Identification of Candidate Genes for Root Traits Using Genotype–Phenotype Association Analysis of Near-Isogenic Lines in Hexaploid Wheat (Triticum aestivum L.)

Global wheat (Triticum aestivum L.) production is constrained by different biotic and abiotic stresses, which are increasing with climate change. An improved root system is essential for adaptability and sustainable wheat production. In this study, 10 pairs of near-isogenic lines (NILs)—targeting four genomic regions (GRs) on chromosome arms 4BS, 4BL, 4AS, and 7AL of hexaploid wheat—were used to phenotype root traits in a semi-hydroponic system. Seven of the 10 NIL pairs significantly differed between their isolines for 11 root traits. The NIL pairs targeting qDSI.4B.1 GR varied the most, followed by the NIL pair targeting qDT.4A.1 and QHtscc.ksu-7A GRs. For pairs 5–7 targeting qDT.4A.1 GR, pair 6 significantly differed in the most root traits. Of the 4 NIL pairs targeting qDSI.4B.1 GR, pairs 2 and 4 significantly differed in 3 and 4 root traits, respectively. Pairs 9 and 10 targeting QHtscc.ksu-7A GR significantly differed in 1 and 4 root traits, respectively. Using the wheat 90K Illumina iSelect array, we identified 15 putative candidate genes associated with different root traits in the contrasting isolines, in which two UDP-glycosyltransferase (UGT)-encoding genes, TraesCS4A02G185300 and TraesCS4A02G442700, and a leucine-rich repeat receptor-like protein kinase (LRR-RLK)-encoding gene, TraesCS4A02G330900, also showed important functions for root trait control in other crops. This study characterized, for the first time, that these GRs control root traits in wheat, and identified candidate genes, although the candidate genes will need further confirmation and validation for marker-assisted wheat breeding.     

Temperature dependent photoluminescence investigation of the effect of growth pause induced ripening in InAs/GaAs quantum dot heterostructures

Self-assembled InAs/GaAs quantum dot (QD) heterostructures grown by solid state molecular beam epitaxy (MBE) were subjected to growth ripening pause of comparatively shorter durations (0–50 s) at the growth temperature (520 °C). The islands are found to increase in size with the growth pause and correspondingly their density decreases. Though the photoluminescence spectra of the islands subjected to growth pause is found to follow conventional QD systems, a contradiction is noticed in the calculated values of the activation energy of the dots. We ascribed this contradiction due to the poor crystalline quality of the ripened QDs as a result of desorption and sublimation of indium during the pause at high growth temperature.     

Analysis of Slide Gate Mounting Bolt Failure in Steel Ladle Due to Fatigue

The mounting bolt failed during slide gate operation of a steel ladle was investigated. Metallurgical analysis confirms the bolt as IS 1367 10.9 grade high-tensile 42CrMo₄ steel. On comparative study with a good un-fractured sample, a striation of fine banded ferrite in pearlite matrix was revealed in failed bolt under optical microscopy. The bolts failed due to fatigue and crack initiated from the surface of machined bolt threads. Comparatively lower hardness, low UTS associated with lower %Cr and %Mo content found to aggravate premature failure of bolts during ladle operation. Microstructure of un-fractured sample found with tempered bainite phase. The fatigue failure of bolts occurred due to repetitive nature of shear force development during steel pouring through slide gate system. Preventive measures to reduce fatigue failure of the mounting bolts are proposed.     

Thermal stability of the peak emission wavelength in multilayer InAs/GaAs QDs capped with a combination capping of InAlGaAs and GaAs

The effect of rapid thermal annealing (RTA) on the optical properties of a 10 layer stacked InAs/GaAs quantum dot (QD) heterostructure where the QDs are overgrown with a combination of quaternary InAlGaAs and GaAs capping have been investigated. TEM micrographs showed that the shape of the QDs is preserved for annealing temperatures up to 800 degrees C. The peak emission wavelength of the investigated heterostructures remains stable on annealing at temperatures upto 750 degrees C, which is unusual in QD samples. This phenomenon is attributed due to the suppression of the strain-enhanced intermixing in such structures. One of the reasons behind such suppression is the strain driven phase separation of Indium from the overgrown quaternary alloy, which maintains an In rich region across the QD periphery thereby checking the out-diffusion of Indium from the dots. The overlapping vertical strain from the under lying dot layers in the QD stack also maintains a strain relaxed state at the QD base, thereby preventing the material mixing at the base of the pyramidal QDs. This stability of wavelength is of paramount importance in optoelectronic devices where the design is based on the emission wavelength of the active region.     

Ultrabithorax regulates genes at several levels of the wing-patterning hierarchy to shape the development of the Drosophila haltere

Arthropods and vertebrates are constructed of many serially homologous structures whose individual patterns are regulated by Hox genes. The Hox-regulated target genes and developmental pathways that determine the morphological differences between any homologous structures are not known. The differentiation of the Drosophila haltere from the wing through the action of the Ultrabithorax (Ubx) gene is a classic example of Hox regulation of serial homology, although no Ubx-regulated genes in the haltere have been identified previously. Here, we show that Ubx represses the expression of the Wingless (Wg) signaling protein and a subset of Wg- and Decapentaplegic-activated genes such as spalt-related, vestigial, Serum Response Factor, and achaete-scute, whose products regulate morphological features that differ between the wing and haltere. In addition, we found that some genes in the same developmental pathway are independently regulated by Ubx. Our results suggest that Ubx, and Hox genes in general, independently and selectively regulate genes that act at many levels of regulatory hierarchies to shape the differential development of serially homologous structures.     

Stability enhancement of wind energy integrated hybrid system with the help of static synchronous compensator and symbiosis organisms search algorithm

Conventional proportional integral derivative (PID) controllers are being used in the industries for control purposes. It is very simple in design and low in cost but it has less capability to minimize the low frequency noises of the systems. Therefore, in this study, a low pass filter has been introduced with the derivative input of the PID controller to minimize the noises and to improve the transient stability of the system. This paper focuses upon the stability improvement of a wind-diesel hybrid power system model (HPSM) using a static synchronous compensator (STATCOM) along with a secondary PID controller with derivative filter (PIDF). Under any load disturbances, the reactive power mismatch occurs in the HPSM that affects the system transient stability. STATCOM with PIDF controller is used to provide reactive power support and to improve stability of the HPSM. The controller parameters are also optimized by using soft computing technique for performance improvement. This paper proposes the effectiveness of symbiosis organisms search algorithm for optimization purpose. Binary coded genetic algorithm and gravitational search algorithm are used for the sake of comparison.     

Thieno[3,2‐b]thiophene‐diketopyrrolopyrrole Containing Polymers for Inverted Solar Cells Devices with High Short Circuit Currents

The synthesis and characterization four diketopyrrolopyrrole containing conjugated polymers for use in organic photovoltaics is presented. Excellent energy level control is demonstrated through heteroatomic substitution whilst maintaining similar solid state properties as shown by X‐ray diffraction and atomic force microscopy. Inverted solar cells were fabricated with the best devices having short circuit currents exceeding 16 mA cm^?2 and efficiencies of over 5% irrespective of whether [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₀BM) or [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₀BM) is used. Transient absorption spectroscopy on the bulk heterojunction blends shows efficient charge photo‐generation, with the variations in short circuit current correlated to the energetic offset between polymer and fullerene.     

Assessment of arsenic exposure from groundwater and rice in Bengal Delta Region, West Bengal, India

Arsenic (As) induced identifiable health outcomes are now spreading across Indian subcontinent with continuous discovery of high As concentrations in groundwater. This study deals with groundwater hydrochemistry vis-à-vis As exposure assessment among rural population in Chakdaha block, West Bengal, India. The water quality survey reveals that 96% of the tubewells exceed WHO guideline value (10 μg/L of As). The groundwaters are generally anoxic (−283 to −22 mV) with circum-neutral pH (6.3 to 7.8). The hydrochemistry is dominated by HCO₃⁻ (208 to 440 mg/L), Ca²⁺ (79 to 178 mg/L) and Mg²⁺ (17 to 45 mg/L) ions along with high concentrations of As_T (As total, below detection limit to 0.29 mg/L), Fe_T (Fe total, 1.2 to 16 mg/L), and Fe(II) (0.74 to 16 mg/L). The result demonstrates that Fe(II)-Fe(III) cycling is the dominant process for the release of As from aquifer sediments to groundwater (and vice versa), which is mainly controlled by the local biogeochemical conditions. The exposure scenario reveals that the consumption of groundwater and rice are the major pathways of As accumulation in human body, which is explained by the dietary habit of the surveyed population. Finally, regular awareness campaign is essential as part of the management and prevention of health outcomes.