Hybrid Pair Research Articles

Certain New Development to the Orthogonal Binary Relations

In this study, inspired by the concept of B-metric-like space (BMLS), we introduce the concept of orthogonal B-metric-like space (OBMLS) via a hybrid pair of operators. Additionally, we establish the concept of orthogonal dynamic system (ODS) as a generalization of the dynamic system (DS), which improves the existing results for analysies such as those presented here. By applying this, some new refinements of the F⊥-Suzuki-type (F⊥-ST) fixed-point results are presented. These include some tangible instances, and applications in the field of nonlinear analysis are given to highlight the usability and validity of the theoretical results.

Performance evaluation of compound parabolic solar collector using different nanofluids: An experimental study

The article reports an experimental study on a non-tracking compound parabolic collector (CPC) with nanofluid and hybrid nanofluids (NFs). An experimental setup was fabricated having a concentration ratio of 4.17, 0.828 m2 collector area, 24° of half acceptance angle, and an evacuated tube receiver having 1.85 m length. Fluids like water and NFs have been investigated in CPC performance improvement, but current research deals with NFs and hybrid NFs in a CPC as rare studies are found on a CPC using NFs. The 0.010 and 0.015 wt% concentration were used of nanofluids (NFs) which were silica/water + ethylene glycol (SiO2)/(H2O + EG), and hybrid nanofluids of magnesium oxide + carbon black/water (MgO + CB/H2O) and carbon black + graphene nanoplatelets/water (CB + GNPs/H2O) at flow rates of 0.020, 0.015, and 0.010 kg/s. The experimentation was performed under real climate conditions of Taxila, Pakistan, and solar irradiance and ambient temperature were measured to determine the performance of the CPC in comparison to a simple base fluid which was water. The experimental results revealed that a maximum temperature difference of 8.5°C with an around thermal efficiency of 38.51% was achieved for hybrid pair of MgO + CB at a flow rate of 0.010 kg/s and volumetric concentration of 0.015 wt%. The efficiency variation using NFs (SiO2/EG + H2O) varies from 12.8% to 59.1% from lowest 0.010 kg/s to highest 0.020 kg/s flow rates, and volumetric concentrations (0.010 and 0.015 wt%) of nanoparticles. For similar experimental conditions, efficiency variation for (CB + GNPs) pair varies from 14.2% to 65.6% for aforementioned conditions. Efficiency variation from 15.3% to 66.3% was attained using MgO + CB in the base fluid of water for said flow rates and volumetric concentrations of nanoparticles. In addition, an efficiency enhancement of 24.3%, 30.8%, and 31.5% was observed for SiO2/EG + H2O, CB + GNPs/H2O, and MgO + CB/H2O, respectively, at maximum flow rates and volumetric concentration of nanoparticles as compared to water. Therefore, the usage of hybrid-based NF in the CPC is beneficial in terms of efficiency enhancement, and it will bring young research workers to get deep into this field to bring revolution in the area of solar energy.

A novel study for hybrid pair of multivalued dominated mappings in b-multiplicative metric space with applications

The aim of this paper is to prove some new fixed point results for a pair of multivalued dominated locally contractive mappings in b-multiplicative metric space. Further, fixed point theorems for multigraph-dominated mappings are also established. Some new fixed point results on a closed ball are obtained for a pair of multigraph-dominated mappings endowed with graphic structure in b-multiplicative metric space. An illustrative example is given to show the validity of the hypothesis of our obtained result. Moreover, applications for a coupled system of nonlinear Volterra-type integral equations and functional equations in dynamic programming are presented to show the novelty of our results.

Total Synthesis of Leptochartamides A and B: Two Enantiomeric Pairs of Hydroxybenzyl Dimers from a Deep-Sea Fungus Leptosphaerulina chartarum.

Leptochartamides A and B (±1 and ±2), two pairs of enantiomeric hybrids with the same cyclo-bridged skeleton containing an unusual dioxa-azabicyclo[3.2.1]octane core system, were isolated from the deep-sea-derived fungus Leptosphaerulina chartarum. Their structures were determined by detailed spectroscopic analysis, single-crystal X-ray diffraction, electronic circular dichroism calculations, and the total synthesis. Compounds 2a and 2b showed selective cytotoxicity against Ewings sarcoma cells A673, with IC50 values of 8.98 ± 0.23 and 4.18 ± 0.27 μM, respectively. The colony formation assay of compounds 2a and 2b against A673 cells was completed.

The first case of a successful brood from a double hybrid mixed pair (Dendrocopos syriacus × Dendrocopos major (Picidae))

Hybridization occurs between numerous bird species, with some of them capable of producing backcrosses. However, little information is available concerning mating between pairs of hybrids. In this case study, a mixed pairing is reported between hybrids of Syrian and Great Spotted Woodpeckers, Dendrocopos syriacus and Dendrocopos major, respectively. Mixed phenotypic and genotypic traits were found in the male, the female and their offspring. The possible consequences of hybridization and its effect on the Syrian Woodpecker, which is protected under the Bird Directive of the European Union, are discussed.

GISH Analysis of the Introgression of the B Subgenome Genetic Material of Wild Allotetraploid Species Solanum stoloniferum into Backcrossing Progenies with Potato

Wild relatives of cultivated potato are used in breeding to increase the genetic diversity of Solanum tuberosum (AAAA genome) varieties. Wild Mexican allotetraploid species Solanum stoloniferum (AABB genome) was used in breeding for extreme resistance to viruses and late blight. In this study, genomic in situ hybridization (GISH) was used for visualization of introgression of genetic material of the B subgenome of S. stoloniferum into the genome of backcross hybrids. The fertile hexaploid hybrid had 48 chromosomes of the A genome and 24 chromosomes of the B subgenome. Plants of the BC1 generation were pentaploid having the AAAAB genome constitution and three selected BC2 hybrids were aneuploid, containing one to six chromosomes of the B subgenome and 48 chromosomes of the A genome. The B subgenome of S. stoloniferum was inherited in the backcross generations as single chromosomes and in rare cases as recombinant chromosomes. GISH showed that chromosome pairing in the backcross hybrids was predominantly intragenomic. Most chromosomes of the B subgenome remained as univalents in backcross hybrids. Rare homeologous A/B chromosome pairing was detected in all analyzed hybrids. The obtained data indicate that the B subgenome of S. stoloniferum was able to recombine with the A genome.

Performance of Bt maize event MON810 in controlling maize stem borers Chilo partellus and Busseola fusca in Uganda

Stem borers are major insect pests of maize in Uganda. A study was conducted in 2014–2016 to assess the performance of Bt hybrids expressing Cry1Ab (event MON810) against the two major stem borer species in Uganda – the African stem borer (Busseola fusca) and the spotted stem borer (Chilo partellus) – under artificial infestation. The study comprised 14 non-commercialized hybrids, including seven pairs of Bt and non-Bt hybrids (isolines), three non-Bt commercial hybrids and a conventional stem borer resistant check. All stem borer damage parameters (leaf damage, number of internodes tunneled and tunnel length) were generally significantly lower in Bt hybrids than in their isolines, the conventionally resistant hybrid, and local commercial hybrids. Mean yields were significantly higher by 29.4–80.5% in the Bt hybrids than in the other three categories of non-Bt hybrids. This study demonstrated that Bt maize expressing Cry1Ab protects against leaf damage and can limit entry of stem borers into the stems of maize plants, resulting in higher yield than in the non-transgenic hybrids. Thus, Bt maize has potential to contribute to the overall management package of stem borers in Uganda.

Morphological, cytological, and molecular evidences for natural hybridization between Roegneria stricta and Roegneria turczaninovii (Triticeae: Poaceae).

Some plants with low fertility are morphologically intermediate between Roegneria stricta and Roegneria turczaninovii, and were suspected to be natural hybrids between these species. In this study, karyotype analysis showed that natural hybrids and their putative parents were tetraploids (2n = 4x = 28). Meiotic pairing in natural hybrids is more irregular than its putative parents. Results of genomic in situ hybridization and fluorescence in situ hybridization indicate that natural hybrids contain the same genome as their putative parents. The nuclear gene DNA meiotic recombinase 1 (DMC1) and the chloroplast gene rps16 of natural hybrids and their putative parents were analyzed for evidence of hybridization. The results from molecular data supported by morphology and cytology demonstrated that the plants represent natural hybrids between R. stricta and R. turczaninovii. The study is important for understanding species evolution in the genus since it demonstrates for the first time the existence of populations of natural homoploid hybrids in Roegneria. The study also reports for the first time that the composition of the genomic formula of R. turczaninovii is StY, confirming that the current taxonomic status is correct.

Hybrid pair of multivalued mappings in modular-like metric spaces and applications

<abstract><p>Our aim is to prove some new fixed point theorems for a hybrid pair of multivalued $ \alpha _{\ast } $-dominated mappings involving a generalized $ Q $-contraction in a complete modular-like metric space. Further results involving graphic contractions for a pair of multi-graph dominated mappings have been considered. Applying our obtained results, we resolve a system of nonlinear integral equations.</p></abstract>

Coupled coincidence points for hybrid pair of mappings via mixed monotone property in bipolar metric spaces

In this paper, we establish a coupled coincidence fixed point results for a hybrid pair of single valued and multivalued mappings satisfying generalized contractive conditions, defined on a partially ordered bipolar metric space. Our results unify, generalize and complement several known comparable results from the current literature. An example is given.

Theoretical study on enhancement of thermal conductivity and viscosity with volume fraction for ethylene glycol-based iron nanofluid

Gaining more higher heat transferability in nanofluids is one of the most serious relevant problems for improving efficiency in a variety of technology areas. In this study, the thermophysical properties of ethylene glycol-based (EG) iron nanofluid in comparison to its base fluid are investigated by using Equilibrium Molecular Dynamics (EMD) simulations combined with the hybrid pair potential in a LAMMPS (Large Scale Atomic-Molecular Massively Parallel Simulator) software that incorporates the 12–6 Lennard-Jones (L-J) potential with an Embedded Atom Method (EAM). The simulation findings showed that suspending spherical shaped iron nanoparticles in EG base fluid improves their viscosity, and conductivity (thermal) compare to the base fluid. Heat Current Autocorrelation function (HCACF) shows oscillatory behaviour initially. The amplitude of oscillation decays asymptotically around zero up to 0.75 ps. Thermal conductivity (TC) increases with volume fraction and temperature. Stress Autocorrelation function (SACF) decreases monotonically and viscosity increases with volume fraction but decreases with temperature.

Common Fixed Point Theorem for Hybrid Pair of Mappings in a Generalized $(F,\xi,\eta)$-contraction in weak Partial $b$- Metric Spaces with an Application

In the present paper, we proved a common fixed-point theorem for two-hybrid pair of non-self mappings satisfying a generalized $(F, \xi, \eta) $- contraction condition under joint common limit range property in weak partial $b$- metric spaces. Our result is a generalization of many works available in metric space setting. An example and application to the integral equation are given to support the results proved in this paper.

Correlation between quantitative traits that affect grain yield of maize hybrids

The selection of pairs for hybridization requires knowledge about the correlation of the most important quantitative traits that affect grain yield of maize hybrids. The current study was carried out in the Agricultural Research Center “Donskoy” located in the south of the Rostov region with unstable moisture. The years of study (2018–2020) were arid (HThC 0.32–0.89). The purpose of the current study was to evaluate the correlation between quantitative traits and their influence on grain yield of maize hybrids under arid conditions. The objects of research were 96 interline maize hybrids. The analysis has identified the correlation between grain yield and such quantitative traits as ‘one maize ear weight’ (r = 0.64...0.87), ‘number of grains per one maize ear row’ (r = 0.37...0.75), ‘number of grains per maize ear’ (r = 0.32...0.51), ‘number of maize ears per plant’ (r = 0.41...0.53), ‘grain yield’ (r = 0.45...0.64). The traits ‘1000-grain weight’ and ‘number of grain rows’ had either no or slight effect on the formation of grain yield of maize hybrids (r = -0.12...0.28). There have been established the traits, the high values of which were well-combining in one genotype. The values of the trait ‘one maize ear weight’ raised due to an increase of the trait ‘number of grains per one maize ear row’ (r = 0.27...0.74), ‘number of grains per maize ear’ (r = 0.26...0.55), ‘grain yield’ (r = 0.21...0.52). The trait ‘number of grains per maize ear’ raised with an increase in the values of such constituent components as ‘number of grains per one maize ear row’ (r = 0.70...0.76), ‘number of grain rows per maize ear’ (r = 0.59...0.66), and also with an increase of ‘number of maize ears per plant’ (r = 0.32...0.51) and ‘grain yield’ (r = 0.36...0.38). There have been identified difficulty-combining quantitative traits, when the value of the trait ‘1000-grain weight’ decreased with the increase of the ‘number of grain rows per maize ear’ (r = – 0.18...-0.56), ‘number of grains per a maize ear row’ (r = -0.15...-0.31) and ‘grain yield’ (r = -0.01...-0.36).

Transgressive variability of the main ear grains number in F 2 populations in hybridization of soft winter wheat varieties that differ in early ripening

The studies conducted in the contrastive by their hydrothermal conditions 2019–2020 examined F 2 hybrid populations created by crossing different early ripening varieties of soft winter wheat. Most of F 2 populations used in various crossbreeding schemes of early ripening, middle-early, medium-ripening, and middle-late varieties for both average number of grains in the ear and its maximum manifestation, signifcantly exceeded the original forms and characterized by signifcant formation. The obtained results indicate a signifcant influence of the selected pairs for hybridization and hydrothermal conditions of the year on the formation of the number of grains in F2 populations of soft winter wheat. However, hybrid populations with early ripening varieties as the maternal form are less susceptible to adverse hydrothermal conditions. The research results give ground for defning hybrid populations, which had less than the average number of grains in the ear for F 2 in the most contrastive hydrothermal conditions and were characterized by high rates and frequency of positive transgressions, namely: Myronivska early / B.Ts. semidwarf; Myronivska early / Zolotokosa.; Myronivska early / Chorniava; Kolchuga / Stolychna; Myronivska early / Vdala; Shchedra nyva / Vidrada; Antonivka / Stolychna. The identifed correlations between the degree of phenotypic dominance in F1 and the degree and frequency of positive transgressions indicate an insignifcantly weak direct to inverse relationship between these indicators. At a reliable level, in the years of research, a strong (r = 0.774…0.893) correlation was found with the degree of positive transgressions and the frequency of recombinants. Key words: degree and frequency of transgression, soft winter wheat, maturity groups, parental forms, variability, number of grains of the main ear, population F2, degree of phenotypic dominance.

Sexually dichromatic hybrids between two monochromatic duck species, the Chiloé wigeon and the Philippine duck.

Captive bird hybrids can provide important data on certain traits, such as hybrid viability and fertility. In this paper, we describe four hybrids between the Chiloé wigeon (Anas sibilatrix) and the Philippine duck (Anas luzonica). These two species diverged about 13 million years ago and are found on different continents, making the occurrence of wild hybrids extremely unlikely. Hence, these captive hybrids provide a unique opportunity to learn more about the outcome of hybridization between these highly divergent species. One pair of hybrids mated and produced six unfertilized eggs, suggesting that hybrids between these species are infertile. Morphologically, the hybrids were slightly larger than the parental species, but had intermediate bill lengths. With regard to plumage patterns, the hybrids displayed characteristics of both parental species: Males developed the iridescent green head pattern of the Chiloé wigeon, whereas the females showed the dark crown and eye stripe of the Philippine duck. Interestingly, Chiloé wigeon and Philippine duck are both sexually monochromatic whereas the hybrids showed clear sexual dimorphism. These hybrids can thus lead to novel insights into the genetic and developmental basis of sexual mono‐ and dichromatism in ducks.

Multivalued (g − F − φ) contractions obtaining common fixed points inG-metric spaces

The aim of this paper is to introduce new notions called generalized [Formula: see text] contraction and rational type [Formula: see text] contraction for hybrid maps in complete G-metric spaces. First, using new concept of generalized [Formula: see text] contraction we establish a common fixed point theorem for a hybrid pair of weakly compatible maps. Second, we prove a common fixed point theorem for occasionally coincidentally idempotent mappings satisfying another new concept of rational type [Formula: see text] contraction under common limit range property. Our results generalize and improve several known results of the existing literature. Also, we give an example to indicate the usefulness of our main results.

Localization of 5S rDNA analysis of homologous pairing in tetraploid hybrids of red crucian carp (♀) × common carp (♂)

AbstractInterspecies crossing and allopolyploidization increase the opportunity for generating new breeding resources for fish farming. Allotetraploid hybrid fish (4nAT) were created by crossing red crucian carp (RCC, Carassius auratus red var., ♀) with common carp (CC, Cyprinus carpio L., ♂). However, the genetic pattern of the heterogeneous genomes during gametogenesis in 4nAT is still unclear, which hinders the understanding of the mechanism of generation of new phenotypes during allopolyploidization in fish breeding. In the present study, fluorescence in situ hybridization of 5S rDNA was employed to track homologous pairing, and the characteristics of bivalents were observed using air‐drying preparation technology and electron microscopy. The results showed two strong signals of 5S rDNA localization from the RCC genome, paired in the pachytene stage and metaphase stage of meiosis I cells in 4nAT, suggesting pairing of homologous chromosomes in 4nAT occurred between identical chromosomes. Furthermore, all bivalent pairs possessed one monochiasmate and were neatly arranged in the equatorial plate during meiosis I, which ensured normal separation of homologous chromosomes in 4nAT. This study elucidated the genetic pattern of heterogeneous genomes in 4nAT, providing important evidence for the genetic stability of 4nAT. These findings are of great significance for aquatic breeding.

Computational search of hybrid human/SARS-CoV-2 dsRNA reveals unique viral sequences that diverge from those of other coronavirus strains

The role of the RNAi/Dicer/Ago system in degrading RNA viruses has been elusive in mammals in the past, which has prompted authors to think that interferon (IFN) synthesis is essential in this clade, relegating the RNAi defense strategy against viral infection as an accessory function. However, recent publications highlight the existence of abundant viral small interference and micro RNAs (VsiRNAs and VmiRNAs) in both cell-line and whole organism based experiments, indicating a contribution of these molecules in host responses and/or viral replication. We explore the theoretical possibility that RNAi triggered by SARS-CoV-2 might degrade some host transcripts in the opposite direction, although this hypothesis seems counterintuitive. The SARS-CoV-2 genome was therefore computationally searched for exact intrapairing within the viral RNA and exact hybrid pairing with the human transcriptome over a minimum of 20 bases in length. Minimal segments of 20-base lengths of SARS-CoV-2 RNA were found based on the theoretical matching with existing complementary strands in the human host transcriptome. Few human genes potentially annealing with SARS-CoV-2 RNA, including mitochondrial deubiquitinase USP30, the subunit of ubiquitin protein ligase complex FBXO21 and two long noncoding RNAs, were retrieved. The hypothesis that viral-originated RNAi might mediate degradation of host transcriptome messages was corroborated by published high throughput sequencing of RNA from infected tissues and cultured cells, clinical observation and phylogenetic comparative analysis, indicating a strong specificity of these SARS-CoV-2 hybrid pairing sequences for human genomes.

A unique common fixed point for a family of set-valued mappings

Abstract The main purpose of this paper is to establish some common fixed point theorems for single and set-valued mappings, under strict contractive conditions with no continuity, no completeness, no inclusions and without using neither compactness nor closeness. These theorems improve the results of Fisher [8], Ahmed [1] and [2], and others. Also, common fixed point theorems for two hybrid pairs satisfying a contractive condition of integral type are given improving the results of [3], [4] and [6].

Inheritance of resistance of spring barley to Erysiphe graminis f. sp. hordei in F1 and variability in F2 in the conditions of the Right-Bank Forest-Steppe of Ukraine

The nature of the inheritance of resistance to Erysiphe graminis f. sp. hordei in the crosses of genotypes of spring barley in F1 and transgressive variability in F2 populations are investigated. Inheritance of the trait of resistance to Erysiphe graminis f. sp. hordei in F1, by hybridization of genotypes of spring barley with known genes of resistance to Erysiphe graminis f. sp. hordei in European varieties Eunova (mlo11) and Barke (mlo9), which are located on chromosome 1H, was positively dominated. Inheritance of the F1 trait in Aspen (mlo11) and Adonis (mlo9) cultivars was partially positive. The influence of parental pairs for hybridization on the indicators of the degree of phenotypic dominance, hypothetical and true heterosis was established. Resistance to Erysiphe graminis f. sp. hordei in F1 hybrids was observed heterosis (positive dominance) in fve hybrid combinations (hp = 1.1–1.9 %): Barke/Badoryi, Barke/Sanktrum, Parnas/Rostentsii, Badoryi/ Barke, Eunova/Zvershennia. Hypothetical heterosis (Ht) in F1 was observed in 13 of 16 hybrids (from +2.8 % to +97.6 %). A positive value of true heterosis (Htb) in F1 was observed in 15 hybrids out of 16 (from +1.9 % to +98.8 %). Inheritance of the trait of resistance to Erysiphe graminis f. sp. hordei in all studied hybrids was influenced by the cytoplasm of the mother plant, except for the hybrid Eunova / Triangel, where the influence of the nuclear apparatus was detected. Hybrids were found in the F 2 population with high resistance to Erysiphe graminis f. sp. hordei, which exceeded the parental components, which indicates a signifcant shaping process and the possibility of selection on the basis of the studied trait. The degree of positive transgression ranged from 16.0 % to 73.0 % in hybrids Aspen / Skarlet, Adonis / Vanja, Barke / Badoryi, Barke / Sanktrum, Eunova / Triangel and Eunova / Zvershennia, where highly resistant varieties were used for the mother form. The combinations in which the frequency of transgression was observed in more than 50.0 % of plants are hybrids: Eunova / Triangel, Barke / Sanktrum, Eunova / Zvershennia, Parnas / Rostentsii and Barke / Badoryi. Key words: spring barley, resistance, Erysiphe graminis f. sp. hordei, combinations of crossing, inheritance, F1, true and hypothetical heterosis, degree of phenotypic dominance, F 2, degree and frequency of transgressions.