160 research outputs found
Performance and Stability of Pearl Millet Varieties for Grain Yield and Micronutrients in Arid and Semi-Arid Regions of India
Pearl millet [Pennisetum glaucum (L.) R. Br.] is grown under both arid and semi-arid
conditions in India, where other cereals are hard to grow. Pearl millet cultivars, hybrids,
and OPVs (open pollinated varieties) are tested and released by the All India Coordinated
Research Project on Pearl Millet (AICRP-PM) across three zones (A1, A, and B) that are
classified based on rainfall pattern. Except in locations with extreme weather conditions,
hybrids dominate pearl millet growing areas, which can be attributed to hybrid vigor and
the active role of the private sector. The importance of OPVs cannot be ruled out, owing
to wider adaptation, lower input cost, and timely seed availability to subsidiary farmers
cultivating this crop. This study was conducted to scrutinize the presently used test
locations for evaluation of pearl millet OPVs across India, identify the best OPVs across
locations, and determine the variation in grain Fe and Zn contents across locations in
these regions. Six varieties were evaluated across 20 locations in A1 and A (pooled as
A) and B zones along with three common checks and additional three zonal adapted
checks in the respective zones during the 2019 rainy season. Recorded data on yield and
quality traits were analyzed using genotype main effects and genotype × environment interaction biplot method. The genotype × environment (G × E) interaction was found to
be highly significant for all the grain yield and agronomic traits and for both micronutrients
(iron and zinc). However, genotypic effect (G) was four (productive tillers) to 49 (grain
Fe content) times that of G × E interaction effect for various traits across zones that
show the flexibility of OPVs. Ananthapuramu is the ideal test site for selecting pearl millet
cultivars effectively for adaptation across India, while Ananthapuramu, Perumallapalle,
and Gurugram can also be used as initial testing locations. OPVs MP 599 and MP
600 are identified as ideal genotypes, because they showed higher grain and fodder
yields and stability compared with other cultivars. Iron and zinc concentration showed
highly significant positive correlation (across environment = 0.83; p < 0.01), indicating
possibility of simultaneous effective selection for both traits. Three common checks were
found to be significantly low yielders than the test entries or zonal checks in individual
zones and across India, indicating the potential of genetic improvement through OPVs
Molecular Cloning and Copy Number Variation of a Ferritin Subunit (Fth1) and Its Association with Growth in Freshwater Pearl Mussel Hyriopsis cumingii
Iron is one of the most important minor elements in the shells of bivalves. This study was designed to investigate the involvement of ferritin, the principal protein for iron storage, in shell growth. A novel ferritin subunit (Fth1) cDNA from the freshwater pearl mussel (Hyriopsis cumingii) was isolated and characterized. The complete cDNA contained 822 bp, with an open reading frame (ORF) of 525 bp, a 153 bp 5′ untranslated region (UTR) and a 144 bp 3′ UTR. The complete genomic DNA was 4125 bp, containing four exons and three introns. The ORF encoded a protein of 174 amino acids without a signal sequence. The deduced ferritin contained a highly conserved motif for the ferroxidase center comprising seven residues of a typical vertebrate heavy-chain ferritin. It contained one conserved iron associated residue (Try27) and iron-binding region signature 1 residues. The mRNA contained a 27 bp iron-responsive element with a typical stem-loop structure in the 5′-UTR position. Copy number variants (CNVs) of Fth1 in two populations (PY and JH) were detected using quantitative real-time PCR. Associations between CNVs and growth were also analyzed. The results showed that the copy number of the ferritin gene of in the diploid genome ranged from two to 12 in PY, and from two to six in JH. The copy number variation in PY was higher than that in JH. In terms of shell length, mussels with four copies of the ferritin gene grew faster than those with three copies (P<0.05), suggesting that CNVs in the ferritin gene are associated with growth in shell length and might be a useful molecular marker in selective breeding of H. cumingii
Characterization of Granulations of Calcium and Apatite in Serum as Pleomorphic Mineralo-Protein Complexes and as Precursors of Putative Nanobacteria
Calcium and apatite granulations are demonstrated here to form in both human and
fetal bovine serum in response to the simple addition of either calcium or
phosphate, or a combination of both. These granulations are shown to represent
precipitating complexes of protein and hydroxyapatite (HAP) that display marked
pleomorphism, appearing as round, laminated particles, spindles, and films.
These same complexes can be found in normal untreated serum, albeit at much
lower amounts, and appear to result from the progressive binding of serum
proteins with apatite until reaching saturation, upon which the mineralo-protein
complexes precipitate. Chemically and morphologically, these complexes are
virtually identical to the so-called nanobacteria (NB) implicated in numerous
diseases and considered unusual for their small size, pleomorphism, and the
presence of HAP. Like NB, serum granulations can seed particles upon transfer to
serum-free medium, and their main protein constituents include albumin,
complement components 3 and 4A, fetuin-A, and apolipoproteins A1 and B100, as
well as other calcium and apatite binding proteins found in the serum. However,
these serum mineralo-protein complexes are formed from the direct chemical
binding of inorganic and organic phases, bypassing the need for any biological
processes, including the long cultivation in cell culture conditions deemed
necessary for the demonstration of NB. Thus, these serum granulations may result
from physiologically inherent processes that become amplified with calcium
phosphate loading or when subjected to culturing in medium. They may be viewed
as simple mineralo-protein complexes formed from the deployment of
calcification-inhibitory pathways used by the body to cope with excess calcium
phosphate so as to prevent unwarranted calcification. Rather than representing
novel pathophysiological mechanisms or exotic lifeforms, these results indicate
that the entities described earlier as NB most likely originate from calcium and
apatite binding factors in the serum, presumably calcification inhibitors, that
upon saturation, form seeds for HAP deposition and growth. These calcium
granulations are similar to those found in organisms throughout nature and may
represent the products of more general calcium regulation pathways involved in
the control of calcium storage, retrieval, tissue deposition, and disposal
Borane-Catalyzed Ring-Opening and Ring-Closing Cascades of Furans Leading to Silicon-Functionalized Synthetic Intermediates
The conversion of renewable biomass resources to synthetically valuable chemicals is highly
desirable, but remains a formidable challenge in regards to the substrate scope and reaction
conditions. Here we present the development of tris(pentafluorophenyl)borane–catalysed
conversion of furans via ring-opening and closing cascade processes to afford siliconfunctionalized
synthetic chemicals under transition metal-free conditions. The furan
ring-opening with hydrosilanes is highly efficient (TON up to 2,000) and atom-economical
without forming any byproduct to give rise to a-silyloxy-(Z)-alkenyl silanes. Additional
equivalents of silane smoothly induce a subsequent B(C6F5)3-catalysed cyclization of initially
formed olefinic silane compounds to produce anti-(2-alkyl)cyclopropyl silanes, another
versatile synthon being potentially applicable in the synthesis of natural products and
pharmacophores.
(c) The Author(s) 201611sciescopu
Analog device and circuit performance degradation under substrate bias enhanced hot carrier stress
In this paper, we investigate the influence of forward and reverse body bias stress on the hot carrier induced degradation of MOS analog performance parameters. The underlying physical mechanisms are identified with the help of experimental results, TCAD and Monte-Carlo simulations. We show that under for-ward body bias stress conditions, the auger recombination enhanced hot carrier injection (HCI) degrades the device and circuit performance considerably. Degradation in various analog circuits' performance is quantified by considering the individual transistors under different stress conditions
Deep sub-micron device and analog circuit parameter sensitivity to process variations with halo doping and its effect on circult linearity
Single halo (SH) and double halo (DH) metal oxide semiconductor field effect transistors (MOSFETs) have been reported to exhibit excellent short channel performance in the sub 100 nm regime. In this work, the effect of process variations such as gate oxide thickness, implantation parameters, channel length and temperature are systematically investigated on the device and analog circuit performance for all these technologies. Our simulation results on differential amplifiers and current mirrors show that, for an identical Vt mismatch in conventional (CON), DH, and SH devices, SH MOSFETs show a lower variation in the circuit parameters. It is found that, for a specified circuit parameter variation, almost a 25% higher Vt mismatch is tolerable with SH technologies as compared to the CON technologies. We also report in this work that, better saturation characteristics observed with SH devices improve the linearity of amplifiers when compared with the CON and DH devices, biased at identical voltage gains. However, one needs to account for the increased body bias induced non-linearity with SH technologies as demonstrated using circuit simulations for source follower and simple sample and hold circuits
Analog circuit performance issues with aggressively scaled gate oxide CMOS technologies
MOS transistors with sub 100 nm channel lengths need a gate oxide thickness in the range of 1-2 nm to combat the short channel effects. However at these gate dielectric thicknesses, the gate current is no longer negligible. In this paper, we report the device analog behavior with extremely scaled oxides for integrating mixed signal circuits using the scaled digital CMOS technologies. We show the performance of common source amplifiers and current mirror circuits with these technologies. Our results also show that though thin oxides result in good voltage gains of amplifier circuits, the increased gate leakage degrades the performance of current mirror circuits. We also analyze the performance of different classes of current mirror circuits in the presence of gate leakage and provide broad guidelines for analog circuit design in the presence of gate leakage.© IEE
Forward body-biased single halo MOS devices for low voltage analog circuits
Forward body bias has been shown to be an effective way to improve the digital performance of CMOS circuits. However, as the technologies scale into the sub 100 nm regime, body bias sensitivity degrades, making the application of body bias less attractive for scaled CMOS technologies. In this work, we show for the first time that, Single Halo (SH) MOSFETS exhibit superior body bias sensitivity in the sub 100 nm regime compared to conventional technologies, which can be utilized for improving the performance of forward body-biased MOS devices such as dynamic threshold (DTMOS) and body-driven (BDMOS) transistors for low-voltage (LV) analog designs with the scaled technologies. Our result show that SH doping in these devices results in more than 50 % improvement of intrinsic gain and about a factor of two improvement in transconductance for DTMOS and BDMOS devices respectively, compared to their conventional counterparts.© IEE
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