Scattering between wobbling kinks

In this paper the scattering between a wobbling kink and a wobbling antikink in the standard $\phi^4$ model is numerically investigated. The dependence of the final velocities, wobbling amplitudes and frequencies of the scattered kinks on the collision velocity and on the initial wobbling amplitude is discussed. The fractal structure becomes more intricate due to the emergence of new resonance windows and the splitting of those arising in the non-excited kink scattering. Outside this phase the final wobbling amplitude exhibits a linear dependence of the collision velocity whereas the final frequency is a decreasing function. By contrast these magnitudes are almost independent of the initial wobbling amplitude.Comment: 20 pages, 13 figure

Wobbling kinks in a two-component scalar field theory: Interaction between shape modes

In this paper the interaction between the shape modes of the wobbling kinks arising in the family of two-component MSTB scalar field theory models is studied. The spectrum of the second order small kink fluctuation in this model has two localized vibrational modes associated to longitudinal and orthogonal fluctuations with respect to the kink orbit. It has been found that the excitation of the orthogonal shape mode immediately triggers the longitudinal one. In the first component channel the kink emits radiation with twice the orthogonal wobbling frequency (not the longitudinal one as happens in the $\phi^4$-model). The radiation emitted in the second component has two dominant frequencies: one is three times the frequency of the orthogonal wobbling mode and the other is the sum of the frequencies of the longitudinal and orthogonal vibration modes. This feature is explained analytically using perturbation expansion theories.Comment: 28 pages, 11 figure

Efeito do recobrimento de sementes de algodão sobre sua qualidade fisiológica.

A encapsulação de sementes com materiais de cobertura e o uso de equipamentos adequados constitui-se numa técnica simples e eficiente que permite alterar a forma e o tamanho das sementes, podendo facilitar a realização da semeadura de precisão. Com o presente trabalho, objetivou-se estudar o processo de revestimento e seus efeitos sobre a qualidade fisiológica de sementes de algodão. O experimento foi constituído por uma combinação fatorial de três classes de sementes de acordo com sua massa específica (classe 1 - >110 mg, classe 2 - entre 90 e 109,9 mg e classe 3 - <89,9 mg ) e dois tratamentos de recobrimento (com recobrimento e sem recobrimento). Foi adotado o delineamento inteiramente casualizado, com quatro repetições. Para o processo de encapsulação, foi utilizado pó fino, composto pela mistura de três integrantes, sendo dois agentes encapsulantes e um adesivo. As variáveis analisadas foram percentagem de germinação, comprimento de plântulas (vigor) e massa de cem sementes. Os resultados indicaram que o recobrimento aumenta a massa das sementes e não ocasiona alteração na qualidade fisiológica das sementes

Pemetrexed na segunda linha de tratamento do carcinoma do pulmão de não pequenas células – A experiência portuguesa

AbstractUntil 2004, docetaxel in monotherapy was the standard for second-line treatment of non-small cell lung cancer (NSCLC). Pemetrexed (P) has shown similar activity in this setting with a better adverse event profile. In Portugal, it was introduced in October of 2004.We have carried out a retrospective analysis of patients (pts) who received P for second-line NSCLC in Portugal from October 2004 to December 2006. Data were collected from the records of pts with locally advanced or metastatic NSCLC and failed first-line chemotherapy enrolled in centers participating in the Portuguese Lung Cancer Study Group (GECP). Objective response (OR; complete [CR] or partial [PR] response) was evaluated using RECIST and safety was assessed using serious or non-serious adverse events (SAEs/AEs).By December 2006, 19 GECP centers had enrolled 244 pts who had received P for ≥1cycle, and were considered evaluable for both objective response and safety. Demography: male/female, 175/69; median age, 57.0years (range 20-81); smoking status, y/ex/n, 116/57/71; adenocarcinoma / squamous-cell carcinoma/other histology, 141/72/31; mean time to progression (TTP) 8.07months. Disease control in 209 evaluable pts was observed in 116 (55.5%): 2 CR, 45 PR and 69 SD; mean TTP 4.70months. The majority of AEs were grade 3 anemia (15 pts) and neutropenia (18 pts). The mean overall survival was 17.27months.Our retrospective analysis has observed a similar disease control rate with P in 2nd line (55.5%), and TTP (4.7months) in our current unselected population to that published in the literature. P is an option for second-line NSCLC with a good tolerability.Rev Port Pneumol 2008; XIV (Sup.2): S9-S2

Active phloem sap collection by Trigona spinipes (Fabricius) (Hymenoptera, Apidae) in Artemisia annua Linn (Asteraceae).

Abstract: Trigona spinipes Fabricius (Apidae: Meliponini), is a common stingless bee widely seen in urban and rural areas in Brazil, popularly known as irapuá, arapuá or bee-dog. Although these bees are considered pollinators of some cultivated plants, they are better known for the damage they cause in different crops. During experimental agroecological cultivation of Artemisia (Artemisia annua Linn, Asteraceae), in Jaguariúna (SP, Brazil), stingless bees Trigona spinipes (Fabricius) were observed sucking phloem sap directly from the plant, a phenomenon not yet described in scientific literature. This study aimed to register and describe the phloem sap-sucking behavior performed by T. spinipes for the first time, as well as to assess the potential impact of this behavior on A. annua cultivation. The behavior and the material collected by bees and the severity of attack were also analyzed. The aging and premature death of observed A. annua specimens occurred because of extensive lesions caused by T. spinipes, confirming the negative consequence of sap-sucking attacks of T. spinipes bees on the plants. Factors that could induce this unusual behavior were presented, pointing out the need for future studies on the development of strategies to protect plants, without causing damage to the T. spinipes bee populations, which are elements of Brazilian bee fauna and, therefore, protected by law

Estratégias de manejo de solos em sistema agroflorestal em lote da reforma agrária.

Resumo: Sistemas Agroflorestais - sistemas embasados pelos princípios da agroecologia, o manejo dos solos deve levar em consideração a ciclagem de nutrientes, o teor de matéria orgânica e o equilíbrio entre os componentes vivos e não vivos do solo. Este artigo busca resgatar as estratégias utilizadas por um agricultor que trabalha com sistemas agroflorestais há 4 anos, evidenciando o manejo da biomassa, as espécies escolhidas, os motivos, a época de plantio e capina e os resultados observados por ele. A propriedade esta situada no Assentamento Sepé Tiaraju, localizado na região de Ribeirão Preto, SP, que constitui-se o primeiro assentamento ecológico do Estado de São Paulo. O manejo da biomassa é a principal estratégia de uso, manejo e conservação de solo para o sistema agroflorestal em estudo, o qual é caracterizado como sucessional e bastante biodiverso. As principais plantas utilizadas são: urucum (Bixa orellana), bananeira (Musa sp), mamona (Ricinus communis) e as leguminosas como o feijão de porco (Canavalia ensiformis), crotalarias (Crotalaria sp), feijão guandu (Cajanus cajan) e fedegoso (Cassia spectabilis). Vê-se que o agricultor tende a retirar do sistema as gramíneas, substituindo-as por plantas de mais fácil manejo como as leguminosas, caracterizando mudanças nas condições físicas, químicas e biológicas do solo que são descritas na bibliografia cientifica. Abstract: Agroforestry - systems based in the principles of agroecology, soil management should take into consideration the cycling of nutrients, organic matter content and balance between living and nonliving components of soil. This article seeks to rescue the strategies used by one farmer that work with agroforestry systems for 4 years, emphasizing the management of biomass, the species chosen, the reasons, the time of planting and weeding, and the results observed by owner This farm is located the Sepé Tiarauú settlement, in Ribeirão Preto, SP, which constitutes in the first ecological settlement in state of São Paulo. The management of biomass corresponds to the main strategy use, management and soil conservation in agroforestry system in study, which is characterized as successional and highly biodiverse. The main plants components used are: ?urucum? (Bixa orellana), banana (Musa sp), castobean (Ricinus communis) and legumes like ?feijão de porco? (Canavalia ensiformis), Crotalaria (Crotalaria sp), pigeon pea (Cajanus cajan) and ?fedegoso? (Cassia spectabilis). It is seen that the farmer tends to put the grass out of the system, replacing them with plants easier to work as Leguminosae family, featuring changes in physical, chemical and biological conditions of soil

Sistemas biodiversos em assentamentos rurais: monitoramento, papel do conhecimento e especulações sobre políticas públicas.

No presente escrito são descritas as ações da Equipe de Agroecologia da Embrapa Meio Ambiente na construção do conhecimento agroecológico em assentamentos rurais do Estado de São Paulo, indicando fases, métodos e impactos ecológicos e socioeconômicos no âmbito dos lotes. O foco destas ações foi a implantação de sistemas biodiversos, na forma de agroflorestas. Posteriormente a equipe desenvolveu diversos esforços para conceber e aplicar planos de monitoramento dos sistemas manejados. A fase inicial de evolução deste empreendimento resultou em interessantes dados qualitativos sobre diversos aspectos dos sistemas agroflorestais. O trabalho finaliza pontuando questões emergentes e desafios como o de desenvolver e validar estratégias metodológicas de análise integrada de sistemas agroecológicos biodiversos como base para reforçar sua estabilidade, sua aplicação socialmente ampliada e sua consolidação econômica, sócio-cultural e política