Rebag-Ware: Reputation-based Governance of Public Works

Reputation-based Governance (Rebag) is a framework to address governance problems that hinges on the reputation of the relevant actors. It functions thanks to an appropriate Web-based information system that encompasses the concept of Internet-based Reputation System, of which eBay represents an example. Rebag-Ware is a demonstrator of such an information system, showing an application of the proposed governance model to the management of public works. Rebag provides strong incentives to the actors of governance to behave efficiently and honestly. It allows for the computation of routine statistics that are used to fight corruption. Also, it allows for very advanced forms of public involvement that include participative planning and budgeting. In the paper, Rebag-Ware 1.0 is used to show some of the characteristics of the proposed model of governance. The site of the project is http://www.rebag.it. Rebag-Ware can be accessed at: http://fire.ei.unibo.it:8080/rebagware/

Photon-number resolving detector based on a series array of superconducting nanowires

We present the experimental demonstration of a superconducting photon number resolving detector. It is based on the series connection of N superconducting nanowires, each connected in parallel to an integrated resistor. The device provides a single voltage readout, proportional to the number of photons absorbed in distinct nanowires. Clearly separated output levels corresponding to the detection of n=1-4 photons are observed in a 4-element detector fabricated from an NbN film on GaAs substrate, with a single-photon system quantum efficiency of 2.6% at the wavelength of 1300nm. The series-nanowire structure is promising in view of its scalability to large photon numbers and high efficiencies.Comment: 12 pages, 6 figure

Effect of a submaxillary gland extract on Ehrlich tumor growth in mice

Ablation of host submaxillary glands modifies Ehrlich tumor growth and tumor-infiltrating leukocytes, possibly by modifications in the serum level of growth factors produced by this gland. To extend this research, 7-month-old male EPM-1 mice (N = 30) were divided into two groups: 1) inoculated with tumor cells previously incubated with submaxillary salivary gland extract (SGE) in PBS for 30 min at 37%; 2) inoculated with tumor cells previously incubated with PBS, under the same conditions. Animals were inoculated into the footpad with 40 µl of a suspension containing 4.5 x 107 tumor cells/ml, and footpad thickness was measured daily for 10 days. Sections and smears of tumor cells were prepared from the tumor mass to determine mitosis frequency, percent of tumor cells immunopositive to nerve (NGF) and epidermal (EGF) growth factors and percent of tumor-infiltrating leukocytes. The incubation of tumor cells with SGE produced a tumor reduction of about 30% in size (P<0.01). This effect was not related to loss of cell viability during incubation, but a 33% increase (P<0.05) in the percentage of dead or dying tumor cells and a 15% increase in the percent of NGF/EGF-positive tumor cells (P<0.01) were observed in vivo at the end of experiment. Tumor-infiltrating lymphocytes and mitosis frequency did not differ between groups. These data suggest a direct effect of factors present in SGE on tumor cells, which induce degeneration of tumor cells.Universidade PaulistaUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Ultrasensitive N-photon interferometric autocorrelator

We demonstrate a novel method to measure the Nth-order (N=1, 2, 3, 4) interferometric autocorrelation with high sensitivity and temporal resolution. It is based on the combination of linear absorption and nonlinear detection in a superconducting nanodetector, providing much higher efficiency than methods based on all-optical nonlinearities. Its temporal resolution is only limited by the quasi-particle energy relaxation time, which is directly measured to be in the 20 ps range for the NbN films used in this work. We present a general model of interferometric autocorrelation with these nonlinear detectors and discuss the comparison with other approaches and possible improvements

Optimal Amplitude Multiplexing of a Series of Superconducting Nanowire Single Photon Detectors

Integrated arrays of Superconducting Nanowire Single Photon Detectors (SNSPDs) have shown capabilities such as Photon Number Resolution, single photon imaging and coincidences detection, and can be effectively used also in other different applications related to quantum optics. The growing complexity of such applications requires the use of multiplexing schemes for the simultaneous readout of different detectors. A simple multiplexing scheme can be realized by arranging a series of SNSPDs elements, shunted by appropriate resistances. The goal of this work is to investigate and optimize this scheme, developing a general method able to identify the optimal sets of shunting resistences for any different application. The methodology obtained is very general, and can be extended to other detection systems