Nonadiabatic extension of the Heisenberg model

The localized states within the Heisenberg model of magnetism should be represented by best localized Wannier functions forming a unitary transformation of the Bloch functions of the narrowest partly filled energy bands in the metals. However, as a consequence of degeneracies between the energy bands near the Fermi level, in any metal these Wannier functions cannot be chosen symmetry-adapted to the complete paramagnetic group M^P. Therefore, it is proposed to use Wannier functions with the reduced symmetry of a magnetic subgroup M of M^P [case (a)] or spin dependent Wannier functions [case (b)]. The original Heisenberg model is reinterpreted in order to understand the pronounced symmetry of these Wannier functions. While the original model assumes that there is exactly one electron at each atom, the extended model postulates that in narrow bands there are as many as possible atoms occupied by exactly one electron. However, this state with the highest possible atomiclike character cannot be described within the adiabatic (or Born-Oppenheimer) approximation because in the (true) nonadiabatic system the electrons move on localized orbitals that are still symmetric on the average of time, but not at any moment. The nonadiabatic states have the same symmetry as the adiabatic states and determine the commutation properties of the nonadiabatic Hamiltonian H^n. The nonadiabatic Heisenberg model is a purely group- theoretical model which interprets the commutation properties of H^n that are explicitly given in this paper for the two important cases (a) and (b). There is evidence that the occurrence of these two types of Wannier functions in the band structure of a metal is connected with the occurrence of magnetism and superconductivity, respectively

Trends in forest taxes in South Missouri

Cover title.Includes bibliographical references (page 26)

Sawmill efficiency in the eastern Ozark region

This bulletin reports on School of Forestry research project 450, Sawmill Efficiency--P. [2].Includes bibliographical references (page 31)

Towards Linked Data for Oceanographic Science: The R2R Eventlogger Project, Controlled Vocabularies, and Ontologies at The MBLWHOI Library

Objective: Research vessels coordinated by the United States University-National Oceanographic Laboratory System (US-UNOLS) collect data which are considered important oceanographic science research products. The NSF-funded Rolling Deck to Repository (R2R) project aims to improve access to these data and diminish barriers to their use. One aspect of the R2R project has been to develop a shipboard scientific event logging system, Eventlogger, which incorporates best practice guidelines, controlled vocabularies, a cruise metadata schema, and a scientific event log. Eventlogger facilitates the eventual ingestion of datasets into oceanographic data repositories for subsequent integration and synthesis by investigators. The careful use of controlled vocabularies and ontologies is an important feature of this system, as the use of internationally-informed, consensus-driven controlled vocabularies will make data sets more interoperable, discoverable and reusable. Methods: The R2R Eventlogger project is led by Woods Hole Oceanographic Institution (WHOI), and the management of the controlled vocabularies is led by the Data Librarian in the Marine Biological Laboratory/Woods Hole Oceanographic Institution (MBLWHOI) Library. The first target vocabulary has been one for oceanographic instruments. Management of this vocabulary has thus far consisted of reconciling project vocabulary terms with the more widely used community vocabularies served by the NERC Vocabulary Server v2.0 (NVS2.0): terms included in the SeaDataNet Device Catalogue (L22) and the SeaDataNet Device Category vocabularies (L05). Rather than adopt existing community terms, it is more often the case that local terms are mapped by the Data Managers in the NSF-funded Biological and Chemical Oceanographic Data Management Office (BCO-DMO) to community terms, which preserves any important information and meaning investigators impart through the process of assigning these local terms, and has less impact on researchers. New terms, those that cannot be mapped to the existing community vocabularies (often custom, or modified instruments), are submitted for review to the SeaVOX governance process for addition to the community vocabularies. These vocabularies and their mappings are an important part of the aforementioned Eventlogger system. Before a research cruise, investigators configure the instruments they intend to use for their science activities. The instruments available for selection are provided by the MBLWHOI Data Librarian, who curates UNOLS ship-specific lists of standard shipboard instruments using terms for instruments from the R2R Eventlogger Project Vocabulary. Nonstandard shipboard instruments a researcher or investigator wishes to use can also be added, and these instrument terms will eventually be inducted into the R2R Eventlogger Project Vocabulary. Results: Eventlogger is currently being tested across the UNOLS fleet. A large submission of suggested instrument terms to the SeaDataNet community listserv is currently in progress. New tools for facilitating the management, mapping, and use of these controlled vocabularies are being developed, and new projects with eager partners are envisioned. Ideas for future controlled vocabularies for the ocean science community include: Cruise IDs, Persons, and Ships. Conclusions: The promotion and use of controlled vocabularies and ontologies will pave the way for linked data in oceanographic science. By mapping local terms to authoritative and community-accepted terms, links are created whereby related data sets can be better discovered, and utilized. Librarians have an established history of working with controlled vocabularies and metadata. Libraries, have and will continue to, serve as centers for information discovery as well as a natural home for the management of standards

Ocean data publication cookbook

This cookbook is an outcome of the 5th session of the SCOR/IODE/MBLWHOI Library Workshop on Data Publication and is posted here by permission of UNESCO.Executive summary: This “Cookbook” has been written for data managers and librarians who are interested in assigning a permanent identifier to a dataset for the purposes of publishing that dataset online and for the citation of that dataset within the scientific literature. A formal publishing process adds value to the dataset for the data originators as well as for future users of the data. Value may be added by providing an indication of the scientific quality and importance of the dataset (as measured through a process of peer review), and by ensuring that the dataset is complete, frozen and has enough supporting metadata and other information to allow it to be used by others. Publishing a dataset also implies a commitment to persistence of the data and allows data producers to obtain academic credit for their work in creating the datasets. One form of persistent identifier is the Digital Object Identifier (DOI). A DOI is a character string (a "digital identifier") used to provide a unique identity of an object such as an electronic document. Metadata about the object is stored in association with the DOI name and this metadata may include a location where the object can be found. The DOI for a document is permanent, whereas its location and other metadata may change. Referring to an online document by its DOI provides more stable linking than simply referring to it by its URL, because if its URL changes, the publisher need only update the metadata for the DOI to link to the new URL. A DOI may be obtained for a variety of objects, including documents, data files and images. The assignment of DOIs to peer-reviewed journal articles has become commonplace. This cookbook provides a step-by-step guide to the data publication process and showcases some best practices for data publication

Emerging Role of Librarians in Data Publication

Purpose: This poster demonstrates the procedures and tools developed to deposit datasets in an Institutional Repository (IR) and assign Digital Object Identifiers (DOIs). Setting/Participants/Resources: This research is being conducted by a team of librarians, data managers and scientists that are collaborating with representatives from the Scientific Committee on Oceanic Research (SCOR) and the International Oceanographic Data and Information Exchange (IODE) of the Intergovernmental Oceanographic Commission (IOC). The goal is to identify best practices for tracking data provenance and clearly attributing credit to data collectors/providers. Description: Current literature on the topic of data publication suggests that success is best achieved when there is a partnership between scientists, data managers, and librarians. The Marine Biological Laboratory/Woods Hole Oceanographic Institution (MBLWHOI) Library and the Biological and Chemical Oceanography Data Management Office (BCO-DMO) have developed tools and processes to automate the ingestion of metadata from BCO-DMO for deposit with datasets into the Institutional Repository (IR) Woods Hole Open Access Server (WHOAS). The system also incorporates functionality for BCO-DMO to request a Digital Object Identifier (DOI) from the Library. This partnership allows the Library to work with a trusted data repository to ensure high quality data while the data repository utilizes library services and is assured of a permanent archive of the copy of the data extracted from the repository database. While the WHOI Data Library and Archives has long been recognized as a valuable local resource, this project is an example of an important new role for the facility in providing the essential service of scientific data publication. The diversity and volume of modern research data sets precludes their publication in the peer reviewed journals that are the currency of scientific research. The process of developing the initial publication system required active engagement of the research community and the working system provides a valuable resource that supports networked science by improving access to data, enabling accurate reuse of data and facilitating proper citation of data resources. Results/Outcome: The assignment of persistent identifiers enables accurate data citation. The Library can assign a DOI to appropriate datasets deposited in WHOAS. A primary activity is working with authors to deposit datasets associated with published articles. The DOI would ideally be assigned before submission and be included in the published paper so readers can link directly to the dataset, but DOIs are also being assigned to datasets related to articles after publication. WHOAS metadata records link the article to the datasets and the datasets to the article. The assignment of DOIs has enabled another important collaboration with Elsevier, publisher of educational and professional science journals. Elsevier can now link from articles in the Science Direct database to the datasets available from WHOAS that are related to that article. The data associated with the article are freely available from WHOAS and accompanied by a Dublin Core metadata record. In addition, the Library has worked with researchers to deposit datasets in WHOAS that are not appropriate for national, international, or domain specific data repositories. These datasets currently include audio, text and image files. Related Publications: http://www.iode.org/index.php?option=com_oe&task=viewDocumentRecord&docID=2457 http://www.iode.org/index.php?option=com_oe&task=viewDocumentRecord&docID=5437 http://www.iode.org/index.php?option=com_oe&task=viewDocumentRecord&docID=8098 http://tw.rpi.edu/proj/portal.wiki/images/3/3b/JewettSummary.pd

An Ontology Pattern for Oceanographic Cruises: Towards an Oceanographer\u27s Dream of Integrated Knowledge Discovery

EarthCube is a major effort of the National Science Foundation to establish a next-generation knowledge architecture for the broader geosciences. Data storage, retrieval, access, and reuse are central parts of this new effort. Currently, EarthCube is organized around several building blocks and research coordination networks. OceanLink is a semantics enabled building block that aims at improving data retrieval and reuse via ontologies, Semantic Web technologies, and Linked Data for the ocean sciences. Cruises, in the sense of research expeditions, are central events for ocean scientists. Consequently, information about these cruises and the involved vessels has to be shared and made retrievable. For example, the ability to find cruises in the vicinity of physiographic features of interest, e.g., a hydrothermal vent field or a fracture zone, is of primary interest for oceanographers. In this paper, we use a design pattern-centric strategy to engineer ontologies for OceanLink. We provide a formal axiomatization of the introduced patterns and ontologies using the Web Ontology Language, explain design choices, discuss the re-usability of our models, and provide lessons learned for the future geo-ontologies

Reorganization of the chick basilar papilla after acoustic trauma

The auditory epithelium in birds and mammals consists of a postmitotic population of hair cells and supporting cells. Unlike mammals, birds can regenerate their auditory epithelia after trauma. Recent evidence indicates that supporting cells undergo mitosis after acoustic trauma, suggesting that supporting cells may transdifferentiate into hair cells. The goals of this study were to (1) characterize the responses of hair cells and supporting cells to acoustic trauma, and (2) determine whether hair cell loss is a prerequisite for generation of new hair cells. Chicks were exposed to an octave-band noise and their inner ears assayed with fluorescence or scanning electron microscopy. In one area of the basilar papilla, defined as the center of the lesion, extensive hair cell degeneration occurred. Expanded supporting cells obliterated degenerating hair cells and invaded spaces normally occupied by hair cells. Aggregates of DNA were found within the basilar papilla, suggesting that hair cell death and disintegration may occur within the epithelium. The epithelial sheet appeared structurally confluent at all times examined. Supporting cells exhibited altered apical contour in distal regions of the basilar papilla, where hair cell damage was mild or inconspicuous. Four days after noise exposure, newly generated hair cells were found in the center of the lesion and in the distal areas, where no hair cell loss could be detected. The results suggest that supporting cells may play an important role in maintenance and repair of the traumatized basilar papilla and raise the possibility that production of new hair cells is not dependent on hair cell loss in the immediate vicinity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50055/1/903300408_ftp.pd

The Parallel Complexity of Growth Models

This paper investigates the parallel complexity of several non-equilibrium growth models. Invasion percolation, Eden growth, ballistic deposition and solid-on-solid growth are all seemingly highly sequential processes that yield self-similar or self-affine random clusters. Nonetheless, we present fast parallel randomized algorithms for generating these clusters. The running times of the algorithms scale as $O(\log^2 N)$, where $N$ is the system size, and the number of processors required scale as a polynomial in $N$. The algorithms are based on fast parallel procedures for finding minimum weight paths; they illuminate the close connection between growth models and self-avoiding paths in random environments. In addition to their potential practical value, our algorithms serve to classify these growth models as less complex than other growth models, such as diffusion-limited aggregation, for which fast parallel algorithms probably do not exist.Comment: 20 pages, latex, submitted to J. Stat. Phys., UNH-TR94-0