Objective constraints of figural goodness

The effects of uniformity, compactness and symmetry on pattern goodness estimates were evaluated in three experiments. Ss were asked to choose the pattern which looks the best in respect to other patterns from given set. Patterns within sets differed from each other in uniformity (Experiment 1), compactness (Experiment 2) and symmetry (Experiment 3). Regression analyses indicated that symmetry was a single good predictor of the frequency of good pattern choice. This result is connected with Koffka's concept of perceptual economy: uniformity and compactness have perceptual advantages in the restricted situations (low energy disposal), while symmetry prevails in unrestricted conditions (high energy disposal)

Current and Shot Noise Measurements in a Carbon Nanotube-Based Spin Diode

Low-temperature measurements of asymmetric carbon nanotube (CNT) quantum dots are reported. The CNTs are end-contacted with one ferromagnetic and one normal-metal electrode. The measurements show a spin-dependent rectification of the current caused by the asymmetry of the device. This rectification occurs for gate voltages for which the normal-metal lead is resonant with a level of the quantum dot. At the gate voltages at which the current is at the maximum current, a significant decrease in the current shot noise is observed

Intrinsic adaptation in autonomous recurrent neural networks

A massively recurrent neural network responds on one side to input stimuli and is autonomously active, on the other side, in the absence of sensory inputs. Stimuli and information processing depends crucially on the qualia of the autonomous-state dynamics of the ongoing neural activity. This default neural activity may be dynamically structured in time and space, showing regular, synchronized, bursting or chaotic activity patterns. We study the influence of non-synaptic plasticity on the default dynamical state of recurrent neural networks. The non-synaptic adaption considered acts on intrinsic neural parameters, such as the threshold and the gain, and is driven by the optimization of the information entropy. We observe, in the presence of the intrinsic adaptation processes, three distinct and globally attracting dynamical regimes, a regular synchronized, an overall chaotic and an intermittent bursting regime. The intermittent bursting regime is characterized by intervals of regular flows, which are quite insensitive to external stimuli, interseeded by chaotic bursts which respond sensitively to input signals. We discuss these finding in the context of self-organized information processing and critical brain dynamics.Comment: 24 pages, 8 figure

Effects of Developmental Training of Basketball Cadets Realised in the Competitive Period

The analysis of effects of a two-month developmental training cycle realised within a basketball season revealed statistically significant positive changes at the multivariate level in components of motor-functional conditioning (fitness) status of the sample of talented basketball cadets (15–16 years). The greatest correlations with discriminant function were found in variables with statistically significant changes at the univariate level, more explicitly in variables of explosive and repetitive power of the upper body and trunk, anaerobic lactic endurance, as well as in jumping type explosive leg power. The presented developmental conditioning training programme, although implemented within the competitive period, induced multiple positive fitness effects between the two control time points in this sample of basketball players. The authors suggest that, to assess power of shoulders and upper back, the test overgrip pull-up should not be applied to basketball players of this age due to its poor sensitivity. Instead, they propose the undergrip pull-up test , which is a facilitated version of the same test. The results presented in this article reinforce experienced opinion of experts that, in the training process with youth teams, the developmental conditioning training programme is effectively applicable throughout the entire competitive season. The proposed training model is a system of various training procedures, operating synergistically, aimed at enhancing integral fitness (preparedness) of basketball players. Further investigations should be focused on assessing effects of both the proposed and other developmental training cycle programmes, by means of assessing and monitoring actual quality (overall performance) of players, on the one hand, and, on the other, by following-up hormonal and biochemical changes over multiple time points

Ispitivanje antioksidativnih mehanizama kempferola sa hidroksi radikalom i superoksid radikal anjonom

Kaempferol, one of the most bioactive plant flavonoids was theoretically (at M05-2X/6-311G(d,p) level of theory) investigated for its ability scavange potentially highly damaging hydroxyl and superoxide anion radicals. Theoretical calculations point to HAT and SPLET mechanisms as operative for kaempferol in all solvents under investigations.Teoretski (na M05-2X/6-311G(d,p) nivou teorije) je ispitivana sposobnost kempferola, važnog bioaktivnog biljnog jedinjenja flavonoida, da reaguje sa potencijalno veoma štetnim hidroksi radikalom i superoksid radikal anjonom. Proračuni su pokazali da su HAT i SPLET mogući mehanizmi u svim rastvaračima

Classical stability and quantum instability of black-hole Cauchy horizons

For a certain region of the parameter space $\{M,e,\Lambda\}$, the Cauchy horizon of a (charged) black hole residing in de Sitter space is classically stable to gravitational perturbations. This implies that, when left to its own devices, classical theory is unable to retain full predictive power: the evolution of physical fields beyond the Cauchy horizon is not uniquely determined by the initial conditions. In this paper we argue that the Cauchy horizon of a Reissner-Nordstr\"om-de Sitter black hole must always be unstable quantum mechanically.Comment: 4 pages; uses ReVTeX; figure available upon request to [email protected]

The Cosmological Constant and Advanced Gravitational Wave Detectors

Interferometric gravitational wave detectors could measure the frequency sweep of a binary inspiral [characterized by its chirp mass] to high accuracy. The observed chirp mass is the intrinsic chirp mass of the binary source multiplied by $(1+z)$, where $z$ is the redshift of the source. Assuming a non-zero cosmological constant, we compute the expected redshift distribution of observed events for an advanced LIGO detector. We find that the redshift distribution has a robust and sizable dependence on the cosmological constant; the data from advanced LIGO detectors could provide an independent measurement of the cosmological constant.Comment: 13 pages plus 5 figure, LaTeX. Revised and final version, to appear in Phys. Rev.

First record of the Northern brown shrimp, Farfantepenaeus aztecus (Ives, 1891) (Crustacea: Decapoda: Penaeidae) in the South Adriatic Sea, Montenegro

A single adult female specimen of the Northern brown shrimp, Farfantepenaeus aztecus, a species native to the western Atlantic coasts, was caught in Boka kotorska bay (southern Adriatic Sea) on 19 September 2013. This is the first record of this alien species in the Adriatic Sea

DFT ispitivanje antioksidativne aktivnosti alizarina Red S

Density functional theory calculations were performed to evaluate the antioxidant activity of alizarin red S molecule. The conformational behavior of molecule were analysed at the M06-2X/6-311++G(d,p) method. The most stable conformer of alizarin red S has two IHBs. The expected antioxidant activity of alizarin red S was justified from ionization potential (IPs) and homolytic O-H bond dissociation enthalpy (BDEs) values. Heterolytic O-H bond cleavages (proton dissociation enthalpies, PDEs) were also computed. Calculated IP, BDE, and PA values suggested that one-step H atom transfer (HAT), rather than SPLET or SET-PT, would be the most favored mechanism for explaining the antioxidant activity of alizarin red S in gas phase. In aqueous solution all of three mechanisms were competitive.Upotrebom DFT metode vršena su izračunavanja u cilju određivanja antioksidativne aktivnosti alizarina red S. Konformaciona priroda molekula analizirana ispitana je primenom M06-2X/6-311++G(d,p) metoda. Najstabilniji konformer alizarina red S ima dve unutrašnje vodonične veze. Očekivana antioksidativna aktivnost alizarina red S određena je izračunavanjem vrednosti jonizacionih potencijala (IP) i i vrednosti entalpija homolitičkog raskidanja O-H veza (BDE). Vrednosti entalpije heterolitičkog raskidanja O-H veza (entalpije disocijacije protona, PDE), su takođe izračunate. Izračunate IP, BDE i PA vrednosti ukazuju na to da je jednostepeni transfer H-atoma (HAT), pre nego SPLET ili SET-PT mehanizam, favorizovan u pogledu antioksidativne aktivnosti alizarina red S u gasnoj fazi. U vodenom rastvoru, sva tri mehanizma su konkurentna

Structure and dielectric caracteristics of BaTi1-xSnxO3 ceramic powders

BaTi1-xSnxO3 (BTS) ceramic powders, with different tin content (x = 0-1) were prepared. The BTS powders were calcined at 1370 °C for 4 hours. The structure of these powders was characterized by XRPD method, tetragonal and cubic crystal structures were noticed. Powders were pressed in pellets and sintered at 1370 °C for 1 hour. The dielectric properties of BTS ceramics were measured and the results were reported.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200