We define four 3×3 commuting contractions which do not dilate to commuting isometries. However they do satisfy the scalar von Neumann inequality. These matrices are all nilpotent of order 2. We also show that any three 3×3 commuting contractions which are scalar plus nilpotent of order 2 do dilate to commuting isometries.

The aim of this study was to verify the prevalence of physical inactivity and associated factors among adolescents commuting to school. This was an epidemiological study based on secondary data from a sample of 4,207 adolescents (14-19 years). Data were collected through a previously validated questionnaire (GSHS-WHO). Adolescents were classified as "inactive in commuting" when they reported no...

The study of quantum circuits composed of commuting gates is particularly useful to understand the delicate boundary between quantum and classical computation. Indeed, while being a restricted class, commuting circuits exhibit genuine quantum effects such as entanglement. In this paper we show that the computational power of commuting circuits exhibits a surprisingly rich structure. First we sh...

The World Trade Organization's Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) set global minimum standards for the protection of intellectual property, substantially increasing and expanding intellectual-property rights, and generated clear gains for the pharmaceutical industry and the developed world. The question of whether TRIPS generates gains for developing coun...

1 Autonomous vehicles (AVs) potentially increase vehicle travel by reducing travel and parking costs and by 2 providing improved mobility to those who are too young to drive or older people. The increase in vehicle travel 3 could be generated by both trip diversion from other modes and entirely new trips. Existing studies however tend 4 to overlook AVs’ impacts on entirely new trips. There is a...

BACKGROUND Bicycle commuting in an urban environment of high air pollution is known to be a potential health risk, especially for susceptible individuals. While risk management strategies aimed to reduce exposure to motorised traffic emissions have been suggested, only limited studies have assessed the utility of such strategies in real-world circumstances. OBJECTIVES The potential to lower e...

I n order to determine the type of transportation systems needed to accommodate a proposed shopping center development, an understanding of the characteristics of shopping trips is essential. Shopping trips are complicated for two reasons: first, because a proportion of trips made are a part of a series of linked trips; and second, because the trips have a vwiety of origins and destinations bef...

Commuting data is increasingly used to describe population mobility in epidemic models. However, there is little evidence that the spatial spread of observed epidemics agrees with commuting. Here, using data from 25 epidemics for influenza-like illness in France (ILI) as seen by the Sentinelles network, we show that commuting volume is highly correlated with the spread of ILI. Next, we provide ...

This paper analyzes the determinants of the perceived stress level of workers with a special focus on the effects of commuting, while controlling for personal and work-related characteristics. Using ordered logistic regression we find that several dimensions of the commuting situation, such as impedance, control and predictability of commuting, significantly influence the perceived stress level...