Effects of tongue cleaning on bacterial flora in tongue coating and dental plaque: a crossover study

BACKGROUND: The effects of tongue cleaning on reconstruction of bacterial flora in dental plaque and tongue coating itself are obscure. We assessed changes in the amounts of total bacteria as well as Fusobacterium nucleatum in tongue coating and dental plaque specimens obtained with and without tongue cleaning. METHODS: We conducted a randomized examiner-blind crossover study using 30 volunteers (average 23.7 ± 3.2 years old) without periodontitis. After dividing randomly into 2 groups, 1 group was instructed to clean the tongue, while the other did not. On days 1 (baseline), 3, and 10, tongue coating and dental plaque samples were collected after recording tongue coating score (Winkel tongue coating index: WTCI). After a washout period of 3 weeks, the same examinations were performed with the subjects allocated to the alternate group. Genomic DNA was purified from the samples and applied to SYBR® Green-based real-time PCR to quantify the amounts of total bacteria and F. nucleatum. RESULTS: After 3 days, the WTCI score recovered to baseline, though the amount of total bacteria in tongue coating was significantly lower as compared to the baseline. In plaque samples, the bacterial amounts on day 3 and 10 were significantly lower than the baseline with and without tongue cleaning. Principal component analysis showed that variations of bacterial amounts in the tongue coating and dental plaque samples were independent from each other. Furthermore, we found a strong association between amounts of total bacteria and F. nucleatum in specimens both. CONCLUSIONS: Tongue cleaning reduced the amount of bacteria in tongue coating. However, the cleaning had no obvious contribution to inhibit dental plaque formation. Furthermore, recovery of the total bacterial amount induced an increase in F. nucleatum in both tongue coating and dental plaque. Thus, it is recommended that tongue cleaning and tooth brushing should both be performed for promoting oral health

Functional Differentiation of Memory Retrieval Network in Macaque Posterior Parietal Cortex

SummaryHuman fMRI studies revealed involvement of the posterior parietal cortex (PPC) during memory retrieval. However, corresponding memory-related regions in macaque PPC have not been established. In this monkey fMRI study, comparisons of cortical activity during correct recognition of previously seen items and rejection of unseen items revealed two major PPC activation sites that were differentially characterized by a serial probe recognition paradigm: area PG/PGOp in inferior parietal lobule, along with the hippocampus, was more active for initial item retrieval, while area PEa/DIP in intraparietal sulcus was for the last item. Effective connectivity analyses revealed that connectivity from hippocampus to PG/PGOp, but not to PEa/DIP, increased during initial item retrieval. The two parietal areas with differential serial probe recognition profiles were embedded in two different subnetworks of the brain-wide retrieval-related regions. These functional dissociations in the macaque PPC imply the functional correspondence of retrieval-related PPC networks in macaques and humans

Complete maturation of the plastid protein translocation channel requires a type I signal peptidase

The protein translocation channel at the plastid outer envelope membrane, Toc75, is essential for the viability of plants from the embryonic stage. It is encoded in the nucleus and is synthesized with a bipartite transit peptide that is cleaved during maturation. Despite its important function, the molecular mechanism and the biological significance of the full maturation of Toc75 remain unclear. In this study, we show that a type I signal peptidase (SPase I) is responsible for this process. First, we demonstrate that a bacterial SPase I converted Toc75 precursor to its mature form in vitro. Next, we show that disruption of a gene encoding plastidic SPase I (Plsp1) resulted in the accumulation of immature forms of Toc75, severe reduction of plastid internal membrane development, and a seedling lethal phenotype. These phenotypes were rescued by the overexpression of Plsp1 complementary DNA. Plsp1 appeared to be targeted both to the envelope and to the thylakoidal membranes; thus, it may have multiple functions

Influence of petrographic textures on the shapes of impact experiment fine fragments measuring several tens of microns: Comparison with Itokawa regolith particles

In 2010, fine regolith particles on asteroid Itokawa were recovered by the Hayabusa mission. The three-dimensional microstructure of 48 Itokawa particles smaller than 120 µm was examined in previous studies. The shape distribution of Itokawa particles is distributed around the mean values of the axial ratio 2:√2:1, which is similar to laboratory impact fragments larger than several mm created in catastrophic disruptions. Thus, the Itokawa particles are considered to be impact fragments on the asteroid's surface. However, there have never been any laboratory impact experiments investigating the shapes of fine fragments smaller than 120 µm, and little is known about the relation between the shapes of fine fragments and the petrographic textures within those fragments. In this study, in order to investigate the relation between the petrographic textures and the shapes of fine fragments by impacts, the shapes of 2163 fine fragments smaller than 120 µm are examined by synchrotron radiation-based microtomography at SPring-8. Most samples are fine fragments from basalt targets, obtained in previous laboratory impact experiments by Michikami et al. (2016). Moreover, two impacts into L5 chondrite targets were carried out and the shapes of their fine fragments are examined for comparison. The results show that the shape distributions of fine fragments in basalt targets are similar regardless of impact energy per target mass (in contract to the shape distribution of relatively large fragments, which are affected by impact energy), and are similar to those in L5 chondrite targets and Itokawa regolith particles. The physical process producing these fine fragments would be due to multiple rarefaction waves in the target. Besides, the petrographic textures do not significantly affect the shapes of fine fragments in our experiments. On the other hand, according to Molaro et al. (2015), the shapes of the fragments produced by thermal fatigue by the day-night temperature cycles on the asteroid surface are influenced by the petrographic textures. Therefore, we conclude that the Itokawa particles are not the products of thermal fatigue but impact fragments on the asteroid surface

シンミツナ カンケイ ニオケル コミットメント ノ モデル ノ ガイカン

本稿では、恋愛関係や夫婦関係などの親密な関係におけるコミットメントの定義やモデルを概観した。先行研究におけるコミットメントのモデルの共通点として、関係維持についての動機づけであること、関係の将来についての展望や期待を含むこと、関係維持についての責任感や義務感を含むこと、魅力次元と抑止力次元が存在することの四点が挙げられた。また，相違点として、関係同一性、代替関係の質、関係維持活動をコミットメントそのものとするか、魅力次元と抑止力次元をどのように扱うかが挙げられた。これらの共通点と相違点に基づき、モデルの適切性を議論した。The purpose of this article was to review definitions and models of commitment to close relationships. Models of commitment in previous studies suggested four commonalities ： the motivation toward maintenance relationships, the foresight or expectation about future state of the relationships, the senses of responsibility or obligation to relationship maintenance and the presence of attraction and constraint. Furthermore, there were two different points; whether or not relationship identity, quality of alternative, and relationship maintenance act are commitment itself, and how attraction and constraint of commitment are treated with. We discussed the appropriateness of models of commitment based on these commonalities and difference points

What are differences among Dioxins, Benzopyrenes and indoles in terms of Toxicity through the Aryl hydrocarbon Receptor (AhR) system

Joint Research on Environmental Science and Technology for the Eart