Deposition of gold mining tailings in tropical soils: metal pollution and toxicity to earthworms

Journal of Soils and Sediments - This study consists of the evaluation of metals acute toxicity levels taking into consideration a hypothetic scenario of dam breaking and land deposition of two...     

Opportunity costs: Who really pays for conservation?

Designing conservation areas entails costs that, if considered explicitly, can be minimized while still achieving conservation targets. Here we focus on opportunity costs which measure forgone benefits from alternative land uses. Conservation planning studies often use partial estimates of costs, but the extent to which these result in actual efficiencies has not been demonstrated. Our study partitions land costs into three distinct opportunity costs to smallholder agriculture, soybean agriculture and ranching. We demonstrate that opportunity costs to single stakeholder groups can be inaccurate measures of true opportunity costs and can inadvertently shift conservation costs to affect groups of stakeholders disproportionately. Additionally, we examine how spatial correlations between costs as well as target size affect the performance of opportunity costs to single stakeholder groups as surrogate measures of true opportunity costs. We conclude that planning with opportunity costs to single stakeholder groups can result in cost burdens to other groups that could undermine the long-term success of conservation. Thus, an understanding of the spatial distributions of opportunity costs that are disaggregated to groups of stakeholders is necessary to make informed decisions about priority conservation areas.     

Seawater causes rapid trace metal mobilisation in coastal lowland acid sulfate soils: Implications of sea level rise for water quality

Coastal floodplains are highly vulnerable to inundation with saline water and the likelihood of inundation will increase with sea level rise. Sediment samples from floodplains containing coastal lowland acid sulfate soils (CLASS) in eastern Australia were subjected to increasing seawater concentration to examine the probable effects of sea level rise on acidity and metal desorption. Ten soils were mixed with synthetic seawater concentrations varying from 0% to 100% at a solid:solution ratio of 1:10 for 4 h. There was a slight decrease in pH (≈ 0.5 units) with increasing seawater concentration following treatment, yet, calculated acidity increased significantly. In most soil treatments, Al was the dominant component of the calculated acidity pool. Al dominated the exchange complex in the CLASS and, correspondingly, was the major metal ion desorbed. In general, concentrations of soluble and exchangeable Al, Fe²⁺, Ni, Mn and Zn in all soil extracts increased with increasing salinity. Increasing trace metal concentrations with increasing seawater concentration is attributed to the combined effects of exchange processes and acidity. The increasing ionic strength of the seawater treatments displaces trace metals and protons adsorbed on sediments, causing an initial decrease in pH. Hydrolysis of desorbed acidic metal cations can further contribute to acidity and increase mobilisation of trace metals. These findings imply that saline inundation of CLASS environments, even by relatively brackish water may cause rapid, shorter-term water quality changes and a pulse release of acidity due to desorption of acidic metal cations.     

Effect of harvesting and drying conditions on chlorophyll levels of soybean (Glycine max L. Merr)

Chlorophyll in soybean represents a downgrading factor for the crops. Five Brazilian cultivars were harvested between R(6) and R(8) stage of development (Fehr & Caviness scale) and dried at 25 degrees and 40 degrees C. The effect of maturity stages and two drying conditions after harvest were studied to achieve reduction of moisture and chlorophylls to acceptable levels. When seeds were dried at 25 degrees C, even harvesting at early stages of development such as R(6), the green pigments were almost degraded, and 16 ppm of chlorophyll were found at maximum, accompanied by loss of moisture. Moisture and chlorophyll declines as seed matures, but at intermediary stages (R(6)-R(7)), chlorophyll degrades first, so the rate of moisture loss should not be used to predict chlorophyll contents. At 40 degrees C, complete degradation of chlorophyll pigments is only achieved when seeds are swathed from R(7) stage up, otherwise the seed quality could be compromised. Slow drying allows almost complete removal of green pigments, even when seeds are swathed a few days before the physiological maturity stage.     

It is the ambience,not the menu. Prey availability does not drive habitat selection by the endangered Pyrenean desman

1. The Pyrenean desman (Galemys pyrenaicus) is an endangered stream-dwelling insectivore endemic to the Iberian Peninsula and the north of the Pyrenees. It favours riffles over slow habitats such as runs or pools, yet it is still unclear whether habitat preference is based on prey availability or on other factors, such as mechanical constraints on its hunting habits.
2. Desman diet and prey selection were analysed along the pristine Elama Stream and the slightly modified Leitzaran Stream in the Basque Country, Spain.
3. In each stream the prey consumed were identified by metabarcoding 94 desman faeces, and prey availability characterized from 10 Surber samples taken in each habitat type (riffles, runs and pools). Invertebrates were sorted and identified, the biomass of each taxon was calculated, and their DNA was also extracted, amplified using PCR, and sequenced to build a reference database.
4. Prey availability and diet varied between streams. Desmans positively selected shredders and invertebrates that live on the substrate, and selected against taxa that live in fine sediment, taxa with hard shells or those that are highly mobile. The diet of desmans was more selective in the Elama, the stream with better ecological status. Food availability did not differ among habitats, and therefore does not explain the preference of desmans for riffles; rather, mechanical constraints to deal with buoyancy and physical habitat heterogeneity were hypothesized to be the reason behind the habitat preference.
5. The results suggest that promoting the formation of riffles in streams can improve the situation of some desman populations living in degraded habitats.

     

Effects of no‐take area size and age of marine protected areas on fisheries yields: a meta‐analytical approach

Marine protected areas (MPAs) are often promoted as tools for biodiversity conservation as well as for fisheries management. Despite increasing evidence of their usefulness, questions remain regarding the optimal design of MPAs, in particular concerning their function as fisheries management tools, for which empirical studies are still lacking. Using 28 data sets from seven MPAs in Southern Europe, we developed a meta‐analytical approach to investigate the effects of protection on adjacent fisheries and asking how these effects are influenced by MPA size and age. Southern European MPAs showed clear effects on the surrounding fisheries, on the ‘catch per unit effort’ (CPUE) of target species, but especially on the CPUE of the marketable catch. These effects depended on the time of protection and on the size of the no‐take area. CPUE of both target species and the marketable catch increased gradually by 2–4% per year over a long time period (at least 30 years). The influence of the size of the no‐take area appeared to be more complex. The catch rates of the entire fishery in and around the MPA were higher when the no‐take areas were smaller. Conversely, catch rates of selected fisheries that were expected to benefit most from protection increased when the no‐take area was larger. Our results emphasize the importance of MPA size on its export functions and suggest that an adequate, often extended, time frame be used for the management and the evaluation of effectiveness of MPAs.     

Oral anatomy of the dog and cat in veterinary dentistry practice.

The study of anatomy is important to accomplish any kind of surgical and medical procedure and to understand the physiology and diseases of animals. It is no different in veterinary dentistry. The study of oral anatomy helps the veterinarian to accomplish any kind of surgical procedure more quickly and with less damage to tissues, especially in cases of major oral surgery. In fact, under-standing the anatomy is easier when this knowledge is acquired directly, with surgical application. This article describes the essentials of the oral anatomy of the dog and cat, correlating this knowledge with the dental procedures to be used by veterinarians as a guide.     

alpha(1)-Acid glycoprotein modulates apoptosis in bovine monocytes

alpha(1)-Acid glycoprotein (AGP, orosomucoid) is a normal constituent of bovine blood. AGP is an immunocalin, a binding protein that can also exert several immunomodulatory functions. In this paper we investigated the effect of bovine alpha(1)-acid glycoprotein (boAGP) on spontaneous and staurosporine-induced apoptosis of blood derived monocytes purified using magnetic cell sorting techniques. Bovine AGP was purified from blood following a chromatographic protocol. The homogeneous protein was used to stimulate the cells as well to raise a polyclonal antibody, that was used throughout all the experiments. When monocytes were incubated with high concentrations of boAGP (0.9 mg/ml), similar to those found in bovine plasma during systemic reaction to inflammation, their spontaneous apoptosis rate was suppressed, as determined by caspase-3/7 enzymatic activity assay. Similar results were obtained when apoptosis was induced by adding staurosporine, a potent protein kinase inhibitor. The apoptosis-modulating activity of boAGP was dependent on its concentration, since physiological concentrations of boAGP (0.3 mg/ml) did not exhibit a statistically significative anti-apoptotic activity. We also investigated whether this apoptosis-modulating activity was dependent on the terminal sialic acid residues exposed on the surface of the protein. Enzymatic treatment with neuraminidase, that cleaves terminal sialic acid residues, completely abolished boAGP's anti-apoptotic activity. These results suggest that the protective effect of AGP is likely mediated by its sialic acid terminal groups.