2,237 research outputs found
The generic character table of a Sylow -subgroup of a finite Chevalley group of type
Let be a Sylow -subgroup of the finite Chevalley group of type
over the field of elements, where is a power of a prime . We
describe a construction of the generic character table of
Quantum Algorithm for the Collision Problem
In this note, we give a quantum algorithm that finds collisions in arbitrary
r-to-one functions after only O((N/r)^(1/3)) expected evaluations of the
function. Assuming the function is given by a black box, this is more efficient
than the best possible classical algorithm, even allowing probabilism. We also
give a similar algorithm for finding claws in pairs of functions. Furthermore,
we exhibit a space-time tradeoff for our technique. Our approach uses Grover's
quantum searching algorithm in a novel way.Comment: 8 pages, LaTeX2
A systems thinking approach to collaborations for capacity building and sustainability in engineering education
Abstract: Please refer to full text to view abstract
Diagnosing Musculoskeletal Tumours
In 1993 we became aware of a worrying increase in apparent errors in the histopathological diagnosis of musculoskeletal
tumours in our Unit. As a result all cases seen over the past 8 years were reviewed by an independent panel. Of the 1996
cases reviewed there was an error in 87. In 54 cases (2.7%) this had led to some significant change in the active management
of the patient. The main areas where errors arose were in those very cases where clinical and radiological features were not
helpful in confirming or refuting the diagnosis. The incidence of errors rose with the passage of time, possibly related to a
deterioration in the pathologist’s health. The error rate in diagnosing bone tumours in previously published series ranges
from 9 to 40%. To ensure as accurate a rate of diagnosis as possible multidisciplinary working and regular audit are essential
Wound Complications Following Resection of Adductor Compartment Tumours
Purpose Limb salvage surgery of soft tissue sarcomas is associated with both a risk of local recurrence and wound complications.
Although the lower limb appears to be at greater risk of wound-related morbidity, few studies separate anatomical
compartments. We believe that the adductor compartment of the thigh has a particularly high rate of complications and so
performed a retrospective analysis of all soft tissue sarcomas arising in this region undergoing limb salvage
Preliminary evidence of increased striatal dopamine in a nonhuman primate model of maternal immune activation.
Women exposed to a variety of viral and bacterial infections during pregnancy have an increased risk of giving birth to a child with autism, schizophrenia or other neurodevelopmental disorders. Preclinical maternal immune activation (MIA) models are powerful translational tools to investigate mechanisms underlying epidemiological links between infection during pregnancy and offspring neurodevelopmental disorders. Our previous studies documenting the emergence of aberrant behavior in rhesus monkey offspring born to MIA-treated dams extends the rodent MIA model into a species more closely related to humans. Here we present novel neuroimaging data from these animals to further explore the translational potential of the nonhuman primate MIA model. Nine male MIA-treated offspring and 4 controls from our original cohort underwent in vivo positron emission tomography (PET) scanning at approximately 3.5-years of age using [18F] fluoro-l-m-tyrosine (FMT) to measure presynaptic dopamine levels in the striatum, which are consistently elevated in individuals with schizophrenia. Analysis of [18F]FMT signal in the striatum of these nonhuman primates showed that MIA animals had significantly higher [18F]FMT index of influx compared to control animals. In spite of the modest sample size, this group difference reflects a large effect size (Cohen's d = 0.998). Nonhuman primates born to MIA-treated dams exhibited increased striatal dopamine in late adolescence-a hallmark molecular biomarker of schizophrenia. These results validate the MIA model in a species more closely related to humans and open up new avenues for understanding the neurodevelopmental biology of schizophrenia and other neurodevelopmental disorders associated with prenatal immune challenge
Growth in the Lower Limb Following Chemotherapy for a Malignant Primary Bone Tumour: A Straight-Line Graph
Purpose. The aim of this paper was to assess the growth in the unaffected lower limb of children who had received
chemotherapy for a malignant primary bone tumour around the knee
Tumour Transfer to Bone Graft Donor Site: A Case Report and Review of the Literature of the Mechanism of Seeding
Purpose. Transmission of malignant tumour cells to a bone graft donor site
is a rare complication of bone grafting.We report a case of seeding of malignant fibrous
histiocytoma from the femur to a pelvic bone graft donor site
A spacetime characterization of the Kerr metric
We obtain a characterization of the Kerr metric among stationary,
asymptotically flat, vacuum spacetimes, which extends the characterization in
terms of the Simon tensor (defined only in the manifold of trajectories) to the
whole spacetime. More precisely, we define a three index tensor on any
spacetime with a Killing field, which vanishes identically for Kerr and which
coincides in the strictly stationary region with the Simon tensor when
projected down into the manifold of trajectories. We prove that a stationary
asymptotically flat vacuum spacetime with vanishing spacetime Simon tensor is
locally isometric to Kerr. A geometrical interpretation of this
characterization in terms of the Weyl tensor is also given. Namely, a
stationary, asymptotically flat vacuum spacetime such that each principal null
direction of the Killing form is a repeated principal null direction of the
Weyl tensor is locally isometric to Kerr.Comment: 23 pages, No figures, LaTeX, to appear in Classical and Quantum
Gravit
The Two-Stage Ipsilateral Fibular Transfer for Tibial Defect Following Tumour Excision
Method. We performed a two-stage vascularized ipsilateral fibular
graft transfer for segmental tibial defect following excision of malignant bone tumours
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