Notes on the description of join-distributive lattices by permutations

Let L be a join-distributive lattice with length n and width (Ji L) k. There are two ways to describe L by k − 1 permutations acting on an n-element set: a combinatorial way given by P.H. Edelman and R. E. Jamison in 1985 and a recent lattice theoretical way of the second author. We prove that these two approaches are equivalent. Also, we characterize join-distributive lattices by trajectorie

Structural phase transitions and their influence on Cu+ mobility in superionic ferroelastic Cu6PS5I single crystals

The structural origin of Cu+ ions conductivity in Cu6PS5I single crystals is described in terms of structural phase transitions studied by X-ray diffraction, polarizing microscope and calorimetric measurements. Below the phase transition at Tc=(144-169) K Cu6PS5I belongs to monoclinic, ferroelastic phase, space group Cc. Above Tc crystal changes the symmetry to cubic superstructure, space group F-43c (a=19.528); finally at 274K disordering of the Cu+ ions increases the symmetry to F-43m, (a=9.794). The phase transition at 274K coincides well with a strong anomaly in electrical conductivity observed in the Arrhenius plot. Diffusion paths for Cu+ ions are evidenced by means of the atomic displacement factors and split model. Influence of the copper stechiometry on the Tc is also discussed.Comment: conference pape

The Ecological and Ethical Consumption Development Prospects in Poland Compared with the Western European Countries

An overview of the Western European literature shows that one of the most distinct trends in consumption that has been noted in the recent years is globally increasing environmental and social awareness. The issue of consumers' behaviours and attitudes towards "socially responsible products" has been gaining importance in Polish economy as well. This article evaluates the development prospects of ethical and ecological consumption in Poland vis-à-vis Western European countries. The comparative analysis being part of the article utilizes primary sources of information, i.e. interviews with a representative sample of Polish adults, as well as secondary sources of information. A factor analysis or, more precisely, a principal component analysis, allowed dividing Polish consumers into groups that were typologically homogeneous in respect of their sensitivity to various aspects of business ethics and ecology.Przegląd literatury zachodnio-europejskiej pozwala stwierdzić, że jednym z najbardziej zauważalnych trendów w sferze konsumpcji w ostatnich latach jest coraz większa świadomość ekologiczna i społeczna w wymiarze globalnym. Problematyka zachowań i postaw konsumentów wobec produktów "społecznie odpowiedzialnych" nabiera coraz większego znaczenia także w polskiej gospodarce. Celem artykułu jest ocena perspektyw rozwoju etyczneji ekologicznej konsumpcji w Polsce na tle krajów zachodnio-europejskich. Analizę porównawczą prowadzono bazując na źródłach wtórych jak i badaniach pierwotnych realizowanych na reprezentatywnej próbie losowej dorosłych mieszkańców Polski. W oparciu o analizę czynnikową, a dokładniej metodę analizy głównych składowych, dokonano także podziału polskich konsumentów na jednorodne grupy typologiczne pod względem ich wrażliwości na różne aspekty związane z ekologią i etyką

Automatic generation of multi-precision multi-arithmetic CNN accelerators for FPGAs

Modern deep Convolutional Neural Networks (CNNs) are computationally demanding, yet real applications often require high throughput and low latency. To help tackle these problems, we propose Tomato, a framework designed to automate the process of generating efficient CNN accelerators. The generated design is pipelined and each convolution layer uses different arithmetics at various precisions. Using Tomato, we showcase state-of-the-art multi-precision multi-arithmetic networks, including MobileNet-V1, running on FPGAs. To our knowledge, this is the first multi-precision multi-arithmetic auto-generation framework for CNNs. In software, Tomato fine-tunes pretrained networks to use a mixture of short powers-of-2 and fixed-point weights with a minimal loss in classification accuracy. The fine-tuned parameters are combined with the templated hardware designs to automatically produce efficient inference circuits in FPGAs. We demonstrate how our approach significantly reduces model sizes and computation complexities, and permits us to pack a complete ImageNet network onto a single FPGA without accessing off-chip memories for the first time. Furthermore, we show how Tomato produces implementations of networks with various sizes running on single or multiple FPGAs. To the best of our knowledge, our automatically generated accelerators outperform closest FPGA-based competitors by at least 2-4x for lantency and throughput; the generated accelerator runs ImageNet classification at a rate of more than 3000 frames per second.EPSRC Doctoral Scholarship Peterhouse Graduate Studentshi

Rmi1 stimulates decatenation of double Holliday junctions during dissolution by Sgs1-Top3

double Holliday junction (dHJ) is a central intermediate of homologous recombination that can be processed to yield crossover or non-crossover recombination products. To preserve genomic integrity, cells possess mechanisms to avoid crossing over. We show that Saccharomyces cerevisiae Sgs1 and Top3 proteins are sufficient to migrate and disentangle a dHJ to produce exclusively non-crossover recombination products, in a reaction termed "dissolution." We show that Rmi1 stimulates dHJ dissolution at low Sgs1-Top3 protein concentrations, although it has no effect on the initial rate of Holliday junction (HJ) migration. Rmi1 serves to stimulate DNA decatenation, removing the last linkages between the repaired and template DNA molecules. Dissolution of a dHJ is a highly efficient and concerted alternative to nucleolytic resolution that prevents crossing over of chromosomes during recombinational DNA repair in mitotic cells and thereby contributes to genomic integrity

Enhanced 99Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

Technetium (99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Because reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals, two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 and 1000 °C. After being cooled, the solid glass specimens prepared at different temperatures at 600, 800, and 1000 °C were analyzed for Tc oxidation state using Tc K-edge XANES. In most samples, Tc was partially (<60%) oxidized from Tc(IV) to Tc(VII) as the melt temperature increased up to 600 °C. However, most of Tc(IV) was completely (>95%) oxidized to Tc(VII) at temperature above 800 °C. Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were slightly higher (∼10%) than in glass prepared using KTcO4 because of limited and delayed Tc volatilization

Gauge-theoretic invariants for topological insulators: A bridge between Berry, Wess-Zumino, and Fu-Kane-Mele

We establish a connection between two recently-proposed approaches to the understanding of the geometric origin of the Fu-Kane-Mele invariant $\mathrm{FKM} \in \mathbb{Z}_2$, arising in the context of 2-dimensional time-reversal symmetric topological insulators. On the one hand, the $\mathbb{Z}_2$ invariant can be formulated in terms of the Berry connection and the Berry curvature of the Bloch bundle of occupied states over the Brillouin torus. On the other, using techniques from the theory of bundle gerbes it is possible to provide an expression for $\mathrm{FKM}$ containing the square root of the Wess-Zumino amplitude for a certain $U(N)$-valued field over the Brillouin torus. We link the two formulas by showing directly the equality between the above mentioned Wess-Zumino amplitude and the Berry phase, as well as between their square roots. An essential tool of independent interest is an equivariant version of the adjoint Polyakov-Wiegmann formula for fields $\mathbb{T}^2 \to U(N)$, of which we provide a proof employing only basic homotopy theory and circumventing the language of bundle gerbes.Comment: 23 pages, 1 figure. To appear in Letters in Mathematical Physic

The specialty choices of graduates from Brighton and Sussex Medical School: a longitudinal cohort study

BACKGROUND Since 2007 junior doctors in the UK have had to make major career decisions at a point when previously many had not yet chosen a specialty. This study examined when doctors in this new system make specialty choices, which factors influence choices, and whether doctors who choose a specialty they were interested in at medical school are more confident in their choice than those doctors whose interests change post-graduation. METHODS Two cohorts of students in their penultimate year at one medical school (n = 227/239) were asked which specialty interested them as a career. Two years later, 210/227 were sent a questionnaire measuring actual specialty chosen, confidence, influence of perceptions of the specialty and experiences on choice, satisfaction with medicine, personality, self-efficacy, and demographics. Medical school and post-graduation choices in the same category were deemed 'stable'. Predictors of stability, and of not having chosen a specialty, were calculated using bootstrapped logistic regression. Differences between specialties on questionnaire factors were analysed. RESULTS 50% responded (n = 105/277; 44% of the 239 Year 4 students). 65% specialty choices were 'stable'. Factors univariately associated with stability were specialty chosen, having enjoyed the specialty at medical school or since starting work, having first considered the specialty earlier. A regression found doctors who chose psychiatry were more likely to have changed choice than those who chose general practice. Confidence in the choice was not associated with stability. Those who chose general practice valued lifestyle factors. A psychiatry choice was associated with needing a job and using one's intellect to help others. The decision to choose surgical training tended to be made early. Not having applied for specialty training was associated with being lower on agreeableness and conscientiousness. CONCLUSION Medical school experiences are important in specialty choice but experiences post-graduation remain significant, particularly in some specialties (psychiatry in our sample). Career guidance is important at medical school and should be continued post-graduation, with senior clinicians supported in advising juniors. Careers advice in the first year post-graduation may be particularly important, especially for specialties which have difficulty recruiting or are poorly represented at medical school

The turn of the valve: representing with material models

Many scientific models are representations. Building on Goodman and Elgin’s notion of representation-as we analyse what this claim involves by providing a general definition of what makes something a scientific model, and formulating a novel account of how they represent. We call the result the DEKI account of representation, which offers a complex kind of representation involving an interplay of, denotation, exemplification, keying up of properties, and imputation. Throughout we focus on material models, and we illustrate our claims with the Phillips-Newlyn machine. In the conclusion we suggest that, mutatis mutandis, the DEKI account can be carried over to other kinds of models, notably fictional and mathematical models