Researchers in marketing have concluded that behavior intentions are not a very good predictor of behavior. It has been suggested that unexpected situations may be causing much of the inconsistency between intentions and behavior. The purpose of this study was to determine the extent to which unexpected situations affect behavior intention - behavior inconsistency. Fifty seven housholds from Tucson, Arizona were studied. For each household, information concerning intended consumption of fifteen foods and beverages was collected. This information included: attitudes toward the foods, social norm effects, past behavior, and intended consumption over the next seven days. In addition, the expectation of thirteen situations occurring and their expected influence on consumption was measured. Seven days later, the subjects were asked to report their actual consumption of the fifteen food products and the actual occurrence and influence of the thirteen situations. In addition to self-reports, garbage analysis was used to measure past behavior and consumption during the seven day experimental period. Correlation and regression analyses were used to assess the extent to which unexpected situations influenced the inconsistency in behavior. The results indicated that unexpected situations do explain some of the inconsistency between intentions and behavior. Unexpected situations explained an average (across products) of between 5.8% and 14.1%, and as much as 53.5% of the variance in behavior inconsistency. However, the influence of situational variables was quite different for each product. In addition, it was found that the amount of inconsistency explained by the situational variables. An interesting findings was that the simple unexpected occurrence or nonoccurrence of a situation also exlained behavior inconsistency, indicating subjective effects of situations are not required to explain behavior. These results have several important implications. First, objectively based measures of situations can be used to explain some types of consumer behavior. This makes situational variables much easier for managers to monitor and control. Situational variables were also found to have generalizable effects across individuals, again indicating that situational variables may be easier for managers to use than was previously supposed. Finally, this research indicates that it would be useful to include situational variables into behavior intentions models, especially when intentions and behavior are not closely related.

Tissue sequestration and biliary elimination are two of the important mechanisms by which mammalian body defends against heavy metal insults. In rats or rabbits that had received Pb, Cd, Hg, As and ²¹⁰Po, these metal ions were sequestered in the choroid plexus at concentrations of Pb, Cd, Hg, As and Po that were 57, 33, 12, 13 and 5 times higher, respectively, than those found in the brain cortex. In addition, the concentrations of these heavy metal ions were many fold greater in the choroid plexus than in the CSF or blood. The accumulation of Pb in the choroid plexus was dose-dependent and time-related. When the choroid plexus was incubated, in vitro, with ouabain, the latter significantly inhibited the uptake of Cd from the CSF side of the choroid plexus. Cystine concentration was four times greater in the choroid plexus than in brain cortex. Results suggest that the choroid plexus sequesters toxic metal and metalloid ions. It appears to do this in order to protect the CSF and brain from toxic heavy metals in the blood. The effect of N-(2,3-dimercaptopropyl) phthalamidic acid (DMPA), meso-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-1-propane sulfonic acid (DMPS) on biliary excretion of Cd was studied in rat chronic intoxication mode. DMPA (0.10 mmol/kg, iv), when given to rats three days after exposure to Cd, elicited within 30 min a 20-fold increase in biliary Cd excretion. GSH in rat bile was also increased three fold as compared to control. Neither DMSA nor DMPS increased biliary Cd or GSH. Upon iv administration, DMPA, not DMSA, appeared in bile. An altered, presumably disulfide, form of DMPS was also found in bile. Incubation of DMPA or DMSA with Cd-saturated MT resulted in the removal of Cd from MT. DMPS, however, promoted the formation of MT polymers. DMPA protected biliary GSH from autoxidation. Gel filtration and autoradiographic study of rat bile samples showed that the radioactivity of Cd was correlated with both GSH and DMPA. The evidence supports the mechanism that the increase of biliary Cd by DMPA is the result of DMPA entering cells and removing Cd from MT. Protection of GSH autoxidation by DMPA may facilitate Cd elimination via the bile.

One result of the search for inexpensive alternative sources of protein has been the rise in interest in aquaculture, the rearing of aquatic organisms under controlled conditions. In this dissertation we examine several management approaches to the efficient rearing of aquatic animals, using mathematical modeling to discover optimal production decisions. In addition we demonstrate the feasibility of simultaneous decision and performance control, providing empirical support for a theoretical extension of traditional variance analysis techniques. The results of three studies are included. In the first we model a situation in which the manager of an aquaculture system must decide when and how many animals to stock initially, how many animals to harvest each period, and when to restock an enclosure in order to maximize contribution. We consider both limited and unlimited growing seasons, solving mixed-integer and linear programs. We examine the effects of technological improvements on production strategies. Consistent improvement in contribution is noted, along with some variation in strategy. In the second study we introduce seasonal variation in revenues and lengthen the growing season. The resulting large-scale real-world mixed-integer problem necessitates the use of a heuristic and two strategies, selective expansion and sieve, in order to achieve a near-optimal solution within a reasonable length of time. In the third study we focus on the uncertainty inherent in the aquaculture environment. We provide empirical evidence of the feasibility of a performance evaluation system which gives explicit consideration to the effects of environmental uncertainty and incorporates intraperiod adaptive behavior on behalf of the individual responsible for implementation of model-specified activities. The system we describe may be used in the simultaneous evaluation of individual and model performances, thus clarifying responsibilities for variances and improving production control.

The structural investigation of Ba₆₋₃ₓLn₈₊₂ₓTi₁₈O₅₄, using the correct (doubled) unit cell, corresponding to space group Pnma (number 62), resulted in an R1 = 5.36%. The structure is made up of a network of corner sharing Ti06 octahedra creating pentagonal and rhombic (perovskite-like) channels. The pentagonal channels are fully occupied by Ba atoms, one rhombic channel is fully occupied by Sm atoms, one rhombic channel is partially occupied by Sm atoms, and one rhombic channel is shared by Ba/Sm atoms. Based on the above site occupancies, the disorders (vacancies and substitutions) were calculated for 0 < x < 0.667. Refinements in space group Pna2t (number 33) were conducted and single phase powders were examined for second harmonic signal generation to support the choice of the centrosymmetric space group Pnma. The solution of the Sm-analogue allowed for a comparison to the previously solved crystal structures of the Pr- and Nd-analogues. The crystal structure determinations of the Pr- and Ndanalogues did not take into account the superstructure reflections that doubled the unit cell and changed the space group. The changes of the dielectric characteristics E', Q, and Tf, by varying the x and/or Ln, of the solid solution Ba₆₋₃ₓLn₈₊₂ₓTi₁₈O₅₄ (Ln = La, Pr, Nd, Sm, and Eu) will be reviewed. The focus of this dissertation has been to address: 1) What structural elements cause E', Q, and Tf to change when Ln = Pr, Nd, or Sm and x is varied along the solid solution. 2) What structural elements cause E', Q, and Tf to change when x = 0.5 and Ln is varied. Previous studies established a correlation between Tf and the occurrence of octahedral tilts for the solid solution BaₓSr₁₋ₓ(Zn⅓Nb⅔)O₃ (a perovskite structure with only four-sided channels). The octahedral tilts for the Pr-, Nd-, and Sm-analogues are compared for the Ba₆₋₃ₓLn₈₊₂ₓTi₁₈O₅₄ solid solution where there are three-, four- and five-sided channels.

The present study was a systematic investigation of hierarchical skill sequences in the beginning reading domain. The hierarchies included skills from the traditional approach to reading which reflect bottom-up processing and skills from the conceptual area of print awareness which reflect top-down processing. Researchers supporting the bottom-up approach view reading as a process in which the child extracts information from the text to gain knowledge of the print. The bottom-up processes examined were in the areas of letter recognition and letter naming, and identification of letter sounds and phonemes. The top-down processing approach views reading as a task in which the child brings his/her past experiences and knowledge about the world to gain information about print. The top-down processes examined were in the areas of print identification, inferring a word in context, and print directionality rules. Hierarchical skill sequences were developed within each of the specific areas reflecting the top-down and bottom-up processing theories. Items were developed to reflect the skill sequences based on the cognitive processes that are necessary for correct performance. This involved varying the task demands imposing various requirements of cognitive processing. The data were from 13,189 Head Start children ranging from 3 to 6 years of age. Latent trait models were constructed to reflect the viii ix hypothesized skill sequences by allowing the aj (discrimination) and bj (difficulty) parameters to be free to vary or by constraining them to be equal to other parameters. To arrive at a preferred model, each latent trait model that represented a hypothesized skill sequence was statistically compared against alternative latent trait models. The results from the present investigation supported the hierarchical skill sequences reflecting skills within the traditional area of reading. However, some of the skill sequences from the conceptual area of print awareness were not clearly supported. While the results provide a deeper understanding of beginning reading skill sequences reflecting top-down and bottom-up processing theories, future research is needed to delineate the specific skills which promote later reading ability once the child is in formal reading instruction.

Discrete controlled Markov chains with finite action space and bounded cost per stage are studied in this dissertation. The performance index function, the exponential average cost (EAC), models risk-sensitivity by means of an exponential (dis)utility function. First, for the finite state space model, the EAC corresponding to a fixed stationary (deterministic) policy is characterized in terms of the spectral radii of matrices associated to irreducible communicating classes of both recurrent and transient states. This result generalizes a well known theorem of Howard and Matheson, which treats the particular case in which the Markov cost chain has only one dosed class of states. Then, it is shown that under strong recurrence conditions, the risk-sensitive model approaches the risk-null model when the risk-sensitivity coefficient is small. However, it is proved and also illustrated by means of examples, that in general, fundamental differences arise between both models, e.g., the EAC may depend on the cost structure at the transient states. In particular, the behavior of the EAC for large risk-sensitivity is also analyzed. After showing that an exponential average optimality equation holds for the countable state space model, a proof of the existence of solutions to that equation for the finite model under a simultaneous Doeblin condition is provided, which is simpler than that given in recent work of Cavazos-Cadena and Fernandez-Gaucherand. The adverse impact of "large risk-sensitivity" on recently obtained conditions for the existence of solutions to an optimality inequality is illustrated by means of an example. Finally, a counterexample is included to show that, unlike previous results for finite models, a controlled Markov chain with infinite state space may not have ultimately stationary optimal policies in the risk-sensitive (exponential) discounted cost case, in general. Moreover, a simultaneous Doeblin condition is satisfied in our example, an assumption that enables the vanishing discount approach in the risk-null case, thus further suggesting that more restrictive conditions than those commonly used in the risk neutral context are needed to develop the mentioned approach for risk-sensitive criteria.

Twenty five surgical specimens of malignant human prostate, 3 lymph nodes with metastatic prostate carcinoma, 5 benign prostate hyperplasia (BPH), 11 normal human prostates, as well as 3 human prostate cell lines (DU-145, PC3 and LNCaP) were examined for the expression of human matrix metalloproteinase-7 gene (MMP-7) from the human collagenase family (originally called PUMP-1 for putative metalloproteinase-1) (Majid Siadat-Pajouh et al. 1991). Northern blots were prepared using total RNA extracted from 18 prostate adenocarcinomas, 4 BPH, 2 lymph nodes with metastatic prostate carcinoma and 11 normal human prostates. When the northern blots were hybridized with ³²P labeled MMP-7 cDNA probes, a 1.2 Kb mRNA was detected in 14 out 18 prostate adenocarcinomas, 1 out of 4 BPH, 1 out of 2 metastatic lymph nodes, and 3 out of 11 normal prostates. The 3 human prostate cell lines did not show any evidence of MMP-7 transcript. In situ hybridization was conducted using a ³⁵S labeled MMP-7 cRNA. In situ hybridization was carried out on seven prostate adenocarcinomas, 2 BPH, and 3 metastatic lymph nodes. In situ hybridization revealed that the MMP-7 gene was expressed in the epithelial cells of primary prostate adenocarcinoma as well as invasive and metastatic cells. MMP-7 expression was also seen focally in some benign epithelial cells but not in inflammatory cells or stroma. The combined results of northern analysis and in situ hybridization indicated that 72% of prostate adenocarcinomas, 66% of metastatic prostatic lymph nodes, 40% of BPH and 27% of normal prostate tissues express MMP-7 transcripts. Additional northern blot analysis was performed using probes to human type IV collagenase, type I collagenase and Stromelysin I in human prostate adenocarcinoma as well as normal prostate tissues. The results indicated that 6 out of 10 adenocarcinoma samples and none of the 4 normal samples were positive for type IV collagenase transcripts. None of the tissues examined for the expression of type I collagenase and stromelysin I were found to express the transcripts of interest at detectable levels. A monclonal antibody was generated against a 10 mer synthetic peptide unique to MMP-7. This antibody was reactive with the native protein in frozen prostate tissues. These data suggest that certain metalloproteinases are differentially expressed in prostatic adenocarcinoma and may play a role in invasion and metastasis.

This work presents scattering measurements and photographs of ammonia ice crystals grown at temperatures from 130 to 180 Kelvins. The prime candidate for the material making up the visible clouds of Jupiter and Saturn is ammonia ice. Spacecraft observations of these planets have constrained the single-scattering properties of the cloud particles. To further investigate the nature of these particles, ammonia ice crystals were grown under conditions simulating the atmosphere of Jupiter and Saturn. The experimental apparatus used to make these measurements includes a glass-walled cylindrical chamber which permits measurement of the scattered light over a wide range of scattering angles and a temperature control system which uses a liquid nitrogen reservoir combined with heaters. The chamber is illuminated by a tungsten lamp through a rapidly spinning filter/polarizer wheel which yields measurements of intensity and linear polarization in each of three colors. A photographic record of the crystals is obtained with a microscope objective, and six linear array detectors measure the scattered light. A variety of crystal shapes and phase functions were seen. A representative selection of scattering measurements and photographs are presented. The data do not resemble theoretical calculations for ammonia cubes, tetrahedra, or octahedra. They do appear similar to microwave analog measurements of the scattering properties of a mix of particle shapes as well as of fluffy particles. The ammonia measurements fall into two groups: one has wavelength-dependent polarization and for size parameters up to about seven the scattering properties can be fit by Mie theory. The second group has wavelength-independent phase functions, implying size parameters of 10 to 50, and has a characteristic signature of polarization varying from -10% to +10%. The data can be used to rule out some models for Jupiter's and Saturn's atmospheres and to guide future modelling efforts. For Jupiter, models with a cloud of ammonia crystals of size parameter equal to about 5 (in the red) are suggested. For Saturn, a model is suggested that has a thin layer of small ammonia crystals (in the Mie range) over a thicker ammonia cloud with the wavelength-independent polarization that is characteristic of larger crystals.