<p>Excess excitation energy, mechanical injury and defence against pathogens, each trigger rapid production of reactive oxygen species (ROS) in <i>Arabidopsis thaliana</i> leaves. ROS, such as hydrogen peroxide (H₂O₂), are required for the induction of systemic acquired acclimation and may lead to redox changes in photosynthetic electron transport (PET). On one hand, enhanced ROS production during stress can destroy cells, and on the other, ROS can also act as signals for the activation of stress responsive and defensive pathways.</p><p>In this work, physiological and molecular analyses of <i>Arabidopsis</i> mutants and transgenic lines were applied to investigate the signalling network controlling biotic and abiotic stress responses. A key enzyme of the antioxidant network is encoded by <i>ASCORBATE PEROXIDASE 2 (APX2</i>). Wounded leaves showed low induction of<i> APX2 </i>expression and when exposed to excess light, <i>APX2</i> expression was increased synergistically. Signalling pathways dependent upon jasmonic acid, chitosan and abscisic acid were not involved in the wound-induced expression of <i>APX2</i>, but PET was required, and APX2 induction was preceded by a depressed rate of CO₂fixation.</p><p>Analysis of<i> lsd1</i> (<i>LESION SIMULATING DISEASE 1</i>) strongly suggests that light acclimatory processes and pathogen defences are genetically and functionally linked. It is important to know that LSD1 type of mutants have mainly been studied with regard to pathogenesis. From this work, it reveals that association of LSD1 with hypersensitive response may only be supplementary.</p><p><i>GLUTATHIONE PEROXIDASES</i> <i>(GPXs)</i> are another major family of ROS scavenging enzymes. Analysis of the <i>Arabidopsis </i>genome database revealed a new open-reading frame, thus increasing the total number of <i>AtGPX </i>gene family to eight (<i>AtGPX1-AtGPX8</i>). <i>Arabidopsis thaliana</i> transgenic lines with reduced expression of both putative chloroplastic isoforms (<i>AtGPX1 </i>and <i>AtGPX7</i>) and <i>AtGPX7</i> knock-out mutant (ko-<i>GPX7</i>) were more sensitive to photo-oxidative stress but had a reduced bacterial growth rate when inoculated with virulent strains <i>Pseudomonas syringae</i> pv. <i>tomato</i> DC3000 and<i> P.s.t. maculicola</i> strain ES4326, indicating increased resistance to pathogenesis. This, to our knowledge, is the first functional and genetic analysis of chloroplastic GPXs in plants, and confirms that light and chloroplastic ROS metabolism is important for basal resistance against virulent pathogens.</p><p>The above results confirm that light sensing, light acclimatory processes and photo-produced ROS also govern pathogen defence pathways. This has a great ecological relevance for Darwinian fitness of plants growing in the natural environment, where simultaneous pathogen attack and fluctuations in light, temperature and other environmental factors make rapid acclimation a constant necessity. Molecular, biochemical and physiological analysis of pathogen responses in mutants impaired in light sensing, EEE-dissipatory mechanisms, and similar analysis of light acclimatory processes in mutants impaired in pathogen defences may prove to be seminal.</p>

<p>In the natural environment plants are confronted to a multitude of biotic and abiotic stress factors that must be perceived, transduced, integrated and signaled in order to achieve a successful acclimation that will secure survival and reproduction. Plants have to deal with excess excitation energy (EEE) when the amount of absorbed light energy is exceeding that needed for photosynthetic CO2 assimilation. EEE results in ROS formation and can be enhanced in low light intensities by changes in other environmental factors.</p><p>The lesions simulating disease resistance (lsd1) mutant of Arabidopsis spontaneously initiates spreading lesions paralleled by ROS production in long day photoperiod and after application of salicylic acid (SA) and SA-analogues that trigger systemic acquired resistance (SAR). Moreover, the mutant fails to limit the boundaries of hypersensitive cell death (HR) after avirulent pathogen infection giving rise to the runaway cell death (rcd) phenotype. This ROS-dependent phenotype pointed towards a putative involvement of the ROS produced during photosynthesis in the initiation and spreading of the lesions.</p><p>We report here that the rcd has a ROS-concentration dependent phenotype and that the light-triggered rcd is depending on the redox-state of the PQ pool in the chloroplast. Moreover, the lower stomatal conductance and catalase activity in the mutant suggested LSD1 was required for optimal gas exchange and ROS scavenging during EEE. Through this regulation, LSD1 can influence the effectiveness of photorespiration in dissipating EEE. Moreover, low and high SA levels are strictly correlated to lower and higher foliar H2O2 content, respectively. This implies an essential role of SA in regulating the redox homeostasis of the cell and suggests that SA could trigger rcd in lsd1 by inducing H2O2 production.</p><p>LSD1 has been postulated to be a negative regulator of cell death acting as a ROS rheostat. Above a certain threshold, the pro-death pathway would operate leading to PCD. Our data suggest that LSD1 may be subjected to a turnover, enhanced in an oxidizing milieu and slowed down in a reducing environment that could reflect this ROS rheostat property. Finally, the two protein disulphide isomerase boxes (CGHC) present in the protein and the down regulation of the NADPH thioredoxin reductase (NTR) in the mutant connect the rcd to a putative impairment in the reduction of the cytosolic thioredoxin system. We propose that LSD1 suppresses the cell death processes through its control of the oxidation-reduction state of the TRX pool. An integrated model considers the role of LSD1 in both light acclimatory processes and in restricting pathogen-induced cell death.</p>

L'objectif de ce travail est de contribuer expérimentalement au développement d'un modèle de film liquide pour l'automobile. Nous présentons ici des expériences modèles d'écoulement de gouttes et films liquides dans des conditions de cisaillement et de gravité rencontrées dans l'industrie. Le ruissellement d'un film d'eau ou de gouttes de pluie sur un pare-brise est un phénomène important dans un contexte de sécurité des véhicules. Nous décrivons dans une première partie une expérience modèle de drainage d'un film liquide sur un plan incliné soumis à un contre-courant d'air. Cette expérience nous a conduit à développer une technique expérimentale permettant de visualiser facilement le profil d'épaisseur des films. Nous avons contribué à la caractérisation de l'écoulement du film par gravité en mettant en évidence différents régimes de développement d'ondes. Le contre-courant d'air s'oppose au drainage par gravité ; nous caractérisons le seuil en vitesse de vent qui permet au film liquide de faire marche arrière par entraînement aéraulique. Un tel film est souvent instable du point de vue du mouillage et se fragmente en gouttes et ruisselets. Nous nous intéressons dans une seconde partie au déplacement de gouttes sous l'effet du vent. Nous observons que ces gouttes ne commencent à se déplacer qu'à partir d'un certain seuil lié à l'hystérésis de l'angle de contact du liquide sur le solide. Au delà de ce seuil, la vitesse de la goutte augmente avec la vitesse du vent. Sa dynamique peut être décrite à partir d'un trio de nombres sans dimension qui tient compte des forces capillaires, visqueuses, aérodynamiques et du poids. Nous avons mis en évidence une recirculation contre-intuitive à l'intérieur de la goutte et l'avons quantifiée. Nous nous sommes enfin intéressés aux variations de la forme de la goutte sous l'effet du vent et aux interactions entre gouttes voisines.

<p>The media has responded toward unethical behavior in rainforests during the ‘80’s, triggering</p><p>the still upcoming trend of investigation of ethical considerations, as described by Macfarlane</p><p>(1995). Many researchers are constantly improving the ethical theories and showing</p><p>continued change in the perception of ethics (Svensson & Wood, 2007)</p><p>The purpose of this research is to identify the effect of ethics on the proactive or reactive</p><p>behavior of companies, with a downward tendency provided in the value chain.</p><p>The theoretical framework consists out of a set of theories supporting the goal of identifying</p><p>ethics within a company, applying a new business ethics model and measuring the pro-active</p><p>and re-active behavior of the stakeholder in the value chain. Finally, all the theories used, are</p><p>combined in an integrated theoretical model used to justify the collection of empirical data</p><p>and to give structure to the analysis.</p><p>The empirical data has been gathered through non structured and semi-structured interviews</p><p>with customers, employees within the case company, and a supplier to the case company.</p><p>These findings are complemented with secondary data gathered through websites, annual</p><p>reports, codes of conduct, media articles and others sources.</p><p>The findings of the study showed that the (in the theoretical framework) assumption of a</p><p>downward effect in perception and change in ethical considerations is not as obvious as</p><p>previously thought. Within this case study, the ethical influences come from the case</p><p>company, situated in the middle of the value chain, influencing both the consumer and the</p><p>supplier, in ethical considerations.</p>

<p>Tiny Timber is a very lightweight, real-time kernel for small, event-driven embedded systems.  It implements reactive objects as a way of structuring embedded software. These objects are components that react to incoming events by updating their internal state and issuing an outgoing event. Implementing a control system based on reactive objects enhances the reactivity of the system and it helps to optimize the energy consumption, as the system goes to sleep mode when there is nothing to react to. It is also a programming technique that facilitates the organization of the program.</p><p>In this project, we develop a device driver for radio communication with a Tiny Timber interface. This is an extension to the Platform for Intelligent Embedded (PIE) system which is a robot assembled and used at the IDE department of Halmstad University as a platform for developing new applications as well as for educational purposes in the area of embedded and intelligent systems.  The interface is programmed in C and consists of a collection of device drivers for different components of PIE in the form of reactive objects.</p>

<p>The authors of this paper will try to identify what different pressure factors have an influence over the Swedish mechanical pulp and paper industry. Moreover, the authors of this paper will try to identify whether different levels of environmental commitment can be identified within the organization.</p><p>The results show that all of the pressure factors that were identified in the case study, except for regulations and social pressure, are influenced by economic benefits and, therefore, a reactive stance is almost always preferred by the firm when there is a negative correlation between economic performance and environmental performance. Results also indicate a gap in the internal communication of the organization. This is not related to the topic of this paper but might be useful information for the company used in the case study.</p>

<p><strong>Background:</strong> The reasons why this study is conducted is because of the latest recession in the global economy. The current recession has made a lot of companies more aware of its cost, and in order to fit the new harsher economic climate the companies has to be more cost efficient. In order to do so many companies choose to reduce their amount of employees. When this happens in a recession, most of the layoffs are an effect of reactive causes, such as lower incoming orders, and fewer customers. This leads to a problem for the companies that don’t know how these kinds of layoffs will affect the value of the company’s stock. This leads to a question whether there is a significant pattern between layoffs that are a result of reactive reasons and the number of employees that are being laid off, in percentage of the total number of employees of the companies in question?</p><p><strong>Purpose:</strong> The reason for this study is to find out if there is any correlation between how many employees that is laid off, in percentage of the company’s total employees, and if different percentages have different impact in the valuations of the company’s stock.</p><p><strong>Approach:</strong> This study is made in the form of a modified event study and narrows down to the recession during 2008-01-01 to 2009-10-01, and only involves companies that are on trade on the stock market in Stockholm Sweden. The objects that are involved in this study are from the stock markets large and mid-cap sections. The criteria for companies in this study are that they should have made layoffs for reactive reasons in the time period that we are interested in. The variations in the company’s stock are compared to Stockholm’s stock markets OMX-index. The information needed to conduct this study is gathered from press realises and from financial reports made by the companies.</p><p><strong>Result and conclusions:</strong> The study shows that there is a correlation between how large percentage of the company’s total employees that are laid off and the effect of variations in the stock. The correlation is -0,306 but it is not statistical verified. This result was not in line with our hypotheses that we had concluded from earlier research and theories that are in the study. Earlier research on the American stock market shows a stronger connection between large percentage layoffs and how this makes the stock value to decrease.</p>

<p>The interplay between hydraulic and chemical processes in streams and adjacent storage zones, e.g. streambed sediments, is of crucial importance for the large-scale transport of released contaminants. This thesis presents a methodology for tracer experiments and the development of mechanistic transport models. </p><p>We conducted four field tracer experiments with the reactive tracer chromium, ⁵¹Cr(III) and/or the conservative tracers potassium iodide (KI) and tritium (³H₂O), along 11 km of the Lanna Stream in Skara County, Sweden, and along a 30 km reach of the Säva Stream in Uppland County, Sweden. The field monitoring included sampling of tracer in the surface water as well as in the streambed sediments. A simultaneous injection of tritium and chromium facilitated an independent evaluation of the hydraulic transport into and out of the sub-surface storage zones. The difference in transport behaviour between the two tracers, were attributed to chemical reactivity.</p><p>In terms of idealised transport models we found that the reactivity of chromium could be characterised by simple chemical concepts. The local equilibrium assumption (LEA), the irreversible kinetics assumption (IKA) and the reversible kinetics assumption (RKA) were applied in the experimental evaluations. An independent evaluation of the streambed transport revealed that the impact of reaction kinetics was substantial. Model calculations and results from a chemical extraction procedure indicated that the chemical reactions affecting the chromium transport were to some extent irreversible.</p><p>This thesis presents a number of exact analytical solutions to the governing partial differential equations. The main theoretical contribution is the incorporation of variable coefficients for stream discharge and sediment porosity, which were measured in field.</p>

<p>Electro-acoustic devices such as surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices have been in commercial use for over 60 years and can be found in applications ranging from specialised scientific and military equipment to consumer products, such as mobile telephones, TV and radio receivers, etc. Today by far the largest market for electro-acoustic devices is the telecommunication industry which annually consumes approximately three billion acoustic wave filters for frequency control alone.</p><p>The development of new materials and technologies for electro-acoustic devices has gained a substantial and growing interest from both academic and industrial research communities in recent years due to the enormous growth in the telecommunication industry and other forms of wireless data communication. One of the bigger issues has been to replace the single crystalline substrates with thin film piezoelectric materials deposited by reactive sputtering. This would not only reduce the manufacturing costs but will also enable high frequency of operation and a wider choice of substrate materials. However, in order to obtain the material properties required for the intended application a detailed theoretical description of the reactive sputtering process is necessary since the texture and other functional properties of the piezoelectric material are extremely sensitive to the process parameters in addition to the structure of the underlying material.</p><p>This thesis studies the reactive sputtering process and its application for the fabrication of thin film electro-acoustic devices. The aim has been to gain a further insight into the process and make use of this knowledge to improve the fabrication of electro-acoustic devices. In this work modelling of the reactive sputtering process has been improved by studying certain fundamental aspects of the process and in particular the dynamics of the processes taking place during sputtering both at the target and the substrate surfaces. Consequently, highly textured thin piezoelectric aluminium nitride films have been synthesized and thin film bulk acoustic resonators (FBAR) operating in the GHz range have been fabricated and studied.</p>

Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007.