173 research outputs found
Evolutionary genomics : statistical and computational methods
This open access book addresses the challenge of analyzing and understanding the evolutionary dynamics of complex biological systems at the genomic level, and elaborates on some promising strategies that would bring us closer to uncovering of the vital relationships between genotype and phenotype. After a few educational primers, the book continues with sections on sequence homology and alignment, phylogenetic methods to study genome evolution, methodologies for evaluating selective pressures on genomic sequences as well as genomic evolution in light of protein domain architecture and transposable elements, population genomics and other omics, and discussions of current bottlenecks in handling and analyzing genomic data. Written for the highly successful Methods in Molecular Biology series, chapters include the kind of detail and expert implementation advice that lead to the best results. Authoritative and comprehensive, Evolutionary Genomics: Statistical and Computational Methods, Second Edition aims to serve both novices in biology with strong statistics and computational skills, and molecular biologists with a good grasp of standard mathematical concepts, in moving this important field of study forward
Genomic insights into rapid speciation within the world's largest tree genus Syzygium
The relative importance of the mechanisms underlying species radiation remains unclear. Here, the authors combine reference genome assembly and population genetics analyses to show that neutral forces have contributed to the radiation of the most species-rich tree genus Syzygium. Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification.Peer reviewe
Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts
Using archival data of low-redshift (z < 0.01) Type Ia supernovae (SN Ia) and
recent observations of high-redshift (0.16 < z <0.64; Matheson et al. 2005) SN
Ia, we study the "uniformity'' of the spectroscopic properties of nearby and
distant SN Ia. We find no difference in the measures we describe here. In this
paper, we base our analysis solely on line-profile morphology, focusing on
measurements of the velocity location of maximum absorption (vabs) and peak
emission (vpeak). We find that the evolution of vabs and vpeak for our sample
lines (Ca II 3945, Si II 6355, and S II 5454, 5640) is similar for both the
low- and high-redshift samples. We find that vabs for the weak S II 5454, 5640
lines, and vpeak for S II 5454, can be used to identify fast-declining [dm15 >
1.7] SN Ia, which are also subluminous. In addition, we give the first direct
evidence in two high-z SN Ia spectra of a double-absorption feature in Ca II
3945, an event also observed, though infrequently, in low-redshift SN Ia
spectra (6/22 SN Ia in our local sample). We report for the first time the
unambiguous and systematic intrinsic blueshift of peak emission of optical
P-Cygni line profiles in Type Ia spectra, by as much as 8000 km/s. All the
high-z SN Ia analyzed in this paper were discovered and followed up by the
ESSENCE collaboration, and are now publicly available.Comment: 28 pages (emulateapj), 15 figures; accepted for publication in A
Aplicaciones de la teorÃa de la información y la inteligencia artificial al testing de software
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de IngenierÃa de Sistemas lnformáticos y de Computación, leÃda el 4-05-2022Software Testing is a critical field for the software industry, as it has the main tools used to ensure the reliability of the produced software. Currently, mor then 50% of the time and resources for creating a software product are diverted to testing tasks, from unit testing to system testing. Moreover, there is a huge interest into automatising this field, as software gets bigger and the amount of required testing increases. however, software Testing is not only an industry oriented field; it is also a really interesting field with a noble goal (improving the reliability of software systems) that at the same tieme is full of problems to solve....Es Testing Software es un campo crÃtico para la industria del software, ya que éste contienen las principales herramientas que se usan para asegurar la fiabilidad del software producido. Hoy en dÃa, más del 50% del tiempo y recursos necesarios para crear un producto software son dirigidos a tareas de testing, desde el testing unitario al testing a nivel de sistema. Más aún, hay un gran interés en automatizar este campo, ya que el software cada vez es más grande y la cantidad de testing requerido crece. Sin embargo, el Testing de Software no es solo un campo orientado a la industria; también es un campo muy interesante con un objetivo noble (mejorar la fiabilidad de los sistemas software) que al mismo tiempo está lleno de problemas por resolver...Fac. de InformáticaTRUEunpu
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