Relationship between the quality of life and the severity of obstructive sleep apnea syndrome

The effects of sleep disorders on the quality of life (QOL) have been documented in the literature. Excessive sleepiness and altered circadian rhythms may negatively affect ability to learn, employment, and interpersonal relations, and directly degrade QOL. The objective of the present study was to evaluate the impact of obstructive sleep apnea syndrome of varying severity on QOL. The study was conducted on 1892 patients aged 18 years or older referred by a physician to the Sleep Institute, São Paulo, with complaints related to apnea (snoring, excessive daytime sleepiness, hyperarousal, and fatigue). They were submitted to overnight polysomnography for the diagnosis of sleep disorders from August 2005 through April 2006. The patients completed the Epworth Sleepiness Scale and QOL SF-36 sleep questionnaires. They were classified as non-physically active and physically active and not-sleepy and sleepy and the results of polysomnography were analyzed on the basis of the apnea hypopnea index (AHI). The apneic subjects showed a reduction in QOL which was proportional to severity. There was a significant decrease in all domains (physical functioning, role physical problems, bodily pain, general health perceptions, vitality, social functioning, emotional problems, general mental health) for apneics with AHI >30, who generally were sleepy and did not participate in physical activities (P < 0.05). The present study provides evidence that the impact of sleep disorders on QOL in apneics is not limited to excessive daytime sleepiness and that physical activity can contribute to reducing the symptoms. Thus, exercise should be considered as an adjunct interventional strategy in the management of obstructive sleep apnea syndrome.

Relationship between Brazilian airline pilot errors and time of day

Flight safety is one of the most important and frequently discussed issues in aviation. Recent accident inquiries have raised questions as to how the work of flight crews is organized and the extent to which these conditions may have been contributing factors to accidents. Fatigue is based on physiologic limitations, which are reflected in performance deficits. The purpose of the present study was to provide an analysis of the periods of the day in which pilots working for a commercial airline presented major errors. Errors made by 515 captains and 472 copilots were analyzed using data from flight operation quality assurance systems. To analyze the times of day (shifts) during which incidents occurred, we divided the light-dark cycle (24:00) in four periods: morning, afternoon, night, and early morning. The differences of risk during the day were reported as the ratio of morning to afternoon, morning to night and morning to early morning error rates. For the purposes of this research, level 3 events alone were taken into account, since these were the most serious in which company operational limits were exceeded or when established procedures were not followed. According to airline flight schedules, 35% of flights take place in the morning period, 32% in the afternoon, 26% at night, and 7% in the early morning. Data showed that the risk of errors increased by almost 50% in the early morning relative to the morning period (ratio of 1:1.46). For the period of the afternoon, the ratio was 1:1.04 and for the night a ratio of 1:1.05 was found. These results showed that the period of the early morning represented a greater risk of attention problems and fatigue.

Relationship between work rate and oxygen uptake in mitochondrial myopathy during ramp-incremental exercise

We determined the response characteristics and functional correlates of the dynamic relationship between the rate (Δ) of oxygen consumption ( O2) and the applied power output (work rate = WR) during ramp-incremental exercise in patients with mitochondrial myopathy (MM). Fourteen patients (7 males, age 35.4 ± 10.8 years) with biopsy-proven MM and 10 sedentary controls (6 males, age 29.0 ± 7.8 years) took a ramp-incremental cycle ergometer test for the determination of the O2 on-exercise mean response time (MRT) and the gas exchange threshold (GET). The ΔO2/ΔWR slope was calculated up to GET (S1), above GET (S2) and over the entire linear portion of the response (S T). Knee muscle endurance was measured by isokinetic dynamometry. As expected, peak O2 and muscle performance were lower in patients than controls (P < 0.05). Patients had significantly lower ΔO2/ΔWR than controls, especially the S2 component (6.8 ± 1.5 vs 10.3 ± 0.6 mL·min-1·W-1, respectively; P < 0.001). There were significant relationships between ΔO2/ΔWR (S T) and muscle endurance, MRT-O2, GET and peak O2 in MM patients (P < 0.05). In fact, all patients with ΔO2/ΔWR below 8 mL·min-1·W-1 had severely reduced peak O2 values (<60% predicted). Moreover, patients with higher cardiopulmonary stresses during exercise (e.g., higher Δ ventilation/carbon dioxide output and Δ heart rate/ΔO2) had lower ΔO2/ΔWR (P < 0.05). In conclusion, a readily available, effort-independent index of aerobic dysfunction during dynamic exercise (ΔO2/ΔWR) is typically reduced in patients with MM, being related to increased functional impairment and higher cardiopulmonary stress.

Relationship between genetic mutation variations and acute-phase reactants in the attack-free period of children diagnosed with familial Mediterranean fever

Familial Mediterranean fever (FMF) is a periodic autoinflammatory disease characterized by chronic inflammation. This study investigated the relationship between acute-phase reactants and gene mutations in attack-free periods of childhood FMF. Patients diagnosed with FMF were divided into four groups based on genetic features: no mutation, homozygous, heterozygous, and compound heterozygous. These groups were monitored for 2 years, and blood samples were collected every 6 months during attack-free periods. Erythrocyte sedimentation rate, C-reactive protein, fibrinogen, and white blood cell count were measured. A disease severity score was determined for each patient. Mean values for erythrocyte sedimentation rate and fibrinogen were significantly different in the homozygous group. White blood cell count and C-reactive protein were similar between the groups. Disease severity score was higher in patients with the M694V mutation than in individuals without the mutation, as well as in those with other mutation groups. Periodic follow-up of patients with FMF MEFV mutations in subjects with acute-phase reactants may be useful in the prevention of morbidity.

Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China

Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM2.5) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), the FEV1/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM2.5 was also measured in all residences. There was a significant increase in the relative concentration of PM2.5 in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV1, a 7.46% decrease in the FEV1/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV1, and an 8 L/s decrease in PEFR per count per minute of PM2.5 exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke.

Relationship between deep venous thrombosis and inflammatory cytokines in postoperative patients with malignant abdominal tumors

Deep venous thrombosis (DVT) is a common surgical complication in cancer patients and evidence that inflammation plays a role in the occurrence of DVT is increasing. We studied a population of cancer patients with abdominal malignancies with the aim of investigating whether the levels of circulating inflammatory cytokines were associated with postoperative DVT, and to determine the levels in DVT diagnoses. The serum levels of C-reactive protein (CRP), interleukins (IL)-6 and IL-10, nuclear transcription factor-κB (NF-κB) and E-selectin (E-Sel) were determined in 120 individuals, who were divided into 3 groups: healthy controls, patients with and patients without DVT after surgery for an abdominal malignancy. Data were analyzed by ANOVA, Dunnet's T3 test, chi-square test, and univariate and multivariate logistic regression as needed. The CRP, IL-6, NF-κB, and E-Sel levels in patients with DVT were significantly higher than those in the other groups (P<0.05). The IL-10 level was higher in patients with DVT than in controls but lower than in patients without DVT. Univariate analysis revealed that CRP, IL-6, NF-κB, and E-Sel were statistically associated with the risk of DVT (OR=1.98, P=0.002; OR=1.17, P=0.000; OR=1.03, P=0.042; and OR=1.38, P=0.003; respectively), whereas IL-10 had a protective effect (OR=0.94, P=0.011). Multivariate analysis showed that E-Sel was an independent risk factor (OR=1.41, P=0.000). Thus, this study indicated that an increased serum level of E-Sel was associated with increased DVT risk in postoperative patients with abdominal malignancy, indicating that E-Sel may be a useful predictor of diagnosis of DVT.

Relationship between salt consumption measured by 24-h urine collection and blood pressure in the adult population of Vitória (Brazil)

High salt intake is related to an increase in blood pressure and development of hypertension. However, currently, there are no national representative data in Brazil using the gold standard method of 24-h urine collection to measure sodium consumption. This study aimed to determine salt intake based on 24-h urine collection in a sample of 272 adults of both genders and to correlate it with blood pressure levels. We used a rigorous protocol to assure an empty bladder prior to initiating urine collection. We excluded subjects with a urine volume <500 mL, collection period outside of an interval of 23-25 h, and subjects with creatinine excretion that was not within the range of 14.4-33.6 mg/kg (men) and 10.8-25.2 mg/kg (women). The mean salt intake was 10.4±4.1 g/day (d), and 94% of the participants (98% of men and 90% of women) ingested more than the recommended level of 5 g/d. We found a positive association between salt and body mass index (BMI) categories, as well as with salt and blood pressure, independent of age and BMI. The difference in systolic blood pressure reached 13 mmHg between subjects consuming less than 6 g/d of salt and those ingesting more than 18 g/d. Subjects with hypertension had a higher estimated salt intake than normotensive subjects (11.4±5.0 vs 9.8±3.6 g/d, P<0.01), regardless of whether they were under treatment. Our data indicate the need for interventions to reduce sodium intake, as well the need for ongoing, appropriate monitoring of salt consumption in the general population.

The Impact of the 2007-2009 Financial Crisis on the Relationship between Central Bank Rates and the Corresponding Interbank Interest Rates in 2002-2014

The role of central banks throughout the global financial system has become even more important during and after the events of the financial crisis. In order to stabilize the market conditions and provide solid ground for future development, the central banks use discount rate as their primary monetary policy tool in many developed and emerging economies. The purpose of this thesis is to examine how the relationship between central bank rates and corresponding interbank rates has developed before, during and after the crisis period of 2007-2009 in five developed countries and five emerging market countries. The results indicate that during the before-crisis period the interest rate markets reacted diversely but the joint recovery attempts of global economies seem to have stabilized the reactions during and especially after the crisis. The crisis also seems to have highlighted the characteristics of each country’s survival strategy as the role of other policy instruments arose.

Relationship between the price of fish and its quality attributes: a study within a community at the University of São Paulo, Brazil

The aim of this study was to evaluate the associations between the products' market price and attributes related to fish purchase and consumption within a university community in Brazil. A structured questionnaire consisting of a five-point Likert scale was used. It was previously tested and made available to the university community via the Internet. The sample comprised 1966 voluntaries including university students and faculty and staff members. A descriptive analysis of data was performed using Spearman's correlation analysis. The results showed that the majority of the respondents (56%) consume fish at home; some consume fish at restaurants (39%), and 5% at family or friends' houses, reinforcing the idea that variables such as culture and reference groups are fundamental determinants of purchase and consumption behavior. It was identified a significant (p < 0.001) and very strong correlation between the attributes price and nutritional value (r = 0.92); price and availability at the usual places of purchase (r = 0.92); price and packaging (r = 0.92); price and brand name (r = 0.91); and price and of the Federal Inspection stamp (r = 0.91) and a low positive correlation (p < 0.001) between the price variable and the initiative for fish traceability (r = 0.16). This study demonstrated that the price of fish is associated with the quality of the product and the attributes related to it such as packaging, nutritional value, and availability of the product in the market.

Relationship between eggplant seed morphology and germination

Structural differences such as abnormalities, damage and free spaces in seeds may affect germination. The aim of this study was to study the relationship between eggplant seed morphology and seed germination. Ten seed lots of the eggplant cultivar Embu were evaluated by X-ray image analysis and the germination test. Seed image analysis was performed by Image Pro Plus® software and the whole seed area and free space between the embryo and endosperm were measured. The internal seed area filled by the embryo and endosperm was calculated from the difference between the whole seed and free space areas. Based on these results and visual seed analysis, seeds were classified into three categories and information on germination was obtained for each one. X-ray image analysis provides a perfect view of the internal seed parts and for seed morphology studies. An increase in seed area filled by the endosperm and embryo does not improve seed germination. Mechanical seed damage and deteriorated tissues can adversely affect seed germination.

The Dynamic Relationship between Finnish Stock Market and Commodities

Since different stock markets have become more integrated during 2000s, investors need new asset classes in order to gain diversification benefits. Commodities have become popular to invest in and thus it is important to examine whether the investors should use commodities as a part for portfolio diversification. This master’s thesis examines the dynamic relationship between Finnish stock market and commodities. The methodology is based on Vector Autoregressive models (VAR). The long-run relationship between Finnish stock market and commodities is examined with Johansen cointegration while short-run relationship is examined with VAR models and Granger causality test. In addition, impulse response test and forecast error variance decomposition are employed to strengthen the results of short-run relationship. The dynamic relationships might change under different market conditions. Thus, the sample period is divided into two sub-samples in order to reveal whether the dynamic relationship varies under different market conditions. The results show that Finnish stock market has stable long-run relationship with industrial metals, indicating that there would not be diversification benefits among the industrial metals. The long-run relationship between Finnish stock market and energy commodities is not as stable as the long-run relationship between Finnish stock market and industrial metals. Long-run relationship was found in the full sample period and first sub-sample which indicate less room for diversification. However, the long-run relationship disappeared in the second sub-sample which indicates diversification benefits. Long-run relationship between Finnish stock market and agricultural commodities was not found in the full sample period which indicates diversification benefits between the variables. However, long-run relationship was found from both sub-samples. The best diversification benefits would be achieved if investor invested in precious metals. No long-run relationship was found from either sample. In the full sample period OMX Helsinki had short-run relationship with most of the energy commodities and industrial metals and the causality was mostly running from equities to commodities. During the first sub period the number of short-run relationships and causality shrunk but during the crisis period the number of short-run relationships and causality increased. The most notable result found was unidirectional causality from gold to OMX Helsinki during the crisis period.

Rethinking "energy nationalism": a study of the relationship between nation states and companies in the oil industry

ABSTRACTThe term "energy nationalism" is frequently used by academic literature and media, but usually without adequate conceptual accuracy. Despite this, a set of papers deepens the discussion on the relationship between nation states and the energy industry, especially the oil sector. These papers allow identifying fundamental elements to understand the energy nationalism, either complementary or divergent between each other. Thus, this study aims at presenting an interpretation of the concept that fills the gaps left by the above mentioned literature based on a global analysis of the oil industry structure and its historical evolution since the mid-19thcentury.