Search results for: principal stress direction

Authors: Jai Hyung Park, Eugene Kim, Jin Hun Park, Min Joon Oh

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Introduction: Subchondral insufficiency fracture of the femoral head (SIF) is a rare complication; however, it has been recognized to cause femoral head collapse. Subchondral insufficiency fracture (SIF) is caused by normal or physiological stress without any trauma. It has been reported in osteoporotic patients after the fixation of the proximal femur with an Intramedullary nail. Case presentation: We reported 5 cases with SIF of the femoral head after proximal femur fracture fixation with Intra-medullary nail. All patients had osteoporosis as an underlying disease. Good reduction was achieved in all 5 patients. SIF was found from about 3 months to 4 years after the initial operation, and all the fractures were solidly united at the final diagnosis. We investigated retrospectively the feature of those cases and several factors that affected the occurrence of SIF. Discussion: There are a few discussions regarding the SIF of the femoral head. These discussions may include the predisposing risk factors, how to diagnose the SIF in osteoporotic patients, and the peri-operative factors to prevent SIF. Conclusion: Subchondral insufficiency fracture of the femoral head is a considerable complication after the internal fixation of the proximal femur. There are several factors that can be modified. If they could be controlled in the peri-operative period, SIF could be prevented or handled in advance. Other options related to arthroplasty can be considered in old osteoporotic patients.

Keywords: insufficiency fracture of femoral head, intra-medullary nail, osteoporosis, proximal femur fracture

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Authors: Youn Young Shim, Ji Hye Kim, Jae Youl Cho, Martin J. T. Reaney

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Flaxseed (Linum usitatissimum L.) is gaining popularity in the food industry as a superfood due to its health-promoting properties. The flax plant synthesizes an array of biologically active cyclic peptides or linusorbs (LOs, a.k.a. cyclolinopeptides) from three or more ribosome-derived precursors. [1–9-NαC]-linusorb B3 and [1–9-NαC]-linusorb B2, suppress immunity, induce apoptosis in human epithelial cancer cell line (Calu-3) cells, and inhibit T-cell proliferation, but the mechanism of LOs action is unknown. Using gene expression analysis in nematode cultures and human cancer cell lines, we have observed that LOs exert their activity, in part, through induction of apoptosis. Specific LOs’ properties include: 1) distribution throughout the body after flaxseed consumption; 2) induce heat shock protein (HSP) 70A production as an indicator of stress and address the issue in Caenorhabditis elegans (exposure of nematode cultures to [1–9-NαC]-linusorb B3 induced a 30% increase in production of the HSP 70A protein); 3) induce apoptosis in Calu-3 cells; and 4) modulate regulatory genes in microarray analysis. These diverse activities indicate that LOs might induce apoptosis in cancer cells or act as versatile platforms to deliver a variety of biologically active molecules for cancer therapy.

Keywords: flaxseed, linusorb, cyclic peptide, orbitides, heat shock protein, apoptosis, anti-cancer

Procedia PDF Downloads 136

Authors: Ali A. Al-Jazaairry, Tahsin T. Sabbagh

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Presence of cavities in soil predictably induces ground deformation and changes in soil stress, which might influence adjacent existing pile foundations, though the effect of twin cavities on a nearby pile needs to be understood. This research is an attempt to identify the behaviour of piles subjected to axial load and embedded in cavitied clayey soil. A series of finite element modelling were conducted to investigate the performance of piled foundation located in such soils. The validity of the numerical simulation was evaluated by comparing it with available field test and alternative analytical model. The study involved many parameters such as twin cavities size, depth, spacing between cavities, and eccentricity of cavities from the pile axis on the pile performance subjected to axial load. The study involved many cases; in each case, a critical value has been found in which cavities’ presence has shown minimum impact on the behaviour of pile. Load-displacement relationships of the affecting parameters on the pile behaviour were presented to provide helpful information for designing piled foundation situated near twin underground cavities. It was concluded that the presence of the cavities within the soil mass reduces the ultimate capacity of pile. This reduction differs according to the size and location of the cavity.

Keywords: axial load, clay, finite element, pile, twin cavities, ultimate capacity

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Authors: S. Farid F. Mojtahedi, Ali Khosravi, Behnaz Naeimian, S. Adel A. Hosseini

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Land subsidence is a gradual settling or sudden sinking of the land surface from changes that take place underground. There are different causes of land subsidence; most notably, ground-water overdraft and severe weather conditions. Subsidence of the land surface due to ground water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers, which results in a loss of buoyancy of solid particles in the zone dewatered by the falling water table and accordingly compaction of the aquifer. On the other hand, exploitation of underground water may result in significant changes in degree of saturation of soil layers above the water table, increasing the effective stress in these layers, and considerable soil settlements. This study focuses on estimation of soil moisture at surface using different methods. Specifically, different methods for the estimation of moisture content at the soil surface, as an important term to solve Richard’s equation and estimate soil moisture profile are presented, and their results are discussed through comparison with field measurements obtained from Yanco1 station in south-eastern Australia. Surface soil moisture is not easy to measure at the spatial scale of a catchment. Due to the heterogeneity of soil type, land use, and topography, surface soil moisture may change considerably in space and time.

Keywords: artificial neural network, empirical method, remote sensing, surface soil moisture, unsaturated soil

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Authors: Suresh Salla

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In this paper, author explores for most sustainable last mile transport mode addressing present problems of traffic congestion, jams, pollution and travel stress. Development of energy-efficient sustainable integrated transport system(s) is/are must to make our cities more livable. Emphasis on autonomous, connected, electric, sharing system for effective utilization of systems (vehicles and public infrastructure) is on the rise. Many surface mobility innovations like PBS, Ride hailing, ride sharing, etc. are, although workable but if we analyze holistically, add to the already congested roads, difficult to ride in hostile weather, causes pollution and poses commuter stress. Sustainability of transportation is evaluated with respect to public adoption, average speed, energy consumption, and pollution. Why public prefer certain mode over others? How commute time plays a role in mode selection or shift? What are the factors play-ing role in energy consumption and pollution? Based on the study, it is clear that public prefer a transport mode which is exhaustive (i.e., less need for interchange – network is widespread) and intensive (i.e., less waiting time - vehicles are available at frequent intervals) and convenient with latest technologies. Average speed is dependent on stops, number of intersections, signals, clear route availability, etc. It is clear from Physics that higher the kerb weight of a vehicle; higher is the operational energy consumption. Higher kerb weight also demands heavier infrastructure. Pollution is dependent on source of energy, efficiency of vehicle, average speed. Mode can be made exhaustive when the unit infrastructure cost is less and can be offered intensively when the vehicle cost is less. Reliable and seamless integrated mobility till last ¼ mile (Five Minute Walk-FMW) is a must to encourage sustainable public transportation. Study shows that average speed and reliability of dedicated modes (like Metro, PRT, BRT, etc.) is high compared to road vehicles. Electric vehicles and more so battery-less or 3rd rail vehicles reduce pollution. One potential mode can be Cycleloop PRT, where commuter rides e-cycle in a dedicated path – elevated, at grade or underground. e-Bike with kerb weight per rider at 15 kg being 1/50th of car or 1/10th of other PRT systems makes it sustainable mode. Cycleloop tube will be light, sleek and scalable and can be modular erected, either on modified street lamp-posts or can be hanged/suspended between the two stations. Embarking and dis-embarking points or offline stations can be at an interval which suits FMW to mass public transit. In terms of convenience, guided e-Bike can be made self-balancing thus encouraging driverless on-demand vehicles. e-Bike equipped with smart electronics and drive controls can intelligently respond to field sensors and autonomously move reacting to Central Controller. Smart switching allows travel from origin to destination without interchange of cycles. DC Powered Batteryless e-cycle with voluntary manual pedaling makes it sustainable and provides health benefits. Tandem e-bike, smart switching and Platoon operations algorithm options provide superior through-put of the Cycleloop. Thus Cycleloop PRT will be exhaustive, intensive, convenient, reliable, speedy, sustainable, safe, pollution-free and healthy alternative mode for last mile connectivity in cities.

Keywords: cycleloop PRT, five-minute walk, lean modular infrastructure, self-balanced intelligent e-cycle

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Authors: Xize Dai, Jian Hao, Claus Leth Bak, Gian Carlo Montanari, Huai Wang

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Printed Circuit Board (PCB) is a critical component applicable to power electronics systems, especially for high-voltage applications involving several high-voltage and high-frequency SiC/GaN devices. The insulation system of PCB is facing more challenges from high-voltage and high-frequency stress that can alter the dielectric properties. Dielectric properties of the PCB insulation system also determine the electrical field distribution that correlates with intrinsic and extrinsic aging mechanisms. Hence, investigating the dielectric properties in the frequency domain of the PCB insulation system is a must. The paper presents the frequency-dependent, temperature-dependent, and voltage-dependent dielectric properties, permittivity, conductivity, and dielectric loss tangents of PCB insulation systems. The dielectric properties mechanisms associated with frequency, temperature, and voltage are revealed from the design perspective. It can be concluded that the dielectric properties of PCB in the frequency domain show a strong dependence on voltage, frequency, and temperature. The voltage-, frequency-, and temperature-dependent dielectric properties are associated with intrinsic conduction behavior and polarization patterns from the perspective of dielectric theory. The results may provide some reference for the PCB insulation system design in high voltage, high frequency, and high-temperature power electronics applications.

Keywords: electrical insulation system, dielectric properties, high voltage and frequency, printed circuit board

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Authors: Zoltan Sebestyen, Eszter Barta-Rajnai, Emma Jakab, Zsuzsanna Czegeny

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Extraction of the energy content of lignocellulosic biomass is one of the possible pathways to reduce the greenhouse gas emission derived from the burning of the fossil fuels. The application of the bioenergy can mitigate the energy dependency of a country from the foreign natural gas and the petroleum. The diversity of the plant materials makes difficult the utilization of the raw biomass in power plants. This problem can be overcome by the application of thermochemical techniques. Pyrolysis is the thermal decomposition of the raw materials under inert atmosphere at high temperatures, which produces pyrolysis gas, biooil and charcoal. The energy content of these products can be exploited by further utilization. The differences in the chemical and physical properties of the raw biomass materials can be reduced by the use of torrefaction. Torrefaction is a promising mild thermal pretreatment method performed at temperatures between 200 and 300 °C in an inert atmosphere. The goal of the pretreatment from a chemical point of view is the removal of water and the acidic groups of hemicelluloses or the whole hemicellulose fraction with minor degradation of cellulose and lignin in the biomass. Thus, the stability of biomass against biodegradation increases, while its energy density increases. The volume of the raw materials decreases so the expenses of the transportation and the storage are reduced as well. Biooil is the major product during pyrolysis and an important by-product during torrefaction of biomass. The composition of biooil mostly depends on the quality of the raw materials and the applied temperature. In this work, thermoanalytical techniques have been used to study the qualitative and quantitative composition of the pyrolysis and torrefaction oils of a woody (black locust) and two herbaceous samples (rape straw and wheat straw). The biooil contains C5 and C6 anhydrosugar molecules, as well as aromatic compounds originating from hemicellulose, cellulose, and lignin, respectively. In this study, special emphasis was placed on the formation of the lignin monomeric products. The structure of the lignin fraction is different in the wood and in the herbaceous plants. According to the thermoanalytical studies the decomposition of lignin starts above 200 °C and ends at about 500 °C. The lignin monomers are present among the components of the torrefaction oil even at relatively low temperatures. We established that the concentration and the composition of the lignin products vary significantly with the applied temperature indicating that different decomposition mechanisms dominate at low and high temperatures. The evolutions of decomposition products as well as the thermal stability of the samples were measured by thermogravimetry/mass spectrometry (TG/MS). The differences in the structure of the lignin products of woody and herbaceous samples were characterized by the method of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). As a statistical method, principal component analysis (PCA) has been used to find correlation between the composition of lignin products of the biooil and the applied temperatures.

Keywords: pyrolysis, torrefaction, biooil, lignin

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Authors: Mohammad A. Sazzad, Md M. Alam

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Wind energy is one of the cleanest form of renewable energy. Despite wind industry is growing faster than ever there are some roadblocks towards the improvement. One of the difficulties the industry facing is insufficient knowledge about wake within the wind farms. As we know energy is generated in the lowest layer of the atmospheric boundary layer (ABL). This interaction between the wind turbine (WT) blades and wind introduces a low speed wind region which is defined as wake. This wake region shows different characteristics under each stability condition of the ABL. So, it is fundamental to know this wake region well which is defined mainly by turbulence transport and wake shear. Defining the wake recovery length and width are very crucial for wind farm to optimize the generation and reduce the waste of power to the grid. Therefore, in order to obtain the turbulent coefficients of velocity and length, this research focused on the large eddy simulation (LES) data for neutral ABL (NABL). According to turbulent theory, if we can present velocity defect and Reynolds stress in the form of local length and velocity scales, they become invariant. In our study velocity and length coefficients are 0.4867 and 0.4794 respectively which is close to the theoretical value of 0.5 for NABL. There are some invariant profiles because of the presence of thermal and wind shear power coefficients varied a little from the ideal condition.

Keywords: atmospheric boundary layer, renewable energy, turbulent coefficient, wind turbine, wake

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Authors: Venuka Kuruwita Arachchige Don, Mohamed Shaheen, Chris Goodier

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Aerated autoclaved concrete (AAC) is known for its lightweight, easy handling, high thermal insulation, and extremely porous structure. Investigation of pore behavior in AAC is crucial for characterizing the material, standardizing design and production techniques, enhancing the mechanical, durability, and thermal performance, studying the effectiveness of protective measures, and analyzing the effects of weather conditions. The significant details of pores are complicated to observe with acknowledged accuracy. The High-resolution Field Emission Scanning Electron Microscope (FESEM) image analysis is a promising technique for investigating the pore behavior and density of AAC, which is adopted in this study. Mercury intrusion porosimeter and gas pycnometer were employed to characterize porosity distribution and density parameters. The analysis considered three different densities of AAC blocks and three layers in the altitude direction within each block. A set of understandings was presented to extract and analyze the details of pore shape, pore size, pore connectivity, and pore percentages from FESEM images of AAC. Average pore behavior outcomes per unit area were presented. Comparison of porosity distribution and density parameters revealed significant variations. FESEM imaging offered unparalleled insights into porosity behavior, surpassing the capabilities of other techniques. The analysis conducted from a multi-staged approach provides porosity percentage occupied by various pore categories, total porosity, variation of pore distribution compared to AAC densities and layers, number of two-dimensional and three-dimensional pores, variation of apparent and matrix densities concerning pore behaviors, variation of pore behavior with respect to aluminum content, and relationship among shape, diameter, connectivity, and percentage in each pore classification.

Keywords: autoclaved aerated concrete, density, imaging technique, microstructure, porosity behavior

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Authors: Karen L. Middlemiss, Denham G. Cook, Peter Jaksons, Alistair Jerrett, William Davison

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Lateralisation of cognitive function is a common phenomenon found throughout the animal kingdom. Strong biases in functional behaviours have evolved from asymmetrical brain hemispheres which differ in structure and/or cognitive function. In fish, lateralisation is involved in visually mediated behaviours such as schooling, predator avoidance, and foraging, and is considered to have a direct impact on species fitness. Currently, there is very little literature on the role of lateralisation in fish schools. The yellow-eyed mullet (Aldrichetta forsteri), is an estuarine and coastal species found commonly throughout temperate regions of Australia and New Zealand. This study sought to quantify visually mediated behaviours in yellow-eyed mullet to identify the significance of lateralisation, and the factors which influence functional behaviours in schooling fish. Our approach to study design was to conduct a series of tank based experiments investigating; a) individual and population level lateralisation, b) schooling behaviour, and d) optic lobe anatomy. Yellow-eyed mullet showed individual variation in direction and strength of lateralisation in juveniles, and trait specific spatial positioning within the school was evidenced in strongly lateralised fish. In combination with observed differences in schooling behaviour, the possibility of ontogenetic plasticity in both behavioural lateralisation and optic lobe morphology in adults is suggested. These findings highlight the need for research into the genetic and environmental factors (epigenetics) which drive functional behaviours such as schooling, feeding and aggression. Improved knowledge on collective behaviour could have significant benefits to captive rearing programmes through improved culture techniques and will add to the limited body of knowledge on the complex ecophysiological interactions present in our inshore fisheries.

Keywords: cerebral asymmetry, fisheries, schooling, visual bias

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Authors: Vakhtang Charaia, Mariam Lashkhi

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Foreign direct investment (FDI) plays a vital role in global business. It provides firms with new markets and advertising channels, cheaper production facilities, admission to new technology, products, skills and financing. FDI can provide a recipient country/company with a source of new technologies, capital, practice, products, management skills, and as such can be a powerful drive for economic development. It is one of the key elements of stable economic development in many countries, especially in developing ones. Therefore the size of FDI inflow is one of the most crustal factors for economic perfection in small economy countries (like, Georgia), while most of developed ones are net exporters of FDI. Since, FDI provides firms with new markets; admission to new technologies, products and management skills; marketing channels; cheaper production facilities, and financing opportunities. It plays a significant role in Georgian economic development. Increasing FDI inflows from all over the world to Georgia in last decade was achieved with the outstanding reforms managed by the Georgian government. However, such important phenomenon as world financial crisis and Georgian-Russian war put its consequence on the over amount of FDI inflow in Georgia in the last years. It is important to mention that the biggest investor region for Georgia is EU, which is interested in Georgia not only from the economic points of view but from political. The case studies from main EU investor countries show that Georgia has a big potential of investment in different areas, such as; financial sector, energy, construction, tourism industry, transport and communications. Moreover, signing of Association Agreement between Georgia and EU will further boost all the fields of economy in Georgia in both short and long terms. It will attract more investments from different countries and especially from EU. The last, but not least important issue is the calculation of annual FDI inflow to Georgia, which it is calculated differently by different organizations, based on different methodologies, but what is more important is that all of them show significant increase of FDI in last decade, which gives a positive signal to investors and underlines necessity of further improvement of investment climate in the same direction.

Keywords: foreign direct investment (FDI), Georgia, investment development path, investment climate

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Authors: Liyun Chang, Cheng-Hsiang Tsai

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To ensure the radiation precisely delivering to the target of cancer patients, the linear accelerator equipped with the pretreatment on-board imaging system is introduced and through it the patient setup is verified before the daily treatment. New generation radiotherapy using beam-intensity modulation, usually associated the treatment with steep dose gradients, claimed to have achieved both a higher degree of dose conformation in the targets and a further reduction of toxicity in normal tissues. However, this benefit is counterproductive if the beam is delivered imprecisely. To avoid shooting critical organs or normal tissues rather than the target, it is very important to carry out the quality assurance (QA) of this on-board imaging system. The QA of the On-Board Imager® (OBI) system of one Varian Clinac-iX linear accelerator was performed through our procedures modified from a relevant report and AAPM TG142. Two image modalities, 2D radiography and 3D cone-beam computed tomography (CBCT), of the OBI system were examined. The daily and monthly QA was executed for five months in the categories of safety, geometrical accuracy and image quality. A marker phantom and a blade calibration plate were used for the QA of geometrical accuracy, while the Leeds phantom and Catphan 504 phantom were used in the QA of radiographic and CBCT image quality, respectively. The reference images were generated through a GE LightSpeed CT simulator with an ADAC Pinnacle treatment planning system. Finally, the image quality was analyzed via an OsiriX medical imaging system. For the geometrical accuracy test, the average deviations of the OBI isocenter in each direction are less than 0.6 mm with uncertainties less than 0.2 mm, while all the other items have the displacements less than 1 mm. For radiographic image quality, the spatial resolution is 1.6 lp/cm with contrasts less than 2.2%. The spatial resolution, low contrast, and HU homogenous of CBCT are larger than 6 lp/cm, less than 1% and within 20 HU, respectively. All tests are within the criteria, except the HU value of Teflon measured with the full fan mode exceeding the suggested value that could be due to itself high HU value and needed to be rechecked. The OBI system in our facility was then demonstrated to be reliable with stable image quality. The QA of OBI system is really necessary to achieve the best treatment for a patient.

Keywords: CBCT, image quality, quality assurance, OBI

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Authors: Ashish Kumar Pathak, Ritika Sharma, Vishal Nath, Sudhir Pratap Singh, Rakesh Tuli

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Litchi is a sub-tropical fruit crop with genotypes bearing delicious juicy fruits with variable seed size (bold to rudimentary size). Small seed size is a desirable trait in litchi, as it increases consumer acceptance and fruit processing. The biochemical activities in mid- stage ovules (e.g. 16, 20, 24 and 28 days after anthesis) determine the fate of seed and fruit development in litchi. Comprehensive ovule-specific transcriptome analysis was performed in two litchi genotypes with contrasting seed size to gain molecular insight on determinants of seed fates in litchi fruits. The transcriptomic data was de-novo assembled in 1,39,608 trinity transcripts, out of which 6,325 trinity transcripts were differentially expressed between the two contrasting genotypes. Differential transcriptional pattern was found among ovule development stages in contrasting litchi genotypes. The putative genes for salicylic acid, jasmonic acid and brassinosteroid pathway were down-regulated in ovules of small-seeded litchi. Embryogenesis, cell expansion, seed size and stress related trinity transcripts exhibited altered expression in small-seeded genotype. The putative regulators of seed maturation and seed storage were down-regulated in small-seed genotype.

Keywords: Litchi, seed, transcriptome, defence

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Authors: Romuald Temomo Wamba, Robert Wanda

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The issue of creative accounting in the psychological and sociological framework has been a mixed subject for over 60 years. The objective of this article is to ensure the existence of creative accounting in Cameroonian entities on the one hand and to understand the strategies used by audit agents to detect errors, omissions, irregularities, or inadequacies in the financial state; optimization techniques used by account preparers to strategically bypass texts on the other hand. To achieve this, we conducted an exploratory study using a cognitive approach, and the data analysis was performed by the software 'decision explorer'. The results obtained challenge the authors' cognition (manifest latent and deceptive behavior). The tax inspectors stress that the entities in Cameroon do not derogate from the rules of piloting in the financial statements. Likewise, they claim a change in current income and net income through depreciation, provisions, inventories, and the spreading of charges over long periods. This suggests the suspicion or intention of manipulating the financial statements. As for the techniques, the account preparers manage the accruals at the end of the year as the basis of the practice of creative accounting. Likewise, management accounts are more favorable to results management.

Keywords: creative accounting, sociocognitive approach, psychological and sociological approach, cognitive dissonance theory, cognitive mapping

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Authors: John Cheferson R. De Belen, John Paul G. Elizares, Ronald John G. Raz, Janina Elyse A. Reyes, Charie G. Salengua, Aristotle L. Soriano

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Plastic is a type of synthetic or man-made polymer that can readily be molded into a variety of products. Its usage over the past century has enabled society to make huge technological advances. The workers of United Asia International Plastics Corporation (UAIPC), a plastic manufacturing company performs manual packaging which causes fatigue and stress on their arm, neck, and legs due to extended periods of standing and repetitive motions. With the use of the Fishbone Diagram, Five-Why Analysis, Rapid Entire Body Assessment (REBA), and Anthropometry, the stressful tasks and activities were identified and analyzed. Given the anthropometric measurements obtained from the workers, improved dimensions for the tables and chairs should be used and provide a new packaging machine. The validation of this proposal shall follow after its implementation. By eliminating fatigue during working hours in the production, the workers will be at ease at performing their work properly; productivity will increase that will lead to more profit. Further areas for study include measurement and comparison of the worker’s anthropometric measurement with the industry standard.

Keywords: anthropometry, fishbone diagram, five-why analysis, rapid entire body assessment

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Authors: Abigail Amoah, George Ofori, George Agyekum-Mensah, Matthew Brian Wright, Job Momoh

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The objective of this study was to examine the mental health triggers, challenges, and support for mental health needs within the UK construction industry, which is seen as one of the high-pressure working environments with jobs that can be physically demanding and, traditionally, suffer from ‘Macho’ culture. The sector makes a substantial contribution to the UK’s economy, but despite this economic significance, mental health issues are still thoroughly attended to due to stigmatisation. Through semi-structured interviews with clients, consultants, and contractors, the research helps to understand better how mental health is perceived by these key stakeholders in the UK construction industry. Clients identify high-pressure deadlines and financial risks as major stressors, consultants point to the incessant workload culture coupled with project constraints, and contractors emphasize insufficient resource concerns and physical demands. this study reveals significant organisational and cultural barriers to mental health. The study proposes the following recommendations: the need to implement bespoke mental health programmes for the industry, better communication channels, and implementing industry-standard policies to enhance a supportive environment. These specifications provide actionable insights to support well-being and productivity within the sector.

Keywords: construction industry, mental health, supportive mechanisms, workplace stress

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Authors: Franklin Nakpodia, Femi Olan

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A blend of internal factors (firm performance, internal stakeholders) and external pressures (globalisation, technology, corporate scandals) have intensified calls for corporate governance reforms. While several countries and their governments have responded to these calls, the effect of such reforms on corporate governance systems across countries remains mixed. In particular, the literature reports that the effectiveness of corporate governance interventions in many developing economies is limited. Relying on the corporate governance system in Africa’s largest economy (Nigeria), this research addresses two issues. First, this study explores why previous corporate governance reforms have failed and second, the article investigates what reforms could improve corporate governance practices in the country. In addressing the above objectives, this study adopts a qualitative approach that permits data collection via semi-structured interviews with 21 corporate executives. The data supports the articulation of two sequential levels of reforms (i.e., the upstream and downstream reforms). The upstream reforms focus on two crucial but often overlooked areas that undermine reform effectiveness, i.e., the extent of government commitment and an enabling environment. The downstream reforms combine awareness and regulatory elements to proffer a path to robust corporate governance in the country. Furthermore, findings from this study stress the need to consider the use of a bottom-up approach to corporate governance practice and policymaking in place of the dominant top-down strategy.

Keywords: bottom-up approach, corporate governance, reforms, regulation

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Authors: Valentina Di Maria, Anton Ianakiev

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The use of adhesive anchors for wooden constructions is an efficient technology to connect and design timber members in new timber structures and to rehabilitate the damaged structural members of historical buildings. Due to the lack of standard regulation in this specific area of structural design, designers’ choices are still supported by test analysis that enables knowledge, and the prediction, of the structural behavior of glued in rod joints. The paper outlines an experimental research activity aimed at identifying the tensile resistance capacity of several new adhesive joint prototypes made of epoxy resin, steel bar and timber, Oak and Douglas Fir species. The development of new adhesive connectors has been carried out by using epoxy to glue stainless steel bars into pre-drilled holes, characterized by smooth and rough internal surfaces, in timber samples. The realization of a threaded contact surface using a specific drill bit has led to an improved bond between wood and epoxy. The applied changes have also reduced the cost of the joints’ production. The paper presents the results of this parametric analysis and a Finite Element analysis that enables identification and study of the internal stress distribution in the proposed adhesive anchors.

Keywords: glued in rod joints, adhesive anchors, timber, epoxy, rough contact surface, threaded hole shape

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Authors: Sao-Jeng Chao, Wen-Cheng Chen, Wei-Humg Lu

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In order to prevent encountering unpredictable factors, geotechnical engineers always conduct numerical analysis for braced excavation design. Simulation work in advance can predict the response of subsequent excavation and thus will be designed to increase the security coefficient of construction. The parameters that are considered include geological conditions, soil properties, soil distributions, loading types, and the analysis and design methods. National Ilan University is located on the LanYang plain, mainly deposited by clayey soil and loose sand, and thus is vulnerable to external influence displacement. National Ilan University experienced a construction of braced excavation with a complete program of monitoring excavation. This study takes advantage of a one-dimensional finite element method RIDO to simulate the excavation process. The predicted results from numerical simulation analysis are compared with the monitored results of construction to explore the differences between them. Numerical simulation analysis of the excavation process can be used to analyze retaining structures for the purpose of understanding the relationship between the displacement and supporting system. The resulting deformation and stress distribution from the braced excavation cab then be understand in advance. The problems can be prevented prior to the construction process, and thus acquire all the affected important factors during design and construction.

Keywords: excavation, numerical simulation, RIDO, retaining structure

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Authors: Eric S. Lee, Connie Bygrave, Jordan Mahar, Naina Garg, Suzanne Cottreau

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Marking exams is universally detested by lecturers. Final exams in many higher education courses often last 3.0 hrs. Do exams really need to be so long? Can we justifiably reduce the number of questions on them? Surprisingly few have researched these questions, arguably because of the complexity and difficulty of using traditional methods. To answer these questions empirically, we used a new approach based on three key elements: Use of an unusual variation of a true experimental design, equivalence hypothesis testing, and an expanded set of six psychometric criteria to be met by any shortened exam if it is to replace a current 3.0-hr exam (reliability, validity, justifiability, number of exam questions, correspondence, and equivalence). We compared student performance on each official 3.0-hr exam with that on five shortened exams having proportionately fewer questions (2.5, 2.0, 1.5, 1.0, and 0.5 hours) in a series of four experiments conducted in two classes in each of two finance courses (224 students in total). We found strong evidence that, in these courses, shortening of final exams to 2.0 hrs was warranted on all six psychometric criteria. Shortening these exams by one hour should result in a substantial one-third reduction in lecturer time and effort spent marking, lower student stress, and more time for students to prepare for other exams. Our approach provides a relatively simple, easy-to-use methodology that lecturers can use to examine the effect of shortening their own exams.

Keywords: exam length, psychometric criteria, synthetic experimental designs, test length

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Authors: Bhavini Patel, Aslihan Ugun-Klusek, Ellen Billet

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The two main contributing factors to familial and idiopathic form of Parkinson’s disease (PD) are oxidative stress and altered proteolysis. Monoamine oxidase-A (MAO-A) plays a significant role in redox homeostasis by producing reactive oxygen species (ROS) via deamination of for example, dopamine. The ROS generated induces chemical modification of proteins resulting in altered biological function. The ubiquitin-proteasome system, which consists of three different types or proteolytic activity, namely “chymotrypsin-like” activity (CLA), “trypsin-like” activity (TLA) and “post acidic-like” activity (PLA), is responsible for the degradation of ubiquitinated proteins. Defects in UPS are known to be strongly correlated to PD. Herein, the effect of ROS generated by MAO-A on proteasome activity and the effects of proteasome inhibition on MAO-A protein levels in WT, mock and MAO-A overexpressed (MAO-A+) SHSY5Y neuroblastoma cell lines were investigated. The data in this study report increased proteolytic activity when MAO-A protein levels are significantly increased, in particular CLA and PLA. Additionally, 20S proteasome inhibition induced a decrease in MAO-A levels in WT and mock cells in comparison to MAO-A+ cells in which 20S proteasome inhibition induced increased MAO-A levels to be further increased at 48 hours of inhibition. This study supports the fact that MAO-A could be a potential pharmaceutical target for neuronal protection as data suggests that endogenous MAO-A levels may be essential for modulating cell death and survival.

Keywords: monoamine oxidase, neurodegeneration, Parkinson's disease, proteasome

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Authors: Vikrant Sinha, Himanshu Singh, Nitish Kumar Singh, Sujal Nag

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This research creates an urgent and complex challenge for marine ecosystems. Microplastics were primarily found on land, but now they are pervasive in marine environments as well, affecting a wide range of marine species, from zooplankton to larger mammals that live in those environments. These pollutants interfere with major biological processes like feeding and reproduction, causing disruption throughout the food web as microplastics are getting accumulated at different tropic levels. Meanwhile, climatic changes made these effects more accelerated, and the concentration of microplastics due to these occurrences is increasing day by day. Rising temperatures, melting ice, increased runoff due to rainfall, and shifting wind patterns are transforming marine life in a way that intensifies the burden on marine life. This dual stress is particularly present in fragile ecosystems of marine life, such as coral reefs and mangroves. Addressing this twisted crisis requires not only efforts to restrain plastic pollution but also adapts strategies for climate mitigation. This research emphasizes the critical need to combine approaches to save marine biodiversity and withstand the rapid changes in the environment.

Keywords: microplastic pollution, climate change impacts, marine ecosystems, biodiversity threats, zooplankton ingestion, trophic accumulation, coral reef degradation, ecosystem resilience, plastic pollution mitigation, climate adaptation strategies, SST, sea surface temperature

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Authors: Elham Zarenezhad, Ali Zarenezhad, Mehdi Mardkhoshnood

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We described the synthesis and biological study of O-oxime ethers having a-amino acid residues as new analogs of IPS-339. In this synthesis, the reaction of fluorene O-oxime with epichlorohydrin or epibromohydrin afforded the corresponding O-oxime ether adducts. The N-alkylation of valine amino acid with O-oxime ether adducts led to the synthesis of new analogs of IPS-339. The cardiovascular properties of the compound have been studied. In this regard, six clinically healthy same sex mongrel dogs were examined. The dogs were randomly divided into 3 groups of two members. 1 groups received 2 mg kg-1 body weight of compound (2-(3-(9H-fluoren-9-ylideneaminooxy)-2- hydroxypropylamino)-3-methylbutanoic acid) intravenously, whereas group 2 and 3 received only DMSO–water (distil.) and propranolol (Inderal) (2 mg kg-1), respectively. The electrocardiograph (ECG) was recorded with lead II. The recording was run successively by 5 min time interval on each dog before, simultaneously, and after compound infusion. Data after administration were taken from normal sinus beats that were closely related to the arrhythmias whenever they occurred. In general, no detectable arrhythmia was observed in all ECG records regardless of increasing the heart rate that likely caused by stress origin from invasive procedure just after infusion. Compound diminished the heart rate during study especially at 20th minute compared to propranolol as a reference drug. Compound (2-(3-(9H-fluoren-9-ylideneaminooxy)-2- hydroxypropylamino)-3-methylbutanoic acid) was the most effective compound with remarkable ability in declining of the heart rate.

Keywords: electrocardiograph (ECG), cardiovascular, IPS-339, dogs

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Authors: Sinan Bilgen, Bekir Ozer Ay, Nilay Sezer Uzol

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After decades of conventional shapes, irregular forms with complex geometries are getting more popular for form generation of tall buildings all over the world. This trend has recently brought out diverse building forms such as twisting tall buildings. This study investigates both the aerodynamic and design features of twisting tall buildings through comparative analyses. Since twisting a tall building give rise to additional complexities related with the form and structural system, lateral load effects become of greater importance on these buildings. The aim of this study is to analyze the inherent characteristics of these iconic forms by comparing the wind loads on twisting tall buildings with those on their prismatic twins. Through a case study research, aerodynamic analyses of an existing twisting tall building and its prismatic counterpart were performed and the results have been compared. The prismatic twin of the original building were generated by removing the progressive rotation of its floors with the same plan area and story height. Performance-based measures under investigation have been evaluated in conjunction with the architectural design. Aerodynamic effects have been analyzed by both wind tunnel tests and computational methods. High frequency base balance tests and pressure measurements on 3D models were performed to evaluate wind load effects on a global and local scale. Comparisons of flat and real surface models were conducted to further evaluate the effects of the twisting form without façade texture contribution. Comparisons highlighted that, the twisting form under investigation shows better aerodynamic behavior both for along wind but particularly for across wind direction. Compared to the prismatic counterpart; twisting model is superior on reducing vortex-shedding dynamic response by disorganizing the wind vortices. Consequently, despite the difficulties arisen from inherent complexity of twisted forms, they could still be feasible and viable with their attractive images in the realm of tall buildings.

Keywords: aerodynamic tests, motivation for twisting, tall buildings, twisted forms, wind excitation

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Authors: M. Linda Phooko, Phesheya E. Dlamini, Vusumuzi E. Mbanjwa, Rhandu Chauke

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The decline of yields as a consequence of miss-informed land-use decisions poses a threat to sustainable agriculture in South Africa. The non-uniform growth pattern of wheat crop and the yields below expectations has been one of the main concerns for Timatjatji community farmers. This study was then conducted to characterize, classify, and evaluate soils of the farm for sustainable land use planning. A detailed free survey guided by surface features was conducted on a 25 ha farm to check soil variation. It was revealed that Sepane (25%), Bonheim (21%), Rensburg (18%), Katspruit (15%), Arcadia (12%) and Dundee (9%) were the dominant soil forms found across the farm. Field soil description was done to determine morphological characteristics of the soils which were matched with slope percentage and climate to assess the potential of the soils. The land capability results showed that soils were generally shallow due to high clay content in the B horizon. When the climate of the area was factored in (i.e. land potential), it further revealed that the area has low cropping potential due to heat, moisture stress and shallow soils. This implies that the farm is not suitable for annual cropping but can be highly suitable for planted pastures.

Keywords: characterization, land capability, land evaluation, land potential

Procedia PDF Downloads 199

Authors: Nathan Moran, Robert Hanser, Attapol Kuanliang

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The purpose of this study is to determine the relationship between personal and social resources and burnout for police officers. Current conceptualizations of the condition of burnout are challenged as being too phenomenological and ambiguous, and consequently, not given to direct empirical testing. The conservation of resources model is based on the supposition that people strive to retain, protect, and build resources as a means to protect them from the impacts of burnout. The model proposes that the effects of stress (i.e. burnout) can be manifested in personal and professional attitudes and attributes, which can measure burnout using self-reports to provide strong support for the conservation of resources model, in that, personal and professional demands are related to the exhaustion component of burnout, whereas personal and professional resources can be compiled to counteract the negative impact of the burnout condition. Highly similar patterns of burnout resistance factors were witnessed in police officers in two department precincts (N:81). In addition, results confirmed the positive influence of key demographic variables in burnout resistance using the conservation of resources model. Participants in this study are all sheriff’s deputies with a populous county in a Pacific Northwestern state (N = 274). Four instruments will be used in this quantitative study for data collection (a) a series of demographic questions, (b) the Organizational Citizenship Behavior, (c) the PANAS-X Scale (OCB: Watson& Clark, 1994), and (d) The Maslach Burnout Inventory.

Keywords: behavioral, burnout, law enforcement, quantitative

Procedia PDF Downloads 286

Authors: Ihejirika Chinedu Emeka, Njoku John Didacus, Obenade Moses

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This study was aimed at determining the impact of meteorological events (seasonal variations) and sand excavation activities on turbidity and Total Suspended Solids (TSS) of Imo River, Southeastern Nigeria. In-situ measurements of the parameters were carried out at the peaks of two consecutive seasons–dry and rainy season at seven major points of sand excavation along the river, under standard analytical methods. There were significant variations in seasons (P<0.05) for turbidity and TSS at all locations. The average turbidity concentration of locations were 36.71 NTU, during the rainy season, and 17 NTU in a dry season, while the average TSS concentration were 27.14 mg/L, during the rainy season, and 8.86mg/L in a dry season. Turbidity correlated positively (strongly) with TSS (r=0.956) at R–Square=0.91. Turbidity and TSS values were higher during the rainy season than the dry season. Turbidity increased when Total Suspended Solids increased. Sand excavation increased turbidity and TSS values of Imo River. The river had moderate water quality during the rainy season and unimpaired water quality during a dry season. The river was not very clear in both seasons, but clearer in a dry season than in rainy season. The increase in turbidity and TSS can lead to the destruction of aquatic biodiversity and stagnation of ecosystem processes. Exposure of aquatic animals to the recorded turbidity level in a rainy season can lead to stress.

Keywords: biodiversity destruction, meteorological events, pollution, sand excavation

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Authors: Y. S. Mohamed, L. A. Ahmed, H. A. Salem, A. M. Agha

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Liver Fibrosis is one of the most serious conditions that affect the Egyptian society. In the present study, the effect of nicorandil was investigated in experimentally-induced liver fibrosis by bile duct ligation in rats. Nicorandil (3mg/kg/day) was given orally 24 h after bile duct ligation for 14 days till the end of the experiment. Nicorandil group showed a significant improvement in liver function tests (ALT and ALP) as well as a significant decrease in oxidative stress biomarkers (TBARS and GSH), area of fibrosis and activity of hepatic stellate cells as indicated by decreased expression of alpha smooth muscle actin.Moreover, nicorandil treatment decreased HSCs proliferation due to its inhibitory effects on protein kinase C(PKC) and Platelet derived growth factor (PDGF) . Oral administration of either glibenclamide (10 mg/kg/day)(a KATP channel blocker) or L-NAME (30 mg/kg/day) (an inhibitor of nitric oxide synthase) blocked the protective effects of nicorandil. However, nicorandil and L-NAME treated group showed more or less results similar to that of untreated bile duct ligated group. In conclusion, nicorandil was effective against the development of bile duct ligated-induced liver fibrosis in rats where activation of the NO pathway plays an important role in the protective effect nicorandil.

Keywords: hepatic stellate cells, nicorandil, nitric oxide donor, liver fibrosis

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Authors: Claire Norman-Maillet

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Insider fraud, including its various synonyms such as occupational, employee or internal fraud, is a major financial crime threat whereby an employee defrauds (or attempts to defraud) their current, prospective, or past employer. ‘Employee’ covers anyone employed by the company, including contractors, directors, and part time staff; they may be a solo bad actor or working in collusion with others, whether internal or external. Insider fraud is even more of a concern given the impacts of the Coronavirus pandemic, which has generated multiple opportunities to commit insider fraud. Insider fraud is something that is not necessarily thought of as a significant financial crime threat; the focus of most academics and practitioners has historically been on that of ‘external fraud’ against businesses or entities where an individual or group has no professional ties. Without the face-to-face, ‘over the shoulder’ capabilities of staff being able to keep an eye on their employees, there is a heightened reliance on trust and transparency. With this, naturally, comes an increased risk of insider fraud perpetration. The objective of the research is to better understand how companies are impacted by insider fraud, and therefore how to stop it. This research will make both an original contribution and stimulate debate within the financial crime field. The financial crime landscape is never static – criminals are always creating new ways to perpetrate financial crime, and new legislation and regulations are implemented as attempts to strengthen controls, in addition to businesses doing what they can internally to detect and prevent it. By focusing on insider fraud specifically, the research will be more specific and will be of greater use to those in the field. To achieve the aims of the research, semi-structured interviews were conducted with 22 individuals who either work in financial services and deal with insider fraud or work within insider fraud perpetration in a recruitment or advisory capacity. This was to enable the sourcing of information from a wide range of individuals in a setting where they were able to elaborate on their answers. The principal recruitment strategy was engaging with the researcher’s network on LinkedIn. The interviews were then transcribed and analysed thematically. Main findings in the research suggest that insider fraud has been ignored owing to the denial of accepting the possibility that colleagues would defraud their employer. Whilst Coronavirus has led to a significant rise in insider fraud, this type of crime has been a major risk to businesses since their inception, however have never been given the financial or strategic backing required to be mitigated, until it's too late. Furthermore, Coronavirus should have led to companies tightening their access rights, controls and policies to mitigate the insider fraud risk. However, in most cases this has not happened. The research concludes that insider fraud needs to be given a platform upon which to be recognised as a threat to any company and given the same level of weighting and attention by Executive Committees and Boards as other types of economic crime.

Keywords: fraud, insider fraud, economic crime, coronavirus, Covid-19

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Authors: Mona Marzouk, Nesrine Hegazi, Aliaa Ragheb, Mona El Shabrawy, Salwa Kawashty

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The whole plant of Matthiola longipetala (Brassicaceae) was extracted by 70% methanol to give the total aqueous methanol extract (AME), which was defatted by hexane yielded hexane extract (HE) and defatted AME (DAME). HE was analyzed through GC/MS assay and revealed the detection of 28 non-polar compounds. In addition, the chemical investigation of DAME led to the isolation and purification of twelve flavonoids and three chlorogenic acids. Their structures were interpreted through chemical (complete and partial acid hydrolysis) and spectroscopic analysis (MS, UV, 1D and 2D NMR). Among them, nine compounds have been isolated for the first time from M. longipetala. Moreover, LC-ESI-MS analysis of DAME was achieved to detect additional 46 metabolites, including phospholipids, organic acids, phenolic acids and flavonoids. The biological activity of AME, HE and DAME against alloxan inducing oxidative stress and diabetes in male rats was investigated. Diabetes was induced using a single dose of Alloxan (150 mg/kg b.wt.). HE and DAME significantly increased serum GSH content in rats (37.3±0.7 and 35.9±0.6 mmol/l) compared to diabetic rats (21.8±0.3) and vitamin E (36.2±1.1) at P<0.01. Also, HE, DAME and AME revealed a significant acute anti-hyperglycemic effect potentiated after four weeks of treatment with blood glucose levels of 96.2±5.4, 98.7±6.1 and 98.9±8.6 mg/dl, respectively, compared to diabetic rats (263.4±7.8) and metaformin group (81.9±2.4) at P<0.01.

Keywords: Brassicaceae, Flavonoid, LCMS/MS, Matthiola

Procedia PDF Downloads 183