The Fixed Points of Solutions of Some q

The purpose of this paper is to investigate the fixed points of solutions f(z) of some q-difference equations and obtain some results about the exponents of convergence of fixed points of f(z) and f(qjz)  (j∈N+), q-differences Δqf(z)=f(qz)-f(z), and q-divided differences Δqf(z)/f(z)

Optimization of a fed-batch bioreactor for 1,3-propanediol production using hybrid nonlinear optimal control

A nonlinear hybrid system was proposed to describe the fed-batch bioconversion of glycerol to 1,3-propanediol with substrate open loop inputs and pH logic control in previous work [47]. The current work concerns the optimal control of this fed-batch process. We slightly modify the hybrid system to provide a more convenient mathematical description for the optimal control of the fed-batch culture. Taking the feeding instants and the terminal time as decision variables, we formulate an optimal control model with the productivity of 1,3-propanediol as the performance index. Inequality path constraints involved in the optimal control problem are transformed into a group of end-point constraints by introducing an auxiliary hybrid system. The original optimal control problem is associated with a family of approximation problems. The gradients of the cost functional and the end-point constraint functions are derived from the parametric sensitivity system. On this basis, we construct a gradient-based algorithm to solve the approximation problems. Numerical results show that the productivity of 1,3-propanediol can be increased considerably by employing our optimal control policy

Quantitative relationship between synonymous codon usage bias and GC composition across unicellular genomes

BACKGROUND: Codon usage bias has been widely reported to correlate with GC composition. However, the quantitative relationship between codon usage bias and GC composition across species has not been reported. RESULTS: Based on an informatics method (SCUO) we developed previously using Shannon informational theory and maximum entropy theory, we investigated the quantitative relationship between codon usage bias and GC composition. The regression based on 70 bacterial and 16 archaeal genomes showed that in bacteria, SCUO = -2.06 * GC3 + 2.05*(GC3)(2 )+ 0.65, r = 0.91, and that in archaea, SCUO = -1.79 * GC3 + 1.85*(GC3)(2 )+ 0.56, r = 0.89. We developed an analytical model to quantify synonymous codon usage bias by GC compositions based on SCUO. The parameters within this model were inferred by inspecting the relationship between codon usage bias and GC composition across 70 bacterial and 16 archaeal genomes. We further simplified this relationship using only GC3. This simple model was supported by computational simulation. CONCLUSIONS: The synonymous codon usage bias could be simply expressed as 1+ (p/2)log(2)(p/2) + ((1-p)/2)log(2)((l-p)/2), where p = GC3. The software we developed for measuring SCUO (codonO) is available at

Grain boundary ferromagnetism in vanadium-doped In2_2O3_3 thin films

Room temperature ferromagnetism was observed in In$_2$O$_3 thin films doped with 5 at.temperatures ranging from 300 to 600$\,^{\circ}{\rm C}$. X-ray absorption fine structure measurement indicated that vanadium was substitutionally dissolved in the In$_2$O$_3$ host lattice, thus excluding the existence of secondary phases of vanadium compounds. Magnetic measurements based on SQUID magnetometry and magnetic circular dichroism confirm that the magnetism is at grain boundaries and also in the grains. The overall magnetization originates from the competing effects between grains and grain boundaries.Comment: 12 pages, 7 figures, 1 table, accepted by Europhysics Letter

1-Benzoyl-3,6-diphenyl-1,4-dihydro-1,2,4,5-tetra­zine

In the title compound, C21H16N4O, the central tetra­zine ring adopts an unsymmetrical boat conformation with the two N atoms as the bow and stern. The crystal packing is stabilized by inter­molecular N—H—O hydrogen bonds

MiR-145 inhibits proliferation of primary colon adenocarcinoma cells via induction of apoptosis, cell cycle arrest and inhibition of cell migration

Purpose: To investigate the role and potential of miR-145 as a therapeutic target for the treatment of primary colon adenocarcinoma in cell linesMethods: The expression of miR145 was determined by quantitative real time-polymerase chain reaction (RT-PCR), while cell viability was determined by MTT assay. Apoptosis was assessed by 4',6-diamidino-2-phenylindole (DAPI), acridine orange/ethidium bromide (AO/EB), and annexin V/PI doublestaining. Cell cycle analysis was performed by flow cytometry, while immunoblotting was used to determine protein expression.Results: The expression of miR-145 was significantly enhanced in all the colon adenocarcinoma cell lines investigated. On the other hand, suppression of miR-145 expression led to significant decrease in cell viability, activation of apoptosis, G2/M cell cycle arrest, and inhibition of migration of colon adenocarcinoma cells.Conclusion: These results indicate that miR-145 regulates the proliferation and metastasis of colon adenocarcinoma cells. Thus, it may be a prospective drug target for the treatment of this disease.Keywords: MicroRNA, Apoptosis, Cell migration, Proliferatio

An analytic derivation of the empirical correlations of gamma-ray bursts

Empirical correlations between various key parameters have been extensively explored ever since the discovery of gamma-ray bursts (GRBs) and have been widely used as standard candles to probe the Universe. The Amati relation and the Yonetoku relation are two good examples, which have been paid special attention to. The former reflects the connection between the peak photon energy (Ep) and the isotropic $\gamma$-ray energy release (Eiso), while the latter links Ep with the isotropic peak luminosity (Lp), both in the form of a power law function. Most GRBs are found to well follow these correlations, but a theoretical interpretation is still lacking. Meanwhile, there are also some obvious outliers, which may be off-axis GRBs and may follow different correlations as compared with the on-axis ones. Here we present a simple analytical derivation for the Amati relation and the Yonetoku relation in the framework of the standard fireball model, the correctness of which are then confirmed by numerical simulations. The off-axis Amati relation and Yonetoku relation are also derived, which differ from the corresponding on-axis relation markedly. Our results reveal the intrinsic physics lying behind the radiation processes of GRBs, and highlight the importance of viewing angle in the empirical correlations of GRBs.Comment: 20 pages, 7 figures, 2 tables. Submitted to A&

Recombinant immunotoxin anti-c-Met/PE38KDEL inhibits proliferation and promotes apoptosis of gastric cancer cells

<p>Abstract</p> <p>Background</p> <p>Our study aims to evaluate the anti-growth effects of recombinant immunotoxin (IT) anti-c-Met/PE38KDEL on gastric cancer cells, and its mechnisms.</p> <p>Methods</p> <p>Gastric cancer cells were treated with increasing doses of IT and c-Met protein was quantified by Western blotting. Cell proliferation was determined by Cell Counting Kit-8 assay (CCK). [³H]-leucine incorporation assay was used to evaluate IT inhibition of protein synthesis. Cell apoptosis was quantified by flow cytometry. Caspase activities were measured using colorimetric protease assays.</p> <p>Results</p> <p>Cell growth and protein synthesis of the gastric cancer cell lines were suppressed by IT in a dose- and time-dependent manner. IT also induced apoptosis in a dose-dependent manner. The apoptosis rates of gastric cancer cell lines MKN-45 and SGC7901 were 19.19% and 27.37%, respectively when treated with 50 ng/ml of IT. There were significant increase ofcaspase-3 activity at 24 hr of IT treatment (100 ng/ml) (P < 0.01) in these gastric cancer cell lines.</p> <p>Conclusions</p> <p>IT anti-c-Met/PE38KDEL has anti-growth effects on the gastric cancer cell lines <it>in vitro</it>, and it provides an experimental basis for c-Met-targeted therapy towards <it>in vivo </it>testing.</p

Re-mine, Learn and Reason: Exploring the Cross-modal Semantic Correlations for Language-guided HOI detection

Human-Object Interaction (HOI) detection is a challenging computer vision task that requires visual models to address the complex interactive relationship between humans and objects and predict HOI triplets. Despite the challenges posed by the numerous interaction combinations, they also offer opportunities for multimodal learning of visual texts. In this paper, we present a systematic and unified framework (RmLR) that enhances HOI detection by incorporating structured text knowledge. Firstly, we qualitatively and quantitatively analyze the loss of interaction information in the two-stage HOI detector and propose a re-mining strategy to generate more comprehensive visual representation.Secondly, we design more fine-grained sentence- and word-level alignment and knowledge transfer strategies to effectively address the many-to-many matching problem between multiple interactions and multiple texts.These strategies alleviate the matching confusion problem that arises when multiple interactions occur simultaneously, thereby improving the effectiveness of the alignment process. Finally, HOI reasoning by visual features augmented with textual knowledge substantially improves the understanding of interactions. Experimental results illustrate the effectiveness of our approach, where state-of-the-art performance is achieved on public benchmarks. We further analyze the effects of different components of our approach to provide insights into its efficacy.Comment: ICCV202

Variational-based data assimilation to simulate sediment concentration in the Lower Yellow River, China

The heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available