The vital statistics of Japan do not include a category for mortality statistics using the term “heat stroke.” “Exogenous causes of injury and death” included the items “excessive heat (E900)” until 1994 along with “exposure to excessive nature heat (X30)” and “exposure to excessive heat of man-made origin (W92)” from 1995. The mortality counts of heat stroke is thought to be the mortality counts due to heat among these exogenous causes. According to the press release materials of the Ministry of Health, Labor and Welfare (MHLW), the mortality counts due to “exposure to excessive natural heat (X30)” should be the mortality counts of heat stroke. However, the “influence of exogenous causes of injury, intoxication, and others” included the subcategories “effects of heat (N992)” and “effects of heat and light (992)” until 1994 along with the “effects of heat and light (T67)” from 1995, which describes the specific symptoms of heat exhaustion such as heat stroke and sunstroke. Consequently, we believe the counts of T67, as the nature of injuries, is equivalent to the mortality counts of heat stroke. This study compared the mortality counts related to heat stroke regarding these statistical categories. There was no significant difference in the mortality counts between statistical categories until 1994. From 1995 to 2017, T67 was higher than X30, such that adding X30 to W92 made the difference between T67 and X30+W92 smaller. The possible cause for this is that E900 as a code of exogenous causes was divided into X30 and W92 from 1995. In the case of the mortality counts due to heat, we believe it is more appropriate to use the mortality counts in terms of the nature of injuries, rather than using the mortality counts due to excessive heat in nature (classification by causes). It is assumed that the mortality counts due to the “effects of heat and light (T67)” indicates the mortality counts of heat stroke in Japan.

The stem sap flow (SF) of pioneer species was measured in a 15-year-old secondary forest in a suburb of Manaus, Amazonas, by means of the Granier Method. The hydraulic conductivity was converted into the stand-level evapotranspiration in combination with the sapwood area of stem transection in order to compare the conditions between dry and rainy seasons (30 days each). It was found that the SF had the same phase as the vapor pressure deficit (VPD) in both seasons, but the daily amount in rainy season was larger than that in dry season (dry season: 12.4 l/day, rainy season: 14.9 l/day), which was inverse to VPD. When comparing the periods with similar downward short-wave radiation (dry season: 597W/m², rainy season: 609W/m²), it was found that the SF was larger in rainy season (36.9 l/day) than in dry season (27.7 l/day). It is well-known that the SF basically depends on VPD, but an inverse relationship was found in this study. The relationship resulted from the differences in soil water content (e.g. 0.28m³/m³ in dry season, 0.37m³/m³ in rainy season at a depth of 80cm in soil), and it influenced the sap flow of juvenile trees with shallow roots. Because the aboveground biomass was still small, the amount of evapotranspiration remained to be 1.0mm/day in dry season and 1.2mm/day in rainy season, which was smaller than that in savanna regions.

Chlorogenic acids (CGA), the major compound of coffee polyphenols, show an anti-hypertension activity in an endothelium dependent manner. In this study, we investigated the effects of ingesting CGA on peripheral skin temperature (SkT) and skin blood flow (SkBF) after a cold stress test. A double-blind, randomized, placebo-controlled, crossover intervention study was conducted on Japanese healthy women. A cold stress (water temperature of 15°C, 1 min) test was performed on both hands of each subject 50 minutes after ingesting 270 mg of CGA and placebo with 1 week washout period. SkT and SkBF were then measured simultaneously before the cold stress and at 2.5-minute intervals for 30 minutes after cold stress test. Twenty-four subjects were enrolled and ramdomized into two groups. Twenty-one of these subjects completed this study. Significant improvement of the recovery of SkT and SkBF after the cold stress test were observed in CGA compared with placebo. These findings suggested that the ingestion of CGA improves SkT and SkBF after cold stress.

We investigated the O₃ concentration by the solar term and stream chemistry around the Mt. Gokurakuji, Hiroshima prefecture, where the forest decline was reported. The concentration of O₃ for the three years was 24.6 ppb on average, and it was at the same level as that of Tokyo Tower, the metropolitan area. Cl- concentration of water streams around the Mt. Gokurakuji were 90.4μM on average, quarter as high as that coast of the metropolitan area, and the NO₃^- concentration were 13.8μM on average, which was lower than the metropolitan areas, where nitrogen saturation was reported. However, O₃ and NO₃^- as a secondary product from NOx were proceeded in conjunction. Thus, it is essential to figure out the situation of environment such as O₃ and NO₃^-.