First Record of Zelus obscuridorsis (Hemiptera: Reduviidae) as a Predator of the South American Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae)

The South American tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a Neotropical key pest of tomato in South America, and in recent years, it has become established in Europe and Africa. Recently we found the native true bug, Zelus obscuridorsis (Stål, 1860) (Hemiptera: Reduviidae), predating diverse mobile insects in household vegetable gardens located in northwestern Argentina. We found that Z. obscuridorsis preys on mobile stages of T. absoluta, i.e., free larvae and adults but not on larvae in their mines, pupae or eggs. This is the first record of a Zelus species as predator of T. absoluta. We discuss the importance of this predator consuming only mobile items, in terms of using little exploited host niches, and its possible relationships with other antagonistic species of T. absoluta.Fil: Speranza, Stefano. Universita Degli Studi Della Tuscia; ItaliaFil: Melo, María Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luna, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Virla, Eduardo Gabriel. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

High-resolution X-ray Spectra Of The Symbiotic Star SS73 17

SS73 17 was an innocuous Mira-type symbiotic star until Integral and Swift discovered its bright hard X-ray emission, adding it to the small class of "hard X-ray emitting symbiotics." Suzaku observations in 2006 then showed it emits three bright iron lines as well, with little to no emission in the 0.3-2 keV bandpass. We present here followup observations with the Chandra HETG and Suzaku that confirm the earlier detection of strong emission lines of Fe Kalpha fluorescence, Fe XXV and Fe XXVI but also show significantly more soft X-ray emission. The high resolution spectrum also shows emission lines of other highly ionized ions as Si XIV and possibly S XVI. In addition, a reanalysis of the 2006 Suzaku data using the latest calibration shows that the hard (15-50 keV) X-ray emission is brighter than previously thought and remains constant in both the 2006 and 2008 data. The G ratio calculated from the Fe XXV lines shows that these lines are thermal, not photoionized, in origin. With the exception of the hard X-ray emission, the spectra from both epochs can be fit using thermal radiation assuming a differential emission measure based on a cooling flow model combined with a full and partial absorber. We show that acceptable fits can be obtained for all the data in the 1-10 keV band varying only the partial absorber. Based on the temperature and accretion rate, the thermal emission appears to be arising from the boundary layer between the accreting white dwarf and the accretion disk.Comment: 7 pages, 5 figures. Accepted by the Astrophysical Journa

On the structure group of an infinite dimensional JB-algebra

We extend several results for the structure group of a real Jordan algebra V, to the setting of infinite dimensional JB-algebras. We prove that the structure group Str(V), the cone preserving group G(Ω) and the automorphism group Aut(V) of the algebra V are embedded Banach-Lie groups of GL(V), and that each of the inclusions Aut(V)⊂G(Ω)⊂Str(V) are of embedded Banach-Lie subgroups. We give a full description of the components of Str(V) via cones, isotopes and central projections. We apply these results to V=B(H)sa the special JB-algebra of self-adjoint operators on an infinite dimensional complex Hilbert space, describing the groups Str(V),G(Ω),Aut(V), their Banach-Lie algebras and their connected components. We show that the action of the unitary group of H on Aut(V) has smooth local cross sections, thus Aut(V) is a smooth principal bundle over the unitary group, with circle structure group S1.Fil: Larotonda, Gabriel Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; ArgentinaFil: Luna, Jose Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentin

Citrus psorosis virus movement protein contains an aspartic protease required for autocleavage and the formation of tubule-like structures at plasmodesmata

Plant virus cell-to-cell movement is an essential step in viral infections. This process is facilitated by specific virus-encoded movement proteins (MPs), which manipulate the cell wall channels between neighboring cells known as plasmodesmata (PD). Citrus psorosis virus (CPsV) infection in sweet orange involves the formation of tubule-like structures within PD, suggesting that CPsV belongs to "tubuleforming" viruses that encode MPs able to assemble a hollow tubule extending between cells to allow virus movement. Consistent with this hypothesis, we show that the MP of CPsV (MPCPsV) indeed forms tubule-like structures at PD upon transient expression in Nicotiana benthamiana leaves. Tubule formation by MPCPsV depends on its cleavage capacity, mediated by a specific aspartic protease motif present in its primary sequence. A single amino acid mutation in this motif abolishes MPCPsV cleavage, alters the subcellular localization of the protein, and negatively affects its activity in facilitating virus movement. The amino-terminal 34-kDa cleavage product (34KCPsV), but not the 20-kDa fragment (20KCPsV), supports virus movement. Moreover, similar to tubule-forming MPs of other viruses, MPCPsV (and also the 34KCPsV cleavage product) can homooligomerize, interact with PD-located protein 1 (PDLP1), and assemble tubule-like structures at PD by a mechanism dependent on the secretory pathway. 20KCPsV retains the protease activity and is able to cleave a cleavage-deficient MPCPsV in trans. Altogether, these results demonstrate that CPsV movement depends on the autolytic cleavage of MPCPsV by an aspartic protease activity, which removes the 20KCPsV protease and thereby releases the 34KCPsV protein for PDLP1-dependent tubule formation at PD. IMPORTANCE Infection by citrus psorosis virus (CPsV) involves a self-cleaving aspartic protease activity within the viral movement protein (MP), which results in the production of two peptides, termed 34KCPsV and 20KCPsV, that carry the MP and viral protease activities, respectively. The underlying protease motif within the MP is also found in the MPs of other members of the Aspiviridae family, suggesting that protease-mediated protein processing represents a conserved mechanism of protein expression in this virus family. The results also demonstrate that CPsV and potentially other ophioviruses move by a tubule-guided mechanism. Although several viruses from different genera were shown to use this mechanism for cell-to-cell movement, our results also demonstrate that this mechanism is controlled by posttranslational protein cleavage. Moreover, given that tubule formation and virus movement could be inhibited by a mutation in the protease motif, targeting the protease activity for inactivation could represent an important approach for ophiovirus control.Fil: Robles Luna, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Peña, Eduardo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Borniego, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Heinlein, Manfred. Université de Strasbourg; Francia. Centre National de la Recherche Scientifique; FranciaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Noninvasive imaging of the thirteen-lined ground squirrel photoreceptor mosaic.

Ground squirrels are an increasingly important model for studying visual processing, retinal circuitry, and cone photoreceptor function. Here, we demonstrate that the photoreceptor mosaic can be longitudinally imaged noninvasively in the 13-lined ground squirrel (Ictidomys tridecemlineatus) using confocal and nonconfocal split-detection adaptive optics scanning ophthalmoscopy using 790 nm light. Photoreceptor density, spacing, and Voronoi analysis are consistent with that of the human cone mosaic. The high imaging success rate and consistent image quality in this study reinforce the ground squirrel as a practical model to aid drug discovery and testing through longitudinal imaging on the cellular scale