Magnetic and Structural Studies of the Quasi-Two-Dimensional Spin-Gap System (CuCl)LaNb2O7

We report magnetization, nuclear magnetic resonance (NMR), nuclear quadrupole resonance (NQR), and transmission electron microscopy (TEM) studies on the quasi-two-dimensional spin-gap system (CuCl)LaNb2O7, a possible candidate for the J1-J2 model on a square lattice. A sharp single NQR line is observed at the Cu and Cl sites, indicating that both Cu and Cl atoms occupy a unique site. However, the electric field gradient tensors at the Cu, Cl, and La sites do not have axial symmetry. This is incompatible with the reported crystal structure. Thus the J1-J2 model has to be modified. We propose alternative two-dimensional dimer models based on the NMR, NQR, and TEM results. The value of the hyperfine coupling constant at the Cu sites indicates that the spin density is mainly on the d(3z2-r2) orbital (z parallel c). At 1.5 K, Cu- and Nb-NMR signals disappear above the critical field Bc1 = 10.3 T determined from the onset of the magnetization, indicating a field-induced magnetic phase transition at Bc1.Comment: 9 pages, 16 figure

Characterization Studies and Yield Attributes of Some Varieties of Cowpea (\u3cem\u3eVigna unguiculata\u3c/em\u3e L.)

Investigations were carried out on sixteen improved varieties of cowpea (Vigna unguiculata L walp) obtained from International Institute for Tropical Agriculture, Ibadan. These varieties were grown in the Department of Biological Sciences Garden, of the University of Ilorin. Qualitative and quantitative characters were observed for the study. Positive correlations were obtained between leaf number and stem diameter, leaf number and number of seeds per pod, number of branches and plant height. Negative correlation existed between number of pods per plant and number of seed per pod. Analysis of variance (ANOVA) showed significant difference in all the quantitative characters analyzed among the varieties. Each character was also analyzed using Duncan test and F-LSD. The result showed that IT99K-529-1, IT99K – 429 – 2, IT97K – 461 – 4, IT98K – 506 – 1 and IT99K- 1122 were outstanding in term of vegetative and yield performances in Ilorin, Kwara State of Nigeria

The Power of Ideas : Reflections on the Legacy of Brown v. Board of Education and the American Experience

departmental bulletin pape

AIR TEMPERATURE AND SUNLIGHT INTENSITY OF DIFFERENT GROWING PERIOD AFFECTS THE BIOMASS, LEAF COLOR AND BETACYANIN PIGMENT ACCUMULATIONS IN RED AMARANTH (AMARANTHUS TRICOLOR L.)

The objectives of this study were to determine the effects of daily air temperature and sunlight intensity variations on biomass production, leaf color and betacyanin accumulations in red amaranth (Amaranthus tricolor L.). For this purpose, two improved cultivars; BARI-1 and Altopati were grown in seven different period (from April to October, 2006) under vinyl house condition in the experimental facilities of Gifu University, Japan. The mean daily temperatures fluctuated from 18 (growing month- April) to 29ºC (August), while the mean sunlight intensities varied from 850 (October) to 1257 μmol m-2 S-1 (August). The highest biomass yield and betacyanin accumulation was obtained in the warmer growing period (July and August) at 28 to 29ºC mean air temperatures and 1240 to 1257 μmol m-2 S-1 sunlight intensity. At the warmer growing period red amaranth produced red leaves with high color index, which enhanced the betacyanin accumulations. The biomass yield and betacyanin accumulations were reduced significantly in the growing period/month April and October under low temperature regimes (mean air temperature 18 and 19ºC, respectively). However, growing period’s air temperature contributed more for biomass and betacyanin accumulations in red amaranth than sunlight intensity. Comparing two cultivars the biomass yield of BARI-1 was higher biomass yield than that of Altopati and Altopati highlighted with the higher betacyanin accumulations than that of BARI-1 in all growing period. Quantification of the effects of daily air temperature and sunlight intensity on biomass and betacyanin accumulation is important for growers producing these crops for fresh market and also optimize the best growing period. Therefore the influence of air temperatures and sunlight intensity should be considered while grown red amaranth for maximum yield with bioactive compounds like betacyanin and should be grown in between 28 to 29ºC air temperature and 1240 to 1257 μmol.m-2.S-1. of sunlight intensity

Aspectos morfométricos do tubo digestório de pacu (Piaractus mesopotamicus) submetidos à privação alimentar.

Resumo 658-2. 24º Reunião Anual da FeSBE

Respostas hematológicas de Arapaima gigas (Pisces: Arapaimidae) parasitados naturalmente por protozoários e metazoários.

O presente estudo comparou os parâmetros sanguíneos de Arapaima gigas Schinz, 1822 de cultivo, parasitados por uma espécie de protozoário e três espécies de helmintos. Em uma das pisciculturas os peixes foram parasitados somente por Ichthyophthirius multifiliis (Ciliophora), enquanto na outra foram parasitados por I. multifiliis, Dawestrema cycloancistrium e Dawestrema cycloancistrioides (Monogenoidea) e Polyacanthorhynchus macrorhynchus (Acanthocephala). Determinou-se a contagem total de eritrócitos , trombócitos e leucócitos (total e diferencial), hematócrito, concentração de hemoglobina, volume corpuscular média (VCM), hemoglobina corpuscular média (HCM), concentração da hemoglobina corpuscular média (CHCM), glicose e proteínas totais. Os peixes parasitados por I. multifiliis, D. cycloancistrium, D. cycloancistrioides e P. macrorhynchus mostraram menores valores de hematócrito, VCM e níveis de glicose, e maior concentração de hemoglobina, HCM, CHCM, número de eritrócitos , monócitos , neutrófilos e eosinófilos totais quando comparados aos peixes parasitados somente por I. multifiliis. Portanto, esses resultados indicam uma resposta desses parâmetr os sanguíneos ao parasitismo em A. gigas