Limits of quantum speedup in photosynthetic light harvesting

It has been suggested that excitation transport in photosynthetic light harvesting complexes features speedups analogous to those found in quantum algorithms. Here we compare the dynamics in these light harvesting systems to the dynamics of quantum walks, in order to elucidate the limits of such quantum speedups. For the Fenna-Matthews-Olson (FMO) complex of green sulfur bacteria, we show that while there is indeed speedup at short times, this is short lived (70 fs) despite longer lived (ps) quantum coherence. Remarkably, this time scale is independent of the details of the decoherence model. More generally, we show that the distinguishing features of light-harvesting complexes not only limit the extent of quantum speedup but also reduce rates of diffusive transport. These results suggest that quantum coherent effects in biological systems are optimized for efficiency or robustness rather than the more elusive goal of quantum speedup.Comment: 9 pages, 6 figures. To appear in New Journal Physics, special issue on "Quantum Effects and Noise in Biomolecules." Updated to accepted versio

Search for Higgs and New Phenomena at Colliders

The present status of searches for the Higgs boson(s) and new phenomena is reviewed. The focus is on analyses and results from the current runs of the HERA and Tevatron experiments. The LEP experiments have released their final combined MSSM Higgs results for this conference. Also included are results from sensitivity studies of the LHC experiments and lepton flavour violating searches from the B factories, KEKB and PEP-II.Comment: XXII International Symposium on Lepton-Photon Interactions at High Energy (11 pages, 16 figures, 2 tables

Audit on the use of radiological investigations in the management of rhinosinusitis

Objectives: The aim of this audit is to establish the cost to the Maltese health system from the use of radiological imaging in managing rhinosinusitis and to identify areas in which these costs can be minimised by following guidelines on the management of rhinosinusitis. Methods: All plain radiographs and computed tomography scans (CT) of the paranasal sinuses requested in the Mater Dei Hospital over a one year period were analysed. Data was collected regarding: the quantity of investigations ordered, age of the patients, cost and requesting department. Results: Over one year: 205 CT scans and 113 sets of plain radiographs of the paranasal sinuses were requested, costing a total of euro103,440. The majority (73%) were elective requests made by ENT consultants. Five percent of CT scans were requested for patients less than 10 years of age. Conclusion: Rhinosinusitis is diagnosed clinically, only requiring radiological investigation in more complex cases best managed by specialists in ENT. Plain radiographs have limited use in the management of rhinosinusitis. Judicious use of imaging requests whilst following clinical guidelines is required to save money and minimise patient exposure to ionising radiation.peer-reviewe

Voluntary contributing in a neighborhood public good game: An experimental study

In repeated Public Good Games contributions might be influenced by different motives. The variety of motives for deciding between (more or less) free-riding probably explains the seemingly endless tradition of theoretical and experimental studies of repeated Public Good Games. To more clearly distinguish the motives, we try to enrich the choice set by allowing players not only to contribute but also to locate their contribution to one of the player positions. The location choice affects what individual players gain, but not the overall efficiency of contributing, and allows for discrimination, e.g., rewarding and sanctioning co-players differently. Our experimental results show that adding location choice promotes voluntary cooperation, although discrimination itself has no signifficant effect on behavior. --Public Good Game,Neighborhood,Cooperation,Experimental Analysis