104 research outputs found
Uniform Confidence Band for Optimal Transport Map on One-Dimensional Data
We develop a statistical inference method for an optimal transport map
between distributions on real numbers with uniform confidence bands. The
concept of optimal transport (OT) is used to measure distances between
distributions, and OT maps are used to construct the distance. OT has been
applied in many fields in recent years, and its statistical properties have
attracted much interest. In particular, since the OT map is a function, a
uniform norm-based statistical inference is significant for visualization and
interpretation. In this study, we derive a limit distribution of a uniform norm
of an estimation error for the OT map, and then develop a uniform confidence
band based on it. In addition to our limit theorem, we develop a smoothed
bootstrap method with its validation and guarantee on an asymptotic coverage
probability of the confidence band. Our proof is based on the functional delta
method and the representation of OT maps on the reals.Comment: 34 page
Dispersion cancellation in high resolution two-photon interference
The dispersion cancellation observed in Hong-Ou-Mandel (HOM) interference
between frequency-entangled photon pairs has been the basis of quantum optical
coherence tomography and quantum clock synchronization. Here we explore the
effect of phase dispersion on ultranarrow HOM dips. We show that the
higher-order dispersion, the line width of the pump laser, and the spectral
shape of the parametric fluorescence have a strong effect on the dispersion
cancellation in the high-resolution regime with several experimental
verifications. Perfect dispersion cancellation with a linewidth of 3\mu m is
also demonstrated through 25 mm of water.Comment: 6 pages, 6 figure
In vitro production of L-cysteine using thermophilic enzymes
L-Cysteine (L-Cys) is a commercially important amino acid and widely used in food, pharmaceutical, and cosmetic industries. Commercial production of L-Cys has long been done by an acid-hydrolysis of human hair and animal feather, leading to the generation of a large quantity of hazardous wastes. Although several biotechnology companies have recently launched a fermentative production of L-Cys using engineered bacteria, these processes suffer from the low product titer mainly due to the cytotoxic effect of L-Cys. To provide an alternative approach for the commercial production of L-Cys, we aimed at the development of a non-fermentative, in vitro manufacturing system using thermophilic enzymes. In this system, enzymes from (hyper)thermophilic bacteria and archaea were assembled to construct an in vitro synthetic pathway for the one-pot conversion of glucose to L-Cys (Figure 1). By using experimentally optimized concentrations of enzymes, L-Cys could be produced at a rate of 0.9 g/L/h with a molar conversion yield of 25%.
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Isotropic orbital magnetic moments in magnetically anisotropic SrRuO3 films
Epitaxially strained SrRuO3 films have been a model system for understanding
the magnetic anisotropy in metallic oxides. In this paper, we investigate the
anisotropy of the Ru 4d and O 2p electronic structure and magnetic properties
using high-quality epitaxially strained (compressive and tensile) SrRuO3 films
grown by machine-learning-assisted molecular beam epitaxy. The element-specific
magnetic properties and the hybridization between the Ru 4d and O 2p orbitals
were characterized by Ru M2,3-edge and O K-edge soft X-ray absorption
spectroscopy and X-ray magnetic circular dichroism measurements. The
magnetization curves for the Ru 4d and O 2p magnetic moments are identical,
irrespective of the strain type, indicating the strong magnetic coupling
between the Ru and O ions. The electronic structure and the orbital magnetic
moment relative to the spin magnetic moment are isotropic despite the
perpendicular and in-plane magnetic anisotropy in the compressive-strained and
tensile-strained SrRuO3 films; i.e., the orbital magnetic moments have a
negligibly small contribution to the magnetic anisotropy. This result
contradicts Bruno model, where magnetic anisotropy arises from the difference
in the orbital magnetic moment between the perpendicular and in-plane
directions. Contributions of strain-induced electric quadrupole moments to the
magnetic anisotropy are discussed, too
Prevention of esophageal strictures after endoscopic submucosal dissection
Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have recently been accepted as less invasive methods for treating patients with early esophageal cancers such as squamous cell carcinoma and dysplasia of Barrett\u27s esophagus. However, the large defects in the esophageal mucosa often cause severe esophageal strictures, which dramatically reduce the patient\u27s quality of life. Although preventive endoscopic balloon dilatation can reduce dysphagia and the frequency of dilatation, other approaches are necessary to prevent esophageal strictures after ESD. This review describes several strategies for preventing esophageal strictures after ESD, with a particular focus on anti-inflammatory and tissue engineering approaches. The local injection of triamcinolone acetonide and other systemic steroid therapies are frequently used to prevent esophageal strictures after ESD. Tissue engineering approaches for preventing esophageal strictures have recently been applied in basic research studies. Scaffolds with temporary stents have been applied in five cases, and this technique has been shown to be safe and is anticipated to prevent esophageal strictures. Fabricated autologous oral mucosal epithelial cell sheets to cover the defective mucosa similarly to how commercially available skin products fabricated from epidermal cells are used for skin defects or in cases of intractable ulcers. Fabricated autologous oralmucosal- epithelial cell sheets have already been shown to be safe
Differentiation of multipotent neural stem cells derived from Rett syndrome patients is biased toward the astrocytic lineage
Generation of broadband spontaneous parametric fluorescence using multiple bulk nonlinear crystals
We propose a novel method for generating broadband spontaneous parametric fluorescence by using a set of bulk nonlinear crystals (NLCs). We also demonstrate this scheme experimentally. Our method employs a superposition of spontaneous parametric fluorescence spectra generated using multiple bulk NLCs. A typical bandwidth of 160 nm (73 THz) with a degenerate wavelength of 808 nm was achieved using two β-barium-borate (BBO) crystals, whereas a typical bandwidth of 75 nm (34 THz) was realized using a single BBO crystal. We also observed coincidence counts of generated photon pairs in a non-collinear configuration. The bandwidth could be further broadened by increasing the number of NLCs. Our demonstration suggests that a set of four BBO crystals could realize a bandwidth of approximately 215 nm (100 THz). We also discuss the stability of Hong-Ou-Mandel two-photon interference between the parametric fluorescence generated by this scheme. Our simple scheme is easy to implement with conventional NLCs and does not require special devices
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