14,971 research outputs found

    The importance of increasing the forensic relevance of oral health records for improved human identification outcomes

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    First published online 4 April 2017Dental comparison can confirm human identity to a high degree of certainty. Research examining Australian-made records demonstrated suboptimal recording of dental traits important for forensic dental identification and compliance with Dental Board of Australia (DBA) record keeping guidelines. This is a significant issue for human identification by dental comparison; lack of adequate antemortem information can hinder or obstruct outcomes. Reported identification opinions from the Forensic Odontology Unit of South Australia (FOUSA) during 2011-2015 were assessed to determine whether the quantitative and qualitative value of antemortem records affected the ultimate identification outcome. Identity was established in 79% (n=197) of the 249 cases presented to the FOU-SA; odontology was unable to categorically confirm an individual's identity for the remaining 21%. Dental records of almost all cases demonstrated a lack of antemortem data for comparison. Inadequate antemortem information within dental records may preclude identity determination; at minimum, an outcome is hindered by a greater number of issues requiring reconciliation. Given previous results regarding adherence to DBA guidelines, practitioners should reasonably be expected to make small recording changes to improve the continuity of clinical patient care. This antemortem recording improvement will potentially improve the rate at which a forensic identification is reconciled.Lauren Stow and Denice Higgin

    Adaptive Measurements in the Optical Quantum Information Laboratory

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    Adaptive techniques make practical many quantum measurements that would otherwise be beyond current laboratory capabilities. For example: they allow discrimination of nonorthogonal states with a probability of error equal to the Helstrom bound; they allow measurement of the phase of a quantum oscillator with accuracy approaching (or in some cases attaining) the Heisenberg limit; and they allow estimation of phase in interferometry with a variance scaling at the Heisenberg limit, using only single qubit measurement and control. Each of these examples has close links with quantum information, in particular experimental optical quantum information: the first is a basic quantum communication protocol; the second has potential application in linear optical quantum computing; the third uses an adaptive protocol inspired by the quantum phase estimation algorithm. We discuss each of these examples, and their implementation in the laboratory, but concentrate upon the last, which was published most recently [Higgins {\em et al.}, Nature vol. 450, p. 393, 2007].Comment: 12 pages, invited paper to be published in IEEE Journal of Selected Topics in Quantum Electronics: Quantum Communications and Information Scienc

    Entanglement-enhanced measurement of a completely unknown phase

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    The high-precision interferometric measurement of an unknown phase is the basis for metrology in many areas of science and technology. Quantum entanglement provides an increase in sensitivity, but present techniques have only surpassed the limits of classical interferometry for the measurement of small variations about a known phase. Here we introduce a technique that combines entangled states with an adaptive algorithm to precisely estimate a completely unspecified phase, obtaining more information per photon that is possible classically. We use the technique to make the first ab initio entanglement-enhanced optical phase measurement. This approach will enable rapid, precise determination of unknown phase shifts using interferometry.Comment: 6 pages, 4 figure

    Role of oxygen in the electron-doped superconducting cuprates

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    We report on resistivity and Hall measurements in thin films of the electron-doped superconducting cuprate Pr2−x_{2-x}Cex_{x}CuO4±δ_{4\pm\delta}. Comparisons between x = 0.17 samples subjected to either ion-irradiation or oxygenation demonstrate that changing the oxygen content has two separable effects: 1) a doping effect similar to that of cerium, and 2) a disorder effect. These results are consistent with prior speculations that apical oxygen removal is necessary to achieve superconductivity in this compound.Comment: 5 pages, 5 figure

    Feature weighting techniques for CBR in software effort estimation studies: A review and empirical evaluation

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    Context : Software effort estimation is one of the most important activities in the software development process. Unfortunately, estimates are often substantially wrong. Numerous estimation methods have been proposed including Case-based Reasoning (CBR). In order to improve CBR estimation accuracy, many researchers have proposed feature weighting techniques (FWT). Objective: Our purpose is to systematically review the empirical evidence to determine whether FWT leads to improved predictions. In addition we evaluate these techniques from the perspectives of (i) approach (ii) strengths and weaknesses (iii) performance and (iv) experimental evaluation approach including the data sets used. Method: We conducted a systematic literature review of published, refereed primary studies on FWT (2000-2014). Results: We identified 19 relevant primary studies. These reported a range of different techniques. 17 out of 19 make benchmark comparisons with standard CBR and 16 out of 17 studies report improved accuracy. Using a one-sample sign test this positive impact is significant (p = 0:0003). Conclusion: The actionable conclusion from this study is that our review of all relevant empirical evidence supports the use of FWTs and we recommend that researchers and practitioners give serious consideration to their adoption

    Scanner Invariant Representations for Diffusion MRI Harmonization

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    Purpose: In the present work we describe the correction of diffusion-weighted MRI for site and scanner biases using a novel method based on invariant representation. Theory and Methods: Pooled imaging data from multiple sources are subject to variation between the sources. Correcting for these biases has become very important as imaging studies increase in size and multi-site cases become more common. We propose learning an intermediate representation invariant to site/protocol variables, a technique adapted from information theory-based algorithmic fairness; by leveraging the data processing inequality, such a representation can then be used to create an image reconstruction that is uninformative of its original source, yet still faithful to underlying structures. To implement this, we use a deep learning method based on variational auto-encoders (VAE) to construct scanner invariant encodings of the imaging data. Results: To evaluate our method, we use training data from the 2018 MICCAI Computational Diffusion MRI (CDMRI) Challenge Harmonization dataset. Our proposed method shows improvements on independent test data relative to a recently published baseline method on each subtask, mapping data from three different scanning contexts to and from one separate target scanning context. Conclusion: As imaging studies continue to grow, the use of pooled multi-site imaging will similarly increase. Invariant representation presents a strong candidate for the harmonization of these data

    Some model experiments on continental shelf waves

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    This paper describes some model experiments that verify the theoretical form of continental shelf waves. Both the dispersion relationship and the positions of the orbital gyres are confirmed. The existence of a maximum frequency for each mode, with a corresponding zero group velocity, may be of significance for field observations

    A simplified picture for Pi electrons in conjugated polymers : from PPP Hamiltonian to an effective molecular crystal approach

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    An excitonic method proper to study conjugated oligomers and polymers is described and its applicability tested on the ground state and first excited states of trans-polyacetylene, taken as a model. From the Pariser-Parr-Pople Hamiltonian, we derive an effective Hamiltonian based on a local description of the polymer in term of monomers; the relevant electronic configurations are build on a small number of pertinent local excitations. The intuitive and simple microscopic physical picture given by our model supplement recent results, such as the Rice and Garstein ones. Depending of the parameters, the linear absorption appears dominated by an intense excitonic peak.Comment: 41 Pages, 6 postscript figure

    Effects of Fire in the Northern Great Plains

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    Fire has been used inconsistently to manage native and tame grasslands in the Northern Great Plains (NGP) of the north-central U.S. and south-central Canada, particularly the grasslands found in prairies, plains, agricultural land retirement programs, and moist soil sites. This has happened for three primary reasons: (1) the reduction of American Indian use of fire after 1875, (2) fire suppression and land use changes that put increasingly more acres under annual tillage since about the same time, and (3) a growing resistance to the use of fire since about 1940, largely due to media overemphasis of its harmful effects (e.g., Bambi and Smokey the Bear ). Little can be done to change the first two factors but there is ample opportunity to change human attitudes about fire. Attitudes change when the knowledge (or lack of it) changes. We believe that people have been reluctant to include fire in resource management programs in the NGP because of a lack of adequate information about the effects of fire on the soils, plants, and animals in the region. This document provides information concerning fire effects on the grassland biome of the NGP, with special emphasis on the use of fire for wildlife management. In several instances we have drawn from published literature outside the geographic region, but only to provide a more complete reference for readers and decision makers. In most instances, we only state or abstract the published findings of others without interpretation, either pro or con. Readers can fit the information into their specific circumstances. English and scientific names are from Flora of the Great Plains by the Great Plains Flora Association and from the Checklist of Vertebrates of the United States, the U.S. territories, and Canada by RC. Banks, R.W. McDiarmid, and A.L. Gardner
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