Regulatory factors and structure of a component population of the spionid Polydora bioccipitalis infesting the surf clam Mesodesma donacium

Spionidae, particularly polydorids, are common polychaete parasites of edible mollusks around the world. However, our understanding of the regulatory factors and population structure of these parasites is scant. In this study involving Polydora bioccipitalis and the surf clam Mesodesma donacium we evaluated (1) the environmental correlates of the prevalence and mean intensity of the infestation, (2) the relationship between the number of egg capsules and juvenile and adult parasites and the time elapsed since infestation, and (3) the spatial patterns of juveniles and adults within the host. Environmental factors showed no significant correlations with prevalence and mean intensity, suggesting that these factors do not act directly as regulators. Rather, storm surges seemingly induced clam stranding, which in turn affected both the prevalence and intensity of the infestation. The numbers of juveniles and egg capsules in blisters were significantly related to the time since infestation, suggesting mechanisms of use and expansion of the space within the host. Juvenile worms showed an aggregated distribution that was probably related to the episodic nature of infestation events, whereas adults exhibited uniform distributions that probably reflect territorial behavior and reproductive strategies.     

Chemometrical characterization of four italian rice varieties based on genetic and chemical analyses

This paper describes a method for achieving qualitative identification of four rice varieties from two different Italian regions. To estimate the presence of genetic diversity among the four rice varieties, we used polymerase chain reaction-randomly amplified polymorphic DNA (PCR-RAPD) markers, and to elucidate whether a relationship exists between the ground and the specific characteristics of the product, we studied proximate composition, fatty acid composition, mineral content, and total antioxidant capacity. Using principal component analysis on genomic and compositional data, we were able to classify rice samples according to their variety and their district of production. This work also examined the discrimination ability of different parameters. It was found that genomic data give the best discrimination based on varieties, indicating that RAPD assays could be useful in discriminating among closely related species, while compositional analyses do not depend on the genetic characters only but are related to the production area.     

Thirty Years of Chemical Changes in Alpine Acid-Sensitive Lakes in the Alps

The Pennask Creek watershed in British Columbia (BC), Canada has been contaminated with acid rock drainage (ARD) and associated metal leaching (ML) as a result of highway construction. By combining existing and newly gathered information, this study determined the extent of metal contamination of the water and sediments, the potential biological impacts of this contamination, the influence of local geology, and estimated the potential risk to aquatic organisms. Surface water and sediment samples from the watershed were analyzed for general chemical parameters and trace metals. Rock samples were analyzed for mineralogy and chemical composition. Metal concentrations in water and sediments downstream of the ARD/ML source were higher than elsewhere in the watershed. Metals of concern include aluminum (Al), copper (Cu), and zinc (Zn). Analysis of historical water quality data indicated that the concentrations of these metals have decreased markedly since 2004, due to remediation efforts. Rock samples collected from the streambeds and banks were not found to be potentially acid generating, but did contain significant levels of metals. Al, Cu, and Zn levels consistently exceeded BC water and sediment quality guidelines for the protection of aquatic life, indicating that adverse biological effects are probable at stations downstream of the ARD/ML source. Benthic invertebrate monitoring over a 10-year period showed low abundance and diversity and a complete absence of sensitive taxa at downstream stations. Risk quotients indicated a likelihood of adverse biological effects for aquatic organisms, including rainbow trout, due to metal contamination in the watershed.     

Conformation of the Z19 prolamin by FTIR, NMR, and SAXS

The alpha zein, the maize storage prolamin, is a mixture of several homologous polypeptides that shows two bands in SDS-PAGE, called Z19 and Z22. The conformation studies carried out by several authors in this mixture are conflicting. To elucidate these inconsistencies, we analyzed the conformation of the Z19 fraction, extracted from BR451 maize variety by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and small-angle X-ray scattering. The infrared results show that Z19 has 46% of alpha helix and 22% of beta sheet. The fast N-H to N-D exchange measured by (1)H NMR spectroscopy showed that Z19 is not a compact structure. The scattering measurements indicated an extended structure with 12 by 130 A. With these data, we have modeled the Z19 structure as a hairpin, composed of helical, sheet, turns, and secondary structures, folded back on itself.     

Alcohol consumption impairs detection of performance errors in mediofrontal cortex

The anterior cingulate cortex (ACC) is a critical component of the human mediofrontal neural circuit that monitors ongoing processing in the cognitive system for signs of erroneous outcomes. Here, we show that the consumption of alcohol in moderate doses induces a significant deterioration of the ability to detect the activation of erroneous responses as reflected in the amplitude of brain electrical activity associated with the ACC. This impairment was accompanied by failures to instigate performance adjustments after these errors. These findings offer insights into how the effects of alcohol on mediofrontal brain function may result in compromised performance.     

Compositional and tissue modifications induced by the natural fermentation process in table olives

Olive fruits contain high concentrations of phenols that include phenolic acids, phenolic alcohols, flavonoids, and secoiridoids. The final concentration of phenols is strongly affected by brine conditions. The factors involved in modification by brine are still partially unknown and can include hydrolysis of secoiridoid glucosides and the release of hydrolyzed products. In this study olives from various Italian cultivars were processed by natural fermentation (e.g., without a preliminary treatment of olives with NaOH) using a selected Lactobacillus strain. Processed olives are characterized by a low phenolic concentration of phenols, consisting mainly of phenyl alcohols, verbascoside, and the dialdehydic form of decarboxymethylelenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), whereas a high level of phenols occurs in olive brine from all the cultivars studied. Olives of the Coratina cultivar, control and with fermentation by Lactobacillus pentosus 1MO, were analyzed in a frozen hydrated state by cryo scanning electron microscopy and energy-dispersive X-ray microanalysis, on both surface and transversal freeze-fracture planes. Structural modifications, found in olives after fermentation, may explain the phenol release in brine.     

Study and characterization of polyphenol oxidase from eggplant (Solanum melongena L.)

In this study the catecholase and cresolase activities of eggplant polyphenol oxidase (PPO) were investigated. Enzyme activity was determined by measuring the increase in absorbance using catechol as substrate and 3-methyl-2-benzothiazolinone hydrazone (MBTH) as coupled reagent. The effects of substrate specificity, heat inactivation, temperature, pH, and inhibitors were investigated to understand the enzymatic alteration of ready-to-eat preparations. Browning of vegetables was determined through a colorimeter. Decrease of lightness (L*) and increase of color difference values (ΔE*) were correlated with tissue browning. Antibrowning agents were tested on PPO under the same conditions. The enzyme activity was strongly inhibited by 0.4 M citric acid. Under natural pH conditions, the enzyme was also inhibited by tartaric acid and acetic acid. All of the results were used to understand the best conditions for food transformation (ready-to-eat and grilled eggplant slices).     

Lab-scale feasibility tests for sediment treatment using different physico-chemical techniques

Purpose  

The fairly high amounts of sediments dredged in coastal or internal water bodies for navigational and/or environmental purposes claims for the identification of appropriate management strategies. Dredged sediments are frequently affected by organic and inorganic contamination, so that their reuse, as an alternative to final landfill disposal, could need remediation. In this framework, a two-year joint research project was carried out to assess the feasibility of different remediation technologies for the treatment of polluted sediments.