Model Uncertainty in Characterizing Recreation Demand

A Bayesian variable selection procedure is used to control for uncertainty in the specification of a recreational demand model. Specifically, we propose a model that draws on the Bayesian paradigm to integrate the variable selection process into the model and reflect the accompanying uncertainty about which is the “best†specification used for counterfactual predictions. The advantage of this procedure over previous non-Bayesian approaches is that overcomes the problem of pre-testing in specification searches.

Quality of environmental disclosure by multi-national oil companies: a corporate governance perspective

Over the past few years, concern about the issue of environmental sustainability has increased considerably. Closely linked to this concern is the growing disquiet over the increasing pervasiveness of multi-national companies, especially oil companies, in shaping global politics and economics. Consequently, increased awareness about the environment has led to calls for better management of global resources and for ways in which to make the corporations that benefit the most from the exploitation of these resources, more socially accountable and environmentally responsible. The oil industry continues to be at the centre of this debate. Despite the industry’s immense contributions to society, it is regarded as a multi-national company with a questionable record of environmental sustainability practices and a low level of accountability and transparency. In an attempt to respond to these criticisms, oil companies are now producing corporate social responsibility (CSR) reports; voluntary reports containing disclosure about their social and environmental sustainability activities. Against a theoretical background in which reasons were adduced to explain the motivation for the voluntary corporate disclosure phenomenon and a discussion of the oil industry’s pivotal role in the environmental sustainability debate, this dissertation evaluated the quality of the environmental CSR disclosure contained in the annual report of thirty- four multinational oil companies. The evaluation was benchmarked against the environmental reporting requirements of the Global Reporting Initiative (GRI), the only internationally recognised CSR reporting standards. In addition, using regression analysis, this dissertation considered the impact of selected corporate characteristics on the quality of individual corporate environmental report. Finally, the dissertation looked at the corporate governance implications of the quality of the industry’s environmental reporting

Controlling for Observed and Unobserved Site Characteristics in Rum Models of Recreation Demand

�Random Utility Maximization (RUM) models of recreation demand are typically plagued by limited information on environmental and other attributes characterizing the available sites in the choice set. To the extent that these unobserved site attributes are correlated with the observed characteristics and/or the key travel cost variable, the resulting parameter estimates and subsequent welfare calculations are likely to be biased. In this paper we develop a Bayesian approach to estimating a RUM model that incorporates a full set of alternative specific constants, insulating the key travel cost parameter from the influence of the unobserved site attributes. In contrast to estimation procedures recently outlined in Murdock (2006), the posterior simulator we propose (combining data augmentation and Gibbs sampling techniques) can be used in the more general mixed logit framework in which some parameters of the conditional utility function are random. Following a series of generated data experiments to illustrate the performance of the simulator, we apply the estimation procedures to data from the Iowa Lakes Project. In contrast to an earlier study using the same data (Egan \textit{et al.} \cite{eganetal}), we find that, with the addition of a full set of alternative specific constants, water quality attributes no longer appear to influence the choice of where to recreate.nonmarket valuation; water quality; discrete choice

Clinical Features and Pattern of Presentation of Breast Diseases in Surgical Outpatient Clinic of a Suburban Tertiary Hospital in South-West Nigeria

Objective: To characterize the clinical features and pattern of presentation of breast diseases as observed in our practice. Materials and Methods: A prospective study of 121 consecutive patients with breast complaints presenting in our Surgical Outpatient Clinics. The relevant data were collected by two surgeons using the prescribed forms and was analyzed using Epi Info 2003, Mann–Whitney (test of two groups) Chi-squared and Fishers exact test was used to compare parameters of benign and malignant groups. P value <0.05 was considered as significant. Results: One hundred and nineteen patients were females, two were males. The age range was 14–70 years. Forty two (34.7%) patients were in the 21–30 year age group. The commonest symptoms were breast lump in 111 (91.7%) patients, and breast pain in 28 (23.1%) patients. Breast pain was a significant presenting complaint in patients with breast malignancy (P=.026). On clinical examination 103 (85.1%) patients had palpable lumps, and seven patients were normal. Forty four patients (36.3%) had malignant disease, seventy patients (57.8%) had benign breast diseases and seven were normal. Fifty nine of the 70 benign diseases were fibroadenoma. One hundred and three patients (85%) had appropriate therapy, while 18 patients (14.8%), including eight with malignant disease absconded. Conclusion: In the study, a breast lump was the commonest clinical feature of breast disease. Over 60% of these were benign. Breast pain was a statistically significant presentation in patients with malignant breast disease. One in seven of the patients absconded.Keywords: Breast lumps, breast malignancy, breast pain, fibroadenomaNigerian Journal of Surgery, Jan-Jun 2012 | Volume 18 | Issue

Evaluation of the feeding efficiency of three systems in feeding large roll hay packages

This experiment dealt with three systems for feeding large round hay packages to beef animals and with animal performance (weight gain) associated with outside-stored and inside-stored large round bales of bermudagrass hay. Feeding trials were conducted at the end of a four-month storage period to determine the amount of hay refused and tramped into the mud by cattle. The amount of hay wasted during the feeding trials was used to determine the cost-benefit ratio for each type of feeding equipment. Results indicated that larger amounts of hay were wasted from the panel feeder than from the roofed or unroofed feeder (17 percent, 7 percent and 9 percent dry matter loss respectively). Cattle fed inside stored hay performed better (gained more weight per day) than cattle fed outside-stored hay. Based on the data collected from this study, hay saved by the roofed feeder did not justify the cost of using the roofed bunk for bermudagrass hay (at $46/ton, annual value of hay saved amounted to$74 compared to an annual cost for the roofed feeder above that of the panel of $108. Annual value of hay saved by the unroofed feeder amounted to$59 compared to an annual cost for the unroofed feeder above that of the panel of $64)

Predicting the Determinants of Homicides Rates Across the ECOWAS Region, 1960-2020

The purpose of this study was to predict the determinants of homicide crime across the ECOWAS region. The study used a correctional research design, with a sample size of 15 across the period ranging from 1960 to 2020. The study used a criterion variable of homicide rates, and the predictor variables to include development indicator-life expectancy at birth, economic inequality, youth unemployment, and sex-ratio. The study used SPSS to process and analyze the dataset which came from the following agencies: WHO, World Bank, UNDP, etc. The study used Ordinary Least Squared analysis to predict the determinants of high homicides rates across the ECOWAS region. The study finds the following: a weak inverse relationship between the life expectancy at birth and homicide (r = –0.317**) which is significant at 5% significance, moderately strong positive relationship between economic inequality and homicide (r = 0.657**) and a moderately strong inverse relationship between economic inequality and development (r = –0.548**). Also, the study finds a weak negative association between homicide and sex-ratio (-0.287*). While unemployment exhibited a strong positive significant associated with homicide (r=0.795). Above all the study finds that about 76.5% variations in the homicide crime could be attributed to the following variables, such as life expectancy at birth or the level of development, economic inequality, youth unemployment, and sex ratio. Keywords: Homicide, Crime, ECOWAS, Unemployment, Inequality, Development, Life Expectancy, Gini-Index DOI: 10.7176/DCS/12-7-02 Publication date:September 30th 202

Concurrent Phosphorus Recovery and Energy Generation in Mediator-Less Dual Chamber Microbial Fuel Cells: Mechanisms and Influencing Factors

This study investigated the mechanism and key factors influencing concurrent phosphorus (P) recovery and energy generation in microbial fuel cells (MFC) during wastewater treatment. Using a mediator-less dual chamber microbial fuel cell operated for 120 days; P was shown to precipitate as struvite when ammonium and magnesium chloride solutions were added to the cathode chamber. Monitoring data for chemical oxygen demand (COD), pH, oxidation reduction potential (ORP) and aeration flow rate showed that a maximum 38% P recovery was achieved; and this corresponds to 1.5 g/L, pH > 8, −550 ± 10 mV and 50 mL/min respectively, for COD, pHcathode, ORP and cathode aeration flow rate. More importantly, COD and aeration flow rate were shown to be the key influencing factors for the P recovery and energy generation. Results further show that the maximum P recovery corresponds to 72 mW/m2 power density. However, the energy generated at maximum P recovery was not the optimum; this shows that whilst P recovery and energy generation can be concurrently achieved in a microbial fuel cell, neither can be at the optimal value

Comparative evaluation of processes for production of soybean meal for poultry feed in Nigeria Evaluación comparativa de procesos para la producción de harina de soya para la alimentación de pollos en Nigeria

This work examined and compared three processes for production of low trypsin inhibitor soybean meal. Soybean flour was subjected to roasting, autoclaving and steaming to denature trypsin inhibitors. Roasting was done at 120, 130, 135 and 140 ºC for 5, 7, 8 and 9 minutes, respectively. Autoclaving was carried out at 121ºC, 15psig for 20, 30, 40 and 50 minutes. Steaming was carried out at 105 ºC for 10, 12, 15 and 18 minutes. Defatting of the samples was done and the activity of trypsin inhibitor was investigated. Proximate analysis and quality tests was carried out to ascertain quality of the heat treated soybean meals. Trypsin inhibitor in the soybean meals from the three heat treatment processes ranged from 1.20 to 3.54mg/g while that of raw sample was 6.01mg/g. Percentage crude protein in all the heat treated samples ranged from 39.38 to 40.58 % while that of raw sample was 44.60 %. Urease index ranged from 0.11 to 2.07 % for all heat treated samples while it was 2.11 % for the raw samples. % KOH protein solubility in Soybean meal from the three processes ranged from 45.2 to 73.1 % while that of the raw sample was 49.1%. The results were statistically significant at p>0.05. At significance level of p>0.05 it was established that local soybeans can be processed with adequate heat to obtain low activity soybean meal with good nutrient standard. The steaming process operated at 105 ºC for 18 minutes gave the best overall results with trypsin inhibitor activity of 1.20 mg/g

Tertiary Enrolment and Economic Growth in Nigeria

Over the years, tertiary enrolment of school-aged children has been quite distorting in spite of government efforts at stimulating school enrolment in Nigeria. It is equally discovered that while tertiary enrolment is nominally increasing, in real terms, it is abysmally nose-diving. Therefore, this paper examined the impact of tertiary enrolment on economic growth in Nigeria between 1980 and 2010. The study utilized the Ordinary Least Square estimation techniques to analyze the empirical model of the study. The findings of the empirical investigation confirm that tertiary enrolment is veritable tools through which appreciable economic growth can be enhanced in Nigeria. The study equally observed that tertiary enrolment exhibit a strong predictive power in explaining variation in economic growth in Nigeria. The paper therefore recommends that there is need for government to adequately and conscientiously fund the education sector in the light of weak and sluggish trend of tertiary enrolment in Nigeria. Effective collaboration between the government and private sector is also considered indispensible for the development of education sector in Nigeria. KEYWORDS: Tertiary enrolment, Economic Growt