1,008 research outputs found

    Strategies to control the spectral properties of Au-Ni thin films

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    Gold and nickel have quite different dielectric functions. Here we use a combination of calculation and sample manufacture to assess two strategies by which thin films of these elements can be produced with a controlled range of far-field optical properties. In the first approach, control can be achieved by manipulating the density of states of metastable solid solutions, which in turn controls the dielectric function. In the second approach the optical properties of the films are controlled by varying the geometry of stacks fabricated from the constituent elements. We show that the two approaches can produce equivalent results so both are viable options in practice. Modeling is used to reveal how the structure controls the optical properties and to map out the possible color gamut. Predictions are tested with thin film samples fabricated by magnetron sputtering. © 2013 Elsevier B.V

    A Golf Programme for People with Severe and Enduring Mental Health Problems

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    This article reports a pioneering golf programme for people with severe and enduring mental health problems. Following a discussion of the problems and possibilities of golf as a form of physical activity for this group, we outline the structure, organisation, and ethos of the golf programme. Through an analysis of qualitative case study data collected during the programme, we discuss the response to the programme from service users and mental health professionals. We conclude by highlighting aspects of the programme which were critical to its success and offering suggestions for further initiatives in this area

    How did the latest increase in fees in England affect student enrolment and inequality?

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    This paper presents a first analysis of the increase of undergraduate tuition fees to £9,000 (€11.000) in English higher education in 2012. I use a semi-experimental research design to estimate the effect of the reforms, based on student enrolment data drawn from the Higher Education Statistics Agency (HESA). Taking into account possible anticipation effects of the fee increase, I find that enrolment declined by 15 % in the treated groups as a result of the tuition fee increase. This number is almost three times higher than what previous studies have found, and may represent a serious long term cost for the English economy. The decline in enrolments is particularly pronounced for students in older age groups and students from the service class and the middle class. No effect is visible for students from the working class, indicating that the reforms did not lead to a much-feared increase in class bias in higher education enrolment. The reforms also seem not to have exacerbated ethnic inequality in higher education, as all ethnic groups were negatively affected by the reforms. These results are consistent with earlier research in the United States and the United Kingdom, although they expand our understanding of student price responsiveness in other important ways. The paper argues that younger and older students face different costs and benefits. Older students may be less certain about their benefits, and therefore be more sensitive towards price increases. The strong decrease in mature learners may require a policy response, taking into account these differing incentives

    Validation of the diabetes, hypertension and hyperlipidemia (DHL) knowledge instrument in Malaysia

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    BACKGROUND: Patient's knowledge on diabetes, hypertension and hyperlipidaemia and its medications can be used as one of the outcome measures to assess the effectiveness of educational intervention. To date, no such instrument has been validated in Malaysia. Therefore, the aim of this study was to evaluate the validity and reliability of the Diabetes, Hypertension and Hyperlipidemia (DHL) knowledge instrument for assessing the knowledge of patients with type 2 diabetes in Malaysia. METHODS: A 28-item instrument which comprised of 5 domains: diabetes, hypertension, hyperlipidemia, medications and general issues was designed and tested. One point was given for every correct answer, whilst zero was given for incorrect answers. Scores ranged from 0 to 28, which were then converted into percentage. This was administered to 77 patients with type 2 diabetes in a tertiary hospital, who were on medication(s) for diabetes and who could understand English (patient group), and to 40 pharmacists (professional group). The DHL knowledge instrument was administered again to the patient group after one month. Excluded were patients less than 18 years old. RESULTS: Flesch reading ease was 60, which is satisfactory, while the mean difficulty factor(SD) was 0.74(0.21), indicating that DHL knowledge instrument was moderately easy. Internal consistency of the instrument was good, with Cronbach's alpha = 0.791. The test-retest scores showed no significant difference for 26 out of the 28 items, indicating that the questionnaire has achieved stable reliability. The overall mean(SD) knowledge scores was significantly different between the patient and professional groups 74.35(14.88) versus 93.84(6.47), p < 0.001. This means that the DHL knowledge instrument could differentiate the knowledge levels of participants. The DHL knowledge instrument shows similar psychometric properties as other validated questionnaires. CONCLUSIONS: The DHL knowledge instrument shows good promise to be adopted as an instrument for assessing diabetic patients' knowledge concerning their disease conditions and medications in Malaysia

    Microencapsulated foods as a functional delivery vehicle for omega-3 fatty acids: a pilot study

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    It is well established that the ingestion of the omega-3 (N3) fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) positively benefit a variety of health indices. Despite these benefits the actual intake of fish derived N3 is relatively small in the United States. The primary aim of our study was to examine a technology capable of delivering omega-3 fatty acids in common foods via microencapsulation (MicroN3) in young, healthy, active participants who are at low risk for cardiovascular disease. Accordingly, we randomized 20 participants (25.4 ± 6.2 y; 73.4 ± 5.1 kg) to receive the double blind delivery of a placebo-matched breakfast meal (~2093 kJ) containing MicroN3 (450–550 mg EPA/DHA) during a 2-week pilot trial. Overall, we observed no differences in overall dietary macronutrient intake other than the N3 delivery during our treatment regimen. Post-test ANOVA analysis showed a significant elevation in mean (SE) plasma DHA (91.18 ± 9.3 vs. 125.58 ± 11.3 umol/L; P < 0.05) and a reduction in triacylglycerols (89.89 ± 12.8 vs. 80.78 ± 10.4 mg/dL; P < 0.05) accompanying the MicroN3 treatment that was significantly different from placebo (P < 0.05). In post study interviews, participants reported that the ingested food was well-tolerated, contained no fish taste, odor or gastrointestinal distress accompanying treatment. The use of MicroN3 foods provides a novel delivery system for the delivery of essential fatty acids. Our study demonstrates that MicroN3 foods promote the absorption of essential N3, demonstrate bioactivity within 2 weeks of ingestion and are well tolerated in young, active participants who are at low risk for cardiovascular disease

    Pneumonia care and the nursing home: a qualitative descriptive study of resident and family member perspectives

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    BACKGROUND: Nursing home residents are frequently sent to hospital for diagnostic tests or to receive acute health care services. These transfers are both costly and for some, associated with increased risks. Although improved technology allows long-term care facilities to deliver more complex health care on site, if this is to become a trend then residents and family members must see the value of such care. This qualitative study examined resident and family member perspectives on in situ care for pneumonia. METHODS: A qualitative descriptive study design was used. Participants were residents and family members of residents treated for pneumonia drawn from a larger randomized controlled trial of a clinical pathway to manage nursing home-acquired pneumonia on-site. A total of 14 in-depth interviews were conducted. Interview data were analyzed using the editing style, described by Miller and Crabtree, to identify key themes. RESULTS: Both residents and family members preferred that pneumonia be treated in the nursing home, where possible. They both felt that caring and attention are key aspects of care which are more easily accessible in the nursing home setting. However, residents felt that staff or doctors should make the decision whether to hospitalize them, whereas family members wanted to be consulted or involved in the decision-making process. CONCLUSION: These findings suggest that interventions to reduce hospitalization of nursing home residents with pneumonia are consistent with resident and family member preferences

    Sphingomyelin phosphodiesterase-1 (SMPD1) coding variants do not contribute to low levels of high-density lipoprotein cholesterol

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    <p>Abstract</p> <p>Background</p> <p>Niemann-Pick disease type A and B is caused by a deficiency of acid sphingomyelinase due to mutations in the sphingomyelin phosphodiesterase-1 (<it>SMPD1</it>) gene. In Niemann-Pick patients, <it>SMPD1 </it>gene defects are reported to be associated with a severe reduction in plasma high-density lipoprotein (HDL) cholesterol.</p> <p>Methods</p> <p>Two common coding polymorphisms in the <it>SMPD1 </it>gene, the G1522A (G508R) and a hexanucleotide repeat sequence within the signal peptide region, were investigated in 118 unrelated subjects of French Canadian descent with low plasma levels of HDL-cholesterol (< 5<sup>th </sup>percentile for age and gender-matched subjects). Control subjects (n = 230) had an HDL-cholesterol level > the 25<sup>th </sup>percentile.</p> <p>Results</p> <p>For G1522A the frequency of the G and A alleles were 75.2% and 24.8% respectively in controls, compared to 78.6% and 21.4% in subjects with low HDL-cholesterol (<it>p </it>= 0.317). The frequency of 6 and 7 hexanucleotide repeats was 46.2% and 46.6% respectively in controls, compared to 45.6% and 49.1% in subjects with low HDL-cholesterol (<it>p </it>= 0.619). Ten different haplotypes were observed in cases and controls. Overall haplotype frequencies in cases and controls were not significantly different.</p> <p>Conclusion</p> <p>These results suggest that the two common coding variants at the <it>SMPD1 </it>gene locus are not associated with low HDL-cholesterol levels in the French Canadian population.</p

    Effectiveness of ophthalmic solution preservatives: a comparison of latanoprost with 0.02% benzalkonium chloride and travoprost with the sofZia preservative system

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    <p>Abstract</p> <p>Background</p> <p>Although in vitro and in vivo laboratory studies have suggested that benzalkonium chloride (BAK) in topical ophthalmic solutions may be detrimental to corneal epithelial cells, multiple short- and long-term clinical studies have provided evidence supporting the safety of BAK. Despite the conflicting evidence, BAK is the most commonly used preservative in ophthalmic products largely due to its proven antimicrobial efficacy. This study was designed to characterize the antimicrobial performance of two commonly used topical ocular hypotensive agents that employ different preservative systems: latanoprost 0.005% with 0.02% BAK and travoprost 0.004% with sofZia, a proprietary ionic buffer system.</p> <p>Methods</p> <p>Each product was tested for antimicrobial effectiveness by <it>European Pharmacopoeia </it>A (EP-A) standards, the most stringent standards of the three major compendia, which specify two early sampling time points (6 and 24 hours) not required by the <it>United States Pharmacopeia </it>or <it>Japanese Pharmacopoeia</it>. Aliquots were inoculated with between 10<sup>5 </sup>and 10<sup>6 </sup>colony-forming units of the test organisms: <it>Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans </it>and <it>Aspergillus brasiliensis</it>. Sampling and enumeration were conducted at protocol-defined time points through 28 days.</p> <p>Results</p> <p>BAK-containing latanoprost met EP-A criteria by immediately reducing all bacterial challenge organisms to the test sensitivity and fungal challenges within the first six hours while the preservative activity of travoprost with sofZia did not. Complete bacterial reduction by travoprost with sofZia was not shown until seven days into the test, and fungal reduction never exceeded the requisite 2 logs during the 28-day test. Travoprost with sofZia also did not meet EP-B criteria due to its limited effectiveness against <it>Staphylococcus aureus</it>. Both products satisfied United States and Japanese pharmacopoeial criteria.</p> <p>Conclusions</p> <p>Latanoprost with 0.02% BAK exhibited more effective microbial protection than travoprost with sofZia using rates of microbial reduction, time to no recovery for all challenges and evaluation against EP-A criteria as measures. The rapid and complete reduction of all microbial challenges demonstrates that antimicrobial activity of latanoprost with 0.02% BAK exceeds that of travoprost with sofZia preservative system in these products and provides a more protective environment in the event of contamination and subsequent exposure to microorganisms during use.</p

    Much Ado About the TPP’s Effect on Pharmaceuticals

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    Ocular antigens are sequestered behind the blood-retina barrier and the ocular environment protects ocular tissues from autoimmune attack. The signals required to activate autoreactive T cells and allow them to cause disease in the eye remain in part unclear. In particular, the consequences of peripheral presentation of ocular antigens are not fully understood. We examined peripheral expression and presentation of ocular neo-self-antigen in transgenic mice expressing hen egg lysozyme (HEL) under a retina-specific promoter. High levels of HEL were expressed in the eye compared to low expression throughout the lymphoid system. Adoptively transferred naïve HEL-specific CD4+ T cells proliferated in the eye draining lymph nodes, but did not induce uveitis. By contrast, systemic infection with a murine cytomegalovirus (MCMV) engineered to express HEL induced extensive proliferation of transferred naïve CD4+ T cells, and significant uveoretinitis. In this model, wild-type MCMV, lacking HEL, did not induce overt uveitis, suggesting that disease is mediated by antigen-specific peripherally activated CD4+ T cells that infiltrate the retina. Our results demonstrate that retinal antigen is presented to T cells in the periphery under physiological conditions. However, when the same antigen is presented during viral infection, antigen-specific T cells access the retina and autoimmune uveitis ensues

    From descriptive to predictive distribution models: a working example with Iberian amphibians and reptiles

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    BACKGROUND: Aim of the study was to identify the conditions under which spatial-environmental models can be used for the improved understanding of species distributions, under the explicit criterion of model predictive performance. I constructed distribution models for 17 amphibian and 21 reptile species in Portugal from atlas data and 13 selected ecological variables with stepwise logistic regression and a geographic information system. Models constructed for Portugal were extrapolated over Spain and tested against range maps and atlas data. RESULTS: Descriptive model precision ranged from 'fair' to 'very good' for 12 species showing a range border inside Portugal ('edge species', kappa (k) 0.35–0.89, average 0.57) and was at best 'moderate' for 26 species with a countrywide Portuguese distribution ('non-edge species', k = 0.03–0.54, average 0.29). The accuracy of the prediction for Spain was significantly related to the precision of the descriptive model for the group of edge species and not for the countrywide species. In the latter group data were consistently better captured with the single variable search-effort than by the panel of environmental data. CONCLUSION: Atlas data in presence-absence format are often inadequate to model the distribution of species if the considered area does not include part of the range border. Conversely, distribution models for edge-species, especially those displaying high precision, may help in the correct identification of parameters underlying the species range and assist with the informed choice of conservation measures
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