Efeitos de acoplamentos biquadráticos e campos aleatórios em vidros de spins

In this work we have studied the effects of random biquadratic and random fields in spin-glass models using the replica method. The effect of a random biquadratic coupling was studied in two spin-1 spin-glass models: in one case the interactions occur between pairs of spins, whereas in the second one the interactions occur between p spins and the limit p > oo is considered. Both couplings (spin glass and biquadratic) have zero-mean Gaussian probability distributions. In the first model, the replica-symmetric assumption reveals that the system presents two pha¬ses, namely, paramagnetic and spin-glass, separated by a continuous transition line. The stability analysis of the replica-symmetric solution yields, besides the usual instability associated with the spin-glass ordering, a new phase due to the random biquadratic cou¬plings between the spins. For the case p oo, the replica-symmetric assumption yields again only two phases, namely, paramagnetic and quadrupolar. In both these phases the spin-glass parameter is zero. Besides, it is shown that they are stable under the Almeida-Thouless stability analysis. One of them presents negative entropy at low temperatures. We developed one step of replica simmetry breaking and noticed that a new phase, the biquadratic glass phase, emerge. In this way we have obtained the correct phase diagram, with.three first-order transition lines. These lines merges in a common triple point. The effects of random fields were studied in the Sherrington-Kirkpatrick model consi¬dered in the presence of an external random magnetic field following a trimodal distribu¬tion {P{hi) = p+S(hi - h0) +Po${hi) +pS(hi + h0))- It is shown that the border of the ferromagnetic phase may present, for conveniently chosen values of p0 and hQ, first-order phase transitions, as well as tricritical points at finite temperatures. It is verified that the first-order phase transitions are directly related to the dilution in the fields: the extensions of these transitions are reduced for increasing values of po- In fact, the threshold value pg, above which all phase transitions are continuous, is calculated analytically. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified

Estudo das propriedades críticas do processo epidêmico por par com difusão de pares

The pair contact process - PCP is a nonequilibrium stochastic model which, like the basic contact process - CP, exhibits a phase transition to an absorbing state. While the absorbing state CP corresponds to a unique configuration (empty lattice), the PCP process infinitely many. Numerical and theoretical studies, nevertheless, indicate that the PCP belongs to the same universality class as the CP (direct percolation class), but with anomalies in the critical spreading dynamics. An infinite number of absorbing configurations arise in the PCP because all process (creation and annihilation) require a nearest-neighbor pair of particles. The diffusive pair contact process - PCPD) was proposed by Grassberger in 1982. But the interest in the problem follows its rediscovery by the Langevin description. On the basis of numerical results and renormalization group arguments, Carlon, Henkel and Schollwöck (2001), suggested that certain critical exponents in the PCPD had values similar to those of the party-conserving - PC class. On the other hand, Hinrichsen (2001), reported simulation results inconsistent with the PC class, and proposed that the PCPD belongs to a new universality class. The controversy regarding the universality of the PCPD remains unresolved. In the PCPD, a nearest-neighbor pair of particles is necessary for the process of creation and annihilation, but the particles to diffuse individually. In this work we study the PCPD with diffusion of pair, in which isolated particles cannot move; a nearest-neighbor pair diffuses as a unit. Using quasistationary simulation, we determined with good precision the critical point and critical exponents for three values of the diffusive probability: D=0.5 and D=0.1. For D=0.5: PC=0.89007(3), β/v=0.252(9), z=1.573(1), =1.10(2), m=1.1758(24). For D=0.1: PC=0.9172(1), β/v=0.252(9), z=1.579(11), =1.11(4), m=1.173(4)

A perda de grupos funcionais em comunidades virtuais: efeito das interações entre espécies e grupos funcionais

High levels of local, regional, and global extinctions has progressively simplified communities in terms of both species and ecosystem functioning. Theoretical models demonstrated that the degree of functional redundancy determines the rates of functional group loss in response to species extinctions. Here, we improve the theoretical predictions by incorporating in the model interactions between species and between functional groups. In this study, we tested the effect of different scenarios of interspecific interactions and effects between functional groups on the resistance to loss of community functional groups. Virtual communities have been built with different distribution patterns of species in functional groups, both with high and low evenness. A matrix A was created to represent the net effect of interspecific interactions among all species, representing nesting patterns, modularity, sensitive species, and dominant species. Moreover, a second matrix B was created to represent the interactions between functional groups, also exhibiting different patterns. The extinction probability of each species was calculated based on community species richness and by the intensity of the interspecific interactions that act upon it and group to which it belongs. In the model, successive extinctions decrease the community species richness, the degree of functional redundancy and, consequently, the number of functional groups that remain in the system. For each scenario of functional redundancy, A, and B, we ran 1000 simulations to generate an average functional extinction curve. Different model assumptions were able to generate remarkable variation on functional extinction curves. More extreme variations occurred when the matrix A and B caused a higher heterogeneity in the species extinction probability. Scenarios with sensitive species, positive or negative, showed a greater variation than the scenarios with dominant species. Nested interactions showed greater variation than scenarios where the interactions were in modules. Communities with maximal functional evenness can only be destabilized by the interactions between species and functional groups. In contrast, communities with low functional evenness can have its resistance either increased or decreased by the interactions. The concentration of positive interactions in low redundancy groups or negative interactions in high redundancy groups was able to decrease the functional extinction rates. In contrast, the concentration of negative interactions in low redundancy groups or positive interactions in high redundancy groups was able to increase the functional extinction rates. This model shows results that are relevant for species priorization in ecosystem conservation and restoration

O papel de interações positivas entre plantas na regeneração de áreas degradadas na caatinga

Conselho Nacional de Desenvolvimento Científico e Tecnológico

O lugar pedagógico da educação física na educação infantil: saberes (re)construídos na formação continuada do PAIDÉIA/UFRN

The present study aimed to investigate the overview of teachers in continuing education program who work in kindergarten, about the continuing education developed by the Paideia/UFRN through the Course of Specialization in Art Teaching and Physical Education in Childhood, having as key focus, the knowing / doing related to physical education in Childhood. From this general goal, it was elected some specific objectives as: to know the interests and expectations that motivated the teachers to participate of that referred training; the evaluation by teachers on regard of the continuing education proposed: boosters factors for possible changes in teaching activities regarding the practice of teaching physical education in kindergarten. The methodology took the principles and techniques of qualitative research strategy and the characteristics of descriptive and interpretive strategy. The locus of this research was the Course of Specialization in Art Education and Physical Education in childhood, having as the citizens of this research twenty three teachers taking that specialization course. For building and systematization of the data, we used the following tools and procedures: a questionnaire, a semi structured interview and documents analysis. The data was constructed based on the technique of content analysis, focusing the reflections and speech of the teachers about the creation of new meanings and senses for the knowing / doing in Physical Education. It was found, among other results, the need and quest for improvement of teacher education, in order to improve educational practice. It was also evident that the situations of dialogues (interactions with peers, with their professors and other professionals in the related area or not) were mentioned by most teachers in the course as a relevant moment of redefinition of knowledge. In relation to Physical Education, it was found that participation in the course of specialization provided the recognition of teaching practice of physical education as part of the curriculum and the importance of inclusion of its specificities in their educational planning. From these elaborations, we come to the conclusion that knowing the perspectives of the teachers about continuing education can contribute to the theoretical and methodological discussions in teachers education and the creation of new actions - projects and programs of continuing education constructing increasingly ways towards a successful teacher formation, able to provide new forms of acting in the educational context

O papel das interações no processo de inclusão de crianças com síndrome de Down

La inclusión actual está siendo orientada por diversos principios, tales como la cooperación, aceptación de las diferencias individuales, valoración de cada individuo y convivencia dentro de la diversidad. En esta perspectiva, se entiende la educación como un proceso, en que todos los alumnos con necesidades educativas especiales tienen el derecho de escolarización en el salón de clase general, visando el desarrollo máximo de su potencial. Es en la interacción con los otros que los niños desarrollan efectivamente sus capacidades, aprenden a descubrir al otro como portador de valores y, como consecuencia de esa relación, a tener más confianza en sí mismo. Es por lo tanto necesario que las influencias educativas sean recíprocas y que en la convivencia escolar, puedan ser constantes las relaciones interpersonales. Así, haciendo con que cada niño sea introducido a la vivencia de la ciudadanía, al aprendizaje que va más allá de los contenidos escolares y envolviendo también la construcción de valores, hábitos y actitudes. Con base en estos aspectos, nuestro trabajo tuvo como objetivo la interacción entre niños con síndrome de Down y sus compañeros, en dos clases regulares de una escuela pública em el nível de educación infantil, en la ciudad de Natal/RN. En este sentido, realizamos un estudio de caso con dos niños, envolviendo observación, aplicación de entrevistas y cuestionarios, además de la utilización de la sociometría. Los datos analizados apuntan la existencia de un espíritu de cooperación entre los niños, del respeto a la diversidad y también a sus limitaciones. Estos son valores que están siendo construidos y que son percibidos claramente en lo cotidiano de la escuela. De igual modo, de esta convivência resulta la construcción de vínculos afectivos y sociales entre los niños que presentan el síndrome de Down y sus compañeros, siendo estos similares a los desarrollados entre los niños en general. Sin embargo, se evidencia todavía, la necesidad de un incentivo mayor por parte de la comunidad escolar para que sean establecidos vínculos más significativos

Interações comunicativas entre uma professora e um aluno com transtorno invasivo do desenvolvimento na escola regular

Inclusion of students with autism in regular education settings is a topic that has not been much explored by the national scientific literature. This matter is complex and, due to the extent of various aspects involved, it is essential to delimitate a focus of investigation. The direction taken by this study was to evaluate the effects of an intervention program in the communicative interactions between a student with autism and his teacher in a regular classroom. Data were collected in an elementary private school, located in the city of Natal, Rio Grande do Norte during the 2010 academic school year. The study included a teacher and a non-vocal, 10-year-old student diagnosed with autism. A quasi-experimental A-B research design was employed. During the intervention program the teacher was trained to use Naturalistic Teaching Strategies and Alternative and Augmentative Communication (AAC) resources to increase the frequency of interactions with the student during three classroom routines (entry time, snack and pedagogical activity). The results indicated qualitative and quantitative changes in the interactions of the dyad after the implementation of the intervention program. The student began to use pictograms to communicate with the teacher in two of the three routines investigated. The frequency of AAC use was also observed in the teacher‟s repertoire, especially when the student failed to understand gestures and words. The teacher positively evaluated the intervention program

A dimensão social do desenho: um estudo sobre as interações no processo de (re) construção imagética da criança no Ensino Fundamental

In the historical-cultural perspective, the drawing is processed by means of a shared and complex way, under diverse relations with the other and with the immersed signs of the culture. That is, something constituted by the social interactions and that can modify the structure of the psychological functions, therefore as socialized sign, propitiates the incorporation of the functions socially. In this way, the figuration carrier sensitive and established meanings historically disclosing the shared experiences and the ways of the subject to think and perceive the world. Such reflections gave shape to the main problem of this research: how to think over about the drawing at the school to incide in the reconstruction of the childs imaginative language? Under such perspective, this work deals with the interactions in the production process of the drawing of the children in a context of teach-Iearning of the elementary school having as goal to analyze the interactions established in the cIassroom in the process of production of the drawings; to propose situations of learnings that favor the advance graphical expression of the students; and to identify in the interactive games some relations between body expression and drawing. For its accomplishment, it was opted for the construction process based in the collaborative investigation by the fact to propitiate negotiations, sharing and confrontation of ideas, becoming possible a joint construction of the knowledge. For this research, the researcher and the collaborating teacher, as well as the involved children, become themselves into co-authors of the context studied. As locus of the research, it was chosen a first cycle class, with 30 students, from Municipal School Profª. Emília Ramos (Natal/RN - Brazil), whose election took in account the fact of this school to constitute in a promotional space of reflections and professional development of teachers in service and, at the same time, for presentinglimitations theoretic- methodological in the field of teaching for Arts. In the process of the research, it was perceived that the children with the support of the verbal language formulates meanings on the seen and imagined object, printing lines and forms that if overlap to the physiological aspects of the visual perception. That is, the drawing discloses a reality appraised, enriched for the picked up vision of the image, but the meanings established for the author, or observer who becomes it perceivable and identified. In the systemizing situations, it was observed that the teaching-Iearning process of the drawing, implies a co-construction between teachers and learners. And, moreover, the necessity to interlace emotion and cognition by means of plastic-corporal interactions that foment drawing experiences, whose process concurs for the imagenative reconstruct of the apprentices

Estudo das interações polifenol-proteína e das reações de escurecimento não-enzimático para o processamento de cajuína

The cashew, a fruit from Brazilian Northeast is used to produce juice due to its flavor and vitamin C richness. However, its acceptance is limited due to its astringency. Cajuína is a derivate product appreciated by its characteristic flavor, freshness and lack of astringency, due to tannin removal. Cajuína is a light yellow beverage made from clarified cashew juice and sterilized after bottling. It differs from the integral and concentrated juice by the clarification and thermal treatment steps. Many problems such as haze and excessive browning could appear if these steps are not controlled. The objective of this work was divided into two stages with the aim to supply process information in order to obtain a good quality product with uniform characteristics (sensory and nutritional). Polyphenol-protein interaction was studied at the clarification step, which is an empirical process, to provide values on the amount of clarifying solution (gelatin) that must be added to achieve a complete juice clarification. Clarification essays were performed with juice dilutions of 1:2 and 1:10 and the effect of metabissulfite and tannic acid addition was evaluated. It was not possible to establish a clarification point. Metabissulfite did not influenced the clarification process however tannic acid addition displaced the clarification point, showing the difficulty visual monitoring of the process. Thermal treatment of clarified juice was studied at 88, 100, 111 e 121 °C. To evaluate the non-enzymatic browning, vitamin C, 5-hidroximetilfurfural (5-HMF) and sugar variation were correlated with color parameters (reflectance spectra, color difference and CIELAB). Kinetic models were obtained for reflectance spectra, ascorbic acid and 5-HMF. It was observed that 5-HMF introduction followed a first order kinetic rate at the beginning of the thermal treatment and a zero order kinetic at later process stages. An inverse correlation was observed between absorbance at 420 nm and ascorbic acid degradation, which indicates that ascorbic acid might be the principal factor on cajuína non-enzymatic browning. Constant sugar concentration showed that this parameter did not contribute directly to the nonenzymatic browning. Optimization techniques showed showed that to obtain a high vitamin C and a low 5-HMF content, the process must be done at 120 ºC. With the water-bath thermal treatment, the 90 °C temperature promoted a lower ascorbic acid degradation at the expense of a higher 5-HMF level

A leitura e o leitor presumido nas avaliações oficiais

Este estudio se refiere a una investigación a cerca de la concepción de la lectura que subyace en la Matriz de Referencia de la Prueba Brasil, y, mediante las análisis del modelo 2009, entender lo que el lector se supone que responder en las preguntas de esta prueba. El estudio tiene como objetivo satisfacer se presume lector general para responder a las preguntas de prueba de Brasil y el mapa de la concepción de la lectura que subyace en la matriz de referencia tal prueba. Los objetivos específicos apuntan a examinar los temas de Prueba Brasil, identificando qué descriptores se materializan en el mismo, que son los más recurrentes. El estudio tiene como fundamentos los estudios bakhtinianos a cerca de los diálogos del linguaje (Bakhtin, 2003, 2008; Volochínov/Bakhtin, 1993) y la concepción de la lectura defendida por Geraldi (2007), Larossa (2001) y DeCerteau (1994). La investigación és caracterizada como cualitativo-interpretativo, con enfoque socio-histórico, y se encuentra dentro del campo de la Lingüística Aplicada, que en las últimas décadas ha demostrado contribuciones para la enseñanza de lenguas y formación docente. Para hacer el análisis de las pruebas, inicialmente construido una tabla (Tabla 1), que contiene los seis macrotópicos Matrix lengua portuguesa en la que estábamos repartiendo los descriptores presentes en las cuestiones de prueba referenciada relacionándolos con sus temas. Tras analizar la cuestión, con el fin de identificar al presunto lector a responder a estas preguntas. Mediante análisis de la Matriz de Referencia de la Prueba Brasil, entendemos que ella está de acuerdo con los Parámetros Curriculares de la Lengua Portuguesa. Así, la concepción que subyace en la lectura es que la lectura es una actividad que depende del proceso individual, pero que és parte de un contexto social e involucra a habilidades relacionadas con la comprensión y producción de sentido. Mediante la observación de la prueba, afirmamos qué el lector con la capacidad de responder a las preguntas es lo que desarrolla actitudes favorables a cerda de la lectura. A saber: (i) reconocen ampliamente las palabras, (ii) identifican los objetivos y funciones de la lectura, en reconocimiento de la función de apoyo de género y el contexto del texto, (iii) predice el contenido de los textos a se lee a la luz de su apoyo, su género y su contexto; (iv) plantea hipótesis sobre el contenido del texto que se lee, (v) es capaz de buscar ideas textual e intertextual. Es decir, hace inferencias, aumentando la comprensión, la asociación de diversos elementos presentes en el texto y que son parte de sus propias experiências personales, (vi) construye la comprensión global del texto leído por la unificación de la información explícita e implícita, (vii) tiene la capacidad de evaluar la lectura de forma ética y afectiva, o de hacer extrapolaciones coerentes sin escapar de la temática del texto. Por último, podemos decir que las implicaciones pedagógicas de este trabajo para mi actividad profesional es de gran importancia, ya que desde la detección de lo que se requiere de los estudiantes y, en consecuencia, un nuevo enfoque para la enseñanza de la lengua materna como podemos reflexionar sobre eso y encontrar maneras de mejorar nuestro desempeño. Tanto nuestro entrenador como nuestros compañeros. Dejando a un nivel puramente descriptivo de los problemas de acción conjunta más eficaz, entendiendo que la enseñanza de lectura tiene un carácter complejo. En este sentido, tenemos que ser menos intuitivo y más reflexiva. Nos gustaría hacer hincapié en que tenemos la intención de socializar esta investigación con nuestros compañeros, ya que entendemos que es un material que puede contribuir a un nuevo aprendizaje para la práctica de los profesores que se inclinan. Además indicó que la principal contribución de este trabajo es nuestra mirada en el proceso de la lectura en el aula, la comprensión de que el estudiante de ofertas diarias con textos localizados, derechos de autor, histórico y representativo de las diferentes interacciones en el mundo. Por lo tanto, es el momento de ser gestado las prácticas de lectura hacia una educación más significativa

Do hip hop ao ciberespaço: interações midiáticas em jovens da periferia

En el barrio de Guarapes, al oeste de Natal, RN, un grupo de jóvenes se organizó para buscar de paz en su vecindario. Encontraron en la cultura hip hop una forma de contar sus historias y trabajar en el fortalecimiento de su propio lugar. Formaron la Posse de Hip Hop Lelo Melodia (PH2LM) y hace cerca de dos años, instalaron la "Bodega Digital", una especie de telecentro que ofrecía acceso a computadoras e Internet, donde pudieron producir una gran cantidad de música, además del primer video del grupo musical, que está en el aire a través de la Internet. En un suburbio, los procesos de mediatización de la sociedad pueden adquirir su propia dinámica y seguir movimientos que van más allá de las barreras impuestas por el proceso contradictorio de la globalización. En esta investigación, se buscó establecer relaciones entre la acción político-cultural de los jóvenes de la Posse y su participación en los medios de comunicación, especialmente en la Internet. Al observar al grupo y en entrevistas episódicas con sus miembros, trazamos un mapa e interpretamos los movimientos de los jóvenes hacia el ciberespacio y en sentido inverso, cómo traen a la calle lo que conquistan allí. Hemos encontrado que, a pesar de todos los obstáculos, estos jóvenes encuentran vacíos y los aprovechan para asegurar su acceso a los medios de comunicación y su participación en el ciberespacio.

Estudo de sistemas complexos com interações de longo alcance : percolação, redes e tráfego

In this thesis we investigate physical problems which present a high degree of complexity using tools and models of Statistical Mechanics. We give a special attention to systems with long-range interactions, such as one-dimensional long-range bondpercolation, complex networks without metric and vehicular traffic. The flux in linear chain (percolation) with bond between first neighbor only happens if pc = 1, but when we consider long-range interactions , the situation is completely different, i.e., the transitions between the percolating phase and non-percolating phase happens for pc < 1. This kind of transition happens even when the system is diluted ( dilution of sites ). Some of these effects are investigated in this work, for example, the extensivity of the system, the relation between critical properties and the dilution, etc. In particular we show that the dilution does not change the universality of the system. In another work, we analyze the implications of using a power law quality distribution for vertices in the growth dynamics of a network studied by Bianconi and Barabási. It incorporates in the preferential attachment the different ability (fitness) of the nodes to compete for links. Finally, we study the vehicular traffic on road networks when it is submitted to an increasing flux of cars. In this way, we develop two models which enable the analysis of the total flux on each road as well as the flux leaving the system and the behavior of the total number of congested roads

Vidros de spins de Ashkin-Teller com interações entre p-spins

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Influência da filogenia em redes de interações ecológicas

In this thesis we deal with a class of composed networks that are formed by two tree networks, TP and TA, whose end points touches each other through a bipartite network BPA. We explore this network using a functional approach. We are interested in what extend the topology, or the structure, of TX (X = A or P) determines the links of BPA. This composed structure is an useful model in evolutionary biology, where TP and TA are the phylogenetic trees of plants and animals that interact in an ecological community. We use in this thesis two cases of mutualist interactions: frugivory and pollinator networks. We analyse how the phylogeny of TX determines or is correlated with BPA using a Monte Carlo approach. We use the phylogenetic distance among elements that interact with a given species to construct an index κ that quantifies the influence of TX over BPA. The algorithm is based in the assumption that interaction matrices that follows a phylogeny of TX have a total phylogenetic distance smaller than the average distance of an ensemble of Monte Carlo realizations generated by an adequate shuffling data. We find that the phylogeny of animals species has an effect on the ecological matrix that is more marked than plant phylogeny

Interações físicas e psicossociais em mulheres com fibromialgia

Fibromyalgia (FM) is a non-inflammatory rheumatic syndrome of unknown etiology, with symptoms of diffuse musculoskeletal pain and presence of specific anatomic sites called tender points. The symptoms are often associated with fatigue, sleep disturbances, morning stiffness, alterations in pain perception, anxiety and depression. Fibromyalgia exhibits a correlation between physical and behavioral symptoms, which have a negative influence on the quality of life of patients. Emotional skills are important factors since they are related to subjective well-being, personal productivity, social interaction and interpersonal relationships. We aim to describe the physical and psychosocial interactions in women with FM, showing the association between perceived social support and affect with symptoms of pain, functionality and mood. We will also describe a body representation of pain in women with FM. Data were collected over 3 years and the sample size ranged between studies. This is an exploratory cross-sectional study conducted with a convenience sample of 63 women with FM and 42 healthy women as a control group (CT), aged 20-76 years, recruited through spontaneous demand at Onofre Lopes University Hospital (HUOL) and the Clinical School of Physiotherapy of Universidade Potiguar (UNP). The Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory (BDI), Social Support Scale (MOS), Hamilton Anxiety Scale and Scale of Positive and Negative Affect Schedule (PANAS), in addition to pressure algometry were used. For data analysis, we used parametric and non-parametric tests and a general linear model with adjustment variables and analysis of variance. A significant difference was found between pain threshold and tolerance, functionality, depression, anxiety, social support, and positive and negative affect between the groups. Affective states and social support were associated with anxiety, depression and functionality. A body was drawn representing pain with higher incidences in trapeze, supraspinatus and second ribs. The reason for studying sensory aspects, affective behavior and social support in FM patients opens perspectives for scientific and clinical research of this syndrome. Women with chronic pain such as FM appear to have altered mood states, less social support and affective dysfunctions, influencing the other symptoms of the syndrome