Time-dependent local Green's operator and its applications to manganites

An algorithm is presented to calculate the electronic local time-dependent Green's operator for manganites-related hamiltonians. This algorithm is proved to scale with the number of states $N$ in the Hilbert-space to the 1.55 power, is able of parallel implementation, and outperforms computationally the Exact Diagonalization (ED) method for clusters larger than 64 sites (using parallelization). This method together with the Monte Carlo (MC) technique is used to derive new results for the manganites phase diagram for the spatial dimension D=3 and half-filling on a 12x12x12 cluster (3456 orbitals). We obtain as a function of an insulating parameter, the sequence of ground states given by: ferromagnetic (FM), antiferromagnetic AF-type A, AF-type CE, dimer and AF-type G, which are in remarkable agreement with experimental results.Comment: 9 pages, 11 figure

Discusión sobre la distribución estratigráfica de "Pseudofurnishius murcianus" van den Boogaard (Conodonta) en la Península Ibérica, a partir de la sección de Calasparra (Murcia, España)

The biostratigraphy of Calasparra Section is well-estabished with an ammonoid biozonation and ranges from Lower to Upper Ladinian. The continuous presence of Pseudofurnishius murcianus van den Boogaard, a characteristic conodont species of the Sephardic realm, along the section makes it one of the most important sections in the Iberian Peninsula for the study of the species. The first apparition of P. murcianus in the section corresponds with the first of Eoprotrachyceras curionii taxon, which is the principal marker for the base of the Ladinian stage in the GSSP of the Anisian-Ladinian boundary, and the age of the youngest conodonts, based on ammonoids (Epigonus Zone) is Lower Ladinian (upper Fassanian). This is similar to the range of P. murcianus in the Saharonim Formation in Israel, where its earliest appearance is also Early Fassanian (Curionii zone) age.La bioestratigrafía de la Sección de Calasparra está bien establecida mediante biozonación de ammonoideos, con una edad que va desde el Ladiniense inferior hasta el Longobardiense. La presencia continua de Pseudofurnishius murcianus van den Boogaard, una especie de conodontos característica del Dominio Sephardí, a lo largo de la sección la hace una de las más importantes de la Península Ibérica para el estudio de la especie. La primera aparición de P. murcianus en la sección se corresponde con el taxón Eoprotachyceras curionii, que es el principal marcador para la base del piso Ladiniense en el GSSP del límite Anisiense-Ladiniense, mientras que la edad de los conodontos más recientes, basada en ammonites (Epigonus Zone) es Ladiniense Inferior (Fassaniense superior) Este rango es similar al de P. murcianus en la Formación Saharonim en Israel, de edad Fassaniense inferior (Zona Curionii)

Non-circular rotating beams and CMB experiments

This paper is concerned with small angular scale experiments for the observation of cosmic microwave background anisotropies. In the absence of beam, the effects of partial coverage and pixelisation are disentangled and analyzed (using simulations). Then, appropriate maps involving the CMB signal plus the synchrotron and dust emissions from the Milky Way are simulated, and an asymmetric beam --which turns following different strategies-- is used to smooth the simulated maps. An associated circular beam is defined to estimate the deviations in the angular power spectrum produced by beam asymmetry without rotation and, afterwards, the deviations due to beam rotation are calculated. For a certain large coverage, the deviations due to pure asymmetry and asymmetry plus rotation appear to be very systematic (very similar in each simulation). Possible applications of the main results of this paper to data analysis in large coverage experiments --as PLANCK-- are outlined.Comment: 13 pages, 9 figures, to appear in A&

Sephardiellinae, a new Middle Triassic conodont subfamily

Sephardiellinae (nov. subfam.) encompasses a Middle Triassic Gondolleloid lineage that originated in the Sephardic realm, westernmost shallow Neotethys, from where, in the course of the Ladinian and earliest Carnian, some of its species spread to the world oceans, before extinction as a result of the Carnian salinity crisis. It is composed of two genera, Sephardiella and Pseudofurnishius. Differential criteria in its septimembrate apparatus are the basal cavity structure of P1 element and morphological variations in the P2 and S3 elements.La nueva subfamilia Sephardiellinae está comprendida dentro del linaje de Gondolellidae del Triásico Medio y se originó en el Dominio Sefardí, la parte más occidental del Neotetis. Durante el Ladiniense-Carniense Inferior, algunas de sus especies irradian y se distribuyen por todos los océanos. Su extinción está relacionada con la crisis de salinidad que tuvo lugar en el Carniense. La nueva subfamilia está constituida por dos géneros, Sephardiella y Pseudofurnishius las diferencias morfológicas de su aparato septimembrado, como son la estructura de la cavidad basal del elemento P1 y las variaciones morfológicas de los elementos P2 y S3, constituyen el criterio utilizado

A Biophysically-Based Model of the Optical Properties of Skin Aging

This paper presents a time-varying, multi-layered biophysically-based model of the optical properties of human skin, suitable for simulating appearance changes due to aging. We have identified the key aspects that cause such changes, both in terms of the structure of skin and its chromophore concentrations, and rely on the extensive medical and optical tissue literature for accurate data. Our model can be expressed in terms of biophysical parameters, optical parameters commonly used in graphics and rendering (such as spectral absorption and scattering coefficients), or more intuitively with higher-level parameters such as age, gender, skin care or skin type. It can be used with any rendering algorithm that uses diffusion profiles, and it allows to automatically simulate different types of skin at different stages of aging, avoiding the need for artistic input or costly capture processes

Job Embeddedness Theory: Can It Help Explain Employee Retention Among Extension Agents?

The study reported here examined Job Embeddedness theory, as introduced by Mitchell, Holtom, Lee, Sablynski, and Erez (2001), which offers a method of discovering why people stay in an organization. Extension agents in two states (N=454) reported significantly different levels of job embeddedness during the study period. Regression analyses showed that job embeddedness was significantly correlated with and predicted unique variance in intent to stay

Genetic diseases of renal phosphate handling

UNLABELLED: Renal control of systemic phosphate homeostasis is critical as evident from inborn and acquired diseases causing renal phosphate wasting. At least three transport proteins are responsible for renal phosphate reabsorption: NAPI-IIa (SLC34A1), NAPI-IIc (SLC34A3) and PIT-2 (SLC20A2). These transporters are highly regulated by various cellular mechanisms and factors including acid-base status, electrolyte balance and hormones such as dopamine, glucocorticoids, growth factors, vitamin D3, parathyroid hormone and fibroblast growth factor 23 (FGF23). Whether renal phosphate wasting is caused by inactivating mutations in the NAPI-IIa transporter is controversial. Mutations in the NAPI-IIc transporter cause hereditary hypophosphatemic rickets with hypercalciuria. Besides the primary inherited defects, there are also inherited defects in major regulators of phosphate homeostasis that lead to alterations in phosphate handling. Autosomal dominant hypophosphatemic rickets is due to FGF23 mutations leading to resistance against its own degradation. Similarly, inactivating mutations in the PHEX gene, which causes FGF23 inactivation, cause X-linked hypophosphatemia due to renal phosphate losses. In contrast, mutations in galactosamine:polypeptide N-acetyl-galactosaminyltransferase, responsible for O-glycosylation of FGF23, or in klotho, a cofactor for FGF23 signalling result in hyperphosphatemia. Acquired syndromes of renal phosphate wasting, hypophosphatemia and osteomalacia (tumour-associated osteomalacia) can be due to the excessive synthesis or release of phosphaturic factors (FGF23, FGF-7, MEPE and sFRP4) from mesenchymal tumour

Chronic Stress Triggers Expression of Immediate Early Genes and Differentially Affects the Expression of AMPA and NMDA Subunits in Dorsal and Ventral Hippocampus of Rats

Indexación: Web of Science; Scopus.Previous studies in rats have demonstrated that chronic restraint stress triggers anhedonia, depressive-like behaviors, anxiety and a reduction in dendritic spine density in hippocampal neurons. In this study, we compared the effect of repeated stress on the expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptor subunits in dorsal and ventral hippocampus (VH). Adult male Sprague-Dawley rats were randomly divided into control and stressed groups, and were daily restrained in their motion (2.5 h/day) during 14 days. We found that chronic stress promotes an increase in c-Fos mRNA levels in both hippocampal areas, although it was observed a reduction in the immunoreactivity at pyramidal cell layer. Furthermore, Arc mRNAs levels were increased in both dorsal and VH, accompanied by an increase in Arc immunoreactivity in dendritic hippocampal layers. Furthermore, stress triggered a reduction in PSD-95 and NR1 protein levels in whole extract of dorsal and VH. Moreover, a reduction in NR2A/NR2B ratio was observed only in dorsal pole. In synaptosomal fractions, we detected a rise in NR1 in dorsal hippocampus (DH). By indirect immunofluorescence we found that NR1 subunits rise, especially in neuropil areas of dorsal, but not VH. In relation to AMPA receptor (AMPAR) subunits, chronic stress did not trigger any change, either in dorsal or ventral hippocampal areas. These data suggest that DH is more sensitive than VH to chronic stress exposure, mainly altering the expression of NMDA receptor (NMDAR) subunits, and probably favors changes in the configuration of this receptor that may influence the function of this area.https://www.frontiersin.org/articles/10.3389/fnmol.2017.00244/ful