Fatigue loading history reconstruction based on the rain-flow technique

Methods are considered for reducing a non-random fatigue loading history to a concise description and then for reconstructing a time history similar to the original. In particular, three methods of reconstruction based on a rain-flow cycle counting matrix are presented. A rain-flow matrix consists of the numbers of cycles at various peak and valley combinations. Two methods are based on a two dimensional rain-flow matrix, and the third on a three dimensional rain-flow matrix. Histories reconstructed by any of these methods produce a rain-flow matrix identical to that of the original history, and as a result the resulting time history is expected to produce a fatigue life similar to that for the original. The procedures described allow lengthy loading histories to be stored in compact form

Altruism and Voluntary Provision of Public Goods.

We study how people's predisposition towards altruism, as measured by tools developed by psychologists, affects their behaviour in a voluntary contributions public good environment. Earlier experiments provide evidence against the strong free rider hypothesis; however, contributions to the public good decrease with repetition. We investigate whether a high level of contributions can be sustained in groups of subjects who have been pre-selected on the basis of their altruistic inclinations. In the first stage of the experiment, each subject responds to a psychology questionnaire that measures various dimensions of one's personality. The subjects are then matched in groups according to their altruism scores, and engage in a voluntary contribution game. We consider whether the levels and dynamics of group contributions differ significantly between the groups with altruists and non-altruists. We find that subjects' altruism has a weak but positive effect on group behaviour in the public good game.PUBLIC OWNERSHIP ; BEHAVIOUR ; GAMES

Unravelling the anti-inflammatory mechanisms of dietary fatty acids

Polyunsaturated fatty acids (PUFA) have been shown to modulate immune responses and have therapeutic effects in inflammatory disorders. The specific mechanisms of their actions have yet to be defined. The objective of this work was to elucidate such mechanisms. Macrophages are a key component of the innate response, which express toll-like receptors (TLRs). Ligation of TLR4, by its ligand lipopolysaccharide (LPS), results in macrophage activation. This study demonstrates that the n-6 derivative, conjugated linoleic acid (CLA) and n-3 PUFA, DHA and EPA differentially modulate the response of macrophages to LPS. Specifically, phagocytosis was enhanced by CLA and suppressed by n-3 PUFA and these PUFA suppressed TNFα, IL-6 and enhanced IL-10 production, rendering the macrophage less inflammatory. PUFA also suppressed macrophage migration in response to LPS and inhibited production of chemokines. Furthermore, CLA inhibited activation of the TLR4 downstream transcription factors NF-κB and IRF3, while n-3 PUFA, DHA and EPA solely inhibited NF-κB. Further investigation revealed that PUFA selectively regulate the expression of TLR4 and its associated molecule CD14 in response to LPS, but had no effect on LPS binding to TLR4. The exact mechanism of the effects of PUFA on CD14 was elucidated by examining lipid raft 'microdomains', the location where the receptor complex clusters upon activation. We found that treatment of macrophages with CLA reduced the incorporation of CD14 into lipid rafts following activation with LPS. We then examined endocytosis of TLR4 given the role of CD14 in this process, and we found that it was suppressed by CLA. This study therefore reveals a novel mechanism whereby CLA exerts its antiinflammatory effects. This involves suppression of CD14, the subsequent suppression of TLR4 endocytosis culminating in decreased IRF3 activation

Generation of Large Number-Path Entanglement Using Linear Optics and Feed-Forward

We show how an idealised measurement procedure can condense photons from two modes into one, and how, by feeding forward the results of the measurement, it is possible to generate efficiently superpositions of components for which only one mode is populated, commonly called ``N00N states''. For the basic procedure, sources of number states leak onto a beam splitter, and the output ports are monitored by photodetectors. We find that detecting a fixed fraction of the input at one output port suffices to direct the remainder to the same port with high probability, however large the initial state. When instead photons are detected at both ports, Schr\"{o}dinger cat states are produced. We describe a circuit for making the components of such a state orthogonal, and another for subsequent conversion to a N00N state. Our approach scales exponentially better than existing proposals. Important applications include quantum imaging and metrology

Quantum enhanced spectroscopy with entangled multi-photon states

Traditionally, spectroscopy is performed by examining the position of absorption lines. However, at frequencies near the transition frequency, additional information can be obtained from the phase shift. In this work we consider the information about the transition frequency obtained from both the absorption and the phase shift, as quantified by the Fisher information in an interferometric measurement. We examine the use of multiple single-photon states, NOON states, and numerically optimized states that are entangled and have multiple photons. We find the optimized states that improve over the standard quantum limit set by independent single photons for some atom number densities.Comment: 6 pages, 8 figures, comments are welcom

Geotourism destinations - visitor impacts and site management considerations

Geotourism is becoming a well established form of tourism based on the geological environment. It offers a new form of sustainable tourism which is more holistic than previous niche forms of tourism. However, with more people than ever visiting natural areas worldwide, the cumulative impacts of visitors on geological sites is increasing. This paper surveys visitor impacts and site management at geological sites which are geotourism destinations. We describe geotourism which is the engine driving the core activities of conservation, education and sustainable development in geoparks. We then outline some lessons learned from management in dealing with visitor impacts at a heavily visited geopark in Taiwan, a volcano in Indonesia and a coastal World Heritage site in England. The importance of education is emphasized for geo-climbing in Spain and all-terrain vehicles in Poland. A number of site management approaches are noted, including the importance of guiding as a management strategy as well as the value of a positive involvement by the local community. Finally, some examples are given of the risks associated with tourism activities in volcanic areas as well as related appropriate management activities