Phase Transitions in a Dusty Plasma with Two Distinct Particle Sizes

In semiconductor manufacturing, contamination due to particulates significantly decreases the yield and quality of device fabrication, therefore increasing the cost of production. Dust particle clouds can be found in almost all plasma processing environments including both plasma etching devices and in plasma deposition processes. Dust particles suspended within such plasmas will acquire an electric charge from collisions with free electrons in the plasma. If the ratio of inter-particle potential energy to the average kinetic energy is sufficient, the particles will form either a liquid structure with short range ordering or a crystalline structure with long range ordering. Otherwise, the dust particle system will remain in a gaseous state. Many experiments have been conducted over the past decade on such colloidal plasmas to discover the character of the systems formed, but more work is needed to fully understand these structures. The preponderance of previous experiments used monodisperse spheres to form complex plasma systems

Yeast vaccine vector including immunostimulatory and antigenic polypeptides and methods of using the same

Vaccine compositions including a yeast comprising an immunostimulatory polypeptide and optionally an antigenic polypeptide are provided herein. The immunostimulatory polypeptide and the antigenic polypeptide are expressed or displayed on the surface of the yeast vaccine composition. Methods of using the vaccine composition to vaccinate subjects are also provided

Compositions and Methods of Enhancing Immune Responses to Eimeria or Limiting Eimeria Infection

Vaccine vectors and methods of using the vaccine vectors to enhance the immune response to an Apicomplexan parasite and reduce the morbidity or morality associated with subsequent infection are provided herein. The vaccine vectors include a polynucleotide encoding a Rhomboid polypeptide and optionally include an immune-stimulatory polypeptide suitably expressed on the surface of the vaccine vector

Compositions and methods of enhancing immune responses to Eimeria or limiting Eimeria infection

Vaccine vectors and methods of using the vaccine vectors to enhance the immune response to an Apicomplexan parasite and reduce the morbidity or mortality associated with subsequent infection are provided herein. The vaccine vectors include a polynucleotide encoding a Rhomboid polypeptide and optionally include an immune-stimulatory polypeptide suitably expressed on the surface of the vaccine vector

Dusty Plasma Correlation Function Experiment

Dust particles immersed within a plasma environment, such as those in protostellar clouds, planetary rings or cometary environments, will acquire an electric charge. If the ratio of the inter-particle potential energy to the average kinetic energy is high enough the particles will form either a "liquid" structure with short-range ordering or a crystalline structure with long range ordering. Many experiments have been conducted over the past several years on such colloidal plasmas to discover the nature of the crystals formed, but more work is needed to fully understand these complex colloidal systems. Most previous experiments have employed monodisperse spheres to form Coulomb crystals. However, in nature (as well as in most plasma processing environments) the distribution of particle sizes is more randomized and disperse. This paper reports experiments which were carried out in a GEC rf reference cell modified for use as a dusty plasma system, using varying sizes of particles to determine the manner in which the correlation function depends upon the overall dust grain size distribution. (The correlation function determines the overall crystalline structure of the lattice.) Two dimensional plasma crystals were formed of assorted glass spheres with specific size distributions in an argon plasma. Using various optical techniques, the pair correlation function was determined and compared to those calculated numerically.Comment: 6 pages, Presented at COSPAR '0

Competitive exclusion of Salmonella enteritidis by Salmonella gallinarum in poultry.

Salmonella Enteritidis emerged as a major egg-associated pathogen in the late 20th century. Epidemiologic data from England, Wales, and the United States indicate that S. Enteritidis filled the ecologic niche vacated by eradication of S. Gallinarum from poultry, leading to an epidemic increase in human infections. We tested this hypothesis by retrospective analysis of epidemiologic surveys in Germany and demonstrated that the number of human S. Enteritidis cases is inversely related to the prevalence of S. Gallinarum in poultry. Mathematical models combining epidemiology with population biology suggest that S. Gallinarum competitively excluded S. Enteritidis from poultry flocks early in the 20th century

Evaluating off-site disposal of low-level waste at LANL-9498

Los Alamos National Laboratory generates a wide range of waste types, including solid low-level radioactive waste (LL W), in conducting its national security mission and other science and technology activities. Although most ofLANL's LLW has been disposed on-site, limitations on expansion, stakeholder concerns, and the potential for significant volumes from environmental remediation and decontamination and demolition (D&D) have led LANL to evaluate the feasibility of increasing off-site disposal. It appears that most of the LL W generated at LANL would meet the Waste Acceptance Criteria at the Nevada Test Site or the available commercial LL W disposal site. Some waste is considered to be problematic to transport to off-site disposal even though it could meet the off-site Waste Acceptance Criteria. Cost estimates for off-site disposal are being evaluated for comparison to estimated costs under the current plans for continued on-site disposal

A Comprehensive Archival Search for Counterparts to Ultra-Compact High Velocity Clouds: Five Local Volume Dwarf Galaxies

We report five Local Volume dwarf galaxies (two of which are presented here for the first time) uncovered during a comprehensive archival search for optical counterparts to ultra-compact high velocity clouds (UCHVCs). The UCHVC population of HI clouds are thought to be candidate gas-rich, low mass halos at the edge of the Local Group and beyond, but no comprehensive search for stellar counterparts to these systems has been presented. Careful visual inspection of all publicly available optical and ultraviolet imaging at the position of the UCHVCs revealed six blue, diffuse counterparts with a morphology consistent with a faint dwarf galaxy beyond the Local Group. Optical spectroscopy of all six candidate dwarf counterparts show that five have an H$\alpha$-derived velocity consistent with the coincident HI cloud, confirming their association, the sixth diffuse counterpart is likely a background object. The size and luminosity of the UCHVC dwarfs is consistent with other known Local Volume dwarf irregular galaxies. The gas fraction ($M_{HI}/M_{star}$) of the five dwarfs are generally consistent with that of dwarf irregular galaxies in the Local Volume, although ALFALFA-Dw1 (associated with ALFALFA UCHVC HVC274.68+74.70$-$123) has a very high $M_{HI}/M_{star}$$\sim$40. Despite the heterogenous nature of our search, we demonstrate that the current dwarf companions to UCHVCs are at the edge of detectability due to their low surface brightness, and that deeper searches are likely to find more stellar systems. If more sensitive searches do not reveal further stellar counterparts to UCHVCs, then the dearth of such systems around the Local Group may be in conflict with $\Lambda$CDM simulations.Comment: 18 pages, 4 tables, 4 figures, ApJ Accepte