Search results for: biodegradable characteristics

Authors: Farrah Putri Salmanida, Mei-Li Wu, Rika Wahyuningtyas, Wen-Bin Chung, Hso-Chi Chaung, Ko-Tung Chang

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Within the field of immunotherapy, oncolytic virotherapy (OVT) employs dual approaches that directly eliminate tumor cells while preserving healthy ones and indirectly reprogram the tumor microenvironment (TME) to elicit antitumor responses. Within the TME, tumor associated macrophages (TAMs) manifest characteristics akin to those of anti-inflammatory M2 macrophages, thus earning the designation of M2-like TAMs. In prior research, two antigens denoted as A1 (g6Ld10T) and A3 (ORF6L5), derived from a complete sequence of ORF5 with partial sequence of ORF6 in Porcine Reproductive and Respiratory Syndrome Virus Genotype 2 (PRRSV-2), demonstrated the capacity to repolarize M2-type porcine alveolar macrophages (PAMs) into M1 phenotypes. In this study, we sought for utilizing OVT strategies by introducing A1 or A3 on TAMs to endow them with the anti-tumor traits of M1 macrophages while retaining their capacity to target cancer cells. Upon exposing human THP-1-derived M2 macrophages to a cross-species test with 2 µg/ml of either A1 or A3 for 24 hours, real time PCR revealed that A3, but not A1, treated cells exhibited upregulated gene expressions of M1 markers (CCR7, IL-1ß, CCL2, Cox2, CD80). These cells reacted to virus-derived antigen, as evidenced by increased expression of pattern-recognition receptors TLR3, TLR7, and TLR9, subsequently providing feedback in the form of type I interferon responses like IFNAR1, IFN-ß, IRF3, IRF7, OAS1, Mx1, and ISG15. Through an MTT assay, only after 15 µg/ml of A3 treatment could the cell viability decrease, with a predicted IC50 of 16.96 µg/ml. Interestingly, A3 caused dose-dependent toxicity to a rat C6 glial cancer cell line even at doses as low as 2.5 µg/ml and reached its IC50 at 9.419 µg/ml. Using Annexin V/7AAD staining and PCR test, we deduced that a significant proportion of C6 cells were undergoing the early apoptosis phase predominantly through the intrinsic apoptosis cascade involving Bcl-2 family proteins. Following this stage, we conducted a test on A3’s repolarization ability, which revealed a significant rise in M1 gene expression markers, such as TNF, CD80, and IL-1ß, in M2-like TAMs generated in vitro from murine RAW264.7 macrophages grown with conditioned medium of 4T1 breast cancer cells. This was corroborated by the results of transcriptome analysis, which revealed that the primary subset among the top 10 to top 30 significantly upregulated differentially expressed genes (DEGs) dominantly consisted of M1 macrophages profiles, including Ccl3, Ccl4, Csf3, TNF, Bcl6b, Stc1, and Dusp2. Our findings unveiled the remarkable potential of the PRRSV-derived antigen A3 to repolarize macrophages while also being capable of selectively inducing apoptosis in cancerous cells. While further in vivo study is needed for A3, it holds promise as an adjuvant by its dual effects in cancer therapy modalities.

Keywords: cancer cell apoptosis, interferon responses, macrophage repolarization, recombinant protein

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Authors: Jonathan Kissi, Baozhen Dai, Wisdom W. K. Pomegbe, Abdul-Basit Kassim

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Protecting patient’s digital information is a growing concern for healthcare institutions as people nowadays perpetually live their lives through telemedicine services. These telemedicine services have been confronted with several determinants that hinder their successful implementations, especially in developing countries. Identifying such determinants that influence the acceptance of telemedicine services is also a problem for healthcare professionals. Despite the tremendous increase in telemedicine services, its adoption, and use has been quite slow in some healthcare settings. Generally, it is accepted in today’s globalizing world that the success of telemedicine services relies on users’ satisfaction. Satisfying health professionals and patients are one of the crucial objectives of telemedicine success. This study seeks to investigate the determinants that influence health professionals’ intention to utilize telemedicine services in clinical activities in a sub-Saharan African country in West Africa (Ghana). A hybridized model comprising of health adoption models, including technology acceptance theory, diffusion of innovation theory, and protection of motivation theory, were used to investigate these quandaries. The study was carried out in four government health institutions that apply and regulate telemedicine services in their clinical activities. A structured questionnaire was developed and used for data collection. Purposive and convenience sampling methods were used in the selection of healthcare professionals from different medical fields for the study. The collected data were analyzed based on structural equation modeling (SEM) approach. All selected constructs showed a significant relationship with health professional’s behavioral intention in the direction expected from prior literature including perceived usefulness, perceived ease of use, management strategies, financial sustainability, communication channels, patients security threat, patients privacy risk, self efficacy, actual service use, user satisfaction, and telemedicine services systems securities threat. Surprisingly, user characteristics and response efficacy of health professionals were not significant in the hybridized model. The findings and insights from this research show that health professionals are pragmatic when making choices for technology applications and also their willingness to use telemedicine services. They are, however, anxious about its threats and coping appraisals. The identified significant constructs in the study may help to increase efficiency, quality of services, quality patient care delivery, and satisfactory user satisfaction among healthcare professionals. The implantation and effective utilization of telemedicine services in the selected hospitals will aid as a strategy to eradicate hardships in healthcare services delivery. The service will help attain universal health access coverage to all populace. This study contributes to empirical knowledge by identifying the vital factors influencing health professionals’ behavioral intentions to adopt telemedicine services. The study will also help stakeholders of healthcare to formulate better policies towards telemedicine service usage.

Keywords: telemedicine service, perceived usefulness, perceived ease of use, management strategies, security threats

Procedia PDF Downloads 110

Authors: Jenson George, Thoa Nguyen, Garth Sanewski, Craig Hardner, Heather Eunice Smyth

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Pineapple (Ananas comosus), with its unique sweet flavour, is one of the most popular tropical, non-climacteric fruits consumed worldwide. It is also the third most important tropical fruit in world production. In Australia, 99% of the pineapple production is from the Queensland state due to the favourable subtropical climatic conditions. The flavourful fruit is known to contain around 500 volatile organic compounds (VOC) at varying concentrations and greatly contribute to the flavour quality of pineapple fruit by providing distinct aroma sensory properties that are sweet, fruity, tropical, pineapple-like, caramel-like, coconut-like, etc. The aroma of pineapple is one of the important factors attracting consumers and strengthening the marketplace. To better understand the aroma of Australian-grown pineapples, the matrix-matched Gas chromatography–mass spectrometry (GC-MS), Head Space - Solid-phase microextraction (HS-SPME), Stable-isotope dilution analysis (SIDA) method was developed and validated. The developed method represents a significant improvement over current methods with the incorporation of multiple external reference standards, multiple isotopes labeled internal standards, and a matching model system of pineapple fruit matrix. This method was employed to quantify 28 key aroma compounds in more than 200 genetically diverse pineapple varieties from a breeding program. The Australian pineapple cultivars varied in content and composition of free volatile compounds, which were predominantly comprised of esters, followed by terpenes, alcohols, aldehydes, and ketones. Using selected commercial cultivars grown in Australia, and by employing the sensorial analysis, the appearance (colour), aroma (intensity, sweet, vinegar/tang, tropical fruits, floral, coconut, green, metallic, vegetal, fresh, peppery, fermented, eggy/sulphurous) and texture (crunchiness, fibrousness, and juiciness) were obtained. Relationships between sensory descriptors and volatiles were explored by applying multivariate analysis (PCA) to the sensorial and chemical data. The key aroma compounds of pineapple exhibited a positive correlation with corresponding sensory properties. The sensory and volatile data were also used to explore genetic diversity in the breeding population. GWAS was employed to unravel the genetic control of the pineapple volatilome and its interplay with fruit sensory characteristics. This study enhances our understanding of pineapple aroma (flavour) compounds, their biosynthetic pathways and expands breeding option for pineapple cultivars. This research provides foundational knowledge to support breeding programs, post-harvest and target market studies, and efforts to optimise the flavour of commercial pineapple varieties and their parent lines to produce better tasting fruits for consumers.

Keywords: Ananas comosus, pineapple, flavour, volatile organic compounds, aroma, Gas chromatography–mass spectrometry (GC-MS), Head Space - Solid-phase microextraction (HS-SPME), Stable-isotope dilution analysis (SIDA).

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Authors: A. Gonzalez Aguna, J. M. Santamaria Garcia, J. L. Gomez Gonzalez, R. Barchino Plata, M. Fernandez Batalla, S. Herrero Jaen

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Background: Computer Science is a field that transcends other disciplines of knowledge because it allows to support all kinds of physical and mental tasks. Health centres have a greater number and complexity of technological devices and the population consume and demand services derived from technology. Also, nursing education plans have included competencies related to and, even, courses about new technologies are offered to health professionals. However, nurses still limit their performance to the use and evaluation of products previously built. Objective: Develop a teaching-learning methodology for acquiring skills on designing applications for care. Methodology: Blended learning teaching with a group of graduate nurses through official training within a Master's Degree. The study sample was selected by intentional sampling without exclusion criteria. The study covers from 2015 to 2017. The teaching sessions included a four-hour face-to-face class and between one and three tutorials. The assessment was carried out by written test consisting of the preparation of an IEEE 830 Standard Specification document where the subject chosen by the student had to be a problem in the area of care. Results: The sample is made up of 30 students: 10 men and 20 women. Nine students had a degree in nursing, 20 diploma in nursing and one had a degree in Computer Engineering. Two students had a degree in nursing specialty through residence and two in equivalent recognition by exceptional way. Except for the engineer, no subject had previously received training in this regard. All the sample enrolled in the course received the classroom teaching session, had access to the teaching material through a virtual area and maintained at least one tutoring. The maximum of tutorials were three with an hour in total. Among the material available for consultation was an example of a document drawn up based on the IEEE Standard with an issue not related to care. The test to measure competence was completed by the whole group and evaluated by a multidisciplinary teaching team of two computer engineers and two nurses. Engineers evaluated the correctness of the characteristics of the document and the degree of comprehension in the elaboration of the problem and solution elaborated nurses assessed the relevance of the chosen problem statement, the foundation, originality and correctness of the proposed solution and the validity of the application for clinical practice in care. The results were of an average grade of 8.1 over 10 points, a range between 6 and 10. The selected topic barely coincided among the students. Examples of care areas selected are care plans, family and community health, delivery care, administration and even robotics for care. Conclusion: The applied methodology of learning-teaching for the design of technologies demonstrates the success in the training of nursing professionals. The role of expert is essential to create applications that satisfy the needs of end users. Nursing has the possibility, the competence and the duty to participate in the process of construction of technological tools that are going to impact in care of people, family and community.

Keywords: care, learning, nursing, technology

Procedia PDF Downloads 108

Authors: Xingyu Gao, Qiang Wu, Yuanyuan Liu, Yue Yang

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In the era of the knowledge economy, the relationship between scientific knowledge and patents has garnered significant attention. Understanding the intricate interplay between the foundations of science and technological innovation has emerged as a pivotal challenge for both researchers and policymakers. This study establishes a coupled network of artificial intelligence patents based on co-cited scientific papers. Leveraging centrality metrics from network analysis offers a fresh perspective on understanding the influence of information flow and knowledge sharing within the network on patent impact. The study initially obtained patent numbers for 446,890 granted US AI patents from the United States Patent and Trademark Office’s artificial intelligence patent database for the years 2002-2020. Subsequently, specific information regarding these patents was acquired using the Lens patent retrieval platform. Additionally, a search and deduplication process was performed on scientific non-patent references (SNPRs) using the Web of Science database, resulting in the selection of 184,603 patents that cited 37,467 unique SNPRs. Finally, this study constructs a coupled network comprising 59,379 artificial intelligence patents by utilizing scientific papers co-cited in patent backward citations. In this network, nodes represent patents, and if patents reference the same scientific papers, connections are established between them, serving as edges within the network. Nodes and edges collectively constitute the patent coupling network. Structural characteristics such as node degree centrality, betweenness centrality, and closeness centrality are employed to assess the scientific connections between patents, while citation count is utilized as a quantitative metric for patent influence. Finally, a negative binomial model is employed to test the nonlinear relationship between these network structural features and patent influence. The research findings indicate that network structural features such as node degree centrality, betweenness centrality, and closeness centrality exhibit inverted U-shaped relationships with patent influence. Specifically, as these centrality metrics increase, patent influence initially shows an upward trend, but once these features reach a certain threshold, patent influence starts to decline. This discovery suggests that moderate network centrality is beneficial for enhancing patent influence, while excessively high centrality may have a detrimental effect on patent influence. This finding offers crucial insights for policymakers, emphasizing the importance of encouraging moderate knowledge flow and sharing to promote innovation when formulating technology policies. It suggests that in certain situations, data sharing and integration can contribute to innovation. Consequently, policymakers can take measures to promote data-sharing policies, such as open data initiatives, to facilitate the flow of knowledge and the generation of innovation. Additionally, governments and relevant agencies can achieve broader knowledge dissemination by supporting collaborative research projects, adjusting intellectual property policies to enhance flexibility, or nurturing technology entrepreneurship ecosystems.

Keywords: centrality, patent coupling network, patent influence, social network analysis

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Authors: Oleg Kabantsev, Karomatullo Umarov

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The engineering analysis of earthquake consequences demonstrates a significantly different level of damage to load-bearing systems of different types. Buildings with reinforced concrete columns and separate shear-walls receive the highest level of damage. Traditional methods for predicting damage under earthquake excitations do not provide an answer to the question about the reasons for the increased vulnerability of reinforced concrete frames with shear-walls bearing systems. Thus, the study of the problem of formation and accumulation of damages in the structures reinforced concrete frame with shear-walls requires the use of new methods of assessment of the stress-strain state, as well as new approaches to the calculation of the distribution of forces and stresses in the load-bearing system based on account of various mechanisms of elastic-plastic deformation of reinforced concrete columns and walls. The results of research into the processes of non-linear deformation of structures with a transition to destruction (collapse) will allow to substantiate the characteristics of limit states of various structures forming an earthquake-resistant load-bearing system. The research of elastic-plastic deformation processes of reinforced concrete structures of frames with shear-walls is carried out on the basis of experimentally established parameters of limit deformations of concrete and reinforcement under dynamic excitations. Limit values of deformations are defined for conditions under which local damages of the maximum permissible level are formed in constructions. The research is performed by numerical methods using ETABS software. The research results indicate that under earthquake excitations, plastic deformations of various levels are formed in various groups of elements of the frame with the shear-wall load-bearing system. During the main period of seismic effects in the shear-wall elements of the load-bearing system, there are insignificant volumes of plastic deformations, which are significantly lower than the permissible level. At the same time, plastic deformations are formed in the columns and do not exceed the permissible value. At the final stage of seismic excitations in shear-walls, the level of plastic deformations reaches values corresponding to the plasticity coefficient of concrete , which is less than the maximum permissible value. Such volume of plastic deformations leads to an increase in general deformations of the bearing system. With the specified parameters of the deformation of the shear-walls in concrete columns, plastic deformations exceeding the limiting values develop, which leads to the collapse of such columns. Based on the results presented in this study, it can be concluded that the application seismic-force-reduction factor, common for the all load-bearing system, does not correspond to the real conditions of formation and accumulation of damages in elements of the load-bearing system. Using a single coefficient of seismic-force-reduction factor leads to errors in predicting the seismic resistance of reinforced concrete load-bearing systems. In order to provide the required level of seismic resistance buildings with reinforced concrete columns and separate shear-walls, it is necessary to use values of the coefficient of seismic-force-reduction factor differentiated by types of structural groups.1

Keywords: reinforced concrete structures, earthquake excitation, plasticity coefficients, seismic-force-reduction factor, nonlinear dynamic analysis

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Authors: Dibyendu Rakshit, Santosh K. Sarkar

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The study illustrates a comprehensive account of large-scale changes plankton community structure in relevance to water quality characteristics due to anthropogenic stresses, mainly concerned for Annual Gangasagar Festival (AGF) at the southern tip of Sagar Island of Indian Sundarban wetland for 3-year duration (2012-2014; n=36). This prograding, vulnerable and tide-dominated megadelta has been formed in the estuarine phase of the Hooghly Estuary infested by largest continuous tract of luxurious mangrove forest, enriched with high native flora and fauna. The sampling strategy was designed to characterize the changes in plankton community and water quality considering three diverse phases, namely during festival period (January) and its pre - (December) as well as post (February) events. Surface water samples were collected for estimation of different environmental variables as well as for phytoplankton and microzooplankton biodiversity measurement. The preservation and identification techniques of both biotic and abiotic parameters were carried out by standard chemical and biological methods. The intensive human activities lead to sharp ecological changes in the context of poor water quality index (WQI) due to high turbidity (14.02±2.34 NTU) coupled with low chlorophyll a (1.02±0.21 mg m-3) and dissolved oxygen (3.94±1.1 mg l-1), comparing to pre- and post-festival periods. Sharp reduction in abundance (4140 to 2997 cells l-1) and diversity (H′=2.72 to 1.33) of phytoplankton and microzooplankton tintinnids (450 to 328 ind l-1; H′=4.31 to 2.21) was very much pronounced. The small size tintinnid (average lorica length=29.4 µm; average LOD=10.5 µm) composed of Tintinnopsis minuta, T. lobiancoi, T. nucula, T. gracilis are predominant and reached some of the greatest abundances during the festival period. Results of ANOVA revealed a significant variation in different festival periods with phytoplankton (F= 1.77; p=0.006) and tintinnid abundance (F= 2.41; P=0.022). RELATE analyses revealed a significant correlation between the variations of planktonic communities with the environmental data (R= 0.107; p= 0.005). Three distinct groups were delineated from principal component analysis, in which a set of hydrological parameters acted as the causative factor(s) for maintaining diversity and distribution of the planktonic organisms. The pronounced adverse impact of anthropogenic stresses on plankton community could lead to environmental deterioration, disrupting the productivity of benthic and pelagic ecosystems as well as fishery potentialities which directly related to livelihood services. The festival can be considered as multiple drivers of changes in relevance to beach erosion, shoreline changes, pollution from discarded plastic and electronic wastes and destruction of natural habitats resulting loss of biodiversity. In addition, deterioration in water quality was also evident from immersion of idols, causing detrimental effects on aquatic biota. The authors strongly recommend for adopting integrated scientific and administrative strategies for resilience, sustainability and conservation of this megadelta.

Keywords: Gangasagar festival, phytoplankton, Sundarban megadelta, tintinnid

Procedia PDF Downloads 204

Authors: Luis F. Caballero-castro, Dirsa Feliciano, Daniela Novoa, Orlando Arroyo, Jesús D. Villalba-morales

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Colombia faces a critical challenge in seismic resilience due to the prevalence of informal housing, which constitutes approximately 70% of residential structures. More than 10 million Colombians (20% of the population), live in homes susceptible to collapse in the event of an earthquake. This, combined with the fact that 83% of the population is in intermediate and high seismic hazard areas, has brought serious consequences to the country. These consequences became evident during the 1999 Armenia earthquake, which affected nearly 100,000 properties and represented economic losses equivalent to 1.88% of that year's Gross Domestic Product (GDP). Despite previous efforts to reinforce informal housing through methods like externally reinforced masonry walls, alternatives related to seismic protection systems (SPDs), such as Buckling-Restrained Braces (BRB), have not yet been explored in the country. BRBs are reinforcement elements capable of withstanding both compression and tension, making them effective in enhancing the lateral stiffness of structures. In this study, the use of low-cost and easily installable BRBs for the retrofit of informal housing in Colombia was evaluated, considering the economic limitations of the communities. For this purpose, a case study was selected involving an informally constructed dwelling in the country, from which field information on its structural characteristics and construction materials was collected. Based on the gathered information, nonlinear models with and without BRBs were created, and their seismic performance was analyzed and compared through incremental static (pushover) and nonlinear dynamic analyses. In the first analysis, the capacity curve was identified, showcasing the sequence of failure events occurring from initial yielding to structural collapse. In the second case, the model underwent nonlinear dynamic analyses using a set of seismic records consistent with the country's seismic hazard. Based on the results, fragility curves were calculated to evaluate the probability of failure of the informal housings before and after the intervention with BRBs, providing essential information about their effectiveness in reducing seismic vulnerability. The results indicate that low-cost BRBs can significantly increase the capacity of informal housing to withstand earthquakes. The dynamic analysis revealed that retrofit structures experienced lower displacements and deformations, enhancing the safety of residents and the seismic performance of informally constructed houses. In other words, the use of low-cost BRBs in the retrofit of informal housing in Colombia is a promising strategy for improving structural safety in seismic-prone areas. This study emphasizes the importance of seeking affordable and practical solutions to address seismic risk in vulnerable communities in earthquake-prone regions in Colombia and serves as a model for addressing similar challenges of informal housing worldwide.

Keywords: buckling-restrained braces, fragility curves, informal housing, incremental dynamic analysis, seismic retrofit

Procedia PDF Downloads 63

Authors: Rahbel Rahman, Rogério Meireles Pinto, Margareth Santos Zanchetta

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Background: Existing shortcomings of current health-service delivery include poor teamwork, competencies that do not address consumer needs, and episodic rather than continuous care. Brazil’s Sistema Único de Saúde (Unified Health System, UHS) is acknowledged worldwide as a model for delivering community-based care through Estratégia Saúde da Família (FHS; Family Health Strategy) interdisciplinary teams, comprised of Community Health Agents (in Portuguese, Agentes Comunitário de Saude, ACS), nurses, and physicians. FHS teams are mandated to collectively offer clinical care, disease prevention services, vector control, health surveillance and social services. Our study compares medical providers (nurses and physicians) and community-based providers (ACS) on their perceptions of work environment, professional skills, cognitive capacities and job context. Global health administrators and policy makers can leverage on similarities and differences across care providers to develop interprofessional training for community-based primary care. Methods: Cross-sectional data were collected from 168 ACS, 62 nurses and 32 physicians in Brazil. We compared providers’ demographic characteristics (age, race, and gender) and job context variables (caseload, work experience, work proximity to community, the length of commute, and familiarity with the community). Providers perceptions were compared to their work environment (work conditions and work resources), professional skills (consumer-input, interdisciplinary collaboration, efficacy of FHS teams, work-methods and decision-making autonomy), and cognitive capacities (knowledge and skills, skill variety, confidence and perseverance). Descriptive and bi-variate analysis, such as Pearson Chi-square and Analysis of Variance (ANOVA) F-tests, were performed to draw comparisons across providers. Results: Majority of participants were ACS (64%); 24% nurses; and 12% physicians. Majority of nurses and ACS identified as mixed races (ACS, n=85; nurses, n=27); most physicians identified as males (n=16; 52%), and white (n=18; 58%). Physicians were less likely to incorporate consumer-input and demonstrated greater decision-making autonomy than nurses and ACS. ACS reported the highest levels of knowledge and skills but the least confidence compared to nurses and physicians. ACS, nurses, and physicians were efficacious that FHS teams improved the quality of health in their catchment areas, though nurses tend to disagree that interdisciplinary collaboration facilitated their work. Conclusion: To our knowledge, there has been no study comparing key demographic and cognitive variables across ACS, nurses and physicians in the context of their work environment and professional training. We suggest that global health systems can leverage upon the diverse perspectives of providers to implement a community-based primary care model grounded in interprofessional training. Our study underscores the need for in-service trainings to instill reflective skills of providers, improve communication skills of medical providers and curative skills of ACS. Greater autonomy needs to be extended to community based providers to offer care integral to addressing consumer and community needs.

Keywords: global health systems, interdisciplinary health teams, community health agents, community-based care

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Authors: Masoume Ehsani, Ning Zhu, Huu Doan, Ali Lohi, Amira Abdelrasoul

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Membrane fouling poses severe challenges in membrane-based wastewater treatment applications. Ultrasound (US) has been considered an effective fouling remediation technique in filtration processes. Bubble cavitation in the liquid medium results from the alternating rarefaction and compression cycles during the US irradiation at sufficiently high acoustic pressure. Cavitation microbubbles generated under US irradiation can cause eddy current and turbulent flow within the medium by either oscillating or discharging energy to the system through microbubble explosion. Turbulent flow regime and shear forces created close to the membrane surface cause disturbing the cake layer and dislodging the foulants, which in turn improve the cleaning efficiency and filtration performance. Therefore, the number, size, velocity, and oscillation pattern of the microbubbles created in the liquid medium play a crucial role in foulant detachment and permeate flux recovery. The goal of the current study is to gain in depth understanding of the influence of the US power intensity and frequency on the microbubble dynamics and its characteristics generated under US irradiation. In comparison with other imaging techniques, the synchrotron in-line Phase Contrast Imaging technique at the Canadian Light Source (CLS) allows in-situ observation and real-time visualization of microbubble dynamics. At CLS biomedical imaging and therapy (BMIT) polychromatic beamline, the effective parameters were optimized to enhance the contrast gas/liquid interface for the accuracy of the qualitative and quantitative analysis of bubble cavitation within the system. With the high flux of photons and the high-speed camera, a typical high projection speed was achieved; and each projection of microbubbles in water was captured in 0.5 ms. ImageJ software was used for post-processing the raw images for the detailed quantitative analyses of microbubbles. The imaging has been performed under the US power intensity levels of 50 W, 60 W, and 100 W, in addition to the US frequency levels of 20 kHz, 28 kHz, and 40 kHz. For the duration of 2 seconds of imaging, the effect of the US power and frequency on the average number, size, and fraction of the area occupied by bubbles were analyzed. Microbubbles’ dynamics in terms of their velocity in water was also investigated. For the US power increase of 50 W to 100 W, the average bubble number and the average bubble diameter were increased from 746 to 880 and from 36.7 µm to 48.4 µm, respectively. In terms of the influence of US frequency, a fewer number of bubbles were created at 20 kHz (average of 176 bubbles rather than 808 bubbles at 40 kHz), while the average bubble size was significantly larger than that of 40 kHz (almost seven times). The majority of bubbles were captured close to the membrane surface in the filtration unit. According to the study observations, membrane cleaning efficiency is expected to be improved at higher US power and lower US frequency due to the higher energy release to the system by increasing the number of bubbles or growing their size during oscillation (optimum condition is expected to be at 20 kHz and 100 W).

Keywords: bubble dynamics, cavitational bubbles, membrane fouling, ultrasonic cleaning

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Authors: L. Kutateldze, T. Urushadze, R. Khvedelidze, N. Zakariashvili, I. Khokhashvili, T. Sadunishvili

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Microbial cellulase/xylanase have shown their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing, and agriculture. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Representatives of the genera Aspergillus, Penicillium and Trichoderma are outstanding by relatively high activities of these enzymes. Among the producers were revealed thermophilic strains, representatives of the genus Aspergillus-Aspergillus terreus, Aspergillus versicolor, Aspergillus wentii, also strains of Sporotrichum pulverulentum and Chaetomium thermophile. As a result of optimization of cultivation media and conditions, activities of enzymes produced by the strains have been increased by 4 -189 %. Two strains, active producers of cellulase/xylanase – Penicillium canescence E2 (mesophile) and Aspergillus versicolor Z17 (thermophile) were chosen for further studies. Cellulase/xylanase enzyme preparations from two different genera of microscopic fungi Penicillium canescence E2 and Aspergillus versicolor Z 17 were obtained with activities 220 U/g /1200 U/g and 125 U/g /940 U/g, correspondingly. Main technical characteristics were as follows: the highest enzyme activities were obtained for mesophilic strain Penicillium canescence E2 at 45-500C, while almost the same enzyme activities were fixed for the thermophilic strain Aspergillus versicolor Z 17 at temperature 60-65°C, exceeding the temperature optimum of the mesophile by 150C. Optimum pH of action of the studied cellulase/xylanases from mesophileic and thermophilic strains were similar and equaled to 4.5-5.0 It has been shown that cellulase/xylanase technical preparations from selected strains of Penicillium canescence E2 and Aspergillus versicolor Z17 hydrolyzed cellulose of untreated wheat straw to reducible sugars by 46-52%, and to glucose by 22-27%. However the thermophilic enzyme preparations from the thermophilic A.versicolor strains conducted the process at 600C higher by 100C as compared to mesophlic analogue. Rate of hydrolyses of the pretreated substrate by the same enzyme preparations to reducible sugars and glucose conducted at optimum for their action 60 and 500C was 52-61% and 29-33%, correspondingly. Thus, maximum yield of glucose and reducible sugars form untreated and pretreated wheat straw was achieved at higher temperature (600C) by enzyme preparations from thermophilic strain, which gives advantage for their industrial application.

Keywords: cellulase/xylanase, cellulose hydrolysis, microscopic fungi, thermophilic strain

Procedia PDF Downloads 261

Authors: Yu-Mei Hsueh, Wei-Jen Chen, Yung-Kai Huang, Cheng-Shiuan Tsai, Kuo-Cheng Yeh

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Prostate cancer occurs in men over the age of 50, and rank sixth of the top ten cancers in Taiwan, and the incidence increased gradually over the past decade in Taiwan. Arsenic is confirmed as a carcinogen by International Agency for Research on (IARC). Arsenic induces oxidative stress may be a risk factor for prostate cancer, but the mechanism is not clear. Selenium is an important antioxidant element. Whether the association between plasma selenium levels and risk of prostate cancer are modified by different genotype of selenoprotein is still unknown. Glutathione peroxidase, selenoprotein P (SEPP1) and 15 kDa selenoprotein (SEP 15) are selenoprotein and regulates selenium transport and the oxidation and reduction reaction. However, the association between gene polymorphisms of selenoprotein and prostate cancer is not yet clear. The aim of this study is to determine the relationship between plasma selenium, polymorphism of selenoprotein, urinary total arsenic concentration and prostate cancer. This study is a hospital-based case-control study. Three hundred twenty-two cases of prostate cancer and age (±5 years) 1:1 matched 322 control group were recruited from National Taiwan University Hospital, Taipei Medical University Hospital, and Wan Fang Hospital. Well-trained personnel carried out standardized personal interviews based on a structured questionnaire. Information collected included demographic and socioeconomic characteristics, lifestyle and disease history. Blood and urine samples were also collected at the same time. The Research Ethics Committee of National Taiwan University Hospital, Taipei, Taiwan, approved the study. All patients provided informed consent forms before sample and data collection. Buffy coat was to extract DNA, and the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) was used to measure the genotypes of SEPP1 rs3797310, SEP15 rs5859, GPX1 rs1050450, GPX2 rs4902346, GPX3 rs4958872, and GPX4 rs2075710. Plasma concentrations of selenium were determined by inductively coupled plasma mass spectrometry (ICP-MS).Urinary arsenic species concentrations were measured by high-performance liquid chromatography links hydride generator and atomic absorption spectrometer (HPLC-HG-AAS). Subject with high education level compared to those with low educational level had a lower prostate cancer odds ratio (OR) Mainland Chinese and aboriginal people had a lower OR of prostate cancer compared to Fukien Taiwanese. After adjustment for age, educational level, subjects with GPX1 rs1050450 CT and TT genotype compared to the CC genotype have lower, OR of prostate cancer, the OR and 95% confidence interval (Cl) was 0.53 (0.31-0.90). SEPP1 rs3797310 CT+TT genotype compared to those with CC genotype had a marginally significantly lower OR of PC. The low levels of plasma selenium and the high urinary total arsenic concentrations had the high OR of prostate cancer in a significant dose-response manner, and SEPP1 rs3797310 genotype modified this joint association.

Keywords: prostate cancer, plasma selenium concentration, urinary total arsenic concentrations, glutathione peroxidase, selenoprotein P, selenoprotein 15, gene polymorphism

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Authors: J. Chamorro-Servent, S. Tassani, M. A. Gonzalez-Ballester, L. J. Roca, J. Romeu, O. Camara

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Electromagnetic and microwave imaging (MWI) have been used in medical imaging in the last years, being the most common applications of breast cancer and stroke detection or monitoring. In those applications, the subject or zone to observe is surrounded by a number of antennas, and the Nyquist criterium can be satisfied. Additionally, the space between the antennas (transmitting and receiving the electromagnetic fields) and the zone to study can be prepared in a homogeneous scenario. However, this may differ in other cases as could be intracardiac catheters, stomach monitoring devices, pelvic organ systems, liver ablation monitoring devices, or uterine fibroids’ ablation systems. In this work, we analyzed different MWI algorithms to find the most suitable method for dealing with an intrabody scenario. Due to the space limitations usually confronted on those applications, the device would have a cylindrical configuration of a maximum of eight transmitters and eight receiver antennas. This together with the positioning of the supposed device inside a body tract impose additional constraints in order to choose a reconstruction method; for instance, it inhabitants the use of well-known algorithms such as filtered backpropagation for diffraction tomography (due to the unusual configuration with probes enclosed by the imaging region). Finally, the difficulty of simulating a realistic non-homogeneous background inside the body (due to the incomplete knowledge of the dielectric properties of other tissues between the antennas’ position and the zone to observe), also prevents the use of Born and Rytov algorithms due to their limitations with a heterogeneous background. Instead, we decided to use a time-reversed algorithm (mostly used in geophysics) due to its characteristics of ignoring heterogeneities in the background medium, and of focusing its generated field onto the scatters. Therefore, a 2D time-reversed finite difference time domain was developed based on the time-reversed approach for microwave breast cancer detection. Simultaneously an in-silico testbed was also developed to compare ground-truth dielectric properties with corresponding microwave imaging reconstruction. Forward and inverse problems were computed varying: the frequency used related to a small zone to observe (7, 7.5 and 8 GHz); a small polyp diameter (5, 7 and 10 mm); two polyp positions with respect to the closest antenna (aligned or disaligned); and the (transmitters-to-receivers) antenna combination used for the reconstruction (1-1, 8-1, 8-8 or 8-3). Results indicate that when using the existent time-reversed method for breast cancer here for the different combinations of transmitters and receivers, we found false positives due to the high degrees of freedom and unusual configuration (and the possible violation of Nyquist criterium). Those false positives founded in 8-1 and 8-8 combinations, highly reduced with the 1-1 and 8-3 combination, being the 8-3 configuration de most suitable (three neighboring receivers at each time). The 8-3 configuration creates a region-of-interest reduced problem, decreasing the ill-posedness of the inverse problem. To conclude, the proposed algorithm solves the main limitations of the described intrabody application, successfully detecting the angular position of targets inside the body tract.

Keywords: FDTD, time-reversed, medical imaging, microwave imaging

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Authors: Hyemi Kim, Jay Kim, Kyunghoon Han, Ra-Yeong Choi, In-Woo Kim, Hyung Joo Suh, Ki-Bae Hong, Sung Hee Han

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Chitosan is used in various industries such as food and medical care because it is known to have various functions such as anti-obesity, anti-inflammatory and anti-cancer benefits. Most of the commercial chitosan is extracted from crustaceans. As the harvest rate of snow crabs and red snow crabs decreases and safety issues arise due to environmental pollution, research is underway to extract chitosan from insects. In this study, we used Response Surface Methodology (RSM) to predict the optimal conditions to produce chitosan oligosaccharides from mealworms (MCOS), which can be absorbed through the intestine as low-molecular-weight chitosan. The experimentally confirmed optimal conditions for MCOS production using chitosanase were found to be a substrate concentration of 2.5%, enzyme addition of 30 mg/g and a reaction time of 6 hours. The chemical structure and physicochemical properties of the produced MCOS were measured using MALDI-TOF mass spectra and FTIR spectra. The MALDI-TOF mass spectra revealed peaks corresponding to the dimer (375.045), trimer (525.214), tetramer (693.243), pentamer (826.296), and hexamer (987.360). In the FTIR spectra, commercial chitosan oligosaccharides exhibited a weak peak pattern at 3500-2500 cm-1, unlike chitosan or chitosan oligosaccharides. There was a difference in the peak at 3200~3500 cm-1, where different vibrations corresponding to OH and amine groups overlapped. Chitosan, chitosan oligosaccharide, and commercial chitosan oligosaccharide showed peaks at 2849, 2884, and 2885 cm-1, respectively, attributed to the absorption of the C-H stretching vibration of methyl or methine. The amide I, amide II, and amide III bands of chitosan, chitosan oligosaccharide, and commercial chitosan oligosaccharide exhibited peaks at 1620/1620/1602, 1553/1555/1505, and 1310/1309/1317 cm-1, respectively. Furthermore, the solubility of MCOS was 45.15±3.43, water binding capacity (WBC) was 299.25±4.57, and fat binding capacity (FBC) was 325.61±2.28 and the solubility of commercial chitosan oligosaccharides was 49.04±9.52, WBC was 280.55±0.50, and FBC was 157.22±18.15. Thus, the characteristics of MCOS and commercial chitosan oligosaccharides are similar. The results of investigating the impact of chitosan oligosaccharide on the proliferation of probiotics revealed increased growth in L. casei, L. acidophilus, and Bif. Bifidum. Therefore, the major short-chain fatty acids produced by gut microorganisms, such as acetic acid, propionic acid, and butyric acid, increased within 24 hours of adding 1% (p<0.01) and 2% (p<0.001) MCOS. The impact of MCOS on the overall gut microbiota was assessed, revealing that the Chao1 index did not show significant differences, but the Simpson index decreased in a concentration-dependent manner, indicating a higher species diversity. The addition of MCOS resulted in changes in the overall microbial composition, with an increase in Firmicutes and Verrucomicrobia (p<0.05) compared to the control group, while Proteobacteria and Actinobacteria (p<0.05) decreased. At the genus level, changes in microbiota due to MCOS supplementation showed an increase in beneficial bacteria like lactobacillus, Romboutsia, Turicibacter, and Akkermansia (p<0.0001) while harmful bacteria like Enterococcus, Morganella, Proterus, and Bacteroides (p<0.0001) decreased. In this study, chitosan oligosaccharides were successfully produced under established conditions from mealworms, and these chitosan oligosaccharides are expected to have prebiotic effects, similar to those obtained from crabs.

Keywords: mealworms, chitosan, chitosan oligosaccharide, prebiotics

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Authors: Umara Nissar Rafiqi, Irum Gul, Nazima Nasrullah, Monica Saifi, Malik Z. Abdin

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Background: Stevia rebaudiana, a member of Asteraceae family is an important medicinal plant and produces a commercially used non-caloric natural sweetener, which is also an alternate herbal cure for diabetes. Steviol glycosides are the main sweetening compounds present in these plants. Secondary metabolites are crucial to the adaption of plants to the environment and its overcoming stress conditions. In agricultural procedures, the abiotic stresses like salinity, high metal toxicity and drought, in particular, are responsible for the majority of the reduction that differentiates yield potential from harvestable yield. Salt stress and heavy metal toxicity lead to increased production of reactive oxygen species (ROS). To avoid oxidative damage due to ROS and osmotic stress, plants have a system of anti-oxidant enzymes along with several stress induced enzymes. This helps in scavenging the ROS and relieve the osmotic stress in different cell compartments. However, whether stress induced toxicity modulates the activity of these enzymes in Stevia rebaudiana is poorly understood. Aim: The present study focussed on the effect of salinity, heavy metal toxicity (lead and mercury) on physiological traits and transcriptional profiling of Stevia rebaudiana. Method: Stevia rebaudiana plants were collected from the Central Institute of Medicinal and Aromatic plants (CIMAP), Patnagar, India and maintained under controlled conditions in a greenhouse at Hamdard University, Delhi, India. The plants were subjected to different concentrations of salt (0, 25, 50 and 75 mM respectively) and heavy metals, lead and mercury (0, 100, 200 and 300 µM respectively). The physiological traits such as shoot length, root numbers, leaf growth were evaluated. The samples were collected at different developmental stages and analysed for transcription profiling by RT-PCR. Transcriptional studies in stevia rebaudiana involves important antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), cytochrome P450 monooxygenase (CYP) and stress induced aquaporin (AQU), auxin repressed protein (ARP-1), Ndhc gene. The data was analysed using GraphPad Prism and expressed as mean ± SD. Result: Low salinity and lower metal toxicity did not affect the fresh weight of the plant. However, this was substantially decreased by 55% at high salinity and heavy metal treatment. With increasing salinity and heavy metal toxicity, the values of all studied physiological traits were significantly decreased. Chlorosis in treated plants was also observed which could be due to changes in Fe:Zn ratio. At low concentrations (upto 25 mM) of NaCl and heavy metals, we did not observe any significant difference in the gene expressions of treated plants compared to control plants. Interestingly, at high salt concentration and high metal toxicity, a significant increase in the expression profile of stress induced genes was observed in treated plants compared to control (p < 0.005). Conclusion: Stevia rebaudiana is tolerant to lower salt and heavy metal concentration. This study also suggests that with the increase in concentrations of salt and heavy metals, harvest yield of S. rebaudiana was hampered.

Keywords: Stevia rebaudiana, natural sweetener, salinity, heavy metal toxicity

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Authors: Milica Carević, Katarina Banjanac, Marija ĆOrović, Ana Milivojević, Nevena Prlainović, Aleksandar Marinković, Dejan Bezbradica

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Nowadays, considering the growing awareness of functional food beneficial effects on human health, due attention is dedicated to the research in the field of obtaining new prominent products exhibiting improved physiological and physicochemical characteristics. Therefore, different approaches to valuable bioactive compounds synthesis have been proposed. β-Galactosidase, for example, although mainly utilized as hydrolytic enzyme, proved to be a promising tool for these purposes. Namely, under the particular conditions, such as high lactose concentration, elevated temperatures and low water activities, reaction of galactose moiety transfer to free hydroxyl group of the alternative acceptor (e.g. different sugars, alcohols or aromatic compounds) can generate a wide range of potentially interesting products. Up to now, galacto-oligosaccharides and lactulose have attracted the most attention due to their inherent prebiotic properties. The goal of this study was to obtain a novel product sorbitol galactoside, using the similar reaction mechanism, namely transgalactosylation reaction catalyzed by β-galactosidase from Aspergillus oryzae. By using sugar alcohol (sorbitol) as alternative acceptor, a diverse mixture of potential prebiotics is produced, enabling its more favorable functional features. Nevertheless, an introduction of alternative acceptor into the reaction mixture contributed to the complexity of reaction scheme, since several potential reaction pathways were introduced. Therefore, the thorough optimization using response surface method (RSM), in order to get an insight into different parameter (lactose concentration, sorbitol to lactose molar ratio, enzyme concentration, NaCl concentration and reaction time) influences, as well as their mutual interactions on product yield and productivity, was performed. In view of product yield maximization, the obtained model predicted optimal lactose concentration 500 mM, the molar ratio of sobitol to lactose 9, enzyme concentration 0.76 mg/ml, concentration of NaCl 0.8M, and the reaction time 7h. From the aspect of productivity, the optimum substrate molar ratio was found to be 1, while the values for other factors coincide. In order to additionally, improve enzyme efficiency and enable its reuse and potential continual application, immobilization of β-galactosidase onto tailored silica nanoparticles was performed. These non-porous fumed silica nanoparticles (FNS)were chosen on the basis of their biocompatibility and non-toxicity, as well as their advantageous mechanical and hydrodinamical properties. However, in order to achieve better compatibility between enzymes and the carrier, modifications of the silica surface using amino functional organosilane (3-aminopropyltrimethoxysilane, APTMS) were made. Obtained support with amino functional groups (AFNS) enabled high enzyme loadings and, more importantly, extremely high expressed activities, approximately 230 mg proteins/g and 2100 IU/g, respectively. Moreover, this immobilized preparation showed high affinity towards sorbitol galactoside synthesis. Therefore, the findings of this study could provided a valuable contribution to the efficient production of physiologically active galactosides in immobilized enzyme reactors.

Keywords: β-galactosidase, immobilization, silica nanoparticles, transgalactosylation

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Authors: John Doe

Abstract:

This paper presents the research project “Escape Through Culture”, which is co-funded by the European Union and national resources through the Operational Programme “Competitiveness, Entrepreneurship and Innovation” 2014-2020 and the Single RTDI State Aid Action "RESEARCH - CREATE - INNOVATE". The project implementation is assumed by three partners, (1) the Computer Technology Institute and Press "Diophantus" (CTI), experienced with the design and implementation of serious games, natural language processing and ICT in education, (2) the Laboratory of Environmental Communication and Audiovisual Documentation (LECAD), part of the University of Thessaly, Department of Architecture, which is experienced with the study of creative transformation and reframing of the urban and environmental multimodal experiences through the use of AR and VR technologies, and (3) “Apoplou”, an IT Company with experience in the implementation of interactive digital applications. The research project proposes the design of innovative infrastructure of digital educational escape games for mobile devices and computers, with the use of Virtual Reality and Augmented Reality for the promotion of Greek cultural heritage in Greece and abroad. In particular, the project advocates the combination of Greek cultural heritage and literature, digital technologies advancements and the implementation of innovative gamifying practices. The cultural experience of the players will take place in 3 layers: (1) In space: the digital games produced are going to utilize the dual character of the space as a cultural landscape (the real space - landscape but also the space - landscape as presented with the technologies of augmented reality and virtual reality). (2) In literary texts: the selected texts of Greek writers will support the sense of place and the multi-sensory involvement of the user, through the context of space-time, language and cultural characteristics. (3) In the philosophy of the "escape game" tool: whether played in a computer environment, indoors or outdoors, the spatial experience is one of the key components of escape games. The innovation of the project lies both in the junction of Augmented/Virtual Reality with the promotion of cultural points of interest, as well as in the interactive, gamified practices of literary texts. The digital escape game infrastructure will be highly interactive, integrating the projection of Greek landscape cultural elements and digital literary text analysis, supporting the creation of escape games, establishing and highlighting new playful ways of experiencing iconic cultural places, such as Elefsina, Skiathos etc. The literary texts’ content will relate to specific elements of the Greek cultural heritage depicted by prominent Greek writers and poets. The majority of the texts will originate from Greek educational content available in digital libraries and repositories developed and maintained by CTI. The escape games produced will be available for use during educational field trips, thematic tourism holidays, etc. In this paper, the methodology adopted for infrastructure development will be presented. The research is based on theories of place, gamification, gaming development, making use of corpus linguistics concepts and digital humanities practices for the compilation and the analysis of literary texts.

Keywords: escape games, cultural landscapes, gamification, digital humanities, literature

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Authors: Jorge Cortés, Alejandra Martínez, Carlos Pérez, Anaid Simón

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The presence of government, news media, and general citizenry in social media allows considering interactions between them as a form of political communication (i.e. the public exchange of contradictory discourses about politics). Twitter’s asymmetrical following model (users can follow, mention or reply to other users that do not follow them) could foster alternative democratic practices and have an impact on Mexican political culture, which has been marked by a lack of direct communication channels between these actors. The research aim is to assess Twitter’s role in political communication practices through the analysis of interaction dynamics between government, news media, and citizens by extracting and visualizing data from Twitter’s API to observe general behavior patterns. The hypothesis is that regardless the fact that Twitter’s features enable direct and horizontal interactions between actors, users repeat traditional dynamics of interaction, without taking full advantage of the possibilities of this medium. Through an interdisciplinary team including Communication Strategies, Information Design, and Interaction Systems, the activity on Twitter generated by the controversy over the presence of Uber in Mexico City was analysed; an issue of public interest, involving aspects such as public opinion, economic interests and a legal dimension. This research includes techniques from social network analysis (SNA), a methodological approach focused on the comprehension of the relationships between actors through the visual representation and measurement of network characteristics. The analysis of the Uber event comprised data extraction, data categorization, corpus construction, corpus visualization and analysis. On the recovery stage TAGS, a Google Sheet template, was used to extract tweets that included the hashtags #UberSeQueda and #UberSeVa, posts containing the string Uber and tweets directed to @uber_mx. Using scripts written in Python, the data was filtered, discarding tweets with no interaction (replies, retweets or mentions) and locations outside of México. Considerations regarding bots and the omission of anecdotal posts were also taken into account. The utility of graphs to observe interactions of political communication in general was confirmed by the analysis of visualizations generated with programs such as Gephi and NodeXL. However, some aspects require improvements to obtain more useful visual representations for this type of research. For example, link¬crossings complicates following the direction of an interaction forcing users to manipulate the graph to see it clearly. It was concluded that some practices prevalent in political communication in Mexico are replicated in Twitter. Media actors tend to group together instead of interact with others. The political system tends to tweet as an advertising strategy rather than to generate dialogue. However, some actors were identified as bridges establishing communication between the three spheres, generating a more democratic exercise and taking advantage of Twitter’s possibilities. Although interactions in Twitter could become an alternative to political communication, this potential depends on the intentions of the participants and to what extent they are aiming for collaborative and direct communications. Further research is needed to get a deeper understanding on the political behavior of Twitter users and the possibilities of SNA for its analysis.

Keywords: interaction, political communication, social network analysis, Twitter

Procedia PDF Downloads 194

Authors: V. V. Fomin, A. P. Mikhailovich, E. M. Agapitov, V. E. Rogachev, E. A. Kostousova, E. S. Perekhodova

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Ground-level landscape photos can be used as a source of objective data on woody vegetation and vegetation dynamics. We proposed a method for processing, analyzing, and presenting ground photographs, which has the following advantages: 1) researcher has to form holistic representation of the study area in form of a set of interlapping ground-level landscape photographs; 2) it is necessary to define or obtain characteristics of the landscape, objects, and phenomena present on the photographs; 3) it is necessary to create new or supplement existing textual descriptions and annotations for the ground-level landscape photographs; 4) single or multiple ground-level landscape photographs can be used to develop specialized geoinformation layers, schematic maps or thematic maps; 5) it is necessary to determine quantitative data that describes both images as a whole, and displayed objects and phenomena, using algorithms for automated image analysis. It is suggested to match each photo with a polygonal geoinformation layer, which is a sector consisting of areas corresponding with parts of the landscape visible in the photos. Calculation of visibility areas is performed in a geoinformation system within a sector using a digital model of a study area relief and visibility analysis functions. Superposition of the visibility sectors corresponding with various camera viewpoints allows matching landscape photos with each other to create a complete and wholesome representation of the space in question. It is suggested to user-defined data or phenomenons on the images with the following superposition over the visibility sector in the form of map symbols. The technology of geoinformation layers’ spatial superposition over the visibility sector creates opportunities for image geotagging using quantitative data obtained from raster or vector layers within the sector with the ability to generate annotations in natural language. The proposed method has proven itself well for relatively open and clearly visible areas with well-defined relief, for example, in mountainous areas in the treeline ecotone. When the polygonal layers of visibility sectors for a large number of different points of photography are topologically superimposed, a layer of visibility of sections of the entire study area is formed, which is displayed in the photographs. Also, as a result of this overlapping of sectors, areas that did not appear in the photo will be assessed as gaps. According to the results of this procedure, it becomes possible to obtain information about the photos that display a specific area and from which points of photography it is visible. This information may be obtained either as a query on the map or as a query for the attribute table of the layer. The method was tested using repeated photos taken from forty camera viewpoints located on Ray-Iz mountain massif (Polar Urals, Russia) from 1960 until 2023. It has been successfully used in combination with other ground-based and remote sensing methods of studying the climate-driven dynamics of woody vegetation in the Polar Urals. Acknowledgment: This research was collaboratively funded by the Russian Ministry for Science and Education project No. FEUG-2023-0002 (image representation) and Russian Science Foundation project No. 24-24-00235 (automated textual description).

Keywords: woody, vegetation, repeated, photographs

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Authors: Andrea N. Alarcon, Julian D. Castro, Gloria C. Rojas, Paola A. Vaca, Santiago Ortiz, Gustavo Martinez, Pablo D. Lemoine

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Recently, electoral results across many countries have shown to be inconsistent with rational decision theory, which states that individuals make decisions based on maximizing benefits and reducing risks. An alternative explanation has emerged: Fear and rage-driven vote have been proved to be highly effective for political persuasion and mobilization. This phenomenon has been evident in the 2016 elections in the United States, 2006 elections in Mexico, 1998 elections in Venezuela, and 2004 elections in Bolivia. In Colombia, it has occurred recently in the 2016 plebiscite for peace and 2018 presidential elections. The aim of this study is to explain this phenomenon using cultural cognition theory, referring to the psychological predisposition individuals have to believe that its own and its peer´s behavior is correct and, therefore, beneficial to the entire society. Cultural cognition refers to the tendency of individuals to fit perceived risks, and factual beliefs into group shared values; the Cultural Cognition Worldview Scales (CCWS) measures cultural perceptions through two different dimensions: Individualism-communitarianism and hierarchy-egalitarianism. The former refers to attitudes towards social dominance based on conspicuous and static characteristics (sex, ethnicity or social class), while the latter refers to attitudes towards a social ordering in which it is expected from individuals to guarantee their own wellbeing without society´s or government´s intervention. A probabilistic national sample was obtained from different polls from the consulting and public opinion company Centro Nacional de Consultoría. Sociodemographic data was obtained along with CCWS scores, a subjective measure of left-right ideological placement and vote intention for 2019 Mayor´s elections were also included in the questionnaires. Finally, the question “In your opinion, what is the greatest risk Colombia is facing right now?” was included to identify perceived risk in the population. Preliminary results show that Colombians are highly distributed among hierarchical communitarians and egalitarian individualists (30.9% and 31.7%, respectively), and to a less extent among hierarchical individualists and egalitarian communitarians (19% and 18.4%, respectively). Males tended to be more hierarchical (p < .000) and communitarian (p=.009) than females. ANOVA´s revealed statistically significant differences between groups (quadrants) for the level of schooling, left-right ideological orientation, and stratum (p < .000 for all), and proportion differences revealed statistically significant differences for groups of age (p < .001). Differences and distributions for vote intention and perceived risks are still being processed and results are yet to be analyzed. Results show that Colombians are differentially distributed among quadrants in regard to sociodemographic data and left-right ideological orientation. These preliminary results indicate that this study may shed some light on why Colombians vote the way they do, and future qualitative data will show the fears emerging from the identified values in the CCWS and the relation this has with vote intention.

Keywords: communitarianism, cultural cognition, egalitarianism, hierarchy, individualism, perceived risks

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Authors: Julien G. Chenet, Mario A. Hernandez, U. Leonardo Rodriguez

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The tropical areas are places where there is scarcity of access to potable water and where renewable energies need further development. They also display high undernourishment levels, even though they are one of the resources-richest areas in the world. In these areas, it is common to count on great extension of soils, high solar radiation and raw water from rain, groundwater, surface water or even saltwater. Even though resources are available, access to them is limited, and the low-density habitat makes central solutions expensive and investments not worthy. In response to this lack of investment, rural inhabitants use fossil fuels and timber as an energy source and import agrochemical for soils fertilization, which increase GHG emissions. The OASIS project brings an answer to this situation. It supplies renewable energy, potable water and organic food. The first step is the determination of the needs of the communities in terms of energy, water quantity and quality, food requirements and soil characteristics. Second step is the determination of the available resources, such as solar energy, raw water and organic residues on site. The pilot OASIS project is located in the Vichada department, Colombia, and ensures the sustainable use of natural resources to meet the community needs. The department has roughly 70% of indigenous people. They live in a very scattered landscape, with no access to clean water and energy. They use polluted surface water for direct consumption and diesel for energy purposes. OASIS pilot will ensure basic needs for a 400-students education center. In this case, OASIS will provide 20 kW of solar energy potential and 40 liters per student per day. Water will be treated form groundwater, with two qualities. A conventional one with chlorine, and as the indigenous people are not used to chlorine for direct consumption, second train is with reverse osmosis to bring conservable safe water without taste. OASIS offers a solution to supply basic needs, shifting from fossil fuels, timber, to a no-GHG-emission solution. This solution is part of the mitigation strategy against Climate Change for the communities in low-density areas of the tropics. OASIS is a learning center to teach how to convert natural resources into utilizable ones. It is also a meeting point for the community with high pedagogic impact that promotes the efficient and sustainable use of resources. OASIS system is adaptable to any tropical area and competes technically and economically with any conventional solution, that needs transport of energy, treated water and food. It is a fully automatic, replicable and sustainable solution to sort out the issue of access to basic needs in rural areas. OASIS is also a solution to undernourishment, ensuring a responsible use of resources, to prevent long-term pollution of soils and groundwater. It promotes the closure of the nutrient cycle, and the optimal use of the land whilst ensuring food security in depressed low-density regions of the tropics. OASIS is under optimization to Vichada conditions, and will be available to any other tropical area in the following months.

Keywords: climate change adaptation and mitigation, rural development, sustainable access to clean and renewable resources, social inclusion

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Authors: M. Fry, L. Fitzpatrick, Julie Considine, R. Z. Shaban, Kate Curtis

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Introduction: The vast majority of older Australians lives independently and are self-managing at home, despite a growing number living with a chronic illness that requires health intervention. Evidence shows that between 50% and 80% of people presenting to the emergency department (ED) are in pain. Australian EDs manage 7.2 million attendances every year and 1.4 million of these are people aged 65 years or more. Research shows that 28% of ED patients aged 65 years or more have Cognitive impairment (CI) associated with dementia, delirium and neurological conditions. Background: Traditional ED service delivery may not be suitable for older people who present with multiple, complex and ongoing illnesses. Likewise, ED clinical staff often perceive that their role should be focused more on immediate and potential lifethreatening illness and conditions which are episodic in nature. Therefore, the needs of older people and their family/carers may not be adequately addressed in the context of an ED presentation. Aim: We aimed to explore the utilisation and characteristics of older people presenting to four metropolitan EDs. Method: The findings being presented are part of a program of research exploring pain management practices for older persons with long bone fractures. The study was conducted across four metropolitan emergency departments of older patients (65years and over) and involved a 12-month randomised medical record audit (n=255). Results: ED presentations across four ED sites in 2012 numbered 168021, with 44778 (26.6%) patients aged 65 and over. Of the 44778 patients, the average age was 79.1 years (SD 8.54). There were more females 23932 (53.5%). The majority (26925: 85.0%) of older persons self-referred to the ED and lived independently. The majority arrived by ambulance (n=18553: 41.4%) and were allocated triage category was 3 (n=19,507:43.65%) or Triage category 4 at (n=15,389: 34.43%). The top five triage symptom presentations involved pain (n=8088; 18.25%), dyspnoea (n=4735; 10.7%), falls (n=4032; 9.1%), other (n=3984; 9.0%), cardiac (n=2987; 6.7%). The top five system based diagnostic presentations involved musculoskeletal (n=8902; 20.1%), cardiac (n=6704:15.0%), respiratory (n=4933; 11.0%), neurological (n=4909; 11.0%), gastroenterology (n=4321; 9.7%). On review of one tertiary hospital database the vital signs on average at time triage: Systolic Blood Pressure 143.6mmHg. Heart Rate 83.4 beats/minute; Respiratory Rate 18.5 breaths/ minute; Oxygen saturation 97.0% and Tympanic temperature 36.7 and Blood Glucose Level 7.4mmols/litre. The majority presented with a Glasgow Coma Score of 14 or higher. On average the older person stayed in the ED 4:56 (SD 3:28minutes).The average time to be seen was 39 minutes (SD 48 minutes). The majority of older persons were admitted (n=27562: 61.5%), did not wait for treatment (n= 8879: 0.02%) discharged home (n=16256: 36.0%). Conclusion: The vast majority of older persons are living independently, although many require admission on arrival to the ED. Many arrived in pain and with musculoskeletal injuries and or conditions. New models of care need to be considered, which may better support self-management and independent living of the older person and the National Emergency Access Targets.

Keywords: chronic, older person, aged care, emergency department

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Authors: A. G. Back

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Urban planning is a relevant tool to address, in a systemic way, several sectoral policies capable of linking the urban agenda with the reduction of socio-environmental risks. The Sao Paulo’s master plan (2014) presents innovations capable of promoting the transition to sustainability in the urban space, with a view to its regulatory instruments related to i) promotion of density in the axes of mass transport involving the mixture of commercial, residential, services, and leisure uses (principles related to the compact city); ii) vulnerabilities reduction based on housing policies including regular sources of funds for social housing and land reservation in urbanized areas; iii) reserve of green areas in the city to create parks and environmental regulations for new buildings focused on reducing the effects of heat island and improving urban drainage. However, its long-term implementation involves distributive conflicts and can undergo changes in different political, economic, and social contexts over time. Thus, the main objective of this paper is to identify and analyze the dynamics of conflicts of interest between social groups in the implementation of Sao Paulo’s urban development policy, particularly in relation to recent attempts at a (re) interpretation of the Master Plan guidelines, in view of the proposals for revision of the urban zoning law. In this sense, we seek to identify the demands, narratives of urban actors, including the real estate market, middle-class neighborhood associations ('not in my backyard' movements), and social housing rights movements. And we seek to analyze the power resources that these actors mobilize to influence the decision-making process, involving five categories: social capital, political access; discursive resource; media, juridical resource. The major findings of this research suggest that the interests and demands of the real estate market do not always prevail in urban regulation. After all, other actors also press for the definition of urban law with interests opposite to those of the real estate market. This is the case of associations of middle-class neighborhoods, which work to protect the characteristics of the locality, acting, in general, to prevent constructive and population densification in neighborhoods well located near the center, in São Paulo. One of the main demands of these “not in my backyard” movements is the delimitation of exclusively residential areas in the central region of the city, which is not only contrary to the interests of the real state market but also contrary to the principles of the compact city. On the other hand, social housing rights movements have also made progress in delimiting special areas of social interest in well-located and valued areas in the city dedicated to building social housing, also contrary to the interests of the real estate market. An urban development that follows the principles of the compact city must take into account the insertion of low-income populations in well-located regions; otherwise, such a development model may continue to push the less favored to the peripheries towards the preservation areas and/or risk areas.

Keywords: interest groups, Sao Paulo, sustainable urban development, urban policies implementation

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Authors: Prajna Paramita Naik, Sujit Kumar Bhutia

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Background: Regardless of the development multimodal treatment strategies, oral squamous cell carcinoma (OSCC) is often associated with a high rate of recurrence, metastasis and chemo- and radio- resistance. The present study inspected the relevance of CD44, ABCB1 and ADAM17 expression as a putative stem cell compartment in oral squamous cell carcinoma (OSCC) and deciphered the role of autophagy in regulating the expression of aforementioned proteins, stemness and chemoresistance. Methods: A retrospective analysis of CD44, ABCB1 and ADAM17 expression with respect to the various clinicopathological factors of sixty OSCC patients were determined via immunohistochemistry. The correlation among CD44, ABCB1 and ADAM17 expression was established. Sphere formation assay, flow cytometry and fluorescence microscopy were conducted to elucidate the stemness and chemoresistance nature of established cisplatin-resistant oral cancer cells (FaDu). The pattern of expression of CD44, ABCB1 and ADAM17 in parental (FaDu-P) and resistant FaDu cells (FaDu-CDDP-R) were investigated through fluorescence microscopy. Western blot analysis of autophagy marker proteins was performed to compare the status of autophagy in parental and resistant FaDu cell. To investigate the role of autophagy in chemoresistance and stemness, sphere formation assay, immunofluorescence and Western blot analysis was performed post transfection with siATG14 and the level of expression of autophagic proteins, mitochondrial protein and stemness-associated proteins were analyzed. The statistical analysis was performed by GraphPad Prism 4.0 software. p-value was defined as follows: not significant (n.s.): p > 0.05;*: p ≤ 0.05; **: p ≤ 0.01; ***: p ≤ 0.001; ****: p ≤ 0.0001 were considered statistically significant. Results: In OSCC, high CD44, ABCB1 and ADAM17 expression were significantly correlated with higher tumor grades and poor differentiation. However, the expression of these proteins was not related to the age and sex of OSCC patients. Moreover, the expression of CD44, ABCB1 and ADAM17 were positively correlated with each other. In vitro and OSCC tissue double labeling experiment data showed that CD44+ cells were highly associated with ABCB1 and ADAM17 expression. Further, FaDu-CDDP-R cells showed higher sphere forming capacity along with increased fraction of the CD44+ population and β-catenin expression FaDu-CDDP-R cells also showed accelerated expression of CD44, ABCB1 and ADAM17. A comparatively higher autophagic flux was observed in FaDu-CDDP-R against FaDu-P cells. The expression of mitochondrial proteins was noticeably reduced in resistant cells as compared to parental cells indicating the occurrence of autophagy-mediated mitochondrial degradation in oral cancer. Moreover, inhibition of autophagy was coupled with the decreased formation of orospheres suggesting autophagy-mediated stemness in oral cancer. Blockade of autophagy was also found to induce the restoration of mitochondrial proteins in FaDu-CDDP-R cells indicating the involvement of mitophagy in chemoresistance. Furthermore, a reduced expression of CD44, ABCB1 and ADAM17 was also observed in ATG14 deficient cells FaDu-P and FaDu-CDDP-R cells. Conclusion: The CD44+ ⁄ABCB1+ ⁄ADAM17+ expression in OSCC might be associated with chemoresistance and a putative CSC compartment. Further, the present study highlights the contribution of mitophagy in chemoresistance and confirms the potential involvement of autophagic regulation in acquisition of stem-like characteristics in OSCC.

Keywords: ABCB1, ADAM17, autophagy, CD44, chemoresistance, mitophagy, OSCC, stemness

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Authors: Alex B. Cusick

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The objective of this study is to improve upon the current ²³⁸PuO₂ fuel technology for space and defense applications. Modern RTGs (radioisotope thermoelectric generators) utilize the heat generated from the radioactive decay of ²³⁸Pu to create heat and electricity for long term and remote missions. Application of RTG technology is limited by the scarcity and expense of producing the isotope, as well as the power output which is limited to only a few hundred watts. The scarcity and expense make the efficient use of ²³⁸Pu absolutely necessary. By utilizing the decay of ²³⁸Pu, not only to produce heat directly but to also indirectly induce fission in ²³⁹Pu (which is already present within currently used fuel), it is possible to see large increases in temperature which allows for a more efficient conversion to electricity and a higher power-to-weight ratio. This concept can reduce the quantity of ²³⁸Pu necessary for these missions, potentially saving millions on investment, while yielding higher power output. Current work investigating radioisotope power systems have focused on improving efficiency of the thermoelectric components and replacing systems which produce heat by virtue of natural decay with fission reactors. The technical feasibility of utilizing (α,n) reactions to induce fission within current radioisotopic fuels has not been investigated in any appreciable detail, and our study aims to thoroughly investigate the performance of many such designs, develop those with highest capabilities, and facilitate experimental testing of these designs. In order to determine the specific design parameters that maximize power output and the efficient use of ²³⁸Pu for future RTG units, MCNP6 simulations have been used to characterize the effects of modifying fuel composition, geometry, and porosity, as well as introducing neutron moderating, reflecting, and shielding materials to the system. Although this project is currently in the preliminary stages, the final deliverables will include sophisticated designs and simulation models that define all characteristics of multiple novel RTG fuels, detailed enough to allow immediate fabrication and testing. Preliminary work has consisted of developing a benchmark model to accurately represent the ²³⁸PuO₂ pellets currently in use by NASA; this model utilizes the alpha transport capabilities of MCNP6 and agrees well with experimental data. In addition, several models have been developed by varying specific parameters to investigate their effect on (α,n) and (n,fi ssion) reaction rates. Current practices in fuel processing are to exchange out the small portion of naturally occurring ¹⁸O and ¹⁷O to limit (α,n) reactions and avoid unnecessary neutron production. However, we have shown that enriching the oxide in ¹⁸O introduces a sufficient (α,n) reaction rate to support significant fission rates. For example, subcritical fission rates above 10⁸ f/cm³-s are easily achievable in cylindrical ²³⁸PuO₂ fuel pellets with a ¹⁸O enrichment of 100%, given an increase in size and a ⁹Be clad. Many viable designs exist and our intent is to discuss current results and future endeavors on this project.

Keywords: radioisotope thermoelectric generators (RTG), Pu-238, subcritical reactors, (alpha, n) reactions

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Authors: Saul Ngarava, Leocadia Zhou, Nomakhaya Monde

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Water crises have the fourth most significant societal impact after weapons of mass destruction, climate change, and extreme weather conditions, ahead of natural disasters. Intricacies between women and water are central to achieving the 2030 Sustainable Development Goals (SDGs). The majority of the 1.2 billion poor people worldwide, with two-thirds being women, and mostly located in Sub Sahara Africa (SSA) and South Asia, do not have access to safe and reliable sources of water. There exist gendered differences in water security based on the division of labour associating women with water. Globally, women and girls are responsible for water collection in 80% of the households which have no water on their premises. Women spend 16 million hours a day collecting water, while men and children spend 6 million and 4 million per day, respectively, which is time foregone in the pursuit of other livelihood activities. Due to their proximity and activities concerning water, women are vulnerable to water insecurity through exposures to water-borne diseases, fatigue from physically carrying water, and exposure to sexual and physical harassment, amongst others. Proximity to treated water and their wellbeing also has an effect on their sensitivity and adaptive capacity to water insecurity. The great distances, difficult terrain and heavy lifting expose women to vulnerabilities of water insecurity. However, few studies have quantified the vulnerabilities and burdens on women, with a few taking a phenomenological qualitative approach. Vulnerability studies have also been scanty in the water security realm, with most studies taking linear forms of either quantifying exposures, sensitivities or adaptive capacities in climate change studies. The current study argues for the need for a water insecurity vulnerability assessment, especially for women into research agendas as well as policy interventions, monitoring, and evaluation. The study sought to identify and provide pathways through which female-headed households were water insecure in South Africa, the 30th driest country in the world. This was through linking the drinking water decision as well as the vulnerability frameworks. Secondary data collected during the 2016 General Household Survey (GHS) was utilised, with a sample of 5928 female-headed households. Principal Component Analysis and Structural Equation Modelling were used to analyse the data. The results show dynamic relationships between water characteristics and water treatment. There were also associations between water access and wealth status of the female-headed households. Association was also found between water access and water treatment as well as between wealth status and water treatment. The study concludes that there are dynamic relationships in water insecurity (exposure, sensitivity, and adaptive capacity) for female-headed households in South Africa. The study recommends that a multi-prong approach is required in tackling exposures, sensitivities, and adaptive capacities to water insecurity. This should include capacitating and empowering women for wealth generation, improve access to water treatment equipment as well as prioritising the improvement of infrastructure that brings piped and safe water to female-headed households.

Keywords: gender, principal component analysis, structural equation modelling, vulnerability, water insecurity

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Authors: Rosa Nadine Danenberg

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In recent years, bottom-up urban development has started growing as an alternative to conventional top-down planning. In large proportions, citizens and communities initiate small-scale interventions; suddenly seeming to form a trend. As a result, more and more cities are witnessing not only the growth of but also an interest in these initiatives, as they bear the potential to reshape urban spaces. Such alternative city-making efforts cause new dynamics in urban governance, with inevitable consequences for the controlled city planning and its administration. The emergence of enabling relationships between top-down and bottom-up actors signals an increasingly common urban practice. Various case studies show that an enabling relationship is possible, yet, how it can be optimally realized stays rather underexamined. Therefore, the seemingly growing worldwide phenomenon of ‘municipal bottom-up urban development’ necessitates an adequate governance structure. As such, the aim of this research is to contribute knowledge to how municipalities can enable citizen-led urban initiatives from a governance innovation perspective. Empirical case-study research in Stockholm and Istanbul, derived from interviews with founders of four citizen-led urban initiatives and one municipal representative in each city, provided valuable insights to possibilities and constraints for enabling practices. On the one hand, diverging outcomes emphasize the extreme oppositional features of both cases (Stockholm and Istanbul). Firstly, both cities’ characteristics are drastically different. Secondly, the ideologies and motifs for the initiatives to emerge vary widely. Thirdly, the major constraints for citizen-led urban initiatives to relate to the municipality are considerably different. Two types of municipality’s organizational structures produce different underlying mechanisms which demonstrate the constraints. The first municipal organizational structure is steered by bureaucracy (Stockholm). It produces an administrative division that brings up constraints such as the lack of responsibility, transparency and continuity by municipal representatives. The second structure is dominated by municipal politics and governmental hierarchy (Istanbul). It produces informality, lack of transparency and a fragmented civil society. In order to cope with the constraints produced by both types of organizational structures, the initiatives have adjusted their organization to the municipality’s underlying structures. On the other hand, this paper has in fact also come to a rather unifying conclusion. Interestingly, the suggested possibilities for an enabling relationship underline converging new urban governance arrangements. This could imply that for the two varying types of municipality’s organizational structures there is an accurate governance structure. Namely, the combination of a neighborhood council with a municipal guide, with allowance for the initiatives to adopt a politicizing attitude is found as coinciding. Especially its combination appears key to redeem varying constraints. A municipal guide steers the initiatives through bureaucratic struggles, is supported by coproduction methods, while it balances out municipal politics. Next, a neighborhood council, that is politically neutral and run by local citizens, can function as an umbrella for citizen-led urban initiatives. What is crucial is that it should cater for a more entangled relationship between municipalities and initiatives with enhanced involvement of the initiatives in decision-making processes and limited involvement of prevailing constraints pointed out in this research.

Keywords: bottom-up urban development, governance innovation, Istanbul, Stockholm

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Authors: Yi H. Wong, Li L. Chan, Chee O. Leong, Stephen Ambu, Joon W. Mak, Priyadashi S. Sahu

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Background: Acanthamoeba is a free-living opportunistic protist which is ubiquitously distributed in the environment. Virulent Acanthamoeba can cause fatal encephalitis in immunocompromised patients and potential blinding keratitis in immunocompetent contact lens wearers. Approximately 24 species have been identified but only the A. castellanii, A. polyphaga and A. culbertsoni are commonly associated with human infections. Until to date, the precise molecular basis for Acanthamoeba pathogenesis remains unclear. Previous studies reported that Acanthamoeba virulence can be diminished through prolonged axenic culture but revived through serial mouse passages. As no clear explanation on this reversible pathogenesis is established, hereby, we postulate that the epigenetic regulators, DNA-methyltransferases (DNMT) and histone-deacetylases (HDAC), could possibly be involved in granting the virulence plasticity of Acanthamoeba spp. Methods: Four rounds of mouse passages were conducted to revive the virulence potential of the virulence-attenuated Acanthamoeba castellanii strain (ATCC 50492). Briefly, each mouse (n=6/group) was inoculated intraperitoneally with Acanthamoebae cells (2x 105 trophozoites/mouse) and incubated for 2 months. Acanthamoebae cells were isolated from infected mouse organs by culture method and subjected to subsequent mouse passage. In vitro cytopathic, encystment and gelatinolytic assays were conducted to evaluate the virulence characteristics of Acanthamoebae isolates for each passage. PCR primers which targeted on the 2 members (DNMT1 and DNMT2) and 5 members (HDAC1 to 5) of the DNMT and HDAC gene families respectively were custom designed. Quantitative real-time PCR (qPCR) was performed to detect and quantify the relative expression of the two gene families in each Acanthamoeba isolates. Beta-tubulin of A. castellanii (Genbank accession no: XP_004353728) was included as housekeeping gene for data normalisation. PCR mixtures were also analyzed by electrophoresis for amplicons detection. All statistical analyses were performed using the paired one-tailed Student’s t test. Results: Our pathogenicity tests showed that the virulence-reactivated Acanthamoeba had a higher degree of cytopathic effect on vero cells, a better resistance to encystment challenge and a higher gelatinolytic activity which was catalysed by serine protease. qPCR assay showed that DNMT1 expression was significantly higher in the virulence-reactivated compared to the virulence-attenuated Acanthamoeba strain (p ≤ 0.01). The specificity of primers which targeted on DNMT1 was confirmed by sequence analysis of PCR amplicons, which showed a 97% similarity to the published DNA-methyltransferase gene of A. castellanii (GenBank accession no: XM_004332804.1). Out of the five primer pairs which targeted on the HDAC family genes, only HDAC4 expression was significantly difference between the two variant strains. In contrast to DNMT1, HDAC4 expression was much higher in the virulence-attenuated Acanthamoeba strain. Conclusion: Our mouse passages had successfully restored the virulence of the attenuated strain. Our findings suggested that DNA-methyltransferase (DNMT1) and histone deacetylase (HDAC4) expressions are associated with virulence potential of Acanthamoeba spp.

Keywords: acanthamoeba, DNA-methyltransferase, histone deacetylase, virulence-associated proteins

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Authors: Inna Kornienko, Svetlana Guryeva, Anatoly Shekhter, Elena Petersen

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Transplantation is an effective treatment option for patients suffering from different end-stage diseases. However, it is plagued by a constant shortage of donor organs and the subsequent need of a lifelong immunosuppressive therapy for the patient. Currently some researchers look towards using of pig organs to replace human organs for transplantation since the matrix derived from porcine organs is a convenient substitute for the human matrix. As an initial step to create a new ex vivo tissue engineered model, optimized protocols have been created to obtain organ-specific acellular matrices and evaluated their potential as tissue engineered scaffolds for culture of normal cells and tumor cell lines. These protocols include decellularization by perfusion in a bioreactor system and immersion-agitation on an orbital shaker with use of various detergents (SDS, Triton X-100) and freezing. Complete decellularization – in terms of residual DNA amount – is an important predictor of probability of immune rejection of materials of natural origin. However, the signs of cellular material may still remain within the matrix even after harsh decellularization protocols. In this regard, the matrices obtained from tissues of low-immunogenic pigs with α3Galactosyl-tranferase gene knock out (GalT-KO) may be a promising alternative to native animal sources. The research included a study of induced effect of frozen and fresh fragments of GalT-KO skin on healing of full-thickness plane wounds in 80 rats. Commercially available wound dressings (Ksenoderm, Hyamatrix and Alloderm) as well as allogenic skin were used as a positive control and untreated wounds were analyzed as a negative control. The results were evaluated on the 4th day after grafting, which corresponds to the time of start of normal wound epithelization. It has been shown that a non-specific immune response in models treated with GalT-Ko pig skin was milder than in all the control groups. Research has been performed to measure technical skin characteristics: stiffness and elasticity properties, corneometry, tevametry, and cutometry. These metrics enabled the evaluation of hydratation level, corneous layer husking level, as well as skin elasticity and micro- and macro-landscape. These preliminary data may contribute to development of personalized transplantable organs from GalT-Ko pigs with significantly limited potential of immune rejection. By applying growth factors to a decellularized skin sample it is possible to achieve various regenerative effects based on the particular situation. In this particular research BMP2 and Heparin-binding EGF-like growth factor have been used. Ideally, a bioengineered organ must be biocompatible, non-immunogenic and support cell growth. Porcine organs are attractive for xenotransplantation if severe immunologic concerns can be bypassed. The results indicate that genetically modified pig tissues with knock-outed α3Galactosyl-tranferase gene may be used for production of low-immunogenic matrix suitable for transplantation.

Keywords: decellularization, low-immunogenic, matrix, scaffolds, transplants

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Authors: Slawomir Wnuk

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Due to widespread implementation of the renewable energy development programs the, solar energy use increasing constantlyacross the world. Accordingly to REN21, in 2020, both on-grid and off-grid solar photovoltaic systems installed capacity reached 760 GWDCand increased by 139 GWDC compared to previous year capacity. However, the photovoltaic solar cells used for primary solar energy conversion into electrical energy has exhibited significant drawbacks. The fundamentaldownside is unstable andlow efficiencythe energy conversion being negatively affected by a rangeof factors. To neutralise or minimise the impact of those factors causing energy losses, researchers have come out withvariedideas. One ofpromising technological solutionsoffered by researchers is PV-MTEG multilayer hybrid system combiningboth photovoltaic cells and thermoelectric generators advantages. A series of experiments was performed on Glasgow Caledonian University laboratory to investigate such a system in operation. In the experiments, the solar simulator Sol3A series was employed as a stable solar irradiation source, and multichannel voltage and temperature data loggers were utilised for measurements. The two layer proposed hybrid systemsimulation model was built up and tested for its energy conversion capability under a variety of the exposure angles to the solar irradiation with a concurrent examination of the temperature distribution inside proposed PV-MTEG structure. The same series of laboratory tests were carried out for a range of various loads, with the temperature and voltage generated being measured and recordedfor each exposure angle and load combination. It was found that increase of the exposure angle of the PV-MTEG structure to an irradiation source causes the decrease of the temperature gradient ΔT between the system layers as well as reduces overall system heating. The temperature gradient’s reduction influences negatively the voltage generation process. The experiments showed that for the exposureangles in the range from 0° to 45°, the ‘generated voltage – exposure angle’ dependence is reflected closely by the linear characteristics. It was also found that the voltage generated by MTEG structures working with the optimal load determined and applied would drop by approximately 0.82% per each 1° degree of the exposure angle increase. This voltage drop occurs at the higher loads applied, getting more steep with increasing the load over the optimal value, however, the difference isn’t significant. Despite of linear character of the generated by MTEG voltage-angle dependence, the temperature reduction between the system structure layers andat tested points on its surface was not linear. In conclusion, the PV-MTEG exposure angle appears to be important parameter affecting efficiency of the energy generation by thermo-electrical generators incorporated inside those hybrid structures. The research revealedgreat potential of the proposed hybrid system. The experiments indicated interesting behaviour of the tested structures, and the results appear to provide valuable contribution into thedevelopment and technological design process for large energy conversion systems utilising similar structural solutions.

Keywords: photovoltaic solar systems, hybrid systems, thermo-electrical generators, renewable energy

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