1,015 research outputs found
Extreme ameloblastoma of the mandible with hypoproteinemia: a case report and review of clinicopathological features
Ameloblastoma is a tumor of odontogenic epithelium. It has an intermediate malignant potential, thus positioning it
in a gray zone between benign and malignant neoplasms. Invasive ameloblastomas of excessive size are rarely confronted. Although these ameloblastomas are benign, they are life threatening. Many have eventuated in death due
to airway obstruction, starvation from restriction of feeding, and complications of hypoproteinemia. These tumors
cause significant expansion of skin and lips [tissue expanders]. Due to its metabolic demands, a tumor of enormous
size will have numerous feeding vessels. Patients with extreme ameloblastomas are usually from rural areas of
developing countries who delay the treatment due to fear of surgery. We present a case of extreme ameloblastoma
in a 35 year old female which was a consequence of patient negligence. The tumor reached an enormous size over
10 years causing gross facial deformities and posed considerable problems in management
Right-handed Sneutrinos as Nonthermal Dark Matter
When the minimal supersymmetric standard model is augmented by three
right-handed neutrino superfields, one generically predicts that the neutrinos
acquire Majorana masses. We postulate that all supersymmetry (SUSY) breaking
masses as well as the Majorana masses of the right-handed neutrinos are around
the electroweak scale and, motivated by the smallness of neutrino masses,
assume that the lightest supersymmetric particle (LSP) is an almost-pure
right-handed sneutrino. We discuss the conditions under which this LSP is a
successful dark matter candidate. In general, such an LSP has to be nonthermal
in order not to overclose the universe, and we find the conditions under which
this is indeed the case by comparing the Hubble expansion rate with the rates
of the relevant thermalizing processes, including self-annihilation and
co-annihilation with other SUSY and standard model particles.Comment: 17 pages v.2: References adde
Sfermion masses in the supersymmetric economical 3-3-1 model
Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model
are studied. By lepton number conservation, the exotic squarks and
superpartners of ordinary quarks are decoupled. Due to the fact that in the
3-3-1 models, one generation of quarks behaves differently from other two, by
R-parity conservation, the mass mixing matrix of the squarks in this model are
smaller than that in the Minimal Supersymmetric Standard Model (MSSM). Assuming
substantial mixing in pairs of highest flavours, we are able to get mass
spectrum and eigenstates of all the sfermions. In the effective approximation,
the slepton mass splittings in the first two generations, are consistent with
those in the MSSM, namely: m^2_{\tilde{l}_L} - m^2_{\tilde{\nu}_{l L}} =
m_W^2 \cos 2\ga . In addition, within the above effective limit,
there exists degeneracy among sneutrinos in each multiplet:
. In contradiction to the
MSSM, the squark mass splittings are different for each generation and not to
be m_W^2 \cos 2\ga.Comment: 34 pages, 2 figures, Revised version in which D-term and F-term
contributions are slightly change
SmartEx: a case study on user profiling and adaptation in exhibition booths
An investigation into user profiling and adaptation with exhibition booth as a case study is reported. First a review of the field of exhibitions and trade fairs and a summary introduction to adaptation and profiling are given. We then introduce three criteria for the evaluation of exhibition booth: effectiveness, efficiency and affect. Effectiveness is related the amount of information collected, efficiency is a measurement of the time taken to collect the information, and affect is the perception of the experience and the mood booth visitors have during and after their visit. We have selected these criteria to assess adaptive and profiled exhibition booths, we call smart exhibition (SmartEx). The assessment is performed with an experiment with three test conditions (non-profiled/non adaptive, profiled/non-adaptive and profiled adaptive presentations). Results of the experiment are presented along discussion. While there is significant improvements of effectiveness and efficiency between the two-first test conditions, the improvement is not significant for the last test condition, for reasons explained. As for the affect, the results show that it has an under-estimated importance in people minds and that it should be addressed more carefully
Top Partner Discovery in the channel at the LHC
In this paper we study the discovery potential of the LHC run II for heavy
vector-like top quarks in the decay channel to a top and a boson. Despite
the usually smaller branching ratio compared to charged-current decays, this
channel is rather clean and allows for a complete mass reconstruction of the
heavy top. The latter is achieved in the leptonic decay channel of the
boson and in the fully hadronic top channel using boosted jet and jet
substructure techniques. To be as model-independent as possible, a simplified
model approach with only two free parameters has been applied. The results are
presented in terms of parameter space regions for evidence or
discovery for such new states in that channel.Comment: 24 pages, 8 figures, version 2 updated to JHEP 01 (2015) 08
Collider Signature of Bulk Neutrinos in Large Extra Dimensions
We consider the collider signature of right-handed neutrinos propagating in
(large) extra dimensions, and interacting with Standard Model fields
only through a Yukawa coupling to the left-handed neutrino and the Higgs boson.
These theories are attractive as they can explain the smallness of the neutrino
mass, as has already been shown. We show that if is bigger than two,
it can result in an enhancement in the production rate of the Higgs boson,
decaying either invisibly or to a anti- quark pair, associated with an
isolated high charged lepton and missing transverse energy at future
hadron colliders, such as the LHC. The enhancement is due to the large number
of Kaluza-Klein neutrinos produced in the final state. The observation of the
signal event would provide an opportunity to distinguish between the normal and
inverted neutrino mass hierarchies, and to determine the absolute scale of
neutrino masses by measuring the asymmetry of the observed event numbers in the
electron and muon channels.Comment: 31 pages, 13 figures. v2: Added discussion on PDF uncertainties,
added reference
System reliability assessment with nonlinear finite element analysis
System reliability concepts are applicable when the failure of the entire structure is of interest. For such general structural problems, the overall performance can often be predicted only by a nonlinear finite element technique. The development of a practical method to couple nonlinear finite element analysis with probability concepts to estimate the system reliability is the objective of this work;A method named Response Failure Surface Method is developed and illustrated for the case of plane trusses. The limit state of the structure is expressed in terms of the nodal displacements to accommodate either ultimate or serviceability conditions. The response failure surface is an approximation to the actual failure surface with several hyper-planes. The limit state value and its gradients with respect to the random variables are determined by a nonlinear finite element analysis. The gradient analysis is done in conjunction with the structural analysis by differentiating the equilibrium equations. The hyper-plane approximation to the actual failure surface replaces the nonlinear finite element analysis in a Monte Carlo procedure to evaluate the system reliability. In addition, the gradient analysis is incorporated into the Advanced First Order Second Moment method algorithm. An improvement in the probabilities of failure from the response failure surface method over the Advanced First Order Second Moment method is shown by comparing each with the exact limit state method in several examples. An inherent advantage of the response failure surface method is the capacity to account for the nonlinearity of the failure surface, the actual probability density function of the random variables, and the presence of several failure modes
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