324 research outputs found

    An Exponential Reduction in Training Data Sizes for Machine Learning Derived Entanglement Witnesses

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    We propose a support vector machine (SVM) based approach for generating an entanglement witness that requires exponentially less training data than previously proposed methods. SVMs generate hyperplanes represented by a weighted sum of expectation values of local observables whose coefficients are optimized to sum to a positive number for all separable states and a negative number for as many entangled states as possible near a specific target state. Previous SVM-based approaches for entanglement witness generation used large amounts of randomly generated separable states to perform training, a task with considerable computational overhead. Here, we propose a method for orienting the witness hyperplane using only the significantly smaller set of states consisting of the eigenstates of the generalized Pauli matrices and a set of entangled states near the target entangled states. With the orientation of the witness hyperplane set by the SVM, we tune the plane's placement using a differential program that ensures perfect classification accuracy on a limited test set as well as maximal noise tolerance. For NN qubits, the SVM portion of this approach requires only O(6N)O(6^N) training states, whereas an existing method needs O(24N)O(2^{4^N}). We use this method to construct witnesses of 4 and 5 qubit GHZ states with coefficients agreeing with stabilizer formalism witnesses to within 6.5 percent and 1 percent, respectively. We also use the same training states to generate novel 4 and 5 qubit W state witnesses. Finally, we computationally verify these witnesses on small test sets and propose methods for further verification.Comment: 22 Pages, 3 Figure

    Beyond the Interface Limit: Structural and Magnetic Depth Profiles of Voltage-Controlled Magneto-Ionic Heterostructures

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    Electric-field control of magnetism provides a promising route towards ultralow power information storage and sensor technologies. The effects of magneto-ionic motion have so far been prominently featured in the direct modification of interface chemical and physical characteristics. Here we demonstrate magnetoelectric coupling moderated by voltage-driven oxygen migration beyond the interface limit in relatively thick AlOx/GdOx/Co (15 nm) films. Oxygen migration and its ramifications on the Co magnetization are quantitatively mapped with polarized neutron reflectometry under thermal and electro-thermal conditionings. The depth-resolved profiles uniquely identify interfacial and bulk behaviors and a semi-reversible suppression and recovery of the magnetization. Magnetometry measurements show that the conditioning changes the microstructure so as to disrupt long-range ferromagnetic ordering, resulting in an additional magnetically soft phase. X-ray spectroscopy confirms electric field induced changes in the Co oxidation state but not in the Gd, suggesting that the GdOx transmits oxygen but does not source or sink it. These results together provide crucial insight into controlling magnetic heterostructures via magneto-ionic motion, not only at the interface, but also throughout the bulk of the films

    The Development of a Patient-Reported Outcome Measure for Assessment of Genital Psoriasis Symptoms: The Genital Psoriasis Symptoms Scale (GPSS)

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    INTRODUCTION: Patient-reported outcome measures (PROs) specific for genital psoriasis (GenPs) have not been described. METHODS: In this cross-sectional, qualitative study in patients with moderate-to-severe GenPs, we sought to develop a PRO useful for GenPs symptom assessment. A literature review was performed to identify relevant psoriasis or GenPs symptoms and existing PROs that may be useful in the evaluation of symptom severity in GenPs patients. The literature review findings were discussed with clinicians, and then patients with GenPs. RESULTS: Relevant psoriasis or GenPs symptoms from the literature review included itch, pain, scaling, redness/erythema, and stinging/burning. The validity of these symptoms for GenPs and potentially relevant PROs was corroborated by clinical experts. After gap analysis, a draft symptom scale consisting of Numeric Rating Scale (NRS) items was constructed. We then conducted interviews with GenPs patients (n = 20) to support content validity and use of the draft symptom NRS items in routine practice and in clinical trials. Participants identified and confirmed relevant symptoms and evaluated the utility of the draft PRO. A new PRO was developed: the Genital Psoriasis Symptoms Scale (GPSS). Cognitive debriefing and cultural adaptation/translation interviews with a second group of patients confirmed cultural appropriateness of the GPSS. CONCLUSION: The GPSS may be useful for assessing symptoms before, during, and after treatment in routine clinical practice and in clinical trials involving patients with GenPs. FUNDING: Eli Lilly & Company. Plain language summary available for this article

    The Development of the Genital Psoriasis Sexual Frequency Questionnaire (GenPs-SFQ) to Assess the Impact of Genital Psoriasis on Sexual Health

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    INTRODUCTION: Patient-reported outcome measures (PROs) exist for psoriasis but not genital psoriasis (GenPs). METHODS: This cross-sectional, qualitative study in patients with moderate-to-severe GenPs was conducted to support development of a PRO for measuring the impact of GenPs on sexual activity and to establish content validity. The impacts of GenPs were identified in a literature review. Findings from the literature review were discussed with clinicians, and then patients with GenPs were interviewed. RESULTS: From the literature review, 52 articles, 44 abstracts, and 41 clinical trials met predefined search criteria. Of these, 11 concepts emerged as having theoretical support for use as measurable impacts of psoriasis symptoms on patients; these concepts included sexual functioning and general health-related quality of life (HRQoL). These concepts were confirmed and expanded upon by two clinicians who routinely care for patients with GenPs. Interviews were then conducted with GenPs patients (n = 20) to discuss the impact of GenPs on their HRQoL. Eighty percent of patients reported that GenPs impacted sexual frequency. The two-item GenPs Sexual Frequency Questionnaire (GenPs-SFQ) was developed to assess limitations on sexual activity frequency because of GenPs. Cognitive debriefing with an additional 50 patients with GenPs confirmed the utility and understandability of the GenPs-SFQ. CONCLUSION: The GenPs-SFQ may have utility in clinical trials involving GenPs patients and in routine clinical practice. FUNDING: Eli Lilly and Company. Plain language summary available for this article

    Ionic Tuning of Cobaltites at the Nanoscale

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    Control of materials through custom design of ionic distributions represents a powerful new approach to develop future technologies ranging from spintronic logic and memory devices to energy storage. Perovskites have shown particular promise for ionic devices due to their high ion mobility and sensitivity to chemical stoichiometry. In this work, we demonstrate a solid-state approach to control of ionic distributions in (La,Sr)CoO3_{3} thin films. Depositing a Gd capping layer on the perovskite film, oxygen is controllably extracted from the structure, up-to 0.5 O/u.c. throughout the entire 36 nm thickness. Commensurate with the oxygen extraction, the Co valence state and saturation magnetization show a smooth continuous variation. In contrast, magnetoresistance measurements show no-change in the magnetic anisotropy and a rapid increase in the resistivity over the same range of oxygen stoichiometry. These results suggest significant phase separation, with metallic ferromagnetic regions and oxygen-deficient, insulating, non-ferromagnetic regions, forming percolated networks. Indeed, X-ray diffraction identifies oxygen-vacancy ordering, including transformation to a brownmillerite crystal structure. The unexpected transformation to the brownmillerite phase at ambient temperature is further confirmed by high-resolution scanning transmission electron microscopy which shows significant structural - and correspondingly chemical - phase separation. This work demonstrates room-temperature ionic control of magnetism, electrical resistivity, and crystalline structure in a 36 nm thick film, presenting new opportunities for ionic devices that leverage multiple material functionalities

    A Survey of Laboratory and Statistical Issues Related to Farmworker Exposure Studies

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    Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final data analysis and interpretation. Similarly, data quality plays a significant role in the overall value of the study. Data quality can be derived from several experimental parameters including statistical design of the study and quality of environmental and biological analytical measurements. We discuss statistical and analytic issues that should be addressed in every farmworker study. These issues include study design and sample size determination, analytical methods and quality control and assurance, treatment of missing data or data below the method’s limits of detection, and post-hoc analyses of data from multiple studies

    Using Real-World Data to Guide Ustekinumab Dosing Strategies for Psoriasis: A Prospective Pharmacokinetic-Pharmacodynamic Study.

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    Variation in response to biologic therapy for inflammatory diseases, such as psoriasis, is partly driven by variation in drug exposure. Real-world psoriasis data were used to develop a pharmacokinetic/pharmacodynamic (PK/PD) model for the first-line therapeutic antibody ustekinumab. The impact of differing dosing strategies on response was explored. Data were collected from a UK prospective multicenter observational cohort (491 patients on ustekinumab monotherapy, drug levels, and anti-drug antibody measurements on 797 serum samples, 1,590 measurements of Psoriasis Area Severity Index (PASI)). Ustekinumab PKs were described with a linear one-compartment model. A maximum effect (Emax ) model inhibited progression of psoriatic skin lesions in the turnover PD mechanism describing PASI evolution while on treatment. A mixture model on half-maximal effective concentration identified a potential nonresponder group, with simulations suggesting that, in future, the model could be incorporated into a Bayesian therapeutic drug monitoring "dashboard" to individualize dosing and improve treatment outcomes
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