Efficient Teleportation between Remote Single-Atom Quantum Memories

We demonstrate teleportation of quantum bits between two single atoms in distant laboratories. Using a time-resolved photonic Bell-state measurement, we achieve a teleportation fidelity of (88.0+/-1.5)%, largely determined by our entanglement fidelity. The low photon collection efficiency in free space is overcome by trapping each atom in an optical cavity. The resulting success probability of 0.1% is almost 5 orders of magnitude larger than in previous experiments with remote material qubits. It is mainly limited by photon propagation and detection losses and can be enhanced with a cavity-based deterministic Bell-state measurement.Comment: 7 pages, 4 figures, 1 tabl

Generation of single photons from an atom-cavity system

A single rubidium atom trapped within a high-finesse optical cavity is an efficient source of single photons. We theoretically and experimentally study single-photon generation using a vacuum stimulated Raman adiabatic passage. We experimentally achieve photon generation efficiencies of up to 34% and 56% on the D1 and D2 line, respectively. Output coupling with 89% results in record-high efficiencies for single photons in one spatiotemporally well-defined propagating mode. We demonstrate that the observed generation efficiencies are constant in a wide range of applied pump laser powers and virtual level detunings. This allows for independent control over the frequency and wave packet envelope of the photons without loss in efficiency. In combination with the long trapping time of the atom in the cavity, our system constitutes a significant advancement toward an on-demand, highly efficient single-photon source for quantum information processing tasks.Comment: 7 pages, 5 figure

Risk Assessment Using Two Different Diagnostic Tools: Metabolic Syndrome and Cardiovascular Risk Score (SCORE) - Data from a Weight Reduction Intervention Study

Objective: Risk score models and the diagnosis of a metabolic syndrome are useful for cardiovascular (CV) risk prediction. The identification of individuals with high CV and metabolic risk is essential to provide appropriate prevention and therapy. The present study aims at clarifying whether these indicators are altered by a weight reduction programme. Additionally, which diagnostic tool has a better predictive value is examined. Method: One hundred and twenty overweight and obese subjects aged 30 60 years were included in a 12-week weight reduction programme. The CV risk was assessed by means of German multiple-used risk charts (SCORE) at baseline and at the end of the trial. Furthermore, the prevalence of the metabolic syndrome (three out of five risk factors) was quantified. Results: The initial prevalence of the metabolic syndrome was 63.3% (n = 76) and decreased to 41.7% (n = 50) by the end of the intervention. The SCORE also decreased significantly after twelve weeks (p 5%) was comparatively low (t0: 7.4%, n = 7; t12: 5.3%, n = 5). Conclusion: The weight reduction concept was applicable to improve the CV risk SCORE and decrease the prevalence of the metabolic syndrome. The CV 10-year risk calculated using German risk charts (SCORE) probably underestimated the risk of CV diseases in this collective. In this case, the diagnosis of a metabolic syndrome is more meaningful than risk SCORE calculations

Local synchronization of resting-state dynamics encodes Gray's trait Anxiety

The Behavioral Inhibition System (BIS) as defined within the Reinforcement Sensitivity Theory (RST) modulates reactions to stimuli indicating aversive events. Gray’s trait Anxiety determines the extent to which stimuli activate the BIS. While studies have identified the amygdala-septo-hippocampal circuit as the key-neural substrate of this system in recent years and measures of resting-state dynamics such as randomness and local synchronization of spontaneous BOLD fluctuations have recently been linked to personality traits, the relation between resting-state dynamics and the BIS remains unexplored. In the present study, we thus examined the local synchronization of spontaneous fMRI BOLD fluctuations as measured by Regional Homogeneity (ReHo) in the hippocampus and the amygdala in twenty-seven healthy subjects. Correlation analyses showed that Gray’s trait Anxiety was significantly associated with mean ReHo in both the amygdala and the hippocampus. Specifically, Gray’s trait Anxiety explained 23% and 17% of resting-state ReHo variance in the left amygdala and the left hippocampus, respectively. In summary, we found individual differences in Gray’s trait Anxiety to be associated with ReHo in areas previously associated with BIS functioning. Specifically, higher ReHo in resting-state neural dynamics corresponded to lower sensitivity to punishment scores both in the amygdala and the hippocampus. These findings corroborate and extend recent findings relating resting-state dynamics and personality while providing first evidence linking properties of resting-state fluctuations to Gray’s BIS

Likelihood Non-Gaussianity in Large-Scale Structure Analyses

Standard present day large-scale structure (LSS) analyses make a major assumption in their Bayesian parameter inference --- that the likelihood has a Gaussian form. For summary statistics currently used in LSS, this assumption, even if the underlying density field is Gaussian, cannot be correct in detail. We investigate the impact of this assumption on two recent LSS analyses: the Beutler et al. (2017) power spectrum multipole ($P_\ell$) analysis and the Sinha et al. (2017) group multiplicity function ($\zeta$) analysis. Using non-parametric divergence estimators on mock catalogs originally constructed for covariance matrix estimation, we identify significant non-Gaussianity in both the $P_\ell$ and $\zeta$ likelihoods. We then use Gaussian mixture density estimation and Independent Component Analysis on the same mocks to construct likelihood estimates that approximate the true likelihood better than the Gaussian $pseudo$-likelihood. Using these likelihood estimates, we accurately estimate the true posterior probability distribution of the Beutler et al. (2017) and Sinha et al. (2017) parameters. Likelihood non-Gaussianity shifts the $f\sigma_8$ constraint by $-0.44\sigma$, but otherwise, does not significantly impact the overall parameter constraints of Beutler et al. (2017). For the $\zeta$ analysis, using the pseudo-likelihood significantly underestimates the uncertainties and biases the constraints of Sinha et al. (2017) halo occupation parameters. For $\log M_1$ and $\alpha$, the posteriors are shifted by $+0.43\sigma$ and $-0.51\sigma$ and broadened by $42\%$ and $66\%$, respectively. The divergence and likelihood estimation methods we present provide a straightforward framework for quantifying the impact of likelihood non-Gaussianity and deriving more accurate parameter constraints.Comment: 33 pages, 7 figure

Breastfeeding woman are at higher risk of vitamin D deficiency than non-breastfeeding women - insights from the German VitaMinFemin study

Background: Despite increased awareness of the adverse health effects of vitamin D deficiency, only a few studies have evaluated the vitamin D status (25-hydroxyvitamin D [25(OHD)]) of breastfeeding women and up to now, no information exits for German breastfeeding women. Therefore, the aim of study was to determine the vitamin D status of breastfeeding women compared to non-pregnant and non-breastfeeding (NPNB) women. Methods: This cross-sectional study investigated 124 breastfeeding women and 124 age and season matched NPNB women from the German "Vitamin and mineral status among German women" study. The study participants were recruited from April 2013 to March 2015 and did not take vitamin D supplements. Serum 25(OH)D was analyzed by chemiluminescent immunoassay. Results: Vitamin D deficiency (<25.0 nmol/L) was prevalent in 26.6% of the breastfeeding women. The majority of women (49.2%) showed 25(OH)D concentration between 25.0 and 49.9 nmol/L. In multiple binary logistic regression analysis, breastfeeding women had a 4.0-fold higher odds ratio (OR) (95% confidence interval [CI] 1.8, 8.7) for vitamin D deficiency than NPNB women. For breastfeeding women, the risk of vitamin D deficiency was higher in the winter and spring months (OR: 2.6, 95% CI 1.1, 6.3) and increased with lower longitude per one unit (OR 0.7, 95% CI 0.6, 0.9). Conclusion: Breastfeeding women in Germany had a higher risk of deficient vitamin D levels than NPNB women. In further studies, the optimal vitamin D status for breastfeeding women should be investigated and also the required vitamin D doses to ensure this vitamin D status. Trial registration: German Clinical Trial Register (identification number: DRKS00004789 ).Rottapharm Madaus GmbHMeda A

The Bioavailability of Vitamin E in Fortified Processed Foods

Objectives: Vitamin E is an important human lipophilic antioxidant and is required for many metabolic functions. A high vitamin E intake appears to favorably impact a variety of disease processes. The vitamin E intake, excluding sup-plemental intake, of the vast majority of adults is below the current recommended level. By consuming vitamin E-enriched food, it is possible to take in adequate amounts of vitamin E. Vitamin E intake from enriched foods might prevent certain diseases without the need to ingest specific vitamin E supplements. The vitamin E that is present in enriched foods has to exhibit maximal bioavailability to ensure a sufficient intake of vitamin E from one portion of fortified food. The aim of the present study was to develop an enriched food that has highly bioavailable vitamin E. Furthermore, we wanted to examine whether vitamin E bioavailability can be affected by the technological properties of fortified food. Methods: Volunteers were given test foods (cream cheese and mayonnaise) that had been fortified with 60 mg of RRR-α-tocopherol. The test foods were technologically modified and the bioavailability of RRR-α-tocopherol was determined via a short-term kinetic measurement, which was 24 h long, and a long-term kinetic measurement, which was 28 d long. The test foods were characterized with respect to matrix properties. Results: In comparison to the mayonnaise group the serum α-tocopherol area under the curve (AUC) was significantly higher in the cream cheese group, as shown in the short-term kinetic (p = 0.010) and long-term kinetic (p = 0.017) studies. Conclusions: In conclusion, RRR-α-tocopherol was more bioavailable in cream cheese than in mayonnaise in both short-term and long-term periods. Hence, food matrices affect bioavailability of RRR-α-tocopherol. Fortified foods with proven high α-tocopherol bioavailabilities could be merchandised as functional foods with diseases prevention properties.Ministry of Science and Culture of Lower Saxon

A Highly Accurate Query-Recovery Attack against Searchable Encryption using Non-Indexed Documents

Cloud data storage solutions offer customers cost-effective and reduced data management. While attractive, data security issues remain to be a core concern. Traditional encryption protects stored documents, but hinders simple functionalities such as keyword search. Therefore, searchable encryption schemes have been proposed to allow for the search on encrypted data. Efficient schemes leak at least the access pattern (the accessed documents per keyword search), which is known to be exploitable in query recovery attacks assuming the attacker has a significant amount of background knowledge on the stored documents. Existing attacks can only achieve decent results with strong adversary models (e.g. at least 20% of previously known documents or require additional knowledge such as on query frequencies) and they give no metric to evaluate the certainty of recovered queries. This hampers their practical utility and questions their relevance in the real-world. We propose a refined score attack which achieves query recovery rates of around 85% without requiring exact background knowledge on stored documents; a distributionally similar, but otherwise different (i.e., non-indexed), dataset suffices. The attack starts with very few known queries (around 10 known queries in our experiments over different datasets of varying size) and then iteratively recovers further queries with confidence scores by adding previously recovered queries that had high confidence scores to the set of known queries. Additional to high recovery rates, our approach yields interpretable results in terms of confidence scores.Comment: Published in USENIX 2021. Full version with extended appendices and removed some typo