Recalcitrant bubbles

We demonstrate that thermocapillary forces may drive bubbles against liquid flow in ‘anomalous' mixtures. Unlike ‘ordinary' liquids, in which bubbles migrate towards higher temperatures, we have observed vapour bubbles migrating towards lower temperatures, therefore against the flow. This unusual behaviour may be explained by the temperature dependence of surface tension of these binary mixtures. Bubbles migrating towards their equilibrium position follow an exponential trend. They finally settle in a stationary position just ‘downstream' of the minimum in surface tension. The exponential trend for bubbles in ‘anomalous' mixtures and the linear trend in pure liquids can be explained by a simple model. For larger bubbles, oscillations were observed. These oscillations can be reasonably explained by including an inertial term in the equation of motion (neglected for smaller bubbles)

Assessment tool for visual perception deficits in cerebral visual impairment: reliability and validity

Aim: To evaluate the reliability and validity of the Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6). Method: Reliability was assessed via test–retest correlation and intraclass correlation coefficient (ICC) in typically developing children, children with cerebral visual impairment (CVI), intellectual impairment, and simulated impaired vision (validation groups n=59, mean developmental age=4y 10mo, 27 females, 32 males). Internal validity was evaluated with a confirmatory factor analysis on the normative sample (n=301, median age=4y 8mo, SD=9.7mo, 148 females, 153 males). External validity was assessed by correlating performance on CVIT 3–6 with L94, the Beery‐Buktenica Developmental Test of Visuo‐Motor Integration (Beery‐VMI), the Freiburg Vision Test, the revised Snijders‐Oomen Nonverbal Intelligence Test for children between 2 years 6 months and 7‐years‐old (SON‐R 2.5–7), and the Social Responsiveness Scale (SRS) questionnaire and by comparing performance between validation groups. Results: We observed very good test–retest reliability (r=0.82, p Interpretation: CVIT 3–6 is grounded in knowledge of visual perception. The tool specifically measures CVI‐related visual perception deficits and is not mediated by intellectual abilities or low visual acuity. What the Paper Adds: - Evidence for good test–retest reliability of the Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6). - Factor structure of normative data reflects CVIT 3–6's foundations in vision science. - CVIT 3–6 specifically measures visual perception impairments. - CVIT 3–6 performance is not influenced by intelligence or low visual acuity.</p

Assessment tool for visual perception deficits in cerebral visual impairment: Reliability and validity

Aim: To evaluate the reliability and validity of the Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6). Method: Reliability was assessed via test–retest correlation and intraclass correlation coefficient (ICC) in typically developing children, children with cerebral visual impairment (CVI), intellectual impairment, and simulated impaired vision (validation groups n=59, mean developmental age=4y 10mo, 27 females, 32 males). Internal validity was evaluated with a confirmatory factor analysis on the normative sample (n=301, median age=4y 8mo, SD=9.7mo, 148 females, 153 males). External validity was assessed by correlating performance on CVIT 3–6 with L94, the Beery‐Buktenica Developmental Test of Visuo‐Motor Integration (Beery‐VMI), the Freiburg Vision Test, the revised Snijders‐Oomen Nonverbal Intelligence Test for children between 2 years 6 months and 7‐years‐old (SON‐R 2.5–7), and the Social Responsiveness Scale (SRS) questionnaire and by comparing performance between validation groups. Results: We observed very good test–retest reliability (r=0.82, p&lt;0.001, ICC=0.80) and confirmed the hypothesized factor structure (comparative fit index=1; Tucker‐Lewis index=1.045). We found high correlations with tests with a strong visual perception component (L94: r=0.74, p&lt;0.001; SON‐R 2.5–7: r=0.37, p=0.01) and low correlations with other tests (Beery‐VMI: r=0.25, p=0.09; SRS: r=0–0.26, p=0.09). Lowest scores were observed for children with CVI compared to the other validation groups (F[3,44]=5.1, p=0.003). Interpretation: CVIT 3–6 is grounded in knowledge of visual perception. The tool specifically measures CVI‐related visual perception deficits and is not mediated by intellectual abilities or low visual acuity. What the Paper Adds: - Evidence for good test–retest reliability of the Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6). - Factor structure of normative data reflects CVIT 3–6's foundations in vision science. - CVIT 3–6 specifically measures visual perception impairments. - CVIT 3–6 performance is not influenced by intelligence or low visual acuity.</p

Assessment tool for visual perception deficits in cerebral visual impairment: development and normative data of typically developing children

Aim: To develop an assessment tool that measures a wide range of visual perceptual deficits common in cerebral visual impairment (CVI) and to provide normative data from typically developing children between 3 and 6 years of age. Method: Test development reflected cross‐talk between vision research and clinical relevance for CVI. The Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6) includes 14 subtests covering four domains of visual perception: Object Recognition, Degraded Object Recognition, Motion Perception, and Global–Local Processing. Normative data were collected from 301 typically developing children (mean age 4y 8mo [SD 9.7mo]; 148 females, 153 males). A questionnaire was administered to parents about pregnancy duration, birth, and developmental problems. Results: Average total CVIT 3–6 performance was 60.1 (SD 5.5) out of 70. The cut‐off score for normal visual perception (53) was set at the 10th centile of scores in typically developing children. Multiple regression indicated CVIT 3–6 visual perception scores increase with age for children born at 36 weeks’ gestational age or later (β=−18.03, 95% confidence interval −31.31 to −4.75). Interpretation: CVIT 3–6 is a tool to assess a wide range of visual perceptual deficits common in CVI. Age‐dependent normative data are available because we found performance increased with age. What the Paper Adds: - A test for visual perceptual deficits common in cerebral visual impairment. - Visual perceptual functions improve with age in full‐term typically developing children.</p

Assessment tool for visual perception deficits in cerebral visual impairment: development and normative data of typically developing children

Aim: To develop an assessment tool that measures a wide range of visual perceptual deficits common in cerebral visual impairment (CVI) and to provide normative data from typically developing children between 3 and 6 years of age. Method: Test development reflected cross‐talk between vision research and clinical relevance for CVI. The Children's Visual Impairment Test for 3‐ to 6‐year‐olds (CVIT 3–6) includes 14 subtests covering four domains of visual perception: Object Recognition, Degraded Object Recognition, Motion Perception, and Global–Local Processing. Normative data were collected from 301 typically developing children (mean age 4y 8mo [SD 9.7mo]; 148 females, 153 males). A questionnaire was administered to parents about pregnancy duration, birth, and developmental problems. Results: Average total CVIT 3–6 performance was 60.1 (SD 5.5) out of 70. The cut‐off score for normal visual perception (53) was set at the 10th centile of scores in typically developing children. Multiple regression indicated CVIT 3–6 visual perception scores increase with age for children born at 36 weeks’ gestational age or later (β=−18.03, 95% confidence interval −31.31 to −4.75). Interpretation: CVIT 3–6 is a tool to assess a wide range of visual perceptual deficits common in CVI. Age‐dependent normative data are available because we found performance increased with age. What the Paper Adds: - A test for visual perceptual deficits common in cerebral visual impairment. - Visual perceptual functions improve with age in full‐term typically developing children.</p

Corpora and historical linguistics Corpora e linguística histórica

The present article aims to survey and assess the current state of electronic historical corpora and corpus methodology, and attempts to look into possible future developments. It highlights the fact that within the wide spectrum of corpus linguistic methodology, historical corpus linguistics has emerged as a vibrant field that has significantly added to the appeal felt for the study of language history and change. In fact, according to a historical linguist with more than fifty years of experience, "[w]e could even go as far as to say that without the support and new impetus provided by corpora, evidence-based historical linguistics would have been close to the end of its life-span in these days of rapid-changing life and research, increasing competition on the academic career track and the methodological attractions offered to young scholars" (RISSANEN, forthcoming). Historical corpora and other electronic resources have also made the study of language history attractive: working on them engages students in an individual and interactive way that they find appealing (CURZAN 2000, p. 81).<br>Este artigo objetiva fazer um levantamento e avaliar o estado da arte dos corpora históricos eletrônicos e da metodologia de estudos de corpora, assim como sugerir possíveis desenvolvimentos futuros na área. Destaca-se que dentro do espectro metodológico da linguística de corpus, a linguística de corpus histórica emergiu como um campo de investigação vibrante que tem adicionado interesse ao estudo da história e da mudança linguística. De acordo com um pesquisador da área com mais de cinqüenta anos de experiência, "pode-se dizer que sem o apoio e o novo ímpeto trazidos pelos corpora, a linguística histórica baseada em evidências teria estado próxima ao fim de sua vida nesses tempos de rápidas mudanças de vida e de pesquisa, aumentando a competição na carreira acadêmica e nas atrações metodológicas oferecidas aos jovens pesquisadores (RISSANEN, no prelo). Corpora históricos e outros recursos eletrônicos têm também tornado o estudo da história da língua atraente: eles engajam a atenção dos estudantes tanto de forma individual quanto interativa (CURZAN 2000, p. 81)