Time filter

Source Type

Onozuka D.,Fukuoka Institute of Health Environmental | Hashizume M.,Nagasaki University | Hagihara A.,Kyushu University
Epidemiology and Infection | Year: 2010

Although multiple combinations of weather variability may contribute to an increased incidence of infectious gastrointestinal disease, few studies have investigated the association between weather variability and cases of infectious gastroenteritis. We acquired data for infectious gastroenteritis cases and weather variability in Fukuoka, Japan, from 1999 to 2007 and used time-series analysis to assess the effects of weather variability on infectious gastroenteritis cases, adjusting for confounding factors. In total, 422 176 infectious gastroenteritis cases were reported during the 9-year study period. The weekly number of infectious gastroenteritis cases increased by 77% (95% CI 46-108) for every 1C increase in the average temperature and by 23% (95% CI 14-31) for every 1% decrease in relative humidity. From 1999 to 2007, infectious gastroenteritis cases increased significantly with increased average temperature and decreased relative humidity in Fukuoka, Japan. © 2009 Cambridge University Press.

Itoh H.,Kyushu University | Narazaki Y.,Fukuoka Institute of Health Environmental
Atmospheric Chemistry and Physics | Year: 2016

By using high concentrations of 7Be as an indicator, we clarify fast descent routes from within or near the stratosphere to Earth's surface, with the study site being in Fukuoka, Japan. Most routes arise from high latitudes through the following processes. First, the descent associated with a tropopause fold occurs, followed by southward movement with slow descent at the rear side of a strong trough. Because this motion occurs along an isentropic surface, the descending air parcels nearly conserve the potential temperature. As an extension, a strong descent associated with a sharp drop in the isentropic-surface height occurs at the southern edge of the trough; this transports air parcels to low altitudes. This process involves irreversible phenomena such as filamentation and cutoff of potential vorticity. Finally, upon meeting appropriate near-surface disturbances, parcels at low altitudes are transported to Earth's surface.In some cases, parcels descend within midlatitudes. In such routes, because the potential temperature is much higher at high altitudes than at low altitudes, descent with conservation of the potential temperature is impossible, and the potential temperature decreases along the trajectories through mixing.The prevalence of the high-latitude route is explained as follows. In the midlatitude route, because parcels at high and relatively low altitudes mix, the high concentrations of 7Be included in high-altitude parcels are difficult to maintain. Therefore, for parcels to arrive at low altitudes in the midlatitude while maintaining high concentrations of 7Be, i.e., conserving the potential temperature, their area of origin should be high altitudes in high latitudes where the potential temperature is almost the same as that in the arrival area. In spring, tropopause folds are frequent in high latitudes, disturbances in the southward transport of parcels are strong, and disturbances occur by which parcels descend to the surface. Therefore, high concentrations of 7Be occur most frequently in spring. © Author(s) 2016.

Onikura N.,Kyushu University | Nakajima J.,Fukuoka Institute of Health Environmental
Journal of Applied Ichthyology | Year: 2013

In Japan, Pseudorasbora parva has not been negatively affected by artificial changes in its habitat. Ecological traits of the species may explain this easy adaptation to artificial habitats. An ecological investigation of P. parva inhabiting irrigation ditches was conducted monthly for approximately two years on northwestern Kyushu Island, Japan. Measurements of 1927 individuals revealed two size classes, maturation age (1 year), and lifespan (1-2 years). Results of this study and previous studies show that the species exhibits life history plasticity. In addition, habitat use of ditches indicates that abundances correlated positively with water temperature and negatively with current velocity in the crop-growing season, and positively with water depth and negatively with current velocity in the fallow season. Structural factors such as ditch revetment conditions and aquatic macrophyte cover were unimportant for this species. The study shows that the gudgeon adapts to artificial ditches easily and successfully because of both life history plasticity and wide-scale use of the habitat. © 2012 Blackwell Verlag GmbH.

Onozuka D.,Fukuoka Institute of Health Environmental | Hashizume M.,Nagasaki University
Epidemiology and Infection | Year: 2011

Investigations of the relationship between weather variability and infectious gastroenteritis (IG) are becoming increasingly important in light of international interest in the potential health effects of climate change. However, few studies have examined the impact on children, despite the fact that children are considered particularly vulnerable to climate change. We acquired data about cases of IG in children aged <15 years and about weather variability in Fukuoka, Japan from 2000 to 2008 and used time-series analyses to assess how weather variability affected IG cases, adjusting for confounding factors. The temperature-IG relationship had an inverted V shape, with fewer cases at temperatures lower and higher than ∼13°C. Every 1°C increase in temperature below the threshold (13°C) was associated with a 23·2% [95% confidence interval (CI) 16·6-30·2] increase, while every 1°C increase in temperature above the threshold (13°C) was associated with an 11·8% (95% CI 6·6-17·3) decrease in incidence. The increase in cases per 1% drop in relative humidity was 3·9% (95% CI 2·8-5·0). The percentage increase of IG cases was greatest in the 0-4 years age group and tended to decrease with increasing age. We found a progressive reduction in weather-related IG cases in children aged >4 years. Our results suggest that public health interventions aimed at controlling weather-related IG may be most effective when focused on young children. © Copyright Cambridge University Press 2010.

Nakajima J.,Fukuoka Institute of Health Environmental
Zootaxa | Year: 2012

Three new species and six new subspecies of the genus Cobitis from the western part of the Japanese archipelago are described: Cobitis kaibarai sp. nov., Cobitis magnostriata sp. nov., Cobitis minamorii sp. nov., Cobitis striata fuchigamii subsp. nov., Cobitis striata hakataensis subsp. nov., Cobitis minamorii oumiensis subsp. nov., Cobitis minamorii tokaiensis subsp. nov., Cobitis minamorii saninensis subsp. nov., and Cobitis minamorii yodoensis subsp. nov. Cobitis striata Ikeda, 1936 was redescribed on the basis of specimens collected from the type locality. The four striated spined loaches, C. striata, C. kaibarai, C. magnostriata, and C. minamorii were clearly distinguished by the pelvic myotome number, shape of the lamina circularis, black spots at the caudal base, body shape, and egg diameter. Although these subspecies of C. striata and C. minamorii are remarkably alike in morphology, the adult males of the subspecies had different longitudinal patterns of pigmentation during the non-spawning season. Copyright © 2001-2012 Magnolia Press.

Discover hidden collaborations