Biology Commons^™

Long Term Management Strategies For The Western Rock Lobster Industry (4 Volumes) - Economic Efficiency Of Alternative Input And Output Based Management Systems In The Western Rock Lobster Fishery (Volume 2), Bob Lindner

Fisheries Management Papers

Since 1965, the Western Rock Lobster Fishery has been managed by what is essentially a license limitation scheme invoiving restricted entry for boats, and strict controls on the aggregate number of pots which can be used by the commercial fishing sector. By most measures, management of this fishery has been highly successful. Biological over-exploitation of the fish stock has been prevented, at least until recently. Notwithstanding these achievements, there is widespread concern that the future profitability, and even the viability of the industry is under threat unless the current management practices are reformed. Because of the complexity and intrinsic uncertainty …

Long Term Management Strategies For The Western Rock Lobster (4 Volumes) - Evaluation Of Management Options (Volume 1), B. K. Bowen, Rock Lobster Industry Advisory Committee

Fisheries Management Papers

This report has been written following approval by the Minister for Fisheries of a recommendation by the Rock LObster Industry Advisory Committee that a major evaluation of future management options for the western rock lobster fishery be undertaken. The report provides background information on the management strategies and principles of the fishery, its stock status, the use of input and output controls and the size of the fishing fleet. The report concludes with an examination of the effect of maintaining effort (input) controls and moving to a system of variable effort (TAE/ITEs) or moving to direct (output) controls on the …

Genetic Transformation Of The Lyme Disease Agent Borrelia Burgdorferi With Coumarin-Resistant Gyrb., D. Scott Samuels, Kathleen E. Mach, Claude F. Garon

Biological Sciences Faculty Publications

No useful method to genetically manipulate Borrelia burgdorferi, the causative agent of Lyme disease, has been developed previously. We have used resistance to the coumarin antibiotic coumermycin A1, an inhibitor of DNA gyrase, as a genetic marker to monitor the transformation of B. burgdorferi by electroporation. Introduction of site-directed mutations into the gyrB gene demonstrated that transformation was successful, provided evidence that homologous recombination occurs on the chromosome, and established that mutations at Arg-133 of DNA gyrase B confer coumermycin A1 resistance in B. burgdorferi. The coumermycin A1-resistant gyrB marker and genetic transformation can now be applied toward dissecting the …

Mechanism Of Gtp Hydrolysis By G-Protein Α Subunits, Christiane Kleuss, André S. Raw, Ethan Lee, Stephen R. Sprang, Alfred G. Gilman

Biological Sciences Faculty Publications

Hydrolysis of GTP by a variety of guanine nucleotide-binding proteins is a crucial step for regulation of these biological switches. Mutations that impair the GTPase activity of certain heterotrimeric signal-transducing G proteins or of p21(ras) cause tumors in man. A conserved glutamic residue in the α subunit of G proteins has been hypothesized to serve as a general base, thereby activating a water molecule for nucleophilic attack on GTP. The results of mutagenesis of this residue (Glu-207) in G(iα1) refute this hypothesis. Based on the structure of the complex of G(iα1) with GDP, Mg²⁺, and AlF₄/ …

Lag-2 May Encode A Signaling Ligand For The Glp-1 And Lin-12 Receptors Of C-Elegans, Samuel T. Henderson, Dali Gao, Eric J. Lambie, Judith Kimble

Dartmouth Scholarship

The C. elegans lag-2 gene is required for several cell-cell interactions that rely on the receptors GLP-1 and LIN-12. In this paper, we report that lag-2 encodes a putative membrane protein with sequence similarity to Drosophila Delta, a proposed ligand for the Notch receptor. Furthermore, we show that the lag-2 promoter drives expression of a reporter protein in the signaling distal tip cell (DTC) of the DTC/germline interaction. By in situ hybridization, we have found that endogenous lag-2 mRNA is present in the DTC but not the germ line. One fusion protein, called LAG-2::beta-gal(intra), rescues a lag-2 null mutant and …

The Pha-4 Gene Is Required To Generate The Pharyngeal Primordium Of Caenorhabditis-Elegans, Susan E. Mango, Eric J. Lambie, Judith Kimble

Dartmouth Scholarship

In the 4-cell Caenorhabditis elegans embryo, two blastomeres are destined to generate pharyngeal cells, each by a distinct developmental strategy: one pathway is inductive, while the other is autonomous. Here, we identify the pha-4 locus. In animals lacking pha-4 activity, an early step in pharyngeal organogenesis is blocked: no pharyngeal primordium is formed and differentiated pharyngeal cells are absent. Most other tissues are generated normally in pha-4 mutants, including cells related to pharyngeal cells by cell lineage and position. Thus, pha-4 activity is required to form the pharyngeal primordium. We propose that pha-4 marks a convergence of the inductive and …

Instructions For Building Two Live Traps For Small Mammals, Robert K. Rose

Biological Sciences Faculty Publications

The two live traps described herein, tested in the field over a period of 10 years, are sturdy, long-lasting, and relatively inexpensive to build with readily available materials and simple tools.

Force-Velocity And Power Characteristics Of Rat Soleus Muscle Fibers After Hindlimb Suspension, Kerry S. Mcdonald, C. A. Blaser, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The effects of 1, 2, and 3 wk of hindlimb suspension (HS) on force-velocity and power characteristics of single rat soleus fibers were determined. After 1, 2, or 3 wk of HS, small fiber bundles were isolated, placed in skinning solution, and stored at -20 degrees C until studied. Single fibers were isolated and placed between a motor arm and force transducer, functional properties were studied, and fiber protein content was subsequently analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Additional fibers were isolated from soleus of control and after 1 and 3 wk of HS, and fiber type distribution …

Chemical Composition Of Gaas Oxide Layers By Auger In-Depth Profiles And X-Ray Photoelectron Spectroscopy Experiments, J. F. Bresse, C. Cardinaud

Scanning Microscopy

GaAs oxide layers resulting from an oxygen plasma etching have been studied by Auger in-depth profiles and angle-resolved XPS experiments. From the Auger profiles, using the sequential layer sputtering (SLS) treatment, a quantitative determination of thickness and composition of the oxide layers has been performed. A model with several layers has been deduced. From the angle-resolved X-ray photoelectron spectroscopy (XPS) experiments, another model with several layers of different chemical compounds has also been deduced. The oxide layer is non-uniform in thickness and composition. Two or three different oxide layers are formed depending on the probed area. The interface layer is …

Urinary Citrate, Bone Resorption And Intestinal Alkali Absorption In Stone Formers With Fasting Hypercalciuria, Piergiorgio Messa, Giuseppe Mioni, L. Paganin, A. Cruciatti, P. Lo Greco, D. Turrin

Scanning Microscopy

Reduced citrate in urine and increased fasting excretion of calcium are abnormalities frequently reported in stone forming (SF) patients. Increased dietary acid (or reduced alkali) introduction or absorption may be a potential cause of both these pathological findings. To test this hypothesis, we studied 64 SF patients {32 with fasting hypercalciuria (FH) and 32 without FH (NFH)}. After a basal evaluation for nephrolithiasis, while on a 500 mg calcium diet, they were evaluated for: (1) daily intestinal alkali absorption (IAA), by urinary electrolyte excretion; (2) basal concentrations of PTH, calcitonin (CT) and 1,25(OH)2-VitD; (3) oral calcium load for evaluation of …

Characterization Of Metal Aggregates By Scanning Microscopy: Particle Sizes And Space Distribution In Intermetallic Particles, M. O. Delcourt, F. Yala, E. Merlen, S. Remita, N. Keghouche, E. Delarue

Scanning Microscopy

Various metal aggregates prepared using ionizing radiation were studied by microscopy techniques. A metal deposit onto a carbon felt obtained from solutions containing Pt and Ru was shown to consist of nanometric particles containing both metals. Another study deals with a subnanometric silver aggregate. The nuclearity of the aggregate was studied by scanning tunneling microscopy (STM). Additional information from pulse radiolysis experiments allowed the determination of the Ag₇³⁺ stoichiometry.

The third material consisted of Ag/Pd submicron powders (70/30 or 75/25% w/w) used in electronics, and made of spherical bimetallic grains; X-ray diffraction showed segregation. The spatial distribution of …

Molecular Imaging Of Petroleum Asphaltenes By Scanning Tunneling Microscopy: Verification Of Structure From 13c And Proton Nuclear Magnetic Resonance Data, G. W. Zajac, N. K. Sethi, J. T. Joseph

Scanning Microscopy

Scanning tunneling microscopy (STM) was used to verify the molecular structure of Maya asphaltene which had been derived from combined ¹³C and proton nuclear magnetic resonance (NMR) experiments. Petroleum asphaltenes are known to contain large polynuclear aromatic centers with aliphatic sidechains. Average molecular models of Maya asphaltenes were derived using studies which included combined proton and ¹³C NMR data to determine total aromatic carbon content and the ratio of peripheral to internal aromatic ring carbons. These parameters permitted estimating the average number of aromatic rings per condensed cluster.

These Maya asphaltenes were imaged by scanning tunneling microscopy (STM) …

A New Atomic Force Microscopy Technique For The Measurement Of The Elastic Properties Of Biological Materials, W. Xu, P. J. Mulhern, B. L. Blackford, M. H. Jericho, I. Templeton

Scanning Microscopy

We developed a new technique to measure elastic properties by using the atomic force microscope (AFM) tip to press samples into grooves etched in a GaAs substrate.

We measured the Young's modulus of β-chitin fibres with cross-sections less than 40 nm X 20 nm to be 1-2 X 10¹¹ N/m². In the isotropic approximation, the Young's modulus of the S-layer sheath of the archaeobacterium Methanospirillum hungatei was 1-3 X 10¹⁰ N/m². By testing the sheath to breaking strength we estimated the bacterium can sustain an internal pressure as high as 100-200 atmospheres (1-2 x …

Electron Spectroscopy And Atomic Force Microscopy Studies Of Dna Adsorption On Mica, Carol E. Rabke, Lisa A. Wenzler, Thomas P. Beebe Jr.

Scanning Microscopy

Various methods for the deposition of deoxyribonucleic acid (DNA) molecules on mica are investigated to determine their reproducibility, and to quantify their ability to bind DNA. The use of these deposition methods for sample preparation for biological scanning tunneling microscopy (STM) and atomic force microscopy (AFM) studies is discussed. Auger electron spectroscopy (AES) and electron spectroscopy for chemical analysis (ESCA) were used to investigate the quantity of DNA adsorbed. AFM images of DNA deposited using the methods investigated are presented. The combination of AFM results with AES and ESCA results provides a basic understanding of the deposition techniques studied and …

Nanowriting On An Atomically Flat Gold Surface With Scanning Tunneling Microscope, C. Lebreton, Z. Z. Wang

Scanning Microscopy

We present new experimental results of writing stable features on atomically flat surfaces of gold films. By applying successive voltage pulses across the tunneling gap in controlled atmosphere, nearly 150 individual holes are produced to record one message. The writing process has a higher success rate in nitrogen gas with the presence of water or ethanol vapour. Written letters remain stable for more than 4 days in dry nitrogen gas, in contrast to some previous STM results of monatomic step movement on the gold surface. By changing the vapour pressure, pulse amplitude and polarity, we succeed in controlling the gold …

Adsorption Of Fibrinogen On Thin Oriented Poly(Tetrafluoroethylene) (Ptfe) Fibres Studied By Scanning Force Microscopy, J. R. Rasmusson, R. Erlandsson, W. R. Salaneck, M. Schott, D. T. Clark, I. Lundström

Scanning Microscopy

We have investigated fibrinogen adsorption on ordered poly(tetrafluoroethylene), PTFE, fibres deposited on hydrophilic and hydrophobic silicon substrates. Fibrinogen molecules appear to adsorb with their long axis perpendicular to the fibre direction for PTFE fibres having widths of less than 100 nm. On these thin fibres, fibrinogen apparently forms close packed bands or clusters, consisting of small integer numbers of molecules arranged parallel to each other. On broader (> 100 nm) PTFE fibres, the fibrinogen forms two dimensional networks. The orientation of the molecules in these networks is random in the central flat part of the fibres but perpendicular to the …

High Resolution Electron Beam Induced Current Measurements In An Scanning Tunneling Microscope On Gaas-Mesfet, P. Koschinski, V. Dworak, L. J. Balk

Scanning Microscopy

Recently, the first results of electron beam induced current (EBIC) measurements in a scanning tunneling microscope (STM) have been reported. Although the acquired results match with those obtained in conventional EBIC investigations, the interpretation of the obtained results is still restricted solely to a qualitative discussion. In this paper, a quantitative approach is used for two-dimensional numerical simulations of induced currents in GaAs-MESFET leading to a first starting point for a sophisticated interpretation of the dependence of induced currents on experimental and device parameters.

Diluted And Undiluted Mercox Severely Destroy Unfixed Endothelial Cells. A Light And Electron Microscopic Study Using Cultured Endothelial Cells And Tadpole Tail Fin Vessels, J. Gassner, A. Lametschwandtner, T. Weiger, H. C. Bauer

Scanning Microscopy

Mercox is a methylmethacrylate-based resin which is widely used for vascular corrosion casting with subsequent scanning electron microscopic analysis. In the present study the effect of undiluted and diluted Mercox (4+1; volume + volume; Mercox: monomeric methylmethacrylate (MMA); 0.02 g catalyst MA/ml Mercox) and methylmethacrylate with and without catalyst MA (0.625 g/10 ml MMA) on fixed and unfixed endothelial cells was studied. Light microscopy (LM) of cultured capillary endothelial cells (ECs), which were replicated with diluted or undiluted Mercox shows degranulation and membrane perturbation of ECs, while no morphological changes occur in glutaraldehyde-prefixed ECs. Scanning electron microscopy (SEM) of replicas …

Superstructures Of Graphite Intercalation Compound Formed By Sodium-Hydroxide Solution Studied By Scanning Tunneling Microscopy, Koji Miyake, Aiso Yoshiaki, Makoto Komiyama, Hidemi Shigekawa

Scanning Microscopy

Highly oriented pyrolytic graphite (HOPG) treated with sodium hydroxide solution was found to show an X-ray diffraction pattern characteristic of a stage-8 intercalation compound. Superstructures such as 2 X 2, √3 X √3 and noble orthorhombic lattices were observed on the NaOH-treated graphite surfaces by scanning tunneling microscopy, as was previously observed on stage-1 alkali-metal graphite intercalation compound (GIC) surfaces formed by Li, K, Rb and Cs intercalates. The orthorhombic phase has a periodic structure formed by four bright and two dark rows, which were explained by the intercalant arrangement occupying two different sites, in the GIC.

Data Handling In Quantitative Microanalysis In Biology, V. Starý

Scanning Microscopy

In cell biology, electron probe X-ray microanalysis can reveal the distribution of chemical elements inside a single cell. The full description of a biological system (cell population, tissue) requires a great number of spot measurements. In quantitative analysis, the measurements are subject to experimental errors of several types; moreover, the relations between the resulting values are usually more interesting than the absolute concentrations. Nevertheless, the proper evaluation of quantitative values can discover information more on the object of study.

A system of simple statistical tests is suggested here which can solve several problems. Some concentration values can be far from …

Role Of Agglomeration In The Early Stages Of Papillar Stone Formation, O. Söhnel, F. Grases, L. Garcia-Ferragut

Scanning Microscopy

Possible effects of crystal agglomeration on the early stages of calcium oxalate papillar stone formation are evaluated. The collecting ducts are filled with liquid that flows laminarly as established through hydrodynamical and physicochemical considerations. Under such conditions, agglomeration due to laminar shear forces proceeds. Agglomeration of calcium oxalate monohydrate crystals present in urine at a concentration typical for clinically observed crystalluria cannot result in the formation of a particle sufficiently large enough to be retained in the Bellini's duct and become a papillar stone nidus (nucleus). Formation of such an aggregate during the passage time of urine through the duct …

Review Of Survival, Reproduction, And Behavior By J.R. Krebs And N.B. Davies, Marlene Zuk, Torgeir S. Johnsen, Gita R. Kolluru, Kurt A. Mckean, Bradd Schulke

Biological Sciences

No abstract provided.

Future Of Management Of Recreational Gill, Haul, And Cast Netting In Western Australia And Summary Of Submissions To The Netting Review, F. B. Prokop, L. M. Adams

Fisheries Management Papers

The results of a major review into recreational gill and haul netting in Western Australia were announced by the Minister for Fisheries, Hon. Monty House MLA on 24 December 1993. This document presents the findings of the recreational netting review and the process which resulted in the announced changed to management practices.

Direct Observation By Scanning Tunneling Microscopy Of The Two-Dimensional Lattice Structure Of The S-Layer Sheath Of The Archaeobacterium Methanospirillum Hungatei Gp1, B. L. Blackford, W. Xu, M. H. Jericho, P. J. Mulhern, M. Firtel, T. J. Beveridge

Scanning Microscopy

Observation of the two-dimensional (2-D) 3 nm x 3 nm lattice structure of the S-layer sheath of the archaeobacterium Methanospirillum hungatei is reported for the first time by scanning tunneling microscopy. The samples consisted of sheath fragments deposited on a TaSe₂ substrate and coated with a Pt/Ir film. In addition to confirming the 2-D structure, the images reveal some new information about the nano-scale details of the sheath structure. A lateral resolution of 1 nm was achieved, suggesting that the grain size of the Pt/Ir films was much less than for similar films deposited on a smooth metal surface.

Benthic-Pelagic Links: Responses Of Benthos To Water-Column Nutrient Enrichment, S. C. Blumenshine, Yvonne Vadeboncoeur, D. M. Lodge, K. L. Cottingham, S. E. Knight

Biological Sciences Faculty Publications

Although the responses of pelagic algae and invertebrates to gradients of nutrient enrichment are well known, less is known about the responses of benthos to such gradients or how benthic and pelagic responses may interact. We performed a 9-wk experiment in 2000-L mesocosms in the field to test for the effect of water-column nutrient enrichment on phytoplankton, algae on sediments (epipelon) and hard surfaces (plastic strips), as well as pelagic and benthic primary consumers. The experimental design consisted of 4 nutrient enrichment rates (0, 0.5, 1.0 and 2.0 μg P L^-1 d^-1, together with N to yield …

A Small Family Of Elements With Long Inverted Repeats Is Located Near Sites Of Developmentally Regulated Dna Rearrangement In Tetrahymena Thermophila, John M. Wells, Jay Lee Edward Ellingson, Diana M. Catt, Patricia J. Berger, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

Extensive DNA rearrangement occurs during the development of the somatic macronucleus from the germ line micronucleus in ciliated protozoans. The micronuclear junctions and the macronuclear product of a developmentally regulated DNA rearrangement in Tetrahymena thermophila, Tlr1, have been cloned. The intrachromosomal rearrangement joins sequences that are separated by more than 13 kb in the micronucleus with the elimination of moderately repeated micronucleus-specific DNA sequences. There is a long, 825-bp, inverted repeat near the micronuclear junctions. The inverted repeat contains two different 19-bp tandem repeats. The 19-bp repeats are associated with each other and with DNA rearrangements at seven locations …

What Science Can And Cannot Offer To A Religious Narrative, Ursula W. Goodenough

Biology Faculty Research

A molecular/cell biologist offers perspectives on the contributions that the scientific worldview might and might not make to religious though. It is argued that two essential features of institutionalized religions–their historical context and their supernatural orientation—are not addressed by the sciences, nor can the sciences contribute to the art and ritual that elicit states of faith and transcendence. The sciences have, however, important stories (myths) to offer, stories that have the potential to unify us, to tell us what is sacred, what has meaning, and how we might best proceed.

This paper, in slightly different form, was first presented before …

Etiology Of Experimental Calcium Oxalate Monohydrate Nephrolithiasis In Rats, W. C. De Bruijn, E. R. Boevé, P. R. W. A. Van Run, P. P. M. C. Van Miert, J. C. Romijn, C. F. Verkoelen, L. C. Cao, F. H. Schröder

Scanning Microscopy

In a rat-model system, tubular crystal retention as a possible mechanism for the etiology of nephrolithiasis in man, was studied by conventional transmission electron microscopy. The animals were supplied for nine days with a crystal-inducing diet, with ethylene glycol plus NH₄Cl in their drinking-water. After this induction period, a two day regime with fresh drinking-water was included, to allow crystals to be removed by spontaneous crystalluria. After aldehyde fixation of the rat kidneys, large crystals were seen inside the tubular lumen. The crystals were attached to cell surfaces and covered by neighboring epithelial cells. Some crystals were overgrown …

Electronic Trap Microscopy - A New Mode For Scanning Electron Microscopy (Sem), H. -J. Fitting, Th. Hingst, R. Franz, E. Schreiber

Scanning Microscopy

Insulating layers on conducting substrate are investigated by means of secondary electron field emission SEFE in a digital SEM. The kinetics of charge storage and release with time and temperature are controlled and recorded by an external computer.The evaluation is performed pixel-wise with respect to electronic trap concentration n_t0, trap capture cross section σ_c and thermal activation energy E_t. Mapping of these trap parameters indicates hidden inhomogenities, defects and pre-treatments of the dielectric layers as well as the pattern of thermal bleaching and release of electrons. The latter ones appear as inhomogeneous processes starting with …

Sequencing Of Proteins Extracted From Stones, J. P. Binette, M. B. Binette

Scanning Microscopy

Proteins from urinary tract and gallbladder stones were extracted and characterized to determine the composition of the matrix and possibly unravel the role of the organic phase in stone formation. Proteins from crushed stones were extracted by electrodialysis and concentrated in the Amicon centricon cartridge or by lyophilization after dialysis against distilled water. Aliquots were first analyzed by isoelectric focusing in gel and if suitable subjected to two-dimensional (2D) electrophoresis. The most promising spots were harvested and the N-terminal amino acids sequenced, thus providing maximum information with minimum expenditure of material. The 2D separations and amino acid sequences of several …