70 research outputs found
The effects of nonlocality on the evolution of higher order fluxes in non-equilibrium thermodynamics
The role of gradient dependent constitutive spaces is investigated on the
example of Extended Thermodynamics of rigid heat conductors. Different levels
of nonlocality are developed and the different versions of extended
thermodynamics are classified. The local form of the entropy density plays a
crucial role in the investigations. The entropy inequality is solved under
suitable constitutive assumptions. Balance form of evolution equations is
obtained in special cases. Closure relations are derived on a phenomenological
level.Comment: 16 pages, 1 figur
Variational and Potential Formulation for Stochastic Partial Differential Equations
There is recent interest in finding a potential formulation for Stochastic
Partial Differential Equations (SPDEs). The rationale behind this idea lies in
obtaining all the dynamical information of the system under study from one
single expression. In this Letter we formally provide a general Lagrangian
formalism for SPDEs using the Hojman et al. method. We show that it is possible
to write the corresponding effective potential starting from an s-equivalent
Lagrangean, and that this potential is able to reproduce all the dynamics of
the system, once a special differential operator has been applied. This
procedure can be used to study the complete time evolution and spatial
inhomogeneities of the system under consideration, and is also suitable for the
statistical mechanics description of the problem. Keywords: stochastic partial
differential equations, variational formulation, effective potential. PACS:
45.20.Jj; 02.50.-r; 02.50.Ey.Comment: Letter, 4 pages, no figures; v2: references added, minor change
Covariant description of kinetic freeze out through a finite time-like layer
The Freeze Out (FO) problem is addressed for a covariant FO probability and a
finite FO layer with a time-like normal vector continuing the line of studies
introduced in Ref. [1]. The resulting post FO momentum distribution functions
are presented and discussed. We show that in general the post FO distributions
are non-thermal and asymmetric distributions even for time-like FO situations.Comment: 10 pages, 12 figures, major rewrite with changed content, corrected
typos and new references adde
Impact of Nucleon Mass Shift on the Freeze Out Process
The freeze out of a massive nucleon gas through a finite layer with time-like
normal is studied. The impact of in-medium nucleon mass shift on the freeze out
process is investigated. A considerable modification of the thermodynamical
variables temperature, flow-velocity, energy density and particle density has
been found. Due to the nucleon mass shift the freeze out particle distribution
functions are changed noticeably in comparison with evaluations, which use
vacuum nucleon mass.Comment: submitted to Physical Review
Covariant description of kinetic freeze out through a finite space-like layer
The problem of Freeze Out (FO) in relativistic heavy ion reactions is
addressed. We develop and analyze an idealized one-dimensional model of FO in a
finite layer, based on the covariant FO probability. The resulting post FO
phase-space distributions are discussed for different FO probabilities and
layer thicknesses.Comment: 16 pages, 19 figures, changed content, references adde
Crustal exhumation and depocenter migration from the Alpine orogenic margin towards the Pannonian extensional back-arc basin controlled by inheritance
Evolutionary and socio-cultural influences on feelings and attitudes towards nature: a cross-cultural study
Mounting environmental issues have prompted reconsideration of the human–nature relationship. Accordingly, attitudes to nature, as an important dimension of human–nature interactions, have become a research focus. How feelings and attitudes towards nature are influenced by evolutionary and social-cultural constructions, and whether there is variation between different cultural groups, demands more attention. Using a survey of visitors to two very different National Parks, the New Forest National Park, England and Jiuzhaigou Scenic Area, China, this paper shows that of nationality and living environment, differences between the two nationalities were significant in respect of both attitudes and feelings. Specifically, it demonstrates that the biophilia thesis, which purports that people have an innate and a genetically inherited need for affiliation with nature, is influenced by their socio-cultural environment, in particular their national culture, but also by their current living place. The study contributes to our understanding of sustainable tourism in natural areas
Structural model of human dUTPase in complex with a novel proteinaceous inhibitor
Human deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase), essential for DNA integrity, acts as a survival factor for tumor cells and is a target for cancer chemotherapy. Here we report that the Staphylococcal repressor protein StlSaPIBov1 (Stl) forms strong complex with human dUTPase. Functional analysis reveals that this interaction results in significant reduction of both dUTPase enzymatic activity and DNA binding capability of Stl. We conducted structural studies to understand the mechanism of this mutual inhibition. Small-angle X-ray scattering (SAXS) complemented with hydrogen-deuterium exchange mass spectrometry (HDX-MS) data allowed us to obtain 3D structural models comprising a trimeric dUTPase complexed with separate Stl monomers. These models thus reveal that upon dUTPase-Stl complex formation the functional homodimer of Stl repressor dissociates, which abolishes the DNA binding ability of the protein. Active site forming dUTPase segments were directly identified to be involved in the dUTPase-Stl interaction by HDX-MS, explaining the loss of dUTPase activity upon complexation. Our results provide key novel structural insights that pave the way for further applications of the first potent proteinaceous inhibitor of human dUTPase
Median raphe region stimulation alone generates remote, but not recent fear memory traces
The median raphe region (MRR) is believed to control the fear circuitry indirectly, by influencing the encoding and retrieval of fear memories by amygdala, hippocampus and prefrontal cortex. Here we show that in addition to this established role, MRR stimulation may alone elicit the emergence of remote but not recent fear memories. We substituted electric shocks with optic stimulation of MRR in C57BL/6N male mice in an optogenetic conditioning paradigm and found that stimulations produced agitation, but not fear, during the conditioning trial. Contextual fear, reflected by freezing was not present the next day, but appeared after a 7 days incubation. The optogenetic silencing of MRR during electric shocks ameliorated conditioned fear also seven, but not one day after conditioning. The optogenetic stimulation patterns (50Hz theta burst and 20Hz) used in our tests elicited serotonin release in vitro and lead to activation primarily in the periaqueductal gray examined by c-Fos immunohistochemistry. Earlier studies demonstrated that fear can be induced acutely by stimulation of several subcortical centers, which, however, do not generate persistent fear memories. Here we show that the MRR also elicits fear, but this develops slowly over time, likely by plastic changes induced by the area and its connections. These findings assign a specific role to the MRR in fear learning. Particularly, we suggest that this area is responsible for the durable sensitization of fear circuits towards aversive contexts, and by this, it contributes to the persistence of fear memories. This suggests the existence a bottom-up control of fear circuits by the MRR, which complements the top-down control exerted by the medial prefrontal cortex
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