Pastoral Farmer Goals and Intensification Strategies

Focus groups were held with four pastoral sectors (sheep, dairy, deer, and beef) to investigate intensification strategies available to each sector. Focus groups first identified drivers of intensification in their sector, then identified the strategies they perceived as available, and evaluated the identified strategies in terms of favourability. For a researcher selected intensification strategy in each pastoral sector, benefits, barriers and solutions, and the relationship between farmer goals and the selected strategy was examined. The three main drivers of intensification in the sheep industry were profit, higher land values and return on capital. The researcher chosen strategy, high fecundity sheep, was viewed by the focus group as having benefits of increased financial security, increased profit, better return on capital and better land utilisation. However the strategy was seen as conflicting with other desirable goals such as lifestyle, social life, work variety, self reliance, environmental concerns and animal welfare. The three main drivers of intensification in the dairy sector were declining market prices, need for increased profit and need for increased productivity. The researcher chosen strategy, robotic milking, was viewed as having benefits of: reduced labour requirements, enhanced lifestyle, greater job satisfaction, reduce operational costs and increased profit. Implementation cost was viewed as a barrier as was the need for new specialised technical skills. The three main drivers of intensification in the deer industry were return on investment, competition from other land uses and returns per hectare compared with other pastoral sectors. The researcher chosen strategy, 100kg weaner by 1st June, had benefits of increased management options, increased profit, achievement of animals’ genetic potential, better predictability and a higher kill-out yield. The strategy presents challenges to animal welfare – an important consideration for the group. Three industry enterprises (dairy, calf rearers, and beef finishers) are involved in beef production. All three agreed that profit was the main driver for intensification. The researcher chosen strategy was dairy/beef progeny. Benefits of this strategy for the industry were: increased profit, access to prime markets, higher yielding quicker growing animals, and better behaved animals. The primary barrier to the success of this strategy was the need for co-operation across the three industry enterprises and the processors, and the need to ensure increased profits are distributed to all parts of the chain. Dairy farmers (the source of 65% of animals farmed for beef) were particular concerned about animal welfare issues and the consequent financial risks presented to their operations by this strategy.Agribusiness, Agricultural Finance, Consumer/Household Economics, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Land Economics/Use, Livestock Production/Industries, Risk and Uncertainty,

Chromospheric seismology above sunspot umbrae

The acoustic resonator is an important model for explaining the three-minute oscillations in the chromosphere above sunspot umbrae. The steep temperature gradients at the photosphere and transition region provide the cavity for the acoustic resonator, which allows waves to be both partially transmitted and partially reflected. In this paper, a new method of estimating the size and temperature profile of the chromospheric cavity above a sunspot umbra is developed. The magnetic field above umbrae is modelled numerically in 1.5D with slow magnetoacoustic wave trains travelling along magnetic fieldlines. Resonances are driven by applying the random noise of three different colours---white, pink and brown---as small velocity perturbations to the upper convection zone. Energy escapes the resonating cavity and generates wave trains moving into the corona. Line of sight (LOS) integration is also performed to determine the observable spectra through SDO/AIA. The numerical results show that the gradient of the coronal spectra is directly correlated with the chromosperic temperature configuration. As the chromospheric cavity size increases, the spectral gradient becomes shallower. When LOS integrations is performed, the resulting spectra demonstrate a broadband of excited frequencies that is correlated with the chromospheric cavity size. The broadband of excited frequencies becomes narrower as the chromospheric cavity size increases. These two results provide a potentially useful diagnostic for the chromospheric temperature profile by considering coronal velocity oscillations

Particle-in-cell simulations of circularly polarised Alfvén wave phase mixing: A new mechanism for electron acceleration in collisionless plasmas

In this work we used Particle-In-Cell simulations to study the interaction of circularly polarised Alhén waves with one dimensional plasma density inhomogeneities transverse to the uniform magnetic field (phase mixing) in collisionless plasmas. In our preliminary work we reported discovery of a new electron acceleration mechanism, in which progressive distortion of the Alfvén wave front, due to the differences in local Alfvén speed, generates an oblique (nearly parallel to the magnetic field) electrostatic field. The latter accelerates electrons through the Landau resonance. Here we report a detailed study of this novel mechanism, including: (i) analysis of broadening of the ion distribution function due to the presence of Alfvén waves; and (ii) the generation of compressive perturbations due to both weak non-linearity and plasma density inhomogeneity. The amplitude decay law in the inhomogeneous regions, in the kinetic regime, is demonstrated to be the same as in the MHD approximation described by Heyvaerts & Priest (1983, A&A, 117, 220)

Xylem as well as phloem sustains severe damage due to feeding by the Russian wheat aphid

Investigation of comparative effects of feeding damage by the Russian wheat aphid (RWA, biotype SA1, Diuraphis noxia Mordvilko) on leaf blades of susceptible and resistant wheat cultivars (Triticum aestivum L. var Betta and Betta-Dn1 respectively) were carried out to establish the level of ultrastructural damage caused by this aphid and the possible limitation of damage induced which could be ascribed to the resistance gene Dn1 over the susceptible cultivar. Ultrastructurally, Betta-Dn1 sustained less damage to the vascular tissue as well as to the mesophyll during the experimental period. Both inter- and intracellular probes resulted in considerable saliva deposition as the aphids probed for suitable feeding sites. Salivary tracks were observed between and within mesophyll, bundle sheath cells as well as the vascular tissue, including the xylem. Disruption of organelles and cytoplasm resulted from cell probing and sheath deposition. Cell and organelle damage was more evident in the non-resistant Betta cultivar. The aphids probed for and fed from thin-walled sieve tubes preferentially. Few thick-walled sieve tubes showed evidence of either aphid probing or feeding-related damage. Saliva was deposited when the aphids probed inter- and intracellularly for feeding sites. The aphids appeared preferentially to probe for and feed from thin-walled sieve tubes, as few thick-walled sieve tubes showed evidence of damage. Vessels, apparently probed for water, contained watery saliva that encased the secondary walls and sealed pit membranes between probed vessels and xylem parenchyma. The xylem probed by the RWA was rendered non-functional, probably contributing to symptoms of leaf roll, chlorosis and necrosis, which were observed within two weeks of infestation in the susceptible Betta cultivar. This damage was limited in the resistant Betta-Dn1 cultivar during the same time frame

Sequencing the transcriptome of R570 to explore the complexity of the sugarcane genome [W1019]

Sugarcane is a crop of unequivocal importance which can meet requirements for food, feed fiber and fuel. This crop, with a large wealth of genetic resources and a rich breeding history, has only a very nascent genomic history with a monoploid genome sequence. Numerous efforts are underway to unravel the mysteries of this complex crop with advances in sequencing technologies. Efforts to capture the functional part of the genome using transcriptomic studies have long been a priority. R570, a French cultivar has been the most suitable material for many sugarcane genomics studies. In an attempt to utilize the revolutionary technology of long read sequencing, we have carried out isoform sequencing of this representative cultivar with a Pac Bio sequel I system. Recently we have compared sequel II data of the same cultivar from various vegetative and reproductive tissues. A greater sequencing depth may benefit the sugarcane fraternity with a more complete transcriptome and accurate gene annotation. The present study aimed at comparing sequel I and sequel II data for R570 to harness the information contained in the large transcriptome resources and to find novel sources of variation in the light of these recent advances. The results may support future transcriptomic studies in sugarcane to make informed decisions on depth of sequencing and help to unravel the complexities of this transcriptome

"Be active!" Revisiting the South African Food Based Dietary Guidelines for activity

The objective of this paper was to review current evidence on physical activity for health in order to support the foodbased dietary guideline (FBDG) “Be active!”. Physical activity, defined as at least 30 minutes of moderate-intensity physical activity per day for adults, and 60 minutes for children and adolescents, is advised in the FBDG because of the role it plays in maintaining energy balance, improving body composition and promoting general health and wellbeing. The reviewed outcome measures are changes in physical activity patterns and the reported prevalence of noncommunicable diseases (NCDs) in South Africa. Despite the previous set of FBDGs, no improvements in physical activity, obesity or NCDs have been reported in South Africa. Recent literature emphasises the beneficial effects of physical activity on the reduction of risk factors associated with the prevalence of NCDs. Physical activity has a positive effect on appetite and weight control, insulin sensitivity, dyslipidaemia, hypertension, stress relief and burnout. Barriers that prevent children and adults from participating in regular physical activity have been identified, and recommendations how to overcome these have been made. It has been concluded that South Africans are not sufficiently physically active for their general health status to be improved. It is recommended that methods to promote physical activity at national, provincial, district and local level need to be developed, implemented and sustained