Como previnir o tombamento em mudas de hortaliças.

bitstream/item/23626/1/lopes-como.pd

Aspectos citológicos e bioquímicos da interação entre Mycosphaerella fijiensis e Musa sp.

A bananeira é cultivada em todas as regiões tropicais do mundo, sendo a banana a fruta de maior produção e comercialização mundial. Entretanto, a cultura da banana enfrenta o ataque de diversos patógenos que contribuem para redução de sua produtividade, notadamente a sigatoka negra, causada pelo fungo Mycosphaerella fijiensis Morelet, estádio anamórfico Paracercospora fijiensis (Morelet) Deighton. Apresentando ampla distribuição geográfica, a sigatoka negra causa a morte precoce das folhas infectadas sendo responsável por perdas superiores a 50% da produção. Para se defenderem de doenças e pragas, as plantas estão equipadas com as defesas constitutivas, naturalmente presentes na planta, funcionando como barreiras físicas, tais como a cutícula e os tricomas, e barreiras químicas, incluindo os inibidores de proteases, fenóis, PR-Proteínas e enzimas do estresse oxidativo, e as defesas induzidas. Este trabalho relata as avaliações citológicas e bioquímicas decorrentes da interação entre o fungo M. fijiensis e Musa sp., demonstrando os índices de germinação e penetração de esporos e os níveis de atividades de enzimas ligadas ao mecanismo de defesa da bananeira

Contributions to knowledge on the maturation and fertility of the common octopus Octopus vulgaris Cuvier, 1797 on the Portuguese coast

The aim of the present study was to study the reproduction of the common octopus Octopus vulgaris Cuvier, 1797 at three locations on the mainland Portuguese coast. The results showed a higher occurrence of mature females in May-July and November at both Cascais and Santa Luzia, and in February and November at Viana do Castelo. Mature males were found year round. The fertility of females from Santa Luzia was higher (average of 230 000 oocytes), which could be due to this location's more favourable environmental conditions. At Cascais, the average was 140 000 oocytes, and at Viana do Castelo, 120 000. Our results could be useful in drawing up more suitable management measures for octopus Portuguese stocks.El objetivo es el estudio de la reproducción del pulpo común Octopus vulgaris Cuvier 1797 en tres localidades de la costa continental portuguesa. Los resultados demostraron un mayor registro de hembras maduras en mayo-julio y noviembre en Cascais y Santa Luzia, y en febrero y noviembre en Viana do Castelo. Hay machos maduros durante todo el año. La fecundidad de las hembras es mayor en Santa Luzia (con un promedio de 230 000 oocitos), lo que estaría asociado a las condiciones ambientales más favorables de esta localidad. En Cascais y Viana do Castelo el promedio fue de 140 000 y 120 000 oocitos, respectivamente. Estos datos podrán ser útiles para la propuesta de medidas más adecuadas para la gestión de las poblaciones de esta especie en las costas portuguesas.Instituto Español de Oceanografí

Características químicas de solos cultivados com laranjeira sob diferentes níveis de manejo, na microrregião do Guamá (PA).

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Proof-of-concept of a novel micro-bioreactor for fast development of industrial bioprocesses

The experimental performance of a novel micro-bioreactor envisaged for parallel screening and development of industrial bioprocesses has been tested in this work. The micro-bioreactor with an internal volume of 4.5mL is operated under oscillatory flow mixing (OFM), where a controllable mixing and mass transfer rates are achieved under batch or continuous laminar flow conditions. Several batch fermentations with a flocculent Saccharomyces cerevisiae strain were carried out at initial glucose concentrations (S0) range of ~5–20 g/L and compared to yeast growth kinetics in a stirred tank (ST) bioreactor. Aerobic fermentations were monitored ex situ in terms of pH, DO, glucose consumption, and biomass and ethanol production (wherever applicable). An average biomass production increase of 83% was obtained in the micro-bioreactor when compared with the ST, with less 93.6% air requirements. It also corresponded to a 214% increase on biomass production when compared with growth in a shaken flask (SF) at S0=20 g/L. Further anaerobic fermentations at the same initial glucose concentration ranges gave the opportunity to use state-ofthe-art fiber optics technology for on-line and real-time monitoring of this bioprocess. Time profiles of biomass concentration (measured as optical density (OD))were very similar in the ST bioreactor and in the micro-bioreactor, with a highly reproducible yeast growth in these two scale-down platforms.Fundação para a Ciência e a Tecnologia (FCT

Interference-aware iterative block decision feedback equalizer for single-carrier transmission

The deployment of increasingly dense heterogeneous mobile networks can create high levels of interference among users that, combined with severely time-dispersive channels, can result in substantial performance degradation. To cope with both effects, in this paper, we propose an iterative block decision feedback equalizer (IBDFE) for single carrier (SC) transmissions that makes use of the correlation between the interference in the receiving antennas and minimizes the mean squared error (MSE) of the detected symbols. Our analytic and simulated performance results show that the proposed receiver can clearly outperform the conventional IBDFE and the linear interference rejection combining (IRC) detector in severely time-dispersive channels with strong cochannel interference.info:eu-repo/semantics/acceptedVersio

Influence of the external pressure on the quantum correlations of molecular magnets

The study of quantum correlations in solid state systems is a large avenue for research and their detection and manipulation are an actual challenge to overcome. In this context, we show by using first-principles calculations on the prototype material KNaCuSi$_{4}$O$_{10}$ that the degree of quantum correlations in this spin cluster system can be managed by external hydrostatic pressure. Our results open the doors for research in detection and manipulation of quantum correlations in magnetic systems with promising applications in quantum information science

Finite size analysis of a two-dimensional Ising model within a nonextensive approach

In this work we present a thorough analysis of the phase transitions that occur in a ferromagnetic 2D Ising model, with only nearest-neighbors interactions, in the framework of the Tsallis nonextensive statistics. We performed Monte Carlo simulations on square lattices with linear sizes L ranging from 32 up to 512. The statistical weight of the Metropolis algorithm was changed according to the nonextensive statistics. Discontinuities in the m(T) curve are observed for $q\leq 0.5$. However, we have verified only one peak on the energy histograms at the critical temperatures, indicating the occurrence of continuous phase transitions. For the $0.5<q\leq 1.0$ regime, we have found continuous phase transitions between the ordered and the disordered phases, and determined the critical exponents via finite-size scaling. We verified that the critical exponents $\alpha$, $\beta$ and $\gamma$ depend on the entropic index $q$ in the range $0.5<q\leq 1.0$ in the form $\alpha (q)=(10 q^{2}-33 q+23)/20$, $\beta (q)=(2 q-1)/8$ and $\gamma (q)=(q^{2}-q+7)/4$. On the other hand, the critical exponent $\nu$ does not depend on $q$. This suggests a violation of the scaling relations $2 \beta +\gamma =d \nu$ and $\alpha +2 \beta +\gamma =2$ and a nonuniversality of the critical exponents along the ferro-paramagnetic frontier.Comment: accepted for publication in Phys. Rev.