Detectability of dissipative motion in quantum vacuum via superradiance

We propose an experiment for generating and detecting vacuum-induced dissipative motion. A high frequency mechanical resonator driven in resonance is expected to dissipate energy in quantum vacuum via photon emission. The photons are stored in a high quality electromagnetic cavity and detected through their interaction with ultracold alkali-metal atoms prepared in an inverted population of hyperfine states. Superradiant amplification of the generated photons results in a detectable radio-frequency signal temporally distinguishable from the expected background.Comment: 4 pages, 2 figure

Regional coherence evaluation in mild cognitive impairment and Alzheimer's disease based on adaptively extracted magnetoencephalogram rhythms

This study assesses the connectivity alterations caused by Alzheimer's disease (AD) and mild cognitive impairment (MCI) in magnetoencephalogram (MEG) background activity. Moreover, a novel methodology to adaptively extract brain rhythms from the MEG is introduced. This methodology relies on the ability of empirical mode decomposition to isolate local signal oscillations and constrained blind source separation to extract the activity that jointly represents a subset of channels. Inter-regional MEG connectivity was analysed for 36 AD, 18 MCI and 26 control subjects in δ, θ, α and β bands over left and right central, anterior, lateral and posterior regions with magnitude squared coherence—c(f). For the sake of comparison, c(f) was calculated from the original MEG channels and from the adaptively extracted rhythms. The results indicated that AD and MCI cause slight alterations in the MEG connectivity. Computed from the extracted rhythms, c(f) distinguished AD and MCI subjects from controls with 69.4% and 77.3% accuracies, respectively, in a full leave-one-out cross-validation evaluation. These values were higher than those obtained without the proposed extraction methodology

Time-Dependent Physicochemical Changes of Carbonate Surfaces from SmartWater (Diluted Seawater) Flooding Processes for Improved Oil Recovery.

Over the past few decades, field- and laboratory-scale studies have shown enhancements in oil recovery when reservoirs, which contain high-salinity formation water (FW), are waterflooded with modified-salinity salt water (widely referred to as the low-salinity, dilution, or SmartWater effect for improved oil recovery). In this study, we investigated the time dependence of the physicochemical processes that occur during diluted seawater (i.e., SmartWater) waterflooding processes of specific relevance to carbonate oil reservoirs. We measured the changes to oil/water/rock wettability, surface roughness, and surface chemical composition during SmartWater flooding using 10-fold-diluted seawater under mimicked oil reservoir conditions with calcite and carbonate reservoir rocks. Distinct effects due to SmartWater flooding were observed and found to occur on two different timescales: (1) a rapid (<15 min) increase in the colloidal electrostatic double-layer repulsion between the rock and oil across the SmartWater, leading to a decreased oil/water/rock adhesion energy and thus increased water wetness and (2) slower (>12 h to complete) physicochemical changes of the calcite and carbonate reservoir rock surfaces, including surface roughening via the dissolution of rock and the reprecipitation of dissolved carbonate species after exchanging key ions (Ca2+, Mg2+, CO32-, and SO42- in carbonates) with those in the flooding SmartWater. Our experiments using crude oil from a carbonate reservoir reveal that these reservoir rock surfaces are covered with organic-ionic preadsorbed films (ad-layers), which the SmartWater removes (detaches) as flakes. Removal of the organic-ionic ad-layers by SmartWater flooding enhances oil release from the surfaces, which was found to be critical to increasing the water wetness and significantly improving oil removal from carbonates. Additionally, the increase in water wetness is further enhanced by roughening of the rock surfaces, which decreases the effective contact (interaction) area between the oil and rock interfaces. Furthermore, we found that the rate of these slower physicochemical changes to the carbonate rock surfaces increases with increasing temperature (at least up to an experimental temperature of 75 °C). Our results suggest that the effectiveness of improved oil recovery from SmartWater flooding depends strongly on the formation of the organic-ionic ad-layers. In oil reservoirs where the ad-layer is fully developed and robust, injecting SmartWater would lead to significant removal of the ad-layer and improved oil recovery

The EphB4 receptor promotes the growth of melanoma cells expressing the ephrin-B2 ligand

Cutaneous melanoma is the most aggressive form of skin cancer and several families of receptor tyrosine kinases have been implicated in its development and progression, including the Eph receptor family (Hess et al., 2007; Smalley et al., 2009). Among Eph receptors, EphA2 has been most extensively studied in melanoma and linked to increased malignancy (Hess et al., 2007; Margaryan et al., 2009).Fil: Yang, Nai Ying . University of California; Estados UnidosFil: Lopez Bergami, Pablo Roberto. Sanford-burnham Medical Research Institute; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Goydos, James S.. Robert Wood Johnson Medical School; Estados UnidosFil: Yip, Dana . Robert Wood Johnson Medical School; Estados UnidosFil: Walker, Ameae . University of California; Estados UnidosFil: Pasquale, Elena B.. Sanford-burnham Medical Research Institute; Estados UnidosFil: Ethell, Iryna. University of California; Estados Unido

Constructing a WISE High Resolution Galaxy Atlas

After eight months of continuous observations, the Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at 3.4 {\mu}m, 4.6 {\mu}m, 12 {\mu}m and 22 {\mu}m. We have begun a dedicated WISE High Resolution Galaxy Atlas (WHRGA) project to fully characterize large, nearby galaxies and produce a legacy image atlas and source catalogue. Here we summarize the deconvolution technique used to significantly improve the spatial resolution of WISE imaging, specifically designed to study the internal anatomy of nearby galaxies. As a case study, we present results for the galaxy NGC 1566, comparing the WISE super-resolution image processing to that of Spitzer, GALEX and ground-based imaging. The is the first paper in a two part series; results for a much larger sample of nearby galaxies is presented in the second paper.Comment: Published in the AJ (2012, AJ, 144, 68

Physiological Profile of Brazilian Elite Soccer Players: Comparison between U-17, U-20 and professionals

Possible differences in the physical values ​​related to characteristics of the age group and the play positions in soccer. The aims to analyze the isokinetic muscle strength profiles, anthropometric, neuromuscular and cardiovascular characteristics, comparing age, categories and play positions. 105 players divided into U-17, U-20, Professional and six play positions. The isokinetic test, anthropometric measurements, counter-movement jump test with arms and yo-yo intermittent recovery test were performed. Significant differences (p<0.05) were found in the professionals compared to U-20 and U-17 for body mass, height, body fat, VO2max and for U-17 in relation to professionals in the isokinetic test. Significant differences were also found between play positions (p<0.05) for body mass, height, VO2max and isokinetic. Soccer athletes playing in different positions have different profiles of physiological characteristics and U-17 have a lower level of strength compared to professionals, suggesting the importance of training specificity

Dark Energy or Apparent Acceleration Due to a Relativistic Cosmological Model More Complex than FLRW?

We use the Szekeres inhomogeneous relativistic models in order to fit supernova combined data sets. We show that with a choice of the spatial curvature function that is guided by current observations, the models fit the supernova data almost as well as the LCDM model without requiring a dark energy component. The Szekeres models were originally derived as an exact solution to Einstein's equations with a general metric that has no symmetries and are regarded as good candidates to model the true lumpy universe that we observe. The null geodesics in these models are not radial. The best fit model found is also consistent with the requirement of spatial flatness at CMB scales. The first results presented here seem to encourage further investigations of apparent acceleration using various inhomogeneous models and other constraints from CMB and large structure need to be explored next.Comment: 6 pages, 1 figure, matches version published in PR

Altered prostanoid production by fibroblasts cultured from the lungs of human subjects with idiopathic pulmonary fibrosis

BACKGROUND: Prostanoids are known to participate in the process of fibrogenesis. Because lung fibroblasts produce prostanoids and are believed to play a central role in the pathogenesis of idiopathic pulmonary fibrosis (IPF), we hypothesized that fibroblasts (HF) cultured from the lungs of patients with IPF (HF-IPF) have an altered balance between profibrotic (thromboxane [TX]A(2)) and antifibrotic (prostacyclin [PGI(2)]) prostaglandins (PGs) when compared with normal human lung fibroblasts (HF-NL). METHODS: We measured inducible cyclooxygenase (COX)-2 gene and protein expression, and a profile of prostanoids at baseline and after IL-1β stimulation. RESULTS: In both HF-IPF and HF-NL COX-2 expression was undetectable at baseline, but was significantly upregulated by IL-1β. PGE(2) was the predominant COX product in IL-1β-stimulated cells with no significant difference between HF-IPF and HF-NL (28.35 [9.09–89.09] vs. 17.12 [8.58–29.33] ng/10(6) cells/30 min, respectively; P = 0.25). TXB(2) (the stable metabolite of TXA(2)) production was significantly higher in IL-1β-stimulated HF-IPF compared to HF-NL (1.92 [1.27–2.57] vs. 0.61 [0.21–1.64] ng/10(6) cells/30 min, respectively; P = 0.007) and the ratio of PGI(2) (as measured by its stable metabolite 6-keto-PGF(1α)) to TXB(2) was significantly lower at baseline in HF-IPF (0.08 [0.04–0.52] vs. 0.12 [0.11–0.89] in HF-NL; P = 0.028) and with IL-1β stimulation (0.24 [0.05–1.53] vs. 1.08 [0.51–3.79] in HF-NL; P = 0.09). CONCLUSION: An alteration in the balance of profibrotic and antifibrotic PGs in HF-IPF may play a role in the pathogeneses of IPF

CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources

We have assembled an 8.4 GHz survey of bright, flat-spectrum (alpha > -0.5) radio sources with nearly uniform extragalactic (|b|>10 deg) coverage for sources brighter than S_{4.8 GHz} = 65 mJy. The catalog is assembled from existing observations (especially CLASS and the Wright et al. PMN-CA survey), augmented by reprocessing of archival VLA and ATCA data and by new observations to fill in coverage gaps. We refer to this program as CRATES, the Combined Radio All-sky Targeted Eight GHz Survey. The resulting catalog provides precise positions, sub-arcsecond structures, and spectral indices for some 11,000 sources. We describe the morphology and spectral index distribution of the sample and comment on the survey's power to select several classes of interesting sources, especially high energy blazars. Comparison of CRATES with other high-frequency surveys also provides unique opportunities for identification of high-power radio sources.Comment: 23 pages, 7 figures, 2 machine-readable tables available at http://astro.stanford.edu/CRATES/ ; accepted for publication in ApJ

High star formation rates as the origin of turbulence in early and modern disk galaxies

High spatial and spectral resolution observations of star formation and kinematics in early galaxies have shown that two-thirds are massive rotating disk galaxies with the remainder being less massive non-rotating objects. The line of sight averaged velocity dispersions are typically five times higher than in today's disk galaxies. This has suggested that gravitationally-unstable, gas-rich disks in the early Universe are fuelled by cold, dense accreting gas flowing along cosmic filaments and penetrating hot galactic gas halos. However these accreting flows have not been observed, and cosmic accretion cannot power the observed level of turbulence. Here we report on a new sample of rare high-velocity-dispersion disk galaxies we have discovered in the nearby Universe where cold accretion is unlikely to drive their high star-formation rates. We find that the velocity dispersion is most fundamentally correlated with their star-formation rates, and not their mass nor gas fraction, which leads to a new picture where star formation itself is the energetic driver of galaxy disk turbulence at all cosmic epochs.Comment: 9 pages, 2 figures, Supplimentary Info available at: http://pulsar.swin.edu.au/~agreen/nature/sigma_mean_arXiv.pdf. Accepted for publication in Natur