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Superconducting nanowire single-photon detectors (SNSPDs) are typical switching devices capable of detecting single photons with almost 100% detection efficiency. However, they cannot determine the exact number of incident photons during a detection event. Multi-pixel SNSPDs employing multiple read-out channels can provide photon number resolvability (PNR), but they require increased cooling power and costly multi-channel electronic systems. In this work, a single-flux quantum (SFQ) circuit is employed, and PNR based on multi-pixel SNSPDs is successfully demonstrated. A multi-input magnetically coupled DC/SFQ converter (MMD2Q) circuit with a mutual inductance M is used to combine and record signals from a multi-pixel SNSPD device. The designed circuit is capable of discriminating the amplitude of the combined signals in accuracy of Φ 0/ M with Φ 0 being a single magnetic flux quantum. By employing the MMD2Q circuit, the discrimination of up to 40 photons can be simulated. A 4-parallel-input MMD2Q circuit is fabricated, and a PNR of 3 is successfully demonstrated for an SNSPD array with one channel reserved for the functional verification. The results confirm that an MMD2Q circuit is an effective tool for implementing PNR with multi-pixel SNSPDs. [ABSTRACT FROM AUTHOR]

Author(s): Longyue L. Cao [1, 2]; Dario F. Riascos-Bernal [1, 2]; Prameladevi Chinnasamy [1, 2]; Charlene M. Dunaway [1, 2]; Rong Hou [1, 2]; Mario A. Pujato [3]; Brian P. [...]

The significance of cadherin superfamily proteins in vascular smooth muscle cell (VSMC) biology is undefined. Here we describe recent studies of the Fat1 protocadherin. Fat1 expression in VSMCs increases significantly after arterial injury or growth factor stimulation. Fat1 knockdown decreases VSMC migration in vitro, but surprisingly, enhances cyclin D1 expression and proliferation. Despite limited similarity to classical cadherins, the Fat1 intracellular domain ([Fat1.sub.IC]) interacts with [beta]-catenin, inhibiting both its nuclear localization and transcriptional activity. Fat1 undergoes cleavage and [Fat1.sub.IC] species localize to the nucleus; .however, inhibition of the cyclin D1 promoter by truncated [Fat1.sub.IC] proteins corresponds to their presence outside the nucleus, which argues against repression of [beta]-catenin-dependent transcription by nuclear [Fat1.sub.LC]. These findings extend recent observations about Fat1 and migration in other cell types, and demonstrate for the first time its antiproliferative activity and interaction with [beta]-catenin. Because it is induced after arterial injury, Fat1 may control VSMC functions central to vascular remodeling by facilitating migration and limiting proliferation.

Age is a key factor affecting sexual selection, as many physical and social traits are age-related. Although studies of primate mate choice often consider particular age-related traits, few consider the collective effects of male age. We tested the hypothesis that female golden snub-nosed monkeys Rhinopithecus roxellana prefer prime aged males (10–15 years) over younger and older males. We examined a habituated, provisioned troop during a 3-year study in the Qinling Mountains, China. Prime age males were more likely to be resident males of 1-male units (OMUs) than males of other ages. Since females are free to transfer between OMUs, the number of females per OMU can be indicative of female preferences. We examined the number of females per OMU, and found that it increased with resident male age up to 7–8 years, and declined after 12 years, such that prime age resident males had more females than other resident males. Females also initiated extra-unit copulations with high-ranking prime age males at significantly higher rates than with other males. Nevertheless, females tended to transfer from OMUs with high-ranking, older resident males to those with low-ranking, younger resident males. Thus, females appear to use different strategies when choosing social mates and extra-unit mates (i.e. different social contexts). We speculate that females may perceive early signs of aging in males and trade off the benefits and costs of high rank versus male senescence. This study lays the groundwork for future studies that examine possible direct and indirect benefits of such strategies. [ABSTRACT FROM AUTHOR]

An efficient methodology for the synthesis of dibenzo[ a , c ]carbazoles via annulation of 2,3-diphenyl-1 H -indoles in EtOH under UV light irradiation (λ = 365 nm) along with hydrogen evolution is described. This method exhibits the advantages of mild reaction conditions, no requirement of any oxidants and catalysts, and release of hydrogen as the only byproduct. Notably, the mechanism investigation confirms that the trans -4b,8a-dihydro-9 H -dibenzo[ a , c ]carbazole intermediate could convert into cis -4b,8a-dihydro-9 H -dibenzo[ a , c ]carbazole, which relies on the nitrogen atom of the indole ring. This is followed by intramolecular dehydrogenation which yields the dibenzo[ a , c ]carbazoles. [ABSTRACT FROM AUTHOR]