Phonon effects in molecular transistors: Quantum and classical treatment

We present a comprehensive theoretical treatment of the effect of electron-phonon interactions in molecular transistors, including both quantal and classical limits and we study both equilibrated and out of equilibrium phonons. We present detailed results for conductance, noise and phonon distribution in two regimes. One involves temperatures large as compared to the rate of electronic transitions on and off the dot; in this limit our approach yields classical rate equations, which are solved numerically for a wide range of parameters. The other regime is that of low temperatures and weak electron-phonon coupling where a perturbative approximation in the Keldysh formulation can be applied. The interplay between the phonon-induced renormalization of the density of states on the quantum dot and the phonon-induced renormalization of the dot-lead coupling is found to be important. Whether or not the phonons are able to equilibrate in a time rapid compared to the transit time of an electron through the dot is found to affect the conductance. Observable signatures of phonon equilibration are presented. We also discuss the nature of the low-T to high-T crossover.Comment: 20 pages, 19 figures. Minor changes, version accepted for publication in Phys. Rev.

The charismatic leadership of the ECB presidency:A language-based analysis

There is little doubt that the European Central Bank (ECB), and in particular its presidency, has taken the lead in tackling the euro crisis. But can this leadership be also characterised as charismatic? This article answers the question by focusing on language – a key component as well as a reliable indicator of charisma. By means of a software‐assisted content analysis of the entire corpus of ECB presidential speeches, it is found that the crisis has indeed led to the emergence of the Bank's presidency as a charismatic euro leader. This in turn confirms the recent politicisation of the ECB, but at the same time might be seen as mitigating the problems related to the Bank's democratic deficit, to the extent that charisma can be seen, from a Weberian standpoint, as an alternative source of political legitimacy

Preventing and treating dehydration in the elderly during periods of illness and warm weather.

Item does not contain fulltextOBJECTIVE: Translate the available knowledge on ageing and dehydration into main messages for clinical practice. MAIN POINTS: Older people are more susceptible to dehydration than younger people. This is partly due to lack of thirst sensation and changes in the water and sodium balance that naturally occur as people age. It is also, to some degree, attributable to the fact that elderly people, both those living at home and those living in institutions, often have various impairments, disabilities and/or handicaps (comorbidity). They also tend to use numerous drugs and medication for these illnesses (polypharmacy). Multimorbidity and polypharmacy often overstress the normal age-related physiological changes in the water and sodium balance and therefore increase elderly people's risk of dehydration,especially during intercurrent infections or warm weather. Elderly people, whether they are living on their own or in an institution, and especially elderly people that can no longer take care of themselves because of cognitive, sensory, motor and/or ADL impairments, need extra help to stay hydrated. The most important strategy is simply a matter of ensuring that elderly people consume a sufficient amount of fluids (at least 1.7 liters every 24 hours). Additional strategies include making healthy drinks and water easily available and accessible at all times and reminding and encouraging the elderly to consume these fluids. Elderly people should not be encouraged to consume large amounts of fluids at once but rather small amounts throughout the day. When the recommended fluid intake cannot, for whatever reason, be realized, fluids can be administered via catheter or by hypodermoclysis. In more specific and severe cases, fluids can be administered intravenously. CONCLUSION: The prevention, signaling and treatment of dehydration in the elderly is an important multidisciplinary endeavor. Formal and informal care providers need to continuously be aware of the risk factors and signs of dehydration in the elderly, especially during periods of very warm weather and when older people are ill. Standard professional care for high risk patients is imperative