Potential Impacts of Free Trade Areas and Common Currency on Sustainable Agricultural Export in Africa

Peer reviewedPublisher PD

Dysregulation of Gene Expression in the Artificial Human Trisomy Cells of Chromosome 8 Associated with Transformed Cell Phenotypes

A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells) by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression

Microglial Interactions with Synapses Are Modulated by Visual Experience

Microglia, the brain's immune cells, show unique interactions with nearby synaptic elements under non-pathological conditions that are sensitive to changes in sensory experience

FTIR and ESR studies of VO2+ and MN2+ doped glasses of system 59B(2)O(3)-10As(2)O(3)-(30-x)PbO-xBaO

FTIR and the electron spin resonance studies on 59B(2)O(3)-10As(2)O(3)-(30 - x)PbO-xBaO (x = 0, 7.5, 15, 22.5, 30 mol %) glasses containing 1 mol % V2O5, or MnO2 have been carried out. The ESR spectra of V4+ ion in the glass system were recorded at X-band frequencies at 300 K. The V4+ ion in the present glass system exists as VO2+ ion in octahedral coordination with tetragonal compression. The site symmetry of vanadyl is C-4v and the ground state of 3d (1) ion is d (xy) . The spin-Hamiltonian parameters (g (aEuro-), g (aSyen) and A (aEuro-)) of VO2+ ions in the present glasses have been estimated. The spectra consist of resonance lines centered at g a parts per thousand 4.3 and g a parts per thousand 2. The resonance line centered at g a parts per thousand 4.3 has been attributed to the rhombic symmetry of the Mn2+ ions. The resonance signal at g a parts per thousand 2 is attributed to the Mn2+ ions in an environment close to an octahedral symmetry. The absence of boroxol ring in the present glass system suggested that these glasses consist of randomly connected BO3 and BO4 units. The conversion of BO3 to BO4 takes place in the glasses under investigation

Role of WO3 on DC conductivity and some optical properties of TeO2 based glasses

DC electrical conductivity and optical absorption studies have been employed to understand the influence of WO3 content on the electrical and optical properties of the TeO2-GeO2-WO3 glass system. Field emission scanning electron microscope (FESEM), Energy dispersive X-ray spectrometry (EDS) measurements have been used to confirm the glassy nature and the elemental analysis of the glass composition, respectively. DC electrical conductivity of the glasses was studied in the temperature range 423-613 K. From Arrhenius plot, the activation energies (E-act) of all the glasses have been calculated and conduction mechanism has been discussed in terms of structural changes occurred with the addition of WO3 content. The optical properties such as optical band gap (E-opt), Urbach energy (Delta E), molar refraction (R-M), metallization criterion (M), electronic polarizability of the oxide ion (alpha(o2-)) and refractive index (n) have been determined from optical absorption data and were found to be composition dependent. (c) 2012 Elsevier Ltd. All rights reserved

Infrared, ESR and optical absorption studies of Cu²⁺ ions doped in TeO₂-ZnO-NaF glass system

709-715Glasses of composition 80TeO2-(20−x)ZnO-xNaF mol % were prepared by melt quenching technique and characterized by ESR, optical absorption and infrared spectroscopy. The IR spectra reveal that the glass consists of TeO3, TeO4, Te(O,F)3 and Te(O,F)4 units as local structure of the glass network. The hydroxyl group concentration decreases with the increase of NaF content. From ESR spectra, it is found that the Cu2+ ions are in octahedral sites with tetragonal distortion with as ground state. From the ESR and optical absorption studies, molecular orbital coefficients were calculated and correlated with the structural variation of the glass system. From the optical absorption data, the optical band gap (Eopt) and Urbatch energy (ΔE) values were calculated. It is found that Eopt values increase with NaF content. The low ΔE values showed that the present glasses were highly homogenous and stable