Detection,Quantification, and Microbial Risk Assessment of Group A Rotavirus in Rivers from Uruguay

Food and Environmental Virology - The aim of this study was to detect, quantify, and assess the risk of infection and illness for Group A Rotavirus (RVA) in the watersheds of the Santa Lucia and...     

Response of bioaerosol cells to photocatalytic inactivation with ZnO and TiO2 impregnated onto Perlite and Poraver carriers

•ZnO/Perlite inactivated 72% of bioaerosols in continuous gas phase. •TiO₂ triggered the highest level of cytotoxicity with 95% dead cells onto Poraver. •Inactivation mechanism occurred by membrane damage, morphological changes and lysis. •ZnO/Poraver showed null inactivation of bioaerosols. •Catalysts losses at the outlet of the photoreactor for all systems were negligible. Bioaerosols are airborne microorganisms that cause infectious sickness, respiratory and chronic health issues. They have become a latent threat, particularly in indoor environment. Photocatalysis is a promising process to inactivate completely bioaerosols from air. However, in systems treating a continuous air flow, catalysts can be partially lost in the gaseous effluent. To avoid such phenomenon, supporting materials can be used to fix catalysts. In the present work, four photocatalytic systems using Perlite or Poraver glass beads impregnated with ZnO or TiO₂ were tested. The inactivation mechanism of bioaerosols and the cytotoxic effect of the catalysts to bioaerosols were studied. The plug flow photocatalytic reactor treated a bioaerosol flow of 460×1 0⁶ cells/m³_air with a residence time of 5.7 s. Flow Cytometry (FC) was used to quantify and characterize bioaerosols in terms of dead, injured and live cells. The most efficient system was ZnO/Perlite with 72% inactivation of bioaerosols, maintaining such inactivation during 7.5 h due to the higher water retention capacity of Perlite (2.8 mL/g_Perlite) in comparison with Poraver (1.5 mL/g_Perlite). However, a global balance showed that TiO₂/Poraver system triggered the highest level of cytotoxicity to bioaerosols retained on the support after 96 h with 95% of dead cells. SEM and FC analyses showed that the mechanism of inactivation with ZnO was based on membrane damage, morphological cell changes and cell lysis; whereas only membrane damage and cell lysis were involved with TiO₂. Overall, results highlighted that photocatalytic technologies can completely inactivate bioaerosols in indoor environments.     

Differential livelihood adaptation to social-ecological change in coastal Bangladesh

Regional Environmental Change - Social-ecological changes, brought about by the rapid growth of the aquaculture industry and the increased occurrence of climatic stressors, have significantly...     

Pesticide and agro-ecological transition: assessing the environmental and human impacts of pesticides and limiting their use

Environmental Science and Pollution Research -     

Coping with the ‘Indian summer’: unique nesting cycle and nest architecture of the paper wasp,Polistes wattii

The Science of Nature - Leaf-cutting ants are highly successful herbivores in the Neotropics. They forage large amounts of fresh plant material to nourish a symbiotic fungus that sustains the...     

Porites and the Phoenix effect: unprecedented recovery after a mass coral bleaching event at Rangiroa Atoll,French Polynesia

The 1997/1998 El Niño Southern Oscillation (ENSO) was the most severe coral bleaching event in recent history, resulting in the loss of 16 % of the world’s coral reefs. Mortality was particularly severe in French Polynesia, where unprecedented mortality of massive Porites was observed in lagoonal sites of Rangiroa Atoll. To assess the recovery of massive Porites 15 years later, we resurveyed the size structure and extent of partial mortality of massive Porites at Tivaru (Rangiroa). Surveys revealed an abundance of massive Porites colonies rising from the shallow lagoonal floor. Colony width averaged 2.65 m, reaching a maximum of 7.1 m (estimated age of ~391 ± 107 years old). The relative cover of recently dead skeleton within quadrats declined from 42.8 % in 1998 to zero in 2013, yet the relative cover of old dead skeleton increased only marginally from 22.1 % in 1998 to 26.1 % in 2013. At a colony level, the proportion of Porites dominated by living tissue increased from 34.9 % in 1998 to 73.9 % in 2013, indicating rapid recovery of recent dead skeleton to living tissue rather than transitioning to old dead skeleton. Such rapid post-bleaching recovery is unprecedented in massive Porites and resulted from remarkable self-regeneration termed the ‘Phoenix effect’, whereby remnant cryptic patches of tissue that survived the 1997/1998 ENSO event regenerated and rapidly overgrew adjacent dead skeleton. Contrary to our earlier predictions, not only are large massive Porites relatively resistant to stress, they appear to have a remarkable capacity for recovery even after severe partial mortality.     

Intertype mark correlation function: A new tool for the analysis of species interactions

The spatial pattern of the different species in complex ecosystems reflects the underlying ecological processes. In this paper a second order moment function is proposed and tested to analyse the spatial distribution of a mark, which could be a tree characteristic such as diameter or height, between two different types of points, which could be two different tree species. The proposed function was a conditional density function based on the intertype K_rs(d) function, incorporating as test function the correlation of the marks between pairs composed of points of different types. The results obtained in simulated and real plots prove that the function is capable of revealing the scale at which spatial correlation of the mark between two types of points exists. The proposed function allows the spatial association between individuals of different species at different life stages to be identified. This analysis may reveal information on species ecology and interspecific interactions in forest ecosystems.     

Human exposure to dioxins through diet in Italy

We have measured the content of polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans (together defined as “dioxins”) in 269 samples of food of animal origin collected through the regional veterinary services, covering the national territory. Quantification of the dioxins was accomplished by isotope dilution method, and toxic equivalents (TEQ) were calculated. The average daily food intake was obtained from two main sources: national data collected by the National Institute of Nutrition, and data from an ongoing cohort study on diet and cancer including 40, 000 Italian subjects.

The mean value of dioxins measured in food of animal origin was 0.144 ± 0.266 pg-TEQ/g (range: 0.003–1.655 pg-TEQ/g). Fish was the item with the highest content. The estimated intake of dioxins with main food items of animal origin is presented. The major contribution to dioxins intake with food comes from cow milk and fish consumption. These results are in agreement with what observed in studies conducted in other countries, such as Germany, Finland, Japan, Spain, and are below the limits set by the European legislation.