Quantitative and graphic acoustic analysis of phonatory modulations: the modulogram.

A method is presented for analyzing phonatory instabilities that occur as modulations of fundamental frequency (f0) and sound pressure level (SPL) on the order of 0.2 to 20 cycles per second. Such long-term phonatory instabilities, including but not limited to traditional notions of tremor, are distinct from cycle-to-cycle perturbation such as jitter or shimmer. For each of the 2 parameters (f0, in Hz, and SPL, in dB), 3 frequency domains are proposed: (a) flutter (10-20 Hz), (b) tremor (2-10 Hz), and (c) wow (0.2-2.0 Hz), yielding 6 types of instability. Analyses were implemented using fast Fourier transforms (FFTs) with domain-specific analysis parameters. Outputs include a graphic display in the form of a set of low-frequency spectrograms (the "modulogram") and quantitative measures of the frequencies, magnitudes, durations, and sinusoidal form of the instabilities. An index of a given instability is developed by combining its duration and average modulation magnitude into a single quantity. Performance of the algorithms was assessed by analyzing test signals with known degrees of modulation, and a range of applications was reviewed to provide a rationale for use of modulograms in phonatory assessment.     

David and Goliath - the slingshot that started the neuropeptide revolution

This review in honor of David de Wied summarizes the work done in my laboratory that first indicated that adrenocorticotropic hormone (ACTH) has a direct effect on the neuromuscular system. Cold stress or ACTH and its related peptides alpha-melanocyte-stimulating hormone (alpha-MSH ) and beta-lipotropin improve the electromechanical characteristics of adrenalectomized and hypophysectomized rats. ACTH-(1-39) accelerates the return of motor and sensory function and improves the morphological characteristics of the motor endplate after peripheral nerve crush. The non-corticotropic fragments ACTH-(4-10), alpha-MSH, the ACTH-(4-9) analogue Organon 2766 (Org 2766) or the ACTH-(4-10) analogue Biomeasure 22015 (BIM 22015) improve electrophysiological and morphological parameters of the regenerating neuromuscular system. ACTH-(4-10) immunoreactivity, present in ventral horn motor neurons in low levels, is decreased ipsilaterally following ipsilateral nerve crush but increases both ipsilaterally and contralaterally if injured animals are treated with ACTH-(4-10) indicating a neuroprotective action. Similarly, Org 2766 appears to have a protective action in the brain following nigrostriatal lesions. In developmental studies, perinatal exposure to ACTH peptides improves the structure of the neuromuscular junction, accelerates the maturation of electromechanical properties and enhances nerve-muscle integration and nerve regeneration. Perinatal exposure to these peptides decreases adult male sexual behavior, a change correlated with increased serotinergic input within the medial preoptic area. Similar changes occur in female rats and appear to be long-lasting. In tissue culture studies, both Org 2766 and BIM 22015 promote neurite outgrowth in the absence of nerve growth factor, indicating a neurotrophic role for these peptides.     

A comparison of two methods of labelling autologous platelets with 111In-oxine in five different species

Several different methods for labelling autologous platelets with ¹¹¹In-oxine have been described. However, no comparative study has been reported.In the present investigation two different labelling methods were compared in terms of labelling efficiency and platelet function in five species: human, dog, pig, rabbit and rat.One of the labelling methods, utilising among other things a serum albumin gradient separation of platelets and incubation of ¹¹¹In-oxine in a water bath at 37° C, was superior in all species with significantly higher labelling efficiency and unchanged platelet function.     

Severe vitamin D-deficiency and the health of North China children

Objectives : To determine the health and nutritional status of rural Chinese children ages 12–24 months. Methods: This study used a cross-sectional design with a longitudinal component. Anthropometry and blood chemistry were measured on each child twice (n = 250). Caretaker knowledge and behaviors that relate to the child’s health and diet were evaluated by interview. Results: Children were taken outdoors at an average age of 131.8 days. 65.3% of surveyed children had serum 25-OH-D levels less than 12 ng/ml in the spring. This declined to 2.8% in the fall. Mean blood lead levels were 15.7 ± 11.0 μg/dl in the spring declining to 12.4 ± 12.5 μg/dl in the fall (t = 6.47, P = 0.000). This still left 63.5 and 54.9% of the children with toxic blood lead levels in spring and fall. Rates of respiratory disease declined significantly from spring to fall. A summer outdoors remarkably improved vitamin D-deficiency and lead toxicity. However, nutritional status worsened as during the summer diet was unable to keep up with growth and increased nutritional demand. From spring to fall serum zinc declined from 0.77 ± 0.19 to 0.66 ± 0.21 μg/ml (t = 3.33, P = 0.001) and blood hemoglobin declined from 12.5 ± 1.2 to 12.0 ± 1.2 gm/dl (t = 4.07, P = 0.000). Conclusions: Northern climate and cloistering of children creates a host of health risks for north China children. Vitamin D-deficiency, lead poisoning and respiratory disease are significantly worse during the winter months. These children need vitamin D supplementation during the winter and improved overall nutritional status during the summer to maintain ideal growth and development.     

Regression calibration for models with two predictor variables measured with error and their interaction,using instrumental variables and longitudinal data

Regression calibration provides a way to obtain unbiased estimators of fixed effects in regression models when one or more predictors are measured with error. Recent development of measurement error methods has focused on models that include interaction terms between measured‐with‐error predictors, and separately, methods for estimation in models that account for correlated data. In this work, we derive explicit and novel forms of regression calibration estimators and associated asymptotic variances for longitudinal models that include interaction terms, when data from instrumental and unbiased surrogate variables are available but not the actual predictors of interest. The longitudinal data are fit using linear mixed models that contain random intercepts and account for serial correlation and unequally spaced observations. The motivating application involves a longitudinal study of exposure to two pollutants (predictors) – outdoor fine particulate matter and cigarette smoke – and their association in interactive form with levels of a biomarker of inflammation, leukotriene E4 (LTE ₄, outcome) in asthmatic children. Because the exposure concentrations could not be directly observed, we used measurements from a fixed outdoor monitor and urinary cotinine concentrations as instrumental variables, and we used concentrations of fine ambient particulate matter and cigarette smoke measured with error by personal monitors as unbiased surrogate variables. We applied the derived regression calibration methods to estimate coefficients of the unobserved predictors and their interaction, allowing for direct comparison of toxicity of the different pollutants. We used simulations to verify accuracy of inferential methods based on asymptotic theory. Copyright © 2013 John Wiley & Sons, Ltd.     

YouTube as a source of medical information on the novel coronavirus 2019 disease (COVID-19) pandemic

ABSTRACT

Media coverage on coronavirus disease 2019 (COVID-19) has been extensive, yet large gaps remain in our understanding of the role of social media platforms during worldwide health crisis. The purpose of this study was to assess the most viewed YouTube videos on COVID-19 for medical content. We coded video characteristics, source, and medical content of the 113 most-widely viewed videos about COVID-19. Seventy-nine (69.9%) videos were classified as useful, and 10 (8.8%) videos were classified as misleading. Independent users were more likely to post misleading videos than useful videos (60.0% vs 21.5%, P?=?0.009). News agencies were more likely to post useful videos than misleading videos (72.2% vs 40.0%, P?=?0.039). Useful videos were more likely to present any information on prevalence or incidence (79.7% vs 20.0%, P?<?0.001), as well as information on outcomes or prognosis (84.8% vs 30.0%, P?<?0.001) compared to misleading videos. The World Health Organization contributed one useful video (1.3%), while no videos from the Center for Disease Control were included. Although YouTube generally is a useful source of medical information on the COVID-19 pandemic, increased efforts to disseminate accurate information from reputable sources is desired to help mitigate disease spread and decrease unnecessary panic in the general population.