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Background and Aim: To date, little research is available that objectively quantifies female adolescent singing-voice characteristics in light of the physiological and functional developments that occur from puberty to adulthood. This exploratory study sought to augment the pool of data available that offers objective voice analysis of female singers in late adolescence. Methods: Using long-term average spectra (LTAS) and inverse filtering techniques, dynamic range and voice-source characteristics were determined in a cohort of vocally healthy cis-gender female adolescent singers (17 to 19 years) from high-school choirs in Aotearoa New Zealand. Non-parametric statistics were used to determine associations and significant differences. Results: Wide intersubject variation was seen between dynamic range, spectral measures of harmonic organisation (formant cluster prominence, FCP), noise components in the spectrum (high-frequency energy ratio, HFER), and the normalised amplitude quotient (NAQ) suggesting great variability in ability to control phonatory mechanisms such as subglottal pressure (Psub), glottal configuration and adduction, and vocal tract shaping. A strong association between the HFER and NAQ suggest that these non-invasive measures may offer complimentary insights into vocal function, specifically with regard to glottal adduction and turbulent noise in the voice signal. Conclusion: Knowledge of the range of variation within healthy adolescent singers is necessary for the development of effective and inclusive pedagogical practices, and for vocal-health professionals working with singers of this age. LTAS and inverse filtering are useful non-invasive tools for determining such characteristics., QC 20230613

A novel hypothesis of optic nerve tethering, which represents a possible cause of primary open-angle glaucoma with normal intraocular pressure, has been motivated by magnetic resonance imaging studies performed in multiple eccentric gaze positions. To evaluate the hypothesis, this thesis reviews the basic anatomical structures of the eye, explores the biomechanical characteristics of ocular tissues, and observes and simulates the phenomenon of optic nerve tethering during adducting eye rotation. While there are many different secondary forms of glaucoma, this thesis mainly considers a pressure-independent contribution to primary open-angle glaucoma. Chapter 1 explains the current state of the glaucoma population, which is steadily increasing every year, and points out what may be a systematic narrowness in thinking in ophthalmology, which emphasizes intraocular pressure as the only known treatment of primary open-angle glaucoma. In Chapter 2, the function, principle, and structure of the ocular globe and optic nerve are briefly reviewed, and the mechanical characteristics of the bilayered optic nerve sheath are explored in depth. In Chapter 3, the mechanical properties of human ocular tissues, which are essential for understanding the biomechanical behavior of the ocular globe, are characterized through uniaxial micro-tensile testing. As an extended study, tensile experiments with and without preconditioning are performed on human ocular tissues to test the necessity for this preconditioning. In addition to the tensile testing, an opto-mechanical correlation between birefringence and tangent modulus of the ocular tissue is discussed as a possible non-invasive method of characterizing tissue. Chapter 4 introduces the hypothesis of optic nerve tethering and summarizes observations from related previous imaging studies. The finite element analysis used in this paper predicts deformation of the optic nerve head and surrounding tissues due to traction by the optic nerve

A novel hypothesis of optic nerve tethering, which represents a possible cause of primary open-angle glaucoma with normal intraocular pressure, has been motivated by magnetic resonance imaging studies performed in multiple eccentric gaze positions. To evaluate the hypothesis, this thesis reviews the basic anatomical structures of the eye, explores the biomechanical characteristics of ocular tissues, and observes and simulates the phenomenon of optic nerve tethering during adducting eye rotation. While there are many different secondary forms of glaucoma, this thesis mainly considers a pressure-independent contribution to primary open-angle glaucoma. Chapter 1 explains the current state of the glaucoma population, which is steadily increasing every year, and points out what may be a systematic narrowness in thinking in ophthalmology, which emphasizes intraocular pressure as the only known treatment of primary open-angle glaucoma. In Chapter 2, the function, principle, and structure of the ocular globe and optic nerve are briefly reviewed, and the mechanical characteristics of the bilayered optic nerve sheath are explored in depth. In Chapter 3, the mechanical properties of human ocular tissues, which are essential for understanding the biomechanical behavior of the ocular globe, are characterized through uniaxial micro-tensile testing. As an extended study, tensile experiments with and without preconditioning are performed on human ocular tissues to test the necessity for this preconditioning. In addition to the tensile testing, an opto-mechanical correlation between birefringence and tangent modulus of the ocular tissue is discussed as a possible non-invasive method of characterizing tissue. Chapter 4 introduces the hypothesis of optic nerve tethering and summarizes observations from related previous imaging studies. The finite element analysis used in this paper predicts deformation of the optic nerve head and surrounding tissues due to traction by the optic nerve

Ice hockey athletes with faster sprint acceleration and change-of-direction (COD) skating performance possess a competitive advantage. However, it is unknown whether joint angle-specific hip strength, in combination with measures known to relate to skating performance (e.g., countermovement jump [CMJ]), better explains skating performance. The purpose of this research was to determine whether hip strength in joint angles specific to skating positions and CMJ performance explains sprint skating acceleration and COD performance. Thirteen semiprofessional male hockey (26.7 ± 6.7 years; 88.4 ± 18.1 kg; 181.9 ± 5.4 cm) athletes were assessed for CMJ performance, hip abduction and adduction strength, 10-m sprint skating acceleration, and COD (505) performance. Linear multiple regressions to predict skating acceleration and COD performance were calculated with variables chosen based on functional justification and magnitude of correlation. Hip abductor relative peak force (rPF) at 25° of hip abduction and CMJ rPF explained 46.0% (adjusted) of variance in sprint acceleration performance (F[2,12] = 6.18, p = 0.02). Countermovement jump peak eccentric velocity, adductor rPF at 50° of hip abduction, and difference in abductor rPF between 50° and 25° of hip abduction explained 85.0% (adjusted) of the variance in 505 time (F[3,12] = 22.8, p < 0.001). Hip strength at joint angles functionally relevant to skating (e.g., at 25° and 50°), in combination with relevant CMJ variables, explained large and very large amounts of variance in sprint skating acceleration and COD performance in this cohort. The inclusion of joint angle-specific hip strength profiling to a physical performance testing battery may provide practitioners with more specific knowledge on the strength of the hip through abduction range of motion, which may affect skating performance.

Secomb, JL, Dascombe, BJ, and Nimphius, S. Importance of joint angle-specific hip strength for skating performance in semiprofessional ice hockey athletes. J Strength Cond Res 35(9): 2599-2603, 2021-Ice hockey athletes with faster sprint acceleration and change-of-direction (COD) skating performance possess a competitive advantage. However, it is unknown whether joint angle-specific hip strength, in combination with measures known to relate to skating performance (e.g., countermovement jump [CMJ]), better explains skating performance. The purpose of this research was to determine whether hip strength in joint angles specific to skating positions and CMJ performance explains sprint skating acceleration and COD performance. Thirteen semiprofessional male hockey (26.7 ± 6.7 years; 88.4 ± 18.1 kg; 181.9 ± 5.4 cm) athletes were assessed for CMJ performance, hip abduction and adduction strength, 10-m sprint skating acceleration, and COD (505) performance. Linear multiple regressions to predict skating acceleration and COD performance were calculated with variables chosen based on functional justification and magnitude of correlation. Hip abductor relative peak force (rPF) at 25° of hip abduction and CMJ rPF explained 46.0% (adjusted) of variance in sprint acceleration performance (F[2,12] = 6.18, p = 0.02). Countermovement jump peak eccentric velocity, adductor rPF at 50° of hip abduction, and difference in abductor rPF between 50° and 25° of hip abduction explained 85.0% (adjusted) of the variance in 505 time (F[3,12] = 22.8, p < 0.001). Hip strength at joint angles functionally relevant to skating (e.g., at 25° and 50°), in combination with relevant CMJ variables, explained large and very large amounts of variance in sprint skating acceleration and COD performance in this cohort. The inclusion of joint angle-specific hip strength profiling to a physical performance testing battery may provide practitioners with more specific knowledge on the strength of the hi

Twang-like vocal qualities have been related to a megaphone-like shape of the vocal tract (epilaryngeal tube and pharyngeal narrowing, and a wider mouth opening), low-frequency spectral changes, and tighter and/or increased vocal fold adduction. Previous studies have focused mainly on loud and high-pitched singing, comfortable low-pitched spoken vowels, or are based on modeling and simulation. There is no data available related to twang-like voices in loud, low-pitched singing. Purpose: This study investigates the possible contribution of the lower and upper vocal tract configurations during loud twang-like singing on high and low pitches in a real subject. Methods: One male contemporary commercial music singer produced a sustained vowel [a:] in his habitual speaking pitch (B2) and loudness. The same vowel was also produced in a loud twang-like singing voice on high (G4) and low pitches (B2). Computerized tomography, acoustic analysis, inverse filtering, and audio-perceptual assessments were performed. Results: Both loud twang-like voices showed a megaphone-like shape of the vocal tract, being more notable on the low pitch. Also, low-frequency spectral changes, a peak of sound energy around 3 kHz and increased vocal fold adduction were found. Results agreed with audio-perceptual evaluation. Conclusions: Loud twang-like phonation seems to be mainly related to low-frequency spectral changes (under 2 kHz) and a more compact formant structure. Twang-like qualities seem to require different degrees of twang-related vocal tract adjustments while phonating in different pitches. A wider mouth opening, pharyngeal constriction, and epilaryngeal tube narrowing may be helpful strategies for maximum power transfer and improved vocal economy in loud contemporary commercial music singing and potentially in loud speech. Further studies should focus on vocal efficiency and vocal economy measurements using modeling and simulation, based on real-singers’ data., QC 20211011

The aims of this study were (a) to describe the kinematics underlying the phenomenon of the knee of the swing leg passing medially in front of the athlete during the single push (SP) phase of the block sprint start, and (b) to determine the relationships between block phase pelvis range of motion (RoM), 1st step width and block phase performance. Three-dimensional kinematic data (250 Hz) were collected from eleven competitive sprinters (100 m PB: 11.17 ± 0.41) performing maximal effort block starts. The joint angles of the rear hip with respect to the pelvis and the pelvis segment angles with respect to the laboratory coordinate system were calculated during the block start phase to the end of the 1st stance. A combination of pelvis list and rotation (not hip adduction) was coupled with the thigh of the swing leg moving medially during the SP phase. A very high positive correlation was found between pelvic list RoM and 1st step width (r = 0.799, p = 0.003). No other significant correlations were found. Attempting to reduce pelvic RoM or changing frontal and transverse plane hip joint angles to minimise medial thigh motion is unlikely to lead to an improvement to performance., QC 20201228

Objective: Using 4-dimensional computed tomographic scanner to determine the motion pattern of the acromioclavicular (AC) joint during adduction of the arm, with and without resisted superior elevation. Method(s): Sixteen healthy volunteers (5 women and 11 men; mean +/- SD age, 42 +/- 11 years). Four different motions were measured: AC joint width, anteroposterior translation, superoinferior translation, and opening of the superior aspect of the joint. Measurements between arm positions of neutral, adduction, and loaded were compared. Result(s): Predominant movement is posterior translation (1.1 +/- 0.9 mm, P = 0.001); in the coronal plane, superior translation of the clavicle (0.6 +/- 0.5 mm, P = 0.001) and some opening of the superior joint space. Changes in the AC joint width and anteroposterior translation were significantly related to age (P = 0.016 and P = 0.006). Conclusion(s): Four-dimensional computed tomographic scans record the motion pattern of an asymptomatic AC joint and demonstrated that in adduction plus resisted elevation of the arm, the main movement of the AC joint is posterior and superior translation of the clavicle. Copyright © 2012 by Lippincott Williams & Wilkins.

Purpose: To systematically study the semiology of psychogenic nonepileptic seizures (PNES) captured by video-electroencephalography (EEG) monitoring (VEM) and categorize the typical patterns observed. Method(s): VEM records of patients who underwent evaluation from January 2002 to June 2007 were reviewed to identify those who had PNES with or without a background of epilepsy. The semiology of each event was visually analyzed and entered into a statistical database. Type of movement, anatomic distribution, synchrony, symmetry, onset, offset, course, duration, vocalization, hyperventilation, eye movements, and responsiveness were evaluated. PNES were classified into distinct groups according to the predominant motor manifestation. Result(s): A total of 330 PNES from 61 patients were studied. Based on semiology, six different types of PNES were observed as follows: (1) rhythmic motor PNES characterized by rhythmic tremor or rigor-like movements (46.7%); (2) hypermotor PNES characterized by violent movements (3.3%); (3) complex motor PNES characterized by complex movements such as flexion, extension, abduction, adduction, rotation, with or without clonic-like and myoclonic-like components of varying combinations and anatomic distribution (10%); (4) dialeptic PNES characterized by unresponsiveness without motor manifestations (11.2%); (5) nonepileptic auras characterized by subjective sensations without any external manifestations, marked in the VEM records as "seizure button presses" (23.6%); and (6) mixed PNES where combinations of above seizure types were seen (5.2%). In a given patient, all the seizures belonged to a single type of PNES in 82% of cases. Discussion(s): PNES can be classified into six stereotypic categories. Contrary to common belief, PNES demonstrates stereotypy both within and across patients. © 2010 International League Against Epilepsy.

Objective: Using 4-dimensional computed tomographic scanner to determine the motion pattern of the acromioclavicular (AC) joint during adduction of the arm, with and without resisted superior elevation. Method(s): Sixteen healthy volunteers (5 women and 11 men; mean +/- SD age, 42 +/- 11 years). Four different motions were measured: AC joint width, anteroposterior translation, superoinferior translation, and opening of the superior aspect of the joint. Measurements between arm positions of neutral, adduction, and loaded were compared. Result(s): Predominant movement is posterior translation (1.1 +/- 0.9 mm, P = 0.001); in the coronal plane, superior translation of the clavicle (0.6 +/- 0.5 mm, P = 0.001) and some opening of the superior joint space. Changes in the AC joint width and anteroposterior translation were significantly related to age (P = 0.016 and P = 0.006). Conclusion(s): Four-dimensional computed tomographic scans record the motion pattern of an asymptomatic AC joint and demonstrated that in adduction plus resisted elevation of the arm, the main movement of the AC joint is posterior and superior translation of the clavicle. Copyright © 2012 by Lippincott Williams & Wilkins.

Purpose: To systematically study the semiology of psychogenic nonepileptic seizures (PNES) captured by video-electroencephalography (EEG) monitoring (VEM) and categorize the typical patterns observed. Method(s): VEM records of patients who underwent evaluation from January 2002 to June 2007 were reviewed to identify those who had PNES with or without a background of epilepsy. The semiology of each event was visually analyzed and entered into a statistical database. Type of movement, anatomic distribution, synchrony, symmetry, onset, offset, course, duration, vocalization, hyperventilation, eye movements, and responsiveness were evaluated. PNES were classified into distinct groups according to the predominant motor manifestation. Result(s): A total of 330 PNES from 61 patients were studied. Based on semiology, six different types of PNES were observed as follows: (1) rhythmic motor PNES characterized by rhythmic tremor or rigor-like movements (46.7%); (2) hypermotor PNES characterized by violent movements (3.3%); (3) complex motor PNES characterized by complex movements such as flexion, extension, abduction, adduction, rotation, with or without clonic-like and myoclonic-like components of varying combinations and anatomic distribution (10%); (4) dialeptic PNES characterized by unresponsiveness without motor manifestations (11.2%); (5) nonepileptic auras characterized by subjective sensations without any external manifestations, marked in the VEM records as "seizure button presses" (23.6%); and (6) mixed PNES where combinations of above seizure types were seen (5.2%). In a given patient, all the seizures belonged to a single type of PNES in 82% of cases. Discussion(s): PNES can be classified into six stereotypic categories. Contrary to common belief, PNES demonstrates stereotypy both within and across patients. © 2010 International League Against Epilepsy.

One of the most devastating effects of tetraplegia is the inability to grasp and manipulate everyday objects necessary to living an independent life. Currently surgery is widely accepted as the solution to improve hand functionality. However, surgery becomes difficult when the user has paralysed wrists as is the case with C5 tetraplegia. The aim of this research was to develop a solution which provided controlled wrist flexion and extension which, when combined with surgery, achieves a 'key pinch' grip. This particular grip is critically important for people with C5 tetraplegia as it is used for countless grasping activities, necessary on a day-to-day basis. A systematic design process was used to evolve the solution to provide controlled wrist flexion and extension. Concept brainstorming identified four alternative solutions which were evaluated to find the preferred concept. The chosen solution was called the Self Powered Wrist Extension Orthosis, more commonly referred to as the 'orthosis'. This concept contained a shoulder harness which provided both energy and control to the wrist harness, which in turn changed the wrist position. The orthosis was developed with the use of a mathematical model which theoretically predicted the functional performance by comparing the required force needed to move the wrist harness to the achievable force supplied by the user's shoulders. Using these parameters, the orthosis was optimized using the matlab Nelder-Mead algorithm which adjusted the wrist harness geometries to maximize the functional performance. A prototype was constructed and tested with the help of two participants who when combined, achieved an average of 18.5° of wrist rotation. The theoretical model however predicted an average range of motion of 28.4°. The discrepancy found between the theoretical and experimental result can be contributed to incorrect assumptions in the theoretical model. This included unaccounted friction and inaccurate modeling of the ortho

SCOPUS: ed.j, info:eu-repo/semantics/published

SCOPUS: ed.j, info:eu-repo/semantics/published

The ability of TNB, DNB and tetryl, to form abducts in rats was investigated using 14C labeled compounds. Our results showed that all three test chemicals(TNB, DNB and tetryl) were able to form abducts with blood proteins and tissue DNA. The optimum time required for maximum adduct formation for TNB, DNB and tetryl varied. For example, TNB abducts (blood proteins and DNA) were maximum at 48 h. Peak levels of DNB abducts (blood proteins) were detected at 8 h and maximum DNB-DNA abducts levels reached by 24 hours. In the case of tetryl the maximum blood protein adduct levels were observed at 24 h, while DNA adducts peaked at 48 h after exposure. The albumin adducts persisted up to two weeks, while globin abducts persisted for ten weeks. At the end of ten weeks significant amount (10-50%) of radioactivity was intact in the DNA of TNB or tetryl treated rat liver, kidney and spleen. 3,5-dinitroaniline was identified from TNB treated rat liver DNA and picric and picramic acids from tetryl treated rat liver and kidney DNA. This suggests that these are the adducts of DNA and released during hydrolysis. In contrast, 3-nitroaniline was identified in hemoglobin hydrolysate as well as in albumin soup from rats treated with DNB. Hence, protein and DNA adducts appear to have promise as dose monitors for nitroaromatic munitions and their by-products.

A rare example of chemospecificity in the tandem Diels-Alder reaction of activated alkynes and bis-dienes has been revealed. The reaction between bis-furyl dienes and DMAD occurs at 25-80 °C and leads to kinetically controlled "pincer" adducts, 4a,8a-disubstituted 1,4:5,8-diepoxynaphthalenes. On the contrary, only thermodynamically controlled "domino" adducts (2,3-disubstituted 1,4:5,8-diepoxynaphthalenes) are formed in the same reaction at 140 °C. The "pincer" adducts can be transformed to the "domino" adducts at heating. The rate constants for reactions of both types were calculated using dynamic 1H NMR spectroscopy. © 2018 American Chemical Society.

Secomb, J. L., Dascombe, B. J., & Nimphius, S. (2021). Importance of joint angle-specific hip strength for skating performance in semiprofessional ice hockey athletes. The Journal of Strength and Conditioning Research, 35(9), 2599-2603. https://doi.org/10.1519/JSC.0000000000004087