Selection of Algerian medicinal plants according to a screening of their anti-AGEs properties

International audienc

The role of the cerebellum in adaptation: ALE meta‐analyses on sensory feedback error

It is widely accepted that unexpected sensory consequences of self‐action engage the cerebellum. However, we currently lack consensus on where in the cerebellum, we find fine‐grained differentiation to unexpected sensory feedback. This may result from methodological diversity in task‐based human neuroimaging studies that experimentally alter the quality of self‐generated sensory feedback. We gathered existing studies that manipulated sensory feedback using a variety of methodological approaches and performed activation likelihood estimation (ALE) meta‐analyses. Only half of these studies reported cerebellar activation with considerable variation in spatial location. Consequently, ALE analyses did not reveal significantly increased likelihood of activation in the cerebellum despite the broad scientific consensus of the cerebellum's involvement. In light of the high degree of methodological variability in published studies, we tested for statistical dependence between methodological factors that varied across the published studies. Experiments that elicited an adaptive response to continuously altered sensory feedback more frequently reported activation in the cerebellum than those experiments that did not induce adaptation. These findings may explain the surprisingly low rate of significant cerebellar activation across brain imaging studies investigating unexpected sensory feedback. Furthermore, limitations of functional magnetic resonance imaging to probe the cerebellum could play a role as climbing fiber activity associated with feedback error processing may not be captured by it. We provide methodological recommendations that may guide future studies

Електричне дослідження структур Au/GaN/GaAs (100) як функції частоти

Різні дослідження показують, що нітрування поверхні GaAs покращує електричну якість діодів Шотткі на основі арсеніду галію. Для того, щоб спостерігати це покращення, були досліджені характеристики ємність/провідність-напруга на трьох частотах (50, 100 та 500 кГц). Ці характеристики були кореговані шляхом усунення ефекту послідовного опору. Спочатку визначали значення послідовного опору та будували графік його залежності від напруги на різних частотах. Отримані криві показують значні значення послідовного опору з піками, які спостерігаються при близько – 0,5 В для частот 50 і 100 кГц і при 0,25 В для 500 кГц. Ці піки пов'язані з омічним зворотним контактом і щільністю поверхневих станів. Потім були розраховані електричні властивості виготовленого діода Шотткі та оцінена щільність поверхневих станів діода Шотткі з ефектом послідовного опору та без нього. Щільність поверхневих станів значно зменшилася після усунення ефекту послідовного опору. Електричні параметри демонструють покращення електричної якості виготовленого діода Шотткі Au/GaN/GaAs.Various studies show that the nitridation of the GaAs surface improves the electrical quality of the Schottky diodes based on gallium arsenide. In order to observe this improvement, capacitance/conductance – voltage characteristics were investigated at three frequencies (50, 100 and 500 kHz). These characteristics were corrected by eliminating the effect of the series resistance. First, values of the series resistance were determined and plotted against voltage at different frequencies. The obtained curves show significant values of the series resistance with peaks observed at about – 0.5 V for 50 and 100 kHz frequencies and at 0.25 V for 500 kHz. These peaks are attributed to the ohmic back contact and the surface state density. The electrical properties of the fabricated Schottky diode were then calculated and the surface state density of the Schottky diode was estimated with and without the effect of the series resistance. Surface state density was significantly reduced after the elimination of the series resistance effect. Electrical parameters demonstrate an improvement of the electrical quality of the fabricated Au/GaN/GaAs Schottky diode

Study and characterization of the structures Au/Al2O3/Si and Au/Al0/Al2O3/Si

International audienc

Study of the surface state density and potential in MIS diode Schottky using the surface photovoltage method

International audienc

Analysis of C-V Characteristics of InP(p)/InSb/Al₂O₃/Au MIS Structures in Wide Temperature Range

International audienc

Nitridation of InP(100) substrates studied by XPS spectroscopy and electrical analysis

International audienc

Effects of the GaN layers and the annealing on the electrical properties in the Schottky diodes based on nitrated GaAs

International audienc

Electrical Characterization and Electronic Transport Modelization in the InN/InP Structures

International audienc