1,584 research outputs found
Does the galaxy correlation length increase with the sample depth?
We have analyzed the behavior of the correlation length, , as a function
of the sample depth by extracting from the CfA2 redshift survey volume--limited
samples out to increasing distances. For a fractal distribution, the value of
would increase with the volume occupied by the sample. We find no linear
increase for the CfA2 samples of the sort that would be expected if the
Universe preserved its small scale fractal character out to the distances
considered (60--100\hmpc). The results instead show a roughly constant value
for as a function of the size of the sample, with small fluctuations due
to local inhomogeneities and luminosity segregation. Thus the fractal picture
can safely be discarded.Comment: Accepted for publication in ApJ
Percutaneous Endoscopic Gastrostomy in the Super-Morbidly Obese Patient
INTRODUCTION: Obesity is reaching epidemic proportions in the United States, and as patients at the extremes of morbid obesity come under the care of surgeons, routine procedures may become increasingly complex in the face of greater body mass. We prospectively evaluated the success rate of percutaneous endoscopic gastrostomy (PEG) placement in a group of morbidly obese patients outside the current classification systems used to stratify obesity.
METHODS: Patients with a body mass index (BMI) greater than 60 kg/m2 who presented for PEG over a one year period were prospectively enrolled. Each patient underwent attempted PEG placement using the pull method by a single surgeon. Outcome variables included: successful PEG, wound infection, tube dislodgement, or bleeding.
RESULTS: Six patients with BMI \u3e 60 kg/m2 presented for PEG. All patients were in a surgical critical care unit maintained on mechanical ventilation. All underwent successful PEG placement with standard techniques and sustained no post-procedural complications.
CONCLUSION: In the hands of an experienced surgical endoscopist, percutaneous endoscopic gastrostomy can be safely performed in patients at the extremes of morbid obesity. Future studies are warranted to validate the results of our small series
Manejo integrado da broca-do-olho-do-coqueiro Rhynchophorus palmarum L. (Coleoptera: Curculionidae).
O gênero Rhynchophorus é relatado causando dano em palmeiras em quase toda a região tropical do Planeta. Três espécies ocorrem nas Américas: R. cruentatus na Florida, costa sudeste dos Estados Unidos e Bahamas; R. palmarum no México, Américas Central e do Sul, e sul das Antilhas; e R. ritcheri no Peru (GIBLIN-DAVIS et al., 2013).bitstream/item/125475/1/Cot-141.pd
Aspectos biolĂłgicos e manejo da Cochonilha-transparente aspidiotus destructor e do PulgĂŁo-preto Cerataphis Lataniae em coqueiro.
bitstream/item/142578/1/cot-177.1pdf.pd
Primordial fractal density perturbations and structure formation in the Universe: 1-Dimensional collisionless sheet model
Two-point correlation function of galaxy distribution shows that the
structure in the present Universe is scale-free up to a certain scale (at least
several tens Mpc), which suggests that a fractal structure may exist. If small
primordial density fluctuations have a fractal structure, the present
fractal-like nonlinear structure below the horizon scale could be naturally
explained. We analyze the time evolution of fractal density perturbations in
Einstein-de Sitter universe, and study how the perturbation evolves and what
kind of nonlinear structure will come out. We assume a one-dimensional
collisionless sheet model with initial Cantor-type fractal perturbations. The
nonlinear structure seems to approach some attractor with a unique fractal
dimension, which is independent of the fractal dimensions of initial
perturbations. A discrete self-similarity in the phase space is also found when
the universal nonlinear fractal structure is reached.Comment: 17 pages, 19 jpeg figures. Accepted for publication in ApJ. Figures
are also available from
http://www.phys.waseda.ac.jp/gravity/~tatekawa/0003124/figs.tar.g
Theoretical correlation between possible evidences of neutrino chiral oscillations and polarization measurements
Reporting about the formalism with the Dirac equation we describe the
dynamics of chiral oscillations for a fermionic particle non-minimally coupling
with an external magnetic field. For massive particles, the chirality and
helicity quantum numbers represent different physical quantities of
representative importance in the study of chiral interactions, in particular,
in the context of neutrino physics. After solving the interacting Hamiltonian
(Dirac) equation for the corresponding {\em fermionic} Dirac-{\em type}
particle (neutrino) and quantifying chiral oscillations in the Dirac wave
packet framework, we avail the possibility of determining realistic neutrino
chirality conversion rates by means of (helicity) polarization measurements. We
notice that it can become feasible for some particular magnetic field
configurations with large values of {\boldmath} orthogonal to the direction
of the propagating particle.Comment: 12 pages, 2 figure
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