Distance statistics in random media: high dimension and/or high neighborhood order cases

Consider an unlimited homogeneous medium disturbed by points generated via Poisson process. The neighborhood of a point plays an important role in spatial statistics problems. Here, we obtain analytically the distance statistics to $k$th nearest neighbor in a $d$-dimensional media. Next, we focus our attention in high dimensionality and high neighborhood order limits. High dimensionality makes distance distribution behavior as a delta sequence, with mean value equal to Cerf's conjecture. Distance statistics in high neighborhood order converges to a Gaussian distribution. The general distance statistics can be applied to detect departures from Poissonian point distribution hypotheses as proposed by Thompson and generalized here.Comment: 5 pages and 2 figure

Generalized Metropolis dynamics with a generalized master equation: An approach for time-independent and time-dependent Monte Carlo simulations of generalized spin systems

The extension of Boltzmann-Gibbs thermostatistics, proposed by Tsallis, introduces an additional parameter $q$ to the inverse temperature $\beta$. Here, we show that a previously introduced generalized Metropolis dynamics to evolve spin models is not local and does not obey the detailed energy balance. In this dynamics, locality is only retrieved for $q=1$, which corresponds to the standard Metropolis algorithm. Non-locality implies in very time consuming computer calculations, since the energy of the whole system must be reevaluated, when a single spin is flipped. To circumvent this costly calculation, we propose a generalized master equation, which gives rise to a local generalized Metropolis dynamics that obeys the detailed energy balance. To compare the different critical values obtained with other generalized dynamics, we perform Monte Carlo simulations in equilibrium for Ising model. By using the short time non-equilibrium numerical simulations, we also calculate for this model: the critical temperature, the static and dynamical critical exponents as function of $q$. Even for $q\neq 1$, we show that suitable time evolving power laws can be found for each initial condition. Our numerical experiments corroborate the literature results, when we use non-local dynamics, showing that short time parameter determination works also in this case. However, the dynamics governed by the new master equation leads to different results for critical temperatures and also the critical exponents affecting universality classes. We further propose a simple algorithm to optimize modeling the time evolution with a power law considering in a log-log plot two successive refinements.Comment: 10 pages, 5 figures and 5 table

New record of Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) in the Cerrado vegetation of central Brazil

Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) has been reported to occur in south and southeastern Brazil, Paraguay and Argentina. Here we report the first occurrence of these rare flies in the Cerrado vegetation of central Brazil. We also provide an updated list of the geographical distribution of the 20 species of the genus Opetiops Enderlein, 1921 (1 species) and Pantophthalmus Thunberg, 1919 (19 species) in the Neotropical region.Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) has been reported to occur in south and southeastern Brazil, Paraguay and Argentina. Here we report the first occurrence of these rare flies in the Cerrado vegetation of central Brazil. We also provide an updated list of the geographical distribution of the 20 species of the genus Opetiops Enderlein, 1921 (1 species) and Pantophthalmus Thunberg, 1919 (19 species) in the Neotropical region

New record of Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) in the Cerrado vegetation of central Brazil

Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) has been reported to occur in south and southeastern Brazil, Paraguay and Argentina. Here we report the first occurrence of these rare flies in the Cerrado vegetation of central Brazil. We also provide an updated list of the geographical distribution of the 20 species of the genus Opetiops Enderlein, 1921 (1 species) and Pantophthalmus Thunberg, 1919 (19 species) in the Neotropical region.Pantophthalmus pictus (Wiedemann, 1821) (Diptera, Pantophthalmidae) has been reported to occur in south and southeastern Brazil, Paraguay and Argentina. Here we report the first occurrence of these rare flies in the Cerrado vegetation of central Brazil. We also provide an updated list of the geographical distribution of the 20 species of the genus Opetiops Enderlein, 1921 (1 species) and Pantophthalmus Thunberg, 1919 (19 species) in the Neotropical region

Análisis de la viabilidad de la implementación de la evaluación formativa en la enseñanza universitaria: estudio de caso de un proyecto de innovación docente en la Universidad de La Laguna

Los estudios sobre los sistemas de evaluación formativa vienen evidenciando el reconocimiento de ventajas para los agentes implicados. Sin embargo, en la enseñanza universitaria la regulación de la evaluación no está trascendiendo su carácter continuo. El propósito de esta investigación ha sido analizar la viabilidad de esos sistemas en la Educación Superior, a través del estudio de caso de un proyecto de innovación docente desarrollado en la Universidad de La Laguna (España) durante el curso 2011-2012. Se ha utilizado un procedimiento metodológico mixto, combinando el enfoque cualitativo del análisis de contenido de la opinión del alumnado (grupos de discusión), del profesorado (autoinformes) y de expertos (grupo de expertos), con la técnica cuantitativa del cuestionario para valorar la percepción de los estudiantes. Los resultados muestran que tanto el alumnado como el profesorado valoran muy positivamente estos sistemas de evaluación, principalmente por la manera en que contribuyen a potenciar el aprendizaje. Al mismo tiempo señalan algunos inconvenientes relacionados, sobre todo, con su mayor complejidad y la exigencia de un mayor esfuerzo. Por su parte, los expertos han diferenciado lo nuclear, especialmente ,lo concerniente al feedback formativo, de lo importante pero complementario de la evaluación formativa, como es el caso de la atención individualizada del alumnado y su participación en la negociación del propio sistema. Se constata que este tipo de evaluación es viable siempre que no se confunda lo nuclear con lo complementario y se evite un nivel de complejidad innecesario.The studies about formative assessment systems give evidence of the advantages for the agents implied. However, evaluation in the universities it not transcending its continuous character. The purpose of this piece of research has been to analyse this system in tertiary education through a case study done through an innovation programme in the University of La Laguna (Spain) during the course 2011-2012. We have used a mixed methodological approach combining a qualitative approach in the analysis of the opinions of the students, the teachers and the experts with a quantitative approach. The results show that both students and teachers value the evaluation system as very positive and that they enhance learning. At the same time they mention some inconveniences related mainly to bigger effort and more complexity. The experts, on the other hand, differentiate the essential part, especially regarding to formative feedback from the complementary, such as attention to the individual dimension of students. It is proved that this type of evaluation is always possible if we do not confuse the important elements with the essential ones and provided we do not give it more complexity that it should

Scale dependence and patch size distribution: clarifying patch patterns in Mediterranean drylands

In drylands, the underlying vegetation structure is associated with ecosystem functioning and ecosystem resilience. Although scale-dependent patterns are also predicted, empirical evidence often demonstrates that patch sizes are distributed according to a power-law probability distribution function or truncated power-law probability distribution function for a varied range of environmental conditions. Using satellite images and field measures, we assessed the spatial pattern of vegetation patches for a wide range of vegetation cover values in a large set of Mediterranean dryland (MDL) plots, focusing on the statistical distribution function that better fits the patch sizes. We found that power-law or truncated power-law probability distribution function does not always fit the observed patch size frequencies, while lognormal probability density function always fit well to them, implying that the vegetation structure is scale dependent for a large range of conditions. We show how the sampling approach, fit methods, and system dimensionality can affect the patch size distribution, which can explain some conflicting evidence obtained from the empirical data. Our findings question the robustness of criticality as the underlying mechanism driving vegetation patterns in MDLs. The better fit to patch size distribution provided by lognormal as compared with power-law indicates that multiplicative effects of multivariate local influences underlie pattern formation, and suggests that the role of plant–plant facilitation can be overestimated for a large range of conditions.Cristiano R.F. Granzotti acknowledges Capes and Alexandre S. Martinez acknowledges CNPq (307948/2014-5) for support. This work was supported by Sao Paulo Research Foundation (FAPESP) Grant No. 2013/06196-4 and Grant No. 2014/00631-3 and by the projects CASCADE (GA283068), funded by the European Commission, and DRYEX (CGL2014-59074-R), funded by the Spanish Ministry of Economy and Competitiveness

Escrever para inscrever-se: epistolografia homossexual nas páginas do Lampião da Esquina (1978-1981)

Este artigo analisa os textos da seção “Cartas na Mesa”, do jornal Lampião da Esquina (1978-1981), um dos famosos periódicos brasileiros voltados, sobretudo, para o público homossexual. Nessa seção, encontramos correspondências enviadas de diversos lugares do Brasil e veremos que um dos temas que parece se repetir é a questão do assumir-se gay. Portanto, apresento essas cartas e estudo os seus significados especialmente na relação com a identificação de uma identidade homossexual. Palavras-chave: Cartas de Leitores; Lampião da Esquina (Jornal); Homossexualidade; Assumir

Sistemática, filogenia e biogeografia do grupo Characidium lauroi Travassos, 1949 (Characiformes, Crenuchidae)

The "Characidium lauroi" group is composed by five species, that inhabit small mountains streams, such as the tributaries of the Iguaçu, Paranapanema, Tietê and Paraíba do Sul rivers, and coastal streams between Ilha Grande bay and Ribeira de Iguape. Four of these species were described by Haroldo Travassos between the 1940's and 1960's, Characidium lauroi, C. japuhybense, C. schubarti e C. oiticicai, and two of them are new to the science, Characidium sp. "piabanha" e Characidium sp. “iguaçu”. Three sinapomorphies corroborate the monophily of the group: absence of parietal branch in the head laterossensorial system; small number of cromatophores in the transversal bars; and small rounded spots along the side of the body. The phylogenetic relationships among these species suggest that the history of isolating events among of the headwaters of southeastern Brazil was important for the species diversification process. Characidium japuhybense, which occurs only in coastal rivers, is the most basal species. Characidium lauroi and Characidium sp. "piabanha" form a monophyletic clade that is endemic to upper and middle Paraíba do Sul river drainages. The sister group of this clade is comprised of species that occur in the Parana drainage. The relationships among C. schubarti, C. oiticicai and Characidium. sp. “iguaçu” clade are poorly resolved, thus suggesting a putative recent and complex separation between the headwaters of the rivers Iguaçu, Tietê, Paranapanema and Ribeira de Iguape.CAPESO "grupo Characidium lauroi" é formado por seis espécies que habitam pequenos riachos de montanha, tributários do rio Iguaçu, Paranapanema, Tietê, Paraíba do Sul, além dos rios costeiros entre a baía da Ilha Grande e a Ribeira de Iguape. Quatro dessas espécies foram descridas por Haroldo Travassos entre as décadas de 40 e 60, Characidium lauroi, C. japuhybense, C. schubarti e C. oiticicai, e duas são novas para a ciência, Characidium sp. "piabanha" e Characidium sp. “iguaçu”. Três sinapomorfias corroboram a monofilia do grupo: a ausência do ramo parietal do canal látero-sensorial da cabeça; barras tranversais com poucos cromatóforos; e presença de pequenas máculas arredondadas ao longo do flanco. As relações filogenéticas entre essas espécies sugerem que os eventos de separação das cabeceiras dos rios do sudeste foram importantes nos processos de especiação e diversificação do grupo. Characidium japuhybense, que ocorre apenas nos riachos costeiros, é a espécie mais basal do grupo. Characidium lauroi e C. sp. "piabanha" estão mais relacionadas com as espécies da bacia do Paraná do que com a anterior; entretanto, formam um clado monofilético endêmico das tributários do alto e médio rio Paraíba do Sul. As relações entre C. schubarti, C. oiticicai e Characidium sp. “iguaçu”, formam uma politomia, que demonstra uma suposta separação tardia entre e complexa as cabeceiras do Iguaçu, Tietê, Paranapanema e Ribeira de Iguape