Search for new physics in top events with the D0 detector

This review is focused on the search for new processes, performed with top quark events in D{\O}. It presents four updated or new D{\O} results. The two first analyses deal with top production properties: they search for a new heavy resonance decaying to top-antitop. The two last results concern top decay properties: the measurement of the $W$ helicity as a probe of the $tWb$ coupling structure, and the top quark branching ratio to $Wb$. Neither of these measurements reveal any deviation with respect to the standard model predictions.Comment: Submitted for the SUSY07 conference proceeding. 4 pages, LateX, 6 eps figures, 2 LateX style file

Modeling Time-dependent CO2_2 Intensities in Multi-modal Energy Systems with Storage

CO$_2$ emission reduction and increasing volatile renewable energy generation mandate stronger energy sector coupling and the use of energy storage. In such multi-modal energy systems, it is challenging to determine the effect of an individual player's consumption pattern onto overall CO$_2$ emissions. This, however, is often important to evaluate the suitability of local CO$_2$ reduction measures. Due to renewables' volatility, the traditional approach of using annual average CO$_2$ intensities per energy form is no longer accurate, but the time of consumption should be considered. Moreover, CO$_2$ intensities are highly coupled over time and different energy forms due to sector coupling and energy storage. We introduce and compare two novel methods for computing time-dependent CO$_2$ intensities, that address different objectives: the first method determines CO$_2$ intensities of the energy system as is. The second method analyzes how overall CO$_2$ emissions would change in response to infinitesimal demand changes. Given a digital twin of the energy system in form of a linear program, we show how to compute these sensitivities very efficiently. We present the results of both methods for two simulated test energy systems and discuss their different implications.Comment: This work has been submitted to the Elsevier Applied Energy for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Yield-driven power-delay-optimal CMOS full-adder design complying with automotive product specifications of PVT variations and NBTI degradations

We present the detailed results of the application of mathematical optimization algorithms to transistor sizing in a full-adder cell design, to obtain the maximum expected fabrication yield. The approach takes into account all the fabrication process parameter variations specified in an industrial PDK, in addition to operating condition range and NBTI aging. The final design solutions present transistor sizing, which depart from intuitive transistor sizing criteria and show dramatic yield improvements, which have been verified by Monte Carlo SPICE analysis

Arms Trade and Military Expenditures in Eastern Europe

Four models are developed and tested in this study. The first two models deal with arms trade, and the other two deal with military expenditures. The most important finding of this study is political freedom has a very strong effect on both arms trade and military expenditures in Eastern Europe. The more free a country, the less likely it is to have high levels of arms trade overall, as well as import arms. Also, the higher the level of political freedom, the lower the value and intensity of military expenditures. All of the models were tested for Eastern Europe a whole as well as for the individual countries of Bulgaria, Czechoslovakia, East Germany, Hungary, Poland and Romania

Over the Aesop

Fairy tales and nursery rhymes hold a certain amount of nostalgia. As part of our childhood, these familiar characters are often left behind while we grow and mature. Their stories are frozen in time and shown to the next generation in the same way they were introduced to us. True characters evolve over time, this is how they stay relevant to changing times. These well rounded characters are what make the art of storytelling exciting. It is important to me to be able to intertwine the traditional characters with a more modern appearance. For this body of work my goal was to create a visual narrative that incorporated traditional fairy tale and nursery rhyme characters with a pop culture story line, while injecting references to more modern styles and trends along with some humor. The original story that this narrative is built on is Aesop’s Fable; the Tortoise and the Hare. Once this was established as the base, I combined it with the traditional 80’s overcoming the odds formula by referencingOver the Top. The Hare, after losing to the Tortoise has no other option than to redeem himself through competitive arm wrestling. These two stories mixed together needed a strong supporting cast of colorful characters and environments in which to grow and thrive. Each character is placed in their own personalized environment filled with symbolism so that when drawn into the large narrative they are not just a blank faced extra taking up space in the background. The hidden references throughout all of the pieces pay homage to the age old tradition of storytelling. These small nods to different author’s approaches to the stories are important to me as an artist. We cannot progress forward without knowing and honoring where we have been. The whole time the environments and characters help build the excitement around the approaching rematch

Analysis of the Wnt receptors Ror, Otk and Otk2 during nervous system development in Drosophila melanogaster

Wnt signaling regulates many developmental and adult physiological processes. This is achieved through the activation of several distinct Wnt pathways. The outcome is determined by a specific combination of a Wnt ligand and one or several Wnt receptors. Ror receptor tyrosine kinases are Wnt receptors, which function in many developmental processes. So far, no phenotypic or functional data for the Drosophila Ror family member were available. Using a fly line expressing Ror-eGFP under the endogenous promoter, we could show that Drosophila Ror is expressed in the nervous system. The expression commences after germ band retraction and persists throughout embryonic development within the ventral nerve cord and the brain. It can also be observed in the sensory organs of the PNS. In the larval CNS it is visible in the membrane of all neuronal cells and in larval imaginal discs it can be observed in distinct cell clusters possibly representing proneuronal clusters. Embryos mutant for Ror display a mild CNS defect. A number of embryos in which the two PTK7 homologs (Otk and Otk2) were removed as well, display an even stronger CNS phenotype and increased larval lethality.  Ror genetically interacts with Wnt5 and is able to bind to Wg, Wnt2, Wnt4, as well as to the receptors Fz, Fz2, Otk and Otk2. To identify downstream targets of Ror/Otk/Otk2-signaling, we performed a transcriptome analysis and compared differentially expressed genes in the respective single, double and triple mutants. We have identified various differentially expressed genes including several transcription factors and proteins involved in nervous system development. Future analyses of these will enable us to define the functions of Ror, Otk and Otk2 during Drosophila development

The role of the myosin motor and environmental factors in Plasmodium gliding motility

Cell migration of Plasmodium parasites, the causative agents of malaria, is powered by an actomyosin motor. This substrate-dependent type of movement termed gliding motility is important at different stages throughout the complex life cycle of these parasites and is required to traverse tissues and invade host cells. The motor complex is located beneath the plasma membrane and consists of anchored myosin A proteins that exert forces on actin filaments which can be transmitted to a substrate by transmembrane proteins. How the surrounding environment impacts parasite motility is not fully understood. Furthermore, it is unclear how the actomyosin motor can be modulated to allow for stage-specific regulation of parasite motility. In the first part of this study, I show how substrate elasticity, confinement and pore size affect Plasmodium motility using polyacrylamide hydrogels. I found that the parasites were not capable to move persistently on flat soft substrates, while the migratory capacity increased with substrate stiffness. In confined environments on the other hand parasites moved robustly even if the surrounding matrix was extremely soft. Plasmodium sporozoites, the stages transmitted into the dermis by a mosquito, could squeeze through the tiny pores of polyacrylamide hydrogels. This 3D hydrogel assay can be used as an in vitro model to test drugs or antibodies against the parasite after transmission. The second part of this thesis deals with the role of myosin A for Plasmodium gliding motility. Using a reverse genetic approach, I could demonstrate the importance of amino acids within the unusual N-terminal extension of myosin A for maximum speed of sporozoites in vitro. I found that phosphorylation of one of these residues is required for efficient salivary gland invasion of sporozoites in vivo. These results show for the first time, how modulation of motor properties by post-translational modification of myosin A could regulate parasite motility to allow for successful transmission from mosquito vector to mammalian host

Organized camp and character development

The purpose of this study was to examine the relationship between organized camp and character development. In particular, it looked to determine to what extent organized camp affected campers\u27 character, including how much change in character campers\u27 experienced in a week at camp, what aspects of character were most influenced, and what factors about camp had the most impact on campers\u27 character. The study was multimodal in design, using the Values in Action Inventory for Youth (VIA-Youth) as a pre and posttest for quantitative analysis and camper interviews, staff interviews, and researcher observations for qualitative analysis. Seven completed VIA-Youth pre and posttests were returned to the researcher, which made the quantitative data less valid than if more surveys had been returned. It was found that camp has a positive effect on campers across several virtue categories especially transcendence. In interviews, campers almost always had a positive attitude about the benefits of camp. Older campers tended to be able to more clearly articulate complex benefits of camp. Counselors were found to be a major factor influencing the campers\u27 experience of camp. The very structure and attitude of camp and how it is run was also highly influential on camper perceptions of camp. It was determined that, while based on the quantitative, camp had a positive effect on campers, the quantitative data was less clear because of the short time frame of a camp session as well as the nature of the survey instrument used