Search results for: concept states
495 Monolithic Integrated GaN Resonant Tunneling Diode Pair with Picosecond Switching Time for High-speed Multiple-valued Logic System
Authors: Fang Liu, JiaJia Yao, GuanLin Wu, ZuMaoLi, XueYan Yang, HePeng Zhang, ZhiPeng Sun, JunShuai Xue
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The explosive increasing needs of data processing and information storage strongly drive the advancement of the binary logic system to multiple-valued logic system. Inherent negative differential resistance characteristic, ultra-high-speed switching time, and robust anti-irradiation capability make III-nitride resonant tunneling diode one of the most promising candidates for multi-valued logic devices. Here we report the monolithic integration of GaN resonant tunneling diodes in series to realize multiple negative differential resistance regions, obtaining at least three stable operating states. A multiply-by-three circuit is achieved by this combination, increasing the frequency of the input triangular wave from f0 to 3f0. The resonant tunneling diodes are grown by plasma-assistedmolecular beam epitaxy on free-standing c-plane GaN substrates, comprising double barriers and a single quantum well both at the atomic level. Device with a peak current density of 183kA/cm² in conjunction with a peak-to-valley current ratio (PVCR) of 2.07 is observed, which is the best result reported in nitride-based resonant tunneling diodes. Microwave oscillation event at room temperature was discovered with a fundamental frequency of 0.31GHz and an output power of 5.37μW, verifying the high repeatability and robustness of our device. The switching behavior measurement was successfully carried out, featuring rise and fall times in the order of picoseconds, which can be used in high-speed digital circuits. Limited by the measuring equipment and the layer structure, the switching time can be further improved. In general, this article presents a novel nitride device with multiple negative differential regions driven by the resonant tunneling mechanism, which can be used in high-speed multiple value logic field with reduced circuit complexity, demonstrating a new solution of nitride devices to break through the limitations of binary logic.Keywords: GaN resonant tunneling diode, negative differential resistance, multiple-valued logic system, switching time, peak-to-valley current ratio
Procedia PDF Downloads 99494 Influence of Surface Wettability on Imbibition Dynamics of Protein Solution in Microwells
Authors: Himani Sharma, Amit Agrawal
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Stability of the Cassie and Wenzel wetting states depends on intrinsic contact angle and geometric features on a surface that was exploited in capturing biofluids in microwells. However, the mechanism of imbibition of biofluids in the microwells is not well implied in terms of wettability of a substrate. In this work, we experimentally demonstrated filling dynamics in hydrophilic and hydrophobic microwells by protein solutions. Towards this, we utilized lotus leaf as a mold to fabricate microwells on a Polydimethylsiloxane (PDMS) surface. Lotus leaf containing micrometer-sized blunt-conical shaped pillars with a height of 8-15 µm and diameter of 3-8 µm were transferred on to PDMS. Furthermore, PDMS surface was treated with oxygen plasma to render the hydrophilic nature. A 10µL droplets containing fluorescein isothiocyanate (FITC) - labelled bovine serum albumin (BSA) were rested on both hydrophobic (θa = 108o, where θa is the apparent contact angle) and hydrophilic (θa = 60o) PDMS surfaces. A time-dependent fluorescence microscopy was conducted on these modified PDMS surfaces by recording the fluorescent intensity over a 5 minute period. It was observed that, initially (at t=1 min) FITC-BSA was accumulated on the periphery of both hydrophilic and hydrophobic microwells due to incomplete penetration of liquid-gas meniscus. This deposition of FITC-BSA on periphery of microwell was not changed with time for hydrophobic surfaces, whereas, a complete filling was occurred in hydrophilic microwells (at t=5 mins). This attributes to a gradual movement of three-phase contact line along the vertical surface of the hydrophilic microwells as compared to stable pinning in the hydrophobic microwells as confirmed by Surface Evolver simulations. In addition, if the cavities are presented on hydrophobic surfaces, air bubbles will be trapped inside the cavities once the aqueous solution is placed over these surfaces, resulting in the Cassie-Baxter wetting state. This condition hinders trapping of proteins inside the microwells. Thus, it is necessary to impart hydrophilicity to the microwell surfaces so as to induce the Wenzel state, such that, an entire solution will be fully in contact with the walls of microwells. Imbibition of microwells by protein solutions was analyzed in terms fluorescent intensity versus time. The present work underlines the importance of geometry of microwells and surface wettability of substrate in wetting and effective capturing of solid sub-phases in biofluids.Keywords: BSA, microwells, surface evolver, wettability
Procedia PDF Downloads 197493 Human Identification Using Local Roughness Patterns in Heartbeat Signal
Authors: Md. Khayrul Bashar, Md. Saiful Islam, Kimiko Yamashita, Yano Midori
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Despite having some progress in human authentication, conventional biometrics (e.g., facial features, fingerprints, retinal scans, gait, voice patterns) are not robust against falsification because they are neither confidential nor secret to an individual. As a non-invasive tool, electrocardiogram (ECG) has recently shown a great potential in human recognition due to its unique rhythms characterizing the variability of human heart structures (chest geometry, sizes, and positions). Moreover, ECG has a real-time vitality characteristic that signifies the live signs, which ensure legitimate individual to be identified. However, the detection accuracy of the current ECG-based methods is not sufficient due to a high variability of the individual’s heartbeats at a different instance of time. These variations may occur due to muscle flexure, the change of mental or emotional states, and the change of sensor positions or long-term baseline shift during the recording of ECG signal. In this study, a new method is proposed for human identification, which is based on the extraction of the local roughness of ECG heartbeat signals. First ECG signal is preprocessed using a second order band-pass Butterworth filter having cut-off frequencies of 0.00025 and 0.04. A number of local binary patterns are then extracted by applying a moving neighborhood window along the ECG signal. At each instant of the ECG signal, the pattern is formed by comparing the ECG intensities at neighboring time points with the central intensity in the moving window. Then, binary weights are multiplied with the pattern to come up with the local roughness description of the signal. Finally, histograms are constructed that describe the heartbeat signals of individual subjects in the database. One advantage of the proposed feature is that it does not depend on the accuracy of detecting QRS complex, unlike the conventional methods. Supervised recognition methods are then designed using minimum distance to mean and Bayesian classifiers to identify authentic human subjects. An experiment with sixty (60) ECG signals from sixty adult subjects from National Metrology Institute of Germany (NMIG) - PTB database, showed that the proposed new method is promising compared to a conventional interval and amplitude feature-based method.Keywords: human identification, ECG biometrics, local roughness patterns, supervised classification
Procedia PDF Downloads 404492 A Digital Twin Approach to Support Real-time Situational Awareness and Intelligent Cyber-physical Control in Energy Smart Buildings
Authors: Haowen Xu, Xiaobing Liu, Jin Dong, Jianming Lian
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Emerging smart buildings often employ cyberinfrastructure, cyber-physical systems, and Internet of Things (IoT) technologies to increase the automation and responsiveness of building operations for better energy efficiency and lower carbon emission. These operations include the control of Heating, Ventilation, and Air Conditioning (HVAC) and lighting systems, which are often considered a major source of energy consumption in both commercial and residential buildings. Developing energy-saving control models for optimizing HVAC operations usually requires the collection of high-quality instrumental data from iterations of in-situ building experiments, which can be time-consuming and labor-intensive. This abstract describes a digital twin approach to automate building energy experiments for optimizing HVAC operations through the design and development of an adaptive web-based platform. The platform is created to enable (a) automated data acquisition from a variety of IoT-connected HVAC instruments, (b) real-time situational awareness through domain-based visualizations, (c) adaption of HVAC optimization algorithms based on experimental data, (d) sharing of experimental data and model predictive controls through web services, and (e) cyber-physical control of individual instruments in the HVAC system using outputs from different optimization algorithms. Through the digital twin approach, we aim to replicate a real-world building and its HVAC systems in an online computing environment to automate the development of building-specific model predictive controls and collaborative experiments in buildings located in different climate zones in the United States. We present two case studies to demonstrate our platform’s capability for real-time situational awareness and cyber-physical control of the HVAC in the flexible research platforms within the Oak Ridge National Laboratory (ORNL) main campus. Our platform is developed using adaptive and flexible architecture design, rendering the platform generalizable and extendable to support HVAC optimization experiments in different types of buildings across the nation.Keywords: energy-saving buildings, digital twins, HVAC, cyber-physical system, BIM
Procedia PDF Downloads 107491 Enhancing Access to Microfinance for Housing Provision in the Informal Sector of North East Nigeria
Authors: Wilfred Emmannuel Dzasu, Sani Usman Kunya, Inuwa Yusuf Mohammed, Moses Jonathan Gambo
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The research aimed at investigating and identifying the strategies for enhancing access to microfinance for housing provision in the informal sector of North East Nigeria, with a focus on addressing the critical issue of housing poverty and lack of access to affordable housing finance among low-income households in the informal sector. The study employed an exploratory sequential mixed method design, combining both qualitative and quantitative data collection and analysis techniques. In the qualitative phase, 12 participants from microfinance institutions (MFIs) in four selected states (Adamawa, Bauchi, Gombe, and Taraba) were interviewed. The interviews were conducted using an interview guide with open-ended questions and were recorded with the consent of the respondents. In the quantitative phase, a survey strategy was adopted to collect data from 500 questionnaires distributed to informal sector workers (ISWs) in the study area. A total of 350 questionnaires were returned, representing a 70.0% response rate. The most preferred strategy for improving access to housing microfinance among ISWs is aggressive awareness of housing financing options by MFIs, with a mean score of 4.213; the most important strategy for improving access to housing microfinance among MFIs is close monitoring and adequate supervision of housing loan beneficiaries by MFIs, with a mean score of 4.675. The study identified several government-related strategies that are necessary for enhancing access to housing microfinance, including the provision of grants and subsidized intervention funds for housing, improvement in infrastructures to aid housing developments, and adequate measures for checking inflation/price fluctuation of building materials. The study also identified several MFI-related strategies that are necessary for enhancing access to housing microfinance, including deliberate expansion in the capital bases of MFIs, adequate training and capacity development of MFIs staff on relevant skills in housing micro-financing, and introduction of loan products that suit the incremental building needs of informal sector workers. Overall, the study highlights the need for a combination of government-related and MFI-related strategies to enhance access to microfinance for housing provision in the informal sector of North East Nigeria.Keywords: finanace, microfinance, housing, North East Nigeria
Procedia PDF Downloads 21490 An Exploratory Approach of the Latin American Migrants’ Urban Space Transformation of Antofagasta City, Chile
Authors: Carolina Arriagada, Yasna Contreras
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Since mid-2000, the migratory flows of Latin American migrants to Chile have been increasing constantly. There are two reasons that would explain why Chile is presented as an attractive country for the migrants. On the one hand, traditional centres of migrants’ attraction such as the United States and Europe have begun to close their borders. On the other hand, Chile exhibits relative economic and political stability, which offers greater job opportunities and better standard of living when compared to the migrants’ origin country. At the same time, the neoliberal economic model of Chile, developed under an extractive production of the natural resources, has privatized the urban space. The market regulates the growth of the fragmented and segregated cities. Then, the vulnerable population, most of the time, is located in the periphery and in the marginal areas of the urban space. In this aspect, the migrants have begun to occupy those degraded and depressed areas of the city. The problem raised is that the increase of the social spatial segregation could be also attributed to the migrants´ occupation of the marginal urban places of the city. The aim of this investigation is to carry out an analysis of the migrants’ housing strategies, which are transforming the marginal areas of the city. The methodology focused on the urban experience of the migrants, through the observation of spatial practices, ways of living and networks configuration in order to transform the marginal territory. The techniques applied in this study are semi–structured interviews in-depth interviews. The study reveals that the migrants housing strategies for living in the marginal areas of the city are built on a paradox way. On the one hand, the migrants choose proximity to their place of origin, maintaining their identity and customs. On the other hand, the migrants choose proximity to their social and familiar places, generating sense of belonging. In conclusion, the migration as international displacements under a globalized economic model increasing socio spatial segregation in cities is evidenced, but the transformation of the marginal areas is a fundamental resource of their integration migratory process. The importance of this research is that it is everybody´s responsibility not only the right to live in a city without any discrimination but also to integrate the citizens within the social urban space of a city.Keywords: migrations, marginal space, resignification, visibility
Procedia PDF Downloads 142489 Extension of the Simplified Theory of Plastic Zones for Analyzing Elastic Shakedown in a Multi-Dimensional Load Domain
Authors: Bastian Vollrath, Hartwig Hubel
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In case of over-elastic and cyclic loading, strain may accumulate due to a ratcheting mechanism until the state of shakedown is possibly achieved. Load history dependent numerical investigations by a step-by-step analysis are rather costly in terms of engineering time and numerical effort. In the case of multi-parameter loading, where various independent loadings affect the final state of shakedown, the computational effort becomes an additional challenge. Therefore, direct methods like the Simplified Theory of Plastic Zones (STPZ) are developed to solve the problem with a few linear elastic analyses. Post-shakedown quantities such as strain ranges and cyclic accumulated strains are calculated approximately by disregarding the load history. The STPZ is based on estimates of a transformed internal variable, which can be used to perform modified elastic analyses, where the elastic material parameters are modified, and initial strains are applied as modified loading, resulting in residual stresses and strains. The STPZ already turned out to work well with respect to cyclic loading between two states of loading. Usually, few linear elastic analyses are sufficient to obtain a good approximation to the post-shakedown quantities. In a multi-dimensional load domain, the approximation of the transformed internal variable transforms from a plane problem into a hyperspace problem, where time-consuming approximation methods need to be applied. Therefore, a solution restricted to structures with four stress components was developed to estimate the transformed internal variable by means of three-dimensional vector algebra. This paper presents the extension to cyclic multi-parameter loading so that an unlimited number of load cases can be taken into account. The theoretical basis and basic presumptions of the Simplified Theory of Plastic Zones are outlined for the case of elastic shakedown. The extension of the method to many load cases is explained, and a workflow of the procedure is illustrated. An example, adopting the FE-implementation of the method into ANSYS and considering multilinear hardening is given which highlights the advantages of the method compared to incremental, step-by-step analysis.Keywords: cyclic loading, direct method, elastic shakedown, multi-parameter loading, STPZ
Procedia PDF Downloads 161488 Analyzing the Risk Based Approach in General Data Protection Regulation: Basic Challenges Connected with Adapting the Regulation
Authors: Natalia Kalinowska
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The adoption of the General Data Protection Regulation, (GDPR) finished the four-year work of the European Commission in this area in the European Union. Considering far-reaching changes, which will be applied by GDPR, the European legislator envisaged two-year transitional period. Member states and companies have to prepare for a new regulation until 25 of May 2018. The idea, which becomes a new look at an attitude to data protection in the European Union is risk-based approach. So far, as a result of implementation of Directive 95/46/WE, in many European countries (including Poland) there have been adopted very particular regulations, specifying technical and organisational security measures e.g. Polish implementing rules indicate even how long password should be. According to the new approach from May 2018, controllers and processors will be obliged to apply security measures adequate to level of risk associated with specific data processing. The risk in GDPR should be interpreted as the likelihood of a breach of the rights and freedoms of the data subject. According to Recital 76, the likelihood and severity of the risk to the rights and freedoms of the data subject should be determined by reference to the nature, scope, context and purposes of the processing. GDPR does not indicate security measures which should be applied – in recitals there are only examples such as anonymization or encryption. It depends on a controller’s decision what type of security measures controller considered as sufficient and he will be responsible if these measures are not sufficient or if his identification of risk level is incorrect. Data protection regulation indicates few levels of risk. Recital 76 indicates risk and high risk, but some lawyers think, that there is one more category – low risk/now risk. Low risk/now risk data processing is a situation when it is unlikely to result in a risk to the rights and freedoms of natural persons. GDPR mentions types of data processing when a controller does not have to evaluate level of risk because it has been classified as „high risk” processing e.g. processing on a large scale of special categories of data, processing with using new technologies. The methodology will include analysis of legal regulations e.g. GDPR, the Polish Act on the Protection of personal data. Moreover: ICO Guidelines and articles concerning risk based approach in GDPR. The main conclusion is that an appropriate risk assessment is a key to keeping data safe and avoiding financial penalties. On the one hand, this approach seems to be more equitable, not only for controllers or processors but also for data subjects, but on the other hand, it increases controllers’ uncertainties in the assessment which could have a direct impact on incorrect data protection and potential responsibility for infringement of regulation.Keywords: general data protection regulation, personal data protection, privacy protection, risk based approach
Procedia PDF Downloads 251487 Suggestions to the Legislation about Medical Ethics and Ethics Review in the Age of Medical Artificial Intelligence
Authors: Xiaoyu Sun
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In recent years, the rapid development of Artificial Intelligence (AI) has extensively promoted medicine, pharmaceutical, and other related fields. The medical research and development of artificial intelligence by scientific and commercial organizations are on the fast track. The ethics review is one of the critical procedures of registration to get the products approved and launched. However, the SOPs for ethics review is not enough to guide the healthy and rapid development of artificial intelligence in healthcare in China. Ethical Review Measures for Biomedical Research Involving Human Beings was enacted by the National Health Commission of the People's Republic of China (NHC) on December 1st, 2016. However, from a legislative design perspective, it was neither updated timely nor in line with the trends of AI international development. Therefore, it was great that NHC published a consultation paper on the updated version on March 16th, 2021. Based on the most updated laws and regulations in the States and EU, and in-depth-interviewed 11 subject matter experts in China, including lawmakers, regulators, and key members of ethics review committees, heads of Regulatory Affairs in SaMD industry, and data scientists, several suggestions were proposed on top of the updated version. Although the new version indicated that the Ethics Review Committees need to be created by National, Provincial and individual institute levels, the review authorities of different levels were not clarified. The suggestion is that the precise scope of review authorities for each level should be identified based on Risk Analysis and Management Model, such as the complicated leading technology, gene editing, should be reviewed by National Ethics Review Committees, it will be the job of individual institute Ethics Review Committees to review and approve the clinical study with less risk such as an innovative cream to treat acne. Furthermore, to standardize the research and development of artificial intelligence in healthcare in the age of AI, more clear guidance should be given to data security in the layers of data, algorithm, and application in the process of ethics review. In addition, transparency and responsibility, as two of six principles in the Rome Call for AI Ethics, could be further strengthened in the updated version. It is the shared goal among all countries to manage well and develop AI to benefit human beings. Learned from the other countries who have more learning and experience, China could be one of the most advanced countries in artificial intelligence in healthcare.Keywords: biomedical research involving human beings, data security, ethics committees, ethical review, medical artificial intelligence
Procedia PDF Downloads 166486 Library Support for the Intellectually Disabled: Book Clubs and Universal Design
Authors: Matthew Conner, Leah Plocharczyk
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This study examines the role of academic libraries in support of the intellectually disabled (ID) in post-secondary education. With the growing public awareness of the ID, there has been recognition of their need for post-secondary educational opportunities. This was an unforeseen result for a population that has been associated with elementary levels of education, yet the reasons are compelling. After aging out of the school system, the ID need and deserve educational and social support as much as anyone. Moreover, the commitment to diversity in higher education rings hollow if this group is excluded. Yet, challenges remain to integrating the ID into a college curriculum. This presentation focuses on the role of academic libraries. Neglecting this vital resource for the support of the ID is not to be thought of, yet the library’s contribution is not clear. Library collections presume reading ability and libraries already struggle to meet their traditional goals with the resources available. This presentation examines how academic libraries can support post-secondary ID. For context, the presentation first examines the state of post-secondary education for the ID with an analysis of data on the United States compiled by the ThinkCollege! Project. Geographic Information Systems (GIS) and statistical analysis will show regional and methodological trends in post-secondary support of the ID which currently lack any significant involvement by college libraries. Then, the presentation analyzes a case study of a book club at the Florida Atlantic University (FAU) libraries which has run for several years. Issues such as the selection of books, effective pedagogies, and evaluation procedures will be examined. The study has found that the instruction pedagogies used by libraries can be extended through concepts of Universal Learning Design (ULD) to effectively engage the ID. In particular, student-centered, participatory methodologies that accommodate different learning styles have proven to be especially useful. The choice of text is complex and determined not only by reading ability but familiarity of subject and features of the ID’s developmental trajectory. The selection of text is not only a necessity but also promises to give insight into the ID. Assessment remains a complex and unresolved subject, but the voluntary, sustained, and enthusiastic attendance of the ID is an undeniable indicator. The study finds that, through the traditional library vehicle of the book club, academic libraries can support ID students through training in both reading and socialization, two major goals of their post-secondary education.Keywords: academic libraries, intellectual disability, literacy, post-secondary education
Procedia PDF Downloads 163485 An Analysis of the Recent Flood Scenario (2017) of the Southern Districts of the State of West Bengal, India
Authors: Soumita Banerjee
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The State of West Bengal is mostly watered by innumerable rivers, and they are different in nature in both the northern and the southern part of the state. The southern part of West Bengal is mainly drained with the river Bhagirathi-Hooghly, and its major distributaries and tributaries have divided this major river basin into many subparts like the Ichamati-Bidyadhari, Pagla-Bansloi, Mayurakshi-Babla, Ajay, Damodar, Kangsabati Sub-basin to name a few. These rivers basically drain the Districts of Bankura, Burdwan, Hooghly, Nadia and Purulia, Birbhum, Midnapore, Murshidabad, North 24-Parganas, Kolkata, Howrah and South 24-Parganas. West Bengal has a huge number of flood-prone blocks in the southern part of the state of West Bengal, the responsible factors for flood situation are the shape and size of the catchment area, its steep gradient starting from plateau to flat terrain, the river bank erosion and its siltation, tidal condition especially in the lower Ganga Basin and very low maintenance of the embankments which are mostly used as communication links. Along with these factors, DVC (Damodar Valley Corporation) plays an important role in the generation (with the release of water) and controlling the flood situation. This year the whole Gangetic West Bengal is being flooded due to high intensity and long duration rainfall, and the release of water from the Durgapur Barrage As most of the rivers are interstate in nature at times floods also take place with release of water from the dams of the neighbouring states like Jharkhand. Other than Embankments, there is no such structural measures for combatting flood in West Bengal. This paper tries to analyse the reasons behind the flood situation this year especially with the help of climatic data collected from the Indian Metrological Department, flood related data from the Irrigation and Waterways Department, West Bengal and GPM (General Precipitation Measurement) data for rainfall analysis. Based on the threshold value derived from the calculation of the past available flood data, it is possible to predict the flood events which may occur in the near future and with the help of social media it can be spread out within a very short span of time to aware the mass. On a larger or a governmental scale, heightening the settlements situated on the either banks of the river can yield a better result than building up embankments.Keywords: dam failure, embankments, flood, rainfall
Procedia PDF Downloads 222484 Conflicts of Interest in the Private Sector and the Significance of the Public Interest Test
Authors: Opemiposi Adegbulu
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Conflicts of interest is an elusive, diverse and engaging subject, a cross-cutting problem of governance; all levels of governance, ranging from local to global, public to corporate or financial sectors. In all these areas, its mismanagement could lead to the distortion of decision-making processes, corrosion of trust and the weakening of administration. According to Professor Peters, an expert in the area, conflict of interest, a problem at the root of many scandals has “become a pervasive ethical concern in our professional, organisational, and political life”. Conflicts of interest corrode trust, and like in the public sector, trust is mandatory for the market, consumers/clients, shareholders and other stakeholders in the private sector. However, conflicts of interest in the private sector are distinct and must be treated in like manner when regulatory efforts are made to address them. The research looks at identifying conflicts of interest in the private sector and differentiating them from those in the public sector. The public interest is submitted as a criterion which allows for such differentiation. This is significant because it would for the use of tailor-made or sector-specific approaches to addressing this complex issue. This is conducted through extensive review of literature and theories on the definition of conflicts of interest. This study will employ theoretical, doctrinal and comparative methods. The nature of conflicts of interest in the private sector will be explored, through an analysis of the public sector where the notion of conflicts of interest appears more clearly identified, reasons, why they are of business ethics concern, will be advanced, and then, once again, looking at public sector solutions and other solutions, the study will identify ways of mitigating and managing conflicts in the private sector. An exploration of public sector conflicts of interest and solutions will be carried out because the typologies of conflicts of interest in both sectors appear very similar at the core and thus, lessons can be learnt with regards to the management of these issues in the private sector. Conflicts of interest corrode trust, and like in the public sector, trust is mandatory for the market, consumers/clients, shareholders and other stakeholders in the private sector. This research will then focus on some specific challenges to understanding and identifying conflicts of interest in the private sector; origin, diverging theories, the psychological barrier to the definition, similarities with public sector conflicts of interest due to the notions of corrosion of trust, ‘being in a particular kind of situation,’ etc. The notion of public interest will be submitted as a key element at the heart of the distinction between public sector and private sector conflicts of interests. It will then be proposed that the appreciation of the notion of conflicts of interest differ according to sector, country to country, based on the public interest test, using the United Kingdom (UK), the United States of America (US), France and the Philippines as illustrations.Keywords: conflicts of interest, corporate governance, global governance, public interest
Procedia PDF Downloads 397483 Proposed Design of an Optimized Transient Cavity Picosecond Ultraviolet Laser
Authors: Marilou Cadatal-Raduban, Minh Hong Pham, Duong Van Pham, Tu Nguyen Xuan, Mui Viet Luong, Kohei Yamanoi, Toshihiko Shimizu, Nobuhiko Sarukura, Hung Dai Nguyen
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There is a great deal of interest in developing all-solid-state tunable ultrashort pulsed lasers emitting in the ultraviolet (UV) region for applications such as micromachining, investigation of charge carrier relaxation in conductors, and probing of ultrafast chemical processes. However, direct short-pulse generation is not as straight forward in solid-state gain media as it is for near-IR tunable solid-state lasers such as Ti:sapphire due to the difficulty of obtaining continuous wave laser operation, which is required for Kerr lens mode-locking schemes utilizing spatial or temporal Kerr type nonlinearity. In this work, the transient cavity method, which was reported to generate ultrashort laser pulses in dye lasers, is extended to a solid-state gain medium. Ce:LiCAF was chosen among the rare-earth-doped fluoride laser crystals emitting in the UV region because of its broad tunability (from 280 to 325 nm) and enough bandwidth to generate 3-fs pulses, sufficiently large effective gain cross section (6.0 x10⁻¹⁸ cm²) favorable for oscillators, and a high saturation fluence (115 mJ/cm²). Numerical simulations are performed to investigate the spectro-temporal evolution of the broadband UV laser emission from Ce:LiCAF, represented as a system of two homogeneous broadened singlet states, by solving the rate equations extended to multiple wavelengths. The goal is to find the appropriate cavity length and Q-factor to achieve the optimal photon cavity decay time and pumping energy for resonator transients that will lead to ps UV laser emission from a Ce:LiCAF crystal pumped by the fourth harmonics (266nm) of a Nd:YAG laser. Results show that a single ps pulse can be generated from a 1-mm, 1 mol% Ce³⁺-doped LiCAF crystal using an output coupler with 10% reflectivity (low-Q) and an oscillator cavity that is 2-mm long (short cavity). This technique can be extended to other fluoride-based solid-state laser gain media.Keywords: rare-earth-doped fluoride gain medium, transient cavity, ultrashort laser, ultraviolet laser
Procedia PDF Downloads 354482 Nanomaterials for Archaeological Stone Conservation: Re-Assembly of Archaeological Heavy Stones Using Epoxy Resin Modified with Clay Nanoparticles
Authors: Sayed Mansour, Mohammad Aldoasri, Nagib Elmarzugi, Nadia A. Al-Mouallimi
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The archaeological large stone used in construction of ancient Pharaonic tombs, temples, obelisks and other sculptures, always subject to physicomechanical deterioration and destructive forces, leading to their partial or total broken. The task of reassembling this type of artifact represent a big challenge for the conservators. Recently, the researchers are turning to new technologies to improve the properties of traditional adhesive materials and techniques used in re-assembly of broken large stone. The epoxy resins are used extensively in stone conservation and re-assembly of broken stone because of their outstanding mechanical properties. The introduction of nanoparticles to polymeric adhesives at low percentages may lead to substantial improvements of their mechanical performances in structural joints and large objects. The aim of this study is to evaluate the effectiveness of clay nanoparticles in enhancing the performances of epoxy adhesives used in re-assembly of archaeological massive stone by adding proper amounts of those nanoparticles. The nanoparticles reinforced epoxy nanocomposite was prepared by direct melt mixing with a nanoparticles content of 3% (w/v), and then mould forming in the form of rectangular samples, and used as adhesive for experimental stone samples. Scanning electron microscopy (SEM) was employed to investigate the morphology of the prepared nanocomposites, and the distribution of nanoparticles inside the composites. The stability and efficiency of the prepared epoxy-nanocomposites and stone block assemblies with new formulated adhesives were tested by aging artificially the samples under different environmental conditions. The effect of incorporating clay nanoparticles on the mechanical properties of epoxy adhesives was evaluated comparatively before and after aging by measuring the tensile, compressive, and Elongation strength tests. The morphological studies revealed that the mixture process between epoxy and nanoparticles has succeeded with a relatively homogeneous morphology and good dispersion in low nano-particles loadings in epoxy matrix was obtained. The results show that the epoxy-clay nanocomposites exhibited superior tensile, compressive, and Elongation strength. Moreover, a marked improvement of the mechanical properties of stone joints increased in all states by adding nano-clay to epoxy in comparison with pure epoxy resin.Keywords: epoxy resins, nanocomposites, clay nanoparticles, re-assembly, archaeological massive stones, mechanical properties
Procedia PDF Downloads 112481 The Illegal Architecture of Apartheid in Palestine
Authors: Hala Barakat
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Architecture plays a crucial role in the colonization and organization of spaces, as well as the preservation of cultures and history. As a result of 70 years of occupation, Palestinian land, culture, and history are endangered today. The government of Israel has used architecture to strangulate Palestinians out and seize their land. The occupation has managed to fragment the West Bank and cause sensible scars on the landscape by creating obstacles, barriers, watchtowers, checkpoints, walls, apartheid roads, border devices, and illegal settlements to unjustly claim land from its indigenous population. The apartheid architecture has divided the Palestinian social and urban fabric into pieces, similarly to the Bantustans. The architectural techniques and methods used by the occupation are evidence of prejudice, and while the illegal settlements remain to be condemned by the United Nations, little is being done to officially end this apartheid. Illegal settlements range in scale from individual units to established cities and house more than 60,000 Israeli settlers that immigrated from all over Europe and the United States. Often architecture by Israel is being directed towards expressing ideologies and serving as evidence of its political agenda. More than 78% of what was granted to Palestine after the development of the Green Line in 1948 is under Israeli occupation today. This project aims to map the illegal architecture as a criticism of governmental agendas in the West Bank and Historic Palestinian land. The paper will also discuss the resistance to the newly developed plan for the last Arab village in Jerusalem, Lifta. The illegal architecture has isolated Palestinians from each other and installed obstacles to control their movement. The architecture of occupation has no ethical or humane logic but rather entirely political, administrative, and it should not be left for the silenced architecture to tell the story. Architecture is not being used as a connecting device but rather a way to implement political injustice and spatial oppression. By narrating stories of the architecture of occupation, we can highlight the spatial injustice of the complex apartheid infrastructure. The Israeli government has managed to intoxicate architecture to serve as a divider between cultural groups, allowing the unlawful and unethical architecture to define its culture and values. As architects and designers, the roles we play in the development of illegal settlements must align with the spatial ethics we practice. Most importantly, our profession is not performing architecturally when we design a house with a particular roof color to ensure it would not be mistaken with a Palestinian house and be attacked accidentally.Keywords: apartheid, illegal architecture, occupation, politics
Procedia PDF Downloads 150480 Influence of Pretreatment Magnetic Resonance Imaging on Local Therapy Decisions in Intermediate-Risk Prostate Cancer Patients
Authors: Christian Skowronski, Andrew Shanholtzer, Brent Yelton, Muayad Almahariq, Daniel J. Krauss
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Prostate cancer has the third highest incidence rate and is the second leading cause of cancer death for men in the United States. Of the diagnostic tools available for intermediate-risk prostate cancer, magnetic resonance imaging (MRI) provides superior soft tissue delineation serving as a valuable tool for both diagnosis and treatment planning. Currently, there is minimal data regarding the practical utility of MRI for evaluation of intermediate-risk prostate cancer. As such, the National Comprehensive Cancer Network’s guidelines indicate MRI as optional in intermediate-risk prostate cancer evaluation. This project aims to elucidate whether MRI affects radiation treatment decisions for intermediate-risk prostate cancer. This was a retrospective study evaluating 210 patients with intermediate-risk prostate cancer, treated with definitive radiotherapy at our institution between 2019-2020. NCCN risk stratification criteria were used to define intermediate-risk prostate cancer. Patients were divided into two groups: those with pretreatment prostate MRI, and those without pretreatment prostate MRI. We compared the use of external beam radiotherapy, brachytherapy alone, brachytherapy boost, and androgen depravation therapy between the two groups. Inverse probability of treatment weighting was used to match the two groups for age, comorbidity index, American Urologic Association symptoms index, pretreatment PSA, grade group, and percent core involvement on prostate biopsy. Wilcoxon Rank Sum and Chi-squared tests were used to compare continuous and categorical variables. Of the patients who met the study’s eligibility criteria, 133 had a prostate MRI and 77 did not. Following propensity matching, there were no differences between baseline characteristics between the two groups. There were no statistically significant differences in treatments pursued between the two groups: 42% vs 47% were treated with brachytherapy alone, 40% vs 42% were treated with external beam radiotherapy alone, 18% vs 12% were treated with external beam radiotherapy with a brachytherapy boost, and 24% vs 17% received androgen deprivation therapy in the non-MRI and MRI groups, respectively. This analysis suggests that pretreatment MRI does not significantly impact radiation therapy or androgen deprivation therapy decisions in patients with intermediate-risk prostate cancer. Obtaining a pretreatment prostate MRI should be used judiciously and pursued only to answer a specific question, for which the answer is likely to impact treatment decision. Further follow up is needed to correlate MRI findings with their impacts on specific oncologic outcomes.Keywords: magnetic resonance imaging, prostate cancer, definitive radiotherapy, gleason score 7
Procedia PDF Downloads 87479 Evidence-Based Practices in Education: A General Review of the Literature on Elementary Classroom Setting
Authors: Carolina S. Correia, Thalita V. Thomé, Andersen Boniolo, Dhayana I. Veiga
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Evidence-based practices (EBP) in education is a set of principles and practices used to raise educational policy, it involves the integration of professional expertise in education with the best empirical evidence in making decisions about how to deliver instruction. The purpose of this presentation is to describe and characterize studies about EBP in education in elementary classroom setting. Data here presented is part of an ongoing systematic review research. Articles were searched and selected from four academic databases: ProQuest, Scielo, Science Direct and Capes. The search terms were evidence-based practices or program effectiveness, and education or teaching or teaching practices or teaching methods. Articles were included according to the following criteria: The studies were explicitly described as evidence-based or discussed the most effective practices in education, they discussed teaching practices in classroom context in elementary school level. Document excerpts were extracted and recorded in Excel, organized by reference, descriptors, abstract, purpose, setting, participants, type of teaching practice, study design and main results. The total amount of articles selected were 1.185, 569 articles from Proquest Research Library; 216 from CAPES; 251 from ScienceDirect and 149 from Scielo Library. The potentially relevant references were 178, from which duplicates were removed. The final number of articles analyzed was 140. From 140 articles, are 47 theoretical studies and 93 empirical articles. The following research design methods were identified: longitudinal intervention study, cluster-randomized trial, meta-analysis and pretest-posttest studies. From 140 articles, 103 studies were about regular school teaching and 37 were on special education teaching practices. In several studies, used as teaching method: active learning, content acquisition podcast (CAP), precision teaching (PT), mediated reading practice, speech therapist programs and peer-assisted learning strategies (PALS). The countries of origin of the studies were United States of America, United Kingdom, Panama, Sweden, Scotland, South Korea, Argentina, Chile, New Zealand and Brunei. The present study in is an ongoing project, so some representative findings will be discussed, providing further acknowledgment on the best teaching practices in elementary classroom setting.Keywords: best practices, children, evidence-based education, elementary school, teaching methods
Procedia PDF Downloads 331478 Chronic Hepatitis C Virus Screening: The Role, Strategies and Challenging of Primary Healthcare Faced to Augment and Identify Asymptomatic Infected Patients
Authors: Tarek K. Jalouta, Jolietta R. Holliman, Kathryn R. Burke, Kathleen M. Bewley-Thomas
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Background: Chronic hepatitis C virus (HCV) infection is one of the leading causes of liver cirrhosis and hepatocellular carcinoma. In the United States, HCV screening awareness, treatment, and linkage to care are under continues ascending progress. However, still millions of people are asymptomatically infected and undiagnosed yet. Through this community mission, we sought to identify the best and the newest strategies to identify those infected people to educate them, link them to care and cure them. Methods: We have identified patients that did not have a prior HCV screening in our Electronic medical record (EMR) including all our different hospital locations (South Suburban Chicago, Northern, Western and Central Indiana). Providing education to all Primary care/Gastroenterology/Infectious diseases providers and staff in the clinic to increase awareness of the HCV screening. Health-related quality of life, chronic clinical complications, and demographics data were collected for each patient. All outcomes of HCV antibody-reactive and HCV RNA–positive results were identified and statistically analyzed. Results: From July 2016 to July 2018 we screened 35,720 individuals of birth cohort in our different Franciscan’s health medical centers. Of the screened population, 986 (2.7%) individuals were HCV AB-reactive. Of those, 319 (1%) patients were HCV RNA-positive, and 264 patients were counseled and linked to providers. 34 patients initiated anti-HCV therapy with successful treatment. Conclusions: Our HCV screening augmentation project considered the largest screening program in the Midwest. Augmenting the HCV screening process through creating a Best Practice Alert (BPA) in the EMR (Epic Sys.) and point of care testing could be helpful. Although continued work is required, our team is working on increase screening through adding HCV test to CBC-Panels in Emergency Department settings, phone calls to all birth cohort individuals through Robo-Calling System aimed to reach 75,000 individuals by 2019. However, a better linkage to care and referral monitoring system to all HCV RNA positive patients is still needed, and access to therapy, especially for uninsured patients, is challenging.Keywords: chronic hepatitis C, chronic hepatitis C treatment, chronic hepatitis C screening, chronic hepatitis C prevention, liver cancer
Procedia PDF Downloads 124477 Geotechnical Education in the USA: A Comparative Analysis of Academic Schooling vs. Industry Needs in the Area of Earth Retaining Structures
Authors: Anne Lemnitzer, Eric Tavarez
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The academic rigor of the geotechnical engineering curriculum indicates strong institutional and geographical variations. Geotechnical engineering deals with the most challenging civil engineering material, as opposed to structural engineering, environmental studies, transportation engineering, and water resources. Yet, technical expectations posed by the practicing professional community do not necessarily consider the challenges inherent to the disparity in academic rigor and disciplinary differences. To recognize the skill shortages among current graduates as well as identify opportunities to better equip graduate students in specific fields of geotechnical engineering, a two-part survey was developed in collaboration with the Earth Retaining Structures (ERS) Committee of the American Society of Civil Engineers. Earth Retaining Structures are critical components of infrastructure systems and integral components to many major engineering projects. Within the geotechnical curriculum, Earth Retaining Structures is either taught as a separate course or major subject within a foundation design class. Part 1 of the survey investigated the breadth and depth of the curriculum with respect to ERS by requesting faculty across the United States to provide data on their curricular content, integration of practice-oriented course content, student preparation for professional licensing, and level of technical competency expected upon student graduation. Part 2 of the survey enables a comparison of training provided versus training needed. This second survey addressed practicing geotechnical engineers in all sectors of the profession (e.g., private engineering consulting, governmental agencies, contractors, suppliers/manufacturers) and collected data on the expectations with respect to technical and non-technical skills of engineering graduates entering the professional workforce. Results identified skill shortages in soft skills, critical thinking, analytical and language skills, familiarity with design codes and standards, and communication with various stakeholders. The data will be used to develop educational tools to advance the proficiency and expertise of geotechnical engineering students to meet and exceed the expectations of the profession and to stimulate a lifelong interest in advancing the field of geotechnical engineering.Keywords: geotechnical engineering, academic training, industry requirements, earth retaining structures
Procedia PDF Downloads 125476 The Study of Intangible Assets at Various Firm States
Authors: Gulnara Galeeva, Yulia Kasperskaya
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The study deals with the relevant problem related to the formation of the efficient investment portfolio of an enterprise. The structure of the investment portfolio is connected to the degree of influence of intangible assets on the enterprise’s income. This determines the importance of research on the content of intangible assets. However, intangible assets studies do not take into consideration how the enterprise state can affect the content and the importance of intangible assets for the enterprise`s income. This affects accurateness of the calculations. In order to study this problem, the research was divided into several stages. In the first stage, intangible assets were classified based on their synergies as the underlying intangibles and the additional intangibles. In the second stage, this classification was applied. It showed that the lifecycle model and the theory of abrupt development of the enterprise, that are taken into account while designing investment projects, constitute limit cases of a more general theory of bifurcations. The research identified that the qualitative content of intangible assets significant depends on how close the enterprise is to being in crisis. In the third stage, the author developed and applied the Wide Pairwise Comparison Matrix method. This allowed to establish that using the ratio of the standard deviation to the mean value of the elements of the vector of priority of intangible assets makes it possible to estimate the probability of a full-blown crisis of the enterprise. The author has identified a criterion, which allows making fundamental decisions on investment feasibility. The study also developed an additional rapid method of assessing the enterprise overall status based on using the questionnaire survey with its Director. The questionnaire consists only of two questions. The research specifically focused on the fundamental role of stochastic resonance in the emergence of bifurcation (crisis) in the economic development of the enterprise. The synergetic approach made it possible to describe the mechanism of the crisis start in details and also to identify a range of universal ways of overcoming the crisis. It was outlined that the structure of intangible assets transforms into a more organized state with the strengthened synchronization of all processes as a result of the impact of the sporadic (white) noise. Obtained results offer managers and business owners a simple and an affordable method of investment portfolio optimization, which takes into account how close the enterprise is to a state of a full-blown crisis.Keywords: analytic hierarchy process, bifurcation, investment portfolio, intangible assets, wide matrix
Procedia PDF Downloads 206475 Healthcare Learning From Near Misses in Aviation Safety
Authors: Nick Woodier, Paul Sampson, Iain Moppett
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Background: For years, healthcare across the world has recognised that patients are coming to harm from the very processes meant to help them. In response, healthcare tells itself that it needs to ‘be more like aviation.’ Aviation safety is highly regarded by those in healthcare and is seen as an exemplar. Specifically, healthcare is keen to learn from how aviation uses near misses to make their industry safer. Healthcare is rife with near misses; however, there has been little progress addressing them, with most research having focused on reporting. Addressing the factors that contribute to near misses will potentially help reduce the number of significant, harm patientsafety incidents. While the healthcare literature states the need to learn from aviation’s use of near misses, there is nothing that describes how best to do this. The authors, as part of a larger study of near-miss management in healthcare, sought to learn from aviation to develop principles for how healthcare can identify, report, and learn from near misses to improve patient safety. Methods: A Grounded Theory (GT) methodology, augmented by a scoping review, was used. Data collection included interviews, field notes, and the literature. The review protocol is accessible online. The GT aimed to develop theories about how aviation, amongst other safety-critical industries, manages near misses. Results: Twelve aviation interviews contributed to the GT across passenger airlines, air traffic control, and bodies involved in policy, regulation, and investigation. The scoping review identified 83 articles across a range of safety-critical industries, but only seven focused on aviation. The GT identified that aviation interprets the term ‘near miss’ in different ways, commonly using it to specifically refer to near-miss air collisions, also known as Airproxes. Other types of near misses exist, such as health and safety, but the reporting of these and the safety climate associated with them is not as mature. Safety culture in aviation was regularly discussed, with evidence that culture varies depending on which part of the industry is being considered (e.g., civil vs. business aviation). Near misses are seen as just one part of an extensive safety management system, but processes to support their reporting and their analysis are not consistent. Their value alone is also questionable, with the challenge to long-held beliefs originating from the ‘common cause hypothesis.’ Conclusions: There is learning that healthcare can take from how parts of aviation manage and learn from near misses. For example, healthcare would benefit from a formal safety management system that currently does not exist. However, it may not be as simple as ‘healthcare should learn from aviation’ due to variation in safety maturity across the industry. Healthcare needs to clarify how to incorporate near misses into learning and whether allocating resources to them is of value; it was heard that catastrophes have led to greater improvements in safety in aviation.Keywords: aviation safety, patient safety, near miss, safety management systems
Procedia PDF Downloads 147474 Modulating Photoelectrochemical Water-Splitting Activity by Charge-Storage Capacity of Electrocatalysts
Authors: Yawen Dai, Ping Cheng, Jian Ru Gong
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Photoelctrochemical (PEC) water splitting using semiconductors (SCs) provides a convenient way to convert sustainable but intermittent solar energy into clean hydrogen energy, and it has been regarded as one of most promising technology to solve the energy crisis and environmental pollution in modern society. However, the record energy conversion efficiency of a PEC cell (~3%) is still far lower than the commercialization requirement (~10%). The sluggish kinetics of oxygen evolution reaction (OER) half reaction on photoanodes is a significant limiting factor of the PEC device efficiency, and electrocatalysts (ECs) are always deposited on SCs to accelerate the hole injection for OER. However, an active EC cannot guarantee enhanced PEC performance, since the newly emerged SC-EC interface complicates the interfacial charge behavior. Herein, α-Fe2O3 photoanodes coated with Co3O4 and CoO ECs are taken as the model system to glean fundamental understanding on the EC-dependent interfacial charge behavior. Intensity modulated photocurrent spectroscopy and electrochemical impedance spectroscopy were used to investigate the competition between interfacial charge transfer and recombination, which was found to be dominated by the charge storage capacities of ECs. The combined results indicate that both ECs can store holes and increase the hole density on photoanode surface. It is like a double-edged sword that benefit the multi-hole participated OER, as well as aggravate the SC-EC interfacial charge recombination due to the Coulomb attraction, thus leading to a nonmonotonic PEC performance variation trend with the increasing surface hole density. Co3O4 has low hole storage capacity which brings limited interfacial charge recombination, and thus the increased surface holes can be efficiently utilized for OER to generate enhanced photocurrent. In contrast, CoO has overlarge hole storage capacity that causes severe interfacial charge recombination, which hinders hole transfer to electrolyte for OER. Therefore, the PEC performance of α-Fe2O3 is improved by Co3O4 but decreased by CoO despite the similar electrocatalytic activity of the two ECs. First-principle calculation was conducted to further reveal how the charge storage capacity depends on the EC’s intrinsic property, demonstrating that the larger hole storage capacity of CoO than that of Co3O4 is determined by their Co valence states and original Fermi levels. This study raises up a new strategy to manipulate interfacial charge behavior and the resultant PEC performance by the charge storage capacity of ECs, providing insightful guidance for the interface design in PEC devices.Keywords: charge storage capacity, electrocatalyst, interfacial charge behavior, photoelectrochemistry, water-splitting
Procedia PDF Downloads 139473 Language in Court: Ideology, Power and Cognition
Authors: Mehdi Damaliamiri
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Undoubtedly, the power of language is hardly a new topic; indeed, the persuasive power of language accompanied by ideology has long been recognized in different aspects of life. The two and a half thousand-year-old Bisitun inscriptions in Iran, proclaiming the victories of the Persian King, Darius, are considered by some historians to have been an early example of the use of propaganda. Added to this, the modern age is the true cradle of fully-fledged ideologies and the ongoing process of centrifugal ideologization. The most visible work on ideology today within the field of linguistics is “Critical Discourse Analysis” (CDA). The focus of CDA is on “uncovering injustice, inequality, taking sides with the powerless and suppressed” and making “mechanisms of manipulation, discrimination, demagogy, and propaganda explicit and transparent.” possible way of relating language to ideology is to propose that ideology and language are inextricably intertwined. From this perspective, language is always ideological, and ideology depends on the language. All language use involves ideology, and so ideology is ubiquitous – in our everyday encounters, as much as in the business of the struggle for power within and between the nation-states and social statuses. At the same time, ideology requires language. Its key characteristics – its power and pervasiveness, its mechanisms for continuity and for change – all come out of the inner organization of language. The two phenomena are homologous: they share the same evolutionary trajectory. To get a more robust portrait of the power and ideology, we need to examine its potential place in the structure, and consider how such structures pattern in terms of the functional elements which organize meanings in the clause. This is based on the belief that all grammatical, including syntactic, knowledge is stored mentally as constructions have become immensely popular. When the structure of the clause is taken into account, the power and ideology have a preference for Complement over Subject and Adjunct. The subject is a central interpersonal element in discourse: it is one of two elements that form the central interactive nub of a proposition. Conceptually, there are countless ways of construing a given event and linguistically, a variety of grammatical devices that are usually available as alternate means of coding a given conception, such as political crime and corruption. In the theory of construal, then, which, like transitivity in Halliday, makes options available, Cognitive Linguistics can offer a cognitive account of ideology in language, where ideology is made possible by the choices a language allows for representing the same material situation in different ways. The possibility of promoting alternative construals of the same reality means that any particular choice in representation is always ideologically constrained or motivated and indicates the perspective and interests of the text-producer.Keywords: power, ideology, court, discourse
Procedia PDF Downloads 163472 The Effect of Bisphenol A and Its Selected Analogues on Antioxidant Enzymes Activity in Human Erythrocytes
Authors: Aneta Maćczak, Bożena Bukowska, Jaromir Michałowicz
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Bisphenols are one of the most widely used chemical compounds worldwide. They are used in the manufacturing of polycarbonates, epoxy resins and thermal paper which are applied in plastic containers, bottles, cans, newspapers, receipt and other products. Among these compounds, bisphenol A (BPA) is produced in the highest amounts. There are concerns about endocrine impact of BPA and its other toxic effects including hepatotoxicity, neurotoxicity and carcinogenicity on human organism. Moreover, BPA is supposed to increase the incidence the obesity, diabetes and heart disease. For this reason the use of BPA in the production of plastic infant feeding bottles and some other consumers products has been restricted in the European Union and the United States. Nowadays, BPA analogues like bisphenol F (BPF) and bisphenol S (BPS) have been developed as alternative compounds. The replacement of BPA with other bisphenols contributed to the increase of the exposure of human population to these substances. Toxicological studies have mainly focused on BPA. In opposite, a small number of studies concerning toxic effects of BPA analogues have been realized, which makes impossible to state whether those substituents are safe for human health. Up to now, the mechanism of bisphenols action on the erythrocytes has not been elucidated. That is why, the aim of this study was to assess the effect of BPA and its selected analogues such as BPF and BPS on the activity of antioxidant enzymes, i.e. catalase (EC 1.11.1.6.), glutathione peroxidase (E.C.1.11.1.9) and superoxide dismutase (EC.1.15.1.1) in human erythrocytes. Red blood cells in respect to their function (transport of oxygen) and very well developed enzymatic and non-enzymatic antioxidative system, are useful cellular model to assess changes in redox balance. Erythrocytes were incubated with BPA, BPF and BPS in the concentration ranging from 0.5 to 100 µg/ml for 24 h. The activity of catalase was determined by the method of Aebi (1984). The activity of glutathione peroxidase was measured according to the method described by Rice-Evans et al. (1991), while the activity of superoxide dismutase (EC.1.15.1.1) was determined by the method of Misra and Fridovich (1972). The results showed that BPA and BPF caused changes in the antioxidative enzymes activities. BPA decreased the activity of examined enzymes in the concentration of 100 µg/ml. We also noted that BPF decreased the activity of catalase (5-100 µg/ml), glutathione peroxidase (50-100 µg/ml) and superoxide dismutase (25-100 µg/ml), while BPS did not cause statistically significant changes in investigated parameters. The obtained results suggest that BPA and BPF disrupt redox balance in human erythrocytes but the observed changes may occur in human organism only during occupational or subacute exposure to these substances.Keywords: antioxidant enzymes, bisphenol A, bisphenol a analogues, human erythrocytes
Procedia PDF Downloads 468471 Toxin-Producing Algae of Nigerian Coast, Gulf of Guinea
Authors: Medina O. Kadiri, Jeffrey U. Ogbebor
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Toxin-producing algae are algal species that produce potent toxins, which accumulate in food chains and cause various gastrointestinal and neurological illnesses in humans and other animals. They result in shellfish toxicity, ecosystem alteration, cause fish kills and mortality of other animals and humans, in addition to compromised product quality as well as decreased consumer confidence. Animals, including man, are directly exposed to toxins by absorbing toxins from the water via swimming, drinking water with toxins, or ingestion of algal species via feeding on contaminated seafood. These toxins, algal toxins, undergo bioaccumulation, biotransformation, biotransferrence, and biomagnification through the natural food chains and food webs, thereby endangering animals and humans. The Nigerian coast is situated on the Atlantic Ocean, the Gulf of Guinea, one of Africa’s five large marine ecosystems (LME), and studies on toxic algae in this ecosystem are generally lacking. Algal samples were collected from eight coastal states and ten locations spanning the Bight of Bonny and the Bight of Benin. A total of 70 species of toxin-producing algae were found in the coastal waters of Nigeria. There was a great variety of toxin-producing algae in the coastal waters of Nigeria. They were Domoic acid-producing forms (DSP), Saxitoxin-producing, Gonyautoxin-producing, and Yessotoxin-producing (all PSP). Others were Okadaic acid-producing, Dinophysistoxin-producing, and Palytoxin-producing, which are representatives of DSP; CFP was represented by Ciguatoxin-producing forms and NSP by Brevitoxin-producing species. Emerging or new toxins are comprising of Gymnodimines, Spirolides, Palytoxins, and Prorocentrolidess-producing algae. The CyanoToxin Poisoning (CTP) was represented by Anatoxin-, Microcystin-, Cylindrospermopsis-Lyngbyatoxin-, Nordularin-Applyssiatoxin and Debromoapplatoxin-producing species. The highest group was the Saxitoxin-producing species, followed by Microcystin-producing species, then Anatoxin-producing species. Gonyautoxin (PSP), Palytoxin (DSP), Emerging toxins, and Cylindrospermopsin -producing species had a very substantial representation. Only Ciguatoxin-producing species, Lyngbyatoxin-Nordularin, Applyssiatoxin, and Debromoapplatoxin-producing species were represented by one taxon each. The presence of such overwhelming diversity of toxin-producing algae on the Nigerian coast is a source of concern for fisheries, aquaculture, human health, and ecosystem services. Therefore routine monitoring of toxic and harmful algae is greatly recommended.Keywords: algal syndromes, Atlantic Ocean, harmful algae, Nigeria
Procedia PDF Downloads 203470 Shoreline Variation with Construction of a Pair of Training Walls, Ponnani Inlet, Kerala, India
Authors: Jhoga Parth, T. Nasar, K. V. Anand
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An idealized definition of shoreline is that it is the zone of coincidence of three spheres such as atmosphere, lithosphere, and hydrosphere. Despite its apparent simplicity, this definition in practice a challenge to apply. In reality, the shoreline location deviates continually through time, because of various dynamic factors such as wave characteristics, currents, coastal orientation and the bathymetry, which makes the shoreline volatile. This necessitates us to monitor the shoreline in a temporal basis. If shoreline’s nature is understood at particular coastal stretch, it need not be the same trend at the other location, though belonging to the same sea front. Shoreline change is hence a local phenomenon and has to be studied with great intensity considering as many factors involved as possible. Erosion and accretion of sediment are such natures of a shoreline, which needs to be quantified by comparing with its predeceasing variations and understood before implementing any coastal projects. In recent years, advent of Global Positioning System (GPS) and Geographic Information System (GIS) acts as an emerging tool to quantify the intra and inter annual sediment rate getting accreted or deposited compared to other conventional methods in regards with time was taken and man power. Remote sensing data, on the other hand, paves way to acquire historical sets of data where field data is unavailable with a higher resolution. Short term and long term period shoreline change can be accurately tracked and monitored using a software residing in GIS - Digital Shoreline Analysis System (DSAS) developed by United States Geological Survey (USGS). In the present study, using DSAS, End Point Rate (EPR) is calculated analyze the intra-annual changes, and Linear Rate Regression (LRR) is adopted to study inter annual changes of shoreline. The shoreline changes are quantified for the scenario during the construction of breakwater in Ponnani river inlet along Kerala coast, India. Ponnani is a major fishing and landing center located 10°47’12.81”N and 75°54’38.62”E in Malappuram district of Kerala, India. The rate of erosion and accretion is explored using satellite and field data. The full paper contains the rate of change of shoreline, and its analysis would provide us understanding the behavior of the inlet at the study area during the construction of the training walls.Keywords: DSAS, end point rate, field measurements, geo-informatics, shoreline variation
Procedia PDF Downloads 254469 Comprehensive Longitudinal Multi-omic Profiling in Weight Gain and Insulin Resistance
Authors: Christine Y. Yeh, Brian D. Piening, Sarah M. Totten, Kimberly Kukurba, Wenyu Zhou, Kevin P. F. Contrepois, Gucci J. Gu, Sharon Pitteri, Michael Snyder
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Three million deaths worldwide are attributed to obesity. However, the biomolecular mechanisms that describe the link between adiposity and subsequent disease states are poorly understood. Insulin resistance characterizes approximately half of obese individuals and is a major cause of obesity-mediated diseases such as Type II diabetes, hypertension and other cardiovascular diseases. This study makes use of longitudinal quantitative and high-throughput multi-omics (genomics, epigenomics, transcriptomics, glycoproteomics etc.) methodologies on blood samples to develop multigenic and multi-analyte signatures associated with weight gain and insulin resistance. Participants of this study underwent a 30-day period of weight gain via excessive caloric intake followed by a 60-day period of restricted dieting and return to baseline weight. Blood samples were taken at three different time points per patient: baseline, peak-weight and post weight loss. Patients were characterized as either insulin resistant (IR) or insulin sensitive (IS) before having their samples processed via longitudinal multi-omic technologies. This comparative study revealed a wealth of biomolecular changes associated with weight gain after using methods in machine learning, clustering, network analysis etc. Pathways of interest included those involved in lipid remodeling, acute inflammatory response and glucose metabolism. Some of these biomolecules returned to baseline levels as the patient returned to normal weight whilst some remained elevated. IR patients exhibited key differences in inflammatory response regulation in comparison to IS patients at all time points. These signatures suggest differential metabolism and inflammatory pathways between IR and IS patients. Biomolecular differences associated with weight gain and insulin resistance were identified on various levels: in gene expression, epigenetic change, transcriptional regulation and glycosylation. This study was not only able to contribute to new biology that could be of use in preventing or predicting obesity-mediated diseases, but also matured novel biomedical informatics technologies to produce and process data on many comprehensive omics levels.Keywords: insulin resistance, multi-omics, next generation sequencing, proteogenomics, type ii diabetes
Procedia PDF Downloads 427468 Analyzing the Impact of Local and International Artists in Creating Cultural Identity through Public Art: Case Study of Chicago Public Policies
Authors: Kaesha M. Freyaldenhoven
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Chicago is a city in the United States whose cultural identity is largely shaped by public art pieces. Quintessential public works created by internationally renown artists – such as Anish Kapoor’s Cloud Gate in Millennium Park and 'The Picasso' in Daley Plaza – have historically contributed to developing a shared sense of community. In 2017, the city implemented a policy titled 50x50 Neighborhood Arts Project under the Chicago Public Art Plan. The policy promotes investments in contemporary public art to elevate neighborhood cultural assets and create a sense of place. Exclusively community-based artists were commissioned to accomplish the mission of the policy. Administrators felt only local artists would be capable of capturing the true essence of a neighborhood through art. This paper discusses the relationship between the public art and the culture of its respective neighborhood through close examination of aesthetic formal properties and social significance. Research compares the role of international artists with the role of local artists in cultivating the identity of a city through site-specific artworks in Chicago. Methodology unites theoretical research on understanding art and its function in the public space with empirical research on Chicago-based works. Theoretical frameworks provide an art historical foundation to explore the manner in which physical properties convey meaning through the work itself and its placement in an urban setting. Empirical research that examines policy documentation and press announcements released by the Department of Cultural Affairs and Special Events investigates project selection processes pertaining to the artists and neighborhoods. Ethnographies and interviews of individuals from diverse social segments in contemporary Chicago society measure impacts of the works on respective populations. Findings demonstrate works created by local artists activate neighborhoods and inculcate a sense of pride among community residents. Works created by international artists garner widespread media attention that frames the city’s cultural identity across temporal and geographic zones. This research can be utilized to inform future cultural policies pertaining to the commission of public art.Keywords: Chicago, cultural policy, public art, urban art
Procedia PDF Downloads 127467 Coalescence of Insulin and Triglyceride/High Density Lipoprotein Cholesterol Ratio for the Derivation of a Laboratory Index to Predict Metabolic Syndrome in Morbid Obese Children
Authors: Orkide Donma, Mustafa M. Donma
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Morbid obesity is a health threatening condition particularly in children. Generally, it leads to the development of metabolic syndrome (MetS) characterized by central obesity, elevated fasting blood glucose (FBG), triglyceride (TRG), blood pressure values and suppressed high density lipoprotein cholesterol (HDL-C) levels. However, some ambiguities exist during the diagnosis of MetS in children below 10 years of age. Therefore, clinicians are in the need of some surrogate markers for the laboratory assessment of pediatric MetS. In this study, the aim is to develop an index, which will be more helpful during the evaluation of further risks detected in morbid obese (MO) children. A total of 235 children with normal body mass index (N-BMI), with varying degrees of obesity; overweight (OW), obese (OB), MO as well as MetS participated in this study. The study was approved by the Institutional Ethical Committee. Informed consent forms were obtained from the parents of the children. Obesity states of the children were classified using BMI percentiles adjusted for age and sex. For the purpose, tabulated data prepared by WHO were used. MetS criteria were defined. Systolic and diastolic blood pressure values were measured. Parameters related to glucose and lipid metabolisms were determined. FBG, insulin (INS), HDL-C, TRG concentrations were determined. Diagnostic Obesity Notation Model Assessment Laboratory (DONMALAB) Index [ln TRG/HDL-C*INS] was introduced. Commonly used insulin resistance (IR) indices such as Homeostatic Model Assessment for IR (HOMA-IR) as well as ratios such as TRG/HDL-C, TRG/HDL-C*INS, HDL-C/TRG*INS, TRG/HDL-C*INS/FBG, log, and ln versions of these ratios were calculated. Results were interpreted using statistical package program (SPSS Version 16.0) for Windows. The data were evaluated using appropriate statistical tests. The degree for statistical significance was defined as 0.05. 35 N, 20 OW, 47 OB, 97 MO children and 36 with MetS were investigated. Mean ± SD values of TRG/HDL-C were 1.27 ± 0.69, 1.86 ± 1.08, 2.15 ± 1.22, 2.48 ± 2.35 and 4.61 ± 3.92 for N, OW, OB, MO and MetS children, respectively. Corresponding values for the DONMALAB index were 2.17 ± 1.07, 3.01 ± 0.94, 3.41 ± 0.93, 3.43 ± 1.08 and 4.32 ± 1.00. TRG/HDL-C ratio significantly differed between N and MetS groups. On the other hand, DONMALAB index exhibited statistically significant differences between N and all the other groups except the OW group. This index was capable of discriminating MO children from those with MetS. Statistically significant elevations were detected in MO children with MetS (p < 0.05). Multiple parameters are commonly used during the assessment of MetS. Upon evaluation of the values obtained for N, OW, OB, MO groups and for MO children with MetS, the [ln TRG/HDL-C*INS] value was unique in discriminating children with MetS.Keywords: children, index, laboratory, metabolic syndrome, obesity
Procedia PDF Downloads 147466 Lung Tissue Damage under Diesel Exhaust Exposure: Modification of Proteins, Cells and Functions in Just 14 Days
Authors: Ieva Bruzauskaite, Jovile Raudoniute, Karina Poliakovaite, Danguole Zabulyte, Daiva Bironaite, Ruta Aldonyte
Abstract:
Introduction: Air pollution is a growing global problem which has been shown to be responsible for various adverse health outcomes. Immunotoxicity, such as dysregulated inflammation, has been proposed as one of the main mechanisms in air pollution-associated diseases. Chronic obstructive pulmonary disease (COPD) is among major morbidity and mortality causes worldwide and is characterized by persistent airflow limitation caused by the small airways disease (obstructive bronchiolitis) and irreversible parenchymal destruction (emphysema). Exact pathways explaining the air pollution induced and mediated disease states are still not clear. However, modern societies understand dangers of polluted air, seek to mitigate such effects and are in need for reliable biomarkers of air pollution. We hypothesise that post-translational modifications of structural proteins, e.g. citrullination, might be a good candidate biomarker. Thus, we have designed this study, where mice were exposed to diesel exhaust and the ongoing protein modifications and inflammation in lungs and other tissues were assessed. Materials And Methods: To assess the effects of diesel exhaust a in vivo study was designed. Mice (n=10) were subjected to everyday 2-hour exposure to diesel exhaust for 14 days. Control mice were treated the same way without diesel exhaust. The effects within lung and other tissues were assessed by immunohistochemistry of formalin-fixed and paraffin-embedded tissues. Levels of inflammation and citrullination related markers were investigated. Levels of parenchymal damage were also measured. Results: In vivo study corroborates our own data from in vitro and reveals diesel exhaust initiated inflammatory shift and modulation of lung peptidyl arginine deiminase 4 (PAD4), citrullination associated enzyme, levels. In addition, high levels of citrulline were observed in exposed lung tissue sections co-localising with increased parenchymal destruction. Conclusions: Subacute exposure to diesel exhaust renders mice lungs inflammatory and modifies certain structural proteins. Such structural changes of proteins may pave a pathways to lost/gain function of affected molecules and also propagate autoimmune processes within the lung and systemically.Keywords: air pollution, citrullination, in vivo, lungs
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