Sr-Nd isotope geochemistry of the early Precambrian sub-alkaline mafic igneous rocks from the southern Bastar craton, Central India

Sr–Nd isotope data are reported for the early Precambrian sub-alkaline mafic igneous rocks of the southern Bastar craton, central India. These mafic rocks are mostly dykes but there are a few volcanic exposures. Field relationships together with the petrological and geochemical characteristics of these mafic dykes divide them into two groups; Meso-Neoarchaean sub-alkaline mafic dykes (BD1) and Paleoproterozoic (1.88 Ga) sub-alkaline mafic dykes (BD2). The mafic volcanics are Neoarchaean in age and have very close geochemical relationships with the BD1 type. The two groups have distinctly different concentrations of high-field strength (HFSE) and rare earth elements (REE). The BD2 dykes have higher concentrations of HFSE and REE than the BD1 dykes and associated volcanics and both groups have very distinctive petrogenetic histories. These rocks display a limited range of initial 143Nd/144Nd but a wide range of apparent initial 87Sr/86Sr. Initial 143Nd/144Nd values in the BD1 dykes and associated volcanics vary between 0.509149 and 0.509466 and in the BD2 dykes the variation is between 0.510303 and 0.510511. All samples have positive εNd values the BD1 dykes and associated volcanics have εNd values between +0.3 and +6.5 and the BD2 dykes between +1.9 to +6.0. Trace element and Nd isotope data do not suggest severe crustal contamination during the emplacement of the studied rocks. The positive εNd values suggest their derivation from a depleted mantle source. Overlapping positive εNd values suggest that a similar mantle source tapped by variable melt fractions at different times was responsible for the genesis of BD1 (and associated volcanics) and BD2 mafic dykes. The Rb–Sr system is susceptible to alteration and resetting during post-magmatic alteration and metamorphism. Many of the samples studied have anomalous apparent initial 87Sr/86Sr suggesting post-magmatic changes of the Rb–Sr system which severely restricts the use of Rb–Sr for petrogenetic interpretation

Molecular characterization of the HIV-1 gag nucleocapsid gene associated with vertical transmission

BACKGROUND: The human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) plays a pivotal role in the viral lifecycle: including encapsulating the viral genome, aiding in strand transfer during reverse transcription, and packaging two copies of the viral genome into progeny virions. Another gag gene product, p6, plays an integral role in successful viral budding from the plasma membrane and inclusion of the accessory protein Vpr within newly budding virions. In this study, we have characterized the gag NC and p6 genes from six mother-infant pairs following vertical transmission by performing phylogenetic analysis and by analyzing the degree of genetic diversity, evolutionary dynamics, and conservation of functional domains. RESULTS: Phylogenetic analysis of 168 gag NC and p6 genes sequences revealed six separate subtrees that corresponded to each mother-infant pair, suggesting that epidemiologically linked individuals were closer to each other than epidemiologically unlinked individuals. A high frequency (92.8%) of intact open reading frames of NC and p6 with patient and pair specific sequence motifs were conserved in mother-infant pairs' sequences. Nucleotide and amino acid distances showed a lower degree of viral heterogeneity, and a low degree of estimates of genetic diversity was also found in NC and p6 sequences. The NC and p6 sequences from both mothers and infants were found to be under positive selection pressure. The two important functional motifs within NC, the zinc-finger motifs, were highly conserved in most of the sequences, as were the gag p6 Vpr binding, AIP1 and late binding domains. Several CTL recognition epitopes identified within the NC and p6 genes were found to be mostly conserved in 6 mother-infant pairs' sequences. CONCLUSION: These data suggest that the gag NC and p6 open reading frames and functional domains were conserved in mother-infant pairs' sequences following vertical transmission, which confirms the critical role of these gene products in the viral lifecycle

Characterization of HIV-1 envelope gp41 genetic diversity and functional domains following perinatal transmission

BACKGROUND: HIV-1 envelope gp41 is a transmembrane protein that promotes fusion of the virus with the plasma membrane of the host cells required for virus entry. In addition, gp41 is an important target for the immune response and development of antiviral and vaccine strategies, especially when targeting the highly variable envelope gp120 has not met with resounding success. Mutations in gp41 may affect HIV-1 entry, replication, pathogenesis, and transmission. We, therefore, characterized the molecular properties of gp41, including genetic diversity, functional motifs, and evolutionary dynamics from five mother-infant pairs following perinatal transmission. RESULTS: The gp41 open reading frame (ORF) was maintained with a frequency of 84.17% in five mother-infant pairs' sequences following perinatal transmission. There was a low degree of viral heterogeneity and estimates of genetic diversity in gp41 sequences. Both mother and infant gp41 sequences were under positive selection pressure, as determined by ratios of non-synonymous to synonymous substitutions. Phylogenetic analysis of 157 mother-infant gp41 sequences revealed distinct clusters for each mother-infant pair, suggesting that the epidemiologically linked mother-infant pairs were evolutionarily closer to each other as compared with epidemiologically unlinked sequences. The functional domains of gp41, including fusion peptide, heptad repeats, glycosylation sites and lentiviral lytic peptides were mostly conserved in gp41 sequences analyzed in this study. The CTL recognition epitopes and motifs recognized by fusion inhibitors were also conserved in the five mother-infant pairs. CONCLUSION: The maintenance of an intact envelope gp41 ORF with conserved functional domains and a low degree of genetic variability as well as positive selection pressure for adaptive evolution following perinatal transmission is consistent with an indispensable role of envelope gp41 in HIV-1 replication and pathogenesis

Rheological Behaviour of Ceramic Inks for Direct Ceramic Inkjet Printing

In this paper, studies were made on the preparation of ceramic inks with: (i) alumina powderin ethyl alcohol and (ii) zirconia powder in ethyl alcohol at different volume fractions of ceramic.Different amounts (0.75-3.00 vol %) of an organic dispersant (oleic acid) were added to ceramicink containing 5 per cent of ceramic by volume in ethyl alcohol. The viscosities of the suspensionswere determined with Brookefield viscometer (model: DV-E), which is suitable for measuringthe viscosities of suspensions accurately. These inks were deposited on a substrate to see theirspread. The sediment packing densities ( m) of the resulting suspensions were calculated usingtheoretical models which can be related to the density that can be achieved in the final product.The highest sediment packing density was arrived at low viscosity values of the ink and occurredwhen 1 per cent of dispersant by volume was used for 5 per cent alumina content. For 5 percent zirconia content, 2 per cent of dispersant by volume gave a similar result. Experimentswere also conducted to find the value of m for different solid loadings (5-25 vol %) of ceramicwith 1 per cent dispersant. It was observed that the sediment packing density and the apparentviscosities were increasing when solid loading concentrations were increased for both aluminaand zirconia-based inks. The optimum value of m and viscosity have been determined from thisstudy. The results of this preliminary study will be useful for further investigations on therheological behaviour of ceramic inks for direct ceramic inkjet printing

Mean-offset classifier based on Wi-Fi indoor positioning system

A mean-offset classification technique was identified. It was found that the meanoffset classifier provides stability under dynamic indoor conditions and provides consistent results when training and test data combinations are swept from 10 – 95%. In this paper the meanoffset classifier is compared to the K-Nearest Neighbors (KNN) and Naïve Bayesian (NB) classifiers, with a view of developing an adaptable and computationally efficient indoor localization model using machine learning principles. It was seen that the mean-offset classifier improved results considerably and achieved an accuracy of 0.85 m and 1.15 m under line-of-sight (LOS) and non-line-of-sight (NLOS) conditions in residential areas.http://ceur-ws.orgam2020Electrical, Electronic and Computer Engineerin

Design of Organic Ternary Blends and Small-Molecule Bulk Heterojunctions: Photophysical Considerations

We explored relationships between photophysical processes and solar cell characteristics in solution-processable bulk heterojunctions (BHJs), in particular: (1) polymer donor:fullerene acceptor:small-molecule (SM) nonfullerene acceptor, (2) polymer donor:SM donor:SM nonfullerene acceptor, and (3) SM donor:SM nonfullerene or fullerene acceptor. Addition of a nonfullerene SM acceptor to “efficient” polymer:fullerene BHJs led to a reduction in power conversion efficiency (PCE), mostly due to decreased charge photogeneration efficiency and increased disorder. By contrast, addition of an SM donor to “inefficient” polymer:SM nonfullerene acceptor BHJs led to a factor of two to three improvement in the PCE, due to improved charge photogeneration efficiency and transport. In most blends, exciplex formation was observed and correlated with a reduced short-circuit current (Jsc) without negatively impacting the open-circuit voltage (Voc). A factor of ∼5 higher PCE was observed in SM donor:fullerene acceptor BHJs as compared to SMBHJs with the same SM donor but nonfullerene acceptor, due to enhanced charge carrier photogeneration in the blend with fullerene. Our study revealed that the HOMO and LUMO energies of molecules comprising a blend are not reliable parameters for predicting Voc of the blend, and an understanding of the photophysics is necessary for interpreting solar cell characteristics and improving the molecular design of BHJs

Epstein-Barr Virus BART9 miRNA Modulates LMP1 Levels and Affects Growth Rate of Nasal NK T Cell Lymphomas

Nasal NK/T cell lymphomas (NKTCL) are a subset of aggressive Epstein-Barr virus (EBV)-associated non-Hodgkin's lymphomas. The role of EBV in pathogenesis of NKTCL is not clear. Intriguingly, EBV encodes more than 40 microRNAs (miRNA) that are differentially expressed and largely conserved in lymphocryptoviruses. While miRNAs play a critical role in the pathogenesis of cancer, especially lymphomas, the expression and function of EBV transcribed miRNAs in NKTCL are not known. To examine the role of EBV miRNAs in NKTCL, we used microarray profiling and qRT-PCR to identify and validate expression of viral miRNAs in SNK6 and SNT16 cells, which are two independently derived NKTCL cell lines that maintain the type II EBV latency program. All EBV BART miRNAs except BHRF-derived miRNAs were expressed and some of these miRNAs are expressed at higher levels than in nasopharyngeal carcinomas. Modulating the expression of BART9 with antisense RNAs consistently reduced SNK6 and SNT16 proliferation, while antisense RNAs to BARTs-7 and -17-5p affected proliferation only in SNK6 cells. Furthermore, the EBV LMP-1 oncoprotein and transcript levels were repressed when an inhibitor of BART9 miRNA was transfected into SNK6 cells, and overexpression of BART9 miRNA increased LMP-1 protein and mRNA expression. Our data indicate that BART9 is involved in NKTCL proliferation, and one of its mechanisms of action appears to be regulating LMP-1 levels. Our findings may have direct application for improving NKTCL diagnosis and for developing possible novel treatment approaches for this tumor, for which current chemotherapeutic drugs have limited effectiveness

An agent based model for assessing transmission dynamics and health systems burden for COVID-19

Coronavirus disease of 2019 (COVID-19) pandemic has caused over 230 million infections with more than 4 million deaths worldwide. Researches have been using various mathematical and simulation techniques to estimate the future trends of the pandemic to help the policymakers and healthcare fraternity. Agent-based models (ABM) could provide accurate projections than the compartmental models that have been largely used. The present study involves a simulation of ABM using a synthetic population from India to analyze the effects of interventions on the spread of the disease. A disease model with various states representing the possible progression of the disease was developed and simulated using AnyLogic. The results indicated that imposing stricter non-pharmaceutical interventions (NPI) lowered the peak values of infections, the proportion of critical patients, and the deceased. Stricter interventions offer a larger time window for the healthcare fraternity to enhance preparedness. The findings of this research could act as a start-point to understand the benefits of ABM-based models for projecting infectious diseases and analyzing the effects of NPI imposed

Performance of TiO2 nanoparticles synthesized by microwave and solvothermal methods as photoanode in dye-sensitized solar cells (DSSC)

In this work, a direct comparison of the properties of the TiO2 nanoparticles prepared by microwave and solvothermal methods were carried out and its performance as photoanode in dye-sensitized solar cells (DSSC) was analyzed. Though previously some works exist on the preparation of TiO2 nanoparticles by solvothermal or microwave methods, they could not be compared directly as the experiment conditions such as choice of solvent, precursors and reaction temperatures were not virtually same. Herein, TiO2 nanoparticles were synthesized by microwave and solvothermal methods using the same initial precursors and properties of the prepared nanoparticles were compared. From the X-ray diffraction pattern and Raman analysis, the prepared nanoparticles in both the cases were found to be of anatase phase. Optical properties and its carrier lifetime were studied using UV-Vis absorption, photoluminescence (PL) analysis and PL lifetime studies, respectively. Further, its morphology analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM) images, and SAED (selected area electron diffraction) patterns reveals the polycrystalline nature of the prepared nanoparticles. The surface area and the pore size distribution were studied using BET (Brunauer-Emmett-Teller) and BJH (Barrett-Joyner-Halenda) analysis, which revealed its mesoporous nature and uniform pore distribution. The chemical states of the prepared nanoparticles were further characterized using X-ray photoelectron spectroscopy. The DSSC was fabricated using the prepared TiO2 nanoparticles as photoanodes. Further, the power conversion efficiency and the electron transport properties were analyzed.Indo-Norwegian Collaborative Project INCP UTFORS

Limited redundancy in genes regulated by Cyclin T2 and Cyclin T1

<p>Abstract</p> <p>Background</p> <p>The elongation phase, like other steps of transcription by RNA Polymerase II, is subject to regulation. The positive transcription elongation factor b (P-TEFb) complex allows for the transition of mRNA synthesis to the productive elongation phase. P-TEFb contains Cdk9 (Cyclin-dependent kinase 9) as its catalytic subunit and is regulated by its Cyclin partners, Cyclin T1 and Cyclin T2. The HIV-1 Tat transactivator protein enhances viral gene expression by exclusively recruiting the Cdk9-Cyclin T1 P-TEFb complex to a RNA element in nascent viral transcripts called TAR. The expression patterns of Cyclin T1 and Cyclin T2 in primary monocytes and CD4⁺T cells suggests that Cyclin T2 may be generally involved in expression of constitutively expressed genes in quiescent cells, while Cyclin T1 may be involved in expression of genes up-regulated during macrophage differentiation, T cell activation, and conditions of increased metabolic activity To investigate this issue, we wished to identify the sets of genes whose levels are regulated by either Cyclin T2 or Cyclin T1.</p> <p>Findings</p> <p>We used shRNA lentiviral vectors to stably deplete either Cyclin T2 or Cyclin T1 in HeLa cells. Total RNA extracted from these cells was subjected to cDNA microarray analysis. We found that 292 genes were down- regulated by depletion of Cyclin T2 and 631 genes were down-regulated by depletion of Cyclin T1 compared to cells transduced with a control lentivirus. Expression of 100 genes was commonly reduced in either knockdown. Additionally, 111 and 287 genes were up-regulated when either Cyclin T2 or Cyclin T1 was depleted, respectively, with 45 genes in common.</p> <p>Conclusions</p> <p>These results suggest that there is limited redundancy in genes regulated by Cyclin T1 or Cyclin T2.</p