Effects of prenatal yolk androgens on armaments and ornaments of the ring-necked pheasant

Mothers may profoundly affect offspring phenotype and performance by adjusting egg components, including steroid hormones. We studied the effects of elevated prenatal testosterone (T) exposure in the ring-necked pheasant on the expression of a suite of male and female traits, including perinatal response to stress, immune response, growth, and secondary sexual traits. Prenatal T levels were increased by injecting the yolk of unincubated eggs with physiological doses of the hormone. Yolk T injection resulted in a reduced length of male tarsal spurs, a trait which positively predicts male success in intra- and intersexual selection and viability, whereas no direct effect on male wattle characteristics or plumage traits of either sex was observed. Female spur length was also negatively affected by T, but to a lesser extent than in males. In addition, the covariation between male secondary sexual traits, which are reliable quality indicators, differed between T and control males, suggesting that the manipulation may have altered the assessment of overall male quality by other males and females. In conclusion, the negative effects of elevated yolk T on spur length, a trait which positively predicts male fitness, coupled with the lack of effects on growth or other traits in both sexes, provided limited evidence for mothers being subjected to a trade-off between positive and negative consequences of yolk T deposition on offspring traits and suggest that directional selection for reduced yolk T levels may occur in the ring-necked pheasant.     

Characterization of dissolved organic matter from saline soils by fluorescence spectroscopy

In this paper hydrophilic (HI) and hydrophobic (HO) fractions of dissolved organic matter (DOM) extracted from soils at different degrees of salinisation were characterised by means of fluorescence spectroscopy in the emission, excitation and synchronous-scan modes. Results provided evidence of the different chemical nature of DOM fractions and allowed to distinguish hydrophilic and hydrophobic fractions extracted from the same soil substrate. The strong decrease in fluorescence intensity observed with the increasing salinity of the soils can be utilised to obtain information on the salinity level of different soil substrates by comparison of spectral fluorescence intensities.     

Hiding in Plain Sight? It’s Time to Investigate Other Possible Transmission Routes for Hepatitis E Virus (HEV) in Developed Countries

Historically in developed countries, reported hepatitis E cases were typically travellers returning from countries where hepatitis E virus (HEV) is endemic, but now there are increasing numbers of non-travel-related (“autochthonous”) cases being reported. Data for HEV in New Zealand remain limited and the transmission routes unproven. We critically reviewed the scientific evidence supporting HEV transmission routes in other developed countries to inform how people in New Zealand may be exposed to this virus. A substantial body of indirect evidence shows domesticated pigs are a source of zoonotic human HEV infection, but there is an information bias towards this established reservoir. The increasing range of animals in which HEV has been detected makes it important to consider other possible animal reservoirs of HEV genotypes that can or could infect humans. Foodborne transmission of HEV from swine and deer products has been proven, and a large body of indirect evidence (e.g. food surveys, epidemiological studies and phylogenetic analyses) support pig products as vehicles of HEV infection. Scarce data from other foods suggest we are neglecting other potential sources of foodborne HEV infection. Moreover, other transmission routes are scarcely investigated in developed countries; the role of infected food handlers, person-to-person transmission via the faecal–oral route, and waterborne transmission from recreational contact or drinking untreated or inadequately treated water. People have become symptomatic after receiving transfusions of HEV-contaminated blood, but it is unclear how important this is in the overall hepatitis E disease burden. There is need for broader research efforts to support establishing risk-based controls.     

Inactivation and injury assessment of Escherichia coli during solar and photocatalytic disinfection in LDPE bags

Solar disinfection (SODIS) of Escherichia coli suspensions in low-density polyethylene bag reactors was investigated as a low-cost disinfection method suitable for application in developing countries. The efficiency of a range of SODIS reactor configurations was examined (single skin (SS), double skin, black-backed single skin, silver-backed single skin (SBSS) and composite-backed single skin) using E. coli suspended in model and real surface water. Titanium dioxide was added to the reactors to improve the efficiency of the SODIS process. The effect of turbidity was also assessed. In addition to viable counts, E. coli injury was characterised through spread-plate analysis using selective and non-selective media. The optimal reactor configuration was determined to be the SBSS bag (t₅₀ = 9.0 min) demonstrating the importance of UVA photons, as opposed to infrared in the SODIS disinfection mechanism. Complete inactivation (6.5-log) was achieved in the presence of turbidity (50 NTU) using the SBSS bag within 180 min simulated solar exposure. The addition of titanium dioxide (0.025 g L⁻¹) significantly enhanced E. coli inactivation in the SS reactor, with 6-log inactivation observed within 90 min simulated solar exposure. During the early stages of both SODIS and photocatalytic disinfection, injured E. coli were detected; however, irreversible injury was caused and re-growth was not observed. Experiments under solar conditions were undertaken with total inactivation (6.5-log) observed in the SS reactor within 240 min, incomplete inactivation (4-log) was observed in SODIS bottles exposed to the same solar conditions.     

Development and application of a regional-scale atmospheric mercury model based on WRF/Chem: a Mediterranean area investigation

The emission, transport, deposition and eventual fate of mercury (Hg) in the Mediterranean area has been studied using a modified version of the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem). This model version has been developed specifically with the aim to simulate the atmospheric processes determining atmospheric Hg emissions, concentrations and deposition online at high spatial resolution. For this purpose, the gas phase chemistry of Hg and a parametrised representation of atmospheric Hg aqueous chemistry have been added to the regional acid deposition model version 2 chemical mechanism in WRF/Chem. Anthropogenic mercury emissions from the Arctic Monitoring and Assessment Programme included in the emissions preprocessor, mercury evasion from the sea surface and Hg released from biomass burning have also been included. Dry and wet deposition processes for Hg have been implemented. The model has been tested for the whole of 2009 using measurements of total gaseous mercury from the European Monitoring and Evaluation Programme monitoring network. Speciated measurement data of atmospheric elemental Hg, gaseous oxidised Hg and Hg associated with particulate matter, from a Mediterranean oceanographic campaign (June 2009), has permitted the model’s ability to simulate the atmospheric redox chemistry of Hg to be assessed. The model results highlight the importance of both the boundary conditions employed and the accuracy of the mercury speciation in the emission database. The model has permitted the reevaluation of the deposition to, and the emission from, the Mediterranean Sea. In light of the well-known high concentrations of methylmercury in a number of Mediterranean fish species, this information is important in establishing the mass balance of Hg for the Mediterranean Sea. The model results support the idea that the Mediterranean Sea is a net source of Hg to the atmosphere and suggest that the net flux is ≈30 Mg year^?1 of elemental Hg.     

Self-potential monitoring of a crude oil-contaminated site (Trecate,Italy)

We present a multidisciplinary approach for characterization of a crude oil-contaminated site (Trecate, Italy), integrating geophysical data, such as subsoil electrical potential (in millivolts) and electrical resistivity (in ohm meters) distribution, with hydrogeological and bio-chemical data. Self-potential measurements have been evaluated together with active geoelectrical measurements and hydrological information, to provide spatial and temporal information about the self-potential sources and their possible correlations with the contamination state of the subsoil. Three self-potential surveys (March 2010, October 2010, and March 2011) were conducted at the site, both in the contaminated and uncontaminated regions. The obtained self-potential maps show large time-lapse differences in correspondence of the contaminated area, with positive electrical potential values (up to 50 mV) in spring surveys and an electrical potential dipolar distribution in October (2010) survey (amplitude from ?15 to 25 mV). To understand the origin of the measured self-potential signals, a model using vertical dipolar electrical sources was built, taking into account the electrical resistivity distribution deduced from electrical resistivity tomography. The self-potential source identification allows the Trecate contamination state to be better delineated. In particular, two self-potential contributions are superimposed: the electrokinetic mechanism is predominant in spring, while the redox mechanism represents the most important contribution in autumn.     

Mercury in the Mediterranean,part I: spatial and temporal trends

The present paper provides an overview of mercury studies performed in the Mediterranean Sea region in the framework of several research projects funded by the European Commission and on-going national programmes carried out during the last 15 years. These studies investigated the temporal and spatial distribution of mercury species in air, in the water column and sediments, and the transport mechanisms connecting them. It was found that atmospheric concentrations of Hg compounds, particularly oxidised Hg species observed at five coastal sites in the Mediterranean Sea Basin, are significantly higher compared with those recorded at five coastal sites distributed across N Europe, most probably due to natural emissions. Hg levels in water are comparable to other oceans. Anthropogenic and natural point sources show locally limited enrichments, while natural diffusive sources influence Hg speciation over larger areas. Results and statistic comparison of mercury species concentrations within Mediterranean compartments will be presented and discussed.     

Influence of salinity and temperature on the activity of biosurfactants by polychaete-associated isolates

Influence of different parameters on biosurfactant (BS) activity was carried out on strains that were isolated from the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum and additional 30 strains that were previously identified as potential BS producers from crude oil enrichments of the same polychaete specimens. The selection of BS-producing strains from polychaete natural samples was carried out by using standard screening tests. The BS activity by each isolate was evaluated for the effect of salinity and temperature on emulsion production and surface tension reduction, during incubation in mineral medium supplemented with tetradecane or diesel oil. All isolates showed a similar time course of BS activity, and the latter was more influenced by salinity rather than temperature. Some of the BS producers belonged to genera that have not (i.e. Citricoccus, Cellulophaga, Tenacibaculum and Maribacter) or have poorly been (Psychrobacter, Vibrio, and Pseudoalteromonas) reported as able to produce BSs. This is remarkable as some of them have previously been detected in hydrocarbon-enriched samples. Results confirm that filter-feeding polychaetes are an efficient source for the isolation of BS producers.     

Mercury in the Mediterranean. Part 2: processes and mass balance

Mass balance of contaminants can provide useful information on the processes that influence their concentrations in various environmental compartments. The most important sources, sinks and the equilibrium or non-equilibrium state of the contaminant in individual environmental compartments can also be identified. Using the latest mercury speciation data, the results of numerical models and the results of recent studies on mercury transport and transformation processes in the marine environment, we have re-evaluated the total mercury (HgT) mass balance in the Mediterranean Sea. New calculations have been performed employing three distinct marine layers: the surface layer, the thermocline and the deep sea. New transport mechanisms, deep water formation and density-driven sinking and upwelling, were included in the mass balance calculations. The most recent data have even enabled the calculation of an approximate methylmercury (MeHg) mass balance. HgT is well balanced in the entire Mediterranean, and the discrepancies between inputs and outputs in individual layers do not exceed 20 %. The MeHg balance shows larger discrepancies between gains and losses due to measurement uncertainties and gaps in our knowledge of Hg species transformation processes. Nonetheless, the main sources and sinks of HgT (deposition and evasion) and MeHg (fluxes from sediment, outflow through the Gibraltar Strait) are in accordance with previous studies on mercury in the Mediterranean Basin. Mercury in the Mediterranean fish harvest is the second largest MeHg sink; about 300 kg of this toxic substance is consumed annually with sea food.