31,511 research outputs found

    Celebration Schedule 2015 (Friday)

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    Full presentation schedule for Celebration, Friday, May 1, 201

    Grammatical Morphology in School-Age Children With and Without Language Impairment: A Discriminant Function Analysis

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    Purpose: The purpose of this study was to test Bedore and Leonard\u27s (1998) proposal that a verb morpheme composite may hold promise as a clinical marker for specific language impairment (SLI) in English speakers and serve as an accurate basis for the classification of children with and without SLI beyond the preschool level. Method: The language transcripts of 50 school-age children with SLI (Mage = 7;9 [years;months]) and 50 age-matched typically developing peers (Mage = 7;9) were analyzed. Following the Bedore and Leonard (1998) procedure, 3 variables were measured: a finite verb morpheme composite, a noun morpheme composite, and mean length of utterance in morphemes (MLUm). Results: Overall findings indicated that neither grammatical morpheme composite alone adequately discriminated the groups at this developmental level. However, combining the verb and noun grammatical morpheme composite measures with MLUm resulted in good discriminant accuracy in classifying subgroups of the youngest children with and without SLI in the school-age sample. Conclusion: Verb morphology alone is not a useful clinical marker of SLI in school-age children. Potential explanations for these findings and ideas for future research are discussed

    Factors affecting consistency and accuracy in identifying modern macroperforate planktonic foraminifera

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    Planktonic foraminifera are widely used in biostratigraphic, palaeoceanographic and evolutionary studies, but the strength of many study conclusions could be weakened if taxonomic identifications are not reproducible by different workers. In this study, to assess the relative importance of a range of possible reasons for among-worker disagreement in identification, 100 specimens of 26 species of macroperforate planktonic foraminifera were selected from a core-top site in the subtropical Pacific Ocean. Twenty-three scientists at different career stages – including some with only a few days experience of planktonic foraminifera – were asked to identify each specimen to species level, and to indicate their confidence in each identification. The participants were provided with a species list and had access to additional reference materials. We use generalised linear mixed-effects models to test the relevance of three sets of factors in identification accuracy: participant-level characteristics (including experience), species-level characteristics (including a participant’s knowledge of the species) and specimen-level characteristics (size, confidence in identification). The 19 less experienced scientists achieve a median accuracy of 57 %, which rises to 75 % for specimens they are confident in. For the 4 most experienced participants, overall accuracy is 79 %, rising to 93 % when they are confident. To obtain maximum comparability and ease of analysis, everyone used a standard microscope with only 35× magnification, and each specimen was studied in isolation. Consequently, these data provide a lower limit for an estimate of consistency. Importantly, participants could largely predict whether their identifications were correct or incorrect: their own assessments of specimen-level confidence and of their previous knowledge of species concepts were the strongest predictors of accuracy

    Grammatical Morphology in School-Age Children With and Without Language Impairment: A Discriminant Function Analysis

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    Purpose: The purpose of this study was to test Bedore and Leonard\u27s (1998) proposal that a verb morpheme composite may hold promise as a clinical marker for specific language impairment (SLI) in English speakers and serve as an accurate basis for the classification of children with and without SLI beyond the preschool level. Method: The language transcripts of 50 school-age children with SLI (Mage = 7;9 [years;months]) and 50 age-matched typically developing peers (Mage = 7;9) were analyzed. Following the Bedore and Leonard (1998) procedure, 3 variables were measured: a finite verb morpheme composite, a noun morpheme composite, and mean length of utterance in morphemes (MLUm). Results: Overall findings indicated that neither grammatical morpheme composite alone adequately discriminated the groups at this developmental level. However, combining the verb and noun grammatical morpheme composite measures with MLUm resulted in good discriminant accuracy in classifying subgroups of the youngest children with and without SLI in the school-age sample. Conclusion: Verb morphology alone is not a useful clinical marker of SLI in school-age children. Potential explanations for these findings and ideas for future research are discussed

    The virtual human face – superimposing the simultaneously captured 3D photorealistic skin surface of the face on the untextured skin image of the CBCT Scan

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    The aim of this study was to evaluate the impact of simultaneous capture of the three-dimensional (3D) surface of the face and cone beam computed tomography (CBCT) scan of the skull on the accuracy of their registration and superimposition. 3D facial images were acquired in 14 patients using the Di3d (Dimensional Imaging, UK) imaging system and i-CAT CBCT scanner. One stereophotogrammetry image was captured at the same time as the CBCT and another one hour later. The two stereophotographs were then individually superimposed over the CBCT using VRmesh. Seven patches were isolated on the final merged surfaces. For the whole face and each individual patch; maximum and minimum range of deviation between surfaces, absolute average distance between surfaces, and standard deviation for the 90th percentile of the distance errors were calculated. The superimposition errors of the whole face for both captures revealed statistically significant differences (P=0.00081). The absolute average distances in both separate and simultaneous captures were 0.47mm and 0.27mm, respectively. The level of superimposition accuracy in patches from separate captures ranged between 0.3 and 0.9mm, while that of simultaneous captures was 0.4mm. Simultaneous capture of Di3d and CBCT images significantly improved the accuracy of superimposition of these image modalities

    Three-dimensional analysis of mandibular landmarks, planes and shape, and the symphyseal changes associated with growth and orthodontic treatment

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    OBJECTIVE: To test reliability of 3D mandibular landmarks, planes of reference and surfaces and assess their correlation to conventional 2D cephalometric measurements. To analyze changes in three-dimensional shape of the symphysis due to growth and orthodontic treatment. METHODS: This was a retrospective analysis of CBCTs of healthy orthodontic patients. 32 subjects were included, 16 males and 16 females. Mean ages of 10.6 ± 1.5 years and 15.0 ± 0.9 years before and after treatment, respectively. The mean follow up time was 4.3 years. Subjects free of any craniofacial anomalies, and no observable pathology on panoramic radiograph were. 15 subjects had CVM 1 and 17 subjects had CVM 2 before orthodontic treatment. All subjects had CVM 5 after orthodontic treatment. For the first phase, 3D mandibular landmark identifications were digitized. Planes and landmarks were constructed and compared with conventional 2D mandibular measurements. For the second phase, mandibles were isolated by removing surrounding structures. Pearson correlation and paired t-test were performed to test for correlation and differences between 2D and 3D measurements, respectively. Statistical analysis was performed using SAS 9.4. Software. MorphoJ software (Version 2.0, www.flywings.org.uk) was used for symphysis shape analysis; and Discriminant Function Analysis (DFA) between pre-treatment and post-treatment was used for statistical analysis of the symphysis. RESULTS: We found statistical significant positive correlation between 2D and 3D pre-treatment ramus height (P-value =0.01), post-treatment ramus height (P-value < 0.0001), pre-treatment corpus length (P-value 0.0003), post-treatment corpus length (P-value 0.04), pre-treatment gonial angle (P-value <0.0001), and post-treatment gonial angle (P-value=0.05). Also, statistically significant differences in 2D ramus height (P=0.001), 3D ramus height (P-value=0.002), 2D corpus length (P-value <0.01), and 3D corpus length (P-value <0.01). For symphysis shape comparing between pre-treatment and post-treatment, we found that there is no statistically significant difference between them (P-value= 0.99). CONCLUSION: These results demonstrated statistically significant positive correlation between certain 2D and 3D measurements, pre-treatment and post-treatment differences in 2D and 3D measurements showed consistent results. Symphysis shapes do break out as distinctly separate groups, but the differences between the means is small

    Anthropometric Study of the Human Craniofacial Morphology among different castes of Punjab Pakistan

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    Background: It appears from the literature that there is a research vacuum in craniofacial anthropometric studies in Pakistani population. Therefore, this study was carried out to characterize the craniofacial parameters among different castes of the Punjab Pakistan.Methods: This cross-sectional study was conducted on population of the Punjab, Pakistan, with age 18-45 years in a normal healthy state and data was collected using a questionnaire. Anthropometric instruments such as standard spreading caliper, round ended caliper, vernier caliper and scale were used for the measurement of craniofacial parameters. Data was analyzed by using SPSS version 20.0 and MS Excel 16. Morphological anthropometry of face, head, nose and ears was observed and noted.Results: Hyperleptoprosopic face was most common one in the studied population. The dominant nose type was Leptorrhine while the most dominant head shape was Dolichocephalic. The average ear index was 50.42 and 51.19 of right and left ears, respectively.Conclusion: This data is a base for the anthropometric data bank of the Punjab province of Pakistan. This data is helpful in medico legal cases, forensic investigations, and in facial surgeries. This study is also important for anthropological and forensic research.Keywords: Anthropology, Anthropometry; Craniofacial; Morphology; Populatio
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