The Influence of Presbylarynx Status on Objective Measures of the Aging Voice.

OBJECTIVE: The primary objective of this study was to assess objective voice measures in an elderly population representative of those seen in a tertiary laryngology practice, stratified by sex and presbylarynx status, and compare their measures to each other and to a cohort of young adult patients aged 40 years or less. The secondary objectives of this study were to evaluate and compare the strobovideolaryngoscopy findings across all groups and compare the voice complaints and subjective questionnaire results between the presbylarynx and non-presbylarynx groups. METHODS: Two hundred and eighty-six adult voice patients (147 females/139 males) were included in this study and stratified into one of three groups: (1) young adults aged 40 years or less (n = 122), (2) patients over the age of 60 without presbylarynx (n = 78), and (3) patients over the age of 60 with a diagnosis of presbylarynx (n = 86). The acoustic analysis included fundamental frequency (F0), voice intensity, standard deviation of the fundamental frequency (SDFF), jitter (Jitt), relative average perturbation (RAP), shimmer (Shim), noise-to-harmonic ratio (NHR), and others. The aerodynamic and pulmonary assessment included maximum phonation time (MPT), S/Z ratio, mean flow rate (MFR), forced expiratory volume in 1 second (FEV1), and maximal mid-expiratory flow (FEF25-75). Coexisting vocal fold conditions and pathologies were also characterized and compared. Statistical analysis was performed using SPSS 28.0.0.0 (IBM, Armonk, NY). All tests were performed in two-tailed, and a P value of less than 0.05 was considered statistically significant. RESULTS: Assessment of vocal fold features revealed a significantly higher prevalence of benign vocal fold lesions in the young adult group for males and females compared to both elderly groups but significantly lower prevalence of vocal fold edema only in young adult females compared to the elderly female groups. Among males, young adults differed significantly from both elderly groups with regard to SDFF, Shim, FEV1, and FEF25-75. However, Jitt and RAP only differed significantly between the young adult and presbylarynx groups. Among females, young adults differed significantly from both elderly groups for F0, SDFF, Jitt, RAP, NHR, CPP, MFR, FEV1, and FEF25-75. However, the non-presbylarynx group had a significantly lower S/Z ratio than the young adult and presbylarynx groups. A comparison of voice complaints between elderly groups revealed breathiness to be significantly more common in the presbylarynx group compared to the non-presbylarynx group, but no other significant differences were found in voice complaints or questionnaire scores. CONCLUSION: When interpreting objective voice measures, it is critical to consider differences in vocal fold features alongside age-related changes. In addition, sex-related differences in anatomy and the aging process may explain discrepancies in significant findings between young adults and elderly patients stratified by presbylarynx status. However, presbylarynx status alone appears insufficient to generate significant differences in most objective voice measures among the elderly. Yet, presbylarynx status may be sufficient to generate differences in perceptual voice symptoms.

The impact of reducing the frequency of animals genotyped at higher density on imputation and prediction accuracies using ssGBLUP1.

The largest gains in accuracy in a genomic selection program come from genotyping young selection candidates who have not yet produced progeny and who might, or might not, have a phenotypic record recorded. To reduce genotyping costs and to allow for an increased amount of genomic data to be available in a population, young selection candidates may be genotyped with low-density (LD) panels and imputed to a higher density. However, to ensure that a reasonable imputation accuracy persists overtime, some parent animals originally genotyped at LD must be re-genotyped at a higher density. This study investigated the long-term impact of selectively re-genotyping parents with a medium-density (MD) SNP panel on the accuracy of imputation and on the genetic predictions using ssGBLUP in a simulated beef cattle population. Assuming a moderately heritable trait (0.25) and a population undergoing selection, the simulation generated sequence data for a founder population (100 male and 500 female individuals) and 9,000 neutral markers, considered as the MD panel. All selection candidates from generation 8 to 15 were genotyped with LD panels corresponding to a density of 0.5% (LD_0.5), 2% (LD_2), and 5% (LD_5) of the MD. Re-genotyping scenarios chose parents at random or based on EBV and ranged from 10% of male parents to re-genotyping all male and female parents with MD. Ranges in average imputation accuracy at generation 15 were 0.567 to 0.936, 0.795 to 0.985, and 0.931 to 0.995 for the LD_0.5, LD_2, and LD_5, respectively, and the average EBV accuracies ranged from 0.453 to 0.735, 0.631 to 0.784, and 0.748 to 0.807 for LD_0.5, LD_2, and LD_5, respectively. Re-genotyping parents based on their EBV resulted in higher imputation and EBV accuracies compared to selecting parents at random and these values increased with the size of LD panels. Differences between re-genotyping scenarios decreased when the density of the LD panel increased, suggesting fewer animals needed to be re-genotyped to achieve higher accuracies. In general, imputation and EBV accuracies were greater when more parents were re-genotyped, independent of the proportion of males and females. In practice, the relationship between the density of the LD panel used and the target panel must be considered to determine the number (proportion) of animals that would need to be re-genotyped to enable sufficient imputation accuracy.

Linkage disequilibrium in Brazilian Santa Inês breed, Ovis aries.

For genomic selection to be successful, there must be sufficient linkage disequilibrium between the markers and the causal mutations. The objectives of this study were to evaluate the extent of LD in ovine using the Santa Inês breed and to infer the minimum number of markers required to reach reasonable prediction accuracy. In total, 38,168 SNPs and 395 samples were used. The mean LD between adjacent marker pairs measured by r2 and |D'| were 0.166 and 0.617, respectively. LD values between adjacent marker pairs ranged from 0.135 to 0.194 and from 0.568 to 0.650 for r2 for |D'| across all chromosomes. The average r2 between all pairwise SNPs on each chromosome was 0.018. SNPs separated by between 0.10 to 0.20 Mb had an estimated average r2 equal to 0.1033. The identified haplotype blocks consisted of 2 to 21 markers. Moreover, estimates of average coefficients of inbreeding and effective population size were 0.04 and 96, respectively. LD estimated in this study was lower than that reported in other species and was characterized by short haplotype blocks. Our results suggest that the use of a higher density SNP panel is recommended for the implementation of genomic selection in the Santa Inês breed.