656 research outputs found
Dependability of body area wireless sensor networks in assistive care loop framework
University of Technology, Sydney. Faculty of Engineering and Information Technology.The exponential growth in wireless communication and micro-electro-mechanical systems gave birth to low power, low cost, multifunctional and miniature wireless sensors. Wireless sensor networks (WSNs) are finding applications in many areas, particularly in healthcare, a WSN can be used highly effectively in the form of a Body Area Wireless Sensor Network (BAWSN), to enhance the quality of the contemporary healthcare services. This tendency triggered the in-house healthcare monitoring application (HMA) with the BAWSN as their monitoring component. The quality of life of the patients can be improved with the deployment of a BAWSN because the patients and the care staff would be able to monitor the health condition, to access the electronic medical records and communicate with each other by using a Personal Digital Assistant (PDA) or smart phone in their hands, regardless of where they are located or what their duties might be. This remote monitoring and consultations might reduce the traditional stressful and costly exercise of frequent hospitalisation.
The rising costs of healthcare in many developed countries have influenced the introduction of the HMA into existing health care practices. However, the successful deployment of the civilian and commercial HMA is still in its infancy stages for some of the following reasons: (a) a generic framework for building the HMA is needed for the application developer to materialise the concepts, (b) an effective set of measurable properties is required for the users to evaluate the performance of the BAWSN used in the HMA, (c) the method used for measuring the performance of a monitoring application is not suitable for the BAWSN used in the HMA, (d) any unauthorized modifications to health data may induce a false diagnosis and put a life in danger; this must be considered together with the privacy of the users in the application, without any compromise and, (e) the body sensors operate in close proximity to the human body, therefore it is imperative to ensure the operational safety of BAWSN.
Our research shows that the dependable properties of an application encompass most of the essential demands for the actual realization of the HMA. It also shows that the dependable system can deliver services that can be justifiably trusted. The focus of this work is on the BAWSN, because the service ability of the HMA depends heavily on its monitoring component, the BAWSN. Therefore, in this thesis, we define and investigate six fundamental effective properties, maintainability, reliability, availability, confidentiality, integrity and safety, based on BAWSN requirements under the dependability framework. We built an Assistive Care Loop Framework (ACLF), a maintainable BAWSN-based HMA, for monitoring pregnant women based on an event-driven architecture that follows layered functionalities. A novel critical time parameter is introduced to satisfy the needs of the medical diagnoses that require the BA WSN to rely on the collection of data within a critical time from all of the source sensor nodes. The process and issues involved in the medical diagnoses are also explored; these influenced the characterization of the BAWSN as a time critical application. Based on the critical time, we derived non-device-centric time-specific parameters with which we formulated a novel empirical measure model for the transmission reliability and availability in the BAWSN. To compare the empirical measure model, analogous theoretical models are also derived for the BAWSN's reliability and availability. To safeguard the patient's health data and also to ensure their privacy in the BAWSN, we proposed a secure adaptive triple-key scheme (aTKS) in such a way that it incurs minimal overheads while meeting the stringent time requirements of the BAWSN.
The deployed ACLF exemplifies the concept of the HMA being used not only for alerting the care staff in case of emergency, but also for analysing a patient's progress over a period of time to forecast any emergency situation. The performance of the proposed measure models and the implemented aTKS from our real-time test-bed would enable the application developer to measure the performance of the BAWSN-based application because, to the best of our knowledge, no measure exists in the literature as such for a BAWSN-based application. The formulated minimal set of dependable properties might serve as a benchmark for evaluating the performance of a BAWSN, and in turn, the HMA
Biochemical Characterisation of 18 Accessions of Sweet Potato (Ipomoea batatas L. Lam.) using Total Leaf and Tuberous Root Protein by SDS-PAGE
DNA-based markers,undeniably, provide potent tools for studying genetic relationships in plants; however, potential of protein-based markers using SDS-PAGE is quite promising, particularly in developing countries. Plant storage proteins serve as molecular reserves imperative for plant growth and maintenance and thus have proven to be essential for the survival of plant species. Storage proteins are also indispensable in plant defense mechanisms as insecticidal and anti-microbial proteins. They have also been widely employed as biochemical markers for genetic diversity studies. Eighteen sweet potato (Ipomoea batatas L. Lam) accessions with local or exotic origin were evaluated for genetic diversity using leaf and tuberous root protein via sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Marked variations observed in the electrophoregrams of total leaf and tuberous root proteins gave an indication of intense variability among the accessions. Molecular size of proteins ranged from 20.23 to 28.89 kDa and 22.44 to 97.19 kDa, in the total leaf and tuberous root proteins, respectively. Two pairs of accessions SA/BNARI and UE 007 as well as HMA 1 and US 029 were identified as duplicates based on their banding patterns. Keywords: Biochemical, characterisation, SDS-PAGE, sweet potato, leaf& tuberous root protei
Locally responsive intervention to improve municipal solid waste collection coverage in Accra, Ghana
The paper reports on a process that engaged stakeholders to assess the strengths and weaknesses of the
city of Accra’s approach to raising solid waste collection coverage. Stakeholders, working with
researchers, have made the evaluation using a combination of benchmark indicators, analysis of
franchise agreements, process flow diagramming of collection trends, and statistical analysis of user
answers to a survey. Informal services are growing while formal services are shrinking. A logistic
regression model suggests that regular collection and affordable user charges significantly increases the
levels of user satisfaction. The use of a participatory approach has led to an unusual alliance: formal
service providers have agreed to work with informal providers as subcontractors and support them to
formalize and increase collection coverage. The positive experience of participation leads the authors to
advocate institutionalizing the use of a participatory approach through stakeholder platforms to evaluate
interventions and develop plans for service improvement
ANTIOXIDANT AND ANTI-PROLIFERATIVE EFFECTS OF AN ETHYL ACETATE FRACTION OF THE HYDRO-ETHANOLIC EXTRACT OF SYNEDRELLA NODIFLORA (L) GAERTN
Objective: Synedrella nodiflora is traditionally used in the treatment of several ailments. Pharmacologically, this plant has anticonvulsant, sedative, anti-nociceptive and anti-proliferative effects. This study further investigated S. nodiflora for its antioxidant and in vitro inhibition of cancerous cell lines.
Methods: Phytochemical assays, and the DPPH radical scavenging method were employed in preliminary screening for antioxidant activities of the crude hydro-ethanolic extract (SNE) and resulting fractions. The potent ethyl acetate fraction (EAF), was further investigated for total phenol and flavonoid contents, reducing power, lipid peroxidation potential, and cytotoxic effects on human breast cancer (MCF-7), leukemic (Jurkat), and normal liver (Chang’s liver) cell lines.
Results: The extract contained phenols, flavonoids, tannins, glycosides, sterols, terpenoids, and alkaloids. It scavenged for DPPH with an IC50 of 114 µg/ml, whereas that of EAF was 8.9 µg/ml. EAF prevented peroxidation of egg lecithin at an IC50 of 24.01±0.08 µg/ml. These IC50s are four and three times lower than the reference standards. EAF produced anti-proliferative effects against MCF-7, and Jurkat cell lines with IC50s of 205.2 and 170.9 µg/ml, respectively. EAF had a high IC50 of 252.2 µg/ml against Chang’s liver cells. At 0.1 mg/ml EAF had similar total flavonoid content to SNE, but a significantly higher total phenol content.
Conclusion: The ethyl acetate fraction of S. nodiflora, exhibited the most potent antioxidant activity. It inhibited the proliferation of breast and leukemic cancer cell lines, whiles having weak cytotoxic effect on normal liver cells. These can be explored for further drug development
Personal identity (de)formation among lifestyle travellers: A double-edged sword?
This article explores the personal identity work of lifestyle travellers – individuals for whom extended leisure travel is a preferred lifestyle that they return to repeatedly. Qualitative findings from in-depth semi-structured interviews with lifestyle travellers in northern India and southern Thailand are interpreted in light of theories on identity formation in late modernity that position identity as problematic. It is suggested that extended leisure travel can provide exposure to varied cultural praxes that may contribute to a sense of social saturation. Whilst a minority of the respondents embraced a saturation of personal identity in the subjective formation of a cosmopolitan cultural identity, several of the respondents were paradoxically left with more identity questions than answers as the result of their travels
Epidemiological Interactions between Urogenital and Intestinal Human Schistosomiasis in the Context of Praziquantel Treatment across Three West African Countries
© 2015 Knowles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
Inhibition of Mg2+ binding and DNA religation by bacterial topoisomerase I via introduction of an additional positive charge into the active site region
Among bacterial topoisomerase I enzymes, a conserved methionine residue is found at the active site next to the nucleophilic tyrosine. Substitution of this methionine residue with arginine in recombinant Yersinia pestis topoisomerase I (YTOP) was the only substitution at this position found to induce the SOS response in Escherichia coli. Overexpression of the M326R mutant YTOP resulted in ∼4 log loss of viability. Biochemical analysis of purified Y. pestis and E. coli mutant topoisomerase I showed that the Met to Arg substitution affected the DNA religation step of the catalytic cycle. The introduction of an additional positive charge into the active site region of the mutant E. coli topoisomerase I activity shifted the pH for optimal activity and decreased the Mg2+ binding affinity. This study demonstrated that a substitution outside the TOPRIM motif, which binds Mg2+directly, can nonetheless inhibit Mg2+ binding and DNA religation by the enzyme, increasing the accumulation of covalent cleavage complex, with bactericidal consequence. Small molecules that can inhibit Mg2+ dependent religation by bacterial topoisomerase I specifically could be developed into useful new antibacterial compounds. This approach would be similar to the inhibition of divalent ion dependent strand transfer by HIV integrase in antiviral therapy
The G140S mutation in HIV integrases from raltegravir-resistant patients rescues catalytic defect due to the resistance Q148H mutation
Raltegravir (MK-0518) is the first integrase (IN) inhibitor to be approved by the US FDA and is currently used in clinical treatment of viruses resistant to other antiretroviral compounds. Virological failure of Raltegravir treatment is associated with mutations in the IN gene following two main distinct genetic pathways involving either the N155 or Q148 residue. Importantly, in most cases, an additional mutation at the position G140 is associated with the Q148 pathway. Here, we investigated the viral DNA kinetics for mutants identified in Raltegravir-resistant patients. We found that (i) integration is impaired for Q148H when compared with the wild-type, G140S and G140S/Q148H mutants; and (ii) the N155H and G140S mutations confer lower levels of resistance than the Q148H mutation. We also characterized the corresponding recombinant INs properties. Enzymatic performances closely parallel ex vivo studies. The Q148H mutation ‘freezes’ IN into a catalytically inactive state. By contrast, the conformational transition converting the inactive form into an active form is rescued by the G140S/Q148H double mutation. In conclusion, the Q148H mutation is responsible for resistance to Raltegravir whereas the G140S mutation increases viral fitness in the G140S/Q148H context. Altogether, these results account for the predominance of G140S/Q148H mutants in clinical trials using Raltegravir
Embedded Vision Systems: A Review of the Literature
Over the past two decades, the use of low power Field Programmable Gate Arrays (FPGA) for the acceleration of various vision systems mainly on embedded devices have become widespread. The reconfigurable and parallel nature of the FPGA opens up new opportunities to speed-up computationally intensive vision and neural algorithms on embedded and portable devices. This paper presents a comprehensive review of embedded vision algorithms and applications over the past decade. The review will discuss vision based systems and approaches, and how they have been implemented on embedded devices. Topics covered include image acquisition, preprocessing, object detection and tracking, recognition as well as high-level classification. This is followed by an outline of the advantages and disadvantages of the various embedded implementations. Finally, an overview of the challenges in the field and future research trends are presented. This review is expected to serve as a tutorial and reference source for embedded computer vision systems
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