580 research outputs found

    Restrictions on the coherence of the ultrafast optical emission from an electron-hole pairs condensate

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    We report on the transfer of coherence from a quantum-well electron-hole condensate to the light it emits. As a function of density, the coherence of the electron-hole pair system evolves from being full for the low density Bose-Einstein condensate to a chaotic behavior for a high density BCS-like state. This degree of coherence is transfered to the light emitted in a damped oscillatory way in the ultrafast regime. Additionally, the photon field exhibits squeezing properties during the transfer time. We analyze the effect of light frequency and separation between electron and hole layers on the optical coherence. Our results suggest new type of ultrafast experiments for detecting electron-hole pair condensation.Comment: 4 pages,3 figures, to be published in Physical Review Letters. Minor change

    Dynamics of quantum correlations and linear entropy in a multi-qubit-cavity system

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    We present a theoretical study of the relationship between entanglement and entropy in multi-qubit quantum optical systems. Specifically we investigate quantitative relations between the concurrence and linear entropy for a two-qubit mixed system, implemented as two two-level atoms interacting with a single-mode cavity field. The dynamical evolutions of the entanglement and entropy, are controlled via time-dependent cavity-atom couplings. Our theoretical findings lead us to propose an alternative measure of entanglement, which could be used to develop a much needed correlation measure for more general multi-partite quantum systems.Comment: New discussions on the generality of entanglement-entropy relationship, one new reference, and other minor changes. 10 pages, 6 figures, accepted for publication in J.Opt. B: "Special Issue on Fluctuations & Noise in Photonics & Quantum Optics.

    Introductory teaching tool utilizing immunohistochemistry to explain the placenta

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    Introduction: The placenta occupies an important place in science, medicine, and law; yet, it remains a difficult organ to explain and understand because of its unique characteristics. Methods and Materials: A descriptive observational study was carried out on placentas. Placental components were illustrated with diagrams and corresponding microphotographs were highlighted by immunohistochemical staining to identify cell-types and structures. Results: The placenta was diagrammatically demonstrated by dividing it into chorionic plate with umbilical cord, basal plate and placental disc. In highlighting the histological components, approximately 80 immunohistochemical preparations were taken into account Conclusion: Placental complexity continues to be the critical interface for maternal-fetal dialogue. Better educational methods are needed to explain the complex pathophysiology of this essential organ. Improving placental education is the key to attracting young researchers dedicated to this field.https://orcid.org/0000-0002-7147-425Xhttps://orcid.org/0000-0002-0446-0042N/

    The mysterious extravillous trophoblast

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    Extravilluos Trophoblast (EVT) is a truly special cell. It has a temporary character and tumor-like behavior and tumor-like appearance, all of which seem to belong to the malignancy fi eld [1,2]. It is also known as intermediate trophoblast, derived from cytotrophoblast [3-5], having formed between the latter and the syncytiotrophoblast. EVT is capable of reaching the decidua through trophoblast cell columns that connect the anchoring villi to the basal plate in early gestation.https://orcid.org/0000-0002-7147-425Xhttps://orcid.org/0000-0002-0446-0042Revista Internacional - No indexadaN

    Maximally entangled mixed states of two atoms trapped inside an optical cavity

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    In some off-resonant cases, the reduced density matrix of two atoms symmetrically coupled with an optical cavity can very approximately approach to maximally entangled mixed states or maximal Bell violation mixed states in their evolution. The influence of phase decoherence on the generation of maximally entangled mixed state is also discussed. PACS numbers: 03.67.-a, 03.65.UdComment: 7 pages, 4 figures, Latex, have a major revision of content

    Standard ion transfer potential at the water|butyronitrile interface

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    Butyronitrile is an organic solvent stable enough to be used in photochemical reactions at liquid/liquid interfaces. However, it provides a rather short polarisation window making the analysis of ion transfer across the water|butyronitrile interface challenging. Here, steady-state cyclic voltammetry, at microhole-supported micro-interfaces, was used to measure Gibbs energies of transfer. A linear relationship between the standard Gibbs energies of ion partition for the water|butyronitrile interface and the water|1,2-dichloroethane and water|nitrobencene interfaces was found, making easy to extrapolate the Gibbs energy of other ions from this empiric correlation.Fil: Riva, Julieta Soledad. Swiss Federal Institute Of Technology Epfl; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Bassetto, V. C.. Swiss Federal Institute Of Technology Epfl; SuizaFil: Girault, Hubert. Swiss Federal Institute Of Technology Epfl; SuizaFil: Olaya, A. J.. Swiss Federal Institute Of Technology Epfl, Lausanne

    Emotional Intelligence in Times of Covid-19: a Comparative Study in Peruvian Universities

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    Objective:The aim of the study was to compare emotional intelligence in Peruvian university students from public and private universities.Theoretical framework: In higher education, emotionally intelligent students have the ability to interact appropriately with others, achieve good academic results, and reach personal and professional goals.Method: The methodology was descriptive-comparative, the sample consisted of 838 university students of both sexes from public (471) and private (364) universities belonging to the coast, highlands and jungle regions of Peru. A sociodemographic form created for the study and the emotional intelligence scale (TMMS-24) were used as measurement instruments.Results and conclusion:The results showed that university students over 30 years of age, women, those from the highlands and those who worked had high levels of emotional intelligence.Implications of the research:It is necessary for university institutions to reorganize their academic conditions and provide the necessary inputs to apply socioemotional strategies to students. Researchers linked to the lines of research on emotional intelligence should develop predictive studies to know which factors may be predicting adequate or inadequate emotional intelligence in university students.Originality:This study demonstrates that it is essential to attend to and provide emotional intelligence tools to those students whodo not have the necessary resources to face different situations in the face of the COVID-19 pandemic and contributes to the training of educators, especially environmental educators in crisis contexts

    Diagnostic difficulties in congenital tumor with positive antibodies for skeletal muscle. Lipofibromatosis case report

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    Neonatos con Tumores congénitos de partes blandasIntroduction: Congenital soft tissue tumors are uncommon; proper diagnosis calls for histopathological experience and ancillary techniques based upon immunohistochemial, cytogenetic, and molecular biology. Following excision, intermediately aggressive soft tumors tend to local recurrence, which significantly impacts prognosis; some cases occur close to malignity; subsequently, diagnostic implications are enormous for the patient. Case report: A 26-day old neonate with a posterior left thigh mass entered hospital. Initial biopsy analysis could not rule out either striated muscle origin or malignancy; resection and classification of surgical piece followed. Pursuant to resection, using immunohistochemistry panel, tumor analysis and classification took place. Conclusion: Soft tumor diagnosis is a complex process, even more so for newborns. Infrequent occurrence requires that examiners have ample histopathological experience in the handling of ancillary techniques. Furthermore, as in lipofibromatosis, determining the presence of trapped vs. malignant tissue hinders proper classification, which, in turn, has profound implications for the patient. We include a standard diagnostic algorithm based on clinical and histological characteristics for this type of congenital lesions.https://orcid.org/0000-0003-3507-7596https://orcid.org/0000-0001-8932-4877https://orcid.org/0000-0002-7147-425Xhttps://orcid.org/0000-0001-7982-4552Revista Internacional - No indexadaN

    Optical signatures of quantum phase transitions in a light-matter system

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    Information about quantum phase transitions in conventional condensed matter systems, must be sought by probing the matter system itself. By contrast, we show that mixed matter-light systems offer a distinct advantage in that the photon field carries clear signatures of the associated quantum critical phenomena. Having derived an accurate, size-consistent Hamiltonian for the photonic field in the well-known Dicke model, we predict striking behavior of the optical squeezing and photon statistics near the phase transition. The corresponding dynamics resemble those of a degenerate parametric amplifier. Our findings boost the motivation for exploring exotic quantum phase transition phenomena in atom-cavity, nanostructure-cavity, and nanostructure-photonic-band-gap systems.Comment: 4 pages, 4 figure

    Immune Response to Newcastle Disease Virus Vaccination in a Wild Passerine

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    We studied the immune response of wild House Sparrows (Passer domesticus) experimentally challenged with different doses of inactivated Newcastle disease virus (NDV) vaccine. We evaluated within-individual cell-mediated and humoral responses in birds kept in outdoor aviaries, over a 6-wk period. Nonbreeding adult House Sparrows developed a significant humoral response to NDV experimental vaccination within 1 wk postchallenge, as measured by hemagglutination inhibition assay; values increased until week 4 and persisted until week 6. Differences among treatments appeared by week 1, with individuals challenged with the highest dose (0.2 mL) eliciting a higher humoral response than the rest (n = 18). By week 4, all individuals vaccinated displayed an increased humoral response, with individuals challenged with the highest dose remaining significantly above responses of individuals vaccinated with the middle dose (0.1 mL, n = 14), but not the lowest dose (0.05 mL, n = 15). The middle and lowest dose responded similarly and significantly different from controls (n = 23). Differences persisted through week 6 postchallenge. Cell-mediated responses were independent of the experimental treatment. All individuals experienced a rise in granulocyte concentration, whereas lymphocyte and monocyte concentrations decreased, most likely as a result of captivity. Adult wild House Sparrows immunochallenged with inactivated NDV vaccine developed a specific humoral response, highlighting the utility of this technique in immunologic and evolutionary ecology studies in wild birds.Peer reviewe
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