Scale and tempo of brain expansion in the course of human evolution implies that this process was driven by a positive feedback. The “cultural drive” hypothesis suggests a possible mechanism for the ...runaway brain‐culture coevolution wherein high‐fidelity social learning results in accumulation of cultural traditions which, in turn, promote selection for still more efficient social learning. Here we explore this evolutionary mechanism by means of computer modeling. Simulations confirm its plausibility in a social species in a socio‐ecological situation that makes the sporadic invention of new beneficial and cognitively demanding behaviors possible. The chances for the runaway brain‐culture coevolution increase when some of the culturally transmitted behaviors are individually beneficial while the others are group‐beneficial. In this case, “cultural drive” is possible under varying levels of between‐group competition and migration. Modeling implies that brain expansion can receive additional boost if the evolving mechanisms of social learning are costly in terms of brain expansion (e.g., rely on complex neuronal circuits) and tolerant to the complexity of information transferred, that is, make it possible to transfer complex skills and concepts easily. Human language presumably fits this description. Modeling also confirms that the runaway brain‐culture coevolution can be accelerated by additional positive feedback loops via population growth and life span extension, and that between‐group competition and cultural group selection can facilitate the propagation of group‐beneficial behaviors and remove maladaptive cultural traditions from the population's culture, which individual selection is unable to do.
Extremely rapid brain expansion in the course of human evolution implies that this process was driven by a positive feedback. The “cultural drive” hypothesis suggests a possible mechanism for the runaway brain‐culture coevolution wherein high‐fidelity social learning results in accumulation of cultural traditions which, in turn, promote selection for still more efficient social learning. Here we explore this evolutionary mechanism by means of computer modeling and show that the conditions necessary for a powerful “cultural drive” are compatible with the current knowledge of the ecology and social organization of the Pleistocene Homo species.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Hamiltonian theory for collective longitudinally polarized gluon excitations (plasmons) interacting with classical high-energy test color-charged particle propagating through a high-temperature gluon ...plasma is developed. A generalization of the Lie-Poisson bracket to the case of a continuous medium involving bosonic normal field variable ak⁎a and a non-Abelian color charge Qa is performed and the corresponding Hamilton equations are presented. The canonical transformations including simultaneously both bosonic degrees of freedom of the soft collective excitations and degree of freedom of hard test particle connecting with its color charge in the hot gluon plasma are written out. A complete system of the canonicity conditions for these transformations is derived. The notion of the plasmon number density Nkaa1′, which is a nontrivial matrix in the color space, is introduced. An explicit form of the effective fourth-order Hamiltonian describing the elastic scattering of a plasmon off a hard color particle is found and the self-consistent system of Boltzmann-type kinetic equations taking into account the time evolution of the mean value of the color charge of the hard particle is obtained. On the basis of these equations, a model problem of the interaction of two infinitely narrow wave packets is considered. A system of nonlinear first-order ordinary differential equations defining the dynamics of the interaction of the colorless Nkl and color Wkl components of the plasmon number density is derived. The problem of determining the third- and fourth-order coefficient functions entering into the canonical transformations of the original bosonic variable ak⁎a and color charge Qa is discussed. With the help of the coefficient functions obtained, a complete effective amplitude of the elastic scattering of plasmon off hard test particle is written out.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Thermal aggregation of bovine serum albumin (BSA) has been studied using dynamic light scattering, asymmetric flow field-flow fractionation and analytical ultracentrifugation. The studies were ...carried out at fixed temperatures (60°C, 65°C, 70°C and 80°C) in 0.1 M phosphate buffer, pH 7.0, at BSA concentration of 1 mg/ml. Thermal denaturation of the protein was studied by differential scanning calorimetry. Analysis of the experimental data shows that at 65°C the stage of protein unfolding and individual stages of protein aggregation are markedly separated in time. This circumstance allowed us to propose the following mechanism of thermal aggregation of BSA. Protein unfolding results in the formation of two forms of the non-native protein with different propensity to aggregation. One of the forms (highly reactive unfolded form, Uhr) is characterized by a high rate of aggregation. Aggregation of Uhr leads to the formation of primary aggregates with the hydrodynamic radius (Rh,1) of 10.3 nm. The second form (low reactive unfolded form, Ulr) participates in the aggregation process by its attachment to the primary aggregates produced by the Uhr form and possesses ability for self-aggregation with formation of stable small-sized aggregates (Ast). At complete exhaustion of Ulr, secondary aggregates with the hydrodynamic radius (Rh,2) of 12.8 nm are formed. At 60°C the rates of unfolding and aggregation are commensurate, at 70°C the rates of formation of the primary and secondary aggregates are commensurate, at 80°C the registration of the initial stages of aggregation is complicated by formation of large-sized aggregates.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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Unsymmetric lipophilic polyamine derivatives are considered as potential antitumor agents. Here, a series of novel symmetric lipophilic polyamines (LPAs) based on norspermine and ...triethylenetetramine (TETA) backbones bearing alkyl substituents with different lengths (from decyl to octadecyl) at C(1) atom of glycerol were synthesized. Performed screening of the cytotoxicity of novel compounds on the panel of tumor cell lines (MCF-7, KB-3-1, B16) and non-malignant fibroblasts hFF3 in vitro revealed a correlation between the length of the aliphatic moieties in LPAs and their toxic effects – LPAs with the shortest decyl substituent were found to exhibit the highest cytotoxicity. Furthermore, norspermine-based LPAs displayed somewhat more pronounced cytotoxicity compared with their TETA-based counterparts. Further mechanistic studies demonstrated that hit LPAs containing the norspermine backbone and tetradecyl or decyl substituents efficiently induced apoptosis in KB-3-1 cells. Moreover, decyl-bearing LPA inhibited motility and enhanced adhesiveness of murine B16 melanoma cells in vitro, showing promising antimetastatic potential. Thus, developed novel symmetric norspermine-based LPAs can be considered as promising anticancer chemotherapeutic candidates.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A fundamental question in neurobiology is how animals integrate external sensory information from their environment with self-generated motor and sensory signals in order to guide motor behavior and ...adaptation. The cerebellum is a vertebrate hindbrain region where all of these signals converge and that has been implicated in the acquisition, coordination, and calibration of motor activity. Theories of cerebellar function postulate that granule cells encode a variety of sensorimotor signals in the cerebellar input layer. These models suggest that representations should be high-dimensional, sparse, and temporally patterned. However, in vivo physiological recordings addressing these points have been limited and in particular have been unable to measure the spatiotemporal dynamics of population-wide activity. In this study, we use both calcium imaging and electrophysiology in the awake larval zebrafish to investigate how cerebellar granule cells encode three types of sensory stimuli as well as stimulus-evoked motor behaviors. We find that a large fraction of all granule cells are active in response to these stimuli, such that representations are not sparse at the population level. We find instead that most responses belong to only one of a small number of distinct activity profiles, which are temporally homogeneous and anatomically clustered. We furthermore identify granule cells that are active during swimming behaviors and others that are multimodal for sensory and motor variables. When we pharmacologically change the threshold of a stimulus-evoked behavior, we observe correlated changes in these representations. Finally, electrophysiological data show no evidence for temporal patterning in the coding of different stimulus durations.
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•We image and record from cerebellar granule cells in behaving larval zebrafish•Sensorimotor representations are dense and not temporally patterned•We also find motor-related activity and multimodal sensorimotor representations•Representations fall into a small number of anatomically clustered response types
Experimental evidence for the long-held theory that granule cells transform sensorimotor information into sparse, temporally patterned representations is lacking. Knogler et al. show that granule cells in behaving zebrafish in fact show dense, low-dimensional, non-temporally patterned activity that is anatomically clustered.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this investigation, we extensively studied the mechanism of antitumor activity of bovine pancreatic RNase A. Using confocal microscopy, we show that after RNase A penetration into HeLa and B16 ...cells, a part of the enzyme remains unbound with the ribonuclease inhibitor (RI), resulting in the decrease in cytosolic RNAs in both types of cells and rRNAs in the nucleoli of HeLa cells. Molecular docking indicates the ability of RNase A to form a complex with Ku70/Ku80 heterodimer, and microscopy data confirm its localization mostly inside the nucleus, which may underlie the mechanism of RNase A penetration into cells and its intracellular traffic. RNase A reduced migration and invasion of tumor cells in vitro. In vivo, in the metastatic model of melanoma, RNase A suppressed metastases in the lungs and changed the expression of EMT markers in the tissue adjacent to metastatic foci; this increased Cdh1 and decreased Tjp1, Fn and Vim, disrupting the favorable tumor microenvironment. A similar pattern was observed for all genes except for Fn in metastatic foci, indicating a decrease in the invasive potential of tumor cells. Bioinformatic analysis of RNase-A-susceptible miRNAs and their regulatory networks showed that the main processes modulated by RNase A in the tumor microenvironment are the regulation of cell adhesion and junction, cell cycle regulation and pathways associated with EMT and tumor progression.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A Hamiltonian theory has been developed for collective quark-antiquark excitations with abnormal relation between chirality and helicity in a high-temperature quark-gluon plasma (QGP). For this ...purpose, Zakharov’s formalism for constructing the wave theory in nonlinear media with dispersion has been used. On the basis of this approach, special canonical transformations are derived including simultaneously bosonic and fermionic degrees of freedom of the collective excitations in the QGP. An explicit form of the effective fourth-order Hamiltonian in powers of creation and annihilation operators of plasmons and plasminos describing processes of elastic scattering of plasminos off plasminos and plasminos off plasmons has been found. The developed approach has been used to construct the Boltzmann-type kinetic equation describing the process of elastic scattering of plasminos off plasminos in the quark-gluon plasma and the effect of the so-called nonlinear Landau damping of soft Fermi excitations. The effective amplitude of plasmino-plasmino interaction defined in the context of the classical Hamiltonian theory has been compared with the corresponding matrix element obtained in the framework of high-temperature quantum chromodynamics in the so-called hard thermal loop approximation. This has enabled us to obtain an explicit form of the vertex and coefficient functions in the effective amplitudes and in the canonical transformations.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A connection between the deformed Duffin–Kemmer–Petiau (DKP) algebra and an extended system of the parafermion trilinear commutation relations for the creation and annihilation operators
a
k
±
and ...for an additional operator
a
0
obeying para-Fermi statistics of order 2 based on the Lie algebra
s
o
(
2
M
+
2
)
is established. An appropriate system of the parafermion coherent states as functions of para-Grassmann numbers is introduced. The representation for the operator
a
0
in terms of generators of the orthogonal group
SO
(2
M
) correctly reproducing action of this operator on the state vectors of Fock space is obtained. A connection of the Geyer operator
a
0
2
with the operator of so-called
G
-parity and with the
CPT
- operator
η
^
5
of the DKP-theory is established. In a para-Grassmann algebra a noncommutative, associative star product
∗
(the Moyal product) as a direct generalization of the star product in the algebra of Grassmann numbers is introduced. Two independent approaches to the calculation of the Moyal product
∗
are considered. It is shown that in calculating the matrix elements in the basis of parafermion coherent states of various operator expressions it should be taken into account constantly that we work in the so-called Ohnuki and Kamefuchi’s generalized state-vector space
U
G
, whose state vectors include para-Grassmann numbers
ξ
k
in their definition, instead of the standard state-vector space
U
(the Fock space).
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
It is important that efficient measures to reduce the airborne transmission of respiratory infectious diseases (including COVID-19) should be formulated as soon as possible to ensure a safe easing of ...lockdown. Ventilation has been widely recognized as an efficient engineering control measure for airborne transmission. Room ventilation with an increased supply of clean outdoor air could dilute the expiratory airborne aerosols to a lower concentration level. However, sufficient increase is beyond the capacity of most of the existing mechanical ventilation systems that were designed to be energy efficient under non-pandemic conditions. We propose an improved control strategy based on source control, which would be achieved by implementing intermittent breaks in room occupancy, specifically that all occupants should leave the room periodically and the room occupancy time should be reduced as much as possible. Under the assumption of good mixing of clean outdoor supply air with room air, the evolution of the concentration in the room of aerosols exhaled by infected person(s) is predicted. The risk of airborne cross-infection is then evaluated by calculating the time-averaged intake fraction. The effectiveness of the strategy is demonstrated for a case study of a typical classroom. This strategy, together with other control measures such as continuous supply of maximum clean air, distancing, face-to-back layout of workstations and reducing activities that increase aerosol generation (e.g., loudly talking and singing), is applicable in classrooms, offices, meeting rooms, conference rooms, etc.
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•Source control of intermittent occupancy proposed for reducing airborne exposure;•Effectiveness of proposed source control strategy applied to a classroom evaluated;•Key influential factors of the effectiveness of proposed strategy identified;
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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