171 research outputs found
A Maximum Resonant Set of Polyomino Graphs
A polyomino graph is a connected finite subgraph of the infinite plane
grid such that each finite face is surrounded by a regular square of side
length one and each edge belongs to at least one square. In this paper, we show
that if is a maximum resonant set of , then has a unique perfect
matching. We further prove that the maximum forcing number of a polyomino graph
is equal to its Clar number. Based on this result, we have that the maximum
forcing number of a polyomino graph can be computed in polynomial time. We also
show that if is a maximal alternating set of , then has a unique
perfect matching.Comment: 13 pages, 6 figure
Tars: Timeliness-aware Adaptive Replica Selection for Key-Value Stores
In current large-scale distributed key-value stores, a single end-user
request may lead to key-value access across tens or hundreds of servers. The
tail latency of these key-value accesses is crucial to the user experience and
greatly impacts the revenue. To cut the tail latency, it is crucial for clients
to choose the fastest replica server as much as possible for the service of
each key-value access. Aware of the challenges on the time varying performance
across servers and the herd behaviors, an adaptive replica selection scheme C3
is proposed recently. In C3, feedback from individual servers is brought into
replica ranking to reflect the time-varying performance of servers, and the
distributed rate control and backpressure mechanism is invented. Despite of
C3's good performance, we reveal the timeliness issue of C3, which has large
impacts on both the replica ranking and the rate control, and propose the Tars
(timeliness-aware adaptive replica selection) scheme. Following the same
framework as C3, Tars improves the replica ranking by taking the timeliness of
the feedback information into consideration, as well as revises the rate
control of C3. Simulation results confirm that Tars outperforms C3.Comment: 10pages,submitted to ICDCS 201
Unavoidable Minors of Large 4-Connected Bicircular Matroids
It is known that any 3-connected matroid that is large enough is certain to contain a minor of a given size belonging to one of a few special classes of matroids. This paper proves a similar unavoidable minor result for large 4-connected bicircular matroids. The main result follows from establishing the list of unavoidable minors of large 4-biconnected graphs, which are the graphs representing the 4-connected bicircular matroids. This paper also gives similar results for internally 4-connected and vertically 4-connected bicircular matroids
DP-4-colorability of two classes of planar graphs
DP-coloring (also known as correspondence coloring) is a generalization of
list coloring introduced recently by Dvo\v{r}\'ak and Postle (2017). In this
paper, we prove that every planar graph without -cycles adjacent to
-cycles is DP--colorable for and . As a consequence, we obtain
two new classes of -choosable planar graphs. We use identification of
verticec in the proof, and actually prove stronger statements that every
pre-coloring of some short cycles can be extended to the whole graph.Comment: 12 page
High-mobility-group box protein 1 A box reduces development of sodium laurate-induced thromboangiitis obliterans in rats
ObjectiveHigh-mobility-group box protein 1 (HMGB1), as a late mediator of inflammation, plays a key role in inflammatory responses by inducing and extending the production of proinflammatory cytokines. The effect of HGMB1 in the inflammatory disease thromboangiitis obliterans (TAO) is unknown. We aimed to investigate the role of HMGB1 in sodium laurate-induced TAO in rats.MethodsMale Wistar rats were randomly divided into five groups (n = 8 each) for treatment: normal, sham-operated, TAO model, and low-dose (15 mg/kg) or high-dose (30 mg/kg) recombinant A box (rA box) infection (administered intraperitoneally once daily for 15 days). The TAO model was induced by sodium laurate and graded by gross appearance on day 15 after femoral artery injection. Histologic changes were measured by histopathology in rat femoral arteries. Plasma levels of HMGB1, thromboxane B2, 6-keto-prostaglandin F1-α, and blood cell counts and blood coagulation levels were measured. Expression of HMGB1, receptor for advanced glycation end-products (RAGE), interleukin-6, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 was assessed by immunohistochemistry and immunofluorescence, Western blot analysis, and quantitative reverse-transcription polymerase chain reaction.ResultsThe typical signs and symptoms of TAO were observed on day 15 after sodium laurate injection. The expression of HMGB1, RAGE, interleukin-6, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 was markedly increased in rat femoral arteries. Plasma levels of HMGB1 and thromboxane B2 were elevated, but the level of 6-keto-prostaglandin F1-α was decreased. Blood was in a hypercoagulable state, and prothrombin, thrombin, and activated partial thromboplastin times were all significantly shortened, whereas fibrinogen level was increased in TAO rats compared with sham-operated rats. These effects were terminated by the HMGB1 antagonist rA box.ConclusionsHMGB1 is involved in the inflammatory state in a model of TAO induced by sodium laurate in rats, probably via its receptor RAGE. As the antagonist of HMGB1, rA box can attenuate the development of TAO, which may be a potential therapeutic target for the treatment of TAO.Clinical RelevanceThromboangiitis obliterans (TAO), or Buerger disease, is a segmental nonatherosclerotic inflammatory disorder. Patients with Buerger disease have a lower quality of life because of intermittent claudication, rest pain, ulcers, and superficial thrombophlebitis. The specific etiology and pathologic mechanisms remain not elucidated. High-mobility-group box protein 1, as a late mediator of inflammation, plays a key role in inflammatory responses to tissue injury and infection by inducing and extending the production of proinflammatory cytokines. Here, we explored the role of high-mobility-group box protein 1 in rat model of TAO, discovering a new damage marker in TAO. We also investigated the unique role of recombinant A box in the prevention and treatment of TAO
PlantQTL-GE: a database system for identifying candidate genes in rice and Arabidopsis by gene expression and QTL information
We have designed and implemented a web-based database system, called PlantQTL-GE, to facilitate quantitatine traits locus (QTL) based candidate gene identification and gene function analysis. We collected a large number of genes, gene expression information in microarray data and expressed sequence tags (ESTs) and genetic markers from multiple sources of Oryza sativa and Arabidopsis thaliana. The system integrates these diverse data sources and has a uniform web interface for easy access. It supports QTL queries specifying QTL marker intervals or genomic loci, and displays, on rice or Arabidopsis genome, known genes, microarray data, ESTs and candidate genes and similar putative genes in the other plant. Candidate genes in QTL intervals are further annotated based on matching ESTs, microarray gene expression data and cis-elements in regulatory sequences. The system is freely available at
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