339 research outputs found

    Determination of Dar Zarouk Parameters for the Assessment of Groundwater Resources Potential: Case Study of Imo State, South Eastern Nigeria

    Get PDF
    The vertical electrical soundings (VES) method of geophysical survey using the Schlumberger configuration with a maximum electrode spread of 900m were carried out in parts of Imo State of Nigeria in order to determine the aquifer Dar Zarouk parameters. Using the estimated value of hydraulic conductivity from drilled boreholes and interpreted electrical sounding data around the borehole, the transmissivity variation within the area were determined. The values obtained are moderate and fairly uniform, ranging from 551.695 m2/day to 556.607 m2/day and are consistent with the geology of the area. The transverse resistance values ranged from 4366 measured at Okohia (VES 12) to 953310 btained at Anara (VES 11). Similarly the isoresistivity map for L/2 = 150m shows that the area is generally underlain by fairly high resistivity materials with the Western half being more resistive than the eastern part. Separating these two regions is a very narrow low resistivity area in the central part around Okohia with value of 200. The variation in resistivity could be linked to differences in geology, topography, drainage system, water quality and degree of saturation. The low resistivity observed in the central part could be associated with the presence of Oramiriukwa River. On the basis of longitudinal conductance, three major zones are identified. Zone A which covers the western and North-eastern parts is underlain by relatively low resistive aquifer materials. This zone is more promising for siting productive boreholes. The central area makes up Zone B while the third zone (Zone C) is underlain by high resistivity (low longitudinal conductance) aquifer materials. This zone may not be good enough for drilling boreholes with high yield expectation. Key Words: Dar Zarouk, Isoresistivity, transverse resistance, longitudina

    \u3csup\u3e13\u3c/sup\u3eC Nuclear magnetic resonance and electron paramagnetic spectroscopic comparison of hydrophobic acid, transphilic acid, and reverse osmosis May 2012 isolates of organic matter from the Suwannee River

    Get PDF
    © 2015 Mary Ann Liebert, Inc. Dissolved organic matter (DOM) is found in most natural waters at concentrations low enough to make DOM isolation methodologies critical to full analytical characterization and preservation. During the last few decades, two major protocols have been developed for the extraction of DOM isolates from natural waters. These methods utilize XAD resins and reverse osmosis (RO). In this work, the hydrophobic acid (May 2012 HPOA) and transphilic acid (May 2012 TPIA) isolates from XAD-8 and XAD-4 resins, respectively, were compared with the RO (May 2012 RO) natural organic matter isolate of the Suwannee River water using 13C nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies. 13C NMR analysis showed that the May 2012 RO isolate could be viewed as a hybrid of the more hydrophobic May 2012 HPOA isolate and more hydrophilic May 2012 TPIA isolate. The May 2012 HPOA isolate is shown to be higher in alkyl and aromatic moieties, while the May 2012 TPIA isolate is higher in O-alkyl moieties. EPR analysis revealed that the May 2012 TPIA and, in particular, May 2012 HPOA isolates had higher radical concentrations than the May 2012 RO isolate. It is postulated that some of the radical concentrations came from the use of base during the isolation procedures, especially in the XAD method

    Protective role of Phyllantus niruri extract on serum lipid profiles and oxidative stress in hepatocytes of diabetic rats

    Get PDF
    Diabetes mellitus has been associated with lipid abnormalities and oxidative stress. Some phytochemical properties have been shown to possess antioxidant activities, improving the effects of oxidative stress on diabetes. This present investigations confirmed that untreated diabetic rats were associated with lipid abnormalities as indicated by high levels of total- and LDL-cholesterol, triacylglycerols and low levels of HDL-cholesterol and phospholipids, compared to non-diabetic rats(control). The aqueous extract of Phyllanthus niruri significantly normalized the serum lipids levels. The study also showed that untreated diabetic rats were subjected to oxidative stress as indicated by significantly abnormal activities of their scavenging enzymes (superoxide dismutase and catalase and significantly low levels of non-enzymic antioxidants (vitamin C, vitamin E and reduced glutathione) in liver and plasma when compared with controls and in the extent of lipid peroxidation (increased malondialdehyde levels) in plasma and liver cells. The aqueous extract of P. niruri possessedantioxidant activities as shown by increased activities of enzymic and non-enzymic antioxidants and decrease in malondialdehyde levels

    Oxidative stress and non-enzymic antioxidant status in hypertensive patients in Nigeria

    Get PDF
    Oxidative stress and non-enzymic antioxidant status in plasma of hypertensive patients in Nigeria were investigated. One hundred and fifty hypertensive patients (82 males and 68 females) age range 55 – 75 years visiting Federal Medical Centre, Owerri were selected for the study. Controls were 120 apparently healthy subjects (66 males and 54 females) age range 55 -75 years. Patients with complication such as renal diseases, viral and bacterial infections were excluded from the study. In The hypertensive patients presented significantly higher mean values of plasma total cholesterol, LDL-cholesterol and triacylglycerolsand reduced HDL-cholesterol and phospholipids (p < 0.05). The result of plasma lipid peroxide was significantly higher in hypertensive patients (p < 0.05). Also the levels of non-enzymic antioxidantssuch as Vitamin C, vitamin E and reduced glutathione in plasma were significantly depleted in the hypertensive patients (p < 0.05). This study shows that hypertension is associated with increasedoxidative stress and depleted non-enzymic antioxidant status even in developing countries like Nigeria

    Reconstitution of the Olfactory Epithelium Following Injury in ApoE-Deficient Mice

    Get PDF
    ApoE, a protein component of lipoproteins, is extensively expressed in the primary olfactory pathway. Because apoE has been shown to play a vital role in nerve repair and remodeling, we hypothesized that apoE expression will increase in the injured olfactory epithelium (OE), and that apoE deficiency in apoE knockout (KO) mice will lead to delayed/incomplete reconstitution of the OE following injury. To directly test this hypothesis, we compared OE regeneration in wild-type (WT) and KO mice following injury induced by intranasal irrigation of Triton X-100. OE was collected at 0, 3, 7, 21, 42, and 56 days post lesion. The amount and distribution of apoE in the regenerating OE was measured by immunoblotting and immunohistochemistry. Rate of OE reconstitution in WT and KO mice was assessed by using three independent measures: (1) OE thickness was measured in cresyl-violet stained sections, (2) basal cell proliferation was determined by using bromodeoxyuridine (BrdU) staining, and (3) differentiation and maturation of olfactory sensory neurons were measured by immunoblotting and immunohistochemical analysis of growth associated protein (GAP) 43 and olfactory marker protein (OMP). The results revealed that apoE expression in the OE is highly regulated during the entire course of OE reconstitution post injury, and that apoE deficiency in apoE KO mice leads to delayed recovery of mature OMP+ cells in the reconstituting OE. The data suggest that apoE production increases in the injured OE to facilitate maturation of olfactory sensory neurons

    The distribution of apolipoprotein E in mouse olfactory epithelium

    Get PDF
    Previous studies from our laboratory suggest that apolipoprotein (apoE), a lipid transporting protein, facilitates olfactory nerve regeneration. We have shown that apoE is enriched in the olfactory nerve and around the glomeruli of the olfactory bulb (OB). The studies reported herein were undertaken to identify possible sources of apoE in the olfactory epithelium (OE). Immunoblotting results revealed apoE expression in the OE of wild-type (WT) mice, but not in apoE deficient/knockout (KO) mice. Immunohistochemical studies revealed that the perikarya and processes of sustentacular (Sus) cells expressed apoE-like immunoreactivity. Minimal neuronal apoE immunostaining was seen, although apoE was observed in the interstial spaces between olfactory receptor neurons (ORN). Substantial apoE-like immunoreactivity was localized to the endfeet and terminal process of Sus cells surrounding the basal cells. Double labeling immunocytochemical studies confirmed that the cell bodies and endfeet of Sus cells expressed high levels of apoE. The endothelial cells of blood vessels were intensely stained for apoE in the lamina propria. Cells forming Bowman’s gland also immunostained for apoE. The apoE staining in the nerve fascicles was less intense, but was uniformly distributed throughout the core of the nerve bundles. Heavily stained cells, probably ensheathing glia, surrounded the nerve fascicles. These results revealed that apoE is expressed in the adult OE and lamina propria at strategic locations where it could facilitate the differentiation, maturation and axonal growth of the ORN, perhaps by recycling lipids from degenerating ORN for use by growing axons

    Hepatic dysfunction is associated with vitamin D deficiency and poor glycemic control in diabetes mellitus

    Get PDF
    Background/Aims: The effect of the rising prevalence of nonalcoholic fatty liver disease on the 25-hydroxylation of pre-vitamin D in the liver, and consequent glycemic control in children with diabetes mellitus is not known. Our aim was to determine whether mild hepatic dysfunction was associated with impaired 25-hydroxylation of pre-vitamin D, and if this vitamin D deficiency was associated with impaired glycemic control in children and adolescents with type 1 diabetes (TIDM) and type 2 diabetes (T2DM). Methods: We analyzed simultaneously measured HbA1c, ALT, AST, and 25OHD levels and clinical parameters in 121 children and adolescents with T1DM (n=81) and T2DM (n=40). The subjects, ages 11–21 years, all had diabetes of \u3e6 months duration. Multivariate linear regression was used to analyze the associations, while comparisons between subgroups were made using two-tailed Student’s t-test. Results: Vitamin D deficiency (25OHD/mL (37.5 nmol/L) was more prevalent in T2DM patients (47.5%) compared to T1DM patients (18.5%). Subjects with T2DM had significantly elevated transaminases (AST 39.3±2.0 vs. 22.4±1.4, p Conclusions: The association of elevated ALT with vitamin D deficiency suggests that hepatic dysfunction could impair vitamin D metabolism and negatively impact glycemic control in youth with T2DM

    Marker Assisted Foreground Selection for Identification of Striga Resistant Backcross Lines in Sorghum bicolor

    Get PDF
    Striga is a major constraint to sorghum production causing high yield loss due to increasing infestation. Locally-adapted cultivars with resistant genes/QTLs could be an effective control strategy for Striga. Marker-Assisted Foreground Selection was used to select backcross lines possessing Striga resistance QTLs from N13. Marker polymorphism was conducted for the donor parent N13 and 10 recurrent parents using 10 Simple Sequence Repeat (SSR) markers. Recurrent parents with SSR alleles, polymorphic to the donor parent allele were selected. F1 lines were developed by making a cross between the selected recurrent parent and the donor. The F1 were confirmed for heterozygosity using SSR markers. Selected heterozygote F1s were backcrossed to their recurrent parent to develop backcross populations (BC1F1 and BC2F1). BC1F1 and BC2F1 populations were genotyped using SSR markers flanking the Striga resistant QTLs in N13. Forty two DANYANA-N13 BC2F1 lines (with 4 QTLs in 3 lines, 3 QTLs in 10 lines and other 28 lines having 1 to 2 QTLs) were selected for the presence of N13 QTLs. Forty three SAMSORG39-N13 BC2F1 lines (with 3 QTLs in 2 lines while 41 lines had 1 to 2 QTLs) were also selected for the presence of N13 QTLs. Although, selected lines will be genotyped for the recovery of recurrent parent background and evaluated to identify elite genotypes for possible release as varieties, the successful introgression of Striga resistance QTLs using Marker Assisted Selection suggests that in developing superior sorghum varieties, breeders could make use of molecular marker technologies to speed up breeding programmes

    Genetic Variation for Striga hermonthica Resistance and Yield Among Sorghum Accessions in Nigeria

    Get PDF
    Striga hermonthica (Delile) Benth., commonly referred to as witch weed, is a major constraint to sorghum (Sorghum bicolor (L.) Moench) production in the Northern region of Nigeria because of high yield losses due to infestation. To identify parental lines useful in breeding for S. hermonthica resistant sorghum genotypes adapted to Nigeria, twenty-five sorghum accessions were evaluated in Nigeria across three test environments. Both phenotypic and genetic components influenced the variation observed in the sorghum accessions. The estimates for the genetic coefficient of variation, heritability and genetic advance for the area under Striga number progress curve (ASUNPC), Striga emergence counts, yield and other agronomic traits, obtained in this study revealed that genetic gain for resistance to S. hermonthica could be realized through selection. Based on the performance of the 25 sorghum accessions SRN39, Danyana, Sepon82, and SAMSORG40 were the top four accessions found to be most resistant to S. hermonthica. Assessment of resistance was based on the low Striga emergence counts and the ASUNPC values. These accessions can be used as donor sources of S. hermonthica resistant genes for introgression into cultivars adapted to Nigeria, followed by recombination breeding for pyramiding the different resistance mechanisms

    Marker Assisted Foreground Selection for Identification of Striga Resistant Backcross Lines in Sorghum bicolor

    Get PDF
    Striga is a major constraint to sorghum production causing high yield loss due to increasing infestation. Locally-adapted cultivars with resistant genes/QTLs could be an effective control strategy for Striga. Marker-Assisted Foreground Selection was used to select backcross lines possessing Striga resistance QTLs from N13. Marker polymorphism was conducted for the donor parent N13 and 10 recurrent parents using 10 Simple Sequence Repeat (SSR) markers. Recurrent parents with SSR alleles, polymorphic to the donor parent allele were selected. F1 lines were developed by making a cross between the selected recurrent parent and the donor. The F1 were confirmed for heterozygosity using SSR markers. Selected heterozygote F1s were backcrossed to their recurrent parent to develop backcross populations (BC1F1 and BC2F1). BC1F1 and BC2F1 populations were genotyped using SSR markers flanking the Striga resistant QTLs in N13. Forty two DANYANA-N13 BC2F1 lines (with 4 QTLs in 3 lines, 3 QTLs in 10 lines and other 28 lines having 1 to 2 QTLs) were selected for the presence of N13 QTLs. Forty three SAMSORG39-N13 BC2F1 lines (with 3 QTLs in 2 lines while 41 lines had 1 to 2 QTLs) were also selected for the presence of N13 QTLs. Although, selected lines will be genotyped for the recovery of recurrent parent background and evaluated to identify elite genotypes for possible release as varieties, the successful introgression of Striga resistance QTLs using Marker Assisted Selection suggests that in developing superior sorghum varieties, breeders could make use of molecular marker technologies to speed up breeding programmes
    • …
    corecore