Internal solitary waves in the ocean: Analysis using the periodic, inverse scattering transform

The periodic, inverse scattering transform (PIST) is a powerful analytical tool in the theory of integrable, nonlinear evolution equations. Osborne pioneered the use of the PIST in the analysis of data form inherently nonlinear physical processes. In particular, Osborne's so-called nonlinear Fourier analysis has been successfully used in the study of waves whose dynamics are (to a good approximation) governed by the Korteweg--de Vries equation. In this paper, the mathematical details and a new application of the PIST are discussed. The numerical aspects of and difficulties in obtaining the nonlinear Fourier (i.e., PIST) spectrum of a physical data set are also addressed. In particular, an improved bracketing of the "spectral eigenvalues" (i.e., the +/-1 crossings of the Floquet discriminant) and a new root-finding algorithm for computing the latter are proposed. Finally, it is shown how the PIST can be used to gain insightful information about the phenomenon of soliton-induced acoustic resonances, by computing the nonlinear Fourier spectrum of a data set from a simulation of internal solitary wave generation and propagation in the Yellow Sea.Comment: 10 pages, 4 figures (6 images); v2: corrected a few minor mistakes and typos, version accepted for publication in Math. Comput. Simu

Hidden solitons in the Zabusky-Kruskal experiment: Analysis using the periodic, inverse scattering transform

Recent numerical work on the Zabusky--Kruskal experiment has revealed, amongst other things, the existence of hidden solitons in the wave profile. Here, using Osborne's nonlinear Fourier analysis, which is based on the periodic, inverse scattering transform, the hidden soliton hypothesis is corroborated, and the \emph{exact} number of solitons, their amplitudes and their reference level is computed. Other "less nonlinear" oscillation modes, which are not solitons, are also found to have nontrivial energy contributions over certain ranges of the dispersion parameter. In addition, the reference level is found to be a non-monotone function of the dispersion parameter. Finally, in the case of large dispersion, we show that the one-term nonlinear Fourier series yields a very accurate approximate solution in terms of Jacobian elliptic functions.Comment: 10 pages, 4 figures (9 images); v2: minor revision, version accepted for publication in Math. Comput. Simula

Teaching creatively, teaching for creativity : QUT’s Creative Industries Faculty Showcase Panel

In this panel, we showcase approaches to teaching for creativity in disciplines of the Media, Entertainment and Creative Arts School and the School of Design within the Creative Industries Faculty (CIF) at QUT. The Faculty is enormously diverse, with 4,000 students enrolled across a total of 20 disciplines. Creativity is a unifying concept in CIF, both as a graduate attribute, and as a key pedagogic principle. We take as our point of departure the assertion that it is not sufficient to assume that students of tertiary courses in creative disciplines are ‘naturally’ creative. Rather, teachers in higher education must embrace their roles as facilitators of development and learning for the creative workforce, including working to build creative capacity (Howkins, 2009). In so doing, we move away from Renaissance notions of creativity as an individual genius, a disposition or attribute which cannot be learned, towards a 21st century conceptualisation of creativity as highly collaborative, rhizomatic, and able to be developed through educational experiences (see, for instance, Robinson, 2006; Craft; 2001; McWilliam & Dawson, 2008). It has always been important for practitioners of the arts and design to be creative. Under the national innovation agenda (Bradley et al, 2008) and creative industries policy (e.g., Department for Culture, Media and Sport, 2008; Office for the Arts, 2011), creativity has been identified as a key determinant of economic growth, and thus developing students’ creativity has now become core higher education business across all fields. Even within the arts and design, professionals are challenged to be creative in new ways, for new purposes, in different contexts, and using new digital tools and platforms. Teachers in creative disciplines may have much to offer to the rest of the higher education sector, in terms of designing and modelling innovative and best practice pedagogies for the development of student creative capability. Information and Communication Technologies such as mobile learning, game-based learning, collaborative online learning tools and immersive learning environments offer new avenues for creative learning, although analogue approaches may also have much to offer, and should not be discarded out of hand. Each panelist will present a case study of their own approach to teaching for creativity, and will address the following questions with respect to their case: 1. What conceptual view of creativity does the case reflect? 2. What pedagogical approaches are used, and why were these chosen? What are the roles of innovative learning approaches, including ICTs, if any? 3. How is creativity measured or assessed? How do students demonstrate creativity? We seek to identify commonalities and contrasts between and among the pedagogic case studies, and to answer the question: what can we learn about teaching creatively and teaching for creativity from CIF best practice

Crossing over through the recording studio: the Island to Island: Traditional Music from Ireland and Newfoundland CD project

Publisher PD

Editorial

No abstract available

Directive Versus Supportive Approaches Used by Midwives When Providing Care During the Second Stage of Labor

Introduction: Although the risks associated with using sustained and forceful maternal bearing‐down efforts during the second stage of labor have been well documented, most women who give birth in the United States bear down in response to direction from care providers about when and how to push rather than in response to their own physiologic urges. The purpose of this study was to describe the practices used by certified nurse‐midwives/certified midwives (CNMs/CMs) in response to maternal bearing‐down efforts when caring for women in second‐stage labor and to identify factors associated with the use of supportive approaches to second‐stage labor care. Methods: A national survey of 705 CNMs/CMs was conducted using mailed questionnaires. The instrument was an 84‐item, fixed‐choice questionnaire using Likert type scales that had been validated. A 72.6% response rate was achieved, and 375 of the respondents cared for women during the second stage of labor. Results: Most CNMs/CMs (82.4%) often or almost always supported women without epidural anesthesia to initiate bearing‐down efforts only when the woman felt an urge to do so. When caring for women without an epidural, most of the respondents (67%) reported that they often or almost always supported a woman\u27s spontaneous bearing‐down efforts without providing direction. Most participants reported using more directive practices when caring for women with epidural anesthesia. Whether caring for women with or without an epidural, most respondents (77.1% and 79.6%, respectively) often or almost always provided more direction as the fetal head emerged and the final stretching of the perineum was taking place. A change in fetal heart tones that led the midwife to believe the birth needed to occur quickly was the circumstance that had the greatest degree of influence on the participant\u27s (90.6%) decision to provide more direction during bearing‐down efforts. Many participants indicated that they also were influenced to provide more direction when women in labor asked for more direction (73.3%) or appeared to be fatigued (74.6%). Discussion: The majority of CNMs/CMs use supportive approaches to bearing‐down efforts during second‐stage labor care and most used directive approaches as an intervention aimed at avoiding potential problems

Why lifelong learning and why learning cities?

This article is based on a keynote presentation made in May 2014 at the Townsville Learning Cities conference in Australia, one of a series of regional events organized by the Australian Learning Community Network. The presentation sought to answer a series of specific questions that had been posed by the city of Townsville as follows: What are the Community benefits of a local government emphasis on lifelong learning? How do we engage youth in learning? How do we reengage adults in learning after formal learning? How do we maintain engagement in learning throughout the life-course? What examples exist internationally for maintaining community participation in learning? This is a specific example of one small city in Australia, but the issues raised might pertain to many other cities in the world

Acetaldehyde metabolism by wine lactic acid bacteria and its oenological implications : a thesis presented in fulfillment of the requirements for the degree of Master of Science in Microbiology at Massey University

Acetaldehyde is one of the most important sensory carbonyl compounds formed during vinification. Excess acetaldehyde can adversely affect the flavour of wine and acetaldehyde plays a role in the colour development of red wines. Excess acetaldehyde is usually masked by the addition of sulphur dioxide (SO2) to the wine (SO2 is also used as an antimicrobial and antioxidant agent in wine and acetaldehyde bound SO2 is less effective in these roles). To date there has been no definitive study of the impact of wine LAB on free and bound acetaldehyde. Therefore, this study investigated the metabolism of free and bound acetaldehyde and its oenological implications. A survey of 11 commercial malolactic starter cultures (mostly Oenococcus oeni strains) showed that 9 out of 11 were able to metabolise acetaldehyde (in a resting state) with the corresponding formation of ethanol and acetic acid as products. SO2 bound acetaldehyde was also metabolised by the two strains tested (Lactobacillus buchneri CUC-3 and Oenococcus oeni MCW). This is the first evidence that LAB can indeed catabolise SO2 bound acetaldehyde, therefore releasing free SO2. During growth Oenococcus oeni EQ54 and Oenococcus oeni VFO were able to metabolise free acetaldehyde in wine at pH 3.3 and pH 3.6. In wine containing SO2 bound acetaldehyde, Oenococcus oeni EQ54 and Oenococcus oeni VFO were able to metabolise SO2 bound acetaldehyde at pH 3.6 after a period of sluggish growth. At pH 3.3 there was no metabolism of SO2 bound acetaldehyde by Oenococcus oeni EQ54 and Oenococcus oeni VFO during the incubation period. Results from growth experiments showed that in broth there was inhibition of growth at 300 mg/L concentration of acetaldehyde for all strains. In wine, no significant inhibition or stimulation of the cultures examined was found at any acetaldehyde concentrations up to 300 mg/L. In a simultaneous resting cell incubation of Saccharomyces bayanus Première Cuvée and Oenococcus oeni Lol11, acetaldehyde produced by the yeast was metabolised by the wine LAB. The metabolism of acetaldehyde by wine LAB is expected to influence wine flavour as small amounts of ethanol and acetic acid are produced and acetaldehyde is removed. This removal of acetaldehyde by wine LAB suggests that less SO2 will need to be added to the wine to mask excess acetaldehyde when malolactic fermentation is performed. Inhibition of wine LAB growth in broth by high levels of acetaldehyde suggests a role for acetaldehyde in stuck or sluggish MLF. Sluggish growth in wine containing SO2 bound acetaldehyde also suggests a possible role of SO2 bound acetaldehyde in stuck and sluggish MLF. This is due to the release of free SO2 through the metabolism of the acetaldehyde moiety of SO2 bound acetaldehyde