Multiwavelength Analysis of Dark Matter Annihilation and RX-DMFIT

Dark matter (DM) particles are predicted by several well motivated models to yield Standard Model particles through self-annihilation that can potentially be detected by astrophysical observations. In particular, the production of charged particles from DM annihilation in astrophysical systems that contain magnetic fields yields radio emission through synchrotron radiation and X-ray emission through inverse Compton scattering of ambient photons. We introduce RX-DMFIT, a tool used for calculating the expected secondary emission from DM annihilation. RX-DMFIT includes a wide range of customizable astrophysical and particle parameters and incorporates important astrophysics including the diffusion of charged particles, relevant radiative energy losses, and magnetic field modelling. We demonstrate the use and versatility of RX-DMFIT by analyzing the potential radio and X-ray signals for a variety of DM particle models and astrophysical environments including galaxy clusters, dwarf spheroidal galaxies and normal galaxies. We then apply RX-DMFIT to a concrete example using Segue I radio data to place constraints for a range of assumed DM annihilation channels. For WIMP models with $M_{\chi} \leq 100$ GeV and assuming weak diffusion, we find that the the leptonic $\mu^+\mu^-$ and $\tau^+\tau^-$ final states provide the strongest constraints, placing limits on the DM particle cross-section well below the thermal relic cross-section, while even for the $b\bar{b}$ channel we find limits close to the thermal relic cross-section. Our analysis shows that radio emission provides a highly competitive avenue for dark matter searches.Comment: 21 pages, 9 figures, 2 tables, corrections to figures, additional text, accepted to JCA

Observations of Ion Density and Temperature around the International Space Station During two Geomagnetic Storms

The International Space Station (ISS) is a low Earth orbit research facility and host to an international crew. Geomagnetic storms cause changes in the Earth’s magnetic field and affect the ion density and temperature in the ionosphere which could pose a hazard to ISS crew. This hazard is measured by the Floating Potential Measurement Unit (FPMU) which measures ion density, ion temperature, and the charge differential of the ISS relative to its surrounding environment. I analyzed data collected by Narrow Sweep Langmuir Probe for two storms in 2015. Ion density and temperature were affected by geomagnetic storms, but the effects were less than those found due to normal orbital conditions

Developing reading-writing connections; the impact of explicit instruction of literary devices on the quality of children's narrative writing

The purpose of this collaborative schools-university study was to investigate how the explicit instruction of literary devices during designated literacy sessions could improve the quality of children's narrative writing. A guiding question for the study was: Can children's writing can be enhanced by teachers drawing attention to the literary devices used by professional writers or “mentor authors”? The study was conducted with 18 teachers, working as research partners in nine elementary schools over one school year. The research group explored ways of developing children as reflective authors, able to draft and redraft writing in response to peer and teacher feedback. Daily literacy sessions were complemented by weekly writing workshops where students engaged in authorial activity and experienced writers' perspectives and readers' demands (Harwayne, 1992; May, 2004). Methods for data collection included video recording of peer-peer and teacher-led group discussions and audio recording of teacher-child conferences. Samples of children's narrative writing were collected and a comparison was made between the quality of their independent writing at the beginning and end of the research period. The research group documented the importance of peer-peer and teacher-student discourse in the development of children's metalanguage and awareness of audience. The study suggests that reading, discussing, and evaluating mentor texts can have a positive impact on the quality of children's independent writing

Investigation into the Causes and Severity of the 1918 Influenza Pandemic

The 1918 Influenza outbreak is regarded as one of the worst pandemics in human history due to its widespread effects across the globe and its high death rate. This death rate was unusual among influenza infections as most strains do not cause the amount of death that is seen in this outbreak, with 20 million dead as a conservative estimate and 100 million by other estimations. This pandemic was not very well contained for a plethora of reasons. Two main reasons are that it came at a time when understanding viral mechanics still escaped medical professionals, and due to the ongoing war quarantine was not a measure imposed by many cities. To understand how this virus was able to so effectively wreak havoc in the human population, it must be shown how this virus was unique not just in spread, but also in its method of killing its host. These two traits must be looked at together as the virus was able to spread so quickly and this virus was able to kill not just those with a weak immune system, but in many cases those individuals who had the best immune system to fight the infection still died from the disease. The virus was able to be so effective at spreading and causing death, due to alterations to its genome which allowed both for an asymptomatic period of the infection where the PA gene was used as a less pathogenic version (PA-X) this allowed the virus to multiply to a point where it could easily overwhelm total body defense with number of viral particles. This asymptomatic period allowed the viral transmission to spread faster than people expected as the virus would be transmitted before an infected individual knew they were sick. This allowed for another unique trait of the virus to take over, the cytokine storm. This storm used the body’s own defenses to weaken it and paralyze the immune system in a way that allowed for a secondary infection to easily infect the host and cause death. This happened during this pandemic as many of those who died fell to a bacterial pneumonia infection and not the virus itself. These characteristics, combined with the virus’ timing allowed for it to be the worst pandemic that mankind had experienced. As the virus both exhibited novel traits, and came at a time when preventative measures were not in place and human migration was occurring due to the war

Instrument subjects are agents or causers

It has often been noticed that one syntactic argument position can be realized by elements which seem to realize different thematic roles. This is notably the case with the external argument position of verbs of change of state which licenses volitional agents, instruments or natural forces/causers, showing the generality and abstractness of the external argument relation. (1) a. John broke the window (Agent) b. The hammer broke the window (Instrument) c. The storm broke the window (Causer) In order to capture this generality, Van Valin & Wilkins (1996) and Ramchand (2003) among others have proposed that the thematic role of the external argument position is in fact underspecified. The relevant notion is that of an effector (in Van Valin & Wilkins) or of an abstract causer/initiator (in Ramchand). In this paper we argue against a total underspecification of the external argument relation. While we agree that (1b) does not instantiate an instrument theta role in subject position, we argue that a complete underspecification of the external theta-position is not feasible, but that two types of external theta roles have to be distinguished, Agents and Causers. Our arguments are based on languages where Agents and Causers show morpho-syntactic independence (section 2.1) and the behavior of instrument subjects in English, Dutch, German and Greek (section 2.2 and 3). We show that instrument subjects are either Agent or Causer like. In section (4) we give an analysis how arguments realizing these thematic notions are introduced into syntax

Historic Preservation Program newsletter

2017. UNIVERSITY OF VERMONT HISTORIC PRESERVATION PROGRAM HISTORY DEPARTMENT - WHEELER HOUSE - BURLINGTON, VERMONThttps://scholarworks.uvm.edu/hpnewsletter/1009/thumbnail.jp