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1.
Methods Mol Biol ; 2703: 131-160, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37646943

RESUMO

CromoCat is a plant chromosome database that evolved from previous versions, as a repository of karyological information on the vascular flora of the Catalan Countries. CromoCat is designed as an independent database, managed by a team based at the University of Barcelona directed by J. Simon, available from its own webpage ( http://www.cromo.cat/ ) and from the Flora section of the Catalan Biodiversity Database - BDBC ( http://biodiver.bio.ub.es ). CromoCat contains at present (mid 2022) more than 68,000 records of karyological data belonging to more than 5000 taxa. A synthesis of the development of CromoCat, its functional system, achievements, limitations, and adopted solutions, during 25 years (1996-2021) and updated 2022, as well as the application to biodiversity conservation and management are outlined.


Assuntos
Biodiversidade , Cromossomos de Plantas , Bases de Dados Factuais
2.
Methods Mol Biol ; 2703: 173-192, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37646945

RESUMO

An updated (and now online) version of the former chromosome database of tribe Delphinieae (Ranunculaceae) is presented ( http://www.delphinieae.online ). This new version is the result of an accurate, exhaustive literature and Internet research, by adding chromosome counts and all related karyological information for the genera Aconitum L., Gymnaconitum (Stapf) Wei Wang & Z. D. Chen, Delphinium L. (including Staphisagria Spach), Consolida (DC.) S. F. Gray and Aconitella Spach, accumulated during the approximately last 25 years and that comprise worldwide published data from 1889 to 2021. The Delphinieae Chromosome Database (DCDB) (last updated 31.12.2021) contains a total number of 3435 reports belonging to 425 species (503 taxa), which represents 48.6% of the total species of the tribe (an increase of c. 213% and 32% compared with the 1097 and 2598 reports gathered in the 1999 and 2016 versions, respectively). This increase is due both to chromosome research progress and to improved information capture system. Moreover, recent taxonomic advances, synonymization, and new phylogenetic criteria have also been considered.The DCDB database provides the most complete currently available information on published chromosome numbers, ploidy-level estimates, and other karyological data of Delphinieae, and it is aimed to be useful for the building of cytotaxonomical databases and for specific research ongoing projects of systematics and evolution of Ranunculaceae. DCDB includes two levels of taxonomic resolution, published name (original and standardized form) and database accepted name (based on either Plants of the World - POWO or expert specialist criteria), as well as the geographic origin of each count (country, locality, geographic coordinates, elevation, or ecological information when reported in the original publication), associated karyological data if originally provided (studied material type, graphic information, chromosome measures and formulas, satellites, B chromosomes, other cytogenetic techniques used, etc.), voucher information and reference (with DOI and other links to access the original document). An effort to check the original sources and to search in grey literature allowed to indicate the counts that appear to be registered twice.


Assuntos
Ranunculaceae , Filogenia , Análise Citogenética , Bases de Dados Factuais , Internet
3.
Methods Mol Biol ; 2703: 211-225, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37646948

RESUMO

Chromosome numbers have been used in plant taxonomy, and they are still fundamental for taxon delimitation and genome evolution studies. South America is one of the most diverse continents in terms of plant species and there is a considerable number of species not yet analyzed. Accumulated knowledge about plant chromosome numbers has been compiled from online databases, and here we present an overview. The CCDB is one of the largest plant cytological databases and includes data for around 18% of known vascular plants in the world. In this work, we review the information contained in CCDB and in three databases with exclusive information for South America. At present, the three existing databases comprise information on around 1800 plant taxa related to specific regions, countries, or biomes. Efforts are necessary to expand cytological knowledge and to collect all the available information in a plant chromosome database for this continent.


Assuntos
Cromossomos de Plantas , Traqueófitas , Cromossomos de Plantas/genética , Bases de Dados Factuais , Ecossistema , América do Sul
4.
Phys Rev Lett ; 123(8): 081601, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31491207

RESUMO

We investigate the variation of holographic complexity for two nearby target states. Based on Nielsen's geometric approach, we find the variation only depends on the end point of the optimal trajectory, a result which we designate the first law of complexity. As an example, we examine the complexity=action conjecture when the anti-de Sitter vacuum is perturbed by a scalar field excitation, which corresponds to a coherent state. Remarkably, the gravitational contributions completely cancel and the final variation reduces to a boundary term coming entirely from the scalar field action. Hence, the null boundary of Wheeler-DeWitt patch appears to act like the "end of the quantum circuit".

5.
Phys Rev Lett ; 111(18): 181301, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-24237503

RESUMO

Flat space cosmology spacetimes are exact time-dependent solutions of three-dimensional gravity theories, such as Einstein gravity or topologically massive gravity. We exhibit a novel kind of phase transition between these cosmological spacetimes and the Minkowski vacuum. At sufficiently high temperature, (rotating) hot flat space tunnels into a universe described by flat space cosmology.

6.
Phys Rev Lett ; 110(14): 141302, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-25166977

RESUMO

We provide a first derivation of the Bekenstein-Hawking entropy of 3D flat cosmological horizons in terms of the counting of states in a dual field theory. These horizons appear in the flat limit of nonextremal rotating Banados-Teitleboim-Zanelli black holes and are remnants of the inner horizons. They also satisfy the first law of thermodynamics. We study flat holography as a limit of AdS(3)/CFT(2) to semiclassically compute the density of states in the dual theory, which is given by a contraction of a 2D conformal field theory, exactly reproducing the bulk entropy in the limit of large charges. We comment on how the dual theory reproduces the bulk first law and how cosmological bulk excitations are matched with boundary quantum numbers.

7.
Living Rev Relativ ; 15(1): 3, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-28179834

RESUMO

This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green-Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds. Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol'nyi-Prasad-Sommerfield (BPS) states carrying (topological) charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT) correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description. Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern-Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations.

8.
Ann Bot ; 93(3): 323-32, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14742353

RESUMO

BACKGROUND AND AIMS: Thymus loscosii (Lamiaceae) is a tetraploid perennial species endemic to the Ebro river basin (north-eastern Spain), which is included in the National Catalogue of Endangered Species. It is a tetraploid species (2n = 54), presumably an autotetraploid originated by the duplication of a 2n = 28 genome and the subsequent loss of two chromosomes. Allozyme electrophoresis was conducted to survey the levels and distribution of genetic diversity and to test the previous autopolyploid hypothesis for its origin. In addition, both in situ and ex situ conservation measures are proposed. METHODS: Eight populations were sampled for analysis by standard methods of starch gel electrophoresis, and six putative enzymatic loci were resolved (five consistently and one only partially). KEY RESULTS: Banding patterns exhibited no evidence of fixed heterozygosity and showed both balanced and unbalanced heterozygotes. In addition, most individuals showed a pattern consistent with the presence of three or four alleles at a single locus. High levels of genetic variability were found at population level (P = 85 %, A = 3.0, He = 0.422), in addition to a trend of an excess of heterozygotes. CONCLUSIONS: Allozyme data support the hypothesis that T. loscosii is an autotetraploid, and the high number of alleles at some loci may be due to repeated polyploidization events. The high values of genetic variation found in this species agree with those expected for tetraploids. The excess of heterozygotes may be due to some barriers to inbreeding (e.g. occurrence of gynodioecy) and/or selection for heterozygosity.


Assuntos
Enzimas/genética , Variação Genética/genética , Lamiaceae/genética , Poliploidia , Eletroforese em Gel de Amido , Enzimas/metabolismo , Frequência do Gene , Heterozigoto , Lamiaceae/enzimologia , Polimorfismo Genético
9.
Phys Rev Lett ; 91(23): 231601, 2003 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-14683172

RESUMO

We demonstrate that certain supersymmetric Gödel-like universe solutions of supergravity are not solutions of string theory. This is achieved by realizing that supertubes are Bogomol'nyi-Prasad-Sommerfeld states in these spaces, and under certain conditions, when wrapping closed timelike curves, some world-volume modes develop negative kinetic terms. Since these universes are homogeneous, this instability takes place everywhere in space-time. We also construct a family of supergravity solutions which locally look like the Gödel universe inside a domain wall made out of supertubes, but have very different asymptotic structure. One can adjust the volume inside the domain wall so there will be no closed timelike curves, and then those spaces seem like perfectly good string backgrounds.

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