Computing Hilbert Class Polynomials

We present and analyze two algorithms for computing the Hilbert class polynomial $H_D$ . The first is a p-adic lifting algorithm for inert primes p in the order of discriminant D < 0. The second is an improved Chinese remainder algorithm which uses the class group action on CM-curves over finite fields. Our run time analysis gives tighter bounds for the complexity of all known algorithms for computing $H_D$, and we show that all methods have comparable run times

The PlaNet Consortium: A Network of European Plant Databases Connecting Plant Genome Data in an Integrated Biological Knowledge Resource

The completion of the Arabidopsis genome and the large collections of other plant sequences generated in recent years have sparked extensive functional genomics efforts. However, the utilization of this data is inefficient, as data sources are distributed and heterogeneous and efforts at data integration are lagging behind. PlaNet aims to overcome the limitations of individual efforts as well as the limitations of heterogeneous, independent data collections. PlaNet is a distributed effort among European bioinformatics groups and plant molecular biologists to establish a comprehensive integrated database in a collaborative network. Objectives are the implementation of infrastructure and data sources to capture plant genomic information into a comprehensive, integrated platform. This will facilitate the systematic exploration of Arabidopsis and other plants. New methods for data exchange, database integration and access are being developed to create a highly integrated, federated data resource for research. The connection between the individual resources is realized with BioMOBY. BioMOBY provides an architecture for the discovery and distribution of biological data through web services. While knowledge is centralized, data is maintained at its primary source without a need for warehousing. To standardize nomenclature and data representation, ontologies and generic data models are defined in interaction with the relevant communities.Minimal data models should make it simple to allow broad integration, while inheritance allows detail and depth to be added to more complex data objects without losing integration. To allow expert annotation and keep databases curated, local and remote annotation interfaces are provided. Easy and direct access to all data is key to the project

Conference Review The PlaNet consortium: a network of European plant databases connecting plant genome data in an integrated biological knowledge resource

Abstract The completion of the Arabidopsis genome and the large collections of other plant sequences generated in recent years have sparked extensive functional genomics efforts. However, the utilization of this data is inefficient, as data sources are distributed and heterogeneous and efforts at data integration are lagging behind. PlaNet aims to overcome the limitations of individual efforts as well as the limitations of heterogeneous, independent data collections. PlaNet is a distributed effort among European bioinformatics groups and plant molecular biologists to establish a comprehensive integrated database in a collaborative network. Objectives are the implementation of infrastructure and data sources to capture plant genomic information into a comprehensive, integrated platform. This will facilitate the systematic exploration of Arabidopsis and other plants. New methods for data exchange, database integration and access are being developed to create a highly integrated, federated data resource for research. The connection between the individual resources is realized with BioMOBY. BioMOBY provides an architecture for the discovery and distribution of biological data through web services. While knowledge is centralized, data is maintained at its primary source without a need for warehousing. To standardize nomenclature and data representation, ontologies and generic data models are defined in interaction with the relevant communities. Minimal data models should make it simple to allow broad integration, while inheritance allows detail and depth to be added to more complex data objects without losing integration. To allow expert annotation and keep databases curated, local and remote annotation interfaces are provided. Easy and direct access to all data is key to the project

Some genus 3 curves with many points

Using an explicit family of plane quartic curves, we prove the existence of a genus 3 curve over any finite field of characteristic 3 whose number of rational points stays within a fixed distance from the Hasse-Weil-Serre upper bound. We also provide an intrinsic characterization of so-called Legendre elliptic curves

Primitive normal bases for finite fields

Wetensch. publicatieFaculteit der Wiskunde en Natuurwetenschappe

Выявление гидравлической взаимосвязи водных объектов района Томского водозабора на основе гидрогеохимических данных (Томский район)

Объектом изучения является месторождение подземных вод Томской области. Химический состав подземных вод формируется в результате инфильтрации атмосферных осадков, из элементов, выщелачиваемых из растений, расти-тельных остатков и почв, продуктов выветривания вмещающих пород, а также из ионов, образующихся при взаимодей-ствии воды с атмогенно-биогенно-литогенной и газовой составляющей. В работе рассматривается взаимодействие палеоге-нового водоносного комплекса с поверхностными водами (р. Томь), и мелового водоносного комплекса.The object of research is aquifer water of the Tomsk region. Chemical composition of groundwater formed from the infiltration of atmospheric pre-cipitation of the elements leached from plants, plant residues and soil products of weathering of host rocks, as well as from ions, about-razuysya in the inter-action of water with atrogenna-biogenic and lithogenic gas component. This paper examines the interaction of the Paleogene aquifer with surface water (R. Tom), and the Cretaceous aquifer

Cubic Curves, Finite Geometry and Cryptography

Some geometry on non-singular cubic curves, mainly over finite fields, is surveyed. Such a curve has 9,3,1 or 0 points of inflexion, and cubic curves are classified accordingly. The group structure and the possible numbers of rational points are also surveyed. A possible strengthening of the security of elliptic curve cryptography is proposed using a `shared secret' related to the group law. Cubic curves are also used in a new way to construct sets of points having various combinatorial and geometric properties that are of particular interest in finite Desarguesian planes.Comment: This is a version of our article to appear in Acta Applicandae Mathematicae. In this version, we have corrected a sentence in the third paragraph. The final publication is available at springerlink.com at http://www.springerlink.com/content/xh85647871215644

Photoelectron Spectroscopy of 9-Substituted Anthracenes

The Hel photoelectron (PE) spectra of anthracene and ten of its 9-substituted derivatives with methyl, t ert-butyl, fluoro; chloro, bromo, methoxy, aldehyde, cyano, nitro and phenyl groups as substituents have been recorded. Systems arising from Jt-ionizations are assigned. The assignment is supported by molecular orbital calculations. The effect of the substituent on the lowest ionization energy is well described by Hammett substituent constants based on the benzene system