Search

Liquid droplets hanging from solid surfaces are commonplace, but their physics is complex. Examples include dew or raindrops hanging onto wires or droplets accumulating onto a cover placed over warm food or windshields. In these scenarios, determining the force of detachment is crucial to rationally design technologies. Despite much research, a quantitative theoretical framework for detachment force remains elusive. In response, we interrogated the elemental droplet surface system via comprehensive laboratory and computational experiments. The results reveal that the Young Laplace equation can be utilized to accurately predict the droplet detachment force. When challenged against experiments with liquids of varying properties and droplet sizes, detaching from smooth and microtextured surfaces of wetting and non wetting chemical makeups, the predictions were in an excellent quantitative agreement. This study advances the current understanding of droplet physics and will contribute to the rational development of technologies.

International audience; In the last two decades, maintenance as an essential method to prevent machine breakdown has achieved undoubted importance in process industries and manufacturing systems. With ever increasing high-quality products demand, the number of tool change or machine maintenance become quite remarkable. Besides, industry 4.0 supports manufacturing enterprises to explore more efficient and intelligent scheduling modes. Machine periodic maintenance has a significant impact on the scheduling of many manufacturing companies, it therefore has become one of the factors they must consider. Despite this, theoretical analysis for the machine scheduling problem with periodic maintenance has not received considerable critical attention in previous studies. Motivated by scheduling practice, this work revisits a single machine scheduling problem with periodic maintenance to minimize the number of tardy jobs. First, a polynomial-time solvable case is identified. Then we propose a dynamic programming algorithm to solve the general case. At last, the non-approximability is proven.

Chaofan Xie,1,* Guanzhao Liang,2,* Yinfeng Xu,1 Erhu Lin3 1Department of Orthopaedics, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong Province, People’s Republic of China; 2Department of Emergency, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong Province, People’s Republic of China; 3Department of Spine Surgery, Shenzhen People’s Hospital, Shenzhen, Guangdong Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Erhu Lin Department of Spine SurgeryShenzhen People’s Hospital, 1017 Dongmen North Road, Luohu District, Shenzhen, Guangdong Province 518020, People’s Republic of ChinaTel +86-13760341589Email jiqbzbb@163.comBackground: Osteosarcoma (OS) is the most common primary malignancy of bone with a high incidence in children. Circular RNAs (circRNAs) play crucial roles in the carcinogenesis and chemoresistance of OS. In the current work, we focused on the function and mechanism of hsa_circ_0003496 (circ_0003496) in OS progression and chemoresistance.Materials and Methods: The expression levels of circ_0003496, miR-370 and Krüppel-like factor 12 (KLF12) mRNA were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The Cell Counting Kit-8 (CCK-8) assay was used to assess the 50% inhibitory concentration (IC50) value and cell proliferation. Cell migration, invasion and apoptosis were detected by transwell assay and flow cytometry, respectively. Western blot analysis was performed to assess the protein level. Targeted relationships among circ_0003496, miR-370 and KLF12 were validated by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays. Animal studies were carried out to observe the role of circ_0003496 in vivo.Results: Our results indicated that circ_0003496 up-regulation was associated with doxorubicin (DXR) resistance of OS. Circ_0003496 knockdown repressed DXR-resistant OS cell proliferation, migration and invasion, and enhanced apoptosis and DXR sensitivity. Circ_0003496 functioned as a sponge of miR-370, and miR-370 mediated the regulatory effect of circ_0003496 depletion on DXR-resistant OS cell progression and DXR sensitivity. KLF12 was a direct target of miR-370, and miR-370 overexpression suppressed cell progression and enhanced DXR sensitivity by KLF12. Moreover, circ_0003496 protected against KLF12 repression through sponging miR-370. Additionally, circ_0003496 knockdown hampered tumor growth and promoted DXR sensitivity in vivo.Conclusion: Our present work suggested that the knockdown of circ_0003496 suppressed OS progression and enhanced DXR sensitivity at least partially through modulating KLF12 expression via functioning as a miR-370 sponge, highlighting new opportunities for OS management.Keywords: osteosarcoma, OS, circ_0003496, miR-370, Krüppel-like factor 12, KLF12, chemoresistance

Despite the emphases on computability issues in research of algorithmic game theory, the limited computational capacity of players have received far less attention. This work examines how different levels of players' computational ability (or "rationality") impact the outcomes of sequential scheduling games. Surprisingly, our results show that a lower level of rationality of players may lead to better equilibria. More specifically, we characterize the sequential price of anarchy (SPoA) under two different models of bounded rationality, namely, players with $k$-lookahead and simple-minded players. The model in which players have $k$-lookahead interpolates between the "perfect rationality" ($k=n-1$) and "online greedy" ($k=0$). Our results show that the inefficiency of equilibria (SPoA) increases in $k$ the degree of lookahead: $\mathrm{SPoA} = O (k^2)$ for two machines and $\mathrm{SPoA} = O\left(2^k \min \{mk,n\}\right)$ for $m$ machines, where $n$ is the number of players. Moreover, when players are simple-minded, the SPoA is exactly $m$, which coincides with the performance of "online greedy"., Comment: Extended abstract to appear in WINE 2020

We study an on-line scheduling problem that is motivated by applications such as car-sharing for trips between an airport and a group of hotels. Users submit ride requests, and the scheduler aims to accept requests of maximum total profit using k servers (cars). Each ride request specifies the pick-up time, the pick-up location, and the drop-off location, where one of the two locations must be the airport. A request must be submitted a fixed amount of time before the pick-up time. The scheduler has to decide whether or not to accept a request immediately at the time when the request is submitted (booking time). In the unit travel time variant, the travel time between the airport and any hotel is a fixed value t. We give a 2-competitive algorithm for the case in which the booking interval (pick-up time minus booking time) is at least t and the number of servers is even. In the arbitrary travel time variant, the travel time between the airport and a hotel may have arbitrary length between t and L t for some L >= 1. We give an algorithm with competitive ratio O(log L) if the number of servers is at least ceil[log L]. For both variants, we prove matching lower bounds on the competitive ratio of any deterministic on-line algorithm.

We study an on-line scheduling problem that is motivated by applications such as car-sharing, in which users submit ride requests, and the scheduler aims to accept requests of maximum total profit using k servers (cars). Each ride request specifies the pick-up time and the pick-up location (among two locations, with the other location being the destination). The scheduler has to decide whether or not to accept a request immediately at the time when the request is submitted (booking time). We consider two variants of the problem with respect to constraints on the booking time: In the fixed booking time variant, a request must be submitted a fixed amount of time before the pick-up time. In the variable booking time variant, a request can be submitted at any time during a certain time interval (called the booking horizon) that precedes the pick-up time. We present lower bounds on the competitive ratio for both variants and propose a balanced greedy algorithm (BGA) that achieves the best possible competitive ratio. We prove that, for the fixed booking time variant, BGA is 1.5-competitive if k=3i ( i in N) and the fixed booking length is not less than the travel time between the two locations; for the variable booking time variant, BGA is 1.5-competitive if k=3i ( i in N) and the length of the booking horizon is less than the travel time between the two locations, and BGA is 5/3-competitive if k=5i ( i in N) and the length of the booking horizon is not less than the travel time between the two locations.

In this paper, we consider an on-line scheduling problem that is motivated by applications such as car sharing, in which users submit ride requests, and the scheduler aims to accept requests of maximum total profit using two servers (cars). Each ride request specifies the pick-up time and the pick-up location (among two locations, with the other location being the destination). The length of the time interval between the submission of a request (booking time) and the pick-up time is fixed. The scheduler has to decide whether or not to accept a request immediately at the time when the request is submitted. We present lower bounds on the competitive ratio for this problem and propose a smart greedy algorithm that achieves the best possible competitive ratio.

We consider the well-studied game-theoretic version of machine scheduling in which jobs correspond to self-interested users and machines correspond to resources. Here each user chooses a machine trying to minimize her own cost, and such selfish behavior typically results in some equilibrium which is not globally optimal: An equilibrium is an allocation where no user can reduce her own cost by moving to another machine, which in general need not minimize the makespan, i.e., the maximum load over the machines. We provide tight bounds on two well-studied notions in algorithmic game theory, namely, the price of anarchy and the strong price of anarchy on machine scheduling setting which lies in between the related and the unrelated machine case. Both notions study the social cost (makespan) of the worst equilibrium compared to the optimum, with the strong price of anarchy restricting to a stronger form of equilibria. Our results extend a prior study comparing the price of anarchy to the strong price of anarchy for two related machines (Epstein, Acta Informatica 2010), thus providing further insights on the relation between these concepts. Our exact bounds give a qualitative and quantitative comparison between the two models. The bounds also show that the setting is indeed easier than the two unrelated machines: In the latter, the strong price of anarchy is $2$, while in ours it is strictly smaller., Extended abstract to appear in COCOA'17

The mutations of BRCA1 and p53 genes have been simultaneously characterized in many tumors. However, their coexpression and associations have not been investigated quantitatively in prostate cancer. In the present study, the expressions of the mutated BRCA1 mRNA and p53 mRNA were examined in 48 Chinese prostate cancer cases and 10 corresponding adjacent benign tissues with in situ hybridization. The 5-year survival rates of the corresponding patients after operation were investigated. The results showed that the positive expressions of the mutated BCRA1 mRNA and p53 mRNA are involved in prostate cancer (P < 0.05). Moreover, there is a closed negative association between the expressions of the mutated BRCA1 gene and p53 gene in the mRNA level with the progression, angiogenesis, metastasis, and survival rate of prostate cancer. Their coexpression and negative association suggest that the two altered tumor suppressor genes might interact functionally in prostate cancer to provide a potential signal determining a prognosis of the tumor metastasis and survival rate. Further work will be done to elucidate the interaction mechanisms in prostate cancer.

In the problem of online time series search introduced by El-Yaniv et al. (2001) [1], a player observes prices one by one over time and shall select exactly one of the prices on its arrival without the knowledge of future prices, aiming to maximize the selected price. In this paper, we extend the problem by introducing profit function. Considering two cases where the search duration is either known or unknown beforehand, we propose two optimal deterministic algorithms respectively. The models and results in this paper generalize those of El-Yaniv et al. (2001) [1].

Taking into account the uncertain delay of work on the critical path, the online strategy and competitive analysis are introduced into time-cost optimizing in project management. The competitive ratio of the strategy is given, and the prerushing strategy is proved to be the best determinate one. The relationship between the general strategy and the optimal offline strategy is analyzed, and three properties are discovered. On this basis, this article designs the risk-tolerance strategy and proves its competitive ratio to help the project manager in choosing the optimal strategy according to his own risk tolerance and forecast.

The weighted arithmetical mean complex judgement matrix (WAMCJM) is the most common method for aggregating group opinions, but it has a shortcoming, namely the WAMCJM of the perfectly consistent judgement matrices given by experts canot guarantee its perfect consistency. An upper bound of the WAMCJM's consistency is presented. Simultaneously, a compatibility index of judging the aggregating extent of group opinions is also introduced. The WAMCJM is of acceptable consistency and is proved provided the compatibilities of all judgement matrices given by experts are smaller than the threshold value of acceptable consistency. These conclusions are important to group decision making.

Let F be a set of n (n being an even number) fixed points and let M be a set of n / 2 -1 moving points, whose locations are to be determined, in the plane. A topology is a set of edges connecting these points in the set V=F\cup M . Let E be a full 4-degree Steiner topology; i.e., the topology forms a tree which contains fixed points of degree 1 and moving points of degree 4, and let H(E) be a set of topologies which include E and its degeneracies. We define a canonical tree over V as one whose topology belongs to H(E) and in which the sum of two adjacent angles around any node is not less than π . In this paper we prove that if a canonical tree exists, then it is the shortest (degree-4) network under a given topology E . We present an O(n2) time algorithm for finding a degree-4 shortest network whose topology belongs to H(E) .

The general Bandpass-$B$ problem is NP-hard and can be approximated by a reduction into the weighted $B$-set packing problem, with a worst case performance ratio of $O(B^2)$. When $B = 2$, a maximum weight matching gives a 2-approximation to the problem. In this paper, we call the Bandpass-2 problem simply the Bandpass problem. The Bandpass problem can be viewed as a variation of the maximum traveling salesman problem, in which the edge weights are dynamic rather than given at the front. We present a ${426}{227}$-approximation algorithm for the problem. Such an improved approximation is built on an intrinsic structural property proven for the optimal solution and several novel schemes to partition a $b$-matching into desired matchings.

LetT denote a finite set of points in a unit isoscele right triangle (i.e., the right sides are both one),f(T) the minimum distance between pairs of points ofT, and $$f\vartriangle (n) = \mathop {\max }\limits_{||T|| = n} f(T).$$ In this paper, the exact values off Δ (n) for 2≤n≤7 and the corresponding configurations are given.

Protein derived from blue mussel (Mytilus edulis) was hydrolysed using four kinds of proteases (pepsin, papain, neutrase and alcalase), and the neutrase hydrolysate (BNH) obtained by 3-h hydrolysis exhibited the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity compared to other hydrolysates. By using ultrafiltration, gel filtration chromatography and reversed phase high performance liquid chromatography (RP-HPLC), a novel antioxidant peptide (BNH-P7) was isolated from BNH, and its amino acid sequence was identified as YPPAK (Tyr-Pro-Pro-Ala-Lys) with molecular weight of 574 Da. BNH-P7 exhibited good scavenging activity on DPPH radical, hydroxyl radical, and superoxide anion radical with EC(50) of 2.62, 0.228, and 0.072 mg/ml, respectively. BNH-P7 was also effectively against lipid peroxidation in a linoleic acid model system. The high activity of BNH-P7 was due to the small size and the presence of antioxidant and hydrophobic amino acid residues (Tyr and Pro) within its sequence.

In the present study, the preparation process of the antioxidant hydrolysate and fractions from Mytilus edulis by papain were studied. The optimal conditions of papain hydrolysis was obtained by single-factor experiments and orthogonal test with the DPPH· scavenging ratio as index. Under the optimal hydrolysis conditions of the temperature 65 °C, pH 7.0, enzymatic hydrolysis time 3 h and amount of enzyme 1.0 %, the high DPPH radical scavenging activity (28.74) of the total hydrolysate was obtained. The fraction F2 with the highest antioxidant activity was collected using Sephadex G-25 column from the total hydrolysate, with the reducing power, ·OH and DPPH· scavenging ratio being 0.807, 10.44 % and 31.4 % at the concentration of 5 mg/ml. The results revealed that the enzymatic hydrolysis method was appropriate for obtaining the product with the high antioxidant activity from the mussel protein and the F2 mainly contributed to the antioxidant activities of the total hydrolysate.

In this article we propose, for any ε > 0, a 2(1 + ε)-approximation algorithm for a facility location problem with stochastic demands. At open facilities, inventory is kept such that arriving requests find a zero inventory with (at most) some pre-specified probability. The incurred costs are the expected transportation costs from the demand points to the facilities, the operating costs of the facilities and the investment in inventory. AMS Classification: 68W25, 90B06, 60K30.

In this paper, we study the performance of Saitou and Nei's neighbor-joining method for phylogenetic reconstruction. We show that the edge l∞ radius of the method is 14. This improves an result by Atteson [The performance of neighbor-joining methods of phylogenetic reconstruction, Algorithmica 25 (1999) 251–278] and Xu et al. [A lower bound on the edge l∞ radius of Saitou and Nei's method for phylogenetic reconstruction, Inform. Process. Lett. 94(5) (2005) 225–230]. Previously, only an upper bound 14 and a lower bound 16 were known.

Bin covering is a dual version of classic bin packing. As usual, bins have size one and items with sizes between zero and one must be packed. However, in bin covering, the objective is to cover as many bins as possible, where a bin is covered if the sizes of items placed in the bin sum up to at least one. We are considering the online version of bin covering. Two classic algorithms for online bin packing that have natural dual versions are Harmonic k and Next-Fit. Though these two algorithms are quite different in nature, competitive analysis does not distinguish these bin covering algorithms.In order to understand the combinatorial structure of the algorithms better, we turn to other performance measures, namely relative worst order, random order, and max/max analysis, as well as analyses under restricted input assumptions or uniformly distributed input. In this way, our study also supplements the ongoing systematic studies of the relative strengths of various performance measures.We make the case that when guarantees are needed, even under restricted input sequences, the dual Harmonic k algorithm is preferable. In addition, we establish quite robust theoretical results showing that if items come from a uniform distribution or even if just the ordering of items is uniformly random, then dual Next-Fit is the right choice.