Effects of Hearing Aid Amplification on the Ability of Individuals With Hearing Loss to Perceive Spectral Information

Individuals with sensorineural hearing loss often struggle to understand speech even with the use of hearing aids; simply making sounds louder is not enough. Listeners decode various speech sounds with the help of spectral information, but how hearing aid amplification affects individuals’ ability to perceive those cues is not currently well understood. Altering the way hearing aids are programmed to provide amplification can potentially improve the ability of listeners with sensorineural hearing loss to access spectral information. The purpose of this study was to quantify the effects that hearing aid amplification has on the perception of spectral cues. Outcomes could help clinicians select hearing aid prescriptions that improve the adult listener’s ability to perceive spectral cues in speech. Participants with sensorineural hearing loss (normal middle ear function) were tested in aided conditions including alteration of compression channels (4, 8, and 16). Psychophysical tuning curves were collected from each participant, with a target frequency of 2 kHz and a presentation level of 10 dB SL in reference to a threshold obtained in quiet conditions. Data were compared to psychophysical tuning curves collected from participants with normal hearing. We hypothesized that the 16-channel condition would produce psychophysical tuning curves that matched the normal hearing individuals’ psychophysical tuning curves most accurately; an increased number of compression channels would provide better audibility across all frequencies, thereby improving access to spectral information. Indeed, as the number of compression channels was increased, the low-frequency side of the psychophysical tuning curves showed improvement

A Genome Sequence of Oceanimonas doudoroffii ATCC 27123T

Oceanimonas doudoroffii ATCC 27123T is an obligately aerobic Gram-negative rod of the class Gammaproteobacteria. It was first isolated from surface seawater off the coast of Oahu, HI, USA, in 1972. The predicted genome size is 3,832,938 bp (G+C content, 60.03%), which contains 3,524 predicted coding sequences

Draft Genome Sequence of the Marine Bacterium Oceanimonas baumannii ATCC 700832T

The aerobic phenol-degrading Gram-negative rod Oceanimonas baumannii ATCC 700832T was first isolated from estuary mud from the River Wear, United Kingdom, in 1983. Information on the draft genome sequence for O. baumannii ATCC 700832T is included in this announcement. The predicted genome size is 3,809,332 bp, with 55.88% G+C content

Review of the Utah Snow Load Study

Proper consideration of snow loads in building design can be a delicate balancing act: Underestimates lead to structure failure Overestimates lead to increased construction cost

TXNL6 Is a Novel Oxidative Stress-Induced Reducing System for Methionine Sulfoxide Reductase A Repair of α-Crystallin and Cytochrome C in the Eye Lens

A key feature of many age-related diseases is the oxidative stress-induced accumulation of protein methionine sulfoxide (PMSO) which causes lost protein function and cell death. Proteins whose functions are lost upon PMSO formation can be repaired by the enzyme methionine sulfoxide reductase A (MsrA) which is a key regulator of longevity. One disease intimately associated with PMSO formation and loss of MsrA activity is age-related human cataract. PMSO levels increase in the eye lens upon aging and in age-related human cataract as much as 70% of total lens protein is converted to PMSO. MsrA is required for lens cell maintenance, defense against oxidative stress damage, mitochondrial function and prevention of lens cataract formation. Essential for MsrA action in the lens and other tissues is the availability of a reducing system sufficient to catalytically regenerate active MsrA. To date, the lens reducing system(s) required for MsrA activity has not been defined. Here, we provide evidence that a novel thioredoxin-like protein called thioredoxin-like 6 (TXNL6) can serve as a reducing system for MsrA repair of the essential lens chaperone α-crystallin/sHSP and mitochondrial cytochrome c. We also show that TXNL6 is induced at high levels in human lens epithelial cells exposed to H2O2-induced oxidative stress. Collectively, these data suggest a critical role for TXNL6 in MsrA repair of essential lens proteins under oxidative stress conditions and that TXNL6 is important for MsrA defense protection against cataract. They also suggest that MsrA uses multiple reducing systems for its repair activity that may augment its function under different cellular conditions

Comparing Design Ground Snow Load Prediction in Utah and Idaho

Snow loads in the western United States are largely undefined due to complex geography and climates, leaving the individual states to publish detailed studies for their region, usually through the local Structural Engineers Association (SEAs). These associations are typically made up of engineers not formally trained to develop or evaluate spatial statistical methods for their regions and there is little guidance from ASCE 7. Furthermore, little has been written to compare the independently developed design ground snow load prediction methods used by various western states. This paper addresses this topic by comparing the accuracy of a variety of spatial methods for predicting 50-year (i.e., design) ground snow loads in Utah and Idaho. These methods include, among others, the current Utah snow load equations, Idaho’s normalized ground snow loads based on inverse distance weighting, two forms of kriging, and the authors’ adaptation of the Parameter-elevation Relationships on Independent Slopes Model (PRISM). The accuracy of each method is evaluated by measuring the mean absolute error using 10-fold cross validation on data sets obtained from Idaho’s 2015 snow load report, Utah’s 1992 snow load report, and a new Utah ground snow load data set. These results show that regression-based kriging and PRISM methods have the lowest cross-validated errors across all three data sets. These results also show that normalized ground snow loads, which are a common way of accounting for elevation in traditional interpolation methods, do not fully account for the effect of elevation on ground snow loads within the considered data sets. The methodologies and cautions outlined in this paper provide a framework for an objective comparison of snow load estimation methods for a given region as state SEAs look to improve their future design ground snow predictions. Such comparisons will aid states looking to amend or improve their current ground snow load requirements

Effects of audibility and multichannel wide dynamic range compression on consonant recognition for listeners with severe hearing loss

Objective—This study examined the effects of multichannel wide-dynamic range compression (WDRC) amplification and stimulus audibility on consonant recognition and error patterns. Design—Listeners had either severe or mild-to-moderate sensorineural hearing loss. Each listener was monaurally fit with a wearable hearing aid using typical clinical procedures, frequency-gain parameters and a hybrid of clinically prescribed compression ratios for DSL (Scollie et al., 2005) and NAL-NL (Dillon, 1999). Consonant-vowel nonsense syllables were presented in soundfield at multiple input levels (50, 65, 80 dB SPL). Test conditions were four-channel fast-acting WDRC amplification and a control compression limiting (CL) amplification condition. Listeners identified the stimulus heard from choices presented on an on-screen display. A between-subject repeated measures design was used to evaluate consonant recognition and consonant confusion patterns. Results—Fast-acting WDRC provided a considerable audibility advantage at 50 dB SPL, especially for listeners with severe hearing loss. Listeners with mild-to-moderate hearing loss received less audibility improvement from the fast-acting WDRC amplification, for conversational and high level speech, compared to listeners with severe hearing loss. Analysis of WDRC benefit scores revealed that listeners had slightly lower scores with fast-acting WDRC amplification (relative to CL) when WDRC provided minimal improvement in audibility. The negative effect was greater for listeners with mild-to-moderate hearing loss compared to their counterparts with severe hearing loss. Conclusions—All listeners, but particularly the severe loss group, benefited from fast-acting WDRC amplification for low-level speech. For conversational and higher speech levels (i.e., when WDRC does not confer a significant audibility advantage), fast-acting WDRC amplification appears to slightly degrade performance. Listeners’ consonant confusion patterns suggest that this negative effect may be partly due to fast-acting WDRC-induced distortions which alter specific consonant features. In support of this view, audibility accounted for a greater percentage of the variance in listeners’ performance with CL amplification compared to fast-acting WDRC amplification

Differentiation state-specific mitochondrial dynamic regulatory networks are revealed by global transcriptional analysis of the developing chicken lens.

The mature eye lens contains a surface layer of epithelial cells called the lens epithelium that requires a functional mitochondrial population to maintain the homeostasis and transparency of the entire lens. The lens epithelium overlies a core of terminally differentiated fiber cells that must degrade their mitochondria to achieve lens transparency. These distinct mitochondrial populations make the lens a useful model system to identify those genes that regulate the balance between mitochondrial homeostasis and elimination. Here we used an RNA sequencing and bioinformatics approach to identify the transcript levels of all genes expressed by distinct regions of the lens epithelium and maturing fiber cells of the embryonic Gallus gallus (chicken) lens. Our analysis detected more than 15,000 unique transcripts expressed by the embryonic chicken lens. Of these, more than 3000 transcripts exhibited significant differences in expression between lens epithelial cells and fiber cells. Multiple transcripts coding for separate mitochondrial homeostatic and degradation mechanisms were identified to exhibit preferred patterns of expression in lens epithelial cells that require mitochondria relative to lens fiber cells that require mitochondrial elimination. These included differences in the expression levels of metabolic (DUT, PDK1, SNPH), autophagy (ATG3, ATG4B, BECN1, FYCO1, WIPI1), and mitophagy (BNIP3L/NIX, BNIP3, PARK2, p62/SQSTM1) transcripts between lens epithelial cells and lens fiber cells. These data provide a comprehensive window into all genes transcribed by the lens and those mitochondrial regulatory and degradation pathways that function to maintain mitochondrial populations in the lens epithelium and to eliminate mitochondria in maturing lens fiber cells

Ground Snow Loads for ASCE 7-22 – What Has Changed and Why?

The changes to the ASCE 7 ground snow load maps proposed for the 2022 edition target a uniform reliability rather than a uniform hazard – an important distinction – and are the first of their kind in ASCE 7. Previously, the ASCE 7 snow loads used a uniform-hazard 50-year mean recurrence interval (MRI) with a 1.6 load factor. The newly proposed loads directly target the safety levels stipulated in Chapter 1 of ASCE 7, resulting in a strength design level load that is to be used with a load factor of 1.0. This paper describes changes in design provisions that result from this transition to reliability-targeted loads and provides reasons for some of these differences