242 research outputs found
Epigenomic technologies: an interview with Jorg Tost
No full textInternational audienceJörg Tost received his PhD in genetics from the University of Saarbrücken (Germany) in 2004 for devising novel methods for the analysis of haplotypes and DNA methylation patterns. After a postdoctoral stay in the technology development department of the Centre National de Génotypage (Evry, France), he led the Epigenetics groups from 2006 to 2012, before becoming the Director of Laboratory for Epigenetics and Environment at the Centre National de Recherche en Génomique Humaine (CNRGH). The laboratory is involved in the development and application of technologies to analyze DNA methylation, miRNAs and other epigenetic modifications quantitatively at high resolution at target loci and genome-wide using state-of-the-art sequencing technologies as well as the development of bioinformatic tools for the processing of such data. The laboratory mainly focuses on the analysis of epigenetic changes in neurodegenerative, autoimmune and inflammatory diseases as well as the alteration of the epigenetic profiles in function of environmental exposure. A second research axis investigates novel technologies for the analysis of mutations of clinical relevance present at very low proportions in the analyzed samples and their impact on treatment management. Tost has an H-index of 50 and is the author or co-author of more than 195 publications
Ultrafine particles and size distributions from airborne experiments
No full textDataset of ultrafine particles measured during aircraft campaigns with microloght D-MIFU and Dimona VH-OBS and VH-EOS for particle budget studies
Aboriginal artefacts on the continental shelf reveal ancient drowned cultural landscapes in northwest Australia
No full textThis article reports Australia’s first confirmed ancient underwater archaeological sites from the continental shelf, located off the Murujuga coastline in north-western Australia. Details on two underwater sites are reported: Cape Bruguieres, comprising > 260 recorded lithic artefacts at depths down to −2.4 m below sea level, and Flying Foam Passage where the find spot is associated with a submerged freshwater spring at −14 m. The sites were discovered through a purposeful research strategy designed to identify underwater targets, using an iterative process incorporating a variety of aerial and underwater remote sensing techniques and diver investigation within a predictive framework to map the submerged landscape within a depth range of 0–20 m. The condition and context of the lithic artefacts are analysed in order to unravel their depositional and taphonomic history and to corroborate their in situ position on a pre-inundation land surface, taking account of known geomorphological and climatic processes including cyclone activity that could have caused displacement and transportation from adjacent coasts. Geomorphological data and radiometric dates establish the chronological limits of the sites and demonstrate that they cannot be later than 7000 cal BP and 8500 cal BP respectively, based on the dates when they were finally submerged by sea-level rise. Comparison of underwater and onshore lithic assemblages shows differences that are consistent with this chronological interpretation. This article sets a foundation for the research strategies and technologies needed to identify archaeological targets at greater depth on the Australian continental shelf and elsewhere, building on the results presented. Emphasis is also placed on the need for legislation to better protect and manage underwater cultural heritage on the 2 million square kilometres of drowned landscapes that were once available for occupation in Australia, and where a major part of its human history must lie waiting to be discovered
PLIS: an airborne polarimetric L-band interferometric synthetic aperture radar
No full textPLIS is an airborne synthetic aperture radar designed to be used in conjunction with a passive radiometer to collect microwave data at L-band for the remote sensing of soil moisture. The objective is to collect data to carry out a pre-deployment validation of algorithms for the NASA Soil Moisture Active Passive (SMAP) satellite. Key features of the PLIS radar are described. The ground swath of PLIS is such that the incidence angle ranges from 15 degrees from nadir on the near side of the swath to 45 degrees on the far side, resulting in an almost 3:1 variation in ground range resolution across the swath. Initial investigations into the impact of this on the statistics of backscattered data are presented. © 2011 KIEES.Doug Gray, Ruiting Yang, Heath Yardley, Jeffrey Walker, Bevan Bates, Rocco Panciera, Jorg Hacker, Andrew McGrath and Nick Stacyhttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=6086965&contentType=Conference+Publication
One Tree Reef topographic and bathymetric LiDAR digital elevation model (2018) and roughness equivalent habitat data (2023)
No full textA high-resolution LiDAR digital elevation model was developed to investigate the geomorphic features and surface roughness of a coral reef in the Southern Great Barrier (One Tree Reef). Given that there are few data sets of equivalent resolution the focus of this research was to detail the change in surface roughness expression over multiple spatial scales.
Data were collected 8 October 2018 using a Riegl VQ-820-G topo-bathymetric LiDAR combined with a Riegl Q680i-S topographic scanner and a Canon EOS 5Dmk4 DSLR on a small research aircraft (Diamond Aircraft ECO-Dimona). The whole One Tree Reef area was covered twice using two different pulse rate settings for the VQ-820-G, viz. 284kHz and 522kHz. This measurement strategy ensured maximum spatial resolution (at 522kHz) and maximum depth penetration (at 284kHz).
All LiDAR data was processed to a 0.25 m cell-size DEM using a combination of Riegl proprietary software, ARA-developed software, the RAPIDLASSO LAStools utilities, Bayesmap's StripAlign™ utility and Global Mapper V 20. Processing included human-machine interactive selection and confirmation of valid bathymetric points. The imagery from the DSLR was mosaiced at 0.14 m cell size using the AgiSoft PhotoScan© (now Metashape) Software package and overlaid onto the LiDAR point cloud. The relative error of the LiDAR point cloud was ± 0.1 m.
Two methods of characterising surface roughness were applied to the LiDAR DEM: the vector ruggedness measure (VRM) and the Multiscale Roughness (MR) tool from WhiteBox Tools. The VRM was applied over filter radii of 8, 20, 100 and 400 cells. The MR approach was conducted between filter radii of 1 – 1500 cells (≈ 0.5 to 750 m) with step intervals of 1.
MR analysis revealed the roughness signatures of the geomorphic coral reef zones defined by Roelfsema et al. (2018, doi:10.1016/j.rse.2018.02.005). Geomorphic zones with similar roughness signatures were combined to produce roughness equivalent habitats. Roughness equivalent habitats are regions with similar roughness signature that do not necessarily form geographical contiguous areas.
Data contained in this repository are: 1. The LiDAR DEM as a geotiff; 2. Roughness magnitude and scale geotiffs computed using the MultiscaleRoughness tool from Whitebox Tools and 3. The ESRI shapefiles for the roughness equivalent habitats. Further details of the results and analysis of the LiDAR DEM can be found in Harris et al. (2023, doi:/10.1016/j.geomorph.2023.108852)
Airborne Measurements of Gravity Wave Breaking at the Tropopause
No full text2000 FLORIDA AVE NW, WASHINGTON, DC,
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Unprecedented levels of ultrafine particles, major sources, and the hydrological cycle
No full textUltrafine particles (UFP) acting as cloud condensation nuclei (CCN) are the driving force behind changing rainfall patterns. Recently observed weather extremes like floods and drought might be due to changing anthropogenic UFP emissions. However, the sources and budgets of anthropogenic primary and secondary particles are not well known. Based on airborne measurements we identified as a major contribution modern fossil fuel flue gas cleaning techniques to cause a doubling of global primary UFP number emissions. The subsequent enhancement of CCN numbers has several side effects. It’s changing the size of the cloud droplets and delays raindrop formation, suppressing certain types of rainfall and increasing the residence time of water vapour in the atmosphere. This additional latent energy reservoir is directly available for invigoration of rainfall extremes. Additionally it’s a further contribution to the column density of water vapour as a greenhouse gas and important for the infrared radiation budget. The localized but ubiquitous fossil fuel related UFP emissions and their role in the hydrological cycle, may thus contribute to regional or continental climate trends, such as increasing drought and flooding, observed within recent decades
Ultrafine particles in the lower troposphere: major sources, invisible plumes and meteorological transport processes
No full textUltrafine particles in the atmosphere are key factors for aerosol cloud interaction as they affect cloud droplet size distributions, latent heat transport into elevated layers via droplet evaporation and precipitation properties via delayed raindrop generation and possibly invigoration of torrential rains. They are spatially and temporarily highly uneven distributed, suggesting the presence of strong sources either for primary particle emissions or for particle precursor materials. Airborne investigations now allowed to identify major anthropogenic primary particle sources, their strength and contribution to the ultrafine particle budget. Current industrial flue gas cleaning technologies favor the production of nucleation mode aerosol by gas to particle conversion which is emitted into mid elevations of the planetary boundary layer, transported over hundreds of km and vertically mixed by thermal convection on different time scales. These sources also emit a suitable mixture of sulphur and nitrogen compounds and ammonia, key components for aerosol nucleation from gas to particle conversion. Meteorological transport and the results of three dimensional in situ measurements explain both the spatial and temporal patterns of number and size distributions of ultrafine nucleation mode particles observed. Budget studies allow a comparison with recent emission szenarios. Results from clean and polluted environments and the potential impact of these ultrafine particles on the hydrological cycle will be discussed
REJOINDER TO BOETTKE ON COASEAN ECONOMICS AND COMMUNISM
No full textIn the view of Boettke (1998), Coase (1960) casts lights of understanding in a myriad of fields, including, preeminently, property rights theory and the Soviet system of economics. The claim of the present author, in sharp contrast, is that this seminal article of Coase’s is a snare and a delusion. It has led economists down a mistaken path for lo this past half century, and Boettke (1998) is but one more unfortunate example of this.Ronald Coase; Communism; Central Planning; Property Rights
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