Access to Water in the Slums of Sub‐Saharan Africa

This article reviews the changing perspectives for improving access to water in the slums of developing countries, especially in sub‐Saharan Africa. While much of the literature continues to maintain an aversion to state‐led urban development policies, there is now increasing emphasis on the importance of informal, small‐scale providers and communitarian initiatives, following the many failures of privatisation. The article argues that market‐oriented solutions are inappropriate for sub‐Saharan African countries where over two‐thirds of the urban population live in squatter settlements with multidimensional challenges.     

Assessment of the Regional Economic Impacts of Catastrophic Events: CGE Analysis of Resource Loss and Behavioral Effects of an RDD Attack Scenario

We investigate the regional economic consequences of a hypothetical catastrophic event—attack via radiological dispersal device (RDD)—centered on the downtown Los Angeles area. We distinguish two routes via which such an event might affect regional economic activity: (i) reduction in effective resource supply (the resource loss effect) and (ii) shifts in the perceptions of economic agents (the behavioral effect). The resource loss effect relates to the physical destructiveness of the event, while the behavioral effect relates to changes in fear and risk perception. Both affect the size of the regional economy. RDD detonation causes little capital damage and few casualties, but generates substantial short‐run resource loss via business interruption. Changes in fear and risk perception increase the supply cost of resources to the affected region, while simultaneously reducing demand for goods produced in the region. We use results from a nationwide survey, tailored to our RDD scenario, to inform our model values for behavioral effects. Survey results, supplemented by findings from previous research on stigmatized asset values, suggest that in the region affected by the RDD, households may require higher wages, investors may require higher returns, and customers may require price discounts. We show that because behavioral effects may have lingering long‐term deleterious impacts on both the supply‐cost of resources to a region and willingness to pay for regional output, they can generate changes in regional gross domestic product (GDP) much greater than those generated by resource loss effects. Implications for policies that have the potential to mitigate these effects are discussed.     

Goodness of fit tests for Nakagami distribution based on smooth tests

ABSTRACT

Nakagami distribution is one of the most common distributions used to model positive valued and right skewed data. In this study, we interest goodness of fit problem for Nakagami distribution. Thus, we propose smooth tests for Nakagami distribution based on orthonormal functions. We also compare these tests with some classical goodness of fit tests such as Cramer–von Mises, Anderson–Darling, and Kolmogorov–Smirnov tests in respect to type-I error rates and powers of tests. Simulation study indicates that smooth tests give better results than these classical tests give in respect to almost all cases considered.     

Structural constraints and excess capacity: an international comparison of manufacturing firms

Excess capacity results in real and opportunity costs as well as lower factor productivity. Conventionally, variation in capacity utilisation rates has been explained with reference to the business cycles and market imperfections. In this article, we show that these two factors do not always fully explain the causes of idle capacity. Our findings suggest that manufacturing firms in low‐income countries tend to have lower capacity utilisation (CU) rates than those in middle‐ and upper‐middle‐income groups. To explain this peculiarity, it is proposed in this article that the level of excess capacity partly depends on supply‐side conditions and institutional variables. The findings provide strong support for this view and suggest that there are gains to be made in the manufacturing industries of the lower‐income countries through improvements in the structural conditions.     

Effect of age and physical activity level on functional fitness in older adults

It is difficult to distinguish between the effects of age and physical activity level in the functional fitness level of older adults. The objective of this study was to determine the effects of age and physical activity level on some functional fitness parameters in community-dwelling older adults.Two hundred twenty-nine elderly (111 female; 118 male) aged between 65–87 years living in the Balçova municipality region were divided into two groups: the young elderly (65–69 years old) and the elderly (70 years old or over). The “seven-day physical activity recall questionnaire” was used to estimate physical activity level (PAL). The functional fitness evaluation included the body mass index (BMI), the lower body strength (LBS), the dynamic balance, and the aerobic endurance. The young elderly were significantly worse with regard to BMI and significantly better with regard to LBS, dynamic balance, and aerobic endurance than the elderly; in contrast, PAL did not affect any of the functional fitness parameters. The young elderly showed worse BMI than the elderly when the age groups were less active. The young elderly showed better LBS and dynamic balance than the elderly when the age groups were more active. The young elderly showed significantly better aerobic endurance than the elderly in both the less and more active age groups. This study confirms that age affects functional fitness, whereas PAL generally does not. However, being more active is advantageous for the young elderly with regard to BMI, LBS, and dynamic balance.     

Permutation approach for ordinal preference data

Best et al. (Best, D. J., Rayner, J. C. W., O'Sullivan, M. G. (2000 Best, D. J., Rayner, J. C. W., O'Sullivan, M. G. (2000). Product maps for consumer categorical data. Food Quality and Preference 11:91–97.[Crossref], [Web of Science ®] , [Google Scholar]). Product maps for consumer categorical data. Food Quality and Preference, 11:91–97) suggested tests based on partitioning the X² statistic into relevant components of location, dispersion, and skewness effects for testing equality of each effect for ordinal preference data. It is known that the chi-square approximation requires large counts for categories. For this purpose, in this study, we investigate a permutation approach for these statistics and compare the performance of these tests with simulation study. In addition, the permutation approach can be used to produce a product map that classifies the products. We illustrate the approach with a real data example.     

Ratio estimator for the population mean using ranked set sampling

We adapt the ratio estimation using ranked set sampling, suggested by Samawi and Muttlak (Biometr J 38:753–764, 1996), to the ratio estimator for the population mean, based on Prasad (Commun Stat Theory Methods 18:379–392, 1989), in simple random sampling. Theoretically, we show that the proposed ratio estimator for the population mean is more efficient than the ratio estimator, in Prasad (1989), in all conditions. In addition, we support this theoretical result with the aid of a numerical example.      

Improvement in Estimating the Population Median in Simple Random Sampling and Stratified Random Sampling Using Auxiliary Information

This paper deals with estimation of population median in simple and stratified random samplings by using auxiliary information. Auxiliary information is rarely used in estimating population median, although there have been many studies to estimate population mean using auxiliary information. In this study, we suggest some estimators using auxiliary information such as mode and range of an auxiliary variable and correlation coefficient. We also expand these estimators to stratified random sampling for combined and separate estimators. We obtain mean square error equations for all proposed estimators and find theoretical conditions. These conditions are also supported by using numerical examples.     

Decisions under risk: Dispersion and skewness

Journal of Risk and Uncertainty - For centuries, scholars have examined what motivates prosocial behavior. In the U.S., prosocial behavior is routinely accompanied by thoughts and prayers. Yet, the...     

No association of serum PSA with vitamin D or total oxidant-antioxidant capacity in healthy men

Background and aim: Vitamin D deficiency and oxidative stress were suggested to be related to prostate cancer risk. We aimed to investigate the association of serum PSA concentration with vitamin D and total oxidant/antioxidant levels.

Materials and methods: A total of 95 healthy men were enrolled for the cross sectional study. Serum PSA, 25(OH)D, serum total oxidant status, and total antioxidant status were measured.

Results: Serum PSA was significantly negatively correlated with serum total oxidant status (r=??0.309, p?=?.003) but there was no significant correlation between PSA and 25(OH)D (p?=?.383) or total antioxidant levels (p?=?.233). After adjustment for age BMI and smoking status with multiple regression analysis, there was no significant association between serum PSA and total oxidant status.

Conclusion: We find no evidence for an association between PSA and vitamin D levels or serum total oxidant/antioxidant levels.