Chemotaxonomy of Parthenium: P. Hysterophorus—P. Glomeratum

Fuente, Juana R. de la; Novara, Lázaro; Alarcón, Silvia R.; Díaz, Oscar J.; Uriburu, María L.; Sosa, Virginia E.

doi:10.1016/s0031-9422(97)00086-1

Cited by 25 publications

(26 citation statements)

References 13 publications

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“…We find that arguments against approximately isotropic models of N -flation [15] and kinetic alignment [14,23] are robust. The most difficult scenario to rule out arises from loopholes pointed out by de la Fuente, Saraswat, and Sundrum [48,65]. We present conjectured bounds on this scenario that depend on the way that the mass spectrum shifts as the axion VEVs are varied.…”

Section: Introductionmentioning

confidence: 76%

“…The original weak gravity paper [39] posited a "strong form" of the WGC, which stipulates that in theories with a single U (1), the lightest charged particle in the spectrum, and not just any charged particle, should have a charge-to-mass ratio larger than that of an extremal black hole. As pointed out in [48,65] and later discussed in [49,[51][52][53][54], there is a loophole in the electric WGC which leaves open the possibility of axion inflation, but which would be closed by this strong form of the WGC. In particular, consider a theory with a single axion a and two instantons of action S 1 S 2 and associated decay constants f 1 , f 2 , respectively.…”

Section: Assessing Strong Conjecturesmentioning

confidence: 87%

“…If we want to focus on large instanton actions so that higher-order corrections to the potential are exponentially suppressed, this shows that we require f /q < ∼ M Pl , where f /q is the field range determined by this potential. As recently emphasized in [48,65], this argument is not completely convincing because there is a "small action loophole": the prefactor in front of higher-instanton terms can suppress them even if the instanton action S 1. Direct calculation confirms that the potential is a sum of terms proportional to exp(−2πnmR) cos(na/f ) with coefficients decreasing with powers of n [13,69,70].…”

Section: Wgc and Single-axion Inflation: Electric Argumentmentioning

confidence: 99%

“…The first case we consider is that the same charges (1,0) and (N, 1) that control the axion potential also are responsible for satisfying the electric WGC. The argument of [48], emphasized to us by the authors [65], is that once the magnetic WGC constraint that f A , f B < ∼ M Pl is imposed, there is no further WGC constraint. The charged particles can be arbitrarily light, and direct calculation confirms that higher instanton contributions are numerically small.…”

Section: Case 1: Dominant Instantons Satisfy Electric Wgcmentioning

confidence: 99%

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Weak gravity strongly constrains large-field axion inflation

Heidenreich

Reece

Rudelius

2015

J. High Energ. Phys.

137

208

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Models of large-field inflation based on axion-like fields with shift symmetries can be simple and natural, and make a promising prediction of detectable primordial gravitational waves. The Weak Gravity Conjecture is known to constrain the simplest case in which a single compact axion descends from a gauge field in an extra dimension. We argue that the Weak Gravity Conjecture also constrains a variety of theories of multiple compact axions including N-flation and some alignment models. We show that other alignment models entail surprising consequences for how the mass spectrum of the theory varies across the axion moduli space, and hence can be excluded if further conjectures hold. In every case that we consider, plausible assumptions lead to field ranges that cannot be parametrically larger than M Pl . Our results are strongly suggestive of a general inconsistency in models of large-field inflation based on compact axions, and possibly of a more general principle forbidding super-Planckian field ranges.

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Section: Introductionmentioning

confidence: 76%

Section: Assessing Strong Conjecturesmentioning

confidence: 87%

Section: Wgc and Single-axion Inflation: Electric Argumentmentioning

confidence: 99%

Section: Case 1: Dominant Instantons Satisfy Electric Wgcmentioning

confidence: 99%

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Weak gravity strongly constrains large-field axion inflation

Heidenreich

Reece

Rudelius

2015

J. High Energ. Phys.

137

208

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“…Debe destacarse, asimismo, que los compuestos aquí determinados han sido señalados en diversas poblaciones de todo el mundo, incluyendo argentinas (RODRÍGUEZ, 1977;PICMAN & TOWERS, 1982). RODRÍGUEZ (1977) sugirió que la distribución ecogeográfica de los productos secundarios en Parthenium es probablemente resultado de una respuesta adaptativa por varios factores físicos y bióticos en el ambiente, una conclusión apoyada por estudios similares en las poblaciones por nosotros estudiadas (DE LA FUENTE & al., 1997). 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 4 4 4 …”

Section: Fitoquímicounclassified

Evaluation of the species boundaries between <i>Parthenium hysterophorus</i> and <i>P. glomeratum (Asteraceae-Ambrosiinae)</i>: morphological, anatomical, chromosomal and phytochemical evidence

Piazzano¹,

Bernardello²,

Novara³

et al. 1998

Anal. Jard. Bot. Madr.

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(1998). Evaluación de los limites específicos entre Parthenium hysterophorus y P. glomeratum (Asteraceae-Ambrosiinae): evidencias morfológicas, anatómicas, cromosomáticas y fitoquímicas. Anales Jard. Bot. Madrid 56(1): 65-76.Se evalúan los límites específicos del complejo Parthenium hysterophorum L./P. glomeratum Rollins con la hipótesis de que podría deberse a la disección de un "continuum", representado por una variación clinal en un gradiente altitudinal. Se escogió un gradiente entre 300-3500 m en Salta (Argentina). Se realizó un análisis numérico de coordenadas principales de la variabilidad exomorfológica, se hicieron estudios de anatomía foliar y caulinar, de números cromosomáticos y cariótipos y de lactonas sesquiterpénicas, y se efectuaron experiencias de trasplante. Los resultados indican que no se pueden delimitar grupos significativos sobre la base de los caracteres exomorfológicos y anatómicos. Los caracteres usados para diferenciar las especies están significativamente correlacionados con la altura sobre el mar a la que crecen estas plantas, señalando que se trata de una variación clinal. El experimento de trasplante evidencia que los mismos caracteres muestran una gran plasticidad fenotípica. Los datos citológicos y fitoquímicos indican gran polimorfismo en la población, no encontrándose discontinuidades que permitan separarla. Se considera conveniente tratar a los especímenes estudiados como coespecíficos y pertenecientes a P. hysterophorus, y a P. glomeratum como sinónimo.Palabras clave: Asteraceae, Parthenium hysterophorus, P. glomeratum, morfología, anatomía foliar y caulinar, números cromosomáticos, cariótipos, lactonas sesquiterpénicas, análisis numérico. Species boundaries between Parthenium hysterophorus L./P. glomeratum Rollins were examined. Our working hypothesis states that the delimitation of these taxa is based on the dissection of a continuous variation pattem from an elevational cline. We chose a 70 km gradient from 300-3500 m in the Province of Salta (Argentina) where both taxa are sympatric.

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ChemInform Abstract: Chemotaxonomy of Parthenium: P. hysterophorus—P. glomeratum.

et al. 1997

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Chemotaxonomy of Parthenium: P. hysterophorus-P. glomeratum. -From the aerial parts of five populations of P. hysterophorus and/or P. glomeratum growing in different geographical regions of Salta Province, Argentina, four new pseudoguaianolides (Ia) and (Ib) (4:1 mixture), (II) and (III) are isolated in addition to seven known sesquiterpene lactones. Taxonomic and photochemical studies result in the hypothesis that P. glomeratum could be an alpine form of P. hysterophorus. -(DE LA FUENTE, J. R.; NOVARA, L.; ALARCON, S. R.; DIAZ, O. J.; URIBURU, M. L.; SOSA, V. E.;

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Chemotaxonomy of Parthenium: P. Hysterophorus—P. Glomeratum

Cited by 25 publications

References 13 publications

Weak gravity strongly constrains large-field axion inflation

Weak gravity strongly constrains large-field axion inflation

Evaluation of the species boundaries between <i>Parthenium hysterophorus</i> and <i>P. glomeratum (Asteraceae-Ambrosiinae)</i>: morphological, anatomical, chromosomal and phytochemical evidence

ChemInform Abstract: Chemotaxonomy of Parthenium: P. hysterophorus—P. glomeratum.

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