Disciplinary Learning From an Authentic Engineering Context

This small-scale design study describes disciplinary learning in mathematical modeling and science from an authentic engineeringthemed module. Current research in tissue engineering served as source material for the module, including science content for readings and a mathematical modeling activity in which students work in small teams to design a model in response to a problem from a client. The design of the module was guided by well-established principles of model-eliciting activities (a special class of problem-solving activities deeply studied in mathematics education) and recently published implementation design principles, which emphasize the portability of model-eliciting activities to many classroom settings. Two mathematical modeling research questions were addressed: 1. What mathematical approaches did student-teams take when they designed mathematical models to evaluate the quality of blood vessel networks? and 2. What attributes of mature mathematical models were captured in the mathematical models that the student-teams designed? One science content research question was addressed: 1. Before and after the module, what aspects of angiogenesis did students describe when they were asked what they knew about the process of blood vessel growth from existing vessels? Participants who field-tested the module included high school students in a summer enrichment program and early college students enrolled in four general-studies mathematics courses. Data collected from participants included mathematical models produced by small teams of students, as well as students’ individual responses before and after the module to a prompt asking them what they knew about the process of new blood vessel growth from existing vessels. The data were analyzed for mathematical model type and science content by adopting methods of grounded theory, in which researchers suspend expectations about what should be in the data and, instead, allow for the emergence of patterns and trends. The mathematical models were further analyzed for mathematical maturity using an a priori coding scheme of attributes of a mathematical model. Analyses showed that student-teams created mathematical models of varying maturity using four different mathematical approaches, and comparisons of students’ responses to the science prompt showed students knew essentially nothing about angiogenesis before the module but described important aspects of angiogenesis after the module. These findings were used to set up an agenda for future research about the design of the module and the relationship between disciplinary learning and authentic engineering problems

Relationship between parenting styles, identity styles and students’ internet addiction in Kerman University of Medical Sciences

Introduction: Improper use of the internet and its subsequent effects has recently started to be considered as an important issue. Students are among the most vulnerable groups regarding this phenomenon. Although internet addiction can be related to different parenting styles, but the use of internet provides an opportunity to seek individual’s identity. Therefore, the present study aimed to investigate the relationship between parenting styles, identity styles and students’ internet addiction in Kerman University of Medical Sciences.Methods: In this descriptive correlational type of research, the study population included all students who were addicted to the internet at Kerman University of Medical Sciences in 2014. The research sample consisted of 375 subjects selected through multi-stage cluster sampling method. All participants completed the questionnaires on internet addiction, parenting and identity styles.Results: Findings showed that among different identity styles, there was a negative correlation between informational identity style and internet addiction. Moreover, there was a positive significant correlation between diffuse/avoidant identity style and internet addiction. Concerning different parenting styles, we could observe a positive significant correlation between permissive parenting style and internet addiction, while there was a negative significant correlation between authoritative parenting style and internet addiction. Additionally, regression analysis results illustrated that students’ internet addiction level could be predicted regarding their identity styles and their parents’ parenting styles.Conclusion: It seems that applying proper parenting styles and providing the requirements of successful identity achievement can lower the incidence of internet addiction

Popularity and Harms of Aural Foreign Bodies: A Descriptive Study of Patients in Baqiyatallah University Hospital, Tehran, Iran.

peer reviewed[en] OBJECTIVE: To evaluate the prevalence of external ear complications among Iranian aural foreign body users attending to otolaryngology clinic of our hospital. METHODS: In this cross-sectional study patients attending to Otolaryngology clinics of Baqiyatallah hospital were enrolled regardless of their age, gender and reason of attending. Patients between 15 and 60 years of age were included in the present study. Those with positive history of chronic ear diseases, ear surgery, congenital ear disorders, trauma to ear or head and neck region or shock wave trauma were excluded from the study. Demographic information as well as data on chief complaint, educational level, frequency and type of used foreign body and findings of physical examination and Otoscopy by a single otolaryngologist were recorded in a predesigned checklist. RESULTS: Eventually 362 patients (232 male and 130 female) with a mean age of 40.32 ± 16.90 years underwent analysis. Of all patients 244 (67.2%) were using a kind of aural foreign body frequently and Cotton bud was the most popular (63.5%) used foreign body among patients. Drying ear canal was the most common (54.9%) reason of using AFBs among study individuals followed by itching (29.5%) and pyorrhea (11.06%). Also 11 (4.5%) patients were using AFBs as a habit with no specific reason. Itching was the most prevalent symptom reported by both aural foreign body users (78%) and non-users (45.5%); however it was significantly higher among AFB users (p = 0.026). Also hearing loss was significantly more reported by AFB users (p = 0.033). A majority of patients had normal physical examination in both AFB users and non-users group. Inflammation of ear canal was significantly more detected in AFB users (p = 0.004). In addition, rate of right ear wax impaction was higher among AFB users (p = 0.016). CONCLUSION: In conclusion we realized that 67.2% of patients attending to Otolaryngology clinic of our hospital were using a kind of aural foreign bodies and itching was the most common chief complaint of these patients

AGENT-BASED MODELING OF ANGIOGENESIS WITHIN DEGRADABLE BIOMATERIAL SCAFFOLDS

The ability to promote and control blood vessel assembly in polymer scaffolds is important for clinical success in tissue engineering. Often, experimental studies are performed to investigate the role of scaffold architecture on vascularized tissue formation. However, experiments are expensive and time-consuming and synthesis protocols often do not allow for independent investigation of specific scaffold properties. Mathematical and computational representation of the relationship between scaffold properties and neovascularization facilitates studying the fundamental processes involved in vascularization of biomaterials and provides more profound understanding of the critical factors that affect this process. This understanding is critical for the design of new therapeutic approaches that could bridge the existing gap between current experimental techniques and the state of the art practical tissue regeneration approaches. Computational models allow for rapid screening of potential material designs with control over scaffold properties that is difficult in laboratory settings. In this work, a multi-layered, multi-agent framework is developed to model the process of sprouting angiogenesis within porous biodegradable tissue engineering scaffolds. Software agents are designed to represent endothelial cells, interacting together and with their micro-environment, leading to formation of new blood vessels that perfuse the scaffold. A rule base, derived from the experimental findings reported in the literature, or observed by our collaborators, governs the behavior of individual agents. Two-dimensional and three-dimensional scaffold models with well-defined homogeneous and heterogeneous pore architectures are designed and simulated to investigate the impact of various scaffold design parameters such as pore size, pore size distribution, interconnectivity, and porosity, as well as the degradation behavior of 2 the scaffolds, on vessel invasion and capillary network structure. Model parameters such as the speed of vessel sprouting or cell migration speed are adjusted based on independent results of in vivo vascularization of fibrin gels in the absence of a polymer scaffold. The effects of various characteristics of scaffold degradation are also investigated. Various scenarios are defined and simulation case studies are developed to investigate the effect of scaffold geometrical and structural properties on angiogenesis. The simulation results are compared with available experimental results of scaffold vascularization performed in our group and with relevant published literature data to validate the developed model. These results indicate that in general the rate of vascularization increases with larger pore size and higher interconnectivity and porosity scaffolds. Pores of larger size (160-270 μm) support rapid and extensive angiogenesis, however vascularizing deeper parts of the scaffolds still remains a challenge that requires more complex scaffold designs. The agent-based model can be used to provide insight into optimal scaffold properties that support vascularization of engineered tissues. The modeling framework developed provides a novel interface for convenient integration of new knowledge to the current computational models, making it possible to gradually increase the level of complexity and accuracy of the models as our knowledge about the underlying biological system advances. The simulation results help us better understand the complex interactions between the growing blood vessel network and a degrading scaffold structure, and identify the optimal combinations of geometric and degradation characteristics of tissue engineering scaffolds that support scaffold vascularization.PH.D in Chemical Engineering, December 201

Comparison and Evaluation of Artificial Neural Network (ANN) Training Algorithms in Predicting Soil Type Classification

International audienceThe present study uses different ANN training algorithms to predict soil type classification and evaluates the output of their training. Studies were done on the soil of Shahrekord (Iran), using a database consists of 120 soil samples. The used data includes the results of standard impact and penetration tests, classification and Atterberg limits. Because of diverse training algorithms in neural networks, the selection of the optimal training function can increase the accuracy of network predictions. For this purpose, several training functions and algorithms were used in the ANN modeling. To evaluate the performance of proposed models, relations of coefficient of residual mass (CRM), coefficient of determination (COD) and root mean square error (RMSE) were used. The comparison and evaluation of training with various algorithms show that the Levenberg-Marquardt training function with very high accuracy in network training is the optimal training function used in the prediction of geotechnical parameters of soil, including soil type

Comparative evaluation of root canal morphology of mandibular premolars using clearing and cone beam computed tomography

Background: Different techniques are used to evaluate the anatomy of root canal system. The present study was aimed to evaluate the root canal morphology of mandibular premolars using clearing and cone beam computed tomography (CBCT) techniques. Materials and Methods: A total of 182 mandibular first and second premolars were evaluated in vitro using 100 μm CBCT cross sections. The root canal morphology of the teeth was determined based on Vertucci classification in relation to the prevalence of C-shaped canals, lateral canals, and furcation location. Having removed the pulp tissue with NaOCl solution and staining the root canals with India ink, the samples were decalcified with 5% nitric acid and dehydrated with isopropyl alcohol. Finally, the samples were cleared with methyl salicylate. Data were analyzed by SPSS 16 software using McNamara, t-test, and Kappa coefficient. Results: After Type I, the most frequent morphologies in both first and second premolars were Type V followed by Type IV. The prevalence rates of C-shaped morphology in first premolars using clearing and CBCT were 4.4% and 6.6%, respectively. However, no C-shaped morphology was found in second premolars. The maximum and minimum levels of agreement between the two techniques were observed in Type IV and Type V root canal morphologies, respectively. Extra root canals were identified in 25% and 13% of the first and second premolars, respectively. Conclusion: CBCT showed a higher accuracy in determining C-shaped root canal morphology than the clearing technique. It also showed the least accuracy in diagnosing lateral root canals

Olfactory Dysfunction in Iranian Diabetic Patients

Olfactory dysfunction is a known complication of diabetes and, despite its importance in the quality of life, is usually neglected due to its gradual progression. In this study, we aim to determine the prevalence and severity of olfactory dysfunction in diabetics and its association with microangiopathic complications of the disease (neuropathy, nephropathy, and retinopathy). Excluding the confounding factors, a case-control study of 60 eligible subjects, divided into a group of 30 diabetic patients and a group of 30 control subjects was performed. We used "absorbent perfumer's paper strips" method to test the olfactory threshold. In our study, 60% of diabetics were found to have some degree of olfactory dysfunction and a significant difference (P<0.01) between the olfactory threshold of the case and control groups was observed. There were no significant associations between the olfactory dysfunction and age, sex, treatment duration and microangiopathic complications

طراحی مدل تصمیم‌‌‌گیری مبتنی بر اخلاق زیستی در صنعت پوشاک

Background and purpose: The context of the bio-ethical decision-making model in the clothing industry is to understand and examine the ethical effects of processes and decisions related to the design, production, distribution and consumption of clothing. This model tries to help companies and organizations related to the clothing industry to make their decisions with ethical consideration and to consider the ethical consequences of their actions.Method: The current research is practical in terms of the type of use, and the exploratory mixed method was used in it, and thematic analysis strategy was used in the qualitative part. The statistical population of the qualitative part included 14 academic and garment industry experts who were selected in a targeted non-probability way. The statistical population was 288 out of the 300 distributed questionnaires. Interviews and questionnaires were used in this research. ., qualitative data analysis was done through open, central and selective three-stage coding and MaxQDA software, and in the quantitative part through confirmatory factor analysis and SmartPL software.Ethical considerations: In this research, the principles of trustworthiness, honesty, neutrality and originality of the work have been respected.Findings: The results of the present research led to the identification of 6 classes of strategies (government policy making, empowering the business environment), intervening factors (social relations, government policies), consequences (sustainable development in the country, increasing the power and strength of sellers and producers, improving the quality level and quantity of customers), background factors (individual and environmental factors), causal factors (internal and external factors), and consumer ethical decision-making (supporting national production, ethical decision-making approaches, avoiding extravagance and luxury, applied environmental ethics) became These findings were also confirmed in the quantitative phase.Conclusion: It is necessary that all social units in the country, from the individual level to the government, focus on the need for ethical decision-making so that this issue is also reflected in consumers.زمینه و هدف: زمینه مدل تصمیم‌گیری بر مبنای اخلاقی زیستی در صنعت پوشاک، درک و بررسی تأثیرات اخلاقی فرایندها و تصمیمات مرتبط با طراحی، تولید، توزیع و مصرف پوشاک است. این مدل تلاش می‌کند تا به شرکت‌ها و سازمان‌های مرتبط با صنعت پوشاک کمک نماید تا تصمیمات خود را با ملاحظه جوانب اخلاقی بگیرند و عواقب اخلاقی اقدامات خود را در نظر داشته باشند. روش: پژوهش حاضر از نظر نوع، کاربردی است و در آن از روش آمیخته اکتشافی استفاده شده است، در بخش کیفی از استراتژی تحلیل مضمون بهره‌گیری شد. جامعه آماری بخش کیفی شامل 14 نفر از خبرگان دانشگاهی و صنعت پوشاک بود که به روش غیر احتمالی هدفمند انتخاب شدند. در بین جامعه آماری از تعداد 300 پرسشنامه توزیع‌شده تعداد 288 عدد از آن‌ها قابل استفاده شده است. در این پژوهش از ابزار مصاحبه و پرسشنامه استفاده گردید. تحلیل داده‌های کیفی از طریق کدگذاری سه‌مرحله‌ای باز، محوری و گزینشی و نرم‌افزار Maxqda 20 و در بخش کمی از طریق تحلیل عاملی تأیید و نرم‌افزار Smart Pls3 انجام شد. ملاحظات اخلاقی: پس از اخذ اجازه از خبرگان دانشگاهی، صنعت پوشاک و بیان اهداف برای شرکت‌کنندگان، رضایت آن‌ها کسب و درباره محرمانگی اطلاعات به آن‌ها اطمینان خاطر داده شد. یافته‌ها: نتایج تحقیق حاضر منجر به شناسایی 6 طبقه راهبرد (سیاستگذاری حاكمیتی، توانمندسازی فضای كسب ‌و كار)، عوامل مداخله‌گر (روابط اجتماعی، سیاست‌های حكومتی)، پیامدها (توسعه پایدار در كشور، افزایش توان و قدرت فروشندگان و تولیدكنندگان، ارتقای سطح كیفی و كمی مشتریان)، عوامل زمینه‎ای (عوامل فردی و محیطی)، عوامل علّی (عوامل درون و برون‌فردی) و تصمیم‌گیری اخلاقی مصرف‌كننده (حمایت از تولید ملی، رویكردهای تصمیم‌گیری اخلاقی، پرهیز از اسراف و تجمل‌گرایی، اخلاق كاربردی زیست‌محیطی) گردید. این یافته‌ها نیز در مرحله کمی مورد تأیید قرار گرفتند. نتیجه‌گیری: ضروری است كه تمامی واحدهای اجتماعی در كشور از سطح فردی تا اركان حكومت بر لزوم تصمیم‌گیری اخلاقی تمركز نمایند تا این موضوع در مصرف‌‌كنندگان نیز منعكس شود.