On the origin of the selectivity of plasmidic H-NS towards horizontally acquired DNA: Linking H-NS oligomerization and cooperative DNA binding

The nucleoid-associated protein H-NS is a global modulator of the expression of genes associated with adaptation to environmental changes. A variant of H-NS expressed in the R27 plasmid was previously shown to selectively modulate the expression of horizontally acquired genes, with minimal effects on core genes that are repressed by the chromosomal form of H-NS. Both H-NS proteins are formed by an oligomerization domain and a DNA-binding domain, which are connected by a linker that is highly flexible in the absence of DNA. We studied DNA binding by means of oligomer-forming chimeric proteins in which domains of the chromosomal and plasmidic variants are exchanged, as well as in monomeric truncated forms containing the DNA-binding domain and variable portions of the linker. Point mutations in the linker were also examined in full-length and truncated H-NS constructs. These experiments show that the linker region contributes to DNA binding affinity and that it is a main component of the distinct DNA binding properties of chromosomal and plasmidic H-NS. We propose that interactions between the linker and DNA limit the flexibility of the connection between H- NS oligomerization and DNA binding and provide an allosteric indirect readout mechanism to detect long- range distortions of DNA, thus enabling discrimination between core and horizontally acquired DNA.

Estudi de noves estratègies encapsuladores d’antimalàrics i distribució de nanovectors polimèrics en Anopheles atroparvus

En aquest treball s’ha estudiat el comportament de compostos antimalàrics com els fàrmacs i els polímers en diferents situacions. Una de les barreres que ha estat identificada com a principal obstacle per a una millora de l’eficàcia dels compostos antimalàrics, és la limitació en la quantitat de fàrmac que pot ser encapsulada dins un liposoma, i que depèn de la seva solubilitat en medi aquós. Amb la inspiració de la descripció d’un nou tipus de nanocàpsules amb aplicacions oncològiques capaces d’encapsular grans quantitats de fàrmacs (protocells, Ashley et al., 2011). Els constructes formats per liposomes amb un nucli d’òxid de silici altament porós capaç de contenir el fàrmac, s’anomenen “protocells”, que en comparació als liposomes, tenen una major selectivitat i estabilitat, i permeten alliberar altes concentracions de droga directament al citosol de les cèl·lules cancerígenes. Aquest estudi es basa en la fabricació d’aquests nous nanovectors que continguin fàrmacs antimalàrics i té com a objectiu futur dirigir-los a eritròcits infectats per malària (pRBCs). Una altra part del treball és l’estudi de la distribució del polímer ISA-FITC en Anopheles atroparvus. Sabent que els polímers han estat utilitzats com a transportadors antimalàrics, es va pensar en l’opció d’eliminar el paràsit a dins del mateix mosquit, com una alternativa a tots el estudis realitzats fins ara centrats en les etapes d’infecció de l’hoste. Per aquest motiu es va idear l’experiment pensant en aquest polímer amb la intenció final de veure la seva localització en un mosquit Anopheles lliure del paràsit. OBJECTIUS: Determinació de la capacitat encapsuladora de tres tipus de nanopartícules, fabricades amb el mateix material però amb característiques de mida i càrrega diferents, incubant-les amb cinc fàrmacs antimalàrics. El blau de metilè, la primaquina, la cloroquina, la quinina i la curcumina, cadascun d’ells amb característiques de pH, solubilitat i estructura diferents. Alguns d’ells són fàrmacs que no s’han emprat en altres estudis degut a la seva toxicitat o elevada inespecificitat (la qual es pretén reduir un cop encapsulats en protocells). Construcció de “protocells” un cop determinada la millor nanopartícula encapsuladora i fàrmac candidat i determinació de la concentració de fàrmac que podien contenir, i el ritme d’alliberament d’aquest en PBS (simulant les condicions fisiològiques dels pRBCs). Estudi de la localització del polímer antimalàric ISA-FITC en l’anatomia del mosquit Anopheles Atroparvus. PROCEDIMENTS: Mètodes espectrofotomètrics Microscopia Cryo-electrònica de transmissió Microscopia confocal de fluorescència

Establishing the Stages and Processes of Change for Weight Loss by Consensus of Experts

The present study aimed to establish, by a consensus of experts, the stages and processes of change for weight management in overweight and obese people. The first step involved developing two questionnaires aimed at assessing stages and processes of change for weight loss in overweight and obese people. The processes-ofchange questionnaire consisted of 12 subscales, and contained 107 items. A three-round Delphi study was carried out through a website, where participants were asked to give their opinion about the representativeness and clarity of the scale items. The stages-of-change questionnaire consisted of five items and was presented in the final round of the study. A team of 66 experts in the obesity field from 29 countries participated in the study. They were selected either because they belonged to the organizing committee of international associations related to obesity, or because of their research career. The required changes in the questionnaire were made according to the opinions of the participants. Some of these were the result of the group statistical response, whereas others were due to the suggestions made by the participants. A final version of the questionnaire consisting of 63 items was eventually obtained. The present study produced two questionnaires to assess stages and processes of change for weight management. The strength of the study lies in the consensus reached by the panel of experts in order to establish the required content of the questionnaires. The two measures provide useful tools for practitioners who wish to tailor weight-management interventions according to transtheoretical model constructs.

A signaling mechanism coupling netrin-1/deleted in colorectal cancer chemoattraction to SNARE-mediated exocytosis in axonal growth cones

Directed cell migration and axonal guidance are essential steps in neural development. Both processes are controlled by specific guidance cues that activate the signaling cascades that ultimately control cytoskeletal dynamics. Another essential step in migration and axonal guidance is the regulation of plasmalemma turnover and exocytosis in leading edges and growth cones. However, the cross talk mechanisms linking guidance receptors and membrane exocytosis are not understood. Netrin-1 is a chemoattractive cue required for the formation of commissural pathways. Here, we show that the Netrin-1 receptor deleted in colorectal cancer (DCC) forms a protein complex with the t-SNARE (target SNARE) protein Syntaxin-1 (Sytx1). This interaction is Netrin-1 dependent both in vitro and in vivo, and requires specific Sytx1 and DCC domains. Blockade of Sytx1 function by using botulinum toxins abolished Netrin-1-dependent chemoattraction of axons in mouse neuronal cultures. Similar loss-of-function experiments in the chicken spinal cord in vivo using dominant-negative Sytx1 constructs or RNAi led to defects in commissural axon pathfinding reminiscent to those described in Netrin-1 and DCC loss-of-function models. We also show that Netrin-1 elicits exocytosis at growth cones in a Sytx1-dependent manner. Moreover, we demonstrate that the Sytx1/DCC complex associates with the v-SNARE (vesicle SNARE) tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP) and that knockdown of TI-VAMP in the commissural pathway in the spinal cord results in aberrant axonal guidance phenotypes. Our data provide evidence of a new signaling mechanism that couples chemotropic Netrin-1/DCC axonal guidance and Sytx1/TI-VAMP SNARE proteins regulating membrane turnover and exocytosis.

A signaling mechanism coupling netrin-1/deleted in colorectal cancer chemoattraction to SNARE-mediated exocytosis in axonal growth cones

Directed cell migration and axonal guidance are essential steps in neural development. Both processes are controlled by specific guidance cues that activate the signaling cascades that ultimately control cytoskeletal dynamics. Another essential step in migration and axonal guidance is the regulation of plasmalemma turnover and exocytosis in leading edges and growth cones. However, the cross talk mechanisms linking guidance receptors and membrane exocytosis are not understood. Netrin-1 is a chemoattractive cue required for the formation of commissural pathways. Here, we show that the Netrin-1 receptor deleted in colorectal cancer (DCC) forms a protein complex with the t-SNARE (target SNARE) protein Syntaxin-1 (Sytx1). This interaction is Netrin-1 dependent both in vitro and in vivo, and requires specific Sytx1 and DCC domains. Blockade of Sytx1 function by using botulinum toxins abolished Netrin-1-dependent chemoattraction of axons in mouse neuronal cultures. Similar loss-of-function experiments in the chicken spinal cord in vivo using dominant-negative Sytx1 constructs or RNAi led to defects in commissural axon pathfinding reminiscent to those described in Netrin-1 and DCC loss-of-function models. We also show that Netrin-1 elicits exocytosis at growth cones in a Sytx1-dependent manner. Moreover, we demonstrate that the Sytx1/DCC complex associates with the v-SNARE (vesicle SNARE) tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP) and that knockdown of TI-VAMP in the commissural pathway in the spinal cord results in aberrant axonal guidance phenotypes. Our data provide evidence of a new signaling mechanism that couples chemotropic Netrin-1/DCC axonal guidance and Sytx1/TI-VAMP SNARE proteins regulating membrane turnover and exocytosis.

A signaling mechanism coupling netrin-1/deleted in colorectal cancer chemoattraction to SNARE-mediated exocytosis in axonal growth cones

Directed cell migration and axonal guidance are essential steps in neural development. Both processes are controlled by specific guidance cues that activate the signaling cascades that ultimately control cytoskeletal dynamics. Another essential step in migration and axonal guidance is the regulation of plasmalemma turnover and exocytosis in leading edges and growth cones. However, the cross talk mechanisms linking guidance receptors and membrane exocytosis are not understood. Netrin-1 is a chemoattractive cue required for the formation of commissural pathways. Here, we show that the Netrin-1 receptor deleted in colorectal cancer (DCC) forms a protein complex with the t-SNARE (target SNARE) protein Syntaxin-1 (Sytx1). This interaction is Netrin-1 dependent both in vitro and in vivo, and requires specific Sytx1 and DCC domains. Blockade of Sytx1 function by using botulinum toxins abolished Netrin-1-dependent chemoattraction of axons in mouse neuronal cultures. Similar loss-of-function experiments in the chicken spinal cord in vivo using dominant-negative Sytx1 constructs or RNAi led to defects in commissural axon pathfinding reminiscent to those described in Netrin-1 and DCC loss-of-function models. We also show that Netrin-1 elicits exocytosis at growth cones in a Sytx1-dependent manner. Moreover, we demonstrate that the Sytx1/DCC complex associates with the v-SNARE (vesicle SNARE) tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP) and that knockdown of TI-VAMP in the commissural pathway in the spinal cord results in aberrant axonal guidance phenotypes. Our data provide evidence of a new signaling mechanism that couples chemotropic Netrin-1/DCC axonal guidance and Sytx1/TI-VAMP SNARE proteins regulating membrane turnover and exocytosis.

Evaluación de la formación del profesorado universitario novel

Durante el curso académico 2001-2002 se desarrolló en la Universidad de Barcelona el Curso de Postgrado 'Innovación en la Docencia Universitaria' dirigido al profesorado novel de la misma. Finalizado el programa se hacía imprescindible conocer su contribución a la mejora de la docencia del profesorado debutante. A través de este estudio se pretende, por tanto, identificar y valorar los cambios, transformaciones y mejoras acaecidas en la práctica docente del profesorado novel como consecuencia de su participación en el Postgrado. El presente trabajo recoge estos aspectos articulados en una evaluación diferida del impacto del Curso de Postgrado. El enfoque metodológico usado ha sido cualitativo-fenomenológico En lo que se refiere a los criterios de evaluación, dos han sido los utilizados en este estudio: la utilidad percibida por el profesorado y la transferibilidad del conocimiento elaborado en el curso.

p21 as a Transcriptional Co-Repressor of S-Phase and Mitotic Control Genes

It has been previously described that p21 functions not only as a CDK inhibitor but also as a transcriptional co-repressor in some systems. To investigate the roles of p21 in transcriptional control, we studied the gene expression changes in two human cell systems. Using a human leukemia cell line (K562) with inducible p21 expression and human primary keratinocytes with adenoviral-mediated p21 expression, we carried out microarray-based gene expression profiling. We found that p21 rapidly and strongly repressed the mRNA levels of a number of genes involved in cell cycle and mitosis. One of the most strongly down-regulated genes was CCNE2 (cyclin E2 gene). Mutational analysis in K562 cells showed that the N-terminal region of p21 is required for repression of gene expression of CCNE2 and other genes. Chromatin immunoprecipitation assays indicated that p21 was bound to human CCNE2 and other p21-repressed genes gene in the vicinity of the transcription start site. Moreover, p21 repressed human CCNE2 promoter-luciferase constructs in K562 cells. Bioinformatic analysis revealed that the CDE motif is present in most of the promoters of the p21-regulated genes. Altogether, the results suggest that p21 exerts a repressive effect on a relevant number of genes controlling S phase and mitosis. Thus, p21 activity as inhibitor of cell cycle progression would be mediated not only by the inhibition of CDKs but also by the transcriptional down-regulation of key genes.

A chromosomal insertion toolbox for promoter probing, mutant complementation and pathogenicity studies in Ralstonia solanacearum

We describe here the construction of a delivery system for stable and directed insertion of gene constructs in a permissive chromosomal site of the bacterial wilt pathogen Ralstonia solanacearum. The system consists of a collection of suicide vectors the Ralstonia chromosome (pRC) series that carry an integration element flanked by transcription terminators and two sequences of homology to the chromosome of strain GMI1000, where the integration element is inserted through a double recombination event. Unique restriction enzyme sites and a GATEWAY cassette enable cloning of any promoter::gene combination in the integration element. Variants endowed with different selectable antibiotic resistance genes and promoter::gene combinations are described. We show that the system can be readily used in GMI1000 and adapted to other R. solanacearum strains using an accessory plasmid. We prove that the pRC system can be employed to complement a deletion mutation with a single copy of the native gene, and to measure transcription of selected promoters in monocopy both in vitro and in planta. Finally, the system has been used to purify and study secretion type III effectors. These novel genetic tools will be particularly useful for the construction of recombinant bacteria that maintain inserted genes or reporter fusions in competitive situations (i.e., during plant infection).

Feedback i oportunitats de millora: una avaluació orientada a l"aprenentatge actiu

This paper analyzes an innovative experience of formative assessment aimed at improving the teaching of Statistics, which could be easily extrapolated to other studies. We detail the implementation of the double correction, consisting of correcting students' work twice. With the first correction, carried out by classmates according to a rubric developed by the academic, possible errors or deficiencies are discovered, and students are provided with a feedback that allows them to correct and improve their work before being graded by the teacher; whereas in the second correction of the work, once upgraded, the professor evaluates and grades the work. As a result, there is a significant improvement in the quality of students" works, and an active learning from their own mistakes. Both contents and competencies are reinforced by the experience.

Assessment in CLIL

The aim of this talk is to explore assessment in higher education and support for learners during their academic education. It investigates the assessment methods that provide success for universities and learners. Universities which implement CLIL should assess learners who would like to attend a programme in English without taking account of their English language qualifications. This assessment should be done in writing, listening and comprehension, speaking and reading and comprehension. In the literature, formative and summative assessments are considered. Formative assessment is ongoing, 'more complex as its intention is to be directly diagnostics with a view to immediately impacting on learner's next steps' (Coyle et al, 2010). Summative assessment occurs at the end of the term or course. McKay, 2006 divides assessment into three phases: design, operationalization and administration phase. If these three phases can't be embedded in the classroom as they are, they can be introduced as a set of questions; why?, how? and what?

International journal of engineering education

This work presents an analysis of the assessment tools used by professors at the Universitat Politécnica de Catalunya to assess the generic competencies introduced in the Bachelor’s Degrees in Engineering. In order to conduct this study, a survey was designed and administered anonymously to a sample of the professors most receptive to educational innovation at their own university. All total, 80 professors responded to this survey, of whom 26% turned out to be members of the university’s own evaluation innovation group (https://www.upc.edu/rima/grups/grapa), GRAPA. This percentage represents 47% of the total GRAPA membership, meaning that nearly half of the professors most concerned about evaluation at the university chose to participate. The analysis of the variables carried out using the statistical program SPSS v19 shows that for practically 49% of those surveyed, rubrics are the tools most commonly used to assess generic competencies integrated in more specific ones. Of those surveyed, 60% use them either frequently or always. The most frequently evaluated generic competencies were teamwork (28%), problem solving (26%), effective oral and written communication (24%) and autonomous learning (13%), all of which constitute commonly recognized competencies in the engineering profession. A two-dimensional crosstabs analysis with SPSS v19 shows a significant correlation (Asymp. Sig. 0.001) between the type of tool used and the competencies assessed. However, no significant correlation was found between the type of assessment tool used and the type of subject, type of evaluation (formative or summative), frequency of feedback given to the students or the degree of student satisfaction, and thus none of these variables can be considered to have an influence on the kind of assessment tool used. In addition, the results also indicate that there are no significant differences between the instructors belonging to GRAPA and the rest of those surveyed

University teacher competences in a virtual teaching/learning environment : analysis of a teacher training experience

This paper attempts to shed light on the competencies a teacher must have inorder to teach in online university environments. We will relate a teacher trainingexperience, which was designed taking into account the methodological criteriaestablished in line with previous theoretical principles. The main objective of ouranalysis is to identify the achievements and difficulties of a specific formativeexperience, with the ultimate goal of assessing the suitability of this conceptualmethodologicalframework for the design of formative proposals aiming to contribute tothe development of teacher competencies for virtual environments.

Assessment of research competences using e-portfolio

The challenges posed by the assessment of distance learning is a topic that requires, on the one hand, evolution with new trends and, on the other improving evaluative processes, to promote good practices. This demand becomes more imperative when we are dealing with a formativescenario based on distance assessment of competence-based learning.The Open University of Catalonia has begun to work with these formative tools, promoting new practices for online education. A very clear example of these educational practices is the assessment of research competences using the e-portfolio system. To meet this aim a profound and solid process has been developed over recent years, with the intention of making this tool an assessment alternative, and providing the opportunity to use it in a formative context. The objective is to study its strengths and limitations keeping in mind the final goal of offering the higher education community a validated assessment system.

Per una comprensió històrica de les activitats aquàtiques : una mirada educativa

Una atenta observació de les activitats aquàtiques de caire educatiu mostra que aquestes pràctiques es fonamenten, principalment, en constructes que no són propis de la pedagogia, ans provenen de l’antropologia i/o de les cultures establertes a l’entorn de l’aigua. Així, el present article es pregunta pels sentits que acompanyen aquests imaginaris que sorgeixen de la relació que s’estableix entre l’home i el medi aquàtic. Per a fer-ho, s’utilitza el recurs hermenèutic de comprendre quines han estat les pràctiques aquàtiques que han anat sorgint al llarg de la història, ja que la idea principal del treball sosté que l’activitat educativa en el medi aquàtic s’ha construït a partir dels imaginaris culturals, sorgits de les mateixes pràctiques aquàtiques que l’han precedit.