258 research outputs found

    Escargot maintains stemness and suppresses differentiation in Drosophila intestinal stem cells

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    Snail family transcription factors are expressed in various stem cell types, but their function in maintaining stem cell identity is unclear. In the adult Drosophila midgut, the Snail homolog Esg is expressed in intestinal stem cells (ISCs) and their transient undifferentiated daughters, termed enteroblasts (EB). We demonstrate here that loss of esg in these progenitor cells causes their rapid differentiation into enterocytes (EC) or entero‐endocrine cells (EE). Conversely, forced expression of Esg in intestinal progenitor cells blocks differentiation, locking ISCs in a stem cell state. Cell type‐specific transcriptome analysis combined with Dam‐ID binding studies identified Esg as a major repressor of differentiation genes in stem and progenitor cells. One critical target of Esg was found to be the POU‐domain transcription factor, Pdm1, which is normally expressed specifically in differentiated ECs. Ectopic expression of Pdm1 in progenitor cells was sufficient to drive their differentiation into ECs. Hence, Esg is a critical stem cell determinant that maintains stemness by repressing differentiation‐promoting factors, such as Pdm1

    Pink1 and Parkin regulate Drosophila intestinal stem cell proliferation during stress and aging.

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    Intestinal stem cells (ISCs) maintain the midgut epithelium in Drosophila melanogaster Proper cellular turnover and tissue function rely on tightly regulated rates of ISC division and appropriate differentiation of daughter cells. However, aging and epithelial injury cause elevated ISC proliferation and decreased capacity for terminal differentiation of daughter enteroblasts (EBs). The mechanisms causing functional decline of stem cells with age remain elusive; however, recent findings suggest that stem cell metabolism plays an important role in the regulation of stem cell activity. Here, we investigate how alterations in mitochondrial homeostasis modulate stem cell behavior in vivo via RNA interference-mediated knockdown of factors involved in mitochondrial dynamics. ISC/EB-specific knockdown of the mitophagy-related genes Pink1 or Parkin suppresses the age-related loss of tissue homeostasis, despite dramatic changes in mitochondrial ultrastructure and mitochondrial damage in ISCs/EBs. Maintenance of tissue homeostasis upon reduction of Pink1 or Parkin appears to result from reduction of age- and stress-induced ISC proliferation, in part, through induction of ISC senescence. Our results indicate an uncoupling of cellular, tissue, and organismal aging through inhibition of ISC proliferation and provide insight into strategies used by stem cells to maintain tissue homeostasis despite severe damage to organelles

    Helping someone with problem drinking: Mental health first aid guidelines - a Delphi expert consensus study

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    Background Alcohol is a leading risk factor for avoidable disease burden. Research suggests that a drinker's social network can play an integral role in addressing hazardous (i.e., high-risk) or problem drinking. Often however, social networks do not have adequate mental health literacy (i.e., knowledge about mental health problems, like problem drinking, or how to treat them). This is a concern as the response that a drinker receives from their social network can have a substantial impact on their willingness to seek help. This paper describes the development of mental health first aid guidelines that inform community members on how to help someone who may have, or may be developing, a drinking problem (i.e., alcohol abuse or dependence). Methods A systematic review of the research and lay literature was conducted to develop a 285-item survey containing strategies on how to help someone who may have, or may be developing, a drinking problem. Two panels of experts (consumers/carers and clinicians) individually rated survey items, using a Delphi process. Surveys were completed online or via postal mail. Participants were 99 consumers, carers and clinicians with experience or expertise in problem drinking from Australia, Canada, Ireland, New Zealand, the United Kingdom, and the United States. Items that reached consensus on importance were retained and written into guidelines. Results The overall response rate across all three rounds was 68.7% (67.6% consumers/carers, 69.2% clinicians), with 184 first aid strategies rated as essential or important by ≄80% of panel members. The endorsed guidelines provide guidance on how to: recognize problem drinking; approach someone if there is concern about their drinking; support the person to change their drinking; respond if they are unwilling to change their drinking; facilitate professional help seeking and respond if professional help is refused; and manage an alcohol-related medical emergency. Conclusion The guidelines provide a consensus-based resource for community members seeking to help someone with a drinking problem. Improving community awareness and understanding of how to identify and support someone with a drinking problem may lead to earlier recognition of problem drinking and greater facilitation of professional help seeking

    Band line-up investigation of atomic layer deposited TiAlO and GaAlO on GaN

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    A comprehensive study of the band alignments of TixAl1−xOy (with x = 9%, 16%, 25%, 36%, 100%) and GaxAl1−xOy (x = 5%, 20%, 80% and 95%) fabricated using atomic layer deposition on GaN has been presented using X-ray photoelectron spectroscopy and variable angle spectroscopic ellipsometry. The permittivity, k, has been found to be enhanced from ~10 for 9% Ti in TixAl1−xOy to 76 for TiO2, however TiO2 brings an unfavorable band alignment and a small conduction band offset (<0.1 eV) with GaN. The latter has been observed for all studied TixAl1−xOy films deposited on GaN. On the other hand, GaxAl1−xOy films show a substantial increase of the band gap from 4.5 eV for Ga2O3 to 5.5 eV for x = 20% Ga and 6.0 eV for x = 5% Ga. A strong suppression of leakage current in associated GaxAl1−xOy-based metal insulator semiconductor capacitors has also been observed, showing promise for device applications

    A CO2?Tolerant Perovskite Oxide with High Oxide Ion and Electronic Conductivity

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    Mixed ionic–electronic conductors (MIECs) that display high oxide ion conductivity (σo) and electronic conductivity (σe) constitute an important family of electrocatalysts for a variety of applications including fuel cells and oxygen separation membranes. Often MIECs exhibit sufficient σe but inadequate σo. It has been a long‐standing challenge to develop MIECs with both high σo and stability under device operation conditions. For example, the well‐known perovskite oxide Ba0.5Sr0.5Co0.8Fe0.2O3−ή (BSCF) exhibits exceptional σo and electrocatalytic activity. The reactivity of BSCF with CO2, however, limits its use in practical applications. Here, the perovskite oxide Bi0.15Sr0.85Co0.8Fe0.2O3−ή (BiSCF) is shown to exhibit not only exceptional bulk transport properties, with a σo among the highest for known MIECs, but also high CO2 tolerance. When used as an oxygen separation membrane, BiSCF displays high oxygen permeability comparable to that of BSCF and much higher stability under CO2. The combination of high oxide transport properties and CO2 tolerance in a single‐phase MIEC gives BiSCF a significant advantage over existing MIECs for practical applications

    Suppression of mRNAs Encoding Tegument Tetraspanins from Schistosoma mansoni Results in Impaired Tegument Turnover

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    Schistosomes express a family of integral membrane proteins, called tetraspanins (TSPs), in the outer surface membranes of the tegument. Two of these tetraspanins, Sm-TSP-1 and Sm-TSP-2, confer protection as vaccines in mice, and individuals who are naturally resistant to S. mansoni infection mount a strong IgG response to Sm-TSP-2. To determine their functions in the tegument of S. mansoni we used RNA interference to silence expression of Sm-tsp-1 and Sm-tsp-2 mRNAs. Soaking of parasites in Sm-tsp dsRNAs resulted in 61% (p = 0.009) and 74% (p = 0.009) reductions in Sm-tsp-1 and Sm-tsp-2 transcription levels, respectively, in adult worms, and 67%–75% (p = 0.011) and 69%–89% (p = 0.004) reductions in Sm-tsp-1 and Sm-tsp-2 transcription levels, respectively, in schistosomula compared to worms treated with irrelevant control (luciferase) dsRNA. Ultrastructural morphology of adult worms treated in vitro with Sm-tsp-2 dsRNA displayed a distinctly vacuolated and thinner tegument compared with controls. Schistosomula exposed in vitro to Sm-tsp-2 dsRNA had a significantly thinner and more vacuolated tegument, and morphology consistent with a failure of tegumentary invaginations to close. Injection of mice with schistosomula that had been electroporated with Sm-tsp-1 and Sm-tsp-2 dsRNAs resulted in 61% (p = 0.005) and 83% (p = 0.002) reductions in the numbers of parasites recovered from the mesenteries four weeks later when compared to dsRNA-treated controls. These results imply that tetraspanins play important structural roles impacting tegument development, maturation or stability

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Crop Updates 2007 - Lupins, Pulses and Oilseeds

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    This session covers forty eight papers from different authors: 2006 REGIONAL ROUNDUP 1. South east agricultural region, Mark Seymour1 and Jacinta Falconer2, 1Department of Agriculture and Food, 2Cooperative Bulk Handling Group 2. Central agricultural region, Ian Pritchard, Department of Agriculture and Food 3. Great Southern and Lakes region, Rodger Beermier, Department of Agriculture and Food 4. Northern agricultural region, Wayne Parker and Martin Harries, Department of Agriculture and Food LUPINS 5. Development of anthracnose resistant and early flowering albus lupins (Lupinus albus L) in Western Australia, Kedar Adhikari and Geoff Thomas, Department of Agriculture and Food 6. New lupins adapted to the south coast, Peter White, Bevan Buirchell and Mike Baker, Department of Agriculture and Food 7. Lupin species and row spacing interactions by environment, Martin Harries, Peter White, Bob French, Jo Walker, Mike Baker and Laurie Maiolo, Department of Agriculture and Food 8. The interaction of lupin species row spacing and soil type, Martin Harries, Bob French, Laurie Maiolo and Jo Walker, Department of Agriculture and Food 9. The effects of row spacing and crop density on competitiveness of lupins with wild radish, Bob French and Laurie Maiolo, Department of Agriculture and Food 10. The effect of time of sowing and radish weed density on lupin yield, Martin Harries and Jo Walker, Department of Agriculture and Food 11. Interaction of time of sowing and weed management in lupins, Martin Harries and Jo Walker, Department of Agriculture and Food 12. Delayed sowing as a strategy to manage annual ryegrass, Bob French and Laurie Maiolo, Department of Agriculture and Food 13. Is delayed sowing a good strategy for weed management in lupins? Bob French, Department of Agriculture and Food 14. Lupins aren’t lupins when it comes to simazine, Peter White and Leigh Smith, Department of Agriculture and Food 15. Seed yield and anthracnose resistance of Tanjil mutants tolerant to metribuzin, Ping Si1, Bevan Buirchell1,2 and Mark Sweetingham1,2, 1Centre for Legumes in Mediterranean Agriculture, Australia; 2Department of Agriculture and Food 16. The effect of herbicides on nodulation in lupins, Lorne Mills1, Harmohinder Dhammu2 and Beng Tan1, 1Curtin University of Technology and 2Department of Agriculture and Food 17. Effect of fertiliser placements and watering regimes on lupin growth and seed yield in the central grain belt of Western Australia, Qifu Ma1, Zed Rengel1, Bill Bowden2, Ross Brennan2, Reg Lunt2 and Tim Hilder2, 1Soil Science & Plant Nutrition UWA, 2Department of Agriculture and Food 18. Development of a forecasting model for Bean Yellow Mosaic Virus in lupins, T. Maling1,2, A. Diggle1, D. Thackray1,2, R.A.C. Jones2, and K.H.M. Siddique1, 1Centre for Legumes in Mediterranean Agriculture, The University of Western Australia; 2Department of Agriculture and Food 19. Manufacturing of lupin tempe,Vijay Jayasena1,4, Leonardus Kardono2,4, Ken Quail3,4 and Ranil Coorey1,4, 1Curtin University of Technology, Perth, Australia, 2Indonesian Institute of Sciences (LIPI), Indonesia, 3BRI Australia Ltd, Sydney, Australia, 4Grain Foods CRC, Sydney, Australia 20. The impact of lupin based ingredients in ice-cream, Hannah Williams, Lee Sheer Yap and Vijay Jayasena, Curtin University of Technology, Perth WA 21. The acceptability of muffins substituted with varying concentrations of lupin flour, Anthony James, Don Elani Jayawardena and Vijay Jayasena, Curtin University of Technology, PerthWA PULSES 22. Chickpea variety evaluation, Kerry Regan1, Rod Hunter1, Tanveer Khan1,2and Jenny Garlinge1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 23. Advanced breeding trials of desi chickpea, Khan, T.N.1, Siddique, K.H.M.3, Clarke, H.2, Turner, N.C.2, MacLeod, W.1, Morgan, S.1, and Harris, A.1, 1Department of Agriculture and Food, 2Centre for Legumes in Mediterranean Agriculture, 3TheUniversity of Western Australia 24. Ascochyta resistance in chickpea lines in Crop Variety Testing (CVT) of 2006, Tanveer Khan1 2, Bill MacLeod1, Alan Harris1, Stuart Morgan1and Kerry Regan1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 25. Yield evaluation of ascochyta blight resistant Kabuli chickpeas, Kerry Regan1and Kadambot Siddique2, 1Department of Agriculture and Food, 2Institute of Agriculture, The University of Western Australia 26. Pulse WA Chickpea Industry Survey 2006, Mark Seymour1, Ian Pritchard1, Wayne Parker1and Alan Meldrum2, 1Department of Agriculture and Food, 2Pulse Australia 27. Genes from the wild as a valuable genetic resource for chickpea improvement, Heather Clarke1, Helen Bowers1and Kadambot Siddique2, 1Centre for Legumes in Mediterranean Agriculture, 2Institute of Agriculture, The University of Western Australia 28. International screening of chickpea for resistance to Botrytis grey mould, B. MacLeod1, Dr T. Khan1, Prof. K.H.M. Siddique2and Dr A. Bakr3, 1Department of Agriculture and Food, 2The University of Western Australia, 3Bangladesh Agricultural Research Institute 29. BalanceÂź in chickpea is safest applied post sowing to a level seed bed, Wayne Parker, Department of Agriculture and Food, 30. Demonstrations of Genesis 510 chickpea, Wayne Parker, Department of Agriculture and Food 31. Field pea 2006, Ian Pritchard, Department of Agriculture and Food 32. Field pea variety evaluation, Kerry Regan1, Rod Hunter1, Tanveer Khan1,2 and Jenny Garlinge1, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia 33. Breeding highlights of the Australian Field Pea Improvement Program (AFPIP),Kerry Regan1, Tanveer Khan1,2, Phillip Chambers1, Chris Veitch1, Stuart Morgan1 , Alan Harris1and Tony Leonforte3, 1Department of Agriculture and Food, 2CLIMA, The University of Western Australia, 3Department of Primary Industries, Victoria 34. Field pea germplasm enhancement for black spot resistance, Tanveer Khan, Kerry Regan, Stuart Morgan, Alan Harris and Phillip Chambers, Department of Agriculture and Food 35. Validation of Blackspot spore release model and testing moderately resistant field pea line, Mark Seymour, Ian Pritchard, Rodger Beermier, Pam Burgess and Leanne Young, Department of Agriculture and Food 36. Yield losses from sowing field pea seed infected with Pea Seed-borne Mosaic Virus, Brenda Coutts, Donna O’Keefe, Rhonda Pearce, Monica Kehoe and Roger Jones, Department of Agriculture and Food 37. Faba bean in 2006, Mark Seymour, Department of Agriculture and Food 38. Germplasm evaluation – faba bean, Mark Seymour1, Terri Jasper1, Ian Pritchard1, Mike Baker1 and Tim Pope1,2, 1Department of Agriculture and Food, , 2CLIMA, The University of Western Australia 39. Breeding highlights of the Coordinated Improvement Program for Australian Lentils (CIPAL), Kerry Regan1, Chris Veitch1, Phillip Chambers1 and Michael Materne2, 1Department of Agriculture and Food, 2Department of Primary Industries, Victoria 40. Screening pulse lentil germplasm for tolerance to alternate herbicides, Ping Si1, Mike Walsh2 and Mark Sweetingham1,3, 1Centre for Legumes in Mediterranean Agriculture, 2West Australian Herbicide Resistance Initiative, 3Department of Agriculture and Food 41. Genomic synteny in legumes: Application to crop breeding, Phan, H.T.T.1, Ellwood, S.R.1, Hane, J.1, Williams, A.1, Ford, R.2, Thomas, S.3 and Oliver R1, 1Australian Centre of Necrotrophic Plant Pathogens, Murdoch University, 2BioMarka, University of Melbourne, 3NSW Department of Primary Industries 42. Tolerance of lupins, chickpeas and canola to BalanceĂą(Isoxaflutole) and GalleryĂą (Isoxaben), Leigh Smith and Peter White, Department of Agriculture and Food CANOLA AND OILSEEDS 43. The performance of TT Canola varieties in the National Variety Test (NVT),WA,2006,Katie Robinson, Research Agronomist, Agritech Crop Research 44. Evaluation of Brassica crops for biodiesel in Western Australia, Mohammad Amjad, Graham Walton, Pat Fels and Andy Sutherland, Department of Agriculture and Food 45. Production risk of canola in different rainfall zones in Western Australia, Imma FarrĂ©1, Michael Robertson2 and Senthold Asseng3, 1Department of Agriculture and Food, 2CSIRO Sustainable Ecosystems, 3CSIRO Plant Industry 46. Future directions of blackleg management – dynamics of blackleg susceptibility in canola varieties, Ravjit Khangura, Moin Salam and Bill MacLeod, Department of Agriculture and Food 47. Appendix 1: Contributors 48. Appendix 2: List of common acronym

    P-type conductivity in Sn-doped Sb2Se3

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    Antimony selenide (Sb2Se3) is a promising absorber material for thin-film photovoltaics. However, certain areas of fundamental understanding of this material remain incomplete and this presents a barrier to further efficiency gains. In particular, recent studies have highlighted the role of majority carrier type and extrinsic doping in drastically changing the performance of high efficiency devices [1]. Herein, Sndoped Sb2Se3 bulk crystals are shown to exhibit p-type conductivity using Hall effect and hot-probe measurements. The measured conductivities are higher than those achieved through native defects alone, but with a carrier density (up to 7.4 × 1014 cm−3) several orders of magnitude smaller than the quantity of Sn included in the source material. Additionally, a combination of ultraviolet, X-ray and hard X-ray photoemission spectroscopies are employed to obtain a non-destructive depth profile of the valence band maximum, confirming p-type conductivity and indicating a majority carrier type inversion layer at the surface. Finally, these results are supported by density functional theory calculations of the defect formation energies in Sn-doped Sb2Se3, showing a possible limit on the carrier concentration achievable with Sn as a dopant. This study sheds light on the effectiveness of Sn as a p-type dopant in Sb2Se3 and highlights avenues for further optimisation of doped Sb2Se3 for solar energy devices
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