2,729 research outputs found
Controlled nucleation of topological defects in the stripe domain patterns of Lateral multilayers with Perpendicular Magnetic Anisotropy: competition between magnetostatic, exchange and misfit interactions
Magnetic lateral multilayers have been fabricated on weak perpendicular
magnetic anisotropy amorphous Nd-Co films in order to perform a systematic
study on the conditions for controlled nucleation of topological defects within
their magnetic stripe domain pattern. A lateral thickness modulation of period
is defined on the nanostructured samples that, in turn, induces a lateral
modulation of both magnetic stripe domain periods and average
in-plane magnetization component . Depending on lateral multilayer
period and in-plane applied field, thin and thick regions switch independently
during in-plane magnetization reversal and domain walls are created within the
in-plane magnetization configuration coupled to variable angle grain boundaries
and disclinations within the magnetic stripe domain patterns. This process is
mainly driven by the competition between rotatable anisotropy (that couples the
magnetic stripe pattern to in-plane magnetization) and in-plane shape
anisotropy induced by the periodic thickness modulation. However, as the
structural period becomes comparable to magnetic stripe period ,
the nucleation of topological defects at the interfaces between thin and thick
regions is hindered by a size effect and stripe domains in the different
thickness regions become strongly coupled.Comment: 10 pages, 7 figures, submitted to Physical Review
Double percolation effects and fractal behavior in magnetic/superconducting hybrids
Perpendicular magnetic anisotropy ferromagnetic/ superconducting (FM/SC)
bilayers with a labyrinth domain structure are used to study nucleation of
superconductivity on a fractal network, tunable through magnetic history. As
clusters of reversed domains appear in the FM layer, the SC film shows a
percolative behavior that depends on two independent processes: the arrangement
of initial reversed domains and the fractal geometry of expanding clusters. For
a full labyrinth structure, the behavior of the upper critical field is typical
of confined superconductivity on a fractal network.Comment: 15 pages, 5 figure
Correlations Between Parental Inbred Lines and Derived Hybrid Performance for Grain Filling Traits in Maize
Individual kernel weight (KW) is largely genetically determined, and its variability is achieved through different combinations of rate and duration of kernel growth. Genetic variability for grain-filling patterns has been observed among inbred lines and commercial hybrids, and there is current interest on dissecting its genetic basis. However, suitable grain filling phenotyping protocols are still to be determined, such as the value to study traits at the inbred or hybrid levels. The objective of our study was to evaluate the correlation between parental inbred line and derived hybrid performance for several grain-filling traits in maize (Zea mays L.). We hypothesized that there would be high correlations due to the relative high heritability of grainfilling traits. Three trials were conducted (two in Argentina and one in the United States) with commercial relevant germplasm (totaling 25 parental inbreds and 31 single-cross hybrids). Traits were KW, kernel growth rate (KGR), grainfilling duration (GFD), maximum water content (MWC), moisture concentration at physiological maturity (MCPM), and kernel desiccation rate (KDR) during the effective grain filling. Both heterosis and correlations between midparental value and hybrid performance were significant (p < 0.05) for all traits (r values of 0.63, 0.71, 0.81, 0.83, 0.61, and 0.71 for KW, KGR, GFD, MWC, KDR, and MCPM, respectively). Our results confirm that studying inbred lines for grain-filling traits generates valuable information for derived hybrid performanceFil: Alvarez Prado, Santiago. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Producción Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gambin, Brenda Laura. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Producción Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Novoa, A. Daniel. Nidera S. A; ArgentinaFil: Foster, Daniel. Syngenta Seeds; Estados UnidosFil: Senior, M. Lynn. Syngenta Biotechnology,; Estados UnidosFil: Zinselmeier, Christopher. Syngenta Seeds; Estados UnidosFil: Otegui, Maria Elena. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Borras, Lucas. Universidad Nacional de Rosario. Facultad de Cs.agrarias. Departamento de Producción Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Global impact of diet and temperature over aquaculture of Octopus vulgaris paralarvae from a transcriptomic approach
Common octopus, Octopus vulgaris, is an economically important cephalopod species. However, its rearing under captivity is currently challenged by massive mortalities previous to their juvenile stage due to nutritional and environmental factors. Dissecting the genetic basis and regulatory mechanism behind this mortality requires genomic background knowledge. A transcriptomic sequencing of 10 dph octopus paralarvae from different experimental conditions was constructed via RNA-seq. A total of 613,767,530 raw reads were filtered and de novo assembled into 363,527 contigs of which 82,513 were annotated in UniProt carrying also their GO and KEGG information. Differential gene expression analysis was carried out on paralarvae reared under different diet regimes and temperatures, also including wild paralarvae. Genes related to lipid metabolism exhibited higher transcriptional levels in individuals whose diet includes crustacean zoeas, which had an impact over their development and immune response capability. High temperature induces acclimation processes at the time that increase metabolic demands and oxidative stress. Wild individuals show an expression profile unexpectedly similar to Artemia fed individuals. Proteomic results support the hypothesis revealed by transcriptional analysis. The comparative study of the O. vulgaris transcriptomic profiles allowed the identification of genes that deserve to be further studied as candidates for biomarkers of development and health. The results obtained here on the transcriptional variations of genes caused by diet and temperature will provide new perspectives in understanding the molecular mechanisms behind nutritional and temperature requirements of common octopus that will open new opportunities to deepen in paralarvae rearing requirements.Versión del edito
Magnetic order and disorder in nanomagnets probed by superconducting vortices
We have studied two nanomagnet systems with strong (Co/Pd multilayers) and
weak (NdCo alloy films) stray magnetic fields by probing the out-of-plane
magnetic states with superconducting vortices. The hybrid samples are made of
array of nanomagnets embedded in superconducting Nb thin films. The vortex
motion detects relevant magnetic state features, since superconducting vortices
are able to discriminate between different magnetic stray field strengths and
directions. The usual matching effect between the superconducting vortex
lattice and the periodic pinning array can be quenched by means of disorder
magnetic potentials with strong stray fields at random. Ordered stray fields
retrieve the matching effect and yield asymmetry and shift in the vortex
dissipation signal. Furthermore vortices can discriminate the sizes of the
nanomagnet magnetic domains, detecting magnetic domain sizes as small as 70 nm.
In addition, we observe that the vortex cores play the crucial role instead of
the supercurrents around the vortex.Comment: 22 pages, 8 figure
Reconstruction of Longitudinal Profiles of Ultra-High Energy Cosmic Ray Showers from Fluorescence and Cherenkov Light Measurements
We present a new method for the reconstruction of the longitudinal profile of
extensive air showers induced by ultra-high energy cosmic rays. In contrast to
the typically considered shower size profile, this method employs directly the
ionization energy deposit of the shower particles in the atmosphere. Due to
universality of the energy spectra of electrons and positrons, both
fluorescence and Cherenkov light can be used simultaneously as signal to infer
the shower profile from the detected light. The method is based on an analytic
least-square solution for the estimation of the shower profile from the
observed light signal. Furthermore, the extrapolation of the observed part of
the profile with a Gaisser-Hillas function is discussed and the total
statistical uncertainty of shower parameters like total energy and shower
maximum is calculated.Comment: accepted by NIM
Dengue 3 Epidemic, Havana, 2001
In June 2001, dengue transmission was detected in Havana, Cuba; 12,889 cases were reported. Dengue 3, the etiologic agent of the epidemic, caused the dengue hemorrhagic fever only in adults, with 78 cases and 3 deaths. After intensive vector control efforts, no new cases have been detected
- …