A New Symmetric Expression of Weyl Ordering

For the creation operator \adag and the annihilation operator $a$ of a harmonic oscillator, we consider Weyl ordering expression of (\adag a)^n and obtain a new symmetric expression of Weyl ordering w.r.t. \adag a \equiv N and a\adag =N+1 where $N$ is the number operator. Moreover, we interpret intertwining formulas of various orderings in view of the difference theory. Then we find that the noncommutative parameter corresponds to the increment of the difference operator w.r.t. variable $N$. Therefore, quantum (noncommutative) calculations of harmonic oscillators are done by classical (commutative) ones of the number operator by using the difference theory. As a by-product, nontrivial relations including the Stirling number of the first kind are also obtained.Comment: 15 pages, Latex2e, the title before replacement is "Orderings of Operators in Quantum Physics", new proofs by using a difference operator added, some references added, to appear in Modern Physics Letters

Associations between the combined physical activity environment, socioeconomic status, and 1 obesity: a cross-sectional study

Aims: This study investigates associations between the combined physical activity environment and obesity and explores any sub-group effects by individual-level socioeconomic status. Methods: In a large cross-sectional cohort (n = 22,889) from the Yorkshire Health Study, body mass index was calculated using self-reported height and weight and obesity was defined as a body mass index ≥ 30. The physical activity environment was split into ‘unfavourable physical activity’, ‘moderately favourable physical activity’ and ‘favourable physical activity’ environments. This was based on the count of parks and physical activity facilities within a 2 km radial buffer centred on home addresses. A favourable physical activity environment was defined as having ≥1 physical activity facility and ≥1 park, unfavourable as having no physical activity facility and park and any other combinations defined as moderately favourable. Logistic regression (odds ratios) identified associations with obesity. Results: Relative to ‘unfavourable physical activity environments’, individuals within favourable physical activity environments were less likely to be obese (odds ratio = 0.90; 95% confidence interval = 0.82–0.97), and there was no effect for moderately favourable environment. Furthermore, once stratified by education level, this relationship was only present for those of higher education. Conclusion: Our findings provide novel UK evidence and is one of the first papers internationally that highlights the importance of considering the interplay of individual-level socioeconomic factors when investigating associations between the physical activity environment and obesity

Measures of Hip Function and Symptoms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163446/2/acr24231_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163446/1/acr24231.pd

Quaternionic and Octonionic Spinors. A Classification

Quaternionic and octonionic realizations of Clifford algebras and spinors are classified and explicitly constructed in terms of recursive formulas. The most general free dynamics in arbitrary signature space-times for both quaternionic and octonionic spinors is presented. In the octonionic case we further provide a systematic list of results and tables expressing, e.g., the relations of the octonionic Clifford algebras with the $G_2$ cosets over the Lorentz algebras, the identities satisfied by the higher-rank antisymmetric octonionic tensors and so on. Applications of these results range from the classification of octonionic generalized supersymmetries, the construction of octonionic superstrings, as well as the investigations concerning the recently discovered octonionic $M$-superalgebra and its superconformal extension.Comment: 24 pages, LaTe

Dilaton as a Dark Matter Candidate and its Detection

Assuming that the dilaton is the dark matter of the universe, we propose an experiment to detect the relic dilaton using the electromagnetic resonant cavity, based on the dilaton-photon conversion in strong electromagnetic background. We calculate the density of the relic dilaton, and estimate the dilaton mass for which the dilaton becomes the dark matter of the universe. With this we calculate the dilaton detection power in the resonant cavity, and compare it with the axion detection power in similar resonant cavity experiment.Comment: 23 pages, 2 figure

Influence of association state and DNA binding on the O2-reactivity of [4Fe-4S] fumarate and nitrate reduction (FNR) regulator

The fumarate and nitrate reduction (FNR) regulator is the master switch for the transition between anaerobic and aerobic respiration in Escherichia coli. Reaction of dimeric [4Fe-4S] FNR with O2 results in conversion of the cluster into a [2Fe-2S] form, via a [3Fe-4S] intermediate, leading to the loss of DNA binding through dissociation of the dimer into monomers. In the present paper, we report studies of two previously identified variants of FNR, D154A and I151A, in which the form of the cluster is decoupled from the association state. In vivo studies of permanently dimeric D154A FNR show that DNA binding does not affect the rate of cluster incorporation into the apoprotein or the rate of O2-mediated cluster loss. In vitro studies show that O2-mediated cluster conversion for D154A and the permanent monomer I151A FNR is the same as in wild-type FNR, but with altered kinetics. Decoupling leads to an increase in the rate of the [3Fe-4S]1+ into [2Fe-2S]2+ conversion step, consistent with the suggestion that this step drives association state changes in the wild-type protein. We have also shown that DNA-bound FNR reacts more rapidly with O2 than FNR free in solution, implying that transcriptionally active FNR is the preferred target for reaction with O2

Synthetic poly(ester amine) and poly(amido amine) nanoparticles for efficient DNA and siRNA delivery to human endothelial cells

Biodegradable poly(ester amine) (PEA)-based and poly(amido amine) (PAA)-based nanoparticles were developed for efficient in vitro siRNA delivery to human umbilical vein endothelial cells (HUVECs). They were screened, characterized, and compared with traditionally studied DNA-containing particles. Several of the polymeric nanoparticles tested were found to be effective for delivering functional siRNA to green fluorescent protein (GFP) + HUVECs, achieving 60%–75% GFP knockdown while maintaining high viability. While PEAs have been used previously to form polyplexes or nanoparticles for DNA delivery, highly effective siRNA delivery in hard-to-transfect human cell types has not been previously reported. PEAs and linear nondendrimeric PAAs were also found to be effective for DNA delivery to HUVECs using GFP-encoding plasmid DNA (up to 50%–60% transfection efficiency). PEAs and PAAs can be separated into groups that form polymeric nanoparticles effective for siRNA delivery, for DNA delivery, or for both