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Feb 2021 • Current Biology

Early life experience shapes male behavior and social networks in Drosophila

Assa Bentzur, Shir Ben-Shaanan, Jennifer IC Benichou, Eliezer Costi, Mali Levi, Amiyaal Ilany, Galit Shohat-Ophir

Living in a group creates a complex and dynamic environment in which behavior of individuals is influenced by and affects the behavior of others. Although social interaction and group living are fundamental adaptations exhibited by many organisms, little is known about how prior social experience, internal states, and group composition shape behavior in groups. Here, we present an analytical framework for studying the interplay between social experience and group interaction in Drosophila melanogaster. We simplified the complexity of interactions in a group using a series of experiments in which we controlled the social experience and motivational states of individuals to compare behavioral patterns and social networks of groups under different conditions. We show that social enrichment promotes the formation of distinct group structure that is characterized by high network modularity, high inter-individual and …

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Feb 2021 • Entropy

Non-Normalizable Quasi-Equilibrium Solution of the Fokker–Planck Equation for Nonconfining Fields

Celia Anteneodo, Lucianno Defaveri, Eli Barkai, David A Kessler

We investigate the overdamped Langevin motion for particles in a potential well that is asymptotically flat. When the potential well is deep as compared to the temperature, physical observables, like the mean square displacement, are essentially time-independent over a long time interval, the stagnation epoch. However, the standard Boltzmann–Gibbs (BG) distribution is non-normalizable, given that the usual partition function is divergent. For this regime, we have previously shown that a regularization of BG statistics allows for the prediction of the values of dynamical and thermodynamical observables in the non-normalizable quasi-equilibrium state. In this work, based on the eigenfunction expansion of the time-dependent solution of the associated Fokker–Planck equation with free boundary conditions, we obtain an approximate time-independent solution of the BG form, being valid for times that are long, but still short as compared to the exponentially large escape time. The escaped particles follow a general free-particle statistics, where the solution is an error function, which is shifted due to the initial struggle to overcome the potential well. With the eigenfunction solution of the Fokker–Planck equation in hand, we show the validity of the regularized BG statistics and how it perfectly describes the time-independent regime though the quasi-stationary state is non-normalizable.

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Feb 2021 • arXiv preprint arXiv:2102.01370

Efficient interaction of heralded x-ray photons with a beam splitter

E Strizhevsky, D Borodin, A Schori, S Francoual, R Röhlsberger, S Shwartz

Feb 2021 • Translational psychiatry

RNA editing of the 5-HT2C receptor in the central nucleus of the amygdala is involved in resilience behavior

Gal Warhaftig, Chaya Mushka Sokolik, Khen Khermesh, Yehuda Lichtenstein, Michal Barak, Tzofnat Bareli, Erez Y Levanon, Gal Yadid

Post-traumatic-stress-disorder (PTSD) is a stress-related condition that may develop after exposure to a severe trauma-event. One of the core brain areas that is considered to be a key regulatory region of PTSD is the amygdala. Specifically, the central amygdala (CeA) is involved in emotion processing and associative fear learning memory, two main circuits involved in PTSD. Long term dysregulation of trauma-related emotional processing may be caused by neuroadaptations that affect gene expression. The adenosine-(A) to-inosine (I) RNA editing machinery is a post-transcriptional process that converts a genomic encoded A to I and is critical for normal brain function and development. Such editing has the potential to increase the transcriptome diversity, and disruption of this process has been linked to various central nervous system disorders. Here, we employed a unique animal model to examine the possibility …

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Feb 2021 • Biophysical Journal

Quantitative Analysis of Actin Cytoskeleton's Morphological Changes during EMT in Lung Cancer and Pre-Cancer Cell Lines

Arkaprabha Basu, Manash K Paul, Mitchel Alioscha-Perez, Anna Grosberg, Hichem Sahli, Steven Dubinett, Shimon Weiss

Feb 2021

Novel Ceric Ammonium Nitrate-Stabilized Maghemite Nanoparticles (CAN-γ-Fe2O3) for Ultrasound Assisted Synthesis of β-Amino Derivatives

Anurag Kumar, Yifat Harel, Jean-paul Lellouche, Suman L Jain

Owing to their inherent features like smaller size and higher surface area exposed to reactants, nanoparticles have gained enormous interest and are extensively used as magnetically recyclable catalysts for various organic reactions. Herein, we report highly hydrophilic, non-aggregated, and strongly positively charged (ζ potential:+ 45.7 mV) ultra-small cerium cations/complexes-stabilized maghemite nanoparticles in water as an e cient and reusable nanoscaled magnetically active catalyst for the nucleophilic addition reaction of various amines with α, β-unsaturated carbonyl compounds to give corresponding β-amino derivatives under ultrasonic irradiation. The developed protocol provides several merits such as high product yields, mild reaction conditions, reusable catalyst and easy workup.

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Feb 2021 • OSA Continuum

Extraction of optical properties from a turbid medium using fiber probe for spectral and spatial diffuse reflectance measurement

Pavitra Sokke rudraiah, Hamootal duadi, Dror fixler

Diffuse reflectance technique is popular in the study of tissue physiology through the change in optical properties in a noninvasive manner. Diffuse reflected light intensity is commonly collected either from a single distance with spectral measurement or from a single wavelength with different spatial distances. Improving existing systems is necessary in order to obtain information from greater depths and in smaller volumes. In this paper, we propose a fast and compact fiber probe-based diffuse reflectance method for combining the spectral measurements in the range of 400–950 nm and spatial information up to 1.33 mm from the illumination source. First, we chose the most appropriate analysis model for the proposed distances between the fiber probe and tested it on solid phantoms with varying scattering and absorption components. The measurements are compared to the scattering coefficients according to Mie …

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Feb 2021 • ACS Applied Materials & Interfaces

Durable Tungsten Carbide Support for Pt-Based Fuel Cells Cathodes

Oran Lori, Shmuel Gonen, Omree Kapon, Lior Elbaz

In an effort to develop durable, corrosion-resistant catalyst support materials for polymer electrolyte fuel cells, modified polymer-assisted deposition method was used to synthesize tungsten carbide (WC, WC1–x), which was later used as a support material for Pt-based oxygen reduction reaction catalyst, as an alternative for the corrosion-susceptible, carbon supports. The Pt-deposited tungsten carbide’s corrosion-resistance, oxygen reduction reaction electrocatalysis, and durability were studied and compared to that of Pt/C. Bulk free carbon was found to be absent from the ceramic matrix which had particle size in the range of 2–25 nm. Tungsten carbide support appears to enhance the oxygen reduction activity on Pt, showing an increase in mass activity (nearly 2-fold at 0.85 V vs RHE) and specific activity (more than 7 times higher), alongside decrease in overpotential, in comparison to Pt/C. A significant increase in …

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Feb 2021 • Physical Review Letters

Pairwise Mode Locking in Dynamically Coupled Parametric Oscillators

Leon Bello, Marcello Calvanese Strinati, Shai Ben-Ami, Avi Pe’er

Mode locking in lasers is a collective effect, where due to a weak coupling a large number of frequency modes lock their phases to oscillate in unison, forming an ultrashort pulse in time. We demonstrate an analogous collective effect in coupled parametric oscillators, which we term “pairwise mode locking,” where many pairs of modes with twin frequencies (symmetric around the center carrier) oscillate simultaneously with a locked phase sum, while the phases of individual modes remain undefined. Thus, despite being broadband and multimode, the emission is not pulsed and lacks first-order coherence, while possessing a very high degree of second-order coherence. Our configuration comprises two coupled parametric oscillators within identical multimode cavities, where the coupling between the oscillators is modulated in time at the repetition rate of the cavity modes, with some analogy to active mode locking in …

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High-resolution radar road segmentation using weakly supervised learning (Feb, 10.1038/s42256-020-00288-6, 2021)

Itai Orr, Moshik Cohen, Zeev Zalevsky

Feb 2021 • Optics Express

Time multiplexing super-resolved imaging without a priori knowledge of the spatial distribution of the encoding structured illumination

Gal Chen, Abhijit Sanjeev, Vismay Trivedi, Javier Garcia, Ricardo Rubio, Zeev Zalevsky

Time multiplexing is a super-resolution technique that sacrifices time to overcome the resolution reduction obtained because of diffraction. There are many super resolution methods based on time multiplexing, but all of them require a priori knowledge of the time changing encoding mask, which is projected on the object and used to encode and decode the high-resolution information. In this paper, we present a time multiplexing technique that does not require the a priori knowledge on the projected encoding mask. First, the theoretical concept of the technique is demonstrated; then, numerical simulations and experimental results are presented.

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Feb 2021 • arXiv preprint arXiv:2102.12691

Weyl Semimetal Path to Valley Filtering in Graphene

Ahmed Khalifa, Ribhu K Kaul, Efrat Shimshoni, Herbert A Fertig, Ganpathy Murthy

We propose a device in which a sheet of graphene is coupled to a Weyl semimetal, allowing for the physical access to the study of tunneling from two-dimensional to three dimensional massless Dirac fermions. Due to the reconstructed band structure, we find that this device acts as a robust valley filter for electrons in the graphene sheet. We show that, by appropriate alignment, the Weyl semimetal draws away current in one of the two graphene valleys while allowing current in the other to pass unimpeded. In contrast to other proposed valley filters, the mechanism of our proposed device occurs in the bulk of the graphene sheet, obviating the need for carefully shaped edges or dimensions.

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Feb 2021 • Scientific reports

Correlation minor norms, entanglement detection and discord

Bar Y Peled, Amit Te’eni, Avishy Carmi, Eliahu Cohen

In this paper we develop an approach for detecting entanglement, which is based on measuring quantum correlations and constructing a correlation matrix. The correlation matrix is then used for defining a family of parameters, named Correlation Minor Norms, which allow one to detect entanglement. This approach generalizes the computable cross-norm or realignment (CCNR) criterion, and moreover requires measuring a state-independent set of operators. Furthermore, we illustrate a scheme which yields for each Correlation Minor Norm a separable state that maximizes it. The proposed entanglement detection scheme is believed to be advantageous in comparison to other methods because correlations have a simple, intuitive meaning and in addition they can be directly measured in experiment. Moreover, it is demonstrated to be stronger than the CCNR criterion. We also illustrate the relation between the …

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Feb 2021

Unravelling defect passivation mechanisms in sulfur-treated Sb2Se3

Rajiv Ramanujam Prabhakar, Thomas Moehl, Dennis Friedrich, Marinus Kunst, Sudhanshu Shukla, Damilola Adeleye, Vinayaka H Damle, Sebastian Siol, Wei Cui, Laxman Gouda, Jihye Suh, Yaakov R Tischler, Roel van de Krol, David Tilley

Sb2Se3 has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, despite its binary nature, Sb2Se3 has a complex defect chemistry, which reduces the maximum photovoltage that can be obtained. Thus, it is important to understand these defects and to develop passivation strategies in order to further improve this material. In this work, a comprehensive investigation of the charge carrier dynamics of Sb2Se3 and the influence of sulfur treatment on its optoelectronic properties was performed using time resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy and low frequency Raman spectroscopy (LFRS). The key finding in this work is that upon sulfur treatment of Sb2Se3, the carrier lifetime is increased by the passivation of deep defects in Sb2Se3 in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased radiative recombination efficiency and decreased deep defect level emission (PL), and improved long-range order in the material (LFRS). These findings provide crucial insights into the defect passivation mechanisms in Sb2Se3 paving the way for developing highly efficient PEC and PV devices.

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Feb 2021 • Nature Machine Intelligence

Author Correction: High-resolution radar road segmentation using weakly supervised learning

Itai Orr, Moshik Cohen, Zeev Zalevsky

In the version of this Article originally published, the colour bars labelled ‘Power (dB)’in Figs. 1–3, 5, 6 were incorrect; they should have been labelled ‘Amplitude (dB)’. In Fig. 5d, the colour bar labelled ‘Confidence level (dB)’was incorrect; it should have been labelled ‘Amplitude (dB)’. This has now been corrected.

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Feb 2021 • arXiv preprint arXiv:2102.12856

Supercontinuum Generation by Saturated Interactions

Marc Jankowski, Carsten Langrock, Boris Desiatov, Marko Loncar, MM Fejer

We demonstrate a new approach to supercontinuum generation and carrier-envelope-offset detection in dispersion-engineered nanophotonic waveguides based on saturated second-harmonic generation of femtosecond pulses. In contrast with traditional approaches based on self-phase modulation, this technique simultaneously broadens both harmonics by generating rapid amplitude modulations of the field envelopes. The generated supercontinuum produces coherent carrier-envelope-offset beatnotes in the overlap region that remain in phase across 100's of nanometers of bandwidth while requiring 10 picojoules of pulse energy.

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Feb 2021 • Journal of Applied Toxicology

In vitro copper oxide nanoparticle toxicity on intestinal barrier

Alessia Bertero, Graziano Colombo, Cristina Cortinovis, Virginia Bassi, Elisa Moschini, Nicholas Bellitto, Maria Chiara Perego, Marco Albonico, Emanuela Astori, Isabella Dalle‐Donne, Aharon Gedanken, Ilana Perelshtein, Paride Mantecca, Francesca Caloni

Feb 2021 • Journal of Applied Toxicology

In vitro copper oxide nanoparticle toxicity on intestinal barrier

Alessia Bertero, Graziano Colombo, Cristina Cortinovis, Virginia Bassi, Elisa Moschini, Nicholas Bellitto, Maria Chiara Perego, Marco Albonico, Emanuela Astori, Isabella Dalle‐Donne, Aharon Gedanken, Ilana Perelshtein, Paride Mantecca, Francesca Caloni

The use of CuO nanoparticles (NPs) has increased greatly and their potential effects on human health need to be investigated. Differentiated Caco‐2 cells were treated from the apical (Ap) and the basolateral (Bl) compartment with different concentrations (0, 10, 50 and 100 μg/mL) of commercial or sonochemically synthesized (sono) CuO NPs. Sono NPs were prepared in ethanol (CuOe) or in water (CuOw), obtaining CuO NPs differing in size and shape. The effects on the Caco‐2 cell barrier were assessed via transepithelial electrical resistance (TEER) evaluation just before and after 1, 2 and 24 hours of exposure and through the analysis of cytokine release and biomarkers of oxidative damage to proteins after 24 hours. Sono CuOe and CuOw NPs induced a TEER decrease with a dose‐dependent pattern after Bl exposure. Conversely, TEER values were not affected by the Ap exposure to commercial CuO NPs …

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Feb 2021 • Viruses

An Efficient, Counter-Selection-Based Method for Prophage Curing in Pseudomonas aeruginosa Strains

Esther Shmidov, Itzhak Zander, Ilana Lebenthal-Loinger, Sarit Karako-Lampert, Sivan Shoshani, Ehud Banin

Prophages are bacteriophages in the lysogenic state, where the viral genome is inserted within the bacterial chromosome. They contribute to strain genetic variability and can influence bacterial phenotypes. Prophages are highly abundant among the strains of the opportunistic pathogen Pseudomonas aeruginosa and were shown to confer specific traits that can promote strain pathogenicity. The main difficulty of studying those regions is the lack of a simple prophage-curing method for P. aeruginosa strains. In this study, we developed a novel, targeted-curing approach for prophages in P. aeruginosa. In the first step, we tagged the prophage for curing with an ampicillin resistance cassette (ampR) and further used this strain for the sacB counter-selection marker’s temporal insertion into the prophage region. The sucrose counter-selection resulted in different variants when the prophage-cured mutant is the sole variant that lost the ampR cassette. Next, we validated the targeted-curing with local PCR amplification and Whole Genome Sequencing. The application of the strategy resulted in high efficiency both for curing the Pf4 prophage of the laboratory wild-type (WT) strain PAO1 and for PR2 prophage from the clinical, hard to genetically manipulate, 39016 strain. We believe this method can support the research and growing interest in prophage biology in P. aeruginosa as well as additional Gram-negative bacteria.

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