Memory effect in triglycine sulfate induced by a transverse electric field: specific heat measurement

The influence of a transverse electric field in the specific heat of triglycine sulphate (TGS) has been studied. The specific heat of TGS has been measured heating the sample from ferroelectric to paraelectric phase after prolonged transverse electric field (i.e. perpendicular to the ferroelectric axis). It is shown that the specific heat of TGS can remember the temperature $T_s$ at which the transverse field was previously applied.Comment: ReVTeX4 Twocolumn 4 pages, 4 figure

Managerial overconfidence and the buyback anomaly

While positive, long-run abnormal returns following share repurchaseannouncements are substantially lower when CEOs are overconfident. This effect is particularly strong for (i) difficult to value firms, such as small, young, non-dividend paying, distressed, and having negative earnings firms, (ii) firms with poor past stock return performance and high book-to-market ratio, indicators of possible overreaction to bad news, and (iii) financially constrained firms. Overall, these results are consistent with the mispricing hypothesis as a motive for repurchases and as an explanation for the buyback anomaly. Additionally, irrespective of the CEO’s level of confidence, abnormal returns are considerably larger for financially constrained firms, implying their managers require larger undervaluation due to the higher cost of capital

Sexual conflict and the evolution of monandry: the case of the damselfly Ischnura hastata (Odonata: Coenagrionidae) in the Galápagos Islands

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG1. Sexual selection favours the evolution and maintenance of polygamy, which is the dominant reproductive strategy in insects. Monogamy can evolve in very short-lived species due to time constraints. Here we study adult activity and mating behaviour of a population of the damselfly Ischnura hastata, a species rarely seen mating, and which has been suggested to be monandric, in wetlands of Isabela Island, Galápagos. 2. By means of mark-recapture methods we estimated that the daily survival rate was low, ranging from 0.385 to 0.876, yielding average life expectancies of mature individuals of only 1.2-3.2 days. Adults showed very low activity before 7:00, indicating that mating does not occur early. The number of male-female interactions and mating attempts was extremely low, with only 44 copulations recorded on over 230 h of observations. 3. Copulations were brief, with a mean duration of 11 minutes (but only two observed from the start). Males showed clear preference to attempt to grasp in tandem females of intermediate age (in 94.3% of cases), rather than young (31.3%) or mature females (24.0%). Males were very persistent once a tandem was achieved, retaining females for up to 139 min, but most females resisted and did not copulate. 4. We conclude that females of I. hastata show a very short time window to mate, exactly when they change colour from juvenile to mature, and live only enough to mate once. Short lifespan has selected for female monandry in I. hastata, creating an intense sexual conflict over mating rates.Ministerio de Economía y Competitividad | Ref. CGL2014-53140-PAgencia Estatal de Investigación | Ref. PGC2018-096656-B-I0

Good practice in mental health care for socially marginalised groups in Europe: a qualitative study of expert views in 14 countries

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The importance of permeability in granular filter design and control

Granular filters are required to perform two basic functions in embankment dams: (a) prevent the migration of base soil particles, and (b) allow drainage of seepage water. Traditionally, retention function (a) has been evaluated using Particle Size Distribution (PSD) and drainage function (b) using Permeability (kf), but usually permeability have been also correlated with PSD, so the permeability criterion have been expressed in terms of D15b of the base soil and D15f of the granular filter. Only few authors have used filter permeability for the assessment of retention function and there is no general agreement with them, but permeability should be a very important variable because it takes into account not only the whole PSD of the filter, (instead of just several representative diameters), but also other important characteristic such as compaction, porosity, density and particle shape. Based on a literature review and research experience at the University of Granada, this paper analyses the importance of filter permeability in the design and control of granular filters in embankment dams, even with dispersive base soils

A spin chain model with non-Hermitian interaction: the Ising quantum spin chain in an imaginary field

We investigate a lattice version of the Yang-Lee model which is characterized by a non-Hermitian quantum spin chain Hamiltonian. We propose a new way to implement PT-symmetry on the lattice, which serves to guarantee the reality of the spectrum in certain regions of values of the coupling constants. In that region of unbroken PT-symmetry we construct a Dyson map, a metric operator and find the Hermitian counterpart of the Hamiltonian for small values of the number of sites, both exactly and perturbatively. Besides the standard perturbation theory about the Hermitian part of the Hamiltonian, we also carry out an expansion in the second coupling constant of the model. Our constructions turns out to be unique with the sole assumption that the Dyson map is Hermitian. Finally we compute the magnetization of the chain in the z and x direction

Caracterización cromática de los vinos elaborados en la comarca española de la "Alpujarra-Contraviesa"

The chromatic characteristics of 69 samples oftraditional wines (no definite enological technique) made from a mixture of varieties of existing grapes (more than 98% were white varieties) in the Granadinian region of Alpujarra-Contraviesa (South of Spain) were studied as a method of typification and determination of their quality. The results after calculating the levels of Anthocyanins, Polyphenols, the CIE (1961) chromatic parameters, the Glories indices (1984) and the CIELAB space (1976)} indicate that the wines studied carne from musts which had spent very little time in contact with the solid matter of the grape. The very wide dispersion margins were consistent with their home-made character and, according to the majority of colour indices, they are c10ser to rose wines.En el presente trabajo, se han estudiado las características cromáticas de 69 muestras de vinos elaborados de forma artesanal (sin técnica enológica definida) y por mezcla de las variedades de uva existentes (más del 98% de variedades blancas) en la región granadina de la Alpujarra-Contraviesa (Sur de España). Los valores en Antocianos y Polifenoles, así como los parámetros cromáticos de la CIE (1961), los índices de Glories (1984) y el espacio CIELAB (1976) indican que los vinos estudiados proceden de mostos que han estado muy poco tiempo en contacto con las materias sólidas de la uva, con unos márgenes de dispersión muy amplios en concordancia con su carácter artesanal y más próximos a vinos rosados que a "claretes"

Comparison of the design and methodology of Phase 3 clinical trials of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and dolutegravir-based dual therapy (DTG) in HIV: a systematic review of the literature

Introduction: Current recommended antiretroviral regimens include a combination of two (dual; DT) or three (triple; TT) antiretroviral drugs. This study aims to determine whether the quality of evidence from clinical trials of dolutegravir (dolutegravir/lamivudine [DTG/3TC] or dolutegravir/rilpivirine [DTG/RPV]) is methodologically comparable to that of clinical trials conducted with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). Areas covered: A systematic review of the medical literature was carried out in PubMed without date or language restrictions, following the PRISMA guidelines. All aspects of the methodological design of phase 3 randomized clinical trials (RCTs) of DT and TT, evaluated by the European Medicines Agency (registration trials), were reviewed. The quality of clinical trials was assessed using the Jadad scale. Expert opinion: The search identified 5, 3 and 2 phase 3 RCTs with BIC/FTC/TAF, DTG/3TC and DTG/RPV, respectively, that met the inclusion criteria. The designs would not be comparable due to differences in pre-randomization losses, blinding, patient recruitment, as well as differences in methodological quality, with the average score of the RCTs conducted with BIC/FTC/TAF, DTG/3TC and DTG/RPV being 4.2 (high quality), 3.0 (medium quality) and 3.0 (medium quality), respectively. Due to methodological differences between the BIC/FTC/TAF, DTG/3TC and DTG/RPV RCTs, the results of these are not comparable