7 research outputs found
Revati Laul: The anatomy of hate
No full textOne massacre. Three lives. In a non-fictional account of an event etched deep in the annals of contemporary India, independent journalist and filmmaker Revati Laul has written a compelling account of the 2002 anti-Muslim violence in Gujarat. With the burning of the Sabarmati Express in Godhra on 26 February 2002 as the backdrop, Footnote1 the author stitches together the lives of three protagonists, who may have been victims of their circumstances but were in varying degrees primarily the perpetrators of the violence
Neural correlates of acute-induced stress and decision-making under risk: an fMRI study
No full textMany situations in daily life require making risky decisions under stressful conditions. In the
current behavioral literature, the effects of stress on risky decision-making are inconsistent,
and there is limited research investigating post-stress risky decisions from a neural
perspective. Identifying neural correlates of post-stress risky decision-making might help to
improve the targeted behavioral interventions for risk adjustment. Furthermore, the
investigation of post-stress risky decisions from a neuroscientific perspective might shed
light on underlying neural/cognitive mechanisms that can moderate the impact of stress on
decision-making and offer insights unattainable through behavioral methods alone.
Thus, in this dissertation, functional Magnetic Resonance Imaging (fMRI) was employed to
assess the neural correlates of stress as well as post-stress risky decision-making. The study
consisted of four experimental blocks: stress, post-stress decision-making, control, and post
control decision-making. The design was within-subject and all participants were subjected
to stress and control conditions in a counterbalanced order. Both stress and control
conditions were followed by a “decision-making under risk” task directly after the stress
exposure in a single fMRI session with a concurrent Electrodermal Activity (EDA)
measurement to confirm the stress manipulation. Stress was induced by asking participants
to solve mental arithmetic tasks under time pressure & social-evaluative threat while
receiving negative feedback. During the decision-making task, participants chose between a
safe and a risky option (binary lottery task) with monetary incentives and known
probabilities of winning.
Self-reported stress levels and EDA data confirmed that the stress induction was successfully
implemented. Participants took less risky decisions post-stress than post-control. An fMRI
contrast analysis revealed that the right fronto-opercular and the left anterior part of the
dorsolateral prefrontal cortex (dlPFC; an area critical for executive functioning and cognitive
control) exhibited significantly lower activation during decisions post-stress than decisions
post-control.
The results indicate that decisions taken immediately after exposure to the acute stressor
are associated with reduced activation in the regions of the dlPFC, possibly leading to less
deliberate and less risky decision-making post-stress. Interventions to increase dlPFC
activation might be suitable to improve the quality of decision-making post-stress, alleviating
the effects of stress
Neural Correlates of Acute Induced Stress and Decision-making under Risk: an fMRI study
No full textThe current pre-registration is of a functional Magnetic Resonance Imaging (fMRI) study that aims to investigate the neural correlates of acute induced stress and decision-making under risk.
The rationale of the study is multi-folded. Firstly, the aim is to simultaneously assess both stress and risky decision-making from a neuroscientific perspective with the help of fMRI. Specifically, the impact of acute induced stress on decision-making under risk will be evaluated by examining brain activation patterns. Secondly, the current study aims to contribute to the development of a neurophysiological model of stress processing in humans with the help of functional neuroimaging. Finally, the modulators of stress during decision-making will be assessed from a neuroscientific perspective.
For this purpose, a novel within-subject experimental design is proposed wherein stress induction and decision-making tasks will take place in an MRI scanner environment with a minimal stress to task latency.
The primary goal of the study is to investigate if whole brain activation during decision making under risk differs between the pre- and post-stress conditions.unknownothe
Acetate ion and its interesting solvation shell structure and dynamics
No full text© 2018 Author(s). The asymmetric stretch of the carboxylate group located near 1560 cm-1 in solutions of sodium acetate in water and 6M sodium chloride was investigated by linear and two-dimensional infrared spectroscopies. The linear IR spectra showed that the carboxylate asymmetric stretch central frequency and bandwidth are not significantly perturbed by the presence of a large amount of sodium chloride. Similarly, the frequency-frequency autocorrelation functions extracted from the time evolution of two-dimensional infrared spectra revealed a dynamical component having a picosecond time constant which is also not affected by the presence of high salt concentrations. A comparative study on the asymmetric stretch of the azide ion showed that the lack of change in the vibrational spectroscopy of the ion in the presence of large concentration of sodium chloride is particular to the acetate ion. Ab initio molecular dynamics simulations and a frequency map confirmed our experimental observations and linked the observed vibrational phenomenon to the hydrogen bond structure and dynamics of the acetate first solvation shell, which is governed by the thermal rotation of its methyl group (- CH3)
Effect of point mutations on the toxicity of shiga toxin A1 subunit
No full textShiga toxin (Stx)-producing Escherichia coli (STEC) infections can lead to life- threatening complications, including hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS), which is the most common cause of acute renal failure in children in the United States. Previous studies have shown that STEC strains producing Stx2 are more commonly associated with HUS than those producing Stx1. Our lab has shown that the A1 subunit of Stx2 (Stx2A1) is more active than the A1 subunit of Stx1 (Stx1A1). The purpose of my study is to understand the basis for the higher toxicity of Stx2A1 by interchanging its residues with Stx1A1. Initially, the activity of wild type Stx1A1 and Stx2A1 was compared in yeast in order to establish a base line to study the effect of new mutations. We used site directed mutagenesis to exchange residues that contribute to surface charge differences between Stx1A1 and Stx2A1. Point mutations were made by interchanging Stx2A1 residues with Stx1A1 residues. If these residues contributed to the higher toxicity of Stx2A1 its toxicity would be reduced and the toxicity of Stx1A1 would be increased. The plasmids containing the mutants were transformed into yeast. The transformants were then grown in dextrose in a double overnight culture and expression was induced in galactose. The depurination activity and cytotoxicity of the point mutants was examined at different time points post-induction. Only small differences were observed between the single point mutants and the wild type toxins in both depurination activity and cytotoxicity. In contrast, several multiple mutations increased the toxicity of Stx1A1. While double mutations did not reduce the toxicity of Stx2A1 possibly due to its higher toxicity, quadruple and quintuple mutations reduced the toxicity of Stx2.M.S.Includes bibliographical reference
The role of pregnancy associated plasma protein-A in triple negative breast cancer : a promising target for achieving clinical benefits
No full textPregnancy associated plasma protein-A (PAPP-A) plays an integral role in breast cancer (BC), especially triple negative breast cancer (TNBC). This subtype accounts for the most aggressive BC, possesses high tumor heterogeneity, is least responsive to standard treatments and has the poorest clinical outcomes. There is a critical need to address the lack of effective targeted therapeutic options available. PAPP-A is a protein that is highly elevated during pregnancy. Frequently, higher PAPP-A expression is detected in tumors than in healthy tissues. The increase in expression coincides with increased rates of aggressive cancers. In BC, PAPP-A has been demonstrated to play a role in tumor initiation, progression, metastasis including epithelial-mesenchymal transition (EMT), as well as acting as a biomarker for predicting patient outcomes. In this review, we present the role of PAPP-A, with specific focus on TNBC. The structure and function of PAPP-A, belonging to the pappalysin subfamily, and its proteolytic activity are assessed. We highlight the link of BC and PAPP-A with respect to the IGFBP/IGF axis, EMT, the window of susceptibility and the impact of pregnancy. Importantly, the relevance of PAPP-A as a TNBC clinical marker is reviewed and its influence on immune-related pathways are explored. The relationship and mechanisms involving PAPP-A reveal the potential for more treatment options that can lead to successful immunotherapeutic targets and the ability to assist with better predicting clinical outcomes in TNBC. © The Author(s) 2024
Dynamic friction behavior of ultrananocrystalline diamond films: A depth-resolved chemical phase analysis
No full textInvestigation of dynamic changes in friction behavior of ultrananocrystalline diamond (UNCD) films is a complex mainly because of the rapid change in chemical composition at the sliding interfaces. To address this issue, for the first time, we report chemical phase analysis of transferfilm using the depth-resolved X-ray photoelectron spectroscopy (XPS) technique. The friction coefficient of the UNCD films was high during the initial run-in regime, but it gradually decreased to an ultralow value after longer sliding cycles at the ambient atmospheric tribo-condition. Depth-resolved XPS analysis showed a higher sp(3)/sp(2) carbon ratio during the initial run-in regime. This ratio decreased with increasing sliding cycles and consequently the friction coefficient decreased. However, a higher value of the friction coefficient throughout the run-in regime persisted at the high-vacuum tribo-condition. In this case, the sp(3)/sp(2) carbon ratio inside the transferfilm was quite high and no considerable changes were observed in the depth-resolved XPS analysis. This investigation confirmed that the dynamic friction behavior in UNCD films was manipulated by the sp(3)/sp(2) carbon ratio inside the transferfilm which showed tribo-atmospheric dependence.Kumar, N (reprint author), Indira Gandhi Ctr Atom Res, Mat Sci Grp, Kalpakkam 603102, Tamil Nadu, India.
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