Homology of labial chaetae in Entomobryoidea (Collembola)

The labium in Collembola consists of three parts (Folsom 1899): labial palp, basomedian (submentum) and basolateral (mentum) fields. Labial chaetotaxy, i.e. number, nature and relative position of chaetae, has been one of the standard descriptive components for species diagnoses in Entomobryoidea. Labial palp, including labial papillae, guard chaetae and proximal chaetae, has been well investigated across major collembolan lineages by Fjellberg (1999). For the chaetae behind the labial palp (mentum and submentum, Figs 1‒2) in Entomobryoidea, Gisin (1964) introduced the nomenclature of a1‒a5 for the anterior row and M1M2rEL1L2 for the posterior row in Lepidocyrtus; the lowercase letter r represented a smaller chaeta between M and E. Later, Gisin (1967) applied this system to Pseudosinella but defined uppercase and lowercase letters as ciliate and smooth chaetae, respectively. Chen & Christiansen (1993) mostly followed Gisin’s nomenclature but named the anterior row as A, B, C, D and F. When there was more than one chaeta inner to R, M-series, they were designated as M1, M2, Ms (supplementary) etc. Smooth chaeta r was sometimes named as ‘v’ (vestigial) in Lepidocyrtinae when it was very tiny. Because the degree of plurichaetosis on submentum greatly differs among Entomobryoidea species, homology of basomedian chaetae may be incorrectly recognized in adults. In this study, we observed labial chaetotaxy (guard chaetae of labial palp excluded) of early instars in twenty species, clarified their homologies and unified the nomenclature systems.

Variability of the language norm in the functioning of toponyms: Problems and contradictions

The article examines the linguistic content of the language norm related to the spelling of geographic proper names. As the basic notion, the authors use Ludmila Verbitskaya’s definition of the norm recognizing orthographic standards as a particular case of a language norm. The significance of a research in this area is due, firstly, to specificities of spelling norms, and secondly, difficulties of proper name codification. The orthographic norms are characterized by a significantly higher degree of strictness in comparison with other types of linguistic standards, hence, the avoidance of toponymic orthographic doublets creating problems in place-name identification. Normally, place names are not present in popular orthographic dictionaries and other non-specialized lexicographic sources. Not infrequently, the spelling of a particular locality in a codified form can only be found either on geographical maps and atlases or in gazetteers and registries of geographical names of a particular region. As a result, the spelling norm becomes established in the the native speakers’ linguistic competence primarily through the assimilation and application of the corresponding rules. It was revealed that the most significant contradictions in the implementation of the spelling norm take place when choosing an upper- or lowercase letter in compound proper names, as well as when representing the elements of compounds (separately, as one word or hyphenated). The resultss of the present research can be used in revision of orthography of both existing and newly formed place names to make them concordant with the principles of linguistic ecology

Measuring Sustained Attention and Perceived Workload

Objective: We examined the effects of spatial uncertainty, field dependence/independence (FD/I), and sex on vigilance performance and perceived workload in elementary school children. Background: Building on previous work in which children demonstrated their ability to evaluate workload, we tested whether spatial-uncertainty manipulations in a vigilance task would elicit in children the same deleterious effects on performance and workload as it does with adults. We also examined individual difference effects associated with FD/I and sex to determine their influence on both performance and workload. Method: In the low-uncertainty task, stimuli appeared in the center of the computer screen; in the high-uncertainty task, they appeared in one of the four quadrants of the screen. Neutral events consisted of uppercase letter strings. Critical signals consisted of a single lowercase letter among uppercase letters. Following each vigil, children completed a workload assessment via a modified version of the NASA Task Load Index. Results: Children showed lower perceptual sensitivity, greater response latency variability (RTSD), and a higher response criterion in the uncertain display condition. Workload scores reflected these performance differences. Field-dependent children showed lower perceptual sensitivity and greater RTSD than did field-independent children. The two groups exhibited differing workload profiles. Despite no objective performance differences, boys reported greater workload than girls. Conclusion: The scale demonstrated sensitivity and diagnosticity with regard to both the task variable and individual differences. Application: These findings contribute to the emerging field of “educational ergonomics” and indicate that appropriate assessment tools might identify children who are experiencing increased workload.

Assessing Early Literacy With Hispanic Preschoolers: The Factor Structure of the Phonological Awareness Literacy Screening—Español

For two decades, it has been recommended that assessment of literacy for preschool children be conducted in a child’s primary language. However, only a few literacy assessments have been validated with a preschool, Spanish-speaking population. The purpose of the present study was to test the latent structure of the Phonological Awareness Literacy Screening for Preschool (PALS-PreK) Español with a sample of Spanish-speaking children in the southwestern United States. Children who could recognize at least 16 uppercase and nine lowercase letters were included in the analyses. Subscales of the PreK Español included Name Writing, Letter/Sound Association, Print Concepts, and Rhyme Awareness. Confirmatory factor analysis resulted in a two-factor model of alphabet knowledge (upper and lowercase letter recognition, letter sounds) and print and phonological awareness (name writing, print and rhyme awareness, letter sounds) with letter sounds loading on both factors. We found that the structure of PALS-PreK Español is similar to the English version and discussed implications.

Influence of Immediate Dentin Sealing Techniques on Cuspal Deflection and Fracture Resistance of Teeth Restored with Composite Resin Inlays

SUMMARY This research evaluated the influence of immediate dentin sealing (IDS) techniques on cuspal deflection and fracture resistance of teeth restored with composite resin inlays. Forty-eight maxillary premolars were divided into four groups: G1, sound teeth (control); G2, without IDS; G3, IDS with Clearfil SE Bond (CSE); and G4, IDS with CSE and Protect Liner F. The teeth from groups 2, 3, and 4 received mesio-distal-occlusal preparations. The impressions were made with vinyl polysiloxane, followed by provisional restoration and storage in water for seven days. The impressions were poured using type IV die stone, and inlays with Filtek Z250 composite resin were built over each cast. The inlays were luted with Panavia F. After storage in water for 72 hours, a 200-N load was applied on the occlusal surface using a metal sphere connected to a universal testing machine, and the cuspal deflection was measured with a micrometer. The specimens were then submitted to an axial load until failure. The following mean cuspal deflection (μm) and mean fracture resistance (N) followed by the same lowercase letter represent no statistical difference by analysis of variance and Tukey (p<0.05): cuspal deflection: G1, 3.1 ± 1.5a; G2, 10.3 ± 4.6b; G3, 5.5 ± 1.8ac; and G4, 7.7 ± 5.1bc; fracture resistance: G1, 1974 ± 708a; G2, 1162 ± 474b; G3, 700 ± 280b; and G4, 810 ± 343b. IDS with CSE allowed cuspal deflection comparable with that associated with sound teeth. The application of Protect Liner F did not contribute to a decrease in cuspal deflection. The IDS techniques did not influence the fracture resistance of teeth.

Effect of Bleaching Agents on the Flexural Strength of Bovine Dentin

ABSTRACT The aim of this study was to evaluate the effect of bleaching on the flexural strength of bovine dentin, using bleaching agents containing calcium (Whiteness HP Blue and Whiteness Class) and not containing calcium (Whiteness HP and Whiteness Perfect). Sixty bovine incisor tooth slices were obtained and divided into five experimental groups (n = 12), such as G1, untreated control group; G2, Whiteness HP Max [35% hydrogen peroxide (HP)]; G3, Whiteness HP Blue (35% HP); G4, Whiteness Class (7.5% HP) and G5, Whiteness Perfect (22% carbamide peroxide). Samples were submitted to bleaching treatment according to the manufacturers’ instructions. The control group remained in artificial saliva during bleaching. After bleaching, the enamel was removed and dentin specimens (7 mm length × 1.7 mm width × 0.5 mm thickness) were prepared. Samples were tested in a universal testing machine (EMIC). Data were analyzed by analysis variance (ANOVA) and Tukey's test. Differences between the groups were identified by ANOVA. The mean values (± standard deviation) for the experimental groups, such as (in MPa) G1 = 19.05 ± 2.68 a; G2 = 12.69 ± 4.52 b; G3 = 16.39 ± 3.74 ab; G4 = 14.90 ± 5.60 ab; and G5 = 12.71 ± 2.25 b. Groups with the same lowercase letter were significantly different from each other. The presence of calcium in bleaching agents appeared to influence the flexural strength of bovine dentin after bleaching treatment, for both office bleaching (35% HP) and home bleaching (7.5% HP). How to cite this article Berger SB, Pazenhagen R, Martinelli N, Moura SK, de Carvalho RV, Guiraldo RD. Effect of Bleaching Agents on the Flexural Strength of Bovine Dentin. J Contemp Dent Pract 2014;15(5):552-555.

Factors associated with lowercase alphabet naming in kindergarteners

ABSTRACTWe investigated five hypotheses related to the successful naming of lowercase letters. Participants included 5,020 first-time kindergarteners from economically disadvantaged homes who previously attended publicly funded preschools. Results analyzed using three-level logistic regression showed that children have a higher probability of correctly identifying letters that appear in their own name and letters that appear frequently in print. In addition, lowercase letter shape similarity to its uppercase counterpart and letter order were also associated with the correct identification of the letter. Finally, if a lowercase letter had a visual and phonological resemblance to other letters, students had a lower probability of identifying the letter correctly. Implications for instruction are discussed.

A Brief and Informationally Rich Naming System for Oligosaccharide Motifs of Heteroxylans Found in Plant Cell Walls

The one-letter code system proposed here is a simple method to accurately describe structurally diverse oligosaccharides derived from heteroxylans. Substitutions or ‘molecular decoration(s)’ of main-chain d-xylosyl moieties are designated by unique letters. Hence, an oligosaccharide is described by a series of single letters, beginning with the non-reducing d-xylosyl unit. Superscripted numbers are used to indicate the linkage position(s) of main-chain substitution(s) and, where necessary, superscripted lowercase letter(s) indicate the nature of non-glycosidic groups (e.g., methyl, acetyl, or phenolic derivative moieties) that can be present on the substituents. Although relatively simple and practical to use, this abbreviated system lends itself to the naming of a large number of different combinations of structural building blocks and substituents. In its present state, this system is, therefore, adequate to name and differentiate all currently known complex oligosaccharides derived from heteroxylans and is sufficiently flexible to accommodate new structures as they become available.