958 research outputs found

    Purification and biochemical characterization of a Ca2+- independent, thermostable and acidophilic α-amylase from Bacillus sp. RM16

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    Bacillus sp. RM16 was isolated from a hot spring in Karachi and screened for the production of α- amylase. The enzyme was obtained after 72 h cultivation of strain in Luria broth containing 1% starch (w/v). Enzyme Amy RM16 was purified to electrophoretic homogeneity by a series of sequential steps including precipitation with ammonium sulfate at 70% saturation, Q-Sepharose, Phenyl Sepharose and reversed phase chromatography. The purified enzyme is made up of a single polypeptide chain of 66 kDa as established by a combination of SDS-PAGE and zymographic analysis. In our experimental conditions, a total yield of 1.35% with specific activity of 6380U/mg was obtained providing 17 fold final purification of the enzyme. Biochemical characterization of the Amy RM16 such as optimum temperature and pH, substrate specificity and enzymatic susceptibilities towards different metal ions and inhibitors were also performed. Results of these studies revealed that, the enzyme is active at wide temperature range with optimum activity at 80°C and retained 85% of the activity for 3 h at 50°C and around 50% of remaining activity for 1 h at 80°C. The enzyme showed optimum activity at pH 5.0. On the other hand, Ca+2 and EDTA (1 to 5 mM) did not significantly affect the enzyme activity. The main substrate for the enzyme was found to be starch but it could also hydrolyze raw starch, dextrin, γ-cyclodextrin and pullulan.Key words: Ca2+-independent, Bacillus sp, thermostable α-amylases, low pH profile, enzyme, raw starch digestion, HPLC

    On Ordered (p; q)-Lateral Ideals in Ordered Ternary Semigroups

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    In this paper, we study some useful results of ordered (p; q)-lateral ideals in ordered ternary semigroups. Also, some properties of (p; q)-lateral simple ordered ternary semigroup have been examined. Further, we characterize the relationship between minimal (resp., maximal) ordered (p; q)- lateral ideals and (p; q)-lateral simple ordered ternary semigroups

    Rough Probability In Topological Spaces

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    In this paper we study the rough probability in the topological spaces which we can consider them as results from the general relations on the approximation spaces. Keywords: Stochastic approximation space, rough expectation, rough variance, rough probability generating function, rough characteristic function.

    Decomposition of Continuity and Separation Axioms Via Lower and Upper Approximation

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    In this paper we study the rough set theory by defined the concepts of rough regularity and rough normality in the topological spaces which we can consider them as results from the general relations on the approximation spaces. Keywords: Topologized approximation space, rough regularity, rough normality, rough continuity, rough homeomorphism

    Skin Conductance as Proxy for the Identification of Hydration Level in Human Body

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    The skin dehydration level can be used to infer serious health conditions in patients since diseases like cardiovascular abnormality, diabetes and cancer symptoms do exhibit correlation with skin disorders. Therefore a systematic analysis of human skin hydration levels is critical for multiple health care applications. Motivated by this, in this study we proposed a unique approach of measuring body hydration levels against different body postures using skin conductance electrical activity. In this paper, we report the collection, processing and analysis techniques used in the analysis of skin conductance data. Subsequently in order to predict body hydration levels we employed state-of-the-art machine learning models using the skin conductance data and achieved 81.82% and 73.91% recognition accuracy for the data of standing and sitting postures,respectively using KNN model

    Inkjet-printed UHF RFID tag based system for salinity and sugar detection

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    This article presents an RFID system to detect the salinity and sugar contents of water. The proposed system is based on low‐cost ink‐jet printed passive ultrahigh frequency (UHF) RFID tag. The tag is designed using slot match technique, which poses a good imaginary impedance match with RFID chip both in free space and after mounting on the water bottle. Moreover, the tag antenna is exploited as a sensor to detect salt and sugar contents of water by measuring the backscatter power from the tag in term of received signal strength indicator (RSSI). A Tagformance Pro setup form Voyantic is used for measuring RSSI. Furthermore, an approximate relationship is derived between backscatter power and no. of grams of salt and sugar dissolved in water. This study paves a way to check the contents of drinks using portable devices, which is pivotal for healthcare applications in smart cities and the future Internet of things (IoT)

    Extremely low profile flexible antenna for medical body area networks

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    Medical Body Area Networks (MBAN) are widely used in healthcare systems employing in- and on-body applications. An extremely low profile patch antenna for the MBANs is presented in this paper. The antenna consists of two flexible printed circuit boards (FPCB) separated by an air gap and uses a rectangular radiating patch with four slots. Two variants of the antenna having single and dual band operation are discussed. The single band antenna operates at 2.4 GHz while the dual band antenna works at frequencies of 2.4 GHz and 4.3 GHz. Both versions of the proposed antenna offer good bandwidth, high gain and radiation coverage for the MBAN applications

    Quality of life of road traffic injury survivors aged 15-44 years suffered from moderate and severe head injuries in Karachi, Pakistan

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    Background: Most of Road traffic injuries are predicted to be the third leading contributor to the global burden of disease by 2020 and patients end up into head injuries which leave devastating impacts on individual and society. Quality of Life After Brain Injury (QOLIBRI) is a specific tool that measures quality of life in head injury patients.Methods: This was a cross sectional study among 300 patients aged 15-45 years, attended emergency department of the Aga khan University Hospital. Structured questionnaire included demography, injury details, QOLIBRI, GOSE and WHO Disability Assessment Scale (WHODAS 12 items). Severity of injury was determined by Glasgow coma score of subjects reported in emergency department on admission. This was one time telephonic survey in which bidirectional data was collected from subjects about injury and outcome (QOLIBRI). To identify the determinants of QOL among RTI survivors with head injury multiple linear regressions was applied.Results: The mean QOL score for study sample was 69.86 ± (15.89. Most of the patients 210 (70%) were motorbike rider followed by four-wheelers 69 (23%). Mean age of RTI participants was 28.10 ± (7.68) years. The quality of life decreases with increase in severity of head injury by -697.32 (95% CI; -1006.44, -388.20).Conclusions: This study suggests severity of head injury, recovery time, surgery resulting from RTA, employment, family system and disability to have long term impact on QOL of RTI survivors

    SoK: Security of Programmable Logic Controllers

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    Billions of people rely on essential utility and manufacturing infrastructures such as water treatment plants, energy management, and food production. Our dependence on reliable infrastructures makes them valuable targets for cyberattacks. One of the prime targets for adversaries attacking physical infrastructures are Programmable Logic Controllers (PLCs) because they connect the cyber and physical worlds. In this study, we conduct the first comprehensive systematization of knowledge that explores the security of PLCs: We present an in-depth analysis of PLC attacks and defenses and discover trends in the security of PLCs from the last 17 years of research. We introduce a novel threat taxonomy for PLCs and Industrial Control Systems (ICS). Finally, we identify and point out research gaps that, if left ignored, could lead to new catastrophic attacks against critical infrastructures.Comment: 25 pages, 13 figures, Extended version February 2024, A shortened version is to be published in the 33rd USENIX Security Symposium, for more information, see https://efrenlopez.org
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