Two-qubit non-Markovianity induced by a common environment

We study non-Markovianity as backflow of information in two-qubit systems. We consider a setting where, by changing the distance between the qubits, one can interpolate between independent reservoir and common reservoir scenarios. We demonstrate that non-Markovianity can be induced by the common reservoir and single out the physical origin of this phenomenon. We show that two-qubit non-Markovianity coincides with instances of non-divisibility of the corresponding dynamical map, and we discuss the pair of states maximizing information flowback. We also discuss the issue of additivity for the measure we use and in doing so, give an indication of its usefulness as a resource for multipartite quantum systems.Comment: 9 pages, 5 figures, Published version with minor modification

A Feature-Augmented Grammar for Automated Media Production

The IST Polymnia project is creating a fully automated system for personalised video generation, including content creation, selection and composition. This paper presents a linguistically motivated solution using context-free feature-augmented grammar rules to describe editing tasks and hence automate video editing. The solution is media and application independent

An Integrated Content and Metadata based Retrieval System for Art

In this paper we describe aspects of the Artiste project to develop a distributed content and metadata based analysis, retrieval and navigation system for a number of major European Museums. In particular, after a brief overview of the complete system, we describe the design and evaluation of some of the image analysis algorithms developed to meet the specific requirements of the users from the museums. These include a method for retrievals based on sub images, retrievals based on very low quality images and retrieval using craquelure type

Dietary values of wild and semi-wild edible plants in Southern Ethiopia

Ethnobotanical studies have shown that many wild plant species are sporadically consumed alongside regular food sources in developing countries. Many plants of wild and semi-wild origin are consumed in the remote parts of southern Ethiopia. Dietetic values of Ethiopia’s non-crop food plants, though important in prevention of malnutrition and contribution to food security, remains shrouded for lack of chemical information. The chemical composition of popularly used wild edibles in Hamar and Konso (Xonso) of southern Ethiopia was examined. The most preferred 15 semi-wild and wild edible plants were selected using a mix of standard ethnobotanical field methods. Edible parts of target plants were collected with local participants, lyophilized and analyzed for proximate composition, amino acids, minerals and anti-nutritional factors. The wild edibles constituted good amounts of nutrients essential in human diet. Green leafy vegetables (GLVs) gave 1.5-5.8% ether extractives and total mineral composition of 12.5%-25.6%; Ca being highest (1100 - 3419 mg %) and exceptionally high for Justicia ladanoides (6177 mg %). Fe, Mg, Mn and Zn ranged from 11.7-23.14, 175-2049, 3.4-9.9 and 1.2-3.3 mg %, respectively. All GLVs contained ≥20% protein, highest in Coccinia grandis (36.3%). The latter species and Trigonella foenum-graecum yielded high lysine level. Anti-nutrients of concern include phenolics (158-1564 mg %) and tannins (448-2254 mg %) in GLVs and phenolics (1997mg %) and tannins (6314 mg %) in Ximenia caffra fruits. Total oxalates in mg % were high in Amaranthus graecizans (14067), Celosia argentea (12706) and Portulaca quadrifida (10162). Bulk consumption of monotype edible plant part in one meal may lead to nutritional and health impairment. However, traditional processing methods lower most of the anti-nutritionals and their respective risks. New food composition tables that integrate indigenous knowledge and nutritional content of the semi-wild and wild edibles are recommended. Wild edibles can be considered to improve livelihood security and reduce malnutrition in tune with the Millennium Development Goals aimed at reducing poverty and hunger

Remembering what could have happened: Neural correlates of episodic counterfactual thinking

Recent evidence suggests that our capacities to remember the past and to imagine what might happen in the future largely depend on the same core brain network that includes the middle temporal lobe, the posterior cingulate/retrosplenial cortex, the inferior parietal lobe, the medial prefrontal cortex, and the lateral temporal cortex. However, the extent to which regions of this core brain network are also responsible for our capacity to think about what could have happened in our past, yet did not occur (i.e., episodic counterfactual thinking), is still unknown. The present study examined this issue. Using a variation of the experimental recombination paradigm (Addis, Pan, Vu, Laiser, & Schacter, 2009. Neuropsychologia. 47: 2222–2238), participants were asked both to remember personal past events and to envision alternative outcomes to such events while undergoing functional magnetic resonance imaging. Three sets of analyses were performed on the imaging data in order to investigate two related issues. First, a mean-centered spatiotemporal partial least square (PLS) analysis identified a pattern of brain activity across regions of the core network that was common to episodic memory and episodic counterfactual thinking. Second, a non-rotated PLS analysis identified two different patterns of brain activity for likely and unlikely episodic counterfactual thoughts, with the former showing significant overlap with the set of regions engaged during episodic recollection. Finally, a parametric modulation was conducted to explore the differential engagement of brain regions during counterfactual thinking, revealing that areas such as the parahippocampal gyrus and the right hippocampus were modulated by the subjective likelihood of counterfactual simulations. These results suggest that episodic counterfactual thinking engages regions that form the core brain network, and also that the subjective likelihood of our counterfactual thoughts modulates the engagement of different areas within this set of regions.Psycholog

Re-imagining the future:repetition decreases hippocampal involvement in future simulation

Imagining or simulating future events has been shown to activate the anterior right hippocampus (RHC) more than remembering past events does. One fundamental difference between simulation and memory is that imagining future scenarios requires a more extensive constructive process than remembering past experiences does. Indeed, studies in which this constructive element is reduced or eliminated by “pre-imagining” events in a prior session do not report differential RHC activity during simulation. In this fMRI study, we examined the effects of repeatedly simulating an event on neural activity. During scanning, participants imagined 60 future events; each event was simulated three times. Activation in the RHC showed a significant linear decrease across repetitions, as did other neural regions typically associated with simulation. Importantly, such decreases in activation could not be explained by non-specific linear time-dependent effects, with no reductions in activity evident for the control task across similar time intervals. Moreover, the anterior RHC exhibited significant functional connectivity with the whole-brain network during the first, but not second and third simulations of future events. There was also evidence of a linear increase in activity across repetitions in right ventral precuneus, right posterior cingulate and left anterior prefrontal cortex, which may reflect source recognition and retrieval of internally generated contextual details. Overall, our findings demonstrate that repeatedly imagining future events has a decremental effect on activation of the hippocampus and many other regions engaged by the initial construction of the simulation, possibly reflecting the decreasing novelty of simulations across repetitions, and therefore is an important consideration in the design of future studies examining simulation