The Ciao clp(FD) library. A modular CLP extension for Prolog

We present a new free library for Constraint Logic Programming over Finite Domains, included with the Ciao Prolog system. The library is entirely written in Prolog, leveraging on Ciao's module system and code transformation capabilities in order to achieve a highly modular design without compromising performance. We describe the interface, implementation, and design rationale of each modular component. The library meets several design goals: a high level of modularity, allowing the individual components to be replaced by different versions; highefficiency, being competitive with other TT> implementations; a glass-box approach, so the user can specify new constraints at different levels; and a Prolog implementation, in order to ease the integration with Ciao's code analysis components. The core is built upon two small libraries which implement integer ranges and closures. On top of that, a finite domain variable datatype is defined, taking care of constraint reexecution depending on range changes. These three libraries form what we call the TT> kernel of the library. This TT> kernel is used in turn to implement several higher-level finite domain constraints, specified using indexicals. Together with a labeling module this layer forms what we name the TT> solver. A final level integrates the CLP (J7©) paradigm with our TT> solver. This is achieved using attributed variables and a compiler from the CLP (J7©) language to the set of constraints provided by the solver. It should be noted that the user of the library is encouraged to work in any of those levels as seen convenient: from writing a new range module to enriching the set of TT> constraints by writing new indexicals

Deciphering the molecular mechanism underpinning phage arbitrium communication systems

Bacillus phages use a communication system, termed “arbitrium,” to coordinate lysis-lysogeny decisions. Arbitrium communication is mediated by the production and secretion of a hexapeptide (AimP) during lytic cycle. Once internalized, AimP reduces the expression of the negative regulator of lysogeny, AimX, by binding to the transcription factor, AimR, promoting lysogeny. We have elucidated the crystal structures of AimR from the Bacillus subtilis SPbeta phage in its apo form, bound to its DNA operator and in complex with AimP. AimR presents intrinsic plasticity, sharing structural features with the RRNPP quorum-sensing family. Remarkably, AimR binds to an unusual operator with a long spacer that interacts nonspecifically with the receptor TPR domain, while the HTH domain canonically recognizes two inverted repeats. AimP stabilizes a compact conformation of AimR that approximates the DNA-recognition helices, preventing AimR binding to the aimX promoter region. Our results establish the molecular basis of the arbitrium communication system

Estudio longitudinal sobre redes sociales como método didáctico

This article gathers the perceptions of students on social networks, as a didactic method, with the aim of searching and designing didactic strategies to adapt the contents and methodology to the new technological context. The parti- cipants were university students of Early Childhood and Pri- mary Education in 2013-2014 and 2016-2017. A longitudinal study was conducted with a descriptive, non-experimental methodology and the semi-structured questionnaire used was validated through factorial and cluster analyses. The students from both degrees showed a polarization and dis- persion of opinions about social networks, which could be related to a more critical attitude toward their advantages and disadvantages.Este artículo recoge las percepciones de los estudiantes sobre las redes sociales como método didáctico, con el propósito de investigar y diseñar estrategias didácticas para adaptar los contenidos y la metodología al nuevo contexto tecnológico. Los participantes fueron estudiantes universitarios del pro- grama de Educación primaria y de la temprana infancia de los periodos 2013-2014 y 2016-2017. Se hizo un estudio lon- gitudinal con una metodología no-experimental, descriptiva y se validó un cuestionario semi-estructurado a través de aná- lisis factorial y de grupos. Los estudiantes de ambos periodos mostraron una polarización y dispersión de opiniones sobre las redes sociales, lo que podría estar relacionado con una actitud más crítica con respecto a sus ventajas y desventajas

Organic geochemistry of the Villaviciosa estuary record since 1400 AD (North of Spain)

We have reconstructed the palaeoenvironmental conditions in the Villaviciosa estuary during the last 600 yrs, from the biomarker content (alkanes and alkanoic acids) of the sediment. The amino acid racemization method in ostracodes allowed determining that the sedimentation in the Selorio bay started in 1400 AD. Organic matter was well preserved, although certain microbial activity was interpreted. Three periods were established from the alkane content: 1.- Between 1400 and 1580 AD terrestrial input was dominant; 2.- Between 1580 and 1720 AD there was a major influence of aquatic macrophytes, coinciding with the Little Ice Age, 3.- Between 1720 and 2015 AD there were alternating periods during which land plants or aquatic macrophytes predominated, probably linked to anthropogenic activitiesSe han reconstruido las condiciones paleoambientales de la zona de la ría de Villaviciosa de los últimos 600 años, a partir de los biomarcadores (alcanos y ácidos alcanoicos) presentes en el sedimento. El método de racemización de aminoácidos en ostrácodos ha permitido determinar el inicio de la sedimentación en la ensenada de Selorio, en la ría de Villaviciosa, que comenzó en 1400. La preservación de la materia orgánica es buena, aunque se observa una actividad microbiana importante. A partir de los alcanos se han establecido tres episodios: 1.- Entre 1400 y 1580 predominó el aporte de vegetación terrestre, 2.- Entre 1580 y 1720 hubo una mayor abundancia de macrofitas acuáticas, coincidiendo con la Pequeña Edad del Hielo, 3.- Entre 1720 y 2015, hubo una alternancia de aportes terrestres y de macrofitas acuáticas, posiblemente ligados a la acción antrópic

Evolución paleoambiental del Norte de España durante los últimos 2500 años a partir del estudio de biomarcadores de la Turbera de Roñanzas (Asturias)

Evolución paleoambiental del Norte de España durante los últimos 3000 años a partir del estudio de biomarcadores de la Turbera de Roñanzas (Asturias

Estimating the Relationship between Reading in Primary Education, Educational Attainment and Social Welfare. The Case of Extremadura (Spain)

The purpose of this paper is to analyse the relationship between the Social Welfare Index and the reading habits of primary school students in Extremadura (Spain). A study has been performed which consists of two parts. First, we conducted 4,288 surveys on reading habits in 87 municipalities. Second, we calculated the social welfare index. The statistical analysis refl ects two conclusions: firstly, educational and socio-economic policies have resulted in equal opportunities that allow for similar social possibilities throughout the territory; secondly, Educational Attainment of parents is the most decisive factor in obtaining the best results in terms of students' reading habits

Formulation and optimization of emulsions based on bitter fennel essential oil and EO/BO block copolymer surfactant

The influence of EO/BO block copolymer surfactant concentration in the range (1–5% (m/m)) and emulsification time on the emulsion stability and droplet size distribution of bitter fennel essential oil-in-water emulsions has been studied. Essential oils are promising material to be used for emulsion formulation with applications in cosmetics, food industry and agrochemicals. In the latter field these emulsions may be used as matrices for pesticides, where essential oils play the role of an eco-friendly solvent. A two-factor central composite design was conducted in order to optimize the emulsion formulation and processing. Emulsion stability has been studied as function of ageing time, by multiple light scattering (Turbiscan Lab-expert, Formulaction) and laser diffraction (Mastersizer X, Malvern). The surface response methodology allowed us to obtain a formulation comprising minimum droplet size and maximum stability by using a single step rotor/stator homogenization process. Creaming turned out to be the main destabilization mechanism. In order to improve emulsion stability the influence of high pressure homogenization (M110P, Microfluidics, MA, USA) and addition of a weighting agent (rosin gum) was studied. Although lower droplet sizes were obtained in both cases (D3,2 were in the range 0.30–0.35 μm), emulsions were more unstable maybe due to Ostwald ripening phenomena.(Project CTQ2015-70700-P) from theSpanish Ministerio de Economía y CompetitividadEuropean Commission (FEDER Programme)Bordas Chinchurreta and KA

Sperm handling in aquatic animals for artificial reproduction

Artificial reproduction involves collection and handling of gametes in a way that secures their quality and maximizes the fertilization outcome. In addition to initial sperm quality, numerous steps can affect the final result of fertilization, from the sperm collection process until gamete mixing (or co-incubation) when the spermatozoon enters or fuses with the oocyte. In this review, we summarize the whole process of sperm handling, from collection until fertilization for fish, penaeid shrimp, bivalve mollusks and marine mammals. To obtain sperm from captive animals, techniques vary widely across taxa, and include stripping by abdominal massage or testis surgical removal in fish, spermatophore collection in penaeid shrimps, gonadal scarification or temperature shock in bivalve mollusks, and voluntary collection via positive reinforcement in mammals. In most cases, special care is needed to avoid contamination by mucus, seawater, urine, or feces that can either activate sperm motility and/or decrease its quality. We also review techniques and extender solutions used for refrigerated storage of sperm across the aforementioned taxa. Finally, we give an overview of the different protocols for in vivo and in vitro fertilization including activation of sperm motility and methods for gamete co-incubation. The present study provides valuable information regarding breeder management either for animal production or species conservation.Agência financiadora CRB-anim ANR-11-INBS-003 Reproseed (FP7-KBBE-2009-3) MICIU (Juan de la Cierva-Incorporacion) IJCI-2017-34200 project ReproFl - MAR2020 Program 16-02-01-FMP-59 Fundacao para a Ciencia e Tecnologia (FCT, Portugal) through project FCT UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio

The JCMT Nearby Galaxies Legacy Survey – XI. Environmental Variations in the Atomic and Molecular Gas Radial Profiles of Nearby Galaxies

We present an analysis of the radial profiles of a sample of 43 H I-flux selected spiral galaxies from the Nearby Galaxies Legacy Survey (NGLS) with resolved James Clerk Maxwell Telescope (JCMT) CO J = 3 − 2 and/or Very Large Array (VLA) H I maps. Comparing the Virgo and non-Virgo populations, we confirm that the H i discs are truncated in the Virgo sample, even for these relatively H i-rich galaxies. On the other hand, the H2 distribution is enhanced for the Virgo galaxies near their centres, resulting in higher H2 to H I ratios and steeper H2 and total gas radial profiles. This is likely due to the effects of moderate ram pressure stripping in the cluster environment, which would preferentially remove low-density gas in the outskirts while enhancing higher density gas near the centre. Combined with Hα star formation rate data, we find that the star formation efficiency (SFR/H2) is relatively constant with radius for both samples, but the Virgo galaxies have an ∼40 per cent lower star formation efficiency than the non-Virgo galaxies