2,217 research outputs found
The UK NHS Economic Evaluation Database : Economic issues in evaluations of health technology
Objective: The U.K. NHS Economic Evaluation Database (EED) project is commissioned to identify papers on economic evaluations of health technologies and to disseminate their findings to NHS decision makers by means of structured abstracts that are available through a public database and the Cochrane Library. This paper discusses current issues relating to the economic aspects of producing NHS EED abstracts. Methods: A review of NHS EED was undertaken between 1994 and 1999 to determine the methodologies adopted and issues that influence the usefulness of economic evaluations. Methods adopted to improve the quality of NHS EED abstracts are also reported. Results: Eighty-five percent of NHS EED abstracts are cost-effectiveness analyses (CEAs), 9.3% are cost-utility analyses (CUAs), and only 1.4% are cost-benefit analyses (CBAs). Of the total abstracts, 65.9% are based on single studies, 19.5% on reviews, 3.9% on estimates of effectiveness, and 10.7% on combinations of these sources. Models are utilized in 16.7% of CEAs, 60.2% of CUAs, and 20% of CBAs. Analyses of CBA studies reveal a degree of misuse of well-established definitions. NHS EED internal control mechanisms are reported that provide a means of ensuring that abstracts are based on sound academic principles. Conclusions: Most economic evaluations are conducted by means of CEA, followed by CUA, while CBA accounts for an extreme minority of cases. Single studies form the principal source of effectiveness data, although models are widely used, principally in CUA. The structure of NHS EED abstracts provides decision makers with the principal results and an interpretation of the relative strengths and weaknesses of economic evaluations
Full-field stress analysis by holographic phase-stepping implementation of the photoelastic-coating method
In this paper, we describe a system for polariscopic and holographic phase-shifting implementation of the photoelastic-coating method for a full-field stress analysis. The easiest way to build the combined system is to employ a laser light source. However, coherent illumination introduces a signal-dependent speckle noise which worsens the accurate phase estimation and unwrapping. To answer the question of how it affects the phase retrieval of isochromatics, isoclinics and isopachics, we modeled in the present paper the phase-shifting photoelastic measurement in the presence of speckle noise through the calculation of the complex amplitudes in a Mach-Zender interferometer combined with a circular polariscope and made denoising of simulated and experimental fringe patterns. The latter were recorded at pure tensile load for PhotoStress (R)-coated samples with a mechanical stress concentrator
Speckle noise reduction in full-field stress analysis by interferometric phase-stepping implementation of the photoelastic-coating method
Zbtb20 modulates the sequential generation of neuronal layers in developing cortex
BACKGROUND: During corticogenesis, genetic programs encoded in progenitor cells at different developmental stages and inherited in postmitotic neurons specify distinct layer and area identities. Transcription factor Zbtb20 has been shown to play a role for hippocampal development but whether it is implicated in mammalian neocortical morphogenesis remains unknown. RESULTS: Here, we report that during embyogenesis transcription factor Zbtb20 has a dynamic spatio-temporal expression pattern in mitotic cortical progenitors through which it modulates the sequential generation of cortical neuronal layer identities. Zbtb20 knock out mice exhibited enhanced populations of early born L6-L4 neuronal subtypes and a dramatic reduction of the late born L3/L2 neurons. This defect was due to a temporal misbalance in the production of earlier versus later born neurons, leading to a progressive diminishing of the progenitor pool for the generation of L3-L2 neurons. Zbtb20 implements these temporal effects in part by binding to promoter of the orphan nuclear receptor CoupTF1/Nr2f1. In addition to its effects exerted in cortical progenitors, the postmitotic expression of Zbtb20 in L3/L2 neurons starting at birth may contribute to their proper differentiation and migration. CONCLUSIONS: Our findings reveal Zbtb20 as a novel temporal regulator for the generation of layer-specific neuronal identities
ARTISTIC: A randomised trial of human papillomavirus (HPV) testing in primary cervical screening
The official published version of the article can be found at the link below.Objectives: Primary cervical screening uses cytology to detect cancer precursor lesions [cervical intraepithelial neoplasia stage 3 or beyond (CIN3+)]. Human papillomavirus (HPV) testing could add sensitivity as an
adjunct to cytology or as a first test, reserving cytology for HPV-positive women. This study addresses the questions: Does the combination of cytology and HPV testing achieve a reduction in incident CIN3+?; Is HPV testing cost-effective in primary cervical screening?; Is its use associated with adverse psychosocial or psychosexual effects?; and How would it perform as an initial screening test followed by cytology for HPV positivity? Design: ARTISTIC was a randomised trial of cervical cytology versus cervical cytology plus HPV testing, evaluated over two screening rounds, 3 years apart. Round 1 would detect prevalent disease and round 2 a combination of incident and undetected disease from round 1.
Setting: Women undergoing routine cervical screening in the NHS programme in Greater Manchester. Participants: In total 24,510 women aged 20–64 years were enrolled between July 2001 and September 2003. Interventions: HPV testing was performed on the liquid-based cytology (LBC) sample obtained at
screening. Women were randomised in a ratio of 3:1 to have the HPV test result revealed and acted upon if persistently positive in cytology-negative cases or concealed. A detailed health economic evaluation and
a psychosocial and psychosexual assessment were also performed. Main outcome measures: The primary outcome was CIN3+ in round 2. Secondary outcomes included an economic assessment and psychosocial effects. A large
HPV genotyping study was also conducted.
Results: In round 1 there were 313 CIN3+ lesions, representing a prevalence in the revealed and concealed arms of 1.27% and 1.31% respectively (p = 0.81). Round 2 (30–48 months) involved 14,230 (58.1%) of
the women screened in round 1 and only 31 CIN3+ were detected; the CIN3 rate was not significantly different between the revealed and concealed arms. A less restrictive definition of round 2 (26–54 months) increased CIN3+ to 45 and CIN3+ incidence in the arms was significantly different (p = 0.05). There was no difference in CIN3+ between the arms when rounds 1 and 2 were combined. Prevalence of highrisk HPV types was age-dependent. Overall prevalence of HPV16/18 increased with severity of yskaryosis. Mean costs per woman in round 1 were £72 and £56 for the revealed and concealed arms (p < 0.001); an age-adjustment reduced these mean costs to £65 and £52. Incremental cost-effectiveness ratio for detecting additional CIN3+ by adding HPV testing to LBC screening in round 1 was £38,771. Age-adjusted mean cost for LBC primary screening with HPV triage was £39 compared with £48 for HPV primary screening with LBC triage. HPV testing did not appear to cause significant psychosocial distress. Conclusions: Routine HPV testing did not add significantly to the effectiveness of LBC in this study. No
significant adverse psychosocial effects were detected. It would not be cost-effective to screen with cytology and HPV combined but HPV testing, as either triage or initial test triaged by cytology, would be cheaper than cytology without HPV testing. LBC would not benefit from combination with HPV; it is highly effective as primary screening but HPV testing has twin advantages of high negative predictive value and automated platforms enabling high throughput. HPV primary screening would require major contraction and reconfiguration of laboratory services. Follow-up continues in ARTISTIC while maintaining concealment for a further 3-year
round of screening, which will help in screening protocol development for the post-vaccination era
A stream of cells migrating from the caudal telencephalon reveals a link between the amygdala and neocortex
BAF(mSWI/SNF) complex regulates mediolateral cortical patterning in the developing forebrain
Early forebrain patterning entails the correct regional designation of the neuroepithelium, and appropriate specification, generation, and distribution of neural cells during brain development. Specific signaling and transcription factors are known to tightly regulate patterning of the dorsal telencephalon to afford proper structural/functional cortical arealization and morphogenesis. Nevertheless, whether and how changes of the chromatin structure link to the transcriptional program(s) that control cortical patterning remains elusive. Here, we report that the BAF chromatin remodeling complex regulates the spatiotemporal patterning of the mouse dorsal telencephalon. To determine whether and how the BAF complex regulates cortical patterning, we conditionally deleted the BAF complex scaffolding subunits BAF155 and BAF170 in the mouse dorsal telencephalic neuroepithelium. Morphological and cellular changes in the BAF mutant forebrain were examined using immunohistochemistry and in situ hybridization. RNA sequencing, Co-immunoprecipitation, and mass spectrometry were used to investigate the molecular basis of BAF complex involvement in forebrain patterning. We found that conditional ablation of BAF complex in the dorsal telencephalon neuroepithelium caused expansion of the cortical hem and medial cortex beyond their developmental boundaries. Consequently, the hippocampal primordium is not specified, the mediolateral cortical patterning is compromised, and the cortical identity is disturbed in the absence of BAF complex. The BAF complex was found to interact with the cortical hem suppressor LHX2. The BAF complex suppresses cortical hem fate to permit proper forebrain patterning. We provide evidence that BAF complex modulates mediolateral cortical patterning possibly by interacting with the transcription factor LHX2 to drive the LHX2-dependent transcriptional program essential for dorsal telencephalon patterning. Our data suggest a putative mechanistic synergy between BAF chromatin remodeling complex and LHX2 in regulating forebrain patterning and ontogeny
Web-based monitoring tools for Resistive Plate Chambers in the CMS experiment at CERN
The Resistive Plate Chambers (RPC) are used in the CMS experiment at the trigger level and also in the standard offline muon reconstruction. In order to guarantee the quality of the data collected and to monitor online the detector performance, a set of tools has been developed in CMS which is heavily used in the RPC system. The Web-based monitoring (WBM) is a set of java servlets that allows users to check the performance of the hardware during data taking, providing distributions and history plots of all the parameters. The functionalities of the RPC WBM monitoring tools are presented along with studies of the detector performance as a function of growing luminosity and environmental conditions that are tracked over time
Radiation background with the CMS RPCs at the LHC
The Resistive Plate Chambers (RPCs) are employed in the CMS Experiment at the LHC as dedicated trigger system both in the barrel and in the endcap. This article presents results of the radiation background measurements performed with the 2011 and 2012 proton-proton collision data collected by CMS. Emphasis is given to the measurements of the background distribution inside the RPCs. The expected background rates during the future running of the LHC are estimated both from extrapolated measurements and from simulation
Interaction between Axons and Specific Populations of Surrounding Cells Is Indispensable for Collateral Formation in the Mammillary System
An essential phenomenon during brain development is the extension of long collateral branches by axons. How the local cellular environment contributes to the initial sprouting of these branches in specific points of an axonal shaft remains unclear.The principal mammillary tract (pm) is a landmark axonal bundle connecting ventral diencephalon to brainstem (through the mammillotegmental tract, mtg). Late in development, the axons of the principal mammillary tract sprout collateral branches at a very specific point forming a large bundle whose target is the thalamus. Inspection of this model showed a number of distinct, identified cell populations originated in the dorsal and the ventral diencephalon and migrating during development to arrange themselves into several discrete groups around the branching point. Further analysis of this system in several mouse lines carrying mutant alleles of genes expressed in defined subpopulations (including Pax6, Foxb1, Lrp6 and Gbx2) together with the use of an unambiguous genetic marker of mammillary axons revealed: 1) a specific group of Pax6-expressing cells in close apposition with the prospective branching point is indispensable to elicit axonal branching in this system; and 2) cooperation of transcription factors Foxb1 and Pax6 to differentially regulate navigation and fasciculation of distinct branches of the principal mammillary tract.Our results define for the first time a model system where interaction of the axonal shaft with a specific group of surrounding cells is essential to promote branching. Additionally, we provide insight on the cooperative transcriptional regulation necessary to promote and organize an intricate axonal tree
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