• Title/Summary/Keyword: Random Early Detection

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In vitro propagation of oil palm (Elaeis guineensis Jacq.) clones through somatic embryogenesis and analysis of somaclonal variation by RAPD (체세포배발생을 통한 오일팜나무(Elaeis guineensis Jacq.) 클론의 기내증식 및 RAPD를 이용한 체세포변이의 검정)

  • Ahn, In-Suk;Park, Hye-Rim;Son, Sung-Ho
    • Journal of Plant Biotechnology
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    • v.39 no.3
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    • pp.196-204
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    • 2012
  • This study was carried out to develop reliable systems for somatic embryogenesis in oil palm tree (Elaeis guineensis Jacq.), and to verify the somaclonal variants by RAPD analysis. Embryogenic callus was induced successfully on modified half-strength MS medium containing $NaH_2PO_4{\cdot}2H_2O$ and casein. Embryogenic callus was further developed to somatic embryo mass (SEM), which is very hard and bonded tightly each other. Plantlets were proliferated when SEM was cultured on modified MS medium containing half strength $NH_4NO_3$, casein and L-ascorbic acid. Plantlets were transplanted into pots containing artificial soils. When RAPD analysis was conducted using randomly selected 95 in vitro plantlets and 19 random primers, somaclonal variation was detected using BNR35 primer. There was missing band around 1 kb in #22, #28, #35, and #77 plantlets. In addition, bands obtained from #28, #35, and #77 was much stronger than other normal bands. The blast results at NCBI revealed that somaclonal variation observed in this study was related to chloroplast genome of oil palm. The results also revealed that oil palm reproduction system through somatic embryogenesis is quite reliable and early detection of somaclonal variants seem to be possible at in vitro stage by RAPD analysis.

Determinants of Cervical Cancer Screening Uptake in Kurdish Women Living in Western Iran, 2014

  • Aminisani, N;Fattahpour, R;Abedi, L;Shamshirgaran, SM
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.3763-3767
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    • 2016
  • Background: Cervical cancer is the second most common cancer among females across the world. It is a preventable cancer and early detection is very feasible. This study aimed to identify which women characteristics are potentially associated with and may have an important in uence on the uptake of cervical cancer screening in Kurdish women living in the west of Iran.. Materials and Methods: A cross sectional study was conducted in late 2014. A random sample of women aged 40 years and above without history of cervical cancer and identi ed as Kurdish background were selected and interviewed by two trained interviewers. Information about sociodemographic and reproductive factors, history of diseases, and cervical screening was collected using a questionnaire and women who had undergone a hysterectomy were excluded. Univariate analyses were used to describe the general characteristics of the study population. Multivariable logistic regression models with self-reported screening history were used to estimate odds ratios (ORs) with 95% con dence intervals (CI). Signi cance was considered at the 5% level. Results: A total of 561 women were included in this study (mean age $43.6{\pm}5.17$ years) participation in cervical screening at least once was about 32%. Cervical screening uptake percentage was signi cantly lower among people over 60 years of age (adjusted OR= 0.26, 95% CI: 0.11-0.64), and those who were illiterate (OR= 0.41 95% CI: 0.23-0.73) and post-menopausal (OR= 0.56, 95% CI: 0.35-0.91). Women with ${\leq}1$ child were less likely to report a Pap test (adjusted OR=0.43 95%CI: 0.13-1.37) Cervical screening uptake was higher among women with health insurance (OR= 2.31, 95% CI: 1.50-3.56). Conclusions: Cervical screening participation in this study was low compared to other studies in developed countries. The screening uptake was different based on age, education, parity, insurance coverage and menopausal status. It is recommended to target these groups of women in cervical screening program.

Knowledge, Barriers and Attitudes Towards Breast Cancer Mammography Screening in Jordan

  • Abu-Helalah, Munir Ahmad;Alshraideh, Hussam Ahmad;Al-Serhan, Ala-Aldeen Ahmad;Kawaleet, Mariana;Nesheiwat, Adel Issa
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3981-3990
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    • 2015
  • Background: Breast cancer is the most common type of cancer in Jordan. Current efforts are focused on annual campaigns aimed at increasing awareness about breast cancer and encouraging women to conduct mammogram screening. In the absence of regular systematic screening for breast cancer in Jordan, there is a need to evaluate current mammography screening uptake and its predictors, assess women's knowledge and attitudes towards breast cancer and screening mammograms and to identify barriers to this preventive service. Materials and Methods: This cross-sectional study was conducted in six governorates in Jordan through face-to-face interviews on a random sample of women aged 40 to 69 years. Results: A total of 507 participants with mean age of $46.8{\pm}7.8$ years were interviewed. There was low participation rate in early detection of breast cancer practices. Breast self-examination, doctor examination and periodic mammography screening were reported by 34.9%, 16.8% and 8.6% of study participants, respectively. Additionally 3.8% underwent breast cancer screening at least once but not periodically, while 87.6% had never undergone mammography screening. Reported reasons for conducting the screening were: perceived benefit (50%); family history of breast cancer (23.1%); perceived severity (21.2%); and advice from friend or family member (5.8%). City residents have shown higher probability of undergoing mammogram than those who live in towns or villages. Results revealed negative perceptions and limited knowledge of study participants on breast cancer and breast cancer screening. The most commonly reported barriers for women who never underwent screening were: fear of results (63.8%); no support from surrounding environment (59.7); cost of the test (53.4%); and religious belief, i.e. Qadaa Wa Qadar (51.1%). Conclusions: In the absence of regular systematic screening for breast cancer in Jordan, the uptake of this preventive service is very low. It is essential for the country of Jordan to work on applying regular systematic mammography screening for breast cancer. Additionally, there is a need for improvement in the current health promotion programmes targeting breast cancer screening. Other areas that could be targeted in future initiatives in this field include access to screening in rural areas and removal of current barriers.

Active Congestion Control Using Active Router′s Feedback Mechanism (액티브 라우터의 피드백 메커니즘을 이용한 혼잡제어 기법)

  • Choe, Gi-Hyeon;Jang, Gyeong-Su;Sin, Ho-Jin;Sin, Dong-Ryeol
    • The KIPS Transactions:PartC
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    • v.9C no.4
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    • pp.513-522
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    • 2002
  • Current end-to-end congestion control depends only on the information of end points (using three duplicate ACK packets) and generally responds slowly to the network congestion. This mechanism can't avoid TCP global synchronization which TCP congestion window size is fluctuated during congestion occurred and if RTT (Round Trip Time) is increased, three duplicate ACK packets is not a correct congestion signal because congestion maybe already disappeared and the host may send more packets until receive the three duplicate ACK packets. Recently there is increasing interest in solving end-to-end congestion control using active network frameworks to improve the performance of TCP protocols. ACC (Active congestion control) is a variation of TCP-based congestion control with queue management In addition traffic modifications nay begin at the congested router (active router) so that ACC will respond more quickly to congestion than TCP variants. The advantage of this method is that the host uses the information provided by the active routers as well as the end points in order to relieve congestion and improve throughput. In this paper, we model enhanced ACC, provide its algorithm which control the congestion by using information in core networks and communications between active routers, and finally demonstrate enhanced performance by simulation.

TCP Performance Analysis of Packet Buffering in Mobile IP based Networks (모바일 IP 네트워크에서 패킷 버퍼링 방식의 TCP 성능 분석)

  • 허경;노재성;조성준;엄두섭;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5B
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    • pp.475-488
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    • 2003
  • To prevent performance degradation of TCP due to packet losses in the smooth handoff by the route optimization extension of Mobile IP protocol, a buffering of packets at a base station is needed. A buffering of packets at a base station recovers those packets dropped during handoff by forwarding buffered packets at the old base station to the mobile user. But, when the mobile user moves to a congested base station in a new foreign subnetwork, those buffered packets forwarded by the old base station are dropped and TCP transmission performance of a mobile user in the congested base station degrades due to increased congestion by those forwarded burst packets. In this paper, considering the general case that a mobile user moves to a congested base station, we analyze the influence of packet buffering on TCP performance according to handoff arrival distribution for Drop-tail and RED (Random Early Detection) buffer management schemes. Simulation results show that RED scheme can reduce the congestion increased by those forwarded burst packets comparing Drop-Tail, but RED scheme cannot avoid Global Synchronization due to forwarded burst packets by the old base station and new buffer management scheme to avoid it is needed in Mobile IP based networks.

Improving TCP Performance by Implicit Priority Packet Forwarding in Mobile IP based Networks with Packet Buffering (모바일 IP 패킷 버퍼링 방식에서 TCP 성능향상을 위한 암시적인 패킷 포워딩 우선권 보장 방안)

  • 허경;이승법;노재성;조성준;엄두섭;차균현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5B
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    • pp.500-511
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    • 2003
  • To prevent performance degradation of TCP due to packet losses in the smooth handoff by the route optimization extension of Mobile IP protocol, a buffering of packets at a base station is needed. A buffering of packets at a base station recovers those packets dropped during handoff by forwarding buffered packets at the old base station to the mobile user. But, when the mobile user moves to a congested base station in a new foreign subnetwork, those buffered packets forwarded by the old base station are dropped and the wireless link utilization performance degrades due to increased congestion by those forwarded packets. In this paper, considering the case that a mobile user moves to a congested base station in a new foreign subnetwork, we propose an Implicit Priority Packet Forwarding to improve TCP performance in mobile networks. In the proposed scheme, the old base station marks a buffered packet as a priority packet during handoff. In addition, RED (Random Early Detection) at the new congested base station does not include priority packets in queue size and does not drop those packets randomly based on average queue size. Simulation results show that wireless link utilization performance of mobile hosts can be improved without modification to Mobile IP protocol by applying proposed Implicit Priority Packet Forwarding.

A Priority Packet Forwarding for TCP Performance Improvement in Mobile W based Networks with Packet Buffering (모바일 IP 패킷 버퍼링 방식에서 TCP 성능향상을 위한 패킷 포워딩 우선권 보장 방안)

  • Hur, Kyeong;Roh, Young-Sup;Eom, Doo-Seop;Tchah, Kyun-Hyon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.8B
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    • pp.661-673
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    • 2003
  • To prevent performance degradation of TCP due to packet losses in the smooth handoff by the route optimization extension of Mobile IP protocol, a buffering of packets at a base station is needed. A buffering of packets at a base station recovers those packets dropped during handoff by forwarding buffered packets at the old base station to the mobile user. But, when the mobile user moves to a congested base station in a new foreign subnetwork, those buffered packets forwarded by the old base station are dropped and TCP transmission performance of a mobile user in the congested base station degrades due to increased congestion by those forwarded burst packets. In this paper, considering the general case that a mobile user moves to a congested base station, we propose a Priority Packet Forwarding to improve TCP performance in mobile networks. In the proposed scheme, without modification to Mobile IP protocol, the old base station marks a buffered packet as a priority packet during handoff. And priority queue at the new congested base station schedules the priority packet firstly. Simulation results show that proposed Priority Packet Forwarding can improve TCP transmission performance more than Implicit Priority Packet Forwarding and RED (Random Early Detection) schemes.