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Results for “Large Language Models”

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PubMed1996

Identification of areas with high levels of untreated dental caries.

In order to examine the geographical variation of dental health within 10 county districts in North Wales, 3538 children were examined. The associations between three demographic indicators, based on the 1981 OPCS census, and dental health outcomes were assessed for electoral wards within the county districts. The Townsend and Jarman indices were the first two indicators employed and the third was based on a mathematical model representing the variation in the mean number of untreated decayed surfaces per person for the wards. This model was developed using the children examined in the five most westerly county districts. Using the data derived from the five most easterly county districts, the three indicators were assessed. All three showed strong correlations (r > or = 0.88) with dental health. These results indicate that measures of dental health based on large administrative units may obscure variation within them. It is concluded that geographical methods of this type may be useful for targeting dental resources at small areas with high levels of need.

Catchment Area, Health↗

PubMedDate not supplied

A FORTRAN program for multivariate survival analysis on the personal computer.

In this paper a FORTRAN program is presented for multivariate survival or life table regression analysis in a competing risks' situation. The relevant failure rate (for example, a particular disease or mortality rate) is modelled as a log-linear function of a vector of (possibly time-dependent) explanatory variables. The explanatory variables may also include the variable time itself, which is useful for parameterizing piecewise exponential time-to-failure distributions in a Gompertz-like or Weibull-like way as a more efficient alternative to Cox's proportional hazards model. Maximum likelihood estimates of the coefficients of the log-linear relationship are obtained from the iterative Newton-Raphson method. The program runs on a personal computer under DOS; running time is quite acceptable, even for large samples.

Actuarial Analysis↗

PubMed1997

Applications of abduction: hypothesis testing of neuroendocrinological qualitative compartmental models.

It is difficult to assess hypothetical models in poorly measured domains such as neuroendocrinology. Without a large library of observations to constrain inference, the execution of such incomplete models implies making assumptions. Mutually exclusive assumptions must be kept in separate worlds. We define a general abductive multiple-worlds engine that assesses such models by (i) generating the worlds and (ii) tests if these worlds contain known behaviour. World generation is constrained via the use of relevant envisionment. We describe QCM, a modeling language for compartmental models that can be processed by this inference engine. This tool has been used to find faults in theories published in international refereed journals; i.e. QCM can detect faults which are invisible to other methods. The generality and computational limits of this approach are discussed. In short, this approach is applicable to any representation that can be compiled into an and-or graph, provided the graphs are not too big or too intricate (fanout < 7).

Computer Simulation↗

PubMed1983

Digit repetition in learning-disabled children.

Investigated digit repetition performance in learning-disabled children in an effort to assess its clinical and theoretical significance. Clinically, learning-disabled children were found to demonstrate a higher than expected incidence of large verbal-performance discrepancies, although mean overall digit repetition performance did not differ appreciably from that expected on the basis of intelligence (N = 100). Children with large discrepancies did not differ from those with no such discrepancies when compared on a variety of psychometric and neurobehavioral factors. Theoretically, a hemispheric specialization model and a neuropsychological function model have been proposed to underlie performance on the two somewhat different digit repetition tasks (forward and backward repetition). Some support was found for the neuropsychological function model, with significant correlations obtained between digits forward and a measure of language function and between digits backward and a test of visual constructional ability. Stronger evidence that could have been provided by a double dissociation of correlational findings was limited by a smaller, but significant, correlation between digits forward and Bender Gestalt errors. However, the results are consistent with previous research in suggesting that digit repetition can be an avenue to the study of brain-behavior relationships.

Child↗

PubMed1998

The LabBase system for data management in large scale biology research laboratories.

MOTIVATION: The development of laboratory information management systems (LIMSs) for large scale biology research projects can be a challenging problem. Many such projects generate complex datasets via complex procedures that undergo continuous refinement. A key software challenge is to simplify the database-development task so that databases can be built and modified quickly enough to keep pace with changing project-requirements. RESULTS: LabBase extends the facilities offered by relational database systems to simplify the task of creating databases for large scale biology research projects. LabBase provides a structural object data model, similar to ACEDB, and adds to this the concepts of Materials, Steps, and States: Materials are objects representing the identifiable things that participate in a laboratory protocol; Steps are objects reporting the results of a laboratory or analytical procedure; and States are objects denoting places in a laboratory protocol. The system provides a data definition language for succinctly defining laboratory databases, and operations for conveniently storing and retrieving data in such databases. The system also provides support for workflow management. LabBase is implemented in Perl5 and provides a natural interface for laboratory application programs written in Perl. AVAILABILITY: The software is freely available. Contact the authors. CONTACT: nat@jax.org

Computational Biology↗

PubMed1983

Cluster analysis of the WAIS on brain-damaged patients.

In recognition of increased usage of cluster analytic techniques, the current study attempted to examine sampling bounds for tests and subjects on one cluster-analytic procedure. Specifically, the WAIS subtest scores from a heterogeneous group of subjects with CNS involvement were first, factor analyzed and then clustered by means of Ward's hierarchical procedure. This methodology had been previously applied to two different samples of aphasics and aphasia batteries. In both these aphasic studies, an underlying severity dimension of language dysfunction was found. In contrast, in the current study, salient feature groups were found. Moreover, these groups were distributed in a sequential or hierarchical model in terms of specific cognitive deficits. From these data, it is argued that two major parameters in determining the resulting cluster structures are the homogeneity/heterogeneity of the sample and test battery employed. Although such a statement is obvious, the theoretical ramifications are large, in that the cluster structure may be a function of test weighting or sample diversity, not the phenomenon of interest. However, the cluster structures found in the current study were consistent with historical models of cognitive dysfunction and also lend support to hierarchical models of sequential cognitive impairment. These findings are discussed in terms of their clinical and experimental ramifications with respect to grouping subjects in terms of WAIS profiles.

Adult↗

PubMed1996

The project ARIANE: conceptual queries to information databases.

As information databases we consider all the collections of data records indexed by key-words, stored and delivered by computer systems. In previous research works we demonstrated the interest to design a conceptual model, in the conceptual graphs formalism, and to implement a computational model for information retrieval in large information databases. These models are based on the UMLS knowledge sources. This paper reminds briefly these models and describes tests done in querying a patients database and a bibliographical database.

Databases, Bibliographic↗

PubMed1994

Users conceptual views on medical information databases.

As information databases we consider all the kinds of information repositories that are handled by computer systems. When querying very large information databases, the end-users are often faced with the problem to parse their questions efficiently into the query languages of the computer systems. Conceptual graphs were initially designed for natural language analysis and understanding. Due to their closeness to semantic networks, their expressiveness is powerful enough to be applied to knowledge representation and use by computer systems. This work demonstrates that conceptual graphs are a suitable means to model both the information in patient databases and the queries to these databases, and that operations on graphs can compute the pattern matching process needed to provide the answers. A prototype that exploits this model is presented. Experiments have been made with the material furnished by the Unified Medical Language System project (version 2, 1992) of the National Library of Medicine, USA.

Abstracting and Indexing↗

PubMed1994

SORTEZ: a relational translator for NCBI's ASN.1 database.

The National Center for Biotechnology Information (NCBI) has created a database collection that includes several protein and nucleic acid sequence databases, a biosequence-specific subset of MEDLINE, as well as value-added information such as links between similar sequences. Information in the NCBI database is modeled in Abstract Syntax Notation 1 (ASN.1) an Open Systems Interconnection protocol designed for the purpose of exchanging structured data between software applications rather than as a data model for database systems. While the NCBI database is distributed with an easy-to-use information retrieval system, ENTREZ, the ASN.1 data model currently lacks an ad hoc query language for general-purpose data access. For that reason, we have developed a software package, SORTEZ, that transforms the ASN.1 database (or other databases with nested data structures) to a relational data model and subsequently to a relational database management system (Sybase) where information can be accessed through the relational query language, SQL. Because the need to transform data from one data model and schema to another arises naturally in several important contexts, including efficient execution of specific applications, access to multiple databases and adaptation to database evolution this work also serves as a practical study of the issues involved in the various stages of database transformation. We show that transformation from the ASN.1 data model to a relational data model can be largely automated, but that schema transformation and data conversion require considerable domain expertise and would greatly benefit from additional support tools.

Algorithms↗

PubMed2000

Revisiting the concept of identifiable neurons.

Although eutely in nematodes was known, giant neurons in several taxa and unique motor neurons to leg muscles in decapod crustaceans, the idea that many animals have many identifiable neurons with relatively consistent dynamical properties and connections was only slowly established in the late 1960s and early 1970s. This has to be one of the important quiet revolutions in neurobiology. It stimulated a vast acquisition of specific information and led to some euphoria in the degree and pace of understanding activity of nervous systems and consequent behavior in terms of neuronal connections and properties. Some implications, problems and opportunities for new discovery are developed. The distribution of identifiable neurons among taxa and parts of the nervous system is not yet satisfactorily known. Their evolution may have been a case of several independent inventions. The degree of consistency has been quantified only in a few examples and the plasticity is little known. Identified neurons imply identifiable circuits but whether this extends to discrete systems, functionally definable, seems likely to have several answers in different animals or sites. Very limited attempts have been made to extend the concept to cases of two or ten or a hundred fully equivalent neurons, on all kinds of criteria. These attempts suggest a much smaller redundancy and vaster number of types of neurons than hitherto believed. Theory as well as empirical information has not yet interpreted the range of systems from those with small sets of relatively reliable neurons to those with large numbers of parallel, partially redundant units. The now classical notion of local circuits has to be extended to take account of and find roles for the plethora of integrative variables, of evidence for neural processing independent of spikes and classical synapses, of spatial configurations of terminal arbors and dendritic geometry, of modulators and transmitters, degrees of rhythmicity (regularity varying several orders of magnitude), and of synchrony. Adequate language and models need to go beyond 'circuits' in any engineering sense. Identifiable neurons can contribute to a broad spectrum of issues in neurobiology.

Animals↗

PubMed2000

Antibiotic prophylaxis for surgery for proximal femoral and other closed long bone fractures.

BACKGROUND: Antibiotic prophylaxis has been established policy for major surgical operations for many years. In fracture fixation, the effectiveness, and the duration of administration, have been a matter of debate. OBJECTIVES: To assess the effects of the prophylactic administration of antibiotics in patients undergoing surgical management of hip or other long bone fractures. SEARCH STRATEGY: We searched MEDLINE, EMBASE, Current Contents, Dissertation Abstracts, and Index to UK Theses, and bibliographies of identified articles. Trials were also obtained from the Cochrane Musculoskeletal Injuries Group trials register. Date of the most recent search: end of 1997. SELECTION CRITERIA PARTICIPANTS: Any patients with a hip or other closed long bone fracture undergoing surgery for internal fixation or replacement arthroplasty. INTERVENTIONS: Any regimen of systemic antibiotic prophylaxis administered at the time of surgery. OUTCOME MEASURES: Wound infection (deep and superficial), urinary tract infection, respiratory tract infection, adverse effects of prophylaxis, economic evaluations. DATA COLLECTION AND ANALYSIS: Both reviewers independently selected trials for inclusion, and assessed methodological quality and extracted data. Where possible, data were pooled and Peto odds ratios and absolute risk reductions, each with 95% confidence intervals, calculated. MAIN RESULTS: Twenty one randomised trials of only poor or moderate quality were included. The comparisons tested fell within six comparison groups, principally multiple dose or a single dose of antibiotic versus a placebo or no treatment. Antibiotic prophylaxis reduces wound, urinary and respiratory tract infections in patients undergoing surgery for closed fracture fixation. Economic modelling has indicated that this is a cost-effective intervention. There are limited data for the incidence of adverse effects, but as expected they appear to be more common in those receiving antibiotics. REVIEWER'S CONCLUSIONS: Antibiotic prophylaxis should be offered to those undergoing surgery for closed fracture fixation. On ethical grounds, further placebo controlled randomised trials of the effectiveness of antibiotic prophylaxis in closed fracture surgery are unlikely to be justified. Trials addressing the cost-effectiveness of different effective antibiotic regimens would need to be very large and may not be feasible.

Antibiotic Prophylaxis↗

PubMed1996

Encoding words and pictures: a positron emission tomography study.

Subjects viewed words, pictures, crosshairs, or a large X flanked by two smaller xs on either side while their brain activity was monitored using positron emission tomography (PET). When activation from the pictures, crosshairs, or Xs condition was subtracted from activation in the words condition, the left angular gyrus and Broca's area were found to be activated. In the comparison of words and pictures, additional language areas were activated. These results provide support for the classical neurological model of reading. The results also suggest that a "word form area" is near the margin of the left angular gyrus.

Adolescent↗

PubMed1998

Web-based segmentation and display of three-dimensional radiologic image data.

In many clinical circumstances, viewing sequential radiological image data as three-dimensional models is proving beneficial. However, designing customized computer-generated radiological models is beyond the scope of most physicians, due to specialized hardware and software requirements. We have created a simple method for Internet users to remotely construct and locally display three-dimensional radiological models using only a standard web browser. Rapid model construction is achieved by distributing the hardware intensive steps to a remote server. Once created, the model is automatically displayed on the requesting browser and is accessible to multiple geographically distributed users. Implementation of our server software on large scale systems could be of great service to the worldwide medical community.

Algorithms↗

PubMedDate not supplied

Hyperad: augmenting and visualizing free text radiology reports.

Hyperad is an automated computer system designed to extract key concepts from thoracic radiology reports and give physicians access to a large database containing the reports and key concepts. The concepts are extracted from textual documents with natural language processing techniques, then stored with the original documents in the database, which can be queried in terms of findings or associated attributes from an intuitive and easily accessible interface. The extracted concepts are represented both textually in a coded hypertext format and graphically on a coronal cross-sectional anatomy atlas, an idealized graphical model of human anatomy. To facilitate implementation, the communication protocols and standards of the World Wide Web (Web) were adopted. The reports and associated forms are encoded in standard hypertext markup language, which makes it possible to use hypermedia links to navigate the Hyperad database with any graphical Web browser. In the future, Hyperad may prove useful for other applications.

Computer Systems↗

PubMed2003

Importing statistical measures into Artemis enhances gene identification in the Leishmania genome project.

BACKGROUND: Seattle Biomedical Research Institute (SBRI) as part of the Leishmania Genome Network (LGN) is sequencing chromosomes of the trypanosomatid protozoan species Leishmania major. At SBRI, chromosomal sequence is annotated using a combination of trained and untrained non-consensus gene-prediction algorithms with ARTEMIS, an annotation platform with rich and user-friendly interfaces. RESULTS: Here we describe a methodology used to import results from three different protein-coding gene-prediction algorithms (GLIMMER, TESTCODE and GENESCAN) into the ARTEMIS sequence viewer and annotation tool. Comparison of these methods, along with the CODONUSAGE algorithm built into ARTEMIS, shows the importance of combining methods to more accurately annotate the L. major genomic sequence. CONCLUSION: An improvised and powerful tool for gene prediction has been developed by importing data from widely-used algorithms into an existing annotation platform. This approach is especially fruitful in the Leishmania genome project where there is large proportion of novel genes requiring manual annotation.

Algorithms↗

PubMed1999

Hierarchical subcomponents of the Big Five personality factors: a cross-language replication.

An ideal structural representation of personality attributes would include more than just broad-bandwidth factors. Specific subcomponents help define broad factors while enhancing the fidelity of the representation. There has been no consensus with regard to the necessary specific subcomponents of the Big Five. This problem was addressed by analyzing 2 representative lexical data sets, one involving English adjectives and the other involving German adjectives. Large samples (Ns of 636 and 775) were used in classifying a selection of 500 adjectives in each language by Big Five domains, and within each domain and language, the terms were factor analyzed with promax rotation. Ratings by 22 bilinguals of correspondence between the adjectives in English and German factors indicated 18 distinct content themes common to personality description in the 2 languages. The 18 subcomponents delineate necessary features of a more finely faceted measurement model for the lexical Big Five factors.

Adolescent↗

PubMed1985

The community residential treatment service: developing a continuum of prosthetic environments for the chronically disabled.

Among the many issues regarding the care of chronic mental patients, none is more pressing than the need for administrative and clinical models designed to organize and systematize the efforts of diverse community service providers. This paper describes the functioning of the Community Residential Treatment Service of the South Beach Psychiatric Center, a large-scale project of a state facility created to respond to this tissue. By blending sophisticated clinical and administrative technology, programs operated by the state, voluntary, and proprietary health care sectors have been integrated to form a balanced service delivery system. This system provides a broad continuum of inpatient and outpatient residential settings developed in accordance with social learning principles. The components of the system, with the Community Residential Treatment Service as the major integrative force, are linked together by detailed contracts as well as common behavioral clinical and behavioral administrative language. The treatment successes f this system have been significant enough to suggest that a positive synergistic effect is generated by this programming combination.

Community Mental Health Services↗

PubMed1989

Diagnostic labels applied to model case histories of chronic airflow obstruction. Responses to a questionnaire in 11 North American and Western European countries.

In Canada, USA and 9 Western European Countries, 121 respiratory physicians responded to an English language questionnaire asking them to state how they would investigate, treat and label four model patients, chosen to represent well-recognized patterns of clinical features of chronic airflow obstruction. Selection of further investigations appeared to be determined more by the probable diagnostic label than by the need to define selected characteristics in the whole range of such patients. Differences in recommended treatment between countries were less than others have reported for the treatment of asthma. Analysis of the diagnostic labels showed: the classic terms asthma, chronic bronchitis, emphysema still predominated in clinical practice and were considered to be better defined entities than any of the many terms introduced to describe chronic airflow obstruction in the last 30 yrs; the term chronic bronchitis was a source of confusion unless qualified to indicate presence or absence of obstruction; the use of combination terms such as chronic asthmatic bronchitis and chronic obstructive bronchitis showed large differences between countries; there were few differences related to national language. The implications of these findings are discussed.

Aged↗