Four studies were conducted to examine whether disinhibited eating among restrained eaters can be differentiated from simple overeating, which occurs among both restrained and unrestrained eaters. We propose that disinhibited eating is caused by the conscious relaxation of inhibitions on food intake. In contrast, simple overeating is an umbrella term encompassing all forms of inadvertent overeating. This includes overeating in response to cues that redefine acceptable intake, and thus allow people to eat more than usual without viewing their food intake as excessive. Disinhibited eating in dieters should result in continued overeating in the absence of factors causing reinhibition, whereas simple overeating does not undermine dietary inhibition and should not result in continued overeating, and may not even be experienced as overeating. Furthermore, unlike simple overeating, disinhibited eating should be accompanied by perceptions that one has eaten too much. Study 1 examines whether restrained eaters who become disinhibited continue to overeat after the disinhibitor is removed. Restrained eaters who were disinhibited by expecting their diets to be broken, and only those restrained eaters, continued to overeat when presented with a second eating opportunity. Studies 2 and 3 assess whether simple overeating in response to normative cues can be distinguished from disinhibited eating in response to cognitive cues related to thinking the diet is or will be broken. In Study 3, restrained eaters who became disinhibited by thinking that their diets would be broken viewed their food intake as excessive and continued to overeat after the disinhibitor was removed. In contrast, restrained eaters who ate a lot after being informed that other study participants had eaten a large amount did not view their food intake as excessive and did not go on to overeat during a second eating opportunity. Study 4 was designed to further examine the role of awareness of having overeaten in disinhibited eating, but no disinhibition effect was observed. Overall, the results suggest that disinhibited eating can be distinguished from simple overeating on the basis of whether restrained eaters view their intake as excessive and whether they continue to overeat during a second eating opportunity.

Four studies were conducted to examine whether disinhibited eating among restrained eaters can be differentiated from simple overeating, which occurs among both restrained and unrestrained eaters. We propose that disinhibited eating is caused by the conscious relaxation of inhibitions on food intake. In contrast, simple overeating is an umbrella term encompassing all forms of inadvertent overeating. This includes overeating in response to cues that redefine acceptable intake, and thus allow people to eat more than usual without viewing their food intake as excessive. Disinhibited eating in dieters should result in continued overeating in the absence of factors causing reinhibition, whereas simple overeating does not undermine dietary inhibition and should not result in continued overeating, and may not even be experienced as overeating. Furthermore, unlike simple overeating, disinhibited eating should be accompanied by perceptions that one has eaten too much. Study 1 examines whether restrained eaters who become disinhibited continue to overeat after the disinhibitor is removed. Restrained eaters who were disinhibited by expecting their diets to be broken, and only those restrained eaters, continued to overeat when presented with a second eating opportunity. Studies 2 and 3 assess whether simple overeating in response to normative cues can be distinguished from disinhibited eating in response to cognitive cues related to thinking the diet is or will be broken. In Study 3, restrained eaters who became disinhibited by thinking that their diets would be broken viewed their food intake as excessive and continued to overeat after the disinhibitor was removed. In contrast, restrained eaters who ate a lot after being informed that other study participants had eaten a large amount did not view their food intake as excessive and did not go on to overeat during a second eating opportunity. Study 4 was designed to further examine the role of awareness of having overeaten in disinhibited eating, but no disinhibition effect was observed. Overall, the results suggest that disinhibited eating can be distinguished from simple overeating on the basis of whether restrained eaters view their intake as excessive and whether they continue to overeat during a second eating opportunity.

An elliptical ring test method is presented to replace the circular ring test method for assessing cracking potential of concrete and other cement-based materials under restrained condition. The latter is recommended by both ASTM (American Society of Testing Materials (C1581/C 1581M-09a) and AASHTO (American Association of State Highway and Transportation Officials (PP34–39, 2004)) as a standard test method for such purpose. However, there is no research published so far on comparing circular and elliptical ring test for assessing the relative likelihood of cracking of concrete and other cement-based materials as proposed in this study. Besides, ASTM proposes to use thin concrete rings with the wall thickness of 1.5 inches while AASHTO to use thick concrete rings with the wall thickness of 3 inches. The implication of these two ring wall thicknesses has not been well studied. The elliptical ring geometry employed here was used to facilitate unique ways of analysing cracking sensitivity of concrete. In line with this, the test program and numerical model developed was focused on investigating the mechanism of the elliptical ring test, irrespective of the concrete materials used which is also novel in this research as efforts towards this assessment are still yet to be published. The new experimental method investigated the use of elliptical rings for assessing the potential of concrete cracking under restrained condition to enable a faster and more reliable assessment of cracking tendency of concrete and other cement-based materials. A series of thin and thick elliptical concrete rings were tested alongside circular ones until cracking. Cracking age, position and propagation in various rings were carefully examined. It was found that thin elliptical rings with appropriate geometry can initiate crack quicker than circular ones which is desirable for accelerating the ring test. There were multiple visible cracks that occurred in elliptical rings and some cracks initiated but did not propagate through the ring wall, an interesting finding reported as the first time by this study. The features of multiple cracks in restrained elliptical rings were examined and their impact on interpreting elliptical ring test results was discussed. In addition, in restrained thin concrete rings, cracks initiated at their inner circumference and propagated towards their outer one while cracks initiated at the outer circumference and propagated towards their inner one for thick rings. To explore the mechanism of this new test method, a numerical model was developed to simulate stress development and crack initiation in concrete ring specimens under restrained shrinkage in which the effect of concrete shrinkage was simulated by an artificial temperature field externally applied on concrete causing the same strain as shrinkage does. A uniform artificial temperature field across the concrete ring wall generated good results and works well for simulating shrinkage cracking of thin concrete rings while an artificial temperature field with linear gradient across the concrete ring wall should be employed in order to predict cracking behaviour of thick concrete rings under restrained shrinkage reasonably well. Stress developed in concrete rings in the restrained shrinkage test was thus obtained through a combined thermal and structural analysis. Based on the maximum tensile stress cracking criterion, cracking age and position of a series of circular and elliptical, thin and thick rings were obtained from numerical analyses. It was found that numerical results match the experimental results in terms of initial cracking ages and position for a number of circular and elliptical concrete rings subject to restrained shrinkage. The effects of ring geometry on cracking in concrete were equally investigated by comparing the behaviour of the elliptical and the circular rings under restrained shrinkage. Both experimental and numerical results indicated that the ratio between the major and the minor semi-axes of an elliptical ring emerges as the main factor which affects the maximum circumferential tensile stress in concrete when subjected to restrained shrinkage. Thin elliptical rings with appropriate geometry can enable crack initiating earlier than circular rings, which is able to accelerate the ring test for assessing the potential of cracking of concrete mixtures. On the other hand, thick elliptical concrete rings do not to possess a favourable geometry effect over circular ones in accelerating ring test due to a relatively weaker restraining effect provided by the central steel ring. The results on crack position and stress development in concrete rings based on numerical analysis were examined to further explore the mechanism of the proposed elliptical ring test for assessing cracking potential of concrete. It was also found that the drying direction of the concrete ring has a substantial influence on the cracking age when thin concrete rings are considered.

In der vorgelegten Studie wurde Modafinil hinsichtlich seiner möglichen antidepressiven und kognitionsverbessernden Wirkung in einem akuten prädiktiven tierexperimentellen Test mit Ratten, dem Forced Swim Test (FST), sowie in einem kognitiven Test zur gerichteten Aufmerksamkeit in der sozialen Diskriminierung (SND), sowie in einem Depressionsmodell der Ratte getestet. Bei der akuten Gabe von Modafinil zeigte sich im FST bei naiven Ratten eine vergleichbare Wirkung mit typischen Antidepressiva, die sich in einer verkürzten immobilen Zeit im Wasserbassin ausdrückte, während durch die akute Administration von Modafinil sich das Diskriminierungsverhalten gesunder Ratten nicht änderte. Zur Induktion depressionsartigen Verhaltens wurde ein 14-tägiges Restrained Stress-Protokoll verwendet. Der FST diente zum Nachweis der depressionsartigen Verhaltensmuster. Gestresste und ungestresste Tiere wurden akut und subchronisch mit Modafinil bzw. Placebo behandelt, um damit die Reversibilität depressionsähnlicher Verhaltensänderungen durch Modafinil zu untersuchen. Das Medikament verbesserte signifikant die depressionsartigen Verhaltensveränderungen und die Aufmerksamkeitsleistung im FST und SND. Mittels Mikrodialyse wurde gezeigt, dass Modafinil die Dopamin-Konzentration im kortikolimbischen System erhöht, so dass dies zu den beobachteten Effekten beitragen könnte. Die vorliegenden Ergebnisse lassen die Schlussfolgerung zu, dass Modafinil antidepressiv-ähnliche und kognitionsverbessernde Wirkungen besitzt und damit eine mögliche Alternative bei der adjuvanten Behandlung menschlicher Depression sein könnte. In weiteren Studien gilt es zu klären, in wie weit die hier gewonnenen Ergebnisse auf die klinische Situation übertragbar sind.

Restraint theory was originally developed to explain differences in eating behaviour between normal-weight and obese individuals. It represented a development from explanations based on obesity per se, and instead proposed the activity of dieting as the causal predictor of eating behaviour. Research has demonstrated that highly restrained individuals are more likely than unrestrained individuals to overeat under certain disinhibiting circumstances. The present thesis aims to investigate some of the functional effects of dietary restraint. Chapter 2 evaluates two different rationales for short-term starvation and the interpretation of the results in terms of the relative importance of the internal versus external cues suggests that external cues are very important in determining (over)eating behaviour. Chapter 3 assesses the functional role of restraint in the adolescent population and provides evidence of a restraint x disinhibitor (anxiety) interaction. Restraint is therefore functional in predicting eating behaviour even in the young adolescent population. Chapter 4 evaluates the role of imagining eating food as a potential disinhibitor and results provide an insight into the determination of highly restrained individuals when faced with a situation where it is possible to maintain high levels of restraint, and I have termed this phenomenon "superinhibition". Chapter 5 psychometrically assesses the various techniques of measuring restraint and results provide clear evidence for the use of the Restraint Scale for identifying chronic dieters. The results of this thesis are analysed in terms of current Restraint Theory, and implications for further research are discussed.

This research was undertaken to study the effects of high performance concrete (HPC) mix design modifications on the propensity of early-age cracking. Seven mixtures were tested: one 35 MPa conventional concrete (CC) mixture made with ordinary Portland cement with blended slag; one typical 50 MPa HPC mixture containing slag and silica fume; and five modified HPC mixtures using extra set-retarder, increased slag replacement, shrinkage-reducing admixture (SRA), pre-saturated lightweight aggregate (LWA), and decreased cement paste content to improve thermal and/or shrinkage properties. The mixtures were tested for durability, mechanical, thermal, and shrinkage properties. All modified HPC mixtures showed reduced shrinkage relative to the HPC control mixture, and the most shrinkage mitigation was observed in the mixture containing LWA. While SRA reduced restrained shrinkage in HPC to the magnitude of CC, it provided very low rapid chloride penetrability, and using LWA in HPC resulted in significant restrained shrinkage reduction compared to CC.

This research was undertaken to study the effects of high performance concrete (HPC) mix design modifications on the propensity of early-age cracking. Seven mixtures were tested: one 35 MPa conventional concrete (CC) mixture made with ordinary Portland cement with blended slag; one typical 50 MPa HPC mixture containing slag and silica fume; and five modified HPC mixtures using extra set-retarder, increased slag replacement, shrinkage-reducing admixture (SRA), pre-saturated lightweight aggregate (LWA), and decreased cement paste content to improve thermal and/or shrinkage properties. The mixtures were tested for durability, mechanical, thermal, and shrinkage properties. All modified HPC mixtures showed reduced shrinkage relative to the HPC control mixture, and the most shrinkage mitigation was observed in the mixture containing LWA. While SRA reduced restrained shrinkage in HPC to the magnitude of CC, it provided very low rapid chloride penetrability, and using LWA in HPC resulted in significant restrained shrinkage reduction compared to CC.

Research evidence is suggestive of a strength model of self-control, also known as ego depletion, in social psychological literature. Engaging in an initial task of self-control depletes a limited resource, resulting in less self-control on a subsequent, unrelated task. The strength model of self-control has been applied to many practical, everyday situations, such as eating behaviors among dieters. Newer studies suggest that blood glucose is the resource consumed during acts of self-control. Consuming glucose seems to "replete" individuals who have been depleted, improving performance and self-control. The current study aimed to examine the effects of ego-depletion on restrained eaters. The hypothesis was that restrained eaters who were depleted by a task of self-control would exhibit more disinhibition on a taste-test task than would restrained eaters who were not depleted. However, if the participants were given glucose following the depletion task, then their self-control would be "repleted" and they would exhibit similar control to that of the non-depleted participants. Contrary to expectations there were no differences between the groups in terms of total amount of cookies consumed. These results are inconsistent with a glucose model of self-control. Suggestions for future research and implications of the findings are discussed.

During its service life, concrete experiences volume changes. One of the types of deformation experienced by concrete is shrinkage. The four main types of shrinkage associated with concrete are plastic, autogeneous, carbonation and drying shrinkage. The volume changes in concrete due to shrinkage can lead to the cracking of the concrete. In the case of reinforced concrete, the cracking may produce a direct path for chloride ions to reach the reinforcing steel. Once chloride ions reach the steel surface, the steel will corrode, which itself can cause cracking, spalling, and delamination of the concrete. The development of concrete shrinkage performance specifications that limit the amount of drying shrinkage for concrete mixtures typically used by the Virginia Department of Transportation (VDOT) were assessed. Five existing shrinkage prediction models were also assessed to determine the accuracy and precision of each model as it pertains to the VDOT mixtures used in this study. The five models assessed were the ACI 209 Code Model, Bazant B3 Model, CEB90 Code Model, Gardner/Lockman Model, and the Sakata Model. The percentage length change limits for the portland cement concrete mixtures were 0.0300 at 28 days, and 0.0400 at 90 days. For the supplemental cementitious material mixtures, the percentage length change limits were 0.0400 at 28 days, and 0.0500 at 90 days. The CEB90 Code model performed best for the portland cement concrete mixtures, while the Gardner/Lockman Model performed best for the supplemental cementitious material mixtures. / Ph. D.

Let G = (V,E) be a graph. A set R is a restrained dominating set (total restrained dominating set, resp.) if every vertex in V − R (V) is adjacent to a vertex in R and (every vertex in V −R) to a vertex in V −R. The restrained domination number of G (total restrained domination number of G), denoted by gamma_r(G) (gamma_tr(G)), is the smallest cardinality of a restrained dominating set (total restrained dominating set) of G. If T is a tree of order n, then gamma_r(T) is greater than or equal to (n+2)/3. We show that gamma_tr(T) is greater than or equal to (n+2)/2. Moreover, we show that if n is congruent to 0 mod 4, then gamma_tr(T) is greater than or equal to (n+2)/2 + 1. We then constructively characterize the extremal trees achieving these lower bounds. Finally, if G is a graph of order n greater than or equal to 2, such that both G and G' are not isomorphic to P_3, then gamma_r(G) + gamma_r(G') is greater than or equal to 4 and less than or equal to n +2. We provide a similar result for total restrained domination and characterize the extremal graphs G of order n achieving these bounds.