1,939 research outputs found
Indication on the universal hadron substructure - constituent quarks
The universality of single-spin asymmetry on inclusive pi-meson production is
discussed. This universality can be related to the hadron substructure -
constituent quarks.Comment: 3 pages, 3 figures, references adde
Rapid tranquillisation for agitated patients in emergency psychiatric rooms: a randomised trial of midazolam versus haloperidol plus promethazine
OBJECTIVE: To compare two widely used drug treatments for people with aggression or agitation due to mental illness.
DESIGN: Pragmatic, randomised clinical trial.
SETTING: Three psychiatric emergency rooms in Rio de Janeiro, Brazil.
SUBJECTS: 301 aggressive or agitated people.
INTERVENTIONS: Open treatment with intramuscular midazolam or intramuscular haloperidol plus promethazine.
MAIN OUTCOME MEASURES: Patients tranquil or sedated at 20 minutes. Secondary outcomes: patients tranquil or asleep by 40, 60, and 120 minutes; restrained or given extra drugs within 2 hours; severe adverse events; another episode of agitation or aggression; needing extra visits from doctor during first 24 hours; overall antipsychotic load in first 24 hours; and not discharged by two weeks
Swiss medical centres vary significantly when it comes to outcomes of neonates with a very low gestational age.
AIM: This study quantified the impact of perinatal predictors and medical centre on the outcome of very low-gestational-age neonates (VLGANs) born at <32 completed weeks in Switzerland.
METHODS: Using prospectively collected data from a 10-year cohort of VLGANs, we developed logistic regression models for three different time points: delivery, NICU admission and seven days of age. The data predicted survival to discharge without severe neonatal morbidity, such as major brain injury, moderate or severe bronchopulmonary dysplasia, retinopathy of prematurity (≥stage three) or necrotising enterocolitis (≥stage three).
RESULTS: From 2002 to 2011, 6892 VLGANs were identified: 5854 (85%) of the live-born infants survived and 84% of the survivors did not have severe neonatal complications. Predictors for adverse outcome at delivery and on NICU admission were low gestational age, low birthweight, male sex, multiple birth, birth defects and lack of antenatal corticosteroids. Proven sepsis was an additional risk factor on day seven of life. The medical centre remained a statistically significant factor at all three time points after adjusting for perinatal predictors.
CONCLUSION: After adjusting for perinatal factors, the survival of Swiss VLGANs without severe neonatal morbidity was strongly influenced by the medical centre that treated them
Strange form factors of the proton: a new analysis of the neutrino (antineutrino) data of the BNL-734 experiment
We consider ratios of elastic neutrino(antineutrino)-proton cross sections
measured by the Brookhaven BNL-734 experiment and use them to obtain the
neutral current (NC) over charged current (CC) neutrino-antineutrino asymmetry.
We discuss the sensitivity of these ratios and of the asymmetry to the
electric, magnetic and axial strange form factors of the nucleon and to the
axial cutoff mass M_A. We show that the effects of the nuclear structure and
interactions on the asymmetry and, in general, on ratios of cross sections are
negligible. We find some restrictions on the possible values of the parameters
characterizing the strange form factors. We show that a precise measurement of
the neutrino-antineutrino asymmetry would allow the extraction of the axial and
vector magnetic strange form factors in a model independent way. The
neutrino-antineutrino asymmetry turns out to be almost independent on the
electric strange form factor and on the axial cutoff mass.Comment: 12 page
Spontaneous breaking of Lorentz invariance, black holes and perpetuum mobile of the 2nd kind
We study the effect of spontaneous breaking of Lorentz invariance on black
hole thermodynamics. We consider a scenario where Lorentz symmetry breaking
manifests itself by the difference of maximal velocities attainable by
particles of different species in a preferred reference frame. The Lorentz
breaking sector is represented by the ghost condensate. We find that the
notions of black hole entropy and temperature loose their universal meaning. In
particular, the standard derivation of the Hawking radiation yields that a
black hole does emit thermal radiation in any given particle species, but with
temperature depending on the maximal attainable velocity of this species. We
demonstrate that this property implies violation of the second law of
thermodynamics, and hence, allows construction of a perpetuum mobile of the 2nd
kind. We discuss possible interpretation of these results.Comment: 13 pages; references adde
Out of equilibrium: understanding cosmological evolution to lower-entropy states
Despite the importance of the Second Law of Thermodynamics, it is not
absolute. Statistical mechanics implies that, given sufficient time, systems
near equilibrium will spontaneously fluctuate into lower-entropy states,
locally reversing the thermodynamic arrow of time. We study the time
development of such fluctuations, especially the very large fluctuations
relevant to cosmology. Under fairly general assumptions, the most likely
history of a fluctuation out of equilibrium is simply the CPT conjugate of the
most likely way a system relaxes back to equilibrium. We use this idea to
elucidate the spacetime structure of various fluctuations in (stable and
metastable) de Sitter space and thermal anti-de Sitter space.Comment: 27 pages, 11 figure
Existence and conditional energetic stability of three-dimensional fully localised solitary gravity-capillary water waves
In this paper we show that the hydrodynamic problem for three-dimensional
water waves with strong surface-tension effects admits a fully localised
solitary wave which decays to the undisturbed state of the water in every
horizontal direction. The proof is based upon the classical variational
principle that a solitary wave of this type is a critical point of the energy
subject to the constraint that the momentum is fixed. We prove the existence of
a minimiser of the energy subject to the constraint that the momentum is fixed
and small. The existence of a small-amplitude solitary wave is thus assured,
and since the energy and momentum are both conserved quantities a standard
argument may be used to establish the stability of the set of minimisers as a
whole. `Stability' is however understood in a qualified sense due to the lack
of a global well-posedness theory for three-dimensional water waves.Comment: 83 pages, 1 figur
Gravitational Coupling and Dynamical Reduction of The Cosmological Constant
We introduce a dynamical model to reduce a large cosmological constant to a
sufficiently small value. The basic ingredient in this model is a distinction
which has been made between the two unit systems used in cosmology and particle
physics. We have used a conformal invariant gravitational model to define a
particular conformal frame in terms of large scale properties of the universe.
It is then argued that the contributions of mass scales in particle physics to
the vacuum energy density should be considered in a different conformal frame.
In this manner, a decaying mechanism is presented in which the conformal factor
appears as a dynamical field and plays a key role to relax a large effective
cosmological constant. Moreover, we argue that this model also provides a
possible explanation for the coincidence problem.Comment: To appear in GR
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