220 research outputs found
Inflation after WMAP3
I discuss the current status of inflationary cosmology in light of the recent
WMAP 3-year data release. The basic predictions of inflation are all supported
by the data. Inflation also makes predictions which have not been well tested
by current data but can be by future experiments, most notably a deviation from
a scale-invariant power spectrum and the production of primordial gravitational
waves. A scale-invariant spectrum is disfavored by current data, but not
conclusively. Tensor modes are currently poorly constrained, and slow-roll
inflation does not make an unambiguous prediction of the expected amplitude of
primordial gravitational waves. A tensor/scalar ratio of is
within reach of near-future measurements.Comment: To appear in the proceedings of Colliders to Cosmic Rays 2007. 8
pages, 2 figures. (V2: Minor typo corrected
The Geometry and Ionization Structure of the Wind in the Eclipsing Nova-like Variables RW Tri and UX UMa
The UV spectra of nova-like variables are dominated by emission from the
accretion disk, modified by scattering in a wind emanating from the disk. Here
we model the spectra of RW Tri and UX UMa, the only two eclipsing nova-likes
which have been observed with the Hubble Space Telescope in the
far-ultraviolet, in an attempt to constrain the geometry and the ionization
structure of their winds. Using our Monte Carlo radiative transfer code we
computed spectra for simply-parameterized axisymmetric biconical outflow models
and were able to find plausible models for both systems. These reproduce the
primary UV resonance lines - N V, Si IV, and C IV - in the observed spectra in
and out of eclipse. The distribution of these ions in the wind models is
similar in both cases as is the extent of the primary scattering regions in
which these lines are formed. The inferred mass loss rates are 6% to 8% of the
mass accretion rates for the systems. We discuss the implication of our point
models for our understanding of accretion disk winds in cataclysmic variables.Comment: 13 pages, 15 figures and 4 tables. Published in Ap
Untersuchungen zur Hilfsmittelversorgung von Behinderten
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Die Hilfsmittelversorgung von Behinderten weist immer noch Defizite auf: Benutzer beklagen sich über die angebotenen Produkte, die Mißachtung ihrer Bedürfnisse und den mühsamen Weg des Erwerbs von Hilfsmitteln. Auf der anderen Seite sehen sich die Kostenträger außerstande, die Versorgung aufrechtzuerhalten und fordern immer mehr Eigenbeteiligung an den Kosten. Wie kann diese Situation verbessert werden? Anhand von Expertengesprächen und Gesprächen mit Betroffenen sowie der Analyse verschiedener Verfahren zur Bewertung von Behinderung wurde zunächst das Verständnis von Behinderung betrachtet. Danach sind die Schwachstellen tatsächlich benutzter Hilfsmittel untersucht worden. Neben funktionalen Mängeln sind dabei besonders sozio-kulturelle Probleme aufgefallen, die den Hilfsmittelgebrauch erschweren. Das Resultat dieser Untersuchung ist der Vorschlag eines neuen Ansatzes zur Gestaltung von Hilfsmitteln, mit dem eine bessere Versorgung Behinderter vorstellbar wäre. Wie dies aussehen kann, ist am Entwurf einer Steckdose nachvollzogen worden
The influence of selection effects on the observed cataclysmic variable population: modelling and application to the Palomar-Green sample
Large differences between the properties of the known sample of cataclysmic
variable stars (CVs) and the predictions of the theory of binary star evolution
have long been recognised. However, because all existing CV samples suffer from
strong selection effects, observational biases must be taken into account
before it is possible to tell whether there is an inconsistency. In order to
address this problem, we have modelled the impact of selection effects on
observed CV samples using a Monte Carlo approach. By simulating the selection
criteria of the Palomar-Green (PG) Survey, we show that selection effects
cannot reconcile the predictions of standard CV evolution theory with the
observed sample. More generally, we illustrate the effect of the biases that
are introduced by magnitude limits, selection cuts in U-B, and restrictions in
galactic latitude.Comment: 12 pages, 11 figures, minor changes made to the text, accepted for
publication in MNRA
Hyperinsulinaemic hypoglycaemia - a diagnostic challenge. A report of two atypical cases
Objectives: The authors describe 2 atypical cases of patients with hypoglycaemia, suspected for insulinoma.
Methods: The 2 reports are accompanied by a concise review of the literature.
Results: Patient 1 had a distal pancreatectomy performed for suspected insulinoma, and was diagnosed with a glucagonoma and beta-cell hyperplasia (nesidioblastosis). To the authors’s knowledge, co-existing glucagonoma and nesidioblastosis had not been previously reported.
Patient 2 was diagnosed with a benign insulinoma and 5 years later with metastatic disease.
Conclusion: The authors conclude that insulinomas are rare entities which often present a diagnostic and therapeutic challenge. In such cases, patient referral to tertiary multidisciplinary centers is recommended
Somatostatin analogue treatment primarily induce miRNA expression changes and up-regulates growth inhibitory miR-7 and miR-148a in neuroendocrine cells
Somatostatin (SST) analogues are used to control the proliferation and symptoms of neuroendocrine tumors (NETs). MicroRNAs (miRNA) are small non-coding RNAs that modulate posttranscriptional gene expression. We wanted to characterize the miRNAs operating under the control of SST to elucidate to what extent they mediate STT actions. NCI-H727 carcinoid cell line was treated with either a chimeric SST/dopamine analogue; a SST or dopamine analogue for proliferation assays and for identifying differentially expressed miRNAs using miRNA microarray. The miRNAs induced by SST analogue treatment are investigated in carcinoid cell lines NCI-H727 and CNDT2 using in situ hybridization, qPCR and proliferation assays. SST analogues inhibited the growth of carcinoid cells more potently compared to the dopamine analogue. Principal Component Analysis (PCA) of the samples based on miRNA expression clearly separated the samples based on treatment. Two miRNAs which were highly induced by SST analogues, miR-7 and miR-148a, were shown to inhibit the proliferation of NCI-H727 and CNDT2 cells. SST analogues also produced a general up-regulation of the let-7 family members. SST analogues control and induce distinct miRNA expression patterns among which miR-7 and miR-148a both have growth inhibitory properties
(68)Ga-DOTATOC PET and gene expression profile in patients with neuroendocrine carcinomas:strong correlation between PET tracer uptake and gene expression of somatostatin receptor subtype 2
Somatostatin receptor expression on both protein and gene expression level was compared with in vivo (68)Ga-DOTATOC PET/CT in patients with neuroendocrine carcinomas (NEC). Twenty-one patients with verified NEC who underwent a (68)Ga-DOTATOC PET/CT between November 2012 and May 2014, were retrospectively included. By real-time polymerase chain reaction, we quantitatively determined the gene expression of several genes and compared with (68)Ga-DOTATOC PET uptake. By immunohistochemistry we qualitatively studied the expression of assorted proteins in NEC. The median age at diagnosis was 68 years (range 41-84) years. All patients had WHO performance status 0-1. Median Ki67 index was 50% (range 20-100%). Gene expression of somatostatin receptor subtype (SSTR) 2 and Ki67 were both positively correlated to the (68)Ga-DOTATOC uptake (r=0.89; p<0.0001 and r=0.5; p=0.021, respectively). Furthermore, SSTR2 and SSTR5 gene expression were strongly and positively correlated (r=0.57; p=0.006). This study as the first verifies a positive and close correlation of (68)Ga-DOTATOC uptake and gene expression of SSTR2 in NEC. SSTR2 gene expression has a stronger correlation to (68)Ga-DOTATOC uptake than SSTR5. In addition, the results indicate that the gene expression levels of SSTR2 and SSTR5 at large follow one another
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