540 resultados para Marcus, Brian
Resumo:
In plants, double-stranded RNA (dsRNA) is an effective trigger of RNA silencing, and several classes of endogenous small RNA (sRNA), processed from dsRNA substrates by DICER-like (DCL) endonucleases, are essential in controlling gene expression. One such sRNA class, the microRNAs (miRNAs) control the expression of closely related genes to regulate all aspects of plant development, including the determination of leaf shape, leaf polarity, flowering time, and floral identity. A single miRNA sRNA silencing signal is processed from a long precursor transcript of nonprotein-coding RNA, termed the primary miRNA (pri-miRNA). A region of the pri-miRNA is partially self-complementary allowing the transcript to fold back onto itself to form a stem-loop structure of imperfectly dsRNA. Artificial miRNA (amiRNA) technology uses endogenous pri-miRNAs, in which the miRNA and miRNA*(passenger strand of the miRNA duplex) sequences have been replaced with corresponding amiRNA/ amiRNA*sequences that direct highly efficient RNA silencing of the targeted gene. Here, we describe the rules for amiRNA design, as well as outline the PCR and bacterial cloning procedures involved in the construction of an amiRNA plant expression vector to control target gene expression in Arabidopsis thaliana. © 2014 Springer Science+Business Media New York.
Resumo:
It is known that 22-nucleotide (nt) microRNAs (miRNAs) derived from asymmetric duplexes trigger phased small-interfering RNA (phasiRNA) production from complementary targets. Here we investigate the efficacy of 22-nt artificial miRNA (amiRNA)-mediated RNA silencing relative to conventional hairpin RNA (hpRNA) and 21-nt amiRNA-mediated RNA silencing. CHALCONE SYNTHASE (CHS) was selected as a target in Arabidopsis thaliana due to the obvious and non-lethal loss of anthocyanin accumulation upon widespread RNA silencing. Over-expression of CHS in the pap1-D background facilitated visual detection of both local and systemic RNA silencing. RNA silencing was initiated in leaf tissues from hpRNA and amiRNA plant expression vectors under the control of an Arabidopsis RuBisCo small subunit 1A promoter (SSU). In this system, hpRNA expression triggered CHS silencing in most leaf tissues but not in roots or seed coats. Similarly, 21-nt amiRNA expression from symmetric miRNA/miRNA* duplexes triggered CHS silencing in all leaf tissues but not in roots or seed coats. However, 22-nt amiRNA expression from an asymmetric duplex triggered CHS silencing in all tissues, including roots and seed coats, in the majority of plant lines. This widespread CHS silencing required RNA-DEPENDENT RNA POLYMERASE6-mediated accumulation of phasiRNAs from the endogenous CHS transcript. These results demonstrate the efficacy of asymmetric 22-nt amiRNA-directed RNA silencing and associated phasiRNA production and activity, in mediating widespread RNA silencing of an endogenous target gene. Asymmetric 22-nt amiRNA-directed RNA silencing requires little modification of existing amiRNA technology and is expected to be effective in suppressing other genes and/or members of gene families.
Resumo:
A suite of plant expression vectors (pPLEX), constructed from the gene regulation signals from subterranean clover stunt virus (SCSV) genome, has previously been used in dicot transformation for a variety of applications in plant biotechnology. To assess their use for the transformation of monocots, a number of modifications were made to the basic vector series and assessed in rice. In their unmodified forms, the SCSV promoters directed low levels of gene expression, however, insertion of an intron between the promoter and the transgene open reading frame (analogous to the rice actin and maize ubiquitin promoter systems) increased transgene expression 50-fold. The expression patterns from the intron-modified SCSV (segments 4 and 7) promoters were very similar to those directed by the actin or ubiquitin promoters. All promoter systems investigated directed expression that appeared to be constitutive within leaf tissue, and localised to the epidermal and vascular tissues of the root. The pPLEX vectors described here are an important counterpart to the dicot pPLEX series and have the potential to be useful in monocot research and biotechnology.
Resumo:
The gene regulation signals from subterranean clover stunt virus (SCSV) were investigated for their expression in dicot plants. The SCSV genome has at least eight circular DNA molecules. Each circular DNA component contains a promoter element, a single open reading frame and a terminator. The promoters from seven of the segments were examined for their strength and tissue specificity in transgenic tobacco (Nicotiana tabacum L.), potato (Solanum tuberosum L.) and cotton (Gossypium hirsutum L.) using a GUS reporter gene assay system. While the promoters of many of the segments were poorly expressed, promoters derived from segments 4 and 7 were shown to direct high levels of expression in various plant tissues and organs. The segment 1 promoter directs predominantly callus-specific expression and, when used to control a selectable marker gene, facilitated the transformation of all three species (tobacco, potato and cotton). From the results, a suite of plant expression vectors (pPLEX) derived from the SCSV genome were constructed and used here to produce herbicide- and insect-resistant cotton, demonstrating their utility in the expression of foreign genes in dicot crop species and their potential for use in agricultural biotechnology.
Resumo:
This paper considers the role of the public library as a community hub, engagement space, and entrepreneurial incubator in the context of the city, city governance, and local government planning. It considers this role from the perspective of library experts and their future visions for libraries in a networked knowledge economy. Public libraries (often operated by or on behalf of local governments) potentially play a pivotal role for local governments in positioning communities within the global digital network. Fourteen qualitative interviews with library experts informed the study which investigates how the relationship between digital technology and the physical library space can potentially support the community to develop innovative, collaborative environments for transitioning to a digital future. The study found that libraries can capitalise on their position as community hubs for two purposes: first, to build vibrant community networks and forge economic links across urban localities; and second, to cross the digital divide and act as places of innovation and lifelong learning. Libraries provide a specific combination of community and technology spaces and have significant tangible connection points in the digital age. The paper further discusses the potential benefits for libraries in using ICT networks and infrastructure, such as the National Broadband Network in Australia. These networks could facilitate greater use of library assets and community knowledge, which, in turn, could assist knowledge economies and regional prosperity.
Resumo:
This paper considers an emerging planning practice that uses networked connections to interact with urban places and re-create enlivened cities. The paper presents “urban acupuncture” as a new planning approach that broadens communication and strategically targets interventions across the city. Defined as an approach, which, through the use of digital social networks and interactions, involves citizens and planners in place activations in order to stimulate and reinvigorate place, thus creating meaningful relationships between citizens and their urban settings. This paper uses the UR[BNE] Brisbane Festival 2012 as a qualitative case study of urban acupuncture, best defined as a hyper-localized healing treatment through place activation to enliven and recreate cities. It examines the challenges faced and opportunities embraced by a network of urban professionals. Their aim was to activate the underused urban spaces of central Brisbane through the festival's activities and events. The findings identify the key elements required to design public spaces using socially and technologically networked interactions.
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‘Sustainability’ provides the dominant frame within which environmental policy debate occurs, notwithstanding its divergent meanings. However, how different discourses combine to shape understanding of the environment, the causes of environmental issues, and the responses required, is less clear cut. Drawing primarily on the approach to critical discourse analysis (CDA) developed by Fairclough, this paper explores the way in which neoliberal and ecologically modern discourses combine to shape environmental policy. Environmental scholars have made relatively little use of this approach to CDA to date, despite the significant interest in the discursive aspects of environmental issues, and its wide use in other areas of policy interest. Using the case of environmental policy-making in Victoria, Australia, this paper illustrates how neoliberalism and weak ecological modernization represented sustainability in ways that seriously limited the importance of environmental issues.
Resumo:
Horror and redemption in Holocaust writing for young adults: Marcus Zusak’s The Book Thief, John Boyne’s The Boy in the Striped Pyjamas. While it has long been thought that the Holocaust is not an appropriate subject matter for young audiences, from The Diary of Anne Frank onwards it has always been part of their reading matter. Never, however, has there been so much interest as in the recent best-selling publications by Zusak and Boyne (the latter of which has been made into a film). This chapter examines the politics of crafting stories for young people about the unspeakable events of the recent past, about who has the right to ‘speak for’ the victims, and whether some genres (for example, fairy stories or fabulism) work best, given the horrific nature of the subject matter.
Resumo:
This chapter looks at the management and zoning of online sexual culture–the web sites which make up the pornosphere (McNair 2013). It explores the concept of ‘community standards’, which has been a central part of the management of sexually explicit materials in the offline world, and asks what it might mean to talk about ‘community standards’ on the Internet. And finally, it uses the concept of virtual-community standards to revisit the question of managing access to sexually explicit materials on the Internet.
Resumo:
Exceptions are an important part of the Australian copyright law landscape due to the role they play in delineating the extent of the rights held by copyright owners and, correspondingly, the permitted activities of users of copyright materials. The nature and scope of copyright exceptions has been examined in several reviews of copyright law and are again being considered by the Australian Law Reform Commission (ALRC) as part of the ‘Copyright and the Digital Economy’ review which is currently underway. The ALRC’s terms of reference require it to examine, inter alia, ‘whether the exceptions and statutory licences in the Copyright Act 1968, are adequate and appropriate in the digital environment.’ While the ALRC inquiry focuses on exceptions provided under the Copyright Act 1968 (Cth) (“Copyright Act”), there are several copyright exceptions in other Commonwealth statutes which are of relevance and which should not be overlooked.
Resumo:
EVE Online, released in 2003 by CCP Games, is a space-themed Massively Multiplayer Online Game (MMOG). This sandbox style MMOG has a reputation for being a difficult game with a punishing learning curve that is fairly impenetrable to new players. This has led to the widely held belief among the larger MMOG community that “EVE players are different”, as only a very particular type of player would be dedicated to learning how to play a game this challenging. Taking a critical approach to the claim that “EVE players are different”, this paper complicates the idea that only a certain type of player capable of playing the most hardcore of games will be attracted to this particular MMOG. Instead, we argue that EVE’s “exceptionalism” is actually the result of conscious design decisions on the part of CCP games, which in turn compel particular behaviours that are continually reinforced as the norm by the game’s relatively homogenous player community.
Resumo:
Invited Lecture for Interdisciplinary seminar, Yale School of Architecture. Seminar investigates architectural techniques of affect; topics included Adrian Stokes, Freud on aggression, Spinoza, German aesthetics, viscerality, Guattari and “concrete machines”; Other Invited guests: Peggy Deamer, Brian Massumi, Gary Genosko, Ernst Prelinger, Elizabeth Grosz, Ed Mitchell.
Resumo:
Background: Depression and alcohol misuse are among the most prevalent diagnoses in suicide fatalities. The risk posed by these disorders is exacerbated when they co-occur. Limited research has evaluated the effectiveness of common depression and alcohol treatments for the reduction of suicide vulnerability in individuals experiencing comorbidity. Methods: Participants with depressive symptoms and hazardous alcohol use were selected from two randomised controlled trials. They had received either a brief (1 session) intervention, or depression-focused cognitive behaviour therapy (CBT), alcohol-focused CBT, therapist-delivered integrated CBT, computer-delivered integrated CBT or person-centred therapy (PCT) over a 10-week period. Suicidal ideation, hopelessness, depression severity and alcohol consumption were assessed at baseline and 12-month follow-up. Results: Three hundred three participants were assessed at baseline and 12 months. Both suicidal ideation and hopelessness were associated with higher severity of depressive symptoms, but not with alcohol consumption. Suicidal ideation did not improve significantly at follow-up, with no differences between treatment conditions. Improvements in hopelessness differed between treatment conditions; hopelessness improved more in the CBT conditions compared to PCT and in single-focused CBT compared to integrated CBT. Limitations: Low retention rates may have impacted on the reliability of our findings. Combining data from two studies may have resulted in heterogeneity of samples between conditions. Conclusions: CBT appears to be associated with reductions in hopelessness in people with co-occurring depression and alcohol misuse, even when it is not the focus of treatment. Less consistent results were observed for suicidal ideation. Establishing specific procedures or therapeutic content for clinicians to monitor these outcomes may result in better management of individuals with higher vulnerability for suicide.
Resumo:
Tobacco use is a major public health concern, and is associated with a number of mental illnesses as well as increased alcohol/other drug (AOD). Research into treatment for individuals experiencing such comorbidities is limited. Participants (n = 447) were those enrolled in the Depression and Alcohol Integrated and Single-focused Interventions project (Baker et al. 2010), and the Self Help for Alcohol/other drugs and DEpression project (Kay-Lambkin et al. Medical Journal of Australia 195:S44-S50, 2011a, Journal of Medical Internet Research 13(1):e11p11, b), who reported current depression and hazardous alcohol use at entry to the study. Smoking cessation was not targeted in, nor a goal of, treatment. After controlling for socioeconomic variables, tobacco use was not associated with higher levels of depressive symptoms at baseline; however heavy smokers (30+ cigarettes per day) consumed significantly more alcohol at baseline than did non-smokers (13 vs. 9 standard drinks per day). Baseline smoking severity did not impact on depression or alcohol use outcomes over a 12-month period. Reductions in tobacco use between baseline and 3-month follow-up were significantly associated with reductions in depression and alcohol consumption over the same time period. The study results suggest that tobacco use does not interfere with treatment for depression and alcohol use problems, and adds weight to the idea of considering specific treatment for tobacco use in the context of treatment for alcohol/other drug use.
Resumo:
Language and Mobility is the latest monograph by Alastair Pennycook. It is part of the series, Critical Language and Literacy Studies. Co-edited by Pennycook, along with Brian Morgan and Ryuko Kubota, the series looks at relations of power in diverse worlds of language and literacy. As the title indicates, Pennycook’s own volume explores the idea of language turning up in ‘unexpected’ places, for example, Cornish in Moonta, South Australia, a century or two after it supposedly died with its last speaker. Why is it, Pennycook asks, that we expect to find a (particular form of a) language in a particular place? This question is generated by a critical project that seeks to leverage the educational potential of everyday moments of language use...