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Jul 2022 • Photonics Research

Surface acoustic wave photonic filters with a single narrow radio-frequency passband in standard silicon on insulator

Moshe Katzman, Maayan Priel, Inbar Shafir, Saawan Kumar Bag, Dvir Munk, Naor Inbar, Moshe Feldberg, Tali Sharabani, Leroy Dokhanian, Matan Slook, Avi Zadok

Integrated microwave photonic filters are becoming increasingly important for signal processing within advanced wireless and cellular networks. Filters with narrow transmission passbands mandate long time delays, which are difficult to accommodate within photonic circuits. Long delays may be obtained through slow moving acoustic waves instead. Input radio-frequency information can be converted from one optical carrier to another via surface acoustic waves and filtered in the process. However, the transfer functions of previously reported devices consisted of multiple periodic passbands, and the selection of a single transmission band was not possible. In this work, we demonstrate surface acoustic wave, silicon-photonic filters of microwave frequency with a single transmission passband. The filter response consists of up to 32 tap coefficients, and the transmission bandwidth is only 7 MHz. The results extend the capabilities of integrated microwave photonics in the standard silicon-on-insulator platform.

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Jun 2022 • arXiv preprint arXiv:2206.04166

Planning with Dynamically Estimated Action Costs

Eyal Weiss, Gal A Kaminka

Information about action costs is critical for real-world AI planning applications. Rather than rely solely on declarative action models, recent approaches also use black-box external action cost estimators, often learned from data, that are applied during the planning phase. These, however, can be computationally expensive, and produce uncertain values. In this paper we suggest a generalization of deterministic planning with action costs that allows selecting between multiple estimators for action cost, to balance computation time against bounded estimation uncertainty. This enables a much richer -- and correspondingly more realistic -- problem representation. Importantly, it allows planners to bound plan accuracy, thereby increasing reliability, while reducing unnecessary computational burden, which is critical for scaling to large problems. We introduce a search algorithm, generalizing , that solves such planning problems, and additional algorithmic extensions. In addition to theoretical guarantees, extensive experiments show considerable savings in runtime compared to alternatives.

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Jun 2022 • arXiv e-prints

Network Model of Active Fluctuations of Thin Elastic Shells Swollen by Hydrostatic Pressure

Ajoy Maji, Yitzhak Rabin

Many organisms have an elastic skeleton that consists of a closed shell of epithelial cells that is filled with fluid, and can actively regulate both elastic forces in the shell and hydrostatic pressure inside it. In this work we introduce a simple network model of such pressure-stabilized active elastic shells in which cross-links are represented by material points connected by non-linear springs of some given equilibrium lengths and spring constants. We mimic active contractile forces in the system by changing the parameters of randomly chosen springs and use computer simulations to study the resulting local and global deformation dynamics of the network. We elucidate the statistical properties of these deformations by computing the corresponding distributions and correlation functions. We show that pressure-induced stretching of the network introduces coupling between its local and global behavior: while the network …

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Jun 2022 • arXiv preprint arXiv:2206.03356

Position Paper: Online Modeling for Offline Planning

Eyal Weiss, Gal A Kaminka

The definition and representation of planning problems is at the heart of AI planning research. A key part is the representation of action models. Decades of advances improving declarative action model representations resulted in numerous theoretical advances, and capable, working, domain-independent planners. However, despite the maturity of the field, AI planning technology is still rarely used outside the research community, suggesting that current representations fail to capture real-world requirements, such as utilizing complex mathematical functions and models learned from data. We argue that this is because the modeling process is assumed to have taken place and completed prior to the planning process, i.e., offline modeling for offline planning. There are several challenges inherent to this approach, including: limited expressiveness of declarative modeling languages; early commitment to modeling choices and computation, that preclude using the most appropriate resolution for each action model -- which can only be known during planning; and difficulty in reliably using non-declarative, learned, models. We therefore suggest to change the AI planning process, such that is carries out online modeling in offline planning, i.e., the use of action models that are computed or even generated as part of the planning process, as they are accessed. This generalizes the existing approach (offline modeling). The proposed definition admits novel planning processes, and we suggest one concrete implementation, demonstrating the approach. We sketch initial results that were obtained as part of a first attempt to follow this approach by planning …

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Sourcing Herod the Great's calcite-alabaster bathtubs by a multi-analytic approach (vol 12, 7524, 2022)

Ayala Amir, Amos Frumkin, Boaz Zissu, Aren M Maeir, Gil Goobes, Amnon Albeck

Jun 2022 • arXiv preprint arXiv:2106.00423

Reentrant transitions in a mixture of small and big particles interacting via soft repulsive potential

Itay Azizi, Alexander Y Grosberg, Yitzhak Rabin

We report the first observation of temperature-controlled reentrant transition in simulations of mixtures of small and big particles interacting via soft repulsive potential in 2d. As temperature increases, the system passes from a fluid mixture, to a crystal of big particles in a fluid of small particles and back to a fluid mixture. Solidification is driven by entropy gain of small particles which overcomes the free energy cost of confining big ones. Melting results from enhanced interpenetration of particles at high temperature which reduces the entropic forces that stabilize the crystal.

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Jun 2022 • arXiv preprint arXiv:2206.12926

Rivendell: Project-Based Academic Search Engine

Teddy Lazebnik, Hanna Weitman, Yoav Goldberg, Gal A Kaminka

Finding relevant research literature in online databases is a familiar challenge to all researchers. General search approaches trying to tackle this challenge fall into two groups: onetime search and life-time search. We observe that both approaches ignore unique attributes of the research domain and are affected by concept drift. We posit that in searching for research papers, a combination of a life-time search engine with an explicitly-provided context (project) provides a solution to the concept drift problem. We developed and deployed a project-based meta-search engine for research papers called Rivendell. Using Rivendell, we conducted experiments with 199 subjects, comparing project-based search performance to one-time and life-time search engines, revealing an improvement of up to 12.8 percent in project-based search compared to life-time search.

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Jun 2022 • ACS Applied Electronic Materials

Current Mapping of Amorphous LaAlO3/SrTiO3 near the Metal–Insulator Transition

Anders V Bjørlig, Dennis V Christensen, Ricci Erlandsen, Nini Pryds, Beena Kalisky

The two-dimensional electron system found between LaAlO3 and SrTiO3 hosts a variety of physical phenomena that can be tuned through external stimuli. This allows for electronic devices controlling magnetism, spin–orbit coupling, and superconductivity. Controlling the electron density by varying donor concentrations and using electrostatic gating are convenient handles to modify the electronic properties, but the impact on the microscopic scale, particularly of the former, remains underexplored. Here, we image the current distribution at 4.2 K in amorphous-LaAlO3/SrTiO3 using scanning superconducting quantum interference device microscopy while changing the carrier density in situ using electrostatic gating and oxygen annealing. We show how potential disorder affects the current and how homogeneous 2D flow evolves into several parallel conducting channels when approaching the metal-to-insulator …

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Jun 2022 • Progress in Polymer Science, 101574, 2022

3D printed magnetic polymer composite hydrogels for hyperthermia and magnetic field driven structural manipulation

Sayan Ganguly, Shlomo Margel

Magnetic hydrogels and soft composites have fuelled the development of next generation biomimetic soft robotics due to their precise control and non-cytotoxic nature. Bare magnetic nanoparticles are difficult to regulate via remote controlling whereas, when these nanoparticles are arrested inside polymeric matrices, the whole system become an artificial soft mussel like integrated system. Concurrently, these polymeric magnetic soft materials are also prone to response of external magnetic field (static or oscillatory). Additive manufacturing via spatial assembly of polymeric precursors followed by actuation like behaviour is quite a new manufacturing technique to fabricate magnetic soft materials. In this review, we focused on the magnetic nanoparticles and their entrapment into polymeric matrices and assessing their applicability in clinical (hyperthermia) as well as shape morphing behaviours. Both the behaviors …

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Jun 2022 • Annals of the Rheumatic Diseases 81 (Suppl 1), 488-488, 2022


S Kivity, H Kravitz, C Cohen, D Margoulis, M Amar, G Kazimirsky, D Ozeri, A Dori, C Brodie

Background Inflammatory myopathies (IM) are a heterogeneous group of disorders characterized by autoimmune inflammatory destruction of skeletal muscles. It is many times associated with lung, skin and joint involvement. Identifying biomarkers that can differentiate IM from other muscle disorders may elucidate the pathophysiology of IM, guide novel therapies, monitor disease activity/response to treatments and predict prognosis. Exosomes are membrane-bound nanovesicles with diameters of 30-150 nm that contain multiple proteins, nucleic acid, lipids and other molecules in a tissue- and cell-specific manner. Exosomes are secreted by a large variety of cells, play major roles in cell-cell interactions, and have recently emerged as circulating biomarkers in a variety of pathological conditions, including several autoimmune diseases.Objectives To characterize exosomes from serum of IM patients, analyze protein …

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Jun 2022 • Elsevier, 2022

SBS-based fiber sensors

A Zadok, X Bao, Z Yang, L Thevenaz

The spectra of Brillouin scattering processes in optical fibers are affected by temperature, axial strain, and other quantities of interest. This dependence forms the basis for optical Brillouin scattering based optical fiber sensors. Since the first proposition of such sensors in 1989, several protocols have been established for the spatially distributed analysis of Brillouin scattering spectra along fibers installed in structures of interest. Sensor systems cover hundreds of kilometers, reach sub-millimeter resolution, follow dynamic vibrations at MHz rates, and resolve sub-degree temperature changes and micro-strain elongations. Optical fiber sensors represent the most successful commercial application of Brillouin scattering physics to-date. This chapter reviews the principles, state of the art, performance trade-offs and recent breakthroughs in Brillouin scattering-based optical fiber sensors.

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Sourcing Herod the Great's calcite-alabaster bathtubs by a multi-analytic approach (vol 12, 7524, 2022)

Ayala Amir, Amos Frumkin, Boaz Zissu, Aren M Maeir, Gil Goobes, Amnon Albeck

Jun 2022 • Scientific Reports 12 (1), 14874, 2022

Passive symmetry breaking of the space–time propagation in cavity dissipative solitons

I Parshani, L Bello, M Meller, A Pe'er

Dissipative solitons are fundamental wave-pulses that preserve their form in the presence of periodic loss and gain. The canonical realization of dissipative solitons is Kerr-lens mode locking (KLM) in lasers, which delicately balance nonlinear and linear propagation in both time and space to generate ultrashort optical pulses. This linear-nonlinear balance dictates a unique pulse energy, which cannot be increased (say by elevated pumping), indicating that excess energy is expected to be radiated in the form of dispersive or diffractive waves. Here we show that KLM lasers can overcome this expectation. Specifically, by breaking the spatial symmetry between the forward and backward halves of the round-trip in a linear cavity, the laser can modify the soliton in space to incorporate the excess energy. Increasing the pump power leads therefore to a different soliton solution, rather than to dispersive/diffractive loss. We predict the symmetry breaking by a complete numerical simulation of the spatio-temporal dynamics in the cavity, and confirm it experimentally in a KLM Ti: Sapphire laser with quantitative agreement to the simulation. The simulation opens a window to directly observe the nonlinear space-time dynamics that molds the soliton pulse, and possibly to optimize it.

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Jun 2022 • Investigative Ophthalmology & Visual Science

Investigating the survival and function of retinal ganglion cells in an organotypic culture: An in-vitro model for studying synaptogenesis

Nairouz Farah, Efrat Simon, Yossi Mandel

Purpose: Stem cells replacement therapy is becoming a promising pursued avenue for vision restoration in people with degenerative diseases of the outer retina. However, the integration and survival of the transplanted cells and the formation of fully functioning synapses remain a challenge. Our aim is to develop an in-vitro experimental paradigm which will allow us to address these issues while working under experimentally controlled conditions and avoiding immune system reactions faced in-vivoMethods: As a first step, we are utilizing organotypic retinal cultures from transgenic rats expressing the calcium indicator GCaMP6f while monitoring the survival of the retinal ganglion cells (RGCs) using both extracellular recordings (multi electrode arrays), and calcium imaging at various time points.Results: Our calcium imaging revealed robust spontaneous activity of the RGCs up to 72hrs, albeit decreasing throughout …

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Jun 2022 • Biophysical Reports

PySOFI: an open source Python package for SOFI

Yuting Miao, Shimon Weiss, Xiyu Yi

Super-resolution optical fluctuation imaging (SOFI) is a highly democratizable technique that provides optical super-resolution without requirement of sophisticated imaging instruments. Easy-to-use open-source packages for SOFI are important to support the utilization and community adoption of the SOFI method, they also encourage the participation and further development of SOFI by new investigators. In this work, we developed PySOFI, an open-source Python package for SOFI analysis that offers the flexibility to inspect, test, modify, improve, and extend the algorithm. We provide complete documentation for the package and a collection of Jupyter Notebooks to demonstrate the usage of the package. We discuss the architecture of PySOFI and illustrate how to use each functional module. A demonstration on how to extend the PySOFI package with additional modules is also included in the PySOFI package. We …

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Jun 2022 • Sensors 22 (12), 4497, 2022

Recent Advances in Rapid and Highly Sensitive Detection of Proteins and Specific DNA Sequences Using a Magnetic Modulation Biosensing System

Shira Roth, Michael Margulis, Amos Danielli

In early disease stages, biomolecules of interest exist in very low concentrations, presenting a significant challenge for analytical devices and methods. Here, we provide a comprehensive overview of an innovative optical biosensing technology, termed magnetic modulation biosensing (MMB), its biomedical applications, and its ongoing development. In MMB, magnetic beads are attached to fluorescently labeled target molecules. A controlled magnetic force aggregates the magnetic beads and transports them in and out of an excitation laser beam, generating a periodic fluorescent signal that is detected and demodulated. MMB applications include rapid and highly sensitive detection of specific nucleic acid sequences, antibodies, proteins, and protein interactions. Compared with other established analytical methodologies, MMB provides improved sensitivity, shorter processing time, and simpler protocols.

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Jun 2022 • Talanta

High throughput optical modulation biosensing for highly sensitive and rapid detection of biomarkers

Shmuel Burg, Shira Roth, Meir Cohen, Shira Avivi-Mintz, Michael Margulis, Hanan Rohana, Avi Peretz, Amos Danielli

Rapid, highly sensitive, and high-throughput detection of biomarkers at low concentrations is invaluable for early diagnosis of various diseases. In many highly sensitive immunoassays, magnetic beads are used to capture fluorescently labeled target molecules. The target molecules are then quantified by detecting the fluorescent signal from individual beads, which is time consuming and requires a complicated and expensive detection system. Here, we demonstrate a high-throughput optical modulation biosensing (ht-OMB) system, which uses a small permanent magnet to aggregate the beads into a small detection volume and eliminates background noise by steering a laser beam in and out of the cluster of beads. Shortening the aggregation, acquisition, and well-to-well scanning transition times enables reading a 96-well plate within 10 minutes. Using the ht-OMB system to detect human Interleukin-8, we …

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Jun 2022 • 2022 International Conference Laser Optics (ICLO), 01-01, 2022

Immunoglobulin-based hybrid targeted nanoagents for in vitro and in vivo multimodal imaging

AV Lunin, ES Korenkov, T Sadan, R Popovtzer, EN Mochalova, VR Cherkasov

Nanomedicine constantly broadens horizons of modern therapy and diagnostics. However, imaging nanoagents are of especial interest. Here, we report on novel, facile, and sustainable way to fabricate targeted multimodal imaging nanoparticles. Specifically, we synthesize nanoparticles using immunoglobulins and introduce nanoparticles of different nature into immunoglobulin-based matrix. We demonstrate applicability of the nanoparticles both in vitro and in vivo.

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Jun 2022 • ACS Applied Materials & Interfaces

On the Practical Applications of the Magnesium Fluorinated Alkoxyaluminate Electrolyte in Mg Battery Cells

Tjaša Pavčnik, Matic Lozinšek, Klemen Pirnat, Alen Vizintin, Toshihiko Mandai, Doron Aurbach, Robert Dominko, Jan Bitenc

High-performance electrolytes are at the heart of magnesium battery development. Long-term stability along with the low potential difference between plating and stripping processes are needed to consider them for next-generation battery devices. Within this work, we perform an in-depth characterization of the novel Mg[Al(hfip)4]2 salt in different glyme-based electrolytes. Specific importance is given to the influence of water content and the role of additives in the electrolyte. Mg[Al(hfip)4]2-based electrolytes exemplify high tolerance to water presence and the beneficial effect of additives under aggravated cycling conditions. Finally, electrolyte compatibility is tested with three different types of Mg cathodes, spanning different types of electrochemical mechanisms (Chevrel phase, organic cathode, sulfur). Benchmarking with an electrolyte containing a state-of-the-art Mg[B(hfip)4]2 salt exemplifies an improved …

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Sourcing Herod the Great's calcite-alabaster bathtubs by a multi-analytic approach (vol 12, 7524, 2022)

Ayala Amir, Amos Frumkin, Boaz Zissu, Aren M Maeir, Gil Goobes, Amnon Albeck

Jun 2022 • Bulletin of the American Physical Society

Multichannel nature of Efimov physics with ultracold 7Li atoms

Jose D'Incao, Yaakov Yudkin, Paul Julienne, Lev Khaykovich

We present our current understanding of various aspects of Efimov physics originating from the complex multichannel hyperfine structure and overlap of Feshbach resonances for 7Li atoms. This further help us to explain puzzling experimental observations with ultracold gases. We have characterized the energies of Efimov states and corresponding interference and resonance scattering phenomena associated to them as a function of an external magnetic field. Our results also indicate that Efimov states in the 7Li system can have a unique mixed hyperfine character which strongly affect their near-threshold behavior for repulsive interatomic interactions.[1] Y. Yudkin, R. Elbaz, L. Khaykovich, arXiv: 2004.02723.

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