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Physical Sciences and Mathematics

1992

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Articles 181 - 203 of 203

Full-Text Articles in Life Sciences

Soil And Water Conservation Provisions Of The 1990 Food, Agriculture, Conservation And Trade Act, Monroe Rasnake, Bob Eddleman, Tommy Howard Jan 1992

Soil And Water Conservation Provisions Of The 1990 Food, Agriculture, Conservation And Trade Act, Monroe Rasnake, Bob Eddleman, Tommy Howard

Agriculture and Natural Resources Publications

Soil conservation is not new in Kentucky. Most farmers are aware of the need to protect soil and have used practices such as crop rotation, residue management, contour tillage, sod waterways, and no-till for many years. However, soil erosion is of neverending concern and still remains a problem in many areas.


Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran Jan 1992

Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran

Journal of the Arkansas Academy of Science

The Ouachita National Forest (ONF) has developed a series of Best Management Practices (BMP's) designed to protect water quality and associated beneficial uses (fisheries, municipal water supplies, etc.). A monitoring program is necessary to document the effectiveness of that protection. The Basin Area Stream Survey (BASS) methodology provides a monitoring link from BMP's to the aquatic ecosystems. The goal of BASS is to identify the physical, chemical and biological characteristics of a stream in a format that will allow comparisons with other streams, and indicate when a stream is being impacted. Six index streams within two ecoregions were selected and …


Fodder Trees And Shrubs For High Rainfall Areas Of South Western Australia, Daya Patabendige, P R. Scott, Edward C. Lefroy Jan 1992

Fodder Trees And Shrubs For High Rainfall Areas Of South Western Australia, Daya Patabendige, P R. Scott, Edward C. Lefroy

Resource management technical reports

In south Western Australia, the lack of good quality feed in late summer and autumn is a major constraint to livestock production. This feed gap is usually filled by costly supplementary hand feeding of grain or hay. The ability of some trees and shrubs to provide good quality forage during summer and autumn has generated interest for many years (Corbett, 1951; Everist, 1969; Snook, 1987;Oldham et al., 1991, Lefroy, 1991). The dual benefits of reducing the need for supplementary hand feeding and deferring the grazing of annual pastures until they are well established has recently led to the recognition of …


Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock Jan 1992

Distribution, Abundance, And Behavior Of The Cownose Ray, Rhinoptera Bonasus (Mitchill 1815), In Lower Chesapeake Bay, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

Aspects of the ecology of the cownose ray, Rhinoptera bonasus, in the lower Chesapeake Bay and its tributaries were studied using aerial surveys, biotelemetry, and examination of stomach contents. The Chesapeake Bay was surveyed by airplane during 1986-1989, to examine the distribution of cownose rays and estimate their abundance using line transect methods. Cownose rays resided in Chesapeake Bay throughout the summer months, entering in early June and emigrating in late September. They were usually absent, or nearly so, by late October. Mean monthly abundance ranged from none present in May and November, to a September average of 9.3 &\cdot& …


Taxonomy Of Larval Blennioidei Of Belize, Central America, Martin Ray Cavalluzzi Jan 1992

Taxonomy Of Larval Blennioidei Of Belize, Central America, Martin Ray Cavalluzzi

Dissertations, Theses, and Masters Projects

No abstract provided.


Role Of Habitat Features And Chemical Cues In Substrate Selection By Blue Crab Megalopae: Evidence From Laboratory Experiments, Bruce Clare Layman Jan 1992

Role Of Habitat Features And Chemical Cues In Substrate Selection By Blue Crab Megalopae: Evidence From Laboratory Experiments, Bruce Clare Layman

Dissertations, Theses, and Masters Projects

No abstract provided.


Measurement Of The Carbon And Nitrogen Densities Of The Marine Heterotrophic Flagellate Paraphysomonas Sp, Yongsik Sin Jan 1992

Measurement Of The Carbon And Nitrogen Densities Of The Marine Heterotrophic Flagellate Paraphysomonas Sp, Yongsik Sin

Dissertations, Theses, and Masters Projects

No abstract provided.


Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti Jan 1992

Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti

Biological Sciences Faculty Publications

The seasonal and inter-annual concentrations of phytoplankton were studied over a 50 month period in the lower James, York and Rappahannock Rivers (USA). Differences in the onset, duration and magnitude of major seasonal growth periods varied from year to year. There was a tendency for spring, summer and fall maxima, with a winter period of reduced abundance. An additional study of picoplankton over a 12 month period indicated greatest abundance during summer and fall, with least development in winter.


The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin Jan 1992

The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin

Masters Theses

Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.

In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the effects …


Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr Jan 1992

Survival Of Juvenile Queen Conch, Strombus Gigas, In Natural Habitats: Impact Of Prey, Predator And Habitat Features, Livingston Sinclair Marshall Jr

Dissertations, Theses, and Masters Projects

In this dissertation, I experimentally examine predation-induced mortality upon juvenile queen conch, Strombus gigas, and assess the importance of select habitat predator and conch characteristics affecting predation intensity. Experiments were conducted during the summer and early fall of 1987, 1988, 1990 and 1991 in seagrass beds and adjacent sand flats near Lee Stocking Island, Exuma Cays, Bahamas. These experiments indicate that various factors act interactively to produce habitat-specific mortality rates in queen conch due to predation. These include (1) habitat type, whereby seagrass beds offer some protection; (2) local population dynamics, such that populated seagrass beds appear to enhance conch …


Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo Jan 1992

Modelling Of Zinc Accumulation In The American Oyster, Crassostrea Virginica (Gmelin), Cheol Mo

Dissertations, Theses, and Masters Projects

A model of zinc accumulation by the American oyster, Crassostrea virginica, is developed by relating in-situ zinc body burden to time-integration of uptake. Short-term uptake rates are estimated in laboratory by introducing &\sp{lcub}65{rcub}&Zn to oysters of various weights in aquaria with salinities of 18&\perthous& and 12&\perthous&. Uptake of &\sp{lcub}65{rcub}&Zn by an oyster: (1) varies as a power function of the body weight (soft tissue dry weight) of the oyster (&dy\over{lcub}dt{rcub}& = kW&\sp{lcub}\beta{rcub}&), (2) is inversely related to the salinity of ambient water, and (3) increases linearly with ambient concentration. Zinc body burdens of oysters of various weights from oyster beds …


The Role Of Trees In Sustainable Agriculture : A National Conference : Reprints Of Western Australian Papers, P R. Scott Jan 1992

The Role Of Trees In Sustainable Agriculture : A National Conference : Reprints Of Western Australian Papers, P R. Scott

Resource management technical reports

  • The role of trees in land and stream salinity control in Western Australia (Conference paper: N.J. Schofield, M.A. Ban, D.T. Bell, W.J. Boddington, R.J. George, N.E. Pettit)
  • The role of trees in providing shelter and controlling erosion in the dry temperate and semi-arid southern agricultural areas of Western Australia (Conference paper: D. Bicknell)
  • Management of native woody vegetation on farms in Western Australia (Conference paper: J.P. Pigott)
  • Producing timber from trees - options for farmers in Western Australia (Conference paper: R. Moore)
  • Trees and shrubs as sources of fodder in Western Australia (Conference paper: E.C. Lefroy)
  • Minor forest products in …


Floristic Survey Of Remnant Vegetation In The Bindoon To Moora Area, Western Australia, Edward Arnold Griffin Jan 1992

Floristic Survey Of Remnant Vegetation In The Bindoon To Moora Area, Western Australia, Edward Arnold Griffin

Resource management technical reports

No abstract provided.


Soils And Landforms Of The Manjimup Area, Western Australia, Hugh Maxwell Churchward Jan 1992

Soils And Landforms Of The Manjimup Area, Western Australia, Hugh Maxwell Churchward

Land resources series

No abstract provided.


Soils Of The Northam Advisory District. Volume 2. The Zone Of Rejuvenated Drainage, Neil Clifton Lantzke Jan 1992

Soils Of The Northam Advisory District. Volume 2. The Zone Of Rejuvenated Drainage, Neil Clifton Lantzke

Bulletins 4000 -

This manual describes the soils of the Department of Agriculture's Northam advisory district. Information is provided on the characteristics of each soil, its capability is discussed and yield estimates for the major land uses are given.

Designed for use by farmers and Department of Agriculture staff, the manual’s primary aims are to:

- Assist with the identification of the advisory district’s soils types

- Match land use with soil quality

- Improve farm productivity and efficiency

- Reduce the incidence of land degradation


Soils Of The Northam Advisory District. Volume 1. The Zone Of Ancient Drainage, Neil Clifton Lantzke Jan 1992

Soils Of The Northam Advisory District. Volume 1. The Zone Of Ancient Drainage, Neil Clifton Lantzke

Bulletins 4000 -

This manual describes the soils of the Department of Agriculture's Northam advisory district. Information is provided on the characteristics of each soil, its capability is discussed and yield estimates for the major land uses are given.

Designed for use by farmers and Department of Agriculture staff, the manual’s primary aims are to:

- Assist with the identification of the advisory district’s soils types

- Match land use with soil quality

- Improve farm productivity and efficiency

- Reduce the incidence of land degradation



An Introduction To The Soils Of The Merredin Advisory District, T C. Stoneman, National Soil Conservation Program (Australia) Jan 1992

An Introduction To The Soils Of The Merredin Advisory District, T C. Stoneman, National Soil Conservation Program (Australia)

Bulletins 4000 -

With descriptions, illustrations and notes on nine common soils.


The Role Of Earthworms In Western Australian Agriculture, Tom Mccredie, Lex Parker Jan 1992

The Role Of Earthworms In Western Australian Agriculture, Tom Mccredie, Lex Parker

Journal of the Department of Agriculture, Western Australia, Series 4

Earthworms have a reputation as soil builders and renovators, particularly among 'organic' farmers and gardeners. They improve soil fertility through increased aeration, aggregation, water infiltration and release of nutrients from organic matter. However, the benefits of earthworms in the wheatbelt have been doubted for many years because of their poor survival in cultivated soils.

Since cropping began in the Western Auslmlian whealbelt over 1OO years ago, the physical condition of many soils has deteriorated. The primary causes of soil degradation were the European cultivation practices used by farmers and the trampling effect of introduced animals. in particular, sheep.


Taking The Emu To Market, Paul Frapple, Ruth Hagan Jan 1992

Taking The Emu To Market, Paul Frapple, Ruth Hagan

Journal of the Department of Agriculture, Western Australia, Series 4

Licensed, commercial emu farming in Western Australia is now five years old.

This year, 13,500 birds will be processed for their meat, skin and oil. Production has exceeded demand at prices which the industry considers fair because the industry is still developing marketd for these producys.

Without secure, long term markets, over-production will worsen as the turn-off in this State increases and emus become available from other Australian states and overseas.

The Department of Agriculture is assisting the industry to develop a viable industry.


How Arsenic Residues Get In Wool, Tony Martin, Robin Jacob, Marion Davies, Peter Rutherford Jan 1992

How Arsenic Residues Get In Wool, Tony Martin, Robin Jacob, Marion Davies, Peter Rutherford

Journal of the Department of Agriculture, Western Australia, Series 4

Wool can become contaminated with arsenic in various ways, and several different sources may each contribute to any individual arsenic residue problem.

• dipping sheep in an arsenical dip ( now illegal),

• dipping sheep in a non-arsenical dip in a contaminated dipping facility

• penning sheep on soil with high levels of arsenic before shearing.

Other possible sources include running sheep on land contaminated by gold mine tailings or exploration sites, and allowing sheep access to sites on the farm where arsenical compounds have been dumped, for example, rubbish dumps or sites where dip/sump sludge has been dumped.

Farmers …


Distribution Of Foraminifera And Pollen In Coastal Depositional Environments Of The Southern Delmarva Peninsula, Virginia, U.S.A., Han Jun Woo Jan 1992

Distribution Of Foraminifera And Pollen In Coastal Depositional Environments Of The Southern Delmarva Peninsula, Virginia, U.S.A., Han Jun Woo

OES Theses and Dissertations

The coastal zone of the southern Delmarva Peninsula exhibits a wide variety of barrier island system subenvironments. This study investigates whether 20 a priori subenvironments can be distinguished from each other on the basis of abiotic environmental variables, pollen assemblages, living foraminiferal populations, and total (living plus dead) foraminiferal assemblages.

The physical data collected from the coastal zone were subjected to canonical variate analysis which discriminated 83% of the stations in 19 groups. These groups were clustered into two internally overlapping sets which represented the inside and outside of the inlet.

Twenty-two pollen types were found in low-energy marsh and …


Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter Jan 1992

Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter

OES Theses and Dissertations

The eggs of the Japanese medaka (Oryzias latipes) were employed in a number of studies to develop a routine, standardized assay which can assess the acute and sublethal impacts of individual toxicants and complex mixtures. The eggs of this Cyprinodont minnow were topically treated with each toxicant or mixture dissolved in membrane permeable dimethylsulfoxide (DMSO) solvent. Nine chemicals were initially evaluated with two, pentachlorophenol (PCP) and tributyltin chloride (TBTCl), subsequently selected for extensive evaluations of salinity tolerance and the accuracy of the topical exposure method for representing a typical immersion exposure. The amount of material actually penetrating the eggs was …


A Capacity Theory Of Comprehension: Individual Differences In Working Memory, Marcel Just, Patricia Carpenter Dec 1991

A Capacity Theory Of Comprehension: Individual Differences In Working Memory, Marcel Just, Patricia Carpenter

Marcel Adam Just

No abstract provided.