Search

The highly contagious nature of SARS-CoV-2 has led to several studies on the transmission of the virus. A little studied potential fomite of great concern in the community is currency, which has been shown to harbor microbial pathogens in several studies. Since the onset of the COVID-19 pandemic, many businesses in the United States have limited the use of banknotes in favor of credit cards. However, SARS-CoV-2 has shown greater stability on plastic in several studies. Herein, the stability of SARS-CoV-2 at room temperature on banknotes, money cards and coins was investigated. In vitro studies with live virus suggested SARS-CoV-2 was highly unstable on banknotes, showing an initial rapid reduction in viable virus and no viral detection by 24 hours. In contrast, SARS-CoV-2 displayed increased stability on money cards with live virus detected after 48 hours. Environmental swabbing of currency and money cards on and near the campus of Brigham Young University supported these results, with no detection of SARS-CoV-2 RNA on banknotes, and a low level on money cards. However, no viable virus was detected on either. These preliminary results suggest that the use of money cards over banknotes in order to slow the spread of this virus may be ill-advised. These findings should be investigated further through larger environmental studies involving more locations.

The present work was focused to design a cheap, rapid, portable and easy to use filter paper based assay for the qualitative and quantitate analysis of acetone. Sodium alginate gel was loaded with the acetone specific optical signal probe, and subsequently coated onto filter paper surface to design portable colorimetric assays for acetone monitoring. The color of the paper sensor strip was observed to change from dark yellow to light yellowish in the presence of varying concentrations of acetone. Three different color analyzing models including RGB, HSV, and LAB were employed to probe the output optical signal, and their performance was compared in terms of better interpretation of the generated signal. The LAB model was found to provide better analytical figures of merit with a linear response for the acetone concentration ranging from 2.5 to 1500 ppm, and a limit of detection of 0.5 ppm. Furthermore, the specificity of the designed filter paper based sensor was demonstrated against different common interfering compounds. The results demonstrated the potential of our proposed filter paper based sensor as a novel tool for the analysis of acetone.

Theoretical and experimental research studies have shown that ecosystems governed by non-transitive competition networks tend to maintain high levels of biodiversity. The theoretical body of work, however, has mainly focused on competition networks in which the outcomes of competition events are predetermined and hence deterministic, and where all species are identical up to their competitive relationships, an assumption that may limit the applicability of theoretical results to real-life situations. In this paper, we aim to probe the robustness of the link between biodiversity and non-transitive competition by introducing a three-dimensional winning probability parameter space, making the outcomes of competition events in a three-species in silico ecosystem uncertain. While two degenerate points in this parameter space have been the subject of previous studies, we investigate the remaining settings, which equip the species with distinct competitive abilities. We find that the impact of this modification depends on the spatial dimension of the system. When the system is well mixed, it collapses to monoculture, as is also the case in the non-transitive deterministic setting. In one dimension, chaotic patterns emerge, which tend to maintain biodiversity, and a power law relates the time that species manage to coexist to the degree of uncertainty regarding competition event outcomes. In two dimensions, the formation of spiral wave patterns ensures that biodiversity is maintained for moderate degrees of uncertainty, while considerable deviations from the non-transitive deterministic setting have strong negative effects on species coexistence. It can hence be concluded that non-transitive competition can still produce coexistence when the assumption of deterministic competition is abandoned. When the system collapses to monoculture, one observes a "survival of the strongest" law, as the species that has the highest probability of defeating its competitors has the best odds to become the sole survivor.

The pulp and paper industry around the world has been growing rapidly. As a result there has been a huge demand for pulp and paper making raw material. Recent years have seen a spurt in use of nonwood fibers being used as a raw material for this purpose. Although some of the nonwood fibers used for papermaking are used because of their fine paper making qualities, majority of nonwood fibers is used to overcome the shortage of wood fibers. As a result their use is more widespread in countries with shortage of wood. The use of nonwood fibers in pulp and paper industry is fraught with problems. Right from supply of raw material to the properties of finished paper, majority of nonwood raw material has proven to be economically inferior to wood. But over the last few years, technological breakthrough in almost all the fields of papermaking have made nonwood more competitive with wood as a raw material for papermaking. Although till recently, use of nonwood fibers for pulp and paper making was concentrated in countries with limited wood supply, it is now showing an increasing trend even in countries with adequate wood supply due to environmental considerations. With time this trend can be expected to grow further and it can be safely said that the future of nonwood plant fibers as pulping and papermaking raw material looks bright. Master of Forestry

The objective of this study was to analyze the behavior of Brazilian paper companies in the international market. The analysis was based on the New Empirical Industrial Organization, based on Bresnahan's model (1982) to measure the conduct parameter in the industry. Two-Stage Least Squares (2SLS) method was used for the simultaneous equations estimative. From the results, it cannot be stated that the Brazilian companies behave as a monopolist or as a company in perfect competition in the international market. The parameter of 0.22 in the industry conduct indicated that the market is an oligopoly, intermediary to both extreme behaviors. RESUMO Neste trabalho, buscou-se analisar o comportamento das empresas brasileiras de papel no mercado mundial. A análise foi baseada na Nova Organização Industrial Empírica, conforme modelo proposto por Bresnahan (1982), para mensuração do parâmetro de conduta na indústria. Utilizou-se o método de Mínimos Quadrados em Dois Estágios (MQ2E) na estimativa das equações simultâneas. Pelos resultados, não se pode afirmar que as firmas brasileiras no mercado internacional apresentam comportamento de monopólio ou concorrência perfeita. O parâmetro de 0,22 de conduta da indústria indicou que o mercado é um oligopólio, intermediário nos dois extremos de conduta.