860 research outputs found
A generalized framework to expand incomplete phylogenies using non-molecular phylogenetic information
Aim: The increasing availability of molecular information has lifted our understanding of species evolutionary relationships to unprecedent levels. However, current estimates of the world's biodiversity suggest that about a fifth of all extant species are yet to be described, and we still lack molecular information for many of the known species. Hence, evolutionary biologists will have to tackle phylogenetic uncertainty for a long time to come. This prospect has urged the development of software to expand phylogenies based on non-molecular phylogenetic information, and while the available tools provide some valuable features, major drawbacks persist and some of the proposed solutions are hardly generalizable to any group of organisms. Innovation: Here, we present a completely generalized and flexible framework to expand incomplete phylogenies. The framework is implemented in the R package “randtip”, a toolkit of functions that was designed to randomly bind phylogenetically uncertain taxa in backbone phylogenies through a fully customizable and automatic procedure that uses taxonomic ranks as a major source of phylogenetic information. Although randtip can generate fully operative phylogenies for any group of organisms using just a list of species and a backbone tree, we stress that the “blind” expansion of phylogenies using “quick-and-dirty” approaches often leads to suboptimal solutions. Thus, we discuss a variety of circumstances that may require customizing simulation parameters beyond default settings to optimally expand the trees, including a detailed step-by-step tutorial that was designed to provide guidelines to non-specialist users. Main Conclusions: Phylogenetic uncertainty should be tackled with caution, assessing potential pitfalls and opportunities to optimize parameter space prior to launch any simulation. Used judiciously, our framework will help evolutionary biologists to efficiently expand incomplete phylogenies and thereby account for phylogenetic uncertainty in quantitative analysesMinistry of Science and Innovation of
Spain, Grant/Award Number: CGL2017-
86926-P; Regional Government of
Madrid, Spain, Grant/Award Number: CM/
JIN/2019-00
A western representative of an eastern clade: phylogeographic history of the gypsum-associated plant Nepeta Hispanica
The preference of certain plant species for gypsum soils with a patchy distribution leads to disjunct population structures that are thought to generate island-like dynamics potentially influencing biogeographic patterns at multiple evolutionary scales. Here, we study the evolutionary and biogeographic history of Nepeta hispanica, a western Mediterranean plant associated with gypsum soils and displaying a patchy distribution with populations very distant from each other. Three approaches were used: (a) interspecific phylogenetic analyses based on nuclear DNA sequences of the ITS region to unveil the relationships and times of divergence between N. hispanica and its closest relatives; (b) phylogeographic analyses using plastid DNA regions trnS-trnG and psbJ-petA to evaluate the degree of genetic isolation between populations of N. hispanica, their relationships and their genetic diversity; and (c) ecological niche modelling to evaluate historical distributional changes. Results reveal that N. hispanica belongs to an eastern Mediterranean and Asian (Irano-Turanian) clade diversified in arid environments since the Miocene-Pliocene. This species represents the only lineage of this clade that colonised the western Mediterranean, probably through the northern Mediterranean coast (southern Europe). Present Iberian populations display a high plastid genetic diversity and, even if geographically distant from each other, they are highly connected according to the distribution of plastid haplotypes and lineages. This can be explained by a scenario involving a complex history of back-and-forth colonisation events, facilitated by a relative stability of suitable conditions for the species across the western Mediterranean throughout the QuaternaryThis work would not have been possible without the support of
Julian ´ García, Rub´en de Pablo, Jesús del Río, Leonardo Guti´errez, Javier
Puente, Javier Pavon ´ and Luis M. Medrano, who helped us with field
sample collection; Leopoldo Medina, Cyrille Chatelain, Jesús Riera and
Javier Hernandez, ´ who granted us permission to use specimens from the
MA, G, VAL and SALA herbaria respectively; and Emilio Cano, who
provided his invaluable help in the RJB-CSIC molecular systematics
laboratory. Fieldwork was financed by the Universidad Autonoma ´ de
Madrid with a grant to IRG’s Master thesis. Laboratory work was funded
by a Juan de la Cierva fellowship to MF-M (Spanish Ministry of Economy
and Competitiveness, reference IJCI-2015–23459
Revisión del catálogo de flora protegida de la Comunidad Autónoma de Madrid
La Comunidad de Madrid reúne en sus poco más de 8.000 km2 una notable riqueza florística gracias a la variedad de ambientes que contiene. Así, su flora vascular no bajaría de las 2.700 especies, más del 30% del catálogo florístico total español. Esta diversidad se repite asimismo entre los briófitos, grupo menos explorado pero del que no menos de 450 especies, el 40% de las peninsulares, viven en el territorio madrileñ
Could inhibition of metalloproteinases be used to block the process of metastasis?
Metastasis is a multisequential process that allows tumor cells to migrate to tissues distant from the primary tumor. Only a small number of cells escape from the primary tumor; however, the metastases generated are responsible for more than 90% of cancer deaths. Many metastatic processes initially require the total or partial start-up of a program for the transformation of tumor epithelial cells into mesenchymal cells (EMT). The launching of the EMT program is stimulated by cytokines and other elements produced by the diverse types of cells composing the tumor stroma. In parallel, a process of destabilization of the extracellular matrix (ECM) takes place by means of the synthesis of proteases of the matrix metalloproteinases (MMPs) family. EMC degradation allows the exportation of some tumor cells as mesenchymal cells to the circulatory system and their subsequent implantation in a tissue distant from the primary tumor. The blocking of these both processes appears as a hypothetical stop point in the metastatic mechanism. The present review deals with the different options to achieve the inhibition of MMPs, focusing on MMP7 as a target given its involvement in the metastatic processes of a wide variety of tumorsS
Open-days period in a group of Holstein cows
A study was conducted during an four years at the savanna of Bogota, whit 2.520 m.a.s.l. and an average temperature of 13.1°C, to analize open days' components in a group of 72 Holstein cows, with one to seven calvings. The parameters studied were: Calving to first postcalving heat; first heat to first service; first service to conception; services per pregnancy (sp) and days open which was the sum of the first three parameters above. Analysis of data indicated that the cows showed their first post-calving heat 61 ± 47 days after parturition; first service took place at 99 days and conception a 197 days, after calving, requiring 2.5 services per pregnancy. There was a stistically significant (P <0.05) effect of the number of calvings of the interval between first service and conception, this being especially notorious in cows with five, six and seven calvings. This interval was the main cause of the prolonged days-open period, and the relatively low number of services per pregnancy, suggest the need forfurther study of the causes ofthis long period after service.En un hato de la sabana de Bogotá a 2520 m.s.n.m. y una temperatura media de 13.1 grados centígrados, se adelantó un estudio que abarcó 4 años, sobre los períodos que componen los días abiertos de un grupo de 72 vacas Holstein con 1 a 7 partos. Se analizaron 5 parámetros: parto a primer celo, primer celo a primer servicio, primer servicio a concepción, días abiertos y servicios por concepción. Los análisis mostraron que después del parto el primer celo apareció a los 61 días, el primer servicio se realizó a los 99 días y la concepción se logró a los 197 días, con 2.5 servicios por concepción. Se observó efecto significativo (P menor que 0.05) del número de partos sobre el intervalo entre primer servicio y concepción, especialmente notorio en las vacas con 5, 6 y 7 partos. Este tercer período fue el principal causante del prolongado intervalo de días abiertos. Además, el número relativamente bajo de servicios por concepción sugiere la necesidad de estudiar cuidadosamente las causas que prolongan ese tercer período postparto.Ganado de leche-Ganadería lech
Neuropsychological profiles and neural correlates in typical and atypical variants of Alzheimer disease: A systematic qualitative review
Introduction: Neuropsychological symptoms and cortical atrophy patterns show similarities between typical Alzheimer’s Disease (AD) and its variants. Thus, correct diagnosis is difficult, leading to errors in the therapeutic process. Indeed, the challenge in cognitive neuroscience focuses on identifying key features of cognitive-linguistic profiles and improving the knowledge of neural correlates for accurate differential diagnosis between the heterogeneous profiles of typical and atypical AD.
Aim: This systematic review aims to describe different AD profiles, considering their neuropsychological symptoms and neural correlates.
Methods: The present study followed the PRISMA guidelines and included studies from the PubMed, ScienceDirect, Scopus, and Web of Science databases, published between 2011 and 2021.
Results: Thirty-one articles were included in this systematic review for critical analysis. Results suggest significant declines in episodic and working memory and executive function. Likewise, in all groups, verbal fluency and visuospatial/visuoconstructive skills declined. However, these symptoms overlap between typical AD, logopenic variant primary progressive aphasia, posterior cortical atrophy, behavioural/dysexecutive or frontal variant AD, and corticobasal syndrome. On the other hand, the neural correlate showed a pattern of atrophy in frontal, temporal, parietal, and occipital areas, even compromising the cuneus and precuneus.
Conclusion: Spontaneous language and semantic and phonological verbal fluency could be an important biomarker for differential diagnosis between typical AD and its atypical variants. Likewise, clinical assessment should consider using advanced neuroimaging techniques to establish early associations between brain dysfunction and neuropsychological performance, with particular attention to brain areas such as the cuneus and precuneus
Early use of marine resources by Middle/Upper Pleistocene human societies: The case of Benzú rockshelter (northern Africa)
This article examines the role played by marine resources for hunter-gatherer groups of the Middle/ Upper Pleistocenein the geohistorical regionaround the Straitsof Gibraltar, onthe basisof newevidence collected at the rock shelter of Benzú (North Africa). The stratigraphic sequence at Benzú has been dated to between 254 and 70 ka. The excavations have revealed the exploitation of marine gastropods and bivalves, alongside fish. The most common taxon in the sequence is the genus Patella. The analysis of the molluscs and their spatial distribution shows that these animals were purposely collected by humans, probably as a food source. In order to contribute to the debate about the origins and scale of the exploitation of marine resources during the Middle and Upper Pleistocene, the evidence collected at Benzú is interpreted within the broader context of North Africa and southern Europe. The similarity of groups of Homo sapiens sapiens in North Africa and Homo sapiens neanderthalensis in southern Europe in terms of lifestyle and subsistence strategies is interpreted as reflecting equally similar social and economic practices, in spite of the diversity of anthropological perspectives on the relationship between humans and the environment currently in vogue
I+D para detectar isótopos de difícil medida
Desde que el Centro Nacional de Aceleradores (CNA) abriera sus puertas en 1997, los investigadores españoles cuentan con un laboratorio de referencia para estudiar la caracterización y modificación de materiales. Uno de los proyectos que allí se desarrollan consiste en medir isótopos radiactivos, lo que con las técnicas empleadas hasta ahora no se había conseguido. Se trata de un estudio en el que coopera Enresa, empresa con la que el CNA selló un convenio de colaboración en 2008, y cuyos resultados contribuirán a mejorar la seguridad en el almacenamiento de los residuos.Since the National Accelerators Centre (NAC) opened its doors in 1997, Spanish researchers have had use of a reference centre to study the characterisation and modification of materials. One of the projects developed there has been to measure radioactive isotopes that have not been measured using the techniques employed to da
te. This study involves the cooperation of Enresa, with which the NAC established a collaboration agreement in 2008, and the results of which may help to improve the safe storage of waste
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