Coherent regimes of globally coupled dynamical systems

The paper presents a method by which the mean field dynamics of a population of dynamical systems with parameter diversity and global coupling can be described in terms of a few macroscopic degrees of freedom. The method applies to populations of any size and functional form in the region of coherence. It requires linear variation or a narrow distribution for the dispersed parameter. Although being an approximation, the method allows us to quantitatively study the collective regimes that arise as a result of diversity and coupling and to interpret the transitions among these regimes as bifurcations of the effective macroscopic degrees of freedom. To illustrate, the phenomenon of oscillator death and the route to full locking are examined for chaotic oscillators with time scale mismatch.Comment: 5 pages, 3 figure

Noise-induced macroscopic bifurcations in globally-coupled chaotic units

Large populations of globally-coupled identical maps subjected to independent additive noise are shown to undergo qualitative changes as the features of the stochastic process are varied. We show that for strong coupling, the collective dynamics can be described in terms of a few effective macroscopic degrees of freedom, whose deterministic equations of motion are systematically derived through an order parameter expansion.Comment: Phys. Rev. Lett., accepte

Heterogeneous individual motility biases group composition in a model of aggregating cells

Aggregative life cycles are characterized by alternating phases of unicellular growth and multicellular development. Their multiple, independent evolutionary emergence suggests that they may have coopted pervasive properties of single-celled ancestors. Primitive multicellular aggregates, where coordination mechanisms were less efficient than in extant aggregative microbes, must have faced high levels of conflict between different co-aggregating populations. Such conflicts within a multicellular body manifest in the differential reproductive output of cells of different types. Here, we study how heterogeneity in cell motility affects the aggregation process and creates a mismatch between the composition of the population and that of self-organized groups of active adhesive particles. We model cells as self-propelled particles and describe aggregation in a plane starting from a dispersed configuration. Inspired by the life cycle of aggregative model organisms such as Dictyostelium discoideum or Myxococcus xanthus, whose cells interact for a fixed duration before the onset of chimeric multicellular development, we study finite-time configurations for identical particles and in binary mixes. We show that co-aggregation results in three different types of frequency-dependent biases, one of which is associated to evolutionarily stable coexistence of particles with different motility. We propose a heuristic explanation of such observations, based on the competition between delayed aggregation of slower particles and detachment of faster particles. Unexpectedly, despite the complexity and non-linearity of the system, biases can be largely predicted from the behavior of the two corresponding homogenous populations. This model points to differential motility as a possibly important factor in driving the evolutionary emergence of facultatively multicellular life-cycles

Ampelographic characteristics of the grape variety Malbec, cultivated in Mendoza (Argentina) : according to the O.I.V. method

De acuerdo con el programa Caracterización ampelográfica, fenológica y bioclimática de cepajes se ha actualizado la descripción de la variedad Malbec según normas homologadas internacionalmente. El método utilizado se ha basado en los Códigos de Caracteres Ampelográficos de la O.I.V., que abarcan: detallada observación de los órganos de la planta • sinónimos • origen, antecedentes y situación actual, • características ampelográficas y diferenciales • comportamiento agronómico y fenológico, • aptitud Los resultados conforman una ficha actualizada del cepaje, complementada con tomas fotográficas de brote, hoja, racimo, flor, baya y semilla.The grape variety Malbec description is part of the Ampelographic, phenologic and bioclimate characterization program. This work is an up-date of the descriptions existing actually according to present rules and internationally homologated standards. The description is based on methodology supply by O.I.V. on t detailed observation of the differents plant organs, synonymous, origin, antecedents, actual situation, ampelo-graphic and differential characteristics, agronomic and phenologic behavior, and aptitude. List of characters of grape varieties up to-date and completed with photograps of the shoot, leaf, bunch, flower, grain and seed.Fil: Rodríguez, José G. . Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Matus, Mirta Susana. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Catania, Carlos D.. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción AgropecuariaFil: Avagnina de Del Monte, Silvia . Universidad Nacional de Cuyo. Facultad de Ciencias Agraria

Experimental left pneumonectomy in pigs. Procedure and management

Background Because there is no detailed description of procedures and perioperative management of major pulmonary resections in swine, we reviewed our experience to delineate the most effective practice in performing left pneumonectomy. Materials and methods Analysis of 11 consecutive left pneumonectomies. Animal data, operative reports, anesthesia records, and perioperative facts were evaluated. Follow-up information until postoperative day 60, methods of care-taking, therapy administration, and all the stabling aspects were systematically assessed. The investigation was aimed at highlighting those procedural steps or details which make the difference in optimizing the available resources (animals, instruments, and personnel). No statistical analysis was performed considering data characteristics and the descriptive nature of information. Results Surgery requires a median time of 2 h and 16 min; two operators and one anesthesiologist represent the basic team. Circulators' number depends on goals to accomplish. The most straightforward procedure requires careful dissection of the pulmonary ligament (limited view), pulmonary veins (low variability), pulmonary artery (delicate), and finally bronchus (no variability observed). The key factors for good anesthesia management have been identified: sedation by caregivers, preoxygenation before induction of general anesthesia, high respiratory rates with low tidal volume after pneumonectomy, and noninvasive ventilation after extubation. Antibiotic prophylaxis has been performed. Postoperative care must be continuous until animals are able to stand up, afterward "preventive noncurative," and always animal friendly. Ideas for minimally stressful therapy administration are helpful. Conclusions After the delineation of this methodology, the compliance to a routine practice allowed us to reduce time, stress, and cost; quality and quantity of possible research increased

A UTILIZAÇÃO DA TECNOLOGIA COMPUTACIONAL NO PROCESSO DE LEITURA E ESCRITA

: In recent years, it is observed that pupils of educations basic and average present difficulties in the reading and the writing. Ahead of this, with the present research, one searchs to contribute for the improvement of the reading and the writing with the use of the computer. The object is the process of learning of 12 pupils of 5ª series of basic education, with ages between 11 and 13 years, with deficiency in the reading and writing. The objective of the inquiry mentions to it the advances in the process of the reading and the writing, using themselves it room of computer science with pupils who presented difficulties for the development of these activities. For in such a way, the study it was of qualitative nature and it had as basement the readings of Brave, Papert, Freire and Emilia Ferreiro. The activities of written production had been collected in the computer science room and, in this process, the advances and the difficulties were analyzed; from there, defined new actions and strategies for the development of the project. The development of the research occurred at three distinct moments: an initial evaluation, when the pupils had presented a written production; after that, it had an intervention, counting on activities with the use of the computer; e, finally, a final evaluation, in which the pupils had presented a written production. The gotten results had been significant and contributed for the process of learning of the reading and the writing; however, in relation to the grammatical and norms, the pupils had still presented difficulties. He fits, therefore, to the educators to demystify the use of this technology and to use it knot process of education and learning of its pupils.  Nos últimos anos, observa-se que alunos dos ensinos Fundamental e Médio apresentam dificuldades na leitura e na escrita. Diante disso, com a presente pesquisa, busca-se contribuir para a melhoria da leitura e da escrita com o uso do computador. O objeto  é  o processo de aprendizagem de 12 alunos da 5ª série do Ensino Fundamental, com idades entre 11 e 13 anos, com deficiência na leitura e escrita. O objetivo da investigação refere-se aos avanços no processo da leitura e da escrita, utilizando-se a sala de informática com alunos que apresentavam dificuldades para o desenvolvimento destas atividades. Para tanto, o estudo foi de natureza qualitativa e teve como embasamento as leituras de Valente, Papert, Freire e Emilia Ferreiro. As atividades de produção escrita foram coletadas na sala de informática e, neste processo, eram analisados os avanços e as dificuldades; a partir daí, definidas novas ações e estratégias para o desenvolvimento do projeto. O desenvolvimento metodológico da pesquisa ocorreu em três momentos distintos: uma avaliação inicial, quando os alunos apresentaram uma produção escrita; em seguida, houve uma intervenção, contando com atividades com o uso do computador; e, finalmente, uma avaliação final, na qual os alunos apresentaram uma produção escrita. Os resultados obtidos foram significativos e contribuíram para o processo de aprendizagem da leitura e da escrita; entretanto, em relação às normas gramaticais e ortográficas, os alunos ainda apresentaram dificuldades. Cabe, portanto, aos educadores desmistificar o uso desta tecnologia e utilizá-la no processo de ensino e aprendizagem de seus alunos

A SIMPLE TECHINIQUE TO IMPROVE RESIDUAL SKIN PLASTICITY FOR SCROTAL RECONSTRUCTION IN FOURNIER'S GANGRENE

A 50 years-old man developed 24 hours after hemorroidectomy a severe Fournier's gangrene of the scrotum necessitating surgical exeresis of more than 2/3 of scrotal skin followed by hyperbaric oxygen therapy. After the resolution of the septic phase, scrotum reconstruction was obtained by tissue expansion to avoid more invasive advanced reconstructive techniques. The procedure consisted of an enzymatic and mechanical debridement and progressive skin expansion by package of gauzes of increasing volume covered with a collagenase-cloramphenicol ointment (Iruxol - Smith & Nephew, Italy), then closing the wound edges by temporary stitches to put under tension the skin. The reestablishement of the natural elasticity of the scrotal skin was obtained in ten days and at the final closure of the wound edges an acceptable optimal aesthtic result was achieved

INDÚSTRIAS LÁCTEAS: ALTERNATIVAS DE APROVEITAMENTO DO SORO DE LEITE COMO FORMA DE GESTÃO AMBIENTAL

Small and medium industries of dairy products in Brazil are facing serious problems of competition for the consumer market due to factors such as small scale production, lack of standardization of products and processes, deficiencies in effective control of quality, difficult to define niche markets and different levels of technology, although they are generating jobs and income. In addition to these factors, it appears that the control of environmental impacts caused by these industries, given the current environmental legislation, has forced a change of attitude on the part of entrepreneurs, in order to control pollution, despite the shortcomings often perceived in infrastructure linked to industrialization, such as high energy and water. The treatment and disposal of effluents and solid waste disposal, which are critical in industrial processes, are often overlooked in small and medium industries, generating significant environmental impacts. Among the main environmental impacts generated by the dairy industry stands to generate significant amounts of wastewater with high organic load. In this sense, the main objective of this study was a literature survey concerning the main factors of environmental impact of small and medium industries in the dairy sector, aiming to propose alternative environmental management that favors the minimization of the factors generating these impacts.As pequenas e médias indústrias de produtos lácteos no Brasil enfrentam sérios problemas de competição pelo mercado consumidor devido a fatores como: pequena escala de produção, falta de padronização de produtos e de processos, deficiências no controle efetivo de qualidade, dificuldade em definir nichos de mercado e níveis de tecnologia diferenciada, apesar de serem geradores de ocupação e renda. Aliado a estes fatores, constata-se que o controle dos impactos ambientais causados por essas indústrias, frente às atuais exigências da legislação ambiental, tem forçado uma mudança de atitude por parte dos empresários, no sentido de controlar a poluição, apesar das carências muitas vezes percebidas, na infra-estrutura ligada à industrialização, como o alto consumo energético e de água. O tratamento e lançamento de efluentes e a disposição de resíduos sólidos, que são críticos em processos industriais, freqüentemente são negligenciados nas médias e pequenas indústrias, gerando impactos ambientais relevantes. Dentre os principais impactos ambientais gerados pelas indústrias de laticínios destaca-se a geração de quantidades significativas de efluentes líquidos com elevada carga orgânica. Neste sentido, o objetivo principal deste trabalho foi realizar um levantamento literário referente aos principais fatores de impacto ambiental causado pelas pequenas e médias indústrias do setor lácteo, visando propor alternativas de gestão ambiental que oportunizasse a minimização dos fatores geradores destes impactos