Nestings of rational homogeneous varieties

In this paper we study the existence of sections of universal bundles on rational homogeneous varieties -- called nestings -- classifying them completely in the case in which the Lie algebra of the automorphism group of the variety is simple of classical type. In particular we show that, under this hypothesis, nestings do not exist unless there exists a proper algebraic subgroup of the automorphism group acting transitively on the base variety.Comment: Major revision of the exposition. To appear in Tranformation Group

Critical Translingual Perspectives on California Multilingual Education Policy

Policies restricting bilingual education have yielded to policy frameworks touting its benefits. This shift corresponds with evolving lines of debate, focusing now on how bilingual education can best support racialized bilingual learners. One element of this new debate is the perspective on language underlying curriculum in bilingual programs, with a focus on translanguaging– normalization of the language practices of bilingual communities and positing that bilinguals draw from a singular linguistic repertoire. This article examines initiatives undertaken in California between 2010 and 2019 using Critical Policy Analysis. The work highlights that while opportunities for translanguaging have arisen, tensions between heteroglossic perspectives and the impulses toward standardization and commodification of language undermine such possibilities, and that notable gaps remain between teacher preparation frameworks and intended pedagogical practice

Ab initio LSDA and LSDA+U study of pure and Cd-doped cubic lanthanide sesquioxides

The electronic, structural, and hyperfine properties of pure and Cd-doped lanthanide (Ln) sesquioxides with the cubic bixbyite structure (Ln2O3, Ln ranging from La to Lu) have been studied using the full-potential augmented plane wave plus local orbital (APW + lo) method within the local spin density approximation (LSDA) and the Coulomb-corrected LSDA + U. In the case of the pure systems, our calculations show that LSDA + U gives a better representation of the band structure compared to LSDA. The predicted equilibrium structures and the electric field gradient (EFG) tensor at Ln sites were calculated and compared with those obtained by means of hyperfine techniques and with theoretical results obtained in In2O3, Sc2O3, and Lu2O3 reported in the literature. The origin of the EFG at Ln sites and the role played by the 4f electrons on this quantity are discussed. In the case of the Cd-doped systems, the APW + lo method (also within LSDA and LSDA + U) was applied to treat the electronic structure of the doped system. The role of the Ln 4f electrons on the EFG at Cd impurity sites, and other variables like structural distortions induced by the Cd impurity, were investigated in detail and are discussed and compared with available experimental results. An excellent agreement between the experimental and calculated EFGs was found for all Cd-doped systems.Fil: Richard, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Muñoz, Emiliano Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Rentería, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Errico, Leonardo Antonio. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Svane, A.. University Aarhus. Institut for Fysik Og Astronomi; DinamarcaFil: Christensen, N. E.. University Aarhus. Institut for Fysik Og Astronomi; Dinamarc

Remifentanilo versus propofol con infusión controlada a objetivo en sitio efecto para la sedación de pacientes durante procedimientos endoscópicos gastrointestinales: ensayo clínico controlado aleatorizado

Background: Target controlled infusion (TCI) for the administration of anesthesia may provide a safe alternative for managing the discomfort of patients undergoing gastrointestinal endoscopic procedures. However, the most appropriate drug available for TCI is yet to be established. The objective of this trial was to compare remifentanil vs. propofol in TCI for sedating patients during GI endoscopy. Materials and methods: Sixty-nine patients requiring GI endoscopies were randomly distributed to receive remifentanil (n = 30) or propofol (n = 39) TCI at the effect site (e). The primary outcome was patient's satisfaction. Secondary outcomes included the gastroenterologist satisfaction, comparison of the percentage of adverse events between the two groups (occurrence of arrhythmias, major respiratory depression, bradycardia, hypotension, pain, nausea or vomiting and absence of amnesia), and the level of awareness. Retrospective registration number is NCT01746641 at Clinicaltrias.gov Results: The mean (range) of patient satisfaction with remifentanil vs propofol was 1 (1-2) and 2 (11), respectively (Chi2, p < 0.001). Pain during the procedure was found to differ between remifentanil and propofol (mean 2 vs. 1, Chi2, p = 0.042), nausea or vomiting (4 vs. 0, Chi2, p = 0.01), and absence of amnesia (29 vs. 10, Chi2, p < 0.001), respectively. No statistically significant differences were found between the two groups. Conclusion: Propofol in TCI seems to be an adequate agent for sedation of patients undergoing GI endoscopic procedures, with less adverse effects and higher patient satisfaction. Most likely, the combination of these two drugs may be synergistic and further reduce any adverse effects

Rank two Fano bundles on G(1,4)

We classify rank two Fano bundles over the Grassmannian of lines \G(1,4). In particular we show that the only non-split rank two Fano bundle over \G(1,4) is, up to a twist, the universal quotient bundle \cQ. This completes the classification of rank two Fano bundles over Grassmannians of lines

Adolescents problematic mobile phone use, Fear of Missing Out and family communication / Uso problemático del móvil, fobia a sentirse excluido y comunicación familiar de los adolescentes

This research analyzes the problematic use of mobile phone, the phenomenon of fear of missing Out (FoMO) and the communication between parents and children in students who attend secondary education in public and private centers of the regions of Canary Islands, Balearic Islands and Valencia. The research involved 569 students aged between 12 and 19 years. The instruments used were the «Mobil phone related experiences questionnaire», the Spanish adaptation of the «Fear of missing out questionnaire» and the communication dimension with parents of the «Parents and peers attachment inventory». The results show that: 1) An increased problematic use of the mobile phone is associated with a higher level of FoMO; 2) The students who frequently use the mobile phone and communicate more with their friends have a higher average score in the «Mobile phone related experiences questionnaire» and in the «Fear of missing out questionnaire»; 3) The students that use the mobile phone for less time has a greater communication with fathers and mothers. We discuss the relevance of the study of FoMO and parents-children communication as factors that affect the problematic use of mobile phone in young people. Centers’ guidance teams, families and teachers have to create a common learning space to promote the responsible use of mobile phone

Aggregated NETs Sequester and Detoxify Extracellular Histones

In response to various infectious and sterile stimuli neutrophils release chromatin decorated with bactericidal proteins, referred to as NETs. Their scaffolds are formed from chromatin fibers which display an apparent diameter of 15–17 nm and mainly consist from DNA (2 nm) and DNA-associated histones (11 nm). The NET-forming strands are thus not naked DNA but higher ordered chromatin structures. The histones may be released from the NET, especially if their tail arginines have been citrullinated. Several studies indicate that extracellular histones are toxic for mammalian epithelia and endothelia and contribute to the microvascular dysfunction observed e.g., in patients suffering from autoimmune diseases or sepsis. NETs formed at sites of very high neutrophil densities tend to clump and form fairly stable enzymatically active aggregates, referred to as aggNETs. The latter are endowed with a bunch of enzymes that cleave, bind, and/or modify autologous as well as foreign macromolecules. The tight binding of the serine proteases to the matrix precludes the spread of these toxic enzymes into the tissue but still allows the access of soluble inflammatory mediators to the enzymatic active internal surfaces of the NETs where they are degraded. Here, we describe that externally added histones are removed from culture supernatants of aggNETs. We will address the fate of the histones and discuss the feature on the background of neutrophil-driven diseases and the resolution of inflammation

Neisseria gonorrhoeae challenge increases matrix metalloproteinase-8 expression in fallopian tube explants

Indexación: Scopus.Background: Neisseria gonorrhoeae (Ngo) is the etiological agent of gonorrhea, a sexually transmitted infection that initially infects the female lower genital tract. In untreated women, the bacteria can ascend to the upper genital reproductive tract and infect the fallopian tube (FTs), which is associated with salpingitis and can lead to impaired FT function and infertility. The extracellular matrix (ECM) plays an important role in cell migration and differentiation in the female genital tract, and some pathogens modify the ECM to establish successful infections. The ECM is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), their endogenous inhibitors; MMP deregulation causes pathological conditions in a variety of tissues. Results: The aim of this work was to analyze the expression and localization of MMP-3, MMP-8, MMP-9, and TIMP-1 in FT explants during Ngo infection using real-time PCR, immunohistochemistry, zymography and ELISA. No significant variations in MMP-3, MMP-9, and TIMP-1 transcript levels were observed. In contrast, a significant increase (p < 0.05) was observed for MMP-8 expression and was accompanied by stromal immunoreactivity in infected explants. ELISA results supported these findings and showed that MMP-8 release increased upon gonococcal infection. Conclusions: Our results indicate that gonococcal infection induces increased MMP-8 expression, which might contribute to FT damage during infection. © 2017 Juica, Rodas, Solar, Borda, Vargas, Muñoz, Paredes, Christodoulides and Velasquez.https://www.frontiersin.org/articles/10.3389/fcimb.2017.00399/ful

Radiation damage evaluation on AlGaAs/GaAs solar cells

A computer model to evaluate radiation damage on AlGaAs-based solar cells is reported. The model is based on a piecewise approach that divides the cell structure in an adaptive number of slices. Inside a particular slice the semiconductor parameters are constant; consequently, it is easy to find an analytical solution of the semiconductor transport equations with suitable boundary conditions for the interfaces with the adjacent slices. The model provides all electrical parameters of the cells in the operating temperature range. Different structures, including graded band gaps and double heterofaces can be analyzed. Proton damage coefficients as well as proton damage ratios can be calculated for energies between 30 and 10/sup 4/ keV with only two adjustable parameters. Coirradiation experiments with different energy protons were simulated by improving the conventional method of degradation computering.Peer ReviewedPostprint (published version