SFA: Stateful Forwarding Abstraction in SDN Data Plane

Abstract Software Defined Networking (SDN) is a new network architecture where network control is decoupled from forwarding and is directly programmable. However, existing techniques provide limited support for stateful forwarding in SDN data plane. Relying on the controller for all state maintaining gives rise to scalability and performance issues. In this paper, we present Stateful Forwarding Abstraction (SFA) in SDN data plane. And we design a co-processing unit in SDN switches named Forwarding Processor (FP). It can deal with state information in data plane and its instructions can be flexibly extended to meet application requirements. Through SFA, we implement stateful network processing on the datapath which covers a full range of Layer 4 to Layer 7 services. We validate its performance based on IPsec. The experiment result proves that the forwarding efficiency is greatly improved

Association study between C10orf90 gene polymorphisms and colorectal cancer

BackgroundColorectal cancer (CRC) is the third most common malignant tumor in the world. The morbidity and mortality rates in Western countries have decreased, but they are still on the rise in China. C10orf90 is associated with a variety of cancers, but the correlation between C10orf90 and CRC is not yet known.MethodsA total of 1,339 subjects were randomly enrolled in our study. After extracting their DNA, three single-nucleotide polymorphisms (SNPs) of C10orf90 were genotyped to analyze the potential relationship between these variants and CRC risk. PLINK software packages (version 1.07) were used to evaluate multiple genetic models by calculating the odds ratio (OR) and 95% confidence interval (95% CI). The best SNP–SNP interaction model was defined by the multifactor dimensionality reduction (MDR) analysis.ResultsC10orf90 rs12412320 was significantly associated with CRC risk (p = 0.006) and might be associated with the lower CRC risk (OR: 0.78; 95% CI: 0.65–0.93). The relationship of rs12412320 with lower CRC risk was found in people aged >60 years and ≤60 years, women, non-smokers, or non-drinkers. Rs11245008 in people aged ≤60 years and rs11245007 among men had a higher CRC susceptibility. Rs12412320 was related to the lower risk of advanced stages (III/IV stage), while rs11245007 might be associated with the higher risk of advanced stages (III/IV stage). Moreover, rs12412320 had the most significant relationship with the susceptibility to rectal cancer.ConclusionThis study is the first to report between C10orf90 gene polymorphisms and CRC risk in Chinese people, which suggests that C10orf90 rs12412320 might play a crucial role in preventing CRC occurrence

Genetics of Resistance to Common Root Rot (Spot Blotch), Fusarium Crown Rot, and Sharp Eyespot in Wheat

Due to soil changes, high density planting, and the use of straw-returning methods, wheat common root rot (spot blotch), Fusarium crown rot (FCR), and sharp eyespot (sheath blight) have become severe threats to global wheat production. Only a few wheat genotypes show moderate resistance to these root and crown rot fungal diseases, and the genetic determinants of wheat resistance to these devastating diseases are poorly understood. This review summarizes recent results of genetic studies of wheat resistance to common root rot, Fusarium crown rot, and sharp eyespot. Wheat germplasm with relatively higher resistance are highlighted and genetic loci controlling the resistance to each disease are summarized

Identification of Novel SNPs by Next-Generation Sequencing of the Genomic Region Containing the APC Gene in Colorectal Cancer Patients in China

We described an approach of identifying single nucleotide polymorphisms (SNPs) in complete genomic regions of key genes including promoters, exons, introns, and downstream sequences by combining long-range polymerase chain reaction (PCR) or NimbleGen sequence capture with next-generation sequencing. Using the adenomatous polyposis coli (APC) gene as an example, we identified 210 highly reliable SNPs by next-generation sequencing analysis program MAQ and Samtools, of which 69 were novel ones, in the 123-kb APC genomic region in 27 pair of colorectal cancers and normal adjacent tissues. We confirmed all of the eight randomly selected high-quality SNPs by allele-specific PCR, suggesting that our false discovery rate is negligible. We identified 11 SNPs in the exonic region, including one novel SNP that was not previously reported. Although 10 of them are synonymous, they were predicted to affect splicing by creating or removing exonic splicing enhancers or exonic splicing silencers. We also identified seven SNPs in the upstream region of the APC gene, three of which were only identified in the cancer tissues. Six of these upstream SNPs were predicted to affect transcription factor binding. We also observed that long-range PCR was better in capturing GC-rich regions than the NimbleGen sequence capture technique.MOST, Chin

Total syntheses of (+)-acutiphycin and (+)-trans-20,21-didehydroacutiphycin

Chapter 1 describes an asymmetric synthesis of a C(1)-C(11) fragment of (+)-acutiphycin (1). Starting from (S)-malic acid (8), alcohol (+)-7$\alpha$ was assembled in seven steps. A five step sequence involving oxidation, addition of propynyl lithium to the resultant aldehyde, oxidation of the derived alcohol, chelation controlled introduction of the methyl unit, and semi-reduction of the acetylene provided the tertiary allylic alcohol (+)-14. The highlight of the synthesis involved a stereocontrolled (2,3) -sigmatropic rearrangement to furnish alcohol (+)-15a with diastereoselective introduction of the remote methyl group at C(10). Aldehyde (+)-25 was then obtained in good yield via standard transformations. Chapter 2 describes the first total synthesis of (+)-acutiphycin (1). Advanced aldehyde (+)-32 was prepared from (+)-25 in four steps involving a chemoselective reduction of a thioester. The acutiphycin southern hemisphere (e.g. vinyl bromide (+)-33) was synthesized from 1-heptene (34) in 8 steps employing Sharpless asymmetric dihydroxylation methodology. With both aldehyde 32 and vinyl bromide 33 in hand, union of the two fragments was achieved via coupling of the vinyl Grignard reagent derived from 33 with aldehyde 32. After significant investigation, seco acid (+)-31 was identified as the suitable precursor for the crucial Yamaguchi macrolactonization reaction to construct the highly congested 16-membered macrolactone (+)-58. Selective silylation, Dess-Martin oxidation and removal of all protecting groups afforded (+)-acutiphycin (1). Chapter 3 describes the first total synthesis of (+)-trans-20,21-didehydroacutiphycin (2). The requisite vinyl bromide 64 was constructed from aldehyde (+)-10 by two different routes. With both coupling partners available, (+)-trans-20,21-didehydroacutiphycin (2) was synthesized by the same strategy used in the preparation of acutiphycin. A comparison of the NMR spectra of natural and synthetic (+)-trans-20,21-didehydroacutiphycin is also included.\sp* ftn\sp*Please refer to the dissertation for diagrams

Total syntheses of (+)-acutiphycin and (+)-trans-20,21-didehydroacutiphycin

Chapter 1 describes an asymmetric synthesis of a C(1)-C(11) fragment of (+)-acutiphycin (1). Starting from (S)-malic acid (8), alcohol (+)-7$\alpha$ was assembled in seven steps. A five step sequence involving oxidation, addition of propynyl lithium to the resultant aldehyde, oxidation of the derived alcohol, chelation controlled introduction of the methyl unit, and semi-reduction of the acetylene provided the tertiary allylic alcohol (+)-14. The highlight of the synthesis involved a stereocontrolled (2,3) -sigmatropic rearrangement to furnish alcohol (+)-15a with diastereoselective introduction of the remote methyl group at C(10). Aldehyde (+)-25 was then obtained in good yield via standard transformations. Chapter 2 describes the first total synthesis of (+)-acutiphycin (1). Advanced aldehyde (+)-32 was prepared from (+)-25 in four steps involving a chemoselective reduction of a thioester. The acutiphycin southern hemisphere (e.g. vinyl bromide (+)-33) was synthesized from 1-heptene (34) in 8 steps employing Sharpless asymmetric dihydroxylation methodology. With both aldehyde 32 and vinyl bromide 33 in hand, union of the two fragments was achieved via coupling of the vinyl Grignard reagent derived from 33 with aldehyde 32. After significant investigation, seco acid (+)-31 was identified as the suitable precursor for the crucial Yamaguchi macrolactonization reaction to construct the highly congested 16-membered macrolactone (+)-58. Selective silylation, Dess-Martin oxidation and removal of all protecting groups afforded (+)-acutiphycin (1). Chapter 3 describes the first total synthesis of (+)-trans-20,21-didehydroacutiphycin (2). The requisite vinyl bromide 64 was constructed from aldehyde (+)-10 by two different routes. With both coupling partners available, (+)-trans-20,21-didehydroacutiphycin (2) was synthesized by the same strategy used in the preparation of acutiphycin. A comparison of the NMR spectra of natural and synthetic (+)-trans-20,21-didehydroacutiphycin is also included.\sp* ftn\sp*Please refer to the dissertation for diagrams

A Coupled Finite Element and Crystal Plasticity Study of Friction Effect on Texture Evolution in Uniaxial Compression of NiTi Shape Memory Alloy

A coupled macro-meso-scale numerical simulation is applied to investigate the friction effect on texture evolution during uniaxial compression of NiTi shape memory alloy at 400 °C. In this approach, macroscale finite element simulations in consideration of various friction coefficient are conducted and then the corresponding velocity gradients in various regions are extracted mainly based on the delivery deformation gradient in the user-defined material subroutine (UMAT) in ABAQUS code. These velocity gradients are regarded as the deformation conditions applied in the mesoscale VPSC model. Simulation results in terms of macroscale finite element modeling demonstrate that only within the region of minimum deformation zone which is close to the die, friction effect has a nonnegligible influence on the velocity gradient. Simulation results with respect to the mesoscale VPSC modeling show that the affine and Neff = 10 linearization schemes provide the best predictions for NiTi shape memory alloy with cubic structure. Furthermore, the friction effect does have an influence on the evolution of slip mode activities in various deformation zones and therefore results in the inhomogeneous texture evolution within the deformed sample during uniaxial compression