Search results for: Claudia del C. Gutierrez Torres

Authors: N. Porzionato, M. Mantiñan, E. Bussi, S. Grinberg, R. Gutierrez, G. Curutchet

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This work sets out to debate the tensions involved in the processes of contamination and self-purification in the urban space, particularly in the streams that run through the Buenos Aires metropolitan area. For much of their course, those streams are piped; their waters do not come into contact with the outdoors until they have reached deeply impoverished urban areas with high levels of environmental contamination. These are peripheral zones that, until thirty years ago, were marshlands and fields. They are now densely populated areas largely lacking in urban infrastructure. The Cárcova neighborhood, where this project is underway, is in the José León Suárez section of General San Martín country, Buenos Aires province. A stretch of José León Suarez canal crosses the neighborhood. Starting upstream, this canal carries pollutants due to the sewage and industrial waste released into it. Further downstream, in the neighborhood, domestic drainage is poured into the stream. In this paper, we formulate a hypothesis diametrical to the one that holds that these neighborhoods are the primary source of contamination, suggesting instead that in the stretch of the canal that runs through the neighborhood the stream’s waters are actually cleaned and the sediments accumulate pollutants. Indeed, the stretches of water that runs through these neighborhoods act as water processing plants for the metropolis. This project has studied the different organic-load polluting contributions to the water in a certain stretch of the canal, the reduction of that load over the course of the canal, and the incorporation of pollutants into the sediments. We have found that the surface water has considerable ability to self-purify, mostly due to processes of sedimentation and adsorption. The polluting load is accumulated in the sediments where that load stabilizes slowly by means of anaerobic processes. In this study, we also investigated the risks of sediment management and the use of the processes studied here in controlled conditions as tools of environmental restoration.

Keywords: bioremediation, pollutants, sediments, urban streams

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Authors: Karla Sanchez-Ortiz, Yunuen Tapia-Torres, John Larsen, Felipe Garcia-Oliva

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Due to food demand production, the use of synthetic nitrogenous fertilizer has increased in agricultural soils to replace the N losses. Nevertheless, the intensive use of synthetic nitrogenous fertilizer in conventional agriculture negatively affects the soil and therefore the environment, so alternatives such as organic agriculture have been proposed for being more environmentally friendly. However, further research in soil is needed to see how agricultural management affects the dynamics of C and N. The objective of this research was to evaluate the C and N dynamics in the soil with three different agricultural management: an agricultural plot with intensive inorganic fertilization, a plot with semi-organic management and an agricultural plot with recent abandonment (2 years). For each plot, the soil C and N dynamics and the enzymatic activity of NAG and β-Glucosidase were characterized. Total C and N concentration of the plant biomass of each site was measured as well. Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) was higher in abandoned plot, as well as this plot had higher total carbon (TC) and total nitrogen (TN), besides microbial N and microbial C. While the enzymatic activity of NAG and β-Glucosidase was greater in the agricultural plot with inorganic fertilization, as well as nitrate (NO₃) was higher in fertilized plot, in comparison with the other two plots. The aboveground biomass (AB) of maize in the plot with inorganic fertilization presented higher TC and TN concentrations than the maize AB growing in the semiorganic plot, but the C:N ratio was highest in the grass AB in the abandoned plot. The C:N ration in the maize grain was greater in the semi-organic agricultural plot. These results show that the plot under intensive agricultural management favors the loss of soil organic matter and N, degrading the dynamics of soil organic compounds, promoting its fertility depletion.

Keywords: mineralization, nitrogen cycle, soil degradation, soil nutrients

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Authors: Barbara Torres Rives

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Uveitis. Non-infectious anterior uveitis is a polygenic inflammatory eye disease, and it is suggested that mediated processes by the immune system (autoimmune or not) are the main mechanisms proposed in the pathogenesis of this type of uveitis. A relationship between infectious processes, digestive disorders, and a dysbiosis of the microbiome was recently described. In addition, alterations in the immune response associated with the initiation and progression of the disease have been described. Objective: The aim of this study was to identify factors related to the immune system associated with complicated non-infectious anterior uveitis. Methods: A cross-sectional observational analytical study was carried out. The universe consisted of all patients attending the ocular inflammation service of the Cuban Institute of Ophthalmology Ramón Pando Ferrer. The sample consisted of 213 patients diagnosed with non-infectious anterior uveitis. Results: Of the 213 patients with non-infectious anterior uveitis, the development of ophthalmologic complications predominated 56.3% (p=0.0094). In patients with complications was more frequent the presence of human leukocyte antigen-B27 allele (49.2%) (p<0.0001), decreased immunoglobulin G (24.2%, p=0.0124), increased immunoglobulin A (14.2%, p=0.0024), history of recurrent sepsis (59.2%, p=0.0018), recurrent respiratory infections (44.2%, p=0.0003), digestive alterations (40%, p=0.0013) and spondyloarthropathies (30%, p=0.0314). By logistic regression, it was observed that, for each completed year, the elevated risk for developing complicated non-infectious anterior uveitis in human leukocyte antigen-B27 allele positive patients (OR: 4.22, p=0.000), Conclusions: The control of recurrent sepsis at mucosal level and immunomodulation could prevent complications in non-infectious anterior uveitis. Therefore, the microbiome becomes the target of treatment and prevention of complications in non-infectious anterior uveitis.

Keywords: non-infectious anterior uveitis, immune system disorders, recurrent mucosal infections, microbiome

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Authors: Afiq Mohd Fahmi, Tony Gutierrez, Sebastian Hennige

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Increasing amounts of CO₂ entering the marine environment, also known as ocean acidification, is documented as having harmful impacts on a variety of marine organisms. When considering the future risk of hydrocarbon pollution, which is generally detrimental to marine life as well, this needs to consider how OA-induced changes to microbial communities will compound this since hydrocarbon degradation is influenced by the community-level microbial response. This study aims to evaluate the effects of increased atmospheric CO₂ conditions and oil enrichment on the phytoplankton-associated bacterial communities. Faroe Shetland Channel (FSC) is a subarctic region in the northeast Atlantic where crude oil extraction has recently been expanded. In the event of a major oil spill in this region, it is vital that we understand the response of the bacterial community and its consequence on primary production within this region—some phytoplankton communities found in the ocean harbor hydrocarbon-degrading bacteria that are associated with its psychosphere. Surface water containing phytoplankton and bacteria from FSC were cultured in ambient and elevated atmospheric CO₂ conditions for 4 days of acclimation in microcosms before introducing 1% (v/v) of crude oil into the microcosms to simulate oil spill conditions at sea. It was found that elevated CO₂ conditions do not significantly affect the chl a concentration, and exposure to crude oil detrimentally affected chl a concentration up to 10 days after exposure to crude oil. The diversity and richness of the bacterial community were not significantly affected by both CO₂ treatment and oil enrichment. The increase in the relative abundance of known hydrocarbon degraders such as Oleispira, Marinobacter and Halomonas indicates potential for biodegradation of crude oil, while the resilience of dominant taxa Colwellia, unclassified Gammaproteobacteria, unclassified Rnodobacteria and unclassified Halomonadaceae could be associated with the recovery of microalgal community 13 days after oil exposure. Therefore, the microbial community from the subsurface of FSC has the potential to recover from crude oil pollution even under elevated CO₂ (750 ppm) conditions.

Keywords: phytoplankton, bacteria, crude oil, ocean acidification

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Authors: Ronald Villamar-Torres, Michael Staudt, Christopher Viot

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Cotton Gossypium hirsutum L. is one of the most important industrial crops, producing the world leading natural textile fiber, but is very prone to arthropod attacks that reduce crop yield and quality. Cotton cultivation, therefore, makes an outstanding use of chemical pesticides. In reaction to herbivorous arthropods, cotton plants nevertheless show natural defense reactions, in particular through volatile organic compounds (VOCs) emissions. These natural defense mechanisms are nowadays underutilized but have a very high potential for cotton cultivation, and elucidating their genetic bases will help to improve their use. Simulating herbivory attacks by mechanical wounding of cotton plants in greenhouse, we studied by qPCR the changes in gene expression for genes of the terpenoids biosynthesis pathway. Differentially expressed genes corresponded to higher levels of the terpenoids biosynthesis pathway and not to enzymes synthesizing particular terpenoids. The genes were mapped on the G. hirsutum L. reference genome; their global relationships inside the general metabolic pathways and the biosynthesis of secondary metabolites were visualized with iPath2. The chromatographic profiles of VOCs emissions indicated first monoterpenes and sesquiterpenes emissions, dominantly four molecules known to be involved in plant reactions to arthropod attacks. As a result, the study permitted to identify potential key genes for the emission of volatile terpenoids by cotton plants in reaction to an arthropod attack, opening possibilities for molecular-assisted cotton breeding in benefit of smallholder cotton growers.

Keywords: biosynthesis pathways, cotton, mechanisms of plant defense, terpenoids, volatile organic compounds

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Authors: Christobel Gondwe, Yongtao Lu, Claudia Mazzà, Xinshan Li

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Skeletal muscle plays an important role in the human body system and function by generating voluntary forces and facilitating body motion. However, The mechanical properties and behaviour of skeletal muscle are still not comprehensively known yet. As such, various robust engineering techniques have been applied to better elucidate the mechanical behaviour of skeletal muscle. It is considered that muscle mechanics are highly governed by the architecture of the fibre orientations. Therefore, the aim of this study was to investigate the effect of different fibre orientations on the mechanical behaviour of skeletal muscle.In this study, a continuum mechanics approach–finite element (FE) analysis was applied to the left bicep femoris long head to determine the contractile mechanism of the muscle using Hill’s three-element model. The geometry of the muscle was segmented from the magnetic resonance images. The muscle was modelled as a quasi-incompressible hyperelastic (Mooney-Rivlin) material. Two types of fibre orientations were implemented: one with the idealised fibre arrangement, i.e. parallel single-direction fibres going from the muscle origin to insertion sites, and the other with curved fibre arrangement which is aligned with the muscle shape.The second fibre arrangement was implemented through the finite element method; non-uniform rational B-spline (FEM-NURBs) technique by means of user material (UMAT) subroutines. The stress-strain behaviour of the muscle was investigated under idealised exercise conditions, and will be further analysed under physiological conditions. The results of the two different FE models have been outputted and qualitatively compared.

Keywords: FEM-NURBS, finite element analysis, Mooney-Rivlin hyperelastic, muscle architecture

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Authors: Edgar Mauricio Ruiz Osuna, Claudia Yaneth Herrera Bolivar, Sandra Liliana Gomez Vasquez

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The increasing needs of professionals with skills in software development in industry are incremental, therefore, the relevance of an educational process in line with the strengthening of these competencies, are part of the responsibilities of universities with careers related to the area of Informatics and Systems. In this sense, it is important to consider that in the National Science, Technology and Innovation Plan for the development of the Electronics, Information Technologies and Communications (2013) sectors, it is established as a weakness in the SWOT Analysis of the Software sector and Services, Deficiencies in training and professional training. Accordingly, UNIMINUTO's Computer Technology Program has addressed the analysis of students' performance in software development, identifying various problems such as dropout in programming subjects, academic averages, as well as deficiencies in strategies and competencies developed in the area of programming. As a result of this analysis, it was determined to design a collaborative learning platform in basic programming using heat maps as a tool to support didactic feedback. The pilot phase allows to evaluate in a programming course the ALGORINFO platform as a didactic resource, through an interactive and collaborative environment where students can develop basic programming practices and in turn, are fed back through the analysis of time patterns and difficulties frequent in certain segments or program cycles, by means of heat maps. The result allows the teacher to have tools to reinforce and advise critical points generated on the map, so that students and graduates improve their skills as software developers.

Keywords: collaborative platform, learning, feedback, programming, heat maps

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Authors: Claudia Cedeno Nadal, Mei-Ling Villafana, Griela Rodriguez, Jessica Martin, Jennifer Martin, Megan Patel

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This study systematically examines the impact of Transcendental Mindfulness Meditation on anxiety symptoms in young females aged 18-25. Through a comprehensive literature review, we found consistent evidence supporting the positive influence of Transcendental Mindfulness Meditation on reducing anxiety, enhancing overall well-being, and decreasing perceived stress levels within this demographic. The mechanisms underlying these effects include heightened self-awareness, improved emotional regulation, and the development of effective stress-coping strategies. These findings have significant implications for mental health interventions targeting young females. However, the reviewed studies had some limitations, such as small sample sizes and reliance on self-report measures. To advance this field, future research should focus on larger sample sizes and utilize a broader range of measurement methods, including neuroscience assessments. Additionally, investigating the temporal relationships between Transcendental Mindfulness Meditation, proposed mediators, and anxiety symptoms will help establish causal specificity and a deeper understanding of the precise mechanisms of action. The development of integrative models based on these mechanisms can further enhance the effectiveness of Transcendental Mindfulness Meditation as an intervention for anxiety in this demographic. This study contributes to the current knowledge on the potential benefits of Transcendental Mindfulness Meditation for reducing anxiety in young females, paving the way for more targeted and effective mental health interventions in this population.

Keywords: mindfulness, meditation, anxiety, transcendental mindfulness

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Authors: Estefania Ponce-Amaya, Ana Lidia Arellano-Ortiz, Cecilia Diaz-Hernandez, Jose Alberto Lopez-Diaz, Antonio De La Mora-Covarrubias, Claudia Lucia Vargas-Requena, Mauricio Salcedo-Vargas, Florinda Jimenez-Vega

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Cervical Cancer (CC) is the second leading cause of death among women worldwide and it had been associated with a persistent infection of human papillomavirus (HPV). The goal of the current study was to identify the prevalence of HPV infection in women with abnormal Pap smear who were attended at Dysplasia Clinic of Ciudad Juarez, Mexico. Methods: Cervical samples from 146 patients, who attended the Colposcopy Clinic at Sanitary Jurisdiction II of Cd Juarez, were collected for histopathology and molecular study. DNA was isolated for the HPV detection by Polymerase Chain Reaction (PCR) using MY09/011 and GP5/6 primers. The associated risk factors were assessed by a questionnaire. The statistical analysis was performed by ANOVA, using EpiINFO V7 software. Results: HPV infection was present in 142 patients (97.3 %). The prevalence of HPV infection was distributed in a 96% of all evaluated groups, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HISIL) and CC. We found a statistical significance (α = <0.05) between gestation and number of births as risk factors. The median values showed an ascending tend according with the lesion progression. However, CC showed a statistically significant difference with respect to the pre-carcinogenic stages. Conclusions: In these Mexican patients exists a high prevalence of HPV infection, and for that reason, we are studying the most prevalent HPV genotypes in this population.

Keywords: cervical cancer, HPV, prevalence hpv, squamous intraepithelial lesion

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Authors: Claudia Ehrentraut, Osama Ibrahim, Hercules Dalianis

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Policy making situations are real-world problems that exhibit complexity in that they are composed of many interrelated problems and issues. To be effective, policies must holistically address the complexity of the situation rather than propose solutions to single problems. Formulating and understanding the situation and its complex dynamics, therefore, is a key to finding holistic solutions. Analysis of text based information on the policy problem, using Natural Language Processing (NLP) and Text analysis techniques, can support modelling of public policy problem situations in a more objective way based on domain experts knowledge and scientific evidence. The objective behind this study is to support modelling of public policy problem situations, using text analysis of verbal descriptions of the problem. We propose a formal methodology for analysis of qualitative data from multiple information sources on a policy problem to construct a causal diagram of the problem. The analysis process aims at identifying key variables, linking them by cause-effect relationships and mapping that structure into a graphical representation that is adequate for designing action alternatives, i.e., policy options. This study describes the outline of an algorithm used to automate the initial step of a larger methodological approach, which is so far done manually. In this initial step, inferences about key variables and their interrelationships are extracted from textual data to support a better problem structuring. A small prototype for this step is also presented.

Keywords: public policy, problem structuring, qualitative analysis, natural language processing, algorithm, inference extraction

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Authors: Q. B. Maria de la Luz Ortega Juárez, Saúl Rojas Hernández, Itzel Berenice Rodríguez Mera, María Maricela Carrasco Yépez, Mara Gutierrez Sánchez

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Naegleria fowleri is a free-living amoeba found mainly in temperate freshwater and is the etiologic agent of primary amebic meningoencephalitis (PAM), a fatal acute disease with a mortality rate greater than 95%. At present, there are no treatments available for MAP, and the development of effective vaccines that generate long-term immunological memory allowing protection against MAP would be of great importance. The objective of this work was to analyze the effector and memory immune response in BALB/c mice immunized with total extract of N. fowleri co-administered with cholera toxin. In this study, BALB/c mice were immunized four times intranasally with ET of N. fowleri adjuvanted with CT with or without booster at three months and were challenged or not with the lethal dose of N. fowleri, determining survival, the humoral, effector and memory response, by ELISA and flow cytometry techniques. The results obtained showed that the survival of mice immunized with booster had 60% protection compared to the group without booster, which obtained 20% protection. Evaluating the humoral response, it was found that both IgG and IgA levels were higher in sera than in nasal washes in both treatments. In the cellular response, the increase in the percentage of positive cells was found for effector T and B lymphocytes in the nasal passages (NP) in the group with boost and nasopharynx-associated lymphoid tissue (NALT) in the group without boost and lymphocytes only. B in both treatments, as well as in memory cells treatment with boost T lymphocytes in PN and NALT and without boost in cervical lymph nodes (CG) with respect to B lymphocytes, in PN, GC and NALT in treatment with boost and NALT in treatment without booster. Therefore, the involvement of the effector immune response and memory play a fundamental role for protection against N. fowleri and for the development of vaccine candidates.

Keywords: immune response, immunological memory, naegleria fowleri, primary amebic meningoencephalitis

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Authors: Ana Sofia Torres Pereira

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Till this day, women have been underrepresented and stereotyped both in TV and Cinema Screens all around the World. While women have been gaining a different status and finding their own voice in the work place and in society, what we see on-screen is still something different, something gender biased, something that does not show the multifaceted identities a woman might have. But why is this so? Why are we stuck on this shallow vision of women on-screen? According to several cinema industry studies, most film screenwriters in Hollywood are men. Women actually represent a very low percentage of screenwriters. So why is this relevant? Could the underrepresentation of women screenwriters in Hollywood be affecting the way women are written, and as a result, are depicted in film? Films are about stories, about people, and if these stories are continuously told through a man’s gaze, is that helping in the creation of a gender imbalance towards women? On the other hand, one of the reasons given for the low percentage of women screenwriters is: women are said to be better at writing specific genres, like dramas and comedies, and not as good writing thrillers and action films, so, as women seem to be limited in the genres they can write, they are undervalued and underrepresented as screenwriters. It seems the gender bias and stereotype isn’t saved exclusively for women on-screen, but also off-screen and behind the screen. So film appears to be a men’s world, on and off-screen, and since men seem to write the majority of scripts, it might be no wonder that women have been written in a specific way and depicted in a specific way on-screen. Also, since films are a mass communication medium, maybe this over-sexualization and stereotyping on-screen is indoctrinating our society into believing this bias is alive and well, and thus targeting women off-screen as well (ergo, screenwriters). What about at the very begging of film? In the Silent Movies and Early Talkies era, women dominated the screenwriting industry. They wrote every genre, and the majority of scripts were written by women, not men. So what about then? How were women depicted in films then? Did women screenwriters, in an era that was still very harsh on women, use their stories and their power to break stereotypes and show women in a different light, or did they carry on with the stereotype, did they continue it and standardize it? This papers aims to understand how important it is to have more working women screenwriters in order to break stereotypes regarding the image of women on and off-screen. How much can a screenwriter (male or female) influence our gaze on women (on and off-screen)?

Keywords: cinema, gender bias, stereotype, women on-screen, women screenwriters

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Authors: Miguel A. Jimenez Barros, Elyn L. Solano Charris, Luis E. Ramirez, Lauren Castro Bolano, Carlos Torres Barreto, Juliana Morales Cubillo

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This project sought to mitigate the high levels of water consumption in industrial processes in accordance with the water-rationing plan promoted at national and international level due to the water consumption projections published by the United Nations. Water consumption has three main uses, municipal (common use), agricultural and industrial where the latter consumes a minimum percentage (around 20% of the total consumption). Awareness on world water scarcity, a Colombian company responsible for generation of massive consumption products, decided to implement politics and techniques for water treatment, recycling, and reuse. The project consisted in a business technology program that permits a better use of wastewater caused by production operations. This approach reduces the potable water consumption, generates better conditions of water in the sewage dumps, generates a positive environmental impact for the region, and is a reference model in national and international levels. In order to achieve the objective, a process flow diagram was used in order to define the industrial processes that required potable water. This strategy allowed the industry to determine a water reuse plan at the operational level without affecting the requirements associated with the manufacturing process and even more, to support the activities developed in administrative buildings. Afterwards, the company made an evaluation and selection of the chemical and biological processes required for water reuse, in compliance with the Colombian Law. The implementation of the business technology program optimized the water use and recirculation rate up to 70%, accomplishing an important reduction of the regional environmental impact.

Keywords: bio-reactor, potable water, reverse osmosis, water treatment

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Authors: Christine Ysabelle G. Roman, Pauline Torres

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Background: Hypertrophic cardiomyopathy is a disease of marked heterogeneity. It is a genetically determined heart disease characterized by significant myocardium hypertrophy that results in diastolic dysfunction, left ventricular outflow tract obstruction, and an increased risk of arrhythmias. The primary treatment in patients with such conditions is negative inotropic drugs, such as beta-blockers, calcium channel antagonists, and disopyramide. However, for those who remain symptomatic and need septal reduction therapy, surgical septal myectomy or alcohol septal ablation are options. Case Summary: A 19 – year old female presented in the authors’ institution with easy fatigability. The consult was done a year prior, and 2D echocardiography was requested which showed concentric left ventricular hypertrophy, asymmetrically hypertrophied interventricular septum (IVS) with the largest diameter of 3.3cm & subaortic dynamic obstruction with a maximum gradient of 47 mmHg. A repeat echo a year later showed asymmetric septal hypertrophy (IVS measuring at 3cm) with the systolic anterior motion of anterior mitral valve leaflet and left ventricular outflow tract obstruction (peak gradient of 50mmHg). The patient then underwent alcohol septal ablation and was discharged stable after four days of admission. Conclusion: Hypertrophic obstructive cardiomyopathy, a cardiovascular genetic disease, results in various patterns of left ventricular hypertrophy and abnormality of mitral valve apparatus. The patient is managed medically initially. However, despite optimal drug therapy and significant left ventricular outflow tract obstruction, significant heart failure symptoms or syncope require invasive treatment.

Keywords: hypertrophic obstructive cardiomyopathy, left ventricular outflow tract obstruction, alcohol septal ablation, alcohol

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Authors: M. Torres, A. Moulay, M. Zhuldybina, M. Rozel, N. D. Trinh, C. Bois

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Printed electronics are a fast-growing market as their applications cover a large range of industrial needs, their production cost is low, and the additive printing techniques consume less materials than subtractive manufacturing methods used in traditional electronics. With the growing demand for printed electronics, there are concerns about their harmful and irreversible contribution to the environment. Indeed, it is estimated that 80% of the environmental load of a product is determined by the choices made at the conception stage. Therefore, examination through a life cycle approach at the developing stage of a novel product is the best way to identify potential environmental issues and make proactive decisions. Life cycle analysis (LCA) is a comprehensive scientific method to assess the environmental impacts of a product in its different stages of life: extraction of raw materials, manufacture and distribution, use, and end-of-life. Impacts and major hotspots are identified and evaluated through a broad range of environmental impact categories of the ReCiPe (H) middle point method. At the conception stage, the LCA is a tool that provides an environmental point of view on the choice of materials and processes and weights-in on the balance between performance materials and eco-friendly materials. Using the life cycle approach, the current work aims to provide a cradle-to-grave life cycle assessment of a roll-to-roll hybrid printed smart label designed for the food cold chain. Furthermore, this presentation will present the environmental impact of metallic conductive inks, a comparison with promising conductive polymers, evaluation of energy vs. performance of industrial printing processes, a full assessment of the impact from the smart label applied on a cellulosic-based substrate during the recycling process and the possible recovery of precious metals and rare earth elements.

Keywords: Eco-design, label, life cycle assessment, printed electronics

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Authors: Astorga-Trejo Rebeca, Fonseca-Peralta Héctor Manuel, Beltrán-Arredondo Laura Ivonne, Castro-Martínez Claudia

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The use of biomass as feedstock for the production of fuels and other chemicals of interest is an ever-growing accepted option in the way to the development of biorefinery complexes; in the Mexican state of Sinaloa, two million tons of residues from corn crops are produced every year, most of which can be converted to bioethanol and other products through biotechnological conversion using yeast and other microorganisms. Therefore, the objective of this work was to take advantage of corn stover and evaluate its potential as a substrate for the production of second-generation bioethanol (2G), enzymes, and xylitol. To produce bioethanol 2G, an acid-alkaline pretreatment was carried out prior to saccharification and fermentation. The microorganisms used for the production of enzymes, as well as for the production of xylitol, were isolated and characterized in our workgroup. Statistical analysis was performed using Design Expert version 11.0. The results showed that it is possible to obtain 2G bioethanol employing corn stover as a carbon source and Saccharomyces cerevisiae ItVer01 and Candida intermedia CBE002 with yields of 0.42 g and 0.31 g, respectively. It was also shown that C. intermedia has the ability to produce xylitol with a good yield (0.46 g/g). On the other hand, qualitative and quantitative studies showed that the native strains of Fusarium equiseti (0.4 IU/mL - xylanase), Bacillus velezensis (1.2 IU/mL – xylanase and 0.4 UI/mL - amylase) and Penicillium funiculosum (1.5 IU / mL - cellulases) have the capacity to produce xylanases, amylases or cellulases using corn stover as raw material. This study allowed us to demonstrate that it is possible to use corn stover as a carbon source, a low-cost raw material with high availability in our country, to obtain bioproducts of industrial interest, using processes that are more environmentally friendly and sustainable. It is necessary to continue the optimization of each bioprocess.

Keywords: biomass, corn stover, biorefinery, bioethanol 2G, enzymes, xylitol

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Authors: C. Sánchez de Rojas Candela, A. Riquelme, P. Rodrigo, M. D. Escalera-Rodríguez, B. Torres, J. Rams

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Selective laser melting is one of the most commonly used AM techniques. In it, a thin layer of metallic powder is deposited, and a laser is used to melt selected zones. The accumulation of layers, each one molten in the preselected zones, gives rise to the formation of a 3D sample with a nearly arbitrary design. To ensure that the properties of the final parts match those of the powder, all the process is carried out in an inert atmosphere, preferentially Ar, although this gas could be substituted. Ti6Al4V alloy is widely used in multiple industrial applications such as aerospace, maritime transport and biomedical, due to its properties. However, due to the demanding requirements of these applications, greater hardness and wear resistance are necessary, together with a better machining capacity, which currently limits its commercialization. To improve these properties, in this study, Selective Laser Melting (SLM) is used to manufacture Ti/TiN metal matrix composites with in-situ and ex-situ titanium nitride reinforcement where the scanning speed is modified (from 28.5 up to 65 mm/s) to study the influence of the processing parameters in SLM. A one-step method of nitriding the Ti6Al4V alloy is carried out to create in-situ TiN reinforcement in a reactive atmosphere and it is compared with ex-situ composites manufactured by previous mixture of both the titanium alloy powder and the ceramic reinforcement particles. The microstructure and mechanical properties of the different Ti/TiN composite materials have been analyzed. As a result, the existence of a similar matrix has been confirmed in in-situ and ex-situ fabrications and the growth mechanisms of the nitrides have been studied. An increase in the mechanical properties with respect to the initial alloy has been observed in both cases and related to changes in their microstructure. Specifically, a greater improvement (around 30.65%) has been identified in those manufactured by the in-situ method at low speeds although other properties such as porosity must be improved for their future industrial applicability.

Keywords: in-situ reinforcement, nitriding reaction, selective laser melting, titanium nitride

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Authors: Andrew R. Beatty

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The exploitation of Australia’s vast mineral wealth is regulated by a matrix of planning, environment and heritage legislation, and despite the desire for a ‘balance’ between economic, environmental and heritage values, Aboriginal objects and places are often detrimentally impacted by mining approvals. The Australian experience is not novel. There are other cases of clashes between the rights of traditional landowners and businesses seeking to exploit mineral or other resources on or beneath those lands, including in the United States, Canada, and Brazil. How one reconciles the rights of traditional owners with those of resource companies is an ongoing legal problem of general interest. In Australia, planning and environmental approvals for resource projects are ordinarily issued by State or Territory governments. Federal legislation such as the Aboriginal and Torres Strait Islander Heritage Protection Act 1984 (Cth) is intended to act as a safety net when State or Territory legislation is incapable of protecting Indigenous objects or places in the context of approvals for resource projects. This paper will analyse the context and effectiveness of legislation enacted to protect Indigenous heritage in the planning process. In particular, the paper will analyse how the statutory objects of such legislation need to be weighed against the statutory objects of competing legislation designed to facilitate and control resource exploitation. Using a current claim in the Federal Court of Australia for the protection of a culturally significant landscape as a case study, this paper will examine the challenges faced in ascribing value to cultural heritage within the wider context of environmental and planning laws. Our findings will reveal that there is an inherent difficulty in defining and weighing competing economic, environmental and heritage considerations. An alternative framework will be proposed to guide regulators towards making decisions that result in better protection of Indigenous heritage in the context of resource management.

Keywords: environmental law, heritage law, indigenous rights, mining

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Authors: Cristina Gutiérrez Carranza

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Digital nomadism is a trend and lifestyle which combines work and traveling. This tourism tendency is motivated by the desire to have a fixed source of financial income while becoming independent from a specific work location. This study contextualizes Costa Rica and its potential prospects to take advantage of this tourism market niche. It explores the dynamics of digital nomadism in the context of Costa Rica, analyzing the current scenario, challenges, and opportunities related to this global phenomenon. The research covers several areas, including the conceptualization of digital nomadism, its historical background, and contemporary manifestations. The investigation delves into the present state of digital nomadism, evaluating the extent of digitalization in Costa Rica, mobile phone coverage, and fixed internet access. As part of the strategies implemented, as the study develops, mapping the most common destinations of digital nomads is a key factor, bringing a sight on the aspects that make Costa Rica an attractive location for this emerging tourist group. Additionally, the paper draws insights from hosting entrepreneurs and digital nomads with work visas in Costa Rica, offering a comprehensive understanding of the experiences and perspectives from both sides. Hence, the study includes data from a sample of 20 digital nomads holding visas for Costa Rica, offering a detailed analysis of their professional activities, experiences and needs as remote workers in the country. As well it adds in perceptions from 10 entrepreneurs engaged in providing accommodation services to digital nomads contribute to a degree of understanding of the way they have faced this growing movement. This research provides significant insights on the dynamics of digital nomadism in Costa Rica by integrating data from specific sources. Policymakers, entrepreneurs, and other stakeholders are anticipated to gain valuable data from the findings regarding the opportunities and challenges of hosting and accommodating digital nomads, which will ultimately aid in the creation of plans to capitalize on this worldwide trend for the nation's socioeconomic development.

Keywords: digital nomads, tourism, sustainability, digital nomads visa, remote jobs

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Authors: Luís Marques, João Rocha, Andreia Fernandes, Maria Moura, Cláudia Caseiro, Filipa Figueiredo, João Nunes

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The implementation of circularity strategies other than recycling, such as reducing the amount of raw material, as well as reusing or sharing existing products, remains marginal. The European Commission announced that the transition towards a more circular economy could lead to the net creation of about 700,000 jobs in Europe by 2030, through additional labour demand from recycling plants, repair services and other circular activities. Efforts to create new circular business models in accordance with completely circular processes, as opposed to linear ones, have increased considerably in recent years. In order to create a societal Circular Economy transition model, it is necessary to include innovative solutions, where startups play a key role. Early-stage startups based on new business models according to circular processes often face difficulties in creating enough impact. The StartUp Zero Program designs a model and approach to increase the flow of startups in the Circular Economy field, focusing on a systemic decision analysis and multi-generational approach, considering Multi-Criteria Decision Analysis to support a decision-making tool, which is also supported by the use of a combination of an Analytical Hierarchy Process and Multi-Attribute Value Theory methods. We define principles, criteria and indicators for evaluating startup prerogatives, quantifying the evaluation process in a unique result. Additionally, this entrepreneurship program spanning 16 months involved more than 2400 young people, from ages 14 to 23, in more than 200 interaction activities.

Keywords: circular economy, entrepreneurship, startups;, multi-criteria decision analysis

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Authors: Claudia Pimentel, Nuno Resende, Maria Fatima Lambert

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In the present time, catastrophe seems to be inevitable, and individuals are permanently overwhelmed with challenges that test one’s ability to cope with reality. Undoubtedly, photography surpassed the barrier of efficient communication in a world filled with omnifarious narratives. It wandered an outing shorter than words and younger than other sciences but became, nowadays, imperative in the context of several fields of knowledge, namely Heritage studies. Heritage and photography thus emerge as unapologetically related concepts, a fact that makes them equally relevant in today's society. Political, economic, social and humanitarian challenges alter the way in which the relationship with the past is managed and the way in which identities and ideas for the future are constructed. Ruins and destruction have become part of aesthetics discourse since the 18th century and are an area of interest when we discuss cultural heritage preservation. The image proves to be a unique way of revealing the event details when we refer to a catastrophic situation, whether it be anthropic, social or climatic. Like poetry, which has a challenging connection with silence, image is capable of creating spaces of sound and silence, and it is often these “pseudo-voids” that capture the attention of the spectator, of the one who sees/observes/contacts with the photography. The way we look at the catastrophe, how we describe it, and the images we keep in our memory will determine the record/capture/news of the event. We, thus, have a visual record, a document that will contribute to the creation of individual and collective identity, in a jigsaw puzzle of memories, pseudo memories and post memories. Based on photographic records in the Portuguese press, we intend to rethink the earthquake at Angra do Heroísmo – Azores in 1980, exploring the viewer´s perspective on the catastrophe’s iconography under the perspective of aesthetics and genealogy of the catastrophe.

Keywords: photography, aesthetics, catastrophe, Portugal

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Authors: Merly Patiño Villanueva, Dubys Villarreal Torres, Eduardo Salazar Araujo, Lezly Ramos Macedo

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The concept of sustainability has been influencing business thinking from the perspective of various economic sectors and their environment, looking for concerns related to the risks associated with the indiscriminate consumption of the planet's resources, which have been widely studied and exposed by different public and private organizations. Tourism is not outsider to this reality; therefore, the concept of sustainable tourism evolves towards the integral management of resources, attending the needs of tourists, host communities and service providers, protecting ecosystems and assuring the conservation of the environment and its biodiversity. Considering the above, the purpose of this paper is to identify trends aimed at promoting sustainable tourism in the destinations of Barranquilla (Colombia) and Nayarit (Mexico). This study is part of the realistic epistemological paradigm, based on the existence of a specific environment for the development of tourism activity and the best sustainability practices associated with this industry, which can be observed and studied, therefore, this research contemplates qualitative research techniques such as the focus group and the interview, applied to 8 experts who are part of the value chain of the sector under study, added to a documentary review taken from the scientific databases Wos and Scopus, as well as statistical information published by official bodies. The data obtained were processed with the qualitative analysis software N-VIVO version 13. As a result, trends and actions to promote tourism are identified for the positioning of the cities of Barranquilla (Colombia) and Nayarit (Mexico) as sustainable destinations: first, the recovery of green areas and environmental spaces, as well as the realization of cultural events; promotion and encouragement of the creative industry and finally the realization of international events. It is concluded that both cities develop activities, projects and investments of public initiative, aimed at positioning them as sustainable tourist destinations.

Keywords: marketing, sustainability, tourism management, policies

Procedia PDF Downloads 74

Authors: Mario J. Meco-Gutierrez, Francisco Perez-Hidalgo, Juan R. Heredia-Larrubia, Antonio Ruiz-Gonzalez, Francisco Vargas-Merino

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More and more applications power inverters connected to transformers, for example, the connection facilities to the power grid renewable generation. It is well known that the quality of signal power inverters it is not a pure sine. The harmonic content produced negative effects, one of which is the heating of electrical machines and therefore, affects the life of the machines. The decrease of life of transformers can be calculated by Arrhenius or Montsinger equation. Analyzing this expression any (long-term) decrease of a transformer temperature for 6º C - 7º C means doubles its life-expectancy. Methodologies: This work presents the technique of pulse width modulation (PWM) with an injection of harmonic and triangular frequency carrier modulated in frequency. This technique is used to improve the quality of the output voltage signal of the power inverters controlled PWM. The proposed technique increases in the fundamental term and a significant reduction in low order harmonics with the same commutations per time that control sine PWM. To achieve this, the modulating wave is compared to a triangular carrier with variable frequency over the period of the modulator. Therefore, it is, advantageous for the modulating signal to have a large amount of sinusoidal “information” in the areas of greater sampling. A triangular signal with a frequency that varies over the modulator’s period is used as a carrier, for obtaining more samples in the area with the greatest slope. A power inverter controlled by PWM proposed technique is connected to a transformer. Results: In order to verify the derived thermal parameters under different operation conditions, another ambient and loading scenario is involved for a further verification, which was sampled from the same power transformer. Temperatures of different parts of the transformer will be exposed for each PWM control technique analyzed. An assessment of the temperature be done with different techniques PWM control and hence the life of the transformer is calculated for each technique. Conclusion: This paper analyzes such as transformer heating produced by this technique and compared with other forms of PWM control. In it can be seen as a reduction the harmonic content produces less heat transformer and therefore, an increase in the life of the transformer.

Keywords: heating, power-inverter, PWM, transformer

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Authors: Claudia Seabra, Elisabeth Kastenholz, José Luís Abrantes, Manuel Reis

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In a world of increasing mobility and global risks, terrorism has, in a perverse way, capitalized on contemporaneous society’s growing interest in travel to explore a world whose national boundaries and distances have decreased. Terrorists have identified the modern tourist flows originated from the economically more developed countries as new appealing targets so as to: i) call attention to the causes they defend and ii) destroy a country’s foundations of tourism, with the final aim of disrupting the economic and consequently social fabric of the affected countries. The present study analyses sensitivity towards risk and travel behaviors in international travel amongst a sample of 600 international tourists from 49 countries travelling by air. Specifically, the sample was segmented according to the Global Peace Index. This index defines country profiles regarding the levels of peace. The indicators used are established over three broad themes: i) ongoing domestic and international conflict; ii) societal safety and security; and iii) militarisation. Tourists were segmented, according to their country of origin, in different levels of peacefulness. Several facets of travel behavior were evaluated, namely motivations, attitude towards trip planning, quality perception and perceived value of the trip. Also factors related with risk perception were evaluated, specifically terrorism risk perception during the trip, unsafety sensation as well as importance attributed to safety in travel. Results contribute to our understanding of the role of previous exposure to the lack of peace and safety at home in the international tourists behaviors, which is further discussed in terms of tourism management and marketing implications which should particularly interest tourism services and destinations more affected by terrorism, war, political turmoil, crime and other safety risks.

Keywords: terrorism, tourism, safety, risk perception

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Authors: Ali Etemadi, Claudia Fernanda Yasar

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Elevated water storage tank structures (EWSTs) are high elevated-ponderous structural systems and very vulnerable to seismic vibrations. In past earthquake events, many of these structures exhibit poor performance and experienced severe damage. The dynamic analysis of the EWSTs under earthquake loads is, therefore, of significant importance for the design of the structure and a key issue for the development of modern methods, such as active control design. In this study, a reduced model of the EWSTs is explained, which is based on a tuned mass damper model (TMD). Vibration analysis of a structure under seismic excitation is presented and then used to propose an active vibration controller. MATLAB/Simulink is employed for dynamic analysis of the system and control of the seismic response. A single degree of freedom (SDOF) and two degree of freedom (2DOF) models of ELSTs are going to be used to study the concept of active vibration control. Lab-scale experimental models similar to pendulum are applied to suppress vibrations in ELST under seismic excitation. One of the most important phenomena in liquid storage tanks is the oscillation of fluid due to the movements of the tank body because of its base motions during an earthquake. Simulation results illustrate that the EWSTs vibration can be reduced by means of an input shaping technique that takes into account the dominant mode shape of the structure. Simulations with which to guide many of our designs are presented in detail. A simple and effective real-time control for seismic vibration damping can be, therefore, design and built-in practice.

Keywords: elevated water storage tank, tuned mass damper model, real time control, shaping control, seismic vibration control, the laplace transform

Procedia PDF Downloads 132

Authors: Maria Lopez-Ibarra, Ana Velazquez-Wong, Lucelli Yañez-Gutierrez, Maria Araujo-Solis, Fabio Salamanca-Gomez, Alfonso Mendez-Tenorio, Haydeé Rosas-Vargas

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Congenital heart diseases (CHD) are the most common congenital abnormalities. These conditions can occur as both an element of distinct chromosomal malformation syndromes or as non-syndromic forms. Their etiology is not fully understood. Genetic variants such copy number variants have been associated with CHD. The aim of our study was to analyze these genomic variants in peripheral blood from Mexican children diagnosed with non-syndromic CHD. We included 16 children with atrial and ventricular septal defects and 5 healthy subjects without heart malformations as controls. To exclude the most common heart disease-associated syndrome alteration, we performed a fluorescence in situ hybridization test to identify the 22q11.2, responsible for congenital heart abnormalities associated with Di-George Syndrome. Then, a microarray based comparative genomic hybridization was used to identify global copy number variants. The identification of copy number variants resulted from the comparison and analysis between our results and data from main genetic variation databases. We identified copy number variants gain in three chromosomes regions from pediatric patients, 4q13.2 (31.25%), 9q34.3 (25%) and 20q13.33 (50%), where several genes associated with cellular, biosynthetic, and metabolic processes are located, UGT2B15, UGT2B17, SNAPC4, SDCCAG3, PMPCA, INPP6E, C9orf163, NOTCH1, C20orf166, and SLCO4A1. In addition, after a hierarchical cluster analysis based on the fluorescence intensity ratios from the comparative genomic hybridization, two congenital heart disease groups were generated corresponding to children with atrial or ventricular septal defects. Further analysis with a larger sample size is needed to corroborate these copy number variants as possible biomarkers to differentiate between heart abnormalities. Interestingly, the 20q13.33 gain was present in 50% of children with these CHD which could suggest that alterations in both coding and non-coding elements within this chromosomal region may play an important role in distinct heart conditions.

Keywords: aCGH, bioinformatics, congenital heart diseases, copy number variants, fluorescence in situ hybridization

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Authors: Ana Claudia Muniz Rennó, Karina Nogueira

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This study aimed to investigate the in vivo tissue response of the introduction of the bioactive mesh (BM) scaffolds using a model of tibial bone defect implants in rats. Although a previous in vivo study demonstrated a highly positive response of particulate bioactive materials in the morphological and biomechanical properties of the bone callus, the effects of material with superior bioactivity, present in form of meshes have not been studied yet. Eighty male Wistar rats with 3 mm tibial defects were used. Animals were divided into four groups: intact group (IG) – tibia without any injury; bone defect day zero (0dD) – bone defects, sacrificed immediately after injury; bone defect control group (CG) – bone defects without any filler and bone defect filled with BM scaffold. The animals of BM and CG groups were sacrificed 15, 30 and 45 days post-injury to compare the temporal-special effects of the scaffolds on bone healing. The histological analysis revealed an organized newly formed bone at 30 and 45 days post-surgery in the BM. Also, this group presented an increased COX-2 expression on days 15 and 30 post-surgery. Furthermore, the immunohistochemistry analysis revealed that, BM presented a positive immunoexpression of RUNX-2 during all periods evaluated. The biomechanical analysis revealed that at 15 day after surgery, no significant statistically difference was observed between BM and CG and both groups had significantly higher values of maximal load compared to 0dG and significantly lower values than IG. On days 30 and 45 post-surgery, BM presented statistically lower values of maximal load compared to the CG. Nevertheless, at the same periods, BM did not show statistically significant difference compared to the IG maximal load values (p > 0, 05). Our results revealed that the implantation of the BM scaffolds was effective in stimulating newly bone formation.

Keywords: bone, biomaterials, scaffolds, cartilage

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Authors: Claudia Koby, Merav Boaz, Meirav Zaiger Kober

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Krembo Wings is an all-inclusive youth movement which brings children and youth with any disability together with their able-bodied peers (counselors) for weekly fun and educational social activities. Krembo Wings utilizes a socio-educational framework to create and lead social change through members with and without disabilities. All the work that Krembo Wings engages in stems from its central goal of promoting inclusion and integration using social and psychological theories to develop its unique model and approach. The key to Krembo Wings' approach in promoting inclusion is active participation – each member, with and without disabilities, is enabled to participate to their fullest capacity in the youth movement and its activities. In order for this to be achieved, all activities are adjustable and are modified to fit the abilities of each member. Additionally, youth counselors – most of whom are members without disabilities – go through extensive training in order to act as 'intermediaries' for their partner with disabilities, enabling and facilitating their partner's participation in a way that allows them to be as independent and active as possible. The relationship is one of friendship and not of caretaking. There is always a nurse on-hand to tend to any caretaking needs. Two essential elements of Krembo Wings' model is the broadening of concepts – shifting and changing the understanding of certain concepts such as what it means to be 'independent' or 'able' – and the development of a unique language – creating a language which both reflects and shapes reality. These elements of Krembo Wings' model foster the development of the values of acceptance and appreciation of those who are 'different'. It instills in members and counselors a new way of perceiving the world, one in which inclusion and integration are achievable and natural. Krembo Wings is certain that implementation of this model will promote the participation and inclusion of individuals with disabilities in society while promoting diversity. This model can serve as a platform which can be replicated and adjusted to suit any environment.

Keywords: innovative model for inclusion, socio-educational movement, youth leadership, youth with and without disabilities

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Authors: Claudia Matassa, Matthias Hohne, Dominic Ormerod, Yamini Satyawali

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Chiral amines integrate the backbone of several active pharmaceutical ingredients (APIs) used in modern medicine for the treatment of a vast range of diseases. Despite the demand, their synthesis remains challenging. Besides a range of chemicals and enzymatical methods, chiral amine synthesis using transaminases (EC 2.6.1.W) represents a useful alternative to access this important class of compounds. Even though transaminases exhibit excellent stereo and regioselectivity and the potential for high yield, the reaction suffers from a number of challenges, including the thermodynamic equilibrium, product inhibition, and low substrate solubility. In this work, we demonstrate a membrane assisted strategy for addressing these challenges. It involves the use of high molecular weight (HMW) amine donors for the transaminase-catalyzed synthesis of 4-phenyl-2-butylamine in both aqueous and organic solvent media. In contrast to common amine donors such as alanine or isopropylamine, these large molecules, provided in excess for thermodynamic equilibrium shifting, are easily retained by commercial nanofiltration membranes; thus a selective permeation of the desired smaller product amine is possible. The enzymatic transamination in aqueous media, combined with selective product removal shifted the equilibrium enhancing substrate conversion by an additional 25% compared to the control reaction. Along with very efficient amine product removal, there was undesirable loss of ketone substrate and low product concentration was achieved. The system was therefore further improved by performing the reaction in organic solvent (n-heptane). Coupling the reaction system with membrane-assisted product removal resulted in a highly concentrated and relatively pure ( > 97%) product solution. Moreover, a product yield of 60% was reached, compared to 15% without product removal.

Keywords: amine donor, chiral amines, in situ product removal, transamination

Procedia PDF Downloads 123

Authors: Debora C. Mendes, Matthias Eckert, Claudia S. Moço, Helio Martins, Jean-Pierre Gonçalves, Miguel Oliveira, Jose P. Da Silva

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Disposal of construction and demolition waste (C&DW) in embankments in the periphery of cities causes both environmental and social problems. To achieve the management of C&DW, a detailed analysis of the properties of these materials should be done. In this work we report a comparative study of the physical, chemical and environmental properties of natural and C&DW aggregates from 25 different origins. Assays were performed according to European Standards. Analysis of heavy metals and organic compounds, namely polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were performed. Finally, properties of concrete prepared with C&DW aggregates are reported. Physical analyses of C&DW aggregates indicated lower quality properties than natural aggregates, particularly for concrete preparation and unbound layers of road pavements. Chemical properties showed that most samples (80%) meet the values required by European regulations for concrete and unbound layers of road pavements. Analyses of heavy metals Cd, Cr, Cu, Pb, Ni, Mo and Zn in the C&DW leachates showed levels below the limits established by the Council Decision of 19 December 2002. Identification and quantification of PCBs and PAHs indicated that few samples shows the presence of these compounds. The measured levels of PCBs and PAHs are also below the limits. Other compounds identified in the C&DW leachates include phthalates and diphenylmethanol. The characterized C&DW aggregates show lower quality properties than natural aggregates but most samples showed to be environmentally safe. A continuous monitoring of the presence of heavy metals and organic compounds should be made to trial safe C&DW aggregates. C&DW aggregates provide a good economic and environmental alternative to natural aggregates.

Keywords: concrete preparation, construction and demolition waste, heavy metals, organic pollutants

Procedia PDF Downloads 333