Search results for: modified Bessel functions
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Paper Count: 4837

Search results for: modified Bessel functions

457 Role of Community Youths in Conservation of Forests and Protected Areas of Bangladesh

Authors: Obaidul Fattah Tanvir, Zinat Ara Afroze

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Community living adjacent to forests and Protected Areas, especially in South Asian countries, have a common practice in extracting resources for their living and livelihoods. This extraction of resources, because the way it is done, destroys the biophysical features of the area. Deforestation, wildlife poaching, illegal logging, unauthorized hill cutting etc. are some of the serious issues of concern for the sustainability of the natural resources that has a direct impact on environment and climate as a whole. To ensure community involvement in conservation initiatives of the state, community based forest management, commonly known as Comanagement, has been in practice in 6 South Asian countries. These are -India, Nepal, Sri Lanka, Pakistan, Bhutan and Bangladesh. Involving community in forestry management was initiated first in Bangladesh in 1979 and reached as an effective co-management approach through a several paradigm shifts. This idea of Comanagement has been institutionalized through a Government Order (GO) by the Ministry of Environment and Forests, Government of Bangladesh on November 23, 2009. This GO clearly defines the structure and functions of Co-management and its different bodies. Bangladesh Forest Department has been working in association with community to conserve and manage the Forests and Protected areas of Bangladesh following this legal document. Demographically young people constitute the largest segment of population in Bangladesh. This group, if properly sensitized, can produce valuable impacts on the conservation initiatives, both by community and government. This study traced the major factors that motivate community youths to work effectively with different tiers of comanagement organizations in conservation of forests and Protected Areas of Bangladesh. For the purpose of this study, 3 FGDs were conducted with 30 youths from the community living around the Protected Areas of Cox’s bazar, South East corner of Bangladesh, who are actively involved in Co-management organizations. KII were conducted with 5 key officials of Forest Department stationed at Cox’s Bazar. 2 FGDs were conducted with the representatives of 7 Co-management organizations working in Cox’s Bazar region and approaches of different community outreach activities conducted for forest conservation by 3 private organizations and Projects have been reviewed. Also secondary literatures were reviewed for the history and evolution of Co-management in Bangladesh and six South Asian countries. This study found that innovative community outreach activities that are financed by public and private sectors involving youths and community as a whole have played a pivotal role in conservation of forests and Protected Areas of the region. This approach can be replicated in other regions of Bangladesh as well as other countries of South Asia where Co-Management exists in practice.

Keywords: community, co-management, conservation, forests, protected areas, youth

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456 Adult Learners’ Code-Switching in the EFL Classroom: An Analysis of Frequency and Type of Code-Switching

Authors: Elizabeth Patricia Beck

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Stepping into various English as foreign language classrooms, one will see some fundamental similarities. There will likely be groups of students working collaboratively, possibly sitting at tables together. They will be using a set coursebook or photocopies of materials developed by publishers or the teacher. The teacher will be carefully monitoring students’ behaviour and progress. The teacher will also likely be insisting that the students only speak English together, possibly having implemented a complex penalty and award systems to encourage this. This is communicative language teaching and it is commonly how foreign languages are taught around the world. Recently, there has been much interest in the codeswitching behaviour of learners in foreign or second language classrooms. It is a significant topic as it relates to second language acquisition theory, language teaching training and policy, and student expectations and classroom practice. Generally in an English as a foreign language context, an ‘English Only’ policy is the norm. This is based on historical factors, socio-political influence and theories surrounding language learning. The trend, however, is shifting and, based on these same factors, a re-examination of language use in the foreign language classroom is taking place. This paper reports the findings of an examination into the codeswitching behaviour of learners with a shared native language in an English classroom. Specifically, it addresses the question of classroom code-switching by adult learners in the EFL classroom during student-to-student, spoken interaction. Three generic categories of code switching are proposed based on published research and classroom practice. Italian adult learners at three levels were observed and patterns of language use were identified, recorded and analysed using the proposed categories. After observations were completed, a questionnaire was distributed to the students focussing on attitudes and opinions around language choice in the EFL classroom, specifically, the usefulness of L1 for specific functions in the classroom. The paper then investigates the relationship between learners’ foreign language proficiency and the frequency and type of code-switching that they engaged in, and the relationship between learners’ attitudes to classroom code-switching and their behaviour. Results show that code switching patterns underwent changes as the students’ level of English language proficiency improved, and that students’ attitudes towards code-switching generally correlated with their behaviour with some exceptions, however. Finally, the discussion focusses on the details of the language produced in observation, possible influencing factors that may affect the frequency and type of code switching that took place, and additional influencing factors that may affect students’ attitudes towards code switching in the foreign language classroom. An evaluation of the limitations of this study is offered and some suggestions are made for future research in this field of study.

Keywords: code-switching, EFL, second language aquisition, adult learners

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455 The Role of the Board of Directors and Chief Executive Officers in Leading and Embedding Corporate Social Responsibility within Corporate Governance Regulations

Authors: Khalid Alshaikh

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In recent years, leadership, Corporate Governance (CG) and Corporate Social Responsibility (CSR) have been under scrutiny in the Libyan society. Scholars and institutions have commenced investigating the possible resolutions they can arrange to alleviate the economic, social and environmental problems the war has produced. Thus far, these constructs requisite an in-depth reinvestigation, reconceptualization, and analysis to clearly reconstruct their rules and regulations. With the demise of Qaddafi’s regime, levels, degrees, and efforts to apply CG regulations have varied in public and private commercial banks. CSR is a new organizational culture that still designs its route within these financial institutions. Detaching itself from any notion of dictatorship and autocratic traits, leadership counts on transformational and transactional styles. Therefore, this paper investigates the extent to which the Board of Directors and Chief Executive Officers (CEOs) redefine these concepts and how they entrench CSR within the framework of CG. The research methodology used both public and private banks as a case study and qualitative research to interview ten Board of Directors (BoDs) and eleven Chief executive managers to explore how leadership, CG, and CSR are defined and how leadership integrates CSR into CG structures. The findings suggest that the CG framework in Libya still requires great efforts to be developed. Full CG code implementation appears daunting. Also, the CSR is still influenced by the power of religion. Nevertheless, the Islamic perspective is more consistent with the social contract concept of the CSR. The Libyan commercial banks do not solely focus on the economic side of maximizing profits, but also concentrate on its morality. The issue is that CSR activities are not enough to achieve good charity publicly and needs strategies to address major social issues. Moreover, leadership is more transformational and transactional and endeavors to make economic, social and environmental changes, but these changes are curtailed by tradition and traditional values dominating the Libyan social life where religious and tribal practices establish the relationship between leaders and their subordinates. Finally, the findings reveal that transformational and transactional leadership styles encourage the incorporation of CSR into the CG regulations. The boardroom and executive management have such a particular role in flagging up how embedded corporate Social responsibility is in organizational culture across the commercial banks, yet it is still important that the BoDs and CEOs need to do much more to embed corporate social responsibility through their core functions. They need to boost their standing to be more influential and make sure that the right discussions about CSR happen with the right stakeholders involved.

Keywords: board of directors, chief executive officers, corporate governance, corporate social responsibility

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454 A Sustainable Pt/BaCe₁₋ₓ₋ᵧZrₓGdᵧO₃ Catalyst for Dry Reforming of Methane-Derived from Recycled Primary Pt

Authors: Alessio Varotto, Lorenzo Freschi, Umberto Pasqual Laverdura, Anastasia Moschovi, Davide Pumiglia, Iakovos Yakoumis, Marta Feroci, Maria Luisa Grilli

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Dry reforming of Methane (DRM) is considered one of the most valuable technologies for green-house gas valorization thanks to the fact that through this reaction, it is possible to obtain syngas, a mixture of H₂ and CO in an H₂/CO ratio suitable for utilization in the Fischer-Tropsch process of high value-added chemicals and fuels. Challenges of the DRM process are the reduction of costs due to the high temperature of the process and the high cost of precious metals of the catalyst, the metal particles sintering, and carbon deposition on the catalysts’ surface. The aim of this study is to demonstrate the feasibility of the synthesis of catalysts using a leachate solution containing Pt coming directly from the recovery of spent diesel oxidation catalysts (DOCs) without further purification. An unusual perovskite support for DRM, the BaCe₁₋ₓ₋ᵧZrₓGdᵧO₃ (BCZG) perovskite, has been chosen as the catalyst support because of its high thermal stability and capability to produce oxygen vacancies, which suppress the carbon deposition and enhance the catalytic activity of the catalyst. BCZG perovskite has been synthesized by a sol-gel modified Pechini process and calcinated in air at 1100 °C. BCZG supports have been impregnated with a Pt-containing leachate solution of DOC, obtained by a mild hydrometallurgical recovery process, as reported elsewhere by some of the authors of this manuscript. For comparison reasons, a synthetic solution obtained by digesting commercial Pt-black powder in aqua regia was used for BCZG support impregnation. Pt nominal content was 2% in both BCZG-based catalysts formed by real and synthetic solutions. The structure and morphology of catalysts were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Thermogravimetric Analysis (TGA) was used to study the thermal stability of the catalyst’s samples. Brunauer-Emmett-Teller (BET) analysis provided a high surface area of the catalysts. H₂-TPR (Temperature Programmed Reduction) analysis was used to study the consumption of hydrogen for reducibility, and it was associated with H₂-TPD characterization to study the dispersion of Pt on the surface of the support and calculate the number of active sites used by the precious metal. Dry reforming of methane (DRM) reaction, carried out in a fixed bed reactor, showed a high conversion efficiency of CO₂ and CH4. At 850°C, CO₂ and CH₄ conversion were close to 100% for the catalyst obtained with the aqua regia-based solution of commercial Pt-black, and ~70% (for CH₄) and ~80 % (for CO₂) in the case of real HCl-based leachate solution. H₂/CO ratios were ~0.9 and ~0.70 in the first and latter cases, respectively. As far as we know, this is the first pioneering work in which a BCGZ catalyst and a real Pt-containing leachate solution were successfully employed for DRM reaction.

Keywords: dry reforming of methane, perovskite, PGM, recycled Pt, syngas

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453 Exploring the Entrepreneur-Function in Uncertainty: Towards a Revised Definition

Authors: Johan Esbach

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The entrepreneur has traditionally been defined through various historical lenses, emphasising individual traits, risk-taking, speculation, innovation and firm creation. However, these definitions often fail to address the dynamic nature of the modern entrepreneurial functions, which respond to unpredictable uncertainties and transition to routine management as certainty is achieved. This paper proposes a revised definition, positioning the entrepreneur as a dynamic function rather than a human construct, that emerges to address specific uncertainties in economic systems, but fades once uncertainty is resolved. By examining historical definitions and its limitations, including the works of Cantillon, Say, Schumpeter, and Knight, this paper identifies a gap in literature and develops a generalised definition for the entrepreneur. The revised definition challenges conventional thought by shifting focus from static attributes such as alertness, traits, firm creation, etc., to a dynamic role that includes reliability, adaptation, scalability, and adaptability. The methodology of this paper employs a mixed approach, combining theoretical analysis and case study examination to explore the dynamic nature of the entrepreneurial function in relation to uncertainty. The selection of case studies includes companies like Airbnb, Uber, Netflix, and Tesla, as these firms demonstrate a clear transition from entrepreneurial uncertainty to routine certainty. The data from the case studies is then analysed qualitatively, focusing on the patterns of entrepreneurial function across the selected companies. These results are then validated using quantitative analysis, derived from an independent survey. The primary finding of the paper will validate the entrepreneur as a dynamic function rather than a static, human-centric role. In considering the transition from uncertainty to certainty in companies like Airbnb, Uber, Netflix, and Tesla, the study shows that the entrepreneurial function emerges explicitly to address market, technological, or social uncertainties. Once these uncertainties are resolved and a certainty in the operating environment is established, the need for the entrepreneurial function ceases, giving way to routine management and business operations. The paper emphasises the need for a definitive model that responds to the temporal and contextualised nature of the entrepreneur. In adopting the revised definition, the entrepreneur is positioned to play a crucial role in the reduction of uncertainties within economic systems. Once the uncertainties are addressed, certainty is manifested in new combinations or new firms. Finally, the paper outlines policy implications for fostering environments that enables the entrepreneurial function and transition theory.

Keywords: dynamic function, uncertainty, revised definition, transition

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452 Mechanical Properties of Diamond Reinforced Ni Nanocomposite Coatings Made by Co-Electrodeposition with Glycine as Additive

Authors: Yanheng Zhang, Lu Feng, Yilan Kang, Donghui Fu, Qian Zhang, Qiu Li, Wei Qiu

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Diamond-reinforced Ni matrix composite has been widely applied in engineering for coating large-area structural parts owing to its high hardness, good wear resistance and corrosion resistance compared with those features of pure nickel. The mechanical properties of Ni-diamond composite coating can be promoted by the high incorporation and uniform distribution of diamond particles in the nickel matrix, while the distribution features of particles are affected by electrodeposition process parameters, especially the additives in the plating bath. Glycine has been utilized as an organic additive during the preparation of pure nickel coating, which can effectively increase the coating hardness. Nevertheless, to author’s best knowledge, no research about the effects of glycine on the Ni-diamond co-deposition has been reported. In this work, the diamond reinforced Ni nanocomposite coatings were fabricated by a co-electrodeposition technique from a modified Watt’s type bath in the presence of glycine. After preparation, the SEM morphology of the composite coatings was observed combined with energy dispersive X-ray spectrometer, and the diamond incorporation was analyzed. The surface morphology and roughness were obtained by a three-dimensional profile instrument. 3D-Debye rings formed by XRD were analyzed to characterize the nickel grain size and orientation in the coatings. The average coating thickness was measured by a digital micrometer to deduce the deposition rate. The microhardness was tested by automatic microhardness tester. The friction coefficient and wear volume were measured by reciprocating wear tester to characterize the coating wear resistance and cutting performance. The experimental results confirmed that the presence of glycine effectively improved the surface morphology and roughness of the composite coatings. By optimizing the glycine concentration, the incorporation of diamond particles was increased, while the nickel grain size decreased with increasing glycine. The hardness of the composite coatings was increased as the glycine concentration increased. The friction and wear properties were evaluated as the glycine concentration was optimized, showing a decrease in the wear volume. The wear resistance of the composite coatings increased as the glycine content was increased to an optimum value, beyond which the wear resistance decreased. Glycine complexation contributed to the nickel grain refinement and improved the diamond dispersion in the coatings, both of which made a positive contribution to the amount and uniformity of embedded diamond particles, thus enhancing the microhardness, reducing the friction coefficient, and hence increasing the wear resistance of the composite coatings. Therefore, additive glycine can be used during the co-deposition process to improve the mechanical properties of protective coatings.

Keywords: co-electrodeposition, glycine, mechanical properties, Ni-diamond nanocomposite coatings

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451 Freshwater Cyanobacterial Bioactive Insights: Planktothricoides raciorskii Compounds vs. Green Synthesized Silver Nanoparticles: Characterization, in vitro Cytotoxicity, and Antibacterial Exploration

Authors: Sujatha Edla

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Introduction: New compounds and possible uses for the bioactive substances produced by freshwater cyanobacteria are constantly being discovered through research. Certain molecules are hazardous to the environment and human health, but others have potential applications in industry, biotechnology, and pharmaceuticals. These discoveries advance our knowledge of the varied functions these microbes perform in different ecosystems. Cyanobacterial silver nanoparticles (AgNPs) have special qualities and possible therapeutic advantages, which make them very promising for a range of medicinal uses. Aim: In our study; the attention was focused on the analysis and characterization of bioactive compounds extracted from freshwater cyanobacteria Planktothricoides raciorskii and its comparative study on Cyanobacteria-mediated silver nanoparticles synthesized by cell-free extract of Planktothricoides raciorskii. Material and Methods: A variety of bioactive secondary metabolites have been extracted, purified, and identified from cyanobacterial species using column chromatography, FTIR, and GC-MS/MS chromatography techniques and evaluated for antibacterial and cytotoxic studies, where the Cyanobacterial silver nanoparticles (CSNPs) were characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) analysis and were further tested for antibacterial and cytotoxic efficiency. Results: The synthesis of CSNPs was confirmed through visible color change and shift of peaks at 430–445 nm by UV-Vis spectroscopy. The size of CSNPs was between 22 and 34 nm and oval-shaped which were confirmed by SEM and TEM analyses. The FTIR spectra showed a new peak at the range of 3,400–3,460 cm−1 compared to the control, confirming the reduction of silver nitrate. The antibacterial activity of both crude bioactive compound extract and CSNPs showed remarkable activity with Zone of inhibition against E. coli with 9.5mm and 10.2mm, 13mm and 14.5mm against S. paratyphi, 9.2mm and 9.8mm zone of inhibition against K. pneumonia by both crude extract and CSNPs, respectively. The cytotoxicity as evaluated by extracts of Planktothricoides raciorskii against MCF7-Human Breast Adenocarcinoma cell line and HepG2- Human Hepatocellular Carcinoma cell line employing MTT assay gave IC50 value of 47.18ug/ml, 110.81ug/ml against MCF7cell line and HepG2 cell line, respectively. The cytotoxic evaluation of Planktothricoides raciorskii CSNPs against the MCF7cell line was 43.37 ug/ml and 20.88 ug/ml against the HepG2 cell line. Our ongoing research in this field aims to uncover the full therapeutic potential of cyanobacterial silver nanoparticles and address any associated challenges.

Keywords: cyanobacteria, silvernanoparticles, pharmaceuticals, bioactive compounds, cytotoxic

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450 An Analytical Metric and Process for Critical Infrastructure Architecture System Availability Determination in Distributed Computing Environments under Infrastructure Attack

Authors: Vincent Andrew Cappellano

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In the early phases of critical infrastructure system design, translating distributed computing requirements to an architecture has risk given the multitude of approaches (e.g., cloud, edge, fog). In many systems, a single requirement for system uptime / availability is used to encompass the system’s intended operations. However, when architected systems may perform to those availability requirements only during normal operations and not during component failure, or during outages caused by adversary attacks on critical infrastructure (e.g., physical, cyber). System designers lack a structured method to evaluate availability requirements against candidate system architectures through deep degradation scenarios (i.e., normal ops all the way down to significant damage of communications or physical nodes). This increases risk of poor selection of a candidate architecture due to the absence of insight into true performance for systems that must operate as a piece of critical infrastructure. This research effort proposes a process to analyze critical infrastructure system availability requirements and a candidate set of systems architectures, producing a metric assessing these architectures over a spectrum of degradations to aid in selecting appropriate resilient architectures. To accomplish this effort, a set of simulation and evaluation efforts are undertaken that will process, in an automated way, a set of sample requirements into a set of potential architectures where system functions and capabilities are distributed across nodes. Nodes and links will have specific characteristics and based on sampled requirements, contribute to the overall system functionality, such that as they are impacted/degraded, the impacted functional availability of a system can be determined. A machine learning reinforcement-based agent will structurally impact the nodes, links, and characteristics (e.g., bandwidth, latency) of a given architecture to provide an assessment of system functional uptime/availability under these scenarios. By varying the intensity of the attack and related aspects, we can create a structured method of evaluating the performance of candidate architectures against each other to create a metric rating its resilience to these attack types/strategies. Through multiple simulation iterations, sufficient data will exist to compare this availability metric, and an architectural recommendation against the baseline requirements, in comparison to existing multi-factor computing architectural selection processes. It is intended that this additional data will create an improvement in the matching of resilient critical infrastructure system requirements to the correct architectures and implementations that will support improved operation during times of system degradation due to failures and infrastructure attacks.

Keywords: architecture, resiliency, availability, cyber-attack

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449 Hypoglossal Nerve Stimulation (Baseline vs. 12 months) for Obstructive Sleep Apnea: A Meta-Analysis

Authors: Yasmeen Jamal Alabdallat, Almutazballlah Bassam Qablan, Hamza Al-Salhi, Salameh Alarood, Ibraheem Alkhawaldeh, Obada Abunar, Adam Abdallah

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Obstructive sleep apnea (OSA) is a disorder caused by the repeated collapse of the upper airway during sleep. It is the most common cause of sleep-related breathing disorder, as OSA can cause loud snoring, daytime fatigue, or more severe problems such as high blood pressure, cardiovascular disease, coronary artery disease, insulin-resistant diabetes, and depression. The hypoglossal nerve stimulator (HNS) is an implantable medical device that reduces the occurrence of obstructive sleep apnea by electrically stimulating the hypoglossal nerve in rhythm with the patient's breathing, causing the tongue to move. This stimulation helps keep the patient's airways clear while they sleep. This systematic review and meta-analysis aimed to assess the clinical outcome of hypoglossal nerve stimulation as a treatment of obstructive sleep apnea. A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials was conducted from inception until August 2022. Studies assessing the following clinical outcomes (Apnea-Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Oxygen Desaturation Indices (ODI), (Oxygen Saturation (SaO2)) were pooled in the meta-analysis using Review Manager Software. We assessed the quality of studies according to the Cochrane risk-of-bias tool for randomized trials (RoB2), Risk of Bias In Non-randomized Studies - of Interventions (ROBINS-I), and a modified version of NOS for the non-comparative cohort studies.13 Studies (Six Clinical Trials and Seven prospective cohort studies) with a total of 817 patients were included in the meta-analysis. The results of AHI were reported in 11 studies examining OSA 696 patients. We found that there was a significant improvement in the AHI after 12 months of HNS (MD = 18.2 with 95% CI, (16.7 to 19.7; I2 = 0%); P < 0.00001). Further, 12 studies reported the results of ESS after 12 months of intervention with a significant improvement in the range of sleepiness among the examined 757 OSA patients (MD = 5.3 with 95% CI, (4.75 to 5.86; I2 = 65%); P < 0.0001). Moreover, nine studies involving 699 participants reported the results of FOSQ after 12 months of HNS with a significant reported improvement (MD = -3.09 with 95% CI, (-3.41 to 2.77; I2 = 0%); P < 0.00001). In addition, ten studies reported the results of ODI with a significant improvement after 12 months of HNS among the 817 examined patients (MD = 14.8 with 95% CI, (13.25 to 16.32; I2 = 0%); P < 000001). The Hypoglossal Nerve Stimulation showed a significant positive impact on obstructive sleep apnea patients after 12 months of therapy in terms of apnea-hypopnea index, oxygen desaturation indices, manifestations of the behavioral morbidity associated with obstructive sleep apnea, and functional status resulting from sleepiness.

Keywords: apnea, meta-analysis, hypoglossal, stimulation

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448 Effect of Germination on Nutritional Values of Isolates from Two Varieties (DAS and BS) of Under-Utilized Nigerian Cultivated Solojo Cowpea (Vigna Unguiculata L. Walp)

Authors: Henry O. Chibudike, Olubamike A. Adeyoju, Bolanle O. Oluwole, Kayode O. Adebowale, Bamidele I. Olu-Owolabi, Chinedum E. Chibudike

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Studies on the Mineral Content of Solojo Flour and Protein Isolates from the two varieties (DAS and BS) of Nigeria cultivated solojo cowpeas were conducted to determine their nutritional value. These inorganic elements or minerals were classified into 3 categories: the ultra-trace minerals, which are the third category; the microelements, also known as the trace minerals, in the second category; while the first category is the macro elements, also known as major minerals. Some of the macro-elements are Ca, P, Na and Cl; the second category, micro-elements include iron, copper, cobalt, potassium, magnesium, iodine, zinc, manganese, molybdenum, F, Cr, Se and S. Results show that the proportion of Sodium (Na) which is ingested into the body in the form of NaCl through food intake maintenance of body pH and to retain water ranged from 728.97 to 253.37 ppm (72.90 to 25.34 mg/100 g); 715.24 to 235.45 ppm; 735.28 to 270.37 ppm; 726.59 to 264.35ppm, for FFDAS, FFBS, DAS and BS respectively with all values of the germinated samples all bellow the control. While FFDAS iron content ranged from 4.25 to 13.50 mg/100 g; FFBS ranged from 3.15 to 12.56 mg/100 g; DAS ranged from 3.81 to 12.90 mg/100g; BS ranged from 3.42 to 9.40 mg/100 g. The values of the germinated flours were all greater than the ungerminated flour. Iron helps to transport oxygen round the body and also helps in red blood cells building and to convert food into needed energy by the body. While Manganese an element that is needed in micro quantity but necessary to convert food into energy, is also crucial for healthy bone and cartilage creation. Results also show that zinc quantity increased as germination proceeded, and the values ranged from 38.80 ppm to 230.00 ppm (3.880 mg/100 g to 23.00 mg/100 g; 0.003880% to 0.0230%); 40.84 to 250.01 ppm; 32.85 to 93.41 ppm; 37.07 to 115.00 ppm, for FFDAS, FFBS, DAS and BS respectively. The Ca content improved significantly (p<0.05) with sprouting; the value extended from 250.56 ppm to 760.03 ppm (25.056 to 76.00 mg/100g or 0.0251 to 0.0760 %); 400.40 to 998.22 ppm; 116.87 to 195.69 ppm; 113.48 to 220.75 ppm, for FFDAS, FFBS, DAS and BS respectively. Zinc element although needed at the micro level in the body, is essential for a strong immune system to keep the body in good health. It is also crucial for the maintenance of a healthy sense of taste and odor, while Calcium is critical for strong bones and teeth, blood coagulation, and muscle tightening and relaxation. Magnesium is needed to build enzymes and antioxidants and also for healthy bones, while Potassium is needed to maintain water balance, muscle movement, and nerve impulses. It functions in conjunction with Na to regulate blood pressure.

Keywords: Solojo cowpea, underutilized legumes, protein isolates, BS, DAS, ungerminated

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447 Combined Effect of Zinc Supplementation and Ascaridia galli Infection on Oxidative Status in Broiler Chicks

Authors: Veselin Nanev, Margarita Gabrashanska, Neli Tsocheva-Gaytandzieva

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Ascaridiasis in chicks is one of the major causes for the reduction in body weights, higher mortality, and reduction in egg production, worse meat quantity, pathological lesions, blood losses, and secondary infections. It is responsible for economic losses to the poultry. Despite being economically important parasite, little work has been carried out on the role of antioxidants in the pathogenesis of ascaridiasis. Zinc is a trace elements with multiple functions and one of them is its antioxidant ability. The aim of this study was to investigate the combined effect of organic zinc compound (2Gly.ZnCl22H20) and Ascaridia galli infection on the antioxidant status of broiler chicks. The activity of antioxidant enzymes superoxide dismutase, glutathione peroxidase, the level of lipid peroxidation, expressed by malonyl dialdexyde and plasma zinc in chicks experimentally infected with Ascaridia galli was investigated. Parasite burden was studied as well. The study was performed on 80 broiler chicks, Cobb 500 hybrids. They were divided into four groups – 1st group – control (non-treated and non-infected, 2nd group – infected with embryonated eggs of A. galli and without treatment, 3rd group- only treated with 2Gly.ZnCl22H20 compound and gr. 4 - infected and supplemented with Zn-compound. The chicks in gr. 2 and 4 were infected orally with 450 embryonated eggs of A.galli on day 14 post infection. The chicks from gr. 3 and 4 received 40 mg Zn compound /kg of feed after the 1st week of age during 10 days. All chicks were similarly fed, managed and killed at 60 day p.i. Helminthological, biochemical and statistical methods were applied. Reduced plasma Zn content was observed in the infected chicks compared to controls. Zinc supplementation did not restored the lower Zn content. Cu, Zn-SOD was decreased significantly in the infected chicks compared to controls. The GPx – activity was significantly increased in the infected chicks than the controls. Increased GPx activity together with decreased Cu/ZnSOD activity revealed unbalanced antioxidant defense capacity. The increased MDA level in chicks and changes in the activity of the enzymes showed a development of oxidative stress during the infection with A.galli. Zn compound supplementation has been shown to influence the activity of both antioxidant enzymes (SOD, GPx) and reduced MDA in the infected chicks. Organic zinc supplementation improved the antioxidant defense and protect hosts from oxidant destruction, but without any effect on the parasite burden. The number of helminths was similar in both groups. Zn supplementation did not changed the number of parasites. Administration of oral 2Gly.ZnCl22H20 compound has been shown to be useful in chicks infected with A. galli by its improvement of their antioxidant potential.

Keywords: Ascaridia galli, antioxidants, broiler chicks, zinc supplementation

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446 A Comparative Study of Environmental, Social and Economic Cross-Border Cooperation in Post-Conflict Environments: The Israel-Jordan Border

Authors: Tamar Arieli

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Cross-border cooperation has long been hailed as a means for stabilizing and normalizing relations between former enemies. Cooperation in problem-solving and realizing of local interests in post-conflict environments can indeed serve as a basis for developing dialogue and meaningful relations between neighbors across borders. Hence the potential for formerly sealed borders to serve as a basis for generating local and national perceptions of interdependence and as a buffer against the resume of conflict. Central questions which arise for policy-makers and third parties are how to facilitate cross-border cooperation and which areas of cooperation best serve to normalize post-conflict border regions. The Israel-Jordan border functions as a post-conflict border, in that it is a peaceful border since the 1994 Israel-Jordan peace treaty yet cross-border relations are defined but the highly securitized nature of the border region and the ongoing Arab-Israel regional conflict. This case study is based on long term qualitative research carried out in the border regions of both Israel and Jordan, which mapped and analyzed cross-border in a wide range of activities – social interactions sponsored by peace-facilitating NGOs, government sponsored agricultural cooperation, municipal initiated emergency planning in cross-border continuous urban settings, private cross-border business ventures and various environmental cooperative initiatives. These cooperative initiatives are evaluated through multiple interviews carried out with initiators and partners in cross-border cooperation as well as analysis of documentation, funding and media. These cooperative interactions are compared based on levels of cross-border local and official awareness and involvement as well as sustainability over time. This research identifies environmental cooperation as the most sustainable area of cross- border cooperation and as most conducive to generating perceptions of regional interdependence. This is a variation to the ‘New Middle East’ vision of business-based cooperation leading to conflict amelioration and regional stability. Environmental cooperation serving the public good rather than personal profit enjoys social legitimization even in the face of widespread anti-normalization sentiments common in the post-conflict environment. This insight is examined in light of philosophical and social aspects of the natural environment and its social perceptions. This research has theoretical implications for better understanding dynamics of cooperation and conflict, as well as practical ramifications for practitioners in border region policy and management.

Keywords: borders, cooperation, post-conflict, security

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445 MigrationR: An R Package for Analyzing Bird Migration Data Based on Satellite Tracking

Authors: Xinhai Li, Huidong Tian, Yumin Guo

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Bird migration is fantastic natural phenomenon. In recent years, the use of GPS transmitters has generated a vast amount of data, and the Movebank platform has made these data publicly accessible. For researchers, what they need are data analysis tools. Although there are approximately 90 R packages dedicated to animal movement analysis, the capacity for comprehensive processing of bird migration data remains limited. Hence, we introduce a novel package called migrationR. This package enables the calculation of movement speed, direction, changes in direction, flight duration, daily and annual movement distances. Furthermore, it can pinpoint the starting and ending dates of migration, estimate nest site locations and stopovers, and visualize movement trajectories at various time scales. migrationR distinguishes individuals through NMDS (non-metric multidimensional scaling) coordinates based on movement variables such as speed, flight duration, path tortuosity, and migration timing. A distinctive aspect of the package is the development of a hetero-occurrences species distribution model that takes into account the daily rhythm of individual birds across different landcover types. Habitat use for foraging and roosting differs significantly for many waterbirds. For example, White-naped Cranes at Poyang Lake in China typically forage in croplands and roost in shallow water areas. Both of these occurrence types are of equal importance. Optimal habitats consist of a combination of crop lands and shallow waters, whereas suboptimal habitats lack both, which necessitates birds to fly extensively. With migrationR, we conduct species distribution modeling for foraging and roosting separately and utilize the moving distance between crop lands and shallow water areas as an index of overall habitat suitability. This approach offers a more nuanced understanding of the habitat requirements for migratory birds and enhances our ability to analyze and interpret their movement patterns effectively. The functions of migrationR are demonstrated using our own tracking data of 78 White-naped Crane individuals from 2014 to 2023, comprising over one million valid locations in total. migrationR can be installed from a GitHub repository by executing the following command: remotes::install_github("Xinhai-Li/migrationR").

Keywords: bird migration, hetero-occurrences species distribution model, migrationR, R package, satellite telemetry

Procedia PDF Downloads 63
444 The Gut Microbiome in Cirrhosis and Hepatocellular Carcinoma: Characterization of Disease-Related Microbial Signature and the Possible Impact of Life Style and Nutrition

Authors: Lena Lapidot, Amir Amnon, Rita Nosenko, Veitsman Ella, Cohen-Ezra Oranit, Davidov Yana, Segev Shlomo, Koren Omry, Safran Michal, Ben-Ari Ziv

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Introduction: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related mortality worldwide. Liver Cirrhosis is the main predisposing risk factor for the development of HCC. The factor(s) influencing disease progression from Cirrhosis to HCC remain unknown. Gut microbiota has recently emerged as a major player in different liver diseases, however its association with HCC is still a mystery. Moreover, there might be an important association between the gut microbiota, nutrition, life style and the progression of Cirrhosis and HCC. The aim of our study was to characterize the gut microbial signature in association with life style and nutrition of patients with Cirrhosis, HCC-Cirrhosis and healthy controls. Design: Stool samples were collected from 95 individuals (30 patients with HCC, 38 patients with Cirrhosis and 27 age, gender and BMI-matched healthy volunteers). All participants answered lifestyle and Food Frequency Questionnaires. 16S rRNA sequencing of fecal DNA was performed (MiSeq Illumina). Results: There was a significant decrease in alpha diversity in patients with Cirrhosis (qvalue=0.033) and in patients with HCC-Cirrhosis (qvalue=0.032) compared to healthy controls. The microbiota of patients with HCC-cirrhosis compared to patients with Cirrhosis, was characterized by a significant overrepresentation of Clostridium (pvalue=0.024) and CF231 (pvalue=0.010) and lower expression of Alphaproteobacteria (pvalue=0.039) and Verrucomicrobia (pvalue=0.036) in several taxonomic levels: Verrucomicrobiae, Verrucomicrobiales, Verrucomicrobiaceae and the genus Akkermansia (pvalue=0.039). Furthermore, we performed an analysis of predicted metabolic pathways (Kegg level 2) that resulted in a significant decrease in the diversity of metabolic pathways in patients with HCC-Cirrhosis (qvalue=0.015) compared to controls, one of which was amino acid metabolism. Furthermore, investigating the life style and nutrition habits of patients with HCC-Cirrhosis, we found significant correlations between intake of artificial sweeteners and Verrucomicrobia (qvalue=0.12), High sugar intake and Synergistetes (qvalue=0.021) and High BMI and the pathogen Campylobacter (qvalue=0.066). Furthermore, overweight in patients with HCC-Cirrhosis modified bacterial diversity (qvalue=0.023) and composition (qvalue=0.033). Conclusions: To the best of the our knowledge, we present the first report of the gut microbial composition in patients with HCC-Cirrhosis, compared with Cirrhotic patients and healthy controls. We have demonstrated in our study that there are significant differences in the gut microbiome of patients with HCC-cirrhosis compared to Cirrhotic patients and healthy controls. Our findings are even more pronounced because the significantly increased bacteria Clostridium and CF231 in HCC-Cirrhosis weren't influenced by diet and lifestyle, implying this change is due to the development of HCC. Further studies are needed to confirm these findings and assess causality.

Keywords: Cirrhosis, Hepatocellular carcinoma, life style, liver disease, microbiome, nutrition

Procedia PDF Downloads 129
443 Optimization of MAG Welding Process Parameters Using Taguchi Design Method on Dead Mild Steel

Authors: Tadele Tesfaw, Ajit Pal Singh, Abebaw Mekonnen Gezahegn

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Welding is a basic manufacturing process for making components or assemblies. Recent welding economics research has focused on developing the reliable machinery database to ensure optimum production. Research on welding of materials like steel is still critical and ongoing. Welding input parameters play a very significant role in determining the quality of a weld joint. The metal active gas (MAG) welding parameters are the most important factors affecting the quality, productivity and cost of welding in many industrial operations. The aim of this study is to investigate the optimization process parameters for metal active gas welding for 60x60x5mm dead mild steel plate work-piece using Taguchi method to formulate the statistical experimental design using semi-automatic welding machine. An experimental study was conducted at Bishoftu Automotive Industry, Bishoftu, Ethiopia. This study presents the influence of four welding parameters (control factors) like welding voltage (volt), welding current (ampere), wire speed (m/min.), and gas (CO2) flow rate (lit./min.) with three different levels for variability in the welding hardness. The objective functions have been chosen in relation to parameters of MAG welding i.e., welding hardness in final products. Nine experimental runs based on an L9 orthogonal array Taguchi method were performed. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to investigate the welding characteristics of dead mild steel plate and used in order to obtain optimum levels for every input parameter at 95% confidence level. The optimal parameters setting was found is welding voltage at 22 volts, welding current at 125 ampere, wire speed at 2.15 m/min and gas flow rate at 19 l/min by using the Taguchi experimental design method within the constraints of the production process. Finally, six conformations welding have been carried out to compare the existing values; the predicated values with the experimental values confirm its effectiveness in the analysis of welding hardness (quality) in final products. It is found that welding current has a major influence on the quality of welded joints. Experimental result for optimum setting gave a better hardness of welding condition than initial setting. This study is valuable for different material and thickness variation of welding plate for Ethiopian industries.

Keywords: Weld quality, metal active gas welding, dead mild steel plate, orthogonal array, analysis of variance, Taguchi method

Procedia PDF Downloads 480
442 Chebyshev Collocation Method for Solving Heat Transfer Analysis for Squeezing Flow of Nanofluid in Parallel Disks

Authors: Mustapha Rilwan Adewale, Salau Ayobami Muhammed

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This study focuses on the heat transfer analysis of magneto-hydrodynamics (MHD) squeezing flow between parallel disks, considering a viscous incompressible fluid. The upper disk exhibits both upward and downward motion, while the lower disk remains stationary but permeable. By employing similarity transformations, a system of nonlinear ordinary differential equations is derived to describe the flow behavior. To solve this system, a numerical approach, namely the Chebyshev collocation method, is utilized. The study investigates the influence of flow parameters and compares the obtained results with existing literature. The significance of this research lies in understanding the heat transfer characteristics of MHD squeezing flow, which has practical implications in various engineering and industrial applications. By employing the similarity transformations, the complex governing equations are simplified into a system of nonlinear ordinary differential equations, facilitating the analysis of the flow behavior. To obtain numerical solutions for the system, the Chebyshev collocation method is implemented. This approach provides accurate approximations for the nonlinear equations, enabling efficient computations of the heat transfer properties. The obtained results are compared with existing literature, establishing the validity and consistency of the numerical approach. The study's major findings shed light on the influence of flow parameters on the heat transfer characteristics of the squeezing flow. The analysis reveals the impact of parameters such as magnetic field strength, disk motion amplitude, fluid viscosity on the heat transfer rate between the disks, the squeeze number(S), suction/injection parameter(A), Hartman number(M), Prandtl number(Pr), modified Eckert number(Ec), and the dimensionless length(δ). These findings contribute to a comprehensive understanding of the system's behavior and provide insights for optimizing heat transfer processes in similar configurations. In conclusion, this study presents a thorough heat transfer analysis of magneto-hydrodynamics squeezing flow between parallel disks. The numerical solutions obtained through the Chebyshev collocation method demonstrate the feasibility and accuracy of the approach. The investigation of flow parameters highlights their influence on heat transfer, contributing to the existing knowledge in this field. The agreement of the results with previous literature further strengthens the reliability of the findings. These outcomes have practical implications for engineering applications and pave the way for further research in related areas.

Keywords: squeezing flow, magneto-hydro-dynamics (MHD), chebyshev collocation method(CCA), parallel manifolds, finite difference method (FDM)

Procedia PDF Downloads 75
441 An Analysis of Fundamentals and Factors of Positive Thinking and the Ways of Its Emergence in Islam and the New Testament

Authors: Zahra Mohagheghian, Fatema Agharebparast

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The comparative study of religions is one of the ways which provides peace and makes the believers of religions closer together. Finding the common notions could be a foundation for the dialog among the monotheistic religions and a background to eliminate the misunderstandings and to reach common point of views. The cornerstone of all the common efforts of the believers of the religions is to reach an understanding for building a better world where true peace is established. So, the article seeks to verify the notion of positive thinking in the religious resources of Islam and Christianity. In order to understand the foundations of the religious teachings and to provide a better understanding among the believers, then, the article tries to discover the common fundamentals and the opposing points about the positive thinking in these two religions. We first try to explain the notion of positive thinking in Islam and Christianity and then offer recommended ways in both religions to create and to strengthen this way of thinking. As the different parts of the New Testament is not theologically homogeneous, this collection has been verified and explained in four different parts: Three Gospels (Matthew, Mark and Luke), John's thoughts, thoughts and ideas of Paul and finally the Christian sects . The findings of the survey show that the notion of positive thinking in the monotheistic religions of Islam and Christianity can be traced back by the keyword "hope". It is only the hope which could finally create the soul of positive attitude and thinking inside the humankind. This hope is accompanied by the prospect and causes the humankind to work hard to reach their goals. However, there are some opposing points in these two religions about the basic foundation of this true hope. From the Quran viewpoint, the main foundation of the hope is God and the human is obliged to follow his worldly goals in accordance with this foundation as well as faith to God and avoidance of committing sins. On the other hand, the basic foundation of hope in the Three Gospels (Matthew, Mark and Luke) and the teachings of Paul is the promise of a coming Kingdom. Although there are some opposing views about the meaning of this as well as the ways to attain this hope, this hope is generally related to the purpose of human life and afterlife. The Christ, in the John's thoughts, is the source of hope and everybody, believing in God, must also have hope for Jesus Christ. Effects and functions of such hope are strengthening the spirit of love and kindness to others. Hence, in Christianity, the hope and positive thinking about the future, along with good deeds, reflects different viewpoints. On the other hand, in Quran, this is faith to God and fulfilling the Sharia orders which ignite and strengthen this hope and way of thinking. This is the base that continues nowadays with Vilāya and the love for Ahlulbeit in the Shiite views.

Keywords: God, new testament, positive thinking, Quran

Procedia PDF Downloads 453
440 The Impact of Neuroscience Knowledge on the Field of Education

Authors: Paula Andrea Segura Delgado, Martha Helena Ramírez-Bahena

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Research on how the brain learns has a transcendental application in the educational context. It is crucial for teacher training to understand the nature of brain changes and their direct influence on learning processes. This communication is based on a literature review focused on neuroscience, neuroeducation, and the impact of digital technology on the human brain. Information was gathered from both English and Spanish language sources, using online journals, books and reports. The general objective was to analyze the role of neuroscience knowledge in enriching our understanding of the learning process. In fact, the authors have focused on the impact of digital technology on the human brain as well as its influence in the field of education..Neuroscience knowledge can contribute significantly to improving the training of educators and therefore educational practices. Education as an instrument of change and school as an agent of socialization, it is necessary to understand what it aims to transform: the human brain. Understanding the functioning of the human brain has important repercussions on education: this elucidates cognitive skills, psychological processes and elements that influence the learning process (memory, executive functions, emotions and the circadian cycle); helps identify psychological and neurological deficits that can impede learning processes (dyslexia, autism, hyperactivity); It allows creating environments that promote brain development and contribute to the advancement of brain capabilities in alignment with the stages of neurobiological development. The digital age presents diverse opportunities to every social environment. The frequent use of digital technology (DT) has had a significant and abrupt impact on both the cognitive abilities and physico-chemical properties of the brain, significantly influencing educational processes. Hence, educational community, with the insights from advances in neuroscience, aspire to identify the positive and negative effects of digital technology on the human brain. This knowledge helps ensure the alignment of teacher training and practices with these findings. The knowledge of neuroscience enables teachers to develop teaching methods that are aligned with the way the brain works. For example, neuroscience research has shown that digital technology is having a significant impact on the human brain (addition, anxiety, high levels of dopamine, circadian cycle disorder, decrease in attention, memory, concentration, problems with their social relationships). Therefore, it is important to understand the nature of these changes, their impact on the learning process, and how educators should effectively adapt their approaches based on these brain's changes.

Keywords: digital technology, learn process, neuroscience knowledge, neuroeducation, training proffesors

Procedia PDF Downloads 62
439 The Development of Traffic Devices Using Natural Rubber in Thailand

Authors: Weeradej Cheewapattananuwong, Keeree Srivichian, Godchamon Somchai, Wasin Phusanong, Nontawat Yoddamnern

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Natural rubber used for traffic devices in Thailand has been developed and researched for several years. When compared with Dry Rubber Content (DRC), the quality of Rib Smoked Sheet (RSS) is better. However, the cost of admixtures, especially CaCO₃ and sulphur, is higher than the cost of RSS itself. In this research, Flexible Guideposts and Rubber Fender Barriers (RFB) are taken into consideration. In case of flexible guideposts, the materials used are both RSS and DRC60%, but for RFB, only RSS is used due to the controlled performance tests. The objective of flexible guideposts and RFB is to decrease a number of accidents, fatal rates, and serious injuries. Functions of both devices are to save road users and vehicles as well as to absorb impact forces from vehicles so as to decrease of serious road accidents. This leads to the mitigation methods to remedy the injury of motorists, form severity to moderate one. The solution is to find the best practice of traffic devices using natural rubber under the engineering concepts. In addition, the performances of materials, such as tensile strength and durability, are calculated for the modulus of elasticity and properties. In the laboratory, the simulation of crashes, finite element of materials, LRFD, and concrete technology methods are taken into account. After calculation, the trials' compositions of materials are mixed and tested in the laboratory. The tensile test, compressive test, and weathering or durability test are followed and based on ASTM. Furthermore, the Cycle-Repetition Test of Flexible Guideposts will be taken into consideration. The final decision is to fabricate all materials and have a real test section in the field. In RFB test, there will be 13 crash tests, 7 Pickup Truck tests, and 6 Motorcycle Tests. The test of vehicular crashes happens for the first time in Thailand, applying the trial and error methods; for example, the road crash test under the standard of NCHRP-TL3 (100 kph) is changed to the MASH 2016. This is owing to the fact that MASH 2016 is better than NCHRP in terms of speed, types, and weight of vehicles and the angle of crash. In the processes of MASH, Test Level 6 (TL-6), which is composed of 2,270 kg Pickup Truck, 100 kph, and 25 degree of crash-angle is selected. The final test for real crash will be done, and the whole system will be evaluated again in Korea. The researchers hope that the number of road accidents will decrease, and Thailand will be no more in the top tenth ranking of road accidents in the world.

Keywords: LRFD, load and resistance factor design, ASTM, american society for testing and materials, NCHRP, national cooperation highway research program, MASH, manual for assessing safety hardware

Procedia PDF Downloads 128
438 Determination of the Informativeness of Instrumental Research Methods in Assessing Risk Factors for the Development of Renal Dysfunction in Elderly Patients with Chronic Ischemic Heart Disease

Authors: Aksana N. Popel, Volha A. Sujayeva, Olga V. Kоshlataja, Irеna S. Karpava

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Introduction: It is a known fact that cardiovascular pathology and its complications cause a more severe course and worse prognosis in patients with comorbid kidney pathology. Chronic kidney disease (CKD) is associated with inflammation, endothelial dysfunction, and increased activity of the sympathoadrenal system. This circumstance increases the risk of cardiovascular diseases and the progression of kidney pathology. The above determines the need to identify cardiorenal changes at early stages to reduce the risks of cardiovascular complications and the progression of CKD. Objective: To identify risk factors (RF) for the development of CKD in elderly patients with chronic ischemic heart disease (CIHD). Methods: The study included 64 patients (40 women and 24 men) with a mean age of 74.4±4.5 years with coronary heart disease, without a history of structural kidney pathology and CKD. All patients underwent transthoracic echocardiography (TTE) and kidney ultrasound (KU) using GE Vivid 9 equipment (GE HealthCare, USA), and cardiac computed tomography (CCT) using Siemens Somatom Force equipment (Siemens Healthineers AG, Germany) in 3 months and in 1 year. Data obtained were analyzed using multiple regression analysis and nonparametric Mann-Whitney test. Statistical analysis was performed using the STATISTICA 12.0 program (StatSoft Inc.). Results: Initially, CKD was not diagnosed in all patients. In 3 months, CKD was diagnosed: stage C1 had 11 people (18%), stage C2 had 4 people (6%), stage C3A had 11 people (18%), stage C3B had 2 people (3%). After 1 year, CKD was diagnosed: stage C1 had 22 people (35%), stage C2 had 5 people (8%), stage C3A had 17 people (27%), stage C3B had 10 people (15%). In 3 months, statistically significant (p<0.05) risk factors were: 1) according to TTE: mitral peak E-wave velocity (U=678, p=0.039), mitral E-velocity DT (U=514, p=0.0168), mitral peak A-wave velocity (U=682, p=0.013). In 1 year, statistically significant (p<0.05) risk factors were: according to TTE: left ventricular (LV) end-systolic volume in B-mode (U=134, p=0.006), LV end-diastolic volume in B-mode (U=177, p=0.04), LV ejection fraction in B-mode (U=135, p=0.006), left atrial volume (U=178, p=0.021), LV hypertrophy (U=294, p=0.04), mitral valve (MV) fibrosis (U=328, p=0.01); according CCT: epicardial fat thickness (EFT) on the right ventricle (U=8, p=0.015); according to KU: interlobar renal artery resistance index (RI) (U=224, p=0.02), segmental renal artery RI (U=409, p=0.016). Conclusions: Both TTE and KU are very informative methods to determine the additional risk factors of CKD development and progression. The most informative risk factors were LV global systolic and diastolic functions, LV and LA volumes. LV hypertrophy, MV fibrosis, interlobar renal artery and segmental renal artery RIs, EFT.

Keywords: chronic kidney disease, ischemic heart disease, prognosis, risk factors

Procedia PDF Downloads 25
437 A Therapeutic Approach for Bromhidrosis with Glycopyrrolate 2% Cream: Clinical Study of 20 Patients

Authors: Vasiliki Markantoni, Eftychia Platsidaki, Georgios Chaidemenos, Georgios Kontochristopoulos

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Introduction: Bromhidrosis, also known as osmidrosis, is a common distressing condition with a significant negative effect on patient’s quality of life. Its etiology is multifactorial. It usually affects axilla, genital skin, breasts and soles, areas where apocrine glands are mostly distributed. Therapeutic treatments include topical antibacterial agents, antiperspirants and neuromuscular blocker agents-toxins. In this study, we aimed to evaluate the efficacy and possible complications of topical glycopyrrolate, an anticholinergic agent, for treatment of bromhidrosis. Glycopyrrolate, applied topically as a cream, solution or spray at concentrations between 0,5% and 4%, has been successfully used to treat different forms of focal hyperhidrosis. Materials and Methods: Twenty patients, six males and fourteen females, meeting the criteria for bromhidrosis were treated with topical glycopyrrolate for two months. The average age was 36. Eleven patients had bromhidrosis located to the axillae, four to the soles, four to both axillae and soles and one to the genital folds. Glycopyrrolate was applied topically as a cream at concentration 2%, formulated in Fitalite. During the first month, patients were using the cream every night and thereafter twice daily. The degree of malodor was assessed subjectively by patients and scaled averagely as ‘none’, ‘mild’, ‘moderate’, and ‘severe’ with corresponding scores of 0, 1, 2, and 3, respectively. The modified Dermatology Life Quality Index (DLQI) was used to assess the quality of life. The clinical efficacy was graded by the patient scale of excellent, good, fair and poor. In the end, patients were given the power to evaluate whether they were totally satisfied with, partially satisfied or unsatisfied and possible side effects during the treatment were recorded. Results: All patients were satisfied at the end of the treatment. No patient defined the response as no improvement. The subjectively assessed score level of bromhidrosis was remarkably improved after the first month of treatment and improved slightly more after the second month. DLQI score was also improved to all patients. Adverse effects were reported in 2 patients. In the first case, topical irritation was reported. This was classed as mild (erythema and desquamation), appeared during the second month of treatment and was treated with low-potency topical corticosteroids. In the second case, mydriasis was reported, that recovered without specific treatment, as soon as we insisted to the importance of careful hygiene after cream application so as not to contaminate the periocular skin or ocular surface. Conclusions: Dermatologists often encounter patients with bromhidrosis, therefore should be aware of treatment options. To the best of our knowledge, this is the first study to evaluate the use of topical glycopyrrolate as a therapeutic approach for bromhidrosis. Our findings suggest that topical glycopyrrolate has an excellent safety profile and demonstrate encouraging results for the management of this distressful condition.

Keywords: Bromhidrosis, glycopyrrolate, topical treatment, osmidrosis

Procedia PDF Downloads 167
436 Fabrication of Highly Conductive Graphene/ITO Transparent Bi-Film through Chemical Vapor Deposition (CVD) and Organic Additives-Free Sol-Gel Techniques

Authors: Bastian Waduge Naveen Harindu Hemasiri, Jae-Kwan Kim, Ji-Myon Lee

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Indium tin oxide (ITO) remains the industrial standard transparent conducting oxides with better performances. Recently, graphene becomes as a strong material with unique properties to replace the ITO. However, graphene/ITO hybrid composite material is a newly born field in the electronic world. In this study, the graphene/ITO composite bi-film was synthesized by a two steps process. 10 wt.% tin-doped, ITO thin films were produced by an environmentally friendly aqueous sol-gel spin coating technique with economical salts of In(NO3)3.H2O and SnCl4 without using organic additives. The wettability and surface free energy (97.6986 mJ/m2) enhanced oxygen plasma treated glass substrates were used to form voids free continuous ITO film. The spin-coated samples were annealed at 600 0C for 1 hour under low vacuum conditions to obtained crystallized, ITO film. The crystal structure and crystalline phases of ITO thin films were analyzed by X-ray diffraction (XRD) technique. The Scherrer equation was used to determine the crystallite size. Detailed information about chemical composition and elemental composition of the ITO film were determined by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) coupled with FE-SEM respectively. Graphene synthesis was done under chemical vapor deposition (CVD) method by using Cu foil at 1000 0C for 1 min. The quality of the synthesized graphene was characterized by Raman spectroscopy (532nm excitation laser beam) and data was collected at room temperature and normal atmosphere. The surface and cross-sectional observation were done by using FE-SEM. The optical transmission and sheet resistance were measured by UV-Vis spectroscopy and four point probe head at room temperature respectively. Electrical properties were also measured by using V-I characteristics. XRD patterns reveal that the films contain the In2O3 phase only and exhibit the polycrystalline nature of the cubic structure with the main peak of (222) plane. The peak positions of In3d5/2 (444.28 eV) and Sn3d5/2 (486.7 eV) in XPS results indicated that indium and tin are in the oxide form only. The UV-visible transmittance shows 91.35 % at 550 nm with 5.88 x 10-3 Ωcm specific resistance. The G and 2D band in Raman spectroscopy of graphene appear at 1582.52 cm-1 and 2690.54 cm-1 respectively when the synthesized CVD graphene on SiO2/Si. The determined intensity ratios of 2D to G (I2D/IG) and D to G (ID/IG) were 1.531 and 0.108 respectively. However, the above-mentioned G and 2D peaks appear at 1573.57 cm-1 and 2668.14 cm-1 respectively when the CVD graphene on the ITO coated glass, the positions of G and 2D peaks were red shifted by 8.948 cm-1 and 22.396 cm-1 respectively. This graphene/ITO bi-film shows modified electrical properties when compares with sol-gel derived ITO film. The reduction of sheet resistance in the bi-film was 12.03 % from the ITO film. Further, the fabricated graphene/ITO bi-film shows 88.66 % transmittance at 550 nm wavelength.

Keywords: chemical vapor deposition, graphene, ITO, Raman Spectroscopy, sol-gel

Procedia PDF Downloads 260
435 A Public Health Perspective on Deradicalisation: Re-Conceptualising Deradicalisation Approaches

Authors: Erin Lawlor

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In 2008 Time magazine named terrorist rehabilitation as one of the best ideas of the year. The term deradicalisation has become synonymous with rehabilitation within security discourse. The allure for a “quick fix” when managing terrorist populations (particularly within prisons) has led to a focus on prescriptive programmes where there is a distinct lack of exploration into the drivers for a person to disengage or deradicalise from violence. It has been argued that to tackle a snowballing issue that interventions have moved too quickly for both theory development and methodological structure. This overly quick acceptance of a term that lacks rigorous testing, measuring, and monitoring means that there is distinct lack of evidence base for deradicalisation being a genuine process/phenomenon, leading to academics retrospectively attempting to design frameworks and interventions around a concept that is not truly understood. The UK Home Office has openly acknowledged the lack of empirical data on this subject. This lack of evidence has a direct impact on policy and intervention development. Extremism and deradicalisation are issues that affect public health outcomes on a global scale, to the point that terrorism has now been added to the list of causes of trauma, both in the direct form of being victim of an attack but also the indirect context of witnesses, children and ordinary citizens who live in daily fear. This study critiques current deradicalisation discourses to establish whether public health approaches offer opportunities for development. The research begins by exploring the theoretical constructs of both what deradicalisation, and public health issues are. Questioning: What does deradicalisation involve? Is there an evidential base on which deradicalisation theory has established itself? What theory are public health interventions devised from? What does success look like in both fields? From establishing this base, current deradicalisation practices will then be explored through examples of work already being carried out. Critiques can be broken into discussion points of: Language, the difficulties with conducting empirical studies and the issues around outcome measurements that deradicalisation interventions face. This study argues that a public health approach towards deradicalisation offers the opportunity to attempt to bring clarity to the definitions of radicalisation, identify what could be modified through intervention and offer insights into the evaluation of interventions. As opposed to simply focusing on an element of deradicalisation and analysing that in isolation, a public health approach allows for what the literature has pointed out is missing, a comprehensive analysis of current interventions and information on creating efficacy monitoring systems. Interventions, policies, guidance, and practices in both the UK and Australia will be compared and contrasted, due to the joint nature of this research between Sheffield Hallam University and La Trobe, Melbourne.

Keywords: radicalisation, deradicalisation, violent extremism, public health

Procedia PDF Downloads 66
434 Fatigue Truck Modification Factor for Design Truck (CL-625)

Authors: Mohamad Najari, Gilbert Grondin, Marwan El-Rich

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Design trucks in standard codes are selected based on the amount of damage they cause on structures-specifically bridges- and roads to represent the real traffic loads. Some limited numbers of trucks are run on a bridge one at a time and the damage on the bridge is recorded for each truck. One design track is also run on the same bridge “n” times -“n” is the number of trucks used previously- to calculate the damage of the design truck on the same bridge. To make these damages equal a reduction factor is needed for that specific design truck in the codes. As the limited number of trucks cannot be the exact representative of real traffic through the life of the structure, these reduction factors are not accurately calculated and they should be modified accordingly. Started on July 2004, the vehicle load data were collected in six weigh in motion (WIM) sites owned by Alberta Transportation for eight consecutive years. This database includes more than 200 million trucks. Having these data gives the opportunity to compare the effect of any standard fatigue trucks weigh and the real traffic load on the fatigue life of the bridges which leads to a modification for the fatigue truck factor in the code. To calculate the damage for each truck, the truck is run on the bridge, moment history of the detail under study is recorded, stress range cycles are counted, and then damage is calculated using available S-N curves. A 2000 lines FORTRAN code has been developed to perform the analysis and calculate the damages of the trucks in the database for all eight fatigue categories according to Canadian Institute of Steel Construction (CSA S-16). Stress cycles are counted using rain flow counting method. The modification factors for design truck (CL-625) are calculated for two different bridge configurations and ten span lengths varying from 1 m to 200 m. The two considered bridge configurations are single-span bridge and four span bridge. This was found to be sufficient and representative for a simply supported span, positive moment in end spans of bridges with two or more spans, positive moment in interior spans of three or more spans, and the negative moment at an interior support of multi-span bridges. The moment history of the mid span is recorded for single-span bridge and, exterior positive moment, interior positive moment, and support negative moment are recorded for four span bridge. The influence lines are expressed by a polynomial expression obtained from a regression analysis of the influence lines obtained from SAP2000. It is found that for design truck (CL-625) fatigue truck factor is varying from 0.35 to 0.55 depending on span lengths and bridge configuration. The detail results will be presented in the upcoming papers. This code can be used for any design trucks available in standard codes.

Keywords: bridge, fatigue, fatigue design truck, rain flow analysis, FORTRAN

Procedia PDF Downloads 521
433 Mechanism Design and Dynamic Analysis of Active Independent Front Steering System

Authors: Cheng-Chi Yu, Yu-Shiue Wang, Kei-Lin Kuo

Abstract:

Active Independent Front Steering system is a steering system which can according to vehicle driving situation adjusts the relation of steering angle between inner wheel and outer wheel. In low-speed cornering, AIFS sets the steering angles of inner and outer wheel into Ackerman steering geometry to make vehicle has less cornering radius. Besides, AIFS changes the steering geometry to parallel or even anti-Ackerman steering geometry to keep vehicle stability in high-speed cornering. Therefore, based on the analysis of the vehicle steering behavior from different steering geometries, this study develops a new screw type of active independent front steering system to make vehicles best cornering performance at any speeds. The screw type of active independent front steering system keeps the pinion and separates the rack into main rack and second rack. Two racks connect by a screw. Extra screw rotated motion powered by assistant motor through coupler makes second rack move relative to main rack, which can adjust both steering ratio and steering geometry. First of all, this study distinguishes the steering geometry by using Ackerman percentage and utilizes the software of ADAMS/Car to construct diverse steering geometry models. The different steering geometries are compared at low-speed and high-speed cornering, and then control strategies of the active independent front steering systems could be formulated. Secondly, this study applies closed loop equation to analyze tire steering angles and carries out optimization calculations to make the steering geometry from traditional rack and pinion steering system near to Ackerman steering geometry. Steering characteristics of the optimum steering mechanism and motion characteristics of vehicle installed the steering mechanism are verified by ADAMS/Car models of front suspension and full vehicle respectively. By adding dual auxiliary rack and dual motor to the optimum steering mechanism, the active independent front steering system could be developed to achieve the functions of variable steering ratio and variable steering geometry. At last, this study uses ADAMS/Car and Matlab/Simulink to co-simulate the cornering motion of vehicles confirms the vehicle installed the Active Independent Front Steering (AIFS) system has better handling performance than that with Active Independent Steering (AFS) system or with Electric Power Steering (EPS) system. At low-speed cornering, the vehicles with AIFS system and with AFS system have better maneuverability, less cornering radius, than the traditional vehicle with EPS system because that AIFS and AFS systems both provide function of variable steering ratio. However, there is a slight penalty in the motor(s) power consumption. In addition, because of the capability of variable steering geometry, the vehicle with AIFS system has better high-speed cornering stability, trajectory keeping, and even less motor(s) power consumption than that with EPS system and also with AFS system.

Keywords: active front steering system, active independent front steering system, steering geometry, steering ratio

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432 Folding of β-Structures via the Polarized Structure-Specific Backbone Charge (PSBC) Model

Authors: Yew Mun Yip, Dawei Zhang

Abstract:

Proteins are the biological machinery that executes specific vital functions in every cell of the human body by folding into their 3D structures. When a protein misfolds from its native structure, the machinery will malfunction and lead to misfolding diseases. Although in vitro experiments are able to conclude that the mutations of the amino acid sequence lead to incorrectly folded protein structures, these experiments are unable to decipher the folding process. Therefore, molecular dynamic (MD) simulations are employed to simulate the folding process so that our improved understanding of the folding process will enable us to contemplate better treatments for misfolding diseases. MD simulations make use of force fields to simulate the folding process of peptides. Secondary structures are formed via the hydrogen bonds formed between the backbone atoms (C, O, N, H). It is important that the hydrogen bond energy computed during the MD simulation is accurate in order to direct the folding process to the native structure. Since the atoms involved in a hydrogen bond possess very dissimilar electronegativities, the more electronegative atom will attract greater electron density from the less electronegative atom towards itself. This is known as the polarization effect. Since the polarization effect changes the electron density of the two atoms in close proximity, the atomic charges of the two atoms should also vary based on the strength of the polarization effect. However, the fixed atomic charge scheme in force fields does not account for the polarization effect. In this study, we introduce the polarized structure-specific backbone charge (PSBC) model. The PSBC model accounts for the polarization effect in MD simulation by updating the atomic charges of the backbone hydrogen bond atoms according to equations derived between the amount of charge transferred to the atom and the length of the hydrogen bond, which are calculated from quantum-mechanical calculations. Compared to other polarizable models, the PSBC model does not require quantum-mechanical calculations of the peptide simulated at every time-step of the simulation and maintains the dynamic update of atomic charges, thereby reducing the computational cost and time while accounting for the polarization effect dynamically at the same time. The PSBC model is applied to two different β-peptides, namely the Beta3s/GS peptide, a de novo designed three-stranded β-sheet whose structure is folded in vitro and studied by NMR, and the trpzip peptides, a double-stranded β-sheet where a correlation is found between the type of amino acids that constitute the β-turn and the β-propensity.

Keywords: hydrogen bond, polarization effect, protein folding, PSBC

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431 Using the Micro Computed Tomography to Study the Corrosion Behavior of Magnesium Alloy at Different pH Values

Authors: Chia-Jung Chang, Sheng-Che Chen, Ming-Long Yeh, Chih-Wei Wang, Chih-Han Chang

Abstract:

Introduction and Motivation: In recent years, magnesium alloy is used to be a kind of medical biodegradable materials. Magnesium is an essential element in the body and is efficiently excreted by the kidneys. Furthermore, the mechanical properties of magnesium alloy is closest to human bone. However, in some cases magnesium alloy corrodes so quickly that it would release hydrogen on surface of implant. The other product is hydroxide ion, it can significantly increase the local pH value. The above situations may have adverse effects on local cell functions. On the other hand, nowadays magnesium alloy corrode too fast to maintain the function of implant until the healing of tissue. Therefore, much recent research about magnesium alloy has focused on controlling the corrosion rate. The in vitro corrosion behavior of magnesium alloys is affected by many factors, and pH value is one of factors. In this study, we will study on the influence of pH value on the corrosion behavior of magnesium alloy by the Micro-CT (micro computed tomography) and other instruments.Material and methods: In the first step, we make some guiding plates for specimens of magnesium alloy AZ91 by Rapid Prototyping. The guiding plates are able to be a standard for the degradation of specimen, so that we can use it to make sure the position of specimens in the CT image. We can also simplify the conditions of degradation by the guiding plates.In the next step, we prepare the solution with different pH value. And then we put the specimens into the solution to start the corrosion test. The CT image, surface photographs and weigh are measured on every twelve hours. Results: In the primary results of the test, we make sure that CT image can be a way to quantify the corrosion behavior of magnesium alloy. Moreover we can observe the phenomenon that corrosion always start from some erosion point. It’s possibly based on some defect like dislocations and the voids with high strain energy in the materials. We will deal with the raw data into Mass Loss (ML) and corrosion rate by CT image, surface photographs and weigh in the near future. Having a simple prediction, the pH value and degradation rate will be negatively correlated. And we want to find out the equation of the pH value and corrosion rate. We also have a simple test to simulate the change of the pH value in the local region. In this test the pH value will rise to 10 in a short time. Conclusion: As a biodegradable implant for the area with stagnating body fluid flow in the human body, magnesium alloy can cause the increase of local pH values and release the hydrogen. Those may damage the human cell. The purpose of this study is finding out the equation of the pH value and corrosion rate. After that we will try to find the ways to overcome the limitations of medical magnesium alloy.

Keywords: magnesium alloy, biodegradable materials, corrosion, micro-CT

Procedia PDF Downloads 457
430 Evaluation of the Cytotoxicity and Cellular Uptake of a Cyclodextrin-Based Drug Delivery System for Cancer Therapy

Authors: Caroline Mendes, Mary McNamara, Orla Howe

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Drug delivery systems are proposed for use in cancer treatment to specifically target cancer cells and deliver a therapeutic dose without affecting normal cells. For that purpose, the use of folate receptors (FR) can be considered a key strategy, since they are commonly over-expressed in cancer cells. In this study, cyclodextrins (CD) have being used as vehicles to target FR and deliver the chemotherapeutic drug, methotrexate (MTX). CDs have the ability to form inclusion complexes, in which molecules of suitable dimensions are included within their cavities. Here, β-CD has been modified using folic acid so as to specifically target the FR. Thus, this drug delivery system consists of β-CD, folic acid and MTX (CDEnFA:MTX). Cellular uptake of folic acid is mediated with high affinity by folate receptors while the cellular uptake of antifolates, such as MTX, is mediated with high affinity by the reduced folate carriers (RFCs). This study addresses the gene (mRNA) and protein expression levels of FRs and RFCs in the cancer cell lines CaCo-2, SKOV-3, HeLa, MCF-7, A549 and the normal cell line BEAS-2B, quantified by real-time polymerase chain reaction (real-time PCR) and flow cytometry, respectively. From that, four cell lines with different levels of FRs, were chosen for cytotoxicity assays of MTX and CDEnFA:MTX using the MTT assay. Real-time PCR and flow cytometry data demonstrated that all cell lines ubiquitously express moderate levels of RFC. These experiments have also shown that levels of FR protein in CaCo-2 cells are high, while levels in SKOV-3, HeLa and MCF-7 cells are moderate. A549 and BEAS-2B cells express low levels of FR protein. FRs are highly expressed in all the cancer cell lines analysed when compared to the normal cell line BEAS-2B. The cell lines CaCo-2, MCF-7, A549 and BEAS-2B were used in the cell viability assays. 48 hours treatment with the free drug and the complex resulted in IC50 values of 93.9 µM ± 15.2 and 56.0 µM ± 4.0 for CaCo-2 for free MTX and CDEnFA:MTX respectively, 118.2 µM ± 16.8 and 97.8 µM ± 12.3 for MCF-7, 36.4 µM ± 6.9 and 75.0 µM ± 10.5 for A549 and 132.6 µM ± 16.1 and 288.1 µM ± 26.3 for BEAS-2B. These results demonstrate that free MTX is more toxic towards cell lines expressing low levels of FR, such as the BEAS-2B. More importantly, these results demonstrate that the inclusion complex CDEnFA:MTX showed greater cytotoxicity than the free drug towards the high FR expressing CaCo-2 cells, indicating that it has potential to target this receptor, enhancing the specificity and the efficiency of the drug. The use of cell imaging by confocal microscopy has allowed visualisation of FR targeting in cancer cells, as well as the identification of the interlisation pathway of the drug. Hence, the cellular uptake and internalisation process of this drug delivery system is being addressed.

Keywords: cancer treatment, cyclodextrins, drug delivery, folate receptors, reduced folate carriers

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429 Effect of Hypoxia on AOX2 Expression in Chlamydomonas reinhardtii

Authors: Maria Ostroukhova, Zhanneta Zalutskaya, Elena Ermilova

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The alternative oxidase (AOX) mediates cyanide-resistant respiration, which bypasses proton-pumping complexes III and IV of the cytochrome pathway to directly transfer electrons from reduced ubiquinone to molecular oxygen. In Chlamydomonas reinhardtii, AOX is a monomeric protein that is encoded by two genes of discrete subfamilies, AOX1 and AOX2. Although AOX has been proposed to play essential roles in stress tolerance of organisms, the role of subfamily AOX2 is largely unknown. In C. reinhardtii, AOX2 was initially identified as one of constitutively low expressed genes. Like other photosynthetic organisms C. reinhardtii cells frequently experience periods of hypoxia. To examine AOX2 transcriptional regulation and role of AOX2 in hypoxia adaptation, real-time PCR analysis and artificial microRNA method were employed. Two experimental approaches have been used to induce the anoxic conditions: dark-anaerobic and light-anaerobic conditions. C. reinhardtii cells exposed to the oxygen deprivation have shown increased AOX2 mRNA levels. By contrast, AOX1 was not an anoxia-responsive gene. In C. reinhardtii, a subset of genes is regulated by transcription factor CRR1 in anaerobic conditions. Notable, the AOX2 promoter region contains the potential motif for CRR1 binding. Therefore, the role of CRR1 in the control of AOX2 transcription was tested. The CRR1-underexpressing strains, that were generated and characterized in this work, exhibited low levels of AOX2 transcripts under anoxic conditions. However, the transformants still slightly induced AOX2 gene expression in the darkness. These confirmed our suggestions that darkness is a regulatory stimulus for AOX genes in C. reinhardtii. Thus, other factors must contribute to AOX2 promoter activity under dark-anoxic conditions. Moreover, knock-down of CRR1 caused a complete reduction of AOX2 expression under light-anoxic conditions. These results indicate that (1) CRR1 is required for AOX2 expression during hypoxia, and (2) AOX2 gene is regulated by CRR1 together with yet-unknown regulatory factor(s). In addition, the AOX2-underexpressing strains were generated. The analysis of amiRNA-AOX2 strains suggested a role of this alternative oxidase in hypoxia adaptation of the alga. In conclusion, the results reported here show that C. reinhardtii AOX2 gene is stress inducible. CRR1 transcriptional factor is involved in the regulation of the AOX2 gene expression in the absence of oxygen. Moreover, AOX2 but not AOX1 functions under oxygen deprivation. This work was supported by Russian Science Foundation (research grant № 16-14-10004).

Keywords: alternative oxidase 2, artificial microRNA approach, chlamydomonas reinhardtii, hypoxia

Procedia PDF Downloads 241
428 Natural Mexican Zeolite Modified with Iron to Remove Arsenic Ions from Water Sources

Authors: Maritza Estela Garay-Rodriguez, Mirella Gutierrez-Arzaluz, Miguel Torres-Rodriguez, Violeta Mugica-Alvarez

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Arsenic is an element present in the earth's crust and is dispersed in the environment through natural processes and some anthropogenic activities. Naturally released into the environment through the weathering and erosion of sulphides mineral, some activities such as mining, the use of pesticides or wood preservatives potentially increase the concentration of arsenic in air, water, and soil. The natural arsenic release of a geological material is a threat to the world's drinking water sources. In aqueous phase is found in inorganic form, as arsenate and arsenite mainly, the contamination of groundwater by salts of this element originates what is known as endemic regional hydroarsenicism. The International Agency for Research on Cancer (IARC) categorizes the inorganic As within group I, as a substance with proven carcinogenic action for humans. It has been found the presence of As in groundwater in several countries such as Argentina, Mexico, Bangladesh, Canada and the United States. Regarding the concentration of arsenic in drinking water according to the World Health Organization (WHO) and the Environmental Protection Agency (EPA) establish maximum concentrations of 10 μg L⁻¹. In Mexico, in some states as Hidalgo, Morelos and Michoacán concentrations of arsenic have been found in bodies of water around 1000 μg L⁻¹, a concentration that is well above what is allowed by Mexican regulations with the NOM-127- SSA1-1994 that establishes a limit of 25 μg L⁻¹. Given this problem in Mexico, this research proposes the use of a natural Mexican zeolite (clinoptilolite type) native to the district of Etla in the central valley region of Oaxaca, as an adsorbent for the removal of arsenic. The zeolite was subjected to a conditioning with iron oxide by the precipitation-impregnation method with 0.5 M iron nitrate solution, in order to increase the natural adsorption capacity of this material. The removal of arsenic was carried out in a column with a fixed bed of conditioned zeolite, since it combines the advantages of a conventional filter with those of a natural adsorbent medium, providing a continuous treatment, of low cost and relatively easy to operate, for its implementation in marginalized areas. The zeolite was characterized by XRD, SEM/EDS, and FTIR before and after the arsenic adsorption tests, the results showed that the modification methods used are adequate to prepare adsorbent materials since it does not modify its structure, the results showed that with a particle size of 1.18 mm, an initial concentration of As (V) ions of 1 ppm, a pH of 7 and at room temperature, a removal of 98.7% was obtained with an adsorption capacity of 260 μg As g⁻¹ zeolite. The results obtained indicated that the conditioned zeolite is favorable for the elimination of arsenate in water containing up to 1000 μg As L⁻¹ and could be suitable for removing arsenate from pits of water.

Keywords: adsorption, arsenic, iron conditioning, natural zeolite

Procedia PDF Downloads 172