760 research outputs found

    Heat-rejection windows for telescopes

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    Heat-rejection telescope windows reflect incident solar energy outside the hydrogen-alpha line while processing a peak transmission exceeding fifty percent at 6563 angstrom units. The windows also function as secondary blocking filters to the telescope's Fabry-Perot filter

    Extraterrestrial CPR and Its Applications in Terrestrial Medicine

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    Cardiopulmonary resuscitation (CPR) is a well-established part of basic life support (BLS), saving countless lives since its first development in the 1960s. Recently, work has been undertaken to develop methods of basic and advanced life support (ALS) in microgravity and hypogravity. Although the likelihood of a dangerous cardiac event occurring during space mission is rare, the possibility exists. The selection process for space missions nowadays considers individuals at ages and with health standards that would have precluded their selection in the past. The advent of space tourism may even enhance this possibility. This chapter presents a synthesis of the results obtained in studies conducted at the MicroG-PUCRS, Brazil, examining extraterrestrial CPR during ground-based microgravity and hypogravity simulations and during parabolic flights and sustained microgravity. It outlines the extraterrestrial BLS guidelines for both low-orbit and deep-space missions. The former are based on a combination of factors, unique for the environment of space. In a setting like this, increased physiological stress due to gravitational adaptation and the isolated nature of the environmental demands can affect the outcome of resuscitation procedure

    The economic value of an improved malaria treatment programme in Zambia: results from a contingent valuation survey

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    BACKGROUND: Zambia is facing a double crisis of increasing malaria burden and dwindling capacity to deal with the endemic malaria burden. The pursuit of sustainable but equity mechanisms for financing malaria programmes is a subject of crucial policy discussion. This requires that comprehensive accounting of the economic impact of the various malaria programmes. Information on the economic value of programmes is essential in soliciting appropriate funding allocations for malaria control. AIMS AND OBJECTIVES: This paper specifically seeks to elicit a measure of the economic benefits of an improved malaria treatment programme in Zambia. The paper also studies the equity implications in malaria treatment given that demand or malaria treatment is determined by household socio-economic status. METHODS: A contingent valuation survey of about 300 Zambian households was conducted in four districts. Willingness-to-pay (WTP) was elicited for an improved treatment programme for malaria in order to generate a measure of the economic benefits of the programme. The payment card method was used in eliciting WTP bids. FINDINGS: The study reports that malaria treatment has significant economic benefits to society. The total economic benefits of an improved treatment programme were estimated at an equivalent of US$ 77 million per annum, representing about 1.8% of Zambia's GDP. The study also reports the theoretically anticipated association between WTP and several socio-economic factors. Our income elasticity of demand is positive and similar in magnitude to estimates reported in similar studies. Finally, from an equity standpoint, the constraints imposed by income and socio-economic status are discussed

    How are individual-level social capital and poverty associated with health equity? A study from two Chinese cities

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    <p>Abstract</p> <p>Background</p> <p>A growing body of literature has demonstrated that higher social capital is associated with improved health conditions. However, some research indicated that the association between social capital and health was substantially attenuated after adjustment for material deprivation. Studies exploring the association between poverty, social capital and health still have some serious limitations. In China, health equity studies focusing on urban poor are scarce. The purpose of this study is therefore to examine how poverty and individual-level social capital in urban China are associated with health equity.</p> <p>Methods</p> <p>Our study is based on a household study sample consisting of 1605 participants in two Chinese cities. For all participants, data on personal characteristics, health status, health care utilisation and social capital were collected. Factor analysis was performed to extract social capital factors. Dichotomised social capital factors were used for logistic regression models. A synergy index (if it is above 1, we can know the existence of the co-operative effect) was computed to examine the interaction effect between lack of social capital and poverty.</p> <p>Results</p> <p>Results indicated the poor had an obviously higher probability of belonging to the low individual-level social capital group in all the five dimensions, with the adjusted odds ratios ranging from 1.42 to 2.12. When the other variables were controlled for in the total sample, neighbourhood cohesion (NC), and reciprocity and social support (RSS) were statistically associated with poor self-rated health (NC: OR = 1.40; RSS: OR = 1.34). However, for the non-poor sub-sample, no social capital variable was a statistically significant predictor. The synergy index between low individual-level NC and poverty, and between low individual-level RSS and poverty were 1.22 and 1.28, respectively, indicating an aggravating effect between them.</p> <p>Conclusion</p> <p>In this study, we have shown that the interaction effect between poverty and lack of social capital (NC and RSS) was a good predictor of poor SRH in urban China. Improving NC and RSS may be helpful in reducing health inequity; however, poverty reduction is more important and therefore should be implemented at the same time. Policies that attempt to improve health equity via social capital, but neglect poverty intervention, would be counter-productive.</p

    Non-pharmaceutical prevention of hip fractures – a cost-effectiveness analysis of a community-based elderly safety promotion program in Sweden

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    <p>Abstract</p> <p>Background</p> <p>Elderly injuries are a recognized public health concern and are due to two factors; osteoporosis and accidental falls. Several osteoporosis pharmaceuticals are considered cost-effective, but intervention programs aiming at preventing falls should also be subjected to economic evaluations. This study presents a cost-effectiveness analysis of a community-based elderly safety promotion program.</p> <p>Methods</p> <p>A five-year elderly safety promotion program combining environmental structural changes with individually based measures was implemented in a community in the metropolitan area of Stockholm, Sweden. The community had around 5,500 inhabitants aged 65+ years and a first hip fracture incidence of 10.7 per 1,000 in pre-intervention years 1990–1995. The intervention outcome was measured as avoided hip fractures, obtained from a register-based quasi-experimental longitudinal analysis with several control areas. The long-term consequences in societal costs and health effects due to the avoided hip fractures, conservatively assumed to be avoided for one year, were estimated with a Markov model based on Swedish data. The analysis holds the societal perspective and conforms to recommendations for pharmaceutical cost-effectiveness analyses.</p> <p>Results</p> <p>Total societal intervention costs amounted to 6.45 million SEK (in Swedish krona 2004; 1 Euro = 9.13 SEK). The number of avoided hip fractures during the six-year post-intervention period was estimated to 14 (0.44 per 1,000 person-years). The Markov model estimated a difference in societal costs between an individual that experiences a first year hip fracture and an individual that avoids a first year hip fracture ranging from 280,000 to 550,000 SEK, and between 1.1 and 3.2 QALYs (quality-adjusted life-years, discounted 3%), for males and females aged 65–79 years and 80+ years. The cost-effectiveness analysis resulted in zero net costs and a gain of 35 QALYs, and the do-nothing alternative was thus dominated.</p> <p>Conclusion</p> <p>The community-based elderly safety promotion program aiming at preventing accidental falls seems as cost-effective as osteoporosis pharmaceuticals.</p

    Hospital productivity and the Norwegian ownership reform – A Nordic comparative study

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    In a period where decentralisation seemed to be the prominent trend, Norway in 2002 chose to re-centralise the hospital sector. The reform had three main aims; cost control, efficiency and reduced waiting times. This study investigates whether the hospital reform has improved hospital productivity using the other four major Nordic countries as controls. Hospital productivity measures are obtained using data envelopment analysis (DEA) on a comparable dataset of 728 Nordic hospitals in the period 1999 to 2004. First a common reference frontier is established for the four countries, enveloping the technologies of each of the countries and years. Bootstrapping techniques are applied to the obtained productivity estimates to assess uncertainty and correct for bias. Second, these are regressed on a set of explanatory variables in order to separate the effect of the hospital reform from the effects of other structural, financial and organizational variables. A fixed hospital effect model is used, as random effects and OLS specifications are rejected. Robustness is examined through alternate model specifications, including stochastic frontier analysis (SFA). The SFA approach in performed using the Battese & Coelli (1995) one stage procedure where the inefficiency term is estimated as a function of the set of explanatory variables used in the second stage in the DEA approach. Results indicate that the hospital reform in Norway seems to have improved the level of productivity in the magnitude of approximately 4 % or more. While there are small or contradictory estimates of the effects of case mix and activity based financing, the length of stay is clearly negatively associated with estimated productivity. Results are robust to choice of efficiency estimation technique and various definition of when the reform effect takes place.Efficiency; productivity; DEA; SFA; hospitals

    “Vi kanske skulle säga att vi ger behandling i grupp?” Verksamhetschefers erfarenheter av distriktssköterskeledd patientundervisning i grupp på vårdcentraler i södra Sverige

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    Hälsofrämjande arbete är en del av distriktssköterskans arbetsområde och ett sätt att förebygga framtida ohälsa hos befolkningen. Ett effektivt sätt att utnyttja befintliga resurser vid hälsofrämjande arbete är att bedriva patientundervisning i grupp. Syftet med studien var att undersöka verksamhetschefers erfarenheter av distriktssköterskeledd patientundervisning i grupp på vårdcentral i södra Sverige. Studien genomfördes med mixad metod där 22 verksamhetschefer intervjuades i två faser och där såväl kvantitativ som kvalitativ dataanalys använts. Resultatet visade att det finns vårdcentraler i södra Sverige där grupper förekommer samt att förutsättningarna för förekomsten enligt verksamhetschefernas erfarenhet är beroende av en rad faktorer på flera olika nivåer såväl i som utanför den egna verksamheten. Slutligen konstaterades att det mest grundläggande för att bedriva distriktssköterskeledd patientundervisning i grupp är organisationens prioriteringar samt motiverade patienter

    Short- and long-term effects of anti-CD20 treatment on B cell ontogeny in bone marrow of patients with rheumatoid arthritis

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    It has been known for a long time that B cells play a role in rheumatoid arthritis (RA). By production of autoantibodies, presentation of auto-antigens and by producing cytokines B cells may contribute to the pathogenesis of RA. In recent years it has been shown that anti-B cell therapy is a powerful tool in the treatment of RA. The aim of this thesis was to a) investigate the effect on B cell ontogeny following B cell depletion therapy, b) during B cell depletion therapy evaluate serological and humoral immune responses and finally, c) try to establish a connection between Epstein-Barr virus (EBV) infection, CD25+ B cells and outcome of B cell deletion therapy. In paper I we could show that in bone marrow of RA patients following anti-CD20 treatment with rituximab (RTX) IgD expressing naïve cells are depleted whereas immature and memory B cells where still detectable. However, the long-term effects clearly showed a reduction of memory B cells in bone marrow. The examination of rheumatoid factor (RF) production revealed that RFs decline short after treatment but returned to baseline levels concurrently with the IgD expressing B cells when patients where subjected to an additional course. In paper II the cellular and humoral immune responses were evaluated by immunisation of RA patients before or during RTX treatment with a protein vaccine against influenza and a pneumococcal polysaccharide vaccine. The results suggest that both cellular and humoral immune responses are affected in patients receiving RTX treatment and we therefore suggest that immunisation should be performed before RTX treatment. In paper III we investigate the effects of EBV on selected B cell subsets and how infection may affect the clinical response to RTX treatment. The phenotypical study showed that B cells are more mature in EBV infected patients and the CD25+ B cell subset was more mature as compared to the CD25- B cell population. The evaluation of clinical response to RTX treatment with regard to B cell subsets showed that non-responding EBV+ patients had a significantly larger CD25+ plasma cell population. When investigating the effects of EBV stimulation in vitro we found that the CD25+ B cell population developed into antibody-producing cells to a higher extent than did the corresponding CD25- B cell population. The results of our studies indicate that that B cells play an essential role in the pathogenesis of RA. During RTX treatment we suggest that the IgD expressing population may harbour the autoantibody producing B cells. We also claim that that there are subsets of B cells (i.e. CD25+ B cells) that may have significant impact on the pathogenesis of RA, and the clinical outcome following RTX treatment

    Discovery of Oxygen Carriers by Mining a First-Principle Database

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    Chemical looping is an innovative technique that relies, to a large extent, on the possibility of finding new oxygen carriers. Until now, these materials have primarily been identified via experimental techniques and therefrom derived insights. However, this is both costly and time-consuming. To speed-up this process, we have applied a computational screening approach based on energetic data retrieved from the Open Quantum Materials Database. In particular, we have considered combinations of all mono-, bi-, and trimetallic alloys and mixed oxides with up to three distinctive phases. Here, we specifically focus on a technique referred to as chemical looping oxygen uncoupling, which is especially suitable for solid fuels, e.g., combustion of biomass for negative CO2 emissions. The formation energies obtained for the materials of interest were used to identify phase transitions that are likely to occur under conditions relevant for chemical looping oxygen uncoupling. Given these criteria, the initial list of 300000 materials is reduced by a factor of 20, and after filtering out rare, radioactive, toxic, or harmful elements only 1000 remain. When considering the abundance of elements in the ranking criteria, most of the highest ranking phases include Cu, Mn, and Fe. This adds credibility to the procedure, as many viable oxygen carriers for chemical looping oxygen uncoupling that have been studied experimentally contain these elements. While Cr-based materials have not been widely explored for this application, our study suggests that this might be worthwhile since these occur more frequently than Fe. Other elements that would be interesting as additional components include Ba, K, Na, Al, and Si
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