The Psychological Effects of the Voice Change in Female Students and the Implications of Current Pedagogy

The voice change process is a treacherous time, and the female voice change process is underrepresented in literature and often ignored in classrooms (Sweet, 2018). The purpose of this study is to explore the psychological effects of the voice change process in female students and identify current pedagogical trends as used by current secondary choral music educators. Participants included a) Choral music education students who experienced a female voice change and b) Current secondary choral music educators. Choral music education students responded to a background survey which collected voice change process self-efficacy data. Selected informants underwent semi-structured interviews about their voice change experience. Current secondary choral music educators responded to an attitudinal/pedagogical survey of both Likert-type and open-ended prompts. An overarching theme for choral music education students included the aspects of typical adolescent psychological development. This includes perceptions of fear, a “violation of the ensemble” (Sweet, 2015), negative self-efficacy, the “imaginary audience” (Elkind, 1967), and the negative influence from family and teachers. Secondary choral music educators showed differences in levels of preparation and confidence with the female voice change. These findings are most likely directly related to the lack of Social Emotional Learning techniques in past and current classrooms. Applications of this study may continue to inform the field of music education of the effects of the female voice change and pedagogical changes that can be made to lessen negative psychological effects. Future researchers may focus on the effectiveness of pedagogical approaches in use by secondary choral music educators

Pulse pedestal suppression using four-wave mixing in an SOA

Experimental results are presented demonstrating how four-wave mixing in a semiconductor optical amplifier can be used to remove pulse pedestals introduced due to nonlinearities which occur upon pulse propagation in an optical system. Such pedestals would degrade the performance of an optical time-division-multiplexed system due to coherent interaction between channels. An improvement of the temporal pulse suppression ratio to greater than 30 dB is achieved regardless of the level of the pulse pedestal on the input signal. This improvement takes place simultaneously with wavelength conversion and compression of the optical pulse

Numerical analysis of four-wave mixing between 2 ps mode-locked laser pulses in a tensile-strained bulk SOA

A numerical model of four-wave mixing between 2-ps pulses in a tensile-strained bulk semiconductor optical amplifier is presented. The model utilizes a modified Schrodinger equation to model the pulse propagation. The Schrodinger equation parameters such as the material gain first and second order dispersion, linewidth enhancement factors and optical loss coefficient are obtained using a previously developed steady-state model. The predicted four-wave mixing pulse characteristics show reasonably good agreement with experimental pulse characteristics obtained using frequency resolved optical gating

Investigation of optical coherence micro-elastography as a method to visualize micro-architecture in human axillary lymph nodes

This project is supported with funding from the Australian Research Council; and Cancer Council WA, which allowed us to develop the technology; Department of Health of Western Australia, National Breast Cancer Foundation (Australia); and the National Health and Medical Research Council, Australia, which allowed us to design and implement the clinical protocol, and to perform the clinical measurements.Background : Evaluation of lymph node involvement is an important factor in detecting metastasis and deciding whether to perform axillary lymph node dissection (ALND) in breast cancer surgery. As ALND is associated with potentially severe long term morbidity, the accuracy of lymph node assessment is imperative in avoiding unnecessary ALND. The mechanical properties of malignant lymph nodes are often distinct from those of normal nodes. A method to image the micro-scale mechanical properties of lymph nodes could, thus, provide diagnostic information to aid in the assessment of lymph node involvement in metastatic cancer. In this study, we scan axillary lymph nodes, freshly excised from breast cancer patients, with optical coherence micro-elastography (OCME), a method of imaging micro-scale mechanical strain, to assess its potential for the intraoperative assessment of lymph node involvement. Methods : Twenty-six fresh, unstained lymph nodes were imaged from 15 patients undergoing mastectomy or breast-conserving surgery with axillary clearance. Lymph node specimens were bisected to allow imaging of the internal face of each node. Co-located OCME and optical coherence tomography (OCT) scans were taken of each sample, and the results compared to standard post-operative hematoxylin-and-eosin-stained histology. Results : The optical backscattering signal provided by OCT alone may not provide reliable differentiation by inspection between benign and malignant lymphoid tissue. Alternatively, OCME highlights local changes in tissue strain that correspond to malignancy and are distinct from strain patterns in benign lymphoid tissue. The mechanical contrast provided by OCME complements the optical contrast provided by OCT and aids in the differentiation of malignant tumor from uninvolved lymphoid tissue. Conclusion : The combination of OCME and OCT images represents a promising method for the identification of malignant lymphoid tissue. This method shows potential to provide intraoperative assessment of lymph node involvement, thus, preventing unnecessary removal of uninvolved tissues and improving patient outcomes.Publisher PDFPeer reviewe

Volumetric quantitative optical coherence elastography with an iterative inversion method

It is widely accepted that accurate mechanical properties of three-dimensional soft tissues and cellular samples are not available on the microscale. Current methods based on optical coherence elastography can measure displacements at the necessary resolution, and over the volumes required for this task. However, in converting this data to maps of elastic properties, they often impose assumptions regarding homogeneity in stress or elastic properties that are violated in most realistic scenarios. Here, we introduce novel, rigorous, and computationally efficient inverse problem techniques that do not make these assumptions, to realize quantitative volumetric elasticity imaging on the microscale. Specifically, we iteratively solve the three-dimensional elasticity inverse problem using displacement maps obtained from compression optical coherence elastography. This is made computationally feasible with adaptive mesh refinement and domain decomposition methods. By employing a transparent, compliant surface layer with known shear modulus as a reference for the measurement, absolute shear modulus values are produced within a millimeter-scale sample volume. We demonstrate the method on phantoms, on a breast cancer sample ex vivo, and on human skin in vivo. Quantitative elastography on this length scale will find wide application in cell biology, tissue engineering and medicine.Publisher PDFPeer reviewe

Tetrahedral displacive disorder in the scheelite-type oxide RbReO4

Oxides exhibiting the scheelite-type structure are an important class of functional materials with notable applications in photocatalysis, luminescence and ionic conductivity. Like all materials, understanding their atomic structure is fundamental to engineering their physical properties. This study outlines a detailed structural investigation of scheelite-type oxide RbReO4, which exhibits a rare long-range phase transition from I41/a to I41/amd upon heating. Additionally, in the long-range I41/a model, the Re-O tetrahedral distance undergoes significant contraction upon warming. Recent studies of other scheelite oxides have attributed this apparent contraction to incoherent local scale tetrahedral rotations. In this study we use X-ray pair distribution function analysis to show that RbReO4 undergoes a unique symmetry lowering process on the local scale, which involves incoherent tetrahedral displacements. The rare I41/a to I41/amd long-range phase transition was found to occur via a change from static to dynamic disorder on the local scale, which is due to the combination of the size of the A-site cation and lattice expansion. This demonstrates how careful manipulation of the ionic radius of the A-site in the scheelite structure can be used to induce local scale disorder, which has valuable implications for tailoring the physical properties of related materials

Thermal Expansion Behavior in TcO2. Towards breaking the Tc-Tc bond.

The structure of TcO2 between 25 and 1000 °C has been determined in-situ using powder diffraction methods and is found to remain monoclinic in space group P21/c. The thermal expansion in TcO2 is highly anisotropic with negative thermal ex-pansion of the b-axis observed above 700 °C. This is the result of an anomalous expansion along the a-axis that is a consequence of weakening of the Tc-Tc bonds.Australian Synchrotron Australian Research Counci

Towards global sustainability: Education on environmentally clean energy technologies

The recent climate change agreement in Paris highlights the imperative to aggressively decarbonize the energy economy and develop new technologies, especially for the generation of electrical energy that are environmentally clean. This challenge can only be addressed by a multi-pronged approach to research and education of the next generation of scientists and engineers as well as informed public discourse. Consequently this requires the introduction of new and comprehensive education programs on sustainable energy technologies for universities and, possibly, high schools. Among others, the new programs should provide in-depth knowledge in the development of new materials for more efficient energy conversion systems and devices. The enhanced level of education is also needed for properly assessing the competing technologies in terms of their economic and social benefits. The increasing recognition of the significance of clean and efficient energy conversion indicates the need for a comprehensive education program to be developed. The purpose of the present work is to consider the structure of both an education program and the related textbook where the energy-related fundamental and applied subjects are presented in a concentrated and uniform manner. Such a textbook could be an education aid for students of energy-related courses as well as the teachers involved in the formulation of the education programs. The textbook, which should be dedicated mainly for students at the undergraduate levels at universities, and possibly high schools, should include in-depth interdisciplinary sections dedicated to energy experts and graduate students. This paper considers the present international efforts in reducing the impact of climate change and the need to develop new technologies for clean energy generation. It is argued that progress in this area requires recognition of hydrogen as the main energy carrier of the future. This work also delineates the goals of the Sustainable Energy Network, SEN, involved in the UN program of Future Earth

Structure and electronic properties of a mu-oxo ruthenium bromide

The crystal structure of potassium μ-oxo-bis[pentabromoruthenate] K4Ru2OBr10, determined from synchrotron X-ray powder diffraction, is described. Each Ru atom is surrounded by five Br atoms and one O atom. Magnetic measurements show the complex to be diamagnetic as a result of strong Ru–Ru interactions facilitated by the linear Ru–O–Ru linkage

Structure and Magnetism in Sr1-xAxTcO3 Perovskites. The importance of the A-site cation.

The Sr1-xBaxTcO3 (x = 0, 0.1, 0.2) oxides were prepared and their solid-state and magnetic structure studied as a function of the temperature by x-ray and neutron powder diffraction. The refined Tc moments at room temperature and Nèel temperatures for Ba0.1Sr0.9TcO3 and Ba0.2Sr0.8TcO3 were 2.32(14) μβ and 2.11(13) μβ and 714 °C and 702 °C respectively. In contrast to expectations, the Nèel temperature in the series Sr1-xAxTcO3 decreases with increasing Ba content. This observation is consistent with previous experimental measurements for the two series AMO3 (M = Ru, Mn; A = Ca, Sr, Ba) where the maximum magnetic ordering temperature was observed for A = Sr. Taken with these previous results the current work demonstrates the critical role of the A-site cation in the broadening of the π* bandwidth and ultimately the magnetic ordering temperature.Australian Synchrotron Australian Research Counci