Augenlicht, LH, Wadler, S, Corner, G, Richards, C, Ryan, L, Multani, AS, Pathak, S, Benson, A, Haller, D & Heerdt, BG 1997, 'Low-level c-myc amplification in human colonic carcinoma cell lines and tumors: a frequent, p53-independent mutation associated with improved outcome in a randomized multi-institutional trial.', Cancer Res, vol. 57, no. 9, pp. 1769-1775.
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Human colonic cancer is associated with multiple genetic deletions, mutations, and alterations in gene expression; in contrast, gene amplification has not been recognized as a prominent characteristic of human colonic tumors. Although the c-myc gene is overexpressed in approximately 70% of human colonic cancers, previous studies have not detected frequent gene amplification or rearrangement of c-myc in these tumors, although such amplification has been reported in chemically induced rodent colon cancer and quantitative analysis of gene copy number has shown the gene to be amplified at a low level in mucinous and poorly differentiated human colon carcinomas. Using rigorously controlled blot methodology, we have established that the c-myc gene, located at 8q21, exhibited amplification of 87% to 35-fold in 7 of 10 human colonic carcinoma cell lines. This was highly significant even at a low level of amplification in HT29 cells (P < 0.0001). Cytogenetic analysis by G-banding did not detect aneuploidy involving chromsome 8q, suggesting that the amplification for the c-myc gene on 8q was relatively specific, and this was consistent with a lack of amplification detected for the c-mos gene on 8q24, which was assayed similarly. The same methodology then revealed amplification of c-myc from 1.5-fold to 5-fold in 32% of tumors from 149 patients entered into a multi-institutional Phase III study of adjuvant therapy for colon cancer. c-myc status was not related to time to recurrence or death, but low levels of c-myc amplification identified a subset of patients who showed a statistically significant increase in disease-free survival, and a corresponding trend to longer overall survival, in response to adjuvant therapy with 5-fluorouracil plus levamisole. Presence of c-myc amplification was not related to incidence of p53 mutations.
Baird, SJS, Catalano, PJ, Ryan, LM & Evans, JS 1997, 'Evaluation of Effect Profiles: Functional Observational Battery Outcomes', Toxicological Sciences, vol. 40, no. 1, pp. 37-51.
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The Functional Observational Battery (FOB) is a neurotoxicity screening assay composed of 25-30 descriptive, scalar, binary, and continuous endpoints. These outcomes have been grouped into six biologically logical domains as a means to interpret the neuroactive properties of tested chemicals (V.C. Moser, 1992, J. Am. Cell. Toxicot. 10(6), 661-669). However, no data-based exploration of these functional domains has been done. We investigated the degree to which experimental data correspond to the domain groupings by examining severity scores from 10 chemicals tested using a standardized protocol for acute exposure (V.C. Moser et al., 1995, J. Toxicol. Environ. Health 45, 173-210) and identifying endpoint groupings (factors) that best describe the interrelationships in the data, allowing a statistical assessment of whether the FOB endpoints break into domains. We also used a standard measure of bivariate association to confirm the results of the factor analysis. Our results show that while there are clear relationships among variables that compose some domains, there is often substantial correlation among endpoints in different domains. In addition, we investigated a related issue concerning the relative power of the chosen endpoint groupings for identifying significant domain effects. Results from a randomization analysis of the 10 chemicals suggest that the neurophysiologic domain structuring may provide some degree of statistical efficiency for identifying effects.
Baird, SJS, Catalano, PJ, Ryan, LM & Evans, JS 1997, 'Evaluation of effect profiles: Functional observational battery outcomes', FUNDAMENTAL AND APPLIED TOXICOLOGY, vol. 40, no. 1, pp. 37-51.
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The Functional Observational Battery (FOB) is a neurotoxicity screening assay composed of 25-30 descriptive, scalar, binary, and continuous endpoints. These outcomes have been grouped into six biologically logical domains as a means to interpret the neur
Beck, DA, Brady, BHG & Grant, DR 1997, 'Induced stress and microseismicity in the 3000 Orebody, Mount Isa', Geotechnical and Geological Engineering, vol. 15, no. 3, pp. 221-233.
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The 3000 Orebody is one of two orebodies in the Deep Copper Mine at Mount Isa, Australia. Owing to concerns about potential shaft pillar instabilities, an integrated seismic system was introduced to monitor seismic activity associated with pillar and country rock deformation. Coupled with numerical modelling of the stress regime, the system may assist in the characterization of rock mass damage resulting from mining, and perhaps the identification of near- and far-field geological structures that affect slope performance. A study was undertaken to quantify the seismicity and to determine potential applications of the seismic technology. The relation between geological structure and seismicity is strong, suggesting good prospects for the use of the system in the ground-control activities noted above. The induction of seismicity, which involves small magnitude events, is associated with reduction of normal stress on planes of weakness, suggesting that stress path may be an important factor in the level of seismicity observed in hard rock mines.
Chow, TWS & Li, J-Y 1997, 'Higher-order Petri net models based on artificial neural networks', Artificial Intelligence, vol. 92, no. 1-2, pp. 289-300.
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In this paper, the properties of higher-order neural networks are exploited in a new class of Petri nets, called higher-order Petri nets (HOPN). Using the similarities between neural networks and Petri nets this paper demonstrates how the McCullock-Pitts
Clark, DE & Ryan, LM 1997, 'Modeling injury outcomes using time-to-event methods', JOURNAL OF TRAUMA-INJURY INFECTION AND CRITICAL CARE, vol. 42, no. 6, pp. 1129-1134.
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Background: Mortality is an important measurement of injury outcomes, but measurements reflecting disability or cost are also important. Hospital length of stay (LOS) has been used as an outcome variable, but reduced LOS could be achieved either by improved care or by increased mortality. A solution to this statistical problem of 'competing risks' would enable injury outcomes based on LOS to be modeled using time-to-event methods. Methods: Time-to-event methodology was applied to 2,106 cases with complete data from the 1991-1994 registry of a regional trauma center. LOS was used as the outcome variable, modified by assigning an arbitrarily long LOS to any fatal case. A combination of proportional hazards and logistic regression models was used to explore the effects of potential predictive variables, including Trauma Score (TS), Injury Severity Score (ISS), components of TS or ISS, age, sex, alcohol use, and whether a patient was transferred. Results: The 'TRISS' combination of TS, ISS, and age previously shown to predict mortality also predicted 'modified LOS' (Wald p value less than 0.001 for each variable). Models using only age and certain components of ISS or TS fit our data even better, with fewer parameters. Other variables were not predictive. Modified Kaplan-Meier plots provided easily interpreted graphical results, combining both mortality and LOS information. Conclusions: With a simple modification to allow for competing risks, time-to-event methods enable more informative modeling of injury outcomes than binary (lived/died) methods alone. Such models may be useful for describing and comparing groups of hospitalized trauma patients.
Cucchiara, R, Di Stefano, L, Piccardi, M & Cinotti, TS 1997, 'The GIOTTO System: a Parallel Computer for Image Processing', Real-Time Imaging, vol. 3, no. 5, pp. 343-353.
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This paper presents the GIOTTO system, a parallel computer based on a scalable single instruction, multiple data (SIMD) array of processors specially conceived for image processing, The system is characterized by a reduced-size array and a novel organiza
Geys, H, Molenberghs, G & Ryan, LM 1997, 'Pseudo-likelihood inference for clustered binary data', COMMUNICATIONS IN STATISTICS-THEORY AND METHODS, vol. 26, no. 11, pp. 2743-2767.
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Molenberghs and Ryan (1996) proposed a likelihood-based model for clustered. binary data, based on a multivariate exponential family model (Cox, 1972). The model benefits from the elegance and simplicity of exponential family theory and is flexible in terms of allowing response rates to depend on cluster size. A main problem however, particularly with large clusters is the evaluation of the normalizing constant. In this paper, pseudo-likelihood is explored as an alternative mode of inference. The pseudo-likelihood equations are derived, the model is applied to data from a developmental toxicity study, and an asymptotic and small sample relative efficiency study is performed.
Jian Zhang, Frater, MR, Arnold, JF & Percival, TM 1997, 'MPEG 2 video services for wireless ATM networks', IEEE Journal on Selected Areas in Communications, vol. 15, no. 1, pp. 119-128.
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Audio-visual and other multimedia services are seen as an important source of traffic for future telecommunications networks, including wireless networks. In this paper, we examine the impact of the properties of a 50 Mb/s asynchronous transfer mode (ATM
Legler, JM & Ryan, LM 1997, 'Latent Variable Models for Teratogenesis Using Multiple Binary Outcomes', Journal of the American Statistical Association, vol. 92, no. 437, pp. 13-13.
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Legler, JM & Ryan, LM 1997, 'Latent variable models for teratogenesis using multiple binary outcomes', JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION, vol. 92, no. 437, pp. 13-20.
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Multiple outcomes are commonly measured in:the study of birth defects. The reason is that most teratogens do not cause a single, uniquely defined defect, but rather result in a range of effects, including major malformations, minor anomalies, and deficiencies in birth weight, length and head circumference. The spectrum of effects associated with a particular teratogen is sometimes described as a ''syndrome.'' In this article we develop a latent variable model to characterize exposure effects on multiple binary outcomes. Not only does the method allow comparisons of control and exposed infants with respect to multiple outcomes, but it also provides a measure of the ''severity'' of each child's condition. Data from a study of the teratogenic effects of anticonvulsants illustrate our results.
Luo, X, Zhang, C & Cai, J 1997, 'The weighting issue in fuzzy logic', Informatica (Ljubljana), vol. 21, no. 2, pp. 255-262.
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The objective of this paper is to establish a class of models for solving the weight problem in fuzzy logic. First, some constraints that weighted fuzzy logic should satisfy are given based on Triangular norms and conorms. Then, based on these constraints, a class of models (referred to as relative weighted models) are established for handling weights in fuzzy logic. These models are novel in three aspects: (1) they include non-weighted models as their special cases, (2) the weighted conjunction and weighted disjunction can be distinguished from each other, and (3) the information from all sub-propositions can be sufficiently considered. In addition, this paper proposes principles for selecting proper weighted models.
Piccardi, M, Cucchiara, R, Bariani, M & Mello, P 1997, 'Exploiting symbolic learning in visual inspection', Advances In Intelligent Data Analysis, vol. 1280, pp. 223-234.
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The paper describes the use of data analysis techniques in the computer-vision inspection of industrial workpieces. Computer-vision inspection aims at accomplishing quality verification of fabricated parts by means of automated visual procedures. Gatheri
Ryan, LM 1997, 'Adjuvant chemotherapy for localised resectable soft-tissue sarcoma of adults: meta-analysis of individual data', The Lancet, vol. 350, no. 9092, pp. 1647-1654.
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BACKGROUND: Individually, randomised trials have not shown conclusively whether adjuvant chemotherapy benefits adult patients with localised resectable soft-tissue sarcoma. METHODS: A quantitative meta-analysis of updated data from individual patients from all available randomised trials was carried out to assess whether adjuvant chemotherapy improves overall survival, recurrence-free survival, and local and distant recurrence-free intervals (RFI) and whether chemotherapy is differentially effective in patients defined by age, sex, disease status at randomisation, disease site, histology, grade, tumour size, extent of resection, and use of radiotherapy. FINDINGS: 1568 patients from 14 trials of doxorubicin-based adjuvant chemotherapy were included (median follow-up 9.4 years). Hazard ratios of 0.73 (95% CI 0.56-0.94, p = 0.016) for local RFI, 0.70 (0.57-0.85, p = 0.0003) for distant RFI, and 0.75 (0.64-0.87, p = 0.0001) for overall recurrence-free survival, correspond to absolute benefits from adjuvant chemotherapy of 6% (95% CI 1-10), 10% (5-15), and 10% (5-15), respectively, at 10 years. For overall survival the hazard ratio of 0.89 (0.76-1.03) was not significant (p = 0.12), but represents an absolute benefit of 4% (1-9) at 10 years. These results were not affected by prespecified changes in the groups of patients analysed. There was no consistent evidence that the relative effect of adjuvant chemotherapy differed for any subgroup of patients for any endpoint. However, the best evidence of an effect of adjuvant chemotherapy for survival was seen in patients with sarcomas of the extremities. INTERPRETATION: The meta-analysis provides evidence that adjuvant doxorubicin-based chemotherapy significantly improves the time to local and distant recurrence and overall recurrence-free survival. There is a trend towards improved overall survival.
Sammel, MD, Ryan, LM & Legler, JM 1997, 'Latent variable models for mixed discrete and continuous outcomes', JOURNAL OF THE ROYAL STATISTICAL SOCIETY SERIES B-METHODOLOGICAL, vol. 59, no. 3, pp. 667-678.
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We propose a latent variable model for mixed discrete and continuous outcomes. The model accommodates any mixture of outcomes from an exponential family and allows for arbitrary covariate effects, as well as direct modelling of covariates on the latent variable. An EM algorithm is proposed for parameter estimation and estimates of the latent variables are produced as a by-product of the analysis. A generalized likelihood ratio test can be used to test the significance of covariates affecting the latent outcomes. This method is applied to birth defects data, where the outcomes of interest are continuous measures of size and binary indicators of minor physical anomalies. Infants who were exposed in utero to anticonvulsant medications are compared with controls.
Stark, PC, Ryan, LM, McDonald, JL & Burge, HA 1997, 'Using meteorologic data to predict daily ragweed pollen levels', Aerobiologia, vol. 13, no. 3, pp. 177-184.
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Pollen-related allergy is a common disease resulting in symptoms of hay fever and asthma. Control of symptoms depends (generally) on avoidance and pharmacological treatment. Both of these approaches could benefit from accurate predictions of pollen levels for future days. We have constructed a model that uses meteorological data to predict ragweed pollen levels based on air samples collected daily in Kalamazoo, MI from 1991 to 1994. Ragweed pollen counts were converted to pollen grains/m3 of air (24-h average). We used Poisson regression, which appropriately handles the heterogenous variance associated with pollen data. Using standard statistical model selection procedures, combined with biological considerations, we selected rainfall, wind speed, temperature, and the time measured from the start of the season as the most significant variables. Using our model, we propose a method that uses the weather forecast for the following day to predict the ragweed pollen level. This approach differs from most previous attempts because it uses Poisson regression and because this model needs to be fit iteratively each day. By updating the coefficients of the model based on the information to date, this method allows the fundamental shape of the pollen distribution curve to change from year to year. Application to the Kalamazoo data suggests that the method has good sensitivity and specificity for predicting high pollen days.
Wang, XB, Ding, H, Ryan, L & Xu, XP 1997, 'Association between air pollution and low birth weight: A community-based study', ENVIRONMENTAL HEALTH PERSPECTIVES, vol. 105, no. 5, pp. 514-520.
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The relationship between maternal exposure to air pollution during periods of pregnancy (entire and specific periods) and birth weight was investigated in a well-defined cohort. Between 1988 and 1991, all pregnant women living in four residential areas of Beijing were registered and followed from early pregnancy until delivery. Information on individual mothers and infants was collected. Daily air pollution data were obtained independently. The sample for analysis included 74,671 first-parity live births were gestational age 37-44 weeks. Multiple linear regression and logistic regression were used to estimate the effects of air pollution on birth weight and low birth weight (< 2,500 g), adjusting for gestational age, residence, year of birth, maternal age, and infant gender. There was a significant exposure-response relationship between maternal exposures to sulfur dioxide (SO2) and total suspended particles (TSP) during the third trimester of pregnancy and infant birth weight. The adjusted odds ratio for low birth weight was 1.11 (95% CI, 1.06-1.16) for each 100 micrograms/m3 increase in SO2 and 1.10 (95% CI, 1.05-1.14) for each 100 micrograms/m3 increase in TSP. The estimated reduction in birth weight was 7.3 g and 6.9 g for each 100 micrograms/m3 increase in SO2 and in TSP, respectively. The birth weight distribution of the high-exposure group was more skewed toward the left tail (i.e., with higher proportion of births < 2,500 g) than that of the low-exposure group. Although the effects of other unmeasured risk factors cannot be excluded with certainty, our data suggests that TSP and SO2, or a more complex pollution mixture associated with these pollutants, contribute to an excess risk of low birth weight in the Beijing population.
Weller, EA, Ryan, LP, Spiegelman, D & Smith, T 1997, 'Statistical issues in assessing human population exposures', CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS, vol. 37, no. 1, pp. 189-195.
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Relating an exposure level to a particular outcome in occupational and environmental epidemiology studies may be challenging. In these studies, researchers are interested in the health effects form exposure. Two factors that complicate this process are the measurement error that is usually present in exposure assessment and the complex nature of the exposure-dose relationship. Statistical aspect of the measurement error problem has been the focus of many researchers in the past few years. However, less attention has been given to the second issue of incorporating the relationship between exposure and dose and directly modeling the dose-response relationship, when this of primary scientific interest. For complex exposure-dose relationships, a direct application of statistical methods to relate exposure to the health outcome may lead to bias and loss of efficiency in estimates of the dose- response relationship. In this paper, we present some of the statistical issues that arise using a study of the heath effects are welding fumes as an illustration.
Chengqi Zhang & Shichao Zhang 1970, 'A time framework for temporal databases', TENCON '97 Brisbane - Australia. Proceedings of IEEE TENCON '97. IEEE Region 10 Annual Conference. Speech and Image Technologies for Computing and Telecommunications (Cat. No.97CH36162), TENCON '97 Brisbane - Australia IEEE TENCON '97 IEEE Region 10 Annual Conference. Speech and Image Technologies for Computing and Telecommunications, IEEE, pp. 215-218.
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There are two different strategies for incorporating a temporal dimension into the relational models in the literature. One is the first-normal-form(1NF) model; and the other is the non-first-normal-form(N1NF) model. Both of them are required to support an ability of handling data with temporal element (or temporal set, or gap-interval). In order to support these temporal operations for temporal databases, some basic concepts and a calculus form between temporal elements are established in this paper.
Cucchiara, R, Callipo, A & Piccardi, M 1970, 'Block processing on multiprocessor DSPs for multimedia applications', Proceedings of First Signal Processing Society Workshop on Multimedia Signal Processing, First Signal Processing Society Workshop on Multimedia Signal Processing, IEEE, PRINCETON, NJ, pp. 439-444.
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Cucchiara, R, Piccardi, M, Bariani, M & Mello, P 1970, 'Learning for feature selection and shape detection', Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Berlin Heidelberg, pp. 535-542.
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© Springer-Verlag Berlin Heidelberg 1997. The paper proposes a general framework for shape detection based on supervised symbolic learning. Differently from other visual systems exploiting machine learning, the proposed architecture does not follow the object segmentation - feature extraction and (learning based) classification approach. Instead, an initial data-driven processing selects points of interest in the scene by means of complex features which hypothesize the presence of the target shape; hypotheses are validated by a classifier defined by a machine learning algorithm. Learning is exploited not only for defining the model, i.e. the description of the target for the classifier, but also for defining the description language, i.e. the feature set useful in generating reliable object hypotheses. The proposed architecture of visual system has been implemented for an industrial application of unstructured shape detection: examples and results are reported in the paper.
Jian Zhang, Arnold, JF, Frater, MR & Pickering, MR 1970, 'Video error concealment using decoder motion vector estimation', TENCON '97 Brisbane - Australia. Proceedings of IEEE TENCON '97. IEEE Region 10 Annual Conference. Speech and Image Technologies for Computing and Telecommunications (Cat. No.97CH36162), TENCON '97 Brisbane - Australia IEEE TENCON '97 IEEE Region 10 Annual Conference. Speech and Image Technologies for Computing and Telecommunications, IEEE, QUEENSLAND UNIV TECHNOL, BRISBANE, AUSTRALIA, pp. 777-780.
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Zhang, S & Zhang, C 1970, 'Query languages for 1NF temporal databases', IEEE Region 10 Annual International Conference, Proceedings/TENCON, IEEE Region 10 Annual Conference on Speech and Image Technologies for Computing and Telecommunications (IEEE TENCON 97), IEEE, QUEENSLAND UNIV TECHNOL, BRISBANE, AUSTRALIA, pp. 211-214.
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There are two factors that should be considered in defining or designing a temporal database. One is that the uncertain time `NOW' should be noticed in the relational algebraic operators extended for incorporating a temporal dimension. The other is that the temporal-normal-form is closure under operators extended. In this paper, we establish gap-interval-based 1NF temporal tuple calculus language and the corresponding temporal relational algebra. The query languages are given some considerations to above two factors.
