Special birational transformations of projective spaces

Extending some results of Crauder and Katz and Ein and Sheperd-Barron on special Cremona transformations, we study birational transformations of P^r onto a prima Fano manifold such that the base locus X in P^r is smooth, irreducible and reduced. The main results are a complete classification when X has either dimension 1 and 2 or codimension 2. Partial results are also obtained when X has dimension 3

Surfaces containing a family of plane curves not forming a fibration

We complete the classification of smooth surfaces swept out by a 1-dimensional family of plane curves that do not form a fibration. As a consequence, we characterize manifolds swept out by a 1-dimensional family of hypersurfaces that do not form a fibration.Comment: Author's post-print, final version published online in Collect. Mat

An explanatory model of sexual satisfaction in adults with a same-sex partner: An analysis based on gender differences

This study aimed to develop an explanatory model of sexual satisfaction in same-sex attracted individuals with a partner, based on personal and interpersonal variables. The participants were 410 men (mean age = 29.24, SD = 9.84) and 410 women (mean age = 29, SD = 8.57) who maintained a relationship with another person of the same sex. Internalized homophobia was considered as a personal variable, and as interpersonal variables, the dimensions of attachment (anxiety and avoidance), sexual functioning, dyadic adjustment, relationship satisfaction, the components of the Interpersonal Exchange Model of Sexual Satisfaction, the number of sexual costs and the number of sexual rewards were considered. The degree to which sexual satisfaction was related to these variables was examined separately, for both men and women, through multiple linear regression models within the framework of structural equation models. The results indicated that sexual satisfaction is associated in a negative sense with internalized homophobia, the number of sexual costs, anxiety, and avoidance, and in a positive sense with the remaining variables. Relational variables were more relevant in the explanation of sexual satisfaction. The clinical implications are discussed

An abridged Spanish version of Sexual Double Standard Scale: Factorial structure, reliability and validity evidence

Background/Objective Sexual double standard (SDS) has long been associated to several dimensions of sexual health. Therefore the assessment of SDS is relevant and requires self-reported measures with adequate psychometric properties. This study aims to adapt the Sexual Double Standard Scale (SDSS) into heterosexual Spanish population and examine its psychometric properties. Method: Using quota incidental sampling, we recruited a sample of 1, 206 individuals (50% women), distributed across three groups based on their age (18-34, 35-49 and 50 years old and older). Results: We performed both, Exploratory Factor Analysis and Confirmatory Factor Analysis. An abridged version was yielded, consisting of 16 items distributed into two factors (Acceptance for sexual freedom and Acceptance for sexual shyness). A second-order factor structure was also adequate, which facilitates the use of a global index for SDS. Reliability, based on internal consistency and temporal stability was good for the factors. Evidence of validity is also shown and reported. Conclusions: This adapted version of the SDSS is reliable and valid. The importance for its use to estimate the prevalence of both traditional and modern forms of this phenomenon is discussed. Antecedentes/Objetivo: El doble estándar sexual (DES) se ha asociado a distintas dimensiones de la salud sexual, por lo que su evaluación es relevante y requiere de instrumentos con ade- cuadas propiedades psicométricas. Se plantea la adaptación a población heterosexual espa ~ nola de la Sexual Double Standard Scale (SDSS) y examinar sus propiedades psicométricas. Método : Mediante un muestreo incidental por cuotas se obtuvo una muestra de 1.206 sujetos (50% mujeres), distribuidos en tres grupos en función de la edad (18-34 a ~ nos, 35-49 a ~ nos y 50 a ~ nos o más). Resultados : Mediante Análisis Factorial Exploratorio y Análisis Factorial Confirmatorio se consiguió una versión de 16 ítems distribuidos en dos factores (Aceptación de la libertad sexual y Aceptación del recato sexual), cuya combinación en un factor de segundo orden per- mite obtener un índice global de doble estándar sexual. La fiabilidad de consistencia interna y test-retest es óptima para los dos subfactores y sus medidas presentan adecuados índices de validez. Conclusiones : Esta versión adaptada de la SDSS es fiable y válida. Se discute su impor- tancia para detectar la prevalencia de DES tradicional y de expresiones más modernas de este fenómeno

A binding event converted into a folding event

AbstractWe have designed a chimeric protein by connecting a circular permutant of the α-spectrin SH3 domain to the proline-rich decapeptide APSYSPPPPP with a three-residue link. Our aim was to obtain a single-chain protein with a tertiary fold that would mimic the binding between SH3 domains and proline-rich peptides. A comparison of the circular-dichroism and fluorescence spectra of the purified chimera and the SH3 circular permutant showed that the proline-rich sequence occupies the putative SH3 binding site in a similar conformation and with comparable interactions to those found in complexes between SH3 and proline-rich peptides. Differential scanning calorimetry indicated that the interactions in the binding motif interface are highly cooperative with the rest of the structure and thus the protein unfolds in a two-state process. The chimera is more stable than the circular permutant SH3 by 6–8 kJ mol−1 at 25°C and the difference in their unfolding enthalpy is approximately 32 kJ mol−1, which coincides with the values found for the binding of proline-rich peptides to SH3 domains. This type of chimeric protein may be useful in designing SH3 peptide ligands with improved affinity and specificity

Updating the statistics reported for the EU-Spain purse seine fishing fleet in the Indian Ocean (period 1984-2019) and the effects of the COVID-19 pandemic on the port sampling activity in Victoria (Seychelles)

This document provides an update on the statistics reported for the Spanish purse seine fleet fisheries in the Indian Ocean for the period 1984 to 2019. Data include catch and effort statistics, as well as some fishery indicators by species and fishing mode. Information about the coverage of the sampling, together with maps and diagrams illustrating the spatial-temporal fishing patterns of this fleet are also provided

The spin and charge gaps of the half-filled N-leg Kondo ladders

In this work, we study N-leg Kondo ladders at half-filling through the density matrix renormalization group. We found non-zero spin and charge gaps for any finite number of legs and Kondo coupling $J>0$. We also show evidence of the existence of a quantum critical point in the two dimensional Kondo lattice model, in agreement with previous works. Based on the binding energy of two holes, we did not find evidence of superconductivity in the 2D Kondo lattice model close to half-filling.Comment: 4 pages, 1 table, 3 fig

A review on the development of visible light-responsive WO3-based photocatalysts for environmental applications

The use of semiconductor photocatalysis is a promising, green, and sustainable technology to address solar energy conversion and environmental remediation issues. Among photocatalytically active semiconductors, considerable attention has been given to the visible-light active tungsten oxide (WO3, Eg value ≈ 2.7–3.1 eV). This semiconductor has several advantages: strong absorption in the visible spectrum range, stability in acidic and oxidative conditions, low cost, and low toxicity. However, WO3 presents fast recombination of charge carriers’ and exhibits low photocatalytic activity for reduction reactions due to its conduction band potential (+0.5 V versus NHE). Many strategies have been applied to enhance photocatalytic activity and solar energy utilization of WO3 by modifying the energy band position and reducing the charge carrier recombination. In this review, several approaches, such as designing with exposed facets and specific morphologies, doping with transition metals and non-metals, deposition of noble metals, and heterojunction construction, are summarized. Moreover, the photocatalytic properties of the reviewed WO3-based photocatalysts are discussed based on their environmental applications such as degradation of organic pollutants, air purification, CO2 photoreduction, hydrogen production from water splitting and recently, simultaneous wastewater treatment and electric energy generation by photocatalytic fuel cells. Finally, the summary, future perspectives, and challenges of design novel WO3-based photocatalysts with high efficiency are pointed out to meet the urgent demands of highly efficient technologies that use visible or solar energy for environmental applications

Biodegradability of extractives in sapwood and heartwood from Scots pine by sapstain and white rot fungi

1 Division of Wood Science, Sub-department of Forestry, Wageningen Agricultural University, Wageningen, The Netherlands 2 Instituto de Recursos Naturales y Agrobiología (IRNA), Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, SpainThe fungal degradation of lipophilic extractives in sapwood and heartwood from Scots pine (Pinus sylvestris) was studied. In sapwood, the white rot fungi, Bjerkandera sp. and Funalia trogii, removed higher amounts of extractives than the sapstain strains, Ophiostoma ainoae and Ceratocystis allantospora. Triglycerides, long chain fatty acids, steryl esters and waxes in pine sapwood were almost completely degraded by all the fungi. Sterols and resin acids were also extensively degraded by the white rot strains; however, these components were not or only poorly removed by the sapstain fungi. The removal of total extractives by all the fungal strains was higher in sapwood as compared to heartwood. The highly concentrated extractive fraction in pine heartwood mainly consists of resin acids. As observed in sapwood, sapstain were also poorly effective in the degradation of the resin acids present in heartwood. The fungal degradation of heartwood extractives was not only limited by the degradative ability of the various test microorganisms, but also by the inhibitory effect exerted by the extractive fraction. The white rot fungus F. trogii was particularly inhibited on heartwood. Bjerkandera sp. showed a higher tolerance to toxic extractives and was the most efficient fungus in degrading extractive constituents in both Scots pine heartwood and sapwood. Therefore, Bjerkandera sp. strain BOS55 should be considered as a potential agent for pitch control in pulp and paper manufacture.This study has been carried out with financial support from the Commission of the European Communities, Agriculture and Fisheries (FAIR) contract no. CT 95–0560, “Wood extractives in pulp and paper manufacture: technical and environmental implications and biological removal”.Peer reviewe