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Lipid altering potential of moringa oleifera lam seed extract and isolated constituents in Wistar rats
Published 2020Subjects: “…High Density Lipoprotein…”
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DETERMINANTS OF RESIDENTIAL HOUSING CHOICE IN LAGOS STATE, NIGERIA
Published 2011-09Subjects: “…Residential densities…”
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Page will reload when a filter is selected or excluded.- Nigeria 2 results 2
- Season 2 results 2
- Stocking density 2 results 2
- Students’ housing 2 results 2
- Systems theory 2 results 2
- Transit time 2 results 2
- University of Ibadan 2 results 2
- density 2 results 2
- population density 2 results 2
- 4- acetyl benzylisothiocyanate-O –α-L rhamnopyranoside 1 results 1
- A large number of hetero-aromatic and carbonyl molecules are useful in pharmaceutical and dye industries. Studies of their transition dipole moment (∆μ) and transition polarizability (∆α) are important because they determine their solubility and usefulness. Experimental determination of these parameters and other electronic properties such as oscillator strength (f) using Solvatochromic Shift Equations (SSE) has proved to be unreliable. This is due to the large spread in their reported values and the overlapping of the electronic transition bands for a given molecule. This study was designed to modify the SSE in improving its reliability, and to computationally determine the photophysical properties of some hetero-aromatic and carbonyl compounds with a view to studying the extent of overlap of the electronic transition bands. The ultra-violet spectra of 2,3-diphenylcyclopropenone; 9,10-phenanthrenequinone; Furan-3,4-dicarboxylic acid; 3,4-diphenylthiophene; 3,4-dicarboxylic-2,5-diphenylthiophene and benzo[b]thiophene in the wavenumber range (25,000 - 52,631) cm-1, in solvents of different polarities at concentrations range of 10-6 - 10-5 M were measured at 25oC. These compounds were selected for the modified SSE due to the variation in their structures. The magnitudes of f in solution (fs) and in vapour phase (fv) were calculated using the Onsager-Abe reaction field model equations. The frequencies of electronic transitions in various solvents were used to characterise the observed bands. The SSE was modified by incorporating the molecular ground state polarizability (α), the molar refraction of each compound, Einstein coefficient and stark term. Estimation of the Δµ and Δα of these compounds were determined using the modified SSE. The electronic properties: f, number of transitions, the frontier orbitals energy gap (ΔELUMO-HOMO) and associated parameters such as: Ionization Potential (IP) and global hardness (ƞ) of the optimized structures of the molecules were calculated based on Time-Dependent Density Functional Theory using Becke’s three parameter with Lee-Yang-Parr modification and 6-31G* basis set. The spectra of these compounds gave a range of one to five bands designated as S0-S1, S0-S2, S0-S3, S0-S4 and S0-S5 in order of increasing energy. The magnitudes of fs and fv for the observed bands increased with increasing solvent polarities and were within the range 3.2x10-4 - 1.78 and 3.1x10-4 - 1.33 for hetero-aromatics; 1.4x10-3 - 1.52 and 1.3x10-3 - 1.23 for carbonyls. Similar trends observed for the experimental values of Δµ and Δα indicated that the more a transition is allowed, the greater the probability Δµ being larger than zero. The positive values of Δµ (5.7x10-3 - 1.73D) and Δα (8.0x10-5 - 5.5Å3) for hetero-aromatics; Δµ (3.7x10-2 - 1.23D) and Δα (4.8x10-4 - 0.95Å3) for carbonyls indicated substantial redistribution of the π-electron densities in more polar excited state than the ground state. The ΔELUMO-HOMO were (3.19 - 4.09eV) and (4.36 - 5.43eV) for carbonyls and hetero-aromatics respectively. The IP and ƞ increased as solvent polarity increased, suggesting high stability of these compounds in polar solvents. The modified equation is better in the estimation of transition dipole moment and transition polarizability. The energy gaps and associated parameters suggested strong activity of the molecules and minimal overlapping of the transition bands. 1 results 1
- Abundance 1 results 1
- Across West and Central Africa, duikers are important for trade and consumption; their populations are expected to become depleted. Reliable data on their status are scanty in Nigeria. We assessed duiker populations in the Oban Sector of Cross River National Park through diurnal and nocturnal surveys along 32 transects of 2 km each. After 508-km survey effort, only Ogilby’s duiker (Cephalophus ogilbyi) and blue duiker (Philantomba monticola) were recorded. Using habitat as a covariate in modeling detection probability in DISTANCE 6.0, we estimated densities for the blue duiker ranging from 15.5 (95% CI: 7.8–30.9) in the core, 5.8 (CI: 2.6–12.9) in the buffer and 0.9 (CI: 0.09–10.1) km² in farm fallow to no duikers in the plantation. For Ogilby’s duiker, densities ranged from 1.6 (95% CI: 0.7–3.7) km² in the core, 2.0 (CI: 0.8–5.1) in buffer to no duikers in farm fallow and plantation. The apparent absence of yellow-backed and Bay duikers may indicate local depletion. We call on all stakeholders to rise up to the challenge of rescuing this biological hotspot in Nigeria from further degradation and species loss through improved funding for well-equipped field staff and institutionalized community wildlife management 1 results 1
- Antilipase 1 results 1
- Bambusa vulgaris 1 results 1
- Broadcast Storm 1 results 1
- Broadcasting 1 results 1
- Broilers, stocking density, performance, carcass yield, meat composition 1 results 1
- Congestion 1 results 1
- Conservation 1 results 1
- Continuous maize production 1 results 1
- Count-based indices and distance sampling are widely used to monitor primate populations. Indices are often confounded by variation in detectability, whereas distance sampling is generally ineffective with species that flee or hide from observers and where it is difficult to accurately measure detection distances. We tested occupancy modeling as a means to monitor Sclater’s monkey (Cercopithecus sclateri), an endemic of Nigeria. We evaluated effects of survey methodology, habitat, and human disturbance on detection probability and site occupancy. Average detectability was high (p = 0.81), but varied substantially between two observers. Occupancy was highest in areas with intermediate levels (20–40%) of farmland and secondary forest, and was unaffected by human disturbance. Sampling plots (4 and 6.25 ha) did not concurrently contain[1 monkey group, were likely closed to monkey movements during the replicate surveys of each plot, and were spatially separated so that it was unlikely the same group was observed in [1 plot. These conditions enabled the conversion of occupancy to group density. Scaled to 6.25 ha, model-weighted occupancy averaged 0.230 (SE 0.103), yielding an estimate of 3.7 groups/km2 (95% CI 1.4–7.7 groups/km2). Because some groups straddled plot boundaries, we assumed that half of these groups were inside the plots, resulting in an adjusted estimate of 3.1 groups/km2. Our results illustrate that occupancy can be suitable for monitoring vigilant forest primates where detection distances are difficult to measure. However, special attention is required to choose spatial and temporal scales that accommodate the method’s closure and independent-detection assumptions. 1 results 1
- Counter-Based Scheme 1 results 1
- Cover crop density 1 results 1
- Cowpea 1 results 1
- Crop Rotation (CR) and planting of Cover Crops (CC) are important methods of weed management for sustainable crop production.These and various other methods are usually integrated to enhance weed management in crop production. While reports abound on integrated weed management involving these and other practices, there is inadequate information on integrated use of Pre-emergence Herbicides (PH), CC, and CR in maize production. Therefore, effects of continuous use of CC with PH were evaluated in Ibadan for maize production. Hundred, 75, 50 and 25% of the recommended rates of maize-based PH (atrazine, atrazine+ metolaclor® and metolaclor®) were evaluated on the performance of Cowpea (α), Melon (β), Pumpkin (γ) and “Akidi” (Vigna unguiculata sub-sp sesquipedalis) (θ).The densities of 10,000 and 20,000 plants/ha for γ and α/β/θ respectively were integrated with the effective minimum dose of the PH and evaluated on weed control and maize performance. The appropriate sequence of the CC complemented with hoe-weeding at four Weeks After Sowing (WAS) for weed suppression in intensive maize cropping over four cropping cycles in two years was also evaluated in randomized complete block design. The CC sequences were combinations of any of γ/βand θ/α in early and late seasons (βθγα/βαγθ/γθβα/γαβθ) and continuous sole CC (ββββ/θθθθ/γγγγ/αααα) over four cropping cycles. The controls in each case were three hoe-weedings and unweeded maize plots. Data collected on emergence and Dry Matter Yields (DMY) of the CC, Ground Coverage (GC) of CC,Weed Density (WD), weed biomass at 8 WAS and Maize Grain Yield (MGY) were analysed using descriptive statistics and ANOVA at p=0.05. 1 results 1
- Crop sequence 1 results 1
- Crude cassava water extract 1 results 1
- DNA viscosity study 1 results 1
- Density 1 results 1
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