Applied environmental stresses to enhance the levels of polyphenolics in leaves of hawthorn plants

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72331/1/j.1399-3054.2004.00332.x.pd

The anisotropic Ashkin-Teller model: a renormalization group study

The two-dimensional ferromagnetic anisotropic Ashkin-Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distinct phases, recover all the known exacts results for the square lattice. The correlation length $(\nu_T)$ and crossover $(\phi)$ critical exponents are also calculated. With the only exception of the four-state Potts critical point, the entire phase diagram belongs to the Ising universality class.Comment: 3 ps figures, accepted for publication in Physica

The signed loop approach to the Ising model: foundations and critical point

The signed loop method is a beautiful way to rigorously study the two-dimensional Ising model with no external field. In this paper, we explore the foundations of the method, including details that have so far been neglected or overlooked in the literature. We demonstrate how the method can be applied to the Ising model on the square lattice to derive explicit formal expressions for the free energy density and two-point functions in terms of sums over loops, valid all the way up to the self-dual point. As a corollary, it follows that the self-dual point is critical both for the behaviour of the free energy density, and for the decay of the two-point functions.Comment: 38 pages, 7 figures, with an improved Introduction. The final publication is available at link.springer.co

History curriculum in the reform of Rio de Janeiro Municipal Department of Education

A proposta desse artigo é apresentar duas pesquisas que investigaram as mudanças realizadas no currículo de história da rede municipal do Rio de Janeiro, empreendidas pela gestão que atuou na Secretaria Municipal de Educação do Rio de Janeiro (SME/RJ) entre os anos de 2009 e 2013. Em busca da melhora da qualidade do ensino nas escolas, a SME/RJ iniciou uma reforma no currículo e no sistema de avaliação da rede, que incluiu a elaboração de Orientações curriculares e de Cadernos pedagógicos, no caso da disciplina escolar história. A primeira pesquisa foi realizada no contexto de produção dos Cadernos pedagógicos, a partir da atuação dos professores formuladores no trabalho de elaboração desse material. A segunda pesquisa investiga as modificações da política curricular realizadas por professores de história da rede que atuam no contexto da prática. O objetivo deste artigo é estabelecer um diálogo entre essas pesquisas, uma vez que ambas utilizaram como principal referencial teórico-metodológico, o ciclo de políticas (BOWE; BALL; GOLD, 1992). Considerando a complexidade das esferas da política, foi constatado que, ao circular pelos contextos estudados, a reforma curricular não foi simplesmente recebida e incorporada, mas modificada pelos sujeitos envolvidos, que produziram sentidos diferentes no texto original da política.This article presents two studies on the changes in the history curriculum of the municipal education system of Rio de Janeiro, which were undertaken by Rio de Janeiro Municipal Department of Education from 2009 to 2013. In an attempt to improve the quality of teaching, the Education Department launched a reform in the curriculum and the assessment system of municipal schools, which included the creation of Orientações curriculares (Curriculum guidelines) and Cadernos pedagógicos (Pedagogical notebooks) in the case of the history discipline. The first study was conducted in the context of the making of Cadernos pedagógicos and based on the work of teachers involved in it. The second study investigated the changes made in the curriculum policy by history teachers who work in classrooms in the municipal system. The goal of this article is to establish a dialogue between the studies, since both used the cycle of policies (BOWE; BALL; GOLD, 1992) as their main theoretical-methodological framework. Considering the complexity of the spheres of the policy, we found that, as the curriculum reform circulated in the contexts studied, it was not simply received and incorporated, but modified by the subjects involved, who produced meanings which differ from the original text of the policy

Inhomogeneity-induced second-order phase transitions in Potts model on hierarchical lattices

The thermodynamics of the $q$-state Potts model with arbitrary $q$ on a class of hierarchical lattices is considered. Contrary to the case of the crystal lattices, it has always the second-order phase transitions. The analytical expressions fo the critical indexes are obtained, their dependencies on the structural lattice pararmeters are studied and the scailing relations among them are establised. The structural criterion of the inhomogeneity-induced transformation of the transition order is suggested. The application of the results to a description of critical phenomena in the dilute crystals and substances confined in porous media is discussed.Comment: 9 pages, 2 figure

Photodissociation and the Morphology of HI in Galaxies

Young massive stars produce Far-UV photons which dissociate the molecular gas on the surfaces of their parent molecular clouds. Of the many dissociation products which result from this ``back-reaction'', atomic hydrogen \HI is one of the easiest to observe through its radio 21-cm hyperfine line emission. In this paper I first review the physics of this process and describe a simplified model which has been developed to permit an approximate computation of the column density of photodissociated \HI which appears on the surfaces of molecular clouds. I then review several features of the \HI morphology of galaxies on a variety of length scales and describe how photodissociation might account for some of these observations. Finally, I discuss several consequences which follow if this view of the origin of HI in galaxies continues to be successful.Comment: 18 pages, 7 figures in 8 files, invited review paper for the conference "Penetrating Bars Through Masks of Cosmic Dust: The Hubble Tuning Fork Strikes a New Note", South Africa, June 2004. Proceedings to be published by Kluwer, eds. D.L. Block, K.C. Freeman, I. Puerari, R. Groess, & E.K. Bloc

OLDER STUDENTS’ DEVELOPMENT OF FOREIGN LANGUAGE AND DIGITAL LITERACY THROUGH ONLINE TASKS

We are surrounded by technology in almost every activity we perform daily and especially for the elderly there is a growing need to learn how to use computers in a way that makes them feel more integrated into the digital age. Besides, knowing English as a foreign language (FL) is a skill that is essential, especially when using technological devices. Therefore, this article investigates how teaching mediated by technology can be helpful for older learners’ language development. Since there are few studies in this area (OHLY, 2007; SCHLEPPEGRELL, 1987), the aim of this article is to analyse and provide guidelines for the creation of online language tasks focused on the development of digital literacy and the improvement of FL learning of older students. This study discusses task design based on learning strategies and principles of computer literacy. Data gathered from online tasks built to improve the FL learning of an older student will illustrate the discussion triggered by this research. Finally, the paper will present some instances of use of the online material and opportunities for development of the student’s knowledge through interaction with the teacher and with online English speaking peers, using online tools such as blogs, forums and software of synchronous communication

The Cost of Simplifying Air Travel When Modeling Disease Spread

BACKGROUND: Air travel plays a key role in the spread of many pathogens. Modeling the long distance spread of infectious disease in these cases requires an air travel model. Highly detailed air transportation models can be over determined and computationally problematic. We compared the predictions of a simplified air transport model with those of a model of all routes and assessed the impact of differences on models of infectious disease. METHODOLOGY/PRINCIPAL FINDINGS: Using U.S. ticket data from 2007, we compared a simplified "pipe" model, in which individuals flow in and out of the air transport system based on the number of arrivals and departures from a given airport, to a fully saturated model where all routes are modeled individually. We also compared the pipe model to a "gravity" model where the probability of travel is scaled by physical distance; the gravity model did not differ significantly from the pipe model. The pipe model roughly approximated actual air travel, but tended to overestimate the number of trips between small airports and underestimate travel between major east and west coast airports. For most routes, the maximum number of false (or missed) introductions of disease is small (<1 per day) but for a few routes this rate is greatly underestimated by the pipe model. CONCLUSIONS/SIGNIFICANCE: If our interest is in large scale regional and national effects of disease, the simplified pipe model may be adequate. If we are interested in specific effects of interventions on particular air routes or the time for the disease to reach a particular location, a more complex point-to-point model will be more accurate. For many problems a hybrid model that independently models some frequently traveled routes may be the best choice. Regardless of the model used, the effect of simplifications and sensitivity to errors in parameter estimation should be analyzed

Assessing framing of uncertainties in water management practice

Dealing with uncertainties in water management is an important issue and is one which will only increase in light of global changes, particularly climate change. So far, uncertainties in water management have mostly been assessed from a scientific point of view, and in quantitative terms. In this paper, we focus on the perspectives from water management practice, adopting a qualitative approach. We consider it important to know how uncertainties are framed in water management practice in order to develop practice relevant strategies for dealing with uncertainties. Framing refers to how people make sense of the world. With the aim of identifying what are important parameters for the framing of uncertainties in water management practice, in this paper we analyze uncertainty situations described by decision-makers in water management. The analysis builds on a series of ¿Uncertainty Dialogues¿ carried out within the NeWater project with water managers in the Rhine, Elbe and Guadiana basins in 2006. During these dialogues, representatives of these river basins were asked what uncertainties they encountered in their professional work life and how they confronted them. Analysing these dialogues we identified several important parameters of how uncertainties get framed. Our assumption is that making framing of uncertainty explicit for water managers will allow for better dealing with the respective uncertainty situations. Keywords Framing - Uncertainty - Water management practic