203 research outputs found
Optimum virtual environment for solving cognitive tasks by individuals with autism spectrum disorders: The questions and methods of design
The number of people with autism spectrum disorders (ASDs) is growing in Russia and the world at large. It is important to find ways to diagnose and correct the work with such individuals. There is much evidence that children with ASDs often exhibit pronounced communicative difficulties, problems in establishing visual contact etc. Specialists working with this category of patients face serious difficulties in trying to find effective ways to interact with them. The use of virtual reality environments that have the necessary parameters, determined theoretically, experimentally, and practically, can mitigate these difficulties. The study has shown that, at present, there is much experience in the field of virtual reality application while working with children who have ASDs. Nevertheless, there are several unspecified issues. First, as far as the perception of virtual reality by people with ASDs are concerned, it is especially important to study them. Of much importance are the peculiarities of their states associated with virtual reality, while solving cognitive tasks during diagnostic and corrective work stage, as well as in obtaining education. It is necessary to choose the right methods of visualization and interaction in a virtual environment. The focal point of the article is to justify the project of creating a virtual reality for the diagnosis and socialization of individuals with ASDs, i.e., its structure, stages and methods. In addition, the work is of interest in connection with the research of the phenomenon of presence in virtual reality. Ā© 2019 IJCRSEE. All rights reserved.The work was supported by act 211 Government of the Russian Federation, contract ā 02.A03.21.0006. The work was supported by RFBR
Opis krljuŔti hibrida Scardinius erythrophthatmus (Linneus, 1758.) x Leuciscus turskyi (Heckel, 1843.)
Theoretical study of metal borides stability
We have recently identified metal-sandwich (MS) crystal structures and shown
with ab initio calculations that the MS lithium monoboride phases are favored
over the known stoichiometric ones under hydrostatic pressure [Phys. Rev. B 73,
180501(R) (2006)]. According to previous studies synthesized lithium monoboride
tends to be boron-deficient, however the mechanism leading to this phenomenon
is not fully understood. We propose a simple model that explains the
experimentally observed off-stoichiometry and show that compared to such
boron-deficient phases the MS-LiB compounds still have lower formation enthalpy
under high pressures. We also investigate stability of MS phases for a large
class of metal borides. Our ab initio results suggest that MS noble metal
borides are less unstable than the corresponding AlB-type phases but not
stable enough to form under equilibrium conditions.Comment: 14 pages, 15 figure
Fermi level quantum numbers and secondary gap of conducting carbon nanotubes
For the single-wall carbon nanotubes conducting in the simplest tight binding
model, the complete set of line group symmetry based quantum numbers for the
bands crossing at Fermi level are given. Besides linear (k), helical (k'} and
angular momenta, emerging from roto-translational symmetries, the parities of U
axis and (in the zig-zag and armchair cases only) mirror planes appear in the
assignation. The helical and angular momentum quantum numbers of the crossing
bands never vanishes, what supports proposed chirality of currents. Except for
the armchair tubes, the crossing bands have the same quantum numbers and,
according to the non-crossing rule, a secondary gap arises, as it is shown by
the accurate tight-binding calculation. In the armchair case the different
vertical mirror parity of the crossing bands provides substantial conductivity,
though kF is slightly decreased.Comment: 6 pages, 2 figure
Vertebral Artery Hypoplasia ā Sex-Specific Frequencies in 36 Parent-Offspring Pairs
The major interest in vertebral artery (VA) hypoplasia comes from its possible connection
to migraines with aura as well as from the fact that it is one of the risk factors
for a stroke. Therefore, the aim of this preliminary study was to investigate the mode of
inheritance of VA hypoplasia. Initially, color Doppler of VA was performed in 64 firstand
second-degree relatives of 33 probands, and the presence of VA hypoplasia was confirmed
according to the already established criteria. Since a higher prevalence of VA
hypoplasia (15.6%) in probandsā relatives in comparison with 2.34% in the general population
of Croatia was indicative of a strong familial predisposition for this condition,
an analysis of family data by means of Pearsonās chi-square statistics has been performed.
In this analysis, the observed sex-specific frequencies of 36 parent-offspring
pairs composed only of affected parent and his/her (affected or non-affected) offspring
are compared to the frequencies as expected under eight proposed models. For both ā
autosomal and X-linked monogenetic inheritance ā four hypotheses have been chosen,
assuming that the individuals having the affected allele (in combination with a healthy
one) have 100%, 50%, 40% and 0% chances of developing VA hypoplasia. Out of eight
tested models only two ā completely dominant and completely recessive X-linked models
ā were rejected. But, from the six non-rejected models, goodness-of-fit statistics showed
that the hypothesis of X-linked inheritance of VA hypoplasia with the Ā»healthyĀ« allele being
stronger (60% effect on phenotype) ā almost perfectly fit the data ( 2 = 2.0023; df = 7;
p = 0.9597). Further research encompassing a more enlarged family sample is needed to
confirm the present findings
Nanomechanical Properties and Phase Transitions in a Double-Walled (5,5)@(10,10) Carbon Nanotube: ab initio Calculations
The structure and elastic properties of (5,5) and (10,10) nanotubes, as well
as barriers for relative rotation of the walls and their relative sliding along
the axis in a double-walled (5,5)@(10,10) carbon nanotube, are calculated using
the density functional method. The results of these calculations are the basis
for estimating the following physical quantities: shear strengths and diffusion
coefficients for relative sliding along the axis and rotation of the walls, as
well as frequencies of relative rotational and translational oscillations of
the walls. The commensurability-incommensurability phase transition is
analyzed. The length of the incommensurability defect is estimated on the basis
of ab initio calculations. It is proposed that (5,5)@(10,10) double-walled
carbon nanotube be used as a plain bearing. The possibility of experimental
verification of the results is discussed.Comment: 14 page
Odnos izmeÄu odabranih pokazatelja kompjutorski potpomognute analize sperme i plodnosti bikova
Computer Assisted Sperm Analysis (CASA) represents an objective, reproducible and reliable method of sperm quality assessment, however, not many reports exist that correlate its accuracy with bull semen fertility. The aim of this study was to evaluate the correlation between selected CASA motility parameters of cryopreserved bull semen and fertility. The total spermatozoa motility (SM %), the progressive spermatozoa motility (PSM %) as well as the percentage of spermatozoa with rapid movement (RAP %) were measured through CASA. All 12 ejaculates were collected from one Holstein Friesian bull. A total of 816 Holstein Friesian cows were used for artificial insemination (AI) and the evaluation of fertility. The fertility success was assessed by pregnancy rates per cycle (PRC %), 90 days after AI of the cows. The sperm variables that were associated with an increase in the PRC were the SM (R2 = 0. 6722), the PSM (R2 = 0. 6520) and the RAP (R2 = 0. 7103). RAP had a greater influence (P<0.001) on fertility (PRC), than SM and PSM (P<0.01). The increase of sperm motility parameters (SM, PSM and RAP) led to increased PRC, i.e. to increased fertility.Kompjutorski potpomognuta analiza sperme (CASA) predstavlja objektivan, ponovljiv i pouzdan naÄin procjene kvalitete spermija. No, malo je izvjeÅ”Äa u kojima se provjerava odnos izmeÄu njezine toÄnosti i plodnosti sjemena bikova. Cilj ovog istraživanja bio je procijeniti povezanost odabranih pokazatelja kompjutorski potpomognute analize pokretljivosti spermija iz zamrznute sperme bikova s njihovom plodnoÅ”Äu. Ukupna pokretljivost spermija (%), progresivna pokretljivost spermija (%), kao i postotak spermija s brzim kretanjem (%) procijenjeni su kompjutorski potpomognutom analizom sperme. Svih 12 ejakulata prikupljeni su od jednog holÅ”tajnsko-frizijskog bika. Ukupno je 816 holÅ”tajsnko-frizijskih krava koriÅ”teno za umjetno osjemenjivanje (UO) i procjenu plodnosti. Uspjeh plodnosti procijenjen je stopom gravidnosti po ciklusu (%), 90. dana nakon UO krava. Varijable spermija koje su povezane s poveÄanjem stope gravidnosti po ciklusu su pokretljivost spermija (R2 = 0,6722), progresivna pokretljivost spermija (R2 = 0, 6520) i stopa spermija s brzim kretanjem (R2 = 0, 7103). Spermiji s brzim kretanjem imali su veÄi utjecaj (P<0,001) na plodnost (PRC), od ukupne pokretljivosti spermija i progresivne pokretljivosti spermija (P<0,01). PoveÄanje vrijednosti pokazatelja pokretljivosti spermija (SM, PSM i RAP) dovelo je do poveÄane stope gravidnosti po ciklusu, tj. poveÄane plodnosti
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