The taxonomic status of the genus <i>Stylactaria</i> Stechow, 1921 (Hydroidomedusae, Anthomedusae, Hydractiniidae), with the description of a new species

The status of all the species ascribed in the literature to Stylactaria is discussed, that nominal genus is considered a congener of Hydractinia and a new species (Hydractinia calderi n. sp.) is described. The medusae of the medusa-based genera Hansiella and Tregoubovia, formerly ascribed to the Hydractiniidae, are shown to be more like the medusae of Thecocodium, a genus having ptilocodiid hydroids. Both Hansiella and Tregoubovia are thus transferred to the Ptilocodiidae.With their removal from the Hydractiniidae, a redefinition of both families is provided. The genus Fiordlandia is considered as synonym of Clavactinia

Crop diversification and digestate application effect on the productivity and efficiency of irrigated winter crop systems

Irrigated winter crops can reduce input demands when compared with irrigated summer cropping systems in the Mediterranean area. The sustainability of these systems can be further improved resorting to diverse rotations, but also to fertilisation with digestate, a by-product from anaerobic digestion of organic waste. Post-treatments such as drying and acidifying can improve the fertiliser value of this product. In this study, we compare wheat performance in a three-year full cereal rotation or in a diverse rotation, with pea and canola. Besides, untreated and dried acidified digestates are tested as fertilisers for all crops, comparing to mineral fertilisation at a rate of 140 kg N ha−1 and a control with no fertilisation. To assess productivity and efficiency of the different systems, grain yield and N concentration, N uptake efficiency (NUpE) and water use efficiency (WUE) were determined, along with soil nitrate dynamics and total N at the end of the experiment. Results showed an average wheat yield increase of 1.79 t ha−1 by the last year of the diverse crop rotation rather than the cereal rotation (p < 0.001). Although there was no yield increase in the previous year, wheat after pea showed higher grain N concentration (p < 0.001). However, the NUpE of wheat remained steady due to a higher soil N availability after pea, which suggests that fertilisation can be adjusted. Although wheat WUE increased due to canola and pea precedents (p < 0.001), the cereal rotations should be more adapted to systems with low water availability. Nonetheless, both rotations required about 30% of irrigated water than the typical irrigated summer crops of the Ebro valley region. Fertiliser effect on yields was variable according to the tested crop mainly due to differences in N demand along each growing cycle. Overall, dried acidified digestate application resulted in similar soil nitrate levels than the mineral fertiliser. The diverse rotation raised soil nitrates content compared to the cereal rotation at sowing and harvesting times (p = 0.002 and p < 0.001, respectively). Higher soil nitrate levels were found when associating these two practices, while nitrate levels after mineral fertilisation showed to be less dependent on the implemented rotation. The diverse rotation also raised soil total N at the end of the experiment (p = 0.023). Similarly, the dried acidified digestate application resulted in higher soil total N than mineral fertilisation (p = 0.011). These findings show how these management practices should allow for a chemical fertilisation reduction in irrigated winter crop systems.This work was supported by the European Union’s Horizon 2020 Research and Innovation programme [Grant Agreement No. 773649] and by the State Agency of Research (Spain) [Projects AGL 2017/84529-C3–3R and PID 2021–126343OB-C33]. G. Nascimento is recipient of an UdL-IRTA PhD fellowship. The IRTA authors acknowledge the CERCA programme (Generalitat de Catalunya) contribution.info:eu-repo/semantics/publishedVersio

A census of ρ\rho Oph candidate members from Gaia DR2

The Ophiuchus cloud complex is one of the best laboratories to study the earlier stages of the stellar and protoplanetary disc evolution. The wealth of accurate astrometric measurements contained in the Gaia Data Release 2 can be used to update the census of Ophiuchus member candidates. We seek to find potential new members of Ophiuchus and identify those surrounded by a circumstellar disc. We constructed a control sample composed of 188 bona fide Ophiuchus members. Using this sample as a reference we applied three different density-based machine learning clustering algorithms (DBSCAN, OPTICS, and HDBSCAN) to a sample drawn from the Gaia catalogue centred on the Ophiuchus cloud. The clustering analysis was applied in the five astrometric dimensions defined by the three-dimensional Cartesian space and the proper motions in right ascension and declination. The three clustering algorithms systematically identify a similar set of candidate members in a main cluster with astrometric properties consistent with those of the control sample. The increased flexibility of the OPTICS and HDBSCAN algorithms enable these methods to identify a secondary cluster. We constructed a common sample containing 391 member candidates including 166 new objects, which have not yet been discussed in the literature. By combining the Gaia data with 2MASS and WISE photometry, we built the spectral energy distributions from 0.5 to 22\microm for a subset of 48 objects and found a total of 41 discs, including 11 Class II and 1 Class III new discs. Density-based clustering algorithms are a promising tool to identify candidate members of star forming regions in large astrometric databases. If confirmed, the candidate members discussed in this work would represent an increment of roughly 40% of the current census of Ophiuchus.Comment: A&A, Accepted. Abridged abstrac

Characterization of quaternary ammonium compounds in Flourensia xerophytic communities and response to UV-B radiation

As part of ongoing studies aimed at characterizing molecular components involved in the ecophysiological adaptations of native xerophytic plants from central Argentina, we demonstrated the presence of compatible solutes in Flourensia campestris (FC) and Flourensia oolepis (FO), specifically glycine betaine (GB) through TLC, LC, 1H NMR and 13C-NMR. GB content (leaves: 38±7μmolg-1 DW; adult plants>seedlings), and distribution (capitula>vegetative leaves>reproductive leaves>shoots>roots) were similar to other quaternary ammonium compound (QAC) accumulators. Flourensia seedlings from both species protected from UV-B exposure - a major abiotic stress in these natural environments - showed a significant increase of GB in the leaves (p<0.01) and a significant decrease in the roots (p<0.05). In FC and FO xerophytic shrub-dominated communities QACs were detected for the first time in 41% of co-occurring species (N=39), 14 of 28 natives (50%) and 2 of 11 exotics (18%), being GB in natives only (57% of QAC accumulators). GB may be considered as a chemotaxonomical character for the genus Flourensia, since it was also detected in Flourensia hirta, Flourensia niederleinii, Flourensia riparia, Flourensia fiebrigii, Flourensia macroligulata and Flourensia heterolepis. Our controlled UV-B experiments, set up in the same natural environment where these species grow, clearly show that solar UV-B - and therefore oxidative stress - is involved in regulating GB contents and within-plant distribution in FC and FO seedlings. The findings in Flourensia co-occurring native species suggest that QACs accumulation may be considered as a community-specific ecophysiological trait in these xerophytic environments. .Fil: Piazza, Leonardo A.. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: López, D.. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Silva, Mariana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Lopez Rivilli, Marisa Juana. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cantero, Juan Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Tourn, G. M.. Universidad de Buenos Aires. Facultad de Agronomia. Sede Polo Universitario Punilla Centro; ArgentinaFil: Scopel, Ana Leonor. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Deep learning in automated ultrasonic NDE -- developments, axioms and opportunities

The analysis of ultrasonic NDE data has traditionally been addressed by a trained operator manually interpreting data with the support of rudimentary automation tools. Recently, many demonstrations of deep learning (DL) techniques that address individual NDE tasks (data pre-processing, defect detection, defect characterisation, and property measurement) have started to emerge in the research community. These methods have the potential to offer high flexibility, efficiency, and accuracy subject to the availability of sufficient training data. Moreover, they enable the automation of complex processes that span one or more NDE steps (e.g. detection, characterisation, and sizing). There is, however, a lack of consensus on the direction and requirements that these new methods should follow. These elements are critical to help achieve automation of ultrasonic NDE driven by artificial intelligence such that the research community, industry, and regulatory bodies embrace it. This paper reviews the state-of-the-art of autonomous ultrasonic NDE enabled by DL methodologies. The review is organised by the NDE tasks that are addressed by means of DL approaches. Key remaining challenges for each task are noted. Basic axiomatic principles for DL methods in NDE are identified based on the literature review, relevant international regulations, and current industrial needs. By placing DL methods in the context of general NDE automation levels, this paper aims to provide a roadmap for future research and development in the area.Comment: Accepted version to be published in NDT & E Internationa

Spatio-temporal variation of surface soil hydraulic properties under different tillage and maize-based crop sequences in a Mediterranean area

Aims: The surface crust formed by the drop impact of rainfall and/or irrigation is a prevalent characteristic in many Mediterranean soils. However, the temporal variation of soil hydraulic properties induced by surface crust during the high-frequency irrigation has rarely been investigated. Methods: Beerkan infiltration tests in conjunction with the BEST method were used to investigate the effects of surface crusting on the spatio-temporal variation of saturated soil hydraulic conductivity (Ks, mm s−1), sorptivity (S, mm s−0.5), mean pore size (r, mm), number of effective pores per unit area (N, m−2) in Agramunt, NE Spain. Results: In response to autumn tillage, intensive tillage (IT) increased Ks and S due to higher r and N, but both declined after 60&nbsp;days. Reduced tillage (RT), maintained comparable Ks and S values, despite having a lower N value. After the spring tillage, both IT and RT developed crusted layers, resulting in decreased Ks, S and N. Long-term no-tillage (NT) showed an increasing trend of Ks and S over time, except for the last sampling. Spatial variation (i.e., between the rows, B-row vs. within the row of crops, W-row) of Ks and S was found, and non-crusted soils (W-row) had consistently higher Ks and S than crusted soils (B-row). Conclusions: Conservation tillage i.e., RT and NT improve the surface soil structure and reduce the risk of crust development. Surface cover by crops may help to prevent crust formation within the row of crops, improving soil hydraulic conductivity

On the definition, evolution, and properties of the outer edge of gravity currents: A direct-numerical and large-eddy simulation study

Gravity currents are flows driven by the action of gravity over fluids with different densities. Here, we focus on gravity currents where heavier fluid travels along the bottom of a sloping bed, underneath a large body of stagnant lighter ambient fluid. The thickness of the current increases due to entrainment of ambient fluid into the current. Direct numerical and large eddy simulations of gravity currents and a wall-jet transporting a passive scalar field are performed. We focus on the rate of penetration of mean momentum and mean concentration of the agent responsible for the density difference (temperature, salinity, or sediment volume fraction) into the ambient fluid. The rates of penetration of turbulence-related quantities (i.e., turbulent kinetic energy, Reynolds flux, and stress) into the ambient are analyzed. A robust methodology for defining the upper edge of these quantities and thereby defining the current thickness using these different mean and turbulent quantities is presented. A comparison between downstream evolution of the gravity current with the corresponding behaviors of canonical wall-bounded turbulent flows is presented. The present understanding of turbulent/non-turbulent interface (TNTI) is extended to include subcritical flows where, due to the strong effect of stratification, the TNTI is buried well within the upper edge of the current and confined right above the inner near-bed layer. The present work sheds light on the striking difference between the different definitions of thickness (momentum, concentration, turbulence, etc.) in subcritical gravity currents, where stratification suppresses turbulence in the upper region of the current.Fil: Salinas, Jorge S.. University of Florida; Estados UnidosFil: Balachandar, S.. University of Florida; Estados UnidosFil: Zúñiga, Santiago Luciano. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shringarpure, M.. No especifíca;Fil: Fedele, J.. No especifíca;Fil: Hoyal, D.. No especifíca;Fil: Cantero, Mariano Ignacio. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin