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Significant intra-annual variability in flow rates of tidewater-terminating Arctic glaciers has been observed in recent years. These changes may result from oceanic and/or atmospheric forcing through (1) perturbations at the terminus, such as enhanced submarine melt and changes in sea-ice buttressing, or (2) increased surface melt, in response to atmospheric warming, reaching the bed and promoting glacier slip. We examine the influence of these processes on Belcher Glacier, a large fast-flowing tidewater outlet of the Devon Island ice cap in the Canadian Arctic. A hydrologically-coupled higher-order ice flow model is used to estimate changes in glacier flow speed as a result of changes in sea-ice buttressing and hydrologically-driven melt-season dynamics. Daily run-off from five sub-catchments over the 2008 and 2009 melt seasons provides meltwater forcing for the model simulations. Model results are compared with remotely-sensed and in situ ice-surface velocity measurements. Sea-ice effects are found to have a minor influence on glacier flow speed relative to that of meltwater drainage, which is clearly implicated in short-term velocity variations during the melt season. We find that threshold drainage is essential in determining the timing of these short-lived accelerations.
To explore GPs’ experiences of managing recurrent urinary tract infections (RUTIs) and their views on the use of herbal medicines for this condition.
RUTIs are an important problem commonly managed in primary care. Antibiotic prophylaxis is an effective treatment for acute infections but growing microbial resistance, adverse effects, and the lack of sustained long-term benefits mean that novel treatments are required. There are a number of promising reports of herbal medicines being used to treat RUTIs.
A total of 15 GPs (seven female; aged 34–59 years; in practice from 3 to 31 years) were purposively sampled and took part in semi-structured face-to-face and telephone interviews. Interviews were digitally recorded, transcribed, and analysed using inductive thematic analysis. Data collection and analysis proceeded iteratively to allow emerging themes to inform subsequent interviews.
Participants were aware of the disabling effect of RUTIs on women’s lives. GPs experienced significant challenges in their management of RUTIs with decisions about the provision of antibiotics being particularly complex. While some participants were open to the possibility of herbal treatment options they required more research into effectiveness and safety, better regulation of herbal practitioners, and assurance about herbal quality control and potential herb–drug interactions.
Donald (2007) showed that the adult sex ratios of wild bird populations tended to be male-biased, and that this bias was stronger in threatened species than in those of least concern. Here we show that, in 2004, the world population of the Critically Endangered Raso Lark was 65 individuals, 70% of which were male (adult sex ratio 0.70). In 2008, the population numbered approximately 175 (including juveniles) and the adult sex ratio was 0.58. Both ratios were significantly different from parity. All adult females were observed to be both paired and holding a territory. The observations therefore support Donald’s (2007) suggestion that a shortage of females can be an important constraint on the growth of threatened bird populations, a constraint that needs attention in conservation planning.
The goal of this effort was to reduce central venous catheter (CVC)-associated bloodstream infections (BSIs) in pediatric intensive care unit (ICU) patients by means of a multicenter evidence-based intervention.
An observational study was conducted in 26 freestanding children's hospitals with pediatric or cardiac ICUs that joined a Child Health Corporation of America collaborative. CVC-associated BSI protocols were implemented using a collaborative process that included catheter insertion and maintenance bundles, daily review of CVC necessity, and daily goals. The primary goal was either a 50% reduction in the CVC-associated BSI rate or a rate of 1.5 CVC-associated BSIs per 1,000 CVC-days in each ICU at the end of a 9-month improvement period. A 12-month sustain period followed the initial improvement period, with the primary goal of maintaining the improvements achieved.
The collaborative median CVC-associated BSI rate decreased from 6.3 CVC-associated BSIs per 1,000 CVC-days at the start of the collaborative to 4.3 CVC-associated BSIs per 1,000 CVC-days at the end of the collaborative. Sixty-five percent of all participants documented a decrease in their CVC-associated BSI rate. Sixty-nine CVC-associated BSIs were prevented across all teams, with an estimated cost avoidance of $2.9 million. Hospitals were able to sustain their improvements during a 12-month sustain period and prevent another 198 infections.
We conclude that our collaborative quality improvement project demonstrated that significant reduction in CVC-associated BSI rates and related costs can be realized by means of evidence-based prevention interventions, enhanced communication among caregivers, standardization of CVC insertion and maintenance processes, enhanced measurement, and empowerment of team members to enforce adherence to best practices.
The effect of long-term exposure to cigarette smoke on the height and specificity of the secondary humoral immune response to influenza was investigated in a murine model system. It was shown that if mice were pre-immunized with a sub-lethal infection of influenza virus and then exposed to cigarette smoke daily for 36 weeks, they were able to mount a secondary immune response of normal height on subsequent challenge with the homologous virus strain. The response, however, was less specific than that elicited in control mice, with high titres of cross-reacting antibody by haemagglutination-inhibition to the following strain in the same antigenic series. Recall of antibody to the previous strain in the antigenic series was not observed in either control or smoke-exposed animals. These results serve to correct an earlier discrepancy between the murine system and human studies in which the response to influenza infection in mice was depressed by prolonged exposure to cigarette smoke, whereas in man the response of smokers did not differ significantly from that of non-smokers. This apparent discrepancy had been caused by a lack of previous experience of influenza in the mice, which had therefore mounted a primary response, compared with the secondary response observed in the human studies.
This study evaluates the utility and cost effectiveness of empirical and prophylactic antibiotic treatment of leptospirosis compared with conventional management. We developed decision trees comparing empirical antibiotic treatment (within 4–7 days of symptom onset) or prophylaxis to conventional antibiotic treatment (initiated ⩾7 days post-onset). Costs were calculated using both US and Barbados pricing. Empirical treatment provided slightly lower probability of survival, while prophylactic treatment resulted in slightly higher survival rates. Antibiotic treatment initiated after 4–7 symptomatic days was ineffective in preventing serious health outcomes, but cost less with the exception of azithromycin (US pricing). Empirical treatment in Barbados cost less than conventional treatment. Prophylaxis reduced rare serious health outcomes and resulted in significant cost savings for the United States and Barbados. Prophylactic therapy for high-risk individuals or prompt diagnosis and early treatment (before 4 days of symptoms) appear to be cost-effective approaches to prevent severe complications of leptospirosis.
To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among patients presenting for hospital admission and to identify risk factors for MRSA colonization.
Surveillance cultures were performed at the time of hospital admission to identify patients colonized with S. aureus. A case-control study was performed to identify risk factors for MRSA colonization.
A tertiary-care academic medical center.
Adults presenting for hospital admission (N = 974).
S. aureus was isolated from 205 (21%) of the patients for whom cultures were performed. Methicillin-sensitive S. aureus was isolated from 179 (18.4%) of the patients, and MRSA was isolated from 26 (2.7%) of the patients. All 26 MRSA-colonized patients had been admitted to a healthcare facility in the preceding year, had at least one chronic illness, or both. In multivariate analyses comparing MRSA-colonized patients with control-patients, admission to a nursing home (odds ratio [OR], 16.5; 95% confidence interval [CI95], 1.4 to 192.1; P = .025) or a hospitalization of 5 days or longer during the preceding year (OR, 3.91; CI95, 1.1 to 13.9; P = .035) were independent predictors of MRSA colonization.
Patients colonized with MRSA admitted to this hospital likely acquired the organism during previous encounters with healthcare facilities. There was no evidence that MRSA colonization occurs commonly among low-risk individuals in this community. These data suggest that evaluation of recent healthcare exposures is essential if true community acquisition of MRSA is to be confirmed.
Currently, the microlithography industry creates large amounts of organic and aqueous wastes in the production of semiconductors. Using carbon dioxide can possibly eliminate the majority of these waste solvents as well as eliminate the image collapse problems shown with aqueous base development. We will discuss the use of carbon dioxide to replace the most solvent intensive steps of the microlithography process, spin coating, developing, and stripping. However, before CO2 can replace conventional solvents, photoresist systems must be designed and synthesized to be compatible with CO2. These photoresist systems must be soluble in liquid CO2 to insure that thin-uniform coatings can be produced by spin coating while maintaining characteristics of conventional resist systems such as low absorbance, high sensitivity, solubility contrast, good resolution, and etch resistance. Using our CO2 compatible resist system, we will demonstrate the ability of CO2 to spin coat uniform thin-films which (after exposing and PEB) can be developed using scCO2 to produce lithography features that may be stripped in CO2. Thus, revealing the enormous potential of CO2 to provide the microlithography industry an opportunity to escape its water and organic solvent dependence as it moves toward 157nm lithography.
Currently, the microlithography industry creates large amounts of organic and aqueous wastes in the production of semiconductors. Using carbon dioxide can possibly eliminate the majority of these waste solvents as well as eliminate the image collapse problems shown with aqueous base development. We will discuss the use of carbon dioxide to replace the most solvent intensive steps of the microlithography process, spin coating, developing, and stripping. However, before CO2 can replace conventional solvents, photoresist systems must be designed and synthesized to be compatible with CO2. These photoresist systems must be soluble in liquid CO2 to insure that thin-uniform coatings can be produced by spin coating while maintaining characteristics of conventional resist systems such as low absorbance, high sensitivity, solubility contrast, good resolution, and etch resistance. Using our CO2compatible resist system, we will demonstrate the ability of CO2 to spin coat uniform thin-films which (after exposing and PEB) can be developed using scCO2 to produce lithography features that may be stripped in CO2. Thus, revealing the enormous potential of CO2 to provide the microlithography industry an opportunity to escape its water and organic solvent dependence as it moves toward 157nm lithography.
Electrochemical atomic-layer epitaxy (EC-ALE) is an approach to electrodepositing thin-films of compound semiconductors. It takes advantage of underpotential deposition (UPD), deposition of a surface limited amount (a monolayer or less) of an element at a potential less negative than bulk deposition, to form a thin-film of a compound--one atomic layer at a time. Ideally, the 2-D growth mode should promote epitaxial deposition.
Many II-VI and a few III-V compounds have been formed by EC-ALE. TI-VI films such as CdSe, CdS, and CdTe have been successfully formed. In addition, deposition of III-V compounds of InAs and InSb are being explored, along with initial studies of GaAs deposition. Depositions of the I-VI systems are better understood so this report will focus on the III-V's, particularly InAs and InSb.
Building compounds an atomic layer at a time lends electrochemical-ALE to nanoscale technology. Deposited thickness ranged from a few nanometers to a few hundred. The films are typically characterized by atomic-force microscopy (AFM), X-ray diffraction (XRD), electron microprobe analysis (EPMA) and ellipsometry. InAs deposits are also characterized by infrared reflection absorption.
Rapid thermal processing has been used to grow high quality, low defect density, low mobile charge, dielectric films of oxide and nitrided oxide. Suitable annealing can lower the fixed charge and interfacial trap density present in these filmsto acceptably low levels. Both RTA and RTN were shown to improve the dielectric properties of the grown oxides. These filmsshould be strong candidates for use in high density, shallow junction, integrated circuits where a minimal time/temperature constraint is imposed on further processing after diffusion.