989 research outputs found
Line-of-Sight Reddening Predictions: Zero Points, Accuracies, the Interstellar Medium, and the Stellar Populations of Elliptical Galaxies
Revised (B-V)_0-Mg_2 data for 402 elliptical galaxies are given to test
reddening predictions which can also tell us both what the intrinsic errors are
in this relationship among gE galaxy stellar populations, as well as details of
nearby structure in the interstellar medium (ISM) of our Galaxy and of the
intrinsic errors in reddening predictions. Using least-squares fits, the
explicit 1-sigma errors in the Burstein-Heiles (BH) and the Schlegel et al.
(IR) predicted reddenings are calculated, as well as the 1-sigma observational
error in the (B-V)_0-Mg_2 for gE galaxies. It is found that, in directions with
E(B-V)<0.100 mag (where most of these galaxies lie), 1-sigma errors in the IR
reddening predictions are 0.006 to 0.009 in E(B-V) mag, those for BH reddening
prediction are 0.011 mag, and the 1-sigma agreement between the two reddening
predictions is 0.007 mag. IR predictions have an accuracy of 0.010-0.011 mag in
directions with E(B-V)>= 0.100 mag, significantly better than those of the BH
predictions (0.024-0.025). Gas-to-dust variations that vary by a factor of 3,
both high and low, exist along many lines-of-sight in our Galaxy. The approx
0.02 higher reddening zero point in E(B-V) previously determined by Schlegel et
al. is confirmed, primarily at the Galactic poles. Despite this, both methods
also predict many directions with E(B-V)<0.015 mag. Independent evidence of
reddening at the North Galactic pole is reviewed, with the conclusion that
there still exists directions at the NGP that have E(B-V)<<0.01. Two lines of
evidence suggest that IR reddenings are overpredicted in directions with high
gas-to-dust ratios. As high gas-to-dust directions in the ISM also include the
Galactic poles, this overprediction is the likely cause of the E(B-V) = 0.02
mag larger IR reddening zero point.Comment: 5 figure
Towards reliable diagnostics of prostate cancer via breath
Early detection of cancer is a key ingredient for saving many lives. Unfortunately, cancers of the urogenital system are difficult to detect at early stage. The existing noninvasive diagnostics of prostate cancer (PCa) suffer from low accuracy (< 70%) even at advanced stages. In an attempt to improve the accuracy, a small breath study of 63 volunteers representing three groups: (1) of 19 healthy, (2) 28 with PCa, (3) with 8 kidney cancer (KC) and 8 bladder cancer (BC) was performed. Ultrabroadband mid-infrared Fourier absorption spectroscopy revealed eight spectral ranges (SRs) that differentiate the groups. The resulting accuracies of supervised analyses exceeded 95% for four SRs in distinguishing (1) vs (2), three for (1) vs (3) and four SRs for (1) vs (2) + (3). The SRs were then attributed to volatile metabolites. Their origin and involvement in urogenital carcinogenesis are discussed
A molecular insight into algal-oomycete warfare: cDNA analysis of <i>Ectocarpus siliculosus</i> infected with the basal oomycete <i>Eurychasma dicksonii</i>
Brown algae are the predominant primary producers in coastal habitats, and like land plants are subject to disease and parasitism. Eurychasma dicksonii is an abundant, and probably cosmopolitan, obligate biotrophic oomycete pathogen of marine brown algae. Oomycetes (or water moulds) are pathogenic or saprophytic non-photosynthetic Stramenopiles, mostly known for causing devastating agricultural and aquacultural diseases. Whilst molecular knowledge is restricted to crop pathogens, pathogenic oomycetes actually infect hosts from most eukaryotic lineages. Molecular evidence indicates that Eu. dicksonii belongs to the most early-branching oomycete clade known so far. Therefore Eu. dicksonii is of considerable interest due to its presumed environmental impact and phylogenetic position. Here we report the first large scale functional molecular data acquired on the most basal oomycete to date. 9873 unigenes, totalling over 3.5Mb of sequence data, were produced from Sanger-sequenced and pyrosequenced EST libraries of infected Ectocarpus siliculosus. 6787 unigenes (70%) were of algal origin, and 3086 (30%) oomycete origin. 57% of Eu. dicksonii sequences had no similarity to published sequence data, indicating that this dataset is largely unique. We were unable to positively identify sequences belonging to the RXLR and CRN groups of oomycete effectors identified in higher oomycetes, however we uncovered other unique pathogenicity factors. These included putative algal cell wall degrading enzymes, cell surface proteins, and cyclophilin-like proteins. A first look at the host response to infection has also revealed movement of the host nucleus to the site of infection as well as expression of genes responsible for strengthening the cell wall, and secretion of proteins such as protease inhibitors. We also found evidence of transcriptional reprogramming of E. siliculosus transposable elements and of a viral gene inserted in the host genome
MIPS: The Multiband Imaging Photometer for SIRTF
The Multiband Imaging Photometer for SIRTF (MIPS) is to be designed to reach as closely as possible the fundamental sensitivity and angular resolution limits for SIRTF over the 3 to 700μm spectral region. It will use high performance photoconductive detectors from 3 to 200μm with integrating JFET amplifiers. From 200 to 700μm, the MIPS will use a bolometer cooled by an adiabatic demagnetization refrigerator. Over much of its operating range, the MIPS will make possible observations at and beyond the conventional Rayleigh diffraction limit of angular resolution
In-situ electron-beam lithography of deterministic single-quantum-dot mesa-structures using low-temperature cathodoluminescence spectroscopy
We report on the deterministic fabrication of sub-um mesa structures
containing single quantum dots by in-situ electron-beam lithography. The
fabrication method is based on a two-step lithography process using a
low-temperature cathodoluminescence (CL) spectroscopy setup. In the first step
the position and spectral features of single InGaAs quantum dots (QDs) are
detected by CL. Then circular sub-um mesa-structures are exactly defined by
high-resolution electron-beam lithography and subsequent etching in the second
step. CL spectroscopy and micro-photoluminscence spectroscopy demonstrate the
high optical quality of the single-QD mesa-structures with emission linewidths
below 15 ueV and g(2)(0) = 0.04. Our lithography method allows for an alignment
precision better than 100 nm which paves the way for a fully-deterministic
device technology using in-situ CL lithography.Comment: 4 pages, 4 figure
Study of Interplanetary Magnetic Field with Ground State Alignment
We demonstrate a new way of studying interplanetary magnetic field -- Ground
State Alignment (GSA). Instead of sending thousands of space probes, GSA allows
magnetic mapping with any ground telescope facilities equipped with
spectropolarimeter. The polarization of spectral lines that are pumped by the
anisotropic radiation from the Sun is influenced by the magnetic realignment,
which happens for magnetic field (<1G). As a result, the linear polarization
becomes an excellent tracer of the embedded magnetic field. The method is
illustrated by our synthetic observations of the Jupiter's Io and comet Halley.
Polarization at each point was constructed according to the local magnetic
field detected by spacecrafts. Both spatial and temporal variations of
turbulent magnetic field can be traced with this technique as well. The
influence of magnetic field on the polarization of scattered light is discussed
in detail. For remote regions like the IBEX ribbons discovered at the boundary
of interstellar medium, GSA provides a unique diagnostics of magnetic field.Comment: 11 pages, 19 figures, published in Astrophysics and Space Scienc
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