Neural Mechanisms of Feeding Behavior and Its Disorders

There are two forms of feeding behavior. The hypothalamus and the lower brainstem monitor the internal environment of the body and are involved in the control of feeding behavior to maintain energy balance and homeostasis (homeostasis-dependent feeding behavior). On the other hand, humans and animals, when placed in an environment similar to modern society (e.g., cafeterias), where organisms can easily ingest highly preferred foods, consume more than necessary (homeostasis-independent feeding behavior). The emotion/reward system, including the amygdala and nucleus accumbens, is involved in this type of feeding behavior. These two control systems interact in the lateral hypothalamic area (LHA), where feeding behavior is controlled by systems with higher activity. In modern society, there is abundant information on food, and high-calorie foods such as snacks are readily available. Thus, in modern society, the homeostasis-independent control system easily surpasses the homeostasis-dependent control system, which results in obesity. Various feeding and eating disorders might be ascribed to dysregulations in the two control systems. In the future, more effective treatments for feeding and eating disorders can be developed by elucidating the mechanisms of these two control systems

Evaluator of adaptability of S. cerevisiae to grape juice using the oversxpression profiling ADOPT method

The authors have recently developed the overexpression profiling ADOPT method. In the ADOPT method, yeast strains overexpressing most of the genes in the budding yeast Saccharomyces cerevisiae genome are mixed and competitively cultured, and the genes overexpressed in the enriched strains are systematically identified. Furthermore, the identified genes can be used to identify bottleneck factors that are necessary but lacking for growth of S. cerevisiae under given conditions. In our previous studies, we have identified bottlenecks in artificially created stress environments in the laboratory, but in this study, we used grape juice for winemaking as an example to see if industrial bottlenecks can be identified. ADOPT experiments with sulfite-added grape juice used in conventional winemaking resulted in a strong enrichment of strains overexpressing the sulfite pump SSU1 and its transcription factor FZF1. Since enhancement of SSU1 function is known to occur in wine yeast acclimation, ADOPT was also shown to be useful in the search for industrial bottlenecks. On the other hand, no genes were strongly enriched by ADOPT in grape juice without sulfite addition, suggesting that grape juice is a balanced medium with few bottlenecks for S. cerevisiae growth.筆者らは最近，過剰発現プロファイリングADOPT 法を開発した．ADOPT 法では，出芽酵母Saccharomyces cerevisiae ゲノムのほとんどの遺伝子をそれぞれ過剰発現する酵母株を混合・競合培養し，その過程で濃縮されてきた株が過剰発現している遺伝子を体系的に同定する．さらに同定された遺伝子をたよりに，S. cerevisiae の与えられた条件での増殖に必要だが欠落しているボトルネック因子を明らかにできる．これまでの研究では，実験室で人為的に構築したストレス環境でのボトルネックの同定を行ってきたが，本研究では産業上のボトルネックを明らかにできるかをワイン醸造用のブドウ果汁を例として検証した．通常のワイン醸造に用いられる亜硫酸添加ブドウ果汁でのADOPT 実験は，亜硫酸ポンプSSU1とその転写因子FZF1の過剰発現株が強く濃縮された．SSU1機能の強化はワイン用酵母の馴養でも起きることが知られていることから，産業上のボトルネックを探索する際にもADOPT が有効であることが示された．一方，亜硫酸添加のないブドウ果汁ではADOPT で強く濃縮された遺伝子は見られず，ブドウ果汁はS. cerevisiae の増殖にとってボトルネックの少ないバランスのとれた培地であることが示唆された

Torsion-induced persistent current in a twisted quantum ring

We describe the effects of geometric torsion on the coherent motion of electrons along a thin twisted quantum ring. The geometric torsion inherent in the quantum ring triggers a quantum phase shift in the electrons' eigenstates, thereby resulting in a torsion-induced persistent current that flows along the twisted quantum ring. The physical conditions required for detecting the current flow are discussed.Comment: 9 pages, 3 figure

歯科インプラント動揺測定装置の開発

Evaluation of dental implantation is very important because it gives useful information for both planning the dental treatment and evaluating of prognosis. This study aimed at improving our previously developed Tooth Mobility (TM) tester and developing a dental implant movement (IM) checker. The measuring probe included a bimorph transducer of two piezoelectric elements. It was actuated by single frequency and detected tooth acceleration. The acceleration signal was processed and the IM score was calculated in PC. Two artificial implant models in which IMZ implant was buried with different elasticity of surrounding (molteno(@)) were used to examine the performance of the IM checker. The IM scores obtained in the models were 29 and 58. The measurement time was below 15 seconds. The average of measurement variation of one operator was below 6% and the average variation among five operators was below also 6%. The IM checker reduced a measurement variation by 51% and a measuring time by 61% compared with those of the TM tester in natural teeth. The newly developed IM checker had sufficient measuring reliability and we could objectively estimate the implant movement in dental clinics.臨床歯科において，歯の動揺度診査が日常的に行われているのと同じように，近年行われるようになってきた歯科インプラント施術においても，その植立評価は重要である。歯の動揺は，歯の治療計画において，また予後の評価においても重要な情報を与えてくれる。本研究では，その植立評価を行うために，インプラントの動揺に着目した。動揺を簡便にかつ定量的に測定するために，著者らがすでに開発したT－Mテスタ（Tooth Mobility tester）を改良して，IMチェッカ（Implant Mobility Checker）を開発した。IMチェッカは測定プローブと増幅器などのインタフェース，演算処理用のノートパソコンから構成される。測定プローブは圧電素子を2枚重ねたバイモルフ構造で，単一周波数の振動駆動と加速度検出を行い，口腔内でも測定ができるほどに小型に設計した。ノートパソコンでは得られた加速度信号をデータ処理し，IM値を算出する。IM値は，測定周波数と駆動力が一 定の場合，インプラント周囲の機械モビリティに比例するので，インプラントの動揺を数値化することができる。内可動性機構をもつIMZタイプのインプラントを埋植したモデルを製作し，そのIM値を測定した。インプラント周囲の材料（モルテノ(@)）の硬さを変えた2種類のモデルを作製したところ，歯科医による臨床的動揺度診査はいずれもM0であったが，本チェッカによってその動揺の差を測定したところ，IM値は29と58となり，客観的に動揺の差を評価することができた。試作したIMチェッカで測定したところ，一歯の測定時間は約15秒以下であり，また測定のばらつきは術者内で平均6％以下，また術者間で6％以下であった。一方，従来のアナログ型T－Mテスタと比較したところ，天然歯の測定において，測定のばらつきは51％，測定時間は61％減少させることができた。従って，IMチェッカは十分な測定精度を確保できており，今後，臨床での試用を行いたいと考える

手関節伸展荷重時の遠位橈尺関節の3次元動態解析

PURPOSE: To assess the wrist joints of healthy volunteers in extended and loaded states versus the unloaded state by using computed tomography (CT) to analyze the in vivo 3-dimensional movements in the distal radioulnar joint (DRUJ). METHODS: The dominant arms of 9 volunteers with healthy wrists were studied. We mounted a compression device onto the elbows in an inverted position. A 0-kg and 7-kg load each was applied during low-dose radiation CT imaging and a bone model was produced. We marked the insertion sites for the 4 radioulnar ligaments stabilizing the DRUJ: palmar superficial radioulnar ligament (PS-RUL), dorsal superficial radioulnar ligament (DS-RUL), dorsal deep radioulnar ligament (DD-RUL), and palmar deep radioulnar ligament (PD-RUL). Using Marai's method, each ligament was virtualized and the length of each simulated ligament was measured. We also computed the 3-dimensional displacement and corresponding rotation of the distal ulna where it comes into contact with the radius in the sigmoid notch. RESULTS: The lengths of palmar ligaments (PS-RUL and PD-RUL) increased significantly under loaded conditions, and although not significant, the length of dorsal ligaments (DS-RUL and DD-RUL) tended to increase. When the wrist was loaded, the ulna rotated toward the open palmar side. CONCLUSIONS: The length of simulated radioulnar ligaments increased when the wrist joint was loaded in an extended position. This kinematic movement of DRUJ separation under a loading condition is different from physiological active movement. CLINICAL RELEVANCE: The 3-dimensional kinematic analysis revealed that palmar radioulnar ligaments were stretched during axial loading, suggesting that a tear of the palmer ligament can result from a fall on an outstretched hand.博士（医学）・甲第704号・平成31年3月15日© 2019 by the American Society for Surgery of the Hand. All rights reserved

Magnetic Properties of Ternary DyMn_2X_2 Compounds (X=Si and Ge)(Magnetism)

Magnetic properties of DyMn_2Si_2, DyMn_2Ge_2 and their mixed compounds DyMn_2(Si_Ge_x)_2, which display a variety of interesting magnetic behaviors originating in competing magnetic interactions and anisotropy, have been investigated systematically by magnetization mesurements ^Dy Mossbauer spectroscopy and neutron diffraction experiments. This report presents a review of the results mainly obtained by the magnetization measurements

Neuronal response sto face-like and facial stimuli in the monkey superior colliculus

The superficial layers of the superior colliculus (sSC) appear to function as a subcortical visual pathway that bypasses the striate cortex for the rapid processing of coarse facial information. We investigated the responses of neurons in the monkey sSC during a delayed non-matching-to-sample (DNMS) task in which monkeys were required to discriminate among five categories of visual stimuli [photos of faces with different gaze directions, line drawings of faces, face-like patterns (three dark blobs on a bright oval), eye-like patterns, and simple geometric patterns]. Of the 605 sSC neurons recorded, 216 neurons responded to the visual stimuli. Among the stimuli, face-like patterns elicited responses with the shortest latencies. Low-pass filtering of the images did not influence the responses. However, scrambling of the images increased the responses in the late phase, and this was consistent with a feedback influence from upstream areas. A multidimensional scaling (MDS) analysis of the population data indicated that the sSC neurons could separately encode face-like patterns during the first 25-ms period after stimulus onset, and stimulus categorization developed in the next three 25-ms periods. The amount of stimulus information conveyed by the sSC neurons and the number of stimulus-differentiating neurons were consistently higher during the 2nd to 4th 25-ms periods than during the first 25-ms period. These results suggested that population activity of the sSC neurons preferentially filtered face-like patterns with short latencies to allow for the rapid processing of coarse facial information and developed categorization of the stimuli in later phases through feedback from upstream areas

Population coding of facial information in the monkey superior colliculus and pulvinar

The superior colliculus (SC) and pulvinar are thought to function as a subcortical visual pathway that bypasses the striate cortex and detects fundamental facial information. We previously investigated neuronal responses in the SC and pulvinar of monkeys during a delayed nonmatching-to-sample task, in which the monkeys were required to discriminate among 35 facial photos of five models and other categories of visual stimuli, and reported that population coding by multiple SC and pulvinar neurons well discriminated facial photos from other categories of stimuli (Nguyen et al., 2013, 2014). However, it remains unknown whether population coding could represent multiple types of facial information including facial identity, gender, facial orientation, and gaze direction. In the present study, to investigate population coding of multiple types of facial information by the SC and pulvinar neurons, we reanalyzed the same neuronal responses in the SC and pulvinar; the responses of 112 neurons in the SC and 68 neurons in the pulvinar in serial 50-ms epochs after stimulus onset were reanalyzed with multidimensional scaling (MDS). The results indicated that population coding by neurons in both the SC and pulvinar classified some aspects of facial information, such as face orientation, gender, and identity, of the facial photos in the second epoch (50–100 ms after stimulus onset). The Euclidean distances between all the pairs of stimuli in the MDS spaces in the SC were significantly correlated with those in the pulvinar, which suggested that the SC and pulvinar function as a unit. However, in contrast with the known population coding of face neurons in the temporal cortex, the facial information coding in the SC and pulvinar was coarse and insufficient. In these subcortical areas, identity discrimination was face orientation-dependent and the left and right profiles were not discriminated. Furthermore, gaze direction information was not extracted in the SC and pulvinar. These results suggest that the SC and pulvinar, which comprise the subcortical visual pathway, send coarse and rapid information on faces to the cortical system in a bottom-up process