The viral phoenix: enhanced infectivity and immunity evasion of SARS-CoV-2 variants

SARS-CoV-2 pandemic continues with emergence of new variants of concerns. These variants are fueling the third and fourth waves of pandemic across many nations. Here we describe the new emerging variants of SARS-CoV-2 and why they have enhanced infectivity and possess the ability to evade immunity.

     

Pesticide resurrection

Environmental Chemistry Letters -     

Process enhancing strategies for the reduction of Cr(VI) to Cr(III) via photocatalytic pathway

Environmental Science and Pollution Research - This discourse aimed at providing insight into the strategies that can be adopted to boost the process of photoreduction of Cr(VI) to Cr(III). Cr(VI)...     

水权交易机制对农业用水效率的影响及效应分析

中国水权交易市场尚处于发展初期,其农业节水的实际效果有待检验。在测算2011—2020年中国30个省（市、自治区）农业用水效率的基础上,基于准自然实验的思路,运用空间双重差分法实证评估了水权交易机制对农业用水效率的定量影响,并进一步从理论和实证角度探究了水权交易机制对农业节水的影响机制与具体作用路径。研究发现：水权交易机制对农业用水效率具有显著的提升作用,这一结论在经过一系列稳健性检验后依然成立,且水权交易机制的政策效应具有明显的地区异质性,中部地区的政策效应最大,东部地区次之,西部地区最小;水权交易机制不仅有助于试点省份农业节水目标的实现,而且能够通过政策溢出效应同时提升周边地区的农业用水效率;技术创新和要素流动是水权交易机制发挥农业节水效应的主要路径,且一三产业之间的水要素流动对农业用水效率的促进作用更大。     

Environmental surveillance of SARS-CoV-2 RNA in wastewater systems and related environments in Wuhan: April to May of 2020

Wastewater-based epidemiology(WBE) has emerged as an effective environmental surveillance tool in monitoring fecal-oral pathogen infections within a community. Congruently, SARS-Co V-2, the etiologic agent of COVID-19, has been demonstrated to infect the gastrointestinal tissues, and be shed in feces. In the present study, SARS-Co V-2 RNA was concentrated from wastewater, sludge, surface water, ground water, sediment, and soil samples of municipal and hospital wastewater systems and related envi...     

A balancing act: Optimizing free chlorine contact time to minimize iodo-DBPs, NDMA, and regulated DBPs in chloraminated drinking water

Many drinking water treatment plants in the U.S. have switched from chlorination to chloramination to lower levels of regulated trihalomethane (THM) and haloacetic acid (HAA) disinfection byproducts (DBPs) in drinking water and meet the current regulations. However, chloramination can also produce other highly toxic/carcinogenic, unregulated DBPs: iodo-acids, iodo-THMs, and N-nitrosodimethylamine (NDMA). In practice, chloramines are generated by the addition of chlorine with ammonia, and plants use varying amounts of free chlorine contact time prior to ammonia addition to effectively kill pathogens and meet DBP regulations. However, iodo-DBPs and nitrosamines are generally not considered in this balancing of free chlorine contact time. The goal of our work was to determine whether an optimal free chlorine contact time could be established in which iodo-DBPs and NDMA could be minimized, while keeping regulated THMs and HAAs below their regulatory limits. The effect of free chlorine contact time was evaluated for the formation of six iodo-trihalomethanes (iodo-THMs), six iodo-acids, and NDMA during the chloramination of drinking water. Ten different free chlorine contact times were examined for two source waters with different dissolved organic carbon (DOC) and bromide/iodide. For the low DOC water at pH 7 and 8, an optimized free chlorine contact time of up to 1 h could control regulated THMs and HAAs, as well as iodo-DBPs and NDMA. For the high DOC water, a free chlorine contact time of 5 min could control iodo-DBPs and NDMA at both pHs, but the regulated DBPs could exceed the regulations at pH 7.     

Antioxidant contents of bell pepper and melon fruits grown in soil amended with recycled waste

Composting and land application of municipal sewage sludge (SS) and yard waste (YW) compost are increasingly popular ways for using organic waste as a source of organic matter, while decreasing the amount of waste being diverted into landfills. Researchers have largely ignored the effect of SS and SS mixed with YW (SS+YW) compost on the antioxidant contents of vegetables grown under this practice. Accordingly, the main objective of this investigation was to monitor the impact of SS and SS+YW on the nutritional composition of pepper and melon fruits at harvest. Total phenols and ascorbic acid contents of pepper and melons (determined by the Folin-Ciocalteau and the dichlorophenol–indophenol methods, respectively) were greater in pepper than melon fruits. Soil amended with SS or SS+YW significantly elevated the concentrations of ascorbic acid and total phenols in melon fruits compared to no-mulch native soil. The application of SS did not modify the concentration of β-carotene in melon fruits at three harvests. Regardless of soil treatments, ascorbic acid and total phenols concentrations were greater in melon fruits collected at the first harvest compared to harvest three. Pepper fruits collected at harvest three contained the greatest concentrations of ascorbic acid and total phenols; whereas, pepper fruits collected at the second harvest contained the greatest concentrations of soluble sugars.     

Total Factor Productivity Change in the New England Groundfish Fishery: 1964–1993

We develop estimates of total factor productivity (TFP) change in the New England groundfish fishery from 1964 to 1993, using a procedure similar to Squires' (1992, Rand J. Econom.23(2), 221–236) method, which extends standard TFP measurement by including the effect of fluctuations in stock abundance. The results indicate that TFP increased on average by 4.4% per year from 1964 to 1993. A higher average rate of increase occurred between 1964 and 1982, possibly due to new technologies (e.g., fishfinders). TFP declined at 0.33% annually from 1983 to 1993 due to stringent output and effort control measures.