353 research outputs found

    On the Role of Primary and Secondary Assets in Adaptive Security: An Application in Smart Grids

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    peer-reviewedAdaptive security aims to protect valuable assets managed by a system, by applying a varying set of security controls. Engineering adaptive security is not an easy task. A set of effective security countermeasures should be identified. These countermeasures should not only be applied to (primary) assets that customers desire to protect, but also to other (secondary) assets that can be exploited by attackers to harm the primary assets. Another challenge arises when assets vary dynamically at runtime. To accommodate these variabilities, it is necessary to monitor changes in assets, and apply the most appropriate countermeasures at runtime. The paper provides three main contributions for engineering adaptive security. First, it proposes a modeling notation to represent primary and secondary assets, along with their variability. Second, it describes how to use the extended models in engineering security requirements and designing required monitoring functions. Third, the paper illustrates our approach through a set of adaptive security scenarios in the customer domain of a smart grid. We suggest that modeling secondary assets aids the deployment of countermeasures, and, in combination with a representation of assets variability, facilitates the design of monitoring function

    The Nature of Aggregate Demand and Supply Shocks in ASEAN Countries

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    This paper revisits the issue of identification of macroeconomic shocks in ASEAN countries using an alternative identification scheme where the aggregate demand and supply shocks are allowed to be correlated. Applying the technique of Cover et al (2006) within a bivariate Structural VAR model, this paper showed that aggregate demand and supply shocks are interrelated (positively) in ASEAN countries. Unlike previous studies, it is found that changes in the output level are mainly driven by aggregate demand shocks, whereas supply shocks are playing the dominant role in affecting inflation in ASEAN countries. The correlations of the shocks across the countries are found to be quite small, suggesting that ASEAN is still not ready to form a common currency union like Europe

    Hyperoxemia and hypoxemia impair cellular oxygenation:a study in healthy volunteers

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    Introduction: Administration of oxygen therapy is common, yet there is a lack of knowledge on its ability to prevent cellular hypoxia as well as on its potential toxicity. Consequently, the optimal oxygenation targets in clinical practice remain unresolved. The novel PpIX technique measures the mitochondrial oxygen tension in the skin (mitoPO2) which allows for non-invasive investigation on the effect of hypoxemia and hyperoxemia on cellular oxygen availability. Results: During hypoxemia, SpO2 was 80 (77–83)% and PaO2 45(38–50) mmHg for 15 min. MitoPO2 decreased from 42(35–51) at baseline to 6(4.3–9)mmHg (p &lt; 0.001), despite 16(12–16)% increase in cardiac output which maintained global oxygen delivery (DO2). During hyperoxic breathing, an FiO2 of 40% decreased mitoPO2 to 20 (9–27) mmHg. Cardiac output was unaltered during hyperoxia, but perfused De Backer density was reduced by one-third (p &lt; 0.01). A PaO2 &lt; 100 mmHg and &gt; 200 mmHg were both associated with a reduction in mitoPO2. Conclusions: Hypoxemia decreases mitoPO2 profoundly, despite complete compensation of global oxygen delivery. In addition, hyperoxemia also decreases mitoPO2, accompanied by a reduction in microcirculatory perfusion. These results suggest that mitoPO2 can be used to titrate oxygen support.</p

    Annual Biomass Production, Chemical Composition and In- sacco Degradability of Different Cultivars of Moringa oleifera

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    Types of plant cultivars and seasons often affect production and productivity of fodder biomass and nutritional quality to animals. Selection of suitable cultivars and better understanding of year round biomass production are indispensable for improving quality feed supply to animals. Black Seed Moringa (BSM-L) and White Seed Moringa (WSM), the two local cultivars and Black Seed Moringa (BSM-T) cultivar of Thailand origin of Moringa oleifera were cultivated in the fodder research field of the Bangladesh Livestock Research Institute (BLRI) during the period of 19 August 2014 to 23 December 2015. An agronomical trial was conducted to determine the biomass yield of the three cultivars in different seasons of a year under common agronomical practices. The effect of the cultivars on the daily relative growth rate (RGR), chemical composition and in-sacco dry matter (DM) degradability were also evaluated. The cultivar response to biomass production performances, chemical composition and nutritional values were analyzed in an ANOVA of a Randomized Block Design (RBD), while the differences in the rate and extent of the DM degradability in-sacco determined using three rumen cannulated bulls were analyzed in an ANOVA of 3x3 Latin Square Design. The annual biomass yield of BSM-L tops (114.5 t/ha fresh; 22.7 t/ha DM) was significantly higher than that of WSM (29.0 t/ha fresh; 5.80 t/ha DM) or BSM-T (83.5 t/ha fresh; 16.0 t/ha DM). No significant difference in chemical composition (224.9, 222.4 & 223.8 g.kg-1 DM of crude protein (CP), respectively, and 450.9, 455.3 & 435.4 g.kg-1 DM of neutral detergent fiber, respectively) or nutritional value (47.4, 46.7 & 45.3% of potential, and 62.8, 64.2 and 63.6% of effective degradability of dry matter) was found for the cultivars. BSM-L had a significantly higher survivability (97.2%), prune number per plant (3.50) and RGR (15.6 mg DM/day) than WSM (25.0%, 2.30 & 4.20 mg DM/day) or BSM-T (55.6%, 3.10 & 10.8 mg DM/day) respectively. The hot and dry, and hot and humid climate having a Heat Index (HI) range of 25o to 35o F and monthly total rainfall of 130 mm to 332 mm were suitable for cultivation of all the Moringa cultivars. It was concluded that considering biomass production and its quality in terms of chemical composition and nutritional values, Black Seed Moringa (Moringa oleifera) may be cultivated as a plant fodder crop for the production of feed for ruminant animals

    Persistence of chloramphenicol in the fish flesh patin (Pangasius hypothalamus) and tilapia (Oreochromis niloticus)

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    Introduction: Increasing antibiotic resistance in bacteria is a serious global problem. This study was aimed to extract the antibiotic Chloramphenicol (CAP) from different parts of the fish flesh. Methods: Fish fleshes were excised from two commercially important fishes: Oreochromatis niloticus.(Red Tilapia) and Pangasius hypothalamus (Patin). The fleshes were chosen form head and tail region where generally antibiotics are spiked to avoid bacterial contamination while kept in cold storages of supermarkets. Each fish fleshes were weighed and spiked with 20,40,80 and 160ppm of CAP and stored at 4°C. The CAP residue from the flesh was extracted immediately after the first spiking was considered as Day-1. The whole extraction processes were done for 1,7,14 and 28 days. HPLC (High Performance Liquid Chromatography) was used to determine the presence of CAP residue in the tested fish flesh. Results: The results showed variations on the percentage of antibiotic residue recoveries at different concentration. In this study, CAP did not degrade and showed variations on the presence of antibiotic residue in the fish flesh. The recoveries of the entire CAP spiking samples ranged from 4.0% -100%. It also revealed the presence of antibiotic residue in Malaysian freshwater cultured fishes. Thus, the relevant authorities should take immediate action regarding this issue in order to prevent the harmful effects especially to human. Conclusions: Nevertheless, the study portrays that antibiotic residues can be sustained long time in the food products under storage conditions, which might have harmful effects on human when they consumed these frozen fishes

    Impact of extracardiac vascular disease on outcomes of 1.4 million patients undergoing percutaneous coronary intervention.

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    OBJECTIVES: Extracardiac vascular disease (ECVD) is increasingly recognized as a cardiovascular risk factor, but its association with outcomes after percutaneous coronary intervention (PCI) has not been well characterized. METHODS: Using the National Inpatient Sample database, all patients undergoing PCI between October 2015 and December 2018 were stratified by the presence and organ-specific extent of extracardiac vascular comorbidity (cerebrovascular disease (CeVD), renovascular, aortic and peripheral arterial disease (PAD)). Primary outcome was all-cause mortality and secondary outcomes were (a) major adverse cardiovascular and cerebrovascular events (MACCE), (b) acute ischemic stroke and (c) major bleeding. Multivariable logistic regression was used to determine the adjusted odds ratios (aOR) and 95% confidence interval (95% CI). RESULTS: Of a total of 1,403,505 patients undergoing PCI during the study period, 199,470 (14.2%) had ECVD. Patients with ECVD were older (median of 72 years vs. 70 years, p < 0.001) and had higher comorbidity burden that their counterparts. All cause-mortality was 22% higher in patients with any ECVD compared to those without ECVD. PAD patients had the highest odds of all-cause mortality (aOR 1.48, 95% CI 1.40-1.56), followed by those with CeVD (aOR 1.15, 95% CI 1.10-1.19). Patients with extracardiac disease had increased odds of MACCE, ischemic stroke and bleeding, irrespective of the nature or extent (p < 0.05), compared to patients without ECVD. CONCLUSION: ECVD is associated with worse outcomes in patients undergoing PCI including significantly higher rates of death and stroke. These data should inform our shared decision-making process with our patients

    Standerd cervical mediastinoscopy in the diagnosis of mediastinal mass in Ghazi Al-Hariri Hospital

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    Background: Mediastinoscopy is an integral part in the diagnosis of mediastinal mass. The most common indications for mediastinoscopy is for tissue sampling and determining the extent of lung cancer. Objectives: To validate our experience with standard cervical mediastinoscopy and to evaluate the usefulness of cervical mediastinoscopy in the assessing the mediastinal diseases when imaging modalities are none diagnostic. Material and Methods: A retrospective study of 16 patients between January 2012 and July 2014. Mediastinoscopy was indicated for diagnostic staging of nodal disease related to lung cancer in 8 patients (group I) and for isolated mediastinal lymphadenopathy in 8 patients (group II) Results: There were 11 males and 5 females, with a mean age of 47 years. The mean operative time was 30 minutes and the mean hospital stay was 8 hours. In lung cancer (group I) there was positive results in 3 patients and negative results in 5 patients. In patients with isolated mediastinal lymphadenopathy (group II), TB was the commonest diagnosis. There was no surgical related morbidity or mortality in our study. The sensitivity and specificity of standard cervical mediastinoscopy in this study was 100% Conclusion: Standard cervical mediastinoscopy is safe in the hands of well trained persons and needs a good knowledge of the anatomy of the region, cost effective, highly specific and still the first investigation of choice in the diagnosis of mediastinal nodal involvement

    Composition, temperature and frequency dependent magnetic, dielectric and electrical properties of magnesium-zinc ferrites

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    Polycrystalline spinel MgxZn0.3Cu0.7-2xFe2+xO4, where x = 0.10, 0.20, 0.25, 0.30 and 0.35 ferrites (hereafter abbreviated as Mg-Zn) have been prepared by conventional double sintering technique. The samples were sintered at 1250°C in air for 6 hours. Measurements have been done at temperature and frequency ranges of 0 - 350°C and 0 - 500 kHz, respectively. In this work, some extrinsic magnetic properties such as Curie temperature, initial permeability, loss factor, quality factor, dielectric constant and resistivity of the samples have been studied. The Curie temperature and loss tangent of the samples decreased with increase in Cu-content whereas permeability, Qfactor, resistivity and dielectric constant have been noticed to be increased with the increase in Cucontent. The decrease in Curie temperature related to fact of weakening the strength of exchange AB interaction. Maxwell-Wagner type of interfacial polarization might have found correlated with the normal dielectric behavior of the samples, however no relaxation peaks were observed in the dielectric dispersion curves of the Mg-Zn samples in virgin state or doped state
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