Soil and Sediment Geochemistry of the Iron Quadrangle, Brazil The Case of Arsenic

Soils and sediments around gold ore deposit and mining sites in the Iron Quadrangle present positive As anomalies (median concentrations > 100 mg kg^-1) and wide ranges (< 20 to > 2000 mg kg^-1) even in densely populated areas. These anomalies can be related to geological structures, to hydrothermal ore deposits and to their continuous exploitation over the past three centuries. The paper presents new data on both As geochemistry and soil and sediment geochemistry in general, and discusses consequences of the encountered anomalies, their reasons and potential effects and how they compare with current screening and threshold values. While surface soil As-val-ues are reproducible at a given site, sediment anomalies show a strong seasonal variation that can be explained by tropical hydrologicai variances. Suggestions are presented on how to minimize the As-load in densely populated areas that might otherwise pose a potential health risk.     

Role of the Endothelium in the Biotransformation of Sodium Nitroprusside (SNP): In vivo and In vitro Study

Veterinary Research Communications -     

Transgenic plants expressing immunosuppressive dsRNA improve entomopathogen efficacy against Spodoptera littoralis larvae

Journal of Pest Science - Transgenic plants that express double-stranded RNA (dsRNA) targeting vital insect genes have recently emerged as a valuable new tool for pest control. In this study,...     

Adapting to changing poaching intensity of yellow-shouldered parrot (Amazona barbadensis) nestlings in Margarita Island, Venezuela

The yellow-shouldered parrot (Amazona barbadensis) is listed in Venezuela as Endangered and internationally as Vulnerable, primarily due to poaching for the illegal pet trade. Various interventions have been implemented to reduce poaching (increasing the population from 700 in 1989 to 1600 in 2009), but poaching pressure is still high, and is ever-changing, requiring an evolving response. Between 2000 and 2003, our only intervention was environmental education in schools: in the short term, unsurprisingly, it had no impact on poaching, which reached 100% of nestlings in monitored nests. From 2004 onwards, we implemented a set of new field interventions. In 2004, 24 h field surveillance decreased poaching to 56%. In 2005, the addition of foster nests and a pilot test of “assisted breeding” brought the figure down to 18%. In 2006, assisted breeding was expanded, achieving 0% poaching. In 2007, poachers raided our “secure” site, and took 34 nestlings, bringing poaching up to 60%. A pilot study of artificial nests offered promising results. In 2008 and 2009, the addition of patrolling by local police reduced poaching to 16% and 1%, respectively. During 2004–2009, nestling poaching averaged 25%. Ensuring parrot recruitment in the future will require a combination of the strategies employed to date; in the short term, expanding the use of artificial nests to increase availability of nesting sites in easily-patrolled areas has the most potential to build on past successes.     

Single-gene greenbeard effects in the social amoeba Dictyostelium discoideum

Selection can favor reproductive altruism if an altruism allele aids copies of itself by helping relatives. The alternative "greenbeard" mechanism, in which an allele directly recognizes and aids copies of itself in others, is generally thought to be too complex for a single gene to carry out. The csA gene in Dictyostelium discoideum acts as a single-gene greenbeard. When wild-type cells are mixed with csA-knockout cells, the wild type is more altruistic, but is also able preferentially to direct the benefits to other wild-type cells. Both properties derive directly from homophilic cell adhesion of the protein encoded by csA.     

Marine Anthraquinones: Pharmacological and Toxicological Issues

The marine ecosystem, populated by a myriad of animals, plants, and microorganisms, is an inexhaustible reservoir of pharmacologically active molecules. Among the multiple secondary metabolites produced by marine sources, there are anthraquinones and their derivatives. Besides being mainly known to be produced by terrestrial species, even marine organisms and the uncountable kingdom of marine microorganisms biosynthesize anthraquinones. Anthraquinones possess many different biological activities, including a remarkable antitumor activity. However, due to their peculiar chemical structures, anthraquinones are often associated with toxicological issues, even relevant, such as genotoxicity and mutagenicity. The aim of this review is to critically describe the anticancer potential of anthraquinones derived from marine sources and their genotoxic and mutagenic potential. Marine-derived anthraquinones show a promising anticancer potential, although clinical studies are missing. Additionally, an in-depth investigation of their toxicological profile is needed before advocating anthraquinones as a therapeutic armamentarium in the oncological area.     

Evolution of surface properties and organic matter stabilisation in podzolic B horizons as assessed by nitrogen and phosphate sorption

In podzolic B horizons illuviated Al, Fe and organic matter (OM) increase with the ongoing of the pedogenic process. Depending on OM load on mineral surfaces, modifications of the soil surface properties are expected and may influence OM stabilisation. The proportion of labile organic pools should thus vary depending on the type of podzolic horizon. In this work, we selected B horizons at increasing intensity of podzolisation, evaluated the labile OM pools through oxidation with 2 % NaClO and characterised surface properties with N₂ and phosphate sorption. Before and after oxidation, we assessed the NaOH-extractable OM fractions. Oxidation was more effective on the least polar organic compounds and led to an increase in the fulvic to humic acid ratio. Specific surface area (SSA) increased after oxidation only in the least podzolised horizons, while selectively preserved OM induced a decrease in SSA in the more developed Bs, Bsm and Bhs. Phosphate sorption induced a release of OM and always decreased after oxidation, although variations in P affinity for the surfaces were observed. The effect of oxidation on surface parameters pointed to a specific association between organics and minerals that changed during soil development. At the very beginning of podzolisation, the dominant forms seemed related to organo-metallic complexes with little interaction with surfaces. With Bs development, weak interactions between mineral surfaces and OM appeared, while at a later stage OM differentiated into bulky structures and tightly bound, rigid ones, with extremely low N₂ accessibility. The latter were not sensitive to low concentration NaClO while the former were easily oxidised.     

Encapsulation of Carlina acaulis essential oil and carlina oxide to develop long-lasting mosquito larvicides: microemulsions versus nanoemulsions

Journal of Pest Science - Carlina acaulis root essential oil (EO) is one of the most potent mosquito larvicides (LC50?&lt;?2&nbsp;ppm). This EO is mainly composed of carlina...     

Phagocytosis of Astaxanthin-Loaded Microparticles Modulates TGFβ Production and Intracellular ROS Levels in J774A.1 Macrophages

Radiation-induced fibrosis is a serious long-lasting side effect of radiation therapy. Central to this condition is the role of macrophages that, activated by radiation-induced reactive oxygen species and tissue cell damage, produce pro-inflammatory cytokines, such as transforming growth factor beta (TGFβ). This, in turn, recruits fibroblasts at the site of the lesion that initiates fibrosis. We investigated whether astaxanthin, an antioxidant molecule extracted from marine and freshwater organisms, could help control macrophage activation. To this purpose, we encapsulated food-grade astaxanthin from Haematococcus pluvialis into micrometer-sized whey protein particles to specifically target macrophages that can uptake material within this size range by phagocytosis. The data show that astaxanthin-loaded microparticles are resistant to radiation, are well-tolerated by J774A.1 macrophages, induce in these cells a significant reduction of intracellular reactive oxygen species and inhibit the release of active TGFβ as evaluated in a bioassay with transformed MFB-F11 fibroblasts. Micro-encapsulation of bioactive molecules is a promising strategy to specifically target phagocytic cells and modulate their own functions.     

Benzothiadiazole and BABA improve resistance to <Emphasis Type="Italic">Uromyces pisi</Emphasis> (Pers.) Wint. in <Emphasis Type="Italic">Pisum sativum</Emphasis> L. with an enhancement of enzymatic activities and total phenolic content

Benzothiadiazole (BTH) and DL-β-aminobutyric acid (BABA) induced systemic resistance was investigated in susceptible and resistant pea genotypes against Uromyces pisi. Resistance was characterized by reduced infection frequency mainly due to decreases in appressorium formation, stomatal penetration, growth of infection hyphae and haustorium formation. Changes in β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase and peroxidase activities and in total phenolics content, demonstrate that U. pisi resistance is induced by BTH and BABA treatments at early and late stages of the fungal infection process, but that the chemicals operate via different mechanisms. In fact, our study showed that BTH treatment primed the activity of pathogenesis related-proteins such as β-1,3-glucanase, chitinase and peroxidase in both susceptible and resistant genotypes. On the other hand, BABA treatment did not increase the enzymatic activities in the studied genotypes, but significantly increased their total phenolic contents.