Incidência do Pineapple Mealybug wilt Associated VÍrus, PMWAV no Banco Ativo de Germoplasma de abacaxi in vitro da Embrapa Mandioca e Fruticultura.

O abacaxi (Ananas comosus var. comosus) é uma das frutas tropicais mais apreciadas no mundo. O Brasil, como um dos centros de origem e diversidade genética, tem se preocupado com a conservação de germoplasma desta importante fruteira. O abacaxizeiro por ser de propagação vegetativa, possui a vantagem da multiplicação clonal do material de plantio, entretanto, esta prática favorece a disseminação de doenças como as viroses. O PMWaV (Pineapple mealybug wilt-associated virus) é um vírus que infecta o abacaxi causando a doença denominada popularmente de ?Mucha do abacaxi?. O vírus transmitido pela cochonilha Dysmicoccus brevipes, e atualmente, acredita-se que a doença seja causada por um complexo viral, denominados PMWaV-1, PMWaV-2 e PMWaV-3, que se diferenciam pela sequência e organização do genoma. O PMWV pertence a família Closteroviridae, gênero Ampelovirus, possui partícula alongada flexuosa e genoma de RNA fita simples com aproximadamente 14Kb. Além dos danos diretos na produção da planta, a contaminação dos acessos do Banco Ativo de Germoplasma -BAG é um fator preocupante. Diante disto, o objetivo deste trabalho foi a avaliar a incidência do PMWaV-1,2,3 nos acesso do BAG in vitro da Embrapa Mandioca e Fruticultura.PDF. 094

Topological vortices in generalized Born-Infeld-Higgs electrodynamics

A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born-Infeld-Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via introduction of three non-negative functions depending only in the Higgs field, namely, $G(|\phi|)$, $w(|\phi|)$ and $V(|\phi|)$. A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampere law. Such a constraint allows to minimize the system energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of topological vortex solutions in Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models such that a generalized version of Maxwell-Higgs electrodynamics is recovered in a certain limit of the theory.Comment: 8 pages, 8 figures, to appear in EPJ

Estudo de raízes de coqueiro anão verde em neossolos quartzarênicos da Fazenda São João, em Petrolina-PE.

O estudo foi desenvolvido em Neossolo Quartzarênico, que tem 96% de areia, 2% de silte e 2% de argila em área de plantio comercial da Fazenda São João, município de Petrolina - PE; cultivada com coqueiro anão ecotipo verde, com idade de 7 anos; plantado no espaçamento quiconcial de 7,5 x 7,5 x 7,5 metros, irrigado por microaspersão. Para irrigação utilizou-se um emissor por planta que disponibiliza uma vazão média de 40 L/h, para uma pressão de 204,00 kPa, com uma percentagem de área molhada de 48,70%. Duas plantas foram escolhidas como representativas da área para análise de distribuição de raízes no solo. Os resultados obtidos permitem estabelecer, que até a distância de 2,40 m do caule, estão concentrados 98,17% da área acumulada das raízes. No que se refere à profundidade e até a distância de 2,40 m, menos de 6% das raízes estão abaixo de 1,20 m. As raízes mais compridas e as de maior área estão localizadas entre 0,20 e 0,60 m de profundidade numa sequência crscente até a distância de 1,80 m

Analytical BPS Maxwell-Higgs vortices

We have established a prescription for the calculation of analytical vortex solutions in the context of generalized Maxwell-Higgs models whose overall dynamics is controlled by two positive functions of the scalar field. We have also determined a natural constraint between these functions and the Higgs potential allowing the existence of axially symmetric Bogomol'nyi-Prasad-Sommerfield (BPS) solutions possessing finite energy. Furthermore, when the generalizing functions are chosen suitably, the nonstandard BPS equations can be solved exactly. We have studied some examples, comparing them with the usual Abrikosov-Nielsen-Olesen (ANO) solution. The overall conclusion is that the analytical self-dual vortices are well-behaved in all relevant sectors, strongly supporting the generalized models they belong themselves. In particular, our results mimic well-known properties of the usual (numerical) configurations, as localized energy density, while contributing to the understanding of topological solitons and their description by means of analytical methods.Comment: 8 pages, 4 figure

Dynamical evolution of V-type asteroids in the central main belt

V-type asteroids are associated with basaltic composition, and are supposed to be fragments of crust of differentiated objects. Most V-type asteroids in the main belt are found in the inner main belt, and are either current members of the Vesta dynamical family (Vestoids), or past members that drifted away. However, several V-type photometric candidates have been recently identified in the central and outer main belt. The origin of this large population of V-type objects is not well understood. Since it seems unlikely that Vestoids crossing the 3J:-1A mean-motion resonance with Jupiter could account for the whole population of V-type asteroids in the central and outer main belt, origin from local sources, such as the parent bodies of the Eunomia, and of the Merxia and Agnia asteroid families, has been proposed as an alternative mechanism. In this work we investigated the dynamical evolution of the V-type photometric candidates in the central main belt, under the effect of gravitational and non-gravitational forces. Our results show that dynamical evolution from the parent bodies of the Eunomia and Merxia/Agnia families on timescales of 2 Byr or more could be responsible for the current orbital location of most of the low-inclined V-type asteroids.Comment: 16 pages, 10 figures, 3 tables. Accepted for publication in MNRA

Dynamical evolution and chronology of the Hygiea asteroid family

The asteroid (10) Hygiea is the fourth largest asteroid of the Main Belt, by volume and mass, and it is the largest member of its own family. Previous works investigated the long-term effects of close encounters with (10) Hygiea of asteroids in the orbital region of the family, and analyzed the taxonomical and dynamical properties of members of this family. In this paper we apply the high-quality SDSS-MOC4 taxonomic scheme of DeMeo and Carry (2013) to members of the Hygiea family core and halo, we obtain an estimate of the minimum time and number of encounter necessary to obtain a $3\sigma$ (or 99.7%) compatible frequency distribution function of changes in proper $a$ caused by close encounters with (10) Hygiea, we study the behavior of asteroids near secular resonance configurations, in the presence and absence of the Yarkovsky force, and obtain a first estimate of the age of the family based on orbital diffusion by the Yarkovsky and YORP effects with two methods. The Hygiea family is at least 2 Byr old, with an estimated age of $T = 3200^{+380}_{-120}$ Myr and a relatively large initial ejection velocity field, according to the approach of Vokrouhlick\'{y} et al. (2006a, b). Surprisingly, we found that the family age can be shortened by $\simeq$ 25% if the dynamical mobility caused by close encounters with (10) Hygiea is also accounted for, which opens interesting new research lines for the dynamical evolution of families associated with massive bodies. In our taxonomical analysis of the Hygiea asteroid family, we also identified a new V-type candidate: the asteroid (177904) (2005 SV5). If confirmed, this could be the fourth V-type object ever to be identified in the outer main belt.Comment: 13 page, 15 figures, and 4 table