Reproducibility of Biovolumetric Parameters in Community Reconstruction

Author Institution: Department of Geological Sciences, Wright State UniversityCriticisms have been raised about the inadequacies of methods in community paleoecological analysis. Until recently, most paleoecological studies were done by specialists in individual taxonomic groups. Because of this specialization, most data collected favored certain groups. Other fossils were either ignored, discounted, or loosely labelled qualitatively under descriptive terms as: rare, occasional or abundantly present. Ausich (1981) and Boucot (1981) have independently proposed methods of community analysis whereby the biovolume (shelly biomass) of all taxa present are quantified. To date, little has been done to substantiate the reproducibility of data obtained in this manner for level, soft-bottom, Paleozoic communities. A level, soft-bottom, Middle Devonian community is analyzed here using the sampling model proposed by Ausich (1981). Trends in the comparisons of biovolume to minimum number counts are shown to be reproducible as are trends in each of these catagories within individual horizontally continuous beds. Informational loss and quantitative reproducibility for this new method is shown to be an improvement over prior methodology

Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state

An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energy barrier. The PMFs were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We observe that the free energy barrier is reduced when the P/L ratio increased. In addition, we study the cooperative effect; specifically we investigate if the barrier is smaller for a second melittin reorientation, given that another neighboring melittin was already in the transmembrane state. We observe that indeed the barrier of the PMF curve is reduced in this case, thus confirming the presence of a cooperative effect

Delayed Appearance of High Altitude Retinal Hemorrhages

When closely examined, a very large amount of climbers exhibit retinal hemorrhages during exposure to high altitudes. The incidence of retinal hemorrhages may be greater than previously appreciated as a definite time lag was observed between highest altitude reached and development of retinal bleeding. Retinal hemorrhages should not be considered warning signs of impending severe altitude illness due to their delayed appearance

A Guide to Community Shared Solar: Utility, Private, and Non-Profit Project Development (Book)

This guide is organized around three sponsorship models: utility-sponsored projects, projects sponsored by special purpose entities - businesses formed for the purpose of producing community solar power, and non-profit sponsored projects. The guide addresses issues common to all project models, as well as issues unique to each model

A Guide to Community Shared Solar: Utility, Private, and Non-Profit Project Development (Book)

This guide is organized around three sponsorship models: utility-sponsored projects, projects sponsored by special purpose entities - businesses formed for the purpose of producing community solar power, and non-profit sponsored projects. The guide addresses issues common to all project models, as well as issues unique to each model

Glen or Glenda: Reported Gender of Sex Partners in Two Statewide HIV Databases

Objectives. We assessed agreement of reported gender of sex partners in 2 statewide HIV databases linked by client identifiers