A multiple-plan evaluation model for small ungauged watersheds

A computer solution model is proposed for simulation of the effect of alternative measures for flood damage reduction. The goal of the model is to optimize the value of an objective function which will maximize the amount of net benefits returned by the project. The evaluation includes unit hydrograph synthesis, direct runoff construction, computation of average annual damages, and optimization of an objective function. A test application of the model is made on a small community affected by floods from a small ungauged stream --Abstract, page iii

Students\u27 Attitudes Towards Statistics in Medical Research: A Comparison of Four Health Sciences Programs

Driven by a market that is imposing greater scrutiny on health care providers as well as by an explosive increase in health-related research, there is a growing need for an improved understanding of statistical design and analysis among today\u27s students and practitioners in the health sciences. Although most students in the health sciences are required to take an introductory statistics course prior to entering professional programs, little is known about the attitudes those students possess regarding the use of statistics in medical research

Strategies to improve stored forage use efficiency

Two experiments evaluated collection frequency impacts on forage waste estimates and bale diam., stocking rate, and feeder design influences on waste level. In Exp. 1, waste collection daily (DLY) reduced (P < 0.05) estimates 18% compared to collection at bale replacement (CUML). As waste amount increased, there was greater difference in proportion of waste that was clean between DLY and CUML estimates. Greater (P < 0.05) CP and Ash concentration in CUML waste than initial bale suggest increased contamination because DLY bale and waste were not different. Increased SEM for CUML waste estimates resulted in different inferences being made compared to DLY. Daily waste collection is optimal to reduce waste contamination and estimate variation. Also in Exp. 1, cone presence reduced hay waste 17%, when the same base feeder design was used. In Exp. 2, the same cone feeder was used and reduced waste 30% compared to an open ring feeder with no upper or lower section sheeting. Feeder sheeting was comparable to cone for waste reduction. In Exp. 1, bales that were 129 cm in diam. decreased (P < 0.05) waste compared to bale with diam. 158 cm or greater. The small bale diam. reduced waste by increasing feeding space or decreasing time to consume bale. Increased stocking rate decreased time to consume a bale, but did not change waste in Exp. 2. Waste was not influenced by time to consume bale in Exp. 2, so decreased waste in Exp. 1 was due to increased feeding space

Oyster Spatfall in Virginia Rivers: 1982 Annual Summary

The Virginia Institute of Marine Science (VIMS) conducts weekly surveys from June through early October to obtain oyster spatfall information. Spat counts are made from oyster shells strung on wire and suspended from stakes on public and private beds. The number of spat on shells are counted each week of the spawning season to determine the potential of a particular area for receiving a strike and to predict the most likely period the strikes will occur

An investigation, testing and modifying of gear to harvest oysters and shell : final contract report for the period 1 July, 1973 through 30 June, 1975

During the 1974-75 contract period the hydraulic escalator was modified and tested in the York and Rappahannock Rive r s . The tests showed that the harvester was capable of raising large quantities of oysters from various types of bottoms. Moreover, these oysters were not broken or crushed, were free .of silt or grit , and t he apparatus caused only minima l damage to the bottom . The modification were made from January to April and field testing began in May 1975 in t he York and Rappahannock Rivers on public and leased bottom and on several types of substrate . The device was demonstrated for oyster growers , television companies, the press, representatives of the Virginia Marine Resources Commission, the Maryland Department of Tidewater Fisheries and a representative of the National Marine Fisheries Service. A total of 16 trials or demonstrations were completed which are listed in detail chronologically i n the appendix

The origin and extent of oyster reefs in the James River, Virginia

The public oyster grounds (Baylor Survey Grounds) in the James River, VA, were studied with respect to bottom type and oyster density from 1978 to 1981. Approximately 10,118 ha (25,000 acres) were investigated using an electronic positioning system to establish station locations. Bottom types were determined using probing pipes, patent tongs, and an acoustical device. About 17.1% of the bottom was classified as consolidated oyster reef, and 47.5% was moderately productive mud-shell or sand-shell bottoms. The remaining 35.4% was rated as unsuitable for oyster culture. The surface configuration of oyster reef areas in the James River is similar to those in coastal lagoons· along the Gulf of Mexico. They are thought to have developed in the James River as they did in the Gulf of Mexico area as sea level rose during the Holocene Period

The physiography and extent of public oyster grounds in Pocomoke Sound, Virginia.

Public oyster grounds in Pocomoke Sound, Virginia, were charted in 1978 using an electronic positioning system to locate areas ~f oysters, shell, sand or mud. Over five thousand stations were occupied and 1,267 samples of the substrate were taken with hydraulically operated patent tongs. The information was used to draw large scale charts showing shorelines, depths, bottom types and out lines of public grounds. Substrates, elevations, slopes, oyster densities and spatfall levels were analyzed

Treatment of shell with Polystream to increase survival of oysters (Crassostrea virginica) in Virginia

Survival of oysters set on shells treated with Polystream* was investigated during 1963 and 1964. Treated and control shells were held in wire bags in the high-salinity intertidal seaside area of the Eastern Shore and in the moderate-salinity subtidal areas of the lower James River. Significantly more spat survived on treated shells than on controls. Differences in survival could not be attributed to absence of drill predation on treated shell