25 research outputs found

    Azimuthally sensitive Hanbury Brown-Twiss interferometry in Au+Au collisions at sqrt(s_{NN}) = 200 GeV

    Get PDF
    We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii vs. emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape.Comment: 6 pages, 4 figures, published versio

    ρ\u3csup\u3e0\u3c/sup\u3e production and possible modification in Au + Au and p + p collisions at √s\u3csub\u3eNN\u3c/sub\u3e = 200 GeV

    Get PDF
    We report results on ρ(770)0→π+π− production at midrapidity in p+p and peripheral Au+Au collisions at √sNN=200  GeV. This is the first direct measurement of ρ(770)0→π+π− in heavy-ion collisions. The measured ρ0 peak in the invariant mass distribution is shifted by ∼40  MeV/c2 in minimum bias p+p interactions and ∼70  MeV/c2 in peripheral Au+Au collisions. The ρ0 mass shift is dependent on transverse momentum and multiplicity. The modification of the ρ0 meson mass, width, and shape due to phase space and dynamical effects are discussed

    Distributions of charged hadrons associated with high transverse momentum particles in pp and Au plus Au collisions at root(S)(NN)=200 GeV

    Get PDF
    Charged hadrons in 0.15 4 GeV/c are reconstructed in pp and Au+Au collisions at root s(NN)=200 GeV. The associated multiplicity and p(perpendicular to) magnitude sum are found to increase from pp to central Au+Au collisions. The associated p(perpendicular to) distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed

    Patients With Adhesive Small Bowel Obstruction Should Be Primarily Managed By A Surgical Team

    No full text
    Objective: To evaluate the impact of a primary medical versus surgical service on healthcare utilization and outcomes for adhesive small bowel obstruction (SBO) admissions. Summary Background Data: Adhesive-SBO typically requires hospital admission and is associated with high healthcare utilization and costs. Given that most patients are managed nonoperatively, many patients are admitted to medical hospitalists. However, comparisons of outcomes between primary medical and surgical services have been limited to small single-institution studies. Methods: Unscheduled adhesive-SBO admissions in NY State from 2002 to 2013 were identified using the Statewide Planning and Research Cooperative System. Bivariate and mixed-effects regression analyses were performed assessing factors associated with healthcare utilization and outcomes for SBO admissions. Results: Among 107,603 admissions for adhesive-SBO (78% nonoperative, 22% operative), 43% were primarily managed by a medical attending and 57% were managed by a surgical attending. After controlling for patient, physician, and hospital-level factors, management by a medical service was independently associated with longer length of stay [IRR = 1.39, 95% confidence interval (CI) = 1.24, 1.56], greater inpatient costs (IRR = 1.38, 95% = 1.21, 1.57), and a higher rate of 30-day readmission (OR = 1.32, 95% CI= 1.22, 1.42) following nonoperative management. Similarly, of those managed operatively, management by a medicine service was associated with a delay in time to surgical intervention (IRR = 1.84, 95% CI = 1.69, 2.01), extended length of stay (IRR=1.36, 95% CI = 1.25, 1.49), greater inpatient costs (IRR = 1.38, 95% CI = 1.11, 1.71), and higher rates of 30-day mortality (OR = 1.92, 95% CI = 1.50, 2.47) and 30-day readmission (OR = 1.13, 95% CI = 0.97, 1.32). Conclusions: This study suggests that management of patients presenting with adhesive-SBO by a primary medical team is associated with higher healthcare utilization and worse perioperative outcomes. Policies favoring primary management by a surgical service may improve outcomes and reduce costs for patients admitted with adhesive-SBO

    Learning-based fully automated prediction of lumbar disc degeneration progression with specified clinical parameters and preliminary validation

    No full text
    Abstract Background: Lumbar disc degeneration (LDD) may be related to aging, biomechanical and genetic factors. Despite the extensive work on understanding its etiology, there is currently no automated tool for accurate prediction of its progression. Purpose: We aim to establish a novel deep learning-based pipeline to predict the progression of LDD-related findings using lumbar MRIs. Materials and methods: We utilized our dataset with MRIs acquired from 1,343 individual participants (taken at the baseline and the 5-year follow-up timepoint), and progression assessments (the Schneiderman score, disc bulging, and Pfirrmann grading) that were labelled by spine specialists with over ten years clinical experience. Our new pipeline was realized by integrating the MRI-SegFlow and the Visual Geometry Group-Medium (VGG-M) for automated disc region detection and LDD progression prediction correspondingly. The LDD progression was quantified by comparing the Schneiderman score, disc bulging and Pfirrmann grading at the baseline and at follow-up. A fivefold cross-validation was conducted to assess the predictive performance of the new pipeline. Results: Our pipeline achieved very good performances on the LDD progression prediction, with high progression prediction accuracy of the Schneiderman score (Accuracy: 90.2 ± 0.9%), disc bulging (Accuracy: 90.4% ± 1.1%), and Pfirrmann grading (Accuracy: 89.9% ± 2.1%). Conclusions: This is the first attempt of using deep learning to predict LDD progression on a large dataset with 5-year follow-up. Requiring no human interference, our pipeline can potentially achieve similar predictive performances in new settings with minimal efforts

    Azimuthally sensitive hanbury brown-twiss interferometry in Au+Au collisions at root s(NN)=200 GeV

    Get PDF
    We present the results of a systematic study of the shape of the pion distribution in coordinate space at freeze-out in Au+Au collisions at BNL RHIC using two-pion Hanbury Brown-Twiss (HBT) interferometry. Oscillations of the extracted HBT radii versus emission angle indicate sources elongated perpendicular to the reaction plane. The results indicate that the pressure and expansion time of the collision system are not sufficient to completely quench its initial shape

    Distributions of charged hadrons associated with high transverse momentum particles in pp and Au plus Au collisions at root(S)(NN)=200 GeV

    Get PDF
    Charged hadrons in 0.15 \u3c p(perpendicular to)\u3c 4 GeV/c associated with particles of p(perpendicular to)(trig)\u3e 4 GeV/c are reconstructed in pp and Au+Au collisions at root s(NN)=200 GeV. The associated multiplicity and p(perpendicular to) magnitude sum are found to increase from pp to central Au+Au collisions. The associated p(perpendicular to) distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed
    corecore