Density fluctuations and a first-order chiral phase transition in non-equilibrium

The thermodynamics of a first-order chiral phase transition is considered in the presence of spinodal phase separation using the Nambu-Jona-Lasinio model in the mean field approximation. We focus on the behavior of conserved charge fluctuations. We show that in non-equilibrium the specific heat and charge susceptibilities diverge as the system crosses the isothermal spinodal lines.Comment: 4 pages, 1 figure, to appear in the proceedings of Chiral07, November 13-16 2007, Osaka, Japa

Probing the QCD Critical Point with Higher Moments of Net-proton Multiplicity Distributions

Higher moments of event-by-event net-proton multiplicity distributions are applied to search for the QCD critical point in the heavy ion collisions. It has been demonstrated that higher moments as well as moment products are sensitive to the correlation length and directly connected to the thermodynamic susceptibilities computed in the Lattice QCD and Hadron Resonance Gas (HRG) model. In this paper, we will present measurements for kurtosis ($\kappa$), skewness ($S$) and variance ($\sigma^{2}$) of net-proton multiplicity distributions at the mid-rapidity ($|y|<0.5$) and $0.4<p_{T}<0.8$ GeV/$c$ for Au+Au collisions at $\sqrt{s_{NN}}$=19.6, 39, 62.4, 130 and 200 GeV, Cu+Cu collisions at $\sqrt{s_{NN}}$=22.4, 62.4 and 200 GeV, d+Au collisions at $\sqrt{s_{NN}}$=200 GeV and p+p collisions at $\sqrt{s_{NN}}$=62.4 and 200 GeV. The moment products $\kappa \sigma^{2}$ and $S \sigma$ of net-proton distributions, which are related to volume independent baryon number susceptibility ratio, are compared to the Lattice QCD and HRG model calculations. The $\kappa \sigma^{2}$ and $S \sigma$ of net-proton distributions are consistent with Lattice QCD and HRG model calculations at high energy, which support the thermalization of the colliding system. Deviations of $\kappa \sigma^{2}$ and $S \sigma$ for the Au+Au collisions at low energies from HRG model calculations are also observed.Comment: 10 pages, 8 figures, Proceedings of 27th Winter Workshon on Nuclear Dynamics. Feb. 6-13 (2011

The ρ\rho Spectral Function in a Relativistic Resonance Model

We calculate the spectral function $A_\rho$ of the $\rho$ meson in nuclear matter. The calculation is performed in the {\it low density} approximation, where the in-medium self energy $\Sigma_{med}$ is completely determined by the vacuum $\rho N$ forward scattering amplitude. This amplitude is derived from a relativistic resonance model. In comparison to previous non-relativistic calculations we find a much weaker momentum dependence of $\Sigma_{med}$, especially in the transverse channel. Special attention is paid to uncertainties in the model. Thus, we compare the impact of different coupling schemes for the $RN\rho$ interaction on the results and discuss various resonance parameter sets.Comment: 47 pages, 19 figures, some discussion and formulae added, minor typos removed, accepted for publication in Nuclear Physics

Constraints on vector mesons with finite momentum in nuclear matter

Using the QCD operator product expansion, we derive the real part of the transverse and longitudinal vector-vector correlation function with the quantum numbers of the rho and omega mesons to leading order in density and three momentum (q^2) for energy $\omega^2 --> -\infty$. The operator product expansion provides, through the Borel transformed energy dispersion relation, a model independent constraint for the momentum dependence of the vector meson spectral density in nuclear matter. Existing model calculations for the dispersion effect of the rho meson, where the vector-meson nucleon scattering amplitude is obtained by resonance saturation in the s-channel, in general violate this constraint. We trace this to an inconsistent choice for the form factor of the $\Delta N\rho$ vertex. With a consistent choice, where both the form factor and the coupling constant are obtained from the Bonn potential, the contribution of the $\Delta$ is substantially reduced and we find good agreement with the constraint equation. We briefly comment on the implications of our result for attempts to interpret the enhancement of low-mass dileptons in heavy-ion collisions

Quark Number Fluctuations in a Chiral Model at Finite Baryon Chemical Potential

We discuss the net quark and isovector fluctuations as well as off-diagonal quark flavor susceptibilities along the chiral phase transition line in the Nambu--Jona-Lasinio (NJL) model. The model is formulated at non-zero quark and isospin chemical potentials with non-vanishing vector couplings in the iso-scalar and iso-vector channels. We study the influence of the quark chemical potential on the quark flavour susceptibilities in detail and the dependence of the results on model parameters as well as on the quark mass. The NJL model findings are compared with recent lattice results obtained in two--flavor QCD at finite chemical potential. On a qualitative level, the NJL model provides a consistent description of the dependence of quark number fluctuations on temperature and baryon chemical potential. The phase diagram and the position of the tricritical point in the NJL model are also discussed for different parameter sets.Comment: 33 pages, 11 figures; final version accepted for publication in Phys. Rev.

Ekolalia kommunikointikeinona autismikirjossa ja siihen kohdistetun tutkimuksen tarkastelu

Tiivistelmä. Autismikirjon häiriö on neurokehityksellinen häiriö, jolle on tunnusomaista haasteet kommunikaatiossa ja sosiaalisessa vuorovaikutuksessa sekä toistuvat, rajoittuneet ja poikkeavat toiminnot ja kiinnostuksenkohteet. Ekolalia eli toisen ihmisen puheen toistaminen on äännetty stereotypia ja yksi autismikirjoon kuuluvista kommunikaation ja puheen piirteistä. Ekolalia voidaan luokitella eri muotoihin sen perusteella, milloin puheen toistaminen tapahtuu ja kuinka paljon puheen sisältöä muokataan. Se on usein mielletty automaattiseksi toiminnoksi ilman kommunikatiivisia tavoitteita, mutta käsitys siitä on murroksessa. Tämän kandidaatintutkielman tavoitteena oli tutkia, mikä funktio ekolalialla on autismikirjon henkilöiden kommunikaatiossa ja selvittää, miten suhtautuminen ekolaliaan kommunikointimenetelmänä on muuttunut. Tutkielma suoritettiin kirjallisuuskatsauksena, jossa käsiteltiin kahdeksan vuosina 1983–2021 välillä julkaistujen artikkelien kautta ekolaliaa. Kuutta artikkelia käytettiin vastaamaan ensimmäiseen tutkimuskysymykseen ja kaikkia kahdeksaa artikkelia toiseen tutkimuskysymykseen. Tutkimuksen päätulokseksi muodostui ekolalian moninaisuus. Autismikirjon henkilöt käyttivät ekolaliaa oman toiminnan itsesäätelyyn mutta myös kommunikointiin toisten ihmisten kanssa. Ekolaliaa ilmeni etenkin silloin, kun henkilön kielelliset taidot eivät olleet tilanteeseen adekvaatit tai henkilön kognitiivinen taso on keskivertoa matalampi. Kuitenkin ekolalian lievennetty muoto on usein indikaattori siitä, että henkilön kielelliset taidot ovat kehittymässä. Ekolaliaan suhtautuminen on ollut vaihtelevaa vuosikymmenten varrella, eikä kehitys suhtautumisen suhteen ole ollut kronologista. Ekolalia on nähty joko potentiaalisena menetelmänä kommunikointiin tai oppimista ja kielellistä kehittymistä haittaavana. Käsitys ekolaliasta on kuitenkin nyt muuttumassa ja yhä useampi tutkimus keskittyy mahdollisuuksiin ottaa ekolalia huomioono vuorovaikutuksessa paremmin kuin ennen. Tutkielma tukee näkemystä, että ekolalia on monipuolista, useilla eri tavoilla kommunikatiivista ja ei-kommunikatiivista. Jokapäiväisen onnistuneen vuorovaikutuksen taustalla toimii autismikirjon henkilön lähiympäristön tarjoama informaatio henkilön käyttämän ekolalian perimmäisestä merkityksestä

Вивчення стану ґрунтових вод в умовах міста

The technique of systemization and analysis of heterogenious data by form and contents pursuant to the formation of geoinformational database of underground levels has been developed. Uses of means of the spatial analysis and opportunities of integration Geoinformation technologies with the problemoriented modeling systems essentially expand an opportunity of research and an estimation of change of a level of subsoil waters in territories of city agglomerations

Re-placing place in marketing: A resource-exchange place perspective

This study clarifies the marketing discipline's conceptualization of place by presenting a revised perspective and conceptual framework of place, referred to as REPLACE. Drawing from resource exchange theory and attention restoration theory, the framework problematizes the assumption that places are merely physical locales by foregrounding how places can become inseparable aspects of consumers' lives. We present an alternative resource-based perspective of place, namely as a repository of resources that are potentially available to consumers through exchange processes. These exchange processes, and the complexity of the offered resources, influence consumers' relationship with a locale as well as their sense of well-being. With this alternative perspective, we bridge the place concept to public health and extend the understanding of attachment in service settings

Extraction of Airways with Probabilistic State-space Models and Bayesian Smoothing

Segmenting tree structures is common in several image processing applications. In medical image analysis, reliable segmentations of airways, vessels, neurons and other tree structures can enable important clinical applications. We present a framework for tracking tree structures comprising of elongated branches using probabilistic state-space models and Bayesian smoothing. Unlike most existing methods that proceed with sequential tracking of branches, we present an exploratory method, that is less sensitive to local anomalies in the data due to acquisition noise and/or interfering structures. The evolution of individual branches is modelled using a process model and the observed data is incorporated into the update step of the Bayesian smoother using a measurement model that is based on a multi-scale blob detector. Bayesian smoothing is performed using the RTS (Rauch-Tung-Striebel) smoother, which provides Gaussian density estimates of branch states at each tracking step. We select likely branch seed points automatically based on the response of the blob detection and track from all such seed points using the RTS smoother. We use covariance of the marginal posterior density estimated for each branch to discriminate false positive and true positive branches. The method is evaluated on 3D chest CT scans to track airways. We show that the presented method results in additional branches compared to a baseline method based on region growing on probability images.Comment: 10 pages. Pre-print of the paper accepted at Workshop on Graphs in Biomedical Image Analysis. MICCAI 2017. Quebec Cit