• Title/Summary/Keyword: RPL

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A Measurement Study of TCP over RPL in Low-power and Lossy Networks

  • Kim, Hyung-Sin;Im, Heesu;Lee, Myung-Sup;Paek, Jeongyeup;Bahk, Saewoong
    • Journal of Communications and Networks
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    • v.17 no.6
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    • pp.647-655
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    • 2015
  • Low-power and lossy networks (LLNs) comprised of thousands of embedded networking devices can be used in a variety of applications, such as smart grid automated metering infrastructures (AMIs) and wireless sensor networks. Connecting these LLNs to the Internet has even greater potential, leading to the emerging concept of the Internet of Things (IoT). With the goal of integrating LLNs into IoT, the IETF has recently standardized RPL and 6LoWPAN to allow the use of IPv6 on LLNs. Although there already exist several studies on the the performance of RPL and embedded IPv6 stack in LLN, performance measurement and characterization of TCP over RPL in multihop LLNs is yet to be studied. In this article, we present a comprehensive experimental study on the performance of TCP over RPL in an embedded IPv6-based LLN running over a 30-node multihop IEEE 802.15.4 testbed network. Our results and findings are aimed at investigating how embedded TCP interoperates with common Linux TCP and underlying RPL (and vice versa), which furthers our understanding of the performance trade-offs when choosing TCP over RPL in IPv6-based LLNs.

On the Need for Efficient Load Balancing in Large-scale RPL Networks with Multi-Sink Topologies

  • Abdullah, Maram;Alsukayti, Ibrahim;Alreshoodi, Mohammed
    • International Journal of Computer Science & Network Security
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    • v.21 no.3
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    • pp.212-218
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    • 2021
  • Low-power and Lossy Networks (LLNs) have become the common network infrastructure for a wide scope of Internet of Things (IoT) applications. For efficient routing in LLNs, IETF provides a standard solution, namely the IPv6 Routing Protocol for LLNs (RPL). It enables effective interconnectivity with IP networks and flexibly can meet the different application requirements of IoT deployments. However, it still suffers from different open issues, particularly in large-scale setups. These include the node unreachability problem which leads to increasing routing losses at RPL sink nodes. It is a result of the event of memory overflow at LLNs devices due to their limited hardware capabilities. Although this can be alleviated by the establishment of multi-sink topologies, RPL still lacks the support for effective load balancing among multiple sinks. In this paper, we address the need for an efficient multi-sink load balancing solution to enhance the performance of PRL in large-scale scenarios and alleviate the node unreachability problem. We propose a new RPL objective function, Multi-Sink Load Balancing Objective Function (MSLBOF), and introduce the Memory Utilization metrics. MSLBOF enables each RPL node to perform optimal sink selection in a way that insure better memory utilization and effective load balancing. Evaluation results demonstrate the efficiency of MSLBOF in decreasing packet loss and enhancing network stability, compared to MRHOF in standard RPL.

Maternal killer-cell immunoglobulin-like receptors and paternal human leukocyte antigen ligands in recurrent pregnancy loss cases in Turkey

  • Elbasi, Mehmet Onur;Tulunay, Aysin;Karagozoglu, Hale;Kahraman, Semra;Eksioglu-Demiralp, Emel
    • Clinical and Experimental Reproductive Medicine
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    • v.47 no.2
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    • pp.122-129
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    • 2020
  • Objective: The survival of a semi-allogeneic fetus depends on several immunological mechanisms, and it has been suggested that recurrent pregnancy loss (RPL) could develop as a result of one or more immunological abnormalities. Methods: Compatibility between partners for human leukocyte antigen (HLA) genotypes and the relationships between maternal killer-cell immunoglobulin-like receptor (KIR) and paternal HLA-Bw4/Bw6 and HLA-C1/C2 supra-groups were investigated in 25 couples with RPL in comparison to healthy couples with children. HLA and KIR genotyping was performed using polymerase chain reaction with sequence-specific primers and/or sequence-specific oligonucleotides. Results: HLA class I incompatibility between partners, especially in HLA-B alleles, was more common in the RPL group (p= 0.01). HLA-C2 homozygosity was more frequent in the male partners of RPL couples than in other groups (p= 0.03). The KIR2DL5 gene frequency was significantly higher in both the female and male partners of RPL couples, whereas the KIR2DS3 gene frequency in male partners of RPL couples was significantly reduced (p= 0.03). The presence of KIR2DL3 in women with RPL was correlated with the presence of HLA-C2 alleles in their spouses (p= 0.03). Conclusion: Our data from a Turkish population suggest that male HLA-C2 homozygosity may play an important role in RPL. Additionally, an incidental match between male HLA-C2 and female HLA-C1 ligand KIR receptors might perturb the balance between activatory and inhibitory KIR-ligand interactions during pregnancy in couples affected by RPL. The roles of orphan KIR2DL5 and orphan KIR2DS3 in RPL remain obscure.

Relationships between dietary rumen-protected lysine and methionine with the lactational performance of dairy cows - A meta-analysis

  • Agung Irawan;Ahmad Sofyan;Teguh Wahyono;Muhammad Ainsyar Harahap;Andi Febrisiantosa;Awistaros Angger Sakti;Hendra Herdian;Anuraga Jayanegara
    • Animal Bioscience
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    • v.36 no.11
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    • pp.1666-1684
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    • 2023
  • Objective: Our objective was to examine the relationships of supplemental rumen-protected lysine (RPL) or lysine + methionine (RPLM) on lactational performance, plasma amino acids (AA) concentration, and nitrogen use efficiency of lactating dairy cows by using a meta-analysis approach. Methods: A total of 56 articles comprising 77 experiments with either RPL or RPLM supplementation were selected and analyzed using a mixed model methodology by considering the treatments and other potential covariates as fixed effects and different experiments as random effects. Results: In early lactating cows, milk yield was linearly increased by RPL (β1 = 0.013; p<0.001) and RPLM (β1 = 0.014; p<0.028) but 3.5% fat-corrected milk (FCM) and energy-corrected milk (ECM) (kg/d) was increased by only RPL. RPL and RPLM did not affect dry matter intake (DMI) but positively increased (p<0.05) dairy efficiency (Milk yield/DMI and ECM/DMI). As a percentage, milk fat, protein, and lactose were unchanged by RPL or RPLM but the yield of all components was increased (p<0.05) by feeding RPL while only milk protein was increased by feeding RPLM. Plasma Lys concentration was linearly increased (p<0.05) with increasing supplemental RPL while plasma Met increased (p<0.05) by RPLM supplementation. The increase in plasma Lys had a strong linear relationship (R2 = 0.693 in the RPL dataset and R2 = 0.769 in the RPLM dataset) on milk protein synthesis (g/d) during early lactation. Nitrogen metabolism parameters were not affected by feeding RPL or RPLM, either top-dress or when supplemented to deficient diets. Lactation performance did not differ between AA-deficient or AA-adequate diets in response to RPL or RPLM supplementation. Conclusion: RPL or RPLM showed a positive linear relationship on the lactational performance of dairy cows whereas greater improvement effects were observed during early lactation. Supplementing RPL or RPLM is recommended on deficient-AA diet but not on adequate-AA diet.

The Mutation that Makes Escherichia coli Resistant to λ P Gene-mediated Host Lethality Is Located within the DNA Initiator Gene dnaA of the Bacterium

  • Datta, Indrani;Banik-Maiti, Sarbani;Adhikari, Lopa;Sau, Subrata;Das, Niranjan;Mandal, Nitai Chandra
    • BMB Reports
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    • v.38 no.1
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    • pp.89-96
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    • 2005
  • Earlier, we reported that the bacteriophage $\lambda$ P gene product is lethal to Escherichia coli, and the E. coli rpl mutants are resistant to this $\lambda$ P gene-mediated lethality. In this paper, we show that under the $\lambda$ P gene-mediated lethal condition, the host DNA synthesis is inhibited at the initiation step. The rpl8 mutation maps around the 83 min position in the E. coli chromosome and is 94% linked with the dnaA gene. The rpl8 mutant gene has been cloned in a plasmid. This plasmid clone can protect the wild-type E. coli from $\lambda$ P gene-mediated killing and complements E. coli dnaAts46 at $42^{\circ}C$. Also, starting with the wild-type dnaA gene in a plasmid, the rpl-like mutations have been isolated by in vitro mutagenesis. DNA sequencing data show that each of the rpl8, rpl12 and rpl14 mutations has changed a single base in the dnaA gene, which translates into the amino acid changes N313T, Y200N, and S246T respectively within the DnaA protein. These results have led us to conclude that the rpl mutations, which make E. coli resistant to $\lambda$ P gene-mediated host lethality, are located within the DNA initiator gene dnaA of the host.

Transcriptional Features of the Chromosomal Region Located between the sigH and rplA Genes of Bacillus subtilis

  • Jeong, Sang-Min
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.2
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    • pp.168-172
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    • 2006
  • In this study. the transcriptional features of a 2.8 kb region spanning the sigH and rplA genes of Bacillus subtilis were clarified using synthetic oligonucleotides complementary to the transcripts of the rpmG, secE, nusG, and rplK genes. The 5' ends of three transcripts corresponding to this region were located and mapped on the chromosome via primer extension analysis. Three regions, designated Prg, Pn, and Prk, which partially share the consensus sequence recognized by ${\sigma}^A$ RNA polymerase, were theorized to function as promoter elements. The rpmG and secE genes of B. subtilis were cotranscribed from the designated prg promoter, whereas the nusG and rplK genes were transcribed separately from the Pn and Prk promoters, respectively. Accordingly, the transcriptional features, as well as the gene organization, of the region encompassing the sigH and rplA genes of B. subtilis, including the rpmG-secE-nusG-rplK genes, were determined to be distinct from those of Escherichia coli. Divergences in terms of gene organization and transcriptional features within the relevant region would serve as excellent criteria for the delineation of phylogenetic relationships among bacteria.

Evaluation of Candidate Housekeeping Genes for the Normalization of RT-qPCR Analysis using Developing Embryos and Prolarvae in Russian Sturgeon Acipenser gueldenstaedtii (러시아 철갑상어(Acipenser gueldenstaedtii) 발생 시료의 RT-qPCR 분석을 위한 내재 대조군 유전자의 선정)

  • Nam, Yoon Kwon;Lee, Sang Yoon;Kim, Eun Jeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.1
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    • pp.95-106
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    • 2018
  • To evaluate appropriate reference genes for the normalization of quantitative reverse transcription PCR (RT-qPCR) data with embryonic and larval samples from Russian sturgeon Acipenser gueldenstaedtii, the expression stability of eight candidate housekeeping genes, including beta-actin (ACTB), elongation factor-1A (EF1A), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone 2A (H2A), ribosomal protein L5 (RPL5), ribosomal protein L7 (RPL7), succinate dehydrogenase (SDHA), and ubiquitin-conjugating enzyme E2 (UBE2A), were tested using embryonic samples from 12 developmental stages and larval samples from 11 ontogenic stages. Based on the stability rankings from three statistic software packages, geNorm, NormFinder, and BestKeeper, the expression stability of the embryonic subset was ranked as UBE2A>H2A>SDHA>GAPDH>RPL5>EF1A>ACTB>RPL7. On the other hand, the ranking in the larval subset was determined as UBE2A>GAPDH>SDHA>RPL5>RPL7>H2A>EF1A>AC TB. When the two subsets were combined, the overall ranking was UBE2A>SDHA>H2A>RPL5>GAPDH>EF1A>ACTB>RPL7. Taken together, our data suggest that UBE2A and SDHA are recommended as suitable references for developmental and ontogenic samples of this sturgeon species, whereas traditional housekeepers such as ACTB and GAPDH may not be suitable candidates.

Zone based Ad Hoc Network Construction Scheme for Local IoT Networks

  • Youn, Joosang
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.12
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    • pp.95-100
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    • 2017
  • In this paper, we propose a zone based ad hoc network construction scheme which support ad hoc path between nodes in local IoT networks consisting of IoT devices with the constrained feature, such as low power, the limited transmission rate and low computing capacity. Recently, the various routing protocols have been studied to support ad hoc networking of local IoT environments. This is, because basis RPL protocol is deigned to be used for the connecting service with Internet through gateway, ad hoc path between nodes in local IoT networks is not supported in basis RPL protocol. Thus, in this paper, the proposed routing scheme provides both ad hoc path and Infra path through gateway, supporting basis RPL protocol simultaneously. Through simulation, we show that the proposed routing scheme with zone based path selection scheme improves the performance of the success rate of end-to-end data transmission and the end-to-end delay, compared to basis RPL protocol.

An Analysis of Detection of Malicious Packet Dropping and Detour Scheme in IoT based on IPv6 (IPv6 기반의 사물인터넷 환경에서 악성 노드의 패킷 유실 공격 탐지 및 우회 기법 분석)

  • Choi, Jaewoo;Kwon, Taekyoung
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.26 no.3
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    • pp.655-659
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    • 2016
  • In this paper, we propose new detection and detour methods against packet drop attacks for availability in the Internet of Things (IoT) based on the IEEE 802.15.4e and RPL protocol standards that employ IPv6. We consider the rank value of RPL and the consecutive packet drops to improve the detection metrics, and also take into account the use of both sibling and child nodes on a RPL routing path to construct the detour method. Our simulation results show that the proposed detection method is faster than the previous result, and the detour method improves the detour success rate.

Anti-Cancer Activity of the Leave Extracts of Rodgersia podophylla through β-catenin Proteasomal Degradation in Human Cancer Cells (도깨비부채(Rodgersia podophylla) 잎 추출물의 인간 암세포의 β-catenin 분해 유도 활성)

  • Kim, Ha Na;Kim, Jeong Dong;Son, Ho-Jun;Park, Gwang Hun;Eo, Hyun Ji;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.32 no.5
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    • pp.442-447
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    • 2019
  • In this study, we evaluated the effect of Rodgersia podophylla leave extracts (RPL) on ${\beta}-catenin$ level in human cancer cells. RPL dose-dependently inhibited cell proliferation in SW480, A549, MDA-MB-231, PC-3 and AsPC-1 cells. RPL dramatically decreased ${\beta}-catenin$ protein level in all cancer cells. However, decreased level of ${\beta}-catenin$ mRNA expression was observed in A549 and AsPC-1 cells. In addition, RPL dramatically attenuated cyclin D1 mRNA expression in all cancer cells. MG132 decreased the downregulation of ${\beta}-catenin$ protein level induced by RPL in all cancer cells, while RPL-induced downregulation of ${\beta}-catenin$ was inhibited by the inhibition of $GSK-3{\beta}$ by LiCl in MDA-MB-231 cells. RPL phosphorylated ${\beta}-catenin$ and $GSK-3{\beta}$. In addition, the inhibition of $GSK-3{\beta}$ by LiCl attenuated RPL-induced ${\beta}-catenin$ phosphorylation. Based on these findings, RPL may be a potential candidate for the development of chemopreventive or therapeutic agents for human cancer.