Experimental investigation on extruded snack products from rice and Mung bean : optimization of parameters

Experiments were undertaken to study effect of initial conditions on the expansion ratio of two grains in a laboratory scale, single speed, single screw extruder at Naresuan University, Thailand. Jasmine rice and Mung bean were used as the material. Three different initial moisture contents were adjusted for the grains and classified them into three groups according to particle sizes. Mesh sizes used are 12 and 14. Expansion ratio was measured at a constant barrel temperature of 190oC. Response surface methodology was used to obtain optimum conditions between moisture content and particle size of the materials concerned.

Agrobacterium-mediated transformation of indica rice cultivars using binary and superbinary vectors

The Agrobacterium-mediated transformation system was extended to two indica cultivars: a widely cultivated breeding line IR-64 and an elite basmati cultivar Karnal Local. Root tips and shoot tips of seedlings, and scutellar-calli derived from mature seeds showed high-efficiency Agrobacterium tumefaciens infection and stable transformation. In addition to the superbinary vector pTOK233 in Agrobacterium strain LBA4404, almost equally high levels of transformation were achieved with a relatively much smaller (13.1 kb) binary vector (pCAMBIA1301) in a supervirulent host strain AGL1. In both cases, as well as in both cultivars, while 60–90% of the infected explants produced calli resistant to the selectable agent hygromycin, 59–75% of such calli tested positive for GUS. A high level (400 μM) of acetosyringone in the preinduction medium for Agrobacterium and a higher level (500 μM) in the cocultivation medium was necessary for an enhancement in transformation frequency of the binary vector to levels comparable to a superbinary. Hygromycin-resistant calli could be produced from all the explants used. Transformants could be regenerated for both cultivars using the superbinary and binary vector, but only for calli of scutellar origin. In addition to the molecular confirmation of hpt and gus gene transfer and transcription, absence of gene sequences outside the transferred DNA (T-DNA) region confirmed absence of any long T-DNA transfer.

Genotype x culture media interaction effects on regeneration response of three indica rice cultivars

Interactive effects of genotypes with callus induction and regeneration media combinations on green plantlet regeneration response were studied for three indica rice (Oryza sativa L.) cultivars, IR-72, IR-54 and Karnal Local. Isolated mature-embryoswere used to derive scutellar callus and fifteen media combinations involvingMS, N6, R2, SK1 and some modifications were tested. Regeneration percentage as well as the shoot-bud induction frequency were influenced by genotype, callus induction medium, regeneration medium, interaction between genotype and the two media (callus induction and regeneration) as well the interaction between the callus induction medium and regeneration medium. Basal media combination of SK1m (callusing) and MS (regeneration) was found to be the best for cv. Karnal Local in which regeneration frequency of 88% and shoot-bud induction of 233% was observed. In IR-72, the highest regeneration frequency of 47.5% and shoot-bud induction frequency of 77% was obtained on MS-MS combination. In IR-54, highest regeneration frequency (25%) was recorded on MMS(N)-MMS(N) combination, whereas, highest frequency of shoot-bud induction (50%) was observed on MMS(S)-MS combination. Although genotype and the composition of the callus induction basal medium were the major determinants of regeneration response, an overall analysis of variation also revealed a significant interaction between the media used for de-differentiation (callusing) and re-differentiation (plantlet regeneration)

Factors affecting technical efficiency of rice farmers in village reservoir irrigation systems of Sri Lanka

Given the importance of water for rice production, this study examines the factors affecting the technical efficiency (TE) of irrigated rice farmers in village irrigation systems (VIS) in Sri Lanka. Primary data were collected from 460 rice farmers in the Kurunagala District, Sri Lanka, to estimate a stochastic translog production frontier for rice production. The mean TE of rice farming in village irrigation was found to be 0.72, although 63% of rice farmers exceeded this average. The most influential factors of TE are membership of Farmer Organisations (FOs) and the participatory rate in collective actions organised by FOs. The results suggest that enhancement of co-operative arrangements of farmers by strengthening the membership of FOs is considered important for increasing TE in rice farming in VIS.

Synchrony of planting and proportions of susceptible varieties affect rice tungro disease epidemics in the Philippines.

Surveys were conducted in the Philippines from 1995 to 1997 to examine relationships between production environment variables (agroecosystem, synchrony of planting, and varieties planted) and the occurrence of rice tungro disease epidemics using correspondence analyses. The sites covered were Isabela, Nueva Ecija, North Cotabato, and Bohol provinces as well as Bicol region. Tungro disease incidence in farmers’ fields was assessed visually based on typical symptoms. In addition, leaf samples were collected from each field and indexed serologically by enzyme-linked immunosorbent assay for the presence of Rice tungro bacilliform (RTBV) and Rice tungro spherical (RTSV) viruses. Thus, relationships between the production environment variables and four disease variables — visual incidence and double RTBV and RTSV, single RTSV, and single RTBV infections — were examined. A higher association was observed between site and varieties planted as well as site and synchrony of planting than between site and agroecosystem or site and disease variables (visual incidence, double RTBV and RTSV and single RTSV infections). Disease variables depended on both varieties planted and synchrony of planting and correspondence analysis revealed that the low disease incidence in Nueva Ecija was associated with synchronous planting while the high disease incidence in Isabela was associated with the planting of susceptible varieties and asynchronous planting. Such findings suggest that the relationship between the last two factors at a given site is critical to predicting tungro occurrence. Moreover, correspondence analysis of the relationship among disease variables revealed that tungro incidence is associated with not only double RTBV and RTSV infections but also single RTSV infections. Implications of these results on tungro epidemiology and management are discussed.

Catalytic cracking of tars derived from rice hull gasification over goethite and palygorskite

Palygorskite (P), goethite (G), and hydrothermally synthesized goethite (HG) were used as supports for Fe and Ni. The catalytic activity of these materials was investigated involving in P, G and HG (supported Fe and Ni) for catalytic decomposition of biomass tar derived from rice hull gasification. The materials were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and transmission electron microscopy (TEM) with an energy dispersive X-ray (EDS). The catalytic activity of P for removal of tar was significantly better than that of G and HG. However, the activity of G with 6 mass% Ni labeled as Ni6/G (tar conversion 94.6%), which was equal to Fe6Ni6/P (94.4%), was better than Ni6/P (64.4%) and Ni6/HG (46.7%). When the loading of Ni (mass%) was 6 mass% on G, tar conversion had the best value (94.6%) and yield of gaseous products reached 486.9, 167.8 and 22.2 mL/(g·tar) for H2, CO, CH4, respectively. The catalytic activity of goethite supported Ni was better in improving tar conversion and improving increased yield of H2, CO, CH4, which was attributed to the existence of Al/Fe substitution of goethite

Catalytic cracking of tar derived from rice hull gasification over palygorskite-supported Fe and Ni

The catalytic performance of Fe–Ni/PG (PG: palygorskite) catalysts pre-calcined and reduced at 500 ◦C for catalytic decomposition of tar derived through rice hull gasification was investigated. The materials were characterized by using X-ray diffraction, hydrogen temperature reduction, and transmission electron microscopy. The results showed that ferrites with spinel structure ((Fe, Ni)3O4) were formed during preparation of bimetallic systems during calcination and reduction of the precursors (Fe–Ni/PG catalysts) and NiO metal oxide particles were formed over Fe6–Ni9/PG catalyst. The obtained experimental data showed that Fe–Ni/PG catalysts had greater catalytic activity than natural PG. Tar removal using Fe6–Ni9/PG catalyst was as high as Fe10–Ni6/PG catalyst (99.5%). Fe6–Ni9/PG showed greater catalytic activity with greater H2 yield and showed stronger resistance to carbon deposition, attributed to the presence of NiO nanoparticles. Thus, the addition of nickel and iron oxides played an important role in catalytic cracking of rice hull biomass tar.

Effects of rice husk biochar and sugar-mill by-products on methane consumption from two different soils

Methane (CH4) is an important greenhouse gas with a global warming potential (GWP) 25 times greater than carbon dioxide (CO2) that can be produced or consumed in soils depending on environmental conditions and other factors. Biochar application to soils has been shown to reduce CH4 emissions and to increase CH4 consumption. However, the effects of rice husk biochar (RB) have not been thoroughly investigated. Two 60-day laboratory incubation experiments were conducted to investigate the effects of amending two soil types with RB, raw mill mud (MM) and composted mill mud (CM) on soil CH4 consumption and emissions. Soil cores incubated in 1 L glass jars and gas samples were analysed for CH4 using gas chromatography. Average CH4 consumption rates varied from -0.06 to -0.68 g CH4-C( )/ha/d in sandy loam soil and -0.59 to -1.00 g CH4-C/ha/d in clay soil. Application of RB resulted in CH4 uptake of -0.52 to -0.55 g CH4-C/ha/d in sandy loam and -0.76 to -0.91 g CH4-C/ha/d in clay soil. Addition of MM showed low CH4 emissions or consumption at 60% water-filled pore space (WFPS) in both soils. However, at high water contents (>75% WFPS) the application of MM produced high rates of CH4 emissions which were significantly suppressed when RB was added. Cumulative emissions of the MM treatment produced 108.9 g CH4-C/ha at 75% WFPS and 11 459.3 g CH4-C/ha at 90% WFPS in sandy loam soil over a period of 60 days. RB can increase CH4 uptake under low soil water content (SWC) and decrease CH4 emissions under anaerobic conditions. CM expressed more potential to reduce CH4 emissions than those of MM.

The cultivation of human retinal pigment epithelial cells on Bombyx mori silk fibroin

We have presently evaluated membranes prepared from Bombyx mori silk fibroin (BMSF), for their potential use as a prosthetic Bruch’s membrane and carrier substrate for human retinal pigment epithelial (RPE) cell transplantation. Porous BMSF membranes measuring 3 μm in thickness were prepared from aqueous solutions (3% w/v) containing poly(ethylene oxide) (0.09%). The permeability coefficient for membranes was between 3 and 9 × 10-5 cm/s by using Allura red or 70 kDa FITC-dextran respectively. Average pore size (± sd) was 4.9 ± 2.3 µm and 2.9 ± 1.5 µm for upper and lower membrane surfaces respectively. Optimal attachment of ARPE-19 cells to BMSF membrane was achieved by pre-coating with vitronectin (1 µg/mL). ARPE-19 cultures maintained in low serum on BMSF membranes for approximately 8 weeks, developed a cobble-stoned morphology accompanied by a cortical distribution of F-actin and ZO-1. Similar results were obtained using primary cultures of human RPE cells, but cultures took noticeably longer to establish on BMSF compared with tissue culture plastic. These findings encourage further studies of BMSF as a substrate for RPE cell transplantation.

Workplace information literacy : cultivation strategies for 'working smarter' in 21st century libraries

This paper presents a hybrid framework of Swedish cultural practices and Australian grounded theory for organizational development and suggests practical strategies for 'working smarter' in 21st Century libraries. Toward that end, reflective evidence-based practices are offered to incrementally build organizational capacity for asking good questions, selecting authoritative sources, evaluating multiple perspectives, organizing emerging insights, and communicating them to inform, educate, and influence. In addition, to ensure the robust information exchange necessary to collective workplace learning, leadership traits are proposed for ensuring inclusive communication, decision making, and planning processes. These findings emerge from action research projects conducted from 2003 to 2008 in two North American libraries.

Fibroin-based materials support cultivation of limbal stromal cells

Purpose: The silk protein fibroin provides a potential substrate for use in ocular tissue reconstruction. We have previously demonstrated that transparent membranes produced from fibroin support cultivation of human limbal epithelial cells (Tissue Eng A. 14(2008)1203-11). We presently extend this body of work to studies of human limbal stromal cell (HLS) growth on fibroin in the presence and absence of serum. Methods: Primary cultures of HLS cells were established in DMEM/F12 medium supplemented with either 10% fetal bovine serum (FBS) or 2% B27 supplement. Defined keratinocyte serum-free medium (DK-SFM, Invitrogen) was also tested. The resulting cultures were analysed by flow cytometry for expression of CD34, CD90, CD45, and CD141. Cultures grown under each condition were subsequently passaged either onto transparent fibroin membranes prepared from purified fibroin or within 3D scaffolds prepared from partially-solubilised fibroin. Results: HLS cultures were successfully established under each condition, but grew more slowly and passaged poorly in the absence of serum. Cultures grown in 10% FBS were <0.5% CD34+ (keratocytes) and >97% CD90+ (fibroblasts). Cultures established in 2% B27 formed floating spheres and contained >8% CD34+ cells and reduced CD90 expression. Cultures established in DK-SFM displayed traces of epithelial cell growth (CD141), but mostly consisted of CD90+ cells with <1% CD34+ cells. Cells of bone marrow lineage (CD45) were rarely observed under any conditions. Cultures grown in 10% FBS were able to adhere to and proliferate on silk fibroin 3-D scaffolds and transparent films while those grown serum-free could not. Adhesion of HLS cells to fibroin was initially poorer than that displayed on tissue culture plastic. Conclusions: HLS cultures containing cells of predominantly fibroblast lineage can be grown on fibroin-based materials, but this process is dependent upon additional ECM factors such as those provided by serum.

Cost and environmental efficiency of rice farms in South Korea

We examine cost and nutrient use efficiency of farms and determine the cost to move farms to nutrient-efficient operation using Data Envelopment Analysis (DEA) with a dataset of 96 rice farms in Gangwon province of South Korea from 2003 to 2007. Our findings show that improvements in technical efficiency would result in both lower production costs and better environmental performance. It is, however, not costless for farms to move from their current operation to the environmentally efficient operation. On average, this movement would increase production costs by 119% but benefit the water system through an approximately 69% reduction in eutrofying power (EP). The average estimated cost of each EP kg of aggregate nutrient reduction is approximately one thousand two hundred won. For technically efficient farms, there is a trade-off between cost and environmental efficiency. We also find that the environmental performance of farms varies across farms and regions. We suggest that agri-environmental policies should be (re)designed to improve both cost and environmental performance of rice farms.

High-efficiency silencing of a β-glucuronidase gene in rice is correlated with repetitive transgene structure but is independent of DNA methylation

Two transgenic callus lines of rice, stably expressing a β-glucuronidase (GUS) gene, were supertransformed with a set of constructs designed to silence the resident GUS gene. An inverted-repeat (i/r) GUS construct, designed to produce mRNA with self-complementarity, was much more effective than simple sense and antisense constructs at inducing silencing. Supertransforming rice calluses with a direct-repeat (d/r) construct, although not as effective as those with the i/r construct, was also substantially more effective in silencing the resident GUS gene than the simple sense and antisense constructs. DNA hybridisation analyses revealed that every callus line supertransformed with either simple sense or antisense constructs, and subsequently showing GUS silencing, had the silence-inducing transgenes integrated into the plant genome in inverted-repeat configurations. The silenced lines containing i/r and d/r constructs did not necessarily have inverted-repeat T-DNA insertions. There was significant methylation of the GUS sequences in most of the silenced lines but not in the unsilenced lines. However, demethylation treatment of silenced lines with 5-azacytidine did not reverse the post-transcriptional gene silencing (PTGS) of GUS. Whereas the levels of RNA specific to the resident GUS gene were uniformly low in the silenced lines, RNA specific to the inducer transgenes accumulated to a substantial level, and the majority of the i/r RNA was unpolyadenylated. Altogether, these results suggest that both sense- and antisense-mediated gene suppression share a similar molecular basis, that unpolyadenylated RNA plays an important role in PTGS, and that methylation is not essential for PTGS.