Vacuum-stimulated cooling of single atoms in three dimensions

Taming quantum dynamical processes is the key to novel applications of quantum physics, e.g. in quantum information science. The control of light-matter interactions at the single-atom and single-photon level can be achieved in cavity quantum electrodynamics, in particular in the regime of strong coupling where atom and cavity form a single entity. In the optical domain, this requires permanent trapping and cooling of an atom in a micro-cavity. We have now realized three-dimensional cavity cooling and trapping for an orthogonal arrangement of cooling laser, trap laser and cavity vacuum. This leads to average single-atom trapping times exceeding 15 seconds, unprecedented for a strongly coupled atom under permanent observation.Comment: 4 pages, 4 figure

An optical fibre rereadable radiation dosimeter for use at high doses and at elevated temperature

A new type of radiation dosimeter for large radiation doses is described, which is based on silica fibre material. Conventional radioluminescence or thermoluminescence of silica produces emission in the blue region of the spectrum. However, in this new material irradiation, in conjunction with a heat treatment, generates a green emission band. The intensity of the green band can be monitored by either radioluminescence or thermoluminescence using a test dose. The signals are directly related to the total irradiation history of the material. The dosimeter is therefore rereadable. The production mechanism of the green emission centre requires a thermal processing stage, with an activation energy of 0.52 eV. Further, the dosimeter is effective at recording radiation during high-temperature exposure, to at least 400°C, with the subsequent dosimetry being performed below 200°C

Cystic Cervical Intramedullary Ependymoma with Previous lntracyst Hemorrhage: Magnetic Resonance Imaging at 1.5 T

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117483/1/jon199442111.pd

Theory of Photon Blockade by an Optical Cavity with One Trapped Atom

In our recent paper [1], we reported observations of photon blockade by one atom strongly coupled to an optical cavity. In support of these measurements, here we provide an expanded discussion of the general phenomenology of photon blockade as well as of the theoretical model and results that were presented in Ref. [1]. We describe the general condition for photon blockade in terms of the transmission coefficients for photon number states. For the atom-cavity system of Ref. [1], we present the model Hamiltonian and examine the relationship of the eigenvalues to the predicted intensity correlation function. We explore the effect of different driving mechanisms on the photon statistics. We also present additional corrections to the model to describe cavity birefringence and ac-Stark shifts. [1] K. M. Birnbaum, A. Boca, R. Miller, A. D. Boozer, T. E. Northup, and H. J. Kimble, Nature 436, 87 (2005).Comment: 10 pages, 6 figure

Shaping the Phase of a Single Photon

While the phase of a coherent light field can be precisely known, the phase of the individual photons that create this field, considered individually, cannot. Phase changes within single-photon wave packets, however, have observable effects. In fact, actively controlling the phase of individual photons has been identified as a powerful resource for quantum communication protocols. Here we demonstrate the arbitrary phase control of a single photon. The phase modulation is applied without affecting the photon's amplitude profile and is verified via a two-photon quantum interference measurement, which can result in the fermionic spatial behaviour of photon pairs. Combined with previously demonstrated control of a single photon's amplitude, frequency, and polarisation, the fully deterministic phase shaping presented here allows for the complete control of single-photon wave packets.Comment: 4 pages, 4 figure

Traditional and emerging indicators of cardiovascular risk in chronic obstructive pulmonary disease

With the increased cardiovascular (CV) morbidity and mortality in subjects with chronic obstructive pulmonary disease (COPD), there is a priority to identify those patients at increased risk of cardiovascular disease. Stable patients with COPD (n = 185) and controls with a smoking history (n = 106) underwent aortic pulse wave velocity (PWV), blood pressure (BP) and skin autofluorescence (AF) at clinical stability. Blood was sent for fasting lipids, soluble receptor for advanced glycation end products (sRAGE) and CV risk prediction scores were calculated. More patients (18%) had a self-reported history of CV disease than controls (8%), p = 0.02, whilst diabetes was similar (14% and 10%), p = 0.44. Mean (SD) skin AF was greater in patients: 3.1 (0.5) AU than controls 2.8 (0.6) AU, p < 0.001. Aortic PWV was greater in patients: 10.2 (2.3) m/s than controls: 9.6 (2.0) m/s, p = 0.02 despite similar BP. The CV risk prediction scores did not differentiate between patients and controls nor were the individual components of the scores different. The sRAGE levels were not statistically different. We present different indicators of CV risk alongside each other in well-defined subjects with and without COPD. Two non-invasive biomarkers associated with future CV burden: skin AF and aortic PWV are both significantly greater in patients with COPD compared to the controls. The traditional CV prediction scores used in the general population were not statistically different. We provide new data to suggest that alternative approaches for optimal CV risk detection should be employed in COPD management

Impact of Coexisting Dementia on Inpatient Outcomes for Patients Admitted with a COPD Exacerbation

Purpose: People with COPD are at a higher risk of cognitive dysfunction than the general population. However, the additional impact of dementia amongst such patients is not well understood, particularly in those admitted with a COPD exacerbation. We assessed the impact of coexisting dementia on inpatient mortality and length of stay (LOS) in patients admitted to hospital with a COPD exacerbation, using the United States based National Inpatient Sample database.Patients and Methods: Patients aged over 40 years and hospitalised with a primary diagnosis of COPD exacerbation from 2011 to 2015 were included. Cases were grouped into patients with and without dementia. Multivariable logistic regression analysis, stratified by age, was used to assess risk of inpatient deaths. Cox regression was carried out to compare death rates and competing risk analysis gave estimates of discharge rates with time to death a competing variable.Results: A total of 576,381 patients were included into the analysis, of which 35,372 (6.1%) had co-existent dementia. There were 6413 (1.1%) deaths recorded. The odds of inpatient death were significantly greater in younger patients with dementia (41– 64 years) [OR (95% CI) dementia vs without: 1.75 (1.04– 2.92), p=0.03]. Cases with dementia also had a higher inpatient mortality rate in the first 4 days [HR (95% CI) dementia vs without: 1.23 (1.08– 1.41), p=0.002] and a longer LOS [sub-hazard ratio (95% CI) dementia vs without: 0.93 (0.92– 0.94), p< 0.001].Conclusion: Dementia as a comorbidity is associated with worse outcomes based on inpatient deaths and LOS in patients admitted with COPD exacerbations

Photoluminescence of single colour defects in 50 nm diamond nanocrystals

We used optical confocal microscopy to study optical properties of diamond 50 nm nanocrystals first irradiated with an electron beam, then dispersed as a colloidal solution and finally deposited on a silica slide. At room temperature, under CW laser excitation at a wavelength of 514.5 nm we observed perfectly photostable single Nitrogen-Vacancy (NV) colour defects embedded in the nanocrystals. From the zero-phonon line around 575 nm in the spectrum of emitted light, we infer a neutral NV0 type of defect. Such nanoparticle with intrinsic fluorescence are highly promising for applications in biology where long-term emitting fluorescent bio-compatible nanoprobes are still missing.Comment: proceedings of ICDS 23 conference (23rd International Conference on Defects in Semiconductors, July 24 - July 29, 2005, Awaji Island, Hyogo, Japan); to appear in "Physica B

Messy entanglements: research assemblages in heart transplantation discourses and practices

The paper engages with a variety of data around a supposedly single biomedical event, that of heart transplantation. In conventional discourse, organ transplantation constitutes an unproblematised form of spare part surgery in which failing biological components are replaced by more efficient and enduring ones, but once that simple picture is complicated by employing a radically interdisciplinary approach, any biomedical certainty is profoundly disrupted. Our aim, as a cross-sectorial partnership, has been to explore the complexities of heart transplantation by explicitly entangling research from the arts, biosciences and humanities without privileging any one discourse. It has been no easy enterprise yet it has been highly productive of new insights. We draw on our own ongoing funded research with both heart donor families and recipients to explore our different perceptions of what constitutes data and to demonstrate how the dynamic entangling of multiple data produces a constitutive assemblage of elements in which no one can claim priority. Our claim is that the use of such research assemblages and the collaborations that we bring to our project breaks through disciplinary silos to enable a fuller comprehension of the significance and experience of heart transplantation in both theory and practice