155 research outputs found
Legibility of Textbooks: A Literature Review
AbstractThe purpose of the study was to analyse findings in the field of the textbooks’ legibility, readability and visual word recognition. The paper focuses on the most significant findings for comprehending the texts’ spatial characteristics during reading, word and letter recognition. The aim of the study was to analyse the factors which have induced inconsistencies between the findings acquired by scientists, as well as to compare findings which continually lead to progression in this field
Extreme plasma states in laser-governed vacuum breakdown
Triggering vacuum breakdown at the upcoming laser facilities can provide
rapid electron-positron pair production for studies in laboratory astrophysics
and fundamental physics. However, the density of the emerging plasma should
seemingly stop rising at the relativistic critical density, when the plasma
becomes opaque. Here we identify the opportunity of breaking this limit using
optimal beam configuration of petawatt-class lasers. Tightly focused laser
fields allow plasma generation in a small focal volume much less than
, and creating extreme plasma states in terms of density and
produced currents. These states can be regarded as a new object of nonlinear
plasma physics. Using 3D QED-PIC simulations we demonstrate the possibility of
reaching densities of more than cm, which is an order of
magnitude higher than previously expected. Controlling the process via the
initial target parameters gives the opportunity to reach the discovered plasma
states at the upcoming laser facilities
Complex research on the interaction of glass with space debris
This paper discusses the interactions of barriers with a spherical impactor and the character of possible deformation and fragmentation of barriers and impactors. The destruction of glass is considered as a process of destruction of fragile material without a part of plastic deformation characteristic of the deformation metals. To calculate the elastic-plastic flow a technique was used which was implemented on the tetrahedral cells and based on the combined use of the Wilkins method for calculating the interior points of the body and the Johnson method for calculating contact interactions. Methods for accelerating the flow of fine particles and the individual spherical particles have been developed. A series of experiments for usual glass and glass with coatings has been carried out
“Whatdunit?” Developmental changes in children\u27s syntactically based sentence interpretation abilities and sensitivity to word order
Aim 1 of this study was to examine the developmental changes in typically developing English-speaking children’s syntactically-based sentence interpretation abilities and sensitivity to word order. Aim 2 was to determine the psychometric standing of the novel sentence interpretation task developed for this study, as we wish to use it later with children with Specific Language Impairment (SLI). Children listened to semantically implausible sentences in which noun animacy and the natural affordance between the nouns were removed, thus controlling for event probability. Using this novel “whatdunit?” agent selection task, 256 children 7-11 years listened to two structures with canonical word order and two with non-canonical word order. After each sentence, children selected as quickly as possible the picture of the noun they believed was “doing the action.” Children interpreted sentences with canonical word order with greater accuracy and speed than those with non-canonical word order. Older children (AgeM = 10:8) were more accurate and faster than younger children (AgeM = 8:1) across all sentence forms. Both older and younger children demonstrated similar error patterns across sentence type. The “whatdunit?” task also proved to have strong validity and reliability, making it suitable for studies with children with SLI
Feedback Control of Second Messengers Signaling Systems in White Adipose Tissue Adipocytes in Healthy State and Its Loss at Adiposity
Second messengers Ca2+, IP3, cAMP, NO, cGMP, and cADP ribose are incorporated as obligatory elements into multivariable Ca2+-signaling system, which integrates incoming signals of hormones and neurotransmitters in white adipocytes. This cross-controlled system includes two robust generators (RGs) of rhythmic processes, involving phospholipase C- and NO-synthase-dependent signaling networks (PLC-RG and NOS-RG). Multi-loop positive feedback control of both RGs provides their robustness, multistability, signaling interplay, and extreme sensitivity to the alterations of incoming signals of acetylcholine, norepinephrine, insulin, cholecystokinin, atrial natriuretic peptide, bradykinin, and so on. Hypertrophy of cultured adipocytes and of mature cells, isolated from epididymal white adipose tissue (eWAT), results in the loss of rhythmicity and development of general hormonal signaling resistance. Preadipocytes isolated from eWAT of obese mice cannot grow and accumulate lipids in the media devoid of fatty acids. However, even low concentrations of palmitoylcarnitine in the media (1 μM) may result in drastic suppression of mRNA expressions of the proteins of Ca2+-signaling system, especially of NOS-RG. Similar alterations of gene expression are observed in eWAT and liver at adiposity. All this may indicate on universal background pathogenic mechanisms. Treatment modalities, which may help to restore deregulation of Ca2+-signaling system and corresponding tissues dysfunction, are discussed briefly
Hospitalization Rates for Coronary Heart Disease in Relation to Residence Near Areas Contaminated with Persistent Organic Pollutants and Other Pollutants
Exposure to environmental pollutants may contribute to the development of coronary heart disease (CHD). We determined the ZIP codes containing or abutting each of the approximately 900 hazardous waste sites in New York and identified the major contaminants in each. Three categories of ZIP codes were then distinguished: those containing or abutting sites contaminated with persistent organic pollutants (POPs), those containing only other types of wastes (“other waste”), and those not containing any identified hazardous waste site (“clean”). Effects of residence in each of these ZIP codes on CHD and acute myocardial infarction (AMI) hospital discharge rates were assessed with a negative binomial model, adjusting for age, sex, race, income, and health insurance coverage. Patients living in ZIP codes contaminated with POPs had a statistically significant 15.0% elevation in CHD hospital discharge rates and a 20.0% elevation in AMI discharge rates compared with clean ZIP codes. In neither of the comparisons were rates in other-waste sites significantly greater than in clean sites. In a subset of POP ZIP codes along the Hudson River, where average income is higher and there is less smoking, better diet, and more exercise, the rate of hospitalization for CHD was 35.8% greater and for AMI 39.1% greater than in clean sites. Although the cross-sectional design of the study prevents definite conclusions on causal inference, the results indirectly support the hypothesis that living near a POP-contaminated site constitutes a risk of exposure and of development of CHD and AMI
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