Formation of intermediate-mass black holes in circumnuclear regions of galaxies

Recent high-resolution X-ray imaging studies have discovered possible candidates of intermediate-mass black holes with masses of M_\bullet \sim 10^{2-4} \MO in circumnuclear regions of many (disk) galaxies. It is known that a large number of massive stars are formed in a circumnuclear giant H {\sc ii} region. Therefore, we propose that continual merger of compact remnants left from these massive stars is responsible for the formation of such an intermediate-mass black hole within a timescale of $\sim 10^9$ years. A necessary condition is that several hundreds of massive stars are formed in a compact region with a radius of a few pc.Comment: 11 pages, PASJ in pres

CDiP technology for reverse engineering of sporadic Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disease that causes cognitive impairment for which neither treatable nor preventable approaches have been confirmed. Although genetic factors are considered to contribute to sporadic AD, for the majority of AD patients, the exact causes of AD aren’t fully understood. For AD genetics, we developed cellular dissection of polygenicity (CDiP) technology to identify the smallest unit of AD, i.e., genetic factors at a cellular level. By CDiP, we found potential therapeutic targets, a rare variant for disease stratification, and polygenes to predict real-world AD by using the real-world data of AD cohort studies (Alzheimer’s Disease Neuroimaging Initiative: ADNI and Japanese Alzheimer’s Disease Neuroimaging Initiative: J-ADNI). In this review, we describe the components and results of CDiP in AD, induced pluripotent stem cell (iPSC) cohort, a cell genome-wide association study (cell GWAS), and machine learning. And finally, we discuss the future perspectives of CDiP technology for reverse engineering of sporadic AD toward AD eradication

A Patient with Fragile X-Associated Tremor/Ataxia Syndrome Presenting with Executive Cognitive Deficits and Cerebral White Matter Lesions

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that primarily affects males who are carriers of a premutation of a CGG expansion in the FMR1 gene. In Asian populations, FXTAS has rarely been reported. Here, we report the case of a Japanese FXTAS patient who showed predominant executive cognitive deficits as the main feature of his disease. In contrast, the patient exhibited only very mild symptoms of intention tremor and ataxia, which did not interfere with daily activities. A gene analysis revealed that the patient carried a premutation of a CGG expansion (111 CGG repeats) in the FMR1 gene. The mRNA expression level of FMR1 in the patient was 1.5-fold higher than in controls. On brain MRI scans, fluid-attenuated inversion recovery images showed high-intensity lesions in the middle cerebellar peduncles and the cerebral white matter, with a frontal predominance. The present case extends previous notions regarding the cognitive impairment in FXTAS patients. Recognizing FXTAS patients with predominant cognitive impairment from various ethnic backgrounds would contribute to our understanding of the phenotypic variation of this disease

de Vaucouleurs-Ikeuchi Diagram and Commutation Relations among Phase Space Coordinates

We consider the relations between de Vaucouleurs-Ikeuchi diagram and generalized commutation relations among the coordinates and momenta. All physical objects in the Universe ranging from elementary particles to super cluster of galaxies are confined within the Triangle of the de Vaucouleurs-Ikeuchi diagram on the matter density versus scale length plane. These three boundaries are characterized by the quantum uncertainty principle, gravitational event horizon, and cosmological constant. These are specified by the non-zero commutation relations $[x_\mu,p_\nu], [x_\mu, x_\nu]$ (strictly $[x_i,t]$) and $[p_\mu,p_\nu]$, respectively. The canonical commutation relation $[x_i,p_j]$ are slightly modified, which preserves the self consistency as a whole.Comment: 10 pages, 2 figures, the enlarged version to which one auhtor was adde

Hubble Parameter in Void Universe

We investigate the distance-redshift relation in the simple void model. As discussed by Moffat and Tatarski, if the observer stays at the center of the void, the observed Hubble parameter is not so different from the background Hubble parameter. However, if the position of observer is off center of the void, we must consider the peculiar velocity correction which is measured by the observed dipole anisotropy of cosmic microwave background. This peculiar velocity correction for the redshift is crucial to determine the Hubble parameter and we shall discuss this effect. Further the results of Turner et al by the N-body simulation will be also considered.Comment: 5 pages, uuencode compressed latex with 2 EPS figures

Familial and sporadic chronic progressive degenerative parietal ataxia

Background & objective: Parietal ataxia has been mainly reported as a consequence of acute ischemic stroke, while degenerative parietal ataxia has not been reported. Methods: We investigated clinical characteristics, neuroimaging data, and genetic analysis of patients with cerebellar ataxia plus parietal atrophy. Results: We identified seven patients, including five patients from two families, with chronic progressive cerebellar ataxia due to degenerative parietal atrophy but not stroke. Age at onset of ataxia was 57.6 +/- 6.9 years. All patients showed chronic progressive cerebellar ataxia with severity of ataxic gait > limb ataxia > dysarthria. Patients showed no cognitive dysfunction, muscle weakness, or parkinsonism, and only two patients showed mild sensory disturbances. The seven patients showed lateralized limb ataxia with greater contralateral parietal lobe atrophy by magnetic resonance imaging, and hypoperfusion by single photon emission computed tomography, without any abnormal cerebellar pathology (i.e., crossed cerebellar diaschisis). Pathogenic mutations in the microtubule-associated protein tau gene were not found using two single nucleotide polymorphisms. Conclusions: This is the first description showing unique clinical features of familial and sporadic chronic progressive degenerative parietal ataxia