198 research outputs found
Multipath Separation-Direction of Arrival (MS-DOA) with Genetic Search Algorithm for HF channels
Cataloged from PDF version of article.Direction-of-Arrival (DOA) defines the estimation of arrival angles of an electromagnetic wave impinging on a set of sensors. For
dispersive and time-varying HF channels, where the propagating wave also suffers from the multipath phenomena, estimation of
DOA is a very challenging problem. Multipath Separation-Direction of Arrival (MS-DOA), that is developed to estimate both the arrival
angles in elevation and azimuth and the incoming signals at the output of the reference antenna with very high accuracy, proves itself as a
strong alternative in DOA estimation for HF channels. In MS-DOA, a linear system of equations is formed using the coefficients of the
basis vector for the array output vector, the incoming signal vector and the array manifold. The angles of arrival in elevation and azimuth
are obtained as the maximizers of the sum of the magnitude squares of the projection of the signal coefficients on the column space of the
array manifold. In this study, alternative Genetic Search Algorithms (GA) for the maximizers of the projection sum are investigated
using simulated and experimental ionospheric channel data. It is observed that GA combined with MS-DOA is a powerful alternative
in online DOA estimation and can be further developed according to the channel characteristics of a specific HF link.
(C) 2009 COSPAR. Published by Elsevier Ltd. All rights reserve
Diagnosis of obstructive sleep apnea with respiratory polygraph in hypercapnic ICU patients
Waterborne Outbreak of Gastroenteritis: Effects on Sick Leaves and Cost of Lost Workdays
We examined the acute and cumulative effects of this incidence on sick leaves among public sector employees residing in the clean and contaminated areas, and the additional costs of lost workdays due to the incidence.Daily information on sick leaves of 1789 Finnish Public Sector Study participants was obtained from employers' registers. Global Positioning System-coordinates were used for linking participants to the clean and contaminated areas. Prevalence ratios (PR) for weekly sickness absences were calculated using binomial regression analysis. Calculations for the costs were based on prior studies.Among those living in the contaminated areas, the prevalence of participants on sick leave was 3.54 (95% confidence interval (CI) 2.97–4.22) times higher on the week following the incidence compared to the reference period. Those living and working in the clean area were basically not affected, the corresponding PR for sick leaves was 1.12, 95% CI 0.73–1.73. No cumulative effects on sick leaves were observed among the exposed. The estimated additional costs of lost workdays due to the incidence were 1.8–2.1 million euros.The prevalence of sickness absences among public sector employees residing in affected areas increased shortly after drinking water distribution system was contaminated, but no long-term effects were observed. The estimated costs of lost workdays were remarkable, thus, the cost-benefits of better monitoring systems for the water distribution systems should be evaluated
Dexmedetomidine reduces the incidence of fentanyl-induced cough: A double-blind, randomized, and placebo-controlled study
Demographic and microbial characteristics of extrapulmonary tuberculosis cases diagnosed in Malatya, Turkey, 2001-2007
<p>Abstract</p> <p>Background</p> <p>Extrapulmonary tuberculosis (EPTB) has an increasing rate in Turkey. The reason remains largely unknown. A better understanding of the demographic and microbial characteristics of EPTB in the Turkish population would extend the knowledgebase of EPTB and allow us to develop better strategies to control tuberculosis (TB).</p> <p><b>Methods</b></p> <p>We retrospectively evaluated clinical and laboratory data of 397 bacteriologically-confirmed TB cases diagnosed during an eight year-period using by chi-square analysis and multivariate logistic regression model.</p> <p>Results</p> <p>Of the 397 study patients, 103 (25.9%) had EPTB and 294 (74.1%) had pulmonary tuberculosis (PTB). The most commonly seen two types of EPTB were genitourinary TB (27.2%) and meningeal TB (19.4%). TB in bone/joints, pleural cavity, lymph nodes, skin, and peritoneal cavity occurred at a frequency ranging from 9.7% to 10.7%. The age distribution was significantly different (P < 0.01) between PTB and EPTB, with patients older than 45 years tending to have an increased risk of EPTB. Furthermore, the distribution of different types of EPTB differed significantly among age groups (P = 0.03). Meningeal and bone and/or joint TB were more commonly observed among the male patients, while lymphatic, genitourinary, and peritoneal TB cases were more frequently seen among females. Unique strain infection was statistically significantly associated with EPTB (OR: 2.82, 95% CI [1.59, 5.00])</p> <p>Conclusions</p> <p>EPTB accounted for a significant proportion of TB cases in Malatya, Turkey between 2001 and 2007. The current study has provided an insight into the dynamics of EPTB in Malatya, Turkey. However, the risk factors for having EPTB in Malatya, Turkey remain to be assessed in future studies using population-based or randomly selected sample.</p
Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study
Introduction: Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs). Methods: We conducted a point prevalence study involving 128 PICUs in 26 countries across 6 continents. Over the course of 5 study days, 6925 PICU patients <18 years of age were screened, and 706 with severe sepsis defined either by physician diagnosis or on the basis of 2005 International Pediatric Sepsis Consensus Conference consensus criteria were enrolled. The primary endpoint was agreement of pediatric severe sepsis between physician diagnosis and consensus criteria as measured using Cohen's ?. Secondary endpoints included characteristics and clinical outcomes for patients identified using physician diagnosis versus consensus criteria. Results: Of the 706 patients, 301 (42.6 %) met both definitions. The inter-rater agreement (? ± SE) between physician diagnosis and consensus criteria was 0.57 ± 0.02. Of the 438 patients with a physician's diagnosis of severe sepsis, only 69 % (301 of 438) would have been eligible to participate in a clinical trial of pediatric severe sepsis that enrolled patients based on consensus criteria. Patients with physician-diagnosed severe sepsis who did not meet consensus criteria were younger and had lower severity of illness and lower PICU mortality than those meeting consensus criteria or both definitions. After controlling for age, severity of illness, number of comorbid conditions, and treatment in developed versus resource-limited regions, patients identified with severe sepsis by physician diagnosis alone or by consensus criteria alone did not have PICU mortality significantly different from that of patients identified by both physician diagnosis and consensus criteria. Conclusions: Physician diagnosis of pediatric severe sepsis achieved only moderate agreement with consensus criteria, with physicians diagnosing severe sepsis more broadly. Consequently, the results of a research study based on consensus criteria may have limited generalizability to nearly one-third of PICU patients diagnosed with severe sepsis
Neonatal outcome following new assisted reproductive technology regulations in Turkey-a nationwide multicenter point prevalence study
PubMed ID: 24670237Objective: In March 2010, a new legislation about assisted reproductive technology (ART) activities, favoring single embryo transfer, was introduced in Turkey. Consequences of new regulations on neonatal outcome have not been evaluated in multicenter studies yet. In this study, our aim was to evaluate neonatal outcome of infants from medically assisted reproduction (MAR) pregnancies in the post-legislation era. Methods: A point prevalence study was conducted at 51 centers in Turkey on 1 April 2013. Data about fertility treatments and neonatal characteristics were evaluated for "live births" (Group 1) and "patients being cared in the NICU" (Group 2). Results: Seventeen (4%) of 420 infants in group 1, and 89 (8.1%) of 1094 infants in group 2 were born after MAR pregnancies. The ratio of multiple births in MAR pregnancies was still very high as 47.1% for group 1, 69.1% for group 2 infants. MAR babies constituted 9.9% of infants in Level 3 NICUs and 7.6% infants in Level 2 NICUs. MAR was associated with increased risk of multiple births and prematurity. Conclusions: After the new legislation, multiple birth rates are still high in MAR pregnancies, resulting in unfavorable neonatal outcomes. Efforts to decrease multiple birth rates should be encouraged. © 2014 Informa UK Ltd. All rights reserved
Performance analysis of multiconverter unified power quality conditioner with an EPLL-based controller at medium voltage level
In this paper, one of the known interline custom power devices named Multiconverter Unified Power Quality Conditioner (MCUPQC) is designed for medium voltage level (11 kV) and improved for various power quality disturbances. An effective enhanced phase-locked loop-based control technique is applied to detect and extract the power quality disturbances for each phase separately. The performance of series compensators of MCUPQC is evaluated through extensive simulations for mitigating unbalanced voltage sags with phase jumps, swell, and interruption. Presag compensation method, which includes a novel phase-freezing algorithm, is preferred for sensitive load to mitigate the impact of phase angle jumps. The performance of shunt compensator of MCUPQC is tested for harmonic compensation, reactive power compensation, and direct current link voltage regulation. It is verified that MCUPQC, which is connected to two feeders, can compensate current and voltage imperfections successfully in these feeders according to the results obtained using PSCAD/EMTDC. Copyright © 2016 John Wiley & Sons, Ltd
Investigation of Antibacterial Activity and Biofilm Formation of Silicones Coated With Minocycline-Rifampicin, Silver Nitrate, and Nitrofurantoin for Short-term Utilization in In Vitro Urinary System Models
PMID = 2652297
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