150 research outputs found

    Sexual reproduction is the null hypothesis for life cycles of rust fungi

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    Sexual reproduction, mutation, and reassortment of nuclei increase genotypic diversity in rust fungi. Sexual reproduction is inherent to rust fungi, coupled with their coevolved plant hosts in native pathosystems. Rust fungi are hypothesised to exchange nuclei by somatic hybridisation with an outcome of increased genotypic diversity, independent of sexual reproduction. We provide criteria to demonstrate whether somatic exchange has occurred, including knowledge of parental haplotypes and rejection of fertilisation in normal rust life cycles

    Dietary, lifestyle and clinicopathological factors associated with BRAF and K-ras mutations arising in distinct subsets of colorectal cancers in the EPIC Norfolk study.

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    BACKGROUND: BRAF and K-ras proto-oncogenes encode components of the ERK signalling pathway and are frequently mutated in colorectal cancer. This study investigates the associations between BRAF and K-ras mutations and clinicopathological, lifestyle and dietary factors in colorectal cancers. METHODS: 186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for BRAF and K-ras mutations. Diet and lifestyle data were collected prospectively using seven day food diaries. RESULTS: BRAF V600E mutation was found in 15.6% of colorectal cancers but at higher frequencies in cancers with proximal location, poor differentiation and microsatellite instability (MSI) (all p < 0.001). K-ras mutation (mostly in codons 12 and 13) was found in 22.0% of colorectal cancers but at higher frequencies in cancers of more advanced Dukes' stage (p = 0.001), microsatellite stable (MSS) status (p = 0.002) and in individuals with lower blood high-density lipoprotein concentrations (p = 0.04). Analysis of dietary factors demonstrated no link between BRAF mutation and any specific dietary constituent, however, K-ras mutation was found at higher frequencies in individuals with higher white meat consumption (p < 0.001). Further analysis of specific mutation type demonstrated that G to A transitions in K-ras were observed at higher frequencies in individuals consuming lower amounts of fruit (p = 0.02). CONCLUSION: These data support the model of BRAF and K-ras mutations arising in distinct colorectal cancer subsets associated with different clinicopathological and dietary factors, acting as mutually exclusive mechanisms of activation of the same signalling pathway.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Alterations in PTEN and PIK3CA in colorectal cancers in the EPIC Norfolk study: associations with clinicopathological and dietary factors.

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    BACKGROUND: The PTEN tumour suppressor gene and PIK3CA proto-oncogene encode proteins which contribute to regulation and propagation of signal transduction through the PI3K/AKT signalling pathway. This study investigates the prevalence of loss of PTEN expression and mutations in both PTEN and PIK3CA in colorectal cancers (CRC) and their associations with tumour clinicopathological features, lifestyle factors and dietary consumptions. METHODS: 186 adenocarcinomas and 16 adenomas from the EPIC Norfolk study were tested for PTEN and PIK3CA mutations by DNA sequencing and PTEN expression changes by immunohistochemistry. Dietary and lifestyle data were collected prospectively using seven day food diaries and lifestyle questionnaires. RESULTS: Mutations in exons 7 and 8 of PTEN were observed in 2.2% of CRC and PTEN loss of expression was identified in 34.9% CRC. Negative PTEN expression was associated with lower blood low-density lipoprotein concentrations (p = 0.05). PIK3CA mutations were observed in 7% of cancers and were more frequent in CRCs in females (p = 0.04). Analysis of dietary intakes demonstrated no link between PTEN expression status and any specific dietary factor. PTEN expression negative, proximal CRC were of more advanced Dukes' stage (p = 0.02) and poor differentiation (p < 0.01). Testing of the prevalence of PIK3CA mutations and loss of PTEN expression demonstrated that these two events were independent (p = 0.55). CONCLUSION: These data demonstrated the frequent occurrence (34.9%) of PTEN loss of expression in colorectal cancers, for which gene mutations do not appear to be the main cause. Furthermore, dietary factors are not associated with loss of PTEN expression. PTEN expression negative CRC were not homogenous, as proximal cancers were associated with a more advanced Dukes' stage and poor differentiation, whereas distal cancers were associated with earlier Dukes' stage.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Developmental Context Determines Latency of MYC-Induced Tumorigenesis

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    One of the enigmas in tumor biology is that different types of cancers are prevalent in different age groups. One possible explanation is that the ability of a specific oncogene to cause tumorigenesis in a particular cell type depends on epigenetic parameters such as the developmental context. To address this hypothesis, we have used the tetracycline regulatory system to generate transgenic mice in which the expression of a c-MYC human transgene can be conditionally regulated in murine hepatocytes. MYC's ability to induce tumorigenesis was dependent upon developmental context. In embryonic and neonatal mice, MYC overexpression in the liver induced marked cell proliferation and immediate onset of neoplasia. In contrast, in adult mice MYC overexpression induced cell growth and DNA replication without mitotic cell division, and mice succumbed to neoplasia only after a prolonged latency. In adult hepatocytes, MYC activation failed to induce cell division, which was at least in part mediated through the activation of p53. Surprisingly, apoptosis is not a barrier to MYC inducing tumorigenesis. The ability of oncogenes to induce tumorigenesis may be generally restrained by developmentally specific mechanisms. Adult somatic cells have evolved mechanisms to prevent individual oncogenes from initiating cellular growth, DNA replication, and mitotic cellular division alone, thereby preventing any single genetic event from inducing tumorigenesis

    Evaluation of multi-level social learning for sustainable landscapes: perspective of a development initiative in Bergslagen, Sweden

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    To implement policies about sustainable landscapesand rural development necessitates social learningabout states and trends of sustainability indicators, normsthat define sustainability, and adaptive multi-level governance.We evaluate the extent to which social learning atmultiple governance levels for sustainable landscapesoccur in 18 local development initiatives in the network ofSustainable Bergslagen in Sweden. We mapped activitiesover time, and interviewed key actors in the network aboutsocial learning. While activities resulted in exchange ofexperiences and some local solutions, a major challengewas to secure systematic social learning and make newknowledge explicit at multiple levels. None of the developmentinitiatives used a systematic approach to securesocial learning, and sustainability assessments were notmade systematically. We discuss how social learning canbe improved, and how a learning network of developmentinitiatives could be realized

    Responsive Operations for Key Services (ROKS): A Modular, Low SWaP Quantum Communications Payload

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    Quantum key distribution (QKD) is a theoretically proven future-proof secure encryption method that inherits its security from fundamental physical principles. With a proof-of-concept QKD payload having flown on the Micius satellite since 2016, efforts have intensified globally. Craft Prospect, working with a number of UK organisations, has been focused on miniaturising the technologies that enable QKD so that they may be used in smaller platforms including nanosatellites. The significant reduction of size, and therefore the cost of launching quantum communication technologies either on a dedicated platform or hosted as part of a larger optical communications will improve potential access to quantum encryption on a relatively quick timescale. The Responsive Operations for Key Services (ROKS) mission seeks to be among the first to send a QKD payload on a CubeSat into low Earth orbit, demonstrating the capabilities of newly developed modular quantum technologies. The ROKS payload comprises a quantum source module that supplies photons randomly in any of four linear polarisation states fed from a quantum random number generator; an acquisition, pointing, and tracking system to fine-tune alignment of the quantum source beam with an optical ground station; an imager that will detect cloud cover autonomously; and an onboard computer that controls and monitors the other modules, which manages the payload and assures the overall performance and security of the system. Each of these modules have been developed with low Size, Weight and Power (SWaP) for CubeSats, but with interoperability in mind for other satellite form factors. We present each of the listed components, together with the initial test results from our test bench and the performance of our protoflight models prior to initial integration with the 6U CubeSat platform systems. The completed ROKS payload will be ready for flight at the end of 2022, with various modular components already being baselined for flight and integrated into third party communication missions

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Assembly, assessment and availability of de novo generated transcriptomes

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    De novo assembly of a complete transcriptome without the need for a guiding reference genome is attractive, particularly where the cost and complexity of generating a eukaryote genome is prohibitive. The transcriptome should not however be seen as just a quick and cheap alternative to building a complete genome. Transcriptomics allows the understanding and comparison of spatial and temporal samples within an organism and allows surveying of multiple individuals or closely related species. De novo assembly in theory allows the building of a complete transcriptome without any prior knowledge of the genome it also allows the discovery of alternate splice forms of coding RNAs and also non-coding RNAs, which are often missed by proteomic approaches or are incompletely annotated in genome studies. The limitations of the method are that generation of a truly complete assembly is unlikely and so we require some method for assessment of the quality and appropriateness of a generated transcriptome. Whilst no single consensus pipeline or tools is agreed as optimal, various algorithms and easy to use software do exist making transcriptome generation a more common approach. With this expansion of data, questions still exist relating to how do we make these datasets fully discoverable, comparable and most useful to understand complex biological systems

    Crop Updates 2004 - Cereals

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    This session covers twenty eight papers from different authors: PLENARY 1. Declining profitability in continuous cropping systems. Is more wheat the answer on Duplex soil? Dr Wal Anderson, Department of Agriculture 2. Disease implications of extending the wheat phase in low-medium rainfall areas, Dr Vivian Vanstone and Dr Robert Loughman, Department of Agriculture 3. Prolonged wheat phase on duplex soils – where do weeds set the boundary? Vanessa Stewart, Department of Agriculture WHEAT AGRONOMY 4. Management of small grain screenings in wheat, Dr Wal Anderson and Dr Darshan Sharma, Department of Agriculture 5. Agronomic responses of new wheat varieties, Christine Zaicou-Kunesch, Dr Darshan Sharma, Brenda Shackley, Dr Mohammad Amjad, Dr Wal Anderson and Steve Penny,Department of Agriculture 6. Managing wheat yield reduction from wide rows, Dr Mohammad Amjad and Dr Wal Anderson, Department of Agriculture 7. Row spacing and stubble effect on wheat yield and ryegrass seed set, Glen Riethmuller, Department of Agriculture 8. Grain protein management – lessons learnt on the south coast, Jeremy Lemon, Department of Agriculture 9. Unravelling the mysteries of optimum seed rates, Dr Wal Anderson, Dr Darshan Sharma, Brenda Shackley and Mario D’Antuono, Department of Agriculture 10. Agronomic features for growing better wheat – south east agricultural region 2003, Dr Mohammad Amjad, Veronika Reck and Ben Curtis, Department of Agriculture 11. Agronomic responses of new wheat varieties – great southern agricultural region 2003, Brenda Shackley and Judith Devenish, Department of Agriculture 12. Variety specific responses of new wheat varieties – central agricultural region 2003, Dr Darshan Sharma and Dr Wal Anderson, Department of Agriculture 13. Agronomic responses of new wheat varieties – northern agricultural region 2003, Christine Zaicou-Kunesch, Melaine Kupsch and Anne Smith, Department of Agriculture BARLEY AND OAT AGRONOMY 14. Gairdner for high rainfall – where does Baudin fit in? Blakely Paynter, Roslyn Jettnerand Leanne Schulz, Department of Agriculture 15. Oaten hay – varieties and agronomy, Blakely Paynter, Jocelyn Ball and Tom Sweeny, Department of Agriculture NUTRITION 16. In-furrow fungicide applications in liquid fertiliser, Dr Stephen Loss, CSBP Ltd 17. Elemental sulphur as a fertiliser source in Western Australia, Ashleigh Brooks1A, Justin Fuery2, Geoff Anderson3 and Prof Zed Rengel1,1UWA, 2Summit FertilizerFertilisers and 3Department of Agriculture 18. Genetic variation in potassium efficiency of barley, Paul Damon and Prof. Zed Rengel, Faculty of Natural and Agricultural Sciences, UWA 19. Managing protein through strategic N applications, Eddy Pol and Dr Stephen Loss, CSBP Ltd 20. Nitrogen management for wheat in high rainfall cropping areas, Narelle Hill1, Ray Tugwell1, Dr Wal Anderson1, Ron McTaggart1and Nathan Moyes2, 1Department of Agriculture and 2Landmark 21. Flag smut resistance in current WA wheat varieties, John Majewski and Dr Manisha Shankar, Department of Agriculture 22. Rust resistance update for wheat varieties in WA, Dr Manisha Shankar, John Majewski and Jamie Piotrowski, Department of Agriculture PESTS AND DISEASES 23. Stripe rust in WA – where was it and what can we learn from 2003? Dr Robert Loughman and Ciara Beard, Department of Agriculture 24. Foliar disease management – a key factor in the adoption of Baudin and Hamlin barley, Dr Kithsiri Jayasena, Dr Rob Loughman, Kazue Tanaka and Grey Poulish, Department of Agriculture 25. Validating aphid and virus risk forecasts for cereals, Dr Debbie Thackray, Rohan Prince and Dr Roger Jones, Department of Agriculture and Centre for Legumes in Mediterranean Agriculture HARVESTING 26. Swathing Gairdner barley at 30% moisture, Peter NelsonÂč and Nigel MetzÂČ, ÂčCooperative Bulk Handling and ÂČ Fitzgerald Biosphere Group MODELLING 27. Development of a web based grower decision aid application for cereal growers, Dr Leisa Armstrong1, Yee Leong (Alex) Yung1and Dr Moin Salam2 1School of Computer and Information Science, Edith Cowan University; and 2Department of Agriculture 28. Wheat varieties updated in ‘Flowering Calculator’ – a model predicting flowering time, Brenda Shackley, Dr David Tennant, Dr Darshan Sharma and Christine Zaicou‑Kunesch, Department of Agricultur
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