1,057 research outputs found

    Counterexample-Guided Polynomial Loop Invariant Generation by Lagrange Interpolation

    Full text link
    We apply multivariate Lagrange interpolation to synthesize polynomial quantitative loop invariants for probabilistic programs. We reduce the computation of an quantitative loop invariant to solving constraints over program variables and unknown coefficients. Lagrange interpolation allows us to find constraints with less unknown coefficients. Counterexample-guided refinement furthermore generates linear constraints that pinpoint the desired quantitative invariants. We evaluate our technique by several case studies with polynomial quantitative loop invariants in the experiments

    Winter wheat roots grow twice as deep as spring wheat roots, is this important for N uptake and N leaching losses?

    Get PDF
    Cropping systems comprising winter catch crops followed by spring wheat could reduce N leaching risks compared to traditional winter wheat systems in humid climates. We studied the soil mineral N (Ninorg) and root growth of winter- and spring wheat to 2.5 m depth during three years. Root depth of winter wheat (2.2 m) was twice that of spring wheat, and this was related to much lower amounts of Ninorg in the 1 to 2.5 m layer after winter wheat (81 kg Ninorg ha-1 less). When growing winter catch crops before spring wheat, N content in the 1 to 2.5 m layer after spring wheat was not different from that after winter wheat. The results suggest that by virtue of its deep rooting, winter wheat may not lead to high levels of leaching as it is often assumed in humid climates. Deep soil and root measurements (below 1 m) in this experiment were essential to answer the questions we posed

    Betibeglogene Autotemcel Gene Therapy for Non-β⁰/β⁰ Genotype β-Thalassemia

    Get PDF
    BACKGROUND: Betibeglogene autotemcel (beti-cel) gene therapy for transfusion-dependent β-thalassemia contains autologous CD34+ hematopoietic stem cells and progenitor cells transduced with the BB305 lentiviral vector encoding the β-globin (βA-T87Q) gene. METHODS: In this open-label, phase 3 study, we evaluated the efficacy and safety of beti-cel in adult and pediatric patients with transfusion-dependent β-thalassemia and a non-β0/β0 genotype. Patients underwent myeloablation with busulfan (with doses adjusted on the basis of pharmacokinetic analysis) and received beti-cel intravenously. The primary end point was transfusion independence (i.e., a weighted average hemoglobin level of ≥9 g per deciliter without red-cell transfusions for ≥12 months). RESULTS: A total of 23 patients were enrolled and received treatment, with a median follow-up of 29.5 months (range, 13.0 to 48.2). Transfusion independence occurred in 20 of 22 patients who could be evaluated (91%), including 6 of 7 patients (86%) who were younger than 12 years of age. The average hemoglobin level during transfusion independence was 11.7 g per deciliter (range, 9.5 to 12.8). Twelve months after beti-cel infusion, the median level of gene therapy-derived adult hemoglobin (HbA) with a T87Q amino acid substitution (HbAT87Q) was 8.7 g per deciliter (range, 5.2 to 10.6) in patients who had transfusion independence. The safety profile of beti-cel was consistent with that of busulfan-based myeloablation. Four patients had at least one adverse event that was considered by the investigators to be related or possibly related to beti-cel; all events were nonserious except for thrombocytopenia (in 1 patient). No cases of cancer were observed. CONCLUSIONS: Treatment with beti-cel resulted in a sustained HbAT87Q level and a total hemoglobin level that was high enough to enable transfusion independence in most patients with a non-β0/β0 genotype, including those younger than 12 years of age. (Funded by Bluebird Bio; HGB-207 ClinicalTrials.gov number, NCT02906202.)

    Pathogen detection, testing, and control in fresh broccoli sprouts

    Get PDF
    BACKGROUND: The recent increased interest in consuming green vegetable sprouts has been tempered by the fact that fresh sprouts can in some cases be vehicles for food-borne illnesses. They must be grown according to proper conditions of sanitation and handled as a food product rather than as an agricultural commodity. When sprouts are grown in accordance with the criteria proposed from within the sprout industry, developed by regulatory agencies, and adhered to by many sprouters, green sprouts can be produced with very low risk. Contamination may occur when these guidelines are not followed. METHODS: A one year program of microbial hold-and-release testing, conducted in concert with strict seed and facility cleaning procedures by 13 U.S. broccoli sprout growers was evaluated. Microbial contamination tests were performed on 6839 drums of sprouts, equivalent to about 5 million consumer packages of fresh green sprouts. RESULTS: Only 24 (0.75%) of the 3191 sprout samples gave an initial positive test for Escherichia coli O157:H7 or Salmonella spp., and when re-tested, 3 drums again tested positive. Composite testing (e.g., pooling up to 7 drums for pathogen testing) was equally sensitive to single drum testing. CONCLUSION: By using a "test-and-re-test" protocol, growers were able to minimize crop destruction. By pooling drums for testing, they were also able to reduce testing costs which now represent a substantial portion of the costs associated with sprout growing. The test-and-hold scheme described herein allowed those few batches of contaminated sprouts to be found prior to packaging and shipping. These events were isolated, and only safe sprouts entered the food supply

    Neurons in the human amygdala encode face identity, but not gaze direction

    Get PDF
    The amygdala is important for face processing, and direction of eye gaze is one of the most socially salient facial signals. Recording from over 200 neurons in the amygdala of neurosurgical patients, we found robust encoding of the identity of neutral-expression faces, but not of their direction of gaze. Processing of gaze direction may rely on a predominantly cortical network rather than the amygdala

    Molecules cooled below the Doppler limit

    Get PDF
    The ability to cool atoms below the Doppler limit -- the minimum temperature reachable by Doppler cooling -- has been essential to most experiments with quantum degenerate gases, optical lattices and atomic fountains, among many other applications. A broad set of new applications await ultracold molecules, and the extension of laser cooling to molecules has begun. A molecular magneto-optical trap has been demonstrated, where molecules approached the Doppler limit. However, the sub-Doppler temperatures required for most applications have not yet been reached. Here we cool molecules to 50 uK, well below the Doppler limit, using a three-dimensional optical molasses. These ultracold molecules could be loaded into optical tweezers to trap arbitrary arrays for quantum simulation, launched into a molecular fountain for testing fundamental physics, and used to study ultracold collisions and ultracold chemistry

    Cardiovascular Health in Anxiety or Mood Problems Study (CHAMPS): study protocol for a randomized controlled trial

    Get PDF
    Background: Previous psychological and pharmacological interventions have primarily focused on depression disorders in populations with cardiovascular diseases (CVDs) and the efficacy of anxiety disorder interventions is only more recently being explored. Transdiagnostic interventions address common emotional processes and the full range of anxiety and depression disorders often observed in populations with CVDs. The aim of CHAMPS is to evaluate the feasibility of a unified protocol (UP) for the transdiagnostic treatment of emotional disorders intervention in patients recently hospitalized for CVDs. The current study reports the protocol of a feasibility randomized controlled trial to inform a future trial. Methods/Design: This is a feasibility randomized, controlled trial with a single-center design. A total of 50 participants will be block-randomized to either a UP intervention or enhanced usual care. Both groups will receive standard CVD care. The UP intervention consists of 1) enhancing motivation, readiness for change, and treatment engagement; (2) psychoeducation about emotions; (3) increasing present focused emotion awareness; (4) increasing cognitive flexibility; (5) identifying and preventing patterns of emotion avoidance and maladaptive emotion-driven behaviors (EDBs, including tobacco smoking, and alcohol use); (6) increasing tolerance of emotion-related physical sensations; (7) interoceptive and situation-based emotion-focused exposure; and (8) relapse prevention strategies. Treatment duration is 12 to 18 weeks. Relevant outcomes include the standard deviation of self-rated anxiety, depression and quality of life symptoms. Other outcomes include intervention acceptability, satisfaction with care, rates of EDBs, patient adherence, physical activity, cardiac and psychiatric readmissions. Parallel to the main trial, a nonrandomized comparator cohort will be recruited comprising 150 persons scoring below the predetermined depression and anxiety severity thresholds. Discussion: CHAMPS is designed to evaluate the UP for the transdiagnostic treatment of emotional disorders targeting emotional disorder processes in a CVD population. The design will provide preliminary evidence of feasibility, attrition, and satisfaction with treatment to design a definitive trial. If the trial is feasible, it opens up the possibility for interventions to target broader emotional processes in the precarious population with CVD and emotional distress.Phillip J. Tully, Deborah A. Turnbull, John D. Horowitz, John F. Beltrame, Terina Selkow, Bernhard T. Baune, Elizabeth Markwick, Shannon Sauer-Zavala, Harald Baumeister, Suzanne Cosh and Gary A. Witter
    • …
    corecore