Status of MSX in Chesapeake Bay

Oystermen in lower Chesapeake Bay survived the ravages of Dermocystidium during some hot summers in the past decade only to be scourged by a new disease which appeared in 1969. We had learned to live with Dermocystidium by avoiding infected seed and limiting the number of hot summers oysters were held in infested areas. Now we have the more difficult problem of adjusting to MSX which is a devastating killer of oysters

Status of diseases of oysters in Chesapeake Bay

Oysters in lower Chesapeake Bay survived the ravages of Dermocystidium during some hot summers in the past decade only to be scourged by a new disease (MSX) which appeared in 1959. We had learned to live with Dermocystidium by avoiding infected seed and limiting the number of hot summers oysters were held in infested areas. Now we are faced with the more difficult problem of adjusting to MSX, which is a devastating killer of oysters. The beginning of a new season of planting seed is an appropriate time to review our knowledge of teh various diseases of oysters

Space biology initiative program definition review. Trade study 2: Prototype utilization in the development of space biology hardware

The objective was to define the factors which space flight hardware developers and planners should consider when determining: (1) the number of hardware units required to support program; (2) design level of the units; and (3) most efficient means of utilization of the units. The analysis considered technology risk, maintainability, reliability, and safety design requirements for achieving the delivery of highest quality flight hardware. Relative cost impacts of the utilization of prototyping were identified. The development of Space Biology Initiative research hardware will involve intertwined hardware/software activities. Experience has shown that software development can be an expensive portion of a system design program. While software prototyping could imply the development of a significantly different end item, an operational system prototype must be considered to be a combination of software and hardware. Hundreds of factors were identified that could be considered in determining the quantity and types of prototypes that should be constructed. In developing the decision models, these factors were combined and reduced by approximately ten-to-one in order to develop a manageable structure based on the major determining factors. The Baseline SBI hardware list of Appendix D was examined and reviewed in detail; however, from the facts available it was impossible to identify the exact types and quantities of prototypes required for each of these items. Although the factors that must be considered could be enumerated for each of these pieces of equipment, the exact status and state of development of the equipment is variable and uncertain at this time

New Developments at NASA's Instrument Synthesis and Analysis Laboratory

NASA's Instrument Synthesis and Analysis Laboratory (ISAL) has developed new methods to provide an instrument study in one week's engineering time. The final product is recorded in oral presentations, models and the analyses which underlie the models

Synthetic Applications and Methodological Developments of Donor-Acceptor Cyclopropanes and Related Compounds

Donor-acceptor cyclopropanes are convenient precursors to reactive and versatile 1,3-dipoles, and have found application in the synthesis of a variety of carbo- and heterocyclic scaffolds. This perspective review details our laboratory’s use of donor-acceptor cyclopropanes as intermediates toward the total synthesis of various natural products. We also discuss our work in the development of novel cycloadditions and rearrangements of donor-acceptor cyclopropanes and aziridines, as well as an example of an aryne insertion proceeding via fragmentation of a transient donor-acceptor cyclobutane

Oyster Mortality Studies in Virginia: Ill. Epizootiology of a Disease Caused by Haplosporidium costale Wood and Andrews

A short, sharp eplzootic disease of oysters on Seaside of Eastern Shore, Virginia, has been associated with a new pathogen, Haplosporidium costale Wood and Andrews. Native oysters in trays have shown closely timed May-June losses for three consecutive years. Losses at other seasons were small. May-June losses ranged from 12 to 14 percent in 1959 to 36 to 44 percent in 1960. James River oysters moved to Seaside showed higher losses than natives after a year of acclimation. Oysters in Bayside creeks revealed late summer losses caused by Dermocystidimn marinmn Mackin, Owens, and Collier rather than May-June deaths. The new pathogen was found in live oysters from March to July, and in a high proportion of gapers in May and June. The epizootiology is well established for these periods but unknown for the rest of the year. Increasing prevalence of another pathogen ( MSX ), causing Delaware Bay disease, has complicated mortality studies. Losses are most serious in older oysters which have been held beyond the usual period of culture. Careful timing of planting and early harvesting permit oystermen to a void serious losses

Sea Grant Annual Report 1972

A Report on the Virginia Institute of Marine Science Sea Grant Program for January I -December 31, 197

The relationship of readiness factors to Jan. first grade reading achievement

Thesis (Ed.M.)--Boston Universit

An Investigation of the Relationship Between Grades and Learning Modes in an Introductory Research Methods Course

Education researchers have conducted studies on the relationship of learning mode to student performance, but few studies have evaluated pass rate, grade distribution and student withdrawal rate in an introductory research methods course. In this study, researchers examined 2,097 student grades from the 2015-2016 academic year to determine if such a relationship existed. In this study, learning mode was significantly related to failure rate, grade distribution and withdraw rate. Synchronous video home students had a significantly higher failure rate than traditional In-Person or online students. Online student grade distributions were significantly different than In-Person classroom, synchronous video home or synchronous video classroom students. Online Students tended to earn more A s and fewer B s and D s. Synchronous video home students also had a significantly higher withdraw rate than synchronous video classroom students. Recommendations for further research include investigating variables which may impact student performance such as faculty experience with course content and technology and how students select learning modes when taking classes. Future research should continue to employ outcome-based studies to measure the impact of learning mode on student performance. This remains a key issue from the perspective of the students and the institution