A pragmatic approach to hierarchical categorization of research expertise in the presence of scarce information

International Journal on Digital Libraries - Throughout the history of science, different knowledge areas have collaborated to overcome major research challenges. The task of associating a...     

Rhizomucor pusillus mucormycosis combined with chlamydiosis in an African grey parrot (Psittacus erithacus erithacus)

This paper describes a case of mucormycosis combined with chlamydiosis in an African grey parrot (Psittacus erithacus erithacus). The clinical signs included diarrhoea, an unsteady gait and a twisted neck. Smears of the spleen, liver and contents of the cloaca stained strongly positive for Chlamydia species. Histologically, hyphae typical of Zygomycetes were observed invading through the walls of blood vessels of the spleen. Rhizomucor pusillus was isolated as a pure culture from the intestines, lungs and liver.     

A Web services-based framework for building componentized digital libraries

We present a new Web services-based framework for building componentized digital libraries (DLs). We particularly demonstrate how traditional RDBMS technology can be easily deployed to support several common digital library services. Configuration and customization of the framework to build specialized systems is supported by a wizard-like tool which is based on a generic metamodel for DLs. Such a tool implements a workflow process that segments the DL design tasks into well-defined steps and drives the designer along these steps. Both the framework and the configuration tool are evaluated in terms of several performance and usability criteria. Our experimental evaluation demonstrates the feasibility and superior performance of our framework, as well as the effectiveness of the wizard tool for setting up DLs.     

A Genre-Aware Approach to Focused Crawling

Focused crawlers have as their main goal to crawl Web pages that are relevant to a specific topic or user interest, playing an important role for a great variety of applications. In general, they work by trying to find and crawl all kinds of pages deemed as related to an implicitly declared topic. However, users are often not simply interested in any document about a topic, but instead they may want only documents of a given type or genre on that topic to be retrieved. In this article, we describe an approach to focused crawling that exploits not only content-related information but also genre information present in Web pages to guide the crawling process. This approach has been designed to address situations in which the specific topic of interest can be expressed by specifying two sets of terms, the first describing genre aspects of the desired pages and the second related to the subject or content of these pages, thus requiring no training or any kind of preprocessing. The effectiveness, efficiency and scalability of the proposed approach are demonstrated by a set of experiments involving the crawling of pages related to syllabi of computer science courses, job offers in the computer science field and sale offers of computer equipments. These experiments show that focused crawlers constructed according to our genre-aware approach achieve levels of F1 superior to 88%, requiring the analysis of no more than 65% of the visited pages in order to find 90% of the relevant pages. In addition, we experimentally analyze the impact of term selection on our approach and evaluate a proposed strategy for semi-automatic generation of such terms. This analysis shows that a small set of terms selected by an expert or a set of terms specified by a typical user familiar with the topic is usually enough to produce good results and that such a semi-automatic strategy is very effective in supporting the task of selecting the sets of terms required to guide a crawling process.     

An evolutionary approach to complex schema matching

The schema matching problem can be defined as the task of finding semantic relationships between schema elements existing in different data repositories. Despite the existence of elaborated graphic tools for helping to find such matches, this task is usually manually done. In this paper, we propose a novel evolutionary approach to addressing the problem of automatically finding complex matches between schemas of semantically related data repositories. To the best of our knowledge, this is the first approach that is capable of discovering complex schema matches using only the data instances. Since we only exploit the data stored in the repositories for this task, we rely on matching strategies that are based on record deduplication (aka, entity-oriented strategy) and information retrieval (aka, value-oriented strategy) techniques to find complex schema matches during the evolutionary process. To demonstrate the effectiveness of our approach, we conducted an experimental evaluation using real-world and synthetic datasets. The results show that our approach is able to find complex matches with high accuracy, similar to that obtained by more elaborated (hybrid) approaches, despite using only evidence based on the data instances.     

PaMS: A component-based service for finding the missing full text of articles cataloged in a digital library

Providing access to the full text of cataloged articles is a highly desirable feature for a digital library. However, in many such systems, not all metadata records have (a direct pointer to) a corresponding full-text document. In this article, we present PaMS: a new service for finding the missing full text of articles cataloged in a digital library. This service is implemented as a software component in order to be readily deployable to existing systems. It works as a parameterized meta-search engine and allows digital library administrators to easily set up a search strategy, i.e., a list of existing search engines to be queried for the missing full text, as well as the filtering and ranking policies to be applied to the results retrieved by each search engine. We evaluate our service with respect to its effectiveness and efficiency with collections from two distinct fields: computer science and biomedical and life sciences. Our results attest the effectiveness of PaMS for finding missing full-text documents as well as other relevant material while keeping its overall execution time at a reasonable level.     

Biodiversity of Freshwater Diatom Communities during 1000 Years of Metal Mining, Land Use, and Climate Change in Central Sweden

We subjected a unique set of high-quality paleoecological data to statistical modeling to examine if the biological richness and evenness of freshwater diatom communities in the Falun area, a historical copper (Cu) mining region in central Sweden, was negatively influenced by 1000 years of metal exposure. Contrary to ecotoxicological predictions, we found no negative relation between biodiversity and the sedimentary concentrations of eight metals. Strikingly, our analysis listed metals (Co, Fe, Cu, Zn, Cd, Pb) or the fractional land cover of cultivated crops, meadow, and herbs indicating land disturbance as potentially promoting biodiversity. However, correlation between metal- and land-cover trends prevented concluding which of these two covariate types positively affected biodiversity. Because historical aqueous metal concentrations-inferred from solid-water partitioning-approached experimental toxicity thresholds for freshwater algae, positive effects of metal mining on biodiversity are unlikely. Instead, the positive relationship between biodiversity and historical land-cover change can be explained by the increasing proportion of opportunistic species when anthropogenic disturbance intensifies. Our analysis illustrates that focusing on the direct toxic effects of metals alone may yield inaccurate environmental assessments on time scales relevant for biodiversity conservation.     

Diagnosis of bone metastasis by thermography

The uptake of D-[(14)C]mannose by adult rat kidney cortex slices has been examined. The process involved appeared to be saturable and oxygen dependent and to be inhibited by glucose, galactose, chi-methyl-D-glucoside, and phlorizin. Extensive metabolism of the sugar occurred. (14)CO(2) was produced to an extent comparable to that from D-glucose. Radioactive compounds accumulated in the tissue, approximately 50% of which were in the form of phosphorylated or other polar intermediates. The remaining neutral fraction consisted of mannose with a small amount of label in glucose and an unidentified compound which behaves like an alditol. Mannose concentration in the intracellular fluid was never greater than that of the medium.