Self calibration iso-pathlength point in cylindrical tissue geometry: Solution of steady-state photon diffusion based on the extrapolated zero-boundary

Near-infrared optical techniques permit tissue diagnosis by surface measurement. However, the geometrical shape of this interface profiles the intensity of the surface measurement, which is found to have an iso-pathlength (IPL) point allowing for absorption identification independent of tissue scattering. The IPL point was projected in Monte Carlo (MC) simulation, validated experimentally in cylindrical tissues, but remains under-appreciated through analytical approaches. In this work, we present an analytical solution of an IPL point for steady-state diffusion based on the extrapolated zero-boundary condition. The same IPL points were found when comparing this solution to 3-D MC simulations for a tissue radius range of 5-8mm.Electrical and Computer Engineerin

Application of a Static Fluorescence-based Cytometer (the CellScan) in Basic Cytometric Studies, Clinical Pharmacology, Oncology and Clinical Immunology

The CellScan apparatus is a laser scanning cytometer enabling repetitive fluorescence intensity (FI) and polarization (FP) measurements in living cells, as a means of monitoring lymphocyte activation. The CellScan may serve as a tool for diagnosis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) as well as other autoimmune diseases by monitoring FP changes in peripheral blood lymphocytes (PBLs) following exposure to autoantigenic stimuli. Changes in FI and FP in atherosclerotic patients' PBLs following exposure to various stimuli have established the role of the immune system in atherosclerotic disease. The CellScan has been evaluated as a diagnostic tool for drug-allergy, based on FP reduction in PBLs following incubation with allergenic drugs. FI and FP changes in cancer cells have been found to be well correlated with the cytotoxic effect of anti-neoplastic drugs. In conclusion, the CellScan has a variety of applications in cell biology, immunology, cancer research and clinical pharmacology

Ramsey interferometry with an atom laser

We present results on a free-space atom interferometer operating on the first order magnetically insensitive |F=1,mF=0> -> |F=2,mF=0> transition of Bose-condensed 87Rb atoms. A pulsed atom laser is output-coupled from a Bose-Einstein condensate and propagates through a sequence of two internal state beam splitters, realized via coherent Raman transitions between the two interfering states. We observe Ramsey fringes with a visibility close to 100% and determine the current and the potentially achievable interferometric phase sensitivity. This system is well suited to testing recent proposals for generating and detecting squeezed atomic states.Comment: published version, 8 pages, 3 figure

Nonlinear atom interferometer surpasses classical precision limit

Interference is fundamental to wave dynamics and quantum mechanics. The quantum wave properties of particles are exploited in metrology using atom interferometers, allowing for high-precision inertia measurements [1, 2]. Furthermore, the state-of-the-art time standard is based on an interferometric technique known as Ramsey spectroscopy. However, the precision of an interferometer is limited by classical statistics owing to the finite number of atoms used to deduce the quantity of interest [3]. Here we show experimentally that the classical precision limit can be surpassed using nonlinear atom interferometry with a Bose-Einstein condensate. Controlled interactions between the atoms lead to non-classical entangled states within the interferometer; this represents an alternative approach to the use of non-classical input states [4-8]. Extending quantum interferometry [9] to the regime of large atom number, we find that phase sensitivity is enhanced by 15 per cent relative to that in an ideal classical measurement. Our nonlinear atomic beam splitter follows the "one-axis-twisting" scheme [10] and implements interaction control using a narrow Feshbach resonance. We perform noise tomography of the quantum state within the interferometer and detect coherent spin squeezing with a squeezing factor of -8.2dB [11-15]. The results provide information on the many-particle quantum state, and imply the entanglement of 170 atoms [16]

Outsourcing with debt financing

This paper investigates the effect of capital structure on a firm’s choice between vertical integration and outsourcing. We model the production decision in a Principal-Agent framework and show that suppliers use debt as a strategic instrument to collect the surplus from outsourcing as their wealth constraint or limited liability ensures them more attractive compensation schemes. Investigating the buyer’s capital structure, we find that outsourcing with risky debt is more likely to occur for high values of the outsourcing surplus.info:eu-repo/semantics/publishedVersio

A General-Equilibrium Asset-Pricing Approach to the Measurement of Nominal and Real Bank Output

This paper addresses the proper measurement of financial service output that is not priced explicitly. It shows how to impute nominal service output from financial intermediaries' interest income and how to construct price indices for those financial services. We present an optimizing model with financial intermediaries that provide financial services to resolve asymmetric information between borrowers and lenders. We embed these intermediaries in a dynamic, stochastic, general-equilibrium model where assets are priced competitively according to their systematic risk, as in the standard consumption capital-asset-pricing model. In this environment, we show that it is critical to take risk into account in order to measure financial output accurately. We also show that even using a risk-adjusted reference rate does not solve all the problems associated with measuring nominal financial service output. Our model allows us to address important outstanding questions in output and productivity measurement for financial firms, such as: (1) What are the correct reference rates to use in calculating bank output? In particular, should they take account of risk? (2) If reference rates need to be risk-adjusted, does it mean that they must be ex ante rates of return? (3) What is the right price deflator for the output of financial firms? Is it just the general price index? (4) When-if ever-should we count capital gains of financial firms as part of financial service output

High blood pressure in school children: prevalence and risk factors

BACKGROUND: The purpose of this study was to determine the prevalence of high blood pressure (HBP) and associated risk factors in school children 8 to 13 years of age. METHODS: Elementary school children (n = 1,066) were examined. Associations between HBP, body mass index (BMI), gender, ethnicity, and acanthosis nigricans (AN) were investigated using a school based cross-sectional study. Blood pressure was measured and the 95(th )percentile was used to determine HBP. Comparisons between children with and without HBP were utilized. The crude and multiple logistic regression adjusted odds ratios were used as measures of association. RESULTS: Females, Hispanics, overweight children, and children with AN had an increased likelihood of HBP. Overweight children (BMI ≥ 85(th )percentile) and those with AN were at least twice as likely to present with HBP after controlling for confounding factors. CONCLUSION: Twenty one percent of school children had HBP, especially the prevalence was higher among the overweight and Hispanic group. The association identified here can be used as independent markers for increased likelihood of HBP in children

A Simple Method to Account for Measurement Errors in Revealed Preference Tests

Revealed preference tests are widely used in empirical applications of consumer rationality. These are static tests, and consequently, lack ability to handle measurement errors in the data. This paper extends and generalizes existing procedures that account for measurement errors in revealed preference tests. In particular, it introduces a very efficient method to implement these procedures, which make them operational for large data sets. The paper illustrates the new method for both classical and Berkson measurement errors models