1,943 research outputs found
Adaptive Image Restoration: Perception Based Neural Nework Models and Algorithms.
Abstract This thesis describes research into the field of image restoration. Restoration is a process by which an image suffering some form of distortion or degradation can be recovered to its original form. Two primary concepts within this field have been investigated. The first concept is the use of a Hopfield neural network to implement the constrained least square error method of image restoration. In this thesis, the author reviews previous neural network restoration algorithms in the literature and builds on these algorithms to develop a new faster version of the Hopfield neural network algorithm for image restoration. The versatility of the neural network approach is then extended by the author to deal with the cases of spatially variant distortion and adaptive regularisation. It is found that using the Hopfield-based neural network approach, an image suffering spatially variant degradation can be accurately restored without a substantial penalty in restoration time. In addition, the adaptive regularisation restoration technique presented in this thesis is shown to produce superior results when compared to non-adaptive techniques and is particularly effective when applied to the difficult, yet important, problem of semi-blind deconvolution. The second concept investigated in this thesis, is the difficult problem of incorporating concepts involved in human visual perception into image restoration techniques. In this thesis, the author develops a novel image error measure which compares two images based on the differences between local regional statistics rather than pixel level differences. This measure more closely corresponds to the way humans perceive the differences between two images. Two restoration algorithms are developed by the author based on versions of the novel image error measure. It is shown that the algorithms which utilise this error measure have improved performance and produce visually more pleasing images in the cases of colour and grayscale images under high noise conditions. Most importantly, the perception based algorithms are shown to be extremely tolerant of faults in the restoration algorithm and hence are very robust. A number of experiments have been performed to demonstrate the performance of the various algorithms presented
Ethics and the Public Administrator
This article provides an overview and analysis of the practical problems of developing and implementing a code of ethics for public administrators. The article addresses three key issues: (1) What are public ethics and where do they come from? (2) What are the central ethical issues facing public administrators? and (3) Are there practical tools and guidelines to assist public servants to be both ethical and effective public managers? The article concludes with a plea for consideration of ethical issues, and it presents five general ethical principles for public administrators
First radial velocity results from the MINiature Exoplanet Radial Velocity Array (MINERVA)
The MINiature Exoplanet Radial Velocity Array (MINERVA) is a dedicated
observatory of four 0.7m robotic telescopes fiber-fed to a KiwiSpec
spectrograph. The MINERVA mission is to discover super-Earths in the habitable
zones of nearby stars. This can be accomplished with MINERVA's unique
combination of high precision and high cadence over long time periods. In this
work, we detail changes to the MINERVA facility that have occurred since our
previous paper. We then describe MINERVA's robotic control software, the
process by which we perform 1D spectral extraction, and our forward modeling
Doppler pipeline. In the process of improving our forward modeling procedure,
we found that our spectrograph's intrinsic instrumental profile is stable for
at least nine months. Because of that, we characterized our instrumental
profile with a time-independent, cubic spline function based on the profile in
the cross dispersion direction, with which we achieved a radial velocity
precision similar to using a conventional "sum-of-Gaussians" instrumental
profile: 1.8 m s over 1.5 months on the RV standard star HD 122064.
Therefore, we conclude that the instrumental profile need not be perfectly
accurate as long as it is stable. In addition, we observed 51 Peg and our
results are consistent with the literature, confirming our spectrograph and
Doppler pipeline are producing accurate and precise radial velocities.Comment: 22 pages, 9 figures, submitted to PASP, Peer-Reviewed and Accepte
In search of the authentic nation: landscape and national identity in Canada and Switzerland
While the study of nationalism and national identity has flourished in the last decade, little attention has been devoted to the conditions under which natural environments acquire significance in definitions of nationhood. This article examines the identity-forming role of landscape depictions in two polyethnic nation-states: Canada and Switzerland. Two types of geographical national identity are identified. The first – what we call the ‘nationalisation of nature’– portrays zarticular landscapes as expressions of national authenticity. The second pattern – what we refer to as the ‘naturalisation of the nation’– rests upon a notion of geographical determinism that depicts specific landscapes as forces capable of determining national identity. The authors offer two reasons why the second pattern came to prevail in the cases under consideration: (1) the affinity between wild landscape and the Romantic ideal of pure, rugged nature, and (2) a divergence between the nationalist ideal of ethnic homogeneity and the polyethnic composition of the two societies under consideration
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(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 deg 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 5
point-source depth in a single visit in will be (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 deg with
, and will be imaged multiple times in six bands, ,
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 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . 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
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Cultivation and sequencing of rumen microbiome members from the Hungate1000 Collection
Productivity of ruminant livestock depends on the rumen microbiota, which ferment indigestible plant polysaccharides into nutrients used for growth. Understanding the functions carried out by the rumen microbiota is important for reducing greenhouse gas production by ruminants and for developing biofuels from lignocellulose. We present 410 cultured bacteria and archaea, together with their reference genomes, representing every cultivated rumen-associated archaeal and bacterial family. We evaluate polysaccharide degradation, short-chain fatty acid production and methanogenesis pathways, and assign specific taxa to functions. A total of 336 organisms were present in available rumen metagenomic data sets, and 134 were present in human gut microbiome data sets. Comparison with the human microbiome revealed rumen-specific enrichment for genes encoding de novo synthesis of vitamin B12, ongoing evolution by gene loss and potential vertical inheritance of the rumen microbiome based on underrepresentation of markers of environmental stress. We estimate that our Hungate genome resource represents ?75% of the genus-level bacterial and archaeal taxa present in the rumen.publishersversionPeer reviewe
Response to Comment on “Plant diversity increases with the strength of negative density dependence at the global scale”
Hülsmann and Hartig suggest that ecological mechanisms other than specialized natural enemies or intraspecific competition contribute to our estimates of conspecific negative density dependence (CNDD). To address their concern, we show that our results are not the result of a methodological artifact and present a null-model analysis that demonstrates that our original findings—(i) stronger CNDD at tropical relative to temperate latitudes and (ii) a latitudinal shift in the relationship between CNDD and species abundance—persist even after controlling for other processes that might influence spatial relationships between adults and recruits
Crop Updates 2002 - Farming Systems
This session covers forty one papers from different authors:
INTRODUCTION
1. Future Farming Systems session for Crop Updates 2002 Peter Metcalf, FARMING SYSTEMS SUBPROGRAM MANAGER GRAINS PROGRAM Department of Agriculture
2. Perennial pastures in annual cropping systems: Lucerne and beyond, the ‘Big Picture’, Mike Ewing, Deputy CEO CRC for Plant-based Management of Dryland Salinity, Department of Agriculture
3. Perennial pastures in annual cropping systems: lucerne and beyond, Roy Latta and Keith Devenish, Department of Agriculture
4. Establishing Lucerne with a cover crop, Diana Fedorenko1, Clayton Butterly1, Chantelle Butterly1, Kim and Neil Diamond2, Stuart McAlpine2, Bill Bowden1, Jessica Johns3, 1Centre for Cropping Systems, Northam, 2Farmer, Buntine, 3Department of Agriculture
5. Overcropping: Chemical suppression of Lucerne, Terry Piper1, Diana Fedorenko1, Clayton Butterly1, Chantelle Butterly1, Stuart McAlpine2, Jessica Johns3, 1Centre for Cropping Systems, Northam, 2Farmer, Buntine, 3Department of Agriculture
6. Overcropping: Effect of Lucerne density on crop yield, Diana Fedorenko1, Bill Bowden1, Clayton Butterly1, Chantelle Butterly1, Stuart McAlpine2, Terry Piper1,1Centre for Cropping Systems, Department of Agriculture, Northam, 2Farmer, Buntine
7. Residual effect of weed management in the third year of Lucerne on the following wheat crop, Diana Fedorenko1, Clayton Butterly1, Chantelle Butterly1, Stuart McAlpine2,Terry Piper1, David Bowran1, Jessica Johns3,1Centre for Cropping Systems, Northam, 2Farmer, Buntine, 3Department of Agriculture
8. Production of Lucerne and serradella in four soil types, Diana Fedorenko1 Clayton Butterly1, Chantelle Butterly1, Robert Beard2 1Centre for Cropping Systems, Department of Agriculture, 2Farmer, Cunderdin
9. The effect of spray topping on newly established Lucerne, Keith Devenish, Agriculture Western Australia
10. Leakage from phase rotations involving Lucerne, Phil Ward, CSIRO Plant Industry
11. Fungal diseases present in Western Australian Lucerne crops, Dominie Wright and Nichole Burges, Department of Agriculture
12. Survey of Western Australian Lucerne stands reveals widespread virus infection, Roger Jones and Danae Harman, Crop Improvement Institute, Department of Agriculture, and Centre for Legumes in Mediterranean Agriculture, University of WA
ANNUAL PASTURE SYSTEMS
13. The use of Twist Fungus as a biosecurity measure against Annual Ryegrass Toxicity (ARGT), Greg Shea, GrainGuard Coordinator and George Yan, Biological and Resource Technology
14.Limitations and opportunities for increasing water use by annual crops and pastures, David Tennant1, Phil Ward2and David Hall1 1Department of Agriculture, 2CSIRO, Plant Industries, Floreat Park
15. Developing pasture species mixtures for more productive and sustainable cropping systems – 2001 crop performance, Anyou Liu, Clinton Revell and Candy Hudson, Centre for Cropping Systems, Department of Agriculture
16. Developing pasture species mixtures for more productive and sustainable cropping systems – weed management in regenerating mixtures, Anyou Liu and Clinton Revell, Centre for Cropping Systems, Department of Agriculture
17. Aphid tolerance of annual pasture legumes, Andrew Blake, Natalie Lauritsen, Department of Agriculture
18. Selecting the right variety for phase pasture systems, Keith Devenish, Department of Agriculture
19. Responses of alternative annual pasture and forage legumes to challenge with infectious subterranean clover mottle virus, John Fosu-Nyarko, Roger Jones, Lisa Smith, Mike Jones and Geoff Dwyer, State Agricultural Biotechnology Centre and Centre for Bioinformatics and Biological Computing, Murdoch University, Department of Agriculture, and Centre for Legumes in Mediterranean Agriculture
SOIL AND LAND MANAGEMENT
20. Nutrition in 2002: Decisions to be made as a result of last season, Bill Bowden,Western Australia Department of Agriculture
21. Profitability of deep banding lime, Michael O\u27Connell, Chris Gazey and David Gartner, Department of Agriculture
22. Lime efficiency percentage…the new measure of lime effectiveness for Western Australia, Amanda Miller, Department of Agriculture
23. Boron – should we be worried about it, Richard W. BellA, K. FrostA, Mike WongBand Ross BrennanC ASchool of Environmental Science, Murdoch University,
BCSIRO Land and Water, CDepartment of Agriculture
24. Impact of claying and other amelioration on paddock profit, N.J. Blake1, G. McConnell2, D. Patabendige1and N. Venn11Department of Agriculture, 2PlanFarm P/L
25. Raised bed farming in the 2001 growing season, Derk Bakker, Greg Hamilton, Dave Houlbrooke and Cliff Spann, Department of Agriculture
26. Economics of tramline farming systems, Paul Blackwell and Bindi Webb, Department of Agriculture, Stuart McAlpine, Liebe Group.
27. Relay planting from Tramlines to increase water use and productivity os summer crops, Dr Paul Blackwell, Department of Agriculture, Neil and Kim Diamond, Buntine. Liebe Group
28.Evidence-based zone management of paddock variability to improve profits and environmental outcomes, M.T.F. WongA, D. PatabendigeB, G. LyleA and K. WittwerA ACSIRO Land and Water, BDepartment of Agriculture
29. How much soil water is lost over summer in sandy soils? Perry Dolling1, Senthold Asseng2, Ian Fillery2, Phil Ward2and Michael Robertson3 1University of Western Australia/Department of Agriculture Western Australia/CSIRO, 2CSIRO Plant Industry 3CSIRO Sustainable Ecosystems, Indooroopilly, Queensland
FARMER DECISION SUPPORT AND ADOPTION
30. Economic comparisons of farming systems for the medium rainfall northern sandplain, No 1, Caroline Peek and David Rogers, Department of Agriculture
31. Sensitivity analysis of farming systems for the medium rainfall northern sandplain No 2, Caroline Peek and David Rogers, Department of Agriculture
32. Transition analysis of farming systems in the medium rainfall northern sandplain. No 3, Caroline Peek and David Rogers, Department of Agriculture
33. Implementing on-farm quality assurance, Peter Portmann, Manager Research and Development, The Grain Pool of Western Australia
34. On-farm research – principles of the ‘Test As You Grow’ kit, Jeff Russell, Department of Agriculture
35. Broadscale wheat variety comparisons featuring Wyalkatchem, Jeff Russell, Department of Agriculture
36. GrainGuardÔ - A biosecurity plan for the Canola Industry,Greg Shea Department of Agriculture
37. Are Western Australian broadacre farms efficient? Ben Henderson, University of Western Australia, Ross Kingwell, Department of Agriculture and University of Western Australia
DISEASE MODELLING WORKSHOP
38. WORKSHOP: Pest and disease forecasts for you! An interactive forum, Tresslyn Walmsley, Jean Galloway, Debbie Thackray, Moin Salam and Art Diggle, Centre for Legumes in Mediterranean Agriculture and Department of Agriculture
39. Blackspot spread: Disease models are based in reality (Workshop paper 1), JeanGalloway,Department of Agriculture
40. Blackspot spread: Scaling-up field data to simulate ‘Baker’s farm’ (Workshop paper 2), Moin U. Salam, Jean Galloway, Art J. Diggle and William J. MacLeod, Department of Agriculture, Western Australia
41. A decision support system for control of aphids and CMV in lupin crops (Workshop paper 3), Debbie Thackray, Jenny Hawkes and Roger Jones, Centre for Legumes in Mediterranean Agriculture and Department of Agricultur
Two-Photon Microscopy for Non-Invasive, Quantitative Monitoring of Stem Cell Differentiation
BACKGROUND: The engineering of functional tissues is a complex multi-stage process, the success of which depends on the careful control of culture conditions and ultimately tissue maturation. To enable the efficient optimization of tissue development protocols, techniques suitable for monitoring the effects of added stimuli and induced tissue changes are needed. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present the quantitative use of two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) as a noninvasive means to monitor the differentiation of human mesenchymal stem cells (hMSCs) using entirely endogenous sources of contrast. We demonstrate that the individual fluorescence contribution from the intrinsic cellular fluorophores NAD(P)H, flavoproteins and lipofuscin can be extracted from TPEF images and monitored dynamically from the same cell population over time. Using the redox ratio, calculated from the contributions of NAD(P)H and flavoproteins, we identify distinct patterns in the evolution of the metabolic activity of hMSCs maintained in either propagation, osteogenic or adipogenic differentiation media. The differentiation of these cells is mirrored by changes in cell morphology apparent in high resolution TPEF images and by the detection of collagen production via SHG imaging. Finally, we find dramatic increases in lipofuscin levels in hMSCs maintained at 20% oxygen vs. those in 5% oxygen, establishing the use of this chromophore as a potential biomarker for oxidative stress. CONCLUSIONS/SIGNIFICANCE: In this study we demonstrate that it is possible to monitor the metabolic activity, morphology, ECM production and oxidative stress of hMSCs in a non-invasive manner. This is accomplished using generally available multiphoton microscopy equipment and simple data analysis techniques, such that the method can widely adopted by laboratories with a diversity of comparable equipment. This method therefore represents a powerful tool, which enables researchers to monitor engineered tissues and optimize culture conditions in a near real time manner
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