1,064 research outputs found
Precipitation-Strengthened, High-Temperature, High-Force Shape Memory Alloys
Shape memory alloys (SMAs) are an enabling component in the development of compact, lightweight, durable, high-force actuation systems particularly for use where hydraulics or electrical motors are not practical. However, commercial shape memory alloys based on NiTi are only suitable for applications near room temperature, due to their relatively low transformation temperatures, while many potential applications require higher temperature capability. Consequently, a family of (Ni,Pt)(sub 1-x)Ti(sub x) shape memory alloys with Ti concentrations ranging from about 15 to 25 at.% have been developed for applications in which there are requirements for SMA actuators to exert high forces at operating temperatures higher than those of conventional binary NiTi SMAs. These alloys can be heat treated in the range of 500 C to produce a series of fine precipitate phases that increase the strength of alloy while maintaining a high transformation temperature, even in Ti-lean compositions
Seabed characterization: developing fit for purpose methodologies
We briefly describe three methods of seabed characterization which are ‘fit for purpose’, in
that each approach is well suited to distinct objectives e.g. characterizing glacial
geomorphology and shallow glacial geology vs. rapid prediction of seabed sediment
distribution via geostatistics. The methods vary from manual ‘expert’ interpretation to
increasingly automated and mathematically based models, each with their own attributes
and limitations. We would note however that increasing automation and mathematical
sophistication does not necessarily equate to improve map outputs, or reduce the time
required to produce them. Judgements must be made to select methodologies which are
most appropriate to the variables mapped, and according to the extent and presentation
scale of final maps
Emergency intubation in trauma in KwaZuluNatal Province South Africa
Background. Advanced airway management is a research priority in prehospital care. There is a high burden of major trauma in KwaZulu-Natal (KZN) Province, South Africa (SA), and transfer times to trauma units are often prolonged.Objectives. To examine emergency intubation practice in trauma and burns patients in Pietermaritzburg, KZN, and its environs.Methods. This was a prospective consecutive case series, conducted from 11 May to 17 July 2016. Data were collected from urban emergency department (ED), rural hospital and roadside procedures in Pietermaritzburg and its drainage area. Patients with emergency intubation following trauma were eligible for inclusion. The primary outcome was successful airway management. Secondary outcomes included first-pass success and adverse events.Results. Forty-one cases were recorded in patients aged 1 - 60 years. No instances of unsuccessful airway management were reported. Recorded first-pass intubation success rates were higher in receiving EDs than rural hospitals (19/22 v. 2/7; p=0.003). Use of a formal preintubation checklist was associated with a higher first-pass success rate (21/23 v. 6/15; p=0.001) and fewer adverse events (0/23 v. 7/16; p<0.001). Identified adverse event rates were 1/22 (EDs), 5/8 (rural hospitals) and 2/9 (roadside). Unmedicated intubation was more common in rural hospitals than EDs (3/8 v. 1/22; p=0.019), despite absence of cardiac arrest in these cases. Minimum standards of anaesthetic monitoring were not consistently met in any setting.Conclusions. The use of a preprocedural checklist was associated with improved intubation outcomes and may improve practice in SA trauma care and the prehospital environment, including in rural hospitals. Standardised rapid sequence induction protocols, routine use of introducers and end-tidal carbon dioxide monitoring, and increased availability of intraosseous devices also merit consideration. Key performance indicators should be monitored routinely.Â
What do community-dwelling Caucasian and South Asian 60–70 year olds think about exercise for fall prevention?
Background: strategies to prevent falls often recommend regular exercise. However, 40% of over 50s in the UK report less physical activity than is recommended. Even higher rates of sedentary behaviour have been reported among South Asian older adults
‘Omics-guided prediction of the pathway for metabolism of isoprene by Variovorax sp. WS11
Bacteria that inhabit soils and the leaves of trees partially mitigate the release of the abundant volatile organic compound, isoprene (2-methyl-1,3-butadiene). While the initial steps of isoprene metabolism were identified in Rhodococcus sp. AD45 two decades ago, the isoprene metabolic pathway still remains largely undefined. Limited understanding of the functions of isoG, isoJ and aldH and uncertainty in the route of isoprene-derived carbon into central metabolism have hindered our understanding of isoprene metabolism. These previously uncharacterised iso genes are essential in Variovorax sp. WS11, determined by targeted mutagenesis. Using combined ‘omics-based approaches, we propose the complete isoprene metabolic pathway. Isoprene is converted to propionyl-CoA, which is assimilated by the chromosomally encoded methylmalonyl-CoA pathway, requiring biotin and vitamin B12, with the plasmid-encoded methylcitrate pathway potentially providing robustness against limitations in these vitamins. Key components of this pathway were induced by both isoprene and its initial oxidation product, epoxyisoprene, the principal inducer of isoprene metabolism in both Variovorax sp. WS11 and Rhodococcus sp. AD45. Analysis of the genomes of distinct isoprene-degrading bacteria indicated that all of the genetic components of the methylcitrate and methylmalonyl-CoA pathways are not always present in isoprene degraders, although incorporation of isoprene-derived carbon via propionyl-CoA and acetyl-CoA is universally indicated
C-reactive protein: associations with haematological variables, cardiovascular risk factors and prevalent cardiovascular disease
C-reactive protein (CRP) has been proposed as a risk factor for cardiovascular disease; however, this association is confounded by mutual relationships with both classical and haematological cardiovascular risk factors. We, therefore, measured CRP with a high-sensitivity assay in stored plasma samples from 414 men and 515 women in the north Glasgow MONICA (MONItoring trends in CArdiovascular diseases) survey, to study its correlation with haematological variables, classical risk factors and prevalent cardiovascular disease. CRP correlated with age, oral contraceptive use, menopause and most classical cardiovascular risk factors (except blood pressure). CRP also correlated with plasma levels of the pro-inflammatory cytokine interleukin 6, and haematocrit, viscosity, red cell aggregation, white cell count, and coagulation factors [fibrinogen, factor (F) VII in women, FVIII, FIX] and inhibitors (antithrombin and protein C in women; protein S) but not coagulation activation markers. CRP was significantly associated with prevalent cardiovascular disease in both men (P = 0.03) and women (P = 0.009), however, the association became non-significant after adjustment for firstly classical risk factors, then fibrinogen. We conclude that correlations with classical and haematological risk factors account for a substantial component of the association of CRP with prevalent cardiovascular disease, but there is evidence of a residual, independent effect among women
Emergency intubation in trauma in KwaZulu-Natal Province, South Africa
Background. Advanced airway management is a research priority in prehospital care. There is a high burden of major trauma in KwaZulu-Natal (KZN) Province, South Africa (SA), and transfer times to trauma units are often prolonged.Objectives. To examine emergency intubation practice in trauma and burns patients in Pietermaritzburg, KZN, and its environs.Methods. This was a prospective consecutive case series, conducted from 11 May to 17 July 2016. Data were collected from urban emergency department (ED), rural hospital and roadside procedures in Pietermaritzburg and its drainage area. Patients with emergency intubation following trauma were eligible for inclusion. The primary outcome was successful airway management. Secondary outcomes included first-pass success and adverse events.Results. Forty-one cases were recorded in patients aged 1 - 60 years. No instances of unsuccessful airway management were reported. Recorded first-pass intubation success rates were higher in receiving EDs than rural hospitals (19/22 v. 2/7; p=0.003). Use of a formal preintubation checklist was associated with a higher first-pass success rate (21/23 v. 6/15; p=0.001) and fewer adverse events (0/23 v. 7/16; p<0.001). Identified adverse event rates were 1/22 (EDs), 5/8 (rural hospitals) and 2/9 (roadside). Unmedicated intubation was more common in rural hospitals than EDs (3/8 v. 1/22; p=0.019), despite absence of cardiac arrest in these cases. Minimum standards of anaesthetic monitoring were not consistently met in any setting.Conclusions. The use of a preprocedural checklist was associated with improved intubation outcomes and may improve practice in SA trauma care and the prehospital environment, including in rural hospitals. Standardised rapid sequence induction protocols, routine use of introducers and end-tidal carbon dioxide monitoring, and increased availability of intraosseous devices also merit consideration. Key performance indicators should be monitored routinely.
Trends in suicide in Scotland 1981 – 1999: age, method and geography
BACKGROUND: Male suicide rates continued to increase in Scotland when rates in England and Wales declined. Female rates decreased, but at a slower rate than in England and Wales. Previous work has suggested higher than average rates in some rural areas of Scotland. This paper describes trends in suicide and undetermined death in Scotland by age, gender, geographical area and method for 1981 – 1999. METHODS: Deaths from suicide and undetermined cause in Scotland from 1981 – 1999 were identified using the records of the General Registrar Office. The deaths of people not resident in Scotland were excluded from the analysis. Death rates were calculated by area of residence, age group, gender, and method. Standardised Mortality Ratios (SMRs) and 95% confidence intervals were calculated for rates by geographical area. RESULTS: Male rates of death by suicide and undetermined death increased by 35% between 1981 – 1985 and 1996 – 1999. The largest increases were in the youngest age groups. All age female rates decreased by 7% in the same period, although there were increases in younger female age groups. The commonest methods of suicide in men were hanging, self-poisoning and car exhaust fumes. Hanging in males increased by 96.8% from 45 per million to 89 per million, compared to a 30.7% increase for self-poisoning deaths. In females, the commonest method of suicide was self-poisoning. Female hanging death rates increased in the time period. Male SMRs for 1981 – 1999 were significantly elevated in Western Isles (SMR 138, 95% CI 112 – 171), Highland (135, CI 125 – 147), and Greater Glasgow (120, CI 115 – 125). The female SMR was significantly high only in Greater Glasgow (120, CI 112 – 128). CONCLUSION: All age suicide rates increased in men and decreased in women in Scotland in 1981 – 1999. Previous findings of higher than expected male rates in some rural areas were supported. Rates were also high in Greater Glasgow, one of the most deprived areas of Scotland. There were changes in the methods used, with an increase in hanging deaths in men, and a smaller increase in hanging in women. Altered choice of method may have contributed to the increased male deaths
Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu
The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's
New Frontiers Program and is the first U.S. mission to return samples from an
asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is
the selection of a prime sample-site on the surface of asteroid (101955) Bennu.
Mission success hinges on identifying a site that is safe and has regolith that
can readily be ingested by the spacecraft's sampling mechanism. To inform this
mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx
Camera Suite and the images are used to develop several foundational data
products. Acquiring the necessary inputs to these data products requires
observational strategies that are defined specifically to overcome the
challenges associated with mapping a small irregular body. We present these
strategies in the context of assessing candidate sample-sites at Bennu
according to a framework of decisions regarding the relative safety,
sampleability, and scientific value across the asteroid's surface. To create
data products that aid these assessments, we describe the best practices
developed by the OSIRIS-REx team for image-based mapping of irregular small
bodies. We emphasize the importance of using 3D shape models and the ability to
work in body-fixed rectangular coordinates when dealing with planetary surfaces
that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table
- …