• Title/Summary/Keyword: Defenses

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Endodontic biofilms: contemporary and future treatment options

  • Yoo, Yeon-Jee;Perinpanayagam, Hiran;Oh, Soram;Kim, A-Reum;Han, Seung-Hyun;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.44 no.1
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    • pp.7.1-7.10
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    • 2019
  • Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

Urban Impermanence on the Southern Malay Peninsula: The Case of Batu Sawar Johor (1587-c.1615)

  • Borschberg, Peter
    • Journal of East-Asian Urban History
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    • v.3 no.1
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    • pp.57-82
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    • 2021
  • This article examines the urban example of Batu Sawar which served as the capital of the Johor kingdom between 1587 and circa 1615. Around the middle of the eighteenth-century European reference works continued to describe Batu Sawar as the capital of Johor, even though the city had long ceased to serve as a trading center, let alone as Johor's capital, and probably no longer existed. Such observations raise the question of urban impermanence-the transience of sizeable settlements with reference to the Malay Archipelago. Two overarching questions form the backbone of the investigation: First, why did Batu Sawar rise as a regional trading center, and second, what are the reasons that contributed to its decline? Batu Sawar's fate was sealed by a combination of factors that included poor defenses, multiple external shocks, destruction by fire, court politics and rivalry between the early colonial powers.

A Study Adversarial machine learning attacks and defenses (적대적 머신러닝 공격과 방어기법)

  • jemin Lee;Jae-Kyung Park
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2023.07a
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    • pp.621-623
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    • 2023
  • 본 논문에서는 기계 학습 모델의 취약점과 대응책에 초점을 맞추어 적대적인 기계 학습 공격 및 방어 분야를 탐구한다. 신중하게 만들어진 입력 데이터를 도입하여 기계 학습 모델을 속이거나 조작하는 것을 목표로 하는 적대적 공격에 대한 심층 분석을 제공한다. 이 논문은 회피 및 독성 공격을 포함한 다양한 유형의 적대적 공격을 조사하고 기계 학습 시스템의 안정성과 보안에 대한 잠재적 영향을 조사한다. 또한 적대적 공격에 대한 기계 학습 모델의 견고성을 향상시키기 위해 다양한 방어 메커니즘과 전략을 제안하고 평가한다. 본 논문은 광범위한 실험과 분석을 통해 적대적 기계 학습에 대한 이해에 기여하고 효과적인 방어 기술에 대한 통찰력을 제공하는 것을 목표로 한다.

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Survey of the Model Inversion Attacks and Defenses to ViT (ViT 기반 모델 역전 공격 및 방어 기법들에 대한 연구)

  • Miseon Yu;Yunheung Peak
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.05a
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    • pp.15-17
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    • 2023
  • ViT(Vision Transformer)는 트랜스포머 구조에 이미지를 패치들로 나눠 한꺼번에 인풋으로 입력하는 모델이다. CNN 기반 모델보다 더 적은 훈련 계산량으로 다양한 이미지 인식 작업에서 SOTA(State-of-the-art) 성능을 보이면서 다양한 비전 작업에 ViT 를 적용하는 연구가 활발히 진행되고 있다. 하지만, ViT 모델도 AI 모델 훈련시에 생성된 그래디언트(Gradients)를 이용해 원래 사용된 훈련 데이터를 복원할 수 있는 모델 역전 공격(Model Inversion Attacks)에 안전하지 않음이 증명되고 있다. CNN 기반의 모델 역전 공격 및 방어 기법들은 많이 연구되어 왔지만, ViT 에 대한 관련 연구들은 이제 시작 단계이고, CNN 기반의 모델과 다른 특성이 있기에 공격 및 방어 기법도 새롭게 연구될 필요가 있다. 따라서, 본 연구는 ViT 모델에 특화된 모델 역전 공격 및 방어 기법들의 특징을 서술한다.

Host-Pathogen Interactions Operative during Mycobacteroides abscessus Infection

  • Eun-Jin Park;Prashanta Silwal;Eun-Kyeong Jo
    • IMMUNE NETWORK
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    • v.21 no.6
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    • pp.40.1-40.20
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    • 2021
  • Mycobacteroides abscessus (previously Mycobacterium abscessus; Mabc), one of rapidly growing nontuberculous mycobacteria (NTM), is an important pathogen of NTM pulmonary diseases (NTM-PDs) in both immunocompetent and immunocompromised individuals. Mabc infection is chronic and often challenging to treat due to drug resistance, motivating the development of new therapeutics. Despite this, there is a lack of understanding of the relationship between Mabc and the immune system. This review highlights recent progress in the molecular architecture of Mabc and host interactions. We discuss several microbial components that take advantage of host immune defenses, host defense pathways that can overcome Mabc pathogenesis, and how host-pathogen interactions determine the outcomes of Mabc infection. Understanding the molecular mechanisms underlying host-pathogen interactions during Mabc infection will enable the identification of biomarkers and/or drugs to control immune pathogenesis and protect against NTM infection.

Effectiveness and Ecological Implications of Anuran Defenses against Snake Predators

  • In-Ho Choi;Sung Ho Lee;Robert E. Ricklefs
    • Animal cells and systems
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    • v.3 no.3
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    • pp.247-252
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    • 1999
  • The aim of this study was to characterize antipredator tactics of anurans and to evaluate the effectiveness of these tactics for predator avoidance in real confrontations. Two types of experiments were conducted. In one experiment, one predator and one prey were placed together for one hour in a small confined space (one-to-one interaction). In another experiment, one predator and several prey were placed together for one day in a large enclosure in a field (field-based interaction). The prey consisted of three anuran species, Rana nigromaculata, R. rugosa, and Bombina orientalls: a snake species, Rhabdophis tigrinus tigrinus, was used as a predator. Results of both experiments demonstrated a range in antipredator responses of the frogs, from toxicity and warning coloration, coupled with slow responses in Bombina to little (or only slight) toxicity, crypsis, and fast take-off responses to the predator in the ranids. oth ranid species exhibited lower survival(57%) than Bombina (95%) in the field-based interaction, suggesting that motor responses of the palatable prey due to attacks of the predator ultimately limited their survival. The jumping of the ranids increased the activity of the predator, which became more likely to strike. Simple crouching(seen in R. rugosa and B. orientalis) and chemical defense (in Bombina) reduced predatory attacks.

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Probiotic Functional Dairy Foods and Health Claims: an Overview

  • Jayaprakasha, Heddur M.;Yoon, Yoh-Chang;Paik, Hyun-Dong
    • Food Science and Biotechnology
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    • v.14 no.4
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    • pp.523-528
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    • 2005
  • The commercial interests in functional foods containing probiotics are gaining significance in view of increasing studies on their role in digestive tract. Probiotic dairy foods containing health-promoting bacteria are important segment of functional food market. Various health benefits have been attributed to specific strains of lactic acid bacteria or food containing these probiotic cultures. Probiotic-containing foods are considered to improve general gut health and natural defenses of body, and lower blood cholesterol level. Specific probiotic microbes can alleviate or prevent diverse intestinal diarrhea-inducing disorders, cause prophylaxis of intestinal and urogenital infections, inhibit mutagenicity of intestinal contents, and reduce incidence of intestinal tumors. Recent increasing evidences on health effects of probiotics have triggered consumer interest in this category of functional foods. Rational approach needs to be applied in selection of strains for probiotic preparation to achieve required functionality. Present article focuses on some prominent probiotic candidates and criteria for their inclusion in functional food sector. Various health claims of probiotics on gastrointestinal disorders, anticarcinogenic effects, and anti-cholestrimic effects, and possible mechanistic explanations for their functionality are highlighted.

Novel Therapeutic Approach toward Inflammatory Diseases: Targeting Transglutaminase 2

  • Kim Soo-Youl;Kim Hong-Yeoul;Lee Jae-Dong
    • The Journal of Korean Medicine
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    • v.25 no.4
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    • pp.188-199
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    • 2004
  • Transglutaminase 2 (TGase 2) is an enzyme that is widely used in many biological systems for generic tissue stabilization purposes or immediate defenses for wounds. Many reports have showed that TGase 2 is aberrantly activated in tissues and cells and contributes to a variety of diseases, including neurodegenerative diseases and autoimmune diseases. In most cases, the TGase 2 appears to be a factor in the formation of inappropriate proteinaceous aggregates that may be cytotoxic. However, in other cases such as celiac disease, arthritis, lupus, amyotrophic lateral sclerosis, TGase 2 is involved in the generation of autoantibodies. This suggests the possibility that the inappropriate expression and/or presentation of TGase 2 to T cells might contribute to these diseases in genetically predisposed individuals. Others and we have found that TGase 2 expression is also increased in the inflammation process. We also demonstrated reverse of inflammation by TGase inhibition. Furthermore we discovered the genuine role of TGase 2 in immune cell activation. Increase of TGase activity induces or exacerbates inflammation via NF-κB activation without I-κBα kinase signalings. This review will examine a possibility of TGase inhibitors as therapeutic agents in a variety of inflammatory diseases.

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Microbe-Based Plant Defense with a Novel Conprimycin Producing Streptomyces Species

  • Kwak, Youn-Sig
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.54-54
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    • 2015
  • Crops lack genetic resistance to most necrotrophic soil-borne pathogens and parasitic nematodes that are ubiquitous in agroecosystems worldwide. To overcome this disadvantage, plants recruit and nurture specific group of antagonistic microorganisms from the soil microbiome to defend their roots against pathogens and other pests. The best example of this microbe-based defense of roots is observed in disease-suppressive soils in which the suppressiveness is induced by continuously growing crops that are susceptible to a pathogen. Suppressive soils occur globally yet the microbial basis of most is still poorly described. Fusarium wilt, caused by Fusarium oxysporum f. sp. fragariae is a major disease of strawberry and is naturally suppressed in Korean fields that have undergone continuous strawberry monoculture. Here we show that members of the genus Streptomyces are the specific bacterial components of the microbiome responsible for the suppressiveness that controls Fusarium wilt of strawberry. Furthermore, genome sequencing revealed that Streptomyces griseus, which produces a novel thiopetide antibiotic, is the principal species involved in the suppressiveness. Finally, chemical-genetic studies demonstrated that S. griseus antagonizes F. oxysporum by interfering with fungal cell wall synthesis. An attack by F. oxysporum initiates a defensive "cry for help" by strawberry root and the mustering of microbial defenses led by Streptomyces. These results provide a model for future studies to elucidate the basis of microbially-based defense systems and soil suppressiveness from the field to the molecular level.

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Potential Implications and Applications of Terror Management Theory for Library and Information Science

  • Hollister, Jonathan M.;Lee, Jisue;Elkins, Aaron J.;Latham, Don
    • Journal of the Korean Society for Library and Information Science
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    • v.54 no.4
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    • pp.317-349
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    • 2020
  • Mental health experts warn the combination of overwhelming amounts of information, economic instability, political discontent, social injustice, and the high infection and death rates of the ongoing COVID-19 pandemic are negatively impacting mental health in ways that may worsen the pandemic and intensify our primal fear of death. Terror Management Theory (TMT) argues that self-esteem and cultural worldviews serve as defenses against the terror of our own mortality. This theory anchor paper introduces TMT to Library and Information Science (LIS) via a selected literature review on TMT's use in the field of Psychology and an extensive discussion on the conceptual connections to LIS supported with empirical research from related disciplines and contexts. The implications, applications, and usefulness of TMT for LIS research, education, and practice are discussed in relation to the COVID-19 pandemic and other contexts, and a research agenda is proposed.