Comparative Virucidal Efficacy of Seven Disinfectants Against Murine Norovirus and Feline Calicivirus,Surrogates of Human Norovirus

Human noroviruses (HuNoV) are the leading cause of acute non-bacterial gastroenteritis in humans and can be transmitted either by person-to-person contact or by consumption of contaminated food. A knowledge of an efficient disinfection for both hands and food-contact surfaces is helpful for the food sector and provides precious information for public health. The aim of this study was to evaluate the effect of seven disinfectants belonging to different groups of biocides (alcohol, halogen, oxidizing agents, quaternary ammonium compounds, aldehyde and biguanide) on infectious viral titre and on genomic copy number. Due to the absence of a cell culture system for HuNoV, two HuNoV surrogates, such as murine norovirus and feline calicivirus, were used and the tests were performed in suspension, on gloves and on stainless steel discs. When, as criteria of efficacy, a log reduction >3 of the infectious viral titre on both surrogates and in the three tests is used, the most efficacious disinfectants in this study appear to be biocidal products B, C and D, representing the halogens, the oxidizing agents group and a mix of QAC, alcohol and aldehyde, respectively. In addition, these three disinfectants also elicited a significant effect on genomic copy number for both surrogate viruses and in all three tests. The results of this study demonstrate that a halogen compound, oxidizing agents and a mix of QAC, alcohol and aldehyde are advisable for HuNoV disinfection of either potentially contaminated surfaces or materials in contact with foodstuffs.     

The use of regulatory taxation as a policy instrument for sustainability transitions: old wine in new bottles or unexplored potential?

The burgeoning literature on sustainable transitions links persistent environmental problems to the functioning of socio-technical systems. Conventional policy instruments, such as environmental taxation, are often rejected by transition scholars but in-depth studies on their potential are scarce. This paper explores the potential of the instrument of environmental taxation for influencing sustainability transitions. The multi-level perspective and the multi-phase perspective from transition thinking and the social practices approach are combined with the environmental economics theories of Pigou and Coase. Our analysis shows that the highest impact of regulatory taxation will be realised at the end of the take-off phase and in the acceleration phase of a transition. Although important barriers exist and many conditions apply, regulatory environmental taxation, especially as part of a smart policy mix, has more potential for contributing to sustainability transitions than hitherto assumed.     

THE LEGAL‐INSTITUTIONAL ANALYSIS MODEL AND WATER POLICYMAKING IN A BI‐NATIONAL SETTING1

ABSTRACT: This paper reports the use of a water negotiation model, the Legal‐Institutional Analysis Model (LIAM), in the bi‐national setting of the U.S. and Mexico in the Paso del Norte region. The following study discusses the results of developing baseline data where interstate, international, and cultural factors, as well as a long history of conflict, impact on negotiations and the extent to which the LIAM is a valuable tool for analyzing behavior among institutional actors in such a setting. The findings suggest that most water policy actors in the region prefer brokered solutions as defined within the LIAM framework.     

Modeling leaf dispersal in mixed hardwood forests using a ballistic approach

In mixed-species stands, modeling leaf litter dispersal is important to predict the physical and chemical characteristics of the forest floor, which plays a major role in nutrient cycling and in plant population dynamics. In this study, a spatially explicit model of leaf litterfall was developed and compared with two other models. These three models were calibrated for a mixed forest of oak and beech using litterfall data from mapped forest plots. All models assumed that an allometric equation described individual leaf litter production, but they strongly differed in the modeling of the probability density of leaf shedding with distance from source trees. Two models used a negative exponential function to account for leaf dispersal with distance, and this function was allowed to vary according to wind direction in one of them. In contrast, our approach was based on a simple ballistic equation considering release height, wind speed, wind direction, and leaf fall velocity; the distributions of wind speeds and wind directions were modeled according to a Weibull and a Von Mises distribution, respectively. Using an independent validation data set, all three models provided predictions well correlated to measurements (r > 0.83); however, the two models with a direction-dependent component were slightly more accurate. In addition, parameter estimates of the ballistic model were in close agreement with a foliar litter production equation derived from the literature for beech and with wind characteristics measured during leaf litterfall for both species. Because of its mechanistic background, such a spatially explicit model might be incorporated as a litterfall module in larger models (nutrient cycling, plant population dynamics) or used to determine the manner in which patch size in mixed-species stands influences litter mixture.     

Products of laccase catalyzed reaction of 1-hydroxypyrene

The formation of residues in soils and sediments which are not readily extractable is an important fate for hydrophobic organic contaminants. Reaction of 1-hydroxypyrene, a known fungal and terrestrial invertebrate metabolite and photo-oxidation product of pyrene, with a commercially prepared laccase (an oxidoreductive enzyme) in solution provides a test system to study the fate of residues in nature. The reaction of dissolved 1-hydroxypyrene with laccase produced a distinct color change and caused a precipitate to form. At least six products were shown by HPLC analysis with photodiode array detection. The most prominent peak was composed of 1,6- and 1,8-pyrene-dione as confirmed by proton NMR analysis. LC/MS data on remaining peaks indicate that radical coupling produces acetonitrile soluble dimers and at least one trimer. Proposed structures consistent with MS and photodiode array data indicate that pyrene subunits are linked predominantly by ether bonds. Additional products, insoluble in acetonitrile, were also formed. The formation of complex products in vitro, indicates that the same mechanisms could produce bound residues in soil.     

The impact of a natural disaster on altruistic behaviour and crime

Institutional altruism in the form of a public‐sector intervention and support for victims and social altruism generated by mutual aid and solidarity among citizens constitute a coming together in a crisis. This coming together and mutual support precipitate a decrease in crime rates during such an event. This paper presents an analysis of daily fluctuations in crime during the prolonged ice storms in Quebec, Canada, in January 1998 that provoked an electrical blackout. Of particular interest are the principal crisis‐related influences on daily crime patterns. A first series of analyses examines the impact of altruistic public‐sector mobilisation on crime. A significant decline in property crime rates was noticed when cheques were distributed to crisis victims in financial need in Montérégie, and hence they were attributable to public intervention (institutional altruism). Moreover, the rate of social altruism (financial donations), which was more substantial in adjoining rather than distant regions, was inversely proportional to crime rates.     

INDEX OF LAKE BASIN LAND USE FOR LAND USE PLANNING PURPOSES1

ABSTRACT: In order to plan for land use in a lake basin to maintain or improve lake water quality, municipal planners need a method of evaluating lakeshore and watershed land use that is technically sound, objective, reasonably quick, and cheap enough to be incorporated into their time and dollar budgets. Such a system is presented. It consists of measuring and rating four lakeshore land use characteristics (type of sewage disposal system, lot size, road proximity, and intensity of public use areas), and three upland watershed land use characteristics (intensity of development, forest cover, and agriculture and open space). These seven characteristics are measured, rated, and then combined to provide a two-digit index number. This number, when compared with the indexes of other lakes in the region and interpreted with assistance from officials of the State Health and Water Resources Department, indicates on a relative basis the degree to which various land uses are contributing to accelerated, cultural eutrophication. Interpretation of the index suggests land use controls necessary to improve lake water. It supplements, and should be used with, an index of lake vulnerability to accelerated eutrophication and a comparative measure of present water quality.     

Vapor intrusion mitigation challenges posed by a classic urban setting

AECOM's Environmental Remediation Services Group, under a Pennsylvania Department of Environmental Protection (PADEP) remediation contract, was tasked with assessing potential vapor intrusion risks and mitigating identified risks at an active commercial property affected by a former adjacent laundry and dry cleaning operation. The former dry cleaning operation was positioned in the center of row‐buildings containing various commercial businesses. The neighboring active commercial property is an antiquated building that operates as a coffee shop. The coffee shop building contains a service area, a kitchen, and a rear conference room on the first floor, a storage area on the second floor, and a partial basement. The basement has been observed to periodically flood. Adjacent to the coffee shop building is an operating hair and nail salon that formerly functioned as one of the dry cleaning operations buildings with known soil, groundwater, and soil gas impacts. Due to the disposition of the coffee shop building, a methodical approach was implemented to characterize the potential vapor intrusion risk and included a diagnostic building inspection that identified required management of basement apertures and abatement of periodic flooding prior to vapor intrusion mitigation system design and installation.     

Metal immobilization by sludge-derived biochar: roles of mineral oxides and carbonized organic compartment

Pyrolyzing sludge into biochar is a potentially promising recycling/disposal solution for municipal wastewater sludge, and the sludge-derived biochar (SDBC) presents an excellent sorbent for metal immobilization. As SDBC is composed of both mineral oxides and carbonized organic compartment, this study therefore compared the sorption behaviour of Pb and Zn on SDBC to those of individual and mixture of activated carbon (AC) and amorphous aluminium oxide (Al₂O₃). Batch experiments were conducted at 25 and 45 °C, and the metal-loaded sorbents were artificially aged in the atmosphere for 1–60 days followed by additional sorption experiments. The Pb sorption was generally higher than Zn sorption, and the co-presence of Pb reduced Zn sorption on each studied sorbent. Higher sorption capacities were observed at 45 °C than 25 °C for SDBC and AC, while the opposite was shown for Al₂O₃, indicating the significance of temperature-dependent diffusion processes in SDBC and AC. Nevertheless, metal sorption was more selective on Al₂O₃ that showed a greater affinity towards Pb over Zn under competition, correlating with the reducible fraction of sequential extraction. Furthermore, significant amounts of Pb and Zn were additionally sorbed on SDBC following 30-day ageing. The X-ray diffraction revealed the formation of metal-phosphate precipitates, while the X-ray photoelectron spectroscopy showed a larger quantity of metal–oxygen bonding after 30-day ageing of metal-loaded SDBC. The results may imply favourable long-term transformation and additional sorption capacity of SDBC. In conclusion, SDBC resembles the sorption characteristics of both organic and mineral sorbents in different aspects, presenting an appropriate material for metal immobilization during soil amendment.