Antiferrodistortive phase transition in EuTiO3

X-ray diffraction, dynamical mechanical analysis and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300K the perovskite structure changes from cubic Pm-3m to tetragonal I4/mcm due to antiphase tilting of oxygen octahedra along the c axis (a0a0c- in Glazer notation). The phase transition is analogous to SrTiO3. However, some ceramics as well as single crystals of EuTiO3 show different infrared reflectivity spectra bringing evidence of a different crystal structure. In such samples electron diffraction revealed an incommensurate tetragonal structure with modulation wavevector q ~ 0.38 a*. Extra phonons in samples with modulated structure are activated in the IR spectra due to folding of the Brillouin zone. We propose that defects like Eu3+ and oxygen vacancies strongly influence the temperature of the phase transition to antiferrodistortive phase as well as the tendency to incommensurate modulation in EuTiO3.Comment: PRB, in pres

Magnetodielectric effect and optic soft mode behaviour in quantum paraelectric EuTiO3 ceramics

Infrared reflectivity and time-domain terahertz transmission spectra of EuTiO3 ceramics revealed a polar optic phonon at 6 - 300K, whose softening is fully responsible for the recently observed quantum paraelectric behaviour. Even if our EuTiO3 ceramics show lower permittivity than the single crystal due to a reduced density and/or small amount of secondary pyrochlore Eu2Ti2O7 phase, we confirmed the magnetic field dependence of the permittivity, also slightly smaller than in single crystal. Attempt to reveal the soft phonon dependence at 1.8K on the magnetic field up to 13T remained below the accuracy of our infrared reflectivity experiment

Multimodal Interactive Parsing

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-38628-2_57Probabilistic parsing is a fundamental problem in Computational Linguistics, whose goal is obtaining a syntactic structure associated to a sentence according to a probabilistic grammatical model. Recently, an interactive framework for probabilistic parsing has been introduced, in which the user and the system cooperate to generate error-free parse trees. In an early prototype developed according to this interactive parsing technology, user feedback was provided by means of mouse actions and keyboard strokes. Here we augment the interaction style with support for (non-deterministic) natural handwritten recognition, and provide confidence measures as a visual aid to ease the correction process. Handwriting input seems to be a modality specially suitable for parsing, since the vocabulary size involved in the recognition of syntactic labels is fairly limited and thus intuitively errors should be small. However, errors may increase as handwriting quality (i.e., calligraphy) degrades. To solve this problem, we introduce a late fusion approach that leverages both on-line and off-line information, corresponding to pen strokes and contextual information from the parse trees. We demonstrate that late fusion can effectively help to disambiguate user intention and improve system accuracy.This research has received funding from the EC’s 7th Framework Programme (FP7/2007-13) under grant agreement No.287576- CasMaCat; from the Spanish MEC under the STraDA project (TIN2012-37475- C02-01) and the MITTRAL project (TIN2009-14633-C03-01); from the GV under the Prometeo project; and from the Universidad del Cauca (Colombia)Benedí Ruiz, JM.; Sánchez Peiró, JA.; Leiva, LA.; Sánchez Sáez, R.; Maca, M. (2013). Multimodal Interactive Parsing. En Pattern Recognition and Image Analysis. Springer. 484-491. https://doi.org/10.1007/978-3-642-38628-2_57S484491Afonso, S., Bick, E., Haber, R., Santos, D.: Floresta sintá(c)tica: a treebank for portuguese. In: Proc. LREC, pp. 1698–1703 (2002)Brants, T., Plaehn, O.: Interactive corpus annotation. In: Proc. LREC (2000)Guyon, I., Schomaker, L., Plamondon, R., Liberman, M., Janet, S.: UNIPEN project of on-line data exchange and recognizer benchmarks. In: Proc. ICPR, pp. 29–33 (1994)Lease, M., Charniak, E., Johnson, M., McClosky, D.: A look at parsing and its applications. In: Proc. AAAI, pp. 1642–1645 (2006)Marcus, M.P., Santorini, B., Marcinkiewicz, M.A.: Building a large annotated corpus of English: the Penn Treebank. Computational Linguistics 19(2), 313–330 (1993)Ortiz, D., Leiva, L.A., Alabau, V., Casacuberta, F.: Interactive machine translation using a web-based architecture. In: Proc. IUI, pp. 423–425 (2010)Romero, V., Leiva, L.A., Toselli, A.H., Vidal, E.: Interactive multimodal transcription of text images using a web-based demo system. In: Proc. IUI, pp. 477–478 (2009)Sánchez-Sáez, R., Leiva, L.A., Sánchez, J.A., Benedí, J.M.: Interactive predictive parsing using a web-based architecture. In: Proc. NAACL-HLT, pp. 37–40 (2010)Sánchez-Sáez, R., Sánchez, J.A., Benedí, J.M.: Interactive predictive parsing. In: Proc. IWPT, pp. 222–225 (2009)Sánchez-Sáez, R., Sánchez, J.A., Benedí, J.M.: Confidence measures for error discrimination in an interactive predictive parsing framework. In: Proc. COLING, pp. 1220–1228 (2010

Multiple ethnic origins of mitochondrial DNA lineages for the population of Mauritius

This article reports on the first genetic assessment of the contemporary Mauritian population. Small island nodes such as Mauritius played a critical role in historic globalization processes and revealing high-resolution details of labour sourcing is crucial in order to better understand early-modern diaspora events. Mauritius is a particularly interesting case given detailed historic accounts attesting to European (Dutch, French and British), African and Asian points of origin. Ninety-seven samples were analysed for mitochondrial DNA to begin unravelling the complex dynamics of the island’s modern population. In corroboration with general demographic information, the majority of maternal lineages were derived from South Asia (58.76%), with Malagasy (16.60%), East/Southeast Asian (11.34%) and Sub-Saharan African (10.21%) also making significant contributions. This study pinpoints specific regional origins for the South Asian genetic contribution, showing a greater influence on the contemporary population from northern and southeast India. Moreover, the analysis of lineages related to the slave trade demonstrated that Madagascar and East Asia were the main centres of origin, with less influence from West Africa

Distress, depression and coping in HLA-B27-associated anterior uveitis with focus on gender differences

Background/aims To evaluate depression, coping with disease and stress, and the subjective impression of distress and/or life events as triggers for recurrences in HLA-B27-associated anterior uveitis (B27-AU), with attention to gender-specific characteristics. Methods 171 patients with a history of B27-AU responded to a postal survey performed between January 2006 and April 2008 using standardised psychological questionnaires: Beck Depression Inventory, Freiburg Questionnaire on Coping with Illness, and Stress Coping Inventory. Results Patients with B27-AU differed from healthy controls showing more depressive symptoms (Beck Depression Inventory, 31.6%), applying characteristic disease coping as well as negative stress coping strategies. Female B27-AU patients tended to react with depression and male patients to use negative stress coping strategies. 57.9% of patients believed that psychological distress was a trigger for relapses, and 34.5% stated specific life events. Together, this group of patients achieved higher depression scores and used more negative disease and stress coping styles than patients without perception of distress. Conclusion Patients with B27-AU patients exhibited significant psychopathology concerning depression and disease coping. Distress and life events were subjectively suspected to be a trigger. By imparting knowledge to the patients on probable development of depressive moods and the role of stress/life events as trigger for relapses, as well as offering behaviour therapy to optimise coping, may help patients to cope better with B27-AU

Mn-doped Ga(As,P) and (Al,Ga)As ferromagnetic semiconductors: Electronic structure calculations

Journals published by the American Physical Society can be found at http://journals.aps.org/A remarkable progress towards functional ferromagnetic semiconductor materials for spintronics has been achieved in p-type (Ga,Mn)As. Robust hole-mediated ferromagnetism has, however, been observed also in other III-V hosts such as antimonides, GaP, or (Al,Ga)As, which opens a wide area of possibilities for optimizing the host composition towards higher ferromagnetic Curie temperatures. Here we explore theoretically hole-mediated ferromagnetism and Mn incorporation in Ga(As,P) and (Al,Ga)As ternary hosts. While alloying (Ga,Mn)As with Al has only a small effect on the Curie temperature we predict a sizable enhancement of Curie temperatures in the smaller lattice constant Ga(As,P) hosts. Mn-doped Ga(As,P) is also favorable, as compared to (Al,Ga)As, with respect to the formation of carrier and moment compensating interstitial Mn impurities. In (Ga,Mn) (As,P) we find a marked decrease of the partial concentration of these detrimental impurities with increasing P content

Dependence of Curie Temperature on the Thickness of Epitaxial (Ga,Mn)As Film

We present the magnetotransport properties of very thin (5 to 15 nm) single (Ga,Mn)As layers grown by low temperature molecular beam epitaxy. A lower (Ga,Mn)As thickness limit of 5 nm for the ferromagnetic phase and the dependence of the Curie temperature on (Ga,Mn)As thickness are determined from electrical transport measurements. The Curie temperature is determined to be 97 K for the thinnest ferromagnetic sample and is found to decrease for increasing layer thickness. A carrier density of ~7.1$\times10^{20}$ cm$^{-3}$ for the 5 nm thick (Ga,Mn)As layer is determined from Hall measurements. Differences between magnetotransport properties of thick and thin (Ga,Mn)As layers are observed and discussed.Comment: 6 pages, 4 figure