The Anthropocene: an Australasian perspective and survey.

In 2000, Crutzen and Stoermer suggested that the Holocene (the geological period of time since 11,700 years ago: Walker et al., 2009) had finished and that humanity had now entered the “Anthropocene”. As summarised by Steffen et al. (2011) and Wolfe et al. (2013), these scientists were referring to the Anthropocene as the interval of demonstrable human alteration of global biogeochemical cycles, beginning subtly in the late 18th Century following James Watt’s invention of the coal-fired steam engine, and accelerating markedly in the mid-20th Century (called “The Great Acceleration”)

Spin asymmetries for electron-thallium scattering calculated with the relativistic convergentclose-coupling method

Spin asymmetries for elastic and inelastic scattering of electrons from thallium are presented. Thalliumis a heavy target (Z 81) and the spin asymmetries can be caused by relativistic effects (spin-orbit interactions) in addition to exchange effects

The application of science and technology development in shaping current and future aquaculture production systems

Aquaculture development over the past 50 years has been facilitated largely by the application of science and the introduction of new technologies. Although aquaculture is a very diverse sector in products, production systems and business structures, almost every activity has benefitted from scientific advances. However, the impact of technological progress is most clearly seen where there has also been substantial industrial consolidation. This has provided greater capital resources for investment and a more attractive market for suppliers of innovations to target. It has also encouraged consolidation of research capacity and stronger articulation between private and publicly funded research efforts. Further development along current trajectories is possible through advances in genomics, information technology, materials science and other areas. However, there may also be substantial disruptions if, for instance, energy becomes much more expensive, or large mono-cultures are impacted by climate change. Substantial change could also be driven by policies that aim to bring realistic external costs of environmental services into company accounts. Research into more resilient aquaculture systems that comply more with ecological than financial accounting principles is under way, but will require substantial development to meet the challenges of rising food needs and social aspirations.Prepared as background for the UK Government Foresight Project on Global Food and Farming Future

Accommodation to hyperpolarization of human axons assessed in the frequency domain

Human axonsin vivowere subjected to subthreshold currents with a threshold-"ZAP" profile (Impedance [ Z: ] A: mplitude P: rofile) to allow the use of frequency domain techniques to determine the propensity for resonant behavior, and to clarify the relative contributions of different ion channels to their low-frequency responsiveness. Twenty-four studies were performed on the motor and sensory axons in 6 subjects. The response to oscillatory currents was tested between 'DC' and 16 Hz. A resonant peak at ~2 to 2.5 Hz was found in the response of hyperpolarized axons, but there was only a small broad response in axons at resting membrane potential (RMP). A mathematical model of axonal excitability developed using DC pulses provided a good fit to the frequency response for human axons, and indicated that the hyperpolarization-activated currentIh, and the slow potassium currentIKsare principally responsible for the resonance. However the results indicate that if axons are hyperpolarized more than -60% of resting threshold, the only conductances that are appreciably active areIhand the leak conductance - i.e., that the activity of these conductances can be studiedin vivovirtually in isolation at hyperpolarized membrane potentials. Given that the leak conductance dampens resonance it is suggested that the -60% hyperpolarization used here is optimal forIh As expected differences between the frequency responses of motor and sensory axons were present and best explained by reduced GKs, up-modulation ofIhand increased persistent Na(+)current,INaP(due to depolarization of RMP) in sensory axons