Models of the Knee in the Energy Spectrum of Cosmic Rays

The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of several models are summarized, including diffusive acceleration of cosmic rays in shock fronts, acceleration via cannonballs, leakage from the Galaxy, interactions with background particles in the interstellar medium, as well as new high-energy interactions in the atmosphere. The calculated energy spectra and mean logarithmic masses are compiled and compared to results from direct and indirect measurements.Comment: 30 pages, 20 figures accepted by Astroparticle Physics captions of figures 1-3 clarified, references adde

Excitatory effects of GABA during ontogeny

Gamma-aminobutyric acid (GABA) is the main inhibitory transmitter in the central nervous system. However, at the early stages of development, GABA has excitatory influences on immature neurons. This review presents contemporary views on the mechanisms of GABAergic excitation and the physiological role of excitatory GABA in generating patterns of network activity in the developing brain. © 2013 Springer Science+Business Media New York

Generation of 10^15 - 10^17 eV photons by UHE CR in the Galactic magnetic filed

We show that the deep expected in the diffuse photon spectrum above the threshold of e+e- pair production, i.e., at energies 10^15 - 10^17 eV, may be absent due to the synchrotron radiation by the electron component of the extragalactic Ultra-High Energy Cosmic Rays (UHE CR) in the Galactic magnetic filed. The mechanism we propose requires small (less than 2x10^-12 G) extragalactic magnetic fields and large fraction of photons in the UHE CR. For a typical photon flux expected in top-down scenarios of UHE CR, the predicted flux in the region of the deep is close to the existing experimental limit. The sensitivity of our mechanism to the extragalactic magnetic field may be used to improve existing bounds on the latter by two orders of magnitude.Comment: 11 pages, LaTeX, 1 .ps figure. Numerical error corrected; references adde

Age-related changes of arginase activity and nitric oxide level in phagocytes and their modulation by thymic mesenchymal stromal cells

Arginine metabolism plays an important role in the activation of phagocytes, which are responsible for initiation, regulation, and resolution of inflammation. Deterioration of phagocyte functions is thought to cause the development of inflammaging and other age-related disorders. Mesenchymal stromal cells are well known for their immunoregulatory properties and ability to modulate activation status of mononuclear phagocytes. We aimed to compare arginase activity and NO production in phagocytes from different sources in young and aged animals, and to explore the effect of syngeneic thymic mesenchymal stromal cells on these parameters in tissue-resident phagocytes. We found that arginine metabolism of tissue-resident mononuclear phagocytes from aged mice is shifted to alternative or anti-inflammatory phenotype, due to a statistically significant arginase activity increase. Syngeneic co-culture with mesenchymal stromal cells greatly stimulates arginase activity and up-regulates nitric oxide generation by tissue mononuclear phagocytes regardless of cell donor age. Such bi-directional influence may be beneficial in clinical application for simultaneous inhibition of inflammation and infectious process

Alignment in Gamma-Hadron Families of Cosmic Rays

Alignment of main fluxes of energy in a target plane is found in families of cosmic ray particles detected in deep lead X-ray chambers. The fraction of events with alignment is unexpectedly large for families with high energy and large number of hadrons. This can be considered as evidence for the existence of coplanar scattering of secondary particles in interaction of particles with superhigh energy, $E_0 > 10^{16}$ eV. Data analysis suggests that production of most aligned groups occurs low above the chamber and is characterized by a coplanar scattering and quasiscaling spectrum of secondaries in the fragmentation region. The most elaborated hypothesis for explanation of alignment is related to the quark-gluon string rupture. However, the problem of theoretical interpretation of our results still remains open.Comment: 15 pages, 2 tables, 6 figures (not included), Stanford University preprint SU-ITP-94-2

The Physics of a Sextet Quark Sector

Electroweak symmetry breaking may be a consequence of color sextet quark chiral symmetry breaking. A special solution of QCD is involved, with a high-energy S-Matrix that can be constructed ``semi-perturbatively'' via the chiral anomaly and reggeon diagrams. An infra-red fixed point and color superconductivity are crucial components of the construction. Infinite momentum physical states contain both quarks and a universal ``anomalous wee gluon'' component, and the spectrum is more limited than is required by confinement and chiral symmetry breaking. The pomeron is approximately a regge pole and the Critical Pomeron describes asymptotic cross-sections. The strong coupling of the pomeron to the electroweak sector could produce large $x$ and $Q^2$ events at HERA, and vector boson pairs at Fermilab. Further evidence for the sextet sector at Fermilab would be a large $E_T$ jet excess, due in part to the non-evolution of ${\alpha}_s$, and other phenomena related to the possibility that top quark production is due to the $\eta_6$. The sextet proton and neutron are the only new baryonic states. Sextet states dominate high energy hadronic cross-sections and stable sextet neutrons could produce both dark matter and ultra high energy cosmic rays. The cosmic ray spectrum knee suggests the effective sextet threshold is between Fermilab and LHC energies, with large cross-section effects expected at the LHC. Jet and vector boson cross-sections will be very much larger than expected, and sextet baryons should also be produced. Double pomeron produced states could provide definitive evidence for the existence of the sextet sector in the initial low luminosity running.Comment: Version to be publishe

Information technology forecasting cyclical economic processes

Розроблено інформаційну технологію прогнозування циклічних економічних процесів, яка характеризується більшою точністю у порівнянні із відомими методами прогнозування на базі теорії періодичних випадкових процесів. Представлено результати прогнозу індексу маркетингу та реклами США на 2011р. і його циклічної компоненти на основі моделі у вигляді циклічного випадкового процесу та періодичного випадкового процесу.The information technology of cyclical economic forecasting processes was designed and characterized with greater accuracy in comparison with the known methods of forecasting based on the theory of periodic random processes. The forecast results of the USA marketing and advertising indexes were presented in 2011 and its cyclical component based on the model in cyclic and periodic form of random process

Cholinergic nociceptive mechanisms in rat meninges and trigeminal Ganglia: Potential implications for migraine pain

© 2017 Shelukhina, Mikhailov, Abushik, Nurullin, Nikolsky and Giniatullin.Background: Parasympathetic innervation of meninges and ability of carbachol, acetylcholine (ACh) receptor (AChR) agonist, to induce headaches suggests contribution of cholinergic mechanisms to primary headaches. However, neurochemical mechanisms of cholinergic regulation of peripheral nociception in meninges, origin place for headache, are almost unknown. Methods: Using electrophysiology, calcium imaging, immunohistochemistry, and staining of meningeal mast cells, we studied effects of cholinergic agents on peripheral nociception in rat hemiskulls and isolated trigeminal neurons. Results: Both ACh and carbachol significantly increased nociceptive firing in peripheral terminals of meningeal trigeminal nerves recorded by local suction electrode. Strong nociceptive firing was also induced by nicotine, implying essential role of nicotinic AChRs in control of excitability of trigeminal nerve endings. Nociceptive firing induced by carbachol was reduced by muscarinic antagonist atropine, whereas the action of nicotine was prevented by the nicotinic blocker d-tubocurarine but was insensitive to the TRPA1 antagonist HC-300033. Carbachol but not nicotine induced massive degranulation of meningeal mast cells known to release multiple pro-nociceptive mediators. Enzymes terminating ACh action, acetylcholinesterase (AChE) and butyrylcholinesterase, were revealed in perivascular meningeal nerves. The inhibitor of AChE neostigmine did not change the firing per se but induced nociceptive activity, sensitive to d-tubocurarine, after pretreatment of meninges with the migraine mediator CGRP. This observation suggested the pro-nociceptive action of endogenous ACh in meninges. Both nicotine and carbachol induced intracellular Ca2+ transients in trigeminal neurons partially overlapping with expression of capsaicin-sensitive TRPV1 receptors. Conclusion: Trigeminal nerve terminals in meninges, as well as dural mast cells and trigeminal ganglion neurons express a repertoire of pro-nociceptive nicotinic and muscarinic AChRs, which could be activated by the ACh released from parasympathetic nerves. These receptors represent a potential target for novel therapeutic interventions in trigeminal pain and probably in migraine