Investigating low intelligence stereotype threat in adults with developmental dyslexia.

Stereotype threat (ST) is a phenomenon that leads to decreased test performance and occurs when one deals with added pressure of being judged on the basis of stereotyped group membership. The ST effect has been previously investigated in many contexts but not in individuals with dyslexia who are often stereotyped as less intelligent. Prevalent use of intelligence tests in job selection processes and employment gap between people with dyslexia and those without warrants this investigation. Sixty-three participants (30 with dyslexia and 33 without dyslexia; mean age = 33.7; SD = 13.7; 47 F, 13 M, three non-binary) were asked to complete intelligence test typically used in selection processes. All participants were randomly assigned to one of three test instruction conditions: (1) they were told the test was diagnostic of their intelligence (ST triggering instruction); (2) test was a measure of their problem-solving skills (reduced threat); (3) or they were simply asked to take the test (control). Results showed that participants with dyslexia in ST condition performed poorer than those in other conditions and those in the same condition who did not have dyslexia. This study provides preliminary evidence for diminishing effects of ST in individuals with dyslexia.

Migration of trace elements and radioisotopes to various fractions of solid wastes generated as a result of the sewage sludge incineration process.

The research was aimed at providing new knowledge in the field of chemical characteristics of solid waste generated in the process of combustion of sewage sludge in fluidized bed furnaces. The research material consisted of disposed fluidized beds (DFB), sewage sludge ash (SSA) and air pollution control residues (APC) from three Polish installations for the thermal treatment of sewage sludge. Natural radionuclides as well as anthropogenic isotope 137Cs were determined in the tested materials and the migration of a wide spectrum of trace elements to various waste fractions generated in the process of sewage sludge combustion was examined. It was observed that both radioisotopes and most of the trace elements determined accumulate in SSA and DFB, while the APC fraction contains a much smaller amount of them. The exceptions are mercury and selenium, whose volatile compounds migrate to the exhaust gas dedusting system and accumulate in the APC fraction (up to 40 mg/kg and 13 mg/kg, respectively). A potential threat from the 226Ra isotope in SSA is identified in the context of the management of this waste in the production of building materials because the typical activity of 226Ra in SSA collected from areas with very low Ra content in natural environment exceeds 1.5-6 times the activity of this isotope in conventional cement mixtures. When managing SSA and DFB, special attention should be paid to the content of metalloids such as As, B and Se, due to the high content of mobile forms of these elements in the mentioned materials.

Assessment of Natural Radioactivity in Cements Used as Building Materials in Poland.

It has been analyzed in this article the radioactivity concentrations of 226Ra, 232Th, 40K and radiological hazard parameters in different types of cements commonly used in Poland and available on the Polish market. The radiological hazard parameters are, in particular, absorbed gamma dose rate, annual effective dose, radium equivalent activity, the external hazard index, and the gamma and alpha indices. The radionuclide activities of the most important radionuclides 226Ra, 232Th, 40K have been determined by gamma-ray spectrometry with the use of two kinds of spectrometers of different operational parameters. One performed also measurements on 30-day and 45-day aged samples as to verify if there is a statistically significant difference in radioactivity concentration for shorter and longer aging time. The radioactivity concentrations in the cement samples ranged from 21.7-75.7 Bq·kg-1 for 226Ra, 12.3-47.3 Bq·kg-1 for 232Th to 123-430 Bq·kg-1 for 40K. The radiological parameters in cement samples were calculated as follows: mean radium equivalent activity Raeq = 127 Bq·kg-1, mean absorbed gamma dose rate D = 115 nGy·h-1, mean annual effective dose E = 570 µSv·y-1, external hazard index Hex = 0.32, internal hazard index Hin = 0.51, mean activity concentration index Iγ = 0.47 and mean alpha index Iα = 0.28. The results were compared with the reported data from other countries and the international standard values given by European Commission (EC) and United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000). Finally, thorough statistical analysis has been performed.

Assessment of the Natural Radioactivity of Polish and Foreign Granites Used for Road and Lapidary Constructions in Poland.

The measurements of the specific activity of natural radioactive isotopes of radium (226Ra), thorium (232Th) and potassium (40K) in chosen samples of imported (China, Finland, Spain, India, Sweden) and Polish (Izerski, Karkonosze, Siedlimowicki, Strzegomski, Strzelinski) granites were performed. The measurements were carried out with 2 × 2" NaI(Tl) scintillation detector. The measured specific activity on natural radioactive isotopes were within the following ranges: 5.8-312 [Bq kg-1], 5.5-189 [Bq kg-1] and 109-1590 [Bq kg-1] for 226Ra, 232Th and 40K, respectively. Obtained concentrations of radioactive isotopes allowed to perform the analysis of the exposure of the humans from the ionizing radiation emitted by the granites. The determination of the exposure consisted in the calculation of absorbed gamma dose rate (D) [nGy h-1] for each sample, which fell in the range between 20 and 511 [nGy h-1], annual effective dose rate (AED) [mSv year-1] ranging between 0.10 and 2.50 [mSv year-1], radium equivalent activity (Raeq) [Bq kg-1] with values between 22 and 570 [Bq kg-1], external and internal hazard indices (Hex) and (Hin) falling in the ranges 0.06-1.53 and 0.08-2.41 respectively, as well as gamma (Iγ) and alpha (Iα), representative level indices with values 0.08-2.0 and 0.029-1.56, respectively. Moreover, obtained results were compared with the international standard values given by the European Commission (EC), the United Nations Scientific Committee on the Effects of Atomic Radiation given in UNSCEAR Reports, and the results of research from other laboratories.

Beyond the global motion deficit hypothesis of developmental dyslexia: A cross-sectional study of visual, cognitive, and socio-economic factors influencing reading ability in children.

Although primarily conceptualized as a disorder of phonological awareness, developmental dyslexia is often associated with broader problems perceiving and attending to transient or rapidly-moving visual stimuli. However, the extent to which such visual deficits represent the cause or the consequence of dyslexia remains contentious, and very little research has examined the relative contributions of phonological, visual, and other variables to reading performance more broadly. We measured visual sensitivity to global motion (GM) and global form (GF), performance on various language and other cognitive tasks believed to be compromised in dyslexia (phonological awareness, processing speed, and working memory), together with a range of social and demographic variables often omitted in previous research, such as age, gender, non-verbal intelligence, and socio-economic status in an unselected sample (n = 132) of children aged 6-11.5 yrs from two different primary schools in Edinburgh, UK. We found that: (i) Mean GM sensitivity (but not GF) was significantly lower in poor readers (medium effect size); (ii) GM sensitivity accounted for only 3% of the variance in reading scores; (iii) GM sensitivity deficits were observed in only 16% of poor readers; (iv) the best predictors of reading performance were phonological awareness, non-verbal intelligence, and socio-economic status, suggesting the importance of controlling for these in future studies of vision and reading. These findings suggest that developmental dyslexia is unlikely to represent a single category of neurodevelopmental disorder underpinned by lower-level deficits in visual motion processing.