Teacher Crisis: Critical Events in the Mid-Career Stage

To understand the ways in which teachers in the mid-career stage might be retained and maintained in the classroom and the profession, this article identifies the critical events in the journey of the mid-career teacher. The findings of a qualitative study that drew on narrative inquiry are used to explore the reasons why 20 mid-career teachers in Queensland, Australia, exited or remained in the classroom and/or profession. The article concludes with a profile of the mid-career teacher which helps to understand how to provide and/or develop job satisfaction and motivation and retain the knowledge, experience and skills of experienced teachers

Snell's Law for a vortex dipole in a Bose-Einstein condensate

A quantum vortex dipole, comprised of a closely bound pair of vortices of equal strength with opposite circulation, is a spatially localized travelling excitation of a planar superfluid that carries linear momentum, suggesting a possible analogy with ray optics. We investigate numerically and analytically the motion of a quantum vortex dipole incident upon a step-change in the background superfluid density of an otherwise uniform two-dimensional Bose-Einstein condensate. Due to the conservation of fluid momentum and energy, the incident and refracted angles of the dipole satisfy a relation analogous to Snell's law, when crossing the interface between regions of different density. The predictions of the analogue Snell's law relation are confirmed for a wide range of incident angles by systematic numerical simulations of the Gross-Piteavskii equation. Near the critical angle for total internal reflection, we identify a regime of anomalous Snell's law behaviour where the finite size of the dipole causes transient capture by the interface. Remarkably, despite the extra complexity of the surface interaction, the incoming and outgoing dipole paths obey Snell's law.Comment: 16 pages, 7 figures, Scipost forma

Development of fluorogenic RNA aptamers for cellular imaging of RNA and genomic loci

In recent years, there has been an explosion of SELEX-evolved fluorescent RNA aptamers, such as Spinach, Broccoli, Corn and Mango. Fluorogenic RNA aptamers have sparked a lot of interest and hold great potential to enable background-free visualisation of RNA molecules in cellular environments. However, their application has been limited by relatively inefficient folding in vivo and fluorescent stability. Therefore, evolving new RNA aptamers with improved brightness and stability should better their use in cellular imaging. Three new Mango-based aptamers have recently been selected from the original Mango RNA SELEX pool using microfluidic- assisted in vitro compartmentalization and fluorescence-activated sorting. This thesis demonstrates the use of these new aptamer variants to image small non-coding RNAs (such as 5S rRNA, U6 snRNA and mgU2-47 scaRNA) in both fixed and live human cells with improved sensitivity and resolution. Upon expression the modified RNAs subcellular localisation pattern is conserved, as validated using immunofluoresence. Recent work with tandem Mango arrays shows increased sensitivity, which enables the visualization of single mRNA molecules in live and fixed cells. Furthermore, it is shown that the tandem Mango arrays don’t affect the expected localization of a cytoplasmic mRNA (β-actin) and the nuclear long non- coding RNA (NEAT-1). Furthermore, these RNA aptamers can also be used to label genomic loci via CRISPR/Cas9 mediated genome targeting with improved contrast. This allows for the targeting of short genomic repeats in a less invasive manner with regards to current methodologies. Taken together this data shows that new Mango aptamers are vastly improved for cellular imaging over previous RNA aptamers, and can in principle be incorporated into a wide range of coding and non-coding RNAs.Open Acces

Live cell imaging of single RNA molecules with fluorogenic Mango II arrays

RNA molecules play vital roles in many cellular processes. Visualising their dynamics in live cells at single-molecule resolution is essential to elucidate their role in RNA metabolism. RNA aptamers, such as Spinach and Mango, have recently emerged as a powerful background-free technology for live-cell RNA imaging due to their fluorogenic properties upon ligand binding. Here, we report a novel array of Mango II aptamers for RNA imaging in live and fixed cells with high contrast and single-molecule sensitivity. Direct comparison of Mango II and MS2-tdMCP-mCherry dual-labelled mRNAs show marked improvements in signal to noise ratio using the fluorogenic Mango aptamers. Using both coding (β-actin mRNA) and long non-coding (NEAT1) RNAs, we show that the Mango array does not affect cellular localisation. Additionally, we can track single mRNAs for extended time periods, likely due to bleached fluorophore replacement. This property makes the arrays readily compatible with structured illumination super-resolution microscopy

Snell's Law for a vortex dipole in a Bose-Einstein condensate

A quantum vortex dipole, comprised of a closely bound pair of vortices of equal strength with opposite circulation, is a spatially localized travelling excitation of a planar superfluid that carries linear momentum, suggesting a possible analogy with ray optics. We investigate numerically and analytically the motion of a quantum vortex dipole incident upon a step-change in the background superfluid density of an otherwise uniform two-dimensional Bose-Einstein condensate. Due to the conservation of fluid momentum and energy, the incident and refracted angles of the dipole satisfy a relation analogous to Snell's law, when crossing the interface between regions of different density. The predictions of the analogue Snell's law relation are confirmed for a wide range of incident angles by systematic numerical simulations of the Gross-Piteavskii equation. Near the critical angle for total internal reflection, we identify a regime of anomalous Snell's law behaviour where the finite size of the dipole causes transient capture by the interface. Remarkably, despite the extra complexity of the interface interaction, the incoming and outgoing dipole paths obey Snell's law.Marsden Fund [UOO1726]; National Science Foundation [PHY-1607243]; Dodd-Walls Centre for Photonic and Quantum TechnologiesOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Snell’s Law and Necklace States for Vortex Dipoles in a Quantum Gas

A quantum vortex is an excitation of a superfluid that carries angular momentum, in which the superfluid is expelled from and circulates around a region known as the vortex core. A quantum vortex dipole consists of two bound quantum vortices with opposite circulation, which together carry linear momentum. The topic of this thesis is two-fold, with a common theme of quantum vortex dipoles. In the first part of the thesis, the motion of a quantum vortex dipole incident upon a step-change in the background superfluid density of an otherwise uniform two-dimensional Bose-Einstein condensate is investigated, both analytically and numerically. Due to the conservation of fluid momentum and energy, the incident and refracted angles of the dipole satisfy a relation analogous to Snell’s law, when crossing the interface between regions of different density. The predictions of the analogue Snell’s law relation are confirmed for a wide range of incident angles by systematic numerical simulations of the Gross-Pitaevskii equation (GPE). Near the critical angle for total internal reflection, we identify a regime of anomalous Snell’s law behaviour where the finite size of the dipole causes transient capture by the interface. Remarkably, despite the extra complexity of the surface interaction, the incoming and outgoing dipole paths obey Snell’s law. In the second part of the thesis, the point-vortex model is used to find the stationary states of an arbitrary neutral number of vortices of alternating sign arranged on a ring in the simply bounded domain. These stationary states are collectively referred to as necklace states, due to the symmetry of their appearance. Curiously, the necklace states are found to have a simple relation to the metallic means, which are generalisations of the golden ratio. The necklace state is numerically simulated with different initial perturbations in both the point-vortex model and the GPE with a comparison of the results. Perturbations from the necklace solution evolve differently in the point-vortex model and GPE due to the healing length scale in the GPE enforcing a departure from the point-vortex model predictions. We introduce a simple numerical scheme to compensate for the healing length and confirm the necklace as a steady of the GPE. We find that the agreement between the point-vortex model and GPE for evolution of significant perturbations persists for longer as the healing length reduces compared to system size

Action research projects 2014-2015: Teachers’ reports - Royal Greenwich Teaching School Alliance (RGTSA)

This year my Colleague, Dr Ana Cabral, and I from the University of Greenwich have had the privilege of working with a group of talented teachers from schools within the Alliance who were all interested to study their own practice in order to enrich the learning of the children they teach. We worked with two core groups. One met at The John Roan School and the other at Thomas Tallis School. The John Roan group was coordinated by Paul Barber and the Tallis group by Andy Smythe. Andy’s group of teachers were interested in studying ways to enrich the teaching of science. The John Roan group were interested in enriching the teaching of literacy. Ana and I wanted to introduce the teachers to action research. The classic work by Carr and Kemmis (1986) describe action research as being about: • the improvement of practice; • the improvement of the understanding of practice; • the improvement of the situation in which the practice takes place. It was important to us that the teachers were systematic about the way they undertook their investigations. Teachers are busy people and the degree to which they applied the methodology varied. We discussed their aims – constructing research questions or identifying the problem they wished to solve. We worked on the best ways of collecting data to inform their actions and we talked about the ethical issues of being an ‘insider--‐researcher’ and how to address them. We met with the teachers at least three times during a term and on a number of occasions we went to schools or had telephone conversations when teachers were too busy to attend. The meetings with the teachers were fascinating. The combination of teachers from secondary and primary led to exciting and fruitful professional conversations. Everyone recognised how pedagogy associated with each phase challenged and enriched the other. In some cases, the teachers invited each other into their classes and team teaching took place as a result, bringing forth further rich professional discussions. Research has informed us that the most effective forms of continuing professional development (CPD) (BERA/RSA 2014) involve: • the use of specialist advisors and external experts • collaborative enquiry and structured peer support • the opportunity to explore why things do and don’t ‘work’ • the exploration and challenging of teachers own beliefs and assumptions (p.25 – 27). ‘All the research indicates that enquiry--‐orientated learning is not a quick--‐fix, but needs to be sustained over time to ensure that learning (for both teachers and pupils) actually takes place’. (BERA/RCA 2014: 26) The RGTSA wants to make this form of teacher-led inquiry part of the practice in their schools. We hope to continue with these powerful projects in the coming years. In this document we provide the reports from the teachers that describe their work. They document the processes with which the teachers were engaged. In most cases teachers collected information from their own surveys or interviews and/or from reading literature in the area. They then describe the action they felt to be appropriate and conclude with a brief evaluation of the success of their projects. They all demonstrate the teachers’ hard work and determination. We would like to extend our thanks to all the teachers and the children involved and especially to Paul Barber and Andy Smythe who helped facilitate the projects. (Andrew Lambirth

The synergistic effect of cigarette taxes on the consumption of cigarettes, alcohol and betel nuts

<p>Abstract</p> <p>Background</p> <p>Consumption of cigarettes and alcoholic beverages creates serious health consequences for individuals and overwhelming financial burdens for governments around the world. In Asia, a third stimulant – betel nuts – increases this burden exponentially. For example, individuals who simultaneously smoke, chew betel nuts and drink alcohol are approximately 123 times more likely to develop oral, pharyngeal and laryngeal cancer than are those who do not.</p> <p>To discourage consumption of cigarettes, the government of Taiwan has imposed three taxes over the last two decades. It now wishes to lower consumption of betel nuts. To assist in this effort, our study poses two questions: 1) Will the imposition of an NT$10 Health Tax on cigarettes effectively reduce cigarette consumption? and 2) Will this cigarette tax also reduce consumption of alcoholic beverages and betel nuts? To answer these questions, we analyze the effect of the NT$10 tax on overall cigarette consumption as well as the cross price elasticities of cigarettes, betel nuts, and alcoholic beverages.</p> <p>Methods</p> <p>To establish the Central Bureau of Statistics demand function, we used cigarette, betel nut, and alcoholic beverage price and sales volume data for the years 1972–2002. To estimate the overall demand price elasticity of cigarettes, betel nuts, and alcoholic beverages, we used a seemingly unrelated regression analysis.</p> <p>Results</p> <p>We find that the NT$10 health tax on cigarettes will reduce cigarette consumption by a significant 27.22$10 health tax on cigarettes will reduce betel nut consumption by 20.07% and alcohol consumption by 7.5%.</p> <p>Conclusion</p> <p>The assessment of a health tax on cigarettes as a smoking control policy tool yields a win-win outcome for both government and consumers because it not only reduces cigarette consumption, but it also reduces betel nut and alcoholic beverage consumption due to a synergistic relationship. Revenues generated by the tax can be used to fund city and county smoking control programs as well as to meet the health insurance system's current financial shortfall.</p