Small-worlds: Beyond Social Networking

Small-world phenomena were initially studied in the 1960s through a series of social network experiments, and are, as evidenced by the game The six degrees of Kevin Bacon , even part of our pop-culture. Recently, mathematicians and physicists have shown that most small-world phenomena are expected consequences of the mathematical properties of certain networks -- known as {\em small-world networks}. In this paper, we survey some recent mathematical developments dealing with small-world networks, as well as present a new small-world network model and discuss some new ideas for decentralized searching. The goal is to give the reader a sense of the importance of small-world networks, and some of the useful applications dealing with these networks

Meis1 specifies positional information in the retina and tectum to organize the zebrafish visual system

<p>Abstract</p> <p>Background</p> <p>During visual system development, multiple signalling pathways cooperate to specify axial polarity within the retina and optic tectum. This information is required for the topographic mapping of retinal ganglion cell axons on the tectum. Meis1 is a TALE-class homeodomain transcription factor known to specify anterior-posterior identity in the hindbrain, but its role in visual system patterning has not been investigated.</p> <p>Results</p> <p><it>meis1 </it>is expressed in both the presumptive retina and tectum. An analysis of retinal patterning reveals that Meis1 is required to correctly specify both dorsal-ventral and nasal-temporal identity in the zebrafish retina. Meis1-knockdown results in a loss of <it>smad1 </it>expression and an upregulation in <it>follistatin </it>expression, thereby causing lower levels of Bmp signalling and a partial ventralization of the retina. Additionally, Meis1-deficient embryos exhibit ectopic Fgf signalling in the developing retina and a corresponding loss of temporal identity. Meis1 also positively regulates <it>ephrin </it>gene expression in the tectum. Consistent with these patterning phenotypes, a knockdown of Meis1 ultimately results in retinotectal mapping defects.</p> <p>Conclusions</p> <p>In this work we describe a novel role for Meis1 in regulating Bmp signalling and in specifying temporal identity in the retina. By patterning both the retina and tectum, Meis1 plays an important role in establishing the retinotectal map and organizing the visual system.</p

Isomorphism of graph classes related to the circular-ones property

We give a linear-time algorithm that checks for isomorphism between two 0-1 matrices that obey the circular-ones property. This algorithm leads to linear-time isomorphism algorithms for related graph classes, including Helly circular-arc graphs, \Gamma-circular-arc graphs, proper circular-arc graphs and convex-round graphs.Comment: 25 pages, 9 figure

The characteristics and treatment needs of fire setters with intellectual disability: descriptive data and comparisons between offence type

Purpose: Fire setters who have an intellectual disability (ID) are often identified as posing a particular danger to the community although relatively little is known about their characteristics, treatment, and support needs. Methodology: This study describes the characteristics of 134 residents of low, medium, and high security ID facilities in the United Kingdom who have either an index offence of arson, comparing them with those who have a violentn index offence, involving either violent or a sexual indexal offenceding. Findings: Index arson offenders who had an ID had multiple prior convictions, a history of violent offending, and a high likelihood of having a comorbid mental disorder. There were many shared characteristics across the three groups. Practical implications: The current study suggests that offenders who have ID who set fires have treatment needs that are similar to those of violent and sex offenders. It follows that fire setters who have an ID may also benefit from participating in more established offending behaviour treatment programs, such as cognitive behaviour therapy programs, developed for other types of offender. Originality: This study is one of the few which has investigated the characteristics and treatment needs of persons who have an ID who set fires. In particular, it is one of the first to compare the characteristics and treatment needs for persons with ID who set fires, to those who have committed violent and sexual offences

The Path to Buried Treasure: Paving the Way to the FLAMINGOS-2 Galactic Center Survey with IR and X-ray Observations

I describe the IR and X-ray campaign we have undertaken to determine the nature of the faint discrete X-ray source population discovered by Chandra in the Galactic Center. These results will provide the input to the FLAMINGOS-2 Galactic Center Survey (F2GCS). With FLAMINGOS-2's multi-object IR spectrograph we will obtain 1000s of IR spectra of candidate X-ray source counterparts, allowing us to efficiently identify the nature of these sources, and thus dramatically increase the number of known X-ray binaries and CVs in the Milky Way.Comment: To be published in Proceedings of 'A Population Explosion: The Nature and Evolution of X-ray Binaries in Diverse Environments', 28 Oct - 2 Nov, St. Pete Beach, FL; eds. R.M. Bandyopadhyay, S. Wachter, D. Gelino, C.R. Gelino; AIP Conference Proceedings Serie

The return on investment for taxi companies transitioning to electric vehicles A case study in San Francisco

Abstract We study whether taxi companies can simultaneously save petroleum and money by transitioning to electric vehicles. We propose a process to compute the return on investment of transitioning a taxi corporation&apos;s fleet to electric vehicles. We use Bayesian data analysis to infer the revenue changes associated with the transition. We do not make any assumptions about the vehicles&apos; mobility patterns; instead, we use a time-series of GPS coordinates of the company&apos;s existing petroleum-based vehicles to derive our conclusions. As a case study, we apply our process to a major taxi corporation, Yellow Cab San Francisco (YCSF). Using current prices, we find that transitioning their fleet to battery electric vehicles and plug-in hybrid electric vehicles is profitable for the company. Furthermore, given that gasoline prices in San Francisco are only 5.4 % higher than the rest of the United States, but electricity prices are 75 % higher; taxi companies with similar practices and mobility patterns in other cities are likely to profit more than YCSF by transitioning to electric vehicles

Who Gives a Trump? Evidence of Framing Effects in Tax Policy

We use a framed survey to measure how associating the name “Trump” with the Tax Cuts and Jobs Act (TCJA) affects people’s satisfaction of said Act. Our research included 72 participant clients from a Volunteer Income Tax Assistants (VITA) program, who were asked to provide baseline data regarding political affiliation and attitudes prior to having tax returns completed. We find that using the name “Trump” with people who self-identify as Republican results in more satisfaction with the Act, whereas, for people with who do not self-identify as Republican, association with the name “Trump” does not precipitate stronger or weaker satisfaction with the Act

Touchstone Stars: Highlights from the Cool Stars 18 Splinter Session

We present a summary of the splinter session on "touchstone stars" -- stars with directly measured parameters -- that was organized as part of the Cool Stars 18 conference. We discuss several methods to precisely determine cool star properties such as masses and radii from eclipsing binaries, and radii and effective temperatures from interferometry. We highlight recent results in identifying and measuring parameters for touchstone stars, and ongoing efforts to use touchstone stars to determine parameters for other stars. We conclude by comparing the results of touchstone stars with cool star models, noting some unusual patterns in the differences.Comment: Proceedings of the 18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Eds G. van Belle & H. Harri

Software-defined networking for ubiquitous healthcare service delivery

The growth of the mobile, portable devices and the server-to-server communication through cloud computing increase the network traffic. The dependence of the ubiquitous healthcare service delivery on the network connectivity creates failures that may interrupt or delay the treatment plan with adverse effects in patients’ quality of life even leading to mortality. In the present work, we propose the incorporation of Software Defined Networking (SDN) features in the healthcare domain in order to provide the appropriate bandwidth and guarantee the accurate real time medical data transmission independently of the connectivity of the ISP provider. The SDN controller monitors the network traffic and specifies how traffic should be routed providing load balancing, lower delays and better performance. Finally, the proposed healthcare architecture addresses the SDN scalability challenge by incorporating the logically centralized control plane using multiple distributed controllers. A 2-tier hierarchical overlay is formed among SDN controllers following the principles of peer-to-peer networking