962 research outputs found
Patient and health care professional decision-making to commence and withdraw from renal dialysis: A systematic review of qualitative research
Background and objectives. To ensure decisions to start and stop dialysis in end stage kidney disease are shared, the factors that affect patients and healthcare professionals in making such decisions need to be understood. This systematic review aims to explore how and why different factors mediate the choices about dialysis treatment. Design, setting, participants, and measurements. Medline, Embase, CINAHL and PsychINFO were searched for qualitative studies of factors that affect patients’ and/or healthcare professionals’ decisions to commence or withdraw from dialysis. A thematic synthesis was conducted. Results. Of 494 articles screened, 12 studies (conducted: 1985-2014) were included. These involved 206 predominantly haemodialysis patients and 64 healthcare professionals (age range: patients 26-93; professionals 26-61 years). (i) Commencing dialysis: patients based their choice on ‘gut-instinct’ as well as deliberating the impact of treatment on quality-of-life and survival. How individuals coped with decision-making was influential, some tried to take control of the problem of progressive renal failure, whilst others focussed on controlling their emotions. Healthcare professionals weighed-up biomedical factors and were led by an instinct to prolong life. Both patients and healthcare professionals described feeling powerless. (ii) Dialysis withdrawal: Only after prolonged periods of time on dialysis, were the realities of life on dialysis fully appreciated and past choice questioned. By this stage however patients were physically treatment dependent. Similar to commencing dialysis, individuals coped with treatment withdrawal in a problem or emotion-controlling way. Families struggled to differentiate choosing versus allowing death. Healthcare teams avoided and queried discussions regarding dialysis withdrawal. Patients however missed the dialogue they experienced during pre-dialysis education. Conclusions. Decision-making in end stage kidney disease is complex, dynamic, and evolves over time and towards death. The factors at work are multi-faceted and operate differently for patients and health professionals. More training and research on open-communication and shared decision-making is needed
A study of polar ozone depletion based on sequential assimilation of satellite data from the ENVISAT/MIPAS and Odin/SMR instruments
International audienceThe objective of this study is to demonstrate how polar ozone depletion can be mapped and quantified by assimilating ozone data from satellites into the wind driven transport model DIAMOND, (Dynamical Isentropic Assimilation Model for OdiN Data). By assimilating a large set of satellite data into a transport model, ozone fields can be built up that are less noisy than the individual satellite ozone profiles. The transported fields can subsequently be compared to later sets of incoming satellite data so that the rates and geographical distribution of ozone depletion can be determined. By tracing the amounts of solar irradiation received by different air parcels in a transport model it is furthermore possible to study the photolytic reactions that destroy ozone. In this study, destruction of ozone that took place in the Antarctic winter of 2003 and in the Arctic winter of 2002/2003 have been examined by assimilating ozone data from the ENVISAT/MIPAS and Odin/SMR satellite-instruments. Large scale depletion of ozone was observed in the Antarctic polar vortex of 2003 when sunlight returned after the polar night. By mid October ENVISAT/MIPAS data indicate vortex ozone depletion in the ranges 80?100% and 70?90% on the 425 and 475 K potential temperature levels respectively while the Odin/SMR data indicates depletion in the ranges 70?90% and 50?70%. The discrepancy between the two instruments has been attributed to systematic errors in the Odin/SMR data. Assimilated fields of ENVISAT/MIPAS data indicate ozone depletion in the range 10?20% on the 475 K potential temperature level, (~19 km altitude), in the central regions of the 2002/2003 Arctic polar vortex. Assimilated fields of Odin/SMR data on the other hand indicate ozone depletion in the range 20?30%
A New Smartphone-Based Optic Nerve Head Biometric for Verification and Change Detection
Purpose: Lens adapted smartphones are being used regularly instead of ophthalmoscopes. The most common causes of preventable blindness in the world, which are glaucoma and diabetic retinopathy, can develop asymptomatic changes to the optic nerve head (ONH) especially in the developing world where there is a dire shortage of ophthalmologists but ubiquitous mobile phones. We developed a proof-of-concept ONH biometric (application [APP]) to use as a routine biometric on a mobile phone. The unique blood vessel pattern is verified if it maps on to a previously enrolled image.
Methods: The iKey APP platform comprises three deep neural networks (DNNs) developed from anonymous ONH images: the graticule blood vessel (GBV) and the blood vessel specific feature (BVSF) DNNs were trained on unique blood vessel vectors. A non-feature specific (NFS) baseline ResNet50 DNN was trained for comparison.
Results: Verification reached an accuracy of 97.06% with BVSF, 87.24% with GBV and 79.8% using NFS.
Conclusions: A new ONH biometric was developed with a hybrid platform of ONH algorithms for use as a verification biometric on a smartphone. Failure to verify will alert the user to possible changes to the image, so that silent changes may be observed before sight threatening disease progresses. The APP retains a history of all ONH images. Future longitudinal analysis will explore the impact of ONH changes to the iKey biometric platform.
Translational Relevance: Phones with iKey will host ONH images for biometric protection of both health and financial data. The ONH may be used for automatic screening by new disease detection DNNs
The application of a Trous wave filtering and Monte Carlo analysis on SECIS 2001 solar eclipse observations
8000 images of the Solar corona were captured during the June 2001 total
Solar eclipse. New software for the alignment of the images and an automated
technique for detecting intensity oscillations using multi scale wavelet
analysis were developed. Large areas of the images covered by the Moon and the
upper corona were scanned for oscillations and the statistical properties of
the atmospheric effects were determined. The a Trous wavelet transform was used
for noise reduction and Monte Carlo analysis as a significance test of the
detections. The effectiveness of those techniques is discussed in detail.Comment: 17 pages, 8 figures, accepted by Solar Physics Journal for
publication in Topical Issue: "Frontiers in Solar Image Processing
Tomographic retrieval of water vapour and temperature around polar mesospheric clouds using Odin-SMR
Fast, Linear Time, m-Adic Hierarchical Clustering for Search and Retrieval using the Baire Metric, with linkages to Generalized Ultrametrics, Hashing, Formal Concept Analysis, and Precision of Data Measurement
We describe many vantage points on the Baire metric and its use in clustering
data, or its use in preprocessing and structuring data in order to support
search and retrieval operations. In some cases, we proceed directly to clusters
and do not directly determine the distances. We show how a hierarchical
clustering can be read directly from one pass through the data. We offer
insights also on practical implications of precision of data measurement. As a
mechanism for treating multidimensional data, including very high dimensional
data, we use random projections.Comment: 17 pages, 45 citations, 2 figure
Guidelines for the establishment of microbiological criteria for foods
O Grupo de Trabalho Ocorrência Microbiológica na Cadeia Alimentar
(GTOMCA) do Programa PortFIR considerou de grande importância o desenvolvimento
de um documento que compilasse uma seleção de legislação
e de informações relativas a Critérios Microbiológicos (CM), visando apoiar
e facilitar, aos operadores e entidades do setor alimentar, a sua aplicação
na validação do processo de produção, na segurança e/ou higiene dos géneros
alimentÃcios, na adesão a boas práticas de fabrico dos mesmos, e/ou,
ainda, na manutenção da sua qualidade durante o seu tempo de vida útil.
Deste modo, o GTOMCA desenvolveu o Guia para o estabelecimento de
critérios microbiológicos em géneros alimentÃcios, que foi publicado em
abril de 2017, contemplando a identificação, caraterÃsticas e propósito dos
CM, os fatores a considerar para a sua definição, nomeadamente: a categoria
do alimento, o microrganismo e/ou as suas toxinas, os metabolitos e
a virulência, os valores limite, o plano de amostragem, o tipo de utilização
e consumo assim como o método de análise laboratorial, o ponto da cadeia
alimentar onde se aplica, as medidas a tomar no caso de resultados não satisfatórios
e a necessidade de revisão e atualização dos CM.The Working Group on Microbiological Occurrence on the Food Chain
(GTOMCA) of Por tFIR Program considered unanimously, as an important
need, the existence of a document with a selection and compilation
of existing legislation and information concerning microbiological
criteria (CM) as a tool to suppor t and facilitate its application by operators
and entities in the food sector to validate the acceptability of
the production process or the food safety or hygiene, the obser vance
to good manufacturing practices or the maintenance of the food
quality during its lifetime. So, GTOMCA developed a Guide for the establishment
of microbiological criteria in foodstuf fs, which was published
in April 2017, regarding the identification, characteristics and
purpose of microbiological criteria, the factors to consider for its definition,
identification, characteristics and purpose of CM and, as impor
tant factors to consider the food categor y, the micro-organism
and its metabolites, toxins and virulence factors, the limit values, the
sampling plan, the type of food consumption as well as the analy tical
method for testing the food, the point of the food chain where it is applied,
the measures to be taken in the event of unsatisfactor y results
and the need to review and update of the CM.info:eu-repo/semantics/publishedVersio
Towards person-centered quality care for children with life-limiting and life-threatening illness: self-reported symptoms, concerns and priority outcomes from a multi-country qualitative study
Abstract Background: Paediatric life-limiting and life-threatening conditionslife-limiting conditions place significant strain on children, families and health systems. Given high service use among this population, it is essential that care addresses their main symptoms and concerns. Aim: This study aimed to identify the symptoms, concerns, and other outcomes that matter to children with life-limiting conditions and their families in sub-Saharan Africa.Setting and participants: Cross-sectional qualitative study in Kenya, Namibia, South Africa and Uganda. Children/caregivers of children aged 0-17 years with life-limiting conditions were purposively sampled by age, sex, and diagnosis. Children aged 7 and above self-reported; caregiver proxies reported for children below 7 and those aged 7 and above unable to self-report.Results: 120 interviews were conducted with children with life-limiting conditions (n=61 age range 7-17 years), and where self-report was not possible caregivers (n=59) of children (age range 0-17). Conditions included advanced HIV (22%), cancer (19%), heart disease (16%) endocrine, blood and immune disorders (13%), neurological conditions (12%), sickle cell anaemia (10%) and renal disease (8%). Outcomes identified included: physical concerns – pain and symptom distress; psycho-social concerns – family and social relationships, ability to engage with age-appropriate activities (e.g., play, school attendance); existential concerns – worry about death, and loss of ambitions,health care quality– child- and adolescent-friendly services. Priority psycho-social concerns and health service factors varied by age.Conclusion: This study bridges an important knowledge gap regarding symptoms, concerns and outcomes that matter to children living with life-limiting conditions and their families and informs service development and evaluation
Validation of the Aura Microwave Limb Sounder HNOmeasurements
We assess the quality of the version 2.2 (v2.2) HNO3 measurements from the Microwave Limb Sounder (MLS) on the Earth Observing System Aura satellite. The MLS HNO3 product has been greatly improved over that in the previous version (v1.5), with smoother profiles, much more realistic behavior at the lowest retrieval levels, and correction of a high bias caused by an error in one of the spectroscopy files used in v1.5 processing. The v2.2 HNO3 data are scientifically useful over the range 215 to 3.2 hPa, with single-profile precision of ∼0.7 ppbv throughout. Vertical resolution is 3–4 km in the upper troposphere and lower stratosphere, degrading to ∼5 km in the middle and upper stratosphere. The impact of various sources of systematic uncertainty has been quantified through a comprehensive set of retrieval simulations. In aggregate, systematic uncertainties are estimated to induce in the v2.2 HNO3 measurements biases that vary with altitude between ±0.5 and ±2 ppbv and multiplicative errors of ±5–15% throughout the stratosphere, rising to ∼±30% at 215 hPa. Consistent with this uncertainty analysis, comparisons with correlative data sets show that relative to HNO3 measurements from ground-based, balloon-borne, and satellite instruments operating in both the infrared and microwave regions of the spectrum, MLS v2.2 HNO3 mixing ratios are uniformly low by 10–30% throughout most of the stratosphere. Comparisons with in situ measurements made from the DC-8 and WB-57 aircraft in the upper troposphere and lowermost stratosphere indicate that the MLS HNO3 values are low in this region as well, but are useful for scientific studies (with appropriate averaging)
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