Yamato University

記者として働きながら博士課程を修了した著者が，中国とインドの水資源をめぐる紛争とその防止策を分析した著書『アジアの水覇権』で学会賞を受賞．独自資料などを基に「水覇権」の構造を描き，社会的背景に根ざす水問題の本質を明らかにした．

本研究では，豚ロース部分肉の保存過程における多周波数インピーダンス法の有効性を検証し，インピーダンス値比と保存日数，mK値（修正K値；mK＝（HxR+Hx）/（IMP+HxR+Hx）と定義されるATP分解度指標）およびうま味成分（グルタミン酸含量）との関連性を明らかにした。豚肉は適切な環境での保存により品質が向上するが，多くの小売店では保存による美味しさの変化を考慮せず，商品回転を重視した販売が行われている現状がある。本研究では，豚ロース部分肉に多周波数インピーダンス測定法を適用し，高低2種類の周波数（100 kHzおよび2 kHz）を用いたインピーダンス値比と各種指標の関係を調査した。インピーダンス値比（2 kHz/100 kHz）はmK値との間に強い負の相関（r＝－0.87）が，うま味成分であるグルタミン酸含量との間にも強い負の相関（r＝－0.82）が認められた。加えて，インピーダンス値比と保存日数との間にも強い負の相関（r＝－0.89）が示された。これらの結果から，保存過程では保存日数の経過に伴いインピーダンス値比が低下するとともに，mK値とグルタミン酸含量が上昇するという一貫したパターンが得られた。特に，インピーダンス値比とグルタミン酸含量の高い相関は，本手法が単なる保存期間の推定だけでなく，保存に伴ううま味成分の増加という品質面の評価にも有効であることを示している。多周波数インピーダンス法は，豚肉の保存状態を総合的かつ非破壊的に評価できる技術として，従来の経験や勘に依存していた主観的な評価方法や，時間と費用のかかる化学分析に代わり，小売店や流通現場において客観的かつ数値的な品質評価を可能にするツールとなり得ることが示された。

Health risks associated with vascular disorders, such as cold sensitivity caused by peripheral cooling, tend to become more severe during winter. To mitigate these effects, continuous monitoring of a peripheral cooling and timely, targeted thermal interventions are essential. Previous studies have proposed a wearable system that assesses individual cold sensitivity by measuring the temperature gradient between the core body temperature and peripheral skin temperatures, such as those of the hands and feet. However, because thermal comfort varies significantly between individuals, a preventive approach that is tailored to personal cold sensitivity is essential. This study uses two internationally recognized thermal comfort indices: the Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD). The results reveal that limiting the temperature difference between the core body temperature and the surface of the toes to within 6.60 ℃ (±1.76) and limiting the difference between the core and the wrist to within 5.06 ℃ (±2.04) is effective in maintaining a PMV within ± 0.5 and a PPD below 10 %. The contribution of this study lies in demonstrating that thermal interventions targeting locally cooled body areas, based on the obtained findings, can help maintain thermal comfort while preventing cold sensitivity.

Improper treatment of antibiotics in wastewater has led to the spread of antimicrobial resistance. One of the solutions to this global problem is the Bio-Fenton reaction, which is effective in removing antibiotics. To stimulate Bio-Fenton reaction, magnetite fine particles are employed in the advanced activated sludge process. While combining the activated sludge process with membrane filtration can be more efficient, membrane bioreactors (MBRs) require frequent cleaning to prevent membrane fouling, inducing chemical and energy costs. To address this issue, a magnetic filter to capture activated sludge flocs with the magnetic particles was equipped near the MF (microfiltration) membrane surface to mitigate membrane fouling. The objective of this study is to assess the effectiveness of the magnetic filter in a lab-scale advanced Bio-Fenton MBR system. Transmembrane pressure (TMP) was measured as an indicator of the fouling extent, and the effect of the magnetic filter was evaluated by examining TMP change, supported by SEM (Scanning electron microscopy) analysis of foulant composition. Results showed lower TMPs and less Fe composition in the foulants with magnetic filter across various conditions. From the results, we concluded that the magnetic filter was effective for alleviating membrane fouling in the advanced Bio-Fenton MBR system.

Abstract This study focused on the social roles of community-dwelling older adults during the COVID-19 pandemic in Japan and aimed to clarify their actual conditions and related factors. We compared the two groups of the values of four social roles of the Tokyo Metropolitan Institute of Gerontology Index of Competence and various survey items in 127 elderly subjects aged 65 years or older. The group who talked to young people tended to eat alone more (p = 0.00), to be more depressed (p = 0.00), and had lower food intake diversity scores (p = 0.04) than the group who didn’t talk to young people. No significant associations were found between the three other social roles and the values of the various survey items. The results of the Logistic regression analysis showed that the no-involvement group was significantly associated with eating alone (OR=4.28, 95%CI=1.69-10.83, p=0.00) and depression-prone individuals (OR=3.73, 95%CI=1.02-6.96, p=0.01). Tanaka et al. (2016) reported that even at the level of intergenerational interaction of “talking to younger people” in daily life, the “with opportunity” group had a 1.2 to 1.5 times lower risk of future anxiety than the “without opportunity” group. In the present study, the results support the previous studies, although the interaction was at the level of “talking to younger people. It suggested that ensuring opportunities for intergenerational exchange is important to maintain the physical and mental health of the elderly during the pandemic.

Background We aimed to investigate the association between protein intake and quadriceps quantity and quality on the paretic and non-paretic sides during rehabilitation in people with subacute stroke. Method Eighty-six people with stroke were recruited from a rehabilitation ward. We measured quadriceps muscle quantity and quality on the paretic and non-paretic sides using ultrasonography at admission and after 4weeks. Protein intake was assessed 2 or 3weeks after admission, and participants were classified into two groups: adequate and inadequate protein intake groups. Analysis of covariance was used to determine the effects of protein intake on quadriceps muscle quantity and quality. Results The mean age (standard deviation), median interval between stroke onset and admission (interquartile range) and male proportion of the study participants were 67.6 (13.5) years, 22.5 (16.8-31.3) days, and 54.7%, respectively. The adequate protein intake group showed significantly greater improvements in paretic-side quadriceps thickness than the inadequate group (group-by-time interaction, F =8.771, P =0.004). In contrast, no significant interactions were observed in quadriceps thickness on the non-paretic side (F =2.383, P =0.127) and quadriceps echo intensity on both sides (paretic-side: F =0.020, P =0.887, non-paretic side: F =0.181, P =0.672). Conclusions Adequate protein intake may be useful for improving quadriceps quantity on the paretic side in people with subacute stroke undergoing rehabilitation. However, quadriceps quantity on the non-paretic side and quadriceps quality on both sides were not significantly associated with adequate protein intake.

IntroductionChaotic resonance is similar to stochastic resonance, which emerges from chaos as an internal dynamical fluctuation. In chaotic resonance, chaos-chaos intermittency (CCI), in which the chaotic orbits shift between the separated attractor regions, synchronizes with a weak input signal. Chaotic resonance exhibits higher sensitivity than stochastic resonance. However, engineering applications are difficult because adjusting the internal system parameters, especially of biological systems, to induce chaotic resonance from the outside environment is challenging. Moreover, several studies reported abnormal neural activity caused by CCI. Recently, our study proposed that the double-Gaussian-filtered reduced region of orbit (RRO) method (abbreviated as DG-RRO), using external feedback signals to generate chaotic resonance, could control CCI with a lower perturbation strength than the conventional RRO method.MethodThis study applied the DG-RRO method to a model which includes excitatory and inhibitory neuron populations in the frontal cortex as typical neural systems with CCI behavior.Results and discussionOur results reveal that DG-RRO can be applied to neural systems with extremely low perturbation but still maintain robust effectiveness compared to conventional RRO, even in noisy environments.

Stochastic resonance is a representative phenomenon in which the degree of synchronization with a weak input signal is enhanced using additive stochastic noise. In systems with multiple chaotic attractors, the chaos-chaos intermittent behavior in attractor-merging bifurcation induces chaotic resonance, which is similar to the stochastic resonance and has high sensitivity. However, controlling chaotic resonance is difficult because it requires adjusting the internal parameters from the outside. The reduced-region-of-orbit (RRO) method, which controls the attractor-merging bifurcation using an external feedback signal, is employed to overcome this issue. However, the lower perturbation of the feedback signal requires further improvement for engineering applications. This study proposed an RRO method with more sophisticated and less perturbed feedback signals, called the double-Gaussian-filtered RRO (DG-RRO) method. The inverse sign of the map function and double Gaussian filters were used to improve the local specification, i.e., the concentration around the local maximum/minimum in the feedback signals, called the DG-RRO feedback signals. Owing to their fine local specification, these signals achieved the attractor-merging bifurcation with significantly smaller feedback perturbation than that in the conventional RRO method. Consequently, chaotic resonance was induced through weak feedback perturbation. It exhibited greater synchronization against weak input signals than that induced by the conventional RRO feedback signal and sustained the same level of response frequency range as that of the conventional RRO method. These advantages may pave the way for utilizing chaotic resonance in engineering scenarios where the stochastic resonance has been applied.