5,122 research outputs found
The Painful Long Head of the Biceps Brachii: Nonoperative Treatment Approaches
Pain associated with the long head of the biceps (LHB) brachii seems to be increasingly recognized in the past 4 to 5 years. The LHB has long been considered a troublesome pain generator in the shoulder. Abnormality involving the LHB brachii has long been an area of debate, with Codman in 1934 even questioning the specificity of the diagnosis of biceps tendinitis. Biceps tendon abnormality is often associated with rotator cuff impingement. Shoulder pain originating from the biceps tendon can be debilitating, causing a severe decrease in shoulder function. As a result of the frequent clinical presentation of biceps pain, there is currently a great deal of interest regarding the diagnosis, treatment, and prevention of biceps abnormality. This article describes a classification system of LHB pain and discusses nonoperative treatment concepts and techniques for the painful LHB
On the possibility of q-scaling in high energy production processes
It has been noticed recently that transverse momenta (p_T) distributions
observed in high energy production processes exhibit remarkably universal
scaling behaviour. This is the case when a suitable variable replaces the usual
p_T. On the other hand, it is also widely known that transverse momentum
distributions in general follow a power-like Tsallis distribution, rather than
an exponential Boltzmann-Gibbs, with a (generally energy dependent)
nonextensivity parameter q. Here we show that it is possible to choose a
suitable variable such that all the data can be fitted by the same Tsallis
distribution (with the same, energy independent value of the q-parameter). Thus
they exhibit q-scaling.Comment: Final version, accepted by J.Phys.
Duality and spatial inhomogeneity
Within the framework on non-extensive thermostatistics we revisit the
recently advanced q-duality concept. We focus our attention here on a modified
q-entropic measure of the spatial inhomogeneity for binary patterns. At a fixed
length-scale this measure exhibits a generalised duality that links appropriate
pairs of q and q' values. The simplest q q' invariant function, without any
free parameters, is deduced here. Within an adequate interval q < qo < q', in
which the function reaches its maximum value at qo, this invariant function
accurately approximates the investigated q-measure, nitidly evidencing the
duality phenomenon. In the close vicinity of qo, the approximate meaningful
relation q + q' = 2qo holds.Comment: Contribution to International School and Conference on "Non Extensive
Thermodynamics and physical applications", Villasimius-Capo Boi (Cagliari),
Italy, 23-30 May 2001, 6 pages, 2 figures, replaced with published versio
Systematic analysis of pT -distributions in p + p collisions
A systematic analysis of transverse momentum distribution of hadrons produced
in ultra-relativistic p + p collisions is presented. We investigate the
effective temperature and the entropic parameter from the non-extensive
thermodynamic theory of strong interaction. We conclude that the existence of a
limiting effective temperature and of a limiting entropic parameter is in
accordance with experimental data.Comment: 9 pages, 5 figure
Consequences of temperature fluctuations in observables measured in high energy collisions
We review the consequences of intrinsic, nonstatistical temperature
fluctuations as seen in observables measured in high energy collisions. We do
this from the point of view of nonextensive statistics and Tsallis
distributions. Particular attention is paid to multiplicity fluctuations as a
first consequence of temperature fluctuations, to the equivalence of
temperature and volume fluctuations, to the generalized thermodynamic
fluctuations relations allowing us to compare fluctuations observed in
different parts of phase space, and to the problem of the relation between
Tsallis entropy and Tsallis distributions. We also discuss the possible
influence of conservation laws on these distributions and provide some examples
of how one can get them without considering temperature fluctuations.Comment: Revised version of the invited contribution to The European Physical
Journal A (Hadrons and Nuclei) topical issue about 'Relativistic Hydro- and
Thermodynamics in Nuclear Physics' guest eds. Tamas S. Biro, Gergely G.
Barnafoldi and Peter Va
The hypocretin/orexin antagonist almorexant promotes sleep without impairment of performance in rats.
The hypocretin receptor (HcrtR) antagonist almorexant (ALM) has potent hypnotic actions but little is known about neurocognitive performance in the presence of ALM. HcrtR antagonists are hypothesized to induce sleep by disfacilitation of wake-promoting systems whereas GABAA receptor modulators such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. To test the hypothesis that less functional impairment results from HcrtR antagonist-induced sleep, we evaluated the performance of rats in the Morris Water Maze in the presence of ALM vs. ZOL. Performance in spatial reference memory (SRM) and spatial working memory (SWM) tasks were assessed during the dark period after equipotent sleep-promoting doses (100 mg/kg, po) following undisturbed and sleep deprivation (SD) conditions. ALM-treated rats were indistinguishable from vehicle (VEH)-treated rats for all SRM performance measures (distance traveled, latency to enter, time within, and number of entries into, the target quadrant) after both the undisturbed and 6 h SD conditions. In contrast, rats administered ZOL showed impairments in all parameters measured compared to VEH or ALM in the undisturbed conditions. Following SD, ZOL-treated rats also showed impairments in all measures. ALM-treated rats were similar to VEH-treated rats for all SWM measures (velocity, time to locate the platform and success rate at finding the platform within 60 s) after both the undisturbed and SD conditions. In contrast, ZOL-treated rats showed impairments in velocity and in the time to locate the platform. Importantly, ZOL rats only completed the task 23-50% of the time while ALM and VEH rats completed the task 79-100% of the time. Thus, following equipotent sleep-promoting doses, ZOL impaired rats in both memory tasks while ALM rats performed at levels comparable to VEH rats. These results are consistent with the hypothesis that less impairment results from HcrtR antagonism than from GABAA-induced inhibition
On the influence of statistics on the determination of the mean value of the depth of shower maximum for ultra high energy cosmic ray showers
The chemical composition of ultra high energy cosmic rays is still uncertain.
The latest results obtained by the Pierre Auger Observatory and the HiRes
Collaboration, concerning the measurement of the mean value and the
fluctuations of the atmospheric depth at which the showers reach the maximum
development, Xmax, are inconsistent. From comparison with air shower
simulations it can be seen that, while the Auger data may be interpreted as a
gradual transition to heavy nuclei for energies larger than ~ 2-3x10^18 eV, the
HiRes data are consistent with a composition dominated by protons. In Ref. [1]
it is suggested that a possible explanation of the observed deviation of the
mean value of Xmax from the proton expectation, observed by Auger, could
originate in a statistical bias arising from the approximated exponential shape
of the Xmax distribution, combined with the decrease of the number of events as
a function of primary energy. In this paper we consider a better description of
the Xmax distribution and show that the possible bias in the Auger data is at
least one order of magnitude smaller than the one obtained when assuming an
exponential distribution. Therefore, we conclude that the deviation of the
Auger data from the proton expectation is unlikely explained by such
statistical effect.Comment: To be published in Journal of Physics G: Nuclear and Particle Physic
On the chemical composition of cosmic rays of highest energy
We present arguments aiming at reconciling apparently contradictory results
concerning the chemical composition of cosmic rays of highest energy, coming
recently from the Auger and HiRes collaborations. In particular, we argue that
the energy dependence of the mean value and root mean square fluctuation of
shower maxima distributions observed by the Auger experiment are not
necessarily caused by the change of nuclear composition of primary cosmic rays.
They could also be caused by the change of distribution of the first
interaction point in the cascade. A new observable, in which this influence is
strongly suppressed, is proposed and tested.Comment: Version accepted by J.Phys. G (2011
Propagation of strangelets in the Earth's atmosphere
A new model for the description of the behaviour of strangelets in the
Earth's atmosphere is presented. Strangelet fission induced by collision with
air nuclei is included. It is shown that strangelets with certain parameters of
initial mass and energy may reach depths near sea level, which can be examined
by ground-based experiments.Comment: 10 pages, 6 figure
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