EVALUATION OF FINITE MIXTURE MODELS FOR DESCRIBING THE STRUCTURE OF DISTURBED GMELINA STANDS IN OLUWA FOREST RESERVE, NIGERIA

Finite mixture model is relevant for describing diameter distribution that is multimodal or heavily skewed. Irregular diameter distribution is partly caused by forest disturbance such as bush burning and illegal logging. This study evaluated five finite mixture models for describing the irregular diameter distributions of the disturbed Gmelina arborea Roxb stands in Oluwa Forest Reserve, Nigeria. Twenty plots of 0.04 ha size, five each from four stand ages (19, 24, 29 and 34 years) were used in this study. Five finite mixture models: gamma, Gompertz, log-logistic, lognormal and Weibull mixtures were considered. The quality of fits produced by the models were evaluated with five indices: Anderson-Darling, Cramer-von Mises, Kolmogorov-Smirnov, Akaike Information Criterion and Hannan-Quinn Information Criterion. Relative rank sum from the indices was analysed using One-way analysis of variance. The results showed that gamma mixture had the smallest indices and relative rank, but not significantly different from Weibull and log-logistic mixtures (p > 0.05). Lognormal and Gompertz mixtures performed poorly. The order of ranking was: gamma followed by Weibull, log-logistic, lognormal and Gompertz. Application of the mixture models provided good predictions of the forest stand volume

A comparison of the Bering Sea, Gulf of Alaska, and Aleutian Islands large marine ecosystems through food web modeling / by K. Aydin ... [et al.]

Detailed mass balance food web models were constructed to compare ecosystem characteristics for three Alaska regions: the eastern Bering Sea (EBS), the Gulf of Alaska (GOA), and the Aleutian Islands (AI). This paper documents the methods and data used to construct the models and compares ecosystem structure and indicators across models. The common modeling framework, including biomass pool and fishery definitions, resulted in comparable food webs for the three ecosystems which showed that they all have the same apex predator—the Pacific halibut longline fishery. However, despite the similar methods used to construct the models, the data from each system included in the analysis clearly define differences in food web structure which may be important considerations for fishery management in Alaska ecosystems. The results showed that the EBS ecosystem has a much larger benthic influence in its food web than either the GOA or the AI. Conversely, the AI ecosystem has the strongest pelagic influence in its food web relative to the other two systems. The GOA ecosystem appears balanced between benthic and pelagic pathways, but is notable in having a smaller fisheries catch relative to the other two systems, and a high biomass of fish predators above trophic level (TL) 4, arrowtooth flounder and halibut. The patterns visible in aggregated food webs were confirmed in additional more detailed analyses of biomass and consumption in each ecosystem, using both the single species and whole ecosystem indicators developed here

N-Nitrosamines and Nigerian habitual drinks, and cancer

Commercially available samples of Nigerian lager beers and bottled palm wine, and of root cuttings of medicinal plants, assayed for volatile N-nitroso compounds and nitrosatable entities, respectively, by chromatographic, chemiluminescence, colorimetric, derivatisation and nitrosation methods, contained nitrosodimethylamine (0.2–2.3 μg/kg; mean, 0.9 μg/kg

ORGANISATIONAL JUSTICE AND EMPLOYEE COMMITMENT OF SELECTED PRIVATE SECONDARY SCHOOLS TEACHERS IN NIGERIA

This study investigates the relationship between organisational justice and employee commitment of private secondary school teachers in Nigeria using survey design. Twenty (20) private secondary schools were selected in Bayelsa State using simple random sampling. Four hundred and eighty (480) teachers were surveyed. Sample of two hundred and fourteen (214) was determined using Krejcie and Morgan sample size determination table. Two hundred and fourteen (214) copies of questionnaire were administered to the teachers but one hundred and eighty three (183) copies were correctly filled and returned. Pearson Product Moment Correlation Coefficient (rs) was used to analyse the hypotheses. It was found that organisational justice has positive significant association with employee commitment. This study concludes that organisational justice measured in terms of distributive justice, procedural justice and interactional justice enhances employee commitment in selected private secondary schools in Nigeria

A critical appraisal of the legal regime for biodiversity conservation in Nigeria

Nigeria harbours a peculiar and an uncertain environmental situation taking into cognizance the desert encroachment in the North and the rise of sea level leading to flooding in the South, which calls for a well articulated, accelerated, and organized remedial action plan on the conservation of Biodiversity. Several species of fauna and flora which the country is naturally endowed with have been rendered extinct or are in danger of extinction as a consequence of economic growth and development. On the international scene the situation is not better with current trends like climate change which has greatly affected the distribution and extinction of species of flora and fauna, ecosystems as well as man and his environment. The earth surface which is full of a diversity of plants and animals currently estimated at about 1.7 million known species are yet greatly threatened by biodiversity loss, erosion, depletion of genes and global species constitute an important concern to national and international authorities. The objective of this paper is to examine the legal regimes on the conservation of biodiversity at the global level, equally Nigeria as a global player has domesticated these regimes into its national laws in a bid to ensure the conservation of biodiversity within the country. We are also going to examine the causes and effects of the loss of biodiversity, the relationship between biodiversity conservation and the fight against climate change. In this paper, judicial decisions, statutes, international treaties as well as official records on the conservation of biodiversity form the primary sources while secondary sources such as textbooks, journals, official proceedings, specialized publications and conference papers were equally utilized. The paper will be crowned with some recommendations proffered from the writers’ perspective and a conclusion.Key words: Biodiversity; Conservation; Legal regime; Nigeri

Triglycerides and TG/HDL‑C ratio as surrogate markers for insulin resistance in Nigerian women with polycystic ovary syndrome

Background: Dyslipidemia is one of the most perplexing metabolic consequences in polycystic ovary syndrome (PCOS). Obesity, insulin resistance (IR), and hyperandrogenism, the pervasive features of PCOS, play significant pathophysiological roles in the lipidemic aberrations associated with the syndrome.Objective: This study aimed to assess the diagnostic utility of triglyceride (TG) and triglyceride to high‑density lipoprotein‑cholesterol (TG/HDL‑C) ratio as surrogate markers for identifying IR in infertile Nigerian women with PCOS.Materials and Methods: Eighty‑seven infertile women with PCOS were selected according to the Androgen Excess Society criteria and categorized into two groups. After anthropometric measurements, fasting blood samples were assayed for plasma glucose, serum insulin, total cholesterol, TG, HDL‑C while lipoprotein ratios were calculated. Homeostasis model assessment for IR (HOMA‑IR) was used in defining IR. The areas under the receiver operating characteristic (ROC) curve analysis were used to compare the power of the serum markers, and to obtain the optimal cutoffs of TG and TG/HDL‑C with HOMA‑IR.Results: TGs correlated significantly with HOMA‑IR in the obese PCOS women. However, the areas under the ROC of potential markers showed no significant marker for HOMA‑IR. The highest area under the curve of ROC for TG belongs to the obese group with a sensitivity of 56% and specificity of 53% (TG ≥ 92.5mg/dL) as a marker of IR in obese PCOS women.Conclusion: TG and TG/HDL‑C would not be reliable markers of IR, and a concerted approach in finding surrogate markers will benefit future  investigations. Key words: Insulin resistance; Nigerian women; polycystic ovary syndrome; surrogate marker; triglyceride

Knowledge, attitude and practice of Nigerian women towards breast cancer: A cross-sectional study

BACKGROUND: Late presentation of patients at advanced stages when little or no benefit can be derived from any form of therapy is the hallmark of breast cancer in Nigerian women. Recent global cancer statistics indicate rising global incidence of breast cancer and the increase is occurring at a faster rate in populations of the developing countries that hitherto enjoyed low incidence of the disease. Worried by this prevailing situation and with recent data suggesting that health behavior may be influenced by level of awareness about breast cancer, a cross-sectional study was designed to assess the knowledge, attitude and practices of community-dwelling women in Nigeria towards breast cancer. METHODS: One thousand community-dwelling women from a semi-urban neighborhood in Nigeria were recruited for the study in January and February 2000 using interviewer-administered questionnaires designed to elicit sociodemographic information and knowledge, attitude and practices of these women towards breast cancer. Data analysis was carried out using Statistical Analysis Software (SAS) version 8.2. RESULTS: Study participants had poor knowledge of breast cancer. Mean knowledge score was 42.3% and only 214 participants (21.4%) knew that breast cancer presents commonly as a painless breast lump. Practice of breast self examination (BSE) was low; only 432 participants (43.2%) admitted to carrying out the procedure in the past year. Only 91 study participants (9.1%) had clinical breast examination (CBE) in the past year. Women with higher level of education (X(2 )= 80.66, p < 0.0001) and those employed in professional jobs (X(2 )= 47.11, p < 0.0001) were significantly more knowledgeable about breast cancer. Participants with higher level of education were 3.6 times more likely to practice BSE (Odds ratio [OR] = 3.56, 95% Confidence interval [CI] 2.58–4.92). CONCLUSION: The results of this study suggest that community-dwelling women in Nigeria have poor knowledge of breast cancer and minority practice BSE and CBE. In addition, education appears to be the major determinant of level of knowledge and health behavior among the study participants. We recommend the establishment and sustenance of institutional framework and policy guidelines that will enhance adequate and urgent dissemination of information about breast cancer to all women in Nigeria

Mechanism and Health Effects of Heavy Metal Toxicity in Humans

Several heavy metals are found naturally in the earth crust and are exploited for various industrial and economic purposes. Among these heavy metals, a few have direct or indirect impact on the human body. Some of these heavy metals such as copper, cobalt, iron, nickel, magnesium, molybdenum, chromium, selenium, manganese and zinc have functional roles which are essential for various diverse physiological and biochemical activities in the body. However, some of these heavy metals in high doses can be harmful to the body while others such as cadmium, mercury, lead, chromium, silver, and arsenic in minute quantities have delirious effects in the body causing acute and chronic toxicities in humans. The focus of this chapter is to describe the various mechanism of intoxication of some selected heavy metals in humans along with their health effects. Therefore it aims to highlight on biochemical mechanisms of heavy metal intoxication which involves binding to proteins and enzymes, altering their activity and causing damage. More so, the mechanism by which heavy metals cause neurotoxicity, generate free radical which promotes oxidative stress damaging lipids, proteins and DNA molecules and how these free radicals propagate carcinogenesis are discussed. Alongside these mechanisms, the noxious health effects of these heavy metals are discussed

Growth and performance analysis of Amaranthus hybridus L. Enriched with organic (sugarcane bagasse-based) fertilizer

The study was carried out to determine the growth and performance analysis of A. hybridus enriched with organic and inorganic fertilizer in Odi, Bayelsa State, between February and March 2017. The study adopted a randomized complete block design (RCBD), with three replications. Data were obtained for plant height, number of leaf, stem girth, leaf width, leaf length and weight of plant on ten (10) plants that were randomly sampled. The results obtained 49 days after planting (DAP), showed significant differences (p&lt;0.05) in plant height (80.07 cm), leaf length (33.94 cm), leaf width (12.43 cm), stem girth (7.20 cm) and mean number of leaves (38.80) respectively in treatment A (Organic). Similarly, plants in treatment A also recorded more weight than other treatments with weight of 5.5 kg. Based on the findings, sugarcane bagasse-based organic fertilizer may be recommended for maximum growth and returns of A. hybridus and other cropsKeywords: Amaranthus hybridus, Organic fertilizer, Inorganic fertilizer, Od