Separation of iron from semiconductor grade silicon in activation analysis

A method of separation of iron from silicon for use in the neutron activation analysis has been developed. Iron was separated by extraction with N-benzoyl-N-phenylhydroxylamine /HBPHA/ from 0.4N HCl solution followed by extraction at pH=3.0. The lower limit of determination was 9.9×10^–9 g.     

Study of structural and electronic transport properties of Ce-doped LaMnO3

The structural and electronic transport properties of La_1−x Ce _x MnO₃ (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration up to 50% doping. The system La_0.5Ce_0.5MnO₃ also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition.     

In vivo proton magnetic resonance spectroscopy (MRS) and single photon emission computerized tomography (SPECT) in systemic lupus erythematosus (SLE)

Neuropsychiatric involvement in SLE (NP-SLE) may not be picked up by routine neuroimaging procedures like computerized tomography (CT) or magnetic resonance imaging (MRI). We prospectively studied the role of single photon emission computerized tomography (SPECT) and magnetic resonance spectroscopy (MRS) in detection of NP-SLE in 20 patients with lupus (10 with clinical NP involvement and 10 without) and 9 healthy controls. MRI abnormalities were seen in 5/10 patients with NP-SLE while the MRI was normal in all the lupus patients without clinical NP involvement. Perfusion defects on SPECT were seen in as many as 8/10 patients with NP-SLE while only 1/10 lupus patients without clinical NP involvement and none of the healthy controls demonstrated perfusion defects. MRS revealed abnormal metabolite ratios in all patients with NP-SLE and as many as 8 lupus patients without clinical NP features. Normal metabolite ratios were observed in healthy controls. SPECT and MRS can help detect changes not evident on MRI and may serve as useful supplements to existing neuroimaging techniques in the diagnosis of NP-SLE. The precise significance of alterations in regional cerebral blood flow on SPECT and neurometabolite ratios on MRS needs larger, longitudinal studies.     

BOOK REVIEWS

Book reviewed in this article: Experimenting with Air and Water: S. Wali Abdi, Editor Charles L. Price Young Children Continue to Reinvent Arithmetic—3rd Grade: Implications of Piaget's Theory: Constance Kamii Sally Jones Livingston Bill Blubaugh     

The Virginia State Systemic Initiative: A Brief Overview of the Lead Teacher Component and a Description of the Evolving Mathematics & Science Integration Outcomes

This article describes the Lead Teacher Component of the NSF-funded State Systemic Initiative, Virginia's Quality Education in Science and Technology (V-QUEST). Part of V-QUEST focuses on the integration of mathematics and science in elementary and middle schools. Some recent research findings and recommendations which informed the planning and decisions are cited. The article describes the guiding principles, objectives, strategies, and agencies involved in the project. An outline of how the integration of mathematics and science elements were developed is provided and some preliminary outcomes are catalogued. An important feature of the systemic project is the manner through which it includes a wide range of individuals and organizations concerned with education in all the planning and implementation phases.