Search results for: pull factor

Authors: Oyedele Ogundana, Amon Simba, Kostas Galanakis, Lynn Oxborrow

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The debate about factors influencing the business growth of women-owned businesses has been a topical issue in business management. Currently, scholars have identified the issues of access to money, market, and management as canvasing factors influencing the business growth of women-owned businesses. However, the influence of motherhood (household/family context) on business growth is inconclusive in the literature; despite that women are more family-oriented than their male counterparts. Therefore, this research study considers the influence of motherhood factor (household/family context) on the business growth of women-owned sewing businesses (WOSBs) in Lagos, Nigeria. The sewing business sector is chosen as the fashion industry (which includes sewing businesses) currently accounts for the second largest number of jobs in Sub-Saharan Africa, following agriculture. Thus, sewing businesses provide a rich ground for contributing to existing scholarly work. Research questions; (1) In what way does the motherhood factor influence the business growth of WOSBs in Lagos? (2) To what extent does the motherhood factor influence the business growth of WOSBs in Lagos? For the method design, a pragmatic approach, a mixed-methods technique and an abductive form of reasoning are adopted. The method design is chosen because it fits, better than other research perspectives, with the research questions posed in this study. For instance, using a positivist approach will not sufficiently answer research question 1, neither will an interpretive approach sufficiently answer research question 2. Therefore, the research method design is divided into 2 phases, and the results from one phase are used to inform the development of the subsequent phases (only phase 1 has been completed at the moment). The first phase uses qualitative data and analytical method to answer research question 1. While the second phase of the research uses quantitative data and analytical method to answer research question 2. For the qualitative phase, 5 WOSBs were purposefully selected and interviewed. The sampling technique is selected as it was not the intention of the researcher to make any statistical inferences, at this phase, rather the purpose was just exploratory. Therefore, the 5 sampled women comprised of 2 unmarried women, 1 married woman with no child, and 2 married women with children. A 40-60 minutes interview was conducted per participants. The interviews were audio-recorded and transcribed. Thereafter, the data were analysed using thematic analysis in order to unearth patterns and relationships. Findings for the first phase of this research reveals that motherhood (household/family context) directly influences (positively/negatively) the performance of WOSBs in Lagos. Apart from a direct influence on WOSBs, motherhood also moderates (positively/negatively) other factors–e.g., access to money, management/human resources and market/opportunities– influencing WOSBs in Lagos. To further strengthen this conclusion, a word frequency query result shows that ‘family,’ ‘husband’ and ‘children’ are among the 10 words used frequently in all the interview transcripts. This first phase contributes to existing studies by showing the various forms by which motherhood influences WOSBs. The second phase (which data are yet to be collected) would reveal the extent to which motherhood influence the business growth of WOSBs in Lagos.

Keywords: women-owned sewing businesses, business growth, motherhood, Lagos

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Authors: Bashayer Almalki, Mayar Bajrai, Dana Mirah, Kholood Alghamdi, Hala Sanyour

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This research aims to investigate the features of an AI chess app that are most preferred by users. A questionnaire was used as the methodology to gather responses from a varied group of participants. The questionnaire consisted of several questions related to the features of the AI chess app. The responses were analyzed using descriptive statistics and factor analysis. The findings indicate that the most preferred features of an AI chess app are the ability to play against the computer, the option to adjust the difficulty level, and the availability of tutorials and puzzles. The results of this research could be useful for developers of AI chess apps to enhance the user experience and satisfaction.

Keywords: chess, game, application, computics

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Authors: Huanru Wang, Jianzhun Jiang

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At present, the preparation of the catalyst by carbon carrier is one of the improvement directions of the C₂ pre-hydrogenation catalyst. Carbon materials can be prepared from coal direct liquefaction residues, coconut shells, biomass, etc., and the pore structure of carbon carrier materials can be adjusted through the preparation process; at high temperatures, the carbon carrier itself also shows certain catalytic activity. Therefore, this paper mainly selected typical activated carbon and coconut shell carbon as carbon carrier materials, studied their microstructure and surface properties, prepared a series of carbon-based catalysts loaded with Pd, and investigated the effects of the content of promoter Ag and the concentration of reductant on the structure and performance of the catalyst and its catalytic performance for the pre hydrogenation of C₂. In this paper, the carbon supports from two sources and the catalysts prepared by them were characterized in detail. The results showed that the morphology and structure of different supports and the performance of the catalysts prepared were also obviously different. The catalyst supported on coconut shell carbon has a small specific surface area and large pore diameter. The catalyst supported on activated carbon has a large specific surface area and rich pore structure. The active carbon support is mainly a mixture of amorphous graphite and microcrystalline graphite. For the catalyst prepared with coconut shell carbon as the carrier, the sample is very uneven, and its specific surface area and pore volume are irregular. Compared with coconut shell carbon, activated carbon is more suitable as the carrier of the C₂ hydrogenation catalyst. The conversion of acetylene, methyl acetylene, and butadiene decreased, and the ethylene selectivity increased after Ag was added to the supported Pd catalyst. When the amount of promoter Ag is 0.01-0.015%, the catalyst has relatively good catalytic performance. Ag and Pd form an alloying effect, thus reducing the effective demand for Ag. The Pd Ag ratio is the key factor affecting the catalytic performance. When the addition amount of Ag is 0.01-0.015%, the dispersion of Pd on the carbon support surface can be significantly improved, and the size of active particles can be reduced. The Pd Ag ratio is the main factor in improving the selectivity of the catalyst. When the additional amount of sodium formate is 1%, the catalyst prepared has both high acetylene conversion and high ethylene selectivity.

Keywords: C₂ hydrogenation, activated carbon, Ag promoter, Pd catalysts

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Authors: Bharath Anantharamaiah, Tomas Bouda, Elke Deckers, Stijn Jonckheere, Wim Desmet, Juan J. Garcia

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Automotive tyres are gaining importance recently in terms of their noise emission, not only with respect to reduction in noise, but also their perception and detection. Tyres exhibit a mechanical noise generation mechanism up to 1 kHz. However, owing to the fact that tyre is a composite of several materials, it has been difficult to model it using finite elements to predict noise at high frequencies. The currently available FE models have a reliability of about 500 Hz, the limit which, however, is not enough to perceive the roughness or sharpness of noise from tyre. These noise components are important in order to alert pedestrians on the street about passing by slow, especially electric vehicles. In order to model tyre noise behaviour up to 1 kHz, its dynamic behaviour must be accurately developed up to a 1 kHz limit using finite elements. Materials play a vital role in modelling the dynamic tyre behaviour precisely. Since tyre is a composition of several components, their precise definition in finite element simulations is necessary. However, during the tyre manufacturing process, these components are subjected to various pressures and temperatures, due to which these properties could change. Hence, material definitions are better described based on the tyre responses. In this work, the hyperelasticity of tyre component rubbers is calibrated, using the design of experiments technique from the tyre characteristic responses that are measured on a stiffness measurement machine. The viscoelasticity of rubbers are defined by the Prony series for rubbers, which are determined from the loss factor relationship between the loss and storage moduli, assuming that the rubbers are excited within the linear viscoelasticity ranges. These values of loss factor are measured and theoretically expressed as a function of rubber shore hardness or hyperelasticities. From the results of the work, there exists a good correlation between test and simulation vibrational transfer function up to 1 kHz. The model also allows flexibility, i.e., the frequency limit can also be extended, if required, by calibrating the Prony parameters of rubbers corresponding to the frequency of interest. As future work, these tyre models are used for noise generation at high frequencies and thus for tyre noise perception.

Keywords: tyre dynamics, rubber materials, prony series, hyperelasticity

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Authors: A. Abdi, A. Abbasi Daloee, A. Barari

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Aim: The adaptations that occur in human body after doing exercises training are a factor to help healthy people stay away from certain diseases. One of the main adaptations is a change in blood circulation, especially in vessels. The increase of capillary density is dependent on the balance between angiogenic and angiostatic factors. Most studies show that the changes made to angiogenic developmental factors resulted from physical exercises indicate the low level of stimulators compared with inhibitors. It is believed that the plasma level of VEGF-A, the important angiogenic factor, is reduced after physical exercise. Findings indicate that the extract of crataegus plant reduces the platelet-derived growth factor receptor (PDGFR) autophosphorylation in human's fibroblast. More importantly, crataegus (1 to 100 mg in liter) clearly leads to the inhibition of PDGFR autophosphorylation in vascular smooth muscle cells (VSMCs). Angiogenesis is a process that can be classified into physiological and pathophysiological forms. collagen XVIII is a part of extracellular protein and heparan sulfate proteoglycans in vascular epithelial and endothelial basement membrane cause the release of endostatin from noncollagenous collagen XVIII. Endostatin inhibits the growth of endothelial cells, inhibits angiogenesis, weakens different types of cancer, and the growth of tumors. The purpose of the current study was to investigate the effect of intensive aerobic running with or without aqueous extraction of black Crataegus elbursensis on Collagen XVIII in male rats. Design: Thirty-two Wistar male rats (4-6 weeks old, 125-135 gr weight) were acquired from the Pasteur's Institute (Amol, Mazandaran), and randomly assigned into control (n = 16) and training (n = 16) groups. Rats were further divided into saline-control (SC) (n=8), saline-training (ST) (n=8), crataegus pentaegyna extraction -control (CPEC) (n=8), and crataegus pentaegyna extraction - training (CPET) (n=8). The control (SC and CPEC) groups remained sedentary; whereas the training groups underwent a high running exercise program. plasma were excised and immediately frozen in liquid nitrogen. Statistical analysis was performed using a one way analysis of variance and Tukey test. Significance was accepted at P = 0.05. Results: The results show that aerobic exercise group had the highest concentration collagen XVIII compared to other groups and then respectively black crataegus, training-crataegus and control groups. Conclusion: In general, researchers in this study concluded that the increase of collagen XVIII (albeit insignificant) as a result of physical activity and consumption of black crataegus extract could possibly serve as a regional inhibitor of angiogenesis and another evidence for the anti-cancer effects of physical activities. Since the research has not managed in this study to measure the amount of plasma endostatin, it is suggested that both indices are measured with important angiogenic factors so that we can have a more accurate interpretation of changes to angiogenic and angiostatic factors resulted from physical exercises.

Keywords: aerobic running, Crataegus elbursensis, Collagen XVIII

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Authors: Sankhanil Das, Arunava Dasgupta, Keya Mitra

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This paper investigates the relationship between natural ecological systems and modern urban morphology. Over years, ecological conditions represented by natural resources such as natural landforms, systems of water, urban geography and land covers have been a significant driving factor of how settlements have formed, expanded and functioned. These have played a pivotal role in formation of the community character and the cultural identity of the urban spaces, and have steered cultural behavior within these settings. Such cultural behaviors have been instrumental in transforming mere spaces to places with meaning and symbolism. The natural process of city formation is principally founded upon the idea of balance and harmony, mostly in a subconscious manner. Reimaging such processes of natural evolution, this paper systematically builds a development model that generates a balance between environment and development, with specific focus on the Urban-Rural fringe areas in the Temple Town of Puri, in Eastern India. Puri represents a unique cross section of ecological landscape, cultural practices and religious symbolism with a very rich history and a vibrant heritage. While the city centre gets more and more crowded by tourists and pilgrims to accommodate related businesses, the original residents of Puri relocate to move towards the urban peripheral areas for better living conditions, gradually converting agricultural lands into non agricultural uses. This rapid spread into the rural hinterland is devoid of any connection with the rich cultural identity of Puri. These past four decades of ‘development’ has been at the cost of 810 Hectares of ecological Lake systems in the region. Invaluable ecological resources at urban rural edges are often viewed as hindrances to development and conceptualized as taking away from the image of the city. This paper attempts to understand the language of development over years on existing natural resources through topo-analysis and proposes a sustainable approach of development using different planning tools, with ecological resources as the pivotal factor of development.

Keywords: livability, sustainable development, urbanization, urban-rural edge

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Authors: Sakda Loetpiparwanich, Preecha Vichitthamaros

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Nowadays, poor data quality is considered one of the majority costs for a data project. The data project with data quality awareness almost as much time to data quality processes while data project without data quality awareness negatively impacts financial resources, efficiency, productivity, and credibility. One of the processes that take a long time is defining the expectations and measurements of data quality because the expectation is different up to the purpose of each data project. Especially, big data project that maybe involves with many datasets and stakeholders, that take a long time to discuss and define quality expectations and measurements. Therefore, this study aimed at developing meaningful indicators to describe overall data quality for each dataset to quick comparison and priority. The objectives of this study were to: (1) Develop a practical data quality indicators and measurements, (2) Develop data quality dimensions based on statistical characteristics and (3) Develop Composite Indicator that can describe overall data quality for each dataset. The sample consisted of more than 500 datasets from public sources obtained by random sampling. After datasets were collected, there are five steps to develop the Dataset Quality Index (SDQI). First, we define standard data quality expectations. Second, we find any indicators that can measure directly to data within datasets. Thirdly, each indicator aggregates to dimension using factor analysis. Next, the indicators and dimensions were weighted by an effort for data preparing process and usability. Finally, the dimensions aggregate to Composite Indicator. The results of these analyses showed that: (1) The developed useful indicators and measurements contained ten indicators. (2) the developed data quality dimension based on statistical characteristics, we found that ten indicators can be reduced to 4 dimensions. (3) The developed Composite Indicator, we found that the SDQI can describe overall datasets quality of each dataset and can separate into 3 Level as Good Quality, Acceptable Quality, and Poor Quality. The conclusion, the SDQI provide an overall description of data quality within datasets and meaningful composition. We can use SQDI to assess for all data in the data project, effort estimation, and priority. The SDQI also work well with Agile Method by using SDQI to assessment in the first sprint. After passing the initial evaluation, we can add more specific data quality indicators into the next sprint.

Keywords: data quality, dataset quality, data quality management, composite indicator, factor analysis, principal component analysis

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Authors: Anudeep Appe, Bhanu Poluparthi, Lakshmi Kasivajjula, Udai Mv, Sobha Bagadi, Punya Modi, Aditya Singh, Hemanth Gunupudi, Spenser Troiano, Jeff Paul, Justin Stovall, Justin Yamamoto

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The necessity of data-driven decisions in healthcare strategy formulation is rapidly increasing. A reliable framework which helps identify factors impacting a healthcare provider facility or a hospital (from here on termed as facility) market share is of key importance. This pilot study aims at developing a data-driven machine learning-regression framework which aids strategists in formulating key decisions to improve the facility’s market share which in turn impacts in improving the quality of healthcare services. The US (United States) healthcare business is chosen for the study, and the data spanning 60 key facilities in Washington State and about 3 years of historical data is considered. In the current analysis, market share is termed as the ratio of the facility’s encounters to the total encounters among the group of potential competitor facilities. The current study proposes a two-pronged approach of competitor identification and regression approach to evaluate and predict market share, respectively. Leveraged model agnostic technique, SHAP, to quantify the relative importance of features impacting the market share. Typical techniques in literature to quantify the degree of competitiveness among facilities use an empirical method to calculate a competitive factor to interpret the severity of competition. The proposed method identifies a pool of competitors, develops Directed Acyclic Graphs (DAGs) and feature level word vectors, and evaluates the key connected components at the facility level. This technique is robust since its data-driven, which minimizes the bias from empirical techniques. The DAGs factor in partial correlations at various segregations and key demographics of facilities along with a placeholder to factor in various business rules (for ex. quantifying the patient exchanges, provider references, and sister facilities). Identified are the multiple groups of competitors among facilities. Leveraging the competitors' identified developed and fine-tuned Random Forest Regression model to predict the market share. To identify key drivers of market share at an overall level, permutation feature importance of the attributes was calculated. For relative quantification of features at a facility level, incorporated SHAP (SHapley Additive exPlanations), a model agnostic explainer. This helped to identify and rank the attributes at each facility which impacts the market share. This approach proposes an amalgamation of the two popular and efficient modeling practices, viz., machine learning with graphs and tree-based regression techniques to reduce the bias. With these, we helped to drive strategic business decisions.

Keywords: competition, DAGs, facility, healthcare, machine learning, market share, random forest, SHAP

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Authors: Sylvia Mac

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This ethnographic case study examines disaster capitalism, neoliberal market-based school reforms, and disability through the lens of Disability Studies in Education. More specifically, it explores neoliberalism and special education at a small, urban charter school in a large city in California and the (re)production of social inequality. The study uses Sociology of Special Education to examine the ways in which special education is used to sort and stratify disabled students. At a time when rhetoric surrounding public schools is framed in catastrophic and dismal language in order to justify the privatization of public education, small urban charter schools must be examined to learn if they are living up to their promise or acting as another way to maintain economic and racial segregation. The study concludes that neoliberal contexts threaten successful inclusive education and normalize poor, disabled students’ continued low achievement and poor post-secondary outcomes. This ethnographic case study took place at a small urban charter school in a large city in California. Participants included three special education students, the special education teacher, the special education assistant, a regular education teacher, and the two founders and charter writers. The school claimed to have a push-in model of special education where all special education students were fully included in the general education classroom. Although presented as fully inclusive, some special education students also attended a pull-out class called Study Skills. The study found that inclusion and neoliberalism are differing ideologies that cannot co-exist. Successful inclusive environments cannot thrive while under the influences of neoliberal education policies such as efficiency and cost-cutting. Additionally, the push for students to join the global knowledge economy means that more and more low attainers are further marginalized and kept in poverty. At this school, neoliberal ideology eclipsed the promise of inclusive education for special education students. This case study has shown the need for inclusive education to be interrogated through lenses that consider macro factors, such as neoliberal ideology in public education, as well as the emerging global knowledge economy and increasing income inequality. Barriers to inclusion inside the school, such as teachers’ attitudes, teacher preparedness, and school infrastructure paint only part of the picture. Inclusive education is also threatened by neoliberal ideology that shifts the responsibility from the state to the individual. This ideology is dangerous because it reifies the stereotypes of disabled students as lazy, needs drains on already dwindling budgets. If these stereotypes persist, inclusive education will have a difficult time succeeding. In order to more fully examine the ways in which inclusive education can become truly emancipatory, we need more analysis on the relationship between neoliberalism, disability, and special education.

Keywords: case study, disaster capitalism, inclusive education, neoliberalism

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Authors: Kiyohiro Yamazaki

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The purpose of this paper is to examine the hypothesis explaining the mechanism in the case, where the product is deleted or reduced the fundamental function of the product through the product concept changes in the digital camera industry. This paper points out not owning the fundamental technology might cause the change of the product concept. Casio could create new competitive factor so that this paper discusses a possibility of the mechanism of changing the product concept.

Keywords: firm without fundamental technology, product development, product concept, digital camera industry, Casio

Procedia PDF Downloads 555

Authors: Sangseung Kang, Kyekyung Kim, Suyoung Chi

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A good posture is the most important factor in riding. In this paper, we present an effective posture correction system for a riding simulator environment to provide position error detection and customized training functions. The proposed system detects and analyzes the rider's posture using depth data and inertial sensing data. Our experiments show that including these functions will help users improve their seat for a riding.

Keywords: posture correction, posture training, riding posture, riding simulator

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Authors: Suraina Sulong

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Keyboard support is one of the main accessibility requirements for web pages and web applications for blind user. But it is not sufficient that the blind user can perform all actions on the page using the keyboard. In addition, designers of web sites or web applications have to make sure that keyboard users can use their pages with acceptable performance. We present GOMS models for navigation in web pages with specific task given to the blind user to accomplish. These models can be used to construct the user model for accessible website.

Keywords: GOMS analysis, usability factor, blind user, human computer interaction

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Authors: Mathodzi Nditsheni, Olawole Emmanuel Aina, Joshua Oluwole Olowoyo

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The ever-increasing world population is putting extreme pressure on the already limited agricultural resources for food production. Different soil enhancers were introduced by famers to meet the need of the ever-increasing population demand for food. One of the soil enhancers is the municipal waste sludge. This research investigated the differences in the concentrations of trace metals and levels of phytochemicals in four different tomato varieties cultivated on soil treated with municipal waste sludge in Pretoria, South Africa. Fruits were harvested at maturity and analyzed for trace metals and phytochemicals contents using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and a High-Performance Liquid Chromatography (HPLC) respectively. A one-way analysis of variance (ANOVA) was used to determine the differences in the concentrations of trace metals and phytochemical from different tomato varieties were significant. From the study, Rodade tomato bioaccumulated the highest concentrations of Mn, Cr, Cu and Ni, Roma bioaccumulated the highest concentrations of, Cd, Fe and Pb while Heinz bioaccumulated the highest concentrations of As and Zn. Cherry tomato on the other hand, recorded the lowest concentrations for most metals, Cd, Cr, Cu, Mn, Ni, Pb and Zn. The results of the study further showed that phenolic and flavonoids content were higher in the Solanum lycopersicum fruit grown in soils treated with municipal waste sludge. The study also showed that there was an inverse relationship between the levels of trace metals and phytochemicals. The calculated contamination factor values of trace metals like Cr, Cu, Pb and Zn were above the safe value of 1 which indicated that the tomato fruits may be unsafe for human consumption. However, the contamination factor values for the remaining trace metals were well below the safe value of 1. From the results obtained either for the control group or the treatment, the tomato varieties used in the study, bioaccumulated the toxic trace metals in their fruits and some of the values obtained were higher than the acceptable limit, which may then imply that the varieties of tomato used in this study bio accumulated the toxic trace metals from the soil, hence care should be taken when these tomato varieties are either cultivated or harvested from polluted areas

Keywords: trace metals, flavonoids, phenolics, waste sludge, tomato, contamination factors

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Authors: Mariam Khaled, Noha Farag, Ghada Mohamed Abdel Salam, Khaled Abu-Aisha, Mohamed El-Azizi

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Gastric and colorectal cancers are among the most frequent causes of cancer-associated mortalities in Africa. They have been considered as a global public health concern, as nearly one million new cases are reported per year. IL-1β is a pro-inflammatory cytokine-produced by activated macrophages and monocytes- and a member of the IL-1 family. The inactive IL-1β precursor is cleaved and activated by caspase-1 enzyme, which itself is activated by the assembly of intracellular structures defined as NLRP3 (Nod Like receptor P3) inflammasomes. Activated IL-1β stimulates the Interleukin-1 receptor type-1 (IL-1R1), which is responsible for the initiation of a signal transduction pathway leading to cell proliferation. It has been proven that the IL-1β gene is a highly polymorphic gene in which single nucleotide polymorphisms (SNPs) may affect its expression. It has been previously reported that SNPs including base transitions between C and T at positions, -511 (C-T; dbSNP: rs16944) and -31 (C-T; dbSNP: rs1143627), from the transcriptional start site, contribute to the pathogenesis of gastric and colorectal cancers by affecting IL-1β levels. Altered production of IL-1β due to such polymorphisms is suspected to stimulate an amplified inflammatory response and promote Epithelial Mesenchymal Transition leading to malignancy. Allele frequency distribution of the IL-1β-31 and -511 SNPs, in different populations, and their correlation to the incidence of gastric and colorectal cancers, has been intriguing to researchers worldwide. The current study aims to investigate allele distributions of the IL-1β SNPs among gastric and colorectal cancers Egyptian patients. In order to achieve to that, 89 Biopsy and surgical specimens from the antrum and corpus mucosa of chronic gastritis subjects and gastric and colorectal carcinoma patients was collected for DNA extraction followed by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). The amplified PCR products of IL-1β-31C > T and IL-1β-511T > C were digested by incubation with the restriction endonuclease enzymes ALu1 and Ava1. Statistical analysis was carried out to determine the allele frequency distribution in the three studied groups. Also, the effect of the IL-1β -31 and -511 SNPs on nuclear factor binding was analyzed using Fluorescence Electrophoretic Mobility Shift Assay (EMSA), preceded by nuclear factor extraction from gastric and colorectal tissue samples and LPS stimulated monocytes. The results of this study showed that a significantly higher percentage of Egyptian gastric cancer patients have a homozygous CC genotype at the IL-1β-31 position and a heterozygous TC genotype at the IL-1β-511 position. Moreover, a significantly higher percentage of the colorectal cancer patients have a homozygous CC genotype at the IL-1β-31 and -511 positions as compared to the control group. In addition, the EMSA results showed that IL-1β-31C/T and IL-1β-511T/C SNPs do not affect nuclear factor binding. Results of this study suggest that the IL-1β-31 C/T and IL-1β-511 T/C may be correlated to the incidence of gastric cancer in Egyptian patients; however, similar findings couldn’t be proven in the colorectal cancer patients group for the IL-1β-511 T/C SNP. This is the first study to investigate IL-1β -31 and -511 SNPs in the Egyptian population.

Keywords: colorectal cancer, Egyptian patients, gastric cancer, interleukin-1β, single nucleotide polymorphisms

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Authors: Arash Kosari, Ali Araghi

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A mathematical model for an optical-fiber communication channel is developed which results in an expression that calculates the throughput and loss of the corresponding link. The data are assumed to be transmitted by using of separate photons with different polarizations. The derived model also shows the dependency of data throughput with length of the channel and depolarization factor. It is observed that absorption of photons affects the throughput in a more intensive way in comparison with that of depolarization. Apart from that, the probability of depolarization and the absorption of radiated photons are obtained.

Keywords: absorption, data throughput, depolarization, optical fiber

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Authors: Arij Yehya, Suhaila Ghuloum, Abdlmoneim Abdulhakam, Azza Al-Mujalli, Mark Opler, Samer Hammoudeh, Yahya Hani, Sundus Mari, Reem Elsherbiny, Ziyad Mahfoud, Hassen Al-Amin

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Introduction: The Positive and Negative Syndrome Scale (PANSS) is a valid instrument developed by Kay and colleagues6 to assess symptoms of patients with schizophrenia. It consists of 30 items that factor the symptoms into three subscales: positive, negative and general psychopathology. This scale has been translated and validated in several languages. Objective: This study aims to determine the validity and psychometric properties of the Arabic version of the PANSS. Methods: A standardized translation and cultural adaptation method was adopted. Patients diagnosed with schizophrenia (n=98), according to psychiatrist’s diagnosis based on DSM-IV criteria, were recruited from the Psychiatry Department at Rumailah Hospital, Qatar. A first rater confirmed the diagnosis using the Arabic version of Mini International Neuropsychiatric Interview (MINI 6). A second and independent rater-administered the Arabic version of PANSS. Also, a control group (n=101), with no history of psychiatric disorder was recruited from the family and friends of the patients and from primary health care centers in Qatar. Results: There were more males than females in our sample of patients with schizophrenia (68.9% and 31.6%, respectively). On the other hand, in the control group the number of females outweighed that of males (58.4% and 41.6% respectively). The scale had a good internal consistency with Cronbach’s alpha 0.91. There was a significant difference between the scores on the three subscales of the PANSS. Patients with schizophrenia scored significantly higher (p<.0001) than the control subjects on subscales for positive symptoms 20.01(SD=7.21) and 7.30(SD=1.38), negative symptoms 18.89(SD=8.88) and 7.37(SD=2.38) and general psychopathology 34.41 (SD=11.56) and 16.93 (SD=3.93), respectively. Factor analysis and ROC curve were carried out to further test the psychometrics of the scale. Conclusions: The Arabic version of PANSS is a reliable and valid tool to assess both positive and negative symptoms of patients with schizophrenia in a balanced manner. In addition to providing the Arab population with a standardized tool to monitor symptoms of schizophrenia, this version provides a gateway to compare the prevalence of positive and negative symptoms in the Arab world which can be compared to others done elsewhere.

Keywords: Arabic version, assessment, diagnosis, schizophrenia, validation

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Authors: Kang Liu, Meng Liu, Meng-Long Wu, Da-Chang Yue, Hong-Yi Pan

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The soil setup is an important factor affecting pile bearing capacity; there are many factors that influence it, all of which are closely related to pile construction disturbances. During pile installation in soil, a significant amount of excess pore pressure is generated, creating disturbance zones around the pile. The dissipation rate of excess pore pressure is an important factor influencing the pile setup. The paper aims to examine how alterations in parameters within disturbance zones affect the dissipation of excess pore pressure. An axisymmetric FE model is used to simulate pile installation in clay, subsequently consolidation using Plaxis 3D. The influence of disturbed zone on setup is verified, by comparing the parametric studies in uniform field and non-uniform field. Three types of consolidation are employed: consolidation in three directions, vertical consolidation, horizontal consolidation. The results of the parametric study show that the permeability coefficient decreases, soil stiffness decreases, and reference pressure increases in the disturbance zone, resulting in an increase in the dissipation time of excess pore pressure and exhibiting a noticeable threshold phenomenon, which has been commonly overlooked in previous literature. The research in this paper suggests that significant thresholds occur when the coefficient of permeability decreases to half of the original site's value for three-directional and horizontal consolidation within the disturbed zone. Similarly, the threshold for vertical consolidation is observed when the coefficient of permeability decreases to one-fourth of the original site's value. Especially in pile setup research, consolidation is assumed to be horizontal; the study findings suggest that horizontal consolidation has experienced notable alterations as a result of the presence of disturbed zones. Furthermore, the selection of pile installation methods proves to be critical. A nonlinearity excess pore pressure formula is proposed based on cavity expansion theory, which includes the distribution of soil profile modulus with depth.

Keywords: pile setup, threshold value effect, installation effects, uniform field, non-uniform field

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Authors: Abdulmalek Marwan Rajkhan, M. S. Al Ghamdi, Mohammed Damoum, Essam Banoqitah

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This paper is about the Am-Be neutron source irradiation of the InP Quantum Dot Laser diode. A QD LD was irradiated for 24 hours and 48 hours. The laser underwent IV characterization experiments before and after the first and second irradiations. A computer simulation using GAMOS helped in analyzing the given results from IV curves. The results showed an improvement in the QD LD series resistance, current density, and overall ideality factor at all measured temperatures. This is explained by the activation of the QD LD Indium composition to Strontium, ionization of the compound QD LD materials, and the energy deposited to the QD LD.

Keywords: quantum dot laser diode irradiation, effect of radiation on QD LD, Am-Be irradiation effect on SC QD LD

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Authors: Yee-Seul So, Guiseppe Ianiri, Alex Idnurm, Yong-Sun Bahn

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Tor1 is a serine/threonine protein kinase that is widely conserved across eukaryotic species. Tor1 was first identified in Saccharomyces cerevisiae as a target of rapamycin (TOR). The TOR pathway has been implicated in regulating cellular responses to nutrients, proliferation, translation, transcription, autophagy, and ribosome biogenesis. Here we identified two homologues of S. cerevisiae Tor proteins, CNAG_06642 (Tor1) and CNAG_05220 (Tlk1, TOR-like kinase 1), in Cryptococcus neoformans causing a life-threatening fungal meningoencephalitis. Both Tor1 and Tlk1 have rapamycin-binding (RB) domains but Tlk1 has truncated RB form. To study the TOR-signaling pathway in the fungal pathogen, we attempt to construct the tor1Δ and tlk1Δ mutants and phenotypically analyze them. Although we failed to construct the tor1Δ mutant, we successfully construct the tlk1Δ mutant. The tlk1Δ mutant does not exhibit any discernable phenotypes, suggesting that Tlk1 is dispensable in C. neoformans. The essentiality of TOR1 is independently confirmed by constructing the TOR1 promoter replacement strain by using a copper transporter 4 (CTR4) promoter and the TOR1/tor1 heterozygous mutant in diploid C. neoformans strain background followed by sporulation analysis. To further analyze the function of Tor1, we construct TOR1 overexpression mutant using a constitutively active histone H3 in C. neoformans. We find that the Tor1 overexpression mutant is resistant to rapamycin but the tlk1Δ mutant does not exhibit any altered resistance to rapamycin, further confirming that Tor1, but not Tlk1, is critical for TOR signaling. Furthermore, we found that Tor1 is involved in response to diverse stresses, including genotoxic stress, oxidative stress, thermo-stress, antifungal drug treatment, and production of melanin. To identify any TOR-related transcription factors, we screened C. neoformans transcription factor library that we constructed in our previous study and identified several potential downstream factors of Tor1, including Atf1, Crg1 and Bzp3. In conclusion, the current study provides insight into the role of the TOR signaling pathway in human fungal pathogens as well as C. neoformans.

Keywords: fungal pathogen, serine/threonine kinase, target of rapamycin, transcription factor

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Authors: Henda J Thomas, Cornelia PJ Harmse, Cecile Schultz

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Wearables are one of the technologies that will flourish within the fourth industrial revolution and digital transformation arenas, allowing employers to integrate collected data into organisational information systems. The study aimed to investigate whether wearable technology readiness can predict employees’ acceptance to wear wearables in the workplace. The factors of technology readiness predisposition that predict acceptance and positive attitudes towards wearable use in the workplace were examined. A quantitative research approach was used. The population consisted of 8 081 South African Department of Employment and Labour employees (DEL). Census sampling was used, and questionnaires to collect data were sent electronically to all 8 081 employees, 351 questionnaires were received back. The measuring instrument called the Technology Readiness and Acceptance Model (TRAM) was used in this study. Four hypotheses were formulated to investigate the relationship between readiness and acceptance of wearables in the workplace. The results found consistent predictions of technology acceptance (TA) by eagerness, optimism, and discomfort in the technology readiness (TR) scales. The TR scales of optimism and eagerness were consistent positive predictors of the TA scales, while discomfort proved to be a negative predictor for two of the three TA scales. Insecurity was found not to be a predictor of TA. It was recommended that the digital transformation policy of the DEL should be revised. Wearables in the workplace should be embraced from the viewpoint of convenience, automation, and seamless integration with the DEL information systems. The empirical contribution of this study can be seen in the fact that positive attitude emerged as a factor that extends the TRAM. In this study, positive attitude is identified as a new dimension to the TRAM not found in the original TA model and subsequent studies of the TRAM. Furthermore, this study found that Perceived Usefulness (PU) and Behavioural Intention to Use and (BIU) could not be separated but formed one factor. The methodological contribution of this study can lead to the development of a Wearable Readiness and Acceptance Model (WRAM). To the best of our knowledge, no author has yet introduced the WRAM into the body of knowledge.

Keywords: technology acceptance model, technology readiness index, technology readiness and acceptance model, wearable devices, wearable technology, fourth industrial revolution

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Authors: Edward P. Guillen, A. Karina Martinez Barliza

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Powerline Communications (PLC) as last mile solution to provide communication services, has the advantage of transmitting over channels already used for electrical distribution. However these channels have been not designed with this purpose, for that reason telecommunication companies in Colombia want to know how good would be using PLC in costs and network performance in comparison to cable modem or DSL. This paper analyzes PLC throughput for residential complex scenarios using a PLC network scenarios and some statistical results are shown.

Keywords: home network, power line communication, throughput analysis, power factor, cost, last mile solution

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Authors: Olivia Garcia, Sandra Tullio-Pow

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The purpose of this study was to understand what design attributes make the most ideal (wearable and memorable) national soccer jersey. The research probed Canadian soccer enthusiasts to better understand their jersey-purchasing rationale. The research questions framing this study were: how do consumers feel about their jerseys? How do these feelings influence their choices? There has been limited research on soccer jerseys from a material culture perspective, and it is not inclusive of national soccer jerseys. The results of this study may be used for product developers and advertisers who are looking to better understand the consumer base for national soccer jersey design. A mixed methods approach informed the research. To begin, a content analysis of all the home jerseys from the 2018 World Cup was done. Information such as size range, main colour, fibre content, brand, collar details, availability, sleeve length, place of manufacturing, pattern, price, fabric as per company, neckline, availability on company website, jersey inspiration, and badge/crest details were noted. Following the content analysis, wardrobe interviews were conducted with six consumers/fans. Participants brought two or more jerseys to the interviews, where the jerseys acted as clothing probes to recount information. Interview questions were semi-structured and focused on the participants’ relationship with the sport, their personal background, who they cheered for, why they bought the jerseys, and fit preferences. The goal of the inquiry was to pull out information on how participants feel about their jerseys and why. Finally, an interview with an industry professional was done. This interview was semi-structured, focusing on basic questions regarding sportswear design, sales, the popularity of soccer, and the manufacturing and marketing process. The findings proved that national soccer jerseys are an integral part of material culture. Women liked more fitted jerseys, and men liked more comfortable jerseys. Jerseys should be made with a cooling, comfortable fabric and should always prevent peeling. The symbols on jerseys are there to convey a team’s history and are most typically placed on the left chest. Jerseys should always represent the flag and/or the country’s colours and should use designs that are both fashionable and innovative. Jersey design should always consider the opinions of the consumers to help influence the design process. Jerseys should always use concepts surrounding culture, as consumers feel connected to the jerseys that represent the culture and/or family they have grown up with. Jerseys should use a team’s history, as well as the nostalgia associated with the team, as consumers prefer jerseys that reflect important moments in soccer. Jerseys must also sit at a reasonable price point for consumers, with an experience to go along with the jersey purchase. In conclusion, national soccer jerseys are considered sites of attachment and memories and play an integral part in the study of material culture.

Keywords: Design, Fashion, Material Culture, Sport

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Authors: Mahsa Mousavi, Hamid Reza Pourshaghaghi, Mohammad Tahghighi, Henk Corporaal

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Recently, Statistic Random-Access Memory-based (SRAM-based) Field-Programmable Gate Arrays (FPGAs) are widely used in aeronautics and space systems where high dependability is demanded and considered as a mandatory requirement. Since design’s circuit is stored in configuration memory in SRAM-based FPGAs; they are very sensitive to Single Event Upsets (SEUs). In addition, the adverse effects of SEUs on the electronics used in space are much higher than in the Earth. Thus, developing fault tolerant techniques play crucial roles for the use of SRAM-based FPGAs in space. However, fault tolerance techniques introduce additional penalties in system parameters, e.g., area, power, performance and design time. In this paper, an accurate estimation of configuration memory vulnerability to SEUs is proposed for approximate-tolerant applications. This vulnerability estimation is highly required for compromising between the overhead introduced by fault tolerance techniques and system robustness. In this paper, we study applications in which the exact final output value is not necessarily always a concern meaning that some of the SEU-induced changes in output values are negligible. We therefore define and propose Approximate-based Configuration Memory Vulnerability Factor (ACMVF) estimation to avoid overestimating configuration memory vulnerability to SEUs. In this paper, we assess the vulnerability of configuration memory by injecting SEUs in configuration memory bits and comparing the output values of a given circuit in presence of SEUs with expected correct output. In spite of conventional vulnerability factor calculation methods, which accounts any deviations from the expected value as failures, in our proposed method a threshold margin is considered depending on user-case applications. Given the proposed threshold margin in our model, a failure occurs only when the difference between the erroneous output value and the expected output value is more than this margin. The ACMVF is subsequently calculated by acquiring the ratio of failures with respect to the total number of SEU injections. In our paper, a test-bench for emulating SEUs and calculating ACMVF is implemented on Zynq-7000 FPGA platform. This system makes use of the Single Event Mitigation (SEM) IP core to inject SEUs into configuration memory bits of the target design implemented in Zynq-7000 FPGA. Experimental results for 32-bit adder show that, when 1% to 10% deviation from correct output is considered, the counted failures number is reduced 41% to 59% compared with the failures number counted by conventional vulnerability factor calculation. It means that estimation accuracy of the configuration memory vulnerability to SEUs is improved up to 58% in the case that 10% deviation is acceptable in output results. Note that less than 10% deviation in addition result is reasonably tolerable for many applications in approximate computing domain such as Convolutional Neural Network (CNN).

Keywords: fault tolerance, FPGA, single event upset, approximate computing

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Authors: Atin Mukherjee, Amitabha Sinha, Debesh Choudhury

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Fast Fourier transform (FFT) of large-number of samples requires larger hardware resources of field programmable gate arrays and it asks for more area as well as power. In this paper, an area efficient architecture of FFT processor is proposed, that reuses the butterfly units more than once. The FFT processor is emulated and the results are validated on Virtex-6 FPGA. The proposed architecture outperforms the conventional architecture of a N-point FFT processor in terms of area which is reduced by a factor of log_N(2) with the negligible increase of processing time.

Keywords: FFT, FPGA, resource optimization, butterfly units

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Authors: Grâce Chidikofan, François Pinta, A. Benoist, G. Volle, J. Valette

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Statement of the Problem: biomass gasification systems may be relevant for decentralized power generation from recoverable agricultural and wood residues available in rural areas. In recent years, many systems have been implemented in all over the world as especially in Cambodgia, India. Although they have many positive effects, these systems can also affect the environment and human health. Indeed, during the process of biomass gasification, black wastewater containing tars are produced and generally discharged in the local environment either into the rivers or on soil. However, in most environmental assessment studies of biomass gasification systems, the impact of these releases are underestimated, due to the difficulty of identification of their chemical substances. This work deal with the analysis of the environmental impacts of tars from wood gasification in terms of human toxicity cancer effect, human toxicity non-cancer effect, and freshwater ecotoxicity. Methodology: A Life Cycle Assessment (LCA) approach was adopted. The inventory of tars chemicals substances was based on experimental data from a downdraft gasification system. The composition of six samples from two batches of raw materials: one batch made of tree wood species (oak+ plane tree +pine) at 25 % moisture content and the second batch made of oak at 11% moisture content. The tests were carried out for different gasifier load rates, respectively in the range 50-75% and 50-100%. To choose the environmental impacts assessment method, we compared the methods available in SIMAPRO tool (8.2.0) which are taking into account most of the chemical substances. The environmental impacts for 1kg of tars discharged were characterized by ILCD 2011+ method (V.1.08). Findings Experimental results revealed 38 important chemical substances in varying proportion from one test to another. Only 30 are characterized by ILCD 2011+ method, which is one of the best performing methods. The results show that wood species or moisture content have no significant impact on human toxicity noncancer effect (HTNCE) and freshwater ecotoxicity (FWE) for water release. For human toxicity cancer effect (HTCE), a small gap is observed between impact factors of the two batches, either 3.08E-7 CTUh/kg against 6.58E-7 CTUh/kg. On the other hand, it was found that the risk of negative effects is higher in case of tar release into water than on soil for all impact categories. Indeed, considering the set of samples, the average impact factor obtained for HTNCE varies respectively from 1.64 E-7 to 1.60E-8 CTUh/kg. For HTCE, the impact factor varies between 4.83E-07 CTUh/kg and 2.43E-08 CTUh/kg. The variability of those impact factors is relatively low for these two impact categories. Concerning FWE, the variability of impact factor is very high. It is 1.3E+03 CTUe/kg for tars release into water against 2.01E+01 CTUe/kg for tars release on soil. Statement concluding: The results of this study show that the environmental impacts of tars emission of biomass gasification systems can be consequent and it is important to investigate the ways to reduce them. For environmental research, these results represent an important step of a global environmental assessment of the studied systems. It could be used to better manage the wastewater containing tars to reduce as possible the impacts of numerous still running systems all over the world.

Keywords: biomass gasification, life cycle analysis, LCA, environmental impact, tars

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Authors: Ahmed Elwaleed, Huiho Jeong, Ali H. Abdelbagi, Nguyen Thi Quynh, Koji Arizono, Yasuhiro Ishibashi

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Artisanal and small-scale gold mining (ASGM) poses substantial risks to both human health and the environment, particularly through contamination of soil, water, and air. Prolonged exposure to ASGM-contaminated soils can lead to acute or chronic mercury toxicity. This study assesses the human health risks associated with mercury-contaminated soils and tailings in the Alebediah mining community in Sudan. Soil samples were collected from various locations within Alebediah, including ASGM areas, farmlands, and residential areas, along with tailings samples commonly found within ASGM sites. The evaluation of potential health risks to humans included the computation of the estimated daily intake (AvDI), the hazard quotient (HQ), and the hazard index (HI) for both adults and children. The primary exposure route identified as potentially posing a significant health risk was the volatilization of mercury from tailings samples, where mercury concentrations reached up to 25.5 mg/kg. In contrast, other samples within the ASGM area showed elevated mercury levels but did not present significant health risks, with HI values below 1. However, all areas indicated HI values above 1 for the remaining exposure routes. The study observed a decrease in mercury concentration with increasing distance from the ASGM community. Additionally, soil samples revealed elevated mercury levels exceeding background values, prompting an assessment of contamination levels using the enrichment factor (EF). The findings indicated that farmlands and residential areas exhibited depleted EF, while areas surrounding the ASGM community showed none to moderate pollution. In contrast, ASGM areas exhibited significant to extreme pollution. A GIS map was generated to visually depict the extent of mercury pollution, facilitating communication with stakeholders and decision-makers.

Keywords: mercury pollution, artisanal and small-scale gold mining, health risk assessment, hazard index, soil and tailings, enrichment factor

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Authors: Isabela Vieira, Leonor Carvalho Garcez, Adalmiro Pereira, Tânia Teixeira

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In the present work, we aim to analyse IKEA as a company, by focusing on its development, financial analysis and future benchmarks, as well as applying some of the knowledge learned in class, namely hedging and other financial risk mitigation solutions, to understand how IKEA navigates and protects itself from risk. The decision that led us to choose IKEA for our casework has to do with the long history of the company since the 1940s and its high internationalization in 63 different markets. The company also has clear financial reports which aided us in the making of the present essay and naturally, was a factor that contributed to our decision.

Keywords: Ikea, financial risk, risk management, hedge

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Authors: Massimiliano Biagini, Marco Spinsanti, Gabriella De Angelis, Sara Tomei, Ilaria Ferlenghi, Maria Scarselli, Alessia Biolchi, Alessandro Muzzi, Brunella Brunelli, Silvana Savino, Marzia M. Giuliani, Isabel Delany, Paolo Costantino, Rino Rappuoli, Vega Masignani, Nathalie Norais

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The gram-negative bacterium Neisseria meningitidis serogroup B (MenB) is an exclusively human pathogen representing the major cause of meningitides and severe sepsis in infants and children but also in young adults. This pathogen is usually present in the 30% of healthy population that act as a reservoir, spreading it through saliva and respiratory fluids during coughing, sneezing, kissing. Among surface-exposed protein components of this diplococcus, factor H binding protein is a lipoprotein proved to be a protective antigen used as a component of the recently licensed Bexsero vaccine. fHbp is a highly variable meningococcal protein: to reflect its remarkable sequence variability, it has been classified in three variants (or two subfamilies), and with poor cross-protection among the different variants. Furthermore, the level of fHbp expression varies significantly among strains, and this has also been considered an important factor for predicting MenB strain susceptibility to anti-fHbp antisera. Different methods have been used to assess fHbp expression on meningococcal strains, however, all these methods use anti-fHbp antibodies, and for this reason, the results are affected by the different affinity that antibodies can have to different antigenic variants. To overcome the limitations of an antibody-based quantification, we developed a quantitative Mass Spectrometry (MS) approach. Selected Reaction Monitoring (SRM) recently emerged as a powerful MS tool for detecting and quantifying proteins in complex mixtures. SRM is based on the targeted detection of ProteoTypicPeptides (PTPs), which are unique signatures of a protein that can be easily detected and quantified by MS. This approach, proven to be highly sensitive, quantitatively accurate and highly reproducible, was used to quantify the absolute amount of fHbp antigen in total extracts derived from 105 clinical isolates, evenly distributed among the three main variant groups and selected to be representative of the fHbp circulating subvariants around the world. We extended the study at the genetic level investigating the correlation between the differential level of expression and polymorphisms present within the genes and their promoter sequences. The implications of fHbp expression on the susceptibility of the strain to killing by anti-fHbp antisera are also presented. To date this is the first comprehensive fHbp expression profiling in a large panel of Neisseria meningitidis clinical isolates driven by an antibody-independent MS-based methodology, opening the door to new applications in vaccine coverage prediction and reinforcing the molecular understanding of released vaccines.

Keywords: quantitative mass spectrometry, Neisseria meningitidis, vaccines, bexsero, molecular epidemiology

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Authors: Yuri Nikitin, Veronika Rukas

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Within the framework of the FP7 project "START" the cooperation with European research centres has had a positive impact on raising the level of innovation researches and the introduction of innovations Institute for Super hard Materials of the National Academy of Sciences (ISM NAS) of Ukraine in the economy of Europe and Ukraine, which in turn permits to speeds up the way for Ukrainian science to the European research area through the creation in Ukraine the scientific organizations of innovative type.

Keywords: programs of the EU, innovative scientific results, innovation competence of the staff, commercialization in business of industry of the Europe and Ukraine

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Authors: Velitchko G. Tzatchkov, Petronilo E. Cortes-Mejia, J. Manuel Rodriguez-Varela, Jesus Figueroa-Vazquez

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Hydraulic headloss, expressed by the values of friction factor f and Manning’s coefficient n, is an important parameter in designing drainage pipes. Their values normally are taken from manufacturer recommendations, many times without sufficient experimental support. To our knowledge, currently there is no standard procedure for hydraulically testing such pipes. As a result of research carried out at the Mexican Institute of Water Technology, a laboratory testing procedure was proposed and applied on 6 and 12 inches diameter polyvinyl chloride (PVC) and high-density dual wall polyethylene pipe (HDPE) drainage pipes. While the PVC pipe is characterized by naturally smooth interior and exterior walls, the dual wall HDPE pipe has corrugated exterior wall and, although considered smooth, a slightly wavy interior wall. The pipes were tested at full and partially full pipe flow conditions. The tests for full pipe flow were carried out on a 31.47 m long pipe at flow velocities between 0.11 and 4.61 m/s. Water was supplied by gravity from a 10 m-high tank in some of the tests, and from a 3.20 m-high tank in the rest of the tests. Pressure was measured independently with piezometer readings and pressure transducers. The flow rate was measured by an ultrasonic meter. For the partially full pipe flow the pipe was placed inside an existing 49.63 m long zero slope (horizontal) channel. The flow depth was measured by piezometers located along the pipe, for flow rates between 2.84 and 35.65 L/s, measured by a rectangular weir. The observed flow profiles were then compared to computer generated theoretical gradually varied flow profiles for different Manning’s n values. It was found that Manning’s n, that normally is assumed constant for a given pipe material, is in fact dependent on flow velocity and pipe diameter for full pipe flow, and on flow depth for partially full pipe flow. Contrary to the expected higher values of n and f for the HDPE pipe, virtually the same values were obtained for the smooth interior wall PVC pipe and the slightly wavy interior wall HDPE pipe. The explanation of this fact was found in Henry Morris’ theory for smooth turbulent conduit flow over isolated roughness elements. Following Morris, three categories of the flow regimes are possible in a rough conduit: isolated roughness (or semi smooth turbulent) flow, wake interference (or hyper turbulent) flow, and skimming (or quasi-smooth) flow. Isolated roughness flow is characterized by friction drag turbulence over the wall between the roughness elements, independent vortex generation, and dissipation around each roughness element. In this regime, the wake and vortex generation zones at each element develop and dissipate before attaining the next element. The longitudinal spacing of the roughness elements and their height are important influencing agents. Given the slightly wavy form of the HDPE pipe interior wall, the flow for this type of pipe belongs to this category. Based on that theory, an equation for the hydraulic friction factor was obtained. The obtained coefficient values are going to be used in the Mexican design standards.

Keywords: drainage plastic pipes, hydraulic headloss, hydraulic friction factor, Manning’s n

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