1,852 research outputs found
Retrieval Properties of Hopfield and Correlated Attractors in an Associative Memory Model
We examine a previouly introduced attractor neural network model that
explains the persistent activities of neurons in the anterior ventral temporal
cortex of the brain. In this model, the coexistence of several attractors
including correlated attractors was reported in the cases of finite and
infinite loading. In this paper, by means of a statistical mechanical method,
we study the statics and dynamics of the model in both finite and extensive
loading, mainly focusing on the retrieval properties of the Hopfield and
correlated attractors. In the extensive loading case, we derive the evolution
equations by the dynamical replica theory. We found several characteristic
temporal behaviours, both in the finite and extensive loading cases. The
theoretical results were confirmed by numerical simulations.Comment: 12 pages, 7 figure
Four gene introduction methods affect the shoot regeneration and localization of transgene expression in greenhouse stem explants and in vitro-grown chrysanthemum stem thin cell layers
Gene introduction method (GIM) affected shoot regeneration capacity (SRC) in standard and spray-type chrysanthemums. SRC was both cultivar and GIM-dependent in both in vitro and greenhouse stem explants, the former significantly higher than the latter. Sonication had an SRC-stimulating effect on in vitro explants. Other GIMs (Agrobacterium, biolistics, Agrolistics) had an SRC-inhibiting effect on greenhouse explants. Genotype-dependence of SRC was observed in both in vitro and greenhouse material. SRC is influenced by the explant and regeneration media, which should be modified if altered by the GIM. Shoots derived from all GIM treatments showed normal growth under in vitro and greenhouse conditions, and flowered normally. In addition, this study further shows that explant origin (in vitro versus greenhouse) and cultivar significantly affect the regeneration process, even when an optimized medium is utilized. The integration of the GUS transgene is also GIM-dependent, but in all cases is shown to occur in the venation.
(African Journal of Biotechnology: 2003 2(5): 114-123
Respon Tanaman Kacang-Kacangan yang Bersifat Determinate dan Indeterminate pada Berbagai Kondisi Ketersediaan Air
Growth and yield of soybean and blackgram, having determinate and indeterminate in flowering respectively, were compared under three water regimes. Under well-watered conditions, blackgram continuously produces flowers where under rainfed + irrigation and rainfed condition, two periods of flowering can be distinguished. While only one period of flowering was observed in soybean. The second flush of flowering of blackgram in rainfed and rainfed + irrigation areas occurred during high rain fall. Partial irrigation as much as 80 mm toward the end of pod filling in soybean did not give benefit to soybean, but irrigation stimulate flowering in blackgram and increase yield up to 25%. Thus indeterminate behavior might give higher yield under rainfed condition due to its flexibility of flowering
The Cgl1281-encoding putative transporter of the cation diffusion facilitator family is responsible for alkali-tolerance in Corynebacterium glutamicum
The original publication is available at www.springerlink.com.ArticleARCHIVES OF MICROBIOLOGY. 190(5): 531-538 (2008)journal articl
Robustness of the noise-induced phase synchronization in a general class of limit cycle oscillators
We show that a wide class of uncoupled limit cycle oscillators can be
in-phase synchronized by common weak additive noise. An expression of the
Lyapunov exponent is analytically derived to study the stability of the
noise-driven synchronizing state. The result shows that such a synchronization
can be achieved in a broad class of oscillators with little constraint on their
intrinsic property. On the other hand, the leaky integrate-and-fire neuron
oscillators do not belong to this class, generating intermittent phase slips
according to a power low distribution of their intervals.Comment: 10 pages, 3 figure
Thermodynamics of impurity-enhanced vacancy formation in metals
Hydrogen induced vacancy formation in metals and metal alloys has been of great interest during the past couple of decades. The main reason for this phenomenon, often referred to as the superabundant vacancy formation, is the lowering of vacancy formation energy due to the trapping of hydrogen. By means of thermodynamics, we study the equilibrium vacancy formation in fcc metals (Pd, Ni, Co, and Fe) in correlation with the H amounts. The results of this study are compared and found to be in good agreement with experiments. For the accurate description of the total energy of the metal-hydrogen system, we take into account the binding energies of each trapped impurity, the vibrational entropy of defects, and the thermodynamics of divacancy formation. We demonstrate the effect of vacancy formation energy, the hydrogen binding, and the divacancy binding energy on the total equilibrium vacancy concentration. We show that the divacancy fraction gives the major contribution to the total vacancy fraction at high H fractions and cannot be neglected when studying superabundant vacancies. Our results lead to a novel conclusion that at high hydrogen fractions, superabundant vacancy formation takes place regardless of the binding energy between vacancies and hydrogen. We also propose the reason of superabundant vacancy formation mainly in the fcc phase. The equations obtained within this work can be used for any metal-impurity system, if the impurity occupies an interstitial site in the lattice. Published by AIP Publishing.Peer reviewe
Respon Tanaman Kacang-Kacangan yang Bersifat Determinate dan Indeterminate pada Berbagai Kondisi Ketersediaan Air
Growth and yield of soybean and blackgram, having determinate and indeterminate in flowering respectively, were compared under three water regimes. Under well-watered conditions, blackgram continuously produces flowers where under rainfed + irrigation and rainfed condition, two periods of flowering can be distinguished. While only one period of flowering was observed in soybean. The second flush of flowering of blackgram in rainfed and rainfed + irrigation areas occurred during high rain fall. Partial irrigation as much as 80 mm toward the end of pod filling in soybean did not give benefit to soybean, but irrigation stimulate flowering in blackgram and increase yield up to 25%. Thus indeterminate behavior might give higher yield under rainfed condition due to its flexibility of flowering.  Key words: Determinate, Indeterminate, Flowering, Water stres
Symmetric sequence processing in a recurrent neural network model with a synchronous dynamics
The synchronous dynamics and the stationary states of a recurrent attractor
neural network model with competing synapses between symmetric sequence
processing and Hebbian pattern reconstruction is studied in this work allowing
for the presence of a self-interaction for each unit. Phase diagrams of
stationary states are obtained exhibiting phases of retrieval, symmetric and
period-two cyclic states as well as correlated and frozen-in states, in the
absence of noise. The frozen-in states are destabilised by synaptic noise and
well separated regions of correlated and cyclic states are obtained. Excitatory
or inhibitory self-interactions yield enlarged phases of fixed-point or cyclic
behaviour.Comment: Accepted for publication in Journal of Physics A: Mathematical and
Theoretica
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