5,677 research outputs found
Interferometric Detection of Planets/Gaps in Protoplanetary Disks
We investigate the possibility to find evidence for planets in circumstellar
disks by infrared and submillimeter interferometry. Hydrodynamical simulations
of a circumstellar disk around a solar-type star with an embedded planet of 1
Jupiter mass are presented. On the basis of 3D radiative transfer simulations,
images of this system are calculated. These intensity maps provide the basis
for the simulation of the interferometers VLTI (equipped with the mid-infrared
instrument MIDI) and ALMA. While ALMA will provide the necessary basis for a
direct gap and therefore indirect planet detection, MIDI/VLTI will provide the
possibility to distinguish between disks with or without accretion on the
central star on the basis of visibility measurements.Comment: 4 pages, TeX (or Latex, etc); to appear in proceedings of "Scientific
Frontiers in Research on Extrasolar Planets
Operator product expansions as a consequence of phase space properties
The paper presents a model-independent, nonperturbative proof of operator
product expansions in quantum field theory. As an input, a recently proposed
phase space condition is used that allows a precise description of point field
structures. Based on the product expansions, we also define and analyze normal
products (in the sense of Zimmermann).Comment: v3: minor wording changes, as to appear in J. Math. Phys.; 12 page
Detecting planets in protoplanetary disks: A prospective study
We investigate the possibility to find evidence for planets in circumstellar
disks by infrared and submillimeter interferometry. We present simulations of a
circumstellar disk around a solar-type star with an embedded planet of 1
Jupiter mass. The three-dimensional (3D) density structure of the disk results
from hydrodynamical simulations. On the basis of 3D radiative transfer
simulations, images of this system were calculated. The intensity maps provide
the basis for the simulation of the interferometers VLTI (equipped with the
mid-infrared instrument MIDI) and ALMA. While MIDI/VLTI will not provide the
possibility to distinguish between disks with or without a gap on the basis of
visibility measurements, ALMA will provide the necessary basis for a direct gap
detection.Comment: 5 page
Statistical Modeling of Epistasis and Linkage Decay using Logic Regression
Logic regression has been recognized as a tool that can identify and model non-additive genetic interactions using Boolean logic groups. Logic regression, TASSEL-GLM and SAS-GLM were compared for analytical precision using a previously characterized model system to identify the best genetic model explaining epistatic interaction for vernalization-sensitivity in barley. A genetic model containing two molecular markers identified in vernalization response in barley was selected using logic regression while both TASSEL-GLM and SAS-GLM included spurious associations in their models. The results also suggest the logic regression can be used to identify dominant/recessive relationships between epistatic alleles through its use of conjugate operators
Surgical Approach of Synchronous Medullary Thyroid Carcinoma and Pheochromocytoma in MEN 2 Syndrome
In cases with concurrent medullary thyroid carcinoma (MTC) and pheochromocytoma, discussion regarding a one-stage versus two-stage treatment strategy approach remains open. From 1975 to 1990, 11 of 25 multiple endocrine neoplasia type 2 (MEN 2) patients presented with biendocrinopathies or triendocrinopathies synchronously. All patients were treated surgically and followed subsequently in our hospital. Of the group of nine patients with concurrent MTC and pheochromocytoma, five were treated in one-stage and four in two-stage procedures. No patient had major complications intraoperatively. For the two-stage group, the total hospital stay (preoperatively and postoperatively) averaged 35 days. For the one-stage group, the total hospital stay averaged 25 days. In patients with increased operative risks (patients with higher age and impaired physical condition or if neck surgery includes transstemal cervicomediastinal lymphadenectomy), two-stage procedures should be selected. However, in young patients with the MEN 2 syndrome or syndromes with small tumors detected by family screening, thyroidectomy, cervical lymphadenectomy, and adrenalectomy may be performed in a one-stage procedure without increasing surgically related morbidity
Estsitalopraami efektiivsus depressiooni ravis võrrelduna konventsionaalsete selektiivsete serotoniini tagasihaarde inhibiitorite ja venlafaksiin XRiga: metaanalüüs
Estsitalopraam on kõige selektiivsem selektiivsete serotoniini tagasihaarde inhibiitorite rühma kuuluv antidepressant. Varasemad uuringud on näidanud, et estsitalopraam on oma toimelt tõhusam kui tsitalopraam. Artiklis on antud ülevaade metaanalüüsi uuringutest, milles estsitalopraami võrreldi teiste antidepressantidega (tsitalopraam, fluoksetiin, paroksetiin, sertraliin ja venlafaksiin XR). Estsitalopraam oli efektiivsem kui kõik teised võrdlusravimid nii üldise raviefekti, ravile reageerimise määra kui ka remissiooni saavutamise määra poolest. Eri ravimirühmade analüüs näitas, et estsitalopraam oli oluliselt tõhusam kui konventsionaalsed SSRId ja võrdväärne venlafaksiiniga, ehkki uuringu üldised tulemused ei näita tingimata, et estsitalopraam oleks oluliselt efektiivsem kui iga SSRI eraldi. Sarnased tulemused leiti ka raske depressiooniga patsientide seas.
Eesti Arst 2006; 85 (11): 739–75
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Physics with energetic radioactive ion beams
Beams of short-lived, unstable nuclei have opened new dimensions in studies of nuclear structure and reactions. Such beams also provide key information on reactions that take place in our sun and other stars. Status and prospects of the physics with energetic radioactive beams are summarized
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