2,192 research outputs found
Transverse multi-mode effects on the performance of photon-photon gates
The multi-mode character of quantum fields imposes constraints on the
implementation of high-fidelity quantum gates between individual photons. So
far this has only been studied for the longitudinal degree of freedom. Here we
show that effects due to the transverse degrees of freedom significantly affect
quantum gate performance. We also discuss potential solutions, in particular
separating the two photons in the transverse direction.Comment: 5 pages, 3 figures, published versio
Effect of Seed Treatment and Foliar Fungicides on Soybean White Mold and Yield Response
Soybean white mold has been a production problem for soybean producers since early 1990. Sclerotia germinate and produce apothecia, and apothecia produce ascospores. These spores attack soybean plants at flowering. In addition, sclerotia can germinate and colonize soybean plants. Therefore, seed treatment and or foliar application may help reduce incidence and severities and yield loss due to white mold. In Iowa, for the first time in the 2009 growing season, we observed wide spread of both the soybean sudden death syndrome (SDS) and white mold (WM). Sporadically, the simultaneous occurrence of SDS and WM had only been observed once in 2007. Many growers experienced the occurrence of SDS and WM on the same farm, and some in the same field. This is complicating management strategies. Objectives of these studies were to assess effects of seed treatment and foliar spray on soybean white mold and yield response at the ISU Northeast Research Farm, Nashua, Iowa
Transient anchorage of cross-linked glycosyl-phosphatidylinositol–anchored proteins depends on cholesterol, Src family kinases, caveolin, and phosphoinositides
How outer leaflet plasma membrane components, including glycosyl-phosphatidylinositol–anchored proteins (GPIAPs), transmit signals to the cell interior is an open question in membrane biology. By deliberately cross-linking several GPIAPs under antibody-conjugated 40-nm gold particles, transient anchorage of the gold particle–induced clusters of both Thy-1 and CD73, a 5′ exonucleotidase, occurred for periods ranging from 300 ms to 10 s in fibroblasts. Transient anchorage was abolished by cholesterol depletion, addition of the Src family kinase (SFK) inhibitor PP2, or in Src-Yes-Fyn knockout cells. Caveolin-1 knockout cells exhibited a reduced transient anchorage time, suggesting the partial participation of caveolin-1. In contrast, a transmembrane protein, the cystic fibrosis transmembrane conductance regulator, exhibited transient anchorage that occurred without deliberately enhanced cross-linking; moreover, it was only slightly inhibited by cholesterol depletion or SFK inhibition and depended completely on the interaction of its PDZ-binding domain with the cytoskeletal adaptor EBP50. We propose that cross-linked GPIAPs become transiently anchored via a cholesterol-dependent SFK-regulatable linkage between a transmembrane cluster sensor and the cytoskeleton
The effect of versican G3 domain on local breast cancer invasiveness and bony metastasis
Abstract
Introduction
Increased versican expression has been associated with local breast cancer invasiveness and a more aggressive tumor phenotype. The cellular mechanisms are not fully understood and this study evaluated versican G3 domain with its EGF-like motifs in influencing tumor invasion and metastasis.
Methods
One recombinant construct was synthesized (a signal peptide for product secretion and the versican G3 domain). The construct was stably transfected into human breast carcinoma MT-1 cells. Cell viability in vitro was evaluated in low serum and serum starvation conditions. In vivo study of tumor growth was evaluated in a nude mouse model. G3 effects on rodent vascular endothelial cells were evaluated in vitro on cell survival, apoptosis, migration, and vascular formation. The effects of VEGF, fibronectin, and G3 on vascular formation were examined. An intracardiac injection model of metastatic human breast carcinoma tested the effect of G3 on distant bony and soft tissue metastasis. Analysis of metastatic burden included histology, radiographs, and micro-CT quantification of osteolysis.
Results
A greater viability of cancer cells was observed in low serum and serum-free conditions in the presence of versican G3. Larger subcutaneous tumors were obtained in the G3 group following tumor cell injection into CD1 mice. G3 induced a greater degree of rodent vascular endothelial cell proliferation and migration in vitro. Simultaneous presence of fibronectin, VEGF, and G3 promoted endothelial cell migration in wound-healing assays as compared to the treatments containing none, one or two of these molecules. Systemic tumor burden to distant bony and soft tissue metastatic sites was greater in the G3 group using the intracardiac injection metastatic model
Conclusion
Versican G3 domain appears to be important in local and systemic tumor invasiveness of human breast cancer. Effects include enhancing cell viability, proliferation, migration and enhancing local tumor growth. Potential effects on angiogenesis include enhancing vascular endothelial proliferation, migration, and vessel formation. The interactions between tumor cells, surrounding stromal components and neo-vascularization in breast cancer may include interactions with VEGF and fibronectin. The propensity of versican G3 to influence tumor invasion to bone and the mechanisms of G3 mediated osteolysis warrants ongoing studies
Probing neutrino oscillations jointly in long and very long baseline experiments
We examine the prospects of making a joint analysis of neutrino oscillation
at two baselines with neutrino superbeams. Assuming narrow band superbeams and
a 100 kt water Cerenkov calorimeter, we calculate the event rates and
sensitivities to the matter effect, the signs of the neutrino mass differences,
the CP phase and the mixing angle \theta_{13}. Taking into account all possible
experimental errors under general consideration, we explored the optimum cases
of narrow band beam to measure the matter effect and the CP violation effect at
all baselines up to 3000 km. We then focus on two specific baselines, a long
baseline of 300 km and a very long baseline of 2100 km, and analyze their joint
capabilities. We found that the joint analysis can offer extra leverage to
resolve some of the ambiguities that are associated with the measurement at a
single baseline.Comment: 23 pages, 11 figure
Empirical study on clique-degree distribution of networks
The community structure and motif-modular-network hierarchy are of great
importance for understanding the relationship between structures and functions.
In this paper, we investigate the distribution of clique-degree, which is an
extension of degree and can be used to measure the density of cliques in
networks. The empirical studies indicate the extensive existence of power-law
clique-degree distributions in various real networks, and the power-law
exponent decreases with the increasing of clique size.Comment: 9 figures, 4 page
The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
We present the discovery of nine quasars at identified in the Sloan
Digital Sky Survey (SDSS) imaging data. This completes our survey of
quasars in the SDSS footprint. Our final sample consists of 52 quasars at
, including 29 quasars with mag selected from
11,240 deg of the SDSS single-epoch imaging survey (the main survey), 10
quasars with selected from 4223 deg of the SDSS
overlap regions (regions with two or more imaging scans), and 13 quasars down
to mag from the 277 deg in Stripe 82. They span a
wide luminosity range of . This well-defined sample
is used to derive the quasar luminosity function (QLF) at . After
combining our SDSS sample with two faint ( mag) quasars from
the literature, we obtain the parameters for a double power-law fit to the QLF.
The bright-end slope of the QLF is well constrained to be
. Due to the small number of low-luminosity quasars, the
faint-end slope and the characteristic magnitude are
less well constrained, with and
mag. The spatial density of luminous quasars,
parametrized as , drops rapidly
from to 6, with . Based on our fitted QLF and assuming
an IGM clumping factor of , we find that the observed quasar population
cannot provide enough photons to ionize the IGM at \%
confidence. Quasars may still provide a significant fraction of the required
photons, although much larger samples of faint quasars are needed for more
stringent constraints on the quasar contribution to reionization.Comment: 20 pages, 12 figures, Accepted for publication in The Astrophysical
Journa
Frequent Disruption of Chromodomain Helicase DNA-Binding Protein 8 (CHD8) and Functionally Associated Chromatin Regulators in Prostate Cancer
AbstractAbnormal expression and function of chromatin regulators results in the altered chromatin structure seen in cancer. The chromatin regulator CTCF, its cofactor CHD8, and antagonistic paralogue BORIS have wide-ranging effects on gene regulation. Their concurrent expression and regulation was examined in benign, localized, and metastatic prostate cancer (PCa) arrays with extended follow-up using an automated quantitative imaging system, VECTRA. Epithelial staining was quantified and compared against a range of clinicopathologic variables. CHD8 expression was decreased in HGPIN, localized, and metastatic PCa compared to benign (P < .001). CHD8 promoter hypermethylation, assessed by Quantitative Pyrosequencing, occurred in over 45% of primary cancers in this population as well as the TGCA database. Treatment of cell lines with the demethylating agent 5-Aza-2′-deoxycytidine reinduced expression. An interesting dichotomy for CHD8 was observed within primary cancers, with higher nuclear protein expression associated with adverse clinical outcomes including extracapsular extension (P = .007), presence of metastases (P = .025) and worse PSA-recurrence free survival (P = .048). CHD8 outperformed Gleason score and predicted biochemical failure within intermediate grade prostate cancers. The BORIS/CTCF expression ratio increased in localized (P = .03) and metastatic PCa (P = .006) and was associated with higher Gleason score (P = .02), increased tumor volume (P = .02) and positive margins (P = .04). Per cell heterogeneity of expression revealed all protein expression to be more heterogeneous in cancerous tissue (both P < .001), especially high grade (P < .01). In the first detailed analysis in cancer, a marked loss of CHD8 expression and increased BORIS/CTCF ratio indicate frequent disruption of CTCF and its effector genes in PCa
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