Showing papers by "University of Newcastle published in 1990"
TL;DR: It is concluded that alpha-bungarotoxin binding proteins in the vertebrate nervous system can function as nAChRs.
926 citations
TL;DR: In this paper, a travaux relatifs a la reactivite chimique de metaux de transitions vis a vis de macrocycles substitues triaza, tetraaza et pentaaza, ions Co(III) and Ni(II), principalement.
319 citations
TL;DR: Most patients were satisfied with the opportunities provided to discuss their needs with doctors, the interpersonal support of doctors, and the technical competence of doctors; however, few patients were satisfaction with the provision of information concerning their disease, treatment, and symptom control and the Provision of care in the home and to family and friends.
Abstract: A diagnosis of cancer places considerable stress on patients and requires them to make major adjustments in many areas of their lives. As a consequence, considerable demands are placed on health care providers to satisfy the complex care needs of cancer patients. Currently, there is little available information to indicate the extent to which cancer patients are satisfied with the quality of care they receive. The present study assessed the perceptions of 232 ambulatory cancer patients about the importance of and satisfaction with the following aspects of care: doctors technical competence and interpersonal and communication skills, accessibility and continuity of care, hospital and clinic care, nonmedical care, family care, and finances. The results indicate that all 60 questionnaire items used were considered to reflect important aspects of care, but that greater importance was given to the technical quality of medical care, the interpersonal and communication skills of doctors, and the accessibility of care. Most patients were satisfied with the opportunities provided to discuss their needs with doctors, the interpersonal support of doctors, and the technical competence of doctors. However, few patients were satisfied with the provision of information concerning their disease, treatment, and symptom control and the provision of care in the home and to family and friends.
269 citations
TL;DR: In this article, a char morphology system based on the physical and optical characteristics known to influence the burning of pulverized coal is outlined, and the proportions of different pyrolysis char types produced by any coal are shown to depend on coal rank, petrographic composition, maceral fusibility, and possibly ash content and composition.
207 citations
TL;DR: Results suggest that an imbalance between monaminergic and cholinergic transmitters is involved in hallucinogenesis in the human brain.
Abstract: Senile dementia of Lewy body type is characterized clinically by a relatively acute onset of fluctuating memory loss and confusion, frequently accompanied by visual hallucinations. Neurochemical analyses of temporal cortex has revealed a distinction between hallucinating and nonhallucinating patients in both cholinergic and monaminergic transmitter activities. In contrast with the cholinergic enzyme choline acetyltransferase, which was more extensively reduced in hallucinating individuals, serotonergic S2 receptor binding and both dopamine and serotonin metabolites were significantly decreased in nonhallucinating cases. These results suggest that an imbalance between monaminergic and cholinergic transmitters is involved in hallucinogenesis in the human brain.
203 citations
TL;DR: Females had greater knowledge and stronger intentions to prevent skin cancer than males but reported fewer high-risk behaviors and other variables such as skin type and previous experience with skin cancer were more important.
Abstract: This study investigated knowledge, behaviors, and health beliefs of Australian university students (n=312) regarding skin cancers and evaluated the effects of videotaped presentations. Students' knowledge and health beliefs were assessed, and they then viewed either an informational video, an emotionally involving video, or a control video. Knowledge and beliefs were assessed immediately and 10 weeks later. Postvideo skin protection intentions increased significantly from prevideo assessment among the two intervention groups compared to the controls. Maintenance of skin protection intentions was higher with the emotional video. Health belief variables, particularly perceived barriers, were significant predictors of knowledge, intention, and behavior. However, other variables such as skin type and previous experience with skin cancer were more important. Females had greater knowledge and stronger intentions to prevent skin cancer than males but reported fewer high-risk behaviors.
202 citations
TL;DR: Analysis of clinical features of patients presenting with suspected sleep apnea may reduce the need for sleep studies by about one-third yet still lead to the identification of the great majority of patients with abnormal breathing during sleep.
Abstract: We have investigated the ability of a statistical model developed from clinical data and questionnaire responses to predict disturbance of breathing during sleep. Data from 100 consecutive patients referred for sleep study for suspected sleep apnea were used to develop the model using logistic regression analysis. For each subject, the model predicted the probability of having an apnea-hypopnea index (AHI) greater than 15; this probability was compared with the AHI measured from sleep study. A probability cutoff point (= 0.15) was decided on that minimized the number of subjects with false-negative predictions. Four terms--apneas observed by bed partner, hypertension, body mass index, and age--were found to contribute significantly to the model with observed apneas being by far the most predictive term of the four (adjusted odds ratio 19.7). When the model was tested to estimate the probability of an AHI greater than 15 for 105 patients from a second group of consecutive patients referred for sleep study, the model correctly classified 33 of 36 patients with a measured AHI greater than 15 (sensitivity = 92%) and 35 of 69 patients with a measured AHI less than or equal to 15(specificity = 51%). This study shows that analysis of clinical features of patients presenting with suspected sleep apnea may reduce the need for sleep studies by about one-third yet still lead to the identification of the great majority of patients with abnormal breathing during sleep.
196 citations
TL;DR: In this article, Proton sucrose symport is assessed as a possible mechanism for facilitated efflux of solutes across the sieve element plasma membrane to the sink apoplast.
Abstract: The transport and distribution of phloem – mobile solutes is predominantly determined by transport processes located at the sink end of the source – transport – sink system. Transport across the sieve element boundary, sieve element unloading, is the first of a series of sink transport processes. Unloading of solutes from the sieve elements may follow an apo- or symplastic route. It is speculated that the unloading pathway is integrated with sink function and that apoplastic unloading is restricted to situations in which movement through the symplast is not compatible with sink function. These situations include axial transport and storage of osmotically active solutes against concentration and turgor gradients between the sieve elements and sink cells. Coupled with alteration in sink function, the cellular pathway of unloading can switch in stems and possibly other sinks. Experimental systems and approaches used to elucidate the mechanism of sieve element unloading are reviewed. Unloading fluxes to the apoplast can largely be accounted for by membrane diffusion in axial sinks. However, the higher fluxes in storage sinks suggests dependence on some form of facilitated transport. Proton sucrose symport is assessed to be a possible mechanism for facilitated efflux of solutes across the sieve element plasma membrane to the sink apoplast. Unloading through the symplast may occur by diffusion or mass flow. The latter mechanism serves to dissipate phloem water and hence prevent the potential elevation of sieve element turgor that would otherwise slow phloem import into the sink. The possibility of energised plasmodesmatal transport is raised. Sieve element unloading must be integrated with subsequent compartmentation and metabolism of the unloaded solute. Solute levels are an obvious basis for control of sieve element unloading, but are found to offer limited scope for a mass action mechanism. Apoplastic, cellular pathway, sieve element, solute transport, symplastic. Translated into a turgor signal, solute levels could regulate the rate of unloading, metabolism and compartmentation forming part of a turgor homeostat irrespective of the pathway of unloading.
165 citations
TL;DR: In this article, the hydrous oxides of Mn, Fe, and Al avidly sorbed Sb from μM Sb(OH), solutions, with uptake levelling off as initial Sb concentration increased.
Abstract: The hydrous oxides of Mn, Fe, and Al avidly sorbed Sb from μM Sb(OH), solutions, with uptake levelling off as initial Sb concentration increased. Capacity values decreased along the sequence MnOOH > Al(OH)3 > FeOOH. The amount sorbed by each substrate decreased gradually at pH values > 6. Addition of 0.4M CH3COONa to the aqueous phase (to minimise retention of weakly bound Sb) had little effect on MnOOH uptake capacity (∼160 mmol, kg−1 at pH < 7) but retention dropped rapidly at higher pH. With the other two substrates (pH 6–7) the calculated capacity values for specific Sb sorption were ∼ 45 mmol kg−1 FeOOH and ∼ 33 mmol kg− Al(OH)3; about a third of the total capacity values. On these substrates specific Sb sorption tended to peak in the pH 7 to 8 region. The pH response pattern was modified using Sb tartrate sorbate solutions. Factors influencing Sb sorption included substrate surface charge, chemical form of Sb and surface interactions. Formation of a sparingly soluble metal coating was indicated by the uptake plateaus observed when increasing amounts of solid were added to Sb solutions containing acetate.
154 citations
TL;DR: In this paper, an alternative procedure, based on directing and correcting the importance sampling function as sampling is carried out, is presented, in particular it is possible to have a multi-modal sampling function.
148 citations
TL;DR: Results show that age-associated changes in paracetamol clearance are attributable to both changes in liver volume and in general health, and underline the important influences of the elderly person's physical state upon drug clearance.
Abstract: The association of age, physical frailty and liver size upon hepatic conjugation reactions was studied using paracetamol as a model drug. Nineteen fit subjects (mean age 26 years), 20 fit subjects (mean age 73 years), and eight frail, hospitalized subjects (mean age 82 years) were recruited. Paracetamol clearance expressed in terms of body weight was significantly lower in the fit elderly than in the fit young subjects, and was lowest in the frail elderly subjects (p less than 0.01). There was no difference in paracetamol clearance expressed per unit volume of liver between the fit young and fit elderly subjects but it was significantly reduced in the frail subjects. Although the partial metabolic clearance to paracetamol sulphate was preserved per unit volume of liver with ageing and frailty, the partial metabolic clearance to paracetamol glucuronide per unit volume of liver was markedly reduced in the frail elderly (p less than 0.01) when compared with the fit subjects. These results show that age-associated changes in paracetamol clearance are attributable to both changes in liver volume and in general health. The findings underline the important influences of the elderly person's physical state upon drug clearance.
TL;DR: In this article, a thick weathering profile of a Proterozoic carbonatite intrusion possesses exceptionally high REE contents in the form of abundant secondary phosphates and aluminophosphates.
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21 Dec 1990TL;DR: In this article, the authors consider the case of stationary Markov chains and stationary marked point processes and compare batch delays and customer delays continuity of queueing models further models - the stochastic equation with stationary coefficients - stability of robust filter cleaners - non-contractivity of the filters - the filter with fixed scale - variable scale.
Abstract: Recursive stochastic equations - weak and strong solutions - ergodic weak solutions - construction of stationary weak and strong solutions - Wald's identity for dependent random variables - model continuity in the presence of renewing epochs - method of metric modification - continuity of weak solutions the case of stationary Markov chains stationary sequences and stationary marked point processes - ergodic marked point processes continuous time models - stochastic processes with an embedded point process - semi-Markov and semi-regenerative processes - continuous time state processes - recursive stochastic equations in continuous time arrival-stationary queuing processes: existence and uniqueness - notations - the system - single server queue - the system with FCFS queueing discipline - the system with cyclic queueing discipline - the single server queue with warming-up - the many server loss system with repeated call attempts - open networks of loss systems relationships between arrival, time and departure stationary queueing processes - Poisson arrivals see time averages (PASTA) - the number of customers - the busy cycle - Takaes' and Pollaczek-Khinchin formulae batch-arrival stationary queuing processes - the system with geometrically distributed batch size - constant batch size - single server queue with batch arrivals - feedback queues - comparing batch delays and customer delays continuity of queueing models further models - the stochastic equation with stationary coefficients - stability of robust filter cleaners - non-contractivity of the filters - a further method for constructing solutions of recursive stochastic equations - the filter with fixed scale - variable scale.
TL;DR: In this paper, a general class of sampling distributions is considered, denoted as the class of mixed ǫ-gm-centred standard Gaussian and D -truncated ūgm-centered normal Gaussian distributions and the relative efficiency of different choices of the sampling distribution from the class is studied by way of examples for probability integration.
TL;DR: Attention to functional assessment by casualty staff may help to prevent readmission to hospital of this frail elderly group of patients.
Abstract: Four hundred and fifty patients aged 75 years or older were followed up after discharge from an accident and emergency department. Forty-three per cent of all patients experienced some loss of functional independence. A small number, 5.6%, were readmitted to hospital within 14 days. This group were significantly less able to perform certain activities of daily living than those not readmitted. Attention to functional assessment by casualty staff may help to prevent readmission to hospital of this frail elderly group of patients.
TL;DR: In this paper, a sidecan image of the central Lau Basin reveals a complex neotectonic framework in which the central lobe spreading center is actively propagating southward at the expense of the eastern lobe.
Abstract: GLORIA sidescan imagery of the central Lau Basin reveals a complex neotectonic framework in which the central Lau spreading center is actively propagating southward at the expense of the eastern Lau spreading center. The latter is located about 75 km closer to the active Tofua arc, and the transfer of spreading motion across this distance is achieved via a "relay" spreading-ridge segment. New magnetic and bathymetric interpretations suggest that the majority of the central and southern basin was formed by the eastern Lau spreading center between 5 Ma and the present day. The processes of arcward ridge migration, ridge propagation, and basinward arc migration may reflect the complex interplay of the subduction zone and regional tectonics in driving back-arc spreading, and may be a common feature of this tectonic environment.
TL;DR: The development and validation of an asthma knowledge questionnaire is described and it should prove to be a valuable research tool for the assessment of asthma knowledge either as part of an educational intervention or in a clinical situation.
Abstract: Asthma is responsible for much morbidity and mortality, which might be decreased by increasing parental and patient knowledge about asthma. This report describes the development and validation of an asthma knowledge questionnaire for use in the assessment of asthma knowledge. Two groups of respondents were examined. One group was designated 'high knowledge' and the other 'low knowledge'. The questionnaire had a maximum possible score of 31. The mean score of 69 'high' knowledge parents was 25.3 (median 25, range 18-31). By contrast, the mean score of 69 'low' knowledge parents was 13.0 (median 13, range 0-21). The difference between the two groups was statistically significant (P less than 0.0001). The questionnaire results were reproducible (tau = 0.94, P less than 0.01). Demographic characteristics such as education and socio-economic status were not important confounding variables. Face and content validity of the questionnaire were based on reference to published experience. Concurrent validity was demonstrated by the ability of the questionnaire to distinguish low from high knowledge parents. The questionnaire should prove to be a valuable research tool for the assessment of asthma knowledge either as part of an educational intervention or in a clinical situation.
TL;DR: A role for circulating CRH in the regulation of maternal cortisol secretion and significant relationships between maternal postnatal Mood States and beta-EP and between antenatal mood states and obstetric events are suggested.
TL;DR: In this paper, the problem of computing the frequency response of linear systems with parametric perturbation is addressed, and the results are useful in determining the H∞ norm, gain margin and phase margin and in improving the diagonal dominance of uncertain systems.
TL;DR: The goals of the Dubbo Study are to identify predictors of mortality, hospitalisation and placement in long-term care, while specific aims are the study of risk factors for chronic diseases and disability.
Abstract: The proportion of Australian population over 60 years has risen progressively over the last 40 years and this growth is projected to continue. Major health problems of the elderly include coronary heart disease, cerebro-vascular disease, osteoporosis and fracture. The risk factors for coronary heart disease and stroke in middle-aged subjects have been extensively documented in prospective studies in Australia and elsewhere, and include lipid disorders, hypertension, cigarette smoking, diabetes and family history. Few prospective studies have been targeted exclusively on the elderly and information available with respect to vascular risk factors is fragmentary and contradictory. This is the background to a new prospective study of the health of elderly Australians now under way in Dubbo, NSW. The goals of the Dubbo Study are to identify predictors of mortality, hospitalisation and placement in long-term care, while specific aims are the study of risk factors for chronic diseases and disability. This report describes the study rationale, reasons for selecting Dubbo as the study site, methods and measures, participation rates and demography. The target population included all non-institutionalised subjects 60 years and over, domiciled in Dubbo, and is comprised of 1693 males and 2167 females. The attendance rate for an extensive medical and sociological baseline assessment over a 13 months' period was 73% for both sexes. The prospective study is now in place and within three to five years will be generating definitive information in the elderly.
26 Jun 1990
TL;DR: The design of an extra performance architecture for Delta-4, which explicitly supports the requirements of real-time systems with respect to throughput and response, is presented and a solution based on message selection and preemption synchronization messages is proposed.
Abstract: The design of an extra performance architecture for Delta-4, which explicitly supports the requirements of real-time systems with respect to throughput and response, is presented. The Delta-4 approach to fault tolerance is based on the replication of software components on distinct host computers using a range of different replication strategies. The problems of replicate divergence are discussed, and a solution based on message selection and preemption synchronization messages is proposed. A description of the ongoing implementation of such a system within the overall Delta-4 framework is included. >
TL;DR: In this article, the bias of least squares and modified Yule-Walker estimators in a correctly specified multivariate autoregression of arbitrary order are obtained without assuming that the innovations are Gaussian.
Abstract: . Expressions for the bias of the least-squares and modified Yule-Walker estimators in a correctly specified multivariate autoregression of arbitrary order are obtained without assuming that the innovations are Gaussian. Instead, the innovations are assumed to form a martingale difference sequence which is stationary up to sixth order and which has finite sixth moments. The errors in the expressions are shown to be O(n-3/2), as the sample size n under some moment conditions. The expressions obtained are the same in the Gaussian and non-Gaussian cases.
TL;DR: A review of the literature located 24 published evaluations of the effectiveness of mass media programmes in modifying cardiovascular risk behaviour or safety restraint use among adults and found little support for the implementation of mass-media programmes to modify health risk behaviours.
Abstract: The mass media are increasingly popular as a strategy for delivering preventive health messages. A review of the literature located 24 published evaluations of the effectiveness of mass media programmes in modifying cardiovascular risk behaviour or safety restraint use among adults. Many of these studies failed to meet basic methodological criteria and were excluded from the review. The remaining studies were found to provide little support for the implementation of mass-media programmes to modify health risk behaviours. When
TL;DR: The hepatic clearance of many drugs is reduced in the elderly as mentioned in this paper, and an important contribution to reduced hepatic elimination is made by reduction in liver size and blood flow with advancing age.
Abstract: The hepatic clearance of many drugs is reduced in the elderly. Contrary to previously held views we suggest the following: 1. Specific activities of several cytochrome P-450 Phase I enzymes are not reduced with age per se in primate and man, nor is enzyme affinity for substrate changed. 2. An important contribution to the reduced hepatic elimination is made by reduction in liver size and blood flow with advancing age. 3. Major changes in liver drug metabolism may occur in frail old people. Future studies of hepatic drug metabolism and ageing must closely define the subject groups under study.
TL;DR: In this paper, the Reynolds shear stress and heat flux distributions at a number of streamwise stations in a heated circular jet into still air indicate that the flow is approximately self-preserving at x d = 15.
TL;DR: In this article, the Schwarz-Christoffel transformation is applied to generate the grid system around the wedge, and a pair of vortices are shed and they roll up into a single circular vortex.
Abstract: the incident vortex has its maximum tangential velocity at the radius of the core. At this instant, the incident vortex not only distorts but also splits into upper and lower vortices. The pair of shed vortices roll up into a strong vortex of circular shape. At t = 1.5, the split incident vortices interact with the flow in the boundary layer and are convected at different local velocities. The shed vortex is convected at a local velocity, which is much slower than that of the lower split incident vortex as shown in the figure. This occurs because the rotation of the shed vortex is opposite to that of the incident vortex. No additional vortex is shed near the leading edge as seen in the figure. This is because the local angle of attack becomes small. The vortex shedding process at t = 0.6 and t =0.9 is shown in detail in Fig. 2 , which clearly indicates that the vortex pair rolls up into a single circular vortex at / =0.9. Comparisions between the experimental results of Ref. 2 and the present computed ones are not included here because of the different structures and strengths of the incident vortices studied in the experiment and the present analysis. Nevertheless, the predicted distortion and splitting of the incident vortex, and vortex shedding near the leading edge have behaviors similar to those observed in the experiment.2 Conclusions Vortex-wedge interaction is investigated using the hybrid, vortex sheet-random vortex method, including viscous effects, and a fast vortex method, involving a large number of vorticity particles. The Schwarz-Christoffel transformation is applied to generate the grid system around the wedge. The shed vortex is formed by the vorticity particles generated all along the surface. Distortion of the incident vortex during the interaction and the appearance of a secondary shed vortex near the leading edge are clearly presented. A pair of vortices are shed and they roll up into a single circular vortex. It is presumed that a variety of shed vortex patterns may prevail depending upon the incident vortex size, strength, and initial position.
TL;DR: In this article, Collins et al. showed that the banded gneisses are the oldest part of the batholith; zircon U-Pb ages for three samples are 3429 ± 13Ma, ⩾ 3443 ± 10Ma and 3448 ± 8Ma, all very similar to the age of zircons in the felsic volcanic rocks near the base of the greenstone succession.
TL;DR: Overall the structured programme in its present form did not appear to be an effective programme for use within general practice and was highlighted in relation to the duration of the intervention.
Abstract: OBJECTIVE--To evaluate a structured, behavioural change, smoking cessation intervention designed for use within general practice. DESIGN--Randomised controlled clinical trial. SETTING--General practices in Newcastle, Australia. PATIENTS--311 Patients identified as smokers by a screening question were enrolled in the study. Of these, 101 were assigned to a structured behavioural change programme, 104 to a simple advice programme adapted from previous research, and 106 to a control group. No significant differences were found between groups for demographic and smoking related variables before the study. INTERVENTIONS--Patients in the simple advice group received a brief statement of advice from the general practitioner as well as three pamphlets; those in the structured intervention group were given strategies which included attitude and behavioural change programmes as well as techniques to aid compliance. The amount of smoking in all groups was assessed by self reports with validation by measurement of salivary cotinine concentrations. MAIN OUTCOME MEASURE--Significant increase in cessation rates. CONCLUSIONS--Significant differences between controls and the structured behavioural change group were found at the one month follow up, but only for self reported abstinence. The simple advice programme did not produce any significant differences over the control group. General practitioner evaluation of the structured programme highlighted difficulties in relation to the duration of the intervention. Overall the structured programme in its present form did not appear to be an effective programme for use within general practice.
TL;DR: Natterjack toads Bufo calamita have declined sharply at heathland sites in Britain during the 20th century, and a significant feature of these habitats is the predominance of oligotrophic and dystrophic ponds on substrates with low buffering capacities.