95 research outputs found
Hepatocyte growth factor enhances proteolysis and invasiveness of human nasopharyngeal cancer cells through activation of PI3K and JNK
AbstractThe hepatocyte growth factor (HGF) receptor, Met, is frequently overexpressed in nasopharyngeal cancer (NPC). Here, we showed for the first time that human NPC cells with high Met expression were more sensitive to the cell motility and invasion effect of HGF. The downregulation of Met by small interfering RNA decreased tumor cell invasion/migration. HGF significantly increased matrix metalloproteinase-9 production. This was inhibited by blocking phosphatidylinositide 3-kinase (PI3K) and c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase signaling pathways. We also demonstrated that PI3K induced activation of JNK, with Akt as a potential point of this cross-talk. These results provide new insights into the molecular mechanism responsible for NPC progression and metastasis
Cosmic Acceleration in Brans-Dicke Cosmology
We consider Brans-Dicke theory with a self-interacting potential in Einstein
conformal frame. We show that an accelerating expansion is possible in a
spatially flat universe for large values of the Brans-Dicke parameter
consistent with local gravity experiments.Comment: 10 Pages, 3 figures, To appear in General Relativity and Gravitatio
Lipocalin-2 Deficiency Attenuates Insulin Resistance Associated With Aging and Obesity
OBJECTIVE - The proinflammatory cytokines/adipokines produced from adipose tissue act in an autocrine and/or endocrine manner to perpetuate local inflammation and to induce peripheral insulin resistance. The present study investigates whether lipocalin-2 deficiency or replenishment with this adipokine has any impact on systemic insulin sensitivity and the underlying mechanisms. METHODS AND RESULTS - Under conditions of aging or dietary-/genetic-induced obesity, lipocalin-2 knockout (Lcn2-KO) mice show significantly decreased fasting glucose and insulin levels and improved insulin sensitivity compared with their wild-type littermates. Despite enlarged fat mass, inflammation and the accumulation of lipid peroxidation products are significantly attenuated in the adipose tissues of Lcn2-KO mice. Adipose fatty acid composition of these mice varies significantly from that in wild-type animals. The amounts of arachidonic acid (C20:4 n6) are elevated by aging and obesity and are paradoxically further increased in adipose tissue, but not skeletal muscle and liver of Lcn2-KO mice. On the other hand, the expression and activity of 12-lipoxygenase, an enzyme responsible for metabolizing arachidonic acid, and the production of tumor necrosis factor-α (TNF-α), a critical insulin resistance-inducing factor, are largely inhibited by lipocalin-2 deficiency. Lipocalin-2 stimulates the expression and activity of 12-lipoxygenase and TNF-α production in fat tissues. Cinnamyl-3,4- dihydroxy-α-cyanocinnamate (CDC), an arachidonate lipoxygenase inhibitor, prevents TNF-α expression induced by lipocalin-2. Moreover, treatment with TNF-α neutralization antibody or CDC significantly attenuated the differences of insulin sensitivity between wild-type and Lcn2-KO mice. CONCLUSIONS - Lipocalin-2 deficiency protects mice from developing aging- and obesity-induced insulin resistance largely by modulating 12-lipoxygenase and TNF-α levels in adipose tissue. © 2010 by the American Diabetes Association.link_to_OA_fulltex
Planck 2015 results. XXVII. The Second Planck Catalogue of Sunyaev-Zeldovich Sources
We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sources detected from the 29 month full-mission data. The catalogue (PSZ2) is the largest SZ-selected sample of galaxy clusters yet produced and the deepest all-sky catalogue of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external data-sets, and is the first SZ-selected cluster survey containing > confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the Y5R500 estimates are robust to pressure-profile variation and beam systematics, but accurate conversion to Y500 requires. the use of prior information on the cluster extent. We describe the multi-wavelength search for counterparts in ancillary data, which makes use of radio, microwave, infra-red, optical and X-ray data-sets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of low-redshift X-ray under- luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT X-ray selected samples
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set
This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees
Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network
Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism
L2 (English) spelling is positively correlated with L2 vocabulary size, but not with a measure that putatively taps visual statistical learning
Recent studies showed that a person’s visual statistical learning (VSL) ability is positively correlated with L1 and L2 literacy development. That is, people who are more adept at detecting implicit regularities in visual inputs tend to be or to become better readers. Most if not all studies that examined this link looked only into reading ability, oddly neglecting spelling, and importantly, they all relied on relatively small sample sizes. In light of these, we recruited a relatively large sample (64 advanced English learners) to investigate if performance on a commonly adopted VSL task (i.e., embedded triplet task) correlates with L2 (English) spelling proficiency, as indexed by a spelling test involving highly rare regular English words. We also administered a rote memorization task and an L2 vocabulary size test. In line with a growing body of literature, we found no evidence that performance on the VSL task correlated with L2 spelling. We did however find clear evidence that L2 learners with a larger L2 vocabulary size are also better spellers. We argue that while SL is linked to literacy development, traditional VSL measures may not be suitable for the investigation of individual differences owing to poor sensitivity. Our study, alongside Mak (2016), also demonstrates that false positives may arise due to small sample sizes. We, therefore, urge researchers worldwide, especially those interested in individual differences, to work towards reproducibility and better science by for example avoiding unjustifiably small sample sizes
- …