Three‐Dimensional Closure of Field‐Aligned Currents in the Polar Ionosphere

Using a simplified three-dimensional Hall-magnetohydrodynamics simulation, we investigated the current closure of field-aligned currents (FACs) in the polar ionosphere. Ion-neutral collision was taken into consideration. To excite a pair of FACs, an electric field perturbation is applied to the upper boundary of the simulation box. The flow shear propagated downward accompanied with the FACs. When the electron density was initially uniform, most of the FACs are connected with the Pedersen current due to electrostatic processes. Some of them are connected with the Hall current due to inductive processes. When the density was initially enhanced in a longitudinally elongated region (high-density band), overflow of the Hall current takes place near the edge of the high-density band. Additionally, localized FACs appear to bridge between the Pedersen current layer (high altitude) and the Hall current layer (low altitude). The formation of the additional FACs is closely associated with the field-aligned gradient of ∇∙E, where E is the electric field. We compared the current lines with those evaluated by the traditional thin-layer assumption. The current closure obtained by the thin-layer assumption is fully different from that obtained by the three-dimensional model. In the full three-dimensional simulation, a current line flowing in the Hall layer can pass underneath the current flowing in the Pedersen layer. Such “intersection” is not allowed in the thin-layer assumption. We believe that the three-dimensional model offers advantages for fully understanding the closure of the FACs together with the current closure on the magnetospheric side

Tissue damage in the canine normal esophagus by photoactivation with talaporfin sodium (laserphyrin): a preclinical study.

[Background] Treatment failure at the primary site after chemoradiotherapy is a major problem in achieving a complete response. Photodynamic therapy (PDT) with porfimer sodium (Photofrin®) has some problems such as the requirement for shielding from light for several weeks and a high incidence of skin phototoxicity. PDT with talaporfin sodium (Laserphyrin) is less toxic and is expected to have a better effect compared with Photofrin PDT. However, Laserphyrin PDT is not approved for use in the esophagus. In this preclinical study, we investigated tissue damage of the canine normal esophagus caused by photoactivation with Laserphyrin. [Methodology/Principal Findings] Diode laser irradiation was performed at 60 min after administration. An area 5 cm oral to the esophagogastric junction was irradiated at 25 J/cm2, 50 J/cm2, and 100 J/cm2 using a three-step escalation. The irradiated areas were evaluated endoscopically on postirradiation days 1 and 7, and were subjected to histological examination after autopsy. The areas injured by photoactivation were 52 mm2, 498 mm2, and 831 mm2 after irradiation at 25 J/cm2, 50 J/cm2, and 100 J/cm2, respectively. Tissue injury was observed in the muscle layer or even deeper at any irradiation level and became more severe as the irradiation dose increased. At 100 J/cm2 both inflammatory changes and necrosis were seen histologically in extra-adventitial tissue. [Conclusions/Significance]To minimize injury of the normal esophagus by photoactivation with Laserphyrin, diode laser irradiation at 25 J/cm2 appears to be safe. For human application, it would be desirable to investigate the optimal laser dose starting from this level

JRAB/MICAL-L2 undergoes liquid–liquid phase separation to form tubular recycling endosomes

Elongated tubular endosomes play essential roles in diverse cellular functions. Multiple molecules have been implicated in tubulation of recycling endosomes, but the mechanism of endosomal tubule biogenesis has remained unclear. In this study, we found that JRAB/MICAL-L2 induces endosomal tubulation via activated Rab8A. In association with Rab8A, JRAB/MICAL-L2 adopts its closed form, which functions in the tubulation of recycling endosomes. Moreover, JRAB/MICAL-L2 induces liquid–liquid phase separation, initiating the formation of tubular recycling endosomes upon overexpression. Between its N-terminal and C-terminal globular domains, JRAB/MICAL-L2 contains an intrinsically disordered region, which contributes to the formation of JRAB/MICAL-L2 condensates. Based on our findings, we propose that JRAB/MICAL-L2 plays two sequential roles in the biogenesis of tubular recycling endosomes: first, JRAB/MICAL-L2 organizes phase separation, and then the closed form of JRAB/MICAL-L2 formed by interaction with Rab8A promotes endosomal tubulation

Equilibrium Analysis of Location and Bid Rent Curve

本稿の主要な目的は付け値曲線についてのいくつかのアプローチを展望することである。付け値曲線は都市経済学での立地点の決定において重要な役割を果たしている。しかし，住宅立地や産業立地，立地政策の基本概念にもかかわらず付け値曲線についての明快で統一的説明は少ない｡チューネンは輸送費用の相違により市場を中心とした同心円状の地域ごとに土地の利用形態と地代の決定構造が異なることを発見した｡チューネンの先駆的業績は長い間無視されてきた。アロンゾはチューネンの理論を再構成し，付け値理論を交通費用と絡めながら現代的な都市空間構造の分析に適用することに成功した。以来，都市エリア内における競争的な立地パターンの決定を説明する際にこの付け値を用いた分析手法が援用されることになった。本稿の最初の部分はアロンゾ以降の付け値理論のサーベイを行い，各論者のモデルの特徴を明確にし，さらにミクロの消費者行動理論の中で付け値曲線を導出する。付け値関数やその性質についての消費者行動の理論を用いた証明，並びに市場均衡モデルによる均衡立地点の導出を行う。次いで静学的分析の中で，モデル内のパラメータの変化が家計の立地行動に及ぼす影響を検討する｡最後にモデルの中に租税変数として固定資産税を導入して住宅立地に与える効果を検討する。The main purpose of this note is to review some approaches of the bid rent curve which plays an important role in determinimg a location site in urban economics. Although the bid rent curve is a fundamental concept in residential and industrial location and location policy, we have not seen a clear and systematic explanation about the bid rent curve. The first theoretical study was done by Thünen. He devised the bid rent in the competitive agricultural rent, but he did not refer to the housing location. Thünen\u27s pioneering theory was disregarded for a long time in economics. Alonso revived Thünen\u27s theory in solving the urban location paradox which says that the poor live in the center district of high land price and the rich live in surrounding area of cheap land price. Alonso\u27s analysis is the substantial starting point of modem bid rent theory in urban economics. The first section of the note presents a survey of the main models about the bid rent curve since Alonso. We examine some models of the bid rent analysis and show the feature of each model. In the second section of the note, we explain the bid rent curve in a general context using household behavior in microeconomics. The last section refers to policy aspects. We propose a housing location model with tax parameter, in which we try to analyze the effect of the property tax in relation to the housing policy

Goreisan Inhibits Upregulation of Aquaporin 4 and Formation of Cerebral Edema in the Rat Model of Juvenile Hypoxic-Ischemic Encephalopathy

Secondary cerebral edema regulation is of prognostic significance in hypoxic-ischemic encephalopathy (HIE), and aquaporin 4 (AQP4) plays an important role in the pathogenesis of cerebral edema. The traditional Japanese herbal medicine Goreisan relieves brain edema in adults; however, its effect and pharmacological mechanism in children are unknown. We investigated the effects of Goreisan on HIE-associated brain edema and AQP4 expression in a juvenile rat model, established by combined occlusion of middle cerebral and common carotid arteries. Magnetic resonance imaging showed that the lesion areas were significantly smaller in the Goreisan- (2 g/kg) treated group than in the nontreated (saline) group at 24 and 48 h postoperatively. AQP4 mRNA levels in the lesion and nonlesion sides were significantly suppressed in the Goreisan group compared with the nontreated group 36 h postoperatively. Western blotting revealed that levels of AQP4 protein were significantly decreased in the Goreisan group compared with the nontreated group in the lesion side 72 h postoperatively, but not at 12 or 36 h. After 14 days, the Goreisan group had a significantly better survival rate. These findings suggest that Goreisan suppresses brain edema in HIE and improves survival in juvenile rats, possibly via regulation of AQP4 expression and function

Use of the Hydrogen Breath Test to Determine the Influence of Antibiotic Prophylaxis on Intestinal Flora

Purpose: This experimental study was designed to use the hydrogen (H2) breath test to investigate changes in the intestinal flora of patients that were administered prophylactic antibiotics for 48 hours after surgery. Methods: Altogether, 22 patients were divided into two groups and the antimicrobial prophylactics, cefazolin (3.0 g/day) or sulbactam/ampicillin (4.5 g/day), were administered on induction of anaesthesia for 48 hours after surgery. End expiratory breath samples were collected on the morning of the day of surgery and every morning for 1-6 days after surgery. Results: H2 breath concentration significantly decreased in each group on day 1 (cefazolin: 1.20 ± 0.39 ppm vs. sulbactam/ampicillin: 1.17 ± 0.34 ppm). On day 2, the H2 concentration in the sulbactam/ampicillin group was significantly lower than the cefazolin group (cefazolin: 6.4 ± 2.2 ppm vs. sulbactam/ampicillin: 1.0 ± 0.4 ppm, p < 0.05). H2 concentration was still lower in the sulbactam/ampicillin group (1.3 ± 0.3 ppm vs. 3.3 ± 1.0 ppm, p = 0.10) on day 3. On days 4-6, H2 concentration was essentially the same for both groups. Discussion: Colonic anaerobes are thought to be a reservoir of resistant organisms and prolonged antimicrobial treatment is a major cause for the development of resistance. Surgical prophylaxis is basically recommended for use within 24 hours after surgery. The breath H2 concentration in both groups significantly decreased 24 hours after administration. These results suggest that both antibiotics influence the activity of colonic anaerobes and the duration of surgical antibiotic prophylaxis should be as short as possible

Gamma Ray Spectra from Thermal Neutron Capture on Gadolinium-155 and Natural Gadolinium

Abstract Natural gadolinium is widely used for its excellent thermal neutron capture cross section, because of its two major isotopes: $^{\rm 155}$Gd and $^{\rm 157}$Gd. We measured the $\gamma$-ray spectra produced from the thermal neutron capture on targets comprising a natural gadolinium film and enriched $^{\rm 155}$Gd (in Gd$_{2}$O$_{3}$ powder) in the energy range from 0.11 MeV to 8.0 MeV, using the ANNRI germanium spectrometer at MLF, J-PARC. The freshly analyzed data of the $^{\rm 155}$Gd($n, \gamma$) reaction are used to improve our previously developed model (ANNRI-Gd model) for the $^{\rm 157}$Gd($n, \gamma$) reaction [K. Hagiwara et al. [ANNRI-Gd Collaboration], Prog. Theor. Exp. Phys. 2019, 023D01 (2019)], and its performance confirmed with the independent data from the $^{\rm nat}$Gd($n, \gamma$) reaction. This article completes the development of an efficient Monte Carlo model required to simulate and analyze particle interactions involving the thermal neutron captures on gadolinium in any relevant future experiments