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The pansharpening method based on spatial injection is prone to spectral distortion due to the spatial detail injection amount mismatch. For this reason, this paper proposes a method that combines adaptive intensity component extraction and spatial detail injection optimisation. Firstly, a new method for extracting the I component of multispectral (MS) image is proposed, which decomposes each band of MS image and panchromatic (PAN) image according to the structure-energy mechanism through the joint bilateral filter and then determines the weight coefficient of each band of MS image to extract the I component by solving the minimum optimisation problem of the structure layer of PAN image and the energy layer of MS image. Secondly, a spatial detail extraction method combining local spatial frequency and local energy is proposed, and the method can fully extract the fine detail features of PAN images and MS images. In this paper, many experiments are conducted on QuickBird, GeoEye-1 and WorldView-4 datasets, and quantitative and qualitative comparisons are made with eight advanced methods, and qualitative and quantitative analyses of the experimental results show that the proposed method has certain superiority. [ABSTRACT FROM AUTHOR]

Spatial injection-based pansharpening methods are prone to spatial or spectral distortions in pansharpening images due to insufficient extraction of spatial details and a mismatch between the amount of spatial detail information injected and the required amount. To this end, this paper proposes a pansharpening method that optimizes spatial detail extraction and injection. Firstly, a method to optimize the amount of spatial detail injection is proposed, that is, to extract the high-frequency information of the image through iterative filtering and determine the optimal number of iterations based on the global analysis of the method. Then, to fully extract and combine the spatial detail information of the source image, the detailed high-frequency image extracted corresponding to the optimal iterative filtering times is decomposed by non-subsampled shearlet transform (NSST), and a new multi-scale sum-modified-Laplacian (NSML) as an external stimulus to a parameter-adaptive pulse-coupled neural network model (PAPCNN). A fusion rule based on multi-scale morphological gradients is designed to extract a small amount of detailed information for the low-frequency subband. The fused spatial detail image can be obtained by combining the fused low-frequency and high-frequency subbands and inverse NSST transformation. Finally, pansharpening can be realized by combining spatial detail image, injection coefficient, and MS image. In this paper, many experiments are carried out on the QuickBird, GeoEye-1, and WorldView-4 datasets, and quantitative and qualitative comparisons are made with eight advanced methods. Experimental results show that the method proposed in this paper can achieve better fusion results. [ABSTRACT FROM AUTHOR]

A permutation is happy, if it can be transformed into the identity permutation using as many short swaps as one third times the number of inversions in the permutation. The complexity of the decision version of sorting a permutation by short swaps, is still open. We present an O(n) time algorithm to decide whether it is true for a permutation to be happy, where n is the number of elements in the permutation. If a permutation is happy, we give an O (n 2) time algorithm to find a sequence of as many short swaps as one third times the number of its inversions, to transform it into the identity permutation. A permutation is lucky, if it can be transformed into the identity permutation using as many short swaps as one fourth times the length sum of the permutation's element vectors. We present an O(n) time algorithm to decide whether it is true for a permutation to be lucky, where n is the number of elements in the permutation. If a permutation is lucky, we give an O (n 2) time algorithm to find a sequence of as many short swaps as one fourth times the length sum of its element vectors to transform it into the identity permutation. This improves upon the O (n 2) time algorithm proposed by Heath and Vergara to decide whether a permutation is lucky. We show that there are at least 2 ⌈ n 2 ⌉ - 2 happy permutations as well as 2 n - 4 lucky permutations of n elements. [ABSTRACT FROM AUTHOR]

In this paper, we propose an algorithm which approximates the Two-Sided Scaffold Filling problem to a performance ratio 1.4 + ε. This is achieved through a deep investigation of the optimal solution structure of Two-Sided Scaffold Filling. We make use of a relevant graph aiming at a solution of a Two-Sided Scaffold Filling instance, and evaluate the optimal solution value by the number of connected components in this graph. We show that an arbitrary optimal solution can be transformed into one whose relevant graph admits connected components that are available to compare with the solution of our algorithm in terms of their values. The performance ratio 1.4 + ε is obtained by comparing the bound of such an optimal solution with the solution of our algorithm. [ABSTRACT FROM AUTHOR]

In this paper, we study the Maximum Internal Spanning Tree Problem (MIST). Given an undirected simple graph G , the task for the Maximum Internal Spanning Tree problem is to find a spanning tree of G with maximum number of internal vertices. We present an approximation algorithm with performance ratio 4 3 , which improves upon the best known performance ratio 3 2. Our algorithm benefits from a new observation for bounding the number of internal vertices of a spanning tree. We can also give an example to show that the performance ratio 4 3 is actually tight for this algorithm. Finally, we show that MIST is Max-SNP-hard. [ABSTRACT FROM AUTHOR]

Translocation has been long learned as a basic operation to rearrange the structure of a genome. Translocation sorting asks to find a shortest sequence of translocations that transforms one genome into another, which has attracted attention of many scientists in algorithm design. Signed translocation sorting can be solved in polynomial time. Unsigned translocation sorting turns out to be NP-Hard and Max-SNP-Hard. The best known approximation algorithm by now for unsigned translocation sorting can achieve a performance ratio 1.408. In this paper, we propose a new approximation algorithm for unsigned translocation sorting which can achieve a asymptotic performance ratio 1.375. [ABSTRACT FROM AUTHOR]

Environmentally-friendly carbon-based materials possess the potential applications as general anode for alkali-ion batteries. However, the existing carbon-based materials cannot satisfy the increasing demand for high energy density and need further active exploration. Herein, nitrogen/oxygen co-doped graphene-like carbon nanocages (NOGCN) is synthesized from biomass cytidine on hydro-soluble sodium chloride nanocrystals by a one-step method as a general lithium and potassium-ion batteries anode. All reactants are completely renewable and readily available. The nitrogen/oxygen-doping, large interlayer spacing and robust self-supporting nanocage architecture greatly favour electrolyte penetration and improve the kinetics for ion and electron transport, resulting in extraordinary electrochemical performance. The synthesized NOGCN electrodes exhibit a high lithiation storage capacity of 620 mA h g−1 over 500 cycles at 500 mA g−1, with continuously magnifying capacity. Moreover, the impressive reversible potassiation capacity (355 mA h g−1 at 200 mA g−1) and rate capability (114 mA h g−1 at 1000 mA g−1) were achieved despite the large-sized potassium ions. Kinetic analysis and density functional theory calculations elaborately illustrate the Li/K-absorption properties of the N/O-doped graphene-like structure, further demonstrating the chemical affinity and superiority in Li/K storage. This study provides a facile and completely renewable method to prepare promising general anode material for alkali-ion batteries. Image 1 [ABSTRACT FROM AUTHOR]

Copy number variation (CNV) is a prevalent kind of genetic structural variation which leads to an abnormal number of copies of large genomic regions, such as gain or loss of DNA segments larger than 1 kb. CNV exists not only in human genome but also in plant genome. Current researches have testified that CNV is associated with many complex diseases. In this paper, guanine-cytosine (GC) bias, mappability and their effect on read depth signals in sequencing data are discussed first. Subsequently, a new correction method for GC bias and an improved combinatorial detection algorithm for CNV using high-throughput sequencing reads based on hidden Markov model (CNV-HMM) are proposed. The corrected read depth signals have lower correlation with GC content, mappability of reads and the width of analysis window. Then we create a hidden Markov model which maps the reads onto the reference genome and records the unmapped reads. The unmapped reads are counted and normalized. The CNV-HMM detects the abnormal signal of read count and gains the candidate CNVs using the expectation maximization (EM) algorithm. Finally, we filter the candidate CNVs using split reads to promote the performance of our algorithm. The experiment result indicates that the CNV-HMM algorithm has higher accuracy and sensitivity for CNVs detection than most current detection algorithms. [ABSTRACT FROM AUTHOR]

The prediction of RNA structure with pseudoknots is a nondeterministic polynomial-time hard (NP-hard) problem; according to minimum free energy models and computational methods, we investigate the RNA-pseudoknotted structure. Our paper presents an efficient algorithm for predicting RNA structure with pseudoknots, and the algorithm takes O(n3) time and O(n2) space, the experimental tests in Rfam10.1 and PseudoBase indicate that the algorithm is more effective and precise. The predicting accuracy, the time complexity and space complexity outperform existing algorithms, such as Maximum Weight Matching (MWM) algorithm, PKNOTS algorithm and Inner Limiting Layer (ILM) algorithm, and the algorithm can predict arbitrary pseudoknots. And there exists a 1+ε (ε>0) polynomial time approximation scheme in searching maximum number of stackings, and we give the proof of the approximation scheme in RNA-pseudoknotted structure. We have improved several types of pseudoknots considered in RNA folding structure, and analyze their possible transitions between types of pseudoknots. [ABSTRACT FROM AUTHOR]

Background: Database search has been the main approach for proteoform identification by top-down tandem mass spectrometry. However, when the target proteoform that produced the spectrum contains post-translational modifications (PTMs) and/or mutations, it is quite time consuming to align a query spectrum against all protein sequences without any PTMs and mutations in a large database. Consequently, it is essential to develop efficient and sensitive filtering algorithms for speeding up database search. Results: In this paper, we propose a spectrum graph matching (SGM) based protein sequence filtering method for top-down mass spectral identification. It uses the subspectra of a query spectrum to generate spectrum graphs and searches them against a protein database to report the best candidates. As the sequence tag and gaped tag approaches need the preprocessing step to extract and select tags, the SGM filtering method circumvents this preprocessing step, thus simplifying data processing. We evaluated the filtration efficiency of the SGM filtering method with various parameter settings on an Escherichia coli top-down mass spectrometry data set and compared the performances of the SGM filtering method and two tag-based filtering methods on a data set of MCF-7 cells. Conclusions: Experimental results on the data sets show that the SGM filtering method achieves high sensitivity in protein sequence filtration. When coupled with a spectral alignment algorithm, the SGM filtering method significantly increases the number of identified proteoform spectrum-matches compared with the tag-based methods in top-down mass spectrometry data analysis. [ABSTRACT FROM AUTHOR]

The metal-free synthesis of graphene on single-crystal silicon substrates, the most common commercial semiconductor, is of paramount significance for many technological applications. In this work, we report the growth of graphene directly on an upside-down placed, single-crystal silicon substrate using metal-free, ambient-pressure chemical vapor deposition. By controlling the growth temperature, in-plane propagation, edge-propagation, and core-propagation, the process of graphene growth on silicon can be identified. This process produces atomically flat monolayer or bilayer graphene domains, concave bilayer graphene domains, and bulging few-layer graphene domains. This work would be a significant step toward the synthesis of large-area and layer-controlled, high-quality graphene on single-crystal silicon substrates. [ABSTRACT FROM AUTHOR]

Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in infected mosquitoes, is a lead transmission-blocking vaccine candidate against falciparum malaria. To enhance immunogenicity, recombinant Pfs25 was chemically conjugated to recombinant nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA) in conformance with current good manufacturing practices (cGMP), and formulated with the alum adjuvant Alhydrogel. In order to meet the regulatory requirements for a phase 1 human clinical trial, the vaccine product was extensively evaluated for stability at an initial time point and through the clinical trial period annually. Because basic quality control methods to characterize alum-based vaccines remain unavailable, a thermal forced degradation study was performed prior to the initial evaluation to identify the methods suitable to detect the quality of vaccine formulations. Our results show that the vaccine product Pfs25-EPA formulated on Alhydrogel is in conformance with regulatory guidelines and suitable for human trials. [ABSTRACT FROM AUTHOR]

In order to run a dataflow with as low cost as possible, it is often faced with deciding which data-sets in a data-set sequence should be stored, with the rest regenerated. The Intermediate Data-set Storage problem arises from this situation. The current best algorithm for this problem takes O ( n 4 ) time. In this paper, we present two improved algorithms for this problem, the first of which can achieve a time complexity O ( n 2 ) , the second of which O ( r n ) , where n is the number of data-sets in a dataflow, r is a numerical number which indicates how large it is for the maximum storage cost to be divided by the minimum computation cost in the dataflow. [ABSTRACT FROM AUTHOR]

The scaffold filling problem aims to set up the whole genomes by filling those missing genes into the scaffolds to optimize a similarity measure of genomes. A typical and frequently used measure for the similarity of two genomes is the number of common adjacencies. One-sided scaffold filling is given by a scaffold and a whole genome, and asks to fill the missing genes into that scaffold to result in such a genome that the number of common adjacencies between it and the given genome is maximized. Two-sided scaffold filling is given by two scaffolds, and asks to fill the missing genes into those two scaffolds respectively to result in such two genomes that the number of common adjacencies between them is maximized. One-sided scaffold filling can be approximated to $$\frac{5}{4}$$ by now. However, the algorithmic progress for two-sided scaffold filling seems rare. What we know for two-sided scaffold filling is a 2-approximation algorithm by now. In this paper, we propose a new algorithm for two-sided scaffold filling which can achieve a performance ratio of $$\frac{3}{2}$$ in $$O(N^3)$$ time, where $$N$$ is the number of genes in an output genome. An example can be given to show that the performance ratio $$\frac{3}{2}$$ for this algorithm is actually tight. [ABSTRACT FROM AUTHOR]

In-situ two-dimensional grazing incidence X-ray diffraction was applied in isothermal growth of graphene on nickel through chemical vapor deposition. The analyses showed that the graphene interlayer spacing decreases with the increasing number of graphene layers (growth time increase). Moreover, the as-deposited graphene can be gradually removed through in-situ Ar annealing treatment and inverse interlayer spacing change was also observed, i.e., the interlayer spacing of graphene increases with the number of graphene layers decrease. These results prove that there is a strong coupling effect between the interlayer spacing and the number of graphene layers. The weak interlayer interactions between graphene layers and the interface effects may contribute to this phenomenon. [ABSTRACT FROM AUTHOR]

The exemplar breakpoint distance problem is motivated by finding conserved sets of genes between two genomes. It asks to find respective exemplars in two genomes to minimize the breakpoint distance between them. If one genome has no repeated gene (called trivial genome) and the other has genes repeating at most twice, it is referred to as the (1, 2)-exemplar breakpoint distance problem, EBD(1, 2) for short. Little has been done on algorithm design for this problem by now. In this article, we propose a parameter to describe the maximum physical span between two copies of a gene in a genome, and based on it, design a fixed-parameter algorithm for EBD(1, 2). Using a dynamic programming approach, our algorithm can take O(4 s n2) time and O(4 s n) space to solve an EBD(1, 2) instance that has two genomes of n genes where the second genome has each two copies of a gene spanning at most s copies of the genes. Our algorithm can also be used to compute the maximum adjacencies between two genomes. The algorithm has been implemented in C++. Simulations on randomly generated data have verified the effectiveness of our algorithm. The software package is available from the authors. [ABSTRACT FROM AUTHOR]

Abstract: Elections are an important preference aggregation model in a variety of areas. Given a pool of n potential voters, the chair may strategically selecting k voters from the pool to feed to an election system, in order to control the final outcome of the election system. This type of control, called control by voter selection, is closely related to two already well-studied types of control, i.e., control by voter addition and control by voter deletion. This paper studies parameterized complexity of control by voter selection for five election systems, i.e., Maximin, ( ), Borda, Bucklin, and Approval. We prove that constructive/destructive control of Maximin, constructive/destructive control of , constructive control of Borda, constructive control of Bucklin, and constructive control of Approval are all W[2]-hard, with respect to the parameter “number of selected voters”. [Copyright &y& Elsevier]

Abstract: Translocation is a prevalent rearrangement event in the evolution of multi-chromosomal species which exchanges ends between two chromosomes. A translocation is reciprocal if none of the exchanged ends is empty; otherwise, non-reciprocal. The problem of sorting by translocations asks to find a shortest sequence of translocations transforming one genome into another. The problem of sorting by reciprocal translocations can be solved in polynomial-time. Several algorithms have been developed for reciprocal translocation sorting. They can only be applied to a pair of genomes having the same set of chromosome ends. Such a restriction can be removed if non-reciprocal translocations are also allowed. In this paper, we show how to extend the algorithm for sorting by reciprocal translocations to include non-reciprocal translocations, allowing us to compare genomes containing different chromosome ends. We call this problem sorting by generalized translocations. We present a polynomial algorithm for this problem. At a conceptual level, there is some similarity between our algorithm and the algorithm developed by Hannenhalli which is used to sort genomes by reversals and translocations. [Copyright &y& Elsevier]

Abstract: The present study reports a method to determine the total protein concentration or concentration of a protein of interest in a protein–protein conjugate using ultraviolet absorption, after determining the molar ratio of proteins in the conjugates, from which an extinction coefficient can be calculated. A Microsoft Excel solver-based template using amino acid analysis data was developed for determining the molar ratio. The percent mass of each protein in the conjugate is calculated from the amino acid composition data using the least squares method in the Microsoft Excel solver function, and the percent mass is converted to molar portion of each protein using corresponding molecular weight. A molar ratio is obtained by dividing the molar portion of protein 1 by the molar portion of protein 2. A weighted extinction coefficient is calculated using the molar ratio, and the total protein concentration is determined using ultraviolet absorption at 280nm. The accuracy of the method was verified using mixtures of known proteins. The present study provides a rapid, simple and accurate method for determining protein concentration in protein–protein conjugates. [Copyright &y& Elsevier]

Abstract: A cut-and-paste operation can be a reversal, a transposition, or a transreversal on circular or linear permutations. There are several approximation algorithms for sorting signed permutations by combinations of these operations. For sorting unsigned permutations, we only know an algorithm with performance ratio 3 and its improved version with performance ratio allowing reversals and transpositions. In this paper, we present a 2.25-approximation algorithm for sorting unsigned circular permutations by cut-and-paste operations. A structure called tie is proposed to represent the alternating path of length 5. We can classify the ties into 6 types and find ways to remove the breakpoints for each type of ties, so that every cut-and-paste operation can reduce at least breakpoints averagely. Our algorithm can be used to sort unsigned linear permutations and achieve the performance ratio 2.25 if another operation named revrev is allowed. [Copyright &y& Elsevier]

Abstract: Sorting permutations by operations such as reversals and block-moves has received much attention because of its applications in the study of genome rearrangements. A short block-move is an operation on a permutation that moves an element at most two positions away from its original position. In this paper, we investigate the problem of finding a minimum-length sorting sequence of short block-moves for a given permutation, and devise a ()-approximation algorithm for this problem, where is the number of elements divided by the number of inversions in the permutation. The algorithm mostly relies on a new structure in the permutation graph called an umbrella, which can be optimally sorted in time. [Copyright &y& Elsevier]

Abstract: Given a graph with nonnegative costs defined on edges, a positive integer , and a collection of terminal sets , where each is a subset of , the Generalized -Multicut problem asks to find a set of edges at the minimum cost such that its removal from cuts at least terminal sets in . A terminal subset is cut by if all terminals in are disconnected from one another by removing from . This problem is a generalization of the -Multicut problem and the Multiway Cut problem. The famous Densest -Subgraph problem can be reduced to the Generalized -Multicut problem in trees via an approximation preserving reduction. In this paper, we first give an -approximation algorithm for the Generalized -Multicut problem when the input graph is a tree. The algorithm is based on a mixed strategy of LP-rounding and greedy approach. Moreover, the algorithm is applicable to deal with a class of NP-hard partial optimization problems. As its extensions, we then show that the algorithm can be used to give -approximation for the Generalized -Multicut problem in undirected graphs and -approximation for the -Forest problem. [Copyright &y& Elsevier]

Abstract: Efficient antigen extraction from vaccines formulated on aluminum hydroxide gels is a critical step for the evaluation of the quality of vaccines following formulation. It has been shown in our laboratory that the efficiency of antigen extraction from vaccines formulated on Alhydrogel decreased significantly with increased storage time. To increase antigen extraction efficiency, the present study determined the effect of surfactants on antigen recovery from vaccine formulations. The Plasmodium falciparum apical membrane antigen 1 (AMA1) formulated on Alhydrogel and stored at 2–8°C for 3 years was used as a model in this study. The AMA1 on Alhydrogel was extracted in the presence or absence of 30mM sodium dodecyl sulfate (SDS) or 20mM cetylpyridinium chloride in the extraction buffer (0.60M citrate, 0.55M phosphate, pH 8.5) using our standard antigen extraction protocols. Extracted AMA1 antigen was analyzed by 4–20% Tris–glycine SDS-PAGE followed by silver staining or western blotting. The results showed that inclusion of SDS or cetylpyridinium chloride in extraction buffer increased the antigen recovery dramatically and can be used for efficient characterization of Alhydrogel vaccines. [Copyright &y& Elsevier]

Abstract: Plasmodium falciparum apical membrane antigen 1 (AMA1) is an asexual blood-stage vaccine candidate against the malaria parasite. AMA1-C1/ISA720 refers to a mixture of recombinant AMA1 proteins representing the FVO and 3D7 alleles in 1:1 mass ratio, formulated with Montanide® ISA 720 as a water-in oil emulsion. In order to develop the AMA1-C1/ISA720 vaccine for human use, it was important to determine the shelf life of this formulation. Previously it was found 267mM glycine stabilized the proteins in Montanide® ISA 720 formulations for a short period of time at 2–8°C . We now test the long term stability of AMA1-C1 at 10 and 40μg/mL formulated with Montanide® ISA 720 with 50mM glycine as a stabilizer. Stability of AMA1-C1/ISA720 at different time points following formulation (0, 5, 12 or 18 months) was evaluated by determining the mean particle size (diameter of the mean droplet volume), total protein content by a Modified Lowry assay, identity and integrity using western blot and SDS–PAGE. Our results showed that the mean particle size of these emulsions increased over time, whereas protein content, as determined by an ELISA method using a monoclonal antibody against penta-his, decreased over time. For the 10μg/mL AMA1-C1/ISA720 vaccine, the protein content was 6.5±2.2μg/mL, and for the 40μg/mL AMA1-C1/ISA720 vaccine, the protein content was only 8.2±2.3μg/mL after 18 months of storage at 2–8°C. These results suggest that the integrity of the protein was affected by long-term storage. The results of the present study indicate that the AMA1-C1/ISA720 emulsion was unstable after 12 months of storage, after which AMA1-C1 proteins were partially degraded. [Copyright &y& Elsevier]

Abstract: Aluminum based adjuvants (alum), including aluminum hydroxide (Alhydrogel®) and aluminum phosphate are the most commonly used adjuvant in the US. In order to ensure quality of vaccines, regulatory authorities require evaluation of antigen content in final vaccine products. Currently, there are no generic methods available for the determination of protein content in alum-based vaccines. Aluminum hydroxide gels exist as particles in solution, which interfere with direct quantitation of protein content in formulations using assays such as Lowry, BCA or Bradford protein assay. The present study adapts a simple fluorescent assay to directly (without the need for antigen extraction) determine antigen content on Alhydrogel® with accuracy and sensitivity using the o-phthalaldehyde (OPA) reagent. Malaria vaccine candidates AMA1-C1/Alhydrogel, AMA1-C2/Alhydrogel, MSP142-3D7/Alhydrogel, MSP142-C1/Alhydrogel or BSAM-2/Alhydrogel were used as model formulations. The results of the present study show that the OPA assay is highly accurate (87–100%), reproducible, and simple with a linear detection range of 25–400μg/mL for Alhydrogel® vaccines (except for MSP142-C1, which has a linear detection range of 31.25–500μg/mL). This assay has proven to be highly useful in our laboratory and been used in routine vaccine quality control processes. [Copyright &y& Elsevier]

Abstract: Alhydrogel® (aluminum hydroxide) is a widely used adjuvant in the US. Regulatory authorities require that vaccines be tested to determine the antigen content in the final vaccine product. The level of formulated antigen is currently determined in our laboratory by the o-Phthalaldehyde (OPA) fluorescent protein assay, and antigen identity and integrity are determined by Western blot and SDS–PAGE. However, OPA assay is non-specific and only limited to detection of total protein content, and it is often not sensitive enough to detect antigens in low dose formulations. Furthermore, antigens used in identity and integrity tests must be extracted from vaccines using an extraction procedure which is time-consuming and may not completely recover antigens for analysis or may alter the structures of antigens during extraction. The present study developed a Direct Alum Formulation Immunoassay (DAFIA) which was designed to directly (without antigen extraction), accurately, and sensitively determine the antigen content, identity and integrity on alum. The AMA1-C1/Alhydrogel formulation was used as a model vaccine in assay development and validation. The results showed that the DAFIA is highly antigen-specific, accurate (87–100%), sensitive (0.16 µg/ml), reproducible, and simple with a linear detection range of 0.16–10 µg/ml. These results demonstrate that DAFIA is an excellent assay to determine antigen content, identity and integrity of antigens bound to alum and may be used in routine vaccine quality control for testing antigens in Alhydrogel-based vaccines. [Copyright &y& Elsevier]

Abstract: In this paper, we focus on the directed minimum degree spanning tree problem and the minimum time broadcast problem. Firstly, we propose a polynomial time algorithm for the minimum degree spanning tree problem in directed acyclic graphs. The algorithm starts with an arbitrary spanning tree, and iteratively reduces the number of vertices of maximum degree. We can prove that the algorithm must reduce a vertex of the maximum degree for each phase, and finally result in an optimal tree. The algorithm terminates in time, where m and n are the numbers of edges and vertices of the graph, respectively. Moreover, we apply the new algorithm to the minimum time broadcast problem. Two consequences for directed acyclic graphs are: (1) the problem under the vertex-disjoint paths mode can be approximated within a factor of of the optimum in -time; (2) the problem under the edge-disjoint paths mode can be approximated within a factor of of the optimum in -time, where is the minimum k such that there is a spanning tree of the graph with maximum degree k. [Copyright &y& Elsevier]

Abstract: Translocation is one of the basic operations for genome rearrangement. Translocation distance is the minimum number of translocations required to transform one genome into the other. In this paper, we show that computing the translocation distance for unsigned genomes is NP-hard. Moreover, we show that approximating the translocation distance for unsigned genomes within ratio 1.00017 is NP-hard. [Copyright &y& Elsevier]

Abstract: Residual host cell protein impurities in recombinant proteins intended for human use must be accurately quantified to help establish their safety. We describe a novel means of host cell protein quantitation, in which a slot blot system was employed together with scanning laser densitometry to allow picogram level sensitivity in detection of residual host cell proteins in unpurified fermentation products and final purified bulk samples. Two allelic forms of merozoite surface protein 1, a promising malaria vaccine candidate antigen currently undergoing evaluation in clinical trials, were expressed in E. coli as clinical grade proteins, refolded, and carried through several chromatographic purification steps. Several lots of these proteins were analyzed with this generic quantitative assay that uses rat polyclonal antibodies generated against soluble and insoluble E. coli proteins. The assay had a detection range of 6.1–1562 ng/mL, with a detection limit of 6.1 ng/mL, comparable to reported ELISA-based methods. This assay proved simple yet very sensitive and accurate, giving highly reproducible results. Thus it is suitable for evaluating host cell protein levels in clinical grade recombinant proteins expressed in E. coli. [Copyright &y& Elsevier]

Abstract: Genome rearrangement is an important area in computational biology. There are three basic operations, reversal, translocation and transposition. Here we study the translocation operations. Multi-chromosomal genomes frequently evolve by translocation events that exchange genetic material between two chromosomes. We focus on the signed case, where the direction of each gene is known. The signed translocation problem asks to find the minimum number of translocation operations as well as the sequence of translocation operations to transform one genome into the other. A linear-time algorithm that computes the minimum number of translocation operations was given in a linear-time algorithm for computing translocation distance between signed genomes [16]. However, that algorithm cannot give the optimum sequence of translocation operations. The best known algorithm that can give the optimum sequence of translocation operations for signed translocation problem runs in time. In this paper, we design an algorithm. [Copyright &y& Elsevier]

The mechanism of action of a widely used drug gemfibrozil to reduce triglycerides (TG) and apolipoprotein B (apo B) is incompletely understood. Using human hepatoblastoma (HepG2) cells, we examined the effect of gemfibrozil on apo B secretion and TG synthesis catalyzed by diacylglycerol acyltransferase (DGAT), primary processes associated with the secretion of LDL. Gemfibrozil significantly decreased apo B secretion by HepG2 cells. It decreased oleate-induced stimulation of apo B secretion, suggesting that gemfibrozil-mediated inhibition of apo B secretion may be dependent on the synthesis of TG catalyzed by DGAT. Pre-incubation of HepG2 cells with gemfibrozil (200–400 μmol/l for 48 h) significantly inhibited microsomal DGAT activity. When added directly to the DGAT assay system containing control microsomes, gemfibrozil significantly inhibited the activity of DGAT by 14–25%. Gemfibrozil (200–400 μmol/l) inhibited TG synthesis by 47–50% as measured by the incorporation of 3H-oleic acid into TG. The data indicate that gemfibrozil inhibits DGAT activity resulting in decreased synthesis of TG and its availability for apo B lipidation rendering it susceptible to intracellular apo B degradation leading to the decreased secretion. These in-vitro data suggest a novel additional mechanism by which gemfibrozil lowers plasma TG and atherogenic apo B lipoproteins in dyslipidemic patients. [Copyright &y& Elsevier]

Aqueous potassium‐ion batteries with inherent safety, high abundance, and competitive hydrated ion‐radius point to future availability in energy storage. However, the extensively studied electrodes (metal‐oxides, Prussian‐blue‐analogues, etc.) typically suffer from undesirable capacities and sluggish kinetics owing to overwhelming ion diffusion barriers. Herein, for the first time, the metal chalcogenide bismuth selenide reinforced by iodine‐doping (I‐Bi2Se3) is implemented for high‐performance aqueous potassium‐ion storage. The co‐intercalation mechanism of potassium‐ion with proton in I‐Bi2Se3 is entirely revealed by operando synchrotron X‐ray diffraction and substantial ex‐situ analysis, and the excellent interlayer diffusion kinetics in the high‐conductive host are further enhanced by iodine‐doping, as proposed by theoretic calculations. Therefore, the resulting high diffusion coefficient and low interfacial transfer resistance endow I‐Bi2Se3 with superior rate performance (109.2 mAh g−1 at 10 A g−1) and cycling stability (91% capacity retention after 1200 cycles). Employing in hybrid‐ion batteries matching zinc metal, the highest reversible aqueous potassium‐ion storage to date of 316.8 mAh g−1 is demonstrated, permitting the establishment of reliable performance pouch cells. The promising aqueous potassium intercalation chemistry built in the improved metal chalcogenide is proven to be extendable to other hybrid‐ion devices, offering novel mechanistic insights and material practices for aqueous energy storage. [ABSTRACT FROM AUTHOR]

Shadow indexes can effectively and easily detect shadows in remote sensing images. Although various shadow indexes are used, there is no consensus regarding the optimal one. The evaluation criteria used to determine the performance of shadow indexes are relatively homogeneous. A multi-criteria evaluation of widely used shadow indexes is necessary to analyse the application performance of each index in different scenarios. The eight most common shadow indexes were selected for this study. In addition to the standard visual inspection and accuracy assessment criteria, the cosine of solar incidence (cosi) was introduced to evaluate the sensitivity of the indexes to illumination intensity. Furthermore, in order to evaluate the separability of shadows and confusable objects, the interquartile range (IQR) of shadows and confusable objects was used to calculate the 1.5IQR separation ratio (1.5IQRSR). The multi-scale evaluation included mountain and urban scenarios, with the sensitivity to illumination intensity used to assess mountain scenarios and the capacity to separate confusable objects used to assess urban scenarios. The results obtained for each evaluation criterion were aggregated to form the multi-criteria evaluation score of the shadow indexes. The results show that the combinational shadow index (CSI), shadow detector index (SDI), and shadow index (SI) perform relatively well for each evaluation criterion. SI and CSI had the highest shadow detection accuracy in mountain and urban areas, respectively. The shadow enhancement index (SEI) and CSI had relatively high sensitivity to illumination intensity, especially CSI. In addition, CSI has the highest water separability but low separability for blue and dark impervious surfaces. SDI and SI have high separability for confusable objects, but they are ineffective in separating water bodies and less sensitive to illumination intensity. In summary, CSI, SDI, and SI excel in many application contexts, whereas the performances of the remaining five indexes were similar in all respects. [ABSTRACT FROM AUTHOR]

At present, as a research hotspot for time series data (TSD), the deep clustering analysis of TSD has huge research value and practical significance. However, there still exist the following three problems: (1) For deep clustering based on joint optimization, the inevitably mutual interference existing between deep feature representation learning progress and clustering progress leads to difficult model training especially in the initial stage, the possible feature space distortion, inaccurate and weak feature representation; (2) Existing deep clustering methods are difficult to intuitively define the similarity of time series and rely heavily on complex feature extraction networks and clustering algorithms. (3) Multidimensional time series have the characteristics of high dimensions, complex relationships between dimensions, and variable data forms, thus generating a huge feature space. It is difficult for existing methods to select discriminative features, resulting in generally low accuracy of methods. Accordingly, to address the above three problems, we proposed a novel general two-stage multi-dimensional spatial features based multi-view deep clustering method 1DCAE-TSSAMC (One-dimensional deep convolutional auto-encoder based two-stage stepwise amplification multi-clustering). We conducted verification and analysis based on real-world important multi-scenario, and compared with many other benchmarks ranging from the most classic approaches such as K-means and Hierarchical to the state-of-the-art approaches based on deep learning such as Deep Temporal Clustering (DTC) and Temporal Clustering Network (TCN). Experimental results show that the new method outperforms the other benchmarks, and provides more accurate, richer, and more reliable analysis results, more importantly, with significant improvement in accuracy and spatial linear separability. [ABSTRACT FROM AUTHOR]

Rocking‐chair configurations based on advanced anodes with reliable zinc‐ion storage can intrinsically avoid the deterioration of flexible zinc‐ion energy devices by corrosion, dendrites, and inadequate mechanical stability of zinc metal, yet the identification of durable anode materials is still challenging. Herein, the first reported conversion‐type Cu2‐xSe is proposed as an ultra‐stable anode for flexible rocking‐chair aqueous zinc‐ion batteries. Differing from these well‐recognized intercalation‐type copper selenide anodes, the unique Cu2‐xSe structure features a preferred thermodynamic deep transformation path, and the high‐reversible conversion reaction is fully illuminated by in situ synchrotron X‐ray diffraction and substantial ex situ characterization, demonstrating an outstanding performance combination of high capacity (150 mAh g−1 at 0.5 A g−1) and record‐high stability (91% capacity retention after 20 000 cycles at 5 A g−1 in Cu2‐xSe||ZnxMnO2 full cells). Consequently, fiber‐shaped batteries using Cu2‐xSe as the anode are successfully assembled and exhibited an ultra‐long life (89.8% capacity retention after 900 cycles) and extraordinary flexibility (98% capacity retention after 4500 cycles of bending), far exceeding those of representative flexible batteries previously reported. The findings provide novel insights into the energy storage mechanism of copper selenides and, as an elegant forerunner, offer a plausible path for the development of rocking‐chair flexible aqueous zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

SAR imagery plays a crucial role in geological and environmental monitoring, particularly in highland mountainous regions. However, inherent geometric distortions in SAR images often undermine the precision of remote sensing analyses. Accurately identifying and classifying these distortions is key to analyzing their origins and enhancing the quality and accuracy of monitoring efforts. While the layover and shadow map (LSM) approach is commonly utilized to identify distortions, it falls short in classifying subtle ones. This study introduces a novel LSM ground-range slope (LG) method, tailored for the refined identification of minor distortions to augment the LSM approach. We implemented the LG method on Sentinel-1 SAR imagery from the tri-junction area where the Xiaojiang, Pudu, and Jinsha rivers converge at the Yunnan-Sichuan border. By comparing effective monitoring-point densities, we evaluated and validated traditional methods—LSM, R-Index, and P-NG—against the LG method. The LG method demonstrates superior performance in discriminating subtle distortions within complex terrains through its secondary classification process, which allows for precise and comprehensive recognition of geometric distortions. Furthermore, our research examines the impact of varying slope parameters during the classification process on the accuracy of distortion identification. This study addresses significant gaps in recognizing geometric distortions and lays a foundation for more precise SAR imagery analysis in complex geographic settings. [ABSTRACT FROM AUTHOR]

Conversion‐type tellurium‐based cathodes have attracted great attention in aqueous zinc‐ion batteries (AZIBs) due to potentially high capacity with impressive Te4+/Te0/Te2− conversion. However, impeded by the low‐conductivity Te4+ species and unpreferred kinetics, realizing deep zinc‐tellurium redox remains a major challenge. Herein, energetic NiTe2 nanosheets are first proposed and implemented as preprepared tellurium‐based deep redox cathodes in AZIBs with accelerated electron transport and favorable kinetics. Operando synchrotron X‐ray diffraction and comprehensive ex situ characterizations demonstrate that Te4+ species from direct oxidation of NiTe2 in dilute mild‐aqueous electrolyte undergo a thermodynamic two‐step TeO2→Te→ZnTe discharge process, while the intertwined tellurium oxides and high‐conductivity nickel monomers derived in situ from NiTe2 nanosheets promote a kinetics‐preferred one‐step ZnTe→TeO2 charging conversion with significantly boosted reversibility. Therefore, a high capacity of 510 mAh g−1 at 50 mA g−1 and 93% capacity retention over 400 cycles at 2000 mA g−1 are established. Operando pH tracking and electrode‐electrolyte engineering analyses define that the mild electrolyte environment rich in moisture and electrode conductivity optimization are both critical for achieving reversible tellurium deep redox conversion. [ABSTRACT FROM AUTHOR]

Dendrite‐free Zn anode is the key to avoiding battery failure, which is largely determined by the crystal growth during the electrodeposition process. Therefore, controlling the specific crystal orientation growth of Zn is imperative for high‐performing aqueous zinc ion batteries. Herein, an electrocrystallization orientation regulation strategy is proposed to achieve near‐unity stacked Zn (002) texture growth. Featuring the zincophilic nature and high electronegative carboxylate radical, disodium maleate molecules tend to selectively adsorb on the Zn (002) crystal plane, forming a dynamic protection layer. This adsorption layer regulates Zn2+ diffusion along [100] and [101] orientations with the lowest deposition rate on the (002) plane, homogenizes Zn2+ flux, and keeps away water from Zn surface, constructing the flattened and horizontally arranged Zn deposition layer with dominantly Zn (002) texture and inhibited side‐reaction. Consequently, the Zn anode with near‐unity stacked (002) texture exhibits a 40‐fold enhancement in running lifetime beyond 3200 h and improved coulombic efficiency of 99.81% over 3000 cycles than that with bare ZnSO4 electrolyte. Even at harsh plating/stripping conditions of 30 and 30 mAh cm−2, the Zn anode still sustains state‐of‐the‐art stability over 120 h, enabling a substantial advance in the long‐term stability of the battery. [ABSTRACT FROM AUTHOR]

The Maximum Vertex Coverage problem (abbreviated as MVC) is to maximum the number of edges covered by a set of vertices of size exactly K on a graph. This problem is the dual of the vertex cover problem and has attracted a lot of interests in the literature of approximation algorithm. So far, the best approximation factor for the MVC problem is 3/4, which is obtained using an LP-rounding method. The main results of this paper are new approximation algorithms for MVC on cubic graphs and 3-bounded graphs (the vertex degrees are at most 3). The approximation factor on cubic graphs is 79/90 (≈0.878), which is tight by analyzing the existence of a feasible solution for a linear programming system. This algorithm can also be extended to 3-bounded graphs and guarantees an approximation factor of 19/24 (≈0.792). [ABSTRACT FROM AUTHOR]

Conversion‐type electrodes offer a promising multielectron transfer alternative to intercalation hosts with potentially high‐capacity release in batteries. However, the poor cycle stability severely hinders their application, especially in aqueous multivalence‐ion systems, which can fundamentally impute to anisotropic ion diffusion channel collapse in pristine crystals and irreversible bond fracture during repeated conversion. Here, an amorphous bismuth sulfide (a‐BS) formed in situ with unprecedentedly self‐controlled moderate conversion Cu2+ storage is proposed to comprehensively regulate the isotropic ion diffusion channels and highly reversible bond evolution. Operando synchrotron X‐ray diffraction and substantive verification tests reveal that the total destruction of the Bi─S bond and unsustainable deep alloying are fully restrained. The amorphous structure with robust ion diffusion channels, unique self‐controlled moderate conversion, and high electrical conductivity discharge products synergistically boosts the capacity (326.7 mAh g−1 at 1 A g−1), rate performance (194.5 mAh g−1 at 10 A g−1), and long‐lifespan stability (over 8000 cycles with a decay rate of only 0.02 ‰ per cycle). Moreover, the a‐BS Cu2+‖Zn2+ hybrid ion battery can well supply a stable energy density of 238.6 Wh kg−1 at 9760 W kg−1. The intrinsically high‐stability conversion mechanism explored on amorphous electrodes provides a new opportunity for advanced aqueous storage. [ABSTRACT FROM AUTHOR]

Background: Alternative splicing allows the pre-mRNAs of a gene to be spliced into various mRNAs, which greatly increases the diversity of proteins. High-throughput sequencing of mRNAs has revolutionized our ability for transcripts reconstruction. However, the massive size of short reads makes de novo transcripts assembly an algorithmic challenge. Results: We develop a novel radical framework, called DTA-SiST, for de novo transcriptome assembly based on suffix trees. DTA-SiST first extends contigs by reads that have the longest overlaps with the contigs' terminuses. These reads can be found in linear time of the lengths of the reads through a well-designed suffix tree structure. Then, DTA-SiST constructs splicing graphs based on contigs for each gene locus. Finally, DTA-SiST proposes two strategies to extract transcript-representing paths: a depth-first enumeration strategy and a hybrid strategy based on length and coverage. We implemented the above two strategies and compared them with the state-of-the-art de novo assemblers on both simulated and real datasets. Experimental results showed that the depth-first enumeration strategy performs always better with recall and also better with precision for smaller datasets while the hybrid strategy leads with precision for big datasets. Conclusions: DTA-SiST performs more competitive than the other compared de novo assemblers especially with precision measure, due to the read-based contig extension strategy and the elegant transcripts extraction rules. [ABSTRACT FROM AUTHOR]

Malaria transmission-blocking vaccines target mosquito-stage parasites and will support elimination programmes. Gamete vaccine Pfs230D1-EPA/Alhydrogel induced superior activity to zygote vaccine Pfs25-EPA/Alhydrogel in malaria-naive US adults. Here, we compared these vaccines in malaria-experienced Malians. We did a pilot safety study then double-blind, block-randomised, comparator-controlled main-phase trial in malaria-intense Bancoumana, Mali. 18–50-year-old healthy non-pregnant, non-breastfeeding consenting adult residents were randomly assigned (1:1:1:1) to receive four doses at months 0, 1, 4·5, and 16·5 of either 47 μg Pfs25, 40 μg Pfs230D1 or comparator (Twinrix or Menactra)—all co-administered with normal saline for blinding—or 47 μg Pfs25 plus 40 μg Pfs230D1 co-administered. We documented safety and tolerability (primary endpoint in the as-treated populations) and immunogenicity (secondary endpoint in the as-treated populations: ELISA, standard-membrane-feeding assay, and mosquito direct skin feed assay). This trial is registered at ClinicalTrials.gov , NCT02334462. Between March 19, and June 2, 2015, we screened 471 individuals. Of 225 enrolled for the pilot and main cohorts, we randomly assigned 25 participants to pilot safety cohort groups of five (20%) to receive a two-dose series of Pfs25-EPA/Alhydrogel (16 μg), Pfs230D1-EPA/Alhydrogel (15 μg) or comparator, followed by Pfs25-EPA/Alhydrogel (16 μg) plus Pfs230D1-EPA/Alhydrogel (15 μg) or comparator plus saline. For the main cohort, we enrolled 200 participants between May 11 and June 2, 2015, to receive a four-dose series of 47 μg Pfs25-EPA/Alhydrogel plus saline (n=50 [25%]; Pfs25), 40 μg Pfs230D1-EPA/Alhydrogel plus saline (n=49 [25%]; Pfs230D1), 47 μg Pfs25-EPA/Alhydrogel plus 40 μg Pfs230D1-EPA/Alhydrogel (n=50 [25%]; Pfs25 plus Pfs230D1), or comparator (Twinrix or Menactra) plus saline (n=51 [25%]). Vaccinations were well tolerated in the pilot safety and main phases. Most vaccinees became seropositive after two Pfs230D1 or three Pfs25 doses; peak titres increased with each dose thereafter (Pfs230D1 geometric mean: 77·8 [95% CI 56·9–106·3], 146·4 [108·3–198·0], and 410·2 [301·6–558·0]; Pfs25 geometric mean 177·7 [130·3–242·4] and 315·7 [209·9–474·6]). Functional activity (mean peak transmission-reducing activity) appeared for Pfs230D1 (74·5% [66·6–82·5]) and Pfs25 plus Pfs230D1 (68·6% [57·3–79·8]), after the third dose and after the fourth dose (88·9% [81·7–96·2] for Pfs230D1 and 85·0% [78·4–91·5] Pfs25 plus Pfs230D1) but not for Pfs25 (58·2% [49·1–67·3] after the third dose and 58·2% [48·5–67·9] after the fourth dose). Pfs230D1 transmission-reducing activity (73·7% [64·1–83·3]) persisted 10 weeks after the fourth dose. Transmission-reducing activity of 80% was estimated at 1659 ELISA units for Pfs25, 218 for Pfs230D1, and 223 for Pfs230D1 plus Pfs25. After 3850 direct skin feed assays, 35 participants (12 Pfs25, eight Pfs230D1, five Pfs25 plus Pfs230D1, and ten comparator) had transmitted parasites at least once. The proportion of positive assays in vaccine groups (Pfs25 33 [3%] of 982 [–0·013 to 0·014], Pfs230D1 22 [2%] of 954 [–0·005 to 0·027], and combination 11 [1%] of 940 [–0·024 to 0·002]) did not differ from that of the comparator (22 [2%] of 974), nor did Pfs230D1 and combination groups differ (–0·024 to 0·001). Pfs230D1 but not Pfs25 vaccine induces durable serum functional activity in Malian adults. Direct skin feed assays detect parasite transmission to mosquitoes but increased event rates are needed to assess vaccine effectiveness. Intramural Research Program of the National Institute of Allergy and Infectious Diseases and US National Institutes of Health. [ABSTRACT FROM AUTHOR]

The genomic scaffold filling problem has attracted a lot of attention recently. The problem is on filling an incomplete sequence (scaffold) I into I ′ , with respect to a complete reference genome G , such that the number of common/shared adjacencies between G and I ′ is maximized. The problem is NP-complete, and admits a constant-factor approximation. However, the sequence input I is not quite practical and does not fit most of the real datasets (where a scaffold is more often given as a list of contigs). In this paper, we revisit the genomic scaffold filling problem by considering this important case when a scaffold S is given, the missing genes can only be inserted in between the contigs, and the objective is to maximize the number of common adjacencies between G and the filled genome S ′ . For this problem, we present a simple NP-completeness proof, we then present a factor-2 approximation algorithm. [ABSTRACT FROM AUTHOR]

Breakpoint graph has been widely used as a key data structure in algorithm design for genome rearrangements. The problem of breakpoint graph cycle decomposition, which asks for a largest collection of edge-disjoint cycles, is crucial in computing rearrangement distances between genomes. This problem is NP-hard, and can be approximated to 1.4193 + ϵ . It is still open for deciding whether a breakpoint graph can admit a cycle decomposition with none other than 2-cycles. In this paper, we present a linear time algorithm to detect whether a breakpoint graph can be decomposed into none other than 2-cycles. [ABSTRACT FROM AUTHOR]

The further application of promising transition‐metal chalcogenides (TMCs) cathodes in dilute neutral aqueous Zn batteries (AZBs) is mainly plagued by unsatisfactory working voltages (usually <1 V vs Zn2+/Zn) and their conventional cationic redox centers reaching theoretical capacity limit. Hence, to break the confinement, a novel Zn‐Cu2‐xSe battery is developed in dilute neutral‐aqueous electrolyte by introducing a tailored charge‐carrier, which not only alters the intercalation potential of ions embedded into Cu2‐xSe (vs Zn2+/Zn, working voltage from ≈0.4 to ≈1.2 V) but also activates the anionic redox centers of Cu2‐xSe (capacity release from 143.4 to 323.2 mAh g−1 at 0.4 A g−1). In situ synchrotron X‐ray diffraction (SXRD) and substantial ex situ characterizations reveal the multi‐step phase conversion undergone by cathode and triggered additional Se‐based anionic (Sen2−/Se2−) reversible redox reaction. A multi‐electron synergistic transfer process established on the cationic‐anionic redox centers circumvents the slow relaxation of single‐ion charge compensation achieving high‐capacity and enhanced ion diffusion kinetics. As a result, an extraordinary energy density of up to 406.2 Wh kg−1 at 240 W kg−1 is implemented (calculated based on the mass of Cu2‐xSe cathode), which is ≈8.4 times higher than that of conventional Zn‐Cu2‐xSe batteries, representing an advanced development toward energetic AZBs. [ABSTRACT FROM AUTHOR]

The dehydration kinetics of graphene oxide (GO) were investigated by in-situ two-dimensional grazing incident X-ray diffraction. We found that the interlayer spacing of the GO membrane gradually decreased as the annealing temperature increased and as time elapsed. Surprisingly, we observed the formation of an intermediate “water-rich” GO layers at 25 °C with an interlayer spacing of approximately 15.2 Å, which was caused by the intercalation of two additional layers of water into the interlayers of the GO membrane. Moreover, three types of water trapped in GO were clearly distinguished upon isothermal annealing at various temperatures. Below 160 °C, the removal of “bulk water” and “confined water” resulted in a smaller interlayer spacing and the preservation of oxygen-containing functional groups. At 160 °C or higher, “bound water” was removed and oxygen-containing functional groups were lost, which contributed to the reduction of GO. The dehydration behaviour and structural evolution of GO investigated here is useful for understanding and controlling the properties of GO membranes for permeation, separation and electronic applications. [ABSTRACT FROM AUTHOR]

A clause is not-all-equal satisfied if it has at least one literal assigned with true and one literal assigned with false . Max NAE-SAT is given by a boolean variable set U and a clause set C , asks to find an assignment of U , such that the number of not-all-equal satisfied clauses in C is maximized. Max NAE-SAT turns into Max NAE- k -SAT if each clause contains exactly k literals. Local search has long been used in various SAT solvers. However, little has been done on local search to approximate Max NAE- k -SAT. Moreover, it is still open for what a quantitative bound could Max NAE- k -SAT be approximated to, at best. In this paper, we propose a local search algorithm which can approximate Max NAE- k -SAT to 2 k − 1 2 k − 1 − 1 for each fixed k ≥ 2 . Then we show that Max NAE- k -SAT cannot be approximated within 2 k − 1 2 k − 1 − 1 in polynomial time, if P ≠ NP . The algorithm for Max NAE- k -SAT can be extended to approximate Max NAE-SAT where each clause contains at least k literals to 2 k − 1 2 k − 1 − 1 . Using the algorithm for Max NAE-SAT where each clause contains at least k literals, we present a new algorithm to approximate Max-SAT where each clause contains at least k literals to 2 k 2 k − 1 . [ABSTRACT FROM AUTHOR]