Loss of redundant gene expression after polyploidization in plants

Based on chromosomal location data of genes encoding 28 biochemical systems in allohexaploid wheat,Triticum aestivum L. (genomes AABBDD), it is concluded that the proportions of systems controlled by triplicate, duplicate, and single loci are 57%, 25%, and 18% respectively

A unique Fock quantization for fields in non-stationary spacetimes

In curved spacetimes, the lack of criteria for the construction of a unique quantization is a fundamental problem undermining the significance of the predictions of quantum field theory. Inequivalent quantizations lead to different physics. Recently, however, some uniqueness results have been obtained for fields in non-stationary settings. In particular, for vacua that are invariant under the background symmetries, a unitary implementation of the classical evolution suffices to pick up a unique Fock quantization in the case of Klein-Gordon fields with time-dependent mass, propagating in a static spacetime whose spatial sections are three-spheres. In fact, the field equation can be reinterpreted as describing the propagation in a Friedmann-Robertson-Walker spacetime after a suitable scaling of the field by a function of time. For this class of fields, we prove here an even stronger result about the Fock quantization: the uniqueness persists when one allows for linear time-dependent transformations of the field in order to account for a scaling by background functions. In total, paying attention to the dynamics, there exists a preferred choice of quantum field, and only one $SO(4)$-invariant Fock representation for it that respects the standard probabilistic interpretation along the evolution. The result has relevant implications e.g. in cosmology.Comment: Typos correcte

Tracking the Evolution of A Coherent Magnetic Flux Rope Continuously from the Inner to the Outer Corona

The magnetic flux rope (MFR) is believed to be the underlying magnetic structure of coronal mass ejections (CMEs). However, it remains unclear how an MFR evolves into and forms the multi-component structure of a CME. In this paper, we perform a comprehensive study of an extreme-ultraviolet (EUV) MFR eruption on 2013 May 22 by tracking its morphological evolution, studying its kinematics, and quantifying its thermal property. As EUV brightenings begin, the MFR starts to rise slowly and shows helical threads winding around an axis. Meanwhile, cool filamentary materials descend spirally down to the chromosphere. These features provide direct observational evidence of intrinsically helical structure of the MFR. Through detailed kinematical analysis, we find that the MFR evolution experiences two distinct phases: a slow rise phase and an impulsive acceleration phase. We attribute the first phase to the magnetic reconnection within the quasi-separatrix-layers surrounding the MFR, and the much more energetic second phase to the fast magnetic reconnection underneath the MFR. We suggest that the transition between these two phases be caused by the torus instability. Moreover, we identify that the MFR evolves smoothly into the outer corona and appears as a coherent structure within the white light CME volume. The MFR in the outer corona was enveloped by bright fronts that originated from plasma pile-up in front of the expanding MFR. The fronts are also associated with the preceding sheath region followed the outmost MFR-driven shock.Comment: 9 pages, 6 figures, and 1 table, accepted by ApJ; any comments are welcome

Understanding the Evolutionary Relationships and Major Traits of \u3cem\u3eBacillus\u3c/em\u3e through Comparative Genomics

Background: The presence of Bacillus in very diverse environments reflects the versatile metabolic capabilities of a widely distributed genus. Traditional phylogenetic analysis based on limited gene sampling is not adequate for resolving the genus evolutionary relationships. By distinguishing between core and pan-genome, we determined the evolutionary and functional relationships of known Bacillus. Results: Our analysis is based upon twenty complete and draft Bacillus genomes, including a newly sequenced Bacillus isolate from an aquatic environment that we report for the first time here. Using a core genome, we were able to determine the phylogeny of known Bacilli, including aquatic strains whose position in the phylogenetic tree could not be unambiguously determined in the past. Using the pan-genome from the sequenced Bacillus, we identified functional differences, such as carbohydrate utilization and genes involved in signal transduction, which distinguished the taxonomic groups. We also assessed the genetic architecture of the defining traits of Bacillus, such as sporulation and competence, and showed that less than one third of the B. subtilis genes are conserved across other Bacilli. Most variation was shown to occur in genes that are needed to respond to environmental cues, suggesting that Bacilli have genetically specialized to allow for the occupation of diverse habitats and niches. Conclusions: The aquatic Bacilli are defined here for the first time as a group through the phylogenetic analysis of 814 genes that comprise the core genome. Our data distinguished between genomic components, especially core vs. pan-genome to provide insight into phylogeny and function that would otherwise be difficult to achieve. A phylogeny may mask the diversity of functions, which we tried to uncover in our approach. The diversity of sporulation and competence genes across the Bacilli was unexpected based on previous studies of the B. subtilis model alone. The challenge of uncovering the novelties and variations among genes of the non-subtilis groups still remains. This task will be best accomplished by directing efforts toward understanding phylogenetic groups with similar ecological niches

Phycomyces

This monographic review on a fungus is not addressed to mycologists. None of the authors has been trained or has otherwise acquired a general proficiency in mycology. They are motivated by a common interest in the performances of signal handling exhibited by the sense organs of all organisms and by the desire to attack these as yet totally obscure aspects of molecular biology by the study of a microorganism with certain desirable properties. The sporangiophore of the fungus Phycomyces is a gigantic, single-celled, erect, cylindrical, aerial hypha. It is sensitive to at least four distinct stimuli: light, gravity, stretch, and some unknown stimulus by which it avoids solid objects. These stimuli control a common output, the growth rate, producing either temporal changes in growth rate or tropic responses. We are interested in the output because it gives us information about the reception of the various signals. In the absence of external stimuli, the growth rate is controlled by internal signals keeping the network of biochemical processes in balance. The external stimuli interact with the internal signals. We wish to inquire into the early steps of this interaction. For light, for instance, the cell must have a receptor pigment as the first mediator. What kind of a molecule is this pigment? Which organelle contains it? What chemical reaction happens after a light quantum has been absorbed? And how is the information introduced by this primary photochemical event amplified in a controlled manner and processed in the next step? How do a few quanta or a few molecules trigger macroscopic responses? Will we find ourselves confronted with devices wholly distinct from anything now known in biology

Estudio de cúmulos estelares de la Nube Menor de Magallanes: fotometría de Washington de 14 cúmulos de edad intermedia

We present CCD photometry in the Washington system C and T1 bands of 14 star clusters of the Small Magellanic Cloud (SMC). We determine ages and metallicities using theoretical isochrones, the δT1 parameter and the Red Giant Standard method. Excepting IC 1708, all the observed clusters are aged between 1 and 6.3 Gyr, while their metallicities ([Fe/H]) range between -0.7 and -1.4. Two important cluster formation episodes in the SMC, dated at ∼ 2 Gyr and ∼ 5 Gyr ago, were detected. During approximately the first 4 Gyr in the SMC lifetime, the cluster formation rate turned out to be constant. A detailed version of this work can be seen in Piatti et al. (2011, MNRAS, 417, 1559).Presentamos fotometría CCD en las bandas C y T1 del sistema de Washington de 14 cúmulos estelares de la Nube Menor de Magallanes (NmM). Usando isócronas teóricas, el parámetro δT1 y el método de las Ramas Gigantes Estándar, determinamos edades y metalicidades. Excepto IC 1708, todos los cú- mulos observados tienen edades entre 1000 y 6300 millones de años y valores de [Fe/H] entre -0.7 y -1.4. Constatamos dos importantes episodios de formación de cúmulos en la NmM ocurridos hace ∼ 2 mil y ∼ 5 mil millones de años. Durante los primeros 4 mil millones de años desde que se formaron los cúmulos, la tasa de formación de los mismos se mantuvo constante. Una versión detallada de este trabajo puede verse en Piatti et al. (2011, MNRAS, 417, 1559).Fil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Bica, E.. Universidade Federal do Rio Grande do Sul; BrasilFil: Geisler, D.. Universidad de Concepción; ChileFil: Ahumada, Andrea Veronica. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Girardi, L.. Observatorio di Padova; Itali

A Comparative Study of Confined and Eruptive Flares in NOAA AR 10720

We investigate the distinct properties of two types of flares: eruptive flares associated with CMEs and confined flares without CMEs. Our sample of study includes nine M and X-class flares, all from the same active region (AR), six of which are confined and three others are eruptive. The confined flares tend to be more impulsive in the soft X-ray time profiles and show more slender shapes in the EIT 195 A images, while the eruptive ones are of long-duration events and show much more extended brightening regions. The location of the confined flares are closer to the center of the AR, while the eruptive flares are at the outskirts. This difference is quantified by the displacement parameter, the distance between the AR center and the flare location: the average displacement of the six confined flares is 16 Mm, while that of eruptive ones is as large as 39 Mm. Further, through nonlinear force-free field extrapolation, we find that the decay index of the transverse magnetic field in the low corona (~10 Mm) have a larger value for eruptive flares than that for confined one. In addition, the strength of the transverse magnetic field over the eruptive flare sites is weaker than that over the confined ones. These results demonstrate that the strength and the decay index of background magnetic field may determine whether or not a flare be eruptive or confined. The implication of these results on CME models is discussed in the context of torus instability of flux rope.Comment: 23 pages, 8 figures, 2 tables, ApJ in pres

Deep GALEX UV Survey of the Kepler Field. I. Point Source Catalog

We report observations of a deep near-ultraviolet (NUV) survey of the Kepler field made in 2012 with the Galaxy Evolution Explorer (GALEX) Complete All-Sky UV Survey Extension (CAUSE). The GALEX-CAUSE Kepler survey (GCK) covers 104 square degrees of the Kepler field and reaches a limiting magnitude of NUV ~ 22.6 at 3σ. Analysis of the GCK survey has yielded a catalog of 669,928 NUV sources, of which 475,164 are cross-matched with stars in the Kepler Input Catalog. Approximately 327 of 451 confirmed exoplanet host stars and 2614 of 4696 candidate exoplanet host stars identified by Kepler have NUV photometry in the GCK survey. The GCK catalog should enable the identification and characterization of UV-excess stars in the Kepler field (young solar-type and low-mass stars, chromospherically active binaries, white dwarfs, horizontal branch stars, etc.), and elucidation of various astrophysics problems related to the stars and planetary systems in the Kepler field

Aplicación de las Nuevas Tecnologías GPS-GPRS para el estudio del comportamiento y mejora de la producción de la raza de lidia

La dehesa es un ecosistema agroforestal único que aúna un óptimo rendimiento económico con una menor incidencia en el medio. En la Península Ibérica hay unas 500.000 hectáreas de dehesas concentradas en Andalucía, Castilla y León, Extremadura, Castilla La Mancha y Madrid. La raza de Lidia es, dentro de las razas autóctonas, por su rusticidad y adaptación, una de las que mejor aprovechan y conservan la dehesa. Las condiciones de cría en grandes fincas (400-500 hectáreas de media), el espacio por cabeza (entre una y seis hectáreas por animal), la movilidad que le da su menor tamaño con respecto a otras razas y su crecimiento en libertad con mínima presencia humana la ha hecho indispensables para el mantenimiento del ecosistema de la dehesa. Con este trabajo pretendemos aplicar una tecnología innovadora como es el GPS-GPRS a la monitorización de la etología del ganado de la raza de Lidia durante todos los periodos de su vida y especialmente en aquellos momentos en los que el animal se ve sometido a diferentes prácticas de manejo. Para ello, se implementará la tecnología de GPS que permite el posicionamiento relativo de un objetivo mediante la captación de la señal de diferentes satélites específicos, lo que proporcionará información precisa sobre: el desplazamiento del ganado en un periodo determinado, las distancias recorridas, el territorio pastoreado, las áreas más querenciosas, su ritmo circadiano, las pautas de comportamiento, etc. Así mismo, el dispositivo incorporará sensores de parámetros biológicos como la temperatura ó el ritmo cardíaco, etc. La implementación de este sistema permitirá, a través del posicionamiento, realizar la óptima gestión de los recursos pastables de la dehesa, permitiendo ahorrar costes en alimentación, infraestructuras y personal, y ofrecer, en un futuro cercano, una atractiva herramienta al ganadero para realizar el control remoto de sus reses