Molecular Docking Study of Conformational Polymorph: Building Block of Crystal Chemistry

Two conformational polymorphs of novel 2-[2-(3-cyano-4,6-dimethyl-2-oxo-2H-pyridin-1-yl)-ethoxy]-4,6-dimethyl nicotinonitrile have been developed. The crystal structure of both polymorphs (1a and 1b) seems to be stabilized by weak interactions. A difference was observed in the packing of both polymorphs. Polymorph 1b has a better binding affinity with the cyclooxygenase (COX-2) receptor than the standard (Nimesulide)

Indo-Brazilian Late Palaeozoic wildfires: an overview on macroscopic charcoal

Carvão vegetal macroscópico é amplamente aceito como um indicador direto da ocorrência de paleo-incêndios vegetacionais, sendo relativamente bem estudado e distribuído de forma homogênea em depósitos do Paleozoico Superior da Euramérica e Cataísia. Por outro lado, apenas alguns registros deste tipo de material foram publicados para o Paleozoico Superior do Gondwana e, somente recentemente foi demonstrado que carvão vegetal macroscópico (e, portanto, incêndios) também é comum no continente meridional. Os mais importantes registros do Gondwana se constituem em fragmentos carbonizados de lenhos gimnospérmicos e estão associados, principalmente, a depósitos de carvão mineral. Registros de macro-charcoal (carvão vegetal macroscópico) foram descritos para níveis do Paleozoico Superior da Bacia Damodar (Índia) e da Bacia do Paraná (Brasil), demonstrando que paleo-incêndios vegetacionais ocorriam em sequências e intervalos estratigráficos variados no Gondwana durante esse período. Com base nos registros publicados até o momento e em novos exemplares provenientes do nível de carvão Seam-IV, Formação Raniganj, Bacia Damodar (Lopingiano da Índia), uma revisão acerca dos registros indo-brasileiros de carvão vegetal macroscópico em níveis do Paleozoico Superior são apresentados. O material inédito foi analisado sob Microscópio Eletrônico de Varredura para a definição de características anatômicas, sendo estabelecida uma afinidade gimnospérmica para os fragmentos. Os dados apresentados reforçam a importância dos paleo-incêndios vegetacionais como elemento perturbador dos diferentes paleoambientes gondvânicos durante o Paleozoico Superior.Sedimentary charcoal is widely accepted as a direct indicator for the occurrence of paleo-wildfires and, in Upper Paleozoic sediments of Euramerica and Cathaysia, reports on such remains are relatively common and (regionally and stratigraphically) more or less homogeneously distributed. On the contrary, just a few reliable records have been published for the Late Paleozoic of Gondwana and only recently it has been demonstrated that macroscopic charcoals (and thus fires) were also common in the southern continent during this period. The most important Gondwanan records are predominantly charred gymnosperm woods mainly related to coal bearing strata. Late Paleozoic macro-charcoal occurs in both, the Damodar Basin (India) and the Paraná Basin (Brazil), demonstrating that paleo-wildfires were spread out in different sequences and distinct stratigraphic intervals during this period in Gondwana. Based on the so far published records as well as new samples from the Seam-VI coalfield, Raniganj Formation (Damodar Basin – Lopingian of India), an overview of the Late Paleozoic Indo‑Brazilian macro-charcoal remains is presented. The hitherto unpublished samples were anatomically analyzed under Scanning Electron Microscope and a gymnosperm affinity could be established. The data presented here reinforce the relevance of paleo-wildfire as a source of environmental disturbance over large areas of Gondwana during the Late Paleozoic

Thecamoebians (Testate Amoebae) Straddling the Permian-Triassic Boundary in the Guryul Ravine Section, India: Evolutionary and Palaeoecological Implications

Exceptionally well-preserved organic remains of thecamoebians (testate amoebae) were preserved in marine sediments that straddle the greatest extinction event in the Phanerozoic: the Permian-Triassic Boundary. Outcrops from the Late Permian Zewan Formation and the Early Triassic Khunamuh Formation are represented by a complete sedimentary sequence at the Guryul Ravine Section in Kashmir, India, which is an archetypal Permian-Triassic boundary sequence. Previous biostratigraphic analysis provides chronological control for the section, and a perspective of faunal turnover in the brachiopods, ammonoids, bivalves, conodonts, gastropods and foraminifera. Thecamoebians were concentrated from bulk sediments using palynological procedures, which isolated the organic constituents of preserved thecamoebian tests. The recovered individuals demonstrate exceptional similarity to the modern thecamoebian families Centropyxidae, Arcellidae, Hyalospheniidae and Trigonopyxidae, however, the vast majority belong to the Centropyxidae. This study further confirms the morphologic stability of the thecamoebian lineages through the Phanerozoic, and most importantly, their apparent little response to an infamous biological crisis in Earth's history

The Permian-Triassic palynological transition in the Guryul Ravine section, Kashmir, India: implications for Tethyan – Gondwanan correlations

This first palynological study of the Permian–Triassic succession in the Guryul Ravine, Kashmir, India, reveals impoverished latest Permian spore-pollen assemblages in the uppermost Zewan Formation, a rich palynoassemblage from the basal Khunamuh Formation characteristic of the Permian–Triassic transition zone and depleted Triassic assemblages from higher in the Khunamuh Formation. The collective assemblages can be broadly correlated to the Densipollenites magnicorpus and Klausipollenites decipiens palynozones of peninsular India and to palynofloras spanning the Permian–Triassic boundary elsewhere in Gondwana. Generally, low spore-pollen yields and poor preservational quality of the studied assemblages hinder more precise correlations and are inferred to be a function of an offshore marine depositional setting on the margin of the Neotethys Ocean, and thermal alteration associated with Cenozoic collisional tectonism between India and Asia.Reconstructing the lost forests of Antarctica: the palaeoecology, anatomy and phylogeny of the iconic Glossopteris floraExceptional permineralized biotas - windows into the evolution and functional diversity of terrestrial ecosystems through tim

An Early Permian Glossopteris flora from the Umrer Coalfield, Wardha Basin, Maharashtra, India

A rich and well-preserved Glossopteris-dominated plant fossil assemblage is described from the Barakar Formation of the Makardhokra and Umrer open-cast projects, Umrer Coalfield, Nagpur District, Wardha Basin, Maharashtra, India. The assemblage includes equisetalean axes, cordaitalean leaves (Noeggerathiopsis hislopii), Gangamopteris clarkeana and diverse Glossopteris leaves and a fertile organ assigned to Scutum sp. cf. S. leslii. The flora, although similar to that of the Barakar Formation of the Damodar Basin complex (the reference basin system with respect to the qualitative and quantitative distribution of Indian Permian plant taxa), exhibits unique characteristics and is Artinskian to Kungurian in age. Besides supplementing knowledge of the broader Wardha Basin flora, this is the first systematic documentation of the Glossopteris flora from the Barakar Formation of this basin

(A, B) <i>Centropyxis aculeata</i> var. <i>spinosa</i>, (H20/2), A- apertural view (lobate aperture), B- Dorsal view showing spines on the folded dorsal surface, slide no. 14976. C, D. <i>Centropyxis aculeata</i> (R36/3), C- dorsal view showing broken spines at the margin, D- apertural view shows ventral margin of the aperture connected to the dorsal face by bridges (shown by arrows) slide no.14869. E-L, <i>Centropyxis aculeata</i> (E,F: Q22/3; G,H: P31/4; I,J: R41/2; K,L: N18/2) (E,G,I, K apertural views; F, H, J, L dorsal views showing spines), test covered with sand grains and BDOM from the vicinity, sand grains impart grey colour to the tests, slide nos.(E,F) 14975, (G,H) 14869, (I,J) 14975, (K,L) 14972. Scale bar: 20 μm.

<p>(A, B) <i>Centropyxis aculeata</i> var. <i>spinosa</i>, (H20/2), A- apertural view (lobate aperture), B- Dorsal view showing spines on the folded dorsal surface, slide no. 14976. C, D. <i>Centropyxis aculeata</i> (R36/3), C- dorsal view showing broken spines at the margin, D- apertural view shows ventral margin of the aperture connected to the dorsal face by bridges (shown by arrows) slide no.14869. E-L, <i>Centropyxis aculeata</i> (E,F: Q22/3; G,H: P31/4; I,J: R41/2; K,L: N18/2) (E,G,I, K apertural views; F, H, J, L dorsal views showing spines), test covered with sand grains and BDOM from the vicinity, sand grains impart grey colour to the tests, slide nos.(E,F) 14975, (G,H) 14869, (I,J) 14975, (K,L) 14972. Scale bar: 20 μm.</p

Thecamoebian fossil record of the families Arcellidae and Centropyxidae Thecamoebians preserved in sediments noted by a circle, whereas thecamoebians preserved in amber are noted by a triangle.

<p>The basal part of the figure depicting ecology of the genera <i>Centropyxis</i> and <i>Arcella</i> through time has been modified in the light of this study and other published data. (a) Wolf, 1995; (b) Kumar et al., 2011; (c) Farooqui et al., 2014; (d) Wightmann et al., 1994; (e) Medioli et al., 1990a; (f) Schönborn et al., 1999; (g) Poinar et al., 1993; (h) Schmidt et al., 2004;(i) Waggoner, 1996b; (j) van Hengstum et al., 2007; (k) Porter and Knoll, 2000 and (*) denotes this study. The geological time axis is not to scale. The figure has been modified after van Hengstum et al. 2007 (with written permission from the original author van Hengstum).</p