27 research outputs found
TAX APPEAL PROCEDURE IN NIGERIA: REQUIREMENT FOR PAYMENT OF SECURITY DEPOSIT PRIOR TO FILING AN APPEAL AGAINST ADVERSE TAX ASSESSMENTS AND ADVERSE TAX RULINGS
Recent legislation and administrative rules now require an aggrieved taxpayer to pay a security deposit prior to prosecuting a tax appeal. It is argued that the tax appeal procedure must not deny an aggrieved taxpayer of his right to a fair hearing under Sections 6(6) and 36 of the 1999 Nigerian Constitution. The method adopted in the Paper is to review all the applicable statutes and the decisions of the Nigeria Tax Appeal Tribunal (TAT), while taking the position that the administrative court rules mandating payment of security deposits are untenable in law, equity, and in practice. The Paper finds that there are multiple statutes providing for payment of security deposit pending tax appeal, to wit- (a) 2007 Federal Inland Revenue Service (Establishment) Act, (b) Federal High Court (Federal Inland Revenue Service) Practice Directions 2021, (c) Tax Appeal Tribunal (Procedure) Rules 2021, and (d) Federal High Court (Tax Appeal) Rules 2022. The constitutionality, scope and extent of the security deposit requirement have become a subject matter of intense discourse, with conflicting TAT decisions in Multichoice v. FIRS, First Bank v Taraba, and Investment Holdings v. FIRS. There are no decisions of the superior courts on these provisions yet. The Paper concludes that security deposit requirement provisions violate the fair hearing rules under the 1999 Constitution and that disputes on taxes payable to the sub-National States (tax revenue accruable to States) are clearly not subject to the security deposit payment rules. The paper recommends the introduction of an amendment for the appointment of a Special Panel to hear tax appeals where there are conflicting cases filed before or decisions issued by coordinate tax appeals/tribunals so as to prevent multiple opinions
LHRH-Conjugated Drugs as Targeted Therapeutic Agents for the Specific Targeting and Localized Treatment of Triple Negative Breast Cancer
Bulk chemotherapy and drug release strategies for cancer treatment have been associated with lack of specificity and high drug concentrations that often result in toxic side effects. This work presents the results of an experimental study of cancer drugs (prodigiosin or paclitaxel) conjugated to Luteinizing Hormone-Releasing Hormone (LHRH) for the specific targeting and treatment of triple negative breast cancer (TNBC). Injections of LHRH-conjugated drugs (LHRH-prodigiosin or LHRH-paclitaxel) into groups of 4-week-old athymic female nude mice (induced with subcutaneous triple negative xenograft breast tumors) were found to specifically target, eliminate or shrink tumors at early, mid and late stages without any apparent cytotoxicity, as revealed by in vivo toxicity and ex vivo histopathological tests. Our results show that overexpressed LHRH receptors serve as binding sites on the breast cancer cells/tumor and the LHRH-conjugated drugs inhibited the growth of breast cells/tumor in in vitro and in vivo experiments. The inhibitions are attributed to the respective adhesive interactions between LHRH molecular recognition units on the prodigiosin (PGS) and paclitaxel (PTX) drugs and overexpressed LHRH receptors on the breast cancer cells and tumors. The implications of the results are discussed for the development of ligand-conjugated drugs for the specific targeting and treatment of TNBC
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An investigation of the viscoelastic properties and the actin cytoskeletal structure of triple negative breast cancer cells
An improved understanding of the evolution of cell structure and viscoelasticity with cancer malignancy could enable the development of a new generation of biomarkers and methods for cancer diagnosis. Hence, in this study, we present the viscoelastic properties (moduli and viscosities) and the actin cytoskeletal structures of triple negative breast cancer (TNBC) cells with different metastatic potential. These include: MCF-10A normal breast cells (studied as a control); MDA-MB-468 cells (less metastatic TNBC cells), and MDA-MB-231 cells (highly metastatic TNBC cells). A combination of shear assay and digital imaging correlation (DIC) techniques is used to measure the local viscoelastic properties of live breast cells subjected to constant shear stress. The local moduli and viscosities of the nuclei and cytoplasm are characterized using a generalized Maxwell model, which is used to determine the time-dependent creep responses of cells. The nuclei are shown to be stiffer and more viscous than the cytoplasms of the normal breast cells and TNBC cells. The MCF-10A normal breast cells are found to be twice as stiff as the less metastatic MDA-MB-468 breast cancer cells and over ten times stiffer than the highly metastatic MDA-MB-231 breast cancer cells. Similar trends are also observed in the viscosities of the nuclei and the cytoplasms. The measured differences in cell viscoelastic properties are also associated with significant changes in the cell cytoskeletal structure, which is studied using confocal fluorescence microscopy. This reveals significant differences in the levels of actin expression and organization in TNBC cells as they become highly metastatic. Our results suggest that the shear assay measurements of cell viscoelastic properties may be used as effective biomarkers for TNBC diagnosis and screening
Fracture and Toughening of Mycelium-based Biocomposites
This study presents a combined experimental and analytical study of the fracture behavior and toughening mechanisms of bioprocessed mycelium-based biocomposites. The composites comprise hemicellulose hemp ducts (as nutritional and reinforcing components) intertwined with increasing weight percentages of laterite particles. Single-edge notched fracture experiments and in-situ observations of crack growth were used to explore the effects of varying proportions of laterite on the composite resistance-curve behavior. The toughening mechanisms, fracture modes, and crack-microstructure interactions were also elucidated. Since crack-bridging and crack-deflection were observed to be the dominant toughening mechanisms, they were modeled using fracture mechanics approaches. Crack-bridging was shown to dominate the toughening at lower weight fractions of laterite (0–20 wt%). However, as the laterite content increases (20–40 wt%), a combination of crack-bridging and crack-deflection was observed. Finally, at higher laterite weight fractions (>40 wt%), crack-tip shielding occurred primarily via crack deflection. The fracture mechanics predictions of resistance-curve behavior are shown to be consistent with the experimental measurements. The results suggest that mycelium-based and mycelium-laterite composites can be engineered with tunable fracture toughness. The implications of the results are also discussed for the development of sustainable building materials
Design and Fabrication of a Single Slope Solar Still with Variable Collector Angle
Abstract-This work presents the development of a flexible, efficient, robust and low cost single solar still. Experimental investigations were carried out on two single slope solar stills: a modified solar still with variable collector/inclination angle (still A), and a conventional solar still with rigid angle of collector/inclination (still B). The significance of the design is its ability to be able to optimally function properly by variation of the angle at which solar radiation is optimally incident on the system at different locations and time. Also, the experiment was carried out at latitude of 11º 20 ′ in Samaru, Zaria – Nigeria, during an average period of solar radiation. Experimental results between the hours of 8.00 am and 5.00 pm for a period of 5 days were carefully obtained and analyzed. The results clearly show that distillate peak yield occurred between 2.00 pm and 3.00 pm while minimum yield was obtained between 8.00 am and 9.00 am during the period of experiment. It was observed that, still B had an average yield of 1.366 liter/day/m 2 as compared to still A, (1.407 liter/day/m 2). Furthermore, the results obtained for the two single slope solar stills were analyzed using a statistical model (a paired T-test). The outcomes clearly suggest that, there is no significant difference between the distillate of still A (efficiency of 42%) and still B (efficiency of 39%). Implications of the results from the design are discussed for the development of robust and dynamic single slope solar still systems with variable collector/inclination angle. This has the potential and capacity to produce distilled water for domestic, industrial and commercial purposes irrespective of the geographical location
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Abstract C60: Injectable, biodegradable micro- and nano-particles loaded with prodigiosin-based drug for localized anticancer drug delivery
This paper presents the synthesis and physicochemical characterization of injectable, multi-functional, biodegradable poly (D,L-lactide-co-glycolide) (PLGA)-loaded micro- and nano-particles. These particles were loaded with an anticancer drug from prodigiosin (PG), which was obtained from bacteria, Serratia marcescens subsp. Marcescens. The release of paclitaxel (PT) was also tested as a control. The PG and PT were encapsulated using a single-emulsion solvent evaporation technique with PLGA as a polymer matrix and poly-(vinyl alcohol) (PVA) as an emulsifier. The dependence of particle size and morphology on processing conditions was also evaluated. In vitro release studies were used to elucidate drug loading efficiency, encapsulation efficiency and microparticle morphology using a combination of UV-visible (UV-Vis) spectrophotometry, optical Microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and atomic force microscopy (AFM). The implications of the results are then explored using MDA-MB-231 cells (breast cancer cells) for the development of injectable, multi-functional, polymeric micro- and nano-particles for the controlled release of cancer drugs and the localized treatment of cancer
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Extended pulsated drug release from PLGA-based minirods
The kinetics of degradation and sustained cancer drugs (paclitaxel (PT) and prodigiosin (PG)) release are presented for minirods (each with diameter of ~5 and ~6 mm thick). Drug release and degradation mechanisms were studied from solvent-casted cancer drug-based minirods under in vitro conditions in phosphate buffer solution (PBS) at a pH of 7.4. The immersed minirods were mechanically agitated at 60 revolutions per minute (rpm) under incubation at 37 °C throughout the period of the study. The kinetics of drug release was studied using ultraviolet visible spectrometry (UV-Vis). This was used to determine the amount of drug released at 535 nm for poly(lactic-co-glycolic acid) loaded with prodigiosin (PLGA-PG) samples, and at 210 nm, for paclitaxel-loaded samples (PLGA-PT). The degradation characteristics of PLGA-PG and PLGA-PT are elucidated using optical microscope as well as scanning electron microscope (SEM). Statistical analysis of drug release and degradation mechanisms of PLGA-based minirods were performed. The implications of the results are discussed for potential applications in implantable/degradable structures for multi-pulse cancer drug delivery