Search results for: spatiotemporal continuous wavelet transform

Authors: Tettey Afi Pamela, Sotaro Fujii, Hidetoshi Saito, Kawaii Koichiro

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Introduction: Organisms employ adaptive mechanisms when faced with any stressor or risk of being wiped out. This has made it possible for them to survive in harsh environmental conditions such as increasing temperature, low pH, and anoxia. Some of the mechanisms they utilize include the expression of heat shock proteins, synthesis of cryoprotectants, and anhydrobiosis. Heat shock proteins (HSPs) have been widely studied to determine their involvement in stress tolerance among various organism, of which chironomid species have been no exception. We examined the survival and expression of genes encoding five (5) heat shock proteins (HSP70, HSP67, HSP60, HSP27, and HSP23) from Chironomus sulfurosus larvae reared from 1st instar at 25°C, 30°C, 35°C, and 40°C. Results: The highest survival rate was recorded at 30°C, followed by 25°C, then 35°C. Only a small percentage of C. sulfurosus survived at 40°C (14.5%). With regards to HSPs expression, some HSPs responded to an increase in high temperature. The relative expression levels were lowest at 30°C for HSP70, HSP60, HSP27, and HSP23. At 25°C and 40°C, HSP70, HSP67, HSP60, HSP27, and HSP23 had the highest expression. At 35°C, all had the lowest expression. Discussion: The expression of heat shock proteins varies from one species to another. We designated the genes HSP 70, HSP 67, HSP 60, HSP 27, and HSP 23 genes based on transcriptome analysis of C. sulfurosus. Our study can be termed as a long-heat shock study as C. sulfurosus was reared from the first instar to the fourth instar, and this might have led to a continuous induction of HSPs at 25°C. 40°C had the lowest survival but highest HSPs expression as C. sulfurosus larvae had to utilize HSPs for sustenance. These results and future high-throughput studies at both the transcriptome and proteome level will improve the information needed to predict the future geographic distribution of these species within the context of global warming.

Keywords: chironomid, heat shock proteins, high temperature, heat shock protein expression

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Authors: Navpreet Kaur, Himkusha Thakur, Nirmal Prabhakar

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The most controversial issue in crop production is the use of Organophosphate insecticides. This is evident in many reports that Organophosphate (OP) insecticides, among the broad range of pesticides are mainly involved in acute and chronic poisoning cases. OPs detection is of crucial importance for health protection, food and environmental safety. In our study, a nanocomposite of poly (3,4 ethylenedioxythiophene) (PEDOT) and multi-walled carbon nanotubes (MWCNTs) has been deposited electrochemically onto the surface of fluorine doped tin oxide sheets (FTO) for the analysis of malathion OP. The -COOH functionalization of MWCNTs has been done for the covalent binding with amino groups of AChE enzyme. The use of PEDOT-MWCNT films exhibited an excellent conductivity, enables fast transfer kinetics and provided a favourable biocompatible microenvironment for AChE, for the significant malathion OP detection. The prepared biosensors were characterized by Fourier transform infrared spectrometry (FTIR), Field emission-scanning electron microscopy (FE-SEM) and electrochemical studies. Various optimization studies were done for different parameters including pH (7.5), AChE concentration (50 mU), substrate concentration (0.3 mM) and inhibition time (10 min). Substrate kinetics has been performed and studied for the determination of Michaelis Menten constant. The detection limit for malathion OP was calculated to be 1 fM within the linear range 1 fM to 1 µM. The activity of inhibited AChE enzyme was restored to 98% of its original value by 2-pyridine aldoxime methiodide (2-PAM) (5 mM) treatment for 11 min. The oxime 2-PAM is able to remove malathion from the active site of AChE by means of trans-esterification reaction. The storage stability and reusability of the prepared biosensor is observed to be 30 days and seven times, respectively. The application of the developed biosensor has also been evaluated for spiked lettuce sample. Recoveries of malathion from the spiked lettuce sample ranged between 96-98%. The low detection limit obtained by the developed biosensor made them reliable, sensitive and a low cost process.

Keywords: PEDOT-MWCNT, malathion, organophosphates, acetylcholinesterase, biosensor, oxime (2-PAM)

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Authors: Mthiyane Pretty, Mitsui Toshiake, Nagano Hirohiko, Aycan Murat

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Among the most significant greenhouse gases released from rice fields are methane and carbon dioxide. The primary focus of this research was to quantify CH₄ and CO₂ gas using different 4 rice cultivars, two water regimes, and a recording of soil moisture and temperature. In this study, we hypothesized that paddy field soils may directly affect soil enzymatic activities and physicochemical properties in the rhizosphere soil of paddy fields and subsequently indirectly affect the activity, abundance, diversity, and community composition of methanogens, ultimately affecting CH₄ flux. The experiment was laid out in the randomized block design with two treatments and three replications for each genotype. In two treatments, paddy fields and artificial soil were used. 35 days after planting (DAP), continuous flooding irrigation, Alternate wetting, and drying (AWD) were applied during the vegetative stage. The highest recorded measurements of soil and environmental parameters were soil moisture at 76%, soil temperature at 28.3℃, Bulk EC at 0.99 ds/m, and pore water EC at 1,25, using HydraGO portable soil sensor system. Gas samples were carried out once on a weekly basis at 09:00 am and 12: 00 pm to obtain the mean GHG flux. Gas Chromatography (GC, Shimadzu, GC-2010, Japan) was used for the analysis of CH4 and CO₂. The treatments with paddy field soil had a 1.3℃ higher temperature than artificial soil. The overall changes in Bulk EC were not significant across the treatment. The CH₄ emission patterns were observed in all rice genotypes, although they were less in treatments with AWD with artificial soil. This shows that AWD creates oxic conditions in the rice soil. CO₂ was also quantified, but it was in minute quantities, as rice plants were using CO₂ for photosynthesis. The highest tillering number was 7, and the lowest was 3 in cultivars grown. The rice varieties to be used for breeding are Norin 24, with showed a high number of tillers with less CH₄.

Keywords: greenhouse gases, methane, morphological characterization, alternating wetting and drying

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Authors: Dominic Huschke, Rudolf Keil

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New driving functionalities like highly automated driving have a major impact on the electrics/electronics architecture of future vehicles and inevitably lead to higher safety requirements. Partly due to these increased requirements, the vehicle industry is increasingly looking at semiconductor switches as an alternative to conventional melting fuses. The protective functionality of semiconductor switches can be implemented in hardware as well as in software. A current approach discussed in science and industry is the implementation of a model of the protected low voltage power cable on a microcontroller to calculate its temperature. Here, the information regarding the current is provided by the continuous current measurement of the semiconductor switch. The signal to open the semiconductor switch is provided by the microcontroller when a previously defined limit for the temperature of the low voltage power cable is exceeded. A setup for the testing of the described principle for electronic fuse protection of a low voltage power cable is built and successfullyvalidated with experiments afterwards. Here, the evaluation criterion is the deviation of the measured temperature of the low voltage power cable from the specified limit temperature when the semiconductor switch is opened. The analysis is carried out with an assumed ambient temperature as well as with a measured ambient temperature. Subsequently, the experimentally performed investigations are simulated in a virtual environment. The explicit focus is on the simulation of the behavior of the microcontroller with an implemented model of a low voltage power cable in a real-time environment. Subsequently, the generated results are compared with those of the experiments. Based on this, the completely virtual design of the described approach is assumed to be valid.

Keywords: automotive wire harness, electronic fuse protection, low voltage power cable, semiconductor-based fuses, software-based validation

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Authors: Nigina Toktasynova, Sholpan Sagyndykova, Zhanat Kenzhebayeva, Maksat Kalimoldayev, Mariya Ishimova, Irbulat Utepbergenov

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Any business needs a stable operation and continuous improvement, therefore it is necessary to constantly interact with the environment, to analyze the work of the enterprise in terms of employees, executives and consumers, as well as to correct any inconsistencies of certain types of processes and their aggregate. In the case of heat supply organizations, in addition to suppliers, local legislation must be considered which often is the main regulator of pricing of services. In this case, the process approach used to build a functional organizational structure in these types of businesses in Kazakhstan is a challenge not only in the implementation, but also in ways of analyzing the employee's salary. To solve these problems, we investigated the management system of heating enterprise, including strategic planning based on the balanced scorecard (BSC), quality management in accordance with the standards of the Quality Management System (QMS) ISO 9001 and analysis of the system based on expert judgment using fuzzy inference. To carry out our work we used the theory of fuzzy sets, the QMS in accordance with ISO 9001, BSC according to the method of Kaplan and Norton, method of construction of business processes according to the notation IDEF0, theory of modeling using Matlab software simulation tools and graphical programming LabVIEW. The results of the work are as follows: We determined possibilities of improving the management of heat-supply plant-based on QMS; after the justification and adaptation of software tool it has been used to automate a series of functions for the management and reduction of resources and for the maintenance of the system up to date; an application for the analysis of the QMS based on fuzzy inference has been created with novel organization of communication software with the application enabling the analysis of relevant data of enterprise management system.

Keywords: balanced scorecard, heat supply, quality management system, the theory of fuzzy sets

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Authors: Dejen Alemu, Murray E. Jennex, Temtim Assefa

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Agriculture is the mainstay of the Ethiopian economy; however, the sector is dominated by smallholder farmers resulting in land fragmentation and suffering from low productivity. Due to these issues, much effort has been put into the transformation of the sector to bring about more sustainable rural economic development. Technological advancements have been applied for the betterment of farmers resulting in the design of tools that are potentially capable of supporting the agricultural sector; however, their use and relevance are still alien to the local rural communities. The notion of the creating, capturing and sharing of knowledge has also been repetitively raised by many international donor agencies to transform the sector, yet the most current approaches to knowledge dissemination focus on knowledge that originates from the western view of scientific rationality while overlooking the role of indigenous knowledge (IK). Therefore, in agricultural knowledge management system (KMS) development, the integration of IKS with scientific knowledge is a critical success factor. The present study aims to contribute in the discourse on how to best integrate scientific and IK in agricultural KMS development. The conceptual framework of the research is anchored in concepts drawn from the theory of situated learning in communities of practice (CoPs): knowledge brokering. Using the KMS development practices of Ethiopian agricultural transformation agency as a case area, this research employed an interpretive analysis using primary and secondary qualitative data acquired through in-depth semi-structured interviews and participatory observations. As a result, concepts are identified for understanding the integration of the two major knowledge systems (i.e., indigenous and scientific knowledge) and participation of relevant stakeholders in particular the local farmers in agricultural KMS development through the roles of extension agent as a knowledge broker including crossing boundaries, in-between position, translation and interpretation, negotiation, and networking. The research shall have a theoretical contribution in addressing the incorporation of a variety of knowledge systems in agriculture and practically to provide insight for policy makers in agriculture regarding the importance of IK integration in agricultural KMS development and support marginalized small-scale farmers.

Keywords: communities of practice, indigenous knowledge, knowledge management system development, knowledge brokering

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Authors: Brendah Nagula, Omolo Fredrick Okalebo, Ronald Ssengendo, Ivan Bamweyana

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The Kampala Physical Development Plan (KPDP) was developed in 2012 and projected both long term and short term developments within the City .The purpose of the plan was to not only shape the city into a spatially planned area but also to control the urban sprawl trends that had expanded with pronounced instances of informal settlements. This plan was approved by the National Physical Planning Board and a signature was appended by the Minister in 2013. Much as the KPDP plan has been implemented using different approaches such as detailed planning, development control, subdivision planning, carrying out construction inspections, greening and beautification, there is still limited knowledge on the level of conformance towards this plan. Therefore, it is yet to be determined whether it has been effective in shaping the City into an ideal spatially planned area. Attaining a clear picture of the level of conformance towards the KPDP 2012 through evaluation between the planned and the existing land use in Kampala City was performed. Methods such as Supervised Classification and Post Classification Change Detection were adopted to perform this evaluation. Scrutiny of findings revealed Central Division registered the lowest level of conformance to the planning standards specified in the KPDP 2012 followed by Nakawa, Rubaga, Kawempe, and Makindye. Furthermore, mixed-use development was identified as the land use with the highest level of non-conformity of 25.11% and institutional land use registered the highest level of conformance of 84.45 %. The results show that the aspect of location was not carefully considered while allocating uses in the KPDP whereby areas located near the Central Business District have higher land rents and hence require uses that ensure profit maximization. Also, the prominence of development towards mixed-use denotes an increased demand for land towards compact development that was not catered for in the plan. Therefore in order to transform Kampala city into a spatially planned area, there is need to carefully develop detailed plans especially for all the Central Division planning precincts indicating considerations for land use densification.

Keywords: spatial plan, post classification change detection, Kampala city, landuse

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Authors: Yanling Li, Linying Ji, Zita Oravecz, Timothy R. Brick, Michael D. Hunter, Sy-Miin Chow

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Assessing several individuals intensively over time yields intensive longitudinal data (ILD). Even though ILD provide rich information, they also bring other data analytic challenges. One of these is the increased occurrence of missingness with increased study length, possibly under non-ignorable missingness scenarios. Multiple imputation (MI) handles missing data by creating several imputed data sets, and pooling the estimation results across imputed data sets to yield final estimates for inferential purposes. In this article, we introduce dynr.mi(), a function in the R package, Dynamic Modeling in R (dynr). The package dynr provides a suite of fast and accessible functions for estimating and visualizing the results from fitting linear and nonlinear dynamic systems models in discrete as well as continuous time. By integrating the estimation functions in dynr and the MI procedures available from the R package, Multivariate Imputation by Chained Equations (MICE), the dynr.mi() routine is designed to handle possibly non-ignorable missingness in the dependent variables and/or covariates in a user-specified dynamic systems model via MI, with convergence diagnostic check. We utilized dynr.mi() to examine, in the context of a vector autoregressive model, the relationships among individuals’ ambulatory physiological measures, and self-report affect valence and arousal. The results from MI were compared to those from listwise deletion of entries with missingness in the covariates. When we determined the number of iterations based on the convergence diagnostics available from dynr.mi(), differences in the statistical significance of the covariate parameters were observed between the listwise deletion and MI approaches. These results underscore the importance of considering diagnostic information in the implementation of MI procedures.

Keywords: dynamic modeling, missing data, mobility, multiple imputation

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Authors: Jiayun Shen, Lorenz Wyss, Thierry Golliard, Matthias Finger

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Innovation is widely recognized as the key for private enterprises to win the market competition. The state-owned-enterprises need to be innovative to compete in the market after the privatization as well. However, it is a lack of research to study how state-owned-enterprises manage innovation to create new products and services. Swiss Post, a Swiss state-owned-enterprises, has established a department to transform the corporate culture and foster innovation to achieve digital transformation. This paper describes the innovation management process at the Swiss Post and analyzes the impacts of the instruments, the organizational structure, and explores the barriers of innovation. This study used qualitative methods based on a review of the literature on innovation management and semi-structured interviews. Being established for over five years, the Swiss Post’s innovation management department has established a software-assisted modularized platform with systematic instruments to help the internal employees with the different innovation processes. It guides the innovators from idea creation to piloting in markets and supports with a separate financing source, with knowledge inputs and coaching, as well as with connections to external partners through the open innovation and venturing team. The platform also adapts to different business units within the corporate with a customized tailor for the various operational business units. The separate financing instruments enabled the creation and further development of new ideas; the coaching services contribute greatly to the transformation of teams’ innovation culture by providing new knowledge, thinking methods, and use cases for inspiration. It also facilitates organizational learning to help the whole corporate with the digital transformation. However, it is also confronted with a big challenge in twofold. Internally, the disruptive projects often hardly overcome the obstacles of long-established operational processes in the traditional business units; externally, the expectations of the public and restrictions from the federal government have become high hurdles for the company to stay and compete in the innovation track.

Keywords: empirical case study, innovation management, state-owned-enterprise, Swiss Post

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Authors: R. C. Tiwari, N. P. Bhandary, D. B. Thapa Chhetri, R. Yatabe

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The research enlightens the various issues of lake expansion and stability of the moraine dam of Imja lake. The Imja lake considered that the world highest altitude lake (5010m from m.s.l.), located in the Khumbu, Sagarmatha region of Nepal (27.90 N and 86.90 E) was reported as one of the fast growing glacier lakes in the Nepal Himalaya. The research explores a common phenomenon of lake expansion and stability issues of moraine dam to justify the necessity of lake lowering efforts if any in future in other glacier lakes in Nepal Himalaya. For this, we have explored the root causes of rapid lake expansion along with crucial factors responsible for the stability of moraine mass. This research helps to understand the structure of moraine dam and the ice, water and moraine interactions to the strength of moraine dam. The nature of permafrost layer and its effects on moraine dam stability is also studied here. The detail Geo-Technical properties of moraine mass of Imja lake gives a clear picture of the strength of the moraine material and their interactions. The stability analysis of the moraine dam under the consideration of strong ground motion of 7.8Mw 2015 Barpak-Gorkha and its major aftershock 7.3Mw Kodari, Sindhupalchowk-Dolakha border, Nepal earthquakes have also been carried out here to understand the necessity of lake lowering efforts. The lake lowering effort was recently done by Nepal Army by constructing an open channel and lowered 3m. And, it is believed that the entire region is now safe due to continuous draining of lake water by 3m. But, this option does not seem adequate to offer a significant risk reduction to downstream communities in this much amount of volume and depth, lowering as in the 75 million cubic meter water impounded with an average depth of 148.9m.

Keywords: finite element method, glacier, moraine, stability

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Authors: Sohni Siddiqui, Anja Schultze-Krumbholz

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Our lives now revolve more around online-related tasks, as the internet has become a necessity. One of the disturbance concerns with high internet usage is the multiplication of cyber-associated risky behaviors such as cyber aggression and/or cyberbullying. Cyber Bullying is an emerging issue that needs immediate attention from many stakeholders such as parents, doctors, school administrators, policymakers, researchers, and others, especially in the COVID-19 pandemic when online learning has been adopted as an instructional strategy, and there is a continuous rise in cyberbullying cases. The aim of the article is to review existing successful and emerging interventions designed to control bullying and cyberbullying by engaging individuals through teachers’ professional development and adopting a whole-school approach. The study identified the strengths and limitations of the programs and suggested improvements to existing interventions. Preparing interventions with a strong theoretical framework, integrating applications of emerging theories in interventions, promoting proactive and reactive strategies in combination, beginning with the baseline needs assessment surveys, reducing digital time and digital divide among parents and children, promoting the concept of lead trainer, peer trainer, and hot spots, focusing on physical activities, use of landmarks are some of the recommendations proposed by authors. In addition to face-to-face intervention, the researchers recommend updating and improving previous intervention programs with games and apps. Especially in the time of pandemic crises, when face-to-face interactions are limited and cyberbullying is triggered, the use of apps, web-based interventions, and games can be an effective way to control electronic perpetration and victimization.

Keywords: anti bullying programs, cyber bullying, individualized trainings, teachers’ professional development, whole school interventions

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Authors: Morteza Malek Yarand, Hadi Saebi Monfared

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This study aimed at designing and developing a mechanical force gauge for the square watermelon mold for the first time. It also tried to introduce the square watermelon characteristics and its production limitations. The mechanical force gauge performance and the product itself were also described. There are three main designable gauge models: a. hydraulic gauge, b. strain gauge, and c. mechanical gauge. The advantage of the hydraulic model is that it instantly displays the pressure and thus the force exerted by the melon. However, considering the inability to measure forces at all directions, complicated development, high cost, possible hydraulic fluid leak into the fruit chamber and the possible influence of increased ambient temperature on the fluid pressure, the development of this gauge was overruled. The second choice was to calculate pressure using the direct force a strain gauge. The main advantage of these strain gauges over spring types is their high precision in measurements; but with regard to the lack of conformity of strain gauge working range with water melon growth, calculations were faced with problems. Finally the mechanical pressure gauge has advantages, including the ability to measured forces and pressures on the mold surface during melon growth; the ability to display the peak forces; the ability to produce melon growth graph thanks to its continuous force measurements; the conformity of its manufacturing materials with the required physical conditions of melon growth; high air conditioning capability; the ability to permit sunlight reaches the melon rind (no yellowish skin and quality loss); fast and straightforward calibration; no damages to the product during assembling and disassembling; visual check capability of the product within the mold; applicable to all growth environments (field, greenhouses, etc.); simple process; low costs and so forth.

Keywords: mechanical force gauge, mold, reshaped fruit, square watermelon

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Authors: Eva Slaninova, Diana Cernayova, Zuzana Sedrlova, Katerina Mrazova, Petr Sedlacek, Jana Nebesarova, Stanislav Obruca

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Cyanobacteria are gram-negative prokaryotes belonging to a group of photosynthetic bacteria. In comparison with heterotrophic microorganisms, cyanobacteria utilize atmospheric nitrogen and carbon dioxide without any additional substrates. This ability of these microorganisms could be employed in biotechnology for the production of bioplastics, concretely polyhydroxyalkanoates (PHAs) which are primarily accumulated as a storage material in cells in the form of intracellular granules. In this study, there two cyanobacterial cultures from genera Synechocystis were used, namely Synechocystic sp. PCC 6803 and Synechocystis salina CCALA 192. There were optimized and used several various approaches, including microscopic techniques such as cryo-scanning electron microscopy (Cryo-SEM) and transmission electron microscopy (TEM), and fluorescence lifetime imaging microscopy using Nile red as a fluorescent probe (FLIM). Due to these instrumental techniques, the morphology of intracellular space and surface of cells were characterized. The next group of methods which were employed was spectroscopic techniques such as UV-Vis spectroscopy measured in two modes (turbidimetry and integration sphere) and Fourier transform infrared spectroscopy (FTIR). All these diverse techniques were used for the detection and characterization of pigments (chlorophylls, carotenoids, phycocyanin, etc.) and PHAs, in our case poly (3-hydroxybutyrate) (P3HB). To verify results, gas chromatography (GC) was employed concretely for the determination of the amount of P3HB in biomass. Cyanobacteria were also characterized as polyhydroxybutyrate producers by flow cytometer, which could count cells and at the same time distinguish cells including P3HB and without due to fluorescent probe called BODIPY and live/dead fluorescent probe SYTO Blue. Based on results, P3HB content in cyanobacteria cells was determined, as also the overall fitness of the cells. Acknowledgment: Funding: This study was partly funded by the projectGA19-29651L of the Czech Science Foundation (GACR) and partly funded by the Austrian Science Fund (FWF), project I 4082-B25.

Keywords: cyanobacteria, fluorescent probe, microscopic techniques, poly(3hydroxybutyrate), spectroscopy, chromatography

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Authors: Sahana Selladurai, Christine DeWolf

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Lung surfactant comprises a lipid-protein film that coats the alveolar surface and serves to prevent alveolar collapse upon repeated breathing cycles. Exposure of lung surfactant to high concentrations of airborne pollutants, for example tropospheric ozone in smog, can chemically modify the lipid and protein components. These chemical changes can impact the film functionality by decreasing the film’s collapse pressure (minimum surface tension attainable), altering it is mechanical and flow properties and modifying lipid reservoir formation essential for re-spreading of the film during the inhalation process. In this study, we use Langmuir monolayers spread at the air-water interface as model membranes where the compression and expansion of the film mimics the breathing cycle. The impact of ozone exposure on model lung surfactant films is measured using a Langmuir film balance, Brewster angle microscopy and a pendant drop tensiometer as a function of film and sub-phase composition. The oxidized films are analyzed using mass spectrometry where lipid and protein oxidation products are observed. Oxidation is shown to reduce surface activity, alter line tension (and film morphology) and in some cases visibly reduce the viscoelastic properties of the film when compared to controls. These reductions in functionality of the films are highly dependent on film and sub-phase composition, where for example, the effect of oxidation is more pronounced when using a physiologically relevant buffer as opposed to water as the sub-phase. These findings can lead to a better understanding on the impact of continuous exposure to high levels of ozone on the mechanical process of breathing, as well as understanding the roles of certain lung surfactant components in this process.

Keywords: lung surfactant, oxidation, ozone, viscoelasticity

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Authors: Nour S. Abdelrahman, Seunghyun Hong, Hassan A. Arafat, Daniel Choi, Faisal Al Marzooqi

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Abstract—The advancement of lithium extraction methods from water sources, particularly saltwater brine, is gaining prominence in the lithium recovery industry due to its cost-effectiveness. Traditional techniques like recrystallization, chemical precipitation, and solvent extraction for metal recovery from seawater or brine are energy-intensive and exhibit low efficiency. Moreover, the extensive use of organic solvents poses environmental concerns. As a result, there's a growing demand for environmentally friendly lithium recovery methods. Membrane-based separation technology has emerged as a promising alternative, offering high energy efficiency and ease of continuous operation. In our study, we explored the potential of lithium-selective sieve channels constructed from layers of 2D graphene oxide and MXene (transition metal carbides and nitrides), integrated with surface – SO₃₋ groups. The arrangement of these 2D sheets creates interplanar spacing ranging from 0.3 to 0.8 nm, which forms a barrier against multivalent ions while facilitating lithium-ion movement through nano capillaries. The introduction of the sulfonate group provides an effective pathway for Li⁺ ions, with a calculated binding energy of Li⁺ – SO³⁻ at – 0.77 eV, the lowest among monovalent species. These modified membranes demonstrated remarkably rapid transport of Li⁺ ions, efficiently distinguishing them from other monovalent and divalent species. This selectivity is achieved through a combination of size exclusion and varying binding affinities. The graphene oxide channels in these membranes showed exceptional inter-cation selectivity, with a Li⁺/Mg²⁺ selectivity ratio exceeding 104, surpassing commercial membranes. Additionally, these membranes achieved over 94% rejection of MgCl₂.

Keywords: ion permeation, lithium extraction, membrane-based separation, nanotechnology

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Authors: Eric Muñoz de la Torre, Julián González Trinidad, Efrén González Ramírez

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Rain varies greatly in its duration, intensity, and spatial coverage, it is important to have sub-daily rainfall data for various applications, including risk prevention. However, the ground measurements are limited by the low and irregular density of rain gauges. An alternative to this problem are the Satellite Precipitation Products (SPPs) that use passive microwave and infrared sensors to estimate rainfall, as IMERG, however, these SPPs have to be validated before their application. The aim of this study is to evaluate the performance of the IMERG: Integrated Multi-satellitE Retrievals for Global Precipitation Measurament final run V06B SPP in a semi-arid region of Mexico, using 4 automatic rain gauges (pluviographs) sub-daily data of October 2019 and June to September 2021, using the Minimum inter-event Time (MIT) criterion to separate unique rain events with a dry period of 10 hrs. for the purpose of evaluating the rainfall properties (depth, duration and intensity). Point to pixel analysis, continuous, categorical, and volumetric statistical metrics were used. Results show that IMERG is capable to estimate the rainfall depth with a slight overestimation but is unable to identify the real duration and intensity of the rain events, showing large overestimations and underestimations, respectively. The study zone presented 80 to 85 % of convective rain events, the rest were stratiform rain events, classified by the depth magnitude variation of IMERG pixels and pluviographs. IMERG showed poorer performance at detecting the first ones but had a good performance at estimating stratiform rain events that are originated by Cold Fronts.

Keywords: IMERG, rainfall, rain gauge, remote sensing, statistical evaluation

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Authors: Mila Fantinelli

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Cairo is the perfect modern representation of a living hell between rising temperatures and failing architecture. The works of Egyptian writer Mohamed Makhzangi may prove to add more depth to the debate that surrounds the topic of pollution in Arab literature. This Egyptian writer, who studied medicine and psychiatry before dedicating his life to writing, sheds indeed further light on the ecological condition of Cairo. In relation to this, the short story “The breeze hunter” (2018) tackles the topic of “environmental architecture”, citing the research of Hassan Fathy in “Architecture for the Poor: An Experiment in Rural Egypt” which provides examples from history of inventions to counter the effects of the hot weather. Specifically, the main character of the story is a man living in Cairo in a small apartment, which turns into a living hell in the summer season because of the high temperatures. Catastrophic urban planning, therefore, prevents the mitigation of the torrid climate but rather worsens it. Makhzangi indeed refers to the environmental issue of pollution caused by the excessive number of air conditioners, which transform Cairo into an infernal island of heat while our country becomes warmer with the passing of time. His description of the city already intersects ecocriticism and environmental issues, tackling the topic of pollution inside of cities and the impact of climate change, of which Cairo is a perfect example. History has indeed provided ways in order to reduce the heat inside houses. Yet, these have all been ignored. As a result, through the teachings of Hassan Fathy, the narrator of the story builds an opening in the house to catch the natural breeze coming from the north. He, therefore, becomes the breeze hunter of Mansoura. However, polluted waves interrupt this brief rest, thus leading to a worsening of his conditions, leading to him suffering from the effects of crowding and the consequences of climate change and pollution. Makhzangi, therefore, reflects on how architecture and urbanism affect the psychological sanity of people and how the situation is worsened by the catastrophic consequences of climate change and pollution.

Keywords: ecocriticism, Arabic literature, pollution, environmental architecture, crowding

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Authors: Gabrielle O'Donoghue

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Background: Pre-operative radiographs facilitate assessment and treatment planning in minor oral surgery. Quality assurance for dental radiography advocates the As Low As Reasonably Achievable (ALARA) principle in collecting accurate diagnostic information. Aims: To audit the quality of digital intraoral periapicals (IOPAs) taken prior to dental extractions in a metropolitan general dental practice setting. Standards: The National Radiological Protection Board (NRPB) guidance outlines three grades of radiograph quality: excellent (Grade 1 > 70% of total exposures), diagnostically acceptable (Grade 2 <20%), and unacceptable (Grade 3 <10%). Methodology: A study of pre-operative radiographs taken prior to dental extractions across 12 private general dental practices in a large metropolitan area by 44 practitioners. A total of 725 extractions were assessed, allowing 258 IOPAs to be reviewed in one audit cycle. Results: First cycle: Of 258 IOPAs: 223(86.4%) scored Grade 1, 27(10.5%) Grade 2, and 8(3.1%) Grade 3. The standard was met. 35 dental extractions were performed without an available pre-operative radiograph. Action Plan & Recommendations: Results were distributed to all staff and a continuous professional development evening organized to outline recommendations to improve image quality. A second audit cycle is proposed at a six-month interval to review the recommendations and appraise results. Conclusion: The overall standard of radiographs met the published guidelines. A significant improvement in the number of procedures undertaken without pre-operative imaging is expected at a six-month interval period. An investigation into undiagnostic imaging and associated adverse patient outcomes is being considered. Maintenance of the standards achieved is predicted in the second audit cycle to ensure consistent high quality imaging.

Keywords: audit, oral radiology, oral surgery, periapical radiographs, quality assurance

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Authors: Darwin Castillo Huamaní, Francisco A. M. Gomes

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The aim of the multi-material topology optimization (MTO) is to obtain the optimal topology of structures composed by many materials, according to a given set of constraints and cost criteria. In this work, we seek the optimal distribution of materials in a domain, such that the flexibility of the structure is minimized, under certain boundary conditions and the intervention of external forces. In the case we have only one material, each point of the discretized domain is represented by two values from a function, where the value of the function is 1 if the element belongs to the structure or 0 if the element is empty. A common way to avoid the high computational cost of solving integer variable optimization problems is to adopt the Solid Isotropic Material with Penalization (SIMP) method. This method relies on the continuous interpolation function, power function, where the base variable represents a pseudo density at each point of domain. For proper exponent values, the SIMP method reduces intermediate densities, since values other than 0 or 1 usually does not have a physical meaning for the problem. Several extension of the SIMP method were proposed for the multi-material case. The one that we explore here is the ordered SIMP method, that has the advantage of not being based on the addition of variables to represent material selection, so the computational cost is independent of the number of materials considered. Although the number of variables is not increased by this algorithm, the optimization subproblems that are generated at each iteration cannot be solved by methods that rely on second derivatives, due to the cost of calculating the second derivatives. To overcome this, we apply a globally convergent version of the sequential linear programming method, which solves a linear approximation sequence of optimization problems.

Keywords: globally convergence, multi-material design ordered simp, sequential linear programming, topology optimization

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Authors: K. M. R. Siriwardhana

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Sri Lanka is a developing country in South Asia which uses English as its second language. Today, most of the university students in Sri Lanka are eagerly exploring knowledge giving special consideration to English as their 2nd Language with the understanding that to climb up the career ladder, English is inevitable both in local and international contexts. However, still a considerable failing rate in English can also be seen among the Sri Lankan undergraduates Further, most of the Sri Lankan universities now practice English as their medium of instructions making English a credited Subject to brighten the future of the Sri Lankan students. Accordingly, in many universities an array of assessments are employed to evaluate undergraduates’ competence in English language. The main objective of this study was to ascertain the effective assessment methods to improve the 2nd language skills of the Sri Lankan university students which also create a more interest in them to learn English. Accordingly, hundred (100) undergraduates were selected as the research sample and the primary data was collected employing a semi structured questionnaire along with class room observations and semi structured interviews. Data was mainly analyzed descriptively employing graphical illustrations. According to the research findings, it was revealed that practical assessments such as oral tests, competitive drama and presentations are more effective in improving their language skills and preferred by the majority of students than written assignments and papers. Further, most of the students have scored better in practical assignments than in the written assignments. Hence, the study concludes that best and the benefited way of improving English language skills of Sri Lankan undergraduates is practical assessments as it gives them the opportunity to apply the language with much confidence and competence in actual situations. Further, the study recommends the language teachers to improve their own skills and creativity in practicing and employing such assessments as it will develop both second language teaching and learning skills. Ultimately, the university graduates will be able to secure their positions internationally as they are well capable in English, the lingua franca of the world.

Keywords: assessments, second language, Sri Lanka, undergraduates

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Authors: Ayedun Hassan, Ayadi Odunayo Peter

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The ancient city of Abeokuta has been supplied with pipe borne water since 1911, yet, a continuous increase in population and unplanned city expansion makes water a very precious and scarce commodity. The government reserved areas (GRA’s) are well planned, and public water supply is available; however, the sub-urban areas consist of scattered structures with individuals trying to source water by digging wells and boreholes. The geology of the city consists of basement rock which makes digging wells and boreholes very difficult. The present study was conducted to assess the risk arising from the consumption of toxic elements in the groundwater of Abeokuta, Ogun State, Nigeria. Forty-five groundwater samples were collected from nine different areas of Abeokuta and analyzed for physicochemical parameters and toxic elements. The physicochemical parameters were determined using standard methods, while the toxic elements were determined using Inductively Coupled Plasma-Mass Spectrometer (ICP/MS). Ninety-six percent (96%) of the water sample has pH < 6.5, and 11% has conductivity > 250 µSCm⁻¹ limits in drinking water as recommended by WHO. Seven percent (7%) of the samples have Pb concentration >10 µgL⁻¹ while 75% have Al concentration >200 µgL⁻¹ recommended by WHO. The order for risk of cancer from different area of Abeokuta are Cd²⁺ > As³⁺ > Pb²⁺ > Cr⁶⁺ for Funaab, Camp and Obantoko; As³⁺ > Cd²⁺ > Pb²⁺ > Cr⁶⁺ for Ita Osin, Isale Igbein, Ake and Itoku; Cd²⁺ >As > Cr⁶⁺ > Pb²⁺ for Totoro; Pb²⁺ > Cd²⁺ > As³⁺ > Cr⁶⁺ for Idiaba. The order of non-cancer hazard index (HI) calculated for groundwater of Abeokuta City are Cd²⁺ > As³⁺ > Mn²⁺ > Pb²⁺ > Ni²⁺ and were all greater than one, which implies susceptibility to other illnesses. The sources of these elements are the rock and inappropriate waste disposal method, which leached the elements into the groundwater. A combination of sources from food will accumulate these elements in the human body system. Treatment to remove Al and Pb is necessary, while the method of water distribution should be reviewed to ensure access to potable water by the residents.

Keywords: Abeokuta, groundwater, Nigeria, risk

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Authors: Getaneh Berie Tarekegn

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A precise localization system is crucial for many artificial intelligence Internet of Things (AI-IoT) applications in the era of smart cities. Their applications include traffic monitoring, emergency alarming, environmental monitoring, location-based advertising, intelligent transportation, and smart health care. The most common method for providing continuous positioning services in outdoor environments is by using a global navigation satellite system (GNSS). Due to nonline-of-sight, multipath, and weather conditions, GNSS systems do not perform well in dense urban, urban, and suburban areas.This paper proposes a generative AI-based positioning scheme for large-scale wireless settings using fingerprinting techniques. In this article, we presented a semi-supervised deep convolutional generative adversarial network (S-DCGAN)-based radio map construction method for real-time device localization. It also employed a reliable signal fingerprint feature extraction method with t-distributed stochastic neighbor embedding (t-SNE), which extracts dominant features while eliminating noise from hybrid WLAN and long-term evolution (LTE) fingerprints. The proposed scheme reduced the workload of site surveying required to build the fingerprint database by up to 78.5% and significantly improved positioning accuracy. The results show that the average positioning error of GAILoc is less than 0.39 m, and more than 90% of the errors are less than 0.82 m. According to numerical results, SRCLoc improves positioning performance and reduces radio map construction costs significantly compared to traditional methods.

Keywords: location-aware services, feature extraction technique, generative adversarial network, long short-term memory, support vector machine

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Authors: C. Yin, B. Zhang, Y. Liu, J. Cai

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Airborne EM (AEM) is an effective geophysical exploration tool, especially suitable for ridged mountain areas. In these areas, topography will have serious effects on AEM system responses. However, until now little study has been reported on topographic effect on airborne EM systems. In this paper, an edge-based unstructured finite-element (FE) method is developed for 3D topographic modeling for both frequency and time-domain airborne EM systems. Starting from the frequency-domain Maxwell equations, a vector Helmholtz equation is derived to obtain a stable and accurate solution. Considering that the AEM transmitter and receiver are both located in the air, the scattered field method is used in our modeling. The Galerkin method is applied to discretize the Helmholtz equation for the final FE equations. Solving the FE equations, the frequency-domain AEM responses are obtained. To accelerate the calculation speed, the response of source in free-space is used as the primary field and the PARDISO direct solver is used to deal with the problem with multiple transmitting sources. After calculating the frequency-domain AEM responses, a Hankel’s transform is applied to obtain the time-domain AEM responses. To check the accuracy of present algorithm and to analyze the characteristic of topographic effect on airborne EM systems, both the frequency- and time-domain AEM responses for 3 model groups are simulated: 1) a flat half-space model that has a semi-analytical solution of EM response; 2) a valley or hill earth model; 3) a valley or hill earth with an abnormal body embedded. Numerical experiments show that close to the node points of the topography, AEM responses demonstrate sharp changes. Special attentions need to be paid to the topographic effects when interpreting AEM survey data over rugged topographic areas. Besides, the profile of the AEM responses presents a mirror relation with the topographic earth surface. In comparison to the topographic effect that mainly occurs at the high-frequency end and early time channels, the EM responses of underground conductors mainly occur at low frequencies and later time channels. For the signal of the same time channel, the dB/dt field reflects the change of conductivity better than the B-field. The research of this paper will serve airborne EM in the identification and correction of the topographic effects.

Keywords: 3D, Airborne EM, forward modeling, topographic effect

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Authors: Eman M. Sarhan, Doaa A. Ghareeb, Gabriella Ortore, Amr A. Amara, Mohamed M. El-Sayed

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Drug salting and nanoparticle-based drug delivery formulations are considered to be an effective means for rendering the hydrophobic drugs’ nano-scale dispersion in aqueous media, and thus circumventing the pitfalls of their poor solubility as well as enhancing their membrane permeability. The current study aims to increase the bioavailability of quaternary ammonium berberine through acid salting and biodegradable bovine serum albumin (BSA)-based nanoparticulate drug formulation. Berberine hydroxide (BBR-OH) that was chemically synthesized by alkalization of the commercially available berberine hydrochloride (BBR-HCl) was then acidified to get Di-berberine sulfate (BBR)₂SO₄. The purified crystals were spectrally characterized. The desolvation technique was optimized for the preparation of size-controlled BSA-BBR-HCl, BSA-BBR-OH, and BSA-(BBR)₂SO₄ nanoparticles. Particle size, zeta potential, drug release, encapsulation efficiency, Fourier transform infrared spectroscopy (FTIR), tandem MS-MS spectroscopy, energy-dispersive X-ray spectroscopy (EDX), scanning and transmitting electron microscopic examination (SEM, TEM), in vitro bioactivity, and in silico drug-polymer interaction were determined. BSA (PDB ID; 4OR0) protonation state at different pH values was predicted using Amber12 molecular dynamic simulation. Then blind docking was performed using Lamarkian genetic algorithm (LGA) through AutoDock4.2 software. Results proved the purity and the size-controlled synthesis of berberine-BSA-nanoparticles. The possible binding poses, hydrophobic and hydrophilic interactions of berberine on BSA at different pH values were predicted. Antioxidant, anti-hemolytic, and cell differentiated ability of tested drugs and their nano-formulations were evaluated. Thus, drug salting and the potentially effective albumin berberine nanoparticle formulations can be successfully developed using a well-optimized desolvation technique and exhibiting better in vitro cellular bioavailability.

Keywords: berberine, BSA, BBR-OH, BBR-HCl, BSA-BBR-HCl, BSA-BBR-OH, (BBR)₂SO₄, BSA-(BBR)₂SO₄, FTIR, AutoDock4.2 Software, Lamarkian genetic algorithm, SEM, TEM, EDX

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Authors: M. Cabrera, W. Tizani, J. Ninic, F. Wang

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Open section beam to concrete-filled tubular column structures has been increasingly utilized in construction over the past few decades due to their enhanced structural performance, as well as economic and architectural advantages. However, the use of this configuration in construction is limited due to the difficulties in connecting the structural members as there is no access to the inner part of the tube to install standard bolts. Blind-bolted systems are a relatively new approach to overcome this limitation as they only require access to one side of the tubular section to tighten the bolt. The performance of these connections in concrete-filled steel tubular sections remains uncharacterized due to the complex interactions between concrete, bolt, and steel section. Over the last years, research in structural performance has moved to a more sophisticated and efficient approach consisting of machine learning algorithms to generate metamodels. This method reduces the need for developing complex, and computationally expensive finite element models, optimizing the search for desirable design variables. Metamodels generated by a data fusion approach use numerical and experimental results by combining multiple models to capture the dependency between the simulation design variables and connection performance, learning the relations between different design parameters and predicting a given output. Fully characterizing this connection will transform high-rise and multistorey construction by means of the introduction of design guidance for moment-resisting blind-bolted connections, which is currently unavailable. This paper presents a review of the steps taken to develop metamodels generated by means of artificial neural network algorithms which predict the connection stress and stiffness based on the design parameters when using Extended Hollo-Bolt blind bolts. It also provides consideration of the failure modes and mechanisms that contribute to the deformability as well as the feasibility of achieving blind-bolted rigid connections when using the blind fastener.

Keywords: blind-bolted connections, concrete-filled tubular structures, finite element analysis, metamodeling

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Authors: S. Daneshi, G. Shahcheraghi, F. Ghaffarinejad

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Back ground: Osteoarthritis (OA) is the most common form of arthritis, affecting millions of people around the world during the aging process. Knee joint proprioception sense decrease with OA and Total Knee Arthroplasty (TKA) surgery may affect them. We investigated two parameters of proprioception sense (the joint position sense and kinesthesia) and standing balance in affected limbs before and after TKA, in patient with Knee OA. Methods and Materials: In this Analytic study, 10 patients who were candidate for TKA during two months in Dena Hospital of Shiraz, selected for further analysis. All of cases were female in range of 55-70 years old. Participants assessed before and two weeks after TKA using three instruments: electrogoniometer and continuous passive motion (CPM) to assess Knee joint position sense and kinesthesia in 20 and 45 degrees; and chronometer to assess duration of standing balance on affected leg with open and closed eyes. Results: To examine differences between before and after of TKA scorings Willcoxon Signed Rank and Mann-Whitney was performed which indicated no significant differences between knee joint position sense and kinesthesia in 20 and 45 degrees (P>0.05) and no significant differences between Standing Balance in a patient with knee OA before and after TKA (P>0.05). Conclusion: The study indicates that, OA can affect proprioception sense and standing balance but TKA doesn’t have any effect on these parameters. Intra articular structures such as cruciate ligaments and mines are responsible for proprioception sense in normal knee joint. Since in severe knee OA the number of mechanoreceptors in these intra articular structures decrease and their function reduce more than normal knee joint, so the anterior cruciate ligaments (ACL) become defected, thus after TKA surgery which this ligament is removed no significant change was found in proprioception sense. As a result of involving proprioception sense, muscles strength and the function of vestibular system in balance, standing balance did not show significant difference before and after TKA.

Keywords: knee joint, proprioception sense, standing balance, rehabilitation sciences

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Authors: Gláucio de Castro Júnior, Daniela Prometi, Patrícia Tuxi

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The project 'Inventory Signs-terms of the cultural heritage field in Libras' provides for the establishment of an inventory of signs, terms relating to the field of cultural heritage in Libras, from the results of research in progress as the pilot project' Accessibility Communication, Translation and Interpretation to the Application Portal Libras Heritage 'and the Pilot Project' registration-signal terms for the preparation of bilingual lexicon Libras / Portuguese terms available in the Portal Heritage. The project's goal is to spread the lexicographical rules on the use of technologies in video graphic records of sign language and foster the training of undergraduate students and graduate to the registration of the linguistic diversity of Libras through social and communicative interaction with the community deaf and enable access to Deaf information relating to the field of cultural heritage in Libras. As a result, we expect the spread of the inventory of cultural heritage-signs in terms Libras in application usage 'Portal Heritage'. To achieve the proposed objectives are accomplished technical consulting and continuous training for the production of academic material through theoretical and practical meetings, taught by experts Libras LIP / UNB in partnership with some institutions. The Inventory project signals-Terms under Heritage in Libras field initially took place in Rio de Janeiro in order to allow its development in the Midwest region, due to technical, elected some cities in Brazil, including Manaus in Amazon Macapa in Amapa, Salvador Bahia, Goiás and Goiânia in Florianopolis in Santa Catarina. At the end of all this process, the assessment by preparing a technical report presenting all the advances and points achieved in the project looking for social improvement, economic, environmental and language in the use of technology will be conducted.

Keywords: signs-terms, equity-cultural accessibility, technology, sign language

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Authors: Yazeed Al-Sheikh

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Pregnancy represents a risk factor in the occurrence of vulvovaginal candidiasis. To investigate the prevalence rate of vaginal carriage of Candida species in Saudi pregnant and non-pregnant women, high vaginal swab (HVS) specimens (707) were examined by direct microscopy (10% KOH and Giemsa staining) and parallel cultured on Sabouraud Dextrose Agar (SDA) as well as on “CHROM agar Candida” medium. As expected, Candida-positive cultures were frequently observed in pregnant-test group (24%) than in non-pregnant group (17%). The frequency of culture positive was correlated to pregnancy (P=0.047), parity (P=0.001), use of contraceptive (P=0.146), or antibiotics (P=0.128), and diabetic-patients (P < 0.0001). Out of 707 HVS examined specimens, 157 specimens were yeast-positive culture (22%) on Sabouraud Dextrose Agar or “CHROM agar Candida”. In comparison, the sensitivities of the direct 10% KOH and the Giemsa stain microscopic examination methods were 84% (132/157) and 95% (149/157) respectively but both with 100% specificity. As for the identity of recovered 157 yeast isolates, based on API 20C biotype carbohydrate assimilation, germ tube and chlamydospore formation, C. albicansand C. glabrata constitute 80.3 and 12.7% respectively. Rates of C. tropicalis, C. kefyr, C. famata or C. utilis were 2.6, 1.3, and 0.6% respectively. Sachromyces cerevisiae and Rhodotorula mucilaginosa yeasts were also encountered at a frequency of 1.3 and 0.6% respectively. Finally, among all recovered 157 yeast-isolates, strains resistant to ketoconazole were not detected, whereas 5% of the C. albicans and as high as 55% of the non-albicans yeast isolates (majority C. glabrata) showed resistance to fluconazole. Our findings may prove helpful for continuous determination of the existing vaginal candidiasis causative species during pregnancy, its lab-diagnosis and/or control and possible measures to minimize the incidence of the disease-associated pre-term delivery.

Keywords: vaginal candidiasis, Candida spp., pregnancy, risk factors, API 20C-yeast biotypes, giemsa stain, antifungal agents

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Authors: Amro Matyori, Fatimah Sherbeny, Askal Ali, Olayiwola Popoola

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Objectives: The study evaluated the impact of COVID-19 on anxiety levels in the general population in the United States. Methods: The study used an online questionnaire. It adopted the Generalized Anxiety Disorder Assessment (GAD-7) instrument. It is a self-administered scale with seven items used as a screening tool and severity measure for generalized anxiety disorder. The participants rated the frequency of anxiety symptoms in the last two weeks on a Likert scale, which ranges from 0-3. Then the item points are summed to provide the total score. Results: Thirty-two participants completed the questionnaire. Among them, 24 (83%) females and 5 (17%) males. The age range of 18-24-year-old represented the most respondents. Only one of the participants tested positive for the COVID-19, and 39% of them, one of their family members, friends, or colleagues, tested positive for the coronavirus. Moreover, 10% have lost a family member, a close friend, or a colleague because of COVID-19. Among the respondents, there were ten who scored approximately five points on the GAD-7 scale, which indicates mild anxiety. Furthermore, eight participants scored 10 to 14 points, which put them under the category of moderate anxiety, and one individual who was categorized under severe anxiety scored 15 points. Conclusions: It is identified that most of the respondents scored the points that put them under the mild anxiety category during the COVID-19 pandemic. It is also noticed that severe anxiety was the lowest among the participants, and people who tested positive and/or their family members, close friends, and colleagues were more likely to experience anxiety. Additionally, participants who lost friends or family members were also at high risk of anxiety. It is obvious the COVID-19 outcomes and too much thinking about the pandemic put people under stress which led to anxiety. Therefore, continuous assessment and monitoring of psychological outcomes during pandemics will help to establish early well-informed interventions.

Keywords: anxiety and covid-19, covid-19 and mental health outcomes, influence of covid-19 on anxiety, population and covid-19 impact on mental health

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Authors: Yebeen Ji, Jimin Yun, Kwonhoo Kim

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Magnesium alloys were limited for industrial applications due to having a limited slip system and high plastic anisotropy. It has been known that specific textures were formed during processing (rolling, etc.), and These textures cause poor formability. To solve these problems, many researchers have studied controlling texture by adding rare-earth elements. However, the high cost limits their use; therefore, alternatives are needed to replace them. Although Pb addition doesn’t directly improve magnesium properties, it has been known to suppress the diffusion of other alloying elements and reduce grain boundary energy. These characteristics are similar to the additions of rare-earth elements, and a similar texture behavior is expected as well. However, there is insufficient research on this. Therefore, this study investigates the behavior of texture and microstructure development after adding Pb to magnesium. This study compared and analyzed AZ61 alloy and Mg-15wt%Pb alloy to determine the effect of adding solute elements. The alloy was hot rolled and annealed to form a single phase and initial texture. Afterward, the specimen was set to contraction and elongate parallel to the rolling surface and the rolling direction and then subjected to high-temperature plane strain compression under the conditions of 723K and 0.05/s. Microstructural analysis and texture measurements were performed by SEM-EBSD. The peak stress in the true strain-stress curve after compression was higher in AZ61, but the shape of the flow curve was similar for both alloys. For both alloys, continuous dynamic recrystallization was confirmed to occur during the compression process. The basal texture developed parallel to the compressed surface, and the pole density was lower in the Mg-15wt%Pb alloy. It is confirmed that this change in behavior is because the orientation distribution of recrystallized grains has a more random orientation compared to the parent grains when Pb is added.

Keywords: Mg, texture, Pb, DRX

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