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Does waterborne citalopram affect the aggressive and sexual behaviour of rainbow trout and guppy?

Citalopram is one of several selective serotonin reuptake inhibitors (SSRIs) commonly found in treated sewage effluents. Accordingly, there are concerns about possible adverse effects of SSRIs on aquatic organisms, particularly behavioural effects similar to those associated with SSRI use in humans. Rainbow trout fry and adult male guppies were therefore exposed to waterborne citalopram, ranging from environmentally relevant to high concentrations (1, 10, 100 μg/L) for 3-7 days. Under these experimental conditions citalopram does not appear to cause significant effects on aggression in rainbow trout fry or on sexual behaviour in male guppies. This may be explained by a relatively low uptake of citalopram from water to fish.     

Separation and characterization of food macromolecules using field-flow fractionation: A review

Recent years have seen an increasing interest in asymmetrical flow field-flow fractionation (AF4) as a method for the fractionation and characterization of macromolecules and colloidal particles. In this paper utilization of AF4 in food applications is reviewed. Instrumental considerations are discussed as well as which properties can be assessed by AF4 and adequate detection systems. Furthermore, published literature on analysis of food macromolecules with AF4 is critically reviewed.     

Storage temperature affects distribution of carbon, VFA, ammonia, phosphorus, copper and zinc in raw pig slurry and its separated liquid fraction

Chemical-mechanical separation of pig slurry into a solid fraction rich in dry matter, P, Cu and Zn and a liquid fraction rich in inorganic N but poor in dry matter may allow farmers to manage surplus slurry by exporting the solid fraction to regions with no nutrient surplus. Pig slurry can be applied to arable land only in certain periods during the year, so it is commonly stored prior to field application. This study investigated the effect of storage duration and temperature on chemical characteristics and P, Cu and Zn distribution between particle size classes of raw slurry and its liquid separation fraction. Dry matter, VFA, total N and ammonium content of both slurry products decreased during storage and were affected by temperature, showing higher losses at higher storage temperatures. In both products, total P, Cu and Zn concentrations were not significantly affected by storage duration or temperature. Particle size distribution was affected by slurry separation, storage duration and temperature. In raw slurry, particles larger than 1 mm decreased, whereas particles 250 μm-1 mm increased. The liquid fraction produced was free of particles >500 μm, with the highest proportions of P, Cu and Zn in the smallest particle size class (<25 μm). The proportion of particles <25 μm increased when the liquid fraction was stored at 5 °C, but decreased at 25 °C. Regardless of temperature, distribution of P, Cu and Zn over particle size classes followed a similar pattern to dry matter.     

Effect of filler on low temperature physical hardening of bitumen

Laboratory investigations of low temperature physical hardening of bitumen using a Bending Beam Rheometer (BBR) are described. The study encompasses five bitumens, three conditions with regard to additives and three testing temperatures (−15, −25 and −30°C). As additives, two fillers, hydrated lime and calcium carbonate, were used. The effect of the fillers on the isothermal low temperature hardening was evaluated with the aid of a physical hardening index. The viscoelastic nature of the bitumens and bitumen/filler mixtures was investigated utilising the Burger model, and the Burger parameters were used to calculate dissipation energy ratios (dissipated energy over stored energy) in each BBR test. The results obtained did not indicate any significant effect of the fillers on low temperature physical hardening. Analyses of the dissipation energy ratio showed a considerable capacity for energy dissipation, even at a temperature as low as −30°C. With few exceptions, more energy was dissipated than stored during a BBR test. It appears that the dissipation energy ratio is not necessarily related to the stiffness of the binder.     

The variation of bedrock quality with increasing ductile deformation

Most of the rocks in Precambrian shield areas have experienced a complex structural and metamorphic evolution, processes which have a strong influence on the bedrock quality. This may vary both on a local and regional scale. The main object of this investigation was to study the variation of the rock mechanical properties at various stages of ductile deformation of an originally isotropic rock. Ten samples from five different localities northeast of Lake Vänern (south central Sweden) were tested, including studded tyre and LA tests, uniaxial compressive strength (UCS), ultrasonic velocity, electrical resistivity, Swedish impact value and Swedish flakiness index as well as petrographic and chemical analyses. This study highlights the importance of considering all possible variations in bedrock before classification, and of undertaking regional investigations.     

Regional valuation of infrastructure and transport attributes for Swedish road freight

Is it possible to identify regional differences among shippers in their valuation of infrastructure improvements? In this study, the question is analysed using a random utility approach, where parameters are estimated by a logit model. Data consist of a Swedish stated-preference study from 1992. The results indicate that regional differences exist, but that a considerable heterogeneity in the empirical data means that in some cases the results are not robust. However, when industrial mix, shipping distance, and goods values are held constant, the analysis still indicates the existence of regional differences. Independently of the limitations in the results, the study has implications for any infrastructure benefit analysis where parameters from spatial averages are used. The results are based on short-term decisions, and one should recognise that parameters may vary in the mid- and long-term. Received: May 1999/Accepted: March 2001     

Effect of specimen size and loading conditions on spalling of concrete

Different qualities of concrete have been fire tested using different geometries of the specimens as well as different load levels and load configurations. The main objective with the study was to examine a test methodology consisting of a full‐scale test and different small scale‐tests for determining the probability of spalling and the amount of spalling of fire exposed concrete structures. A reference specimen was defined as a one‐sided fire exposed slab with the dimensions 1800 × 1200 mm² giving an exposed area of 1500 × 1200 mm². A number of concrete qualities with different probabilities for spalling, were tested using the reference specimen. These tests showed that the reference specimens worked well giving the expected test results. Small specimens were manufactured in different shapes with the same concrete as the one used in the reference tests. These small specimens were tested either at the same time as the reference specimens in the large furnace or afterwards on a small‐scale furnace where the fire exposed surface was 450 × 360 mm². The test results clearly show the increased probability and the increased amount of spalling by using external compressive loading. The results also show that by using pre‐stress through bars or wires the load can be lost due to heating of the bars/wires which results in a decreased amount of spalling. The boundary of the specimen also affects the amount of spalling. The spalling around the edges was in all tests less than the spalling on the central parts of the exposed area. It could also be noted that the spalling did not pass completely through any of the specimens. The reason for this is probably that the water/vapour could migrate out from the unexposed surface of the specimen. Copyright © 2006 John Wiley & Sons, Ltd.