Poorly crystalline iron and aluminium oxides contribute to the carbon saturation and sorption of dissolved organic carbon in the soil

Soil carbon (C) saturation implies an upper limit to a soil's capacity to store C depending on the contents of silt + clay and poorly crystalline Fe and Al oxides. We hypothesized that the poorly crystalline Fe and Al oxides in silt + clay fraction increased the C saturation and thus reduced the capacity of the soil to sorb additional C input. To test the hypothesis, we studied the sorption of dissolved organic carbon (DOC) on silt + clay fractions (<53 µm) of highly weathered oxic soils, collected from three different land uses (i.e., improved pasture, cropping and forest). Soils with high carbon saturation desorbed 38% more C than soils with low C saturation upon addition of DOC, whereas adsorption of DOC was only observed at higher concentration (>15 g kg^?1). While high Al oxide concentration significantly increased both the saturation and desorption of DOC, the high Fe oxide concentration significantly increased the desorption of DOC, supporting the proposition that both oxides have influence on the DOC sorption in soil. Our findings provide a new insight into the chemical control of stabilization and destabilization of DOC in soil.     

The ecosystem services concept: a new Esperanto to facilitate participatory planning processes?

Landscape Ecology - Several case studies investigated the role of ecosystem services in participatory planning processes. However, no systematic study exists that cuts across a large number of...     

Genetic variation in root development responses to salt stresses of quinoa

Soil salinity has become a serious environmental abiotic stress limiting crop productivity and quality. The root system is the first organ sensing the changes in salinity. Root development under elevated salinity is therefore an important indicator for saline tolerance in plants. Previous studies focused on varietal differences in morphological traits of quinoa under saline stresses; however, variation in root development responses to salinity remains largely unknown. To understand the genetic variation in root development responses to salt stress of quinoa, we conducted a preliminary screening for salinity response at two salinity levels of a diverse set of 52 quinoa genotypes and microsatellite markers were used to link molecular variation to that in root development responses to salt stresses of represented genotypes. The frequency distribution of saline tolerance index showed continuous variation in the quinoa collection. Cluster analysis of salinity responses divided the 52 quinoa genotypes into six major groups. Based on these results, six genotypes representative of groups I to VI including Black quinoa, 2-Want, Atlas, Riobamba, NL-6 and Sayaña, respectively, were selected to evaluate root development under four saline stress levels: 0, 100, 200 and 300 mM NaCl. Contrasts in root development responses to saline stress levels were observed in the six genotypes. At 100 mM NaCl, significant differences were not observed in root length development (RLD) and root surface development (RSAD) of most genotypes except Black quinoa; a significant reduction was observed in this genotype as compared to controls. At 200 mM NaCl, significant reduction was detected in RLD and RSAD in all genotypes showing this as the best concentration to discriminate among genotypes. The strongest inhibition of root development was found for all genotypes at 300 mM NaCl as compared to lower saline levels. Among genotypes, Atlas of group III shows as a saline-tolerant genotype confirming previous reports. Variation in root responses to salinity stresses is also discussed in relation to climate conditions of origins of the genotypes and reveal interesting guidelines for further studies exploring the mechanisms behind this aspect of saline adaptation.     

Naringin-loaded Poly(ε-caprolactone)/Gelatin Electrospun Mat as a Potential Wound Dressing: In vitro and In vivo Evaluation

In the present study, naringin, a flavonoid isolated from the grape and citrus fruit species, was incorporated with poly(ε-caprolactone)/gelatin composite mats in order to develop a potential wound dressing. The composite mats were prepared by electrospinning of poly(ε-caprolactone)/gelatin (1:1 (w/w)) solution incorporated with 1.50 %, 3 % and 6 % (w/w) of naringin. The electrospun mats were evaluated regarding their morphology, contact angle, water-uptake capacity, water vapor transmission rate, tensile properties, drug release, cellular response and in vivo wound healing activity. The study showed that after 2 weeks, the full-thickness excisional wounds of Wistar rats treated with the naringin-loaded dressings achieved a wound closure of higher than 94 % and the dressing containing 6 % (w/w) naringin had almost 100 % wound closure. The sterile gauze, as the control group, showed nearly 86 % of wound closure after this period of time. Our results provided evidence that supports the possible applicability of naringin-loaded wound dressing for successful wound treatment.     

Swim bladder inflation as a possible cause of saddleback-like syndrome malformation in hatchery-reared red spotted grouper <Emphasis Type="Italic">Epinephelus akaara</Emphasis>

Saddleback-like syndrome is one of the most frequently observed malformations in hatchery-reared red spotted grouper Epinephelus akaara. Saddleback-like syndrome is characterized by a V-shaped dorsal-profile depression behind the head region accompanied by deformities or misalignments of the first to fourth neural spines on the vertebral column and the first to fourth pterygiophores of the dorsal fin. Abnormal swim bladder inflation in several finfish species leads to malformations, particularly of the vertebral column. The present study examined the influence of swim bladder inflation on saddleback-like syndrome in hatchery-reared red spotted grouper. The incidence of saddleback-like syndrome increased as swim bladder inflation rate increased. Additionally, the incidence of saddleback-like syndrome among juveniles with inflated swim bladders was significantly higher than that among juveniles with uninflated swim bladders. The larval swim bladder is located just below the first to fifth vertebrae and the first to fifth dorsal spines, where saddleback-like syndrome occurs. Our results suggest that an inflated swim bladder increases the risk of saddleback-like syndrome in hatchery-reared red spotted grouper.     

Cylindrospermopsin effects on cell viability and redox milieu of Neotropical fish <Emphasis Type="Italic">Hoplias malabaricus</Emphasis> hepatocytes

Cylindrospermopsin (CYN) is a cyanotoxin that is cytotoxic to a wide variety of cells, particularly to the hepatocytes. In this study, the toxic effects of purified CYN were investigated in primary cultured hepatocytes of Neotropical fish Hoplias malabaricus. After isolation, attachment, and recovery for 72 h, the cells were exposed for 72 h to 0, 0.1, 1.0, 10, and 100 μg l^?1 of CYN. Then, cell viability and a set of oxidative stress biomarker responses were determined. Catalase, superoxide dismutase, glucose-6-phosphate dehydrogenase, and glutathione S-transferase activities were not affected by exposure to CYN. Concentration-dependent decrease of glutathione reductase activity occurred for most CYN-exposed groups, whereas non-protein thiol content increased only for the highest CYN concentration. Lipid peroxidation, protein carbonylation, and DNA damage levels were not altered, but reactive oxygen species levels increased in the cells exposed to the highest concentration of CYN. Cell viability decreased in all the groups exposed to CYN. Thus, CYN may cause a slight change in redox balance, but it is not the main cause of cell death in H. malabaricus hepatocytes.     

Most fish destined for fishmeal production are food‐grade fish

Marine fisheries target and catch fish both for direct human consumption (DHC) as well as for fishmeal and fish oil, and other products. We derived the fractions used for each for 1950–2010 by fishing country, and thus provide a factual foundation for discussions of the optimal use of fisheries resources. From 1950 to 2010, 27% (~20 million tonnes annually) of globally reconstructed marine fisheries landings were destined for uses other than DHC. Importantly, 90% of fish destined for uses other than DHC are food‐grade or prime food‐grade fish, while fish without a ready market for DHC make up a much smaller proportion. These findings have implications for how we are using fish to feed ourselves or, more appropriately, how we are not using fish to feed ourselves.     

Androgen-induced pseudo-hermaphroditic phenotypes in female <Emphasis Type="Italic">Brevimyrus niger</Emphasis> Günther 1866 (Teleostei,Mormyridae)

This paper explores the plasticity of sexually dimorphic characters in subadult female Brevimyrus niger, an African weakly electric mormyrid species. Thirty-five fish were exposed in a staggered fashion (five fish a week) to aromatizable 17α-methyltestosterone over a period of 7 weeks; 18 fish served as untreated controls. 17α-MT induced precocious vitellogenesis that mirrored the natural maturational process during seasonal ovarian recrudescence. At the same time, 17α-MT exposure resulted in complete masculinization of the females’ anal fin support structure normally observed during rainy season in adult males. We discuss possible hormonal mechanisms acting along the brain-pituitary-gonad axis that would explain the occurrence of precocious vitellogenesis and the male-typical transformation of the female’s anal fin ray bases. Our findings are relevant to commercial aquaculture as the use of 17α-MT in fish hatcheries can pose serious environmental issues.