• Title/Summary/Keyword: Epidemic

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k-hop Flooding-based Multicast Considering the Limited Mobility of Mobile Nodes and Intermittent Disconnection (노드의 제한적 이동성과 간헐적인 연결 단절을 고려한 k-홉 플러딩 기반 멀티캐스트)

  • Im, Kwang-Bin;Kang, Kyung-Ran;Cho, Young-Jong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.6A
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    • pp.600-610
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    • 2010
  • In this paper, a multicast mechanism is proposed for intermittently disconnected networks where the nodes move forward in formation or within a limited area. The proposed scheme extends the well-known tree-based multicast routing mechanism called MAODV by modifying the tree construction and data delivery scheme. Especially, an algorithm is introduced which determines the flooding hop count k estimating the degree of the movement of children in the tree. The performance evaluation was done by the simulation and the proposed scheme was compared with MAODV and two multicast routing schemes for DTN (Disruption Tolerant Network) including the Epidemic routing and ST-multicast. The evaluation results show that our scheme improves the original MAODV from the aspect of tree reconstruction events and message delivery ratio. Compared with the Epidemic routing scheme, our scheme achieves 85% message delivery ratio with less than 50% message delivery overhead.

Traditional Unani Medicine in Flu-like Epidemics and COVID-19 during Pregnancy: A Literary Research

  • Sultana, Arshiya;Khanam, Marhaba;Rahman, Khaleequr;Sumbul, Sumbul
    • CELLMED
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    • v.11 no.4
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    • pp.20.1-20.23
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    • 2021
  • Background: The pandemic COVID-19 caused by a novel coronavirus SARS-COV-2 has spread like a forest fire. This disease may have serious consequences for pregnant women. Presently, no specific drugs or vaccines exist to battle this disease and researches are underway. Unani medicine has a unique role in prevention and management during epidemics. Here, we reviewed the overview of COVID-19 infection and pregnancy, concept and practices in Unani medicine for flu-like epidemics in general and pregnancy, and safety of Unani drugs for the prevention and treatment of mild symptomatic cases of COVID-19 during pregnancy. Methodology: Unani classical texts and pharmacopoeia were meticulously explored for concepts and practices for flu-like epidemic diseases. Further, we browsed scientific databases such as PubMed, Scopus and others for an overview, epidemics and Unani medicine, effectiveness and safety of Unani drugs in COVID-19 and pregnancy. Results: Unani medicine includes prevention and management of flu-like epidemic include quarantine and isolation, aromatic herbal drugs fumigation and spraying for environmental disinfection, ilaj bid tadbir for health promotion and use of health-protecting drugs and symptom-specific drugs in general and related to pregnancy. Lahsun, asalussus, behidana, banafsha, zanjabeel, unnab, etc are in use since antiquity for the prevention and treatment of asymptomatic and mildly symptomatic pregnant women during infectious and epidemic diseases. Conclusion: Currently, the aforementioned plants are proven for antiviral, antioxidant, immunomodulatory and anti-inflammatory activities, probably useful in the COVID-19 pandemic. Additionally, scientific studies have provided new insight into the mechanism underlying the therapeutic effect of Unani medicines that are safe in pregnancy.

Evaluation of virulence reversion of an attenuated porcine epidemic diarrhea vaccine strain by serial passages in suckling piglets

  • Da-Jeong Kim;Seung-Chai Kim;Hwan-Ju Kim;Gyeong-Seo Park;Sang Chul Kang;Won-Il Kim
    • Korean Journal of Veterinary Service
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    • v.46 no.3
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    • pp.193-202
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    • 2023
  • Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.

Porcine epidemic diarrhea virus: an update overview of virus epidemiology, vaccines, and control strategies in South Korea

  • Guehwan Jang;Duri Lee;Sangjune Shin;Jeonggyo Lim;Hokeun Won;Youngjoon Eo;Cheol-Ho Kim;Changhee Lee
    • Journal of Veterinary Science
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    • v.24 no.4
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    • pp.58.1-58.25
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    • 2023
  • Porcine epidemic diarrhea virus (PEDV) has posed significant financial threats to the domestic pig industry over the last three decades in South Korea. PEDV infection will mostly result in endemic persistence in the affected farrow-to-finish (FTF) herds, leading to endemic porcine epidemic diarrhea (PED) followed by year-round recurrent outbreaks. This review aims to encourage collaboration among swine producers, veterinarians, and researchers to offer answers that strengthen our understanding of PEDV in efforts to prevent and control endemic PED and to prepare for the next epidemics or pandemics. We found that collaboratively implementing a PED risk assessment and customized four-pillar-based control measures is vital to interrupt the chain of endemic PED in affected herds: the former can identify on-farm risk factors while the latter aims to compensate for or improve weaknesses via herd immunity stabilization and virus elimination. Under endemic PED, long-term virus survival in slurry and asymptomatically infected gilts ("Trojan Pigs") that can transmit the virus to farrowing houses are key challenges for PEDV eradication in FTF farms and highlight the necessity for active monitoring and surveillance of the virus in herds and their environments. This paper underlines the current knowledge of molecular epidemiology and commercially available vaccines, as well as the risk assessment and customized strategies to control PEDV. The intervention measures for stabilizing herd immunity and eliminating virus circulation may be the cornerstone of establishing regional or national PED eradication programs.

Retrospective study of porcine epidemic diarrhea in Korea by in situ hybridization (In situ hybridization에 의한 돼지 유행성 설사증의 국내발생 역추적 진단)

  • Park, Nam-yong;Lee, Seok-yun
    • Korean Journal of Veterinary Research
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    • v.37 no.4
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    • pp.809-816
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    • 1997
  • In this presented study, we established a method for diagnosis of porcine epidemic diarrhea(PED) by in situ hybridization(ISH), which made distinct progress in diagnostic pathology. We also carried out the retrospective diagnosis through ISH to assume the exact time of the first outbreak and incidence of PED in Korea. The outbreak of PED in Korea reported in 1992. However, since the end of 1980's, some researches of pig-industry have already suspected the outbreak of PED, not transmissible gastroenteritis(TGE). In this experiment, we performed the ISH using 80 formalin-fixed and paraffin-embedded tissues of porcine intestine which were requests for pathological diagnosis from 63 farms whose primary sign was diarrhea from 1984 to 1991. We prepared biotinylated cDNA probe(492base pairs) for ISH by nick translation method and carried out the ISH, using $Microprobe^{TM}$ capillary action system(Fisher $Biotech^R$). We detected PED virus in intestinal mucosa of 2 cases in 1992, 1 case in 1988, and 1 case in 1987. As a result, we assume that the outbreak of PED in Korea have already started since 1987.

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Effect of Arachidonic Acid on Production of Laminin and Connexin of Granulosa Cells from Chicken Pre-hierarchical Follicles

  • Jin, Yanmei;Tan, Tu Quang;Zhang, Caiqiao
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.3
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    • pp.350-355
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    • 2009
  • Arachidonic acid (AA) is a polyunsaturated fatty acid that is a normal constituent of membrane lipids in animal cells. In addition to its role as a precursor of prostaglandins, AA itself may play an important role in the regulation of cell function. The effect of AA on functions of granulosa cells was investigated in pre-hierarchical small yellow follicles of laying hens. Immuno-cytochemical staining showed that AA ($10^{-7}-10^{-5}$ M) increased the expression of the extracellular matrix glycoprotein laminin, gap junction connexin 43 and protein kinase C (PKC). Therefore, mediated by the PKC signal pathway, AA may regulate the intercellular communication of granulosa cells and follicular development by increasing the expression of laminin and connexin.

A study of the Office for Saving Lives (活人署), a government office in the Joseon, through its history and use of a standing prescription (조선 시대 활인서 연구 - 연혁 및 상비처방을 중심으로)

  • Park, Hun-Pyeong
    • The Journal of Korean Medical History
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    • v.33 no.1
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    • pp.11-20
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    • 2020
  • The Office for Saving Lives (活人署) (OSL) was the office in charge of the treatment and relief of the poor in the Joseon Dynasty. This study disputes prior scholarship on the OSL by analyzing the use of a ready-made prescription and by focusing on the personality of the OSL's medical institutions. The work of the three government offices, the Office of Great Mercy (大悲院) (OGM), which was the formal office of OSL, the Office of Benefiting People (惠民署) and the Office of Aiding Life (濟生院), overlapped in the area of relief of the common people. But OGM was different from the other two in that it was not a purely medical office, had no educational function, and did not manage medicine. By analyzing a standing prescription, this article argues: 1) Heojun's influence on the composition of a standing prescription is absolute. 2) Epidemic warm disease (溫疫) was a major social problem in terms of emergency medical care at the time. 3) In the late Joseon Dynasty, the treatment of epidemic warm diseases became more sophisticated than the previous era.

Epidemic Outbreak of Blast Disease in the Resistant Variety of Rice, 'Kwanok' (저항성품종인 '관옥'의 도열병 격발원인)

  • Lee E. C.
    • Korean journal of applied entomology
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    • v.11 no.1
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    • pp.41-43
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    • 1972
  • 1. In order to investigate the epidemic outbreak of rice blast disease on the resistant variety Kwankon in 1969, this investigation was undertaken as a basis for breeding resistant varieties. 2. The 16 isolates collected from Kyunggi area were inoculated at the 3-4 leaf stage on 12 Japanese differential varieties used for identifying races under greenhouse conditions. Out of 16 isolates 15 were identified as C race group and one as N race group. Of the 15 rates, nine were C-8, two were C-7 and two were C-1. Of the remaining two isolates, one was similar to C-1, and the other was similar to C-5. 3. It is concluded that the epidemic in the resistant variety 'Kwanok' was due to the occurrence of the C race group, which can infect the Chinese type varieties.

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Epidemiological Concepts and Strategies in Breeding Soybeans for Disease Resistance

  • Seung Man, Lim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.35 no.1
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    • pp.97-107
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    • 1990
  • The epidemiology of plant disease deals with the dynamic processes of host-pathogen interactions, which determine the prevalence and severity of the disease. Epidemic processes for most foliar diseases of plants follow a series of steps: arrival of pathogens on plant surfaces, initial infection, incubation period, latent period, sporulation, dissemination of secondary inoculum, and infectious period. These complex biological processes are influenced by the environment-Man also often interfers with these processes by altering the host and pathogen populations and the environment. Slowing or halting any of the epidemic processes can delay the development of the epidemic, so that serious losses in yield due to disease do not occur. It is generally recognized that the most effective and efficient method of minimizing disease damage is through the use of resistant cultivars, particularly when other methods such as fungicide applications are not economically feasible-Populations of plant pathogens are not genetically uniform nor are they necessarily stable. Cultivars bred for resistance to current populations of a pathogen may not be resistant in the future due to selection pressures placed on the pathogen populations. Understanding population development and genetic variability in the pathogen, and knowledge of the genetics of resistance in the plant should help in developing breeding strategies that wi1l provide effective and stable disease control through genetic resistance. In the United States, soybeans have ranked first in value of crops sold off the farm in recent years. Soybeans have been the leading U. S.

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Seasonal Prevalence and Abundance of Mosquitoes at the Busan Port (2001~2006)

  • Kim, Mi-Kyeong;Lee, Eun-Ju
    • Korean Journal of Clinical Laboratory Science
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    • v.44 no.4
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    • pp.199-204
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    • 2012
  • The purpose of this study is to examine the population density of the mosquito species, and to provide the basic data related to vector mosquitoes to manage the possible epidemic diseases. During a 4-year investigation (2001, 2002, 2004, and 2006), we collected the specimens of the mosquitoes at pier no. 1, 3 and 5 of Busan port with light traps from sunset until the next day morning from April to October each year. Through the research, we collected 5,985 mosquito specimens in total and found 7 mosquito species belonging to 3 genera. A total of 1,575, 1,473, 1,478 and 1,459 mosquito specimens were collected in 2001, 2002, 2004 and 2006, respectively. Among them, 5,568 (93.0%) specimens were Culex pipiens pallens, the West Nile virus infection vector, which showed the highest density among the specimens. The population densities of the other species were: 295(4.9%) Culex tritaeniorhynchus, 94(1.5%) Aedes togoi, 12(0.3%) Aedes albopictus, 10(0.2%) Anopheles sinensis, 4(0.1%) Aedes vexans nipponii, 2(0.1%) Culex inatomii. The monthly abundance of mosquitoes from July through September showed the highest values. Although it was a general mosquito monitoring study, this study could provide a base for securing the statistical data on spreading epidemic diseases by people infected outside Korea.

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