1,121 research outputs found
Does a large quantum Fisher information imply Bell correlations?
The quantum Fisher information (QFI) of certain multipartite entangled
quantum states is larger than what is reachable by separable states, providing
a metrological advantage. Are these nonclassical correlations strong enough to
potentially violate a Bell inequality? Here, we present evidence from two
examples. First, we discuss a Bell inequality designed for spin-squeezed states
which is violated only by quantum states with a large QFI. Second, we relax a
well-known lower bound on the QFI to find the Mermin Bell inequality as a
special case. However, a fully general link between QFI and Bell correlations
is still open.Comment: 4 pages, minor edit
The posterolateral fluoroscopy-guided injection technique into the posterior subtalar joint: description of the procedure and pilot study on patient outcomes
Objective: To describe a posterolateral fluoroscopy-guided injection technique into the posterior subtalar joint and to report patient outcomes 1month post-injection. Materials and methods: Twenty-three consecutive adult patients who underwent fluoroscopy-guided injection into the posterior subtalar joint using a direct posterolateral approach and who returned an outcomes-based postal questionnaire after receiving this injection were included. Numerical pain rating scale (NRS) data were collected prior to injection. NRS and Patient's Global Impression of Change (PGIC) scales were completed 1day, 1week, and 1month after injection. The proportion of patients who improved was calculated for each time period. Baseline NRS data were compared to each time point using the Wilcoxon test to assess differences. Spearman's correlation coefficient was used to compare the 20min NRS score with all follow-up NRS scores. All available images were reviewed for the presence of subtalar osteoarthritis (OA). Patient charts were reviewed to identify characteristics of patients referred for subtalar injections. Risk ratios were calculated comparing presence of OA or other abnormalities with improvement. Results: A posterolateral approach for fluoroscopy-guided injections into the subtalar joint is described. There was a significant reduction in the mean NRS score at all time periods compared to baseline (p ≤ 0.004). One-third of patients (7/21) reported clinically relevant improvement at 1month. Conclusions: Fluoroscopy-guided puncture of the posterior subtalar joint using a posterolateral approach is possible. Clinically significant improvement is reported in 33% of patients after 1mont
Tight steering inequalities from generalized entropic uncertainty relations
We establish a general connection between entropic uncertainty relations,
Einstein-Podolsky-Rosen steering, and joint measurability. Specifically, we
construct steering inequalities from any entropic uncertainty relation, given
that the latter satisfies two natural properties. We obtain steering
inequalities based on R\'enyi entropies. These turn out to be tight in many
scenarios, using max- and min-entropy. Considering steering tests with two
noisy measurements, our inequalities exactly recover the noise threshold for
steerability. This is the case for any pair of qubit 2-outcome measurements, as
well as for pairs of mutually unbiased bases in any dimension. This shows that
easy-to-evaluate quantities such as entropy can optimally witness steering,
despite the fact that they are coarse-grained representations of the underlying
statistics
Quantifying photonic high-dimensional entanglement
High-dimensional entanglement offers promising perspectives in quantum
information science. In practice, however, the main challenge is to devise
efficient methods to characterize high-dimensional entanglement, based on the
available experimental data which is usually rather limited. Here we report the
characterization and certification of high-dimensional entanglement in photon
pairs, encoded in temporal modes. Building upon recently developed theoretical
methods, we certify an entanglement of formation of 2.09(7) ebits in a time-bin
implementation, and 4.1(1) ebits in an energy-time implementation. These
results are based on very limited sets of local measurements, which illustrates
the practical relevance of these methods.Comment: 5 pages, 3 figure
Ankylosing spondylitis and heart abnormalities: do cardiac conduction disorders, valve regurgitation and diastolic dysfunction occur more often in male patients with diagnosed ankylosing spondylitis for over 15years than in the normal population?
The objective of this study was to determine the rate of selected cardiac pathologies (conduction disorders, valve regurgitation and diastolic dysfunction) in patients with long-standing ankylosing spondylitis (AS) and compare the results with the prevalence in the normal population. A rheumatologic (structured questionnaire interview) and cardiac evaluation (resting electrocardiography and echocardiography) was performed in 100 male subjects with AS and a disease duration of more than 15years. The rates for conduction disorders, aortic and mitral valve regurgitation and diastolic dysfunction were compared with the corresponding results in the literature among the normal population. In patients with long-standing AS there was no increased rate for valve regurgitation (mitral and aortic valve) and for arrhythmia. Diastolic dysfunction occurred more often in patients with long-standing AS. However, this might be caused by the presence of other cardiovascular risk factors such as age and hypertension. According to these results, a cardiologic evaluation with echocardiography should not be recommended routinely in patients with long-standing AS. To confirm these results, a large prospective study with patients with long-standing AS and with a matched control group should be performed in the futur
Unlimited One-Way Steering
This work explores the asymmetry of quantum steering in a setup using
high-dimensional entanglement. We construct entangled states with the following
properties: one party (Alice) can never steer the state of the other
party (Bob), considering the most general measurements, and Bob can
strongly steer the state of Alice, demonstrating genuine high-dimensional
steering. In other words, Bob can convince Alice that they share an entangled
state of arbitrarily high Schmidt number, while Alice can never convince Bob
that the state is even simply entangled. In this sense, one-way steering can
become unlimited. A key result for our construction is a condition for the
joint measurability of all high-dimensional measurements subjected to the
combined effect of noise and loss, which is of independent interest.Comment: 4+4 page
Experimental certification of millions of genuinely entangled atoms in a solid
Quantum theory predicts that entanglement can also persist in macroscopic
physical systems, albeit difficulties to demonstrate it experimentally remain.
Recently, significant progress has been achieved and genuine entanglement
between up to 2900 atoms was reported. Here we demonstrate 16 million genuinely
entangled atoms in a solid-state quantum memory prepared by the heralded
absorption of a single photon. We develop an entanglement witness for
quantifying the number of genuinely entangled particles based on the collective
effect of directed emission combined with the nonclassical nature of the
emitted light. The method is applicable to a wide range of physical systems and
is effective even in situations with significant losses. Our results clarify
the role of multipartite entanglement in ensemble-based quantum memories as a
necessary prerequisite to achieve a high single-photon process fidelity crucial
for future quantum networks. On a more fundamental level, our results reveal
the robustness of certain classes of multipartite entangled states, contrary
to, e.g., Schr\"odinger-cat states, and that the depth of entanglement can be
experimentally certified at unprecedented scales.Comment: 11 pages incl. Methods and Suppl. Info., 4 figures, 1 table. v2:
close to published version. See also parallel submission by Zarkeshian et al
(1703.04709
Subtypes of complex regional pain syndrome-a systematic review of the literature
To systematically identify and summarize possible subtypes of complex regional pain syndrome (CRPS), we searched MEDLINE, Embase, Cochrane, Scopus, and Web of Science for original studies reporting or investigating at least one subtype within a group of patients with CRPS. The search retrieved 4239 potentially relevant references. Twenty-five studies met our inclusion criteria and were included in the analysis. Complex regional pain syndrome phenotypes were investigated based on the following variables: clinical presentation/sensory disturbances, dystonia, skin temperature, disease duration, onset type, CRPS outcome, and neuropsychological test performance. Support was found for the following CRPS subtypes: CRPS type I, CRPS type II, acute CRPS, chronic CRPS, centralized CRPS, cold CRPS, warm CRPS, inflammatory CRPS, dystonic CRPS, nondystonic CRPS, familial CRPS, and nonfamilial CRPS. It is unclear whether these are distinct or overlapping subtypes. The results of this comprehensive review can facilitate the formulation of well-defined CRPS subtypes based on presumed underlying mechanisms. Our findings provide a foundation for establishing and defining clinically meaningful CRPS subtypes, with the ultimate goal of developing targeted and enhanced treatments for CRPS
Johannes Heinrich Schultz (1884-1970) - BegrĂĽnder des Autogenen Trainings: ein biographischer Rekonstruktionsversuch im Spannungsfeld von Wissenschaft und Politik
The role of the bone in complex regional pain syndrome 1-A systematic review
OBJECTIVE: The aim of this systematic review was to appraise and analyse the knowledge on bone-related biochemical and histological biomarkers in complex regional pain syndrome 1 (CRPS 1).
DATABASE: A total of 7 studies were included in the analysis (biochemical analyses n  = 3, animal study n  = 1, histological examination n  = 3).
RESULTS: Two studies were classified as having a low risk of bias and five studies with a moderate risk of bias. Biochemical analysis indicated an increased bone turnover with increased bone resorption (elevated urinary levels of deoxypyridinoline) and bone formation (increased serum levels of calcitonin, osteoprotegerin and alkaline phosphatase). The animal study reported an increased signalling of proinflammatory tumour necrosis factor 4 weeks postfracture, which did, however, not contribute to local bone loss. Histological examination from biopsies revealed thinning and resorption of cortical bone, rarefication and reduction in trabecular bone and vascular modification in the bone marrow in acute CRPS 1, and replacement of the bone marrow by dystrophic vessels in chronic CRPS 1.
CONCLUSION: The limited data reviewed revealed certain potential bone-related biomarkers in CRPS. Biomarkers hold the potential to identify patients who may benefit from treatments that influence bone turnover. Thus, this review identifies important areas for future research in CRPS1 patients
- …