Driven activation versus thermal activation

Activated dynamics in a glassy system undergoing steady shear deformation is studied by numerical simulations. Our results show that the external driving force has a strong influence on the barrier crossing rate, even though the reaction coordinate is only weakly coupled to the nonequilibrium system. This "driven activation" can be quantified by introducing in the Arrhenius expression an effective temperature, which is close to the one determined from the fluctuation-dissipation relation. This conclusion is supported by analytical results for a simplified model system.Comment: 5 pages, 3 figure

Diffusion-jump model for the combined Brownian and Neel relaxation dynamics of ferrofluids in the presence of external fields and flow

Relaxation of suspended magnetic nanoparticles occurs via Brownian rotational diffusion of the particle as well as internal magnetization dynamics. The latter is often modeled by the stochastic Landau-Lifshitz equation, but its numerical treatment becomes prohibitively expensive in many practical applications due to a time-scale separation between fast, Larmor-type precession and slow, barrier-crossing dynamics. Here, a diffusion-jump model is proposed to take advantage of the time-scale separation and to approximate barrier-crossings as thermally activated jump processes that occur alongside rotational diffusion. The predictions of our diffusion-jump model are compared to reference results obtained by solving the stochastic Landau-Lifshitz equation coupled to rotational Brownian motion. Good agreement is found in the regime of high energy barriers where Neel relaxation can be considered a thermally activated rare event. While many works in the field have neglected N\'eel relaxation altogether, our approach opens the possibility to efficiently include Neel relaxation also into interacting many-particle models

Motor expertise facilitates the accuracy of state extrapolation in perception

Ludolph N, Plöger J, Giese MA, Ilg W. Motor expertise facilitates the accuracy of state extrapolation in perception. PLOS ONE. 2017;12(11): e0187666

Keragaman Genetik Anakan Shorea Leprosula Berdasarkan Penanda Mikrosatelit

Genetic diversity value of offspring might indicate a reproductive success in a forest. Aim in this study was to access genetic diversity values of offspring of Shorea leprosula from different forest types. Leaf samples were collected from six population i.e. a plantation from Carita, and five natural forests from Gunung Bunga A and B, SBK, ITCI and Gunung Lumut. Using four microsatellite markers, the results showed that SBK population maintained high value of genetic diversity. Values of expected heterozygosity (HE) ranged between 0.717 (Carita) and 0.836 (SBK). Values of coefficient inbreeding (F) were insignificant deviated from Hardy-Weinberg Equilibrium, but the value was significant in SBK population. PCA analysis demonstrated a cluster among Gunung Bunga A, SBK, ITCI, and Gunung Lumut. Amova showed that different province significantly contributed 1% to the value of genetic diversity of S. leprosula

\u27Divertual\u27 Learning in Education Leadership: Implications of Teaching Cultural Diversity Online vs. Face to Face

What are the consequences of this teaching-learning situation when graduate students in a Department of Educational Leadership are enrolled in a course on cultural diversity? Might the words on the computer screen be completely unrelated to the humanity, personality, style, interpersonal behaviors, and dispositions of the student writing them, as Menand suggests? Or, might the detachment provide a security in which the most honest and unadulterated discourse can be shared between teacher and students, as some proponents hope? In this chapter we explore responses to this dilemma. We attempt to capture this situation in our label: divertual learning, a neologism coupling diversity with the virtual reality of the learning situation

Karakteristik Pembungaan Dan Sistem Perkawinan Nyamplung (Calophyllum Inophyllum) Pada Hutan Tanaman Di Watusipat, Gunung Kidul

Flowering are influenced by internal factors, such as genetic and phytohormone, and environment factors, such as sunlight and nutrition intake. The flowering characteristics influence fruiting and genetic diversity seedlings through mating systems. This study aims to assess flowering and fruiting characteristics and to determine pattern of mating system of a Calophyllum inophyllum plantation at Watusipat, Gunung Kidul. Flowering and fruiting were observed at 4 locations, 3 parts of crown, and 4 main directions to know the effects of sunlight, nutrition intake and phytohormone in the flowering process. Mating system was assessed by comparing genetic diversity values between parent trees and offsprings. The values of genetic diversity were analyzed using 5 RAPD primers with 17 polymorphic loci. Analysis of variant showed that the locations, crown parts, directions and interaction between a location and direction significantly affected to differences number of flowers and fruits. Values of genetic diversity (h) of parent trees ranged between 0.1471 and 0.3056. The values increased at almost overall offsprings; it ranged between 0.2864 and 0.3750. Values of genetic distance (Da) between parent trees were high and very high (0.197 – 0.364), but the values was decreased between parent trees and their offspring, even between offspring populations. A dendrogram showed two main clusters; first cluster consisted parent trees at up edge with rare trees and second cluster consisted sub cluster parent trees at up edge; sub cluster parent trees at down middle; and sub cluster parent trees at down edge and overall offsprings. Flowering/ fruiting characteristics and pattern of mating systems of C. inophyllum were briefly discussed

Screening Penanda Mikrosatelit Shorea Curtisii Terhadap Jenis-jenis Shorea Penghasil Tengkawang

Screening primer is an effective method to develop microsatellite markers from related taxa. Aim of this study was to develop microsatellite markers of four Shorea producing tengkawang oil, i.e. Shorea gysbertiana, Shorea macrophylla, Shorea pinanga and Shorea stenoptera by screening microsatellite primers of Shorea curtisii. Leaf samples of the four Shorea were collected from nursery at Center for Forest Biotechnology and Tree Improvement Research in Yogyakarta. Four microsatellite primers of S. curtisii i.e. Shc-1, Shc-2, Shc-7 and Shc-9 had been used to screen. Results showed that numerous alleles were shared among the Shorea. The expected heterozygosity (HE) for locus Shc-1 ranged between 0.594 and 0.722; locus Shc-2 ranged between 0.219 and 0.611; locus Shc-7 ranged between 0.594 and 0.778; and locus Shc-9 ranged between 0.594 and 0.844. Coefficient of inbreeding (FIS) value was low and it was insignificant deviated from Hardy-Weinberg Equilibrium (HWE) at almost all loci except Shc-1 of S. pinanga. A dendrogram showed two clusters; S. gysbertsiana and S. macrophylla represented in one cluster, while S. pinanga and S. stenoptera represented in another cluster. Therefore the developed microsatellite markers are possible to be applied for studying population genetics and mating system of these species

Shear-induced anisotropic decay of correlations in hard-sphere colloidal glasses

Spatial correlations of microscopic fluctuations are investigated via real-space experiments and computer simulations of colloidal glasses under steady shear. It is shown that while the distribution of one-particle fluctuations is always isotropic regardless of the relative importance of shear as compared to thermal fluctuations, their spatial correlations show a marked sensitivity to the competition between shear-induced and thermally activated relaxation. Correlations are isotropic in the thermally dominated regime, but develop strong anisotropy as shear dominates the dynamics of microscopic fluctuations. We discuss the relevance of this observation for a better understanding of flow heterogeneity in sheared amorphous solids.Comment: 6 pages, 4 figure

Effective temperatures in a simple model of non-equilibrium, non-Markovian dynamics

The concept of effective temperatures in nonequilibrium systems is studied within an exactly solvable model of non-Markovian diffusion. The system is coupled to two heat baths which are kept at different temperatures: one ('fast') bath associated with an uncorrelated Gaussian noise and a second ('slow') bath with an exponential memory kernel. Various definitions of effective temperatures proposed in the literature are evaluated and compared. The range of validity of these definitions is discussed. It is shown in particular, that the effective temperature defined from the fluctuation-dissipation relation mirrors the temperature of the slow bath in parameter regions corresponding to a separation of time scales. On the contrary, quasi-static and thermodynamic definitions of an effective temperature are found to display the temperature of the fast bath in most parameter regions