Vertical distribution of Pyrodinium bahamense var. compressum (Dinophyceae) cysts in Ambon Bay and Hurun Bay, Indonesia

Pyrodinium bahamense var. compressum (Pbc) is one of the causative species of Paralytic Shellfish Poisoning (PSP). Incidents of PSP and red tides caused by Pbc are increasing, as well as the geographic distribution of Pbc expanding in Southeast Asia, where it has recently occurred in several areas that previously have not experienced blooms, such as Ambon Bay and Lampung Bay in Indonesia. Five factors including anthropogenic activities, natural activities, visual realization with red tide discoloration, development of techniques like RNA sequence and ELISA toxin kits, and the establishment of a regular monitoring system have been suggested to have led to the increase in reports of dinoflagellate blooms. Occurrence of dinoflagellate cysts in sediments has been used as evidence to which species of vegetative cells occurred in the water column. In this study, the vertical distribution of dinoflagellate cysts in sediments was investigated to confirm the first occurrence of Pbc cysts and to examine the floral changes of dinoflagellate cysts in Ambon Bay and Hurun Bay, Indonesia. In Ambon Bay, Pbc cysts first occurred in ca. 1850 and the cysts were continuously observed since ca. 1870. In Hurun Bay, Pbc cysts were found at 50-52 cm depth, and also at 42-44 cm depth. Cysts of Pbc first occurred at least in 1883, using depositional age calculated from the historical eruption of Mt. Krakatau. Cysts of Pbc have continuously occurred since ca. 1910, and the cyst densities rapidly increased in ca. 1960. Based on these findings, we consider that anthropogenic activities such as ballast water and transportation of shellfish seeds probably did not cause the introduction of Pbc in both bays

Suppression of Alzheimer's Disease-Related Phenotypes by Geranylgeranylacetone in Mice

Amyloid-beta peptide (A beta) plays an important role in the pathogenesis of Alzheimer's disease (AD). A beta is generated by the secretase-mediated proteolysis of beta-amyloid precursor protein (APP), and cleared by enzyme-mediated degradation and phagocytosis. Transforming growth factor (TGF)-beta 1 stimulates this phagocytosis. We recently reported that the APP23 mouse model for AD showed fewer AD-related phenotypes when these animals were crossed with transgenic mice expressing heat shock protein (HSP) 70. We here examined the effect of geranylgeranylacetone, an inducer of HSP70 expression, on the AD-related phenotypes. Repeated oral administration of geranylgeranylacetone to APP23 mice for 9 months not only improved cognitive function but also decreased levels of A beta, A beta plaque deposition and synaptic loss. The treatment also up-regulated the expression of an A beta-degrading enzyme and TGF-beta 1 but did not affect the maturation of APP and secretase activities. These outcomes were similar to those observed in APP23 mice genetically modified to overexpress HSP70. Although the repeated oral administration of geranylgeranylacetone did not increase the level of HSP70 in the brain, a single oral administration of geranylgeranylacetone significantly increased the level of HSP70 when A beta was concomitantly injected directly into the hippocampus. Since geranylgeranylacetone has already been approved for use as an anti-ulcer drug and its safety in humans has been confirmed, we propose that this drug be considered as a candidate drug for the prevention of AD

Common coypu predation on unionid mussels and terrestrial plants in an invaded Japanese river

The coypu (Myocastor coypus) is a semi-aquatic herbivorous rodent that has been suspected to prey on freshwater unionid mussels in Japan. Fecal DNA metabarcoding that targeted bivalves and terrestrial plants was performed to examine the diet of exotic coypu in the Kiso River, central Japan. Thirty-two fecal samples from four floodplain waterbodies were collected seasonally. In one of the waterbodies, live and dead mussels were investigated to examine the possible effects of coypu predation on mussel population structures. Common coypu predation on unionid mussels was confirmed in two waterbodies. Midden surveys showed that medium- to large-sized mussels tended to be consumed by coypu; possibly resulting in population structures with few large-sized individuals. Seasonal diet selection of terrestrial plants was also detected: two perennial plants were consumed throughout the year, whereas some perennial plants were consumed seasonally. The number of terrestrial plant species/taxa as primary food was higher in summer than in winter, which was attributed to the high consumption of annual plants in the summer. Future studies need to examine the exhaustive diet of coypu including other animals and plants, as well as its effects on freshwater ecosystems in invaded regions

HORIZONTAL DISTRIBUTION OF DINOFLAGELLATE CYSTS IN SURFACE SEDIMENTS OF JAKARTA BAY: SOME PRELIMINARY RESULTS

Ten surface sediment samples were collected from Jakarta Bay to study the horizontal distribution of dinoflagellate resting cysts in this area. Overall results had shown unique species composition and diversity of dinoflagellate cyst assemblages. However, dinoflagellate cysts found in this preliminary research were sparse and relatively low in term of species number and concentrations. Twenty cyst morphophites were identified in this research, within which ten cysts belong to autotrophic and another ten belong to heterotrophic species. Protoperidinium cysts were the most diversified group, predominating in almost the sampling locations. The cysts identified were generally characterized by species belonged to three orders namely Gonyaulacales, Gymnodiniales, and Peridiniales. Only one dinoflagellate cyst found that was belonged to the toxic and harmful algal bloom (HAB) member species, i.e. Gymnodinium catenatum

Association between duration of excessive weight and arterial stiffness in middle-aged and older adults

This study aims to evaluate the association between duration of overweight/obesity and arterial stiffness. In total, 103 men and women aged 45–68 years with a body mass index (BMI) of ≥25 kg/m2 were enrolled in this study. Duration of overweight/obesity was calculated for individuals with at least two consecutive BMI occurrences of ≥25 kg/m2 in the previous (5-year intervals from 20 years old) and present BMI information. Multiple regression analysis showed that carotid-femoral pulse wave velocity, an index of arterial stiffness, was independently associated with the duration of overweight/obesity, but not with current degree of overweight/obesity