Conformational analysis of oriented non-crystalline polymers using wide angle X-ray scattering

A procedure is presented for obtaining conformational parameters from oriented but non-crystalline polymers. This is achieved by comparison of the experimental wide angle X-ray scattering with that calculated from models but in such a way that foreknowledge of the orientation distribution function is not required. X-ray scattering intensity values for glassy isotactic poly(methylmethacrylate) are analysed by these techniques. The method could be usefully applied to other oriented molecular systems such as liquid crystalline materials.

Long-distance dispersal and its influence on adaptation to host resistance in a heterogeneous landscape

Small propagules like pollen or fungal spores may be dispersed by the wind over distances of hundreds or thousands of kilometres,even though the median dispersal may be only a few metres. Such long-distance dispersal is a stochastic event which may be exceptionally important in shaping a population. It has been found repeatedly in field studies that subpopulations of wind-dispersed fungal pathogens virulent on cultivars with newly introduced, effective resistance genes are dominated by one or very few genotypes. The role of propagule dispersal distributions with distinct behaviour at long distances in generating this characteristic population structure was studied by computer simulation of dispersal of clonal organisms in a heterogeneous environment with fields of unselective and selective hosts. Power-law distributions generated founder events in which new, virulent genotypes rapidly colonized fields of resistant crop varieties and subsequently dominated the pathogen population on both selective and unselective varieties, in agreement with data on rust and powdery mildew fungi. An exponential dispersal function, with extremely rare dispersal over long distances, resulted in slower colonization of resistant varieties by virulent pathogens or even no colonization if the distance between susceptible source and resistant target fields was sufficiently large. The founder events resulting from long-distance dispersal were highly stochastic and exact quantitative prediction of genotype frequencies will therefore always be difficult.

Televised Whorf: cognitive restructuring in advanced foreign language learners as a function of audio-visual media exposure

The encoding of goal-oriented motion events varies across different languages. Speakers of languages without grammatical aspect (e.g., Swedish) tend to mention motion endpoints when describing events, e.g., “two nuns walk to a house,”, and attach importance to event endpoints when matching scenes from memory. Speakers of aspect languages (e.g., English), on the other hand, are more prone to direct attention to the ongoingness of motion events, which is reflected both in their event descriptions, e.g., “two nuns are walking.”, and in their non-verbal similarity judgements. This study examines to what extent native speakers of Swedish (n = 82) with English as a foreign language (FL) restructure their categorisation of goal-oriented motion as a function of their English proficiency and experience with the English language (e.g., exposure, learning). Seventeen monolingual native English speakers from the United Kingdom (UK) were engaged for comparison purposes. Data on motion event cognition were collected through a memory-based triads matching task, in which a target scene with an intermediate degree of endpoint orientation was matched with two alternative scenes with low and high degrees of endpoint orientation, respectively. Results showed that the preference among the Swedish speakers of L2 English to base their similarity judgements on ongoingness rather than event endpoints was correlated with their use of English in their everyday lives, such that those who often watched television in English approximated the ongoingness preference of the English native speakers. These findings suggest that event cognition patterns may be restructured through the exposure to FL audio-visual media. The results thus add to the emerging picture that learning a new language entails learning new ways of observing and reasoning about reality.

Basement depths in the Parecis Basin (Amazon) with receiver functions from small local earthquakes in the Porto dos Gauchos seismic zone

Receiver functions from small local earthquakes were used to determine sediment thicknesses in Porto dos Gauchos seismic zone (PGSZ), Parecis basin, Amazonian craton, Brazil. The high velocity contrast between basement and sediments (P-wave velocities of 6.1 and 3.0 km/s, respectively) favors the generation of clear P-to-S converted phases (Ps) seen in the radial component, and also S-to-P conversions (Sp) seen in the vertical component. A reference 10 velocity model determined with shallow refraction experiment in PGSZ helped to convert Ps P time differences to basement depths at 15 stations deployed for aftershocks studies. The results of receiver function integrated with the shallow refraction reveal that the basement depths in the PGSZ increases from the basin border in the north up to about 600 m depth in the south. The basement topography, however, does not vary smoothly and a basement high with a steep topography was detected near the epicentral area. A 400 m elevation difference within 1.7 km distance suggests a possible border fault of a buried graben. This feature seems to be oriented roughly WSW-ENE and could indicate basement structures related to the seismicity of the Porto dos Gauchos Seismic Zone. (C) 2011 Elsevier Ltd. All rights reserved.

Percolation in a network with long-range connections: Implications for cytoskeletal structure and function

Cell shape, signaling, and integrity depend on cytoskeletal organization. In this study we describe the cytoskeleton as a simple network of filamentary proteins (links) anchored by complex protein structures (nodes). The structure of this network is regulated by a distance-dependent probability of link formation as P = p/d(s), where p regulates the network density and s controls how fast the probability for link formation decays with node distance (d). It was previously shown that the regulation of the link lengths is crucial for the mechanical behavior of the cells. Here we examined the ability of the two-dimensional network to percolate (i.e. to have end-to-end connectivity), and found that the percolation threshold depends strongly on s. The system undergoes a transition around s = 2. The percolation threshold of networks with s < 2 decreases with increasing system size L, while the percolation threshold for networks with s > 2 converges to a finite value. We speculate that s < 2 may represent a condition in which cells can accommodate deformation while still preserving their mechanical integrity. Additionally, we measured the length distribution of F-actin filaments from publicly available images of a variety of cell types. In agreement with model predictions, cells originating from more deformable tissues show longer F-actin cytoskeletal filaments. (C) 2008 Elsevier B.V. All rights reserved.

Discourse strategies and power roles in student-led distance learning

The assertion of identity and power via computer-mediated communication in the context of distance or web-based learning presents challenges to both teachers and students. When regular, face-to-face classroom interaction is replaced by online chat or group discussion forums, participants must avail themselves of new techniques and tactics for contributing to and furthering interaction, discussion, and learning. During student-only chat sessions, the absence of teacher-led, face-to-face classroom activities requires the students to assume leadership roles and responsibilities normally associated with the teacher. This situation raises the questions of who teaches and who learns; how students discursively negotiate power roles; and whether power emerges as a function of displayed expertise and knowledge or rather the use of authoritative language. This descriptive study represents an examination of a corpus of task-based discussion logs among Vietnamese students of distance learning courses in English linguistics. The data reveal recurring discourse strategies for 1) negotiating the progression of the discussion sessions, 2) asserting and questioning knowledge, and 3) assuming or delegating responsibility. Power is defined ad hoc as the ability to successfully perform these strategies. The data analysis contributes to a better understanding of how working methods and materials can be tailored to students in distance learning courses, and how such students can be empowered by being afforded opportunities and effectively encouraged to assert their knowledge and authority.

Distance teacher education – some experiences from Dalarna University, SwedenPaper presented at the 33rd Annual ATEE Conference Brussels, Belgium, 23rd – 27th August 2008

Distance teaching is now-a-days used in different shapes. However, it is something different from traditional campus organised education as it systematically uses Information Communication Technology (ICT) as a key element. When the distance teacher education started in Sweden many teacher educators doubted the wisdom of this. They expressed that the educational process to become a teacher would be deteriorated. For instance, they feared for high drop out rates and difficulties to examine in a proper way. The Swedish National Agency for Higher Education has recently edited a report that showed that this form of teacher education was well adapted to the labour market, but the possibilities for the teacher students to shape their education were relatively limited. However, we still know quite little about the effects of this way to educate teacher students. This paper explores the possibility of using distance teacher education.In a case study 20 students, who were the first to finish a complete a distance teacher education at Högskolan Dalarna, were asked in a questionnaire how they had apprehended their education. We also interviewed four of these students, as well as five teacher educators.One of our findings were that the distance teacher education reached new target groups, who not had been able to participate in university studies if it not had been offered in this form. Especially, this was valid for the middle-aged women, living a long distance away from a university, with social responsibilities for children or old parents. Other findings were that these students in general were target oriented and ambitious, wrote more than the campus students and developed that kind of skill better. Marratech, an ICT system for small groups, e-mail and chat were used for the communication. Marratech was considered to permit free and spontaneous communication, both of the teacher educators and the students. Initially the teacher educators were sceptical to distance teacher education, but afterwards they were surprised of how well it had worked. They declared that they had better and nearer contact with their students and more control over the students´ performance, but some parts of the teacher education were better suitable for campus education, for example, power of creating characters. Distance teacher education was considered time consuming and demanded much activity from the teacher educators as the students wanted rapid responses. This study indicates that distance teacher education works well for mature individuals with high motivation. However, it demands more time from the teacher educators, but it gives in general good results. Still, there are pedagogical challenges to overcome. Maybe we should reflect on a mix of distance teacher education and campus based teacher education, instead of separated ways of accomplishing teacher education?

Understanding the critical distance in sparse distributed memory

Modelos de tomada de decisão necessitam refletir os aspectos da psi- cologia humana. Com este objetivo, este trabalho é baseado na Sparse Distributed Memory (SDM), um modelo psicologicamente e neuro- cientificamente plausível da memória humana, publicado por Pentti Kanerva, em 1988. O modelo de Kanerva possui um ponto crítico: um item de memória aquém deste ponto é rapidamente encontrado, e items além do ponto crítico não o são. Kanerva calculou este ponto para um caso especial com um seleto conjunto de parâmetros (fixos). Neste trabalho estendemos o conhecimento deste ponto crítico, através de simulações computacionais, e analisamos o comportamento desta “Critical Distance” sob diferentes cenários: em diferentes dimensões; em diferentes números de items armazenados na memória; e em diferentes números de armazenamento do item. Também é derivada uma função que, quando minimizada, determina o valor da “Critical Distance” de acordo com o estado da memória. Um objetivo secundário do trabalho é apresentar a SDM de forma simples e intuitiva para que pesquisadores de outras áreas possam imaginar como ela pode ajudá-los a entender e a resolver seus problemas.

Análise textual dos discursos: responsabilidade enunciativa no texto jurídico

This investigation aims at describing, analyzing and interpreting the Commitment in Initial Petitions, which is a genre circumscribed in the judicial domain. For this purpose, we have chosen sections, facts as found and relevant law , sections of the petition, with the understanding that, in this way, respectively, the narration of events, which gives margin to the propositioning to the judicial action, and the exposition of the law that upholds the author s intention. We base our discussion on the field of Linguistics, more precisely, Textual Discourse Analysis (TDA), whose theoretical basis is derived from Textual Linguistics (TL) and Enunciative Linguistics. We foreground, particularly, the way in which the author of texts, objects of analysis, use discursive strategies that evidence ER. The relevance of this study, then, is in the formation of a critique of the judicial text, as it conceives of a dialogical approach to the point of view, raising not only questions about the way in which a linguistic instance conceives an object of discourse, but also considering questions of language inherent to technical writing and, in this aspect, contributing to the work of those operating in Law about the many ways ER is formed in the body of a petition. We selected two categories to analyze that, according to Adam (2011), characterize the degree of ER in the textual material of the propositional enunciations: the different types of representation of speech and the indications of profile of mediators. In this sense, with this task as an objective, we base our study regarding point of view on Rabatel (2003, 2009a, 2010) with relation to the enunciative approach, including the study of PDV in polyphonic and dialogical theoretical framework to study the ER from different types of speech representations that conceive forms of transmission of discourse and the role of the enunciating subject, mainly the responsibility and the prerogative by the propositional contents. In the same way, intending to study the indications of the mediator profiles, we observed the postulations of Guentchéva (1994, 1996), which develop the notion of mediative grammatical categories, of which permit the linguistic marking of distance and engagement of the enunciator with regard to the information expressed. The methodology we adopted was based on qualitative research, of an interpretive and introspective nature, in light of the fact that his study focuses on processes and strategies underlying language use. The corpus of the research is comprised of Initial Petitions, which gave rise to actions originating in the Civil Court of Currais Novos County RN. The data analysis shows that an object of discourse is always perspective oriented and presents the point of view of one or more enunciators. Consequently, the producer of a text, using the PDV of other enunciators, influences and establishes the argumentative orientation of the text. In the same way, it evidences the relevance of the use of mediated constructions in the judicial text, as they function as strategies attenuated to the responsibility of the producer of the text with what is said, and at the same time points to a discourse of authority through the entrance of the sources of law. Moreover, it reveals the documental and international importance of this practice, at the same time that it exposes the compositional and normative difficulties with regard to legal and linguistic aspects

In the eye of the storm: exploring the introduction of environmental issues in the production function in Brazilian companies

This article aims to analyse the introduction of environmental issues in the context of the production function, which has been referred to as the organisational area to lead corporate environmental management. With that purpose, the theoretical references for corporate environmental management and the necessary alterations in production function have been organised to include environmental aspects, especially in terms of product and process development, quality management, and logistics. Considering that this research field still lacks empirical evidence for Brazilian companies, four case studies were conducted using companies located in the country. The environmental management maturity level of those companies tends to follow the rate with which the environmental issue is introduced in production sub-areas, especially in the product development process. However, in most cases we found that the companies had difficulties in structuring the insertion of the environmental dimension in logistics. The final notes point out the distance observed between what is recommended by international literature and the reality of Brazilian companies in the challenge of making the production function environmentally friendly.

Relationship of upper-limb and thoracic muscle strength to 6-min walk distance in COPD patients

Study objectives: This study was developed to investigate the influence of thoracic and upperlimb muscle function on 6-min walk distance (6MWD) in patients with COPD.Design: A prospective, cross-sectional study.Setting: the pulmonary rehabilitation center of a university hospital.Patients: Thirty-eight patients with mild to very severe COPD were evaluated.Measurements and results: Pulmonary function and baseline dyspnea index (BDI) were assessed, handgrip strength, maximal inspiratory pressure (Pimax), and 6MWD were measured, and the one-repetition maximum (1RM) was determined for each of four exercises (bench press, lat pull down, leg extension, and leg press) performed on gymnasium equipment. Quality of life was assessed using the St. George Respiratory Questionnaire (SGRQ). We found statistically significant positive correlations between 6MWD and body weight (r = 0.32; p < 0.05), BDI (r = 0.50; p < 0.01), FEV, (r = 0.33; p < 0.05), PImax (r = 0.53; p < 0.01), and all values of 1RM. A statistically significant negative correlation was observed between 6MWD and dyspnea at the end of the 6-min walk test (r = -0.29; p < 0.05), as well as between 6MWD and the SGRQ activity domain (r = -0.45; p < 0.01) and impact domain (r = -0.34; p < 0.05) and total score (r = -0.40; p < 0.01). Multiple regression analysis selected body weight, BDI, Pimax, and lat pull down IRM as predictive factors for 6MWD (R-2 = 0.589).Conclusions: the results of this study showed the importance of the skeletal musculature of the thorax and upper limbs in submaximal exercise tolerance and could open new perspectives for training programs designed to improve functional activity in COPD patients.

Combined exercise training in asymptomatic elderly with controlled hypertension: Effects on functional capacity and cardiac diastolic function

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relationship between global structural parameters and Enzyme Commission hierarchy: Implications for function prediction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modifications in the correlation function in poly(vinyl alcohol)/silica hybrid wet gels

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Body size and flight distance in stingless bees (Hymenoptera: Meliponini): inference of flight range and possible ecological implications

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)