Influência dos estressores bióticos Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae) e Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) na produtividade e qualidade tecnológica da cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Identificação em cana-de-açúcar de genes de resistência a Mahanarva fimbriolata (Stål, 1854) (Hemiptera: Cercopidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resistência de variedades de cana-de-açúcar à Cigarrinha-das-raízes Mahanarva fimbriolata (Stål) (Hemiptera, Cercopidae)

Pós-graduação em Agronomia - FEIS

Efeitos da fertirrigação sobre a ocorrência e danos de Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) em cana-de-açúcar

Brazil stands out as the world's largest producer of sugarcane and its productivity is closely related to the availability of water and nitrogen during its development and also to the incidence of pest insects. Among the species most harmful to the sugarcane in Brazil, Mahanarva fimbriolata stands out, which has seriously endangered the yields. In this context, the present study aimed to evaluate the effect of the nitrogen fertirrigation on the incidence and damage caused by M. fimbriolata in sugarcane. The experiment was composed of five treatments and four replications in a randomized block design (RBD). The treatments were composed of four doses of N-fertilizer and control (0, 50, 100, 150, 200 kg.ha-1) in drip irrigation system. The parameters evaluated were: number of nymphs in the roots, stalk productivity, sugar content, percentage of sugar, total recoverable sugar and the agricultural contribution margin. It was observed that the fertirrigation increases the productivity of stalks and sugar with the increase of nitrogen fertilization by irrigation. The use of 200 kg.ha-1 of N-fertilizer increased the incidence of M. fimbriolata up to the control and economic damage levels. The biggest financial yield was obtained with the dose of 150 kg.ha-1 of N-fertilizer.

Propagation of U235-238, Pu239 and STL Nuclear Data Uncertainties for PWR core analysis

An uncertainty propagation methodology based on Monte Carlo method is applied to PWR nuclear design analysis to assess the impact of nuclear data uncertainties in 235,238 U, 239 Pu and Scattering Thermal Library for Hydrogen in water. This uncertainty analysis is compared with the design and acceptance criteria to assure the adequacy of bounding estimates in safety margins.

UNDERSTANDING THE RELATIONSHIP BETWEEN THE BROWN MARMORATED STINK BUG, HALYOMORPHA HALYS (STÅL), AND ITS SYMBIONT, PANTOEA CARBEKII, WITH IMPLICATIONS FOR STINK BUG MANAGEMENT

Symbiotic relationships between insects and beneficial microbes are very common in nature, especially within the Hemiptera. The brown marmorated stink bug, Halyomorpha halys Stål, harbors a symbiont, Pantoea carbekii, within the fourth region of the midgut in specialized crypts. In this dissertation, I explored this insect- microbe relationship. I determined that the brown marmorated stink bug is heavily reliant on its symbiont, and that experimental removal of the symbiont from the egg mass surface prior to nymphal acquisition led to lower survival, longer development, lower fecundity, and aberrant nymphal behavior. Additionally, I determined that even when the symbiont is acquired and housed in the midgut crypts, it is susceptible to stressors. Stink bugs reared at a higher temperature showed lower survival, longer development, and a cease in egg mass production, and when bugs were screened for their symbiont, fewer had successfully retained it while under heat stress. Finally, with the knowledge that the stink bug suffers decreases in fitness when its symbiont is missing or stressed, I wanted to determine if targeting the symbiont was a possible management technique for the stink bug. I tested the efficacy of a number of different insecticidal and antimicrobial products to determine whether prevention of symbiont acquisition from the egg mass was possible, and results indicated that transmission of the symbiont from the egg mass to the newly hatched nymph was negatively impacted when certain products were applied (namely surfactants or products containing surfactants). Additionally, direct effects on hatch rate and survival were reported for certain products, namely the insect growth regulator azadirachtin, which suggests that nymphs can pick up residues from the egg mass surface while probing for the symbiont. I conclude that P. carbekii plays a critically important role in the survival of its host, the brown marmorated stink bug, and its presence on the egg mass surface before nymphal hatch makes it targetable as a potential management technique.

A smooth transition logit model of the effects of deregulation in the electricity market

This paper introduces the smooth transition logit (STL) model that is designed to detect and model situations in which there is structural change in the behaviour underlying the latent index from which the binary dependent variable is constructed. The maximum likelihood estimators of the parameters of the model are derived along with their asymptotic properties, together with a Lagrange multiplier test of the null hypothesis of linearity in the underlying latent index. The development of the STL model is motivated by the desire to assess the impact of deregulation in the Queensland electricity market and ascertain whether increased competition has resulted in significant changes in the behaviour of the spot price of electricity, specifically with respect to the occurrence of periodic abnormally high prices. The model allows the timing of any change to be endogenously determined and also market participants' behaviour to change gradually over time. The main results provide clear evidence in support of a structural change in the nature of price events, and the endogenously determined timing of the change is consistent with the process of deregulation in Queensland.

Paropsine beetles (Coleoptera: Chrysomelidae) in south-eastern Queensland hardwood plantations: identifying potential pest species

Paropsine chrysomelid beetles are significant defoliators of Australian eucalypts. In Queensland, the relatively recent expansion of hardwood plantations has resulted in the emergence of new pest species. Here I identify paropsine beetles collected from Eucalyptus cloeziana Muell. and E. dunnii Maiden, two of the major Eucalyptus species grown in plantations in south-eastern Queensland, and estimate the relative abundance of each paropsine species. Although I was unable to identify all taxa to species level, at least 17 paropsine species were collected, about one-third of which have not been previously associated with hardwood plantations. Paropsis atomaria Olivier and P. charybdis Stål were the most abundant species collected in E. cloeziana plantations, while Chrysophtharta cloelia (Stål) and P. atomaria were most commonly collected from E. dunnii. Occasional collections from Corymbia citriodora (Hook.) Hill and Johns, ssp. variegata revealed an additional four species implicated in plantation damage. Abundance and voltinism varied between species and sites. I predict which paropsine species are likely to threaten plantation productivity.

The effect of data sources and quality on the predictive capacity of CLIMEX models: an assessment of Teleonemia scrupulosa and Octotoma scabripennis for the biocontrol of Lantana camara in Australia

Understanding the effects of different types and quality of data on bioclimatic modeling predictions is vital to ascertaining the value of existing models, and to improving future models. Bioclimatic models were constructed using the CLIMEX program, using different data types – seasonal dynamics, geographic (overseas) distribution, and a combination of the two – for two biological control agents for the major weed Lantana camara L. in Australia. The models for one agent, Teleonemia scrupulosa Stål (Hemiptera:Tingidae) were based on a higher quality and quantity of data than the models for the other agent, Octotoma scabripennis Guérin-Méneville (Coleoptera: Chrysomelidae). Predictions of the geographic distribution for Australia showed that T. scrupulosa models exhibited greater accuracy with a progressive improvement from seasonal dynamics data, to the model based on overseas distribution, and finally the model combining the two data types. In contrast, O. scabripennis models were of low accuracy, and showed no clear trends across the various model types. These case studies demonstrate the importance of high quality data for developing models, and of supplementing distributional data with species seasonal dynamics data wherever possible. Seasonal dynamics data allows the modeller to focus on the species response to climatic trends, while distributional data enables easier fitting of stress parameters by restricting the species envelope to the described distribution. It is apparent that CLIMEX models based on low quality seasonal dynamics data, together with a small quantity of distributional data, are of minimal value in predicting the spatial extent of species distribution.

The hydrolytic reactivities of N-methyl-N(methylthiomethyl)acetamide and N-acetyl-1,3-thiazolidine: the influence of the sulfur atom

The sulfur atom in the substrates leads to modest enhancements in the titled phenomena: these are essentially derived from favourable enthalpies of activation, the negative entropies of activation possibly indicating a measure of stereoelectronic control.

A MATLAB Code for Three Dimensional Linear Elastostatics using Constant Boundary Elements

Present work presents a code written in the very simple programming language MATLAB, for three dimensional linear elastostatics, using constant boundary elements. The code, in full or in part, is not a translation or a copy of any of the existing codes. Present paper explains how the code is written, and lists all the formulae used. Code is verified by using the code to solve a simple problem which has the well known approximate analytical solution. Of course, present work does not make any contribution to research on boundary elements, in terms of theory. But the work is justified by the fact that, to the best of author’s knowledge, as of now, one cannot find an open access MATLAB code for three dimensional linear elastostatics using constant boundary elements. Author hopes this paper to be of help to beginners who wish to understand how a simple but complete boundary element code works, so that they can build upon and modify the present open access code to solve complex engineering problems quickly and easily. The code is available online for open access (as supplementary file for the present paper), and may be downloaded from the website for the present journal.

Microstructure and laser-induced damage threshold of ZrO2 coatings dependence on annealing temperature

ZrO2 coatings were deposited on different substrates of Yb:YAG and fused silica by electron beam evaporation. After annealed for 12 h at 673 and 1073 K, respectively, weak absorption of coatings was measured by surface thermal lensing (STL) technique, and then laser-induced damage threshold (LIDT) was determined also. The crystalline phase of ZrO2 coatings and the size of the crystal grain were investigated by X-ray diffraction. It was found that microstructure of ZrO2 coatings was dependent on both annealing temperature and substrate structure, and coatings containing monoclinic phases had higher damage threshold than others. Due to the strong absorption of Yb:YAG, damage threshold of coatings on Yb:YAG was much less than that on fused silica. (C) 2004 Elsevier B.V. All rights reserved.

Laser conditioning of ZrO2 : Y2O3/SiO2 mirror coatings prepared by E-beam evaporation

Laser conditioning effects of the dielectric mirror coatings with different designs were investigated. Simple quarter-wave ZrO2:Y2O3/SiO2 mirrors and half-wave SiO2 over-coated ZrO2:Y2O3/SiO2 mirror coatings were fabricated by E-beam evaporation (EBE). The absorbance of the samples before and after laser conditioning was measured by surface thermal lensing (STL) technology and the defects density was detected under Nomarski microscope. The enhancement of the laser damage resistance was found after laser conditioning. The dependence of the laser conditioning on the coating design was also observed and the over-coated sample obtained greatest enhancement, whereas the absorbance of the samples did not change obviously. During the sub-threshold fluence raster scanning, the minor damage about defects size was found and the assumption of pre-damage mechanism, based on the functional damage concept, was put forward. The improvement of the laser induced damage threshold (LIDT) was attributed to the benign damage of the defects and the dependence on the coating design owed to the damage growth behavior of different coating designs. (C) 2004 Elsevier B.V. All rights reserved.

表面热透镜薄膜吸收测量灵敏度提高方法

为提高表面热透镜薄膜吸收测量仪的灵敏度，在表面热透镜衍射理论基础上，通过数值模拟给出了探测激光腰斑半径、探测激光腰斑到样品表面距离、样品到探测光纤端面距离等仪器参数的优化方法．经优化调整后该仪器能达到优于0．1ppm量级的薄膜吸收率测量灵敏度．

表面热透镜技术应用于薄膜微弱吸收测量的理论和实验

由薄膜表面光热形变简化理论和表面热透镜衍射理论导出表面热透镜信号表达式,从理论上证明了表面热透镜信号和薄膜吸收率的线性关系.应用表面热透镜技术研制了薄膜吸收测量仪,测量结果表明其吸收率测量灵敏度和精度均达10-6量级.