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Catanzaro A, Genco A, Louca C, Ruiz-Tijerina DA, Gillard DJ, Sortino L, Kozikov A, Alexeev EM, Pisoni R, Hague L, Watanabe K, Taniguchi T, Ensslin K, Novoselov KS, Fal'ko V, Tartakovskii AI. Resonant Band Hybridization in Alloyed Transition Metal Dichalcogenide Heterobilayers. Adv Mater 2024; 36:e2309644. [PMID: 38279553 DOI: 10.1002/adma.202309644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/20/2023] [Indexed: 01/28/2024]
Abstract
Bandstructure engineering using alloying is widely utilized for achieving optimized performance in modern semiconductor devices. While alloying has been studied in monolayer transition metal dichalcogenides, its application in van der Waals heterostructures built from atomically thin layers is largely unexplored. Here, heterobilayers made from monolayers of WSe2 (or MoSe2) and MoxW1 - xSe2 alloy are fabricated and nontrivial tuning of the resultant bandstructure is observed as a function of concentration x. This evolution is monitored by measuring the energy of photoluminescence (PL) of the interlayer exciton (IX) composed of an electron and hole residing in different monolayers. In MoxW1 - xSe2/WSe2, a strong IX energy shift of ≈100 meV is observed for x varied from 1 to 0.6. However, for x < 0.6 this shift saturates and the IX PL energy asymptotically approaches that of the indirect bandgap in bilayer WSe2. This observation is theoretically interpreted as the strong variation of the conduction band K valley for x > 0.6, with IX PL arising from the K - K transition, while for x < 0.6, the bandstructure hybridization becomes prevalent leading to the dominating momentum-indirect K - Q transition. This bandstructure hybridization is accompanied with strong modification of IX PL dynamics and nonlinear exciton properties. This work provides foundation for bandstructure engineering in van der Waals heterostructures highlighting the importance of hybridization effects and opening a way to devices with accurately tailored electronic properties.
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Affiliation(s)
- Alessandro Catanzaro
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
| | - Armando Genco
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milano, 20133, Italy
| | - Charalambos Louca
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milano, 20133, Italy
| | - David A Ruiz-Tijerina
- Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad de México, C.P., 04510, Mexico, México
| | - Daniel J Gillard
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
| | - Luca Sortino
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
- Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Aleksey Kozikov
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
- School of Mathematics, Statistics and Physics, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Evgeny M Alexeev
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
- Cambridge Graphene Centre, University of Cambridge, 9 J. J. Thomson Avenue, Cambridge, CB3 0FA, UK
| | - Riccardo Pisoni
- Solid State Physics Laboratory, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Lee Hague
- National Graphene Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Kenji Watanabe
- Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Klaus Ensslin
- Solid State Physics Laboratory, ETH Zurich, Zurich, CH-8093, Switzerland
| | - Kostya S Novoselov
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, 117546, Singapore
| | - Vladimir Fal'ko
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, M13 9PL, United Kingdom
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Martínez-Ruiz M, Arroyo-Rodríguez V, Arasa-Gisbert R, Hernández-Ruedas MA, San-José M. Maintenance of different life stages of old-growth forest trees in deforested tropical landscapes. Ecology 2024; 105:e4273. [PMID: 38361224 DOI: 10.1002/ecy.4273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/21/2023] [Accepted: 01/19/2024] [Indexed: 02/17/2024]
Abstract
Tropical tree species are increasingly being pushed to inhabit deforested landscapes. The habitat amount hypothesis posits that, in remaining forest patches, species diversity in equal-sized samples decreases with decreasing forest cover in the surrounding landscape. We tested this prediction by taking into account three important factors that can affect species responses to forest loss. First, forest loss effects can be linear (proportional) or nonlinear, as there can be threshold values of forest loss beyond which species extirpation may be accelerated. Second, such effects are usually scale dependent and may go unnoticed if assessed at suboptimal scales. Finally, species extirpation may take decades to become evident, so the effects of forest loss can be undetected when assessing long-lived organisms, like adult old-growth forest trees. Here, we evaluated the linear and nonlinear effects of landscape forest loss across different spatial scales on site-scale abundance and diversity of old-growth forest trees, separately for four plant-life stages (seeds, saplings, juveniles, and adults) in two rainforest regions with different levels of deforestation. We expected stronger (and negative) forest loss effects on early plant-life stages, especially in the region with the highest deforestation. Surprisingly, in 13 of 16 study cases (2 responses × 4 life stages × 2 regions), null models showed higher empirical support than linear and nonlinear models at any scale. Therefore, the species richness and abundance of local tree assemblages seem to be weakly affected by landscape-scale forest loss independently of the spatial scale, life stage, and region. Yet, as expected, the predictive power of forest cover was relatively lower in the least deforested region. Our findings suggest that landscape-scale forest loss is poorly related to site-scale processes, such as seed dispersal and seedling recruitment, or, at least, such effects are too small to shape the abundance and diversity of tree assemblages within forest patches. Therefore, our findings do not support the most important prediction of the habitat amount hypothesis but imply that, on a per-area basis, a unit of habitat (forest) in a highly deforested landscape has a conservation value similar to that of a more forested one, particularly in moderately deforested rainforests.
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Affiliation(s)
- Marisela Martínez-Ruiz
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Mérida, Mexico
| | - Víctor Arroyo-Rodríguez
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Mérida, Mexico
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, Morelia, Mexico
| | - Ricard Arasa-Gisbert
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | - Miriam San-José
- Charles Darwin Research Station, Charles Darwin Foundation, Galápagos, Ecuador
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Cano N, González-Jiménez JM, Camprubí A, Domínguez-Carretero D, González-Partida E, Proenza JA. Nanomaterial accumulation in boiling brines enhances epithermal bonanzas. Sci Rep 2023; 13:14985. [PMID: 37696864 PMCID: PMC10495403 DOI: 10.1038/s41598-023-41756-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/31/2023] [Indexed: 09/13/2023] Open
Abstract
Epithermal bonanza-type ores, characterized by weight-percent contents of e.g., gold and silver in a few mm to cm, are generated by mixtures of magmatic-derived hydrothermal brines and external fluids (e.g., meteoric) that transport a variety of metals to the site of deposition. However, the low solubilities of precious metals in hydrothermal fluids cannot justify the high concentrations necessary to produce such type of hyper-enriched metal ore. Here we show that boiling metal-bearing brines can produce, aggregate, and accumulate metal nanomaterials, ultimately leading to focused gold + silver ± copper over-enrichments. We found direct nano-scale evidence of nanoparticulate gold- and/or silver-bearing ores formed via nonclassical growth (i.e., nanomaterial attachment) during boiling in an intermediate-sulfidation epithermal bonanza. The documented processes may explain the generation of bonanzas in metal-rich brines from a range of mineral deposit types.
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Affiliation(s)
- Néstor Cano
- Programa de Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México (UNAM). Ciudad Universitaria, 04510, Coyoacán, CDMX, Mexico.
| | - José M González-Jiménez
- Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Avda. de Las Palmeras 4, 18100, Armilla, Granada, Spain
| | - Antoni Camprubí
- Instituto de Geología, UNAM. Ciudad Universitaria, 04510, Coyoacán, CDMX, Mexico
| | - Diego Domínguez-Carretero
- Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí I Franquès S/N, 08028, Barcelona, Spain
| | | | - Joaquín A Proenza
- Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí I Franquès S/N, 08028, Barcelona, Spain
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Villeda-Villegas M, Páez-Franco JC, Coyote-Dotor G, Núñez-Pineda A, Dorazco-González A, Fuentes-Noriega I, Rubio-Carrasco K, Toledo Jaldín HP, Morales-Morales D, Germán-Acacio JM. Diversity of Solid Forms Promoted by Ball Milling: Characterization and Intrinsic Dissolution Studies of Pioglitazone Hydrochloride and Fluvastatin Sodium Drug-Drug Systems. Pharmaceuticals (Basel) 2023; 16:781. [PMID: 37375729 DOI: 10.3390/ph16060781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 05/03/2023] [Accepted: 05/12/2023] [Indexed: 06/29/2023] Open
Abstract
Coamorphous salt in a 1:1 ratio prepared by ball milling from Fluvastatin sodium (FLV) and Pioglitazone hydrochloride (PGZ·HCl) can be selectively formed by neat grinding (NG). Furthermore, the salt-cocrystal continuum was preferably formed by employing liquid-assisted grinding (LAG) using ethanol (EtOH). Attempts to prepare the coamorphous salt starting from the salt-cocrystal continuum by NG were unsuccessful. Interestingly, through ball milling by NG or LAG, a great diversity of solid forms (PGZ·HCl-FLV 1:1) could be accessed: NG and hexane (coamorphous); ethyl acetate (physical mixture); EtOH (salt-cocrystal continuum); and water (which presents two Tg, indicating immiscibility of the components). An exploration was performed at different drug-to-drug ratios by NG. By differential scanning calorimetry (DSC), the presence of two endothermic events was observed in this screening: incongruous melting point (solidus) and excess of one of the components (liquidus), except in the 1:1 solid form. From these results, eutectic behavior was observed. Through the construction of a binary phase diagram, it was determined that the 1:1 molar ratio gives rise to the formation of the most stable coamorphous composition. Dissolution profile studies of these solid forms were carried out, specifically on pure FLV and the solid forms of PGZ⋅HCl-FLV (1:2; 1:4; and 1:6), together with the coamorphous 1:1 salt. By itself, pure FLV presented the highest Kint (13.6270 ± 0.8127 mg/cm2⋅min). On the other hand, the coamorphous 1:1 showed a very low Kint (0.0220 ± 0.0014 mg/cm2·min), indicating very fast recrystallization by the FLV, which avoids observing a sudden release of this drug in the solution. This same behavior was observed in the eutectic composition 1:2. In the other solid forms, the value of Kint increases along with the %w of FLV. From the mechanochemical point of view, ball milling by NG or LAG became an important synthetic tool since it allows obtaining a great variety of solid forms to explore the solid-state reactivity of the drug-drug solid-form PGZ HCl-FLV.
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Affiliation(s)
- Marco Villeda-Villegas
- Red de Apoyo a la Investigación, Coordinación de la Investigación Científica-UNAM, Instituto Nacional de Ciencias Médicas y Nutrición SZ, Ciudad de Mexico 14000, Mexico
| | - José C Páez-Franco
- Red de Apoyo a la Investigación, Coordinación de la Investigación Científica-UNAM, Instituto Nacional de Ciencias Médicas y Nutrición SZ, Ciudad de Mexico 14000, Mexico
| | - Guadalupe Coyote-Dotor
- Red de Apoyo a la Investigación, Coordinación de la Investigación Científica-UNAM, Instituto Nacional de Ciencias Médicas y Nutrición SZ, Ciudad de Mexico 14000, Mexico
| | - Alejandra Núñez-Pineda
- Centro Conjunto de Investigación en Química Sustentable CCIQS UAEM-UNAM Carretera Toluca-Atlacomulco km 14.5, Toluca 50200, Mexico
- Instituto de Química, Universidad Nacional Autónoma de Mexico, Circuito Exterior, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico
| | - Alejandro Dorazco-González
- Instituto de Química, Universidad Nacional Autónoma de Mexico, Circuito Exterior, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico
| | - Inés Fuentes-Noriega
- Laboratorio de Biofarmacia, Departamento de Farmacia, Facultad de Química-UNAM, Ciudad de México 04510, Mexico
| | - Kenneth Rubio-Carrasco
- Laboratorio de Biofarmacia, Departamento de Farmacia, Facultad de Química-UNAM, Ciudad de México 04510, Mexico
| | - Helen P Toledo Jaldín
- Technological Superior Studies Tianguistenco, Mechanical Engineering, Santiago Tianguistenco 52650, Mexico
| | - David Morales-Morales
- Instituto de Química, Universidad Nacional Autónoma de Mexico, Circuito Exterior, Ciudad Universitaria, Ciudad de Mexico 04510, Mexico
| | - Juan Manuel Germán-Acacio
- Red de Apoyo a la Investigación, Coordinación de la Investigación Científica-UNAM, Instituto Nacional de Ciencias Médicas y Nutrición SZ, Ciudad de Mexico 14000, Mexico
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Guzmán-Solís AA, Villa-Islas V, Bravo-López MJ, Sandoval-Velasco M, Wesp JK, Gómez-Valdés JA, Moreno-Cabrera MDLL, Meraz A, Solís-Pichardo G, Schaaf P, TenOever BR, Blanco-Melo D, Ávila Arcos MC. Ancient viral genomes reveal introduction of human pathogenic viruses into Mexico during the transatlantic slave trade. eLife 2021; 10:e68612. [PMID: 34350829 PMCID: PMC8423449 DOI: 10.7554/elife.68612] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 07/30/2021] [Indexed: 02/06/2023] Open
Abstract
After the European colonization of the Americas, there was a dramatic population collapse of the Indigenous inhabitants caused in part by the introduction of new pathogens. Although there is much speculation on the etiology of the Colonial epidemics, direct evidence for the presence of specific viruses during the Colonial era is lacking. To uncover the diversity of viral pathogens during this period, we designed an enrichment assay targeting ancient DNA (aDNA) from viruses of clinical importance and applied it to DNA extracts from individuals found in a Colonial hospital and a Colonial chapel (16th-18th century) where records suggest that victims of epidemics were buried during important outbreaks in Mexico City. This allowed us to reconstruct three ancient human parvovirus B19 genomes and one ancient human hepatitis B virus genome from distinct individuals. The viral genomes are similar to African strains, consistent with the inferred morphological and genetic African ancestry of the hosts as well as with the isotopic analysis of the human remains, suggesting an origin on the African continent. This study provides direct molecular evidence of ancient viruses being transported to the Americas during the transatlantic slave trade and their subsequent introduction to New Spain. Altogether, our observations enrich the discussion about the etiology of infectious diseases during the Colonial period in Mexico.
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Affiliation(s)
- Axel A Guzmán-Solís
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de MéxicoQuerétaroMexico
| | - Viridiana Villa-Islas
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de MéxicoQuerétaroMexico
| | - Miriam J Bravo-López
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de MéxicoQuerétaroMexico
| | - Marcela Sandoval-Velasco
- Section for Evolutionary Genomics, The Globe Institute, Faculty of Health, University of CopenhagenCopenhagenDenmark
| | - Julie K Wesp
- Department of Sociology and Anthropology, North Carolina State UniversityRaleighUnited States
| | | | | | - Alejandro Meraz
- Instituto Nacional de Antropología e HistoriaMexico CityMexico
| | - Gabriela Solís-Pichardo
- Laboratorio Universitario de Geoquímica Isotópica (LUGIS), Instituto de Geología, Universidad Nacional Autónoma de MéxicoMexico CityMexico
| | - Peter Schaaf
- LUGIS, Instituto de Geofísica, Universidad Nacional Autónoma de MéxicoMexico CityMexico
| | - Benjamin R TenOever
- Department of Microbiology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Daniel Blanco-Melo
- Department of Microbiology, Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research CenterSeattle, WAUnited States
| | - María C Ávila Arcos
- Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de MéxicoQuerétaroMexico
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Ramos CH, Rodríguez-Sánchez E, Del Angel JAA, Arzola AV, Benítez M, Escalante AE, Franci A, Volpe G, Rivera-Yoshida N. The environment topography alters the way to multicellularity in Myxococcus xanthus. Sci Adv 2021; 7:7/35/eabh2278. [PMID: 34433567 PMCID: PMC8386931 DOI: 10.1126/sciadv.abh2278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/02/2021] [Indexed: 05/10/2023]
Abstract
The social soil-dwelling bacterium Myxococcus xanthus can form multicellular structures, known as fruiting bodies. Experiments in homogeneous environments have shown that this process is affected by the physicochemical properties of the substrate, but they have largely neglected the role of complex topographies. We experimentally demonstrate that the topography alters single-cell motility and multicellular organization in M. xanthus In topographies realized by randomly placing silica particles over agar plates, we observe that the cells' interaction with particles drastically modifies the dynamics of cellular aggregation, leading to changes in the number, size, and shape of the fruiting bodies and even to arresting their formation in certain conditions. We further explore this type of cell-particle interaction in a computational model. These results provide fundamental insights into how the environment topography influences the emergence of complex multicellular structures from single cells, which is a fundamental problem of biological, ecological, and medical relevance.
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Affiliation(s)
- Corina H Ramos
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. de México, C.P. 4510, Mexico
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Edna Rodríguez-Sánchez
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Juan Antonio Arias Del Angel
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Alejandro V Arzola
- Instituto de Física, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, México
| | - Mariana Benítez
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Ana E Escalante
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
| | - Alessio Franci
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. de México, C.P. 4510, Mexico
| | - Giovanni Volpe
- Department of Physics, University of Gothenburg, Gothenburg, Sweden
| | - Natsuko Rivera-Yoshida
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Cd. de México, C.P. 4510, Mexico.
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Cd. de México, C.P. 04510, Mexico
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Rosas-Reinhold I, Piñeyro-Nelson A, Rosas U, Arias S. Blurring the Boundaries between a Branch and a Flower: Potential Developmental Venues in CACTACEAE. Plants (Basel) 2021; 10:1134. [PMID: 34204904 PMCID: PMC8228900 DOI: 10.3390/plants10061134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/28/2021] [Accepted: 06/01/2021] [Indexed: 11/16/2022]
Abstract
Flowers are defined as short shoots that carry reproductive organs. In Cactaceae, this term acquires another meaning, since the flower is interpreted as a branch with a perianth at the tip, with all reproductive organs embedded within the branch, thus giving way to a structure that has been called a "flower shoot". These organs have long attracted the attention of botanists and cactologists; however, the understanding of the morphogenetic processes during the development of these structures is far from clear. In this review, we present and discuss some classic flower concepts used to define floral structures in Cactaceae in the context of current advances in flower developmental genetics and evolution. Finally, we propose several hypotheses to explain the origin of these floral shoot structures in cacti, and we suggest future research approaches and methods that could be used to fill the gaps in our knowledge regarding the ontogenetic origin of the "flower" in the cactus family.
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Affiliation(s)
- Isaura Rosas-Reinhold
- Instituto de Biología, Jardín Botánico, Universidad Nacional Autónoma de México, Ciudad de México C.P.04510, Mexico; (I.R.-R.); (U.R.)
- Posgrado en Ciencias Biológicas, Instituto de Biología, Universidad Nacional Autónoma de México, A. P. 70-153, Ciudad de México C.P.04510, Mexico
| | - Alma Piñeyro-Nelson
- Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana-Xochimilco, Ciudad de México C.P.04510, Mexico;
- Centro de Ciencias de la Complejidad (C3), Universidad Nacional Autónoma de México, Ciudad de México C.P.04960, Mexico
| | - Ulises Rosas
- Instituto de Biología, Jardín Botánico, Universidad Nacional Autónoma de México, Ciudad de México C.P.04510, Mexico; (I.R.-R.); (U.R.)
| | - Salvador Arias
- Instituto de Biología, Jardín Botánico, Universidad Nacional Autónoma de México, Ciudad de México C.P.04510, Mexico; (I.R.-R.); (U.R.)
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Cuervo-Robayo AP, Ureta C, Gómez-Albores MA, Meneses-Mosquera AK, Téllez-Valdés O, Martínez-Meyer E. One hundred years of climate change in Mexico. PLoS One 2020; 15:e0209808. [PMID: 32673306 PMCID: PMC7365465 DOI: 10.1371/journal.pone.0209808] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 06/19/2020] [Indexed: 11/18/2022] Open
Abstract
Spatial assessments of historical climate change provide information that can be used by scientists to analyze climate variation over time and evaluate, for example, its effects on biodiversity, in order to focus their research and conservation efforts. Despite the fact that there are global climatic databases available at high spatial resolution, they represent a short temporal window that impedes evaluating historical changes of climate and their impacts on biodiversity. To fill this gap, we developed climate gridded surfaces for Mexico for three periods that cover most of the 20th and early 21st centuries: t1-1940 (1910–1949), t2-1970 (1950–1979) and t3-2000 (1980–2009), and used these interpolated surfaces to describe how climate has changed over time, both countrywide and in its 19 biogeographic provinces. Results from our characterization of climate change indicate that the mean annual temperature has increased by nearly 0.2°C on average across the whole country from t2-1970 to t3-2000. However, changes have not been spatially uniform: Nearctic provinces in the north have suffered higher temperature increases than southern tropical regions. Central and southern provinces cooled at the beginning of the 20th century but warmed consistently since the 1970s. Precipitation increased between t1-1940 and t2-1970 across the country, more notably in the northern provinces, and it decreased between t2-1970 and t3-2000 in most of the country. Results on the historical climate conditions in Mexico may be useful for climate change analyses for both environmental and social sciences. Nonetheless, our climatology was based on information from climate stations for which 9.4–36.2% presented inhomogeneities over time probably owing to non-climatic factors, and climate station density changed over time. Therefore, the estimated changes observed in our analysis need to be interpreted cautiously.
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Affiliation(s)
- Angela P. Cuervo-Robayo
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México
- Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (Conabio), Ciudad de México, México
| | - Carolina Ureta
- Cátedras-Departamento de Ciencias Atmosféricas, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Miguel A. Gómez-Albores
- Instituto Interamericano de Tecnología y Ciencias del Agua, Universidad Autónoma del Estado de México, Toluca, Estado de México, México
| | - Anny K. Meneses-Mosquera
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Oswaldo Téllez-Valdés
- Facultad de Estudios Superiores Iztacala, Unidad de Biotecnología y Prototipos, Laboratorio de Recursos Naturales, Universidad Nacional Autónoma de México, Tlalnepantla, México
| | - Enrique Martínez-Meyer
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, México
- * E-mail:
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Sanchez-Sandoval AL, Herrera Carrillo Z, Díaz Velásquez CE, Delgadillo DM, Rivera HM, Gomora JC. Contribution of S4 segments and S4-S5 linkers to the low-voltage activation properties of T-type CaV3.3 channels. PLoS One 2018; 13:e0193490. [PMID: 29474447 PMCID: PMC5825144 DOI: 10.1371/journal.pone.0193490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 02/12/2018] [Indexed: 11/25/2022] Open
Abstract
Voltage-gated calcium channels contain four highly conserved transmembrane helices known as S4 segments that exhibit a positively charged residue every third position, and play the role of voltage sensing. Nonetheless, the activation range between high-voltage (HVA) and low-voltage (LVA) activated calcium channels is around 30–40 mV apart, despite the high level of amino acid similarity within their S4 segments. To investigate the contribution of S4 voltage sensors for the low-voltage activation characteristics of CaV3.3 channels we constructed chimeras by swapping S4 segments between this LVA channel and the HVA CaV1.2 channel. The substitution of S4 segment of Domain II in CaV3.3 by that of CaV1.2 (chimera IIS4C) induced a ~35 mV shift in the voltage-dependence of activation towards positive potentials, showing an I-V curve that almost overlaps with that of CaV1.2 channel. This HVA behavior induced by IIS4C chimera was accompanied by a 2-fold decrease in the voltage-dependence of channel gating. The IVS4 segment had also a strong effect in the voltage sensing of activation, while substitution of segments IS4 and IIIS4 moved the activation curve of CaV3.3 to more negative potentials. Swapping of IIS4 voltage sensor influenced additional properties of this channel such as steady-state inactivation, current decay, and deactivation. Notably, Domain I voltage sensor played a major role in preventing CaV3.3 channels to inactivate from closed states at extreme hyperpolarized potentials. Finally, site-directed mutagenesis in the CaV3.3 channel revealed a partial contribution of the S4-S5 linker of Domain II to LVA behavior, with synergic effects observed in double and triple mutations. These findings indicate that IIS4 and, to a lesser degree IVS4, voltage sensors are crucial in determining the LVA properties of CaV3.3 channels, although the accomplishment of this function involves the participation of other structural elements like S4-S5 linkers.
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Affiliation(s)
- Ana Laura Sanchez-Sandoval
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
| | - Zazil Herrera Carrillo
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
| | - Clara Estela Díaz Velásquez
- Programa de Neurociencias, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla de Baz, Estado de México, México
| | - Dulce María Delgadillo
- Laboratorios Nacionales de Servicios Experimentales Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, México
| | - Heriberto Manuel Rivera
- Facultad de Medicina, Universidad Autónoma del Estado de Morelos Cuernavaca, Morelos, México
| | - Juan Carlos Gomora
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México Mexico City, México
- * E-mail:
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