766 research outputs found
Classical and Quantum Fluctuation Theorems for Heat Exchange
The statistics of heat exchange between two classical or quantum finite
systems initially prepared at different temperatures are shown to obey a
fluctuation theorem.Comment: 4 pages, 1 included figure, to appear in Phys Rev Let
Numerical Simulations of Torsional Alfv\'en Waves in Axisymmetric Solar Magnetic Flux Tubes
We investigate numerically Alfv\'en waves propagating along an axisymmetric
and non-isothermal solar flux tube embedded in the solar atmosphere. The tube
magnetic field is current-free and diverges with height, and the waves are
excited by a periodic driver along the tube magnetic field lines. The main
results are that the two wave variables, the velocity and magnetic field
perturbations in the azimuthal direction, behave differently as a result of
gradients of physical parameters along the tube. To explain these differences
in the wave behavior, the time evolution of the wave variables and the
resulting cutoff period for each wave variable are calculated, and used to
determine regions in the solar chromosphere where strong wave reflection may
occur.Comment: Submitted to Solar Physics (accepted
Gentisic Acid, Salicylic Acid, Total Phenolic Content and Cholinesterase Inhibitory Activities of Red Wines Made from Various Grape Varieties
Alzheimer’s disease is characterised by a decrease in acetylcholine (ACh) levels in the brain due to the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). As a result, disorders in cholinergic transmission are observed, leading to cognitive impairment. In this work, the inhibition of AChE and BChE activities by red wines made of various grape varieties was determined for the first time. There was no significant difference in the polyphenol content between the grape varieties; nevertheless, there were significant differences in the content of gentisic acid and salicylic acid, and in the inhibition of AChE and BChE between the wine samples. A statistically significant correlation between AChE inhibitory activity and salicylic acid, as well as between BChE inhibitory activity and total phenolic content, was recorded. In model solution studies, it was shown that salicylic acid effectively inhibited BChE activity at concentrations similar to the maximum concentrations found in the test wines. Hierarchical cluster analysis (HCA) revealed that the wines could be divided into three groups. Cabernet Sauvignon and Syrah wines had the highest content of salicylic acid and AChE inhibitory activity, as well as low BChE inhibitory activity. Pinot noir, Tempranillo, Regent and Rondo wines showed the lowest content of salicylic acid and low AChE inhibitory activity. Garnacha tinta, Merlot, Montepulciano and Negroamaro wines had a medium content of salicylic acid, and the highest or medium BChE inhibitory activity. This work is important for both the wine industry and for health protection
Sudden cardiac event on a sea-going ship and recognition of a work-related accident
Objectives. Evaluation of the effect of selected work environment factors on a sea-going ship on
the occurrence of a sudden cardiac event and its recognition as a work-related accident.
Background. Sudden cardiac events, myocardial infarction in particular, among crews of seagoing
ships are the most frequent reasons for fatal morbid events. In more than 20% of such
cases, conditions and organization of work at sea are found to be of essential importance.
Problems with certification are related with the assessment of the significance and impact of
specific work environment factors overlapping with classic genetic and environmental factors of
diseases of atherosclerotic origin.
Material and methods. The analysis embraced medical documentation on the state of health
and working conditions at sea concerning 30 crewmembers of Polish sea-going vessels, who had
suffered from sudden cardiac events in the years 1998–2009. The impact of selected work
environment factors on the legitimacy of legal recognition of the event as a work-related accident
was analysed by Fisher’s test and multi-factorial regression.
Results. The presence of classic genetic and environmental risk factors of cardiovascular events
was confirmed in all persons examined. A significant effect on destabilization of the disease,
deterioration of health, and the occurrence of a sudden circulation event was shown to be
strictly related with isometric and dynamic effort, particularly with heat discomfort in the maritime
work environment. This satisfied the legal criteria for recognition of a work-related accident
in half of the cases examined.
Conclusions. Isometric and dynamic effort associated with work under heat stress conditions
may be regarded as a decisive causative factor for a sudden cardiac event and the recognition
of a work-related accident at sea.
(Int Marit Health 2011; 62, 2: 110–115
Distribution of neuronal nitric oxide synthase (nNOS)-immunoreactive elements in the rabbit piriform cortex
The piriform cortex (PC), the primary olfactory cortex, is involved in the processes
of learning and stress response and possibly plays an important role in epileptogenic
activity. The results of several recent studies suggest that those PC neurons
that contain neuronal nitric oxide synthase (nNOS) may play a key role
during spatial learning and in the modulation of initiation, propagation and
generalisation of seizures in various experimental models and may influence
neuronal vulnerability after epileptic insults. The aim of this study was to characterise
the pattern of distribution and morphology of nNOS-immunoreactive elements
in PC of the adult rabbit. The co-localisation of nNOS and calretinin (CR)
was also studied. The pattern of nNOS-ir within the rabbit PC is similar to that
described previously in other mammals. The morphology of nNOS-ir elements,
namely varicose fibres and Cajal-Retzius cells, suggest that NO has an important
influence on PC function. Surprisingly, in the rabbit PC nNOS-ir elements show
a very low level of co-localisation with CR-ir
Linear optics implementation of general two-photon projective measurement
We will present a method of implementation of general projective measurement
of two-photon polarization state with the use of linear optics elements only.
The scheme presented succeeds with a probability of at least 1/16. For some
specific measurements, (e.g. parity measurement) this probability reaches 1/4.Comment: 8 page
Fractal Noise in Quantum Ballistic and Diffusive Lattice Systems
We demonstrate fractal noise in the quantum evolution of wave packets moving
either ballistically or diffusively in periodic and quasiperiodic tight-binding
lattices, respectively. For the ballistic case with various initial
superpositions we obtain a space-time self-affine fractal which
verify the predictions by Berry for "a particle in a box", in addition to
quantum revivals. For the diffusive case self-similar fractal evolution is also
obtained. These universal fractal features of quantum theory might be useful in
the field of quantum information, for creating efficient quantum algorithms,
and can possibly be detectable in scattering from nanostructures.Comment: 9 pages, 8 postscript figure
- …