Microwave to optical photon conversion via fully concentrated rare-earth-ion crystals

Most investigations of rare-earth ions in solids for quantum information have used crystals where the rare-earth ion is a dopant. Here, we analyze the conversion of quantum information from microwave photons to optical frequencies using crystals where the rare-earth ions, rather than being dopants, are part of the host crystal. These concentrated crystals are attractive for frequency conversion because of their large ion densities and small linewidths. We show that conversion with both high efficiency and large bandwidth is possible in these crystals. In fact, the collective coupling between the rare-earth ions and the optical and microwave cavities is large enough that the limitation on the bandwidth of the devices will instead be the spacing between magnon modes in the crystal

Toward a PCR-Independent Molecular Diagnosis of Veterinary and Medically Relevant Pathogenic Organisms

Bloodstream infections caused by bacteria and fungi are a major problem worldwide. These bloodstream infections can affect both people and livestock, placing a significant burden upon developed and developing economies. In this paper we describe a multiplexed testing format, which can identify a range of bacteria and fungi within a single blood sample. Key to this technique is the specificity and sensitivity of the nucleotide probes that capture the sample. The sensitivity and specificity of the probes may allow detection of disease-causing microorganisms without the need for polymerase chain reaction amplification if the dynamics of probe binding can be observed in real time

Toward quantum microwave to optical conversion using rare earth ion containing crystals

With an Er:Y2SiO5 crystal at 4 K we achieve microwave to optical conversion with quantum efficiency 10-5. Theory and initial results at milli-kelvin temperatures and with fully concentrated rare earth crystals point to significant improvements

Comparison of ordinal versus Agatston coronary calcification scoring for cardiovascular disease mortality in community-living individuals

Coronary artery calcification (CAC) by the Agatston method predicts cardiovascular disease (CVD), but requires cardiac gated computed tomography (CT) scans, a procedure not covered by most insurance providers. An ordinal CAC score (scored 0-12 based on artery number and extent of calcification involvement) can be measured on standard chest CTs. However, the correlation of ordinal and Agatston CAC scores and their relative association with CVD mortality is uncertain, which we sought to determine. Nested case-control study. Community-living individuals undergoing "whole body" CT scans for preventive medicine. 4,544 consecutive patients with CT scans, were followed from 2000 to 2009. We selected cases who died of CVD (n = 57) and age, sex, and CT slice-thickness matched each case to three controls (N = 171). Cardiac gated 3 mm chest CTs and non-gated 6 mm standard chest CTs. CVD death over 9 years follow-up. The intra- and inter-reader kappa for the ordinal CAC score was 0.90 and 0.76 respectively. The correlation of Agatston and ordinal CAC scores was 0.72 (p < 0.001). In models adjusted for traditional CVD risk factors, the odds of CVD death per 1 SD greater CAC was 1.66 (1.03-2.68) using the ordinal CAC score and 1.57 (1.00-2.46) using the Agatston score. A simple ordinal CAC score is reproducible, strongly correlated with Agatston CAC scores, and provides similar prediction for CVD death in predominantly Caucasian community-living individuals

Analysis of the role of pglI in pilin glycosylation of Neisseria meningitidis

Pilin is the major subunit of the essential virulence factor pili and is glycosylated at Ser63. In this study we investigated the gene pglI to determine whether it is involved in the biosynthesis of the pilin-linked glycan of Neisseria meningitidis strain C311#3. A N. meningitidis C311#3pglI mutant resulted in a change of apparent molecular weight in SDS-PAGE and altered binding of antisera, consistent with a role in the biosynthesis of the pilin-linked glycan. These data, in conjunction with homology with well-characterised acyltransferases suggests a specific role for pglI in the biosynthesis of the basal 2,4-diacetamido-2,4,6-trideoxyhexose residue of the pilin-linked glycan. (C) 2004 Published by Elsevier B.V. on behalf of the Federation of European Microbiological Societies