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Full-Text Articles in Biology
An Unusual Pulse In Recruitment Of Two Reef Fishes In The Galápagos Islands Coincident With The 1997–1998 El Niño, Benjamin I. Ruttenberg
An Unusual Pulse In Recruitment Of Two Reef Fishes In The Galápagos Islands Coincident With The 1997–1998 El Niño, Benjamin I. Ruttenberg
Biological Sciences
No abstract provided.
Molecular Aspect Of Leaf Senescence, Edward Himelblau, Betania Quirino, Yoo-Sun Noh, Richard Amasino
Molecular Aspect Of Leaf Senescence, Edward Himelblau, Betania Quirino, Yoo-Sun Noh, Richard Amasino
Biological Sciences
Senescence is the last stage of leaf development and one type of programmed cell death that occurs in plants. The relationships among senescence programs that are induced by a variety of factors have been addressed at a molecular level in recent studies. Furthermore, an overlap between the pathogen-response and senescence programs is beginning to be characterized. The complexity of the senescence program is also evident in studies of senescence-specific gene regulation and the role of photosynthesis and plant hormones in senescence regulation. New molecular-genetic approaches are expected to be useful in unraveling the molecular mechanisms of the leaf senescence program.
Sequence Analysis Of Bacterial Dna In The Colon And Stomach Of The Tyrolean Iceman, Raul J. Cano, Friedrich Tiefenbrunner, Massimo Ubaldi, Clarissa Del Cueto, Stefania Luciani, Tobe Cox, Paula Orkand, Karl H. Kunzel, Franco Rollo
Sequence Analysis Of Bacterial Dna In The Colon And Stomach Of The Tyrolean Iceman, Raul J. Cano, Friedrich Tiefenbrunner, Massimo Ubaldi, Clarissa Del Cueto, Stefania Luciani, Tobe Cox, Paula Orkand, Karl H. Kunzel, Franco Rollo
Biological Sciences
The male human body found in an Alpine glacier on September 19, 1991 ("Tyrolean Iceman") has, for the first time in history, given scientists a chance to perform detailed anatomical, histological, and molecular investigations on the organs of a person from the Neolithic Age (5350-5100 B.P.). In the present study, tissue samples aseptically taken from the stomach and the colon of the mummy were utilized for DNA extraction, and the DNA was PCR-amplified, using primer pairs designed to bind to fragments of the 16s ribosomal RNA gene (16s rDNA) of a broad range of bacteria. The PCR products were cloned …
Delivering Copper Within Plant Cells, Edward Himelblau, Richard M. Amasino
Delivering Copper Within Plant Cells, Edward Himelblau, Richard M. Amasino
Biological Sciences
Two genes recently identified in Arabidopsis thaliana may be involved in sequestering free copper ions in the cytoplasm and delivering copper to post-Golgi vesicles. The genes COPPER CHAPERONE and RESPONSIVE TO ANTAGONIST1 are homologous to copper-trafficking genes from yeast and humans. This plant copper-delivery pathway is required to create functional ethylene receptors. The pathway may also facilitate the transport of copper from senescing leaf tissue. In addition, several other genes have been identified recently that may have a role in copper salvage during senescence.
Energetics Of Larval Swimming And Metamorphosis In Four Species Of Bugula (Bryozoa), Dean E. Wendt
Energetics Of Larval Swimming And Metamorphosis In Four Species Of Bugula (Bryozoa), Dean E. Wendt
Biological Sciences
The amount of energy available to larvae during swimming, location of a suitable recruitment site, and metamorphosis influences the length of time they can spend in the plankton. Energetic parameters such as swimming speed, oxygen consumption during swimming and metamorphosis, and elemental carbon and nitrogen content were measured for larvae of four species of bryozoans, Bugula neritina, B. simplex, B. stolonifera, and B. turrita. The larvae of these species are aplanktotrophic with a short free-swimming phase ranging from less than one hour to a maximum of about 36 hours. There is about a fivefold difference in larval volume …
Protozoan Free Colonies Of Lepidoptera, Kingston L. H. Leong
Protozoan Free Colonies Of Lepidoptera, Kingston L. H. Leong
Biological Sciences
A method for the establishment and maintenance of colonies of Lepidoptera which are free of contamination with protozoa is provided. The colonies consists of individuals capable of breeding and producing viable, noncontaminated butterflies.
Isolating Pcr-Quality Dna From Human Feces With A Soil Dna Kit, Brian G. Clement, Christopher L. Kitts
Isolating Pcr-Quality Dna From Human Feces With A Soil Dna Kit, Brian G. Clement, Christopher L. Kitts
Biological Sciences
No abstract provided.
Type I Nitroreductases In Soil Enterobacteria Reduce Tnt (2,4,6-Trinitrotoluene) And Rdx (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine), Christopher Kitts, Chad E. Green, Rebecca A. Otley, Marc A. Alvarez, Pat J. Unkefer
Type I Nitroreductases In Soil Enterobacteria Reduce Tnt (2,4,6-Trinitrotoluene) And Rdx (Hexahydro-1,3,5-Trinitro-1,3,5-Triazine), Christopher Kitts, Chad E. Green, Rebecca A. Otley, Marc A. Alvarez, Pat J. Unkefer
Biological Sciences
Many enteric bacteria express a type I oxygen-insensitive nitroreductase, which reduces nitro groups on many different nitroaromatic compounds under aerobic conditions. Enzymatic reduction of nitramines was also documented in enteric bacteria under anaerobic conditions. This study indicates that nitramine reduction in enteric bacteria is carried out by the type I, or oxygen-insensitive nitroreductase, rather than a type II enzyme. The enteric bacterium Morganella morganii strain B2 with documented hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) nitroreductase activity, and Enterobacter cloacae strain 96-3 with documented 2,4,6-trinitrotoluene (TNT) nitroreductase activity, were used here to show that the explosives TNT and RDX were both reduced by a type …
Optical Discrimination Of A Phytoplankton Species In Natural Mixed Populations, David F. Millie, Mark A. Moline, Oscar Schofield
Optical Discrimination Of A Phytoplankton Species In Natural Mixed Populations, David F. Millie, Mark A. Moline, Oscar Schofield
Biological Sciences
Developing optical detection techniques for discriminating particular phytoplankon species in mixed assemblages has long been a goal of aquatic scientists. Previously, a processing algorithm for phytoplankton absorption spectra was reported that suggested detection of the red tide dinoflagellate Gymnodinium breve was possible. The algorithm evaluated the fourth derivative of the particulate absorption spectrum of an unknown sample and compared it to a standard fourth derivative spectrum for G. breve using a similarity index. We report here the first-time application of this technique to the detection of G. breve in natural, mixed phytoplankton communities. Pigment and spectral absorption data were collected …
Estimation Of Base Temperatures For Nine Weed Species, Scott J. Steinmaus, Timothy S. Prather, Jodie S. Holt
Estimation Of Base Temperatures For Nine Weed Species, Scott J. Steinmaus, Timothy S. Prather, Jodie S. Holt
Biological Sciences
Experiments were conducted to test several methods for estimating low temperature thresholds for seed germination. Temperature responses of nine weeds common in annual agroecosystems were assessed in temperature gradient experiments. Species included summer annuals (Amaranthus albus, A. palmeri, Digitaria sanguinalis, Echinochloa crus-galli, Portulaca oleracea, and Setaria glauca), winter annuals (Hirschfeldia incana and Sonchus oleraceus), and Conyza canadensis, which is classified as a summer or winter annual. The temperature below which development ceases (Tbase) was estimated as the x-intercept of four conventional germination rate indices regressed on temperature, by repeated probit analysis, …
Optical Fractionation Of Chlorophyll And Primary Production For Coastal Waters Of The Southern Ocean, Mark A. Moline, Barbara B. Prezelin
Optical Fractionation Of Chlorophyll And Primary Production For Coastal Waters Of The Southern Ocean, Mark A. Moline, Barbara B. Prezelin
Biological Sciences
Our objective was to quantify the potential variability in remotely sensed chlorophyll a (Chl a) and primary productivity in coastal waters of the Southern Ocean. From data collected throughout the springs/summers of 1991–1994, we calculated the proportion of water column Chl a and primary productivity within the upper optical attenuation length (K −1 par) and the satellite-weighted depth. The temporal variability was resolved every 2–3 days and was observed to be greater within years than between years. Three-year averages (n=223) revealed that 10.2 ± 3.6% of total Chl a and 14.8 ± 6.5% of production occurred …
Temporal And Spatial Variations In Macrofouling Of Silicone Fouling-Release Coatings, Christina Darkangelo Wood, Kathryn Truby, Judith Stein, Deborah Wiebe, Eric Holm, Dean Wendt, Celia Smith, Christopher Kavanagh, Jean Montemarano, Geoff Swain, Anne Meyer
Temporal And Spatial Variations In Macrofouling Of Silicone Fouling-Release Coatings, Christina Darkangelo Wood, Kathryn Truby, Judith Stein, Deborah Wiebe, Eric Holm, Dean Wendt, Celia Smith, Christopher Kavanagh, Jean Montemarano, Geoff Swain, Anne Meyer
Biological Sciences
Nontoxic, low surface free energy silicone coatings having reduced biofouling adhesion strength have been developed as an alternative to antifouling paints. Silicone coatings permit macrofouling to adhere; however, fouling can be removed easily by water pressure or light scrubbing. One of the current methods used to evaluate the performance of non-toxic silicone fouling-release coatings relies heavily on fouling coverage. The organismal community structure as well as total coverage can affect the ease of fouling removal from these coatings. This paper explores fouling coverage and organismal adhesion over time. Long-term fouling coverage data were collected at four sites (in Massachusetts, Hawaii …
Evaluation Of The Performance Enhancement Of Silicone Biofouling-Release Coatings By Oil Incorporation, Kathryn Truby, Christina Wood, Judith Stein, James Cella, John Carpenter, Christopher Kavanagh, Geoff Swain, Deborah Wiebe, David Lapota, Anne Meyer, Eric Holm, Dean Wendt, Celia Smith, Jean Montemarano
Evaluation Of The Performance Enhancement Of Silicone Biofouling-Release Coatings By Oil Incorporation, Kathryn Truby, Christina Wood, Judith Stein, James Cella, John Carpenter, Christopher Kavanagh, Geoff Swain, Deborah Wiebe, David Lapota, Anne Meyer, Eric Holm, Dean Wendt, Celia Smith, Jean Montemarano
Biological Sciences
In response to increased evidence of ecosystem damage by toxic antifouling paints, many researchers have developed nontoxic silicone fouling release coatings. The fouling release capability of these Systems may be improved by adding nonbonding silicone oils to the coating matrix. This idea has been tested by comparing the adhesion strength of hard- and soft-fouling organisms on a cured polydimethylsilicone (PDMS) network to that of the same network containing free polydi-methyldiphenylsilicone (PDMDPS) oil at five exposure sites in North America and Hawaii. Fouling coverage is discussed, together with the bioadhesion data, to emphasize that although these coatings foul the fouling is …
Time Course And Magnitude Of Synthesis Of Heat-Shock Proteins In Congeneric Marine Snails (Genus Tegula) From Different Tidal Heights, Lars Tomanek, George N. Somero
Time Course And Magnitude Of Synthesis Of Heat-Shock Proteins In Congeneric Marine Snails (Genus Tegula) From Different Tidal Heights, Lars Tomanek, George N. Somero
Biological Sciences
The time course and magnitude of the heat-shock response in relation to severity of thermal stress are important, yet poorly understood, aspects of thermotolerance. We examined patterns of protein synthesis in congeneric marine snails (genus Tegula) that occur at different heights along the subtidal to intertidal gradient after a thermal exposure (30°C for 2.5 h, followed by 50 h recovery at 13°C) that induced the heat-shock response. We monitored the kinetics and magnitudes of protein synthesis by quantifying incorporation of 35S-labeled methionine and cysteine into newly synthesized proteins and observed synthesis of putative heat-shock proteins (hsp’s) of size …
Energetic Dynamics And Anuran Breeding Phenology: Insights From A Dynamic Game, Shannon J. Mccauley, Sarah S. Bouchard, Brian J. Farina, Kavita Isvaran, Suhel Quader, Daniel W. Wood, Colette M. St. Mary
Energetic Dynamics And Anuran Breeding Phenology: Insights From A Dynamic Game, Shannon J. Mccauley, Sarah S. Bouchard, Brian J. Farina, Kavita Isvaran, Suhel Quader, Daniel W. Wood, Colette M. St. Mary
Biological Sciences
We designed a dynamic optimization model to examine anuran-breeding phenologies. We evaluated the fitness consequences for males adopting one of four alternative strategies: calling, satelliting, foraging, or hiding. Various factors potentially influence male behavior, including energy reserves, predation risk, cost of calling, probability of finding food, distribution of male energy states in the population, and probability of surviving to another breeding season. We manipulated these parameters to determine how strongly each affects breeding phenology and chorus structure. Manipulating parameters related to the energetic costs and benefits of individual decisions, we generated the three basic patterns of anuran breeding phenology: explosive, …