151 research outputs found

    TIME SERIES FORECAST MODELS FOR FOREIGN EXCHANGE MARKET IN A DEVELOPING ECONOMY

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    Technicalities in foreign exchange forecasting have been of interest to investors and academia, particularly in a developing economy. Data of foreign exchange are time series in nature and several techniques have been developed to modeling and forecasting foreign exchange rates. In this study, Nigeria's foreign exchange rate against three world-leading currencies (US Dollars, Euro and Pounds Sterling) are modeled with ARIMA, Auto. arima, Box-Cox, random walk forecast, and Exponential Smoothing and subjected to comparative tests usingĀ  Diebold-Mariano criteria with a modern model time series model. The empirical analysis shows that that the modern model outperforms some of the other techniques in forecasting Nigeria exchange rates against world-leading currencies particularly when the forecast horizon is low

    Effect of PH on Geotechnical Properties of Laterite Soil Used in Highway Pavement Construction

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    Laterite is one of the major materials used in highway pavement construction in Nigeria. Its properties are affected by some environmental factors which may make it unsuitable for highway pavement construction. This research was aimed of investigating the effect of pH on geotechnical properties of Laterite soil used in highway construction. Laterite soil sample was collected from a burrow pit at LAUTECH and it was sun dried for about 24 hours and then soaked in different pH solutions (pH =3.0, pH=5.0, pH = 7.0 and pH= 9.0) using diluted tetraoxosulphate (vi) acid (H2SO4) and ammonia. The container was perforated at the bottom in order simulate the actual field condition. The soil samples were taken from soaked sample at 14, 28, 42, 56, 70 and 84 days for sun drying and subsequent laboratory tests. The original and treated samples were subjected to the following laboratory tests: Sieve analysis, Liquid and Plastic limits, Plasticity index, British standard compaction and California bearing ratio. The results showed that the pH of the solution has strong influence on the geotechnical characteristics of the Laterite soil when compared with the original soil sample. This influence caused reduction on the strength properties of the soil and thereby rending it unsuitable for highway construction. Keywords: Laterite, pH, consistency limits, California bearing ratio

    Climate Change Dynamics and Imperatives for Food Security in Nigeria

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    Decadal variability in African rainfall is projected from General Circulation Models (GCMs) to continue under elevated greenhouse gas scenarios. Effects on rain intensity, spatio-temporal variability of growing seasons, flooding, drought, and land-use change impose feedbacks at regional-local scales. Yet, empirical knowledge of associated impacts on crop yield is limited; thus, we examined the imperatives for food security in Nigeria. Bivariate correlation and multiple regression suggests impending drought in the northern region where livestock farming is predominant. Relative contributions of climate independent variables in determining crop yield by backward selection procedures with stepwise approach indexed the impacts of annual climate variability by a parameter computed as annual yield minus mean annual yield divided by the standard deviation. Results show Z-distribution approximately 5 to + 5, when 3 indicate impacts significant at 95% confidence levels. In conclusion, we established the interwoven relationship between climatic change and food security

    Fruits and Vegetables Diet Improves Kidney Functions and Electrolyte Status in Non-Insulin Dependent Diabetes Mellitus (N.I.D.D.M) Subjects

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    Kidney failure and electrolyte imbalance are some of the complications associated with diabetes mellitus, if prompt treatment is not instituted it may lead to renal disease and dietary influence has been established on the prognosis of many diseases. Thus effects of fruits and vegetables diet were investigated on kidney functions and electrolyte status of some selected Non-Insulin dependent diabetic subjects at the cardiovascular clinic of Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria. The patients with mean fasting blood glucose (FBG) 7.84Ā± 0.95 mmol dl-1 were placed on 300 g of fruits and vegetables per day in addition to their normal drugs and food intake for eight weeks. Standard laboratory methods were employed for biochemical assay; while the data were analyzed using analytic and descriptive statistics. A significant difference (p < 0.05) was noticed between baseline and eighth weekā€™s values in the following parameters: plasma creatinine, 3.48Ā± 0.095 to 1.79Ā±0.57 mgdL-1; urea, 39.05Ā±2.04-23.20Ā±1.50 and uric acid 5.37Ā± 0.27-2.50Ā±0.59 mgdL-1. No significant difference (p > 0.05) was observed in plasma electrolyte values when theĀ Ā Ā  baseline value were compared with the eighth weekā€™s values. After the eight weeks, the fruits and vegetables rations were stopped for two weeks and the parameters were measured again. Significant difference(p<0.05) were observed in all the values by comparing week eight with week ten values; plasma creatinine, 1.79Ā±0.52 to 3.01Ā± 0.68 mgdl-1,plasma urea, 39.05Ā± 2.40 to 23.20Ā± 1.50Ā  mgdl-1 and plasma uric acid 2.50Ā±0.59 to 3.61Ā±0.50 mgd-1, however no significant difference (p> 0.05) was observed in serum electrolyte. Our results showed that fruits and vegetables consumption improved kidney function and did not affect plasma electrolytes adversely. KEY WORDS: Diabetes mellitus, kidney functions, creatinine, urea, uric acid fruits and vegetable

    Strength Modelling of Soil Geotechnical Properties from Index Properties

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    This research work presents strength models developed for the class of soils encountered. An empirical, analytical model is developed to predict the CBR and shear stress of soil from its index properties and grade size, with a view to reducing time, effort and cost usually incurred in determining these tests in the laboratory for future planning, design and construction projects. Soil samples were collected from various locations in Ife central local government. Various available index property tests, such as sieve analysis, Atterberg limit test and specific gravity test were carried out and classification of samples performed. Compaction test, California Bearing Ratio test and triaxial test were also carried out with the Optimum Moisture Content (OMC), Maximum Dry Density (MDD), unsoaked California Bearing Ratio (CBR), internal angle of friction Ļ†, cohesion c and shear stress determined. Regression models related to these index properties together were developed and tested to ascertain their effectiveness. The study showed that about 44.4% of the soil mass of the Ife central local government is poorly graded soil with gravel, followed by 33.3% of well graded soil with gravel. Linear and non-linear relationships were generated between various soil indicies and engineering properties through correlation analysis with a reliable coefficient of determination (R). Poorly graded soil with gravel cannot be effectively correlated because of its weak coefficient of determination

    Anaemia in HIV positive mothers on antiretroviral therapy for prevention of mother-to-child transmission HIV in a tertiary health institution in North Central Nigeria

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    Background: Anaemia in pregnancy and HIV infection are two common public health issues in sub-Saharan African with Nigeria bearing the greatest burden. The duo occurring together poses a higher risk of morbidity and mortality for both the foetus and the mother. We therefore conducted this study to determine the burden of anaemia and other haematological abnormalities among HIV positive pregnant mothers on antiretroviral therapy who attended antenatal clinical services in our health institution.Methods: A 10-year retrospective review from January 2010 to December 2019 of medical records of HIV positive mothers on highly anti-retroviral therapy in attendance for antenatal clinical services in our health institution was carried out for the above objectives. Information extracted were, age, HIV status, gestational age at delivery, type of antiretroviral drugs used, duration of use, haemoglobin level, platelet, and complete blood count at booking of the positive mothers.Results: Of a total of 330 HIV positive mothers seen during the review period, 82.7% were from rural communities, 88.8% were from middle socio-economic class, 80.0% were Christians, and 80.3% started their highly active antiretroviral therapy before their index pregnancy. Most, 51.5% and 42.7% were on zidovudine, lamivudine and nevirapine, and tenofovir with lamivudine and lopinavir boasted ritonavir combinations, while 94.2% were on 1st line antiretroviral medication. Their mean age, gestational age at delivery, and parity were 31.11Ā±4.7 years, 38.57Ā±3.1 weeks, and 2.0Ā±1.6 respectively. The prevalence of anaemia, thrombocytopenia and leucopoenia were 36.1%, 4.8%, and 6.7% respectively while their mean CD4 cell count and viral loads at the point of booking were 543.63Ā±283.7 cells/Ī¼l, and 2953.02Ā±1619.9 copies/ml. The two maternal variables that showed significant relationship with haemoglobin concentration of <10 gm/dl was motherā€™s level of education x2=6.29, p=0.043, and her socio=economic class, x2=10.162, p=0.006.Conclusions: There is high burden of anaemia among HIV positive mothers on antiretroviral therapy in our environment. The prevalence of thrombocytopenia and leucopoenia was much lower. The burden of maternal anaemia was associated with maternal level of education and her socio-economic class

    Econometric analysis of profit efficiency of broiler farms in Ondo state, Nigeria

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    Researchers have recently focused their attention on the chicken producers' inability to produce in sufficient quantities and quality, which contributes to the high price of locally produced chickens. The study investigated the profit efficiency of broiler farms in Ondo state, Nigeria. In order to collect cross-sectional data from sixty owners of broiler poultry farms in the study area between October 2021 and January 2022 for the 2021 production year, a multistage survey technique was used. The data were an-alyzed using descriptive statistics, gross margin and Cobb-Douglas stochastic profit frontier model. Average stock size and mortality rate of farmers were 1826 birds and 3.3% respectively while Ross strain of birds was most preferred birds. The result indicated that broiler farming is a lucrative busi-ness with a profitability index of 45.5 %. The results reveal that the cost of feed, cost of labour used and day-old chicks were the variables that significantly explained the profit efficiency of broiler poul-try farms while household size, years of experience and other income source were the profit inefficien-cy variables. The study recommends government supports to broiler farms in form of input subsidies to enhance efficienc

    Integrinā€Targeted, Short Interfering RNA Nanocomplexes for Neuroblastoma Tumorā€Specific Delivery Achieve MYCN Silencing with Improved Survival

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    The authors aim to develop siRNA therapeutics for cancer that can be administered systemically to target tumors and retard their growth. The efficacy of systemic delivery of siRNA to tumors with nanoparticles based on lipids or polymers is often compromised by their rapid clearance from the circulation by the liver. Here, multifunctional cationic and anionic siRNA nanoparticle formulations are described, termed receptorā€targeted nanocomplexes (RTNs), that comprise peptides for siRNA packaging into nanoparticles and receptorā€mediated cell uptake, together with lipids that confer nanoparticles with stealth properties to enhance stability in the circulation, and fusogenic properties to enhance endosomal release within the cell. Intravenous administration of RTNs in mice leads to predominant accumulation in xenograft tumors, with very little detected in the liver, lung, or spleen. Although nonā€targeted RTNs also enter the tumor, cell uptake appears to be RGD peptideā€dependent indicating integrinā€mediated uptake. RTNs with siRNA against MYCN (a member of the Myc family of transcription factors) in mice with MYCNā€amplified neuroblastoma tumors show significant retardation of xenograft tumor growth and enhanced survival. This study shows that RTN formulations can achieve specific tumorā€targeting, with minimal clearance by the liver and so enable delivery of tumorā€targeted siRNA therapeutics

    An integrated single-cell analysis of human adrenal cortex development

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    The adrenal glands synthesize and release essential steroid hormones such as cortisol and aldosterone, but many aspects of human adrenal gland development are not well understood. Here, we combined single-cell and bulk RNA sequencing, spatial transcriptomics, IHC, and micro-focus computed tomography to investigate key aspects of adrenal development in the first 20 weeks of gestation. We demonstrate rapid adrenal growth and vascularization, with more cell division in the outer definitive zone (DZ). Steroidogenic pathways favored androgen synthesis in the central fetal zone, but DZ capacity to synthesize cortisol and aldosterone developed with time. Core transcriptional regulators were identified, with localized expression of HOPX (also known as Hop homeobox/homeobox-only protein) in the DZ. Potential ligand-receptor interactions between mesenchyme and adrenal cortex were seen (e.g., RSPO3/LGR4). Growth-promoting imprinted genes were enriched in the developing cortex (e.g., IGF2, PEG3). These findings reveal aspects of human adrenal development and have clinical implications for understanding primary adrenal insufficiency and related postnatal adrenal disorders, such as adrenal tumor development, steroid disorders, and neonatal stress

    Prospects for Genomic Selection in Cassava Breeding

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    Article purchased; Published online: 28 Sept 2017Cassava (Manihot esculenta Crantz) is a clonally propagated staple food crop in the tropics. Genomic selection (GS) has been implemented at three breeding institutions in Africa to reduce cycle times. Initial studies provided promising estimates of predictive abilities. Here, we expand on previous analyses by assessing the accuracy of seven prediction models for seven traits in three prediction scenarios: cross-validation within populations, cross-population prediction and cross-generation prediction. We also evaluated the impact of increasing the training population (TP) size by phenotyping progenies selected either at random or with a genetic algorithm. Cross-validation results were mostly consistent across programs, with nonadditive models predicting of 10% better on average. Cross-population accuracy was generally low (mean = 0.18) but prediction of cassava mosaic disease increased up to 57% in one Nigerian population when data from another related population were combined. Accuracy across generations was poorer than within-generation accuracy, as expected, but accuracy for dry matter content and mosaic disease severity should be sufficient for rapid-cycling GS. Selection of a prediction model made some difference across generations, but increasing TP size was more important. With a genetic algorithm, selection of one-third of progeny could achieve an accuracy equivalent to phenotyping all progeny. We are in the early stages of GS for this crop but the results are promising for some traits. General guidelines that are emerging are that TPs need to continue to grow but phenotyping can be done on a cleverly selected subset of individuals, reducing the overall phenotyping burden
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