Search

Improved understanding of the effects of meteorological conditions on the transmission of SARS-CoV-2, the causative agent for COVID-19 disease, is needed. Here, we estimate the relationship between air temperature, specific humidity, and ultraviolet radiation and SARS-CoV-2 transmission in 2669 U.S. counties with abundant reported cases from March 15 to December 31, 2020. Specifically, we quantify the associations of daily mean temperature, specific humidity, and ultraviolet radiation with daily estimates of the SARS-CoV-2 reproduction number (Rt) and calculate the fraction of Rt attributable to these meteorological conditions. Lower air temperature (within the 20–40 °C range), lower specific humidity, and lower ultraviolet radiation were significantly associated with increased Rt. The fraction of Rt attributable to temperature, specific humidity, and ultraviolet radiation were 3.73% (95% empirical confidence interval [eCI]: 3.66–3.76%), 9.35% (95% eCI: 9.27–9.39%), and 4.44% (95% eCI: 4.38–4.47%), respectively. In total, 17.5% of Rt was attributable to meteorological factors. The fractions attributable to meteorological factors generally were higher in northern counties than in southern counties. Our findings indicate that cold and dry weather and low levels of ultraviolet radiation are moderately associated with increased SARS-CoV-2 transmissibility, with humidity playing the largest role.

Improved understanding of the effects of meteorological conditions on the transmission of SARS-CoV-2, the causative agent for COVID-19 disease, is needed. Here, we estimate the relationship between air temperature, specific humidity, and ultraviolet radiation and SARS-CoV-2 transmission in 2669 U.S. counties with abundant reported cases from March 15 to December 31, 2020. Specifically, we quantify the associations of daily mean temperature, specific humidity, and ultraviolet radiation with daily estimates of the SARS-CoV-2 reproduction number (Rt) and calculate the fraction of Rt attributable to these meteorological conditions. Lower air temperature (within the 20–40 °C range), lower specific humidity, and lower ultraviolet radiation were significantly associated with increased Rt. The fraction of Rt attributable to temperature, specific humidity, and ultraviolet radiation were 3.73% (95% empirical confidence interval [eCI]: 3.66–3.76%), 9.35% (95% eCI: 9.27–9.39%), and 4.44% (95% eCI: 4.38–4.47%), respectively. In total, 17.5% of Rt was attributable to meteorological factors. The fractions attributable to meteorological factors generally were higher in northern counties than in southern counties. Our findings indicate that cold and dry weather and low levels of ultraviolet radiation are moderately associated with increased SARS-CoV-2 transmissibility, with humidity playing the largest role., The role of meteorological factors in SARS-COV-2 transmission is not well understood. Here, the authors use county-level data from the United States to the end of 2020 and find evidence of a moderate association between increased transmissibility and cold, dry weather and low ultraviolet radiation.

We examine the spillovers and dependencies between iron ore prices, bond yields of mechanical equipment, infrastructure construction and housing, and car industries, and steel prices by using the spillover index and copula model over the period 2011–2021. Our results show that compared with bond yields, iron ore prices are primary contributors of price spillovers and highly comparable with China's steel prices. Notably, the magnitudes of correlations and risk transmissions from bond yields of related industries to steel prices shifts over the period before the implementation of China's policy to cut overcapacity in steelmaking, after the policy implementation and before the outbreak of coronavirus, and after the outbreak of coronavirus. Because of high price spillovers from iron ore to steel prices and iron ore-steel relationship, policymakers in the steel industry should consider more supply-side policies to mitigate market risks. Meanwhile, risk-averse investors should increase the share of bonds of related industries.

We have examined the time-varying price spillovers and dependencies between iron ore, scrap steel, carbon emissions, seaborne transportation, and China's steel stock by using price spillover and copula models to cover the period 2011–2020. More specifically, the Platts, the MBIOI, and the Chinese Iron Ore spot prices (CIOPI) are analyzed and compared. Our results show that of the three iron ore price indexes, the Platts is a primary contributor of price spillover and highly comparable with China's steel stock prices. The scrap steel, seaborne transportation, and carbon emission prices incur relatively low price spillovers and moderately link with China's steel stock prices. In addition, the time-varying price spillovers and links are sensitive to economic shocks stemming from China's policy implementation to cut overcapacity in steelmaking and the spread of coronavirus. Our results may suggest that the Platts is still the benchmark spot price in determining China's steel stock prices. The results might also guide market investors to hedge the financial risks in the commodity market and help policymakers design appropriate financialization policies for the iron ore and steel markets.

An open source remote monitoring system is designed and built to address the needs of researchers to provide basic illuminated visual indication of laser operation for university research laboratories that are equipped with multiple types of high-powered lasers and have limited financial resources. The 3D printed remote monitoring system selectively monitors either the total current running through a laser or a TTL shutter signal to wirelessly indicate at the laboratory entrances that a laser is in use. Several lasers can be monitored in a single room and each room entrance can have its own wireless laser activity indicator. The wireless feature eliminates the expense of in-wall wiring for the system. An emergency shut off switch is included as an optional attachment. This article describes the design of the readily deployed open source laser monitoring system, including how it was built and tested for integration into a microscopy research laboratory.

We examine the sensitivity of China's steel price movements to iron ore, scrap steel, carbon emission allowance, and seaborne transportation prices over the period 2010–2020. More specifically, the price spillover, the dependence structure, and the spillover risk between iron ore, scrap steel, carbon emission allowance, seaborne transportation, and China's steel prices are analyzed in a multivariate framework, vine copula, and conditional risk setup. Our results demonstrate that before and after the implementation of China's policy to cut overcapacity in steelmaking, China's steel prices are mainly subject to iron ore prices. Our results have potential implications for policymakers to exploit market incentives to regulate steelmakers' investments and capacity in steelmaking.

Using Australian firm data, this study constructs an error correction model of capital stock adjustment to examine the uncertainty–investment relationship in the mining industry. As indicated, with firm features, the effect of demand uncertainty on the short run investment response to demand shocks is positive, while the effect of demand uncertainty on investment is negative. In addition, changes in exchange rate costs and Chinese ownership promote investment. More specifically, separating the sample period into before and after 2003, the estimation suggests that only after 2003 with the negative effect of Chinese GDP growth uncertainty, Chinese ownership had a positive effect on Australian mining investment. This suggests that rising Chinese demand after 2003 has a large impact on Australian mining investment.

We investigate the dependence structures between prices of crude oil, natural gas, steam coal, and iron ore, the Australian dollar, and the Chinese RMB exchange rates. Dependence structures are analyzed and compared using copula models. Our evidence shows that the increases in the commodity prices coincide with an increase in the Australian dollar and a decrease in the Chinese RMB. For the period 2010–2015, a relatively high correlation between oil prices, the Australian dollar, and the Chinese RMB was evident. For the period 2015–2018, the strength of the relationship between oil prices, the Australian dollar, and the Chinese RMB decreased. Simultaneously, the weak association between the steam coal prices and the Chinese RMB was observed, accompanied by a prominent relation between gas prices and the Chinese RMB. Our results may clarify the impact of the China's national policies to adjust its resource demand on commodity prices and help policymakers hedge the financial risks of the commodity market.

To examine the impact of the change in forward pricing mechanism on the volatility of iron ore spot prices, we model the iron ore daily price of Platts IODEX from October 7, 2008 to September 21, 2012. The identified iron ore spot price tends to be less volatile after the introduction of quarterly pricing mechanism. Our main approaches are as follows: (i) to decompose the spot price of Platts IODEX into two subsamples and relate the result of the structural break to the date of the switch in the iron ore forward pricing mechanism; (ii) to apply the EGARCH (1, 1) model to simultaneously capture the long memory and the asymmetric effect on the volatility of the iron ore spot price; and (iii) to delineate the news impact curve to further interpret the asymmetric effect.