Karstification in the Cuddapah Sedimentary Basin, Southern India: Implications for Groundwater Resources

The Cuddapah sedimentary basin extends over a significant part of the southern part of Andhra Pradesh State, Southern India. Proterozoic carbonate rocks in the basin are constituted by as three main units- the Vempalle dolomite, the Narji and Koilkuntla limestones. These carbonate rocks are of strategic importance for local communities as they provide the main water source for irrigation and domestic use and they are also intensively quarried for cement production and building stones. It is therefore, of primary importance to assess to which extent these carbonate units are karstified so as to provide recommendations for appropriate land and water resource management. The field investigations carried out indicate that these carbonate units are significantly karstified and karstification has been an ongoing process with several phases under variable climatic conditions. As a result, a significant part of aquifer recharge occurs as point-recharge through swallow-holes and groundwater flow is channelized by conduit networks which emerge at karst springs. Karst development was possibly more active during past humid conditions; however karstification is still an ongoing process under the present semi-arid climate especially in the favorable case where karst drains the runoff issued from upstream quartzitic hills. The karstic nature of these carbonate units need to be integrated in future research and development programmes to avoid practices that may lead to unexpected collapses, reservoir leaks, inaccurate groundwater budgeting, etc

Cultural Production, Reproduction and Subversion of Gender Stereotyping among Pre-Service Science Teachers: Insights from Science Educators

We perceive contestations between science, education and women’s engagement and have raised disruptions in their act of knowing and mobility in science education. This study explored science educators’ views, beliefs and actions of reproduction and subversion of gender stereotyping at a teacher education college in Nigeria. Six science educators were selected based on comprehensive gender information that facilitated conduction of the study. The six educators were purposively selected out of 11 educators who completed and returned the questionnaire. A qualitative approach and case study framed the research using instruments such as questionnaires, interviews, and classroom observation schedules. Thematic analysis and coding were done. Educators consciously and unconsciously reproduced gender stereotypes beliefs and practices. Educators explicitly and implicitly engaged in unequal distribution of cognitive activities amongst pre-service teachers influenced by their practice of cultural norms and patriarchal ideology. The findings revealed multiple oppressions females faced, contradictory science classrooms, and political and democratic classroom space for negotiating and renegotiating discriminatory classroom beliefs, perception and views of educators during science engagements. However, several possibilities such as political advocacy, productive activism and transformative resistance for educators to re-negotiate discriminatory gendered space through constructive gender equality awareness for freedom and intellectual growth in science education could be emancipatory possibilities

Non-invasive detection of divergent metabolic signals in insulin deficiency vs. insulin resistance in vivo

Abstract The type 2 diabetic phenotype results from mixed effects of insulin deficiency and insulin resistance, but the relative contributions of these two distinct factors remain poorly characterized, as do the respective roles of the gluconeogenic organs. The purpose of this study was to investigate localized in vivo metabolic changes in liver and kidneys of contrasting models of diabetes mellitus (DM): streptozotocin (STZ)-treated wild-type Zucker rats (T1DM) and Zucker diabetic fatty (ZDF) rats (T2DM). Intermediary metabolism was probed using hyperpolarized (HP) [1-13C]pyruvate MRI of the liver and kidneys. These data were correlated with gene expression data for key mediators, assessed using rtPCR. Increased HP [1-13C]lactate was detected in both models, in association with elevated gluconeogenesis as reflected by increased expression of phosphoenolpyruvate carboxykinase. In contrast, HP [1-13C]alanine diverged between the two models, increasing in ZDF rats, while decreasing in the STZ-treated rats. The differences in liver alanine paralleled differences in key lipogenic mediators. Thus, HP [1-13C]alanine is a marker that can identify phenotypic differences in kidneys and liver of rats with T1DM vs. T2DM, non-invasively in vivo. This approach could provide a powerful diagnostic tool for characterizing tissue metabolic defects and responses to treatment in diabetic patients with ambiguous systemic manifestations

Detection of localized changes in the metabolism of hyperpolarized gluconeogenic precursors 13 C-lactate and 13 C-pyruvate in kidney and liver.

PurposeThe purpose of this study was to characterize tissue-specific alterations in metabolism of hyperpolarized (HP) gluconeogenic precursors 13 C-lactate and 13 C-pyruvate by rat liver and kidneys under conditions of fasting or insulin-deprived diabetes.MethodsSeven normal rats were studied by MR spectroscopic imaging of both HP 13 C-lactate and 13 C-pyruvate in both normal fed and 24 h fasting states, and seven additional rats were scanned after induction of diabetes by streptozotocin (STZ) with insulin withdrawal. Phosphoenolpyruvate carboxykinase (PEPCK) expression levels were also measured in liver and kidney tissues of the STZ-treated rats.ResultsMultiple sets of significant signal modulations were detected, with graded intensity in general between fasting and diabetic states. An approximate two-fold reduction in the ratio of 13 C-bicarbonate to total 13 C signal was observed in both organs in fasting. The ratio of HP lactate-to-alanine was markedly altered, ranging from a liver-specific 54% increase in fasting, to increases of 69% and 92% in liver and kidney, respectively, in diabetes. Diabetes resulted in a 40% increase in renal lactate signal. STZ resulted in 5.86-fold and 2.73-fold increases in PEPCK expression in liver and kidney, respectively.ConclusionMRI of HP 13 C gluconeogenic precursors may advance diabetes research by clarifying organ-specific roles in abnormal diabetic metabolism. Magn Reson Med 77:1429-1437, 2017. © 2016 International Society for Magnetic Resonance in Medicine

A platform for the discovery of new macrolide antibiotics.

The chemical modification of structurally complex fermentation products, a process known as semisynthesis, has been an important tool in the discovery and manufacture of antibiotics for the treatment of various infectious diseases. However, many of the therapeutics obtained in this way are no longer effective, because bacterial resistance to these compounds has developed. Here we present a practical, fully synthetic route to macrolide antibiotics by the convergent assembly of simple chemical building blocks, enabling the synthesis of diverse structures not accessible by traditional semisynthetic approaches. More than 300 new macrolide antibiotic candidates, as well as the clinical candidate solithromycin, have been synthesized using our convergent approach. Evaluation of these compounds against a panel of pathogenic bacteria revealed that the majority of these structures had antibiotic activity, some efficacious against strains resistant to macrolides in current use. The chemistry we describe here provides a platform for the discovery of new macrolide antibiotics and may also serve as the basis for their manufacture

A minimal information set to enable verifiable theoretical battery research

Batteries are an enabling technology for addressing sustainability through the electrification of various forms of transportation (1) and grid storage. (2) Batteries are truly multi-scale, multi-physics devices, and accordingly various theoretical descriptions exist to understand their behavior (3−5) ranging from atomistic details to techno-economic trends. As we explore advanced battery chemistries (6,7) or previously inaccessible aspects of existing ones, (8−10) new theories are required to drive decisions. (11−13) The decisions are influenced by the limitations of the underlying theory. Advanced theories used to understand battery phenomena are complicated and require substantial effort to reproduce. However, such constraints should not limit the insights from these theories. We can strive to make the theoretical research verifiable such that any battery stakeholder can assess the veracity of new theories, sophisticated simulations or elaborate analyses. We distinguish verifiability, which amounts to “Can I trust the results, conclusions and insights and identify the context where they are relevant?”, from reproducibility, which ensures “Would I get the same results if I followed the same steps?” With this motivation, we propose a checklist to guide future reports of theoretical battery research in Table 1. We hereafter discuss our thoughts leading to this and how it helps to consistently document necessary details while allowing complete freedom for creativity of individual researchers. Given the differences between experimental and theoretical studies, the proposed checklist differs from its experimental counterparts. (14,15) This checklist covers all flavors of theoretical battery research, ranging from atomic/molecular calculations (16−19) to mesoscale (20,21) and continuum-scale interactions, (9,22) and techno-economic analysis. (23,24) Also, as more and more experimental studies analyze raw data, (25) we feel this checklist would be broadly relevant