The Twitter social network has become a target platform for both promoters and stammers to disseminate their target messages. There are a large number of campaigns containing coordinated spam or ...promoting accounts in Twitter, which are more harmful than the traditional methods, such as email spamming. Since traditional solutions mainly check individual accounts or messages, it is an urgent task to detect spam and promoting campaigns in Twitter. In this paper, we propose a scalable framework to detect both spam and promoting campaigns. Our framework consists of three steps: firstly linking accounts who post URLs for similar purposes, secondly extracting candidate campaigns which may exist for spam or promoting purpose and finally distinguishing their intents. One salient aspect of the framework is introducing a URL-driven estimation method to measure the similarity between accounts' purposes of posting URLs, the other one is proposing multiple features to distinguish the candidate campaigns based on a machine learning method. Over a large-scale dataset from Twitter, we can extract the actual campaigns with high precision and recall and distinguish the majority of the candidate campaigns correctly.
We report on charge state measurements of laser-accelerated carbon ions in the energy range of several MeV penetrating a dense partially ionized plasma. The plasma was generated by irradiation of a ...foam target with laser-induced hohlraum radiation in the soft x-ray regime. We use the tricellulose acetate (C_{9}H_{16}O_{8}) foam of 2 mg/cm^{3} density and 1 mm interaction length as target material. This kind of plasma is advantageous for high-precision measurements, due to good uniformity and long lifetime compared to the ion pulse length and the interaction duration. We diagnose the plasma parameters to be T_{e}=17 eV and n_{e}=4×10^{20} cm^{-3}. We observe the average charge states passing through the plasma to be higher than those predicted by the commonly used semiempirical formula. Through solving the rate equations, we attribute the enhancement to the target density effects, which will increase the ionization rates on one hand and reduce the electron capture rates on the other hand. The underlying physics is actually the balancing of the lifetime of excited states versus the collisional frequency. In previous measurement with partially ionized plasma from gas discharge and z pinch to laser direct irradiation, no target density effects were ever demonstrated. For the first time, we are able to experimentally prove that target density effects start to play a significant role in plasma near the critical density of Nd-glass laser radiation. The finding is important for heavy ion beam driven high-energy-density physics and fast ignitions. The method provides a new approach to precisely address the beam-plasma interaction issues with high-intensity short-pulse lasers in dense plasma regimes.
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Statins are Hydroxymethylglutaryl-coenzyme A reductase inhibitors, which are typically used to lower blood cholesterol. Additional beneficial effects, including improvement to pulmonary arterial ...hypertension (PAH), have also been confirmed. However, the mechanisms underlying this improvement have not yet been clarified. The present study was conducted to determine if fluvastatin was protective against experimental PAH development and to investigate the potential effects of fluvastatin on caveolin‑1 (cav‑1) expression. Rats were randomized to either receive a single subcutaneous injection of monocrotaline (MCT; 60 mg/kg; MCT group) or a single subcutaneous injection of MCT (60 mg/kg) followed by an oral gavage of fluvastatin (10 mg/kg) once daily until day 42 (M + F group). Rats in the MCT group received an equivalent volume of saline following the MCT injection. Six additional rats were given an equivalent volume of saline throughout as a control measure. PAH associated variables and cav‑1 protein expression were measured in each group at various times during the experimental period. Hemodynamic and morphometric analysis revealed that M + F rats developed moderate, delayed PAH. Cav‑1 western blot analysis demonstrated that cav‑1 expression was not significantly different in fluvastatin treated rats; however, MCT injured rats given saline had markedly reduced cav‑1 expression. It was concluded that fluvastatin may protect against PAH development and ameliorate MCT induced inhibition of cav‑1 expression in rats.
Aiming at the problems of traditional equipment fault diagnosis, such as poor real-time performance, low efficiency and strong subjectivity, a method of industrial equipment sub-health status ...monitoring based on big data technology was proposed. Firstly, the characteristic engineering of vibration signals is formed by preprocessing vibration signals collected by sensors located near the bearing shaft. Then, the deep residual shrinkage network DRSN was used to build the classification model. By tuning the model parameters, the optimal sub-health status identification model of industrial equipment was obtained. Finally, the accuracy, robustness and generalization of the model were verified. Experimental results show that this method has better generalization performance and can significantly improve the accuracy of industrial equipment fault diagnosis, which has important theoretical value and practical significance to solve the sub-health problems of industrial equipment.
The new hohlraum experimental platform and the quasi-3D simulation model are developed to enable the study of the indirect drive experiment using the six-cylinder-port hohlraum for the first time. It ...is also the first implosion experiment for the six laser-entrance-hole hohlraum to effectively use all the laser beams of the laser facility that is primarily designed for the cylindrical hohlraum. The experiments performed at the 100 kJ Laser Facility produce a peak hohlraum radiation temperature of ∼222 eV for ∼80 kJ and 2 ns square laser pulse. The inferred x-ray conversion efficiency η∼87% is similar to the cylindrical hohlraum and higher than the octahedral spherical hohlraum at the same laser facility, while the low laser backscatter is similar to the outer cone of the cylindrical hohlraum. The hohlraum radiation temperature and M-band (>1.6 keV) flux can be well reproduced by the quasi-3D simulation. The variations of the yield-over-clean and the hot spot shape can also be semiquantitatively explained by the calculated major radiation asymmetry of the quasi-3D simulation. Our work demonstrates the capability for the study of the indirect drive with the six-cylinder-port hohlraum at the cylindrically configured laser facility, which is essential for numerically assessing the laser energy required by the ignition-scale six-cylinder-port hohlraum.
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Attosecond light sources have provided insight into the fastest atomic-scale electronic dynamics. True attosecond-pump–attosecond-probe experiments require a single attosecond pulse at high intensity ...and large photon energy, a challenge that has yet to be conquered. Here we show 100-TW single attosecond x-ray pulses with unprecedented intensity of
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and duration 8.0 as can be produced by intense laser irradiation of a capacitor-nanofoil target composed of two separate nanofoils. In the interaction, a strong electrostatic potential develops between the two foils, which drags electrons out of the second foil and piles them up in vacuum, forming an ultradense relativistic electron nanobunch. This nanobunch reaches both high density and high energy in only half a laser cycle and smears out in others, resulting in coherent synchrotron emission of a single, intense attosecond pulse. Such a pulse enables the capture and control of electron motion at the picometer–attosecond scale.
To explore the effects and mechanisms of tetraspanin TSPAN7 on the progression of non-small-cell lung cancer (NSCLC) cells.
All 125 lung cancer specimens and 60 metastatic tissues were obtained from ...patients diagnosed with NSCLC, and we used immunohistochemistry to detect the expression of TSPAN7 in NSCLC tissues and adjacent normal tissues. Cell proliferation and invasion ability were determined by MTT, colony formation, and cell migration. The relative protein expression level was analyzed by Western blot analysis.
Our clinical data showed that among 125 patients with lung cancer, TSPAN7 was associated with lymph node status, differentiation, tumor size, and poor prognosis. TSPAN7 knockout inhibited cell proliferation and migration. In addition, TSPAN7 increased the expression of N-cadherin in NSCLC cells by reducing the expression of E-cadherin and vimentin and promoting the cell epithelial-mesenchymal transition (EMT) process. Xenograft transplantation model confirmed the role of TSPAN7 in NSCLC metastasis.
TSPAN7-mediated EMT is the key to NSCLC migration. TSPAN7 is a potential target for NSCLC therapy.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Seed sets are of significant importance to trust propagation based anti-spam algorithms, e.g., TrustRank. Conventional approaches require manual evaluation to construct a seed set, which restricts ...the seed set to be small in size, since it would cost too much and may even be impossible to construct a very large seed set manually. The detrimental effect will be caused to the final ranking results by the small-sized seed sets. Thus, it is desirable to automatically expand an initial seed set to a larger one. In this paper, we propose an automatic seed set expansion algorithm (ASE) which enriches a small seed set to a much larger one. The intuition behind ASE is that if a page is recommended by a number of trustworthy pages, the page itself should be trustworthy as well. Since links on the Web can be considered as a tool for conveying recommendation, we call links recommending the same page a joint recommendation link structure. The joint recommendation link structures with large enough support degrees are employed by ASE algorithm to obtain new seeds. It can be proved that using the joint recommendation link structure with a suitable support degree, the probability of selecting a spam page as a new seed almost to zero, thus the quality of the expanded seed set can be guaranteed. Experimental results on the WEBSPAM-UK2007 dataset show that with the same manual evaluation efforts, ASE can automatically obtain a lot of reputable seeds with very high quality, and significantly improves the performance of trust propagation based algorithms such as TrustRank and CPV (Computing Page Values).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The origin of the cosmic magnetic field remains an unsolved mystery, relying not only on specific dynamo processes but also on the seed field to be amplified. Recently, the diffuse radio emission and ...Faraday rotation observations reveal that there has been a microgauss-level magnetic field in intracluster medium in the early universe, which places strong constraints on the strength of the initial field and implies the underlying kinetic effects; the commonly believed Biermann battery can only provide extremely weak seed of 10
G. Here, we present evidence for the spontaneous Weibel-type magnetogenesis in laser-produced weakly collisional plasma with the three-dimensional synchronous proton radiography, where the distribution anisotropy directly arises from the temperature gradient, even without the commonly considered interpenetrating plasmas or shear flows. This field can achieve sufficient strength and is sensitive to Coulomb collision. Our results demonstrate the importance of kinetics in magnetogenesis in weakly collisional astrophysical scenarios.
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