Uzhhorod National University

About: Uzhhorod National University is a education organization based out in Uzhhorod, Ukraine. It is known for research contribution in the topics: Raman spectroscopy & Laser. The organization has 1089 authors who have published 1056 publications receiving 5187 citations. The organization is also known as: State Higher Education Establishment "Uzhhorod National University" & Uzhhorod State University.

Hydrostatic pressure effect on the optical spectra of glass-embedded CdS1-xSex nanocrystals

Abstract: Effect of hydrostatic pressure on the optical absorption spectrra of CdS1-xSex nanocrystals embedded in borosilicate glass matrix, is studied. A pressure-induced blue shift of the optical absorption edge and confinement-related maxima is observed. Energy band gap pressure variation coefficients are determined, their compositional and size behaviour being discussed in view of possible structural difference within the nanocrystal ensemble.

Slow light of dark pulses in a photorefractive crystal

Abstract: This paper demonstrates how dark pulses may be decelerating in a photorefractive crystal at room temperature. The authors show the conditions that allow to achieve delay larger than the input dark pulse width. When the input pulse duration is close to the crystal response time, the fractional delay is close to unity.

Genomes of Three Closely Related Caribbean Amazons Provide Insight for Species History and Conservation

Abstract: Islands have been used as model systems for studies of speciation and extinction since Darwin published his observations about finches found on the Galapagos. Amazon parrots inhabiting the Greater Antillean Islands represent a fascinating model of species diversification. Unfortunately, many of these birds are threatened as a result of human activity and some, like the Puerto Rican parrot, are now critically endangered. In this study we used a combination of de novo and reference-assisted assembly methods, integrating it with information obtained from related genomes to perform genome reconstruction of three amazon species. First, we used whole genome sequencing data to generate a new de novo genome assembly for the Puerto Rican parrot (Amazona vittata). We then improved the obtained assembly using transcriptome data from Amazona ventralis and used the resulting sequences as a reference to assemble the genomes Hispaniolan (A. ventralis) and Cuban (Amazona leucocephala) parrots. Finally, we, annotated genes and repetitive elements, estimated genome sizes and current levels of heterozygosity, built models of demographic history and provided interpretation of our findings in the context of parrot evolution in the Caribbean.

A criterion for testing hypotheses about the covariance function of a stationary Gaussian stochastic process

Abstract: We consider a measurable stationary Gaussian stochastic process. A criterion for testing hypotheses about the covariance function of such a process using estimates for its norm in the space $L_p(\mathbb {T}),\, p\geq1$, is constructed.