Showing papers by "University of New South Wales published in 1993"

Probability of second law violations in shearing steady states.

Abstract: We propose a new definition of natural invariant measure for trajectory segments of finite duration for a many-particle system. On this basis we give an expression for the probability of fluctuations in the shear stress of a fluid in a nonequilibrium steady state far from equilibrium. In particular we obtain a formula for the ratio that, for a finite time, the shear stress reverse sign, violating the second law of thermodynamics. Computer simulations support this formula.

A nonsmooth version of Newton's method

Abstract: Newton's method for solving a nonlinear equation of several variables is extended to a nonsmooth case by using the generalized Jacobian instead of the derivative. This extension includes the B-derivative version of Newton's method as a special case. Convergence theorems are proved under the condition of semismoothness. It is shown that the gradient function of the augmented Lagrangian forC2-nonlinear programming is semismooth. Thus, the extended Newton's method can be used in the augmented Lagrangian method for solving nonlinear programs.

An analysis of the relationship between central aortic and peripheral upper limb pressure waves in man

Abstract: Amplification of the pressure pulse between central and peripheral arteries renders pressure values in the upper limb an inaccurate measure of ascending aortic (AA) pressure. Accuracy could be improved by allowance for such amplification. Transfer functions (TF) for pressures between AA and brachial artery (BA): (BATF) and between AA and radial artery (RA): (RATF) were derived from high-fidelity pressure recordings obtained at cardiac catheterization in 14 patients under control conditions, and after sublingual nitroglycerine 0.3 mg. There was no significant difference in BATF under control conditions and with nitroglycerine; hence results were pooled. Control and nitroglycerine results were also pooled to obtain a single RATF. BATF and RATF moduli peaked at 5 Hz and 4 Hz, reaching 2.5 and 2.8 times the value at zero frequency respectively. Frequency-dependent changes in modulus and phase of BATF and RATF were attributable to wave travel and reflection in the upper limb. BATF and RATF were compared to published transfer functions and those derived from analysis of aortic and brachial or radial pressure waves in previous publications. Results were similar. Our BATF and RATF were used to synthesize AA pressure waves from published peripheral pulses. Correspondence was close, especially for systolic pressure which d by 2.4 ± 1.0 (mean ± SEM) mmHg, whereas recorded systolic pressure differed by 20.4 ± 2.6 (mean ± SEM) mmHg between central and peripheral sites. Results indicate that in adult humans a single generalized TF can be used with acceptable accuracy to determine central from peripheral pressure under different conditions. While this process is capable of refinement, it represents an advance on the present practice of assuming that central and peripheral pressures are identical.

Convergence Analysis of Some Algorithms for Solving Nonsmooth Equations

Abstract: This paper presents convergence analysis of some algorithms for solving systems of nonlinear equations defined by locally Lipschitzian functions. For the directional derivative-based and the generalized Jacobian-based Newton methods, both the iterates and the corresponding function values are locally, superlinearly convergent. Globally, a limiting point of the iterate sequence generated by the damped, directional derivative-based Newton method is a zero of the system if and only if the iterate sequence converges to this point and the stepsize eventually becomes one, provided that the system is strongly BD-regular and semismooth at this point. In this case, the convergence is superlinear. A general attraction theorem is presented, which can be applied to two algorithms proposed by Han, Pang and Rangaraj. A hybrid method, which is both globally convergent in the sense of finding a stationary point of the norm function of the system and locally quadratically convergent, is also presented.

The Defense Style Questionnaire.

Abstract: The Defense Style Questionnaire has proven of interest as the first questionnaire to reliably describe defense styles. The 72-item DSM-III-R-labeled Defense Style Questionnaire was administered to 388 controls and 324 patients. Eight statistical and two a priori criteria were used in choosing two items to represent each of the 20 defenses. A new 40-item Defense Style Questionnaire is published together with normative and reliability data on a normal population, patients with anxiety disorders, and child-abusing parents. The scores are unaffected by the sex of the respondent, but the endorsement of immature defense styles decreases with age.

Behavioral Markers and Recognizability of the Smile of Enjoyment

Abstract: Ekman and Friesen (1982) predicted that smiles that express enjoyment would be marked by smoother zygomatic major actions of more consistent duration than the zygomatic major actions of nonenjoyment smiles. Study 1 measured the duration and smoothness of smiles shown by female subjects in response to positive emotion films while alone and in a social interaction. Enjoyment smiles in both situations were of more consistent duration and smoother than nonenjoyment smiles. In Study 2 observers who were shown videotapes of enjoyment and nonenjoyment smiles were able to accurately identify enjoyment smiles at rates greater than chance; moreover, accuracy was positively related to increased salience of orbicularis oculi action. In Study 3, another group of observers were asked to record their impressions of the smiling women shown in Study 2. These women were seen as more positive when they showed enjoyment compared with nonenjoyment smiles. These results provide further evidence that enjoyment smiles are entities distinct from smiles in general.

Poverty and economic growth with application to côte d'ivoire

Abstract: This paper explores the relation between economic growth and poverty, and develops the methodology to measure separately the impact of changes in average inccome and income inequality on poverty. This decomposition provides a link between macro economic adjustment policies and poverty which is discussed in the context of the adjustment experience of Cote d'Ivoire. The issue of targeting a poverty alleviation budget is shown to be related to the poverty decomposition proposed in the paper. The methodology proposed is applied to the data taken from the 1985 Living Standards Survey in Cote d'Ivoire.

The Strategic Management of Corporate Change

Abstract: To investigate the controversy between universal and contingent approaches to corporate change, a study was undertaken of 13 service sector organizations. The study used the Dunphy/Stace contingency model of organizational change strategies, developing measures to place the organizations within the model. Results indicate that universal models of change management are inadequate to describe the diversity of approaches actually used by these organizations. In particular, the traditional Organizational Development model is unrepresentative of how change in many contemporary organizations is actually made. The traditional OD model prescribes incremental change combined with a participative management style but most organizations in the study made rapid transformative change using a directive leadership style. The OD model is also inadequate as a prescriptive model because very different change strategies, some dramatically different from OD, resulted in successful financial performance. Four case studies are...

Calculation of the scattering length in atomic collisions using the semiclassical approximation.

Abstract: A simple analytical formula, [ital a]=[ital [bar a]][1[minus]tan([pi]/[ital n][minus]2)]tan[l brace][Phi][minus][[pi]/2([ital n][minus]2)][r brace], is obtained for the scattering length in atomic collisions. Here [ital [bar a]]=cos[[pi]/([ital n][minus]2)][l brace] [radical]2[ital M][alpha] /[[h bar]([ital n][minus]2)][r brace][sup 2]/([ital n][minus]2)[[Gamma]([ital n][minus]3)/([ital n][minus]2)]/[[ital T]([ital n][minus]1)/([ital n][minus]2)] is the mean scattering length determined by the asymptotic behavior of the potential [ital U]([ital r])[similar to][minus][alpha]/[ital R][sup [ital n]], ([ital n]=6 for atom-atom scattering or [ital n]=4 for ion-atom scattering), [ital M] is the reduced mass of the atoms, and [Phi] is the semiclassical phase calculated at zero energy from the classical turning point to infinity. The value of [ital [bar a]], the average scattering length, also determines the slope of the [ital s]-wave phase shifts beyond the near-threshold region. The formula is applicable to the collisions of atoms cooled down in traps, where the scattering length determines the character of the atom-atom interaction. Our calculation shows that repulsion between atoms ([ital a][gt]0) is more likely than attraction with a probability'' of 75%. For the Cs-Cs scattering in the [sup 3][Sigma][sub [ital u]] state, [ital [bar a]]=95.5[ital a][sub [ital B]] has been obtained, where [ital a][sub [ital B]] is the Bohr radius. The comparison of the calculated cross-section energymore » dependence with the experimental data gives evidence for a positive value for the Cs-Cs scattering length, which makes cesium Bose gas stable.« less

Evolutionary artificial neural networks

Abstract: Evolutionary artificial neural networks (EANNs) can be considered as a combination of artificial neural networks (ANNs) and evolutionary search procedures such as genetic algorithms (GAs). This paper distinguishes among three levels of evolution in EANNs, i.e. the evolution of connection weights, architectures and learning rules. It first reviews each kind of evolution in detail and then analyses major issues related to each kind of evolution. It is shown in the paper that although there is a lot of work on the evolution of connection weights and architectures, research on the evolution of learning rules is still in its early stages. Interactions among different levels of evolution are far from being understood. It is argued in the paper that the evolution of learning rules and its interactions with other levels of evolution play a vital role in EANNs.

Pterygium as an early indicator of ultraviolet insolation: a hypothesis.

Abstract: 'Among the many obscure points which puzzle the ophthalmic surgeon the condition of pterygium presents special difficulties; its origin, development, and its tendency to relapse and recurrence, all offer problems which are still to solve." Little has changed2 since these observations were made in 1918. The role of climate had been surmised, but in recent years quickening depletion of the ozone layer3 has focused attention on the biological consequences ofincreased ultraviolet insolation. There is now firm evidence that exposure to broad band ultraviolet radiation (290-400 nm) is associated with the development of pterygium.4 It has been predicted that a 1% increase in ultraviolet radiation would increase the incidence of pterygium by 2 5-14% in the Australian population." There are compelling reasons for reexaniing these consequences in the eye. Pterygium is perhaps the most obvious of the ophthalmohelioses7 (sun-related eye conditions) and can blunt sight in several different ways.8 In essence, it represents conjunctivalisation (and therefore loss oftransparency) of the cornea, usually commencing at the nasal limbus. In one study,9 however, 15% ofpterygia were located only temporally and in 11% of cases, pterygia were located nasally and temporally. There are several reviews dealing with the aetiology of this condition"0" yet a satisfactory explanation has remained elusive. As Rosenthal'7 concluded 'It has been analyzed statistically, geographically, etiologically, microscopically and chemically yet it grows onward primarily and secondarily.' Fuchs8 19 invoked inclement weather, smoke, and dust and suggested that the location was related to the degree of exposure of the bulbar conjunctiva which occurs when one 'squints' under these conditions. However, it has been noted in patients with divergent strabismus and pterygium, that pterygium does not affect the divergent eye in which the nasal bulbar conjunctiva is more exposed.20 In this review, the various theories of aetiology are reexamined. An attempt will be made to explain the location and shape of pterygia as well as factors involved in an individual's susceptibility to pterygium in the light of a new hypothesis.

Poverty, tnequaltty, and famtly living standards impacts across seven nations: the effect of noncash subsidies for health, education and housing

Abstract: The main aim of this paper has been to summarize the impact of noncash income–health and health education benefits, and imputed rent-on living standards, income distribution and poverty in seven nations at the beginning of the 1980s using the Luxembourg Income Study database. Our results do not give rise to a pattern of national differences in poverty rates or income inequality which are markedly different from that which emerges from previous LIS research based on cash income alone. While these results may be sensitive to the techniques used to measure and value noncash benefits in this paper, it appears that noncash income reinforces the redistributive impact or conventional (cash) tax-transfer mechanisms rather than acting to offset them in any major way.

Pathogenicity of Helicobacter pylori: a perspective.

Abstract: Nearly 10 years ago in Perth, Western Australia, an accidental period of prolonged incubation resulted in the growth of a Campylobacter-like organism, now known as Helicobacter pyloni (83, 130). Barry Marshall and Robin Warren's momentous discovery of this bacterium and its association with gastritis and peptic ulceration has revolutionized our perception of gastroduodenal disease. Since that time research data on this organism have grown considerably. This paper reviews current understanding of the pathogenesis of these diseases from an ecological perspective and identifies future research directions.

Mechanisms of acute and chronic intestinal inflammation induced by indomethacin

Abstract: The objective of this study was to characterize the mechanisms of acute and chronic intestinal mucosal injury and inflammation induced by subcutaneously injected indomethacin (Indo). One injection of Indo (7.5 mg/kg) produced acute injury and inflammation in the distal jejunum and proximal ileum that were maximal at three days and completely resolved within one week. Two daily subcutaneous injections of Indo produced a more extensive and chronic inflammation that lasted in an active form in more than 75% of the rats for at least two weeks. Epithelial injury, as measured by enhanced mucosal permeability, was significantly elevated only at one day in the acute model (one injection) but was persistently elevated in the chronic model (two injections). Bile duct ligation completely attenuated increased mucosal permeability in the acute model, however, depletion of circulating neutrophils had no effect. Neither Indo (0-0.1 mg/ml) nor normal bile was cytotoxic to cultured rat intestinal epithelial cells; however, they synergistically promoted significant cytotoxicity. Bile collected from rats treated with Indo was cytotoxic towards the epithelial cells in a dose-dependent manner. Sulfasalazine and metronidazole (100 mg/kg/day, both) attenuated enhanced mucosal permeability in the chronic model. Massive bacterial translocation into the mesenteric lymph nodes, liver, and spleen following two injections of Indo was significantly attenuated by metronidazole. We conclude that: (1) a single injection of Indo produces acute intestinal mucosal injury and inflammation that resolve completely within three to seven days, whereas two daily injections of Indo produce both acute and chronic injury and inflammation, (2) enterohepatic circulation of Indo is important in promoting the acute phases of injury and inflammation, (3) circulating neutrophils do not play a role in the pathogenesis of this model, and (4) endogenous bacteria play an important role in exacerbating and/or perpetuating the chronic phases of injury and inflammation.

Solar cell efficiency tables

Abstract: One regular feature planned for Progress in Photovoltaics is the publishing of solar cell and module efficiency tables summarizing the highest independently confirmed results for different technologies. These tables are expected to be of interest not only to researchers directly involved in these areas but also to those less directly involved but interested in being kept informed of the latest results with each of the different technologies or interested in an authoritative summary of these results. Other desirable outcomes may be the encouragement of research results and the further simulation of intercomparison of measurements between disignated cell test centres. Guidelines for inclusion of results into these tables are outlined and the first set of tables of results conforming to these guidelines are published.

CCLRU standards for success of daily and extended wear contact lenses.

Abstract: Success in contact lens wear is often judged on the basis of patient "survival" rather than the achievement of satisfactory performance based on specific criteria. In 1971, Sarver and Harris defined a series of standards for successful polymethyl methacrylate (PMMA) lens wear which incorporated criteria for wearing time, comfort, vision, ocular tissue changes, and patient appearance. In this paper we propose a revision of these criteria based on current understanding of the ocular response to contact lens wear. These revised CCLRU (Cornea and Contact Lens Research Unit) standards for success are intended as realistic performance objectives, and can be applied in clinical trials to evaluate and compare the clinical performance of present and future rigid and soft contact lenses, worn for daily and extended wear.

Kinetic study of steam reforming of methanol over copper-based catalysts

Abstract: Steam reforming of methanol has been studied over various copper-based catalysts at temperatures from 443 to 533 K. Screening experiments showed that a coprecipitated CuO-ZnO-Al2O3 low-temperature methanol synthesis catalyst had the highest activity and did not deactivate with time on line. It also exhibited 100% selectivity to carbon dioxide and hydrogen (the desired reaction products). Kinetic measurements made over the coprecipitated CuO-ZnO-Al2O3 were found to fit the power law expression: rSR=k0e–105kJ/mol/RTP0.26MeOHP0.03H2OP–0.2H2 Carbon dioxide was found to have no effect on the kinetics of steam reforming of methanol. When carbon monoxide was added to the feed there was negligible influence on the steam reforming reaction with an order of 0.016 being observed.

Respiratory sensations, cardiovascular control, kinaesthesia and transcranial stimulation during paralysis in humans.

Abstract: 1. To determine whether discomfort associated with breathing (dyspnoea) is related to the chemical drive to breath, three subjects were totally paralysed while fully conscious. Subjective responses to a rising CO2 stimulus were obtained during rebreathing, rebreathing with CO2 added, and breath holding. Dyspnoea was measured with a 10-point Borg scale. 2. Following nasotracheal intubation and ventilation (oxygen saturation, O2,Sat, 98-100% and end-tidal CO2, PET,CO2, 30-40 mmHg), total neuromuscular blockade was induced by a rapid injection of atracurium (> 2.5 mg kg-1) and complete paralysis was maintained with an infusion (5 mg (kg h)-1). Paralysis was confirmed by abolition of the compound muscle action potentials of both the diaphragm and abductor hallucis evoked by supramaximal electrical stimulation of the relevant nerves. Communication via finger movement was preserved for the first 20-30 min following paralysis by inflation of a sphygmomanometer cuff on one arm. 3. Before and during complete paralysis, dyspnoea increased progressively during hypercapnia produced by rebreathing (with or without CO2 added to the circuit at 250 ml min-1). The mean PET,CO2 eliciting 'severe' dyspnoea was 46 mmHg during rebreathing, 42 mmHg during 'breath holding', and 52 mmHg during rebreathing with added CO2. There were no significant differences between the values obtained during paralysis and in the control study immediately before paralysis. The duration of breath holding was not prolonged by paralysis and the PET,CO2 at the 'break point' was not altered by paralysis. 4. Thus, dyspnoea is preserved following total neuromuscular blockade. This suggests that chemoreceptor activity, via the central neuronal activity which it evokes, can lead to discomfort in the absence of any contraction of respiratory muscles. 5. During paralysis, attempted contraction of arm, leg and trunk muscles increased heart rate and blood pressure. For attempted handgrip contractions, the increases in heart rate (range, 7-15 beats min-1) and mean arterial pressure (range, 20-32 mmHg) were similar to those recorded with actual contractions in trials immediately before paralysis. In one subject, graded increases in heart rate and blood pressure occurred for attempted contractions of 45 s duration over a range of intensities (0-100% maximal effort). 6. During complete paralysis, transcranial electromagnetic stimulation of the motor cortex produced illusory twitch-like movements of the wrist and digits. This also occurred in separate studies during complete ischaemic paralysis and anaesthesia of the forearm and hand.(ABSTRACT TRUNCATED AT 400 WORDS)

Kinetic mechanism for the reaction between methanol and water over a cu-zno-al2o3 catalyst

Abstract: The steam reforming of methanol over a Cu/ZnO/Al 2 O 3 catalyst has been investigated. The reaction yields carbon dioxide and hydrogen in the ratio of one to three, with small amounts of dimethyl ether and carbon monoxide being produced at high conversion. Comparison of the rates of methanol dehydrogenation and of steam reforming over the same catalyst indicate that steam reforming proceeds via dehydrogenation to methyl formate. Methyl formate then hydrolyses to formic acid which decomposes to carbon dioxide and hydrogen. Detailed studies of the kinetics of the reactions show that methanol dehydrogenation controls the rate of steam reforming. Langmuir-Hinshelwood modelling indicates that hydrogen extraction from adsorbed methoxy groups is rate determining to the overall processes.

Pinatubo and pre-Pinatubo optical-depth spectra: Mauna Loa measurements, comparisons, inferred particle size distributions, radiative effects, and relationship to lidar data

Abstract: The Ames airborne tracking sunphotometer was operated at the National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory (MLO) in 1991 and 1992 along with the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) automated tracking sunphotometer and lidar June 1991 measurements provided calibrations, optical-depth spectra, and intercomparisons under relatively clean conditions; later measurements provided spectra and comparisons for the Pinatubo cloud plus calibration checks June 1991 results are similar to previous MLO springtime measurements, with midvisible particle optical depth tau(sub p)(lambda = 0526 microns) at the near-background level of 0012 +/- 0006 and no significant wavelength dependence in the measured range (lambda = 038 to 106 microns) The arrival of the Pinatubo cloud in July 1991 increased midvisible particle optical depth by more than an order of magnitude and changed the spectral shape of tau(sub p)(lambda) to an approximate power law with an exponent of about -14 By early September 1991, the spectrum was broadly peaked near 05 microns, and by July 1992, it was peaked near 08 microns Our optical-depth spectra include corrections for diffuse light which increase postvolcanic midvisible tau(sub p) values by 1 to 3% (ie, 00015 to 00023) NOAA- and Ames Research Center (ARC)-measured spectra are in good agreement Columnar size distributions inverted from the spectra show that the initial (July 1991) post-Pinatubo cloud was relatively rich in small particles (r less than 025 microns), which were progressively depleted in the August-September 1991 and July 1992 periods Conversely, both of the later periods had more of the optically efficient medium-sized particles (025 less than r less than 1 micron) than did the fresh July 1991 cloud These changes are consistent with particle growth by condensation and coagulation The effective, or area-weighted, radius increased from 022 +/- 006 micron in July 1991 to 056 +/- 012 micron in August-September 1991 and to 086 +/- 029 micron in July 1992 Corresponding column mass values were 48 +/- 07, 91 +/- 27, and 55 +/- 2 micro g/sq cm, and corresponding column surface areas were 44 +/- 05, 29 +/- 02, and 11 +/- 01 sq micron/sq cm, Photometer-inferred column backscatter values agree with those measured by the CMDL lidar on nearby nights Combining lidar-measured backscatter profiles with photometer-derived backscatter-to-area ratios gives peak particle areas that could cause rapid heterogeneous loss of ozone, given sufficiently low particle acidity and suitable solar zenith angles (achieved at mid- to high latitudes) Top-of-troposphere radiative forcings for the September 1991 and July 1992 optical depths and size distributions over MLO are about -5 and -3 W 1/sq m, respectively (hence comparable in magnitude but opposite in sign to the radiative forcing caused by the increase in manmade greenhouse gases since the industrial revolution) Heating rates in Pinatubo layer over MLO are 055 +/- 013 and 041 +/- 014 K/d for September 1991 and July 1992, respectively

Mathematical models of the photosynthetic response of tree stands to rising CO2 concentrations and temperatures

Abstract: Two published models of canopy photosynthesis, MAESTRO and BIOMASS, are simulated to examine the response of tree stands to increasing ambient concentrations of carbon dioxide (Ca) and temperatures. The models employ the same equations to described leaf gas exchange, but differ considerably in the level of detail employed to represent canopy structure and radiation environment. Daily rates of canopy photosynthesis simulated by the two models agree to within 10% across a range of CO2 concentrations and temperatures. A doubling of Ca leads to modest increases of simulated daily canopy photosynthesis at low temperatures (10% increase at 10°C), but larger increases at higher temperatures (60% increase at 30°C). The temperature and CO2 dependencies of canopy photosynthesis are interpreted in terms of simulated contributions by quantum-saturated and non-saturated foliage. Simulations are presented for periods ranging from a diurnal cycle to several years. Annual canopy photosynthesis simulated by BIOMASS for trees experiencing no water stress is linearly related to simulated annual absorbed photosynthetically active radiation, with light utilization coefficients for carbon of ɛ= 1.66 and 2.07g MJ−1 derived for Ca of 350 and 700 μmol mol−1, respectively.

Time Until Institutionalization and Death in Patients With Dementia: Role of Caregiver Training and Risk Factors

Abstract: • Objective. —To determine which variables best predict prognosis—time to nursing home admission (NHA) and death—in patients with dementia. Design. —Survival analysis employing the Cox proportional hazards model with the use of risk variables pertaining to dementia severity and its rate of progression and caregiver functioning. Setting. —Patients and their caregivers participating in a controlled intervention study of training for caregivers in home management of dementia. Participants. —Patients with mild Diagnostic and Statistical Manual of Mental Disorders, Third Edition —defined dementia (N=91; 68 patients with Alzheimer-type dementia, 20 with vascular dementia, and three with other types) and their caregivers. Follow-up. —All subjects had repeated assessments in the first year to determine rates of change and thereafter annually to determine the date of NHA and/or death. Risk Variables. —(1) Caregiver training; (2) dementia severity at index assessment; (3) caregiver stress, neuroticism, and socialization; (4) changes in patients and caregivers during the first 12 months; and (5) patient characteristics. Results. —By 5 years' follow-up, 76% of patients had entered a nursing home and 42% had died. Dementia severity and rate of deterioration ("how far" and "how fast") and caregiver psychological morbidity significantly influenced rates of NHA and death. Training of caregivers was significantly associated with delayed NHA and reduced mortality. Greater patient age, non-Alzheimer's dementia, and, unexpectedly, greater caregiver psychological morbidity were associated with shorter survival to death. Conclusions. —Both severity ("how far") and rate of deterioration ("how fast") influence time to NHA and death. Caregiver training may have important ameliorating effects on the prognosis of dementia.

Zidovudine in persons with asymptomatic HIV infection and CD4+ cell counts greater than 400 per cubic millimeter

Abstract: Background Zidovudine therapy is of benefit in the treatment of symptomatic and asymptomatic human immunodeficiency virus (HIV) infection in persons with CD4+ cell counts of less than 500 per cubic millimeter. The efficacy, safety, and duration of benefit of zidovudine in those with 500 or more CD4+ cells per cubic millimeter are uncertain. Methods In a double-blind, placebo-controlled trial, 993 patients with asymptomatic HIV infection and CD4+ cell counts above 400 per cubic millimeter were randomly assigned to receive zidovudine (500 mg twice daily) or placebo for three years. The primary end point was progression of disease, as defined by the development of Centers for Disease Control and Prevention (CDC) group IV disease (including recurrent oral candidiasis, hairy leukoplakia, or progressive diarrhea) or two CD4+ cell counts below 350 per cubic millimeter. This outcome measure was changed from the original end point of the acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex to...

Evidence for systematic evolution in the properties of galaxies in distant clusters

Abstract: This paper investigates the evolution of galaxies as a function of look-back time, primarily using early-type galaxies in rich cluster environments. We demonstrate that, by selecting distant galaxies in the near-infrared, representative samples containing approximately the same proportion of galaxy classes can be constructed independently of redshift, thus avoiding biases introduced by optical selection criteria. Using this method, we construct a sample of 180 galaxies selected at near-infrared wavelengths in the fields of 10 rich clusters with 0.5 < z < 0.9. Observing and data processing techniques, with infrared arrays yielding the required high-precision photometry of cluster members, are discussed

Multivariate models for predicting abstention following intervention to stop smoking by general practitioners

Abstract: Predictors of successful smoking cessation were examined in a randomized controlled trial of 450 smokers who received an intervention by their general practitioner (GP). Pretreatment characteristics predicting outcome at 3, 6 and 12 months and for continuous abstinence to 12 months were determined using logistic regression analyses. Results showed the variables that significantly predicted abstention at 3 months were age and motivation, whereas the predictors at 6 months were socio-economic status, motivation, level of dependence and time spent with smokers. No single predictor emerged at 12 months. Predictors for continuous abstinence to 12 months were age, time spent with smokers and motivation. A model was developed which best describes the likelihood of patients achieving continuous long-term abstinence. The results show that five factors (high motivation level, older age, less time spent with smokers, low dependence level, and higher socio-economic status) together have a 76% accuracy of predicting continuous abstinence to 12 months.