255 research outputs found
The Effectiveness of Teleglaucoma versus In-patient Examination. Assessment: Systematic Review, Meta-Analysis, and Cost-Effectiveness Analysis
Teleglaucoma is a screening device that remotely detects glaucoma cases at earlier stages using electronically-transferred stereoscopic digital imaging. Thus, patient wait and travel times are reduced, as well as, patient load in ophthalmic clinics. The purpose is to synthesize literature to evaluate teleglaucoma: its diagnostic accuracy, the healthcare system benefits, and its cost-effectiveness. A systematic review was conducted with published and unpublished studies. A meta-analysis was conducted to provide estimates of diagnostic accuracy, diagnostic odds ratio, and the relative percentage of glaucoma cases detected. Using Markov Modelling, a cost-effectiveness analysis was conducted. Of 11237 studies reviewed, 45 were included. Teleglaucoma was more specific and less sensitive than in-person examination. The pooled estimates of sensitivity was 0.832 [95% CI 0.770, 0.881] and specificity was 0.790 [95% CI 0.668, 0.876]. The ICER calculated for teleglaucoma was $27,460/QALY. In conclusion, teleglaucoma was found to be more cost-effective than in-person examination in rural areas
The Power of Jets: New Clues from Radio Circular Polarization and X-rays
Jets are ubiquitous in accreting black holes. Often ignored, they may be a
major contributor to the emitted spectral energy distribution for sub-Eddington
black holes. For example, recent observations of radio-to-X-ray correlations
and broad band spectra of X-ray binaries in the low/hard state can be explained
by a significant synchrotron contribution from jets also to their IR-to-X-ray
spectrum as proposed by Markoff, Falcke, Fender 2001. This model can also
explain state-transitions from low/hard to high/soft states. Relativistic
beaming of the jet X-ray emission could lead to the appearance of seemingly
Super-Eddington X-rays sources in other galaxies. We show that a simple
population synthesis model of X-ray binaries with relativistic beaming can well
explain the currently found distribution of off-nucleus X-ray point sources in
nearby galaxies. Specifically we suggest that the so-called ultra-luminous
X-ray sources (ULXs, also IXOs) could well be relativistically beamed
microblazars. The same model that can be used to explain X-ray binaries also
fits Low-Luminosity AGN (LLAGN) and especially Sgr A* in the Galactic Center.
The recent detection of significant circular polarization in AGN radio cores,
ranging from bright quasars down to low-luminosity AGN like M81*, Sgr A* and
even X-ray binaries, now places additional new constraints on the matter
contents of such jets. The emerging picture are powerful jets with a mix of hot
and cold matter, a net magnetic flux, and a stable magnetic north pole.Comment: to appear in: ``Lighthouses of the Universe'', Springer Verlag, ESO
Astrophysics Symposia, Eds: R.Sunyaev, M.Gilfanov, E.Churazov, LaTex, 8
pages, 5 figures, also available at
http://www.mpifr-bonn.mpg.de/staff/hfalcke/publications.html#lighthouse
Simultaneous multiwavelength observations of V404 Cygni during its 2015 June outburst decay strengthen the case for an extremely energetic jet-base
We present results of multiband optical photometry of the black hole X-ray
binary system V404 Cygni obtained using Wheaton College Observatory's 0.3m
telescope, along with strictly simultaneous INTEGRAL and Swift observations
during 2015 June 25.15--26.33 UT, and 2015 June 27.10--27.34 UT. These
observations were made during the 2015 June outburst of the source when it was
going through an epoch of violent activity in all wavelengths ranging from
radio to -rays. The multiwavelength variability timescale favors a
compact emission region, most likely originating in a jet outflow, for both
observing epochs presented in this work. The simultaneous INTEGRAL/Imager on
Board the Integral Satellite (IBIS) 20--40 keV light curve obtained during the
June 27 observing run correlates very strongly with the optical light curve,
with no detectable delay between the optical bands as well as between the
optical and hard X-rays. The average slope of the dereddened spectral energy
distribution was roughly flat between the - and -bands during the June
27 run, even though the optical and X-ray flux varied by 25 during
the run, ruling out an irradiation origin for the optical and suggesting that
the optically thick to optically thin jet synchrotron break during the
observations was at a frequency larger than that of -band, which is quite
extreme for X-ray binaries. These observations suggest that the optical
emission originated very close to the base of the jet. A strong H
emission line, probably originating in a quasi-spherical nebula around the
source, also contributes significantly in the -band. Our data, in
conjunction with contemporaneous data at other wavelengths presented by other
groups, strongly suggest that the jet-base was extremely compact and energetic
during this phase of the outburst.Comment: 15 pages, 2 tables, 5 figures. Accepted for publication in Ap
Infrared interferometry to spatially and spectrally resolve jets in X-ray binaries
Infrared interferometry is a new frontier for precision ground based
observing, with new instrumentation achieving milliarcsecond (mas) spatial
resolutions for faint sources, along with astrometry on the order of 10
microarcseconds. This technique has already led to breakthroughs in the
observations of the supermassive black hole at the Galactic centre and its
orbiting stars, AGN, and exo-planets, and can be employed for studying X-ray
binaries (XRBs), microquasars in particular. Beyond constraining the orbital
parameters of the system using the centroid wobble and spatially resolving jet
discrete ejections on mas scales, we also propose a novel method to discern
between the various components contributing to the infrared bands: accretion
disk, jets and companion star. We demonstrate that the GRAVITY instrument on
the Very Large Telescope Interferometer (VLTI) should be able to detect a
centroid shift in a number of sources, opening a new avenue of exploration for
the myriad of transients expected to be discovered in the coming decade of
radio all-sky surveys. We also present the first proof-of-concept GRAVITY
observation of a low-mass X-ray binary transient, MAXI J1820+070, to search for
extended jets on mas scales. We place the tightest constraints yet via direct
imaging on the size of the infrared emitting region of the compact jet in a
hard state XRB.Comment: 12 Pages, 3 figures, accepted for publication in MNRA
Erratum to: Sex and Gender Equity in Research: rationale for the SAGER guidelines and recommended use
n/
Application of gas diffusion electrodes in bioeconomy: An update
The transition of today's fossil fuel based chemical industry toward sustainable production requires improvement of established production processes as well as development of new sustainable and bio-based synthesis routes within a circular economy. Thereby, the combination of electrochemical and biotechnological advantages in such routes represents one important keystone. For the electrochemical generation of reactants from gaseous substrates such as O2 or CO2, gas diffusion electrodes (GDE) represent the electrodes of choice since they overcome solubility-based mass transport limitations. Within this article, we illustrate the architecture, function principle and fabrication of GDE. We highlight the application of GDE for conversion of CO2 using abiotic catalysts for subsequent biosynthesis as well as the application of microbial catalysts at GDE for CO2 conversion. The reduction of oxygen at GDE is summarized for the application of oxygen depolarized cathodes in microbial fuel cells and generation of H2O2 to drive enzymatic reactions. Finally, engineering aspects such as scale-up and the modeling of GDE-based processes are described. This review presents an update on the application of GDE in bio-based production systems and emphasizes their large potential for sustainable development of new pathways in bioeconomy
The Effectiveness of Teleglaucoma versus In-Patient Examination for Glaucoma Screening: A Systematic Review and Meta-Analysis
BACKGROUND: Glaucoma is the leading cause of irreversible visual impairment in the world affecting 60.5 million people worldwide in 2010, which is expected to increase to approximately 79.6 million by 2020. Therefore, glaucoma screening is important to detect, diagnose, and treat patients at the earlier stages to prevent disease progression and vision loss. Teleglaucoma uses stereoscopic digital imaging to take ocular images, which are transmitted electronically to an ocular specialist. The purpose is to synthesize literature to evaluate teleglaucoma, its diagnostic accuracy, healthcare system benefits, and cost-effectiveness.
METHODS: A systematic search was conducted to help locate published and unpublished studies. Studies which evaluate teleglaucoma as a screening device for glaucoma were included. A meta-analysis was conducted to provide estimates of diagnostic accuracy, diagnostic odds ratio, and the relative percentage of glaucoma cases detected. The improvements to healthcare service quality and cost data were assessed.
RESULTS: Of 11237 studies reviewed, 45 were included. Our results indicated that, teleglaucoma is more specific and less sensitive than in-person examination. The pooled estimates of sensitivity was 0.832 [95% CI 0.770, 0.881] and specificity was 0.790 [95% CI 0.668, 0.876]. The relative odds of a positive screen test in glaucoma cases are 18.7 times more likely than a negative screen test in a non-glaucoma cases. Additionally, the mean cost for every case of glaucoma detected was 922.77 US.
CONCLUSION: Teleglaucoma can accurately discriminate between screen test results with greater odds for positive cases. It detects more cases of glaucoma than in-person examination. Both patients and the healthcare systems benefit from early detection, reduction in wait and travel times, increased specialist referral rates, and cost savings. Teleglaucoma is an effective screening tool for glaucoma specifically for remote and under-services communities
Reliability and validity of the center for epidemiologic studies-depression scale in screening for depression among HIV-infected and -uninfected pregnant women attending antenatal services in northern Uganda: a cross-sectional study.
BACKGROUND: There are limited data on the prevalence and approaches to screening for depression among pregnant women living in resource poor settings with high HIV burden. METHODS: We studied the reliability and accuracy of the Center for Epidemiologic Studies Depression (CES-D) scale in 123 (36 HIV-infected and 87 -uninfected) pregnant women receiving antenatal care at Gulu Regional Referral Hospital, Uganda. CES-D scores were compared to results from the psychiatrist-administered Mini-International Neuropsychiatric Interview (MINI) for current major depressive disorder (MDD), a "gold standard" for assessing depression. We employed measures of internal consistency (Cronbach's alpha), and criterion validity [Area Under the Receiver Operating Characteristic Curve (AUROC), sensitivity (Se), specificity (Sp), and positive predictive value (PPV)] to evaluate the reliability and validity of the CES-D scale. RESULTS: 35.8% of respondents were currently experiencing an MDD, as defined from outputs of the MINI-depression module. The CES-D had high internal consistency (Cronbach's alpha = 0.92) and good discriminatory ability in detecting MINI-defined current MDDs (AUROC = 0.82). The optimum CES-D cutoff score for the identification of probable MDD was between 16 and 17. A CES-D cutoff score of 17, corresponding to Se, Sp, and PPV values of 72.7%, 78.5%, and 76.5%, is proposed for adoption in this population and performs well for HIV-infected and -uninfected women. After adjusting for baseline differences between the HIV subgroups (maternal age and marital status), HIV-infected pregnant women scored 6.2 points higher on the CES-D than HIV-uninfected women (p = 0.032). CONCLUSIONS: The CES-D is a suitable instrument for screening for probable major depression among pregnant women of mixed HIV status attending antenatal services in northern Uganda
Smart Panking : uma aplicação para estacionamento em cidades inteligentes
The world is experiencing two major transformations: the number of people living in urban areas surpassing the number of people in rural areas and a technological revolution changing the lives of billions of people. With more people living in cities, the problems they face are intensified and the response to these problems increasingly involves the use of a lot of technology, from which emerges the concept of Smart City. In order to deal with one of the most critical problems of cities, urban mobility, this work seeks to understand its causes and what interventions could be undertaken. One of the most prominent problems that impacts the urban mobility is the high number of vehicles circulating in cities and one of the challenges is to manage this fleet of vehicles in order to reduce congestion, facilitating mobility and consequently reducing the amount of exhaust gases in the atmosphere. Since one of the causes of this problem is the time spent by drivers looking for parking spaces, one solution is to minimize it. For this purpose a Systematic Literature Review of primary studies that were inserted in this context was carried out and through a Product Research in the Market, followed by the application of a questionnaire to stakeholders, relevant characteristics were extracted for the development of a solution for this scenario. Therefore, the objective of this work was to create a tool that intelligently optimizes the process of supply and demand of parking spots, considering the growing number of vehicles and the limited space of cities as a contribution to the development of Smart Cities.O mundo está vivenciando duas grandes transformações: o número de pessoas vivendo em zonas urbanas ultrapassando o número de pessoas em zonas rurais e uma revolução tecnológica mudando a vida de bilhões de pessoas. Com mais pessoas vivendo nas cidades, os problemas que elas enfrentam são intensificados e a resposta a esses problemas envolve cada vez mais o emprego de muita tecnologia, de onde emerge o conceito de Cidade Inteligente. Com o intuito de lidar com um dos problemas mais crucias das cidades, a mobilidade urbana, este trabalho procurou levantar as suas causas e quais intervenções poderiam ser realizadas. Um dos problemas mais proeminentes que gera impacto na mobilidade urbana é o crescimento da quantidade de veÃculos circulando nas cidades e um dos desafios é gerenciar esta frota de veÃculos buscando diminuir o congestionamento, facilitando a mobilidade e consequentemente reduzindo a quantidade de gases expelidos na atmosfera. Uma vez que uma das causas deste problema é o tempo gasto pelos motoristas na procura por vagas para estacionar, uma solução é minimizar esta causa. Para este fim foi realizada uma Revisão Sistemática dos estudos primários que estão inseridos neste contexto e por meio de uma Pesquisa de Produtos no Mercado, seguido da aplicação de um questionário para stakeholders foram extraÃdas caracterÃsticas relevantes para o desenvolvimento de uma solução para este cenário. Sendo assim o objetivo deste trabalho foi criar uma ferramenta que otimiza de forma inteligente o processo de oferta e procura de vagas de estacionamento, tendo em vista o número crescente de veÃculos e o espaço limitado das cidades como contribuição para o desenvolvimento das Cidades Inteligentes.São Cristóvã
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