Validity and reliability of the Child Perceptions Questionnaires applied in Brazilian children

<p>Abstract</p> <p>Background</p> <p>The Child Perceptions Questionnaires (CPQ_8–10and CPQ_11–14) are indicators of child oral health-related quality of life. The aim of this study was to assess the validity and reliability of the self-applied CPQ_8–10and CPQ_11–14in Brazilian children, after translations and cultural adaptations in the Brazilian Portuguese language.</p> <p>Methods</p> <p>Schoolchildren were recruited from general populations for pre-testing (n = 80), validity (n = 210), and test-retest reliability (n = 50) studies. They were also examined for dental caries, gingivitis, fluorosis, and malocclusion.</p> <p>Results</p> <p>Children with greater dental caries experience in primary dentition had higher impacts on CPQ domains. Girls had higher scores for CPQ_8–10domains than boys. Mean CPQ_11–14scores were highest for 11-year-old children and lowest for 14-year-old children. Construct validity was supported by significant associations between the CPQ_8–10and CPQ_11–14scores and the global rating of oral health (r = 0.38, r = 0.43) and overall well-being (r = 0.39, r = 0.60), respectively. The Cronbach's alpha was 0.95 for both questionnaires. The test-retest reliabilities of the overall CPQ_8–10and CPQ_11–14scores were both excellent (ICC = 0.96, ICC = 0.92).</p> <p>Conclusion</p> <p>The Brazilian Portuguese version of CPQ_8–10and CPQ_11–14was valuable and reliable for use in the Brazilian child population, although discriminant validity was sporadic due to the fact that impacts are mediated by others factors, such personal, social, and environmental variables.</p

Is any landmark reliable in vertebral enumeration? A study of 3.0-Tesla lumbar MRI comparing skeletal, neural, and vascular markers

Purpose: This study aimed to determine the reliability of the iliolumbar ligament (ILL), 12th costa, aortic bifurcation (AB), Tight renal artery (RRA), and conus medullaris (CM) for numbering of vertebral segments. Subjects and methods: Five hundred five patients underwent routine lumbar MRI examinations including a cervicothoracic sagittal scout and T1 and T2-weighted sagittal and axial turbo spin echo images. Images were evaluated by two radiologists separately. Results: The identifiability of ILL and 12th costa were 85.7% and 48.1%. AB, RRA, and CM were located more caudally in lumbarized S1 and more cranially in sacralized L5 cases. Conclusion: Landmarks suggested by previous studies are not reliable alternatives to cervicothoracic scout images due to wide ranges of distribution and inconsistencies in identification. (C) 2014 Elsevier Inc. All rights reserved

Deterministic multiuser carrier-frequency offset estimation for interleaved OFDMA uplink

In orthogonal frequency-division multiple access (OFDMA), closely spaced multiple subcarriers are assigned to different users for parallel signal transmission. An interleaved subcarrier-assignment scheme is preferred because it provides maximum frequency diversity and increases the capacity in frequency-selective fading channels. The subcarriers are overlapping, but orthogonal to each other such that there is no intercarrier interference (ICI). Carrier-frequency offsets (CFOs) between the transmitter and the receiver destroy the orthogonality and introduces ICI, resulting in multiple-access interference. This paper exploits the inner structure of the signals for CFO estimation in the uplink of interleaved OFDMA systems. A new uplink signal model is presented, and an estimation algorithm based on the signal structure is proposed for estimating the CFOs of all users using only one OFDMA block. Diversity schemes are also presented to improve the estimation performance. Simulation results illustrate the high accuracy and efficiency of the proposed algorithm