Optical phase conjugation with less than a photon per degree of freedom

We demonstrate experimentally that optical phase conjugation can be used to focus light through strongly scattering media even when far less than a photon per optical degree of freedom is detected. We found that the best achievable intensity contrast is equal to the total number of detected photons, as long as the resolution of the system is high enough. Our results demonstrate that phase conjugation can be used even when the photon budget is extremely low, such as in high-speed focusing through dynamic media, or imaging deep inside tissue

Interpolation function of the genocchi type polynomials

The main purpose of this paper is to construct not only generating functions of the new approach Genocchi type numbers and polynomials but also interpolation function of these numbers and polynomials which are related to a, b, c arbitrary positive real parameters. We prove multiplication theorem of these polynomials. Furthermore, we give some identities and applications associated with these numbers, polynomials and their interpolation functions.Comment: 14 page

Model-Based Edge Detector for Spectral Imagery Using Sparse Spatiospectral Masks

Two model-based algorithms for edge detection in spectral imagery are developed that specifically target capturing intrinsic features such as isoluminant edges that are characterized by a jump in color but not in intensity. Given prior knowledge of the classes of reflectance or emittance spectra associated with candidate objects in a scene, a small set of spectral-band ratios, which most profoundly identify the edge between each pair of materials, are selected to define a edge signature. The bands that form the edge signature are fed into a spatial mask, producing a sparse joint spatiospectral nonlinear operator. The first algorithm achieves edge detection for every material pair by matching the response of the operator at every pixel with the edge signature for the pair of materials. The second algorithm is a classifier-enhanced extension of the first algorithm that adaptively accentuates distinctive features before applying the spatiospectral operator. Both algorithms are extensively verified using spectral imagery from the airborne hyperspectral imager and from a dots-in-a-well midinfrared imager. In both cases, the multicolor gradient (MCG) and the hyperspectral/spatial detection of edges (HySPADE) edge detectors are used as a benchmark for comparison. The results demonstrate that the proposed algorithms outperform the MCG and HySPADE edge detectors in accuracy, especially when isoluminant edges are present. By requiring only a few bands as input to the spatiospectral operator, the algorithms enable significant levels of data compression in band selection. In the presented examples, the required operations per pixel are reduced by a factor of 71 with respect to those required by the MCG edge detector

Magnetic Domain Patterns Depending on the Sweeping Rate of Magnetic Fields

The domain patterns in a thin ferromagnetic film are investigated in both experiments and numerical simulations. Magnetic domain patterns under a zero field are usually observed after an external magnetic field is removed. It is demonstrated that the characteristics of the domain patterns depend on the decreasing rate of the external field, although it can also depend on other factors. Our numerical simulations and experiments show the following properties of domain patterns: a sea-island structure appears when the field decreases rapidly from the saturating field to the zero field, while a labyrinth structure is observed for a slowly decreasing field. The mechanism of the dependence on the field sweeping rate is discussed in terms of the concepts of crystallization.Comment: 4 pages, 3 figure

Editorial: Biology of stress granules in plants

Eukaryotic cells have developed sophisticated mechanisms to survive under ever-changing environments which include compartmentalization of translationally arrested mRNA molecules and proteins into a type of membraneless cytoplasmic foci called stress granules (SGs). Stress granules were first identified as phase-dense cytoplasmic particles formed in mammalian cells when subjected to heat shock (Arrigo et al., 1988). To date, intensive studies in yeast and animal model systems have helped elucidate the major molecular composition of SGs (Jain et al., 2016; Markmiller et al., 2018; Marmor-Kollet et al., 2020). SGs are typically consisted of small ribosomal subunits, various translation initiation factors (eIFs), poly(A)-binding proteins (PABs), and a variety of RNA-binding proteins (RBPs) and non-RNA-binding proteins. Although SGs were initially thought to facilitate mRNA translational arrest during stress, it has been well-documented that SGs play a more active role in stress response, mRNA triage and stress signaling, among other processes (Hofmann et al., 2021). The mechanisms governing the assembly of SGs have been recently extensively discussed (Schmit et al., 2021). Growing evidence have now suggested that SGs can be classified as droplets formed by liquid-liquid phase separation (LLPS) in the cytoplasm (Jain et al., 2016; Yang et al., 2020). In contrast to mammalian or yeast model system, research in the plant SGs field is still in its infancy. Despite very recent works that have begun to provide a better understanding on some of the mechanistic questions, the investigation of plant SGs still represents an emerging field. Therefore, numerous knowledge gaps remain to be filled. Here, we share with the plant biology community a Research Topic that aims to highlight the most current findings in the field of SG biology in plants.USA National Science Foundation MCB-1906060Ohio Agricultural Research and Development Center OHOA1627Ministerio de Ciencia e Innovación (MICIN). España PID2020-119737GA-I0

Permutation sampling in Path Integral Monte Carlo

A simple algorithm is described to sample permutations of identical particles in Path Integral Monte Carlo (PIMC) simulations of continuum many-body systems. The sampling strategy illustrated here is fairly general, and can be easily incorporated in any PIMC implementation based on the staging algorithm. Although it is similar in spirit to an existing prescription, it differs from it in some key aspects. It allows one to sample permutations efficiently, even if long paths (e.g., hundreds, or thousands of slices) are needed. We illustrate its effectiveness by presenting results of a PIMC calculation of thermodynamic properties of superfluid Helium-four, in which a very simple approximation for the high-temperature density matrix was utilized