Rotations, Risk and Reward: Farming system choice on the Eyre Peninsula of South Australia

A farming systems and rotations trial was conducted at Minnipa on the Eyre Peninsula of South Australia between 1995 and 2001. The results have been presented to local farmers as simple gross margin comparisons (with a relatively low value for the pasture phase if present) in extension publications. The results are reassessed in terms of increased livestock return, and allowing for permanent/family labour and machinery overheads. The relative risk vs return is also considered to explain the acceptance of the research by local farmers.Farm Management, Land Economics/Use,

Advancing imaging technologies for patients with spinal pain : with a focus on whiplash injury

Background: Radiological observations of soft-tissue changes that may relate to clinical symptoms in patients with traumatic and non-traumatic spinal disorders are highly controversial. Studies are often of poor quality and findings are inconsistent. A plethora of evidence suggests some pathoanatomical findings from traditional imaging applications are common in asymptomatic participants across the life span, which further questions the diagnostic, prognostic, and theranostic value of traditional imaging. Although we do not dispute the limited evidence for the clinical importance of most imaging findings, we contend that the disparate findings across studies may in part be due to limitations in the approaches used in assessment and analysis of imaging findings. Purpose: This clinical commentary aimed to (1) briefly detail available imaging guidelines, (2) detail research-based evidence around the clinical use of findings from advanced, but available, imaging applications (eg, fat and water magnetic resonance imaging and magnetization transfer imaging), and (3) introduce how evolving imaging technologies may improve our mechanistic understanding of pain and disability, leading to improved treatments and outcomes. Study Design/Setting: A non-systematic review of the literature is carried out. Methods: A narrative summary (including studies from the authors' own work in whiplash injuries) of the available literature is provided. Results: An emerging body of evidence suggests that the combination of existing imaging sequences or the use of developing imaging technologies in tandem with a good clinical assessment of modifiable risk factors may provide important diagnostic information toward the exploration and development of more informed and effective treatment options for some patients with traumatic neck pain. Conclusions: Advancing imaging technologies may help to explain the seemingly disconnected spectrum of biopsychosocial signs and symptoms of traumatic neck pain

An RF scenario for protons and ions in the PS2

The PS2 is proposed as a replacement for the ageing PS and will provide proton beams with kinetic energies up to 50 GeV. It must also deliver Pb54+ ions, for which the revolution frequency swing will be more than a factor of two. The favoured rf scenario considers a 40 MHz accelerating system and is motivated by the possibility of chopping at up to 40 MHz in the LPSPL, the proposed proton injector. Using the same principal rf system for ions implies pushing for an unprecedented tuning range and the introduction of a new rf system in LEIR, the existing ion source. We present a solution to the disparate requirements of protons and ions based on a 40 MHz rf system with switchable tuning ranges to cover the large frequency swing required

RF Scenarios for Pb54+ Ions in the PS2

This note analyses some of the rf scenarios that are presently being considered for lead ions in the PS2. An earlier note principally concerning protons [1] highlighted the problem of the large revolution frequency swing of ions in the PS2 and the issue of bunching factor with direct injection from the LEIR machine. We present solutions based on additional rf systems in LEIR and consider the 40 MHz principal rf system proposed for the PS2 in the earlier work to have switchable tuning ranges to cover the large frequency swing required

Information Efficiency of Binary Communication Systems (Final Report v.I)

Most of the work which has been done with binary communication systems up until now has assumed operation in a symmetric mode. This work is concerned with the problem of evaluating various combinations of modulation and detection in both symmetric and non-symmetric modes of operation. The most frequently used criterion for describing performance in a binary system is total probability of error, A discussion of this and other criteria such as realizable rate and minimum energy per bit factors is given. A new criterion called information efficiency is defined which is based on realizable information rate on a per symbol basis. The primary advantage of this criterion is that it gives a truer indication of performance than probability of error in the case of unsymmetric operation. Several types of conventional binary systems are analyzed and compared under the conditions that additive gaussian white noise is the only perturbing influence. Systems considered include amplitude shift keying or a carrier on-off type of modulation with linear envelope detection and with synchronous detection, phase shift keying of a phase reversal type of modulation with both synchronous and phase comparison detection schemes, Performance curves showing information efficiency and probability of error as functions of signal-to-noise ratio are given. A similar type of analysis is given for a group of matched filter systems which includes both coherent and non-coherent matched filter detection of amplitude and frequency shift keyed signals in the face of gaussiam white noise and the coherent matched filter detection of phase shift keyed signals,, Also included are some results concerning the use of differentially coherent detection of phase shift keyed signals. The response of various systems to variations in decision thresholds is examined and it is shown that phase shift keyed systems are superior in this respect. The optimum detection of amplitude shift keyed signals requires a variable threshold level for different conditions at the detector input, fee case of fixed threshold systems is examined and it is shown that a fixed threshold limits the maximum attainable performance of the system and that there is a distinct trade-off between this maximum possible performance at high signal-to-noise ratios, and good performance (i.e., near optimum) at low signal-to-noise ratios. The problem of Rayleigh fading is discussed and indications of fading on the performance of the various systems is given. Finally, all of the systems discussed are compared on the same basis by using a time bandwidth product which allows the signal-to-noise ratios bn which the conventional system analysis is based to be converted to an energy per symbol to noise spectral density ratio, which is the basis for matched filter analysis