Search results for: linear dynamical boundary condition
540 Work-Family Conflict and Family and Job Resources among Women: The Role of Negotiation
Authors: Noa Nelson, Meitar Moshe, Dana Cohen
Abstract:
Work-family conflict (WFC) is a significant source of stress for contemporary employees, with research indicating its heightened severity for women. The conservation of resources theory argues that individuals experience stress when their resources fall short of demands, and attempt to reach balance by obtaining resources. Presumably then, to achieve work-family balance women would need to negotiate for resources such as spouse support, employer support and work flexibility. The current research tested the hypotheses that competent negotiation at home and at work associated with increased family and job resources and with decreased WFC, as well as with higher work, marital and life satisfaction. In the first study, 113 employed mothers, married or cohabiting, reported to what extent they conducted satisfactory negotiation with spouse over division of housework, and their actual housework load compared to spouse. They answered a WFC questionnaire, measuring how much work interferes with family (WIF) and how much family interferes with work (FIW), and finally, measurements of satisfaction. In the second study, 94 employed mothers, married or cohabiting reported to what extent they conducted satisfactory negotiation with their boss over balancing work demands with family needs. They reported the levels of three job resources: flexibility, control and family-friendly organizational culture. Finally, they answered the same WFC and satisfaction measurements from study 1. Statistical analyses –t-tests, correlations, and hierarchical linear regressions- showed that in both studies, women reported higher WIF than FIW. Negotiations associated with increased resources: support from spouse, work flexibility and control and a family-friendly culture; negotiation with spouse associated also with satisfaction measurements. However, negotiations or resources (except family-friendly culture) did not associate with reduced conflict. The studies demonstrate the role of negotiation in obtaining family and job resources. Causation cannot be determined, but the fact is that employed mothers who enjoyed more support (at both home and work), flexibility and control, were more likely to keep active interactions to increase them. This finding has theoretical and practical implications, especially in view of research on female avoidance of negotiation. It is intriguing that negotiations and resources generally did not associate with reduced WFC. This finding might reflect the severity of the conflict, especially of work interfering with family, which characterizes many contemporary jobs. It might also suggest that employed mothers have high expectations from themselves, and even under supportive circumstances, experience the challenge of balancing two significant and demanding roles. The research contributes to the fields of negotiation, gender, and work-life balance. It calls for further studies, to test its model in additional populations and validate the role employees have in actively negotiating for the balance that they need. It also calls for further research to understand the contributions of job and family resources to reducing work-family conflict, and the circumstances under which they contribute.Keywords: sork-family conflict, work-life balance, negotiation, gender, job resources, family resources
Procedia PDF Downloads 226539 Neuroprotection against N-Methyl-D-Aspartate-Induced Optic Nerve and Retinal Degeneration Changes by Philanthotoxin-343 to Alleviate Visual Impairments Involve Reduced Nitrosative Stress
Authors: Izuddin Fahmy Abu, Mohamad Haiqal Nizar Mohamad, Muhammad Fattah Fazel, Renu Agarwal, Igor Iezhitsa, Nor Salmah Bakar, Henrik Franzyk, Ian Mellor
Abstract:
Glaucoma is the global leading cause of irreversible blindness. Currently, the available treatment strategy only involves lowering intraocular pressure (IOP); however, the condition often progresses despite lowered or normal IOP in some patients. N-methyl-D-aspartate receptor (NMDAR) excitotoxicity often occurs in neurodegeneration-related glaucoma; thus it is a relevant target to develop a therapy based on neuroprotection approach. This study investigated the effects of Philanthotoxin-343 (PhTX-343), an NMDAR antagonist, on the neuroprotection of NMDA-induced glaucoma to alleviate visual impairments. Male Sprague-Dawley rats were equally divided: Groups 1 (control) and 2 (glaucoma) were intravitreally injected with phosphate buffer saline (PBS) and NMDA (160nM), respectively, while group 3 was pre-treated with PhTX-343 (160nM) 24 hours prior to NMDA injection. Seven days post-treatments, rats were subjected to visual behavior assessments and subsequently euthanized to harvest their retina and optic nerve tissues for histological analysis and determination of nitrosative stress level using 3-nitrotyrosine ELISA. Visual behavior assessments via open field, object, and color recognition tests demonstrated poor visual performance in glaucoma rats indicated by high exploratory behavior. PhTX-343 pre-treatment appeared to preserve visual abilities as all test results were significantly improved (p < 0.05). H&E staining of the retina showed a marked reduction of ganglion cell layer thickness in the glaucoma group; in contrast, PhTX-343 significantly increased the number by 1.28-folds (p < 0.05). PhTX-343 also increased the number of cell nuclei/100μm2 within inner retina by 1.82-folds compared to the glaucoma group (p < 0.05). Toluidine blue staining of optic nerve tissues showed that PhTX-343 reduced the degeneration changes compared to the glaucoma group which exhibited vacuolation overall sections. PhTX-343 also decreased retinal 3- nitrotyrosine concentration by 1.74-folds compared to the glaucoma group (p < 0.05). All results in PhTX-343 group were comparable to control (p > 0.05). We conclude that PhTX-343 protects against NMDA-induced changes and visual impairments in the rat model by reducing nitrosative stress levels.Keywords: excitotoxicity, glaucoma, nitrosative stress , NMDA receptor , N-methyl-D-aspartate , philanthotoxin, visual behaviour
Procedia PDF Downloads 137538 E-Business Role in the Development of the Economy of Sultanate of Oman
Authors: Mairaj Salim, Asma Zaheer
Abstract:
Oman has accomplished as much or more than its fellow Gulf monarchies, despite starting from scratch considerably later, having less oil income to utilize, dealing with a larger and more rugged geography, and resolving a bitter civil war along the way. Of course, Oman's progress in the past 30-plus years has not been without problems and missteps, but the balance is squarely on the positive side of the ledger. Oil has been the driving force of the Omani economy since Oman began commercial production in 1967. The oil industry supports the country’s high standard of living and is primarily responsible for its modern and expansive infrastructure, including electrical utilities, telephone services, roads, public education and medical services. In addition to extensive oil reserves, Oman also has substantial natural gas reserves, which are expected to play a leading role in the Omani economy in the Twenty-first Century. To reduce the country’s dependence on oil revenues, the government is restructuring the economy by directing investment to non-oil activities. Since the 21st century IT has changed the performing tasks. To manage the affairs for the benefits of organizations and economy, the Omani government has adopted E-Business technologies for the development. E-Business is important because it allows • Transformation of old economy relationships (vertical/linear relationships) to new economy relationships characterized by end-to-end relationship management solutions (integrated or extended relationships) • Facilitation and organization of networks, small firms depend on ‘partner’ firms for supplies and product distribution to meet customer demands • SMEs to outsource back-end process or cost centers enabling the SME to focus on their core competence • ICT to connect, manage and integrate processes internally and externally • SMEs to join networks and enter new markets, through shortened supply chains to increase market share, customers and suppliers • SMEs to take up the benefits of e-business to reduce costs, increase customer satisfaction, improve client referral and attract quality partners • New business models of collaboration for SMEs to increase their skill base • SMEs to enter virtual trading arena and increase their market reach A national strategy for the advancement of information and communication technology (ICT) has been worked out, mainly to introduce e-government, e-commerce, and a digital society. An information technology complex KOM (Knowledge Oasis Muscat) had been established, consisting of section for information technology, incubator services, a shopping center of technology software and hardware, ICT colleges, E-Government services and other relevant services. So, all these efforts play a vital role in the development of Oman economy.Keywords: ICT, ITA, CRM, SCM, ERP, KOM, SMEs, e-commerce and e-business
Procedia PDF Downloads 251537 Open Joint Surgery for Temporomandibular Joint Internal Derangement: Wilkes Stages III-V
Authors: T. N. Goh, M. Hashmi, O. Hussain
Abstract:
Temporomandibular joint (TMJ) dysfunction (TMD) is a condition that may affect patients via restricted mouth opening, significant pain during normal functioning, and/or reproducible joint noise. TMD includes myofascial pain, TMJ functional derangements (internal derangement, dislocation), and TMJ degenerative/inflammatory joint disease. Internal derangement (ID) is the most common cause of TMD-related clicking and locking. These patients are managed in a stepwise approach, from patient education (homecare advice and analgesia), splint therapy, physiotherapy, botulinum toxin treatment, to arthrocentesis. Arthrotomy is offered when the aforementioned treatment options fail to alleviate symptoms and improve quality of life. The aim of this prospective study was to review the outcomes of jaw joint open surgery in TMD patients. Patients who presented from 2015-2022 at the Oral and Maxillofacial Surgery Department in the Doncaster NHS Foundation Trust, UK, with a Wilkes classification of III -V were included. These patients underwent either i) discopexy with bone-anchoring suture (9); ii) intrapositional temporalis flap (ITF) with bone-anchoring suture (3); iii) eminoplasty and discopexy with suturing to the capsule (3); iii) discectomy + ITF with bone-anchoring suture (1); iv) discoplasty + bone-anchoring suture (1); v) ITF (1). Maximum incisal opening (MIO) was assessed pre-operatively and at each follow-up. Pain score, determined via the visual analogue scale (VAS, with 0 being no pain and 10 being the worst pain), was also recorded. A total of 18 eligible patients were identified with a mean age of 45 (range 22 - 79), of which 16 were female. The patients were scored by Wilkes Classification as III (14), IV (1), or V (4). Twelve patients had anterior disc displacement without reduction (66%) and six had degenerative/arthritic changes (33%) to the TMJ. The open joint procedure resulted in an increase in MIO and reduction in pain VAS and for the majority of patients, across all Wilkes Classifications. Pre-procedural MIO was 22.9 ± 7.4 mm and VAS was 7.8 ± 1.5. At three months post-procedure there was an increase in MIO to 34.4 ± 10.4 mm (p < 0.01) and a decrease in the VAS to 1.5 ± 2.9 (p < 0.01). Three patients were lost to follow-up prior to six months. Six were discharged at six month review and five patients were discharged at 12 months review as they were asymptomatic with good mouth opening. Four patients are still attending for annual botulinum toxin treatment. Two patients (Wilkes III and V) subsequently underwent TMJ replacement (11%). One of these patients (Wilkes III) had improvement initially to MIO of 40 mm, but subsequently relapsed to less than 20 mm due to lack of compliance with jaw rehabilitation device post-operatively. Clinical improvements in 89% of patients within the study group were found, with a return to near normal MIO range and reduced pain score. Intraoperatively, the operator found bone-anchoring suture used for discopexy/discoplasty more secure than the soft tissue anchoring suturing technique.Keywords: bone anchoring suture, open temporomandibular joint surgery, temporomandibular joint, temporomandibular joint dysfunction
Procedia PDF Downloads 105536 High Efficiency Double-Band Printed Rectenna Model for Energy Harvesting
Authors: Rakelane A. Mendes, Sandro T. M. Goncalves, Raphaella L. R. Silva
Abstract:
The concepts of energy harvesting and wireless energy transfer have been widely discussed in recent times. There are some ways to create autonomous systems for collecting ambient energy, such as solar, vibratory, thermal, electromagnetic, radiofrequency (RF), among others. In the case of the RF it is possible to collect up to 100 μW / cm². To collect and/or transfer energy in RF systems, a device called rectenna is used, which is defined by the junction of an antenna and a rectifier circuit. The rectenna presented in this work is resonant at the frequencies of 1.8 GHz and 2.45 GHz. Frequencies at 1.8 GHz band are e part of the GSM / LTE band. The GSM (Global System for Mobile Communication) is a frequency band of mobile telephony, it is also called second generation mobile networks (2G), it came to standardize mobile telephony in the world and was originally developed for voice traffic. LTE (Long Term Evolution) or fourth generation (4G) has emerged to meet the demand for wireless access to services such as Internet access, online games, VoIP and video conferencing. The 2.45 GHz frequency is part of the ISM (Instrumentation, Scientific and Medical) frequency band, this band is internationally reserved for industrial, scientific and medical development with no need for licensing, and its only restrictions are related to maximum power transfer and bandwidth, which must be kept within certain limits (in Brazil the bandwidth is 2.4 - 2.4835 GHz). The rectenna presented in this work was designed to present efficiency above 50% for an input power of -15 dBm. It is known that for wireless energy capture systems the signal power is very low and varies greatly, for this reason this ultra-low input power was chosen. The Rectenna was built using the low cost FR4 (Flame Resistant) substrate, the antenna selected is a microfita antenna, consisting of a Meandered dipole, and this one was optimized using the software CST Studio. This antenna has high efficiency, high gain and high directivity. Gain is the quality of an antenna in capturing more or less efficiently the signals transmitted by another antenna and/or station. Directivity is the quality that an antenna has to better capture energy in a certain direction. The rectifier circuit used has series topology and was optimized using Keysight's ADS software. The rectifier circuit is the most complex part of the rectenna, since it includes the diode, which is a non-linear component. The chosen diode is the Schottky diode SMS 7630, this presents low barrier voltage (between 135-240 mV) and a wider band compared to other types of diodes, and these attributes make it perfect for this type of application. In the rectifier circuit are also used inductor and capacitor, these are part of the input and output filters of the rectifier circuit. The inductor has the function of decreasing the dispersion effect on the efficiency of the rectifier circuit. The capacitor has the function of eliminating the AC component of the rectifier circuit and making the signal undulating.Keywords: dipole antenna, double-band, high efficiency, rectenna
Procedia PDF Downloads 124535 Economic Decision Making under Cognitive Load: The Role of Numeracy and Financial Literacy
Authors: Vânia Costa, Nuno De Sá Teixeira, Ana C. Santos, Eduardo Santos
Abstract:
Financial literacy and numeracy have been regarded as paramount for rational household decision making in the increasing complexity of financial markets. However, financial decisions are often made under sub-optimal circumstances, including cognitive overload. The present study aims to clarify how financial literacy and numeracy, taken as relevant expert knowledge for financial decision-making, modulate possible effects of cognitive load. Participants were required to perform a choice between a sure loss or a gambling pertaining a financial investment, either with or without a competing memory task. Two experiments were conducted varying only the content of the competing task. In the first, the financial choice task was made while maintaining on working memory a list of five random letters. In the second, cognitive load was based upon the retention of six random digits. In both experiments, one of the items in the list had to be recalled given its serial position. Outcomes of the first experiment revealed no significant main effect or interactions involving cognitive load manipulation and numeracy and financial literacy skills, strongly suggesting that retaining a list of random letters did not interfere with the cognitive abilities required for financial decision making. Conversely, and in the second experiment, a significant interaction between the competing mnesic task and level of financial literacy (but not numeracy) was found for the frequency of choice of a gambling option. Overall, and in the control condition, both participants with high financial literacy and high numeracy were more prone to choose the gambling option. However, and when under cognitive load, participants with high financial literacy were as likely as their illiterate counterparts to choose the gambling option. This outcome is interpreted as evidence that financial literacy prevents intuitive risk-aversion reasoning only under highly favourable conditions, as is the case when no other task is competing for cognitive resources. In contrast, participants with higher levels of numeracy were consistently more prone to choose the gambling option in both experimental conditions. These results are discussed in the light of the opposition between classical dual-process theories and fuzzy-trace theories for intuitive decision making, suggesting that while some instances of expertise (as numeracy) are prone to support easily accessible gist representations, other expert skills (as financial literacy) depend upon deliberative processes. It is furthermore suggested that this dissociation between types of expert knowledge might depend on the degree to which they are generalizable across disparate settings. Finally, applied implications of the present study are discussed with a focus on how it informs financial regulators and the importance and limits of promoting financial literacy and general numeracy.Keywords: decision making, cognitive load, financial literacy, numeracy
Procedia PDF Downloads 183534 Statistical Comparison of Ensemble Based Storm Surge Forecasting Models
Authors: Amin Salighehdar, Ziwen Ye, Mingzhe Liu, Ionut Florescu, Alan F. Blumberg
Abstract:
Storm surge is an abnormal water level caused by a storm. Accurate prediction of a storm surge is a challenging problem. Researchers developed various ensemble modeling techniques to combine several individual forecasts to produce an overall presumably better forecast. There exist some simple ensemble modeling techniques in literature. For instance, Model Output Statistics (MOS), and running mean-bias removal are widely used techniques in storm surge prediction domain. However, these methods have some drawbacks. For instance, MOS is based on multiple linear regression and it needs a long period of training data. To overcome the shortcomings of these simple methods, researchers propose some advanced methods. For instance, ENSURF (Ensemble SURge Forecast) is a multi-model application for sea level forecast. This application creates a better forecast of sea level using a combination of several instances of the Bayesian Model Averaging (BMA). An ensemble dressing method is based on identifying best member forecast and using it for prediction. Our contribution in this paper can be summarized as follows. First, we investigate whether the ensemble models perform better than any single forecast. Therefore, we need to identify the single best forecast. We present a methodology based on a simple Bayesian selection method to select the best single forecast. Second, we present several new and simple ways to construct ensemble models. We use correlation and standard deviation as weights in combining different forecast models. Third, we use these ensembles and compare with several existing models in literature to forecast storm surge level. We then investigate whether developing a complex ensemble model is indeed needed. To achieve this goal, we use a simple average (one of the simplest and widely used ensemble model) as benchmark. Predicting the peak level of Surge during a storm as well as the precise time at which this peak level takes place is crucial, thus we develop a statistical platform to compare the performance of various ensemble methods. This statistical analysis is based on root mean square error of the ensemble forecast during the testing period and on the magnitude and timing of the forecasted peak surge compared to the actual time and peak. In this work, we analyze four hurricanes: hurricanes Irene and Lee in 2011, hurricane Sandy in 2012, and hurricane Joaquin in 2015. Since hurricane Irene developed at the end of August 2011 and hurricane Lee started just after Irene at the beginning of September 2011, in this study we consider them as a single contiguous hurricane event. The data set used for this study is generated by the New York Harbor Observing and Prediction System (NYHOPS). We find that even the simplest possible way of creating an ensemble produces results superior to any single forecast. We also show that the ensemble models we propose generally have better performance compared to the simple average ensemble technique.Keywords: Bayesian learning, ensemble model, statistical analysis, storm surge prediction
Procedia PDF Downloads 309533 Kawasaki Disease in a Two Months Kuwaiti Girl: A Case Report and Literature Review.
Authors: Hanan Bin Nakhi, Asaad M. Albadrawi, Maged Al Shahat, Entesar Mandani
Abstract:
Background: Kawasaki disease (KD) is one of the most common vasculitis of childhood. It is considered the leading cause of acquired heart disease in children. The peak age of occurrence is 6 to 24 months, with 80% of affected children being less than 5 years old. There are only a few reports of KD in infants younger than 6 months. Infants had a higher incidence of atypical KD and of coronary artery complications. This case report from Kuwait will reinforce considering atypical KD in case of sepsis like condition with negative cultures and unresponding to systemic antibiotics. Early diagnosis allows early treatment with intravenous immune globulin (IVIG) and so decreases the incidence of cardiac aneurysm. Case Report: A 2 month old female infant, product of full term normal delivery to consanguineous parents, presented with fever and poor feeding. She was admitted and treated as urinary tract infection as her urine routine revealed pyurea. The baby continued to have persistent fever and hypoactivity inspite of using intravenous antibiotics. Latter, she developed non purulent conjunctivitis, skin mottling, oedema of the face / lower limb and was treated in intensive care unit as a case of septic shock. In spite of her partial general improvement, she continued to look unwell, hypoactive and had persistent fever. Septic work up, metabolic, and immunologic screen were negative. KD was suspected when the baby developed polymorphic erythematous rash and noticed to have peeling of skin at perianal area and periangular area of the fingers of the hand and feet. IVIG was given in dose of 2 gm/kg/day in single dose and aspirin 100 mg/kg/day in four divided doses. The girl showed marked clinical improvement. The fever subsided dramatically and the level acute phase reactant markedly decreased but the platelets count increased to 1600000/mm3. Echo cardiography showed mild dilatation of mid right coronary artery. Aspirin was continued in a dose of 5 mg/kg/d till repeating cardiac echo. Conclusion: A high index of suspicion of KD must be maintained in young infants with prolonged unexplained fever. Accepted criteria should be less restrictive to allow early diagnosis of a typical KD in infants less than 6 months of age. Timely appropriate treatment with IVIG is essential to avoid severe coronary sequels.Keywords: Kawasaki disease, atypical Kawasaki disease, infantile Kawasaki disease, hypo activity
Procedia PDF Downloads 319532 Muscle and Cerebral Regional Oxygenation in Preterm Infants with Shock Using Near-Infrared Spectroscopy
Authors: Virany Diana, Martono Tri Utomo, Risa Etika
Abstract:
Background: Shock is one severe condition that can be a major cause of morbidity and mortality in the Neonatal Intensive Care Unit. Preterm infants are very susceptible to shock caused by many complications such as asphyxia, patent ductus arteriosus, intra ventricle haemorrhage, necrotizing enterocolitis, persistent pulmonal hypertension of the newborn, and septicaemia. Limited hemodynamic monitoring for early detection of shock causes delayed intervention and comprises the outcomes. Clinical parameters still used in neonatal shock detection, such as Capillary Refill Time, heart rate, cold extremity, and urine production. Blood pressure is most frequently used to evaluate preterm's circulation, but hypotension indicates uncompensated shock. Near-infrared spectroscopy (NIRS) is known as a noninvasive tool for monitoring and detecting the state of inadequate tissue perfusion. Muscle oxygen saturation shows decreased cardiac output earlier than systemic parameters of tissue oxygenation when cerebral regional oxygen saturation is still stabilized by autoregulation. However, to our best knowledge, until now, no study has analyzed the decrease of muscle oxygen regional saturation (mRSO₂) and the ratio of muscle and cerebral oxygen regional saturation (mRSO₂/cRSO₂) by NIRS in preterm with shock. Purpose: The purpose of this study is to analyze the decrease of mRSO₂ and ratio of muscle to cerebral oxygen regional saturation (mRSO₂/cRSO₂) by NIRS in preterm with shock. Patients and Methods: This cross-sectional study was conducted on preterm infants with 28-34 weeks gestational age, admitted to the NICU of Dr. Soetomo Hospital from November to January 2022. Patients were classified into two groups: shock and non-shock. The diagnosis of shock is based on clinical criteria (tachycardia, prolonged CRT, cold extremity, decreased urine production, and MAP Blood Pressure less than GA in weeks). Measurement of mRSO₂ and cRSO₂ by NIRS was performed by the doctor in charge when the patient came to NICU. Results: We enrolled 40 preterm infants. The initial conventional hemodynamic parameter as the basic diagnosis of shock showed significant differences in all variables. Preterm with shock had higher mean HR (186.45±1.5), lower MAP (29.8±2.1), and lower SBP (45.1±4.28) than non-shock children, and most had a prolonged CRT. The patients’ outcome was not a significant difference between shock and non-shock patients. The mean mRSO₂ in the shock and non-shock groups were 33,65 ± 11,32 vs. 69,15 ± 3,96 (p=0.001), and the mean ratio mRSO₂/cRSO₂ 0,45 ± 0,12 vs. 0,84 ± 0,43 (p=0,001), were significantly different. The mean cRSO₂ in the shock and non-shock groups were 71,60 ± 4,90 vs. 81,85 ± 7,85 (p 0.082), not significantly different. Conclusion: The decrease of mRSO₂ and ratio of mRSO₂/cRSO₂ can differentiate between shock and non-shock in the preterm infant when cRSO₂ is still normal.Keywords: preterm infant, regional muscle oxygen saturation, regional cerebral oxygen saturation, NIRS, shock
Procedia PDF Downloads 91531 Predictors of Sexually Transmitted Infection of Korean Adolescent Females: Analysis of Pooled Data from Korean Nationwide Survey
Authors: Jaeyoung Lee, Minji Je
Abstract:
Objectives: In adolescence, adolescents are curious about sex, but sexual experience before becoming an adult can cause the risk of high probability of sexually transmitted infection. Therefore, it is very important to prevent sexually transmitted infections so that adolescents can grow in healthy and upright way. Adolescent females, especially, have sexual behavior distinguished from that of male adolescents. Protecting female adolescents’ reproductive health is even more important since it is directly related to the childbirth of the next generation. This study, thus, investigated the predictors of sexually transmitted infection in adolescent females with sexual experiences based on the National Health Statistics in Korea. Methods: This study was conducted based on the National Health Statistics in Korea. The 11th Korea Youth Behavior Web-based Survey in 2016 was conducted in the type of anonymous self-reported survey in order to find out the health behavior of adolescents. The target recruitment group was middle and high school students nationwide as of April 2016, and 65,528 students from a total of 800 middle and high schools participated. The study was conducted in 537 female high school students (Grades 10–12) among them. The collected data were analyzed as complex sampling design using SPSS statistics 22. The strata, cluster, weight, and finite population correction provided by Korea Center for Disease Control & Prevention (KCDC) were reflected to constitute complex sample design files, which were used in the statistical analysis. The analysis methods included Rao-Scott chi-square test, complex samples general linear model, and complex samples multiple logistic regression analysis. Results: Out of 537 female adolescents, 11.9% (53 adolescents) had experiences of venereal infection. The predictors for venereal infection of the subjects were ‘age at first intercourse’ and ‘sexual intercourse after drinking’. The sexually transmitted infection of the subjects was decreased by 0.31 times (p=.006, 95%CI=0.13-0.71) for middle school students and 0.13 times (p<.001, 95%CI=0.05-0.32) for high school students whereas the age of the first sexual experience was under elementary school age. In addition, the sexually transmitted infection of the subjects was 3.54 times (p < .001, 95%CI=1.76-7.14) increased when they have experience of sexual relation after drinking alcohol, compared to those without the experience of sexual relation after drinking alcohol. Conclusions: The female adolescents had high probability of sexually transmitted infection if their age for the first sexual experience was low. Therefore, the female adolescents who start sexual experience earlier shall have practical sex education appropriate for their developmental stage. In addition, since the sexually transmitted infection increases, if they have sexual relations after drinking alcohol, the consideration for prevention of alcohol use or intervention of sex education shall be required. When health education intervention is conducted for health promotion for female adolescents in the future, it is necessary to reflect the result of this study.Keywords: adolescent, coitus, female, sexually transmitted diseases
Procedia PDF Downloads 192530 A Comparison of Methods for Estimating Dichotomous Treatment Effects: A Simulation Study
Authors: Jacqueline Y. Thompson, Sam Watson, Lee Middleton, Karla Hemming
Abstract:
Introduction: The odds ratio (estimated via logistic regression) is a well-established and common approach for estimating covariate-adjusted binary treatment effects when comparing a treatment and control group with dichotomous outcomes. Its popularity is primarily because of its stability and robustness to model misspecification. However, the situation is different for the relative risk and risk difference, which are arguably easier to interpret and better suited to specific designs such as non-inferiority studies. So far, there is no equivalent, widely acceptable approach to estimate an adjusted relative risk and risk difference when conducting clinical trials. This is partly due to the lack of a comprehensive evaluation of available candidate methods. Methods/Approach: A simulation study is designed to evaluate the performance of relevant candidate methods to estimate relative risks to represent conditional and marginal estimation approaches. We consider the log-binomial, generalised linear models (GLM) with iteratively weighted least-squares (IWLS) and model-based standard errors (SE); log-binomial GLM with convex optimisation and model-based SEs; log-binomial GLM with convex optimisation and permutation tests; modified-Poisson GLM IWLS and robust SEs; log-binomial generalised estimation equations (GEE) and robust SEs; marginal standardisation and delta method SEs; and marginal standardisation and permutation test SEs. Independent and identically distributed datasets are simulated from a randomised controlled trial to evaluate these candidate methods. Simulations are replicated 10000 times for each scenario across all possible combinations of sample sizes (200, 1000, and 5000), outcomes (10%, 50%, and 80%), and covariates (ranging from -0.05 to 0.7) representing weak, moderate or strong relationships. Treatment effects (ranging from 0, -0.5, 1; on the log-scale) will consider null (H0) and alternative (H1) hypotheses to evaluate coverage and power in realistic scenarios. Performance measures (bias, mean square error (MSE), relative efficiency, and convergence rates) are evaluated across scenarios covering a range of sample sizes, event rates, covariate prognostic strength, and model misspecifications. Potential Results, Relevance & Impact: There are several methods for estimating unadjusted and adjusted relative risks. However, it is unclear which method(s) is the most efficient, preserves type-I error rate, is robust to model misspecification, or is the most powerful when adjusting for non-prognostic and prognostic covariates. GEE estimations may be biased when the outcome distributions are not from marginal binary data. Also, it seems that marginal standardisation and convex optimisation may perform better than GLM IWLS log-binomial.Keywords: binary outcomes, statistical methods, clinical trials, simulation study
Procedia PDF Downloads 115529 Eggshell Waste Bioprocessing for Sustainable Acid Phosphatase Production and Minimizing Environmental Hazards
Authors: Soad Abubakr Abdelgalil, Gaber Attia Abo-Zaid, Mohamed Mohamed Yousri Kaddah
Abstract:
Background: The Environmental Protection Agency has listed eggshell waste as the 15th most significant food industry pollution hazard. The utilization of eggshell waste as a source of renewable energy has been a hot topic in recent years. Therefore, finding a sustainable solution for the recycling and valorization of eggshell waste by investigating its potential to produce acid phosphatase (ACP) and organic acids by the newly-discovered B. sonorensis was the target of the current investigation. Results: The most potent ACP-producing B. sonorensis strain ACP2 was identified as a local bacterial strain obtained from the effluent of paper and pulp industries on basis of molecular and morphological characterization. The use of consecutive statistical experimental approaches of Plackett-Burman Design (PBD), and Orthogonal Central Composite Design (OCCD), followed by pH-uncontrolled cultivation conditions in a 7 L bench-top bioreactor, revealed an innovative medium formulation that substantially improved ACP production, reaching 216 U L⁻¹ with ACP yield coefficient Yp/x of 18.2 and a specific growth rate (µ) of 0.1 h⁻¹. The metals Ag+, Sn+, and Cr+ were the most efficiently released from eggshells during the solubilization process by B. sonorensis. The uncontrolled pH culture condition is the most suited and favored setting for improving the ACP and organic acids production simultaneously. Quantitative and qualitative analyses of produced organic acids were carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Lactic acid, citric acid, and hydroxybenzoic acid isomer were the most common organic acids produced throughout the cultivation process. The findings of thermogravimetric analysis (TGA), differential scan calorimeter (DSC), scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD) analysis emphasize the significant influence of organic acids and ACP activity on the solubilization of eggshells particles. Conclusions: This study emphasized robust microbial engineering approaches for the large-scale production of a newly discovered acid phosphatase accompanied by organic acids production from B. sonorensis. The biovalorization of the eggshell waste and the production of cost-effective ACP and organic acids were integrated into the current study, and this was done through the implementation of a unique and innovative medium formulation design for eggshell waste management, as well as scaling up ACP production on a bench-top scale.Keywords: chicken eggshells waste, bioremediation, statistical experimental design, batch fermentation
Procedia PDF Downloads 376528 Influence of Strain on the Corrosion Behavior of Dual Phase 590 Steel
Authors: Amit Sarkar, Jayanta K. Mahato, Tushar Bhattacharya, Amrita Kundu, P. C. Chakraborti
Abstract:
With increasing the demand for safety and fuel efficiency of automobiles, automotive manufacturers are looking for light weight, high strength steel with excellent formability and corrosion resistance. Dual-phase steel is finding applications in automotive sectors, because of its high strength, good formability, and high corrosion resistance. During service automotive components suffer from environmental attack and thereby gradual degradation of the components occurs reducing the service life of the components. The objective of the present investigation is to assess the effect of deformation on corrosion behaviour of DP590 grade dual phase steel which is used in automotive industries. The material was received from TATA Steel Jamshedpur, India in the form of 1 mm thick sheet. Tensile properties of the steel at strain rate of 10-3 sec-1: 0.2 % Yield Stress is 382 MPa, Ultimate Tensile Strength is 629 MPa, Uniform Strain is 16.30% and Ductility is 29%. Rectangular strips of 100x10x1 mm were machined keeping the long axis of the strips parallel to rolling direction of the sheet. These strips were longitudinally deformed at a strain rate at 10-3 sec-1 to a different percentage of strain, e.g. 2.5, 5, 7.5,10 and 12.5%, and then slowly unloaded. Small specimens were extracted from the mid region of the unclamped portion of these deformed strips. These small specimens were metallographic polished, and corrosion behaviour has been studied by potentiodynamic polarization, electrochemical impedance spectra, and cyclic polarization and potentiostatic tests. Present results show that among three different environments, the 3.5 pct NaCl solution is most aggressive in case of DP 590 dual-phase steel. It is observed that with the increase in the amount of deformation, corrosion rate increases. With deformation, the stored energy increases and leads to enhanced corrosion rate. Cyclic polarization results revealed highly deformed specimen are more prone to pitting corrosion as compared to the condition when amount of deformation is less. It is also observed that stability of the passive layer decreases with the amount of deformation. With the increase of deformation, current density increases in a passive zone and passive zone is also decreased. From Electrochemical impedance spectroscopy study it is found that with increasing amount of deformation polarization resistance (Rp) decreases. EBSD results showed that average geometrically necessary dislocation density increases with increasing strain which in term increased galvanic corrosion as dislocation areas act as the less noble metal.Keywords: dual phase 590 steel, prestrain, potentiodynamic polarization, cyclic polarization, electrochemical impedance spectra
Procedia PDF Downloads 429527 Glass-Ceramics for Emission in the IR Region
Authors: V. Nikolov, I. Koseva, R. Sole, F. Diaz
Abstract:
Cr4+ doped oxide compounds are particularly preferred active media for solid-state lasers with a wide emission region from 1.1 to 1.6 µm. However, obtaining of single crystals of these compounds is often problematic. An alternative solution of this problem is replacing the single crystals with a transparent glassceramics containing the desired crystalline phase. Germanate compounds, especially Li2MgGeO4, Li2ZnGeO4 and Li2CaGeO4, are suitable for Cr4+ doped glass-ceramics because of their relatively low melting temperature and tetrahedral coordination of all ions. The latter ensures the presence of chromium in the 4+ valence. Cr doped Li2CaGeO4 g lass-ceramic was synthesized by thermal treating using glasses from the Li2O-CaO-GeO2-B2O3 system. Special investigations were carried out for optimizing the initial glasscomposition, as well as the thermal treated conditions. The synthesis of the glass ceramics was accompanied by appropriate characterization methods such as: XRD, TEM, EPR, UVVIS-NIR, emission spectra and time decay as main characteristic for the laser emission. From the systematic studies carried out in the four-component system Li2O-CaO-GeO2-B2O3 for establishing the Li2CaGeO4 crystallization area and suitable thermal treatment conditions, several main conclusions can be drawn: 1. The crystallization region of Li2CaGeO4 is relatively narrow, localized around the stoichiometric composition of the Li2CaGeO4 compound. 2. The presence of the glass former B2O3 strongly supports the obtaining of homogeneous glasses at relatively low temperatures, but it is also the reason for the crystallization of borate phases. 3. The crystallization of glasses during thermal treatment is related to the production of more than one phase and it is correct to speak for crystallization of a main phase and accompanying crystallization of other phases. The crystallization of a given phase is related to changing the composition of the residual glass and creating conditions for the crystallization of other phases. 4. The separate studies show that glass-ceramics with different crystallized phases in different quantitative ratios can be obtained from the same composition of glass playing by the thermal treatment conditions. In other words, the choice of temperature and time of thermal treatment of the glass is an extremely important condition, along with the optimization of the starting glass composition. As a result of the conducted research, an optimal composition of the starting glass and an optimal mode of thermal treatment were selected. Glass-ceramic with a main phase Li2CaGeO4 doped by Cr4+ was obtained. The obtained glass-ceramic possess very good properties containing up to 60 mass% of Li2CaGeO4, with an average size of nanoparticles of 20 nm and with transparency about 70 % relative to the transparency of the parent glass. The emission of the obtained glass-ceramics is in a wide range between 1050 and 1500 nm. The obtained results are the basis for further optimization of the glass-ceramic characteristics to obtain an effective laser-active medium with radiation in the 1.1-1.6 nm range.Keywords: glass, glass-ceramics, multicomponent systems, NIR emission
Procedia PDF Downloads 19526 Ex-vivo Bio-distribution Studies of a Potential Lung Perfusion Agent
Authors: Shabnam Sarwar, Franck Lacoeuille, Nadia Withofs, Roland Hustinx
Abstract:
After the development of a potential surrogate of MAA, and its successful application for the diagnosis of pulmonary embolism in artificially embolized rats’ lungs, this microparticulate system were radiolabelled with gallium-68 to synthesize 68Ga-SBMP with high radiochemical purity >99%. As a prerequisite step of clinical trials, 68Ga- labelled starch based microparticles (SBMP) were analysed for their in-vivo behavior in small animals. The purpose of the presented work includes the ex-vivo biodistribution studies of 68Ga-SBMP in order to assess the activity uptake in target organs with respect to time, excretion pathways of the radiopharmaceutical, %ID/g in major organs, T/NT ratios, in-vivo stability of the radiotracer and subsequently the microparticles in the target organs. Radiolabelling of starch based microparticles was performed by incubating it with 68Ga generator eluate (430±26 MBq) at room temperature and pressure without using any harsh reaction condition. For Ex-vivo biodistribution studies healthy White Wistar rats weighing between 345-460 g were injected intravenously 68Ga-SBMP 20±8 MBq, containing about 2,00,000-6,00,000 SBMP particles in a volume of 700µL. The rats were euthanized at predefined time intervals (5min, 30min, 60min and 120min) and their organ parts were cut, washed, and put in the pre-weighed tubes and measured for radioactivity counts through automatic Gamma counter. The 68Ga-SBMP produced >99% RCP just after 10-20 min incubation through a simple and robust procedure. Biodistribution of 68Ga-SBMP showed that initially just after 5 min post injection major uptake was observed in the lungs following by blood, heart, liver, kidneys, bladder, urine, spleen, stomach, small intestine, colon, skin and skeleton, thymus and at last the smallest activity was found in brain. Radioactivity counts stayed stable in lungs with gradual decrease with the passage of time, and after 2h post injection, almost half of the activity were seen in lungs. This is a sufficient time to perform PET/CT lungs scanning in humans while activity in the liver, spleen, gut and urinary system decreased with time. The results showed that urinary system is the excretion pathways instead of hepatobiliary excretion. There was a high value of T/NT ratios which suggest fine tune images for PET/CT lung perfusion studies henceforth further pre-clinical studies and then clinical trials should be planned in order to utilize this potential lung perfusion agent.Keywords: starch based microparticles, gallium-68, biodistribution, target organs, excretion pathways
Procedia PDF Downloads 173525 A Markov Model for the Elderly Disability Transition and Related Factors in China
Authors: Huimin Liu, Li Xiang, Yue Liu, Jing Wang
Abstract:
Background: As one of typical case for the developing countries who are stepping into the aging times globally, more and more older people in China might face the problem of which they could not maintain normal life due to the functional disability. While the government take efforts to build long-term care system and further carry out related policies for the core concept, there is still lack of strong evidence to evaluating the profile of disability states in the elderly population and its transition rate. It has been proved that disability is a dynamic condition of the person rather than irreversible so it means possible to intervene timely on them who might be in a risk of severe disability. Objective: The aim of this study was to depict the picture of the disability transferring status of the older people in China, and then find out individual characteristics that change the state of disability to provide theory basis for disability prevention and early intervention among elderly people. Methods: Data for this study came from the 2011 baseline survey and the 2013 follow-up survey of the China Health and Retirement Longitudinal Study (CHARLS). Normal ADL function, 1~2 ADLs disability,3 or above ADLs disability and death were defined from state 1 to state 4. Multi-state Markov model was applied and the four-state homogeneous model with discrete states and discrete times from two visits follow-up data was constructed to explore factors for various progressive stages. We modeled the effect of explanatory variables on the rates of transition by using a proportional intensities model with covariate, such as gender. Result: In the total sample, state 2 constituent ratio is nearly about 17.0%, while state 3 proportion is blow the former, accounting for 8.5%. Moreover, ADL disability statistics difference is not obvious between two years. About half of the state 2 in 2011 improved to become normal in 2013 even though they get elder. However, state 3 transferred into the proportion of death increased obviously, closed to the proportion back to state 2 or normal functions. From the estimated intensities, we see the older people are eleven times as likely to develop at 1~2 ADLs disability than dying. After disability onset (state 2), progression to state 3 is 30% more likely than recovery. Once in state 3, a mean of 0.76 years is spent before death or recovery. In this model, a typical person in state 2 has a probability of 0.5 of disability-free one year from now while the moderate disabled or above has a probability of 0.14 being dead. Conclusion: On the long-term care cost considerations, preventive programs for delay the disability progression of the elderly could be adopted based on the current disabled state and main factors of each stage. And in general terms, those focusing elderly individuals who are moderate or above disabled should go first.Keywords: Markov model, elderly people, disability, transition intensity
Procedia PDF Downloads 290524 A Comparative Study of Cardio Respiratory Efficiency between Aquatic and Track and Field Performers
Authors: Sumanta Daw, Gopal Chandra Saha
Abstract:
The present study was conducted to explore the basic pulmonary functions which may generally vary according to the bio-physical characteristics including age, height, body weight, and environment etc. of the sports performers. Regular and specific training exercises also change the characteristics of an athlete’s prowess and produce a positive effect on the physiological functioning, mostly upon cardio-pulmonary efficiency and thereby improving the body mechanism. The objective of the present study was to compare the differences in cardio-respiratory functions between aquatics and track and field performers. As cardio-respiratory functions are influenced by pulse rate and blood pressure (systolic and diastolic), so both of the factors were also taken into consideration. The component selected under cardio-respiratory functions for the present study were i) FEVI/FVC ratio (forced expiratory volume divided by forced vital capacity ratio, i.e. the number represents the percentage of lung capacity to exhale in one second) ii) FVC1 (this is the amount of air which can force out of lungs in one second) and iii) FVC (forced vital capacity is the greatest total amount of air forcefully breathe out after breathing in as deeply as possible). All the three selected components of the cardio-respiratory efficiency were measured by spirometry method. Pulse rate was determined manually. The radial artery which is located on the thumb side of our wrist was used to assess the pulse rate. Blood pressure was assessed by sphygmomanometer. All the data were taken in the resting condition. 36subjects were selected for the present study out of which 18were water polo players and rest were sprinters. The age group of the subjects was considered between 18 to 23 years. In this study the obtained data inform of digital score were treated statistically to get result and draw conclusions. The Mean and Standard Deviation (SD) were used as descriptive statistics and the significant difference between the two subject groups was assessed with the help of statistical ‘t’-test. It was found from the study that all the three components i.e. FEVI/FVC ratio (p-value 0.0148 < 0.01), FVC1 (p-value 0.0010 < 0.01) and FVC (p-value 0.0067 < 0.01) differ significantly as water polo players proved to be better in terms of cardio-respiratory functions than sprinters. Thus study clearly suggests that the exercise training as well as the medium of practice arena associated with water polo players has played an important role to determine better cardio respiratory efficiency than track and field athletes. The outcome of the present study revealed that the lung function in land-based activities may not provide much impact than that of in water activities.Keywords: cardio-respiratory efficiency, spirometry, water polo players, sprinters
Procedia PDF Downloads 134523 Challenges Faced by the Parents of Mentally Challenged Children in India
Authors: Chamaraja Parulli
Abstract:
Family is an important social institution devoted to the growth of a child, and parents are the important agents of socialization. Mentally challenged children are those who are affected by intellectual disability, which is manifested by limitation in intellectual functioning and adoptive behavior. Intellectual disability affects about 3-4 percentage of the general population. Intellectual disability is caused by genetic condition, problems during pregnancy, problems during childbirth, or illness. Mental retardation is the world’s most complex and challenging issue. The stigmatization of disability results in social and economic marginalization. Parents of the mentally challenged children will have a very high level of parenting stress, which is significantly more than the stress perceived by the parents of the children without disability. The prevalence of severe mental disorder called Schizophrenia is among 1.1 percent of the total population in India. On the other hand, 11 to 12 percent is the overall lifetime occurrence rate of mental disorders. While the government has a separate program for mental health, the segment is marred by lack of adequate doctors and infrastructure. Mentally retarded children have certain limitations in mental functioning and skills, which makes them slow learners in speaking, walking, and taking care of their personal needs such as dressing and eating. Accepting a child with mental handicap becomes difficult for parents and to the whole family, as they have to face many problems, including those of management, finance, deprivation of rest, and leisure. Also, the problems faced by the parents can be seen in different areas like – educational, psychological, social, emotional, financial and family related issues. The study brought out various difficulties and problems faced by the parents as well as family members. The findings revealed that the mental retardation is not only a medico-psychological problem but also a socio-cultural problem. The study results, however, indicate that the quality of life of the family having children with mental retardation can be improved to a greater extent by building up a child-friendly ambience at home. The main aim of the present study is to assess the problems faced by the parents of mentally challenged children, with the help of personal interview data collected from the parents of mentally challenged children, residing in Shimoga District of Karnataka State, India. These individuals were selected using stratified random sampling method. Organizing effective intervention programs for parents, family, society, and educational institutions towards reduction of family stress, augmenting the family’s strengths, increasing child’s competence and enhancing the positive attitudes and values of the society will go a long way for the peaceful existence of the mentally challenged children.Keywords: mentally challenged children, intellectual disability, special children, social infrastructure, differently abled, psychological stress, marginalization
Procedia PDF Downloads 109522 Impact of Experiential Learning on Executive Function, Language Development, and Quality of Life for Adults with Intellectual and Developmental Disabilities (IDD)
Authors: Mary Deyo, Zmara Harrison
Abstract:
This study reports the outcomes of an 8-week experiential learning program for 6 adults with Intellectual and Developmental Disabilities (IDD) at a day habilitation program. The intervention foci for this program include executive function, language learning in the domains of expressive, receptive, and pragmatic language, and quality of life. The interprofessional collaboration aimed at supporting adults with IDD to reach person-centered, functional goals across skill domains is critical. This study is a significant addition to the speech-language pathology literature in that it examines a therapy method that potentially meets this need while targeting domains within the speech-language pathology scope of practice. Communication therapy was provided during highly valued and meaningful hands-on learning experiences, referred to as the Garden Club, which incorporated all aspects of planting and caring for a garden as well as related journaling, sensory, cooking, art, and technology-based activities. Direct care staff and an undergraduate research assistant were trained by SLP to be impactful language guides during their interactions with participants in the Garden Club. SLP also provided direct therapy and modeling during Garden Club. Research methods used in this study included a mixed methods analysis of a literature review, a quasi-experimental implementation of communication therapy in the context of experiential learning activities, Quality of Life participant surveys, quantitative pre- post- data collection and linear mixed model analysis, qualitative data collection with qualitative content analysis and coding for themes. Outcomes indicated overall positive changes in expressive vocabulary, following multi-step directions, sequencing, problem-solving, planning, skills for building and maintaining meaningful social relationships, and participant perception of the Garden Project’s impact on their own quality of life. Implementation of this project also highlighted supports and barriers that must be taken into consideration when planning similar projects. Overall findings support the use of experiential learning projects in day habilitation programs for adults with IDD, as well as additional research to deepen understanding of best practices, supports, and barriers for implementation of experiential learning with this population. This research provides an important contribution to research in the fields of speech-language pathology and other professions serving adults with IDD by describing an interprofessional experiential learning program with positive outcomes for executive function, language learning, and quality of life.Keywords: experiential learning, adults, intellectual and developmental disabilities, expressive language, receptive language, pragmatic language, executive function, communication therapy, day habilitation, interprofessionalism, quality of life
Procedia PDF Downloads 127521 Person-Centered Approaches in Face-to-Face Interventions to Support Enrolment in Cardiac Rehabilitation: A Scoping Review Study
Authors: Birgit Rasmussen, Thomas Maribo, Bente S. Toft
Abstract:
BACKGROUND: Cardiac rehabilitation is the standard treatment for ischemic heart disease. Cardiac rehabilitation improves quality of life, reduces mortality and the risk of readmission, and provides patients with valuable knowledge and encouragement from peers and staff. Still, less than half of eligible patients enroll. Face-to-face interventions have the potential to support patients' decision-making and increase enrolment in cardiac rehabilitation. However, we lack knowledge of the content and characteristics of interventions. AIM: The aim was to outline and evaluate the content and characteristics of studies that have reported on face-to-face interventions to encourage enrolment in cardiac rehabilitation in patients with ischemic heart disease. METHOD: This scoping review followed the Joanne Briggs Institute methodology. Based on an a-priori protocol that defined the systematic search criteria, six databases were searched for studies published between 2001 and 2023. Two reviewers independently screened and selected studies. All authors discussed the summarized data prior to the narrative presentation. RESULTS: After screening and full text review of 5583 records, 20 studies of heterogeneous design and content were included. Four studies described the key contents in face-to-face interventions to be education, support of autonomy, addressing reasons for change, and emotional and cognitive support while showing understanding. Two studies used motivational interviewing to target patients' experiences and address worries and anticipated difficulties. Four quantitative studies found associations between enrolment and intention to attend, cardiac rehabilitation barriers, exercise self-efficacy, and perceived control. When patients asked questions, enrolment rates were higher, while providing reassurance and optimism could lead to non-attendance if patients had a high degree of worry. In qualitative studies, support to overcome barriers and knowledge about health benefits from participation in cardiac rehabilitation facilitated enrolment. Feeling reassured that the cardiac condition was good could lead to non-attendance. DISCUSSION AND CONCLUSION: To support patients' enrolment in cardiac rehabilitation, it is recommended that interventions integrate a person-centered dialogue. Individual worries and barriers to cardiac rehabilitation should be jointly explored. When talking with patients for whom worries predominate, the recommendation is to focus on the patients' perspectives and avoid too much focus on reassurance and problem-solving. The patients' perspectives, the mechanisms of change, and the process evaluation of the intervention including person-centeredness are relevant to include in future studies.Keywords: ischemic heart disease, cardiac rehabilitation, enrolment, person-centered, in-hospital interventions
Procedia PDF Downloads 67520 Gender Gap in Returns to Social Entrepreneurship
Authors: Saul Estrin, Ute Stephan, Suncica Vujic
Abstract:
Background and research question: Gender differences in pay are present at all organisational levels, including at the very top. One possible way for women to circumvent organizational norms and discrimination is to engage in entrepreneurship because, as CEOs of their own organizations, entrepreneurs largely determine their own pay. While commercial entrepreneurship plays an important role in job creation and economic growth, social entrepreneurship has come to prominence because of its promise of addressing societal challenges such as poverty, social exclusion, or environmental degradation through market-based rather than state-sponsored activities. This opens the research question whether social entrepreneurship might be a form of entrepreneurship in which the pay of men and women is the same, or at least more similar; that is to say there is little or no gender pay gap. If the gender gap in pay persists also at the top of social enterprises, what are the factors, which might explain these differences? Methodology: The Oaxaca-Blinder Decomposition (OBD) is the standard approach of decomposing the gender pay gap based on the linear regression model. The OBD divides the gender pay gap into the ‘explained’ part due to differences in labour market characteristics (education, work experience, tenure, etc.), and the ‘unexplained’ part due to differences in the returns to those characteristics. The latter part is often interpreted as ‘discrimination’. There are two issues with this approach. (i) In many countries there is a notable convergence in labour market characteristics across genders; hence the OBD method is no longer revealing, since the largest portion of the gap remains ‘unexplained’. (ii) Adding covariates to a base model sequentially either to test a particular coefficient’s ‘robustness’ or to account for the ‘effects’ on this coefficient of adding covariates might be problematic, due to sequence-sensitivity when added covariates are correlated. Gelbach’s decomposition (GD) addresses latter by using the omitted variables bias formula, which constructs a conditional decomposition thus accounting for sequence-sensitivity when added covariates are correlated. We use GD to decompose the differences in gaps of pay (annual and hourly salary), size of the organisation (revenues), effort (weekly hours of work), and sources of finances (fees and sales, grants and donations, microfinance and loans, and investors’ capital) between men and women leading social enterprises. Database: Our empirical work is made possible by our collection of a unique dataset using respondent driven sampling (RDS) methods to address the problem that there is as yet no information on the underlying population of social entrepreneurs. The countries that we focus on are the United Kingdom, Spain, Romania and Hungary. Findings and recommendations: We confirm the existence of a gender pay gap between men and women leading social enterprises. This gap can be explained by differences in the accumulation of human capital, psychological and social factors, as well as cross-country differences. The results of this study contribute to a more rounded perspective, highlighting that although social entrepreneurship may be a highly satisfying occupation, it also perpetuates gender pay inequalities.Keywords: Gelbach’s decomposition, gender gap, returns to social entrepreneurship, values and preferences
Procedia PDF Downloads 244519 Exploring the Relationship Between Helicobacter Pylori Infection and the Incidence of Bronchogenic Carcinoma
Authors: Jose R. Garcia, Lexi Frankel, Amalia Ardeljan, Sergio Medina, Ali Yasback, Omar Rashid
Abstract:
Background: Helicobacter pylori (H. pylori) is a gram-negative, spiral-shaped bacterium that affects nearly half of the population worldwide and humans serve as the principal reservoir. Infection rates usually follow an inverse relationship with hygiene practices and are higher in developing countries than developed countries. Incidence varies significantly by geographic area, race, ethnicity, age, and socioeconomic status. H. pylori is primarily associated with conditions of the gastrointestinal tract such as atrophic gastritis and duodenal peptic ulcers. Infection is also associated with an increased risk of carcinogenesis as there is evidence to show that H. pylori infection may lead to gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. It is suggested that H. pylori infection may be considered as a systemic condition, leading to various novel associations with several different neoplasms such as colorectal cancer, pancreatic cancer, and lung cancer, although further research is needed. Emerging evidence suggests that H. pylori infection may offer protective effects against Mycobacterium tuberculosis as a result of non-specific induction of interferon- γ (IFN- γ). Similar methods of enhanced immunity may affect the development of bronchogenic carcinoma due to the antiproliferative, pro-apoptotic and cytostatic functions of IFN- γ. The purpose of this study was to evaluate the correlation between Helicobacter pylori infection and the incidence of bronchogenic carcinoma. Methods: The data was provided by a Health Insurance Portability and Accountability Act (HIPAA) compliant national database to evaluate the patients infected versus patients not infected with H. pylori using ICD-10 and ICD-9 codes. Access to the database was granted by the Holy Cross Health, Fort Lauderdale for the purpose of academic research. Standard statistical methods were used. Results:-Between January 2010 and December 2019, the query was analyzed and resulted in 163,224 in both the infected and control group, respectively. The two groups were matched by age range and CCI score. The incidence of bronchogenic carcinoma was 1.853% with 3,024 patients in the H. pylori group compared to 4.785% with 7,810 patients in the control group. The difference was statistically significant (p < 2.22x10-16) with an odds ratio of 0.367 (0.353 - 0.383) with a confidence interval of 95%. The two groups were matched by treatment and incidence of cancer, which resulted in a total of 101,739 patients analyzed after this match. The incidence of bronchogenic carcinoma was 1.929% with 1,962 patients in the H. pylori and treatment group compared to 4.618% with 4,698 patients in the control group with treatment. The difference was statistically significant (p < 2.22x10-16) with an odds ratio of 0.403 (0.383 - 0.425) with a confidence interval of 95%.Keywords: bronchogenic carcinoma, helicobacter pylori, lung cancer, pathogen-associated molecular patterns
Procedia PDF Downloads 183518 The Development of Group Counseling Program for Elderly's Caregivers by Base on Person-Centered Theory to Promoting for the Resilience Quotient in Elderly People
Authors: Jirapan Khruesarn, Wimwipa Boonklin
Abstract:
Background: Currently, Thailand has an aging population. In 2017, the elderly population was over 11.14 million. There will be an increase in the number of elderly people, 8.39 million, some people grumble to themselves and have conflicts with their offspring or those close to them. It is a source of stress. Mental health promotion should be given to the elderly in order to cope with these changes. Due to the family characteristics of Thai society, these family members will act as caregivers for the elderly. Therefore, a group-counseling program based on Personnel-Centered Theory for Elderly Caregivers in Mental Health Promotion for Older People in Na Kaeo Municipality, Kau Ka District, Lampang Province, has been developed to compare the elderly care behavior before and after the participation. Methods: This research was study for 20 elderly' caregiver: Those aimed to compare the before and after use of group program for caregiver to promoting for the elderly by the following methods: Step 1 Establish a framework for evaluating elderly care behaviors and develop a group counseling program for promote mental health for elderly on: 1) Body 2) Willpower 3) Social and community management and 4) Organizing learning process. Step 2 Assessing an Elderly Care Behaviors by using "The behavior assessment on caring for the elderly" and assessing the mental health power level of the elderly and follow the counseling program 9 times and compare of the elderly care behaviors before and after joined a group program, and compare of mental health level of caregiver attends a group program. Results: This study is developing a group counseling program to promoting for the resilience quotient in elderly people that the results of the study could be summarized as follows: 1) Before the elderly's caregivers join a group counseling program: Mental health promotion behaviors of the elderly were at the high level of (3.32), and after: were at the high level of (3.44). 2) Before the elderly's caregiver attends a group counseling program: the mental health level of the elderly the mean score was (47.85 percent), and the standard deviation was (0.21 percent) and after. The elderly had a higher score of (51.45 percent) In summary, after the elderly caregivers joined the group, the elderly are higher in all aspects promote mental health for elderly and the statistically significance at the 0.05, It shows that programs are fit for personal and community condition in promoting the mental health of the elderly because this theory has the idea that: Humans have the ability to use their intelligence to solve problems or make decisions effectively, And member of group counseling program have ventured and express grievances that the counselor is a facilitator who focuses on personal development by building relationships among people. In other words, the factors contributing to higher levels of elderly care behaviors is group counseling, that isn't a hypothetical process but focus on building relationships that are based on mutual trust and Unconditional acceptance.Keywords: group counseling base on person-centered theory, elderly person, resilience quotient: RQ, caregiver
Procedia PDF Downloads 91517 The Properties of Risk-based Approaches to Asset Allocation Using Combined Metrics of Portfolio Volatility and Kurtosis: Theoretical and Empirical Analysis
Authors: Maria Debora Braga, Luigi Riso, Maria Grazia Zoia
Abstract:
Risk-based approaches to asset allocation are portfolio construction methods that do not rely on the input of expected returns for the asset classes in the investment universe and only use risk information. They include the Minimum Variance Strategy (MV strategy), the traditional (volatility-based) Risk Parity Strategy (SRP strategy), the Most Diversified Portfolio Strategy (MDP strategy) and, for many, the Equally Weighted Strategy (EW strategy). All the mentioned approaches were based on portfolio volatility as a reference risk measure but in 2023, the Kurtosis-based Risk Parity strategy (KRP strategy) and the Minimum Kurtosis strategy (MK strategy) were introduced. Understandably, they used the fourth root of the portfolio-fourth moment as a proxy for portfolio kurtosis to work with a homogeneous function of degree one. This paper contributes mainly theoretically and methodologically to the framework of risk-based asset allocation approaches with two steps forward. First, a new and more flexible objective function considering a linear combination (with positive coefficients that sum to one) of portfolio volatility and portfolio kurtosis is used to alternatively serve a risk minimization goal or a homogeneous risk distribution goal. Hence, the new basic idea consists in extending the achievement of typical risk-based approaches’ goals to a combined risk measure. To give the rationale behind operating with such a risk measure, it is worth remembering that volatility and kurtosis are expressions of uncertainty, to be read as dispersion of returns around the mean and that both preserve adherence to a symmetric framework and consideration for the entire returns distribution as well, but also that they differ from each other in that the former captures the “normal” / “ordinary” dispersion of returns, while the latter is able to catch the huge dispersion. Therefore, the combined risk metric that uses two individual metrics focused on the same phenomena but differently sensitive to its intensity allows the asset manager to express, in the context of an objective function by varying the “relevance coefficient” associated with the individual metrics, alternatively, a wide set of plausible investment goals for the portfolio construction process while serving investors differently concerned with tail risk and traditional risk. Since this is the first study that also implements risk-based approaches using a combined risk measure, it becomes of fundamental importance to investigate the portfolio effects triggered by this innovation. The paper also offers a second contribution. Until the recent advent of the MK strategy and the KRP strategy, efforts to highlight interesting properties of risk-based approaches were inevitably directed towards the traditional MV strategy and SRP strategy. Previous literature established an increasing order in terms of portfolio volatility, starting from the MV strategy, through the SRP strategy, arriving at the EQ strategy and provided the mathematical proof for the “equalization effect” concerning marginal risks when the MV strategy is considered, and concerning risk contributions when the SRP strategy is considered. Regarding the validity of similar conclusions when referring to the MK strategy and KRP strategy, the development of a theoretical demonstration is still pending. This paper fills this gap.Keywords: risk parity, portfolio kurtosis, risk diversification, asset allocation
Procedia PDF Downloads 65516 Architecture, Politics and Religion Synthesis: Political Legitimacy in Early Islamic Iran
Authors: Fahimeh Ghorbani, Alam Saleh
Abstract:
Ideology, politics and art have always been omnipresent patterns of Islam since its early age. The Islamic empire, expanded from China to Andalusia, has instrumentalized art and architecture to enhance political legitimacy of different dynasties or states throughout its history. Quranic verses utilized to convey ideological messages in the major mosques and mausoleums. Iranians had already been employing art and architecture to propagate their political legitimacy prior to Islam. The land of Iran and its art with strong civilizational pre-Islamic history has been profoundly politicized since the rise of Islam in the region. Early Islamic period in Iran has witnessed introduction of a new architectural language, new formulas for spatial configuration in built spaces, as well as new system of architectural decoration. Studying Iran’s Early Islamic architecture helps in better understanding the process of socio-political identity making of Iranian-Islamic culture, and thus art and architecture. This period also set the stage for formation of glorious architectural movements through Persianate world in later periods. During the Early Islamic period in Iran, the innovative combination of Islamic ideology and Iranian Architecture created formidable ideological tools in politicizing art in the region and beyond. As such, this paper aims to investigate the political history and architectural legacy from late Sassanid to Early Islamic period, delves into the ways in which Early Islamic architecture played role in transforming Persian concepts of kingship, administration, and social organization. In so doing, the study focuses on the Perso-Islamic architectural synthesis under the Samanids and Seljuk dynasty as case studies. The paper also explores how the newly introduced Islamic architecture has been employed to address the question of political legitimacy and to propagate states’ political agenda in early Islamic Iran (650-1250). As for the existing literature, despite its uniqueness and significance, Early Islamic architecture of Iran has received little scholarly attention. However, there exists a sizeable body of scholarship on socio-historic condition of the land of Iran during Early Islamic period which provide a solid base for the project. Methodologically speaking, the authors look into the subject through various lenses. They will conduct historic and archival research in libraries, private collections, and archives in Iran and the related neighbouring countries in Persian, Arabic and English. The methods of visual and formal analysis are applied to examine architectural features of the period. There are also a high number of intriguing, yet poorly examined, published and unpublished documents, old plans, drawings and photos of monuments preserved in Cultural Heritage of Iran Organization which will be consulted.Keywords: Iran, Islamic architecture, early Islamic Iran, early Islamic architecture, politicized art, political legitimacy, propaganda, aesthetics
Procedia PDF Downloads 118515 Placement Characteristics of Major Stream Vehicular Traffic at Median Openings
Authors: Tathagatha Khan, Smruti Sourava Mohapatra
Abstract:
Median openings are provided in raised median of multilane roads to facilitate U-turn movement. The U-turn movement is a highly complex and risky maneuver because U-turning vehicle (minor stream) makes 180° turns at median openings and merge with the approaching through traffic (major stream). A U-turning vehicle requires a suitable gap in the major stream to merge, and during this process, the possibility of merging conflict develops. Therefore, these median openings are potential hot spot of conflict and posses concern pertaining to safety. The traffic at the median openings could be managed efficiently with enhanced safety when the capacity of a traffic facility has been estimated correctly. The capacity of U-turns at median openings is estimated by Harder’s formula, which requires three basic parameters namely critical gap, follow up time and conflict flow rate. The estimation of conflicting flow rate under mixed traffic condition is very much complicated due to absence of lane discipline and discourteous behavior of the drivers. The understanding of placement of major stream vehicles at median opening is very much important for the estimation of conflicting traffic faced by U-turning movement. The placement data of major stream vehicles at different section in 4-lane and 6-lane divided multilane roads were collected. All the test sections were free from the effect of intersection, bus stop, parked vehicles, curvature, pedestrian movements or any other side friction. For the purpose of analysis, all the vehicles were divided into 6 categories such as motorized 2W, autorickshaw (3-W), small car, big car, light commercial vehicle, and heavy vehicle. For the collection of placement data of major stream vehicles, the entire road width was divided into sections of 25 cm each and these were numbered seriatim from the pavement edge (curbside) to the end of the road. The placement major stream vehicle crossing the reference line was recorded by video graphic technique on various weekdays. The collected data for individual category of vehicles at all the test sections were converted into a frequency table with a class interval of 25 cm each and the placement frequency curve. Separate distribution fittings were tried for 4- lane and 6-lane divided roads. The variation of major stream traffic volume on the placement characteristics of major stream vehicles has also been explored. The findings of this study will be helpful to determine the conflict volume at the median openings. So, the present work holds significance in traffic planning, operation and design to alleviate the bottleneck, prospect of collision and delay at median opening in general and at median opening in developing countries in particular.Keywords: median opening, U-turn, conflicting traffic, placement, mixed traffic
Procedia PDF Downloads 138514 The Location-Routing Problem with Pickup Facilities and Heterogeneous Demand: Formulation and Heuristics Approach
Authors: Mao Zhaofang, Xu Yida, Fang Kan, Fu Enyuan, Zhao Zhao
Abstract:
Nowadays, last-mile distribution plays an increasingly important role in the whole industrial chain delivery link and accounts for a large proportion of the whole distribution process cost. Promoting the upgrading of logistics networks and improving the layout of final distribution points has become one of the trends in the development of modern logistics. Due to the discrete and heterogeneous needs and spatial distribution of customer demand, which will lead to a higher delivery failure rate and lower vehicle utilization, last-mile delivery has become a time-consuming and uncertain process. As a result, courier companies have introduced a range of innovative parcel storage facilities, including pick-up points and lockers. The introduction of pick-up points and lockers has not only improved the users’ experience but has also helped logistics and courier companies achieve large-scale economy. Against the backdrop of the COVID-19 of the previous period, contactless delivery has become a new hotspot, which has also created new opportunities for the development of collection services. Therefore, a key issue for logistics companies is how to design/redesign their last-mile distribution network systems to create integrated logistics and distribution networks that consider pick-up points and lockers. This paper focuses on the introduction of self-pickup facilities in new logistics and distribution scenarios and the heterogeneous demands of customers. In this paper, we consider two types of demand, including ordinary products and refrigerated products, as well as corresponding transportation vehicles. We consider the constraints associated with self-pickup points and lockers and then address the location-routing problem with self-pickup facilities and heterogeneous demands (LRP-PFHD). To solve this challenging problem, we propose a mixed integer linear programming (MILP) model that aims to minimize the total cost, which includes the facility opening cost, the variable transport cost, and the fixed transport cost. Due to the NP-hardness of the problem, we propose a hybrid adaptive large-neighbourhood search algorithm to solve LRP-PFHD. We evaluate the effectiveness and efficiency of the proposed algorithm by using instances generated based on benchmark instances. The results demonstrate that the hybrid adaptive large neighbourhood search algorithm is more efficient than MILP solvers such as Gurobi for LRP-PFHD, especially for large-scale instances. In addition, we made a comprehensive analysis of some important parameters (e.g., facility opening cost and transportation cost) to explore their impacts on the results and suggested helpful managerial insights for courier companies.Keywords: city logistics, last-mile delivery, location-routing, adaptive large neighborhood search
Procedia PDF Downloads 78513 Hydrographic Mapping Based on the Concept of Fluvial-Geomorphological Auto-Classification
Authors: Jesús Horacio, Alfredo Ollero, Víctor Bouzas-Blanco, Augusto Pérez-Alberti
Abstract:
Rivers have traditionally been classified, assessed and managed in terms of hydrological, chemical and / or biological criteria. Geomorphological classifications had in the past a secondary role, although proposals like River Styles Framework, Catchment Baseline Survey or Stroud Rural Sustainable Drainage Project did incorporate geomorphology for management decision-making. In recent years many studies have been attracted to the geomorphological component. The geomorphological processes and their associated forms determine the structure of a river system. Understanding these processes and forms is a critical component of the sustainable rehabilitation of aquatic ecosystems. The fluvial auto-classification approach suggests that a river is a self-built natural system, with processes and forms designed to effectively preserve their ecological function (hydrologic, sedimentological and biological regime). Fluvial systems are formed by a wide range of elements with multiple non-linear interactions on different spatial and temporal scales. Besides, the fluvial auto-classification concept is built using data from the river itself, so that each classification developed is peculiar to the river studied. The variables used in the classification are specific stream power and mean grain size. A discriminant analysis showed that these variables are the best characterized processes and forms. The statistical technique applied allows to get an individual discriminant equation for each geomorphological type. The geomorphological classification was developed using sites with high naturalness. Each site is a control point of high ecological and geomorphological quality. The changes in the conditions of the control points will be quickly recognizable, and easy to apply a right management measures to recover the geomorphological type. The study focused on Galicia (NW Spain) and the mapping was made analyzing 122 control points (sites) distributed over eight river basins. In sum, this study provides a method for fluvial geomorphological classification that works as an open and flexible tool underlying the fluvial auto-classification concept. The hydrographic mapping is the visual expression of the results, such that each river has a particular map according to its geomorphological characteristics. Each geomorphological type is represented by a particular type of hydraulic geometry (channel width, width-depth ratio, hydraulic radius, etc.). An alteration of this geometry is indicative of a geomorphological disturbance (whether natural or anthropogenic). Hydrographic mapping is also dynamic because its meaning changes if there is a modification in the specific stream power and/or the mean grain size, that is, in the value of their equations. The researcher has to check annually some of the control points. This procedure allows to monitor the geomorphology quality of the rivers and to see if there are any alterations. The maps are useful to researchers and managers, especially for conservation work and river restoration.Keywords: fluvial auto-classification concept, mapping, geomorphology, river
Procedia PDF Downloads 367512 Analyzing the Effects of Bio-fibers on the Stiffness and Strength of Adhesively Bonded Thermoplastic Bio-fiber Reinforced Composites by a Mixed Experimental-Numerical Approach
Authors: Sofie Verstraete, Stijn Debruyne, Frederik Desplentere
Abstract:
Considering environmental issues, the interest to apply sustainable materials in industry increases. Specifically for composites, there is an emerging need for suitable materials and bonding techniques. As an alternative to traditional composites, short bio-fiber (cellulose-based flax) reinforced Polylactic Acid (PLA) is gaining popularity. However, these thermoplastic based composites show issues in adhesive bonding. This research focusses on analyzing the effects of the fibers near the bonding interphase. The research applies injection molded plate structures. A first important parameter concerns the fiber volume fraction, which directly affects adhesion characteristics of the surface. This parameter is varied between 0 (pure PLA) and 30%. Next to fiber volume fraction, the orientation of fibers near the bonding surface governs the adhesion characteristics of the injection molded parts. This parameter is not directly controlled in this work, but its effects are analyzed. Surface roughness also greatly determines surface wettability, thus adhesion. Therefore, this research work considers three different roughness conditions. Different mechanical treatments yield values up to 0.5 mm. In this preliminary research, only one adhesive type is considered. This is a two-part epoxy which is cured at 23 °C for 48 hours. In order to assure a dedicated parametric study, simple and reproduceable adhesive bonds are manufactured. Both single lap (substrate width 25 mm, thickness 3 mm, overlap length 10 mm) and double lap tests are considered since these are well documented and quite straightforward to conduct. These tests are conducted for the different substrate and surface conditions. Dog bone tensile testing is applied to retrieve the stiffness and strength characteristics of the substrates (with different fiber volume fractions). Numerical modelling (non-linear FEA) relates the effects of the considered parameters on the stiffness and strength of the different joints, obtained through the abovementioned tests. Ongoing work deals with developing dedicated numerical models, incorporating the different considered adhesion parameters. Although this work is the start of an extensive research project on the bonding characteristics of thermoplastic bio-fiber reinforced composites, some interesting results are already prominent. Firstly, a clear correlation between the surface roughness and the wettability of the substrates is observed. Given the adhesive type (and viscosity), it is noticed that an increase in surface energy is proportional to the surface roughness, to some extent. This becomes more pronounced when fiber volume fraction increases. Secondly, ultimate bond strength (single lap) also increases with increasing fiber volume fraction. On a macroscopic level, this confirms the positive effect of fibers near the adhesive bond line.Keywords: adhesive bonding, bio-fiber reinforced composite, flax fibers, lap joint
Procedia PDF Downloads 128511 Improving the Biomechanical Resistance of a Treated Tooth via Composite Restorations Using Optimised Cavity Geometries
Authors: Behzad Babaei, B. Gangadhara Prusty
Abstract:
The objective of this study is to assess the hypotheses that a restored tooth with a class II occlusal-distal (OD) cavity can be strengthened by designing an optimized cavity geometry, as well as selecting the composite restoration with optimized elastic moduli when there is a sharp de-bonded edge at the interface of the tooth and restoration. Methods: A scanned human maxillary molar tooth was segmented into dentine and enamel parts. The dentine and enamel profiles were extracted and imported into a finite element (FE) software. The enamel rod orientations were estimated virtually. Fifteen models for the restored tooth with different cavity occlusal depths (1.5, 2, and 2.5 mm) and internal cavity angles were generated. By using a semi-circular stone part, a 400 N load was applied to two contact points of the restored tooth model. The junctions between the enamel, dentine, and restoration were considered perfectly bonded. All parts in the model were considered homogeneous, isotropic, and elastic. The quadrilateral and triangular elements were employed in the models. A mesh convergence analysis was conducted to verify that the element numbers did not influence the simulation results. According to the criteria of a 5% error in the stress, we found that a total element number of over 14,000 elements resulted in the convergence of the stress. A Python script was employed to automatically assign 2-22 GPa moduli (with increments of 4 GPa) for the composite restorations, 18.6 GPa to the dentine, and two different elastic moduli to the enamel (72 GPa in the enamel rods’ direction and 63 GPa in perpendicular one). The linear, homogeneous, and elastic material models were considered for the dentine, enamel, and composite restorations. 108 FEA simulations were successively conducted. Results: The internal cavity angles (α) significantly altered the peak maximum principal stress at the interface of the enamel and restoration. The strongest structures against the contact loads were observed in the models with α = 100° and 105. Even when the enamel rods’ directional mechanical properties were disregarded, interestingly, the models with α = 100° and 105° exhibited the highest resistance against the mechanical loads. Regarding the effect of occlusal cavity depth, the models with 1.5 mm depth showed higher resistance to contact loads than the model with thicker cavities (2.0 and 2.5 mm). Moreover, the composite moduli in the range of 10-18 GPa alleviated the stress levels in the enamel. Significance: For the class II OD cavity models in this study, the optimal geometries, composite properties, and occlusal cavity depths were determined. Designing the cavities with α ≥100 ̊ was significantly effective in minimizing peak stress levels. The composite restoration with optimized properties reduced the stress concentrations on critical points of the models. Additionally, when more enamel was preserved, the sturdier enamel-restoration interface against the mechanical loads was observed.Keywords: dental composite restoration, cavity geometry, finite element approach, maximum principal stress
Procedia PDF Downloads 102