70 research outputs found
Polarized Deeply Inelastic Scattering (DIS) Structure Functions for Nucleons and Nuclei
We extract parton distribution functions (PDFs) and structure functions from
recent experimental data of polarized lepton-DIS on nucleons at next-to-leading
order (NLO) Quantum Chromodynamics. We apply the Jacobi polynomial method to
the DGLAP evolution as this is numerically efficient. Having determined the
polarized proton and neutron spin structure, we extend this analysis to
describe 3He and 3H polarized structure functions, as well as various sum
rules. We compare our results with other analyses from the literature.Comment: LaTeX, 12 pages, 11 figures, 6 tables. Update to match published
versio
Polarized Deeply Inelastic Scattering (DIS) Structure Functions for Nucleons and Nuclei
We extract parton distribution functions (PDFs) and structure functions from
recent experimental data of polarized lepton-DIS on nucleons at next-to-leading
order (NLO) Quantum Chromodynamics. We apply the Jacobi polynomial method to
the DGLAP evolution as this is numerically efficient. Having determined the
polarized proton and neutron spin structure, we extend this analysis to
describe 3He and 3H polarized structure functions, as well as various sum
rules. We compare our results with other analyses from the literature.Comment: LaTeX, 12 pages, 11 figures, 6 tables. Update to match published
versio
Study of spin-dependent structure functions of 3He and 3H at NNLO approximation and corresponding nuclear corrections
We determine polarized parton distribution functions (PPDFs) and structure functions from recent experimental data of polarized deep inelastic scattering (DIS) on nucleons at next-to-next-to-leading order (NNLO) approximation in perturbative quantum chromodynamics (pQCD). The nucleon polarized structure functions are computed using the Jacobi polynomial approach while target mass corrections (TMCs) are included in our fitting procedure. Having extracted the polarized spin structure functions, we extend our study to describe 3He
and 3H polarized structure functions, as well as the Bjorken sum rule. We also explore the importance of the nuclear corrections on the polarized nuclear structure functions at small and large values of x . Our results are compared with the recent available and high precision polarized 3He and 3H experimental data
Nucleon spin structure functions at NNLO in the presence of target mass corrections and higher twist effects
We extract polarized parton distribution functions (PPDFs), referred to as “KTA17,” together with the
highly correlated strong coupling αs from recent and up-to-date g1 and g2 polarized structure functions
world data at next-to-next-to-leading order in perturbative QCD. The stability and reliability of the results
are ensured by including nonperturbative target mass corrections as well as higher-twist terms which are
particularly important at the large-x region at low Q2. Their role in extracting the PPDFs in the nucleon is
studied. Sum rules are discussed and compared with other results from the literature. This analysis is made
by means of the Jacobi polynomials expansion technique to the DGLAP evolution. The uncertainties on the
observables and on the PPDFs throughout this paper are computed using standard Hessian error
propagation which served to provide a more realistic estimate of the PPDFs uncertainties
Mutual 3:1 subharmonic synchronization in a micromachined silicon disk resonator
We demonstrate synchronization between two intrinsically coupled oscillators that are created from two distinct vibration modes of a single micromachined disk resonator. The modes have a 3:1 subharmonic frequency relationship and cubic, non-dissipative electromechanical coupling between the modes enables their two frequencies to synchronize. Our experimental implementation allows the frequency of the lower frequency oscillator to be independently controlled from that of the higher frequency oscillator, enabling study of the synchronization dynamics. We find close quantitative agreement between the experimental behavior and an analytical coupled-oscillator model as a function of the energy in the two oscillators. We demonstrate that the synchronization range increases when the lower frequency oscillator is strongly driven and when the higher frequency oscillator is weakly driven. This result suggests that synchronization can be applied to the frequency-selective detection of weak signals and other mechanical signal processing functions
A global analysis of diffractive events at HERA
We extract diffractive parton distribution functions (DPDFs) and diffractive
structure functions from the most recent H1 and ZEUS diffractive DIS data
obtained by various methods. We consider Pomeron as an object with parton
distribution function, evolving according to the next-to-leading order (NLO)
DGLAP equations within the framework of the `Fixed Flavour Number Scheme'
(FFNS). Having performed a global fit analysis, we achieve a very good
description of all available measurements by introducing a new set of quark
distribution form for the Pomeron. We predict longitudinal and charm proton
diffractive structure function as well. Our results are compared with other
analysis from the literature.Comment: 28 Pages, 15 Figures, 3 Table
The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019
Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe
The global burden of adolescent and young adult cancer in 2019: a systematic analysis for the Global Burden of Disease Study 2019
Background: In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15–39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods: Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15–39 years to define adolescents and young adults. Findings: There were 1·19 million (95% UI 1·11–1·28) incident cancer cases and 396 000 (370 000–425 000) deaths due to cancer among people aged 15–39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59·6 [54·5–65·7] per 100 000 person-years) and high-middle SDI countries (53·2 [48·8–57·9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14·2 [12·9–15·6] per 100 000 person-years) and middle SDI (13·6 [12·6–14·8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23·5 million (21·9–25·2) DALYs to the global burden of disease, of which 2·7% (1·9–3·6) came from YLDs and 97·3% (96·4–98·1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation: Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Funding: Bill & Melinda Gates Foundation, American Lebanese Syrian Associated Charities, St Baldrick's Foundation, and the National Cancer Institute
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