147 research outputs found
Short-term changes observed in multi-parametric liver MRI following therapy with direct acting antivirals in chronic hepatitis C virus patients
Methods: We applied multiparametric MRI to assess changes in liver composition, perfusion and blood flow in 17 patients before DAA therapy and after treatment completion (within 12 weeks of last DAA tablet swallowed).Results: We observed changes in hepatic composition indicated by a reduction in both liver longitudinal relaxation time (T1, 35±4 ms), transverse relaxation time (T2, 2.5±0.8 ms; T2* 3.0±0.7 ms) and liver perfusion (28.1±19.7ml/100g/min) which we suggest are linked to reduced pro-inflammatory milieu, including interstitial oedema, within the liver. No changes were observed in liver or spleen blood flow, splenic perfusion, or SMA blood flow.Conclusion: For the first time, our study has shown that treatment of HCV with DAAs in patients with cirrhosis leads to an acute reduction in liver T1, T2, T2* and an increase in liver perfusion measured using MR parameters. The ability of MRI to characterise changes in the angio-architecture of patients with cirrhosis after intervention in the short term will enhance our understanding of the natural history of regression of liver disease and potentially influence clinical decision algorithms
Gravitational Geometric Phase in the Presence of Torsion
We investigate the relativistic and non-relativistic quantum dynamics of a
neutral spin-1/2 particle submitted an external electromagnetic field in the
presence of a cosmic dislocation. We analyze the explicit contribution of the
torsion in the geometric phase acquired in the dynamic of this neutral
spinorial particle. We discuss the influence of the torsion in the relativistic
geometric phase. Using the Foldy-Wouthuysen approximation, the non-relativistic
quantum dynamics are studied and the influence of the torsion in the
Aharonov-Casher and He-McKellar-Wilkens effects are discussed.Comment: 14 pages, no figur
Quantum mechanics: Myths and facts
A common understanding of quantum mechanics (QM) among students and practical
users is often plagued by a number of "myths", that is, widely accepted claims
on which there is not really a general consensus among experts in foundations
of QM. These myths include wave-particle duality, time-energy uncertainty
relation, fundamental randomness, the absence of measurement-independent
reality, locality of QM, nonlocality of QM, the existence of well-defined
relativistic QM, the claims that quantum field theory (QFT) solves the problems
of relativistic QM or that QFT is a theory of particles, as well as myths on
black-hole entropy. The fact is that the existence of various theoretical and
interpretational ambiguities underlying these myths does not yet allow us to
accept them as proven facts. I review the main arguments and counterarguments
lying behind these myths and conclude that QM is still a
not-yet-completely-understood theory open to further fundamental research.Comment: 51 pages, pedagogic review, revised, new references, to appear in
Found. Phy
Young-Onset Gastrointestinal Adenocarcinoma Incidence and Survival Trends in the Northern Territory, Australia, with Emphasis on Indigenous Peoples
Background and Aims: A concerning rise in incidence of young-onset cancers globally led to the examination of trends in incidence and survival of gastrointestinal (GI) adenocarcinomas in the Northern Territory (NT), Australia, over a 28-year period, with a special emphasis on Indigenous peoples. Methods: This cross-sectional analysis of a prospective longitudinal database, NT Cancer Registry (1990–2017), includes all reported cases of GI (oesophagus, gastric, small intestinal, pancreas, colon, and rectum) adenocarcinomas. Poisson regression was used to estimate incidence ratio ratios, and survival was modelled using Cox proportional hazard models separately for people aged 18–50 years and >50 years. Results: A total of 1608 cases of GI adenocarcinoma were recorded during the time of the study. While the overall incidence in people 18–50 years remained unchanged over this time (p = 0.51), the rate in individuals aged >50 years decreased (IRR = 0.65 (95% CI 0.56–0.75; p 50 years (IRR = 0.67 95% CI 0.59–0.75; p 50 years IRR = 0.48 95% CI 0.40–0.57; p 50 years HR = 1.66 95% CI 1.32–2.08; p < 0.0001). Conclusions: There is a trend towards an increased incidence of young-onset GI adenocarcinomas in the NT. Young Indigenous patients have lower incidence but worse survival across all GI subsites, highlighting significant health inequities in life expectancy. Targeted, culturally safe Indigenous community-focussed programs are needed for early detection and patient-centred management of GI adenocarcinomas.Mia Shepherdson, Shalem Leemaqz, Gurmeet Singh, Courtney Ryder, Shahid Ullah, Karla Canuto, Joanne P. Young, Timothy J. Price, Ross A. McKinnon, Stephen J. Pandol, Claire T. Roberts, and Savio George Barret
The influence of first generation fertility and economic status on second generation fertility
This paper examines the impact of parental economic status and family size on the actual and expected fertility of adult children using longitudinal data from two generations of families participating in the Panel Study of Income Dynamics. There was a modest positive relationship between first generation family size and second generation fertility. More importantly, the ideal family size of the parental family was more closely related to fertility behavior and plans in the second generation than was actual parental family size. In addition, the data revealed the hypothesized negative correlation between parental financial status and second generation fertility behavior and plans. Several mechanisms which could produce the correlation between parental characteristics and the fertility of their children are explored.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43511/1/11111_2005_Article_BF01253070.pd
Supervisors' Perceptions of the Performance of Cooperative Education Employees Working in Federal Agencies
Through cooperative education programs, many public agencies employ college students part time or intermittently and groom them for future full-time employment The combination of winnowing and nurturing that occurs in these programs is believed to produce higher performing employees This study tests this hypothesis by comparing Federal supervisors' perceptions of the performance of co-op employees with those recruited from other sources Data come from the 1992 Merit Principles Survey, US Merit Systems Protection Board The results indicate that co-op employees perform at high levels, but they do not outperform other employees as a whole Next, we compare the performance ratings of Federal workers from seven other recruitment sources to see if any source is superior Some interesting findings emerge Of course, performance ratings are an incomplete indicator of an employee's value to the organization These ratings merely reflect supervisors' perceptions, and while high performance is important, agencies may wish to promote other goals in their recruitment and retention efforts such as workforce diversityYeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
The value of children to parents in the United States
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43479/1/11111_2004_Article_BF01277597.pd
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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