Novel imazethapyr detoxification applying advanced oxidation processes

Different degradation methods have been applied to assess the suitability of advanced oxidation process (AOPs) to promote mineralization of imazethapyr [(RS)-5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid], a widely used imidazolinone class herbicide, the persistence of which has been demonstrated in surface and ground waters destined to human uses. Independent of the oxidation process assessed, the decomposition of imazethapyr always followed a pseudo-first order kinetic. The direct UV-irradiation (UV) of the herbicide as well as its oxidation with ozone (O?), and hydrogen peroxide tied to UV-irradiation (H?O?/UV) were sufficiently slow to permit the identification of intermediate products, the formation pathway of which has been proposed. Ozonation joined to UV-irradiation (O?/UV), ozonation joined to titanium dioxide photo-catalysis (TiO?/UV+O?), sole photo-catalysis (TiO?/UV), and photo-catalysis reinforced with hydrogen peroxide-oxidation (TiO?/UV+H?O?) were characterized by a faster degradation and rapid formation of a lot of small molecules, which were quickly degraded to complete mineralization. The most effective oxidation methods were those using titanium dioxide photo-catalysis enhanced either by ozonation or hydrogen peroxide. Most of all, these last processes were useful to avoid the development of dangerous by-products.     

Bio-methane production from tomato pomace: preliminary evaluation of process intensification through ultrasound pre-treatment

Journal of Material Cycles and Waste Management - The effect of ultrasound pre-treatment (for 5, 15, and 30 min) on tomato pomace methane yield was evaluated. With respect to the control...     

Factors influencing movement probabilities of big brown bats (Eptesicus fuscus) in buildings.

We investigated movements of female big brown bats (Eptesicus fuscus) roosting in maternity colonies in buildings in Fort Collins, Colorado (USA), during the summers of 2002, 2003, and 2005. This behavior can be of public health concern where bats that may carry diseases (e.g., rabies) move among buildings occupied by people. We used passive integrated transponders (PIT tags) to mark individual bats and hoop PIT readers at emergence points to passively monitor the use of building roosts by marked adult females on a daily basis during the lactation phase of reproduction. Multi-strata models were used to examine movements among roosts in relation to ambient temperatures and ectoparasite loads. Our results suggest that high ambient temperatures influence movements. Numbers of mites (Steatonyssus occidentalis) did not appear to influence movements of female bats among building roosts. In an urban landscape, periods with unusually hot conditions are accompanied by shifting of bats to different buildings or segments of buildings, and this behavior may increase the potential for contact with people in settings where, in comparison to their more regularly used buildings, the bats may be more likely to be of public concern as nuisances or health risks.     

Dune vegetation fertilization by nesting sea turtles

Sea turtle nesting presents a potential pathway to subsidize nutrient-poor dune ecosystems, which provide the nesting habitat for sea turtles. To assess whether this positive feedback between dune plants and turtle nests exists, we measured N concentration and delta15N values in dune soils, leaves from a common dune plant (sea oats [Uniola paniculata]), and addled eggs of loggerhead (Caretta caretta) and green turtles (Chelonia mydas) across a nesting gradient (200-1050 nests/km) along a 40.5-km stretch of beach in east central Florida, USA. The delta15N levels were higher in loggerhead than green turtle eggs, denoting the higher trophic level of loggerhead turtles. Soil N concentration and delta15N values were both positively correlated to turtle nest density. Sea oat leaf tissue delta15N was also positively correlated to nest density, indicating an increased use of augmented marine-based nutrient sources. Foliar N concentration was correlated with delta15N, suggesting that increased nutrient availability from this biogenic vector may enhance the vigor of dune vegetation, promoting dune stabilization and preserving sea turtle nesting habitat.     

Movements and wintering areas of breeding age Thick-billed Murre <Emphasis Type="Italic">Uria lomvia</Emphasis> from two colonies in Nunavut,Canada

The non-breeding movements of marine birds were poorly known until recently, but this information is essential to understanding the risk to different geographical populations from events on the wintering grounds. We tracked the migration routes and wintering areas of Thick-billed Murre Uria lomvia from two breeding colonies in eastern Canada: Coats Island in northern Hudson Bay and The Minarets, Baffin Island, during the period August 2007–May 2008 using geolocation loggers. Birds from The Minarets moved south rapidly post-breeding and wintered principally off Newfoundland and southern Labrador, or between Newfoundland and southern Greenland, remaining south of 55°N until at least the spring equinox. Those from Coats Island remained in Hudson Bay until at least mid-November, after which they moved rapidly through Hudson Strait to winter in southern Davis Strait and the northern Labrador Sea, mostly north of 55°N. Many individuals stayed throughout the winter in areas of heavy ice cover. Adults from the two colonies appear to be completely segregated in winter and those from Coats Island probably did not enter the area of the winter hunt in Newfoundland. Unexpectedly, some birds from The Minarets wintered in waters beyond the continental slope and outside the distribution of pack ice, demonstrating that particular individuals can be wholly pelagic throughout the winter. Coats Island birds returned through Hudson Strait as soon as open water areas became available in spring. Their sojourn in Hudson Bay coincided very closely with the occurrence of areas with <90% ice cover. In spite of the relatively large error in positions obtained from geolocation loggers, our results demonstrated the value of these devices by uncovering a number of previously unknown aspects of Thick-billed Murre non-breeding ecology in the Northwest Atlantic. Comparison of the non-breeding ecology based on SST experienced in winter show that the winter niche is broader than hitherto assumed, demonstrating that separate populations may experience different selection in the face of climate change.     

Constancy and change in marine predator diets across a shift in oceanographic conditions in the Northern California Current

Variable ocean conditions can greatly impact prey assemblages and predator foraging in marine ecosystems. Our goal was to better understand how a change in ocean conditions influenced dietary niche overlap among a suite of midtrophic-level predators. We examined the diets of three fishes and one seabird off central Oregon during two boreal summer upwelling periods with contrasting El Niño (2010) and La Niña (2011) conditions. We found greater niche specialization during El Niño and increased niche overlap during La Niña in both the nekton and micronekton diet components, especially in the larger, more offshore predators. However, only the two smaller, more nearshore predators exhibited interannual variation in diet composition. Concurrent trawl surveys confirmed that changes in components of predator diets reflected changes in the prey community. Using multiple predators across diverse taxa and life histories provided a comprehensive understanding of food-web dynamics during changing ocean conditions.     

Spatio-temporal log-Gaussian Cox processes for modelling wildfire occurrence: the case of Catalonia, 1994–2008

Wildfires have become one of the principal environmental problems in the Mediterranean basin. While fire plays an important role in most terrestrial plant ecosystems, the potential hazard that it represents for human lives and property has led to the application of fire exclusion policies that, in the long term, have caused severe damage, mainly due to the increase of fuel loadings in forested areas, in some forest systems. The lack of an easy solution to forest fire management highlights the importance of preventive tasks. The observed spatio-temporal pattern of wildfire occurrences may be idealized as a realization of some stochastic process. In particular, we may use a space–time point pattern approach for the analysis and inference process. We studied wildfires in Catalonia, a region in the north-east of the Iberian Peninsula, and we analyzed the spatio-temporal patterns produced by those wildfire incidences by considering the influence of covariates on trends in the intensity of wildfire locations. A total of 3,166 wildfires from 1994–2008 have been recorded. We specified spatio-temporal log-Gaussian Cox process models. Models were estimated using Bayesian inference for Gaussian Markov Random Field through the integrated nested Laplace approximation algorithm. The results of our analysis have provided statistical evidence that areas closer to humans have more human induced wildfires, areas farther have more naturally occurring wildfires. We believe the methods presented in this paper may contribute to the prevention and management of those wildfires which are not random in space or time.     

Platinum in PM2.5 of the metropolitan area of Mexico City

The increase in platinum (Pt) in the airborne particulate matter with size ≤2.5 µm (PM_2.5) in urban environments may be interpreted as result of the abrasion and deterioration of automobile catalyst. Nowadays, about four million vehicles in Mexico City use catalytic converters, which means that their impact should be considered. In order to evaluate the contribution of Pt to environmental pollution of the metropolitan area of Mexico City (MAMC), airborne PM_2.5 was collected at five different sites in the urban area (NW, NE, C, SW, SE) in 2011 during April (dry-warm season), August (rainy season) and December (dry-cold season). Analytical determinations were carried out using a ICP-MS with a collision cell and kinetic energy discrimination. The analytical and instrument performance was evaluated with standard road dust reference material (BCR-723). Median Pt concentration in the analyzed particulate was is 38.4 pg m^?3 (minimal value 1 pg m^?3 maximal value 79 pg m^?3). Obtained Pt concentrations are higher than those reported for other urban areas. Spatial variation shows that SW had Pt concentration significantly higher than NW and C only. Seasonal variation shows that Pt median was higher in rainy season than in both dry seasons. A comparison of these results with previously reported data of PM₁₀ from 1991 and 2003 in the same studied area shows a worrying increase in the concentration of Pt in the air environment of MAMC.     

Results and evaluation of the first study of organochlorine contaminants (PCDDs, PCDFs, PCBs and DDTs), heavy metals and metalloids in birds from Baja California, México

Organochlorine compounds (OCs) including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p-p'-DDE), heavy metals (Pb, Cd, Zn, Cu), and arsenic were measured in house sparrows (Passer domesticus) and common ground doves (Columbina passerina) from Baja California Sur, México. Concentrations of PCDD/Fs were low, with 21 pg/g for house sparrows, and 7.7 pg/g for common ground doves. Non-ortho-PCB concentrations in house sparrow and common ground doves were 58 and 254 pg/g, respectively, and are within the highest concentrations reported in species that are in the low levels of food webs. The major differences in organochlorine levels between species were found for ortho-PCBs and DDTs. ortho-PCB levels were higher in the seedeater species, whereas DDT levels were higher in the omnivorous species. Heavy metal levels were far below those associated with negative effects.