Academy of Sciences of the Czech Republic

About: Academy of Sciences of the Czech Republic is a government organization based out in Prague, Czechia. It is known for research contribution in the topics: Population & Catalysis. The organization has 27866 authors who have published 71021 publications receiving 1821686 citations.

Mean length of utterance levels in 6-month intervals for children 3 to 9 years with and without language impairments.

Abstract: Purpose The mean length of children’s utterances is a valuable estimate of their early language acquisition. The available normative data lack documentation of language and nonverbal intelligence levels of the samples. This study reports age-referenced mean length of utterance (MLU) data from children with specific language impairment (SLI) and children without language impairments. Method Of the 306 child participants drawn from a data archive, ages 2;6–9;0 (years;months), 170 were in the SLI group and 136 were in the control group. There were 1,564 spontaneous language samples collected, and these were transcribed and analyzed for sample size and MLU in words and morphemes. Means, standard deviations, and effect sizes for group differences are reported for MLUs, along with concurrent language and nonverbal intelligence assessments, per 6-month intervals. Results The results document an age progression in MLU words and morphemes and a persistent lower level of performance for children with SLI. Conclusio...

Returns to Human Capital under the Communist Wage Grid and During the Transition to a Market Economy

Abstract: Under communism, workers had their wages set according to a centrally-determined wage grid. In this paper we use new micro data on men to estimate returns to human capital under the communist wage grid and during the transition to a market economy. We use data from the Czech Republic because it is a leading transition economy in which the communist grid remained intact until the very end of the communist regime. We demonstrate that for decades the communist wage grid maintained extremely low rate of return on education, but that the return increased dramatically and equally in all ownership categories of firms during the transition. Our estimates also indicate that men?s wage-experience profile was concave in both regimes and on average it did not change from the communist to the transition period. However, the de novo private firms display a more oncave profile than SOEs and public administration. Contrary to earlier studies, we show that men?s inter-industry wage structure changed substantially between 1989 and 1996.

Exchange interactions in III-V and group-IV diluted magnetic semiconductors

Abstract: Effective pair exchange interactions between Mn atoms in III-V and group-IV diluted magnetic semiconductors are determined from a two-step first-principles procedure. In the first step, the self-consistent electronic structure of a system is calculated for a collinear spin structure at zero temperature with the substitutional disorder treated within the framework of the coherent-potential approximation. The effective exchange pair interactions are then obtained in a second step by mapping the total energies associated with rotations of magnetic moments onto an effective classical Heisenberg Hamiltonian using the magnetic force theorem and one-electron Green functions. The formalism is applied to ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ alloys with and without As antisites, and to ${\mathrm{Ge}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}$ alloys recently studied experimentally. A detailed study of the behavior of pair exchange interactions as a function of the distance between magnetic atoms as well as a function of the concentrations of the magnetic atoms and compensating defects is presented. We have found that due to disorder and the half-metallic character of the system the pair exchange interactions are exponentially damped with increasing distance between the Mn atoms. The exchange interactions between Mn atoms are ferromagnetic for distances larger than the ones corresponding to the averaged nearest-neighbor Mn-Mn distance. The pair exchange interactions are also reduced with increasing concentrations of the Mn atoms and As antisites. As a simple application of the calculated exchange interactions we present mean-field estimates of Curie temperatures.

The burden of heat-related mortality attributable to recent human-induced climate change

Abstract: Climate change affects human health; however, there have been no large-scale, systematic efforts to quantify the heat-related human health impacts that have already occurred due to climate change. Here, we use empirical data from 732 locations in 43 countries to estimate the mortality burdens associated with the additional heat exposure that has resulted from recent human-induced warming, during the period 1991-2018. Across all study countries, we find that 37.0% (range 20.5-76.3%) of warm-season heat-related deaths can be attributed to anthropogenic climate change and that increased mortality is evident on every continent. Burdens varied geographically but were of the order of dozens to hundreds of deaths per year in many locations. Our findings support the urgent need for more ambitious mitigation and adaptation strategies to minimize the public health impacts of climate change.