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In wearing contacts, a part of the wear debris is trapped between the surfaces, creating a wear debris bed. Many researchers report such beds providing a degree of protection against further wear. It was hypothesized, that in an annular contact, the level of debris entrapment increases with the width of the annulus resulting in decrease in wear. To test this hypothesis, two series of experiments using EN1A steel and 6082T6 aluminium alloy annuli, measuring 1, 2 and 4 mm wide were carried out. When steel was used, there was no clear correlation between ring width and total mass loss or steady-state wear rate. When aluminium was used, wear decreased with the ring width according to both metrics. This behaviour appears to correlate with worn surface roughness, suggesting worn surface roughness to be a parameter controlling debris entrapment. [ABSTRACT FROM AUTHOR]

Since pneumotachograph masks are commonly used in studies of speech breathing, the purpose of this study was to measure the differences in respiratory volumetric and frequency measures during speech under two conditions: with and without a circumferentially vented pneumotachograph mask coupled to the face. Thus we sought to identify whether changes in breathing patterns occur with the use of a specific face mask, because these patterns are accepted as representative of normal speech breathing. Subjects were 10 normal-speaking women, each of whom produced a syllable train and a connected speech task, both at comfortable intensity levels. Respiratory measures were made using linearized magnetometers during speech production. The measurements included lung volume, rib cage volume, and abdominal volume at utterance initiation and termination, volume excursions during the utterance, and the number of breath groups during the speech task. There were no significant differences between the mask-on and mask-off conditions in volumetric and frequency measures. A significant task difference for abdominal initiation was found. It was concluded that the use of a circumferentially vented pneumotachograph mask does not alter the reliability of respiratory volume and frequency measures for studies of voice. [ABSTRACT FROM AUTHOR]

Telehealth is increasing popular as a treatment option for people with Parkinson disease (PD). The SpeechVive device is a wearable device that uses the Lombard effect to help patients speak more loudly, slowly, and clearly. This study sought to examine the effectiveness of the device to improve communication in people with PD, delivered over a telehealth modality as compared to in-person, using implementation science design. 66 people with PD were enrolled for 12 weeks with 34 choosing the in-person group and 32 in the telehealth group. Participants were assessed pre-, mid-, and post-treatment. Participants produced continuous speech samples on and off the device at each timepoint. Sound pressure level (SPL), utterance length, pause frequency, and total pause duration were measured. Psychosocial surveys were administered to evaluate the effects of treatment on depression, self-efficacy, and participation. The in-person group increased SPL when wearing the device while the telehealth group did not. Both groups paused less often while wearing the device. Utterance length increased post-treatment for the telehealth group, but not for the in-person group. An increase in communication participation ratings in the telehealth group, but not the in-person group, was the only significant change in the psychosocial metrics. The in-person group showed similar treatment effects as previous studies. The device was not as effective in the telehealth group. One limitation was data loss due to recording issues that impacted the telehealth group more than the in-person group.

Background: When re-learning a motor skill, practicing a variety of treatment targets promotes error processing and the exploration of motor control strategies, which initially disrupts accuracy during training (motor performance), but ultimately enhances generalization, retention, and transfer (motor learning). Cough skill training (CST) is feasible and efficacious to improve cough strength; however, previous studies have used the same practice target during training., Objectives: Our goal was to examine the impact of CST with variable practice on motor performance, motor learning, and respiratory system adaptations., Method: The study was a prospective three-visit single group design. Twenty individuals with Parkinson's disease (PD) and concomitant dysphagia and dystussia completed two sessions of CST involving three randomized practice targets. Cough, lung volume, and airway clearance outcomes were assessed before and after treatment sessions with long-term retention evaluated after 1 month., Results: Peak expiratory flow rate improved after CST with variable practice for voluntary single (β = 0.35 L/s) and sequential (β = 0.22 L/s) cough, which were maintained after 1 month without treatment. The ability to expel material from the upper airway demonstrated a small magnitude of improvement (β = -1.87%). During CST, participants altered lung volume based on the treatment target and lung volume decreased during reflex cough after completing CST., Conclusions: Individuals with PD demonstrated improvements in several aspects of motor learning after two sessions of CST with variable practice. Increasing lung volume may not be an implicit strategy to upregulate voluntary cough strength in this treatment paradigm. The findings support the need for larger investigations exploring the potential benefits of this CST approach., (© 2024 International Parkinson and Movement Disorder Society.)

Objective: This study aims to identify sensitive respiratory, laryngeal, and self-perceptual measures for assessing vocal fatigue and to determine tasks that effectively elicit the experience of vocal fatigue., Methods: A scoping review was conducted using Cochrane, Medscape, PubMed, and Google Scholar databases. A total of 17 studies met the inclusion criteria and were reviewed in full and summarized. The studies were analyzed to extract relevant data on respiratory, laryngeal, and self-perceptual measures used to assess vocal fatigue, as well as the tasks employed to elicit vocal fatigue., Results: Of the 17 articles, 14 studies involved vocally healthy individuals, while three studies included participants with vocal fatigue. Phonation threshold pressure (PTP) was the most used and most consistent indirect respiratory measure in detecting vocal fatigue; however, only five studies included direct measurements of respiratory patterns and only two included ventilatory data. Laryngeal measures demonstrated inconsistent response to a vocal demand task, except mean fundamental frequency among vocally healthy participants, but not in those with complaints of vocal fatigue. Short-duration vowel tasks were found to be capable of eliciting vocal fatigue similar to prolonged reading tasks., Conclusion: Phonation threshold pressure (PTP) consistently captured vocal fatigue and can serve as an indirect respiratory measure. Measures of respiratory patterning and ventilation require further study. Fundamental frequency shows potential as a laryngeal measure of vocal fatigue in vocally healthy individuals but requires further investigation in those with vocal fatigue. Short-duration tasks elicit vocal fatigue and need to be investigated in future study protocols. These findings highlight the need to develop systematic protocols for ongoing assessment and monitoring of vocal fatigue to enhance both clinical practice and research methodologies., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships that may be considered as potential competing interests: Chaya Guntupalli Nanjundeswaran reports a relationship with National Institutes of Health that includes funding grants. Chaya Guntupalli Nanjundeswaran—editorial board member of Journal of Voice. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Inc.)

Purpose: Respiratory-swallow coordination (RSC) frequently changes in people with Parkinson's disease (PwPD). Little is known about how these changes relate to impairments in swallowing safety (penetration and aspiration) and efficiency (pharyngeal residue). Therefore, the aims of this study were to assess the relationships between RSC, pharyngeal residue, penetration, and aspiration in PwPD., Method: Twenty-four PwPD were recruited to undergo simultaneous assessment of RSC, swallowing safety, and swallowing efficiency. RSC was assessed using respiratory inductive plethysmography and nasal airflow and included measurements of respiratory pause duration, respiratory phase patterning, and lung volume during swallowing. Swallowing safety and efficiency were assessed using flexible endoscopic evaluation of swallowing, analyzed using the Visual Analysis of Swallowing Efficiency and Safety, and included measurements of pharyngeal residue, penetration, and aspiration. All data were blindly analyzed, with 20% of the data repeated for interrater reliability assessment. Multilevel statistical models were used to examine the relationships between RSC and swallowing., Results: A total of 812 swallows were analyzed from 24 participants. Only 33.4% of swallows exhibited the typical exhale-swallow-exhale pattern. Additionally, 95% of participants exhibited abnormal swallow function. More severe hypopharyngeal residue ratings were associated with inhaling before the swallow compared to exhaling before the swallow. Additionally, more severe events of penetration and aspiration were associated with (a) inhaling before the swallow compared to exhaling before the swallow, (b) inhaling after the swallow compared to exhaling after the swallow, and (c) longer swallow-related respiratory pause durations. Inhaling after the swallow exhibited the strongest relationship with impairments in swallowing safety when compared to all other RSC variables., Conclusions: RSC exhibited significant relationships with pharyngeal residue, penetration, and aspiration in these PwPD. Clinicians should attend to RSC when assessing swallowing in PwPD. Future research is needed to examine if training an exhale-swallow-exhale pattern can be used to improve disordered swallowing in PwPD., Open Science Form: https://doi.org/10.23641/asha.27211770.

Purpose: Sensorimotor cough skill training (CST) has been shown to improve cough strength, as well as facilitate changes during training (i.e., motor performance) and generalization to untrained tasks (i.e., motor learning). However, there is a gap in our understanding of the effects of voluntary CST (without sensory stimuli) on motor performance and learning. Furthermore, the contribution of physiologic factors, such as lung volume, a driver of cough strength in healthy adults, and treatment-specific factors, such as biofeedback, remains unexamined., Method: Twenty individuals with Parkinson's disease (PD) completed pre- and post-CST single voluntary, sequential voluntary, and reflex cough testing. Participants were randomized to biofeedback or no biofeedback groups. They completed one CST session involving 25 trials of voluntary coughs, with the treatment target set 25% above baseline peak flow. Participants were instructed to "cough hard" to exceed the target. In the biofeedback group, participants received direct visualization of the target line in real time., Results: Cough peak flow showed positive improvements in motor performance (β = .02; 95% credible interval [CI]: 0.01, 0.03) and learning (β = .26; 95% CI: 0.03, 0.47). Changes in lung volume from pre- to post-CST did not predict treatment response. No differences in treatment response were detected between the biofeedback groups., Conclusions: A single session of voluntary CST improved voluntary cough motor performance and learning. Although lung volume increased during CST, changes to lung volume did not predict treatment response. These findings demonstrate the potential of voluntary CST to improve motor performance and motor learning among individuals with PD and cough dysfunction., Supplemental Material and Open Science Form: https://doi.org/10.23641/asha.25447444.

Purpose: Cognitive impairment is one of the most debilitating nonmotor symptoms in Parkinson disease (PD), and its presentation is heterogeneous. One proposed model to explain cognitive variability in PD is the dual-syndrome hypothesis. This hypothesis delineates two cognitive profiles, a "fronto-striatal" profile and a "posterior cortical" profile according to symptom presentation, associated motor phenotype, and risk for dementia. The current study examined the dual-syndrome hypothesis in individuals with idiopathic PD to evaluate the existence of these profiles, determine the association with the motor phenotype (tremor dominant vs. postural instability/gait disorder), and assess the relative risk for dementia., Method: A retrospective examination was conducted using data from the Parkinson's Progression Markers Initiative database at baseline (within 2 years of diagnosis) and 5 years after baseline. Descriptive categorizations, cluster analyses, generalized linear mixed models, and logistic regressions were used to address the research questions., Results: There was emerging evidence of cognitive profiles; however, these were not fully supported by cluster analyses. Baseline cognitive profile was associated with later motor phenotype, and as predicted, dementia risk was greatest in persons with baseline posterior cortical impairments., Conclusion: The current results provide mixed support for the dual-syndrome hypothesis, with some evidence that the posterior cortical cognitive profile is associated with postural instability and gait disorder as well as greater dementia risk.

Purpose: This systematic review represents an update to previous reviews of the literature addressing behavioral management of respiratory/phonatory dysfunction in individuals with dysarthria due to neurodegenerative disease., Method: Multiple electronic database searches and hand searches of prominent speech-language pathology journals were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards., Results: The search yielded 1,525 articles, from which 88 met inclusion criteria and were reviewed by two blinded co-investigators. A large range of therapeutic approaches have been added to the evidence base since the last review, including expiratory muscle strength training, singing, and computer- and device-driven programs, as well as a variety of treatment modalities, including teletherapy. Evidence for treatment in several different population groups-including cerebellar ataxia, myotonic dystrophy, autosomal recessive spastic ataxia of Charlevoix-Saguenay, Huntington's disease, multiple system atrophy, and Lewy body dementia-were added to the current review. Synthesis of evidence quality provided strong evidence in support of only one behavioral intervention: Lee Silverman Voice Treatment Program (LSVT LOUD) in people with Parkinson's disease. No other treatment approach or population included in this review demonstrated more than limited evidence, reflecting that these approaches/populations require urgent further examination., Conclusion: Suggestions about where future research efforts could be significantly strengthened and how clinicians can apply research findings to their practice are provided., Supplemental Material: https://doi.org/10.23641/asha.24964473.

The goal of this study was to explore telehealth use for dysphagia management in response to COVID-19 to understand variables associated with clinician confidence and perceived effectiveness of this service delivery model and determine clinician-perceived benefits and challenges of managing dysphagia via telehealth. Speech-language pathologists (SLPs, n = 235) completed a web-based survey, providing information on demographics, telehealth use during the pandemic, and perspectives on current and future tele-management of dysphagia. Analyses included descriptive statistics to examine usage patterns; logistic regression to determine which variables were associated with telehealth use, clinician confidence, and perceived-effectiveness; and conventional content analysis to analyze responses to open-ended questions. Results revealed a sharp increase in the tele-management of dysphagia during the pandemic. Years of experience with dysphagia management (p = .031) and pre-pandemic use of telehealth (p < .001) were significantly associated with current use patterns. Working in the outpatient setting was associated with greater clinician confidence (p = .003) and perceived effectiveness (p = .007), and use of guidelines (p = .042) was also associated with greater clinician confidence. Key challenges identified included inadequate technological infrastructure, inadequate patient digital literacy, and reimbursement restrictions. Key benefits were treatment continuity, improving access to care, and time savings. The majority (67%) of respondents reported that they would use telehealth in the future. These findings demonstrate SLPs' abilities and desire to expand their practice patterns to include telehealth for dysphagia management. Therefore, clinician training and more research on best practices for assessment and treatment of dysphagia via telehealth is warranted to refine models of care for dysphagia tele-management., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: Hypokinetic dysarthria associated with Parkinson's disease (PD) is characterized by dysprosody, yet the literature is mixed with respect to how dysprosody affects the ability to mark lexical stress, possibly due to differences in speech tasks used to assess lexical stress. The purpose of this study was to compare how people with and without PD modulate acoustic dimensions of lexical stress-fundamental frequency, intensity, and duration-to mark lexical stress across three different speech tasks., Method: Twelve individuals with mild-to-moderate idiopathic PD and 12 age- and sex-matched older adult controls completed three speech tasks: picture description, word production in isolation, and word production in lists. Outcome measures were the fundamental frequency, intensity, and duration of the vocalic segments of two trochees (initial stress) and two iambs (final stress) spoken in all three tasks., Results: There were very few group differences. Both groups marked trochees by modulating intensity and fundamental frequency and iambs by modulating duration. Task had a significant impact on the stress patterns used by both groups. Stress patterns were most differentiated in words produced in isolation and least differentiated in lists of words., Conclusions: People with PD did not demonstrate impairments in the production of lexical stress, suggesting that dysprosody associated with PD does not impact all types of prosody in the same way. However, there were reduced distinctions in stress marking that were more apparent in trochees than iambs. In addition, the task used to assess prosody has a significant effect on all acoustic measures. Future research should focus on the use of connected speech tasks to obtain more generalizable measures of prosody in PD.

Purpose: The purpose of this study was to examine the respiratory strategies used by persons with Parkinson's disease (PD) to support louder speech in response to two voice interventions. Contrasting interventions were selected to investigate the role of internal and external cue strategies on treatment outcomes. LSVT LOUD, which uses an internal cueing framework, and the SpeechVive prosthesis, which employs an external noise cue to elicit louder speech, were studied., Method: Thirty-four persons with hypophonia secondary to idiopathic PD were assigned to one of three groups: LSVT LOUD ( n = 12), SpeechVive ( n = 12), or a nontreatment clinical control ( n = 10). The LSVT LOUD and SpeechVive participants received 8 weeks of voice intervention. Acoustic and respiratory kinematic data were simultaneously collected at pre-, mid- and posttreatment during a monologue speech sample. Intervention outcomes included sound pressure level (SPL), utterance length, lung volume initiation, lung volume termination, and lung volume excursion., Results: As compared to controls, the LSVT LOUD and SpeechVive participants significantly increased SPL at mid- and posttreatment, thus confirming a positive intervention effect. Treatment-related changes in speech breathing were further identified, including significantly longer utterance lengths (syllables per breath group) at mid- and posttreatment, as compared to pretreatment. The respiratory strategies used to support louder speech varied by group. The LSVT LOUD participants terminated lung volume at significantly lower levels at mid- and posttreatment, as compared to pretreatment. This finding suggests the use of greater expiratory muscle effort by the LSVT LOUD participants to support louder speech. Participants in the SpeechVive group did not significantly alter their respiratory strategies across the intervention period. Single-subject effect sizes highlight the variability in respiratory strategies used across speakers to support louder speech., Conclusions: This study provides emerging evidence to suggest that the LSVT LOUD and SpeechVive therapies elicit different respiratory adjustments in persons with PD. The study highlights the need to consider respiratory function when addressing voice targets in persons with PD.

Purpose: The purpose of the study was to examine the effect of two voice intervention approaches for hypophonia secondary to Parkinson's disease (PD) on self-reported measures of physical demand, mental demand, and vocal performance., Method: Thirty-four persons with hypophonia secondary to PD were assigned to one of three groups: Lee Silverman Voice Treatment (LSVT) LOUD ( n = 12), SpeechVive ( n = 12), and nontreatment clinical control ( n = 10). The LSVT LOUD and the SpeechVive participants received 8 weeks of voice intervention following the standardized protocol previously described for each approach. To confirm the effectiveness of each voice intervention, sound pressure level (dB SPL) data were analyzed for the experimental and control participants for a monologue sample obtained pretreatment, midtreatment, and posttreatment. During the voice intervention period, the LSVT LOUD and the SpeechVive participants were instructed to complete a modified version of the National Aeronautics and Space Administration Task Load Index rating scale to indicate the mental and physical demand required to complete the intervention activities, and to indicate how well they performed in completing the assigned vocal tasks., Results: The LSVT LOUD and the SpeechVive participants demonstrated a significant posttreatment increase in SPL (dB), in comparison to the clinical controls, thus confirming a positive intervention effect. The LSVT LOUD participants reported significantly higher ratings of physical and mental demand over the course of treatment, in comparison to the SpeechVive participants., Conclusion: Consideration of the mental and physical demand associated with two voice intervention approaches, commonly used for PD, may help to foster improved therapeutic compliance and treatment outcomes.

Purpose: Vocal exertion is common and often results in reduced respiratory and laryngeal efficiency. It is unknown, however, whether the respiratory kinematic and acoustic adjustments employed during vocal exertion differ between speakers reporting vocal fatigue and those who do not. This study compared respiratory kinematics and acoustic measures in individuals reporting low and high levels of vocal fatigue during a vocal exertion task., Methods: Individuals reporting low (N = 20) and high (N = 10) vocal fatigue participated in a repeated measures design study over 2 days. On each day, participants completed a 10-minute vocal exertion task consisting of repeated, loud vowel productions at elevated F0 sustained for maximum phonation time. Respiratory kinematic and acoustic measures were analyzed on the 1st vowel production (T0), and the vowels produced 2 minutes (T2), 5 minutes (T5), 7 minutes (T7), and 10 minutes (T10) into the vocal exertion task. Vowel durations were also measured at each time point., Results: No differences in respiratory kinematics were observed between low and high vocal fatigue groups at T0. As the vocal exertion task progressed (T2-T10), individuals reporting high vocal fatigue initiated phonation at lower lung volumes while individuals with low vocal fatigue initiated phonation at higher lung volumes. As the exertion task progressed, total lung volume excursion decreased in both groups. Differences in acoustic measures were observed, as individuals reporting high vocal fatigue produced softer, shorter vowels from T0 through T10., Conclusions: Individuals reporting high vocal fatigue employed less efficient respiratory strategies during periods of increased vocal demand when compared with individuals reporting low vocal fatigue. Individuals reporting high vocal fatigue had shorter maximum phonation time on loud vowels. Further study should examine the potential screening value of loud maximum phonation time, as well as the clinical implications of the observed respiratory patterns for managing vocal fatigue., Competing Interests: The authors have declared that no competing interests exist.

Purpose: A critical component to the development of any type of intervention to improve speech production in individuals with Parkinson's disease (PD) is a complete understanding of the speech impairments present at each stage of the disease and how these impairments change with disease progression. The purpose of this longitudinal study was to examine the impact of disease on speech production and speech breathing during an extemporaneous speech task in individuals with PD over the course of approximately 3.5 years., Method: Eight individuals with PD and eight age- and sex-matched control participants produced an extemporaneous connected speech task on two occasions (Time 1 and Time 2) an average of 3 years 7 months apart. Dependent variables included sound pressure level; utterance length; speech rate; lung volume initiation, termination, and excursion; and percent vital capacity per syllable., Results: From Time 1 to Time 2, individuals with PD demonstrated decreased utterance length and lung volume initiation, termination, and excursion and increased speech rate. Control participants demonstrated decreased utterance length and lung volume termination and increased lung volume excursion and percent vital capacity per syllable from Time 1 to Time 2., Conclusions: Changes in speech production and speech breathing variables experienced by individuals with PD over the course of several years are related to their disease process and not typical aging. Changes to speech breathing highlight the need to provide intervention focused on increasing efficient respiratory patterning for speech production.

Purpose: The aim of this study was to examine the effects of bolus holding on respiratory-swallow coordination (RSC) in people with Parkinson's disease (PD)., Method: People with PD were prospectively recruited to undergo RSC assessment using simultaneous respiratory inductive plethysmography and flexible laryngoscopy. During RSC assessment, participants swallowed 5-ml thin liquid boluses during held and nonheld swallowing tasks. Measures of RSC were analyzed for each swallow, which included respiratory pause duration, lung volume at swallow initiation, respiratory phase patterning, and the presence of paradoxical respiratory movements. Multilevel statistical modeling was used to determine if differences in RSC were present between the held and nonheld tasks., Results: Thirty-three participants were enrolled. When compared to the nonheld swallows, the held swallows exhibited shorter respiratory pauses ( p = .001, R 2 = .019), lower lung volumes at swallow initiation ( p < .001, R 2 = .116), more frequent exhale-swallow-exhale patterns ( p < .001, OR = 4.30), and less frequent paradoxical respiratory movements ( p = .001, OR = 0.43)., Conclusions: Findings from this study revealed that bolus holding significantly influences RSC in people with PD. This demonstrates that bolus holding may be an efficacious strategy to immediately improve RSC in PD. However, clinicians and researchers should consider avoiding bolus holding during swallowing evaluations if attempting to assess RSC behaviors that are most typical for the examinee.

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers., (© 2021 Wiley-VCH GmbH.)

Objectives/hypothesis: To investigate the effects of acute vocal exertion on individuals with vocal fatigue and to determine whether semi-occluded vocal tract exercises (SOVTEs) are more effective than vocal rest in mitigating acute effects., Study Design: Prospective, repeated-measures design., Methods: On consecutive days, 10 individuals (6 males, 4 females) with scores indicating vocal fatigue on the Vocal Fatigue Index completed two 10-minute vocal exertion tasks. Vocal rest or SOVTEs were interspersed in counterbalanced order between exertion tasks. Respiratory kinematic, acoustic, aerodynamic, and self-perceptual measures were collected at baseline, following vocal exertion, following SOVTE/vocal rest, and following the second exertion task., Results: Acute vocal exertion worsened phonation threshold pressure (P < .001) and vocal effort (P < .001) and reduced maximum fundamental frequency (P < .001). Speech was terminated at lower lung volumes following vocal exertion (decreased lung volume termination [LVT], P < .001). Exertion-induced changes in vocal effort and LVT were significantly reversed by both vocal rest and SOVTE. Detrimental changes in voice measures reoccurred following the second vocal exertion task. SOVTE and vocal rest protected against changes in respiratory kinematics when vocal exertion was resumed., Conclusions: Vocal exertion impacted laryngeal, respiratory, and self-perceptual measures in individuals with vocal fatigue. Both SOVTE and vocal rest partially mitigated changes in voice measures and prompted more efficient respiratory strategies that were maintained when vocal exertion resumed. These data increase our understanding of how individuals with vocal fatigue respond to vocal exertion tasks and offer preliminary guidance for optimal clinical recommendations., Level of Evidence: 3 Laryngoscope, 131:2732-2739, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Disease manifestations in COVID-19 range from mild to severe illness associated with a dysregulated innate immune response. Alterations in function and regeneration of dendritic cells (DCs) and monocytes may contribute to immunopathology and influence adaptive immune responses in COVID-19 patients. We analyzed circulating DC and monocyte subsets in 65 hospitalized COVID-19 patients with mild/moderate or severe disease from acute illness to recovery and in healthy controls. Persisting reduction of all DC subpopulations was accompanied by an expansion of proliferating Lineage-HLADR+ cells lacking DC markers. Increased frequency of CD163+ CD14+ cells within the recently discovered DC3 subpopulation in patients with more severe disease was associated with systemic inflammation, activated T follicular helper cells, and antibody-secreting cells. Persistent downregulation of CD86 and upregulation of programmed death-ligand 1 (PD-L1) in conventional DCs (cDC2 and DC3) and classical monocytes associated with a reduced capacity to stimulate naïve CD4+ T cells correlated with disease severity. Long-lasting depletion and functional impairment of DCs and monocytes may have consequences for susceptibility to secondary infections and therapy of COVID-19 patients., Competing Interests: The authors have declared that no competing interests exist.

Purpose This study aims to investigate the effects of a 10-min vocal exertion task on voice and respiratory measures, to determine whether restorative strategies can mitigate these effects after cessation of exertion, and to assess whether these strategies continue to reduce these detrimental effects when vocal exertion is resumed. Method A prospective, repeated-measures design was used. On consecutive days, 20 participants (equal men and women) completed two vocal exertion tasks separated by 10 min of restoration strategies: vocal rest or controlled phonation (low-level tissue mobilization using straw phonation). Voice and respiratory data were collected at baseline, following the first exertion task, after restoration strategies, and after the second exertion task. Outcome measures included (a) vocal effort, (b) phonation threshold pressure, (c) maximum and minimum fundamental frequencies, (d) cepstral peak prominence of connected speech, (e) lung volume initiation and termination, (f) percent vital capacity expended per syllable, and (g) number of syllables per breath group. Results A worsening of phonation threshold pressure ( p < .001), vocal effort ( p < .001), and increase of minimum fundamental frequency ( p = .007) were observed after vocal exertion. Lung volume initiation ( p < .001) and lung volume termination ( p < .001) increased. These changes were largely reversed by restoration strategies, but only controlled phonation prevented exertion-induced changes in respiratory kinematic measures on a subsequent vocal exertion task. Conclusions Exertion-induced voice changes occur rapidly and may be mitigated by either controlled phonation or vocal rest. Controlled phonation is recommended as a superior strategy due to evidence of a protective effect on a successive vocal exertion task.

Purpose COVID-19 has shifted models of health care delivery, requiring the rapid adoption of telehealth, despite limited evidence and few resources to guide speech-language pathologists. Management of dysarthria presents specific challenges in the telehealth modality. Evaluations of dysarthria typically rely heavily on perceptual judgments, which are difficult to obtain via telehealth given a variety of technological factors such as inconsistencies in mouth-to-microphone distance, changes to acoustic properties based on device settings, and possible interruptions in connection that may cause video freezing. These factors limit the validity, reliability, and clinicians' certainty of perceptual speech ratings via telehealth. Thus, objective measures to supplement the assessment of dysarthria are essential. Method This tutorial outlines how to obtain objective measures in real time and from recordings of motor speech evaluations to support traditional perceptual ratings in telehealth evaluations of dysarthria. Objective measures include pause patterns, utterance length, speech rate, diadochokinetic rates, and overall speech severity. We demonstrate, through clinical case vignettes, how these measures were completed following three clinical telehealth evaluations of dysarthria conducted via Zoom during the COVID-19 pandemic. This tutorial describes how each of these objective measures were utilized, in combination with subjective perceptual analysis, to determine deviant speech characteristics and their etiology, develop a patient-specific treatment plan, and track change over time. Conclusion Utilizing objective measures as an adjunct to perceptual ratings for telehealth dysarthria evaluations is feasible under real-world pandemic conditions and can be used to enhance the quality and utility of these evaluations.

Purpose The purposes of this longitudinal study were to (a) examine the impact of Parkinson's disease (PD) progression on breath pause patterns and speech and linguistic errors and (b) determine the extent to which breath pauses and speech and linguistic errors contribute to speech impairment. Method Eight individuals with PD and eight age- and sex-matched control participants produced a reading passage on two occasions (Time 1 and Time 2) 3 years and 7 months apart on average. Two speech-language pathologists rated the severity of speech impairment for all participants at each time. Dependent variables included the location of each breath pause relative to syntax and punctuation as well as the number of disfluencies and mazes. Results At Time 1, there were no significant differences between the groups regarding breath pause patterns. At Time 2, individuals with PD produced significantly fewer breath pauses at major syntactic boundaries and periods as well as significantly more breath pauses at locations with no punctuation than control participants. Individuals with PD produced a significantly greater number of disfluencies than control participants at both time points. There were no significant differences between the groups in the number of mazes produced at either time point. Together, the number of mazes and the percentage of breath pauses at locations with no punctuation explained 50% of the variance associated with the ratings of severity of speech impairment. Conclusion These results highlight the importance of targeting both respiratory physiological and cognitive-linguistic systems in order to improve speech production in individuals with PD.

This paper presents an investigation into high temperature imaging of metals through the use of a novel heat stage for in situ Scanning Electron Microscopy (SEM). The results obtained demonstrate the benefits and challenges of SEM imaging at elevated temperatures of up to 850 °C using Secondary Electron (SE) and Electron Backscatter Diffraction (EBSD) detectors. The data collected using the heat stage demonstrate good beam, vacuum, and detector stability at high temperatures without the need for shielding or detector modification owing to the heat stage geometry. SE imaging highlighted one possible application: carrying out thermal etching, a process in which surface grooves form along a material's grain boundaries during heating in situ. The data suggest that using the heat stage to perform imaging during the process gives a more accurate representation of a material's microstructure at temperature than examining the thermally etched specimen after cooling. This study also highlights some of the challenges of high temperature in situ EBSD imaging in both steel and nickel at a variety of temperatures and time scales. In particular, the data demonstrate the effect of surface roughness on EBSD imaging and how microstructural changes during heating may affect this. Additionally, the ease with which a material can be imaged using EBSD at temperature may be affected by the material's magnetic properties. For the first time, it is shown that at temperatures close to the Curie temperature of ferromagnetic materials, in this case Nickel, there is a loss of EBSD image quality. Quality was regained when temperatures were further increased. Despite these challenges, good quality EBSD scans were produced, further highlighting the benefits of in situ testing for providing information on grain boundaries, orientations, and phase change at elevated temperatures.

Objectives: T follicular helper (Tfh) cells are the principal T helper cell subset that provides help to B cells for potent antibody responses against various pathogens. In this study, we took advantage of the live-attenuated yellow fever virus (YFV) vaccine strain, YF-17D, as a model system for studying human antiviral immune responses in vivo following exposure to an acute primary virus challenge under safe and highly controlled conditions, to comprehensively analyse the dynamics of circulating Tfh (cTfh) cells., Methods: We tracked and analysed the response of cTfh and other T and B cell subsets in peripheral blood of healthy volunteers by flow cytometry over the course of 4 weeks after YF-17D vaccination., Results: Using surface staining of cell activation markers to track YFV-specific T cells, we found increasing cTfh cell frequencies starting at day 3 and peaking around 2 weeks after YF-17D vaccination. This kinetic was confirmed in a subgroup of donors using MHC multimer staining for four known MHC class II epitopes of YF-17D. The subset composition of cTfh cells changed dynamically during the course of the immune response and was dominated by the cTfh1-polarised subpopulation. Importantly, frequencies of cTfh1 cells correlated with the strength of the neutralising antibody response, whereas frequencies of cTfh17 cells were inversely correlated., Conclusion: In summary, we describe detailed cTfh kinetics during YF-17D vaccination. Our results suggest that cTfh expansion and polarisation can serve as a prognostic marker for vaccine success. These insights may be leveraged in the future to improve current vaccine design and strategies., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Clinical & Translational Immunology published by John Wiley & Sons Australia, Ltd on behalf of Australian and New Zealand Society for Immunology, Inc.)

Background: Human immunology research is often limited to peripheral blood. However, there are important differences between blood immune cells and their counterparts residing in secondary lymphoid organs, such as in the case of germinal center (GC) T follicular helper (Tfh) cells and GC B cells., Methods: We developed a versatile ex vivo lymphoid organ culture platform that is based on human pharyngeal tonsils (adenoids) and allows for drug testing. We systematically phenotyped Tfh and GC B cell subsets in explant- and suspension cultures using multicolor flow cytometry and cytokine multiplex analysis., Findings: Phenotypic changes of certain ex vivo cultured immune cell subsets could be modulated by cytokine addition. Furthermore, we optimized an activation-induced marker assay to evaluate the response to T cell stimulation. We provide proof-of-concept that Tfh and GC B cells could be modulated in these cultures by different anti-inflammatory drugs in unstimulated states and upon activation with vaccine-derived antigens. For example, GC B cells were lost upon CD40L blockade, and clinically approved JAK inhibitors impacted Tfh and GC B cells, including down-regulation of their key transcription factor BCL6. BCL6 regulation was affected by IL-6 signaling in T cells and IL-4 in B cells, respectively. Furthermore, we demonstrated that JAK signaling and TNF signaling contributed to the stimulation-induced activation of tonsil-derived T cells., Interpretation: Our optimized methods, assays, and mechanistic findings can contribute to a better understanding of human GC responses. These insights may be relevant for improving autoimmune disease therapy and vaccination efficacy., Funding: This work was supported by a project grant under the joint research cooperation agreement of LMU Munich, LMU University Hospital, and Sanofi-Aventis Deutschland GmbH, as well as by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Emmy Noether Programme BA 5132/1-1 and BA 5132/1-2 (252623821), SFB 1054 Project B12 (210592381), and SFB 914 Project B03 (165054336)., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Fingolimod is an effective treatment for relapsing-remitting multiple sclerosis. It is well established that fingolimod, a modulator of the sphingosine-1-phosphate pathway, restrains the egress of CCR7 + lymphocytes from lymphatic tissues into the blood, thus resulting in reduced lymphocyte counts in peripheral blood. CXCR5 + T follicular helper (Tfh) cells provide help to B cells, are essential for the generation of potent Ab responses, and have been shown to be critically involved in the pathogenesis of several autoimmune diseases. Besides lymphoid tissue-resident Tfh cells, CXCR5 + circulating Tfh (cTfh) cells have been described in the blood, their numbers correlating with the magnitude of Tfh cells in lymphoid tissues. Although the effect of fingolimod on circulating lymphocyte subsets has been established, its effect on cTfh cells remains poorly understood. In this study, we found that although fingolimod strongly and disproportionally reduced cTfh cell frequencies, frequencies of activated cTfh cells were increased, and the composition of the cTfh cell pool was skewed toward a cTfh1 cell phenotype. The circulating T follicular regulatory cell subset and CXCR5 + CD8 + T cell frequencies were also strongly and disproportionally decreased after fingolimod treatment. In contrast, relative frequencies of CXCR5 - memory Th cells as well as regulatory T and B cells were increased. In summary, these data provide new insights into fingolimod-induced compositional changes of lymphocyte populations in the blood, in particular cTfh cells, and thus contribute to a better understanding of the mechanism of action of fingolimod in multiple sclerosis patients., (Copyright © 2020 by The American Association of Immunologists, Inc.)

These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Purpose This study evaluated the accuracy of respiratory calibration methods for estimating lung volume during speech breathing. Method Respiratory kinematic data were acquired via inductance plethysmography in 32 young adults, 22 older adults, and 13 older adults with Parkinson's disease (PD). Raw rib cage (RC) and abdomen (AB) signals (V) were calibrated to liters using 4 correction methods: (a) isovolume maneuvers, (b) a constant 2:1 RC-to-AB ratio, (c) least squares method with RC correction only (LsqRC), and (d) least squares method with both RC and AB corrections (LsqRC/AB). Mean percent error, the absolute difference between estimated and actual lung volumes then normalized to each speaker's vital capacity, was calculated for each method. Results For young adults, the LsqRC/AB method significantly reduced mean percent error compared to all other methods. Although LsqRC/AB also resulted in smaller errors for older adults and adults with PD, LsqRC/AB and LsqRC were not significantly different from one another in these groups. Conclusion The LsqRC/AB method reduces errors across all cohorts, but older adults and adults with PD also have reduced errors when using LsqRC. Further research should investigate both least squares methods across larger age and disease severity ranges.

Purpose In Parkinson's disease (PD), there are significant changes in the basal ganglia, a structure known to be important for controlling automatic responses to cues. Changes to the basal ganglia in PD impair an individual's ability to trigger a behavior in response to cues, but more so in response to internal cues more than external ones. Filled pauses are considered a subconscious or automatic speech response to an internal cue that there are difficulties with ongoing communication. Typical speakers use filled pauses (such as uh or um) to mark silent pauses. The purpose of this study was to examine how automatic speech responses are impacted in PD by looking at filled and silent pausing behaviors, extending our understanding of the role of the basal ganglia in automatic behaviors. We hypothesized that individuals with PD would use fewer filled pauses and longer silent pauses. We also hypothesized that longer pauses would be more likely to be marked with filled pauses and that this relationship would be weaker in speakers with PD. Method Speech samples were collected via a story-retelling task from 15 individuals with PD and 18 age-matched controls. Duration and frequency of filled and silent pauses were measured using spectrographic analysis. Number and duration of marked silent pauses (those consecutive with 1 or more filled pauses) were measured. The t tests and analyses of variance were used to test our hypotheses. Results There was no significant difference in the number of silent pauses between groups, but the duration of silent pauses was significantly greater for individuals with PD. Despite this, individuals with PD produced significantly fewer filled pauses and fewer marked silent pauses. For both groups, longer silent pauses were more likely to be marked by filled pauses, but individuals with PD marked a smaller percentage of silent pauses at longer durations than controls. Conclusions Producing fewer marked silent pauses, coupled with longer silent pauses, reduces natural cues to discourse and puts people with PD at greater risk of sounding unnatural and losing their communicative turn. These results suggest that automatic responses regarding speech production difficulties are impaired by PD. This interpretation fits with nonspeech literature where automatic responses have been demonstrated to be impaired in PD.

Purpose: The purpose of this study was to examine laryngeal and respiratory physiological changes in teachers before and after a 1-hour vocal loading challenge., Methods: Twelve teachers completed ratings of vocal tiredness, vocal effort, and produced a reading passage and monologue before and after a 1-hour vocal loading challenge (reading aloud in noise). Sound pressure level, lung volume parameters, cepstral peak prominence, and low/high spectral ratio were measured., Results: After loading, participants significantly increased vocal effort, vocal tiredness, utterance length, and sound pressure level, and significantly decreased % vital capacity/syllable., Conclusions: Following the 1-hour reading-aloud challenge, tiredness and effort increased. However, lung volume did not change and cepstral peak prominence and low/high spectral ratio remained in the normal range. Future studies are needed to understand the effect of vocal use and vocal loading in teachers., (Copyright © 2019 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Individuals are often required to complete two tasks simultaneously, such as walking while talking. Although the influence of performing a cognitive task during upright standing has been studied, less is known regarding how individuals prioritize the performance of multiple goal-directed tasks. The purpose of this study was to examine how young adults prioritize the performance of two goal-directed tasks while standing: generating speech (communicating) while performing a postural-manual task. Fifteen young adult female participants completed four conditions of the postural-manual task, quietly and while talking; a control condition of speech while standing was also completed. Task accuracy was defined as holding a block within an opening without hitting the perimeter and speaking clearly. Participants generally prioritized accurate communication over accurate completion of the postural-manual task, as evidenced by modifying their manual and postural strategies and decreasing manual accuracy.

Background: Walking while talking is an ideal multitask behavior to assess how young healthy adults manage concurrent tasks as it is well-practiced, cognitively demanding, and has real consequences for impaired performance in either task. Since the association between cognitive tasks and gait appears stronger when the gait task is more challenging, gait challenge was systematically manipulated in this study., Objective: To understand how young adults accomplish the multitask behavior of walking while talking as the gait challenge was systematically manipulated., Methods: Sixteen young adults (21 ± 1.6 years, 9 males) performed three gait tasks with and without speech: unobstructed gait (easy), obstacle crossing (moderate), obstacle crossing and tray carrying (difficult). Participants also provided a speech sample while seated for a baseline indicator of speech. The speech task was to speak extemporaneously about a topic (e.g. first car). Gait speed and the duration of silent pauses during speaking were determined. Silent pauses reflect cognitive processes involved in speech production and language planning., Results: When speaking and walking without obstacles, gait speed decreased (relative to walking without speaking) but silent pause duration did not change (relative to seated speech). These changes are consistent with the idea that, in the easy gait task, participants placed greater value on speech pauses than on gait speed, likely due to the negative social consequences of impaired speech. In the moderate and difficult gait tasks both parameters changed: gait speed decreased and silent pauses increased., Conclusion: Walking while talking is a cognitively demanding task for healthy young adults, despite being a well-practiced habitual activity. These findings are consistent with the integrated model of task prioritization from Yogev-Seligmann et al., [1]., (Copyright © 2018 Elsevier B.V. All rights reserved.)

While growing evidence reports changes in language use in non-demented individuals with Parkinson's disease (PD), the presence and nature of the deficits remain largely unclear. Researchers have proposed that dysfunctioning fronto-basal ganglia circuit results in impaired grammatical processes, predicting qualitatively similar language impairments between individuals with PD and agrammatic Broca's aphasia, whereas others suggest that PD is not associated with language-specific grammatical impairment. In addition, there is a paucity of research examining syntactic production in PD at the sentence-level. This study examined sentence production of individuals with PD, healthy older adults, and individuals with agrammatic Broca's aphasia. In Experiment 1, using a Cinderella story-telling task, proportion of grammatical sentences, number of embedded clauses and production of verb arguments in sentences were examined. In Experiment 2, a structured sentence elicitation task was used in which syntactic complexity of sentences (canonical vs. non-canonical word order) was systematically manipulated while minimizing demands for non-syntactic processing. Only the participants with agrammatic Broca's aphasia showed significantly impaired syntactic production in both experiments. Participants with PD did not show impaired syntactic production in either task, despite impairments in lexical retrieval, repetition of words and sentences, and speech production. These findings suggest that impaired syntactic processing may not be a core deficit underlying the changes in language use in non-demented PD. Changes in language use in PD are qualitatively different from language deficits in aphasia.