Assessment of the Hunter Valley Coal Export Supply Chain

We develop a decision support tool that assesses the throughput of a coal export supply chain for a given level of demand. The tool can be used to rapidly evaluate a number of infrastructures for several future demand scenarios in order to identify a few that should be investigated more thoroughly using a detailed simulation model. To make the natural model computationally tractable, we exploit problem structure to reduce the model size, and we employ aggregation as well as disaggregation to strengthen the structure of model. We use the tool in a computational study in which we analyze system performance for different levels of demand to identify potential bottlenecks

Evaluation of Proper Prescription of Antacid Agents in a Group of Critically Ill Children Admitted to PICU in 2018-2019

Background: Critically ill patients, especially those requiring admission to intensive care units (ICU), are at risk for stress-related gastrointestinal mucosal damage. We aimed to evaluate the frequency of proper prescription of antacid agents in a group of critically ill children admitted to PICU. Methods: In this retrospective study, the medical records of children aged between 1 month and 15 years who were admitted in 2018-2019 to the PICU of Imam Hossein children's hospital, Isfahan, Iran, were reviewed. Demographic data, indications for PICU admission, principal diagnosis, the severity of the disease, incidence of bleeding during hospitalization, indications for stress ulcer prophylaxis, prescription of the antacid agents, type of antacid prescribed, and the patient's final outcome were recorded. All the data were gathered and organized by a medical intern. We calculated the rate of the patients who were indicated for SUP, those who were not indicated for SUP (Stress Ulcer Prophylaxis), those who received SUP (Stress Ulcer Prophylaxis), and those who did not receive SUP. Data analysis was performed with the Statistical Package for the Social Sciences software (SPSS, version 24.0, IBM, Armonk, New York). Results: We found that 204 (92.7%) of our patients received antacid agents for gastric SUP. Among the patients receiving SUP, 198 (90%) had an indication for SUP, and only 6 (2.7%) cases received unnecessary prophylaxis? In addition, 16 (7.2%) patients had no indication of receiving SUP and did not receive any prophylaxis. We also reviewed the type of antacid medication that was prescribed for SUP and found that 157 (72%) patients had received PPI, and 57 (30%) had received H2Ras. Conclusions: The findings of the current study revealed that almost all of our study population who had an indication for prophylaxis of stress ulcer appropriately received antacid agents. We suggest that there is a crucial need to conduct large prospective and multicentric studies in pediatric centers to prepare a universally accepted guideline for the prophylaxis of stress ulcers in the pediatric age group

The Relationship between Bone Mineral Density and Serum Vitamin D Levels in Cystic Fibrosis Children

Background: Cystic fibrosis is a multisystemic disorder. It is the most common autosomal recessive disorder in whites that causes complications such as changes in bone density. Therefore, evaluating bone densitometry and serum levels of vitamin D in children with cystic fibrosis is the aim of our study. Methods: This study was performed on 54 children with cystic fibrosis. After recording demographic information, bone densitometry and serum levels of vitamin D were recorded. Chi-square and Pearson correlation tests were used to compare data. Results: Based on our study 53.7% of patients with CF had vitamin D less than 20 nmol / l. It was also found that based on lumbar BMD, 20.3% had a BMD less than 2.5 - Based on femoral BMD, 18.5% had a BMD less than -2.5. And our results demonstrated that there is no relation between BMD with vitamin D, calcium and phosphorus but it is significantly correlated with age, height, weight, and BMI. Conclusion: Decreased BMD is high in patients with CF; on the other hand there is a deficiency of vitamin D in more than 50% of these patients to whom vitamin D supplements should be prescribed along with the standard treatments. Further studies are also required to investigate the effect of other factors on BMD

First Cystic Fibrosis Patient Registry Annual Data Report - Cystic Fibrosis Foundation of Iran

Cystic fibrosis (CF), as a fatal genetic condition, is associated with high morbidity and mortality rates. In Iran, limited studies exist on this disease. This study aims to compare the demographic, clinical and paraclinical data of CF patients. This cross-sectional study was conducted in 2014-2015 on 174 CF patients referred to the Tehran Children Medical Center hospital, which is the main referral center for CF. For each patient, the forced  expiratory volume in one second (FEV1) was measured and the comparative demographic, clinical and laboratory data of patients were recorded. Overall, 59% of studied patients were boys (n=102) and 41% were girls (n=72). The mean patient age (and standard deviations) was 7.1 ±5.7 years, with a range of 10 days to 28 years. In 67% of cases, the disease was diagnosed before their first birthday. The patients in this study were classified based on the FEV1 into mild (62%), moderate (33%) and sever (5%), indicating the degree of pulmonary complications. Cultures of respiratory secretions were positive for Pseudomonas aeruginosa and Staphylococcus aureus, in 23% and 16% of cases, respectively. In total, 61% of patients (n=83) were assigned to receive oral azithromycin for prophylaxis. Gastroesophageal reflux (reflux) was the most common gastrointestinal complication (35%), Regarding the complex nature of CF and the necessity of constant monitoring of patients during the life-span, the comparative demographic, clinical and laboratory analysis of patients and registering and standardization of patients’ data, can be a major step in the better understanding of the disease, and thereby increasing the quality of life and life expectancy in the affected population

Optimising throughput in the Hunter Valley coal chain using integer programming techniques

Research Doctorate - Doctor of Philosophy (PhD)The Hunter Valley Coal Chain (HVCC) is the largest coal export operation in the world. It concerns the transport of coal from mines located in the Hunter Valley to the Port of Newcastle in New South Wales, Australia. Approximately 1700 coal vessels are loaded at the Port of Newcastle and more than 150 million tonnes of coal is exported each year. The HVCC is a complex system involving 14 producers operating 35 coal mines, 27 coal load points, 2 rail track owners, 4 above rail operators, 3 coal loading terminals with a total of 8 berths, and 9 vessel operators. The coal export supply chain is managed by the Hunter Valley Coal Chain Coordinator (HVCCC). One of the most important and far-reaching decision problems faced by HVCCC is the planning of the long-term capacity. The demand for coal continues to grow and thus the export through the Port of Newcastle is expected to increase in the future. Therefore, the infrastructure needs to be upgraded and the capacities in the system expanded. As upgrading infrastructure and expanding the capacity is extremely expensive, a careful and thorough system analysis is crucial to ensure that investments are made in the right place and at the right time. HVCCC uses an elaborate and detailed simulation model of the HVCC to analyse and assess the throughput of the system, to detect and identify any bottlenecks in the system, and to investigate and explore the benefits of infrastructure upgrades and expansions. As the simulation model is very detailed, it takes a considerable amount of time to run, and as a consequence, a few scenarios can be analysed. We develop an integer programming based decision support tool that quickly assesses the throughput of a coal export supply chain for a given level of demand. The tool can be used to rapidly evaluate a number of infrastructures for several future demand scenarios in order to identify a few that should to be investigated more thoroughly using the detailed simulation model. To make the natural integer programming model computationally tractable, we exploit problem structure to reduce the number of variables, and we employ aggregation as well as disaggregation to strengthen the linear programming relaxation. We use the tool in a computational study in which we analyse system performance for different levels of demand to identify the potential bottlenecks. Afterwards, we discover a symmetry in the integer programming model which contributes to a computational issue. By aggregating certain variables, we suggest an aggregated (implicit) integer programming model that can break the symmetry. Applying the Hall’s marriage theorem and the model structure, we provide the required constraints which make the solution of the aggregated model feasible for the original model. As the number of required constraints is considerably large, and most of them are redundant at the optimal solution, a separation algorithm is designed to find those constraints that are necessary and add them in the search tree. A computational study proves the advantage of the aggregated integer model when it encounters with challenging scenarios. Inspired by the HVCC problem, we introduce Production Scheduling with Flexible Deadline Problem. The problem is to satisfy the customer demand with production capacity before its deadline which has to be decided (flexible deadline). We analyse its polyhedron and provide all facet-inducing inequalities which together provides a complete formulation for the cases that the there is one customer and the capacity is either constant or varying. We also generalise the problem to include more demands, and to capture varying arrivals, so that it can resemble a sub-problem of the HVCC problem. We provide two classes of valid inequalities for the generalised problems and explain the way to implement those in the HVCC problem. A computational study shows that these inequalities lead to a stronger formulation for the HVCC problem that shows itself with the higher LP relaxation optimal objective values

تاثير اسپلينت دورسال مچ دست بر سندرم تونل كارپال بر اساس مطالعه هدایت عصب حرکتی مدين

زمينه و هدف : سندرم تونل كارپال يكي از شايع‌ترين نوروپاتيهاي اندام فوقاني است كه در اثر گير افتادن عصب مدين در مچ ايجاد مي‌شود. در اين تحقيق به بررسي نوع جديدي از اسپيلنت(اسپيلنت دورسال مچ دست) در مقايسه با نوع مرسوم (اسپيلنت پالمار) بر اساس پارامترهاي الكترودياگنوزيس پرداخته شده است. روش بررسي: به منظور انجام يك مطالعه نيمه تجربي از نوع كارآزمايي باليني قبل و بعد، 22 بيمار زن مبتلا به CTS خفيف يا متوسط مورد ارزيابي قرار گرفتند.بيماران مبتلا به CTS درمان نشده كه با انجام تست هاي الكترو دياگنوزتيك، مبتلا به نوع خفيف يا متوسط شناخته مي شدند، به طور تصادفي به دو گروه تقسيم شدند. يك گروه (12 نفر)، اسپيلنت دورسال مچ دست و گروه ديگر(10 نفر) اسپيلنت پالمار مچ دست( هر دو در وضعيت نوترال مچ) دريافت نمودند و يك بار قبل از مداخله درماني و بار ديگر به فاصله زماني 4 هفته پس از مداخله درماني، مورد ارزيابي توسط تست هاي الكترودياگنوزتيك قرار گرفتند. متغيرهاي موردبررسي شامل تأخير هدايت حرکتی ديستال عصب مدين، آمپليتود و سرعت هدايت عصب  حرکتی بود. به منظور آناليز داده‌هاي مطالعه از  آزمون هاي  كولمو گروف اسميرونوف، T مستقل و زوج شده استفاده شد. يافته ها : نتايج به دست آمده نشان مي‌دهد كه پارامترهاي هدايت عصب حرکتی مدين در هر دو گروه پالمار و دورسال پس از مداخله 4 هفته اي تغيير قابل ملاحظه اي در جهت بهبود داشته است.(05/0  p<). همچنين مقايسه پارامترهاي الكترودياگنوزيس حرکتی بين دو گروه پس از 4 هفته اختلاف معناداري را نشان نداد. (05/0<p). نتيجه گيري : مطالعه حاضر نشان داد كه به لحاظ علائم الكترودياگنوزيس حرکتی عصب مدين ، هر دواسپلينت دورسال مچ دست و اسپلينت كوكاپ مرسوم در بهبود سندرم تونل كارپال تاثیر مثبت دارند. كليد واژه‌ها: سندرم تونل كارپال ، اسپيلنت دورسال مچ ، سرعت هدايت عصب

Lexical Retrieval or Semantic Knowledge? Which One Causes Naming Errors in Patients with Mild and Moderate Alzheimer’s Disease?

Background: The purpose of the study was to analyze naming errors in patients with Alz­heimer’s disease in comparison to healthy subjects and determine the underlying cause of naming errors in these patients. Method: In this study, we included 35 healthy elderly subjects, 23 patients with mild Alzheimer’s disease, and 23 with moderate Alzheimer’s disease. Forty-five images were used to determine the type of naming errors, and to identify the underlying cause of errors, matching an image with a written word was used. Results: Patients with Alz­heimer’s disease had more naming errors compared with the group of healthy elderly, and patients with moderate Alzheimer’s disease showed a slower reaction in matching an image with a written word. Conclusion: Anomia in the initial phase of Alzheimer’s disease is due to problems in lexical retrieval; however, as the disease advances, in addition to lexical retrieval problems, conceptual knowledge causes naming problems

A Comparison between the Bedside Sonographic Measurements of the Inferior Vena Cava Indices and the Central Venous Pressure While Assessing the Decreased Intravascular Volume in Children

Background: Hemodynamic monitoring is an essential part in the treatment of critically ill patients. Establishment of intravascular volume and creation of a normal systemic perfusion are the most important part to reduce the risk of organ failure and mortality. This study aimed to determine the correlation between the inferior vena cava (IVC) sonographic indices and the central venous pressure (CVP) to provide a useful guide for noninvasive intravascular volume status assessment in children. Materials and Methods: Target sample of children who were admitted to the pediatric critical care unit and required CVP monitoring were enrolled in this study. The collapsibility index (CI) and IVC/aorta (AO) ratio, from bedside ultrasonography measurement of the IVC, were calculated. Results: Of the 70 participants, 22 patients (31.4%) revealed a CVP of 8 mm/Hg or less and 48 patients (68.6%) revealed a CVP >8 mm/Hg. Fifty-six patients (80%) had an IVC-CI of 0.5 or greater and 17 patients (24.3%) had an IVC/AO of 0.8 or less. IVC-CI index is 45.5% sensitive and 91.7% specific with positive predictive value of 71.4 and negative predictive value of 78.6 to predict CVP <8, and the IVC/AO index is 50.8% sensitive and 87.5% specific with a positive predictive value of 64.7 and a negative predictive value of 79.2 to predict CVP <8. Conclusion: Based on the present finding, the IVC sonographic indices provide a useful guide for noninvasive intravascular volume status assessment in children

Reproducibility in Computational Science: A Case Study: Randomness of the Digits of Pi

Mathematical research is undergoing a transformation from a mostly theoretical enterprise to one that involves a significant amount of experimentation. Indeed, computational and experimental mathematics is now a full-fledged discipline with mathematics, and the larger field of computational science is now taking its place as an experimental discipline on a par with traditional experimental fields. In this new realm, reproducibility comes to the forefront as an essential part of the computational research enterprise, and establishing procedures to ensure and facilitate reproducibility is now a central focus of researchers in the field. In this study, we describe our attempts to reproduce the results of a recently published article by Reinhard Ganz, who concluded that the decimal expansion of pi is not statistically random, based on an analysis of several trillion decimal digits provided by Yee and Kondo. While we are able to reproduce the specific findings of Ganz, additional statistical analysis leads us to reject his overall conclusion

Evaluation of Right Ventricular Function by Tissue Doppler Echocardiography in Asthmatic Children

BackgroundAsthma is the most chronic inflammatory disorder of the airways in children and asthmatic patients can experience cardiac dysfunction, pulmonary hypertension and finally cor pulmonale later in life. We aimed to investigate Right Ventricular (RV) functions in asthmatic children by conventional and tissue Doppler echocardiography (TDE).Materials and Methods Pulmonary function tests, conventional and TDE examinations were performed on 42 asthmatic and 42 age- and gender matched healthy controls subjects (n=42).Results Compared with healthy children the RV wall was statistically thicker among asthmatic patients (P= 0.01). Conventional echocardiography had not significant difference between cases and controls, but TDE had significant difference between these two groups. Peak E’ velocity, A’ velocity, E’/A’ ratio and S’ in lateral and medial sites of tricuspid annulus valve, were significantly differ from control group in our patients (