Recycled lightweight concrete made from footwear industry waste and CDW

In this paper two types of recycled aggregate, originated from construction and demolition waste (CDW) and ethylene vinyl acetate (EVA) waste, were used in the production of concrete. The EVA waste results from cutting off the EVA expanded sheets used to produce insoles and innersoles of shoes in the footwear industry. The goal of this study was to evaluate the influence of the use of these recycled aggregates as replacements of the natural coarse aggregate, upon density, compressive strength, tensile splitting strength and flexural behavior of recycled concrete. The experimental program was developed with three w/c ratios: 0.49, 0.63 and 0.82. Fifteen mixtures were produced with different aggregate substitution rates (0%, 50% EVA, 50% CDW, 25% CDW–25% EVA and 50% CDW–50% EVA), by volume. The results showed that it is possible to use the EVA waste and CDW to produce lightweight concrete having semi-structural properties.     

In vitro Methylation of Arsenite in Flemish giant rabbit Cytosol

The formation of ⁷⁴As‐monomethyIarsonic acid and ⁷⁴As‐dimethylarsinic acid from carrier‐free radiolabelled ⁷⁴As‐arsenite was evaluated in an assay mixture containing 17.6% liver cytosol from the Flemish Giant rabbit. The optimal incubation temperature and pH were respectively, 39°C and 7.6. After a 2h incubation about 90% of ⁷⁴As was protein bound. Protein bound ⁷⁴As was released by hot 2 M HNO₃ (1 min, 110°C). The treatment did not destroy methylated As‐species. Up to 70% of the carrier‐free ⁷⁴As‐arsenite was methylated. Liver cytosol was stored, without loss of activity, in liquid nitrogen in the presence of 2 mM glutathione. The optimal s‐adenosyl‐methionine concentration was 1.7mM. Formation of ⁷⁴As‐monomethylarsonic acid and ⁷⁴As‐dimethylarsinic acid increased up to a glutathione concentration of respectively 10 and 20 mM. Methylation also went through in the presence of other reducing agents and proved to be ATP dependent.     

Timing matters when assessing dominance and chemical signatures in the paper wasp Polistes dominulus

A recent study (Izzo et al., Behav Ecol Sociobiol 64: 857–864, 2010) reported that cuticular hydrocarbons (CHCs) correlate with fertility, not dominance, in the paper wasp Polistes dominulus thus contradicting the results of recent investigations which concluded that social dominance is the main determinant for CHC signatures in this species. We suggest here that different forms of dominance in the pre-nesting and post-nesting phases caused the apparently contradictory results. Thus the assumption that dominance behaviour in the pre-nesting stage is synonymous with dominance after colony foundation is incorrect. We provide standardised definitions for forms of “dominance” observed in the P. dominulus life cycle to avoid apparent discrepancies in the future among studies dealing with the same topics in different annual stages.     

Assessment of anthropogenic sources of water pollution using multivariate statistical techniques: a case study of the Alqueva’s reservoir, Portugal

Multivariate statistical techniques were applied to evaluate spatial/temporal variations, and to interpret water quality data set obtained at Alqueva reservoir (south of Portugal). The water quality was monitored at nine different sites, along the water line, over a period of 18 months (from January 2006 to May 2007) using 26 water quality parameters. The cluster analysis allowed the formation of five different similarity groups between sampling sites, reflecting differences on the water quality at different locations of the Alqueva reservoir system. The PCA/FA identified six varifactors, which were responsible for 64% of total variance in water quality data set. The principal parameters, which explained the variability of quality water, were total phosphorus, oxidability, iron, parameters that at high concentrations indicate pollution from anthropogenic sources, and herbicides indicative of an intensive agricultural activity. The spatial analysis showed that the water quality was worse in the north of the reservoir.     

Assessing supercritical fluid extraction for the analysis of fipronil,kresoxim-methyl,acrinathrin, and pyridaben residues in melon

An analytical method, using supercritical fluid extraction (SFE), was assessed for residue analysis of the insecticides fipronil, acrinathrin and pyridaben and the fungicide kresoxim-methyl in melons. Extraction conditions were optimized on glass beads, as inert material, evaluating different pressures, temperatures, and CO₂ volumes. Also, the extractability of pesticides from hydromatrix and anhydrous magnesium sulfate was evaluated. Both adsorbents were evaluated for the preparation of SFE-spiked melon samples. Extractions of fortified samples were done using 20 mL of CO₂, 300 atm, and 50°C. Different extraction conditions, including the addition of water and methanol as a static modifier, were used to assess the extractability of these pesticides, and the addition of methanol was demonstrated to improve the extraction of all the studied pesticides.     

Wave hydrodynamics around a multi-functional artificial reef at Leirosa

This paper describes an application of the Boussinesq-type COULWAVE model to study the wave hydrodynamics in the vicinity of a multi-functional artificial reef (MFAR). This reef is under investigation and consists of a supplementary protection solution for the Leirosa sand dune system located at South of Figueira da Foz, on the Portuguese West coast. Such installation near the coastline is expected to contribute to enhance the surfing conditions in the area, protect the sand dune system in the surroundings of Leirosa beach, and increase its environmental value. Numerical calculations with the COULWAVE model were performed for four test cases, considering two reef geometries (differing in the reef angle) and two incident wave conditions (storm condition and a common wave condition). Comparisons between the results obtained, in terms of wave heights and breaking line positions allow us to assess the influence of the reef on the hydrodynamics near the beach and around the reef. Moreover, the reef performance was analysed in terms of surfability and coastal protection. The surfability parameters (breaker height, Iribarren number and peel angle) were calculated for each test case using the numerical wave heights, wave directions and wave breaking positions. Comparisons of parameters allow characterizing the most appropriate configuration of the reef to improve the surfing conditions in the study area. A methodology based on numerical free surface elevations and horizontal velocity components was developed to calculate wave directions, since this is not a direct output of the COULWAVE model. Concerning coastal protection, analyses of the mean currents around the reef were used together with observations of the velocity cells near the shoreline as an indication of the sediment transport.     

Application of Sensitivity and Flux Analyses for the Reduction of Model Predicting the Photooxidative Degradation of an Azo Dye in Aqueous Media

The prediction of the system behavior is of significant interest when evaluating appropriate technologies for wastewater treatment. The robust prediction could be achieved by empirical mathematical modeling techniques, but they do not include steps in degradation of organic pollutants. Mechanistic models (MM) include chemical/physical phenomena, but may also include numerous reactions resulting with the complicated kinetic expressions with large number of parameters. This modeling approach can be challenging for complex system such as advanced oxidation processes. With the goal to reduce the number of reactions involved in developed MM, keeping the high prediction power, sensitivity, and flux analyses was employed. The results showed that MM describing the degradation of organic dye in water matrix by photooxidation processes can be significantly simplified, by reducing the number of reactions included without affecting the predictive power. The calculated root mean square deviation values between data predicted by MM and reduced MM_R differ insignificantly (≤1.4 %).     

Nest-seeking rock ants (Temnothorax albipennis) trade off sediment packing density and structural integrity for ease of cavity excavation

We investigated excavation and nest site choice across sediment-filled cavities in the ant Temnothorax albipennis. Colonies were presented with sediment-filled cavities, covering a spectrum from ones that should be quick to excavate but will form a weak enclosing wall to those that should be slow to excavate but form a strong wall. Overall, colonies only showed a significant preference for cavities that were fastest to excavate over those that were slowest. The speed of decision making and moving appears paramount over the suitability of the sediment for forming an enclosing wall. The mechanism behind the choice is the differential between the rates at which alternatives are excavated and accumulate ants. The rates for a particular type of cavity were unaffected by the type with which it was paired. This suggests that there is no significant competition between sites during the decision-making process. Certain colonies were able consistently to discriminate across more closely matched alternatives. These colonies required a greater number of ants to be present and took longer before beginning to move. A race is run between alternatives to become habitable but the process may be tuned across colonies such that it may run for longer and an incorrect or split decision is less likely.     

A 2019 Outbreak Investigation of Hepatitis A Virus Infections in the United States Linked to Imported Fresh Blackberries

Globally, hepatitis A virus (HAV) is one of the most common agents of acute viral hepatitis and causes approximately 1.4 million cases and 90,000 deaths annually despite the existence of an effective vaccine. In 2019, federal, state, and local partners investigated a multi-state outbreak of HAV infections linked to fresh blackberries sourced from multiple suppliers in Michoacán, Mexico. A total of 20 individuals with outbreak-related HAV infection were reported in seven states, including 11 hospitalizations, and no deaths. The Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and Nebraska State and Douglas County Health Departments conducted a traceback investigation for fresh blackberries reportedly purchased by 16 ill persons. These individuals reported purchasing fresh blackberries from 11 points of service from September 16 through 29, 2019 and their clinical isolates assessed through next-generation sequencing and phylogenetic analysis were genetically similar. The traceback investigation did not reveal convergence on a common grower or packing house within Mexico, but all of the blackberries were harvested from growers in Michoacán, Mexico. FDA did not detect the pathogen after analyzing fresh blackberry samples from four distributors, one consumer, and from nine importers at the port of entry as a result of increased screening. Challenges included gaps in traceability practices and the inability to recover the pathogen from sample testing, which prohibited investigators from determining the source of the implicated blackberries. This multi-state outbreak illustrated the importance of food safety practices for fresh produce that may contribute to foodborne illness outbreaks.