8,668 research outputs found
Age and metallicity gradients in fossil ellipticals
Fossil galaxy groups are speculated to be old and highly evolved systems of
galaxies that formed early in the universe and had enough time to deplete their
galaxies through successive mergers of member galaxies, building up one
massive central elliptical, but retaining the group X-ray halo. Considering
that fossils are the remnants of mergers in ordinary groups, the merger history
of the progenitor group is expected to be imprinted in the fossil central
galaxy (FCG). We present for the first time radial gradients of single-stellar
population (SSP) ages and metallicites in a sample of FCGs to constrain their
formation scenario. Our sample comprises some of the most massive galaxies in
the universe exhibiting an average central velocity dispersion of
km s. Metallicity gradients are throughout negative
with comparatively flat slopes of while
age gradients are found to be insignificant ().
All FCGs lie on the fundamental plane, suggesting that they are virialised
systems. We find that gradient strengths and central metallicities are similar
to those found in cluster ellipticals of similar mass. The comparatively flat
metallicity gradients with respect to those predicted by monolithic collapse
() suggest that fossils are indeed the result of multiple
major mergers. Hence we conclude that fossils are not 'failed groups' that
formed with a top heavy luminosity function. The low scatter of gradient slopes
suggests a similar merging history for all galaxies in our sample.Comment: 14 pages, 12 Figures, accepted for publication in A&
Reforming German Labor Market Institutions: A Dual Path to Flexibility
Germany has always been one of the prime examples of institutional complementarities between social insurance, a rather passive welfare state, strong employment protection and collective bargaining that stabilize diversified quality production. This institutional arrangement was criticized for being the main cause of inferior labor market performance and increasing fiscal pressure on the welfare state while at the same time inhibiting institutional change. However, over the last 15 years, a sequence of institutional reforms has fundamentally modified the functioning of the German labor market and increased both flexibility and job creation capacities through two intimately linked processes that redefined the line between inactivity, the flexible and the standard segment of the labor market. On the one hand, policy changes facilitated the expansion of flexible or 'atypical' jobs, whereas increasing flexibility of the standard employment relationship resulted from wage moderation and working time flexibility. While at the outset of this reform sequence German had a small, but relatively egalitarian labor market, the number of jobs, but also their diversity has increased.Germany, labor market reforms, atypical employment, standard employment relationship
Heisenberg uncertainty for qubit measurements
Reports on experiments recently performed in Vienna [Erhard et al, Nature
Phys. 8, 185 (2012)] and Toronto [Rozema et al, Phys. Rev. Lett. 109, 100404
(2012)] include claims of a violation of Heisenberg's error-disturbance
relation. In contrast, we have presented and proven a Heisenberg-type relation
for joint measurements of position and momentum [Phys. Rev. Lett. 111, 160405
(2013)]. To resolve the apparent conflict, we formulate here a new general
trade-off relation for errors in qubit measurements, using the same concepts as
we did in the position-momentum case. We show that the combined errors in an
approximate joint measurement of a pair of +/-1 valued observables A,B are
tightly bounded from below by a quantity that measures the degree of
incompatibility of A and B. The claim of a violation of Heisenberg is shown to
fail as it is based on unsuitable measures of error and disturbance. Finally we
show how the experiments mentioned may directly be used to test our error
inequality.Comment: Version 3 contains further clarifications in our argument refuting
the alleged violation of Heisenberg's error-disturbance relation. Some new
material added on the connection between preparation uncertainty and
approximation error relation
The Use of Flexible Measures to Cope with Economic Crises in Germany and Brazil
This study gives a comparative overview of labor market dynamics and institutional arrangements in Germany and Brazil with particular emphasis on industrial relations, wage setting, unemployment benefits, employment protection and vocational training. The paper shows that institutions determine the mode of adjustment to changing economic conditions and the role of standard vs. non-standard contracts. Whereas internal flexibility via shorter working time was a dominant mode of adjustment during the 2008-09 crisis in the German manufacturing sector, in Brazil such plant-level flexibility to avoid dismissals was less prominent.dismissal protection, working time, labor market flexibility, Germany, Brazil
SGLT-2 Inhibitors: A Novel Mechanism in Targeting Glycemic Control in Type 2 Diabetes Mellitus
OBJECTIVE: To review the chemistry, pharmacology, pharmacodynamics, pharmacokinetics, clinical efficacy, tolerability, dosing, drug interactions, and administration of canagliflozin, dapagliflozin, and empagliflozin, and comparing the benefit and risk aspects of using these agents in the older adult diabetes patient population.
DATA SOURCES, STUDY SELECTION, DATA EXTRACTION, AND DATA SYNTHESIS: A search of PubMed using the terms SGLT-2 inhibitors, canagliflozin, dapagliflozin, empagliflozin, efficacy, and tolerability was performed to find relevant primary literature on each of the sodium/glucose cotransporter 2 (SGLT-2) inhibitors currently approved for use in type 2 diabetes. Phase III trials for all agents were included. All English-language articles from 2010 to 2015 appearing in these searches were reviewed for relevance to this paper. In addition, related articles suggested in the PubMed search were also reviewed. The SGLT-2 inhibitors have shown a reduction in hemoglobin A1c values and fasting plasma glucose levels with a low incidence of hypoglycemia. The incidence of mycotic infections is increased in patients taking an SGLT-2 inhibitor.
CONCLUSION: SGLT-2 inhibitors may be a viable treatment option for patients not controlled on other oral agents. The risk of hypoglycemia is small. However, the clinical efficacy and tolerability of these agents has not been fully elucidated in older and frail patients
Measuring position and moment together
We describe an operational scheme for determining both the position and
momentum distributions in a large class of quantum states, together with an
experimental implementation.Comment: 4 pages, no figures, to be published in Phys. Lett.
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