Numerical simulation of random paths with a curvature dependent action

We study an ensemble of closed random paths, embedded in R^3, with a curvature dependent action. Previous analytical results indicate that there is no crumpling transition for any finite value of the curvature coupling. Nevertheless, in a high statistics numerical simulation, we observe two different regimes for the specific heat separated by a rather smooth structure. The analysis of this fact warns us about the difficulties in the interpretation of numerical results obtained in cases where theoretical results are absent and a high statistics simulation is unreachable. This may be the case of random surfaces.Comment: 9 pages, LaTeX, 4 eps figures. Final version to appear in Mod. Phys. Lett.

Fixed boundary conditions analysis of the 3d Gonihedric Ising model with κ=0\kappa=0

The Gonihedric Ising model is a particular case of the class of models defined by Savvidy and Wegner intended as discrete versions of string theories on cubic lattices. In this paper we perform a high statistics analysis of the phase transition exhibited by the 3d Gonihedric Ising model with $k=0$ in the light of a set of recently stated scaling laws applicable to first order phase transitions with fixed boundary conditions. Even though qualitative evidence was presented in a previous paper to support the existence of a first order phase transition at $k=0$, only now are we capable of pinpointing the transition inverse temperature at $\beta_c = 0.54757(63)$ and of checking the scaling of standard observables.Comment: 14 pages, 5 tables, 2 figures, uses elsart.cls packag

Random paths with curvature

We present some results coming from a Monte Carlo simulation of a set of random paths with a curvature dependent action. This model can be considered as a toy model of the theory of random surfaces. The transition from free to rigid random paths has been analyzed and the similitude with the crumpling transition have been pointed out.Comment: 4 pages, 5 Postscript figures, epsf.tex A postscript version is available at ftp://ftp.ifae.es/preprint/ft/uabft396.ps Poster presented in Lattice'96 conferenc

Evaluación de la doble inoculación Bradyrhizobium-micorrizas y el uso de fitoterápicos de semilla en el crecimiento, eficiencia de inoculación y el rendimiento de un cultivo de soja

La problemática de la fertilidad de suelos adquiere relevancia en la producción agrícola en general y en el cultivo de soja en particular. El interés creciente por los biofertilizantes surge de la necesidad de desarrollar alternativas más limpias y menos costosas para suministrar nutrientes a las plantas. La inoculación con Bradyrhizobium japonicum y hongos formadores de micorrizas arbusculares (HFMA) Glomus mosseae, es una alternativa a tener en cuenta. El objetivo de este trabajo fue evaluar el efecto de la doble inoculación Bradyrhizobium-micorrizas y su interacción con fitoterápicos de semillas, sobre el crecimiento y rendimiento final de Glycine max. El ensayo se llevó a cabo sobre un cultivo de soja, implantado en el partido de Lobos en la provincia de Buenos Aires. Se estableció un diseño experimental en bloques al azar, con cuatro repeticiones por tratamiento. Los tratamientos fueron: Control sin inoculación (C); Inoculación con B. japonicum (IB); Inoculación combinada Bradyrhizobium-micorrizas (IBM); Inoculación con Bradyrhizobium + curasemilla (IBC); Inoculación combinada + curasemilla (IBMC). Se determinaron parámetros de crecimiento, eficiencia de nodulación y micorrización, rendimiento y sus componentes. Comparados con el control, IBM e IBMC mostraron un aumento significativo, del orden del 40 %, en los parámetros de crecimiento. Todos los tratamientos aumentaron significativamente el número de plantas noduladas, comparados con el control. El número de nódulos por planta aumentó significativamente en todos los tratamientos de inoculación, con mayor nodulación en los tratamientos de inoculación combinada, comparados con los de inoculación simple. Sólo los tratamientos IBM e IBMC aumentaron significativamente el porcentaje de raíces micorrizadas, comparados con el control. Los tratamientos IB, IBC e IBMC aumentaron significativamente el rendimiento, con valores de 4.750, 4.825 y 4.850 Kg ha-1, respectivamente, comparados con el control (4.100 Kg ha-1). El rendimiento se incrementó significativamente en los tratamientos con doble inoculación y fitoterápicos de semilla (IBMC) y en aquellos con simple inoculación con B. japonicum, independientemente de la aplicación de fitoterápicos de semilla (IB e IBC).Soil fertility is a relevant aspect of agricultural production, particularly so in soybean crops. Biofertilizers such as Bradyrhizobium japonicum and arbuscular mycorrhizal fungi (AMF) are studied in order to find sustainable alternatives to providing crops with mineral nutrients. The aim of this work was to study the effect of the coinoculation of Bradyrhizobium-mycorrhizal fungi on the growth and yield of Glycine max and its interaction with the fungicides applied to seeds. The experiment was conducted on a soybean crop planted at Lobos, Buenos Aires province. The treatments were: Control: no inoculation (C); Inoculation with B. japonicum (IB); combined inoculation of Bradyrhizobium-mycorrhizal (IBM); Inoculation with Bradyrhizobium + fungicides (IBC); combined inoculation + fungicides (IBMC). In the experiment the following were determined: growth parameters, nodulation and mycorrhization efficiency, and yield and its components. The IBM and IBMC treatments showed a significant increase in growth parameters, around 40% compared to control. All treatments significantly increased the number of nodulated plants compared with the control. The number of nodules per plant was significantly higher in all inoculated treatments compared with the control, and the highest values were observed with the co-inoculation treatments as compared with single inoculation treatments. IBM and IBMC treatments increased the percentage of mycorrhizal roots compared with the control. IB, IBC, and IBMC treatments showed a significant increase in yield: 4,750 Kg ha-1; 4,825 Kg ha-1, and 4,850 Kg ha-1, respectively, compared with the control (4,100 Kg ha-1). The yield was increased in the combined inoculation and fungicide (IBMC) treatments and those inoculated with Bradyrhizobium japonicum only, independently of fungicide use (IB and IBC).Gerencia de Comunicación e Imagen InstitucionalFil: Clua, Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Olgiati, J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Beltrano, J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; Argentina. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentin

Anti-austerity between militant materialism and real democracy: exploring pragmatic prefigurativism

The anti-austerity movement that emerged in the wake of the 2008 global economic crisis and 2010 Eurozone crisis, and which forms part of the ‘age of austerity’ that came after those crises, was underpinned by a set of ideas and practices that we refer to here as ‘pragmatic prefigurativism’. Whilst the anti-austerity movements typically rejected formal ideologies such as Marxism and anarchism, nevertheless pragmatic prefigurativism can be understood as a ‘left convergence’ of sorts. The paper explores the features of this pragmatic prefigurativism, comparing the anti-austerity movements in the UK and Spain. In particular, we note the role of unresponsive institutions of democracy in prompting the move towards pragmatic prefigurativism, the adoption of techniques of direct democracy and direct action as the means through which to express a voice and to refuse austerity, and the pragmatic nature of the subsequent (re)turn to political institutions when this became a possibility

Challenging the age of austerity: Disruptive agency after the global economic crisis

This article explores the different forms of disruptive subjectivity that have developed in the context of the post-2008 global and European crises. The article traces developments both before and after 2008, with a specific focus on events in Spain and the UK. These country contexts are chosen due to their considerable differences in terms of the impact that the crisis had; yet we witness notable similarities with regard to the instances of refusal and resistance observed, especially in terms of the motives held and forms adopted, albeit with differences in scale. The paper presents the results of qualitative research, including 65 in-depth interviews, to highlight the way in which disaffection, the search for voice, and the threat of withdrawal from relations of exploitation have each become problematic as means of dissent following 2008. As a result, we have seen a merging of these more conventional forms of dissent with a number of more radical prefigurative practices that had been developing prior to 2008. As a result, the stagnation of neoliberal capitalism from 2008 onwards has witnessed the development of a new form of pragmatically prefigurative disruptive subjectivity, responsible for some of the more important and interesting political developments in contemporary advanced industrial democracies