Disparate dispersal limitation in Geomalacus slugs unveiled by the shape and slope of the genetic–spatial distance relationship

Long‐term dispersal ability is a key species’ trait constraining species ranges and thus large‐scale biodiversity patterns. Here we infer the long‐term dispersal abilities of three Geomalacus (Gastropoda, Pulmonata) species from their range‐wide genetic–spatial distance relationships. This approach follows recent advances in statistical modelling of the analogous pattern at the community level: the distance decay in assemblage similarity. While linear relationships are expected for species with high long‐term dispersal abilities, asymptotic relationships are expected for those with more restricted mobility. We evaluated three functional forms (linear, negative exponential and power‐law) for the relationship between genetic distance (computed from mitochondrial cox1 sequences, n = 701) and spatial distance. Range fragmentation at present time and at the Last Glacial Maximum was also estimated based on the projection of climatic niches. The power‐law function best fit the relationship between genetic and spatial distances, suggesting strong dispersal limitation and long‐term population isolation in all three species. However, the differences in slope and explained variance pointed to disparities in dispersal ability among these weak dispersers. Phylogeographic patterns of Geomalacus species are thus largely driven by the same major process (i.e. dispersal limitation), operating at different strengths. This strong dispersal limitation results in geographic clustering of genetic diversity that makes these species highly vulnerable to genetic erosion due to climate changThe authors were supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) through grant CGL2016‐76637‐P and fellowship IJCI‐2014‐20881 to CG‐RS

‘Omics’ approaches for crop improvement

The growing human population and climate change are imposing unprecedented challenges on the global food supply [1]. To cope with these pressures, crop improvement demands enhancing important agronomical traits beyond yield, such as adaptation, resistance, and nutritional value, by pivoting direct and indirect selection approaches [2]. The development of next-generation high-throughput screening technologies, referred to as ‘omics’, promises to speed up plant trait improvement [3] while producing more sustainable crops. Large-scale techniques, such as genomics, transcriptomics, proteomics, metabolomics, and phenomics, have already provided large datasets for that purpose. Meanwhile, modern bioinformatic and machine-learning approaches are helping us to process this heterogeneous hyper-dimensional data [4] while ultimately understanding the mechanisms behind agronomic features within the contemporary plant breeding triangle (i.e., genomics vs. phenomics vs. enviromics) [5]. ‘Omics’ datasets are also being generated to study macro-scale interactions and deepen our knowledge of crop behavior across the microbial [6] and environmental [7,8] continua. However, despite these massive technological and computational developments [4], systemic efforts to integrate ‘omics’ studies to understand biochemical pathways and cellular networks of crop systems are in their infancy [9], especially in orphan species [10]. Therefore, this Special Issue envisions offering updated emergent views on large-scale ‘omics’-based approaches. Specifically, the compilation explores the conceptual framework of the ‘omics’ paradigm [11], the practical uses of multiple ‘omics’ technologies, and their integration through trans-disciplinary bioinformatics as tools to improve qualitative and quantitative traits in a diverse panel of crop species

Sea Level in the Strait of Gibraltar: Tides

A network of tide gauges with eight observation recording points was in operation in the Strait of Gibraltar during the years 1984 and 1985, which made it possible to draw up detailed charts of the tides showing their refined structure. For the first order, the Strait of Gibraltar represents the nodal line of the stationary wave of the western Mediterranean, which, hypothetically, would end at the Cadiz meridian (6°17.0W). The tide is basically semi-diurnal; on average, 90% of the energy is associated with the second order and, for this, the Strait of Gibraltar tends to represent an antinode of the stationary wave, although the influence of the bottom topography and the rotation is interpreted in phase delays in the sill area (slightly progressive wave) and in increased non-linear constituents of higher orders. The radiational tide S is evaluated in the area studied and it is ascertained that it shows the same characteristics as the tides having strictly gravitational constituents, which implies that it is fundamentally co-oscillating. Order 4 displays characteristics of resonant amplification due to the existence of the free oscillation mode of the western Mediterranean basin the period of which is close to 6 hours. Of order 3 it should be stressed that M3, though small, is perfectly detectable in the area

Deformed Skyrme Crystals

The Skyrme crystal, a solution of the Skyrme model, is the lowest energy-per-charge configuration of skyrmions seen so far. Our numerical investigations show that, as the period in various space directions is changed, one obtains various other configurations, such as a double square wall, and parallel vortex-like solutions. We also show that there is a sudden "phase transition" between a Skyrme crystal and the charge 4 skyrmion with cubic symmetry as the period is gradually increased in all three space directions.Comment: 13 pages, 6 figures. To be published in JHE

Coastal Upwelling Off The Rias Bajas, Galicia, Northwest Spain I: Hydrographic Studies

Coastal upwelling occurs off the Rias Bajas of Spain between April and October. Superimposed on large-scale upwelling is a mesoscale regime of enhanced upwelling induced by topographic influences. We show that the region surrounding Cape Finisterre has intensified topographically induced upwelling. The rias have a relatively unobstructed connection with the open ocean. Upwelling of high nitrate water on the continental shelf by Ekman transport sets up pressure gradients at the mouth of the rias that induce upwelled water to flow into the rias. Deep water in the rias responds directly to cycles of upwelling and downwelling on the continental shelf

Valence Quark Distribution in A=3 Nuclei

We calculate the quark distribution function for 3He/3H in a relativistic quark model of nuclear structure which adequately reproduces the nucleon approximation, nuclear binding energies, and nuclear sizes for small nuclei. The results show a clear distortion from the quark distribution function for individual nucleons (EMC effect) arising dominantly from a combination of recoil and quark tunneling effects. Antisymmetrization (Pauli) effects are found to be small due to limited spatial overlaps. We compare our predictions with a published parameterization of the nuclear valence quark distributions and find significant agreement.Comment: 18pp., revtex4, 4 fig

First cases of gynandromorphism in Phlebotomus perniciosus Newstead, 1911 (Diptera, Psychodidae, Phlebotominae)

Two gynandromorphic specimens of Phlebotomus perniciosus Newstead, 1911 are described and illustrated for the first time The specimens were collected in the Northeast of the Iberian Peninsula (Spain)