312 research outputs found
Primary User Emulation Attacks: A Detection Technique Based on Kalman Filter
Cognitive radio technology addresses the problem of spectrum scarcity by
allowing secondary users to use the vacant spectrum bands without causing
interference to the primary users. However, several attacks could disturb the
normal functioning of the cognitive radio network. Primary user emulation
attacks are one of the most severe attacks in which a malicious user emulates
the primary user signal characteristics to either prevent other legitimate
secondary users from accessing the idle channels or causing harmful
interference to the primary users. There are several proposed approaches to
detect the primary user emulation attackers. However, most of these techniques
assume that the primary user location is fixed, which does not make them valid
when the primary user is mobile. In this paper, we propose a new approach based
on the Kalman filter framework for detecting the primary user emulation attacks
with a non-stationary primary user. Several experiments have been conducted and
the advantages of the proposed approach are demonstrated through the simulation
results.Comment: 14 pages, 9 figure
Deep Learning-Based Intrusion Detection System for Advanced Metering Infrastructure
Smart grid is an alternative solution of the conventional power grid which
harnesses the power of the information technology to save the energy and meet
today's environment requirements. Due to the inherent vulnerabilities in the
information technology, the smart grid is exposed to a wide variety of threats
that could be translated into cyber-attacks. In this paper, we develop a deep
learning-based intrusion detection system to defend against cyber-attacks in
the advanced metering infrastructure network. The proposed machine learning
approach is trained and tested extensively on an empirical industrial dataset
which is composed of several attack categories including the scanning, buffer
overflow, and denial of service attacks. Then, an experimental comparison in
terms of detection accuracy is conducted to evaluate the performance of the
proposed approach with Naive Bayes, Support Vector Machine, and Random Forest.
The obtained results suggest that the proposed approaches produce optimal
results comparing to the other algorithms. Finally, we propose a network
architecture to deploy the proposed anomaly-based intrusion detection system
across the Advanced Metering Infrastructure network. In addition, we propose a
network security architecture composed of two types of Intrusion detection
system types, Host and Network-based, deployed across the Advanced Metering
Infrastructure network to inspect the traffic and detect the malicious one at
all the levels.Comment: 7 pages, 6 figures. 2019 NISS19: Proceedings of the 2nd International
Conference on Networking, Information Systems & Securit
Sociotechnical Imaginaries: A Possible Contribution to Science Education
This is a conceptual paper that highlights notions of sociotechnical imaginaries (STIs; Jasanoff, 2015) from fields of Science and Technology Studies (STS) that seem relevant to science education aimed at preparing critical and active citizens (Bencze, 2017). We extend our discussion to fields of future studies in science education to argue that a needed direction is not merely to get students to imagine desired (often personalized) futures (especially given social and environmental harms), but to interrogate how products of science and technology seem to delimit kinds of futures we ought to desire. That is, technoscientific futures are not just out there, but are already present, actively fashioning current practices and values. Drawing from STS literature, we demonstrate how STIs are enacted through two current technoscientific products: self-tracking devices and algorithms. We argue that such technoscience products have an active role in constructing certain kinds of individuals/publics (e.g., quantified citizens, calculated publics). Roles of material technologies in normalizing moral and political visions and future orientations need to be explicitly addressed in re-centering nature of technology as inseparable from nature of science (Roth, 2001). Notions of STIs further offer more nuanced approaches to discuss power at the interface of the public/private within STS Education (Pedretti & Nazir, 2011). Finally, notions of STIs may present us with new ways for (re-)encountering affect in science education (Alsop, 2016), as feelings of hope and anxieties contour (how we come to re-envision) imaginaries grounded in technoscientific worlds
Frequency and Predictors of Opioid Use in Rheumatoid Arthritis and Seronegative Spondyloarthropathy Patients
Background: Pain is one of the most challenging symptoms in patients with rheumatoid arthritis (RA) and spondyloarthropathies (SpAs), and pain relief is one of the top priorities for improving health-related quality of life. When medication therapy does not significantly reduce pain, chronic opioid consumption becomes more prominent in such patients. This study aimed to evaluate the state of opioid use in RA and SpA patients.Methods: This cross-sectional study was performed on 316 patients with RA and spondyloarthropathies (SpAs) from January to March 2014. The convenience sampling method was used to select the participants, and by obtaining verbal consent, everyone was given 15 minutes to complete a checklist independently. Demographic and opioid use data were evaluated in terms of opioid use and its predictors. In this regard, univariate and multivariate logistic regressions were used to evaluate the predictors of opioid consumption in patients. All analyses were conducted using SPSS 21 and the significance level was set at P<0.05.Findings: About 9.5% of all participants, including 8.8% of RA and 22.6% of SpA cases, were opioid abusers. In the first step of the analysis, it was observed that opioid abuse was significantly higher in men, married participants, urban residents, patients with no biological therapy, and patients with a negative family history of addiction. The most prevalent ways of drug abuse were smoking and ingestion. The results of univariate logistic regression analysis revealed SpA and other factors significantly increase the chance of opioid abuse. Furthermore, multivariate logistic regression analysis showed male gender (OR=10.4) and negative family history of addiction (OR=3.19) significantly affected addiction in RA and SpA patients with a 95% confidence interval.Conclusion: Lack of suitable responsiveness to medication therapy to relieve pain, inconsistent pain evaluation, and shame of asking direct questions about addiction in RA and SpA patients may lead to opioid consumption in some cases. Seronegative SpA may make patients more prone to addiction. However, in this study, male gender and no family history of addiction were related to opioid abuse
Impact of psychological problems in chemical warfare survivors with severe ophthalmologic complication, a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Sulfur mustard (SM) has been used as a chemical warfare agent since the early twentieth century. Despite the large number of studies that have investigated SM induced ocular injuries, few of those studies have also focused on the psychological health status of victims. This study has evaluated the most prominent influences on the psychological health status of patients with severe SM induced ocular injuries.</p> <p>Methods</p> <p>This descriptive study was conducted on 149 Iranian war veterans with severe SM induced eye injuries. The psychological health status of all patients was assessed using the Iranian standardized Symptom Check List 90-Revised (SCL90-R) questionnaire. The results of patients' Global Severity Index (GSI) were compared with the optimal cut-off point of 0.4 that has previously been calculated for GSI in Iranian community. The Mann-Whitney U test, T tests and effect sizes (using Cohen's d) were employed as statistical methods. Data were analyzed using SPSS software.</p> <p>Results</p> <p>The mean age of patients was 44.86 (SD = 8.7) and mean duration of disease was 21.58 (SD = 1.20) years. Rate of exposure was once in 99 (66.4%) cases. The mean GSI (1.46) of the study group was higher compared to standardized cut off point (0.4) of the Iranian community. The results of this study showed that the mean of total GSI score was higher in participants with lower educational levels (effect size = 0.507), unemployment (effect size = 0.464) and having more than 3 children (effect size = 0.62). Among the participants, 87 (58.4%) cases had a positive psychological history for hospitalization or receiving outpatient cares previously and 62 (41.6%) cases had a negative psychological history. In addition, the mean of GSI in participants with negative psychological history was lower than those with positive psychological history (Mean Change Difference = -0.621 with SD = 0.120). There was a significant difference between positive and negative psychological history with respect to GSI (P < 0.001).</p> <p>Conclusion</p> <p>The study showed that severe ophthalmologic complications in chemical survivors are accompanied with destructive effects on psychological health status. Appropriate management may improve psychological health status in these patients.</p
MLH1 Methylation-Based Testing in Peripheral Blood Mononuclear Cells is a Promising Biomarker for Colorectal Cancer Diagnosis and Prognosis
Background: Recent evidence has shown that peripheral blood mononuclear cells (PBMCs) can reflect the epigenetic profile of tissues they interact with, such as malignant cells. The hypermethylation of MLH1 promoter is a well-defined epigenetic alteration in the development of colorectal cancer (CRC). This is the first study aimed to assess the diagnostic and prognostic values of the methylation level of MLH1 promoter in PBMCs of patients with CRC.Method: In this case-control study, the methylation level at the promoter region of MLH1 was quantitatively analyzed in 60 CRC patients and 60 non-cancerous study participants via methylation-quantification of endonuclease-resistant DNA (MethyQESD). The receiver operating characteristic (ROC) curves were constructed and the areas under the curve were calculated to determine the diagnostic significance of MLH1 gene methylation.Results: Our data showed a significant increase in methylation of MLH1 in CRC patients compared with healthy participants (P 0.001). Besides, MLH1 methylation levels was significantly increased in CRC patients with higher tumor stages, suggesting a probable correlation between an increased percentage of methylation and tumor progression (P 0.05).Conclusion: Our results propose that MLH1 methylation status in PBMCs can be used as a promising diagnostic and prognostic biomarker and reliable factor for CRC screening
Liriodenine, an aporphine alkaloid from &shy;Enico&shy;santhellum pulchrum, inhibits proliferation of&nbsp;human ovarian cancer cells through induction of apoptosis via the mitochondrial signaling pathway and blocking cell cycle progression
Enicosanthellum pulchrum is a tropical plant from Malaysia and belongs to the Annonaceae family. This plant is rich in isoquinoline alkaloids. In the present study, liriodenine, an isoquinoline alkaloid, was examined as a potential anticancer agent, particularly in ovarian cancer. Liriodenine was isolated by preparative high-performance liquid chromatography. Cell viability was performed to determine the cytotoxicity, whilst the detection of morphological changes was carried out by acridine orange/propidium iodide assay. Initial and late apoptosis was examined by Annexin V-fluorescein isothiocyanate and DNA laddering assays, respectively. The involvement of pathways was detected via caspase-3, caspase-8, and caspase-9 analyses. Confirmation of pathways was further performed in mitochondria using a cytotoxicity 3 assay. Apoptosis was confirmed at the protein level, including Bax, Bcl-2, and survivin, while interruption of the cell cycle was used for final validation of apoptosis. The result showed that liriodenine inhibits proliferation of CAOV-3 cells at 37.3 μM after 24 hours of exposure. Changes in cell morphology were detected by the presence of cell membrane blebbing, chromatin condensation, and formation of apoptotic bodies. Early apoptosis was observed by Annexin V-fluorescein isothiocyanate bound to the cell membrane as early as 24 hours. Liriodenine activated the intrinsic pathway by induction of caspase-3 and caspase-9. Involvement of the intrinsic pathway in the mitochondria could be seen, with a significant increase in mitochondrial permeability and cytochrome c release, whereas the mitochondrial membrane potential was decreased. DNA fragmentation occurred at 72 hours upon exposure to liriodenine. The presence of DNA fragmentation indicates the CAOV-3 cells undergo late apoptosis or final stage of apoptosis. Confirmation of apoptosis at the protein level showed overexpression of Bax and suppression of Bcl-2 and survivin. Liriodenine inhibits progression of the CAOV-3 cell cycle in S phase. These findings indicate that liriodenine could be considered as a promising anticancer agent
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Optimization of Discharge Plasma Reactor for Dry Reforming of Methane using Response Surface Methodology
This research provides a study of the dry reforming of methane (DRM), which converts two main greenhouses gases (CO2 and CH4) to synthesis gas (H2 and CO) by a Dielectric Barrier Discharge (DBD) plasma reactor at atmospheric pressure. The Box-Behnken Design (BBD) method based on the Response Surface Methodology (RSM) was applied to determine the optimum experimental conditions on the plasma stability and the synthesis gas production. The synergistic effects of input power (P), CO2/CH4 ratio (R), and flow rate (FR) on the CO2, CH4 conversions, H2, CO yields, and the syngas ratio of H2 to CO were studied. With the desirability value of 0.97, the optimum values of 10.05 W (P), 1.03 (R), and 1.58 L.min−1 FR were identified with CO2 conversion of 48.56% and CH4 conversion of 86.67%; H2 and CO yields of 45.87% and 39.43% respectively; and syngas ratio of H2 to CO of 0.88. The study shows that both P and FR have a major significant effect on the reactant conversions and syngas ratio, followed by R. Meanwhile, the value of R has a significant impact on the H2, CO yields followed P and FR. In contrast, the synergistic effects between P-R, P-FR, and R-FR had a weak significant on the CO2 and CH4 conversions, H2 and CO yields, and H2 to CO ratio respectively. The quadratic term coefficients of P, R, and FR had a remarkable effect on all responses. Thus, the synergistic effect of the most important parameters improves the process efficiency. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
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