2,361 research outputs found

    High-Energy Collision of Quarks and Mesons in the Schwinger Model: From Tensor Networks to Circuit QED

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    With the aim of studying nonperturbative out-of-equilibrium dynamics of high-energy particle collisions on quantum simulators, we investigate the scattering dynamics of lattice quantum electrodynamics in 1+1 dimensions. Working in the bosonized formulation of the model and in the thermodynamic limit, we use uniform-matrix-product-state tensor networks to construct multi-particle wave-packet states, evolve them in time, and detect outgoing particles post collision. This facilitates the numerical simulation of scattering experiments in both confined and deconfined regimes of the model at different energies, giving rise to rich phenomenology, including inelastic production of quark and meson states, meson disintegration, and dynamical string formation and breaking. We obtain elastic and inelastic scattering cross sections, together with time-resolved momentum and position distributions of the outgoing particles. Furthermore, we propose an analog circuit-QED implementation of the scattering process that is native to the platform, requires minimal ingredients and approximations, and enables practical schemes for particle wave-packet preparation and evolution. This study highlights the role of classical and quantum simulation in enhancing our understanding of scattering processes in quantum field theories in real time.Comment: 5+12 pages, 4+6 figures, close to published versio

    The prevention of lower urinary tract symptoms (PLUS) research consortium: A transdisciplinary approach toward promoting bladder health and preventing lower urinary tract symptoms in women across the life course

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    Lower urinary tract symptoms (LUTS) are highly prevalent in women, and are expected to impose a growing burden to individuals and society as the population ages. The predominance of research related to LUTS has focused on underlying pathology, disease mechanisms, or the efficacy of treatments for women with LUTS. Although this research has been vital for helping to reduce or ameliorate LUTS conditions, it has done little to prevent the onset of LUTS. Health promotion and prevention require an expansion of scientific inquiry beyond the traditional paradigm of studying disease mechanisms and treatment to the creation of an evidence base to support recommendations for bladder health promotion and, in turn, prevention of LUTS. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) introduced the concept of prevention as an important priority for women's urologic research as a prelude to supporting the formation of the Prevention of Lower Urinary Tract Symptoms (PLUS) research consortium. In this article, we introduce the PLUS research consortium to the scientific community; share the innovative paradigms by which the consortium operates; and describe its unique research mission: to identify factors that promote bladder health across the life course and prevent the onset of LUTS in girls and women

    Palliative gastrostomy in the setting of voluminous ascites

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    Objective: We report the indications, methods, and complications of percutaneous gastrostomy/gastrojejunostomy (G/GJ) in patients with voluminous ascites. Methods: Following institutional review board approval, 69 patients (14 male, 55 female, mean age 58±12 years, range 32–89 years) who underwent percutaneous G/GJ with paracentesis were identified from a prospectively acquired database. Electronic medical record data extracted included diagnosis, method of G/GJ insertion, clinical course, and complications, which were graded by The Society of Interventional Radiology (SIR) criteria. Statistics were performed using Graphpad Instat. Results: Sixty-six G and three GJ catheters were placed in 62 patients with malignant and 7 patients with benign disease; 47 procedures were conducted using fluoroscopy and 22 using computed tomography (CT; 10 patients had failed fluoroscopy). Sixty-six patients had 1980±1371 mL (range, 20–5000 mL) ascites drained (more in males, p=0.01) 0.8±1.6 days (range, 0–5 days) prior to placement. Forty-one patients had significantly less ascites (1895±1426 mL; range, 100–5400 mL) drained after G/GJ (p>0.0.5). Mean survival after insertion was 43±57 days (range, 1–252 days) among 38 patients for whom data were available. Fifty-six patients had a mean postprocedure hospital stay of 8.6±8.4 days (range, 0–45 days); 3 were outpatients and 10 patients died in the hospital. Successful gastropexy was confirmed on subsequent cross-sectional imaging in 22 of 25 patients. There were 25 tube maintenance issues that included catheter displacement and leakage, one patient experienced hemorrhage, and there were two deaths. All except one patient had satisfactory gastrostomy function. Conclusion: Effective G/GJ placement is possible in most patients with voluminous ascites provided ascites is drained and gastrocutaneous fistula formation occurs. Caution is advised; placement is generally for fragile terminal patients, and fluoroscopy or CT guidance is required

    Oral human papillomavirus is common in individuals with Fanconi anemia

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    Fanconi anemia is a rare genetic disorder resulting in a loss of function of the Fanconi anemia-related DNA repair pathway. Individuals with Fanconi anemia are predisposed to some cancers, including oropharyngeal and gynecologic cancers, with known associations with human papillomavirus (HPV) in the general population. As individuals with Fanconi anemia respond poorly to chemotherapy and radiation, prevention of cancer is critical. METHODS: To determine whether individuals with Fanconi anemia are particularly susceptible to oral HPV infection, we analyzed survey-based risk factor data and tested DNA isolated from oral rinses from 126 individuals with Fanconi anemia and 162 unaffected first-degree family members for 37 HPV types. RESULTS: Fourteen individuals (11.1%) with Fanconi anemia tested positive, significantly more (P = 0.003) than family members (2.5%). While HPV prevalence was even higher for sexually active individuals with Fanconi anemia (17.7% vs. 2.4% in family; P = 0.003), HPV positivity also tended to be higher in the sexually inactive (8.7% in Fanconi anemia vs. 2.9% in siblings). Indeed, having Fanconi anemia increased HPV positivity 4.9-fold (95% CI, 1.6-15.4) considering age and sexual experience, but did not differ by other potential risk factors. CONCLUSION: Our studies suggest that oral HPV is more common in individuals with Fanconi anemia. It will be essential to continue to explore associations between risk factors and immune dysfunction on HPV incidence and persistence over time. IMPACT: HPV vaccination should be emphasized in those with Fanconi anemia as a first step to prevent oropharyngeal cancers, although additional studies are needed to determine whether the level of protection it offers in this population is adequate

    Does urethral competence affect urodynamic voiding parameters in women with prolapse?

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    Aims To (1) compare voiding parameters and (2) correlate symptoms and urodynamic findings in women with pelvic organ prolapse (POP) and varying degrees of urethral competence. Methods We compared three groups of women with stages II–IV POP. Groups 1 and 2 were symptomatically stress continent women participating in the Colpopexy and Urinary Reduction Efforts (CARE) trial; during prolapse reduction before sacrocolpopexy, Group 1 (n = 67) did not have and Group 2 (n = 84) had urodynamic stress incontinence (USI) during prolapse reduction. Group 3 participants (n = 74), recruited specifically for this study, had stress urinary incontinence (SUI) symptoms and planned sacrocolpopexy. Participants completed standardized uroflowmetry, pressure voiding studies, and validated symptom questionnaires. Results Subjects' median age was 61 years, median parity 3 and 87% had stage III or IV POP. Fourteen percent of women in Group 3 demonstrated USI without, and 70% with, prolapse reduction. Women in Groups 2 and 3 had more detrusor overactivity (DO) than Group 1 (17 and 24% vs. 6%, P  = 0.02) and detrusor overactivity incontinence (DOI) (15 and 8% vs. 0%, P  = 0.004). Based on the Blaivis–Groutz nomogram, 60% of all women were obstructed. Post-void residual volume (PVR), peak flow rate, detrusor pressure at peak flow, voiding mechanisms, voiding patterns, obstruction and urinary retention did not differ among groups. Women in Group 3 had higher irritative and obstructive symptom scores than Group 1 or 2; neither score differed by presence of DO nor obstruction, respectively. Conclusion Women with POP have significant rates of urodynamic obstruction and retention, independent of their continence status. Symptoms of obstruction and retention correlate poorly with urodynamic findings. Neurourol. Urodynam. 26:1030–1035, 2007. © 2007 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57365/1/20436_ftp.pd

    A scoping review of mathematical models of Plasmodium vivax

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    Plasmodium vivax is one of the most geographically widespread malaria parasites in the world due to its ability to remain dormant in the human liver as hypnozoites and subsequently reactivate after the initial infection (i.e. relapse infections). More than 80% of P. vivax infections are due to hypnozoite reactivation. Mathematical modelling approaches have been widely applied to understand P. vivax dynamics and predict the impact of intervention outcomes. In this article, we provide a scoping review of mathematical models that capture P. vivax transmission dynamics published between January 1988 and May 2023 to provide a comprehensive summary of the mathematical models and techniques used to model P. vivax dynamics. We aim to assist researchers working on P. vivax transmission and other aspects of P. vivax malaria by highlighting best practices in currently published models and highlighting where future model development is required. We provide an overview of the different strategies used to incorporate the parasite's biology, use of multiple scales (within-host and population-level), superinfection, immunity, and treatment interventions. In most of the published literature, the rationale for different modelling approaches was driven by the research question at hand. Some models focus on the parasites' complicated biology, while others incorporate simplified assumptions to avoid model complexity. Overall, the existing literature on mathematical models for P. vivax encompasses various aspects of the parasite's dynamics. We recommend that future research should focus on refining how key aspects of P. vivax dynamics are modelled, including the accumulation of hypnozoite variation, the interaction between P. falciparum and P. vivax, acquisition of immunity, and recovery under superinfection
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