810 research outputs found

    A strong direct product theorem for quantum query complexity

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    We show that quantum query complexity satisfies a strong direct product theorem. This means that computing kk copies of a function with less than kk times the quantum queries needed to compute one copy of the function implies that the overall success probability will be exponentially small in kk. For a boolean function ff we also show an XOR lemma---computing the parity of kk copies of ff with less than kk times the queries needed for one copy implies that the advantage over random guessing will be exponentially small. We do this by showing that the multiplicative adversary method, which inherently satisfies a strong direct product theorem, is always at least as large as the additive adversary method, which is known to characterize quantum query complexity.Comment: V2: 19 pages (various additions and improvements, in particular: improved parameters in the main theorems due to a finer analysis of the output condition, and addition of an XOR lemma and a threshold direct product theorem in the boolean case). V3: 19 pages (added grant information

    Multiwavelength characterisation of an ACT-selected, lensed dusty star-forming galaxy at z=2.64

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    We present \ci\,(2--1) and multi-transition 12^{12}CO observations of a dusty star-forming galaxy, ACT\,J2029+0120, which we spectroscopically confirm to lie at zz\,=\,2.64. We detect CO(3--2), CO(5--4), CO(7--6), CO(8--7), and \ci\,(2--1) at high significance, tentatively detect HCO+^{+}(4--3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4--3) and CS(7--6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG/Seyfert or QSO host object in the taxonomy of the \textit{Herschel} Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T\sim117 K and nH2105n_{\text{H}_2}\sim10^5 cm3^{-3}, most consistent with a ULIRG/QSO object and the presence of high density tracers. We also find that the velocity width of the \ci\ line is potentially larger than seen in all CO transitions for this object, and that the LCI(21)/LCO(32)L'_{\rm C\,I(2-1)}/L'_{\rm CO(3-2)} ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.Comment: Accepted for publication in Ap

    Characterizing Atacama B-mode Search Detectors with a Half-Wave Plate

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    The Atacama B-Mode Search (ABS) instrument is a cryogenic (\sim10 K) crossed-Dragone telescope located at an elevation of 5190 m in the Atacama Desert in Chile that observed for three seasons between February 2012 and October 2014. ABS observed the Cosmic Microwave Background (CMB) at large angular scales (40<<50040<\ell<500) to limit the B-mode polarization spectrum around the primordial B-mode peak from inflationary gravity waves at 100\ell \sim100. The ABS focal plane consists of 480 transition-edge sensor (TES) bolometers. They are coupled to orthogonal polarizations from a planar ortho-mode transducer (OMT) and observe at 145 GHz. ABS employs an ambient-temperature, rapidly rotating half-wave plate (HWP) to mitigate systematic effects and move the signal band away from atmospheric 1/f1/f noise, allowing for the recovery of large angular scales. We discuss how the signal at the second harmonic of the HWP rotation frequency can be used for data selection and for monitoring the detector responsivities.Comment: 7 pages, 3 figures, conference proceedings submitted to the Journal of Low Temperature Detector

    ToMRobot 2.0: real mobility mechanism in MANET testbed using mobile robot

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    This paper is a continuation of our previous paper under the same topic, ToMRobot 1.0. Our main goal of developing ToMRobot 2.0 is to improve the ToMRobot 1.0 that we developed earlier. ToMRobot was developed because we think mobile robot technology is more practical than other approaches as a real world mobility mechanism in MANET testbed. But to develop our own mobile robot at low cost and at the same time not complex is very challenging. The challenge is overcome through the use of easy-to-use components, self-built components using 3D printers and the use of mobile robot designs that have proven to be easily developed, cheap and effective. The use of the Robot Operating System (ROS) as the main robot software framework greatly helps to reduce the complexity of developing control system for mobile robot

    Amifostine (wr-2721), A Cytoprotective Agent During High-dose Cyclophosphamide Treatment Of Non-hodgkin's Lymphomas: A Phase Ii Study.

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    Clinical trials indicate that amifostine may confer protection on various normal tissues without attenuating anti-tumor response. When administered prior to chemotherapy or radiotherapy, it may provide a broad spectrum of cytoprotection including against alkylating drugs. The mechanism of protection resides in the metabolism at normal tissue site by membrane-bound alkaline phosphatase. Toxicity of this drug is moderate with hypotension, nausea and vomiting, and hypocalcemia being observed. We report a phase II study using amifostine as a protective drug against high-dose cyclophosphamide (HDCY) (7 g/m2), used to mobilize peripheral blood progenitor cells (PBPC) and to reduce tumor burden. We enrolled 29 patients, 22 (75. 9%) affected by aggressive and 7 (24.1%) by indolent non-Hodgkin's lymphoma (NHL), who were submitted to 58 infusions of amifostine and compared them with a historical group (33 patients) affected by aggressive NHL and treated with VACOP-B followed by HDCY. The most important results in favor of amifostine were the reduction of intensity of cardiac, pulmonary and hepatic toxicity, and a significant reduction of frequency and severity of mucositis (P = 0. 04). None of the 29 patients died in the protected group, while in the historical group 2/33 patients died because of cardiac or pulmonary toxicity and 2 patients stopped therapy due to toxicity. Amifostine did not prevent the aplastic phase following HDCY. PBPC collection and hematological recovery were adequate in both groups. The number of CFU-GM (colony-forming units-granulocyte/macrophage) colonies and mononuclear cells in the apheresis products was significantly higher in the amifostine group (P = 0.02 and 0.01, respectively). Side effects were mild and easily controlled. We conclude that amifostine protection should be useful in HDCY to protect normal tissues, with acceptable side effects.33791-

    The long duration cryogenic system of the OLIMPO balloon--borne experiment: design and in--flight performance

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    We describe the design and in--flight performance of the cryostat and the self-contained 3^{3}He refrigerator for the OLIMPO balloon--borne experiment, a spectrophotometer to measure the Sunyaev-Zel'dovich effect in clusters of galaxies. The 3^{3}He refrigerator provides the 0.3 K operation temperature for the four arrays of kinetic inductance detectors working in 4 bands centered at 150, 250, 350 and 460 GHz. The cryostat provides the 1.65 K base temperature for the 3^{3}He refrigerator, and cools down the reimaging optics and the filters chain at about 2 K. The integrated system was designed for a hold time of about 15 days, to achieve the sensitivity required by the planned OLIMPO observations, and successfully operated during the first long-duration stratospheric flight of OLIMPO in July 2018. The cryostat features two tanks, one for liquid nitrogen and the other one for liquid helium. The long hold time has been achieved by means of custom stiff G10 fiberglass tubes support, which ensures low thermal conductivity and remarkable structural stiffness; multi--layer superinsulation, and a vapour cooled shield, all reducing the heat load on the liquid helium tank. The system was tested in the lab, with more than 15 days of unmanned operations, and then in the long duration balloon flight in the stratosphere. In both cases, the detector temperature was below 300 mK, with thermal stability better than ±\pm 0.5 mK. The system also operated successfully in the long duration stratospheric balloon flight
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