Joint measurements and Bell inequalities

Joint quantum measurements of noncommuting observables are possible, if one accepts an increase in the measured variances. A necessary condition for a joint measurement to be possible is that a joint probability distribution exists for the measurement. This fact suggests that there may be a link with Bell inequalities, as these will be satisfied if and only if a joint probability distribution for all involved observables exists. We investigate the connections between Bell inequalities and conditions for joint quantum measurements to be possible. Mermin's inequality for the three-particle Greenberger-Horne-Zeilinger state turns out to be equivalent to the condition for a joint measurement on two out of the three quantum systems to exist. Gisin's Bell inequality for three coplanar measurement directions, meanwhile, is shown to be less strict than the condition for the corresponding joint measurement.

The structural organization of aurein precursor cDNAs from the skin secretion of the Australian green and golden bell frog, Litoria aurea.

Aureins are a family of peptides (13-25 residues), some of which possess potent antimicrobial and anti-cancer properties, which have been classified into 5 subgroups based upon primary structural similarities. They were originally isolated from the defensive skin secretions of the closely related Australian bell frogs, Litoria aurea and Litoria raniformis, and of the 23 aurein peptides identified, 10 are common to both species. Using a recently developed technique, we have constructed a cDNA library from the defensive secretion of the green and golden bell frog, L. aurea, and successfully cloned a range of aurein precursor transcripts containing entire open-reading frames. All open-reading frames consisted of a putative signal peptide and an acidic pro-region followed by a single copy of aurein. The deduced precursor structures for the most active aureins (2.2 and 3.1) confirmed the presence of a C-terminal amidation motif whereas that of aurein 5.3 did not. Processed peptides corresponding in molecular mass to aureins 2.2, 2.3, 2.5, 3.1 and 5.3 were identified in the same secretion sample using LC/MS. The application of this technique thus permits parallel peptidomic and transcriptomic analyses on the same lyophilized skin secretion sample circumventing sacrifice of specimens of endangered herpetofauna.

Violations of Bell's inequality for Gaussian states with homodyne detection and nonlinear interactions

We show that homodyne measurements can be used to demonstrate violations of Bell's inequality with Gaussian states, when the local rotations used for these types of tests are implemented using nonlinear unitary operations. We reveal that the local structure of the Gaussian state under scrutiny is crucial in the performance of the test. The effects of finite detection efficiency are thoroughly studied and shown to only mildly affect the revelation of Bell violations. We speculate that our approach may be extended to other applications such as entanglement distillation where local operations are necessary elements besides quantum entanglement.

First record of minimum Irish hare (Lepus timidus hibernicus Bell 1837) longevity in the wild.

Average longevity of the mountain hare (Lepus timidus L., 1758) has been estimated at nine years in the wild (Macdonald D. and Barrett, P. 1993 Mammals of Britain and Europe. Harper Collins Publishers, London) with a maximum recorded age of 18 years for one marked animal (Angerbjörn, A. and Flux, J. E. C. 1995 Lepus timidus. Mammalian Species 495: 1–11). However, the longevity of the Irish hare (L. t. hibernicus Bell 1837) is entirely unknown. A total of 14 Irish hares was trapped and tagged at Belfast International Airport, Co. Antrim from February to April 2005. The sex, age (juvenile or adult) and weight of each animal were recorded. Adults were taken as those individuals >8-10 months old defined by the fusing of the notch between the apophysis and diaphysis of the tibia and humerus (Flux, J. E. C. 1970 Journal of Zoology 161: 75-123). Individual identification was made by a system of colourcoded ear tags (Roxan iD Ltd. Selkirk, Scotland) being inserted in the centre of the pinna of each ear. Each ear tag (6 × 34 mm) and puncture site was disinfected with 70 per cent ethanol prior to insertion. An adult male, #001/002 ‘Blue/Blue’, was tagged on 3 March 2005 weighing 3.8 kg and was sighted during a return site visit on 4 April 2007. An adult female, #026/003 ‘Green/Yellow’, was tagged on 15 April 2005 weighing 4.0 kg and was sighted during return visits on 25 March 2010 and 19 October 2010. The latest possible date of birth for both individuals was spring/summer 2004. Consequently, they were at least 3 years and 6.5 years old, respectively. This is the first record of minimum Irish hare longevity in the wild. These observations suggest that ear tagging does not compromise animal welfare and is an effective means of long-term monitoring. Future research may utilize capture-mark-recapture methods.

Risk factors for clinical coronary heart disease in systemic lupus erythematosus: the lupus and atherosclerosis evaluation of risk (LASER) study.

Abstract OBJECTIVE: Accelerated atherosclerosis and premature coronary heart disease (CHD) are recognized complications of systemic lupus erythematosus (SLE), but the exact etiology remains unclear and is likely to be multifactorial. We hypothesized that SLE patients with CHD have increased exposure to traditional risk factors as well as differing disease phenotype and therapy-related factors compared to SLE patients free of CHD. Our aim was to examine risk factors for development of clinical CHD in SLE in the clinical setting. METHODS: In a UK-wide multicenter retrospective case-control study we recruited 53 SLE patients with verified clinical CHD (myocardial infarction or angina pectoris) and 96 SLE patients without clinical CHD. Controls were recruited from the same center as the case and matched by disease duration. Charts were reviewed up to time of event for cases, or the same "dummy-date" in controls. RESULTS: SLE patients with clinical CHD were older at the time of event [mean (SD) 53 (10) vs 42 (10) yrs; p

Raman spectroelectrochemical studies and crystal structure of a binuclear copper(I) complex with a bridging diimine ligand

Raman spectroelectrochemical and X-ray crystallographic studies have been made for the binuclear copper(I) complex, [(Ph(3)P)(2)Cu(dpq)Cu(PPh(3))(2)][BF4](2), where dpq is the bridging ligand 2,3-di(2-pyridyl)quinoxaline. The X-ray data show that the pyridine rings are twisted out of plane with respect to the quinoxaline ring which is itself non-planar. The UV/VIS spectra of the metal-to-ligand charge-transfer excited state and those of the electrochemically reduced complex are similar. The resonance-Raman spectrum of the latter species exhibits little change in the frequency of the pyridinylquinoxaline inter-ring C-C bond stretching mode, compared to the ground electronic state. This suggests minimum change in the inter-ring C-C bond order in the electrochemically or charge-transfer generated radical anion. Semiempirical molecular-orbital calculations on both the neutral dpq and radical anion show two near-degenerate lowest unoccupied orbitals in the neutral species. One is strongly bonding across the inter-ring C-C bond while the other is almost nun-bonding. The Raman data suggest that it is this latter orbital which is populated in the transient and electrochemical experiments.

TRANSIENT RESONANCE RAMAN AND RAMAN SPECTROELECTROCHEMICAL STUDIES OF CUI COMPLEXES WITH POLYPYRIDYL LIGANDS

Studies by laser flash photolysis, transient Raman spectroscopy, and Raman and UV-vis spectroelectrochemistry are described in which the techniques have been used in parallel to compare the lowest energy charge-transfer excited states of Cu (1) complexes ([Cu(L)2]+ and [ (PPh3)2Cu(L)]+ [L = 2,2'-biquinoline (BIQ) or 6,7-dihydro-5,8-dimethyldibenzo[b,j] [1,10]-phenanthroline (DMCH)) with the species produced by electrochemical reduction in the same group of complexes. Transient resonance Raman spectra for the metal-to-ligand charge-transfer (MLCT) states of [Cu(DMCH)2]+ (1), [Cu(BIQ)2]+ (2), [Cu(DMCH)(PPh3)2]+ (3), and [Cu(BIQ)(PPh3)2]+ (4) are compared with the resonance Raman spectra of the same group of complexes following one-electron electrochemical reduction of the DMCH and BIQ ligands. The UV-vis and resonance Raman evidence suggests that the electrochemical reduction of the [Cu(I)L2]+ species proceeds according to the sequence [LCu(I)L]+ -->e- [LCu0L] -->e- [L.-Cu(I)L.-]-. Several features assignable to modes of the electrochemically generated DMCH.-and BIQ'- radical anions exhibit a close correspondence in both frequency and relative intensity with counterparts in the spectra of the MLCT states of 1 and 2. A notable exception is a band near 1590 cm-1 in the spectra of the electrochemically reduced species which occurs some 15 cm-1 lower in the corresponding spectra of the excited-state species. It is suggested that the shift may reflect the change in oxidation state of the metal center from Cu(I) to Cu(II) which occurs as a result of charge-transfer excitation.