Search results for "COPI"
showing 10 items of 2618 documents
High accuracy Raman measurements using the Stokes and anti-Stokes lines
1997
We show that by measuring the separation between the Stokes and anti-Stokes peaks excited by two different laser lines we obtain a very precise determination of absolute phonon energies. The method is useful for measuring small changes of these energies with strain, temperature, laser power, etc. It doubles the changes and avoids the necessity of using the reference lines in the Raman spectra. The method can be applied for the determination of phonon deformation potentials, for the characterization of strained heteroepitaxial layers, and for micro-Raman analysis of strain in silicon integrated circuits. We give examples of phonon shifts in Si, Ge, GaAs, InAs, and GaP as a function of applie…
Optical switching of quantum states inside self-assembled quantum dots
2008
Abstract Photoluminescence and excitation of photoluminescence spectroscopy have been performed for two kinds of single InAs self-assembled quantum dots grown on GaAs. The presence of unintentional impurities (donors and acceptors) offers the possibility to switch from negative to positively charged excitons by selectively exciting impurity related optical transitions.
Isolated self-assembled InAs/InP(001) quantum wires obtained by controlling the growth front evolution
2007
6 páginas, 5 figuras. In this work we explore the first stages of quantum wire (QWR) formation studying the evolution of the growth front for InAs coverages below the critical thickness, θc, determined by reflection high energy electron diffraction (RHEED). Our results obtained by in situ measurement of the accumulated stress evolution during InAs growth on InP(001) show that the relaxation process starts at a certain InAs coverage θRθR this ensemble of isolated nanostructures progressively evolves towards QWRs that cover the whole surface for θ = θc. These results allow for a better understanding of the self-assembling process of QWRs and enable the study of the individual properties of In…
The management of the slow transit constipation in the laparoscopic era
2018
The slow transit constipation (STC) is a functional bowel pathology with slow total gut transit time with normal calibre colon in addition to a variety of other systemic symptoms. Patients with an abnormal colonic motility refractory to conservative treatment are regarded as appropriate candidates for surgery. Laparoscopic total colectomy with ileum-rectum anastomosis represents the commonest surgical operation in the treatment of STC, in well selected patients, after failure of conservative treatment. From 2012 to 2016, 8 patients suffering constipation according to Roma III criteria and diagnosed as STC were submitted to a total colectomy in our O.U. We evaluated the long-term post-operat…
Diagnostic validity of the Merrill Palmer-R Development Scale used in the evaluation of access to Child Development Centers and Early Care
2019
The Merrill Palmer-R Development Scale is commonly used in Child Development and Early Care Centers. It is usually used, like other scales, in the initial evaluation process at the time of discharge in the center and / or throughout the entire intervention. The results obtained in the application of the scale are presented in the University Center of Diagnostic and Early Care of the University of Valencia, in the period between 2011 and 2016. In total, 223 cases of children under 42 months have been analyzed. Most of them, or without diagnosis or with a provisional diagnosis at the time of discharge. The objective of this article is to determine the diagnostic value of the Merrill Palmer-R …
El síndrome del cromosoma X Frágil: fenotipo conductual y dificultades de aprendizaje
2015
In this article, we describe the behavioral phenotype of individuals with Fragile X Syndrome and its impact in the educational scope. This syndrome is characterized by difficulties in sensory integration, cognitive deficits (verbal reasoning, abstract/ visual and cuantitative skills, short term memory, sequential processing, attention and executive processes), language disorders (phonetic-phonologicals, semanticals, morphosyntacticals and pragmaticals) and communication disorders, social anxiety, general hyperarousal, autism, non autistic social difficulties, attention deficit and hyperactivity, and learning disabilities. The behavioral phenotype is highly variable and depends on sex, age, …
L’anxiété de performance dans l’enseignement musical. Une revue de littérature
2022
How might music teachers help their students cope with the anxiety-provoking aspects of public performance? This article aims to provide some elements to answer this question. It is important to consider that public performance is one of the main aspects of musical practice from the start of the learning process. Given the high prevalence of music performance anxiety—MPA among musicians of all levels and ages, the teacher has an important role. Based on a literature review, the sources of MPA are analyzed and, for each of them, strategies that could be used by a music teacher are indicated. Emphasis is placed on prevention and on the importance of raising music teachers’ awareness of MPA.
Do social comparison and coping styles play a role in the development of burnout? Cross-sectional and longitudinal findings
2006
The present longitudinal research among 558 teachers focused on the role of upward comparisons (with others performing better), downward comparisons (with others performing worse), and coping styles in relation to burnout. Assessed were identification (recognizing oneself in the other) and contrast (seeing the other as a competitor) in upward and downward comparison. Cross-sectionally, downward identification and upward contrast were positively related to burnout and negatively related to a direct coping style, whereas upward identification was negatively related to burnout and positively related to a direct coping style. Downward identification was positively related to a palliative coping…
Individual Differences in the Psychobiological Response to Psychosocial Stress (Trier Social Stress Test): The Relevance of Trait Anxiety and Coping …
2014
The main objective of this study was to investigate the contribution of some personality traits to the physiological and psychological response to a standardized laboratory psychosocial stressor (trier social stress test). Cortisol and affective response (anxiety and mood) were analysed in a mixed-sex group composed of 35 young adults who participated in a crossover design (18 men and 17 women). After verifying a statistically significant response to the trier social stress test in all parameters studied in both sex groups, exploratory cluster analyses were carried out to identify sub-groups based on their psychophysiological responses. These analyses showed two different groups: subjects d…
Coping with competition: neuroendocrine responses and cognitive variables.
2008
Confronting another individual or group motivated by the same goal is a very frequent situation in human communities that occurs in many other species. Competitive interactions emerge as critical situations that shed light on the effects and consequences of social stress on health. But more important than the situation itself is the way it is interpreted by the subject. This "appraisal" involves cognitive processes that contribute to explaining the neuroendocrine response to these interactions, helping to understanding the vulnerability or resistance to their effects. In this review, we defend the need to study human competition within the social stress framework, while maintaining an evolu…