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Neuronal calcium sensor-1 (NCS-1) is the primordial member of a family of proteins responsible primarily for sensing changes in neuronal Ca(2+) concentration. NCS-1 is a multispecific protein interacting with a number of binding partners in both calcium-dependent and independent manners, and acting in a variety of cellular processes in which it has been linked to a number of disorders such as schizophrenia and autism. Despite extensive studies on the Ca(2+)-activated state of NCS proteins, little is known about the conformational dynamics of the Mg(2+)-bound and apo states, both of which are populated, at least transiently, at resting Ca(2+) conditions. Here, we used optical tweezers to study the folding behavior of individual NCS-1 molecules in the presence of Mg(2+) and in the absence of divalent ions. Under tension, the Mg(2+)-bound state of NCS-1 unfolds and refolds in a three-state process by populating one intermediate state consisting of a folded C-domain and an unfolded N-domain. The interconversion at equilibrium between the different molecular states populated by NCS-1 was monitored in real time through constant-force measurements and the energy landscapes underlying the observed transitions were reconstructed through hidden Markov model analysis. Unlike what has been observed with the Ca(2+)-bound state, the presence of Mg(2+) allows both the N- and C-domain to fold through all-or-none transitions with similar refolding rates. In the absence of divalent ions, NCS-1 unfolds and refolds reversibly in a two-state reaction involving only the C-domain, whereas the N-domain has no detectable transitions. Overall, the results allowed us to trace the progression of NCS-1 folding along its energy landscapes and provided a solid platform for understanding the conformational dynamics of similar EF-hand proteins.

Systemic amyloidosis is a fatal disease caused by misfolding of native globular proteins, which then aggregate extracellularly as insoluble fibrils, damaging the structure and function of affected organs. The formation of amyloid fibrils in vivo is poorly understood. We recently identified the first naturally occurring structural variant, D76N, of human β2-microglobulin (β2m), the ubiquitous light chain of class I major histocompatibility antigens, as the amyloid fibril protein in a family with a new phenotype of late onset fatal hereditary systemic amyloidosis. Here we show that, uniquely, D76N β2m readily forms amyloid fibrils in vitro under physiological extracellular conditions. The globular native fold transition to the fibrillar state is primed by exposure to a hydrophobic-hydrophilic interface under physiological intensity shear flow. Wild type β2m is recruited by the variant into amyloid fibrils in vitro but is absent from amyloid deposited in vivo. This may be because, as we show here, such recruitment is inhibited by chaperone activity. Our results suggest general mechanistic principles of in vivo amyloid fibrillogenesis by globular proteins, a previously obscure process. Elucidation of this crucial causative event in clinical amyloidosis should also help to explain the hitherto mysterious timing and location of amyloid deposition.

Holenarsipur Nucleus (HN) is one of the oldest part (3.5–3.1 Ga) of the continental crust of India. It is made up of mafic–ultramafic-komatitic (3.35 Ga) greenstone belts, migmatitic TTG (tonalite–trondhjemite–granodiorite 3.3 Ga) and diapiric trondhjemites (3.1 Ga). New major, trace and REE data on these rocks presented here provide constraints on adakite–TTG connection model and petrogenesis of these rocks of HN, in addition to recycling of the Early-Mesoarchaean basaltic crust and evolution of Mesoarchaean continental crust. Although of two different ages, the chemical characteristics of the migmatitic TTGs and diapiric trondhjemites of the HN resemble with the Archaean and Cenozoic high silica adakites (HSA), and the adakites from two Neoarchaean greenstone belts of Dharwar Craton, they also display similarities with the Early-Mesoarchaean TTGs from different cratons. Based on the compositional variations observed in TTG and diapiric trondhjemites of HN, we propose that plume fed, basaltic and/or basaltic komatiitic oceanic crust/slab flatly (shallow angle) subducted and melted under high Archaean geothermal regime to produce TTGs. Identification of HSA in 2.7 Ga old greenstone belt subduction complexes that are compositionally similar to TTG, suggests the possibility of continuation of this process into Neoarchaean and supports a genetic connection between TTG and adakites.

The 1.9 Ga Gwalior Group represents one of the major Paleoproterozoic depositional basin of Bundelkhand craton and is comprised of ∼1 km thick unmetamorphosed and undeformed sedimentary succession, with basal clastic sequence of sandstone-shale association (Par Formation) and an upper chemogenic BIF rich sequence (Morar Formation). The geochemical examinations of the basal clastic rocks are the subject of present study. The compositional maturity and extreme quartz enrichment in sandstones of Gwalior Group suggest slow upliftment and high in situ weathering of basement terrains in a stable platformal setting. These clastic sediments are characterized by strong depletion of mobile constituents like Ca, Sr and Na, high Plagioclase Index of Alteration (PIA) values and strong positive correlation between Al 2 O 3 and TiO 2 , indicating severe weathering of upper crust. Positive correlation between FeO (T) and TiO 2 suggests Fe retention in paleoweathering profiles and is attributed to oxygenated atmosphere. Post depositional potash metasomatism is indicated in A-CN-K systematics of these sediments and K-enrichment from near zero to as high as 38% is inferred, with most of the shale samples show ∼30% extraneous K 2 O additions. Depleted transition element (Ni, Cr, Co, Sc) contents, elevated large ion lithophile element (LILE) [K, Rb, Ba, Th, light rare earth elements (LREE)] contents, fractionated rare earth element (REE) patterns, strong negative Eu anomalies in these sediments point toward K-rich intracrustal granitic source component. Steeper REE patterns (Avg. La/Yb N ∼12.57) compared to basement granites and conspicuous depletion of Y over other LILEs in AUC normalized spidergram also suggest a heavy rare earth element (HREE) depleted TTG source component. Minor contribution from tholeiitic mafic rock is evidenced from Th/Sc–Sc, La/Sc–Sc/Th systematics and positive correlation of transition elements with FeO (T) and TiO 2 . Mixing calculations on the REE data suggest that upper continental crust of Bundelkhand craton was constituted of 40% granite, 40% TTG and 20% mafic rocks. This is in contrast with the present day composition of Bundelkhand Granite Gneiss Complex (BGGC) that contains ∼90% high K granite. The data suggest unroofing of granite batholiths by means of erosion and upliftment of supracrustal TTG cover.

Adakites are identified for the first time from a Neoarchaean active continental margin (ACM) preserved in the eastern part of the Shimoga schist belt, near Ranibennur, Western Dharwar Craton, India. These adakites consists mainly of quartz, plagioclase and minor amphiboles and are interlayered with the turbidites. They exhibit typical adakitic low Y (8.35–14.70 ppm) and Yb (0.85–1.47 ppm), may be classified as high SiO2 and low Mg#, Ni and Cr type adakites. Other constituents such as Na2O, K2O, Nb, Zr, LREE and HREE and their ratios such as Na2O/K2O, Zr/Sm, Nb/La, (La/Yb)n, (Gd/Yb)n and Th/U also closely resemble with the high silica adakites (HSA) of Martin et al. [Martin, H., Smithies, R.H., Rapp, R., Moyen, J.-F., Champion, D., 2005. An overview of adakite, tonalite–trondhjemite–granodiorite (TTG), and sanukitoid: relationships and some implications for crustal evolution. Lithos 79, 1–24]. Sr/Y values are moderate, generally lower than the high Sr–low silica Cenozoic adakites, but within the range of Archaean adakites. The negative Nb, Ta, and Ti anomalies characteristic of Cenozoic adakites are found in Ranibennur adakites also. Zr/Zr* and Hf/Hf* ratios are also similar to HSA. These adakites further depict compositional similarities with Meso and Neoarchaean tonalite–trondhjemite–granodiorites (TTGs). Such types of adakites have been experimentally generated by the partial melting of hydrous basalts, that are similar to adakitic glass veins (low MgO, CaO, Cr and Ni) found in peridotite xenoliths of Kamchatka arc [Xiong, X.L., Xia, B., Xu, J.F., Niu, H.C., Xiao, W.S., 2006. Na depletion in modern adakites via melt/rock reaction within the sub-arc mantle. Chem. Geol. 229, 273–292]. Since Archaean had higher geothermal regime, subduction of the basaltic slab was most probably shallow and significant mantle wedge was not available to react with adakitic melt. Hence Archaean adakites in general, and particularly from Ranibennur are relatively depleted in the peridotiitic mantle wedge components. Their identification from an Archaean ACM and their compositional similarities with the Paleo-Meso Archaean TTGs suggest the possibility of identical origin, i.e. the melting of a shallow hydrous basaltic slab. This mechanism during Archaean was widespread and rapid, resulted in faster continental crustal growth during the early history of the Earth. Identification of Archaean adakites in association with island arc turbidites from a greenstone belt sequence supports the rapid subduction mechanism for the crustal growth that coincides with 2.7 Ga peak (episode) of almost all geological processes.

Volcanic rocks of the Kushtagi–Hungund greenstone belt from the Eastern Dharwar Craton (EDC) show extreme diversity due to the presence of high-Mg, high Fe-, high Mg–Fe basalts, high Mg-dacites and andesites (boninitic affinities), and sodic–plagioclase–quartz rich felsic rocks (adakites with Na2O (∼4–6 wt.%). The adakites ( Drummond and Defant, 1990 , Martin, 1999 ) and high-Mg-dacites–andesites are being reported for the first time from greenstone belts of the Dharwar craton. Trace elements in these different types of volcanic rocks have distinct characteristics. For example, the basalts have (1) Al2O3/TiO2 ∼16 (PM value of 17), (2) (La/Yb)N∼1–3, (3) low order negative anomalies of Nb/Nb*, Zr/Zr*, Hf/Hf* and Ti/Ti*, (4) Zr/Nb ∼4–10 and (5) Ce/Nb ∼3–4. Two samples of andesites having Mg-enrichment and Al2O3/TiO2 ratios of 31–35 are interpreted to have boninitic affinities. Other dacites and andesites are characterized by (1) high-Mg (8–10 wt.%), (2) high Al2O3/TiO2=22–27, (3) Zr/Nb=8–14, (4) (La/Yb)N ∼2–7, (5) negative Nb/Nb*, Zr/Zr*, Hf/Hf* and Ti/Ti* anomalies and (6) Sc/Lu=67–172. The adakites are characterized by (1) a narrow range of SiO2 (67–70 wt.%), (2) enriched Na2O (4–6 wt.%) with very high Na2O/K2O (2.5–7.7), (3) Low Mg# (0.38–0.48), (4) high (La/Yb)N (13–31) with fractionated patterns, no Eu anomaly and (Gd/Yb)N=2–4, (5) very high Al2O3/TiO2 (50–80) and (6) enriched Ni, Cr and Co (total 50 ppm). These adakites resemble 3.0 Ga tonalite–trondhjemite gneisses of the Dharwar craton, which are interpreted as products of partial melting of the basaltic slab. The available data suggests that partial melting of the different mantle and slab sources generated this collage of compositionally different rocks within an island arc setting.

In the Dharwar Craton, southern India, gold deposits are found mostly along the six arcuate shear zones passing through late Archaean greenstone belts (2.7 Ga). One such shear zone complex extends for about 400 km within and along the Ramagiri–Hungund schist belt. The Penakacherla sector of this shear zone is excellently exposed, enabling a detailed investigation of synorogenic gold mineralisation and its relationship to associated hydrothermal alteration. Metamorphism and deformation under NE–SW compression associated with Archaean subduction processes converted mafic volcanic rocks into amphibolites and intermediate to felsic volcanic rocks into quartz mica schists. Continued compression generated a 50–100-m-wide shear zone complex consisting of mafic phyllonites. Advection of hydrothermal fluids through this shear zone and reaction between fluids and the mafic phyllonites resulted in a silicified, K-metasomatic assemblage mainly consisting of chlorite, amphibole, K-mica, plagioclase, ankerite, quartz, Fe-oxides, pyrite, chalcopyrite and arsenopyrite. Networks of quartz and carbonate veinlets, a few millimeters to a few centimeters thick, formed along the foliation planes giving rise to microscopic alteration envelope, in which individual veinlet systems are merged into one another to form a composite alteration system. Gold is found within these quartz veinlets, mafic phyllonites and at their mutual contacts. Hydrothermal fluids have modified the primary major, minor, trace and LREE compositions of host rocks such that their mutual behaviour became non-systematic. Some HFSE and HREE also show minor mobility but the overall REE pattern generally resembles that of the precursor mafic volcanic rocks. Mass and volume loss/gain by Si and Ca has made significant impact on Al, Ti and Zr abundances, which are generally immobile during hydrothermal alteration. However, element pairs such as Zr–Hf, V–Sc and Nb–Ta maintain primary inter-element ratios, although their absolute abundances are drastically diluted. Similarly, ΣREE in highly silicified and carbonatised samples are reduced, but patterns remain similar to those of relatively least altered mafic phyllonites with (La N /Yb) N between 1 and 3. In some samples, LREE enrichment is observed elevating in (La N /Yb) N from 3 to 11. Pathfinder elements and base metals such as As, Cd, Cu, Pb, Zn and Sb have been added along with the Au and Ag. δ 13 C of carbon varies from −16‰ to −21‰ suggesting a biogenic origin, whereas coexisting pyrite δ 34 S ranges from 1‰ to 3‰, pointing towards the involvement of magmatic or average crustal sulphur. Overall concentrations of K, Rb, Sr, Ba, Nb, Ta, Ti, Cs, Cr, Co, V, Y and Sc and many of the ratios such as K/Rb, La/Sc, La/Yb indicate that metamorphism, devolatilisation and dehydration of an oceanic subducting slab might have partially contributed the mineralising fluids and generated the alteration assemblage observed in the host rocks. Fluid sources were mantle and greenstone belt dehydration and devolatilisation generating observed compositional and alteration diversity.

Detailed geological, petrological and geochemical studies have been carried out on an arenite–quartzwacke suite of rocks constituting a part of the Late Archaean Sandur schist belt in Dharwar craton, southern India for understanding the nature of provenance for these sedimentary rocks. The arenite–quartzwacke consists of rounded to sub-rounded and angular fragments of monocrystalline–polycrystalline quartz, quartzite and chert embedded in a fine-grained matrix of quartz and sericite. While arenites are more siliceous (SiO 2 , 80–92 wt.%), the quartzwacke have relatively lower silica content (ca. 69–78 wt.%). The arenites and quartzwackes have CIA values ranging from 76 to 96 which suggest intense chemical weathering. This is further corroborated by the positive correlation between Al 2 O 3 and TiO 2 in both these rock types. The ACNK modeling of arenites and quartzwackes show evidence for addition of K 2 O during later metasomatic alteration. In the ACNKFM ternary diagram all the samples plot along a mixing line between chlorite and sericite indicating alteration during K-metasomatism and the presence of mafic rocks in the source. The high concentration of HFSE such as Zr, Hf, Nb and Ta and the trace element ratios Th/Sc, La/Sc, Th/U and Ce/Th in the arenite–quartzwacke indicate a mixed provenance. The rare earth element modeling of quartzwackes considering tonalite, granite and amphibolite end members in the provenance suggests equal proportions of mafic and felsic end members. A composition comprising of 25% tonalite+25% granite+50% amphibolite in the provenance appears to match with the observed range of REE patterns of quartzwackes. The presence of higher proportions of granite in the provenance is evidenced by the large negative Eu anomalies in these sediments. Field evidence and structural discordance suggest that the arenite–quartzwacke suite is an allochthonous part of the Sandur schist belt.

A realistic model has bene developed for the hydrodynamics and mass transfer in a cocurrent packed column. It postulates that the liquid phase is divided into stagnant and dynamic regions. Unlike in other models, the stagnant phase is not completely mixed and its concentration profile is given by a Fickian-type model equation. The model considers axial dispersion in the dynamic phase and mass transfer between the stagnant and dynamic regions of the liquid phase. The resulting partial differential equations are solved numerically by the method of orthogonal collocation. Simulation results highlighting the effects of various parameters for a step input and a step decrease in tracer concentration are also presented. The model predictions for both the downflow and upflow modes of operation are compared with available experimental data and are found to agree well.

Syngenetic microbial trichomes are recorded from a black chert band interlayered with the banded iron formation belonging to the > 2.6-Ga-old Sandur Schist Belt of the Dharwar sequence, Karnataka, India. The iron formation has interbeds of mafic pillow lava and tuffs. Although the fossil microbial community consists of highly biodegraded mats, some well-preserved structurally mineralized trichomes are also present. Electron microprobe analysis shows high percentage of SiO 2 and P 2 O 5 in the filaments and the presence of carbon along the margins of some filaments. Rare earth element and isotopic data indicate a higher oxygen concentration than hitherto considered for Archaean seawater. In the present context there is presumptive evidence to suggest that this oxygen was produced by the photosynthetic activity of microbial biocoenoses.

The evolution of the Indian Shield has been envisaged from the analysis of available tectono-lithostratigraphic, geochronological, geochemical and geophysical data. It appears that the Dharwar schist belts and their equivalents, except the Kolar schist belt, are not typical greenstone belts, but are representative of a transitional era of rapid transformation from simatic to sialic crust. In the Archaean—Proterozoic tract of India, relics of rocks older than 3.0 b.y. are identified in five widely separated regions of distinct tectono-litho-stratigraphic assemblages which probably represent the primordial continental nucleii. It is suggested that the growth of the Indian Shield has taken place through nucleation, accretion and merger into three protocontinents named Dharwar, Aravalli and Singhbhum. The cratonisation of the Indian unit seems to have been rapid and almost completed by the middle Proterozoic, as there is no significant variation in the composition of the clastic sediments and basalts from middle Proterozoic onwards. The continental nucleii appear to merge along the deep-seated lineaments, which are reflected on the tectonic map of India. Further, the Dharwar, Aravalli and Singhbhum protocontinents also seem to merge along a Y=shaped Narmada—Son—Godavari lineament which along with the Mahanadi lineament, between the two continental nucleii of the Singhbhum protocontinent have later developed into rift valleys.

Geochemical and petrological studies on serpentinised ultramafics of Kadakola, Mysore State, India, indicate that the Archaean mantle beneath the Indian Shield was of peridotitic in nature. This protomantle in the Archaean period was undifferentiated with higher concentrations of siderophile and transitional elements.

New and improved syntheses of 4,5,7,8-tetrafluoro- and 4,5,7,8,12,13,15,16-octafluoro[2.2]paracyclophanes are described. The preparation of the new compound, 4,5,7,8-tetrafluoro[2.2]metaparacyclophane, is outlined.

Summary The effect of exogenous sugars on the kinetics of 14C-IAA transport in etiolated Zea mays L. coleoptile segments was determined. Supplying sugars through the donor blocks enhances absorption and translocation of the applied 14C-IAA. There was no difference between sucrose, ribose and glucose or the various concentrations of sucrose on auxin transport parameters. Sucrose supplement neither affected the velocity nor the polarity of auxin transport under the present experimental conditions.

Summary Zea mays L. seedlings were grown in light and in darkness and the effect of light or darkness on various parameters of auxin transport was studied. It has been observed that seedlings grown in the light absorb significantly less auxin than their dark grown counterparts. Light during transport period also reduced significantly the transport intensity of both etiolated and light grown segments. However, it had no material effect on the linear velocity of auxin transport in etiolated segments, although the velocity decreased in darkness of segments grown in the light. Acropetal uptake, though not influenced by light during the transport period, was found to be greater in non-etiolated segments.

Static bioassays were conducted to determine acute toxicities of Basagran®, diquat and Cutrine-plus® to mosquitofish, Gambusia affinis. The mean fish weight was 0·321 g and the length 3·08 cm. Twenty four and 96 h exposure to Basagran, diquat and Cutrine-plus was done in concentration ranges (ppm) 0–5500, 0–1500, and 0–550, respectively. LC10, LC50 and LC99 values were calculated by a computerized probit analysis program. Cutrine-plus was the most toxic compound, followed by diquat and Basagran, having the 24 and 96 h LC50 values (ppm) as 290 and 170, 723 and 289, 4418 and 3874, respectively. Cutrine-plus was 15·2 and diquat 6·1 times more toxic than Basagran to mosquitofish. Toxicity signs in diquat-treated fish were gill-haemorrhage, lethargy and extensive defecation. In Cutrine-plus, they lost equilibrium and swam near the water surface. The skin colour of Basagran-treated fish turned bluish, and protrusion of a nematode worm Camallanus oxycephala was frequently observed from the body-wall of infested fish.

Metamorphosed Archaean sediments comprise ∼ 35% of the 3.5 Ga old Holenarasipur schist belt (HNSB) and 90% of the 3.2 Ga old Javanahalli schist belt (JSB) of the Dharwar Craton. The high-alumina sediments of the HNSB are variable in their major, LIL and ferromagnesian trace elements. The REE patterns are variable, with both positive and negative Eu anomalies. Cr and Ni are more abundant than in most of the detrital sediments, at corresponding silica contents. Al and Cr show positive correlation. The Th/U, La/Th, Ba/La and Zr/La ratios and abundances show a large-scale scatter. The paragneisses of JSB also have a variable major element composition, but uniform REE patterns and abundances, with strong negative Eu anomalies similar to some Archaean tonalitic gneisses and Phanerozoic shales and quartzites. The para-amphibolites, stratigraphically above these gneisses, have depleted flat-REE patterns and positive Eu anomalies. The HNSB sediments are probably derived from a source consisting of mafic, ultramafic, anorthositic and acid volcanic rocks. In contrast, the source area for JSB sediments had considerable acid plutonic rocks. This indicates that the processes of sial formation started soon after the HNSB group had been deposited and continued through the development of the younger greenstone belts. Rapid nucleation and development of continental crust occurred during the interval 3.5 to 3.2 Ga.

The acute toxicities of two commercial herbicides, paraquat and metribuzin (Sencor®), were determined by 24- and 48-h static bioassay tests on freshwater copepods comprising 91% calaoids (Diaptomus mississippiensis Marsh) and 9% cyclopoids (Eucyclops agilis Koch). The 24-h LC50 values for paraquat and metribuzin were 10 and 205 ppm and the 48-h LC50 values were 5 and 150 ppm, respectively. Mortality rates were dosage-dependent for both herbicides. Mixing of paraquat and metribuzin in a 1:1 ratio reduced the toxicity of paraquat by increasing its LC50 values from 10 to 29 and 5 to 17 ppm for 24 and 48 h, respectively. The more than theefold decrease in the toxicity of paraquat is inexplicable but it exhibits a clear antagonism when used in combination with metribuzin.

Four distinct geological settings appear to have existed in the Indian Peninsula during the Precambrian Era. These are represented by (1) Early and Middle Archaean 1 ‘true greenstone belts’ of Holenarasipur, Nuggihalli, Kolar and Sargur, (2) Late Archaean—Early Proterozoic ‘greenstone-like geosynclinal piles’ of Shimoga-Chitradurga, (3) high-grade derivatives of greenstones and granulites of Tamil Nadu-Kerala and (4) Proterozoic platforms of Cuddapah-Vindhyan basins. The ‘greenstone belts’ of Holenarasipur type are elongated, sometimes symmetrical, belts of rhythmic volcanism and fine-grained detrital and chemical sedimentation. The base of these greenstone belts is made up of basic and ultrabasic flows of komatiitic affinities and these are intruded by tonalites and trondhjemites. The main Dharwar greenstone-like geosynclinal piles start with orthoquartzite-carbonate facies showing ripple marks and current-bedding and these develop into thick, graded-bedded eugeosynclinal piles and do not show the characteristic rhythmic volcanism, sedimentation and symmetry of ‘true greenstone belts’. Their volcanism is of a calc-alkaline type. Recent data on these geological settings from the South Indian Shield suggest a thin simatic protocrust with a highly undifferentiated protomantle existing during the Early and Middle Archaean. In the cracks developed due to degassing of the protomantle, ‘true greenstone belts‘ were laid down and the products of partial melting of the basic crust at comparatively shallow depth, i.e. tonalite-trondhjemites were emplaced. This process formed the continental nuclei of mixed, but predominantly basic, composition. Between these continental nuclei, geosynclines were formed in which Dharwar-type greenstone piles were laid down. Partial melting of the lower crust of the upper mantle, at a deeper level than the depth of genesis of trondhjemite, gave rise to potassic granites and resulted in more than two (?) episodes of widespread potash reactivation marking the completion of cratonisation, following which emplacement of dike swarms took place.

Stromatolites have been found in the cherty dolomite member of the Vanivilas Formation of the Chitradurga Group belonging to > 2600 Ma old Archaean Dharwar Supergroup, South India. They occur in the Bhimasamudra, Marikanve and Dodguni areas of the Chitradurga schist belt. The stromatolites of the Bhimasamudra and Marikanve areas are described here for the first time. The stromatolites of Bhimasamudra consist of cylindrical and terete columns, as well as pseudocolumns with concave tops developed on a wavy base. Coalescence of columns and γ-type branching have been noticed. The Marikanve stromatolites are stratiform, often grading into pseudocolumnar and dome-shaped types. Naked stromatolite columns showing β-type and markedly divergent branching are found in the Dodguni area. The Bhimasamudra and Dodguni stromatolites probably developed in an intertidal environment and the Marikanve ones in a subtidal environment.

This paper deals with the evaluation of screened-hydrogenic orbitals for a many-electron atom. Expressions for Slater intergrals and their derivatives with respect to the effective nuclear charges are given. The dipole matrix elements are evaluated for screened-hydrogenic orbitals as a function of the scaled nuclear charges of the initial and the final states of the active electron. Comparisons of predicted energies and transition integrals with experimental values and those based on the self-consistent field method are given.

The Chitradurga base metal sulfide deposit is associated with eugeosynclinal metabasalts (∼ 2.5 b.y.) and banded pyritiferous cherts. The pre-tectonic character of the deposit and meta-volcanics is indicated by their deformational textures, structures and radioactive age data. The mineral assemblages of these ores are similar to the Zn-Cu type of massive sulfide deposits associated with Archean—Early Precambrian eugeosynclinal metavolcanics in other shield areas. The deposit has a rather high concentration of Co; microprobe data indicate that most of it is found as cobaltite and linnaeite and that it is inhomogenously distributed in these minerals. Very strong sympathetic correlation between Co and Cu, and the simultaneous increase of both of these elements with depth has been found. The geochemistry of the Chitradurga ores and metabasalts, especially their Zn:Cu:Pb and Pb:Zn ratios, suggests that the base metal sulfide content is probably genetically related to the basaltic flows. It appears that the Chitradurga deposit belongs to the ‘massive volcanogenic’ Cu-rich class of sulfide deposits. The metal content of the ores appears to have been supplied by rapidly degassing highly undifferentiated protomantle along with the basaltic magma.

Summary Abscisic acid inhibits 14C-IAA transport without influencing the uptake or the basipetal velocity. Based on these observations a modification in Curry 's hypothesis for phototropism has been proposed.