2,951 research outputs found
Do good health and material circumstances protect older people from the increased risk of death after bereavement?
No full textThis is an open access Article. Copyright @ 2012 The AuthorsAn increased risk of death in persons who have suffered spousal bereavement has been described in many populations. The impact of modifying factors, such as chronic disease and material circumstances, is less well understood. The authors followed 171,120 couples 60 years of age or older in a United Kingdom primary care database between 2005 and 2010 for an average of 4 years. A total of 26,646 (15.5%) couples experienced bereavement, with mean follow up after bereavement of 2 years. In a model adjusted for age, sex, comorbid conditions at baseline, material deprivation based on area of residence, season, and smoking status, the hazard ratio for mortality in the first year after bereavement was 1.25 (95% confidence interval: 1.18, 1.33). Further adjustment for changes in comorbid conditions throughout follow up did not alter the hazard ratio for bereavement (hazard ratio = 1.27, 95% confidence interval: 1.19, 1.35). The association was strongest in individuals with no significant chronic comorbid conditions throughout follow up (hazard ratio = 1.50, 95% confidence interval: 1.28, 1.77) and in more affluent couples (P = 0.035). In the first year after bereavement, the association between bereavement and death is not primarily mediated through worsening or new onset of chronic disease. Good health and material circumstances do not protect individuals from increased mortality rates after bereavement.This study was funded by a grant from the Dunhill Medical Trust
Detecting referral and selection bias by the anonymous linkage of practice, hospital and clinic data using Secure and Private Record Linkage (SAPREL): case study from the evaluation of the Improved Access to Psychological Therapy (IAPT) service.
No full textBACKGROUND: The evaluation of demonstration sites set up to provide improved access to psychological therapies (IAPT) comprised the study of all people identified as having common mental health problems (CMHP), those referred to the IAPT service, and a sample of attenders studied in-depth. Information technology makes it feasible to link practice, hospital and IAPT clinic data to evaluate the representativeness of these samples. However, researchers do not have permission to browse and link these data without the patients' consent.
OBJECTIVE: To demonstrate the use of a mixed deterministic-probabilistic method of secure and private record linkage (SAPREL)--to describe selection bias in subjects chosen for in-depth evaluation.
METHOD: We extracted, pseudonymised and used fuzzy logic to link multiple health records without the researcher knowing the patient's identity. The method can be characterised as a three party protocol mainly using deterministic algorithms with dynamic linking strategies; though incorporating some elements of probabilistic linkage. Within the data providers' safe haven we extracted: Demographic data, hospital utilisation and IAPT clinic data; converted post code to index of multiple deprivation (IMD); and identified people with CMHP. We contrasted the age, gender, ethnicity and IMD for the in-depth evaluation sample with people referred to IAPT, use hospital services, and the population as a whole.
RESULTS: The in IAPT-in-depth group had a mean age of 43.1 years; CI: 41.0-45.2 (n=166); the IAPT-referred 40.2 years; CI: 39.4-40.9 (n=1118); and those with CMHP 43.6 years SEM 0.15. (n=12210). Whilst around 67% of those with a CMHP were women, compared to 70% of those referred to IAPT, and 75% of those subject to in-depth evaluation (Chi square p<0.001). The mean IMD score for the in-depth evaluation group was 36.6; CI: 34.2-38.9; (n=166); of those referred to IAPT 38.7; CI: 37.9-39.6; (n=1117); and of people with CMHP 37.6; CI 37.3-37.9; (n=12143).
CONCLUSIONS: The sample studied in-depth were older, more likely female, and less deprived than people with CMHP, and fewer had recorded ethnic minority status. Anonymous linkage using SAPREL provides insight into the representativeness of a study population and possible adjustment for selection bias
Elektronenmikroskopische und Gerinnungsuntersuchungen bei einem Fall von primärer (idiopathischer) Thrombozythämie im Kindesalter.
No full textDas Krankheitsbild der primären (idiopathischen) Thrombozythämie ist im Kindesalter sehr selten. Hämorrhagische Diathese, Splenomegalie und Vermehrung der Thrombozyten stellen die Leitsymptome dar. Der Fall eines 9jährigen Mädchens mit Thrombozytenwerten zwischen 2,8 und 4,5×106/mm3 wird beschrieben. Licht- und elektronenoptisch fand sich ein defekter Zellaufbau von Megakaryozyten und Thrombozyten. Die Funktionsdiagnostik zeigte eine defekte thrombozytäre Reaktivität. Diese Befunde werden zu der bestehenden hämorrhagischen Diathese sowie zu Befunden bei primärer und sekundärer Thrombozytämie im Erwachsenenalter in Beziehung gesetzt. Der mögliche Zusammenhang mit myeloproliferativen Syndromen wird diskutiert
Developing consensus on national respiratory research priorities: Key findings from the UK Respiratory Research Collaborative's e-Delphi exercise
No full textSpatio-temporal neural networks in High Impedance Fault detection
No full textVita.The tim ely detection and isolation of High Impedance Faults(HIFs) are im portan t to ensure the safety of the public and the property around power distribution lines. The existing protection measures are highly inadequate for this task. Although a num ber of attem pts to develop HIF detectors were m ade, all of them were unable to provide a complete solution to this problem. The inability of conventional pattern recognition approaches to classify noisy spatio-tem poral patterns in environments such as, inexact detection knowledge and m ulti-param eter relationships, is considered to be the prim ary reason for the status quo. The objective of this research work is to explore the use of Artificial Neural Network(ANN) techniques in developing a HIF detection system. As the first step towards this ultim ate goal, the capabilities of three ANN architectures to detect these faults were investigated for this research work. The network architecture is critical to the success of any classifier developed using ANN approaches. This is so, because, the architecture dictates the network topology, the training algorithm to be used to train networks, and th e training procedure. Since HIF detection is a spatio-tem poral p attern recognition problem, the capabilities of three spatio-tem poral ANN approaches, buffered Multi-Layer Perceptron(M LP), Time-Delay Neural Network(TDNN), and Simple Recurrent Network(SRN), were investigated for this research. This dissertation describes the work we have done to explore the use of the three ANN architectures in detecting HIFs. Two of those architectures, TDNN and SRN, were applied outside of their prim ary operational domains and paradigms. The details of the new m odular feature extraction process th at was developed to facilitate HIF detection, the issues involved in training networks from the three ANN architectures, the output performances of the developed networks are described in this dissertation. Additionally, the network analysis work th at was done to determ ine the characteristics of the detection procedures used by the networks are also described
Torque de remo??o de implantes lisos e texturizados com e sem estabilidade prim?ria associados ou n?o ao plasma rico em plaquetas
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Previous issue date: 2006-12-21O objetivo desse estudo foi avaliar o torque de remo??o de implantes lisos e texturizados sem estabilidade prim?ria associados a plasma rico em plaquetas. Foi utilizado um total de sete coelhos f?meas, brancas da ra?a Nova Zel?ndia Branco (Oryctolagos cuniculus l.). Em cada coelho foram instalados 6 implantes, 3 para cada t?bia, de acordo com os seguintes grupos experimentais: 1- implante liso com estabilidade prim?ria e sem PRP (plasma rico em plaquetas); 2- implante liso sem estabilidade prim?ria e sem PRP; 3- implante liso sem estabilidade prim?ria e com PRP; 4- implante texturizado com estabilidade prim?ria e sem PRP; 5- implante texturizado sem estabilidade prim?ria e sem PRP; 6- implante texturizado sem estabilidade prim?ria e com PRP. Os protocolos cir?rgicos foram aplicados de acordo com cada grupo experimental e ap?s um per?odo de 9 semanas, os animais foram mortos. Logo ap?s a morte dos animais, a mensura??o do torque de remo??o foi realizada. As m?dias dos grupos foram: grupo 1, 53,01 Ncm (?9,68); grupo 2, 45,29 Ncm (?16, 90); grupo 3, 43,43 Ncm (?16,70); grupo 4, 56,60 Ncm (?16,00); grupo 5, 46,89 Ncm (?15,60) e grupo 6, 48,49 Ncm (?17,06). Os dados foram analisados atrav?s da An?lise de Vari?ncia M?ltipla, utilizando o delineamento em blocos casualizados que demonstrou n?o haver diferen?a estat?stica entre os grupos ao n?vel de 5% nas condi??es experimentais estabelecidas. As distintas condi??es experimentais n?o foram capazes de promover diferen?a no torque de remo??o
Vibrational potential energy functions and conformations of cyclopentanone and cyclobutanone in their electronic excited states
No full textVita.T he jet-cooled fluorescence excitation spectra o f cyclopentanone, cyciobutanone and their isotopom ers have been recorded in the 305-335 nm region, respectively. T he electronic band origin for the tw o undeuterated species was determ ined to be 30276 and 30292 cm '1 for the S, (n,7r) electronic excited states, respectively. M ore than one hundred fluorescence bands w ere assigned for each cyclopentanone species, and m ore than fifty for each cyciobutanone species. T hese arise prim arily from combinations o f carbonyl m otions and out-of-plane ring modes. E ight bands associated with the excited vibrational states o f the C = 0 out-of-plane wag in the S, electronic states w ere observed for each cyclopentanone isotopom er, and five bands for each cyciobutanone isotopom er. These w ere used to determ ine the one-dimensional potential energies functions fo r th e C = O out-of-plane wagging. T he C = O w agging angle was determ ined to be 2 2 ' , and the b arrier to inversion is 6 7 2 + 1 0 cm '1 for cyclopentanone. These values are 3 9 ' , and 2 1 6 9 + 2 0 cm '1 for cyciobutanone. In the spectrum o f cyclopentanone a progression observed for vn (ring bending) indicates that in the S, state the bent ring conformation lies about 500 c m 1 above the ring-tw isting minimum and corresponds to a saddle point in the two-dim ensional ring-tw isting/ring-bending potential energy surface. Band progressions for vlg (ring tw isting) can be used to estimate the ring-tw isting barriers (the barriers to planarity) for the do and d4 isotopom ers to be 1433 and 1240 cm '1, respectively. F o r the ring-puckering vibration in the S, state o f cyciobutanone the low est three vibrational energy spacings w ere found to be 106, 166 and 185 cm '1 as com pared to values of 35, 57 and 65 cm '1 in the S ground state. Several ring-puckering potential energy functions with varying degrees o f asym m etry are capable o f reproducing the observed results. In all cases, how ever, the v = 0 puckering state lies above any barrier to planarity. A tw o-dim ensional potential function which fits the observed data was also determ ined in term s o f the w agging and puckering coordinates
Central Double Centralizers on Quasi-Central Banach Algebras with Bounded Approximate Identity
No full textWe assume throughout this paper that A is a semi-simple, quasi-central, complex Banach algebra with a bounded approximate identity {eα}. The author [6] has shown that every central double centralizer T on A can be, under suitable conditions, represented as a bounded continuous complex-valued function ΦT on Prim A, the structure space of A with the hull-kernel topology, such thatHere x + P for P ∊ Prim A denotes the canonical image of x in A/P. This map Φ is called Dixmier's representation of Z(M(A)), the central double centralizer algebra of A. We denote by τ the canonical isomorphism of A into the Banach algebra D(A) with the restricted Arens product as defined in [6]. Also denote by μ Davenport's representation of Z(M(A)). In fact, this map μ is given byfor each T ∊ Z(M(A)).</jats:p
Adoption and non-adoption of a shared electronic summary record in England: a mixed-method case study.
No full textOBJECTIVE: To evaluate a national programme to develop and implement centrally stored electronic summaries of patients' medical records. DESIGN: Mixed-method, multilevel case study. SETTING: English National Health Service 2007-10. The summary care record (SCR) was introduced as part of the National Programme for Information Technology. This evaluation of the SCR considered it in the context of national policy and its frontline implementation and use in three districts. Participants and methods Quantitative data (cumulative records created nationally plus a dataset of 416 325 encounters in participating primary care out-of-hours and walk-in centres) were analysed statistically. Qualitative data (140 interviews including policy makers, managers, clinicians, and software suppliers; 2000 pages of ethnographic field notes including observation of 214 clinical consultations; and 3000 pages of documents) were analysed thematically and interpretively. RESULTS: Creating individual SCRs and supporting their adoption and use was a complex, technically challenging, and labour intensive process that occurred more slowly than planned. By early 2010, 1.5 million such records had been created. In participating primary care out-of-hours and walk-in centres, an SCR was accessed in 4% of all encounters and in 21% of encounters where one was available; these figures were rising in some but not all sites. The main determinant of SCR access was the identity of the clinician: individual clinicians accessed available SCRs between 0 and 84% of the time. When accessed, an SCR seemed to support better quality care and increase clinician confidence in some encounters. There was no direct evidence of improved safety, but findings were consistent with a rare but important positive impact on preventing medication errors. SCRs sometimes contained incomplete or inaccurate data, but clinicians drew judiciously on these data along with other sources. SCR use was not associated with shorter consultations or reduction in onward referral. Successful introduction of SCRs depended on interaction between multiple stakeholders from different worlds (clinical, political, technical, commercial) with different values, priorities, and ways of working. The programme's fortunes seemed to turn on the ability of change agents to bridge these different institutional worlds, align their conflicting logics, and mobilise implementation effort. CONCLUSIONS: Benefits of centrally stored electronic summary records seem more subtle and contingent than many stakeholders anticipated, and clinicians may not access them. Complex interdependencies, inherent tensions, and high implementation workload should be expected when they are introduced on a national scale
Designing role-based view for object-relational databases
No full textIn a federated database system, a view mechanism is crucial since it is used to define exportable subsets of data ; to perform a virtual restructuring d ataset; and to construct the integrated schema. The view service in federated databa se systems must be capable of retaining as much semantic information as possible. The object-oriented ( 0 - 0 ) model was considered the suitable canonical data model since it meets the original criteria for canonical model selection. However, with the emergence of stronger object-relational (0 -R ) model, the re is a clear argument for using an 0 - R canonical model in the federation. Hence, research should now focus on th e development of semantically powerful view mechanism for th e newer model. Meanwhile, the availability of real 0 -R technologies offers researchers the opportunity to develop different forms of view mechanisms.
The concept of roles has been widely studied in 0 - 0 modelling and development. The role model represents some characteristics that the traditional 0-0 model lacked, such as object migration, multiple occurrences and context-dependent access. While many forms of 0-0 views were designed for the 0-0 canonical model, one option was to extend the 0-0 model to incorporate a role model. In a role model, the real entity is modelled in the form of a role rather than an object. An object represents the permanent properties of an entity is a root object; and an object represents the temporary properties of an entity is a role object.
The contribution of this research is to design a view system that employees the concept of roles for the 0 -R canonical model in a federated database system. In this thesis, an examination of the current 0 -R metamodel is provided first in order to provide an environment for recognising the roleview metadata and measuring the view performance; then a Roleview Definition Language (RDL) is introduced, along with the semantics for defining virtual classes and generating virtua l extents; finally, a working prototype is provided to prove th e role-based view system is implementable and the syntax is semantically correct
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