23 research outputs found

    Measurement and control of spatial qubits generated by passing photons through double-slits

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    We present an experimental study of the non-classical correlations of a pair of spatial qubits formed by passing two down-converted photons through a pair of double slits. After confirming the entanglement generated in our setup by quantum tomography using separate measurements of the slit images and the interference patterns, we show that the complete Hilbert space of the spatial qubits can be accessed by measurements performed in a single plane between the image plane and the focal plane of a lens. Specifically, it is possible to obtain both the which-path and the interference information needed for quantum tomography in a single scan of the transversal distribution of photon coincidences. Since this method can easily be extended to multi-dimensional systems, it may be a valuable tool in the application of spatial qudits to quantum information processes.Comment: 19 pages, including 10 figures and 2 table

    Weak measurement of photon polarization by back-action induced path interference

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    The essential feature of weak measurements on quantum systems is the reduction of measurement back-action to negligible levels. To observe the non-classical features of weak measurements, it is therefore more important to avoid additional back-action errors than it is to avoid errors in the actual measurement outcome. In this paper, it is shown how an optical weak measurement of diagonal (PM) polarization can be realized by path interference between the horizontal (H) and vertical (V) polarization components of the input beam. The measurement strength can then be controlled by rotating the H and V polarizations towards each other. This well-controlled operation effectively generates the back-action without additional decoherence, while the visibility of the interference between the two beams only limits the measurement resolution. As the experimental results confirm, we can obtain extremely high weak values, even at rather low visibilities. Our method therefore provides a realization of weak measurements that is extremely robust against experimental imperfections.Comment: 11 pages, 3 figure

    Mechanical Ventilation of the Newborn: The therapeutic Interventions and Influences on the Life Process of the Neonate, a Discussion on Human Development

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    Karen Ann Quinlan is an example of the awesome determining influence that legal, medical and religious institutions have on the course of life and death of a human being. Tremendous advancements in medical technology have brought about a need to raise many questions about institutional intervention, whether by government, religion or medicine into the rights and freedoms of the individual. Now that we can, through technological processing sustain a human life artificially or by other "extraordinary" means, the act of dying must be carefully examined in order to clarify: (1) the need for such sustaining actions; (2) the potentials and limits of these actions; (3) the protocol ensuring utilization of available technology; (4) the ethical considerations in the implementation of these kinds of processes; and (5) the respect and dignity with which each individual is vested. In this presentation, an attempt is made to explore from a human development prospective (see Appendix A) the course of growth and development affecting neonates (the first 28 days of life) who are less than 28 in gestational age and less than 1500 grams in weight, and who require mechanical (assisted) ventilation and oxygen therapy at birth. It has been postulated that 28 weeks gestation is the minimum time for the physiological maturity of the lungs which is the anatomical structure responsible for respiration and whose development is a primary determiner if viability

    Devisal of Automated Carbon Dioxide Insufflation System for CT Colonography

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    Effects of Upcountry Maui water additives on health.

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    Since 2001 Upcountry Maui residents have been concerned that water additives may be linked to health problems in their community. A study using phone surveys was conducted to assess this issue. Most people suffered skin rashes, while others experienced eye irritations or respiratory problems. The surveys suggested that these symptoms might have been attributable to the water additives.D35HP16002/PHS HHS/United State

    Preoperative T staging using CT colonography with multiplanar reconstruction for very low rectal cancer

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    Abstract Background Preoperative T staging of lower rectal cancer is an important criterion for selecting intersphincteric resection (ISR) or abdominoperineal resection (APR) as well as selecting neoadjuvant therapy. The aim of this study was to evaluate the accuracy of preoperative T staging using CT colonography (CTC) with multiplanar reconstruction (MPR), in which with the newest workstation the images can be analyzed with a slice thickness of 0.5 mm. Methods Between 2011 and 2013, 45 consecutive patients with very low rectal adenocarcinoma underwent CTC with MPR. The accuracy of preoperative T staging using CTC with MPR was evaluated. The accuracy of preoperative T staging using MRI in the same patient population (34 of 45 patients) was also examined. Results Overall accuracy of T staging was 89% (41/45) for CTC with MPR and 71% (24/34) for MRI. CTC with MPR was particularly sensitive for pT2 tumors (82%; 14/17), whereas MRI tended to overstage pT2 tumors and its sensitivity for pT2 was 53% (8/15). Conclusions CTC with MPR, with an arbitrary selection, could be aligned to the tumor axis and better demonstrated tumor margins consecutively including the deepest section of the tumor. The accuracy of T2 and T3 staging using CTC with MPR seemed to surpass that of MRI, suggesting a potential role of CTC with MPR in preoperative T staging for very low rectal cancer

    Colorectal Laterally Spreading Tumors by Computed Tomographic Colonography

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    To date, few reports focused primarily on detecting colorectal laterally spreading tumors (LSTs) have been published. The aim of this study was to determine the visibility of LSTs on computed tomographic colonography (CTC) compared with that on colonoscopy as a standard. We retrospectively reviewed and matched data on endoscopic and CTC reports in 157 patients (161 LSTs) who received a multidetector CT scan using contrast media immediately after total colonoscopy at the National Cancer Center Hospital in Tokyo, Japan, between December 2005 and August 2010. The results of the total colonoscopy were known at the time of the CTC procedure and reading. Of the 161 LSTs detected on colonoscopy, 138 were observed and matched by CTC (86%). Of the 91 granular type LSTs (LST-Gs), 88 (97%) were observed and matched, while of the 70 non-granular type LSTs (LST-NGs), 50 (71%) were observed and matched by CTC (p < 0.0001). CTC enabled observation of 73% (22/30) of 20–29 mm, 83% (35/42) of 30–39 mm, 88% (49/56) of 40–59 mm, and 97% (32/33) of ≥60 mm tumors. The rate of observed LSTs by CTC was 86% (97% of LST-G, 71% of LST-NG) of the LSTs found during total colonoscopy
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