A general interior anisotropic solution for a BTZ vacuum in the context of the Minimal Geometric Deformation decoupling approach

In this work we implement the Minimal Geometric Deformation decoupling method to obtain general static interior solutions for a BTZ vacuum from the most general isotropic solution in $2+1$ dimensions including the cosmological constant $\Lambda$. We obtain that the general solution can be generated only by the energy density of the original isotropic sector, so that this quantity plays the role of a generating function. Although as a particular example we study the static star with constant density, the method here developed can be easily applied to more complex situations described by other energy density profiles.Comment: Accepted in EPJC. References correcte

Putative morphometric evidence of the presence of Acipenser naccarii Bonaparte, 1836 in Iberian rivers, or why ontogenetic allometry needs adequate treatment

He ampliado mi análisis inicial (Rincón, 2000) de los datos publicados sobre la morfometría de esturiones procedentes de aguas de la península Ibérica y de una piscifactoría, presentados como prueba del carácter nativo tanto de Acipenser naccarii Bonaparte, 1836 como de Acipenser sturio L., 1758 en la cuenca del Guadalquivir (Garrido-Ramos et al., 1997), aplicando las mismas técnicas uni- y multivariantes de ajuste de alometrías a una base de datos ampliada con un mayor número de ejemplares de A. naccarii. Como ya ocurrió, la representación gráfica de las diversas medidas cefálicas frente a la longitud total (todas transformadas a logaritmos) y de los componentes principales extraídos por ACP, realizados usando tanto la matriz de covarianza como la de correlación, no ofrecieron indicación alguna de la existencia de dos grupos morfológicamente distintos dentro de los esturiones capturados en aguas de la Península. Además, el relativamente débil (en cuanto a proporción de la varianza total que asumía) gradiente en la anchura del morro que separaba al único ejemplar de piscifactoría de los esturiones salvajes que hallé (Rincón, 2000), fue identificado de nuevo, ahora evidente y nítido, por todas las técnicas anteriores. Finalmente, un AFD mostró que tal diferencia permitía una casi perfecta, altamente significativa, distinción entre los especímenes de piscifactoría y los salvajes, mientras que no hubo gradiente morfométrico estadísticamente significativo que separase los supuestos dos grupos de esturiones salvajes ibéricos. El examen en la base de datos ampliada de las dos variables compuestas que Garrido-Ramos et al. (1997) usaron para distinguir tales dos grupos, confirmó que ambas se hallan gravemente influidas por la alometría ontogenética, llevando, por tanto, a la asignación de los ejemplares grandes o pequeños a grupos distintos. Concluyo, pues, que no hay evidencia morfológica alguna que apoye el supuesto carácter de especie autóctona de A. naccarii en la península Ibérica.I have extended my initial analyses (Rincón, 2000) of a published morphometric data set of sturgeons caught in Iberian rivers and from a fish farm, claimed to prove the native status of both Acipenser naccarii Bonaparte, 1836 and Acipenser sturio L., 1758 in the Guadalquivir basin (Garrido- Ramos et al., 1997), by applying the same uni- and multivariate techniques for allometric adjustment to a database expanded with further A. naccarii specimens. As previously, neither log-log scatterplots of head measurement vs. total length, nor graphical representation of the scores of individual specimens on the principal components (PC) extracted by PCAs performed on the covariance and correlation matrix, respectively, offered any suggestion of the existence of two morphologically dissimilar groups within wild Iberian sturgeons. In addition, the relatively weak (in terms of total variance accounted for) gradient in snout width that separated the one farmed Adriatic sturgeon from the wild fish found in my previous work (Rincón, 2000) was again detected, now clear and distinct, by all those techniques. Furthermore, a DFA showed that such dissimilarity produced almost perfect, highly statistically significant discrimination between farmed and wild fish, while there was no significant gradient separating the two supposed groups of wild Iberian sturgeons. Examination of the two composite variables that Garrido-Ramos et al. (1997) used to separate those groups in the extended database confirmed that they were negatively affected by ontogenetic allometry, therefore leading to the ascription of large and small specimens to different groups. I conclude that there is no morphological evidence to support the claimed autocthonous status of A. naccarii in the Iberian Peninsula.Instituto Español de Oceanografí

Cómo determinar los Parámetros de la Ecuación General de una Cuádrica a través de la Visualización

Las ecuaciones generales de las cuádricas en su forma general presentan un grado de dificultad al momento de determinar a qué tipo de cuádrica pertenece. En este sentido, la visualización juega un papel importante en la determinación y relación de la ecuación con su respectiva gráfica, dado que, al realizar una manipulación algebraica sobre la ecuación canónica de la superficie para transformarla a su forma general, se puede determinar por medio de la simple inspección de la ecuación general, no solamente a qué tipo de cuádrica pertenece, sino también se pueden determinar sus parámetros principale

Latino Migration within New York State: Motivations and Settlement Experience

This study focuses on understanding why and how Latinos decide to migrate within New York State, specifically in Albany. The authors examine the reasons that push Latinos to migrate internally hoping to find alternative explanations from those provided by neoclassical economics approaches which argue that migration decision-making processes are based on rational cost-benefit calculations (Massey et al. 1997). The authors hope these explanations contribute to grounded policy and program recommendations seeking to improve Latino life in the Albany area and in New York State. While economic opportunity (job opportunities/professional development) is still the leading reason that pulls Latinos from different places in New York State toward Albany, other reasons, such as changing the pace of their lives to start a family, seeking a more affordable environment, and reconnecting with friends and family, are also relevant

Transcriptional Response to Acute Thermal Exposure in Juvenile Chinook Salmon Determined by RNAseq.

Thermal exposure is a serious and growing challenge facing fish species worldwide. Chinook salmon (Oncorhynchus tshawytscha) living in the southern portion of their native range are particularly likely to encounter warmer water due to a confluence of factors. River alterations have increased the likelihood that juveniles will be exposed to warm water temperatures during their freshwater life stage, which can negatively impact survival, growth, and development and pose a threat to dwindling salmon populations. To better understand how acute thermal exposure affects the biology of salmon, we performed a transcriptional analysis of gill tissue from Chinook salmon juveniles reared at 12° and exposed acutely to water temperatures ranging from ideal to potentially lethal (12° to 25°). Reverse-transcribed RNA libraries were sequenced on the Illumina HiSeq2000 platform and a de novo reference transcriptome was created. Differentially expressed transcripts were annotated using Blast2GO and relevant gene clusters were identified. In addition to a high degree of downregulation of a wide range of genes, we found upregulation of genes involved in protein folding/rescue, protein degradation, cell death, oxidative stress, metabolism, inflammation/immunity, transcription/translation, ion transport, cell cycle/growth, cell signaling, cellular trafficking, and structure/cytoskeleton. These results demonstrate the complex multi-modal cellular response to thermal stress in juvenile salmon

Convergence to equilibrium for the discrete coagulation-fragmentation equations with detailed balance

Under the condition of detailed balance and some additional restrictions on the size of the coefficients, we identify the equilibrium distribution to which solutions of the discrete coagulation-fragmentation system of equations converge for large times, thus showing that there is a critical mass which marks a change in the behavior of the solutions. This was previously known only for particular cases as the generalized Becker-D\"oring equations. Our proof is based on an inequality between the entropy and the entropy production which also gives some information on the rate of convergence to equilibrium for solutions under the critical mass.Comment: 28 page

Unveiling Interfacial Li-Ion Dynamics in Li7La3Zr2O12/PEO(LiTFSI) Composite Polymer-Ceramic Solid Electrolytes for All-Solid-State Lithium Batteries

Unlocking the full potential of solid-state electrolytes (SSEs) is key to enabling safer and more-energy dense technologies than today’s Li-ion batteries. In particular, composite materials comprising a conductive, flexible polymer matrix embedding ceramic filler particles are emerging as a good strategy to provide the combination of conductivity and mechanical and chemical stability demanded from SSEs. However, the electrochemical activity of these materials strongly depends on their polymer/ceramic interfacial Li-ion dynamics at the molecular scale, whose fundamental understanding remains elusive. While this interface has been explored for nonconductive ceramic fillers, atomistic modeling of interfaces involving a potentially more promising conductive ceramic filler is still lacking. We address this shortfall by employing molecular dynamics and enhanced Monte Carlo techniques to gain unprecedented insights into the interfacial Li-ion dynamics in a composite polymer-ceramic electrolyte, which integrates polyethylene oxide plus LiN(CF3SO2)2 lithium imide salt (LiTFSI), and Li-ion conductive cubic Li7La3Zr2O12 (LLZO) inclusions. Our simulations automatically produce the interfacial Li-ion distribution assumed in space-charge models and, for the first time, a long-range impact of the garnet surface on the Li-ion diffusivity is unveiled. Based on our calculations and experimental measurements of tensile strength and ionic conductivity, we are able to explain a previously reported drop in conductivity at a critical filler fraction well below the theoretical percolation threshold. Our results pave the way for the computational modeling of other conductive filler/polymer combinations and the rational design of composite SSEs.-Juan de la Cierva grant IJC2018-037214-I, -PID2019-106519RB-I00, as -HPC-Europa3 grant HPC17ERWTO -AI in BCAM, EXP. 2019/004

Transition between SU(4) and SU(2) Kondo effect

Motivated by experiments in nanoscopic systems, we study a generalized Anderson, which consists of two spin degenerate doublets hybridized to a singlet by promotion of an electron to two conduction bands, as a function of the energy separation $\delta$ between both doublets. For $\delta$=0 or very large, the model is equivalent to a one-level SU(N) Anderson model, with N=4 and 2 respectively. We study the evolution of the spectral density for both doublets ($\rho_{1 \sigma}(\omega)$ and $\rho_{2 \sigma}(\omega)$) and their width in the Kondo limit as $\delta$ is varied, using the non-crossing approximation (NCA). As $\delta$ increases, the peak at the Fermi energy in the spectral density (Kondo peak) splits and the density of the doublet of higher energy $\rho_{2 \sigma}(\omega)$ shifts above the Ferrmi energy. The Kondo temperature $T_K$ (determined by the half width at half maximum of the Kondo peak in density of the doublet of lower energy $\rho_{1 \sigma}(\omega)$) decreases dramatically. The variation of $T_K$ with $\delta$ is reproduced by a simple variational calculation.Comment: 8 pages, 4 figures. Presented at the conference "Frontiers of Condensed Matter Physics", December 201