There is a certain family of conformally invariant first order elliptic systems which include the Dirac operator as its first and simplest member. Their general definition is given and some of their basic properties are described. A special attention is paid to the Rarita-Schwinger operator, the second simplest operator in the row. Its basic properties are described in more details. In the last...

OBJECTIVES To assess quality of reporting of sample size calculation, ascertain accuracy of calculations, and determine the relevance of assumptions made when calculating sample size in randomised controlled trials. DESIGN Review. DATA SOURCES We searched MEDLINE for all primary reports of two arm parallel group randomised controlled trials of superiority with a single primary outcome publi...

As the portion of coupling capacitance increases in smaller process geometries, accurate coupled noise analysis is becoming more important in current design methodologies. We propose a method to determine whether aggressors can potentially switch simultaneously with the victim or not. The functional information is used to classify the aggressors. Our functional pruning algorithm inspects the co...

All electrostimulation studies on arithmetic have so far solely reported general errors. Nonetheless, a classification of the errors during stimulation can inform us about underlying arithmetic processes. The present electrostimulation study was performed in a case of left parietal glioma. The patient's erroneous responses suggested that calculation was mainly applied for addition and a combina...

HIV prevalence has recently begun to decline in Zimbabwe, a result of both high levels of AIDS mortality and a reduction in incident infections. An important component in understanding the dynamics in HIV prevalence is knowledge of past trends in incidence, such as when incidence peaked and at what level. However, empirical measurements of incidence over an extended time period are not availabl...

BACKGROUND In spite of our extensive knowledge of the more than 20 proteins associated with different amyloid diseases, we do not know how amyloid toxicity occurs or how to block its action. Recent contradictory reports suggest that the fibrils and/or the oligomer precursors cause toxicity. An estimate of their temporal concentration may broaden understanding of the amyloid aggregation process....

The 2003 severe acute respiratory syndrome (SARS) epidemic was characterized by the occurrence of large clusterings (i.e. super-spreading events) of infections. Environmental factors were suspected to play significant roles in some of these large outbreaks. For determining the environmental factors, it is important to estimate the time of infection. Estimating the time of infection, an unobserv...

The United States Department of Agriculture Forest Service (USDAFS) has been involved in the development of computer models to simulate deposition from aerial pesticide spraying since the early 1970s. Originally, this work was driven by the need to improve the percentage of aerially sprayed material that actually deposited on a target area. The amount of on-target deposition is a primary factor...