Dynamics of Bose-Einstein condensates in double-well potentials

We study the dynamics of Bose-Einstein condensates in symmetric double-well potentials following a sudden change of the potential from the Mott-insulator to the superfluid regime. We introduce a continuum approximation that maps that problem onto the wave-packet dynamics of a particle in an anharmonic effective potential. For repulsive two-body interactions the visibility of interference fringes that result from the superposition of the two condensates following a stage of ballistic expansion exhibits a collapse of coherent oscillations onto a background value whose magnitude depends on the amount of squeezing of the initial state. Strong attractive interactions are found to stabilize the relative number dynamics. We visualize the dynamics of the system in phase space using a quasiprobability distribution that allows for an intuitive interpretation of the various types of dynamics.

Windows into practice: constructing effective science teaching and learning in a school change initiative

This paper outlines the development of a framework - the Science in Schools (SiS) Components - that describes effective science teaching and learning and that has become a central focus for the Science in Schools Research project that is being implemented in 225 Australian schools. The description is in a form that provides a basis for monitoring change, and which can be validated against project outcomes. The SiS Components were partially based on interviews with a small number of primary and secondary teachers identified as effective practitioners, and have been subject to a variety of validation processes. The focus of this paper is on a particular form of validation involving interviews with an expanded set of effective primary teachers, from three Australian states. Case descriptions of core elements of these teachers' beliefs and practice were constructed, and a review and mapping process used to examine the extent to which the SiS Components, as a distinct 'window into practice', align with and capture these core elements, and differentiate the practice of these effective teachers from other primary teachers in the project.

Teaching practices for effective cooperative learning in an online learning environment (OLE)

As a teaching practice the application of cooperative learning in tertiary education can present unique challenges for both the practitioner and her students. Mastering this teaching approach requires careful planning, design and implementation for effective deployment in a face-to-face setting. In this setting the success of the cooperative learning approach has been demonstrated. The complexity is significantly increased by additional variables such as the selection and application of technological teaching tools and the change in nature of existing variables including awareness of students' social and communication skills when applying this practice in an Online Learning Environment (OLE). In addition student acceptance of this e-learning approach to learning also needs to be carefully considered. The practitioner must be aware of these factors and have suitable methods in place to support collaboration and interaction between student groups to ensure the ultimate goal with regard to students' learning is achieved. This paper considers how cooperative learning can be combined effectively with these variables and factors of an OLE, and begins with the presentation of a conceptual framework to represent this relationship as a constructive teaching practice. It is anticipated that the conceptual framework would be applied by other practitioners to facilitate cooperative teaching within their OLE. To demonstrate the validity of the framework a case scenario is provided using an Information Technology (IT) undergraduate unit named 'IT Practice'. This is a wholly online unit where extensive participation by the students within small groups is a core requirement. The paper demonstrates the themes of designing curriculum and assessment, as well as flexible teaching strategies for learner diversity but primarily concentrates on managing an effective OLE; that is managing small groups in an online teaching environment.

A comparative study of effectiveness of peer assessment of individuals’ contributions to group projects in undergraduate construction management core units

In recent years, various forms of group work have been introduced in university courses across various subject domains, including construction management courses. Although the use of group work in higher education has sound pedagogical reasons and advantages, group work has its own drawbacks. Therefore, the acceptance by students and the success of group work critically depend on a fair and credible assessment of the group process. In this paper, the implementation of different approaches to peer assessment (PA) of individuals’ contributions to group projects in two core units in an undergraduate construction management course in an Australian university is reported. The effectiveness of the adopted PA approaches have been evaluated and validated by students. It has been found that contrary to doubts of the sufficiency of a simplistic approach to PAs, the fairness of a PA approach does not necessarily depend on its complexity. Besides, voluntary group discussions, learning and collaboration are found to aid in improving each of the group’s camaraderie. Hence, it is recommended that academics should develop both a structured methodology to progressively encourage group members to work cohesively in teams and effective PA approaches that measure individual member’s contribution.

Identifying the core competencies of mental health telephone triage

Aims and objectives. The primary aim of this study was to identify the core competencies of mental health telephone triage, including key role tasks, skills, knowledge and responsibilities, in which clinicians are required to be competent to perform safe and effective triage.
Background. Recent global trends indicate an increased reliance on telephone-based health services to facilitate access to health care across large populations. The trend towards telephone-based health services has also extended to mental health settings, evidenced by the growing number of mental health telephone triage services providing 24-hour access to specialist mental health assessment and treatment. Mental health telephone triage services are critical to the early identification of mental health problems and the provision of timely, appropriate interventions. In spite of the rapid growth in mental health telephone triage and the important role these services play in the assessment and management of mental illness and related risks, there has been very little research investigating this area of practice.
Design. An observational design was employed to address the research aims.
Methods. Structured observations (using dual wireless headphones) were undertaken on 197 occasions of mental health telephone triage over a three-month period from January to March 2011.
Results. The research identified seven core areas of mental health telephone triage practice in which clinicians are required to be competent in to perform effective mental health telephone triage, including opening the call; performing mental status examination; risk assessment; planning and action; termination of call; referral and reporting; and documentation.
Conclusions. The findings of this research contribute to the evidence base for mental health telephone triage by articulating the core competencies for practice. Relevance to clinical practice. The mental health telephone triage competencies identified in this research may be used to define an evidence-based framework for mental health telephone triage practice that aims to improve the quality, consistency and accuracy of telephone-based mental health triage assessment.

The electrochemical surface forces apparatus : the effect of surface roughness, electrostatic surface potentials, and anodic oxide growth on interaction forces, and friction between dissimilar surfaces in aqueous solutions

We present a newly designed electrochemical surface forces apparatus (EC-SFA) that allows control and measurement of surface potentials and interfacial electrochemical reactions with simultaneous measurement of normal interaction forces (with nN resolution), friction forces (with μN resolution), and distances (with Å resolution) between apposing surfaces. We describe three applications of the developed EC-SFA and discuss the wide-range of potential other applications. In particular, we describe measurements of (1) force–distance profiles between smooth and rough gold surfaces and apposing self-assembled monolayer-covered smooth mica surfaces; (2) the effective changing thickness of anodically growing oxide layers with Å-accuracy on rough and smooth surfaces; and (3) friction forces evolving at a metal–ceramic contact, all as a function of the applied electrochemical potential. Interaction forces between atomically smooth surfaces are well-described using DLVO theory and the Hogg–Healy–Fuerstenau approximation for electric double layer interactions between dissimilar surfaces, which unintuitively predicts the possibility of attractive double layer forces between dissimilar surfaces whose surface potentials have similar sign, and repulsive forces between surfaces whose surface potentials have opposite sign. Surface roughness of the gold electrodes leads to an additional exponentially repulsive force in the force–distance profiles that is qualitatively well described by an extended DLVO model that includes repulsive hydration and steric forces. Comparing the measured thickness of the anodic gold oxide layer and the charge consumed for generating this layer allowed the identification of its chemical structure as a hydrated Au(OH)3 phase formed at the gold surface at high positive potentials. The EC-SFA allows, for the first time, one to look at complex long-term transient effects of dynamic processes (e.g., relaxation times), which are also reflected in friction forces while tuning electrochemical surface potentials.

UnitingWorld : Partnership for effective involvement in mission including development

This chapter argues that, both theologically and practically, development is a form of mission and therefore dividing 'mission' and 'development' is artificial. A theological understanding of mission clearly incorporates upholding rights especially of people most excluded and vulnerable, the core task of development.One church agency involved in both development and supporting partners in communicating the gospel is UnitingWorld – the national agency of the Uniting Church in Australia responsible for international partnerships including development. The Uniting Church was formed in 1977 from the merging of three denominations, all of which had a long history of overseas engagement – for example with Fiji since 1844 and Korea since 1889. Such partnerships have endured and spread to the point where the Uniting Church now has thirty six formal partners, mainly in the Pacific and Asia.Over the past 20 years, a range of social trends, such as decolonisation, climate change, and increased global commitment to justice, as well as changes in missiological thinking, have influenced collaboration with indigenous churches as well as organisations not explicitly Christian.Recolonising approaches by international inter-government bodies and by the Australian government through promoting predominantly western neo-liberal economic values to neighbours, invites the church to collaborate in valuing partner cultures, spiritualities, values and world-views. For UnitingWorld this is most evident in its Pacific engagement, especially with programs arising from the Pacific Conference of Churches.These factors have further relativised the tensions between what was seen as “mission” and what was seen as “development”. Evangelism as communication of good news exhibits a different hue – now coming out of the natural conversations between partners and speaking of God’s life- giving alternatives to destructive social and economic models. Whilst development is inherent in mission, the major challenge faced by UnitingWorld is with Protestant partners strongly influenced by an era of church teaching that emphasised personal commitment tied to distinctive religious expressions.In this chapter we use case studies from the Pacific to show how UnitingWorld is partnering with a range of church and other organisations to support people in exercising their rights and re-engaging Australian church communities in this task.

Locked nucleic acid modified bi-specific aptamer-targeted nanoparticles carrying survivin antagonist towards effective colon cancer therapy

We investigated the anti-cancer activity of alginate coated chitosan nanoparticles (CHNP) encapsulating cell-permeable dominant negative survivin (SR9) with locked nucleic acid (LNA) aptamers targeting EpCAM and nucleolin (termed as "nanobullets") in vitro (2D and 3D cell culture models) and in vivo (colon cancer mouse xenograft model). We incorporated three LNA modifications in each sequence in order to enhance the stability of these aptamers. Confocal microscopy revealed binding of the LNA-aptamers to their specific markers with high affinity. The muco-adhesive nanobullets showed 6-fold higher internalization in cancer cells when compared to non-cancerous cells, suggesting a tumour specific uptake. A higher intensity of nanobullets was observed in both the periphery and the core of the multicellular tumour spheroids compared to non-targeted CHNP-SR9. The nanobullets were found to be the highly effective as they led to a 2.26 fold (p < 0.05) reduction at 24 h and a 4.95 fold reduction (p ≤ 0.001) in the spheroid size at 72 h. The tumour regression was 4 fold higher in mice fed on a nanobullet diet when compared to a control diet. The nanobullets were able to show a significantly high apoptotic (p ≤ 0.0005) and necrotic index in the tumour cell population (p ≤ 0.005) when compared to void NPs. Therefore, our nanoparticles have shown highly promising results and therefore deliver a new conduit towards the approach of cancer-targeted nanodelivery. This journal is

Bounded solutions of fermions in the background of mixed vector-scalar inversely linear potentials

The problem of a fermion subject to a general mixing of vector and scalar potentials in a two-dimensional world is mapped into a Sturm-Liouville problem. Isolated bounded solutions are also searched. For the specific case of an inversely linear potential, which gives rise to an effective Kratzer potential in the Sturm-Liouville problem, exact bounded solutions are found in closed form. The case of a pure scalar potential with their isolated zero-energy solutions, already analyzed in a previous work, is obtained as a particular case. The behavior of the upper and lower components of the Dirac spinor is discussed in detail and some unusual results are revealed. The nonrelativistic limit of our results adds a new support to the conclusion that even-parity solutions to the nonrelativistic one-dimensional hydrogen atom do not exist. (c) 2004 Elsevier B.V. All rights reserved.

Bounded solutions of fermions in the background of mixed vector-scalar Poeschl-Teller-like potentials

The problem of a fermion subject to a convenient mixing of vector and scalar potentials in a two-dimensional space-time is mapped into a Sturm-Liouville problem. For a specific case which gives rise to an exactly solvable effective modified Poschl-Teller potential in the Sturm-Liouville problem, bound-state solutions are found. The behaviour of the upper and lower components of the Dirac spinor is discussed in detail and some unusual results are revealed. The Dirac delta potential as a limit of the modified Poschl-Teller potential is also discussed. The problem is also shown to be mapped into that of massless fermions subject to classical topological scalar and pseudoscalar potentials. Copyright (C) EPLA, 2007.

Bounded solutions for nonconserving-parity pseudoscalar potentials

The Dirac equation is analyzed for nonconserving-parity pseudoscalar radial potentials in 3+1 dimensions. It is shown that despite the nonconservation of parity this general problem can be reduced to a Sturm-Liouville problem of nonrelativistic fermions in spherically symmetric effective potentials. The searching for bounded solutions is done for the power-law and Yukawa potentials. The use of the methodology of effective potentials allow us to conclude that the existence of bound-state solutions depends whether the potential leads to a definite effective potential-well structure or to an effective potential less singular than -1/4r(2).

Klein-Gordon particles in mixed vector-scalar inversely linear potentials

The problem of a spinless particle subject to a general mixing of vector and scalar inversely linear potentials in a two-dimensional world is analyzed. Exact bounded solutions are found in closed form by imposing boundary conditions on the eigenfunctions which ensure that the effective Hamiltonian is Hermitian for all the points of the space. The nonrelativistic limit of our results adds a new support to the conclusion that even-parity solutions to the nonrelativistic one-dimensional hydrogen atom do not exist. (c) 2005 Elsevier B.V. All rights reserved.

Trapping neutral fermions with kink-like potentials

The intrinsically relativistic problem of neutral fermions subject to kink-like potentials (similar to tanh gamma x) is investigated and the exact bound-state solutions are found. Apart from the lonely hump solutions for E = +/- mc(2), the problem is mapped into the exactly solvable Sturm-Liouville problem with a modified Poschl-Teller potential. An apparent paradox concerning the uncertainty principle is solved by resorting to the concepts of effective mass and effective Compton wavelength. (c) 2005 Elsevier B.V. All rights reserved.

Bound states of bosons and fermions in a mixed vector-scalar coupling with unequal shapes for the potentials

The Klein - Gordon and the Dirac equations with vector and scalar potentials are investigated under a more general condition, V(v) + V(s) = constant. These intrinsically relativistic and isospectral problems are solved in the case of squared hyperbolic potential functions and bound states for either particles or antiparticles are found. The eigenvalues and eigenfuntions are discussed in some detail and the effective Compton wavelength is revealed to be an important physical quantity. It is revealed that a boson is better localized than a fermion when they have the same mass and are subjected to the same potentials.

Nonpolynomial potentials with deformable topological structures

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