Invasive Allele Spread under Preemptive Competition

We study a discrete spatial model for invasive allele spread in which two alleles compete preemptively, initially only the "residents" (weaker competitors) being present. We find that the spread of the advantageous mutation is well described by homogeneous nucleation; in particular, in large systems the time-dependent global density of the resident allele is well approximated by Avrami's law.Comment: Computer Simulation Studies in Condensed Matter Physics XVIII, edited by D.P. Landau, S.P. Lewis, and H.-B. Schuttler, (Springer, Heidelberg, Berlin, in press

Classical approach in quantum physics

The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom recently discovered with the help of Poincar$\acute{\mathrm{e}}$ section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treating as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well. In conclusion, the relation between quantum theory, classical physics and measurement is discussed.Comment: This review paper was rejected from J.Phys.A with referee's comment "The author has made many worthwhile contributions to semiclassical physics, but this article does not meet the standard for a topical review"

Demagnetization via Nucleation of the Nonequilibrium Metastable Phase in a Model of Disorder

We study both analytically and numerically metastability and nucleation in a two-dimensional nonequilibrium Ising ferromagnet. Canonical equilibrium is dynamically impeded by a weak random perturbation which models homogeneous disorder of undetermined source. We present a simple theoretical description, in perfect agreement with Monte Carlo simulations, assuming that the decay of the nonequilibrium metastable state is due, as in equilibrium, to the competition between the surface and the bulk. This suggests one to accept a nonequilibrium "free-energy" at a mesoscopic/cluster level, and it ensues a nonequilibrium "surface tension" with some peculiar low-T behavior. We illustrate the occurrence of intriguing nonequilibrium phenomena, including: (i) Noise-enhanced stabilization of nonequilibrium metastable states; (ii) reentrance of the limit of metastability under strong nonequilibrium conditions; and (iii) resonant propagation of domain walls. The cooperative behavior of our system may also be understood in terms of a Langevin equation with additive and multiplicative noises. We also studied metastability in the case of open boundaries as it may correspond to a magnetic nanoparticle. We then observe burst-like relaxation at low T, triggered by the additional surface randomness, with scale-free avalanches which closely resemble the type of relaxation reported for many complex systems. We show that this results from the superposition of many demagnetization events, each with a well- defined scale which is determined by the curvature of the domain wall at which it originates. This is an example of (apparent) scale invariance in a nonequilibrium setting which is not to be associated with any familiar kind of criticality.Comment: 26 pages, 22 figure

Loss of viability during freeze-thaw of intact and adherent human embryonic stem cells with conventional slow-cooling protocols is predominantly due to apoptosis rather than cellular necrosis

10.1007/s11373-005-9051-9Journal of Biomedical Science133433-44

Using Enterprise Education to Prepare Healthcare Professional Graduates for the Real-world

Objectives: Every year, HEIs around the world provide an increasing number of graduates with professional degrees in various areas of healthcare including for example medicine, pharmacy, dentistry and podiatry. In most cases, these graduates will get the opportunity to develop a range of generic transferable skills during their HE. Yet, many of these become self-employed or responsible for managing a business, but are not always exposed to curricula that develop their awareness of the concepts of enterprise and entrepreneurship and their role in developing economies and societies, and, thus, do not have the necessary range of enterprise skills that they will need in the real-world, whether employed or self-employed. This paper investigates the extent to which Enterprise Education (EE) is applied at professional health schools at HEIs to develop graduates’ ‘soft’ and ‘functional’ enterprise skills, and how effective the process of delivering this education is. Prior work: Previous literature mainly deals with the application of EE through business and management schools, rather than professional ones. Yet, there is a call for researching EE and skills with more focus on exploring the methods and objectives of specific disciplines. At the same time, research investigating learning in professional degrees focuses almost entirely on the development of technical skills related to the discipline, without a general perspective on developing a wider range of enterprise skills. Approach: The study draws on a qualitative research study in the pharmacy education context. Personal interviews with pharmacy employers and academics were carried out, and thematic analysis was applied to identify themes and codes. Results: Despite that experiential and interactive learning approaches, which can support the development of graduates’ enterprise skills, are applied quite often at pharmacy schools, the application of these approaches is focused on discipline-related material and, therefore, can only support the development of graduates’ ‘soft’ enterprise skills. However, there appears to be resistance against developing graduates’ ‘functional’ enterprise skills in pharmacy disciplines, especially in light of the lack of awareness of the concept of EE among academics. The study offers some possible opportunities/propositions that could facilitate the development of more enterprising healthcare graduates, while highlighting the importance of raising the awareness of academics in this regard and embedding EE as part of schools’ philosophies. Implication: This study should help professional health schools at HEIs decide more accurately on how to develop their graduates’ ‘soft’ and ‘functional’ enterprise skills, and address the needs of the real-world. Value: This study directs the attention of HEIs to support developing professional graduates who are ready for the real-world, and who can support the growth and success of any organisation whether employed or self-employed

Nicotine exploits a COPI-mediated process for chaperone-mediated up-regulation of its receptors

Chronic exposure to nicotine up-regulates high sensitivity nicotinic acetylcholine receptors (nAChRs) in the brain. This up-regulation partially underlies addiction and may also contribute to protection against Parkinson’s disease. nAChRs containing the α6 subunit (α6* nAChRs) are expressed in neurons in several brain regions, but comparatively little is known about the effect of chronic nicotine on these nAChRs. We report here that nicotine up-regulates α6* nAChRs in several mouse brain regions (substantia nigra pars compacta, ventral tegmental area, medial habenula, and superior colliculus) and in neuroblastoma 2a cells. We present evidence that a coat protein complex I (COPI)-mediated process mediates this up-regulation of α6* or α4* nAChRs but does not participate in basal trafficking. We show that α6β2β3 nAChR up-regulation is prevented by mutating a putative COPI-binding motif in the β3 subunit or by inhibiting COPI. Similarly, a COPI-dependent process is required for up-regulation of α4β2 nAChRs by chronic nicotine but not for basal trafficking. Mutation of the putative COPI-binding motif or inhibition of COPI also results in reduced normalized Förster resonance energy transfer between α6β2β3 nAChRs and εCOP subunits. The discovery that nicotine exploits a COPI-dependent process to chaperone high sensitivity nAChRs is novel and suggests that this may be a common mechanism in the up-regulation of nAChRs in response to chronic nicotine

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

Teaching modern foreign languages in multilingual classrooms: an examination of Key Stage 2 teachers’ experiences

The statutory inclusion of modern foreign languages (MFL) into the Key Stage 2 curriculum in England in 2014 aimed to raise the language skills of younger learners in preparation for their secondary education. This change to the curriculum has occurred at a time in which the linguistic diversity within primary schools across the country has been consistently increasing. This study used Interpretative Phenomenological Analysis to qualitatively examine the impact of the curriculum change on teachers implementing it in multilingual classrooms in Greater Manchester. Six teachers with varying experience in teaching MFL participated in semistructured interviews focussing on different aspects of the curriculum change. This paper focuses on the teaching of MFL, as well as on teachers’ perceptions of English as an Additional Language (EAL) pupils’ aptitude for language learning in comparison to their monolingual peers. The superordinate themes identified from the data included the inconsistent delivery of MFL in primary schools, and the role of multilingual classrooms as opportunities for augmented MFL provision. The findings from this study will have implications for teachers, head teachers, and policy-makers regarding the effectiveness of the initial implementation of MFL into the primary curriculum, with specific reference to the EAL school population

Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data

We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross-section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross-sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables, final version to appear in Physical Review