Desenvolvimento, Produtividade E Atributos Qualitativos De Cultivares De Cana-de-açúcar Fertirrigadas Por Gotejamento Subsuperficial

The present study aimed to evaluate the development, yield and quality of four sugarcane cultivars fertigated by subsurface drip system. The experiment was carried out in Campinas-SP, Brazil, from January 2012 to November 2013, with the cultivars SP79-1011, IACSP94-2101, IACSP94-2094 and IACSP95-5000 subjected to daily irrigations. The irrigations depths were applied to bring soil moisture to field capacity. Soil moisture was monitored using soil moisture probes. Samples were collected along the crop cycle in order to evaluate crop development and yield, at the end of the first and second ratoons. Stalk height showed good correlation for the estimation of crop yield, with R2 equal to or higher than 0.96. The cultivar IACSP95-5000 showed the highest yield in the first ratoon. In the second ratoon the highest yield was observed in IACSP94-2101, followed by IACSP95-5000 and SP79-1011. Considering the yield results associated with the technological analysis, such as soluble solids content and apparent sucrose, the cultivar IACSP95-5000 excelled the others in the cultivation under subsurface drip irrigation. © 2016, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved.20652553

Dynamics of tournaments: the soccer case

A random walk-like model is considered to discuss statistical aspects of tournaments. The model is applied to soccer leagues with emphasis on the scores. This competitive system was computationally simulated and the results are compared with empirical data from the English, the German and the Spanish leagues and showed a good agreement with them. The present approach enabled us to characterize a diffusion where the scores are not normally distributed, having a short and asymmetric tail extending towards more positive values. We argue that this non-Gaussian behavior is related with the difference between the teams and with the asymmetry of the scores system. In addition, we compared two tournament systems: the all-play-all and the elimination tournaments.Comment: To appear in EPJ

Response of vegetation to fire disturbance: short-term dynamics in two savanna physiognomies

Fire is a constitutive ecological force in savanna ecosystems, but few studies have monitored its short-term effects on plant community dynamics. This study investigated changes in plant diversity in the South American savanna (Cerrado) after severe disturbance by fire. We monitored 30 permanent plots (10 m × 5 m) distributed in two Cerrado physiognomies (típico: more forested; ralo: grass-dominated), being 10 plots in the area disturbed by fire, and five in a preserved control area (undisturbed). From August 2010 to June 2011, we evaluated changes in species richness, abundance and composition of savanna vegetation. Monitoring started one week after the fire; disturbed plots were surveyed monthly, while control plots were surveyed every two months. We observed rapid reassembling in both physiognomies: plots affected by fire showed rapid increase in species richness and plant density during the first four months after the disturbance. Concerning species composition, disturbed plots in the cerrado típico tended to converge to control plots after one year, but each local assemblage followed particular temporal trajectories. A different pattern characterized cerrado ralo plots, which showed heterogeneous trajectories and lack of convergence between disturbed and control plots; the structure of these assemblages will likely change in next years. In conclusion, our results showed that fire significantly affected plant diversity in the two savanna physiognomies (cerrado típico and ralo), but also indicated that community reassembling is fast, with different dynamics between Cerrado physiognomies

Collective behavior of coupled nonuniform stochastic oscillators

Theoretical studies of synchronization are usually based on models of coupled phase oscillators which, when isolated, have constant angular frequency. Stochastic discrete versions of these uniform oscillators have also appeared in the literature, with equal transition rates among the states. Here we start from the model recently introduced by Wood et al. [Phys. Rev. Lett. 96}, 145701 (2006)], which has a collectively synchronized phase, and parametrically modify the phase-coupled oscillators to render them (stochastically) nonuniform. We show that, depending on the nonuniformity parameter $0\leq \alpha \leq 1$, a mean field analysis predicts the occurrence of several phase transitions. In particular, the phase with collective oscillations is stable for the complete graph only for $\alpha \leq \alpha^\prime < 1$. At $\alpha=1$ the oscillators become excitable elements and the system has an absorbing state. In the excitable regime, no collective oscillations were found in the model.Comment: 17 pages, 4 figure