Role of short RNAs in gene silencing

Recent research has revealed the existence of an elegant defence mechanism in plants and lower eukaryotes. The mechanism, known in plants as post-transcriptional gene silencing, works through sequence-specific degradation of RNA. It appears to be directed by double-stranded RNA, associated with the production of short 21-25 nt RNAs, and spread through the plant by a diffusible signal. The short RNAs are implicated as the guides for both a nuclease complex that degrades the mRNA and a methyltransferase complex that methylates the DNA of silenced genes. It has also been suggested that these short RNAs might be the mobile silencing signal, a suggestion that has been challenged recently.

From Prosumption to Produsage

Almost a decade after the 2004 O’Reilly Media conference which popularized the term ‘Web 2.0’, the impact of this concept on users and developers of the current generation of Web technology – and by extension, on the digital economy overall – is undeniable. At the time, ‘Web 2.0’ promised an interactive, engaging online space in which users were able to do more than surf from static, fixed Website to static, fixed Website. Although the implicit suggestion that the version change to ‘Web 2.0’ represented a clean break with this inflexible past must be read as mere marketing hype, the core principles which the concept outlined nonetheless form the operational basis for most mainstream Websites of the present day.

The power of percent

Which statistic would you use if you were writing the newspaper headline for the following media release: "Tassie’s death rate of deaths arising from transport-related injuries was 13 per 100,000 people, or 50% higher than the national average”? (Martain, 2007). The rate “13 per 100,000” sounds very small whereas “50% higher” sounds quite large. Most people are aware of the tendency to choose between reporting data as actual numbers or using percents in order to gain attention. Looking at examples like this one can help students develop a critical quantitative literacy viewpoint when dealing with “authentic contexts” (Australian Curriculum, Assessment and Reporting Authority [ACARA], 2013a, p. 37, 67). The importance of the distinction between reporting information in raw numbers or percents is not explicitly mentioned in the Australian Curriculum: Mathematics (ACARA, 2013b, p. 42). Although the document specifically mentions making “connections between equivalent fractions, decimals and percentages” [ACMNA131] in Year 6, there is no mention of the fundamental relationship between percent and the raw numbers represented in a part-whole fashion. Such understanding, however, is fundamental to the problem solving that is the focus of the curriculum in Years 6 to 9. The purpose of this article is to raise awareness of the opportunities to distinguish between the use of raw numbers and percents when comparisons are being made in contexts other than the media. It begins with the authors’ experiences in the classroom, which motivated a search in the literature, followed by a suggestion for a follow-up activity.

Acticoat™ : A cost-effective and evidence-based dressing strategy [Letter to the Editor]

We thank Dr. Burd et al. for taking an interest in our paper [1]. The retrospective cohort study was performed and published for two reasons. Firstly, we wished to compare and contrast the use of Acticoat™ and Silvazine™, and secondly we wished to demonstrate how one's practice can be dramatically altered by a change in dressing used. We found that Acticoat™ was safe and easy to use, caused less trauma to patients, required less frequent dressing changes and enabled treatment to be conducted on an outpatient, rather than an inpatient basis. During the period of Acticoat™ treatment we also saw a dramatic reduction in grafting requirements and also in the need for long-term scar management. Burd et al. correctly state that silver-based dressings are now more widely available, however many burn centres in the world continue to use silver sulphadiazine with daily baths. We therefore feel that a comparison is very relevant and useful. Prospective, randomised clinical trials of a range of silver-based dressings would indeed be useful, and hopefully Dr. Burd and colleagues will take up their own suggestion and perform these studies...

Do we need to prescribe exercise differently for premenopausal and postmenopausal women?

The article by Kretzschmar et al 1 in this issue of Menopause details a study investigating the effect of a mild-intensity aerobic exercise training program on markers of mortality risk in both pre- and post-menopausal African American women. The findings of this study showed that aerobic exercise training was successful in improving some markers of cardiovascular disease (CVD) and mortality in post-menopausal women. The premise of this study, however, does suggest that increased exercise intensity may be required in post-menopausal women as opposed to pre-menopausal women to achieve the same decreased changes in CVD markers. The outcome of the study is thus of interest to the readers of Menopause and to all those who provide health care to postmenopausal women, as it suggests that higher levels of exercise intensity or perhaps additional interventions may need to be considered in this population to further decrease mortality risk. The study therefore, has greater implications than simply the suggestion of tailoring exercise interventions generally; rather, the publication highlights the importance of prescribing exercise as medicine in a tailored fashion for women depending on their menopausal status.

Pulping affirmation : Danny Wallace’s Yes Man!

If Danny Wallace is a yes man, I am most certainly a no woman. No, I will not agree to anything and everything in an attempt to make my life “more interesting”. No, I do not believe that on “one fateful day a mystery man on a late night bus” will change my life forever. I hate the bus. In fact, I don’t even catch public transport. Wallace’s recent film tie-in Yes Man reeks of such cheesy optimism. The book’s premise is simple and indeed, even alluring at first. When a stranger on the bus tells Danny to “say yes more” (9), his life takes a dramatic turn on the roundabout of possibility. Sad, single, and staying inside a lot, Danny signs himself up for a year of mishap and misadventure, accepting every request, suggestion and invitation offered to him by both friends and strangers.

Superoxide does react with peroxides : direct observation of the haber-weiss reaction in the gas phase

The fact that nature provides specific enzymes to selectively remove superoxide (O2.−) from aerobic organisms, namely, the superoxide dismutase enzymes,1 has led to the suggestion that this radical ion may cause the oxidative damage associated with degradative disease and aging.2 Intriguingly, however, superoxide itself is relatively unreactive toward most cellular components, which suggests that dismutase enzymes may ultimately protect the cell against more pernicious oxidants formed from superoxide. As such, there is increasing interest in the endogenous chemistry of superoxide and the pathways by which it might beget more reactive oxygen species. Protonation of superoxide to form the hydroperoxyl radical (HOO.) and dismutation of the same species to hydrogen peroxide (HOOH), with subsequent metal-catalyzed reduction to the hydroxyl radical (HO.), are well-characterized processes in which both the HOO. and HO. radicals are significantly more reactive than their common progenitor.2 Recent examples, however, have also linked superoxide to the putative production of singlet oxygen3 and ozone,4, 5 although the definitive characterization of these chemistries in the cellular milieu has proved challenging

Histories of user-generated content : between formal and informal media economies

Debates about user-generated content (UGC) often depend on a contrast with its normative opposite, the professionally produced content that is supported and sustained by commercial media businesses or public organisations. UGC is seen to appear within or in opposition to professional media, often as a disruptive, creative, change-making force. Our suggestion is to position UGC not in opposition to professional or "producer media", or in hybridised forms of subjective combination with it (the so-called "pro-sumer" or "pro-am" system), but in relation to different criteria, namely the formal and informal elements in media industries. In this article, we set out a framework for the comparative and historical analysis of UGC systems and their relations with other formal and informal media activity, illustrated with examples ranging from games to talkback radio. We also consider the policy implications that emerge from a historicised reading of UGC as a recurring dynamic within media industries, rather than a manifestation of consumer agency specific to digital cultures.

Celebrating and sustaining Indigenous knowledges through research

This paper reports on the growth of research within the World Indigenous Nations Higher Education Consortium (WINHEC). The focus is the research and later, research and journal working group. The intent is to discuss the publication of the WINHEC Journal, discussion papers and other activities such as the development of the Research Standards while analysing the underpinning imperatives to such work. The paper will also examine the complexity of progressing research, founded in local knowledge, aligned internationally to broader conceptions of Indigenous knowledge. The suggestion underlying this paper is that if research is undertaken from a position of Indigenous knowledge and epistemology, it will celebrate and sustain Indigenous people.

The relationship between small firm growth and HRM practices

The relationship between small firm growth and HRM practices Rowena Barrett, Susan Mayson and Niel Warriner Introduction In this chapter we explore the relationship between small firms’ growth orientation, their business planning efforts and the role the owner plays and whether or not formal HRM practices are used. Formal HRM practices are assessed in terms of whether they are written down, regularly applied or assured to take place. We take on board Heneman et al.’s (2000) suggestion that ‘surveys of employer practices across SMEs [would] be [a] valuable addition to the strategic human resource management literature’ (p. 23) and report the results of an online and paper survey of a sample of 1753 small firms (defined as those employing less than 20 people) in the state of Victoria (SE Australia). Our particular interest in this chapter, which is based on an analysis of 410 responses to the survey, is whether growthoriented small firms adopt formal HRM practices. This research contributes to understanding whether more formal organizational systems and routines are more likely to be used (or not) to nurture human capital in growth-oriented small firms. Moreover by focusing on firm growth, this chapter, consistent with recent calls in the literature (see Baron, 2003; Barrett and Mayson, 2006; Katz et al., 2000; Tansky and Heneman, 2003), contributes to a better understanding of issues at the intersection of entrepreneurship and HRM research.

Women IN Sport or Women OR Sport - The search for work/sport/life balance.

The current ‘holy grail’ for our health and well-being centres around the search for, and establishment of, a work/life balance. For many individuals, this appears to be an ever-elusive goal – forever slipping from our grasp as we juggle the day-to-day battle for our attention and time from an array of sources. When we add the word ‘Women’ to this mix, often the number of sources related to these demands multiplies in alignment with the number of roles we fill. To take this to even another level, consider the addition of the words ‘Sport’ or ‘Elite Athlete’ to ‘Women’ and ‘Work/Life Balance’, and the search for the ‘holy grail’ becomes more literal! Many sportswomen at the elite level face significant challenges in balancing working to support themselves and/or their families, studying to lay the foundations of a post-sport career, (often) spending the equivalent of full-time hours training towards their sporting goals, and additionally investing in the things that are important for them outside of these two areas – the ‘Life’ component. Getting the work/life balance ‘balanced’ has been suggested to be a key component of investing in our health and well-being. The same is applicable to sportswomen, with the added suggestion that if the balance between work/sport/life is achieved, this can positively impact upon sporting performance itself. These ideas and observations will be explored via experience within the Australian elite sporting environment from a psychologist’s perspective, with questions and invitations for further discussion.

Resistance or covert infection : baculovirus studies re-examined

Recently, Boots & Begon (1993) described the development of resistance to granulosis virus (GV) (Baculoviridae) infection in the moth Plodia interpunctella, following prolonged exposure to virus in laboratory cultures. Resistant insects exhibited reduced fitness in other respects, namely slower development and reduced egg viability, compared to control insects. These results were interpreted as pleiotropic effects of selection at the loci controlling resistance. Similar results have been described in a previous study: Fuxa & Richter (1989) used artificial selection to increase resistance to nuclear polyhedrasis virus (NPV) (Baculoviridae) infection in the moth Spodoptera frugiperda. The resulting gain in resistance they interpreted as the result of an increase in the frequency of alleles conferring resistance. Again, resistant insects exhibited maladaptive traits compared to controls, including a shorter adult life span, reduced number of eggs and reduced egg viability. In both studies the suggestion is made that selection against maladaptive traits will result in a decline in resistance, once selection for resistance is removed. Boots & Begon (1993) described a decrease in development time (towards that of control insects) within two generations of removing selection for resistance. Fuxa & Richter (1989) describe a decrease in resistance, so that within two generations of relaxing selection, previously resistant lines were not significantly more resistant than control insects. . .

Transcription factories : gene expression in unions?

Transcription is a fundamental step in gene expression, yet it remains poorly understood at a cellular level. Visualization of transcription sites and active genes has led to the suggestion that transcription occurs at discrete sites in the nucleus, termed transcription factories, where multiple active RNA polymerases are concentrated and anchored to a nuclear substructure. However, this concept is not universally accepted. This Review discusses the experimental evidence in support of the transcription factory model and the evidence that argues against such a spatially structured view of transcription. The transcription factory model has implications for the regulation of transcription initiation and elongation, for the organization of genes in the genome, for the co-regulation of genes and for genome instability.

Emotion recognition of static and dynamic faces in autism spectrum disorder

There is substantial evidence for facial emotion recognition (FER) deficits in autism spectrum disorder (ASD). The extent of this impairment, however, remains unclear, and there is some suggestion that clinical groups might benefit from the use of dynamic rather than static images. High-functioning individuals with ASD (n = 36) and typically developing controls (n = 36) completed a computerised FER task involving static and dynamic expressions of the six basic emotions. The ASD group showed poorer overall performance in identifying anger and disgust and were disadvantaged by dynamic (relative to static) stimuli when presented with sad expressions. Among both groups, however, dynamic stimuli appeared to improve recognition of anger. This research provides further evidence of specific impairment in the recognition of negative emotions in ASD, but argues against any broad advantages associated with the use of dynamic displays.

Cone Ratios in Myopia and Emmetropia: A Pilot Study

Purpose There is a suggestion that the long wavelength-sensitive (LWS)-to-middle wavelength-sensitive (MWS) cone ratio in the retina is associated with myopia. The aim was to measure the LWS/MWS amplitude modulation ratio, an estimate of the LWS/MWS cone ratio, in young adult emmetropes and myopes. Methods Multifocal visual evoked potentials were measured when the LWS and MWS cone systems were excited separately using the method of silent substitution. The 30 young adult participants (22 to 33 years) included 10 emmetropes (mean [±SD] refraction, +0.3 [±0.4] diopters [D]) and 20 myopes (mean [±SD] refraction, -3.4 [±1.7] D). Results The LWS/MWS amplitude modulation ratios ranged from 0.56 to 1.80 in the central 3- to 13-degree diameter ring and from 0.94 to 1.91 in the peripheral 13- to 30-degree diameter ring. Within the central ring, the mean (±SD) ratios were 1.20 (±0.26) and 1.20 (±0.33) for the emmetropic and the myopic groups, respectively. For the peripheral ring, the mean (±SD) ratios were 1.48 (±0.27) and 1.30 (±0.27), respectively. There were no significant differences in the ratios between the emmetropic and myopic groups for either the central (p = 0.99) or peripheral (p = 0.08) rings. For the latter, more myopic refractive error was associated with lower LWS/MWS amplitude modulation ratio; the refraction explained 16% (p = 0.02) of variation in ratio. Conclusions The relationship between the LWS/MWS amplitude modulation ratios and refraction at 13 to 30 degrees indicates that a large longitudinal study of changes in refraction in persons with known cone ratio is required to determine if a low LWS/MWS cone ratio is associated with myopia development.