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This brief report documents the results of a survey that measured the public’s and doctors’ perceived effectiveness of preventive behaviors against COVID-19, in Japan. Medical doctors ( n = 117) and the general public ( n = 1086) participated in our online survey. The results of the analysis of mean scores indicate that there were only slight differences in perceived effectiveness between the two groups, while the differences in distributions were remarkable. The results of Silverman’s test suggest the unimodality of doctors’ responses and multimodality of the public’s responses. Implications of the findings to combat the risk of infection are discussed.

A concise, highly stereoselective synthesis of 2,4- and 2,5-disubstituted thiazole amino acids was developed. These are important building blocks for various biologically active thiazole-containing natural peptides and their regioisomeric analogues. The fundamental reactions are diastereoselective addition of (4- or 5-bromothiazol-2-yl)lithium to N-tert-butanesulfinyl imine with subsequent Pd-catalyzed phenoxycarbonylation.

The sustainability of metal use is threatened by increasing global demand. The concept of scarcity in mining capacity is of particular relevance to the sustainability of metals; it represents an imbalance between availability and mine production and is determined by socio-economic conditions. Although socio-economic conditions vary by region or country, few studies have assessed the scarcity in mining capacity of metals on such regional scales, which fails to assess potential risks for local sustainability. Here, we propose a country-specific indicator for the assessment of scarcity in mining capacity of metals that reflects differences in national conditions. We apply our methodology to 16 representative metals for 2000, 2010 and 2017. The results demonstrate our indicator of country-specific scarcity varies by 1-3 orders of magnitude for the metals considered, depending on reserves and mine production in producing countries. Furthermore, an indicator that represents the degree of concentrated production in high-scarcity countries is introduced, which reveals the dependency on high-scarcity countries for Al, REE, Li, and Sn. For the assessment of the effects of specific demand on the potential risks of threatening local sustainability, we define the severity of mine production that represents the magnitude of the potential risks determined by both country-specific mine production and scarcity. Analysis of metal scarcity considering country-specific conditions can reveal the potential risks for local sustainability associated with metal production and support metal users to seek effective solutions to reduce the potential risks, which is not considered in existing criticality assessments.

In-use stocks of metals underpin essential services in the world's economy and drive long-term anthropogenic metal cycles. Given this fact, the global distribution patterns of metal stocks provide a fundamental basis for examining ways to satisfy the basic needs of an expanding global population within the Earth's carrying capacity. Here we show that the in-use stocks of six major metals (steel, aluminum, copper, zinc, lead and nickel) are distributed very unevenly across 231 countries and regions. According to our analysis, the highest 20% of the world's population (ordered in terms of metal stock per capita) accounts for approximately 60-75% of the world's total metal stock, while the lowest 20% accounts for only about 1%. International inequality in metal stocks has been decreasing over time due to the strong growth in developing countries, mainly those in Asia. However, our analysis shows that the continued reduction of metal stock inequality through this growth-led pathway will put heavy pressure on the environment, with a 2-3-fold increase in global metal demand by mid-21st century. These findings imply the need for alternative stock evolution patterns involving contraction and convergence, where global per capita metal stock growth stabilizes at a level below that current for developed countries.

Recycling has become increasingly important as a means to mitigate not only waste issues but also problems related to primary resource use, such as a decrease in resource availability. In order to promote and plan future recycling efficiently, detailed information on the material stock in society is important. For a detailed analysis of material stocks, quantitative information on flows of a material, such as its accumulation pathways, final destinations, and its processing forms, are required. This paper develops a model for tracking accumulation pathways of materials using input–output tables (IOTs). The main characteristics of the proposed model are as follows: (1) accumulations in sectors other than the final demand sectors (i.e., endogenous sectors) are explicitly evaluated, (2) accumulations as accompaniments to products, such as containers and packaging, are distinguished from the products, and (3) processing forms of materials are considered. The developed model is applied to analyze copper flows in Japan using the Japanese IOTs for the year 2011. The results show that accumulations of copper in endogenous sectors were not negligibly small (9.24% of the overall flow). Although accumulations of copper as accompaniments were very small, they may be larger for other materials that are largely used as containers or packaging. It was found that the destinations of copper showed different characteristics depending on the processing forms.

The future availability of mineral resources has attracted much attention; therefore, a quantitative evaluation of the potential impacts of resource use on future availability is important. Although the surplus cost model is often recommended among the existing endpoint characterization models of mineral resources, it has a shortcoming as it does not consider the changes in future primary resource use. This paper introduces a new characterization model considering future primary resource use changes, due to future changes in total demand and secondary resource use. Using material flow analysis, this study estimated time-series primary resource use for iron and copper for five shared socioeconomic pathways (SSPs) and a constant total demand scenario. New characterization factors, i.e., demand change-based surplus costs (DCSC), are calculated for each resource. In all of the SSPs, the calculated DCSCs are larger than the conventional surplus costs (SC) for both iron and copper. The DCSC, relative to the SC of copper, is larger than that of iron for all of the SSPs, which suggests that the potential impacts of copper use, relative to iron, will be underestimated, unless future primary resource use changes are considered. In calculating DCSC for other resources, it is important to choose an appropriate approach for forecasting future total demands.