Seasonal patterns of stomatal activity, plant-temperature-based drought stress indices, growth and grain yield of two pearl millet (Pennisetum americanum (L.) Leeke) parental lines and their F₁ hybrid were studied under a sprinkler irrigation gradient system in 1985 and 1986 in Tucson, Arizona. Physiological and morphological measurements of stressed and nonstressed plants were made periodically starting at the panicle initiation stage. Well-defined trends in stomatal conductance (Cg), transpiration (Tr), and photosynthetic (Pn) rates of nonstressed plants were observed over the seasons. Tr increased from 5ug H₂O cm⁻²s⁻¹ at early panicle development stage to a peak of up to 30 ug cm⁻²s⁻¹ at flowering and declined to 10 ug cm⁻²s⁻¹ at maturity. Pn of well-irrigated plants was highest (26 uMoles CO₂ m⁻²s⁻¹) at early flag leaf appearance stage and declined slowly to 14 uMoles m⁻²s⁻¹ at maturity. In extremely stressed plants, Cg, Tr and Pn were highest early in the seasons, lowest in the middle of the seasons, and slightly increased towards the end of the seasons. The seasonal trends in stomatal response depended on the stage of plant growth and vapor pressure deficit of the air. Transpiration efficiency was highest at partial stomatal closure. Morphologically, the F₁ hybrid was more like its male than its female parent. The female parent produced less dry matter, had thinner leaves and greater ratio of leaf to stem dry matter, and yielded less grain than the other genotypes. The results indicated that leaf:stem ratio can be a useful selection criterion of drought avoiding genotypes. Plants that develop stems and heads rapidly (low leaf:stem ratio) are more desirable under stress than plants that tend to become leafy. Decreases in Tr, Pn, dry matter and grain yield due to stress could be assessed with canopy or leaf temperature, canopy minus air or leaf minus air temperature, and crop (CWSI) or leaf (LWSI) water stress indices. CWSI and LWSI were more desirable in assessing stress than the other indices. CWSI is effective in assessing the magnitude of stress in a crop stand, while LWSI may be useful in situations where use of the infrared thermometer is difficult.

A survey of leaf mineral concentration of cultivated jojoba was conducted by selecting male and female plants of varying sizes. Mineral concentrations in jojoba were within the expected range for most cultivated plants. Nitrogen, P and Zn were higher in young leaves but K, Ca, Mg, Na and Mn were higher in old leaves. Iron and Cu were similar in old and young leaves. The order of jojoba leaf concentration was: N>K>Ca>Mg>Na>P and Fe>Mn>Zn>Cu. Soil macronutrients, Mn and Cu were adequate for jojoba growth but zinc and Fe were lower than accepted critical values for most crops. For a better understanding of jojoba mineral nutrition, a second experiment was conducted in greenhouse sand culture. Levels of 0, 4, 10, 50, and 100 ppm N in solution culture were evaluated on growth, N and P leaf concentration. Fifty ppm of solution N was adequate for optimum vegetative growth, shoot dry weight production and shoot N concentration (1.96 %) of jojoba plants. Nitrogen was higher in young (2.52%) than old leaves (1.52%) and increased with increments of N rates, as did shoot dry weight, shoot N and shoot P concentrations. Root dry weight did not change with N treatment levels but root N concentration increased with rate. Jojoba plants under field conditions are subjected to water stress and little information is available regarding the effect on leaf mineral concentration. Therefore, a greenhouse sand culture experiment was conducted to study irrigation fequencies of 3 min once every: 1) 2 hr for 10 hr/day, 2) day, 3) other day and 4) 4 days on growth of two clones and foliar, shoot and root N and P concentrations. Also, leaf water potentials were monitored. Vegetative growth increments were similar among treatments but treatment 3 resulted in statistically greater shoot and root dry weight. Leaf N concentration was similar among treatments but root N increased with greater moisture stress. Shoot P concentrations decreased with increasing water stress but root P did not show any pattern. The threshold leaf water potentials for jojoba growth cessation was in the range of -3.0 to -3.5 Mpa.

No description available.

No description available.

This study evaluated relative responses of two grain sorghum (Sorghum bicolor (L.) Moench) hybrids to moisture stress treatments imposed during the seedling, early boot, flowering and grain-filling stages. The two hybrids, T.E. Y77 and FUNK HW6125, are high and low yielding respectively, having similar maturity periods. Twelve phenological characters were measured. The height to upper leaf collar, peduncle exsertion, panicle length, total plant height and total leaf area showed significant differences between the hybrids. Early boot stage stress was most sensitive to vegetative characters. T.E. Y77 produced more heads/m², grains, panicle, 500 grain weight (seed size), and grain yield/ha than FUNK HW 6125 across all treatments. Seed size was the most important determinant of grain yield in both hybrids. Moisture stress during the seedling and early boot stages enhanced grain yield, whereas during the grain-filling stage it was detrimental to grain yield in both hybrids.

Dietary intake for female college students representing both athletic and nonathletic groups was studied using 3-day food records to determine whether there was difference in nutrient intake between groups. Body composition and nutritional beliefs were evaluated. Groups included: repertory dance (n = 4), gymnastics (n = 6), basketball (n = 6), cross-country runners (n = 5), volleyball (n = 4), and softball (n = 8). All groups had adequate calorie, high protein, low iron, zinc intake. All groups except volleyball had high vitamin C intake. Body composition ranged from 13.6%-21.7% fat. Eighty-six percent considered themselves over their optimal weight. A majority wanted more information on nutrition (75%) and on weight control (82%). I conclude there is no significant difference between dietary intake of athletic college women as compared to a nonathletic group, there is no significant difference in dietary intake among groups of athletic women, and athletic women consider dietary intake and nutrition knowledge to be important factors in training and competition.

No description available.

No description available.

Due to their unique characteristics, military domains contain various peculiarities that directly or indirectly and favourably or unfavourably impact the development of software products. Observations of systems development in the Brazilian Navy for many years have shown that systems are developed and delivered usually with many delays, and during development there are many changes to the requirements initially elicited. Since many authors in the software engineering literature agree that problems in requirements account for more than 70% of total system development failures, it seemed to be logical that any effort to solve the problems encountered in the military environment should start focusing on the requirements area. Currently several techniques and approaches already exist that support the execution of activities in this phase. With this abundance of techniques, it becomes a difficult task for the analysts to select the best technique in a given circumstance. To support the selection of these techniques, several frameworks were also created, each one guided by a respective group of influencing factors. This study examined, in a detailed manner, these techniques and frameworks, and noticed that there are still issues to be addressed to guide the selection of elicitation techniques, especially in a complex environment such as the military one. To elicit these issues an exploratory qualitative research was performed. The results showed that social issues rather than technical ones were the main concern in the domain under study. Issues such as hierarchy and high staff turnover interfere in the requirements process but are yet not addressed. The findings of the qualitative research are the first contribution of the thesis. Based on these results this research proposed a novel framework for requirements elicitation within the context of a military environment taking into account social and technical factors, which is the second contribution of the thesis. Such a framework was developed following Conflict Theory from sociology. This framework organized a selection of techniques based on possible solutions to conflicts. Finally, the solution was evaluated to assess its efficacy. This evaluation was based on qualitative and quantitative research. Based on the evaluation results the framework was updated.

Renewable energy technologies are infrequently evaluated with regard to water use for electricity generation; however traditional thermoelectric power generation uses approximately 50% of the water withdrawn in the US. To address problems of this water-energy nexus, we explore the replacement of existing electricity generation plants by renewable technologies, and the effect of this replacement on water use. Using a binary mixed integer linear programing model, we explore how the replacement of traditional thermoelectric generation with renewable solar and wind technologies can reduce future water demands for power generation. Three case study scenarios focusing on the replacement of the J.T. Deely station, a retiring coal thermoelectric generation plant in Texas, demonstrate a significant decrease in water requirements. In each case study, we replace the generation capacity of the retiring thermoelectric plant with three potential alternative technologies: solar photovoltaic (PV) panels, concentrated solar power (CSP), and horizontal axis wind turbines (HAWT). The first case study, which was performed with no limits on the land area available for new renewable energy installations, demonstrated the water savings potential of a range of different technology portfolios. Our second case study examined the replacement while constrained by finite available land area for new installations. This demonstrated the trade-off between land-use efficient technologies with water-use efficiency. Results from our third case study, which explored the replacement of a gas-fired plant with a capacity equivalent to the J. T. Deely station, demonstrated that more water efficient thermoelectric generation technologies produce lower percentages of water savings, and in two scenarios the proposed portfolios require more water than the replaced plant. Comparison of multiple aspects of our model results with those from existing models shows comparable values for land-use per unit of electricity generation and proposed plant size. An evaluation of the estimated hourly generation of our model’s proposed solution suggests the need for a trade-off between the intermittency of a technology and the required water use. As we estimate the “costs� of alternative energy, our results suggest the need to include in the expression the resulting water savings.