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2002

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Full-Text Articles in Life Sciences

Effectiveness Of Delayed Brush Cutting And Herbicide Treatments For Vegetation Control In A Seven-Year-Old Jack Pine Plantation In Northwestern Ontario, Canada, Azim U. Mallik, F. Wayne Bell, Yanli Gong Dec 2002

Effectiveness Of Delayed Brush Cutting And Herbicide Treatments For Vegetation Control In A Seven-Year-Old Jack Pine Plantation In Northwestern Ontario, Canada, Azim U. Mallik, F. Wayne Bell, Yanli Gong

Aspen Bibliography

Efficacy of three conifer release treatments, i) single application of glyphosate (Vision™) herbicide, ii) multiple application of glyphosate herbicide, and iii) motor-manual brush cutting for controlling competing plants, particularly trembling aspen (Populus tremuloides), pin cherry (Prunus pensylvanica), green alder (Alnus viridis spp. crispa), and beaked hazel (Corylus cornuta spp. cornuta), was studied in a seven-year-old jack pine (Pinus banksiana) plantation in northwestern Ontario, Canada. The single and multiple glyphosate applications were equally effective in controlling trembling aspen and pin cherry, causing over 90% stem mortality. The brushsaw treatment caused an initial decrease followed by an increase in stem density of …


Shellfish Population And Bed Dimension Assessment In The Great Bay Estuary, Brian Smith Dec 2002

Shellfish Population And Bed Dimension Assessment In The Great Bay Estuary, Brian Smith

PREP Reports & Publications

This final report details a study funded by the NHEP over the course of 2001-02. The NHF&G Department was funded to delineate oyster bed size and density, monitor oyster disease, and examine the density of clam concentrations in the Great Bay Estuary.


Natural Fire Regime: A Guide For Sustainable Management Of The Canadian Boreal Forest, Yves Bergeron, Alain Leduc, Brian D. Harvey, Sylvie Gauthier Dec 2002

Natural Fire Regime: A Guide For Sustainable Management Of The Canadian Boreal Forest, Yves Bergeron, Alain Leduc, Brian D. Harvey, Sylvie Gauthier

Aspen Bibliography

The combination of certain features of fire disturbance, notably fire frequency, size and severity, may be used to characterize the disturbance regime in any region of the boreal forest. As some consequences of fire resemble the effects of industrial forest harvesting, conventional forest management is often considered as a disturbance that has effects similar to those of natural disturbances. Although the analogy between forest management and fire disturbance in boreal ecosystems has some merit, it is important to recognise that it also has its limitations. Short fire cycles generally described for boreal ecosystems do not appear to be universal; rather, …


Community Conservation Assistance, Frank Mitchell Dec 2002

Community Conservation Assistance, Frank Mitchell

PREP Reports & Publications

The Community Conservation Assistance Project had the following goal and objectives: Goal: Sustain and protect open space lands identified by communities and land trusts as critical to water quality and biodiversity through voluntary land conservation. Objectives: 1. With the SPNHF and other partners, establish a seacoast office for the Center for Land Conservation Assistance. 2. Provide education to various audiences in the seacoast region. 3. Create a library of relevant materials 4. Develop and compile publications 5. Establish with the SPNHF and other partners and participate in the first annual NH Land Conservation Conference 6. Evaluate program effectiveness 7. Coordinate …


Environmental Indicator Report: Water Quality, Phil Trowbridge Dec 2002

Environmental Indicator Report: Water Quality, Phil Trowbridge

PREP Reports & Publications

During the fall and winter of 2001-2002, the New Hampshire Estuaries Project’s Technical Advisory Committee (TAC) developed a suite of environmental indicators to track progress toward the NHEP’s management goals and objectives. These indicators were fully described in terms of their performance criteria, statistical methods, and measurable goals in the NHEP’s Monitoring Plan published in May 2002. The next step is to use these indicators to produce an updated “State of the Estuaries” report by the spring of 2003. The TAC decided to break this task into three sections: shellfish indicators in the fall of 2002; water quality indicators in …


Juvenile Clam Mortality Study At Three Intertidal Flats In Hampton Harbor, New Hampshire, Brian F. Beal Dec 2002

Juvenile Clam Mortality Study At Three Intertidal Flats In Hampton Harbor, New Hampshire, Brian F. Beal

PREP Reports & Publications

Soft-shell clams, Mya arenaria L., represent an important recreational fishery along the New Hampshire coast. Intertidal flats in the Hampton-Seabrook Estuary are among the most heavily harvested. As recently as the fall of 1998, the sandy flats in this area supported more than 900 clammers, who, on weekends, easily harvested their 9.5-liter limit (Varney, 1999). Recently, however, quantitative benthic surveys have suggested that the abundance of adult clams (> 50 mm shell length, SL) has dwindled on the three estuarine flats (Brown’s Flat, Common Island, and Middle Ground). Clammers support this contention and many have been disappointed at the relative …


Differential Lipid Biosynthesis Underlies A Tradeoff Between Reproduction And Fl Ight Capability In A Wing-Polymorphic Cricket, Zhangwu Zhao, Anthony J. Zera Dec 2002

Differential Lipid Biosynthesis Underlies A Tradeoff Between Reproduction And Fl Ight Capability In A Wing-Polymorphic Cricket, Zhangwu Zhao, Anthony J. Zera

Anthony Zera Publications

The biochemical basis of life-history tradeoffs is a poorly studied aspect of life-history evolution. We used radiotracer and endocrine approaches to investigate the extent to which morphs of a wing-polymorphic insect differ in the biosynthesis of lipid classes important for dispersal capability vs. reproduction (ovarian growth). The flightcapable genotype of Gryllus firmus biosynthesized a greater amount of total lipid and triglyceride (main flight fuel), which was preferentially allocated to somatic tissue during early adulthood. By contrast, the fl ightless genotype biosynthesized a significantly greater amount of phospholipid (important in egg development), which was preferentially allocated to ovaries. Topical application of …


Apple 1-Aminocyclopropane-1-Carboxylate Synthase In Complex With The Inhibitor L-Aminoethoxyvinylglycine: Evidence For A Ketimine Intermediate, Guido Capitani, Darla L. Mccarthy, Heinz Gut, Markus G. Grütter Dec 2002

Apple 1-Aminocyclopropane-1-Carboxylate Synthase In Complex With The Inhibitor L-Aminoethoxyvinylglycine: Evidence For A Ketimine Intermediate, Guido Capitani, Darla L. Mccarthy, Heinz Gut, Markus G. Grütter

University Faculty Publications and Creative Works

The 1.6-Å crystal structure of the covalent ketimine complex of apple 1-aminocyclopropane-1-carboxylate (ACC) synthase with the potent inhibitor L-aminoethoxyvinylglycine (AVG) is described. ACC synthase catalyzes the committed step in the biosynthesis of ethylene, a plant hormone that is responsible for the initiation of fruit ripening and for regulating many other developmental processes. AVG is widely used in plant physiology studies to inhibit the activity of ACC synthase. The structural assignment is supported by the fact that the complex absorbs maximally at 341 nm. These results are not in accord with the recently reported crystal structure of the tomato ACC synthase …


Estimation Of Relative Abundance Of Recreationally Important Juvenile Finfish In The Virginia Portion Of Chesapeake Bay Project Rfol-3 July 2001 - June 2002, Marcel M. Montaine, Herbert M. Austin, Patrick J. Geer, Wendy A. Lowery Dec 2002

Estimation Of Relative Abundance Of Recreationally Important Juvenile Finfish In The Virginia Portion Of Chesapeake Bay Project Rfol-3 July 2001 - June 2002, Marcel M. Montaine, Herbert M. Austin, Patrick J. Geer, Wendy A. Lowery

Reports

No abstract provided.


Estimating The Latitudinal Origins Of Migratory Birds Using Hydrogen And Sulfur Stable Isotopes In Feathers: Influence Of Marine Prey Base, Casey A. Lott, Timothy D. Meehan, Julie A. Heath Dec 2002

Estimating The Latitudinal Origins Of Migratory Birds Using Hydrogen And Sulfur Stable Isotopes In Feathers: Influence Of Marine Prey Base, Casey A. Lott, Timothy D. Meehan, Julie A. Heath

Julie Heath

Hydrogen stable isotope analysis of feathers is an important tool for estimating the natal or breeding latitudes of nearctic-neotropical migratory birds. This method is based on the latitudinal variation of hydrogen stable isotope ratios in precipitation in North America (iDp) and the inheritance of this variation in newly formed feathers (iDf). We hypothesized that the typically strong relationship between iDp and iDf would be decoupled in birds that forage in marine food webs because marine waters have relatively high iD values compared to iD values for local precipitation. Birds that forage on marine prey bases should also have feathers with …


Sea Surface Salinity Measurements In The Historical Database, Frederick M. Bingham, Stephan D. Howden, Chester J. Koblinsky Dec 2002

Sea Surface Salinity Measurements In The Historical Database, Frederick M. Bingham, Stephan D. Howden, Chester J. Koblinsky

Faculty Publications

We have examined historical distributions of sea surface salinity (SSS) observations in a data set consisting of a combination of the World Ocean Database 1998 (WOD98) and a thermosalinograph and bucket salinity database collected from volunteer observing ships. It is well known that SSS in much of the world's ocean is measured infrequently or not at all. We find that 27% of one-degree squares in the world ocean (open and coastal, excluding the Arctic Ocean) had no observations of SSS in the historical database, and 70% had 10 or fewer. Systematic sampling of SSS (more than 10,000 observations per year …


Surface And Deep Ocean Circulation In The Subpolar North Atlantic During The Mid-Pleistocene Revolution, Amy K. Wright, Benjamin P. Flower Dec 2002

Surface And Deep Ocean Circulation In The Subpolar North Atlantic During The Mid-Pleistocene Revolution, Amy K. Wright, Benjamin P. Flower

Marine Science Faculty Publications

We investigated surface and deep ocean variability in the subpolar North Atlantic from 1000 to 500 thousand years ago (ka) based on two Ocean Drilling Program (ODP) sites, Feni drift site 980 (55°29′N, 14°42′W) and Bjorn drift site 984 (61°25′N, 24°04′W). Benthic foraminiferal stable isotope data, planktic foraminiferal faunas, ice‐rafted debris data, and faunally based sea‐surface temperature estimates help test the hypothesis that oceanographic changes in the North Atlantic region were associated with the onset of the 100‐kyr world during the mid‐Pleistocene revolution. Based on percentage of Neogloboquadrina pachyderma (s) records from both sites, surface waters during interglacials and glacials …


Northeast Research Station Watertown, South Dakota Annual Progress Report, 2002, Agricultural Experiment Station, Plant Science Department Dec 2002

Northeast Research Station Watertown, South Dakota Annual Progress Report, 2002, Agricultural Experiment Station, Plant Science Department

Agricultural Experiment Station and Research Farm Annual Reports

This is the 2002 annual progress report for the Northeast Research Station in Watertown, South Dakota. This report is issued by the South Dakota Agricultural Experiment Station and the South Dakota State University Plant Science Department. This report includes weather data, yield comparisons, crop performance trials, corn trials, soybean trials, winter wheat performance testing, Barley Foliar information, weed and pest control, herbicide demonstrations, canola and flax variety trials and more.


Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden Dec 2002

Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden

Biochemistry and Microbiology

Morphological alterations have been shown to occur in Drosophila melanogaster when function of Hsp90 (heat shock 0-kDa protein 1α, encoded by Hsp83) is compromised during development1. Genetic selection maintains the altered phenotypes in subsequent generations1. Recent experiments have shown, however, that phenotypic variation still occurs in nearly isogenic recombinant inbred strains of Arabidopsis thaliana2. Using a sensitized isogenic D. melanogaster strain, iso-KrIf-1, we confirm this finding and present evidence supporting an epigenetic mechanism for Hsp90’s capacitor function, whereby reduced activity of Hsp90 induces a heritably altered chromatin state. The altered chromatin state is evidenced by ectopic expression …


Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 1999-2003 Annual Report, 1 September 2001 - 31 October 2002, Philip W. Sadler, Robert J. Latour, Robert E. Harris, Kristin L. Maki, John E. Olney Dec 2002

Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 1999-2003 Annual Report, 1 September 2001 - 31 October 2002, Philip W. Sadler, Robert J. Latour, Robert E. Harris, Kristin L. Maki, John E. Olney

Reports

This report presents the results of striped bass (Marone saxatilis) tagging and monitoring activities in Virginia during the penod 1 September 2001 through 31 October 2002. It includes an assessment of the biological characteristics of striped bass taken from the 2002 spring spawning run, estimates of annual survtval based on annual spring tagging, and the results of the fall 2001 directed mortality study that is cooperative with the Maryland Department of Natural Resources. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for striped bass …


Feline Immunodeficiency Virus Integration In B-Cell Lymphoma Identifies A Candidate Tumor Suppressor Gene On Human Chromosome 15q151, Julia Beatty, Anne Terry, Julie Macdonald, Elizabeth Gault, Stanley Cevario, Stephen J. O'Brien, Ewan Cameron, James C. Neil Dec 2002

Feline Immunodeficiency Virus Integration In B-Cell Lymphoma Identifies A Candidate Tumor Suppressor Gene On Human Chromosome 15q151, Julia Beatty, Anne Terry, Julie Macdonald, Elizabeth Gault, Stanley Cevario, Stephen J. O'Brien, Ewan Cameron, James C. Neil

Biology Faculty Articles

Infection with immunosuppressive lentiviruses is associated with increased cancer risk,but most studies have implicated indirect mechanisms as the tumor cells generally lack integrated viral sequences.An exception wasfound in a B-cell lymphoma (Q254) where the tumor cells contained a single integrated feline immunodeficiency virus genome. Additional analysis now indicates that feline immunodeficiency virus integration in lymphoma Q254 resulted in promoter insertion and truncation of a conserved gene on feline chromosome B3, whereas the unaffected allele of the gene appeared to be transcriptionally down-regulated. The orthologous human gene (FLJ12973), is expressed ubiquitously and encodes a WD-repeat protein with structural similarity …


West River Ag Center Crops And Soils Research Annual Progress Report, 2002, Agricultural Experiment Station Dec 2002

West River Ag Center Crops And Soils Research Annual Progress Report, 2002, Agricultural Experiment Station

Agricultural Experiment Station and Research Farm Annual Reports

This is the 2002 progress report of the West River Crops and Soils Research Projects, South Dakota Agricultural Experiment Station. This document includes reports on: weather and climate, wheat and grain variety trials, management and tillage, and weed and pest control.


Taxonomy And Distribution Of Butterflies (Papilionoidea) Of The Skardu Region, Pakistan, Muhammad Abbas, Muhammad Ather Rafi, Mian Inayatullah, Muhammad Rafique Khan, Harry Pavulaan Dec 2002

Taxonomy And Distribution Of Butterflies (Papilionoidea) Of The Skardu Region, Pakistan, Muhammad Abbas, Muhammad Ather Rafi, Mian Inayatullah, Muhammad Rafique Khan, Harry Pavulaan

The Taxonomic Report of the International Lepidoptera Survey

A study was conducted in six different localities around Skardu, Pakistan to document the butterfly fauna of that region. The study revealed that 16 species in 5 families and 14 genera occur in the area. The families include: Papilionidae (represented only by the genus Parnassius); Pieridae (genera Pieris, Pontia, and Colias are represented); Lycaenidae (genera Lycaena, Everes, Aricia, Plebejus, Zizeeria, and Zizina are represented); Nymphalidae (only two genera, Aglais and Cynthia are represented); and Satyridae (represented by the genera Pararge and Maniola).


The Effects Of Prescribed Fire On Millipede And Salamander Populations In A Southern Appalachian Deciduous Forest., Alison Baird Gagan Dec 2002

The Effects Of Prescribed Fire On Millipede And Salamander Populations In A Southern Appalachian Deciduous Forest., Alison Baird Gagan

Electronic Theses and Dissertations

Prescribed fire has increased as a forest management practice in southern Appalachia, but investigations into the effects of this silvicultural treatment on non-game wildlife inhabiting the region is limited. This study investigated the effects of prescribed fire on millipede and salamander populations. Seventeen sites within the Cherokee National Forest in east Tennessee that were treated once with prescribed fire between 1998 and 2002 were examined in the spring of 2002. Each burned plot was paired with an adjacent unburned plot.

The number of individual millipedes and salamanders collected from burned plots was compared to the corresponding control plot. Millipedes declined …


Breed Comparisons Of Angus, Charolais, Hereford, Jersey, Limousin, Simmental, And South Devon For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Breed Comparisons Of Angus, Charolais, Hereford, Jersey, Limousin, Simmental, And South Devon For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Breed means and differences for weight (CW, n = 19,851), height (CH, n = 14,553), and condition scores (CS, n = 19,536) recorded in four seasons per year were evaluated for 881 cows ranging from 2 to 7 yr of age from Cycle I of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. Cows were straightbred Herefords and Angus and top-crosses from mating of Hereford, Angus, South Devon, Jersey, Simmental, Limousin, and Charolais sires to Hereford and Angus dams. The model included cow age, season of measurement, and their interactions, with year of birth, pregnancy-lactation (PL) code, …


Comparisons Of Angus-, Braunvieh-, Chianina-, Hereford-, Gelbvieh-, Maine Anjou-, And Red Poll-Sired Cows For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Comparisons Of Angus-, Braunvieh-, Chianina-, Hereford-, Gelbvieh-, Maine Anjou-, And Red Poll-Sired Cows For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data from Angus, Hereford, and topcross cows (n = 641) from 2- to 8-yr-old daughters of seven breeds of sires included in Cycle II of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center, comprising cow weight (CW, n = 15,698), height (CH, n = 15,676), and condition score (CS, n = 15,667), were used to estimate breed-group differences. Data were recorded in four seasons of each year (1975 to 1982). The mixed model included cow age, season of measurement, and their interactions, year of birth, pregnancy-lactation code (PL), and breed-group as fixed effects for CW and CS. …


Estimates Of Genetic Parameters And Genetic Change For Reproduction, Weight, And Wool Characteristics Of Columbia Sheep, Kathryn J. Hanford, L. Dale Van Vleck, G. D. Snowder Dec 2002

Estimates Of Genetic Parameters And Genetic Change For Reproduction, Weight, And Wool Characteristics Of Columbia Sheep, Kathryn J. Hanford, L. Dale Van Vleck, G. D. Snowder

Department of Animal Science: Faculty Publications

Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and bivariate analyses were compared with respect to genetic trends. Number of observations were 31,401 for litter size at birth and litter size at weaning, 24,741 for birth weight, 23,903 for weaning weight, 29,572 for fleece weight and fleece grade, and 2,449 for staple …


Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck Dec 2002

Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Weight (CW, n = 61,798), weight adjusted for condition score (WA), hip height (CH, n = 56,494), and condition score (CS, n = 61,434) of cows (2 through 8 yr of age) produced by crosses of 22 sire breeds with Angus and Hereford dams in the first four cycles of the Germplasm Evaluation (GPE) Program at the U.S. Meat Animal Research Center were used to estimate genetic parameters with REML. The model included sire breed, dam breed, age in years, season of measurement (1 to 4) and their interactions, and year of birth and pregnancy-lactation code (PL) as fixed effects …


Epigenetic History Of An Arabidopsis Trans-Silencer Locus And A Test For Relay Of Trans-Silencing Activity, Huaxia Qin, Albrecht G. Von Arnim Dec 2002

Epigenetic History Of An Arabidopsis Trans-Silencer Locus And A Test For Relay Of Trans-Silencing Activity, Huaxia Qin, Albrecht G. Von Arnim

Plant Sciences Publications and Other Works

Background

Meiotically heritable epimutations affecting transgene expression are not well understood, even and in particular in the plant model species, Arabidopsis thaliana. The Arabidopsis trans-silencer locus, C73, which encodes a fusion protein between the repressor of photomorphogenesis, COP1, and green fluorescent protein (GFP-COP1), heritably modifies the expression pattern and cop1-like cosuppression phenotypes of multiple GFP-COP1 target loci by transcriptional gene silencing.

Results

Here we describe three additional features of trans-silencing by the C73 locus. First, the silencing phenotype of C73 and of similar complex loci was acquired epigenetically over the course of no more than two plant …


Breed Comparisons Of Angus, Brahman, Hereford, Pinzgauer, Sahiwal, And Tarentaise For Weight, Weight Adjusted For Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Breed Comparisons Of Angus, Brahman, Hereford, Pinzgauer, Sahiwal, And Tarentaise For Weight, Weight Adjusted For Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data from topcross cows (n = 468) from six breeds of sire (Angus, Brahman, Hereford, Pinzgauer, Sahiwal, Tarentaise) and two breeds of dam (Angus and Hereford) of Cycle III of the Germplasm Evaluation (GPE) program at the U.S. Meat Animal Research Center (MARC) comprising cow weight (CW, n = 9,012), height (CH, n = 9,010), and condition score (CS, n = 8,991) recorded in four seasons per year from 2 to 6 yr of age were used to estimate breed-group differences. The mixed models included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and …


Estimates Of Parameters Between Direct And Maternal Genetic Effects For Weaning Weight And Direct Genetic Effects For Carcass Traits In Crossbred Cattle, R. K. Splan, Larry V. Cundiff, M. E. Dikeman, L. Dale Van Vleck Dec 2002

Estimates Of Parameters Between Direct And Maternal Genetic Effects For Weaning Weight And Direct Genetic Effects For Carcass Traits In Crossbred Cattle, R. K. Splan, Larry V. Cundiff, M. E. Dikeman, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Estimates of heritabilities and genetic correlations were obtained for weaning weight records of 23,681 crossbred steers and heifers and carcass records from 4,094 crossbred steers using animal models. Carcass traits included hot carcass weight; retail product percentage; fat percentage; bone percentage; ribeye area; adjusted fat thickness; marbling score, Warner- Bratzler shear force and kidney, pelvic and heart fat percentage. Weaning weight was modeled with fixed effects of age of dam, sex, breed combination, and birth year, with calendar birth day as a covariate and random direct and maternal genetic and maternal permanent environmental effects. The models for carcass traits included …


What Makes An Animal Choose A Forage, Elizabeth A. Burritt, Frederick D. Provenza Dec 2002

What Makes An Animal Choose A Forage, Elizabeth A. Burritt, Frederick D. Provenza

Wildland Resources Faculty Publications

Consider the following scenarios: To cut the costs of ranching a researcher explores feeding cattle ammoniated straw in winter. Some of the cows maintain themselves on the diet while others lose weight, produce less milk and fail to conceive. A producer in Missouri plants a pasture rich in legumes and high in crude protein, yet his cattle prefer moldy hay and endophyte infected tall fescue to the legumes. Why do animals behave this way? Animals are thought to prefer foods that are palatable but what is palatability? We define palatability as the interrelationship between a food's flavor and postingestive feedback …


Biodiversity And Ecosystem Function: The Consumer Connection, J. Emmett Duffy Dec 2002

Biodiversity And Ecosystem Function: The Consumer Connection, J. Emmett Duffy

VIMS Articles

Proposed links between biodiversity and ecosystem processes have generated intense interest and controversy in recent years. With few exceptions, however, empirical studies have focused on grassland plants and laboratory aquatic microbial systems, whereas there has been little attention to how changing animal diversity may influence ecosystem processes. Meanwhile, a separate research tradition has demonstrated strong top‐down forcing in many systems, but has considered the role of diversity in these processes only tangentially. Integration of these research directions is necessary for more complete understanding in both areas. Several considerations suggest that changing diversity in multi‐level food webs can have important ecosystem …


The Insulation Of Genes From External Enhancers And Silencing Chromatin, Bonnie Burgess-Beusse, Catherine Farrell, Miklos Gaszner, Michael Litt, Vesco Mutskov, Felix Recillas - Targa, Melanie Simpson, Adam West, Gary Felsenfeld Dec 2002

The Insulation Of Genes From External Enhancers And Silencing Chromatin, Bonnie Burgess-Beusse, Catherine Farrell, Miklos Gaszner, Michael Litt, Vesco Mutskov, Felix Recillas - Targa, Melanie Simpson, Adam West, Gary Felsenfeld

Department of Biochemistry: Faculty Publications

Insulators are DNA sequence elements that can serve in some cases as barriers to protect a gene against the encroachment of adjacent inactive condensed chromatin. Some insulators also can act as blocking elements to protect against the activating influence of distal enhancers associated with other genes. Although most of the insulators identified so far derive from Drosophila, they also are found in vertebrates. An insulator at the 5′ end of the chicken β -globin locus marks a boundary between an open chromatin domain and a region of constitutively condensed chromatin. Detailed analysis of this element shows that it possesses …


Electricity Production By Geobacter Sulfurreducens Attached To Electrodes, Daniel R. Bond, Derek Lovley Dec 2002

Electricity Production By Geobacter Sulfurreducens Attached To Electrodes, Daniel R. Bond, Derek Lovley

Derek Lovley

Previous studies have suggested that members of the Geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. In order to better understand this electron transfer process for energy production, Geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate or hydrogen was the electron donor. The electron-accepting electrodes were maintained at oxidizing potentials by connecting them to similar electrodes in oxygenated medium (fuel cells) or to potentiostats that poised electrodes at +0.2 V versus an Ag/AgCl reference electrode (poised potential). When a small inoculum of G. sulfurreducens was introduced into …