Showing papers by "City University London published in 1990"

Recollective experience in word and nonword recognition.

Abstract: The functional relationship between memory and consciousness was investigated in two experiments in which subjects indicated when recognizing an item whether they could consciously recollect its prior occurrence in the study list or recognized it on some other basis, in the absence of conscious recollection. Low-frequency words, relative to high-frequency words, enhanced recognition accompanied by conscious recollection but did not influence recognition in the absence of conscious recollection. By contrast, nonwords compared with words enhanced recognition in the absence of conscious recollection and reduced recognition accompanied by conscious recollection. A third experiment showed that confidence judgments in recognizing nonword targets corresponded with recognition performance, not with recollective experience. These measures of conscious awareness therefore tap qualitatively different components of memory, not some unitary dimension such as “trace strength.” The findings are interpreted as providing further support for the distinction between episodic memory and other memory systems, and also as providing more qualified support for theories that assume that recognition memory entails two components, one of which may also give rise to priming effects in implicit memory.

Attention and recollective experience in recognition memory.

Abstract: The functional relation between recognition memory and conscious awareness was assessed in an experiment in which undivided attention at study was compared with two divided attention conditions, one more demanding than the other. When recognizing a word from the study list, subjects indicated whether they could consciously recollect its prior occurrence or recognized it on some other basis, in the absence of conscious recollection. Divided attention at study progressively impaired word recognition accompanied by conscious recollection. Recognition in the absence of conscious recollection was not affected by divided attention. These findings are interpreted as providing further support for the idea that recognition memory entails two distinct components, one based on associative and contextual information, the other based on a "traceless" awareness of familiarity.

Accurate fault location technique for power transmission lines

Abstract: The authors describe a very accurate fault location technique which uses post-fault voltage and current derived at both line ends. Fault location is independent of fault resistance and the method does not require any knowledge of source impedance. It maintains high accuracy for untransposed lines and no fault type identification is required. The authors present the theory of the technique and the results of simulation studies to determine its performance.< >

Recalibrating software reliability models

Abstract: There is no universally applicable software reliability growth model which can be trusted to give accurate predictions of reliability in all circumstances. A technique of analyzing predictive accuracy called the u-plot allows a user to estimate the relationship between the predicted reliability and the true reliability. It is shown how this can be used to improve reliability predictions in a very general way by a process of recalibration. Simulation results show that the technique gives improved reliability predictions in a large proportion of cases. However, a user does not need to trust the efficacy of recalibration, since the new reliability estimates produced by the technique are truly predictive and their accuracy in a particular application can be judged using the earlier methods. The generality of this approach suggests its use whenever a software reliability model is used. Indeed, although this work arose from the need to address the poor performance of software reliability models, it is likely to have applicability in other areas such as reliability growth modeling for hardware. >

The use of picture/word matching tasks to assist word retrieval in aphasic patients

Abstract: Three single case studies and a small group study were undertaken to examine the effects of using picture to word matching tasks as a therapeutic technique in aiding word retrieval in aphasic patie...

The GRIMS. A psychometric instrument for the assessment of marital discord

Abstract: Research in marital therapy has been disadvantaged by the lack of a good, short and recent psychometric questionnaire to objectively assess the state of a marriage for research, demographic and clinical purposes. The Golombok Rust Inventory of Marital State (GRIMS) is a companion questionnaire to the Golombok Rust Inventory of Sexual Satisfaction (GRISS), and concentrates on aspects other than the sexual in a dyadic relationship between two adults living together. It is a 28 item psychometrically constructed inventory designed to produce a single scale along which changes in a marriage may develop as marital therapy progresses. It has been shown to be valid for this purpose, and to have a good reliability.

Speech therapy and Parkinson's disease: a review and further data.

Abstract: A review is undertaken of recent experimental studies of the effects of speech therapy offered to patients with Parkinson's disease. In contrast to earlier opinions based upon clinical impressions, the results of these studies indicate that the immediate gains from therapy measured within the clinical setting are readily detected, that these are perceived by patient's relatives and that there is reasonable evidence that benefits persist for some period after treatment. A further study is reported which tests the effects of a less intensive treatment regimen. This also gave positive results. Although questions remain regarding the most efficient form of treatment and the extent of its benefits outside the clinic, the existing results warrant greater optimism about the benefits of speech therapy offered to patients with Parkinson's disease.

The duality of informetric systems with applications to the empirical laws

Abstract: Informetric systems are formalized in order to make them suitable for mathematical dual analysis: the duality of sources vs. items (sources being the objects that produce while the items are the objects that are produced). The special place of empirical laws, such as those of Bradford, Leimkuhler. Mandelbrot and Lotka, in this framework is indicated.The paper closes with a section on some of the fundamental problems in informetric systems: higher dimensions, time de pendence and fractal aspects.

Idiometric assay: noncompetitive immunoassay for small molecules typified by the measurement of estradiol in serum.

Abstract: We report here a novel noncompetitive immunoassay applicable to the measurement of small-molecular-mass compounds and typified by the direct measurement of estradiol in serum. Two types of anti-idiotypic antibody recognize different epitopes within the hypervariable region of the specific primary antibody (e.g., anti-estradiol). The first anti-idiotype (betatype) recognizes an epitope at the unoccupied binding site, which is masked in the presence of the analyte (e.g., estradiol). The second (alphatype) recognizes an epitope close to the binding site and is unaffected by the presence or absence of the analyte, but is sterically hindered from binding to the primary antibody in the presence of the betatype. The use of these matched antibodies (primary antibody, alphatype, and betatype) has enabled the development of a method for determining antibody occupancy that is not based on a conventional two-site assay. An excess amount of purified monoclonal antibody against estradiol is immobilized onto the walls of microtiter wells. After the capture of analyte, the unoccupied antibody sites are blocked by the addition of an excess amount of betatype. Subsequently, analyte occupancy is determined by the addition of excess europium-labeled alphatype, incubation, washing, and time-resolved fluorometry. The method demonstrates good sensitivity, precision, and comparability with alternative competitive immunoassays.

A quantitative approach to measuring the social effects of epilepsy.

Abstract: This paper describes the construction of a postal questionnaire which has been used to investigate the social affects of epilepsy on a wide range of patients. The social profile was designed following extensive patient interviews at the National Hospital for Nervous Diseases and the Chalfont Centre for Epilepsy. The initial research revealed 21 areas of concern for the individual with epilepsy, which are described. Reliability was assessed on a test/retest procedure. Validity was tested via a criterion-related study based on the behaviour of the subject. Following reliability and validity studies 14 areas were eventually selected for the final questionnaire. Instruments have been adapted for both children and adults.

Employment and drinking in early adulthood: a longitudinal perspective.

Abstract: The relationship between drinking and employment was examined in a large, national representative longitudinal sample of young adults in Britain. Teenage drinking did not emerge as a strong influence upon subsequent employment experience: few associations were significant for either sex. However, early employment experiences did appear to be relevant to drinking in young adults, since unemployment of six months or more in total was significantly associated with heavier drinking in men (odds ratio = 1.38, CI 1.14-1.64). Respondents ratings of overall job satisfaction were not generally associated with either previous drinking or with that in early adulthood.

Model-based vision for automatic alarm interpretation

Abstract: In a previous paper T.J. Ellis et al. (1989) described the development of a knowledge-based vision recognition system for automating the interpretation of alarm events resulting from a perimeter intrusion detection system (PIDS). Measurements extracted over a sequence of digitized images are analyzed to identify the cause of alarm. Models are maintained for both alarm causes and the scene and the measurements are matched with the models to derive an appropriate classification of the event. The authors record progress on the further development of the system and present the results of applying it to a number of real alarms. The system is shown to behave robustly, correctly classifying genuine alarm events (i.e., human intruders) and providing statistics of false alarm events. >

The use of fluorescent probes in immunochemistry.

Abstract: The limitations and advantages of particular dyes for labelling proteins and other biological materials are discussed. Methods available for conjugating dyes to proteins are outlined. Following a discussion of double labelling methods the use of photoactivatable fluorochromes and time resolved fluorescence methodologies are outlined. The reasons for the photoinstability of some fluorochromes are discussed and methods for overcoming the problem are described.

Health in Childhood and Social Inequalities in Health in Young Adults

Abstract: The role of childhood and adolescent health and development has been assessed as a potential explanation for later social class inequalities in health using longitudinal data from the 1958 cohort study. In early adulthood, general health (as self‐rated by respondents) and emotional health (as measured by the malaise inventory) were generally poorer in lower social classes. Adjustment for a wide range of childhood health characteristics did not reduce class differences in health evident in early adulthood and were therefore considered to be relatively unimportant influences. Some reduction in the class differences did occur, however, when allowance was made for ill‐health in adolescence. For example, odds of ‘poor’ or ‘fair’ rating of health at age 23 years in classes IV and V relative to classes I and II decreased from 2.52 to 2.26 in men and 3.39 to 3.08 in women after adjusting for school absence through ill‐health at age 16. Adolescent health may contribute to class inequalities in health but preliminary consideration of other potential influences (socioeconomic circumstances and health‐related behaviour) suggests that other factors may be relatively more important.

On-line steady-state optimisation of nonlinear constrained processes with slow dynamics

Abstract: A scheme for on-line optimisation of constrained nonlinear processes with slow dynamics is suggested and applied to a continuous reactor process. A two-model adaptive mechanism, dynamic and steady state, is used in the scheme. The dynamic model is used to approximate the process locally at each working point for the purpose of estimating steady-state derivatives, and the steady-state model is used for model-based optimisation. The performance lost caused by the inaccuracy of the steady-state model is compensated for by derivatives information which is obtained from dynamic data. The correct optimum can be achieved on-line even if both models are very rough. As shown in applications, the scheme is suited to various types of constraints and nonlinearities and is noise-insensitive.

Online searching aids: a review of front ends, gateways and other interfaces

Abstract: This review reports on the current state and the potential of tools and systems designed to aid online searching, referred to here as online searching aids. Intermediary mechanisms are examined in terms of the two stage model, i.e. end‐user, intermediary, ‘raw database’, and different forms of user — system interaction are discussed. The evolution of the terminology of online searching aids is presented with special emphasis on the expert/non‐expert division. Terms defined include gateways, front‐end systems, intermediary systems and post‐processing. The alternative configurations that such systems can have and the approaches to the design of the user interface are discussed. The review then analyses the functions of online searching aids, i.e. logon procedures, access to hosts, help features, search formulation, query reformulation, database selection, uploading, downloading and post‐processing. Costs are then briefly examined. The review concludes by looking at future trends following recent developments in computer science and elsewhere. Distributed expert based information systems (debis), the standard generalised mark‐up language (SGML), the client‐server model, object‐orientation and parallel processing are expected to influence, if they have not done so already, the design and implementation of future online searching aids.

Golgi tendon organs in the proximal tendon of sheep extraocular muscles.

Abstract: Sheep extraocular muscles were prepared for light and electron microscopy and their proximal tendons searched for Golgi tendon organs (GTO). An extensive aponeurotic lamina on the orbital surfaces contained numerous GTO 250–1350 μm in length with characteristic terminal form and relationship with collagen. They differed from usual GTO structure in containing large fluid-filled spaces dividing collagen into several well separated compartments and a muscle fiber entered and terminated in about one third of the receptors. The fibers, Felderstruktur in type, often penetrated deep within tendon organs, and in a few instances two or more fibers entered. This feature is shared by the rare GTO of monkey extraocular muscles. That the presence of GTO in the proximal tendons of extraocular muscles is previously unrecorded may be attributed to the practice of restricting attention to the long distal tendons. The possibility that receptors may be so placed in other species warrants further work especially in those purported to lack any receptor.

Viable Systems Diagnosis. 1. Application with a Major Tourism Services Group

Abstract: This paper outlines the rationale for using, and the application of, Viable Systems Diagnosis in a large-scale reorganization of a major tourism services group.

A review of the numerical analysis of blood flow in arterial bifurcations.

Abstract: Arterial bifurcation flow has been of special interest for some years because of its important role in the formation of atherosclerotic plaques and thrombi. To investigate the flow phenomena analytically, four major factors need to be accommodated--the three-dimensionality of a general bifurcation, the pulsatile nature of the laminar flow, the distensibility of the arterial wall and the non-Newtonian character of the blood. In this review, both engineering and medical aspects of each factor are carefully surveyed. It is demonstrated that the latest generation of computational fluid dynamics codes can treat this problem area and that it is both feasible and desirable to investigate the effects of each independent factor.

Non-mydriatic retinal photography as a screening service for general practitioners.

Abstract: Non-mydriatic retinal photography was offered as a screening service to 37 general practitioners providing diabetes care in their practices. Of 84 patients photographed, 22 had appearances of diabetic retinopathy and these were compared with 25 of the remainder without retinopathy. In only seven of 11 patients with maculopathy or proliferative retinopathy had this been detected by their GP and, likewise, only six of 11 cases of probable background retinopathy had been detected. The mean annual examination rate in general practice was 33 (95% Cl 18-47)%. Of the 18 cases in whom action in response to recommendations for follow-up or referral could be ascertained, 15 (83%) had had the recommendations implemented. Thus, despite the potential risks of false-negative screening using non-mydriatic retinal photography, the technique may improve the comprehensiveness of screening in patients under the care of their GPs.