Complete physical simulation of the entangling-probe attack on the BB84 protocol

We have used deterministic single-photon two qubit (SPTQ) quantum logic to implement the most powerful individual-photon attack against the Bennett-Brassard 1984 (BB84) quantum key distribution protocol. Our measurement results, including physical source and gate errors, are in good agreement with theoretical predictions for the Renyi information obtained by Eve as a function of the errors she imparts to Alice and Bob's sifted key bits. The current experiment is a physical simulation of a true attack, because Eve has access to Bob's physical receiver module. This experiment illustrates the utility of an efficient deterministic quantum logic for performing realistic physical simulations of quantum information processing functions.Comment: 4 pages, 5 figure

An experimental evaluation of the instrumented flux synthesis method

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1995.Includes bibliographical references (leaves 258-260).by Jeffrey C. Hughes.Ph.D

Relations Between Molecular Cloud Structure Sizes and Line Widths in the Large Magellanic Cloud

We present a comparative study of the size-line width relation for substructures within six molecular clouds in the Large Magellanic Cloud (LMC) mapped with the Atacama Large Millimeter/submillimeter Array (ALMA). Our sample extends our previous study, which compared a Planck detected cold cloud in the outskirts of the LMC with the 30 Doradus molecular cloud and found the typical line width for 1 pc radius structures to be 5 times larger in 30 Doradus. By observing clouds with intermediate levels of star formation activity, we find evidence that line width at a given size increases with increasing local and cloud-scale 8${\mu}$m intensity. At the same time, line width at a given size appears to independently correlate with measures of mass surface density. Our results suggest that both virial-like motions due to gravity and local energy injection by star formation feedback play important roles in determining intracloud dynamics.Comment: 20 pages, to appear in ApJ. Data presented in this paper can be found at https://mmwave.astro.illinois.edu/almalmc

The protective effects of plasma gelsolin on stroke outcome in rats

<p>Abstract</p> <p>Background</p> <p>To date, recombinant tissue plasminogen activator (rtPA) is the only approved drug for ischemic stroke. It is intravenously administered functioning as a thrombolytic agent and is used to obtain reperfusion of the affected area of the brain. Excitotoxicity, inflammation and apoptosis are all involved in delayed neuronal death following stroke and offer multiple opportunities to intervene with neuroprotective agents. Gelsolin (GSN) is an actin- and calcium-binding protein mediating the disassembly of actin filaments and activity of calcium channels. It also functions as a regulator of apoptosis and inflammatory responses. This study tests the hypothesis that increasing the concentration of the form of GSN known as plasma GSN (pGSN) near an infarct will provide neuroprotection following ischemic stroke.</p> <p>Methods</p> <p>We induced middle cerebral artery occlusion (MCAO) in male rats via intracranial injection of endothelin-1 (ET-1), a potent vasoconstrictor, and then treated with local delivery of pGSN. Whole brain laser Doppler perfusion imaging was performed through the skull to assess MCAO effectiveness. Cylinder and vibrissae tests evaluated sensorimotor function before and 72 h after MCAO. Infarct volumes were examined 72 h after MCAO via 2, 3, 5-triphenyltetrazolium chloride (TTC) assay.</p> <p>Results</p> <p>Estimates of relative cerebral perfusion were significantly decreased in all groups receiving MCAO with no differences detected between treatments. Despite equivalent initial strokes, the infarct volume of the pGSN treatment group was significantly reduced compared with the untreated MCAO rats at 72 h. ET-1 induced significant deficits in both cylinder and vibrissae tests while pGSN significantly limited these deficits.</p> <p>Conclusion</p> <p>Gelsolin could be a promising drug for protection against neurodegeneration following ischemic stroke.</p

A GC-MS Method for the Determination of Isoxsuprine in Biological Fluids of the Horse Utilizing Electron Impact Ionization

Isoxsuprine is used to treat navicular disease and other lower-limb problems in the horse. Isoxsuprine is regulated as a class 4 compound by the Association of Racing Commissioners, International (ARCI) and, thus, requires regulatory monitoring. A gas chromatography-mass spectrometry method utilizing electron impact ionization was developed and validated for the quantitation of isoxsuprine in equine plasma or equine urine. The method utilized robotic solid-phase extraction and tri-methyl silyl ether products of derivatization. Products were bis-trimethylsilyl (TMS) isoxsuprine and tris-TMS ritodrine, which released intense quantifier ions m/z 178 for isoxsuprine and m/z 236 for ritodrine that were products of C-C cleavage. To our knowledge, this procedure is faster and more sensitive than other methods in the literature. Concentrations in urine and plasma of isoxsuprine were determined from a calibrator curve that was generated along with unknowns. Ritodrine was used as an internal standard and was, therefore, present in all samples, standards, and blanks. Validation data was also collected. The limit of detection of isoxsuprine in plasma was determined to be 2 ng/mL, the limit of quantitation of isoxsuprine in plasma was determined to be \u3c 5 ng/mL. The mean coefficient of determination for the calibrator curves for plasma was 0.9925 ± 0.0052 and for calibrator curves for urine 0.9904 ± 0.0075. The recovery efficiencies at concentrations of 50, 200, and 300 ng/mL were 76%, 73%, and 76%, respectively, in plasma and 92%, 89% and 91% in urine

Anomalously high photocurrents in nanostructured electrodes : a new local microchip power source.

An increase in photocurrent has been observed at silicon electrodes coated with nanostructured porous silica films as compared to bare, unmodified silicon. Ultimately, to utilize this effect in devices such as sensors or microchip power supplies, the physical phenomena behind this observation need to be well characterized. To this end, Electrochemical Impedance Spectroscopy (EIS) was used to characterize the effect of surfactant-templated mesoporous silica films deposited onto silicon electrodes on the electrical properties of the electrode space-charge region in an aqueous electrolyte solution, as the electrical properties of this space-charge region are responsible for the photobehavior of semiconductor devices. A significant shift in apparent flat-band potential was observed for electrodes modified with the silica film when compared to bare electrodes; the reliability of this data is suspect, however, due to contributions from surface states to the overall capacitance of the system. To assist in the interpretation of this EIS data, a series of measurements at Pt electrodes was performed with the hope of decoupling electrode and film contributions from the EIS spectra. Surprisingly, the frequency-dependent impedance data for Pt electrodes coated with a surfactant-templated film was nearly identical to that observed for bare Pt electrodes, indicating that the mesoporous film had little effect on the transport of small electrolyte ions to the electrode surface. Pore-blocking agents (tetraalkylammonium salts) were not observed to inhibit this transport process. However, untemplated (non-porous) silica films dramatically increased film resistance, indicating that our EIS data for the Pt electrodes is reliable. Overall, our preliminary conclusion is that a shift in electrical properties in the space-charge region induced by the presence of a porous silica film is responsible for the increase in observed photocurrent