Assessing narrative comprehension in young children

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88014/1/RRQ.38.1.3.pd

Hanging out on Snapchat: disrupting passive covert netnography in tourism research

Tourism research is increasingly turning to online social media conversations as a data source, but seldom assigning space in research outputs for ethical appraisals or reflexive accounts of data collection. Many tourism researchers download conversations after they have occurred, but presence is central to gaining rich insights through netnographic research. We contribute to and disrupt online tourism research by critiquing, extending, and adapting existing methods to Snapchat, which in itself disrupts possibilities for online data collection. Hanging out with tourist Snapchatters highlights how privacy concerns are a primary motive to post on Snapchat. Snapchat is understood by our participants as more private than other social media sites due to the ephemerality of content and the notification of screenshots (when others save your snap). It is no coincidence that these same functionalities render established methods of digital tourism research difficult in the case of Snapchat. Snapchat users also problematise the notion of social media as public space, as they utilise the platforms for much more than communicating with the world. Snapchatters create, augment, and store memories

Special issue "The past and present threat of rickettsial diseases"

Historically, the rickettsioses have a track record of making substantial impact on mankind in military activities and international public health over the past centuries [...]

Stationary entanglement in N-atom subradiant degenerate cascade systems

We address ultracold $N$-atom degenerate cascade systems and show that stationary subradiant states, already observed in the semiclassical regime, also exist in a fully quantum regime and for a small number of atoms. We explicitly evaluate the amount of stationary entanglement for the two-atom configuration and show full inseparability for the three-atom case. We also show that a continuous variable description of the systems is not suitable to detect entanglement due to the nonGaussianity of subradiant states.Comment: 4 figure

Let’s Sit at the Table for women’s empowerment

We report on Let’s Sit at the Table, an ongoing series of seven (so far) roundtables launched in partnership by the Dubai based social enterprise Evolvin' Women and The Retreat Palm Dubai MGallery by Sofitel in September 2017. The roundtables were designed to explore best practices in the Gulf region driving women within the hospitality industry to senior leadership positions. Here we focus on one of the roundtables, which took place on February 21st, 2018 and was centered on the topic of empowering women in hospitality through education. The roundtable explored how to encourage women and girls to take up positions in fields where they lack representation, such as in the culinary arts. The roundtable was attended by ten experts in the areas of education and hospitality and revolved around several questions developed in line with the UN's Women Empowerment Principles (http://www.weprinciples.org/). To encourage further research we first briefly describe the problem as acknowledged in the academic literature and as experienced by one social enterprise in Dubai

Two quantum Simpson's paradoxes

The so-called Simpson's "paradox", or Yule-Simpson (YS) effect, occurs in classical statistics when the correlations that are present among different sets of samples are reversed if the sets are combined together, thus ignoring one or more lurking variables. Here we illustrate the occurrence of two analogue effects in quantum measurements. The first, which we term quantum-classical YS effect, may occur with quantum limited measurements and with lurking variables coming from the mixing of states, whereas the second, here referred to as quantum-quantum YS effect, may take place when coherent superpositions of quantum states are allowed. By analyzing quantum measurements on low dimensional systems (qubits and qutrits), we show that the two effects may occur independently, and that the quantum-quantum YS effect is more likely to occur than the corresponding quantum-classical one. We also found that there exist classes of superposition states for which the quantum-classical YS effect cannot occur for any measurement and, at the same time, the quantum-quantum YS effect takes place in a consistent fraction of the possible measurement settings. The occurrence of the effect in the presence of partial coherence is discussed as well as its possible implications for quantum hypothesis testing.Comment: published versio

Quantum estimation via minimum Kullback entropy principle

We address quantum estimation in situations where one has at disposal data from the measurement of an incomplete set of observables and some a priori information on the state itself. By expressing the a priori information in terms of a bias toward a given state the problem may be faced by minimizing the quantum relative entropy (Kullback entropy) with the constraint of reproducing the data. We exploit the resulting minimum Kullback entropy principle for the estimation of a quantum state from the measurement of a single observable, either from the sole mean value or from the complete probability distribution, and apply it as a tool for the estimation of weak Hamiltonian processes. Qubit and harmonic oscillator systems are analyzed in some details.Comment: 7 pages, slightly revised version, no figure

High efficiency tomographic reconstruction of quantum states by quantum nondemolition measurements

We propose a high efficiency tomographic scheme to reconstruct an unknown quantum state of the qubits by using a series of quantum nondemolition (QND) measurements. The proposed QND measurements of the qubits are implemented by probing the the stationary transmissions of the dispersively-coupled resonator. It is shown that only one kind of QND measurements is sufficient to determine all the diagonal elements of the density matrix of the detected quantum state. The remaining non-diagonal elements of the density matrix can be determined by other spectral measurements by beforehand transferring them to the diagonal locations using a series of unitary operations. Compared with the pervious tomographic reconstructions based on the usual destructively projective (DP) measurements (wherein one kind of such measurements could only determine one diagonal element of the density matrix), the present approach exhibits significantly high efficiency for N-qubit (N > 1). Specifically, our generic proposal is demonstrated by the experimental circuit-quantumelectrodynamics (circuit-QED) systems with a few Josephson charge qubits.Comment: 9pages,4figure