Shedding light on the role of bHLH transcription factors in Arabidopsis thaliana male reproductive development

Development of viable pollen in the anther locule is crucial for plant reproduction, and relies upon secretion of proteins, lipids, polysaccharides and other essential molecules from the surrounding tapetum tissue. Tapetum development in Arabidopsis thaliana is regulated by a number of genes including the basic Helix Loop Helix (bHLH) transcription factors DYSFUNCTIONAL TAPETUM (DYT1) and ABORTED MICROSPORES (AMS), which interact competitively with bHLH010, bHLH089 and bHLH091 to regulate downstream targets involved in synthesis and secretion of pollen wall components. Disruption of genes within the tapetum development pathway leads to male sterility and previous research has shown that ams, dyt1 and bhlh089 bhlh010 amiR-bHLH091 knockout mutants are completely male sterile, whereas the single and double bhlh010, -089 and -091 mutants are mostly fertile due to a high level of functional redundancy. In this thesis bhlh089 bhlh091 and bhlh089 bhlh010 double mutants are revealed to show light-sensitive sterility, alongside recent observations of thermosensitive male sterility. In low light conditions, both bhlh double mutants exhibit severe pollen wall defects; however, whereas the bhlh89,10 double mutant shows later recovery of fertility, bhlh89,91 remains sterile throughout development suggesting that bHLH89, -91 and -10 have distinct functions in maintaining fertility in response to environmental stress. RNASeq analysis of wild type and bhlh89,91 mutant light response highlighted differential regulation of genes related to sexual reproduction and hormonal responses. As transient assays demonstrated that bHLH89, 91 and -10 interact with DELLA proteins and MYB33/65, and bHLH-AMS heterodimers were found to more strongly induce target gene expression, it’s proposed that DELLA-dependent sequestration of bHLHs in different light environments regulates formation of AMS-bHLH dimers that activate genes involved in pollen development. bHLH89, -91 and -10 are further shown to undergo post-translational modifications leading to a new hypothesis on their role in regulating reproductive development in adverse conditions

Investigating the effectiveness of spatial frequencies to the left and right of central vision during reading:Evidence from reading times and eye movements

Printed words are complex visual stimuli containing a range of different spatial frequencies, and several studies have suggested that various spatial frequencies are effective for skilled adult reading. But while it is well known that the area of text from which information is acquired during reading extends to the left and right of each fixation, the effectiveness of spatial frequencies falling each side of fixation has yet to be determined. To investigate this issue, we used a spatial frequency adaptation of the gaze-contingent moving-window paradigm in which sentences were shown to skilled adult readers either entirely as normal or filtered to contain only low, medium, or high spatial frequencies except for a window of normal text around each point of fixation. Windows replaced filtered text either symmetrically 1 character to the left and right of each fixated character, or asymmetrically, 1 character to the left and 7 or 13 to the right, or 1 character to the right and 7 or 13 to the left. Reading times and eye-movement measures showed that reading performance for sentences presented entirely as normal generally changed very little with filtered displays when windows extended to the right but was often disrupted when windows extended to the left. However, asymmetrical windows affected performance on both sides of fixation. Indeed, increasing the leftward extent of windows from 7 to 13 characters produced decreases in both reading times and fixation durations, suggesting that reading was influenced by the spatial frequency content of leftward areas of text some considerable distance from fixation. Overall, the findings show that while a range of different spatial frequencies can be used by skilled adult readers, the effectiveness of spatial frequencies differs for text on each side of central vision, and may reflect different roles played by these two areas of text during reading

Identity Implications of Relationship (Re)Definition Goals: An Analysis of Face Threats and Facework as Young Adults Initiate, Intensify, and Disengage from Romantic Relationships

DOI: 10.1177/0261927X08325746Identity implications theory (IIT) is applied to analyze how young adults manage identity concerns associated with the goals of initiating, intensifying, and disengaging from romantic relationships. Participants wrote their responses to one of six hypothetical romantic (re)definition scenarios, indicated whether they actually would pursue the relational goal if their scenario were real, and rated degree of threat to both parties' face. Responses were coded for positive and negative politeness strategies. Participants in different relational goal conditions perceived different face threats, varied in their likelihood of pursuing the relational goal, and employed different politeness strategies. Relationship (re)definition goal also moderated associations between perceived face threats and goal pursuit as well as politeness strategies. The findings show how multiple goal theories such as IIT can be applied to situations where relational goals are primary as well as how, to varying degrees, identity concerns shape and constrain how young adults pursue relational (re)definition goals

Reconceptualising well-being: social work, economics and choice

In this paper we examine the intersection of well-being, agency and the current political and economic structures which impact on social work with adults and in doing so contribute to ‘interpreting and mapping out the force fields of meaning production’ (Fornäs, Fredriksson & Johannisson 2011: 7). In it we draw upon Sointu’s (2005) work which identified the shift from conceptualising well-being in terms of ‘the body politic’ to conceptualising it in terms of ‘the body personal’ and identified parallels with understanding well-being in English social work. There has been a shift in the nature of social work in the United Kingdom in how the question of agency has been addressed. For many years this was through the traditional notion of autonomy and self-determination (Biestek 1961) and later collective approaches to welfare and services (Bailey & Brake 1975). The development of paradigms of mainly personal empowerment in the 1980s and 1990s (Braye & Preston-Shoot 1995) saw social work become less associated with collective engagement in welfare and more concerned with the enhancement of individual well-being (Jordan 2007). Whilst the rhetoric of well-being, in contemporary English social work, continues to include autonomy and self-determination, this is focused primarily upon the narrower concepts of independence and choice (Simpson 2012). The UK Department of Health’s A Vision for Adult Social Care: Capable Communities and Active Citizens (DoH 2010) is the template for national social care policy to which all Local Authorities in England had to respond with an implementation plan. This paper draws on a documentary analysis of two such plans drafted in 2012 in the wake of an ‘austerity budget’ and consequent public expenditure reductions. The analysis considers the effect of economic imperatives on the conceptualisation of individual choices and needs in the context of Local Authorities’ responsibilities to people collectively. A concept of ‘reasonableness’ emerges, which is used to legitimize a re-balancing of the ‘body personal’ and the ‘body politic’ in the concept of well-being with the re-emergence of an economic, public construction. Our discussion considers why this is happening and whether or not a new synthesised position between the personal and political is being developed, as economists and policy makers appropriate well-being for their ends

A Combined Spectrophotometer and Fluorometer to Demonstrate the Principles of Absorption Spectroscopy

A dual-function student-crafted instrument is described as part of a laboratory activity aimed to teach both the principles and practical aspects of absorption spectroscopy to secondary and introductory undergraduate students. Using minimal changes in an arrangement that is based on interlocking bricks and low-cost components, both a fluorometer and photometer have been constructed. The former demonstrates the principles of the Beer–Lambert law visually and quantitatively by acquiring the spatial light attenuation through a fluorescent sample. The latter then demonstrates its practical application in a visible-light spectrometer by measuring the absorption spectrum of an aqueous permanganate solution

The Safety and Effect of Topically Applied Recombinant Basic Fibroblast Growth Factor on the Healing of Chronic Pressure Sores

The first randomized, blinded, placebo-controlled human trials of recombinant basic fibroblast growth factor (bFGF) for pressure sore treatment were performed. Three different concentrations of bFGF in five dosing schedules were tested for safety using hematology, serum chemistries, urinalysis, absorption, antibody formation, and signs of toxicity. Efficacy was evaluated by wound volumes, histology, and photography. No toxicity, significant serum absorption, or antibody formation occurred. In six of eight subgroups, there was a trend toward efficacy with bFGF treatment. When all subgroups were combined, comparison of the slopes of the regression curves of volume decrease over initial pressure sore volume demonstrated a greater healing effect for the bFGF-treated patients (p 70% wound closure (p < 0.05). Blinded observers were able to distinguish differences in visual wound improvement between bFGF and placebo groups. These data suggest that bFGF may be effective in the treatment of chronic wounds

Forty years studying British politics : the decline of Anglo-America

The still present belief some 40 years ago that British politics was both exceptional and superior has been replaced by more theoretically sophisticated analyses based on a wider and more rigorously deployed range of research techniques, although historical analysis appropriately remains important. The American influence on the study of British politics has declined, but the European Union dimension has not been fully integrated. The study of interest groups has been in some respects a fading paradigm, but important questions related to democratic health have still to be addressed. Public administration has been supplanted by public policy, but economic policy remains under-studied. A key challenge for the future is the study of the management of expectations