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Affiliative behavior in social animals may have several functions such as maintaining social bonds, reducing tensions, or restoring relationships. Common bottlenose dolphins (Tursiops truncatus) engage in several affiliative behaviors, including parallel swimming, contact swimming, and flipper rubbing. Dolphins affiliate with former opponents after aggression, suggesting that this is a function of tension reduction. This study investigated how affiliative behaviors occur after aggression. Parallel swimming occurred more frequently than expected after aggression, while contact swimming and flipper rubbing occurred less frequently than expected. Parallel swimming and contact swimming occurred immediately after aggression; in contrast, flipper rubbing tended to occur more than one minute after aggression. These results suggest that common bottlenose dolphins engage in parallel swimming and contact swimming when social tension increases. The function may differ among these affiliative behaviors, and dolphins may engage in specific affiliations after aggression.

The exchange of prosocial behaviors such as grooming may be affected by several factors, including the social structure and social relationships of the individuals. However, studies on the reciprocity of prosocial affiliative behaviors in non-primate animals are limited. Flipper rubbing is considered a prosocial affiliative behavior in dolphins. We investigated the reciprocity of flipper rubbing and tested the following hypotheses in common bottlenose dolphins: trade for tolerance, trade for a reduction in renewed aggressions, the value of flipper rubbing partner, and reciprocity over short and long time frames. There was no correlation between the frequency of flipper rubbing and aggression. Age difference did not affect reciprocal flipper rubbing. Flipper rubbing by former opponents did not increase after aggression. Dolphins did not provide flipper rubbing immediately after receiving flipper rubbing. The exchange of flipper rubbing was more reciprocal over long time frames than over short time frames. Dolphins preferentially rubbed the individuals who rubbed them the most. Pairs who performed flipper rubbing more frequently partook in more reciprocal flipper rubbing than pairs who performed flipper rubbing less frequently. Results suggest that bottlenose dolphins maintain flipper rubbing reciprocity over the long-term via partner choice based on an emotional bookkeeping system.

高校女子バレーボール部に実施したメディカルチェックの概要と振り返りをまとめることを第1の目的とした．次にチームの指導者に対してインタビュー調査をおこない，医療者側と指導者側の共通点や相違点を明らかにすることを第2の目的とした．メディカルチェックによって障害の把握ができ，医療機関と学校との連携を促進することができた．インタビューで指導者は早期発見や，教育的観点からも考えていることが明らかになった．, The first objective of this study was to summarize the contents of the medical checkups conducted on the high school women volleyball team. The second objective was to conduct an interview survey with the team's instructors to clarify the similarities and differences between the medical staffs and instructors. The medical checkup enabled us to understand the disorder and to promote cooperation between the medical institution and the school. In the interviews, it became clear that the instructors considered not only early detection but also educational perspectives to be important., 原著(Original paper)

In this study, we cloned the ATP-binding cassette (ABC) subfamily G member 2 gene (Abcg2 gene; breast cancer resistance protein) from the liver of the marine pufferfish Takifugu rubripes, and examined its tissue distribution and gene structure. The full-length complementary DNA (cDNA) was 1977 base pairs (bp), comprising 15 exons in chromosome 17, and was assigned to the teleost Abcg2b paralogue. The open reading frame was 1839 bp in length, and encodes 612 amino acids constituting Walker A, Q-loop, C motif, Walker B, D-loop, and H-loop sequences in the first half and six transmembrane domains in the second half. Gene expression of Abcg2 was predominantly found in the intestines, followed by the liver and kidneys. The Kozak motif and the polyadenylation signal sequences were at respective ends of the transcript. The putative core promoter sequences including the transcription factor II B recognition elements, the TATA box, the initiator element, and the downstream core promoter element were found in the transcript and its upstream genomic DNA sequence. The hypoxia response element and the estrogen response element were located in the upstream genomic DNA sequence, suggesting that the pufferfish Abcg2 gene possesses the same regulation mechanism of transcription as the human ABCG2 gene.

Human herpesvirus 6A (HHV-6A) and HHV-6B use different cellular receptors, human CD46 and CD134, respectively, and have different cell tropisms, although they have 90% similarity at the nucleotide level. An important feature that characterizes HHV-6A/6B is the glycoprotein H (gH)/gL/gQ1/gQ2 complex (a tetramer) that each virus has specifically on its envelope. Here, to determine which molecules in the tetramer contribute to the specificity for each receptor, we developed a cell-cell fusion assay system for HHV-6A and HHV-6B that uses cells expressing CD46 or CD134. With this system, when we replaced the gQ1 or gQ2 of HHV-6A with that of HHV-6B in the tetramer, the cell fusion activity mediated by glycoproteins via CD46 was lower than that seen with the original-type tetramer. When we replaced the gQ1 or the gQ2 of HHV-6A with that of HHV-6B in the tetramer, the cell fusion mediated by glycoproteins via CD134 was not seen. In addition, we generated two types of C-terminal truncation mutants of HHV-6A gQ2 (AgQ2) to examine the interaction domains of HHV-6A gQ1 (AgQ1) and AgQ2. We found that amino acid residues 163 to 185 in AgQ2 are important for interaction of AgQ1 and AgQ2. Finally, to investigate whether HHV-6B gQ2 (BgQ2) can complement AgQ2, an HHV-6A genome harboring BgQ2 was constructed. The mutant could not produce an infectious virus, indicating that BgQ2 cannot work for the propagation of HHV-6A. These results suggest that gQ2 supports the tetramer's function, and the combination of gQ1 and gQ2 is critical for virus propagation. IMPORTANCE Glycoprotein Q2 (gQ2), an essential gene for virus propagation, forms a heterodimer with gQ1. The gQ1/gQ2 complex has a critical role in receptor recognition in the gH/gL/gQ1/gQ2 complex (a tetramer). We investigated whether gQ2 regulates the specific interaction between the HHV-6A or -6B tetramer and CD46 or CD134. We established a cell-cell fusion assay system for HHV-6A/6B and switched the gQ1 or gQ2 of HHV-6A with that of HHV-6B in the tetramer. Although cell fusion was induced via CD46 when gQ1 or gQ2 was switched between HHV-6A and -6B, the activity was lower than that of the original combination. When gQ1 or gQ2 was switched in HHV-6A and -6B, no cell fusion was observed via CD134. HHV-6B gQ2 could not complement the function of HHV-6A's gQ2 in HHV-6A propagation, suggesting that the combination of gQ1 and gQ2 is critical for regulating the specificity of the tetramer's function for virus entry.

One-dimensional TiO2 nanotube (TNT) arrays were fabricated on fluorine-doped tin oxide glass substrate as the photoanodes for dye-sensitized solar cells (DSCs) using one-step ZnO nanorods template method. The depth profile analysis using X-ray photoelectron spectroscopy and ion sputtering indicated that a small amount of Zn species was attached on the TNT surface. Relationship of the properties of the TNT surface with the Zn residue and the photovoltaic characteristics of DSCs were investigated. Residual Zn species on TNT improve the open circuit voltage of the DSCs. A maximum open circuit voltage of 0.876 V was achieved, which is close to the theoretical maximum of the TiO2-based DSCs. However, photocurrent density was decreased significantly for the high-Zn-amount sample. It was revealed that the surface Zn species were divalent oxides and the amount of surface hydroxyl group was increased in conjunction with the Zn amount. Slight increase of the dye amount was found for the high Zn amount sample. It was expected that decrease in injection probability of the photo-excited electrons into TNT was the dominant reason for the photocurrent decrease.

In comparison with terrestrial animals, such as primates, there is limited empirical evidence for cooperative behavior in marine mammals under experimental conditions. In this study, we used a cooperative rope-pulling task to investigate how bottlenose dolphins (Tursiops truncatus) coordinate their behavior with a partner. Dolphins successfully learned and were able to perform the task, even when one subject started after the other. In the no-delay condition (i.e., both subjects sent at the same time), one pair of dolphins showed coordinated behaviors. When pairs were successful in solving the task in the delay condition (i.e., one individual sent later than the other), the initiators (i.e., first individual sent) were likely to wait for the follower to arrive, and the follower was likely to swim faster when the initiator did not wait and started pulling the rope alone. These coordinated behaviors might help resolve the given cooperative task. Our results suggest that bottlenose dolphins learn to coordinate their behaviors via trial and error and recognize the necessity of performing simultaneous actions with a partner to successfully accomplish cooperative tasks. In addition, both partners showed behavioral changes over many trials of no-delay and delay conditions, suggesting that bidirectional coordination occurred in the cooperative task., ハンドウイルカがおたがいに協力しあうことを発見. 京都大学プレスリリース. 2019-10-25.

Post-conflict affiliations initiated by bystanders (bystander affiliation) toward aggressors or victims have been suggested to represent the function of conflict management in some social living species. However, the function of bystander affiliations toward aggressors and victims has not been examined in marine mammals. In the present study, we investigated the function of bystander affiliations to aggressors and victims in bottlenose dolphins: self-protection, the substitute of reconciliation, social facilitation and tension relief of opponents. These bystander affiliations did not reduce post-conflict attacks by former opponents against group members. Bystander affiliation to aggressors tended to be performed by a bystander who had an affiliative relationship with the aggressor but not with the victim. Bystander affiliation to victims also tended to be initiated by a bystander who had an affiliative relationship with the victim but not the aggressor and was close to former opponents at the end of aggressions. Affiliation among group members who stayed near former opponents during aggressions did not increase after aggressions compared to that under control conditions. Renewed aggressions between former opponents decreased after bystander affiliations in our previous study. Bystanders who showed social closeness to former opponents may initiate bystander affiliation toward their affiliative former opponents because they may feel emotion, such as anxiety and excitement, of former opponents. Bystander affiliation toward aggressors and victims may function as tension relief between former opponents. Bystanders of bottlenose dolphins, who may have a relaxed dominant style, might initiate post-conflict affiliation to affiliative individuals unaffected by the dominance relationships among them, unlike despotic species, Scientific reports, 10(1), art.no.3776; 2020

Reconciliation, post-conflict affiliation between former opponents, was suggested to repair the relationship between former opponents. The number of times that each former opponent initiates reconciliation may be affected by the dominance style. Despotic dominance style was suggested to restrain the initiation of reconciliation by recipients of aggression, unlike relaxed dominance style. Although reconciliation was suggested to restore relationships, reconciliation sometimes did not occur. The valuable relationship hypothesis predicts that reconciliation is more likely to occur when former opponents share a valuable relationship. However, few studies have tested this hypothesis in non-primate species. This study investigated, in captive bottlenose dolphins, which are suggested as having a relaxed dominance style, whether aggressors or recipients of aggression initiate reconciliation, and whether relationships between former opponents affect the occurrence of reconciliation. The number of times that aggressors or recipients of aggression initiate reconciliation did not differ. Recipients of aggression initiated reconciliation sooner than aggressors. These results support the prospect that recipients of aggression are not impeded in initiating reconciliation in relaxed species. Former opponents who share a more affiliative relationship were reconciled more frequently. Bottlenose dolphins were suggested to receive the benefits from individuals who shared more affiliative relationships. The valuable relationship hypothesis may be supported in bottlenose dolphins.

Post-conflict affiliation between former opponents or between one of the former opponents and bystanders might have the function of conflict management, which reduces the costs associated with aggressions. One of the suggested functions of post-conflict affiliation is decreased renewed aggressions directed from aggressors to victims. However, the effect of post-conflict affiliation on renewed aggressions by victims has not been investigated. We examined whether post-conflict affiliations decreased the number of renewed aggressions initiated by winners or losers in captive bottlenose dolphins. Both winners and losers initiated renewed aggressions. However, these aggressions decreased after post-conflict affiliation between former opponents, initiated by bystanders to winners, initiated by losers to bystanders, and initiated by bystanders to losers. Post-conflict affiliation between former opponents is suggested to function as reconciliation. Post-conflict affiliation initiated by losers to bystanders is suggested to function as the protection of losers. Post-conflict affiliations initiated by bystanders to one of former opponents are suggested to function as both appeasement and protection of the opponent who affiliates with bystanders., Scientific Reports, 5, 14275; 2015

Several terrestrial animals and delphinids manipulate objects in a tactile manner, using parts of their bodies, such as their mouths or hands. In this paper, we report that bottlenose dolphins (Tursiops truncatus) manipulate objects not by direct bodily contact, but by spontaneous water flow. Three of four dolphins at Suma Aqualife Park performed object manipulation with food. The typical sequence of object manipulation consisted of a three step procedure. First, the dolphins released the object from the sides of their mouths while assuming a head-down posture near the floor. They then manipulated the object around their mouths and caught it. Finally, they ceased to engage in their head-down posture and started to swim. When the dolphins moved the object, they used the water current in the pool or moved their head. These results showed that dolphins manipulate objects using movements that do not directly involve contact between a body part and the object. In the event the dolphins dropped the object on the floor, they lifted it by making water flow in one of three methods: opening and closing their mouths repeatedly, moving their heads lengthwise, or making circular head motions. This result suggests that bottlenose dolphins spontaneously change their environment to manipulate objects. The reason why aquatic animals like dolphins do object manipulation by changing their environment but terrestrial animals do not may be that the viscosity of the aquatic environment is much higher than it is in terrestrial environments. This is the first report thus far of any non-human mammal engaging in object manipulation using several methods to change their environment., PLoS ONE, 9(9), e107796; 2014

We attempted to fabricate a high-quality Fe3O4 film while satisfying both low-thermal preparation (≦573 K) and film thinness (≦500 A). X-ray diffractometry showed that our prepared Fe3O4 film was epitaxially grown onto a MgO (100) substrate. The saturation magnetization, resistivity, and Verwey point were, respectively, ∼438 emu/cm3, ∼10 000 μ Ω cm, and ∼110 K. These values were comparable to those of the Fe3O4 bulk. Our experimental results suggested that a high-quality Fe3O4 film could be obtained even under the crucial conditions of the deposition temperature being low (∼523 K) and the film being ultrathinned (∼100 A).