1,355 research outputs found

    Comment on ''Properties of highly clustered networks"

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    We consider a procedure for generating clustered networks previously reported by Newman [Phys. Rev. E 68, 026121 (2003)]. In the same study, clustered networks generated according to the proposed model have been reported to have a lower epidemic threshold under susceptible-infective-recovered-type network epidemic dynamics. By rewiring networks generated by this model, such that the degree distribution is conserved, we show that the lower epidemic threshold can be closely reproduced by rewired networks with close to zero clustering. The reported lower epidemic threshold can be explained by different degree distributions observed in the networks corresponding to different levels of clustering. Clustering results in networks with high levels of heterogeneity in node degree, a higher proportion of nodes with zero connectivity, and links concentrated within highly interconnected components of small size. Hence, networks generated by this model differ in both clustering and degree distribution, and the lower epidemic threshold is not explained by clustering alone

    Covering the 1972 Chisholm Campaign: Shaping Perceptions and Postponing Progress

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    In order to get their voices heard, groups with different interests and needs, often racially, socially, and economically marginalized groups, must take an active role in developing policies. Political representation is essential in articulating the need for change and then creating that change. Both women and African Americans have different significant problems gaining political office that their White male counterpoints do not. African American women are especially disadvantaged because of their challenges with the interlocking oppressions of both racism and sexism. A specific woman and candidacy that this study examines more closely was for the presidency. In 1972, Shirley Chisholm was the first Black female to run for the Democratic Party nomination for president. Although she was also the only Black and only female candidate competing in the primaries, both the National Organization for Women (NOW) and the Congressional Black Caucus did not endorse her. This content analysis looked specifically at the New York Times article coverage of her during her 1972 campaign. Questions that were sought to be answered included: How did the New York Times present Shirley Chisholm’s candidacy during her campaign for the Democratic presidential nomination in 1972? What would the reading audience be able to gather about her and her candidacy based on the information offered? Was she portrayed as a non-serious contender based on her race and/or gender? A content analysis was conducted to investigate these questions in order to identify areas that change needs to be made in order to increase the number of Black women elected to political office

    The connective tissue of physical computing.

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    This paper investigates the role of performativity, intersubjectivity and empathy in relational, participatory or computational art. Through the creation of sensorial, kinesthetic and immersive interfaces for the public to "perform" the work, participants can expand their somatic experiences to include looking, moving, touching, listening and other forms of sensing. They can enter into a sensuous continuum with the artwork, oscillating between the representation of another's experience and reflection on their own, so as to reconstitute new subjectivities

    It Happened in an Instant

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    Neuronal oscillations on an ultra-slow timescale: daily rhythms in electrical activity and gene expression in the mammalian master circadian clockwork

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Neuronal oscillations of the brain, such as those observed in the cortices and hippocampi of behaving animals and humans, span across wide frequency bands, from slow delta waves (0.1 Hz) to ultra-fast ripples (600 Hz). Here, we focus on ultra-slow neuronal oscillators in the hypothalamic suprachiasmatic nuclei (SCN), the master daily clock that operates on interlocking transcription-translation feedback loops to produce circadian rhythms in clock gene expression with a period of near 24 h (< 0.001 Hz). This intracellular molecular clock interacts with the cell's membrane through poorly understood mechanisms to drive the daily pattern in the electrical excitability of SCN neurons, exhibiting an up-state during the day and a down-state at night. In turn, the membrane activity feeds back to regulate the oscillatory activity of clock gene programs. In this review, we emphasise the circadian processes that drive daily electrical oscillations in SCN neurons, and highlight how mathematical modelling contributes to our increasing understanding of circadian rhythm generation, synchronisation and communication within this hypothalamic region and across other brain circuits.M.D.C.B is supported by the University ofExeter Medical School (UEMS). C.O.D’s work was partially supported bythe National Science Foundation under grant nos. DMS-1412877 and DMS-155237, and the U.S. Army Research Laboratory and the U.S. ArmyResearch Office under Grant No. W911NF-16-1-0584

    Secret Reception

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    Secret Reception combines art and bioacoustics to creatively engage the public in questions about sound reception in more-than-human worlds. This sonic art installation offers new paradigms for hearing through the design of haptic objects and tactile interfaces that use vibration to transmit sonic information. Drawing on scientific research that examines how insects detect sound through body parts, we transpose insect hearing to the human listening experience using sonic impulses that emulate the way insects receive them

    Network Symmetry and Binocular Rivalry Experiments

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    Hugh Wilson has proposed a class of models that treat higher-level decision making as a competition between patterns coded as levels of a set of attributes in an appropriately defined network (Cortical Mechanisms of Vision, pp. 399–417, 2009; The Constitution of Visual Consciousness: Lessons from Binocular Rivalry, pp. 281–304, 2013). In this paper, we propose that symmetry-breaking Hopf bifurcation from fusion states in suitably modified Wilson networks, which we call rivalry networks, can be used in an algorithmic way to explain the surprising percepts that have been observed in a number of binocular rivalry experiments. These rivalry networks modify and extend Wilson networks by permitting different kinds of attributes and different types of coupling. We apply this algorithm to psychophysics experiments discussed by Kovács et al. (Proc. Natl. Acad. Sci. USA 93:15508–15511, 1996), Shevell and Hong (Vis. Neurosci. 23:561–566, 2006; Vis. Neurosci. 25:355–360, 2008), and Suzuki and Grabowecky (Neuron 36:143–157, 2002). We also analyze an experiment with four colored dots (a simplified version of a 24-dot experiment performed by Kovács), and a three-dot analog of the four-dot experiment. Our algorithm predicts surprising differences between the three- and four-dot experiments

    Archaeological Investigation at Slayton House, 18AP74, Annapolis, Maryland

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    Archaeological investigation at the Slayton House site in Annapolis revealed evidence of occupation of the lot since the early 18th century. The intact late 18th century ground surfaces on which John Ridout built the row houses, and subsequent changes in the landscape and use of the yard as work space in the 19th century were discovered. There was ample visible evidence of the early 20th century landscape and use of the yard as a pleasure garden when excavation was started. Deposits inside the house were quite disturbed, but there was evidence of the work done by the African Americans who lived there. A number of artifacts were found which may indicate the slaves and free African Americans were practicing African-related folk beliefs. No further investigations are recommended for the site. However, if severe or deep ground-disturbing activities were to take place on the property, they should be monitored by a qualified archaeologist

    Minimizers with discontinuous velocities for the electromagnetic variational method

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    The electromagnetic two-body problem has \emph{neutral differential delay} equations of motion that, for generic boundary data, can have solutions with \emph{discontinuous} derivatives. If one wants to use these neutral differential delay equations with \emph{arbitrary} boundary data, solutions with discontinuous derivatives must be expected and allowed. Surprisingly, Wheeler-Feynman electrodynamics has a boundary value variational method for which minimizer trajectories with discontinuous derivatives are also expected, as we show here. The variational method defines continuous trajectories with piecewise defined velocities and accelerations, and electromagnetic fields defined \emph{by} the Euler-Lagrange equations \emph{% on} trajectory points. Here we use the piecewise defined minimizers with the Li{\'{e}}nard-Wierchert formulas to define generalized electromagnetic fields almost everywhere (but on sets of points of zero measure where the advanced/retarded velocities and/or accelerations are discontinuous). Along with this generalization we formulate the \emph{generalized absorber hypothesis} that the far fields vanish asymptotically \emph{almost everywhere%} and show that localized orbits with far fields vanishing almost everywhere \emph{must} have discontinuous velocities on sewing chains of breaking points. We give the general solution for localized orbits with vanishing far fields by solving a (linear) neutral differential delay equation for these far fields. We discuss the physics of orbits with discontinuous derivatives stressing the differences to the variational methods of classical mechanics and the existence of a spinorial four-current associated with the generalized variational electrodynamics.Comment: corrected minor typo: piecewise differentiable on closed instead of open interval
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