bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of reading out the state of a charge quantum bit
Authors: Goan H-S.
Published: March 2021

We provide a unified picture for the master equation approach and the quantum trajectory approach to a measurement problem of a two-state quantum system (a qubit), an electron coherently tunneling between two coupled quantum dots (CQD's) measured by a low transparency point contact (PC) detector. We show that the master equation of ``partially'' reduced density matrix can be derived from the quantum trajectory equation (stochastic master equation) by simply taking a ``partial'' average over the all possible outcomes of the measurement. If a full ensemble average is taken, the traditional (unconditional) master equation of reduced density matrix is then obtained. This unified picture, in terms of averaging over (tracing out) different amount of detection records (detector states), for these seemingly different approaches reported in the literature is particularly easy to understand using our formalism. To further demonstrate this connection, we analyze an important ensemble quantity for an initial qubit state readout experiment, P(N,t), the probability distribution of finding N electron that have tunneled through the PC barrier(s) in time t. The simulation results of P(N,t) using 10000 quantum trajectories and corresponding measurement records are, as expected, in very good agreement with those obtained from the Fourier analysis of the ``partially'' reduced density matrix. However, the quantum trajectory approach provides more information and more physical insights into the ensemble and time averaged quantity P(N,t). Each quantum trajectory resembles a single history of the qubit state in a single run of the continuous measurement experiment. We finally discuss, in this approach, the possibility of reading out the state of the qubit system in a single-shot experiment.
Quantum lower bound for recursive Fourier sampling
Authors: Aaronson S.
Published: March 2021

We revisit the oft-neglected `recursive Fourier sampling' (RFS) problem, introduced by Bernstein and Vazirani to prove an oracle separation between BPP and BQP. We show that the known quantum algorithm for RFS is essentially optimal, despite its seemingly wasteful need to uncompute information. This implies that, to place \mathsf{BQP} outside of PH[\log] relative to an oracle, one would need to go outside the RFS framework. Our proof argues that, given any variant of RFS, either the adversary method of Ambainis yields a good quantum lower bound, or else there is an efficient classical algorithm. This technique may be of independent interest.
Local distinguishability of quantum states and the distillation of entanglement
Authors: Chen P.-X. , Li C.-Z.
Published: March 2021

This paper tries to probe the relation between the local distinguishability of orthogonal quantum states and the distillation of entanglement. An new interpretation for the distillation of entanglement and the distinguishability of orthogonal quantum states in terms of information is given, respectively. By constraining our discussion on a special protocol we give a necessary and sufficient condition for the local distinguishability of the orthogonal pure states, and gain the maximal yield of the distillable entanglement. It is shown that the information entropy, the locally distinguishability of quantum states and the distillation of entanglement are closely related.
Quantum communication protocols using the vacuum
Authors: van Enk S.J. , Rudolph T.
Published: March 2021

We speculate what quantum information protocols can be implemented between two accelerating observers using the vacuum. Whether it is in principle possible or not to implement a protocol depends on whether the aim is to end up with classical information or quantum information. Thus, unconditionally secure coin flipping seems possible but not teleportation.
Uncloneable encryption
Authors: Gottesman D.
Published: March 2021

Quantum states cannot be cloned. I show how to extend this property to classical messages encoded using quantum states, a task I call ``uncloneable encryption.'' An uncloneable encryption scheme has the property that an eavesdropper Eve not only cannot read the encrypted message, but she cannot copy it down for later decoding. She could steal it, but then the receiver Bob would not receive the message, and would thus be alerted that something was amiss. I prove that any authentication scheme for quantum states acts as a secure uncloneable encryption scheme. Uncloneable encryption is also closely related to quantum key distribution (QKD), demonstrating a close connection between cryptographic tasks for quantum states and for classical messages. Thus, studying uncloneable encryption and quantum authentication allows for some modest improvements in QKD protocols. While the main results apply to a one-time key with unconditional security, I also show uncloneable encryption remains secure with a pseudorandom key. In this case, to defeat the scheme, Eve must break the computational assumption behind the pseudorandom sequence before Bob receives the message, or her opportunity is lost. This means uncloneable encryption can be used in a non-interactive setting, where QKD is not available, allowing Alice and Bob to convert a temporary computational assumption into a permanently secure message.
An observable measure of entanglement for pure states of multi-qubit systems
Authors: Brennen G.
Published: March 2021

Recently, Meyer and Wallach [Meyer and Wallach (2002), J. of Math. Phys., 43, pp. 4273] proposed a measure of multi-qubit entanglement that is a function on pure states. We find that this function can be interpreted as a physical quantity related to the average purity of the constituent qubits and show how it can be observed in an efficient manner without the need for full quantum state tomography. A possible realization is described for measuring the entanglement of a chain of atomic qubits trapped in a 3D optical lattice.
Editorial Note
Authors: Shapiro J.H. , Lo H.-K.
Published: March 2021

entanglement, superposition, parametric downconversion, photonic technology, quantum information
Photon engineering for quantum information processing
Authors: U'Ren A.B. , Banaszek K. , Walmsley I.A.
Published: March 2021

We study distinguishing information in the context of quantum interference involving more than one parametric downconversion (PDC) source and in the context of generating polarization-entangled photon pairs based on PDC. We arrive at specific design criteria for two-photon sources so that when used as part of complex optical systems, such as photon-based quantum information processing schemes, distinguishing information between the photons is eliminated guaranteeing high visibility interference. We propose practical techniques which lead to suitably engineered two-photon states that can be realistically implemented with available technology. Finally, we study an implementation of the nonlinear-sign shift (NS) logic gate with PDC sources and show the effect of distinguishing information on the performance of the gate.
Atomic spins as a storage medium for quantum fluctuations of light
Authors: Julsgaard B. , Schori C. , Sorensen J. L. , Polzik E.S.
Published: March 2021

We review recent results showing the possibility to use off-resonant light/matter interaction for the purpose of quantum memory. A quantum state of atomic spins can be read out by light in a process which is a quantum analogue of the classical Faraday effect. Conversely, the dynamic Stark effect opens up the opportunity for recording the polarization state of light onto the atomic spin memory. We demonstrate that a sample of cesium atoms under appropriate conditions has the sensitivity to record properties of just a few photons, thus being a feasible candidate for quantum memory for light.
Experimental Progress in Linear Optics Quantum Computing
Authors: Franson J.D. , Donegan M.M. , Fitch M.J. , Jacobs B.C. , Pittman T.B.
Published: March 2021

Probabilistic quantum logic operations can be performed using linear optical elements and post-selection based on the results of measurements on ancilla photons. We review the results of a number of recent experiments in this area, including the demonstration of several quantum logic gates, the use of feed-forward control, a new source of single photons, and a quantum memory device for single photons. A high-fidelity approach in which the logic gates always produce an output will also be discussed.
Experimental realization of entangled qutrits for quantum communication
Authors: Thew R. , Acin A. , Zbinden H. , Gisin N.
Published: March 2021

We have experimentally realized a technique to generate, control and measure entangled qutrits, 3-dimensional quantum systems. This scheme uses spontaneous parametric down converted photons and unbalanced 3-arm fiber optic interferometers in a scheme analogous to the Franson interferometric arrangement for qubits. The results reveal a source capable of generating maximally entangled states with a net state fidelity, F = 0.985 $\pm$ 0.018. Further the control over the system reveals a high, net, 2-photon interference fringe visibility, V = 0.919 $\pm$ 0.026. This has all been done at telecom wavelengths thus facilitating the advancement towards long distance higher dimensional quantum communication.
Distributed construction of quantum fingerprints
Authors: Ambainis A. , Shi Y-Y
Published: March 2021

Quantum fingerprints are useful quantum encodings introduced by Buhrman, Cleve, Watrous and de Wolf (Physical Review Letters, Volume 87, Number 16, Article 167902, 2001) to obtain an efficient quantum communication protocol. We design a protocol for constructing the fingerprint in a distributed scenario. As an application, this protocol gives rise to a communication protocol more efficient than the best known classical protocol for a communication problem.
Quantum logical networks for probabilistic teleportation of many particle state of general form
Authors: Gao T. , Yan F.-L. , Wang Z.-X.
Published: March 2021

The scheme for probabilistic teleportation of an $N$-particle state of general form is proposed. As the special cases we construct efficient quantum logic networks for implementing probabilistic teleportation of a two-particle state, a three-particle state and a four-particle state of general form, built from single qubit gates, two-qubit controlled-not gates, Von Neumann measurement and classically controlled operations.
Security of quantum key distribution with imperfect devices
Authors: Gottesman D. , Lo H.-K. , L\"utkenhaus N. , Preskill J.
Published: March 2021

We prove the security of the Bennett-Brassard (BB84) quantum key distribution protocol in the case where the source and detector are under the limited control of an adversary. Our proof applies when both the source and the detector have small basis-dependent flaws, as is typical in practical implementations of the protocol. We derive a general lower bound on the asymptotic key generation rate for weakly basis-dependent eavesdropping attacks, and also estimate the rate in some special cases: sources that emit weak coherent states with random phases, detectors with basis-dependent efficiency, and misaligned sources and detectors.
Measuring polynomial functions of states
Authors: Brun T.A.
Published: March 2021

In this paper I show that any $m$th-degree polynomial function of the elements of the density matrix $\rho$ can be determined by finding the expectation value of an observable on $m$ copies of $\rho$, without performing state tomography. Since a circuit exists which can approximate the measurement of any observable, in principle one can find a circuit which will estimate any such polynomial function by averaging over many runs. I construct some simple examples and compare these results to existing procedures.
Research on the impact of artificial intelligence on the business model of an organization
Authors: Dashkov A. A. , Nesterova Yu. O.
Published: March 2021

The digital transformation of our world and the inevitable interaction between people, digital technologies and physical assets create a rapidly changing and complex environment that requires organizations to be more flexible, better fit and ready to accept new ways of working. Businesses are coming to realize the need for change to operate successfully in the digital age. In the period of global digitalization, information and communication technologies are one of the most important aspects of existence for a business, which makes it more efficient, efficient and allows you to respond quickly to a rapidly changing external environment, as well as customer needs. At the moment, there is a high interest in the possibilities of artificial intelligence for use in business tasks in the world, as there are already examples of successful implementation, when Artificial Intelligence and machine learning radically change the way they work and increase the profit of organizations in different countries.

The purpose of this study is to consider how artificial intelligence affects the value proposition and how the elements of the business model change when using this technology. The paper gives the existing examples of the use of technology, the consequences of its application and the emerging prospects for the use of Artificial Intelligence as one of the advanced technologies of digital transformation.
Intelligent technologies in the practice of the oil and gas sector
Authors: Davidenko L. M.
Published: March 2021

The oil and gas sector is among the leaders of the domestic industry in terms of the number of digital technologies being implemented. The complex technological chain of mining and processing industries is gradually moving into a system of intelligent management based on Digital Analytics. It is digital techniques of influencing the subject of management on an object, which gradually acquire algorithmized character, that become the head of scientific research and development of specialists in almost all sectors of the economy.

The article gives characteristics of digital tools for organizing and managing oil and gas production, describes the experience of domestic and foreign corporations in the development and application of information and communication technologies by covering the processes of supply, processing raw materials and sales of finished products. By summarizing the advanced achievements in building effective economic ties, the paper describes digital technologies as elements of a structural-functional approach with an emphasis on the possibilities and limitations of integrating technologies from industry leaders. The study proposes the author’s vision of the systematization of approaches in the field of “E-management” of oil and gas companies and their stakeholders, determined on the basis of the criterion for the effective development of the ecosystem of enterprises of the fuel and energy complex. As prospects for technological development in the direction of “E-management”, the expansion of the use of tools of intra-industry and intersectoral collaboration of resources, technological solutions, fixed assets based on macro-technological challenges is noted. The author concludes that “E-management”, as an innovative format of the production management system, contributes to sustainable development and growth of competitiveness of new generation industrial enterprises.
Transversal approach to digital risk management
Authors: Vorontsova Yu. V. , Baranov V. N.
Published: March 2021

The article presents a brief overview of digital risks, since their management is an integral part of business management. Digital transformation opens up incredible opportunities for both organizational growth and value creation. However, none of these opportunities can be realized without taking into account the associated risks. An increasing number of organizations are becoming vulnerable to certain types of digital threats. Risk management is critical to the sustainability of an organizations, and understanding risk areas is critical to identifying and eliminating all the risks that an organization may be exposed to in a digital environment. For effective management of digital risks, the authors highlight those their areas that seem to be the most significant.

The paper emphasizes three approaches to mitigating digital risks: tactical, operational and strategic. When studying the main areas of the emergence of digital risks in an organization, the authors concluded that it is necessary to develop a universal approach to creating an effective risk management mechanism in the digital environment. Within this approach, the article formulated the main stages of digital risk management.

As an effective toolkit in managing digital risks of an organization, the paper proposes to use a transversal approach, that is, the organization of such connections, interaction and cooperation between individual employees and divisions of the organization, which allow you to effectively implement processes associated with risk identification, their analysis, and decision-making aimed at minimization of possible negative consequences of already occurred risk events. At the same time, effective management of digital transformations to ensure cross-functional synergy presupposes the elimination of risks arising from interdependent processes. The study also proposes to develop a digital risk management strategy based on a transversal approach in integration with the digitalization strategy already being implemented in the organization. This approach will allow the organization to feel more confident in the future when implementing and using innovative technologies to solve the problems it faces.
Strong Binding of Noble Gases to [B12X11]˗: A Theoretical Study
Authors: Wöhner Kevin , Wulf Toshiki , Vankova Nina , Heine Thomas
Published: March 2021

We systematically explore the stability and properties of [B12X11Ng]− adducts resulting from the capture reaction of noble gas atoms (Ng) by anionic [B12X11]− clusters in the ion trap. [B12X11]− can be obtained by stripping one X− ligand off the icosahedral closo-dodecaborate dianion [B12X12]2−. We study the binding of the noble gas atoms He, Ne, Kr, Ar and Xe to [B12X11]− with ligands X = F, Cl, Br, I, CN. While He cannot be captured by these clusters and Ne only binds at low temperatures, the complexes with the heavier Kr, Ar and Xe show appreciable complexation energies and exceed 1 eV at room temperature in the case of [B12(CN)11Xe]−. For the latter three noble gases, we observe a significant charge transfer from the Ng to the icosahedral B12 cage.
Zirconia Nanotube Coatings - UV-Resistant Superhydrophobic Surfaces
Authors: Vakamulla Raghu Swathi Naidu , Killian Manuela S , Chuluunbandi Khajidkhand
Published: March 2021

Surface modifications influence material interactions such as wettability, imparting hydrophobicity or hydrophilicity. Mainstream research focused on enhancing product shelf-life, directs attention towards superhydrophobic surfaces (SHS). SHS offer several benefits for outdoor applications such as self-cleaning, anti-soiling, anti-mist etc. In this manuscript, we explore the possibility of combining structural and chemical modifications to metal substrates in order to create superhydrophobic metal oxide surfaces. ZrO2-nanotubes are evaluated with regard to their application as transparent UV-stable superhydrophobic coatings. Nanostructured oxide surfaces are created via single-step electrochemical anodization. The absence of HF acid-based pre-etching steps offer a safe and alternatively a green synthesis route. Anodized oxides are modified using octadecylphosphonic acid self-assembled monolayers, demonstrate superhydrophobicity and are evaluated for their mechanical stability under a jet of water, chemical stability under indirect sunlight irradiation in air/water and direct UV exposure. Zirconia nanotubular films were evaluated for optical transparency using light microscopy and surface wettability of the different zirconia-composites was compared to the model system-titania. Structural and compositional differences of the SAM layer upon time dependent decay were analyzed with X-ray photoelectron spectroscopy.
An Engineered Nonribosomal Peptide Synthetase Shows Opposite Amino Acid Loading and Condensation Specificity
Authors: Stanišić Aleksa , Hüsken Annika , Stephan Philipp , Niquille David L. , Reinstein Jochen , Kries Hajo
Published: March 2021

Engineering of nonribosomal peptide synthetases (NRPS) has faced numerous obstacles despite being an attractive path towards novel bioactive molecules. Specificity filters in the nonribosomal peptide assembly line determine engineering success, but the relative contribution of adenylation (A-) and condensation (C-)domains is under debate. In the engineered, bimodular NRPS sdV-GrsA/GrsB1, the first module is a subdomain-swapped chimera showing substrate promiscuity. On sdV-GrsA and evolved mutants, we have employed kinetic modelling to investigate product specificity under substrate competition. Our model contains one step, in which the A-domain acylates the thiolation (T-)domain, and one condensation step deacylating the T-domain. The simplified model agrees well with experimentally determined acylation preferences and shows that the condensation specificity is mismatched with the engineered acylation specificity. Our model predicts changing product specificity in the course of the reaction due to dynamic T-domain loading, and that A-domain overrules C-domain specificity when T-domain loading reaches a steady-state. Thus, we have established a tool for investigating poorly accessible C-domain specificity through nonlinear kinetic modeling and gained critical insights how the interplay of A- and C-domains determines the product specificity of NRPSs.
Regiodivergent Biocatalytic Hydroxylation of L-Glutamine Facilitated by Characterization of Non-Heme Dioxygenases from Non-Ribosomal Peptide Biosyntheses
Authors: Renata Hans , Shimizu Emily , Zwick Christian
Published: March 2021

We report the functional characterization of two iron- and a-ketoglutarate-dependent dioxygenases that are capable of hydroxylating free-standing glutamine at its C3 and C4 position respectively. In particular, the C4 hydroxylase, Q4Ox, catalyzes the reaction with approximately 4,300 total turnover numbers, facilitating synthesis of a solid-phase compatible building block and stereochemical elucidation at the C4 position of the hydroxylated product. This work will enable the development of novel synthetic strategies to prepare useful glutamine derivatives and stimulate further discoveries of new amino acid hydroxylases with distinct substrate specificities.
P(III) vs. P(V): A P(V) Reagent for Thiophosphoramidate Linkages and Application to An Asymmetric Synthesis of a Cyclic Dinucleotide STING Agonist
Authors: Zheng Bin , Hang Chao , Zhu Jason , Purdum Geoffrey , Sezen-Edmonds Melda , Treitler Daniel , Yu Miao , Yuan Changxia , Zhu Ye , Freitag Adam , Guo Siwei , Zhu Guanghui , Hritzko Benjamin , Paulson James , Shackman Jonanthan , He Brian , Fu Weiqing , Tai HuaChia , Ayers Sloan , Park Hyunsoo , Eastgate Martin , Cohen Benjamin , Rogers Amanda , Wang Qinggang , Schmidt Michael A.
Published: March 2021

A highly stereoselective synthesis of a cyclic dinucleotide (CDN) STING agonist containing two chiral thiophosphoramidate linkages is described. These rare, yet key functional groups were, for the first time, installed efficiently and with high diastereoselectivity using a specially designed P(V) reagent. By utilizing this strategy, the CDN was prepared in greater than sixteen-fold higher yield than the prior P(III) approach, with fewer hazardous reagents and chromatographic purifications.
Cobalt Hydride Oxidase Catalysis Enabled Hydroamination of Unactivated Olefins
Authors: Ye Wei-Ting , Zhu Rong
Published: March 2021

Dioxygen is an abundant, selective, and sustainable oxidant that is considered ideal for organic transformations. Oxidative processes using dioxygen as the electron acceptor without oxygen atom incorporation into the substrate are often referred to as oxidase reactions. However, the ground state triplet nature of dioxygen makes such a synthetically valuable pathway incompatible with simple free alkyl radicals, a ubiquitous class of reactive intermediates in the daily synthesis of pharmaceuticals, agrochemicals, and complex natural products. Here we report that a combination of strong cage effect and bimetallic radical-polar crossover successfully addresses this problem, and opens up an oxidase pathway in cobalt hydride catalysis. This leads to a general and chemoselective method that tackles several key challenges in catalytic hydroamination, a fundamental transformation for amine synthesis. Under balloon pressure of dioxygen at ambient temperature, we demonstrate single-step intra- and intermolecular formal addition of a variety of nitrogen nucleophiles, including free amines, sulfonamides, amides, and carbamates, to unactivated alkenes in the presence of a silane, under solvent-free conditions. Important medicinal chemistry building blocks such as a-branched tertiary amines can be easily accessed, which are often difficult targets otherwise due to their steric hindrance and reducing nature. Mechanistic studies including stoichiometric experiments with well-defined organocobalt complexes provide support for the key hypothesis, which points the way to the development of sustainable processes involving other nucleophiles based on the same design elements.
Competitive Light Emission from Excited Electron and Proton Systems in Polyaniline Doped with P-Toluenesulfonic Acid When Electrically Powered
Authors: Langer Jerzy J. , Ratajczak Katarzyna C. , Frąckowiak Ewelina , Golczak Sebastian
Published: March 2021

Polyaniline doped with p-toluenesulfonic acid (PANI/PTSA) emits light in two different ranges owing to electron and proton excitations. The protons effectively compete with the electrons in the wet PANI/PTSA in capturing the electrical energy.
Osteopontin (OPN) Downregulatory Alkaloid (-)-Agelastatin A Prevents Muscle Damage in a Mouse Model of Duchenne Muscular Dystrophy
Authors: Feng Madison , Lopez Sara Mata , Manaviazar Soraya , Watson Hamish A. , Hale Karl , Nghiem Peter P
Published: March 2021

(-)-Agelastatin A (AA) in 1,2-propanediol (3-deoxy-DL-glycerol) elicits a dose-dependent decrease in OPN mRNA expression in canine Duchenne Muscular Dystrophy (DMD) myoblasts at doses ranging from 0.01 nM-30 nM. When intraperitoneally administered in the same vehicle to mdx mice at 2.5 mg/kg/day for two weeks, and at 1.5 mg/kg/day twice-weekly for two weeks, (-)-AA brings about a significant decrease in exercise-induced muscle damage through its attenuation of OPN expression. Because (-)-AA is known to downregulate OPN, this study confirms that the use of small molecule OPN downregulatory drugs can beneficially modify the phenotype in DMD animal models and potentially affected boys
Enantioselective Construction of Trialkyl Tertiary Centers via Ni-Catalyzed Markovnikov Hydrocarbofunctionalizations of Unactivated Olefins and Electrophiles
Authors: Shu Wei , Yang Peng-Fei , Liang Jian-Xin , Zhao Han-Tong , Zhang Jian-Xin , Zeng Xian-Wang
Published: March 2021

Routes to efficient construction of fully aliphatic substituted tertiary chiral centers are highly challenging and desirable. Herein, a Ni-catalyzed enantioselective hydroalkylation of unactivated alkenes at room temperature is described, providing a general and practical access to tertiary stereogenic carbon centers with three alkyl substituents. This reaction involves the regio- and stereoselective hydrometalation of unactivated alkenes with Markovnikov selectivity, followed by coupling with unactivated alkyl electrophiles to access tertiary chiral centers with full alkyl substituents. The mild and robust conditions enable the use of terminal and internal unactivated alkenes as well as primary and secondary unactivated alkyl, benzyl, propargyl halides for the construction of diverse trialkyl tertiary stereogenic carbon centers with broad functional group tolerance.
On the Completeness of Three-Dimensional Electron Diffraction Data for Structural Analysis of Metal-Organic Frameworks
Authors: Ge Meng , Yang Taimin , Wang Yanzhi , Carraro Francesco , Liang Weibin , Doonan Christian , falcaro paolo , Zheng Haoquan , Zou Xiaodong , Huang Zhehao
Published: March 2021

Three-dimensional electron diffraction (3DED) has been proven as an effective and accurate method for structure determination of nano-sized crystals. In the past decade, the crystal structures of various new complex metal-organic frameworks (MOFs) have been revealed by 3DED, which has been the key to understand their properties. However, due to the design of transmission electron microscopes (TEMs), one drawback of 3DED experiments is the limited tilt range of goniometer, which often leads to incomplete 3DED data, particularly when the crystal symmetry is low. This drawback can be overcome by high throughput data collection using continuous rotation electron diffraction (cRED), where data from a large number of crystals can be collected and merged. Here, we investigate the effects of improving completeness on structural analysis of MOFs. We use ZIF-EC1, a zeolitic imidazolate framework (ZIF), as an example. ZIF-EC1 crystallizes in a monoclinic system with a plate-like morphology. cRED data of ZIF-EC1 with different completeness and resolution were analyzed. The data completeness increased to 92.0% by merging ten datasets. Although the structures could be solved from individual datasets with a completeness as low as 44.5% and refined to a high precession (better than 0.04 Å), we demonstrate that a high data completeness could improve the structural model, especially on the electrostatic potential map. We further discuss the strategy adopted during data merging. We also show that ZIF-EC1 doped with cobalt can act as an efficient electrocatalyst for oxygen reduction reaction.
Proton Transfer and Kinetic Isotope Effect in Morita-Baylis-Hillman Reaction Under Solvent Effects. a Detailed Computational Study
Authors: Yadav Veejendra
Published: March 2021

Solvent effects of CH2Cl2, CH3CN, THF and DMSO on the profile of the Morita-Baylis-Hillman (MBH) reaction were discovered to lower the activation energy of aldol step. Proton-transfer through seven-membered TS state structure enroute Hofmann elimination and also the four-membered TS structure are sufficiently low energy processes in comparison to aldol reaction and, hence, unlikely to contribute to the overall kinetics of the reaction. As an exception, proton-transfer through seven-membered TS structure constitutes the rate-controlling event for the DABCO-catalyzed reaction of methyl acrylate with p-nitrobenzaldehyde under the solvent effects of DMSO. The acetal route was not found to contribute to kinetic isotope effect, which has otherwise been measured to be as high as 5.2 ± 0.6. The simultaneous proton-transfer to the aldol-derived alkoxide and abstraction of proton from the a-carbon of activated alkene by hydroxylic solvents was found to be barrier-less. The reported catalysis by hydroxylic solvents is therefore likely by lowering the activation energy of the aldol step due to activation of aldehyde possibly by protonation or hydrogen-bonding. The present computational results are in excellent agreement with the more than three decade old experimental findings of Hill and Isaacs. These authors have reported the aldol step as rate-limiting and absolutely no kinetic isotope effect.
Hyperpolarizability of Water at the Air-Vapor Interface: Numerical Modeling Questions Standard Experimental Approximations
Authors: Le Breton Guillaume , Bonhomme Oriane , Brevet Pierre-François , Benichou Emmanuel , Loison Claire
Published: March 2021

In this article, we investigate the molecular first hyperpolarizability of water molecules nearby the liquid-vapor interface. The hyperpolarizability of each molecule is calculated at the quantum level within an explicit, inhomogeneous electrostatic embedding. We report that the average molecular first hyperpolarizability tensor depends on the distance relative to the interface, but it practically respects the Kleinman symmetry everywhere in the liquid. Within this numerical approach, based on the dipolar approximation, the water layer contributing to the Surface Second Harmonic Generation (S-SHG) intensity is less than a nanometer. We show that within this interfacial layer, the common assumption considering a single, constant hyperpolarizability for all water molecules is not supported by our data: hyperpolarizability fluctuations are expected to impact the S-SHG intensity. These results represent a step forward the molecular interpretation of experimental S-SHG signal of aqueous interfaces.
The Synthesis Properties and Reactivity of Lewis Acidic Aminoboranes
Authors: Bentley Jordan N. , Simoes Selvyn A. , Pradhan Ekadashi , Zeng Tao , Caputo Chris
Published: March 2021

The evolution of frustrated Lewis pair chemistry has led to significant research into the development of new Lewis acidic boranes. Much of this has focused on modifying aryl substituents rather than introducing heteroatoms bound to boron. We recently reported unique Lewis acidic behaviour from bis(pentafluorophenyl)phenothiazylborane (1) for the heterolytic dehydrocoupling of stannanes. In this work, we synthesize and characterize a family of Lewis acidic aminoboranes and explored their reactivity with various Lewis bases as well as their efficacy as catalysts for stannane dehydrocoupling and hydrosilylation. Quantum chemical caluclations were undertaken to understand the origins of the Lewis acidity and the most Lewis acidic aminoborane (5) was found to be an effective catalyst even in coordinating solvents such as water or acetonitrile, suggesting the amino substituent provides a level of protection against competing donors.
Multicomponent Crystals with Two Fast Reorienting Constituents: Mutually Affected Rotation of DABCO and THF
Authors: Colin-Molina Abraham , Arcudia Jessica , López-López Eliseo R. , Jellen Marcus J. , García-González Ma. Carmen , Merino Gabriel , Rodríguez-Molina Braulio
Published: March 2021

Here we report two new multicomponent supramolecular rotors (1 and 2) based on 2,7-diphenyl-9H-carbazole stators and two rotators brought together by a non-innocent C-H…O interaction. This hydrogen bond serves a dual function: it constitutes the rotational axis for THF and acts as a ‘brake’ for the motion of DABCO. Dynamic characterization of 1 by VT 2H NMR experiments supports that DABCO rotates about its supramolecular axis with jumps of 120º (3-fold) and a krot >10 MHz at 300 K, but interestingly, this motion is reduced to 5 MHz at 150 K. Concurrently, the THF experiences an atypical motion on an axis that is perpendicular to that of DABCO, experiencing 180º jumps in the fast regime even at 175 K. 1H(T1) relaxometry studies show that DABCO has an Ea=3.5 kcal/mol, while for THF, an Ea=2.3 kcal/mol was computed by periodic DFT. Fast and organized mobility of two constituents within crystals is extremely infrequent and could have strong implications for future applications of multicomponent solids with regulated dynamics.
Genetic screening of autism, a neurodevelopmental disorder: A review
Authors: Ranjana Shaw  , Tamalika Chakraborty  , Dipanjan Mandal
Published: March 2021

Neurodevelopmental disorders are conditions that arise from aberrant encephalon magnification and development, are perennial, crippling illness. Autism spectrum disorder (autism) is a common neurodevelopmental disability characterized by motor, social, cognitive function, stereotypies. This study aimed to investigate the genetic constitution of autism, an animal model named zebrafish serves as an indispensable tool for this purpose. Zebrafish is a highly gregarious species that acts as a suitable animal model system that affects convivial functions such as autism. Since transparent embryos are developed externally in zebrafish, it enables to conduct pharmacological screens for recognition of minute molecules along with genetic manipulation, facilitated through the CRISPR/Cas9 gene-editing technologies, enabling the screening of the developing nervous system directly, large progenies, and substantial tractability. Mutational analysis of the genetic function has been used to suppress or express mutations in zebrafish homologs of human genes for the direct expression of human genes bearing mutations cognate to a neurodevelopmental disorder. Two areas of future research are addressed through the ease and relative speed of conducting experiments in zebrafish, which includes environmental factors contributing to disease onset, and screening for novel therapeutic compounds. This study found that zebrafish have become available for cell-based analysis and have been used for the prosperous modelling of autism. Continued innovations in zebrafish genetic implements will continue to make it a captivating neurological disease model.
Phylo-geo-network and haplogroup analysis of 611 novel coronavirus (SARS-CoV-2) genomes from India
Authors: Laskar Rezwanuzzaman , Ali Safdar
Published: March 2021

The novel coronavirus (SARS-CoV-2) from Wuhan China discovered in December 2019 has since developed into a global epidemic. Presently, we constructed and analyzed the phylo-geo-network of SARS-CoV-2 genomes from across India to understand the viral evolution in the country. A total of 611 full-length genomes from different states of India were extracted from the EpiCov repository of GISAID initiative on 6 June, 2020. Their alignment with the reference sequence (Wuhan, NCBI accession number NC_045512.2) uncovered 270 parsimony informative sites. Furthermore, 339 genomes were divided into 51 haplogroups. The network revealed the core haplogroup as that of reference sequence NC_045512.2 (Haplogroup A1) with 157 identical sequences present across 16 states. Remaining haplogroups had <10 identical sequences across a maximum of three states. Some states with fewer samples had more haplogroups. Forty-one haplogroups were localized exclusively to any one state. The two most common lineages are B6 and B1 (Pangolin) whereas clade A2a (Covidex) appears to be the most predominant in India. Because the pandemic is still emerging, the observations need to be monitored.
LRRK2-phosphorylated Rab10 sequesters Myosin Va with RILPL2 during ciliogenesis blockade
Authors: Dhekne Herschel S , Yanatori Izumi , Vides Edmundo G , Sobu Yuriko , Diez Federico , Tonelli Francesca , Pfeffer Suzanne R
Published: March 2021

Activating mutations in LRRK2 kinase causes Parkinson’s disease. Pathogenic LRRK2 phosphorylates a subset of Rab GTPases and blocks ciliogenesis. Thus, defining novel phospho-Rab interacting partners is critical to our understanding of the molecular basis of LRRK2 pathogenesis. RILPL2 binds with strong preference to LRRK2-phosphorylated Rab8A and Rab10. RILPL2 is a binding partner of the motor protein and Rab effector, Myosin Va. We show here that the globular tail domain of Myosin Va also contains a high affinity binding site for LRRK2-phosphorylated Rab10. In the presence of pathogenic LRRK2, RILPL2 and MyoVa relocalize to the peri-centriolar region in a phosphoRab10-dependent manner. PhosphoRab10 retains Myosin Va over pericentriolar membranes as determined by fluorescence loss in photobleaching microscopy. Without pathogenic LRRK2, RILPL2 is not essential for ciliogenesis but RILPL2 over-expression blocks ciliogenesis in RPE cells independent of tau tubulin kinase recruitment to the mother centriole. These experiments show that LRRK2 generated-phosphoRab10 dramatically redistributes a significant fraction of Myosin Va and RILPL2 to the mother centriole in a manner that likely interferes with Myosin Va’s role in ciliogenesis.
Volunteering in libraries: survey on Romanian public libraries
Authors: Constantinescu Mihai , Danciu Alina , Haimana Dana
Published: March 2021

Libraries are a natural hotspot for volunteer work, they can act as both beneficiaries and organizers of volunteers and their work. Volunteer programs in the libraries cover an important range of possibilities, from basic library work (moving books, assisting users that need help) to specialized activities (language courses, computer courses, specialized activities with persons with disabilities) and everything in between.

This study aims to offer an overview of the situation regarding volunteer work in Romanian public libraries. It seeks to find out whether and how the county libraries and the two national libraries use volunteers.
A multi-objective artificial bee colony approach to feature selection using fuzzy mutual information
Authors: Hancer E , Xue Bing , Zhang Mengjie , Karaboga D , Akay B
Published: March 2021

© 2015 IEEE. Feature selection often involves two conflicting objectives of minimizing the feature subset size and the maximizing the classification accuracy. In this paper, a multi-objective artificial bee colony (MOABC) framework is developed for feature selection in classification, and a new fuzzy mutual information based criterion is proposed to evaluate the relevance of feature subsets. Three new multi-objective feature selection approaches are proposed by integrating MOABC with three filter fitness evaluation criteria, which are mutual information, fuzzy mutual information and the proposed fuzzy mutual information. The proposed multi-objective feature selection approaches are examined by comparing them with three single-objective ABC-based feature selection approaches on six commonly used datasets. The results show that the proposed approaches are able to achieve better performance than the original feature set in terms of the classification accuracy and the number of features. By using the same evaluation criterion, the proposed multi-objective algorithms generally perform better than the single-objective methods, especially in terms of reducing the number of features. Furthermore, the proposed fuzzy mutual information criterion outperforms mutual information and the original fuzzy mutual information in both single-objective and multi-objective manners. This work is the first study on multi-objective ABC for filter feature selection in classification, which shows that multi-objective ABC can be effectively used to address feature selection problems.

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Laypeople's Collaborative Immersive Virtual Reality Design Discourse in Neighborhood Design
Authors: Chowdhury Shuva , Schnabel Marc Aurel
Published: March 2021

The article discusses design communication and participation of laypeople in a virtual participatory urban design process. We speculate that an immersive virtual environment facilitated instrument can allow laypeople to take part actively as designers in the early stage of urban design ideation and generation. We have developed a design communication framework where laypeople can participate in design discourse on a neighborhood's future urban form. The strategy describes an urban design intent, which is informed by the development procedure of an instrument and workflow to engage participants. The integration of the instrument and the engagement procedure enable continuous designing of urban form by laypeople. A protocol analysis has been undertaken to investigate design communication. A coding scheme is applied to investigate, analyse, and understand how laypeople communicate with the design instrument and control design in the virtual environment. Through engaging non-experts, the research impacts on the perceptual affordance created by immersive 3D buildings artifacts and verbal conversation. The protocol analysis validated the setup so that subsequent studies can address the meaningfulness of such design conversations.
The failure of health promotion for marginalised populations
Authors: Roguski M , McBride-Henry Karen
Published: March 2021

No description supplied
Spatial and temporal variability of precipitation extreme indices in arid and semi-arid regions of Iran for the last half-century
Authors: Karimi Sadegh , Nazaripour Hamid , Hamidianpour Mohsen
Published: March 2021

Precipitation variability analysis, on different spatial and temporal scales, has been of great concern during the past century because of the attention given to global climate change by the scientific community. According to some recent studies, the Iranian territory has been experienced a precipitation variability, especially in the last 50 years, and the arid and semi-arid areas seem to be more affected. The present study aims to analyze precipitation extreme indices over a wide time interval and a wide area, detecting potential trends and assessing their significance. The investigation is based on a wide range of daily and multi-day precipitation statistics encompassing basic characteristics and heavy precipitation. Two different methods of trend analysis and statistical testing are applied, depending on the nature of the statistics. Linear regression is used for statistics with a continuous value range, and logistic regression is used for statistics with a discrete value range. The trends are calculated on annual and seasonal bases for the years 1951–2007. Statistical analysis of the database highlight that a clear trend signal is found with a high number of sites with a statistically significant trend. In winter, significant increases are found for all statistics related to precipitation strength and occurrence. In spring, statistically, significant increases are found only for the statistics related to heavy precipitation, whereas precipitation frequency and occurrence statistics show little systematic change. The trend signal is strongest in highlands and mountainous terrains. In autumn and summer, the heavy and basic precipitation statistics did not show statistically significant trends.
Evapotranspiration and yield components of soybean
Authors: Anda Angela , Menyhárt László , Simon Brigitta
Published: March 2021

Observation was conducted to determine the impact of water deprivation under flowering on the yield components of soybean at Keszthely, in the growing seasons between 2017 and 2018. The soybean represents an artificial ecosystem in this study. Three water levels designated as full watering in traditionally operated evapotranspirometer (ET), water withdrawal under crop flowering in modified evapotranspirometer (RO), and rainfed (P) crops were used. In RO treatments, the crops received half of the water based on the amount of unlimited water supply. Irrespective of variety, the highest water uses were obtained in ET, while the lowest ones were observed in RO over both growing seasons. Surprisingly, in spite of different variety standards provided by the crop breeders, and irrespective to water supply, no significant impact in actual evapotranspiration rate, ETa, between the two varieties was observed. Significant impact in soybean water losses between the treatments was observed in RO as compared to the evapotranspiration of crops with unlimited watering.