Efficient detection of contagious outbreaks in massive metropolitan encounter networks

Physical contact remains difficult to trace in large metropolitan networks, though it is a key vehicle for the transmission of contagious outbreaks. Co-presence encounters during daily transit use provide us with a city-scale time-resolved physical contact network, consisting of 1 billion contacts among 3 million transit users. Here, we study the advantage that knowledge of such co-presence structures may provide for early detection of contagious outbreaks. We first examine the "friend sensor" scheme --- a simple, but universal strategy requiring only local information --- and demonstrate that it provides significant early detection of simulated outbreaks. Taking advantage of the full network structure, we then identify advanced "global sensor sets", obtaining substantial early warning times savings over the friends sensor scheme. Individuals with highest number of encounters are the most efficient sensors, with performance comparable to individuals with the highest travel frequency, exploratory behavior and structural centrality. An efficiency balance emerges when testing the dependency on sensor size and evaluating sensor reliability; we find that substantial and reliable lead-time could be attained by monitoring only 0.01% of the population with the highest degree.Comment: 4 figure

Guttate leukoderma and acrokeratosis verruciformis of Hopf: a rare combination in Darier disease

A distinct Darier phenotype presenting with confetti-like hypopigmented macules was first described in 1965. Designated as "guttate leukoderma," this skin finding is a rarely-reported presentation of Darier disease. It has been theorized that the mutation in ATP2A2 causes defective E-cadherin, which in turn disrupts the adhesion of melanocytes to keratinocytes, thus leading to impaired dendrite formation, hindered melanin transfer, and ultimately to melanocyte apoptosis. Herein, we contribute a case of a 56-year old woman who presented with the rarely-described guttate leukoderma of Darier disease and acrokeratosis verruciformis of Hopf

A typology of job search sources: Exploring the changing nature of job search networks

This study explored American job seekers’ network of information sources using a random sample. Results revealed a pattern that job seekers segmented information sources by social (i.e. personal and professional acquaintances, family, and friends), formal (i.e. employment agencies, printed advertisements, and career events), and online (i.e. online pages and social network sites) types. Although online sources were particularly central in the network, job seekers who used one source type did so at the expense of other types of sources. Older and poorer job seekers were more likely to use formal sources, while online sources were used more by job seekers with higher education and Internet efficacy. The discussion offers advice for job seekers and those who coach job search. This study extends strength of weak ties theory by demonstrating the importance of online sources in job search

Few-Body Systems Composed of Heavy Quarks

Within the past ten years many new hadrons states were observed experimentally, some of which do not fit into the conventional quark model. I will talk about the few-body systems composed of heavy quarks, including the charmonium-like states and some loosely bound states.Comment: Plenary talk at the 20th International IUPAP Conference on Few-Body Problems in Physics, to appear in Few Body Systems (2013