2,848 research outputs found
Narrow Technihadron Production at the First Muon Collider
In modern technicolor models, there exist very narrow spin-zero and spin-one
neutral technihadrons---, and ---with masses of a
few 100 GeV. The large coupling of to , the direct
coupling of and to the photon and , and the superb
energy resolution of the First Muon Collider may make it possible to resolve
these technihadrons and produce them at extraordinarily large rates.Comment: 11 pages, latex, including 2 postscript figure
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'Can you be a doctor, even if you faint?' The tacit lessons of cadaveric dissection
Background: The undergraduate Medicine course at the University of Cambridge has included cadaveric dissection as part of its anatomy teaching for over three centuries. In recent years, medical schools in the UK and the US have debated whether cadaveric dissection is a useful and efficient way of teaching anatomy. Existing research on this subject has focused narrowly on the knowledge-acquisition for medical students afforded through dissection, and thus we have broadened the scope of such considerations to include the emotional responses of medical students to the dissection process.
Subjects and methods: The basis for this paper is a phenomenological analysis of response data gathered from 56 first year medical students at the University of Cambridge through written questionnaires and discussion groups before and after their first experiences of cadaveric dissection.
Results: Our research suggests that there are in fact many more lessons taught and acquired through studying in the dissection room: they are tacit, emotional, experiential and dispositional.
Conclusions: When this wider picture of the value of dissection is considered, a much stronger case for the continued inclusion of cadaveric dissection in the medical curriculum can be made, as it is a valuable and unique educational experience
Two-way FSI modelling of blood flow through CCA accounting on-line medical diagnostics in hypertension
Flow parameters can induce pathological changes in the arteries. We propose a
method to asses those parameters using a 3D computer model of the flow in the Common
Carotid Artery. Input data was acquired using an automatic 2D ultrasound wall tracking
system. This data has been used to generate a 3D geometry of the artery. The diameter and wall
thickness have been assessed individually for every patient, but the artery has been taken as a
75mm straight tube. The Young’s modulus for the arterial walls was calculated using the pulse
pressure, diastolic (minimal) diameter and wall thickness (IMT). Blood flow was derived from
the pressure waveform using a 2-parameter Windkessel model. The blood is assumed to be
non-Newtonian. The computational models were generated and calculated using commercial
code. The coupling method required the use of Arbitrary Lagrangian-Euler formulation to
solve Navier-Stokes and Navier-Lamè equations in a moving domain. The calculations showed
that the distention of the walls in the model is not significantly different from the
measurements. Results from the model have been used to locate additional risk factors, such as
wall shear stress or circumferential stress, that may predict adverse hypertension
complications
Optimal use of Information for Measuring in Lepton+jets Events
We present a novel approach that is being developed at DZero for extracting
information from data through a direct comparison of all measured variables in
an event with a matrix element that describes the entire production process.
The method is exemplified in the extraction of the mass of the top quark in
top-antitop events in the lepton+jets final state. Monte Carlo studies suggest
that an improvement of about a factor of two in statistical uncertainty on the
mass of the top quark can be achieved relative to previously published work for
the same channel. Preliminary results from the re-analysis provide a reduction
in the statistical uncertainty of almost a factor of 1.6, corresponding to an
effective factor of 2.4 increase in the size of the data sample.Comment: presented at HCP200
Physics Beyond the Standard Model
I briefly summarize the prospects for extending our understanding of physics
beyond the standard model within the next five years.Comment: 9 pages, 2 figures, LaTeX. Presented at the 1999 UK Phenomenology
Workshop, Durham, September 1999. To be published in Journal of Physics
Multigene analyses resolve early diverging lineages in the Rhodymeniophycidae (Florideophyceae, Rhodophyta).
Multigene phylogenetic analyses were directed at resolving the earliest divergences in the red algal subclass Rhodymeniophycidae. The inclusion of key taxa (new to science and/or previously lacking molecular data), additional sequence data (SSU, LSU, EF2, rbcL, COI-5P), and phylogenetic analyses removing the most variable sites (site stripping) have provided resolution for the first time at these deep nodes. The earliest diverging lineage within the subclass was the enigmatic Catenellopsis oligarthra from New Zealand (Catenellopsidaceae), which is here placed in the Catenellopsidales ord. nov. In our analyses Atractophora hypnoides was not allied with the other included Bonnemaisoniales, but resolved as sister to the Peyssonneliales, and is here assigned to Atractophoraceae fam. nov. in the Atractophorales ord. nov. Inclusion of Acrothesaurum gemellifilum gen. et sp. nov. from Tasmania has greatly improved our understanding of the Acrosymphytales, to which we assign three families, the Acrosymphytaceae, Acrothesauraceae fam. nov. and Schimmelmanniaceae fam. nov. This article is protected by copyright. All rights reserved
World radiocommunication conference 12 : implications for the spectrum eco-system
Spectrum allocation is once more a key issue facing the global telecommunications industry. Largely overlooked in current debates, however, is the World Radiocommunication Conference (WRC). Decisions taken by WRC shape the future roadmap of the telecommunications industry, not least because it has the ability to shape the global spectrum allocation framework. In the debates of WRC-12 it is possible to identify three main issues: enhancement of the international spectrum regulatory framework, regulatory measures required to introduce Cognitive Radio Systems (CRS) technologies; and, additional spectrum allocation to mobile service. WRC-12 eventually decided not to change the current international radio regulations with regard to the first two issues and agreed to the third issue. The main implications of WRC-12 on the spectrum ecosystem are that most of actors are not in support of the concept of spectrum flexibility associated with trading and that the concept of spectrum open access is not under consideration. This is explained by the observation that spectrum trading and spectrum commons weaken state control over spectrum and challenge the main principles and norms of the international spectrum management regime. In addition, the mobile allocation issue has shown the lack of conformity with the main rules of the regime: regional spectrum allocation in the International Telecommunication Union (ITU) three regions, and the resistance to the slow decision making procedures. In conclusion, while the rules and decision-making procedures of the international spectrum management regime were challenged in the WRC-12, the main principles and norms are still accepted by the majority of countries
Direct Measurement of the Top Quark Mass at D0
We determine the top quark mass m_t using t-tbar pairs produced in the D0
detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the
Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar
W^- final states with one W boson decaying to q-qbar and the other to e-nu or
mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +-
5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in
which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +-
4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed
top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst)
GeV/C^2, consistent with the above result. Studies of kinematic distributions
of the top quark candidates are also presented.Comment: 43 pages, 53 figures, 33 tables. RevTeX. Submitted to Phys. Rev.
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