Photochemical persistence of sulfa drugs in aqueous medium: kinetic study and mathematical simulations

Environmental Science and Pollution Research - This study aimed at investigating the photochemical behavior of sulfa drugs containing five and six-membered heterocyclic substituents...     

Effect of hybridization with genome exclusion on extinction risk

Human‐induced habitat changes may lead to the breakdown of reproductive barriers between distantly related species. This phenomenon may result in fertile first‐generation hybrids (F₁) that exclude the genome of one parental species during gametogenesis, thus disabling introgression. The species extinction risk associated with hybridization with genome exclusion is largely underappreciated because the phenomenon produces only F₁ hybrid phenotype, leading to the misconception that hybrids are sterile and potentially of minor conservation concern. We used a simulation model that integrates the main genetic, demographic, and ecological processes to examine the dynamics of hybridization with genome exclusion. We showed that this mode of hybridization may lead to extremely rapid extinction when the process of genome exclusion is unbalanced between the interbreeding species and when the hybridization rate is not negligible. The coexistence of parental species was possible in some cases of asymmetrical genome exclusion, but show this equilibrium was highly vulnerable to environmental variation. Expanding the exclusive habitat of the species at risk allowed its persistence. Our results highlight the extent of possible extinction risk due to hybridization with genome exclusion and suggest habitat management as a promising conservation strategy. In anticipation of serious threats to biodiversity due to hybridization with genome exclusion, we recommend a detailed assessment of the reproductive status of hybrids in conservation programs. We suggest such assessments include the inspection of genetic content in hybrid gametes.     

Framework for high-resolution climate change impact assessment on grapevines at a regional scale

Understanding the impacts of climate change on viticulture is especially essential in those areas producing high-quality wines. In this work, we create an operational framework to investigate climate change impact on viticulture in the Tuscany region (central Italy) the viticulture industry of which relies on producing high-quality wines to compete in a global market. The framework includes (i) statistical downscaling of General Circulation Model (GCM) outputs for the period 1975–2099 to a local scale; (ii) the use of downscaling outputs as driving variables in specific simulation models; (iii) the spatial interpolation of model outputs to feed an economic and (iv) a quality model. The results show that as a consequence of a progressive increase in temperature and a decrease in rainfall, (a) the area potentially suitable for grapevine cultivation increases; (b) the grapevine growth cycle becomes shorter; (c) the final yield is gradually reduced, particularly in those areas characterised by quality cultivation regulation; and d) the premium wine quality production areas shift towards higher elevations. The proposed framework revealed itself to be an effective tool for climate change impact assessment at a very local scale. Additionally, this approach may be easily extended to testing the effect of different adaptation strategies in terms of management practices (e.g. irrigation) and grape varieties (e.g. longer or shorter cycle, advanced or delayed bud burst).     

Pesticides alter ion transport across frog (Pelophylax kl. esculentus) skin

We have measured, in the edible frog (Pelophylax kl. esculentus), the effect of two fungicides (8-hydroxyquinoline and captan), and four herbicides (DCMU, glyphosate, paraquat, and propachlor) on the short-circuit current, whose value gives an estimate of the net ion transport taking place across isolated skin. Glyphosate and paraquat treatment produced a modest increase in short-circuit current, corresponding to 2.6±0.7 and 4.6±0.8 μA·cm^?2, whereas the other substances had a more sustained effect, ranging from 9.1±0.6 (propachlor) to 14.8±0.9 μA·cm^?2 (captan), which is mainly attributable to an increase in the Na⁺ absorption, and, to a lesser extent, Cl^? secretion. The increase in short-circuit current after pesticide treatment, was partially abolished by AF12198, indomethacin, SC58125, SQ 22536, and W7; these results suggest that pesticides, independently from their chemical structure, induce the release of interleukin-1, which triggers the activity of cyclooxygenase-2, whose products, via a concentration in intracellular cAMP and Ca²⁺ concentration, increase Na⁺ absorption. The resulting Na⁺ disequilibrium must be compensated for by other epithelia, with the only consequence being the dissipation of energy. However, our results are important because they indicate that pesticides interact with the basic cellular machinery, which is responsible for the myriad of biological functions of different cell types.     

New thiol adsorbent grafted on silica gel: synthesis,characterization and employment for heavy metal adsorptions

Silica gel surface has been modified in two reaction steps: (i) the silylating agent 3-mercaptopropyltrimetoxysilane was firstly immobilized to give a surface Sil-SH and (ii) this precursor incorporated an ethylene sulfide molecule to obtain the surface denoted Sil-SSH. This material was characterized by elemental analysis, IR spectroscopy, thermogravimetry, solid state 13C and 29Si NMR, and surface area measurement. These materials were employed as adsorbents for divalent heavy cations from aqueous solutions at room temperature and the isotherms were adjusted to a modified Langmuir equation. The maxima number of moles adsorbed were 1.0, 1.5, 1.6, 2.2, 2.4 and 3.3 mmol g(-1) for Co, Cu, Ni, Cd, Pb, and Hg, respectively.     

Land take and food security: assessment of land take on the agricultural production in Europe

Soil is a multifunctional, non-renewable natural resource for Europe as clearly expressed in the European Union (EU) Thematic Strategy for Soil Protection (COM (2006)231). Soil carries out multiple functions, including the support of food production. Urban development and its associated land take poses a major threat to soil and could have significant effects on agricultural production. This paper aims to evaluate the potential productivity losses in European agriculture due to land-take processes between 1990 and 2006. Agricultural land take was calculated using CORINE Land Cover maps of 1990, 2000 and 2006. For 21 of the 27 EU member states, agricultural land take was computed to be 752,973 ha for 1990–2000 and 436,095 ha for 2000–2006, representing 70.8% and 53.5%, respectively, of the total EU land take for these periods. The impact of this land take on the production capabilities of the agricultural sector for the period 1990–2006 for 19 of the 21 states was estimated to be equivalent to a loss of more than six million tonnes of wheat. The paper demonstrates that Europe's intense urbanisation has a direct impact on its capability to produce food.     

Screening ecological risk assessment for the benthic community in the Venice lagoon (Italy)

According to the risk hypothesis: the sediment as source of potential risk for the benthic community, an Ecological Risk Assessment (ERA) based on the quotient method was undertaken. The exposure of the benthic community to different classes of pollutants (metals, chlorinated organic compounds and polynuclear aromatic hydrocarbons) was inferred by estimating the pollutant stocks in the top 15-cm sediment of the whole Venice lagoon, after application of geostatistic techniques. The risk was calculated by comparing the sediment exposure profiles with the ecotoxicological benchmarks for benthic organisms. Kriging based maps of the spatial distribution of the estimated risk for the benthic community over the whole lagoon were obtained. The highest risk, found in the areas nearest to the sources of contamination (e.g., the industrial district of Porto Marghera and the river mouths), was posed by mercury (40% of the sampling stations showed exposure levels higher than the Probable Effect Level), arsenic and nickel (75% of the sampling stations exceeded the Threshold Effect Level).