Investigación sobre las ideas de los estudiantes acerca de la Historia

Los educadores deberían sentirse alentados por la consistencia con que la investigación muestra que la juventud participa activamente en el proceso de construcción de significado a partir de sus encuentros con la historia. También deberían sentirse satisfechos de saber que la docencia formal puede tener impacto en el desarrollo de las ideas de los estudiantes. Por otro lado, la investigación demuestra que algunos aspectos del sujeto pueden ser problemáticos: algunos estudiantes pueden tener problemas para reconciliar la historia escolar con las narraciones que han aprendido fuera de la escuela, por ejemplo, y no desarrollan fácilmente comprensiones completas del uso de la evidencia o del impacto de los factores sociales en las acciones y perspectivas de la gente del pasado. La investigación más importante en el futuro, por tanto, debería incluir la identificación de la diversidad de ideas que los estudiantes de orígenes diferentes aportan a la clase, y debería explorar el efecto de las prácticas docentes específicas en la comprensión. Este trabajo no sólo contribuiría a la producción académica sobre las ideas de los estudiantes acerca de la historia, sino que también podría conducir a aplicaciones prácticas en el aula.Educators should be encouraged by the consistency with which research shows that young people actively participate in the process of constructing meaning from their encounters with history. They should also be pleased to know that formal instruction can have an impact on students’ developing ideas. Besides, research proves that some aspects of the subject can be problematic: some students may experience some difficulty in reconciling school History with the narratives they have learnt outside school, for example. Hence, they do not easily develop complete understandings of the use of evidence or the impact of societal factors on the actions and perspectives of people in the past. The most important research in the future, therefore, would involve identifying the diversity of ideas that students from different backgrounds bring to the classroom and exploring the effect of specific instructional practices on their understanding. Such work would not only contribute to academic scholarship on students’ ideas about history but might also lead to practical classroom applications

Is what you see what you get? representations, metaphors and tools in mathematics didactics

This paper is exploratory in character. The aim is to investigate ways in which it is possible to use the theoretical concepts of representations, tools and metaphors to try to understand what learners of mathematics ‘see’ during classroom interactions (in their widest sense) and what they might get from such interactions. Through an analysis of a brief classroom episode, the suggestion is made that what learners see may not be the same as what they get. From each of several theoretical perspectives utilised in this paper, what learners ‘get’ appears to be something extra. According to our analysis, this something ‘extra’ is likely to depend on the form of technology being used and the representations and metaphors that are available to both teacher and learner

Study of pyridine-mediated electrochemical reduction of CO2 to methanol at high CO2 pressure

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The recently proposed highly efficient route of pyridine-catalyzed CO 2 reduction to methanol was explored on platinum electrodes at high CO 2 pressure. At 55 bar (5.5 MPa) of CO 2 , the bulk electrolysis in both potentiostatic and galvanostatic regimes resulted in methanol production with Faradaic yields of up to 10 % for the first 5–10 C cm −2 of charge passed. For longer electrolysis, the methanol concentration failed to increase proportionally and was limited to sub-ppm levels irrespective of biasing conditions and pyridine concentration. This limitation cannot be removed by electrode reactivation and/or pre-electrolysis and appears to be an inherent feature of the reduction process. In agreement with bulk electrolysis findings, the CV analysis supported by simulation indicated that hydrogen evolution is still the dominant electrode reaction in pyridine-containing electrolyte solution, even with an excess CO 2 concentration in the solution. No prominent contribution from either a direct or coupled CO 2 reduction was found. The results obtained suggest that the reduction of CO 2 to methanol is a transient process that is largely decoupled from the electrode charge transfer

DNA methylation at birth within the promoter of ANRIL predicts markers of cardiovascular risk at 9 years

Aims: Antisense non-coding RNA in the INK4 locus (ANRIL) fixed genetic variants have consistently been linked with coronary heart disease (CHD) risk. We investigated relationships between perinatal ANRIL promoter DNA methylation and CHD risk markers in children aged 9 years. Genetic variants in the non-coding RNA ANRIL identify it as an important CHD risk locus. Increasing evidence suggests that the early life environment may act through epigenetic processes to influence later CHD risk markers such as increased arterial pulse wave velocity (PWV, a measure of arterial stiffness) blood pressure or heart rate.Methods and results: Using pyrosequencing, ANRIL DNA methylation at nine CpG sites was measured in the umbilical cord from 144 children in a UK mother-offspring cohort and related to the descending aorta PWV measured by velocity-encoded phase contrast MRI at age 9 years. Perinatal methylation was not associated with child’s later blood pressure, but higher methylation at CpG5 was associated with increased childhood PWV (??=?0.066 m/s/10 % methylation increase [95 % CI, 0.004 to 0.128], p?=?0.037); 10 % decreases in methylation at CpG1 and CpG2 were associated with increased heart rate (CpG1 ??=?1.93 [0.07 to 3.8] beats/min, p?=?0.041; CpG2 ??=?2.30 [0.18 to 4.41] beats/min, p?=?0.033, accounting for potential confounding variables). The associations with perinatal ANRIL promoter methylation were independent of neighbouring fixed genetic variants.Conclusions: Our findings suggest developmental epigenetic regulation of ANRIL promoter methylation as a factor in later CHD risk in children.<br/

A revised spiralian homeobox gene classification incorporating new polychaete transcriptomes reveals a diverse TALE class and a divergent Hox gene

The diversity of mechanisms and capacity for regeneration across the Metazoa present an intriguing challenge in evolutionary biology, impacting on the burgeoning field of regenerative medicine. Broad taxonomic sampling is essential to improve our understanding of regeneration, and studies outside of the traditional model organisms have proved extremely informative. Within the historically under-studied Spiralia, the Annelida have an impressive variety of tractable regenerative systems. The biomeralising, blastema-less regeneration of the head appendage (operculum) of the serpulid polychaete keelworm Spirobranchus (formerly Pomatoceros) lamarcki is one such system. To profile potential regulatory mechanisms, we classified the homeobox gene content of opercular regeneration transcriptomes. As a result of retrieving several difficult-to-classify homeobox sequences, we performed an extensive search and phylogenetic analysis of the TALE and PRD-class homeobox gene content of a broad selection of lophotrochozoan genomes. These analyses contribute to our increasing understanding of the diversity, taxonomic extent, rapid evolution, and radical flexibility of these recently discovered homeobox gene radiations. Our expansion and integration of previous nomenclature systems helps to clarify their cryptic orthology. We also describe an unusual divergent S. lamarcki Antp gene, a previously unclassified lophotrochozoan orphan gene family (Lopx), and a number of novel Nk class orphan genes. The expression and potential involvement of many of these lineage- and clade-restricted homeobox genes in S. lamarcki operculum regeneration provides an example of diversity in regenerative mechanisms, as well as significantly improving our understanding of homeobox gene evolution.Publisher PDFPeer reviewe