A common subcortical oscillatory network contributes to recovery after spinal cord injury

Recent studies in monkeys showed that when the direct cortico-motoneuronal connection was transected at mid-cervical segments, remaining, indirect cortico-motoneuronal pathways compensated for finger dexterity within one to three months. To elucidate the changes in dynamic properties of neural circuits during the recovery, we investigated the cortico-muscular and inter-muscular couplings of activities throughout the recovery course. Activities of antagonist muscle pairs showed co-activation during the second postoperative week, and oscillated coherently at frequencies of 30-46 Hz (gamma-band) by one month postoperatively. Such gamma-band inter-muscular coherence was not observed preoperatively, but became prominent and distributed widely over proximal and distal muscles with the recovery. Neither the gamma-band cortico-muscular coupling (14-30 Hz) observed before lesion, nor a gamma-band oscillation was observed in bilateral motor cortex after lesion. Thus, we propose that an unknown, subcortical oscillator, independent of cortical oscillation, commonly recruits hand/arm muscles and may underlie functional recovery of dexterous finger movements

Hopf Bifurcation and the Existence and Stability of Closed Orbits in Three-Sector Models of Optimal Endogenous Growth

The present paper constructs a family of three-sector models of optimal endogenous growth, and conducts ex-act bifurcation analysis. In so doing, original six-dimensional equilibrium dynamics is decomposed into five-dimensional stationary autonomous dynamics and one-dimensional endogenously growing component. It isshown that the stationary dynamics thus decomposed undergoes supercritical Hopf bifurcation. It is inferredfrom the convex structure of our model that the dimension of a stable manifold of each closed orbit thus bifur-cated in this five-dimensional dynamics should be two

単音節の有効持続時間と感音難聴者の語音明瞭度との関係

Among the temporal elements in the autocorrelation function, the effective duration (τe) is a useful indicator of speech recognition for patients with sensorineural hearing impairment. We assessed the influence of speech recognition performance on the relationship between the percentage of accurately perceived articulation and the median τe (τe-med) and the relationship between monosyllabic confusion and the τe-med. Significant correlations were observed between the articulation percentage and the average τe-med in groups with high, middle, and low speech recognition scores (SRSs). Two-factor mixed analysis of variance revealed significant main effects for the condition (presentation/response). There was no significant main effect for group (high-, middle-, or low-SRS) scores and no significant interaction between the groups. The average τe-med of the response was significantly longer than that of the presentation in all three groups. Monosyllables with short τe-med values tended to be misheard as monosyllables with a long τe-med when confusion occurred. The τe-med was useful for estimating monosyllables that patients with sensorineural hearing impairment find easy to listen to, independent of speech recognition performance.権利情報：© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

Temporal dynamics of the sensorimotor convergence underlying voluntary limb movement

運動指令信号と感覚信号が統合されて運動が作り出される過程を発見 --中枢神経系と末梢神経系の大規模神経活動記録から明らかに--. 京都大学プレスリリース. 2022-11-24.Descending motor drive and somatosensory feedback play important roles in modulating muscle activity. Numerous studies have characterized the organization of neuronal connectivity in which descending motor pathways and somatosensory afferents converge on spinal motor neurons as a final common pathway. However, how inputs from these two pathways are integrated into spinal motor neurons to generate muscle activity during actual motor behavior is unknown. Here, we simultaneously recorded activity in the motor cortices (MCx), somatosensory afferent neurons, and forelimb muscles in monkeys performing reaching and grasping movements. We constructed a linear model to explain the instantaneous muscle activity using the activity of MCx (descending input) and peripheral afferents (afferent input). Decomposition of the reconstructed muscle activity into each subcomponent indicated that muscle activity before movement onset could first be explained by descending input from mainly the primary motor cortex and muscle activity after movement onset by both descending and afferent inputs. Descending input had a facilitative effect on all muscles, whereas afferent input had a facilitative or suppressive effect on each muscle. Such antagonistic effects of afferent input can be explained by reciprocal effects of the spinal reflex. These results suggest that descending input contributes to the initiation of limb movement, and this initial movement subsequently affects muscle activity via the spinal reflex in conjunction with the continuous descending input. Thus, spinal motor neurons are subjected to temporally organized modulation by direct activation through the descending pathway and the lagged action of the spinal reflex during voluntary limb movement

Primary Gastrointestinal T-Cell Lymphoma and Indolent Lymphoproliferative Disorders: Practical Diagnostic and Treatment Approaches

Simple Summary: It is challenging for pathologists to diagnose primary gastrointestinal T-cell neoplasms. Besides the rarity of the diseases, the small biopsy material makes it more difficult to differentiate between non-neoplastic inflammation and secondary involvement of extra gastrointestinal lymphoma. Since this group of diseases ranges from aggressive ones with a very poor prognosis to indolent ones that require caution to avoid overtreatment, the impact of the diagnosis on the patient is enormous. Although early treatment of aggressive lymphoma is essential, the treatment strategy is not well established, which is a problem for clinicians. This review provides a cross-sectional comparison of histological findings. Unlike previous reviews, we summarized up-to-date clinically relevant information including the treatment strategies as well as practical differential diagnosis based on thorough literature review. Abstract: Primary gastrointestinal (GI) T-cell neoplasms are extremely rare heterogeneous disease entities with distinct clinicopathologic features. Given the different prognoses of various disease subtypes, clinicians and pathologists must be aware of the key characteristics of these neoplasms, despite their rarity. The two most common aggressive primary GI T-cell lymphomas are enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. In addition, extranodal natural killer (NK)/T-cell lymphoma of the nasal type and anaplastic large cell lymphoma may also occur in the GI tract or involve it secondarily. In the revised 4th World Health Organization classification, indolent T-cell lymphoproliferative disorder of the GI tract has been incorporated as a provisional entity. In this review, we summarize up-to-date clinicopathological features of these disease entities, including the molecular characteristics of primary GI T-cell lymphomas and indolent lymphoproliferative disorders. We focus on the latest treatment approaches, which have not been summarized in existing reviews. Further, we provide a comprehensive review of available literature to address the following questions: How can pathologists discriminate subtypes with different clinical prognoses? How can primary GI neoplasms be distinguished from secondary involvement? How can these neoplasms be distinguished from non-specific inflammatory changes at an early stage

Primary Gastrointestinal T-Cell Lymphoma and Indolent Lymphoproliferative Disorders: Practical Diagnostic and Treatment Approaches

Simple Summary: It is challenging for pathologists to diagnose primary gastrointestinal T-cell neoplasms. Besides the rarity of the diseases, the small biopsy material makes it more difficult to differentiate between non-neoplastic inflammation and secondary involvement of extra gastrointestinal lymphoma. Since this group of diseases ranges from aggressive ones with a very poor prognosis to indolent ones that require caution to avoid overtreatment, the impact of the diagnosis on the patient is enormous. Although early treatment of aggressive lymphoma is essential, the treatment strategy is not well established, which is a problem for clinicians. This review provides a cross-sectional comparison of histological findings. Unlike previous reviews, we summarized up-to-date clinically relevant information including the treatment strategies as well as practical differential diagnosis based on thorough literature review. Abstract: Primary gastrointestinal (GI) T-cell neoplasms are extremely rare heterogeneous disease entities with distinct clinicopathologic features. Given the different prognoses of various disease subtypes, clinicians and pathologists must be aware of the key characteristics of these neoplasms, despite their rarity. The two most common aggressive primary GI T-cell lymphomas are enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. In addition, extranodal natural killer (NK)/T-cell lymphoma of the nasal type and anaplastic large cell lymphoma may also occur in the GI tract or involve it secondarily. In the revised 4th World Health Organization classification, indolent T-cell lymphoproliferative disorder of the GI tract has been incorporated as a provisional entity. In this review, we summarize up-to-date clinicopathological features of these disease entities, including the molecular characteristics of primary GI T-cell lymphomas and indolent lymphoproliferative disorders. We focus on the latest treatment approaches, which have not been summarized in existing reviews. Further, we provide a comprehensive review of available literature to address the following questions: How can pathologists discriminate subtypes with different clinical prognoses? How can primary GI neoplasms be distinguished from secondary involvement? How can these neoplasms be distinguished from non-specific inflammatory changes at an early stage

Historical and pathological overview of Castleman disease

Castleman disease consists of several lymphoproliferative subtypes that share some histological features in the lymph nodes. On the other hand, numerous clinical findings and etiologies make the disease challenging to understand. The origin of the disease is the hyaline vascular-type unicentric Castleman disease (UCD), first reported by Benjamin Castleman et al. in 1954. Although UCD is characterized by localized lesions and lack of symptoms, multicentric Castleman disease (MCD) with multiple lesions and systemic symptoms was reported by Frizzera in 1983. MCD is further divided according to KSHV/HHV8 infection status. In KSHV/HHV8-related MCD, viral infection signals lead to excessive cytokine production, and cause clinical and pathologic abnormalities. Some cases of plasma cell-type KSHV/HHV8-negative MCD can be found in association with POEMS syndrome (polyneuropathy, organomegaly, cndocrinopathy, M-protcins, and skin changes), which is a paraneoplastic syndrome. The others are idiopathic MCD, which are currently considered a heterogeneous group of diseases with overlapping pathological and clinical features. In this article, we summarize the historical evolution of Castleman disease to help understand the disease concept. We also review the latest ideas and definitions of the subtypes within the MCD spectrum and summarize the histopathological findings

Invariance Violation Extends the Cosmic Ray Horizon ?

We postulate in the present paper that the energy-momentum relation is modified for very high energy particles to violate Lorentz invariance and the speed of photon is changed from the light velocity c. The violation effect is amplified, in a sensitive way to detection, through the modified kinematical constraints on the conservation of energy and momentum, in the absorption process of gamma-rays colliding against photons of longer wavelengths and converting into an electron-positron pair. For gamma-rays of energies higher than 10 TeV, the minimum energy of the soft photons for the reaction and then the absorption mean free path of gamma-rays are altered by orders of magnitude from the ones conventionally estimated. Consideration is similarly applied to high energy cosmic ray protons. The consequences may require the standard assumptions on the maximum distance that very high energy radiation can travel from to be revised.Comment: 14 pages, 1 figure, to be published in Ap J Letter

Mathematics & Science Education and Income: An Empirical Study in Japan

Abstract: Since the second half of the 1990s, the decline in academic standards in mathematics and science among undergraduate students in Japan has been noted. Despite this, problems in science education have become increasingly severe, and their impact is having a mounting effect on Japan's economy. This paper studies the return to a university education in Japan by taking into account the relative ranking of the universities. We present an empirical analysis of how annual income differs depending on whether a major is natural science or humanities. We have found that science graduates have a higher average income than humanities graduates indicates that the added value they are producing is higher than that of humanities graduates. Of particular interest is the fact that a comparison of humanities graduates of A rank universities who did not sit admission examinations in mathematics with science graduates of B rank university showed that it was the science graduates who recorded higher average income at every age grade. The above comparison also reveals that even those humanities graduates of A rank universities who did sit admission examinations in mathematics are out-earned by science graduates of B rank universities in the under 30 and 55 and over age groups

When to Replan? An Adaptive Replanning Strategy for Autonomous Navigation using Deep Reinforcement Learning

The hierarchy of global and local planners is one of the most commonly utilized system designs in autonomous robot navigation. While the global planner generates a reference path from the current to goal locations based on the pre-built static map, the local planner produces a kinodynamic trajectory to follow the reference path while avoiding perceived obstacles. To account for unforeseen or dynamic obstacles not present on the pre-built map, ``when to replan'' the reference path is critical for the success of safe and efficient navigation. However, determining the ideal timing to execute replanning in such partially unknown environments still remains an open question. In this work, we first conduct an extensive simulation experiment to compare several common replanning strategies and confirm that effective strategies are highly dependent on the environment as well as the global and local planners. Based on this insight, we derive a new adaptive replanning strategy based on deep reinforcement learning, which can learn from experience to decide appropriate replanning timings in the given environment and planning setups. Our experimental results demonstrate that the proposed replanner can perform on par or even better than the current best-performing strategies in multiple situations regarding navigation robustness and efficiency.Comment: 7 pages, 3 figure