Broadening of a nonequilibrium phase transition by extended structural defects

We study the effects of quenched extended impurities on nonequilibrium phase transitions in the directed percolation universality class. We show that these impurities have a dramatic effect: they completely destroy the sharp phase transition by smearing. This is caused by rare strongly coupled spatial regions which can undergo the phase transition independently from the bulk system. We use extremal statistics to determine the stationary state as well as the dynamics in the tail of the smeared transition, and we illustrate the results by computer simulations.Comment: 4 pages, 4 eps figures, final version as publishe

New Longevity Record for Ivory Gulls (Pagophila eburnea) and Evidence of Natal Philopatry

Ivory gulls (Pagophila eburnea) have been listed as “endangered” in Canada and “near threatened” interna-tionally. In June 2010, we visited Seymour Island, Nunavut, Canada, where gulls were banded in the 1970s and 1980s. We recaptured and released two breeding gulls banded as chicks in 1983, confirming natal philopatry to this breeding colony. These gulls are more than 28 years old, making the ivory gull one of the longest-living marine bird species known in North America.La mouette blanche (Pagophila eburnea) figure sur la liste des espèces « en voie de disparition » sur la scène canadienne et des espèces « quasi menacées » sur la scène internationale. En juin 2010, nous sommes allés à l’île Seymour, au Nunavut, Canada, où des mouettes avaient été baguées dans le courant des années 1970 et 1980. Nous avons recapturé et relâché deux mouettes reproductrices qui étaient considérées comme des oisillons en 1983, ce qui nous a permis de confirmer la philopatrie natale de cette colonie de nidification. Ces mouettes blanches ont plus de 28 ans, ce qui en fait l’un des oiseaux aquatiques vivant le plus longtemps en Amérique du Nord

Phase transitions for suspension flows

This paper is devoted to study thermodynamic formalism for suspension flows defined over countable alphabets. We are mostly interested in the regularity properties of the pressure function. We establish conditions for the pressure function to be real analytic or to exhibit a phase transition. We also construct an example of a potential for which the pressure has countably many phase transitions.Comment: Example 5.2 expanded. Typos corrected. Section 6.1 superced the note "Thermodynamic formalism for the positive geodesic flow on the modular surface" arXiv:1009.462

Minimal Flavour Violation and Beyond

Starting from the effective-theory framework for Minimal Flavour Violation, we give a systematic definition of next-to-minimal (quark) flavour violation in terms of a set of spurion fields exhibiting a particular hierarchy with respect to a small (Wolfenstein-like) parameter. A few illustrative examples and their consequences for charged and neutral decays with different quark chiralities are worked out in some detail. Our framework can be used as a model-independent classification scheme for the parameterization of flavour structure from physics beyond the Standard Model.Comment: 17 pages, no figures, phenomenological discussion extended, references adde

DHA Improves Cognition and Prevents Dysfunction of Entorhinal Cortex Neurons in 3xTg-AD Mice

Defects in neuronal activity of the entorhinal cortex (EC) are suspected to underlie the symptoms of Alzheimer's disease (AD). Whereas neuroprotective effects of docosahexaenoic acid (DHA) have been described, the effects of DHA on the physiology of EC neurons remain unexplored in animal models of AD. Here, we show that DHA consumption improved object recognition (↑12%), preventing deficits observed in old 3xTg-AD mice (↓12%). Moreover, 3xTg-AD mice displayed seizure-like akinetic episodes, not detected in NonTg littermates and partly prevented by DHA (↓50%). Patch-clamp recording revealed that 3xTg-AD EC neurons displayed (i) loss of cell capacitance (CC), suggesting reduced membrane surface area; (ii) increase of firing rate versus injected current (F-I) curve associated with modified action potentials, and (iii) overactivation of glutamatergic synapses, without changes in synaptophysin levels. DHA consumption increased CC (↑12%) and decreased F-I slopes (↓21%), thereby preventing the opposite alterations observed in 3xTg-AD mice. Our results indicate that cognitive performance and basic physiology of EC neurons depend on DHA intake in a mouse model of AD

Learning together through international collaboration in teacher education in Malaysia. Report of a project to develop a Bachelor of Education (Honours) in Primary Mathematics

Copyright University of Hertfordshire, School of Education 2011Learning together through international collaboration in teacher education in Malaysia is the report of an enterprising partnership between the University of Hertfordshire, UK, the Ministry of Education Malaysia and two Institutes of Teacher Education in Malaysia. Working collaboratively with colleagues in Malaysia, the University of Hertfordshire School of Education designed, validated, supported and quality assured a Bachelor of Education (Honours) degree programme for initial teacher training for a single cohort of 120 students over four years. All the students graduated in 2010. Learning together through international collaboration in teacher education in Malaysia provides a record of the project itself. It also documents in-depth insights from contributors to the project in two main areas: the collaborative approach to working together and issues relating to learning and teaching, including the Action – Reflection – Modelling (ARM) pedagogical approach, which underpinned the degree programme. Senior managers, teacher educators and lecturers share some of their learning from working together to develop and implement the new degree programme. Student teachers voice some experiences from their school placements. They describe how they used ARM; highlight some of the benefits of the approach and identify some of the challenges associated with introducing a different pedagogy in schools as they were 'learning to teach'. There are glimpses of 'lively and attractive' classes in which 'pupils enjoy and feel comfortable to learn' and 'are eager to answer my questions'. School mentors provide additional insights into the student teachers' learning and teaching practice. The richness of the contributions is reflected in the many quotations included in the report. The successful completion of this project was due to the dedication and expertise of many contributors. The findings documented in this report are relevant for all those engaged in international collaboration and teacher education.Final Published versio

The effect of rare regions on a disordered itinerant quantum antiferromagnet with cubic anisotropy

We study the quantum phase transition of an itinerant antiferromagnet with cubic anisotropy in the presence of quenched disorder, paying particular attention to the locally ordered spatial regions that form in the Griffiths region. We derive an effective action where these rare regions are described in terms of static annealed disorder. A one loop renormalization group analysis of the effective action shows that for order parameter dimensions $p<4$ the rare regions destroy the conventional critical behavior. For order parameter dimensions $p>4$ the critical behavior is not influenced by the rare regions, it is described by the conventional dirty cubic fixed point. We also discuss the influence of the rare regions on the fluctuation-driven first-order transition in this system.Comment: 6 pages RevTe

966-45 QT Dispersion in Essential Hypertension

Increased QT dispersion (QTd) reflects regional variation in ventricular repolarisation, and has been shown in heart failure and hypertrophic cardiomyopathy to relate to an increased incidence of sudden death. As essential hypertensives (EH) are also at increased risk of sudden death we aimed to determine whether increased QTd is found in those EH who are known to be at the highest risk of sudden death. In 50 EH we measured QTd (maximum corrected QT interval minus minimum corrected QT interval), echocardiographic left ventricular mass index (LVMI) (n=46 as 4 patients non-echogenic), office systolic and diastolic blood pressure (SSP, DSP), and 24 hour ambulatory systolic and diastolic blood pressure (24 SSP, 24 DSP) (n=40). Univariate analysis demonstrated no relationship between QTd and age, sex, height, weight, 24 SSP or 24 DBP. Significant relationships existed between QTd and LVMI (R2=0.25, P&lt;0.001), SSP (R2=0.16, P&lt;0.01), DSP (R2=0.08, P&lt;0.05). Multiple linear regression analysis revealed the only relationships to QTd were LVMI (p&lt;0.01) and SSP (p&lt;0.05). Excluding 4 patients with electro-cardiographic left ventricular hypertrophy (ECG-LVH) from the analysis a significant relationship between QTd and LVMI (R2=0.13, P&lt;0.05) and SSP (R2=0.10, P&lt;0.05) persists. These demonstrate that increased QTd is found in EH with the highest risk of sudden death (greatest SSP and LVMI). This relationship persists in the absence of ECG-LVH. Further study of QTd, as a predictor of sudden death in EH is warranted

de-Broglie Wave-Front Engineering

We propose a simple method for the deterministic generation of an arbitrary continuous quantum state of the center-of-mass of an atom. The method's spatial resolution gradually increases with the interaction time with no apparent fundamental limitations. Such de-Broglie Wave-Front Engineering of the atomic density can find applications in Atom Lithography, and we discuss possible implementations of our scheme in atomic beam experiments.Comment: The figures' quality was improved, the text remains intact. 5 pages, 3 figures; submitted to PR

Destructive Adsorption of Carbon Tetrachloride on Alkaline Earth Metal Oxides

The destructive adsorption of CCl4 on MgO, CaO, SrO, and BaO has been studied as a function of the reaction temperature and the amount of CCl4 injected. The reaction was followed using in situ Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and 13 C magic angle spinning nuclear magnetic resonance spectroscopy. It was found that the activity toward CCl4 parallels the basicity of the alkaline earth metal oxide; i.e., the activity decreased in the order BaO > SrO > CaO > MgO. Barium oxide readily reacted with CCl4 at 200-300 °C, and, at these low temperatures, CO2 was the only gas-phase product that evolved from the surface. At higher reaction temperatures, other alkaline earth metal oxides, such as CaO and MgO, also became active, and COCl2 was found to be a reaction intermediate in the destruction of CCl4. Although the destruction process is initiated at the surface, the continuous O 2- /Cl - exchange results in the bulk transformation of the metal oxide to the metal chloride. Barium oxide could be regenerated by dissolving the chloride in water, followed by precipitation as barium carbonate and subsequent calcination. In addition, carbon tetrachloride destruction at around 600 °C resulted in the formation of an unusual alkaline earth metal oxide chloride, viz., M4OCl6 (M ) Ba, Sr, or Ca)