Protocol of the Cognitive Health in Ageing Register: Investigational, Observational and Trial Studies in Dementia Research (CHARIOT): Prospective Readiness cOhort (PRO) SubStudy

The Cognitive Health in Ageing Register: Investigational, Observational and Trial Studies in Dementia Research (CHARIOT): Prospective Readiness cOhort (PRO) SubStudy (CPSS), sponsored by Janssen Pharmaceutical Research & Development LLC, is an Alzheimer's disease (AD) biomarker enriched observational study that began 3 July 2015 CPSS aims to identify and validate determinants of AD, alongside cognitive, functional and biological changes in older adults with or without detectable evidence of AD pathology at baseline. CPSS is a dual-site longitudinal cohort (3.5 years) assessed quarterly. Cognitively normal participants (60-85 years) were recruited across Greater London and Edinburgh. Participants are classified as high, medium (amnestic or non-amnestic) or low risk for developing mild cognitive impairment-Alzheimer's disease based on their Repeatable Battery for the Assessment of Neuropsychological Status performance at screening. Additional AD-related assessments include: a novel cognitive composite, the Global Preclinical Alzheimer's Cognitive Composite, brain MRI and positron emission tomography and cerebrospinal fluid analysis. Lifestyle, other cognitive and functional data, as well as biosamples (blood, urine, and saliva) are collected. Primarily, study analyses will evaluate longitudinal change in cognitive and functional outcomes. Annual interim analyses for descriptive data occur throughout the course of the study, although inferential statistics are conducted as required. CPSS received ethical approvals from the London-Central Research Ethics Committee (15/LO/0711) and the Administration of Radioactive Substances Advisory Committee (RPC 630/3764/33110) The study is at the forefront of global AD prevention efforts, with frequent and robust sampling of the well-characterised cohort, allowing for detection of incipient pathophysiological, cognitive and functional changes that could inform therapeutic strategies to prevent and/or delay cognitive impairment and dementia. Dissemination of results will target the scientific community, research participants, volunteer community, public, industry, regulatory authorities and policymakers. On study completion, and following a predetermined embargo period, CPSS data are planned to be made accessible for analysis to facilitate further research into the determinants of AD pathology, onset of symptomatology and progression. The CHARIOT:PRO SubStudy is registered with clinicaltrials.gov (NCT02114372). Notices of protocol modifications will be made available through this trial registry. [Abstract copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Crustal architecture and tectonic evolution of the Cauvery Suture Zone, southern India

Abstract not availableT.R.K. Chetty, T. Yellappa, M. Santos

Mineral chemistry of isotropic gabbros from the Manamedu Ophiolite Complex, Cauvery Suture Zone, southern India: evidence for Neoproterozoic suprasubduction zone tectonics

Abstract not availableT. Yellappa, T. Tsunogae, T.R.K. Chetty, M. Santos

The Neoproterozoic subduction complex in southern India: SIMS zircon U-Pb ages and implications for Gondwana assembly

The Palghat-Cauvery Suture Zone (PCSZ) in southern India defines the trace of the collisional suture developed during the assembly of the Gondwana supercontinent through the closure of the Mozambique Ocean in the Late Neoproterozoic-Cambrian. Here we report Secondary Ion Mass Spectrometry (SIMS) U-Pb ages from zircons in plagiogranites and gabbros from a suprasubduction zone ophiolitic complex at Manamedu, located along the southern periphery of the PCSZ. The morphology and internal structures, together with the high Th/U values of the zircons from the plagiogranite suggest a magmatic crystallization history. The dominant population of zircons in the two plagiogranite samples analyzed in this study yield 206Pb/ 238U ages of 737±23Ma and 782±24Ma corresponding to the timing of emplacement of these rocks. The plagiogranite from Manamedu also contains two other zircon populations: the first group shows a discordant population with 207Pb/ 206Pb ages between 2278 and 2527Ma with an upper intercept age of 2418±65Ma. Similar Neoarchean-early Paleoproterozoic ages have been widely reported from the surrounding rocks within the PCSZ and also from the Salem Block to the north. We interpret these older zircons as xenocrysts entrained in the plagiogranite during magma ascent and consolidation. The third group of zircons in the plagiogranite yield 206Pb/ 238U age of 513±4.6Ma, comparing well with the Cambrian ages reported in several recent studies from magmatic and metamorphic rocks in the PCSZ and the crustal blocks to the south, correlating with the tectono-thermal events associated with the collision and post-collisional extension associated with the assembly of the Gondwana supercontinent. Zircons in the two gabbro samples from the Manamedu complex analyzed in this study yield well-defined clusters on the concordia and show weighted mean 206Pb/ 238U ages of 744±11Ma and 786±7.1Ma. The internal structure of the zircons from these gabbro samples and their high Th/U values also suggest a magmatic crystallization history. The zircon ages that we obtained from the Manamedu forearc complex also compare with the recently reported zircon age of 825±17 from the gabbro-anorthosite complex and the 766±8Ma age from oscillatory-zoned euhedral crystals of magmatic zircons in felsic volcanic suite of the Kadavur Dome, to the south of Manamedu. The ages also compare with the 819±26Ma 206Pb/ 238U age reported from zircons in arc-related rapakivi granite from an adjacent locality within the PCSZ. All these data suggest a prominent mid Cryogenian subduction system along the southern periphery of the PCSZ prior to the destruction of the Mozambique Ocean lithosphere and the final amalgamation of the Gondwana supercontinent. © 2011 Elsevier B.V.M. Santosh, W.J. Xiao, T. Tsunogae, T.R.K. Chetty, T. Yellapp

Tectonic history and occurrence of 2.4 Ga mafic dyke swarms adjacent to Godavari Basin, Karimnagar, India

Proterozoic dyke swarms are exposed partly in granulitic terrain and partly in gneissic terrain and extend in a NE–SW direction near the Godavari Basin, Karimnagar area, Central India. The Karimnagar dyke swarm petrographically exhibits two groups such as fresh plagioclase and pyroxene phenocrystic dolerite dykes and altered non-phenocrystic gabbros. Dolerites show ophitic to sub-ophitic textures and gabbros are non-porphyritic and more altered. Geochemical data suggests that these dykes are tholeiitic in nature, range from basalt to basaltic andesite in composition. The rare earth element patterns show enrichment of light rare earth elements (25–60 times) and heavy rare earth elements show flat patterns (4–10 times) supporting the presence of two varieties within the dyke swarm. A laser probe 40Ar/39Ar study and Ar isotopic analyses suggest two magmatic emplacement ages at 2400 Ma and 2200 Ma which are present within the dyke swarm. Palaeomagnetic results reveal a characteristics remnant magnetization vector of Dm = 52.5, Im = –24.5 (K = 21.81, ?95 = 8.65°, N = 12) and supports the presence of two phases of dyke activity in the region

Occurrence of lamproitic dykes at the northern margin of the Indravati Basin, Bastar Craton, Central India

Occurrence of two lamproitic dykes intruding the basement granite near Khadka village at the northern margin of the Indravati Basin, Bastar craton is reported. Combined field, microscopy, XRD, EPMA and whole-rock geochemical investigations reveal that these lamproites were subjected to high degree of hydrothermal alteration as well as possible metamorphism. However, relicts of their original textures are well-preserved thereby providing important clues as to the nature of the protolith. Quartz, carbonate, chlorite and phlogopite constitute the bulk mineralogy whereas spinel, apatite and iron oxides are the accessory phases. Chemical composition of the groundmass spinels are strikingly similar to those from the lamproites. The Khadka lamproite dykes display high abundances of compatible elements such as Ni (238–396 ppm), Cr (484–892 ppm), and V (160–200 ppm) as well as high-field strength elements such as Zr (719–2057 ppm) and Nb (92–126 ppm) that resemble those in lamproites. Khadka lamproites also have high whole-rock REE abundances (ΣREE up to 1260 ppm) and display fractionated chondrite-normalized REE patterns (La/Yb= 113–237) which together with their average compatible and incompatible trace elemental ratios (e.g. Nb/Zr, Nb/La, Ba/Rb) are strikingly similar to those of the Mesoproterozoic Krishna lamproites of the Eastern Dharwar craton. Available field evidences suggest the Khadka lamproites to be of at least Palaeoproterzoic age (1.88 Ga) which makes them some of the oldest such rocks as yet documented from the Indian shield

The mafic-ultramafic complex of Aniyapuram, Cauvery Suture Zone, southern India: Petrological and geochemical constraints for Neoarchean suprasubduction zone tectonics

Abstract not availableT. Yellappa, V. Venkatasivappa, T. Koizumi, T.R.K. Chetty , M. Santosh, T. Tsunoga

Mega sheath fold of the Mahadevi hills, Cauvery Suture Zone, Southern India: implication for accretionary tectonics

The Mahadevi hills, located in the axial zone of Cauvery Suture Zone, comprise a sequence of granulite facies rocks represented by garnet-bearing pyroxene granulites and quartzo-feldspathic gneisess interfolded with banded iron formations. Structural mapping with hand held GPS reveals that the Mahadevi hills constitute a mega sheath fold structure exposing well developed easterly plunging extension lineations. Depressional and culmination surfaces are well demarcated in association with elliptical map patterns. The development of the mega sheath fold structure is genetically related to the regional thrust-nappe tectonics, supporting the model of subduction-accretion-collisional history for the evolution of the Cauvery Suture Zone.T.R.K. Chetty, T. Yellappa, D.P. Mohanty, P. Nagesh, V.V. Sivappa, M. Santosh and T. Tsunoga

Private practitioners' contributions to the Revised National Tuberculosis Control Programme in a South Indian district

SETTING: Tumkur District, South India. OBJECTIVE: To assess the participation of for-profit, formal private practitioners (PPs) under the Revised National Tuberculosis Control Programme's (RNTCP's) public-private mix (PPM) schemes and document their contribution to RNTCP pulmonary tuberculosis (TB) case finding. DESIGN: RNTCP reports at district TB centre were reviewed. PPs were mapped and their referrals of presumptive TB cases to the RNTCP during 2011 were assessed using laboratory registers at designated microscopy centres (DMCs). RESULTS: None of the 424 PPs had signed up for any PPM scheme. However, 22% made at least one referral to a DMC in 2011. PP referrals constituted 15% of the presumptive TB cases examined at the DMCs, and PPs contributed to 23% of the sputum smear-positive TB cases detected. Among PP referrals, the proportion of confirmed smear-positive cases was high (24%). CONCLUSION: Fifteen years after the start of PPM, formal engagement of PPs with RNTCP was nonexistent. However, PPs do refer cases to the RNTCP and contribute to a fraction of TB case detection. The high proportion of confirmed sputum smear-positive cases suggests that PPs tend to make selective referrals. More efforts are needed to promote the engagement of PPs in the RNTCP

A Neoarchean dismembered ophiolite complex from southern India: Geochemical and geochronological constraints on its suprasubduction origin

Abstract not availableT. Yellappa, M. Santosh, T.R.K. Chetty, Sanghoon Kwon, Chansoo Park, P. Nagesh, D.P. Mohanty, V. Venkatasivapp