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471.
Object-oriented databases (OODBs) provide an effective means for capturing complex data and semantic relationships underlying many real-world database applications. Because users' interactions with databases have increased significantly in today's era of client–server computing, it is important to examine users' ability to interact with such databases. We investigated a number of factors that potentially affect performance in writing queries on an OODB. First, we evaluated the utility of graphical and textual schemas associated with emerging OODBs from the perspective of database querying. Second, we examined the use of two different strategies (navigation and join) that could be used in writing OODB queries. Third, we examined a number of factors that potentially contribute to the complexity of an OODB query.Our exploratory study examined the performance of 20 graduate students in an experiment in which each participant wrote queries for two problems, one using a graphical OODB schema and the other a textual OODB schema. The participants had no prior exposure to the object-oriented data model. We found that there was no difference in query writing performance (either accuracy or time) using the graphical and textual schemas. Examination of query strategy revealed that a significant number of participants used a join strategy, rather than the navigation strategy that matches the database structure. Use of the join strategy resulted in significantly less accurate and slower query writing than did the navigation strategy. From the viewpoint of complexity, the number of objects referenced in a query, the number of starting points in the from clause, and the presence of special operators influenced both the accuracy and time of query writing. 相似文献
472.
Iris Arad 《Machine Translation》1991,6(4):247-263
This article provides an overview of the BITS Hebrew-English bibliographic translation system developed at CCL, UMIST. This is an experimental machine translation system for translating bibliographic references in which first generation translation techniques are combined with more recent developments in computer science. The experiment explores whether simple techniques can be used to achieve usable translations in this context. The input material, the pre-editing system and the general architecture of the BITS system are described and evaluated in view of current MT research. 相似文献
473.
Iris Bertani Maristella Coglievina Paolo Zaccaria Raffaella Klima Carlo V. Bruschi 《Yeast (Chichester, England)》1995,11(12):1187-1194
We report the sequence of an 11·1 kb fragment located on the left arm of chromosome VII of Saccharomyces cerevisiae. By sequence analysis we have detected six open reading frames (ORFs) longer than 300 bp, which cover 87% of the entire sequence. ORF G1645 is 100% identical to the KEM1 gene, also identified as DST2, XRN1, SEP1 and RAR5, while G1648 is 100% identical to the NSP49 or NUP49 gene. ORF G1642 shares some identity with a hypothetical protein of Caenorhabditis elegans, while the other four ORFs show no significant homology to known proteins. The sequence has been submitted to the EMBL data library under Accession Number X84705. 相似文献
474.
Maristella Coglievina Iris Bertani Raffaella Klima Paolo Zaccaria Carlo Vito Bruschi 《Yeast (Chichester, England)》1995,11(8):767-774
We report the sequence of a 7941 bp DNA fragment from the left arm of chromosome VII of Saccharomyces cerevisiae which contains four open reading frames (ORFs) of greater than 100 amino acid residues. ORF biC834 shows 100% bp identity with the recently identified multicopy suppressor gene of the pop2 mutation (MPT5); its deduced protein product carries an eight-repeat domain region, homologous to that found in the hypothetical regulatory YGL023 protein of S. cerevisiae and the Pumilio protein of Drosophila. ORF biE560 protein exhibits patterns typical of serine/threonine protein kinases, with which it shares high degrees of homology. The complete nucleotide sequence was submitted to the EMBL Data Library under Accession Number X83690. 相似文献
475.
Injection of hot water in an aquifer may induce dissolution and precipitation of minerals. The importance of these phenomena is examined with the help of numerical experiments. The mathematical model is the result of the coupling of a fluid flow and mass transport code (Goblet, 1981) with a geochemical speciation code (Coudrain-Ribstein, 1988). Simulations are presented for the case where water is injected at 60°C. 相似文献
476.
Peter Frach Dr. Daniel Glöß Dr. Michael Vergöhl Dr. Kerstin Hund-Rinke Dr. Iris Trick Dr. 《真空研究与实践》2007,19(6):20-27
Crystalline TiO2 layers show interesting properties for different applications. Rutile layers can be used as optical layers with high refractive index and as transparent protective layers with good mechanical properties. Both, anatase and rutile are photo-semiconductors and exhibit in a different degree photocatalytic, photo-induced hydrophilic and antifogging properties. For a better control of the TiO2 deposition and thin film properties a special deposition system has been developed: a reactive pulse magnetron sputtering (PMS) system. Layers with different content of crystalline phases were deposited at dynamic deposition rates of about 45 nm·m/min (corresponding to about 160 nm/min in a stationary coating system). Moreover, the anionic doping of the layers succeeded by nitrogen as well as the cationic doping by different metals. The layer structure was determined by XRD. Furthermore, the following properties connected with photo-induced hydrophilicity or photocatalysis were studied: the photo-induced decrease of the water contact angle, the decomposition of methylene blue and lumogen orange as well as the inhibition of algae and bacteria. By doping the layers some of these properties can be improved significantly in comparison to undoped titanium oxide. Some doped layers showed a high activity also under visible irradiation only without UV. 相似文献
477.
Juan Manuel Del Fresno Carlos Escott Iris Loira Francisco Carrau Rafael Cuerda Rmi Schneider María Antonia Bauelos Carmen Gonzlez Jos Antonio Surez-Lepe Antonio Morata 《International journal of molecular sciences》2021,22(4)
Hanseniaspora vineae is a non-Saccharomyces yeast that has a powerful impact on the sensory profile of wines. Its effect on the aromatic profile of non-aromatic grape varieties, such as Albillo Mayor (Vitis vinifera, L), during vinification is a useful biotechnology to improve sensory complexity. Fermentation in steel barrels using Hanseniaspora vineae and sequential inoculation with Saccharomyces cerevisiae have been used to study the formation of terpenes and cell lysis in the production of Albillo white wines. The GC-MS analysis profile shows a significant effect of H. vineae fermentation on the contents of terpenes (≈×3), mainly in linalool (>×3), β-citronellol (>×4), geraniol (>×2) and α-terpineol (≈×2). The contents of several polyoxygenated terpenes and some volatile phenols with a spicy aroma were increased during fermentation. In summary, Hanseniaspora vineae releases a large number of cell wall polysaccharides during fermentation that affect wine palatability and structure. Hanseniaspora vineae is a powerful bio-tool to enhance the fruitiness, floral notes and freshness in non-aromatic white varieties. 相似文献
478.
479.
Andrea Katharina Lindner Gert Schachtner Gennadi Tulchiner Martin Thurnher Gerold Untergasser Peter Obrist Iris Pipp Fabian Steinkohl Wolfgang Horninger Zoran Culig Renate Pichler 《International journal of molecular sciences》2021,22(2)
Lynch syndrome, known as hereditary nonpolyposis colorectal cancer (HNPCC), is an autosomal-dominant familial cancer syndrome with an increased risk for urothelial cancer (UC). Mismatch repair (MMR) deficiency, due to pathogenic variants in MLH1, MSH2, MSH6, and PMS2, and microsatellite instability, are known for development of Lynch syndrome (LS) associated carcinogenesis. UC is the third most common cancer type in LS-associated tumors. The diversity of germline variants in the affected MMR genes and their following subsequent function loss might be responsible for the variation in cancer risk, suggesting an increased risk of developing UC in MSH2 mutation carriers. In this review, we will focus on LS-associated UC of the upper urinary tract (UUT) and bladder, their germline profiles, and outcomes compared to sporadic UC, the impact of genetic testing, as well as urological follow-up strategies in LS. In addition, we present a case of metastatic LS-associated UC of the UUT and bladder, achieving complete response during checkpoint inhibition since more than 2 years. 相似文献
480.
Matthias Franz Britta Mörchen Carsten Degenhart Daniel Gülden Oleksandr Shkura Dr. Dirk Wolters Dr. Uwe Koch Dr. Bert Klebl Prof. Dr. Raphael Stoll Dr. Iris Helfrich Prof. Dr. Jürgen Scherkenbeck 《ChemMedChem》2021,16(16):2504-2514
Oncogenic Ras proteins are implicated in the most common life-threatening cancers. Despite intense research over the past two decades, the progress towards small-molecule inhibitors has been limited. One reason for this failure is that Ras proteins interact with their effectors only via protein-protein interactions, which are notoriously difficult to address with small organic molecules. Herein we describe an alternative strategy, which prevents farnesylation and subsequent membrane insertion, a prerequisite for the activation of Ras proteins. Our approach is based on sequence-selective supramolecular receptors which bind to the C-terminal farnesyl transferase recognition unit of Ras and Rheb proteins and covalently modify the essential cysteine in the so-called CaaX-box. 相似文献