Variation in the grain properties of maize hybrids with different grain hardness characteristics and their response to nitrogen fertilizer in terms of milling quality : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Plant Science (Seed Technology) at Massey University

The proportion of grits and flour produced during the dry milling of maize (Zea mays L.) grain is related to the ratio of hard to soft endosperm. The quality standards required vary widely with different end uses, and for dry milling a hybrid with a 'hard' endosperm will usually yield the highest proportion of grits. The texture of the maize endosperm is variable and depends on the maize hybrid and agronomic conditions. In general the available literature showed protein concentration of the grain can be improved by nitrogen fertilizer application, and as the protein content increases, the amount of hard endosperm increases along with value to the miller. A field trial to investigate the effect of nitrogen fertilizer on grain yield and quality, especially grain protein content and hardness, was carried out at the Frewens block, Massey University in the 1994/95 season. Three maize hybrids (P3751, P3787 and A82-8 xNZ84) with three different endosperm textures (soft, intermediate and hard) were grown at two sowings (October and November) with three different nitrogen levels (0, 250, 500kg urea/ha). Urea fertilizer was applied as a side dressing and split into three application times, i.e. at the three leaf stage, at canopy closure and at the 50% silking stage. Plant growth and development were measured by counting the leaf number and leaf appearance rate, formation of the black layer and grain moisture dry down for each hybrid. Grain yields and yield components were measured for different nitrogen treatments at both sowings. Grain protein content was measured from total nitrogen percentage as determined by the Macro Kjeldhal method. Grain hardness was measured by a Stenvert Hardness Tester, while bulk density and grain moisture content were measured by a grain analysis computer. The total number of leaves per plant was greater in hybrid A82-8xNZ84 than hybrids P3787 and P3751 at both sowings, but rate of leaf appearance was faster for the November sowing than the October sowing. Formation of the 'black layer' (i.e physiological maturity) and moisture dry down rate was faster in hybrid P3787 than in hybrids P3751 and A82-8xNZ84 at both sowings. Grain yield was significantly increased at both sowings by the application of 250kg/ha urea, but not by the 500kg urea/ha treatment. Hybrid A82-8xNZ84 gave the highest yield and P3787 gave the lowest. The main yield components which differed between hybrids were number of grains per cob and 100-grain weight. Grain protein content increased progressively in response to the applied nitrogen fertilizer. Protein percentage increased from 8.81% in the control to 10.13% for 500kg urea/ha in the October sowing, and 8.72% in the control to 10.13% for 500kg urea/ha in the November sowing. At both sowings all three hybrids contained the highest amount of protein at the highest urea treatment i.e. 500kg urea/ha. Increased nitrogen application improved grain hardness. For those grains grown under higher nitrogen levels grinding resistance time, energy required for grinding and milling duration time were higher than grains grown when no urea was applied. Grain bulk density (test weight) increased as nitrogen increased. Hybrids A82-8xNZ84 and P3787 had higher grain hardness under the high nitrogen treatment than hybrid P3751. There was a strong, positive relationship between grain protein content and Stenvert Hardness Test parameters at both sowings. When nitrogen was applied grain contained a higher amount of protein (which presumably made grain harder) than the no applied nitrogen treatment. Inherent endosperm texture was not changed by the increased protein percentage as the soft endosperm hybrid did not show an improved hardness, but the intermediate and hard endosperm hybrids showed an improvement in this regard. Results from both sowings indicated grain yield, protein and hardness quality can be improved by applying nitrogen fertilizer. This has implications for dry milling, where hard grain is a necessity for higher grits recovery

Physicochemical and nutritional properties of rice as affected by parboiling steaming time at atmospheric pressure and variety

To elucidate the effect of different parboiling steaming time on the physicochemical and nutritional quality of rice, four varieties, NERICA1, NERICA7, IR841, and WITA4, were soaked at the same initial temperature (85°C) and steamed for 5, 15, 25, 35, and 45 min. NERICA7 steamed for 25 min recorded the highest head rice yield (71.9%). Nonparboiled IR841 recorded the shortest cooking time (17.0 min), while NERICA1 steamed for 35 min recorded the longest cooking time (26.1 min). NERICA1 steamed for 45 min was the hardest (63.2 N), while nonparboiled IR841 was the softest (28.7 N). NERICA7 recorded higher peak and final viscosities across all steaming times compared to the other varieties. NERICA7 steamed for 35 and 45 min recorded the lowest total starch (77.3%) and the highest protein (13.2%) content, respectively. NERICA7 steamed for 25 and 45 min recorded the highest phosphorus (0.166%), magnesium (572 mg/kg), and potassium (2290 mg/kg) content, respectively. We conclude that, depending on desired physicochemical and nutritional properties, specific varieties and steaming times can be selected to achieve those outcomes

Growth hormone plus resistance exercise attenuate structural changes in rat myotendinous junctions resulting from chronic unloading.

Myotendinous junctions (MTJs) are specialized sites on the muscle surface where forces generated by myofibrils are transmitted across the sarcolemma to the extracellular matrix. At the ultrastructural level, the interface between the sarcolemma and extracellular matrix is highly folded and interdigitated at these junctions. In this study, the effect of exercise and growth hormone (GH) treatments on the changes in MTJ structure that occur during muscle unloading, has been analyzed. Twenty hypophysectomized rats were assigned randomly to one of five groups: ambulatory control, hindlimb unloaded, hindlimb unloaded plus exercise (3 daily bouts of 10 climbs up a ladder with 50% body wt attached to the tail), hindlimb unloaded plus GH (2 daily injections of 1 mg/kg body wt, i.p.), and hindlimb unloaded plus exercise plus GH. MTJs of the plantaris muscle were analyzed by electron microscopy and the contact between muscle and tendon was evaluated using an IL/B ratio, where B is the base and IL is the interface length of MTJ's digit-like processes. After 10 days of unloading, the mean IL/B ratio was significantly lower in unloaded (3.92), unloaded plus exercise (4.18), and unloaded plus GH (5.25) groups than in the ambulatory control (6.39) group. On the opposite, the mean IL/B ratio in the group treated with both exercise and GH (7.3) was similar to control. These findings indicate that the interaction between exercise and GH treatments attenuates the changes in MTJ structure that result from chronic unloading and thus can be used as a countermeasure to these adaptations

Analysis of Two Polyhydroxyalkanoate Synthases in Bradyrhizobium japonicum USDA 110

Bradyrhizobium japonicum USDA 110 has five polyhydroxyalkanoate (PHA) synthases (PhaC) annotated in its genome: bll4360 (phaC1), bll6073 (phaC2), blr3732 (phaC3), blr2885 (phaC4), and bll4548 (phaC5). All these proteins possess the catalytic triad and conserved amino acid residues of polyester synthases and are distributed into four different PhaC classes. We obtained mutants in each of these paralogs and analyzed phaC gene expression and PHA production in liquid cultures. Despite the genetic redundancy, only phaC1 and phaC2 were expressed at significant rates, while PHA accumulation in stationary-phase cultures was impaired only in the phaC1 mutant. Meanwhile, the phaC2 mutant produced more PHA than the wild type under this condition, and surprisingly, the phaC3 transcript increased in the phaC2 background. A double mutant, the phaC2 phaC3 mutant, consistently accumulated less PHA than the phaC2 mutant. PHA accumulation in nodule bacteroids followed a pattern similar to that seen in liquid cultures, being prevented in the phaC1 mutant and increased in the phaC2 mutant in relation to the level in the wild type. Therefore, we used these mutants, together with a phaC1 phaC2 double mutant, to study the B. japonicum PHA requirements for survival, competition for nodulation, and plant growth promotion. All mutants, as well as the wild type, survived for 60 days in a carbon-free medium, regardless of their initial PHA contents. When competing for nodulation against the wild type in a 1:1 proportion, the phaC1 and phaC1 phaC2 mutants occupied only 13 to 15% of the nodules, while the phaC2 mutant occupied 81%, suggesting that the PHA polymer is required for successful competitiveness. However, the bacteroid content of PHA did not affect the shoot dry weight accumulation.Fil: Quelas, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Mongiardini, Elias Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Pérez Giménez, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Parisi, Gustavo Daniel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lodeiro, Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Granular synthesis for display of time-varying probability densities

We present a method for displaying time-varying probabilistic information to users using an asynchronous granular synthesis technique. We extend the basic synthesis technique to include distribution over waveform source, spatial position, pitch and time inside waveforms. To enhance the synthesis in interactive contexts, we "quicken" the display by integrating predictions of user behaviour into the sonification. This includes summing the derivatives of the distribution during exploration of static densities, and using Monte-Carlo sampling to predict future user states in nonlinear dynamic systems. These techniques can be used to improve user performance in continuous control systems and in the interactive exploration of high dimensional spaces. This technique provides feedback from users potential goals, and their progress toward achieving them; modulating the feedback with quickening can help shape the users actions toward achieving these goals. We have applied these techniques to a simple nonlinear control problem as well as to the sonification of on-line probabilistic gesture recognition. We are applying these displays to mobile, gestural interfaces, where visual display is often impractical. The granular synthesis approach is theoretically elegant and easily applied in contexts where dynamic probabilistic displays are required

Temporal Data Modeling and Reasoning for Information Systems

Temporal knowledge representation and reasoning is a major research field in Artificial Intelligence, in Database Systems, and in Web and Semantic Web research. The ability to model and process time and calendar data is essential for many applications like appointment scheduling, planning, Web services, temporal and active database systems, adaptive Web applications, and mobile computing applications. This article aims at three complementary goals. First, to provide with a general background in temporal data modeling and reasoning approaches. Second, to serve as an orientation guide for further specific reading. Third, to point to new application fields and research perspectives on temporal knowledge representation and reasoning in the Web and Semantic Web

Sonification of probabilistic feedback through granular synthesis

We describe a method to improve user feedback, specifically the display of time-varying probabilistic information, through asynchronous granular synthesis. We have applied these techniques to challenging control problems as well as to the sonification of online probabilistic gesture recognition. We're using these displays in mobile, gestural interfaces where visual display is often impractical