Modeling the Variability of Labor Productivity in Masonry Construction

This paper proposes a methodology to model the variability of masonry labor productivity. The theoretical basis of baseline productivity relied upon the analysis of 14 projects sharing similar exogenous conditions and being similar in scope, size of components, specifications, quality requirements and design features. The data were collected using standardized data collection procedures that focused on task-level labor productivity; specifically, the measurement of work accomplished by a single crew in a single shift. Analysis showed that when daily productivity values fall between the control limits, loss of productivity is within normal variation while daily productivity values falling above the upper control limit imply a loss of productivity that is due to the work environment factors as within the normal variation, and in particular to certain significant influential factors that can be cited during that day. These results could have significant implications for construction managers seeking to improve overall project performance

Hypoxia-induced gene expression pattern in doxorubicin resistant MCF7 cells

Purpose: To investigate hypoxia-induced gene expression pattern in doxorubicin-resistant human breast cancer cells (MCF7). Methods: Human breast cancer cells (MCF7) were exposed to 60 episodes of 8 h hypoxia thrice a week for three months. Chemo-resistance to doxorubicin was assessed using 3-(4,5-dimethylthiazol-2- yl)-2, 5-diphenyl tetrazolium bromide (MTT) cell proliferation assay. Real-time quantitative polymerase chain reaction (qRT-PCR) assay was performed to assess gene expression pattern in doxorubicinresistant cells on exposure to hypoxia. Results: Hypoxia significantly increased the resistance of MCF7 cells to doxorubicin, with a maximum of 16.42-fold enhancement after 25 episodes of 8-h hypoxia, while the resistance thereafter significantly decreased with prolonged episodes of hypoxia (p < 0.05). Gene expression analysis revealed significant changes in 42 genes. The expressions of 10 of these genes were significantly upregulated, while those of 32 genes were significantly down-regulated (p < 0.05). Cytochrome P450 family 1, subfamily A, member1 (CYP1A1) was the most conspicuous upregulated gene (13.32-fold), while breast cancer gene 1 (BRCA1) was the most down-regulated (8.23-fold). Gene expression analysis after 60 episodes of 8-h hypoxia revealed the upregulation of CYP1A1 (5.77-fold). Similarly, 27 genes were significantly down-regulated, with BRCA2 as the most down-regulated gene (8.11-fold). Topoisomerase (DNA) II alpha (TOP2A) was the most down-regulated among genes involved in drug metabolism and resistance (6.37-fold), while cyclin-dependent kinase 2 (CDK2) was the most profoundly downregulated among genes involved in cell cycle regulation (3.56-fold). Conclusion: These results indicate that development of resistance to doxorubicin by MCF7 cells after short-term hypoxia results from the upregulation of genes responsible for the metabolism of doxorubicin and for shifting the cells to alternative pathway driven principally by EGF and ESR2. The observed down-regulation is an adaptation of the MCF7 cells to survive under long-term hypoxia

A Quantitative Approach to Estimate the Damage Inflicted by Traffic Pollution on Historic Buildings in Al-Salt City, Jordan

Traffic in the city of Al-Salt is not only putting pedestrians at risk and threatening the health of citizens, it is also damaging the town's historic buildings. Most stone buildings in the heritage-rich city are suffering adverse effects from vehicle-related pollution. This effect is highly visible soiling and discoloration from deposited carbon particles in the form of fine soot on most buildings. The level and progress of the damage depends on the geology of the stone and the proximity of the structure from traffic congestion. The accumulation of soot leads to the buildup of black sulfate (gypsum) skins on the limestone facade which causes the sound stone behind it to disintegrate. It is vital to the well-being of this historic treasure that the volume of the city traffic must be reduced and traffic flow improved. The main objective of this study is to qualitatively and quantitatively assess the damage caused to buildings of historical and cultural value by traffic pollution. Age of vehicles running on city’s streets and the rate of their emissions are quantified and analyzed. Several field investigations and laboratory tests were conducted to identify the chemical relations between pollutants and stone decay on these buildings. Keywords: Traffic pollution, tailpipe emission, vehicular emission, historic buildings, limeston

Prediction Model for Construction Cost and Duration in Jordan

Risk is mitigated in the course of reliable prediction. A probabilistic model is proposed to predict the risk effects on time and cost of construction projects. Project managers and consultants can use the model in estimating project cost and duration based on historic data. Statistical regression models and sample tests are developed using real data of 140 projects. The research objective is to develop a model to predict project cost and duration based on historic data of similar projects. The model result can be used by project managers in the planning phase to validate the schedule critical path time and project budget. Research methodology is steered per the following progression: i) Conduct nonparametric test for project cost and time performance. ii) Develop generic multiple-regression models to predict project cost and duration using historic performance data. iii) The percent prediction error is statistically analyzed; and found to be substantial; thus, iv) Custom multiple regression models are developed for each project type to obtain statistically reliable results. In conclusion, the 95% point estimation of error margin= ±0.035%. Therefore, at a probability of 95%, the proposed model predicts the project cost and duration with a precision of ±0.035% of the mean cost and time

Productivity Improvement of Pre-cast Concrete Installation

The production process of pre-cast concrete installation is analyzed to investigate possible ways for onsite productivity improvement. Although manufactured construction enjoys higher quality and productivity, it is observed that it suffers delays compared to site built construction. Delay causes and respective severity are analyzed for improvement. Firstly, the production process is investigated using the production delay model. Forty cycle data are used in the analysis. The comparative impact and severity are measured for five delay causes, namely: labor, environmental, management, equipment and material on overall system productivity. It is found via the production delay analysis that material, followed by equipment availability then labor were major contributors to system delay. Secondly, statistical analysis on the installation cycle time of three pre-cast component types is carried out, in order to insure whether the delay observed via the first step is attributed to variation of pre-cast pieces. The data used in step one above were not pertinent to product type; therefore, other 90 cycle data are utilized in the statistical analysis, which indicated high variability in cycle time due to product type. Improvement can be achieved through proper scheduling of project equipment and resources. In addition, improvement should target the reduction of installation cycle time variability due to product type

Prescribing Antibiotics for pediatric dental patients in Jordan; knowledge and attitudes of dentists

Objective: The inappropriate use of antibiotic in treating children has been observedin the treatment of dental infections. Recent surveys reported that dentistsin several countries have modest knowledge about antibiotic prescribing. The aimof this study was to investigate the knowledge and attitude of a group of Jordaniandentists treating children towards antibiotic prescribing.Methods: A written questionnaire was distributed during a meeting of the JordanianSociety of Paediatric Dentistry. The questionnaire included questions aboutthe knowledge and attitudes of dentists toward dental antibiotic prescribing tochildren.Results: Amoxicillin was the most popular antibiotic (62.9%) to be prescribed bydentists treating children. A lesser percentage (29.7%) prescribe combination ofantibiotics, and around 37% prescribe antibiotics for duration longer than 5 days.Erythromycin was the most popular alternative to amoxicillin (77.8%) followed byclindamycin (22.2%). A number of antibiotics were prescribed for non-indicatedclinical conditions like pulpitis and gingivitis. More than 50% of the sample prescribedantibiotics for non-scientific reasons like the “need to delay treatment†and“sterilization not guaranteedâ€.Conclusion: There is a need to improve awareness of Jordanian dentists regardingantibiotic prescribing to children particularly in the aspects of type of antibiotic tobe used for patients allergic and non-allergic to penicillin, duration of prescribing,and clinical indications. Dentists also should be discouraged to prescribe antibioticsbased on non-scientific/social factors

Body image and its relationship to some psychological variables among students in the secondary stage of education in Saudi Arabia

Introduction. Body image perceptions among adolescents are intrinsically linked to psychological factors such as self-esteem and social comparison. The secondary stage proves to be a critical period for exploring identity, with body image playing a vital role in shaping mental well-being and interpersonal relationships. Aim. The current research aims to examine the differences and to identify the relationship between adolescents in body image and some psychological variables (life satisfaction – psychological adaptation) according to the gender variable (males – females). Methodology and research methods. The sample of the current research consisted of 433 adolescents, with 220 male students and 213 female students; their ages ranged between 16–19 years. To achieve the research objectives, the author adopted the descriptive correlative approach to conduct this study, in addition to using the scale of body image, life satisfaction, and scale of psychological adaptation. After verifying the stability and validity of the tools, they were applied to the study sample. Results. The results revealed differences between male and female adolescents in body image in favour of adolescents, meaning that adolescents are more satisfied with their body image than female adolescents. In addition, there are differences between male and female adolescents in the degree of psychological adjustment in favour of adolescents. However, there are no differences between male and female adolescents in the degree of life satisfaction and there is a positive, statistically significant correlation between life satisfaction and psychological adjustment. Furthermore, there is a positive, statistically significant relationship between the body image scale and the psychological adjustment scale. Scientific novelty. The scientific novelty of this study lies in its comprehensive investigation into the complex interplay between body image and various psychological variables among adolescents in the secondary stage. This study adds to scientific knowledge in several ways. First, it provides insights into the complex relationship between body image and psychological variables among adolescents in the secondary stage, which can inform future research in this area. Second, the study’s findings on gender differences in body image and psychological adjustment can contribute to our understanding of how gender affects mental health outcomes in adolescence. Third, the study highlights the importance of addressing body image issues among adolescents and emphasises the need for targeted interventions and support systems. Overall, this study contributes to the growing body of literature on adolescent mental health and provides important insights for researchers, educators, and mental health professionals working with adolescents. Practical significance. The practical significance of this study lies in its potential to inform educators, parents, and mental health professionals about the importance of addressing body image issues among adolescents. By highlighting the differences in body image satisfaction between genders and the link between body image and psychological factors such as life satisfaction and psychological adjustment, the study emphasises the need for targeted interventions and support systems.Введение. Восприятие образа тела подростками неразрывно связано с психологическими факторами, такими как самооценка и социальное сравнение. Вторичная стадия оказывается критическим периодом для изучения идентичности, когда образ тела играет жизненно важную роль в формировании психического благополучия и межличностных отношений. Цель. Настоящее исследование направлено на изучение у подростков различий и выявление связи образа тела с некоторыми психологическими переменными (удовлетворенность жизнью – психологическая адаптация) на основании гендерного показателя (мужчины – женщины). Методология и методы исследования. Выборка текущего исследования состояла из 433 подростков, из них 220 студентов и 213 студенток; их возраст колебался в пределах 16–19 лет. Для достижения целей исследования автор применил описательный корреляционный подход помимо использования шкалы образа тела, удовлетворенности жизнью и шкалы психологической адаптации. После проверки стабильности и валидности инструментов они были применены к исследуемой выборке. Результаты выявили различия между подростками мужского и женского пола в образе тела в пользу юношей, а это означает, что юноши более удовлетворены образом своего тела, чем девушки. Кроме того, существуют различия между подростками мужского и женского пола по степени психологической адаптации в пользу юношей. Однако между подростками мужского и женского пола отсутствуют различия в степени удовлетворенности жизнью и обнаружена положительная, статистически значимая корреляция между удовлетворенностью жизнью и психологической приспособленностью. Кроме того, существует положительная, статистически значимая связь между шкалой образа тела и шкалой психологической адаптации. Научная новизна этого исследования заключается в его всестороннем изучении сложного взаимодействия между образом тела и различными психологическими переменными у подростков средней школы. Настоящее исследование вносит вклад в научные знания несколькими способами. Во-первых, оно дает представление о сложной взаимосвязи между образом тела и психологическими переменными среди подростков средней школы, что может помочь в будущих исследованиях в этой области. Во-вторых, полученные результаты могут способствовать нашему пониманию того, как пол влияет на результаты психического здоровья в подростковом возрасте. В-третьих, оно подчеркивает важность решения проблем образа тела среди подростков и необходимость целевых вмешательств и систем поддержки. В целом это исследование способствует росту объема литературы о психическом здоровье подростков и предоставляет важную информацию для исследователей, педагогов и специалистов по психическому здоровью, работающих с подростками. Практическая значимость этого исследования заключается в его способности информировать педагогов, родителей и специалистов в области психического здоровья о важности решения проблем образа тела среди подростков. Подчеркивая различия в удовлетворенности образом тела между полами и связь между образом тела и психологическими факторами, такими как удовлетворенность жизнью и психологическая адаптация, исследование демонстрирует необходимость целенаправленных вмешательств и систем поддержки.Этот проект был поддержан Деканатом научных исследований Университета принца Саттама бин Абдулазиза в рамках исследовательского проекта № 2021/02/18592.This project was supported by the Deanship of Scientific Research at Prince Sattam bin Abdul-Aziz University under the research project № 2021/02/18592

Narghile (water pipe) smoking among university students in Jordan: prevalence, pattern and beliefs

<p>Abstract</p> <p>Background and objectives</p> <p>Narghile is becoming the favorite form of tobacco use by youth globally. This problem has received more attention in recent years. The aim of this study was to investigate the prevalence and pattern of narghile use among students in three public Jordanian universities; to assess their beliefs about narghile's adverse health consequences; and to evaluate their awareness of oral health and oral hygiene.</p> <p>Methods</p> <p>The study was a cross-sectional survey of university students. A self-administered, anonymous questionnaire was distributed randomly to university students in three public Jordanian universities during December, 2008. The questionnaire was designed to ask specific questions that are related to smoking in general, and to narghile smoking in specific. There were also questions about oral health awareness and oral hygiene practices.</p> <p>Results</p> <p>36.8% of the surveyed sample indicated they were smokers comprising 61.9% of the male students and 10.7% of the female students in the study sample. Cigarettes and narghile were the preferred smoking methods among male students (42%). On the other hand, female students preferred narghile only (53%). Parental smoking status but not their educational level was associated with the students smoking status. Smokers had also significantly poor dental attendance and poor oral hygiene habits.</p> <p>Conclusion</p> <p>This study confirmed the spreading narghile epidemic among young people in Jordan like the neighboring countries of the Eastern Mediterranean region. Alarming signs were the poor oral health awareness among students particularly smokers.</p