760 research outputs found
The Dipole Formalism for the Calculation of QCD Jet Cross Sections at Next-to-Leading Order
In order to make quantitative predictions for jet cross sections in
perturbative QCD, it is essential to calculate them to next-to-leading
accuracy. This has traditionally been an extremely laborious process. Using a
new formalism, imaginatively called the dipole formalism, we are able to
construct a completely general algorithm for next-to-leading order calculations
of arbitrary jet quantities in arbitrary processes. In this paper we present
the basic ideas behind the algorithm and illustrate them with a simple example.Comment: 17 pages, 2 figures. A postscript version of this paper can be
obtained from http://surya11.cern.ch/users/seymour/pubs/nlolett.ps.Z .
Reposted version corrects several misprint
Anatomical Variation in the Position of the Umbilicus and the Implications for Laparoscopic Surgery
The Japanese model in retrospective : industrial strategies, corporate Japan and the 'hollowing out' of Japanese industry
This article provides a retrospective look at the Japanese model of industrial development. This model combined an institutional approach to production based around the Japanese Firm (Aoki's, J-mode) and strategic state intervention in industry by the Japanese Ministry of International Trade and Industry (MITI). For a long period, the alignment of state and corporate interests appeared to match the wider public interest as the Japanese economy prospered. However, since the early 1990s, the global ambitions of the corporate sector have contributed to a significant 'hollowing out' of Japan's industrial base. As the world today looks for a new direction in economic management, we suggest the Japanese model provides policy-makers with a salutary lesson in tying the wider public interest with those of the corporate sector
An Assessment of the Use of Chimpanzees in Hepatitis C Research Past, Present and Future: 1. Validity of the Chimpanzee Model
The USA is the only significant user of chimpanzees in biomedical research in the world, since many countries have banned or limited the practice due to substantial ethical, economic and scientific concerns. Advocates of chimpanzee use cite hepatitis C research as a major reason for its necessity and continuation, in spite of supporting evidence that is scant and often anecdotal. This paper examines the scientific and ethical issues surrounding chimpanzee hepatitis C research, and concludes that claims of the necessity of chimpanzees in historical and future hepatitis C research are exaggerated and unjustifiable, respectively. The chimpanzee model has several major scientific, ethical, economic and practical caveats. It has made a relatively negligible contribution to knowledge of, and tangible progress against, the hepatitis C virus compared to non-chimpanzee research, and must be considered scientifically redundant, given the array of alternative methods of inquiry now available. The continuation of chimpanzee use in hepatitis C research adversely affects scientific progress, as well as chimpanzees and humans in need of treatment. Unfounded claims of its necessity should not discourage changes in public policy regarding the use of chimpanzees in US laboratories
An Assessment of the Use of Chimpanzees in Hepatitis C Research Past, Present and Future: 2. Alternative Replacement Methods
The use of chimpanzees in hepatitis C virus (HCV) research was examined in the report associated with this paper (1: Validity of the Chimpanzee Model), in which it was concluded that claims of past necessity of chimpanzee use were exaggerated, and that claims of current and future indispensability were unjustifiable. Furthermore, given the serious scientific and ethical issues surrounding chimpanzee experimentation, it was proposed that it must now be considered redundant — particularly in light of the demonstrable contribution of alternative methods to past and current scientific progress, and the future promise that these methods hold. This paper builds on this evidence, by examining the development of alternative approaches to the investigation of HCV, and by reviewing examples of how these methods have contributed, and are continuing to contribute substantially, to progress in this field. It augments the argument against chimpanzee use by demonstrating the comprehensive nature of these methods and the valuable data they deliver. The entire life-cycle of HCV can now be investigated in a human (and much more relevant) context, without recourse to chimpanzee use. This also includes the testing of new therapies and vaccines. Consequently, there is no sound argument against the changes in public policy that propose a move away from chimpanzee use in US laboratories
Temporal trends of infective endocarditis in North America from 2000 to 2017 – a systematic review
Objectives
To examine temporal changes of infective endocarditis (IE) incidence and epidemiology in North America.
Patients and Methods
A systematic review was conducted at Mayo Clinic, Rochester. Ovid EBM Reviewsâ„¢, Ovid Embaseâ„¢, Ovid Medlineâ„¢, Scopusâ„¢, and Web of Scienceâ„¢ were searched for studies published between January 1, 2000 and May 31, 2020. Four referees independently reviewed all studies, and those that reported a population-based incidence of IE in patients aged 18 years and older in North America were included.
Results
Of 8,588 articles screened, 14 were included. Overall, IE incidence remained largely unchanged throughout the study period, except for two studies that demonstrated a rise in incidence after 2014. Five studies reported temporal trends of injection drug use (IDU) prevalence among IE patients with a notable increase in prevalence observed. Staphylococcus aureus was the most common pathogen in 7 of 9 studies that included microbiologic findings. In-patient mortality ranged from 3.7-14.4%, while the percentage of patients who underwent surgery ranged from 6.4-16.0%.
Conclusion
Overall incidence of IE has remained stable among the 14 population-based investigations in North America identified in our systematic review. Standardization of study design for future population-based investigations have been highlighted for use in subsequent systematic reviews of IE
Understanding preventive behaviors among mid-Western African-American men: a pilot qualitative study of prostate screening
http://dx.doi.org/10.1016/j.jomh.2011.03.00
Semidiscrete biomass dynamic modeling: an improved approach for assessing fish stock responses to pulsed harvest events
A General Algorithm for Calculating Jet Cross Sections in NLO QCD
We present a new general algorithm for calculating arbitrary jet cross
sections in arbitrary scattering processes to next-to-leading accuracy in
perturbative QCD. The algorithm is based on the subtraction method. The key
ingredients are new factorization formulae, called dipole formulae, which
implement in a Lorentz covariant way both the usual soft and collinear
approximations, smoothly interpolating the two. The corresponding dipole phase
space obeys exact factorization, so that the dipole contributions to the cross
section can be exactly integrated analytically over the whole of phase space.
We obtain explicit analytic results for any jet observable in any scattering or
fragmentation process in lepton, lepton-hadron or hadron-hadron collisions. All
the analytical formulae necessary to construct a numerical program for
next-to-leading order QCD calculations are provided. The algorithm is
straightforwardly implementable in general purpose Monte Carlo programs.Comment: Resubmitted version corrects an error in the definitions of the
Lorentz boosts used in sections 5.5 and 5.6. No other results are affected.
120 pages, 4 figures. This paper can also be obtained from
http://surya11.cern.ch/users/seymour/pubs/nlo.htm
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