595 research outputs found

    Stripping away sky reflectance, waves and turbulence for benthic mapping: Imaging the seafloor not the surface

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    This paper presents the results of an airborne experiment using horizontal and vertical polarising filters on a pair of co-mounted 12.8 megapixel Canon 5D digital cameras. These cameras were mounted in the underside camera port of a light aircraft, both cameras inclined at 30 degrees off-nadir. One camera had the polarisation filter oriented vertically and the other oriented horizontally. Forward-looking, overlapping, oblique aerial photography was captured over known seagrass meadows off the Adelaide metropolitan coastline, plus inland urban water bodies. The portrait oriented field of view allowed a progression on the image from near-nadir to beyond the critical Brewster angle of 53 degrees. Results show the removal of sky reflectance, turbulence and wave action on the vertically-oriented filter imagery compared to the horizontally-oriented filter imagery in both clear and turbid waters. For clear waters the removal of sky reflectance, waves and surface turbulence allowed visualisation of the seafloor suitable for benthic mapping in areas of seagrass. However in turbid water the removal of surface effects still did not allow the seafloor to be visualised due to multiple scatter in the body of the water. This method therefore also has application in differentiating clear and turbid waters on oblique photography

    The behavioral responses of a nocturnal burrowing marsupial (Lasiorhinus latifrons) to drone flight

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    The use of drones in wildlife research and management is increasing. Recent evidence has demonstrated the impact of drones on animal behavior, but the response of nocturnal animals to drone flight remains unknown. Utilizing a lightweight commercial drone, the behavioral response of southern hairy-nosed wombats (Lasiorhinus latifrons) to drone flights was observed at Kooloola Station, Swan Reach, South Australia. All wombats flown over during both day and night flights responded behaviorally to the presence of drones. The response differed based on time of day. The most common night-time behavior elicited by drone flight was retreat, compared to stationary alertness behavior observed for daytime drone flights. The behavioral response of the wombats increased as flight altitude decreased. The marked difference of behavior between day and night indicates that this has implications for studies using drones. The behavior observed during flights was altered due to the presence of the drone, and therefore, shrewd study design is important (i.e., acclimation period to drone flight). Considering the sensory adaptations of the target species and how this may impact its behavioral response when flying at night is essential.Taylor Headland, Bertram Ostendorf, David Taggar

    Seeing seagrasses sidewards: marine angiosperms and the Stokes' polarization parameters

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    Mapping of marine benthic flora using remote sensing techniques has been used to assess the dynamics of environmental conditions in coastal areas. Mostly studies used panchromatic/colour aerial photography and/or medium resolution multispectral satellite imagery to create time series showing the change of seagrass distribution, as indicator species of environmental conditions. While successful within their project parameters, these studies were limited by conditions at time of image capture, such as sun-glare, turbidity, wave action and low contrast in deeper waters due to absorption and scattering. The use of polarized multispectral imagery has the potential to overcome, or at least reduce these problems such that a finer detail of benthic flora may become visible. This paper explores the theoretical background in the application of polarization for mapping seagrass and other marine benthic flora. It also discusses a possible operational design using a low cost airborne multispectral camera.David Hart, Megan Lewis, Bertram Ostendorf and Paul Darehttp://www.arspc.org/abstract/36.ht

    Patients with IgA nephropathy exhibit high systemic PDGF-DD levels

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    Background. Platelet-derived growth factor (PDGF) is a central mediator of mesangioproliferative glomerulonephritis (GN). In experimental mesangioproliferative GN, PDGF-DD serum levels, unlike PDGF-BB, increased up to 1000-fold. Methods. We assessed disease activity in 72 patients with GN, established a novel PDGF-D ELISA and then determined their PDGF-DD levels. In parallel, we studied renal PDGF-DD mRNA expression by RT-PCR. Results. PDGF-DD serum levels in patients with IgA nephropathy (IgAN) were significantly higher (1.67 ± 0.45 ng/ml) and in patients with lupus nephritis significantly lower (0.66 ± 0.86 ng/ml) compared to healthy controls (1.17 ± 0.46 ng/ml), while patients with focal segmental glomerulosclerosis, membranous GN and ANCA-positive vasculitis did not differ from controls. The subgroup of IgAN patients with elevated PDGF-DD levels (27% of samples) did not differ in their clinical features from those with normal PDGF-DD levels. In IgAN patients with repetitive PDGF-DD determinations, most exhibited only minor fluctuations of serum levels over time. Intrarenal PDGF-DD mRNA expression did not differ between controls and patients, suggesting an extrarenal source of the elevated PDGF-DD in IgAN. Conclusions. Serum PDGF-DD levels were specifically elevated in patients with IgAN, in particular in those with early disease, i.e. preserved renal function. Our data support the rationale for anti-PDGF-DD therapy in mesangioproliferative G

    Lehmann-Symanzik-Zimmermann S-Matrix elements on the Moyal Plane

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    Field theories on the Groenewold-Moyal(GM) plane are studied using the Lehmann-Symanzik-Zimmermann(LSZ) formalism. The example of real scalar fields is treated in detail. The S-matrix elements in this non-perturbative approach are shown to be equal to the interaction representation S-matrix elements. This is a new non-trivial result: in both cases, the S-operator is independent of the noncommutative deformation parameter θμν\theta_{\mu\nu} and the change in scattering amplitudes due to noncommutativity is just a time delay. This result is verified in two different ways. But the off-shell Green's functions do depend on θμν\theta_{\mu\nu}. In the course of this analysis, unitarity of the non-perturbative S-matrix is proved as well.Comment: 18 pages, minor corrections, To appear in Phys. Rev. D, 201

    Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications

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    The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes

    Thermal bremsstrahlung probing the thermodynamical state of multifragmenting systems

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    Inclusive and exclusive hard-photon (Eγ>_\gamma > 30 MeV) production in five different heavy-ion reactions (36^{36}Ar+197^{197}Au, 107^{107}Ag, 58^{58}Ni, 12^{12}C at 60{\it A} MeV and 129^{129}Xe+120^{120}Sn at 50{\it A} MeV) has been studied coupling the TAPS photon spectrometer with several charged-particle multidetectors covering more than 80% of 4π\pi. The measured spectra, slope parameters and source velocities as well as their target-dependence, confirm the existence of thermal bremsstrahlung emission from secondary nucleon-nucleon collisions that accounts for roughly 20% of the total hard-photon yield. The thermal slopes are a direct measure of the temperature of the excited nuclear systems produced during the reaction.Comment: 4 pages, 3 figures, Proceedings CRIS 2000, 3rd Catania Relativistic Ion Studies, "Phase Transitions in Strong Interactions: Status and Perspectives", Acicastello, Italy, May 22-26, 2000 (to be published in Nuc. Phys. A

    Emission patterns of neutral pions in 40 A MeV Ta+Au reactions

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    Differential cross sections of neutral pions emitted in 181Ta + 197Au collisions at a beam energy of 39.5A MeV have been measured with the photon spectrometer TAPS. The kinetic energy and transverse momentum spectra of neutral pions cannot be properly described in the framework of the thermal model, nor when the reabsorption of pions is accounted for in a phenomenological model. However, high energy and high momentum tails of the pion spectra can be well fitted through thermal distributions with unexpectedly soft temperature parameters below 10 MeV.Comment: 16 pages (double-spaced), 5 figures; corrections after referee's comments and suggestion

    Робочий зошит до конспекту лекцій з дисциплін “Основи побудови мікропроцесорних систем керування”, “Мікропроцесорна техніка”, “Програмні засоби систем керування” для студентів спеціальностей АГ – 8.092501 Автоматизоване управління технологічними процесами; АТ,ME – 8.091401 Системи управління й автоматики; СМ – 8.091501 Комп`ютерні системи та мережі

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    Дані методичні вказівки призначуються для вивчення апаратних та програмних засобів мікропроцесорних систем управління (МПС). У процесі вивчення дисципліни "Мікропроцесорні системи" студенти вивчають структуру, архітектуру, сигнали та системи команд однокристального мікроконтролера К1816 ВЕ51. Розглянуті питання організації паралельного та послідовного вводу- виводу, оганізація мікропроцесорних контролерів МПК). Схемні рішення, які приведені у методичних вказівках можуть бути використані при виконанні курсових і дипломних проектів студентами спеціальностей "Комп’ютеризовані системи управління і автоматики" (АТ) і "Автоматизація технологічних процесів гірничих підприємств" (АГ) та "Комп’ютерні системи та мережі" (СМ)
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