Search results for: mixed effects models
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 18272

Search results for: mixed effects models

11732 A Cohort and Empirical Based Multivariate Mortality Model

Authors: Jeffrey Tzu-Hao Tsai, Yi-Shan Wong

Abstract:

This article proposes a cohort-age-period (CAP) model to characterize multi-population mortality processes using cohort, age, and period variables. Distinct from the factor-based Lee-Carter-type decomposition mortality model, this approach is empirically based and includes the age, period, and cohort variables into the equation system. The model not only provides a fruitful intuition for explaining multivariate mortality change rates but also has a better performance in forecasting future patterns. Using the US and the UK mortality data and performing ten-year out-of-sample tests, our approach shows smaller mean square errors in both countries compared to the models in the literature.

Keywords: longevity risk, stochastic mortality model, multivariate mortality rate, risk management

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11731 Analysis of Aerodynamic Forces Acting on a Train Passing Through a Tornado

Authors: Masahiro Suzuki, Nobuyuki Okura

Abstract:

The crosswind effect on ground transportations has been extensively investigated for decades. The effect of tornado, however, has been hardly studied in spite of the fact that even heavy ground vehicles, namely, trains were overturned by tornadoes with casualties in the past. Therefore, aerodynamic effects of the tornado on the train were studied by several approaches in this study. First, an experimental facility was developed to clarify aerodynamic forces acting on a vehicle running through a tornado. Our experimental set-up consists of two apparatus. One is a tornado simulator, and the other is a moving model rig. PIV measurements showed that the tornado simulator can generate a swirling-flow field similar to those of the natural tornadoes. The flow field has the maximum tangential velocity of 7.4 m/s and the vortex core radius of 96 mm. The moving model rig makes a 1/40 scale model train of single-car/three-car unit run thorough the swirling flow with the maximum speed of 4.3 m/s. The model car has 72 pressure ports on its surface to estimate the aerodynamic forces. The experimental results show that the aerodynamic forces vary its magnitude and direction depends on the location of the vehicle in the flow field. Second, the aerodynamic forces on the train were estimated by using Rankin vortex model. The Rankin vortex model is a simple tornado model which widely used in the field of civil engineering. The estimated aerodynamic forces on the middle car were fairly good agreement with the experimental results. Effects of the vortex core radius and the path of the train on the aerodynamic forces were investigated using the Rankin vortex model. The results shows that the side and lift forces increases as the vortex core radius increases, while the yawing moment is maximum when the core radius is 0.3875 times of the car length. Third, a computational simulation was conducted to clarify the flow field around the train. The simulated results qualitatively agreed with the experimental ones.

Keywords: aerodynamic force, experimental method, tornado, train

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11730 Sublethal Effects of Thiamethoxam-Lambda Cyhalothrin on the Life Table Parameters and Population Projection of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) and Its Parasitoid, Encarsia formosa (Hymenoptera: Aphelinidae)

Authors: Sevda Ddras, Fariba Mehrkhou, Remzi Atlihan, Maryam Fourouzan

Abstract:

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is one of the most important pest on vegetables and ornamental host plants. In this research, the sub-lethal concentration (LC30) of thiamethoxam-lambda cyhalothrin (TLC) on the biological properties, life table parameters and population projection of T. vaporarium and its parasitoid, Encarsia formosa Gahan, were studied at controlled condition (25 ±5 ℃, R.H. 60 ±10 % and a photoperiod of 16:8 h (L:D). Bioassays were conducted by dipping tomato leaves containing third instar nymphs of the whitefly T. vaporariorum, in the obtained LC30 concentration of eforia. The life table data were analyzed using the computer program TWOSEX–MSChart based on the age-stage, two-sex life table theory. The results showed that, usage of sublethal concentration of TLC effected the biological properties and population growth parameters of greenhouse whitefly by shortening the developmentl time, adult longevity, decreasing the fecundity and population growth paramters. Also, the LC30 concentration of TLC had negative effects on life history and life table parameters of E.formosa. The obtained results illustrated that the sublethal concentration of TLC resulted in prolonging of developmental time, decreasing of adult longevity, survival rate and population growth parameters of E.formosa. Additionally, the population projection results were accordance with the population growth rate of either greenhouse whitefly or E.formosa. We conclude that, TLC should not be used in integrated pest management programs where E. formosa exists.

Keywords: greenhouse whitefly, Encarsia formosa, thiamethoxam-lambda cyhalothrin, population projection, life table parameters

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11729 Multi-Institutional Report on Toxicities of Concurrent Nivolumab and Radiation Therapy

Authors: Neha P. Amin, Maliha Zainib, Sean Parker, Malcolm Mattes

Abstract:

Purpose/Objectives: Combination immunotherapy (IT) and radiation therapy (RT) is an actively growing field of clinical investigation due to promising findings of synergistic effects from immune-mediated mechanisms observed in preclinical studies and clinical data from case reports of abscopal effects. While there are many ongoing trials of combined IT-RT, there are still limited data on toxicity and outcome optimization regarding RT dose, fractionation, and sequencing of RT with IT. Nivolumab (NIVO), an anti-PD-1 monoclonal antibody, has been rapidly adopted in the clinic over the past 2 years, resulting in more patients being considered for concurrent RT-NIVO. Knowledge about the toxicity profile of combined RT-NIVO is important for both the patient and physician when making educated treatment decisions. The acute toxicity profile of concurrent RT-NIVO was analyzed in this study. Materials/Methods: A retrospective review of all consecutive patients who received NIVO from 1/2015 to 5/2017 at 4 separate centers within two separate institutions was performed. Those patients who completed a course of RT from 1 day prior to initial NIVO infusion through 1 month after last NIVO infusion were considered to have received concurrent therapy and included in the subsequent analysis. Descriptive statistics are reported for patient/tumor/treatment characteristics and observed acute toxicities within 3 months of RT completion. Results: Among 261 patients who received NIVO, 46 (17.6%) received concurrent RT to 67 different sites. The median f/u was 3.3 (.1-19.8) months, and 11/46 (24%) were still alive at last analysis. The most common histology, RT prescription, and treatment site included non-small cell lung cancer (23/46, 50%), 30 Gy in 10 fractions (16/67, 24%), and central thorax/abdomen (26/67, 39%), respectively. 79% (53/67) of irradiated sites were treated with 3D-conformal technique and palliative dose-fractionation. Grade 3, 4, and 5 toxicities were experienced by 11, 1, and 2 patients, respectively. However all grade 4 and 5 toxicities were outside of the irradiated area and attributed to the NIVO alone, and only 4/11 (36%) of the grade 3 toxicities were attributed to the RT-NIVO. The irradiated site in these cases included the brain [2/10 (20%)] and central thorax/abdomen [2/19 (10.5%)], including one unexpected grade 3 pancreatitides following stereotactic body RT to the left adrenal gland. Conclusions: Concurrent RT-NIVO is generally well tolerated, though with potentially increased rates of severe toxicity when irradiating the lung, abdomen, or brain. Pending more definitive data, we recommend counseling patients on the potentially increased rates of side effects from combined immunotherapy and radiotherapy to these locations. Future prospective trials assessing fractionation and sequencing of RT with IT will help inform combined therapy recommendations.

Keywords: combined immunotherapy and radiation, immunotherapy, Nivolumab, toxicity of concurrent immunotherapy and radiation

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11728 Model of Cosserat Continuum Dispersion in a Half-Space with a Scatterer

Authors: Francisco Velez, Juan David Gomez

Abstract:

Dispersion effects on the Scattering for a semicircular canyon in a micropolar continuum are analyzed, by using a computational finite element scheme. The presence of microrotational waves and the dispersive SV waves affects the propagation of elastic waves. Here, a contrast with the classic model is presented, and the dependence with the micropolar parameters is studied.

Keywords: scattering, semicircular canyon, wave dispersion, micropolar medium, FEM modeling

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11727 Combustion Analysis of Suspended Sodium Droplet

Authors: T. Watanabe

Abstract:

Combustion analysis of suspended sodium droplet is performed by solving numerically the Navier-Stokes equations and the energy conservation equations. The combustion model consists of the pre-ignition and post-ignition models. The reaction rate for the pre-ignition model is based on the chemical kinetics, while that for the post-ignition model is based on the mass transfer rate of oxygen. The calculated droplet temperature is shown to be in good agreement with the existing experimental data. The temperature field in and around the droplet is obtained as well as the droplet shape variation, and the present numerical model is confirmed to be effective for the combustion analysis.

Keywords: analysis, combustion, droplet, sodium

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11726 A Constitutive Model for Time-Dependent Behavior of Clay

Authors: T. N. Mac, B. Shahbodaghkhan, N. Khalili

Abstract:

A new elastic-viscoplastic (EVP) constitutive model is proposed for the analysis of time-dependent behavior of clay. The proposed model is based on the bounding surface plasticity and the concept of viscoplastic consistency framework to establish continuous transition from plasticity to rate dependent viscoplasticity. Unlike the overstress based models, this model will meet the consistency condition in formulating the constitutive equation for EVP model. The procedure of deriving the constitutive relationship is also presented. Simulation results and comparisons with experimental data are then presented to demonstrate the performance of the model.

Keywords: bounding surface, consistency theory, constitutive model, viscosity

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11725 Investigation of the Morphology of SiO2 Nano-Particles Using Different Synthesis Techniques

Authors: E. Gandomkar, S. Sabbaghi

Abstract:

In this paper, the effects of variation synthesized methods on morphology and size of silica nanostructure via modifying sol-gel and precipitation method have been investigated. Meanwhile, resulting products have been characterized by particle size analyzer, scanning electron microscopy (SEM), X-ray Diffraction (XRD) and Fourier transform infrared (FT-IR) spectra. As result, the shape of SiO2 with sol-gel and precipitation methods was spherical but with modifying sol-gel method we have been had nanolayer structure.

Keywords: modified sol-gel, precipitation, nanolayer, Na2SiO3, nanoparticle

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11724 Cognitive Approach at the Epicenter of Creative Accounting in Cameroonian Companies: The Relevance of the Psycho-Sociological Approach and the Theory of Cognitive Dissonance

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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11723 Jurisdictional Federalism and Formal Federalism: Levels of Political Centralization on American and Brazilian Models

Authors: Henrique Rangel, Alexandre Fadel, Igor De Lazari, Bianca Neri, Carlos Bolonha

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This paper promotes a comparative analysis of American and Brazilian models of federalism assuming their levels of political centralization as main criterion. The central problem faced herein is the Brazilian approach of Unitarian regime. Although the hegemony of federative form after 1989, Brazil had a historical frame of political centralization that remains under the 1988 constitutional regime. Meanwhile, United States framed a federalism in which States absorb significant authorities. The hypothesis holds that the amount of alternative criteria of federalization – which can generate political centralization –, and the way they are upheld on judicial review, are crucial to understand the levels of political centralization achieved in each model. To test this hypothesis, the research is conducted by a methodology temporally delimited to 1994-2014 period. Three paradigmatic precedents of U.S. Supreme Court were selected: United States vs. Morrison (2000), on gender-motivated violence, Gonzales vs. Raich (2005), on medical use of marijuana, and United States vs. Lopez (1995), on firearm possession on scholar zones. These most relevant cases over federalism in the recent activity of Supreme Court indicates a determinant parameter of deliberation: the commerce clause. After observe the criterion used to permit or prohibit the political centralization in America, the Brazilian normative context is presented. In this sense, it is possible to identify the eventual legal treatment these controversies could receive in this Country. The decision-making reveals some deliberative parameters, which characterizes each federative model. At the end of research, the precedents of Rehnquist Court promote a broad revival of federalism debate, establishing the commerce clause as a secure criterion to uphold or not the necessity of centralization – even with decisions considered conservative. Otherwise, the Brazilian federalism solves them controversies upon in a formalist fashion, within numerous and comprehensive – sometimes casuistic too – normative devices, oriented to make an intense centralization. The aim of this work is indicate how jurisdictional federalism found in United States can preserve a consistent model with States robustly autonomous, while Brazil gives preference to normative mechanisms designed to starts from centralization.

Keywords: constitutional design, federalism, U.S. Supreme Court, legislative authority

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11722 A Case Study in Using the Can-Sized Satellite Platforms for Interdisciplinary Problem-Based Learning in Aeronautical and Electronic Engineering

Authors: Michael Johnson, Vincenzo Oliveri

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This work considers an interdisciplinary Problem-Based Learning (PBL) project developed by lecturers from the Aeronautical and Electronic and Computer Engineering departments at the University of Limerick. This “CANSAT” project utilises the CanSat can-sized satellite platform in order to allow students from aeronautical and electronic engineering to engage in a mixed format (online/face-to-face), interdisciplinary PBL assignment using a real-world platform and application. The project introduces students to the design, development, and construction of the CanSat system over the course of a single semester, enabling student(s) to apply their aeronautical and technical skills/capabilities to the realisation of a working CanSat system. In this case study, the CanSat kits are used to pivot the real-world, discipline-relevant PBL goal of designing, building, and testing the CanSat system with payload(s) from a traditional module-based setting to an online PBL setting. Feedback, impressions, benefits, and challenges identified through the semester are presented. Students found the project to be interesting and rewarding, with the interdisciplinary nature of the project appealing to them. Challenges and difficulties encountered are also addressed, with solutions developed between the students and facilitators to overcoming these discussed.

Keywords: problem-based learning, interdisciplinary, engineering, CanSATs

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11721 Algorithms Utilizing Wavelet to Solve Various Partial Differential Equations

Authors: K. P. Mredula, D. C. Vakaskar

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The article traces developments and evolution of various algorithms developed for solving partial differential equations using the significant combination of wavelet with few already explored solution procedures. The approach depicts a study over a decade of traces and remarks on the modifications in implementing multi-resolution of wavelet, finite difference approach, finite element method and finite volume in dealing with a variety of partial differential equations in the areas like plasma physics, astrophysics, shallow water models, modified Burger equations used in optical fibers, biology, fluid dynamics, chemical kinetics etc.

Keywords: multi-resolution, Haar Wavelet, partial differential equation, numerical methods

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11720 Experimental Simulations of Aerosol Effect to Landfalling Tropical Cyclones over Philippine Coast: Virtual Seeding Using WRF Model

Authors: Bhenjamin Jordan L. Ona

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Weather modification is an act of altering weather systems that catches interest on scientific studies. Cloud seeding is a common form of weather alteration. On the same principle, tropical cyclone mitigation experiment follows the methods of cloud seeding with intensity to account for. This study will present the effects of aerosol to tropical cyclone cloud microphysics and intensity. The framework of Weather Research and Forecasting (WRF) model incorporated with Thompson aerosol-aware scheme is the prime host to support the aerosol-cloud microphysics calculations of cloud condensation nuclei (CCN) ingested into the tropical cyclones before making landfall over the Philippine coast. The coupled microphysical and radiative effects of aerosols will be analyzed using numerical data conditions of Tropical Storm Ketsana (2009), Tropical Storm Washi (2011), and Typhoon Haiyan (2013) associated with varying CCN number concentrations per simulation per typhoon: clean maritime, polluted, and very polluted having 300 cm-3, 1000 cm-3, and 2000 cm-3 aerosol number initial concentrations, respectively. Aerosol species like sulphates, sea salts, black carbon, and organic carbon will be used as cloud nuclei and mineral dust as ice nuclei (IN). To make the study as realistic as possible, investigation during the biomass burning due to forest fire in Indonesia starting October 2015 as Typhoons Mujigae/Kabayan and Koppu/Lando had been seeded with aerosol emissions mainly comprises with black carbon and organic carbon, will be considered. Emission data that will be used is from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). The physical mechanism/s of intensification or deintensification of tropical cyclones will be determined after the seeding experiment analyses.

Keywords: aerosol, CCN, IN, tropical cylone

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11719 Spatial Analysis and Determinants of Number of Antenatal Health Care Visit Among Pregnant Women in Ethiopia: Application of Spatial Multilevel Count Regression Models

Authors: Muluwerk Ayele Derebe

Abstract:

Background: Antenatal care (ANC) is an essential element in the continuum of reproductive health care for preventing preventable pregnancy-related morbidity and mortality. Objective: The aim of this study is to assess the spatial pattern and predictors of ANC visits in Ethiopia. Method: This study was done using Ethiopian Demographic and Health Survey data of 2016 among 7,174 pregnant women aged 15-49 years which was a nationwide community-based cross-sectional survey. Spatial analysis was done using Getis-Ord Gi* statistics to identify hot and cold spot areas of ANC visits. Multilevel glmmTMB packages adjusted for spatial effects were used in R software. Spatial multilevel count regression was conducted to identify predictors of antenatal care visits for pregnant women, and proportional change in variance was done to uncover the effect of individual and community-level factors of ANC visits. Results: The distribution of ANC visits was spatially clustered Moran’s I = 0.271, p<.0.001, ICC = 0.497, p<0.001). The highest spatial outlier areas of ANC visit was found in Amhara (South Wollo, Weast Gojjam, North Shewa), Oromo (west Arsi and East Harariga), Tigray (Central Tigray) and Benishangul-Gumuz (Asosa and Metekel) regions. The data was found with excess zeros (34.6%) and over-dispersed. The expected ANC visit of pregnant women with pregnancy complications was higher at 0.7868 [ARR= 2.1964, 95% CI: 1.8605, 2.5928, p-value <0.0001] compared to pregnant women who had no pregnancy complications. The expected ANC visit of a pregnant woman who lived in a rural area was 1.2254 times higher [ARR=3.4057, 95% CI: 2.1462, 5.4041, p-value <0.0001] as compared to a pregnant woman who lived in an urban. The study found dissimilar clusters with a low number of zero counts for a mean number of ANC visits surrounded by clusters with a higher number of counts of an average number of ANC visits when other variables held constant. Conclusion: This study found that the number of ANC visits in Ethiopia had a spatial pattern associated with socioeconomic, demographic, and geographic risk factors. Spatial clustering of ANC visits exists in all regions of Ethiopia. The predictor age of the mother, religion, mother’s education, husband’s education, mother's occupation, husband's occupation, signs of pregnancy complication, wealth index and marital status had a strong association with the number of ANC visits by each individual. At the community level, place of residence, region, age of the mother, sex of the household head, signs of pregnancy complications and distance to health facility factors had a strong association with the number of ANC visits.

Keywords: Ethiopia, ANC, spatial, multilevel, zero inflated Poisson

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11718 The Influence of Ibuprofen, Diclofenac and Naproxen on Composition and Ultrastructural Characteristics of Atriplex patula and Spinacia oleracea

Authors: Ocsana Opris, Ildiko Lung, Maria L. Soran, Alexandra Ciorita, Lucian Copolovici

Abstract:

The effects assessment of environmental stress factors on both crop and wild plants of nutritional value are a very important research topic. Continuously worldwide consumption of drugs leads to significant environmental pollution, thus generating environmental stress. Understanding the effects of the important drugs on plant composition and ultrastructural modification is still limited, especially at environmentally relevant concentrations. The aim of the present work was to investigate the influence of three non-steroidal anti-inflammatory drugs (NSAIDs) on chlorophylls content, carotenoids content, total polyphenols content, antioxidant capacity, and ultrastructure of orache (Atriplex patula L.) and spinach (Spinacia oleracea L.). All green leafy vegetables selected for this study were grown in controlled conditions and treated with solutions of different concentrations (0.1‒1 mg L⁻¹) of diclofenac, ibuprofen, and naproxen. After eight weeks of exposure of the plants to NSAIDs, the chlorophylls and carotenoids content were analyzed by high-performance liquid chromatography coupled with photodiode array and mass spectrometer detectors, total polyphenols and antioxidant capacity by ultraviolet-visible spectroscopy. Also, the ultrastructural analyses of the vegetables were performed using transmission electron microscopy in order to assess the influence of the selected NSAIDs on cellular organisms, mainly photosynthetic organisms (chloroplasts), energy supply organisms (mitochondria) and nucleus as a cellular metabolism coordinator. In comparison with the control plants, decreases in the content of chlorophylls were observed in the case of the Atriplex patula L. plants treated with ibuprofen (11-34%) and naproxen (25-52%). Also, the chlorophylls content from Spinacia oleracea L. was affected, the lowest decrease (34%) being obtained in the case of the treatment with naproxen (1 mg L⁻¹). Diclofenac (1 mg L⁻¹) affected the total polyphenols content (a decrease of 45%) of Atriplex patula L. and ibuprofen (1 mg L⁻¹) affected the total polyphenols content (a decrease of 20%) of Spinacia oleracea L. The results obtained also indicate a moderate reduction of carotenoids and antioxidant capacity in the treated plants, in comparison with the controls. The investigations by transmission electron microscopy demonstrated that the green leafy vegetables were affected by the selected NSAIDs. Thus, this research contributes to a better understanding of the adverse effects of these drugs on studied plants. Important to mention is that the dietary intake of these drugs contaminated plants, plants with important nutritional value, may also presume a risk to human health, but currently little is known about the fate of the drugs in plants and their effect on or risk to the ecosystem.

Keywords: abiotic stress, green leafy vegetables, pigments content, ultra structure

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11717 Antihyperlipidemia Combination of Simvastatin and Herbal Drink (Conventional Drug Interaction Potential Study and Herbal As Prevention Adverse Effect on Combination Therapy Hyperlipidemia)

Authors: Gesti Prastiti, Maylina Adani, Yuyun darma A. N., M. Khilmi F., Yunita Wahyu Pratiwi

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Combination therapy may allow interaction on two drugs or more that can give adverse effects on patients. Simvastatin is a drug of antihyperlipidemia it can interact with drugs which work on cytochrome P450 CYP3A4 because it can interfere the performance of simvastatin. Flavonoid found in plants can inhibit the cytochrome P450 CYP3A4 if taken with simvastatin and can increase simvastatin levels in the body and increases the potential side effects of simvastatin such as myopati and rhabdomyolysis. Green tea leaves and mint are herbal medicine which has the effect of antihiperlipidemia. This study aims to determine the potential interaction of simvastatin with herbal drinks (green tea leaves and mint). This research method are experimental post-test only control design. Test subjects were divided into 5 groups: normal group, negative control group, simvastatin group, a combination of green tea group and the combination group mint leaves. The study was conducted over 32 days and total cholesterol levels were analyzed by enzymatic colorimetric test method. Results of this study is the obtainment of average value of total cholesterol in each group, the normal group (65.92 mg/dL), the negative control group the average total cholesterol test in the normal group was (69.86 mg/dL), simvastatin group (58.96 mg/dL), the combination of green tea group (58.96 mg/dL), and the combination of mint leaves (63.68 mg/dL). The conclusion is between simvastatin combination therapy with herbal drinks have the potential for pharmacodynamic interactions with a synergistic effect, antagonist, and a powerful additive, so the combination therapy are no more effective than a single administration of simvastatin therapy.

Keywords: hyperlipidemia, simvastatin, herbal drinks, green tea leaves, mint leaves, drug interactions

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11716 Fracture Toughness Characterizations of Single Edge Notch (SENB) Testing Using DIC System

Authors: Amr Mohamadien, Ali Imanpour, Sylvester Agbo, Nader Yoosef-Ghodsi, Samer Adeeb

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The fracture toughness resistance curve (e.g., J-R curve and crack tip opening displacement (CTOD) or δ-R curve) is important in facilitating strain-based design and integrity assessment of oil and gas pipelines. This paper aims to present laboratory experimental data to characterize the fracture behavior of pipeline steel. The influential parameters associated with the fracture of API 5L X52 pipeline steel, including different initial crack sizes, were experimentally investigated for a single notch edge bend (SENB). A total of 9 small-scale specimens with different crack length to specimen depth ratios were conducted and tested using single edge notch bending (SENB). ASTM E1820 and BS7448 provide testing procedures to construct the fracture resistance curve (Load-CTOD, CTOD-R, or J-R) from test results. However, these procedures are limited by standard specimens’ dimensions, displacement gauges, and calibration curves. To overcome these limitations, this paper presents the use of small-scale specimens and a 3D-digital image correlation (DIC) system to extract the parameters required for fracture toughness estimation. Fracture resistance curve parameters in terms of crack mouth open displacement (CMOD), crack tip opening displacement (CTOD), and crack growth length (∆a) were carried out from test results by utilizing the DIC system, and an improved regression fitting resistance function (CTOD Vs. crack growth), or (J-integral Vs. crack growth) that is dependent on a variety of initial crack sizes was constructed and presented. The obtained results were compared to the available results of the classical physical measurement techniques, and acceptable matchings were observed. Moreover, a case study was implemented to estimate the maximum strain value that initiates the stable crack growth. This might be of interest to developing more accurate strain-based damage models. The results of laboratory testing in this study offer a valuable database to develop and validate damage models that are able to predict crack propagation of pipeline steel, accounting for the influential parameters associated with fracture toughness.

Keywords: fracture toughness, crack propagation in pipeline steels, CTOD-R, strain-based damage model

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11715 Simple Model of Social Innovation Based on Entrepreneurship Incidence in Mexico

Authors: Vicente Espinola, Luis Torres, Christhian Gonzalez

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Entrepreneurship is a topic of current interest in Mexico and the World, which has been fostered through public policies with great impact on its generation. The strategies used in Mexico have not been successful, being motivational strategies aimed at the masses with the intention that someone in the process generates a venture. The strategies used for its development have been "picking of winners" favoring those who have already overcome the initial stages of undertaking without effective support. This situation shows a disarticulation that appears even more in social entrepreneurship; due to this, it is relevant to research on those elements that could develop them and thus integrate a model of entrepreneurship and social innovation for Mexico. Social entrepreneurship should be generating social innovation, which is translated into business models in order to make the benefits reach the population. These models are proposed putting the social impact before the economic impact, without forgetting its sustainability in the medium and long term. In this work, we present a simple model of innovation and social entrepreneurship for Guanajuato, Mexico. This algorithm was based on how social innovation could be generated in a systemic way for Mexico through different institutions that promote innovation. In this case, the technological parks of the state of Guanajuato were studied because these are considered one of the areas of Mexico where its main objectives are to make technology transfer to companies but overlooking the social sector and entrepreneurs. An experimental design of n = 60 was carried out with potential entrepreneurs to identify their perception of the social approach that the enterprises should have, the skills they consider required to create a venture, as well as their interest in generating ventures that solve social problems. This experiment had a 2K design, the value of k = 3 and the computational simulation was performed in R statistical language. A simple model of interconnected variables is proposed, which allows us to identify where it is necessary to increase efforts for the generation of social enterprises. The 96.67% of potential entrepreneurs expressed interest in ventures that solve social problems. In the analysis of the variables interaction, it was identified that the isolated development of entrepreneurial skills would only replicate the generation of traditional ventures. The variable of social approach presented positive interactions, which may influence the generation of social entrepreneurship if this variable was strengthened and permeated in the processes of training and development of entrepreneurs. In the future, it will be necessary to analyze the institutional actors that are present in the social entrepreneurship ecosystem, in order to analyze the interaction necessary to strengt the innovation and social entrepreneurship ecosystem.

Keywords: social innovation, model, entrepreneurship, technological parks

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11714 Synthetic Coumarin Derivatives and Their Anticancer Properties

Authors: Kabange Kasumbwe, Viresh Mohanlall, Bharti Odhav, Venu Narayanaswamy

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Coumarins are naturally occurring plant metabolites known for their pharmacological properties such as anticoagulant, antimicrobial, anticancer, antioxidant, anti-inflammatory and antiviral properties. The pharmacological and biochemical properties and curative applications of coumarins depend on the substitution around the coumarin core structure. In the present study, seven halogenated coumarins CMRN1-CMRN7 were synthesized and evaluated for their anticancer activity. The cytotoxicity potential of the test compounds was evaluated against UACC62 (Melanoma), MCF-7 (Breast cancer) and PBM (Peripheral Blood Mononuclear) cell lines using MTT assay keeping doxorubicin as standard drug. The apoptotic potential of the coumarin compounds was evaluated against UACC62 (Melanoma) cell by assessing their morphological changes, membrane change, mitochondria membrane potential; pro-apoptotic changes were investigated using the AnnexinV-PI staining, JC-1, caspase-3 enzyme kits respectively on flow cytometer. The synthetic coumarin has strongly suppressed the cell proliferation of UACC-62 (Melanoma) and MCF-7 (Breast) Cancer cells, the higher toxicity of these compounds against UACC-62 (Melanoma) and MCF-7 (Breast) were CMRN3, CMRN4, CMRN5, CMRN6. However, compounds CMRN1, CMRN2, and CMRN7 had no significant inhibitory effect. Furthermore the active compounds CMRN3, CMRN4, CMRN5, CMRN6 exerted antiproliferative effects through apoptosis induction against UACC-62 (Melanoma), suggesting their potential could be considered as attractive lead molecules in the future for the development of potential anticancer agents since one of the important criteria in the development of therapeutic drugs for cancer treatment is to have high selectivity and less or no side-effects on normal cells and these compounds had no inhibitory effect against the PBMC cells.

Keywords: coumarin, MTT, apoptosis, cytotoxicity

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11713 Amino Acid Derivatives as Green Corrosion Inhibitors for Mild Steel in 1M HCl: Electrochemical, Surface and Density Functional Theory Studies

Authors: Jiyaul Haque, Vandana Srivastava, M. A. Quraishi

Abstract:

The amino acids based corrosion inhibitors 2-(3-(carboxymethyl)-1H-imidazol-3-ium-1-yl) acetate (Z-1),2-(3-(1-carboxyethyl)-1H-imidazol-3-ium-1-yl) propanoate (Z-2) and 2-(3-(1-carboxy-2-phenylethyl)-1H-imidazol-3-ium-1-yl)-3- phenylpropanoate (Z-3) were synthesized by the reaction of amino acids, glyoxal and formaldehyde, and characterized by the FTIR and NMR spectroscopy. The corrosion inhibition performance of synthesized inhibitors was studied by electrochemical (EIS and PDP), surface and DFT methods. The results show, the studied Z-1, Z-2 and Z-3 are effective inhibitors, showed the maximum inhibition efficiency of 88.52 %, 89.48 and 96.08% at concentration 200ppm, respectively. The results of potentiodynamic polarization (PDP) study showed that Z-1 act as a cathodic inhibitor, while Z-2 and Z-3 act as mixed type inhibitors. The results of electrochemical impedance spectroscopy (EIS) studies showed that zwitterions inhibit the corrosion through adsorption mechanism. The adsorption of synthesized zwitterions on the mild steel surface was followed the Langmuir adsorption isotherm. The formation of zwitterions film on mild steel surface was confirmed by the scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). The quantum chemical parameters were used to study the reactivity of inhibitors and supported the experimental results. An inhibitor adsorption model is proposed.

Keywords: electrochemical impedance spectroscopy, green corrosion inhibitors, mild steel, SEM, quantum chemical calculation, zwitterions

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11712 Hybrid SVM/DBN Model for Arabic Isolated Words Recognition

Authors: Elyes Zarrouk, Yassine Benayed, Faiez Gargouri

Abstract:

This paper presents a new hybrid model for isolated Arabic words recognition. To do this, we apply Support Vectors Machine (SVM) as an estimator of posterior probabilities within the Dynamic Bayesian networks (DBN). This paper deals a comparative study between DBN and SVM/DBN systems for multi-dialect isolated Arabic words. Performance using SVM/DBN is found to exceed that of DBNs trained on an identical task, giving higher recognition accuracy for four different Arabic dialects. In fact, the average of recognition rates for the four dialects with SVM/DBN was 87.67% while 83.01% with DBN.

Keywords: dynamic Bayesian networks, hybrid models, supports vectors machine, Arabic isolated words

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11711 Breaking Sensitivity Barriers: Perovskite Based Gas Sensors With Dimethylacetamide-Dimethyl Sulfoxide Solvent Mixture Strategy

Authors: Endalamaw Ewnu Kassa, Ade Kurniawan, Ya-Fen Wu, Sajal Biring

Abstract:

Perovskite-based gas sensors represent a highly promising materials within the realm of gas sensing technology, with a particular focus on detecting ammonia (NH3) due to its potential hazards. Our work conducted thorough comparison of various solvents, including dimethylformamide (DMF), DMF-dimethyl sulfoxide (DMSO), dimethylacetamide (DMAC), and DMAC-DMSO, for the preparation of our perovskite solution (MAPbI3). Significantly, we achieved an exceptional response at 10 ppm of ammonia gas by employing a binary solvent mixture of DMAC-DMSO. In contrast to prior reports that relied on single solvents for MAPbI3 precursor preparation, our approach using mixed solvents demonstrated a marked improvement in gas sensing performance. We attained enhanced surface coverage, a reduction in pinhole occurrences, and precise control over grain size in our perovskite films through the careful selection and mixtures of appropriate solvents. This study shows a promising potential of employing binary and multi-solvent mixture strategies as a means to propel advancements in gas sensor technology, opening up new opportunities for practical applications in environmental monitoring and industrial safety.

Keywords: sensors, binary solvents, ammonia, sensitivity, grain size, pinholes, surface coverage

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11710 Individual and Organisational Outcomes of Psychosocial Hazard Exposures in Disaster and Emergency work: Qualitative Evidence from Ghana

Authors: Elias Kodjo Kekesi

Abstract:

This study seeks to investigate a critical but neglected area in disaster and emergency management in Ghana. It explores aspects of work within one of the safety-critical work environments that expose workers to psychological, social and physical harm. With much attention to crises’ survivors, deceased and their families, this research attempts to answer a key question: ‘What happens to the rescuer’? Emergency response is associated with immense and unprecedented pressure that puts responders’ physical, mental and social well-being at risk. Despite the negative psychological outcomes, scholars argue that being in a traumatic situation may trigger positive outcomes for some people. Thus, the study also focuses on the positive impact of working in a risky crisis environment. Additionally, people’s interpretation of negative experiences or exposure to adverse conditions differ owing to their personal resources which explains why some people may be negatively affected whiles others are positively impacted. To examine these complex nuances, an exploratory sequential mixed method design is adopted. This paper will highlight the findings of study one, which explores the underlying themes emerging from the Ghanaian disaster and emergency response environment regarding psychosocial hazard exposures and the corresponding outcomes.

Keywords: psychosocial hazards, organisational outcomes, qualitative research, Ghana

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11709 Corporate Governance Reforms in a Developing Economy: Making a Case for Upstream and Downstream Interventions

Authors: Franklin Nakpodia, Femi Olan

Abstract:

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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11708 Improving Academic Literacy in the Secondary History Classroom

Authors: Wilhelmina van den Berg

Abstract:

Through intentionally developing the Register Continuum and the Functional Model of Language in the secondary history classroom, teachers can effectively build a teaching and learning cycle geared towards literacy improvement and EAL differentiation. Developing an understanding of and engaging students in the field, tenor, and tone of written and spoken language, allows students to build the foundation for greater academic achievement due to integrated literacy skills in the history classroom. Building a variety of scaffolds during lessons within these models means students can improve their academic language and communication skills.

Keywords: academic language, EAL, functional model of language, international baccalaureate, literacy skills

Procedia PDF Downloads 51
11707 Development of Automatic Farm Manure Spreading Machine for Orchards

Authors: Barış Ozluoymak, Emin Guzel, Ahmet İnce

Abstract:

Since chemical fertilizers are used for meeting the deficiency of plant nutrients, its many harmful effects are not taken into consideration for the structure of the earth. These fertilizers are hampering the work of the organisms in the soil immediately after thrown to the ground. This interference is first started with a change of the soil pH and micro organismic balance is disrupted by reaction in the soil. Since there can be no fragmentation of plant residues, organic matter in the soil will be increasingly impoverished in the absence of micro organismic living. Biological activity reduction brings about a deterioration of the soil structure. If the chemical fertilization continues intensively, soils will get worse every year; plant growth will slow down and stop due to the intensity of chemical fertilizers, yield decline will be experienced and farmer will not receive an adequate return on his investment. In this research, a prototype of automatic farm manure spreading machine for orange orchards that not just manufactured in Turkey was designed, constructed, tested and eliminate the human drudgery involved in spreading of farm manure in the field. The machine comprised several components as a 5 m3 volume hopper, automatic controlled hydraulically driven chain conveyor device and side delivery conveyor belts. To spread the solid farm manure automatically, the machine was equipped with an electronic control system. The hopper and side delivery conveyor designs fitted between orange orchard tree row spacing. Test results showed that the control system has significant effects on reduction in the amount of unnecessary solid farm manure use and avoiding inefficient manual labor.

Keywords: automatic control system, conveyor belt application, orchard, solid farm manure

Procedia PDF Downloads 277
11706 The Effects on Abomasal Emtying Rate of Erythromycin and Bethanechol in Healthy, Premature and Diarrheic Calves

Authors: Sebnem Canikli Engin, Mutlu Sevinc, Hasan Guzelbektes

Abstract:

In this study, we aim to define the effects of erythromycin and bethanechol which are prokinetic agents, on the value of abomasal discharge in healthy, diarrhea and premature calves. In the work, 5 healty calves, 12 diarrheaic calves and 12 premature calves, amounting to a total of 29 calves. In healty calves work; the same 5 calves were used for controlled, erythromycin and bethanechol studies (there was a 48-hour waiting period between each work). In diarrheic calves work; 12 diarrheic calves were used during the study (4 of them for control group, 4 of them bethanechol group and last 4 calves erythromycin group). In premature calves works; 12 premature calves were used during the study (4 of them for control group, 4 of them bethanechol group and last 4 calves erythromycin group). 10 mg/kg IM dose of erythromycin were applied to each erythromycin group, 0,07 mg/kg IM dose of bethanechol were applied on bethanechol group. No drugs were applied to the control group and substitution milk was given to all calves. 50 mg/kg acetominophen and 25 gram/L glucose have been added into the substitution milk to evaluate the speed of gastrointestinal motility with the test results of absorptions of acetominophen and glucose. The blood samples have been taken before substitution milk application and 30, 60, 90, 120, 180, 240 and 300 minutes after substitution milk application. Respiratory rates and number of heartbeats were also recorded during the test time. No changes were observed in the number of heartbeats, respiratory rates and general conditions for all groups after drug application. It is observed that, the feces of some calves became slightly watery and viscous and premature calves generaly defecated after 180 minutes. When Cmax, Tmax and AUC values of acetaminophen and glucose are compared with control group’s after applying erythromycin on the calves in the premature group, we obtain higher Cmax (P<0,05), shorter Tmax and greather AUC (P>0,05) values. In conclusion, according to clinical and laboratory findings, it may be stated that the application of 10 mg/kg doze of erythromycin IM has provided faster abomazal emptying in premature calves.

Keywords: abomazal emptying, bethanechol, calf, erythromycin

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11705 On the Inequality between Queue Length and Virtual Waiting Time in Open Queueing Networks under Conditions of Heavy Traffic

Authors: Saulius Minkevicius, Edvinas Greicius

Abstract:

The paper is devoted to the analysis of queueing systems in the context of the network and communications theory. We investigate the inequality in an open queueing network and its applications to the theorems in heavy traffic conditions (fluid approximation, functional limit theorem, and law of the iterated logarithm) for a queue of customers in an open queueing network.

Keywords: fluid approximation, heavy traffic, models of information systems, open queueing network, queue length of customers, queueing theory

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11704 A Review of Existing Turnover Intention Theories

Authors: Pauline E. Ngo-Henha

Abstract:

Existing turnover intention theories are reviewed in this paper. This review was conducted with the help of the search keyword “turnover intention theories” in Google Scholar during the month of July 2017. These theories include: The Theory of Organizational Equilibrium (TOE), Social Exchange Theory, Job Embeddedness Theory, Herzberg’s Two-Factor Theory, the Resource-Based View, Equity Theory, Human Capital Theory, and the Expectancy Theory. One of the limitations of this review paper is that data were only collected from Google Scholar where many papers were sometimes not freely accessible. However, this paper attempts to contribute to the research in clarifying the distinction between theories and models in the context of turnover intention.

Keywords: Literature Review, Theory, Turnover, Turnover intention

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11703 “BUM629” Special Hybrid Reinforcement Materials for Mega Structures

Authors: Gautam, Arjun, V. R. Sharma

Abstract:

In the civil construction steel and concrete plays a different role but the same purposes dealing with the design of structures that support or resist loads. Concrete has been used in construction since long time from now. Being brittle and weak in tension, concrete is always reinforced with steel bars for the purposes in beams and columns etc. The paper deals with idea of special designed 3D materials which we named as “BUM629” to be placed/anchored in the structural member and mixed with concrete later on, so as to resist the developments of cracks due to shear failure , buckling,tension and compressive load in concrete. It had cutting edge technology through Draft, Analysis and Design the “BUM629”. The results show that “BUM629” has the great results in Mechanical application. Its material properties are design according to the need of structure; we apply the material such as Mild Steel and Magnesium Alloy. “BUM629” are divided into two parts one is applied at the middle section of concrete member where bending movements are maximum and the second part is laying parallel to vertical bars near clear cover, so we design this material and apply in Reinforcement of Civil Structures. “BUM629” is analysis and design for use in the mega structures like skyscrapers, dams and bridges.

Keywords: BUM629, magnesium alloy, cutting edge technology, mechanical application, draft, analysis and design, mega structures

Procedia PDF Downloads 372