1,721,017 research outputs found
Weak and strong coupling for quantum boxes in pillar microcavities
No full textThe interaction of a quantum box with the vacuum field inside a semiconductor pillar microcavity is theoretically investigated by means of a master equation approach accounting also for incoherent relaxation processes. We show that both exciton and biexciton states bound to monolayer fluctuations in narrow quantum wells can be in strong coupling. Finally, we calculate the luminescence spectrum and we explain its structures in terms of transitions between dressed states
Strong coupling and dressed states of an interface island in a pillar semiconductor microcavity
No full textWe present a theoretical scheme to investigate the coupled states of a zero-dimensional semiconductor structure and the confined modes of a pillar microcavity, taking into account interacting exciton states and both coherent and incoherent dynamical processes. For quantum-well monolayer fluctuations we find that the frequency of the cavity modes can be tuned in such a way that both exciton and biexciton states are in the strong coupling regime. The calculated luminescence spectra are interpreted in terms of transitions between the dressed states of the composite radiation-matter system
Self-induced transparency in semiconductor quantum dots
No full textWe present a theoretical analysis of self-induced transparency in a sample of inhomogeneously broadened semiconductor quantum dots. A general theoretical framework accounting for mutual light-matter interactions in the presence of single and biexciton transitions is presented. Numerical results demonstrate that intense light pulses can propagate in realistic state-of-the-art dot samples without suffering strong losses
First Evidence of Placental Transfer of Ochratoxin A in Horses
No full textOchratoxin A (OTA) is a renal mycotoxin and transplacental genotoxic
carcinogen. The aim of this study was to evaluate the natural occurrence of OTA in equine
blood samples and its placental transfer. For the assessment of OTA levels, serum samples
were collected from 12 stallions, 7 cycling mares and 17 pregnant mares. OTA was found
in 83% of serum samples (median value = 121.4 pg/mL). For the assessment of placental
transfer, serum samples were collected from the 17 mares after delivery and from the
umbilical cords of their foals, after foaling. Fourteen serum samples from pregnant mares
contained OTA (median value = 106.5 pg/mL), but only 50% of their foals were exposed
(median values = 96.6 pg/mL). HPLC analysis carried out on four serum samples
(collected from two mares and their respective foals) supported the ELISA results on OTA
placental transfer. This is the first report on the natural occurrence of OTA in horse serum
samples and placental transfer in horses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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