Particle production and transplanckian problem on the non-commutative plane

We consider the coherent state approach to non-commutativity, and we derive from it an effective quantum scalar field theory. We show how the non-commutativity can be taken in account by a suitable modification of the Klein-Gordon product, and of the equal-time commutation relations. We prove that, in curved space, the Bogolubov coefficients are unchanged, hence the number density of the produced particle is the same as for the commutative case. What changes though is the associated energy density, and this offers a simple solution to the transplanckian problem.Comment: Minor typos corrected, references added. Accepted for publication by Modern Physics Letter

Loop and Path Spaces and Four-Dimensional BF Theories: Connections, Holonomies and Observables

We study the differential geometry of principal G-bundles whose base space is the space of free paths (loops) on a manifold M. In particular we consider connections defined in terms of pairs (A,B), where A is a connection for a fixed principal bundle P(M,G) and B is a 2-form on M. The relevant curvatures, parallel transports and holonomies are computed and their expressions in local coordinates are exhibited. When the 2-form B is given by the curvature of A, then the so-called non-abelian Stokes formula follows. For a generic 2-form B, we distinguish the cases when the parallel transport depends on the whole path of paths and when it depends only on the spanned surface. In particular we discuss generalizations of the non-abelian Stokes formula. We study also the invariance properties of the (trace of the) holonomy under suitable transformation groups acting on the pairs (A,B). In this way we are able to define observables for both topological and non-topological quantum field theories of the BF type. In the non topological case, the surface terms may be relevant for the understanding of the quark-confinement problem. In the topological case the (perturbative) four-dimensional quantum BF-theory is expected to yield invariants of imbedded (or immersed) surfaces in a 4-manifold M.Comment: TeX, 39 page

Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

Aspects of Quantum Gravity in Cosmology

We review some aspects of quantum gravity in the context of cosmology. In particular, we focus on models with a phenomenology accessible to current and near-future observations, as the early Universe might be our only chance to peep through the quantum gravity realm.Comment: 15 pages, 1 figure. Invited review for Modern Physics Letter A. Version 2: minor typos corrected, few references adde

Valence band spectroscopy in V-grooved quantum wires

We present a combined theoretical and experimental study of the anisotropy in the optical absorption of V-shaped quantum wires. By means of realistic band structure calculations for these structures, we show that detailed information on the heavy- and light-hole states can be singled out from the anisotropy spectra {\em independently of the electron confinement}, thus allowing accurate valence band spectroscopy.Comment: To be published in Appl. Phys. Lett. (8 pages in REVTeX, two postscipt figures

Immune cells and preterm labour:do invariant NKT cells hold the key?

We have developed our original made-to-measure (M2M) algorithm, PRIMAL, with the aim of modelling the Galactic disc from upcoming Gaia data. From a Milky Way like N-body disc galaxy simulation, we have created mock Gaia data using M0III stars as tracers, taking into account extinction and the expected Gaia errors. In PRIMAL, observables calculated from the N-body model are compared with the target stars, at the position of the target stars. Using PRIMAL, the masses of the N-body model particles are changed to reproduce the target mock data, and the gravitational potential is automatically adjusted by the changing mass of the model particles. We have also adopted a new resampling scheme for the model particles to keep the mass resolution of the N-body model relatively constant. We have applied PRIMAL to this mock Gaia data and we show that PRIMAL can recover the structure and kinematics of a Milky Way like barred spiral disc, along with the apparent bar structure and pattern speed of the bar despite the galactic extinction and the observational errors

Applying university strategic objectives at the school level

University Teachers at the School of Interdisciplinary Studies are working together on the Teaching, Learning and Participation Project. This project encompasses three strands: widening participation, student experience, and innovative learning and teaching; all key aspects of the University’s strategic objectives. The widening participation strand has focused primarily on partnership with local schools. This includes Campus Days whereby pupils who have the ability, but perhaps not the confidence, to enter higher education come to the University's two campuses and experience a day as a student. Additionally this strand is seeking to conduct a comparative study of assessment and feedback processes in secondary and higher education. The student experience strand has concentrated on employability and internationalisation. Examples include working with the local education authority to extend student learning and provide staff CPD opportunities via the establishment of an annual education lecture, and developing opportunities for internships overseas. Finally, the innovative learning and teaching strand has sought to review current teaching practices within the School, and to identify and trial innovative methodologies in an effort to engage learners more fully and thereby to enhance both the student and staff learning experiences

Evaluasi Kapasitas Shelter Evakuasi untuk Bencana Tsunami di Kota Padang Berbasis Sistem Imformasi Geografis (SIG)

Padang city is prone to earthquakes and tsunamis because it lies at the confluence of two Indian and Asian plates . To prepare for the possibility of tsunami, some agencies have made evacuation planning . Marine and Fisheries Department and Tsunami Alert Community plan the building that can be used as an evacuation shelter in Padang . Marine and Fisheries Department has planed for as many as 152 buildings of shelters and Tsunami Alert Community has planed for as many as 93 buildings. This study evaluated the capacity of shelters that planned by Marine and Fisheries Department and Tsunami Alert Community based on geographic information system with respect to the level of accessibility and capacity of shelters. Used to evaluate the level of accessibility of service area concept . Service area in this study means that refugees who are in the area has enough time to reach shelter before the tsunami . Used for the analysis of service area facilities Extension Network Analist contained in ArcGIS software . Assumption which used is if the speed of the evacuation of people walk or run is 3.6 km/hour, the tsunami wave propagation time is 33 minutes and each resident requires an area of 1.65 m2 . In this study concluded that the capacity of the shelter which planned by Marine and Fisheries Department and Tsunami Alert Community is insufficient to accommodate prospective refugees in Padang . Based on data from the latest shelter building and the combination of the number of buildings that planned by Marine and Fisheries Department and Tsunami Alert Community only able to accommodate 75 % of the population residing in the submergence area of the tsunami