Robust Fuzzy Extractors and Authenticated Key Agreement from Close Secrets

Abstract: Consider two parties holding samples from correlated distributions W and W\u27, respectively, where these samples are within distance t of each other in some metric space. The parties wish to agree on a close-to-uniformly distributed secret key R by sending a single message over an insecure channel controlled by an all-powerful adversary who may read and modify anything sent over the channel. We consider both the keyless case, where the parties share no additional secret information, and the keyed case, where the parties share a long-term secret SK_Ext that they can use to generate a sequence of session keys {R_j} using multiple pairs {(W_j,W\u27_j)}. The former has applications to, e.g., biometric authentication, while the latter arises in, e.g., the bounded-storage model with errors. We show solutions that improve upon previous work in several respects: -- The best prior solution for the keyless case with no errors (i.e., t=0) requires the min-entropy of W to exceed 2n/3, where n is the bit-length of W. Our solution applies whenever the min-entropy of W exceeds the minimal threshold n/2, and yields a longer key. -- Previous solutions for the keyless case in the presence of errors (i.e., t>0) required random oracles. We give the first constructions (for certain metrics) in the standard model. -- Previous solutions for the keyed case were stateful. We give the first stateless solution

Intraoperative pain during caesarean delivery: Incidence, risk factors and physician perception

Background: Intraoperative pain is a possible complication of neuraxial anaesthesia for caesarean delivery. There is little information available about its incidence, risk factors and physician perception. Methods: Parturients undergoing spinal anaesthesia for elective caesarean delivery were enrolled. Before surgery, parturients were asked about preoperative anxiety on a verbal numerical scale (VNS), anticipated analgesic requirement, postoperative pain levels, Spielberger STATE-TRAIT inventory index, Pain Catastrophizing Scale. After surgery, parturients were asked to answer questions (intraoperative VNS pain). The anaesthesiologist and obstetrician were asked to fill out a questionnaire asking about perceived intraoperative pain. Influence of preoperative anxiety on intraoperative pain (yes/no) was assessed using logistic regression. Mc Fadden's R2 was calculated. The agreement in physician perception of intraoperative pain with reported pain by the parturient was examined by calculating Cohen's kappa and 95% Confidence Intervals (CI). Results: We included 193 parturients in our analysis. Incidence of intraoperative pain was 11.9%. Median intraoperative VNS pain of parturients with pain was 4.0 (1st quartile 4.0; 3rd quartile 9.0). Preoperative anxiety was not a good predictor of intraoperative pain (p-value of β-coefficient = 0.43, Mc Fadden's R2 = 0.01). Including further preoperative variables did not result in a good prediction model. Cohen's kappa between reported pain by parturient and by the obstetrician was 0.21 (95% CI: 0.01, 0.41) and by the anaesthesiologist was 0.3 (95% CI: 0.12, 0.48). Conclusions: We found a substantial incidence (11.9%) of intraoperative pain during caesarean delivery. Preoperative anxiety did not predict intraoperative pain. Physicians did not accurately identify parturients' intraoperative pain. Significance: Intraoperative pain occurred in 11.9% and severe intraoperative pain occurred in 1.11% of parturients undergoing elective caesarean delivery under spinal anaesthesia. We did not find any preoperative variables that could reliably predict intraoperative pain. Obstetricians and anaesthesiologists underestimated the incidence of intraoperative pain in our cohort and thus, more attention must be put to parturients' pain

NIR Femtosecond Control of Resonance-Mediated Generation of Coherent Broadband UV Emission

We use shaped near-infrared (NIR) pulses to control the generation of coherent broadband ultraviolet (UV) radiation in an atomic resonance-mediated (2+1) three-photon excitation. Experimental and theoretical results are presented for phase controlling the total emitted UV yield in atomic sodium (Na). Based on our confirmed understanding, we present a new simple scheme for producing shaped femtosecond pulses in the UV/VUV spectral range using the control over atomic resonance-mediated generation of third (or higher order) harmonic.Comment: 14 pages, 4 figure

PHA4GE quality control contextual data tags:standardized annotations for sharing public health sequence datasets with known quality issues to facilitate testing and training

As public health laboratories expand their genomic sequencing and bioinformatics capacity for the surveillance of different pathogens, labs must carry out robust validation, training, and optimization of wet- and dry-lab procedures. Achieving these goals for algorithms, pipelines and instruments often requires that lower quality datasets be made available for analysis and comparison alongside those of higher quality. This range of data quality in reference sets can complicate the sharing of sub-optimal datasets that are vital for the community and for the reproducibility of assays. Sharing of useful, but sub-optimal datasets requires careful annotation and documentation of known issues to enable appropriate interpretation, avoid being mistaken for better quality information, and for these data (and their derivatives) to be easily identifiable in repositories. Unfortunately, there are currently no standardized attributes or mechanisms for tagging poor-quality datasets, or datasets generated for a specific purpose, to maximize their utility, searchability, accessibility and reuse. The Public Health Alliance for Genomic Epidemiology (PHA4GE) is an international community of scientists from public health, industry and academia focused on improving the reproducibility, interoperability, portability, and openness of public health bioinformatic software, skills, tools and data. To address the challenges of sharing lower quality datasets, PHA4GE has developed a set of standardized contextual data tags, namely fields and terms, that can be included in public repository submissions as a means of flagging pathogen sequence data with known quality issues, increasing their discoverability. The contextual data tags were developed through consultations with the community including input from the International Nucleotide Sequence Data Collaboration (INSDC), and have been standardized using ontologies - community-based resources for defining the tag properties and the relationships between them. The standardized tags are agnostic to the organism and the sequencing technique used and thus can be applied to data generated from any pathogen using an array of sequencing techniques. The tags can also be applied to synthetic (lab created) data. The list of standardized tags is maintained by PHA4GE and can be found at https://github.com/pha4ge/contextual_data_QC_tags. Definitions, ontology IDs, examples of use, as well as a JSON representation, are provided. The PHA4GE QC tags were tested, and are now implemented, by the FDA's GenomeTrakr laboratory network as part of its routine submission process for SARS-CoV-2 wastewater surveillance. We hope that these simple, standardized tags will help improve communication regarding quality control in public repositories, in addition to making datasets of variable quality more easily identifiable. Suggestions for additional tags can be submitted to PHA4GE via the New Term Request Form in the GitHub repository. By providing a mechanism for feedback and suggestions, we also expect that the tags will evolve with the needs of the community.</p

Amplitude Spectroscopy of a Solid-State Artificial Atom

The energy-level structure of a quantum system plays a fundamental role in determining its behavior and manifests itself in a discrete absorption and emission spectrum. Conventionally, spectra are probed via frequency spectroscopy whereby the frequency \nu of a harmonic driving field is varied to fulfill the conditions \Delta E = h \nu, where the driving field is resonant with the level separation \Delta E (h is Planck's constant). Although this technique has been successfully employed in a variety of physical systems, including natural and artificial atoms and molecules, its application is not universally straightforward, and becomes extremely challenging for frequencies in the range of 10's and 100's of gigahertz. Here we demonstrate an alternative approach, whereby a harmonic driving field sweeps the atom through its energy-level avoided crossings at a fixed frequency, surmounting many of the limitations of the conventional approach. Spectroscopic information is obtained from the amplitude dependence of the system response. The resulting ``spectroscopy diamonds'' contain interference patterns and population inversion that serve as a fingerprint of the atom's spectrum. By analyzing these features, we determine the energy spectrum of a manifold of states with energies from 0.01 to 120 GHz \times h in a superconducting artificial atom, using a driving frequency near 0.1 GHz. This approach provides a means to manipulate and characterize systems over a broad bandwidth, using only a single driving frequency that may be orders of magnitude smaller than the energy scales being probed.Comment: 12 pages, 13 figure

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure &lt; 100 mmHg (n = 1127), estimated glomerular filtration rate &lt; 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation