2,707 research outputs found
The influence of reconstruction criteria on the sensitive probes of the symmetry potential
Different criteria of constructing clusters and tracing back
resonances from the intermediate-energy neutron-rich HICs are discussed by
employing the updated UrQMD transport model. It is found that both the
phase-space and the coordinate-density criteria affect the single and the
double neutron/proton ratios of free nucleons at small transverse momenta, but
the influence becomes invisible at large transverse momenta. The effect of
different methods of reconstructing freeze-out s on the
ratio is strong in a large kinetic energy region.Comment: 8 pages, 7 fig
Life Under Ban: Jehovah\u27s Witnesses in Russia Since 2017
Since 2017, Jehovah’s Witnesses have been barred from legal practice of their faith in Russia. This marks the first criminalization of a major religious faith in Russia since the collapse of the Soviet Union. For Witnesses, it has been a disturbing return to life under ban, a reality they experienced for decades under Soviet rule. Moreover, all indications suggest that this situation is unlikely to improve in the short term. Russian officials have shown consistent willingness to enforce a broad interpretation of the ban, including through the arrest and imprisonment of individual Witnesses. This article offers an overview of recent developments since 2017, with a particular focus on its impact on individual Witnesses.1 Such analysis is made possible by the wealth of documentation provided by the Jehovah’s Witnesses on their official websites, which carefully track events in Russia
Age-related increase of kynurenic acid in human cerebrospinal fluid-IgG and beta(2)-microglobulin changes
Kynurenic acid (KYNA) is an endogenous metabolite in the kynurenine pathway of tryptophan degradation and is an antagonist at the glycine site of the N-methyl-D-aspartate as well as at the alpha 7 nicotinic cholinergic receptors. In the brain tissue KYNA is synthesised from L-kynurenine by kynurenine aminotransferases (KAT) I and II. A host of immune mediators influence tryptophan degradation. In the present study, the levels of KYNA in cerebrospinal fluid (CSF) and serum in a group of human subjects aged between 25 and 74 years were determined by using a high performance liquid chromatography method. In CSF and serum KAT I and II activities were investigated by radioenzymatic assay, and the levels of β2-microglobulin, a marker for cellular immune activation, were determined by ELISA. The correlations between neurochemical and biological parameters were evaluated. Two subject groups with significantly different ages, i.e. 50 years, p < 0.001, showed statistically significantly different CSF KYNA levels, i.e. 2.84 ± 0.16 fmol/μl vs. 4.09 ± 0.14 fmol/μl, p < 0.001, respectively; but this difference was not seen in serum samples. Interestingly, KYNA is synthesised in CSF principally by KAT I and not KAT II, however no relationship was found between enzyme activity and ageing. A positive relationship between CSF KYNA levels and age of subjects indicates a 95% probability of elevated CSF KYNA with ageing (R = 0.6639, p = 0.0001). KYNA levels significantly correlated with IgG and β2-microglobulin levels (R = 0.5244, p = 0.0049; R = 0.4253, p = 0.043, respectively). No correlation was found between other biological parameters in CSF or serum. In summary, a positive relationship between the CSF KYNA level and ageing was found, and the data would suggest age-dependent increase of kynurenine metabolism in the CNS. An enhancement of CSF IgG and β2-microglobulin levels would suggest an activation of the immune system during ageing. Increased KYNA metabolism may be involved in the hypofunction of the glutamatergic and/or nicotinic cholinergic neurotransmission in the ageing CNS
Nuclear collective dynamics within Vlasov approach
We discuss, in an investigation based on Vlasov equation, the properties of
the isovector modes in nuclear matter and atomic nuclei in relation with the
symmetry energy. We obtain numerically the dipole response and determine the
strength function for various systems, including a chain of Sn isotopes. We
consider for the symmetry energy three parametrizations with density providing
similar values at saturation but which manifest very different slopes around
this point. In this way we can explore how the slope affects the collective
response of finite nuclear systems. We focus first on the dipole polarizability
and show that while the model is able to describe the expected mass dependence,
A^{5/3}, it also demonstrates that this quantity is sensitive to the slope
parameter of the symmetry energy. Then, by considering the Sn isotopic chain,
we investigate the emergence of a collective mode, the Pygmy Dipole Resonance
(PDR), when the number of neutrons in excess increases. We show that the total
energy-weighted sum rule exhausted by this mode has a linear dependence with
the square of isospin I=(N-Z)/A, again sensitive to the slope of the symmetry
energy with density. Therefore the polarization effects in the isovector
density have to play an important role in the dynamics of PDR. These results
provide additional hints in the investigations aiming to extract the properties
of symmetry energy below saturation.Comment: 7 pages, 6 figure
Training and education as factors of socialization
©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Michael Felsberg, Extending Graph-Cut to Continuous Value Domain Minimization, 2007, Canadian Conference on Computer and Robot Vision, 274.http://dx.doi.org/10.1109/CRV.2007.2
The cranking formula and the spurious behaviour of the mass parameters
We discuss some aspects of the approach of the mass parameters by means of
the simple cranking model. In particular, it is well known that the numerical
application of this formula is often subject to ambiguities or contradictions.
It is found that these problems are induced by the presence of two derivatives
in the formula. To overcome these problems, we state a useful ansatz and we
develop a number of simple arguments which tend to justify the removal of these
terms. As soon as this is done, the formula becomes simpler and easier to
interpret. In this respect, it is shown how the shell effects affect the mass
parameters. A number of numerical tests help us in our conclusions.Comment: version 3 corrigendum of the ansatz of section V, corrigendum of the
legend of Fig3. Submission = text file + 5 figure
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