Search results for: measuring stress
1167 Indoleamines (Serotonin & Melatonin) in Edible Plants: Its Influence on Human Health
Authors: G. A. Ravishankar, A. Ramakrishna
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Melatonin (MEL) and Serotonin (SER), also known as [5-Hydroxytryptamine (5-HT)] are reported to be in a range of plant types which are edible. Their occurrence in plants species appears to be ubiquitous. Their presence in high quantities in plants assumes significance owing to their physiological effects upon consumption by human beings. MEL is a well known animal hormone mainly released by the pineal gland known to influence circadian rhythm, sleep, apart from immune enhancement. Similarly, SER is a neurotransmitter that regulates mood, sleep and anxiety in mammals. It is implicated in memory, behavioral changes, scavenging reactive oxygen species, antipsychotic, etc. Similarly Role of SER and MEL in plant morphogenesis, and various physiological processes through intense research is beginning to unfold. These molecules are in common foods viz banana, pineapple, plum, nuts, milk, grape wine. N- Feruloyl serotonin and p-coumaroyl serotonin found in certain seeds are found to possess antioxidant, anti-inflammatory, antitumor, antibacterial, and anti-stress potential apart from reducing depression and anxiety. MEL is found in Mediterranean diets, nuts, cherries, tomato berries, and olive products. Consumption of foods rich in MEL is known to increase blood MEL levels which have been implicated in protective effect against cardiovascular damage, cancer initiation and growth. MEL is also found in wines, green tea, beer, olive oil etc. Moreover, presence of SER and MEL in Coffee beans (green and roasted beans) and decoction has been reported us. In this communication we report the occurrence of indole amines in edible plants and their implications in human health.Keywords: serotonin, melatonin, edible plants, neurotransmitters, physiological effects
Procedia PDF Downloads 2791166 Assessing Perinatal Mental Illness during the COVID-19 Pandemic: A Review of Measurement Tools
Authors: Mya Achike
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Background and Significance: Perinatal mental illness covers a wide range of conditions and has a huge influence on maternal-child health. Issues and challenges with perinatal mental health have been associated with poor pregnancy, birth, and postpartum outcomes. It is estimated that one out of five new and expectant mothers experience some degree of perinatal mental illness, which makes this a hugely significant health outcome. Certain factors increase the maternal risk for mental illness. Challenges related to poverty, migration, extreme stress, exposure to violence, emergency and conflict situations, natural disasters, and pandemics can exacerbate mental health disorders. It is widely expected that perinatal mental health is being negatively affected during the present COVID-19 pandemic. Methods: A review of studies that reported a measurement tool to assess perinatal mental health outcomes during the COVID-19 pandemic was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, CINAHL, and Google Scholar were used to search for peer-reviewed studies published after late 2019, in accordance with the emergence of the virus. The search resulted in the inclusion of ten studies. Approach to measure health outcome: The main approach to measure perinatal mental illness is the use of self-administered, validated questionnaires, usually in the clinical setting. Summary: Widespread use of these tools has afforded the clinical and research communities the ability to identify and support women who may be suffering from mental illness disorders during a pandemic. More research is needed to validate tools in other vulnerable, perinatal populations.Keywords: mental health during covid, perinatal mental health, perinatal mental health measurement tools, perinatal mental health tools
Procedia PDF Downloads 1351165 Measurement of in-situ Horizontal Root Tensile Strength of Herbaceous Vegetation for Improved Evaluation of Slope Stability in the Alps
Authors: Michael T. Lobmann, Camilla Wellstein, Stefan Zerbe
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Vegetation plays an important role for the stabilization of slopes against erosion processes, such as shallow erosion and landslides. Plant roots reinforce the soil, increase soil cohesion and often cross possible shear planes. Hence, plant roots reduce the risk of slope failure. Generally, shrub and tree roots penetrate deeper into the soil vertically, while roots of forbs and grasses are concentrated horizontally in the topsoil and organic layer. Therefore, shrubs and trees have a higher potential for stabilization of slopes with deep soil layers than forbs and grasses. Consequently, research mainly focused on the vertical root effects of shrubs and trees. Nevertheless, a better understanding of the stabilizing effects of grasses and forbs is needed for better evaluation of the stability of natural and artificial slopes with herbaceous vegetation. Despite the importance of vertical root effects, field observations indicate that horizontal root effects also play an important role for slope stabilization. Not only forbs and grasses, but also some shrubs and trees form tight horizontal networks of fine and coarse roots and rhizomes in the topsoil. These root networks increase soil cohesion and horizontal tensile strength. Available methods for physical measurements, such as shear-box tests, pullout tests and singular root tensile strength measurement can only provide a detailed picture of vertical effects of roots on slope stabilization. However, the assessment of horizontal root effects is largely limited to computer modeling. Here, a method for measurement of in-situ cumulative horizontal root tensile strength is presented. A traction machine was developed that allows fixation of rectangular grass sods (max. 30x60cm) on the short ends with a 30x30cm measurement zone in the middle. On two alpine grass slopes in South Tyrol (northern Italy), 30x60cm grass sods were cut out (max. depth 20cm). Grass sods were pulled apart measuring the horizontal tensile strength over 30cm width over the time. The horizontal tensile strength of the sods was measured and compared for different soil depths, hydrological conditions, and root physiological properties. The results improve our understanding of horizontal root effects on slope stabilization and can be used for improved evaluation of grass slope stability.Keywords: grassland, horizontal root effect, landslide, mountain, pasture, shallow erosion
Procedia PDF Downloads 1661164 The Psychometric Properties of the Team Climate Inventory Scale: A Validation Study in Jordan’s Collectivist Society
Authors: Suhair Mereish
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This research is aimed at examining the climate for innovation in organisations with the aim of validating the psychometric properties of the Team Climate Inventory (TCI -14) for Jordan’s collectivist society. The innovativeness of teams may be improved or obstructed by the climate within the team. Further, personal factors are considered an important element that influences the climate for innovation. Accordingly, measuring the employees' personality traits using the Big Five Inventory (BFI-44) could provide insights that aid in understanding how to improve innovation. Thus, studying the climate for innovation and its associations with personality traits is valuable, considering the insights it could offer on employee performance, job satisfaction, and well-being. Essentially, the Team Climate Inventory instrument has never been tested in Jordan’s collectivist society. Accordingly, in order to address the existing gap in the literature as a whole and, more specifically, in Jordan, it is essential to investigate its factorial structure and reliability in this particular context. It is also important to explore whether the factorial structure of the Team Climate Inventory in Jordan’s collectivist society demonstrates a similar or different structure to what has been found in individualistic ones. Lastly, examining if there are associations between the Team Climate Inventory and personality traits of Jordanian employees is pivotal. The quantitative study was carried out among Jordanian employees employed in two of the top 20 companies in Jordan, a shipping and logistics company (N=473) and a telecommunications company (N=219). To generalise the findings, this was followed by collecting data from the general population of this country (N=399). The participants completed the Team Climate Inventory. Confirmatory factor analyses and reliability tests were conducted to confirm the factorial structure, validity, and reliability of the inventory. Findings presented that the four-factor structure of the Team Climate Inventory in Jordan revealed a similar structure to the ones in Western culture. The four-factor structure has been confirmed with good fit indices and reliability values. Moreover, for climate for innovation, regression analysis identified agreeableness (positive) and neuroticism (negative) from the Big Five Inventory as significant predictors. This study will contribute to knowledge in several ways. First, by examining the reliability and factorial structure in a Jordanian collectivist context rather than a Western individualistic one. Second, by comparing the Team Climate Inventory structure in Jordan with findings for the Team Climate Inventory from Western individualistic societies. Third, by studying its relationships with personality traits in that country. Furthermore, findings from this study will assist practitioners in the field of organisational psychology and development to improve the climate for innovation for employees working in organisations in Jordan. It is also expected that the results of this research will provide recommendations to professionals in the business psychology sector regarding the characteristics of employees who hold positive and negative perceptions of the workplace climate.Keywords: big five inventory, climate for innovation, collectivism, individualism, Jordan, team climate inventory
Procedia PDF Downloads 601163 Development of Structural Deterioration Models for Flexible Pavement Using Traffic Speed Deflectometer Data
Authors: Sittampalam Manoharan, Gary Chai, Sanaul Chowdhury, Andrew Golding
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The primary objective of this paper is to present a simplified approach to develop the structural deterioration model using traffic speed deflectometer data for flexible pavements. Maintaining assets to meet functional performance is not economical or sustainable in the long terms, and it would end up needing much more investments for road agencies and extra costs for road users. Performance models have to be included for structural and functional predicting capabilities, in order to assess the needs, and the time frame of those needs. As such structural modelling plays a vital role in the prediction of pavement performance. A structural condition is important for the prediction of remaining life and overall health of a road network and also major influence on the valuation of road pavement. Therefore, the structural deterioration model is a critical input into pavement management system for predicting pavement rehabilitation needs accurately. The Traffic Speed Deflectometer (TSD) is a vehicle-mounted Doppler laser system that is capable of continuously measuring the structural bearing capacity of a pavement whilst moving at traffic speeds. The device’s high accuracy, high speed, and continuous deflection profiles are useful for network-level applications such as predicting road rehabilitations needs and remaining structural service life. The methodology adopted in this model by utilizing time series TSD maximum deflection (D0) data in conjunction with rutting, rutting progression, pavement age, subgrade strength and equivalent standard axle (ESA) data. Then, regression analyses were undertaken to establish a correlation equation of structural deterioration as a function of rutting, pavement age, seal age and equivalent standard axle (ESA). This study developed a simple structural deterioration model which will enable to incorporate available TSD structural data in pavement management system for developing network-level pavement investment strategies. Therefore, the available funding can be used effectively to minimize the whole –of- life cost of the road asset and also improve pavement performance. This study will contribute to narrowing the knowledge gap in structural data usage in network level investment analysis and provide a simple methodology to use structural data effectively in investment decision-making process for road agencies to manage aging road assets.Keywords: adjusted structural number (SNP), maximum deflection (D0), equant standard axle (ESA), traffic speed deflectometer (TSD)
Procedia PDF Downloads 1511162 Characteristics of Double-Stator Inner-Rotor Axial Flux Permanent Magnet Machine with Rotor Eccentricity
Authors: Dawoon Choi, Jian Li, Yunhyun Cho
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Axial Flux Permanent Magnet (AFPM) machines have been widely used in various applications due to their important merits, such as compact structure, high efficiency and high torque density. This paper presents one of the most important characteristics in the design process of the AFPM device, which is a recent issue. To design AFPM machine, the predicting electromagnetic forces between the permanent magnets and stator is important. Because of the magnitude of electromagnetic force affects many characteristics such as machine size, noise, vibration, and quality of output power. Theoretically, this force is canceled by the equilibrium of force when it is in the middle of the gap, but it is inevitable to deviate due to manufacturing problems in actual machine. Such as large scale wind generator, because of the huge attractive force between rotor and stator disks, this is more serious in getting large power applications such as large. This paper represents the characteristics of Double-Stator Inner –Rotor AFPM machines when it has rotor eccentricity. And, unbalanced air-gap and inclined air-gap condition which is caused by rotor offset and tilt in a double-stator single inner-rotor AFPM machine are each studied in electromagnetic and mechanical aspects. The output voltage and cogging torque under un-normal air-gap condition of AF machines are firstly calculated using a combined analytical and numerical methods, followed by a structure analysis to study the effect to mechanical stress, deformation and bending forces on bearings. Results and conclusions given in this paper are instructive for the successful development of AFPM machines.Keywords: axial flux permanent magnet machine, inclined air gap, unbalanced air gap, rotor eccentricity
Procedia PDF Downloads 2191161 Bank Internal Controls and Credit Risk in Europe: A Quantitative Measurement Approach
Authors: Ellis Kofi Akwaa-Sekyi, Jordi Moreno Gené
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Managerial actions which negatively profile banks and impair corporate reputation are addressed through effective internal control systems. Disregard for acceptable standards and procedures for granting credit have affected bank loan portfolios and could be cited for the crises in some European countries. The study intends to determine the effectiveness of internal control systems, investigate whether perceived agency problems exist on the part of board members and to establish the relationship between internal controls and credit risk among listed banks in the European Union. Drawing theoretical support from the behavioural compliance and agency theories, about seventeen internal control variables (drawn from the revised COSO framework), bank-specific, country, stock market and macro-economic variables will be involved in the study. A purely quantitative approach will be employed to model internal control variables covering the control environment, risk management, control activities, information and communication and monitoring. Panel data from 2005-2014 on listed banks from 28 European Union countries will be used for the study. Hypotheses will be tested and the Generalized Least Squares (GLS) regression will be run to establish the relationship between dependent and independent variables. The Hausman test will be used to select whether random or fixed effect model will be used. It is expected that listed banks will have sound internal control systems but their effectiveness cannot be confirmed. A perceived agency problem on the part of the board of directors is expected to be confirmed. The study expects significant effect of internal controls on credit risk. The study will uncover another perspective of internal controls as not only an operational risk issue but credit risk too. Banks will be cautious that observing effective internal control systems is an ethical and socially responsible act since the collapse (crisis) of financial institutions as a result of excessive default is a major contagion. This study deviates from the usual primary data approach to measuring internal control variables and rather models internal control variables in a quantitative approach for the panel data. Thus a grey area in approaching the revised COSO framework for internal controls is opened for further research. Most bank failures and crises could be averted if effective internal control systems are religiously adhered to.Keywords: agency theory, credit risk, internal controls, revised COSO framework
Procedia PDF Downloads 3171160 Chronic Pesticides Exposure and Certain Endocrine Functions Among Farmers in East Almnaif District, Ismailia, Egypt
Authors: Amani Waheed, Mostafa Kofi, Shaymaa Attia, Soha Younis, Basma Abdel Hadi
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Background: Exposure to pesticides is one of the most important occupational risks among farmers in developing countries. Along with the wide use of pesticides in the world, the concerns over their health impacts are rapidly growing. Objective: To investigate thyroid and reproductive hormones and fasting blood glucose levels among farmers chronically exposed to pesticide from East Almnaif district, Ismailia governorate. Methods: An analytical cross-sectional study was conducted on 43 farmers with active involvement pesticides handling and 43 participants not occupationally exposed to pesticides as the control group. A structured interview questionnaire measuring the sociodemographic characteristics, pesticides exposure characteristics, and safety measures was used. General examination including measurements of height, weight, and blood pressure was done. Moreover, levels of plasma cholinesterase enzyme (PChE), glucose, as well as reproductive and thyroid hormones (TSH, T4, and testosterone) were determined. Results: There were no statistically significant differences between both groups regarding their age, educational level, smoking status, and body mass index. The mean duration of exposure was 20.60 11.06 years. Majority of farmers (76.7%) did not use any personal protective equipment (PPE) during pesticides handling. The mean systolic blood pressure among exposed farmers was greater (134.88 17.18 mm Hg) compared to control group (125 14.69 mm Hg) with statistically significant difference (p = 0.003). The mean diastolic blood pressure was higher (84.02 8.69 mm Hg) compared to control group (78.79 8.98 mm Hg) with statistically significant difference (p = 0.006). The pesticide exposed farmers had statistically significant lower level of PChE (3969.93 1841U/L) than control group (4879.29 1950.08 U/L). Additionally, TSH level was significantly higher in exposed farmers (median =1.39µIU/ml) compared to controls (median = 0.91 µIU/ml) (p=0.032). While, the exposed group had a lower T4 level (6.91 1.91 µg/dl) compared to the control group (7.79 2.10µg/dl), with the statistically significant difference between the two groups (p = 0.045). The exposed group had significantly lower level of testosterone hormone (median=3.37 ng/ml) compared to the control group (median= 6.22 ng/ml) (p=0.003). While, the exposed farmers had statistically insignificant higher level of fasting blood glucose (median =89 mg/dl) than the controls (median=88 mg/dl). Furthermore, farmers who did not use PPE had statistically significant lower level of T4 (6.57 1.81µg/dl) than farmers who used PPE during handling of pesticides (8.01 1.89 µg/dl). Conclusion: Chronic exposure to pesticides exerts disturbing action on reproductive function and thyroid function of the male farmers.Keywords: chronic occupational pesticide exposure, Diabetes mellitus, male reproductive hormones, thyroid function
Procedia PDF Downloads 1361159 Evaluation of Serine and Branched Chain Amino Acid Levels in Depression and the Beneficial Effects of Exercise in Rats
Authors: V. A. Doss, R. Sowndarya, K. Juila Rose Mary
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Objective: Amino acid neurotransmitter system dysfunction plays a major role in the pathophysiology of depression. The objective of the present study was to identify the amino acids as possible metabolite biomarkers for depression using GCMS (Gas Chromatography Mass Spectrometry) before and after exercise regimen in brain samples of depression induced animal models. Methods: Depression-like behaviour was induced by Chronic Unpredictable mild stress (CUMS). Severity of depression was measured by forced swim test (FST) and sucrose consumption test (SCT). Swimming protocol was followed for 4 weeks of exercise treatment. Brain obtained from depressed and exercise treated rats were used for the metabolite analysis by GCMS. Subsequent statistical analysis obtained by ANOVA followed by post hoc test revealed significant metabolic changes. Results: Amino acids such as alanine, glycine, serine, glutamate, homocysteine, proline and branched chain aminoacids (BCAs) Leucine, Isoleucine, Valine were determined in brain samples of control, depressed and exercised groups. Among these amino acids, the levels of D-Serine and branched chain amino acids were found to be decreased in depression induced rats. After four weeks of swimming exercise regimen, there were improvements in the levels of serine and Branched chain amino acids. Conclusion: We suggest that Serine and BCAs may be investigated as potential metabolite markers using GCMS and their beneficial metabolic changes in Exercise.Keywords: metabolomics, depression, forced swim test, exercise, amino acid metabolites, GCMS, biomarker
Procedia PDF Downloads 3261158 Economic and Financial Crime, Forensic Accounting and Sustainable Developments Goals (SDGs). Bibliometric Analysis
Authors: Monica Violeta Achim, Sorin Nicolae Borlea
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This aim of this work is to stress the needs for enhancing the role of forensic accounting in fighting economic and financial crime, in the context of the new international regulation movements in this area enhanced by the International Federation of Accountants (IFAC). Corruption, money laundering, tax evasion and other frauds significant hamper the economic growth and human development and, ultimately, the UN Sustainable Development Goals. The present paper also stresses the role of good governance in fighting the frauds, in order to achieve the most suitable sustainable development of the society. In this view, we made a bibliometric systematic review on forensic accounting and its contribution towards fraud detection and prevention and theirs relationship with good governance and Sustainable Developments Goals (SDGs). In this view, two powerful bibliometric visual software tools, VosViewer and CiteSpace are used in order to analyze published papers identifies in Scopus and Web of Science databases over the time. Our findings reveal the main red flags identified in literature as used tools by forensic accounting, the evolution in time of the interest of the topic, the distribution in space among world countries and connectivity with patterns of a good governance. Visual designs and scientific maps are useful to show these findings, in a visual way. Our findings are useful for managers and policy makers to provide important avenues that may help in reaching the 2030 Agenda for Sustainable Development, adopted by all United Nations Member States in 2015, in the area of using forensic accounting in preventing frauds.Keywords: forensic accounting, frauds, red flags, SDGs
Procedia PDF Downloads 1401157 Experimental Investigation of the Thermal Conductivity of Neodymium and Samarium Melts by a Laser Flash Technique
Authors: Igor V. Savchenko, Dmitrii A. Samoshkin
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The active study of the properties of lanthanides has begun in the late 50s of the last century, when methods for their purification were developed and metals with a relatively low content of impurities were obtained. Nevertheless, up to date, many properties of the rare earth metals (REM) have not been experimentally investigated, or insufficiently studied. Currently, the thermal conductivity and thermal diffusivity of lanthanides have been studied most thoroughly in the low-temperature region and at moderate temperatures (near 293 K). In the high-temperature region, corresponding to the solid phase, data on the thermophysical characteristics of the REM are fragmentary and in some cases contradictory. Analysis of the literature showed that the data on the thermal conductivity and thermal diffusivity of light REM in the liquid state are few in number, little informative (only one point corresponds to the liquid state region), contradictory (the nature of the thermal conductivity change with temperature is not reproduced), as well as the results of measurements diverge significantly beyond the limits of the total errors. Thereby our experimental results allow to fill this gap and to clarify the existing information on the heat transfer coefficients of neodymium and samarium in a wide temperature range from the melting point up to 1770 K. The measurement of the thermal conductivity of investigated metallic melts was carried out by laser flash technique on an automated experimental setup LFA-427. Neodymium sample of brand NM-1 (99.21 wt % purity) and samarium sample of brand SmM-1 (99.94 wt % purity) were cut from metal ingots and then ones were annealed in a vacuum (1 mPa) at a temperature of 1400 K for 3 hours. Measuring cells of a special design from tantalum were used for experiments. Sealing of the cell with a sample inside it was carried out by argon-arc welding in the protective atmosphere of the glovebox. The glovebox was filled with argon with purity of 99.998 vol. %; argon was additionally cleaned up by continuous running through sponge titanium heated to 900–1000 K. The general systematic error in determining the thermal conductivity of investigated metallic melts was 2–5%. The approximation dependences and the reference tables of the thermal conductivity and thermal diffusivity coefficients were developed. New reliable experimental data on the transport properties of the REM and their changes in phase transitions can serve as a scientific basis for optimizing the industrial processes of production and use of these materials, as well as ones are of interest for the theory of thermophysical properties of substances, physics of metals, liquids and phase transformations.Keywords: high temperatures, laser flash technique, liquid state, metallic melt, rare earth metals, thermal conductivity, thermal diffusivity
Procedia PDF Downloads 1981156 Numerical Simulation of Footing on Reinforced Loose Sand
Authors: M. L. Burnwal, P. Raychowdhury
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Earthquake leads to adverse effects on buildings resting on soft soils. Mitigating the response of shallow foundations on soft soil with different methods reduces settlement and provides foundation stability. Few methods such as the rocking foundation (used in Performance-based design), deep foundation, prefabricated drain, grouting, and Vibro-compaction are used to control the pore pressure and enhance the strength of the loose soils. One of the problems with these methods is that the settlement is uncontrollable, leading to differential settlement of the footings, further leading to the collapse of buildings. The present study investigates the utility of geosynthetics as a potential improvement of the subsoil to reduce the earthquake-induced settlement of structures. A steel moment-resisting frame building resting on loose liquefiable dry soil, subjected to Uttarkashi 1991 and Chamba 1995 earthquakes, is used for the soil-structure interaction (SSI) analysis. The continuum model can simultaneously simulate structure, soil, interfaces, and geogrids in the OpenSees framework. Soil is modeled with PressureDependentMultiYield (PDMY) material models with Quad element that provides stress-strain at gauss points and is calibrated to predict the behavior of Ganga sand. The model analyzed with a tied degree of freedom contact reveals that the system responses align with the shake table experimental results. An attempt is made to study the responses of footing structure and geosynthetics with unreinforced and reinforced bases with varying parameters. The result shows that geogrid reinforces shallow foundation effectively reduces the settlement by 60%.Keywords: settlement, shallow foundation, SSI, continuum FEM
Procedia PDF Downloads 1941155 Investigation on Remote Sense Surface Latent Heat Temperature Associated with Pre-Seismic Activities in Indian Region
Authors: Vijay S. Katta, Vinod Kushwah, Rudraksh Tiwari, Mulayam Singh Gaur, Priti Dimri, Ashok Kumar Sharma
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The formation process of seismic activities because of abrupt slip on faults, tectonic plate moments due to accumulated stress in the Earth’s crust. The prediction of seismic activity is a very challenging task. We have studied the changes in surface latent heat temperatures which are observed prior to significant earthquakes have been investigated and could be considered for short term earthquake prediction. We analyzed the surface latent heat temperature (SLHT) variation for inland earthquakes occurred in Chamba, Himachal Pradesh (32.5 N, 76.1E, M-4.5, depth-5km) nearby the main boundary fault region, the data of SLHT have been taken from National Center for Environmental Prediction (NCEP). In this analysis, we have calculated daily variations with surface latent heat temperature (0C) in the range area 1⁰x1⁰ (~120/KM²) with the pixel covering epicenter of earthquake at the center for a three months period prior to and after the seismic activities. The mean value during that period has been considered in order to take account of the seasonal effect. The monthly mean has been subtracted from daily value to study anomalous behavior (∆SLHT) of SLHT during the earthquakes. The results found that the SLHTs adjacent the epicenters all are anomalous high value 3-5 days before the seismic activities. The abundant surface water and groundwater in the epicenter and its adjacent region can provide the necessary condition for the change of SLHT. To further confirm the reliability of SLHT anomaly, it is necessary to explore its physical mechanism in depth by more earthquakes cases.Keywords: surface latent heat temperature, satellite data, earthquake, magnetic storm
Procedia PDF Downloads 1341154 CFD Analysis of the Blood Flow in Left Coronary Bifurcation with Variable Angulation
Authors: Midiya Khademi, Ali Nikoo, Shabnam Rahimnezhad Baghche Jooghi
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Cardiovascular diseases (CVDs) are the main cause of death globally. Most CVDs can be prevented by avoiding habitual risk factors. Separate from the habitual risk factors, there are some inherent factors in each individual that can increase the risk potential of CVDs. Vessel shapes and geometry are influential factors, having great impact on the blood flow and the hemodynamic behavior of the vessels. In the present study, the influence of bifurcation angle on blood flow characteristics is studied. In order to approach this topic, by simplifying the details of the bifurcation, three models with angles 30°, 45°, and 60° were created, then by using CFD analysis, the response of these models for stable flow and pulsatile flow was studied. In the conducted simulation in order to eliminate the influence of other geometrical factors, only the angle of the bifurcation was changed and other parameters remained constant during the research. Simulations are conducted under dynamic and stable condition. In the stable flow simulation, a steady velocity of 0.17 m/s at the inlet plug was maintained and in dynamic simulations, a typical LAD flow waveform is implemented. The results show that the bifurcation angle has an influence on the maximum speed of the flow. In the stable flow condition, increasing the angle lead to decrease the maximum flow velocity. In the dynamic flow simulations, increasing the bifurcation angle lead to an increase in the maximum velocity. Since blood flow has pulsatile characteristics, using a uniform velocity during the simulations can lead to a discrepancy between the actual results and the calculated results.Keywords: coronary artery, cardiovascular disease, bifurcation, atherosclerosis, CFD, artery wall shear stress
Procedia PDF Downloads 1641153 School Refusal Behaviours: The Roles of Adolescent and Parental Factors
Authors: Junwen Chen, Celina Feleppa, Tingyue Sun, Satoko Sasagawa, Michael Smithson
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School refusal behaviours refer to behaviours to avoid school attendance, chronic lateness in arriving at school, or regular early dismissal. Poor attendance in schools is highly correlated with anxiety, depression, suicide attempts, delinquency, violence, and substance use and abuse. Poor attendance is also a strong indicator of lower achievement in school, as well as problematic social-emotional development. Long-term consequences of school refusal behaviours include fewer opportunities for higher education, employment, and social difficulties, and high risks of later psychiatric illness. Given its negative impacts on youth educational outcomes and well-being, a thorough understanding of factors that are involved in the development of this phenomenon is warranted for developing effective management approaches. This study investigated parental and adolescent factors that may contribute to school refusal behaviours by specifically focusing on the role of parental and adolescents’ anxiety and depression, emotion dysregulation, and parental rearing style. Findings are expected to inform the identification of both parental and adolescents’ factors that may contribute to school refusal behaviours. This knowledge will enable novel and effective approaches that incorporate these factors to managing school refusal behaviours in adolescents, which in turn improve their school and daily functioning. Results are important for an integrative understanding of school refusal behaviours. Furthermore, findings will also provide information for policymakers to weigh the benefits of interventions targeting school refusal behaviours in adolescents. One-hundred-and-six adolescents aged 12-18 years (mean age = 14.79 years old, SD = 1.78, males = 44) and their parents (mean age = 47.49 years old, SD = 5.61, males = 27) completed an online questionnaire measuring both parental and adolescents’ anxiety, depression, emotion dysregulation, parental rearing styles, and adolescents’ school refusal behaviours. Adolescents with school refusal behaviours reported greater anxiety and depression, with their parents showing greater emotion dysregulation. Parental emotion dysregulation and adolescents’ anxiety and depression predicted school refusal behaviours independently. To date, only limited studies have investigated the interplay between parental and youth factors in relation to youth school refusal behaviours. Although parental emotion dysregulation has been investigated in relation to youth emotion dysregulation, little is known about its role in the context of school refusal. This study is one of the very few that investigated both parental and adolescent factors in relation to school refusal behaviours in adolescents. The findings support the theoretical models that emphasise the role of youth and parental psychopathology in school refusal behaviours. Future management of school refusal behaviours should target adolescents’ anxiety and depression while incorporating training for parental emotion regulation skills.Keywords: adolescents, school refusal behaviors, parental factors, anxiety and depression, emotion dysregulation
Procedia PDF Downloads 1271152 Microstructure, Mechanical, Electrical and Thermal Properties of the Al-Si-Ni Ternary Alloy
Authors: Aynur Aker, Hasan Kaya
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In recent years, the use of the aluminum based alloys in the industry and technology are increasing. Alloying elements in aluminum have further been improving the strength and stiffness properties that provide superior compared to other metals. In this study, investigation of physical properties (microstructure, microhardness, tensile strength, electrical conductivity and thermal properties) in the Al-12.6wt.%Si-%2wt.Ni ternary alloy were investigated. Al-Si-Ni alloy was prepared in a graphite crucible under vacuum atmosphere. The samples were directionally solidified upwards with different growth rate (V) at constant temperature gradient G (7.73 K/mm). The microstructures (flake spacings, λ), microhardness (HV), ultimate tensile strength, electrical resistivity and thermal properties enthalpy of fusion and specific heat and melting temperature) of the samples were measured. Influence of the growth rate and flake spacings on microhardness, ultimate tensile strength and electrical resistivity were investigated and relationships between them were experimentally obtained by using regression analysis. According to results, λ values decrease with increasing V, but microhardness, ultimate tensile strength, electrical resistivity values increase with increasing V. Variations of electrical resistivity for cast samples with the temperature in the range of 300-1200 K were also measured by using a standard dc four-point probe technique. The enthalpy of fusion and specific heat for the same alloy was also determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from liquid to solid. The results obtained in this work were compared with the previous similar experimental results obtained for binary and ternary alloys.Keywords: electrical resistivity, enthalpy, microhardness, solidification, tensile stress
Procedia PDF Downloads 3761151 The Perception and Integration of Lexical Tone and Vowel in Mandarin-speaking Children with Autism: An Event-Related Potential Study
Authors: Rui Wang, Luodi Yu, Dan Huang, Hsuan-Chih Chen, Yang Zhang, Suiping Wang
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Enhanced discrimination of pure tones but diminished discrimination of speech pitch (i.e., lexical tone) were found in children with autism who speak a tonal language (Mandarin), suggesting a speech-specific impairment of pitch perception in these children. However, in tonal languages, both lexical tone and vowel are phonemic cues and integrally dependent on each other. Therefore, it is unclear whether the presence of phonemic vowel dimension contributes to the observed lexical tone deficits in Mandarin-speaking children with autism. The current study employed a multi-feature oddball paradigm to examine how vowel and tone dimensions contribute to the neural responses for syllable change detection and involuntary attentional orienting in school-age Mandarin-speaking children with autism. In the oddball sequence, syllable /da1/ served as the standard stimulus. There were three deviant stimulus conditions, representing tone-only change (TO, /da4/), vowel-only change (VO, /du1/), and change of tone and vowel simultaneously (TV, /du4/). EEG data were collected from 25 children with autism and 20 age-matched normal controls during passive listening to the stimulation. For each deviant condition, difference waveform measuring mismatch negativity (MMN) was derived from subtracting the ERP waveform to the standard sound from that to the deviant sound for each participant. Additionally, the linear summation of TO and VO difference waveforms was compared to the TV difference waveform, to examine whether neural sensitivity for TV change detection reflects simple summation or nonlinear integration of the two individual dimensions. The MMN results showed that the autism group had smaller amplitude compared with the control group in the TO and VO conditions, suggesting impaired discriminative sensitivity for both dimensions. In the control group, amplitude of the TV difference waveform approximated the linear summation of the TO and VO waveforms only in the early time window but not in the late window, suggesting a time course from dimensional summation to nonlinear integration. In the autism group, however, the nonlinear TV integration was already present in the early window. These findings suggest that speech perception atypicality in children with autism rests not only in the processing of single phonemic dimensions, but also in the dimensional integration process.Keywords: autism, event-related potentials , mismatch negativity, speech perception
Procedia PDF Downloads 2191150 Sulforaphane Attenuates Muscle Inflammation in Dystrophin-Deficient Mdx Mice via Nrf2/HO-1 Signaling Pathway
Authors: Chengcao Sun, Cuili Yang, Shujun Li, Ruilin Xue, Yongyong Xi, Liang Wang, Dejia Li
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Backgrounds: Inflammation is widely distributed in patients with Duchenne muscular dystrophy (DMD), and ultimately leads to progressive deterioration of muscle function with the co-effects of chronic muscle damage, oxidative stress, and reduced oxidative capacity. NF-E2-related factor 2 (Nrf2) plays a critical role in defending against inflammation in different tissues via activation of phase II enzymes, heme oxygenase-1 (HO-1). However, whether Nrf2/HO-1 pathway can attenuate muscle inflammation on DMD remains unknown. The purpose of this study was to determine the anti-inflammatory effects of Sulforaphane (SFN) on DMD. Methods: 4-week-old male mdx mice were treated with SFN by gavage (2 mg/kg body weight per day) for 4 weeks. Gastrocnemius, tibial anterior and triceps brachii muscles were collected for related analysis. Immune cell infiltration in skeletal muscles was analyzed by H&E staining and immuno-histochemistry. Moreover, the expressions of inflammatory cytokines,pro-inflammatory cytokines and Nrf2/HO-1 pathway were detected by western blot, qRT-PCR, immunohistochemistry and immunofluorescence assays. Results: Our results demonstrated that SFN treatment increased the expression of muscle phase II enzymes HO-1 in Nrf2 dependent manner. Inflammation in mdx skeletal muscles was reduced by SFN treatment as indicated by decreased immune cell infiltration and lower expressions of the inflammatory cytokines CD45, pro-inflammatory cytokines tumour necrosis factor-α and interleukin-6 in the skeletal muscles of mdx mice. Conclusions: Collectively, these results show that SFN can ameliorate muscle inflammation in mdx mice by Nrf2/HO-1 pathway, which indicates Nrf2/HO-1 pathway may represent a new therapeutic target for DMD.Keywords: sulforaphane, Nrf2, HO-1, inflammation
Procedia PDF Downloads 3341149 A Qualitative Study of the Effect of Sibling and Parental Relationships on Coping Mechanisms in Families of Children with Autism Spectrum Disorder
Authors: Smriti Gour, Neelam Pandey
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The objective of this study was to describe and analyse the mutual relationship between the coping mechanisms used by the families of a child with Autism Spectrum Disorder (ASD) and family dynamics and the effect sibling interactions have on the dynamics and coping mechanisms in an urban setup. In-depth interviews were conducted for 25 families, with 4 members each in the Delhi NCR area in India. The families who were interviewed had a younger child who had received a diagnosis of ASD between the ages of 5-12. The in-depth questionnaires contained open-ended questions and the interviews were conducted separately for the mother, father and the typically developing sibling. The key findings of the study suggested that lack of communication was a common factor in most families (n=19) leading to other difficulties like stress and relationship dysfunction. It also fostered a fallacious perception of the relationship dynamics in the family in most of the interviewed families and changed depending on the family member being interviewed. In families where the typically developing elder sibling had a good relationship with the autistic child, the family dynamics were found to be more stable, and the overall family well-being was better maintained. The coping mechanisms employed by the families were also more positive and tended to work better if the typically developing sibling maintained a positive and interactive relationship with the parents and the autistic child. The type of coping mechanisms had a major impact on the relationship between the parents and in dictating the dynamics of the family of the child with ASD. Spirituality, professional help, family support and household help emerged to be the most effective coping mechanisms for the families, with spirituality emerging to be the most positive and effective coping mechanism in the families interviewed.Keywords: autism spectrum disorder, coping mechanism, family dynamics, parental relationships, siblings
Procedia PDF Downloads 3181148 Rule-Of-Mixtures: Predicting the Bending Modulus of Unidirectional Fiber Reinforced Dental Composites
Authors: Niloofar Bahramian, Mohammad Atai, Mohammad Reza Naimi-Jamal
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Rule of mixtures is the simple analytical model is used to predict various properties of composites before design. The aim of this study was to demonstrate the benefits and limitations of the Rule-of-Mixtures (ROM) for predicting bending modulus of a continuous and unidirectional fiber reinforced composites using in dental applications. The Composites were fabricated from light curing resin (with and without silica nanoparticles) and modified and non-modified fibers. Composite samples were divided into eight groups with ten specimens for each group. The bending modulus (flexural modulus) of samples was determined from the slope of the initial linear region of stress-strain curve on 2mm×2mm×25mm specimens with different designs: fibers corona treatment time (0s, 5s, 7s), fibers silane treatment (0%wt, 2%wt), fibers volume fraction (41%, 33%, 25%) and nanoparticles incorporation in resin (0%wt, 10%wt, 15%wt). To study the fiber and matrix interface after fracture, single edge notch beam (SENB) method and scanning electron microscope (SEM) were used. SEM also was used to show the nanoparticles dispersion in resin. Experimental results of bending modulus for composites made of both physical (corona) and chemical (silane) treated fibers were in reasonable agreement with linear ROM estimates, but untreated fibers or non-optimized treated fibers and poor nanoparticles dispersion did not correlate as well with ROM results. This study shows that the ROM is useful to predict the mechanical behavior of unidirectional dental composites but fiber-resin interface and quality of nanoparticles dispersion play important role in ROM accurate predictions.Keywords: bending modulus, fiber reinforced composite, fiber treatment, rule-of-mixtures
Procedia PDF Downloads 2741147 A Hybrid Energy Storage Module for the Emergency Energy System of the Community Shelter in Yucatán, México
Authors: María Reveles-Miranda, Daniella Pacheco-Catalán
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Sierra Papacal commissary is located north of Merida, Yucatan, México, where the indigenous Maya population predominates. Due to its location, the region has an elevation of fewer than 4.5 meters above sea level, with a high risk of flooding associated with storms and hurricanes and a high vulnerability of infrastructure and housing in the presence of strong gusts of wind. In environmental contingencies, the challenge is providing an autonomous electrical supply using renewable energy sources that cover vulnerable populations' health, food, and water pumping needs. To address this challenge, a hybrid energy storage module is proposed for the emergency photovoltaic (PV) system of the community shelter in Sierra Papacal, Yucatán, which combines high-energy-density batteries and high-power-density supercapacitors (SC) in a single module, providing a quick response to energy demand, reducing the thermal stress on batteries and extending their useful life. Incorporating SC in energy storage modules can provide fast response times to power variations and balanced energy extraction, ensuring a more extended period of electrical supply to vulnerable populations during contingencies. The implemented control strategy increases the module's overall performance by ensuring the optimal use of devices and balanced energy exploitation. The operation of the module with the control algorithm is validated with MATLAB/Simulink® and experimental tests.Keywords: batteries, community shelter, environmental contingencies, hybrid energy storage, isolated photovoltaic system, supercapacitors
Procedia PDF Downloads 911146 Application of Continuum Damage Concept to Simulation of the Interaction between Hydraulic Fractures and Natural Fractures
Authors: Anny Zambrano, German Gonzalez, Yair Quintero
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The continuum damage concept is used to study the interaction between hydraulic fractures and natural fractures, the objective is representing the path and relation among this two fractures types and predict its complex behavior without the need to pre-define their direction as occurs in other finite element applications, providing results more consistent with the physical behavior of the phenomenon. The approach uses finite element simulations through Abaqus software to model damage fracturing, the fracturing process by damage propagation in a rock. The modeling the phenomenon develops in two dimensional (2D) so that the fracture will be represented by a line and the crack front by a point. It considers nonlinear constitutive behavior, finite strain, time-dependent deformation, complex boundary conditions, strain hardening and softening, and strain based damage evolution in compression and tension. The complete governing equations are provided and the method is described in detail to permit readers to replicate all results. The model is compared to models that are published and available. Comparisons are focused in five interactions between natural fractures (NF) and hydraulic fractures: Fractured arrested at NF, crossing NF with or without offset, branching at intersecting NFs, branching at end of NF and NF dilation due to shear slippage. The most significant new finding is, that is not necessary to use pre-defined addresses propagation and stress condition can be evaluated as a dominant factor in the process. This is important because it can model in a more real way the generated complex hydraulic fractures, and be a valuable tool to predict potential problems and different geometries of the fracture network in the process of fracturing due to fluid injection.Keywords: continuum damage, hydraulic fractures, natural fractures, complex fracture network, stiffness
Procedia PDF Downloads 3431145 Differentiation of Drug Stereoisomers by Their Stereostructure-Selective Membrane Interactions as One of Pharmacological Mechanisms
Authors: Maki Mizogami, Hironori Tsuchiya, Yoshiroh Hayabuchi, Kenji Shigemi
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Since drugs exhibit significant structure-dependent differences in activity and toxicity, their differentiation based on the mechanism of action should have implications for comparative drug efficacy and safety. We aimed to differentiate drug stereoisomers by their stereostructure-selective membrane interactions underlying pharmacological and toxicological effects. Biomimetic lipid bilayer membranes were prepared with phospholipids and sterols (either cholesterol or epicholesterol) to mimic the lipid compositions of neuronal and cardiomyocyte membranes and to provide these membranes with the chirality. The membrane preparations were treated with different classes of stereoisomers at clinically- and pharmacologically-relevant concentrations (25-200 μM), followed by measuring fluorescence polarization to determine the membrane interactivity of drugs to change the physicochemical property of membranes. All the tested drugs acted on lipid bilayers to increase or decrease the membrane fluidity. Drug stereoisomers could not be differentiated when interacting with the membranes consisting of phospholipids alone. However, they stereostructure-selectively interacted with neuro-mimetic and cardio-mimetic membranes containing 40 mol% cholesterol ((3β)-cholest-5-en-3-ol) to show the relative potencies being local anesthetic R(+)-bupivacaine > rac-bupivacaine > S(‒)-bupivacaine, α2-adrenergic agonistic D-medetomidine > rac-medetomidine > L-medetomidine, β-adrenergic antagonistic R(+)-propranolol > rac-propranolol > S(–)-propranolol, NMDA receptor antagonistic S(+)-ketamine > rac-ketamine, analgesic monoterpenoid (+)-menthol > (‒)-menthol, non-steroidal anti-inflammatory S(+)-ibuprofen > rac-ibuprofen > R(‒)-ibuprofen, and bioactive flavonoid (+)-epicatechin > (‒)-epicatechin. All of the order of membrane interactivity were correlated to those of beneficial and adverse effects of the tested stereoisomers. In contrast, the membranes prepared with epicholesterol ((3α)-chotest-5-en-3-ol), an epimeric form of cholesterol, reversed the rank order of membrane interactivity to be S(‒)-enantiomeric > racemic > R(+)-enantiomeric bupivacaine, L-enantiomeric > racemic > D-enantiomeric medetomidine, S(–)-enantiomeric > racemic > R(+)-enantiomeric propranolol, racemic > S(+)-enantiomeric ketamine, (‒)-enantiomeric > (+)-enantiomeric menthol, R(‒)-enantiomeric > racemic > S(+)-enantiomeric ibuprofen, and (‒)-enantiomeric > (+)-enantiomeric epicatechin. The opposite configuration allows drug molecules to interact with chiral sterol membranes enantiomer-selectively. From the comparative results, it is speculated that a 3β-hydroxyl group in cholesterol is responsible for the enantioselective interactions of drugs. In conclusion, the differentiation of drug stereoisomers by their stereostructure-selective membrane interactions would be useful for designing and predicting drugs with higher activity and/or lower toxicity.Keywords: chiral membrane, differentiation, drug stereoisomer, enantioselective membrane interaction
Procedia PDF Downloads 2231144 Fatigue Behavior of Friction Stir Welded EN AW 5754 Aluminum Alloy Using Load Increase Procedure
Authors: A. B. Chehreh, M. Grätzel, M. Klein, J. P. Bergmann, F. Walther
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Friction stir welding (FSW) is an advantageous method in the thermal joining processes, featuring the welding of various dissimilar and similar material combinations, joining temperatures below the melting point which prevents irregularities such as pores and hot cracks as well as high strengths mechanical joints near the base material. The FSW process consists of a rotating tool which is made of a shoulder and a probe. The welding process is based on a rotating tool which plunges in the workpiece under axial pressure. As a result, the material is plasticized by frictional heat which leads to a decrease in the flow stress. During the welding procedure, the material is continuously displaced by the tool, creating a firmly bonded weld seam behind the tool. However, the mechanical properties of the weld seam are affected by the design and geometry of the tool. These include in particular microstructural and surface properties which can favor crack initiation. Following investigation compares the dynamic properties of FSW weld seams with conventional and stationary shoulder geometry based on load increase test (LIT). Compared to classical Woehler tests, it is possible to determine the fatigue strength of the specimens after a short amount of time. The investigations were carried out on a robotized welding setup on 2 mm thick EN AW 5754 aluminum alloy sheets. It was shown that an increased tensile and fatigue strength can be achieved by using the stationary shoulder concept. Furthermore, it could be demonstrated that the LIT is a valid method to describe the fatigue behavior of FSW weld seams.Keywords: aluminum alloy, fatigue performance, fracture, friction stir welding
Procedia PDF Downloads 1531143 Microalbuminuria in Patients with Hypertension Visiting Tertiary Care Centre, Western Nepal
Authors: Binaya Tamang, Buddhi R. Pokharel, Narayan Gautam, Puspa R. Dhakal, Yuresh Twayana
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Background and Objective: Microalbuminuria is often regarded as a sign of end-organ damage due to hypertension, with an increased risk for renal diseases. The present study was designed to find the prevalence of microalbuminuria in hypertensive patients by determining albumin creatinine ratio (ACR) and the association of ACR and microalbuminuria status with different stages and duration of hypertension (HTN). Also, to establish the correlation of systolic and diastolic blood pressure (SBP and DBP) with various parameters viz; ACR, urinary microalbumin (UMA), estimated glomerular filtration rate (eGFR), urinary creatinine (Ucreat), serum creatinine (Screat), and find out their significance among HTN and ACR status. Materials and Methods: A hospital-based cross-sectional study was conducted in the Department of Biochemistry in collaboration with the Department of Internal Medicine, UCMS, Bhairahawa, Nepal from April 2019 to September 2019 after obtaining ethical approval from institutional review committee (IRC), UCMS. A total of 120 hypertensive patients were enrolled whose blood, and spot urine samples were taken. eGFR was calculated by using Cockcroft-Gault formula after determining Screat while ACR was calculated after measuring Ucreat and UMA from the spot urine sample. Creatinine was estimated from modified jaffes’ reaction, whereas urinary micro albumin was done by Mispa i3 analyzer. Data were analyzed by using SPSS. 20 using p-value ≤ 0.05 as statistically significant. Results: In our study, the highest enrolled were grade II HTN (36.7%) followed by normal (33.3%), grade I (20.8%) and grade III (9.2%). Evaluating the ACR status, 19.2% were microalbuminuria, and the rest were normal. Though the ACR status (normal and microalbuminuria) was not statistically significant with HTN status (P=0.860) and the duration of HTN status (P=0.165), 5 (45.5%) out of 11 grade III HTN were microalbuminuria and the prevalence was also higher for longer duration .i.e., more than 10 years. In microalbuminuria, both the SBP (p=0.023, r=0.471) and DBP (P=0.034, r= 0.444) were strongly and positively correlated with Screat, in contrast to eGFR, which was negatively but weakly correlated. With the significant difference between the HTN group, the mean ACR (P=0.047) and UMA (P=0.02) were found to be highest among grade III patients, i.e., 84.3 ± 113.3 mg/gm. and 88.4 ± 83.9 mg/l respectively. The mean eGFR (64.2 ± 24.8 vs 77.2 ± 18.1 ml/min) was considerably lower in microalbuminuria ( p=0.026) than the normal in contrast to the SBP (160 ± 33.7 vs. 146.6 ± 19.5 mm of Hg) which was significantly higher (P=0.008). Among the different BMI category, the mean ACR was found to be significantly different (P= 0.01) with the highest value in underweight (115.2 ± 51.5 mg/gm.) and lowest in overweight (31.8 ± 4.3 mg/gm.). Conclusion: The study recommends that the microalbuminuria can be a very useful and imperative predictor of deranged kidney functions in hypertensive patients. The high value of ACR and UMA in hypertensive patients along with significant increased Screat, SBP whereas decreased eGFR in microalbuminuria patients explicitly supports the above statement.Keywords: albumin creatinine ratio, hypertension, microalbuminuria, renal disease
Procedia PDF Downloads 1361142 Effects of Potential Chloride-Free Admixtures on Selected Mechanical Properties of Kenya Clay-Based Cement Mortars
Authors: Joseph Mwiti Marangu, Joseph Karanja Thiong'o, Jackson Muthengia Wachira
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The mechanical performance of hydrated cements mortars mainly depends on its compressive strength and setting time. These properties are crucial in the construction industry. Pozzolana based cements are mostly characterized by low 28 day compressive strength and long setting times. These are some of the major impediments to their production and diverse uses despite numerous technological and environmental benefits associated with them. The study investigated the effects of potential chemical activators on calcined clay- Portland cement blends with an aim to achieve high early compressive strength and shorter setting times in cement mortar. In addition, standard consistency, soundness and insoluble residue of all cement categories was determined. The test cement was made by blending calcined clays with Ordinary Portland Cement (OPC) at replacement levels from 35 to 50 percent by mass of the OPC to make test cement labeled PCC for the purposes of this study. Mortar prisms measuring 40mmx40mmx160mm were prepared and cured in accordance with KS EAS 148-3:2000 standard. Solutions of Na2SO4, NaOH, Na2SiO3 and Na2CO3 containing 0.5- 2.5M were separately added during casting. Compressive strength was determined at 2rd, 7th, 28th and 90th day of curing. For comparison purposes, commercial Portland Pozzolana cement (PPC) and Ordinary Portland Cement (OPC) were also investigated without activators under similar conditions. X-Ray Florescence (XRF) was used for chemical analysis while X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were used for mineralogical analysis of the test samples. The results indicated that addition of activators significantly increased the 2nd and 7th day compressive strength but minimal increase on the 28th and 90th day compressive strength. A relatively linear relationship was observed between compressive strength and concentration of activator solutions up to 28th of curing. Addition of the said activators significantly reduced both initial and final setting time. Standard consistency and soundness varied with increased amount of clay in the test cement and concentration of activators. Amount of insoluble residues increased with increased replacement of OPC with calcined clays. Mineralogical studies showed that N-A-S-H is formed in addition to C-S-H. In conclusion, the concentration of 2 molar for all activator solutions produced the optimum compressive strength and greatly reduced the setting times for all cement mortars.Keywords: activators, admixture, cement, clay, pozzolana
Procedia PDF Downloads 2621141 Immersive Environment as an Occupant-Centric Tool for Architecture Criticism and Architectural Education
Authors: Golnoush Rostami, Farzam Kharvari
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In recent years, developments in the field of architectural education have resulted in a shift from conventional teaching methods to alternative state-of-the-art approaches in teaching methods and strategies. Criticism in architecture has been a key player both in the profession and education, but it has been mostly offered by renowned individuals. Hence, not only students or other professionals but also critics themselves may not have the option to experience buildings and rely on available 2D materials, such as images and plans, that may not result in a holistic understanding and evaluation of buildings. On the other hand, immersive environments provide students and professionals the opportunity to experience buildings virtually and reflect their evaluation by experiencing rather than judging based on 2D materials. Therefore, the aim of this study is to compare the effect of experiencing buildings in immersive environments and 2D drawings, including images and plans, on architecture criticism and architectural education. As a result, three buildings that have parametric brick facades were studied through 2D materials and in Unreal Engine v. 24 as an immersive environment among 22 architecture students that were selected using convenient sampling and were divided into two equal groups using simple random sampling. This study used mixed methods, including quantitative and qualitative methods; the quantitative section was carried out by a questionnaire, and deep interviews were used for the qualitative section. A questionnaire was developed for measuring three constructs, including privacy regulation based on Altman’s theory, the sufficiency of illuminance levels in the building, and the visual status of the view (visually appealing views based on obstructions that may have been caused by facades). Furthermore, participants had the opportunity to reflect their understanding and evaluation of the buildings in individual interviews. Accordingly, the collected data from the questionnaires were analyzed using independent t-test and descriptive analyses in IBM SPSS Statistics v. 26, and interviews were analyzed using the content analysis method. The results of the interviews showed that the participants who experienced the buildings in the immersive environment were able to have a thorough and more precise evaluation of the buildings in comparison to those who studied them through 2D materials. Moreover, the analyses of the respondents’ questionnaires revealed that there were statistically significant differences between measured constructs among the two groups. The outcome of this study suggests that integrating immersive environments into the profession and architectural education as an effective and efficient tool for architecture criticism is vital since these environments allow users to have a holistic evaluation of buildings for vigorous and sound criticism.Keywords: immersive environments, architecture criticism, architectural education, occupant-centric evaluation, pre-occupancy evaluation
Procedia PDF Downloads 1341140 Calpain-Mediated, Cisplain-Induced Apoptosis in Breast Cancer Cells
Authors: Shadia Al-Bahlani, Khadija Al-Bulushi, Zuweina Al-Hadidi, Buthaina Al-Dhahl, Nadia Al-Abri
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Breast cancer is the most common cancer in women worldwide. Triple-Negative Breast Cancer (TNBC) is an aggressive type of breast cancer, which is defined by the absence of Estrogen (ER), Progesterone (PR) and human epidermal growth factor (Her-2) receptors. The calpain system plays an important role in many cellular processes including apoptosis, necrosis, cell signaling and proliferation. However, the role of calpain in cisplatin (CDDP)-induced apoptosis in TNBC cells is not fully understood. Here, TNBC (MDA-MB231) cells were treated with different concentration of CDDP (0, 20 & 40 µM) and calpain activation and apoptosis were measured by western blot and Hoechst Stain respectively. In addition, calpain modulation by either activation and/or inhibition and its effect on CDDP-induced apoptosis were assessed by the same above approaches. Our findings showed that CDDP induced endoplasmic reticulum stress and thus Calcium release and subsequently activate calpain α-fodrin cleavage indicated by the increase in GRP78 and Calmodulin protein expression and respectively in MDA-MB231 cells. It also induced apoptosis as measured by Hoechst stain and caspase-12 cleavage. Calpain activation by both Cyclopiazonic acid and Thapsigargin showed similar effect and enhanced the sensitivity of these cells to CDDP treatment. On the other hand, calpain inhibition by either specific siRNA and/or exogenous inhibitor (Calpeptin) had an adverse effect where it attenuated calpain activation and thus CDDP- induced apoptosis in these cells. Altogether, these findings suggested that calpain activation play an essential role in sensitizing the TNBC cells to CDDP-induced apoptosis. This might lead to the discovery of novel treatment to over this aggressive type of breast cancer.Keywords: calpain, cisplatin, apoptosis, breast cancer
Procedia PDF Downloads 3451139 Environmental Monitoring by Using Unmanned Aerial Vehicle (UAV) Images and Spatial Data: A Case Study of Mineral Exploitation in Brazilian Federal District, Brazil
Authors: Maria De Albuquerque Bercot, Caio Gustavo Mesquita Angelo, Daniela Maria Moreira Siqueira, Augusto Assucena De Vasconcellos, Rodrigo Studart Correa
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Mining is an important socioeconomic activity in Brazil although it negatively impacts the environment. Mineral operations cause irreversible changes in topography, removal of vegetation and topsoil, habitat destruction, displacement of fauna, loss of biodiversity, soil erosion, siltation of watercourses and have potential to enhance climate change. Due to the impacts and its pollution potential, mining activity in Brazil is legally subjected to environmental licensing. Unlicensed mining operations or operations that not abide to the terms of an obtained license are taken as environmental crimes in the country. This work reports a case analyzed in the Forensic Institute of the Brazilian Federal District Civil Police. The case consisted of detecting illegal aspects of sand exploitation from a licensed mine in Federal District, nearby Brasilia city. The fieldwork covered an area of roughly 6 ha, which was surveyed with an unmanned aerial vehicle (UAV) (PHANTOM 3 ADVANCED). The overflight with UAV took about 20 min, with maximum flight height of 100 m. 592 UAV georeferenced images were obtained and processed in a photogrammetric software (AGISOFT PHOTOSCAN 1.1.4), which generated a mosaic of geo-referenced images and a 3D model in less than six working hours. The 3D model was analyzed in a forensic software for accurate modeling and volumetric analysis. (MAPTEK I-SITE FORENSIC 2.2). To ensure the 3D model was a true representation of the mine site, coordinates of ten control points and reference measures were taken during fieldwork and compared to respective spatial data in the model. Finally, these spatial data were used for measuring mining area, excavation depth and volume of exploited sand. Results showed that mine holder had not complied with some terms and conditions stated in the granted license, such as sand exploration beyond authorized extension, depth and volume. Easiness, the accuracy and expedition of procedures used in this case highlight the employment of UAV imagery and computational photogrammetry as efficient tools for outdoor forensic exams, especially on environmental issues.Keywords: computational photogrammetry, environmental monitoring, mining, UAV
Procedia PDF Downloads 3191138 Effect of Ease of Doing Business to Economic Growth among Selected Countries in Asia
Authors: Teodorica G. Ani
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Economic activity requires an encouraging regulatory environment and effective rules that are transparent and accessible to all. The World Bank has been publishing the annual Doing Business reports since 2004 to investigate the scope and manner of regulations that enhance business activity and those that constrain it. A streamlined business environment supporting the development of competitive small and medium enterprises (SMEs) may expand employment opportunities and improve the living conditions of low income households. Asia has emerged as one of the most attractive markets in the world. Economies in East Asia and the Pacific were among the most active in making it easier for local firms to do business. The study aimed to describe the ease of doing business and its effect to economic growth among selected economies in Asia for the year 2014. The study covered 29 economies in East Asia, Southeast Asia, South Asia and Middle Asia. Ease of doing business is measured by the Doing Business indicators (DBI) of the World Bank. The indicators cover ten aspects of the ease of doing business such as starting a business, dealing with construction permits, getting electricity, registering property, getting credit, protecting investors, paying taxes, trading across borders, enforcing contracts and resolving insolvency. In the study, Gross Domestic Product (GDP) was used as the proxy variable for economic growth. Descriptive research was the research design used. Graphical analysis was used to describe the income and doing business among selected economies. In addition, multiple regression was used to determine the effect of doing business to economic growth. The study presented the income among selected economies. The graph showed China has the highest income while Maldives produces the lowest and that observation were supported by gathered literatures. The study also presented the status of the ten indicators of doing business among selected economies. The graphs showed varying trends on how easy to start a business, deal with construction permits and to register property. Starting a business is easiest in Singapore followed by Hong Kong. The study found out that the variations in ease of doing business is explained by starting a business, dealing with construction permits and registering property. Moreover, an explanation of the regression result implies that a day increase in the average number of days it takes to complete a procedure will decrease the value of GDP in general. The research proposed inputs to policy which may increase the awareness of local government units of different economies on the simplification of the policies of the different components used in measuring doing business.Keywords: doing business, economic growth, gross domestic product, Asia
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