Airline deregulation: an analysis under different regulatory and operating environments

Like other transportation modes the airline industry has a long history of government regulation. In recent years however the theoretical and empirical bases for air service regulatory schemes have been questioned by opponents of such policies. In Western Europe there have been pressures for relaxation of regulation of the air transport industry with respect to air fares, service frequency and market access. Because changes in such public policies are likely to have a major impact, there is a considerable interest in their possible implications. It is the objective of this study to explore the interactions between fare and service frequency in different competitive environments, and to examine the rivalrous behaviour of airlines and their possible equilibrium position under deregulation. The study also considers the effect of a competing mode (rail) on air carriers performance under various competitive conditions. The individual carrier's performance is quantified in terms of fare, service frequency, resulting generalised costs, market share and financial results. A competition model is developed by which the objectives set above are achieved. The study is divided into three parts. The first part provides a framework within which the competition model can be built. This part also generates the policy questions which must be addressed, should relaxation of regulation take place in Europe. The second part explains the structure of the competition model and its characteristics. The assumptions upon which the model is built and its limitations are also discussed. The model consists of three sub-models: the market share model, the costing model and the reaction model. In the third part, with the aid of the model the policy questions generated in the first part are addressed and the general implications for carriers operating under different competitive conditions are discussed. Finally the technical and the policy conclusions are discussed. It is generally concluded that: competition results in lower fares and a more efficient airline industry; the impacts of competition are not evenly distributed amongst markets, routes and carriers; and the competition on equal terms amongst carriers plays an important role in maintaining the effectiveness of deregulation.Ph

The effect of intra-articular meperidine and bupivacaine 0.5 on postoperative pain of arthroscopic knee surgery; a randomized double blind clinical trial

Background: Arthroscopic knee surgeries have a painful postoperative course, which often necessitates acute pain management. Among different analgesia techniques, Intra-articular injection is the technique of choice for many pain specialists, based on its confined effect to the surgical site (knee), lack of systemic effects and promotion of safe early ambulation. Objectives: The aim of this study was to compare analgesic effects of intra-articular meperidine, bupivacaine 0.5 or their combination after knee arthroscopic surgery. Patients and Methods: Sixty ASA class I-II patients� candidates for arthroscopy knee surgery enrolled in a randomized double blind study to receive either 20 mL of bupivacaine 0.5; 100 mg meperidine (diluted in normal saline) or bupivacaine 0.5 along with 100 mg meperidine. A written informed consent was obtained from all patients. Postoperative analgesia duration, VAS at 2, 6, 12 and 24 hours, the Results: The bupivacaine-meperidine group had better duration of postoperative analgesia (P = 0.001), latter first analgesic request (P � first analgesic request time, total fentanyl consumption in first 24 hours, patients� satisfaction and adverse effects were recorded. 0.001), lower total fentanyl consumption in first 24 hours after the operation (P = 0.001), less mean VAS at 2 hours (P = 0.001) and more patients� overall satisfaction (P = 0.01) compared with each medication alone. VAS at 6, 12 and 24 postoperative hours were not different between the groups of study. No adverse effects were observed. Conclusions: Although postoperative intra-articular meperidine is a better alternative for bupivacaine, their combination could improve their analgesic effects compared with each other alone. © 2015, Iranian Society of Regional Anesthesia and Pain Medicine (ISRAPM)

Endoscopic screening for precancerous lesions of the esophagus in a high risk area in northern Iran

Background: Esophageal squamous cell carcinoma (ESCC) is a major health problem in many developing countries, including Iran. ESCC has a very poor prognosis, largely due to late diagnosis. As a first step in developing an early detection and treatment program, we conducted a population-based endoscopic screening for ESCC and its precursor lesion, esophageal squamous dysplasia (ESD), in asymptomatic adults from Golestan Province, northern Iran (a high-risk area for ESCC) to evaluate the feasibility of such a program and to document the prevalence and risk factor correlates of ESD. Methods: This cross-sectional study was conducted among participants of the Golestan Cohort Study (GCS), a population-based cohort of 50,000 adults in eastern Golestan Province. Randomly selected GCS participants were invited by telephone. Those who accepted were referred to a central endoscopy clinic. Eligible subjects who consented were asked to complete a brief questionnaire. Detailed information about selected risk factors was obtained from the GCS main database. Endoscopic examination with was performed with Lugol's iodine staining; biopsies were taken from unstained lesions as well as the normally stained mucosa of the esophagus, and the biopsies were diagnosed by expert pathologists according to previously described criteria. Results: In total, 1906 GCS subjects were invited, of whom only 302 (15.8%) were successfully enrolled. Esophagitis (29.5%) and ESD (6.0%) were the most common pathological diagnoses. Turkmen ethnicity (adjusted OR = 8.61; 95%CI: 2.48-29.83), being older than the median age (OR = 7.7; 95% CI: 1.99-29.87), and using deep frying cooking methods (OR = 4.65; 95%CI: 1.19-18.22) were the strongest predictors for ESD. There were significant relationships between esophagitis and smoking (p-value<0.001), drinking hot tea (P value = 0.02) and lack of education (P value = 0.004). Conclusion: We observed a low rate of participation in endoscopic screening. The overall prevalence of ESD was 6.0%. Developing non-endoscopic primary screening methods and screening individuals with one or more risk factors may improve these rates

Mortality and cancer in relation to ABO blood group phenotypes in the Golestan Cohort Study

Background: A few studies have shown an association between blood group alleles and vascular disease, including atherosclerosis, which is thought to be due to the higher level of von Willebrand factor in these individuals and the association of blood group locus variants with plasma lipid levels. No large population-based study has explored this association with overall and cause-specific mortality. Methods: We aimed to study the association between ABO blood groups and overall and cause-specific mortality in the Golestan Cohort Study. In this cohort, 50,045 people 40- to 70-years old were recruited between 2004 and 2008, and followed annually to capture all incident cancers and deaths due to any cause. We used Cox regression models adjusted for age, sex, smoking, socioeconomic status, ethnicity, place of residence, education and opium use. Results: During a total of 346,708 person-years of follow-up (mean duration 6.9 years), 3,623 cohort participants died. Non-O blood groups were associated with significantly increased total mortality (hazard ratio (HR) = 1.09; 95% confidence interval (CI): 1.01 to 1.17) and cardiovascular disease mortality (HR = 1.15; 95% CI: 1.03 to 1.27). Blood group was not significantly associated with overall cancer mortality, but people with group A, group B, and all non-O blood groups combined had increased risk of incident gastric cancer. In a subgroup of cohort participants, we also showed higher plasma total cholesterol and low-density lipoprotein (LDL) in those with blood group A. Conclusions: Non-O blood groups have an increased mortality, particularly due to cardiovascular diseases, which may be due to the effect of blood group alleles on blood biochemistry or their effect on von Willebrand factor and factor VIII levels. \ua9 Etemadi et al

Large body size and sedentary lifestyle during childhood and early adulthood and esophageal squamous cell carcinoma in a high-risk population

Background: Little is known about the association of obesity and physical activity at young ages with subsequent risk of esophageal squamous cell carcinoma (ESCC). Patients and methods: Between 2003 and 2007, we conducted a case-control study in a high-risk population in northeastern Iran. Three hundred ESCC cases and 571 matched controls were recruited. Each individual was shown a standard pictogram, to report body size at ages 15 and 30. Demographic and health-related information, including physical activity at these ages was also collected. Results: In the fully adjusted models, very obese body size (last two pictograms) at age 15 odds ratio (OR) 3.2, 95% confidence interval (CI) 1.3-7.7 and age 30 (OR 3.1; 95% CI 1.1-8.5) were associated with ESCC in women, but not in men. Sedentary work at age 15 (OR 3.3, 95% CI 1.3-8.3) and 30 (OR 18.2, 95% CI 3.9-86.2) were also associated with ESCC risk in women only. The increased risk in women at age 15 remained high after later reduction in body size, while women who became very obese only at age 30 did not show a significantly increased risk. Conclusion: These results highlight the importance of early lifestyle modifications in the context of cancer prevention, particularly in women. © Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved

Dietary intake of benzo(a)pyrene and risk of esophageal cancer in north of Iran

One etiologic factor for high incidence of esophageal squamous cell carcinoma (ESCC) in Golestan (Northeastern Iran) might be exposure to polycyclic aromatic hydrocarbons. We examined whether food and water are major sources of benzo(a)pyrene (BaP) exposure in this population. We used a dietary questionnaire to assess the daily intake of staple food (rice and bread) and water in 3 groups: 40 ESCC Golestan cases, 40 healthy subjects from the same area, and 40 healthy subjects from a low-risk area in Southern Iran. We measured, by high-performance liquid chromatography combined with fluorescence detection, the BaP concentration of bread, rice, and water in samples obtained from these 3 groups and calculated the daily intake of BaP. Mean BaP concentration of staple foods and water was similar and within standard levels in both areas, but the daily intake of BaP was higher in controls from the high-risk area than in controls from the low-risk area (91.4 vs. 70.6 ng/day, P < 0.01). In the multivariate regression analysis, having ESCC had no independent effect on BaP, whereas residence in the low-risk area was associated with a significant decrease in total BaP intake. Polycyclic aromatic hydrocarbons might, along with other risk factors, contribute to the high risk of ESCC in Golestan. Copyright © 2008, Taylor & Francis Group, LLC

Association of tooth loss and oral hygiene with risk of gastric adenocarcinoma

Poor oral health and tooth loss have been proposed as possible risk factors for some chronic diseases, including gastric cancer. However, a small number of studies have tested these associations. We conducted a case-control study in Golestan Province, Iran, that enrolled 309 cases diagnosed with gastric adenocarcinoma (118 noncardia, 161 cardia, and 30 mixed-locations) and 613 sex, age, and neighborhood matched controls. Data on oral health were obtained through physical examination and questionnaire including tooth loss, the number of decayed, missing, and filled teeth, and frequency of tooth brushing. ORs and 95% confidence intervals (95% CI) were obtained using conditional logistic regression models adjusted for potential confounders. Standard one degree-of-freedom linear trend test and a multiple degree-of-freedom global test of the effect of adding oral hygiene variables to the model were also calculated. Our results showed apparent associations between tooth loss and decayed, missing, filled teeth (DMFT) score with risk of gastric cancer, overall and at each anatomic subsite. However, these associations were not monotonic and were strongly confounded by age. The results also showed that subjects who brushed their teeth less than daily were at significantly higher risk for gastric cardia adenocarcinoma ORs (95% CI) of 5.6 (1.6-19.3). We found evidence for an association between oral health and gastric cancer, but the nonmonotonic association, the relatively strong effect of confounder adjustment, and inconsistent results across studies must temper the strength of any conclusions. © 2013 AACR

Prevalence, awareness and risk factors of hypertension in a large cohort of Iranian adult population

Background: There is considerable variation in hypertension prevalence and awareness, and their correlates, across different geographic locations and ethnic groups. We performed this cross-sectional analysis on data from the Golestan Cohort Study (GCS). Methods: Enrollment in this study occurred in 2004-2008, and included 50 045 healthy individuals from Golestan Province in northeastern Iran. Hypertension was defined as a SBP at least 140 mmHg, a DBP at least 90 mmHg, a prior diagnosis of hypertension, or the use of antihypertensive drugs. Potential correlates of hypertension and its awareness were analyzed by logistic regression adjusted for sex, age, BMI, place of residence, literacy, ethnicity, physical activity, smoking, black and green tea consumption and wealth score. Results: Of the total cohort participants, 21 350 (42.7) were hypertensive. Age-standardized prevalence of hypertension, using the 2001 WHO standard world population, was 41.8 (95 confidence interval: 38.3-45.2). Hypertension was directly associated with female sex, increased BMI, Turkmen ethnicity, and lack of physical activity, and inversely associated with drinking black tea and wealth score. Among hypertensive patients, 46.2 were aware of their disease, 17.6 were receiving antihypertensive medication, and 32.1 of the treated patients had controlled hypertension. Hypertension awareness was greater among women, the elderly, overweight and obese patients, and those with a higher wealth score. Conclusion: Hypertension is highly prevalent in rural Iran, many of the affected individuals are unaware of their disease, and the rate of control by antihypertensive medications is low. Increasing hypertension awareness and access to health services, especially among less privileged residents are recommended. © Lippincott Williams and Wilkins

Smoking water-pipe, chewing nass and prevalence of heart disease: A cross-sectional analysis of baseline data from the Golestan Cohort Study, Iran

Objective Water-pipe and smokeless tobacco use have been associated with several adverse health outcomes. However, little information is available on the association between water-pipe use and heart disease (HD). Therefore, we investigated the association of smoking water-pipe and chewing nass (a mixture of tobacco, lime and ash) with prevalent HD. Design Cross-sectional study. Setting Baseline data (collected in 2004-2008) from a prospective population-based study in Golestan Province, Iran. Participants 50 045 residents of Golestan (40-75 years old; 42.4 men). Main outcome measures ORs and 95 CIs from multivariate logistic regression models for the association of water-pipe and nass use with HD prevalence. Results A total of 3051 (6.1) participants reported a history of HD, and 525 (1.1) and 3726 (7.5) reported ever water-pipe or nass use, respectively. Heavy water-pipe smoking was significantly associated with HD prevalence (highest level of cumulative use vs never use, OR=3.75; 95 CI 1.52 to 9.22; p for trend=0.04). This association persisted when using different cut-off points, when restricting HD to those taking nitrate compound medications, and among never cigarette smokers. There was no significant association between nass use and HD prevalence (highest category of use vs never use, OR=0.91; 95 CI 0.69 to 1.20). Conclusions Our study suggests a significant association between HD and heavy water-pipe smoking. Although the existing evidence suggesting similar biological consequences of water-pipe and cigarette smoking make this association plausible, results of our study were based on a modest number of water-pipe users and need to be replicated in further studies

Heart Disease Is Associated With Anthropometric Indices and Change in Body Size Perception Over the Life Course. The Golestan Cohort Study

Background: Cardiovascular disease and obesity are now becoming leading causes of morbidity and mortality in low- and middle-income countries. Objectives: We investigated the relationship between prevalent heart disease (HD) and current anthropometric indices and body size perception over time from adolescence to adulthood in Iran. Methods: We present a cross-sectional analysis of baseline data from a prospective study of adults in Golestan Province, Iran. Demographics, cardiac history, and current anthropometric indices-body mass index, waist circumference, and waist to hip ratio-were recorded. Body size perception for ages 15 years, 30 years, and at the time of interview was assessed via pictograms. Associations of these factors and temporal change in perceived body size with HD were evaluated using multivariable logistic regression models. Results: Complete data were available for 50,044 participants; 6.1% of which reported having HD. Higher body mass index, waist circumference, and waist to hip ratio were associated with HD (p < 0.001). Men had a U-shaped relationship between HD and body size perception at younger ages. For change in body size perception, men and women demonstrated a U-shaped relationship with prevalent HD from adolescence to early adulthood, but a J-shaped pattern from early to late adulthood. Conclusions: HD was associated with anthropometric indices and change in body size perception over time for men and women in Iran. Due to the increasing prevalence of overweight and obesity in low- and middle-income countries, interventions focused on decreasing the cumulative burden of risk factors throughout the life course may be an important component of cardiovascular risk reduction. © 2015 World Heart Federation (Geneva)