Land subsidence associated with overexploitation of aquifers is a hazard that commonly affects large areas worldwide. The Lorca area, located in southeast Spain, has undergone one of the highest subsidence rates in Europe as a direct consequence of long-term aquifer exploitation. Previous studies carried out on the region assumed that the ground deformation retrieved from satellite radar interferometry corresponds only to vertical displacement. Here we report, for the first time, the two- and three-dimensional displacement field over the study area using synthetic aperture radar (SAR) data from Sentinel-1A images and Global Navigation Satellite System (GNSS) observations. By modeling this displacement, we provide new insights on the spatial and temporal evolution of the subsidence processes and on the main governing mechanisms. Additionally, we also demonstrate the importance of knowing both the vertical and horizontal components of the displacement to properly characterize similar hazards. Based on these results, we propose some general guidelines for the sustainable management and monitoring of land subsidence related to anthropogenic activities.

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Abstract:The essential oil composition of Peumus boldus and Drimys winterii was analyzed by means of capillary GC-FID and GC-MS. More than 96% of the total oil components (43 and 54 compounds, respectively) were identified, with ascaridole (51.17 ± 9.51), p-cymene (16.31 ± 2.52) and 1,8-cineole (14.45 ± 2.99) as the main compounds in P. boldus and -eudesmol (21.65 ± 0.41), followed of elemol (12.03 ± 0.34) and terpinen-4-ol (11.56 ± 1.06) in D. winterii. The herbicidal activity was tested against Amaranthus hybridus and Portulaca oleracea. P. boldus essential oil was the most phytotoxic against both weeds, inhibiting seed germination and seedling growth at all concentrations assayed (0.125-1 µL/mL). D. winterii essential oil did not show any effect on A. hybridus germination and only affected P. oleracea germination at the highest concentration. The results suggest the possible use of the essential oil from P. boldus as a natural herbicide.

A method has been developed for the regeneration of the banana cultivar Dwarf Brazilian (Musa spp. AAB group). Primary somatic embryos were produced when explants of immature male flower buds were cultured on Murashige and Skoog (MS) medium plus 1 mg/l biotin, 100 mg/l malt extract, 100 mg/l glutamine, 4 mg/l 2,4-dichlorophenoxyacetic acid, 1 mg/l indole-3-acetic acid (IAA), 1 mg/l α-naphthaleneacetic acid, 30 g/l sucrose and 2.6 g/l Phytagel, pH 5.8 (M1 medium) and then transferred to M1 medium plus 200 mg/l casein hydrolysate and 2 mg/l proline. Subsequent transfer to MS supplemented with 10% coconut water produced rapidly proliferating embryogenic callus that developed into secondary somatic embryos (SE 2 ); these were subcultured on half-strength MS supplemented with 5 mg/l 6-benzylaminopurine (BA). Differentiated embryos were transferred to MS medium supplemented with 5 mg/l BA for development, and mature SE 2 were isolated and cultured on hormone-free MS for germination and development into plantlets. Approximately 90% of the SE 2 germinated and developed into plantlets, and these were subcultured onto MS medium plus 0.1% activated charcoal, 1 mg/l BA and 1 mg/l IAA where complete plantlets developed. Morphologically normal banana plants developed from all of the regenerated plantlets, the first of which were produced within 6 months of culture initiation.

Flying wings are one of the most promising concepts regarding the ever-increasing air traffic demand. Furthermore, they help improving economic efficiency and are environmentally friendly, both in terms of emissions and noise. In the first place, the paper deals about the initial design of a medium size C-type flying wing, of the 300-seat class, showing that the aircraft is operationally efficient, and can beat conventional airplanes of similar capacity. It specifically exhibits some considerable gains in field and cruise performances. Second, the paper addresses the potential of some emerging technologies, such as laminar flow control, vectored thrust, and active stability, which provide additional improvements and allow the simplification of the original configuration to a U-type arrangement. A preliminary assessment of emergency evacuation is included.

Aeronautics and astronautics are two closely related disciplines, sometimes found under the joint term aerospace, that have progressed at a formidable pace during the 20th century. Their impact on society is overwhelming. For example, the aeroplane, the core of aeronautics, has been identified as one of the three major inventions of that century. On its turn, satellites have paved the way for modern globalization. Major drivers leading this progress have changed from the classical motto ‘higher, further, faster’ to the current ‘more affordable, cleaner, quieter’, but safety has always been kept the undisputed number one. The underlying key factors for progress have been and still are excellence and co-operation. Both aeronautics and astronautics are multidisciplinary in nature and, accordingly, this review summarizes relevant advances and trends in pertinent fields: aerodynamics, structures, propulsion, and so on. All these fields are still very healthy and the 21st century will witness again a new era of astonishing aerospace developments.

Aircraft have greatly changed over the last decades, mainly due to astonishing developments in key technological areas. The present note attempts to correlate the evolution of jet airliners with improvements in aerodynamics and propulsion. A simple model is elaborated from the range equation, taking the main magnitudes of the payload—range diagram as input data. Results show the robustness and potential of such procedures.

Compensation growth and chemical defense are two components of plant defense strategy against herbivores. In this study, compensation growth and the response of primary and secondary metabolites were investigated in Brassica rapa plants subjected to infestation by two herbivores from contrasting feeding guilds, the phloem-feeding aphid Brevicoryne brassicae and the leaf-feeding caterpillar Pieris brassicae. These specialist herbivores were used at two different densities and allowed to feed for seven days on a young caged leaf. Changes in growth rates were assessed for total leaf area and bulb mass, whereas changes in primary and secondary metabolites were evaluated in young and mature leaves, roots, and bulbs. Mild stress by caterpillars on young plants enhanced mean bulb mass and elicited a contrasting regulation of aliphatic and indolic glucosinolates in the leaves. In contrast, mild stress by aphids enhanced leaf growth and increased glucosinolate concentrations in the bulb, the most important storage organ of B. rapa. A similar mild stress by either herbivore to older plants did not alter plant growth parameters or concentrations of the metabolites analyzed. In conclusion, Brassica plant growth was either maintained or enhanced under mild herbivore stress, and defense patterns differed strongly in response to herbivore type and plant development stage. These results have implications for the understanding of plasticity in plant defenses against herbivores and for the management of Brassica rapa in agroecosystems.