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Journal of Communication Disorders 2023Audiometric calibration, which includes the calibration of different audiometer transducers and the measurements of ambient noise levels, is historically carried out...
Audiometric calibration, which includes the calibration of different audiometer transducers and the measurements of ambient noise levels, is historically carried out using Class 1 sound level meters. As technologies advance, many mobile applications (apps) have been developed to measure sound levels. These apps can provide alternative methods for audiometric calibration in places where sound level meters are not available, such as field testing environments, low-to-mid-income countries, and humanitarian settings. These apps, however, cannot be used for audiometric calibration without first evaluating their performance, which depends on multiple factors including the external components (if any), the operating system and the hardware of the electronic devices. The evaluation of the apps is actually the evaluation of the app and associated factors (i.e., the app systems). This paper discusses methods to assess several key functions of apps implemented in either Android or iOS operation system for audiometric calibration: 1) checking the measurement accuracy at all testing frequencies, 2) deriving and using correction factors, 3) determining the self-noise levels, and 4) evaluating the linear/measurement range. As audiometric calibration usually uses octave or 1/3 octave bands to measure sound pressure levels of tones and narrowband noises with relatively steady temporal characteristics, the accuracy of an app can be evaluated by comparing the levels measured by the app and a Class 1 sound level meter at each frequency. The level difference between the app and the Class 1 sound level meter at each frequency can then be used to calculate correction factors that can be added to subsequent levels measured by the app to improve its accuracy. In addition, methods to determine the self-noise level and the linearity range of apps are discussed. Sample measurement scenarios and alternative methods are provided to illustrate the evaluation process to determine whether an app is suitable for measuring ambient noise levels and for calibrating different audiometric transducers.
Topics: Humans; Calibration; Mobile Applications; Noise
PubMed: 37480593
DOI: 10.1016/j.jcomdis.2023.106351 -
Physical Review. E Aug 2023We study a Jarzysnki-type equality for work in systems that are monitored using nonprojective unsharp measurements. The information acquired by the observer from the...
We study a Jarzysnki-type equality for work in systems that are monitored using nonprojective unsharp measurements. The information acquired by the observer from the outcome f of an energy measurement and the subsequent conditioned normalized state ρ[over ̂](t,f) evolved up to a final time t are used to define work, as the difference between the final expectation value of the energy and the result f of the measurement. The Jarzynski equality obtained depends on the coherences that the state develops during the process, the characteristics of the meter used to measure the energy, and the noise it induces into the system. We analyze those contributions in some detail to unveil their role. We show that in very particular cases, but not in general, the effect of such noise gives a factor multiplying the result that would be obtained if projective measurements were used instead of nonprojective ones. The unsharp character of the measurements used to monitor the energy of the system, which defines the resolution of the meter, leads to different scenarios of interest. In particular, if the distance between neighboring elements in the energy spectrum is much larger than the resolution of the meter, then a similar result to the projective measurement case is obtained, up to a multiplicative factor that depends on the meter. A more subtle situation arises in the opposite case in which measurements may be noninformative, i.e., they may not contribute to update the information about the system. In this case a correction to the relation obtained in the nonoverlapping case appears. We analyze the conditions in which such a correction becomes negligible. We also study the coherences, in terms of the relative entropy of coherence developed by the evolved post-measurement state. We illustrate the results by analyzing a two-level system monitored by a simple meter.
PubMed: 37723778
DOI: 10.1103/PhysRevE.108.024126 -
Microbiology Spectrum Sep 2023The emission of methane from wetlands is spatially heterogeneous, as concurrently measured surface fluxes can vary by orders of magnitude within the span of a few...
The emission of methane from wetlands is spatially heterogeneous, as concurrently measured surface fluxes can vary by orders of magnitude within the span of a few meters. Despite extensive study and the climatic significance of these emissions, it remains unclear what drives large, within-site variations. While geophysical factors (e.g., soil temperature) are known to correlate with methane (CH) flux, measurable variance in these parameters often declines as spatial and temporal scales become finer. As methane emitted from wetlands is the direct, net product of microbial metabolisms which both produce and degrade CH, it stands to reason that characterizing the spatial variability of microbial communities within a wetland-both horizontally and vertically-may help explain observed variances in flux. To that end, we surveyed microbial communities to a depth of 1 m across an ombrotrophic peat bog in Maine, USA using amplicon sequencing and gene expression techniques. Surface methane fluxes and geophysical factors were concurrently measured. Across the first meter of peat at the site, we observed significant changes in the abundance and composition of methanogenic taxa at every depth sampled, with variance in methanogen abundance explaining 70% of flux heterogeneity at a subset of plots. Among measured environmental factors, only peat depth emerged as correlated with flux, and had significant impact on the abundance and composition of methane-cycling communities. These conclusions suggest that a heightened awareness of how microbial communities are structured and spatially distributed within wetlands could offer improved insights into predicting CH flux dynamics. IMPORTANCE Globally, wetlands are one of the largest sources of methane (CH), a greenhouse gas with a warming impact significantly greater than CO. Methane produced in wetlands is the byproduct of a group of microorganisms which convert organic carbon into CH. Despite our knowledge of how this process works, it is still unclear what drives dramatic, localized (<10 m) variance in emission rates from the surface of wetlands. While environmental conditions, like soil temperature or water table depth, correlate with methane flux when variance in these factors is large (e.g., spring vs fall), the explanatory power of these variables decline when spatial and temporal scales become smaller. As methane fluxes are the direct product of microbial activity, we profiled how the microbial community varied, both horizontally and vertically, across a peat bog in Maine, USA, finding that variance in microbial communities was likely contributing to much of the observed variance in flux.
PubMed: 37728556
DOI: 10.1128/spectrum.02714-23 -
PloS One 2023During COVID-19 pandemic several public health measures were implemented by diverse countries to reduce the risk of COVID-19, including social distancing. Here we...
During COVID-19 pandemic several public health measures were implemented by diverse countries to reduce the risk of COVID-19, including social distancing. Here we collected the minimal distance recommended by each country for physical distancing at the onset of the pandemic and aimed to examine whether it had an impact on the outbreak dynamics and how this specific value was chosen. Despite an absence of data on SARS-CoV-2 viral transmission at the beginning of the pandemic, we found that most countries recommended physical distancing with a precise minimal distance, between one meter/three feet and two meters/six feet. 45% of the countries advised one meter/three feet and 49% advised a higher minimal distance. The recommended minimal distance did not show a clear correlation with reproduction rate nor with the number of new cases per million, suggesting that the overall COVID-19 dynamics in each country depended on multiple interacting factors. Interestingly, the recommended minimal distance correlated with several cultural parameters: it was higher in countries with larger interpersonal distance between two interacting individuals in non-epidemic conditions, and it correlated with civil law systems, and with currency. This suggests that countries which share common conceptions such as civil law systems and currency unions tend to adopt the same public health measures.
Topics: Humans; COVID-19; Pandemics; SARS-CoV-2; Physical Distancing; Disease Outbreaks
PubMed: 38100502
DOI: 10.1371/journal.pone.0289998 -
Ultrasonics Sonochemistry Dec 2023Mapping of a novel 20 L capacity ultrasonic (US) reactor having a total of 44 transducers was done by measuring the local cavitation intensity using a cavitation...
Mapping of a novel 20 L capacity ultrasonic (US) reactor having a total of 44 transducers was done by measuring the local cavitation intensity using a cavitation activity meter at different horizontal planes and subsequent validation based on dye degradation. A fixed frequency of 33 kHz and temperature of 30 °C was used during the mapping performed at two different power levels of 250 W and 400 W. In addition, the mapping of specific plane 2 was also performed with transducers operating on walls 1 and 3, while switching the transducers on walls 2 and 4 off and vice versa so as to establish the role of using multiple transducers. Degradation of RO4 dye was also measured at the plane 2 at various powers as 250 W, 400 W, and 1000 W. The degradation of the RO4 dye directly correlated to the cavitation intensity measured at the various location inside the US reactor. The average cavitation intensity was 265.38, 317.25, 185, and 300.5 Cavins for power dissipations of 250 W, 400 W, 250 W (wall 1 and 3 transducers in operation), and 400 W (wall 2 and 4 transducers in operation), respectively. Correspondingly, the average degradation was 10.35 %, 13.03 %, 5.52 %, and 8.9 % for same sequence of operational power and transducers. The investigation amply illustrated dependency of the cavitational activity on the location, power dissipation, and operating mode elucidating important design related information useful for scale up of sonochemical reactors.
PubMed: 37952469
DOI: 10.1016/j.ultsonch.2023.106688 -
PloS One 2023Typically, load forecasting models are trained in an offline setting and then used to generate predictions in an online setting. However, this approach, known as batch...
Typically, load forecasting models are trained in an offline setting and then used to generate predictions in an online setting. However, this approach, known as batch learning, is limited in its ability to integrate new load information that becomes available in real-time. On the other hand, online learning methods enable load forecasting models to adapt efficiently to new incoming data. Electricity Load and Price Forecasting (ELPF) is critical to maintaining energy grid stability in smart grids. Existing forecasting methods cannot handle the available large amount of data, which are limited by different issues like non-linearity, un-adjusted high variance and high dimensions. A compact and improved algorithm is needed to synchronize with the diverse procedure in ELPF. Our model ELPF framework comprises high/low consumer data separation, handling missing and unstandardized data and preprocessing method, which includes selecting relevant features and removing redundant features. Finally, it implements the ELPF using an improved method Residual Network (ResNet-152) and the machine-improved Support Vector Machine (SVM) based forecasting engine to forecast the ELP accurately. We proposed two main distinct mechanisms, regularization, base learner selection and hyperparameter tuning, to improve the performance of the existing version of ResNet-152 and SVM. Furthermore, it reduces the time complexity and the overfitting model issue to handle more complex consumer data. Furthermore, numerous structures of ResNet-152 and SVM are also explored to improve the regularization function, base learners and compatible selection of the parameter values with respect to fitting capabilities for the final forecasting. Simulated results from the real-world load and price data confirm that the proposed method outperforms 8% of the existing schemes in performance measures and can also be used in industry-based applications.
Topics: Learning; Education, Distance; Algorithms; Computer Systems; Support Vector Machine
PubMed: 37851626
DOI: 10.1371/journal.pone.0289672 -
Nutrients Nov 2023The Veggie Meter (Longevity Link Corporation, Salt Lake City, UT, USA), is a new portable device for the non-invasive and rapid detection of skin carotenoid content,...
The Veggie Meter (Longevity Link Corporation, Salt Lake City, UT, USA), is a new portable device for the non-invasive and rapid detection of skin carotenoid content, which represents an acceptable biomarker for the evaluation of fruit and vegetable (FV) intake. FVs are important components of a healthy diet, including the Mediterranean Diet (MD), which is a plant-based dietary pattern. Here, we evaluated the adherence to the MD via the administration of two online food questionnaires, and we measured the skin carotenoid content using the Veggie Meter in a cohort of 498 healthy adolescents (233 males and 265 females) from Southern Italy. Using KIDMED and the MD Pyramid tests to assess the adherence to the MD, we found an average adherence (5.43 ± 2.57 and 7.20 ± 1.93, respectively) to the MD in our sample population. Moreover, we observed that the skin carotenoid score was 364.75 ± 98.29, which was within the normal range and inversely related to the BMI (r = -0.1461, = 0.0011). Similar results were observed when the population was categorized by sex. Interestingly, we demonstrated, for the first time, a positive correlation between the carotenoid score and the adherence to the MD assessed using both the KIDMED and MD Pyramid tests in the total population (r = -0.2926, < 0.0001 and r = -0.1882, < 0.0001, respectively). The same direct correlation was found in adolescents according to their sex. Our findings highlight the potential of the Veggie Meter as a feasible and promising tool for evaluating adherence to the MD and, ultimately, to promote healthy eating habits among adolescents.
Topics: Male; Female; Humans; Adolescent; Diet, Mediterranean; Vegetables; Italy; Diet, Healthy; Feeding Behavior; Carotenoids
PubMed: 38068778
DOI: 10.3390/nu15234920 -
PLoS Neglected Tropical Diseases Jul 2023Snake bite envenoming (SBE) is one neglected tropical disease that has not received the needed attention. The sequelae of burdensome disability and mortality impact the...
BACKGROUND
Snake bite envenoming (SBE) is one neglected tropical disease that has not received the needed attention. The sequelae of burdensome disability and mortality impact the socioeconomic life of communities adversely with little documentation of SBE in health facility records in Ghana. This study details SBE and snake distribution, habits/habitats, type of venom expressed and clinical manifestations.
METHODOLOGY
We conducted a structured thematic desk review of peer reviewed papers, books and reports from repositories including PubMed, World Health Organization (WHO) and Women's & Children's Hospital (WCH) Clinical Toxinology Resources using bibliographic software EndNote and search engine Google Scholar with the following key words; snakes, medical importance, snake bites, venom and venom type, envenomation, symptoms and signs, vaccines, venom expenditure, strike behaviour and venom-metering + Ghana, West Africa, Africa, World. We also reviewed data from the District Health Information Management System (DHIMS) of the Ghana Health Service (GHS). Outcome variables were organized as follows: common name (s), species, habitat/habit, species-specific toxin, clinical manifestation, antivenom availability, WHO category.
FINDINGS
Snake bites and SBE were grouped by the activity of the expressed venom into neurotoxic, cardiotoxic, haemorrhagic, cytotoxic, myotoxic, nephrotoxic and procoagulants. Neurotoxic snake bites were largely due to elapids. Expressed venoms with cardiotoxic, haemorrhagic, nephrotoxic and procoagulant activities principally belonged to the family Viperidae. Snakes with venoms showing myotoxic activity were largely alien to Ghana and the West African sub-region. Venoms showing cytotoxic activity are expressed by a wide range of snakes though more prevalent among the Viperidae family. Snakes with neurotoxic and haemorrhagic venom activities are prevalent across all the agro-ecological zones in Ghana.
CONCLUSION/SIGNIFICANCE
Understanding the characteristics of snakes and their venoms is useful in the management of SBE. The distribution of snakes by their expressed venoms across the agro-ecological zones is also instructive to species identification and diagnosis of SBE.
Topics: Animals; Antivenins; Elapid Venoms; Elapidae; Ghana; Snake Bites; Snake Venoms; Snakes; Viperidae
PubMed: 37506181
DOI: 10.1371/journal.pntd.0011050 -
Clinical Ophthalmology (Auckland, N.Z.) 2023With the increasing prevalence of myopia, evaluating its relationship with objective light exposure as a potential adjustable environmental factor in myopia development... (Review)
Review
With the increasing prevalence of myopia, evaluating its relationship with objective light exposure as a potential adjustable environmental factor in myopia development has been an emerging research field in recent years. From a thorough literature search, we identify ten wearable light meters from human studies on light exposure and myopia and present an overview of their parameters, thereby demonstrating the wide between-device variability and discussing its implications. We further identify 20 publications, including two reanalyses, reporting investigations of light-myopia associations with data from human subjects wearing light meters. We thoroughly review the publications with respect to general characteristics, aspects of data collection, participant population, as well as data analysis and interpretation, and also assess potential patterns regarding the absence or presence of light-myopia associations in their results. In doing so, we highlight areas in which more research is needed as well as several aspects that warrant consideration in the study of light exposure and myopia.
PubMed: 37743889
DOI: 10.2147/OPTH.S420631 -
Philosophical Transactions of the Royal... May 2024Many animals have pigments when they themselves cannot see colour. Perhaps those pigments enable the animal to avoid predators, or to attract mates. Maybe even those... (Review)
Review
Many animals have pigments when they themselves cannot see colour. Perhaps those pigments enable the animal to avoid predators, or to attract mates. Maybe even those pigmented surfaces are hosts for microbes, even when the microbes do not see colour. Do some pigments then serve as a chemical signal for a good or bad microbial substrate? Maybe pigments attract or repel various microbe types? Echinoderms serve as an important model to test the mechanisms of pigment-based microbial interactions. Echinoderms are marine benthic organisms, ranging from intertidal habitats to depths of thousands of metres and are exposed to large varieties of microbes. They are also highly pigmented, with a diverse variety of colours between and even within species. Here we focus on one type of pigment (naphthoquinones) made by polyketide synthase, modified by flavin-dependent monoxygenases, and on one type of function, microbial interaction. Recent successes in targeted gene inactivation by CRISPR/Cas9 in sea urchins supports the contention that colour is more than it seems. Here we dissect the players, and their interactions to better understand how such host factors influence a microbial colonization. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
Topics: Animals; Microbiota; Pigmentation
PubMed: 38497266
DOI: 10.1098/rstb.2023.0077