Global Existence of Weak Solutions to the Compressible Primitive Equations of Atmospheric Dynamics with Degenerate Viscosities

We show the existence of global weak solutions to the three-dimensional compressible primitive equations of atmospheric dynamics with degenerate viscosities. In analogy with the case of the compressible Navier-Stokes equations, the weak solutions satisfy the basic energy inequality, the Bresh-Desjardins entropy inequality and the Mellet-Vasseur estimate. These estimates play an important role in establishing the compactness of the vertical velocity of the approximating solutions, and therefore are essential to recover the vertical velocity in the weak solutions

Model selection, estimation and forecasting in VAR models with short-run and long-run restrictions

We study the joint determination of the lag length, the dimension of the cointegrating space and the rank of the matrix of short-run parameters of a vector autoregressive (VAR) model using model selection criteria. We consider model selection criteria which have data-dependent penalties for a lack of parsimony, as well as the traditional ones. We suggest a new procedure which is a hybrid of traditional criteria with data-dependant penalties. In order to compute the fit of each model, we propose an iterative procedure to compute the maximum likelihood estimates of parameters of a VAR model with short-run and long-run restrictions. Our Monte Carlo simulations measure the improvements in forecasting accuracy that can arise from the joint determination of lag-length and rank, relative to the commonly used procedure of selecting the lag-length only and then testing for cointegration.Reduced rank models, model selection criteria, forecasting accuracy

Investigation of restricted baby Skyrme models

A restriction of the baby Skyrme model consisting of the quartic and potential terms only is investigated in detail for a wide range of potentials. Further, its properties are compared with those of the corresponding full baby Skyrme models. We find that topological (charge) as well as geometrical (nucleus/shell shape) features of baby skyrmions are captured already by the soliton solutions of the restricted model. Further, we find a coincidence between the compact or non-compact nature of solitons in the restricted model, on the one hand, and the existence or non-existence of multi-skyrmions in the full baby Skyrme model, on the other hand.Comment: latex, 18 pages, 2 figures; some typos correcte

Stabilized Schemes for the Hydrostatic Stokes Equations

Some new stable finite element (FE) schemes are presented for the hydrostatic Stokes system or primitive equations of the ocean. It is known that the stability of the mixed formulation ap- proximation for primitive equations requires the well-known Ladyzhenskaya–Babuˇska–Brezzi condi- tion related to the Stokes problem and an extra inf-sup condition relating the pressure and the vertical velocity. The main goal of this paper is to avoid this extra condition by adding a residual stabilizing term to the vertical momentum equation. Then, the stability for Stokes-stable FE combinations is extended to the primitive equations and some error estimates are provided using Taylor–Hood P2 –P1 or miniele- ment (P1 +bubble)–P1 FE approximations, showing the optimal convergence rate in the P2 –P1 case. These results are also extended to the anisotropic (nonhydrostatic) problem. On the other hand, by adding another residual term to the continuity equation, a better approximation of the vertical derivative of pressure is obtained. In this case, stability and error estimates including this better approximation are deduced, where optimal convergence rate is deduced in the (P 1 +bubble)–P1 case. Finally, some numerical experiments are presented supporting previous results

¿Consumen más drogas los adolescentes con déficit en habilidades sociales?

Durante la adolescencia es común que se manifiesten conductas de riesgo para la salud entre las que destaca el uso de drogas. El déficit en habilidades sociales es uno de los factores de riesgo señalado por los modelos teóricos sobre el inicio del consumo. El objetivo de este estudio es aportar datos empíricos sobre la relación entre las habilidades sociales y el consumo de sustancias psicoactivas en población adolescente española. Se pretende además examinar las diferencias en este factor de riesgo en función de la edad y el sexo. Participaron 1.688 estudiantes españoles de secundaria con edades comprendidas entre 13 y 17 años que informaron sobre sus hábitos de consumo y su competencia social. Los resultados indicaron una clara relación entre las habilidades sociales y el consumo de sustancias. La conducta antisocial está asociada al consumo de alcohol y cannabis. Los varones puntúan en mayor medida en conducta agresiva/ antisocial, orgullo/arrogancia y soledad/ansiedad social. Los resultados confirman la importancia de prevenir el consumo de sustancias de forma selectiva con adolescentes que presenten conductas sociales inadecuadasDuring adolescence risk behaviors for health are common, including drug use. A deficit in social skills is one of the risk factors identified by the theoretical models of initiation to consumption. The aim of this study is to provide empirical data on the relationship between social skills and the use of psychoactive substances in Spanish adolescents. It also aims to examine the differences in this risk factor in terms of age and sex. 1,688 high school Spanish students aged between 13 and 17 years reported their consumption habits and their social competence. The results indicated a clear relationship between social skills and substance use. Antisocial behavior is associated with alcohol and cannabis. Males scored more on aggressive/antisocial behavior, pride/arrogance and loneliness/social anxiety. The results confirm the importance of selectively preventing consumption of substances among adolescents with inappropriate social behavior

Topological phase transitions in the gauged BPS baby Skyrme model

We demonstrate that the gauged BPS baby Skyrme model with a double vacuum potential allows for phase transitions from a non-solitonic to a solitonic phase, where the latter corresponds to a ferromagnetic liquid. Such a transition can be generated by increasing the external pressure P or by turning on an external magnetic field H. As a consequence, the topological phase where gauged BPS baby skyrmions exist, is a higher density phase. For smaller densities, obtained for smaller values of P and H, a phase without solitons is reached. We find the critical line in the P,H parameter space. Furthermore, in the soliton phase, we find the equation of state for the baby skyrmion matter V = V (P,H) at zero temperature, where V is the “volume”, i.e., area of the solitonsThe authors acknowledge financial support from the Ministry of Education, Culture, and Sports, Spain (Grant No. FPA2011-22776), the Xunta de Galicia (Grant No. INCITE09.296.035PR and Conselleria de Educacion), the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042), and FEDER. Further, the authors acknowledge support from the Polish FOCUS grant (No. 42/F/AW/2014). CN thanks the Spanish Ministery of Education, Culture and Sports for financial support (grant FPU AP2010-5772)S

Barriers to the development of palliative care in Western Europe

The Eurobarometer Survey of the <i>EAPC Task Force on the Development of Palliative Care in Europe</i> is part of a programme of work to produce comprehensive information on the provision of palliative care across Europe. Aim: To identify barriers to the development of palliative care in Western Europe. Method: A qualitative survey was undertaken amongst boards of national associations, eliciting opinions on opportunities for, and barriers to, palliative care development. By July 2006, 44/52 (85%) European countries had responded to the survey; we report here on the results from 22/25 (88%) countries in Western Europe. Analysis: Data from the Eurobarometer survey were analysed thematically by geographical region and by the degree of development of palliative care in each country. Results: From the data contained within the Eurobarometer, we identified six significant barriers to the development of palliative care in Western Europe: (i) Lack of palliative care education and training programmes (ii) Lack of awareness and recognition of palliative care (iii) Limited availability of/knowledge about opioid analgesics (iv) Limited funding (v) Lack of coordination amongst services (vi) Uneven palliative care coverage. Conclusion: Findings from the EAPC Eurobarometer survey suggest that barriers to the development of palliative care in Western Europe may differ substantially from each other in both their scope and context and that some may be considered to be of greater significance than others. A number of common barriers to the development of the discipline do exist and much work still remains to be done in the identified areas. This paper provides a road map of which barriers need to be addressed

New Integrable Sectors in Skyrme and 4-dimensional CP^n Model

The application of a weak integrability concept to the Skyrme and $CP^n$ models in 4 dimensions is investigated. A new integrable subsystem of the Skyrme model, allowing also for non-holomorphic solutions, is derived. This procedure can be applied to the massive Skyrme model, as well. Moreover, an example of a family of chiral Lagrangians providing exact, finite energy Skyrme-like solitons with arbitrary value of the topological charge, is given. In the case of $CP^n$ models a tower of integrable subsystems is obtained. In particular, in (2+1) dimensions a one-to-one correspondence between the standard integrable submodel and the BPS sector is proved. Additionally, it is shown that weak integrable submodels allow also for non-BPS solutions. Geometric as well as algebraic interpretations of the integrability conditions are also given.Comment: 23 page

Evaluating quality of life in pediatric palliative care : a cross-sectional analysis of children's and parents' perspectives

Altres ajuts: acords transformatius de la UABThe patient's perspective is an essential component of understanding the individual experience of suffering in children with palliative needs, but it is a perspective that is often overlooked. The aim of this study was to compare the perception of quality of life (QoL) of children with life-limiting and life-threatening conditions expressed by the children themselves and their parents. Through a cross-sectional study, the responses of 44 parent-child dyads were obtained and the analysis was performed with the statistics based on Student's t distribution and non-parametric tests. Children value QoL more positively (mean = 6.95, SD = 1.85) than their parents (mean = 5.39, SD = 2.43). This difference exists even if we consider sociodemographic and disease variables. The presence of exacerbated symptoms is the situation in which both parents (mean = 3.70; SD = 1.95) and children (mean = 5.60; SD = 1.17) evaluate QoL more negatively. Conclusions: Children have a more optimistic view than their parents. When the child is the one who reports a lower QoL score than their parent, the child should be carefully monitored. The voice of the child and that of the family members can be collected to create a "family voice" and can be complementary. What is Known: • Children with life-limiting conditions experience multiple and changing symptoms that affect their QoL. • The child's perspective is often overlooked. What is New: • Children value QoL more positively than their parents do, even if we control for sociodemographic variables and the disease itself. • When the child is the one who reports a lower QoL score than their parent, the child should be carefully monitored