997 resultados para Philosophy, Ancient


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An open question amongst papillomavirus taxonomists is whether recombination has featured in the evolutionary history of these viruses. Since the onset of the global AIDS epidemic, the question is somewhat less academic, because immune-compromised human immunodeficiency virus patients are often co-infected with extraordinarily diverse mixtures of human papillomavirus (HPV) types. It is expected that these conditions may facilitate the emergence of HPV recombinants, some of which might have novel pathogenic properties. Here, a range of rigorous analyses is applied to full-genome sequences of papillomaviruses to provide convincing statistical and phylogenetic evidence that evolutionarily relevant papillomavirus recombination can occur. © 2006 SGM.

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Background. We have characterised a new highly divergent geminivirus species, Eragrostis curvula streak virus (ECSV), found infecting a hardy perennial South African wild grass. ECSV represents a new genus-level geminivirus lineage, and has a mixture of features normally associated with other specific geminivirus genera. Results. Whereas the ECSV genome is predicted to express a replication associated protein (Rep) from an unspliced complementary strand transcript that is most similar to those of begomoviruses, curtoviruses and topocuviruses, its Rep also contains what is apparently a canonical retinoblastoma related protein interaction motif such as that found in mastreviruses. Similarly, while ECSV has the same unusual TAAGATTCC virion strand replication origin nonanucleotide found in another recently described divergent geminivirus, Beet curly top Iran virus (BCTIV), the rest of the transcription and replication origin is structurally more similar to those found in begomoviruses and curtoviruses than it is to those found in BCTIV and mastreviruses. ECSV also has what might be a homologue of the begomovirus transcription activator protein gene found in begomoviruses, a mastrevirus-like coat protein gene and two intergenic regions. Conclusion. Although it superficially resembles a chimaera of geminiviruses from different genera, the ECSV genome is not obviously recombinant, implying that the features it shares with other geminiviruses are those that were probably present within the last common ancestor of these viruses. In addition to inferring how the ancestral geminivirus genome may have looked, we use the discovery of ECSV to refine various hypotheses regarding the recombinant origins of the major geminivirus lineages. © 2009 Varsani et al; licensee BioMed Central Ltd.

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This article assesses undergraduate teaching students’ assertion that there are no right and wrong answers in teaching philosophy. When asked questions about their experiences of philosophy in the classroom for primary children, their unanimous declaration that teaching philosophy has ‘no right and wrong answers’ is critically examined across the three sub-disciplinary areas to which they were generally referring, namely, pedagogy, ethics, and epistemology. From a pedagogical point of view, it is argued that some teaching approaches may indeed be more effective than others, and some pupils’ opinions less defensible, but pedagogically, in terms of managing the power relations in the classroom, it is counter-productive to continually insist on notions of truth and falsity at every point. From an ethical point of view, it is contended that anti-realist approaches to meta-ethics may represent a viable intellectual position, but from the point of view of normative ethics, notions of right and wrong still retain significant currency. From an epistemological point of view, it is argued using Karl Poppers’ work that while it may be difficult to determine what constitutes a right answer, determining a wrong one is far more straightforward. In conclusion, it is clear that prospective teachers engaging in philosophy in the classroom, and also future teachers in general, require a far more nuanced philosophical understanding of the notions of right and wrong and truth and falsity. In view of this situation, it we wish to promote the effective teaching of philosophical thinking to children, or produce educators who can understand the conceptual limits of the claims they make and their very real and often serious practical and social consequences, it is recommended that philosophy be reinstated to a fundamental, foundational place within the pre-service teaching curriculum.

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Chlamydia pneumoniae is an enigmatic human and animal pathogen. Originally discovered in association with acute human respiratory disease, it is now associated with a remarkably wide range of chronic diseases as well as having a cosmopolitan distribution within the animal kingdom. Molecular typing studies suggest that animal strains are ancestral to human strains and that C. pneumoniae crossed from animals to humans as the result of at least one relatively recent zoonotic event. Whole genome analyses appear to support this concept – the human strains are highly conserved whereas the single animal strain that has been fully sequenced has a larger genome with several notable differences. When compared to the other, better known chlamydial species that is implicated in human infection, Chlamydia trachomatis, C. pneumoniae demonstrates pertinent differences in its cell biology, development, and genome structure. Here, we examine the characteristic facets of C. pneumoniae biology, offering insights into the diversity and evolution of this silent and ancient pathogen.

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In Syddall v National Mutual Life Association of Australasia Limited [2008] QSC 101 Daubney J ordered the action be tried without a jury. His judgment considered the circumstances in which a trial involves any technical, scientific or other issue that can not be “conveniently” considered and resolved by a jury as provided in r 474 of the Uniform Civil Procedure Rules 1999 (Qld)

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The sheep (Ovis aries) is commonly used as a large animal model in skeletal research. Although the sheep genome has been sequenced there are still only a limited number of annotated mRNA sequences in public databases. A complementary DNA (cDNA) library was constructed to provide a generic resource for further exploration of genes that are actively expressed in bone cells in sheep. It was anticipated that the cDNA library would provide molecular tools for further research into the process of fracture repair and bone homeostasis, and add to the existing body of knowledge. One of the hallmarks of cDNA libraries has been the identification of novel genes and in this library the full open reading frame of the gene C12orf29 was cloned and characterised. This gene codes for a protein of unknown function with a molecular weight of 37 kDa. A literature search showed that no previous studies had been conducted into the biological role of C12orf29, except for some bioinformatics studies that suggested a possible link with cancer. Phylogenetic analyses revealed that C12orf29 had an ancient pedigree with a homologous gene found in some bacterial taxa. This implied that the gene was present in the last common eukaryotic ancestor, thought to have existed more than 2 billion years ago. This notion was further supported by the fact that the gene is found in taxa belonging to the two major eukaryotic branches, bikonts and unikonts. In the bikont supergroup a C12orf29-like gene was found in the single celled protist Naegleria gruberi, whereas in the unikont supergroup, encompassing the metazoa, the gene is universal to all chordate and, therefore, vertebrate species. It appears to have been lost to the majority of cnidaria and protostomes taxa; however, C12orf29-like genes have been found in the cnidarian freshwater hydra and the protostome Pacific oyster. The experimental data indicate that C12orf29 has a structural role in skeletal development and tissue homeostasis, whereas in silico analysis of the human C12orf29 promoter region suggests that its expression is potentially under the control of the NOTCH, WNT and TGF- developmental pathways, as well SOX9 and BAPX1; pathways that are all heavily involved in skeletogenesis. Taken together, this investigation provides strong evidence that C12orf29 has a very important role in the chordate body plan, in early skeletal development, cartilage homeostasis, and also a possible link with spina bifida in humans.

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An Interview with Sylvère Lotringer, Jean Baudrillard Chair at the European Graduate School and Professor Emeritus of French Literature and Philosophy at Columbia University, on the Architectural Contribution to Semiotext(e), Schizoculture, and the Early Deleuze and Guattari Scene at Columbia University, which took place at the Department of French, Columbia University, New York City, July 2003. This interview exists as an audio cassette tape recording.

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Using epistemic perspectives as a theoretical framework, this study investigated Australian pre-service teachers’ perspectives about knowing, knowledge and children’s learning, as they engaged in a semester-long unit on philosophy in the classroom. During the field experience component of the unit, pre-service teachers were required to teach at least one philosophy lesson. Pre-service teachers completed the Personal Epistemological Beliefs Survey at the beginning and end of the unit. They were also interviewed in focus groups at the end of the semester to investigate their views about children’s learning. Paired sample t-tests were used to explore changes in epistemic beliefs over time. Significant differences were found for only some individual items on the survey. However, when interviewed, pre-service teachers indicated that field experiences helped them consider children as competent ‘thinkers’ who were capable of engaging in philosophy in the classroom. They reported predominantly student-centred perspectives of children’s learning, although a process of adjudication (exploring disagreements and evidence for responses) was lacking in these responses.

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A new form of media installation combining image, multi-channel sound and internally lit objects into a mysterious, deep image plane. Staged on the very edge of spectrum blackout, and moving into the deep of night, Version 1 (Night Rage) for ISEA 2013 examined the many shades of 'nocturnal', threats to night biodiversity and the myriad myths and stories that have shaped our cultural understandings of life after light. Barely recognisable images float within landscapes of media, noise and sound as the work asserts a profound resistance to today's all consuming media mesh. Version 2 (Night Fall) for the Queensland State Museum examined contemporary ideas around the ‘night’ and the 'nocturnal'. Beginning with the dark myths and stories that have long shaped our cultural understandings of life after light, NIGHT FALL considers how fearful ideas have often underpinned actions that continue to reduce Australia’s extraordinary night biodiversity. Today’s growing hostility towards Australia’s ancient, iconic flying foxes - who have been quietly pollinating our forests for millennia - hints at just how far we have yet to travel in our thinking. Enter the darkened tunnel to experience mysterious, edge-of-perception 3D forms, enhanced by a range of cinematic, illusionary and animatronic techniques, and become immersed in a strangely familiar sound track based upon seasonal field recordings made after dark, sourced from across the eastern coast of Queensland.

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Anthocyanin accumulation is coordinated in plants by a number of conserved transcription factors. In apple (Malus × domestica), an R2R3 MYB transcription factor has been shown to control fruit flesh and foliage anthocyanin pigmentation (MYB10) and fruit skin color (MYB1). However, the pattern of expression and allelic variation at these loci does not explain all anthocyanin-related apple phenotypes. One such example is an open-pollinated seedling of cv Sangrado that has green foliage and develops red flesh in the fruit cortex late in maturity. We used methods that combine plant breeding, molecular biology, and genomics to identify duplicated MYB transcription factors that could control this phenotype. We then demonstrated that the red-flesh cortex phenotype is associated with enhanced expression of MYB110a, a paralog of MYB10. Functional characterization of MYB110a showed that it was able to up-regulate anthocyanin biosynthesis in tobacco (Nicotiana tabacum). The chromosomal location of MYB110a is consistent with a whole-genome duplication event that occurred during the evolution of apple within the Maloideae family. Both MYB10 and MYB110a have conserved function in some cultivars, but they differ in their expression pattern and response to fruit maturity.