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123 results on '"POVEDA, L. A."'

1. Putative signals of generalist plant species adaptation to local pollinator communities and abiotic factors

Author

Frachon, Léa; https://orcid.org/0000-0001-8990-1419, Arrigo, Luca, Rusman, Quint, Poveda, L, Qi, W; https://orcid.org/0000-0001-8581-908X, Scopece, G; https://orcid.org/0000-0003-0341-6231, Schiestl, Florian P; https://orcid.org/0000-0001-7637-6918, Frachon, Léa; https://orcid.org/0000-0001-8990-1419, Arrigo, Luca, Rusman, Quint, Poveda, L, Qi, W; https://orcid.org/0000-0001-8581-908X, Scopece, G; https://orcid.org/0000-0003-0341-6231, and Schiestl, Florian P; https://orcid.org/0000-0001-7637-6918

Abstract

The reproductive success of flowering plants with generalized pollination systems is influenced by the interactions with a diverse pollinator community and abiotic factors. However, knowledge about the adaptative potential of plants to complex ecological networks and the underlying genetic mechanisms is still limited. Based on a pool-sequencing approach of 21 natural populations of Brassica incana in Southern Italy, we combined a genome-environmental association analysis with a genome scan for signals of population genomic differentiation to discover genetic variants associated with ecological variation. We identified genomic regions putatively involved in the adaptation of B. incana to the identity of local pollinator functional categories and pollinator community composition. Interestingly, we observed several shared candidate genes associated with long-tongue bees, soil texture, and temperature variation. We established a genomic map of potential generalist flowering plant local adaptation to complex biotic interactions, and the importance of considering multiple environmental factors to describe the adaptive landscape of plant populations.

Published
2023

2. Putative signals of generalist plant species adaptation to local pollinator communities and abiotic factors

Author

Frachon, Léa, Arrigo, Luca, Rusman, Quint, Poveda, L, Qi, W, Scopece, G, Schiestl, Florian P, and University of Zurich

Subjects
Brassica incana, generalist-pollinated plant species, local adaptation, natural populations, plant-pollinator interactions, genome-environmental association, 10121 Department of Systematic and Evolutionary Botany, Genetics, 580 Plants (Botany), 10211 Zurich-Basel Plant Science Center, Molecular Biology, Ecology, Evolution, Behavior and Systematics
Abstract

The reproductive success of flowering plants with generalized pollination systems is influenced by interactions with a diverse pollinator community and abiotic factors. However, knowledge about the adaptative potential of plants to complex ecological networks and the underlying genetic mechanisms is still limited. Based on a pool-sequencing approach of 21 natural populations of Brassica incana in Southern Italy, we combined a genome-environmental association analysis with a genome scan for signals of population genomic differentiation to discover genetic variants associated with the ecological variation. We identified genomic regions putatively involved in the adaptation of B. incana to the identity of local pollinator functional categories and pollinator community composition. Interestingly, we observed several shared candidate genes associated with long-tongue bees, soil texture, and temperature variation. We established a genomic map of potential generalist flowering plant local adaptation to complex biotic interactions, and the importance of considering multiple environmental factors to describe the adaptive landscape of plant populations., Molecular Biology and Evolution, 40 (3), ISSN:0737-4038, ISSN:1537-1719

Published
2023
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17. The effect of intersystem crossings in N(²D) + H2 collisions.

Author

Galvão, B. R. L. and Poveda, L. A.

Subjects
*INTERSYSTEM crossing (Chemistry), *NITROGEN, *HYDROGEN, *COLLISIONS (Physics), *PHASE transitions, *SPIN-orbit interactions
Abstract

The transitions between quartet and doublet states of the NH² molecule are studied for the first time, allowing the evaluation of the N(4S) + H2 reactive channel. High level ab initio calculations of the spin-orbit coupling are performed over the whole configurational space of the NH2 molecule and fitted to a proposed analytic form. Quasiclassical trajectories coupled with the surface hopping method are employed to calculate reaction cross section and rate constants. The reaction is largely affected by the initial rovibrational states of H2, while the formation of long-lived complexes enhances the reaction probability. [ABSTRACT FROM AUTHOR]

Published
2015
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19. Accurate ab initio based DMBE potential energy surface for the ground electronic state of N2H2.

Author

Poveda, L. A., Biczysko, M., and Varandas, A. J. C.

Subjects
*POTENTIAL energy surfaces, *QUANTUM chemistry, *DISSOCIATION (Chemistry), *GEOMETRIC modeling, *VARIATIONAL inequalities (Mathematics), *AZODICARBONAMIDE
Abstract

A global single-sheeted double many-body expansion potential energy surface is reported for the ground electronic state of N2H2. Starting from an approximate cluster expansion of the molecular potential that utilizes previously reported functions of the same family for the triatomic fragments, four-body energy terms have been calibrated from extensive accurate ab initio data so as to reproduce the main features of the title system. The switching function formalism previously suggested for three-body systems [A. J. C. Varandas and L. Poveda, Theor. Chem. Acc. 116, 404 (2006)] has been generalized to approximate the true multisheeted nature of N2H2 potential energy surface, thus allowing the correct behavior at the N(2D)+NH2(2A″) and N(4S)+NH2(4A″) dissociation limits. The resulting fully six-dimensional potential energy function reproduces the correct symmetry under permutation of identical atoms and predicts the main stationary points of the molecule in the valence and long-range regions in good agreement with available experimental and theoretical data on the diazene molecule. [ABSTRACT FROM AUTHOR]

Published
2009
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20. Accurate ab initio based DMBE potential energy surface for the ground electronic state of N2H2.

Author

Poveda, L. A., Biczysko, M., and Varandas, A. J. C.

Subjects
POTENTIAL energy surfaces, QUANTUM chemistry, DISSOCIATION (Chemistry), GEOMETRIC modeling, VARIATIONAL inequalities (Mathematics), AZODICARBONAMIDE
Abstract

A global single-sheeted double many-body expansion potential energy surface is reported for the ground electronic state of N2H2. Starting from an approximate cluster expansion of the molecular potential that utilizes previously reported functions of the same family for the triatomic fragments, four-body energy terms have been calibrated from extensive accurate ab initio data so as to reproduce the main features of the title system. The switching function formalism previously suggested for three-body systems [A. J. C. Varandas and L. Poveda, Theor. Chem. Acc. 116, 404 (2006)] has been generalized to approximate the true multisheeted nature of N2H2 potential energy surface, thus allowing the correct behavior at the N(2D)+NH2(2A″) and N(4S)+NH2(4A″) dissociation limits. The resulting fully six-dimensional potential energy function reproduces the correct symmetry under permutation of identical atoms and predicts the main stationary points of the molecule in the valence and long-range regions in good agreement with available experimental and theoretical data on the diazene molecule. [ABSTRACT FROM AUTHOR]

Published
2009
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21. Trabajo de Investigaci?n previo a la obtenci?n del T?tulo de Mag?ster en Ciencias de la Educaci?n, Menci?n: Educaci?n Parvularia

Author

Poveda L?pez, Monserrath Aracely and N??ez Espinoza, Marcelo Wilfrido

Subjects
familia, rendimiento escolar, personalidad, Afectividad
Abstract

El prop?sito de la presente investigaci?n es el proponer a los docentes del C.E.I Hogar ?Santa Marianita?, involucrarse m?s en lo personal con cada uno de los ni?os y ni?as ya que existen un nivel prudencial de ni?os/as sin afectividad familiar nula por lo que la familia adopta diferentes pautas o formas de vida que son transmitidos a sus miembros que determinan o ayudan a formar la personalidad de cada uno, en este caso la respuesta de un infante sin hogar o de un hogar con una a afectividad familiar distorsionada es el motivo para que tenga un bajo rendimiento escolar y con una conducta diferenciada. Este estudio pretende establecer y mejorar la realidad en la que se encuentren rodeados muchos estudiantes del plantel como punto de inicio para establecer situaciones de afectividad as?a los dem?s, ideales a las que se desea llegar; constituye en ejercicio de motivaci?n pr?cticos y estrategias metodol?gicas de orientaci?n familiar y de afectividad a s? mismo. De acuerdo a numerosos autores y a nuestras propias experiencias podemos afirmar axiom?ticamente que el alumno que rinde adecuadamente tendr? una opini?n positiva de s? mismo y de su capacidad como estudiante. En esta investigaci?n se utiliza la t?cnica de la encuesta para un mejor proceso, adem?s en el marco te?rico se ha recopilado informaci?n actualizada que gu?a eficientemente el desarrollo de la tem?tica propuesta y sirve de fuente de consulta a quien se interese sobre el tema.

Published
2016

23. Asymptotic expansions for high-contrast linear elasticity

Author

Poveda, L., Huepo, S., Calo, Victor, Galvis, J., Poveda, L., Huepo, S., Calo, Victor, and Galvis, J.

Abstract

We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm.

Published
2016

24. Green plants in the red: A baseline global assessment for the IUCN Sampled Red List Index for Plants

Author

Brummitt, N, Bachman, S, Griffiths-lee, J, Lutz, M, Moat, J, Farjon, A, Donaldson, J, Hilton-taylor, C, Meagher, T, Albuquerque, S, Aletrari, E, Andrews, A, Atchison, G, Baloch, E, Barlozzini, B, Brunazzi, A, Carretero, J, Celesti, M, Chadburn, H, Cianfoni, E, Cockel, C, Coldwell, V, Concetti, B, Contu, S, Crook, V, Dyson, P, Gardiner, L, Ghanim, N, Greene, H, Groom, A, Harker, R, Hopkins, D, Khela, S, Lakeman-fraser, P, Lindon, H, Lockwood, H, Loftus, C, Lombrici, D, Lopez-poveda, L, Lyon, J, Malcolm-tompkins, P, Mcgregor, K, Moreno, L, Murray, L, Nazar, K, Power, E, Quiton Tuijtelaars, M, Salter, R, Segrott, R, Thacker, H, Thomas, L, Tingvoll, S, Watkinson, G, Wojtaszekova, K, Nic Lughadha, E, Brummitt, Neil A, Bachman, Steven P, Griffiths-lee, Janine, Lutz, Maiko, Moat, Justin F, Farjon, Aljos, Donaldson, John S, Hilton-taylor, Craig, Meagher, Thomas R, Albuquerque, Sara, Aletrari, Elina, Andrews, A. Kei, Atchison, Guy, Baloch, Elisabeth, Barlozzini, Barbara, Brunazzi, Alice, Carretero, Julia, Celesti, Marco, Chadburn, Helen, Cianfoni, Eduardo, Cockel, Chris, Coldwell, Vanessa, Concetti, Benedetta, Contu, Sara, Crook, Vicki, Dyson, Philippa, Gardiner, Lauren, Ghanim, Nadia, Greene, Hannah, Groom, Alice, Harker, Ruth, Hopkins, Della, Khela, Sonia, Lakeman-fraser, Poppy, Lindon, Heather, Lockwood, Helen, Loftus, Christine, Lombrici, Debora, Lopez-poveda, Lucia, Lyon, James, Malcolm-tompkins, Patricia, Mcgregor, Kirsty, Moreno, Laura, Murray, Linda, Nazar, Keara, Power, Emily, Quiton Tuijtelaars, Mireya, Salter, Ruth, Segrott, Robert, Thacker, Hannah, Thomas, Leighton J, Tingvoll, Sarah, Watkinson, Gemma, Wojtaszekova, Katerina, Nic Lughadha, Eimear M., Brummitt, N, Bachman, S, Griffiths-lee, J, Lutz, M, Moat, J, Farjon, A, Donaldson, J, Hilton-taylor, C, Meagher, T, Albuquerque, S, Aletrari, E, Andrews, A, Atchison, G, Baloch, E, Barlozzini, B, Brunazzi, A, Carretero, J, Celesti, M, Chadburn, H, Cianfoni, E, Cockel, C, Coldwell, V, Concetti, B, Contu, S, Crook, V, Dyson, P, Gardiner, L, Ghanim, N, Greene, H, Groom, A, Harker, R, Hopkins, D, Khela, S, Lakeman-fraser, P, Lindon, H, Lockwood, H, Loftus, C, Lombrici, D, Lopez-poveda, L, Lyon, J, Malcolm-tompkins, P, Mcgregor, K, Moreno, L, Murray, L, Nazar, K, Power, E, Quiton Tuijtelaars, M, Salter, R, Segrott, R, Thacker, H, Thomas, L, Tingvoll, S, Watkinson, G, Wojtaszekova, K, Nic Lughadha, E, Brummitt, Neil A, Bachman, Steven P, Griffiths-lee, Janine, Lutz, Maiko, Moat, Justin F, Farjon, Aljos, Donaldson, John S, Hilton-taylor, Craig, Meagher, Thomas R, Albuquerque, Sara, Aletrari, Elina, Andrews, A. Kei, Atchison, Guy, Baloch, Elisabeth, Barlozzini, Barbara, Brunazzi, Alice, Carretero, Julia, Celesti, Marco, Chadburn, Helen, Cianfoni, Eduardo, Cockel, Chris, Coldwell, Vanessa, Concetti, Benedetta, Contu, Sara, Crook, Vicki, Dyson, Philippa, Gardiner, Lauren, Ghanim, Nadia, Greene, Hannah, Groom, Alice, Harker, Ruth, Hopkins, Della, Khela, Sonia, Lakeman-fraser, Poppy, Lindon, Heather, Lockwood, Helen, Loftus, Christine, Lombrici, Debora, Lopez-poveda, Lucia, Lyon, James, Malcolm-tompkins, Patricia, Mcgregor, Kirsty, Moreno, Laura, Murray, Linda, Nazar, Keara, Power, Emily, Quiton Tuijtelaars, Mireya, Salter, Ruth, Segrott, Robert, Thacker, Hannah, Thomas, Leighton J, Tingvoll, Sarah, Watkinson, Gemma, Wojtaszekova, Katerina, and Nic Lughadha, Eimear M.

Abstract

Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question 'How threatened are plants?' is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world's plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed.

Published
2015

28. Nuevas lactonas sesquiterpénicas de Perymenium grande

Author

Murillo, R., Castro, V., Araya, J., and Poveda, L.

Abstract

Three new sesquiterpenes lactonaes were isolated from the aerial parts of Perymenium grande Hemsl. (Asteraceae), collected around Rincón de la Vieja Volcano, Costa Rica. In addition to the three new lactones 1, 3 and 5; were isolated the additional five known sesquiterpenes lactones. The separation were performed with chromatographic techniques and the structures were elucidated by one- and two-dimensional nuclear magnetic resonance techniques.

Published
2009

29. Lignanos de Zanthoxylum acuminatum

Author

Murillo, R., Castro, V., Chavarría, M., and Poveda, L.

Abstract

From the aerial parts of Zanthoxylum acuminatum (Rutaceae) collected in Upala, Alajuela, Costa Rica were isolated the known lignans hinokinin, (+)-asarinin, (+)- piperitol, (+)-kobusin, and epi-kobusin. In addition to the lignans were isolated the triterpen lupeol and the steroid campesterol. All the separations were performed with chromatographic techniques and the structures were elucidated using 1D and 2D NMR techniques.

Published
2009

35. Antifeedant activities of terpenoids isolated from tropical Rutales

Author

Omar, S., primary, Marcotte, M., additional, Fields, P., additional, Sanchez, P.E., additional, Poveda, L., additional, Mata, R., additional, Jimenez, A., additional, Durst, T., additional, Zhang, J., additional, MacKinnon, S., additional, Leaman, D., additional, Arnason, J.T., additional, and Philogène, B.J.R., additional

Published
2007
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40. Traditionally-Used Antimalarials from the Meliaceae

Author

Omar, S., primary, Zhang, J., additional, MacKinnon, S., additional, Leaman, D., additional, Durst, T., additional, Philogene, B., additional, Arnason, J., additional, Sanchez-Vindas, P., additional, Poveda, L., additional, Tamez, P., additional, and Pezzuto, J., additional

Published
2003
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50. Insecticidal Neolignans from Piper decurrens

Author

Chauret, Denise C., primary, Bernard, Claude B., additional, Arnason, John T., additional, Durst, Tony, additional, Krishnamurty, H. G., additional, Sanchez-Vindas, Pablo, additional, Moreno, Nestor, additional, San Roman, L., additional, and Poveda, L., additional

Published
1996
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