Lipidomic analysis of Arabidopsis seed genetically engineered to contain DHA

Metabolic engineering of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA) in oilseeds has been one of the key targets in recent years. By expressing a transgenic pathway for enhancing the synthesis of the ω3 LC-PUFA docosahexaenoic acid (DHA) from endogenous α-linolenic acid (ALA), we obtained the production of fish oil-like proportions of DHA in Arabidopsis seed oil. Liquid chromatography-mass spectrometry (LC-MS) was used to characterize the triacylglycerol (TAG), diacylglycerol (DAG) and phospholipid (PL) lipid classes in the transgenic and wild type Arabidopsis seeds at both developing and mature stages. The analysis identified the appearance of several abundant DHA-containing phosphatidylcholine (PC), DAG and TAG molecular species in mature seeds. The relative abundances of PL, DAG, and TAG species showed a preferred combination of LC-PUFA with ALA in the transgenic seeds, where LC-PUFA were esterified in positions usually occupied by 20:1ω9. Trace amounts of di-DHA PC and tri-DHA TAG were identified and confirmed by high resolution MS/MS. Studying the lipidome in transgenic seeds provided insights into where DHA accumulated and combined with other fatty acids of neutral and phospholipids from the developing and mature seeds. © 2014 Zhou, Callahan, Shrestha, Liu, Petrie and Singh.

Development of disease caused by Phytophthora cinnamomi in mature Xanthorrhoe australis

Over the past 30 years, heathland and open forest communities in south-eastern Australia dominated by Xanthorrhoea australis R.Br. have been severely affected by disease caused by Phytophthora cinnamomi Rands. The disease has caused a sharp decline in numbers of individuals within populations of X. australis; however, the etiology of the disease is unclear. The characteristics and disease symptoms induced by P. cinnamomi were analysed within nine mature X. australis plants that had been removed from the field. Seven plants showed typical disease symptoms that ranged from chlorotic leaves through to plant death. Plants showing disease symptoms had different numbers of infected roots, ranging from 0% in one dead plant, 40% infected roots in a plant showing yellowing of leaf tips and 67 and 86%, respectively, in two plants with severe chlorosis. There was variation within the roots, with some infected close to the stem while others were infected at more distal regions. Within stems of all plants, P. cinnamomi was difficult to isolate but was found in the desmium and stem apex and was associated with massive lesions within the central area of the stem. The symptoms of disease in X. australis are caused by a combination of damage to tissues of the roots and stem that may lead to a reduction in water and mineral transport throughout the plant.

Mature women and the New Zealand qualifications framework : realising the potential of recognising prior learning

Against a background of 'second-wave' lifelong learning in Aotearoa New Zealand a new framework for post-compulsory national qualifications was introduced. The resulting competency-based system was argued to present a number of benefits for mature women including flexibility in curriculum and delivery and portability across educational sectors. Competency-based education was to include provision for recognition of prior skills and knowledge gained in formal learning environments and the workplace as well as informal learning environments such as the home and the community. Such recognition was a significant factor in gaining support from women’s groups given the potential to recognize and value the domestic labour of women and the skills and knowledge that flow from it. This article explores the rhetoric around recognition of prior learning and discusses approaches to realise its potential. It then draws on research undertaken in Aotearoa New Zealand to suggest that the potential of recognition of prior learning is yet to be realised.

Towards the mature ePortfolio : some implications for higher education

Electronic portfolios [ePortfolios] are a recent addition to the language of higher education. Commencing with a summary of their role from EDUCAUSE, whose mission is to advance higher education by promoting the intelligent use of information technology, the distinctive characteristics of ePortfolios are outlined and salient differences from conventional portfolios in terms of process and outcomes are explored. Having considered the attributes of a mature ePortfolio, the paper focuses on pedagogical and technological issues for students and staff to move to mature ePortfolios. While accepting the valuable role ePortfolios can play in higher education, and that students increasingly come to the tertiary sector with expectations and experience that appear to warrant this approach, the paper concludes that decision making in this area is not yet adequately supported by research. Educators need to be open to the promise ePortfolios offer their students and staff but be aware of the implications for their adoption.

Mature workers, training and using TLM frameworks

Mature workers have been at the centre of policies aimed at encouraging higher workforce participation, longer working life and enhanced savings for retirement. Low mature age workforce participation rates reflect labour market withdrawal in the face of multiple barriers to participation for many. Their apparent voluntary joblessness conceals the fact that mature workers endure longer periods of unemployment, discrimination, redundancy and other barriers to employment (hence the drift to 'early retirement'). The policy dilemma is not just about addressing discrimination barriers, access to appropriate retraining or skills enhancement for mature workers, but what this tells us about lifelong learning as a means of managing and mitigating risk. The mismatch between work opportunities/skills shortages and the low education and skills base of many mature workers, means it is simplistic to think that working longer might be a short term way to address skills shortages; without an enormous investment in the current ageing cohort. Drawing on Transitional Labour Market (TLM) theory and European reform agendas, this article argues that the link between investment in lifelong education/ skills training and stronger labour market participation needs attention; not just for current cohorts of excluded or underemployed mature workers but to position strategically for future generations.

Older and wiser?: a comparison of the learning and study strategies of mature age and younger teacher education students

'Non-traditional' students are increasingly a part of university populations. This study examined differences between mature age and younger university students in their learning and study strategies as measured by the Learning and Study Strategies Inventory (LASSI). Subjects were 21 mature age and 104 younger teacher education students enrolled in The Bachelor of Teaching (Primary) course at the Royal Melbourne Institute of Technology. Significant correlations were found between the students' LASSI scores and both their self-reported level of global skill and their perceptions of how difficult the course was. There were significant differences between the two groups in terms of their learning and study strategies, with mature age students reporting themselves to be using effective strategies more often, on average, than younger students. The validity and implications of these findings in terms of student learning, support and instruction in study and learning and in predicting academic success are discussed.

Consumer loyalty versus propensity to switch between providers in mature IT markets (the case of mobile phone market)

The example of the youth mobile phone market is used for pilot empirical testing of a model of consumers’ decision making, based on common features of consumer behaviour in mature markets of information and high technology products. Firstly, we discuss the key properties of mature high technology markets which affect market behaviour and strategies. These properties include: established customer and provider bases; the elements of both oligopolistic and monopolistic competition; very short product life cycle; considerable product differentiation; and using product quality, versioning and price discrimination as planning and marketing tools. Secondly, a model of consumers’ decision making in such markets is suggested on the assumption that a choice is to be made between the following options: to continue using the existing version of the product, to upgrade it with the current provider or to switch to another provider. Product price, quality characteristics, switching costs and network effects are demonstrated to be the variables affecting consumers’ decisions and therefore, these variables should be considered by competing providers when they choose production and marketing strategies. In conclusion, the results of the empirical study are discussed in the context of their possible application to other information and high technology markets.

Competition in mature software markets

A theoretical framework is built for capturing properties of competition in mature monopolistic digital product markets. Based on an empirical study of the market of accounting software for small and medium enterprises, a consumer choice model is suggested, where a rational consumer is already using a particular version of a software package and is considering to chose from the following three options: either to continue using it, or to upgrade to a newer version of the product, or to switch to a competitive product. Consumer decision is justified by software quality, and network effects, under the price and switching costs constrains. A modified consumer demand function is used for the model, and theoretical conditions are analysed for choosing from one of the three above-mentioned options. The results are applicable to a wide range of digital products.

Competition in the mature markets of professional versus final consumer information products

Factors are explored of decision making in regard to buying and/or upgrading information products. Mature information product markets are considered. Comparing two cases - professional and final consumer information products - the decision making process is considered on the choice of product variant. We distinguish three groups of users according to their ultimate decisions to either not to upgrade the existing system, or to upgrade it with the existing provider, or to switch to another provider. Consumer decision is based on multiple characteristics of information product quality, network effects, price and switching costs, whereas producers have to compete not only with their competitors, but also with the previous versions of the own products. Based on the considered cases, differences in consumer priorities are discussed in the markets of professional versus final consumer information products.

Spermatogenesis in the blue swimming crab, Portunus pelagicus, and evidence for histones in mature sperm nuclei

Spermatogenesis in the blue swimming crab, Portunus pelagicus, is described by light and electron microscopy. The testis is composed of anterior (AT) and posterior (PT) lobes, that are partitioned into lobules by connective tissue trabecula, and further divided into zones (germinal, transformation and evacuation), each with various stages of cellular differentiation. The vas deferens is classified into three distinct regions: anterior (AVD), median (MVD), and posterior (PVD), on the presence of spermatophores and two secretions, termed substance I and II. Based on the degree and patterns of heterochromatin, spermatogenesis is classified into 13 stages: two spermatogonia (SgA and SgB), six primary spermatocytes (leptotene, zygotene, pachytene, diplotene, diakinesis, and metaphase), a secondary spermatocyte (SSc), three spermatids (St 1–3), and a mature spermatozoon. Spermatid stages are differentiated by chromatin decondensation and the formation of an acrosomal complex, which is unique to brachyurans. Mature spermatozoa are aflagellated, and have a nuclear projection and a spherical acrosome. AUT-PAGE and Western blots show that, during chromatin decondensation, there is a reduction of most histones, with only small amounts of H2B and H3 remaining in mature spermatozoa.

Relationship of weaning weight to the mature liveweight of cashmere does on Australian farms

Median weaning weight and its relationship with the median mature liveweight of does was quantified for four commercial Australian cashmere farms in various parts of Australia. Individual liveweights, of does of all ages at the time of weaning in December, ranged from 9 to 61 kg. Individual farm means of adult does (>1 year old) ranged from 24.6 to 38.8 kg. The model for the logarithm of liveweight was: log₁₀(liveweight) = a + br ^{(Age + 0.6);} where a, b and r are parameters that are different for each farm. The result that the r parameter differs with farm was statistically significant (P = 9.4 10^-6). The percentage variance accounted for was 84.4% and the residual standard deviation was 0.042. Farms differed greatly in the median mature liveweight with some farms reaching ~44 kg and others only 31 kg. Median weaning weight was 14.1 kg (range 11.4-16.8 kg). Median weaning weight as a percentage of median mature doe liveweight on a particular farm varied from 32 to 42%. These weaning weights appear low in absolute and relative terms and thus are likely to incur production penalties.