Ribosomal intergenic spacer (IGS) length variation across the Drosophilinae (Diptera: Drosophilidae)

BACKGROUND: The intergenic spacer of the ribosomal genes in eukaryotes (IGS) contains duplications of the core transcription promoter. The number of these duplicated promoters, as measured by the IGS length, appears to be correlated with growth rate and development time in several distantly related taxa. In the present study, we examined IGS length variation across a number of species of Drosophila to determine the amount of variation in this trait across different evolutionary time scales. Furthermore, we compared the usefulness of two methods commonly used to determine IGS length: Southern Blot Hybridization (SB) and Polymerase Chain Reaction (PCR). RESULTS: Our results show broad variation in IGS length across the genus Drosophila, but closely related species had similar IGS lengths. Our results also suggest that PCR tends to underestimate the true IGS size when the size is greater than 5 kb, and that this degree of underestimation is greater as the IGS size increases. CONCLUSION: Broad variation in IGS length occurs across large evolutionary divergences in the subfamily Drosophilinae. Although average IGS length has been shown to evolve rapidly under artificial selection, closely related taxa generally have similar average IGS lengths. Our comparison of methods suggests that without previous knowledge of the DNA sequence of the IGS and flanking regions, both methods be used to accurately measure IGS length

Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil WasteWaters

The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol

Questions to tell what's going on

La idea de un trabajo en común surgió de una comunicación telefónica con Mariana cuando ella ya estaba en cuarentena en Italia y aquí recién había un par de casos importados. Nos propusimos encontrar la forma de contar lo que pasaba, en principio a través de una historia gráfica, y lo primero que ilustró Mariana, con personajes vestidos a la usanza de los médicos medievales en la peste negra, fue una serie de preguntas que me formulé al principio de la pandemia: -¿Hay barbijos contra el odio? -¿Qué nos protege de la estupidez? -¿En qué hospital se tratan las injusticias? -¿Cómo prevenirnos de la hipocresía? -¿Cuándo sale la vacuna contra el miedo?Facultad de Periodismo y Comunicación Socia

Conflicting genomic signals affect phylogenetic inference in four species of North American pines

Adaptive evolutionary processes in plants may be accompanied by episodes of introgression, parallel evolution and incomplete lineage sorting that pose challenges in untangling species evolutionary history. Genus Pinus (pines) is one of the most abundant and most studied groups among gymnosperms, and a good example of a lineage where these phenomena have been observed. Pines are among the most ecologically and economically important plant species. Some, such as the pines of the southeastern USA (southern pines in subsection Australes), are subjects of intensive breeding programmes. Despite numerous published studies, the evolutionary history of Australes remains ambiguous and often controversial. We studied the phylogeny of four major southern pine species: shortleaf (Pinus echinata), slash (P. elliottii), longleaf (P. palustris) and loblolly (P. taeda), using sequences from 11 nuclear loci and maximum likelihood and Bayesian methods. Our analysis encountered resolution difficulties similar to earlier published studies. Although incomplete lineage sorting and introgression are two phenomena presumptively underlying our results, the phylogenetic inferences seem to be also influenced by the genes examined, with certain topologies supported by sets of genes sharing common putative functionalities. For example, genes involved in wood formation supported the clade echinata–taeda, genes linked to plant defence supported the clade echinata–elliottii and genes linked to water management properties supported the clade echinata–palustris. The support for these clades was very high and consistent across methods. We discuss the potential factors that could underlie these observations, including incomplete lineage sorting, hybridization and parallel or adaptive evolution. Our results likely reflect the relatively short evolutionary history of the subsection that is thought to have begun during the middle Miocene and has been influenced by climate fluctuations

Perfiles de competencias y concepciones sobre la escritura académica en estudiantes universitarios

The version of record of this manuscript has been published and is avalilable in Cultura y Educación 2015 http://www.tandfonline.com/10.1080/11356405.2015.1072358This study analyses Spanish undergraduates’ perceptions of their competency in academic writing, as well as their perception of the criteria that define its quality. We identified student profiles and examined their relationship with (1) certain sample characteristics, such as years of university experience, area of study and students’ gender, and (2) variables related to the process of writing, namely the students’ perception of the writing process and the importance they attribute to its characteristics. The data obtained came from the European Writing Survey (EUWRIT) which was administered to 1,044 students from nine Spanish universities. Profiles were identified by means of k-means cluster analysis. The relationship between these profiles and the variables studied was examined by means of chi-squared analyses and univariate ANOVAs. Two profiles were identified: students who are confident about their writing skills and who acknowledge the importance of writing in their field of knowledge; and students who are relatively confident about their writing ability and who consider writing to be relatively important in their subject areaEste estudio analiza la percepción de estudiantes universitarios españoles sobre su competencia en escritura académica y sobre el criterio que define la calidad de dicha escritura. Se identificaron los perfiles de estudiantes y se examinó su relación con (1) algunas características de la muestra — años de experiencia universitaria, ámbito de estudio de los estudiantes y su género; y (2) variables relacionadas con el proceso de escritura — las percepciones que los estudiantes tienen sobre el proceso de escritura y la importancia que atribuyen a las características de dicho proceso. Los datos obtenidos proceden de la Encuesta Europea sobre la Escritura Académica (EEEA), que fue administrada a 1,044 estudiantes de nueve universidades españolas. La relación entre estos perfiles y las variables estudiadas fue examinada mediante análisis de chi-cuadrado y ANOVAS univariados. Se identificaron dos perfiles distintos: estudiantes que confían en sus habilidades de escritura y que reconocen la importancia de la escritura en su ámbito de conocimiento; y los estudiantes que confían relativamente en sus habilidades de escritura y que consideran que la escritura es relativamente importante en su ámbito de conocimientoThis study was partially funded by Spain´s Ministry of Economy and Competitiveness, DGICyT (EDU2013-46606-C2-2-R y EDU2013-46606-C2-1-R) and the European Self-perceived competencies of academic writing

Profiles of self-perceived competencies and conceptions of academic writing in university students

This study analyses Spanish undergraduates' perceptions of their competency in academic writing, as well as their perception of the criteria that define its quality. We identified student profiles and examined their relationship with (1) certain sample characteristics, such as years of university experience, area of study and students' gender, and (2) variables related to the process of writing, namely the students' perception of the writing process and the importance they attribute to its characteristics. The data obtained came from the European Writing Survey (EUWRIT) which was administered to 1,044 students from nine Spanish universities. Profiles were identified by means of k-means cluster analysis. The relationship between these profiles and the variables studied was examined by means of chi-squared analyses and univariate ANOVAs. Two profiles were identified: students who are confident about their writing skills and who acknowledge the importance of writing in their field of knowledge; and students who are relatively confident about their writing ability and who consider writing to be relatively important in their subject area. ResumenEste estudio analiza la percepcion de estudiantes universitarios espanoles sobre su competencia en escritura academica y sobre el criterio que define la calidad de dicha escritura. Se identificaron los perfiles de estudiantes y se examino su relacion con (1) algunas caracteristicas de la muestra anos de experiencia universitaria, ambito de estudio de los estudiantes y su genero; y (2) variables relacionadas con el proceso de escritura las percepciones que los estudiantes tienen sobre el proceso de escritura y la importancia que atribuyen a las caracteristicas de dicho proceso. Los datos obtenidos proceden de la Encuesta Europea sobre la Escritura Academica (EEEA), que fue administrada a 1,044 estudiantes de nueve universidades espanolas. La relacion entre estos perfiles y las variables estudiadas fue examinada mediante analisis de chi-cuadrado y ANOVAS univariados. Se identificaron dos perfiles distintos: estudiantes que confian en sus habilidades de escritura y que reconocen la importancia de la escritura en su ambito de conocimiento; y los estudiantes que confian relativamente en sus habilidades de escritura y que consideran que la escritura es relativamente importante en su ambito de conocimiento

Evolution of African barbs from the Lake Victoria drainage system, Kenya

The Lake Victoria drainage basin (LVD) in Kenya is home to ten nominal species of small barbs (Enteromius) and one of large barbs (Labeobarbus altianalis). A recent molecular study genetically characterized small barbs in this region and found evidence of introgression between certain species, complicating the taxonomy and species identification of these fishes. This study aimed to extend our understanding on the evolution of these fishes by: (1) determining whether putatively pure individuals of Enteromius cercops are found in the Kenyan LVD, as the previous study only found hybrid individuals of this species in this region; (2) testing the sister relationship between Enteromius profundus, endemic to Lake Victoria, and Enteromius radiatus, also found in Lake Victoria, which had been previously synonymized; (3) examining the phylogenetic relationships of small barbs of the Kenyan LVD with those reported from other ichthyological provinces of Africa; and (4) examining the phylogenetic relationships of Labeobarbus altianalis with other Labeobarbus species. To this end, we obtained mitochondrial Cytochrome b and nuclear Growth Hormone (GH) intron 2 gene sequences of nine Enteromius species from the LVD in Kenya, as well as cytochrome b sequences for L. altianalis. We conducted Maximum likelihood and Bayesian phylogenetic analyses to establish their evolutionary relationships in relation to many other barbs specimens from Africa. Phylogenetic analyses did not reveal instances of hybridization/introgression among the individuals sequenced by us. A sister relationship between E. profundus and E. radiatus was not found. This latter species shows instead a sister relationship with a lineage comprised of two species from West Africa. Other sister relationships between taxa from the East coast and other ecoregions from Africa are observed, suggesting that past drainage connections and vicariant events contributed to the diversification of Enteromius. Finally, only a single haplotype was recovered among the L. altianalis individuals examined, which is most similar to a specimen from Lake Edward in Uganda

Learning paths in synthesis writing: which learning path contributes most to which learning outcome?

This paper presents a secondary analysis of data collected during an intervention study in which students learnt to synthesise pairs of texts presenting opposite views on controversial issues. The original intervention study included two treatments and examined the effects of two instruction conditions when instructional materials and tasks were held constant. The participants were 114 undergraduate psychology students. The object of the instruction was a guide on strategies for writing an argumentative synthesis text. However, the instruction varied between explicit strategy instruction, consisting of explaining each of the process’s four phases (exploring and identifying arguments and counterarguments, contrasting positions, drawing an integrative conclusion, and organising and revising the final draft), modelled via videos, versus self-study of the written strategy guide. After the initial instruction session, the students in both groups practiced collaboratively writing synthesis texts over two sessions with access to the strategy guide. The primary study compared the individually written pre- and posttest syntheses and found statistically significant differences favouring explicit instruction in both dependent variables: the argumentation coverage and the level of integration. The secondary analysis reported in the current paper involved scoring additional written syntheses produced during two practice sessions and then analysing the data for all time points (pretest, posttest, and the two practice sessions) using structural equation modelling (SEM) to test whether explicit instruction directly or indirectly affected the two indicators of good argumentative synthesis texts—argument coverage and integration—via the following collaborative practice. The results suggested two different learning paths for both dependent variables: explicit instruction is effective for both variables, while collaborative practice only has an additional indirect effect on argument coverageThis research project was funded under the National Program for Basic Research Projects 2014–2016 by the Spanish Ministry of Economy and Competitiveness (EDU2013-46606-C2-1) and Mobility Stays Salvador Madariaga 2015 by the Spanish Ministry of Education, Culture and Sport (PRX15/00042