155 research outputs found
Effect of alkali treatment on the milled grain surface protein and physicochemical properties of two contrasting rice varieties
A systematic study was conducted to explore the effect of grain surface proteins on the physicochemical properties (pasting, retrogradation and textural quality) of rice. Milled rice grains of two selected glutinous (Thadokkham-8 (TDK8)) and non-glutinous (Doongara (DG)) varieties were treated with different concentrations (0%, 0.004%, 0.02%, 0.04%, and 0.2% w/v) of NaOH solution for 1 h. After surface protein removal, the cooked rice grains showed a significant (P 0.05) effect of alkali treatment was observed on the retrogradation thermal temperatures (T, T, and T), but the amount of retrograded starch (as indicated by reduction in ΔH) was decreased significantly (P < 0.05) in both varieties. These findings suggest a good potential of applying alkali pre-treatments in the processing of rice to alter the hardness and stickiness properties of rice
Data base establishment of rice breeding program in Laos
One of the national research priorities is to improve the efficiency of the current breeding and variety testing program in order to accelerate the introduction of better varieties for farmer’s adoption. The database for the rice breeding is the key to achieve the breeding program and would provide valuable scientific information to improve the efficiency of the breeding program for target environments. The objectives of this database were to collect, document and utilize the available data from the national rice breeding program in Laos. Rice breeding program was established at Rice and Cash Crop Research Center in 1991, in collabolation with IRRI, and supported of funding by the government of Switzerland. From 1991 to Philippines and from Thai-IRRI program. Out of 1.627 lines of F2 population, 4 lines were released as TDK and PNG varieties. Out of 64 imported promising lines, 13 lines were released as TDK, TSN, PNG and NTN varieties for different agro climatic zones in Lao PDR. Hybridization at RCCRC was started in 1994, since than, about 272 crosses were made by the Lao breeders. Out of 272 crosses made, so far 8 clones were released as TDK and TSN vareieties and 34 lines were identified as promising lines. Among all parents used in the crossing program at RCCRC, TDK 1 was the dominant parent for evolving promising lines for Lao PDR
The determinant factors for model resolutions obtained using CryoEM method
The CryoEM single particle imaging method has recently received broad
attention in the field of structural biology for determining the structures of
biological molecules. The structures can be resolved to near-atomic resolutions
after rending a large number of CryoEM images measuring molecules in different
orientations. However, the factors for model resolution need to be further
explored. Here, we provide a theoretical framework in conjunction with
numerical simulations to gauge the influence of several key factors that are
determinant in model resolution. We found that the number of measured
projection images and the quality of each measurement (quantified using average
signal-noise-ratio) can be combined to a single factor, which is dominant to
the constructed model resolution. Furthermore, the intrinsic thermal motion of
the molecules and the defocus levels of the electron microscope both have
significant effects on the model resolution. These effects can be
quantitatively summarized using an analytical formula that provides a
theoretical guideline on structure resolutions for given experimental
measurements
Potential of Australian Bermudagrasses (\u3cem\u3eCynodon\u3c/em\u3e spp.) for Pasture in Subtropical Australia
In Australia, little work has been carried out on the improvement of tropical or subtropical pastures in recent years. There seems to be an increasing demand for pastures that can withstand heavy grazing, while producing high yields of high quality forage in the humid subtropical regions of Australia. Most graziers, who live in these areas, have small acreages, which they graze intensively. Cynodon spp. represent a potential source of grasses with these attributes. This study will evaluate the pasture potential of a large number of bermudagrass (Cynodon spp.) ecotypes collected from across Australia
Structure of Spontaneous UP and DOWN Transitions Self-Organizing in a Cortical Network Model
Synaptic plasticity is considered to play a crucial role in the experience-dependent self-organization of local cortical networks. In the absence of sensory stimuli, cerebral cortex exhibits spontaneous membrane potential transitions between an UP and a DOWN state. To reveal how cortical networks develop spontaneous activity, or conversely, how spontaneous activity structures cortical networks, we analyze the self-organization of a recurrent network model of excitatory and inhibitory neurons, which is realistic enough to replicate UP–DOWN states, with spike-timing-dependent plasticity (STDP). The individual neurons in the self-organized network exhibit a variety of temporal patterns in the two-state transitions. In addition, the model develops a feed-forward network-like structure that produces a diverse repertoire of precise sequences of the UP state. Our model shows that the self-organized activity well resembles the spontaneous activity of cortical networks if STDP is accompanied by the pruning of weak synapses. These results suggest that the two-state membrane potential transitions play an active role in structuring local cortical circuits
Feedforward Inhibition and Synaptic Scaling – Two Sides of the Same Coin?
Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing
Effect of light energy and temperature on growth of subterranean clover communities / by S. Fukai
xvii, 215 leaves : ill. ; 30 cm.Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 197
Intensification and diversification leading to increased productivity and profitability of rice-based lowland cropping systems in Lao PDR and Cambodia
This paper describes factors determining crop intensification and diversification in lowland rice-based cropping systems in Cambodia and Lao PDR, and discusses how mechanisation may assist increased productivity and profitability in the region. The work is based on two recently completed Australian Centre for International Agricultural Research projects on crop intensification and diversification in these systems in Cambodia and Lao PDR, and a newly commenced project in the same context on mechanisation and value-adding for diversification. Both water and labour availability are identified as key resource limitations for intensification and diversification of rice-based cropping systems. The policy implications of these and other factors leading to increased productivity and profitability are discussed
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