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A simple measurement scheme is proposed to reconstruct the geometry of an axisymmetric void propagating through a conducting liquid using a pair of parallel wire conductivity probes. An experimental study allows for obtaining the time variation of the resistance of the film surrounding the void. Analytical modeling and numerical simulation has been adopted to correlate the resistance between the wire electrodes and the film thickness. Finally, the shape of the void can be estimated by combining the predicted resistance–film thickness relationship and the measured time variation of resistance. For validation, this scheme has been used to reconstruct the shape of a rising Taylor bubble. There is a fair match between the reconstructed shape of the bubble and its photographic image. The probable errors in the measurement scheme have been discussed and assessed mathematically. [ABSTRACT FROM AUTHOR]

In this paper, multidimensional dissipative quantum dynamics is studied within a system–bath approach in the Markovian regime using a model Lindblad operator. We report on the implementation of a Monte Carlo wave packet algorithm in the Heidelberg version of the Multi-Configuration Time-Dependent Hartree (MCTDH) program package, which is henceforth extended to treat stochastic dissipative dynamics. The Lindblad operator is represented as a sum of products of one-dimensional operators. The new form of the operator is not restricted to the MCTDH formalism and could be used with other multidimensional quantum dynamical methods. As a benchmark system, a two-dimensional coupled oscillators model representing the internal stretch and the surface–molecule distance in the O2/Pt(111) system coupled to a Markovian bath of electron–hole-pairs is used. The simulations reveal the interplay between coherent intramolecular coupling due to anharmonic terms in the potential and incoherent relaxation due to coupling to an environment. It is found that thermalization of the system can be approximately achieved when the intramolecular coupling is weak. [ABSTRACT FROM AUTHOR]

The solution of complex problems by the collective action of simple agents in both biologically evolved and synthetically engineered systems involves cooperative action. Understanding the resulting emergent solutions requires integrating across the organismal behavior of many individuals. Here, we investigate an ecologically relevant collective task in black carpenter ants Camponotus pennsylvanicus: excavation of a soft, erodible confining corral. These ants show a transition from individual exploratory excavation at random locations to spatially localized collective exploitative excavation and escape from the corral. Agent- based simulations and a minimal continuum theory that coarse-grains over individual actions and considers their integrated influence on the environment leads to the emergence of an effective phase space of behaviors, characterized in terms of excavation strength and cooperation intensity. To test the theory over the range of both observed and predicted behaviors, we use custom-built robots (RAnts) that respond to stimuli to characterize the phase space of emergence (and failure) of cooperative excavation. Tuning the amount of cooperation between RAnts, allows us to vary the efficiency of excavation and synthetically generate the entire range of macroscopic phases predicted by our theory. Overall, our approach shows how the cooperative completion of tasks can arise from simple rules that involve the interaction of agents with a dynamically changing environment that serves as both an enabler and a modulator of behavior. [ABSTRACT FROM AUTHOR]

The workability of beyond Born-Oppenheimer theory to construct diabatic potential energy surfaces (PESs) of a charge transfer atom-diatom collision process has been explored by performing scattering calculations to extract accurate integral cross sections (ICSs) and rate constants for comparison with most recent experimental quantities. We calculate non-adiabatic coupling terms among the lowest three singlet states of H3+ system (1¹A', 2¹A', and 3¹A') using MRCI level of calculation and solve the adiabatic-diabatic transformation equation to formulate the diabatic Hamiltonian matrix of the same process [S. Mukherjee et al., J. Chem. Phys. 141, 204306 (2014)] for the entire region of nuclear configuration space. The nonadiabatic effects in the D+ +H2 reaction has been studied by implementing the coupled 3D time-dependent wave packet formalism in hyperspherical coordinates [S. Adhikari and A. J. C. Varandas, Comput. Phys. Commun. 184, 270 (2013)] with zero and non-zero total angular momentum (J) on such newly constructed accurate (ab initio) diabatic PESs of H3+. We have depicted the convergence profiles of reaction probabilities for the reactive non-charge transfer, non-reactive charge transfer, and reactive charge transfer processes for different collisional energies with respect to the helicity (K) and total angular momentum (J) quantum numbers. Finally, total and state-to-state ICSs are calculated as a function of collision energy for the initial rovibrational state (v = 0, j = 0) of the H2 molecule, and consequently, those quantities are compared with previous theoretical and experimental results. [ABSTRACT FROM AUTHOR]

Abstract Background To report atypical features on Spectral domain optical coherence tomography (SD-OCT) in a case of non-familial pure adult nanophthalmos. Case presentation A 39 year old male hyperope was found to have biometric and fundus findings typical of nanophthalmos. The additional atypical features included serous pigment epithelial detachment (PED) in right eye and a cuff of subretinal fluid with underlying yellow deposits along superotemporal arcade in the left eye. Fundus flourescein angiogram showed hyperfluorescence due to window defect, dye pooling due to serous PED in right eye and leak superior to disc in right eye and superotemporally in left eye. Cirrus-SD OCT horizontal line scan passing through the fovea showed extensive inner limiting membrane corrugations causing distorted foveal contour in both eyes. A large juxtafoveal serous PED and a small extrafoval PED were seen with folds in the retinal pigment epithelium (RPE)-choriocapillary layer in the right eye. Conclusion Structural disruptions in the RPE-choriocapillary complex in the form of folds or juxtafoveal serous PED and RPE folds can be atypical features of nanophthalmic macula better discerned on high resolution OCT.

A regioselective hydroboration of alkynes has been developed by using commercially available zinc triflate as a catalyst, in the presence of catalytic amount of NaBHEt3. The reaction tolerates a wide range of terminal alkynes having several synthetically useful functional groups and proceeds regioselectively to furnish hydroborated products in moderate to excellent yields. This system shows moderate chemoselectivity towards terminal C≡C bond over terminal and internal C=C bond and internal C≡C bond. [ABSTRACT FROM AUTHOR]

Desert ants and honey bees start foraging when they are a few days old, and subsequently increase their foraging effort and the amount of foraged food. This could be an optimal strategy for scavenger/gatherer animals inhabiting landscapes with fewer features. However, animals inhabiting cluttered landscapes, especially predatory animals, may require substantial familiarity with foraging landscapes to forage efficiently. They may acquire such spatial familiarity with increasing age/experience, and eventually reduce their foraging effort without compromising on foraging success/efficiency. To check whether this holds for the individually foraging predatory tropical paper-wasp Ropalidia marginata, we recorded the number and duration of all foraging trips, the identity of foraged materials, and the directions of outbound and inbound flights (with respect to the nest) of known-age wasps for three consecutive days from three naturally occurring colonies; thus, we measured behavioural profiles of wasps of various ages, and not from the same wasp throughout its lifespan. Wasps increased their foraging duration rapidly until about 4 weeks of age, during which they rarely brought food, although some wasps brought building material and water. Thereafter, their foraging duration started decreasing. Nevertheless, their foraging success/efficiency in bringing food kept on increasing. With age, wasps developed individual directional preferences for outbound and inbound flights, indicating the development of spatial memory for rewarding sites. Also, the angular difference between their outbound and subsequent inbound flights gradually increased, indicating older wasps may have followed tortuous foraging routes. High investment in early life to acquire familiarity with foraging landscapes and using that later to perform efficient foraging could be an optimal strategy for individually foraging animals inhabiting feature-rich landscapes. [ABSTRACT FROM AUTHOR]