Explore the vast range of titles available.

We present Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA) observations of the close (0.″3 = 90 au separation) protobinary system SVS 13. We detect two small circumstellar disks (radii ∼12 and ∼9 au in dust, and ∼30 au in gas) with masses of ∼0.004–0.009 M ☉ for VLA 4A (the western component) and ∼0.009–0.030 M ☉ for VLA 4B (the eastern component). A circumbinary disk with prominent spiral arms extending ∼500 au and a mass of ∼0.052 M ☉ appears to be in the earliest stages of formation. The dust emission is more compact and with a very high optical depth toward VLA 4B, while toward VLA 4A the dust column density is lower, allowing the detection of stronger molecular transitions. We infer rotational temperatures of ∼140 K, on scales of ∼30 au, across the whole source, and a rich chemistry. Molecular transitions typical of hot corinos are detected toward both protostars, being stronger toward VLA 4A, with several ethylene glycol transitions detected only toward this source. There are clear velocity gradients, which we interpret in terms of infall plus rotation of the circumbinary disk, and pure rotation of the circumstellar disk of VLA 4A. We measured orbital proper motions and determined a total stellar mass of 1 M ☉. From the molecular kinematics, we infer the geometry and orientation of the system, and stellar masses of ∼0.26 M ☉ for VLA 4A and ∼0.60 M ☉ for VLA 4B.

The dragonfly Trithemis kirbyi Sélys, 1891 recently colonized Western Europe from North Africa. Since its first record in the Iberian Peninsula in 2007, the species has been spreading northward and has become naturally established in the central and eastern Iberian Peninsula, the Balearic Islands and southern France. Despite its worldwide distribution, its rapid colonization of the western Mediterranean area occurred only very recently. The aims of this study were to evaluate (1) whether the species’ colonization of the western Mediterranean is related to climate change and rising temperatures, specifically the summer warming peaks that have occurred in the last decade, (2) which climatic variables have most influenced its distribution and dispersal, and (3) its potential future dispersal and colonization capacity towards the eastern Mediterranean. We found that the dispersal and recent establishment of T . kirbyi in southwestern Europe strongly depends on increasing temperatures, particularly summer temperature peaks, which has allowed this species to disperse farther and more effectively than during years with average summer temperatures. The most important variable in the suitability models is the minimum temperature of the coldest month, which, in recent decades, has become less of a limiting factor for ectotherms. According to the models, suitable areas for the species are currently found throughout the eastern Mediterranean parts of Europe, and it is likely that it can naturally colonize these areas as it did in the Iberian Peninsula. Trithemis kirbyi is a model of how climate change and observed rising temperatures have turned previously inhospitable regions into suitable areas for exotic species, which may successfully colonize them naturally if they can reach these promising lands on their own. However, this study serves as a warning that such species can also colonize these new regions with a little help from unsuspecting means, which are often responsible for the increasingly common presence of invasive, noxious taxa in Europe.

It is well known that biodiversity data from historical inventories presents important geographic and taxonomic biases. Due to this, current knowledge on the distribution of most species could be incomplete and biased. We assess how the biases in historical biodiversity data might affect the description of the environmental niche of the species, using exhaustive data on the distribution of dung beetles in Madrid as a case study. We describe the historical process of survey and compare such historical data with the results of an exhaustive survey, identifying the environmental biases in the historical surveys during different periods, and assessing the completeness of the environmental niche of the species provided by historical data through time. Events like the Spanish Civil War affect the tempo and spread of surveys, but the exhaustive work since 1970 provides a good, though incomplete, coverage of the region by 1998. In spite of this, the biases in historical data result in a limited knowledge about the niche of an important number of species. Although nearly a half of the species had the 100% of their niche covered by data in 1998, roughly a third had less than 75%, nearly a fourth less than 50%, and 18 species had to be excluded from the analyses due to the lack of data. Our results point out that data from non-standardized inventories often provide an incomplete description of the environmental responses of most species. Due to this, we highlight that currently predictive models of species distributions present some limitations, since the results of models based in partial information about the environmental niche of the species will be compromised. Therefore, the biases in the available data must be evaluated before constructing predictive maps of species distributions, and taken into account when drawing conclusions or conservation strategies from these maps.

We report here the first mapping of SiO v = 1 J = 5 → 4 maser emission toward the “water fountain” source W 43A in order to explore the central stellar system driving the collimated, bipolar, fast jet. The maser source has a systemic line-of-sight velocity consistent with that of CO J = 2 → 1 emission tracing the jet within ∼2 km s−1 but a velocity gradient opposite that of the jet. The dynamical center of the maser source is located within ∼10 mas (or ∼20 au) of the brightness peak of the central 1.3 mm continuum emission. The spatiokinematic properties of the SiO J = 5 → 4 and J = 1 → 0 masers suggest that they are associated with the root of a slow (10 km s−1 < Voutflow << 100 km s−1) outflow with a large opening angle, and the central stellar system is contained within the inner maser region (∼20 au) during a possible common-envelope evolution.

Diplolepis (Hymenoptera: Cynipidae) are gall wasps that induce conspicuous galls on Rosa spp. (Rosaceae). These species are distributed globally and in Europe some are especially common and are founder organisms of biological communities composed of different insects. However, the ecological niches of these species have not been studied in detail. We modelled the potential distributions of these species using the locations of the galls of the four most abundant species of Diplolepis on the Iberian Peninsula (Diplolepis mayri, Diplolepis rosae, Diplolepis eglanteriae and Diplolepis nervosa, the galls of latter two are indistinguishable) using four different algorithms and identifi ed the resulting consensus for the species. We compared the potential distributions of these species, considering their spatial complementarity and the distributions of their host plants. We found that D. mayri and D. eglanteriae/nervosa have complementary distributions on the Iberian Peninsula. The former species is found in the Mediterranean region, while D. eglanteriae and D. nervosa are distributed mainly in the Eurosiberian region. Diplolepis rosae has the widest distribution on the Iberian Peninsula. Our models constitute the fi rst effort to identify suitable areas for species of Diplolepis species on the Iberian Peninsula and could be useful for understanding the evolutionary ecology of these species throughout their distribution in the western Palearctic.

Reach for the stars There are two competing theories to explain how high-mass stars form: either they arise from mergers of low-mass younger stellar objects or, like low-mass stars, they arise by accretion from a circumstellar disk. The latter theory gets a boost from new observations of disks of dust and molecular gas around two high-mass protostars. A 15-solar-mass protostar in the Cepheus A region, and the 7-solar-mass Becklin–Neugebauer object in the famous star-forming region in Orion appear well on the way to star formation by accretion. The processes leading to the birth of low-mass stars such as our Sun have been well studied 1 , but the formation of high-mass (over eight times the Sun's mass, M ⊙ ) stars remains poorly understood 2 . Recent studies suggest that high-mass stars may form through accretion of material from a circumstellar disk 3 , in essentially the same way as low-mass stars form, rather than through the merging of several low-mass stars 4 . There is as yet, however, no conclusive evidence 5 , 6 . Here we report the presence of a flattened disk-like structure around a massive 15 M ⊙ protostar in the Cepheus A region, based on observations of continuum emission from the dust and line emission from the molecular gas. The disk has a radius of about 330 astronomical units ( au ) and a mass of 1 to 8 M ⊙ . It is oriented perpendicular to, and spatially coincident with, the central embedded powerful bipolar radio jet, just as is the case with low-mass stars, from which we conclude that high-mass stars can form through accretion.

Dryocosmus kuriphilus (Hymenoptera: Cynipidae), also known as the Asian chestnut gall wasp, is a non-native invasive species that has recently appeared in many regions of Europe, including the Iberian Peninsula. This species is an important pest of chestnut trees in several regions and is of concern for foresters in these areas. The results of this research revealed 14 different hotspots of infestation of D. kuriphilus and resulted in the development of models that predict the distribution of D. kuriphilus in Spain over the next 37 years (2019-2055). These results indicate a rapid spread in all Spanish chestnut forests and identify areas that are theoretically highly suitable and susceptible to colonization by this cynipid based on predictions of three different niche models. Although D. kuriphilus is able to induce galls on all chestnut trees, the models indicate that there are differences in the suitability of the different regions for this species. This differential suitability results in some areas having better environmental conditions than others for D. kuriphilus, which is a factor that should be taken into account in its management and biological control. This study of the current distribution, patterns of dispersal using GIS and potentially suitable areas for D. kuriphilus, using niche models will assist in the management and control of this pest in Spain.

One of the most poorly understood stellar evolutionary paths is that of binary systems undergoing common-envelope evolution, when the envelope of a giant star engulfs the orbit of a companion. The interaction that ensues leads to a great variety of astrophysical systems and associated phenomena, but happens over a very short timescale. Unfortunately, direct empirical studies of this momentous and complex phase are difficult at present because few objects experiencing, or having just experienced, common-envelope evolution are known. Here we present Atacama Large Millimeter/submillimeter Array observations of minor CO isotopologues towards a sample of sources known as water fountains, which reveal that almost all of them recently lost a substantial fraction of their initial mass over a timescale of less than a few tens to a few hundreds of years. The only known mechanism able to explain such rapid mass ejection, corresponding to a large fraction of the stellar mass, is the common-envelope evolution. A stellar population analysis shows that the number of water-fountain sources in the Milky Way is comparable to the expected number of common-envelope events that involve low-mass evolved stars. Thus, the known sample of water-fountain sources accounts for a large fraction of the systems undergoing a common-envelope phase in our Galaxy. As one of the distinguishing characteristics of water-fountain sources is their fast bipolar outflow, we conclude that outflows and jets play an important role right before, during or immediately after the common-envelope phase. Observations of some so-called ‘water fountain’ stars show that they appear to have lost a large fraction of their initial mass in a very short time (hundreds of years). This leads Khouri et al. to suggest that these sources have undergone the poorly understood process of common-envelope evolution, where the envelope of one star engulfs that of its companion.

In countries with limited resources, a relative, but particularly absolute increase in the number of patients requiring ICU may overcome existing infrastructures [3,4]. The trend shows that a still increasing daily number of new cases (Fig. 1), but from the total, 1807 cases (22.7%) have recovered (negative follow-up RT-PCR) and 358 (4.5%) have died. The MoH has proposed a four-phase plan including an amplification of the installed capacity (releasing 50% of the ICU beds, to make 2650 beds available) (phase 1), optimize the installed capacity (conversion of 2500 intermediate care units to ICU providing mechanical ventilation) (phase 2), extension of the installed capacity (creation of 2500 new ICU) (phase 3), and the critical extension (with 2,176 additional new ICU) (phase 4), to finally have 9826 ICU beds (an increase of 371%).

Observations in the millimetre bands of maser-emitting planetary nebulae (PNe) are crucial to study their circumstellar molecular gas at the beginning of the PN phase. Maser-emitting PNe are in the earliest phases of PN formation; therefore, these sources are key objects to study the molecular content during the early evolution of PNe. These circumstellar envelopes are active sites for the formation of molecules. We present preliminary results of millimetre observations with the IRAM 30 m telescope towards one PN (IRAS 17393−2727) of a sample of five maser-emitting PNe, where we detect 12CO and 13CO lines in both J=1→0 and J=2→1 transitions.