Trophic effects of fishing southern rock lobster Jasus edwardsii shown by combined fatty acid and stable isotope analyses

The southern rock lobster Jasus edwardsii is a commercial species that has benefited from the complete protection offered by no-take reserves, with higher abundances and larger animals recorded in reserves than in adjacent fished areas. What remains unclear is whether there is any change in the diet of lobsters in reserves, for example, as a result of increased intraspecific competition for food. We used combined chemical tracers to examine the diet of lobsters in fished and reserve areas in 2 bioregions in eastern Tasmania. δ15N values of lobsters were richer in fished than in reserve areas, indicating that lobsters eat a greater proportion of food items from higher trophic levels in fished areas. Mixing models suggest that ascidians, sea urchins and the turbinid gastropod were all important food sources for lobsters, but the importance of these food items differed between bioregions. This spatial variability may suggest that the small size of the reserve in one bioregion is inadequate at ensuring the diet of lobsters is protected from fishing pressure. Fatty acid profiles of lobsters supported the importance of these food sources to lobsters. Differences between bioregions, or inside and outside of reserves, were not apparent using fatty acids. The present study highlights that lobster fishing has the capacity to alter the trophic status of prey for generalist predators and suggests that fatty acid analyses may be limited in detecting changes in the dietary composition of such generalist feeders.

(Joyful pop-rock) heaven (mandolin rock)

A short and uplifting composition that is joyful in tone. Heaven is a track that is predominantly played on a real electro-acoustic mandolin - a versatile and sweet sounding instrument that punches above its weight to create a modern pop rock sound. The other sounds are a sampled bass, drums and a synth pad.

(Joyful pop-rock) heaven (mandolin rock) LOOP

A short and uplifting composition (looped) that is joyful in tone. Heaven is a track that is predominantly played on a real electro-acoustic mandolin - a versatile and sweet sounding instrument that punches above its weight to create a modern pop rock sound. The other sounds are a sampled bass, drums and a synth pad.

(Joyful pop-rock) heaven (mandolin rock) no intro hits

A short and uplifting composition that is joyful in tone. Heaven is a track that is predominantly played on a real electro-acoustic mandolin - a versatile and sweet sounding instrument that punches above its weight to create a modern pop rock sound. The other sounds are a sampled bass, drums and a synth pad.

Ambieerie rock stinger

A rock stinger intro.

Ambient cinematic guitar rock

A short instrumental that is ambient in style and would suit cinematic types of projects. Guitar, bass, drums and a synth pad feature in this composition.

Comparisons between two empirical yield criteria for rock masses

In general, rock masses are inhomogeneous, discontinuous media composed of rock material and naturally occurring discontinuities such as joints, fractures and bedding planes. Because of these features, the strength of rock masses is notoriously difficult to assess. Nonetheless, many criteria have been proposed for estimating rock mass strength. Based on the finite element upper and lower bound limit analysis methods, this study examined two empirical yield criteria for rock masses, the Hoek-Brown failure criterion (2002) and the Douglas criterion (2002). The comparisons showed that very different results may be obtained using the same input parameters. Therefore, it is interesting to discuss the source of these differences.

Rock slope risk analysis based on non-linear failure criterion

The probability of failure of a rock slope is generally estimated by using the Limit Equilibrium Method (LEM) in conjunction with a reliability analysis. Although the LEM is relatively simple and time efficient, recent studies have indicated that using the LEM may overestimate the factor of safety by 21%, when based on a non-linear failure criterion. Fortunately, the solutions presented by Li et al. (2008, 2009) can provide more accurate evaluations for rock slope stability as the numerical upper and lower bound limit analysis methods (2002a, 2002b, 2005) were employed. The advantages of these methods are used in this study to assess the rock slope probability of failure. The motivation is that with more accurate methods to evaluate the factor of safety, more economic designs can be performed.

Bass line rock loop 01

Bass Line Rock Loop 01 is a simple bass, electric guitar and drum loop in the style of Rock Pop.

Bass line rock loop 02

Bass Line Rock Loop 02 is a simple bass, electric guitar, synth and drum loop in the style of Rock Pop.