Preparing Bilingual Teachers to Enact Culturally Sustaining Pedagogy

Bilingual students and teachers in the U.S. live in a context where linguistic and ethnic minorities are associated with inferiority. Preparing bilingual teachers of color without explicit attention to issues of race, language, and power would maintain and feed the vicious cycle of linguistic hegemony. With the goal of preparing critically conscious future bilingual teachers equipped to enact culturally sustaining pedagogy (CSP), the authors centered issues of race, language, and power alongside bilingual instructional methodology and theories of bilingualism in their respective bilingual teacher preparation programs. Drawing on bilingual teacher preparation course material, student reflections, and bilingual teacher candidate interviews, they illustrate how two bilingual teacher preparation programs take two distinct approaches to developing bilingual teachers\u27 critical consciousness and CSP practices. In this way, they outline how bilingual teacher educators can prepare and support bilingual teachers to enact CSP with their K-12 students

Radiation-damage produced in BaHfO₃ irradiated with thermal and fast-neutrons

Samples of BaHfO₃ were irradiated with fast and thermal neutrons to produce ^181Hf. Attenuations of the gamma-gamma perturbed angular correlations in ^181Ta were observed, and they may have been caused by the interaction between defects (produced during or after neutron irradiation) and oxygen vacancies. Several defect structures were detected. For one of the structures, an excitation energy of 12 meV was measured, which was attributed to an electron state below the conduction band. The values of the dielectric constant and of the effective electron mass were also deduced

Fossil Groups Origins III. Characterization of the sample and observational properties of fossil systems

(Abridged) Fossil systems are group- or cluster-sized objects whose luminosity is dominated by a very massive central galaxy. In the current cold dark matter scenario, these objects formed hierarchically at an early epoch of the Universe and then slowly evolved until present day. That is the reason why they are called {\it fossils}. We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Deep $r-$band images were taken for each candidate and optical spectroscopic observations were obtained for $\sim$ 1200 galaxies. This new dataset was completed with SDSS DR7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies ($\Delta m_{12}$) and the first and fourth ranked galaxies ($\Delta m_{14}$) within 0.5 $R_{{\rm 200}}$. We consider fossil systems those with $\Delta m_{12} \ge 2$ mag or $\Delta m_{14} \ge 2.5$ mag within the errors. We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but fossils are always extreme cases. In particular, they host the brightest central galaxies and the fraction of total galaxy light enclosed in the central galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed due to mergers of $L^\ast$ galaxies. The large magnitude gap is a consequence of the extreme merger ratio within fossil systems and therefore it is an evolutionary effect. Moreover, we suggest that at least one candidate in our sample could represent a transitional fossil stage.Comment: 14 pages, 11 figures, accepted for publication in A&

Collective vs local measurements in qubit mixed state estimation

We discuss the problem of estimating a general (mixed) qubit state. We give the optimal guess that can be inferred from any given set of measurements. For collective measurements and for a large number $N$ of copies, we show that the error in the estimation goes as 1/N. For local measurements we focus on the simpler case of states lying on the equatorial plane of the Bloch sphere. We show that standard tomographic techniques lead to an error proportional to $1/N^{1/4}$, while with our optimal data processing it is proportional to $1/N^{3/4}$.Comment: 4 pages, 1 figure, minor style changes, refs. adde

Chemical pressure effects on the spectroscopic properties of Nd3+-doped gallium nano-garnets

[EN] Nd3+-doped RE3Ga5O12 (RE = Gd, Y, and Lu) nano-crystalline garnets of 40-45 nm in size have been synthesized by a sol-gel method. With the decrease of the RE atom size, the chemical pressure related to the decreasing volumes of the GaO4 tetrahedral, GaO6 octahedral and REO8 dodecahedral units drive the nano-garnets toward a more compacted structure, which is evidenced by the change of the vibrational phonon mode frequencies. The chemical pressure also increases the crystal-field strength felt by the RE3+ ions while decreases the orthorhombic distortion of the REO8 local environment. These effects alter the absorption and emission properties of the Nd3+ ion measured in the near-infrared luminescence range from 0.87 to 1.43 ¿m associated with the 4 F3/2¿4 IJ (J = 9/2, 11/2, 13/2) transitions. The 4 F3/2 luminescence decay curves show non-exponential behavior due to dipole-dipole energy transfer interactions among Nd3+ ions that increases with pressure.Authors are grateful to The Governments of Spain and India for the Indo-Spanish Joint Programme of Bilateral Cooperation in Science and Technology (PRI-PIBIN-2011-1153/DST-INT-Spain-P-38-11). Dr. Venkatramu is grateful to DAE-BRNS, Government of India for the award of DAE Research Award for Young Scientist (No. 2010/20/34/5/BRNS/2223). This work have been partially supported by MINECO under The National Program of Materials (MAT2013-46649-C4-2-P/-3-P/-4-P), The Consolider-Ingenio 2010 Program (MALTA CSD2007-00045), by Fundacion CajaCanarias (ENER-01), and by the EU-FEDER funds. V. Monteseguro wishes to thank MICINN for the FPI grant (BES-2011-044596). Authors also thank Agencia Canaria de Investigacion, Innovacion y Sociedad de la Informacion for the funds given to Universidad de La Laguna, co-financed by The European Social Fund by a percentage of 85%.Monteseguro, V.; Rathaiah, M.; Linganna, K.; Lozano-Gorrin, AD.; Hernandez-Rodriguez, MA.; Martin, IR.; Babu, P.... (2015). Chemical pressure effects on the spectroscopic properties of Nd3+-doped gallium nano-garnets. Optical Materials Express. 5(8):1661-1673. https://doi.org/10.1364/OME.5.001661S1661167358Pollnau, M., Hardman, P. ., Clarkson, W. ., & Hanna, D. . (1998). Upconversion, lifetime quenching, and ground-state bleaching in Nd3+:LiYF4. Optics Communications, 147(1-3), 203-211. doi:10.1016/s0030-4018(97)00524-5Brandle, C. D., & Barns, R. L. (1974). Crystal stoichiometry of Czochralski grown rare-earth gallium garnets. Journal of Crystal Growth, 26(1), 169-170. doi:10.1016/0022-0248(74)90223-1Venkatramu, V., Giarola, M., Mariotto, G., Enzo, S., Polizzi, S., Jayasankar, C. K., … Speghini, A. (2010). Nanocrystalline lanthanide-doped Lu3Ga5O12garnets: interesting materials for light-emitting devices. Nanotechnology, 21(17), 175703. doi:10.1088/0957-4484/21/17/175703Speghini, A., Piccinelli, F., & Bettinelli, M. (2011). Synthesis, characterization and luminescence spectroscopy of oxide nanopowders activated with trivalent lanthanide ions: The garnet family. Optical Materials, 33(3), 247-257. doi:10.1016/j.optmat.2010.10.039Krsmanović, R., Morozov, V. A., Lebedev, O. I., Polizzi, S., Speghini, A., Bettinelli, M., & Tendeloo, G. V. (2007). Structural and luminescence investigation on gadolinium gallium garnet nanocrystalline powders prepared by solution combustion synthesis. Nanotechnology, 18(32), 325604. doi:10.1088/0957-4484/18/32/325604Naccache, R., Vetrone, F., Speghini, A., Bettinelli, M., & Capobianco, J. A. (2008). Cross-Relaxation and Upconversion Processes in Pr3+ Singly Doped and Pr3+/Yb3+ Codoped Nanocrystalline Gd3Ga5O12: The Sensitizer/Activator Relationship. The Journal of Physical Chemistry C, 112(20), 7750-7756. doi:10.1021/jp711494dAntic-Fidancev, E., Hölsä, J., Lastusaari, M., & Lupei, A. (2001). Dopant-host relationships in rare-earth oxides and garnets doped with trivalent rare-earth ions. Physical Review B, 64(19). doi:10.1103/physrevb.64.195108Rodríguez-Carvajal, J. (1993). Recent advances in magnetic structure determination by neutron powder diffraction. Physica B: Condensed Matter, 192(1-2), 55-69. doi:10.1016/0921-4526(93)90108-iMonteseguro, V., Rodríguez-Hernández, P., Ortiz, H. M., Venkatramu, V., Manjón, F. J., Jayasankar, C. K., … Muñoz, A. (2015). Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure. Physical Chemistry Chemical Physics, 17(14), 9454-9464. doi:10.1039/c4cp05903dRay, S., León-Luis, S. F., Manjón, F. J., Mollar, M. A., Gomis, Ó., Rodríguez-Mendoza, U. R., … Lavín, V. (2014). Broadband, site selective and time resolved photoluminescence spectroscopic studies of finely size-modulated Y2O3:Eu3+ phosphors synthesized by a complex based precursor solution method. Current Applied Physics, 14(1), 72-81. doi:10.1016/j.cap.2013.07.027Nekvasil, V. (1978). The Crystal Field for Nd3+ in Garnets. Physica Status Solidi (b), 87(1), 317-323. doi:10.1002/pssb.2220870137Rodríguez-Mendoza, U. R., León-Luis, S. F., Muñoz-Santiuste, J. E., Jaque, D., & Lavín, V. (2013). Nd3+-doped Ca3Ga2Ge3O12garnet: A new optical pressure sensor. Journal of Applied Physics, 113(21), 213517. doi:10.1063/1.4809217Kaminska, A., Buczko, R., Paszkowicz, W., Przybylińska, H., Werner-Malento, E., Suchocki, A., … Saxena, S. (2011). Merging of the4F3/2level states of Nd3+ions in the photoluminescence spectra of gadolinium-gallium garnets under high pressure. Physical Review B, 84(7). doi:10.1103/physrevb.84.075483Allik, T. H., Stewart, S. A., Sardar, D. K., Quarles, G. J., Powell, R. C., Morrison, C. A., … Pinto, A. A. (1988). Preparation, structure, and spectroscopic properties ofNd3+:{La1−xLux}3[Lu1−yGay]2Ga3O12crystals. Physical Review B, 37(16), 9129-9139. doi:10.1103/physrevb.37.9129Wu, K., Yao, B., Zhang, H., Yu, H., Wang, Z., Wang, J., & Jiang, M. (2010). Growth and properties of Nd:Lu3Ga5O12 laser crystal by floating-zone method. Journal of Crystal Growth, 312(24), 3631-3636. doi:10.1016/j.jcrysgro.2010.09.029Jia, Z., Arcangeli, A., Tao, X., Zhang, J., Dong, C., Jiang, M., … Tonelli, M. (2009). Efficient Nd3+→Yb3+ energy transfer in Nd3+,Yb3+:Gd3Ga5O12 multicenter garnet crystal. Journal of Applied Physics, 105(8), 083113. doi:10.1063/1.3115442Guillot-Noel, O., Bellamy, B., Viana, B., & Gourier, D. (1999). Correlation between rare-earth oscillator strengths and rare-earth–valence-band interactions in neodymium-dopedYMO4(M=V,P, As),Y3Al5O12,andLiYF4matrices. Physical Review B, 60(3), 1668-1677. doi:10.1103/physrevb.60.1668Demidovich, A. A., Shkadarevich, A. P., Danailov, M. B., Apai, P., Gasmi, T., Gribkovskii, V. P., … Batay, L. E. (1998). Comparison of cw laser performance of Nd:KGW, Nd:YAG, Nd:BEL, and Nd:YVO 4 under laser diode pumping. Applied Physics B: Lasers and Optics, 67(1), 11-15. doi:10.1007/s003400050467Inokuti, M., & Hirayama, F. (1965). Influence of Energy Transfer by the Exchange Mechanism on Donor Luminescence. The Journal of Chemical Physics, 43(6), 1978-1989. doi:10.1063/1.1697063Lupei, V., & Lupei, A. (2000). Emission dynamics of the4F3/2level ofNd3+in YAG at low pump intensities. Physical Review B, 61(12), 8087-8098. doi:10.1103/physrevb.61.8087Maeda, K., Wada, N., Umino, M., Abe, M., Takada, Y., Nakano, N., & Kuroda, H. (1984). Concentration Dependence of Fluorescence Lifetime of Nd3+-Doped Gd3Ga5O12Lasers. Japanese Journal of Applied Physics, 23(Part 2, No. 10), L759-L760. doi:10.1143/jjap.23.l759Geusic, J. E., Marcos, H. M., & Van Uitert, L. G. (1964). LASER OSCILLATIONS IN Nd‐DOPED YTTRIUM ALUMINUM, YTTRIUM GALLIUM AND GADOLINIUM GARNETS. Applied Physics Letters, 4(10), 182-184. doi:10.1063/1.1753928Löhring, J., Nicklaus, K., Kujath, N., & Hoffmann, D. (2007). Diode pumped Nd:YGG laser for direct generation of pulsed 935 nm radiation for water vapour measurements. Solid State Lasers XVI: Technology and Devices. doi:10.1117/12.708220Maunier, C., Doualan, J. L., Moncorgé, R., Speghini, A., Bettinelli, M., & Cavalli, E. (2002). Growth, spectroscopic characterization, and laser performance of Nd:LuVO_4, a new infrared laser material that is suitable for diode pumping. Journal of the Optical Society of America B, 19(8), 1794. doi:10.1364/josab.19.00179

Pressure-Driven Symmetry-Preserving Phase Transitions in Co(IO3)(2)

[EN] High-pressure synchrotron X-ray diffraction studies of cobalt iodate, Co(IO3)(2), reveal a counterintuitive pressure-induced expansion along certain crystallographic directions. High-pressure Raman and infrared spectroscopy, combined with density-functional theory calculations, reveal that with increasing pressure, it becomes energetically favorable for certain I-O bonds to increase in length over the full range of pressure studied up to 28 GPa. This phenomenon is driven by the high-pressure behavior of iodate ion lone electron pairs. Two pressure-induced isosymmetric monoclinic-monoclinic phase transitions are observed at around 3.0 and 9.0 GPa, which are characterized by increasing oxygen coordination of the iodine atoms and the probable formation of pressure-induced metavalent bonds. Pressure-volume equations of state are presented, as well as a detailed discussion of the pressure dependences of the observed Raman- and infrared-active modes, which clarifies previous inconsistencies in the literature.This work was supported by the Generalitat Valenciana under Project PROMETEO 2018/123-EFIMAT and by the Spanish Ministerio de Ciencia, Universidades, e Investigacion under Projects PID2019-106383GB-41/42/43, as well as through MALTA Consolider Team research network (RED2018102612-T). A.M. and P.R.-H. acknowledge computing time provided by Red Espan~ola de Supercomputacion (RES) and the MALTA Consolider Team cluster. D.E. acknowledges the resources and technical assistance provided by the Informatics Service of Universitat de Valencia through the Tirant III cluster. A.L. and D.E. would like to thank the Generalitat Valenciana for the Ph.D. Fellowship no. GRISOLIAP/2019/025. R.T. acknowledges funding from the Spanish Ministerio de Economia y Competitividad (MINECO) via the Juan de la Cierva Formacion fellowship (FJC2018-036185-I). C.P. is thankful for the financial support of the Spanish Mineco Project no. FIS2017-83295-P. E.B would like to thank the University of Valencia for his "Attraccio de Talent" postdoctoral contract (UV-INV_POSTDOC19-1026935). The authors thank Sandrine Beauquis from Symme, Universite Savoie Mont Blanc (France), for her technical assistance concerning the SEM and ADX analyses. PXRD experiments were performed at the MSPD beamline of ALBA Synchrotron (experiment no. 2019083663). IR experiments were performed at the MIRAS beamline of ALBA Synchrotron (experiment no. 2020024118).Liang, A.; Popescu, C.; Manjón, F.; Turnbull, R.; Bandiello, E.; Rodriguez-Hernandez, P.; Muñoz, A.... (2021). Pressure-Driven Symmetry-Preserving Phase Transitions in Co(IO3)(2). The Journal of Physical Chemistry C. 125(31):17448-17461. https://doi.org/10.1021/acs.jpcc.1c0465917448174611253

NiO diluted in high surface area TiO2 as efficient catalysts for the oxidative dehydrogenation of ethane

[EN] Catalysts consisting of NiO diluted in high surface area TiO2 can be as efficient in the oxidative dehydrogenation of ethane as the most selective NiO-promoted catalysts reported previously in the literature. By selecting the titania matrix and the NiO loading, yields to ethylene over 40% have been obtained. In the present article, three different titanium oxides (TiO2) have been employed as supports or diluters of nickel oxide and have been tested in the oxidative dehydrogenation of ethane to ethylene. All TiO2 used present anatase as the main crystalline phase and different surface areas of 11,55 and 85 m(2) g(-1). It has been observed that by selecting an appropriate nickel loading and the titanium oxide extremely high selectivity towards ethylene can be obtained. Thus, nickel oxide supported on TiO2 with high surface areas (i.e. 55 and 85 m(2) g(-1)) have resulted to give the best catalytic performance although the optimal nickel loading is different for each case. The optimal catalyst has been obtained for NiO-loadings up to 5-10 theoretical monolayers regardless of the TiO2 employed. Free TiO2 is inactive whereas unsupported NiO is active and unselective (forming mainly carbon dioxide) and, therefore, unmodified NiO particles have to be avoided in order to obtain the optimal catalytic performance. The use of low surface area titania (11 m(2) g(-1)) have led to the lowest selectivity to olefin due to the presence of an excess of free NiO particles. (C) 2017 Elsevier B.V. All rights reserved.The authors would like to acknowledge the DGICYT in Spain CTQ2012-37925-C03-2, CTQ2015-68951-C3-1-R, CTQ2015-68951-C3-3-R and SEV-2012-0267 Projects for financial support. D.D. also thanks Severo Ochoa Excellence fellowship (SVP-2014-068669). We also thank the University of Valencia (UV-INV-AE-16-484416 project) and SCSIE-UV for assistanceSanchis, R.; Delgado-Muñoz, D.; Agouram, S.; Soriano Rodríguez, MD.; Vázquez, MI.; Rodriguez-Castellon, E.; Solsona, B.... (2017). NiO diluted in high surface area TiO2 as efficient catalysts for the oxidative dehydrogenation of ethane. Applied Catalysis A General. 536:18-26. https://doi.org/10.1016/j.apcata.2017.02.012S182653

Disability and perceived stress in primary care patients with major depression

Background: Major depressive disorder (MDD) is highly prevalent in the Spanish primary care (PC) setting and the leading cause of disability in Spain. The aim of this study was to evaluate several key psychometric properties of the Sheehan Disability Scale (SDS) in patients with or without MDD and varying degrees of symptom severity using the Patient Health Questionnaire-9 (PHQ-9). Method: A total of 1, 704 PC patients participating in the PsicAP clinical trial completed the SDS and PHQ-9. We evaluated the factor structure, measurement invariance across gender, internal consistency, and the discriminative and predictive validity. Results: Confirmatory factor analyses revealed a unifactorial model of the SDS containing 4 items (SDS-4) with the best model fit (CFI: .99; GFI: .99; TLI: 96; RMSEA: .10). This model contained the three life domain items (work, family, and social life) plus perceived stress (PS) with significant loadings. The internal consistency of the SDS-4 was acceptable in patients with or without MDD, regardless of symptom severity. The SDS-4 also showed good discriminative capacity and acceptable predictive validity in all subsamples. Conclusions: These findings support the use of the SDS-4 to assess depression-related disability in patients at Spanish primary care centres