Perceptual studies suggest that the visual system uses the "rigidity" assumption to recover three dimensional structures from motion. Ullman (1984) recently proposed a computational scheme, the incremental rigidity scheme, which uses the rigidity assumptions to recover the structure of rigid and non-rigid objects in motion. The scheme assumes the input to be discrete positions of elements in motion, under orthographic projection. We present formulations of Ullmans' method that use velocity information and perspective projection in the recovery of structure. Theoretical and computer analyses show that the velocity based formulations provide a rough estimate of structure quickly, but are not robust over an extended time period. The stable long term recovery of structure requires disparate views of moving objects. Our analysis raises interesting questions regarding the recovery of structure from motion in the human visual system.

The human visual system can extract 3-D shape information of unfamiliar moving objects from their projected transformations. Computational studies of this capacity have established that 3-D shape, can be extracted correctly from a brief presentation, provided that the moving objects are rigid. The human visual system requires a longer temporal extension, but it can cope, however, with considerable deviations from rigidity. It is shown how the 3-D structure of rigid and non-rigid objects can be recovered by maintaining an internal model of the viewed object and modifying it at each instant by the minimal non-rigid change that is sufficient to account for the observed transformation. The results of applying this incremental rigidity scheme to rigid and non-rigid objects in motion are described and compared with human perceptions.

Title: Yes, but… - How changes in banks in Västerbotten are linked to the current financial crisis, but are still normal organizational development Background: In the beginning of the 90’s, there was a financial crisis in Sweden which hit Swedish banks hard. The Swedish bank Gota banken went bankrupt and Nordbanken was taken over by the government, in large part because of their apathetic reactions to the situation they were so surprised to find themselves in. Today, almost 20 years later, the banks of Sweden find themselves in a new crisis. Because of the important position banks have in society, it is extremely important that they remain stable and have the capacity to ride out a crisis situation comfortably. As the banks did not show any crisis management strategy or skills in the 1992 crisis, it is relevant to explore if the previous experience has given Swedish banks the ability to handle a crisis situation in an efficient way. Purpose: The purpose of this study is to apply organizational development theory, crisis management theory and adversity reaction theory to the primary data collected from the interviews with the banks and through that analyze if Swedish banks are acting to prevent the financial crisis from affecting them badly. Method: The study has a hermeneutical approach and was carried out by interviewing managers from the five major banks in Västerbotten. The primary data collected has been analyzed to get an understanding of the current development in the banks and its possible link to the financial crisis. Conclusion: We found that banks are constantly changing in order to keep up with their competitors, changes in technology, society and the increasing demands from customers. The current events and changes in the banks are undoubtedly linked to the financial crisis, it has accelerated change, it has slowed down ongoing processes and it has facilitated harder decisions and less popular changes. But the crisis has not caused drastic changes in the organizations or their way of doing business. In fact, it can be said that the changes due to the financial crisis is normal organizational development, as the banks have responded to it in much the same fashion as they do to all changes in the external environment. Key words: crisis management, organizational development, threat rigidity, prospect theory, financial crisis

Conformational selection is the idea that proteins traverse positions on the conformational space represented by their potential energy landscape, and in particular positions considered as local energy minima. Conformational selection a useful concept in ligand binding studies and in exploring the behavior of protein structures within that energy landscape. Often, research that explores protein function requires the generation of conformational ensembles, or collections of protein conformations from a single structure. We describe a method of conformational ensemble generation that uses joint-constrained rigid-body dynamics (an approach that allows for explicit consideration of rigidity) and the elastic network model (providing structurally derived directional guides for the rigid-body model). We test our model on a selection of unbound proteins and examine the structural validity of the resulting ensembles, as well as the ability of such an approach to generate conformations with structural overlaps close to the ligand-bound versions of the proteins.

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This dissertation consists of three empirical essays on distortions in labor market outcomes in developing countries. Chapter 1 tests for downward nominal wage rigidity in markets for casual daily agricultural labor. It examines responses to rainfall shocks in 500 Indian districts from 1956-2008. First, nominal wages rise in response to positive shocks but do not fall during droughts. Second, after transitory positive shocks have dissipated, nominal wages do not fall back down. Third, inflation moderates these effects. Fourth, rigidities lower employment: landless laborers experience a 6% reduction in employment in the year after positive shocks. Fifth, consistent with separation failures, rationing leads to increased labor supply to small farms. New survey evidence suggests that agricultural workers and employers view nominal wage cuts as unfair and believe that they reduce effort. Chapter 2 (with Michael Kremer and Sendhil Mullainathan) describes the results of a field experiment that tests for self-control problems in labor supply. First, we find that workers will choose dominated contracts—which pay less for every output level but have a steeper slope—to motivate themselves. Second, effort increases significantly as workers’ (randomly assigned) payday gets closer. Third, the demand for dominated contracts (and their benefits) is concentrated amongst those with the highest payday effects. Finally, as workers gain experience, they appear to learn about their self control problems: the correlation between the payday effect and the demand for the dominated contract grows with experience. These results together suggest that self-control, in this context at least, meaningfully alters the firm’s contracting problem. Chapter 3 empirically examines the impact of multiple market failures on allocative efficiency in farm production in poor countries. In years when labor rationing is more likely in villages (due to wage rigidity), there is a 63% increase in sharecropped and leased land by small farmers. This is consistent with the prediction that distortions from a failure in one market can be reduced by reallocating other factors of production. In areas with worse credit access, there is less land adjustment in response to labor rationing. These results provide evidence for separation failures resulting from multiple missing markets.

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Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban University of Technology, 2009. / Through the literature review it has become apparent that low back pain is a very real problem in most societies. It has been suggested that there is enough evidence to prove the relationship between low back pain and local muscle dysfunction and that focus in management of these patients should be the rehabilitation of these muscles by exercise. Literature suggests that optimal core muscle strength, control and endurance working synergistically with the rest of the neuromusculoskeletal system is necessary for lumbar spine stability . Arthrogenic Muscle Inhibition is caused by distension and/or damage of a joint and is thought to disable the muscle from contracting all its muscle fibres. When a joint is injured it is thought that AMI causes muscle weakness, which in turn hampers the rehabilitation process of that joint despite complete muscle integrity. Spinal manipulative therapy has been shown to alter the excitability of spinal muscle motor neurons due to the stimulation of mechanoreceptors in the joint capsules suggesting that SMT could be a means to remove this inhibitory action. The literature supports the hypothesis that a decrease in the neurological deficit caused by AMI may result in a faster recovery rate. Aims The aim of this study is to determine the immediate effect of thoraco-lumbar spinal manipulation compared to lower lumbar spinal manipulation on core muscle endurance and activity in patients with mechanical low back pain by assessing the correlation between the objective and subjective measures. Method A prospective, convenience sample with purpose allocation (pre /post) clinical trial was used as the sampling method. Thirty participants where placed in two groups, group one and group two, of fifteen people each. Group one underwent spinal v manipulative therapy between L4 and S1 spinal levels. Group two underwent spinal manipulative therapy in between T8 and L1 spinal levels. The objective and subjective testing was done pre- and post-intervention. The objective data was that of a surface EMG attached bilaterally over the internal oblique as well as a prone abdominal draw in biofeedback test. The subjective data included a pain numerical rating scale (0-100). Results The results showed to partially favour group two (thoraco-lumbar), in both increased endurance time that would prove that AMI does in fact inhibit the transversus abdominis and obliques internus, thus it would hinder the rehabilitative process. Some of the statistics where not in favour of the aims, as there was no difference in the effect of group one or two on the NRS, as both improved consistently. It would be recommended that use be made of fine-wire EMG for testing the activity in both the obliques internus and the transversus abdominis, which would allow for more consistent readings, thus adding strength to the research.

<p>Anorexia nervosa (AN) is a dangerous disorder characterized by unrelenting rigidity that continues even in the presence of deadly outcomes. Despite this, our understanding of factors that promote and maintain rigidity is lacking. The current paper proposes a model suggesting that rigid behaviors in AN can be formulated as maladaptive rule-governed behavior that emerges in contexts of uncertainty and loss of control, such as in the presence of affective arousal. An empirical study examining the differences between individuals weight recovered from AN (AN-WR) and healthy controls (CN) on parameters of rule-governed behavior in neutral and stressful contexts is described. Seventy-four adults (AN-WR: 36; CN: 38) were randomized to undergo either a stressful or neutral mood manipulation and then completed a laboratory assessment of rule-governed behavior, along with questionnaires measuring difficulties with uncertainty. While the AN-WR group demonstrated greater flexibility in rule implementation compared to the CN group, they evidenced greater impairment in behavioral extinction. Furthermore, although affective arousal did not significantly impact rule-governed behavior as expected, difficulties tolerating uncertainty were significantly related to rule-governed outcomes exclusively in the AN-WR group. Taken together, findings provide preliminary support for maladaptive rule-governed behavior in AN and suggest that this is related to an intolerance of uncertainty. Findings and treatment implications are discussed in light of study limitations.</p> / Dissertation

Adapting to change in a constantly changing environment is a challenge that organisations face on a daily basis. In order to stay competitive globally, the management of resistance to change becomes crucial. Research done on leadership reveals the very strong effect that leaders have on followers’ behaviours and attitudes and it is emphasized the role leadership plays in the implementation and supporting of change. The purpose of this dissertation is to determine whether a relationship between leadership and resistance to change exist within the higher education sector. The study obtains data of 75 participants within the faculty of engineering. The survey was done by means of a questionnaire. The statistical analyses included frequency analysis, descriptive statistics, reliability analysis, correlations, independent t-tests, Mann-Whitney tests, ANOVAs and Kruskal-Wallis tests. Results indicated that employees’ reactions toward change could be influenced by the type of leadership style present in the organisation, therefore it is necessary that the correct leadership style within an organisation cannot be underestimated. It could mean the difference between success and failure. For the purpose of this study, the researcher considered the scales of the Resistance to Change questionnaire sufficiently reliable, but further exploration of the scales and its adaptation to this context may be needed in future to enhance reliability measures. An important insight of this research is that, to be more effective in creating and supporting change within organisations, managers need to learn to recognise and understand resistance within them as well as in others. This research contributes to the already vast content of research on leadership and resistance to change and does so by being focused on studying these constructs under a unique set of circumstances. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013