13,802 research outputs found
Ground-state energy shift of n pions and m kaons in a finite volume
The ground state energy of a collection of n pions and m kaons with short
range interactions is calculated for a volume with finite spatial extent L and
periodic boundary conditions. This calculation is accomplished to order L^-6 in
the large volume expansion. With this result one can extract the various two-
and three-body interactions between pions and kaons from lattice QCD data
Ground-state energy shift of n pions and m kaons in a finite volume
The ground state energy of a collection of n pions and m kaons with short
range interactions is calculated for a volume with finite spatial extent L and
periodic boundary conditions. This calculation is accomplished to order L^-6 in
the large volume expansion. With this result one can extract the various two-
and three-body interactions between pions and kaons from lattice QCD data
Effect of Sensory Attenuation on Cortical Movement-Related Oscillations
This study examined the impact of induced sensory deficits on cortical, movement-related oscillations measured using electroencephalography (EEG). We hypothesized that EEG patterns in healthy subjects with induced sensory reduction would be comparable to EEG found after chronic loss of sensory feedback. EEG signals from 64 scalp locations were measured from 10 healthy subjects. Participants dorsiflexed their ankle after prolonged vibration of the tibialis anterior (TA). Beta band time frequency decompositions were calculated using wavelets and compared across conditions. Changes in patterns of movement-related brain activity were observed following attenuation of sensory feedback. A significant decrease in beta power of event-related synchronization was associated with simple ankle dorsiflexion after prolonged vibration of the TA. Attenuation of sensory feedback in young, healthy subjects led to a corresponding decrease in beta band synchronization. This temporary change in beta oscillations suggests that these modulations are a mechanism for sensorimotor integration. The loss of sensory feedback found in spinal cord injury patients contributes to changes in EEG signals underlying motor commands. Similar alterations in cortical signals in healthy subjects with reduced sensory feedback implies these changes reflect normal sensorimotor integration after reduced sensory input rather than brain plasticity
Carnage Interrupted: An Analysis of Fifteen Terrorist Plots against Public Surface Transportation, Research Report 11-20
This report examines 13 terrorist plots against public surface transportation that were uncovered and foiled by authorities between 1997 and 2010 and two failed attempts to carry out attacks. Certainly, this is not the total universe of foiled or failed terrorist plots in these years, but they were selected on the basis of what is known about them and the accessibility of information. The report focuses on terrorist plots in the West. Seven of the 15 plots took place in the United States, and four occurred in the United Kingdom. These two countries figure prominently as targets of terrorism, and in addition, American and British officials have dealt with terrorist plots through publicized arrests and trials, which provide additional information. Although motive was not a criterion in the selection of the plots, all but one involve individuals or groups inspired by al Qaeda’s ideology of violent global jihad against the West. The exception is the 1997 Flatbush plot, in which two terrorists, both of whom had connections with Hamas, angered by events in Palestine, simply wanted to kill as many Jews as possible to express their opposition to U.S. support for Israel. Other sources suggest that the Flatbush plotters wanted to force the release of jailed Islamist terrorists in the United States, including Ramzi Yousef, who participated in the 1993 World Trade Center bombing, and Sheik Omar Abdul-Rahman, who was convicted for his involvement in a plot to carry out additional bombings in New York
Scaling of Magneto-Quantum-Radiative Hydrodynamic Equations: From Laser-produced Plasmas to Astrophysics
We introduce here the equations of magneto-quantum-radiative hydrodynamics.
By rewriting them in a dimensionless form, we obtain a set of parameters that
describe scale-dependent ratios of all the characteristic hydrodynamic
quantities. We discuss how these dimensionless parameters relate to the scaling
between astrophysical observations and laboratory experiments.Comment: 12 page
Tuberculosis in Malta and the school BCG vaccination programme
Background: Malta has one of the lowest incidence rates of tuberculosis in Europe and a comprehensive free-of-charge health care system. Objective: To investigate whether Malta satisfies the criteria recommended by the International Union Against Tuberculosis and Lung Disease (IUATLD) in order to consider the discontinuation of the present school BCG vaccination programme. Method: Review of World Health Organization (WHO), and IUATLD guidelines for BCG use and discontinuation. Examination of surveillance data pertaining to tuberculosis in Malta, for the years 1979 to 2008. Findings: Malta has a long-standing, well-developed surveillance, treatment and follow-up programme for tuberculosis. The average annual notification rate of smear positive pulmonary tuberculosis was about 2 per 100,000 person-years since 1990. This is well below rates recommended by the IUATLD for the discontinuation of routine BCG vaccination programs. Conclusion: Malta satisfies established international criteria for discontinuation of the school BCG vaccination programme and therefore the programme should be reconsidered.peer-reviewe
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