Search results for: negative ellipticity

Authors: Marina Shakleina, Konstantin Shaklein, Stanislav Yakiro

Abstract:

The digitalization of modern human life over the last decade has facilitated the acquisition, storage, and processing of data, which are used to detect changes in consumer preferences and to improve the internal efficiency of the production process. This emerging trend has attracted academic interest in the use of big data in research. The study focuses on modeling the social comfort of the Russian population for the period 2010-2021 using big data. Big data provides enormous opportunities for understanding human interactions at the scale of society with plenty of space and time dynamics. One of the most popular big data sources is Google Trends. The methodology for assessing social comfort using big data involves several steps: 1. 574 words were selected based on the Harvard IV-4 Dictionary adjusted to fit the reality of everyday Russian life. The set of keywords was further cleansed by excluding queries consisting of verbs and words with several lexical meanings. 2. Search queries were processed to ensure comparability of results: the transformation of data to a 10-point scale, elimination of popularity peaks, detrending, and deseasoning. The proposed methodology for keyword search and Google Trends processing was implemented in the form of a script in the Python programming language. 3. Block and summary integral indicators of social comfort were constructed using the first modified principal component resulting in weighting coefficients values of block components. According to the study, social comfort is described by 12 blocks: ‘health’, ‘education’, ‘social support’, ‘financial situation’, ‘employment’, ‘housing’, ‘ethical norms’, ‘security’, ‘political stability’, ‘leisure’, ‘environment’, ‘infrastructure’. According to the model, the summary integral indicator increased by 54% and was 4.631 points; the average annual rate was 3.6%, which is higher than the rate of economic growth by 2.7 p.p. The value of the indicator describing social comfort in Russia is determined by 26% by ‘social support’, 24% by ‘education’, 12% by ‘infrastructure’, 10% by ‘leisure’, and the remaining 28% by others. Among 25% of the most popular searches, 85% are of negative nature and are mainly related to the blocks ‘security’, ‘political stability’, ‘health’, for example, ‘crime rate’, ‘vulnerability’. Among the 25% most unpopular queries, 99% of the queries were positive and mostly related to the blocks ‘ethical norms’, ‘education’, ‘employment’, for example, ‘social package’, ‘recycling’. In conclusion, the introduction of the latent category ‘social comfort’ into the scientific vocabulary deepens the theory of the quality of life of the population in terms of the study of the involvement of an individual in the society and expanding the subjective aspect of the measurements of various indicators. Integral assessment of social comfort demonstrates the overall picture of the development of the phenomenon over time and space and quantitatively evaluates ongoing socio-economic policy. The application of big data in the assessment of latent categories gives stable results, which opens up possibilities for their practical implementation.

Keywords: big data, Google trends, integral indicator, social comfort

Procedia PDF Downloads 171

Authors: U. E. Mochalova, A. V. Demeneva, Shilkin A. G., J. Yu. Artiushina

Abstract:

Objective. In medical ophthalmology OCT has been actively used in the last decade. It is a modern non-invasive method of high-precision hardware examination, which gives a detailed cross-sectional image of eye tissues structure with a high level of resolution, which provides in vivo morphological information at the microscopic level about corneal tissue, structures of the anterior segment, retina and optic nerve. The purpose of this study was to explore the possibility of using the OCT technology in complex ophthalmological examination in dogs and cats, to characterize the revealed pathological structural changes in corneal tissue in cats and dogs with some of the most common corneal diseases. Procedures. Optical coherence tomography of the cornea was performed in 112 animals: 68 dogs and 44 cats. In total, 224 eyes were examined. Pathologies of the organ of vision included: dystrophy and degeneration of the cornea, endothelial corneal dystrophy, dry eye syndrome, chronic superficial vascular keratitis, pigmented keratitis, corneal erosion, ulcerative stromal keratitis, corneal sequestration, chronic glaucoma and also postoperative period after performed keratoplasty. When performing OCT, we used certified medical devices: "Huvitz HOCT-1/1F», «Optovue iVue 80» and "SOCT Copernicus Revo (60)". Results. The results of a clinical study on the use of optical coherence tomography (OCT)of the cornea in cats and dogs, performed by the authors of the article in the complex diagnosis of keratopathies of variousorigins: endothelial corneal dystrophy, pigmented keratitis, chronic keratoconjunctivitis, chronic herpetic keratitis, ulcerative keratitis, traumatic corneal damage, sequestration of the cornea of cats, chronic keratitis, complicating the course of glaucoma. The characteristics of the OCT scans are givencorneas of cats and dogs that do not have corneal pathologies. OCT scans of various corneal pathologies in dogs and cats with a description of the revealed pathological changes are presented. Of great clinical interest are the data obtained during OCT of the cornea of animals undergoing keratoplasty operations using various forms of grafts. Conclusions. OCT makes it possible to assess the thickness and pathological structural changes of the corneal surface epithelium, corneal stroma and descemet membrane. We can measure them, determine the exact localization, and record pathological changes. Clinical observation of the dynamics of the pathological process in the cornea using OCT makes it possible to evaluate the effectiveness of drug treatment. In case of negative dynamics of corneal disease, it is necessary to determine the indications for surgical treatment (to assess the thickness of the cornea, the localization of its thinning zones, to characterize the depth and area of pathological changes). According to the OCT of the cornea, it is possible to choose the optimal surgical treatment for the patient, the technique and depth of optically constructive surgery (penetrating or anterior lamellar keratoplasty).; determine the depth and diameter of the planned microsurgical trepanation of corneal tissue, which will ensure good adaptation of the edges of the donor material.

Keywords: optical coherence tomography, corneal sequestration, optical coherence tomography of the cornea, corneal transplantation, cat, dog

Procedia PDF Downloads 37

Authors: Aleksandr S. Demin, Anastasiia V. Ivanova

Abstract:

Purpose: The current economy tends to increase the influence of digital technologies and diminish the human role in management. However, it is impossible to deny that a person still leads a business with its own set of values and priorities. The article presented aims to incorporate the peculiarities of the national culture and the characteristics of the supply chain using the quantitative values of the national culture obtained by the scholars of comparative management (Hofstede, House, and others). Design/Methodology/Approach: The conducted research is based on the secondary data in the field of cross-country comparison achieved by Prof. Hofstede and received in the GLOBE project. The data mentioned are used to design different aspects of the supply chain both on the cross-functional and inter-organizational levels. The connection between a range of principles in general (roles assignment, customer service prioritization, coordination of supply chain partners) and in comparative management (acknowledgment of the national peculiarities of the country in which the company operates) is shown over economic and mathematical models, mainly linear programming models. Findings: The combination of the team management wheel concept, the business processes of the global supply chain, and the national culture characteristics let a transnational corporation to form a supply chain crew balanced in costs, functions, and personality. To elaborate on an effective customer service policy and logistics strategy in goods and services distribution in the country under review, two approaches are offered. The first approach relies exceptionally on the customer’s interest in the place of operation, while the second one takes into account the position of the transnational corporation and its previous experience in order to accord both organizational and national cultures. The effect of integration practice on the achievement of a specific supply chain goal in a specific location is advised to assess via types of correlation (positive, negative, non) and the value of national culture indices. Research Limitations: The models developed are intended to be used by transnational companies and business forms located in several nationally different areas. Some of the inputs to illustrate the application of the methods offered are simulated. That is why the numerical measurements should be used with caution. Practical Implications: The research can be of great interest for the supply chain managers who are responsible for the engineering of global supply chains in a transnational corporation and the further activities in doing business on the international area. As well, the methods, tools, and approaches suggested can be used by top managers searching for new ways of competitiveness and can be suitable for all staff members who are keen on the national culture traits topic. Originality/Value: The elaborated methods of decision-making with regard to the national environment suggest the mathematical and economic base to find a comprehensive solution.

Keywords: logistics integration, logistics services, multinational corporation, national culture, team management, service policy, supply chain management

Procedia PDF Downloads 83

Authors: H. Weigelt-Marom

Abstract:

Over the years and up to the arousal of the COVID-19 pandemic, deaf or hard of hearing students studying in higher education institutions, participated lectures on campus using hearing aids and strategies adapted for frontal learning in a classroom. Usually, these aids were well known to them from their earlier study experience in school. However, the transition to online lessons, due to the latest pandemic, led deaf or hard of hearing students to study outside of their physical, well known learning environment. The change of learning environment and structure rose new challenges for these students. The present study examined the learning experience, limitations, challenges and benefits regarding learning online with lecture and classmates via the “Zoom” video conference program, among deaf or hard of hearing students in academia setting. In addition, emotional and social aspects related to learning in general versus the “Zoom” were examined. The study included 18 students diagnosed as deaf or hard of hearing, studying in various higher education institutions in Israel. All students had experienced lessons on the “Zoom”. Following allocation of the group study by the deaf and hard of hearing non-profit organization “Ma’agalei Shema”, and receiving the participants inform of consent, students were requested to answer a google form questioner and participate in an interview. The questioner included background information (e.g., age, year of studying, faculty etc.), level of computer literacy, and level of hearing and forms of communication (e.g., lip reading, sign language etc.). The interviews included a one on one, semi-structured, in-depth interview, conducted by the main researcher of the study (interview duration: up to 60 minutes). The interviews were held on “ZOOM” using specific adaptations for each interviewee: clear face screen of the interviewer for lip and face reading, and/ or professional sign language or live text transcript of the conversation. Additionally, interviewees used their audio devices if needed. Questions regarded: learning experience, difficulties and advantages studying using “Zoom”, learning in a classroom versus on “Zoom”, and questions concerning emotional and social aspects related to learning. Thematic analysis of the interviews revealed severe difficulties regarding the ability of deaf or hard of hearing students to comprehend during ”Zoom“ lessons without adoptive aids. For example, interviewees indicated difficulties understanding “Zoom” lessons due to their inability to use hearing devices commonly used by them in the classroom (e.g., FM systems). 80% indicated that they could not comprehend “Zoom” lessons since they could not see the lectures face, either because lectures did not agree to open their cameras or, either because they did not keep a straight forward clear face appearance while teaching. However, not all descriptions regarded learning via the “zoom” were negative. For example, 20% reported the recording of “Zoom” lessons as a main advantage. Enabling then to repeatedly watch the lessons at their own pace, mostly assisted by friends and family to translate the audio output into an accessible input. These finding and others regarding the learning experience of the group study on the “Zoom”, as well as their recommendation to enable deaf or hard of hearing students to study inclusively online, will be presented at the conference.

Keywords: deaf or hard of hearing, learning experience, Zoom, qualitative research

Procedia PDF Downloads 92

Authors: Debasish Nandy

Abstract:

India’s foreign policy towards all of her neighbor countries is determinate on the basis of multi-dimensional factors. India’s relations with its South Asian neighbor can be classified into three categories. In the first category, there are four countries -Sri Lanka, Bangladesh, Nepal, and Afghanistan- whose bilateral relationships have encompassed cooperation, irritants, problems and crisis at different points in time. With Pakistan, the relationship has been perpetually adversarial. The third category includes Bhutan and Maldives whose relations are marked by friendship and cooperation, free of any bilateral problems. It is needless to say that Jawaharlal Nehru emphasized on friendly relations with the neighboring countries. The subsequent Prime Ministers of India especially I.K. Gujral had advocated in making of peaceful and friendly relations with the subcontinental countries. He had given a unique idea to foster bilateral relations with the neighbors. His idea is known as ‘Gujral Doctrine’. A dramatical change has been witnessed in Indian foreign policy since 1991.In the post-Cold War period, India’s national security has been vehemently threatened by terrorism, which originated from Pakistan-Afghanistan and partly Bangladesh. India has required a cooperative security, which can be made by mutual understanding among the South Asian countries. Additionally, the countries of South Asia need to evolve the concept of ‘Cooperative Security’ to explain the underlying logic of regional cooperation. According to C. Rajamohan, ‘cooperative security could be understood, as policies of governments, which see themselves as former adversaries or potential adversaries to shift from or avoid confrontationist policies.’ A cooperative security essentially reflects a policy of dealing peacefully with conflicts, not merely by abstention from violence or threats but by active engagement in negotiation, a search for practical solutions and with a commitment to preventive measures. Cooperative assumes the existence of a condition in which the two sides possess the military capabilities to harm each other. Establishing cooperative security runs into a complex process building confidence. South Asian nations often engaged with hostility to each other. Extra-regional powers have been influencing their powers in this region since a long time. South Asian nations are busy to purchase military equipment. In spite of weakened economic systems, these states are spending a huge amount of money for their security. India is the big power in this region in every aspect. The big states- small states syndrome is a negative factor in this respect. However, India will have to an initiative to extended ‘track II diplomacy’ or soft diplomacy for its security as well as the security of this region.Confidence building measures could help rejuvenate not only SAARC but also build trust and mutual confidence between India and its neighbors in South Asia. In this paper, I will focus on different aspects of India’s policy towards it, South-Asian neighbors. It will also be searched that how India is dealing with these countries by using a mixed type of diplomacy – both idealistic and realistic points of view. Security and cooperation are two major determinants of India’s foreign policy towards its South Asian neighbors.

Keywords: bilateral, diplomacy, infiltration, terrorism

Procedia PDF Downloads 519

Authors: Maximilian Engelhardt, Stephan Seeck

Abstract:

The COVID-19 pandemic is accelerating the already growing field of e-commerce. The resulting urban freight transport volume leads to traffic and negative environmental impact. Furthermore, the service level of parcel logistics service provider is lacking far behind the expectations of consumer. These challenges can be solved by radically reorganize the urban last mile distribution structure: parcels could be consolidated in a micro hub within the inner city and delivered within time windows by cargo bike. This approach leads to a significant improvement of consumer satisfaction with their overall delivery experience. However, this approach also leads to significantly increased costs per parcel. While there is a relevant share of online shoppers that are willing to pay for such a delivery service there are no deeper insights about this target group available in the literature. Being aware of the importance of knowing target groups for businesses, the aim of this paper is to elaborate the most important factors that determine the willingness to pay for sustainable and service-oriented parcel delivery (factor analysis) and to derive customer segments (cluster analysis). In order to answer those questions, a data set is analyzed using quantitative methods of multivariate statistics. The data set was generated via an online survey in September and October 2020 within the five largest cities in Germany (n = 1.071). The data set contains socio-demographic, living-related and value-related variables, e.g. age, income, city, living situation and willingness to pay. In a prior work of the author, the data was analyzed applying descriptive and inference statistical methods that only provided limited insights regarding the above-mentioned research questions. The analysis in an exploratory way using factor and cluster analysis promise deeper insights of relevant influencing factors and segments for user behavior of the mentioned parcel delivery concept. The analysis model is built and implemented with help of the statistical software language R. The data analysis is currently performed and will be completed in December 2021. It is expected that the results will show the most relevant factors that are determining user behavior of sustainable and service-oriented parcel deliveries (e.g. age, current service experience, willingness to pay) and give deeper insights in characteristics that describe the segments that are more or less willing to pay for a better parcel delivery service. Based on the expected results, relevant implications and conclusions can be derived for startups that are about to change the way parcels are delivered: more customer-orientated by time window-delivery and parcel consolidation, more environmental-friendly by cargo bike. The results will give detailed insights regarding their target groups of parcel recipients. Further research can be conducted by exploring alternative revenue models (beyond the parcel recipient) that could compensate the additional costs, e.g. online-shops that increase their service-level or municipalities that reduce traffic on their streets.

Keywords: customer segmentation, e-commerce, last mile delivery, parcel service, urban logistics, willingness-to-pay

Procedia PDF Downloads 84

Authors: Sandra Carrillo Hoyos

Abstract:

Mining activities in South America have significantly grown during the last decades, given the abundance of natural resources, the implemented governmental policies to incentivize foreign investment as well as the boom in international prices for metals and oil between 2002 and 2008. While this context allowed the region to occupy a leading position between the top producers of minerals around the world, it has also meant an increase in socio-environmental conflicts which have generated costs and negative impacts not only for the companies but especially for the governments and local communities.During the latest decade, the mining sector in Peru has faced with the social resistance of a large number of communities, which began organizing actions against the implementation of high investing projects. The dissatisfaction has derived in the prevalence of socio-environmental conflicts associated with mining activities, some of them never solved into an agreement. In order to prevent those socio-environmental conflicts and obtain the social license from local communities, most of the mining companies have developed diverse initiatives within the framework of policies and practices of corporate social responsibility (CSR). This paper has assessed the mining sector’s contribution toward the local development management along the last decade, as part of CSR strategies as well as the policies promoted by the Peruvian State. This assessment found that, in the beginning, these initiatives have been based on a philanthropic approach and were reacting to pressures from local stakeholders to maintain the consent to operate from the surrounding communities as well as to create, as a result, a harmonious atmosphere for operations. Due to the weak State presence, such practices have increased the expectations of communities related to the participation of mining companies in solving structural development problems, especially those related to primary needs, infrastructure, education, health, among others. In other words, this paper was focused on analyze in what extent these initiatives have promoted local empowerment for development planning and integrated management of natural resources from a territorial approach. From this perspective, the analysis demonstrates that, while the design and planning of social investment initiatives have improved due to the sector´s sustainability approach, many companies have developed actions beyond their competence during this process. In some cases, the referenced actions have generated dependency with communities, even though this relationship has not exempted the companies of conflict situations with unfortunate consequences. Furthermore, the social programs developed have not necessarily generated a significant impact in improving the quality of life of affected populations. In fact, it is possible to identify that those regions with high mining resources and investment are facing with a situation of poverty and high dependency on mining production. In spite of the revenues derived from mining industry, local governments have not been able to translate the royalties into sustainable development opportunities. For this reason, the proposed paper suggests some challenges for the mining sector contribution to local development based on the best practices and lessons learnt from a benchmarking for the leading mining companies.

Keywords: corporate social responsibility, local development, mining, socio-environmental conflict

Procedia PDF Downloads 370

Authors: Isabel Latz, Mark Lusk, Josiah Heyman

Abstract:

The rise of restrictive U.S. immigration policies and their strengthened enforcement has reportedly caused concerns among providers about their inadvertent effects on service utilization among Latinx and immigrant communities. This study presents perceptions on this issue from twenty service providers in health care, mental health, nutrition assistance, legal assistance, and immigrant advocacy in El Paso, Texas. All participants were experienced professionals, with fifteen in CEO, COO, executive director, or equivalent positions, and based at organizations that provide services for immigrant and/or low-income populations in a bi-national border community. Quantitative and qualitative data were collected by two primary investigators via semi-structured telephone interviews with an average length of 20 minutes. A survey script with closed and open-ended questions inquired about participants’ demographic information and perceptions of impacts of immigration enforcement policies under the current federal administration on their work and patient or client populations. Quantitative and qualitative data were analyzed to produce descriptive statistics and identify salient themes, respectively. Nearly all respondents stated that their work has been negatively (N=13) or both positively and negatively (N=5) affected by current immigration enforcement policies. Negative effects were most commonly related to immigration enforcement-related fear and uncertainty among patient or client populations. Positive effects most frequently referred to a sense of increased community organizing and greater cooperation among organizations. Similarly, the majority of service providers either reported an increase (N=8) or decrease (N=6) in service utilization due to changes in immigration enforcement policies. Increased service needs were primarily related to a need for public education about immigration enforcement policy changes, information about how new policies impact individuals’ service eligibility, legal status, and civil rights, as well as a need to correct misinformation. Decreased service utilization was primarily related to fear-related service avoidance. While providers observed changes in service utilization among undocumented immigrants and mixed-immigration status families, in particular, participants also noted ‘spillover’ effects on the larger Latinx community, including legal permanent and temporary residents, refugees or asylum seekers, and U.S. citizens. This study reveals preliminary insights into providers’ widespread concerns about the effects of current immigration enforcement policies on health, social, and legal service utilization among Latinx individuals. Further research is necessary to comprehensively assess impacts of immigration enforcement policies on service utilization in Latinx and immigrant communities. This information is critical to address gaps in service utilization and prevent an exacerbation of health disparities among Latinx, immigrant, and border populations. In a global climate of rising nationalism and xenophobia, it is critical for policymakers to be aware of the consequences of immigration enforcement policies on the utilization of essential services to protect the well-being of minority and immigrant communities.

Keywords: immigration enforcement, immigration policy, provider perceptions, service utilization

Procedia PDF Downloads 115

Authors: Shyamani Hettiarachchi, Thilini Lokubalasuriya, Shakeela Saleem, Dinusha Nonis, Isuru Dharmaratne, Lakshika Udugama

Abstract:

Introduction: Late identification of language difficulties in children could result in long-term negative consequences for communication, literacy and self-esteem. This highlights the need for early identification and intervention for speech, language and communication difficulties. Speech and language therapy is a relatively new profession in Sri Lanka and at present, there are no formal standardized screening tools to assess language skills in Sinhala-speaking children. The development and validation of a short, accurate screening tool to enable the identification of children with syntactic difficulties in Sinhala is a current need. Aims: 1) To develop test items for a Sinhala Syntactic Structures (S3 Short Form) test on children aged between 3;0 to 5;0 years 2) To validate the test of Sinhala Syntactic Structures (S3 Short Form) on children aged between 3; 0 to 5; 0 years Methods: The Sinhala Syntactic Structures (S3 Short Form) was devised based on the Renfrew Action Picture Test. As Sinhala contains post-positions in contrast to English, the principles of the Renfrew Action Picture Test were followed to gain an information score and a grammar score but the test devised reflected the linguistic-specificity and complexity of Sinhala and the pictures were in keeping with the culture of the country. This included the dative case marker ‘to give something to her’ (/ejɑ:ʈə/ meaning ‘to her’), the instrumental case marker ‘to get something from’ (/ejɑ:gən/ meaning ‘from him’ or /gɑhən/ meaning ‘from the tree’), possessive noun (/ɑmmɑge:/ meaning ‘mother’s’ or /gɑhe:/ meaning ‘of the tree’ or /male:/ meaning ‘of the flower’) and plural markers (/bɑllɑ:/ bɑllo:/ meaning ‘dog/dogs’, /mɑlə/mɑl/ meaning ‘flower/flowers’, /gɑsə/gɑs/ meaning ‘tree/trees’ and /wɑlɑ:kulə/wɑlɑ:kulu/ meaning ‘cloud/clouds’). The picture targets included socio-culturally appropriate scenes of the Sri Lankan New Year celebration, elephant procession and the Buddhist ‘Wesak’ ceremony. The test was piloted with a group of 60 participants and necessary changes made. In phase 1, the test was administered to 100 Sinhala-speaking children aged between 3; 0 and 5; 0 years in one district. In this presentation on phase 2, the test was administered to another 100 Sinhala-speaking children aged between 3; 0 to 5; 0 in three districts. In phase 2, the selection of the test items was assessed via measures of content validity, test-retest reliability and inter-rater reliability. The age of acquisition of each syntactic structure was determined using content and grammar scores which were statistically analysed using t-tests and one-way ANOVAs. Results: High percentage agreement was found on test-retest reliability on content validity and Pearson correlation measures and on inter-rater reliability. As predicted, there was a statistically significant influence of age on the production of syntactic structures at p<0.05. Conclusions: As the target test items included generated the information and the syntactic structures expected, the test could be used as a quick syntactic screening tool with preschool children.

Keywords: Sinhala, screening, syntax, language

Procedia PDF Downloads 319

Authors: Monika Soni, Shovonlal Bhowmick, Chandra Bhattacharya, Jitendra Sharma, Prafulla Dutta, Jagadish Mahanta

Abstract:

Aedes aegypti and Aedes albopictus are considered as two major vectors to transmit dengue virus. In North-east India, two states viz. Assam and Arunachal Pradesh are known to be high endemic zone for dengue and Chikungunya viral infection. The taxonomical classification of medically important vectors are important for mapping of actual evolutionary trends and epidemiological studies. However, misidentification of mosquito species in field-collected mosquito specimens could have a negative impact which may affect vector-borne disease control policy. DNA barcoding is a prominent method to record available species, differentiate from new addition and change of population structure. In this study, a combined approach of a morphological and molecular technique of DNA barcoding was adopted to explore sequence variation in mitochondrial cytochrome c oxidase subunit I (COI) gene within dengue vectors. The study has revealed the map distribution of the dengue vector from two states i.e. Assam and Arunachal Pradesh, India. Approximate five hundred mosquito specimens were collected from different parts of two states, and their morphological features were compared with the taxonomic keys. The analysis of detailed taxonomic study revealed identification of two species Aedes aegypti and Aedes albopictus. The species aegypti comprised of 66.6% of the specimen and represented as dominant dengue vector species. The sequences obtained through standard DNA barcoding protocol were compared with public databases, viz. GenBank and BOLD. The sequences of all Aedes albopictus have shown 100% similarity whereas sequence of Aedes aegypti has shown 99.77 - 100% similarity of COI gene with that of different geographically located same species based on BOLD database search. From dengue prevalent different geographical regions fifty-nine sequences were retrieved from NCBI and BOLD databases of the same and related taxa to determine the evolutionary distance model based on the phylogenetic analysis. Neighbor-Joining (NJ) and Maximum Likelihood (ML) phylogenetic tree was constructed in MEGA6.06 software with 1000 bootstrap replicates using Kimura-2-Parameter model. Data were analyzed for sequence divergence and found that intraspecific divergence ranged from 0.0 to 2.0% and interspecific divergence ranged from 11.0 to 12.0%. The transitional and transversional substitutions were tested individually. The sequences were deposited in NCBI: GenBank database. This observation claimed the first DNA barcoding analysis of Aedes mosquitoes from North-eastern states in India and also confirmed the range expansion of two important mosquito species. Overall, this study insight into the molecular ecology of the dengue vectors from North-eastern India which will enhance the understanding to improve the existing entomological surveillance and vector incrimination program.

Keywords: COI, dengue vectors, DNA barcoding, molecular identification, North-east India, phylogenetics

Procedia PDF Downloads 270

Authors: Z. Yousefniayejahr, S. Bolognini, A. Bonini, C. Campobasso, N. Poma, F. Vivaldi, M. Di Luca, A. Tavanti, F. Di Francesco

Abstract:

Pathogenic bacteria represent a threat to healthcare systems and the food industry because their rapid detection remains challenging. Electrochemical biosensors are gaining prominence as a novel technology for the detection of pathogens due to intrinsic features such as low cost, rapid response time, and portability, which make them a valuable alternative to traditional methodologies. These sensors use biorecognition elements that are crucial for the identification of specific bacteria. In this context, bacteriophages are promising tools for their inherent high selectivity towards bacterial hosts, which is of fundamental importance when detecting bacterial pathogens in complex biological samples. In this study, we present the development of a low-cost and portable sensor based on the Zeno phage for the rapid detection of Staphylococcus aureus. Screen-printed gold electrodes functionalized with the Zeno phage were used, and electrochemical impedance spectroscopy was applied to evaluate the change of the charge transfer resistance (Rct) as a result of the interaction with S. aureus MRSA ATCC 43300. The phage-based biosensor showed a linear range from 101 to 104 CFU/mL with a 20-minute response time and a limit of detection (LOD) of 1.2 CFU/mL under physiological conditions. The biosensor’s ability to recognize various strains of staphylococci was also successfully demonstrated in the presence of clinical isolates collected from different geographic areas. Assays using S. epidermidis were also carried out to verify the species-specificity of the phage sensor. We only observed a remarkable change of the Rct in the presence of the target S. aureus bacteria, while no substantial binding to S. epidermidis occurred. This confirmed that the Zeno phage sensor only targets S. aureus species within the genus Staphylococcus. In addition, the biosensor's specificity with respect to other bacterial species, including gram-positive bacteria like Enterococcus faecium and the gram-negative bacterium Pseudomonas aeruginosa, was evaluated, and a non-significant impedimetric signal was observed. Notably, the biosensor successfully identified S. aureus bacterial cells in a complex matrix such as a nasal swab, opening the possibility of its use in a real-case scenario. We diluted different concentrations of S. aureus from 108 to 100 CFU/mL with a ratio of 1:10 in the nasal swap matrices collected from healthy donors. Three different sensors were applied to measure various concentrations of bacteria. Our sensor indicated high selectivity to detect S. aureus in biological matrices compared to time-consuming traditional methods, such as enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and radioimmunoassay (RIA), etc. With the aim to study the possibility to use this biosensor to address the challenge associated to pathogen detection, ongoing research is focused on the assessment of the biosensor’s analytical performances in different biological samples and the discovery of new phage bioreceptors.

Keywords: electrochemical impedance spectroscopy, bacteriophage, biosensor, Staphylococcus aureus

Procedia PDF Downloads 29

Authors: Mikyung Bak

Abstract:

The dokkaebi, a beloved icon of Korean culture, is represented as an elf, goblin, monster, dwarf, or any similar creature in different media, such as animated shows, comics, soap operas, and movies. It is often described as a mythical creature with a horn or horns and long teeth, wearing tiger-skin pants or a grass skirt, and carrying a magic stick. Many Korean researchers agree on the similarity of the image of the Korean dokkaebi with that of the Japanese oni, a view that is regard as negative from an anti-colonial or nationalistic standpoint. They cite such similarity between the two mythical creatures as evidence that Japanese colonialism persists in Korea. The debate on the originality of dokkaebi’s visual representation is an issue that must be addressed urgently. This research demonstrates through a diagram the plurality of interpretations of dokkaebi’s visual representations in what are considered ‘authentic’ images of dokkaebi in Korean art and culture. This diagram presents the opinions of four major groups in the debate, namely, the scholars of Korean literature and folklore, art historians, authors, and artists. It also shows the creation of new dokkaebi visual representations in popular media, including those influenced by the debate. The diagram further proves that dokkaebi’s representations varied, which include the typical persons or invisible characters found in Korean literature, original Korean folk characters in traditional art, and even universal spirit characters. They are also visually represented by completely new creatures as well as oni-based mythical beings and the actual oni itself. The earlier dokkaebi representations were driven by the creation of a national ideology or national cultural paradigm and, thus, were more uniform and protected. In contrast, the more recent representations are influenced by the Korean industrial strategy of ‘cultural economics,’ which is concerned with the international rather than the domestic market. This recent Korean cultural strategy emphasizes diversity and commonality with the global culture rather than originality and locality. It employs traditional cultural resources to construct a global image. Consequently, dokkaebi’s recent representations have become more common and diverse, thereby incorporating even oni’s characteristics. This argument has rendered the grounds of the debate irrelevant. The dokkaebi has been used recently for tourist marketing purposes, particularly in revitalizing interest in regions considered the cradle of various traditional dokkaebi tales. These campaign strategies include the Jeju-do Dokkaebi Park, Koksung Dokkaebi Land, as well as the Taebaek and Sokri-san Dokkaebi Festivals. Almost dokkaebi characters are identical to the Japanese oni in tourist marketing. However, the pursuit for dokkaebi’s authentic visual representation is less interesting and fruitful than the appreciation of the entire spectrum of dokkaebi images that have been created. Thus, scholars and stakeholders must not exclude the possibilities for a variety of potentials within the visual culture. The same sentiment applies to traditional art and craft. This study aims to contribute to a new visualization of the dokkaebi that embraces the possibilities of both folk craft and art, which continue to be uncovered by diverse and careful researchers in a still-developing field.

Keywords: Dokkaebi, post-colonial period, representation, tourist marketing

Procedia PDF Downloads 249

Authors: Tavee Cheausuwantavee

Abstract:

: COVID-19 pandemic significantly has impacted everyone’s life. Persons with disabilities (PWDs) in Thailand have been also effected by COVID-19 situation in many aspects of their lives, while there have been no more appropriate services of the government and providers. Research projects had been only focused on health precaution and protection. Rapid need assessments on populations and vulnerable groups were limited and conducted via social media and an online survey. However, little is known about the real problems and needs of Thai PWDs during the COVID-19 pandemic for an effective plan and integral services for those PWDs. Therefore, this study aims to explore the diverse problems and needs of Thai PWDs in the COVID -19 pandemic. Results from the study can be used by the government and other stakeholders for further effective services. Methods: This study was used a mixed-method design that consisted of both quantitative and qualitative measures. In terms of the quantitative approach, there were 744 PWDs and caregivers of all types of PWDs selected by proportional multistage stratified random sampling according to their disability classification and geographic location. Questionnaires with 59 items regarding participant characteristics, problems, and needs in health, education, employment, and other social inclusion, were distributed to all participants and some caregivers completed questionnaires when PWDs were not able to due to limited communication and/or literacy skills. Completed questionnaires were analyzed by descriptive statistics. For qualitative design, 62 key informants who were PWDs or caregivers were selected by purposive sampling. Ten focus groups, each consisting of 5-6 participants and 7 in-depth interviews from all the groups identified above, were conducted by researchers across five regions. Focus group and in-depth interview guidelines with 6 items regarding problems and needs in health, education, employment, other social inclusion, and their coping during COVID -19 pandemic. Data were analyzed using a modification of thematic content analysis. Results: Both quantitative and qualitative studies showed that PWDs and their caregivers had significant problems and needs all aspects of their life, including income and employment opportunity, daily living and social inclusion, health, and education, respectively. These problems and needs were related to each other, forming a vicious cycle. Participants also learned from negative pandemic to more positive life aspects, including their health protection, financial plan, family cohesion, and virtual technology literacy and innovation. Conclusion and implications: There have been challenges facing all life aspects of PWDs in Thailand during the COVID -19 pandemic, particularly incomes and daily living. All challenges have been the vicious cycle and complicated. There have been also a positive lesson learned of participants from the pandemic. Recommendations for government and stakeholders in the COVID-19 pandemic for PWDs are the following. First, the health protection strategy and policy of PWDs should be promoted together with other quality of life development including income generation, education and social inclusion. Second, virtual technology and alternative innovation should be enhanced for proactive service providers. Third, accessible information during the pandemic for all PWDs must be concerned. Forth, lesson learned from the pandemic should be shared and disseminated for crisis preparation and a positive mindset in the disruptive world.

Keywords: challenge, COVID-19, disability, Thailand

Procedia PDF Downloads 55

Authors: Harriet Koshie Lamptey, Richard Boateng

Abstract:

Mobile learning (m-learning) is a novel approach to knowledge acquisition and dissemination and is gaining global attention. Steady progress in wireless technologies and the portability of communication devices continue to broaden the scope and use of mobiles. With the convergence of Web functionality onto mobile platforms and the affordability and availability of mobile technology, m-learning has the potential of being the next prevalent channel of education in both formal and informal settings. There is substantive literature on developed countries but the state in developing countries (DCs) however appears vague. This paper is a synthesis of extant literature on mobile learning in DCs. The research interest is based on the fact that in DCs, mobile communication and internet connectivity are popular. However, its use in education is under explored. There are some reviews on the state, conceptualizations, trends and teacher education, but to the authors’ knowledge, no study has focused on mobile learning adoption and integration issues. This study examines issues and gaps associated with its adoption and integration in DCs higher education institutions. A qualitative build-up of literature was conducted using articles pooled from electronic databases (Google Scholar and ERIC). To enable criteria for inclusion and incorporate diverse study perspectives, search terms used were m-learning, DCs, higher education institutions, challenges, benefits, impact, gaps and issues. The synthesis revealed that though mobile technology has diffused globally, its pedagogical pursuit in DCs remains quite low. The absence of a mobile Web and the difficulty of resource conversion into mobile format due to lack of funding and technical competence is a stumbling block. Again, the lack of established design and implementation rules to guide the development of m-learning platforms in DCs is a hindrance. The absence of access restrictions on devices poses security threats to institutional systems. Negative perceptions that devices are taking over faculty roles lead to resistance in some situations. Resistance to change can be a hindrance to the acceptance and success of new systems. Lack of interest for m-learning is also attributed to lower technological literacy levels of the underprivileged masses. Scholarly works on m-learning in DCs is yet to mature. Most technological innovations are handed down from developed countries, and this constantly creates a lag for DCs. Lack of theoretical grounding was also identified which reduces the objectivity of study reports. The socio-cultural terrain of DCs results in societies with different views and needs that have been identified as a hindrance to research. Institutional commitment decisions, adequate funding for the necessary infrastructural development as well as multiple stakeholder participation is important for project success. Evidence suggests that while adoption decisions are readily made, successful integration of the concept for its full benefits to be realized is often neglected. Recommendations to findings were made to provide possible remedies to identified issues.

Keywords: developing countries, higher education institutions, mobile learning, literature review

Procedia PDF Downloads 203

Authors: Andreas Stollwitzer, Lara Bettinelli, Josef Fink

Abstract:

The expansion of the high-speed rail network over the past decades has resulted in new challenges for engineers, including traffic-induced resonance vibrations of railway bridges. Excessive resonance-induced speed-dependent accelerations of railway bridges during high-speed traffic can lead to negative consequences such as fatigue symptoms, distortion of the track, destabilisation of the ballast bed, and potentially even derailment. A realistic prognosis of bridge vibrations during high-speed traffic must not only rely on the right choice of an adequate calculation model for both bridge and train but first and foremost on the use of dynamic model parameters which reflect reality appropriately. However, comparisons between measured and calculated bridge vibrations are often characterised by considerable discrepancies, whereas dynamic calculations overestimate the actual responses and therefore lead to uneconomical results. This gap between measurement and calculation constitutes a complex research issue and can be traced to several causes. One major cause is found in the dynamic properties of the ballasted track, more specifically in the persisting, substantial uncertainties regarding the consideration of the ballasted track (mechanical model and input parameters) in dynamic calculations. Furthermore, the discrepancy is particularly pronounced concerning the damping values of the bridge, as conservative values have to be used in the calculations due to normative specifications and lack of knowledge. By using a large-scale test facility, the analysis of the dynamic behaviour of ballasted track has been a major research topic at the Institute of Structural Engineering/Steel Construction at TU Wien in recent years. This highly specialised test facility is designed for isolated research of the ballasted track's dynamic stiffness and damping properties – independent of the bearing structure. Several mechanical models for the ballasted track consisting of one or more continuous spring-damper elements were developed based on the knowledge gained. These mechanical models can subsequently be integrated into bridge models for dynamic calculations. Furthermore, based on measurements at the test facility, model-dependent stiffness and damping parameters were determined for these mechanical models. As a result, realistic mechanical models of the railway bridge with different levels of detail and sufficiently precise characteristic values are available for bridge engineers. Besides that, this contribution also presents another practical application of such a bridge model: Based on the bridge model, determination equations for the damping factor (as Lehr's damping factor) can be derived. This approach constitutes a first-time method that makes the damping factor of a railway bridge calculable. A comparison of this mathematical approach with measured dynamic parameters of existing railway bridges illustrates, on the one hand, the apparent deviation between normatively prescribed and in-situ measured damping factors. On the other hand, it is also shown that a new approach, which makes it possible to calculate the damping factor, provides results that are close to reality and thus raises potentials for minimising the discrepancy between measurement and calculation.

Keywords: ballasted track, bridge dynamics, damping, model design, railway bridges

Procedia PDF Downloads 142

Authors: Vangmayee. V. Subban, Somashekara H. S, Shwetha Prabhu, Jayashree S. Bhat

Abstract:

Introduction and Need: Phonological processing is critical in learning to read alphabetical and non-alphabetical languages. However, its role in learning to read Kannada an alphasyllabary is equivocal. The literature has focused on the developmental role of phonological awareness on reading. To the best of authors knowledge, the role of phonological memory and phonological naming has not been addressed in alphasyllabary Kannada language. Therefore, there is a need to evaluate the comprehensive role of the phonological processing skills in Kannada on word decoding skills during the early years of schooling. Aim and Objectives: The present study aimed to explore the phonological processing abilities and their role in learning to decode pseudowords in children learning to read the Kannada language during initial years of formal schooling between 5.6 to 8.6 years. Method: In this cross sectional study, 60 typically developing Kannada speaking children, 20 each from Grade I, Grade II, and Grade III between the age range of 5.6 to 6.6 years, 6.7 to 7.6 years and 7.7 to 8.6 years respectively were selected from Kannada medium schools. Phonological processing abilities were assessed using an assessment tool specifically developed to address the objectives of the present research. The assessment tool was content validated by subject experts and had good inter and intra-subject reliability. Phonological awareness was assessed at syllable level using syllable segmentation, blending, and syllable stripping at initial, medial and final position. Phonological memory was assessed using pseudoword repetition task and phonological naming was assessed using rapid automatized naming of objects. Both phonological awareneness and phonological memory measures were scored for the accuracy of the response, whereas Rapid Automatized Naming (RAN) was scored for total naming speed. Results: The mean scores comparison using one-way ANOVA revealed a significant difference (p ≤ 0.05) between the groups on all the measures of phonological awareness, pseudoword repetition, rapid automatized naming, and pseudoword reading. Subsequent post-hoc grade wise comparison using Bonferroni test revealed significant differences (p ≤ 0.05) between each of the grades for all the tasks except (p ≥ 0.05) for syllable blending, syllable stripping, and pseudoword repetition between Grade II and Grade III. The Pearson correlations revealed a highly significant positive correlation (p=0.000) between all the variables except phonological naming which had significant negative correlations. However, the correlation co-efficient was higher for phonological awareness measures compared to others. Hence, phonological awareness was chosen a first independent variable to enter in the hierarchical regression equation followed by rapid automatized naming and finally, pseudoword repetition. The regression analysis revealed syllable awareness as a single most significant predictor of pseudoword reading by explaining the unique variance of 74% and there was no significant change in R² when RAN and pseudoword repetition were added subsequently to the regression equation. Conclusion: Present study concluded that syllable awareness matures completely by Grade II, whereas the phonological memory and phonological naming continue to develop beyond Grade III. Amongst phonological processing skills, phonological awareness, especially syllable awareness is crucial for word decoding than phonological memory and naming during initial years of schooling.

Keywords: phonological awareness, phonological memory, phonological naming, phonological processing, pseudo-word decoding

Procedia PDF Downloads 144

Authors: Mehdi Soula, Yosra Mani, Estelle Saras, Antoine Drapeau, Raoudha Grami, Mahjoub Aouni, Jean-Yves Madec, Marisa Haenni, Wejdene Mansour

Abstract:

Multi-resistance to antibiotics in gram-negative bacilli and particularly in enterobacteriaceae, has become frequent in hospitals in Tunisia. However, data on antibiotic resistant bacteria in aquatic products are scarce. The aims of this study are to estimate the proportion of ESBL- and carbapenemase-producing Enterobacterales in seafood (clams and fish) in Tunisia and to molecularly characterize the collected isolates. Two types of seafood were sampled in unrelated markets in four different regions in Tunisia (641 pieces of farmed fish and 1075 mediterranean clams divided into 215 pools, and each pool contained 5 pieces). Once purchased, all samples were incubated in tubes containing peptone salt broth for 24 to 48h at 37°C. After incubation, overnight cultures were isolated on selective MacConkey agar plates supplemented with either imipenem or cefotaxime, identified using API20E test strips (bioMérieux, Marcy-l’Étoile, France) and confirmed by Maldi-TOF MS. Antimicrobial susceptibility was determined by the disk diffusion method on Mueller-Hinton agar plates and results were interpreted according to CA-SFM 2021. ESBL-producing Enterobacterales were detected using the Double Disc Synergy Test (DDST). Carbapenem-resistance was detected using an ertapenem disk and was respectively confirmed using the ROSCO KPC/MBL and OXA-48 Confirm Kit (ROSCO Diagnostica, Taastrup, Denmark). DNA was extracted using a NucleoSpin Microbial DNA extraction kit (Macherey-Nagel, Hoerdt, France), according to the manufacturer’s instructions. Resistance genes were determined using the CGE online tools. The replicon content and plasmid formula were identified from the WGS data using PlasmidFinder 2.0.1 and pMLST 2.0. From farmed fishes, nine ESBL-producing strains (9/641, 1.4%) were isolated, which were identified as E. coli (n=6) and K. pneumoniae (n=3). Among the 215 pools of 5 clams analyzed, 18 ESBL-producing isolates were identified, including 14 E. coli and 4 K. pneumoniae. A low isolation rate of ESBL-producing Enterobacterales was detected 1.6% (18/1075) in clam pools. In fish, the ESBL phenotype was due to the presence of the blaCTX-M-15 gene in all nine isolates, but no carbapenemase gene was identified. In clams, the predominant ESBL phenotype was blaCTX-M-1 (n=6/18). blaCPE (NDM1, OXA48) was detected only in 3 isolates ‘K. pneumoniae isolates’. Replicon typing on the strains carring the ESBL and carbapenemase gene revelead that the major type plasmid carried ESBL were IncF (42.3%) [n=11/26]. In all, our results suggest that seafood can be a reservoir of multi-drug resistant bacteria, most probably of human origin but also by the selection pressure of antibiotic. Our findings raise concerns that seafood bought for consumption may serve as potential reservoirs of AMR genes and pose serious threat to public health.

Keywords: BLSE, carbapenemase, enterobacterales, tunisian seafood

Procedia PDF Downloads 76

Authors: Lilah Inzelberg, David Rand, Stanislav Steinberg, Moshe David Pur, Yael Hanein

Abstract:

Human facial expressions carry important psychological and neurological information. Facial expressions involve the co-activation of diverse muscles. They depend strongly on personal affective interpretation and on social context and vary between spontaneous and voluntary activations. Smiling, as a special case, is among the most complex facial emotional expressions, involving no fewer than 7 different unilateral muscles. Despite their ubiquitous nature, smiles remain an elusive and debated topic. Smiles are associated with happiness and greeting on one hand and anger or disgust-masking on the other. Accordingly, while high-resolution recording of muscle activation patterns, in a non-interfering setting, offers exciting opportunities, it remains an unmet challenge, as contemporary surface facial electromyography (EMG) methodologies are cumbersome, restricted to the laboratory settings, and are limited in time and resolution. Here we present a wearable and non-invasive method for objective mapping of facial muscle activation and demonstrate its application in a natural setting. The technology is based on a recently developed dry and soft electrode array, specially designed for surface facial EMG technique. Eighteen healthy volunteers (31.58 ± 3.41 years, 13 females), participated in the study. Surface EMG arrays were adhered to participant left and right cheeks. Participants were instructed to imitate three facial expressions: closing the eyes, wrinkling the nose and smiling voluntary and to watch a funny video while their EMG signal is recorded. We focused on muscles associated with 'enjoyment', 'social' and 'masked' smiles; three categories with distinct social meanings. We developed a customized independent component analysis algorithm to construct the desired facial musculature mapping. First, identification of the Orbicularis oculi and the Levator labii superioris muscles was demonstrated from voluntary expressions. Second, recordings of voluntary and spontaneous smiles were used to locate the Zygomaticus major muscle activated in Duchenne and non-Duchenne smiles. Finally, recording with a wireless device in an unmodified natural work setting revealed expressions of neutral, positive and negative emotions in face-to-face interaction. The algorithm outlined here identifies the activation sources in a subject-specific manner, insensitive to electrode placement and anatomical diversity. Our high-resolution and cross-talk free mapping performances, along with excellent user convenience, open new opportunities for affective processing and objective evaluation of facial expressivity, objective psychological and neurological assessment as well as gaming, virtual reality, bio-feedback and brain-machine interface applications.

Keywords: affective expressions, affective processing, facial EMG, high-resolution electromyography, independent component analysis, wireless electrodes

Procedia PDF Downloads 220

Authors: Kenechukwu Ikebuaku

Abstract:

Entrepreneurship has long been offered as the panacea for poor economic growth and high rate of unemployment. Business incubation is considered an effective means for enhancing entrepreneurial actitivities while engendering socio-economic development. Information Technology Developers Entrepreneurship Accelerator (iDEA), is a software business incubation programme established by the Nigerian government as a means of boosting digital entrepreneurship activities and reducing unemployment in the country. This study assessed the contribution of iDEA Nigeria’s entrepreneurship programmes towards enhancing the capabilities of its tenants. Using the capability approach and the sustainable livelihoods approach, the study analysed iDEA programmes’ contribution towards the expansion of participants’ entrepreneurial capabilities. Apart from identifying a set of entrepreneurial capabilities from both the literature and empirical analysis, the study went further to ascertain how iDEA incubation has helped to enhance those capabilities for its tenants. It also examined digital entrepreneurship as a valued functioning and as an intermediate functioning leading to other valuable functioning. Furthermore, the study examined gender as a conversion factor in digital entrepreneurship. Both qualitative and quantitative research methods were used for the study, and measurement of key variables was made. While the entire population was utilised to collect data for the quantitative research, purposive sampling was used to select respondents for semi-structured interviews in the qualitative research. However, only 40 beneficiaries agreed to take part in the survey while 10 respondents were interviewed for the study. Responses collected from questionnaires administered were subjected to statistical analysis using SPSS. The study developed indexes to measure the perception of the respondents, on how iDEA programmes have enhanced their entrepreneurial capabilities. The Capabilities Enhancement Perception Index (CEPI) computed indicated that the respondents believed that iDEA programmes enhanced their entrepreneurial capabilities. While access to power supply and reliable internet have the highest positive deviations around mean, negotiation skills and access to customers/clients have the highest negative deviation. These were well supported by the findings of the qualitative analysis in which the participants unequivocally narrated how the resources provided by iDEA aid them in their entrepreneurial endeavours. It was also found that iDEA programmes have a significant effect on the tenants’ access to networking opportunities, both with other emerging entrepreneurs and established entrepreneurs. While assessing gender as a conversion factor, it was discovered that there was very low female participation within the digital entrepreneurship ecosystem. The root cause of this gender disparity was found in unquestioned cultural beliefs and social norms which relegate women to a subservient position and household duties. The findings also showed that many of the entrepreneurs could be considered opportunity-based entrepreneurs rather than necessity entrepreneurs, and that digital entrepreneurship is a valued functioning for iDEA tenants. With regards to challenges facing digital entrepreneurship in Nigeria, infrastructural/institutional inadequacies, lack of funding opportunities, and unfavourable government policies, were considered inimical to entrepreneurial capabilities in the country.

Keywords: entrepreneurial capabilities, unemployment, business incubators, development

Procedia PDF Downloads 206

Authors: Muhammad Tariq, Muhammad Waseem, Muhammad Hidayat Rasool

Abstract:

Isolation and characterization of chromium tolerant Staphylococcus aureus from industrial wastewater and their potential use to bioremediate environmental chromium. Objectives: Chromium with its great economic importance in industrial use is major metal pollutant of the environment. Chromium are used in different industries for various applications such as textile, dyeing and pigmentation, wood preservation, manufacturing pulp and paper, chrome plating, steel and tanning. The release of untreated chromium in industrial effluents causes serious threat to environment and human health, therefore, the current study designed to isolate chromium tolerant Staphylococcus aureus for removal of chromium prior to their final discharge into the environment due to its cost effective and beneficial advantage over physical and chemical methods. Methods: Wastewater samples were collected from discharge point of different industries. Heavy metal analysis by atomic absorption spectrophotometer and microbiological analysis such as total viable count, total coliform, fecal coliform and Escherichia coli were conducted. Staphylococcus aureus was identified through gram’s staining, biomeriux vitek 2 microbial identification system and 16S rRNA gene amplification by polymerase chain reaction. Optimum growth conditions with respect to temperature, pH, salt concentrations and effect of chromium on the growth of bacteria, resistance to other heavy metal ions, minimum inhibitory concentration and chromium uptake ability of Staphylococcus aureus strain K1 was determined by spectrophotometer. Antibiotic sensitivity pattern was also determined by disc diffusion method. Furthermore, chromium uptake ability was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope equipped with Oxford Energy Dipersive X-ray (EDX) micro analysis system. Results: The results presented that optimum temperature was 35ᵒC, pH was 8.0 and salt concentration was 0.5% for growth of Staphylococcus aureus K1. The maximum uptake ability of chromium by bacteria was 20mM than other heavy metal ions. The antibiotic sensitivity pattern revealed that Staphylococcus aureus was vancomycin and methicillin sensitive. Non hemolytic activity on blood agar and negative coagulase reaction showed that it was non-pathogenic. Furthermore, the growth of bacteria decreases in the presence of chromium and maximum chromium uptake by bacteria observed at optimum growth conditions. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and Energy dispersive X-ray (EDX) analysis confirmed the presence of chromium uptake by Staphylococcus aureus K1. Conclusion: The study revealed that Staphylococcus aureus K1 have the potential to bio-remediate chromium toxicity from wastewater. Gradually, this biological treatment becomes more important due to its advantage over physical and chemical methods to protect environment and human health.

Keywords: wastewater, staphylococcus, chromium, bioremediation

Procedia PDF Downloads 143

Authors: Till Fehlauer, Blanche Collin, Bernard Angeletti, Andrea Somogyi, Claire Lallemand, Perrine Chaurand, Cédric Dentant, Clement Levard, Jerome Rose

Abstract:

Over the last decades, yttrium (Y) has gained importance in high-tech applications. It is an essential part of alloys and compounds used for lasers, displays, or cell phones, for example. Due to its chemical similarities with the lanthanides, Y is often considered a rare earth element (REE). Despite their increased usage, the environmental behavior of REEs remains poorly understood. Especially regarding their interactions with plants, many uncertainties exist. On the one hand, Y is known to have a negative effect on root development and germination, but on the other hand, it appears to promote plant growth at low concentrations. In order to understand these phenomena, a precise knowledge is necessary about how Y is absorbed by the plant and how it is handled once inside the organism. Contradictory studies exist, stating that due to a similar ionic radius, Y and the other REEs might be absorbed through Ca²⁺-channels, while others suspect that Y has a shared pathway with Al³⁺. In this study, laser ablation coupled ICP-MS, and synchrotron-based micro-X-ray fluorescence (µXRF, beamline Nanoscopium, SOLEIL, France) have been used in order to localize Y within the plant tissue and identify associated elements. The plant used in this study is Saxifraga paniculata, a rugged alpine plant that has shown an affinity for Y in previous studies (in prep.). Furthermore, Saxifraga paniculata performs guttation, which means that it possesses phloem sap secreting openings on the leaf surface that serve to regulate root pressure. These so-called hydathodes could provide special insights in elemental transport in plants. The plants have been grown on Y doped soil (500mg/kg DW) for four months. The results showed that Y was mainly concentrated in the roots of Saxifraga paniculata (260 ± 85mg/kg), and only a small amount was translocated to the leaves (10 ± 7.8mg/kg). µXRF analysis indicated that within the root transects, the majority of Y remained in the epidermis and hardly penetrated the stele. Laser ablation coupled ICP-MS confirmed this finding and showed a positive correlation in the roots between Y, Fe, Al, and to a lesser extent Ca. In the stem transect, Y was mainly detected in a hotspot of approximately 40µm in diameter situated in the endodermis area. Within the stem and especially in the hotspot, Y was highly colocalized with Al and Fe. Similar-sized Y hotspots have been detected in/on the leaves. All of them were strongly colocalized with Al and Fe, except for those situated within the hydathodes, which showed no colocalization with any of the measured elements. Accordingly, a relation between Y and Ca during root uptake remains possible, whereas a correlation to Fe and Al appears to be dominant in the aerial parts, suggesting common storage compartments, the formation of complexes, or a shared pathway during translocation.

Keywords: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), Phytoaccumulation, Rare earth elements, Saxifraga paniculata, Synchrotron-based micro-X-ray fluorescence, Yttrium

Procedia PDF Downloads 125

Authors: Yuli Hou, Jianping Sun, Mengdan Gao, Hui Liu, Ling Qin, Ang Li, Dongfu Li, Yonghong Zhang, Yan Zhao

Abstract:

Background and Aims: Interferon-induced transmembrane protein 3 (IFITM3) is a component of ISG (Interferon-Stimulated Gene) family. IFITM3 has been recognized as a key signal molecule regulating cell growth in some tumors. However, the function of IFITM3 rs12252-CC genotype in the hepatocellular carcinoma (HCC) remains unknown to author’s best knowledge. A cohort study was employed to clarify the relationship between IFITM3 rs12252-CC genotype and HCC progression, and cellular experiments were used to investigate the correlation of function of IFITM3 and the progress of HCC. Methods: 336 candidates were enrolled in study, including 156 with HBV related HCC and 180 with chronic Hepatitis B infections or liver cirrhosis. Polymerase chain reaction (PCR) was employed to determine the gene polymorphism of IFITM3. The functions of IFITM3 were detected in PLC/PRF/5 cell with different treated:LV-IFITM3 transfected with lentivirus to knockdown the expression of IFITM3 and LV-NC transfected with empty lentivirus as negative control. The IFITM3 expression, proliferation and migration were detected by Quantitative reverse transcription polymerase chain reaction (qRT-PCR), QuantiGene Plex 2.0 assay, western blotting, immunohistochemistry, Cell Counting Kit(CCK)-8 and wound healing respectively. Six samples (three infected with empty lentiviral as control; three infected with LV-IFITM3 vector lentiviral as experimental group ) of PLC/PRF/5 were sequenced at BGI (Beijing Genomics Institute, Shenzhen,China) using RNA-seq technology to identify the IFITM3-related signaling pathways and chose PI3K/AKT pathway as related signaling to verify. Results: The patients with HCC had a significantly higher proportion of IFITM3 rs12252-CC compared with the patients with chronic HBV infection or liver cirrhosis. The distribution of CC genotype in HCC patients with low differentiation was significantly higher than that in those with high differentiation. Patients with CC genotype found with bigger tumor size, higher percentage of vascular thrombosis, higher distribution of low differentiation and higher 5-year relapse rate than those with CT/TT genotypes. The expression of IFITM3 was higher in HCC tissues than adjacent normal tissues, and the level of IFITM3 was higher in HCC tissues with low differentiation and metastatic than high/medium differentiation and without metastatic. Higher RNA level of IFITM3 was found in CC genotype than TT genotype. In PLC/PRF/5 cell with knockdown, the ability of cell proliferation and migration was inhibited. Analysis RNA sequencing and verification of RT-PCR found out the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin(PI3K/AKT/mTOR) pathway was associated with knockdown IFITM3.With the inhibition of IFITM3, the expression of PI3K/AKT/mTOR signaling pathway was blocked and the expression of vimentin was decreased. Conclusions: IFITM3 rs12252-CC with the higher expression plays a vital role in the progress of HCC by regulating HCC cell proliferation and migration. These effects are associated with PI3K/AKT/mTOR signaling pathway.

Keywords: IFITM3, interferon-induced transmembrane protein 3, HCC, hepatocellular carcinoma, PI3K/ AKT/mTOR, phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin

Procedia PDF Downloads 105

Authors: Michel Patiño-Sáenz, Martín Haissiner, Jorge Martínez-Cotrina, Daniel Pastor, Hernando Santamaría-García, Maria-Alejandra Tangarife, Agustin Ibáñez, Sandra Baez

Abstract:

It has been shown that gruesome descriptions of harm can increase the punishment given to a transgressor. This biasing effect is mediated by negative emotions, which are elicited upon the presentation of gruesome descriptions. However, there is a lack of studies inquiring the influence of such descriptions on moral decision-making in people involved in the criminal justice system. Such populations are of special interest since they have experience dealing with gruesome evidence, but also formal education on how to assess evidence and gauge the appropriate punishment according to the law. Likewise, they are expected to be objective and rational when performing their duty, because their decisions can impact profoundly people`s lives. Considering these antecedents, the objective of this study was to explore the influence gruesome written descriptions on moral decision-making in this group of people. To that end, we recruited attorneys, judges and public prosecutors (Criminal justice group, CJ, n=30) whose field of specialty is criminal law. In addition, we included a control group of people who did not have a formal education in law (n=30), but who were paired in age and years of education with the CJ group. All participants completed an online, Spanish-adapted version of a moral decision-making task, which was previously reported in the literature and also standardized and validated in the Latin-American context. A series of text-based stories describing two characters, one inflicting harm on the other, were presented to participants. Transgressor's intentionality (accidental vs. intentional harm) and language (gruesome vs. plain) used to describe harm were manipulated employing a within-subjects and a between-subjects design, respectively. After reading each story, participants were asked to rate (a) the harmful action's moral adequacy, (b) the amount of punishment deserving the transgressor and (c) how damaging was his behavior. Results showed main effects of group, intentionality and type of language on all dependent measures. In both groups, intentional harmful actions were rated as significantly less morally adequate, were punished more severely and were deemed as more damaging. Moreover, control subjects deemed more damaging and punished more severely any type of action than the CJ group. In addition, there was an interaction between intentionality and group. People in the control group rated harmful actions as less morally adequate than the CJ group, but only when the action was accidental. Also, there was an interaction between intentionality and language on punishment ratings. Controls punished more when harm was described using gruesome language. However, that was not the case of people in the CJ group, who assigned the same amount of punishment in both conditions. In conclusion, participants with job experience in the criminal justice system or criminal law differ in the way they make moral decisions. Particularly, it seems that they are less sensitive to the biasing effect of gruesome evidence, which is probably explained by their formal education or their experience in dealing with such evidence. Nonetheless, more studies are needed to determine the impact this phenomenon has on the fulfillment of their duty.

Keywords: criminal justice system, emotions, gruesome descriptions, intentionality, moral decision-making

Procedia PDF Downloads 158

Authors: Pulakesh Das, Mukunda Dev Behera, Manchiraju Sri Ramachandra Murthy

Abstract:

Large numbers of people living in and around the Hindu Kush Himalaya (HKH) region, depends on this diverse mountainous region for ecosystem services. Following the global trend, this region also experiencing rapid population growth, and demand for timber and agriculture land. The eight countries sharing the HKH region have different forest resources utilization and conservation policies that exert varying forces in the forest ecosystem. This created a variable spatial as well altitudinal gradient in rate of deforestation and corresponding forest patch fragmentation. The quantitative relationship between fragmentation and demography has not been established before for HKH vis-à-vis along elevation gradient. This current study was carried out to attribute the overall and different nature in landscape fragmentations along the altitudinal gradient with the demography of each sharing countries. We have used the tree canopy cover data derived from Landsat data to analyze the deforestation and afforestation rate, and corresponding landscape fragmentation observed during 2000 – 2010. Area-weighted mean radius of gyration (AMN radius of gyration) was computed owing to its advantage as spatial indicator of fragmentation over non-spatial fragmentation indices. Using the subtraction method, the change in fragmentation was computed during 2000 – 2010. Using the tree canopy cover data as a surrogate of forest cover, highest forest loss was observed in Myanmar followed by China, India, Bangladesh, Nepal, Pakistan, Bhutan, and Afghanistan. However, the sequence of fragmentation was different after the maximum fragmentation observed in Myanmar followed by India, China, Bangladesh, and Bhutan; whereas increase in fragmentation was seen following the sequence of as Nepal, Pakistan, and Afghanistan. Using SRTM-derived DEM, we observed higher rate of fragmentation up to 2400m that corroborated with high human population for the year 2000 and 2010. To derive the nature of fragmentation along the altitudinal gradients, the Statistica software was used, where the user defined function was utilized for regression applying the Gauss-Newton estimation method with 50 iterations. We observed overall logarithmic decrease in fragmentation change (area-weighted mean radius of gyration), forest cover loss and population growth during 2000-2010 along the elevation gradient with very high R2 values (i.e., 0.889, 0.895, 0.944 respectively). The observed negative logarithmic function with the major contribution in the initial elevation gradients suggest to gap filling afforestation in the lower altitudes to enhance the forest patch connectivity. Our finding on the pattern of forest fragmentation and human population across the elevation gradient in HKH region will have policy level implication for different nations and would help in characterizing hotspots of change. Availability of free satellite derived data products on forest cover and DEM, grid-data on demography, and utility of geospatial tools helped in quick evaluation of the forest fragmentation vis-a-vis human impact pattern along the elevation gradient in HKH.

Keywords: area-weighted mean radius of gyration, fragmentation, human impact, tree canopy cover

Procedia PDF Downloads 189

Authors: Drishti Sharma, Mona Duggal

Abstract:

Background: WhatsApp can serve as a cost-effective, scalable, convenient, and popular medium for public health management related communication in the developing world where the existing system of communication is top-down and slow. The product supports sending and receiving a variety of media: text, photos, videos, documents, and location, as well as voice/video calls. With growing number of users of smartphones and improving access and penetration of internet, the scope of information technology remains immense in resolving the hurdles faced by traditional public health system. Poor infrastructure, gap in digital literacy, faulty documentation, strict organizational hierarchy and slow movement of information across desks and offices- all these, make WhatsApp an efficient prospect to complement the existing system for communication, feedback and leadership for public health system in India. Objective: This study investigates the benefits, challenges and limitations associated with WhatsApp usage as a public health management tool. Methods: The study was conducted within the Chandigarh Union Territory. We used a qualitative approach and conducted individual semi-structured interviews and group interviews (n = 10). Participants included medical officers (n 20), Program managers (n = 4), academicians (n=2) and administrators (n=2). Thematic and content qualitative analyses were conducted. Message log of the WhatsApp group of one of the health program was assessed. Results: Medical Officers said that WhatsApp helped them remain in touch with the program officer. They could easily give feedback and highlight those challenges which needed immediate intervention from the program managers, hence they felt supported. Also, the application helped them share pictures of their activities (meetings and field activities) with the group which they thought inspired others and gave themselves immense satisfaction. Also, it helped build stronger relationships and better coordination among themselves, the same being important in team events. For program managers, it had become a portal for coordinating large scale campaigns. Its reach and the fact that the feedback is real-time make WhatsApp ideal for district level events. Though the easy informal connectivity made them answerable to their staff but it also provided them with flexibility in operations. It turned out to be an important portal for sharing outcome and goals related feedback (both positive and negative) to the team. To be sure, using WhatsApp for the purpose of public health program presents considerable challenges, including technological barriers, organizational challenges, gender issues, confidentiality concerns and unplanned aftereffects. Nevertheless, its advantages in a low-cost setting make it an efficient alternative. Conclusion: WhatsApp has become an integral part of our lives. Use of this app for public health program management within closed groups looks promising and useful. At the same time, addressing the challenges involved would make its usage safer.

Keywords: communication, mobile technology, public health management, WhatsApp

Procedia PDF Downloads 148

Authors: Hamda M. Al-Ali

Abstract:

The ultimate aim of space exploration has been centralized around the possibility of life on other planets in the solar system. This aim is driven by the detrimental effects that climate change could potentially have on human survival on Earth in the future. This drives humans to search for feasible solutions to increase environmental and economical sustainability on Earth and to evaluate and explore the ability of human survival on other planets such as Mars. To do that, frequent space missions are required to meet the ambitious human goals. This means that reliable and affordable access to space is required, which could be largely achieved through the use of reusable spacecrafts. Therefore, materials and resources must be used wisely to meet the increasing demand. Space missions are currently extremely expensive to operate. However, reusing materials hence spacecrafts, can potentially reduce overall mission costs as well as the negative impact on both space and Earth environments. This is because reusing materials leads to less waste generated per mission, and therefore fewer landfill sites are required. Reusing materials reduces resource consumption, material production, and the need for processing new and replacement spacecraft and launch vehicle parts. Consequently, this will ease and facilitate human access to outer space as it will reduce the demand for scarce resources, which will boost material efficiency in the space industry. Material efficiency expresses the extent to which resources are consumed in the production cycle and how the waste produced by the industrial process is minimized. The strategies proposed in this paper to boost material efficiency in the space sector are the introduction of key performance indicators that are able to measure material efficiency as well as the introduction of clearly defined policies and legislation that can be easily implemented within the general practices in the space industry. Another strategy to improve material efficiency is by amplifying energy and resource efficiency through reusing materials. The circularity of various spacecraft materials such as Kevlar, steel, and aluminum alloys could be maximized through reusing them directly or after galvanizing them with another layer of material to act as a protective coat. This research paper has an aim to investigate and discuss how to improve material efficiency in space missions considering circular economy concepts so that space and Earth become more economically and environmentally sustainable. The circular economy is a transition from a make-use-waste linear model to a closed-loop socio-economic model, which is regenerative and restorative in nature. The implementation of a circular economy will reduce waste and pollution through maximizing material efficiency, ensuring that businesses can thrive and sustain. Further research into the extent to which reusable launch vehicles reduce space mission costs have been discussed, along with the environmental and economic implications it could have on the space sector and the environment. This has been examined through research and in-depth literature review of published reports, books, scientific articles, and journals. Keywords such as material efficiency, circular economy, reusable launch vehicles and spacecraft materials were used to search for relevant literature.

Keywords: circular economy, key performance indicator, material efficiency, reusable launch vehicles, spacecraft materials

Procedia PDF Downloads 98

Authors: Kevin W. Zobrist, Patricia A. Townsend, Nora M. Haider

Abstract:

Advanced Hardwood Biofuels Northwest (AHB) is a consortium funded by the United States Department of Agriculture (USDA) to research the potential for a system to produce advanced biofuels (jet fuel, diesel, and gasoline) from hybrid poplar in the Pacific Northwest region of the U.S. An Extension team was established as part of the project to examine community readiness and willingness to adopt hybrid as a purpose-grown bioenergy crop. The Extension team surveyed key stakeholder groups, including growers, Extension professionals, policy makers, and environmental groups, to examine attitudes and concerns about growing hybrid poplar for biofuels. The surveys found broad skepticism about the viability of such a system. The top concern for most stakeholder groups was economic viability and the availability of predictable markets. Growers had additional concerns stemming from negative past experience with hybrid poplar as an unprofitable endeavor for pulp and paper production. Additional barriers identified included overall land availability and the availability of water and water rights for irrigation in dry areas of the region. Since the beginning of the project, oil and natural gas prices have plummeted due to rapid increases in domestic production. This has exacerbated the problem with economic viability by making biofuels even less competitive than fossil fuels. However, the AHB project has identified intermediate market opportunities to use poplar as a renewable source for other biochemicals produced by petroleum refineries, such as acetic acid, ethyl acetate, ethanol, and ethylene. These chemicals can be produced at a lower cost with higher yields and higher, more-stable prices. Despite these promising market opportunities, the survey results suggest that it will still be challenging to induce growers to adopt hybrid poplar. Early adopters will be needed to establish an initial feedstock supply for a budding industry. Through demonstration sites and outreach events to various stakeholder groups, the project attracted interest from wastewater treatment facilities, since these facilities are already growing hybrid poplar plantations for applying biosolids and treated wastewater for further purification, clarification, and nutrient control through hybrid poplar’s phytoremediation capabilities. Since these facilities are already using hybrid poplar, selling the wood as feedstock for a biorefinery would be an added bonus rather than something requiring a high rate of return to compete with other crops and land uses. By holding regional workshops and conferences with wastewater professionals, AHB Extension has found strong interest from wastewater treatment operators. In conclusion, there are several significant barriers to developing a successful system for producing biofuels from hybrid poplar, with the largest barrier being economic viability. However, there is potential for wastewater treatment facilities to serve as early adopters for hybrid poplar production for intermediate biochemicals and eventually biofuels.

Keywords: hybrid poplar, biofuels, biochemicals, wastewater treatment

Procedia PDF Downloads 246

Authors: S. F. Afzali, W. L. Wong

Abstract:

The epizootic ulcerative syndrome (EUS) causes by the oomycete fungus, Aphanomyces invadans; known to be one of the infectious fish diseases for farmed and wild fishes in fresh and brackish-water from the Asia-pacific region, America and Africa. Although, EUS had been documented by the Office International des Epizooties (OIE) since 1995, hitherto, there is neither standard chemical agents that can be used for successful treatment of this destructive infection in the time of outbreak; nor available vaccine for prevention. Plant-based remedies in controlling fish diseases are gaining much attention recently as an alternative to chemical treatments, which possess negative effects to the environment and human. In present study, Sonneratia alba, a mangrove plant belongs to the Sonneratiaceae family, was screened in vitro and in vivo for its antifungal activity against A. invadans mycelium growth and its effects on fish innate immune system and disease resistant. The in vitro tests was performed using the disc diffusion methods with measurements of minimum inhibitory concentration (MIC) and inhibition zone. For in vivo study, the S. alba extract supplemented diets were administrated at 0.0, 1.0%, 3.0%, and 5.0% on healthy goldfish, Carassius auratus, which challenged with A. invadans zoospores (100 spores/ml). To compare the significant differences in the hematological and immunological parameters obtained from the experiments, the data were analysed using the SPSS. The methanol extract of S. alba effectively inhibited the mycelial growth of A. invadans at a minimum concentration of 1000 ppm for agar and filter paper diffusion experiments. In the agar diffusion test, 500 ppm of the extract inhibited the fungus mycelial growth up to 96 hours after exposure. The mycelial growth from the edge of the pre-inoculated A. invadans agar discs treated with S. alba extracts at concentrations of 100, 500 and 1000 ppm were 15, 8 and 0 mm respectively. The results of the filter paper disc test showed that the S. alba extract at its minimal inhibitory concentration (1000 ppm) has similar qualitative inhibitory effect as malachite green at 1 ppm and formalin at 250 ppm. According to the in vivo tests findings, in the infected fish fed with 3.0% and 5.0% supplementation diet, the numbers of white blood cell and myeloperoxidase activity significantly increased after the second week of treatment. Whilst the numbers of red blood cell significantly decreased in the infected fish fed with 0.0 and 1.0% supplementation diet. After the third week of feeding, significant increases in the total protein, albumin level, lysozyme activity were recorded in the infected fish fed with 3.0% and 5.0% supplementation diet. Also, the enriched diets increased the survival rate as compared to the untreated group that suffered from 90% mortality. The present study indicated that S. alba extract may inhibit the mycelial growth of A. invadans effectively, suggesting an alternative to other chemotherapeutic agents, which brought much environmental and health concerns to the public, for EUS treatment.

Keywords: fungal pathogen, goldfish, organic extract, treatment

Procedia PDF Downloads 255

Authors: Prescilla Lambert, Christophe Roos, Mounim Lebrini

Abstract:

For several years, the Caribbean islands and West Africa have had to deal with the massive arrival of the brown seaweed Sargassum. Overall, this macroalgae, which constitutes a habitat for a great diversity of marine organisms, is also an additional stress factor for the marine environment (e.g., coral reefs). In addition, the accumulation followed by the significant decomposition of the Sargassum spp. biomass on the coast leads to the release of toxic gases (H₂S and NH₃), which calls into question the functioning of the economic, health and tourist life of the island and the other interested territories. Originally, these algae are formed by the eutrophication of the oceans accentuated by global warming. Unfortunately, scientists predict a significant recurrence of these Sargassum strandings for years to come. It is therefore more than necessary to find solutions by putting in place a sustainable management plan for this phenomenon. Martinique, a small island in the Caribbean arc, is one of the many areas impacted by Sargassum seaweed strandings. Since 2011, there has been a constant increase in the degradation of the materials present in this region, largely due to toxic/corrosive gases released by the algae decomposition. In order to protect the structures and the vulnerable building materials while limiting the use of synthetic/petroleum based molecules as much as possible, research is being conducted on molecules of natural origin. Thus, thanks to the chemical composition, which comprise molecules with interesting properties, algae such as Sargassum could potentially help to solve many issues. Therefore, this study focuses on the green extraction and characterization of molecules from the species Sargassum fluitans and Sargassum natans present in Martinique. The secondary metabolites found in these extracts showed variability in yield rates due to local climatic conditions. The tests carried out shed light on the anticorrosive and antibacterial potential of the algae. These extracts can thus be described as natural inhibitors. The effect of variation in inhibitor concentrations was tested in electrochemistry using electrochemical impedance spectroscopy and polarization curves. The analysis of electrochemical results obtained by direct immersion in the extracts and self-assembled molecular layers (SAMs) for Sargassum fluitans III, Sargassum natans I and VIII species was conclusive in acid and alkaline environments. The excellent results obtained reveal an inhibitory efficacy of 88% at 50mg/L for the crude extract of Sargassum fluitans III and efficacies greater than 97% for the chemical families of Sargassum fluitans III. Similarly, microbiological tests also suggest a bactericidal character. Results for Sargassum fluitans III crude extract show a minimum inhibitory concentration (MIC) of 0.005 mg/mL on Gram-negative bacteria and a MIC greater than 0.6 mg/mL on Gram-positive bacteria. These results make it possible to consider the management of local and international issues while valuing a biomass rich in biodegradable molecules. The next step in this study will therefore be the evaluation of the toxicity of Sargassum spp..

Keywords: Sargassum, secondary metabolites, anticorrosive, antibacterial, natural inhibitors

Procedia PDF Downloads 42

Authors: Riadh Zorgati, Thomas Triboulet

Abstract:

In quite diverse application areas such as astronomy, medical imaging, geophysics or nondestructive evaluation, many problems related to calibration, fitting or estimation of a large number of input parameters of a model from a small amount of output noisy data, can be cast as inverse problems. Due to noisy data corruption, insufficient data and model errors, most inverse problems are ill-posed in a Hadamard sense, i.e. existence, uniqueness and stability of the solution are not guaranteed. A wide class of inverse problems in physics relates to the Fredholm equation of the first kind. The ill-posedness of such inverse problem results, after discretization, in a very ill-conditioned linear system of equations, the condition number of the associated matrix can typically range from 109 to 1018. This condition number plays the role of an amplifier of uncertainties on data during inversion and then, renders the inverse problem difficult to handle numerically. Similar problems appear in other areas such as numerical optimization when using interior points algorithms for solving linear programs leads to face ill-conditioned systems of linear equations. Devising efficient solution approaches for such system of equations is therefore of great practical interest. Efficient iterative algorithms are proposed for solving a system of linear equations. The approach is based on a preconditioning of the initial matrix of the system with an approximation of a generalized inverse leading to a stochastic preconditioned matrix. This approach, valid for non-negative matrices, is first extended to hermitian, semi-definite positive matrices and then generalized to any complex rectangular matrices. The main results obtained are as follows: 1) We are able to build a generalized inverse of any complex rectangular matrix which satisfies the convergence condition requested in iterative algorithms for solving a system of linear equations. This completes the (short) list of generalized inverse having this property, after Kaczmarz and Cimmino matrices. Theoretical results on both the characterization of the type of generalized inverse obtained and the convergence are derived. 2) Thanks to its properties, this matrix can be efficiently used in different solving schemes as Richardson-Tanabe or preconditioned conjugate gradients. 3) By using Lp norms, we propose generalized Kaczmarz’s type matrices. We also show how Cimmino's matrix can be considered as a particular case consisting in choosing the Euclidian norm in an asymmetrical structure. 4) Regarding numerical results obtained on some pathological well-known test-cases (Hilbert, Nakasaka, …), some of the proposed algorithms are empirically shown to be more efficient on ill-conditioned problems and more robust to error propagation than the known classical techniques we have tested (Gauss, Moore-Penrose inverse, minimum residue, conjugate gradients, Kaczmarz, Cimmino). We end on a very early prospective application of our approach based on stochastic matrices aiming at computing some parameters (such as the extreme values, the mean, the variance, …) of the solution of a linear system prior to its resolution. Such an approach, if it were to be efficient, would be a source of information on the solution of a system of linear equations.

Keywords: conditioning, generalized inverse, linear system, norms, stochastic matrix

Procedia PDF Downloads 110