Life Sciences Commons^™

Acetate Oxidation Coupled To Fe(Iii) Reduction In Hyperthermophilic Microorganisms, Jason M. Tor, Kazem Kashefi, Derek Lovley

Derek Lovley

No hyperthermophilic microorganisms have previously been shown to anaerobically oxidize acetate, the key extracellular intermediate in the anaerobic oxidation of organic matter. Here we report that two hyperthermophiles, Ferroglobus placidus and “Geoglobus ahangari,” grow at 85°C by oxidizing acetate to carbon dioxide, with Fe(III) serving as the electron acceptor. These results demonstrate that acetate could potentially be metabolized within the hot microbial ecosystems in which hyperthermophiles predominate, rather than diffusing to cooler environments prior to degradation as has been previously proposed.

Extension Workers As Orchestrators Of Civic Renewal Through Civic Professionalism, Nancy K. Franz

Nancy K. Franz

I have a passion and a bias. I am passionate about the important role of the Cooperative Extension System (CES) in civic renewal. My bias is that extension workers (also known as agents or educators) are the key to civic renewal throughout the United States. No other institution has the same ability to reach all of America with education and organizing efforts. With extension workers in every county in the nation, this group of professionals and their work cut across age, race, ethnicity, religion, geography and many other demographic characteristics. Extension has a long history of being active in civic …

A Review Of Shellfish Restoration As A Tool For Coastal Water Quality Management., Michael A. Rice

Michael A Rice

In many areas, coastal residents and others oppose establishment of bivalve molluscan aquaculture projects on the basis of perceived negative environmental impacts. Often overlooked are positive environmental impacts of shellfish aquaculture that can potentially mitigate the impacts of other anthropogenic activities. Filter feeding by populations of bivalve mollusks is reviewed with respect to their ability to act as an estuarine filter, increase clarity of coastal waters and facilitate the removal of nitrogen and other nutrients from eutrophic coastal waters. Most species of cultured bivalve mollusks clear particles from waters at rates of 1 to 4 L/h, and populations of shellfish …

Development Of Real-Time Pcr Assays For Rapid Detection Of Pfiesteria Piscicida And Related Dinoflagellates, Torstein Tengs

Dr. Torstein Tengs

Pfiesteria complex species are heterotrophic and mixotrophic dinoflagellates that have been recognized as harmful algal bloom species associated with adverse fish and human health effects along the East Coast of North America, particularly in its largest (Chesapeake Bay in Maryland) and second largest (Albermarle- Pamlico Sound in North Carolina) estuaries. In response to impacts on human health and the economy, monitoring programs to detect the organism have been implemented in affected areas. However, until recently, specific identification of the two toxic species known thus far, Pfiesteria piscicida and P. shumwayae (sp. nov.), required scanning electron microscopy (SEM). SEM is a …

Issues In Quantifying Variability From A Dynamical Systems Perspective, Joseph Hamill, William J. Mcdermott, Jeffrey M. Haddad

Joseph Hamill

Variability is a critical aspect of a dynamical systems analysis. Because there are a number of numerical techniques that can be used in such an analysis, the calculation of variability has several issues that must be addressed. The purpose of this paper is to present a variety of quantitative methods for investigating variability from a dynamical systems perspective. The paper is divided into two major sections covering discrete and continuous methods. Each of these sections is subdivided into two sections. Within discrete methods, we discuss, first, the calculation of the discrete relative phase from a time-series history of two parameters …

Mother Of Seed, Sarah Kimakwa

Sarah Kimakwa

No abstract provided.

Yponomeuta Evonymellus Outbreaks In Southern Finland: Spatial Synchrony But Different Local Magnitudes, Brian J. Wilsey, Conchita Alonso, Timo Vuorisalo, Tuija Honkanen

Brian J. Wilsey

Defoliations of Prunus padus by Yponomeuta evonymellus were monitored in two areas in southern Finland. During a long-term study (1980–1995) in the area with high peak defoliations, P. padus trees recorded two defoliation peaks, leading to complete defoliation of many trees. The negative relationship between pupal mass and current year tree defoliation during the peak years suggested shortage of food affected reproductive potential of Y. evonymellus. Furthermore, no delayed induced resistance was observed in these populations. Interannual correlations in degrees of defoliation experienced by individual trees were low, i.e. high defoliation in one year did not predict the degree of …

Relationship Of Molecular Structure To The Mechanism Of Lysophospholipid-Induced Smooth Muscle Cell Proliferation, Yuh-Cherng Chai, David Binion, Guy Chisholm

Yuh-Cherng Chai

No abstract provided.

Effects Of Willows (Salix Brachycarpa) On Populations Of Salicylate-Mineralizing Microorganisms In Alpine Soils, Steven K. Schmidt, David A. Lipson, Ted K. Raab

Ted K. Raab

We used the substrate-induced growth-response (SIGR) method to quantify salicylate-mineralizing microbes and total microbial biomass in soils from under willows (Salix brachycarpa) and in surrounding meadows dominated by the sedge Kobresia myosuroides. Willows had a strong effect on the biomass of salicylate-mineralizing microbes in both years of this study. There were always higher biomass levels of salicylate mineralizers in soils from under Salix (4.6–10.1 ug C/ g) than under Kobresia (0.23–0.76 ug/ g). In contrast, total microbial biomass was not significantly different under these plant species in 1996 and was only higher under Salix on one date in 1997. These …

Avhrr Estimates Of Surface Temperature During The Southern Great Plains 1997 Experiment, Amy L. Kaleita, Praveen Kumar

Amy L. Kaleita

In this study we aim to (1) explore the differences in the accuracy of satellitederived land-surface skin temperature for day and nighttime observations, (2) assess the effects of large solar zenith angles, and (3) develop an understanding of the spatial variability of the observed temperatures. Land-surface skin temperatures are obtained using the split-window technique from observations of the AVHRR instrument aboard the NOAA-12 and NOAA-14 satellites for the SGP97 (Southern Great Plains 1997) hydrology experiment. From the study of several days of observations we find that observed biases with respect to the ground temperature, both during day and night, are …

Control Of Developmental Timing In Caenorhabditis Elegans, Victor Ambros

Victor R. Ambros

Studies of the nematode Caenorhabditis elegans have identified genetic and molecular mechanisms controlling temporal patterns of developmental events. Mutations in genes of the C. elegans heterochronic pathway cause altered temporal patterns of larval development, in which cells at certain larval stages execute cell division patterns or differentiation programs normally specific for other stages. The products of the heterochronic genes include transcriptional and translational regulators and two different cases of novel small translational regulatory RNAs. Other genes of the pathway encode evolutionarily conserved proteins, including a homolog of the Drosophila Period circadian timing regulator, and a member of the nuclear receptor …

Pest Risk Assessment For Importation Of Solid Wood Packing Materials Into The United States, Judith E. Pasek, Harold H. Burdsall Jr, Joseph F. Cavey, Andris Eglitis, Robert A. Haack, Dennis A. Haugen, Michael I. Haverty, Charles S. Hodges, Daniel R. Kucera, John D. Lattin, William J. Mattson, David J. Nowak, Joseph G. O'Brien, Richard L. Orr, Ronaldo A. Sequeira, Eugene B. Smalley, Borys M. Tkaxz, William E. Wallner

Judith E Pasek

A wide variety of exotic tree pests can readily be transported into the United States on untreated wooden pallets, crating, bracing, and other solid wood packing materials (SWPM). Recent introductions of forest pests associated with importation of SWPM demonstrate that current United States import regulations are inadequate to exclude such pests. Nearly all (97 percent) of the quarantine-significant tree pests found by port inspectors are associated with SWPM. In spite of current bark-free import requirements, about 9 percent of maritime shipments contain bark, which provides habitat for numerous organisms. A pest risk assessment was conducted for the SWPM pathway to …

Eight Ways To Be A Colonizer; Two Ways To Be An Invader., Mark Davis, K Thompson

Mark Davis

No abstract provided.

Precise, Highly Female-Biased Sex Ratios In A Social Spider, Leticia Avilés, John Mccormack, Asher Cutter, Todd Bukowski

John E. McCormack

It has been recognized for some time that the risk of producing maleless clutches should select for a lower than binomial variance in the sex ratio of organisms with female–biased sex ratios, small clutches and breeding groups containing the clutch of a single female. However, to date, precise sex ratios have only been reported for organisms with haplodiploid sex determination, a system which allows direct control of the sex of individual offspring. In contrast, under heterogametic sex determination chance is expected to play a crucial role in determining the sex composition of any one family, in particular when males are …

Die Mechanik "Weicher" Pflanzlicher Gewebe [The Mechanics Of 'Soft' Plant Tissues], Winfried S. Peters

Winfried S. Peters

An Outline Of A Theory Of The Constructional Constraints Governing Early Organismic Evolution, Winfried S. Peters, Bernd Herkner

Winfried S. Peters

This paper has no abstract; this is the first paragraph. The origin of life is one of the most fascinating biological enigmas (Dyson 1985, de Duve 1991). A multitude of hypotheses is available, ranging from the classical "primordial broth" (Haldane 1929) to the "genetic takeover" (Cairns-Smith 1982). Most of these models center on biochemical, metabolic, or genetic aspects. To our knowledge a comprehensive investigation into the mechanical constraints governing the early development of organismic constructions is not available to date. Attempting to close this gap, we here present an outline of a theory of the transformation of constructions in early …

Regulation Of Cell Growth By Oxidized Ldl., Guy Chisolm, Yuh-Cherng Chai

Yuh-Cherng Chai

The first reports of the influences of oxidized LDL (oxLDL) on cell function pertained to negative effects on cell growth—growth arrest, injury, and toxicity. Since these studies, it has become apparent that sublethal levels of oxLDL cause some, but not all, cells to proliferate. This review highlights the growth-promoting effects of oxLDL rather than its inhibitory or injurious effects. Smooth muscle cells (SMCs) and monocyte-macrophages proliferate after exposure to oxLDL; endothelial cells do not. Scavenger receptors are involved in the proliferative effects on monocyte-macrophages, whereas the effects of oxLDL on SMCs appear to be receptor independent. Lysophosphatidylcholine (lysoPC), and structurally …

Direct And Fe(Ii) Mediated Reduction Of Technetium By Fe(Iii)-Reducing Bacteria, Jon R. Lloyd, V. A. Sole, Catherine V. Van Praagh, Derek Lovley

Derek Lovley

The dissimilatory Fe(III)-reducing bacterium Geobacter sulfurreducens reduced and precipitated Tc(VII) by two mechanisms. Washed cell suspensions coupled the oxidation of hydrogen to enzymatic reduction of Tc(VII) to Tc(IV), leading to the precipitation of TcO(2) at the periphery of the cell. An indirect, Fe(II)-mediated mechanism was also identified. Acetate, although not utilized efficiently as an electron donor for direct cell-mediated reduction of technetium, supported the reduction of Fe(III), and the Fe(II) formed was able to transfer electrons abiotically to Tc(VII). Tc(VII) reduction was comparatively inefficient via this indirect mechanism when soluble Fe(III) citrate was supplied to the cultures but was enhanced …

Phylogenetic Resolution Within The Tribe Episcieae (Gesneriaceae): Congruence Of Its And Ndhf Sequences From Parsimony And Maximum-Likelihood Analyses, James F. Smith

James F. Smith

Generic relationships within Episcieae were assessed using ITS and ndhF sequences. Previous analyses of this tribe have focused only on ndhF data and have excluded two genera, Rhoogeton and Oerstedina, which are included in this analysis. Data were analyzed using both parsimony and maximum-likelihood methods. Results from partition homogeneity tests imply that the two data sets are significantly incongruent, but when Rhoogeton is removed from the analysis, the data sets are not significantly different. The combined data sets reveal greater strength of relationships within the tribe with the exception of the position of Rhoogeton. Poorly or unresolved relationships based exclusively …

Microteaching And The Art Of Lecturing, Don Morrow

Donald Morrow

No abstract provided.

Nike’S Commercial Solution: Girls, Sneakers, And Salvation, Shelley Lucas

Shelley Lucas

In this article I critically examine the ways in which Nike has situated itself as an active participant in current cultural conversations about girls' and women's participation in sport through three television commercials: `If you let me play', `There's a girl being born in America', and `The Fun Police'. In these advertisements, Nike positions itself as helping girls get a chance to play sports, helping them lead healthier and happier lives, helping them learn the rules of the game, and helping them to have fun. However, I argue that Nike's suggestion that girls can be empowered through sport (and through …

The Mechanic State Of “Inner Tissue” In The Growing Zone Of Sunflower Hypocotyls And The Regulation Of Its Growth Rate Following Excision, Winfried Peters, A. Tomos

Winfried S. Peters

Reaching And Teaching: Personality Preferences And Pedagogical Performance, Don Morrow

Donald Morrow

No abstract provided.

A Review Of Shellfish Restoration And Management Projects In Rhode Island, Michael A. Rice, April Valliere, Angela Caporelli

Michael A Rice

Shellfish management and restoration efforts in Rhode Island date back to the 19th century. From the late 1890s to the Second World War the Rhode Island Fisheries Commission operated a lobster hatchery in Wickford Harbor in response to a perceived decline in lobster catches in Narragansett Bay. Berried lobsters were collected, eggs hatched, larvae reared, and postlarval fifth stage juveniles were released into the bay. The project was discontinued primarily because of costs and a failure to demonstrate the efficacy of juvenile seeding in improving lobster catches. From the 1930s to the 1980s, there have been several similar efforts to …

Phylogenetic Analyses Indicate That The 19'Hexanoyloxy-Fucoxanthin-Containing Dinoflagellates Have Tertiary Plastids Of Haptophyte Origin, Torstein Tengs

Dr. Torstein Tengs

The three anomalously pigmented dinoflagellates Gymnodinium galatheanum, Gyrodinium aureolum, and Gymnodinium breve have plastids possessing 199-hexanoyloxy-fucoxanthin as the major carotenoid rather than peridinin, which is characteristic of the majority of the dinoflagellates. Analyses of SSU rDNA from the plastid and the nuclear genome of these dinoflagellate species indicate that they have acquired their plastids via endosymbiosis of a haptophyte. The dinoflagellate plastid sequences appear to have undergone rapid sequence evolution, and there is considerable divergence between the three species. However, distance, parsimony, and maximum-likelihood phylogenetic analyses of plastid SSU rRNA gene sequences place the three species within the haptophyte clade. …

Effects Of Synchrony With Host Plant On Population Of A Spring-Feeding Lepidopteran, Joseph Elkinton, A. F. Hunter

Joseph Elkinton

Comparisons of traits of outbreaking and nonoutbreaking leaf-eating Lepidoptera and Symphyta have shown that spring-feeding species are more likely to have outbreaks than are summer-feeding species. It has been suggested that variable synchrony with host budburst causes the population sizes of spring-feeding species to be more variable primarily because of the negative effects of older leaves on insects. While much evidence exists that leaf age can directly affect survival and reproduction of insects, few studies have looked at the population-level effects of variable phenology, and especially the potential for complex direct and indirect interactions with natural-enemy effects. To examine the …

Lack Of Production Of Electron-Shuttling Compounds Or Solubilization Of Fe(Iii) During Reduction Of Insoluble Fe(Iii) Oxide Of Geobacter Metallireducens, Derek Lovley, Kelly P. Nevin

Kelly Nevin

Studies with the dissimilatory Fe(III)-reducing microorganism Geobacter metallireducens demonstrated that the common technique of separating Fe(III)-reducing microorganisms and Fe(III) oxides with semipermeable membranes in order to determine whether the Fe(III) reducers release electron-shuttling compounds and/or Fe(III) chelators is invalid. This raised doubts about the mechanisms for Fe(III) oxide reduction by this organism. However, several experimental approaches indicated that G. metallireducens does not release electron-shuttling compounds and does not significantly solubilize Fe(III) during Fe(III) oxide reduction. These results suggest that G. metallireducens directly reduces insoluble Fe(III) oxide.

The Promoter Of The Yeast Ino4 Regulatory Gene:A Model Of The Simplest Yeast Promoter, John Lopes, Kelly A. Robinson

John Lopes

In Saccharomyces cerevisiae, the phospholipid biosynthetic genes are transcriptionally regulated in response to inositol and choline. This regulation requires the transcriptional activator proteins Ino4p and Ino2p, which form a heterodimer that binds to the UASINO element. We have previously shown that the promoters of the INO4 and INO2 genes are among the weakest promoters characterized in yeast. Because little is known about the promoters of weakly expressed yeast genes, we report here the analysis of the constitutive INO4 promoter. Promoter deletion constructs scanning 1,000 bp upstream of theINO4 gene identified a small region (−58 to −46) that is absolutely required …

Researching And Teaching Sport History: An Analysis, Don Morrow

Donald Morrow

No abstract provided.

Elimination Of Sequestered Material From The Gills Of Decapod Crustaceans., Gary Martin, Michael Quintero, Michael Quigley, Hovhannes Khosrovian

Gary Martin

Ink particles injected into the hemolymph of the American lobster (Homarus americanus), spiny lobster (Panulirus interruptus), crayfish (Procambarus clarkii), and ridgeback prawn (Sicyonia ingentis) were rapidly removed from circulation, and most were sequestered within nodules in the gills. The morphology of the gills and the nodules were examined from the time of injection until the following molt. The process by which ink was cleared from the gills was the same in all four species. Nodules formed within 10 min after injection and were composed of hemocytes loosely attached to one another and binding small quantities of ink. Within one week, …