920 resultados para Academic Science


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Potato leafroll virus (PLRV) is a positive-strand RNA virus that generates subgenomic RNAs (sgRNA) for expression of 3' proximal genes. Small RNA (sRNA) sequencing and mapping of the PLRV-derived sRNAs revealed coverage of the entire viral genome with the exception of four distinctive gaps. Remarkably, these gaps mapped to areas of PLRV genome with extensive secondary structures, such as the internal ribosome entry site and 5' transcriptional start site of sgRNA1 and sgRNA2. The last gap mapped to ~500. nt from the 3' terminus of PLRV genome and suggested the possible presence of an additional sgRNA for PLRV. Quantitative real-time PCR and northern blot analysis confirmed the expression of sgRNA3 and subsequent analyses placed its 5' transcriptional start site at position 5347 of PLRV genome. A regulatory role is proposed for the PLRV sgRNA3 as it encodes for an RNA-binding protein with specificity to the 5' of PLRV genomic RNA. © 2013.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The P0 protein of poleroviruses and P1 protein of sobemoviruses suppress the plant's RNA silencing machinery. Here we identified a silencing suppressor protein (SSP), P0PE, in the Enamovirus Pea enation mosaic virus-1 (PEMV-1) and showed that it and the P0s of poleroviruses Potato leaf roll virus and Cereal yellow dwarf virus have strong local and systemic SSP activity, while the P1 of Sobemovirus Southern bean mosaic virus supresses systemic silencing. The nuclear localized P0PE has no discernable sequence conservation with known SSPs, but proved to be a strong suppressor of local silencing and a moderate suppressor of systemic silencing. Like the P0s from poleroviruses, P0PE destabilizes AGO1 and this action is mediated by an F-box-like domain. Therefore, despite the lack of any sequence similarity, the poleroviral and enamoviral SSPs have a conserved mode of action upon the RNA silencing machinery. © 2012 Elsevier Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The genomic sequence of an Australian isolate of carrot mottle umbravirus (CMoV-A) was determined from cDNA generated from dsRNA. This provides the first data on the genome organization and phylogeny of an umbravirus. The 4201-nucleotide genome contains four major open reading frames (ORFs). Analysis suggests that ORF2 encodes an RNA-dependent RNA polymerase, that ORF4 encodes a movement protein, and that the virus has no coat protein gene. The functions of ORFs 1 and 3 remain unknown. ORF2 is probably translated following ribosomal frameshifting. ORFs 3 and 4 are probably translated from a subgenomic mRNA. Sequence comparisons showed CMoV-A to be closely related to pea enation mosaic RNA2 NA2), but also to have affinities with the Bromoviridae. These findings shed light on the relationships between the luteoviruses, PEMV, and the umbraviruses and on the relationships between the carmo-like viruses and the Bromoviridae.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Complementary DNAs covering the entire RNA genome of soybean dwarf luteovirus (SDV) were cloned and sequenced. Computer analysis of the 5861 nucleotide sequence revealed five major open reading frames (ORFs) possessing conservation of sequence and organisation with known luteovirus sequences. Comparative analyses of the genome structure show that SDV shares sequence homology and features of gene organisation with barley yellow dwarf virus (PAV isolate) in the 5' half of the genome, yet is more closely related to potato leafroll virus in its 3' coding regions. In addition, SDV differs from other known luteoviruses in possessing an exceptionally long 3' terminal sequence with no apparent coding capacity. We conclude from these data that the SDV genome represents a third variant genome type in the luteovirus group.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We have characterised the subgenomic RNAs of an Australian isolate of BYDV-PAV. Northern blot analyses of infected plants and protoplasts have shown that this isolate synthesises three subgenomic RNAs. Precise mapping of the transcription start sites of all three subgenomic RNAs and translational analyses of subgenomic RNA 2 and 3 have revealed a number of features. First, the transcription start site of subgenomic RNA 1 in this isolate differs markedly from the start site determined for an Illinois isolate of BYDV-PAV. Second, the start sites of subgenomic RNA 1 and 2 occur at a sequence that closely resembles the 5' end sequence of the genomic RNA (5'AGUGAAGA). Third, subgenomic RNA 2 appears to express ORF 6 of BYDV-PAV but the gene product is truncated due to the appearance of a new stop codon in the sequence. Last, subgenomic RNA 3, which is abundantly transcribed and encapsidated by the virus particle, appears to have no coding ability. We postulate that this novel subgenomic RNA has a regulatory function.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There has been growing recognition of the contribution that Sessional Academics make to student learning in higher education; with recent studies concluding that around half Australian university teaching is now performed by casual staff [Red Report 2008; May, 2013]. However, sector-wide research and institutional audits continue to raise concerns about academic development and quality assurance, as well as the recognition and retention of Sessional Academics. In response, universities offer academic development programs. However, while such centrally offered programs are undoubtedly useful, they are necessarily generic and cannot address the local contexts of faculties or provide ‘on the ground’ support. This paper presents a new, distributed model of academic support and development for Sessional academics at Queensland University of Technology. Entitled the Sessional Academic Success program, it employs the principles of distributed leadership. Experienced Sessional academics are trained and supported to assume roles as Sessional Academic Success Advisors within their schools. Complementing our central programs, they design bespoke, locally situated, peer-to-peer academic development for new Sessional teachers; provide ‘just in time’, safe and reliable advice; and build supportive communities of teaching practice in their local contexts. This distributed model re-envisages the forms and places of academic development and support. It helps ensure that new Sessional Academics are embraced by faculty life. And, recognizing that experienced Sessional Academics have much to contribute to the advancement of learning and teaching, it builds their capacity through leadership opportunities. As the designer/facilitator of the program and a Sessional Academic Success Advisor, the authors take a dialogic approach and together describe the design, implementation and outcomes of the program.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The QUT Sessional Academic Program (SAP) has scaffolded levels, each with experience-appropriate objectives: • SAP 1: Introduction to Learning and Teaching aims to develop confidence and build awareness of pedagogy and managing class-room scenarios. • SAP 2: Learning and Teaching in Large Units focuses on aligning curriculum and assessment through learning activities and builds a community of teaching practice with sessionals and subject coordinators. • SAP 3: Developing your Teaching Practice focuses on whole of university and classroom strategies to ensure student success through effective feedback; reflective practice and learning communities. • SAP 4: Enhancing your Teaching Practice applies these factors to teaching success. In conjunction with: • Sessional Career Advancement Development: for Higher Degree Research students/ sessional staff who aspire to become academics provides guidance on developing an academic portfolio in teaching, research and service. And • Sessional Academic Success program providing ongoing, local support (see separate nomination). A critical factor in its success is its praxis approach. Theoretical principles are modelled. Eg, ‘active learning’ is explained and modelled through learning activities, which participants evaluate ‘on the fly’ against the criteria of learning, engagement and connection with peers. The topics ‘learning communities’ and ‘reflective practice’ are explored as a learning community–then applied in participants’ classes, with reflections shared in the next session. This produces a ‘meta-awareness’ of theory and principles, as they are explained, applied in practice, and critically analysed for their effectiveness in workshops.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Building distributed leadership for effective supervision of creative practice higher research degrees is an Office for Learning and Teaching (OLT) funded project, conducted in partnership between Queensland University of Technology, The University of Melbourne, Auckland University of Technology, University of New South Wales and University of Western Sydney. The project was initiated to develop a cooperative approach to establishing an understanding of the contextual frameworks of the emergent field of creative practice higher degrees by research (HDRs); capturing early insights of administrators and supervisors; gathering exemplars of good practices; and establishing an in-common understanding of effective approaches to supervision. To this end, the project has produced: • A literature review, to provide a research foundation for creative practice higher research degree supervision (Chapter 3). • A contextual review of disciplinary frameworks for HDR programs, produced through surveys of postgraduate research administrators (Section 4.1), and an analysis of institutional materials and academic development programs for supervisors (Section 4.2). • A National Symposium, Effective Supervision of Creative Arts Research Degrees (ESCARD), at QUT in Brisbane in February 2013, with 62 delegates from 20 Australasian Universities, at which project findings were disseminated, and delegates presented case studies and position papers, and participated in discussions on key issues for supervisors (Appendix 1). • Resources, including a booklet for supervisors: 12 Principles for the Effective Supervision of Creative Practice Higher Research Degrees, which encapsulates attitudes, insights and good practices of experienced and new supervisors. It was produced through a content analysis of interviews with twenty-five supervisors in creative disciplines (visual and performing arts, music, new media, creative writing and design) (Printed booklet, PDF, Appendix 3). • A project website to disseminate project outcomes , which holds project findings, relevant references, and a repository of case studies and position papers by supervisors and program administrators. • A call for papers for a special issue ‘Supervising Practice: Perspectives on the Supervision of Creative Practice Research Higher Degrees’ of ACCESS Journal: Critical Perspectives on Communication, Cultural & Policy Studies (ERA ranked A quality) in 2014 (Appendix 2). • A community of supervisory practice initiated through project partnerships, a national symposium where supervisors from across Australasia met in dialogue for the first time, resource sharing, and joint publishing opportunities. • A set of recommendations for supervision capacity building and academic development, produced through the triangulation of literature and contextual reviews, analysis of institutional frameworks, interviews with supervisors and national dialogues. It is anticipated that the project’s outcomes will support experienced and new supervisors in this emergent field, and so benefit HDR students, and will enable creative disciplines to build supervision capacity, and so to accommodate growth in postgraduate enrolments. Funded as a pilot project, the project set out to establish a robust research base to provide a foundation for future work involving sharing good practices, resource building, and designing effective approaches to academic development for supervisors. Recommendations that were produced out of this project include the need to extend beyond generic, formal training for supervisors to academic development that harnesses and extends distributed leadership; focuses on local, disciplinary contexts; has a strong emphasis on case studies; provides diverse resources; and facilitates dialogue between supervisors. Recommendations also include developing frameworks for mentoring new supervisors and building a national network to facilitate cross-institutional discourse, disseminate good practices, and share insights into the management of risk factors, ethical issues, and preparing candidates for examination. As a pilot investigation, the outcomes of this project lay the ground for this future work.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A full-length cDNA clone of barley yellow dwarf virus (BYDV-PAV serotype) has been constructed and fused to the bacteriophage T7 RNA polymerase promoter. RNA transcripts produced in vitro, either capped or uncapped, were infectious in Triticum monococcum protoplasts. Protoplasts inoculated with in vitro-transcribed BYDV RNA accumulated coat protein, synthesized new viral RNAs, and produced virus particles. Aphid feeding on extracts from protoplasts inoculated with in vitro RNA transcripts can be used to transfer the virus progeny to whole plants. Introduction of mutations which interrupt specific BYDV-PAV open reading frames (ORFs) V and VI eliminated infectivity while an ORF I mutant remained infectious. Infectious RNA transcripts derived from BYDV cDNA clones will facilitate analysis of the molecular aspects of BYDV infection and further enhance our understanding of this economically important virus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The nucleotide sequence of the coat protein gene of barley yellow dwarf virus (BYDV, PAV serotype) was determined, and the amino acid sequence was deduced. The open reading frame, encoding a protein of relative molecular mass (Mr) 22,047, was confirmed as the coat protein gene by comparison with amino acid sequences of tryptic peptides derived from dissociated virions. In addition, a fragment of this gene expressed in Escherichia coli produced a product which was recognized by antibodies prepared against purified BYDV virions. An overlapping reading frame encoding an Mr 17,147 protein is contained completely within the coat protein gene. © 1988.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents a vulnerability within the generic object oriented substation event (GOOSE) communication protocol. It describes an exploit of the vulnerability and proposes a number of attack variants. The attacks sends GOOSE frames containing higher status numbers to the receiving intelligent electronic device (IED). This prevents legitimate GOOSE frames from being processed and effectively causes a hijacking of the communication channel, which can be used to implement a denial–of–service (DoS) or manipulate the subscriber (unless a status number roll-over occurs). The authors refer to this attack as a poisoning of the subscriber. A number of GOOSE poisoning attacks are evaluated experimentally on a test bed and demonstrated to be successful.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Modicon Communication Bus (Modbus) protocol is one of the most commonly used protocols in industrial control systems. Modbus was not designed to provide security. This paper confirms that the Modbus protocol is vulnerable to flooding attacks. These attacks involve injection of commands that result in disrupting the normal operation of the control system. This paper describes a set of experiments that shows that an anomaly-based change detection algorithm and signature-based Snort threshold module are capable of detecting Modbus flooding attacks. In comparing these intrusion detection techniques, we find that the signature-based detection requires a carefully selected threshold value, and that the anomaly-based change detection algorithm may have a short delay before detecting the attacks depending on the parameters used. In addition, we also generate a network traffic dataset of flooding attacks on the Modbus control system protocol.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objectives The intent of this paper is in the examination of health IT implementation processes – the barriers to and facilitators of successful implementation, identification of a beginning set of implementation best practices, the identification of gaps in the health IT implementation body of knowledge, and recommendations for future study and application. Methods A literature review resulted in the identification of six health IT related implementation best practices which were subsequently debated and clarified by participants attending the NI2012 Research Post Conference held in Montreal in the summer of 2012. Using the framework for implementation research (CFIR) to guide their application, the six best practices were applied to two distinct health IT implementation studies to assess their applicability. Results Assessing the implementation processes from two markedly diverse settings illustrated both the challenges and potentials of using standardized implementation processes. In support of what was discovered in the review of the literature, “one size fits all” in health IT implementation is a fallacy, particularly when global diversity is added into the mix. At the same time, several frameworks show promise for use as “scaffolding” to begin to assess best practices, their distinct dimensions, and their applicability for use. Conclusions Health IT innovations, regardless of the implementation setting, requires a close assessment of many dimensions. While there is no “one size fits all”, there are commonalities and best practices that can be blended, adapted, and utilized to improve the process of implementation. This paper examines health IT implementation processes and identifies a beginning set of implementation best practices, which could begin to address gaps in the health IT implementation body of knowledge.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper reports on a Professional Learning Programme undertaken by primary school teachers in China that aimed to facilitate the development of ‘adaptive expertise’ in using technology to facilitate innovative science teaching and learning such as that envisaged by the Chinese Ministry of Education’s (2010–2020) education reforms. The study found that the participants made substantial progress towards the development of adaptive expertise manifested not only by advances in the participants’ repertoires of pedagogical content knowledge but also in changes to their levels of confidence and identities as teachers. By the end of the programme, the participants had coalesced into a professional learning community that readily engaged in the sharing, peer review, reuse and adaption, and collaborative design of innovative science learning and assessment activities. The findings from the study indicate that those engaged in the development of Professional Learning Programmes in Asia-Pacific nations need to take cognizance of certain cultural factors and traditions idiosyncratic to the educational systems. This is reflected in the amended set of principles to inform the design and implementation of professional learning programmes presented in the concluding sections of the paper.