Breaking time-inversion invariance through decoherence : energetic consequences for attosecond neutron scattering

Nuclei and electrons in condensed matter and/or molecules are usually entangled, due to the prevailing (mainly electromagnetic) interactions. However, the "environment" of a microscopic scattering system (e.g. a proton) causes ultrafast decoherence, thus making atomic and/or nuclear entanglement e®ects not directly accessible to experiments. However, our neutron Compton scattering experiments from protons (H-atoms) in condensed systems and molecules have a characteristic collisional time about 100|1000 attoseconds. The quantum dynamics of an atom in this ultrashort, but ¯nite, time window is governed by non-unitary time evolution due to the aforementioned decoherence. Unexpectedly, recent theoretical investigations have shown that decoherence can also have the following energetic consequences. Disentangling two subsystems A and B of a quantum system AB is tantamount to erasure of quantum phase relations between A and B. This erasure is widely believed to be an innocuous process, which e.g. does not a®ect the energies of A and B. However, two independent groups proved recently that disentangling two systems, within a su±ciently short time interval, causes increase of their energies. This is also derivable by the simplest Lindblad-type master equation of one particle being subject to pure decoherence. Our neutron-proton scattering experiments with H2 molecules provide for the first time experimental evidence of this e®ect. Our results reveal that the neutron-proton collision, leading to the cleavage of the H-H bond in the attosecond timescale, is accompanied by larger energy transfer (by about 2|3%) than conventional theory predicts. Preliminary results from current investigations show qualitatively the same e®ect in the neutron-deuteron Compton scattering from D2 molecules. We interpret the experimental findings by treating the neutron-proton (or neutron-deuteron) collisional system as an entangled open quantum system being subject to fast decoherence caused by its "environment" (i.e., two electrons plus second nucleus of H2 or D2). The presented results seem to be of generic nature, and may have considerable consequences for various processes in condensed matter and molecules, e.g. in elementary chemical reactions.

Time-domain hydroelastic analysis of a flexible marine structure using state-space models

This article deals with time-domain hydroelastic analysis of a marine structure. The convolution terms associated with fluid memory effects are replaced by an alternative state-space representation, the parameters of which are obtained by using realization theory. The mathematical model established is validated by comparison to experimental results of a very flexible barge. Two types of time-domain simulations are performed: dynamic response of the initially inert structure to incident regular waves and transient response of the structure after it is released from a displaced condition in still water. The accuracy and the efficiency of the simulations based on the state-space model representations are compared to those that integrate the convolutions.

Wasting Time? Art, Science and New Experience. Examining the Artwork, Know more (House of Commons)

Today the future is travelling rapidly towards us, shaped by all that which we have historically thrown into it. Much of what we have designed for our world over the ages, and much of what we continue to embrace in the pursuit of mainstream economic, cultural and social imperatives, embodies unacknowledged ‘time debts’. Every decision we make today has the potential to ‘give time to’, or take ‘time away’ from that future. This idea that ‘everything‘ inherently embodies ‘future time left’ is underlined by design futurist Tony Fry when he describes how we so often ‘waste’ or ‘take away’ ‘future time’. “In our endeavours to sustain ourselves in the short term we collectively act in destructive ways towards the very things we and all other beings fundamentally depend upon”

Time- vs. frequency-domain identification of parametric radiation force models for marine structures at zero speed

The dynamics describing the motion response of a marine structure in waves can be represented within a linear framework by the Cummins Equation. This equation contains a convolution term that represents the component of the radiation forces associated with fluid memory effects. Several methods have been proposed in the literature for the identification of parametric models to approximate and replace this convolution term. This replacement can facilitate the model implementation in simulators and the analysis of motion control designs. Some of the reported identification methods consider the problem in the time domain while other methods consider the problem in the frequency domain. This paper compares the application of these identification methods. The comparison is based not only on the quality of the estimated models, but also on the ease of implementation, ease of use, and the flexibility of the identification method to incorporate prior information related to the model being identified. To illustrate the main points arising from the comparison, a particular example based on the coupled vertical motion of a modern containership vessel is presented.

Histories of user-generated content : between formal and informal media economies

Debates about user-generated content (UGC) often depend on a contrast with its normative opposite, the professionally produced content that is supported and sustained by commercial media businesses or public organisations. UGC is seen to appear within or in opposition to professional media, often as a disruptive, creative, change-making force. Our suggestion is to position UGC not in opposition to professional or "producer media", or in hybridised forms of subjective combination with it (the so-called "pro-sumer" or "pro-am" system), but in relation to different criteria, namely the formal and informal elements in media industries. In this article, we set out a framework for the comparative and historical analysis of UGC systems and their relations with other formal and informal media activity, illustrated with examples ranging from games to talkback radio. We also consider the policy implications that emerge from a historicised reading of UGC as a recurring dynamic within media industries, rather than a manifestation of consumer agency specific to digital cultures.

Time kinetics of bone defect healing in response to BMP-2 and GDF-5 characterised by in vivo biomechanics

This study reports that treatment of osseous defects with different growth factors initiates distinct rates of repair. We developed a new method for monitoring the progression of repair, based upon measuring the in vivo mechanical properties of healing bone. Two different members of the bone morphogenetic protein (BMP) family were chosen to initiate defect healing: BMP-2 to induce osteogenesis, and growth-and-differentiation factor (GDF)-5 to induce chondrogenesis. To evaluate bone healing, BMPs were implanted into stabilised 5 mm bone defects in rat femurs and compared to controls. During the first two weeks, in vivo biomechanical measurements showed similar values regardless of the treatment used. However, 2 weeks after surgery, the rhBMP-2 group had a substantial increase in stiffness, which was supported by the imaging modalities. Although the rhGDF-5 group showed comparable mechanical properties at 6 weeks as the rhBMP-2 group, the temporal development of regenerating tissues appeared different with rhGDF-5, resulting in a smaller callus and delayed tissue mineralisation. Moreover, histology showed the presence of cartilage in the rhGDF-5 group whereas the rhBMP-2 group had no cartilaginous tissue. Therefore, this study shows that rhBMP-2 and rhGDF-5 treated defects, under the same conditions, use distinct rates of bone healing as shown by the tissue mechanical properties. Furthermore, results showed that in vivo biomechanical method is capable of detecting differences in healing rate by means of change in callus stiffness due to tissue mineralisation.

Crunch time : how did the students perform?

Two newspaper numbers games based on simple arithmetic relationships are discussed. One is rather trivial, but very useful as an introduction to the second, whose potential to give students of elementary algebra practice in semi ad-hoc reasoning and to build general arithmetic reasoning skills was explored theoretically in an earlier paper. Preliminary results on the effectiveness of this general approach are presented, with student performance and feedback on an assignment task and formal examination included, and recommendations for future work.

Time for a national approach to donor conception in Australia

There is a growing recognition of the interests and rights of individuals conceived using donated gametes in assisted reproductive technology to information about their biological parentage. In Australia these rights vary between jurisdictions according to differing statutory provisions. In February 2011 the Senate's Legal and Constitutional Affairs References Committee published its report on Donor Conception Practices in Australia. The report recommended the development of a nationally consistent approach to donor conception and recommended the enactment of legislation in those Australian jurisdictions without legislation regulating donor conception. This editorial reviews the Senate Committee report and its recommendations and supports calls for a nationally harmonised approach to donor conception in Australia.

Dark Cartographies

‘Dark Cartographies’ is a slowly evolving meditation upon seasonal change, life after light and the occluding shadows of human influence. Through creating experiences of the many ‘times of a night’ the work allows participants to experience deep engagement with rich spectras of hidden place and sound. By amplifying and shining light upon a myriad of lives lived in blackness, ‘Dark Cartographies’ tempts us to re-understand seasonal change as actively-embodied temporality, inflected by our climate-changing disturbances. ‘Dark Cartographies’ uses custom interactive systems, illusionary techniques and real time spatial audio that draw upon a rich array of media, including seasonal, nocturnal field recordings sourced in the Far North Queensland region and detailed observations of foliage & flowering phases. By drawing inspiration from the subtle transitions between what Europeans named ‘Summer’ and ‘Autumn’, and by including the body and its temporal disturbances within the work, ‘Dark Cartographies’ creates compellingly immersive environments that wrap us in atmospheres beyond sight and hearing. ‘Dark Cartographies’ is a dynamic new installation directed & choreographed by environmental cycles; alluding to a new framework for making works that we call ‘Seasonal’. This powerful, responsive & experiential work draws attention to that which will disappear when biodiverse worlds have descended into an era of permanent darkness – an ‘extinction of human experience’. By tapping into the deeply interlocking seasonal cycles of environments that are themselves intimately linked with social, geographical & political concerns, participating audiences are therefore challenged to see the night, their locality & ecologies in new ways through extending their personal limits of perception, imagery & comprehension.

Night Rage/ Night Fall

A new form of media installation combining image, multi-channel sound and internally lit objects into a mysterious, deep image plane. Staged on the very edge of spectrum blackout, and moving into the deep of night, Version 1 (Night Rage) for ISEA 2013 examined the many shades of 'nocturnal', threats to night biodiversity and the myriad myths and stories that have shaped our cultural understandings of life after light. Barely recognisable images float within landscapes of media, noise and sound as the work asserts a profound resistance to today's all consuming media mesh. Version 2 (Night Fall) for the Queensland State Museum examined contemporary ideas around the ‘night’ and the 'nocturnal'. Beginning with the dark myths and stories that have long shaped our cultural understandings of life after light, NIGHT FALL considers how fearful ideas have often underpinned actions that continue to reduce Australia’s extraordinary night biodiversity. Today’s growing hostility towards Australia’s ancient, iconic flying foxes - who have been quietly pollinating our forests for millennia - hints at just how far we have yet to travel in our thinking. Enter the darkened tunnel to experience mysterious, edge-of-perception 3D forms, enhanced by a range of cinematic, illusionary and animatronic techniques, and become immersed in a strangely familiar sound track based upon seasonal field recordings made after dark, sourced from across the eastern coast of Queensland.

Long time, no see?

Long Time, No See? is a crowd-sourced project that asks people to reflect upon what kind of long term future they would each like to promote. It is an evolving experiment in the social practice of ‘everyday futuring’. To participate download the Long Time, No See? IPhone APP that gently guides you during a short walk, encouraging you to experience new places, sensations and thoughts in your locality. At nine stages along that journey you donate ‘field notes’ as images, texts, sounds and ‘themes’, offering a unique opportunity to reveal possible pathways towards more sustaining futures. The APP records the shape of your walk on the ground and draws an island on the ‘map’ shown here, populated by your nine sets of responses. The themes you have chosen then connect your island into an evolving ‘world’ map of connections and possibilities, which you can then explore at your leisure. In these ways, Long Time, No See? doesn’t ask you for lofty visions or ask you to lay out a program of action, but instead asks you to consider what is around you today, steering your eyes, ears and embodied experiences towards new futures that demonstrate your ‘care’ for what comes after you. Please use the contribute tab below to learn how to add your voice! PARTICIPATE To contribute 1: Download the APP {bit.do/ltns}, iPhone/iPad is supported right now. 2: Register a ‘walker name’. 3: Take a leisurely walk (30 -60mins) and contribute image, text, sound and themes when asked. 4: Wait while we verify and upload your walk (allow about 24 hours) 5: View your contributions via your ‘walker name’ and discover how it relates to others, here at the Cube and at www.long-time-no-see.org. NB You can undertake each walk over more than one day if that suits. You may even drive, cycle or move by other modes. DOWNLOAD THE APP: bit.do/ltns (insert QI Code) FIND OUT MORE www.long-time-no-see.org

Study on dynamic system optimum assignment to establish marginal time equilibrium

Several analytical methods for Dynamic System Optimum (DSO) assignment have been proposed but they are basically classified into two kinds. This chapter attempts to establish DSO by equilbrating the path dynamic marginal time (DMT). The authors analyze the path DMT for a single path with tandem bottlenecks and showed that the path DMT is not the simple summation of DMT associated with each bottleneck along the path. Next, the authors examined the DMT of several paths passing through a common bottleneck. It is shown that the externality at the bottleneck is shared by the paths in proportion to their demand from the current time until the queue vanishes. This share of the externality is caused by the departure rate shift under first in first out (FIFO) and the externality propagates to the downstream bottlenecks. However, the externalities propagates to the downstream are calculated out if downstream bottlenecks exist. Therefore, the authors concluded that the path DMT can be evaluated without considering the propagation of the externalities, but just as in the evaluation of the path DMT for a single path passing through a series of bottlenecks between the origin and destination. Based on the DMT analysis, the authors finally proposed a heuristic solution algorithm and verified it by comparing the numerical solution with the analytical one.

Benefit of accident reduction considering the improvement of travel time reliability

Traffic accidents often cause lane closure, and diminish stability of travel time as well as the level of road services. On the other hand, research on the implementation of ITS services aiming at the reduction of traffic accidents has made considerable progress lately. However there has been little discussion on the benefits obtained by traffic accident reduction from the view point of travel time reliability. Therefore, in this research, relationships between traffic accidents and travel time reliability are examined, and the benefit of traffic accident reduction is calculated based on the scheduling model under travel time uncertainties. The results show the significance of traffic accident reduction for the improvement of travel time reliability.

Dynamic changes in high and low mammographic density human breast tissues maintained in murine tissue engineering chambers during various murine peripartum states and over time

Mammographic density (MD) is a strong heritable risk factor for breast cancer, and may decrease with increasing parity. However, the biomolecular basis for MD-associated breast cancer remains unclear, and systemic hormonal effects on MD-associated risk is poorly understood. This study assessed the effect of murine peripartum states on high and low MD tissue maintained in a xenograft model of human MD. Method High and low MD human breast tissues were precisely sampled under radiographic guidance from prophylactic mastectomy specimens of women. The high and low MD tissues were maintained in separate vascularised biochambers in nulliparous or pregnant SCID mice for 4 weeks, or mice undergoing postpartum involution or lactation for three additional weeks. High and low MD biochamber material was harvested for histologic and radiographic comparisons during various murine peripartum states. High and low MD biochamber tissues in nulliparous mice were harvested at different timepoints for histologic and radiographic comparisons. Results High MD biochamber tissues had decreased stromal (p = 0.0027), increased adipose (p = 0.0003) and a trend to increased glandular tissue areas (p = 0.076) after murine postpartum involution. Stromal areas decreased (p = 0.042), while glandular (p = 0.001) and adipose areas (p = 0.009) increased in high MD biochamber tissues during lactation. A difference in radiographic density was observed in high (p = 0.0021) or low MD biochamber tissues (p = 0.004) between nulliparous, pregnant and involution groups. No differences in tissue composition were observed in high or low MD biochamber tissues maintained for different durations, although radiographic density increased over time. Conclusion High MD biochamber tissues had measurable histologic changes after postpartum involution or lactation. Alterations in radiographic density occurred in biochamber tissues between different peripartum states and over time. These findings demonstrate the dynamic nature of the human MD xenograft model, providing a platform for studying the biomolecular basis of MD-associated cancer risk. © 2013 Springer Science+Business Media New York.

Time to face the fats : What can mass spectrometry reveal about the structure of lipids and their interactions with proteins?

Since the 1950s, X-ray crystallography has been the mainstay of structural biology, providing detailed atomic-level structures that continue to revolutionize our understanding of protein function. From recent advances in this discipline, a picture has emerged of intimate and specific interactions between lipids and proteins that has driven renewed interest in the structure of lipids themselves and raised intriguing questions as to the specificity and stoichiometry in lipid-protein complexes. Herein we demonstrate some of the limitations of crystallography in resolving critical structural features of ligated lipids and thus determining how these motifs impact protein binding. As a consequence, mass spectrometry must play an important and complementary role in unraveling the complexities of lipid-protein interactions. We evaluate recent advances and highlight ongoing challenges towards the twin goals of (1) complete structure elucidation of low, abundant, and structurally diverse lipids by mass spectrometry alone, and (2) assignment of stoichiometry and specificity of lipid interactions within protein complexes.