Biology Commons^™

First Record Of The Extinct Sawfish Propristis Schweinfurthi Dames, 1883 (Batoidea: Pristiformes: Pristidae) From The Middle Eocene Of Spain, Francesc Farrés, Harry L. Fierstine

Biological Sciences

A partial rostrum of Propristis schweinfurthi Dames, 1883 was collected in the Bartonian strata of northeastern Spain. The specimen represents the second record of the species from Europe, and the second occurrence of a sawfish (Mesopristis osonensis Farrés, 2003) from the Vic-Manlleu Marls Formation. In spite of some evidence to the contrary, Propristis probably preferred ecological conditions similar to extant sawfishes, i.e., inhabiting near shore tropical to subtropical seas with occasional excursions into freshwater.

Surgical Removal Of Right-To-Left Cardiac Shunt In The American Alligator (Alligator Mississippiensis) Causes Ventricular Enlargement But Does Not Alter Apnoea Or Metabolism During Diving, John Eme, June Gwalthney, Jason M. Blank, Tomasz Owerkowicz, Gildardo Barron, James W. Hicks

Biological Sciences

Crocodilians have complete anatomical separation between the ventricles, similar to birds and mammals, but retain the dual aortic arch system found in all non-avian reptiles. This cardiac anatomy allows surgical modification that prevents right-to-left (R–L) cardiac shunt. A R–L shunt is a bypass of the pulmonary circulation and recirculation of oxygen-poor blood back to the systemic circulation and has often been observed during the frequent apnoeic periods of non-avian reptiles, particularly during diving in aquatic species. We eliminated R–L shunt in American alligators (Alligator mississippiensis) by surgically occluding the left aorta (LAo; arising from right ventricle) upstream and …

Exhaustive Exercise Training Enhances Aerobic Capacity In American Alligator (Alligator Mississippiensis), John Eme, Tomasz Owerkowicz, June Gwalthney, Jason M. Blank, Bryan C. Rourke, James W. Hicks

Biological Sciences

The oxygen transport system in mammals is extensively remodelled in response to repeated bouts of activity, but many reptiles appear to be ‘metabolically inflexible’ in response to exercise training. A recent report showed that estuarine crocodiles (Crocodylus porosus) increase their maximum metabolic rate in response to exhaustive treadmill training, and in the present study, we confirm this response in another crocodilian, American alligator (Alligator mississippiensis). We further specify the nature of the crocodilian training response by analysing effects of training on aerobic [citrate synthase (CS)] and anaerobic [lactate dehydrogenase (LDH)] enzyme activities in selected skeletal muscles, …

Evaluating Connectivity Between Marine Protected Areas Using Codar High-Frequency Radar, Brian Zelenke, Mark A. Moline, Burt H. Jones, Steven R. Ramp, Greg B. Crawford, John L. Largier, Eric J. Terrill, Newell Garfield Iii, Jeffrey D. Paduan, Libe Washburn

Biological Sciences

To investigate the connectivity between central California marine protected areas (MPAs), back-projections were calculated using the network of high-frequency (HF) radar ocean surface current mapping stations operated along the California coast by the member institutions of the Coastal Ocean Currents Monitoring Program with funding provided by California voters through Propositions 40 & 50 and administered by the State Coastal Conservancy. Trajectories of 1 km resolution grids of water particles were back-projected from ten MPAs each hour, out through 40 days in the past, from each day in 2008, producing a map of where surface waters travel over a 40-day period …

Ornithocoprophilous Plants Of Mount Desert Rock, A Remote Bird-Nesting Island In The Gulf Of Maine, U.S.A, Nishanta Rajakaruna, Nathaniel S. Pope, Jose Perez-Orozco, Tanner B. Harris

Biological Sciences

Plants growing on seabird-nesting islands are uniquely adapted to deal with guano-derived soils high in N and P. Such ornithocoprophilous plants found in isolated, oceanic settings provide useful models for ecological and evolutionary investigations. The current study explored the plants found on Mount Desert Rock (MDR), a small seabird-nesting, oceanic island 44 km south of Mount Desert Island (MDI), Hancock County, Maine, U.S.A. Twenty-seven species of vascular plants from ten families were recorded. Analyses of guano-derived soils from the rhizosphere of the three most abundant species from bird-nesting sites of MDR showed significantly higher (P < 0.05) NO₃⁻, available …

A Hump-Shaped Relationship Between Isolation And Abundance Of Notonecta Irrorata Colonists In Aquatic Mesocosms, Shannon J. Mccauley, Christopher J. Davis, Jennifer Nystrom, Earl E. Werner

Biological Sciences

We examined the relationship between the isolation of experimental aquatic mesocosms and the abundance of an aquatic insect colonist, Notonecta irrorata, over two years. We used a curve-fitting approach to assess whether linear or quadratic models better describe the relationship between isolation and abundance. For two measures of mesocosm isolation, distance to nearest source and distance to the largest source population, there was a significant quadratic relationship between isolation and abundance. Abundance of colonizing N. irrorata was not found to be significantly related to a third measure of isolation, mesocosm connectivity. These results indicate that the relationship between habitat …

Density Dependence And The Economic Efficacy Of Marine Reserves, Crow White

Biological Sciences

Predictions on the efficacy of marine reserves for benefiting fisheries differ in large part due to considerations of models of either intra- or inter-cohort population density regulating fish recruitment. Here, I consider both processes acting on recruitment and show using a bioeconomic model how for many fisheries density dependent recruitment dynamics interact with harvest costs to influence fishery profit with reserves. Reserves consolidate fishing effort, favoring fisheries that can profitably harvest low-density stocks of species where adult density mediates recruitment. Conversely, proportion coastline in reserves that maximizes profit, and relative improvement in profit from reserves over conventional management, decline with …

Phylogeography Of The North American Red Fox: Vicariance In Pleistocene Forest Refugia, Keith B. Aubry, Mark J. Statham, Benjamin N. Sacks, John D. Perrine, Samantha M. Wisely

Biological Sciences

Fossil, archaeological, and morphometric data suggest that indigenous red foxes in North America were derived from vicariance in two disjunct refugia during the last glaciation: one in Beringia and one in the contiguous USA. To test this hypothesis, we conducted a phylogeographical analysis of the North American red fox within its presettlement range. We sequenced portions of the mitochondrial cytochrome b (354 bp) gene and D-loop (342 bp) from 220 historical red fox specimens. Phylogenetic analysis of the cytochrome b gene produced two clades that diverged c. 400 000 years before present (bp): a Holarctic and a Nearctic clade. …

Adiantum Viridimontanum, Aspidotis Densa, Minuartia Marcescens, And Symphyotrichum Rhiannon: Additional Serpentine Endemics From Eastern North America, Tanner Harris, Nishanta Rajakaruna

Biological Sciences

Serpentine outcrops around the world are known to harbor disproportionately high rates of plant endemism. Remarkable cases of serpentine endemism occur in New Caledonia and Cuba, with 3178 and 920 endemic taxa, respectively, found solely on serpentine. Despite the patchy occurrence of serpentine in eastern North America from Québec and Newfoundland south to Alabama, only one taxon, Cerastium velutinum var. villosissimum, has been broadly recognized as a serpentine endemic for the region. Based on reports in the literature, we suggest that Adiantum viridimontanum, Minuartia marcescens, and Symphyotrichum rhiannon be considered endemic to serpentine soils from the east coast …

Biology Of Ultramafic Rocks And Soils: Research Goals For The Future, Robert S. Boyd, Arthur R. Kruckeberg, Nishanta Rajakaruna

Biological Sciences

In absence of a text abstract the introduction of the article is provided.

Introduction

At this, the 6th International Conference on Serpentine Ecology, it seems timely to review briefl y the present status of the fi eld and to project the needs for future research. Although a great deal of serpentine research was done prior to 1960, as summarized by Krause (1958) and discussed briefl y by Brooks (1987), much of our progress in learning how serpentine geology affects plant and animal life occurred in the mid- to late 20th century. In that era, it was the landmark studies of …

Advances In Serpentine Geoecology: A Retrospective, Nishanta Rajakaruna, Robert S. Boyd

Biological Sciences

(In absence of a text abstract the first paragraph of the paper is provided.)

Serpentine habitats have long provided model settings for geoecological research (reviewed in Alexander et al. 2007, Brady et al. 2005, Brooks 1987, Kazakou et al. 2008, Kruckeberg 1984, Proctor and Woodell 1975, Raja-karuna et al 2009). Serpentine loosely refers to a broad group of minerals associated with the weathering of ultramafi c (high iron and magnesium-rich) rocks found along continental margins and orogenic belts. Soils associated with such rocks often differ from more widespread soils, being less fertile and having high concentrations of some heavy metals. …

Biological Effects Within No-Take Marine Reserves: A Global Synthesis, Sarah E. Lester, Benjamin S. Halpern, Kirsten Grorud-Colvert, Jane Lubchenco, Benjamin I. Ruttenberg, Steven D. Gaines, Satie Airamé, Robert R. Warner

Biological Sciences

The study and implementation of no-take marine reserves have increased rapidly over the past decade, providing ample data on the biological effects of reserve protection for a wide range of geographic locations and organisms. The plethora of new studies affords the opportunity to reevaluate previous findings and address formerly unanswered questions with extensive data syntheses. Our results show, on average, positive effects of reserve protection on the biomass, numerical density, species richness, and size of organisms within their boundaries which are remarkably similar to those of past syntheses despite a near doubling of data. New analyses indicate that (1) these …

Evolutionary Analysis Of Host Proteins Cd4, Cxcr4 And Ccr5, And Hiv/Siv Gp12, Lana Bunning

Biological Sciences

The acquired immune deficiency syndrome, AIDS, is a growing epidemic in the United States and the world. Since its discovery in 1981, the virus that causes AIDS, human immunodeficiency virus (HIV), has escalated. .Certain African ape (i.e., chimpanzees and gorillas) and monkey species are known to harbor forms of the virus termed SIV (simian immunodeficiency virus). Chimpanzees are the natural hosts of the SIV strains from which HIV-I evolved, but do not rapidly progress to AIDS, unlike their human relatives. In the wild, gorillas have been observed to harbor SIV, but this species' disease progression is currently unknown. As the …

The Role Of Trna Modification Systems In The Cellular Stress Response, Margaret Daly

Biological Sciences

Transfer RNA(tRNA) is a small chain of nucleotides that participates in protein synthesis by pairing its anticodon with an mRNA codon and transferring an amino acid to a growing polypeptide chain. tRNA methyltransferases are a group of enzymes that can modify nucleosides in or around the anticodon, as well as at other parts of the tRNA. Recently, some of these modifications have been reported to enhance the translation of proteins that help the cell respond to and/or repair DNA damage. We hypothesize that the modifications catalyzed by some of the tRNA methyltransferases (Trms) stabilize the interaction between the mRNA codon …

Effects Of Carbachol And Vitamin C On Submandibular Salivary Gland Branching Morphogenesis, Nasiratu Larry

Biological Sciences

The Submandibular Salivary Gland (SMG) is formed by iterative branching of epithelial cells into secretory acinar endbuds and branched ducts that are extensively innervated by parasympathetic nerves which can influence gland development. Carbarrylcholine or carbachol, (an acetylcholine neurotransmitter analog), is a drug that binds to and activates the acetylcholine receptor. Previous research has suggested that carbachol on SMGs might delay ductal differentiation and affect actin localization in cells lining the lumen of ducts. Vitamin C has been shown to enhance matrix protein synthesis, which may accelerate cell differentiation. My goal was to test whether and how carbachol or modulation of …

Thyroid Hormone Regulation Of Mrnas Encoding Thyrotropin Β-Subunit, Glycoprotein Α-Subunit, And Thyroid Hormone Receptors Α And Β In Brain, Pituitary Gland, Liver, And Gonads Of An Adult Teleost, Pimephales Promelas, Sean C. Lema, Jon T. Dickey, Irvin R. Schultz, Penny Swanson

Biological Sciences

Thyroid hormones (THs) regulate growth, morphological development, and migratory behaviors in teleost fish, yet little is known about the transcriptional dynamics of gene targets for THs in these taxa. Here, we characterized TH regulation of mRNAs encoding thyrotropin subunits and thyroid hormone receptors (TRs) in an adult teleost fish model, the fathead minnow (Pimephales promelas). Breeding pairs of adult minnows were fed diets containing 3,5, 3^,-triiodo-_L-thyronine (T₃) or the goitrogen methimazole for 10 days. In males and females, dietary intake of exogenous T₃ elevated circulating total T₃, while methimazole …

The Most Widely Publicized Gender Problem In Human Genetics, William D. Stansfield, Matthew A. Carlton

Biological Sciences

In two-child families containing at least one boy, the expected probability that such a family has two boys is 1/3, provided that the boy/girl (B/G) ratio is 1.0 and the population to which they belong has a binomial distribution of BB, (BG + GB), and GG families. It is commonly known that in most human populations the sex ratio at birth (i.e., the ratio of the number of boys to the number of girls) is greater than 1.0. Teachers and textbook writers seldom discuss the more realistic expected distributions in populations where the sex ratio is greater than 1.0. We …

Bioluminescence To Reveal Structure And Interaction Of Coastal Planktonic Communities, Mark A. Moline, Shelley M. Blackwell, James F. Case, Steven H.D. Haddock, Christen M. Herren, Cristina M. Orrico, Eric Terrill

Biological Sciences

Ecosystem function will in large part be determined by functional groups present in biological communities. The simplest distinction with respect to functional groups of an ecosystem is the differentiation between primary and secondary producers. A challenge thus far has been to examine these groups simultaneously with sufficient temporal and spatial resolution for observations to be relevant to the scales of change in coastal oceans. This study takes advantage of general differences in the bioluminescence flash kinetics between planktonic dinoflagellates and zooplankton to measure relative abundances of the two groups within the same-time space volume. This novel approach for distinguishing these …

Development, Implementation And Evaluation Of A Data-Assimilative Ocean Forecasting System Off The Central California Coast, Yi Chao, Zhijin Li, John Farrara, James C. Mcwilliams, James Bellingham, Xavier Capet, Francisco Chavez, Jei-Kook Choi, Russ Davis, Jim Doyle, David M. Fratantoni, Peggy Li, Patrick Marchesiello, Mark A. Moline, Jeff Paduan, Steve Ramp

Biological Sciences

The development and implementation of a real-time ocean forecast system based on the Regional Ocean Modeling System (ROMS) off the coast of central California are described. The ROMS configuration consists of three nested modeling domains with increasing spatial resolutions: the US West coastal ocean at 15-km resolution, the central California coastal ocean at 5 km, and the Monterey Bay region at 1.5 km. All three nested models have 32 vertical sigma (or terrain-following) layers and were integrated in conjunction with a three-dimensional variational data assimilation algorithm (3DVAR) to produce snapshots of the ocean state every 6 h (the reanalysis) and …

Forward And Reverse Genetics Of Rapid-Cycling Brassica Oleracea, Edward Himelblau, Laurie Mentzer, Erin J. Gilchrist, Kelly Buono, Colleen Bizzell, Robert Vogelzang, Thomas Osborn, Richard M. Amasino, Isobel A.P. Parkin, George W. Haughn

Biological Sciences

Seeds of rapid-cycling Brassica oleracea were mutagenized with the chemical mutagen, ethylmethane sulfonate. The reverse genetics technique, TILLING, was used on a sample population of 1,000 plants, to determine the mutation profile. The spectrum and frequency of mutations induced by ethylmethane sulfonate was similar to that seen in other diploid species such as Arabidopsis thaliana. These data indicate that the mutagenesis was effective and demonstrate that TILLING represents an efficient reverse genetic technique in B. oleracea that will become more valuable as increasing genomic sequence data become available for this species. The extensive duplication in the B. oleracea genome …

Mendel's Search For True-Breeding Hybrids, William D. Stansfield

Biological Sciences

No abstract provided.

Hydrothermal And Thermal Time Models For The Invasive Grass, Arundo Donax, Anthony Graziani, Scott J. Steinmaus

Biological Sciences

Controlled laboratory and field experiments were performed to determine the developmental response to temperature and moisture of Arundo donax, a riparian invasive grass and potential bioenergy crop. A logistic function was parameterized and used to predict thermal times to sprouting and the nine-leaf stage. Consistent estimates of the base temperature (T_b) and base water potential (ψ_b) below which development ceases were obtained from various statistical and mathematical analyses. Estimates of T_b and ψ_b were 12.7 ± 1.7 °C and −1.56 ± 0.43 MPa, respectively, for the median fraction of sprouting rhizomes. Median …

Genome Size As A Predictor Of Guard Cell Length In Arabidopsis Thaliana Is Independent Of Environmental Conditions, Barry H. Lomax, F. Ian Woodward, Ilia J. Leitch, Charles A. Knight, Janice A. Lake

Biological Sciences

• The recent discovery of a strong positive relationship between angiosperm genome size and stomatal guard cell length (GCL) opens the possibility of using plant fossil guard cell size as a proxy for changes in angiosperm genome size over periods of environmental change.
• The responses of GCL to environmental stimuli are currently unknown and may obscure this predictive relationship.
• Here, we investigated the effects of environmental variables (atmospheric CO₂, drought, relative humidity, irradiance, ultraviolet radiation and pathogen attack) on GCL in the model plant Arabidopsis thaliana to quantify environmentally induced variation.
• GCL responded to all …

Food Availability And Parasite Infection Influence Mating Tactics In Guppies (Poecilia Reticulata), Gita R. Kolluru, Gregory F. Grether, Eric Dunlop, Sandra H. South

Biological Sciences

Despite the important effects of diet and parasite infection on male reproductive behavior, few studies have simultaneously addressed their influence on intrasexual selection (male–male competition). We examined the synergistic effects of 2 naturally varying environmental factors, lifetime food intake and infection, with the monogenean parasite Gyrodactylus turnbulli on the mating tactics and foraging behavior of male guppies (Poecilia reticulata). We allowed fish to interact directly with each other during observations and found that unparasitized males won more intermale contests, courted females more frequently, and received positive responses to courtship displays more frequently than males that had been infected. …

Collaborative Research: An Effective Way To Collect Data For Stock Assessments And Evaluate Marine Proteced Areas In California, Dean E. Wendt, Richard M. Starr

Biological Sciences

Collaborative fisheries research (in contrast to cooperative research) is based on the intellectual partnership between scientists and fishermen and is an effective way to collect data for stock assessments and to evaluate marine protected areas. Collaborative fisheries research is discussed in the context of comanagement of marine resources and how it contributes to a more democratic form of fisheries management. Many benefits result from working together, including (1) the incorporation of fishers’ knowledge and expertise into the management process and (2) the development of shared perspectives derived through science-based investigations on the status of marine resources. The California Collaborative Fisheries …

Antifouling Character Of 'Active' Hybrid Xerogel Coatings With Sequestered Catalysts For The Activation Of Hydrogen Peroxide, Daniell M. Mcmaster, Stephanie M. Bennett, Ying Tang, John A. Finlay, Gregory L. Kowalke, Brian Nedved, Frank V. Bright, Maureen E. Callow, James A. Callow, Dean E. Wendt, Michael G. Hadfield, Michael R. Detty

Biological Sciences

Halide-permeable xerogel films prepared from sols containing 50 mol% aminopropyltriethoxysilane (APTES)/50 mol% tetraethoxysilane (TEOS) or 10 mol% APTES/90 mol% TEOS and 0.015 M selenoxide or telluride catalyst in the sol gave reduced settlement of cypris larvae of the barnacle Balanus amphitrite and larvae of the tubeworm Hydroides elegans in the presence of artificial seawater (ASW) and hydrogen peroxide (5-100 μM) relative to glass controls. Settlement of Ulva zoospores was lower on both the 50 mol% APTES/50 mol% TEOS and 10 mol% APTES/90 mol% TEOS xerogel formulations in comparison with glass controls with or without the added catalyst. The 50 mol% …

The Coriolis Effect, William D. Stansfield

Biological Sciences

No abstract provided.

Bryophytes Of Adjacent Serpentine And Granite Outcrops On The Deer Isles, Maine, U.S.A, Laura R. E. Briscoe, Tanner B. Harris, William Broussard, Eva Dannenberg, Fred C. Olday, Nishanta Rajakaruna

Biological Sciences

The serpentine-substrate effect is well documented for vascular plants, but the literature for bryophytes is limited. The majority of literature on bryophytes in extreme geoedaphic habitats focuses on the use of species as bioindicators of industrial pollution. Few attempts have been made to characterize bryophyte floras on serpentine soils derived from peridotite and other ultramafic rocks. This paper compares the bryophyte floras of both a peridotite and a granite outcrop from the Deer Isles, Hancock County, Maine, and examines tissue elemental concentrations for select species from both sites. Fifty-five species were found, 43 on serpentine, 26 on granite. Fourteen species …

Serpentine Geoecology Of Eastern North America: A Review, Nishanta Rajakaruna, Tanner B. Harris, Earl B. Alexander

Biological Sciences

Serpentine outcrops are model habitats for geoecological studies. While much attention has been paid to serpentine outcrops worldwide, the literature on eastern North American serpentine and associated biota is scant. This review examines the available literature, published and unpublished, on geoecological studies conducted on serpentine in eastern North America, from Newfoundland through Québec and New England south to Alabama. Most serpentine outcrops in the region have been mapped, but there have been few intensive mineralogical and pedological investigations. The limited soil analyses available suggest elevated levels of heavy metals such as Ni, near-neutral pH values, and Ca∶Mg ratios < 1, characteristic of serpentine soils worldwide. Botanical studies to date have largely focused on floristic surveys and the influence of fire exclusion and grazing on indigenous vegetation. To date, 751 taxa of vascular plants belonging to 92 families have been reported from serpentine outcrops in the region. Two taxa, Agalinis acuta …