Search results for "GPA"

Structural contacts in subduction complexes and their tectonic significance: the Late Palaeozoic coastal accretionary wedge of central Chile

2007

Understanding the contact between the very low-grade metagreywacke of the Eastern Series and high-pressure metamorphosed schist of the Western Series in the Late Palaeozoic accretionary wedge of central Chile is fundamental for the understanding of the evolution of ancient accretionary wedges. We show the progressive development of structures and finite strain from the least deformed rocks in the eastern part of the Eastern Series of the accretionary wedge to high-pressure schist of the Western Series at the Pacific coast. Upright chevron folds of sedimentary layering are associated with an axial-plane foliation, S1. As the F1 folds became slightly overturned to the west, S1 was folded abou…

Transmembrane signaling and cytoplasmic signal conversion by dimeric transmembrane helix 2 and a linker domain of the DcuS sensor kinase

2020

Transmembrane (TM) signaling is a key process of membrane-bound sensor kinases. The C4-dicarboxylate (fumarate) responsive sensor kinase DcuS of Escherichia coli is anchored by TM helices TM1 and TM2 in the membrane. Signal transmission across the membrane relies on the piston-type movement of the periplasmic part of TM2. To define the role of TM2 in TM signaling, we use oxidative Cys cross-linking to demonstrate that TM2 extends over the full distance of the membrane and forms a stable TM homodimer in both the inactive and fumarate-activated state of DcuS. An S186xxxGxxxG194 motif is required for the stability and function of the TM2 homodimer. The TM2 helix further extends on the periplas…

7-ketocholesterol and 7β-hydroxycholesterol: in vitro and animal models used to characterize their activities and to identify molecules preventing th…

2020

International audience; Oxysterols are molecules derived by the oxidation of cholesterol and can be formed either by auto-oxidation, enzymatically or by both processes. Among the oxysterols formed by auto-oxidation, 7-ketocholesterol and 7beta-hydroxycholesterol are the main forms generated. These oxysterols, formed endogenously and brought in large quantities by certain foods, have major cytotoxic properties. They are powerful inducers of oxidative stress, inducing dysfunction of organelles (mitochondria, lysosomes and peroxisomes) that can cause cell death. These molecules are often identified in increased amounts in common pathological states such as cardiovascular diseases, certain eye …

Determinantes estructurales del plegamiento y la interacción entre fragmentos transmembrana

2003

El análisis de secuencias genómicas completas de diversos organismos muestra que, aproximádamente, un 20-30% de las pautas de lectura abierta codifica para proteínas que atraviesan la membrana (Arkin, Brunger et al. 1997) (Wallin and von Heijne 1998). Sin embargo el medio en que estas proteínas adoptan su estructura nativa y desarrollan su función, la membrana, ha dificultado la aplicación directa de las técnicas de estudio habituales para proteínas solubles. Esta dificultad se refleja en el hecho de que en la era de la explosción de obtención de estructuras proteícas de alta resolución, se limita a unas docenas el número de proteínas de membrana resueltas. En este trabajo se…

Crystal structure of sinhalite MgAlBO4 under high pressure

2015

We report on high-pressure angle-dispersive X-ray diffraction data up to 27 GPa for natural MgAlBO4 sinhalite mineral and ab initio total energy calculations. The experimental bulk modulus of sinhalite is B-0 = 171(3) GPa with a first-pressure derivative of B-0' = 4.2(3). A comparison with other olivine-type compounds shows that the value for B0 is 27% larger than that of Mg2SiO4 forsterite and 29% smaller than that of Al2BeO4 chrysoberyl. These differences are interpreted, on the basis of our ab initio calculations, in terms of the relative incompressibility of Al-O bonds in AlO6 octahedra (with a calculated bulk modulus of 250(1) GPa) as compared to Mg-O bonds in MgO6 octahedra (with a ca…

Adozione in casi particolari e rapporti di parentela tra adottato e famiglia dell'adottante secondo la Corte costituzionale

2022

Il contributo considera le ricadute della sentenza n. 79/2022 della Corte costituzionale sulle due figure dell'adozione piena e dell'adozione in casi particolari dei minori di età con particolare riferimento alla posizione del bambino adottato in casi particolari e dei legami con la famiglia di origine e con quella del/gli adottante/i. Evidenziate talune aporie del ragionamento della Consulta, riflette criticamente sulla bontà del ricorso all'adozione in casi particolari per dare copertura giuridica al legame tra il genitore d'intenzione non biologico e il nato da gestazione per altri, specie in caso di omogenitorialità, in vista del perseguimento del migliore interesse del minore.

Further considerations on a new indicator for higher education student performance

2016

Il presente lavoro si inserisce nel dibattito internazionale sul sistema di voto universitario e sulla sua sintesi come misura della performance di uno studente. Partendo dalla nuova misura proposta in Adelfio et al. (2014), in questo breve articolo si pone l’enfasi sull’importanza della scelta della misura opportuna, soprattutto nella individuazione delle possibili determinanti della performance, utile nella scelte delle opportune politiche di intervento sulla performance della carriera dello studente. Per richiamare il nuovo indicatore proposto e per fare il confronto con quello esistente, si `e fatto riferimento ai Sistema Universitario italiano. This paper joins the international debate…

Novel Methodologies to Model Charge Transport in Metal-Air Batteries

2018

A new indicator for higher education student performance

2014

The debate on academic achievement is a heated issue that involves all the higher education contexts. This paper attempts to provide an indicator that can make the measurement of university student performance easier and that can be easily applied to different systems, making comparisons more fair. The Italian University System is used as a starting point to make several considerations on the current measures and to build up a new performance indicator. Then, a generalization for other marking systems is shown and finally a quantile regression is performed to investigate some determinants of the new performance indicator, also with respect to the current one.

The membrane environment modulates self-association of the human GpA TM domain--implications for membrane protein folding and transmembrane signaling.

2010

Abstract The influence of lipid bilayer properties on a defined and sequence-specific transmembrane helix–helix interaction is not well characterized yet. To study the potential impact of changing bilayer properties on a sequence-specific transmembrane helix–helix interaction, we have traced the association of fluorescent-labeled glycophorin A transmembrane peptides by fluorescence spectroscopy in model membranes with varying lipid compositions. The observed changes of the glycophorin A dimerization propensities in different lipid bilayers suggest that the lipid bilayer thickness severely influences the monomer–dimer equilibrium of this transmembrane domain, and dimerization was most effici…