Juan Ramón Pérez Pérez

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Telomerase, a ribonucleic acid-protein complex, adds hexameric repeats of 5'-TTAGGG-3' to the ends of mammalian chromosomal DNA (telomeres) to compensate for the progressive loss that occurs with successive rounds of DNA replication. Although somatic cells do not express telomerase, germ cells and immortalized cells, including neoplastic cells, express this(More)
One key element to consider when developing e-learning systems is the adaptation of the system to the cognitive characteristics of the students. However, making this adaptation is not a simple process; it implies the study and conjunction of technical and pedagogical aspects. This article was written from the point of view of a designer who, without being(More)
To characterize the in vivo toxicity of phosphorothioate antisense oligonucleotides against rel A (p65 subunit of NF-kappa B transcription factor), forty-eight 6-week-old CD-1 mice were split into 4 groups (6/sex/group) receiving vehicle (phosphate-buffered saline) or doses of 50, 100, and 150 mg/kg of rel A antisense oligonucleotides intraperitoneally 3(More)
The p50 and p65 subunits of NF-kappa B represent two members of a gene family that shares considerable homology to the rel oncogene. Proteins encoded by these genes form homo- and heterodimers which recognize a common DNA sequence motif. Recent data have suggested that homodimers of individual subunits of NF-kappa B can selectively activate gene expression(More)
We previously identified a carboxy-terminal transactivation function termed AF-2 within the last 15 amino acids of the ligand binding domain of the human retinoic acid receptor alpha (hRAR alpha). Truncation of this region abolished transcriptional activity. Here we provide a systematic analysis using alanine scanning mutagenesis of amino acids from Ser405(More)
Multi-channel access to information has gained interest in the past years. Yet, the usage of alternative modes of interaction has not been extended into mainstream e-learning systems. This paper illustrates how the elements of a multi-channel learning framework can be identified and used in practice to enable complementary aural access to visual-only(More)
In general, research confirms that learning is more effective when students obtain feedback regarding their learning progress. Currently, new versions of e-learning platforms include indicators that provide some static feedback mechanisms and help both learners and educators in planning their learning strategies. This paper explains the usage of indicators(More)
The learning of programming presents many difficulties for students. Nowadays, a number of software tools are available that enable students in programming courses to develop and exercise their knowledge and skills. However, these tools do not examine their work or provide students with indications on their learning process. In this paper we introduce a(More)