Operational determination of multi-qubit entanglement classes via tuning of local operations

We present a physical setup with which it is possible to produce arbitrary symmetric long-lived multiqubit entangled states in the internal ground levels of photon emitters, including the paradigmatic GHZ and W states. In the case of three emitters, where each tripartite entangled state belongs to one of two well-defined entanglement classes, we prove a one-to-one correspondence between well-defined sets of experimental parameters, i.e., locally tunable polarizer orientations, and multiqubit entanglement classes inside the symmetric subspace.Comment: Improved version. Accepted in Physical Review Letter

Generation of Symmetric Dicke States of Remote Qubits with Linear Optics

We propose a method for generating all symmetric Dicke states, either in the long-lived internal levels of N massive particles or in the polarization degrees of freedom of photonic qubits, using linear optical tools only. By means of a suitable multiphoton detection technique, erasing Welcher-Weg information, our proposed scheme allows the generation and measurement of an important class of entangled multiqubit states.Comment: New version, a few modifications and a new figure, accepted in Physical Review Letter

Surface Studies of Oxidation of a Single-Grain Quasicrystal

We have used Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and low-energy electron diffraction (LEED) to characterize the surface properties of a single-grain Al70Pd21Mn9 (APM) quasicrystal (QC) upon oxidation. When oxygen is adsorbed on this surface, a disordered layer is formed at low coverages. This chemisorbed oxygen destroys the five-fold quasiperiodicity completely. Further adsorption of oxygen leads to a thin layer (less than 20 A) of AI oxide which passivates the surface. At elevated temperatures (870 K), adsorption of oxygen induces an enrichment of AI on the surface. This is explained by the exothermicity of its oxide and the possibility of increased mobility of AI at higher temperatures. Al is the only element in this QC which can be oxidized. No evidence of oxidization for Pd and Mn is observed

Liver Transplantation in Older Patients

To the Editor: The impact of liver transplantation on public health policy has not been delineated, partly because of uncertainty about the upper age limit for candidacy. We have compared the outlook in 363 adult recipients of livers who were less than 50 years old (mean +SD, 35.8+8.5) and 92 recipients who were 50 to 77 years old (mean +SD, 55.7+4.8). Cyclosporine and steroids1,2 were used for immunosuppression, and monoclonal antilymphocyte globulin3 and azathioprine were added as needed. The techniques of liver transplantation4 were not influenced by the age of the patient. The indications for transplantation are shown in Figure 1…., No extract is available for articles shorter than 400 words. © 1987, Massachusetts Medical Society. All rights reserved

Is Category Expansion a Realistic Long-Term Objective for Established Brands?

How often do established CPG categories expand following a period of stationarity? To what extent can the levers under manufacturer control bring about persistent growth in total category value? The authors explore these questions in order to test the commonly held assertion that brand leaders in established markets can grow sales by expanding total category demand. Findings from a study of US household panel data describing the purchasing of nearly 500 small and large categories by 60,000 households over a nine-year period are presented. The observations focus on the growth impact of three sales levers, category penetration, purchase volume per buyer, and price per volume paid, in various strategic windows ranging from one to nine years. The results demonstrate that category penetration increase is the most likely lever for category growth. The association between over-time revenue increase and growth in buying household numbers is far stronger than that between unit price increases or category usage. While this clearly indicates a promising strategic direction for brand management, results also carry a health warning: categories are relatively volatile in the short term, but highly stable over time, therefore while the direction is clear the path is very narrow indeed

Marketing research faces two challenges and a world of opportunity with long-term panel data

There have been frequent calls in the literature for a more comprehensive understanding of marketing impact on long-term firm performance (Dawes, Meyer-Waarden, & Driesener, 2015; Hanssens & Pauwels, 2016; Lodish & Mela, 2007; Webster & Lusch, 2013). Retail scanner data has been the principal source of empirical evidence in this strategic domain, but it cannot explain the behavioural shifts that underpin sales dynamics. Now that far larger extended household panels are available, there is, for the first time, a valuable behavioural lens with which to observe long-term brand and category buying. In this paper we outline theoretical and methodological challenges to this new type of panel research. The first concerns an approach to extending established marketing theory to long-run repeat buying; the second relates to the inherent constraints of long-term panels. We present a new research agenda to progress explanatory theories of long-run brand building and category growth in this new but largely untapped resource

Quangos - What's in a name? Defining Quangos from a Comparative Perspective

Without definitional clarity the 'quango debate' is inherently flawed and meaningful progress undermined. A possible solution to this problem is proposed in this article by way of a subsectional map which aims to clarify the quango topography. This accepts the diversity inherent in the quango debate whilst allowing for increased clarity and focused research. This, the authors believe, is the only way forward for practitioners, academics and policy makers working within the sphere of quasi-government. There is a need to address precise forms or subsections of the quango continuum as studies or reforms which focus on one type of quango would not necessarily work if applied to all quangos, or quangos in other countries

Quantum Imaging with Incoherent Photons

We propose a technique to obtain sub-wavelength resolution in quantum imaging with potentially 100% contrast using incoherent light. Our method requires neither path-entangled number states nor multi-photon absorption. The scheme makes use of N photons spontaneously emitted by N atoms and registered by N detectors. It is shown that for coincident detection at particular detector positions a resolution of \lambda / N can be achieved.Comment: 4 pages, 3 figures, improved presentation. Accepted in Physical Review Letter