Van Kampen-Flores theorem for cell complexes

The van Kampen-Flores theorem states that the $n$-skeleton of a $(2n+2)$-simplex does not embed into $\mathbb{R}^{2n}$. We give two proofs for its generalization to a continuous map from a skeleton of a certain regular CW complex (e.g. a simplicial sphere) into a Euclidean space. We will also generalize Frick and Harrison's result on the chirality of embeddings of the $n$-skeleton of a $(2n+2)$-simplex into $\mathbb{R}^{2n+1}$.Comment: 10 pages, some of the results (especially Theorem 1.4 and Corollary 1.5) were improved, final version, to appear in Discrete & Computational Geometr

求心性の歯周組織感覚入力により誘発された前頭前野の活動は咬合力を抑制する

The prefrontal cortex (PFC) plays an important role in several cognitive functions, such as planning, decision making, and social behavior. We previously reported that periodontal sensory input significantly increases PFC activity during the motor task of maintaining occlusal (biting) force. However, the relationships between periodontal sensation, PFC activity, and the performance of motor tasks, have not been evaluated in detail. Therefore, using functional near-infrared spectroscopy, we investigated PFC activity by monitoring changes in cerebral blood flow (CBF) to specific areas of the PFC that corresponded to changes in occlusal force generated during 4 different biting tasks: 1) occlusion with the central incisor with an interocclusal distance of 5 mm (BI-5 mm); or 2) 10 mm (BI-10 mm); 3) occlusion with the first molars with an interocclusal distance of 5 mm (BM-5 mm), or 4) 10 mm (BM-10 mm). Occlusion of molars generated increased PFC regional CBF as the interocclusal distance decreased (BM-10 mm vs BM-5 mm). No significant differences in CBF during occlusion of incisors were found when comparing 5 mm and 10 mm intercostal distances (BI-5 mm vs BI-10 mm). The mean occlusal force generated by BM-5 mm occlusion was significantly lower than that generated by BM-10 mm occlusion. Taken together, our results suggest that the PFC decreases efferent signaling to motor units, to reduce occlusal force generated when periodontal sensation, which is greater when the interocclusal distance is reduced, is primarily responsible for maintaining occlusal force in the absence of sensations from the temporomandibular joint and muscle spindles

A Dynamic Analysis of the Green Electricity Fund:Threshold Models Revisited

This study applies a threshold model proposed by Granovetter (1978) to analyze the dynamic diffusion process of donating behavior for renewable energy. Using data on people's willingness to donate for renewable energy under various predicted participation rates, we simulate how herd behavior spreads and the participation rate reaches the equilibrium. The participation rate at the equilibrium is estimated as 66.46% when the suggested donation is 500 yen, while it is 25.88% when the suggested amount is 1,000 yen. The influence of environmentalism and altruism is also examined, and we find that these motivations increase the participation rate 43.38% on average.Green electricity fund; Dynamic analysis; Contingent Valuation; Threshold model

Does Periodontal Tactile Input Uniquely Increase Cerebral Blood Flow in the Prefrontal Cortex?

We previously studied the effect of peripheral sensory information from sensory periodontal ligament receptors on prefrontal cortex (PFC) activity. In the dental field, an alternative dental implant without periodontal sensation can be applied for missing teeth. In this study, we examine whether periodontal tactile input could increase cerebral blood flow (CBF) in the PFC against elderly patients with dental implants lacking periodontal tactile (implant group), elderly individuals with natural teeth (elderly group), and young individuals with natural teeth (young group). The experimental task of maintaining occlusal force as closed-loop stimulation was performed. Compared with the young group, the elderly group showed significantly lower CBF. Contrastingly, compared with the young group, the implant group showed significantly lower CBF. There were no significant differences between the elderly and implant groups. Regarding the mean occlusal force value, compared with the young group and the elderly group, the implant group had a numerically, but not significantly, larger occlusal force exceeding the directed range. In conclusion, the periodontal tactile input does not uniquely increase PFC activity. However, increased CBF in the PFC due to the periodontal tactile input in the posterior region requires existing attention behavior function in the PFC

Application of artificial intelligence in the dental field : A literature review

Purpose: The purpose of this study was to comprehensively review the literature regarding the application of artificial intelligence (AI) in the dental field, focusing on the evaluation criteria and architecture types. Study selection: Electronic databases (PubMed, Cochrane Library, Scopus) were searched. Full-text articles describing the clinical application of AI for the detection, diagnosis, and treatment of lesions and the AI method/architecture were included. Results: The primary search presented 422 studies from 1996 to 2019, and 58 studies were finally selected. Regarding the year of publication, the oldest study, which was reported in 1996, focused on “oral and maxillofacial surgery.” Machine-learning architectures were employed in the selected studies, while approximately half of them (29/58) employed neural networks. Regarding the evaluation criteria, eight studies compared the results obtained by AI with the diagnoses formulated by dentists, while several studies compared two or more architectures in terms of performance. The following parameters were employed for evaluating the AI performance: accuracy, sensitivity, specificity, mean absolute error, root mean squared error, and area under the receiver operating characteristic curve. Conclusion: Application of AI in the dental field has progressed; however, the criteria for evaluating the efficacy of AI have not been clarified. It is necessary to obtain better quality data for machine learning to achieve the effective diagnosis of lesions and suitable treatment planning

”YARIKURI lessons” to develop thinking ability that can be used in daily life through understanding steam cooking.

今まで「蒸す」調理の学習では「蒸しケーキ」を作る等の調理実習を行ってきたが単発的な活動で終わってしまい学習したことを生活に生かすことができてないと感じた。そこで本研究では「蒸す」調理を理解し生活に生かせる思考を育むために「蒸す」という調理はどのような調理かどのような食材に適した調理かを実験を通して体験的に理解させその特徴を生かした「蒸し料理」を考えさせる授業実践を行った。Until now, In learning "steaming" cooking, we have practiced cooking such as making "steamed cakes". However, It ended up as a one-off experience, and I felt that I couldn't put what I learned to life. Therefore, In this study, in order to understand "steaming" cooking and foster thinking that can be utilized in daily life, we let students understand through experiments what kind of cooking "steaming" is and what kind of ingredients are suitable for it, we practiced lessons to make people think about "steamed dishes" that make the best use of their characteristics

Comparison between Two Assessment Tests for Oral Hygiene : Adenosine Triphosphate + Adenosine Monophosphate Swab Test and Bacteria Number Counting by Dielectrophoretic Impedance Measurement

Objective assessments of oral hygiene are important to prevent oral and systemic diseases. Two objective assessment tests are available to assess oral hygiene; (1) the adenosine triphosphate (ATP) + adenosine monophosphate (AMP) swab test, which incorporates a luciferase assay and (2) a bacteria count using the dielectrophoretic impedance measurement (DEPIM) method. In this study, we compared the two tests using a subjective visual assessment by professional clinicians and investigated the clinical significance of these tests. Twenty-seven young participants (mean age 26.3 ± 3.2 years) and twenty-seven older participants (mean age 75.1 ± 5.9 years) were recruited. Oral bacteria were sampled from three areas, including the tongue dorsum, the buccal mucosa, and the faucal mucosa, and saliva was obtained using a cotton swab. The amount of ATP + AMP and the number of bacteria were measured by each specific apparatus. Additionally, one examiner assessed the overall condition of oral hygiene using the visual analog scale (VAS). In the ATP + AMP swab test, the means were highest in saliva. For the bacteria count, the means were higher in the tongue dorsum and saliva and lower in the faucal and buccal mucosa. The results of the subjective assessment of oral hygiene indicated that the VAS-value was 3.78 ± 0.97 for the young group and 3.35 ± 0.81 for the older group. No significant difference was observed between the two groups. Additionally, no significant relationship between the values of the ATP + AMP swab test and the bacteria count was found for any of the four sample sites. In the older group, the subjective assessment of oral hygiene was significantly correlated with the values of the ATP + AMP swab test (multiple correlation coefficient = 0.723, p = 0.002). In conclusion, the values provided by the ATP + AMP swab test were not always correlated to the bacteria count. The results of this study suggest that the subjective assessment of oral hygiene was more highly correlated with the results of the ATP + AMP swab test, as compared to the bacterial count assay

Downsian Positions of Parties and Districts from the Numbers of Votes with Examples of Japanese Congressional Elections 1983 - 2004

This paper proposes, under assumptions of sincere voters with some additional conditions, to calculate the positions of parties and districts by “solving” a system of equations whose left hand sides are theoretical predictions and theright hand sides are the actual numbers of votes gained by the parties in the districts. The positions of parties and prefectures are calculated for the seats for the proportional representation in the Japanese congressional elections 1983 – 2004. The result reveals that the competition in these elections was not between the right and the left, but between the urban and the rural

Reliability of Screening Methods to Diagnose Oral Dryness and Evaluate Saliva Secretion

In this study, we evaluated the reliability and reproducibility of widely implemented salivary flow rate and oral dryness tests. In experiment 1, twenty young and healthy Japanese participants volunteered to participate. For each participant, the oral moisture (OM) level, unstimulated whole saliva volume (U-WSV), and stimulated whole saliva volume (S-WSV) were measured at the same time on two separate days. In experiment 2, twenty-seven patients who were over 65 years of age volunteered to participate. The OM level and U-WSV were measured at the same time on two separate days. In Experiment 1, the intra-class correlation coefficients (ICCs) corresponding to the S-WSV, U-WSV, and OM level were 0.23, 0.28, and 0.16, respectively, for the young participants. In Experiment 2, the ICCs corresponding to the U-WSV/spitting and OM level were 0.83 and 0.12, respectively, for the older participants. The results of Bland–Altman analysis confirmed the absence of systematic error, with the exception of the OM level results in Experiment 2, which indicated systematic bias. In conclusion, we believe that there is currently no consistent and reliable screening test for assessing salivary flow rate and oral dryness, although the spitting test was determined to be highly reliable