Faunal activity rhythms influencing early community succession of an implanted whale carcass offshore Sagami Bay, Japan

Benthic community succession patterns at whale falls have been previously established by means of punctual submersible and ROV observations. The contribution of faunal activity rhythms in response to internal tides and photoperiod cues to that community succession dynamism has never been evaluated. Here, we present results from a high-frequency monitoring experiment of an implanted sperm whale carcass in the continental slope (500 m depth) offshore Sagami Bay, Japan. The benthic community succession was monitored at a high frequency in a prolonged fashion (i.e. 2-h intervals for 2.5 months) with a seafloor lander equipped with a time-lapse video camera and an acoustic Doppler profiler to concomitantly study current flow dynamics. We reported here for the first time, to the best of our knowledge, the occurrence of strong 24-h day-night driven behavioral rhythms of the most abundant species (Simenchelys parasitica; Macrocheira kaempferi, and Pterothrissus gissu). Those rhythms were detected in detriment of tidally-controlled ones. Evidence of a diel temporal niche portioning between scavengers and predators avoiding co-occurrence at the carcass, is also provided. The high-frequency photographic and oceanographic data acquisition also helped to precisely discriminate the transition timing between the successional stages previously described for whale falls’ attendant communities.

Factors related to dissociation between objective and subjective masticatory function in Japanese community-dwelling elderly adults

Clinicians' evaluations of older adults sometimes reveal inconsistencies between objective and subjective dental status. This study investigated which factors contribute both to good objective masticatory function (OMF) and the poor subjective masticatory function (SMF) that often becomes a clinical issue. Study participants included 635 elderly community-dwelling Japanese adults who underwent a comprehensive geriatric health examination in 2012. SMF was assessed with a question from the Kihon Checklist on eating difficulties (poor or good). OMF was assessed by a colour-changing gum (poor or good). Also investigated were age, sex, depressive symptoms, instrumental activities of daily living (I-ADLs), number of people who joined the participant at dinner, grip strength, usual walking speed, number of remaining teeth, number of functional teeth and their occlusal force. The group with good OMF and good SMF, defined as group 1, and the group with good OMF but poor SMF, group 2, were compared. Logistic regression analyses confirmed that the number of remaining and functional teeth participants had was statistically unrelated to differences between OMF and SMF. Instead, differences were related to stronger depressive symptoms (OR = 1.67, CI = 1.14-2.44), less ability to conduct I-ADL activities (OR = 0.73, CI = 0.59-0.91), slower usual walking speeds (OR = 0.18, CI = 0.06-0.58) and less occlusal force (OR = 0.99, CI = 0.99-1.00). Depressive symptoms, I-ADLs, and physical function are shown to be significantly related to divergence between objective and subjective masticatory function in elderly Japanese. This suggests that dissociations between objective and subjective dental evaluations of elderly adults indicate need for assessment of their mental and physical function.

Frailty Severity and Dietary Variety in Japanese Older Persons: A Cross-Sectional Study

Providing older person individuals with an appropriate intervention at the time of frailty onset is important to prevent the progression of the condition and the need for long-term care. However, the proper timing of starting nutritional and dietary interventions for frail older person subjects has not been fully elucidated. Therefore, in this cross-sectional study, we aimed to clarify the association between frailty and dietary variety among older persons in Japan. We surveyed sex, age, body height, body weight, body mass index, serum albumin level, dietary variety, and nutritional intake indexes in 747 community-dwelling older person individuals who underwent a comprehensive health examination in October 2014. Frailty was determined using the Kihon Checklist (25 questions). Kihon Checklist is widely used to assess frailty in Japan, and their physical, cognitive and social function was evaluated. After excluding those who did not complete the Kihon Checklist and those who required long-term care, frailty status was analyzed in 665 older person individuals. The numbers and percentages of frail, pre-frail and robust older persons were found to be 77 (11.6%), 182 (27.4%) and 406 (61.0%) respectively. Significant differences among robust, pre-frail, and frail subjects were observed in terms of age, serum albumin level, alcohol consumption, smoking, and history of diabetes. Among the nutrition-related indexes, only the dietary variety showed a significant difference. The results of ordinal logistic regression analysis showed a significant association between frailty and sex, age, smoking status, diabetes, and dietary variety score. Dietary variety was significantly associated with the progression of frailty among older persons in the community.