Does Deep Learning Enhance the Estimation for Spatially Explicit Built Environment Stocks through Nighttime Light Data Set? Evidence from Japanese Metropolitans.

Built environment stocks have attracted much attention in recent decades because of their role in material and energy flows and environmental impacts. Spatially refined estimation of built environment stocks benefits city management, for example, in urban mining and resource circularity strategy making. Nighttime light (NTL) data sets are widely used and are regarded as high-resolution products in large-scale building stock research. However, some of their limitations, especially blooming/saturation effects, have hampered performance in estimating building stocks. In this study, we experimentally proposed and trained a convolution neural network (CNN)-based building stock estimation (CBuiSE) model and applied it to major Japanese metropolitan areas to estimate building stocks using NTL data. The results show that the CBuiSE model is capable of estimating building stocks at a relatively high resolution (approximately 830 m) and reflecting spatial distribution patterns, although the accuracy needs to be further improved to enhance the model performance. In addition, the CBuiSE model can effectively mitigate the overestimation of building stocks arising from the blooming effect of NTL. This study highlights the potential of NTL to provide a new research direction and serve as a cornerstone for future anthropogenic stock studies in the fields of sustainability and industrial ecology.

The solar exposure time required for vitamin D3 synthesis in the human body estimated by numerical simulation and observation in Japan.

Although the importance of solar radiation for vitamin D3 synthesis in the human body is well known, the solar exposure time required to prevent vitamin D deficiency has not been determined in Japan. This study attempted to identify the time of solar exposure required for vitamin D3 synthesis in the body by season, time of day, and geographic location (Sapporo, Tsukuba, and Naha) using both numerical simulations and observations. According to the numerical simulation for Tsukuba at noon in July under a cloudless sky, 3.5 min of solar exposure are required to produce 5.5 µg vitamin D3 per 600 cm2 skin corresponding to the area of a face and the back of a pair of hands without ingestion from foods. In contrast, it took 76.4 min to produce the same quantity of vitamin D3 at Sapporo in December, at noon under a cloudless sky. The necessary exposure time varied considerably with the time of the day. For Tsukuba at noon in December, 22.4 min were required, but 106.0 min were required at 09:00 and 271.3 min were required at 15:00 for the same meteorological conditions. Naha receives high levels of ultraviolet radiation allowing vitamin D3 synthesis almost throughout the year.

Nephrogenic diabetes insipidus associated with hemochromatosis.

Although hemochromatosis is one of the most common genetic disorders in humans, the clinical information on iron-induced renal impairment is limited. We describe the clinical features of nephrogenic diabetes insipidus (NDI) observed in a case of hemochromatosis. A 57-year-old diabetic man was admitted to the hospital with a 6-month history of persistent polyuria, which had been sustained after glycemic optimization with insulin therapy and resulted in hepatic coma. Despite sufficient basal excretion of arginine vasopressin, impaired urinary concentrating capacity was observed, which could not be corrected by supraphysiologic doses of exogenous arginine vasopressin. Histochemical investigations showed widely distributed iron deposition in hepatocytes and moderately increased iron deposits in the tubular epithelium of distal urinary tubules and collecting ducts, suggesting that iron deposition resulting from hemochromatosis leads to NDI. This may be the first case report of NDI associated with hemochromatosis in humans. More attention should be paid to latent NDI as another complication of hemochromatosis.