On dynamical measures of quantum information

In this work, we use the theory of quantum states over time to define an entropy $S(\rho,\mathcal{E})$ associated with quantum processes $(\rho,\mathcal{E})$, where $\rho$ is a state and $\mathcal{E}$ is a quantum channel responsible for the dynamical evolution of $\rho$. The entropy $S(\rho,\mathcal{E})$ is a generalization of the von Neumann entropy in the sense that $S(\rho,\mathrm{id})=S(\rho)$ (where $\mathrm{id}$ denotes the identity channel), and is a dynamical analogue of the quantum joint entropy for bipartite states. Such an entropy is then used to define dynamical formulations of the quantum conditional entropy and quantum mutual information, and we show such information measures satisfy many desirable properties, such as a quantum entropic Bayes' rule. We also use our entropy function to quantify the information loss/gain associated with the dynamical evolution of quantum systems, which enables us to formulate a precise notion of information conservation for quantum processes.Comment: Comments welcome

From time-reversal symmetry to quantum Bayes' rules

Bayes' rule $\mathbb{P}(B|A)\mathbb{P}(A)=\mathbb{P}(A|B)\mathbb{P}(B)$ is one of the simplest yet most profound, ubiquitous, and far-reaching results of classical probability theory, with applications in any field utilizing statistical inference. Many attempts have been made to extend this rule to quantum systems, the significance of which we are only beginning to understand. In this work, we develop a systematic framework for defining Bayes' rule in the quantum setting, and we show that a vast majority of the proposed quantum Bayes' rules appearing in the literature are all instances of our definition. Moreover, our Bayes' rule is based upon a simple relationship between the notions of state over time and a time-reversal symmetry map, both of which are introduced here.Comment: Some adjustments and organizational changes, typos fixed, new tables added; 24 pages tota

Visualising urban sustainability

Developing sustainable urban environments is complex and requires a number of factors – including social, economic and environmental sustainability - to be taken into account. This project is prototype software that produces a 3D virtual model of urban developments allowing viewers to see the short and long-term implications of courses of action

Knowledge sharing in context: The case of volunteer development at a heritage site

© The Authors, 2017. This paper offers insights into the role and processes associated with knowledge sharing, as part of the development of volunteers at a substantial heritage site. The marked growth in the numbers and importance of volunteers in the heritage sector in the UK has fuelled interest and research in volunteer management, but researchers have paid little attention to the important area of the processes through which volunteers develop the skills and knowledge that they need to deliver their role. In order to contribute to addressing this gap, this paper reports on research conducted at a major heritage site in the UK. Data was gathered through onsite interviews with management and focus groups with volunteers. Questions explored the sources of knowledge utilised by volunteers, the knowledge sharing processes involved and how this contributed to their development. Whilst some managers are more committed to embedding learning opportunities in the everyday volunteering experience than others, and volunteers vary in their interest in developing new skills or transferring their existing knowledge and skills into their role as a volunteer, there is a general acknowledgement that knowledge sharing is pivotal to volunteer development. Informal learning was found to be the principal vehicle for the acquisition of knowledge by volunteers. This took place in many situations such as shared breaks, mentoring and community of practice situations, although the nature of volunteer roles determined the extent of social contact. Managers were fully aware of their critical role in knowledge sharing and attempted to facilitate such informal learning through formal and informal mentoring whilst also instigating some formal training and cascading information. Volunteers also took the initiative in setting up a dropbox for knowledge sharing, and in managing a social club, both of which they regarded as a vehicle for networking, informal learning and benchmarking. However, volunteers were less enthusiastic about the introduction of an intranet specifically for volunteers

Exploring the factors that influence knowledge sharing between academics.

The purpose of this paper is to investigate the impact of organisational and individual factors on the knowledge sharing behaviour of UK academics. Although there a few articles that explore knowledge sharing between academics in an Asian context, there is currently only one article that explores this topic in a UK context. Semi-structured interviews were conducted to gather insights into academics’ views on the factors that affect knowledge sharing. Purposive sampling was employed and a total of twelve academics were interviewed. Findings demonstrated that academics are prepared to share different types of knowledge; a range of organisational and individual factors affecting this process were highlighted by interviewees. Trust was discussed more than other individual factors, and was often associated with social exchange and reciprocal benefits. Culture was described by most interviewees as collaborative and the importance of physical location was stressed. Leaders were generally considered to have integrity, but often did not themselves share knowledge in a way that was visible to staff. Regular face-to-face contact was emphasised as a critical enabler for knowledge sharing. This study demonstrates there is a culture of trust in most departments and academics are willing to share knowledge with their colleagues. They do, however, believe that the matrix structure, that is typical of academic departments, has resulted in unclear roles and responsibilities, which could be a serious hindrance to designing structures to promote collaboration and sharing. Consideration should also be given to ensuring the availability of shared spaces to facilitate face-to-face contact between academics

Rho-associated kinase inhibitor eye drop (Ripasudil) transiently alters the morphology of corneal endothelial cells

PURPOSE: Ripasudil (Glanatec), a selective Rho-associated coiled coil-containing protein kinase (ROCK) inhibitor, was approved in Japan in September 2014 for the treatment of glaucoma and ocular hypertension. The purpose of this study was to investigate the effect of ripasudil eye drops on corneal endothelial morphology, as ROCK signaling is known to modulate the actin cytoskeleton. METHODS: Morphological changes in the corneal endothelium were evaluated in human subjects by specular and slit-lamp microscopy, following topical administration of ripasudil. We also used a rabbit model to evaluate the effect of ripasudil on clinical parameters of the corneal endothelium. Twenty-four hours after ripasudil application, corneal specimens were evaluated by phalloidin staining, immunohistochemical analysis, and electron microscopy. RESULTS: Specular microscopy revealed morphological changes in human eyes, and slit-lamp microscopy showed guttae-like findings. The rabbit model showed morphological changes similar to those seen in human eyes after ripasudil administration. Electron microscopy demonstrated that these alterations are due to the formation of protrusions along the cell-cell borders, but this formation is transient. Expression of corneal endothelial function-related markers was not disrupted; corneal thickness and corneal volume were not changed; and no cell death was observed following ripasudil administration. CONCLUSIONS: Ripasudil induces transient guttae-like findings in humans, most likely due to protrusion formation along intracellular borders caused by the reduction in actomyosin contractility of the corneal endothelial cells. No severe adverse effects were observed. Physicians should be aware that ROCK inhibitors can cause these guttae-like findings, to avoid misdiagnosing patients as having Fuchs endothelial corneal dystrophy. (www.umin.ac.jp/ctr number, UMIN000018340.)

Comparison of Dislocation Characterization by Electron Channeling Contrast Imaging and Cross-Correlation Electron Backscattered Diffraction

In this work, the relative capabilities and limitations of electron channeling contrast imaging (ECCI) and cross-correlation electron backscattered diffraction (CC-EBSD) have been assessed by studying the dislocation distributions resulting from nanoindentation in body centered cubic Ta. Qualitative comparison reveals very similar dislocation distributions between the CC-EBSD mapped GNDs and the ECC imaged dislocations. Approximate dislocation densities determined from ECC images compare well to those determined by CC-EBSD. Nevertheless, close examination reveals subtle differences in the details of the distributions mapped by these two approaches. The details of the dislocation Burgers vectors and line directions determined by ECCI have been compared to those determined using CC-EBSD and reveal good agreement

Emoticon convergence in Internet chat rooms

The present study examines sex and age differences in the use of emoticons (graphic representations of facial expressions) in Internet chat rooms. Data were collected from four Noesis chat rooms (‘18 plus’, ‘30-something’, ‘40- something’ and ‘50 plus’). Although women were more likely than men to use emoticons, there was no difference between the sexes in the range of emoticons used. The fact that men expressed a similar range of emoticons to women implies a general convergence towards female expression in mixed-sex communication contexts. Chat room users without a profile picture were also more likely to use winking emoticons. This may be because these types of emoticons are more flirtatious in intent, and it is easier for chatters to engage in risky communications when they are less identifiable. Furthermore, age had little bearing on the uptake of emoticons as well as the types of emoticons expressed. We draw upon Communication Accommodation Theory to help explain why emotional expression may converge in the chat room context

Individual Differences as Predictors of Social Networking

Research suggests that personality dictates specific Internet preferences. One area that remains relatively unexplored is the influence of personality on engagement with social networking sites (SNSs). The current study employs a ‘Uses and Gratifications’ framework to investigate whether personality, age, and sex predict motivations for using SNSs. The study explores both global and specific factors of personality using Eysenck's EPQ-R short form (extraversion, neuroticism and psychoticism) and Beck's SAS (sociotropy and autonomy). Principal component analysis identified ten distinct motivational components, which were then successfully predicted by individual differences through regression analyses. It is therefore suggested that individuals with different profiles vary in their motivations for using SNSs. Results support theoretical assumptions based on previous literature and personality dispositions

Investigating the Facebook experience through Q Methodology: Collective investment and a ‘Borg’ mentality

Several recent studies have explored social networking sites, such as Facebook, in light of the uses and gratifications approach. However, research has tended to ignore the latter part of this paradigm. This article uses Q methodology to explore user experiences of Facebook, allowing further exploration of gratification from site usage. Four distinct viewpoints were found: Facebook as a superficial environment; Facebook as a valid and valuable social environment; Facebook as an environment of surveillance; and Facebook as a destructive environment. Although the viewpoints show elements of user satisfaction, some users view Facebook in an almost entirely negative way. The article concludes by theorising a model of Facebook usage, drawing upon a metaphor from Star Trek, specifically an analogy with the Borg. It is argued that a level of ‘collective investment’ resides over social networks that may sometimes promote compliance