283 research outputs found
Discovery of a Classic FR-II Broad Absorption Line Quasar from the FIRST Survey
We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical
spectrum shows unambiguous broad absorption features while its double-lobed
radio morphology and luminosity clearly indicate a classic Fanaroff-Riley Type
II radio source. Its radio luminosity places it at the extreme of the recently
established class of radio-loud broad absorption line quasars (Becker et al.
1997, 2000; Brotherton et al. 1998). Because of its hybrid nature, we speculate
that FIRST J101614.3+520916 is a typical FR-II quasar which has been
rejuvenated as a broad absorption line (BAL) quasar with a Compact Steep
Spectrum core. The direction of the jet axis of FIRST J101614.3+520916 can be
estimated from its radio structure and optical brightness, indicating that we
are viewing the system at a viewing angle of > 40 degrees. The position angles
of the radio jet and optical polarization are not well-aligned, differing by 20
to 30 degrees. When combined with the evidence presented by Becker et al.
(2000) for a sample of 29 BAL quasars showing that at least some BAL quasars
are viewed along the jet axis, the implication is that no preferred viewing
orientation is necessary to observe BAL systems in a quasar's spectrum. This,
and the probable young nature of compact steep spectrum sources, leads
naturally to the alternate hypothesis that BALs are an early stage in the lives
of quasars.Comment: 14 pages, 6 postscript figures; accepted for publication in the
Astrophysical Journa
Etwas mehr Anpassung gewĂŒnscht: Einstellungen zur Integration von AuslĂ€ndern in Deutschland
"Die Integration von AuslĂ€ndern ist ein Thema, das seit langem Aufmerksamkeit in der öffentlichen Diskussion findet. Anlass fĂŒr eine solche Debatte sind offensichtlich Schwierigkeiten, die immer wieder im IntegrationsprozeĂ auftreten. So hat das schlechte Abschneiden von SchĂŒlern mit Migrationshintergrund in den PISA-Studien die Problematik mangelnder Integration wiederholt deutlich gemacht. Auch ist man sich zunehmend der Tatsache bewusst geworden, dass sich viele AuslĂ€nder in subkulturelle Gemeinschaften zurĂŒckgezogen haben. Vor diesem Hintergrund werden immer wieder Initiativen gestartet, die den AuslĂ€ndern die Integration in die deutsche Gesellschaft erleichtern sollen. Dabei hat es sich allerdings als Problem erwiesen, dass man sich in Deutschland lange gescheut hat, auch den AuslĂ€ndern eine gewisse Integrationsleistung abzuverlangen. Die ALLBUS-Umfrage von 2006 bietet die Möglichkeit zu untersuchen, ob sich die Einstellungen der Deutschen zur Integration der AuslĂ€nder diesbezĂŒglich verĂ€ndert haben." (Autorenreferat
Indole-3-Carbinol Inhibits the Growth of Endometriotic Lesions by Suppression of Microvascular Network Formation
Endometriosis represents an estrogenâdependent disorder with a complex pathophysiolâ
ogy. Phytochemicals are promising candidates for endometriosis therapy, because they simultaâ
neously target different cellular processes involved in the pathogenesis of endometriosis. Herein,
we analyzed whether indoleâ3âcarbinol (I3C) suppresses the development of endometriotic lesions,
which were surgically induced by fixation of uterine tissue samples (diameter: 2 mm) from female
BALB/c donor mice to the peritoneum of recipient animals. The mice received either I3C or veâ
hicle (control) by peroral administration once per day. Growth, cyst formation, cell proliferation,
microvascularization and protein expression of the lesions were assessed by highâresolution ultraâ
sound imaging, caliper measurements, histology, immunohistochemistry and Western blotting. I3C
inhibited the vascularization and growth of endometriotic lesions without inducing antiâangiogenic
and antiâproliferative side effects on reproductive organs. This was associated with a significantly
reduced number of proliferating stromal and endothelial cells and a lower expression of the proâ
angiogenic signaling molecules vascular endothelial growth factor receptorâ2 (VEGFR2), phosphoâ
inositide 3âkinase (PI3K) and phosphorylated extracellular signalâregulated kinase (pERK) within
I3Câtreated lesions when compared to controls. These findings indicate that I3C effectively inhibits
endometriotic lesion formation in mice. Thus, further studies should clarify whether I3C may be
also beneficial for the prevention and therapy of the human disease
The Implications of Globalization for Firms` Demand for Skilled and Unskilled Labor.
This paper investigates the impact of globalization, in the sense of increasing international trade, on the demand for skills in Danish manufacturing companies. The study is based on a unique data set that enables us to develop rich measures of international outsourcing and import penetration. Moreover, the data also allows several strategies to strengthen the causal interpretation of our results. The main finding of the analysis is that it is of crucial importance to distinguish imports - both in the form of outsourcing and overall imports - by country-of-origin. We find that international trade with low-wage countries leads to skill-upgrading. This is especially pronounced for import penetration with a ceteris paribus contribution of around fifty percent to skill-upgrading. Moreover, we find that import penetration in goods originating from high-wage countries lead to skill-downgrading. This latter result suggests that Danish manufacturing has comparative advantage in skill intensive production when compared to low-wage countries, but in unskill-intensive production when compared to high-wage countries. Skill-upgrading, Low-wage country outsourcing, Low-wage country import penetration, Comparative advantag
Was hat die Reform der Minijobs bewirkt?
Viel wird ĂŒber die "Hartz-Reformen" und ihre Effekte spekuliert, aber es gibt bislang so gut wie keine aussagekrĂ€ftigen Belege, auf die sich derartige Schlussfolgerungen stĂŒtzen können. Auch wenn sich viele Wirkungen erst im Zeitablauf richtig entfalten werden, besteht doch die Möglichkeit zu einer ersten Zwischenbilanz fĂŒr Komponenten, die bereits umgesetzt sind. Eine solche ist die Neuregelung bei Minijobs, die zum 1. April 2003 in Kraft trat. Die Untersuchung beinhaltet damit die erste fundierte Analyse fĂŒr diesen Bereich. Sie knĂŒpft an das umfassende Evaluierungskonzept an, das als Heft 74 der "RWI : Schriften" veröffentlicht worden war. Untersucht werden insbesondere die Quellen des Zuflusses in Minijobs nach der Reform sowie der Handlungsbedarf, der dadurch entsteht, dass Arbeitslose nicht im erwarteten Umfang derartige BeschĂ€ftigungsverhĂ€ltnisse aufnehmen bzw. aus ihnen heraus in eine sozialversicherungspflichtige BeschĂ€ftigung wechseln. Die Ergebnisse liefern ein gemischtes Bild: So wurde das Ziel, die AttraktivitĂ€t geringfĂŒgiger BeschĂ€ftigungsverhĂ€ltnisse zu steigern, zwar erreicht, jedoch sind erhebliche Zweifel angebracht, ob Minijobs fĂŒr Arbeitslose tatsĂ€chlich als BrĂŒcke in nicht-geringfĂŒgige BeschĂ€ftigung dienen können. Um diese Funktion zu stĂ€rken, wird der "Erweiterte Minijob fĂŒr Arbeitslose" vorgestellt, der in bestimmten FĂ€llen eine zeitlich befristete Erhöhung der Einkommensgrenze vorsieht, wobei gleichzeitig die Hinzuverdienstmöglichkeiten generöser gestaltet werden. Zur Abrundung werden die Arbeitsmarktwirkungen sowie die "Kosten" des Reformvorschlags abgeschĂ€tzt
The ischemic time window of ectopic endometrial tissue crucially determines its ability to develop into endometriotic lesions
Endometriosis develop from shed endometrial fragments via retrograde menstruation. This afects
the survival, proliferation and vascularization of the tissue and its fnal ability to form endometriotic
lesions. Within this study, uterine tissue samples from donor mice were precultivated for 24 h or
72 h to simulate avascular periods. Their morphology, microvessel density, apoptotic activity and
expression of angiogenesis-related proteins were analyzed in vitro. The formation of endometriotic
lesions in vivo was assessed after transplantation of precultivated uterine tissue samples to the
abdominal wall and dorsal skinfold chambers by means of high-resolution ultrasound, intravital
fuorescence microscopy, histology and immunohistochemistry. In vitro, 72-h-precultivated
uterine tissue samples exhibit extensive areas of tissue necrosis and high numbers of apoptotic
cells as well as a signifcantly reduced cell and microvessel density. These samples failed to develop
into endometriotic lesions. In contrast, the 24-h-precultivated samples showed, that their early
vascularization and growth in vivo was improved when compared to controls. This indicates that
avascular periods have a strong impact on the survival of ectopic endometrial tissue and the chance for
the development of endometriosis
Insulin-like growth factor 1 stimulates the angiogenic activity of adipose tissue-derived microvascular fragments
Angiogenesis in adipose tissue is promoted by insulin-like growth factor 1 signaling. We analyzed whether this regulatory mechanism also improves the angiogenic activity of adipose tissue-derived microvascular fragments. Murine adipose tissue-derived microvascular fragments were cultivated for 24âh in the University of Wisconsin (UW) solution supplemented with vehicle, insulin-like growth factor 1, or a combination of insulin-like growth factor 1 and insulin-like growth factor-binding protein 4. Subsequently, we assessed their cellular composition, viability, proliferation, and growth factor expression. Moreover, cultivated adipose tissue-derived microvascular fragments were seeded onto collagen-glycosaminoglycan scaffolds, which were implanted into dorsal skinfold chambers to study their vascularization and incorporation. Insulin-like growth factor 1 increased the viability and growth factor expression of adipose tissue-derived microvascular fragments without affecting their cellular composition and proliferation. Accordingly, scaffolds containing insulin-like growth factor 1-stimulated adipose tissue-derived microvascular fragments exhibited an enhanced in vivo vascularization and incorporation. These positive insulin-like growth factor 1 effects were reversed by additional exposure of adipose tissue-derived microvascular fragments to insulin-like growth factor-binding protein 4. Our findings indicate that insulin-like growth factor 1 stimulation of adipose tissue-derived microvascular fragments is suitable to improve their vascularization capacity
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