Search results for " Seconda"
showing 10 items of 975 documents
Detergent Properties Influence the Stability of the Glycophorin A Transmembrane Helix Dimer in Lysophosphatidylcholine Micelles
2012
AbstractDetergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and fine-tuning detergent properties can be crucial for obtaining structural information of intact and functional transmembrane proteins. To systematically investigate the influence of the detergent concentration and acyl-chain length on the stability of a transmembrane protein structure, the stability of the human glycophorin A transmembrane helix dimer has been analyzed in lyso-phosphatidylcholine micelles of different acyl-chain length. While our results indicate that the transmembrane protein is destabilized in detergents w…
Early Antecedents of School Burnout in Upper Secondary Education : A Five-year Longitudinal Study
2020
AbstractSchool burnout symptoms are prevalent among upper secondary education students, but thus far, very little is known about the background of these symptoms. The present study examined the extent to which school burnout symptoms (i.e., exhaustion and cynicism) among upper secondary education students have their roots in primary and lower secondary school and whether early antecedents of school burnout symptoms could be identified. The sample consisted of 1544 Finnish students followed up four times (Time1–Time 4) from the end of primary school (T1; mean age 12.74 and range 11.71–14.20) to the first year of upper secondary education (T4; mean age 16.66 and range 15.55–18.39). The result…
Le devenir professionnel des élèves sortis des classes de BEPA
1985
Understanding of Mendelian Inheritance Model after conventional teaching methods in Secondary Education students
2015
Mostrar que una nueva propuesta de enseñanza produce mejores actitudes y aprendizajes en los alumnos requiere disponer de un análisis de lo que se hace y se consigue con la enseñanza habitual. Para realizar dicho análisis se ha efectuado un estudio histórico y epistemológico de la evolución de las ideas en genética clásica, identificando los problemas que están en su origen, las ideas que permitieron avanzar y los obstáculos que hubo que superar. Como resultado de dicho estudio se han seleccionado un conjunto de indicadores de aprendizaje que deberían manifestarse en aquellas personas que hubieran comprendido los aspectos esenciales del modelo de herencia mendeliana, que se imparte en 4º de…
Italian and Spanish Students Perception on Use of Technology in Classrooms of Classics in Secondary School
2019
A society that is becoming increasingly digital must explore new ways of learning. In fact, digital technologies have an impact on the education through the development of more flexible learning environments adapted to the needs of a high-mobility society. To prepare future citizens to the needs of the digital labor market, recent educational reforms in Italy and Spain focused their attention on students' Digital Competences. Therefore, we are interested in probing how students of classical studies in Italian and Spanish high schools perceive the use of new technologies in the classroom. It is important to investigate classics at school, because traditionally this program is perceived as le…
Dual-affinity avidin molecules
2005
A recently reported dual-chain avidin was modified further to contain two distinct, independent types of ligand-binding sites within a single polypeptide chain. Chicken avidin is normally a tetrameric glycoprotein that binds water-soluble d-biotin with extreme affinity (Kd ≈ 10−15M). Avidin is utilized in various applications and techniques in the life sciences and in the nanosciences. In a recent study, we described a novel avidin monomer-fusion chimera that joins two circularly permuted monomers into a single polypeptide chain. Two of these dual-chain avidins were observed to associate spontaneously to form a dimer equivalent to the wt tetramer. In the present study, we successfully used …
Unfolding a transmembrane helix dimer: A FRET study in mixed micelles
2009
The exact nature of membrane protein folding and assembly is not understood in detail yet. Addition of SDS to a membrane protein dissolved in mild, non-polar detergent results in formation of mixed micelles and in subsequent denaturation of higher ordered membrane protein structures. The exact nature of this denaturation event is, however, enigmatic, and separation of an individual helix pair in mixed micelles has also not been reported yet. Here we followed unfolding of the human glycophorin A transmembrane helix dimer in mixed micelles by fluorescence spectroscopy. Energy transfer between differently labelled glycophorin A transmembrane helices decreased with increasing SDS mole fractions…
Perron's method for the porous medium equation
2016
O. Perron introduced his celebrated method for the Dirichlet problem for harmonic functions in 1923. The method produces two solution candidates for given boundary values, an upper solution and a lower solution. A central issue is then to determine when the two solutions are actually the same function. The classical result in this direction is Wiener’s resolutivity theorem: the upper and lower solutions coincide for all continuous boundary values. We discuss the resolutivity theorem and the related notions for the porous medium equation ut −∆u = 0
Almost disjoint families of countable sets and separable complementation properties
2012
We study the separable complementation property (SCP) and its natural variations in Banach spaces of continuous functions over compacta $K_{\mathcal A}$ induced by almost disjoint families ${\mathcal A}$ of countable subsets of uncountable sets. For these spaces, we prove among others that $C(K_{\mathcal A})$ has the controlled variant of the separable complementation property if and only if $C(K_{\mathcal A})$ is Lindel\"of in the weak topology if and only if $K_{\mathcal A}$ is monolithic. We give an example of ${\mathcal A}$ for which $C(K_{\mathcal A})$ has the SCP, while $K_{\mathcal A}$ is not monolithic and an example of a space $C(K_{\mathcal A})$ with controlled and continuous SCP …
L'aide individualisée en seconde, mise en route et premiers effets d'une innovation pédagogique
2001
International audience; A la suite de la première année de fonctionnement, le dispositif d'aide individualisée en seconde s'est révélé comme étant peu efficace sur les résultats scolaires des élèves. Le caractère peu ciblé du dispositif, une incohérence relative dans l'allocation des moyens aux établissements, le faible nombre de séances suivies par les élèves sont des éléments qui peuvent sans doute expliquer ce résultat décevant de l'évaluation d'une innovation récente qui devrait évoluer.