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

Konsum und Vermögen : Eine quantitative Analyse für Deutschland

Die Studie folgt der Lebenszyklushypothese nach Modigliani und untersucht die Einflüsse von privatem Einkommen und Vermögen auf den privaten Konsum. Es werden Daten für das wiedervereinigte Deutschland von 1991 bis 2002 verwendet. Die Ergebnisse der linearen Regressionen zeigen eine starke positive Abhängigkeit des Konsums vom Einkommen. Die in der Literatur dargestellte Beziehung mit dem Vermögen kann jedoch nicht bestätigt werden. Die Analyse mit Fehlerkorrekturmodellen führt allerdings zu modifizierten Ergebnissen. Zunächst wird die Existenz von nichtsaisonalen Einheitswurzeln bestätigt, die von saisonalen jedoch abgelehnt, sodaß dann die Schätzung den Einfluß beider Variablen auf den Konsum nachweist. -- The study follows Modiglianis ?Life Cycle Hypothesis? and surveys the influence of private income and wealth to private consumption. Dealing with data for the unified Germany from 1991 to 2002 linear regressions indicate a strong positive relationship between consumption and income. The dependency from wealth, which is presented in the literature, cannot be confirmed. Analysis with error-correction-models leads to a different result. First evidence is found for nonseasonally, but not for seasonally integrated relations: This estimation shows the influence of both variables, income and wealth, on consumption.

Microstructured blood vessel surrogates reveal structural tropism of motile malaria parasites

Plasmodium sporozoites, the highly motile forms of the malaria parasite, are transmitted naturally by mosquitoes and traverse the skin to find, associate with, and enter blood capillaries. Research aimed at understanding how sporozoites select blood vessels is hampered by the lack of a suitable experimental system. Arrays of uniform cylindrical pillars can be used to study small cells moving in controlled environments. Here, an array system displaying a variety of pillars with different diameters and shapes is developed in order to investigate how Plasmodium sporozoites associate to the pillars as blood vessel surrogates. Investigating the association of sporozoites to pillars in arrays displaying pillars of different diameters reveals that the crescent-shaped parasites prefer to associate with and migrate around pillars with a similar curvature. This suggests that after transmission by a mosquito, malaria parasites may use a structural tropism to recognize blood capillaries in the dermis in order to gain access to the blood stream

Bound States in Sharply Bent Waveguides: Analytical and Experimental Approach

Quantum wires and electromagnetic waveguides possess common features since their physics is described by the same wave equation. We exploit this analogy to investigate experimentally with microwave waveguides and theoretically with the help of an effective potential approach the occurrence of bound states in sharply bent quantum wires. In particular, we compute the bound states, study the features of the transition from a bound to an unbound state caused by the variation of the bending angle and determine the critical bending angles at which such a transition takes place. The predictions are confirmed by calculations based on a conventional numerical method as well as experimental measurements of the spectra and electric field intensity distributions of electromagnetic waveguides

Conjugating effects of symbionts and environmental factors on gene expression in deep-sea hydrothermal vent mussels.

International audienceABSTRACT: BACKGROUND: The deep-sea hydrothermal vent mussel Bathymodiolus azoricus harbors thiotrophic and methanotrophic symbiotic bacteria in its gills. While the symbiotic relationship between this hydrothermal mussel and these chemoautotrophic bacteria has been described, the molecular processes involved in the cross-talking between symbionts and host, in the maintenance of the symbiois, in the influence of environmental parameters on gene expression, and in transcriptome variation across individuals remain poorly understood. In an attempt to understand how, and to what extent, this double symbiosis affects host gene expression, we used a transcriptomic approach to identify genes potentially regulated by symbiont characteristics, environmental conditions or both. This study was done on mussels from two contrasting populations. RESULTS: Subtractive libraries allowed the identification of about 1000 genes putatively regulated by symbiosis and/or environmental factors. Microarray analysis showed that 120 genes (3.5% of all genes) were differentially expressed between the Menez Gwen (MG) and Rainbow (Rb) vent fields. The total number of regulated genes in mussels harboring a high versus a low symbiont content did not differ significantly. With regard to the impact of symbiont content, only 1% of all genes were regulated by thiotrophic (SOX) and methanotrophic (MOX) bacteria content in MG mussels whereas 5.6% were regulated in mussels collected at Rb. MOX symbionts also impacted a higher proportion of genes than SOX in both vent fields. When host transcriptome expression was analyzed with respect to symbiont gene expression, it was related to symbiont quantity in each field. CONCLUSIONS: Our study has produced a preliminary description of a transcriptomic response in a hydrothermal vent mussel host of both thiotrophic and methanotrophic symbiotic bacteria. This model can help to identify genes involved in the maintenance of symbiosis or regulated by environmental parameters. Our results provide evidence of symbiont effect on transcriptome regulation, with differences related to type of symbiont, even though the relative percentage of genes involved remains limited. Differences observed between the vent site indicate that environment strongly influences transcriptome regulation and impacts both activity and relative abundance of each symbiont. Among all these genes, those participating in recognition, the immune system, oxidative stress, and energy metabolism constitute new promising targets for extended studies on symbiosis and the effect of environmental parameters on the symbiotic relationships in B. azoricus

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

Measurements of single top quark production cross sections and |Vtb| in ppbar collisions at sqrt{s}=1.96 TeV

We present measurements of production cross sections of single top quarks in \ppbar collisions at $\sqrt{s}=1.96\;\rm TeV$ in a data sample corresponding to an integrated luminosity of $5.4\;\rm fb^{-1}$ collected by the D0 detector at the Fermilab Tevatron Collider. We select events with an isolated electron or muon, an imbalance in transverse energy, and two, three, or four jets, with one or two of them containing a bottom hadron. We obtain an inclusive cross section of \sigma({\ppbar}{\rargap}tb+X, tqb+X) = 3.43\pm^{0.73}_{0.74}\;\rm pb and use it to extract the CKM matrix element $0.79 < |V_{tb}| \leq 1$ at the 95% C.L. We also measure \sigma({\ppbar}{\rargap}tb+X) = 0.68\pm^{0.38}_{0.35}\;\rm pb and \sigma({\ppbar}{\rargap}tqb+X) = 2.86\pm^{0.69}_{0.63}\;\rm pb when assuming, respectively, $tqb$ and $tb$ production rates as predicted by the standard model.Comment: 11 pages, 8 figures, submitted to Phys. Rev.