Quantifying the Predictability of Evolution at the Genomic Level in Lycaeides Butterflies

Stephen Jay Gould, a great scientist and evolutionary biologists, suggested that if we could replay the tape of life, we would not have observed similar course of events because evolution is stochastic and if affected by several events. Since then, the possibility that evolution is repeatable or predictable has been debated. Studies using large-scale evolution experiments, long-term data for individual populations, and controlled experiments in nature, have demonstrated phenotypic and genetic convergence in several taxa. These studies suggest that despite some randomness, predictable evolutionary patterns can emerge on a large temporal and spatial scale. However, a few cases also exist where evolution is unpredictable and stochastic. One way to understand evolutionary predictability better can be to have quantitative estimates of predictability at different heirarchical levels (mutations, genetic, phenotypic). This can help better understand if evolution is predictable and the extent to which it is predictable. My dissertation uses Lycaeides butterflies to identify and quantify evolutionary predictability in different contexts such as on a geographic scale, temporal scale and genomic scale. I accomplished this by sequencing and annotating the genomes of these butterflies across a vast geographic range and on a temporal scale and by comparing natural and experimental populations. My results show that different mechanisms can assist evolution of organisms to adapt to novel environmental challenges, and that the evolutionary changes can be somewhat predictable. Through this work I demonstrate three main findings: first, quantitative estimates of evolutionary predictability indicate that degree of predictability is variable and is highly context-dependent. Second, we can predict evolutionary patterns on a spatial as well as temporal scale, and can predict patterns in nature by controlled laboratory experiments. Additionally, genomic changes underlying repeatability vary across the genome. Lastly, the approach of quantifying predictability can help us better understand the mechanisms which drive evolution and how organisms will evolve in response to similar environmental pressures. These results suggest that evolution can be constrained and if we actually replay the tape of life, we could see a considerably similar outcome in biodiversity compared to what Gould predicted

The Role of Multiple Large Shareholders in Dividend Payouts: Evidence from India

This study examines the impact of multiple large shareholders (MLS) on a firm’s dividend payouts in a low-investor protection regime, India, where minority shareholders’ expropriation concerns are severe and firms have an incentive to build a capital market reputation. Therefore, we purport for the prevalence of the substitution hypothesis, whereby MLS cooperate in paying larger dividends to assuage expropriation concerns for reputation-building. The empirical analysis using non-financial firms with MLS listed on NIFTY 500 from 2009 to 2019 yields that both the controlling owner and MLS positively influence dividend payout intensity. Additional analyses also demonstrate that the positive effect of MLS is prominent in growing firms that undertake equity issuances and firms with lower board independence. We also find that firms make relatively lower payouts when an institutional investor is the second largest shareholder. Further, it is shown that MLS engage in greater dividend smoothing. Lastly, it is observed that dividends are more valuable for firms with higher MLS ownership. Altogether, these findings support the substitution hypothesis

Exploiting activated esters in novel chemoselective amide formation reactions

Detailed within this thesis are the synthetic studies performed on the preparation of lipase catalysed activated esters and their subsequent use in the synthesis of pharmaceutically relevant amides. It also includes the application of activated esters in chemoselective amide formation reactions. The introduction summarizes the significance and use of activating agents in lipase catalysed reactions over the classical methods of amides synthesis. Additionally, a detailed review on some currently available chemoselective N-acylating agents along with their applications is also mentioned. A separate chapter is given to the application of related amides in the designing of biological probes to ultimately detect enzymes which are over-expressed in disease. The discussion begins with the lipase-catalysed synthesis of acetone oxime activated esters and their role in the one-pot synthesis of acetanilides. Further discussion continues with the synthesis of activated esters from ethylene glycol and haloalcohols. The use of a lipase in the synthesis of glycol esters prevented the formation of dimers which indicates its potential usefulness in the future. Unfortunately, these activated esters could not be applied to a synthesis of amides in the same manner as acetone oxime. Thereafter the section focuses on the investigation and synthesis a novel chemoselective N-acylating agent and its subsequent applications in the synthesis of pharmaceutically important amides, in particular, those involving chemoselective reactions between anilines and N-substituted anilines. Additionally, the chemoselective agent was also used in preparation of pharmaceutically important compounds. To round off the thesis the application of one of the target compounds-benzanilide-was used to develop and synthesise a novel biological probe and to scope out its potential for application in the detection of enzyme-controlled disease. The preliminary utility of the probe was demonstrated using HPLC and NMR. The thesis concludes with the experimental encompassing experimental details, spectroscopic and analytical analysis of all the compounds described

BIOLOGICAL EVALUATION, QSAR AND MOLECULAR MODELING STUDIES OF 2,4-DICHLOROBENZOIC ACID DERIVATIVES AS ANTIMICROBIAL AGENTS

Objective: The aim of this study was to evaluate 2,4-dichlorobenzoic acid derivatives as antimicrobial agents through in vitro, QSAR and molecular docking studies. Methods: The compounds were subjected to in vitro antimicrobial screening by test tube dilution method and the structural characteristics governing the antimicrobial potential were studied using QSAR methodology. These compounds were also screened for docking simulation to find out binding confirmation of reported compounds with PDB 1aj0 and 5fsa using AutoDock tools and discovery studio. Results: The antimicrobial evaluation data indicated that compounds 13 and 18 were found to be the most effective against all the bacterial strains and Aspergillus niger while compounds 1 and 14 exhibited more antifungal potential against Candida albicans. QSAR studies confirmed the role of molar refractivity and Balaban index (J) as controlling parameters for antimicrobial potential. Molecular modeling study revealed that compounds interact with the active site of PDB by hydrophobic, hydrogen bonding, and Van der Wall interactions. Conclusion: These test compounds were identified as potent candidates for the control of microbial strains tested, and structural relationship with activity may provide valuable information for further design and synthesis of compounds with antimicrobial potential

Photoluminescence, photoredox properties and crystal structures of rhenium(v)-benzylidyne complex with phosphine ligands.

Several rhenium(v)-benzylidyne complexes [Re(CR)(pdpp)2Cl]+[R=C6H2Me3-2,4,6,pdpp= o-phenylenebis(diphenylphosphine)], [Re(CR)L2(CO)(H2O)Cl]+ [L=PPh3, P(C6H4OMe-p)3 or PMe2Ph] and trans-[Re(CR)(dppe)(CO)2Cl]+ [dppe= 1,2-bis(diphenylphosphino)ethane] have been prepared. The structures of trans-Re(CR)(pdpp)2Cl]ClO4.CHCl3.0.25MeOH and [Re(CR)(PPh3)2 (CO)(H2O)Cl]ClO4. 1.5MeOH have been determined by X-ray analyses. The Re≡C distances are 1.802(5) and 1.784(8) Å respectively. In acetonitrile and dichloromethane the complexes show intense absorption bands at 318-330 nm and weak ones at 405-450 nm, the latter being tentatively assigned to dxy → dn* (dxz,dyz) transitions. Photoexcitation in the solution, solid or glassy state gives intense orange to red emissions, and the emitting states are tentatively assigned to 3[(dxy)1](dπ*)1]. The variation in non-radiative decay rate constants for the emissions of the rhenium(v)-benzylidyne complexes are consistent with a predication from the energy-gap law. The excited states are better oxidants and reductants than the grounds states. The values of E°(Rev*-ReIV ) and E° (ReVI-ReV*) in acetonitrile have been determined using spectroscopic and electrochemical data as well as by Stern-Volmer  quenching experiments

Linguistic Markers of Influence in Informal Interactions

There has been a long standing interest in understanding `Social Influence' both in Social Sciences and in Computational Linguistics. In this paper, we present a novel approach to study and measure interpersonal influence in daily interactions. Motivated by the basic principles of influence, we attempt to identify indicative linguistic features of the posts in an online knitting community. We present the scheme used to operationalize and label the posts with indicator features. Experiments with the identified features show an improvement in the classification accuracy of influence by 3.15%. Our results illustrate the important correlation between the characteristics of the language and its potential to influence others.Comment: 10 pages, Accepted in NLP+CSS workshop for ACL (Association for Computational Linguistics) 201

Health communication for antimicrobial resistance and stewardship in the Makana Local Municipality, South Africa

Access restricted. Expected release date 2025.Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 202