1,106 research outputs found
FAPRIL: Towards Faster Privacy-Preserving Fingerprint-Based Localization
Fingerprinting is a commonly used technique to provide accurate localization for indoor areas, where global navigation satellite systems, such as GPS and Galileo, cannot function or are not precise enough. Although fingerprint-based indoor localization has gained wide popularity, existing solutions that preserve privacy either rely on non-colluding servers or have high communication which hinder deployment.
In this work we present FAPRIL, a privacy-preserving indoor localization scheme, which takes advantage of the latest secure two-party computation protocol improvements. We can split our scheme into two parts: an input independent setup phase and an online phase. We concentrate on optimizing the online phase for mobile clients who run on a mobile data plan and observe that recurring operands allow to optimize the total communication overhead even further. Our observation can be generalized, e.g., to improve multiplication of Arithmetic secret shared matrices. We implement FAPRIL on mobile devices and our benchmarks over a simulated LTE network show that the online phase of a private localization takes under 0.15 seconds with less than 0.20 megabytes of communication even for large buildings. The setup phase, which can be pre-computed, depends heavily on the setting but stays in the range 0.28 - 4.14 seconds and 0.69 - 16.00 megabytes per localization query. The round complexity of FAPRIL is constant for both phases
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Writ(h)ing Images: Imagination, the Human Form, and the Divine in William Blake, Salman Rushdie, and Simon Louvish
In this paper, we address issues in segmentation Of remotely sensed LIDAR (LIght Detection And Ranging) data. The LIDAR data, which were captured by airborne laser scanner, contain 2.5 dimensional (2.5D) terrain surface height information, e.g. houses, vegetation, flat field, river, basin, etc. Our aim in this paper is to segment ground (flat field)from non-ground (houses and high vegetation) in hilly urban areas. By projecting the 2.5D data onto a surface, we obtain a texture map as a grey-level image. Based on the image, Gabor wavelet filters are applied to generate Gabor wavelet features. These features are then grouped into various windows. Among these windows, a combination of their first and second order of statistics is used as a measure to determine the surface properties. The test results have shown that ground areas can successfully be segmented from LIDAR data. Most buildings and high vegetation can be detected. In addition, Gabor wavelet transform can partially remove hill or slope effects in the original data by tuning Gabor parameters
Hyperparathyroidism, platelet intracellular free calcium and hypertension in chronic renal failure
Hyperparathyroidism, platelet intracellular free calcium and hypertension in chronic renal failure. To investigate possible relationships between hyperparathyroidism, alterations in intracellular free calcium concentration ([Ca2+]i and hypertension in chronic renal failure, serum concentrations of intact parathyroid hormone (PTH) were measured by two-site immunometric assay, and platelet ([Ca2+]i) was assessed using the fluorescent indicator fura-2. Thirty-six patients with chronic renal failure were studied, 10 with normal serum PTH concentrations (mean 8.0 ± 0.6 pmol/liter), 17 with elevated serum PTH (35.0 ± 7.2 pmol/liter) and 9 patients with elevated PTH (36.2 ±5.9 pmol/liter) who were receiving nifedipine. Platelet [Ca2+]i was increased in patients with elevated PTH, compared with those in whom PTH was normal (138 ± 16 vs. 83 ± 7 nmol/liter, P < 0.01). A linear relation was observed between serum PTH and platelet [Ca2+]i in these patients (r = 0.818, P < 0.001). In contrast, platelet [Ca2+]i was not elevated (84 ± 9 nmol/liter) in the patients with elevated PTH who were receiving nifedipine. A linear relation was also present between both serum PTH (r = 0.616, P < 0.001) and platelet [Ca2+]i (r = 0.576, P < 0.005) and mean blood pressure. Nine patients with hyperparathyroidism were restudied after treatment with the vitamin D analogue alfacalcidol. This resulted in significant decreases in serum PTH (P < 0.01), platelet [Ca2+]i (P < 0.02), and mean blood pressure (P < 0.05). These studies indicate that [Ca2+]i may be increased early in renal failure, and that this increase occurs in association with both hyperparathyroidism and hypertension. Furthermore, treatment of hyperparathyroidism with alfacalcidol may result in reductions in both [Ca2+]i and blood pressure. The lack of elevation in [Ca2+]i in nifedipine-treated patients with hyperparathyroidism suggests that, in uremia, increases in cytosolic calcium induced by PTH or other factors may be mediated in part by dihydropyridine-sensitive mechanisms
Low autonomic arousal as a risk factor for reoffending : A population-based study
Background Low resting heart rate (RHR) and low systolic blood pressure (SBP) are associated with criminal behavior. However, knowledge is lacking about their predictive value for reoffending. Aim We aimed to examine associations of RHR and SBP with reoffending in a large population-based sample. Methods We conducted a cohort study of all convicted male conscripts born in Sweden 1958-1990 (N = 407,533). We obtained data by linking Swedish population-based registers. Predictor variables were RHR and SBP, measured at conscription which was mandatory until 2010 for men at age 18. The outcome variable was reoffending, defined as criminal convictions (any crime, violent crime and non-violent crime), obtained from the National Crime Register. We used survival analyses to test for associations of RHR and SBP with reoffending, adjusting for pertinent covariates such as socioeconomic status, height, weight and physical energy capacity. Results In fully adjusted Cox regression models, men with lower RHR (= 82 bpm). Men with lower SBP (= 138 mmHg). Conclusions Low autonomic arousal is associated with increased risk of reoffending. RHR and SBP should be investigated further as potential predictors for reoffending as they each may have predictive value in risk assessment protocols.Peer reviewe
Patient attitudes toward using computers to improve health services delivery
BACKGROUND: The aim of this study was to examine the acceptability of point of care computerized prompts to improve health services delivery among a sample of primary care patients. METHODS: Primary data collection. Cross-sectional survey. Patients were surveyed after their visit with a primary care provider. Data were obtained from patients of ten community-based primary care practices in the spring of 2001. RESULTS: Almost all patients reported that they would support using a computer before each visit to prompt their doctor to: "do health screening tests" (92%), "counsel about health behaviors (like diet and exercise)" (92%) and "change treatments for health conditions" (86%). In multivariate testing, the only variable that was associated with acceptability of the point of care computerized prompts was patient's confidence in their ability to answer questions about their health using a computer (beta = 0.39, p = .001). Concerns about data security were expressed by 36.3% of subjects, but were not related to acceptability of the prompts. CONCLUSIONS: Support for using computers to generate point of care prompts to improve quality-oriented processes of care was high in our sample, but may be contingent on patients feeling familiar with their personal medical history
Trial summary and protocol for a phase II randomised placebo-controlled double-blinded trial of Interleukin 1 blockade in Acute Severe Colitis: the IASO trial.
INTRODUCTION: Acute severe ulcerative colitis (ASUC) is a severe manifestation of ulcerative colitis (UC) that warrants hospitalisation. Despite significant advances in therapeutic options for UC and in the medical management of steroid-refractory ASUC, the initial treatment paradigm has not changed since 1955 and is based on the use of intravenous corticosteroids. This treatment is successful in approximately 50% of patients but failure of this and subsequent medical therapy still occurs, with colectomy rates of up to 40% reported. The Interleukin 1 (IL-1) blockade in Acute Severe Colitis (IASO) trial aims to investigate whether antagonism of IL-1 signalling using anakinra in addition to intravenous corticosteroid treatment can improve outcomes in patients with ASUC. METHODS AND ANALYSIS: IASO is a phase II, multicentre, two-arm (parallel group), randomised (1:1), placebo-controlled, double-blinded trial of short-duration anakinra in ASUC. Its primary outcome will be the incidence of medical (eg, infliximab/ciclosporin) or surgical rescue therapy (colectomy) within 10 days following the commencement of intravenous corticosteroid therapy. Secondary outcomes will include disease activity, time to clinical response, time to rescue therapy, colectomy incidence by day 98 post intravenous corticosteroids and safety. The trial aims to recruit 214 patients across 20 sites in the UK. ETHICS AND DISSEMINATION: The trial has received approval from the Cambridge Central Research Ethics Committee (Ref: 17/EE/0347), the Health Research Authority (Ref: 201505) and Clinical Trials Authorisation from the Medicines and Healthcare products Regulatory Agency. We plan to present trial findings at scientific conferences and publish in high-impact peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN43717130; EudraCT 2017-001389-10.NIH
Conservative management versus tonsillectomy in adults with recurrent acute tonsillitis in the UK (NATTINA) : a multicentre, open-label, randomised controlled trial
This study was funded by the NIHR Health Technology Assessment programme (12/146/06).Background Tonsillectomy is regularly performed in adults with acute tonsillitis, but with scarce evidence. A reduction in tonsillectomies has coincided with an increase in acute adult hospitalisation for tonsillitis complications. We aimed to assess the clinical effectiveness and cost-effectiveness of conservative management versus tonsillectomy in patients with recurrent acute tonsillitis. Methods This pragmatic multicentre, open-label, randomised controlled trial was conducted in 27 hospitals in the UK. Participants were adults aged 16 years or older who were newly referred to secondary care otolaryngology clinics with recurrent acute tonsillitis. Patients were randomly assigned (1:1) to receive tonsillectomy or conservative management using random permuted blocks of variable length. Stratification by recruiting centre and baseline symptom severity was assessed using the Tonsil Outcome Inventory-14 score (categories defined as mild 0–35, moderate 36–48, or severe 49–70). Participants in the tonsillectomy group received elective surgery to dissect the palatine tonsils within 8 weeks after random assignment and those in the conservative management group received standard non-surgical care during 24 months. The primary outcome was the number of sore throat days collected during 24 months after random assignment, reported once per week with a text message. The primary analysis was done in the intention-to-treat (ITT) population. This study is registered with the ISRCTN registry, 55284102. Findings Between May 11, 2015, and April 30, 2018, 4165 participants with recurrent acute tonsillitis were assessed for eligibility and 3712 were excluded. 453 eligible participants were randomly assigned (233 in the immediate tonsillectomy group vs 220 in the conservative management group). 429 (95%) patients were included in the primary ITT analysis (224 vs 205). The median age of participants was 23 years (IQR 19–30), with 355 (78%) females and 97 (21%) males. Most participants were White (407 [90%]). Participants in the immediate tonsillectomy group had fewer days of sore throat during 24 months than those in the conservative management group (median 23 days [IQR 11–46] vs 30 days [14–65]). After adjustment for site and baseline severity, the incident rate ratio of total sore throat days in the immediate tonsillectomy group (n=224) compared with the conservative management group (n=205) was 0·53 (95% CI 0·43 to 0·65;Publisher PDFPeer reviewe
Tonsillectomy compared with conservative management in patients over 16 years with recurrent sore throat:the NATTINA RCT and economic evaluation
BACKGROUND: The place of tonsillectomy in the management of sore throat in adults remains uncertain.OBJECTIVES: To establish the clinical effectiveness and cost-effectiveness of tonsillectomy, compared with conservative management, for tonsillitis in adults, and to evaluate the impact of alternative sore throat patient pathways.DESIGN: This was a multicentre, randomised controlled trial comparing tonsillectomy with conservative management. The trial included a qualitative process evaluation and an economic evaluation.SETTING: The study took place at 27 NHS secondary care hospitals in Great Britain.PARTICIPANTS: A total of 453 eligible participants with recurrent sore throats were recruited to the main trial.INTERVENTIONS: Patients were randomised on a 1 : 1 basis between tonsil dissection and conservative management (i.e. deferred surgery) using a variable block-stratified design, stratified by (1) centre and (2) severity.MAIN OUTCOME MEASURES: The primary outcome measure was the total number of sore throat days over 24 months following randomisation. The secondary outcome measures were the number of sore throat episodes and five characteristics from Sore Throat Alert Return, describing severity of the sore throat, use of medications, time away from usual activities and the Short Form questionnaire-12 items. Additional secondary outcomes were the Tonsil Outcome Inventory-14 total and subscales and Short Form questionnaire-12 items 6 monthly. Evaluation of the impact of alternative sore throat patient pathways by observation and statistical modelling of outcomes against baseline severity, as assessed by Tonsil Outcome Inventory-14 score at recruitment. The incremental cost per sore throat day avoided, the incremental cost per quality-adjusted life-year gained based on responses to the Short Form questionnaire-12 items and the incremental net benefit based on costs and responses to a contingent valuation exercise. A qualitative process evaluation examined acceptability of trial processes and ramdomised arms.RESULTS: There was a median of 27 (interquartile range 12-52) sore throats over the 24-month follow-up. A smaller number of sore throats was reported in the tonsillectomy arm [median 23 (interquartile range 11-46)] than in the conservative management arm [median 30 (interquartile range 14-65)]. On an intention-to-treat basis, there were fewer sore throats in the tonsillectomy arm (incident rate ratio 0.53, 95% confidence interval 0.43 to 0.65). Sensitivity analyses confirmed this, as did the secondary outcomes. There were 52 episodes of post-operative haemorrhage reported in 231 participants undergoing tonsillectomy (22.5%). There were 47 re-admissions following tonsillectomy (20.3%), 35 relating to haemorrhage. On average, tonsillectomy was more costly and more effective in terms of both sore throat days avoided and quality-adjusted life-years gained. Tonsillectomy had a 100% probability of being considered cost-effective if the threshold for an additional quality-adjusted life year was £20,000. Tonsillectomy had a 69% probability of having a higher net benefit than conservative management. Trial processes were deemed to be acceptable. Patients who received surgery were unanimous in reporting to be happy to have received it.LIMITATIONS: The decliners who provided data tended to have higher Tonsillectomy Outcome Inventory-14 scores than those willing to be randomised implying that patients with a higher burden of tonsillitis symptoms may have declined entry into the trial.CONCLUSIONS: The tonsillectomy arm had fewer sore throat days over 24 months than the conservative management arm, and had a high probability of being considered cost-effective over the ranges considered. Further work should focus on when tonsillectomy should be offered. National Trial of Tonsillectomy IN Adults has assessed the effectiveness of tonsillectomy when offered for the current UK threshold of disease burden. Further research is required to define the minimum disease burden at which tonsillectomy becomes clinically effective and cost-effective.TRIAL REGISTRATION: This trial is registered as ISRCTN55284102.FUNDING: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/146/06) and is published in full in Health Technology Assessment; Vol. 27, No. 31. See the NIHR Funding and Awards website for further award information. </p
Improving land use change tracking in the UK Greenhouse Gas Inventory: final outputs report
This report describes work on the project “Improving Land Use Change Tracking in the UK Greenhouse Gas Inventory” for the Department for Business, Energy & Industrial Strategy (reference TRN 2384/05/2020). The aim of the project was to make improved estimates of land-use change in the UK,
using multiple sources of data. We applied a method for estimating land-use change using a Bayesian data assimilation approach. This allows us to constrain estimates of gross land-use change with national-scale census data, whilst retaining the detailed information available from several other sources. We produced a time series of maps describing our best estimate of land-use change given the
available data, as well as the full posterior distribution of this space-time data cube. This quantifies the
joint probability distribution of the parameters, and properly propagates the uncertainty from input
data to final output. The output data has been summarised in the form of land-use vectors. The results
show that we can provide improved estimates of past land-use change using this method. The main advantage of the approach is that it provides a coherent, generalised framework for combining multiple disparate sources of data, and adding further sources of data in future would be straightforward. Future work could focus on more detailed analysis of existing data sets, introducing independent constraints where possible, and obtaining further relevant data sets. The code is available via GitHub
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