The effect of serum vitamin D normalization in preventing recurrences of benign paroxysmal positional vertigo: A case-control study

Background: Benign paroxysmal positional vertigo (BPPV) is a condition with recurrent attacks in a significant proportion of patients. The present case- control study was conducted to assess the influence of serum vitamin D normalization on recurrent attacks of vitamin D deficient patients. Methods: Diagnosis of BPPV was made based on history and clinical examination and exclusion of other conditions. Serum 25-hydroxy vitamin D (25-OHD) was measured using ELISA method and a levels of < 20 ng/ml was considered a deficiency of vitamin D. Inclusion criteria were as follows: history of recurrent attacks and serum 25-OHD < 20.ng/ml. While the patients with history of trauma, surgery and chronic systemic diseases were excluded. The patients were classified into two groups: treatment and control, intermittently. Both groups received Epley rehabilitation therapy one session per week for 4 weeks but the treatment group received an additional supplement of 50.000 IU of vitamin D (cholecalciferol) weekly for two months to achieve serum 25-OHD � 30 ng/ml and the study patients were followed-up for 6 months. Results: Twenty-seven patients were allocated to each group. At baseline, serum 25-OHD was similar (10.7�2.3 vs 11.41�1.9, P=0.23). At month 2, serum 25-OHD in the treatment group increased significantly to � 30 ng/ml, whereas serum 25-OHD in the control group remained unchanged (34.2�3.3 vs 10.6 10.6�2.2 ng/ml, P=0.001). During the follow-up period, attacks of BPPV in the treatment group decreased significantly compared with the control group (14.8 vs 96.3 OR= 0.18, P=0.001). Conclusion: The findings of this study indicate that the normalization of serum vitamin D significantly reduces BPPV recurrences

A compound current limiter and circuit breaker

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB’s ability to act as a fault current limiter and a circuit breaker

Iranian version of speech, spatial, and qualities of hearing scale: A psychometric study

Evaluation of communication abilities in the elderly is crucial for activities which will be performed to improve their quality of life. A valid and reliable questionnaire is needed for assessing communication abilities. We aimed to translate and validate the speech, spatial, and qualities of hearing scale (SSQ) in Iran. The forward-backward procedure was applied to translate the questionnaire from English into Persian. After linguistic validation and pilot study, a cross-sectional study was carried out, and psychometric properties of the Iranian version of the SSQ were tested. Number of 333 elderly individuals with impaired hearing completed the questionnaire. Number 48.3 were hearing aid users and 51.7 was not. Reliability was assessed by internal consistency (Cronbach's alpha) and test-retest analysis. Exploratory factor analysis was performed for extracting factor structure of the Persian version of SSQ. Confirmatory factor analysis was performed to compare different models of factor loadings. The Mean age of participants was 62.00 years (SD=9.58 years), and the mean SSQ score was 5.1 (SD=1.2, ranged: 3.17-6.27). Reliability evaluation revealed high internal consistency and good test- retest reliability. Cronbach's alpha coefficient was 0.96 and the Pierson Correlation at test-retest analysis was 0.73 for Quality of hearing factor, 0.88 for Spatial and o.73 for Speech understanding factor. The results of exploratory factor analysis (EFA) indicated a four-factor solution for P-SSQ that jointly accounted for 52.40 of the variance observed. Confirmatory factor analysis approved the three factor solution but proposed a possible fourth factor. The Iranian version of the SSQ has acceptable psychometric properties, and it will be helpful for assessing different kinds of communication abilities in the Iranian elderly population. © 2016 Tehran University of Medical Sciences. All rights reserved

Effects of an auditory lateralization training in children suspected to central auditory processing disorder

Background and Objectives: Central auditory processing disorder (C)APD refers to a deficit in auditory stimuli processing in nervous system that is not due to higher-order language or cognitive factors. One of the problems in children with (C)APD is spatial difficulties which have been overlooked despite their significance. Localization is an auditory ability to detect sound sources in space and can help to differentiate between the desired speech from other simultaneous sound sources. Aim of this research was investigating effects of an auditory lateralization training on speech perception in presence of noise/competing signals in children suspected to (C)APD. Subjects and Methods: In this analytical interventional study, 60 children suspected to (C)APD were selected based on multiple auditory processing assessment subtests. They were randomly divided into two groups: control (mean age 9.07) and training groups (mean age 9.00). Training program consisted of detection and pointing to sound sources delivered with interaural time differences under headphones for 12 formal sessions (6 weeks). Spatial word recognition score (WRS) and monaural selective auditory attention test (mSAAT) were used to follow the auditory lateralization training effects. Results: This study showed that in the training group, mSAAT score and spatial WRS in noise (p value�0.001) improved significantly after the auditory lateralization training. Conclusions: We used auditory lateralization training for 6 weeks and showed that auditory lateralization can improve speech understanding in noise significantly. The generalization of this results needs further researches. © 2016 The Korean Audiological Society

Normalization and reliability evaluation of persian version of two-pair dichotic digits in 8 to 12-year-old children

Objectives: All subjects suspected of Central Auditory Processing Disorder (CAPD) were previously tested by free recall dichotic digits test (DDT). The study objective was normalization and reliability evaluation of two-pair DDT in 750 native Persian subjects aged 8 to 12 years. Materials: A total of 750 subjects were divided into five age groups varying between 8 years and 12 years and 11 months old. Each age group had 150 subjects. DDT was tested in free recall condition. For evaluating DDT test-retest reliability, 300 participants (60 subjects in each age group) were tested again after one month. Results: Right and left ear mean score increased from 71.68(±2.19) and 58.51(±1.71) in the 8-year-old group to 90.26(±1.96) and 88.38(±1.36) in 12-year-old group, respectively. The mean Right Ear Advantage (REA) decreased from 13.16(±2.58) in the 8-year-old group to 1.88(±2.49) in the 12-year-old group. A high stability was observed between test-retest results (P < 0.0001). Discussion: Persian version of two-pair dichotic digits exhibited proper reliability for evaluating 8 to 12-year-old subjects, and the study results can be used for evaluating the dichotic hearing function in subjects of the same age group

Meta-Analysis of Steel Fiber-Reinforced Concrete Mixtures Leads to Practical Mix Design Methodology

The analysis of hundreds of SFRC mixtures compiled from papers published over the last 20 years is reported. This paper is focused on the relationships between the size and dosage of steel fibers and the relative amounts of the constituents of SFRC mixtures. Multiple linear regression is applied to the statistical modeling of such relationships, leading to four equations that show considerable accuracy and robustness in estimating SFRC mixture proportions as a function of fiber content and dimensions, maximum aggregate size, and water-to-cement ratio. The main trends described by these equations are discussed in detail. The importance of the interactions between aggregates, supplementary cementitious materials, and fibers in proportioning SFRC mixtures, as well as implications for workability and stability, are emphasized. The simplicity of these data-driven equations makes them a valuable tool to guide the proportioning of SFRC mixtures. Their predictive performance when used together as a data-driven mix design methodology is confirmed using a validation dataset

Construction of an Interface Terminology on SNOMED CT Generic Approach and Its Application in Intensive...

Objective: To provide a generic approach for developing a domain-specific interface terminology on SNOMED CT and to apply this approach to the domain of intensive care. Methods:The process of developing an interface terminology on SNOMED CT can be regarded as six sequential phases: domain analysis, mapping from the domain con - cepts to SNOMED CT concepts, creating the SNOMED CT subset guided by the mapping, extending the subset with non-covered concepts, constraining the subset by removing irrelevant content, and deploying the subset in a terminology server. Results:The APACHE IV classification, a standard in the intensive care with 445 diagnostic categories, served as the starting point for designing the interface terminology. The majority (89.2%) of the diagnostic categories from APACHE IV could be mapped to SNOMED CT concepts and for the remaining concepts a partial match was identified. The resulting initial set of mapped concepts consisted of 404 SNOMED CT concepts. This set could be extended to 83,125 concepts if all taxonomic children of these concepts were included. Also including all concepts that are referred to in the definition of other concepts lead to a subset of 233,782 concepts. An evaluation of the interface terminology should reveal what level of detail in the subset is suitable for the intensive care domain and whether parts need further constraining. In the final phase, the interface terminology is implemented in the intensive care in a locally developed terminology server to collect the reasons for intensive care admission. Conclusions: We provide a structure for the process of identifying a domain-specific interface terminology on SNOMED CT. We use this approach to design an interface terminology on SNOMED CT for the intensive care domain. This work is of value for other researchers who intend to build a domain-specific interface terminology on SNOMED CT