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Retrieval
Kinds of Retrieval Terms modified by Retrieval Selected AbstractsMEMORY ORGANIZATION AS THE MISSING LINK BETWEEN CASE-BASED REASONING AND INFORMATION RETRIEVAL IN BIOMEDICINECOMPUTATIONAL INTELLIGENCE, Issue 3-4 2006Isabelle Bichindaritz Mémoire proposes a general framework for reasoning from cases in biology and medicine. Part of this project is to propose a memory organization capable of handling large cases and case bases as occur in biomedical domains. This article presents the essential principles for an efficient memory organization based on pertinent work in information retrieval (IR). IR systems have been able to scale up to terabytes of data taking advantage of large databases research to build Internet search engines. They search for pertinent documents to answer a query using term-based ranking and/or global ranking schemes. Similarly, case-based reasoning (CBR) systems search for pertinent cases using a scoring function for ranking the cases. Mémoire proposes a memory organization based on inverted indexes which may be powered by databases to search and rank efficiently through large case bases. It can be seen as a first step toward large-scale CBR systems, and in addition provides a framework for tight cooperation between CBR and IR. [source] Integrating Web-Based Documents, Shared Knowledge Bases, and Information Retrieval for User HelpCOMPUTATIONAL INTELLIGENCE, Issue 1 2000Doug Skuce We describe a prototype system, IKARUS, with which we investigated the potential of integrating web-based documents, shared knowledge bases, and information retrieval for improving knowledge storage and retrieval. As an example, we discuss how to implement both a user manual and an online help system as one system. The following technologies are combined: a web-based design, a frame-based knowledge engine, use of an advanced full-text search engine, and simple techniques to control terminology. We have combined graphical browsing with several unusual forms of text retrieval,for example, to the sentence and paragraph level. [source] Retrieval of first genome data for rice cluster I methanogens by a combination of cultivation and molecular techniquesFEMS MICROBIOLOGY ECOLOGY, Issue 2 2005Christoph Erkel Abstract We report first insights into a representative genome of rice cluster I (RC-I), a major group of as-yet uncultured methanogens. The starting point of our study was the methanogenic consortium MRE50 that had been stably maintained for 3 years by consecutive transfers to fresh medium and anaerobic incubation at 50 °C. Process-oriented measurements provided evidence for hydrogenotrophic CO2 -reducing methanogenesis. Assessment of the diversity of consortium MRE50 suggested members of the families Thermoanaerobacteriaceae and Clostridiaceae to constitute the major bacterial component, while the archaeal population was represented entirely by RC-I. The RC-I population amounted to more than 50% of total cells, as concluded from fluorescence in situ hybridization using specific probes for either Bacteria or Archaea. The high enrichment status of RC-I prompted construction of a large insert fosmid library from consortium MRE50. Comparative sequence analysis of internal transcribed spacer (ITS) regions revealed that three different RC-I rrn operon variants were present in the fosmid library. Three, approximately 40-kb genomic fragments, each representative for one of the three different rrn operon variants, were recovered and sequenced. Computational analysis of the sequence data resulted in two major findings: (i) consortium MRE50 most likely harbours only a single RC-I genotype, which is characterized by multiple rrn operon copies; (ii) seven genes were identified to possess a strong phylogenetic signal (eIF2a, dnaG, priA, pcrA, gatD, gatE, and a gene encoding a putative RNA-binding protein). Trees exemplarily computed for the deduced amino acid sequences of eIF2a, dnaG, and priA corroborated a specific phylogenetic association of RC-I with the Methanosarcinales. [source] Coherence and correspondence criteria for rationality: experts' estimation of risks of sexually transmitted infectionsJOURNAL OF BEHAVIORAL DECISION MAKING, Issue 3 2005Mary B. Adam Abstract The aim of this study is to examine both coherence and correspondence criteria for rationality in experts' judgments of risk. We investigated biases in risk estimation for sexually transmitted infections (STIs) predicted by fuzzy-trace theory, i.e., that specific errors would occur despite experts' knowledge of correct responses. One hundred twenty professionals with specific knowledge of STI risks in adolescents were administered a survey questionnaire to test predictions concerning: knowledge deficits (producing underestimation of risks); gist-based representation of risk categories (producing overestimation of condom effectiveness); retrieval failure for risk knowledge (producing lower risk estimates); and processing interference in combining risk estimates (producing biases in post-test diagnosis of infection). Retrieval was manipulated by asking estimation questions that "unpacked" the STI category into infection types or did not specify infection types. Other questions differentiated processing biases from knowledge deficits or retrieval failure by directly providing requisite knowledge. Experts' knowledge of STI transmission and infection risks was verified empirically. Nevertheless, under predictable conditions, they misestimated risk, overestimated the effectiveness of condoms, and also suffered from processing biases. When questions provided better retrieval supports (unpacked format), risk estimates improved. Biases were linked to gist representations, retrieval failures, and processing errors, as opposed to knowledge about STIs. Results support fuzzy-trace theory's dual-process assumptions that different types of errors are dissociated from one another, and separate failures of coherence and correspondence among the same sample of experts. Copyright © 2005 John Wiley & Sons, Ltd. [source] Retrieval of spectral and dynamic properties from two-dimensional infrared pump-probe experimentsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 9 2008Riccardo Chelli Abstract We have developed a fitting algorithm able to extract spectral and dynamic properties of a three level oscillator from a two-dimensional infrared spectrum (2D-IR) detected in time resolved nonlinear experiments. Such properties go from the frequencies of the ground-to-first and first-to-second vibrational transitions (and hence anharmonicity) to the frequency-fluctuation correlation function. This last is represented through a general expression that allows one to approach the various strategies of modeling proposed in the literature. The model is based on the Kubo picture of stochastic fluctuations of the transition frequency as a result of perturbations by a fluctuating surrounding. To account for the line-shape broadening due to pump pulse spectral width in double-resonance measurements, we supply the fitting algorithm with the option to perform the convolution of the spectral signal with a Lorentzian function in the pump-frequency dimension. The algorithm is tested here on 2D-IR pump-probe spectra of a Gly-Ala dipeptide recorded at various pump-probe delay times. Speedup benchmarks have been performed on a small Beowulf cluster. The program is written in FORTRAN language for both serial and parallel architectures and is available free of charge to the interested reader. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Toward A Common Language: Proposed Index Categories to Enhance Dissemination and Retrieval of Interior Design ScholarshipJOURNAL OF INTERIOR DESIGN, Issue 2 2004Stephanie A. Clemons Ph.D. ABSTRACT Dissemination and retrieval of scholarship within any given discipline and profession are necessary when defining the body of knowledge. Effective dissemination and retrieval of scholarly work is dependent upon selecting appropriate index categories to describe a publication. Therefore, an accurate categorization system is critical in guiding that dissemination/retrieval process necessary when building a comprehensive body of knowledge for a discipline and profession. The goal of this research was to develop a proposed categorization for systematizing dissemination and retrieval of scholarly work for the discipline and profession of interior design. As a first step in achieving this goal, this study intended to develop a revised categorization for systematizing the dissemination and retrieval of scholarship for the Journal of lnterior Design. The proposed categories would contribute to the interior design discipline and profession by providing: 1) consistency in subject matter categorization for interior design scholarship; 2) a common language within the shared body of knowledge of interior design that includes such disciplines as art, architecture, and social sciences; and 3) clearer identification of topics for future scholarship within the knowledge base for interior design and related areas. For this study, a framework developed by Marshall-Baker (2000) was used in the development of criteria and analysis. Her framework depicted overlapping and unique knowledge within and among fields related to interior design: art, architecture, and social science. Findings supported Marshall-Baker's research and further identified a common language among elated disciplines. This common language enhances communication among publishers, educators, researchers, practitioners, students, and employers. The body of knowledge in interior design will continue to require definition as new knowledge emerges and refinement takes place. Consistent index categorization of scholarship will enable scholars and reviewers of scholarly work to trace the evolution of research on particular topics, thereby assessing the contribution of scholarly work to the expansion and application of the body of knowledge in interior design. The findings offer a proposal for key words and categories identiking interior design scholarship for the purpose of dissemination and retrieval, as well as, providing a platform for common language across related disciplines. [source] An Enhanced Device for Transluminal Retrieval of Vascular Stents Without Surgical Procedures: Experimental StudiesJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2010MASAYUKI TSUCHIDA M.D. Background: Although efforts have been focused on developing endovascular procedures by which intravascular devices such as stents could be effectively deployed, few data exist regarding devices for the nonsurgical retrieval of deployed stents. Therefore, we designed to enable retrieval of deployed stents without a surgical procedure. Methods: The device consisted of four components: ultra-low profile forceps with 2.0 mm in diameter, conducting shaft with 1.8 mm in diameter, control handle by which the forceps is opened or closed, and a covering sheath. This device was designed to advance into the vessel lumen along a 0.014-inch guidewire by over the wire fashion. Results: The forceps could firmly catch nonexpanded as well as expanded tubular-type stents with open cells in an in vitro model that was 4.0 mm in diameter. Then, we used this device in porcine renal arteries with 2.5,5.0 mm in diameter. At first, a fragmented 0.014-inch guidewire could be safely removed without vessel damage that was confirmed by intravascular ultrasound. This device could successfully remove four of five inappropriately and 11 of 14 appropriately deployed stents. Under these conditions, intravascular ultrasound demonstrated minor vessel wall dissection in two-third of cases. Conclusions: These results demonstrate that the present device can be used for transluminal removal of foreign bodies such as nonexpanded as well as expanded stents in acute phase. Further miniaturization may enable using this type of device in the renal as well as coronary arteries. (J Interven Cardiol 2010;23:264,270) [source] Percutaneous Retrieval of a Broken Catheter from the Left Atrium in an AdultJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2002ANGELO BRUNO RAMONDO M.D. We performed a percutaneous retrieval of a broken catheter from the left atrium in an adult patient using transseptal left heart catheterization and a helical basket guidewire. To our knowledge, this is the first description of such a therapeutical option for a foreign body lodged in the left atrium of an adult patient. [source] Percutaneous Retrieval of a Wallstent from the Pulmonary Artery Following Stent Migration from the Iliac VeinJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 2 2002RAJIV M. ASHAR M.D. Wallstents are being used increasingly in conjunction with balloon dilatation for treatment of iliac vein stenosis. Stent misplacement or migration is a complication of the procedure, and may be symptomatic and warrant repositioning or removal. We report the case of a patient whose iliac vein stenosis was managed with two overlapping Wallstents and was complicated by embolization of one stent into the right ventricle (RV) and the other to the pulmonary artery (PA). This article illustrates percutaneous endovascular removal of a migrated stent from the PA using a jugular and femoral approach. [source] Interactive Information Retrieval in Digital EnvironmentsJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2009Pia Borlund [source] Task-based information retrieval: Structuring undergraduate history essays for better course evaluation using essay-type visualizationsJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2007John E. Leide When domain novices are in C.C. Kuhlthau's (1993) Stage 3, the exploration stage of researching an assignment, they often do not know their information need; this causes them to go back to Stage 2, the topic-selection stage, when they are selecting keywords to formulate their query to an Information Retrieval (IR) system. Our hypothesis is that instead of going backward, they should be going forward toward a goal state,the performance of the task for which they are seeking the information. If they can somehow construct their goal state into a query, this forward-looking query better operationalizes their information need than does a topic-based query. For domain novice undergraduates seeking information for a course essay, we define their task as selecting a high-impact essay structure which will put the students' learning on display for the course instructor who will evaluate the essay. We report a study of first-year history undergraduate students which tested the use and effectiveness of "essay type" as a task-focused query-formulation device. We randomly assigned 78 history undergraduates to an intervention group and a control group. The dependent variable was essay quality, based on (a) an evaluation of the student's essay by a research team member, and (b) the marks given to the student's essay by the course instructor. We found that conscious or formal consideration of essay type is inconclusive as a basis of a task-focused query-formulation device for IR. [source] Strategic help in user interfaces for information retrievalJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 5 2002Giorgio Brajnik Although no unified definition of the concept of search strategy in Information Retrieval (IR) exists so far, its importance is manifest: nonexpert users, directly interacting with an IR system, apply a limited portfolio of simple actions; they do not know how to react in critical situations; and they often do not even realize that their difficulties are due to strategic problems. A user interface to an IR system should therefore provide some strategic help, focusing user's attention on strategic issues and providing tools to generate better strategies. Because neither the user nor the system can autonomously solve the information problem, but they complement each other, we propose a collaborative coaching approach, in which the two partners cooperate: the user retains the control of the session and the system provides suggestions. The effectiveness of the approach is demonstrated by a conceptual analysis, a prototype knowledge-based system named FIRE, and its evaluation through informal laboratory experiments. [source] Call for papers: Special topics issue of JASIST: Web Retrieval and MiningJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 7 2001Article first published online: 26 APR 200 [source] The Radical Political Philosophy of Thomas Jefferson: An Essay in RetrievalMIDWEST STUDIES IN PHILOSOPHY, Issue 1 2004RICHARD K. MATTHEWS First page of article [source] The relative contributions of the Cattell-Horn-Carroll cognitive abilities in explaining writing achievement during childhood and adolescence,PSYCHOLOGY IN THE SCHOOLS, Issue 2 2008Randy G. Floyd This study examined the relative contributions of measures of Cattell-Horn-Carroll (CHC) cognitive abilities in explaining writing achievement. Drawing from samples that covered the age range of 7 to 18 years, simultaneous multiple regression was used to regress scores from the Woodcock-Johnson III (WJ III; Woodcock, McGrew, & Mather, 2001) that represent CHC broad and narrow abilities onto the WJ III Basic Writing Skills and Written Expression cluster scores. At most age levels, Comprehension-Knowledge demonstrated moderate to strong effects on both writing clusters, Processing Speed demonstrated moderate effects on Basic Writing Skills and moderate to strong effects on Written Expression, and Short-Term Memory demonstrated moderate effects. At the youngest age levels, Long-Term Retrieval demonstrated moderate to strong effects on Basic Writing Skills and moderate effects on Written Expression. Auditory Processing, and Phonemic Awareness demonstrated moderate effects on only Written Expression at the youngest age levels and at some of the oldest age levels. Fluid Reasoning demonstrated moderate effects on both writing clusters only during some of the oldest age levels. Visual-Spatial Thinking primarily demonstrated negligible effects. The results provide insights into the cognitive abilities most important for understanding the writing skills of children during the school-age years. © 2008 Wiley Periodicals, Inc. [source] Relations between measures of Cattell-Horn-Carroll (CHC) cognitive abilities and mathematics achievement across the school-age yearsPSYCHOLOGY IN THE SCHOOLS, Issue 2 2003RANDY G. FLOYD Cognitive clusters from the Woodcock-Johnson III (WJ III) Tests of Cognitive Abilities that measure select Cattell-Horn-Carroll broad and narrow cognitive abilities were shown to be significantly related to mathematics achievement in a large, nationally representative sample of children and adolescents. Multiple regression analyses were used to predict performance on the Math Calculation Skills and Math Reasoning clusters from the WJ III Tests of Achievement for 14 age groups ranging in age from 6 to 19 years. Comprehension-Knowledge (Gc) demonstrated moderate relations with Math Calculation Skills after the early school-age years and moderate to strong relations with Math Reasoning. Fluid Reasoning (Gf), Short-term Memory (Gsm), and Working Memory generally demonstrated moderate relations with the mathematics clusters. Processing Speed (Gs) demonstrated moderate relations with Math Reasoning during the elementary school years and moderate to strong relations with Math Calculation Skills. During the earliest ages of the analysis, Long-term Retrieval (Glr) demonstrated moderate relations with the mathematics clusters, and Auditory Processing (Ga) demonstrated moderate relations with Math Calculation Skills. Visual-Spatial Thinking (Gv) generally demonstrated nonsignificant relations with the mathematics clusters. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 155,171, 2003. [source] Ovum Pick-up in Sheep: a Comparison between Different Aspiration Devices for Optimal Oocyte RetrievalREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2006C Rodríguez Contents In vivo ovum pick-up (OPU) in sheep may be improved with a proper choice of aspiration elements (needle and tubing) and aspiration vacuum pressure. In the present study, two experiments were carried out. In Expt 1, visible follicles in ovaries of slaughtered ewes (treated separately according to their diameters: small <3 mm, medium 3,5 mm and large >5 mm) were aspirated using different combinations of the three studied factors such as aspiration flow rate (10, 20, 30, 40 and 50 ml water/min), needle gauge (18 and 20 G) and tubing inner diameter (1, 2 or 3 mm internal diameter). In Expt 2, a study with two 18 G needles of different lengths (18 G: 82 mm; 18 GL: 600 mm) was carried out, using ovaries obtained post-mortem, and performing in vivo laparoscopic follicular aspiration on ewes. We considered good quality oocytes as those with both complete compact cumulus and a homogeneous cytoplasm. Recovery rate, proportion of good quality oocytes (good quality oocytes/100 oocytes recovered) and overall efficiency (good quality oocytes/100 follicles aspirated) were noted. In Expt 1, aspiration flow rate affect remarkable proportion of good quality oocytes (69.5%, 50.5%, 44.8%, 36.5% and 28.3% for flows from 10 to 50 ml/min respectively, p < 0.05). Needle gauge did not affect aspiration device efficiency. Thin and intermediate tubings were more effective (overall efficiency rates: 34.9%, 32.3% and 28.1% for 1, 2 and 3 mm respectively, p < 0.05). Follicle size did not affect recovery rate, but proportion of good quality oocytes was higher for large (77.9%) and medium (64.4%) follicles (p < 0.05). Finally, some combinations of the aspiration device showed greater effectiveness. In Expt 2, needle length did not influence recovery rate, but good quality oocytes rate was significantly modified both post-mortem and in vivo (good quality rate for 18 G vs 18 GL needles: 69.5% vs 47.7% and 58.1% vs 25.4%, post-mortem and in vivo respectively, p < 0.05). We conclude that low-aspiration flow rates (10 and 20 ml/min) with thin or intermediate tubings (1 and 2 mm), and any short needle (18 G or 20 G) are the most adequate aspiration factors for OPU in sheep. [source] Pushing the Dead into the Next Reproductive Frontier: Post Mortem Gamete Retrieval under the Uniform Anatomical Gift ActTHE JOURNAL OF LAW, MEDICINE & ETHICS, Issue 2 2009Bethany SpielmanArticle first published online: 3 JUN 200 In re Matter of Daniel Thomas Christy authorized post mortem gamete retrieval under the most recent revision of the Uniform Anatomical Gift Act. This article recommends that the National Conference of Commissioners on Uniform State Laws explicitly address the issue of post mortem gamete retrieval for reproductive purposes; that legislators specify whether their states will follow the Christy ruling; and that ethics committees and consultants prepare for the questions about human identity and self determination that post mortem gamete retrieval raises. [source] Pulmonary Recovery After Rigid Bronchoscopic Retrieval of Airway Foreign BodyTHE LARYNGOSCOPE, Issue 2 2007Man Ki Chung MD Abstract Objective: The aim of this study was to determine how long postoperative pulmonary care is needed in patients after rigid bronchoscopic retrieval of foreign body from the airway and to identify the factors affecting pulmonary recovery. Materials and Method: A retrospective review of 98 pediatric patients who had foreign body removed from the airway by rigid bronchoscopic procedure was conducted. After the removal of the foreign body, the time required for complete clinical and radiologic pulmonary recovery was reviewed for each subject. Factors examined included age, sex, preoperative symptoms, preoperative radiologic findings, duration between the aspiration event and treatment, the type of foreign body, the location of foreign body impaction, operation time, immediate postoperative radiologic changes, and treatment outcome. Results: More than 1 week for the complete pulmonary recovery was required in 25 (25.5%) cases, whereas 74.5% of subjects fully recovered within 1 week after the removal of foreign body. In the univariate analysis, preoperative inflammatory symptoms, and radiologic findings, an operation time of over 50 minutes and the aggravation of immediate postoperative radiologic findings predicted a delayed pulmonary recovery (more than 1 week). In the multivariate analysis, three of four variables previously noted, except preoperative inflammatory symptoms, showed significant predictability for a delayed pulmonary recovery. Conclusion: The recovery time of more than 1 week after rigid bronchoscopic retrieval of airway foreign body was associated with preoperative inflammatory findings by radiologic study, a prolonged procedure over 50 minutes, and aggravation of the immediate postoperative radiologic findings. Therefore, long-term pulmonary care is required for this group of patients. [source] Retrieval of microphysical and morphological properties of volcanic ash plumes from satellite data: Application to Mt Ruapehu, New ZealandTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 576 2001A. J. Prata Abstract A quantitative analysis of the properties of several Mt Ruapehu, New Zealand, ash plumes has been performed using multispectral satellite data from the AVHRR-2 and ATSR-2 instruments. The analysis includes: identification of the plume from background clouds using the ,reverse' absorption effect in the thermal channels: modelling and retrieval of particle sizes; determination of the plume height from cloud shadows, stereoscopy and meteorological data; and estimates of the mass of fine particles (radii less than 10 ,m). A new spectral technique for identifying opaque, silica-rich ash clouds is demonstrated by utilizing the near-infrared (1.6 ,m) and visible (0.67 ,m) channels of the ATSR-2, and the optical properties of a simple volcanic cloud are presented for use in radiative transfer studies. It is found that the Ruapehu eruption cloud contained silica-rich ash particles with radii generally less than a few micrometres. The distribution of fine particles is monomodal with a dominant mode peak of about 3 ,m radius. Mass loadings of fine particles are found to be in the range ,1 to ,7 mg m,3, and are consistent with estimates of mass loadings of volcanic clouds from eruptions of other volcanoes. The height of the plume top, derived from radiosonde data and plume-top temperatures in the opaque regions, was found to be between 7.5 and 8.5 km, while the plume thickness was estimated to be between 1.5 and 3 km. Cloud height derived from ATSR-2 stereoscopy on a different plume gave heights in the range 5 to 8 km. The results of this study provide important information on the optical properties of nascent volcanic eruption plumes. This information may prove useful in determining the potential effects of volcanic clouds on local climate, and in assessing any hazard to aviation. [source] The Perils of Organ RetrievalAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2007G. B. Klintmalm The tragedy in Michigan reminds us to remember the people who put their lives on the line to help others to live, and the high price that they and their families sometimes have to pay. See also tribute by Merion in this issue on page 2060. [source] Visuo-spatial working memory in navigationAPPLIED COGNITIVE PSYCHOLOGY, Issue 1 2002Sharin Garden Two experiments employed dual task techniques to explore the role of working memory in route learning and subsequent route retrieval. Experiment 1 involved contrasting performance of two groups of volunteers respectively learning a route from a series of map segments or a series of visually presented nonsense words. Both groups performed learning and recognition under articulatory suppression or concurrent spatial tapping. Both concurrent tasks had an overall disruptive effect on each learning task. However, spatial tapping disrupted route recognition rather more than did articulatory suppression, while the nonsense word recognition was impaired more by articulatory suppression than by concurrent spatial tapping. Experiment 2 again used dual task methodology, but explored route learning by asking volunteers to follow the experimenter through the winding streets of a medieval European town centre. Retrieval involved following the same route while the experimenter followed and noted errors in navigation. Overall the results partially replicated those of Experiment 1 in that both concurrent tasks interfered with route learning. However, volunteers with high spatial ability appeared more affected by the concurrent spatial tapping task, whereas low spatial subjects appeared more affected by the concurrent articulatory suppression task. Results are interpreted to suggest that different aspects of working memory are involved in learning a route from a map with a greater emphasis on visuo-spatial resources, but in tasks set in real environments where many cues of a varied nature are available, only high spatial ability subjects appear to rely heavily upon the visuospatial component of working memory. Copyright © 2002 John Wiley & Sons, Ltd. [source] Semantic Retrieval in DNA-Based Memories with Gibbs Energy ModelsBIOTECHNOLOGY PROGRESS, Issue 1 2006Andrew Neel At least three types of associative memories based on DNA-affinity have been proposed. Previously, we have quantified the quality of retrieval of genomic and abiotic information in simulation by comparison to state-of-the-art symbolic methods available, such as LSA (Latent Semantic Analysis). Their performance is poor when the evaluation criterion for DNA-affinity is a simple approximation of the Gibbs energy that governs duplex formation for retrievals. Here, we use a more realistic approximation of the Gibbs energy to improve semantic retrievals in DNA memories. Their performance is much closer to that of LSA, according to human expert ratings. With more realistic approximations of DNA affinity, performance is expected to improve for other, more adaptive associative memories with compaction in silico, and even more so with actual DNA molecules in vitro. [source] Axillary staging during surgery for breast cancerBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2007C. K. Axelsson Background: Axillary lymph node status remains the single most important prognostic parameter in patients with breast cancer. In approximately half of operations sentinel lymph node biopsy cannot be employed and axillary dissection is indicated. Retrieval of ten nodes has hitherto been considered sufficient, but it remains questionable whether the removal of more lymph nodes might improve staging. Methods: Data from 31 679 breast cancer operations in Denmark were analysed. Results: The number of axillary lymph nodes retrieved was an independent and strong predictor of node positivity. The more lymph nodes retrieved, the better the staging of the disease; this was evident for all sizes of tumour. Dissection of 20 or more nodes rather than ten to 14 increased the probability of node positivity from 14·2 to 25·9 per cent for 1,5-mm tumours, from 38·6 to 47·9 per cent for 11,20-mm tumours, and from 80·6 to 90·0 per cent for tumours with diameter greater than 50 mm. Conclusion: The number of metastatic lymph nodes increased as more nodes were retrieved. These findings underline the need for high-quality specialist surgical and pathological services in breast cancer treatment. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] Reviving Inert Knowledge: Analogical Abstraction Supports Relational Retrieval of Past EventsCOGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 8 2009Dedre Gentner Abstract We present five experiments and simulation studies to establish late analogical abstraction as a new psychological phenomenon: Schema abstraction from analogical examples can revive otherwise inert knowledge. We find that comparing two analogous examples of negotiations at recall time promotes retrieving analogical matches stored in memory,a notoriously elusive effect. Another innovation in this research is that we show parallel effects for real-life autobiographical memory (Experiments 1,3) and for a controlled memory set (Experiments 4 and 5). Simulation studies show that a unified model based on schema abstraction can capture backward (retrieval) effects as well as forward (transfer) effects. [source] An Activation-Based Model of Sentence Processing as Skilled Memory RetrievalCOGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 3 2005Richard L. Lewis Abstract We present a detailed process theory of the moment-by-moment working-memory retrievals and associated control structure that subserve sentence comprehension. The theory is derived from the application of independently motivated principles of memory and cognitive skill to the specialized task of sentence parsing. The resulting theory construes sentence processing as a series of skilled associative memory retrievals modulated by similarity-based interference and fluctuating activation. The cognitive principles are formalized in computational form in the Adaptive Control of Thought,Rational (ACT,R) architecture, and our process model is realized in ACT,R. We present the results of 6 sets of simulations: 5 simulation sets provide quantitative accounts of the effects of length and structural interference on both unambiguous and garden-path structures. A final simulation set provides a graded taxonomy of double center embeddings ranging from relatively easy to extremely difficult. The explanation of center-embedding difficulty is a novel one that derives from the model' complete reliance on discriminating retrieval cues in the absence of an explicit representation of serial order information. All fits were obtained with only 1 free scaling parameter fixed across the simulations; all other parameters were ACT,R defaults. The modeling results support the hypothesis that fluctuating activation and similarity-based interference are the key factors shaping working memory in sentence processing. We contrast the theory and empirical predictions with several related accounts of sentence-processing complexity. [source] In situ and remote-sensing measurements of the mean microphysical and optical properties of industrial pollution aerosol during ADRIEXTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue S1 2007S. R. Osborne Abstract We present a summary of the principal physical and optical properties of aerosol particles using the FAAM BAE-146 instrumented aircraft during ADRIEX between 27 August and 6 September 2004, augmented by sunphotometer, lidar and satellite retrievals. Observations of anthropogenic aerosol, principally from industrial sources, were concentrated over the northern Adriatic Sea and over the Po Valley close to the aerosol sources. An additional flight was also carried out over the Black Sea to compare east and west European pollution. Measurements show the single-scattering albedo of dry aerosol particles to vary considerably between 0.89 and 0.97 at a wavelength of 0.55 µm, with a campaign mean within the polluted lower free troposphere of 0.92. Although aerosol concentrations varied significantly from day to day and during individual days, the shape of the aerosol size distribution was relatively consistent through the experiment, with no detectable change observed over land and over sea. There is evidence to suggest that the pollution aerosol within the marine boundary layer was younger than that in the elevated layer. Trends in the aerosol volume distribution show consistency with multiple-site AERONET radiometric observations. The aerosol optical depths derived from aircraft measurements show a consistent bias to lower values than both the AERONET and lidar ground-based radiometric observations, differences which can be explained by local variations in the aerosol column loading and by some aircraft instrumental artefacts. Retrievals of the aerosol optical depth and fine-mode (<0.5 µm radius) fraction contribution to the optical depth using MODIS data from the Terra and Aqua satellites show a reasonable level of agreement with the AERONET and aircraft measurements. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd [source] Selective lesions of basal forebrain cholinergic neurons produce anterograde and retrograde deficits in a social transmission of food preference task in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2002Anna Vale-Martínez Abstract We examined the performance of Long-Evans rats with 192 IgG-saporin lesions of the medial septum/vertical limb of the diagonal band (MS/VDB) or nucleus basalis magnocellularis/substantia innominata (NBM/SI), which removed cholinergic projections mainly to hippocampus or neocortex, respectively. We studied the effects of these lesions on anterograde and retrograde memory for a natural form of hippocampal-dependent associative memory, the social transmission of food preference. In a study of anterograde memory, MS/VDB lesions did not affect the immediate, 24-h or 3-week retention of the task. In contrast, NBM/SI lesions severely impaired immediate and 24-h retention. In a study of retrograde memory in which rats acquired the food preference 5 days or 1 day before surgery and they were tested 10,11 days after surgery, MS/VDB-lesioned rats showed striking memory deficits for the preference acquired at a long delay (5 days) before surgery, although all lesioned rats exhibited poorer retention on both retest sessions than on their pretest performance. Subsequent testing of new anterograde learning in these rats revealed no disrupting effects of lesions on a standard two-choice test. When rats were administered a three-choice test, in which the target food was presented along with two more options, NBM/SI-lesioned rats were somewhat impaired on a 24-h retention test. These results provide evidence that NBM/SI and MS/VDB cholinergic neurons are differentially involved in a social memory task that uses olfactory cues, suggesting a role for these neurons in acquisition and consolidation/retrieval of nonspatial declarative memory. [source] SEARCHING FOR EXPLANATORY WEB PAGES USING AUTOMATIC QUERY EXPANSIONCOMPUTATIONAL INTELLIGENCE, Issue 1 2007Manabu Tauchi When one tries to use the Web as a dictionary or encyclopedia, entering some single term into a search engine, the highly ranked pages in the result can include irrelevant or useless sites. The problem is that single-term queries, if taken literally, underspecify the type of page the user wants. For such problems automatic query expansion, also known as pseudo-feedback, is often effective. In this method the top n documents returned by an initial retrieval are used to provide terms for a second retrieval. This paper contributes, first, new normalization techniques for query expansion, and second, a new way of computing the similarity between an expanded query and a document, the "local relevance density" metric, which complements the standard vector product metric. Both of these techniques are shown to be useful for single-term queries, in Japanese, in experiments done over the World Wide Web in early 2001. [source] MEMORY ORGANIZATION AS THE MISSING LINK BETWEEN CASE-BASED REASONING AND INFORMATION RETRIEVAL IN BIOMEDICINECOMPUTATIONAL INTELLIGENCE, Issue 3-4 2006Isabelle Bichindaritz Mémoire proposes a general framework for reasoning from cases in biology and medicine. Part of this project is to propose a memory organization capable of handling large cases and case bases as occur in biomedical domains. This article presents the essential principles for an efficient memory organization based on pertinent work in information retrieval (IR). IR systems have been able to scale up to terabytes of data taking advantage of large databases research to build Internet search engines. They search for pertinent documents to answer a query using term-based ranking and/or global ranking schemes. Similarly, case-based reasoning (CBR) systems search for pertinent cases using a scoring function for ranking the cases. Mémoire proposes a memory organization based on inverted indexes which may be powered by databases to search and rank efficiently through large case bases. It can be seen as a first step toward large-scale CBR systems, and in addition provides a framework for tight cooperation between CBR and IR. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||