722 research outputs found
Large collective Lamb shift of two distant superconducting artificial atoms
Virtual photons can mediate interaction between atoms, resulting in an energy
shift known as a collective Lamb shift. Observing the collective Lamb shift is
challenging, since it can be obscured by radiative decay and direct atom-atom
interactions. Here, we place two superconducting qubits in a transmission line
terminated by a mirror, which suppresses decay. We measure a collective Lamb
shift reaching 0.8% of the qubit transition frequency and exceeding the
transition linewidth. We also show that the qubits can interact via the
transmission line even if one of them does not decay into it.Comment: 7+5 pages, 4+2 figure
Sex differences and survival in adults with bicuspid aortic valves : verification in 3 contemporary echocardiographic cohorts
Background-—Sex-related differences in morbidity and survival in bicuspid aortic valve (BAV) adults are fundamentally unknown.
Contemporary studies portend excellent survival for BAV patients identified at early echocardiographic-clinical stages. Whether
BAV adults incur a survival disadvantage throughout subsequent echocardiographic-clinical stages remains undetermined.
Methods and Results-—Analysis was done of 3 different cohorts of consecutive patients with echocardiographic diagnosis of BAV
identified retrospectively: (1) a community cohort of 416 patients with first BAV diagnosis (age 35 21 years, follow-up
16 7 years), (2) a tertiary clinical referral cohort of 2824 BAV adults (age 51 16 years, follow-up 9 6 years), and (3) a surgical
referral cohort of 2242 BAV adults referred for aortic valve replacement (AVR) (age 62 14 years, follow-up 6 5 years). For the
community cohort, 20-year risks of aortic regurgitation (AR), AVR, and infective endocarditis were higher in men (all P=0.04); for a
total BAV-related morbidity risk of 52 4% vs 35 6% in women (P=0.01). The cohort’s 25-year survival was identical to that in the
general population (P=0.98). AR independently predicted mortality in women (P=0.001). Baseline AR was more common in men
(P=0.02) in the tertiary cohort, with 20-year survival lower than that in the general population (P<0.0001); age-adjusted relative
death risk was 1.16 (95% confidence interval [CI] 1.05-1.29) for men versus 1.67 (95% CI 1.38-2.03) for women (P=0.001). AR
independently predicted mortality in women (P=0.01). Baseline AR and infective endocarditis were higher in men (both =0.001) for
the surgical referral cohort, with 15-year survival lower than that in the general population (P<0.0001); age-adjusted relative death
risk was 1.34 (95% CI 1.22-1.47) for men versus 1.63 (95% CI 1.40-1.89) for women (P=0.026). AR and NYHA class independently
predicted mortality in women (both P=0.04).
Conclusions-—Within evolving echocardiographic-clinical stages, the long-term survival of adults with BAV is not benign, as both
men and women incur excess mortality. Although BAV-related morbidity is higher in men in the community, and AR and infective
endocarditis are more prevalent in men, women exhibit a significantly higher relative risk of death in tertiary and surgical referral
cohorts, which is independently associated with A
The Gross--Llewellyn Smith Sum Rule in the Analytic Approach to Perturbative QCD
We apply analytic perturbation theory to the Gross--Llewellyn Smith sum rule.
We study the evolution and the renormalization scheme dependence of the
analytic three-loop QCD correction to this sum rule, and demonstrate that the
results are practically renormalization scheme independent and lead to rather
different evolution than the standard perturbative correction possesses.Comment: 17 pages, 9 eps figures, REVTe
The Complexity of Drawing a Graph in a Polygonal Region
We prove that the following problem is complete for the existential theory of
the reals: Given a planar graph and a polygonal region, with some vertices of
the graph assigned to points on the boundary of the region, place the remaining
vertices to create a planar straight-line drawing of the graph inside the
region. This strengthens an NP-hardness result by Patrignani on extending
partial planar graph drawings. Our result is one of the first showing that a
problem of drawing planar graphs with straight-line edges is hard for the
existential theory of the reals. The complexity of the problem is open in the
case of a simply connected region.
We also show that, even for integer input coordinates, it is possible that
drawing a graph in a polygonal region requires some vertices to be placed at
irrational coordinates. By contrast, the coordinates are known to be bounded in
the special case of a convex region, or for drawing a path in any polygonal
region.Comment: Appears in the Proceedings of the 26th International Symposium on
Graph Drawing and Network Visualization (GD 2018
A compendium and functional characterization of mammalian genes involved in adaptation to Arctic or Antarctic environments
Many mammals are well adapted to surviving in extremely cold environments. These species have likely accumulated genetic changes that help them efficiently cope with low temperatures. It is not known whether the same genes related to cold adaptation in one species would be under selection in another species. The aims of this study therefore were: to create a compendium of mammalian genes related to adaptations to a low temperature environment; to identify genes related to cold tolerance that have been subjected to independent positive selection in several species; to determine promising candidate genes/pathways/organs for further empirical research on cold adaptation in mammals
Individual variations in 'brain age' relate to early-life factors more than to longitudinal brain change
Another Avenue for Anatomy of Income Comparisons : Evidence from Hypothetical Choice Experiments
September 2010, Revised December 2010, Secondly Revised November 2011, Thirdly Revised May 2012, Fourthly Revised March 2013
Transplantation tolerance: lessons from experimental rodent models
Immunological tolerance or functional unresponsiveness to a transplant is arguably the only approach that is likely to provide long-term graft survival without the problems associated with life-long global immunosuppression. Over the past 50 years, rodent models have become an invaluable tool for elucidating the mechanisms of tolerance to alloantigens. Importantly, rodent models can be adapted to ensure that they reflect more accurately the immune status of human transplant recipients. More recently, the development of genetically modified mice has enabled specific insights into the cellular and molecular mechanisms that play a key role in both the induction and maintenance of tolerance to be obtained and more complex questions to be addressed. This review highlights strategies designed to induce alloantigen specific immunological unresponsiveness leading to transplantation tolerance that have been developed through the use of experimental models
Systemic therapy of Cushing’s syndrome
Cushing’s disease (CD) in a stricter sense derives from pathologic adrenocorticotropic hormone (ACTH) secretion usually triggered by micro- or macroadenoma of the pituitary gland. It is, thus, a form of secondary hypercortisolism. In contrast, Cushing’s syndrome (CS) describes the complexity of clinical consequences triggered by excessive cortisol blood levels over extended periods of time irrespective of their origin. CS is a rare disease according to the European orphan regulation affecting not more than 5/10,000 persons in Europe. CD most commonly affects adults aged 20–50 years with a marked female preponderance (1:5 ratio of male vs. female). Patient presentation and clinical symptoms substantially vary depending on duration and plasma levels of cortisol. In 80% of cases CS is ACTH-dependent and in 20% of cases it is ACTH-independent, respectively. Endogenous CS usually is a result of a pituitary tumor. Clinical manifestation of CS, apart from corticotropin-releasing hormone (CRH-), ACTH-, and cortisol-producing (malign and benign) tumors may also be by exogenous glucocorticoid intake. Diagnosis of hypercortisolism (irrespective of its origin) comprises the following: Complete blood count including serum electrolytes, blood sugar etc., urinary free cortisol (UFC) from 24 h-urine sampling and circadian profile of plasma cortisol, plasma ACTH, dehydroepiandrosterone, testosterone itself, and urine steroid profile, Low-Dose-Dexamethasone-Test, High-Dose-Dexamethasone-Test, after endocrine diagnostic tests: magnetic resonance imaging (MRI), ultra-sound, computer tomography (CT) and other localization diagnostics. First-line therapy is trans-sphenoidal surgery (TSS) of the pituitary adenoma (in case of ACTH-producing tumors). In patients not amenable for surgery radiotherapy remains an option. Pharmacological therapy applies when these two options are not amenable or refused. In cases when pharmacological therapy becomes necessary, Pasireotide should be used in first-line in CD. CS patients are at an overall 4-fold higher mortality rate than age- and gender-matched subjects in the general population. The following article describes the most prominent substances used for clinical management of CS and gives a systematic overview of safety profiles, pharmacokinetic (PK)-parameters, and regulatory framework
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