ASCA Observations of the Central Regions of M31

Using ASCA, spatially integrated X-ray spectra of the central regions of M31 were studied. Data were accumulated over three different circular regions, with the radii of 3', 6' and 12', all centered on the nucleus. The spectra are relatively similar among the three regions. In the energy range above 1.5 keV, the spectra are reproduced by a combination of a disk black-body component and a black-body component, implying that the emission mainly comes from an assembly of low-mass X-ray binaries. In energies below 1.5 keV, the spectra involves two additional softer components, expressed with thin-thermal plasma emission models of temperatures ~ 0.9 keV and ~ 0.3 keV. Over the central 12' (2.4 kpc) region and in the 0.5-10 keV energy band, the binary component has a luminosity of 2.6 x 10^{39} erg/s, while the two softer components both exhibit luminosities of ~ 2 x 10^{38} erg/s. These results are compared with those from other missions, including Chandra and XMM-Newton in particular. Discussion is made on the nature of the two softer spectral components besides the binary one.Comment: 12 pages, 8 figures and 5 tables; uses pasj00.cls; accepted for Publications of the Astronomical Society of Japa

Weakly bound molecules as sensors of new gravitylike forces

Several extensions to the Standard Model of particle physics, including light dark matter candidates and unification theories predict deviations from Newton’s law of gravitation. For macroscopic distances, the inverse-square law of gravitation is well confirmed by astrophysical observations and laboratory experiments. At micrometer and shorter length scales, however, even the state-of-the-art constraints on deviations from gravitational interaction, whether provided by neutron scattering or precise measurements of forces between macroscopic bodies, are currently many orders of magnitude larger than gravity itself. Here we show that precision spectroscopy of weakly bound molecules can be used to constrain non-Newtonian interactions between atoms. A proof-of-principle demonstration using recent data from photoassociation spectroscopy of weakly bound Yb2 molecules yields constraints on these new interactions that are already close to state-of-the-art neutron scattering experiments. At the same time, with the development of the recently proposed optical molecular clocks, the neutron scattering constraints could be surpassed by at least two orders of magnitude

Case Report: Event-Related Desynchronization Observed During Volitional Swallow by Electroencephalography Recordings in ALS Patients With Dysphagia

Dysphagia is a severe disability affecting daily life in patients with amyotrophic lateral sclerosis (ALS). It is caused by degeneration of both the bulbar motor neurons and cortical motoneurons projecting to the oropharyngeal areas. A previous report showed decreased event-related desynchronization (ERD) in the medial sensorimotor areas in ALS dysphagic patients. In the process of degeneration, brain reorganization may also be induced in other areas than the sensorimotor cortices. Furthermore, ALS patients with dysphagia often show a longer duration of swallowing. However, there have been no reports on brain activity in other cortical areas and the time course of brain activity during prolonged swallowing in these patients. In this case report, we investigated the distribution and the time course of ERD and corticomuscular coherence (CMC) in the beta (15-25 Hz) frequency band during volitional swallow using electroencephalography (EEG) in two patients with ALS. Case 1 (a 71-year-old man) was diagnosed 2 years before the evaluation. His first symptom was muscle weakness in the right hand; 5 months later, dysphagia developed and exacerbated. Since his dietary intake decreased, he was given an implantable venous access port. Case 2 (a 64-year-old woman) was diagnosed 1 year before the evaluation. Her first symptom was open-nasal voice and dysarthria; 3 months later, dysphagia developed and exacerbated. She was given a percutaneous endoscopic gastrostomy. EEG recordings were performed during volitional swallowing, and the ERD was calculated. The average swallow durations were 7.6 ± 3.0 s in Case 1 and 8.3 ± 2.9 s in Case 2. The significant ERD was localized in the prefrontal and premotor areas and lasted from a few seconds after the initiation of swallowing to the end in Case 1. The ERD was localized in the lateral sensorimotor areas only at the initiation of swallowing in Case 2. CMC was not observed in either case. These results suggest that compensatory processes for cortical motor outputs might depend on individual patients and that a new therapeutic approach using ERD should be developed according to the individuality of ALS patients with dysphagia

Effect of maximum grip strength on controlled force exertion measured by a computer-generated sinusoidal waveform in young adult males

Context: It is important to develop a method to accurately measure controlled force exertion (CFE). Objectives: This study aimed to examine the effect of maximum grip strength on CFE measured by a sinusoidal waveform in 81 right-handed young males aged 15-29 years. Methods: On the basis of grip strength measurements, participants were divided into the following three groups: low (males 20; mean age 19.5 years; standard deviation (SD) = 5.0 years), medium (males 41; mean age 22.8 years; SD = 4.2 years), and high (males 20; mean age 23.7 years; SD = 3.4 years). Participants adjusted the submaximal grip strength of the dominant hand with changes in the demand values that were displayed as a sinusoidal waveform with a frequency of 0.1 Hz on a computer screen. The abovementioned test was performed three times with a 1-min interval after one practice trial. Each trial lasted 40 s. The sum of the differences between the demand value and grip exertion strength value for 25 s was considered as the evaluation parameter. Results: Controlled force exertion values demonstrated insignificant correlations with age and maximum grip strength in all groups (r = 0.07; r = -0.12; p > 0.05). No significant differences were found between CFE mean scores that was adjusted for age and varying maximum grip strength in the three groups (F = 1.95; p > 0.05). Conclusions: Based on the sinusoidal waveform display, we inferred that maximum grip strength has little effect on CFE evaluation in young males. © 2014 Springer-Verlag Italia

Event-Related Desynchronization and Corticomuscular Coherence Observed During Volitional Swallow by Electroencephalography Recordings in Humans

Swallowing in humans involves many cortical areas although it is partly mediated by a series of brainstem reflexes. Cortical motor commands are sent to muscles during swallow. Previous works using magnetoencephalography showed event-related desynchronization (ERD) during swallow and corticomuscular coherence (CMC) during tongue movements in the bilateral sensorimotor and motor-related areas. However, there have been few analogous works that use electroencephalography (EEG). We investigated the ERD and CMC in the bilateral sensorimotor, premotor, and inferior prefrontal areas during volitional swallow by EEG recordings in 18 healthy human subjects. As a result, we found a significant ERD in the beta frequency band and CMC in the theta, alpha, and beta frequency bands during swallow in those cortical areas. These results suggest that EEG can detect the desynchronized activity and oscillatory interaction between the cortex and pharyngeal muscles in the bilateral sensorimotor, premotor, and inferior prefrontal areas during volitional swallow in humans

Probing Non-Newtonian gravity by photoassociation spectroscopy

State of the art photoassociative measurements of bound state energies in the ground state Yb[2] molecule are used to establish limits on non-Newtonian gravity at Yukawa ranges of nanometers

Ultra-high-molecular-weight Polyethylene (UHMWPE) Wing Method for Strong Cranioplasty

We developed a new cranioplasty method that utilizes artificial bone made of ultra-high-molecular-weight polyethylene, with a wedge-shaped edge (UHMWPE Wing). This study shows the methods and data of case series and finite element analyses with the UHMWPE Wing. A circumferential wing was preoperatively designed for a custom-made artificial bone made of UHMWPE to achieve high fixed power and to minimize the usage of cranial implants. Here, we present 4 years of follow-up data and finite element analyses for patients treated with the UHMWPE Wing between February 2015 and February 2019. Eighteen consecutive patients underwent cranioplasty using our UHMWPE Wing design. There were no postoperative adverse events in 17 of the patients for at least 18 months. One case of hydrocephalus experienced screw loosening and graft uplift due to shunt malfunction. Placement of a ventriculo-peritoneal shunt immediately returned the artificial bone to normal position. Finite element analyses revealed that a model using the UHMWPE Wing had the highest withstand load and lowest deformation. This is the first report on the UHMWPE Wing method. This method may enable clinicians to minimize dead space and achieve high strength in cranioplasty

Detection of deviance in Japanese kanji compound words

Reading fluency is based on the automatic visual recognition of words. As a manifestation of the automatic processing of words, an automatic deviance detection of visual word stimuli can be observed in the early stages of visual recognition. To clarify whether this phenomenon occurs with Japanese kanji compounds-since their lexicality is related to semantic association-we investigated the brain response by utilizing three types of deviants: differences in font type, lexically correct or incorrect Japanese kanji compound words and pseudo-kanji characters modified from correct and incorrect compounds. We employed magnetoencephalography (MEG) to evaluate the spatiotemporal profiles of the related brain regions. The study included 22 adult native Japanese speakers (16 females). The abovementioned three kinds of stimuli containing 20% deviants were presented during the MEG measurement. Activity in the occipital pole region of the brain was observed upon the detection of font-type deviance within 250 ms of stimulus onset. Although no significant activity upon detecting lexically correct/incorrect kanji compounds or pseudo-kanji character deviations was observed, the activity in the posterior transverse region of the collateral sulcus (pCoS)-which is a fusiform neighboring area-was larger when detecting lexically correct kanji compounds than when detecting pseudo-kanji characters. Taken together, these results support the notion that the automatic detection of deviance in kanji compounds may be limited to a low-level feature, such as the stimulus stroke thickness.Peer reviewe

“Transmantle sign”を示す限局性皮質異形成における神経細胞の成熟と分化の未熟性：層特異的マーカー発現による解析

Transmantle dysplasia is a rare type of focal cortical dysplasia (FCD) characterized by expansion of the cortex from the deep white matter to the surface and in which there is a FCD IIA or IIB pathologic pattern. To characterize possible mechanisms underlying this regional disorder of radial migrating cells, we studied the expression patterns of neocortical layer-specific markers using immunohistochemistry in surgical specimens from 5 FCD IIA and 4 FCD IIB cases in children. All neuronal cells expressed the mature neuron marker MAP2/2B but not the microglia markers Iba-1 and CD68. Some layer-specific markers showed distinct expression patterns. TBR1-positive, SATB2-positive, and FOXP1-positive cells were diffusely distributed in the cortex and/or the white matter. TBR1-positive and FOXP1-positive cells were generally more numerous in FCD IIB than in FCD IIA and were mostly in the cortical molecular and upper layers. FOXP1-, FOXP2-, and CUTL1-positive cells also expressed the immature neuron marker, Nestin/PROX1, whereas TBR1-, CTIP2-, and SATB2-positive cells only expressed MAP2/2B. These data highlight differences between FCD IIB and FCD IIA with more cells having the immature marker in upper layer markers in the former. By analyzing layer-specific marker expression patterns, we identified apparent neuronal maturation differences between FCD IIA and FCD IIB in cases of transmantle dysplasia.博士（医学）・乙第1312号・平成25年5月29

Deep simultaneous limits on optical emission from FRB 20190520B by 24.4 fps observations with Tomo-e Gozen

We conduct 24.4~fps optical observations of repeating Fast Radio Burst (FRB) 20190520B using Tomo-e Gozen, a high-speed CMOS camera mounted on the Kiso 105-cm Schmidt telescope, simultaneously with radio observations carried out using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). We succeeded in the simultaneous optical observations of 11 radio bursts that FAST detected. However, no corresponding optical emission was found. The optical fluence limits as deep as 0.068 Jy ms are obtained for the individual bursts (0.029 Jy ms on the stacked data) corrected for the dust extinction in the Milky Way. The fluence limit is deeper than those obtained in the previous simultaneous observations for an optical emission with a duration $\gtrsim 0.1$ ms. Although the current limits on radio--optical spectral energy distribution (SED) of FRBs are not constraining, we show that SED models based on observed SEDs of radio variable objects such as optically detected pulsars, and a part of parameter spaces of theoretical models in which FRB optical emission is produced by inverse-Compton scattering in a pulsar magnetosphere or a strike of a magnetar blastwave into a hot wind bubble, can be ruled out once a similar fluence limit as in our observation is obtained for a bright FRB with a radio fluence $\gtrsim 5$ Jy ms.Comment: Accepted for publication in ApJ, metadata correcte