Tracking Target Signal Strengths on a Grid using Sparsity

Multi-target tracking is mainly challenged by the nonlinearity present in the measurement equation, and the difficulty in fast and accurate data association. To overcome these challenges, the present paper introduces a grid-based model in which the state captures target signal strengths on a known spatial grid (TSSG). This model leads to \emph{linear} state and measurement equations, which bypass data association and can afford state estimation via sparsity-aware Kalman filtering (KF). Leveraging the grid-induced sparsity of the novel model, two types of sparsity-cognizant TSSG-KF trackers are developed: one effects sparsity through $\ell_1$-norm regularization, and the other invokes sparsity as an extra measurement. Iterative extended KF and Gauss-Newton algorithms are developed for reduced-complexity tracking, along with accurate error covariance updates for assessing performance of the resultant sparsity-aware state estimators. Based on TSSG state estimates, more informative target position and track estimates can be obtained in a follow-up step, ensuring that track association and position estimation errors do not propagate back into TSSG state estimates. The novel TSSG trackers do not require knowing the number of targets or their signal strengths, and exhibit considerably lower complexity than the benchmark hidden Markov model filter, especially for a large number of targets. Numerical simulations demonstrate that sparsity-cognizant trackers enjoy improved root mean-square error performance at reduced complexity when compared to their sparsity-agnostic counterparts.Comment: Submitted to IEEE Trans. on Signal Processin

Development of Danish version of child oral-health-related quality of life questionnaires (CPQ8–10 and CPQ11–14)

<p>Abstract</p> <p>Background</p> <p>The Child Perceptions Questionnaire (CPQ) is a self-reported questionnaire developed to measure oral health-related quality of life in children. The CPQ aims to improve the description of children's oral health, while taking into consideration the importance of psychological aspects in the concept of health. The CPQ exists in two versions: the CPQ_8–10for children aged 8–10 years and the CPQ_11–14for those aged 11–14 years. The aim of this study was to develop a Danish version of the CPQ_8–10and the CPQ_11–14and to evaluate its validity for use among Danish-speaking children.</p> <p>Methods</p> <p>The instruments were translated from English into Danish in accordance with a recommended translation procedure. Afterwards, they were tested among children aged 8–10 (n = 120) and 11–14 years (n = 225). The validity was expressed by the correlation between overall CPQ scores and i) self-reported assessment of the influence of oral conditions on everyday life (not at all, very little, some, a lot, very much) and ii) the self-reported rating of oral health. Furthermore, groups of children with assumed decreased oral health-related quality of life were compared with children with healthy oral conditions. Finally, we examined the internal consistency.</p> <p>Results</p> <p>The correlation between overall CPQ scores and global assessments of the influence of oral conditions on everyday life showed Spearman correlation coefficients of 0.45, <it>P < 0.001 </it>for CPQ_8–10and 0.50, <it>P < 0.001 </it>for CPQ_11–14. The correlation between overall CPQ scores and the self-reported rating of oral health showed Spearman correlation coefficients of 0.45, <it>P < 0.001 </it>for CPQ_8–10and 0.17, P = 0.010 for CPQ_11–14.</p> <p>The median overall CPQ_8–10scores were 7 for individuals with healthy oral conditions, 5 for individuals with cleft lip and palate, and 15 for individuals with rare oral diseases. The median overall CPQ_11–14scores were 9 for individuals with healthy oral conditions, 9 for individuals with cleft lip and palate, 17.0 for individuals with rare oral diseases, and 22.0 for individuals with fixed orthodontic appliances. There were statistically significant differences between the groups of children with healthy oral conditions and each of the subgroups, except for children with cleft lip and palate.</p> <p>Chronbach'α were 0.82 for CPQ_8–10and 0.87 for CPQ_11–14.</p> <p>Conclusion</p> <p>The results of this study reveal that the Danish CPQ_8–10and CPQ_11–14, seem to be valid instruments for measuring oral health-related quality of life in children although its ability to discriminate between children with cleft lip and palate and healthy children seem to be limited.</p

Coastal shoreline change assessments at global scales

During the present era of rapid climate change and sea-level rise, coastal change science is needed at global, regional, and local scales. Essential elements of this science, regardless of scale, include that the methods are defendable and that the results are independently verifiable. The recent contribution by Almar et al.1 does not achieve either of these measures as shown by: (i) the use of an error-prone proxy for coastal shoreline and (ii) analyses that are circular and explain little of the data variance

Effect of Body Mass Index on work related musculoskeletal discomfort and occupational stress of computer workers in a developed ergonomic setup

<p>Abstract</p> <p>Background</p> <p>Work urgency, accuracy and demands compel the computer professionals to spend longer hours before computers without giving importance to their health, especially body weight. Increase of body weight leads to improper Body Mass Index (BMI) may aggravate work related musculoskeletal discomfort and occupational-psychosocial stress. The objective of the study was to find out the effect of BMI on work related musculoskeletal discomforts and occupational stress of computer workers in a developed ergonomic setup.</p> <p>Methods</p> <p>A descriptive inferential study has been taken to analyze the effect of BMI on work related musculoskeletal discomfort and occupational-psychosocial stress. A total of 100 computer workers, aged 25-35 years randomly selected on convenience from software and BPO companies in Bangalore city, India for the participation in this study. BMI was calculated by taking the ratio of the subject's height (in meter) and weight (in kilogram). Work related musculoskeletal discomfort and occupational stress of the subjects was assessed by Cornell University's musculoskeletal discomfort questionnaire (CMDQ) and occupational stress index (OSI) respectively as well as a relationship was checked with their BMI.</p> <p>Results</p> <p>A significant association (p < 0.001) was seen among high BMI subjects with their increase scores of musculoskeletal discomfort and occupational stress.</p> <p>Conclusion</p> <p>From this study, it has been concluded that, there is a significant effect of BMI in increasing of work related musculoskeletal discomfort and occupational-psychosocial stress among computer workers in a developed ergonomic setup.</p

Preoperative medical treatment in Cushing&apos;s syndrome : frequency of use and its impact on postoperative assessment : data from ERCUSYN

Background: Surgery is the definitive treatment of Cushing's syndrome (CS) but medications may also be used as a first-line therapy. Whether preoperative medical treatment (PMT) affects postoperative outcome remains controversial. Objective: (1) Evaluate how frequently PMT is given to CS patients across Europe; (2) examine differences in preoperative characteristics of patients who receive PMT and those who undergo primary surgery and (3) determine if PMT influences postoperative outcome in pituitary-dependent CS (PIT-CS). Patients and methods: 1143 CS patients entered into the ERCUSYN database from 57 centers in 26 countries. Sixty-nine percent had PIT-CS, 25% adrenal-dependent CS (ADR-CS), 5% CS from an ectopic source (ECT-CS) and 1% were classified as having CS from other causes (OTH-CS). Results: Twenty per cent of patients took PMT. ECT-CS and PIT-CS were more likely to receive PMT compared to ADR-CS (P < 0.001). Most commonly used drugs were ketoconazole (62%), metyrapone (16%) and a combination of both (12%). Median (interquartile range) duration of PMT was 109 (98) days. PIT-CS patients treated with PMT had more severe clinical features at diagnosis and poorer quality of life compared to those undergoing primary surgery (SX) (P < 0.05). Within 7 days of surgery, PIT-CS patients treated with PMT were more likely to have normal cortisol (P < 0.01) and a lower remission rate (P < 0.01). Within 6 months of surgery, no differences in morbidity or remission rates were observed between SX and PMT groups. Conclusions: PMT may confound the interpretation of immediate postoperative outcome. Follow-up is recommended to definitely evaluate surgical results

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved