2,348 research outputs found
Can a falling tree make a noise in two forests at the same time?
It is a commonplace to claim that quantum mechanics supports the old idea
that a tree falling in a forest makes no sound unless there is a listener
present. In fact, this conclusion is far from obvious. Furthermore, if a
tunnelling particle is observed in the barrier region, it collapses to a state
in which it is no longer tunnelling. Does this imply that while tunnelling, the
particle can not have any physical effects? I argue that this is not the case,
and moreover, speculate that it may be possible for a particle to have effects
on two spacelike separate apparatuses simultaneously. I discuss the measurable
consequences of such a feat, and speculate about possible statistical tests
which could distinguish this view of quantum mechanics from a ``corpuscular''
one. Brief remarks are made about an experiment underway at Toronto to
investigate these issues.Comment: 9 pp, Latex, 3 figs, to appear in Proc. Obsc. Unr. Conf.; Fig 2
postscript repaired on 26.10.9
Boundaries of Semantic Distraction: Dominance and Lexicality Act at Retrieval
Three experiments investigated memory for semantic information with the goal of determining boundary conditions for the manifestation of semantic auditory distraction. Irrelevant speech disrupted the free recall of semantic category-exemplars to an equal degree regardless of whether the speech coincided with presentation or test phases of the task (Experiment 1) and occurred regardless of whether it comprised random words or coherent sentences (Experiment 2). The effects of background speech were greater when the irrelevant speech was semantically related to the to-be-remembered material, but only when the irrelevant words were high in output dominance (Experiment 3). The implications of these findings in relation to the processing of task material and the processing of background speech is discussed
Effect of antiandrogen flutamide on measures of hepatic regeneration in rats
Male rat liver undergoes a process of demasculinization during hepatic regeneration following partial hepatectomy. The possibility that antiandrogens might potentiate this demasculinization process and in so doing augment the hepatic regenerative response was investigated. Adult male Wistar rats were treated with the antiandrogen flutamide (2 mg/rat/day or 5 mg/rat/day subcutaneously) or vehicle for three days prior to and daily after a 70% partial hepatectomy. At various times after hepatectomy, the liver remnants were removed and weighed. Rates of DNA and polyamine synthesis were assessed by measuring thymidine kinase and ornithine decarboxylase activities, respectively. Hepatic estrogen receptor status and the activity of alcohol dehydrogenase, an androgen-sensitive protein, were measured. Prior to surgery, the administration of 5 mg/day flutamide reduced the hepatic cytosolic androgen receptor activity by 98% and hepatic cytosolic estrogen receptor content by 92% compared to that present in vehicle-treated controls. After hepatectomy, however, all differences in sex hormone receptor activity between the treatment groups were abolished. The rate of liver growth after partial hepatectomy in the three groups was identical. Moreover, hepatectomy-induced increases in ornithine decarboxylase activity and thymidine kinase activity were comparable. These data demonstrate that, although flutamide administration initially alters the sex hormone receptor status of the liver, these affects have no effect on the hepatic regenerative response following a partial hepatectomy. © 1989 Plenum Publishing Corporation
Transferability of Deep Learning Algorithms for Malignancy Detection in Confocal Laser Endomicroscopy Images from Different Anatomical Locations of the Upper Gastrointestinal Tract
Squamous Cell Carcinoma (SCC) is the most common cancer type of the
epithelium and is often detected at a late stage. Besides invasive diagnosis of
SCC by means of biopsy and histo-pathologic assessment, Confocal Laser
Endomicroscopy (CLE) has emerged as noninvasive method that was successfully
used to diagnose SCC in vivo. For interpretation of CLE images, however,
extensive training is required, which limits its applicability and use in
clinical practice of the method. To aid diagnosis of SCC in a broader scope,
automatic detection methods have been proposed. This work compares two methods
with regard to their applicability in a transfer learning sense, i.e. training
on one tissue type (from one clinical team) and applying the learnt
classification system to another entity (different anatomy, different clinical
team). Besides a previously proposed, patch-based method based on convolutional
neural networks, a novel classification method on image level (based on a
pre-trained Inception V.3 network with dedicated preprocessing and
interpretation of class activation maps) is proposed and evaluated. The newly
presented approach improves recognition performance, yielding accuracies of
91.63% on the first data set (oral cavity) and 92.63% on a joint data set. The
generalization from oral cavity to the second data set (vocal folds) lead to
similar area-under-the-ROC curve values than a direct training on the vocal
folds data set, indicating good generalization.Comment: Erratum for version 1, correcting the number of CLE image sequences
used in one data se
Preparation and Measurement of Three-Qubit Entanglement in a Superconducting Circuit
Traditionally, quantum entanglement has played a central role in foundational
discussions of quantum mechanics. The measurement of correlations between
entangled particles can exhibit results at odds with classical behavior. These
discrepancies increase exponentially with the number of entangled particles.
When entanglement is extended from just two quantum bits (qubits) to three, the
incompatibilities between classical and quantum correlation properties can
change from a violation of inequalities involving statistical averages to sign
differences in deterministic observations. With the ample confirmation of
quantum mechanical predictions by experiments, entanglement has evolved from a
philosophical conundrum to a key resource for quantum-based technologies, like
quantum cryptography and computation. In particular, maximal entanglement of
more than two qubits is crucial to the implementation of quantum error
correction protocols. While entanglement of up to 3, 5, and 8 qubits has been
demonstrated among spins, photons, and ions, respectively, entanglement in
engineered solid-state systems has been limited to two qubits. Here, we
demonstrate three-qubit entanglement in a superconducting circuit, creating
Greenberger-Horne-Zeilinger (GHZ) states with fidelity of 88%, measured with
quantum state tomography. Several entanglement witnesses show violation of
bi-separable bounds by 830\pm80%. Our entangling sequence realizes the first
step of basic quantum error correction, namely the encoding of a logical qubit
into a manifold of GHZ-like states using a repetition code. The integration of
encoding, decoding and error-correcting steps in a feedback loop will be the
next milestone for quantum computing with integrated circuits.Comment: 7 pages, 4 figures, and Supplementary Information (4 figures)
A contingent valuation study to estimate the parental willingness-to-pay for childhood diarrhoea and gender bias among rural households in India
We used contingent valuation technique to estimate the parental willingness to pay for an episode of diarrhoea among 324 children of both sexes aged between five and seven years in two rural villages of Chennai in India. The aim was to examine if there was any gender bias in the parental willingness to treat children for a diarrhoeal episode, and if so to what extent. The willingness to pay was specified as a hedonic function of the duration and severity of an episode, and of parents' socioeconomic characteristics. The findings suggest that parents were willing to pay more to protect their male child compared to the female child suffering from a diarrhoeal episode. The median willingness to pay to avoid an episode for male and female children were calculated at Rs. 33.7 (approx. US 0.54) respectively – a difference of around 34%. After adjusting for the greater duration and severity of the illness, it was found that the difference between the two medians increased to 51%
Publishing and sharing multi-dimensional image data with OMERO
Imaging data are used in the life and biomedical sciences to measure the molecular and structural composition and dynamics of cells, tissues, and organisms. Datasets range in size from megabytes to terabytes and usually contain a combination of binary pixel data and metadata that describe the acquisition process and any derived results. The OMERO image data management platform allows users to securely share image datasets according to specific permissions levels: data can be held privately, shared with a set of colleagues, or made available via a public URL. Users control access by assigning data to specific Groups with defined membership and access rights. OMERO’s Permission system supports simple data sharing in a lab, collaborative data analysis, and even teaching environments. OMERO software is open source and released by the OME Consortium at www.openmicroscopy.org
Should Research Ethics Encourage the Production of Cost-Effective Interventions?
This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs
Topologically Protected Quantum State Transfer in a Chiral Spin Liquid
Topology plays a central role in ensuring the robustness of a wide variety of
physical phenomena. Notable examples range from the robust current carrying
edge states associated with the quantum Hall and the quantum spin Hall effects
to proposals involving topologically protected quantum memory and quantum logic
operations. Here, we propose and analyze a topologically protected channel for
the transfer of quantum states between remote quantum nodes. In our approach,
state transfer is mediated by the edge mode of a chiral spin liquid. We
demonstrate that the proposed method is intrinsically robust to realistic
imperfections associated with disorder and decoherence. Possible experimental
implementations and applications to the detection and characterization of spin
liquid phases are discussed.Comment: 14 pages, 7 figure
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