On 22--23 June 2001, the Johns Hopkins Center for Civilian Biodefense Strategies, in collaboration with the Center for Strategic and International Studies, the Analytic Services Institute for Homeland Security, and the Oklahoma National Memorial Institute for the Prevention of Terrorism, held a senior-level exercise entitled "Dark Winter" that simulated a covert smallpox attack on the United St...

OBJECTIVES Optimum viewing conditions facilitate identification of radiographic details and decrease the need for retakes, patients' costs and radiation dose. This study sought to evaluate the effects of different viewing conditions on radiographic interpretation. MATERIALS AND METHODS This diagnostic study was performed by evaluating radiograph of a 7mm-thick aluminum block, in which 10 hole...

The nature of Dark Matter (DM) is one of the most intriguing questions of modern physics. Its resolution would have a profound impact on the development of particle physics beyond its Standard Model (SM). Although the possibility of having massive compact halo objects (MACHOs) as a dominant form of DM is still under debates (see recent discussion in [1] and references therein), it is widely bel...

Bunning suggested that circadian rhythms provide the basis for time measurement in the photoperiodic responses of plants (2). A classic example is found in Glycine max. L. Merr. (Biloxi soybean), whose flowering response occurs in a rhythmical form having peaks of flowering that were approximately 24 hr apart (6). Recentlv Moore et al. (5) reported that Xanthiuim pensylvanicum did not exhibit a...

In a recent paper, Hawkins (1997) argues on the basis of statistical studies of double-image gravitational lenses and lens candidates that a large population of dark lenses exists and that these outnumber galaxies with more normal mass-to-light ratios by a factor of 3:1. If correct, this is a very important result for many areas of astronomy including galaxy formation and cosmology. In this pap...

The physical process leading to the acceleration of the expansion of the universe is unknown. It may involve new high energy physics or extensions to gravitation. Calling this generically dark energy, we examine the consistencies and relations between these two approaches, showing that an effective equation of state function w(z) is broadly useful in describing the properties of the dark energy...

We construct a Dark Matter (DM) annihilation module that can encompass the predictions from a wide array of models built to explain the recently reported PAMELA and ATIC/PPB-BETS excesses. We present a detailed analysis of the injection spectrums for DM annihilation and quantitatively demonstrate effects that have previously not been included from the particle physics perspective. With this mod...

In a galactic halo like the Milky Way, bosonic dark matter particles lighter than about $30$ eV have de Broglie wavelength larger average inter-particle separation and are therefore well described as set of classical waves. This applies to, for instance, QCD axion to axion-like such fuzzy matter. We show that interference waves inside inevitably leads vortices, locations where chance destructiv...

A type of photoheterotrophic bacteria contain a transmembrane light-driven proton pump called proteorhodopsins (PRs). Due to the prevalence of these organisms in the upper water column of the World's Ocean, and their potential for light-driven ATP generation, they have been suggested to significantly influence energy and matter flows in the biosphere. To date, evidence for the significance of t...