Path Integral Estimates of the Quantum Fluctuations of the Relative Soliton-Soliton Velocity in a Gross-Pitaevskii Breather

In this paper, the quantum fluctuations of the relative velocity of constituent solitons in a Gross-Pitaevskii breather are studied. The breather is confined in a weak harmonic trap. These fluctuations are monitored, indirectly, using a two-body correlation function measured at a quarter of the harmonic period after the breather creation. The results of an ab initio quantum Monte Carlo calculation, based on the Feynman-Kac path integration method, are compared with the analytical predictions using the recently suggested approach within the Bogoliubov approximation, and a good agreement is obtained.

Correlations between components of the immune system

Background: No evidence of the possibility to alter a constituent of the immune system without directly affecting one of its associated components has been shown yet. Methods: A schematic model was developed in which two triggers, fasting and splenectomy, were studied for their ability to affect the expression of cell membrane epitopes and the cytokine secretion of out-of-body autogeneic and syngeneic lymphocytes. Results: Fasting decreased expression of CD8 and CD25 and increased TNFα levels. The effect of splenectomy as a trigger was investigated in non-fasting mice by comparing splenectomized and non-splenectomized mice. An increase in the CD8 expression and in TNFα, IFNg, and IL10 secretion was noted. The effect of splenectomy as a trigger was investigated in fasting mice by comparing splenectomized and non-splenectomized mice. Splenectomy had a significant effect on expression of CD25 and CD4 CD25 and on secretion of TNFα, IFNg, and IL10. To determine the effect of keeping the cells in an out-of-body location on the expression of lymphocyte epitopes, tubes kept on top of the cages of the fasting mice were compared with tubes kept on top of empty cages. A significant change in the CD8 expression was noted. To determine the effect of keeping cells in an out-of-body location on cytokine secretion, tubes kept on top of cages were tested for cytokine levels. A significant decrease was noted for the secretion of TNFα and IFNg. Conclusions: The data obtained from this study characterized a system for induction of correlations between two components of the immune system without a transfer of mediators. The study showed that a mouse could affect cells at a distance and alter the expression of surface markers and cytokine secretion following two types of triggers: fasting and/or splenectomy. Thus, an out-of-body correlation can be induced between two components of the immune system.

Vocabulary for Lower Back and Lumbar Pain in Russian Dialects: an Overview

The semantic-motivational and etymological analysis of the Russian dialectal designations of lumbar and lumbar pain is presented. The material was extracted from dictionaries of Russian dialects, from unpublished card files of the Ural University toponymic expedition to the territories of the Russian North and the Upper Volga region, as well as folklore and ethnographic sources related to folk medicine. The main semantic-motivational models underlying the designation of the lower back, which can reflect the idea of the “topography” of this part of the body, correlation with adjacent bodily areas, the functions of the lower back, and pain symptoms are considered. It is noted that in the “lumbar” vocabulary the main place belongs to the names of lumbar pain, the abundance of which is determined by the nature of agricultural labor. It has been shown that several names contain an indication of the localization of pain, but in most cases the nature of the pain is conveyed — cutting, stabbing, aching, etc. The authors analyze linguistic material in combination with folklore and ethnographic: texts of conspiracies, ritual dialogues, descriptions of magical healing practices. Sign complexes are identified, within which the designations of pain symptoms are projected onto methods, means and tools of treatment. In such complexes, the principle of etymological magic can be realized, consistent with the concept of the “witchcraft” origin of pain symptoms. Motivational and etymological solutions for dark words are proposed.

Tan’s two-body contact across the superfluid transition of a planar Bose gas

Tan’s contact is a quantity that unifies many different properties of a low-temperature gas with short-range interactions, from its momentum distribution to its spatial two-body correlation function. Here, we use a Ramsey interferometric method to realize experimentally the thermodynamic definition of the two-body contact, i.e., the change of the internal energy in a small modification of the scattering length. Our measurements are performed on a uniform two-dimensional Bose gas of 87Rb atoms across the Berezinskii–Kosterlitz–Thouless superfluid transition. They connect well to the theoretical predictions in the limiting cases of a strongly degenerate fluid and of a normal gas. They also provide the variation of this key quantity in the critical region, where further theoretical efforts are needed to account for our findings.

A new strategy of crosswell correlation for channel sandstone reservoirs — An example from Daqing oilfield, China

Crosswell correlation for subsurface channel sandstone reservoirs is a difficult problem for geologists worldwide because it is hard for us to know the subsurface sand-body distribution situation. Different correlation methods or strategies result in different sand-body stacking and reservoir connecting models. Sand-body correlation for channel sandstones with only static geologic methods is prone to cause high uncertainties in the analysis for sand-body distribution and connection due to their complexity and heterogeneity. Combining outcrop images and wireline logs, we have evaluated seven channel correlation models. We developed a new channel sand-body correlation strategy with four steps with a case study, combining channel architecture patterns, different correlation models, and tracer test data. The four-step correlation method consists of channel-belt correlation, isolated channel sand-body correlation, barrier and baffle analysis, and impacts of reservoir structure. Furthermore, the channel reservoir connectivity was also analyzed in terms of connection efficiency derived from tracer test data as well as in terms of barrier and baffle obtained from channel-body correlation results. We found that the new correlation workflow integrated with our correlation models reduced the uncertainty of subsurface channel sand-body correlation in the study area. In addition, the channel correlation strategy can approach the subsurface sand-body connection reality of the reservoir distribution and reflect the real production performance in the study area. The correlation strategy and models in the paper could be applied to other analogous subsurface channel reservoirs.