2,551 research outputs found
ImageSpirit: Verbal Guided Image Parsing
Humans describe images in terms of nouns and adjectives while algorithms
operate on images represented as sets of pixels. Bridging this gap between how
humans would like to access images versus their typical representation is the
goal of image parsing, which involves assigning object and attribute labels to
pixel. In this paper we propose treating nouns as object labels and adjectives
as visual attribute labels. This allows us to formulate the image parsing
problem as one of jointly estimating per-pixel object and attribute labels from
a set of training images. We propose an efficient (interactive time) solution.
Using the extracted labels as handles, our system empowers a user to verbally
refine the results. This enables hands-free parsing of an image into pixel-wise
object/attribute labels that correspond to human semantics. Verbally selecting
objects of interests enables a novel and natural interaction modality that can
possibly be used to interact with new generation devices (e.g. smart phones,
Google Glass, living room devices). We demonstrate our system on a large number
of real-world images with varying complexity. To help understand the tradeoffs
compared to traditional mouse based interactions, results are reported for both
a large scale quantitative evaluation and a user study.Comment: http://mmcheng.net/imagespirit
Prevalence of Tidal Interactions among Local Seyfert Galaxies
No mechanisms have hitherto been conclusively demonstrated to be responsible
for initiating optically-luminous nuclear (Seyfert) activity in local disk
galaxies. Only a small minority of such galaxies are visibly disturbed in
optical starlight, with the observed disturbances being at best marginally
stronger than those found in matched samples of inactive galaxies. Here, we
report the first systematic study of an optically-selected sample of
twenty-three active galaxies in atomic hydrogen (HI) gas, which is the most
sensitive and enduring tracer known of tidal interactions. Eighteen of these
galaxies are (generally) classified as Seyferts, with over half (and perhaps
all) having [OIII] luminosities within two orders of magnitude of Quasi-Stellar
Objects. Only ~28% of these Seyfert galaxies are visibly disturbed in optical
DSS2 images. By contrast, ~94% of the same galaxies are disturbed in HI, in
nearly all cases not just spatially but also kinematically on galactic (>~20
kpc) scales. In at least ~67% and perhaps up to ~94% of cases, the observed HI
disturbances can be traced to tidal interactions with neighboring galaxies
detected also in HI. The majority of these neighboring galaxies have projected
separations of <~ 100 kpc and differ in radial velocities by <~100 km/s from
their respective Seyfert galaxies, and many have optical luminosities ranging
from the Small to Large Magellanic Clouds. In a companion paper, we show that
only ~15% of a matched control sample of inactive galaxies display comparable
HI disturbances. Our results suggest that: i) most Seyfert galaxies (with high
nuclear luminosities) have experienced tidal interactions in the recent past;
ii) in most cases, these tidal interactions are responsible for initiating
events that lead to their nuclear activity.Comment: 64 pages, 44 figures, accepted for publication in ApJ. Changes:
Nothing is changed except that the paper was compiled differently to reduce
the number of pages. To be friendly to the Earth forest, you could also
choose to only print the text part of the paper and view images on line. (see
http://www.astro.virginia.edu/~ck2v/paper/
Molecular evolution of measles viruses circulated in Taiwan 1992-2008
Genetic analyses of viral samples from 74 laboratory confirmed measles cases occurring in Taiwan during 1992-2008 identified six viral genotypes D3, D5, D9, G2, H1 and H2. The most frequently detected genotype, H1, was associated with outbreaks in 1994 and 2002, and was the likely indigenous genotype in 1992. In response to the outbreaks, two catch-up campaigns were launched and a routine second dose of measles, mumps, and rubella vaccine at entry to elementary school was introduced. The vaccination campaigns successfully reduced the number of measles cases in Taiwan, and many of the more recent cases can be traced to importations, primarily from other Asian countries. A number of measles genotypes which were associated with outbreaks in other Asian countries were detected among the more recent cases. The more recent genotype H1 viruses had sequences that were identical to those currently circulating in China or associated with international importation of virus
Si Microwire-Array Photocathodes Decorated with Cu Allow CO₂ Reduction with Minimal Parasitic Absorption of Sunlight
High loadings of Cu were integrated on the light-facing side of Si microwire arrays used under simulated sunlight for the photoelectrochemical reduction of CO₂ (aq) to hydrocarbons in 0.10 M KHCO₃ (aq). Radial-junction n⁺p-Si microwire arrays decorated with Cu exhibited absolute photocurrent densities comparable to an uncovered Si surface. Moreover, with respect to a Cu foil electrode, the positive shift in the onset potential for hydrocarbon formation at n⁺p-Si/Cu microwire arrays was equal to or greater than the photovoltage of the semiconductor alone. Selective electrodeposition of Cu on the tips and sidewalls of Si microwires was responsible for the minimal parasitic reflection and absorption exhibited by the catalyst, such that light-limited, absolute current densities >25 mA·cm⁻² were sustained for 48 h under simulated sunlight. Photoelectrodes prepared from semiconductors with low diode quality factors and electrocatalysts with large Tafel slopes are shown to benefit from increased microstructured surface area. Si microwire arrays are thus suitable for photoelectrochemical reactions requiring high loadings of metallic and reflective electrocatalysts
Si Microwire-Array Photocathodes Decorated with Cu Allow CO₂ Reduction with Minimal Parasitic Absorption of Sunlight
High loadings of Cu were integrated on the light-facing side of Si microwire arrays used under simulated sunlight for the photoelectrochemical reduction of CO₂ (aq) to hydrocarbons in 0.10 M KHCO₃ (aq). Radial-junction n⁺p-Si microwire arrays decorated with Cu exhibited absolute photocurrent densities comparable to an uncovered Si surface. Moreover, with respect to a Cu foil electrode, the positive shift in the onset potential for hydrocarbon formation at n⁺p-Si/Cu microwire arrays was equal to or greater than the photovoltage of the semiconductor alone. Selective electrodeposition of Cu on the tips and sidewalls of Si microwires was responsible for the minimal parasitic reflection and absorption exhibited by the catalyst, such that light-limited, absolute current densities >25 mA·cm⁻² were sustained for 48 h under simulated sunlight. Photoelectrodes prepared from semiconductors with low diode quality factors and electrocatalysts with large Tafel slopes are shown to benefit from increased microstructured surface area. Si microwire arrays are thus suitable for photoelectrochemical reactions requiring high loadings of metallic and reflective electrocatalysts
BING: Binarized normed gradients for objectness estimation at 300fps
Training a generic objectness measure to produce object proposals has recently become of significant interest. We observe that generic objects with well-defined closed boundaries can be detected by looking at the norm of gradients, with a suitable resizing of their corresponding image windows to a small fixed size. Based on this observation and computational reasons, we propose to resize the window to 8 × 8 and use the norm of the gradients as a simple 64D feature to describe it, for explicitly training a generic objectness measure. We further show how the binarized version of this feature, namely binarized normed gradients (BING), can be used for efficient objectness estimation, which requires only a few atomic operations (e.g., add, bitwise shift, etc.). To improve localization quality of the proposals while maintaining efficiency, we propose a novel fast segmentation method and demonstrate its effectiveness for improving BING’s localization performance, when used in multithresholding straddling expansion (MTSE) postprocessing. On the challenging PASCAL VOC2007 dataset, using 1000 proposals per image and intersectionover- union threshold of 0.5, our proposal method achieves a 95.6% object detection rate and 78.6% mean average best overlap in less than 0.005 second per image
Highly efficient mode-locked and Q-switched Er3+-doped fiber lasers using a gold nanorod saturable absorber
Mode-locked and Q-switched pulsed fiber laser sources with wavelengths of 1.55 mu m are widely used in various fields. Gold nanorods (GNRs) have been applied in biomedicine and optics owing to their biocompatibility, easy fabrication, and unique optical properties. This paper presents the analysis of a saturable absorber based on a colloidal gold nanorod (GNR) thin film for dual-function passively mode-locked and Q-switched 1.55-mu m fiber lasers. The colloidal GNR thin film possesses superior properties such as a wide operating wavelength range, large nonlinear absorption coefficient, and a picosecond-order recovery time. Its modulation depth and saturation intensity at 1.55 mu m are 7.8% and 6.55 MW/cm(2), respectively. Passive mode-locked or Q-switched laser operation is achieved by changing the number of GNR thin-film layers. The advantages of these high-quality GNRs in mode-locked and Q-switched fiber lasers with record-high slope efficiency are verified by conducting comprehensive material and laser dynamic analyses. The self-starting mode-locked fiber laser with an efficiency as high as 24.91% and passively Q-switched fiber laser with the maximum energy of 0.403 mu J are successfully demonstrated. This paper presents the novel demonstration of reconfigurable mode-locked and Q-switched all-fiber lasers by incorporating colloidal GNR thin films
Glycosylphosphatidylinositol-Anchored Anti-HIV scFv Efficiently Protects CD4 T Cells from HIV-1 Infection and Deletion in hu-PBL Mice
ABSTRACT Despite success in viral inhibition and CD4 T cell recovery by highly active antiretroviral treatment (HAART), HIV-1 is still not curable due to the persistence of the HIV-1 reservoir during treatment. One patient with acute myeloid leukemia who received allogeneic hematopoietic stem cell transplantation from a homozygous CCR5 Δ32 donor has had no detectable viremia for 9 years after HAART cessation. This case has inspired a field of HIV-1 cure research focusing on engineering HIV-1 resistance in permissive cells. Here, we employed a glycosylphosphatidylinositol (GPI)-scFv X5 approach to confer resistance of human primary CD4 T cells to HIV-1. We showed that primary CD4 T cells expressing GPI-scFv X5 were resistant to CCR5 (R5)-, CXCR4 (X4)-, and dual-tropic HIV-1 and had a survival advantage compared to control cells ex vivo . In a hu-PBL mouse study, GPI-scFv X5-transduced CD4 T cells were selected in peripheral blood and lymphoid tissues upon HIV-1 infection. Finally, GPI-scFv X5-transduced CD4 T cells, after being cotransfused with HIV-infected cells, showed significantly reduced viral loads and viral RNA copy numbers relative to CD4 cells in hu-PBL mice compared to mice with GPI-scFv AB65-transduced CD4 T cells. We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections. IMPORTANCE Blocking of HIV-1 entry is one of most promising approaches for therapy. Genetic disruption of the HIV-1 coreceptor CCR5 by nucleases in T cells is under 2 clinical trials and leads to reduced viremia in patients. However, the emergence of viruses using the CXCR4 coreceptor is a concern for therapies applying single-coreceptor disruption. Here, we report that HIV-1-permissive CD4 T cells engineered with GPI-scFv X5 are resistant to R5-, X4-, or dual-tropic virus infection ex vivo . In a preclinical study using hu-PBL mice, we show that CD4 T cells were protected and that GPI-scFv X5-transduced cells were selected in HIV-1-infected animals. Moreover, we show that GPI-scFv X5-transduced CD4 T cells exerted a negative effect on virus replication in vivo . We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections
Prevalence of Tidal Interactions among Local Seyfert Galaxies: The Control Experiment
We test whether there is a relation between the observed tidal interactions
and Seyfert activity by imaging in HI twenty inactive galaxies at the same
spatial resolution and detection threshold as the Seyfert sample. This control
sample of inactive galaxies were closely matched in Hubble type, range in size
and inclination, and have roughly comparable galaxy optical luminosity to the
Seyfert galaxies. We find that only ~15% of the galaxies in our control sample
are disturbed in HI, whereas the remaining ~85% show no disturbances whatsoever
in HI. Even at a spatial resolution of ~10 kpc, none of the latter galaxies
show appreciable HI disturbances reminiscent of tidal features.
In a companion paper (Kuo et al. 2008), we report results from the first
systematic imaging survey of Seyfert galaxies in atomic hydrogen (HI) gas. We
find that only ~28% of the eighteen Seyfert galaxies in that sample are visibly
disturbed in optical starlight. By contrast, ~94% of the same Seyfert galaxies
are disturbed spatially and usually also kinematically in HI gas on galactic
scales of >~20 kpc. In at least ~67% and up to perhaps ~94% of cases, the
observed disturbances can be traced to tidal interactions with neighboring
galaxies detected also in HI. The dramatic contrast between the observed
prevalence of HI disturbances in the Seyfert and control samples implicates
tidal interactions in initiating events that lead to luminous Seyfert activity
in a large fraction of local disk galaxies.Comment: 38 pages, 27 figures, Accepted for publication in ApJ. Changes from
previous version: The title of the previous version of this paper appeared in
Astroph was incorrect. It has been replaced with the correct on
A new method for identifying causal genes of schizophrenia and anti-tuberculosis drug-induced hepatotoxicity
Schizophrenia (SCZ) may cause tuberculosis, the treatments for which can induce anti-tuberculosis drug-induced hepatotoxicity (ATDH) and SCZ-like disorders. To date, the causal genes of both SCZ and ATDH are unknown. To identify them, we proposed a new network-based method by integrating network random walk with restart algorithm, gene set enrichment analysis, and hypergeometric test; using this method, we identified 500 common causal genes. For gene validation, we created a regularly updated online database ATDH-SCZgenes and conducted a systematic meta-analysis of the association of each gene with either disease. Till now, only GSTM1 and GSTT1 have been well studied with respect to both diseases; and a total of 23 high-quality association studies were collected for the current meta-analysis validation. Finally, the GSTM1 present genotype was confirmed to be significantly associated with both ATDH [Odds Ratio (OR): 0.71, 95% confidence interval (CI): 0.56–0.90, P = 0.005] and SCZ (OR: 0.78, 95% CI: 0.66–0.92, P = 0.004) according to the random-effect model. Furthermore, these significant results were supported by “moderate” evidence according to the Venice criteria. Our findings indicate that GSTM1 may be a causal gene of both ATDH and SCZ, although further validation pertaining to other genes, such as CYP2E1 or DRD2, is necessary
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