Macro Dark Matter

Dark matter is a vital component of the current best model of our universe, $\Lambda$CDM. There are leading candidates for what the dark matter could be (e.g. weakly-interacting massive particles, or axions), but no compelling observational or experimental evidence exists to support these particular candidates, nor any beyond-the-Standard-Model physics that might produce such candidates. This suggests that other dark matter candidates, including ones that might arise in the Standard Model, should receive increased attention. Here we consider a general class of dark matter candidates with characteristic masses and interaction cross-sections characterized in units of grams and cm$^2$, respectively -- we therefore dub these macroscopic objects as Macros. Such dark matter candidates could potentially be assembled out of Standard Model particles (quarks and leptons) in the early universe. A combination of Earth-based, astrophysical, and cosmological observations constrain a portion of the Macro parameter space. A large region of parameter space remains, most notably for nuclear-dense objects with masses in the range $55 - 10^{17}$ g and $2\times10^{20} - 4\times10^{24}$ g, although the lower mass window is closed for Macros that destabilize ordinary matter.Comment: 13 pages, 1 table, 4 figures. Submitted to MNRAS. v3: corrected small errors and a few points were made more clear, v4: included CMB bounds on dark matter-photon coupling from Wilkinson et al. (2014) and references added. Final revision matches published versio

Evaluating the efficacy of grafting the facial gap at immediately placed implants in the anterior maxilla: a systematic review and randomized controlled trial

Immediate implant placement is an accepted and widely utilized treatment modality for tooth replacement following extraction. Survival and success are comparable to implant placement in healed ridges. However, the best methods for achieving predictable soft tissue esthetics are still up for debate. Contemporary surgical strategy often leaves a facial gap anterior to the implant, between it and the buccal plate. The ideal management of this gap--with regards to grafting or not--has not been clearly defined. There are two general aims to this thesis: to review immediate implant literature that examines esthetic outcomes based on facial gap grafting status, and to carry out a randomized, controlled trial evaluating whether grafting the facial gap between the implant and buccal bone at the time of immediate implant placement will improve tissue preservation when compared to a no-grafting protocol.Master of Scienc

Flutes, Pianos, and Machines: Compositions for Instruments and Electronic Sounds

This dissertation is comprised of three recent original compositions- Dis Un Il Im Ir, In sin fin bin din bin fin sin in, and Percussion+Guitar. Each work has a unique approach to integrating instrumental performance with humans and computers. The essay component details unique computer-performer interactions I’ve developed to overcome complications in the concert presentation of previous acousmatic and mixed media works. The three works discussed here are related in their instrumentation and compositional style. Dis Un Il Im Ir (2013), for flute, piano, and MIDI keyboard, experiments with the limit of human virtuosity and attempts to extend its affect via sound synthesis and digital samples. In sin fin bin din bin fin sin in (2104), for four computer-controlled pianos with electronic sounds, focuses on repeated melodic and harmonic patterns explored in previous works contrasted with unruly mechanical spasms. Percussion+Guitar (2015), for two computer-controlled flutes (contrary to the title), features a specially designed instrument built at Columbia University’s Computer Music Center. This composition is a duet with a structure defined by heightened rhythmic angularity and blazing fast speeds demonstrating the computer's special skills as a performer. The essay part of this dissertation includes an analysis of the pitches, rhythms, and gestures where appropriate. I provide details about the artistic uses of software and hardware for each project. I trace my artistic inspirations for composing with and for computers and robots to my experiences in acousmatic music, pop production, and hands-on music making. I describe my process of organizing contrasting sounds into form-bearing elements- an approach inspired by Pierre Schaeffer’s typomorphology of sound objects later revisited by Lasse Thoresen. The paper concludes with a brief discussion about future works

Photon number resolving detection using time-multiplexing

Detectors that can resolve photon number are needed in many quantum information technologies. In order to be useful in quantum information processing, such detectors should be simple, easy to use, and be scalable to resolve any number of photons, as the application may require great portability such as in quantum cryptography. Here we describe the construction of a time-multiplexed detector, which uses a pair of standard avalanche photodiodes operated in Geiger mode. The detection technique is analysed theoretically and tested experimentally using a pulsed source of weak coherent light.Comment: 20 pages, 14 figures, accepted to Journal of Modern Optic

Effects Of Tropical Storm Agnes On Zooplankton In The Lower Chesapeake Bay

Sampling techniques in use since August 1971 were employed to study effects of Tropical Storm Agnes on lower Chesapeake Bay zooplankton following the storm\u27s passage on June 21, 1972. Mean catches of copepods, cladocerans, barnacle larvae, decapod larvae, chaetognaths, and fish eggs and larvae were calculated for the entire study area and six subareas from 8 bongo net collections. A single subarea was selected for specific identifications within major taxa of zooplankton.https://scholarworks.wm.edu/vimsbooks/1072/thumbnail.jp