3,371 research outputs found
Bose-Einstein Correlations in Multihadron Events at LEP
Bose-Einstein correlations in pairs of identical particles were analyzed in
e+ e- multihadron annihilations at ~91.2 GeV at LEP. The first studies involved
identical charged pions and the emitting source size was determined. Then the
study of charged kaons suggested that the radius depends on the mass of the
emitted particles. Subsequenty the dependence of the source radius on the event
multiplicity was analyzed. The study of the correlations in neutral pions and
neutral kaons extended these concepts to neutral particles. The shape of the
source was analyzed in 3 dimensions and was found not to be spherically
symmetric. In recent studies at LEP the correlations were analyzed in intervals
of the average pair transverse momentum and of the pair rapidity to study the
correlations between the pion production points and their momenta
(position-momentum correlations). The latest e+ e- data are consistent with an
expanding source.Comment: 8 pages, 10 eps figures. Invited paper at the ``Ninth Workshop on Non
Perturbative QCD'', Institut d'Astrophysique de Paris, Paris, France, 4-8
June 200
The sentiment analysis of tweets as a new tool to measure public perception of male erectile and ejaculatory dysfunctions
Twitter is a social network based on "tweets," short messages of up to 280 characters. Social media has been investigated in health care research to ascertain positive or negative feelings associated with several conditions but never in sexual medicin
Tremor in motor neuron disease may be central rather than peripheral in origin
BACKGROUND AND PURPOSE:
Motor neuron disease (MND) refers to a spectrum of degenerative diseases affecting motor neurons. Recent clinical and post-mortem observations have revealed considerable variability in the phenotype. Rhythmic involuntary oscillations of the hands during action, resembling tremor, can occur in MND, but their pathophysiology has not yet been investigated.
METHODS:
A total of 120 consecutive patients with MND were screened for tremor. Twelve patients with action tremor and no other movement disorders were found. Ten took part in the study. Tremor was recorded bilaterally using surface electromyography (EMG) and triaxial accelerometer, with and without a variable weight load. Power spectra of rectified EMG and accelerometric signal were calculated. To investigate a possible cerebellar involvement, eyeblink classic conditioning was performed in five patients.
RESULTS:
Action tremor was present in about 10% of our population. All patients showed distal postural tremor of low amplitude and constant frequency, bilateral with a small degree of asymmetry. Two also showed simple kinetic tremor. A peak at the EMG and accelerometric recordings ranging from 4 to 12 Hz was found in all patients. Loading did not change peak frequency in either the electromyographic or accelerometric power spectra. Compared with healthy volunteers, patients had a smaller number of conditioned responses during eyeblink classic conditioning.
CONCLUSIONS:
Our data suggest that patients with MND can present with action tremor of a central origin, possibly due to a cerebellar dysfunction. This evidence supports the novel idea of MND as a multisystem neurodegenerative disease and that action tremor can be part of this condition
User study on 3D multitouch interaction (3DMi) and gaze on surface computing
On a multitouch table, user’s interactions with 3D virtual representations of real objects should be influenced by task and their perceived physical characteristics. This article explores the development and user study of an interactive 3D application that allows users to explore virtual heritage objects on a surface device. To-date, most multitouch has focused on 2D or 2.5D systems. A user-study is reported where we analyse their multimodal behaviour – specifically how they interact on a surface device with objects that have similar properties to physical versions and the users’ associated gaze patterns with touch. The study reveals that gaze characteristics are different according to their interaction intention in terms of position and duration of visual attention. We discovered that virtual objects afford the perception of haptic attributes ascribed to their equivalent physical objects, and that differences in the summary statistics of gaze showed consistent characteristics between people and differences between natural and task based activities. An awareness of user behaviours using natural gestures can inform the design of interactive 3D applications which complements the user’s model of past experience with physical objects and with GUI interaction
Immunotherapeutic targeting of membrane Hsp70-expressing tumors using recombinant human granzyme B
Background: We have previously reported that human recombinant granzyme B (grB) mediates apoptosis in membrane heat shock protein 70 (Hsp70)-positive tumor cells in a perforin-independent manner
Avaliação das condições de transporte, desembarque e ocorrência de quedas dos suínos na perspectiva do bem-estar animal.
bitstream/item/58071/1/CUsersPiazzonDocuments459.pdfProjeto n. 02.06.10.100-03
Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV
The effects of the final state interaction phenomenon known as colour
reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~
189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to
affect observables based on charged particles in hadronic decays of W+W-.
Measurements of inclusive charged particle multiplicities, and of their angular
distribution with respect to the four jet axes of the events, are used to test
models of colour reconnection. The data are found to exclude extreme scenarios
of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other
models, both with and without colour reconnection effects. In the context of
the SK-I model, the best agreement with data is obtained for a reconnection
probability of 37%. Assuming no colour reconnection, the charged particle
multiplicity in hadronically decaying W bosons is measured to be (nqqch) =
19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
Bose-Einstein Correlations of Three Charged Pions in Hadronic Z^0 Decays
Bose-Einstein Correlations (BEC) of three identical charged pions were
studied in 4 x 10^6 hadronic Z^0 decays recorded with the OPAL detector at LEP.
The genuine three-pion correlations, corrected for the Coulomb effect, were
separated from the known two-pion correlations by a new subtraction procedure.
A significant genuine three-pion BEC enhancement near threshold was observed
having an emitter source radius of r_3 = 0.580 +/- 0.004 (stat.) +/- 0.029
(syst.) fm and a strength of \lambda_3 = 0.504 +/- 0.010 (stat.) +/- 0.041
(syst.). The Coulomb correction was found to increase the \lambda_3 value by
\~9% and to reduce r_3 by ~6%. The measured \lambda_3 corresponds to a value of
0.707 +/- 0.014 (stat.) +/- 0.078 (syst.) when one takes into account the
three-pion sample purity. A relation between the two-pion and the three-pion
source parameters is discussed.Comment: 19 pages, LaTeX, 5 eps figures included, accepted by Eur. Phys. J.
W+W- production and triple gauge boson couplings at LEP energies up to 183 GeV
A study of W-pair production in e+e- annihilations at Lep2 is presented,
based on 877 W+W- candidates corresponding to an integrated luminosity of 57
pb-1 at sqrt(s) = 183 GeV. Assuming that the angular distributions of the
W-pair production and decay, as well as their branching fractions, are
described by the Standard Model, the W-pair production cross-section is
measured to be 15.43 +- 0.61 (stat.) +- 0.26 (syst.) pb. Assuming lepton
universality and combining with our results from lower centre-of-mass energies,
the W branching fraction to hadrons is determined to be 67.9 +- 1.2 (stat.) +-
0.5 (syst.)%. The number of W-pair candidates and the angular distributions for
each final state (qqlnu,qqqq,lnulnu) are used to determine the triple gauge
boson couplings. After combining these values with our results from lower
centre-of-mass energies we obtain D(kappa_g)=0.11+0.52-0.37,
D(g^z_1)=0.01+0.13-0.12 and lambda=-0.10+0.13-0.12, where the errors include
both statistical and systematic uncertainties and each coupling is determined
setting the other two couplings to the Standard Model value. The fraction of W
bosons produced with a longitudinal polarisation is measured to be
0.242+-0.091(stat.)+-0.023(syst.). All these measurements are consistent with
the Standard Model expectations.Comment: 48 pages, LaTeX, including 13 eps or ps figures, submitted to
European Physical Journal
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