Control of flowering time in temperate cereals: genes, domestication, and sustainable productivity

The control of flowering is central to reproductive success in plants, and has a major impact on grain yield in crop species. The global importance of temperate cereal crops such as wheat and barley has meant emphasis has long been placed on understanding the genetics of flowering in order to enhance yield. Leads gained from the dissection of the molecular genetics of model species have combined with comparative genetic approaches, recently resulting in the isolation of the first flowering time genes in wheat and barley. This paper reviews the genetics and genes involved in cereal flowering pathways and the current understanding of how two of the principal genes, Vrn and Ppd, have been involved in domestication and adaptation to local environments, and the implications for future breeding programmes are discussed.

Temporality, cultural biography and seasonality: rethinking time in wetland archaeology

Wetland archaeology is uniquely well placed to investigate questions of chronology, temporality, life-cycles and seasonality. Beyond the usual archaeological approaches to time (eg seriation, typology and stratigraphy), most wetland archaeological investigations have access to a ready supply of samples (ie wood, peat and organic deposits) for absolute scientific dating, particularly radiocarbon and dendrochronology. Indeed, the success of dendrochronology in revealing dynamic sequences of site and regional occupation, use and abandonment are well known. Investigating wetland archaeological sites, environmental archaeologists have used the evidence of insects' plant remains, seeds and even testate amoeba to establish the season, or months, of a site's occupation. Soil micromorphologists have carried out innovative studies of settlement deposits to reconstruct the chronological sequences of processes and events leading to their formation. In brief, wetland archaeology has become adept at calibrating past times.

Molecular and phenotypic characterization of the alternative seasonal growth habit and flowering time in barley (Hordeum vulgare ssp. vulgare L.)

Barley can be classified into three major agronomic types, based on its seasonal growth habit (SGH): spring, winter and alternative. Winter varieties require exposure to vernalization to promote subsequent flowering and are autumn-sown. Spring varieties proceed to flowering in the absence of vernalization and are sown in the spring. The ‘alternative’ (also known as ‘facultative’) SGH is only loosely defined and can be sown in autumn or spring. Here, we investigate the molecular genetic basis of alternative barley. Analysis of the major barley vernalization (VRN-H1, VRN-H2) and photoperiod (PPD-H1, PPD-H2) response genes in a collection of 386 varieties found alternative SGH to be characterized by specific allelic combinations. Spring varieties possessed spring loci at one or both of the vernalization response loci, combined with long-day non-responsive ppd-H1 alleles and wild-type alleles at the short-day photoperiod response locus, PPD-H2. Winter varieties possessed winter alleles at both vernalization loci, in combination with the mutant ppd-H2 allele conferring delayed flowering under short-day photoperiods. In contrast, all alternative varieties investigated possessed a single spring allele (either at VRN-H1 or at VRN-H2) combined with mutant ppd-H2 alleles. This allelic combination is found only in alternative types and is diagnostic for alternative SGH in the collection studied. Analysis of flowering time under controlled environment found alternative varieties flowered later than spring control lines, with the difference most pronounced under short-day photoperiods. This work provides genetic characterization of the alternative SGH phenotype, allowing precise manipulation of SGH and flowering time within breeding programmes, and provides the molecular tools for classification of all three SGH categories within national variety registration processes.

Anomalous dependence on the diffusion coefficients of the ionic relaxation time in electrolytes

We show, by using a numerical analysis, that the dynamic toward equilibrium for an electrolytic cell subject to a step-like external electric field is a multirelaxation process when the diffusion coefficients of positive and negative ions are different. By assuming that the diffusion coefficient of positive ions is constant, we observe that the number of involved relaxation processes increases when the diffusion coefficient of the negative ions diminishes. Furthermore, two of the relaxation times depend nonmonotonically on the ratio of the diffusion coefficients. This result is unexpected, because the ionic drift velocity, by means of which the ions move to reach the equilibrium distribution, increases with increasing ionic mobility.

Microwave induced magnetoresistance oscillations and inelastic scattering time in double quantum wells

The interference of microwave-induced resistance oscillations and magneto-intersubband oscillations in double quantum wells exposed to a continuous microwave irradiation is under study. By comparing experimental and theoretical magnetoresistance traces at different temperatures, we confirm that the inelastic mechanism of photoresistance explains our observations up to T similar or equal to 4 K. For higher temperatures, our results suggest a deviation of the inelastic scattering time tau(in) from the predicted T(-2) dependence. (C) 2009 Elsevier B.V. All rights reserved.

Changes over time in sexual and relationship functioning of people with multiple sclerosis

Relationship and sexual satisfaction among people with multiple sclerosis (MS) has received little research attention. This article reports on a longitudinal investigation of the impact of coping style and illness-related variables among people with MS and the general population on sexual and relationship functioning. Both men (n = 120) and women (n= 201) with MS and men (n = 79) and women (n = 160) from the general population participated in the study at two points in time, 6 months apart. People with MS experienced lower levels of sexual activity, sexual satisfaction, and relationship satisfaction and higher levels of sexual dysfunction. Generally speaking, the time 1 levels of the health and coping variables explained little of the variance in the time 2 sexual and relationship variables. However, sexual activity at time 1 contributed significant unique variance to relationship satisfaction at time 2 for MS men, and coping strategies at time I contributed to relationship satisfaction among general population women at time 2. Furthermore, for those respondents who had been diagnosed with MS for less than 7 years, levels of sexual activity at time 2 were predicted by levels of sexual and relationship satisfaction, as well as levels of sexual activity at time 1. These results suggest that strategies used to cope with illness may not play a major role in sexual and relationship satisfaction. However, an examination of these strategies over a longer time frame is needed.

Ageing effects on visual reaction time in a single task condition and when treadmill walking

Visual reaction time (RT) was measured in 10 older men (mean age, 71.1 years) and gender-matched controls (mean age, 26.3 years) when standing (single task) and when walking on a motor-driven treadmill (dual task). There were 90 quasirandomly presented trials over 15 min in each condition. Longer mean and median RTs were observed in the dual task compared to the single task. Older males had significantly slower mean and median RTs (315 and 304 ms, respectively) than the younger group (273 and 266 ms, respectively) in both task conditions. There were no age or condition effects on with in-subject variability. Both groups showed a trend of increasing RT over the 90 single task trials but when walking only the younger group slowed. These novel findings demonstrate high but sustained attention by older adults when walking. It is proposed that the motor task's attentional demands might contribute to their slower preferred walking speed.

Preparing Australia's future lawyers: an exposition of changing values over time in the context of teaching about ethical dilemmas

This study investigated what values may be influential to decision making in relation to ethical behaviour for early career lawyers. It adopted a longitudinal approach to investigate how values develop or degrade over time as final year law students move into their first two years of employment or further study. To this end, the study investigated the role that tertiary education and employers fulfill in building and perpetuating ‘appropriate’ professional values? Results demonstrate that, in general, ethical behaviour was not uniformly reinforced over time in the workplace. The undertaking of pro bono work stands out here. Results suggested that certain behaviour relevant values may develop or degrade over the early years of the Australian lawyer's career. The implications of results are discussed in the contexts of ethics education in a tertiary context and the continuing education and regulation of the legal profession.

"Where myth becomes history" : the politics of mythical time in Heiner Muller's Medea

Heiner Müller in the 1980s produced a sequence of plays featuring Euripides’ heroine Medea using his distinctive, poetic modality of “the theatre of images”. These ostensibly postmodern narratives take the form of disjointed, visual and textual representations that are also fragmentations of historical and mythical times and spaces. Müller’s Medea plays are thus suggestive of the intersection between the discourses of history and myth — and the blending of historical time with ahistorical, supposedly “timeless” mythical narratives. Further, the postmodern possibility of history’s textuality to liquidate it into a type of (modern) mythology seeks expression in the plays’ representation of a converse equation: the moment signaled in the text as that “where myth becomes history”. This paper examines the problematisation of the myth-history dichotomy in Müller’s Medea plays, outlining the ways in which the “timeless” myth of the classical, infanticidal figure of Medea is strategically deployed to politicise evolutionist teleology, Western colonialism and the technologies of war in twentieth century Europe.

Engagement and learning through social software in finance : the trading room experience

The introduction of a social software blog space called “The Trading Room” in an undergraduate Finance unit for an assessment task generated a great deal of activity to support student learning. A subsequent evaluation of this pilot demonstrated that students perceived high value in the opportunity it provided for them to reaffirm theories, obtain individualized feedback and benchmark their work against others. Whilst assessment is generally seen as both the carrot and the stick of learning, and certification; students in the study reported that they would still participate in reading and posting to the “Trading Room” blog even if there was no assessment requirement! Additionally they did not see any value in the environment as a purely social space, reporting that they saw it primarily as a professional educational community. It would appear that just as there are different communities in the real world social space, there are also different types of communities in the online space. Context, structure and activity design, perhaps are the most important facets of online interaction for learning.