Kinetic Models of Wealth Distribution Having Extreme Inequality: Numerical Study of Their Stability Against Random Exchanges

In view of some persistent recent reports on a singular kind of growth of the world wealth inequality, where a finite (often handful) number of people tend to possess often more than the wealth of the planet's 50\% population, we explore here if the kinetic exchange models of the market can ever capture such features where a significant fraction of wealth can concentrate in the hands of a countable few when the market size $N$ tends to infinity. One already existing example of such a kinetic exchange model is the Chakraborti or Yard-Sale model, where (in absence of tax redistribution etc) the entire wealth condenses in the hand of one (for any $N$), and the market dynamics stops. With tax redistribution etc, its steady state dynamics have been shown to have remarkable applicability in many cases of our extremely unequal world. We show here, another kinetic exchange model (called here the Banerjee model) has intriguing intrinsic dynamics, by which only ten rich traders or agents possess about 99.98\% of the total wealth in the steady state (without any tax etc like external manipulation) for any large value of $N$. We will discuss in some detail the statistical features of this model using Monte Carlo simulations. We will also show, if the traders each have a non-vanishing probability $f$ of following random exchanges, then these condensations of wealth (100\% in the hand of one agent in the Chakraborti model, or about 99.98\% in the hands ten agents in the Banerjee model) disappear in the large $N$ limit. We will also see that due to the built-in possibility of random exchange dynamics in the earlier proposed Goswami-Sen model, where the exchange probability decreases with an inverse power of the wealth difference of the pair of traders, one did not see any wealth condensation phenomena.Comment: 10 pages and 9 figures; Invited paper in the Special Issue on "Statistical Physics and Its Applications in Economics and Social Sciences", in Entrop

Sandpile Universality in Social Inequality: Gini and Kolkata Measures

Social inequalities are ubiquitous and also evolve towards some universal limit. Here we review extensively the values of inequality measures, namely the Gini ($g$) and Kolkata ($k$) indices, the two generic inequality indices, from data analysis of different social sectors. The kolkata index $k$ gives the fraction of `wealth' possessed by $(1 - k)$ fraction of `people'. We show that the values of both these indices approach each other (to $g = k \simeq 0.87$, starting from $g = 0, k = 0.5$ for equality) as the competitions grow in various social institutions like markets, movies, elections, universities, prize winning, battle fields, sports (Olympics) and etc. under unrestricted competitions (no social welfare or support mechanism). We propose to view this coincidence of inequality indices as a generalized version of the (more than a) century old 80-20 law of Pareto ($k$ = 0.80). Furthermore, this coincidence of the inequality indices noted here is very similar to the ones seen just prior to the arrival of the self-organized critical (SOC) state in well studied self-tuned physical systems like sand-piles. The observations here, therefore, stand as a quantitative support towards viewing interacting socio-economic systems in the framework of SOC, an idea conjectured for years.Comment: 29 pages, 15 figures and 13 tables, Invitation to Publish in Special Issue "Entropy-Based Applications in Sociophysics" of 'Entropy' Journa

Initial nitrogen enrichment conditions determines variations in nitrogen substrate utilization by heterotrophic bacterial isolates

Background The nitrogen (N) cycle consists of complex microbe-mediated transformations driven by a variety of factors, including diversity and concentrations of N compounds. In this study, we examined taxonomic diversity and N substrate utilization by heterotrophic bacteria isolated from streams under complex and simple N-enrichment conditions. Results Diversity estimates differed among isolates from the enrichments, but no significant composition were detected. Substrate utilization and substrate range of bacterial assemblages differed within and among enrichments types, and not simply between simple and complex N-enrichments. Conclusions N substrate use patterns differed between isolates from some complex and simple N-enrichments while others were unexpectedly similar. Taxonomic composition of isolates did not differ among enrichments and was unrelated to N use suggesting strong functional redundancy. Ultimately, our results imply that the available N pool influences physiology and selects for bacteria with various abilities that are unrelated to their taxonomic affiliation. Electronic supplementary material The online version of this article (doi:10.1186/s12866-017-0993-7) contains supplementary material, which is available to authorized users

Enhanced Piezoresponse and Nonlinear Optical Properties of Fluorinated Self-Assembled Peptide Nanotubes

Self-assembled L,L-diphenylalanine (FF) nanostructures offer an attractive platform for photonics and nonlinear optics. The nonlinear optical (NLO) coefficients of FF nanotubes depend on the diameter of the tube [S. Khanra et al. Phys. Chem. Chem. Phys. 19(4), 3084-3093 (2017)]. To further enhance the NLO properties of FF, we search for structural modifications. Here, we report on the synthesis of fluorinated FF dipeptides by replacing one ortho-hydrogen atom in each of the phenyl groups of FF by a fluorine atom. Density-functional theoretical calculations yield insights into minimum energy conformers of fluorinated FF (Fl-FF). Fl-FF self-assembles akin to FF into micron-length tubes. The effects of fluorination are evaluated on the piezoelectric response and nonlinear optical properties. The piezoelectric d15 coefficient of Fl-FF is found to be more than 10 times higher than that of FF nanotubes, and the intensity of second harmonic generation (SHG) polarimetry from individual Fl-FF nanotubes is more than 20 times that of individual FF nanotubes. Furthermore, we obtain SHG images to compare the intensities of FF and Fl-FF tubes. This work demonstrates the potential of fluorine substitution in other self-assembled biomimetic peptides for enhancing nonlinear optical response and piezoelectricity

Comparison of the Effect of Pretreatment with Cisatracurium and Rocuronium on Succinylcholine Induced Fasciculation for Patients undergoing Surgery under General Anaesthesia: A Randomised Clinical Study

Introduction: Succinylcholine is the best agent for providing ideal intubating condition. Muscle fasciculation is common after succinylcholine administration and causes postoperative myalgia. Pretreatment with non depolarising muscle relaxant decreases fasciculation and myalgia after succinylcholine administration. Aim: To compare the efficacy between cisatracurium and rocuronium in preventing succinylcholine induced fasciculation in patients undergoing general anaesthesia and determining association between fasciculation and myalgia after succinylcholine use. Materials and Methods: The present study was a hospital-based, randomised, double-blinded clinical study conducted from January 2020 to July 2020. The study included 64 patients of American Society of Anaesthesiologists (ASA) grade I and II undergoing surgery under general anaesthesia which were randomly allocated in two groups. Group 1 (N=32) received intravenous (i.v.) cisatracurium (0.01 mg/kg) and group 2 (N=32) received i.v. rocuronium (0.06 mg/kg) as precurarising agent, three minutes before i.v. succinylcholine (1.5 mg/kg) administration. Incidence and intensity of fasciculation after succinylcholine injection was observed using a 4 point scale. Haemodynamic parameters were compared by measuring Mean Arterial Pressure (MAP) and Heart Rate (HR) before and after intubation. Patients were followed-up in Postanesthesia Care Unit (PACU) on Postoperative Day 1 (POD1) for myalgia. Observations in two groups were analysed using standard statistical test. Results: Fasciculation was significantly lower in group 2 (mean 0.2187±0.4200) than group 1 (mean 1.125±0.833, p-value <0.001). A significant association was found between fasciculation after succinylcholine injection and postoperative myalgia (p-value=0.007). Group 2 had less incidence of myalgia than group 1. However, the difference was not statistically significant. Conclusion: Rocuronium was more efficacious than cisatracurium in preventing succinylcholine induced fasciculation and rocuronium was more effective in preventing succinylcholine-related postoperative myalgia

Transcriptomic and functional analysis of the Anopheles gambiae salivary gland in relation to blood feeding

<p>Abstract</p> <p>Background</p> <p>The <it>Anopheles gambiae </it>salivary glands play a major role in malaria transmission and express a variety of bioactive components that facilitate blood-feeding by preventing platelet aggregation, blood clotting, vasodilatation, and inflammatory and other reactions at the probing site on the vertebrate host.</p> <p>Results</p> <p>We have performed a global transcriptome analysis of the <it>A. gambiae </it>salivary gland response to blood-feeding, to identify candidate genes that are involved in hematophagy. A total of 4,978 genes were found to be transcribed in this tissue. A comparison of salivary gland transcriptomes prior to and after blood-feeding identified 52 and 41 transcripts that were significantly up-regulated and down-regulated, respectively. Ten genes were further selected to assess their role in the blood-feeding process using RNAi-mediated gene silencing methodology. Depletion of the salivary gland genes encoding <it>D7L2</it>, <it>anophelin</it>, <it>peroxidase</it>, the <it>SG2 precursor</it>, and a <it>5'nucleotidase </it>gene significantly increased probing time of <it>A. gambiae </it>mosquitoes and thereby their capacity to blood-feed.</p> <p>Conclusions</p> <p>The salivary gland transcriptome comprises approximately 38% of the total mosquito transcriptome and a small proportion of it is dynamically changing already at two hours in response to blood feeding. A better understanding of the salivary gland transcriptome and its function can contribute to the development of pathogen transmission control strategies and the identification of medically relevant bioactive compounds.</p

Utilization of different forms of nitrogen by heterotrophic bacteria under varying organic carbon concentrations: From isolates to communities

It is important to understand fate of nutrients like nitrogen, in streams given that anthropogenic activity, such as agriculture, have increased inputs of biologically reactive nitrogen to the environment leading to deterioration of stream health and eutrophication. Bacteria play a crucial role in the driving essential biogeochemical transformations. The purpose of this research was to improve our understanding of organic and inorganic nitrogen utilization by bacterial isolates and complex bacterial communities. Role of bacterial diversity in resource utilization is mostly neglected in biogeochemical models. Identification of bacteria based on molecular methods, like 16S rDNA sequencing, yield a wealth of information related to prokaryotic diversity and its importance in driving essential biogeochemical cycles. In this research utilization of organic and inorganic forms of nitrogen by stream heterotrophic bacterial isolates were examined. Our results reveal differences in bacterial resource utilization not as a function of the different taxa involved but of the enrichments the isolates were obtained from, as immediate environment dictate bacterial response to different nutrients and exerts a selection pressure. Carbon availability also influences nitrogen dynamics. To examine the impact of carbon on bacterial uptake of organic and inorganic nitrogen, bacterial abundance and community composition were examined in controlled, laboratory microcosms. There was a strong influence of carbon availability on bacterial nitrogen utilization, with preferential uptake of organic forms under low carbon concentrations. Carbon and nitrogen treatments likely drove changes in bacterial community composition that, in turn, affected rates of nitrogen utilization under various carbon concentrations. Metabolic functions, such as particular biogeochemical reactions are catalyzed by microbial extracellular enzymes, which are likely linked to the constituting taxa in a given microbial community. This study tracked temporal patterns of bacterial community structure and potential microbial enzyme activities in response to seasonal changes in stream organic matter pool. Differences in enzyme activities were highly correlated to nutrient (carbon and nitrogen) availability while differences in bacterial community structure were mostly driven by environmental conditions. However, the absence of link between bacterial community structure and potential enzyme activity is indicative of functional redundancy within microbial communities