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Institution

National University of La Plata

EducationLa Plata, Argentina
About: National University of La Plata is a education organization based out in La Plata, Argentina. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 12993 authors who have published 30013 publications receiving 495118 citations. The organization is also known as: UNLP & Universidad Nacional de La Plata.


Papers
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Journal ArticleDOI
05 Jun 2008-Nature
TL;DR: This method accounts for the quantitative nature of the traits, and respects their morphological integration patterns, and shows that when continuous, multivariant and modularized characters are treated as such, cladistic analysis successfully solves relationships among main Homo taxa.
Abstract: Cladistics, an analytical approach to constructing evolutionary family trees, revolutionized evolutionary theory in the 1970s. Critics, though, had a valid complaint. By breaking up evolutionary features or characters into the discrete states required for computational analysis, researchers might be distorting continuously variable characters. For example human fossil skulls might be classified as either 'flat-faced' or 'protruding-faced', when in reality these traits vary continuously. Gonzalez-Jose et al. circumvent these problems with a new approach that captures large-scale, biologically meaningful shape variation, treats the data using conventional statistics and uses the output to inform a cladistic analysis. Their test case, the Homo lineage, could provide a benchmark for future studies of the evolutionary relationships of groups in which there are many similar members. Their results support the firmly established relationships between Homo species and add some interesting detail, for instance placing Australopithecus africanus as a sister group to Homo. This paper adopts a new approach to phylogenetic analysis that captures large-scale, biologically meaningful shape variation, treats the data using conventional statistical approaches and uses the output to inform a cladistic analysis. Their test case, applied to the human lineage, could provide a benchmark for future studies of the evolutionary relationships of groups in which there are many similar members. Evolutionary novelties in the skeleton are usually expressed as changes in the timing of growth of features intrinsically integrated at different hierarchical levels of development1. As a consequence, most of the shape-traits observed across species do vary quantitatively rather than qualitatively2, in a multivariate space3 and in a modularized way4,5. Because most phylogenetic analyses normally use discrete, hypothetically independent characters6, previous attempts have disregarded the phylogenetic signals potentially enclosed in the shape of morphological structures. When analysing low taxonomic levels, where most variation is quantitative in nature, solving basic requirements like the choice of characters and the capacity of using continuous, integrated traits is of crucial importance in recovering wider phylogenetic information. This is particularly relevant when analysing extinct lineages, where available data are limited to fossilized structures. Here we show that when continuous, multivariant and modularized characters are treated as such, cladistic analysis successfully solves relationships among main Homo taxa. Our attempt is based on a combination of cladistics, evolutionary-development-derived selection of characters, and geometric morphometrics methods. In contrast with previous cladistic analyses of hominid phylogeny, our method accounts for the quantitative nature of the traits, and respects their morphological integration patterns. Because complex phenotypes are observable across different taxonomic groups and are potentially informative about phylogenetic relationships, future analyses should point strongly to the incorporation of these types of trait.

114 citations

Journal ArticleDOI
TL;DR: In this article, a study of the properties of the noise components and quasi-periodic oscillations (QPOs) as a function of the broadband spectral properties was performed, with the main goal to study the relation between the frequencies of the horizontal branch (HBO) and upper kHz QPOs.
Abstract: We have analyzed ~600 ks of Rossi X-Ray Timing Explorer data of the neutron star low-mass X-ray binary and Z source GX 17+2. A study was performed of the properties of the noise components and quasi-periodic oscillations (QPOs) as a function of the broadband spectral properties, with the main goal to study the relation between the frequencies of the horizontal branch (HBO) and upper kHz QPOs. It was found that when the upper kHz QPO frequency is below 1030 Hz these frequencies correlate, whereas above 1030 Hz they anticorrelate. GX 17+2 is the first source in which this is observed. We also found that the frequency difference of the high-frequency QPOs was not constant and that the quality factors (Q-values) of the HBO, its second harmonic, and the kHz QPOs are similar and vary almost hand in hand by a factor of more than 3. Observations of the normal branch oscillations during two type I X-ray bursts showed that their absolute amplitude decreased as the flux from the neutron star became stronger. We discuss these and other findings in terms of models that have been proposed for these phenomena. We also compare the behavior of GX 17+2 and other Z sources with that of black hole sources and consider the possibility that the mass accretion rate might not be the driving force behind all spectral and variability changes.

114 citations

Journal ArticleDOI
TL;DR: The degree of information provided by SNPs for a consanguineous herd of cattle was compared with that provided by STRs and it was shown that 24 SNPs were equivalent to the ISAG minimal recommended set of 12 STRs.
Abstract: Fil: Fernandez, Maria Elena Consejo Nacional de Investigaciones Cientificas y Tecnicas Centro Cientifico Tecnologico La Plata Instituto de Genetica Veterinaria "Ingeniero Fernando Noel Dulout"; Argentina

114 citations

Journal ArticleDOI
TL;DR: In this paper, the crystal structures of 2-Benzoylpyridine-methyl hydrazone (HBzMe) have been determined and its copper(II) [Cu(Bzme)Cl2] (1) and zinc(II] [Zn(HBzME)Cl 2] (2) complexes have been obtained.

114 citations

Journal ArticleDOI
TL;DR: In this paper, an adiabatic, nonradial pulsation study of GW Vir stars is presented based on PG 1159 evolutionary sequences with different stellar masses artificially derived from a full evolutionary sequence of 0.5895 M that has been computed by taking the evolutionary history of the progenitor star into account.
Abstract: An adiabatic, nonradial pulsation study of GW Vir stars is presented. The pulsation calculations were based on PG 1159 evolutionary sequences with different stellar masses artificially derived from a full evolutionary sequence of 0.5895 Mthat has been computed by taking the evolutionary history of the progenitor star into account. The artificial sequences were constructed by appropriately scaling the stellar mass of the 0.5895-Msequence well before the models reached the low-luminosity, high-gravity stage of the GW Vir domain. We computed g-mode pulsation periods appropriate to GW Vir variable stars. The implications for the mode-trapping properties of our PG 1159 models are discussed at length. We found that the mode-trapping features characterizing our PG 1159 models are mostly fixed by the stepped shape of the core chemical profile left by prior convective overshooting. This is particularly true at least for the range of periods observed in GW Vir stars. In addition, we make asteroseismic inferences about the internal structure of the GW Vir stars PG 1159-035, PG 2131+066, PG 1707+427, and PG 0122+200.

113 citations


Authors

Showing all 13198 results

NameH-indexPapersCitations
David Cameron1541586126067
Subir Sarkar1491542144614
Mayda Velasco137130987579
Diego F. Torres13794872180
Heidi Sandaker12899976517
Vincent Garonne12892176980
Farid Ould-Saada12893176394
Ole Røhne128103875752
Peter Hansen128127186210
Maria-Teresa Dova12777873558
Vladimir Sulin12788475329
Andrei Snesarev12787574907
James Catmore12789275086
Ruslan Mashinistov12686073897
Fernando Monticelli12684373385
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202333
2022315
20211,491
20201,738
20191,675
20181,527