The Influence of Texting Language on Grammar and Executive Functions in Primary School Children

When sending text messages on their mobile phone to friends, children often use a special type of register, which is called textese. This register allows the omission of words and the use of textisms: instances of non-standard written language such as 4ever (forever). Previous studies have shown that textese has a positive effect on children’s literacy abilities. In addition, it is possible that children’s grammar system is affected by textese as well, as grammar rules are often transgressed in this register. Therefore, the main aim of this study was to investigate whether the use of textese influences children’s grammar performance, and whether this effect is specific to grammar or language in general. Additionally, studies have not yet investigated the influence of textese on children’s cognitive abilities. Consequently, the secondary aim of this study was to find out whether textese affects children’s executive functions. To investigate this, 55 children between 10 and 13 years old were tested on a receptive vocabulary and grammar performance (sentence repetition) task and various tasks measuring executive functioning. In addition, text messages were elicited and the number of omissions and textisms in children’s messages were calculated. Regression analyses showed that omissions were a significant predictor of children’s grammar performance after various other variables were controlled for: the more words children omitted in their text messages, the better their performance on the grammar task. Although textisms correlated (marginally) significantly with vocabulary, grammar and selective attention scores and omissions marginally significantly with vocabulary scores, no other significant effects were obtained for measures of textese in the regression analyses: neither for the language outcomes, nor for the executive function tasks. Hence, our results show that textese is positively related to children’s grammar performance. On the other hand, use of textese does not affect—positively nor negatively—children’s executive functions.     

Analysis of low concentrations of 5-bromo-2-deoxyuridine on sister chromatid exchanges in human lymphocytes

To determine a concentration of 5-bromo-2-deoxyuridine (BrdU) sufficient for sister chromatid differentiation (SCD), and yet having a minimal effect on the number of sister chromatid exchanges (SCEs), we assessed the effect produced on the number of SCEs by low concentrations (1, 3, and 10 micrograms/mL) of BrdU. SCD was not obtained in 19% of the 31 subjects with 1 microgram/mL of BrdU, while the differentiation was adequate for all samples treated with 3 and 10 micrograms/mL. We statistically analysed the effects of these three different doses and found no significant difference in the number of SCEs obtained with the doses of 1 and 3 micrograms/mL, but a significant difference was observed between these two concentrations and 10 micrograms/mL. We therefore suggest that the dose of 3 micrograms/mL, while sufficient to produce reliable differential staining, still permits an adequate evaluation of the base line of SCEs and appears to enhance the sensitivity of the test to evaluate between-individual variations. Our experiments also underline that SCE counts should include the centromere exchanges.     

De novo t(2;13)(p24.3;q14.2) and retinoblastoma

Summary The two probes H3-8 and H2-42, known to be located in 13q14, were mapped by in situ hybridization to either side of the 13 breakpoint of an apparently balanced de novo t(2;13)(p24.3;q14.2) detected in a patient with retinoblastoma as the only phenotypic manifestation.     

Dynamic G- and R-banding of human chromosomes for electron microscopy

Synchronized human lymphocytes were exposed to 5-bromo-2-deoxyuridine (BrdUrd) for incorporation in either G-or R-bands. The substituted bands were revealed by monoclonal anti-BrdUrd antibodies disclosed with either gold-labeled antibodies or with the protein A-gold complex. Sharp G-or R-banding, specific for electron microscopy (EM), was obtained. These banding patterns, referred to as GB-AAu (G-bands by BrdUrd using Antibodies and gold [Au]) and RB-AAu (R-bands by BrdUrd using Antibodies and gold [Au]), resemble dynamic band patterns (GBG and RBG) much more than they do morphologic band patterns (GTG and RHG). The G- and R- band patterns allow accurate chromosome identification and karyotyping. An actual karyotype of human GB-AAu-banded chromosomes at the 750 band level, photographed in the EM, is presented. The method produces excellent band separation and band contrast. Variations in band staining intensities were noted and correlated with BrdUrd enrichment. The C-band regions were positively stained after GB-AAu banding while they were negatively stained after RB-AAu banding. Telomeres appeared heterogeneous after GB-AAu banding suggesting that part of the telomeric bands might be late replicating.     

The β heterochromatic sequences flanking the I elements are themselves defective transposable elements

Phylogenetic studies suggest that mobile element families are unstable components of the Drosophila genome. Two examples of immobilization of a transposable element family are presented here: as judged by their constant genomic organization among unrelated strains, the F and I element families have been respectively immobilized for a long time in D. simulans and in the reactive D. melanogaster strains (these are the laboratory strains which escaped the recent I invasion of D. melanogaster natural populations). All the elements of these defective families are located in the heterochromatic portion of the genome. Moreover, most if not all of the heterochromatic sequences into which the defective I elements are embedded are themselves non-mobile members of various nomadic families such as mdg 4, 297, 1731, F and Doc. These results are discussed with special emphasis on the possible nomadic origin of heterochromatin components and on the mechanisms of evolutionary turnover of the transposable element families.     

Viral and bacterial contamination of mussels (Mytilus edulis) exposed in an unpolluted marine environment

Bacteria indicating faecal contamination, cell-culturable enteroviruses and hepatitis A virus (HAV) were investigated in sea-water and in mussels exposed in an unpolluted marine environment, over a 7-month period with two samplings per month. Of the 16 mussel samples examined, none contained cell-culturable enteroviruses, four showed a low-level contamination by HAV and two did not conform to the current bacteriological norms. No connection was observed between the viral and bacterial contamination. No viral contamination was detected in the sea-water samples, but two gave bacterial counts above current norms.