4,980 research outputs found
Enzymes in Biofuels Production
No full textWith the inevitable depletion of the nonrenewable resources of fossil fuels and due to their favorable environmental features, biofuels promise to be the preferred fuels of tomorrow. They can displace petroleum fuels and, in many countries, reduce the dependence on imported fuel. Biofuels, derived from biomass conversion, such as biodiesel, bioethanol, biohydrogen, and biogas, are sustainable and renewable sources of energy, which are also considered CO2 neutral. In addition, burning biofuels results in reduced levels of particulates, carbon oxides and sulfur oxides, emissions compared to fissile fuels
A proposed case for the Cloud Software Engineering in Security
No full textThis paper presents Cloud Software Engineering in Security (CSES) proposal that combines the benefits from each of good software engineering process and security. While other literature does not provide a proposal for Cloud security as yet, we use Business Process Modeling Notation (BPMN) to illustrate the concept of CSES from its design, implementation and test phases. BPMN can be used to raise alarm for protecting Cloud security in a real case scenario in real-time. Results from BPMN simulations show that a long execution time of 60 hours is required to protect real-time security of 2 petabytes (PB). When data is not in use, BPMN simulations show that the execution time for all data security rapidly falls off. We demonstrate a proposal to deal with Cloud security and aim to improve its current performance for Big Data
Recommendations and best practices for Cloud enterprise security
No full text© 2014 IEEE. Enterprise security is essential to achieve global information security in business and organizations. Enterprise Cloud computing is a new paradigm for that enterprise where businesses need to be secured. Enterprise Cloud computing has established its businesses and software as a service paradigm is increasing its demand for more services. However, this new trend needs to be more systematic with respect to Enterprise Cloud security. Enterprise Cloud security is the key factor in sustaining Enterprise Cloud technology by building-in trust. For example, current challenges that are witnessed today with cyber security and application security flaws are important lessons to be learned. It also has provided best practices that can be adapted. Similarly, as the demand for Enterprise Cloud services increases and so increased importance sought for security and privacy. This paper presents recommendations for enterprise security to analyze and model Enterprise Cloud organizational security of the Enterprise Cloud and its data. In particular, Enterprise Cloud data and Enterprise Cloud storage technologies have become more commonly used in organization that adopt Cloud Computing. Therefore, building trust for Enterprise Cloud users should be the one of the main focuses of Enterprise Cloud computing research
Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs
No full textIntroduction: The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression. Methods: Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1? (IL-1?), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data. Results: CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1?. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1? (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1?, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1?-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1?-treated constructs. Conclusions: Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1?. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old. <br/
Network layer security: Design for a cross layer architecture
No full textTraditional modular layering schemes have served a major part in the development of a variety of protocols. However, as the physical layer impairments become more unpredictable, a cross layer design (CLD) which is dynamic in nature provides better performance. CLD introduces new challenges in protocol design as well as in the area of security. Using numerical analysis, we show that a link layer design employing header compression and cross layer signalling to protect protocol headers can limit packet discarding. This paper also reviews the IPsec protocol and describes how IPsec can be modified for cross layer architecture. © 2007 IEEE
The association of peak systolic velocity in the carotid artery with coronary heart disease: A study based on portable ultrasound.
No full textCardiovascular disease (CVD) is the highest cause of death globally with more people dying annually from it than from any other cause. CVD is associated with modifiable risk factors (dyslipidaemia, hypertension and diabetes) and treating each of these factors lowers the risk of CVD. It is impossible to estimate the benefit of risk factor modification in the individual patient and extrapolating data from multiple trials is difficult. It would be useful to have a marker of risk that accurately estimates real time risk by measuring blood flow factors associated with the pathogenesis of atheroma. The aim of this preliminary study was to validate a low-cost measurement technique for obtaining blood flow velocity profiles and assess whether any of the measured and calculated factors, based on computational fluid dynamics (CFD) simulation, known to be associated with atheroma was associated with coronary heart disease (CHD), thus establishing its feasibility and acceptability as a clinical tool and suggesting areas for future research. Our study identified (i) that mean peak systolic (PS) velocity being associated with CHD; individuals without CHD: mean (SD) = 62.8 (16.1) cm/s, with CHD: mean (SD) = 53.6 (17.3) cm/s, = 0.042; and (ii) that low-cost, portable ultrasound, which is routinely available in general practice, is a suitable assessment tool
Financial software as a service – a paradigm for risk modelling and analytics
No full textSoftware as a service as one of the cloud delivery models that supports fine-grained components. Financial applications demand better performance and accuracy in a cloud than the traditional computing platforms. Therefore, designing financial software as a service (FSaaS) requires an engineering and systematic approach. This paper has proposed an integrated service-oriented architecture and a SaaS component model for financial domain that provides the required scalability, flexibility and customisation. We have also demonstrated the design and customisation of service component interfaces to a financial simulation so that it provides automatic prediction models for investors to know accurate results for buy and sale prices. Therefore, large-scaled simulations can be achieved within a matter of 13.5 second for outlier removal and within 9 seconds for high-performance risk computation on the Cloud. We show the holistic and complete approach of illustrating the system design of FSaaS, showing the two major algorithms and the results of experiments of running these two algorithms. We provide plans to integrate new and existing services with FSaaS
Mapping tropical forest aboveground biomass using airborne SAR tomography
No full textMapping tropical forest aboveground biomass (AGB) is important for quantifying emissions from land use change and evaluating climate mitigation strategies but remains a challenging problem for remote sensing observations. Here, we evaluate the capability of mapping AGB across a dense tropical forest using tomographic Synthetic Aperture Radar (TomoSAR) measurements at P-band frequency that will be available from the European Space Agency’s BIOMASS mission in 2024. To retrieve AGB, we compare three different TomoSAR reconstruction algorithms, back-projection (BP), Capon, and MUltiple SIgnal Classification (MUSIC), and validate AGB estimation from models using TomoSAR variables: backscattered power at 30 m height, forest height (FH), backscatter power metric (Q), and their combination. TropiSAR airborne campaign data in French Guiana, inventory plots, and airborne LiDAR measurements are used as reference data to develop models and calculate the AGB estimation uncertainty. We used univariate and multivariate regression models to estimate AGB at 4-ha grid cells, the nominal resolution of the BIOMASS mission. Our results show that the BP-based variables produced better AGB estimates compared to their counterparts, suggesting a more straightforward TomoSAR processing for the mission. The tomographic FH and AGB estimation have an average relative uncertainty of less than 10% with negligible systematic error across the entire biomass range (~ 200–500 Mg ha^−1). We show that the backscattered power at 30 m height at HV polarization is the best single measurement to estimate AGB with significantly better accuracy than the LiDAR height metrics, and combining it with FH improved the accuracy of AGB estimation to less than 7% of the mean. Our study implies that using multiple information from P-band TomoSAR data from the BIOMASS mission provides a new capability to map tropical forest biomass and its changes accurately
A new species of<i>Gymnema</i>(Asclepiadaceae) from the Kollihills in Peninsular India
No full textFIG. 1. — Gymnema kollimalayanum A. Ramachandran & M.B.Viswan.: A, habit (flowering twig); B-E, portions of stem enlarged showing development of warty outgrowths in different stages; F-H, parts of inflorescence showing different types of floral arrangements; I, dorsal view of bract; J, ventral view of bract; K, calyx; L, flower; M, dorsal view of corolla; N, corolla split open without coralline corona; O, part of coralline corona; P, ovary; Q, longitudinal section of ovary; R, transverse section of ovary; S, follicles; T, seed with coma. A-R, Ramachandran 912; S, T, Ramachandran 928. Scale bars: A, 15 mm; B-H, S, 10 mm; I-R, 1 mm; T, 5 mm.Published as part of Ramachandran, Andimuthu & Viswanathan, Madepalli Byrappa Gowdu, 2009, A new species of Gymnema (Asclepiadaceae) from the Kollihills in Peninsular India, pp. 407-411 in Adansonia (3) 31 (2) on page 409, DOI: 10.5252/a2009n2a10, http://zenodo.org/record/460129
A cross-layer architecture for satellite network security: CL-IPsec
No full textCross-layer architectures (CLAs) are proposed to improve performance in networks where physical layer impairments are unpredictable and provision of security services may be challenging, as in satellite networks. This paper proposes an extension to the IPsec protocol, named Cross-Layer IPsec (CL-IPsec), able to provide authentication and integrity services through a cross-layer architecture when the adopted protocol is UDP-Lite. This is suitable for multicast applications that are cost-effectively provided by satellite systems. A satellite emulation platform has been used to validate the CL-IPsec implementation and to evaluate the performance improvement derived from the proposed CLA. © 2008 IEEE
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