Electrocution of pigs.

Electrocution was considered to have caused 28 deaths in a house of 109 fat pigs. Post mortem examination showed haemorrhages at varying sites. Another 35, showing varying degrees of paralysis, were sent for slaughter. In most of these the pelvis was fractured and in some the vertebral column in the lumbosacral region. Twenty eight were condemned, 26 of them because of haemorrhages and because of spoilage associated with rupture of the urinary bladder.     

An astronomical 2175 angstrom feature in interplanetary dust particles

The 2175 angstrom extinction feature is the strongest (visible-ultraviolet) spectral signature of dust in the interstellar medium. Forty years after its discovery, the origin of the feature and the nature of the carrier(s) remain controversial. Using a transmission electron microscope, we detected a 5.7-electron volt (2175 angstrom) feature in interstellar grains embedded within interplanetary dust particles (IDPs). The carriers are organic carbon and amorphous silicates that are abundant in IDPs and in the interstellar medium. These multiple carriers may explain the enigmatic invariant central wavelength and variable bandwidth of the astronomical 2175 angstrom feature.     

Effect of sodicity and salinity on disaggregation and tensile strength of an Alfisol under different cropping systems

The influence of electrolyte concentration (EC) and sodium adsorption ratio (SAR) on the tensile strength and aggregate stability via flocculation and dispersion behaviour of an Alfisol varying in organic carbon content due to different cropping systems was assessed using a split-split plot experiment involving eight soils, three levels of EC and seven levels of SAR.

Generally, at a given SAR value, mean weight diameter (MWD) increased with organic matter status of the soil in the following order: virgin pasture>wheat>wheat-fallow. As MWD decreased, the amount of dispersible clay increased at a given SAR indicating that more surfaces exposed due to slaking of aggregates led to more clay dispersion. Statistical analysis of changes in tensile strength with various factors showed that an increase in organic matter decreased the magnitude of changes in strength induced by sodicity because organic matter tends to increase aggregate stability (higher MWD). While individual soils had significant relationships between the tensile strength of the aggregates and the amount of spontaneously dispersible clay, this relationship was poor when the results of all soils were pooled together. The amounts of dispersible clay from dry aggregates were higher than from wet aggregates and dispersive breakdown of the aggregates of sodic soils occured irrespective of the mode of wetting. The most important factor in determining the soil strength was the amount of clay dispersed during wet-sieving analysis followed by MWD.     

Effectiveness of five small Philippines’ coral reef reserves for fish populations depends on site-specific factors, particularly enforcement history

Community-managed, no-take marine reserves are increasingly promoted as a simple, precautionary measure to conserve biodiversity and sustain coral reef fisheries. However, we need to demonstrate the effects of such reserves to those affected by the loss of potential fishing grounds and the wider scientific community. We surveyed changes in fish communities in five small marine reserves in the central Philippines and three distant Control sites over seven years. We conducted underwater visual censuses of 53 fish families within the reserve (Inside), with a kilometre of the boundary (Outside) and at Control sites. We found significant differences between fish communities Inside and Outside the reserve only at the two sites with strictest compliance with fishing prohibition, while there were significant differences to distant Control sites in all cases. The strongest responses to reserve protection were found in predatory fishes (groupers and breams) and in butterflyfish. Other abundant fish families showed weak effects of protection. For all taxa analysed, we found significant effects of reserve Site and Site × Treatment interactions. The detection of fish responses to reserves is complicated by potential spillover effects, site-specific factors, particularly compliance, and the difficulty of identifying appropriate control areas.     

Investigations into the toxicity of Echium plantagineum in sheep: 1. Field grazing experiments

A field grazing trial was undertaken to monitor the health and production of crossbred sheep grazing pasture where Echium plantagineum constituted a considerable proportion of the available forage. The trial, conducted for 19 months over successive grazing seasons, demonstrated a significant difference in production, with sheep on the E. plantagineum pasture being lighter and growing less wool compared with sheep on Echium-free pasture. No mortalities involving pyrrolizidine alkaloid poisoning were recorded in sheep grazing E. plantagineum, although there was histological evidence of moderately severe liver damage associated with high liver copper concentrations in at least one sheep following the grazing of large quantities of the plant.