Ala-504 is a determinant of substrate binding affinity in the mouse Na+/dicarboxylate cotransporter

AbstractThe Na+/dicarboxylate cotransporters from mouse (mNaDC1) and rabbit (rbNaDC1) differ in their ability to handle adipate, a six-carbon terminal dicarboxylic acid. The mNaDC1 and rbNaDC1 amino acid sequences are 75% identical. The rbNaDC1 does not transport adipate and only succinate produced inward currents under two-electrode voltage clamp. In contrast, oocytes expressing mNaDC1 had adipate-dependent inward currents that were about 60% of those induced by succinate. In order to identify domains involved in adipate transport, we examined the functional properties of a series of chimeric transporters made between mouse and rabbit NaDC1. We find that multiple transmembrane helices (TM), particularly TM 8, 9, and 10, are involved in adipate transport. In TM 10 there is only one amino acid difference between the two proteins, corresponding to Ala-504 in mouse and Ser-512 in rabbit NaDC1. The mNaDC1-A504S mutant had decreased adipate-dependent currents relative to succinate-dependent currents and an increase in the K0.5 for both succinate and glutarate. We conclude that multiple amino acids from TM 8, 9 and 10 contribute to the transport of adipate in NaDC1. Furthermore, Ala-504 in TM 10 is an important determinant of K0.5 for both adipate and succinate

An Analytic Model with Critical Behavior in Black Hole Formation

A simple analytic model is presented which exhibits a critical behavior in black hole formation, namely, collapse of a thin shell coupled with outgoing null fluid. It is seen that the critical behavior is caused by the gravitational nonlinearity near the event horizon. We calculate the value of the critical exponent analytically and find that it is very dependent on the coupling constants of the system.Comment: 21pp., ReVTeX, 7 figures (postscript, compressed and uuencoded), TIT/HEP-266/COSMO-4

Surface gravity in dynamical spherically symmetric spacetimes

A definition of surface gravity at the apparent horizon of dynamical spherically symmetric spacetimes is proposed. It is based on a unique foliation by ingoing null hypersurfaces. The function parametrizing the hypersurfaces can be interpreted as the phase of a light wave uniformly emitted by some far-away static observer. The definition gives back the accepted value of surface gravity in the static case by virtue of its nonlocal character. Although the definition is motivated by the behavior of outgoing null rays, it turns out that there is a simple connection between the generalized surface gravity, the acceleration of any radially moving observer, and the observed frequency change of the infalling light signal. In particular, this gives a practical and simple method of how any geodesic observer can determine surface gravity by measuring only the redshift of the infalling light wave. The surface gravity can be expressed as an integral of matter field quantities along an ingoing null line, which shows that it is a continuous function along the apparent horizon. A formula for the area change of the apparent horizon is presented, and the possibility of thermodynamical interpretation is discussed. Finally, concrete expressions of surface gravity are given for a number of four-dimensional and two-dimensional dynamical black hole solutions.Comment: 35 pages, revtex, 3 figures included using eps

Uso de imagens de radar na estimativa do ar.

O objetivo deste boletim é apresentar uma metodologia para a geração de modelo numérico de terreno (MNT), com estimativa da temperatura do ar, a partir de dados do radar SRTM. O modelo digital de elevação, gerado pela missão SRTM, forneceu as coordenadas geográficas e as altitudes necessárias para estimar-se a temperatura média do ar, utilizando-se equações de regressão múltipla. A metodologia foi eficiente na geração do mapa de temperatura média do ar do Estado de São Paulo, produto que pode ser utilizado para os mais diversos fins, tais como zoneamentos agropecuários.bitstream/item/120540/1/2249.pd

Using SAR data for soil temperature regimes classifiction in São Paulo, Brazil.

The climatic variables are used in Soil Taxonomy (Soil Survey Staff, 1999) for soil classification, because it is important to plant germination and growth, soil formation and others soil properties. Synthetic aperture radar (SAR) interferometry has been shown to be a very cost effective tool for measuring digital topography (Zyl, 2001). The data of Shuttle Radar Topography Mission (SRTM) were the results of an international mission that generate a digital elevation model (DEM) with high resolution (Souza Filho, 2003). The data were generate and provided for South America with 90m spatial resolution. The SRTM was in February, 2000 and produced the most complete terrain map of the world (Foni, Seal, 2004). A radar interferometer images a scene from two slightly different positions. In the case of a single-pass interferometer, such as SRTM, these images are acquired simultaneously. This means that one needs to separate the antenna systems in space, but always know the relative positions of the antennas in order to reconstruct the topography correctly (Zyl, 2001). The SRTM actually flew two interferometers, a C-band system, and a X-band system. The DEM generate by SRTM has a good accuracy, and besides a great advantage in the homogeneous DEM quality. Therefore, it can be used to estimate the air temperature using multiple regression analysis, based on geographic coordinates and altitude as independent variables (Pinto et al., 1972; Pedro Júnior et al., 1991; Marin et al., 2003). The Soil Taxonomy criteria to define soil temperature regimes consider soil temperature at a depth of 50cm from the soil surface, these data are rare in Brasil, and are poor to classify soil temperature regimes in brazilian territory, classifying the major portion of the country in isohyperthermic regime. The objective of this paper is present a new perspective to classify soil temperature regimes based in air temperature estimated from SRTM data, for São Paulo State

Mosquito Surveillance Program Using Ovitraps Detected Aedes aegypti at the Honolulu International Airport in 2012

mosquito surveillance program using ovitraps at the Honolulu In- ternational Airport (HIA), Hawaii, USA May 2010 to June 2012 revealed that A. albopictus egg counts fluctuated over time during the surveillance program and the highest oviposition was observed from February to May 2011 and the lowest was from September to November 2011. Positive correlations found between a given week’s rainfall and egg counts 1 and 2 weeks later suggested that rainfall triggered the hatching of eggs which were laid before the rainfall, rather than di- rectly stimulating adult oviposition. In January and June 2012, Aedes aegypti was discovered from a small vegetated area located between terminals for out-of-state and within-state flights. This species had not been confirmed present on Oahu at least since 1948. This finding has led us to intensify our surveillance program at the airport, with the hope that we would improve our understanding of the nature of mosquito introductions at this important port of entry for the Hawaiian Islands

Perturbations and Critical Behavior in the Self-Similar Gravitational Collapse of a Massless Scalar Field

This paper studies the perturbations of the continuously self-similar critical solution of the gravitational collapse of a massless scalar field (Roberts solution). The perturbation equations are derived and solved exactly. The perturbation spectrum is found to be not discrete, but occupying continuous region of the complex plane. The renormalization group calculation gives the value of the mass-scaling exponent equal to 1.Comment: 12 pages, RevTeX 3.1, 1 figur

An extreme critical space-time: echoing and black-hole perturbations

A homothetic, static, spherically symmetric solution to the massless Einstein- Klein-Gordon equations is described. There is a curvature singularity which is central, null, bifurcate and marginally trapped. The space-time is therefore extreme in the sense of lying at the threshold between black holes and naked singularities, just avoiding both. A linear perturbation analysis reveals two types of dominant mode. One breaks the continuous self-similarity by periodic terms reminiscent of discrete self-similarity, with echoing period within a few percent of the value observed numerically in near-critical gravitational collapse. The other dominant mode explicitly produces a black hole, white hole, eternally naked singularity or regular dispersal, the latter indicating that the background is critical. The black hole is not static but has constant area, the corresponding mass being linear in the perturbation amplitudes, explicitly determining a unit critical exponent. It is argued that a central null singularity may be a feature of critical gravitational collapse.Comment: 6 revtex pages, 6 eps figure

Self-Similar Collapse of Scalar Field in Higher Dimensions

This paper constructs continuously self-similar solution of a spherically symmetric gravitational collapse of a scalar field in n dimensions. The qualitative behavior of these solutions is explained, and closed-form answers are provided where possible. Equivalence of scalar field couplings is used to show a way to generalize minimally coupled scalar field solutions to the model with general coupling.Comment: RevTex 3.1, 15 pages, 3 figures; references adde

Mapeamento de áreas de preservação permanentes em topos de morros para a Amazônia Legal usando metodologia apropriada a grande volume de dados.

bitstream/item/65444/1/COT-57-Mapeamento-de-Areas-de.pd