Exact master equation for a noncommutative Brownian particle

We derive the Hu-Paz-Zhang master equation for a Brownian particle linearly coupled to a bath of harmonic oscillators on the plane with spatial noncommutativity. The results obtained are exact to all orders in the noncommutative parameter. As a by-product we derive some miscellaneous results such as the equilibrium Wigner distribution for the reservoir of noncommutative oscillators, the weak coupling limit of the master equation and a set of sufficient conditions for strict purity decrease of the Brownian particle. Finally, we consider a high-temperature Ohmic model and obtain an estimate for the time scale of the transition from noncommutative to ordinary quantum mechanics. This scale is considerably smaller than the decoherence scale.Comment: Latex file, 28 pages, Published versio

The Power-Sharing Event Dataset (PSED): a new dataset on the promises and practices of power-sharing in post-conflict countries

Past research on the relationship between power-sharing arrangements and the recurrence of civil conflict has primarily analyzed the promises of power-sharing stipulated in peace agreements. What happens afterwards, however, has not yet been sufficiently explored. This represents a major research gap, as the actual practices of power-sharing in post-conflict countries are likely to be influential in the possibility of civil conflict recurring. To address this shortcoming, we present a new global dataset on the promises and practices of power-sharing between the government of a state and former rebels in post-conflict countries. The collected data captures if, when and how power-sharing institutions have been promised and/or put into place, and whether they have subsequently been modified or abolished. The dataset encompasses every peace agreement signed after the cessation of a civil conflict in the years between 1989 and 2006, and covers a five-year period after the signature of each of these agreements (unless violence recurred earlier). The unit of analysis is the government–rebel dyad during the post-conflict period and data is recorded in an event data format. A first analysis of the Power-Sharing Event Dataset (PSED) reveals that the effects of the promises of power-sharing on civil conflict recurrence follow a different logic than the effects of their practices. This finding emphasizes the necessity for in-depth analyses of post-conflict situations for which the PSED provides the necessary data

Perspective from a Younger Generation -- The Astro-Spectroscopy of Gisbert Winnewisser

Gisbert Winnewisser's astronomical career was practically coextensive with the whole development of molecular radio astronomy. Here I would like to pick out a few of his many contributions, which I, personally, find particularly interesting and put them in the context of newer results.Comment: 14 pages. (Co)authored by members of the MPIfR (Sub)millimeter Astronomy Group. To appear in the Proceedings of the 4th Cologne-Bonn-Zermatt-Symposium "The Dense Interstellar Medium in Galaxies" eds. S. Pfalzner, C. Kramer, C. Straubmeier, & A. Heithausen (Springer: Berlin

Nuisance

This essay sets out the law and the economic theory of nuisance. Nuisance law serves a regulatory function: it induces actors to choose the socially preferred level of an activity by imposing liability when the externalized costs of the activity are substantially greater than the externalized benefits or not reciprocal to other background external costs. Proximate cause doctrine plays a role in supplementing nuisance law

TLR7-mediated skin inflammation remotely triggers chemokine expression and leukocyte accumulation in the brain

Background: The relationship between the brain and the immune system has become increasingly topical as, although it is immune-specialised, the CNS is not free from the influences of the immune system. Recent data indicate that peripheral immune stimulation can significantly affect the CNS. But the mechanisms underpinning this relationship remain unclear. The standard approach to understanding this relationship has relied on systemic immune activation using bacterial components, finding that immune mediators, such as cytokines, can have a significant effect on brain function and behaviour. More rarely have studies used disease models that are representative of human disorders. Methods: Here we use a well-characterised animal model of psoriasis-like skin inflammation—imiquimod—to investigate the effects of tissue-specific peripheral inflammation on the brain. We used full genome array, flow cytometry analysis of immune cell infiltration, doublecortin staining for neural precursor cells and a behavioural read-out exploiting natural burrowing behaviour. Results: We found that a number of genes are upregulated in the brain following treatment, amongst which is a subset of inflammatory chemokines (CCL3, CCL5, CCL9, CXCL10, CXCL13, CXCL16 and CCR5). Strikingly, this model induced the infiltration of a number of immune cell subsets into the brain parenchyma, including T cells, NK cells and myeloid cells, along with a reduction in neurogenesis and a suppression of burrowing activity. Conclusions: These findings demonstrate that cutaneous, peripheral immune stimulation is associated with significant leukocyte infiltration into the brain and suggest that chemokines may be amongst the key mediators driving this response

Sickle cell trait and priapism: a case report and review of the literature

Background A 32 year-old African-American man presented to our institution after attempting suicide via ingestion with quetiapine. He had reported a history of several days of substance abuse with alcohol, cocaine and marijuana related to a partying binge. Following this, his partner removed him from his residence resulting in a suicide attempt. During hospitalization the patient developed priapism, a condition he had not experienced before. Case presentation Given this was his first time with priapism, an extensive work-up revealed the patient had previously undiagnosed sickle cell trait, which we postulate to have been a significant factor in his development of acute priapism. Sickle cell trait is considered to be a generally benign condition except for a few rare complications under more demanding physical conditions. However, upon reviewing the literature on the association of sickle cell trait with priapism, we believe this may not be the case. Case reports and small series that appeared in the 1960s and 1970s indicated an association between priapism and sickle trait. Little has been reported recently, and the general teaching regarding sickle cell trait does not include this information. However, one case was reported with the use of phosphodiesterase-5 (PDE-5) inhibitors and the development of priapism in a patient with sickle cell trait. These medications are now first line treatment in erectile dysfunction. They act by enhancing nitric oxide (NO) production leading to relaxation of smooth muscle in the corpora cavernosa and penile arteries. Conclusion Priapism was not reported in the initial studies of these medications. Further review of the literature indicates this may be a complex relationship. Interestingly, PDE5 inhibitors also have been postulated to be protective in sickle cell disease and perhaps also sickle cell trait because priapism might be caused by reduced NO availability. In this article, we examine the evidence linking sickle cell trait to priapism, explore the implications of PDE5 use, particularly in the setting of sickle cell trait, and propose that teaching about sickle cell trait include a discussion of priapism risk

Shining Light on Merging Galaxies I: The Ongoing Merger of a Quasar with a `Green Valley' Galaxy

Serendipitous observations of a pair z = 0.37 interacting galaxies (one hosting a quasar) show a massive gaseous bridge of material connecting the two objects. This bridge is photoionized by the quasar (QSO) revealing gas along the entire projected 38 kpc sightline connecting the two galaxies. The emission lines that result give an unprecedented opportunity to study the merger process at this redshift. We determine the kinematics, ionization parameter (log U ~ -2.5 +- 0.03), column density (N_H ~ 10^{21} cm^{-2}), metallicity ([M/H] ~ -0.20 +- 0.15), and mass (~ 10^8 Msun) of the gaseous bridge. We simultaneously constrain properties of the QSO-host (M_DM>8.8x 10^{11} Msun) and its companion galaxy (M_DM>2.1 x 10^{11} Msun; M_star ~ 2 x 10^{10} Msun; stellar burst age=300-800 Myr; SFR~6 Msun/yr; and metallicity 12+log (O/H)= 8.64 +- 0.2). The general properties of this system match the standard paradigm of a galaxy-galaxy merger caught between first and second passage while one of the galaxies hosts an active quasar. The companion galaxy lies in the so-called `green valley', with a stellar population consistent with a recent starburst triggered during the first passage of the merger and has no detectable AGN activity. In addition to providing case-studies of quasars associated with galaxy mergers, quasar/galaxy pairs with QSO-photoionized tidal bridges such as this one offer unique insights into the galaxy properties while also distinguishing an important and inadequately understood phase of galaxy evolution.Comment: 23 pages, 12 figures, 5 tables, Submitted to ApJ, revised to address referee's comment

The Hidden Curriculum of Veterinary Education: Mediators and Moderators of Its Effects

The “hidden curriculum” has long been supposed to have an effect on students' learning during their clinical education, and in particular in shaping their ideas of what it means to be a professional. Despite this, there has been little evidence linking specific changes in professional attitudes to the individual components of the hidden curriculum. This study aimed to recognize those components that led to a change in students' professional attitudes at a UK veterinary school, as well as to identify the attitudes most affected. Observations were made of 11 student groups across five clinical rotations, followed by semi-structured interviews with 23 students at the end of their rotation experience. Data were combined and analyzed thematically, taking both an inductive and deductive approach. Views about the importance of technical competence and communication skills were promoted as a result of students' interaction with the hidden curriculum, and tensions were revealed in relation to their attitudes toward compassion and empathy, autonomy and responsibility, and lifestyle ethic. The assessment processes of rotations and the clinical service organization served to communicate the messages of the hidden curriculum, bringing about changes in student professional attitudes, while student-selected role models and the student rotation groups moderated the effects of these influences

Improving the normalization of complex interventions: measure development based on normalization process theory (NoMAD): study protocol

<b>Background</b> Understanding implementation processes is key to ensuring that complex interventions in healthcare are taken up in practice and thus maximize intended benefits for service provision and (ultimately) care to patients. Normalization Process Theory (NPT) provides a framework for understanding how a new intervention becomes part of normal practice. This study aims to develop and validate simple generic tools derived from NPT, to be used to improve the implementation of complex healthcare interventions.<p></p> <b>Objectives</b> The objectives of this study are to: develop a set of NPT-based measures and formatively evaluate their use for identifying implementation problems and monitoring progress; conduct preliminary evaluation of these measures across a range of interventions and contexts, and identify factors that affect this process; explore the utility of these measures for predicting outcomes; and develop an online users’ manual for the measures.<p></p> <b>Methods</b> A combination of qualitative (workshops, item development, user feedback, cognitive interviews) and quantitative (survey) methods will be used to develop NPT measures, and test the utility of the measures in six healthcare intervention settings.<p></p> <b>Discussion</b> The measures developed in the study will be available for use by those involved in planning, implementing, and evaluating complex interventions in healthcare and have the potential to enhance the chances of their implementation, leading to sustained changes in working practices

Neurogenomic Evidence for a Shared Mechanism of the Antidepressant Effects of Exercise and Chronic Fluoxetine in Mice

Several different interventions improve depressed mood, including medication and environmental factors such as regular physical exercise. The molecular pathways underlying these effects are still not fully understood. In this study, we sought to identify shared mechanisms underlying antidepressant interventions. We studied three groups of mice: mice treated with a widely used antidepressant drug – fluoxetine, mice engaged in voluntary exercise, and mice living in an enriched environment. The hippocampi of treated mice were investigated at the molecular and cellular levels. Mice treated with fluoxetine and mice who exercised daily showed, not only similar antidepressant behavior, but also similar changes in gene expression and hippocampal neurons. These changes were not observed in mice with environmental enrichment. An increase in neurogenesis and dendritic spine density was observed following four weeks of fluoxetine treatment and voluntary exercise. A weighted gene co-expression network analysis revealed four different modules of co-expressed genes that were correlated with the antidepressant effect. This network analysis enabled us to identify genes involved in the molecular pathways underlying the effects of fluoxetine and exercise. The existence of both neuronal and gene expression changes common to antidepressant drug and exercise suggests a shared mechanism underlying their effect. Further studies of these findings may be used to uncover the molecular mechanisms of depression, and to identify new avenues of therapy