ORCID Profile
0000-0001-8751-2620
Current Organisations
Karlsruher Institut für Technologie
,
Instruments & Data Tools
,
Yokohama National University
,
RMIT University
,
Universita degli Studi di Roma La Sapienza
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Publisher: The Optical Society
Date: 12-04-2011
DOI: 10.1364/OE.19.008073
Publisher: The Optical Society
Date: 07-11-2013
DOI: 10.1364/OE.21.028019
Publisher: International Union of Crystallography (IUCr)
Date: 27-07-2011
Publisher: Proceedings of the National Academy of Sciences
Date: 30-05-2023
Abstract: Demand for food products, often from international trade, has brought agricultural land use into direct competition with bio ersity. Where these potential conflicts occur and which consumers are responsible is poorly understood. By combining conservation priority (CP) maps with agricultural trade data, we estimate current potential conservation risk hotspots driven by 197 countries across 48 agricultural products. Globally, a third of agricultural production occurs in sites of high CP (CP 0.75, max = 1.0). While cattle, maize, rice, and soybean pose the greatest threat to very high-CP sites, other low-conservation risk products (e.g., sugar beet, pearl millet, and sunflower) currently are less likely to be grown in sites of agriculture–conservation conflict. Our analysis suggests that a commodity can cause dissimilar conservation threats in different production regions. Accordingly, some of the conservation risks posed by different countries depend on their demand and sourcing patterns of agricultural commodities. Our spatial analyses identify potential hotspots of competition between agriculture and high-conservation value sites (i.e., 0.5° resolution, or ~367 to 3,077km 2 , grid cells containing both agriculture and high-bio ersity priority habitat), thereby providing additional information that could help prioritize conservation activities and safeguard bio ersity in in idual countries and globally. A web-based GIS tool at io ersity/ systematically visualizes the results of our analyses.
Publisher: American Physical Society (APS)
Date: 27-07-2023
Publisher: Wiley
Date: 16-03-2011
DOI: 10.1118/1.3560889
Abstract: In the hard x-ray region, the cross sections for the phase shift of low-Z elements are about 1000 times larger than the absorption ones. As a consequence, phase contrast is detectable even when absorption contrast is minimal or absent. Therefore, phase-contrast imaging could become a valid alternative to absorption contrast without delivering high dose to tissue/human body parts. To enhance the quality of phase-contrast images without increasing the dose, a possible approach could be the partial deconvolution of the finite source size effects by experimental phase-contrast images. The deconvolution procedure, the authors propose, employs the acquisition of two images on a suitable well-known test s le, one in contact and the other in phase-contrast conditions. Both acquired images are used along with a simulated phase-contrast image (obtained from the test s le in ideal conditions of pointlike source illumination) to correctly retrieve the experimental source distribution function. This information allows a generic experimental phase-contrast image, acquired in the same conditions, to be partially deconvolved by finite source size effects. The performed experimental tests indicate that deconvolved images are equivalent to those which would be obtained with a source 40% smaller than the actual size. In turn, this finding is equivalent to an increase of the "effective" lateral spatial coherence length. The corresponding quality improvement of the phase-contrast imaging is directly deducible by the presence of many Fresnel fringes, much better visible with respect to the original experimental phase-contrast images. The use of a test standard s le, always possible in every experimental setup, to partially deconvolve the finite-size-source blurring effects shows that higher quality phase-contrast images could be readily available, making easier diagnoses and tissue/s le analyses. The method could give, in the future, the possibility to further lower the delivered dose to patients, organs, and tissues when compact room-sized and brilliant microfocus x-ray sources will be available for clinical applications in hospitals.
Publisher: Informa UK Limited
Date: 09-2009
Publisher: MDPI AG
Date: 17-11-2020
DOI: 10.3390/S20226555
Abstract: Technology for rapid, non-invasive and accurate determination of fruit maturity is increasingly sought after in horticultural industries. This study investigated the ability to predict fruit maturity of yellow peach cultivars using a prototype non-destructive fluorescence spectrometer. Collected spectra were analysed to predict flesh firmness (FF), soluble solids concentration (SSC), index of absorbance difference (IAD), skin and flesh colour attributes (i.e., a* and H°) and maturity classes (immature, harvest-ready and mature) in four yellow peach cultivars—‘August Flame’, ‘O’Henry’, ‘Redhaven’ and ‘September Sun’. The cultivars provided a erse range of maturity indices. The fluorescence spectrometer consistently predicted IAD and skin colour in all the cultivars under study with high accuracy (Lin’s concordance correlation coefficient 0.85), whereas flesh colour’s estimation was always accurate apart from ‘Redhaven’. Except for ‘September Sun’, good prediction of FF and SSC was observed. Fruit maturity classes were reliably predicted with a high likelihood (F1-score = 0.85) when s les from the four cultivars were pooled together. Further studies are needed to assess the performance of the fluorescence spectrometer on other fruit crops. Work is underway to develop a handheld version of the fluorescence spectrometer to improve the utility and adoption by fruit growers, packhouses and supply chain managers.
Publisher: The Optical Society
Date: 06-07-2011
DOI: 10.1364/OL.36.002602
Publisher: The Optical Society
Date: 16-07-2014
Publisher: American Physical Society (APS)
Date: 18-05-2020
Publisher: Elsevier BV
Date: 10-2009
Publisher: AIP Publishing
Date: 22-01-2007
DOI: 10.1063/1.2431457
Abstract: Coherent x-ray diffraction experiments were performed in Fresnel regime, within a line-projection geometry. A planar x-ray waveguide was used to focus coherent cylindrical waves onto a 7.2μm Kevlar fiber, which acts as a phase object for hard x rays. The phase was retrieved, by using a Fourier-based iterative phasing algorithm, consistent with measured diffraction data and known constraints in real space, with a submicrometer spatial resolution.
Publisher: Optica Publishing Group
Date: 20-04-2006
DOI: 10.1364/AO.45.002821
Abstract: We study the propagation of ultrashort pulses in x-ray waveguides (WGs) by addressing the problem of the temporal dispersion. Starting from basic equations, by means of numerical calculation we demonstrate that far from the absorption edges of the WGs the cladding's material dispersion is negligible. However, close to the absorption edge significant dispersion can take place. This behavior could in principle be exploited to manipulate incoming chirped beams. Moreover, using the two coherent beams produced by the WG in the second (and higher) order of resonance suggests the use of the WC as a dispersion-free beam splitter, which can facilitate x-ray pump-probe experiments in the femtosecond temporal range without the need for external sources.
Publisher: Wiley
Date: 19-08-2013
Publisher: International Union of Crystallography (IUCr)
Date: 14-11-2010
Publisher: American Physical Society (APS)
Date: 27-02-2023
Publisher: OSA
Date: 2014
Publisher: Elsevier BV
Date: 07-2007
Publisher: IOP Publishing
Date: 13-12-2014
DOI: 10.1088/0031-9155/59/1/189
Abstract: Computed x-ray phase contrast micro-tomography is the most valuable tool for a three dimensional (3D) and non destructive analysis of the tissue engineered bone morphology. We used a Talbot interferometer installed at SYRMEP beamline of the ELETTRA synchrotron (Trieste, Italy) for a precise 3D reconstruction of both bone and soft connective tissue, regenerated in vivo within a porous scaffold. For the first time the x-ray tomographic reconstructions have been combined with x-ray scanning micro-diffraction measurement on the same s le, in order to give an exhaustive identification of the different tissues participating to the biomineralization process. As a result, we were able to investigate in detail the different densities in the tissues, distinguishing the 3D organization of the amorphous calcium phosphate from the collagen matrix. Our experimental approach allows for a deeper understanding of the role of collagen matrix in the organic-mineral transition, which is a crucial issue for the development of new bio-inspired composites.
Publisher: Walter de Gruyter GmbH
Date: 10-2009
DOI: 10.3139/120.110081
Abstract: Mikrotomographie erlaubt die hochauflösende Abbildung verdeckter Mikrostrukturen und den Nachweis von Mikrorissen und Mikroporen in vielfältigen Bereichen, darunter die Untersuchung von mikroporösen Materialien und Fasernetzwerken, der Mikrostruktur biokompatibler Materialien (Implantate), der Entwicklung der Struktur von Metallgefügen u.v.m. Synchrotron-Laminographie erweitert das Anwendungsspektrum der 3-D-Methoden auf die zerstörungsfreie Bauteiluntersuchung ohne Probenentnahme bzw. Probenpräparation, und erweitert die hoch auflösende Inspektion z.B. in der Mikrosystemtechnik, der Paläontologie Archäologie etc. Ultraschnelle Radiographie, Computertomographie und Laminographie erlauben die In-situ-Untersuchung von Proben und Bauteilen in Echtzeit und unter betriebsnahen Bedingungen verschiedenster Probenumgebung. Phasenkontrast erweitert die Anwendungsbreite der 2-D und 3-D abbildenden Synchrotronverfahren auf leichte Materialien und führte die Methoden damit in die Leichtbautechnologien und die Lebenswissenschaften. Die Kombination der Techniken mit Röntgenoptiken treibt die Grenzen der Ortsauflösung in den Bereich weniger 10 nm.
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 10-2019
Publisher: American Physical Society (APS)
Date: 20-09-2022
Publisher: Elsevier BV
Date: 03-2010
Publisher: MDPI AG
Date: 19-08-2021
DOI: 10.3390/HORTICULTURAE7080255
Abstract: This work aimed to (i) determine the reliability of a portable Bluetooth colourimeter for fruit colour measurements (ii) characterise the changes in quantitative skin colour attributes in a nectarine cultivar in response to time from harvest and (iii) determine the influence of row orientation and training system on nectarine skin colour. The skin colour attributes measured with the colourimeter, namely L*, a* and b*, were calibrated and validated against a reference spectrophotometer. C* and h° were obtained from a* and b*. Skin colour was measured in situ from 42 days before to 6 days after harvest on ‘Majestic Pearl’ nectarines subjected to different row orientations and training systems. Validation models showed high reliability of colour estimations. The trends of colour attributes over time were characterised by cubic regression models, with h° proving to be the best parameter to describe changes of colour over time, with a clear link to the maturation process. No significant effects of row orientation and training system on skin colour were observed at harvest. Overall, the device proved reliable for fruit colour detection. Results of this study highlight the potential of h° as a quantitative index to monitor ripening prior to harvest in ‘Majestic Pearl’ nectarines.
Publisher: International Union of Crystallography (IUCr)
Date: 07-06-2018
DOI: 10.1107/S205225251800711X
Abstract: An experimental procedure for transmission X-ray ghost imaging using synchrotron light is presented. Hard X-rays from an undulator were ided by a beamsplitter to produce two copies of a speckled incident beam. Both beams were simultaneously measured on an indirect pixellated detector and the intensity correlation between the two copies was used to retrieve the ghost image of s les placed in one of the two beams, without measuring the s les directly. Aiming at future practical uses of X-ray ghost imaging, the authors discuss details regarding data acquisition, image reconstruction strategies and measure the point-spread function of the ghost-imaging system. This approach may become relevant for applications of ghost imaging with X-ray sources such as undulators in storage rings, free-electron lasers and lower-coherence laboratory facilities.
Publisher: American Physical Society (APS)
Date: 10-02-2004
Publisher: The Optical Society
Date: 25-07-2012
DOI: 10.1364/OE.20.018287
Publisher: IOP Publishing
Date: 11-2010
Publisher: Elsevier BV
Date: 12-2014
Publisher: AIP Publishing
Date: 04-2011
DOI: 10.1063/1.3561866
Abstract: Applications of porous silicon are ranging from drug delivery vehicles to micro fuel cells. The size of the pores and their distribution plays critical role in the final properties of the devices manufactured on their base. We performed nondestructive quantitative experimental studies of selected porous silicon s les with gradient porosity. We were able to determine the average size of the pores and its dynamics as a function of the etching time. We also were able to determine the statistical parameters of the pore formation.
Publisher: The Optical Society
Date: 29-11-2018
Publisher: The Optical Society
Date: 14-07-2010
DOI: 10.1364/OE.18.015998
Publisher: American Physical Society (APS)
Date: 09-10-2003
Publisher: The Optical Society
Date: 28-07-2015
DOI: 10.1364/OL.40.003611
Publisher: Frontiers Media SA
Date: 07-09-2015
Publisher: Inderscience Publishers
Date: 2014
Publisher: Inderscience Publishers
Date: 2014
Publisher: The Optical Society
Date: 07-07-2015
DOI: 10.1364/OE.23.018391
Publisher: American Physical Society (APS)
Date: 21-02-2008
Publisher: IOP Publishing
Date: 05-06-2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2018
Publisher: AIP Publishing
Date: 20-07-2015
DOI: 10.1063/1.4927038
Abstract: We report on the experimental realization of propagation-based x-ray microscopy with laboratory sources equipped with waveguides. We discuss about the experimental setup, the fabrication steps, and the characterization procedures of the waveguide optics. We demonstrate that the system enables high resolution attenuation imaging of poorly absorbing biological specimens. Furthermore, we report the successful realization of propagation-based phase contrast x-ray microscopy, enabling quantitative thickness estimation in homogeneous objects. Advantages and major limitations of the experimental scheme are presented and discussed.
Publisher: International Union of Crystallography (IUCr)
Date: 18-05-2017
DOI: 10.1107/S1600577517006233
Abstract: Therapeutic applications of synchrotron X-rays such as microbeam (MRT) and minibeam (MBRT) radiation therapy promise significant advantages over conventional clinical techniques for some diseases if successfully transferred to clinical practice. Preclinical studies show clear evidence that a number of normal tissues in animal models display a tolerance to much higher doses from MRT compared with conventional radiotherapy. However, a wide spread in the parameters studied makes it difficult to make any conclusions about the associated tumour control or normal tissue complication probabilities. To facilitate more systematic and reproducible preclinical synchrotron radiotherapy studies, a dedicated preclinical station including small-animal irradiation stage was designed and installed at the Imaging and Medical Beamline (IMBL) at the Australian Synchrotron. The stage was characterized in terms of the accuracy and reliability of the vertical scanning speed, as this is the key variable in dose delivery. The measured speed was found to be within 1% of the nominal speed for the range of speeds measured by an interferometer. Furthermore, dose measurements confirm the expected relationship between speed and dose and show that the measured dose is independent of the scan direction. Important dosimetric parameters such as peak dose, valley dose, the collimator output factor and peak-to-valley dose ratio are presented for 5 mm × 5 mm, 10 mm × 10 mm and 20 mm × 20 mm field sizes. Finally, a feasibility study on three glioma-bearing rats was performed. MRT and MBRT doses were prescribed to achieve an average dose of 65 Gy in the target, and magnetic resonance imaging follow-up was performed at various time points after irradiation to follow the tumour volume. Although it is impossible to draw conclusions on the different treatments with such a small number of animals, the feasibility of end-to-end preclinical synchrotron radiotherapy studies using the IMBL preclinical stage is demonstrated.
Publisher: Elsevier BV
Date: 05-2011
Publisher: Springer Science and Business Media LLC
Date: 09-1996
DOI: 10.1007/BF01833797
Publisher: Elsevier BV
Date: 08-2013
Publisher: Elsevier BV
Date: 06-2008
Publisher: Elsevier BV
Date: 02-1998
Publisher: The Optical Society
Date: 08-08-2013
DOI: 10.1364/OE.21.019401
Publisher: International Union of Crystallography (IUCr)
Date: 28-01-2016
DOI: 10.1107/S1600577515022894
Abstract: The protocol for image-guided microbeam radiotherapy (MRT) developed for the Australian Synchrotron's Imaging and Medical Beamline (IMBL) is described. The protocol has been designed for the small-animal MRT station of IMBL to enable future preclinical trials on rodents. The image guidance procedure allows for low-dose monochromatic imaging at 50 keV and subsequent semi-automated s le alignment in 3D with sub-100 µm accuracy. Following the alignment, a beamline operation mode change is performed and the relevant beamline components are automatically aligned for the treatment (pink) beam to be delivered on the s le. Here, the small-animal MRT station, the parameters and procedures for the image guidance protocol, as well as the experimental imaging results using phantoms are described. Furthermore, the experimental validation of the protocol using 3D PRESAGE ® dosimeters is reported. It is demonstrated that the s le alignment is maintained after the mode change and the treatment can be delivered within the same spatial accuracy of 100 µm. The results indicate that the proposed approach is viable for preclinical trials of small-animal MRT.
Publisher: The Optical Society
Date: 12-03-2014
DOI: 10.1364/BOE.5.001153
Publisher: Optica Publishing Group
Date: 03-08-2023
Abstract: The penetrating power of x rays underpins important applications such as medical radiography. However, this same attribute makes it challenging to achieve flexible on-demand patterning of x-ray beams. One possible path to this goal is “ghost projection,” a method that may be viewed as a reversed form of classical ghost imaging. This technique employs multiple exposures of a single illuminated non-configurable mask that is transversely displaced to a number of specified positions to create any desired pattern. An experimental proof of concept is given for this idea, using hard x rays. The written pattern is arbitrary, up to a tunable constant offset, and its spatial resolution is limited by both (i) the finest features present in the illuminated mask and (ii) inaccuracies in mask positioning and mask exposure time. In principle, the method could be used to make a universal lithographic mask in the hard-x-ray regime. Ghost projection might also be used as a dynamically configurable beam-shaping element, namely, the hard-x-ray equivalent of a spatial light modulator. The underpinning principle can also be applied to gamma rays, neutrons, electrons, muons, and atomic beams. Our flexible approach to beam shaping gives a potentially useful means to manipulate such fields.
Publisher: Elsevier BV
Date: 04-2011
Publisher: American Physical Society (APS)
Date: 30-10-2006
Publisher: The Optical Society
Date: 08-04-2013
DOI: 10.1364/OE.21.009308
Publisher: Elsevier BV
Date: 06-2014
Publisher: SPIE
Date: 08-08-2005
DOI: 10.1117/12.640102
Publisher: IOP Publishing
Date: 24-03-2015
DOI: 10.1088/0031-9155/60/8/3065
Abstract: X-ray imaging of soft tissue is made difficult by their low absorbance. The use of x-ray phase imaging and tomography can significantly enhance the detection of these tissues and several approaches have been proposed to this end. Methods such as analyzer-based imaging or grating interferometry produce differential phase projections that can be used to reconstruct the 3D distribution of the s le refractive index. We report on the quantitative comparison of three different methods to obtain x-ray phase tomography with filtered back-projection from differential phase projections in the presence of noise. The three procedures represent different numerical approaches to solve the same mathematical problem, namely phase retrieval and filtered back-projection. It is found that obtaining in idual phase projections and subsequently applying a conventional filtered back-projection algorithm produces the best results for noisy experimental data, when compared with other procedures based on the Hilbert transform. The algorithms are tested on simulated phantom data with added noise and the predictions are confirmed by experimental data acquired using a grating interferometer. The experiment is performed on unstained adult zebrafish, an important model organism for biomedical studies. The method optimization described here allows resolution of weak soft tissue features, such as muscle fibers.
Publisher: IOP Publishing
Date: 20-04-2018
Publisher: Elsevier BV
Date: 11-2014
Publisher: Springer Science and Business Media LLC
Date: 29-01-2016
Publisher: The Optical Society
Date: 21-05-2013
DOI: 10.1364/OL.38.001808
Publisher: The Optical Society
Date: 13-01-2012
DOI: 10.1364/OL.37.000262
Publisher: American Physical Society (APS)
Date: 05-07-2012
Publisher: Elsevier BV
Date: 09-2013
Publisher: IOP Publishing
Date: 06-05-2005
Publisher: The Optical Society
Date: 17-06-2014
DOI: 10.1364/OE.22.015437
Publisher: International Union of Crystallography (IUCr)
Date: 07-06-2022
DOI: 10.1107/S1600577522004829
Abstract: In this work, a new image guidance system and protocols for delivering image-guided radiotherapy (IGRT) on the Imaging and Medical Beamline (IMBL) at the ANSTO Australian Synchrotron are introduced. The image guidance methods used and the resulting accuracy of tumour alignment in in vivo experiments are often under-reported. Image guidance tasks are often complex, time-consuming and prone to errors. If unchecked, they may result in potential mis-treatments. We introduce SyncMRT , a software package that provides a simple, image guidance tool-kit for aligning s les to the synchrotron beam. We have demonstrated sub-millimetre alignment using SyncMRT and the small-animal irradiation platform (the DynamicMRT system) on the IMBL. SyncMRT has become the standard for carrying out IGRT treatments on the IMBL and has been used in all pre-clinical radiotherapy experiments since 2017. Further, we introduce two quality assurance (QA) protocols to synchrotron radiotherapy on the IMBL: the Winston-Lutz test and hidden target test. It is shown that the presented QA tests are appropriate for picking up geometrical setup errors and assessing the end-to-end accuracy of the image guidance process. Together, these tools make image guidance easier and provide a mechanism for reporting the geometric accuracy of synchrotron-based IGRT treatments. Importantly, this work is scalable to other delivery systems, and is in continual development to support the upcoming veterinary radiotherapy trials on the IMBL.
Publisher: American Physical Society (APS)
Date: 07-09-2016
Publisher: The Optical Society
Date: 28-08-2014
DOI: 10.1364/OE.22.021508
Publisher: AIP Publishing
Date: 31-07-2006
DOI: 10.1063/1.2236283
Abstract: An innovative route for deep-submicrometer spatial resolution hard x-ray microscopy with tabletop x-ray source is proposed. A film of lithium fluoride (LiF) was used as imaging detector in contact mode. We present here the x-ray images recorded on LiF films of a Fresnel zone plate with submicrometer gold structures and of an onion cataphyll. The images were read with an optical confocal microscope in fluorescence mode. The measured spatial resolution was about 250nm, i.e., close to the resolution limit of the confocal microscope. The advantages and drawbacks, and the possible improvements, of this route are discussed.
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 08-2011
Start Date: 2017
End Date: 2018
Funder: Department of Industry and Science, Australian Government
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