Low Test Frequency Research Articles

Sub-Optimal Disease Control and Low Blood Eosinophil Testing Frequency in Chinese Adult Patients with Asthma Receiving GINA Step 4/5 Treatment: A Real-World Study.

To inform effective management strategies for severe asthma in China, this study aimed to comprehensively characterize clinical characteristics, treatment patterns, disease control status, and healthcare resource utilization among patients on GINA Step 4/5 therapies by analyzing data from the Adelphi Asthma Disease Specific Program conducted in China. All information was retrieved from medical records or collected from physicians and patients on the survey date (August-December 2018); no follow-up was conducted. Results were summarized descriptively for patients on GINA Step 4/5 therapies, who were pooled from a consecutive sample (comprising three or more consecutive patients with physician-diagnosed asthma from each participating physician) and an oversample (comprising the next two patients with physician-perceived severe asthma from each participating physician). Of the included patients (n=754), 51.5% had ever had a blood eosinophil measurement taken, 22.1% had available records for their most recent blood eosinophil measurements (68.9% of them had an elevated level ≥150 cells/µL), 39.9% had ever been tested for specific immunoglobulin E or radioallergosorbent, and 8.0% were prescribed maintenance oral corticosteroids. Asthma was not well controlled in 69.2% of patients. In the prior year, 27.1% experienced at least one severe exacerbation and 22.8% experienced at least one hospitalization (emergency visit or overnight stay) due to asthma. In Chinese patients with asthma on GINA Step 4/5 therapies, biomarker testing was underutilized, asthma was not well controlled, and severe exacerbations were not infrequent. These findings highlight the urgent need for optimized asthma management for patients on GINA Step 4/5 therapies in China.

SARS-CoV-2 Wastewater Monitoring in Thuringia, Germany: Analytical Aspects and Normalization of Results

Wastewater monitoring for SARS-CoV-2 is a valuable tool for surveillance in public health. However, reliable analytical methods and appropriate approaches for the normalization of results are important requirements for implementing state-wide monitoring programs. In times of insufficient case reporting, the evaluation of wastewater data is challenging. Between December 2021 and July 2022, we analyzed 646 samples from 23 WWTPs in Thuringia, Germany. We investigated the performance of a direct capture-based method for RNA extraction (4S-method) and evaluated four normalization methods (NH4-N, COD, Ntot, and PMMoV) in a pooled analysis using different epidemiological metrics. The performance requirements of the 4S method were well met. The method could be successfully applied to implement a state-wide wastewater monitoring program including a large number of medium and small wastewater treatment plants (<100,000 p.e) in high spatial density. Correlations between wastewater data and 7-day incidence or 7-day-hospitalization incidence were strong and independent from the normalization method. For the test positivity rate, PMMoV-normalized data showed a better correlation than data normalized with chemical markers. In times of low testing frequency and insufficient case reporting, 7-day-incidence data might become less reliable. Alternative epidemiological metrics like hospital admissions and test positivity data are increasingly important for evaluating wastewater monitoring data and normalization methods. Furthermore, future studies need to address the variance in biological replicates of wastewater.

The distribution of lipoprotein(a) in Norway: a nationwide population-based study

Abstract Background Lipoprotein(a)[Lp(a)] is shown to be a common and important risk factor for atherosclerotic cardiovascular disease (ASCVD) because of its proatherogenic and prothrombotic properties. The concentrations of Lp(a) are mainly determined by genetics, and the median value can differ by up to fourfold between ethnic groups. Nevertheless, the distribution of Lp(a) in the Norwegian population remains unknown. Aim of study: To investigate the distribution of Lp(a) levels in the Norwegian population in individuals <50 years. To investigate awareness and test frequency of Lp(a) among Norwegian doctors. Methods The study material is nationwide clinical laboratory data with ̴ 275 000 Lp(a) measurements from 185 000 unique individuals <50 years of age, measured between 2000 and 2019. The data material is restricted to individuals <50 years because we assume a low use of medication among young adults. Results Analyses based on samples from 20 597 individuals measured between 2018-2019, show that 72.3% of the individuals have Lp(a)-levels < 30 mg/dL, 8.7% have Lp(a)-levels 30-50 mg/dL and 18.9% have Lp(a)-levels > 50 mg/dL. The distribution of Lp(a)-levels are similar for men and women < 50 years. There is high consciousness of Lp(a) among cardiologists, but low test frequency among cardiologists in other workplaces than lipid clinics. Conclusion This is the first study that shows the distribution of Lp(a) in the Norwegian population, which is similar to other European distributions of Lp(a).

To Use or Not to Use a Self-monitoring of Blood Glucose System? Real-world Flash Glucose Monitoring Patterns Using a Cluster Analysis of the FGM-Japan Study.

Objective This study investigated self-monitoring of blood glucose (SMBG) adherence and flash glucose monitoring patterns using a cluster analysis in Japanese type 1 diabetes (T1D) patients with intermittently scanned continuous glucose monitoring (isCGM). Methods We measured SMBG adherence and performed a data-driven cluster analysis using a hierarchical clustering in T1D patients from Japan using the FreeStyle Libre system. Clusters were based on three variables (testing glucose frequency and referred Libre data for hyperglycemia or hypoglycemia). Patients We enrolled 209 participants. Inclusion criteria were patients with T1D, duration of isCGM use ≥3 months, age ≥20 years old, and regular attendance at the collaborating center. Results The rate of good adherence to SMBG recommended by a doctor was 85.0%. We identified three clusters: cluster 1 (low SMBG test frequency but high reference to Libre data, 17.7%), cluster 2 (high SMBG test frequency but low reference to Libre data, 34.0%), and cluster 3 (high SMBG test frequency and high reference to Libra data, 48.3%). Compared with other clusters, individuals in cluster 1 were younger, those in cluster 2 had a shorter Libre duration, and individuals in cluster 3 had lower time-in-range, higher severe diabetic distress, and high intake of snacks and sweetened beverages. There were no marked differences in the incidence of diabetic complications and rate of wearing the Libre sensor among the clusters. Conclusions We stratified the patients into three subgroups with varied clinical characteristics and CGM metrics. This new substratification might help tailor diabetes management of patients with T1D using isCGM.

Improved resonance method for fatigue test of full-scale wind turbine blades

To further reduce the power of exciter in the common fatigue testing methods and increase the testing frequency to decrease the fatigue testing time, this paper proposes an improved fatigue testing method—Tug Fatigue Testing system (TFTs). The advantages of this new fatigue testing method are low power and high testing frequency of its exciter due to no exciter with moving masses attached to the blade. In TFTs, exciters mounted on the ground or fixed bracket can be used to excite the blade in the uniaxial or biaxial fatigue test. In this paper, the mechanical model of TFTs is established to compare the motor power required by exciters in TFTs and the inertial exciters and the shear load on the blades in both ways. Furthermore, a test of a 56.5 m blade will be performed to verify the feasibility of the new method. In addition, the bending moment distribution of an 80 m blade excited by TFTs was measured and compared with the bending moment distribution of the same blade excited by inertial resonance excitation to evaluate its excitation effect. The test results prove that this improved method needs lower power of exciter, produces smaller shear loads, and provides a higher test frequency in the flap-wise test direction than common inertial resonance excitation. Biaxial fatigue tests can also be conducted by this new method.

Assessing alternative indicators for Covid-19 policy evaluation, with a counterfactual for Sweden.

Using the synthetic control method, we construct counterfactuals for what would have happened if Sweden had imposed a lockdown during the first wave of the COVID-19 epidemic. We consider eight different indicators, including a novel one that we construct by adjusting recorded daily COVID-19 deaths to account for weakly excess mortality. Correcting for data problems and re-optimizing the synthetic control for each indicator, we find that a lockdown would have had sizable effects within one week. The much longer delay estimated by two previous studies focusing on the number of positives cases is mainly driven by the extremely low testing frequency that prevailed in Sweden in the first months of the epidemic. This result appears relevant for choosing the timing of future lockdowns and highlights the importance of looking at several indicators to derive robust conclusions. We also find that our novel indicator is effective in correcting errors in the COVID-19 deaths series and that the quantitative effects of the lockdown are stronger than previously estimated.

Development of an axial loading system for fatigue testing of textile-composites at ultrasonic frequencies

Fiber-reinforced polymers are increasingly used in lightweight applications due to their high specific properties. Different polymer materials, and fiber architectures, are commercially available for structural applications. Performing fatigue experiments on all these combinations of fiber–matrix composites up to 109 cycles to mimic their typical lifetime of 15–20 years, at a low testing frequency generally in the range of 5–10 Hz in applications such as the aerospace industry, is expensive and time-consuming. In this study, a test system to investigate the very high cycle fatigue (VHCF) behavior of continuous fiber-reinforced polymers under an axial loading (tension–compression) condition is proposed. To do so, a testing system capable of applying cyclic oscillations at a frequency of 20 kHz and stress ratio, R = -1 was developed. For this investigation, the carbon fiber reinforced in Polyether-ketone-ketone (CF-PEKK) material was chosen. For visualization of the specimen oscillation-mode at 20 kHz, video-imaging using a high-speed camera (HSC) was employed. With the obtained displacement field from the HSC images and with thermography, the desired specimen response due to resonance at 20 kHz is validated.

Outcomes Associated With High- Versus Low-Frequency Laboratory Testing Among Hospitalized Children.

Previous pediatric studies have revealed substantial variation in laboratory testing for specific conditions, but clinical outcomes associated with high- versus low-frequency testing are unclear. We hypothesized that hospitals with high- versus low-testing frequency would have worse clinical outcomes. We conducted a multicenter retrospective cohort study of patients 0 to 18 years old with low-acuity hospitalizations in the years 2018-2019 for 1 of 10 common All Patient Refined Diagnosis Related Groups. We identified hospitals with high-, moderate-, and low-frequency testing for 3 common groups of laboratory tests: complete blood cell count, basic chemistry studies, and inflammatory markers. Outcomes included length of stay, 7- and 30-day emergency department revisit and readmission rates, and hospital costs, comparing hospitals with high- versus low-frequency testing. We identified 132 391 study encounters across 44 hospitals. Laboratory testing frequency varied by hospital and condition. We identified hospitals with high- (13), moderate- (20), and low-frequency (11) laboratory testing. When we compared hospitals with high- versus low-frequency testing, there were no differences in adjusted hospital costs (rate ratio 0.89; 95% confidence interval 0.71-1.12), length of stay (rate ratio 0.98; 95% confidence interval 0.91-1.06), 7-day (odds ratio 0.99; 95% confidence interval 0.81-1.21) or 30-day (odds ratio 1.01; 95% confidence interval 0.82-1.25) emergency department revisit rates, or 7-day (odds ratio 0.84; 95% confidence interval 0.65-1.25) or 30-day (odds ratio 0.91; 95% confidence interval 0.76-1.09) readmission rates. In a multicenter study of children hospitalized for common low-acuity conditions, laboratory testing frequency varied widely across hospitals, without substantial differences in outcomes. Our results suggest opportunities to reduce laboratory overuse across conditions and children's hospitals.

Comparison of Pure-Tone Thresholds and Cochlear Microphonics Thresholds in Pediatric Cochlear Implant Patients.

In adult cochlear implant patients, conventional audiometry is used to measure postoperative residual hearing which requires active listening and patient feedback. However, audiological measurements in pediatric cochlear implant patients are both challenging as well as time consuming. Intracochlear electrocochleography (ECOG) offers an objective and a time-efficient method to measure frequency-specific cochlear microphonic or difference thresholds (CM/DIF) thresholds that closely approximate auditory thresholds in adult cochlear implant patients. The correlation between CM/DIF and behavioral thresholds has not been established in pediatric cochlear implant patients. In the present study, CM/DIF thresholds were compared with audiometric thresholds in pediatric cochlear implant patients with postoperative residual hearing. Thirteen (11 unilateral and 2 bilateral) pediatric cochlear implant patients (mean age = 9.2 years ± 5.1) participated in this study. Audiometric thresholds were estimated using conventional, condition play, or visual reinforcement audiometry. A warble tone stimulus was used to measure audiometric thresholds at 125, 250, 500, 1000, and 2000 Hz. ECOG waveforms were elicited using 50-msec acoustic tone-bursts. The most apical intracochlear electrode was used as the recording electrode with an extra-cochlear ground electrode. The ECOG waveforms were analyzed to determine CM/DIF thresholds that were compared with pediatric cochlear implant patients' audiometric thresholds. The results show a significant correlation (r = 0.77, p < 0.01) between audiometric and CM/DIF thresholds over a frequency range of 125 to 2000 Hz in pediatric cochlear implant patients. Frequency-specific comparisons revealed a correlation of 0.82, 0.74, 0.69, 0.41, and 0.32 between the audiometric thresholds and CM/DIF thresholds measured at 125, 250, 500, 1000, and 2000 Hz, respectively. An average difference of 0.4 dB (±14 dB) was measured between the audiometric and CM/DIF thresholds. Intracochlear ECOG can be used to measure CM/DIF thresholds in pediatric cochlear implant patients with residual hearing in the implanted ear. The CM/DIF thresholds are similar to the audiometric thresholds at lower test frequencies and offer an objective method to monitor residual hearing in difficult-to-test pediatric cochlear implant patients.

Infectious and Autoimmune Causes of Encephalitis in Children

Encephalitis can result in neurologic morbidity and mortality in children. Newly recognized infectious and noninfectious causes of encephalitis have become increasingly important over the past decade. We retrospectively reviewed medical records from pediatric patients in Houston diagnosed with encephalitis in both an urban and rural catchment area between 2010 and 2017. We conducted an investigation to understand the etiology, clinical characteristics, and diagnostic testing practices in this population. We evaluated 231 patients who met the case definition of encephalitis, among which 42% had no recognized etiology. Among those with an identified etiology, the most common were infectious (73; 31%), including viral (n = 51; 22%), with the most frequent being West Nile virus (WNV; n = 12), and bacterial (n = 19; 8%), with the most frequent being Bartonella henselae (n = 7). Among cases of autoimmune encephalitis (n = 60; 26%), the most frequent cause was anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (n = 31). Autoimmune causes were seen more commonly in female (P < .01) patients. Testing for herpes simplex virus and enterovirus was nearly universal; testing for anti-NMDAR encephalitis, WNV, and Bartonella was less common. WNV was the most common infectious cause of encephalitis in our pediatric population despite lower testing frequency for WNV than herpes simplex virus or enterovirus. Increasing testing for anti-NMDAR encephalitis resulted in frequent identification of cases. Increased awareness and testing for WNV and Bartonella would likely result in more identified causes of pediatric encephalitis. Earlier etiologic diagnosis of encephalitides may lead to improve clinical outcomes.

Thermal Conductivity and Sound Absorption Properties of Carbon Nanotube / Foam Aluminum Composites

This article uses powder metallurgy technology to prepare foamed aluminum and carbon nanotubes (CNTs) / foamed aluminum composites. The laser thermal diffusion analyzer, thermal analyzer, and transfer function sound absorption coefficient test system were used to study the thermal conductivity and sound absorption properties of aluminum foam and its composites, respectively. The results show that the thermal conductivity of aluminum foam with 79% porosity is only 5W · m−1·K−1, which is much smaller than the thermal conductivity of aluminum. So it can be used as an ideal thermal insulation material; The thermal conductivity of carbon nanotubes (CNTs) / foamed aluminum-based composites increases first and then decreases with the increase in the mass fraction of CNTs. As the test temperature increases, the thermal conductivity of the material gradually increases. When the mass fraction of CNTs is 0.75%, the thermal conductivity of foamed aluminum-based composites reaches the maximum. As the test frequency increases, the sound absorption performance of foamed aluminum first increases, then decreases, and then gradually increases, reaching a maximum value around 1000 Hz. The sound absorption performance of CNTs / foam aluminum matrix composites decreases at lower test frequencies as the mass fraction of CNTs increases. At higher frequencies, as the mass fraction of CNTs increases, the sound absorption coefficient of foamed aluminum decreases first and then increases.

Pavement Structural Capacity from Traffic Speed Deflectometer for Network Level Pavement Management System Application

Structural number (SN) represents the structural capacity of a flexible pavement system to sustain anticipated traffic and is among the structural indices most commonly used by pavement design engineers in the U.S. Effective structural number (SNeff) is an indicator of structural capacity of in-service pavement sections and is conventionally estimated from nondestructive testing (NDT) device data such as falling weight deflectometers (FWDs) using methods such as suggested by AASHTO. In addition to pavement design, structural condition is a critical input for the selection of maintenance and rehabilitation strategies in pavement management system (PMS) application. However, use of SN in network level application has not been practical because of limitations of FWD such as stop-and-go operation, lane closures, and low testing frequency. The traffic speed deflectometer (TSD), a continuous deflection device, has recently been gaining worldwide application as a reliable NDT device for network level PMS applications. The objective of this study is to develop a practical approach to compute and utilize SN of in-service flexible pavements from TSD data for network level PMS applications. The study is based on the fundamental that, for the same pavement, SNeff from the TSD using the proposed method should be in good agreement with SNeff from the FWD using AASHTO method. The developed method was field validated with TSD and FWD data collected at in-service pavement sections. In addition, the use of structural number ratio, defined as a ratio of SNeff to required SN, in network level prioritization of structural capacity improvements was illustrated.

Does airborne ultrasound lead to activation of the auditory cortex?

As airborne ultrasound can be found in many technical applications and everyday situations, the question as to whether sounds at these frequencies can be heard by human beings or whether they present a risk to their hearing system is of great practical relevance. To objectively study these issues, the monaural hearing threshold in the frequency range from 14 to 24 kHz was determined for 26 test subjects between 19 and 33 years of age using pure tone audiometry. The hearing threshold values increased strongly with increasing frequency up to around 21 kHz, followed by a range with a smaller slope toward 24 kHz. The number of subjects who could respond positively to the threshold measurements decreased dramatically above 21 kHz. Brain activation was then measured by means of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) and with acoustic stimuli at the same frequencies, with sound pressure levels (SPLs) above and below the individual threshold. No auditory cortex activation was found for levels below the threshold. Although test subjects reported audible sounds above the threshold, no brain activity was identified in the above-threshold case under current experimental conditions except at the highest sensation level, which was presented at the lowest test frequency.

Exact coefficients for rigid dumbbell suspensions for steady shear flow material function expansions

From kinetic molecular theory, we can attribute the elasticity of polymeric liquids to macromolecular orientation. For a suspension of rigid dumbbells, subject to a particular flow field, we must first solve the diffusion equation for the orientation distribution function. From this distribution, we then calculate physical properties such as the steady shear flow material functions. We thus arrive at power series expansions in the shear rate for both the orientation distribution function and for the steady shear flow material functions. Analytical work on many viscoelastic material functions must be checked for consistency, in their steady shear flow limits, against these power series. For instance, for large-amplitude oscillatory shear flow, we recover the coefficients of these expansions in the limits of low test frequency. The coefficients of the steady shear viscosity and the first normal stress coefficient functions are not known exactly beyond the fourth power. In this work, for both of these functions, we arrive at exact expressions for the first 20 coefficients. We close with five worked examples illustrating uses for our new coefficients.

Frequency Dependence of Receiving Sensitivity of Ultrasonic Transducers and Acoustic Emission Sensors.

Receiving displacement sensitivities (Rx) of ultrasonic transducers and acoustic emission (AE) sensors are evaluated using sinewave packet excitation method and compared to the corresponding data from pulse excitation method with a particular emphasis on low frequency behavior below 20 kHz, down to 10 Hz. Both methods rely on the determination of transmitter displacement characteristics using a laser interferometric method. Results obtained by two calibration methods are in good agreement, with average spectral differences below 1 dB, indicating that the two calibration methods yield identical receiving sensitivities. At low test frequencies, effects of attenuation increase substantially due to increasing sensor impedance and Rx requires correction in order to evaluate the inherent sensitivity of a sensor, or open-circuit sensitivity. This can differ by more than 20 dB from results that used common preamplifiers with ~10 kΩ input impedance, leading to apparent velocity response below 100 kHz for typical AE sensors. Damped broadband sensors and ultrasonic transducers exhibit inherent velocity response (Type 1) below their main resonance frequency. In sensors with under-damped resonance, a steep sensitivity decrease occurs showing frequency dependence of f2~f5 (Type 2), while mass-loaded sensors exhibit flat displacement response (Type 0). Such behaviors originate from sensor characteristics that can best be described by the damped harmonic oscillator model. This model accounts for the three typical behaviors. At low frequencies, typically below 1 kHz, receiving sensitivity exhibits another Type 0 behavior of frequency independent Rx. Seven of 12 sensors showed this flat region, while three more appear to approach the Type 0 region. This appears to originate from the quasi-static piezoelectric response of a sensing element. In using impulse method, a minimum pulse duration is necessary to obtain spectral fidelity at low frequencies and an approximate rule is given. Various factors for sensitivity improvement are also discussed.

Development and Validation of a Pattern-Recognition Engine for Visualization of Glycemic Patterns in Individuals Performing Low-Frequency SMBG

Background and Aims: Innovative technologies supporting healthcare professionals (HCPs) and patients in the review of self-monitoring blood glucose (SMBG) data may aid clinical and educational approach to diabetes management. MyStar Connect® (MSC) is a diabetes data management software that helps HCPs review patient data and adjust diabetes therapy. Filtering mechanisms are needed to visualize data efficiently. We developed a pattern recognition engine (PRE) for visualization of glycemic patterns of SMBG data in MSC. Method: 3-month of SMBG data from 184 insulin- and non-insulin treated patients, at low testing frequency (0.5-2 tests per day), were independently evaluated by three expert assessors. Daily and weekly hypo- and hyperglycemic patterns were identified, and compared to those identified by the PRE. Discrepancies were reconciled through discussion between the assessors. The rate of agreement between assessors and PRE was evaluated. The analyses were conducted separately for hypoglycemic and hyperglycemic patterns. Results: Daily patterns: 56 hypoglycemic and 247 hyperglycemic patterns were identified by the PRE. No disagreement was noted in the assessment of hypoglycemic patterns between the PRE and the assessors. In 23 cases of hyperglycemic patterns, a disagreement was noted, due to the PRE missing a pattern considered as present by the assessors. After further clarification, 18 cases were reconciled. Therefore, the rate of agreement between the PRE and the assessors was 100% for hypoglycemic patterns and 98% for hyperglycemic patterns. Weekly patterns: The assessors recognized that the PRE provided information not easily inferable by simple review of SMBG data. PRE was therefore considered reliable for all the patterns identified. Conclusion: The implementation of PRE can represent a useful tool to guide HCPs’ treatment decisions and educate patients performing SMBG at a low frequency. Disclosure G. Vespasiani: Consultant; Self; METEDA Srl. Other Relationship; Spouse/Partner; METEDA Srl. A. Nicolucci: None. M. Saleh: Employee; Self; Sanofi. J. Sieber: Employee; Self; Sanofi. Stock/Shareholder; Self; Sanofi. G. Prosperini: None. C. Suraci: None. M. Galetta: None. G. Grassi: None.

Low annual frequency of HbA1c testing in people with Type 2 diabetes in primary care practices in Germany.

To analyse the annual frequency of HbA1c testing, as well as the factors associated with higher or lower testing frequency, in people with Type 2 diabetes mellitus in general practices and specialist diabetes practices in Germany. A total of 43 509 people diagnosed with Type 2 diabetes between January 2016 and December 2016 in 557 medical practices (51% of all practices) were included in this study. The primary outcome was the annual recorded frequency of HbA1c testing in 2016. Multivariable logistic regression analyses were performed to identify variables associated with the odds of HbA1c concentration being tested at least twice in 2016, using predefined demographic and clinical variables. The mean (sd) number of reported HbA1c tests was 2.7 (1.6) in 2016. Overall, 74% of individuals had at least two annual HbA1c measurements. The likelihood of receiving ≥2 HbA1c tests was inversely associated with stroke (odds ratio 0.81, 95% CI 0.74-0.89), shorter diabetes duration (≤1 year: odds ratio 0.77, 95% CI 0.70-0.84) and higher mean HbA1c concentration (≥8.5%: odds ratio 0.85, 95% CI 0.76-0.94) and was positively associated with specialist diabetes care (odds ratio 1.24, 95% CI 1.14-1.36), hypertension (odds ratio 1.10, 95% CI 1.04-1.17), hyperlipidaemia (odds ratio 1.48, 95% CI 1.41 to 1.55), renal complications (odds ratio 1.41, 95% CI 1.32 to 1.50), neuropathy (odds ratio 1.27, CI 1.20 to 1.35) and retinopathy (odds ratio 1.38, 95% CI 1.25 to 1.52). Only three out of four individuals with Type 2 diabetes underwent at least two HbA1c tests in Germany in 2016, which means that 25% of individuals underwent fewer tests than required by German guidelines.

Human Cochlear Histopathology Reflects Clinical Signatures of Primary Neural Degeneration

Auditory neuropathy is a significant and understudied cause of human hearing loss, diagnosed in patients who demonstrate abnormal function of the cochlear nerve despite typical function of sensory cells. Because the human inner ear cannot be visualized during life, histopathological analysis of autopsy specimens is critical to understanding the cellular mechanisms underlying this pathology. Here we present statistical models of severe primary neuronal degeneration and its relationship to pure tone audiometric thresholds and word recognition scores in comparison to age-matched control patients, spanning every decade of life. Analysis of 30 ears from 23 patients shows that severe neuronal loss correlates with elevated audiometric thresholds and poor word recognition. For each ten percent increase in total neuronal loss, average thresholds across patients at each audiometric test frequency increase by 6.0 dB hearing level (HL). As neuronal loss increases, threshold elevation proceeds more rapidly in low audiometric test frequencies than in high frequencies. Pure tone average closely agrees with word recognition scores in the case of severe neural pathology. Histopathologic study of the human inner ear continues to emphasize the need for non- or minimally invasive clinical tools capable of establishing cellular-level diagnoses.

Effect of frequency on fretting wear behavior of Ti/TiN multilayer film on depleted uranium.

The Ti/TiN multi-layer film was prepared on the depleted uranium (DU) substrate by cathodic arc ion plating equipment. The character of multi-layer film was studied by SEM, XRD and AES, revealed that the surface was composed of small compact particle and the cross-section had a multi-layer structure. The fretting wear performance under different frequencies was performed by a MFT-6000 machine with a ball-on-plate configuration. The wear morphology was analyzed by white light interferometer, OM and SEM with an EDX. The result shows the Ti/TiN multi-layer film could greatly improve the fretting wear performance compared to the DU substrate. The fretting wear running and damaged behavior are strongly dependent on the film and test frequency. The fretting region of DU substrate and Ti/TiN multi-layer under low test frequency is gross slip. With the increase of test frequency, the fretting region of Ti/TiN multi-layer change from gross slip to mixed fretting, then to partial slip.

Assessing Self-Control and Geosocial Networking App Behavior Among an Online Sample of Men Who Have Sex with Men.

Geosocial networking phone applications (GSN apps) used to meet sexual partners have become popular in the men who have sex with men (MSM) communities of the USA since 2009. Previous studies have shown greater incidence of gonorrhea and chlamydia and lower testing frequency for HIV testing among GSN app users when compared to non-users. The present study aims to determine the type, number, and frequency of apps used, as well as the association between dispositional self-control and health-related behaviors. Participants (n = 146) were recruited from Amazon's Mechanical Turk program to respond to a brief GSN app marketing survey. Multivariate regression was used to determine differences in app priorities, length of app use, and number of sexual partners between high self-control and low self-control participants. A majority of the participants reported using Grindr (78%) followed by Scruff (19%), Growlr (12%), and Jack'd (12%). Most individuals used one app only (58%), but a significant proportion reported using two apps (28%) or three or more apps (14%). Respondents with low self-control were more likely to report a higher number of hours using GSN apps and a higher number of sexual partners, controlling for race/ethnicity, education, employment, and HIV status. Given the popularity of this burgeoning communication medium, these findings have important implications for developing prevention resources for different segments of GSN app users.