Pattern classification by stochastic neural network with missing data

In this paper, pattern classification by stochastic neural networks is considered. This model is also called a Gaussian mixture model. When missing data exist in the training data, it is usual to remove incomplete instants. Here we take another approach, where the missing elements are estimated by using the conditional expectation based on the estimated model by using the EM algorithm. It is shown by using Fisher's Iris data that this approach is superior to removing incomplete data</p

Magneto-optical Measurements using a Hybrid Magnet(Part II. Several Instruments and Techniques Developed in HFLSM)

Magneto-absorption spectra were obtained in the fields up to 23 T by means of a hybrid magnet at Tohoku University. The absorption was obtained by measuring the intensity of transmitted light through the sample. Optical fiber systems were utilized for the light transmission, which enabled rapid assembly of the light pass within a restricted machine time. The spectra were taken in the wavelength region of about 300 to 2000 nm. The monochromator was fully remote controlled from outside of the magnet room by a computer

Electroluminescence of europium silicate thin film on silicon

We report an electroluminescent device fabricated by a europium silicate layer on a siliconsubstrate. The device exhibits uniform-intense white color electroluminescence with an externalquantum efficiency about 0.1% at room temperature, a low operating threshold voltage (about 6 V)and a fast response to the modulation signal at the frequency of 1 MHz

Behavior of chum salmon as revealed by micro data loggers off the Sanriku coast, Japan: A review

The homing season of chum salmon in the Sanriku coastal area is generally late September to January. The surface water temperature is 20℃ at the beginning of the season and decreases to 12℃ at the end. This temperature condition is very tough for the homing migration of chum salmon, since they are typical cold-water species. How do they behave in the waters where temperatures can be close to their upper lethal limit? We monitored swimming behavior of salmon using micro data-loggers to study the relationship between homing behavior and ambient temperature. Seasonal changes in seawater temperature transformed the salmon behavior from deep diving to surface swimming. The deep diving is a type of behavioral thermoregulation in thermally stratified water with high surface temperature, whereas surface swimming helps the salmon to locate their natal rivers. Sexual maturation induced the salmon to seek their natal river in the surface water, even if their temperature was high. An analysis of the vertical movements of the salmon indicated that salmon are negatively buoyant throughout the dive, and thus, the energy cost for deep diving cannot be negligible. Our data indicate the high behavioral adaptability of salmon to such thermally stratified water with high surface temperature

非破壊的で迅速に骨形成を評価できるマーカーとしての培養液中カルシウム濃度について

Artificial bones made of β-tricalcium phosphate (β-TCP) combined with bone marrow-derived mesenchymal stromal cells (BM-MSCs) are used for effective reconstruction of bone defects caused by genetic defects, traumatic injury, or surgical resection of bone tumors. However, the selection of constructs with high osteogenic potential before implantation is challenging. The purpose of this study was to determine whether the calcium concentration in BM-MSC culture medium can be used as a nondestructive and simple osteogenic marker for selecting tissue-engineered grafts constructed using β-TCP and BM-MSCs. We prepared three cell passages of BM-MSCs derived from three 7-week-old, male Fischer 344 rats; the cells were cultured in osteoinductive medium in the presence of β-TCP for 15 days. The medium was replaced with fresh medium on day 1 in culture and subsequently changed every 48 h; it was collected for measurement of osteocalcin secretion and calcium concentration by enzyme-linked immunosorbent assay and X-ray fluorescence spectrometry, respectively. After cultivation, the constructs were implanted subcutaneously into the backs of recipient rats. Four weeks after implantation, the alkaline phosphatase (ALP) activity and osteocalcin content of the constructs were measured. A strong inverse correlation was observed between the calcium concentration in the medium and the ALP activity and osteocalcin content of the constructs, with Pearson's correlation coefficients of 0.92 and 0.90, respectively. These results indicate that tissue-engineered bone with high osteogenic ability can be selected before implantation based on low calcium content of the culture medium, resulting in successful bone formation after implantation. This nondestructive, simple method shows great promise for assessing the osteogenic ability of tissue-engineered bone.博士（医学）・乙第1411号・平成29年11月24日Copyright © 2017 Cognizant, LLC. The articles contained in the following journals published by Cognizant, LLC are "open access articles" subject to the terms of the Creative Commons Attribution Non-Commercial (CC BY NC) license(https://creativecommons.org/licenses/by-nc/3.0/). That license permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. The articles are therefore free to read, download, cite and share with others

肘の内外反変形に伴う尺骨神経の伸長度変化に関する生体力学的研究

Background: Cubital tunnel syndrome can be caused by overtraction and dynamic compression in elbow deformities. The extent to which elbow deformities contribute to ulnar nerve strain is unknown. Here, we investigated ulnar nerve strain caused by cubitus valgus/varus deformity using fresh-frozen cadavers. Methods: We used six fresh-frozen cadaver upper extremities. A strain gauge was placed on the ulnar nerve 2 cm proximal to the medial epicondyle of the humerus. For the elbow deformity model, osteotomy was performed at the distal humerus, and plate fixation was performed to create cubitus valgus/varus deformities (10°, 20°, and 30°). Ulnar nerve strain caused by elbow flexion (0–125°) was measured in both the normal and deformity models. The strains at different elbow flexion angles within each model were compared, and the strains at elbow extension and at maximum elbow flexion were compared between the normal model and each elbow deformity model. However, in the cubitus varus model, the ulnar nerve deflected more than the measurable range of the strain gauge; elbow flexion of 60° or more were considered effective values. Statistical analysis of the strain values was performed with Friedman test, followed by the Williams’ test (the Shirley‒Williams’ test for non-parametric analysis). Results: In all models, ulnar nerve strain increased significantly from elbow extension to maximal flexion (control: 13.2%; cubitus valgus 10°: 13.6%; cubitus valgus 20°: 13.5%; cubitus valgus 30°: 12.2%; cubitus varus 10°: 8.3%; cubitus varus 20°: 8.2%; cubitus varus 30°: 6.3%, P < 0.001). The control and cubitus valgus models had similar values, but the cubitus varus models revealed that this deformity caused ulnar nerve relaxation. Conclusions: Ulnar nerve strain significantly increased during elbow flexion. No significant increase in strain 2 cm proximal to the medial epicondyle was observed in the cubitus valgus model. Major changes may have been observed in the measurement behind the medial epicondyle. In the cubitus varus model, the ulnar nerve was relaxed during elbow extension, but this effect was reduced by elbow flexion.博士（医学）・甲第865号・令和5年3月15

A simple role of coral-algal symbiosis in coral calcification based on multiple geochemical tracers

Light-enhanced calcification of reef-building corals, which eventually create vast coral reefs, is well known and based on coral-algal symbiosis. Several controversial hypotheses have been proposed as possible mechanisms for connecting symbiont photosynthesis and coral calcification, including pH rise in the internal pool, role of organic matrix secretion, and enzyme activities. Here, based on the skeletal chemical and isotopic compositions of symbiotic and asymbiotic primary polyps of Acropora digitifera corals, we show a simple pH increase in the calcification medium as the predominant contribution of symbionts to calcification of host corals. We used the symbiotic and asymbiotic primary polyps reared for 10 days at four temperatures (27, 29, 31, and 33 °C), five salinities (34, 32, 30, 28, and 26), and four pCO2 levels (<300, 400, 800, and 1000 µatm). As a result of analyzing multiple geochemical tracers (U/Ca, Mg/Ca, Sr/Ca, δ18O, δ13C, and δ44Ca), a clear and systematic decrease in skeletal U/Ca ratio (used as a proxy for calcification fluid pH) was observed, indicating a higher pH of the fluid in symbiotic compared to asymbiotic polyps. In contrast, Mg/Ca ratios (used as a tentative proxy for organic matrix secretion) and δ44Ca (used as an indicator of Ca2+ pathway to the fluid) did not differ between symbiotic and asymbiotic polyps. This suggests that organic matrix secretion related to coral calcification is controlled mainly by the coral host itself, and a transmembrane transport of Ca2+ does not vary according to symbiosis relationship. Skeletal δ18O values of both symbiotic and asymbiotic polyps showed offsets between them with identical temperature dependence. Based on a newly proposed model, behavior of δ18O in the present study seems to reflect the rate of CO2 hydration in the calcifying fluid. Since CO2 hydration is promoted by enzyme carbonic anhydrase, the offset of δ18O values between symbiotic and asymbiotic polyps is attributed to the differences of enzyme activity, although the enzyme is functional even in the asymbiotic polyp. Symbiotic δ13C values in the temperature and salinity experiments were higher compared to those in the asymbiotic polyps due to photosynthesis, although photosynthetic δ13C signals in the pCO2 experiment were masked by the dominant δ13C gradient in dissolved inorganic carbon in seawater caused by 13C-depletd CO2 gas addition in the higher pCO2 treatments. Sr/Ca ratios showed a negligible relationship according to variation of temperature, salinity, and pCO2, although it might be attributed to relatively large deviations of replicates of Sr/Ca ratios in the present study. Overall, only the U/Ca ratio showed a significant difference between symbiotic and asymbiotic polyps throughout all experiments, indicating that the critical effect on coral calcification caused by symbiotic algae is the increase of pH of the calcifying fluid by photosynthesis