826 research outputs found

    Wide angle long eye relief eyepiece Patent

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    Wide angle eyepiece with long eye-relief distanc

    Phase separation in transparent liquid-liquid miscibility gap systems

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    A program to be carried out on transparent liquid-phase miscibility gap materials was developed for the purpose of acquiring additional insight into the separation process occurring in these systems. The transparency feature allows the reaction to be viewed directly through light scattering and holographic methods

    Diffusive hidden Markov model characterization of DNA looping dynamics in tethered particle experiments

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    In many biochemical processes, proteins bound to DNA at distant sites are brought into close proximity by loops in the underlying DNA. For example, the function of some gene-regulatory proteins depends on such DNA looping interactions. We present a new technique for characterizing the kinetics of loop formation in vitro, as observed using the tethered particle method, and apply it to experimental data on looping induced by lambda repressor. Our method uses a modified (diffusive) hidden Markov analysis that directly incorporates the Brownian motion of the observed tethered bead. We compare looping lifetimes found with our method (which we find are consistent over a range of sampling frequencies) to those obtained via the traditional threshold-crossing analysis (which can vary depending on how the raw data are filtered in the time domain). Our method does not involve any time filtering and can detect sudden changes in looping behavior. For example, we show how our method can identify transitions between long-lived, kinetically distinct states that would otherwise be difficult to discern

    Single crystals of metal solid solutions

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    The following definitions were sought in the research on single crystals of metal solid solutions: (1) the influence of convection and/or gravity present during crystallization on the substructure of a metal solid solution; (2) the influence of a magnetic field applied during crystallization on the substructure of a metal solid solution; and (3) requirements for a space flight experiment to verify the results. Growth conditions for the selected silver-zinc alloy system are described, along with pertinent technical and experimental details of the project

    Secure Two-Party Computation over Unreliable Channels

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    We consider information-theoretic secure two-party computation in the plain model where no reliable channels are assumed, and all communication is performed over the binary symmetric channel (BSC) that flips each bit with fixed probability. In this reality-driven setting we investigate feasibility of communication-optimal noise-resilient semi-honest two-party computation i.e., efficient computation which is both private and correct despite channel noise. We devise an information-theoretic technique that converts any correct, but not necessarily private, two-party protocol that assumes reliable channels, into a protocol which is both correct and private against semi-honest adversaries, assuming BSC channels alone. Our results also apply to other types of noisy-channels such as the elastic-channel. Our construction combines tools from the cryptographic literature with tools from the literature on interactive coding, and achieves, to our knowledge, the best known communication overhead. Specifically, if ff is given as a circuit of size ss, our scheme communicates O(s+Îș)O(s + \kappa) bits for Îș\kappa a security parameter. This improves the state of the art (Ishai et al., CRYPTO\u27 11) where the communication is O(s)+poly(Îș⋅depth(s))O(s) + \text{poly}(\kappa \cdot \text{depth}(s))

    Percolation in the classical blockmodel

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    Classical blockmodel is known as the simplest among models of networks with community structure. The model can be also seen as an extremely simply example of interconnected networks. For this reason, it is surprising that the percolation transition in the classical blockmodel has not been examined so far, although the phenomenon has been studied in a variety of much more complicated models of interconnected and multiplex networks. In this paper we derive the self-consistent equation for the size the global percolation cluster in the classical blockmodel. We also find the condition for percolation threshold which characterizes the emergence of the giant component. We show that the discussed percolation phenomenon may cause unexpected problems in a simple optimization process of the multilevel network construction. Numerical simulations confirm the correctness of our theoretical derivations.Comment: 7 pages, 6 figure

    Measurement of Sibling Violence: A Two-Factor Model of Severity

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    The measurement of violence is a major challenge in aggression research. Because of the heterogeneous nature of violent behavior, problems arise when applying blanket measures to inherently distinct subtypes of aggression. Incidents of intersibling violence (ISV) exacerbate these problems because siblinghood represents a unique offender–victim situation. This research explored whether an existing two-factor model for severe violence found in a sample of 250 adult offenders (age M = 26.8, SD = 5.9) could be generalized to deliberate severe ISV in a sample of 111 young offenders (age M = 14.83, SD = 1.45). Exploratory factor analysis revealed a two-factor model encompassing severe ISV perpetration with weapon use (Factor 1) and severe ISV perpetration without weapon use (Factor 2). The results provide strong empirical support for the two-factor model of violence severity previously established with adult offenders. This analysis demonstrates construct validity of the severity measures among the different types of offenders studied and provides support for generalization across populations
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