Approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon with inner voids

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a starting point for our a-Si:H models with voids that were made by removing a cluster of silicon atoms out of the bulk and terminating the resulting dangling bonds with hydrogens. Our calculation shows that the presence of voids leads to localized low energy (30-50 cm^{-1}) states in the vibrational spectrum of the system. The nature and localization properties of these states are analyzed by various visualization techniques.Comment: 15 pages with 6 PS figures, to appear in PRB in December 199

Ratings of age of acquisition of 299 words across 25 languages: Is there a cross-linguistic order of words?

We present a new set of subjective age-of-acquisition (AoA) ratings for 299 words (158 nouns, 141 verbs) in 25 languages from five language families (Afro-Asiatic: Semitic languages; Altaic: one Turkic language: Indo-European: Baltic, Celtic, Germanic, Hellenic, Slavic, and Romance languages; Niger-Congo: one Bantu language; Uralic: Finnic and Ugric languages). Adult native speakers reported the age at which they had learned each word. We present a comparison of the AoA ratings across all languages by contrasting them in pairs. This comparison shows a consistency in the orders of ratings across the 25 languages. The data were then analyzed (1) to ascertain how the demographic characteristics of the participants influenced AoA estimations and (2) to assess differences caused by the exact form of the target question (when did you learn vs. when do children learn this word); (3) to compare the ratings obtained in our study to those of previous studies; and (4) to assess the validity of our study by comparison with quasi-objective AoA norms derived from the MacArthur–Bates Communicative Development Inventories (MB-CDI). All 299 words were judged as being acquired early (mostly before the age of 6 years). AoA ratings were associated with the raters’ social or language status, but not with the raters’ age or education. Parents reported words as being learned earlier, and bilinguals reported learning them later. Estimations of the age at which children learn the words revealed significantly lower ratings of AoA. Finally, comparisons with previous AoA and MB-CDI norms support the validity of the present estimations. Our AoA ratings are available for research or other purposes

Noun and verb knowledge in monolingual preschool children across 17 languages: Data from cross-linguistic lexical tasks (LITMUS-CLT)

This article investigates the cross-linguistic comparability of the newly developed lexical assessment tool Cross-linguistic Lexical Tasks (LITMUS-CLT). LITMUS-CLT is a part the Language Impairment Testing in Multilingual Settings (LITMUS) battery (Armon-Lotem, de Jong & Meir, 2015). Here we analyse results on receptive and expressive word knowledge tasks for nouns and verbs across 17 languages from eight different language families: Baltic (Lithuanian), Bantu (isiXhosa), Finnic (Finnish), Germanic (Afrikaans, British English, South African English, German, Luxembourgish, Norwegian, Swedish), Romance (Catalan, Italian), Semitic (Hebrew), Slavic (Polish, Serbian, Slovak) and Turkic (Turkish). The participants were 639 monolingual children aged 3;0-6;11 living in 15 different countries. Differences in vocabulary size were small between 16 of the languages; but isiXhosa-speaking children knew significantly fewer words than speakers of the other languages. There was a robust effect of word class: accuracy was higher for nouns than verbs. Furthermore, comprehension was more advanced than production. Results are discussed in the context of cross-linguistic comparisons of lexical development in monolingual and bilingual populations

EQ-5D in Central and Eastern Europe : 2000-2015

Objective: Cost per quality-adjusted life year data are required for reimbursement decisions in many Central and Eastern European (CEE) countries. EQ-5D is by far the most commonly used instrument to generate utility values in CEE. This study aims to systematically review the literature on EQ-5D from eight CEE countries. Methods: An electronic database search was performed up to July 1, 2015 to identify original EQ-5D studies from the countries of interest. We analysed the use of EQ-5D with respect to clinical areas, methodological rigor, population norms and value sets. Results: We identified 143 studies providing 152 country-specific results with a total sample size of 81,619: Austria (n=11), Bulgaria (n=6), Czech Republic (n=18), Hungary (n=47), Poland (n=51), Romania (n=2), Slovakia (n=3) and Slovenia (n=14). Cardiovascular (20%), neurologic (16%), musculoskeletal (15%) and endocrine/nutritional/metabolic diseases (14%) were the most frequently studied clinical areas. Overall 112 (78%) of the studies reported EQ VAS results and 86 (60%) EQ-5D index scores, of which 27 (31%) did not specify the applied tariff. Hungary, Poland and Slovenia have population norms. Poland and Slovenia also have a national value set. Conclusions: Increasing use of EQ-5D is observed throughout CEE. The spread of health technology assessment activities in countries seems to be reflected in the number of EQ-5D studies. However, improvement in informed use and methodological quality of reporting is needed. In jurisdictions where no national value set is available, in order to ensure comparability we recommend to apply the most frequently used UK tariff. Regional collaboration between CEE countries should be strengthened

Giant cell cyst of the skull : à case report

Les tumeurs à cellules géantes de l'os sont des lésions rares qui touchent principalement les épiphyses des os longs. Ils représentent 3 à 7% des tumeurs osseuses primitives. Ces tumeurs sont exceptionnelles dans le crâne et touchent principalement le sphénoïde et les os temporaux. Ces lésions sont généralement bénignes, localement agressives et nécessitent une ablation complète. Nous rapportons un cas de kyste à cellules géantes du crâne impliquant la voûte crânienne dans notre environnement. Une femme de 20 ans s'est présentée avec une masse occipito-cervicale droite, localisée, non sensible et fixée. Elle s'est présentée avec un syndrome cérébelleux. Une tomodensitométrie (TDM) a montré une lésion extraaxiale lytique impliquant l'os occipital droit et s'étendant dans la fosse postérieure. La patiente a subi une craniectomie occipitale droite avec résection de l'os et de la masse épidurale suivie d'une reconstruction osseuse artificielle (ciment de méthacrylate de méthyle). L'analyse histopathologique a révélé une tumeur à cellules géantes. L'évolution postopératoire s'est déroulée sans incident.Aucune récidive locale n'a été observée après un suivi de 3 ans. Les tumeurs à cellules géantes sont généralement des lésions bénignes localement agressives avec un taux élevé de récidive locale. L'excision chirurgicale totale est le traitement de choix. Ce rapport contribue à la littérature sur la tumeur à cellules géantes du crâne, en particulier la fosse postérieure et la méthode d'intervention chirurgicale utilisée pour le traitement. La place de la thérapie adjudante reste controversée.Mots clés : tumeur à cellule géante, crâne, os occipitale, chirurgie.Giant cell tumors of the bone are rare lesions that primarily affect the epiphyses of long bones. They represent 3 to 7% of primitive bone tumors. These tumors are exceptional in the skull and affect mainly the sphenoid and the temporal bones. These lesions are usually benign as well aslocally agressive and require complete removal. We report a case of giant cell cyst of the skull involving the cranial vault in a 20-year-old woman presented with localized, non tender, fixed right occipito-cervical mass. Her physical exam revealed a cerebellar syndrom. A computed tomography (CT) scan showed a lytic extensive extraaxial lesion involving the right occipital bone and expanding into the posterior fossa. The patient underwent a right occipital craniectomy with resection of the bone and the epidural mass followed by an artificial bone reconstruction (methyl methacrylate cement). Histopathologic analysis revealed a giant cell tumor. Post-operative course was uneventful. No local recurrence was observed after 3 years follow-up. Giant cell tumors are generally benign, locally aggressive lesions with a high rate of local recurrence. Total surgical excision is the treatment of choice. This report contributes to the litterature of giant cell tumor of the skull, especially the posterior fossa and the method of surgical intervention used fortreatment. The place of the adjuvent therapy remains controversial.Keywords : Giant cell tumor, skull, occipital bone, surger