, households with lower incomes are expected to disproportionately benefit from the introduction of a European unemployment insurance. [...

Mean Field Theory of the Localization Transition

A mean field theory of the localization transition for bosonic systems is developed. Localization is shown to be sensitive to the distribution of the random site energies. It occurs in the presence of a triangular distribution, but not a uniform one. The inverse participation ratio, the single site Green's function, the superfluid order parameter and the corresponding susceptibility are calculated, and the appropriate exponents determined. All of these quantities indicate the presence of a new phase, which can be identified as the {\it Bose-glass}.Comment: 4 pages, Revtex, 2 figures appende

A national data system on elementary and secondary education

In the U.S., major changes in education information needs have resulted from widespread dissatisfaction with learning outcomes and dramatic changes in decision processes and policies. The inadequate quality of existing information has sharpened demands for improvement. This report, prepared for the U.S. Education Department, recommends a new national information system, with (a) sample micro-records for pupils, educational personnel, districts and schools --public and non-public, (b) coverage of family and community, pupils' educative difficulties, resources, goals, schooling process, and outcomes, and (c) accurate characterization of each state. The system should include state participation options, comprehensive data access and dissemination, and five-year phasing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26962/1/0000529.pd