| 1. |
- Araujo, Mario Jorge, et al.
(författare)
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Comparison of Sample Preparation Methods for Shotgun Proteomic Studies in Aquaculture Species
- 2021
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Ingår i: Proteomes. - : MDPI. - 2227-7382. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Proteomics has been recently introduced in aquaculture research, and more methodological studies are needed to improve the quality of proteomics studies. Therefore, this work aims to compare three sample preparation methods for shotgun LC-MS/MS proteomics using tissues of two aquaculture species: liver of turbot Scophthalmus maximus and hepatopancreas of Mediterranean mussel Mytilus galloprovincialis. We compared the three most common sample preparation workflows for shotgun analysis: filter-aided sample preparation (FASP), suspension-trapping (S-Trap), and solid-phase-enhanced sample preparations (SP3). FASP showed the highest number of protein identifications for turbot samples, and S-Trap outperformed other methods for mussel samples. Subsequent functional analysis revealed a large number of Gene Ontology (GO) terms in turbot liver proteins (nearly 300 GO terms), while fewer GOs were found in mussel proteins (nearly 150 GO terms for FASP and S-Trap and 107 for SP3). This result may reflect the poor annotation of the genomic information in this specific group of animals. FASP was confirmed as the most consistent method for shotgun proteomic studies; however, the use of the other two methods might be important in specific experimental conditions (e.g., when samples have a very low amount of protein).
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| 2. |
- Brodic, Bojan, et al.
(författare)
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Innovative seismic imaging of volcanogenic massive sulfide deposits, Neves-Corvo, Portugal - Part 1 : In-mine array
- 2021
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Ingår i: Geophysics. - : Society of Exploration Geophysicists. - 0016-8033 .- 1942-2156. ; 86:3, s. B165-B179
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate and upscale the feasibility of using exploration tunnels in an operating mine for active-source seismic imaging, a seismic experiment was conducted at the Neves-Corvo mine, in southern Portugal. Four seismic profiles were deployed in exploration drifts approximately 650 m beneath the ground surface, above the world-class Lombador volcanogenic massive sulfide deposit. In addition to the tunnel profiles, two perpendicular surface seismic profiles were deployed above the exploration tunnels. The survey was possible due to a newly developed prototype global positioning system (GPS) time transmitter enabling accurate GPS synchronization of cabled and nodal seismic recorders, below and on the surface. Another innovative acquisition aspect was a 1.65 t broadband, linear synchronous motor (LSM) driven - electric seismic vibrator (e-vib) used as the seismic source along two of the exploration tunnels. We have evaluated the challenges and innovations necessary for active-source tunnel seismic acquisition, characterized by high levels of vibrational noise from the mining activities. In addition, we evaluated the LSM vibrator's signal and overall seismic-data quality in this hard rock mining environment. Our processing results from the tunnel data and 3D reflection imaging of the Lombador deposit below the exploration tunnels were checked for consistency through constant-velocity 3D ray-tracing traveltime forward modeling. For imaging purposes, 3D Kirchhoff prestack depth and poststack time-migration algorithms were used, with both successfully imaging the targeted deposit. The results obtained show that active-source-seismic imaging using subsurface mining infrastructure of operational mines is possible. However, it requires innovative exploration strategies, a broadband seismic source, an accurate GPS-time system capable of transmitting GPS-time hundreds of meters below the surface, and careful processing. The results obtained open up possibilities for similar studies in different mining or tunneling projects.
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| 3. |
- Dias, Pedro, et al.
(författare)
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Geophysical investigation of the down-dip extension of the Lombador massive sulphide deposit, Neves-Corvo, Portugal
- 2021
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Ingår i: International journal of earth sciences. - : Springer Nature. - 1437-3254 .- 1437-3262. ; 110:3, s. 911-922
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Tidskriftsartikel (refereegranskat)abstract
- The 150 Mt Lombador massive sulphide deposit is one of the seven known deposits of the Neves-Corvo mine. The deposit dips approximately 30o-35o to the NE and is open down dip, with current exploitation reaching down at 1 km depth. To investigate the possible downwards continuation of the deposit, a 1D constrained inversion of time-domain electromagnetic (TEM) ground loop data was conducted, followed by 3D electromagnetic (EM) forward modeling and a constrained 3D gravimetric inversion over the same area. To perform the EM and gravity modeling/inversion, a 3D geologic model was built using a density database comprising of approximately 300 drill-holes, and an electrical conductivity database with measurements from resistivity surveys and 1D inversion of the TEM data. The EM modeling shows that the Neves Formation shales are a regional conductive layer extending down to approximately 1.6 km depth in the Lombador area. This layer, often topped by massive sulphides, has an average density of 2.83 g/cm(3), whereas stockwork and massive sulphide reach on average 3.1 g/cm(3) and 4.5 g/cm(3), respectively. The 3D constrained gravity inversion results do not support the hypothesis of the presence of massive sulphides located in the down-dip direction of the Lombador deposit in the immediate vicinity of the known deposit. The lack of spatial resolution of the gravity grid, the study area limited size and the lack of information from within the basement suggest further studies are required to confirm the presence and amount of stockwork mineralization down-dip the Lombador deposit inside the Neves-Formation or the Phyllite-Quartzite basement.
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| 4. |
- Donoso, George A., et al.
(författare)
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Innovative seismic imaging of volcanogenic massive sulfide deposits, Neves-Corvo, Portugal – Part 2 : Surface array
- 2021
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Ingår i: Geophysics. - : Society of Exploration Geophysicists. - 0016-8033 .- 1942-2156. ; 86:3, s. B181-B191
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Tidskriftsartikel (refereegranskat)abstract
- Seismic methods are an affordable and effective way of studying the subsurface for mineral exploration. With the goal of testing new technologies for mineral exploration in highly challenging mining areas, in early 2019, an innovative seismic survey was conducted at the Neves-Corvo mine, south Portugal. We have focused on the data and results from the surface array data, whereas other work deals with the underground seismic data. The surface seismic survey consisted of two perpendicular 2D profiles positioned above the known world-class tier-1 Lombador deposit. Simultaneously, a survey inside the active underground mine took place, being unique because it included the testing of a prototype system that enabled accurate GPS-time (microsecond accuracy) synchronization inside the mine tunnels, approximately 650 m below the surface profiles. Due to the active mining operations, the surface data are noisy. To handle this, a carefully tailored processing algorithm was developed and applied to enhance reflections in the data, interpreted to originate from lithologic contacts and the Lombador deposit. The results and interpretations from 2D processing were validated taking advantage of the known deposit geometry using 3D exploding reflector modeling and pseudo-3D cross-dip analysis. These analyses suggest that there is an out-of-plane signature of the Lombador deposit on the surface data. Additionally, source points activated in the exploration tunnels and simultaneously recorded on the surface profiles allowed for the creation of a 2D velocity model that was used for migration and time-to depth conversion, providing a reliable 2D seismic section of the subsurface under the surface profiles. We determine that limited surface coverage 2D surveys and a velocity model derived from the tunnel-to-surface seismic recordings allow for imaging of key subsurface geologic structures and delineating mineral deposits of economic interest.
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