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Molecular insights into the adsorption and self-assembly of charged copolypeptides on Silica
No full textThis study explores the molecular mechanisms driving peptide-silica interactions, focusing on the adsorption and self-assembly of lysine-leucine copolypeptides and their influence on lysozyme adsorption. Using long-timescale molecular dynamics simulations, we examine how charge density and sequence blockiness affect peptide behavior on negatively charged silica surfaces. Poly-lysine homopolypeptides show strong electrostatic interactions, leading to full surface adsorption, while neutral poly-leucine peptides weakly adsorb and orient perpendicularly. Copolypeptides with a fixed charge density of 0.5 exhibit blockiness-dependent adsorption and structural organization. Increased blockiness promotes independent peptide behavior and varied self-assembly. Modified silica surfaces functionalized with these peptides enhance lysozyme stability and reduce conformational disruption compared to bare silica. Our findings demonstrate that peptide sequence design can modulate surface interactions and protein adsorption. This work provides valuable insights into engineering amphiphilic polypeptides for surface functionalization, with potential applications in biomaterials, biosensing, and therapeutic delivery systems
Selective and tunable ion transport through the angstrom size fluidic channels of van der waal materials: from iontronics to energy generation
No full text
Air Pollution to Atmospheric Warming: Effects of Increasing Anthropogenic Aerosols on South Asia’s Climate
No full textSurface cooling by aerosols partially offsets GHG warming. Understanding and evolution of aerosol forcing over a global aerosol hotspot, South Asia, is crucial for regional and global climate. For the first time, utilizing multi-source data from satellites (Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), Ozone Monitoring Instrument (OMI), and Clouds and the Earth's Radiant Energy System (CERES)), and models (Modern-Era Retrospective Analysis for Research and Applications-2 (MERRA-2) and Copernicus Atmospheric Monitoring Service (CAMS)), climatology and trends in aerosols and radiative effects on seasonal and annual scales are derived and quantified. Aerosol optical depth (AOD) exhibits significant spatiotemporal variability across South Asia. Annual mean AOD is mostly > 0.3 with AOD over Indo-Gangetic Plain (IGP) being > 0.5. AOD shows a significant increasing trend (≥ 0.01 yr‒1; ≥ 50%) during 2005–2019 across India except over northwest India. Annual trend in AOD is driven by post-monsoon and winter trends when anthropogenic aerosol emissions dominate, and by small- and medium-size AODs. AOD trends are negative over western India during pre-monsoon and monsoon which is dominated by coarse mode particles (dust, large-size AOD). On an annual scale, sulfate, black carbon, and organic carbon AODs have increased, whereas dust AOD does not exhibit any significant trend, confirming that increase in AOD is due to the increase in fine-mode aerosols dominantly emitted by anthropogenic activities, corroborated by the increasing trend of anthropogenic AOD. Trends in single scattering albedo are quite small and not statistically significant. Aerosol direct radiative effect (DRE) at the surface (DRESFC) decreases by ≤ − 1 Wm‒2 yr‒1. Aerosol-induced heating rate (HR) in the atmosphere exhibits an increasing trend (~ 0.01 K day‒1 yr‒1). Increasing trends of AOD, DRESFC (magnitude), and HR are higher over central and south India. Winter air quality across the IGP could worsen as a result of increases in anthropogenic aerosols amplified by declining trends in winds and rising relative humidity. Since 2005, there has been a robust and persistent evidence of increasing radiative influence of anthropogenic aerosols on climate (surface cooling and atmospheric warming) over South Asia. In light of the projected global warming, this additional aerosol-induced atmospheric warming across South Asia would be critical
On the refined Koblitz conjecture
No full textLet p be a prime, E be a non-CM elliptic curve over Q, and Np be the number of points of E over Fp. Given t∈N, we are concerned with the asymptotic formula for the set of primes for which Np/t is a prime. The asymptotic constant was first conjectured by Koblitz for t=1 and the conjecture was later refined by Zywina. Assuming an elliptic analogue of the Elliott-Halberstam conjecture and a conjecture on the average order of growth of Np, this paper arrives at the conjectured constant, using techniques from classical analytic number theory. This is the first result where the conjectured constant is conditionally determined
The Cost and Complexity of Minimizing Envy in House Allocation
No full textWe study almost envy-freeness in house allocation, where m houses are to be allocated among n agents so that every agent receives exactly one house. An envy-free allocation need not exist, and therefore we may have to settle for relaxations. We study different aggregate measures of envy as markers of fairness. In particular, we define the amount of envy experienced by an agent a w.r.t. an allocation to be the number of agents that agent a envies under that allocation. We quantify the envy generated by an allocation using three different metrics: 1) the number of agents who are envious; 2) the maximum amount of envy experienced by any agent; and 3) the total amount of envy experienced by all agents, and look for allocations that minimize one of the three metrics. We prove a host of algorithmic and hardness results. We also suggest practical approaches for these problems via integer linear program (ILP) formulations and report the findings of our experimental evaluation of ILPs. Finally, we study the price of fairness, which quantifies the loss of welfare we must suffer due to the fairness requirements, and present tight bounds as well as algorithms that simultaneously optimize both welfare and fairness
