Invariant versus classical quartet inference when evolution is heterogeneous across sites and lineages

One reason why classical phylogenetic reconstruction methods fail to correctly infer the underlying topology is because they assume oversimplified models. In this paper we propose a topology reconstruction method consistent with the most general Markov model of nucleotide substitution, which can also deal with data coming from mixtures on the same topology. It is based on an idea of Eriksson on using phylogenetic invariants and provides a system of weights that can be used as input of quartet-based methods. We study its performance on real data and on a wide range of simulated 4-taxon data (both time-homogeneous and nonhomogeneous, with or without among-site rate heterogeneity, and with different branch length settings). We compare it to the classical methods of neighbor-joining (with paralinear distance), maximum likelihood (with different underlying models), and maximum parsimony. Our results show that this method is accurate and robust, has a similar performance to ML when data satisfies the assumptions of both methods, and outperforms all methods when these are based on inappropriate substitution models or when both long and short branches are present. If alignments are long enough, then it also outperforms other methods when some of its assumptions are violated.Comment: 32 pages; 9 figure

No és la meva competència intercultural, soc jo.’ La identitat intercultural del professorat de llengües estrangeres en formació

This article examines the intercultural identity of pre-service foreign language teachers to determine whether they are aware of their intercultural stance and that of others, and whether they portray an identifiable emergent professional persona in relation to interculturality. The ultimate goal of this study is to identify common traits on which to focus future teacher training. The results show that these prospective teachers display an incipient intercultural identity characterised by a tendency to avoid agency and a certain shortage of intercultural knowledge, yet they are notably concerned about their professional image and their responsibility in work environmentsEste artículo indaga en la identidad intercultural del profesorado de lenguas extranjeras en formación para averiguar si es consciente de su postura intercultural y de la de otros, y si presenta una imagen profesional emergente reconocible en relación con la interculturalidad. El objetivo final de este estudio es identificar rasgos comunes en los que podría centrarse la formación del profesorado. Los resultados demuestran que este futuro profesorado muestra una identidad intercultural incipiente caracterizada por su tendencia a evitar la intervención y por una cierta falta de conocimiento intercultural, aunque está notablemente preocupado por su imagen profesional y su responsabilidad en contextos laboralesAquest article indaga en la identitat intercultural del professorat de llengües estrangeres en formació per esbrinar si és conscient de la seva postura intercultural i de la dels altres, i si presenta una imatge professional emergent recognoscible en relació amb la interculturalitat. L’objectiu final d’aquest estudi és identificar trets comuns en els quals es podria centrar la formació del professorat. Els resultats demostren que aquest futur professorat té una identitat intercultural incipient caracteritzada per la seva tendència a evitar la intervenció i per una certa falta de coneixement intercultural, encara que està notablement preocupat per la seva imatge professional i la seva responsabilitat en els contextos laboralsThis work was supported by the Spanish Ministry of Economy and Competition under Grant FFI2016-77540

Outer commutator words are uniformly concise

We prove that outer commutator words are uniformly concise, i.e. if an outer commutator word w takes m different values in a group G, then the order of the verbal subgroup w(G) is bounded by a function depending only on m and not on w or G. This is obtained as a consequence of a structure theorem for the subgroup w(G), which is valid if G is soluble, and without assuming that w takes finitely many values in G. More precisely, there is an abelian series of w(G), such that every section of the series can be generated by values of w all of whose powers are also values of w in that section. For the proof of this latter result, we introduce a new representation of outer commutator words by means of binary trees, and we use the structure of the trees to set up an appropriate induction

Local description of phylogenetic group-based models

Motivated by phylogenetics, our aim is to obtain a system of equations that define a phylogenetic variety on an open set containing the biologically meaningful points. In this paper we consider phylogenetic varieties defined via group-based models. For any finite abelian group $G$, we provide an explicit construction of $codim X$ phylogenetic invariants (polynomial equations) of degree at most $|G|$ that define the variety $X$ on a Zariski open set $U$. The set $U$ contains all biologically meaningful points when $G$ is the group of the Kimura 3-parameter model. In particular, our main result confirms a conjecture by the third author and, on the set $U$, a couple of conjectures by Bernd Sturmfels and Seth Sullivant.Comment: 22 pages, 7 figure

Embeddability and rate identifiability of Kimura 2-parameter matrices

Deciding whether a Markov matrix is embeddable (i.e. can be written as the exponential of a rate matrix) is an open problem even for $4\times 4$ matrices. We study the embedding problem and rate identifiability for the K80 model of nucleotide substitution. For these $4\times 4$ matrices, we fully characterize the set of embeddable K80 Markov matrices and the set of embeddable matrices for which rates are identifiable. In particular, we describe an open subset of embeddable matrices with non-identifiable rates. This set contains matrices with positive eigenvalues and also diagonal largest in column matrices, which might lead to consequences in parameter estimation in phylogenetics. Finally, we compute the relative volumes of embeddable K80 matrices and of embeddable matrices with identifiable rates. This study concludes the embedding problem for the more general model K81 and its submodels, which had been initiated by the last two authors in a separate work.Comment: 20 pages; 10 figure

Impact of the Information and Communication Technologies on the Education of Students with Down Syndrome: a Bibliometric Study (2008- 2018)

This article analyzes the impact of the Information and Communication Technologies (ICT) on students with Down syndrome through the consult of scientific articles published during the 2008 to 2018 period, in five scientific journal databases utilized in the academic world. Through a descriptive and quantitative methodology, the most significant bibliometric data according to citation index is shown. Likewise, a methodology based on the analysis of co-words and clustering techniques is applied through a bibliometric maps, in order to determine the fields of scientific study. The results show that articles published have a medium-low index of impact. There are linked with the importance of using ICT with these students, from educational inclusion and accessibility perspective

Menores y medios de comunicación

Currently there are numerous television programs and press that use to inform about the personal and intimate life of anonymous persons, minors in many cases, whose situation is considered to be at an important public interest, putting at risk evident rights of his personality. This research work attempts to give an answer to the need of special protection of minors in this área. Actualmente son numerosos los programas de televisión y la información en prensa que se hacen eco de la vida personal e íntima de, en ocasiones, personas anónimas, menores en muchos casos, cuya situación se considera de un interés público relevante, poniendo en riesgo evidente los derechos de su personalidad. Este trabajo intenta dar respuesta a la especial necesidad de protección de los menores de edad ante los medios de comunicación

Uses of also in oral semi-informal German

In recent grammars and dictionaries also ('therefore, so, well') continues to be preferably presented as an adverb with a conclusive-consecutive connective function that essentially corresponds to its use in formal written German. Its function as a modal particle is documented, however, since the beginnings of what is known as Partikelforschung, though not all its uses have been systematically investigated contrasting oral and written German, either in mode or concept. In this article we analyse the uses of also in semi-informal oral interactions on the basis of empirical data (from a subsample of the VARCOM corpus). Specifically, we will analyse the presence and frequency of also at the beginning of a sentence or sequence, the functions it serves as a logical-semantic connector or discourse and interaction marker and the interrelations between these functions, in order to contrast these results with the description of also provided by current reference works.Also (per tant, és a dir, doncs, bé, vaja) continua apareixent en les darreres gramàtiques i diccionaris de l'alemany preferentment com a adverbi amb funció connectiva conclusivo-consecutiva, funció que es correspon fonamentalment amb l'ús que té en alemany escrit formal. Tanmateix, la seva funcionalitat com a partícula modal està documentada des dels inicis de l'anomenada Partikelforschung, tot i que encara resten usos per investigar de manera sistemàtica tenint en compte les diferències entre l'alemany oral i l'alemany escrit -en la concepció o en la realització. Sobre la base de dades empíriques, en aquest article ens proposem analitzar els usos d'also en interaccions orals semi-informals. Les dades procedeixen d'una submostra del corpus VARCOM (alemany, castellà, català) que recull la producció de parlants nadius d'alemany, castellà i català en aquestes tres llengües com a L1, L2 i LE; els textos han estat elicitats mitjançant entrevistes semiestructurades i tasques de producció de textos narratius, descriptius, instructius, expositius i argumentatius. En concret, analitzem la presència i la freqüència d'also en posició inicial d'oració o seqüència, les funcions que realitza com a connector logicosemàntic o com a marcador del discurs i la interacció i les interrelacions entre aquestes funcions, a fi de contrastar els resultats amb la descripció que ofereixen les obres de referència actuals