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Chakrabarti G.,Education Directorate | Shome D.,Jadavpur University | Kumar S.,Jadavpur University | Armstrong-Altrin J.S.,National Autonomous University of Mexico | Sial A.N.,Federal University of Pernambuco
Carbonates and Evaporites | Year: 2011

The marine stromatolitic dolomites of Palaeoproterozoic Vempalle Formation, of Cuddapah Basin, South India show significantly depleted δ 18O (-8.19 to -18.25%) and δ13C (-0.03 to -5.74) values and are consistent with the global Proterozoic data. A comparison of the stable isotope values from major localities of Proterozoic Basins of India has also been attempted in this study. Significantly depleted18O values of Vempalle carbonate samples could not be considered to be postdepositional modifications as there exists an inverse correlation relationship between C and O isotopic values. The Vempalle stromatolitic dolomite is likely to be precipitated in equilibrium with marine waters significantly depleted in oxygen isotopes (-10 to -15% SMOW) with respect to modern sea water. The negative δ13C values of the Vempalle carbonates are likely to be interpreted at the backdrop of global ''icehouse'' as there is an indication of dropstone-like features in the lower part of the Vempalle Formation just 2 km, southwest of the study area. © Springer-Verlag 2011.


Chakrabarti G.,Education Directorate | Shome D.,Jadavpur University | Kumar S.,Jadavpur University | Armstrong-altrin J.S.,National Autonomous University of Mexico | Sial A.N.,Federal University of Pernambuco
Carpathian Journal of Earth and Environmental Sciences | Year: 2013

A shallowing-upward succession of intertidal to subtidal stromatolitic dolomites of the upper Palaeoproterozoic (Orosirian) Vempalle Formation of Cuddapah basin, Peninsular India, is preserved in the Bramhanapalle area (14°25 ́15″ N, 78°12 ́19″ E), near Pulivendla, south India. The δ13Ccarb and δ18OV-PDB values of some selected stromatolitic dolomite samples from this succession vary from +1.25 to -5.74 per mil and from -5.42 to -18.25, respectively. These values are consistent with the global data during the upper Palaeoproterozoic time. A positive to negative δ13C shift in the studied stratigraphic section is indicating (i) a gradual decrease in the biomass productivity during the deposition of Vempalle sediments (ii) the decline of stromatolite type carbonate rocks due to the volcanic activity during the deposition of the Vempalle sediments (iii) an advent of " snowball earth " - like condition in the Indian Peninsular region at the onset of Vempalle sedimentation.


Dixson D.D.,Wayne State University | Worrell F.C.,University of California at Berkeley | Olszewski-Kubilius P.,Northwestern University | Subotnik R.F.,Education Directorate
Annals of the New York Academy of Sciences | Year: 2016

In this study, we examined the contributions of grit, hope, and academic self-efficacy to academic achievement in a sample of 609 academically talented students ranging in age from 10 to 18 years. Our hypothesis was that these variables would predict academic achievement above and beyond the contributions of demographic variables and perceived ability. After establishing the reliability and structural validity of scores for the three constructs in this sample, regression analyses indicated that hope and academic self-efficacy were predictors of perceived ability and that academic self-efficacy was the most robust predictor of academic achievement. Grit was not a meaningful predictor of either perceived ability or academic achievement. We concluded that psychosocial variables can contribute to performance in talented students, but research is needed to establish which psychosocial variables are the most useful. © 2016 New York Academy of Sciences.


Chakrabarti G.,Education Directorate | Shome D.,Jadavpur University | Kumar S.,Jadavpur University | Stephens G.M.,University of Tennessee at Knoxville | Kah L.C.,University of Tennessee at Knoxville
Journal of Asian Earth Sciences | Year: 2014

Sedimentological investigation of the late Paleoproterozoic (Orosirian) Vempalle Formation of the Cuddapah Basin, Dharwar craton, India, reveals three facies association that range from supratidal to deep subtidal. Sedimentary rocks of this succession are dominated by heterolithic carbonate mudstone, intraformational carbonate conglomerate, and a variety of columnar, domal, and stratiform microbialite facies. Deposition occurred in an extensional regime during development of a low-gradient ramp, where the distribution of microbialite facies is distinctly depth-partitioned. A gradual increase in synoptic relief of columnar stromatolites through the section, and the upward transition from stratiform to columnar microbialites, record a prolonged marine transgression with little or no influx of terrigenous detritus. Siliciclastic influx along the northeastern side of the shelf reflects the redistribution of topographic highs concomitant with large scale volcanic activity. Redistribution of topographic highs eventually led to progradation of peritidal facies and shutting down of the carbonate factory. Earthquake-induced ground shaking and voluminous volcanism experienced by this platform point to the reactivation of a deep-seated mantle-plume that resulted in thermal doming of the Dharwar crust prior to the onset of Cuddapah deposition. Isotopic and elemental chemistry of a selection of Vempalle Formation carbonate rocks record elevated Mn2+ and Fe2+ concentrations and depleted carbon isotope values in inner ramp lagoonal facies, relative to more open marine stromatolitic facies. Patterns of isotopic and elemental variation suggest the presence of geochemically distinct water masses-either within the water column or within substrate pore fluids-that resulted from a combination of globally low marine oxygenation and restricted oceanographic circulation in inner ramp environments. These data suggest that, even in the aftermath of Early Paleoproterozoic oxygenation, that ocean chemistry was heterogeneous and strongly affected by local basin conditions. © 2014 Elsevier Ltd.


PubMed | Wayne State University, Northwestern University, University of California at Berkeley and Education Directorate
Type: Journal Article | Journal: Annals of the New York Academy of Sciences | Year: 2016

In this study, we examined the contributions of grit, hope, and academic self-efficacy to academic achievement in a sample of 609 academically talented students ranging in age from 10 to 18 years. Our hypothesis was that these variables would predict academic achievement above and beyond the contributions of demographic variables and perceived ability. After establishing the reliability and structural validity of scores for the three constructs in this sample, regression analyses indicated that hope and academic self-efficacy were predictors of perceived ability and that academic self-efficacy was the most robust predictor of academic achievement. Grit was not a meaningful predictor of either perceived ability or academic achievement. We concluded that psychosocial variables can contribute to performance in talented students, but research is needed to establish which psychosocial variables are the most useful.


PubMed | Eastern Virginia Medical School, Florida State University, Emory University, Executive Office Suites and Education Directorate
Type: Comment | Journal: Families, systems & health : the journal of collaborative family healthcare | Year: 2014

Comments on the article Joint principles: Integrating behavioral health care into the patient-centered medical home (see record 2014-24217-011), presented by the Working Party Group on Integrated Behavioral Healthcare. The American Psychological Association (APA) shares concerns about the lack of reference to behavioral health care in the original 2007 Joint Principles of the Patient-Centered Medical Home for which this new document is intended to supplement but not replace. The decision to support the supplemental Joint Principles was not an easy one for APA, as there is one area of significant concern. That concern is related to the use of the term physician-directed medical practice

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