Assessing the Benefits of Performance-Based Navigation Procedures

Performance-based Navigation (PBN) allows aviation operations to be conducted based on actual operational requirements rather than the requirements of ground-based equipment. Although the general operational benefits of PBN procedures have been recognized by various studies, there is a need to specify the actual benefits in terms of the frequency of event anomalies that could be expected from the use of PBN procedures. The study reviewed some of the available literature and identified some operational improvements as reported by previous authors. The study then proceeded to review archival data from the Aviation Safety Reporting System (ASRS) database with a view to identifying the link between the use of PBN procedures and reported event anomalies. Overall, there were significantly fewer reported event anomalies when PBN procedures were used than when PBN procedures were not used. It is suggested that air operators and air navigation service providers conduct appropriate risk and safety assessments in their consideration of an increased use of PBN procedures

Assessment of Small Unmanned Aerial Systems Operations in the National Airspace System

The operation of small unmanned aerial systems (sUAS) in the National Airspace System requires a careful consideration of the operating philosophies to ensure a safe outcome for all users. Small UAS operations are explored while the associated risks and benefits from the operations are reviewed. The operation of sUAS in self-separation airspace is discussed by an examination of the concept of autonomous flight rules (AFR). This includes a presentation of the basic principles of AFR and an explanation of the requirement for a sense-and-avoid system. Current and future uses of sUAS are presented to highlight the benefits from their use. Finally, an overview of the major risks associated with the operation of sUAS is provided in the form of a risk assessment matrix and a hazard/risk process decision chart. Mitigation actions to reduce the risks are also specified along with recommendations for further study

Radio-protective Potentials of Methanolic/Aqueous Extract of Adasonia digitata and Cochorous olitorious Leaf Plant on Gamma Irradiated Male Wistar Rats

It is no longer news that technology is eating deep as a cankerworm in the heart of human and it is pertinent to know that 90% of the world-used technological gadget are fully equipped with radiation emitting software, which upon human exposure to, generating free radicals-induce disease and several disorders such as hemorrhage induced anaemia, cancer, ischemia reperfusion diseases, diabetes, atherosclerosis and several others (Haliwell, 2000). Hence the needs to prevent, ameliorate, attenuate and cure the effects of radiation generating disorders. Some groups of rat were exposed to gamma radiation of 6Grey, generating free radicals and inducing several diseases and disorders. A. digitata and C.olitorious has been established to poses significant (p<0.05) amounts of antioxidant phytochemicals (inducers of endogenous antioxidant enzymes) such as Saponin(16.59±1.85 and 22.12±0.24),Tannins(311.98±0.01 and 287.07±0.16), Polyphenols(170.90±0.68 and 330.07±0.32),Alkaloids(81.56±0.56 and 68.65±2.05) and flavonoids(25.38±2.88 and 157.38±0.38) which is suggestive of the free radical scavenging potentials of the two plants extracts. The administration of the plant extract to rats exposed to radiation was able to attenuate and prevent the disorders, implicating the plant extracts to be radioprotective and antioxidative in potentials. The safety evaluation analysis was examined by measuring the serum ALT, AST and ALP level which was not significantly (p<0.05) different when compared to the normal control, establishing the Hepatoprotective potential of the plant extracts. Keywords: Antioxidative, ameliorate, Free Radicals, Radiation, Hepatoprotective, Radioprotectiv

Salmonellosis in Lagos, Nigeria: Incidence of Plasmodium falciparum-associated Co-infection, Patterns of Antimicrobial Resistance, and Emergence of Reduced Susceptibility to Fluoroquinolones

The present study was undertaken to examine the status of antimicrobial resistance in Salmonella-associated diseases, by verifying possible emergence of reduced susceptibility to fluoroquinolones in Salmonella isolates and determining the incidence of Plasmodium falciparum-associated co-infection with Salmonella serotypes. Antimicrobial resistance in clinical isolates of Salmonellae was examined for a 12-month period. Four hundred and forty-one patients comprising two groups were recruited. Group A comprised 235 patients diagnosed by clinicians of having pyrexia, and group B included stool samples of 206 patients presenting with gastroenteritis. Samples were cultured and isolates identified, and drug susceptibility testing was performed using the standard methods. Of the 235 samples screened in group A, 42 Salmonella isolates and 107 Plasmodium spp. were identified. Of the 42 Salmonella isolates, 19 (45.2%) were Salmonella Typhi, 9 (21.4%) S. Enteritidis, and 7 (16.7%) each of S. Paratyphi and S. Arizonae. Plasmodium spp.-associated co-infection with Salmonellae was observed in 16 patients mostly in complicated typhoidal cases and S. Enteritidis-associated bacteraemia. Fiftty-three of the 206 stool samples from group B patients were confirmed positive for bacterial pathogens, made up of 35 Salmonella and 18 Shigella isolates. Of the Salmonella isolates, 18 (51.4%) were S. Enteritidis, 11 (31.4%) S. Arizonae, 4 (11.4%) S. Paratyphi, and 2 (5.7%) S. Typhi. There was no statistically significant difference (p<0.01) in antimicrobial resistance patterns exhibited among typhoidal Salmonellae isolated in 2000 and 2005. A similar trend in resistance was recorded for non-typhoidal Salmonellae (p<0.05). For the first time in Lagos, Nigeria, Salmonella isolates (10–18%) with reduced susceptibility to both ciprofloxacin and ofloxacin at MIC50 and MIC90 values of 0.015 and 0.03 μg/mL respectively were found. Despite this development, ciprofloxacin and ofloxacin remain the drug of choice for severe cases of salmonellosis, although caution should be exercised by clinicians in their pres-criptions such that fluoroquinolone antibiotic therapy is used only in laboratory-proven cases of typhoid fever and Salmonella-associated bacteraemia to preserve its efficacy

The market\u27s evaluation of off-balance sheet banking risk: a methodological reexamination

The empirical literature, to date, has ignored the impact of Off-balance sheet (OBS) banking activities on the default-risk premia borne by bank subordinated debtholders. This paper examines the market discipline of OBS activities by employing a contingent claims pricing model to the default-risk premia on subordinated debt. The standard approach to determine if market prices of subordinated debt reflect the risk of default is to regress the yield spread against accounting measures of bank risk. This approach is inadequate because yield spreads are neither linear nor monotonic functions of bank risk. Moreover, this approach fails to account for the fact that banks are regulated. Observed yields on subordinated bank debt over equivalent maturity treasuries are used to compute implied asset variances. OBS banking activities appear to reduce both linear risk-premia and implied asset variances. These results suggest that bank regulators are overly concerned with the risk exposure of OBS activities. The risk-based capital requirement of OBS banking activities may be inappropriate

The market\u27s evaluation of off-balance sheet banking risk: a methodological reexamination

The empirical literature, to date, has ignored the impact of Off-balance sheet (OBS) banking activities on the default-risk premia borne by bank subordinated debtholders. This paper examines the market discipline of OBS activities by employing a contingent claims pricing model to the default-risk premia on subordinated debt. The standard approach to determine if market prices of subordinated debt reflect the risk of default is to regress the yield spread against accounting measures of bank risk. This approach is inadequate because yield spreads are neither linear nor monotonic functions of bank risk. Moreover, this approach fails to account for the fact that banks are regulated. Observed yields on subordinated bank debt over equivalent maturity treasuries are used to compute implied asset variances. OBS banking activities appear to reduce both linear risk-premia and implied asset variances. These results suggest that bank regulators are overly concerned with the risk exposure of OBS activities. The risk-based capital requirement of OBS banking activities may be inappropriate

Deposit insurance, market discipline and off-balance sheet banking risk of large U.S. commercial banks

The market discipline of off-balance sheet banking activities (OBSA) has been reexamined by employing contingent claims valuation techniques to derive implied asset variances from bank equity and deposit insurance, and from risk-premia for bank subordinated debt. Specifically implied asset variances have been calculated from contingent valuation models and have been regressed over on-balance accounting risk variables and off-balance sheet activities. These implied asset variances are better than equity variance or risk-premia in proxying total risk because they consider both the non-linear nature of contingent claims model and the impact of closure rules. Empirical results document the existence of market discipline of some OBSA. Market participants price these OBSA as risk-reducing. Therefore, regulatory additional capital requirements of such OBS may be inappropriate

Classification-based data mining for identification of risk patterns associated with hypertension in Middle Eastern population A 12-year longitudinal study

Hypertension is a critical public health concern worldwide. Identification of risk factors using traditional multivariable models has been a field of active research. The present study was undertaken to identify risk patterns associated with hypertension incidence using data mining methods in a cohort of Iranian adult population. Data on 6205 participants (44 men) age > 20 years, free from hypertension at baseline with no history of cardiovascular disease, were used to develop a series of prediction models by 3 types of decision tree (DT) algorithms. The performances of all classifiers were evaluated on the testing data set. The Quick Unbiased Efficient Statistical Tree algorithm among men and women and Classification and Regression Tree among the total population had the best performance. The C-statistic and sensitivity for the prediction models were (0.70 and 71) in men, (0.79 and 71) in women, and (0.78 and 72) in total population, respectively. In DT models, systolic blood pressure (SBP), diastolic blood pressure, age, and waist circumference significantly contributed to the risk of incident hypertension in both genders and total population, wrist circumference and 2-h postchallenge plasma glucose among women and fasting plasma glucose among men. In men, the highest hypertension risk was seen in those with SBP > 115mm Hg and age > 30 years. In women those with SBP > 114 mmHg and age>33 years had the highest risk for hypertension. For the total population, higher risk was observed in those with SBP > 114mm Hg and age > 38 years. Our study emphasizes the utility of DTs for prediction of hypertension and exploring interaction between predictors. DT models used the easily available variables to identify homogeneous subgroups with different risk pattern for the hypertension. Copyright © 2016 the Author(s). Published by Wolters Kluwer Health, Inc. All

Hedging potentials of green investments against climate and oil market risks

Purpose: This study examines the ability of clean energy stocks to provide cover for investors against market risks related to climate change and disturbances in the oil market.Design/methodology/approach: The study adopts the Feasible Quasi Generalized Least Squares technique to estimate a predictive model based on Westerlund and Narayan’s (2015) approach to evaluating the hedging effectiveness of clean energy stocks. The out-of-sample forecast evaluations of the oil risk-based and climate risk-based clean energy predictive models are explored using Clark and West’s model (2007) and a modified Diebold & Mariano forecast evaluation test (Harvey et al., 1997) for nested and non-nested models respectively.Findings: The study finds ample evidence that clean energy stocks may hedge against oil market risks. This result is robust to alternative measures of oil risk and holds when applied to data from the COVID-19 pandemic. In contrast, the hedging effectiveness of clean energy against climate risks is limited to 4 of the 6 clean energy indices and restricted to climate risk measured with Climate Policy Uncertainty.Originality/value: The study contributes to the literature by providing extensive analysis of hedging effectiveness of several clean energy indices (global, US, Europe, and Asia) and sectoral clean energy indices (solar and wind) against oil market and climate risks using various measures of oil risk (WTI and Brent volatility) and climate risk (Climate Policy Uncertainty and Energy and Environmental Regulation) as predictors. It also conducts forecast evaluations of the clean energy predictive models for nested and non-nested models

Measuring the Economic Benefits of Forests in Relation to Households’ Welfare and Forest Dependence in South-western Nigeria

The study assesses the contributions of forest resources income on poverty among rural households in South-western Nigeria. A multi-stage random sampling approach was adopted while descriptive analysis and [Foster-Greer-Thorbecke (FGT 1984) poverty index] were used. Poverty index results showed that 68 percent of the rural households were living below the poverty line in the region. Disaggregated to state level, the highest proportion was found in Osun state (77 percent ), followed by Ogun state (70 percent ) and Oyo state with about 50 percent. The minimum cost required to bring those poor households to the poverty line (that is, to eliminate poverty) across states include: N4, 553, N9, 664 and N8918 in Oyo, Osun and Ogun states respectively. This indicates that poverty is more severe in Osun state followed by Oyo state but less severe in Ogun state. Also, forest income has tendency to stem the tide of poverty in the region. Therefore, Government and authority concerned should increase opportunities for entrepreneurship and employment in forestry while avoiding deforestation and forest degradation