CURRENT MEASURES AGAINST OPHTHALMIC COMPLICATIONS OF DIABETES MELLITUS-A SHORT REVIEW

Diabetes mellitus (DM) is a metabolic disorder, whose prevalence is predicted to rise shortly. The present review focuses on the various ocular complications associated with DM, and the various ophthalmic formulation approaches developed to treat the same. Diabetic macular edema (DME), diabetic retinopathy, cataracts, and glaucoma are some of the major vision-threatening complications linked to DM. The ocular route of drug delivery has undergone several advancements in recent decades, the introduction of various novel drug delivery systems (DDS), various modifications in the existing formulation approaches, development of custom-designed personalized medications, being some of the major developments introduced in the field of ocular drug delivery. Due to the application of state-of-the-art technologies in the field of innovations related to ocular DDS, patients have been immensely benefited by the current modes of ocular treatment imparting fewer side effects, enhanced penetration, sustained drug effect, and so on. The present review includes and emphasizes the gradual development that has occurred from the conventional ophthalmic dosage forms to the currently reported novel ocular drug delivery approaches along with the related clinical research works

A marine to fluvial transition in the Paleoproterozoic Koolbye Formation, Turee Creek Group, Western Australia

Although no unambiguous biogenic criteria exist to discriminate Precambrian shallow-marine succes-sions from fluvial deposits, physical sedimentological evidence, including an association of primarysedimentary structures and textures, stratigraphic position, and comparison with Phanerozoic and Mod-ern examples has been found useful in identifying these deposit types. Our high resolution sedimentaryfacies analysis coupled with new mapping clearly indicates shallow-marine to beach-aeolian to fluvialsedimentation in the Paleoproterozoic Koolbye Formation of the Turee Creek Group, Western Australia.A falling stage systems tract within the Koolbye Formation has been documented. Our sedimentary faciesanalysis in combination with sedimentological analysis of the underlying Kungarra Formation indicatesdevelopment of at least three falling stage systems tracts within the Turee Creek Group across the rise ofatmospheric oxygen (the Great oxidation event).University of New South Wales (UNSW) and the Agouron Institute.http://www.elsevier.com/locate/precamres2016-03-31hb201

A squall by the seashore ca 2.3 billion years ago : raindrop imprints in a Paleoproterozoic tidal flat deposit, Kungarra Formation, Western Australia

In this contribution, we describe the occurrence of well-preserved Paleoproterozoic raindrop impact imprints on two surfaces of rippled siltstone–mudstone from the uppermost part of the Paleoproterozoic Kungarra Formation, Turee Creek Group, Western Australia. The raindrop imprints appear on the tops of two immediately overlying bedding surfaces in siltstone, near the top of a shallowing upward sequence that progresses from sandstone to mudstone. Imprints are circular to elliptical with an average diameter of 2–3 mm and a maximum length of 6.3 mm when elliptical. Flat ripple crest morphologies, varied ripple crest orientations, and marks of standing water in the ripple troughs indicate very shallow water conditions. When combined with sedimentological data from the underlying Kungarra Formation (shallow marine sandstones and siltstones), and mature quartz arenites of the overlying Koolbye Formation (mixed tidal, beach, fluvial and eolian), the interval examined is interpreted as a tidal flat deposited during a falling stage systems tract.University of New South Wales, Agouron Institute and University of New South Wales.http://www.tandfonline.com/loi/taje202016-09-30hb201

Late Neoarchaean-Palaeoproterozoic supracrustal basin-fills of the Kaapvaal craton : relevance of the supercontinent cycle, the "Great Oxidation Event" and "Snowball Earth"?

The application of the onset of supercontinentality, the “Great Oxidation Event” (GOE) and the first global scale glaciation in the Neoarchaean-Palaeoproterozoic as panacea-like events providing a framework or even chronological piercing points in Earth’s history at this time, is questioned. There is no solid evidence that the Kaapvaal craton was part of a larger amalgamation at this time, and its glacigenic record is dominated by deposits supporting the operation of an active hydrological cycle in parallel with glaciation, thereby arguing against the “Snowball Earth Hypothesis”. While the Palaeoproterozoic geological record of Kaapvaal does broadly support the GOE, this postulate itself is being questioned on the basis of isotopic data used as oxygen-proxies, and sedimentological data from extant river systems on the craton argue for a prolongation of the greenhouse palaeo-atmosphere (possibly in parallel with a relative elevation of oxygen levels) which presumably preceded the GOE. The possibility that these widespread events may have been diachronous at the global scale is debated.The National Research Foundation and University of Pretoria, South Africa.http://www.elsevier.com/locate/marpetgeonf201

A case study of microbial mat-related features in coastal epeiric sandstones from the Paleoproterozoic Pretoria group (Transvaal supergroup, Kaapvaal craton, South Africa) : the effect of preservation (reflecting sequence stratigraphic models) on the relationship between mat features and inferred paleoenvironment

The Magaliesberg Formation sandstones within the upper part of the Pretoria Group are interpreted as a second-order highstand systems tract within an overall clastic epeiric marine setting, where episodic braided fluvial systems fed sediment directly into a tidally dominated coastline setting. Mat-related features are abundantly preserved within the inferred tidal flat and supratidal deposits. The Daspoort Formation sandstones at a lower stratigraphic level are ascribed to a closely analogous palaeoenvironmental setting, yet have hardly any preserved mat features at all; they are ascribed to a second-order transgressive systems tract in a sequence stratigraphic framework. During highstand the depositional systems are inferred to have aggraded, thus preserving the mat-related features formed in Magaliesberg intertidal-supratidal environments. During second-order transgression, the formation of the wave/tidal ravinement surface in the subtidal/intertidal environments largely obliterated the features of the Daspoort intertidal and supratidal environments, leading to a paucity of mat-related structures in the preserved Daspoort succession. This case study thus supports the application of mat-related features to integrated palaeoenvironmental and sequence stratigraphic analysis, while emphasizing the role of preservation.The National Research Foundation, South Africa, and the University of Pretoria.http://www.elsevier.com/locate/sedgeonf201

Sedimentology, chemostratigraphy, and stromatolites of lower Paleoproterozoic carbonates, Turee Creek Group, Western Australia

The ca. 2.45–2.22 Ga Turee Creek Group, Western Australia, contains carbonate- rich horizons that postdate earliest Proterozoic iron formations, bracket both Paleoproterozoic glaciogenic beds and the onset of the Great Oxidation Event (GOE), and predate ca. 2.2–2.05 Ga Lomagundi-Jatuli C-isotopic excursion(s). As such, Turee Creek carbonate strata provide an opportunity to characterize early Paleoproterozoic carbonate sedimentation and carbon cycle dynamics in the context of significant global change. Here, we report on the stratigraphy, sedimentology, petrology, carbon isotope chemostratigraphy, and stromatolite development for carbonate-rich successions within the pre-glacial part of the Kungarra Formation and the postglacial Kazput Formation. Kungarra carbonate units largely occur as laterally discontinuous beds within a thick, predominantly siliciclastic shelf deposit. While this succession contains thin microbialite horizons, most carbonates consist of patchy calcite overgrowths within a siliciclastic matrix. C-isotopic values show marked variation along a single horizon and even within hand samples, reflecting spatially and temporally variable mixing between dissolved inorganic carbon in seawater and isotopically light inorganic carbon generated via syn- and post-depositional remineralization of organic matter. In contrast, the Kazput carbonates consist of subtidal stromatolites, grainstones, and micrites deposited on a mixed carbonate-siliciclastic shelf. These carbonates exhibit moderate δ13 C values of -2‰ to +1.5‰ and likely preserve a C-isotopic signature of seawater. Kazput carbonates, thus, provide some of the best available evidence that an interval of unexceptional C-isotopic values separates the Lomagundi-Jatuli C-isotopic excursion(s) from the initiation of the GOE as inferred from multiple sulfur isotopes (loss 4 of mass independent fractionation). The Kazput Formation also contains unusual, m-scale stromatolitic buildups, which are composed of sub-mm laminae and discontinuous, convex upward lenticular precipitates up to a few mm in maximum thickness. Laminae, interpreted as microbial mat layers, contain quartz and clay minerals as well as calcite, whereas precipitate lenses consist of interlocking calcite anhedra, sometimes showing faint mm-scale banding. These cements formed either as infillings of primary voids formed by gas emission within penecontemporaneously lithified mats, or as local seafloor precipitates that formed on, or within, surface mats. It is possible that both mechanisms interacted to form the unique Kazput stromatolites. These microbialites speak to a distinctive interaction between life and environment early in the Paleoproterozoic Era.Earth and Planetary Science

Palaeoproterozoic of India

The Indian shield represents a vast repository of the Palaeoproterozoic geological record. Built over the four large amalgamated Archaean nuclei (Dharwar, Bastar, Singhbhum and Aravalli–Bundelkhand) the major and minor Palaeoproterozoic sedimentary basins and supracrustal sequences in India are comparable in scale, and perhaps also in development, to those of North America, Africa, Australia and Brazil. The deformation of these supracrustal sequences, attendant metamorphism and emplacement of plutonic bodies hold important clues to their connection with major orogenies. Research in these areas has led to investigations into global correlation, which in turn has had a direct bearing on refining models of Palaeoproterozoic supercontinent assembly and break-up. This book covers various aspects of regional geology as well as broader issues of the Indian Palaeoproterozoic geology and its global context. It is an outcome of the UNESCO-IGCP 509 Palaeoproterozoic Supercontinents and Global Evolution research project. © 2012 The Geological Society of London

Petrography and geochemistry of Mesoarchaean komatiites from the eastern Iron Ore belt, Singhbhum craton, India, and its similarity with ‘Barberton type komatiite’

The Mesoarchaean supracrustals of the Gorumahishani–Badampahar belt, eastern India record sedimentation–volcanism like most other contemporary greenstone belts over the world. The current study reports unambiguous komatiitic rocks from Tua-Dungri hill, Gorumahishani–Badampahar belt, Jharkhand and presents a petrological and geochemical inventory of these very interesting rocks. The Tua-Dungri komatiites are characterised by a well distinguishable cumulate, platy and random spinifex zone. These Tua-Dungri komatiites are rich in SiO2 (47–50 wt%) like Barberton type komatiite or modern day boninite. Their Al depleted nature (Al2O3 = 1.36–2.95 wt%) with very low Al2O3/TiO2 (3.4–6.5) and high CaO/Al2O3 (2–3), high LREE/HREE ratios show further resemblance with the Barberton komatiite. The Tua Dungri komatiite data along with published geochemical, sedimentological and stratigraphic data from the Iron Ore Group of rocks suggest mantle plume activity during the Mesoarchaean on the Singhbhum craton

Detection and quantification of lack-of-penetration in Al-Al friction stir welded plates using phased array ultrasonic technique

This paper presents the results of phased array ultrasonic technique to detect the defects in friction stir welded Al-Al plates in three different processing conditions. Results of phased array ultrasonic were validated through ultrasonic c-scan imaging and real time radiography techniques. From the results it has been observed that the width and depth of the defect like lack-of-penetration can be successfully detected and quantified from the images of phased array ultrasonic technique