Integrated spatial health assessment of yellow perch (Perca flavescens) populations from the St. Lawrence River (QC,Canada), part B: cellular and transcriptomic effects

Environmental Science and Pollution Research - Multi-biological level assessments have become great tools to evaluate the health of aquatic ecosystems. Using this approach, a complementary study...     

Integrated spatial health assessment of yellow perch (<Emphasis Type="Italic">Perca flavescens</Emphasis>) populations from the St. Lawrence River,Quebec, Canada) part A: physiological parameters and pathogen assessment

A multi-disciplinary approach was used to evaluate the health of yellow perch (Perca flavescens) in the St. Lawrence River (Quebec, Canada), which is experiencing a severe population decline in the downstream portion of the river. Physiological parameters, liver alterations, trace metal concentrations, parasite prevalence and abundance, stable isotope composition, and the presence/absence of the viral hemorragic septicemia virus (VHSV) were evaluated in perch collected at six sites along the river: Lake St. François, Lake St. Louis (north and south), Beauregard Island, and Lake St. Pierre (north and south). Trace metal concentrations in surface water were higher in Lake St. Louis and downstream of a major urban wastewater treatment plant discharge, indicating that this effluent was a significant source of Cu, As, Ag, Zn, and Cd. Levels of Pb in surface water exceeded thresholds for the protection of aquatic life in Lake St. Louis and were negatively correlated with body condition index in this lake. In Lake St. Pierre, Cu, Ag, and Cd bioaccumulated significantly in perch liver and lower body condition index and greater liver damage were observed compared to upstream sites. Parasite analyses indicated a higher abundance of metacercariae of the trematodes Apophallus brevis and Diplostomum spp. in Lake St. Louis, and VHSV was not detected in the liver of yellow perch for all studied sites. Overall, results suggested that the global health of yellow perch from Lake St. Pierre is lower compared to upstream studied sites, which could contribute to the documented population collapse at this site.     

Norovirus GII.Pe Genotype: Tracking a Foodborne Outbreak on a Cruise Ship Through Molecular Epidemiology,Brazil, 2014

Norovirus (NoV) is recognized as the most common cause of foodborne outbreaks. In 2014, an outbreak of acute gastroenteritis occurred on a cruise ship in Brazil, and NoV became the suspected etiology. Here we present the molecular identification of the NoV strains and the use of sequence analysis to determine modes of virus transmission. Food (cream cheese, tuna salad, grilled fish, orange mousse, and vegetables soup) and clinical samples were analyzed by ELISA, conventional RT-PCR, qRT-PCR, and sequencing. Genogroup GII NoV was identified by ELISA and conventional RT-PCR in fecal samples from 5 of 12 patients tested (41.7%), and in the orange mousse food sample by conventional RT-PCR and qRT-PCR. Two fecal GII NoV samples and the orange mousse GII NoV sample were successfully genotyped as GII.Pe (ORF 1), revealed 98.0–98.8% identities among them, and shared phylogenetically distinct cluster. Establishing the source of a NoV outbreak can be a challenging task. In this report, the molecular analysis of the partial RdRp NoV gene provided a powerful tool for genotyping (GII.Pe) and tracking of outbreak-related samples. In addition, the same fast and simple extraction methods applied to clinical samples could be successfully used for complex food matrices, and have the potential to be introduced in routine laboratories for screening foods for presence of NoV.     

Solubilization and methanogenesis of a particulate industrial waste: Impact of solids loading and temperature

Effective anaerobic treatment of particulate wastes requires solubilization and acid formation prior to methanogenesis. In this case study of a particulate waste from a corn-processing industry, the influence of solids loading in solubilization, acid formation and methanogenesis was studied under mesophilic (35°C) and thermophilic (60°C) conditions. The waste was concentrated by centrifugation to initial suspended solids concentrations (TSS_i) of 150 to 350 g/L (15% to 35%). Anaerobic batch tests were conducted for 20 days, and significant solubilization of the particulate organic matter occurred in all cases. The thermophilic systems were more effective than the mesophilic systems with respect to solubilization of particulates, volatile solids destruction, acetic acid uptake, and methane generation. Methanogenesis appreared to be a rate-limiting step at higher TSS_i values, indicated by accumulation of volatile organic acids in the batch systems. Slower rates of methane production led to identification of the limiting solids loading for both temperature regimes. The results of this study can be used to evaluate the limitations of a single stage system for anaerobic treatment of organic particulate industrial wastes.     

The role of other orientation in organizational citizenship behavior

This article draws on social exchange theory and the theory of other orientation to examine how job satisfaction and individual differences are related to organizational citizenship behavior (OCB). Previous research specifying a direct effect for individual differences on OCB has yielded disappointing results. In contrast, this study examines the moderating role of individual differences in the relationship between job satisfaction and OCB. As hypothesized, results show a weaker relationship between job satisfaction and OCB for persons who are higher in other orientation. We discuss the theoretical implications of this finding and directions for future research. Copyright © 2007 John Wiley & Sons, Ltd.     

Batch tests on mineral deposit formation due to co-mingling of leachates derived from municipal solid wastes and waste-to-energy combustion residues

Deposit formation in leachate collection systems can be problematic for landfill operations. Deposits from municipal solid waste (MSW) derived leachates are impacted by microbial activity and biofilm development, whereas leachates generated from co-disposal of MSW with combustion residues (CR) from waste-to-energy (WTE) facilities and other mineral-rich waste materials are more prone to forming dense mineral deposits dominated by calcium carbonate. In this study, leachates from laboratory lysimeters containing either WTE-CR or shredded MSW were mixed at different volumetric ratios. The mixed leachates were incubated for 5 weeks in batch tests to evaluate the potential for formation of precipitates. Although mineral precipitates have been reported to form in landfills with no co-disposal practices, in this study mineral precipitates did not form in either the WTE-CR derived leachate or the MSW derived leachate, but formed in all leachate mixtures. Mineral precipitates consisted of calcium carbonate particles, with the highest yield from a 1:1 combination of the WTE-CR derived leachate mixed with the MSW derived leachate. The introduction of gaseous carbon dioxide or air into WTE-CR derived leachate resulted in the production of particles of similar chemical composition but different morphology. Operation of landfills to prevent co-mingling of mineral-rich leachates with microbially active leachates and/or to control leachate exposure to sources of carbon dioxide may help to prevent this type of precipitate formation in leachate collection systems.