Showing papers by "University of Newcastle published in 1994"
TL;DR: In this article, eight geochemical indices used for the interpretation of bottom water palaeo-oxygen concentrations for argillaceous sedimentary rocks have been calculated for a suite of Upper Jurassic mudstones drawn from the Draupne and Heather Formations of the Norwegian North Sea, and the Kimmeridge Clay Formation from onshore England.
1,551 citations
TL;DR: The zygapophysial joint is an important source of pain but the existence of a “facet syndrome” must be questioned.
Abstract: Study DesignThis study is a prospective cross-sectional analytic study.ObjectivesThe authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints.Summary of Background DataPrevious studies have demonstrated a wide range of prevalence for
543 citations
TL;DR: The scope and importance of the relationship between business and the environment, and a survey of the pitfalls and abuses are discussed in this article, with a focus on the role of the environment.
Abstract: The scope and importance of the relationship between business and the environment, and a survey of the pitfalls and abuses.
527 citations
TL;DR: In patients with chronic low back pain, the combination of discogenic pain and zygapophyseal joint pain is uncommon, and both procedures have both procedures been performed.
Abstract: Study Design.A prospective cross-sectional analytic approach was taken.Objectives.This study sought to determine the relative contribution of the disc and the zygapophyseal Joint as a pain source in patients with chronic low back pain.Summary of Background Data.Previous studies have employed either
401 citations
TL;DR: During 1981-91 mortality differentials widened between the most affluent and deprived fifths of wards in all age categories under 75 years, re-emphasise the case for linking mortality patterns with material conditions rather than individual behaviour.
Abstract: Objective: To identify relative and absolute changes in mortality in the Northern region of England between 1981 and 1991. Design: 1981 and 1991 census data were used to rank 678 wards on an index of material deprivation composed of four variables (unemployment, car ownership, housing tenure, household over-crowding). Standardised mortality ratios (all causes) were calculated for various periods between 1981 and 1991 and for different age categories. Setting: Counties of Cleveland, Cumbria, Durham, Northumberland, and Tyne and Wear. Results: During 1981-91 mortality differentials widened between the most affluent and deprived fifths of wards in all age categories under 75 years. The decline in the relative position of the poorest areas was particularly great, and there was no narrowing of inequalities across the remainder of the socioeconomic spectrum. In absolute terms, there were improvements in mortality in all age categories in the most affluent areas. In the poorest areas improvements in the 55-64 age group were balanced by increased mortality among men aged 15-44, a slight rise among women aged 65-74, and static rates among men aged 45-54. Conclusions: These results re-emphasise the case for linking mortality patterns with material conditions rather than individual behaviour.
350 citations
TL;DR: These features render uncontrolled diagnostic blocks unreliable for the diagnosis of lumbar zygapophysial joint pain not only in epidemiologic studies but also in any given patient.
Abstract: One hundred and seventy-six consecutive patients with chronic low back pain and no history of previous lumbar surgery were studied to determine the false-positive rate of single diagnostic blocks of the lumbar zygapophysial joints All patients underwent diagnostic blocks using lignocaine Those patients who obtained definite or complete relief from these blocks subsequently underwent confirmatory blocks using bupivacaine Eighty-three patients (47%) had a definite or greater response to the initial, lignocaine injection at one or more levels but only 26 (15%) had a 50% or greater response to a confirmatory injection of 05% bupivacaine Using the response to confirmatory blocks as the criterion standard, the false-positive rate of uncontrolled diagnostic blocks was 38% and the positive predictive value of these blocks was only 31% Because the positive predictive value of a test is lower when the pre-test probability (prevalence) is low, and because the prevalence of lumbar zygapophysial joint pain is likely to be less than 50%, uncontrolled diagnostic blocks will always be associated with an unacceptably low positive predictive value These features render uncontrolled diagnostic blocks unreliable for the diagnosis of lumbar zygapophysial joint pain not only in epidemiologic studies but also in any given patient
350 citations
TL;DR: In this article, a descriptive study of the motivational orientations of first year university students, using as its theoretical base the construct of mastery and performance goals, plus an additional goal of academic alienation, is presented.
322 citations
TL;DR: The fascicular anatomy of the trapezius was revealed and it was demonstrated that the fibres from C7, T1, and the lower half of ligamentum nuchae were the largest.
267 citations
TL;DR: Results suggest that cell-cell adhesion may be a vital regulator of colon development overcome in tumor cells by loss of adhesion molecules or of functional p53 protein.
Abstract: The LIM 1863 colon carcinoma cell line grows as structural organoids of goblet and columnar cells around a central lumen and provides a model for the development of stem cells in the normal colon. The organoid structure can be disrupted by removal of calcium from the medium, resulting in a suspension of single cells. Upon readdition of calcium, the cells reform the organoid structure over a period of 24 h, and ultrastructural examination of the reforming cells reveals that this involves a complex process that we have termed clutching. To determine the adhesion molecules involved in organoid formation we attempted to block this process by single cell suspensions of LIM 1863 reseeded in the presence of monoclonal antibodies. An anti-integrin antibody directed against a conformational epitope on the alpha v subunit totally inhibited organoid reformation. As a consequence of this inhibition of cell contact the colon carcinoma cells rapidly underwent apoptosis. Investigations of the apoptotic pathway involved suggested an induction mechanism since the onset of apoptosis in the contact-inhibited cells showed specific increased synthesis of 68- and 72-kD proteins. In addition, immunoblotting of cytosolic and nuclear extracts of the cells revealed the rapid translocation of the tumor suppressor gene product, p53 to the cell nucleus upon induction of apoptosis. These results suggest that cell-cell adhesion may be a vital regulator of colon development overcome in tumor cells by loss of adhesion molecules or of functional p53 protein.
263 citations
TL;DR: In this paper, the authors examined organizational commitment and perceived management styles using survey responses from 1418 employees from both public (N = 474) and private (n = 944) sector organizations, operating in Australia.
Abstract: Organizational commitment and perceived management styles were examined using survey responses from 1418 employees from both public (N = 474) and private (N = 944) sector organizations, operating in Australia. Comparisons between the two groups of employees revealed higher commitment among private sector employees. These differences were consistent with differences in perceived management styles. In agreement with previous research, factor analysis unveiled that the concept of organizational commitment was multidimensional. However, in the present study, that concept was found to incorporate the notion of "corporate loyalty/citizenship" and the notion of "attachment to the organization." The operational concept of management style used in the study was found to incorporate four subdimensions: (factor 1) the degree of "emphasis on flexibility and adaptation"; (factor 2) the degree of "emphasis on rules and regulations"; (factor 3) the degree of emphasis on "hierarchy and role specialization" and (factor 4)...
235 citations
TL;DR: In this article, the structure of turbulent boundary layers which develop with zero pressure gradient on a smooth wall and a k-type rough wall was examined using arrays of X-wires.
Abstract: The structure of turbulent boundary layers which develop with zero pressure gradient on a smooth wall and a k-type rough wall was examined using arrays of X-wires. Although the data were obtained only on two orthogonal planes, the technique provides some information on the three-dimensionality of the large-scale structures. The major effect of the roughness is to tilt the inclination of the structures towards the wall-normal direction. This is caused by the reduced damping of the wall-normal velocity fluctuations close to the rough surface and the break-up of structures whose scales are comparable to the size of the roughness elements. Both effects cause a reduction in the streamwise lengthscales, as suggested by all the measured two-point correlations. The correlations also show that the roughness tends to reduce the overall anisotropy of the large-scale motion. There is evidence to suggest that the magnitude of the vorticity field is larger over the rough wall.
TL;DR: Third occipital nerve headache is a common condition in patients with chronic neck pain and headache after whiplash and patients with a positive diagnosis were significantly more likely to be tender over the C2-3 zygapophysial joint.
Abstract: A consecutive series of 100 patients was studied to determine the prevalence of third occipital nerve headache in patients with chronic neck pain (> three months in duration) after whiplash. Seventy one patients complained of headache associated with their neck pain. Headache was the dominant complaint of 40 patients, but was only a secondary problem for the other 31. Each patient with headache underwent double blind, controlled diagnostic blocks of the third occipital nerve. On two separate occasions the nerve was blocked with either lignocaine or bupivacaine, in random order. The diagnosis of third occipital nerve headache was made only if both blocks completely relieved the patient's upper neck pain and headache and the relief lasted longer with bupivacaine. The prevalence of third occipital nerve headache among all 100 whiplash patients was 27% (95% confidence interval (95% CI) 18-36%) and among those with dominant headache the prevalence was as high as 53% (95% CI 37-68%). There were no distinguishing features on history or examination that enabled a definitive diagnosis to be made before the nerve blocks. Those patients with a positive diagnosis, however, were significantly more likely to be tender over the C2-3 zygapophysial joint (p = 0.01). Third occipital nerve headache is a common condition in patients with chronic neck pain and headache after whiplash. Third occipital nerve blocks are essential to make this diagnosis.
01 Jan 1994
TL;DR: This work defines a transmutation of a well-ordered system of spheres using ordinal conditional functions, and provides several conditions which capture the relationship between an Ordinal conditional function and an ordinal epistemic entrenchment function, and their corresponding transmutations.
Abstract: Within the AGM paradigm revision and contraction operators are constrained by a set of rationality postulates. The logical properties of a set of knowledge are not strong enough to uniquely determine a revision or contraction operation, therefore constructions for these operators rely on some form of underlying preference relation, such as a systems of spheres, or an epistemic entrenchment ordering. The problem of iterated revision is determining how the underlying preference relation should change in response to the acceptance or contraction of information. We call this process a transmutation. Generalizing Spohn’s approach we define a transmutation of a well-ordered system of spheres using ordinal conditional functions. Similarly, we define the transmutation of a well-ordered epistemic entrenchment using ordinal epistemic entrenchment functions. We provide several conditions which capture the relationship between an ordinal conditional function and an ordinal epistemic entrenchment function, and their corresponding transmutations. These conditions allow an ordinal epistemic entrenchment function to be explicitly constructed from an ordinal conditional function, and vice versa, in such a way that the epistemic state and its dynamic properties are preserved.
TL;DR: Intraarticular injection of betamethasone is not effective therapy for pain in the cervical zygapophyseal joints after a whiplash injury.
Abstract: Background Chronic pain in the cervical zygapophyseal joints is a common problem after a whiplash injury. Treatment with intraarticular injections of corticosteroid preparations has been advocated, but the value of this approach has not been established. We compared the efficacy of a depot injection of a corticosteroid preparation with the efficacy of an injection of a local anesthetic agent in patients with painful cervical zygapophyseal joints. Methods Sixteen men and 25 women with pain in one or more cervical zygapophyseal joints after automobile accidents (mean age, 43 years; median duration of pain, 39 months) were randomly assigned to receive a 1-ml intraarticular injection of either bupivacaine (0.5 percent) or betamethasone (5.7 mg) under double-blind conditions. The patients were followed by means of regular telephone contact and clinic visits until they reported a return to a level of pain equivalent to 50 percent of the preinjection level. The time from treatment to a 50 percent return of pain ...
Journal Article•
TL;DR: A review of the criteria of causation found that the relative risk of having a low-birth-weight baby is nearly doubled in women who smoke during pregnancy compared with nonsmoking women and the relative risks of spontaneous abortion and perinatal and neonatal mortality are increased by about one-third.
Abstract: Smoking during pregnancy has been associated with many adverse pregnancy outcomes. However, debate continues about whether smoking causes these outcomes. This review of the criteria of causation found that the relative risk of having a low-birth-weight baby is nearly doubled in women who smoke during pregnancy compared with nonsmoking women and that the relative risks of spontaneous abortion and perinatal and neonatal mortality are increased by about one-third. The magnitude of the long-term effects of maternal smoking on the physical and mental development of the offspring is small but measurable. The epidemiologic evidence associating maternal smoking with major adverse pregnancy outcomes in prospective and case-control studies displays a high degree of consistency. A dose-response gradient for smoking during pregnancy has not been clearly shown in relation to perinatal and neonatal mortality. However, there is strong support for a dose-response gradient in relation to low birth weight and spontaneous abortion and moderate support for long-term developmental effects. Although a biological causal mechanism has not been clearly delineated, considerable evidence indicates that the chemicals in tobacco smoke are capable of producing deleterious changes in the placenta and fetus.
TL;DR: The contribution of various network methodologies to bioprocess modelling, control and pattern recognition, and the contribution that neural networks can make to biochemical and microbiological scientific research is reviewed.
TL;DR: The results demonstrate that there is a net re absorption in the efferent ducts of nearly all the testicular output of water and inorganic electrolytes, and most of the protein, and that the ductus epididymidis is a negligible site of net fluid reabsorption.
Abstract: Luminal fluids were collected in vivo by micropuncture and cannulation from the rete testis, efferent ducts and ductus epididymidis of the rat to determine the composition of efferent duct fluids and the rates of reabsorption of water and solutes by the efferent ducts. The concentration of spermatozoa increased by a factor of about 25 from 2.42 x 10(4) microliters-1 in the fluid from the rete testis to 6.00 x 10(5) microliters-1 in fluid at the end of the efferent ducts, indicating that 96.2% of the fluid leaving the testis is reabsorbed from the lumen of the efferent ducts. Most of this reabsorption (70.9% or 33.4 microliters h-1) occurs in the region between the rete testis and the middle of the coni vasculosi, with only 25.1% (11.8 microliters h-1) occurring between the coni and the beginning of the ductus epididymidis. However, reabsorption across the epithelium occurs at about the same rate in both regions, with the proximal region reabsorbing 17.2 microliters cm-2 h-1 (70.9% of fluid entering the region) and the distal region reabsorbing 12.2 microliters cm-2 h-1 (86.1% of fluid entering the region). Consequently, the fluid reabsorption rate for the whole efferent duct system (15.6 microliters cm-2 h-1) is similar to the values for individual regions. The principal solutes in luminal fluids from the efferent ducts are Na+ (137-144 mM) and Cl- (113-130 mM). The estimated sum contribution of Na+, Cl- and K+ to the osmotic pressure of luminal fluids was approximately 80% at each site sampled in the efferent ducts. The osmotic pressure of luminal fluid samples (301-307 mosmol kg-1) did not vary significantly along the ducts or differ significantly from that of blood plasma. The results demonstrate that there is a net reabsorption in the efferent ducts of nearly all the testicular output of water and inorganic electrolytes, and most of the protein, and that, in comparison, the ductus epididymidis is a negligible site of net fluid reabsorption. The results indicate that the ductus epididymidis, rather than the efferent ducts, is the site of accumulation of high concentrations of specific organic compounds like inositol. The efferent ducts are similar to the homologous proximal tubules of the metanephric kidney in that the luminal electrolyte composition (principal solutes Na+ and Cl-) and osmotic pressure remain relatively stable and that fluid reabsorption is close to isotonic and occurs at the same rate as the reabsorption of Na+.
TL;DR: In this article, it has been suggested that a single overbank profile very rarely spans the period from before anthropogenic disturbance through to the Industrial Revolution and later, and significant lateral variations in metal concentrations occur also over a relatively small area in overbank sediments of the same general age.
TL;DR: The deterministic robust estimation problem is formulated in the discrete-time case as a zero-sum two person difference game, in which a statistician plays against nature, and the corresponding fixed-point, fixed-lag, and fixed-interval smoothing strategies are derived.
Abstract: The deterministic robust estimation problem is formulated in the discrete-time case as a zero-sum two person difference game, in which a statistician plays against nature. The statistician tries to estimate a linear combination of the states of an uncertain linear system, which is driven by nature. Saddle-point strategies for the statistician in the above game are difficult to find. A suboptimal strategy is, therefore, considered which guarantees an H/sub /spl infin// performance bound on the estimation error. Different patterns of the information that is available to the statistician are treated, and the corresponding fixed-point, fixed-lag, and fixed-interval smoothing strategies are derived. >
TL;DR: In this article, two simple models involving either lines or planes of interacting spherical particles are used to show that non-uniform distributions of spherical particles can give rise to large anisotropies.
TL;DR: The authors use a tool, which is novel in this context, namely, amplitude modulation theory, to analyze the quantitative and qualitative features of the intersample behavior in a frequency domain setting.
Abstract: Over the past 5 years, there has been substantial interest in the use of generalized sample hold functions for control. In this correspondence, the authors use a tool, which is novel in this context, namely, amplitude modulation theory. The authors employ this tool to analyze the quantitative and qualitative features of the intersample behavior in a frequency domain setting. This offers new theoretical and practical insights into the method. The authors' conclusion is that the perceived benefits come at substantial cost which makes its practical use questionable. >
TL;DR: In this article, a simulation of a fully developed turbulent channel flow for two relatively small values of the Reynolds number is used to examine its influence on various turbulence quantities in the near-wall region.
Abstract: Direct numerical simulations of a fully developed turbulent channel flow for two relatively small values of the Reynolds number are used to examine its influence on various turbulence quantities in the near-wall region. The limiting wall behaviour of these quantities indicates important increases in the r.m.s. value of the wall pressure fluctuations and its derivatives, the r.m.s. streamwise vorticity and in the average energy dissipation rate and the Reynolds shear stress. If the normalization is based on the wall shear stress and the kinematic viscosity, these changes are shown to be consistent with an increase in strength – but not the average diameter or average location – of the quasi-streamwise vortices in the buffer region. Evidence of this strengthening is provided by the increased sum of the stretching terms for the meansquare streamwise vorticity. It is also shown that a normalization based on Kolmogorov velocity and lengthscales, defined at the wall, is more appropriate in the near-wall region than scaling on the wall shear stress and kinematic viscosity.
TL;DR: The findings suggest that changes in solar protection are achievable with outdoor workers and that the intervention group showed a significantly greater improvement at posttest.
Abstract: OBJECTIVES. Outdoor workers are at high risk of developing skin cancer. Primary prevention in this group can potentially reduce the incidence of skin cancer, and also potentiates the spontaneous remission of existing solar keratoses. A randomized controlled trial was conducted to evaluate a solar protection intervention targeting outdoor workers. METHODS. Outdoor workers were randomly allocated to an intervention (n = 65) or control group (n = 77). The intervention group received individual skin screening by a dermatologist and participated in an education session. Pre- and posttest outcome measures included solar protection behavior (assessed using a validated diary), knowledge, and attitudes. RESULTS. There was a significant increase (16%) in the percentage of outdoor workers who were using a high level of solar protection at posttest compared to pretest in the intervention group, but there was no change in the control group. Although both groups improved in their knowledge score, the intervention group...
TL;DR: Whether there are relationships between problem drinking and high alcohol consumption and outcomes such as work injuries and related absences is investigated and age, Mortimer-Filkins test categories and job satisfaction significantly predicted injury-related absences.
Abstract: A review of studies on the relationship between alcohol and work injuries revealed that the evidence is contradictory and that many of the studies contain methodological flaws. The present study aimed to determine whether there are relationships between problem drinking and high alcohol consumption and outcomes such as work injuries and related absences. The sample consisted of 833 employees at an industrial worksite. Problem drinking was measured by the Mortimer-Filkins test, while alcohol consumption was measured by a 7-day retrospective diary. Work injury data were obtained from medical reports completed at the worksite medical center, while absences data were obtained from company records. Chi-square analyses revealed significant relationships between problem drinking and work injuries and injury-related absences, but not between high alcohol consumption and work injuries and related absences. Logistic regression analysis revealed that no variables were significant predictors of work injuries. However, when uninjured subjects were excluded, a second analysis revealed that Mortimer-Filkins test scores, recent stressful life events, age and job satisfaction were significant predictors of two or more injuries. Injured subjects were almost twice as likely to have two or more injuries if they had high numbers of recent stressful life events and low levels of job satisfaction. Logistic regression analysis revealed that age, Mortimer-Filkins test categories and job satisfaction significantly predicted injury-related absences. Problem drinkers were 2.7 times more likely to have injury-related absences than non-problem drinkers, and subjects with low levels of job satisfaction were 2.2 times more likely than others to have injury-related absences. The implications of the results for workplace alcohol policies and programs are discussed.
TL;DR: This study calls into question the validity of pain provocation alone as a criterion standard in patients undergoing diagnostic lumbar zygapophyseal joint blocks.
Abstract: OBJECTIVE To determine the relationship between pain provocation and the analgesic response in lumbar zygapophyseal joint blocks. DESIGN Consecutive patients undergoing intraarticular zygapophyseal joint blocks for the investigation of low back pain were included in this prospective study. SETTING The referred sample was from the metropolitan areas of New Orleans and San Francisco. PATIENTS Ninety patients with low back pain of > 3 months' duration and no history of lumbar surgery. INTERVENTIONS All patients underwent one or more intraarticular injections of radiographic contrast followed by lignocaine (lidocaine) 2% into zygapophyseal joints between L2-3 and L5-S1. Those with definite responses at one or more levels underwent confirmatory blocks using 0.5% bupivacaine. OUTCOME MEASURES Provocation of familiar pain and relief of pain after the injection of local anesthetic. Patients were assessed by an independent observer. RESULTS A total of 203 joints were studied. Adopting liberal criteria, either exact or similar reproduction of pain on the one hand correlated with either definite or complete relief of pain after a single, analgesic block on the other (p < 0.0001). However, when more stringent criteria were adopted, such as response to a confirmatory block using bupivacaine, there was no significant association. CONCLUSIONS This study calls into question the validity of pain provocation alone as a criterion standard in patients undergoing diagnostic lumbar zygapophyseal joint blocks.
TL;DR: Methods of clinical pain assessment in animals are reviewed, with reference to the techniques used in man, to enable the establishment of well validated clinical scoring systems, or identification of biochemical or physiological indices of pain or distress.
Abstract: The refinement of experimental techniques represents an important opportunity to improve the welfare of laboratory animals. Objective methods for the assessment of pain and distress in animals are needed before procedures that are claimed to be refinements can be evaluated. The methods currently used for assessment of pain and distress are unsatisfactory, and are often based on uncritical anthropomorphic assumptions. Future developments may enable the establishment of well validated clinical scoring systems, or identification of biochemical or physiological indices of pain or distress. If reliable methods of pain assessment can be developed, then a critical evaluation of the methods available for the alleviation of pain and distress can be undertaken. This article reviews methods of clinical pain assessment in animals, with reference to the techniques used in man. Techniques for pain alleviation are briefly reviewed.
01 Apr 1994
TL;DR: In this paper, it was shown that the C* -algebras generated by two semigroups V, W : P" and B{H) of nonunitary isometries are canonically isomorphic, thus giving a new, self-contained proof of Murphy's theorem.
Abstract: Let r+ be the positive cone in a totally ordered abelian group F. We construct crossed products by actions of r1" as endomorphisms of C- algebras, and give criteria which ensure a given representation of the crossed product is faithful. We use this to prove that the C* -algebras generated by two semigroups V, W : P" —» B{H) of nonunitary isometries are canonically isomorphic, thus giving a new, self-contained proof of a theorem of Murphy, which includes earlier results of Coburn and Douglas.
TL;DR: In this paper, a stochastic model for rainfall at a single site, in which storms arrive in a Poisson process, each storm generating a cluster of rain cells, with each cell having a random duration and a random intensity.
Abstract: This paper further develops a stochastic model for rainfall at a single site, in which storms arrive in a Poisson process, each storm generating a cluster of rain cells, with each cell having a random duration and a random intensity. The model is generalized by allowing each generated cell to be of n types. The duration of each cell is an exponential random variable that has parameter dependent on the cell type. The distribution of cell intensity is also dependent on the cell type, so that the generalized model provides a correlation between the intensities and durations of the generated rain cells. The case for two cell types is considered in some detail. The cells are categorized as either ‘heavy’ or ‘light9, where the heavy cells have a shorter expected lifetime than the light cells, which agrees with observational studies on precipitation fields. Properties are derived and used to fit the model to rainfall data at a single site. The adequacy of fit is assessed by considering properties not used in the fitting procedure but which are of interest in applications, e. g. extreme values. Further properties are derived which enable the model to be fitted to multi-site rainfall data.
TL;DR: None of the clinical features tested was found to be associated with response to the confirmatory block and the Fairbank et al. and Helbig and Lee criteria were shown to be unreliable in distinguishing pain of zygapophysial joint origin from pain of other origins.
Abstract: One hundred seventy-six consecutive patients with chronic low-back pain and no history of previous lumbar surgery were studied to test the clinical criteria of Fairbank et al. and Helbig and Lee for zygapophysial joint pain. All patients underwent a history, examination, and a series of zygapophysial joint injections or blocks of the medial branches of the dorsal ramus with lignocaine. Those patients responding to the first series of blocks were given confirmatory blocks using bupivacaine. None of the clinical features tested was found to be associated with response to the confirmatory block. The Fairbank et al. and Helbig and Lee criteria were shown to be unreliable in distinguishing pain of zygapophysial joint origin from pain of other origins.