• Title/Summary/Keyword: Protection mechanisms

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Revisiting Managerial Ownership and Firm Value in the Absence of Market Forces: Evidence from Singapore and Thailand

  • POLWITOON, Sirapat;TAWATNUNTACHAI, Oranee
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.1-13
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    • 2020
  • This study examines the effect of managerial ownership on firm value in capital markets where outside governance mechanisms to discipline managers are weak or non-existent. We hypothesize that strong market forces in the U.S. confound the effect of managerial ownership on firm value, i.e., the convergence of interest argument. We test the hypothesis using data from 112 firms from Singapore Stock Exchange and 205 firms from the Stock Exchange of Thailand prior to the Asian financial crisis in 1997 when the market forces were weak, yet the investor protection was sufficient to prevent outright appropriation from management. For ease of comparison, we use methodologies from studies done on the U.S. sample firms during the same study period as ours. We find that, both in Singapore and Thailand, firm value is a function of managerial ownership, and the relation is of the famous inverted U-shaped. Moreover, the relation is robust under different model specifications. The results from Thai sample, with weaker market forces than in Singapore, lend support to many agency cost hypotheses advanced in the U.S. Our results provide useful implication for investors in emerging and frontier markets where outside governance mechanisms are yet to be fully developed.

Experimental Verification of Induction Phenomenon on Telecommunication Lines by Applying Its Occurrence Mechanisms Using an Artificial ELF Source Generator

  • Lee, Sang-Mu;Gimm, Yoon-Myoung;Eun, Chang-Soo
    • Journal of electromagnetic engineering and science
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    • v.10 no.4
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    • pp.276-281
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    • 2010
  • In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.

Dry storage of spent nuclear fuel and high active waste in Germany-Current situation and technical aspects on inventories integrity for a prolonged storage time

  • Spykman, Gerold
    • Nuclear Engineering and Technology
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    • v.50 no.2
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    • pp.313-317
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    • 2018
  • Licenses for the storage of spent nuclear fuel (SNF) and vitrified highly active waste in casks under dry conditions are limited to 40 years and have to be renewed for prolonged storage periods. If such a license renewal has to be expected since as in accordance with the new site selection procedure a final repository for spent fuel in Germany will not be available before the year 2050. For transport and possible unloading and loading in new casks for final storage, the integrity and the maintenance of the geometry of the cask's inventory is essential because the SNF rod cladding and the cladding of the vitrified highly active waste are stipulated as a barrier in the storage concept. For SNF, the cladding integrity is ensured currently by limiting the hoop stress and hoop strain as well as the maximum temperature to certain values for a 40-year storage period. For a prolonged storage period, other cladding degradation mechanisms such as inner and outer oxide layer formation, hydrogen pick up, irradiation damages in cladding material crystal structure, helium production from alpha decay, and long-term fission gas release may become leading effects driving degradation mechanisms that have to be discussed.

Security Threats and Attacks in Internet of Things (IOTs)

  • Almtrafi, Sara Mutlaq;Alkhudadi, Bdour Abduallatif;Sami, Gofran;Alhakami, Wajdi
    • International Journal of Computer Science & Network Security
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    • v.21 no.1
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    • pp.107-118
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    • 2021
  • The term Internet of Things (IoTs) refers to the future where things are known daily through the Internet, whether in one way or another, as it is done by the method of collecting various information from various sensors to form a huge network through which people, things and machines are helped to make a link between them at all time and anywhere. The IoTs is everywhere around us such as connected appliances, smart homes security systems and wearable health monitors. However, the question is what if there is a malfunction or outside interference that affects the work of these IoTs based devises? This is the reason of the spread of security causes great concern with the widespread availability of the Internet and Internet devices that are subject to many attacks. Since there aren't many studies that combines requirements, mechanisms, and the attacks of the IoTs, this paper which explores recent published studies between 2017 and 2020 considering different security approaches of protection related to the authentication, integrity, availability and confidentiality Additionally, the paper addresses the different types of attacks in IoTs. We have also addressed the different approaches aim to prevention mechanisms according to several researchers' conclusions and recommendations.

Notoginseng leaf triterpenes ameliorates mitochondrial oxidative injury via the NAMPT-SIRT1/2/3 signaling pathways in cerebral ischemic model rats

  • Weijie, Xie;Ting, Zhu;Ping, Zhou;Huibo, Xu;Xiangbao, Meng;Tao, Ding;Fengwei, Nan;Guibo, Sun;Xiaobo, Sun
    • Journal of Ginseng Research
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    • v.47 no.2
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    • pp.199-209
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    • 2023
  • Background: Due to the interrupted blood supply in cerebral ischemic stroke (CIS), ischemic and hypoxia results in neuronal depolarization, insufficient NAD+, excessive levels of ROS, mitochondrial damages, and energy metabolism disorders, which triggers the ischemic cascades. Currently, improvement of mitochondrial functions and energy metabolism is as a vital therapeutic target and clinical strategy. Hence, it is greatly crucial to look for neuroprotective natural agents with mitochondria protection actions and explore the mediated targets for treating CIS. In the previous study, notoginseng leaf triterpenes (PNGL) from Panax notoginseng stems and leaves was demonstrated to have neuroprotective effects against cerebral ischemia/reperfusion injury. However, the potential mechanisms have been not completely elaborate. Methods: The model of middle cerebral artery occlusion and reperfusion (MCAO/R) was adopted to verify the neuroprotective effects and potential pharmacology mechanisms of PNGL in vivo. Antioxidant markers were evaluated by kit detection. Mitochondrial function was evaluated by ATP content measurement, ATPase, NAD and NADH kits. And the transmission electron microscopy (TEM) and pathological staining (H&E and Nissl) were used to detect cerebral morphological changes and mitochondrial structural damages. Western blotting, ELISA and immunofluorescence assay were utilized to explore the mitochondrial protection effects and its related mechanisms in vivo. Results: In vivo, treatment with PNGL markedly reduced excessive oxidative stress, inhibited mitochondrial injury, alleviated energy metabolism dysfunction, decreased neuronal loss and apoptosis, and thus notedly raised neuronal survival under ischemia and hypoxia. Meanwhile, PNGL significantly increased the expression of nicotinamide phosphoribosyltransferase (NAMPT) in the ischemic regions, and regulated its related downstream SIRT1/2/3-MnSOD/PGC-1α pathways. Conclusion: The study finds that the mitochondrial protective effects of PNGL are associated with the NAMPT-SIRT1/2/3-MnSOD/PGC-1α signal pathways. PNGL, as a novel candidate drug, has great application prospects for preventing and treating ischemic stroke.

Distribution and Determinants of Out-of-pocket Healthcare Expenditures in Bangladesh

  • Mahumud, Rashidul Alam;Sarker, Abdur Razzaque;Sultana, Marufa;Islam, Ziaul;Khan, Jahangir;Morton, Alec
    • Journal of Preventive Medicine and Public Health
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    • v.50 no.2
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    • pp.91-99
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    • 2017
  • Objectives: As in many low-income and middle-income countries, out-of-pocket (OOP) payments by patients or their families are a key healthcare financing mechanism in Bangladesh that leads to economic burdens for households. The objective of this study was to identify whether and to what extent socioeconomic, demographic, and behavioral factors of the population had an impact on OOP expenditures in Bangladesh. Methods: A total of 12 400 patients who had paid to receive any type of healthcare services within the previous 30 days were analyzed from the Bangladesh Household Income and Expenditure Survey data, 2010. We employed regression analysis for identify factors influencing OOP health expenditures using the ordinary least square method. Results: The mean total OOP healthcare expenditures was US dollar (USD) 27.66; while, the cost of medicines (USD 16.98) was the highest cost driver (61% of total OOP healthcare expenditure). In addition, this study identified age, sex, marital status, place of residence, and family wealth as significant factors associated with higher OOP healthcare expenditures. In contrary, unemployment and not receiving financial social benefits were inversely associated with OOP expenditures. Conclusions: The findings of this study can help decision-makers by clarifying the determinants of OOP, discussing the mechanisms driving these determinants, and there by underscoring the need to develop policy options for building stronger financial protection mechanisms. The government should consider devoting more resources to providing free or subsidized care. In parallel with government action, the development of other prudential and sustainable risk-pooling mechanisms may help attract enthusiastic subscribers to community-based health insurance schemes.

Current Evidence on the Association between rs3757318 of C6orf97 and Breast Cancer Risk: a Meta-Analysis

  • Hong, Yuan;Chen, Xue-Qin;Li, Jiao-Yuan;Liu, Cheng;Shen, Na;Zhu, Bei-Bei;Gong, Jing;Chen, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8051-8055
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    • 2014
  • Background: A common genetic variant rs3757318, located in intron of C6orf97, was firstly identified to be associated with breast cancer (BC) risk by a genome-wide association (GWA) study. However, subsequent validation studies with different ethnicities have yielded conflicting results. Materials and Methods: We performed a meta-analysis to synthesize all available data for evaluating the precise effect of this variant on BC susceptibility. Results: A total of 8 articles containing 11 studies with 62,891 cases and 65,635 controls were included in this meta-analysis. When compared to the G allele, the rs3757318-A allele was significantly associated with BC risk with the pooled OR of 1.21 (95% CI=1.15 - 1.29, P<0.001) but with obvious between-study heterogeneity (P=0.040). Stratified analysis suggested that diversity of ethnicity along with control source may explain part of the heterogeneity. Similarly, significant associations were also identified in heterozygote, homozygote, dominant and recessive genetic models. Sensitivity and publication bias analyses indicated robust stability of our results. Conclusions: Our present meta-analysis demonstrated that the variant rs3757318 is associated with increased BC risk. Nevertheless, further studies are needed to clarify the underlying biological mechanisms.

Mitochondrial OXPHOS genes provides insights into genetics basis of hypoxia adaptation in anchialine cave shrimps

  • Guo, Huayun;Yang, Hao;Tao, Yitao;Tang, Dan;Wu, Qiong;Wang, Zhengfei;Tang, Boping
    • Genes and Genomics
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    • v.40 no.11
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    • pp.1169-1180
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    • 2018
  • Cave shrimps from the genera Typhlatya, Stygiocaris and Typhlopatsa (TST complex) comprises twenty cave-adapted taxa, which mainly occur in the anchialine environment. Anchialine habitats may undergo drastic environmental fluctuations, including spatial and temporal changes in salinity, temperature, and dissolved oxygen content. Previous studies of crustaceans from anchialine caves suggest that they have possessed morphological, behavioral, and physiological adaptations to cope with the extreme conditions, similar to other cave-dwelling crustaceans. However, the genetic basis has not been thoroughly explored in crustaceans from anchialine habitats, which can experience hypoxic regimes. To test whether the TST shrimp-complex hypoxia adaptations matched adaptive evolution of mitochondrial OXPHOS genes. The 13 OXPHOS genes from mitochondrial genomes of 98 shrimps and 1 outgroup were examined. For each of these genes was investigated and compared to orthologous sequences using both gene (i.e. branch-site and Datamonkey) and protein (i.e. TreeSAAP) level approaches. Positive selection was detected in 11 of the 13 candidate genes, and the radical amino acid changes sites scattered throughout the entire TST complex phylogeny. Additionally, a series of parallel/convergent amino acid substitutions were identified in mitochondrial OXPHOS genes of TST complex shrimps, which reflect functional convergence or similar genetic mechanisms of cave adaptation. The extensive occurrence of positive selection is suggestive of their essential role in adaptation to hypoxic anchialine environment, and further implying that TST complex shrimps might have acquired a finely capacity for energy metabolism. These results provided some new insights into the genetic basis of anchialine hypoxia adaptation.

An Access Control Model for Privacy Protection using Purpose Classification (사용목적 분류를 통한 프라이버시 보호를 위한 접근제어 모델)

  • Na Seok-Hyun;Park Seog
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.16 no.3
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    • pp.39-52
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    • 2006
  • Recently purpose is used by an crucial part to security management when collecting data about privacy. The W3C(World Wide Web Consortium) describes a standard spec to control personal data that is provided by data providers who visit the web site. But they don't say anymore about security management about personal data in transit after data collection. Recently several researches, such as Hippocratic Databases, Purpose Based Access Control and Hippocratic in Databases, are dealing with security management using purpose concept and access control mechanism after data collection a W3C's standard spec about data collection mechanism but they couldn't suggest an efficient mechanism for privacy protection about personal data because they couldn't represent purpose expression and management of purposes sufficiently. In this paper we suggest a mechanism to improve the purpose expression. And then we suggest an accesscontrol mechanism that is under least privilege principle using the purpose classification for privacy protection. We classify purpose into Along purpose structure, Inheritance purpose structure and Stream purpose structure. We suggest different mechanisms to deal with then We use the role hierarchy structure of RBAC(Role-Based Access Control) for flexibility about access control and suggest mechanisms that provide the least privilege for processing the task in case that is satisfying using several features of purpose to get least privilege of a task that is a nit of business process.

Host Responses from Innate to Adaptive Immunity after Vaccination: Molecular and Cellular Events

  • Kang, Sang-Moo;Compans, Richard W.
    • Molecules and Cells
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    • v.27 no.1
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    • pp.5-14
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    • 2009
  • The availability of effective vaccines has had the most profound positive effect on improving the quality of public health by preventing infectious diseases. Despite many successful vaccines, there are still old and new emerging pathogens against which there is no vaccine available. A better understanding of how vaccines work for providing protection will help to improve current vaccines as well as to develop effective vaccines against pathogens for which we do not have a proper means to control. Recent studies have focused on innate immunity as the first line of host defense and its role in inducing adaptive immunity; such studies have been an intense area of research, which will reveal the immunological mechanisms how vaccines work for protection. Toll-like receptors (TLRs), a family of receptors for pathogen-associated molecular patterns on cells of the innate immune system, play a critical role in detecting and responding to microbial infections. Importantly, the innate immune system modulates the quantity and quality of long-term T and B cell memory and protective immune responses to pathogens. Limited studies suggest that vaccines which mimic natural infection and/or the structure of pathogens seem to be effective in inducing long-term protective immunity. A better understanding of the similarities and differences of the molecular and cellular events in host responses to vaccination and pathogen infection would enable the rationale for design of novel preventive measures against many challenging pathogens.