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Emplacement ages of Paleoproterozoic mafic dyke swarms in eastern Dharwar craton, India: Implications for paleoreconstructions and support for a ∼30° change in dyke trends from south to north
(Elsevier B.V., 2019) Ulf Söderlund; Wouter Bleeker; Kursad Demirer; Rajesh K. Srivastava; Michael Hamilton; Mimmi Nilsson; Lauri J. Pesonen; Amiya K. Samal; Mudlappa Jayananda; Richard E. Ernst; Madabhooshi Srinivas
Large igneous provinces (LIPs) and especially their dyke swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke swarms with emplacement ages within the 2.37–1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight swarms with their currently recommended names:NE–SW to ESE–WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm.N–S to NNE–SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm.N–S to NNW–SSE trending ca. 2.22 Ga Kandlamadugu swarm.NW–SE to WNW–ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm.NW–SE to WNW–ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm.N–S, NW–SE, and ENE–WSW trending ca. 2.08 Ga Devarabanda swarm.E–W trending 1.88–1.89 Ga Hampi swarm.NW–SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features. © 2018 Elsevier B.V.
Ocular manifestations and human immunodeficiency virus retinopathy in patients with acquired immunodeficiency syndrome in North India
(2006) V. Satya Suresh Attili; Vijay P. Singh; A.V. Bhaskar Reddy; Datla V. Varma; Madhukar Rai; Kumar A. Gulati; Shyam Sundar
Aim: To evaluate the spectrum of eye diseases in patients with human immunodeficiency virus, with special reference to human immunodeficiency virus retinopathy and its risk factors. Methods: All patient with human immunodeficiency virus attending the Infectious Disease Clinic at Sir Sunderlal Hospital, Institute of Medical Sciences, Banaras Hindu University, India, between January 2001 and December 2003 were enrolled. All patients underwent a thorough eye examination. Patients with acquired immunodeficiency syndrome retinopathy were analysed separately for predisposing factors. The risk factors analysed were positive C-reactive protein, low CD4 levels, associated central nervous system infections, and other eye diseases. Statistical analysis was done using Medcalc version 7.5. Results: Of 460 analysable patients, 88 patients (19%) had some eye manifestations, and 54 patients had human immunodeficiency virus retinopathy. Univariate analysis disclosed that immunosuppression (CD4 levels, <20/μL), positive C-reactive protein, associated eye lesions, and any central nervous system pathology were significant risk factors for the development of human immunodeficiency virus/acquired immunodeficiency syndrome retinopathy. Conclusions: Human immunodeficiency virus could be a risk factor for retinopathy as a significant number of patients did not have any other findings or risk factors for the development of retinopathy. However, it would be premature to draw definitive conclusions about the risk factors, as the number of patients analysed was small. © 2006 Scientific Communications International Limited.
Emplacement age and isotope geochemistry of Sung Valley alkaline-carbonatite complex, Shillong Plateau, northeastern India: Implications for primary carbonate melt and genesis of the associated silicate rocks
(2005) Rajesh K. Srivastava; Larry M. Heaman; Anup K. Sinha; Sun Shihua
The early Cretaceous (Albian-Aptian) Sung Valley ultramafic-alkaline-carbonatite complex is one of several alkaline intrusions that occur in the Shillong Plateau, India. This complex comprises calcite carbonatite and closely associated ultramafic (serpentinized peridotite, pyroxenite and melilitolite) and alkaline rocks (ijolite and nepheline syenite). Field relationship and geochemical characteristics of these rocks do not support a genetic link between carbonatite and associated silicate rocks. There is geochemical evidence that pyroxenite, melilitolite and ijolite of the complex are genetically related. Stable (C and O) and radiogenic (Nd and Sr) isotope data clearly indicate a mantle origin for the carbonatite samples. The carbonatite εNd (+0.7 to +1.8) and εSr (+4.7 to +7.0) compositions overlap the field for Kerguelen ocean island basalts. One sample of ijolite has Nd and Sr isotopic compositions that also plot within the field for Kerguelen ocean island basalts, whereas the other silicate-carbonatite samples indicate involvement with an enriched component. These geochemical and isotopic data indicate that the rocks of the Sung Valley complex were derived from and interacted with an isotopically heterogeneous subcontinental mantle and is consistent with interaction of a mantle plume (e.g. Kerguelen plume) with lithosphere. A U-Pb perovskite age of 115.1±5.1 Ma obtained for a sample of Sung Valley ijolite also supports a temporal link to the Kerguelen plume. The observed geochemical characteristics of the carbonatite rocks indicate derivation by low-degree partial melting (∼0.1%) of carbonated mantle peridotite. This melt, containing a substantial amount of alkali elements, interacted with peridotite to form metasomatic clinopyroxene and olivine. This process could progressively metasomatize lherzolite to form alkaline wehrlite. © 2004 Elsevier B.V. All rights reserved.
Assessing L. donovani Skin Parasite Load: A Proof of Concept Study of a Microbiopsy Device in an Indian Setting
(Frontiers Media S.A., 2021) Kristien Cloots; Om Prakash Singh; Abhishek Kumar Singh; Gert Van der Auwera; Prashant Kumar; Mallikarjuna Rao Gedda; Tulika Kumari Rai; Epco Hasker; Shyam Sundar; Marleen Boelaert
Background: In the endgame of the elimination initiative of visceral leishmaniasis (VL) on the Indian subcontinent, one of the main questions remaining is whether asymptomatically infected individuals also contribute to transmission. We piloted a minimally invasive microbiopsy device that could help answer this question. While the potential of this device has been previously illustrated in Ethiopia, no such information is available for the setting of the Indian subcontinent. In this proof of concept study we aimed to assess 1) to what extent skin parasite load obtained with the new microbiopsy device correlates with disease status, 2) to what extent skin parasite load correlates with blood parasite load in the same subject, and 3) to what extent the skin parasite load obtained from different sampling sites on the body correlates with one another. Methods: We performed a pilot study in Bihar, India, including 29 VL patients, 28 PKDL patients, 94 asymptomatically infected individuals, 22 endemic controls (EC), and 28 non-endemic controls (NEC). Presence of infection with L. donovani in the blood was assessed using Direct Agglutination Test, rK39 ELISA, Whole Blood Analysis measuring IFN-γ and qPCR. A skin sample was collected with the microbiopsy device on two different locations on the body. PKDL patients provided a third skin sample from the edge of a PKDL lesion. Parasite load in the skin was measured by qPCR. Findings: We found a clear correlation between the skin parasite load obtained with the microbiopsy device and disease status, with both higher skin parasite loads and higher proportions of positive skin samples in VL and PKDL patients compared to asymptomatics, EC, and NEC. No clear correlation between skin parasite load and blood parasite load was found, but a moderate correlation was present between the skin parasite load in arm and neck samples. In addition, we found four positive skin samples among asymptomatic individuals, and 85% of PKDL lesions tested positive using this microbiopsy device. Conclusions: In line with previous pilot studies, our results from an Indian setting suggest that the microbiopsy device provides a promising tool to measure skin parasite load, and – if validated by xenodiagnosis studies – could facilitate much needed larger scale studies on infectiousness of human subgroups. In addition, we advocate further evaluation of this device as a diagnostic tool for PKDL. © Copyright © 2021 Cloots, Singh, Singh, Van der Auwera, Kumar, Gedda, Rai, Hasker, Sundar and Boelaert.
Novel Mutations in the Crystallin Gene in Age-Related Cataract Patients from a North Indian Population
(S. Karger AG, 2017) Rashmi Patel; Ravish K. Zenith; Abhishek Chandra; Akhtar Ali
Cataract is the most prevalent leading cause of visual impairment and blindness worldwide. In comparison to congenital cataract, which affects relatively few individuals, age-related cataract is responsible for slightly half of all cases of blindness worldwide. Although significant work has been done, the genetic aspect of age-related cataract is still in its infancy. The current study was performed to analyze the mutations and polymorphisms in the CRYAA, CRYAB, CRYBB1, and GJA8 genes in 40 unrelated age-related cataract patients. Mutational analysis of the above-mentioned genes in 40 cataract cases revealed 14 different substitutions of which 8 variants were novel and 6 were reported SNPs. Two disease-causing mutations, g.44590631G>A (p.R65Q) and g.44592224G>A (p.R119H), were also observed in the CRYAA gene. The disease-causing variants mildly affect the stability, functionality, and localization of crystallin, and, with progressing age, a small change in the microenvironment of the crystallin lens occurs. This change in combination with a mutation may significantly alter the functionality of the crystallin protein, leading to age-related cataract. © 2017 S. Karger AG, Basel. All rights reserved.
Domestic Tourism Growth in India, Post COVID-19: Perspectives of Tour Operators
(Institute for Tourism, 2024) P.J. Shyju; V.G. Girish; Kaustav Chatterjee; Priyanka Singh
Domestic tourism in India recorded impressive growth and supported the local economy significantly in the last phase of the COVID-19 pandemic. The extant research on this topic covers the impact of the pandemic and resilience strategies. Still, it leaves a gap in the discussion relating to the service providers' experience in the context of domestic tourism. The present study stems from the absence of empirical research on the trends associated with domestic tourism growth in India post-COVID-19. It examines the trends in domestic tourist behaviour from the tour operators’ perspective. It employs a qualitative research design to explore the experiences of tour operators in India. Phone interviews were conducted with 26 tour operators to collect data. A thematic-content analysis is performed to generate themes with the help of Atlas ti software. The findings present the trends, preferences, motivations, and patterns of domestic growth tourism in India. © 2024 The Author(s).
Spatial heterogeneity in unintended pregnancy and its determinants in India
(BioMed Central Ltd, 2024) Anshika Singh; Mahashweta Chakrabarty; Aditya Singh; Shivani Singh; Rakesh Chandra; Pooja Tripathi
Background: Understanding the geographic variation of unintended pregnancy is crucial for informing tailored policies and programs to improve maternal and child health outcomes. Although spatial analyses of unintended pregnancy have been conducted in several developing countries, such research is lacking in India. This study addresses this gap by investigating the geographic distribution and determinants of unintended pregnancy in India. Methods: We analysed data from the National Family Health Survey-5 encompassing 232,920 pregnancies occurring between 2014 and 2021 in India. We conducted a spatial analysis to investigate the distribution of unintended pregnancies at both state and district levels using choropleth maps. To assess spatial autocorrelation, Global Moran’s I statistic was employed. Cluster and outlier analysis techniques were then utilized to identify significant clusters of unintended pregnancies across India. Furthermore, we employed Spatial Lag Model (SLM) and Spatial Error Model (SEM) to investigate the factors influencing the occurrence of unintended pregnancies within districts. Results: The national rate of unintended pregnancy in India is approximately 9.1%, but this rate varies significantly between different states and districts of India. The rate exceeded 10% in the states situated in the northern plain such as Haryana, Delhi, Uttar Pradesh, Bihar, and West Bengal, as well as in the Himalayan states of Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh. Moreover, within these states, numerous districts reported rates exceeding 15%. The results of Global Moran’s I indicated a statistically significant geographical clustering of unintended pregnancy rates at the district level, with a coefficient of 0.47 (p < 0.01). Cluster and outlier analysis further identified three major high-high clusters, predominantly located in the districts of Arunachal Pradesh, northern West Bengal, Bihar, western Uttar Pradesh, Haryana, Delhi, alongside a few smaller clusters in Odisha, Madhya Pradesh, Uttarakhand, and Himachal Pradesh. This geographic clustering of unintended pregnancy may be attributed to factors such as unmet needs for family planning, preferences for smaller family sizes, or the desire for male children. Results from the SEM underscored that parity and use of modern contraceptive were statistically significant predictors of unintended pregnancy at the district level. Conclusion: Our analysis of comprehensive, nationally representative data from NFHS-5 in India reveals significant geographical disparities in unintended pregnancies, evident at both state and district levels. These findings underscore the critical importance of targeted policy interventions, particularly in geographical hotspots, to effectively reduce unintended pregnancy rates and can contribute significantly to improving reproductive health outcomes across the country. © The Author(s) 2024.
Microstructures and microtextures of natural cokes: A case study of heat-affected coking coals from the Jharia coalfield, India
(Elsevier B.V., 2007) Ashok K. Singh; Mahendra P. Singh; Mamta Sharma; Sunil K. Srivastava
In Jharia coalfield, nearly 1250 Mt of coking coal has been devolatilized due to igneous intrusives and ∼ 1900 Mt due to mine fires. This paper is an effort to investigate the effect of carbonization in two intrusive affected coal seams of Ena (seam XIII) and Alkusa (seam XIV) collieries of this coalfield. Through petrographic studies by microscopy, characterization of normal and heat-affected coals was carried out. The microstructures and microtextures produced due to extraneous heat have been related to nature and extent of heat, location of heating source, and quality and quantity of natural coke produced. Based on the results of this study and earlier studies, an effort has been made to study the classification scheme for microtextures of natural cokes generated through in-situ carbonization of the coal seams. It has been observed that in case of such heat effects under overburden pressure, the anisotropy is much more pronounced as compared to laboratory-carbonized cokes. In the mildly carbonized coals (pre-plastic phase, < 300 °C) the vitrinite attained higher reflectance than normal vitrinite, liptinite started disappearing, and inertinite remained unaffected. In the moderately affected coals (plastic phase, 300-500 °C), mesophase spheres and fused natural cokes were generated from the reactives (vitrinite and liptinite maceral groups), the liptinites disappeared, and structurally, the inertinites remained almost unchanged with slight increase in the reflectance value. In the severely heat-affected coals (post plastic phase, > 500 °C) the identified microtextures were mesophase spheres, different shapes and sizes of natural cokes, graphitic sphaeroliths, pyrolytic carbons, inerts with morpho-structural changes and slightly higher reflectance values, and altered and unaltered mineral matters. A gradual change in the heat-affected coals with increasing temperature was observed with respect to location of intrusive body. It has been concluded that, barring the effect of pressure, the changes due to heat effect on coking coals, whether in situ or laboratory carbonization, are almost similar. Organic and inorganic constituents undergoing changes at a particular temperature are nearly similar in both conditions. In case of pronounced overburden pressure, flow structures develop in the natural coke groundmass. Higher reflectance and very strong anisotropy, as evidenced in completely baked coking coals with fine to very coarse mosaic structures, may be a good criterion to explore these heat altered coals for the carbon artifact industry and further efforts are required to be made in this line. © 2006 Elsevier B.V. All rights reserved.
A Late Cretaceous (ca. 90 Ma) kimberlite event in southern India: Implication for sub-continental lithospheric mantle evolution and diamond exploration
(Elsevier Inc., 2016) N.V. Chalapathi Rao; A. Dongre; Fu-Yuan Wu; B. Lehmann
We report groundmass perovskite U-Pb (SIMS) ages, perovskite Nd isotopic (LA-ICPMS) composition and bulk-rock geochemical data of the Timmasamudram diamondiferous kimberlite cluster, Wajrakarur kimberlite field, in the Eastern Dharwar craton of southern India. The kimberlite pipes gaver similar Mesoproterozoic ages of 1086 ± 19 Ma (TK-1, microcrystic variant) and 1119 ± 12 Ma (TK-3). However, a perovskite population sampled from the macrocrystic variant of TK-1 gave a much younger Late Cretaceous age of ca. 90 Ma. This macrocrystic kimberlite phase intrudes the Mesoproterozoic microcrystic phase and has a distinct bulk-rock geochemistry. The Nd-isotope composition of the ~1100 Ma perovskites in the cluster show depleted εNd(T) values of 2.1 ± 0.6 to 6.7 ± 0.3 whereas the ~90 Ma perovskites have enriched εNd(T) values of -6.3 ± 1.3. The depleted-mantle (DM) model age of the Cretaceous perovskites is 1.2 Ga, whereas the DM model age of the Proterozoic perovskites is 1.2 to 1.5 Ga. Bulk-rock incompatible trace element ratios (La/Sm, Gd/Lu, La/Nb and Th/Nb) of all Timmasamudram kimberlites show strong affinity with those from the Cretaceous Group II kimberlites from the Bastar craton (India) and Kaapvaal craton (southern Africa). As the Late Cretaceous age of the younger perovskites from the TK-1 kimberlite is indistinguishable from that of the Marion hotspot-linked extrusive and intrusive igneous rocks from Madagascar and India, we infer that all may be part of a single Madagascar Large Igneous Province. Our finding constitutes the first report of Cretaceous kimberlite activity from southern India and has significant implications for its sub-continental lithospheric mantle evolution and diamond exploration programs. © 2015 International Association for Gondwana Research.
Tax structure and economic growth in India: insights from ARDL model
(Emerald Group Holdings Ltd., 2020) Yadawananda Neog; Achal Kumar Gaur
Purpose: In the academic debate, the tax–growth relationship is always a controversial one. This paper aims to investigate the relationship between tax structure and economic growth in India for the period 1980-2016. After controlling for total tax revenue share to GDP in the estimation model, the authors examine the long-run and short-run relationship between tax structure and growth in India. Design/methodology/approach: Auto-regressive distributed lag (ARDL) model has been used in this study. This bound cointegration model has certain advantages to the traditional cointegration model. This study also applies the threshold cointegration test of Hansen and Seo (2002) for examining non-linearity in tax–growth nexus. Findings: The analysis shows that income tax share, corporation tax share and excise tax share are harmful to growth in the long-run. While the custom share is enlarging the growth performance. Corporation tax share is also reducing growth in the short-run. Following the Pesaran et al. (2001) approach of ARDL bound testing, the authors find the existence of a long-run relationship between studied variables. However, this study does not find any existence of threshold effect in the tax–growth relationship for India. Practical implications: Based on the empirical findings, the author suggests that the prime tax change, which has the potential to impact both long-run growth and short-run economic recovery is the reduction of corporate tax rate with sustainable revenue generation. It will definitely enlarge the foreign direct investment, saving and investment in India. Originality/value: This study will be a contribution to the empirical literature by investigating “tax–growth” relationship in the Indian case. To the knowledge, this will be the first study to examine this relationship for India with a recent data set. © 2020, Emerald Publishing Limited.

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