52 research outputs found
Determination of masses of the central black holes in NGC524 and NGC2549 using Laser Guide Star Adaptive Optics
[abridged] We present observations of NGC524 and NGC2549 with LGS AO obtained
at GEMINI North telescope using the NIFS IFU in the K band. The purpose of
these observations, together with previously obtained observations with the
SAURON IFU, is to determine the masses (Mbh) of the supermassive black holes
(SMBH). The targeted galaxies were chosen to have central light profiles
showing a core (NGC524) and a cusp (NGC2549), to probe the feasibility of using
the galaxy centre as the NGS required for LGS AO. We employ an innovative `open
loop' technique. The data have spatial resolution of 0.23" and 0.17" FWHM,
showing that high quality LGS AO observations of these objects are possible. We
construct axisymmetric three-integral dynamical models which are constrained
with both the NIFS and SAURON data. The best fitting models yield Mbh=(8.3 +2.7
-1.3) x 10^8 Msun for NGC524 and Mbh=(1.4 +0.2 -1.3) x 10^7 Msun for NGC2549
(all errors are at the 3 sigma CL). We demonstrate that the wide-field SAURON
data play a crucial role in the M/L determination increasing the accuracy of
M/L by a factor of at least 5, and constraining the upper limits on Mbh. The
NIFS data are crucial in constraining the lower limits of Mbh and in
combination with the large scale data reducing the uncertainty by a factor of 2
or more. We find that the orbital structure of NGC524 shows significant
tangential anisotropy, while at larger radii both galaxies are consistent with
having almost perfectly oblate velocity ellipsoids. Tangential anisotropy in
NGC524 coincides with the size of SMBH sphere of influence and the core region
in the light profile. We test the accuracy to which Mbh can be measured using
seeings obtained from typical LGS AO observations, and conclude that for a
typical conditions and Mbh the expected uncertainty is of the order of 50%.Comment: 19 pages, 14 figure
The Economic Crisis and Residential Electricity Consumption in Spanish Provinces: A Spatial Econometric Analysis
This paper presents an empirical analysis of residential electricity demand considering the existence of spatial effects. This analysis has been performed using aggregate panel data at the province level for 46 Spanish provinces for the period from 2001 to 2009. For this purpose, we estimated a log-log demand equation using a spatial autoregressive model with autoregressive disturbances (SARAR). The purpose of this empirical analysis is to determine the influence of price, income, and spatial spillovers on residential electricity demand in Spain. We are particularly interested in analyzing the impact of household disposable income variation across provinces observed during the economic crisis period from 2008-2009. The estimation results show relatively high income elasticity and relatively low price elasticity. Furthermore, the results show the presence of spatial effects in Spanish residential electricity consumption
Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial
Background:
Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment.
Methods:
This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal.
Results:
Enrolment began in 2016, and the study is expected to end in 2020.
Conclusions:
This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission.
Clinical trial reference number:
EudraCT 2015-001410-1
Overeducation Among Graduates: An Overlooked Facet of the Gender Pay Gap? Evidence from East and West Germany
Germany's occupational and sectoral change towards a knowledge-based economy calls for high returns to education. Nevertheless, female graduates are paid much less than their male counterparts. We wonder whether overeducation affects sexes differently and whether this might answer for part of the gender pay gap. We decompose total year of schooling in years of over- (O), required (R), and undereducation (U). As ORU earnings estimations based on German SOEP cross-section and panel data indicate, overeducation pays off less than required education in the current job even when unobserved heterogeneity is taken into account. Moreover, analyses of job satisfaction and self-assessed overeducation point to some real mismatch. However, overeducation does not matter for the gender pay gap. By contrast, women's fewer years of required education reasonably do, answering for 7.61 pp. of the East German (18.79 %) and 2.22 pp. of the West German (32.98 %) approximate gap. Moreover, job biography and the household context affect the gap more seriously in the old Bundesländer than in the new ones. Overall, the West German pay gap almost doubles the East German one, and different endowments answer for roughly three quarters of the approximate gap in the Western but only for two thirds in the Eastern part. We conclude that the gendered earnings gap among German graduates is rather shaped by an employment behaviour suiting traditional gender roles and assigned gender stereotypes than being subject to gendered educational inadequacy
A Search for Photons with Energies Above 2X10(17) eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory
Ultra-high-energy photons with energies exceeding 10(17) eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 10(15) eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 x 10(17) eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 10(17) and 10(18) eV
Who is Overeducated and Why? Probit and Dynamic Mixed Multinomial Logit Analyses of Vertical Mismatch in East and West Germany
Overeducation is an often overlooked facet of untapped human resources. But who is overeducated and why? Relying on SOEP data 1984-2011, we use probit models for estimating the likelihood of entering overeducation and dynamic mixed multinomial logit models with random effects addressing state dependence and unobserved heterogeneity. As further robustness checks we use three specifications of the target variable, i.e. realized matches, self-assessment and twofold overeducation. We run separate analyses for men and women, East and West Germans and medium and highly educated persons. We find that overeducation is mainly state dependent. Nonetheless, even in the dynamic context staying employed proves to be risk-decreasing. By contrast, scars of past unemployment show up in a higher mismatch risk. Moreover, an employer change does not serve as a suitable exit strategy, and a dual qualification does not show up as a valid insurance against graduates' job mismatch. Overall, effects largely depend on the operationalization of overeducation. We conclude that to combat overeducation, focusing on continuous employment careers and circumventing unintentional withdrawals from the current job is crucial. Moreover, institutional impediments that restrain job match quality for certain groups (migrants, mothers) have to be tackled.Überqualifikation ist ein zuweilen übersehener Aspekt in der Debatte um ungenutzte Fachkräftepotenziale. Aber wer ist überqualifiziert, und warum? Basierend auf Daten des Sozio-oekonomischen Panels (SOEP) der Wellen 1984-2011 schätzen wir mit Probitmodellen die Wahrscheinlichkeit für neue Überqualifikation sowie mit dynamischen Multinomialen Mixed Logit-Modellen mit zufälligen Effekten die Wahrscheinlichkeit für Überqualifikation unter Berücksichtigung von Pfadabhängigkeit und unbeobachteter Populationsheterogenität. Das Messfehlerproblem kontrollieren wir durch drei verschiedene Spezifikationen der abhängigen Variable, die selbsteingeschätzte Überqualifikation, die statistische Überqualifikation (Realized Matches) sowie eine Kombination aus beidem. Wir führen die Schätzungen getrennt für Männer und Frauen, Ost- und Westdeutsche sowie Personen mittlerer und hoher Bildung durch. Unsere Analysen zeigen, dass Überqualifikation ein hohes Beharrungsvermögen hat. Allerdings vermindert Erwerbserfahrung das Risiko der Überqualifikation auch im dynamischen Modell unter Kontrolle unbeobachteter Heterogenität. Narbeneffekte früherer Arbeitslosigkeit hingegen zeigen sich in einem höheren Überqualifikationsrisiko. Weder ein Arbeitgeberwechsel noch (bei Akademiker/innen) eine Doppelqualifikation in Form von Lehre plus Studium taugen als wirksame Ausweichstrategien. Um Überqualifikation im Job zu vermindern, scheinen Strategien, die konti-nuierliche Erwerbskarrieren fördern, vielversprechend zu sein. Für bestimmte Gruppen am Arbeitsmarkt (Migranten, Mütter) erschweren zudem institutionelle Barrieren ein gutes Jobmatch, die es gezielt anzugehen gilt
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