Protonospheric electron concentration profiles Final report

Protonospheric electron concentration profiles based on Doppler and Faraday effect

CVD of CrO2 Thin Films: Influence of the Deposition Parameters on their Structural and Magnetic Properties

This work reports on the synthesis of CrO2 thin films by atmospheric pressure CVD using chromium trioxide (CrO3) and oxygen. Highly oriented (100) CrO2 films containing highly oriented (0001) Cr2O3 were grown onto Al2O3(0001) substrates. Films display a sharp magnetic transition at 375 K and a saturation magnetization of 1.92 Bohr magnetons per f.u., close to the bulk value of 2 Bohr magnetons per f.u. for the CrO2. Keywords: Chromium dioxide (CrO2), Atmospheric pressure CVD, Spintronics.Comment: 5 pages, 6 figure

Scaling of variables and the relation between noncommutative parameters in Noncommutative Quantum Mechanics

We consider Noncommutative Quantum Mechanics with phase space noncommutativity. In particular, we show that a scaling of variables leaves the noncommutative algebra invariant, so that only the self-consistent effective parameters of the model are physically relevant. We also discuss the recently proposed relation of direct proportionality between the noncommutative parameters, showing that it has a limited applicability.Comment: Revtex4, 4 pages; version to match the published on

Mycobiota and mycotoxins present in finished fish feeds from farms in the Rio de Janeiro State, Brazil

The aim of the present study was to determine species of the fungal genera Aspergillus, Fusarium, and Penicillium and fumonisin B1 (FB1), aflatoxin B1 (AFB1), and ochratoxin A (OTA) contamination from feed intended for fish farms. A total of 60 samples were sampled from tilapia farms in the Rio de Janeiro State, Brazil. The quantitative enumeration of fungi as colony-forming units per gram of feed (CFU/g) was performed using the surface spread method in different culture media. The results were expressed as fungal isolation frequency and relative density. Fungal total counts ranged from <1 × 102 to 4.7 × 104 CFU/g. Fusarium counts were not observed. Among toxigenic genera, Aspergillus (68%) was the most prevalent, followed by Penicillium species (60%). Aspergillus niger aggregate (36%), Aspergillus flavus (35%), and Penicillium citrinum (71%) were the most prevalent species. A high percentage of samples (98%) were contaminated with FB1 levels, while 55% and 3.3% were contaminated with AFB1 and OTA, respectively. The simultaneous occurrence of these mycotoxins emphasizes the need for further research in the area to better assess the risk to the health of fish farms and their implications for the health of consumers of this meat.Fil: Barbosa, Tatiana S.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Pereyra, Carina Maricel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Soleiro, Carla A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Dias, Erica O.. Universidade Federal Rural do Rio de Janeiro ; BrasilFil: Oliveira, Aguida A.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Keller, Kelly M.. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; BrasilFil: Silva, Pedro P. O.. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural do Rio de Janeiro ; Brasil. Conselho Nacional de Desenvolvimiento Científico y Tecnológico; Brasi

Interaction effects on galaxy pairs with Gemini/GMOS- II: Oxygen abundance gradients

In this paper we derived oxygen abundance gradients from HII regions located in eleven galaxies in eight systems of close pairs. Long-slit spectra in the range 4400-7300A were obtained with the Gemini Multi-Object Spec- trograph at Gemini South (GMOS). Spatial profiles of oxygen abundance in the gaseous phase along galaxy disks were obtained using calibrations based on strong emission-lines (N2 and O3N2). We found oxygen gradients signifi- cantly flatter for all the studied galaxies than those in typical isolated spiral galaxies. Four objects in our sample, AM1219A, AM1256B, AM 2030A and AM2030B, show a clear break in the oxygen abundance at galactocentric radius R/R25 between 0.2 and 0.5. For AM1219A and AM1256B we found negative slopes for the inner gradients, and for AM2030B we found a positive one. In all these three cases they show a flatter behaviour to the outskirts of the galaxies. For AM2030A, we found a positive-slope outer gradient while the inner one is almost compatible with a flat behaviour. A decrease of star forma- tion efficiency in the zone that corresponds to the oxygen abundance gradient break for AM1219A and AM2030B was found. For the former, a minimum in the estimated metallicities was found very close to the break zone that could be associated with a corotation radius. On the other hand, AM1256B and AM2030A, present a SFR maximum but not an extreme oxygen abundance value. All the four interacting systems that show oxygen gradient breakes the extreme SFR values are located very close to break zones. Hii regions lo- cated in close pairs of galaxies follow the same relation between the ionization parameter and the oxygen abundance as those regions in isolated galaxies.Comment: 30 pages, 14 figures, accepted MNRAS, (Figs. 1 and 2 are in low resolution

Multiple Mineralocorticoid Response Elements Localized in Different Introns Regulate Intermediate Conductance K+ (Kcnn4) Channel Expression in the Rat Distal Colon

An elevated plasma aldosterone and an increased expression of the intermediate conductance K+ (IK/Kcnn4) channels are linked in colon. This observation suggests that the expression of Kcnn4 gene is controlled through the action of aldosterone on its cognate receptor (i.e., mineralocorticoid receptor; MR). In order to establish this, we performed chromatin immunoprecipitation (ChIP) assay to identify the MR response elements (MREs) in a region that spanned 20 kb upstream and 10 kb downstream of the presumed transcription start site (TSS) using chromatin from the colonic epithelial cells of normal and aldosterone-treated rats. MREs were immunoprecipitated in an approximately 5 kb region that spanned the first and second introns in the aldosterone rats. These regions were individually cloned in luciferase-expression vector lacking enhancer activity. These clones were tested for enhancer activity in vitro by transfecting in HEK293T and CaCo2 cells with MR and aldosterone treatment. At least four regions were found to be responsive to the MR and aldosterone. Two regions were identified to contain MREs using bioinformatics tools. These clones lost their enhancer activity after mutation of the presumptive MREs, and thus, established the functionality of the MREs. The third and fourth clones did not contain any bioinformatically obvious MREs. Further, they lost their activity upon additional sub-cloning, which suggest cooperativity between the regions that were separated upon sub-cloning. These results demonstrate the presence of intronic MREs in Kcnn4 and suggest a highly cooperative interaction between multiple intronic response elements

A self-consistent test of Comptonization models using a long BeppoSAX observation of NGC 5548

We test accurate models of Comptonization spectra over the high quality data of the BeppoSAX long look at NGC 5548. The data are well represented by a plane parallel corona with an inclination angle of 30$^{\circ}$, a soft photon temperature of 5 eV and a hot plasma temperature and optical depth of $kT_{\rm e}\simeq$ 360 keV and $\tau\simeq$ 0.1, respectively. If energy balance applies, such values suggest that a more ``photon-starved'' geometry (e.g. a hemispheric region) is necessary. The spectral softening detected during a flare, appears to be associated to a decrease of the heating-to-cooling ratio, indicating a geometric and/or energetic modification of the disk plus corona system. The hot plasma temperature derived with the models above is significantly higher than that obtained fitting the same data with a power law plus high energy cut off model for the continuum. This is due to the fact that in anisotropic geometries Comptonization spectra show "intrinsic" curvature which moves the fitted high energy cut-off to higher energies.Comment: 4 pages, 2 figures, to appear in the proceedings of the conference "X-ray Astronomy '99", Bologna, Italy, September 199

Grain Sorghum Response to Band Applied Zinc Fertilizer

Zinc (Zn) is one of the micronutrients found to be deficient in Kansas. The objective of this study was to evaluate the response of grain sorghum to Zn fertilization using strip trials. The experiment was set up in Manhattan, KS, in 2015. The experimental design consisted of two strips, one with Zn fertilizer and the other without, with five replications. Zn fertilizer was applied as starter in combination with ammonium polyphosphate at the rate of 0.5 lb Zn/a. Plant tissue samples were collected to determine Zn content. Grain yield was recorded by combine equipped with yield monitor. No significant differences were found for sorghum grain yield. Grain Zn content increased with Zn fertilization. Zn fertilization may be considered for future studies in food biofortification