Large effects of boundaries on spin amplification in spin chains

We investigate the effect of boundary conditions on spin amplification in spin chains. We show that the boundaries play a crucial role for the dynamics: A single additional coupling between the first and last spins can macroscopically modify the physical behavior compared to the open chain, even in the limit of infinitely long chains. We show that this effect can be understood in terms of a "bifurcation" in Hilbert space that can give access to different parts of Hilbert space with macroscopically different physical properties of the basis functions, depending on the boundary conditions. On the technical side, we introduce semiclassical methods whose precision increase with increasing chain length and allow us to analytically demonstrate the effects of the boundaries in the thermodynamic limit.Comment: replaced figs. 6,10 and corrected corresponding numerical values for initial slopes, added a new fig.7 and a section on total fidelitie

Putting the Lab in the Lab Book: Supporting Coordination in Large, Multi-site Research

Large and distributed science projects present researchers with a challenging environment for interaction and collaboration. While digital technologies offer promises in supporting these difficulties, researchers appear reluctant to discontinue their use of analogue resources. We present a study of communication practices in very large-scale collaborative scientific research programmes that involve multidisciplinary and multinational research consortia. Qualitative data collection with researchers, principal investigators and project coordinators were carried out to examine the conduct and coordination of biological, biomedical and chemistry experiments that were distributed over multiple geographical locations. Results show that many problems in collaboration appear to result from the collective documentation of experimental operating procedures, tracking of experimental samples, and the sharing and cross-association of physical and digital experimental materials. Our analysis highlights the crucial but problematic role of the laboratory notebook as a driver for collaboration, most notably in supporting traceability of the distributed experimental process. We identify opportunities for improving experimental coordination, scientific communication and project synchronisation, drawing implications for digital interaction design that offers opportunities to enhance research coordination

Information Systems Undergraduate Degree Project: Gaining a Better Understanding of the Final Year Project Module

The place of an individual project in the final year of Information Systems (IS) undergraduate degrees at UK universities is well established. In this paper we compare the final year project modules at four UK universities: the University of Brighton, the University of South Wales, University of West London and the University of Westminster. We find that the aims of the projects are similar, emphasising the application of the knowledge and skills from the taught element of their course in a complex development project, often including interactions with a real client. Although we show in this analysis that projects serve a similar purpose in the IS degree courses, the associated learning outcomes and the assessment practice varies across the institutions. We identify some gaps in the skills and abilities that are not being assessed. In further work we are planning to consult final year students undertaking their projects and their supervisors, in order to gain an understanding of how project assessment criteria are actually put to use

Approche semi-classique de l'information quantique

Aujourd'hui, une large communauté de scientifiques travaille en vue de la réalisation d'un ordinateur quantique, une machine dont il est montré qu'elle peut offrir, au moins en théorie, et en particulier pour les problèmes dont la complexité croît exponentiellement avec la taille du système, des performances inaccessibles à ses homologues classiques. Cette thèse s'intéresse à la possibilité de réaliser une approche semi-classique de l'information quantique dans deux domaines d'intérêt : celui du clonage approché d'un qubit, et celui de l'amplification de spins dans des chaînes de spins. Dans la première partie de cette thèse est étudié le rôle de l'interférence dans les cloneurs quantiques. Nous étudions en particulier le cas de cloneurs sans interférence (au sens définit dans la thèse) qui se révèle être un cas intermédiaire (que l'on peut qualifier de semi-classique) entre les cloneurs purement quantiques (qui propagent cohérences et probabilités des matrices densités) et les cloneurs classiques (qui ne propagent que les probabilités). Dans la seconde partie, on s'intéresse au phénomène d'amplification de spin qui permet d'amplifier l'état d'un spin unique comme état de polarisation de la chaîne toute entière, problème pour lequel l'approche semi-classique (valable en raison du grand nombre de spins) est utilisée pour montrer l'importance inattendue jouée par les effets de bords dans de tels systèmes.Today, a large community of scientists is working to make possible the achievement of a quantum computer, a machine that can offer at least in theory (and especially for problems whose complexity grows exponentially with the size of the system) a degree of performance inaccessible to its classical counterpart. This thesis is looking at the possibility of producing a semi-classical approach of quantum information in two areas of interest: the cloning of a qubit, and the amplification of spin in spin chains. In the first part of this thesis is studied the role of interference in quantum cloners. We study in particular the case of cloners without interference (as defined, in the thesis) that turned out to be an intermediary case (that can be qualified of semi-classical) between purely quantum cloners (which propagate coherences and probabilities of density matrices) and classical cloners (which carry only the probabilities). In the second part, the phenomenon of amplification is studied in spin chains, which allows to amplify the state of a unique spin in a state of polarization of the entire chain, problem for which the semi-classical approach (valid because of the large number of spins) is used to show the unexpectedly important role played by the edge effects in these kind of systems

Obesity-Induced Inflammation in Human Mammary Tissue: A Potential Microenvironment Favorable to the Development of Postmenopausal Breast Cancer Via the Wnt Signaling Pathway

In the United States, over one third of adult women are obese, and one in eight women will be diagnosed with breast cancer in their lifetime. Obesity has been shown to be a risk factor for postmenopausal breast cancer and is associated with increased aggressiveness and poor prognosis regardless of menopausal status. However, the mechanisms involved in the relationship between obesity and breast cancer are still not fully understood. Wnt signaling is often elevated in breast tumors (~60%) and is suspected to play a key role in cancer development. It has been shown that inflammatory cytokines, such as TNF-α, IL-1β, IFNγ, are potential mediators in the regulation of Wnt-signaling. We hypothesize that the low-grade inflammatory state associated with obesity is present in human mammary tissue, stimulates Wnt activity, and thereby leads to the development of breast cancer. In this project, we propose to 1) characterize the inflammatory cytokine profile, including IFN-γ, IL-1β, IL-2, IL-6, IL-8, and TNF-α, in the mammary tissue of normal weight, overweight, and obese postmenopausal women using a high performance electrochemiluminescence immunoassay; 2) determine the influences of the obesity-induced pro-inflammatory cytokines on Wnt-signaling by examining gene expression of seven Wnt-signaling target genes using real-time PCR; and 3) define the causality between TNF-α, one of the mot critical inflammatory cytokines, and Wnt signaling by measuring the gene expression of the Wnt targets in samples from normal to overweight and obese postmenopausal women treated with anti-TNF-α antibody or TNF-α recombinant protein respectively. We expect to define a novel mechanism that obesity mediates the development of postmenopausal breast via inflammation-driven Wnt signaling

Nanotechnology in medicine: European research and its implications

In this study, we explore and discuss nanoparticles and nanoscale materials and their use in medicine (nanomedicine) and pharmaceutics (nanopharmaceutics). The study is aimed at shedding light on this highly multidisciplinary research field and at examining the influence of research funding, industrial applications, and legal and regulatory frameworks on the research in this field, a clear understanding of which is essential to efficiently support the translation of research findings into industrial and clinical applications and to enable access to a larger society

Managing Operating Procedures in Distributed Collaborative Projects

In recent years, large distributed collaborative projects have become very prominent in scientific research, allowing exchanges between laboratories located in different institutions and countries and between various domains of competence. Particularly the work on nanotoxicity – a field which has only been under investigation for a few years and is still lacking regulatory framework – highlighted the need for well-controlled methods, as well as rules for the handling and disposal of used materials. To obtain comparable and reproducible results of experiments conducted in a distributed context, the standardisation and proper documentation of the applied methods is crucial. The European project NanoDiaRA, whose aim is to develop nanoparticles and biomarkers for the early diagnosis of inflammatory disease, faces this situation as it involves 15 European partners and brings together different scientific cultures and professional backgrounds. Protocols especially developed for Superparamagnetic Iron Oxide Nanoparticles and a management system were designed and implemented within the NanoDiaRA project to fulfil those needs. The main goals were the establishment of standardised Standard Operating Procedures assuring transparency and reproducibility and the provision of access to these protocols to every project partner, as well as their clear allocation to carry out precise measurements and production steps

L’Histoire de la photographie : (en)quête de méthode

Signe de vitalité, l’histoire de la photographie enquête sur ses classiques. Dans La Mission héliographique, Anne de Mondenard nous compte par le menu l’histoire de la toute première commande publique collective de l’histoire de la photographie : en 1851, la commission des Monuments historiques envoie cinq photographes —Edouard Baldus, Hippolyte Bayard, Gustave Le Gray, Henri Le Secq et Mestral— recueillir des photographies des édifices historiques du territoire français. Depuis l’héritage de..

The History of Photography: (Re)Search Into Method

Like a sign of vitality, the history of photography investigates its classics. In La Mission héliographique, Anne de Mondenard takes us through the slim history of the very first collective public commission in the history of photography: in 1851, the Historic Monuments Commission sent five photographers–Edouard Baldus, Hippolyte Bayard, Gustave Le Gray, Henri Le Secq and Mestral–to take photographs of France’s historic buildings. From Baron Taylor’s legacy of the Voyages pittoresques et roma..