Population dynamics of the tropical cladoceran Ceriodaphnia rigaudi Richard, 1894 (Crustacea: Anomopoda). Effect of food type and temperature

The knowledge of population effects of food on tropical, filter-feeding cladocerans is scarce because a reduced number of species has been extensively studied. Ceriodaphnia rigaudi Richard 1894, a small-sized cladoceran distributed mainly in tropical and subtropical regions of the world, was studied. The aim of this study was to contribute to the knowledge of the reproductive biology of a poor-known Cladoceran; for this we assessed the effect of feeding and temperature on the reproduction and life cycle of this species. Three microalga species (Pseudokirchneriella subcapitata, Ankistrodesmus falcatus, and Chlorella vulgaris) were supplied as food each at a concentration of 12 mg l(-1) (dry weight, equivalent to 1.3 x 10(6), 0.4 x 10(6) and 1.35 x 10(6) cell m1(-1), respectively, and equivalent to 7.8 microg C ml(-1), at two temperatures (20 and 25 degrees C). We evaluated, among other responses, longevity, total progeny, survival, life expectancy at birth and fecundity. Organisms fed with the microalgae A. falcatus and P subcapitata presented both higher longevity (30.7 +/- 5.91, 26.6 +/- 3.59 days, respectively) and total progeny (45 +/- 13.80, 40.7 +/- 0.66 neonates female (-1) values than those organisms fed C. vulgaris (13.5 +/- 4.63 days and 17.6 +/- 6.19 neonates female (-1), respectively). On the other hand, temperature affected significantly the population parameters of C. rigaudi, recording maximal longevity values (56.1 +/- 9.41 days) at 20 degrees C in organisms fed A. falcatus; however, age at first reproduction and total progeny were negatively affected by this temperature: sexual maturation of the females was delayed until the age of 16 days and the number of neonates produced was smaller (9.8 +/- 3.45 with C. vulgaris; 24.7 +/- 6.01 with P subcapitata, and 35.5 +/- 8.59 neonates female(-1) with A. falcatus). The best reproductive responses for C. rigaudi in this study were obtained with A. falcatus at degrees 25 degrees C.     

Development and modelling of realistic retrofitted Nature-based Solution scenarios to reduce flood occurrence at the catchment scale

Decentralized Nature-based Solutions such as Urban Green Infrastructures (UGI) are increasingly promoted to reduce flooding in urban areas. Many studies have shown the effectiveness of flood control of UGI at a plot or neighbourhood level. Modelling approaches that extrapolate their flood reducing impact to larger catchment scales are often based on a simplistic assumption of different percentages of UGI implementation. Additionally, such approaches typically do not consider the suitable space for UGI and potential implementation constraints. This study proposes a scenario development and modelling approach for a more realistic upscaling of UGI based on empirical insights from a representative neighbourhood. The results from this study, conducted in the metropolitan area of Costa Rica, show that upscaling the full potential for UGI could significantly reduce surface runoff, peak flows, and flood volumes. In particular, the permeable pavement has the highest potential for flood reducing in public space while cisterns perform best at the property level. These results can guide the formation of policies that promote UGI.Supplementary InformationThe online version of this article (10.1007/s13280-020-01493-8) contains supplementary material, which is available to authorized users.     

Adenovirus and Norovirus Contaminants in Commercially Distributed Shellfish

Shellfish complying with European Regulations based on quantification of fecal bacterial indicators (FIB) are introduced into markets; however, information on viruses, more stable than FIB, is not available in the literature. To assess the presence of noroviruses (NoVs) GI and GII and human adenoviruses (HAdV) in domestic and imported mussels and clams (n = 151) their presence was analyzed during winter seasons (2004–2008) in north-west Spanish markets through a routine surveillance system. All samples tested negative for NoV GI and 13 % were positive for NoV GII. The role of HAdV as viral indicator was evaluated in 20 negative and 10 positive NoV GII samples showing an estimated sensitivity and specificity of HAdV to predict the presence of NoV GII of 100 and 74 % (cut-off 0.5). The levels of HAdV and NoVs and the efficiency of decontamination in shellfish depuration plants (SDP) were evaluated analyzing pre- and post-depurated mussels collected in May–June 2010 from three different SDP. There were no statistically significant differences in the prevalence and quantification of HAdV between pre- and post-depurated shellfish and between seawater entering and leaving the depuration systems. Moreover, infectious HAdV were detected in depurated mussels. These results confirm previous studies showing that current controls and depuration treatments limiting the number of FIB do not guarantee the absence of viruses in shellfish.     

How to stay together? Habitat use by three sympatric sharks in the western coast of Baja California Sur,Mexico

Environmental Science and Pollution Research - Sharks are top predators and play an important role in the regulation of marine ecosystems at lower trophic position. Mustelus californicus, Sphyrna...     

A Recycling Alternative for Expanded Polystyrene Residues Using Natural Esters

Journal of Polymers and the Environment - The objective of this research is to provide a new recycling method for one of the most consumed plastics today, since it is used for the manufacture of a...     

Comparing Contaminant Removal Costs for Aquifer Recharge with Wastewater with Water Supply Benefits

The use of waters of impaired quality has been suggested as a means to expand available water resources supply for water‐limited communities. An ongoing concern is the safety of supplies that use wastewater because of the potential for introduction of emerging contaminants such as pharmaceuticals into drinking water supplies. Prior research into contaminants of emerging concerns (CECs) have included a variety of methods, but the only consistent removal is with reverse osmosis (RO) membranes, ultraviolet light (UV), and advanced oxidation processes (AOP). However, few of these prior studies have measurable quantities of these contaminants in the influent wastewater, so determining actual removal percentages is difficult. This project was designed to evaluate the removal of CECs to verify that a 3‐log removal of common constituents was realized. Spike testing was used to compare to prior research and to evaluate whether the project costs were competitive with other forms of reuse or other water supplies. The combination of RO/UV/AOP was effective at obtaining a 3‐log removal of CECs, but the RO and UV/AOP processes alone were not capable of removing all substances. However, despite the extensive treatment, the proposed process was both competitive cost‐wise and met the water quality goals.     

A review of the contributions of Albert Einstein to Earth Sciences—in commemoration of the World Year of Physics

The World Year of Physics (2005) is an international celebration to commemorate the 100th anniversary of Einstein’s “Annus Mirabilis.” The United Nations has officially declared 2005 as the International Year of Physics. However, the impact of Einstein’s ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions to Earth Sciences. His geosciences-related letters, comments, and scientific articles are dispersed, not easily accessible, and are poorly known. The present review attempts to integrate them as a tribute to Einstein in commemoration of this centenary. These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism, and fluvial geomorphology. Regarding geodynamics, Einstein essentially supported Hapgood’s very controversial theory called Earth Crust Displacement. With respect to geological (planetary) catastrophism, it is shown how the ideas of Einstein about Velikovsky’s proposals evolved from 1946 to 1955. Finally, in relation to fluvial geodynamics, the review incorporates the elegant work in which Einstein explains the formation of meandering rivers. A general analysis of his contributions is also carried out from today’s perspective. Given the interdisciplinarity and implications of Einstein’s achievements to multiple fields of knowledge, we propose that the year 2005 serve, rather than to confine his universal figure within a specific scientific area, to broaden it for a better appreciation of this brilliant scientist in all of his dimensions.     

Sorption of As, Cd and Tl as influenced by industrial by-products applied to an acidic soil: equilibrium and kinetic experiments

In situ stabilization of toxic elements in contaminated soils by the addition of amendments is being considered as an effective technique for remediation. In this paper, we performed both kinetics and equilibrium-based sorption experiments of three toxic elements (As, Cd and Tl) in soils amended with two by-products (phosphogypsum and sugar foam, rich in gypsum and calcium carbonate, respectively) to ascertain the feasibility of their application for improving the sorption capacity of As, Cd and Tl from the soil at 25, 35 and 50 °C. Kinetic studies indicated that the sorption follows a pseudo-second-order (PSO) kinetics and the sorption is a two-step diffusion process where both film and intraparticle diffusion played important roles in the sorption mechanisms of the elements. The Langmuir isotherms applied for sorption studies showed that the estimated maximum sorption capacity of the elements in control and amended soils decreased in the order of Cd > As > Tl. Using the thermodynamic equilibrium parameters obtained at different temperatures, the thermodynamic constants of sorption (ΔG, ΔH and ΔS) were also evaluated, indicating spontaneous and endothermic nature of the process, except Tl which was exothermic. An optimal scaling procedure was undertaken to determine the relationships between the kinetic and equilibrium sorption parameters. By means of statistical analysis it was seen that these inter-parametric relationships are dependent on the element nature.     

Antibiotic resistance of Enterococcus spp. isolated from wastewater and sludge of poultry slaughterhouses

Antibiotimicrobial resistance was investigated in 537 Enterococcus spp. isolates recovered from 22 samples of crude inflow, treated effluent and sludge collected in wastewater treatment plants of eight poultry slaughterhouses of Portugal. No significant differences (P > 0.05) were found in the resistance to each antimicrobial agent with regards to the origin of the sample (inflow, sludge and effluent). Many of the isolates displayed resistance to tetracycline (85.7%), erythromycin (45.7%), nitrofurantoin (34.0%) and rifampicin (17.8%). Resistance was also observed, but to a lesser extent, to ciprofloxacin (10.2%), ampicillin (8.0%), chloramphenicol (4.6%), vancomycin (0.9%) and gentamicin (0.4%). Resistance to three or more antimicrobial classes was present in 37.1% of the isolates. Wastewater treatment resulted in viable enterococci decrease between less than 1 log and 4 log; nevertheless, more than 4.4 x 10(5) colony forming units (CFU)/100 mL were present in the outflow of the plants and thus resistant enterococci are not prevented from reaching the general environment.