Search

The article offers information on oystercatchers and their battle for conservation. Oystercatchers can live up to 40 years or even longer. Such birds are said to be reproducing slowly with only one brood each year. Unlike most waders, the chicks of oystercatchers rely on their parents for food and usually take several months before they can eat shellfish by themselves. Eggs, on the other hand, face great risks because they are laid during summertime. Climate change is cited as another factor that threatens successful breeding.

The new ground being broken by the field of nanotechnology provides us with numerous prospects for treatment and prevention of infectious diseases. Recent reports have demonstrated that several types of nanoparticles act as potent free radical scavengers and antioxidants. Specific nanoconstructs are also reported to have anti-inflammatory activities. Given these properties, the potential application of antioxidant nanoparticles for controlling infectious diseases are discussed in this review. Numerous pathogenic agents establish their virulence and pathogenicity by virtue of their ability to produce free radicals and damage the cells of the immune system. For example, Pseudomonas aeruginosa is a bacterium that produces the toxin pyocyanin, which induces cell damage and compromises the immune system through production of reactive oxygen species (ROS). Nanoparticle antioxidants may provide unique opportunities to counteract the pathogenicity of these types of microorganisms and their formation of biofilms, which are also related to oxygen levels and ROS production. The use of nanoparticles may also play a role in controlling conditions such as ventilation associated pneumonia, where high levels of oxygen induces oxidative stress and inhibits respiratory tract immunity. In contrast, nanoparticle antioxidants, by virtue of their anti-inflammatory activity, may blunt a host's normal immune defenses to certain microorganisms. This review will address this emerging double-edged sword for nanomedicine and its potential role in controlling infectious disease and will address future directions for research in this emerging frontier.

The article discusses the Critically Endangered species categorized by the International Union for Conservation of Nature (IUCN) as extremely at high risk of extinction in the near future. Birdlife International established the Important Bird Areas (IBAs) to help conserve rare birds. A list of specie names, population sizes and trends, habitats and threats of around 27 Critically Endangered African breeding birds is presented.

To investigate whether overweight women are more likely to have a hysterectomy and whether hysterectomy leads to increased weight gain.

The aim of this study was to evaluate the relationship between adherence to bisphosphonate treatment by postmenopausal women and demographic, health, and lifestyle factors before treatment in a country with universal subsidies for pharmaceutical costs.

Objective:This study examined the relationships between combined categories of physical activity (PA) and Body Mass Index (BMI) with health care costs in women and assessed the potential cost savings of improving PA and BMI in sedentary mid‐age women. Methods:Cross‐sectional analysis of 2001 survey data linked to health service use data for the same year from 7,004 mid‐age women (50‐55 years) participating in the Australian Longitudinal Study on Women's Health. Results:The mean (median; interquartile range) annual cost of Medicare‐subsidised services was $542 (355; 156‐693) per woman. Costs were 17% higher in obese than in healthy‐weight women and 26% higher in sedentary than in moderately active women. For sedentary obese women, mean costs were 43% higher than in healthy weight, moderately active women. After adjustment for potential confounders, the relative risk of ‘high’ claims (≥15 claims per year) for overweight women who reported ‘moderate’ or ‘high’ PA were lower than for women with healthy BMI who reported no PA. Conclusions and Implications:Lower PA and higher BMI are both associated with higher health care costs, but costs are lower for overweight active women than for healthy‐weight sedentary women. At the population level these data suggest that there would be significant cost savings if all sedentary mid‐age women could achieve at least ‘low’ levels of PA (60‐150 minutes a week).

Mixed incontinence remains a complex clinical problem for urogynaecologists and generalists alike, as research for new treatments and interventions tend to focus on single-symptom groups. Those with mixed symptoms form a diverse group, which is difficult to study precisely. Recent studies, however, have aimed to classify the subgroups within this heterogeneous group so that the response to treatment can be determined with greater accuracy. This review aims to evaluate these advances and place the research in a clinical context.

ABSTRACTTo date, there has been little research into the sensuous dimensions of sporting activity. This paper seeks to address this lacuna and to expand the literature via an examination of one specific group: distance runners. Using data from a two-year collaborative autoethnography, the paper portrays the sensuous activity experienced by two runners as they traverse their routine training routes.

ABSTRACTThe bacterial communities present in the oral cavity and the lungs of 19 adult cystic fibrosis (CF) patients were compared by using terminal restriction fragment length polymorphism analysis of 16S rRNA gene PCR products amplified from nucleic acids extracted directly from bacteria in clinical samples. Sputum samples were not found to be subject to profound contamination by oral cavity bacteria. Evidence of colonization of the CF lung by certain oral bacterial species was found.

We have sought to enhance the sensitivity of conductometric gas microsensors through the design and fabrication of porous, three-dimensional tin oxide nanoparticle structures. Electrostatically controlled layer-by-layer processing in aqueous solutions was used to decorate sacrificial latex microspheres with Sb:SnO2 nanoparticles. To evaluate their sensing performance, these structures were then deposited as films, via micropipetting, on MEMS micro-hot-plate platforms with interdigitated electrodes. Prior to gas testing, rapid heating of the micro-hot-plates was used to remove the sacrificial latex templates, thereby revealing a 3-D structure composed of interconnected spherical tin oxide nanoparticle shells with porous ultrathin walls. Changes in film conductance, caused by exposure to test gases (methanol, carbon monoxide, benzene, water) in a dry air background, were measured at different temperatures. Hollow nanoparticle microsphere films exhibited partial selectivity for these different gases, good dynamic range at different temperatures and gas concentrations, and good repeatability and stability over long runs. These films also yielded approximately 3-fold and 5-fold increases in sensitivity to methanol when compared to SnO2 polycrystalline chemical vapor deposition films and Sb:SnO2 microporous nanoparticle films, respectively. Gains in sensitivity are attributed to the multiscale porous architecture of the hollow microsphere films. This architecture promotes gas diffusion and increases the active surface area.

ABSTRACTProgressive loss of lung function resulting from the inflammatory response to bacterial colonization is the leading cause of mortality in cystic fibrosis (CF) patients. A greater understanding of these bacterial infections is needed to improve lung disease management. As culture-based diagnoses are associated with fundamental drawbacks, we used terminal restriction fragment (T-RF) length polymorphism profiling and 16S rRNA clone data to characterize, without prior cultivation, the bacterial community in 71 sputa from 34 adult CF patients. Nineteen species from 15 genera were identified in 53 16S rRNA clones from three patients. Of these, 15 species have not previously been reported in CF lung infections and many were species requiring strict anaerobic conditions for growth. The species richness and evenness were determined from the T-RF length and volume for the 71 profiles. Species richness was on average 13.3 ± 7.9 per sample and 13.4 ± 6.7 per patient. On average, the T-RF bands of the lowest and highest volumes represented 0.6 and 59.2% of the total volume in each profile, respectively. The second through fifth most dominant T-RF bands represented 15.3, 7.5, 4.7, and 2.8% of the total profile volume, respectively. On average, the remaining T-RF bands represented 10.2% of the total profile volume. The T-RF band corresponding to Pseudomonas aeruginosahad the highest volume in 61.1% of the samples. However, 18 other T-RF band lengths were dominant in at least one sample. In conclusion, this reveals the enormous complexity of bacteria within the CF lung. Although their significance is yet to be determined, these findings alter our perception of CF lung infections.

Not Available

ABSTRACTPlasmacytoid dendritic cells (pcDC) and myeloid dendritic cells (myDC) are shown to express CD4 and low levels of CCR5 and CXCR4, but only myDC express DC SIGN, a C-type lectin that binds human immunodeficiency virus but does not mediate virus entry. Both DC types were more susceptible to infection with a macrophage than a lymphotropic strain of human immunodeficiency virus type 1, but pcDC were more readily infected than myDC.

Dendritic cells (DCs) are specialized antigen-presenting cells that have the unique ability to initiate a primary immune response. The effect of physiologic stress on circulating blood DCs has thus far not been studied. In this study, we applied a recently developed method of counting blood DCs to test the hypothesis that significant stress to the body such as surgery and exercise might induce measurable changes in the DC numbers, subsets, phenotype, and function. Twenty-six patients scheduled for elective laparoscopic cholecystectomy, 4 for elective hysterectomy, 56 controls, and 5 volunteers who underwent a stress exercise test were enrolled in the study. Absolute DC counts increased acutely (71.7% ± 11% [SEM],P =.0001) in response to the stress of surgery and dropped below preoperative levels (−25% ± 14% [SEM],P =.05) on days 2-3. The perioperative DC subset balance remained constant. Interestingly, DC counts changed independently of monocyte counts. Exercise also induced a rise in DC counts but coincidentally with monocyte counts. Surprisingly, no phenotypic or functional activation of DCs was seen in either stress situations in vivo. DCs are rapidly mobilized into the circulation in response to surgical and exercise stress, which may serve to prepare the host's immune defenses against trauma. The independent regulation of the DC and monocyte counts reinforces the distinction between these 2 cell populations.

Apolipoprotein (apo)A-IV is synthesized in the small intestine during fat absorption and is incorporated onto the surface of nascent chylomicrons. In circulation, apoA-IV is displaced from the chylomicron surface by high density lipoprotein-associated C and E apolipoproteins; this exchange is critical for activation of lipoprotein lipase and chylomicron remnant clearance. The variant allele A-IV-2 encodes a Q360H polymorphism that increases the lipid affinity of the apoA-IV-2 isoprotein. We hypothesized that this would impede the transfer of C and E apolipoproteins to chylomicrons, and thereby delay the clearance of postprandial triglyceride-rich lipoproteins. We therefore measured triglycerides in plasma, S(f) > 400 chylomicrons, and very low density lipoproteins (VLDL) in 14 subjects heterozygous for the A-IV-2 allele (1/2) and 14 subjects homozygous for the common allele (1/1) who were fed a standard meal containing 50 gm fat per m(2) body surface area. All subjects had the apoE-3/3 genotype. Postprandial triglyceride concentrations in the 1/2 subjects were significantly higher between 2;-5 h in plasma, chylomicrons, and VLDL, and peaked at 3 h versus 2 h for the 1/1 subjects. The area under the triglyceride time curves was greater in the 1/2 subjects (plasma, P = 0.045; chylomicrons, P = 0.027; VLDL, P = 0.063). A post-hoc analysis of the frequency of the apoA-IV T347S polymorphism suggested that it had an effect on triglyceride clearance antagonistic to that of the A-IV-2 allele. We conclude that individuals heterozygous for the A-IV-2 allele display delayed postprandial clearance of triglyceride-rich lipoproteins.

SummaryThe common mode of migration among Afrotropical birds is movement from tropical to temperate areas to breed usually coinciding with the onset of summer and the rainy season. The proportion of species that are migratory can be predicted with considerable accuracy from the average temperature of the coldest month of the year. Once this exceeds 20°C, 90% or more of breeding species will be non-migratory. The likelihood of any one species being migratory is strongly influenced by diet, foraging mode as influenced by the behaviour of prey and vegetation geography. Insectivores are disproportionately well represented among the migrants whereas, at the other extreme, frugivores are almost exclusively sedentary. Within the insectivore guild, the greatest migratory tendencies are found among those groups that exclusively hunt aerial insects above the canopy (e.g. swallows, swifts and nightjars), perch-hunters that depend on large, active insect prey (e.g. halcyonid kingfishers and rollers) and taxa heavily dependent on the larvae of flying insects (cuckoos). Insectivores that hunt or glean small invertebrates (volant or not) within the canopy or glean relatively sessile prey from the ground are much less likely to be migratory. This gradient, linking prey attributes and hunting behaviour to migratory behaviour, is probably mediated by a parallel gradient in seasonal prey availability. In marked contrast to the Neotropics and the Orient, many Afrotropical birds undertake polarised migrations, with part of the population moving north, and part south, of the tropics. The explanation of this is hypothesised to lie in the spatial symmetry and large extent of savannas both north and south of the tropics, coupled with a lack of north-south dispersal barriers. These conditions are not replicated in either the Neotropics or the Orient.

We investigated the effect of the A-IV-2 allele, which encodes a Q360H substitution in apolipoprotein (apo) A-IV, and dietary fat on cholesterol absorption in humans. In three separate studies we compared fractional intestinal cholesterol absorption between groups of subjects heterozygous for the A-IV-2 allele (1/2) and homozygous for the common allele (1/1) receiving high cholesterol ( approximately 800 mg/day) diets with different fatty acid compositions. All subjects had the apoE 3/3 genotype. There was no difference in cholesterol absorption between the two genotype groups receiving a high saturated fat diet (33% of total energy as fat; 18% saturated, 3% polyunsaturated, 12% monounsaturated) or a low fat diet (22% of total energy as fat; 7% saturated, 7% polyunsaturated, 8% monounsaturated) diet. However, on a high polyunsaturated fat diet (32% of total energy as fat; 7% saturated, 13% polyunsaturated, 12% monounsaturated) mean fractional cholesterol absorption was 56. 7% +/- 1.9 in 1/1 subjects versus 47.5% +/- 2.1 in 1/2 subjects (P = 0.004). A post hoc analysis of the effect of the apoA-IV T347S polymorphism across all diets revealed a Q360H x T347S interaction on cholesterol absorption, and suggested that the A-IV-2 allele lowers cholesterol only in subjects with the 347 T/T genotype.We conclude that a complex interaction between apoA-IV genotype and dietary fatty acid composition modulates fractional intestinal cholesterol absorption in humans.

Pulmonary surfactant in bronchoalveolar lavage fluid (BALF) and induced sputum from adults with stable asthma (n= 36) and healthy controls (n= 12) was analyzed for phospholipid and protein compositions and function. Asthmatic subjects were graded as mild, moderate, or severe. Phospholipid compositions of BALF and sputum from control subjects were similar and characteristic of surfactant. For asthmatic subjects, the proportion of dipalmitoyl phosphatidylcholine (16:0/16:0PC), the major phospholipid in surfactant, decreased in sputum (P< 0.05) but not in BALF.1In BALF, mole percent 16:0/16:0PC correlated with surfactant function measured in a capillary surfactometer, and sputum mole percent 16:0/16:0PC correlated with lung function (forced expiratory volume in 1 s). Neither surfactant protein A nor total protein concentration in either BALF or sputum was altered in asthma. These results suggest altered phospholipid composition and function of airway (sputum) but not alveolar (BALF) surfactant in stable asthma. Such underlying surfactant dysfunction may predispose asthmatic subjects to further surfactant inhibition by proteins or aeroallergens in acute asthma episodes and contribute to airway closure in asthma. Consequently, administration of an appropriate therapeutic surfactant could provide clinical benefit in asthma.

We have characterized the tensile creep, rupture lifetime, and cavitation behavior of a commercial, gas-pressure-sintered silicon nitride in the temperature range 1150° to 1400°C and stress range 70 to 400 MPa. Individual creep curves generally show primary, secondary, and tertiary creep. The majority of the primary creep is not recoverable. The best representation of the data is one where the creep rate depends exponentially on stress, rather than on the traditional power law. This representation also removes the need to break the data into high and low stress regimes. Cavitation of the interstitial silicate phase accompanies creep under all conditions, and accounts for nearly all of the measured strain. These observations are consistent with a model where creep proceeds by the redistribution of silicate phase from cavitating interstitial pockets, accommodated by grain-boundary sliding of silicon nitride.

The prevalence of abdominal aortic aneurysm (AAA) in Western Australia was studied using health department mortality data. Age-standardized and age-specific mortality rates related to the disease were calculated for the period 1980–88. The mortality rate has risen by 36 per cent for men and 24 per cent for women. Most of this rise was due to an increase in non-hospital and emergency admission hospital deaths. The number of elective and emergency operations has also risen. Despite two decades of elective surgery, the mortality rate for AAA continues to rise. This rise is highly suggestive of an increasing prevalence. This contrasts with the decline in deaths from other manifestations of arteriosclerosis and provides support for a policy of screening for aneurysm.

This is a population-based review of 153 cases of primary gastric lymphoma. Sixty-seven (43 per cent) were histologically reviewed using the Kiel classification. There were no significant differences between reviewed and unreviewed cases. Ninety-seven per cent of all cases were of the non-Hodgkin's type. The annual incidence was constant at 1.2 per cent of gastric malignancies. The mean age was 60 years and the male to female ratio 1:8. Presenting symptoms were similar to those of gastric cancer. Twenty-one per cent had a palpable mass but one-third of these were amenable to a potentially curative resection. Some 66 per cent were resectable and 58 per cent had a macroscopic clearance of tumour. TNM stage and absolute tumour size were significant prognostic factors (P<0.005 and P<0.05 respectively) but the Kiel classification was not. The overall 5 year survival was 24 per cent. Apart from 10 patients whose only anti-tumour treatment was radiotherapy (5 year survival 36.9 per cent) no patient who did not have curative surgery survived 5 years. The 5 year survival for curative resection was 34 per cent and for curative resection plus radiotherapy was 43.5 per cent (45 and 73.4 per cent for the node negative cases respectively). A laparotomy is essential; ‘curative’ surgery possibly with adjuvant radiotherapy offers the best hope for cure.

Objective:To produce comprehensive community based data on individuals with intellectual handicap, thé level of retardation, associated handicaps and demographic data. Design:Multiple sources of ascertainment were used to identify all children in birth cohorts, 1967‐1976 inclusive, who had an IQ less than 70. Setting:The majority of cases were ascertained through Western Australian government agencies that provide services for the intellectually handicapped. Other sources included thé support branch of the education department, private schools and the children's hospital. Patients:In all, 1602 children, aged between 6 arid 16 years, fitted the study criteria. Results:The prevalence of intellectual handicap was found to be 8.9 per 1000 live male births and 6.3 per 1000 live female births with an overall rate of 7.6. The figures for mild, moderate, severe and profound retardation were 3.0, 2.4, 1.0 and 0.6 per 1000, respectively, with 0.8 per 1000 with an unknown IQ. Cerebral palsy occurred in 20% and epilepsy in 13% in addition to intellectual handicap. There was a significantly higher rate among those from rural compared with urban areas: 9.9 v. 6.5 per 1000 live births, respectively. Conclusions:This comprehensive epidemiological data on intellectual handicap in Western Australia will be of value in the planning Of services, including screening and genetic counselling, and for the evaluation of care. The rural preponderance, in particular, is worthy of further evaluation.

Boobyer, M.G. & Hockey, P. A.R. 1994. Dietary opportunism in the Karoo Korhaan: consequence of a sedentary lifestyle in an unpredictable environment. Ostrich 65:32-38.The stomach contents of 15 Karoo Korhaans were analysed. Plant material predominated in the diets of both sexes (80% of stomach content mass), the remainder of the contents being arthropods (12% by mass) and gastroliths. At least 32 plant taxa were eaten: species which tolerate or favour disturbed conditions, especially Solanaceae and Asteraceae, were well represented. Seeds of the alien Atriplex semi-baccata were common in most stomachs. Several taxa appeared at low frequency, but were abundant when present, indicating dietary opportunism. The arthropod component of the diet was dominated by insects, especially termites, ants and weevils. Dietary opportunism and catholicism allow Karoo Korhaans to retain fixed territories throughout the year in an unpredictable environment. Their exploitation of ephemeral plants allows them to thrive in areas heavily impacted on by pastoralism, where they may act as important seed dispersers and thus play a role in the restoration of degraded landscapes.

Holding, D. H. The psychology of ches skill. Hillsdale, N. J.: Lawrence Erlbaum Associates. 1985. Pp. 271. ISBN 0-89859-575-4. £28.95.Brown, Fredick M. and Greaber, . Curtis (Eds.). Rhythmic aspects of behaviour. Hillsdale, N. J.: Lawence Erlbaum Associates. 1982. Pp. xvii + 483. ISBN 0-89859-168-6 £30.00.Harris, J. E. and Morris, P. E. (Eds.). Everyday memory, actins and absent-mindedness. London: Academic Press. 1984. Pp. 253. ISBN 0-12-32764-3. £27.50.Graesser, A. C. and Black, J. B. (Eds.). The psychology of questins. Hillsdale, N. J.: Lawrence Erlbaum associates. 1985. Pp. 383. ISBN 0-89859-444-8 $45.00, £36.00.Donchin, E. (Ed.). Congnitive psychophysiology : Event-related potentials and the study of cognition. Hillside, N. J.: Lawrence Erlbaum Associates. 1984. Pp. 428. ISBN 0-89859-150-3 £44.00.Oyama, S. The ontogeny of information : Development systems and evolution. Cambridge: Cambridge University Press. Pp. 206. Hardback : ISBN 0-521-32098-4. £22.50. Paperback: ISBN 0-521-31257-4. £8.95.Benser, D., Waller, T. G. and MacKinnon, G. E. (Eds.). Reading research: Advances in theory and practice, Vl. 5. Orlando, Fla.: Academic Press Inc. 1985. Pp. 356. ISBN 0-12-572305-9.Barr, A. and Feigenbaum, E. A. (Eds., Vols. 1 and 2). Cohen, P. R. and figenbaum, E. A. (Eds., Vol. 3). The handbook of atificial intelligence. Los Altos, Calif.: William Kaufmann, Inc. 1986. Paperback set: ISBN 0-86576-088-8. Pp. xiv + 409, xiii + 428, xviii+ 640. £69.00.Arnheim, R. New essays on the psychology of art. Berkeley: University of California Press, 1986. Pp. 331. ISBN 0-530-05553-5. £21.25.Ottoson, D. and Zeki, S. (Eds.). Central and perpheral mechanisms of colour vision. London: Macmillan. 1985. Pp. x +239. ISBN 0-333-39321-X. £60.00.Totman, R. Social and biological roles of language : The psychology of justification. London: Academic Press. 1985. Pp. 190. £39.50.Lynch, G., McGaugh, J. L. and Weinberger, N. M. (Eds.). Neurobiology of learining and memoryNew York: guilford. 1984. Pp. xiii + 528. ISBN 0-89862-645-5. £70.85.Weinberger, N. M., McGaugh, J. L. and Lynch, G. (Eds.). Memory systems of the brain. New York: Guilfrd. 1985. Pp. xiii + 514 ISBN 0-89862-666-8. £57.00.King, M. (Ed.). Parsing natural language. London: Academic Press. 1983. Pp. 308. ISBN 0-12-408280-7. $21.00.Cracco, R. Q. and Bodis-Wollner, I. (Eds.). Evoked potentials (Frontiers of clinical neuroscience, Vol, 3). New York: Alan R. Liss. 1986. Pp. xiv +551. ISBN 0-8451-4502-9. £98.05.Freeman, N. H. and Cox, M. V. Visual order : The nature and development of pictorial representation. Cambridge: Cambridge Unversity Press. 1985. Pp. 395. ISBN 0-521-26668-8. £27.50.Sndgrass, J. G., Levy-Berger, G. and Matin Haydon. Human experimental psychology. New York: Oxford University Press. 1985. Pp. 484. ISBN 0-19-503574-7. £30.00.Bradshaw, J. Basic experiments in neuropsychology. Amsterdam: Elsevier Science Publishers. 1986. Pp. 206. ISBN 0-444-80803-5. $42.25.Halpern, J. Y. (Ed.). Theoretical aspects of reasoning about knowledge: Proceedings of the 1986 Conference. Los Altos, CA: Morgan Kaufman. 1986. Pp. vii + 407. ISBN 0-934613-04-4. Paperback £ 18.95.Moore, B. C. J. (Ed.). Frequency selectivity in hearing. London: Academic Press. 1986. Pp. xv + 492. ISBN 0-12-505625-7. £49.50.Kandel, E. R. and Schwatz, J. H. (Eds.). Principles of neural science(Second Edition). New York: Elsevier. 1985. Pp. 979. ISBN 0-444-00944-2. £39.00.D. Frank Bensn and Eran Zaidel (Eds). The dual brain : Hemispheric specialization in humans. New York: Guilford Press. 1985. Pp. xviii +430. ISBN 0-89862-643-9. $49.95. £34.00.Posner, M. I. Chronometric explorations of mind: The third Paul M. Fitts lectures. Oxford: Oxford University Press. 1986. Pp. 271. ISBN 0-19-503999-8. £16.00.

This paper presents a study of the creep and creep rupture behaviour of hot-pressed silicon nitride reinforced with 30 vol% SiC whiskers. The material was tested in both tension and compression at temperatures ranging from 1100 to 1250°C for periods as long as 1000 h. A comparison was made between the creep behaviour of whisker-reinforced and whisker-free silicon nitride. Principal findings were: (i) transient creep due to devitrification of the intergranular phase dominates high-temperature creep behaviour; (ii) at high temperatures and stresses, cavitation at the whisker-silicon nitride interface enhances the creep rate and reduces the lifetime of the silicon nitride composite; (iii) resistance to creep deformation is greater in compression than in tension; (iv) the time to rupture is a power function of the creep rate, so that the temperature and stress dependence of the failure time is determined solely by the temperature and stress dependence of the creep rate; (v) as a consequence of differences in grain morphology and glass composition between whisker-free and whisker-reinforced material, little effect of whisker additions on the creep rate was observed.

This paper presents a cognitive-energetical framework for the analysis of effects of stress and high workload on human performance. Following Kahneman's (1973) model, regulation of goals and actions is assumed to require the operation of a compensatory control mechanism, which allocates resources dynamically. A two-level compensatory control model provides the basis for a mechanism of resource allocation through an effort monitor, sensitive to changes in the level of regulatory activity, coupled with a supervisory controller which can implement different modes of performance-cost trade-off. Performance may be protected under stress by the recruitment of further resources, but only at the expense of increased subjective effort, and behavioural and physiological costs. Alternatively, stability can be achieved by reducing performance goals, without further costs. Predictions about patterns of latent decrement under performance protection are evaluated in relation to the human performance literature. Even where no primary task decrements may be detected, performance may show disruption of subsidiary activities or the use of less efficient strategies, as well as increased psychophysiological activation, strain, and fatigue after-effects. Finally, the paper discusses implications of the model for the assessment of work strain, with a focus on individual-level patterns of regulatory activity and coping.

Between January 1988 and December 1989 a study to evaluate the Home Care Service of St Columba's Hospice (Edinburgh, UK) was undertaken. General opinions about the service were sought of patients, their carers, district nursing staff, general practitioners and the home care staff themselves. In addition, data on 66 patients were collected from their general practitioners, their district nursing sisters if applicable, the patients and/or their carers. The hospice records of the same patients were studied. It was possible, therefore, to collect information on specific patients from several sources, thereby constructing a complex and unique picture of their care seen from different perspectives. The data were assessed in relation to the hospice's declared aims of the home care service. The study also included analyses of ten years' records of all patients who had received home care within the hospice's outreach. Some weaknesses in communication were identified and there was a consistent plea by district nursing sisters and home care staff for earlier referral of patients. It is concluded that, on a general level, the home care service's aims were met.

Objective:To confirm the existence of regional differences in coronary death rates in Australia and New Zealand and to determine whether or not these are associated with parallel differences in the incidence of acute myocardial infarction. Design:Descriptive epidemiological study. Setting:Community based study. Subjects:Residents of Auckland, Newcastle and Perth aged 25–64 years admitted to hospital for acute myocardial infarction or dying from coronary heart disease between 1983 and 1987. Main outcome measures:Definite acute myocardial infarction or coronary death classified according to the criteria of the World Health Organization MONICA project. Results:This study confirms the marked variation, evident from official statistics, in mortality rates from ischaemic heart disease between Newcastle (high), Auckland and Perth (low). A different pattern is observed for the incidence of acute myocardial infarction and there are also obvious differences between centres in the case fatality ratios for all acute coronary events combined. Newcastle has the highest rate for all coronary events, particularly in women. Auckland is characterised by substantially higher case fatality ratios compared with the two Australian cities. This is due especially to higher rates of coronary death outside hospital. Perth, which has the lowest mortality rates and case fatality ratios in both men and women, has rates for admission to hospital for acute myocardial infarction and all cases of ischaemic heart disease that are disproportionately high in relation to the corresponding mortality rates. Conclusion:The differences in case fatality ratios between these three centres are not readily explained by artefacts related to enumeration or classification. Rather, they are most likely related to differences in the natural history of ischaemic heart disease in the three populations. Differences in medical management may also contribute to the substantial variation in mortality rates.

Data from the National Heart Foundation Risk Factor Prevalence Surveys of 1980 and 1983 were analysed to detect national trends in risk factors for vascular disease in Australia. After statistical adjustment for differences in the demographic characteristics of the two populations of survey participants, our results show trends in smoking and blood pressure that are likely to result in a continuing fall in the incidence of vascular disease. There was a fall in the prevalence of current smoking from 32% to 29% but little change in the average daily consumption of cigarettes by current smokers. The prevalence of previously‐undetected hypertension fell significantly from 10% to 7%. A small increase occurred in the proportion of all hypertensive patients who were treated and whose blood pressure was controlled, and a decline of 2.0 mmHg (P< 0.0001) in mean diastolic blood pressures, but no significant change in mean systolic pressures. Mean total plasma cholesterol levels did not change; average levels of plasma triglycerides fell by 0.11 mmol/L (P< 0.0001); and mean high‐density lipoprotein cholesterol levels increased by 0.03 mol/L (P< 0.0001). All indices of relative body weight increased between 1980 and 1983; mean body mass index rose by 0.23 with associated rises in the prevalence of obesity and of overweight status. The changes in other factors such as use of added salt, the consumption of alcohol, the level of physical activity and adherence to a special diet, all were in the desirable direction, although minor changes in the survey questionnaire might have served to exaggerate the apparent trends.