Two restrictions in the theories that include G(t) and c(t) varying with time

Much work has been done taking into account the possibility that the gravitational {\it constant} $G$ may vary with cosmological time $t$ (or with the cosmological scale factor $a(t)$). In many of these works the speed of light $c$ is not addressed or is taken as constant (see for example the Dirac large number hypothesis, \cite{Dirac}). The same can be said of many works that assume the speed of light $c$ to vary with cosmological time $t$ or $a(t)$ (see for example \cite{ MaMo}). Again in many of these works the gravitational constant $G$ is not addressed or is taken as constant. We have two important remarks on these assumptions.Fullana Alfonso, MJ.; Alfonso-Faus, A. (2014). Two restrictions in the theories that include G(t) and c(t) varying with time. Astrophysics and Space Science. 350(2):781-783. doi:10.1007/s10509-014-1803-4S7817833502Belinchón, J.A., Alfonso-Faus, A.: A theory of time-varying constants. Int. J. Mod. Phys. D 10, 299 (2001). Preprint: arXiv:gr-qc/0404044Dirac, P.A.M.: The cosmological constants. Nature 139, 323 (1937)Magueijo, J., Moffat, J.W.: Comments on “Note on varying speed of light theories”. Gen. Relativ. Gravit. 40, 1797 (2008). Preprint: arXiv:0705.450

About Bianchi I with VSL

In this paper we study how to attack, through different techniques, a perfect fluid Bianchi I model with variable G,c and Lambda, but taking into account the effects of a $c$-variable into the curvature tensor. We study the model under the assumption,div(T)=0. These tactics are: Lie groups method (LM), imposing a particular symmetry, self-similarity (SS), matter collineations (MC) and kinematical self-similarity (KSS). We compare both tactics since they are quite similar (symmetry principles). We arrive to the conclusion that the LM is too restrictive and brings us to get only the flat FRW solution. The SS, MC and KSS approaches bring us to obtain all the quantities depending on \int c(t)dt. Therefore, in order to study their behavior we impose some physical restrictions like for example the condition q<0 (accelerating universe). In this way we find that $c$ is a growing time function and Lambda is a decreasing time function whose sing depends on the equation of state, w, while the exponents of the scale factor must satisfy the conditions $\sum_{i=1}^{3}\alpha_{i}=1$ and $\sum_{i=1}^{3}\alpha_{i}^{2}<1,$ $\forall\omega$, i.e. for all equation of state$,$ relaxing in this way the Kasner conditions. The behavior of $G$ depends on two parameters, the equation of state $\omega$ and $\epsilon,$ a parameter that controls the behavior of $c(t),$ therefore $G$ may be growing or decreasing.We also show that through the Lie method, there is no difference between to study the field equations under the assumption of a $c-$var affecting to the curvature tensor which the other one where it is not considered such effects.Nevertheless, it is essential to consider such effects in the cases studied under the SS, MC, and KSS hypotheses.Comment: 29 pages, Revtex4, Accepted for publication in Astrophysics & Space Scienc

Generalized Self-similar Scalar-Tensor Theories

We study through symmetry principles the form of the functions in the generalizated scalar-tensor theories under the self-similar hypothesis. The results obtained are absolutely general and valid for all the Bianchi models and the flat FRW one. We study the concrete example of the Kantowsky-Sach model finding some exact self-similar solutions.Comment: 21 pages. Typos corrected. References added, minor correction

Bianchi {VI}0_{0} in Scalar and Scalar-Tensor Cosmologies

We study several cosmological models with Bianchi \textrm{VI}$_{0}$ symmetries under the self-similar approach. In order to study how the \textquotedblleft constants\textquotedblright\ $G$ and $\Lambda$ may vary, we propose three scenarios where such constants are considered as time functions. The first model is a perfect fluid. We find that the behavior of $G$ and $\Lambda$ are related. If $G$ behaves as a growing time function then $\Lambda$ is a positive decreasing time function but if $G$ is decreasing then $\Lambda$ is negative. For this model we have found a new solution. The second model is a scalar field, where in a phenomenological way, we consider a modification of the Klein-Gordon equation in order to take into account the variation of $G$. Our third scenario is a scalar-tensor model. We find three solutions for this models where $G$ is growing, constant or decreasing and $\Lambda$ is a positive decreasing function or vanishes. We put special emphasis on calculating the curvature invariants in order to see if the solutions isotropize.Comment: Typos corrected. References added, minor corrections. arXiv admin note: text overlap with arXiv:0905.247

Bianchi II with time varying constants. Self-similar approach

We study a perfect fluid Bianchi II models with time varying constants under the self-similarity approach. In the first of the studied model, we consider that only vary $G$ and $\Lambda.$ The obtained solution is more general that the obtained one for the classical solution since it is valid for an equation of state $\omega\in(-1,\infty)$ while in the classical solution $\omega\in(-1/3,1) .$ Taking into account the current observations, we conclude that $G$ must be a growing time function while $\Lambda$ is a positive decreasing function. In the second of the studied models we consider a variable speed of light (VSL). We obtain a similar solution as in the first model arriving to the conclusions that $c$ must be a growing time function if $\Lambda$ is a positive decreasing function.Comment: 10 pages. RevTeX

Consenso sobre las actuaciones a seguir durante la edad fértil, el embarazo, el posparto y la lactancia en pacientes con psoriasis

Objetivo Desarrollar recomendaciones basadas en la mejor evidencia y experiencia sobre el manejo de pacientes con psoriasis durante la edad fértil, el embarazo, el posparto y la lactancia. Métodos Se siguió la metodología de grupos nominales y Delphi. Se seleccionó un grupo director de expertos (12 dermatólogos —de los cuales 2 fueron los coordinadores—, 1 reumatólogo, 2 ginecólogos). Se realizó una revisión sistemática de la literatura sobre fertilidad, embarazo, posparto y lactancia en pacientes con psoriasis. Con esta información los coordinadores generaron una serie de recomendaciones preliminares. Todo ello se presentó y discutió con el resto de expertos en una reunión de grupo nominal donde se definió el alcance, los usuarios, los apartados del documento, y donde se generaron las recomendaciones definitivas. El grado de acuerdo con las recomendaciones se votó siguiendo la metodología Delphi, que se extendió a 51 dermatólogos más, según una escala de 1 (total desacuerdo) a 10 (total acuerdo), definiéndose el acuerdo como una puntuación = 7 por al menos el 70% de los participantes. El nivel de evidencia y el grado de recomendación se clasificaron según el modelo del Center for Evidence Based Medicine de Oxford. El documento completo final fue aprobado por el panel de expertos. Resultados Se generaron 23 recomendaciones sobre el periodo pre-concepcional (fertilidad y anticoncepción), el embarazo (planificación, manejo farmacológico y seguimiento) y la lactancia (manejo y seguimiento). Todas las recomendaciones menos una alcanzaron el nivel de acuerdo definido. Conclusiones En los pacientes con psoriasis en edad fértil estas recomendaciones pueden mejorar el manejo, los resultados y el pronóstico. Objective To develop evidence- and experience-based recommendations for the management of psoriasis during preconception, pregnancy, postpartum, and breastfeeding. Methods The nominal group technique and the Delphi method were used. Fifteen experts (12 dermatologists, 2 of whom were appointed coordinators; 1 rheumatologist; and 2 gynecologists) were selected to form an expert panel. Following a systematic review of the literature on fertility, pregnancy, postpartum, and breastfeeding in women with psoriasis, the coordinators drew up a series of preliminary recommendations for discussion by the panel at a nominal group meeting. The experts defined the scope, sections, and intended users of the statement and prepared a final list of recommendations. Consensus was obtained using a Delphi process in which an additional 51 dermatologists rated their level of agreement with each recommendation on a scale of 1 (total disagreement) to 10 (total agreement). Consensus was defined by a score of 7 or higher assigned by at least 70% of participants. Level of evidence and strength of recommendation were reported using the Oxford Center for Evidence-Based Medicine categories. The final statement was approved by the expert panel. Results The resulting consensus statement includes 23 recommendations on preconception (fertility and contraception), pregnancy (planning, pharmacological management, and follow-up), and breastfeeding (management and follow-up). Consensus was achieved for all recommendations generated except one. Conclusions These recommendations for the better management of psoriasis in women of childbearing age could improve outcomes and prognosis

Association of a single nucleotide polymorphism combination pattern of the Klotho gene with non-cardiovascular death in patients with chronic kidney disease

Chronic kidney disease (CKD) is associated with an elevated risk of all-cause mortality, with cardiovascular death being extensively investigated. However, non-cardiovascular mortality represents the biggest percentage, showing an evident increase in recent years. Klotho is a gene highly expressed in the kidney, with a clear influence on lifespan. Low levels of Klotho have been linked to CKD progression and adverse outcomes. Single nucleotide polymorphisms (SNPs) of the Klotho gene have been associated with several diseases, but studies investigating the association of Klotho SNPs with noncardiovascular death in CKD populations are lacking. The main aim of this study was to assess whether 11 Klotho SNPs were associated with non-cardiovascular death in a subpopulation of the National Observatory of Atherosclerosis in Nephrology (NEFRONA) study (n ¼ 2185 CKD patients). After 48 months of follow-up, 62 cardiovascular deaths and 108 non-cardiovascular deaths were recorded. We identified a high non-cardiovascular death risk combination of SNPs corresponding to individuals carrying the most frequent allele (G) at rs562020, the rare allele (C) at rs2283368 and homozygotes for the rare allele (G) at rs2320762 (rs562020 GG/AG þ rs2283368 CC/CT þ rs2320762 GG). Among the patients with the three SNPs genotyped (n ¼ 1016), 75 (7.4%) showed this combination. Furthermore, 95 (9.3%) patients showed a low-risk combination carrying all the opposite genotypes (rs562020 AA þ rs2283368 TT þ rs2320762 GT/TT). All the other combinations [n ¼ 846 (83.3%)] were considered as normal risk. Using competing risk regression analysis, we confirmed that the proposed combinations are independently associated with a higher fhazard ratio [HR] 3.28 [confidence interval (CI) 1.51-7.12]g and lower [HR 6 × 10- (95% CI 3.3 × 10--1.1 × 10-)] risk of suffering a non-cardiovascular death in the CKD population of the NEFRONA cohort compared with patients with the normal-risk combination. Determination of three SNPs of the Klotho gene could help in the prediction of non-cardiovascular death in CKD

Association of candidate gene polymorphisms with chronic kidney disease : Results of a case-control analysis in the NEFRONA cohort

Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2,445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionization-time of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD

Exact solutions of a full causal bulk viscous FRW cosmological model with variable G and Lambda through factorization

We study the classical flat full causal bulk viscous FRW cosmological model with variable gravitational and cosmological constants through the factorization method. The method allows us to find some new exact parametric solutions. The assumptions made bring us to study two approaches. We find, in the studied cases, that the Universe ends in an accelerating era except in the case of a particular solution where the Universe could be noninflationary for all times. In both approaches the cosmological constant is a decreasing function of time, while the gravitational constant behaves as a growing or decreasing time function depending on the sign of Λ. By taking into account recent observations that indicate that Λ must be positive, we conclude that G increases with time except in the first solution where both “constants” tend asymptotically in the large time limit to a constant value. We also present a new factorization scheme which allows us to generate new solutions to a kind of variable coefficient nonlinear second order ODE.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Management of Psoriasis During Preconception, Pregnancy, Postpartum, and Breastfeeding: A Consensus Statement

Objective To develop evidence- and experience-based recommendations for the management of psoriasis during preconception, pregnancy, postpartum, and breastfeeding. Methods The nominal group technique and the Delphi method were used. Fifteen experts (12 dermatologists, 2 of whom were appointed coordinators; 1 rheumatologist; and 2 gynecologists) were selected to form an expert panel. Following a systematic review of the literature on fertility, pregnancy, postpartum, and breastfeeding in women with psoriasis, the coordinators drew up a series of preliminary recommendations for discussion by the panel at a nominal group meeting. The experts defined the scope, sections, and intended users of the statement and prepared a final list of recommendations. Consensus was obtained using a Delphi process in which an additional 51 dermatologists rated their level of agreement with each recommendation on a scale of 1 (total disagreement) to 10 (total agreement). Consensus was defined by a score of 7 or higher assigned by at least 70% of participants. Level of evidence and strength of recommendation were reported using the Oxford Center for Evidence-Based Medicine categories. The final statement was approved by the expert panel. Results The resulting consensus statement includes 23 recommendations on preconception (fertility and contraception), pregnancy (planning, pharmacological management, and follow-up), and breastfeeding (management and follow-up). Consensus was achieved for all recommendations generated except one. Conclusions These recommendations for the better management of psoriasis in women of childbearing age could improve outcomes and prognosis. Objetivo Desarrollar recomendaciones basadas en la mejor evidencia y experiencia sobre el manejo de pacientes con psoriasis durante la edad fértil, el embarazo, el posparto y la lactancia. Métodos Se siguió la metodología de grupos nominales y Delphi. Se seleccionó un grupo director de expertos (12 dermatólogos —de los cuales 2 fueron los coordinadores—, 1 reumatólogo, 2 ginecólogos). Se realizó una revisión sistemática de la literatura sobre fertilidad, embarazo, posparto y lactancia en pacientes con psoriasis. Con esta información los coordinadores generaron una serie de recomendaciones preliminares. Todo ello se presentó y discutió con el resto de expertos en una reunión de grupo nominal donde se definió el alcance, los usuarios, los apartados del documento, y donde se generaron las recomendaciones definitivas. El grado de acuerdo con las recomendaciones se votó siguiendo la metodología Delphi, que se extendió a 51 dermatólogos más, según una escala de 1 (total desacuerdo) a 10 (total acuerdo), definiéndose el acuerdo como una puntuación = 7 por al menos el 70% de los participantes. El nivel de evidencia y el grado de recomendación se clasificaron según el modelo del Center for Evidence Based Medicine de Oxford. El documento completo final fue aprobado por el panel de expertos. Resultados Se generaron 23 recomendaciones sobre el periodo pre-concepcional (fertilidad y anticoncepción), el embarazo (planificación, manejo farmacológico y seguimiento) y la lactancia (manejo y seguimiento). Todas las recomendaciones menos una alcanzaron el nivel de acuerdo definido. Conclusiones En los pacientes con psoriasis en edad fértil estas recomendaciones pueden mejorar el manejo, los resultados y el pronóstico