Growth and Feeding Studies on the Algal Feeding Stage of a Pfiesteria-like Dinoflagellate

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 105 mL-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were highest with a cryptophyte, Cryptomonas, as food, but growth was also demonstrated utilizing both diatoms and chlorophytes. Cryptoperidiniopsis sp. is similar to Pfiesteria in that it feeds myzocytotically with a peduncle, is similar in size and shape, has a complex life cycle, and is distinguished only by plates hidden under membranes

Dinoflagellate Cysts Within Sediment Collections From the Southern Chesapeake Bay, and Tidal Regions of the James, York, and Rappahannock Rivers, Virginia

The upper 2 cm of sediment core samples from 70 stations in the tidal waters of three Virginia rivers and at 23 stations in the lower Chesapeake Bay were sampled for dinoflagellate cysts. The river sediment cysts were dominated by three common bloom producing species (Heterocapsa triquetra, Scrippsiella trochoidea, and Cochlodinium polykrikoides), whereas these were in low concentration on the Chesapeake Bay sediments which contained mainly dinoflagellate cysts of neritic and oceanic taxa. The mean sediment concentrations from stations in the James, York, and Rappahannock rivers were respectively 1174.8, 536.2, and 323.6 cysts g-1. The mean cyst concentration in the Chesapeake Bay sediment was 714. 8 g-1. Cysts of 2 potentially harmful species were recorded from the sediment, with the river sediments identified as seed beds and a source for re-occurring algal blooms in these waters

Growth and Feeding Studies on the Algal Feeding Stage of a Pfiesteria-like Dinoflagellate

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 105 mL-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were highest with a cryptophyte, Cryptomonas, as food, but growth was also demonstrated utilizing both diatoms and chlorophytes. Cryptoperidiniopsis sp. is similar to Pfiesteria in that it feeds myzocytotically with a peduncle, is similar in size and shape, has a complex life cycle, and is distinguished only by plates hidden under membranes

Monitoring Results for Pfiesteria piscidida and Pfiesteria-like Organisms from Virginia Waters in 1998

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also present throughout the water column at stations in the lower Chesapeake Bay, being most abundant in waters above the pycnocline

Monitoring Results for Pfiesteria piscidida and Pfiesteria-like Organisms from Virginia Waters in 1998

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also present throughout the water column at stations in the lower Chesapeake Bay, being most abundant in waters above the pycnocline

Hydrogen atom in a spherical well: linear approximation

We discuss the boundary effects on a quantum system by examining the problem of a hydrogen atom in a spherical well. By using an approximation method which is linear in energy we calculate the boundary corrections to the ground-state energy and wave function. We obtain the asymptotic dependence of the ground-state energy on the radius of the well.Comment: Revised version to appear in European Journal of Physic

Financial factors and institutional characteristics that explain undergraduate enrollment by low-income students at public master's-level institutions

Low-income students continue to struggle with the rising costs of higher education. Four-year college tuition typically exceeds financial aid awarded to undergraduates at public institutions. St. John (2005) contended that grant amounts remain inadequate for low-income students. Tinto (2008) highlighted the growing income stratification within higher education, particularly at four-year institutions. This research study focused on institution-level variables in an attempt to characterize the way that particular financial and institutional elements impact low-income undergraduate enrollment at public master's-level institutions. A thorough review of literature was conducted on college choice, costs and benefits of higher education, the problem of affordability, effects of financial aid, characteristics of low-income students, and enrollment rates by race, gender, and income level. This study expanded upon previous literature, which explored the relationship between college costs, financial aid, and higher education opportunities for diverse groups. This study involved a secondary analysis of data from five sources: 1) the National Center for Education Statistics (NCES) Integrated Postsecondary Education Data System (IPEDS), 2) the Delta Cost Project, 3) The College Board's 2009 Annual Survey of Colleges, 4) the U.S. Census Bureau categorization of four geographic regions of the United States, and 5) the unpublished dissertation, "A Geographical Classification of Master's Colleges and Universities," by Dr. Clint Kinkead. In order to explore the ways that financial factors and institutional characteristics differed across public master's-level institutions in the U.S., based upon geographic region, 2005 Carnegie Basic Classification, and campus setting, this data was analyzed first using descriptive statistics. Then, multiple linear regression analysis was conducted in order to determine which combination of factors was statistically significant in explaining low-income undergraduate enrollment at public master's-level institutions. Smaller, urban institutions were most effective at enrolling low-income undergraduate students in the 2007-2008 academic year. Institutions located in the West and South enrolled the highest number and greatest percentage, respectively, of low-income undergraduate students. The findings, conclusions, and recommendations of this study may provide useful guidance to higher education policymakers and practitioners concerning the development of policies and practices that better meet the needs of low-income undergraduate students seeking to enroll in public master's-level institutions. (Published By University of Alabama Libraries