The Development Of Novel Imaging Modalities & High-throughput Drug Screening Platforms In The Drosophila Melanogaster Model of Human Calcium Oxalate Nephrolithiasis

Nephrolithiasis is a common urological disorder. Despite advances in the surgical treatment of kidney stone disease, research into its prevention and medical management remain stagnant. This is due to lack of viable pre-clinical models to study the disorder. In this project, we develop and characterize a robust Drosophila melanogaster model for human calcium oxalate nephrolithiasis. Using this model, we have developed intravital imaging techniques to study stone formation and novel high-throughput drug screening platforms. We successfully demonstrate calcium oxalate stone formation by sodium oxalate and ethylene glycol supplementation, with subsequent intravital imaging using bisphosphonate based fluorescent probes. Screening of 360 experimental compounds has revealed 6 compounds that inhibit calcium oxalate stone formation. We intend to further investigate the mechanism of action of these compounds, use them as a starting point for rational drug design and to develop Drosophila melanogaster models for other kidney stone types

Charge Transport and Colossal Magnetoresistance Phenomenon in La1−xZrxMnO3

In this study we have investigated the magnetic and electrical transport properties of Zr doped lanthanum manganite perovskite. The structural, magnetic, and transport properties of the Zr doped compounds were determined using x-ray diffraction, dc magnetic susceptibility, and a four probe method for electrical resistivity and magnetoresistance measurements in the temperature range of 5–400 K. The structure of the compounds was found to be rhombohedral. The magnetization versus temperature curves show ferromagnetic regions with the magnetic transition temperatures getting saturated for x ≥ 0.07 compounds. The resistivity curves show decreasing resistivity with increasing Zr content in the compound. The resistivity of the compounds is very high and is explained as due to the localization tendency of the electrons. The metal–insulator transition temperature shows a compositional dependence and has additional contributions apart from magnetism. The results are explained by the double exchange interaction and Mn2+/Mn3+ ratio, and also by taking into account the competition between the core-spin interaction and double exchange interaction

Magnetocaloric Properties of Fe and Ge Doped Ni2Mn1−xCuxGa

The magnetocaloric properties of Fe and Ge doped Ni2Mn0.75Cu0.25Ga Heusler alloys have been investigated. Using Ni2Mn0.75Cu0.25Ga as the parent material, the Fe doped system (Ni2Mn1−x(Cu–Fe)xGa) and a Ge doped system (Ni2Mn1−xCuxGa1−xGex) were studied. The manipulation of the Mn–Cu subsystem with Fe doping results in a decrease of the first order magnetostructural transition temperature, whereas the substitution of Ge for the Mn–Cu–Ga subsystems results in an increase of the magnetostructural transition temperature. In both cases the giant magnetocaloric effect is successfully preserved

Magnetic Properties of RTSb3

Magnetization, electrical resistivity, and thermal expansion measurements have been performed on polycrystalline RTSb3 (R=La, Ce, Pr, Nd, Gd, Tb, and Dy; T=Cr, V) samples in order to study their magnetic properties. Depending on the rare-earth element, RTSb3 has been found to have either a purely ferromagnetic (or antiferromagnetic) phase or combination of antiferromagnetic (lower-temperature) and ferromagnetic (higher-temperature) phases. The antiferromagnetic order evolves from the ferromagnetic order as a result of the competition between R3+ and Cr3+ ions. As R is changed from La to Dy, the antiferromagnetic ordering of the R3+ ions becomes more prominent and predominate over the ferromagnetic ordering of Cr3+ for R=Gd, Tb, and Dy. Thermal expansion measurements show that the antiferromagnetic transition accompanies a drop in the sample dimension. The order of the ferromagnetic transition is found to be of the second order

Intermartensitic Transformations in Ni2Mn1−xCoxGa Heusler Alloys

Ni2MnGa that possesses a Heusler L21 structure undergoes a martensitic transformation from the parent cubic (austenitic) phase to a low temperature complex tetragonal structure at TM = 202 K and has a Curie temperature of TC = 376 K. Some research groups have observed an intermartensitic transformation at a temperature TI\u3cTM, in Ni2MnGa single crystals. In this work detailed studies on the influence of substitution in the Mn subsystem by magnetic Co on the intermartensitic transformation properties of Ni2Mn1−xCoxGa compounds have been done by magnetization (5–400 K) and thermal expansion (80–300 K) measurements. The samples Ni2Mn0.92Co.08Ga, Ni2Mn0.91Co.09Ga, and Ni2Mn0.90Co.10Ga were studied. The intermartensitic transformation is observed in all of these alloys. As the Co concentration increases, the transformation becomes more pronounced and the temperature range for which the alloys stay in the intermartensitic state decreases as Co concentration increases. Similarities were observed between the magnetization and thermal expansion curves. The results are discussed in terms of the internal stress produced as a result of the Co substitution

Inverse Magnetocaloric Effect in Ferromagnetic Ni50Mn37+xSb13−x Heusler Alloys

A study of the magnetocaloric effect (MCE) in the ferromagnetic Heusler alloys Ni50Mn37+xSb13−x (x = 0,0.5,1) has been carried out through magnetization measurements. An inverse magnetocaloric effect was observed in the vicinity of the first order martensitic transition. A maximum positive magnetic entropy change of ΔSm ≈ 19 J/kg K at approximately 297 K for a magnetic field change of 5 T was observed. It is demonstrated that the martensitic transformation temperature, and the corresponding ΔSm, can be tuned through a slight variation in composition

Analysis of Felder-Solomon Index of Learning Styles of Students from Management and Engineering at the University of Mauritius

No prior investigations have been made on the learning styles of students from different fields studying the same module at the University of Mauritius. Techniques have to be explored to depict their learning styles, which can lead to a more effective teaching. In this work, students from faculty of management and faculty of engineering studying one of the Information Technology modules at the University of Mauritius were being studied and their learning styles were being deduced through FelderSolomon index of learning (ILS) questionnaire. The data obtained from the questionnaire has been analyzed and it was concluded that students from both faculties have different learning styles. While understanding these differences, there is a better chance to meet diverse learning needs of both groups of students

Structure and Magnetic Properties of RFe6−xGa6+x (R=rare earth)

The crystal structures and magnetic properties of RFe6−xGa6+x (R=Ce, Pr, Nd, Sm, and Gd) alloys have been investigated by x-ray powder diffraction and magnetic measurement. A ternary intermetallic compound with an orthorhombic ScFe6Ga6 type structure is found in these alloys. The lattice parameter contraction is observed when the higher atomic number lanthanides are substituted into the intermetallic. In each unit cell, there are six nonequivalent crystal positions, i.e., 2a, 4e, 4f, 4g, 4h, and 8k, which are occupied by 2R, 4GaI, 4(FeI,Ga), 4GaII, 4GaIII, and 8FeII, respectively. The RFe6−xGa6+x alloys have ferromagnetic ordering but the magnetic transitions have been found in Nd based alloy. The RFe6−xGa6+x alloys show a soft magnetic behavior but the magnetization hysteresis loops have been observed in the Nd and Sm alloys at 5 K. The saturated magnetic moments per molecule tend to increase from Ce to Nd. However, a drastic decrease of magnetic moment in GdFe6Ga6 alloy is observed and is likely due to the Gd spin alignment being antiparallel to Fe spin. The saturation magnetic moments of these alloys are calculated and agree with the experimental values