Universally valid reformulation of the Heisenberg uncertainty principle on noise and disturbance in measurement

The Heisenberg uncertainty principle states that the product of the noise in a position measurement and the momentum disturbance caused by that measurement should be no less than the limit set by Planck's constant, hbar/2, as demonstrated by Heisenberg's thought experiment using a gamma-ray microscope. Here I show that this common assumption is false: a universally valid trade-off relation between the noise and the disturbance has an additional correlation term, which is redundant when the intervention brought by the measurement is independent of the measured object, but which allows the noise-disturbance product much below Planck's constant when the intervention is dependent. A model of measuring interaction with dependent intervention shows that Heisenberg's lower bound for the noise-disturbance product is violated even by a nearly nondisturbing, precise position measuring instrument. An experimental implementation is also proposed to realize the above model in the context of optical quadrature measurement with currently available linear optical devices.Comment: Revtex, 6 page

Higher bone resorption excretion in South Asian women vs. White Caucasians and increased bone loss with higher seasonal cycling of vitamin D: Results from the D-FINES cohort study

Few data exist on bone turnover in South Asian women and it is not well elucidated as to whether Western dwelling South Asian women have different bone resorption levels to that of women from European ethnic backgrounds. This study assessed bone resorption levels in UK dwelling South Asian and Caucasian women as well as evaluating whether seasonal variation in 25-hydroxyvitamin D [25(OH)D] is associated with bone resorption in either ethnic group. Data for seasonal measures of urinary N-telopeptide of collagen (uNTX) and serum 25(OH)D were analysed from n = 373 women (four groups; South Asian postmenopausal n = 44, South Asian premenopausal n = 50, Caucasian postmenopausal n = 144, Caucasian premenopausal n = 135) (mean (± SD) age 48 (14) years; age range 18–79 years) who participated in the longitudinal D-FINES (Diet, Food Intake, Nutrition and Exposure to the Sun in Southern England) cohort study (2006–2007). A mixed between-within subjects ANOVA (n = 192) showed a between subjects effect of the four groups (P < 0.001) on uNTX concentration, but no significant main effect of season (P = 0.163). Bonferroni adjusted Post hoc tests (P ≤ 0.008) suggested that there was no significant difference between the postmenopausal Asian and premenopausal Asian groups. Season specific age-matched-pairs analyses showed that in winter (P = 0.04) and spring (P = 0.007), premenopausal Asian women had a 16 to 20 nmol BCE/mmol Cr higher uNTX than premenopausal Caucasian women. The (amplitude/mesor) ratio (i.e. seasonal change) for 25(OH)D was predictive of uNTX, with estimate (SD) = 0.213 (0.015) and 95% CI (0.182, 0.245; P < 0.001) in a non-linear mixed model (n = 154). This showed that individuals with a higher seasonal change in 25(OH)D, adjusted for overall 25(OH)D concentration, showed increased levels of uNTX. Although the effect size was smaller than for the amplitude/mesor ratio, the mesor for 25(OH)D concentration was also predictive of uNTX, with estimate (SD) = − 0.035 (0.004), and 95% CI (− 0.043, − 0.028; P < 0.001). This study demonstrates higher levels of uNTX in premenopausal South Asian women than would be expected for their age, being greater than same-age Caucasian women, and similar to postmenopausal Asian women. This highlights potentially higher than expected bone resorption levels in premenopausal South Asian women which, if not offset by concurrent increased bone formation, may have future clinical and public health implications which warrant further investigation. Individuals with a larger seasonal change in 25(OH)D concentration showed an increased bone resorption, an association which was larger than that of the 25(OH)D yearly average, suggesting it may be as important clinically to ensure a stable and steady 25(OH)D concentration, as well as one that is high enough to be optimal for bone health

The effect of alfalfa (Medicago sativa) silage chop length and inclusion rate within a total mixed ration on the ability of lactating dairy cows to cope with a feed withholding and refeeding challenge

Cows fed diets containing a lower concentration of alfalfa silage (replacing corn silage) experienced greater reductions in rumen pH following a six hour feed witholding/refeeding challenge than those fed higher alfalfa concentration diets and also suffered greater short-term milk loss on the day of the challenge. Lower rumen pH in animals fed a long chop length compared to a shorter chop length raised questions over the effect of long forage particles in the diet during and following short-term feed deprivation. This research highlights the importance of maintaining feeding routines and ensuring adequate feed access throughout the day in dairy systems

The relationship between enzyme conformational change, proton transfer, and phosphoryl transfer in β-phosphoglucomutase

Molecular details for the timing and role of proton transfer in phosphoryl transfer reactions are poorly understood. Here, we have combined QM models, experimental NMR measurements, and X-ray structures to establish that the transition of an archetypal phosphoryl transfer enzyme, βPGM, from a very closed near-attack conformation to a fully closed transition state analogue (TSA) conformation triggers both partial proton transfer from the general acid–base residue to the leaving group oxygen and partial dissociation of the transferring phosphoryl group from the leaving group oxygen. Proton transfer continues but is not completed throughout the reaction path of the phosphoryl transfer with the enzyme in the TSA conformation. Moreover, using interacting quantum atoms (IQA) and relative energy gradient (REG) analysis approaches, we observed that the change in the position of the proton and the corresponding increased electrostatic repulsion between the proton and the phosphorus atom provide a stimulus for phosphoryl transfer in tandem with a reduction in the negative charge density on the leaving group oxygen atom. The agreement between solution-phase 19F NMR measurements and equivalent QM models of βPGMWT and βPGMD10N TSA complexes confirms the protonation state of G6P in the two variants, validating the employed QM models. Furthermore, QM model predictions of an AlF4 distortion in response to the proton position are confirmed using high resolution X-ray crystal structures, not only providing additional validation to the QM models but also further establishing metal fluorides as highly sensitive experimental predictors of active-site charge density distributions

Exploring Appropriation of Global Cultural Rituals

Adolescents, as a consequence of identification with popular culture, have been described as having homogenous consumption patterns. More recently, however, it has been recognised that ‘glocalisation’ (global practices reworked to fit local contexts) affords an opportunity for differentiation. This paper considers a recent UK phenomenon, namely that of the US high school prom, and seeks to explore the ways in which this ritual has been adopted or adapted as part of youth culture. The method employed here was mixed methods and included in-depth interviews with those who attended a prom in the last three years as well as a questionnaire distributed amongst high school pupils who were anticipating a high school prom. The findings illustrate that the high school prom in the UK is becoming increasingly integrated into the fabric of youth culture although, depending on the agentic abilities employed by the emerging adults in the sample, there is differing appropriation of this ritual event particularly in relation to attitudes towards and motivations for attending the prom. A typology of prom attendees is posited. This paper contributes to our understanding of this practice in a local context

The CXCL12/CXCR4 signaling axis retains neutrophils at inflammatory sites in zebrafish

The inappropriate retention of neutrophils at inflammatory sites is a major driver of the excessive tissue damage characteristic of respiratory inflammatory diseases including COPD, ARDS, and cystic fibrosis. The molecular programmes which orchestrate neutrophil recruitment to inflammatory sites through chemotactic guidance have been well-studied. However, how neutrophil sensitivity to these cues is modulated during inflammation resolution is not understood. The identification of neutrophil reverse migration as a mechanism of inflammation resolution and the ability to modulate this therapeutically has identified a new target to treat inflammatory disease. Here we investigate the role of the CXCL12/CXCR4 signaling axis in modulating neutrophil retention at inflammatory sites. We used an in vivo tissue injury model to study neutrophilic inflammation using transgenic zebrafish larvae. Expression of cxcl12a and cxcr4b during the tissue damage response was assessed using in situ hybridization and analysis of RNA sequencing data. CRISPR/Cas9 was used to knockdown cxcl12a and cxcr4b in zebrafish larvae. The CXCR4 antagonist AMD3100 was used to block the Cxcl12/Cxcr4 signaling axis pharmacologically. We identified that cxcr4b and cxcl12a are expressed at the wound site in zebrafish larvae during the inflammatory response. Following tail-fin transection, removal of neutrophils from inflammatory sites is significantly increased in cxcr4b and cxcl12a CRISPR knockdown larvae. Pharmacological inhibition of the Cxcl12/Cxcr4 signaling axis accelerated resolution of the neutrophil component of inflammation, an effect caused by an increase in neutrophil reverse migration. The findings of this study suggest that CXCR4/CXCL12 signaling may play an important role in neutrophil retention at inflammatory sites, identifying a potential new target for the therapeutic removal of neutrophils from the lung in chronic inflammatory disease

The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources

The production and analysis of distributed sources of 24Na and 222Rn in the Sudbury Neutrino Observatory (SNO) are described. These unique sources provided accurate calibrations of the response to neutrons, produced through photodisintegration of the deuterons in the heavy water target, and to low energy betas and gammas. The application of these sources in determining the neutron detection efficiency and response of the 3He proportional counter array, and the characteristics of background Cherenkov light from trace amounts of natural radioactivity is described.Comment: 24 pages, 13 figure

A Zebrafish Compound Screen Reveals Modulation of Neutrophil Reverse Migration as an Anti-Inflammatory Mechanism

Diseases of failed inflammation resolution are common and largely incurable. Therapeutic induction of inflammation resolution is an attractive strategy to bring about healing without increasing susceptibility to infection. However, therapeutic targeting of inflammation resolution has been hampered by a lack of understanding of the underlying molecular controls. To address this drug development challenge, we developed an in vivo screen for proresolution therapeutics in a transgenic zebrafish model. Inflammation induced by sterile tissue injury was assessed for accelerated resolution in the presence of a library of known compounds. Of the molecules with proresolution activity, tanshinone IIA, derived from a Chinese medicinal herb, potently induced inflammation resolution in vivo both by induction of neutrophil apoptosis and by promoting reverse migration of neutrophils. Tanshinone IIA blocked proinflammatory signals in vivo, and its effects are conserved in human neutrophils, supporting a potential role in treating human inflammation and providing compelling evidence of the translational potential of this screening strategy

Ab initio study of elastic and electronic properties of cubic thorium pnictides ThPn and Th3Pn4 (Pn = P, As, and Sb)

Full-potential linearized augmented plane-wave method with the generalized gradient approximation for the exchange-correlation potential was applied for comparative study of elastic and electronic properties of six cubic thorium pnictides ThPn and Th3Pn4, where Pn = P, As, and Sb. Optimized lattice parameters, theoretical density, independent elastic constants (Cij), bulk moduli (B), shear moduli (G), Young's moduli (Y), and Poisson's ratio ({\nu}) were obtained for the first time and analyzed in comparison with available theoretical and experimental data. The electronic band structures, total and partial densities of states for all ThPn and Th3Pn4 phases were examined systematically. Moreover, the inter-atomic bonding pictures in thorium pnictides, as well as the relative stability of ThPn versus Th3Pn4 phases were discussed.Comment: 20 pages, 6 figure

Statistical Theory of Spin Relaxation and Diffusion in Solids

A comprehensive theoretical description is given for the spin relaxation and diffusion in solids. The formulation is made in a general statistical-mechanical way. The method of the nonequilibrium statistical operator (NSO) developed by D. N. Zubarev is employed to analyze a relaxation dynamics of a spin subsystem. Perturbation of this subsystem in solids may produce a nonequilibrium state which is then relaxed to an equilibrium state due to the interaction between the particles or with a thermal bath (lattice). The generalized kinetic equations were derived previously for a system weakly coupled to a thermal bath to elucidate the nature of transport and relaxation processes. In this paper, these results are used to describe the relaxation and diffusion of nuclear spins in solids. The aim is to formulate a successive and coherent microscopic description of the nuclear magnetic relaxation and diffusion in solids. The nuclear spin-lattice relaxation is considered and the Gorter relation is derived. As an example, a theory of spin diffusion of the nuclear magnetic moment in dilute alloys (like Cu-Mn) is developed. It is shown that due to the dipolar interaction between host nuclear spins and impurity spins, a nonuniform distribution in the host nuclear spin system will occur and consequently the macroscopic relaxation time will be strongly determined by the spin diffusion. The explicit expressions for the relaxation time in certain physically relevant cases are given.Comment: 41 pages, 119 Refs. Corrected typos, added reference