Local structure order parameters and site fingerprints for quantification of coordination environment and crystal structure similarity

Structure characterization and classification is frequently based on local environment information of all or selected atomic sites in the crystal structure. Therefore, reliable and robust procedures to find coordinated neighbors and to evaluate the resulting coordination pattern (e.g., tetrahedral, square planar) are critically important for both traditional and machine learning approaches that aim to exploit site or structure information for predicting materials properties. Here, we introduce new local structure order parameters (LoStOPs) that are specifically designed to rapidly detect highly symmetric local coordination environments (e.g., Platonic solids such as a tetrahedron or an octahedron) as well as less symmetric ones (e.g., Johnson solids such as a square pyramid). Furthermore, we introduce a Monte Carlo optimization approach to ensure that the different LoStOPs are comparable with each other. We then apply the new local environment descriptors to define site and structure fingerprints and to measure similarity between 61 known coordination environments and 40 commonly studied crystal structures, respectively. After extensive testing and optimization, we determine the most accurate structure similarity assessment procedure to compute all 2.45 billion structure similarities between each pair of the ≈70000 materials that are currently present in the Materials Project database

The Carcinoembryonic Antigen Gene Family

The molecular cloning of carcinoembryonic antigen (CEA) and several cross-reacting antigens reveals a basic domain structure for the whole family, which shows structural similarities to the immunoglobulin superfamily. The CEA family consists of approximately 10 genes which are localized in two clusters on chromosome 19. So far, mRNA species for five of these genes have been identified which show tissue variability in their transcriptional activity. Expression of some of these genes in heterologous systems has been achieved, allowing the localization of some epitopes. The characterization of a CEA gene family in the rat and a comparison with its human counterpart has been utilized in the development of an evolutionary model

WTO Dispute Settlement at Ten: Evolution, Experiences, and Evaluation

ENGLISH ABSTRACT: On 1 January 1995, the Understanding on Rules and Procedures Governing the Settlement of Disputes (DSU) entered into force. During its first ten years, the DSU has since been applied to 324 complaints – more cases than dispute settlement under the GATT 1947 had dealt with in nearly five decades. The system is perceived, both by practitioners and in academic literature, to work generally well. However, it has also revealed some flaws. Negotiations to review and reform the DSU have been taking place since 1997 (“DSU review”), however, without yielding any result so far. In the meantime, WTO Members and adjudicating bodies managed to develop the system further through evolving practice. While this approach may remedy some practical shortcomings of the DSU text, the more profound imbalance between relatively efficient judicial decisionmaking in the WTO (as incorporated in the DSU) and nearly blocked political decisionmaking evolves into a serious challenge to the sustainability of the system. This article provides an overview of the first ten years of DSU practice, the on- going DSU review negotiations, and the challenges to the dispute settlement system. GERMAN ABSTRACT: Am 1. Januar 1995 trat das Übereinkommen über Regeln und Verfahren für die Streitschlichtung (Dispute Settlement Understanding; DSU) als Teil des WTO-Abkommens in Kraft. In den ersten zehn Jahren seines Bestehens fand das DSU auf 324 Klagebegehren Anwendung – mehr Fälle, als unter den Streitschlichtungsregeln des GATT 1947 in dessen nahezu fünfzigjähriger Geschichte behandelt wurden. Die Funktionsweise des Systems wird sowohl in der handelspolitischen Praxis als auch in der wissenschaftlichen Literatur als gut eingestuft. Gleichwohl hat der Mechanismus in seiner Anwendung auch einige Schwächen offenbart. Diese sollen auf dem Verhandlungswege („DSU Review“) behoben werden, doch blieben die seit Ende 1997 laufenden Gespräche bislang erfolglos. Zugleich ist es den Mitgliedstaaten und den Spruchorganen aber stellenweise gelungen, das System im Rahmen der praktischen Anwendung fortzuentwickeln. Während auf diesem Weg einige praktische Probleme des Verfahrenstextes behoben werden konnten, dürfte das beträchtliche Ungleichgewicht in der WTO zwischen einem vergleichsweise effizienten juristischen Entscheidungsmechanismus (in Form des DSU) und den häufig blockierten politischen Entscheidungsmechanismen fortbestehen. Dieses Ungleichgewicht bedroht die Systemnachhaltigkeit. Der vorliegende Artikel gibt einen Überblick über die ersten zehn Jahre DSU-Praxis, die laufenden DSU-Review-Verhandlungen sowie einen Ausblick auf zukünftige Herausforderungen.WTO, Dispute Settlement, DSU Review Negotiations

Comment on "Dephasing Times in Quantum Dots due to Elastic LO Phonon-Carrier Collisions"

This paper is a Comment on Phys. Rev. Lett. 85, 1516 (2000) by A.V. Uskov, A.-P. Jauho, B. Tromborg, J. Mork, and R. Lang.Comment: 1 page, 1 figure. Phys. Rev. Lett., accepte

The gravitational wave spectrum of non-axisymmetric, freely precessing neutron stars

Evidence for free precession has been observed in the radio signature of several pulsars. Freely precessing pulsars radiate gravitationally at frequencies near the rotation rate and twice the rotation rate, which for rotation frequencies greater than $\sim 10$ Hz is in the LIGO band. In older work, the gravitational wave spectrum of a precessing neutron star has been evaluated to first order in a small precession angle. Here we calculate the contributions to second order in the wobble angle, and we find that a new spectral line emerges. We show that for reasonable wobble angles, the second-order line may well be observable with the proposed advanced LIGO detector for precessing neutron stars as far away as the galactic center. Observation of the full second-order spectrum permits a direct measurement of the star's wobble angle, oblateness, and deviation from axisymmetry, with the potential to significantly increase our understanding of neutron star structure.Comment: 22 pages, 1 figure. Minor changes in the text, typos correcte

The Challenge of Reforming the WTO Dispute Settlement Understanding

The May 2003 deadline for the completion of the negotiations on improvements and clarifications of the Dispute Settlement Understanding (DSU) under the Doha Mandate has not been met. However, Members agreed in July 2003 to extend the deadline for the review until the end of May 2004. This article briefly summarises the past six years of negotiations on the DSU review, the most contentious issues and the systemic difficulties of the negotiations. We conclude with prospects for the forthcoming negotiations until 2004.WTO Dispute Settlement Understanding DSU Review

Intra- and Interspecies Analyses of the Carcinoembryonic Antigen (CEA) Gene Family Reveal Independent Evolution in Primates and Rodents

Various rodent and primate DNAs exhibit a stronger intra- than interspecies cross-hybridization with probes derived from the N-terminal domain exons of human and rat carcinoembryonic antigen (CEA)-like genes. Southern analyses also reveal that the human and rat CEA gene families are of similar complexity. We counted at least 10 different genes per human haploid genome. In the rat, approximately seven to nine different N-terminal domain exons that presumably represent different genes appear to be present. We were able to assign the corresponding genomic restriction endonuclease fragments to already isolated CEA gene family members of both human and rat. Highly similar subgroups, as found within the human CEA gene family, seem to be absent from the rat genome. Hybridization with an intron probe from the human nonspecific cross-reacting antigen (NCA) gene and analysis of DNA sequence data indicate the conservation of noncoding regions among CEA-like genes within primates, implicating that whole gene units may have been duplicated. With the help of a computer program and by calculating the rate of synonymous substitutions, evolutionary trees have been derived. From this, we propose that an independent parallel evolution, leading to different CEA gene families, must have taken place in, at least, the primate and rodent orders

Ubiquitous Nuclear Factors Bind Specifically to a 5′-Region Conserved in Carcinoembryonic Antigen-Related Genes

We recently cloned members of the murine carcinoembryonic antigen (CEA) gene family, some of which are differentially expressed during placental development. By intra- and interspecies sequence comparisons, we identified an element in the putative promoter and/or 5′-nontranslated region which is conserved within all human and rodent CEA-related genes analyzed so far. Using gel retardation analysis and DNasel hypersensitive site mapping, we now show that ubiquitously expressed nuclear factors specifically bind to the conserved region derived from the mouse gene Cea-2 in vitro and probably also in vivo. Another DNasel hypersensitive site lies within or close to a simple sequence motif [(GGA)n] located in the first intron of Cea-2. Such sequences have been reported to play a role in the regulation of certain genes. Therefore, this analysis has identified putative regulatory regions for Cea-2 and possibly CEA-related genes in general