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1.  Quantitative Measurement of Vocal Fold Vibration in Male Radio Performers and Healthy Controls Using High-Speed Videoendoscopy 
PLoS ONE  2014;9(6):e101128.
Acoustic and perceptual studies show a number of differences between the voices of radio performers and controls. Despite this, the vocal fold kinematics underlying these differences are largely unknown. Using high-speed videoendoscopy, this study sought to determine whether the vocal vibration features of radio performers differed from those of non-performing controls.
Using high-speed videoendoscopy, recordings of a mid-phonatory/i/ in 16 male radio performers (aged 25–52 years) and 16 age-matched controls (aged 25–52 years) were collected. Videos were extracted and analysed semi-automatically using High-Speed Video Program, obtaining measures of fundamental frequency (f0), open quotient and speed quotient. Post-hoc analyses of sound pressure level (SPL) were also performed (n = 19). Pearson's correlations were calculated between SPL and both speed and open quotients.
Male radio performers had a significantly higher speed quotient than their matched controls (t = 3.308, p = 0.005). No significant differences were found for f0 or open quotient. No significant correlation was found between either open or speed quotient with SPL.
A higher speed quotient in male radio performers suggests that their vocal fold vibration was characterised by a higher ratio of glottal opening to closing times than controls. This result may explain findings of better voice quality, higher equivalent sound level and greater spectral tilt seen in previous research. Open quotient was not significantly different between groups, indicating that the durations of complete vocal fold closure were not different between the radio performers and controls. Further validation of these results is required to determine the aetiology of the higher speed quotient result and its implications for voice training and clinical management in performers.
PMCID: PMC4074127  PMID: 24971625
2.  The Mycovirus CHV1 Disrupts Secretion of a Developmentally Regulated Protein in Cryphonectria parasitica 
Journal of Virology  2012;86(11):6067-6074.
Infection of the chestnut blight fungus Cryphonectria parasitica with Cryphonectria hypovirus 1 (CHV1) causes disruption of virulence, pigmentation, and sporulation. Transcriptional downregulation of key developmentally regulated fungal genes occurs during infection, but vegetative growth is unaffected. Previous studies showed that CHV1 utilizes trans-Golgi network (TGN) secretory vesicles for replication. In this study, the fungal cell surface hydrophobin cryparin was chosen as a marker to follow secretion in virally infected and noninfected strains. Subcellular fractionation, cryparin-green fluorescent protein (GFP) fusion, and Western blot studies confirmed that vesicles containing cryparin copurify with the same fractions previously shown to contain elements of the viral replication complex and the TGN resident endoprotease Kex2. This vesicle fraction accumulated to a much greater concentration in the CHV1-infected strains than in noninfected strains. Pulse-chase analysis showed that the rates and amount of cryparin being secreted by the CHV1 containing strains was much lower than in noninfected strains, and the dwell time of cryparin within the cell after labeling was significantly greater in the CHV1-infected strains than in the noninfected ones. These results suggest that the virus perturbs a specific late TGN secretory pathway resulting in buildup of a key protein important for fungal development.
PMCID: PMC3372201  PMID: 22438560
3.  A comparison of two treatments for childhood apraxia of speech: methods and treatment protocol for a parallel group randomised control trial 
BMC Pediatrics  2012;12:112.
Childhood Apraxia of Speech is an impairment of speech motor planning that manifests as difficulty producing the sounds (articulation) and melody (prosody) of speech. These difficulties may persist through life and are detrimental to academic, social, and vocational development. A number of published single subject and case series studies of speech treatments are available. There are currently no randomised control trials or other well designed group trials available to guide clinical practice.
A parallel group, fixed size randomised control trial will be conducted in Sydney, Australia to determine the efficacy of two treatments for Childhood Apraxia of Speech: 1) Rapid Syllable Transition Treatment and the 2) Nuffield Dyspraxia Programme – Third edition. Eligible children will be English speaking, aged 4–12 years with a diagnosis of suspected CAS, normal or adjusted hearing and vision, and no comprehension difficulties or other developmental diagnoses. At least 20 children will be randomised to receive one of the two treatments in parallel. Treatments will be delivered by trained and supervised speech pathology clinicians using operationalised manuals. Treatment will be administered in 1-hour sessions, 4 times per week for 3 weeks. The primary outcomes are speech sound and prosodic accuracy on a customised 292 item probe and the Diagnostic Evaluation of Articulation and Phonology inconsistency subtest administered prior to treatment and 1 week, 1 month and 4 months post-treatment. All post assessments will be completed by blinded assessors. Our hypotheses are: 1) treatment effects at 1 week post will be similar for both treatments, 2) maintenance of treatment effects at 1 and 4 months post will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment, and 3) generalisation of treatment effects to untrained related speech behaviours will be greater for Rapid Syllable Transition Treatment than Nuffield Dyspraxia Programme treatment. This protocol was approved by the Human Research Ethics Committee, University of Sydney (#12924).
This will be the first randomised control trial to test treatment for CAS. It will be valuable for clinical decision-making and providing evidence-based services for children with CAS.
Trial Registration
Australian New Zealand Clinical Trials Registry: ACTRN12612000744853
PMCID: PMC3441276  PMID: 22863021
Childhood apraxia of speech; Treatment; Effectiveness; Randomised control trial; Intervention; Rapid syllable transition treatment; Nuffield dyspraxia programme
4.  Secretion of Cryparin, a Fungal Hydrophobin 
Applied and Environmental Microbiology  1999;65(12):5431-5435.
Cryparin is a cell-surface-associated hydrophobin of the filamentous ascomycete Cryphonectria parasitica. This protein contains a signal peptide that directs it to the vesicle-mediated secretory pathway. We detected a glycosylated form of cryparin in a secretory vesicle fraction, but secreted forms of this protein are not glycosylated. This glycosylation occurred in the proprotein region, which is cleaved during maturation by a Kex2-like serine protease, leaving a mature form of cryparin that could be isolated from both the cell wall and culture medium. Pulse-chase labeling experiments showed that cryparin was secreted through the cell wall, without being bound, into the culture medium. The secreted protein then binds to the cell walls of C. parasitica, where it remains. Binding of cryparin to the cell wall occurred in submerged culture, presumably because of the lectin-like properties unique to this hydrophobin. Thus, the binding of this hydrophobin to the cell wall is different from that of other hydrophobins which are reported to require a hydrophobic-hydrophilic interface for assembly.
PMCID: PMC91740  PMID: 10584000

Results 1-4 (4)