An α2(Zα)5m\alpha^{2}(Z \alpha)^{5}m Contribution to the Hydrogen Lamb Shift from Virtual Light by Light Scattering

The radiative correction to the Lamb shift of order $\alpha^{2}(Z\alpha)^5m$ induced by the light by light scattering insertion in external photons is obtained. The new contribution turns out to be equal to $-0.122(2)\alpha^2(Z\alpha)^5/(\pi n^3)(m_r/m)^3m$. Combining this contribution with our previous results we obtain the complete correction of order $\alpha^{2}(Z\alpha)^5m$ induced by all diagrams with closed electron loops. This correction is $37.3(1)$ kHz and $4.67(1)$ kHz for the $1S$- and $2S$-states in hydrogen, respectively.Comment: pages, Penn State Preprint PSU/TH/142, February 199

Twenty-four-hour, weekly and annual patterns in serious falls of non-institutionalized independent Spanish seniors.

OBJECTIVE: The study aimed to explore clock hour, day-of-week, and month-of-year patterns of serious falls experienced by non-institutionalized Spanish seniors (age ≥65 years) in relation to associated conventional intrinsic and extrinsic factors. PATIENTS AND METHODS: Intake emergency department records from January 1 to December 31, 2013 of a tertiary hospital of southern Spain were abstracted for particulars of falls, including the time of occurrence, experienced specifically by non-institutionalized seniors. Chi-squares and Single and Multiple-Component Cosinor (time series) Analyses were applied to determine the statistical significance of observed 24-hour, 7-day, and annual variation. RESULTS: Falls were ~2.5-fold more numerous in older women than older men and ~7-fold more frequent between 12:00 and 14:00 hours than ~02:00 hours, respectively, the time spans corresponding to the absolute peak and trough of the 24-hour pattern in falls. The midday/early afternoon peak primarily represented incidents of women ≥75 years of age that occurred inside the home while walking, standing, or moving on stairs. A late evening less prominent excess of mostly inside-the-home incidents of women ≥75 years of age, largely due to fragility, slipping, stumbling, or tripping, was additionally detected. Cosinor Analysis substantiates statistical significance of the 24-hour patterning of falls of men and women (both p<0.001). Day-of-week differences, with prominent Thursday peak and Sunday minimum, were additionally detected, but only for falls of women occurring outside the home (Cosinor Analysis: p=0.007). Day-of-week discrepancy in female/male sex ratio (SR) of fallers was demonstrated, arising from day-of-week disparity in the SR of inside-the-home incidents, with ~4.5-fold more elderly women than elderly men falling Thursday than any other day of the week (p=0.005). Non-statistically significant month-of-year difference in falls, lowest in autumn and highest (~60% more) in winter, was observed and explained by prominent seasonal difference in incidents by elderly women. CONCLUSIONS: Serious falls of non-institutionalized independent seniors are characterized according to intrinsic and extrinsic factors by prominent 24-hour and 7-day patterning. These findings complement the understanding of the epidemiology of falls of the elderly and further inform fall prevention programs

A double-slit `which-way' experiment on the complementarity--uncertainty debate

A which-way measurement in Young's double-slit will destroy the interference pattern. Bohr claimed this complementarity between wave- and particle behaviour is enforced by Heisenberg's uncertainty principle: distinguishing two positions a distance s apart transfers a random momentum q \sim \hbar/s to the particle. This claim has been subject to debate: Scully et al. asserted that in some situations interference can be destroyed with no momentum transfer, while Storey et al. asserted that Bohr's stance is always valid. We address this issue using the experimental technique of weak measurement. We measure a distribution for q that spreads well beyond [-\hbar/s, \hbar/s], but nevertheless has a variance consistent with zero. This weakvalued momentum-transfer distribution P_{wv}(q) thus reflects both sides of the debate.Comment: 13 pages, 4 figure

Testing the Equivalence Principle by Lamb shift Energies

The Einstein Equivalence Principle has as one of its implications that the non-gravitational laws of physics are those of special relativity in any local freely-falling frame. We consider possible tests of this hypothesis for systems whose energies are due to radiative corrections, i.e. which arise purely as a consequence of quantum field theoretic loop effects. Specifically, we evaluate the Lamb shift transition (as given by the energy splitting between the $2S_{1/2}$ and $2P_{1/2}$ atomic states) within the context of violations of local position invariance and local Lorentz invariance, as described by the $T H \epsilon\mu$ formalism. We compute the associated red shift and time dilation parameters, and discuss how (high-precision) measurements of these quantities could provide new information on the validity of the equivalence principle.Comment: 40 pages, latex, epsf, 1 figure, final version which appears in Physical Review

Building a Global Evidence Base to Guide Policy and Implementation for Group Antenatal Care in Low‐ and Middle‐Income Countries: Key Principles and Research Framework Recommendations from the Global Group Antenatal Care Collaborative

Evidence from high‐income countries suggests that group antenatal care, an alternative service delivery model, may be an effective strategy for improving both the provision and experience of care. Until recently, published research about group antenatal care did not represent findings from low‐ and middle‐income countries, which have health priorities, system challenges, and opportunities that are different than those in high‐income countries. Because high‐quality evidence is limited, the World Health Organization recommends group antenatal care be implemented only in the context of rigorous research. In 2016 the Global Group Antenatal Care Collaborative was formed as a platform for group antenatal care researchers working in low‐ and middle‐income countries to share experiences and shape future research to accelerate development of a robust global evidence base reflecting implementation and outcomes specific to low‐ and middle‐income countries. This article presents a brief history of the Collaborative’s work to date, proposes a common definition and key principles for group antenatal care, and recommends an evaluation and reporting framework for group antenatal care research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163383/2/jmwh13143.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163383/1/jmwh13143_am.pd

Measuring Measurement: Theory and Practice

Recent efforts have applied quantum tomography techniques to the calibration and characterization of complex quantum detectors using minimal assumptions. In this work we provide detail and insight concerning the formalism, the experimental and theoretical challenges and the scope of these tomographical tools. Our focus is on the detection of photons with avalanche photodiodes and photon number resolving detectors and our approach is to fully characterize the quantum operators describing these detectors with a minimal set of well specified assumptions. The formalism is completely general and can be applied to a wide range of detectorsComment: 22 pages, 27 figure

High (but Not Low) Urinary Iodine Excretion Is Predicted by Iodine Excretion Levels from Five Years Ago

Background: It has not been investigated whether there are associations between urinary iodine (UI) excretion measurements some years apart, nor whether such an association remains after adjustment for nutritional habits. The aim of the present study was to investigate the relation between iodine-creatinine ratio (ICR) at two measuring points 5 years apart. Methods: Data from 2,659 individuals from the Study of Health in Pomerania were analyzed. Analysis of covariance and Poisson regressions were used to associate baseline with follow-up ICR. Results: Baseline ICR was associated with follow-up ICR. Particularly, baseline ICR >300 mu g/g was related to an ICR >300 mu g/g at follow-up (relative risk, RR: 2.20; p < 0.001). The association was stronger in males (RR: 2.64; p < 0.001) than in females (RR: 1.64; p = 0.007). In contrast, baseline ICR <100 mu g/g was only associated with an ICR <100 mu g/g at follow-up in males when considering unadjusted ICR. Conclusions: We detected only a weak correlation with respect to low ICR. Studies assessing iodine status in a population should take into account that an individual with a low UI excretion in one measurement is not necessarily permanently iodine deficient. On the other hand, current high ICR could have been predicted by high ICR 5 years ago. Copyright (C) 2011 S. Karger AG, Base

Rank-based model selection for multiple ions quantum tomography

The statistical analysis of measurement data has become a key component of many quantum engineering experiments. As standard full state tomography becomes unfeasible for large dimensional quantum systems, one needs to exploit prior information and the "sparsity" properties of the experimental state in order to reduce the dimensionality of the estimation problem. In this paper we propose model selection as a general principle for finding the simplest, or most parsimonious explanation of the data, by fitting different models and choosing the estimator with the best trade-off between likelihood fit and model complexity. We apply two well established model selection methods -- the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) -- to models consising of states of fixed rank and datasets such as are currently produced in multiple ions experiments. We test the performance of AIC and BIC on randomly chosen low rank states of 4 ions, and study the dependence of the selected rank with the number of measurement repetitions for one ion states. We then apply the methods to real data from a 4 ions experiment aimed at creating a Smolin state of rank 4. The two methods indicate that the optimal model for describing the data lies between ranks 6 and 9, and the Pearson $\chi^{2}$ test is applied to validate this conclusion. Additionally we find that the mean square error of the maximum likelihood estimator for pure states is close to that of the optimal over all possible measurements.Comment: 24 pages, 6 figures, 3 table

Manipulating the quantum information of the radial modes of trapped ions: Linear phononics, entanglement generation, quantum state transmission and non-locality tests

We present a detailed study on the possibility of manipulating quantum information encoded in the "radial" modes of arrays of trapped ions (i.e., in the ions' oscillations orthogonal to the trap's main axis). In such systems, because of the tightness of transverse confinement, the radial modes pertaining to different ions can be addressed individually. In the first part of the paper we show that, if local control of the radial trapping frequencies is available, any linear optical and squeezing operation on the locally defined modes - on single as well as on many modes - can be reproduced by manipulating the frequencies. Then, we proceed to describe schemes apt to generate unprecedented degrees of bipartite and multipartite continuous variable entanglement under realistic noisy working conditions, and even restricting only to a global control of the trapping frequencies. Furthermore, we consider the transmission of the quantum information encoded in the radial modes along the array of ions, and show it to be possible to a remarkable degree of accuracy, for both finite-dimensional and continuous variable quantum states. Finally, as an application, we show that the states which can be generated in this setting allow for the violation of multipartite non-locality tests, by feasible displaced parity measurements. Such a demonstration would be a first test of quantum non-locality for "massive" degrees of freedom (i.e., for degrees of freedom describing the motion of massive particles).Comment: 21 pages; this paper, presenting a far more extensive and detailed analysis, completely supersedes arXiv:0708.085

Mineralogy of the Lunar Crust in Spatial Context: First Results from the Moon Mineralogy Mapper (M3)

India's Chandrayaan-1 successfully launched October 22, 2008 and went into lunar orbit a few weeks later. Commissioning of instruments began in late November and was near complete by the end of the year. Initial data for NASA's Moon Mineralogy Mapper (M3) were acquired across the Orientale Basin and the science results are discussed here. M 3 image-cube data provide mineralogy of the surface in geologic context. A major new result is that the existence and distribution of massive amounts of anorthosite as a continuous stratigraphic crustal layer is now irrefutable