40 research outputs found

    Overview of the SME: Implications and Phenomenology of Lorentz Violation

    Full text link
    The Standard Model Extension (SME) provides the most general observer-independent field theoretical framework for investigations of Lorentz violation. The SME lagrangian by definition contains all Lorentz-violating interaction terms that can be written as observer scalars and that involve particle fields in the Standard Model and gravitational fields in a generalized theory of gravity. This includes all possible terms that could arise from a process of spontaneous Lorentz violation in the context of a more fundamental theory, as well as terms that explicitly break Lorentz symmetry. An overview of the SME is presented, including its motivations and construction. Some of the theoretical issues arising in the case of spontaneous Lorentz violation are discussed, including the question of what happens to the Nambu-Goldstone modes when Lorentz symmetry is spontaneously violated and whether a Higgs mechanism can occur. A minimal version of the SME in flat Minkowski spacetime that maintains gauge invariance and power-counting renormalizability is used to search for leading-order signals of Lorentz violation. Recent Lorentz tests in QED systems are examined, including experiments with photons, particle and atomic experiments, proposed experiments in space and experiments with a spin-polarized torsion pendulum.Comment: 40 pages, Talk presented at Special Relativity: Will it Survive the Next 100 Years? Potsdam, Germany, February, 200

    Alcohol consumption upon direct-acting antiviral therapy for hepatitis C among persons with human immunodeficiency virus in the United States

    Get PDF
    Background: Direct-acting antivirals (DAA) are highly effective against hepatitis C virus (HCV) infection among persons with human immunodeficiency virus (PWH). However, alcohol use post-DAA treatment poses a continued threat to the liver. Whether the focus on liver health alone during HCV treatment can impact alcohol consumption is unclear. Therefore, we examined the change in alcohol use among HCV-coinfected PWH who received DAA therapy by non-addiction medical providers. Methods: In our longitudinal clinical cohort study, we identified HCV-coinfected PWH who received interferon-free DAA therapy between January 2014 and June 2019 in the Centers for AIDS Research Network of Integrated Clinical Systems. The Alcohol Use Disorders Identification Test—Consumption (AUDIT-C) was the alcohol screening instrument. We used mixed-effects logistic regression models to estimate the longitudinal change in alcohol use upon DAA therapy. Results: Among 738 HCV-coinfected PWH, 339 (46 %) reported any alcohol use at the end of HCV treatment, including 113 (15 %) with high-risk use (i.e., AUDIT-C ≥3 for women, ≥4 for men). Concurrently, 280 (38 %) PWH noted active drug use, and 357 (48 %) were currently smoking. We observed no changes in the odds of any alcohol or high-risk alcohol use over time with DAA therapy. Findings were similar in the PWH subgroup with a history of alcohol use before DAA treatment. Conclusions: For PWH with HCV, alcohol use did not change following interferon-free DAA treatment by non-addiction medical providers. Thus, clinicians should consider integrating targeted alcohol use interventions into HCV care to motivate reduced alcohol consumption and safeguard future liver health

    Factors Associated with Severity of COVID-19 Disease in a Multicenter Cohort of People with HIV in the United States, March-December 2020

    Get PDF
    Background: Understanding the spectrum of COVID-19 in people with HIV (PWH) is critical to provide clinical guidance and risk reduction strategies.Setting:Centers for AIDS Research Network of Integrated Clinic System, a US multisite clinical cohort of PWH in care.Methods:We identified COVID-19 cases and severity (hospitalization, intensive care, and death) in a large, diverse HIV cohort during March 1, 2020-December 31, 2020. We determined predictors and relative risks of hospitalization among PWH with COVID-19, adjusted for disease risk scores. Results: Of 16,056 PWH in care, 649 were diagnosed with COVID-19 between March and December 2020. Case fatality was 2%; 106 (16.3%) were hospitalized, and 12 died. PWH with current CD4 count <350 cells/mm3[aRR 2.68; 95% confidence interval (CI): 1.93 to 3.71; P < 0.001] or lowest recorded CD4 count <200 cells/mm3(aRR 1.67; 95% CI: 1.18 to 2.36; P < 0.005) had greater risks of hospitalization. HIV viral load and antiretroviral therapy status were not associated with hospitalization, although most of the PWH were suppressed (86%). Black PWH were 51% more likely to be hospitalized with COVID-19 compared with other racial/ethnic groups (aRR 1.51; 95% CI: 1.04 to 2.19; P = 0.03). Chronic kidney disease, chronic obstructive pulmonary disease, diabetes, hypertension, obesity, and increased cardiovascular and hepatic fibrosis risk scores were associated with higher hospitalization risk. PWH who were older, not on antiretroviral therapy, and with current CD4 count <350 cells/mm3, diabetes, and chronic kidney disease were overrepresented among PWH who required intubation or died. Conclusions: PWH with CD4 count <350 cells/mm3, and a history of CD4 count <200 cells/mm3, have a clear excess risk of severe COVID-19, accounting for comorbidities associated with severe outcomes. PWH with these risk factors should be prioritized for COVID-19 vaccination and early treatment and monitored closely for worsening illness

    Racial and ethnic disparities in coronavirus disease 2019 disease incidence independent of comorbidities, among people with HIV in the United States

    Get PDF
    Objectives: To define the incidence of clinically detected coronavirus disease 2019 (COVID-19) in people with HIV (PWH) in the United States and evaluate how racial and ethnic disparities, comorbidities, and HIV-related factors contribute to risk of COVID-19. Design: Observational study within the CFAR Network of Integrated Clinical Systems cohort in seven cities during 2020. Methods: We calculated cumulative incidence rates of COVID-19 diagnosis among PWH in routine care by key characteristics including race/ethnicity, current and lowest CD4þ cell count, and geographic area. We evaluated risk factors for COVID-19 among PWH using relative risk regression models adjusted with disease risk scores. Results: Among 16 056 PWH in care, of whom 44.5% were black, 12.5% were Hispanic, with a median age of 52 years (IQR 40 - 59), 18% had a current CD4þ cell count less than 350 cells/ml, including 7% less than 200; 95.5% were on antiretroviral therapy (ART), and 85.6% were virologically suppressed. Overall in 2020, 649 PWH were diagnosed with COVID-19 for a rate of 4.94 cases per 100 person-years. The cumulative incidence of COVID-19 was 2.4-fold and 1.7-fold higher in Hispanic and black PWH respectively, than non-Hispanic white PWH. In adjusted analyses, factors associated with COVID-19 included female sex, Hispanic or black identity, lowest historical CD4þ cell count less than 350 cells/ml (proxy for CD4þ nadir), current low CD4þ : CD8þ ratio, diabetes, and obesity. Conclusion: Our results suggest that the presence of structural racial inequities above and beyond medical comorbidities increased the risk of COVID-19 among PWH. PWH with immune exhaustion as evidenced by lowest historical CD4þ cell count or current low CD4þ : CD8þ ratio had greater risk of COVID-19

    Physics with the KLOE-2 experiment at the upgraded DAϕ\phiNE

    Get PDF
    Investigation at a ϕ\phi--factory can shed light on several debated issues in particle physics. We discuss: i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled kaon states, iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta^\prime mesons, iv) the contribution to understand the nature of light scalar mesons, and v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the e+ee^+ e^- physics in the continuum with the measurements of (multi)hadronic cross sections and the study of gamma gamma processes.Comment: 60 pages, 41 figures; added affiliation for one of the authors; added reference to section

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

    Get PDF
    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
    corecore