Ovarian fluid of receptive females enhances sperm velocity

The females of several internal fertilizers are able to store sperm for a long time, reducing the risk of sperm limitation. However, it also means that males can attempt to mate outside females’ receptive period, potentially increasing the level of sperm competition and exacerbating sexual conflict over mating. The guppy (Poecilia reticulata), an internally fertilizing fish, is a model system of such competition and conflict. Female guppies accept courtship and mate consensually only during receptive periods of the ovarian cycle but receive approximately one (mostly forced) mating attempt per minute both during and outside their sexually receptive phase. In addition, females can store viable sperm for months. We expected that guppy females would disfavour sperm received during their unreceptive period, possibly by modulating the quality and/or quantity of the components present in the ovarian fluid (OF) over the breeding cycle. Ovarian fluid has been shown to affect sperm velocity, a determinant of sperm competition success in this and other fishes. We found that in vitro sperm velocity is slower in OF collected from unreceptive females than in OF from receptive females. Visual stimulation with a potential partner prior to collection did not significantly affect in vitro sperm velocity. These results suggest that sperm received by unreceptive females may be disfavoured as sperm velocity likely affects the migration process and the number of sperm that reach storage sites.     

A review of studies applying environmental impact assessment methods on fruit production systems

Although many aspects of environmental accounting methodologies in food production have already been investigated, the application of environmental indicators in the fruit sector is still rare and no consensus can be found on the preferred method. On the contrary, widely diverging approaches have been taken to several aspects of the analyses, such as data collection, handling of scaling issues, and goal and scope definition. This paper reviews studies assessing the sustainability or environmental impacts of fruit production under different conditions and identifies aspects of fruit production that are of environmental importance. Four environmental assessment methods which may be applied to assess fruit production systems are evaluated, namely Life Cycle Assessment, Ecological Footprint Analysis, Emergy Analysis and Energy Balance. In the 22 peer-reviewed journal articles and two conference articles applying one of these methods in the fruit sector that were included in this review, a total of 26 applications of environmental impact assessment methods are described. These applications differ concerning e.g. overall objective, set of environmental issues considered, definition of system boundaries and calculation algorithms. Due to the relatively high variability in study cases and approaches, it was not possible to identify any one method as being better than the others. However, remarks on methodologies and suggestions for standardisation are given and the environmental burdens of fruit systems are highlighted.     

The Viareggio LPG accident: Lessons learnt

On June 29th, 2009 the derailment of a freight train carrying 14 LPG (Liquefied Petroleum Gas) tank-cars near Viareggio, in Italy, caused a massive LPG release. A gas cloud formed and ignited triggering a flash-fire that resulted in 31 fatalities and in extended damages to residential buildings around the railway line. The vulnerability of the area impacted by the flash-fire emerged as the main factor in determining the severity of the final consequences. Important lessons learnt from the accident concern the need of specific regulations and the possible implementation of safety devices for tank-cars carrying LPG and other liquefied gases under pressure. Integrated tools for consequence assessment of heavy gas releases in urban areas may contribute to robust decision making for mitigation and emergency planning.     

Seasonal evolution of gas-phase PCB concentrations in the Venice Lagoon area

The concentrations of gas-phase PCBs were measured from March 2002 to June 2003 at two sites of the Venice Lagoon and at one site of the Euganei hills. The aims of this study were to evaluate the various gas-phase PCB sources, the spatial and temporal variability of PCB concentrations in the gas-phase that enter the Venice Lagoon atmosphere and the influence of the air temperature on PCB trends. The highest annual average concentration of summation PCBs was observed at the station directly influenced by "urban" sources with values about 3 and 1.5 times higher compared to the concentrations found at the stations where "marine" sources and "not subjected to direct local sources" were respectively sampled from. The temporal trends of summation PCBs concentrations were similar at the three sampling stations corresponding to seasonal temperature changes. Greater concentrations occurred in the summer and first autumn months while the lower ones occurred in late autumn and winter. The temperature dependences were investigated using plots of the natural logarithm of the summation PCBs concentrations vs. reciprocal mean temperatures.     

Review of dynamical models for external dose calculations based on Monte Carlo simulations in urbanised areas

After an accidental release of radionuclides to the inhabited environment the external gamma irradiation from deposited radioactivity contributes significantly to the radiation exposure of the population for extended periods. For evaluating this exposure pathway, three main model requirements are needed: (i) to calculate the air kerma value per photon emitted per unit source area, based on Monte Carlo (MC) simulations; (ii) to describe the distribution and dynamics of radionuclides on the diverse urban surfaces; and (iii) to combine all these elements in a relevant urban model to calculate the resulting doses according to the actual scenario. This paper provides an overview about the different approaches to calculate photon transport in urban areas and about several dose calculation codes published. Two types of Monte Carlo simulations are presented using the global and the local approaches of photon transport. Moreover, two different philosophies of the dose calculation, the "location factor method" and a combination of relative contamination of surfaces with air kerma values are described. The main features of six codes (ECOSYS, EDEM2M, EXPURT, PARATI, TEMAS, URGENT) are highlighted together with a short model-model features intercomparison.     

Determination of strontium-90 in deer bones by liquid scintillation spectrometry after separation on Sr-specific ion exchange columns

The activity concentration of (90)Sr was determined in several deer bones from Austria. Strontium specific ion exchange columns with 4',4'(5')-di-t-butylcyclohexane-18-crown-6 from Eichrom Industries, Inc. were used for separation. The yield of the chemical procedure was quantified with AAS. Directly after column separation, the solution containing (90)Sr was mixed with the scintillation cocktail HiSafe III and measured by liquid scintillation counting. Prevention of (210)Pb contamination and reusability of the separation columns was investigated as well as the activity distribution within the bones. Results were compared with pre-Chernobyl measurements in Austria; a correlation between activity concentration of (90)Sr and site altitude was found.     

Spiking organic chemicals onto sediments for ecotoxicological analyses: an overview of methods and procedures

Environmental Science and Pollution Research - Laboratory testing with spiked sediments with organic contaminants is a valuable tool for ecotoxicologists to study specific processes such as effects...     

Response of atmospheric deposition and surface water chemistry to the COVID-19 lockdown in an alpine area

Environmental Science and Pollution Research - The effects of the COVID-19 lockdown on deposition and surface water chemistry were investigated in an area south of the Alps. Long-term data provided...