The evolvement of duplicated gene loci in allopolyploid plants has become the subject of intensive studies. Most duplicated genes remain active in neoallopolyploids contributing either to a ...favourable effect of an extra gene dosage or to the build-up of positive inter-genomic interactions when genes or regulation factors on homoeologous chromosomes are divergent. However, in a small number of loci (about 10%), genes of only one genome are active, while the homoeoalleles on the other genome(s) are either eliminated or partially or completely suppressed by genetic or epigenetic means. For several traits, the retention of controlling genes is not random, favouring one genome over the other(s). Such genomic asymmetry is manifested in allopolyploid wheat by the control of various morphological and agronomical traits, in the production of rRNA and storage proteins, and in interaction with pathogens. It is suggested that the process of cytological diploidization leading to exclusive intra-genomic meiotic pairing and, consequently, to complete avoidance of inter-genomic recombination, has two contrasting effects. Firstly, it provides a means for the fixation of positive heterotic inter-genomic interactions and also maintains genomic asymmetry resulting from loss or silencing of genes. The possible mechanisms and evolutionary advantages of genomic asymmetry are discussed.
Bismuth ferrite nanopowders doped with holmium ions were synthesized by spray pyrolysis. By means of the TEM and SEM methods, it was established that Ho
x
Bi
1-
x
FeO
3
particles have dimensions in ...the range of 50–170 nm and are agglomerated into spherical formations with a size of 1.5–3 μm. A decrease in the lattice parameters and unit cell volume of holmium-doped bismuth ferrite samples was shown, and the EDX data confirm the incorporation of holmium ions into the positions of bismuth ions in the BiFeO
3
lattice. Doping of bismuth ferrite with holmium ions led to a significant increase in the saturation magnetisation and residual magnetisation in comparison with undoped BiFeO
3
, while the coercive force decreased. Magnetic characteristics of Ho
x
Bi
1-
x
FeO
3
samples demonstrated strong dependence on temperature, and the dielectric permittivity in the frequency range up to 200 kHz remains practically unchanged. Magnetocapacitance values in fields up to 5 × 10
5
A/m did not exceed a tenth of a percent, which is associated with a high dispersion of nanopowders. The values of M
s
and M
r
obtained for Ho
x
Bi
1-
x
FeO
3
open up prospects for using this material for the development of magnetic field sensors, memory cells, and spintronic devices.
Phenotypic plasticity is the variation in phenotypic traits produced by a genotype in different environments. In contrast, environmental canalization is defined as the insensitivity of a genotype's ...phenotype to variation in environments. Despite the extensive literature on the evolutionary significance and potential genetic mechanisms driving plasticity and canalization, few studies tried to unravel the genetic basis of this phenomenon. Using both simulations and real data from barley (Hordeum vulgare), we used QTL mapping to obtain insights into the genetics of phenotypic plasticity. We explored two ways of quantifying phenotypic plasticity, namely the phenotypic variance across environments and the Finlay-Wilkinson's regression slope. Each relates to a different concept of stability. Through QTL detection with real and simulated data, we show that each measure of plasticity detects specific types of plasticity QTL. Most of the plasticity QTLs were detected in the data set with the lowest number of environments. All plasticity QTL co-located with loci showing QTL E interaction and there were no QTL that only affected plasticity. The number of environments that are considered and their homogeneity is a key to interpret the genetic control of phenotypic plasticity. Regulatory pathways of plasticity may vary from one set of environments to another due to unique features of each environment. Therefore, with an increasing number of environments, it may become impossible to detect a single 'consistent' regulatory pathway for all environments.
Assessment of quality and safety of red caviar of salmon fish Korol-Bezpala, L.; Bezpalyi, I.; Bondarenko, L. ...
Naukovij vìsnik Lʹvìvsʹkogo nacìonalʹnogo unìversitetu veterinarnoï medicini ta bìotehnologìj ìmenì S.Z. Gžicʹkogo. Serìâ: Harčovì tehnologìï,
04/2024, Letnik:
26, Številka:
101
Journal Article
Recenzirano
Odprti dostop
The health of the body largely depends on the necessary goods in the human diet. Therefore, quality and safety indicators are essential in monitoring their suitability. Red salmon caviar is no ...exception; it is considered a valuable food product and, due to its high price – a delicacy. Typically, this type of product must meet all regulatory requirements, which allows it to be safely used in the human diet. In terms of nutritional value, red caviar contains complete proteins, easily digestible fats, minerals, and vitamins, and its content is superior to that of some types of food products, even fish meat. The article presents the results of studies of organoleptic, physico-chemical, and microbiological indicators and the content of preservatives in salmon red granular salted caviar of 1st and 2nd grades sold in retail chains and markets in the Kyiv region. The study was carried out in laboratory conditions at the Research Institute of Food Technologies and Technologies for processing livestock products of the BNAU and the central testing state laboratory of the State Consumer Service (Vishnevoe). All indicators were determined using different methods intended for each indicator. Therefore, it was found that the organoleptic indicators of red caviar in both varieties corresponded to standard values. The mass fraction of sodium chloride and hexamine was within the normal range and did not exceed the standard indicators: sodium chloride – 8,57 % and 7,14 %, respectively (grades 1 and 2); methenamine – 70 % and 60 %, respectively (grades 1 and 2). According to microbiological indicators, the experimental samples showed that the number of MAFAnM did not exceed 1×102 CFU/g in both varieties, and the presence of yeast and mold fungi was detected no more than 10 CFU 1,0 g, which is 3 times less than the norm. The content of preservatives E200 1st and 2nd grades of red caviar was 0,07 % and 0,04 %, and E210 (1st and 2nd grades) 0,05 % and 0,03 %. Thus, all studied samples of red granular salmon caviar meet standard values for all indicators of quality and food safety.
•Thermodynamic model of single-phase high entropy alloys formation was developed.•Single-phase TiVZrNbTa equiatomic alloy was synthesized by various techniques.•Effect of synthesis method on alloy ...hydrogenation behavior was examined.•Alloy synthesis from melt results in improved stability upon hydrogenation.
A thermodynamic model was proposed to assess the feasibility of the synthesis of single-phase multi-principal-component alloy. Based on this model, single-phase TiVZrNbTa equiatomic alloys with body centered cubic (BCC) structure were obtained by arc melting (AM), electron beam melting with pendant drop melt extraction (EBM-PDME) and mechanical alloying (MA). The alloys were characterized by powder X-ray diffraction, scanning and transmission electron microscopy, thermal analysis and mechanical testing. The hydrogenation behavior of the synthesized materials was studied by a volumetric method. It was found that for AM and EBM-PDME alloys a complete BCC-to-FCC structure transformation occurs upon hydrogenation, and hydrogen concentration in the hydrides formed reaches 1.5 H/M (1.6 wt%). MA alloy undergoes partial amorphization with maximum hydrogen absorption capacity of 0.9 wt%.
Herein we report a simple and easily scalable method for fabricating ZnO/
-BN composites with tunable photoluminescence (PL) characteristics. The
-BN support significantly enhances the ultraviolet ...(UV) emission of ZnO nanoparticles (NPs), which is explained by the ZnO/
-BN interaction and the change in the electronic structure of the ZnO surface. When
-BN NPs are replaced with
-BN microparticles, the PL in the UV region increases, which is accompanied by a decrease in visible light emission. The dependence of the PL properties of ZnO NPs on the thickness of
-BN carriers, observed for the first time, is explained by a change in the dielectric constant of the support. A quantum chemical analysis of the influence of the
-BN thickness on the electron density redistribution at the
ZnO/
-BN interface and on the optical properties of the
ZnO/
-BN composites was carried out. Density functional theory (DFT) calculations show the appearance of hybridization at the
-BN/
ZnO interface and an increase in the intensity of absorption peaks with an increase in the number of h-BN layers. The obtained results open new possibilities for controlling the properties of ZnO/
-BN heterostructures for various optical applications.
•Metal-polymer composite membranes have been prepared via MA.•Composite membranes consist of LaNi5-type alloy and polyethylene.•Addition of metal filler leads to a drop of the phase transition ...activation energy.•Hydrogen processing results in a shift of the internal friction peak.
In the present work, mechanical properties of metal-polymer composite membranes for hydrogen separation have been investigated by tensile test and mechanical spectroscopy methods. The membranes were prepared by high-energy ball milling and subsequent thermal pressing of a powder mixture of polyethylene with 10 wt% hydride-forming intermetallic compound LaNi2.5Co2.4Mn0.1. The membranes were then subjected to activation by long exposure in a hydrogen atmosphere. The static tensile test showed a slight decrease in membrane tensile strength after hydrogen activation that may be explained by intermetallic particle embrittlement. Mechanical spectroscopy study reveals a shift of the internal friction peak of the activated membrane by 22 K towards lower temperatures and a small decrease of the activation energy of polyethylene viscoelastic transformation from 144 kJ/mol to 138 kJ/mol.
A neural network method has been proposed to calculate the configurations and energies of the ground states of the Edwards–Anderson spin glass model with periodic boundary conditions. The macroscopic ...degeneracy of the ground states and violation of translational symmetry have been observed. Comparison with the results obtained by the exact and approximate computational methods confirms the reliability of the results.
A
bstract
The cross section of the process
e
+
e
−
→
π
+
π
−
has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000
e
+
e
−
collider VEPP-2000 in the energy region 525
...<
s
<
883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb
−
1
. The systematic uncertainty of the cross section determination is 0.8% at
s
>
0
.
600 GeV. The
ρ
meson parameters are obtained as
m
ρ
= 775
.
3 ± 0
.
5 ± 0
.
6 MeV, Γ
ρ
= 145
.
6 ± 0
.
6 ± 0
.
8 MeV,
B
ρ
→
e
+
e−
×
B
ρ
→
π
+
π−
= (4
.
89 ± 0
.
02 ± 0
.
04) × 10
−
5
, and the parameters of the
e
+
e
−
→
ω
→
π
+
π
−
process, suppressed by
G
-parity, as
B
ω
→
e
+
e−
×
B
ω
→
π
+
π−
= (1
.
32 ± 0
.
06 ± 0
.
02) × 10
−
6
and and
ϕ
ρω
= 110
.
7 ± 1
.
5 ± 1
.
0 degrees.
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