6,698 research outputs found

    On strongly norm attaining Lipschitz maps

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    We study the set SNA(M,Y)\operatorname{SNA}(M,Y) of those Lipschitz maps from a (complete pointed) metric space MM to a Banach space YY which (strongly) attain their Lipschitz norm (i.e.\ the supremum defining the Lipschitz norm is a maximum). Extending previous results, we prove that this set is not norm dense when MM is a length space (or local) or when MM is a closed subset of R\mathbb{R} with positive Lebesgue measure, providing new examples which have very different topological properties than the previously known ones. On the other hand, we study the linear properties which are sufficient to get Lindenstrauss property A for the Lipschitz-free space F(M)\mathcal{F}(M) over MM, and show that all of them actually provide the norm density of SNA(M,Y)\operatorname{SNA}(M,Y) in the space of all Lipschitz maps from MM to any Banach space YY. Next, we prove that SNA(M,R)\operatorname{SNA}(M,\mathbb{R}) is weakly sequentially dense in the space of all Lipschitz functions for all metric spaces MM. Finally, we show that the norm of the bidual space of F(M)\mathcal{F}(M) is octahedral provided the metric space MM is discrete but not uniformly discrete or MM' is infinite.Comment: 28 pages, electronically published in the Journal of Functional Analysi

    In vitro regeneration and genetic fidelity of Tigridia pavonia (L.f.) DC.

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    Plants of Tigridia pavonia (L.f.) DC were regenerated from twin-scaling explants cultured on Murashige and Skoog and N6 basal medium. The highest formation of shoots per responding explant was obtained on N6 medium supplemented with 4.5 µM 2,4-dichlorophenoxy acetic acid in combination with 2.2 µM benzylaminopurine. Shoots rooted readily on N6 basal medium supplemented with 1 g l-1 activated charcoal and 2.6 µM naphtalenacetic acid. The rooted shoots achieved 100% survival. Inter Simple Sequence Repeat analysis was carried out to check for possible genetic alterations in plants obtained after two consecutive subcultures. The results revealed that the recovered plants did not exhibit any type of polymorphism

    Variety discrimination of Tigridia pavonia (L.f.) DC. assesed by different length RAPD primers

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    Tigridia pavonia (L.f.) DC. is one of the important phytogenetic resources of México. This species is used as ornamental, food and medicinal purposes. Despite its ornamental and economic potential, there is little information about the genetic variability. In this study, randomly amplified polymorphic DNA (RAPD) primers of 10, 15 and 20 bases were used to assess the level of genetic variation among nine botanical varieties of Tigridia pavoniacollected in three localities within State of México. The total number fragments, polymorphic fragments, percentage of polymorphism and resolving power were greater for 15 base (55, 52, 94.5 and 5, respectively) and 20 base (47, 45, 95.7 and 3.8, respectively), in comparison with those obtained from 10 base primers (44, 41, 93.1 and 3.6, respectively).Resultsshowed the major effectiveness of 15 and 20 bases RAPD primers in the genetic differentiation of varieties as compared to 10 bases RAPD primers. The dendrograms based on un-weighted pair group method arithmetic average (UPGMA) analysis of the 10, 15, 20 and the pooled (10, 15 and 20) bases RAPD data were consistent in the clustering varieties, grouping them in two main clusters

    Comparative study of the discriminating capacity of dna markers and their effectiveness in establishing genetic relationships in the genus tigridia

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    Tigridia Jussieu is an endemic genus to Mexico and taxonomically difficult with limited information about its genetic variability. A diversity assessment conducted using different DNA markers as an inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD) markers will be helpful in the establishment of a broad- based description for improved germplasm curation and the identification of germplasm for genome mapping and breeding of these species. Thus, the objective of this study was to characterize 15 wild species of Tigridia by using RAPD and ISSR molecular markers. This study was carried out in the laboratory of Plant Molecular Biology at the Faculty of Agricultural Sciences of the Universidad Autónoma del Estado de México between August and November of 2011. In this assay, 13 RAPD primers of 10, 15 and 20 b, and five ISSR primers of the anchored type (ASSR) of 17 b were used to assess the level of genetic variation among 15 wild species of Tigridia . With both markers there were 163 amplified bands of which 150 (92.02 %) were polymorphic. The RAPD primers of 10 b generated 12 specific bands with a polymorphism of 95.12 %, for 15 b primers those values were five and 82.93 %, and for 20 b primers eight and 94.59 %, respectively. The RAPD pooled primers presented a polymorphism of 90.76 %, the genetic distance (G D ) among the species ranged from 0.16 (between T. illecebrosa and T. huajuapanensis ) to 0.57 (between T. multiflora and T. augusta ). The ISSR primers showed more polymorphism(95.45 %) than RAPD primers. With ASSR primers the highest genetic association (G D = 0.89) was observed between T. mexicana ssp. mexicana and T. durangense , whereas the least related were T. vanhouttei spp. vanhouttei and T. multiflora (G D = 0.14). This study shows that 10 base random primers and 17 base anchored primers were more efficient to detect polymorphism and genetic differentiation among Tigridia species

    Outflow of hot and cold molecular gas from the obscured secondary nucleus of NGC3256: closing in on feedback physics

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    The nuclei of merging galaxies are often deeply buried in dense layers of gas and dust. In these regions, gas outflows driven by starburst and AGN activity are believed to play a crucial role in the evolution of these galaxies. However, to fully understand this process it is essential to resolve the morphology and kinematics of such outflows. Using near-IR integral-field spectroscopy obtained with VLT/SINFONI, we detect a kpc-scale structure of high-velocity molecular hydrogen (H2) gas associated with the deeply buried secondary nucleus of the IR-luminous merger NGC3256. We show that this structure is likely the hot component of a molecular outflow, which is detected also in the cold molecular gas by Sakamoto et al. This outflow, with a molecular gas mass of M(H2)~2x10^7 Msun, is among the first to be spatially resolved in both the hot H2 gas with VLT/SINFONI and the cold CO-emitting gas with ALMA. The hot and cold components share a similar morphology and kinematics, with a hot-to-cold molecular gas mass ratio of ~6x10^-5. The high (~100 pc) resolution at which we map the geometry and velocity structure of the hot outflow reveals a biconical morphology with opening angle ~40 deg and gas spread across a FWZI~1200 km/s. Because this collimated outflow is oriented close to the plane of the sky, the molecular gas may reach maximum intrinsic outflow velocities of ~1800 km/s, with an average mass outflow rate of at least ~20 Msun/yr. By modeling the line-ratios of various near-IR H2 transitions, we show that the H2 gas in the outflow is heated through shocks or X-rays to a temperature of ~1900K. The energy needed to drive the outflow is likely provided by a hidden Compton-thick AGN or by the nuclear starburst. We show that the global kinematics of the molecular outflow in NGC3256 mimic those of CO-outflows that have been observed at low spatial resolution in starburst- and active galaxies.Comment: Accepted in Astronomy and Astrophysics (accepted 29 Aug 2014 v.3, initial submission v.1 14 March 2014), 13 pages, 8 figure

    T35: a small automatic telescope for long-term observing campaigns

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    The T35 is a small telescope (14") equipped with a large format CCD camera installed in the Sierra Nevada Observatory (SNO) in Southern Spain. This telescope will be a useful tool for the detecting and studying pulsating stars, particularly, in open clusters. In this paper, we describe the automation process of the T35 and show also some images taken with the new instrumentation.Comment: 13 pages, 9 figures. Accepted for publication in the special issue "Robotic Astronomy" of Advances of Astronom

    Caracterización isoenzimática de nueve variedades botánicas de tigridia pavonia (l. f.) DC

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    Se estudiaron los patrones de bandeo isoenzimáticos (PBI) de nueve variedades botánicas de Tigridia pavonia (L. f.) DC., especie nativa de México con un alto potencial ornamental. Las variedades fueron recolectadas en tres municipios del Estado de México: Tenancingo (2100 m), Temascaltepec (2250 m) y Temoaya (2600 m). Como fuente de extracción de proteínas se usaron tejidos foliares de cada variedad. En los corrimientos se empleó la técnica de electroforesis horizontal en geles de almidón (SGE). Con SGE fueron ensayadas nueve isoenzimas: aspartato amino transferasa (AAT; EC 2.6.1.1), fosfatasa ácida (ACP; EC 13.1.3.2), catalasa (CAT; EC 1.11.1.6), malato deshidrogenasa (MDH; EC 1.1.1.37), 6-fosfogluconato deshidrogenasa (PGD; EC 1.1.1.44), fosfoglucosa isomerasa (PGI; EC 5.3.1.9), fosfoglucomutasa (PGM; EC 2.7.5.1), fosfohexosa isomerasa (PHI; EC 5.3.1.8) y peroxidasa (POX; EC 1.11.1.7). Se observaron 32 bandas arregladas en 20 PBI: dos para AAT, dos para ACP, dos para CAT, cuatro para MDH, uno para PGD, uno para POX, tres para PGI, tres para PHI y dos para PGM. La isoenzima más polimórfica fue MDH, mientras que PGD y POX no mostraron polimorfismo. Los datos de siete isoenzimas fueron usados para calcular las relaciones genéticas con el método UPGMA. Las variedades de T. pavonia pudieron ser diferenciadas una de otra, excepto las variedades Ángeles de Sandra y Carolina de Dulce, las cuales no pudieron distinguirse con los PBI observados. Las variedades Gloria y Samaria, recolectadas a 2600 m, presentaron mayor variación genética que las recolectadas a 2100 o 2250 m, lo cual podría atribuirse a la altitud. Se concluye que las isoenzimas pueden usarse para la diferenciación genética de variedades de T. pavonia

    Caracterización morfológica y molecular de nueve variedades botánicas de tigridia pavonia (l.f.) dc

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    Tigridia pavonia (L.f.) DC es una planta bulbosa nativa de México con potencial ornamental alto. México es considerado el centro de mayor diversidad de esta especie, por lo cual, el estudio de su diversidad genética y fenotípica es muy importante para establecer estrategias de manejo, conservación y utilización en programas de mejoramiento genético. El objetivo de este estudio fue caracterizar nueve variedades botánicas de Tigridia pavonia (L.f.) DC, con 21 marcadores morfológicos y cinco moleculares ISSR (ínter-Secuencias Simples Repetidas). Las variedades fueron recolectadas en tres municipios del Estado de México: Tenancingo (2100 m), Temascaltepec (2250 m) y Temoaya (2600 m). La distancia genética promedio para morfología fue 0.54, mientras que para ISSR fue 0.49. Así, ambos tipos de marcadores mostraron diversidad genética entre las variedades, distinguiendo a cada una de ellas. Los dendrogramas de los marcadores morfológicos e ISSR fueron notablemente similares, existiendo una correlación positiva entre ellos (R=0.30) y, en ambos casos, hubo una relación de las nueve variedades según su origen geográfico. Sin embargo, los marcadores ISSR fueron más efectivos, pues con un solo iniciador se distinguió a todas las variedades de T. pavonia. Se concluye que los marcadores ISSR son una herramienta útil para la discriminación rigurosa de genotipos y que se pueden usar de manera complementaria a la caracterización morfológica

    Caracterización del lirio azteca mediante marcadores morfológicos y moleculares

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    El lirio azteca [Sprekelia formosissima (L.) Herbert] es una especie endémica de México. Su color rojo escarlata y la forma de su flor le confieren un gran potencial para usarse como planta ornamental y como flor de corte, flor en maceta y paisajismo. Por tanto, cuatro variedades botánicas de S. formosissima fueron evaluadas mediante 29 descriptores varietales y cinco iniciadores anclados (ASSR), con el propósito de conocer la eficiencia de cada uno de los marcadores en la diferenciación de variedades de S. formosissima y, además, determinar la posible relación entre la variabilidad genética y la altitud geográfica de recolecta de las cuatro variedades de S. formosissima. Los iniciadores ASSR generaron 57 a 100 % de polimorfismo. Con tres de los cinco iniciadores fue posible distinguir cada una de las variedades entre sí, generando un perfil molecular para su identificación inequívoca. Los ASSR fueron más eficientes al detectar una mayor variabilidad genética (DG=0.5) con respecto a los morfológicos (DG=0.3). La correlación basada entre la distancia genética y la altitud para el análisis morfológico no fue significativa;,además, el análisis molecular no mostró una correlación entre ambos factores
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