Search results for: Jean François Maniriho
108 A Study of Police Culture Themes Towards the Public Among South African Police Service
Authors: Nkosingiphile M. Mbhele, Jean Steyn
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A focus group discussion was implemented, which comprised of senior South African Police Service managers and police academics in South Africa. The measurement of solidarity, isolation, and cynicism among functional South African Police Service officials and a thirty-item questionnaire came about by reviewing the literature. This research uses a survey format to assess the police culture theme of solidarity, isolation, and cynicism among South African Police Service officers in 9 South African provinces. Although a survey format is used in research, it engages in a quasi-experimental pre-test/post-test repeated measures research (longitudinal) design. Although there are differences among South African Police Service police (SAPS) officers, overall, there are signs of solidarity, isolation, and cynicism among SAPS members. Attitudes of solidarity, isolation, and cynicism are present among most police officials and have been presented from the start of training and held, maintained, or strengthened for the next years of their SAPS careers. This issue is problematic to society with regard to community-orientated policing since they have to interact with the members of the community. To author’s best knowledge, longitudinal studies of police culture are rare to find; not much has been researched on this topic. However, this paper offers to bridge that gap by providing answers to longitudinal police attitudes towards the public within the police culture themes of isolation and cynicism attitudes.Keywords: South African police service, police culture, solidarity, isolation, cynicism, public
Procedia PDF Downloads 151107 Determination of Elasticity Constants of Isotropic Thin Films Using Impulse Excitation Technique
Authors: M. F. Slim, A. Alhussein, F. Sanchette, M. François
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Thin films are widely used in various applications to enhance the surface properties and characteristics of materials. They are used in many domains such as: biomedical, automotive, aeronautics, military, electronics and energy. Depending on the elaboration technique, the elastic behavior of thin films may be different from this of bulk materials. This dependence on the elaboration techniques and their parameters makes the control of the elasticity constants of coated components necessary. Our work is focused on the characterization of the elasticity constants of isotropic thin films by means of Impulse Excitation Techniques. The tests rely on the measurement of the sample resonance frequency before and after deposition. In this work, a finite element model was performed with ABAQUS software. This model was then compared with the analytical approaches used to determine the Young’s and shear moduli. The best model to determine the film Young’s modulus was identified and a relation allowing the determination of the shear modulus of thin films of any thickness was developed. In order to confirm the model experimentally, Tungsten films were deposited on glass substrates by DC magnetron sputtering of a 99.99% purity tungsten target. The choice of tungsten was done because it is well known that its elastic behavior at crystal scale is ideally isotropic. The macroscopic elasticity constants, Young’s and shear moduli and Poisson’s ratio of the deposited film were determined by means of Impulse Excitation Technique. The Young’s modulus obtained from IET was compared with measurements by the nano-indentation technique. We did not observe any significant difference and the value is in accordance with the one reported in the literature. This work presents a new methodology on the determination of the elasticity constants of thin films using Impulse Excitation Technique. A formulation allowing the determination of the shear modulus of a coating, whatever the thickness, was developed and used to determine the macroscopic elasticity constants of tungsten films. The developed model was validated numerically and experimentally.Keywords: characterization, coating, dynamical resonant method, Poisson's ratio, PVD, shear modulus, Young's modulus
Procedia PDF Downloads 363106 Information and Communication Technology Application in the Face of COVID-19 Pandemic in Effective Service Delivery in Schools
Authors: Odigie Veronica
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The paper focused on the application of Information and Communication Technology (ICT) in effective service delivery in view of the ongoing COVID-19 experience. It adopted the exploratory research method with three research objectives captured. Consequently, the objectives were to ascertain the meaning of online education, understand the concept of COVID-19 and to determine the relevance of online education in effective service delivery in institutions of learning. It is evident from the findings that through ICT, online mode of learning can be adopted in schools which helps greatly in promoting continual education. Online mode of education is practiced online; it brings both the teacher and learners from different places together, without any physical boundary/contact (at least 75%); and has helped greatly in human development in countries where it has been practiced. It is also a welcome development owing to its many benefits such as exposure to digital learning, having access to works of great teachers and educationists such as Socrates, Plato, Dewey, R.S. Peters, J. J. Rosseau, Nnamdi Azikwe, Carol Gilligan, J. I. Omoregbe, Jane Roland Martin, Jean Piaget, among others; and the facilitation of uninterrupted learning for class promotion and graduation of students. Developing the learners all round is part of human development which helps in developing a nation. These and many more are some benefits online education offers which make ICT very relevant in our contemporary societyKeywords: online education, COVID-19 pandemic, effective service delivery, human development
Procedia PDF Downloads 100105 Development of a New Characterization Method to Analyse Cypermethrin Penetration in Wood Material by Immunolabelling
Authors: Sandra Tapin-Lingua, Katia Ruel, Jean-Paul Joseleau, Daouia Messaoudi, Olivier Fahy, Michel Petit-Conil
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The preservative efficacy of organic biocides is strongly related to their capacity of penetration and retention within wood tissues. The specific detection of the pyrethroid insecticide is currently obtained after extraction followed by chemical analysis by chromatography techniques. However visualizing the insecticide molecule within the wood structure requires specific probes together with microscopy techniques. Therefore, the aim of the present work was to apply a new methodology based on antibody-antigen recognition and electronic microscopy to visualize directly pyrethroids in the wood material. A polyclonal antibody directed against cypermethrin was developed and implement it on Pinus sylvestris wood samples coated with technical cypermethrin. The antibody was tested on impregnated wood and the specific recognition of the insecticide was visualized in transmission electron microscopy (TEM). The immunogold-TEM assay evidenced the capacity of the synthetic biocide to penetrate in the wood. The depth of penetration was measured on sections taken at increasing distances from the coated surface of the wood. Such results correlated with chemical analyzes carried out by GC-ECD after extraction. In addition, the immuno-TEM investigation allowed visualizing, for the first time at the ultrastructure scale of resolution, that cypermethrin was able to diffuse within the secondary wood cell walls.Keywords: cypermethrin, insecticide, wood penetration, wood retention, immuno-transmission electron microscopy, polyclonal antibody
Procedia PDF Downloads 413104 Combining Multiscale Patterns of Weather and Sea States into a Machine Learning Classifier for Mid-Term Prediction of Extreme Rainfall in North-Western Mediterranean Sea
Authors: Pinel Sebastien, Bourrin François, De Madron Du Rieu Xavier, Ludwig Wolfgang, Arnau Pedro
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Heavy precipitation constitutes a major meteorological threat in the western Mediterranean. Research has investigated the relationship between the states of the Mediterranean Sea and the atmosphere with the precipitation for short temporal windows. However, at a larger temporal scale, the precursor signals of heavy rainfall in the sea and atmosphere have drawn little attention. Moreover, despite ongoing improvements in numerical weather prediction, the medium-term forecasting of rainfall events remains a difficult task. Here, we aim to investigate the influence of early-spring environmental parameters on the following autumnal heavy precipitations. Hence, we develop a machine learning model to predict extreme autumnal rainfall with a 6-month lead time over the Spanish Catalan coastal area, based on i) the sea pattern (main current-LPC and Sea Surface Temperature-SST) at the mesoscale scale, ii) 4 European weather teleconnection patterns (NAO, WeMo, SCAND, MO) at synoptic scale, and iii) the hydrological regime of the main local river (Rhône River). The accuracy of the developed model classifier is evaluated via statistical analysis based on classification accuracy, logarithmic and confusion matrix by comparing with rainfall estimates from rain gauges and satellite observations (CHIRPS-2.0). Sensitivity tests are carried out by changing the model configuration, such as sea SST, sea LPC, river regime, and synoptic atmosphere configuration. The sensitivity analysis suggests a negligible influence from the hydrological regime, unlike SST, LPC, and specific teleconnection weather patterns. At last, this study illustrates how public datasets can be integrated into a machine learning model for heavy rainfall prediction and can interest local policies for management purposes.Keywords: extreme hazards, sensitivity analysis, heavy rainfall, machine learning, sea-atmosphere modeling, precipitation forecasting
Procedia PDF Downloads 135103 Planning Quality and Maintenance Activities in a Closed-Loop Serial Multi-Stage Manufacturing System under Constant Degradation
Authors: Amauri Josafat Gomez Aguilar, Jean Pierre Kenné
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This research presents the development of a self-sustainable manufacturing system from a circular economy perspective, structured by a multi-stage serial production system consisting of a series of machines under deterioration in charge of producing a single product and a reverse remanufacturing system constituted by the same productive systems of the first scheme and different tooling, fed by-products collected at the end of their life cycle, and non-conforming elements of the first productive scheme. Since the advanced production manufacturing system is unable to satisfy the customer's quality expectations completely, we propose the development of a mixed integer linear mathematical model focused on the optimal search and assignment of quality stations and preventive maintenance operation to the machines over a time horizon, intending to segregate the correct number of non-conforming parts for reuse in the remanufacturing system and thereby minimizing production, quality, maintenance, and customer non-conformance penalties. Numerical experiments are performed to analyze the solutions found by the model under different scenarios. The results showed that the correct implementation of a closed manufacturing system and allocation of quality inspection and preventive maintenance operations generate better levels of customer satisfaction and an efficient manufacturing system.Keywords: closed loop, mixed integer linear programming, preventive maintenance, quality inspection
Procedia PDF Downloads 85102 Numerical Simulation of Lifeboat Launching Using Overset Meshing
Authors: Alok Khaware, Vinay Kumar Gupta, Jean Noel Pederzani
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Lifeboat launching from marine vessel or offshore platform is one of the important areas of research in offshore applications. With the advancement of computational fluid dynamic simulation (CFD) technology to solve fluid induced motions coupled with Six Degree of Freedom (6DOF), rigid body dynamics solver, it is now possible to predict the motion of the lifeboat precisely in different challenging conditions. Traditionally dynamic remeshing approach is used to solve this kind of problems, but remeshing approach has some bottlenecks to control good quality mesh in transient moving mesh cases. In the present study, an overset method with higher-order interpolation is used to simulate a lifeboat launched from an offshore platform into calm water, and volume of fluid (VOF) method is used to track free surface. Overset mesh consists of a set of overlapping component meshes, which allows complex geometries to be meshed with lesser effort. Good quality mesh with local refinement is generated at the beginning of the simulation and stay unchanged throughout the simulation. Overset mesh accuracy depends on the precise interpolation technique; the present study includes a robust and accurate least square interpolation method and results obtained with overset mesh shows good agreement with experiment.Keywords: computational fluid dynamics, free surface flow, lifeboat launching, overset mesh, volume of fluid
Procedia PDF Downloads 277101 Risk Factors for Severe Typhoid Fever in Children: A French Retrospective Study about 78 Cases from 2000-2017 in Six Parisian Hospitals
Authors: Jonathan Soliman, Thomas Cavasino, Virginie Pommelet, Lahouari Amor, Pierre Mornand, Simon Escoda, Nina Droz, Soraya Matczak, Julie Toubiana, François Angoulvant, Etienne Carbonnelle, Albert Faye, Loic de Pontual, Luu-Ly Pham
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Background: Typhoid and paratyphoid fever are systemic infections caused by Salmonella enterica serovar Typhi or paratyphi (A, B, C). Children traveling to tropical areas are at risk to contract these diseases which can be complicated. Methods: Clinical, biological and bacteriological data were collected from 78 pediatric cases reported between 2000 and 2017 in six Parisian hospitals. Children aged 0 to 18 years old, with a diagnosis of typhoid or paratyphoid fever confirmed by bacteriological exams, were included. Epidemiologic, clinical, biological features and presence of multidrug-resistant (MDR) bacteria or intermediate susceptibility to ciprofloxacin (nalidixic acid resistant) were examined by univariate analysis and by logistic regression analysis to identify risk factors of severe typhoid in children. Results: 84,6% of the children were imported cases of typhoid fever (n=66/78) and 15,4% were autochthonous cases (n=12/78). 89,7% were caused by S.typhi (n=70/78) and 12,8% by S.paratyphi (n=10/78) including 2 co-infections. 19,2% were intrafamilial cases (n=15/78). Median age at diagnosis was 6,4 years-old [6 months-17,9 years]. 28,2% of the cases were complicated forms (n=22/78): digestive (n=8; 10,3%), neurological (n=7; 9%), pulmonary complications (n=4; 5,1%) and hemophagocytic syndrome (n=4; 5,1%). Only 5% of the children had prior immunization with typhoid non-conjugated vaccine (n=4/78). 28% of the cases (n=22/78) were caused by resistant bacteria. Thrombocytopenia and diagnosis delay was significantly associated with severe infection (p= 0.029 and p=0,01). Complicated forms were more common with MDR (p=0,1) and not statistically associated with a young age or sex in this study. Conclusions: Typhoid and paratyphoid fever are not rare in children back from tropical areas. This multicentric pediatric study seems to show that thrombocytopenia, diagnosis delay, and multidrug resistant bacteria are associated with severe typhoid fever and complicated forms in children.Keywords: antimicrobial resistance, children, Salmonella enterica typhi and paratyphi, severe typhoid
Procedia PDF Downloads 181100 Propeller Performance Modeling through a Computational Fluid Dynamics Analysis Method
Authors: Maxime Alex Junior Kuitche, Ruxandra Mihaela Botez, Jean-Chirstophe Maunand
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The evolution of aircraft is closely linked to the study and improvement of propulsion systems. Determining the propulsion performance is a real challenge in aircraft modeling and design. In addition to theoretical methodologies, experimental procedures are used to obtain a good estimation of the propulsion performances. For piston-propeller propulsion, the propeller needs several experimental tests which could be extremely demanding in terms of time and money. This paper presents a new procedure to estimate the performance of a propeller from a numerical approach using computational fluid dynamic analysis. The propeller was initially scanned, and then, its 3D model was represented using CATIA. A structured meshing and Shear Stress Transition k-ω turbulence model were applied to describe accurately the flow pattern around the propeller. Thus, the Partial Differential Equations were solved using ANSYS FLUENT software. The method was applied on the UAS-S45’s propeller designed and manufactured by Hydra Technologies in Mexico. An extensive investigation was performed for several flight conditions in terms of altitudes and airspeeds with the aim to determine thrust coefficients, power coefficients and efficiency of the propeller. The Computational Fluid Dynamics results were compared with experimental data acquired from wind tunnel tests performed at the LARCASE Price-Paidoussis wind tunnel. The results of this comparison have demonstrated that our approach was highly accurate.Keywords: CFD analysis, propeller performance, unmanned aerial system propeller, UAS-S45
Procedia PDF Downloads 35399 The Neutrophil-to-Lymphocyte Ratio after Surgery for Hip Fracture in a New, Simple, and Objective Score to Predict Postoperative Mortality
Authors: Philippe Dillien, Patrice Forget, Harald Engel, Olivier Cornu, Marc De Kock, Jean Cyr Yombi
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Introduction: Hip fracture precedes commonly death in elderly people. Identification of high-risk patients may contribute to target patients in whom optimal management, resource allocation and trials efficiency is needed. The aim of this study is to construct a predictive score of mortality after hip fracture on the basis of the objective prognostic factors available: Neutrophil-to-lymphocyte ratio (NLR), age, and sex. C-Reactive Protein (CRP), is also considered as an alternative to the NLR. Patients and methods: After the IRB approval, we analyzed our prospective database including 286 consecutive patients with hip fracture. A score was constructed combining age (1 point per decade above 74 years), sex (1 point for males), and NLR at postoperative day+5 (1 point if >5). A receiver-operating curve (ROC) curve analysis was performed. Results: From the 286 patients included, 235 were analyzed (72 males and 163 females, 30.6%/69.4%), with a median age of 84 (range: 65 to 102) years, mean NLR values of 6.47+/-6.07. At one year, 82/280 patients died (29.3%). Graphical analysis and log-rank test confirm a highly statistically significant difference (P<0.001). Performance analysis shows an AUC of 0.72 [95%CI 0.65-0.79]. CRP shows no advantage on NLR. Conclusion: We have developed a score based on age, sex and the NLR to predict the risk of mortality at one year in elderly patients after surgery for a hip fracture. After external validation, it may be included in clinical practice as in clinical research to stratify the risk of postoperative mortality.Keywords: neutrophil-to-lymphocyte ratio, hip fracture, postoperative mortality, medical and health sciences
Procedia PDF Downloads 41298 A Case Study on the Census of Technological Capacities in Health Care in Rural Sanitary Institutions in South Cameroon
Authors: Doriane Micaela Andeme Bikoro, Samuel Fosso Wamba, Jean Robert Kala Kamdjoug
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Currently one of the leading fields in the market of technological innovation is digital health. In developed countries, this booming innovation is experiencing an exponential speed. We understand that in developed countries, e-health could also revolutionize the practice of medicine and therefore fill the many failures observed in medical care. Everything leads to believe that future technology is oriented towards the medical sector. The aim of this work is to explore at the same time the technological resources and the potential of health care based on new technologies; it is a case study in a rural area of Southern Cameroon. Among other things, we will make a census of the shortcomings and problems encountered, and we will propose various appropriate solutions. The work methodology used here is essentially qualitative. We used two qualitative data collection techniques, direct observation, and interviews. In fact, we spent two weeks in the field observing and conducting some semi-directive interviews with some of those responsible for these health structures. This study was conducted in three health facilities in the south of the country; including two health centers and a rural hospital. Many technological failures have been identified in the day-to-day management of these health facilities and especially in the administration of health care to patients. We note major problems such as the digital divide, the lack of qualified personnel, the state of isolation of this area. This is why various proposals are made to improve the health sector in Cameroon both technologically and medically.Keywords: Cameroon, capacities, census, digital health, qualitative method, rural area
Procedia PDF Downloads 14497 A Caged Bird Set Free: The Women Saviors in Fae Myenne Ng's Steer Toward Rock
Authors: Hei Yuen Pak
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Steer Toward Rock, Fae Myenne Ng’s second novel after the National Bestseller Bone, is superficially concluded as a story of pessimism, which underestimates the sophistication of Ng’s portrayal. It is often summarized as a “heartbreaking novel of unrequited love” or “a story of timeless and tragic”; yet, Ng’s novel conveys more than a mere sense of tragedy and heartbreak, but rather an overflowing warmth and optimism. Ng is complimented of “illuminating a part of U.S. history few are aware of”—the false identity established on the paper relationships. Nevertheless, toward the end of the novel, this falsity enlightens the male protagonist, Jack Moon Szeto, of the ultimate realization of the “truthfulness” to himself, with the escort of the female characters. This paper intends to investigate how Ng’s depiction subverts the traditional sex/gender system and also the patriarchal savior stereotype. This paper mainly examines the characterization of and the relations among the four major characters: Jack Moon Szeto, Joice Qwan, Veda Qwan, and Ilin Cheung. By deploying Kate Millett’s, Marilyn French’s, Mary Daly’s feminist theories, the first half of the essay elucidates the power relations between Jack and the three females Joice, Veda, and Ilin in terms of gender and sexuality. After analyzing the relations, Jack, this male caged bird, is set free by the epiphany derived from the three female characters, which is the pivot of the second half. In reference to Jean-Paul Sartre and Simone de Beauvoir’s existentialist perspectives, I argue how Jack is transformed from, in Satre’s term, being-for-others to being-for-itself. Hence, the caged bird is free by the women saviors.Keywords: Fae Myenne Ng, gender and sexuality, feminism, power relations
Procedia PDF Downloads 57096 Hidden Populations and Women: New Political, Methodological and Ethical Challenges
Authors: Renée Fregosi
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The contribution presently proposed will report on the beginnings of a Franco-Chilean study to be launched in 2015 by a multidisciplinary team of Renée Fregosi Political Science University Paris 3 / CECIEC, Norma Muñoz Public Policies University of Santiago of Chile, Jean-Daniel Lelievre, Medicine Paris 11 University, Marcelo WOLFF Medicine University of Chile, Cecilia Blatrix Political Science University Paris-Tech, Ernesto OTTONE, Political Science University of Chile, Paul DENY Medicine Paris 13 University, Rafael Bugueno Medicine Hospital Urgencia Pública of Santiago, Eduardo CARRASCO Political Science Paris 3 University. The problem of hidden populations challenges some criteria and concepts to re-examine: in particular the concept of target population, sampling methods to "snowball" and the cost-effectiveness criterion that shows the connection of political and scientific fields. Furthermore, if the pattern of homosexual transmission still makes up the highest percentage of the modes of infection with HIV, there is a continuous increase in the number of people infected through heterosexual sex, including women and persons aged 50 years and older. This group can be described as " unknown risk people." Access to these populations is a major challenge and raises methodological, ethical and political issues of prevention, particularly on the issue of screening. This paper proposes an inventory of these types of problems and their articulation, to define a new phase in the prevention against HIV refocused on women.Keywords: HIV testing, hidden populations, difficult to reach PLWHA, women, unknown risk people
Procedia PDF Downloads 52295 Investigating Homicide Offender Typologies Based on Their Clinical Histories and Crime Scene Behaviour Patterns
Authors: Valeria Abreu Minero, Edward Barker, Hannah Dickson, Francois Husson, Sandra Flynn, Jennifer Shaw
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Purpose – The purpose of this paper is to identify offender typologies based on aspects of the offenders’ psychopathology and their associations with crime scene behaviours using data derived from the National Confidential Enquiry into Suicide and Safety in Mental Health concerning homicides in England and Wales committed by offenders in contact with mental health services in the year preceding the offence (n=759). Design/methodology/approach – The authors used multiple correspondence analysis to investigate the interrelationships between the variables and hierarchical agglomerative clustering to identify offender typologies. Variables describing: the offender’s mental health history; the offenders’ mental state at the time of offence; characteristics useful for police investigations; and patterns of crime scene behaviours were included. Findings – Results showed differences in the offender’s histories in relation to their crime scene behaviours. Further, analyses revealed three homicide typologies: externalising, psychosis and depression. Analyses revealed three homicide typologies: externalising, psychotic and depressive. Practical implications – These typologies may assist the police during homicide investigations by: furthering their understanding of the crime or likely suspect; offering insights into crime patterns; provide advice as to what an offender’s offence behaviour might signify about his/her mental health background; findings suggest information concerning offender psychopathology may be useful for offender profiling purposes in cases of homicide offenders with schizophrenia, depression and comorbid diagnosis of personality disorder and alcohol/drug dependence. Originality/value – Empirical studies with an emphasis on offender profiling have almost exclusively focussed on the inference of offender demographic characteristics. This study provides a first step in the exploration of offender psychopathology and its integration to the multivariate analysis of offence information for the purposes of investigative profiling of homicide by identifying the dominant patterns of mental illness within homicidal behaviour.Keywords: offender profiling, mental illness, psychopathology, multivariate analysis, homicide, crime scene analysis, crime scene behviours, investigative advice
Procedia PDF Downloads 12994 In the Eyes of Basilyo at Crispin: A Phenomenological Lived Experience of the Filipino Children of Parents with Mental Illness
Authors: Cely D. Magpantay, Geolynne Marie Adel, Cire-rine Mae Concepcion, Dessa Jean Orcajada, Jorgette Andrea Santos, Orian Laurace Canaman
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Mental illness initiative is very relevant in promoting the Mental Health Bill act of 2017. In the Philippines alone, the public is more open and receptive to people at risks with a mental condition. Although it is uncommon that parents can become more psychologically unfit compared to their children, research shows that parents who are suffering from mental illness have a more significant negative effect than another family member. The impact of parent’s mental health can put their children more susceptible to acquire the same disorder. The aim of the study is to explore the lived experiences of children whose parents suffered from mental illness. It discusses how their parent's mental condition in, anyway, affects their psychological development. Using Phenomenological Qualitative Research, an in-depth, interview was conducted to five (5) consenting adults who lived with their parents diagnosed with a mental disorder. Results are clustered into four themes. The first theme is the negative emotion towards parents, the second theme is the psychosocial dynamics in caring for the patient, third is accepting the disease, and fourth is a general perspective on the family. Each themes is validated by experts and the participants. This theme generates subcomponent like isolation, shallow relationship and debt of gratitude. Along with these themes comes the fear of having a family emerged. There is a growing need to strengthen the family ties even more because of parent’s mental illness. Therefore, parental mental illness has an effect on the children’s psychological and social development.Keywords: lived experience in Philippines, mental health, parental mental illness, psychosocial dynamics
Procedia PDF Downloads 31593 A New Multi-Target, Multi-Agent Search and Rescue Path Planning Approach
Authors: Jean Berger, Nassirou Lo, Martin Noel
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Perfectly suited for natural or man-made emergency and disaster management situations such as flood, earthquakes, tornadoes, or tsunami, multi-target search path planning for a team of rescue agents is known to be computationally hard, and most techniques developed so far come short to successfully estimate optimality gap. A novel mixed-integer linear programming (MIP) formulation is proposed to optimally solve the multi-target multi-agent discrete search and rescue (SAR) path planning problem. Aimed at maximizing cumulative probability of successful target detection, it captures anticipated feedback information associated with possible observation outcomes resulting from projected path execution, while modeling agent discrete actions over all possible moving directions. Problem modeling further takes advantage of network representation to encompass decision variables, expedite compact constraint specification, and lead to substantial problem-solving speed-up. The proposed MIP approach uses CPLEX optimization machinery, efficiently computing near-optimal solutions for practical size problems, while giving a robust upper bound obtained from Lagrangean integrality constraint relaxation. Should eventually a target be positively detected during plan execution, a new problem instance would simply be reformulated from the current state, and then solved over the next decision cycle. A computational experiment shows the feasibility and the value of the proposed approach.Keywords: search path planning, search and rescue, multi-agent, mixed-integer linear programming, optimization
Procedia PDF Downloads 37192 Improving Vocabulary and Listening Comprehension via Watching French Films without Subtitles: Positive Results
Authors: Yelena Mazour-Matusevich, Jean-Robert Ancheta
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This study is based on more than fifteen years of experience of teaching a foreign language, in my case French, to the English-speaking students. It represents a qualitative research on foreign language learners’ reaction and their gains in terms of vocabulary and listening comprehension through repeatedly viewing foreign feature films with the original sountrack but without English subtitles. The initial idea emerged upon realization that the first challenge faced by my students when they find themselves in a francophone environment has been their lack of listening comprehension. Their inability to understand colloquial speech affects not only their academic performance, but their psychological health as well. To remedy this problem, I have designed and applied for many years my own teaching method based on one particular French film, exceptionally suited, for the reasons described in detail in the paper, for the intermediate-advanced level foreign language learners. This project, conducted together with my undergraduate assistant and mentoree J-R Ancheta, aims at showing how the paralinguistic features, such as characters’ facial expressions, settings, music, historical background, images provided before the actual viewing, etc., offer crucial support and enhance students’ listening comprehension. The study, based on students’ interviews, also offers special pedagogical techniques, such as ‘anticipatory’ vocabulary lists and exercises, drills, quizzes and composition topics that have proven to boost students’ performance. For this study, only the listening proficiency and vocabulary gains of the interviewed participants were assessed.Keywords: comprehension, film, listening, subtitles, vocabulary
Procedia PDF Downloads 62591 Obesity, Leptin Levels and Leptin Receptor Gene Polymorphisms in Afro-Caribbean Subjects
Authors: Lydia Foucan, Christine Rambhojan, Rachel Billy, Christophe Armand, Carl-Thony Michel, Jean-Marc Lacorte, Laurent Larifla
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Leptin, an adipocyte-derived hormone, modulates insulin secretion and action via the leptin receptor (LEPR) that is expressed in pancreatic beta cells, adipose tissue, and muscle. Several polymorphisms have been described in the human LEPR gene including p.K109R (rs1137100), p.Q223R (rs1137101) and p.K656N (rs1805094) polymorphisms. The role of these polymorphisms is not yet studied in Guadeloupian population. Our aim was to explore the association of LEPR polymorphisms (K109R, Q223R and K656N) with leptin levels and obesity in non-diabetic Afro-Caribbean subjects. Genotypic analysis of the three polymorphisms was performed in 425 subjects using TaqMan and KASPar Assays. Serum leptin was measured with ELISA kits Biovendor® (RD191001100). Logistic regressions were used for assessment of statistical associations. Mean age was 47.6 ± 12.7 years. Among the participants, 238 (56 %) were women, 124 (30%) were obese and 155 (36.5%) had abdominal obesity. Carriers of LEPR K656N rs1805094 rare allele had significant higher frequencies of obesity (P = 0.007), abdominal obesity (P = 0.004) and metabolic syndrome (P = 0.021) but mean leptin level was not significantly different between both groups (P = 0.075). Odds ratios, adjusted for age and sex associated with presence of rs1805094 rare allele were 1.8 (1.1-2.9), P = 0.012 for obesity, 2.0 (1.2-3.3), P = 0.008 for abdominal obesity and 1.8 (1.1-3.0), P = 0.031 for MetS. No significant association was found with K109R, Q223R. These findings suggest that the K656N polymorphism (but not the K109R or Q223R polymorphism) of LEPR is associated with obesity, abdominal obesity and metabolic syndrome in this Afro-Caribbean non-diabetic population.Keywords: Afro-Caribbean, leptin levels, leptin receptor gene polymorphisms, obesity
Procedia PDF Downloads 37790 Liquid Chromatography Microfluidics for Detection and Quantification of Urine Albumin Using Linear Regression Method
Authors: Patricia B. Cruz, Catrina Jean G. Valenzuela, Analyn N. Yumang
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Nearly a hundred per million of the Filipino population is diagnosed with Chronic Kidney Disease (CKD). The early stage of CKD has no symptoms and can only be discovered once the patient undergoes urinalysis. Over the years, different methods were discovered and used for the quantification of the urinary albumin such as the immunochemical assays where most of these methods require large machinery that has a high cost in maintenance and resources, and a dipstick test which is yet to be proven and is still debated as a reliable method in detecting early stages of microalbuminuria. This research study involves the use of the liquid chromatography concept in microfluidic instruments with biosensor as a means of separation and detection respectively, and linear regression to quantify human urinary albumin. The researchers’ main objective was to create a miniature system that quantifies and detect patients’ urinary albumin while reducing the amount of volume used per five test samples. For this study, 30 urine samples of unknown albumin concentrations were tested using VITROS Analyzer and the microfluidic system for comparison. Based on the data shared by both methods, the actual vs. predicted regression were able to create a positive linear relationship with an R2 of 0.9995 and a linear equation of y = 1.09x + 0.07, indicating that the predicted values and actual values are approximately equal. Furthermore, the microfluidic instrument uses 75% less in total volume – sample and reagents combined, compared to the VITROS Analyzer per five test samples.Keywords: Chronic Kidney Disease, Linear Regression, Microfluidics, Urinary Albumin
Procedia PDF Downloads 13689 Impact of Different Rearing Diets on the Performance of Adult Mealworms Tenebrio molitor
Authors: Caroline Provost, Francois Dumont
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Production of insects for human and animal consumption is an increasingly important activity in Canada. Protein production is more efficient and less harmful to the environment using insect rearing compared to the impact of traditional livestock, poultry and fish farms. Insects are rich in essential amino acids, essential fatty acids and trace elements. Thus, insect-based products could be used as a food supplement for livestock and domestic animals and may even find their way into the diets of high performing athletes or fine dining. Nevertheless, several parameters remain to be determined to ensure efficient and profitable production that meet the potential of these sectors. This project proposes to improve the production processes, rearing diets and processing methods for three species with valuable gastronomic and nutritional potential: the common mealworms (Tenebrio molitor), the small mealworm (Alphitobius diaperinus), and the giant mealworm (Zophobas morio). The general objective of the project is to acquire specific knowledge for mass rearing of insects dedicated to animal and human consumption in order to respond to current market opportunities and meet a growing demand for these products. Mass rearing of the three species of mealworm was produced to provide the individuals needed for the experiments. Mealworms eat flour from different cereals (e.g. wheat, barley, buckwheat). These cereals vary in their composition (protein, carbohydrates, fiber, vitamins, antioxidant, etc.), but also in their purchase cost. Seven different diets were compared to optimize the yield of the rearing. Diets were composed of cereal flour (e.g. wheat, barley) and were either mixed or left alone. Female fecundity, larvae mortality and growing curves were observed. Some flour diets have positive effects on female fecundity and larvae performance while each mealworm was found to have specific diet requirements. Trade-offs between mealworm performance and costs need to be considered. Experiments on the effect of flour composition on several parameters related to performance and nutritional and gastronomic value led to the identification of a more appropriate diet for each mealworm.Keywords: mass rearing, mealworm, human consumption, diet
Procedia PDF Downloads 14788 An Analysis of Emmanuel Macron's Campaign Discourse
Authors: Robin Turner
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In the context of the strengthening conservative movements such as “Brexit” and the election of US President Donald Trump, the global political stage was shaken up by the election of Emmanuel Macron to the French presidency, defeating the far-right candidate Marine Le Pen. The election itself was a first for the Fifth Republic in which neither final candidate was from the traditional two major political parties: the left Parti Socialiste (PS) and the right Les Républicains (LR). Macron, who served as the Minister of Finance under his predecessor, founded the centrist liberal political party En Marche! in April 2016 before resigning from his post in August to launch his bid for the presidency. Between the time of the party’s creation to the first round of elections a year later, Emmanuel Macron and En Marche! had garnered enough support to make it to the run-off election, finishing far ahead of many seasoned national political figures. Now months into his presidency, the youngest President of the Republic shows no sign of losing fuel anytime soon. His unprecedented success raises a lot of questions with respect to international relations, economics, and the evolving relationship between the French government and its citizens. The effectiveness of Macron’s campaign, of course, relies on many factors, one of which is his manner of communicating his platform to French voters. Using data from oral discourse and primary material from Macron and En Marche! in sources such as party publications and Twitter, the study categorizes linguistic instruments – address, lexicon, tone, register, and syntax – to identify prevailing patterns of speech and communication. The linguistic analysis in this project is two-fold. In addition to these findings’ stand-alone value, these discourse patterns are contextualized by comparable discourse of other 2017 presidential candidates with high emphasis on that of Marine Le Pen. Secondly, to provide an alternative approach, the study contextualizes Macron’s discourse using those of two immediate predecessors representing the traditional stronghold political parties, François Hollande (PS) and Nicolas Sarkozy (LR). These comparative methods produce an analysis that gives insight to not only a contributing factor to Macron’s successful 2017 campaign but also provides insight into how Macron’s platform presents itself differently to previous presidential platforms. Furthermore, this study extends analysis to supply data that contributes to a wider analysis of the defeat of “traditional” French political parties by the “start-up” movement En Marche!.Keywords: Emmanuel Macron, French, discourse analysis, political discourse
Procedia PDF Downloads 26187 Bond Strength of Different Strengthening Systems: Concrete Elements under Freeze–Thaw Cycles and Salt Water Immersion Exposure
Authors: Firas Al-Mahmoud, Jean-Michel Mechling, Mohamed Shaban
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The long-term durability of fibre reinforced polymer (FRP) composites is often stated as being the main reason for the use of these materials. Indeed, structures externally or Near Surface Mounted (NSM) reinforced with Carbon Fibre Reinforcement Polymer CFRP are often in contact with temperature cycles and salt water immersion and other environmental conditions that reduce the expected durability of the system. Bond degradation is a frequent cause of premature failure of structural elements and environmental conditions are known to relate to such failures. The purpose of this study is to investigate the effect of environmental exposure on the bond for different CFRP strengthening systems. Bending tests were conducted to evaluate the bond with and without environmental exposure. The specimens were strengthened with CFRP sheets, CFRP plates and NSM CFRP rods embedded in two filling materials: epoxy resin and mortar. Then, they were exposed to up to 300 freeze–thaw cycles. One freeze–thaw cycle consisted of four stages according to ASTM or immersed in 3.5% salted tap water. A total of thirty-six specimens were prepared for this purpose. Results showed a decrease in ultimate bond strength for specimens strengthened by CFRP sheets that were immersed in salt water for 120 days, while a reduction was shown for CFRP sheet and plate bonded specimens that were subjected to 300 freeze–thaw cycles. Exposing NSM CFRP rod strengthened specimens, embedded in resin or mortar, to freeze–thaw cycles or to immersion in salt water does not affect the bond strength.Keywords: durability, strengthening, FRP, bond, freeze–thaw
Procedia PDF Downloads 35086 Deep Injection Wells for Flood Prevention and Groundwater Management
Authors: Mohammad R. Jafari, Francois G. Bernardeau
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With its arid climate, Qatar experiences low annual rainfall, intense storms, and high evaporation rates. However, the fast-paced rate of infrastructure development in the capital city of Doha has led to recurring instances of surface water flooding as well as rising groundwater levels. Public Work Authority (PWA/ASHGHAL) has implemented an approach to collect and discharge the flood water into a) positive gravity systems; b) Emergency Flooding Area (EFA) – Evaporation, Infiltration or Storage off-site using tankers; and c) Discharge to deep injection wells. As part of the flood prevention scheme, 21 deep injection wells have been constructed to discharge the collected surface and groundwater table in Doha city. These injection wells function as an alternative in localities that do not possess either positive gravity systems or downstream networks that can accommodate additional loads. These injection wells are 400-m deep and are constructed in a complex karstic subsurface condition with large cavities. The injection well system will discharge collected groundwater and storm surface runoff into the permeable Umm Er Radhuma Formation, which is an aquifer present throughout the Persian Gulf Region. The Umm Er Radhuma formation contains saline water that is not being used for water supply. The injection zone is separated by an impervious gypsum formation which acts as a barrier between upper and lower aquifer. State of the art drilling, grouting, and geophysical techniques have been implemented in construction of the wells to assure that the shallow aquifer would not be contaminated and impacted by injected water. Injection and pumping tests were performed to evaluate injection well functionality (injectability). The results of these tests indicated that majority of the wells can accept injection rate of 200 to 300 m3 /h (56 to 83 l/s) under gravity with average value of 250 m3 /h (70 l/s) compared to design value of 50 l/s. This paper presents design and construction process and issues associated with these injection wells, performing injection/pumping tests to determine capacity and effectiveness of the injection wells, the detailed design of collection system and conveying system into the injection wells, and the operation and maintenance process. This system is completed now and is under operation, and therefore, construction of injection wells is an effective option for flood control.Keywords: deep injection well, flood prevention scheme, geophysical tests, pumping and injection tests, wellhead assembly
Procedia PDF Downloads 11985 Numerical Simulation of Two-Phase Flows Using a Pressure-Based Solver
Authors: Lei Zhang, Jean-Michel Ghidaglia, Anela Kumbaro
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This work focuses on numerical simulation of two-phase flows based on the bi-fluid six-equation model widely used in many industrial areas, such as nuclear power plant safety analysis. A pressure-based numerical method is adopted in our studies due to the fact that in two-phase flows, it is common to have a large range of Mach numbers because of the mixture of liquid and gas, and density-based solvers experience stiffness problems as well as a loss of accuracy when approaching the low Mach number limit. This work extends the semi-implicit pressure solver in the nuclear component CUPID code, where the governing equations are solved on unstructured grids with co-located variables to accommodate complicated geometries. A conservative version of the solver is developed in order to capture exactly the shock in one-phase flows, and is extended to two-phase situations. An inter-facial pressure term is added to the bi-fluid model to make the system hyperbolic and to establish a well-posed mathematical problem that will allow us to obtain convergent solutions with refined meshes. The ability of the numerical method to treat phase appearance and disappearance as well as the behavior of the scheme at low Mach numbers will be demonstrated through several numerical results. Finally, inter-facial mass and heat transfer models are included to deal with situations when mass and energy transfer between phases is important, and associated industrial numerical benchmarks with tabulated EOS (equations of state) for fluids are performed.Keywords: two-phase flows, numerical simulation, bi-fluid model, unstructured grids, phase appearance and disappearance
Procedia PDF Downloads 39384 Evaluation of the Ability of COVID-19 Infected Sera to Induce Netosis Using an Ex-Vivo NETosis Monitoring Tool
Authors: Constant Gillot, Pauline Michaux, Julien Favresse, Jean-Michel Dogné, Jonathan Douxfils
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Introduction: NETosis has emerged as a crucial yet paradoxical factor in severe COVID-19 cases. While neutrophil extracellular traps (NETs) help contain and eliminate viral particles, excessive NET formation can lead to hyperinflammation, exacerbating tissue damage and acute respiratory distress syndrome (ARDS). Aims: This study evaluates the relationship between COVID-19-infected sera and NETosis using an ex-vivo model. Methods: Sera from 8 post-admission COVID-19 patients, after receiving corticoid therapy, were used to induce NETosis in neutrophils from a healthy donor. NET formation was tracked using fluorescent markers for DNA and neutrophil elastase (NE) every 2 minutes for 8 hours. The results were expressed as a percentage of DNA/NE released over time. Key metrics, including T50 (time to 50% release) and AUC (area under the curve), representing total NETosis potential), were calculated. A 27-cytokine screening kit was used to assess the cytokine composition of the sera. Results: COVID-19 sera induced NETosis based on their cytokine profile. The AUC of NE and DNA release decreased with time following corticoid therapy, showing a significant reduction in 6 of the 8 patients (p<0.05). T50 also decreased in parallel with AUC for both markers. Cytokines concentration decrease with time after therapy administration. There is correlation between 14 cytokines concentration and NE release. Conclusion: This ex-vivo model successfully demonstrated the induction of NETosis by COVID-19 sera using two markers. A clear decrease in NETosis potential was observed over time with glucocorticoid therapy. This model can be a valuable tool for monitoring NETosis and investigating potential NETosis inducers and inhibitors.Keywords: NETosis, COVID-19, cytokine storm, biomarkers
Procedia PDF Downloads 1983 Ilizarov's External Fixator. A Bone Regeneration Method Little Used in Africa. Our Experience of 20 Years in Cameroon.
Authors: Ibrahima Farikou, Kolontchang Gatchou Alberic Lionel, Tsiagadgui Jean Gustave, Ngo Yamben Marie-Ange, Handy Eone Daniel
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Introduction: It was in 1956 that Ilizarov pioneered the concept of osteogenesis in distraction by the device that bears his name to help produce bone and soft tissue regeneration and bone consolidation. This technique is not widely used in Africa where, however, its applications are numerous (loss of bone substances, congenital or acquired malformations). Our goal is to bring the indications of Ilizarov's device back to our practice conditions. Methods: Our study was conducted in 2 hospitals over a period of 20 years. For the retrospective phase, this study included all complete usable records of patients operated on in the Ilizarov external fixator department, and for the prospective phase, all patients operated on in the departments with complete usable records. Our sample was consecutive and not exhaustive. Data were analyzed by SPSS software version 23.0. Results: A total of 52 patients were reviewed. The average age of our patients was 14.7 years. The sex ratio was 1.6 in favor of men. The lower limb was the most affected (49), with a predominance of the tibia (62.4%). The average elongation was 6.4 cm. Traumatic acquired pathologies (delayed union, malunion) represented 60.6%. The mean time to union was seven months. Correction of the limb length discrepancy or filling of loss of bone substance was obtained in 75% of cases. Functionally, 80.8% of the patients treated had regained autonomy at the end of treatment, but in 17.3% of the patients, pain and limping persisted. Conclusion: This technique should be popularized in Africa because the benefit that would accrue to patients is invaluable and would be an attractive alternative to many amputations sometimes carried out in Africa by despair.Keywords: ilizarov, external fixator, limb lengthening, bone regeneration, africa
Procedia PDF Downloads 10182 Tokyo Skyscrapers: Technologically Advanced Structures in Seismic Areas
Authors: J. Szolomicki, H. Golasz-Szolomicka
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The architectural and structural analysis of selected high-rise buildings in Tokyo is presented in this paper. The capital of Japan is the most densely populated city in the world and moreover is located in one of the most active seismic zones. The combination of these factors has resulted in the creation of sophisticated designs and innovative engineering solutions, especially in the field of design and construction of high-rise buildings. The foreign architectural studios (as, for Jean Nouvel, Kohn Pedesen Associates, Skidmore, Owings & Merill) which specialize in the designing of skyscrapers, played a major role in the development of technological ideas and architectural forms for such extraordinary engineering structures. Among the projects completed by them, there are examples of high-rise buildings that set precedents for future development. An essential aspect which influences the design of high-rise buildings is the necessity to take into consideration their dynamic reaction to earthquakes and counteracting wind vortices. The need to control motions of these buildings, induced by the force coming from earthquakes and wind, led to the development of various methods and devices for dissipating energy which occur during such phenomena. Currently, Japan is a global leader in seismic technologies which safeguard seismic influence on high-rise structures. Due to these achievements the most modern skyscrapers in Tokyo are able to withstand earthquakes with a magnitude of over seven degrees at the Richter scale. Damping devices applied are of a passive, which do not require additional power supply or active one which suppresses the reaction with the input of extra energy. In recent years also hybrid dampers were used, with an additional active element to improve the efficiency of passive damping.Keywords: core structures, damping system, high-rise building, seismic zone
Procedia PDF Downloads 17581 Antibacterial Activity and Kinetic Parameters of the Essential Oils of Drypetes Gossweileri S.Moore, Ocimun Gratissimum L. and Cymbopogon Citratus DC Stapf on 5 Multidrug-Resistant Strains of Shigella
Authors: Elsa Makue Nguuffo, Esther Del Florence Moni Ndedi, Jacky Njiki Bikoï, Jean Paul Assam Assam, Maximilienne Ascension Nyegue
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Aims: The present study aims to evaluate the kinetic parameters of essential oils (EOs) and combinations fromDrypetes gossweileri Stem Bark, Ocimum gratissimum leaves, Cymbopogon citratusleaves after evaluation of their antibacterial activityonmultidrug-resistant strains ofShigella. Material and Methods:fiveclinical strains of Shigellaisolated from patients with diarrhoeaincluding Shigella flexneri, and 4 otherstrains of Shigella sppwere selected. Their antibiotic profile was established using agar test diffusion with seven antibiotics belonging to seven classes.EOs were extracted from each plant using hydrodistillation process. The activity of Ciprofloxacin®, OEs, and their combination formulatedinthe followingratios(w/w/w): C1: 1/1/1; C2: 2/1/1; C3: 1/2/1, C4:1/1/2 was evaluated microdilution assay. The various interactions of OEs in the different combinations were determined then the OE and the most active combination were retained to determine their kinetic parameters on S. flexneri. Results: Antibiotic susceptibility tests revealed that most Shigella isolates (n = 4) were resistant to six antibiotics tested. Ciprofloxacin (40%), Nalidixic acid (60%), Tetracycline (80%), Amoxicillin (100%), Cefotaxime (80%), Erythromycin (100%), and Cotrimoxazole (80%) were the profiles found in the different strains of Shigella. About the antibacterial activity of OEs, Drypetes gossweileriOE and C2 combination had shown a higher Shigellicide property with a Minimal Inhibitory Concentration(MIC) respectivelyranging from 0.078 mg/mL to 0.312 mg/mL and 0.012 to 1.562 mg/mL. Combinations of OEs showed various interactions whose synergistic effects were mostly encountered. The best deactivation was obtained by the combination C2 at 16 MIC withb= 1.962. Conclusion: the susceptibility of Shigella to OEs and their combinations justifies their use in traditional medicine in the treatment of shigellosis.Keywords: shigella, multidrug-resistant, EOs, kinetic
Procedia PDF Downloads 9880 Beyond Baudrillard: A Critical Intersection between Semiotics and Materialism
Authors: Francesco Piluso
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Nowadays, to restore the deconstructive power of semiotics implies a critical analysis of neoliberal ideology, and, even more critically, a confrontation with materialist perspective. The theoretical path of Jean Baudrillard is crucial to understand the ambivalence of this intersection. A semiotic critique of Baudrillard’s work, through tools of both structuralism and interpretative semiotics, has the aim to give materialism a new consistent semiotic approach and vice-versa. According to Baudrillard, the commodity form is characterized by the same abstract and systemic logic of the sign-form, in which the production of the signified (use-value) is a mere ideological mean for the reproduction of the signifiers-chain (exchange-value). Nevertheless, this parallelism is broken by the author himself: if the use-value is deconstructed in its relative logic, the signified and the referent, both as discrete and positive elements, are collapsed on the same plane at the shadows of the signified forms. These divergent considerations lead Baudrillard to the same crucial point: the dismissal of the material world, replaced by the hyperreality as reproduction of a semiotic (genetic) Code. The stress on the concept of form, as an epistemological and semiotic tool to analyse the construction of values in the consumer society, has led to the Code as its ontological drift. In other words, Baudrillard seems to enclose consumer society (and reality) in this immanent and self-fetishized world of signs–an ideological perspective that mystifies the gravity of the material relationships between Northern-Western World and Third World. The notion of Encyclopaedia by Umberto Eco is the key to overturn the relationship of immanence/transcendence between the Code and the economic political of the sign, by understanding the former as an ideological plane within the encyclopedia itself. Therefore, rather than building semiotic (hyper)realities, semiotics has to deal with materialism in terms of material relationships of power which are mystified and reproduced through such ideological ontologies of signs.Keywords: Baudrillard, Code, Eco, Encyclopaedia, epistemology vs. ontology, semiotics vs. materialism
Procedia PDF Downloads 16379 Linear and Nonlinear Resonance of Flat Bottom Hole in an Aluminum Plate
Authors: Biaou Jean-Baptiste Kouchoro, Anissa Meziane, Philippe Micheau, Mathieu Renier, Nicolas Quaegebeur
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Numerous experimental and numerical studies have shown the interest of the local defects resonance (LDR) for the Non-Destructive Testing of metallic and composite plates. Indeed, guided ultrasonic waves such as Lamb waves, which are increasingly used for the inspection of these flat structures, enable the generation of local resonance phenomena by their interaction with a damaged area, allowing the detection of defects. When subjected to a large amplitude motion, a nonlinear behavior can predominate in the damaged area. This work presents a 2D Finite Element Model of the local resonance of a 12 mm long and 5 mm deep Flat Bottom Hole (FBH) in a 6 mm thick aluminum plate under the excitation induced by an incident A0 Lamb mode. The analysis of the transient response of the FBH enables the precise determination of its resonance frequencies and the associate modal deformations. Then, a linear parametric study varying the geometrical properties of the FBH highlights the sensitivity of the resonance frequency with respect to the plate thickness. It is demonstrated that the resonance effect disappears when the ratio of thicknesses between the FBH and the plate is below 0.1. Finally, the nonlinear behavior of the FBH is considered and studied introducing geometrical (taken into account the nonlinear component of the strain tensor) nonlinearities that occur at large vibration amplitudes. Experimental analysis allows observation of the resonance effects and nonlinear response of the FBH. The differences between these experimental results and the numerical results will be commented on. The results of this study are promising and allow to consider more realistic defects such as delamination in composite materials.Keywords: guided waves, non-destructive testing, dynamic field testing, non-linear ultrasound/vibration
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