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Submarine landforms in polar fjords provide essential insights into glacier responses to climate change in the Maritime Antarctic. This work aims to reconstruct the groundline of a palaeo-ice stream throughout the Holocene in Admiralty Bay, King George Island. The landforms were investigated using multi-resolution topobathymetric data based on seismic and multibeam surveys. The inner sector features shallow moraine banks and elongated glacial lineations, in contrast to the deeper moraine banks observed in the middle and outer regions of the fjord. Elongated glacial lineations indicate a north-east to south-west ice flow and a wet-based thermal regime. At ~9000 years bp, the grounding line was at the Admiralty Bay fjord’s mouth. In the middle of the fjord, a prominent morainal bank reveals the palaeoglacier’s grounding line. The grounding line significantly changed position after this stillstand in response to climatic variability (Mid-Holocene, at 4500–2800 years bp) and was conditioned by the deep bathymetry. The continued retreat of the ice in the Holocene possibly led to a division of the palaeo-ice stream into outlets or tidewater glaciers. MB7 and MB9 indicate the position of the grounding line during a major stillstand at the end of the inlets. The bedrock topography and fjord geometry influenced the deglaciation pattern of Dobrowolski Glacier in Martel Inlet, and the moraine banks recorded two final major stillstands. The retreat rates in Martel Inlet have increased due to the loss of anchoring points and rising temperatures after the Neoglacial period. The morainal banks present in the proximal environments at Martel Inlet are smaller, discontinuous and spaced, indicating the retreat behaviour in the last 7 decades.
Prior studies evaluating the impact of discontinuation of contact precautions (DcCP) on methicillin-resistant Staphylococcus aureus (MRSA) outcomes have characterized all healthcare-associated infections (HAIs) rather than those likely preventable by contact precautions. We aimed to analyze the impact of DcCP on the rate of MRSA HAI including transmission events identified through whole genome sequencing (WGS) surveillance.
Design:
Quasi experimental interrupted time series.
Setting:
Acute care medical center.
Participants:
Inpatients.
Methods:
The effect of DcCP (use of gowns and gloves) for encounters among patients with MRSA carriage was evaluated using time series analysis of MRSA HAI rates from January 2019 through December 2022, compared to WGS-defined attributable transmission events before and after DcCP in December 2020.
Results:
The MRSA HAI rate was 4.22/10,000 patient days before and 2.98/10,000 patient days after DcCP (incidence rate ratio [IRR] 0.71 [95% confidence interval 0.56–0.89]) with a significant immediate decrease (P = .001). There were 7 WGS-defined attributable transmission events before and 11 events after DcCP (incident rate ratio 0.90 [95% confidence interval 0.30–2.55]).
Conclusions:
DcCP did not result in an increase in MRSA HAI or, in WGS-defined attributable transmission events. Comprehensive analyses of the effect of transmission prevention measures should include outcomes specifically measuring transmission-associated HAI.
Increasing numbers of children with perinatally acquired HIV (PaHIV) are transitioning into adult care. People living with behaviourally acquired HIV are known to be at more risk of psychosis than uninfected peers. Young adults living with PaHIV face numerous risk factors; biological: lifelong exposure to a neurotrophic virus, antiretroviral medication and immune dysfunction during brain development, and environmental; social deprivation, ethnicity-related discrimination, and migration-related issues. To date, there is little published data on the prevalence of psychotic illness in young people growing up with PaHIV.
Methods
We conducted a retrospective case note review of all individuals with PaHIV aged over 18 years registered for follow up at a dedicated clinic in the UK (n = 184).
Results
In total, 12/184 (6.5%), median age 23 years (interquartile range 21–26), had experienced at least one psychotic episode. The presentation and course of the psychotic episodes experienced by our cohort varied from short-lived symptoms to long term illness and nine (75%) appear to have developed a severe and enduring mental illness requiring long term care.
Conclusion
The prevalence of psychosis in our cohort was clearly above the lifetime prevalence of psychosis in UK individuals aged 16–34 years, which has been reported to be 0.5–1.0%. This highlights the importance of clinical vigilance regarding the mental health of young people growing up with PaHIV and the need to integrate direct access to mental health services within the HIV centres providing medical care.
Longer-lived cows tend to be more profitable and the stayability trait is a selection criterion correlated to longevity. An alternative to the traditional approach to evaluate stayability is its definition based on consecutive calvings, whose main advantage is the more accurate evaluation of young bulls. However, no study using this alternative approach has been conducted for Zebu breeds. Therefore, the objective of this study was to compare linear random regression models to fit stayability to consecutive calvings of Guzerá, Nelore and Tabapuã cows and to estimate genetic parameters for this trait in the respective breeds. Data up to the eighth calving were used. The models included the fixed effects of age at first calving and year-season of birth of the cow and the random effects of contemporary group, additive genetic, permanent environmental and residual. Random regressions were modeled by orthogonal Legendre polynomials of order 1 to 4 (2 to 5 coefficients) for contemporary group, additive genetic and permanent environmental effects. Using Deviance Information Criterion as the selection criterion, the model with 4 regression coefficients for each effect was the most adequate for the Nelore and Tabapuã breeds and the model with 5 coefficients is recommended for the Guzerá breed. For Guzerá, heritabilities ranged from 0.05 to 0.08, showing a quadratic trend with a peak between the fourth and sixth calving. For the Nelore and Tabapuã breeds, the estimates ranged from 0.03 to 0.07 and from 0.03 to 0.08, respectively, and increased with increasing calving number. The additive genetic correlations exhibited a similar trend among breeds and were higher for stayability between closer calvings. Even between more distant calvings (second v. eighth), stayability showed a moderate to high genetic correlation, which was 0.77, 0.57 and 0.79 for the Guzerá, Nelore and Tabapuã breeds, respectively. For Guzerá, when the models with 4 or 5 regression coefficients were compared, the rank correlations between predicted breeding values for the intercept were always higher than 0.99, indicating the possibility of practical application of the least parameterized model. In conclusion, the model with 4 random regression coefficients is recommended for the genetic evaluation of stayability to consecutive calvings in Zebu cattle.
During the period 1970–1990 the Military Aircraft Division of British Aerospace based at Warton developed a structural sizing and optimisation system initially based on an “in-house” developed finite element analysis (FEA) system. This subsequently progressed to using NASTRAN, which was rapidly evolving to be the standard FEA system used within all divisions of British Aerospace (BAe).
The many problems associated with the development and application of this evolving system are described. These problems covered a wide range from software development, engineering application, resource management and hardware dependence.
One problems which has received a great deal of attention since 1990 is the incorporation of the panel buckling constraint particularly when applied to laminated structures. This paper describes an early attempt to incorporate this constraint followed by a brief description of the application and integration of a specialised Panel Buckling code.
The paper concludes by describing how BAe Military Aircraft Division is attempting to incorporate the buckling constraint using NASTRAN into a high performance computing (HPC) environment. In addition this development illustrates how many of the problems described earlier are being overcome by working in partnership with software vendors, hardware vendors and other business units within BAe.
Phytophagous orchard mites have become so troublesome in British Columhia during the last decade that special attention has been given to studies on their ecology and control. An important prerequisite for such studies is an accurate and rapid method of estimating population densities of both the mites and their predators. As some mites are less than a fifth of a millimetre long, it is difficult to determine the numbers of adults present on foliage, quite apart from the eggs and other immature stages.
Methods for estimating orchard mite populations developed to date may be classified as either direct, in which the mites are counted on the leaves or estimated, or indirect, in which the mites are removed from the leaves and a known fraction is counted.
Lignans are widely occurring plant compounds and are closely related to lignin, which forms the woody component of trees and other plants. The lignans are characterized by their dimeric composition from cinnamic acids, and they are attracting increasing attention as a result of their pharmacological properties. The volume surveys the chemical, biological and clinical properties of lignans as well as providing information on their isolation, purification, identification and chemical synthesis. The volume also explores fully the potential use of these compounds as antiviral and antitumour agents, and thus provides a wide-ranging survey of their pharmacology and chemistry. The text is fully documented and referenced and provides the only up-to-date compilation on this subject. The volume is suitable for research scientists in the fields of organic chemistry, biochemistry, oncology, pharmacology, toxicology and botany.
The metal-catalyst-free growth of carbon nanotubes (CNTs) using chemical vapor deposition and the application in field-effect transistors (FETs) is presented. The CNT growth process used a 3-nm-thick Ge layer on SiO2 that was subsequently annealed to produce Ge nanoparticles. Raman measurements show the presence of radial breathing mode (RBM) peaks and the absence of the disorder induced D-band, indicating single walled CNTs (SWNTs) with a low defect density. The synthesized CNTs are used to fabricate CNTFETs and the best device has a state-of-the-art on/off current ratio of 3×108 and a steep sub-threshold slope of 110 mV/decade.
Experimental animal studies have shown that nicotine exposure during gestation alters the expression of fetal hypothalamic neuropeptides involved in the control of appetite. We aimed to determine whether the exposure to maternal smoking during gestation in humans is associated with an altered feeding behavior of the adult offspring. A longitudinal prospective cohort study was conducted including all births from Ribeirão Preto (São Paulo, Brazil) between 1978 and 1979. At 24 years of age, a representative random sample was re-evaluated and divided into groups exposed (n = 424) or not (n = 1586) to maternal smoking during gestation. Feeding behavior was analyzed using a food frequency questionnaire. Covariance analysis was used for continuous data and the χ2 test for categorical data. Results were adjusted for birth weight ratio, body mass index, gender, physical activity and smoking, as well as maternal and subjects’ schooling. Individuals exposed to maternal smoking during gestation ate more carbohydrates than proteins (as per the carbohydrate-to-protein ratio) than non-exposed individuals. There were no differences in the consumption of the macronutrients themselves. We propose that this adverse fetal life event programs the individual's physiology and metabolism persistently, leading to an altered feeding behavior that could contribute to the development of chronic diseases in the long term.
We report evidence for graphene layer rearrangements in heavy ion interactions with carbon onions at 140 MeV and 70 MeV per nucleon kinetic energies. Graphene layer rearrangements have been recently predicted in spherical and cylindrical multi-layer graphene systems. The implications of graphene layer rearrangement on the tribological performance of multi-layer nano-carbons in extreme environments are discussed.
A technique to synthesize high-quality single walled carbon nanotubes (SWNTs) using chemical vapour deposition (CVD) on Ge Stranski-Krastanow dots has been developed. From transmission electron microscopy and Raman measurements, the grown carbon nanotubes (CNTs) are identified as SWNTs with diameters ranging from 1.6 to 2.1 nm. Extensive scanning electron microscopy and atomic force characterisation of the effect of each stage in the growth process is presented. Our hypothesis is that pre-treatment stages lead to the formation of Ge nanoparticles, which act as seeds for CNT growth. This technique demonstrates the ability to synthesize high-quality SWNTs without the need for a metal catalyst, using processes and equipment standard to a silicon foundry.
The business meeting of Commission 36 was held during the General Assembly in Prague on 16 August. It was attended by about 15 members. The issues presented included a review of the work made by members of Commission 36, and the election of the new Organising Committee. We note that a comprehensive report on the activities of the commission during the last triennium has been published in Reports on Astronomy, Transactions IAU Volume XXVIA. The scientific activity of the members of the commission has been very intense, and has led to the publication of a large number of papers.
Commission 36 covers all the physics of stellar atmospheres. The scientific activity in this large field has been very intense during the last triennium and led to the publication of a large number of papers which makes an exhaustive report practically not feasible. As a consequence we decided to keep the format of the preceding report: first a list of areas of current research, then web links for obtaining further information.
Heavy ion irradiations of single and multi walled carbon nanotubes and total ionization dose of gallium nitride nanowires were investigated. Post irradiation analyses of samples were performed with transmission and scanning electron microscopy, atomic force microscopy and micro Raman spectroscopy.