EXPERIMENTS ON VIDEO STREAMING OVER COMPUTER NETWORKS

Video traffic (including streaming video service) is dominating the Internet traffic today. Video can be streamed using a dedicated server, a content delivery network (CDN), or peer-to-peer (P2P) overlays across a network. Video can be transmitted in multiple formats and at different resolutions. Video is also being distributed to a variety of devices (fixed and mobile)

EXPERIMENTS ON VIDEO STREAMING OVER COMPUTER NETWORKS

Video traffic (including streaming video service) is dominating the Internet traffic today. Video can be streamed using a dedicated server, a content delivery network (CDN), or peer-to-peer (P2P) overlays across a network. Video can be transmitted in multiple formats and at different resolutions. Video is also being distributed to a variety of devices (fixed and mobile)

Determining the Nature of Late Gunn-Peterson Troughs with Galaxy Surveys

Recent observations have discovered long (up to ~110 Mpc/h), opaque Gunn-Peterson troughs in the z ~ 5.5 Lyman-alpha forest, which are challenging to explain with conventional models of the post-reionization intergalactic medium. Here we demonstrate that observations of the galaxy populations in the vicinity of the deepest troughs can distinguish two competing models for these features: deep voids where the ionizing background is weak due to fluctuations in the mean free path of ionizing photons would show a deficit of galaxies, while residual temperature variations from extended, inhomogeneous reionization would show an overdensity of galaxies. We use large (~550 Mpc/h) semi-numerical simulations of these competing explanations to predict the galaxy populations in the largest of the known troughs at z ~ 5.7. We quantify the strong correlation of Lyman-alpha effective optical depth and galaxy surface density in both models and estimate the degree to which realistic surveys can measure such a correlation. While a spectroscopic galaxy survey is ideal, we also show that a relatively inexpensive narrowband survey of Lyman-alpha-emitting galaxies is ~90% likely to distinguish between the competing models.Comment: 12 pages, 16 figures. Submitted to Ap

Exploiting drought tolerance traits and genetic diversity of synthetic hexaploid wheat in winter wheat breeding

2014 Summer.As the world's most widely dispersed food crop, wheat (Triticum spp.) is produced on approximately 22% of currently cultivated land. This wide distribution of environments and the large demand for consumption requires the adaptability of wheat to various environmental stresses. Therefore, this study was conducted to assess the benefits of introgressing synthetic hexaploid wheat (SHW) diversity into winter wheat in the U.S. Great Plains. The objectives of this study were to: 1) identify differences in drought tolerance-related physiological and morphological trait expression among SHW lines and adapted winter wheat cultivars; 2) evaluate and select SHW-derived backcross lines from multi-environment field studies for potential use as breeding germplasm; and 3) locate genomic regions of synthetic origin that show promise for yield improvements through targeted introgression into elite bread wheat backgrounds. The instability of crop yields is predicted to increase due to climate change and environmental stresses, with drought considered the abiotic stress that is most associated with a loss of yield in cereal crops. The improvement of yield and drought stress tolerance in bread wheat (Triticum aestivum L.) through the introgression of novel alleles from ancestral species may be feasible. Synthetic hexaploid wheat, which incorporates the AABB genome from Durum wheat and the DD genome from the progenitor Aegilops tauschii, has shown promise for improving bread wheat yield and agronomic performance. In this study a group of six SHW lines were selected from a collection of 412 lines developed by the International Maize and Wheat Improvement Center (CIMMYT, El Batan, Mexico). A subset of SHW lines was selected after two years of testing for visual agronomic traits and yield in Colorado. The six SHW lines were analyzed in greenhouse conditions for differences in drought tolerance traits relative to four adapted cultivars. This experiment focused on root morphology traits of these genotypes grown in one meter tall plastic tubes. Some synthetic lines ranked better than the adapted check varieties under greenhouse conditions for drought tolerance traits such as deep root biomass, longest root, and stomatal density. The plasticity of total root biomass and root biomass in the deepest third of the tubes was also found to be significantly correlated (P<0.05, r = 0.72 and 0.70, respectively) with a calculated drought index. Digital analysis of root length in five root diameter classes indicated a significant (P<0.05) increase of small diameter root growth under drought stress for drought tolerant genotypes compared to drought sensitive genotypes. The development and testing of 10 SHW-derived BC1F1:2 populations (15 lines per population), with 'Hatcher' and 'Goodstreak' as the recurrent parents, identified six out of twelve SHW populations that showed the highest overall yield in eight Colorado and Nebraska environments in 2009-2010 and 2010-2011. Single plant selections were made from the highest yielding SHW-derived lines within each selected population and planted as headrows in 2011-2012. The top 10% of the headrows was selected based on visual assessment of yield potential and agronomic attributes such as early maturity date and lodging and disease resistance. Advanced yield testing of the selected fraction was then conducted in 2012-2013. Synthetic-derived lines with Hatcher as a recurrent parent showed a wide variety of yield under both irrigated and rainfed conditions in the summer of 2013. Two SHW-derived lines outranked Hatcher for grain yield in all three environments in 2013 with two additional lines ranking higher than all adapted check cultivars in both irrigated and rainfed environments. Of several agronomic traits evaluated, harvest index and canopy temperature showed the highest correlations with grain yield under drought (r = 0.55 and -0.53, respectively, P<0.05). Canopy temperature was also assessed every other hour (0900 to 1730 h) for a single day during the grain fill period. This analysis identified high yielding SHW-derived lines showing contrasting responses (both continuous and variable period of low canopy temperature) relative to Hatcher under drought. Genotyping-by-sequencing data for the SHW-derived lines identified 13 single nucleotide polymorphisms which showed a preferential selection for the allele of synthetic origin after three selection events for improved grain yield. Our results demonstrate improvements in yield and agronomic performance in SHW-derived lines. Therefore we conclude that the use of SHW has good potential for introgression of diversity into elite winter bread wheat in the U.S. Great Plains

Using the USDA wind erosion equation for comparative modeling of natural and anthropogenic sources of particulates measured at the Fort Greely PM₁₀ monitoring station, Alaska, a case study

Master's Project (M.S.) University of Alaska Fairbanks, 2015In April of 2010, the Alaska Department of Environmental Conservation (ADEC) opened a compliance case against the U.S. Army Garrison Fort Greely, Alaska (FGA), for then repeated failure to comply with a permit condition requiring the collection of one year of Prevention of Significant Deterioration (PSD)-quality data on ambient levels of particulate matter less than 10 microns in effective aerodynamic diameter (PM₁₀). During the monitoring period of 2012-2013, background levels of PM₁₀ were more than 80% the Alaska Ambient Air Quality Standards (AAAQS) for a total of seven days in the winter of 2012-2013. On March 17, 2014, ADEC requested that FGA provide substantive documentation that PM₁₀ exceedances observed during the monitoring period were of natural provenance and not from anthropogenic sources. In response to this request, the author used Geographic Information System (GIS) technology to analyze basic meteorological data and outputs from the USDA Wind Erosion Equation (WEQ) to generate a simple back-trajectory model for determining the sources and relative contributions to PM₁₀ experienced at a given receptor. Using this model, the author was able to show that the vast majority of PM₁₀ at Fort Greely was natural rather than anthropogenic in nature. The ADEC Division of Air Quality determined that results of this study constituted substantive documentation that PM₁₀ exceedances observed during the monitoring period were of natural provenance and not from anthropogenic sources, and issued a compliance case closure letter on June 20, 2014. In addition to the direct results of the study, the project also serves to demonstrate a low-complexity model that can be used to assess the relative contribution of anthropogenic and natural sources of PM₁₀ at a given receptor. Additionally, it can be used in complex situations as a screening tool to focus data collection efforts on significant sources of PM₁₀ and facilitate the prioritization of PM₁₀ sources for more precise quantitative dispersion or receptor models when precise quantitative data are required

Human trafficking, homicide and current prevention efforts in The United States of America

The article focuses primarily on the question of why human trafficking is often overlooked as a contributing factor in homicide cases. As a case study, the author analyzes one of the most infamous serial murder cases in United States history, the John Wayne Gacy case, in which the human trafficking element remained hidden for almost 40 years. The case is examined from five different perspectives: (1) the prosecution; (2) the defense; (3) the police; (4) the culture; and (5) political corruption. In addition, the piece provides an overview of current efforts in the United States to prevent trafficking in persons, including a summary of the Trafficking Victims Protection Act, the annual Trafficking in Persons Report, with its informative regional and country narratives, and the White House’s National Action Plan to Combat Human Trafficking