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Tree-ring cross-dates of 46 glacially killed trees show that the tidewater Nellie Juan Glacier, Alaska, advanced seaward during the 16th and 17th centuries AD. Ice-scarred trees at the late-Holocene end moraine indicate that the terminus was at its recent maximum from 1842 to 1893. Historical observations and photographs show that subsequent slow retreat changed to rapid iceberg-calving retreat after 1935, and that the tidewater terminus had withdrawn about 3.3 km from the late-Holocene maximum by 1992. Comparison with paleoclimate records from nearby land-terminating glaciers and an 850 year tree-ring-width chronology indicates that the timing of the 19th-century maximum stand of Nellie Juan Glacier was controlled by changes in summer temperature and radiation. However, rapid iceberg-calving retreat did not begin until 40 years of slow retreat had brought the tidewater terminus back from the terminal moraine shoal. Therefore, both the dimensions of the terminal moraine shoal and the magnitude and duration of climate change were important in initiating rapid retreat of this tidewater glacier system.
Introduction: Emergency department (ED) access block is the #1 safety concern in Canadian EDs. Its main cause is hospital access block, manifested by prolonged boarding of inpatients in EDs. Hospital administrators often believe this problem is too big to be solved and would require large increases in hospital capacity. Our objective was to quantify ED access gap by estimating the cumulative hours that CTAS 1-3 patients are blocked in waiting areas. This value, expressed as a proportion of inpatient care capacity, is an estimate of the bed hours a hospital would have to find in order to resolve ED access. Methods: A convenience sample of urban Canadian ED directors were asked to provide data summarizing their CTAS 1-3 inflow, the proportion triaged to nursed stretchers vs. RAZ or Intake areas, and time to care space. Total ED access gap was calculated by multiplying the number of CTAS 1-3 patients by their average delay to care space. Time to stretcher was captured electronically at participating sites, but time to RAZ or intake spaces was often not. In such cases, respondents provided time from triage to first RN or MD assessment in these areas. The primary outcome was total annual ED access block hours for emergent-urgent patients, expressed as a proportion of funded inpatient bed hours. Results: Directors of 40 EDs were queried. Six sites did not gather the data elements required. Of 34 remaining, 29 (85.3%) provided data, including 15 tertiary (T), 10 community (C) and 2 pediatric (P) sites in 12 cities. Mean census for the 3 ED types was 72,308 (T), 58,849 C) and 61,050 (P) visits per year. CTAS 1-3 patients accounted for 73.4% (T), 67.7% (C) and 66.2% (P) of visits in the 3 groups, and 34% (T), 46% (C) and 44% (P) of these patients were treated in RAZ or intake areas rather than staffed ED stretchers. Mean time to stretcher/RAZ care was 50/71 min (T), 46/62 min (C), and 37/59 min (P). Average ED access gap was 47,564 hrs (T), 37,222 hrs (C) and 35,407 hrs (P), while average inpatient bed capacity was 599 beds (5,243,486 hrs), 291 beds (2,545,875 hrs) and 150 beds (1,314,000 hrs) respectively. ED access gap as a proportion of inpatient care capacity was 0.93% for tertiary, 1.46% for community and 2.69% for pediatric centres. Conclusion: ED access gap is very large in Canadian EDs, but small compared to hospital operating capacity. Hospital capacity or efficiency improvements in the range of 1-3% could profoundly mitigate ED access block.
This study aimed to examine the dietary glycaemic index (GI) and glycaemic load (GL) of Australian children and adolescents, as well as the major food groups contributing to GL, in the recent 2011–2012 Australian Health Survey. Plausible food intake data from 1876 children and adolescents (51 % boys), collected using a multiple-pass 24-h recall, were analysed. The GI of foods was assigned based on a step-wise published method using values from common GI databases. Descriptive statistics were calculated for dietary GI, GL and contribution to GL by food groups, stratified by age group and sex. Linear regression was used to test for trends across age groups for BMI, dietary GI and GL, and intakes of energy, nutrients and food groups. Pearson’s χ2 test was used to test for differences between age groups for categorical subject characteristic variables. Mean dietary GI and GL of participants were 55·5 (sd 5·3) and 137·4 (sd 50·8), respectively. The main contributors to dietary GL were starchy foods: breads, cereal-based dishes, breakfast cereals, flours, grains and potatoes accounted for 41 % of total GL. Sweetened beverages, fruit and vegetable juices/drinks, cake-type desserts and sweet biscuits contributed 15 %. No significant difference (at P<0·001) was observed between sexes. In conclusion, Australian children and adolescents appear to consume diets with a lower GI than European children. Exchanging high-GI foods for low-GI alternatives within core and non-core foods may improve diet quality of Australian children and adolescents.
This is the official guideline endorsed by the specialty associations involved in the care of head and neck cancer patients in the UK and provides recommendations on the pre-treatment oral and dental assessment, during and after treatment and oral rehabilitation. Restorative dentists are core members of the multidisciplinary team treating head and neck cancer patients, involved from the treatment planning phase through to long-term rehabilitation.
• Preventative oral care must be delivered to patients whose cancer treatment will affect the oral cavity, jaws, salivary glands and oral accessibility. (G)
• Close working and communication between the surgeons, oncologists and restorative dental specialists is important in ensuring optimal oral health outcomes. (G)
• Intensity-modulated radiotherapy has been shown to reduce long-term xerostomia and should be offered to all appropriate patients. (R)
• If patients are deemed at risk of trismus they should be warned and its progressive and potentially irreversible nature explained. (G)
• Where it is known that adjuvant radiotherapy will be given, extractions should take place at primary surgery to maximise the time for healing and minimise the number of surgical events for patients. (G)
• Osseointegrated implants should be considered for all patients having resection for head and neck cancer. (G)
An estimated 800 million people live within 100 km of an active volcano in 86 countries and additional overseas territories worldwide [see Chapter 4 and Appendix B]1. Volcanoes are compelling evidence that the Earth is a dynamic planet characterised by endless change and renewal. Humans have always found volcanic activity fascinating and have often chosen to live close to volcanoes, which commonly provide favourable environments for life. Volcanoes bring many benefits to society: eruptions fertilise soils; elevated topography provides good sites for infrastructure (e.g. telecommunications on elevated ground); water resources are commonly plentiful; volcano tourism can be lucrative; and volcanoes can acquire spiritual, aesthetic or religious significance. Some volcanoes are also associated with geothermal resources, making them a target for exploration and a potential energy resource.
Much of the time volcanoes are not a threat because they erupt very infrequently or because communities have become resilient to frequently erupting volcanoes. However, there is an everpresent danger of a long-dormant volcano re-awakening or of volcanoes producing anomalously large or unexpected eruptions. Volcanic eruptions can cause loss of life and livelihoods in exposed communities, damage or disrupt critical infrastructure and add stress to already fragile environments. Their impacts can be both short-term, e.g. physical damage, and long-term, e.g. sustained or permanent displacement of populations. The risk from volcanic eruptions and their attendant hazards is often underestimated beyond areas within the immediate proximity of a volcano. For example, volcanic ash hazards can have effects hundreds of kilometres away from the vent and have an adverse impact on human and animal health, infrastructure, transport, agriculture and horticulture, the environment and economies. The products of volcanism and their impacts can extend beyond country borders, to be regional and even global in scale.
Although known historical loss of life from volcanic eruptions (since 1600 AD about 280,000 fatalities are recorded, Auker et al. (2013)) is modest compared to other major natural hazards, volcanic eruptions can be catastrophic for exposed communities. In 1985 the town of Armero in Colombia was buried by lahars (volcanic mudflows) with more than 21,000 fatalities due to relatively small explosive eruptions at the summit of Nevado del Ruiz volcano that partially melted a glacier (Voight, 1990).
Non-alcoholic fatty liver disease (NAFLD) is closely associated with insulin resistance and obesity. Hence, carbohydrate quality could be of relevance to the risk of NAFLD, but prospective data are lacking. The aim of the present study was to investigate longitudinal associations between carbohydrate quality (including dietary glycaemic index (GI) and intakes of sugar, starch and fibre) and markers of liver function in an older Australian population. The analysis was based on 866 participants ( ≥ 49 years) of the Blue Mountains Eye Study with fasting blood specimens and dietary intake data at baseline and 5-year follow-up. Multi-level mixed regression analysis was used to relate dietary GI and sugar, starch and fibre intake to the liver enzymes alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT), as well as fasting TAG and HDL-cholesterol (HDL-C). After adjustment for potential confounding factors, a lower fibre intake was cross-sectionally related to higher GGT (P= 0·02) and fasting TAG (P= 0·002) levels, with fruit fibre being the most relevant fibre source (P= 0·095 for GGT; P= 0·003 for TAG). A higher dietary GI was associated with lower HDL-C (P= 0·046). Changes in carbohydrate quality during 5 years were not related to changes in ALT, GGT, TAG or HDL-C (P≥ 0·08). In conclusion, the absence of longitudinal associations between carbohydrate quality and liver enzymes and serum lipids in this older population does not support a major role of carbohydrate nutrition in liver function among the elderly.
The Genesis 12–19 (G1219) Study is an ongoing longitudinal study of a sample of UK twin pairs, non-twin sibling pairs, and their parents. G1219 was initially designed to examine the role of gene–environment interplay in adolescent depression. However, since then data have continued to be collected from both parents and their offspring into young adulthood. This has allowed for longitudinal analyses of depression and has enabled researchers to investigate multiple phenotypes and to ask questions about intermediate mechanisms. The study has primarily focused on emotional development, particularly depression and anxiety, which have been assessed at multiple levels of analysis (symptoms, cognitions, and relevant environmental experiences). G1219 has also included assessment of a broader range of psychological phenotypes ranging from antisocial behaviors and substance use to sleep difficulties, in addition to multiple aspects of the environment. DNA has also been collected. The first wave of data collection began in the year 1999 and the fifth wave of data collection will be complete before the end of 2012. In this article, we describe the sample, data collection, and measures used. We also summarize some of the key findings to date.
Loch Obisary has a narrow sea inlet to a north basin which is 45 m deep, stratified in summer and winter and joined by shallow channels to an unstratifled south basin.
Mean conductivity (25°C) and sodium measurements indicate that in summer and winter the north basin epilimnion and the south basin comprises about 50%, and the north basin hypolimnion about 80%, sea water. It is calculated that 56% of high tides enter the loch.
Vertical diffuse attenuation coefficients for blue, green and red light are the same in epilimnion and south basin, the blue coefficient being slightly higher than the red in July and much higher in January. In July the blue coefficient in the hypolimnion is lower that the red, as in clear coastal water.
Six out of 24 macrophytes, and eight epiphytes, are confined within 200 m of the sea inlet. Distribution and depth limits of those and other species are discussed in relation to substrate, water chemistry and light. The presence of a halocline in the north basin and its absence from the south basin allow a comparison to be drawn between depth limits set by water chemistry (north basin), and those predicted on the basis of light (south basin) for Potamogeton pectinatus and Nitella opaca.
To develop a method for selecting health care–associated infection (HAI) measures for public reporting.
HAIs are common, serious, and costly adverse outcomes of medical care that affect 2 million people in the United States annually. Thirty-seven states have introduced or passed legislation requiring public reporting of HAI measures. State legislation varies widely regarding which HAIs to report, how the data are collected and reported, and public availability of results.
The Maryland Health Care Commission developed an HAI Technical Advisory Committee (TAC) that consisted of a group of experts in the field of healthcare epidemiology, infection prevention and control (IPC), and public health. This group reviewed public reporting systems in other states, surveyed Maryland hospitals to determine the current state of IPC programs, performed a literature review on HAI measures, and developed six criteria for ranking the measures: impact, unprovability, inclusiveness, frequency, functionality, and feasibility. The committee and experts in the field then ranked each of 18 proposed HAI measures. A composite score was determined for each measure.
Among outcome measures, the rate of central line–associated bloodstream infections ranked highest, followed by the rate of post–coronary artery bypass grafting surgical-site infections. Among process measures, perioperative antimicrobial prophylaxis, compliance with central-line bundles, compliance with hand hygiene, and healthcare-worker influenza vaccination ranked highest.
Our qualitative criteria facilitated consensus on the HAI TAC and provided a useful framework for public reporting of HAI measures. Validation will be important for such approaches to be supported by the scientific community.
Liquid crystalline epoxy networks have been prepared from glycidyl terminated polyether oligomers of varying molecular weight. These oligomers were prepared by functionalizing hydroxy terminated oligomers based on 4,4'- dihydroxy-α-methylstilbene and α,ω-dibromoalkanes with glycidyl groups. Curing of these oligomers was carried out either within their nematic mesophase or in their isotropic state. Different thermal properties were observed after curing under these two sets of conditions. Extremely low values of the coefficient of thermal expansion in the range of 15 to 60 ppm/°C were achieved. To produce aligned thermosets, orientation of the liquid crystalline phase was induced during the curing process by a magnetic field. Orientation of these networks was measured by wide angle x-ray diffraction (WAXD).
We have investigated the electronic properties of films of arsenic triselenide into which the transition metal nickel has been introduced by a co-sputtering technique. Measurement of d.c. conductivity, thermopower, optical absorption and photomobility have been performed to characterise the material. These measurements give new information concerning the influence of nickel on the optical gap, the position of the Fermi-level, and other aspects of transport in As2 Se3. In the most heavily doped sample the d.c. conductivity is increased by 11 orders of magnitude and the position of the Fermi-level is shifted by ΔEF∼0.6 eV. The results are explained in terms of a model in which an acceptor level is introduced into the valence band tail of a background density of states (DOS) obtained earlier for the undoped material. In contrast to the suggestion by previous workers that the incorporation of high concentrations of nickel can produce a transition to n-type conduction, we argue that the Fermi-level remains in the valence band tail and that hopping conduction of carriers close the Fermi-level yields a negative sign in thermopower.
New liquid crystalline thermosets have been prepared from end-functional monomers and oligomers of varying molecular weight. Both triazine and epoxy networks were explored. Of primary interest was the exploitation of the mesophase properties of these networks for developing polymers with high thermal stability and low coefficients of thermal expansion (CTE). Curing was carried out either within the nematic mesophase or the isotropic phase of the prepolymers. Transition temperatures associated with the mesophase were observed to change after curing under these two sets of conditions. The networks with the highest crosslink density were found to exhibit the lowest CTE values. Crosslinking of these thermosets was also carried out in the presence of a 13.5 Tesla magnetic field to determine the effect of orienting fields on the curing of the LC network. Orientation parameters as measured by wide angle x-ray diffraction were as high as 0.6. Values of the coefficient of thermal expansion as low as 15 ppm were achieved in the aligned direction. Of the two resin types, those with the triazine crosslinks had the lowest thermal expansion coefficient. Other thermal properties of these networks will be discussed.
In this work, the fracture toughness of monolithic pyrolytic carbon and sandwich composites of this carbon on a graphite substrate were measured by a disk-shaped compact specimen and by using a tensile specimen. On this material, a large number of specimens that had small cracks induced by a Vickers diamond indenter were tested under cyclic stress. The existence of a true threshold stress intensity factor range for non-propagation of the cracks was demonstrated. Statistical confidence on pre-cracked specimens was obtained through testing a large number of specimens to a very long lifetime of the order of 109 cycles.
We have evaluated the use of either poly(phenylene) prepared via spin-coatable polymeric precursors or fluorinated polysilynes for optical waveguides. Poly(phenylene) precursors were converted into poly(phenylene) by either curing at 300 °C or by deep-UV exposure in the presence of a photoacid generator. The poly(phenylene)s have a number of desirable properties for optical waveguide applications including good near IR transmission, low dielectric constant, thermal and environmental stability and ease of pattern fabrication using microlithographic techniques. Copolysilynes were spin-coated onto various types of substrates and then exposed by deep-UV radiation. Upon exposure of deep UV irradiation in the presence of air, they undergo photooxidative crosslinking to give insoluble glass-like materials. This photo-oxidation process is accompanied by a large decrease in refractive index from n=1.61 to n= 1.485. The photooxidation results suggest that their potential applications are as photoresists and optical waveguides.