48 research outputs found
Aspectos biológicos de fêmeas adultas de Orius insidiosus (SAY, 1832) (HEMIPTERA: ANTHOCORIDAE) alimentadas com diferentes densidades de Aphis gossypii (GLOVER, 1877) (HEMIPTERA: APHIDIDAE)
Orius insidiosus (SAY, 1832) é uma espécie de predador importante para programas de controle biológico
INTERLAYER COUPLING AND THE METAL-INSULATOR TRANSITION IN Pr-SUBSTITUTED Bi(2)Sr(2)CaCu(2)O(8+y)
Substitution of rare-earth ions for Ca in Bi2Sr2CaCu2O8+y is known to cause a
metal-insulator transition. Using resonant photoemission we study how this
chemical substitution affects the electronic structure of the material. For the
partial Cu-density of states at E_F and in the region of the valence band we
observe no significant difference between a pure superconducting sample and an
insulating sample with 60% Pr for Ca. This suggests that the states responsible
for superconductivity are predomi- nately O-states. The partial Pr-4f density
of states was extracted utilizing the Super- Koster-Kronig Pr 4d-4f resonance.
It consists of a single peak at 1.36eV binding energy. The peak shows a
strongly assymetric Doniach-Sunjic line- shape indicating the presence of a
continuum of electronic states with sharp cut off at E_F even in this
insulating sample. This finding excludes a bandgap in the insulating sample and
supports the existance of a mobility gap caused by spatial localization of the
carriers. The presence of such carriers at the Pr-site, between the CuO_2
planes shows that the electronic structure is not purely 2-dimensional but that
there is a finite interlayer coupling. The resonance enhancement of the
photoemission cross section, at the Pr-4d threshold, was studied for the Pr-4f
and for Cu-states. Both the Pr-4f and the Cu-states show a Fano-like resonance.
This resonance of Cu-states with Pr-states is another indication of coupling
between the the Pr-states and those in the CuO_2 plane. Because of the
statistical distribution of the Pr-ions this coupling leads to a non-periodic
potential for the states in the CuO_2 plane which can lead to localization and
thus to the observed metal-insulator transition.Comment: Gziped uuencoded postscript file including 7 figures Scheduled for
publication in Physical Review B, May 1, 1995
Walking execution is not affected by divided attention in patients with multiple sclerosis with no disability, but there is a motor planning impairment
Influência de genótipos de couve (Brassica oleracea L. var. acephala DC.) na biologia de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae)
Efeito de beauveria bassiana (bals.) Vuillemin e Metarhizium anisopliae (metsch.) sorokin nos parâmetros biológicos de trichogramma atopovirilia oatman & platner, 1983 (hymenoptera: trichogrammatidae)
Hypoglossal nerve trunk stimulation: electromyography findings during drug-induced sleep endoscopy: a case report
Abstract Background Literature has demonstrated hypoglossal nerve stimulation to be a safe and effective treatment for patients with obstructive sleep apnea nonadherent to positive airway pressure therapy. However, the recommended criteria for patient selection are still unable to identify all the unresponsive patients, highlighting the need for improved understanding about hypoglossal nerve stimulation for obstructive sleep apnea. Case presentation A 48-year-old Caucasian male patient with obstructive sleep apnea had been successfully treated with electrical stimulation of the hypoglossal nerve trunk, documented by level 1 polysomnography data. However, due to snoring complaints, he underwent postoperation drug-induced sleep endoscopy for evaluation of electrode activation during upper airway collapse, aiming to improve electrostimulation parameters. Concurrent surface electromyography of the suprahyoid muscles and masseter was obtained. Activation of electrodes 2, 3, and 6 promoted upper airway opening most strongly at the velopharynx and tongue base during drug-induced sleep endoscopy. The same channels also significantly increased the electrical activity on suprahyoid muscles bilaterally, but predominantly on the stimulated side (right). The masseters also presented a considerable asymmetry in electrical potential on the right side (> 55%). Conclusion Beyond the genioglossus muscle, our findings demonstrate recruitment of other muscles during hypoglossal nerve stimulation, which may be attributed to the electrical stimulation of the nerve trunk. This data provides new insights on how stimulation of the hypoglossal nerve trunk may contribute to obstructive sleep apnea treatment