Vortices on demand in multicomponent Bose-Einstein condensates

We present a simple mechanism to produce vortices at any desired spatial locations in harmonically trapped Bose-Einstein condensates (BEC) with multicomponent spin states coupled to external transverse and axial magnetic fields. The vortices appear at the spatial points where the spin-transverse field interaction vanishes and, depending on the multipolar magnetic field order, the vortices can acquire different predictable topological charges. We explicitly demonstrate our findings, both numerically and analytically, by analyzing a 2D BEC via the Gross-Pitaevskii equation for atomic systems with either two or three internal states. We further show that, by an spontaneous symmetry breaking mechanism, vortices can appear in any spin component, unless symmetry is externally broken at the outset by an axial field. We suggest that this scenario may be tested using an ultracold gas of $^{87}$Rb occupying all three $F = 1$ states in an optical trap.Comment: 11 pages, 9 figures, (Accepted in PRA

New hermit crabs (Paguroidea, Anomura) from the Eocene of Huesca, Spain

A new genus and two new species of fossil hermit crabs (Anomura, Paguroidea) are described from the southern Pyrenean basins (Huesca, NE Spain). Parapetrochirus nov. with P. robustus n. gen., n. sp., as type species, comes from the lower Eocene (Ypresian) Roda Formation. It preserves both chelipeds exhibiting a notable heterochely, a larger left cheliped and a concavity without granulation in the inner upper portions. Eocalcinus gerardbretoni n. sp. comes from the highest levels of the Arguis Formation (Priabonian) in Yeste locality. This species is characterized by a hemispherical outline and a sinuous lower margin of the chela, which differs from the type species of the genus. The cheliped morphology of such species allows inclusion in the families Diogenidae and Calcinidae, respectively. Fossil paguroids are relatively rare in the Eocene of Spain, therefore, the description of these two new taxa increases the known diversity of this group. Parapetrochirus robustus n. gen., n. sp. inhabited siliciclastic substrates within a prodelta environment and E. gerardbretoni n. sp. was collected from the last levels of coral rudstones just below the continental influence of Yeste-Arrés Formation. En este trabajo se describe un nuevo género y dos nuevas especies de cangrejos ermitaños fósiles (Anomura, Paguroidea) correspondientes a las cuencas del sur de los Pirineos en la Huesca, noreste de España. Parapetrochirus nov., con P. robustus n. gen., n. sp. como especie tipo procede del Eoceno inferior (Ypresiano) de la Formación Roda. Este fósil preserva ambos quelípedos con una notable heteroquelia, un quelípedo izquierdo más grande y una superficie cóncava sin granulaciones en las porciones superiores internas. Eocalcinus gerardbretoni n. sp., procede de los niveles más altos de la Formación Arguis (Priaboniano) en la localidad de Yeste. Éste se caracteriza por su forma hemisférica y un margen inferior sinuoso de la quela, lo cual difiere de la especie tipo del género. La morfología del quelípedo de estas especies permite su inclusión en las familias Diogenidae y Calcinidae, respectivamente. Los paguroideos fósiles son relativamente raros en el Eoceno de España, por tanto, la descripción de estos dos nuevos taxones fósiles incrementa la diversidad conocida del grupo. Parapetrochirus robustus n. gen., n. sp. habitaba en los sustratos siliciclásticos de ambiente prodelta y E. gerardbretoni n. sp. fue recolectado en los últimos niveles de los rudstones coralinos, justo debajo de la influencia continental de la Formación Yeste-Arrés

Clear evidence for the presence of second-generation asymptotic giant branch stars in metal-poor Galactic globular clusters

Galactic globular clusters (GCs) are known to host multiple stellar populations: a first generation with a chemical pattern typical of halo field stars and a second generation (SG) enriched in Na and Al and depleted in O and Mg. Both stellar generations are found at different evolutionary stages (e.g., the main-sequence turnoff, the subgiant branch, and the red giant branch). The non detection of SG asymptotic giant branch (AGB) stars in several metal-poor ([Fe/H] < -1) GCs suggests that not all SG stars ascend the AGB phase, and that failed AGB stars may be very common in metal-poor GCs. This observation represents a serious problem for stellar evolution and GC formation/evolution theories. We report fourteen SG-AGB stars in four metal-poor GCs (M 13, M 5, M 3, and M 2) with different observational properties: horizontal branch (HB) morphology, metallicity, and age. By combining the H-band Al abundances obtained by the APOGEE survey with ground-based optical photometry, we identify SG Al-rich AGB stars in these four GCs and show that Al-rich RGB/AGB GC stars should be Na-rich. Our observations provide strong support for present, standard stellar models, i.e., without including a strong mass-loss efficiency, for low-mass HB stars. In fact, current empirical evidence is in agreement with the predicted distribution of FG and and SG stars during the He-burning stages based on these standard stellar models.Comment: Accepted for publication in The Astrophysical Journal Letters (16 pages, 4 figures, and 1 table

Cryptography using evolutionary computing

We present a method of generating encryptors, in particular, Pseudo Random Number Generators (PRNG), using evolutionary computing. Working with a system called Eureqa, designed by the Cornell Creative Machines Lab, we seed the system with natural noise sources obtained from data that can include atmospheric noise generated by radio emissions due to lightening, for example, radioactive decay, electronic noise and so on. The purpose of this is to `force' the system to output a result (a nonlinear function) that is an approximation to the input noise. This output is then treated as an iterated function which is subjected to a range of tests to check for potential cryptographic strength in terms of a positive Lyapunov exponent, maximum entropy, high cycle length, key diffusion characteristics etc. This approach provides the potential for generating an unlimited number of unique PRNG that can be used on a 1-to-1 basis. Typical applications include the encryption of data before it is uploaded onto the Cloud by a user that is provided with a personalised encryption algorithm rather than just a personal key using a `known algorithm' that may be subject to a `known algorithm attack' and/or is `open' to the very authorities who are promoting its use

Studying the evolution of AGB stars in the Gaia epoch

We present asymptotic giant branch (AGB) models of solar metallicity, to allow the interpretation of observations of Galactic AGB stars, whose distances should be soon available after the first release of the Gaia catalogue. We find an abrupt change in the AGB physical and chemical properties, occurring at the threshold mass to ignite hot bottom burning,i.e. $3.5M_{\odot}$. Stars with mass below $3.5 M_{\odot}$ reach the C-star stage and eject into the interstellar medium gas enriched in carbon , nitrogen and $^{17}O$. The higher mass counterparts evolve at large luminosities, between $3\times 10^4 L_{\odot}$ and $10^5 L_{\odot}$. The mass expelled from the massive AGB stars shows the imprinting of proton-capture nucleosynthesis, with considerable production of nitrogen and sodium and destruction of $^{12}C$ and $^{18}O$. The comparison with the most recent results from other research groups are discussed, to evaluate the robustness of the present findings. Finally, we compare the models with recent observations of galactic AGB stars, outlining the possibility offered by Gaia to shed new light on the evolution properties of this class of objects.Comment: 21 pages, 11 figure, 3 tables, accepted for publication in MNRAS (2016 July 11

New rhenopyrgid edrioasteroids (Echinodermata) and their implications for taxonomy, functional morphology, and paleoecology

Rhenopyrgids are rare, turreted edrioasterid edrioasteroids from the lower Paleozoic with a distinctive and apparently conservative morphology. However, new, well-preserved rhenopyrgid edrioasteroid material from Canada, along with a review of described taxa, has revealed broader structural diversity in the oral surface and enabled a re-evaluation of rhenopyrgid functional morphology and paleoecology. The floor plates in Rhenopyrgus viviani n. sp., R. coronaeformis Rievers, 1961 and, R. flos Klug et al., 2008 are well fused to each other and the interradial oral plate and lack obvious sutures, thereby forming a single compound interradial plate. This differs from other rhenopyrgids where sutures are more apparent. Such fused oral surface construction is only otherwise seen in some derived edrioblastoids and in the cyathocystids, suggesting homoplasy. Our analysis further suggests that the suboral constriction could contract but the flexible pyrgate zone could not. Thus, specimens apparently lacking a sub-oral constriction should not necessarily be placed in separate genera within the Rhenopyrgidae. It also supports rhenopyrgids as epifaunal mud-stickers with only the bulbous, textured, entire holdfasts (coriaceous sacs) anchored within the substrate rather than as burrow dwellers or encrusters. Rhenopyrgus viviani n. sp. is described from the Telychian (lower Silurian) Jupiter Formation of Anticosti Island, Québec, Canada and is differentiated by a high degree of morphological variability of pedunculate plates, broader oral plates, and narrower distal ambulacral zones. Specimens lacking or with obscured diagnostic plates from the Ordovician of Montagne Noire, France, and the Ordovician and Silurian of Girvan, Scotland are also described

Hot bottom burning and s-process nucleosynthesis in massive AGB stars at the beginning of the thermally-pulsing phase

We report the first spectroscopic identification of massive Galactic asymptotic giant branch (AGB) stars at the beginning of the thermal pulse (TP) phase. These stars are the most Li-rich massive AGBs found to date, super Li-rich AGBs with logE(Li)~3-4. The high Li overabundances are accompanied by weak or no s-process element (i.e. Rb and Zr) enhancements. A comparison of our observations with the most recent hot bottom burning (HBB) and s-process nucleosynthesis models confirms that HBB is strongly activated during the first TPs but the 22Ne neutron source needs many more TP and third dredge-up episodes to produce enough Rb at the stellar surface. We also show that the short-lived element Tc, usually used as an indicator of AGB genuineness, is not detected in massive AGBs which is in agreement with the theoretical predictions when the 22Ne neutron source dominates the s-process nucleosynthesis.Comment: Accepted for publication in Astronomy & Astrophysics Letters (7 pages, 5 figures and 1 table); final version (language corrected

Herramientas hidrogeoquímicas aplicadas a la evaluación del acuífero de Trenque Lauquen, provincia de Buenos Aires, Argentina

La ciudad de Trenque Lauquen en la provincia de Buenos Aires, Argentina se abastece exclusivamente del recurso h&iacute;drico subterr&aacute;neo. El objetivo del trabajo es analizar la evoluci&oacute;n temporal en la calidad fisicoqu&iacute;mica del agua, teniendo en cuenta las caracter&iacute;sticas hidrogeol&oacute;gicas y los procesos con la matriz s&oacute;lida. La metodolog&iacute;a consisti&oacute; en la valoraci&oacute;n y s&iacute;ntesis de la informaci&oacute;n geol&oacute;gica, geof&iacute;sica, hidrogeol&oacute;gica e hidroqu&iacute;mica y la modelaci&oacute;n de procesos hidrogeoqu&iacute;micos. El agua del acu&iacute;fero incrementa su salinidad con la profundidad de explotaci&oacute;n y evoluciona hacia una disoluci&oacute;n de yeso y precipitaci&oacute;n de calcita, con el consiguiente incremento del contenido de sulfatos y de dureza. Se consideran apropiadas las medidas de gesti&oacute;n en los &uacute;ltimos a&ntilde;os, que condujeron a realizar perforaciones m&aacute;s someras y con menor caudal de extracci&oacute;n, lo que ha permitido que la tendencia creciente a la salinizaci&oacute;n haya disminuido su tasa de evoluci&oacute;n, mejorando la calidad del agua subterr&aacute;nea.The city of Trenque Lauquen in the Buenos Aires Province, Argentina, gets water supply ex-clusively from groundwater resources. The goal of this study is to analyze time trends related to water quality, taking into account hydrogeological characteristics and processes with the solid matrix. The methodology consisted in the assessment and summary of geological, geophysical, hydrogeological and hydrochemical in-formation, and hydrogeochemical modelling. Groundwater salinity increases with the depth of exploitation and evolves into a gypsum dissolution and calcite precipitation, increasing sulphate content and hardness. Water management measures in recent years, based on shallow wells and lower extraction volumes became appropriate since the rate of salinization has decreased improving groundwater quality

Interventions promoting healthy eating as a tool for reducing social inequalities in diet in low- and middle-income countries: a systematic review.

Diet is a major risk factor for non-communicable diseases (NCDs) and is also strongly patterned by socioeconomic factors. Whether interventions promoting healthy eating reduce social inequalities in diet in low- and middle-income countries (LMICs) remains uncertain. This paper aims to summarize current evidence on interventions promoting healthy eating in LMICs, and to establish whether they reduce social inequalities in diet. Systematic review of cross-sectional or quasi-experimental studies (pre- and post-assessment of interventions) in Pubmed, Scielo and Google Scholar databases, including adults in LMICs, assessing at least one outcome of healthy eating and showing results stratified by socioeconomic status. Seven intervention studies including healthy eating promotion, conducted in seven LMICs (Brazil, Chile, Colombia, Iran, Panama, Trinidad and Tobago, and Tunisia), met our inclusion criteria. To promote healthy eating, all interventions used nutrition education and three of them combined nutrition education with improved acces to foods or social support. Interventions targeted mostly women and varied widely regarding communication tools and duration of the nutrition education sessions. Most interventions used printed material, media use or face-to-face training and lasted from 6 weeks to 5 years. Four interventions targeted disadvantaged populations, and three targeted the entire population. In three out of four interventions targeting disadvantaged populations, healthy eating outcomes were improved suggesting they were likely to reduce social inequalities in diet. All interventions directed to the entire population showed improved healthy eating outcomes in all social strata, and were considered as having no impact on social inequalities in diet. In LMICs, agentic interventions promoting healthy eating reduced social inequalities in diet when specifically targeting disadvantaged populations. Further research should assess the impact on social inequalities in diet of a combination of agentic and structural approaches in interventions promoting healthy eating