bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusual Response of a Cupric Ion Electrode in Prairie Lake Waters
Authors: Barica J.
Published: April 2011

The Orion cupric ion electrode exhibited the theoretical (Nernstian) response of 29–30 mV per concentration decade in deionized water solutions, but in certain moderately alkaline and moderately saline natural waters of the Canadian prairies (pH 7.8–8.6, specific conductance 950–6550 μS/cm) the response to added cupric ion of over 100 μg Cu/L was twice as great. The electrode was, nevertheless, usable in natural waters provided that calibration was made with water from the same source. Key words: water analysis (chemical), cupric ion electrode, copper, hard water
Ultrastructural Studies of Piscine Erythrocytic Necrosis (PEN) in Atlantic Herring (Clupea harengus harengus)
Authors: Reno Paul W. , Philippon-Fried Marie , Nicholson Bruce L. , Sherburne Stuart W.
Published: April 2011

Erythrocytes of PEN-positive Atlantic herring (Clupea harengus harengus) were examined to determine their ultrastructure. Cytoplasmic inclusions were of two types when observed under the electron microscope. The first type (type I) appeared coarsely granular, electron dense, round, and up to 1.5 μm in diameter. Virions were closely associated with this type of inclusion. The second type of inclusion (type II) had approximately the same appearance as the surrounding cytoplasm, from which it was separated by a discrete membrane, and was variable in size. Virions were not intimately associated with type II inclusions. Virions occurred singly or in clusters within the cytoplasm or in association with type I inclusions and were hexagonal and 145 nm in diameter. Virions were composed of a rigid hexagonal capsid 8 nm wide, a lighter 16-nm region, and a core 100 nm in diameter. The virus of PEN is presumptively classified as an Iridovirus. Key words: ultrastructure, erythrocytes, virology
Tissue Uptake, Subcellular Distribution, and Metabolism of 14CH3HgCl and CH3203HgCl by Rainbow Trout, Salmo gairdneri
Authors: Olson Kenneth R. , Squibb Katherine S. , Cousins Robert J.
Published: April 2011

Uptake, whole tissue, and subcellular distribution of methylmercury (MeHg) by rainbow trout, Salmo gairdneri, was studied during, and in three 2-wk intervals following, a single 24-h exposure to 14CH3HgCl and CH3203HgCl. Gel permeation chromatography of cytosol fractions was performed on select tissues. Gills contained approximately 10 times as much MeHg as any other tissue after 24-h exposure whereas concentrations were lowest for brain and skeletal muscle. In the 2-wk period following exposure, gill MeHg concentrations decreased to levels comparable with most other tissues; methylmercury in most other tissues increased and then decreased during the subsequent 4-wk period. Methylmercury levels in brain, skeletal muscle, and gonad were highest at 6 wk. During the 6-wk interval following MeHg exposure, the percent of mercury as inorganic mercury (Hg++) increased in gill, kidney, and liver and to a lesser extent in all other tissues except skeletal muscle. Total MeHg was greatest in cytosol fractions and usually made up from 50 to 80% of the total tissue mercury. In liver cytosol a methylmercury binding metallothionein-like species accounted for up to 40% of the total methylmercury bound. Inorganic mercury (Hg++), probably derived from demethylation of methylmercury, was associated with a metallothionein-like protein detected in gill tissue but no more than 6% of the total mercury in the soluble fraction was bound to this protein(s). Mercury binding to metallothionein-like proteins in kidney and splenic fractions was minimal in spite of relatively large amounts of mercury in the cytosol from these tissues. Metallothionein may act as a binding scavenger for methylmercury and inorganic mercury in fish. Key words: methylmercury, uptake by trout, tissue distribution, subcellular distribution, metallothionein, detoxification
Changes in the Predator–Prey Behavior of Fathead Minnows (Pimephales promelas) and Largemouth Bass (Micropterus salmoides) Caused by Cadmium
Authors: Sullivan J. F. , Atchison G. J. , Kolar D. J. , McIntosh A. W.
Published: April 2011

Increased prey vulnerability was demonstrated for fathead minnows (Pimephales promelas) undergoing acute (24-h) and subacute (21-d) sublethal cadmium exposure prior to interacting with largemouth bass (Micropterus salmoides). The lowest acute and subacute cadmium concentrations that increased prey vulnerability were 0.375 and 0.025 mg Cd/L, respectively, with the latter well below the maximum acceptable toxicant concentration for fathead minnows. Prey exposed to cadmium displayed altered behavior patterns, including abnormal schooling behavior. Key words: cadmium, behavior, predator–prey, bioassay, Micropterus salmoides, Pimephales promelas
Storage Stability of Channel Catfish (Ictalurus punctatus) in Relation to Dietary Level of α-Tocopherol
Authors: O'Keefe Timothy M. , Noble Richard L.
Published: April 2011

Fingerling channel catfish (Ictalurus punctatus) 12–15 cm long were fed semipurified diets containing 0, 5, 10, 20, 40, and 80 mg of dl-α-tocopherol acetate per 100 g dry diet, and slaughtered after 97 d. Storage stability of fillets for the different treatments was determined by 2-thiobarbituric acid analysis after 3 mo frozen storage and after 3 mo freezing followed by refrigeration for 3 d. Fillets from fish fed the two lowest α-tocopherol levels exhibited significant oxidative rancidity after frozen storage. All higher levels showed similar but negligible oxidation. The 3 d of additional refrigerated storage significantly increased the amount of fat oxidation in all fillets from fish fed less than 40 mg/100 g. These results strongly indicate that increased dietary levels of α-tocopherol are effective in increasing the storage stability of catfish fillets. Key words: storage stability, channel catfish, antioxidants, dl-α-tocopherol, 2-thiobarbituric acid
Navigation Primer for Fishermen.
Authors: Armstrong F. A. J.
Published: April 2011

not available
Analyses of Aromatic Hydrocarbons in Intertidal Sediments Resulting from Two Spills of No. 2 Fuel Oil in Buzzards Bay, Massachusetts
Authors: Teal John M. , Burns Kathryn , Farrington John
Published: April 2011

We have analyzed the two- and three-ring aromatic hydrocarbons from the Wild Harbor oil spill in September 1969 and the Winsor Cove oil spill in October 1974, in intertidal marsh sediments, using glass capillary gas-chromatographic and mass-fragmentographic analyses. Naphthalenes with 0–3 alkyl substitutions and phenanthrenes with 0–2 substitutions decreased in concentration with time in surface sediments. The more substituted aromatics decreased relatively less and in some cases actually increased in absolute concentration. The changes in composition of the aromatic fraction have potential consequences for the ecosystem and provide insight into geochemical processes of oil weathering. Key words: oil pollution, aromatic hydrocarbons; gas chromatography; gas chromatography–mass spectrometry; geochemistry; marsh; sediments; oil spills
Long-Term Fate of a Heavy Fuel Oil in a Spill-Contaminated B.C. Coastal Bay
Authors: Cretney W. J. , Wong C. S. , Green D. R. , Bawden C. A.
Published: April 2011

The fate of accidently spilled No. 5 fuel oil in a small coastal bay in British Columbia was observed 6 times during 4 yr. The oil's composition was first changed by loss of the lower molecular weight components by evaporation and dissolution. Biodegradation accounted for almost complete removal of n-alkanes in the 1st yr. Pristane and phytane were biodegraded more slowly, but were almost completely gone in 4 yr. The non-n-alkane components in the nC28–30 range seem to be the most resistant to degradation of all the components resolved in the gas chromatograms. The resistance to degradation of these components indicates their potential for long-term studies of oil spills. Key words: petroleum, fate, environment, gas chromatography, n-alkanes, pristane, marine fauna and flora
Preliminary Assessment of the Presence of Oil in the Ecosystem at Ekofisk After the Blowout, April 22–30, 1977
Authors: Mackie P. R. , Hardy R. , Whittle K. J.
Published: April 2011

The marine environment in the Ekofisk area was assayed for the presence of oil components after the blowout on Platform Bravo was brought under control. Several methods of assay were used but the results were not always strictly comparable. Relatively high fluorescence values were observed in water samples in the vicinity of the platform. However, gas–liquid chromatography of these samples indicated that although some of the hydrocarbon fractions now resembled crude oil, none had increased markedly in concentration. The presence of oil could be detected in the biota and taste panels were able to identify an oily taint at low level in some fish caught near the platform. A second survey some 2 mo after the spill indicated that little, if any, oil from the blowout remained in the water column. Key words: Ekofisk, petroleum, surface film, water, sediment, fish
Mechanical Dispersal of Oil Stranded in the Littoral Zone
Authors: Owens E. H.
Published: April 2011

The natural weathering and dispersion of oil stranded in the littoral zone depend on the type and volume of the oil and on the amount of available energy. Energy inputs can be biological, chemical, mechanical, or thermal; however, the single most important input appears to be from mechanical energy (winds, waves, tides, water levels, and ice). The residence time or persistence of stranded oils increases as mechanical energy levels at the shoreline decrease. The primary inputs of mechanical energy at the shoreline are due to wave action, and energy levels vary depending on the wind regime, fetch areas, and local exposure of a section of coast. In cold or polar climates, energy levels at the shoreline are reduced by the presence of ice on the sea or an ice foot on the beach. This review of the concepts associated with littoral processes, in terms of the mechanical dispersal of stranded oil, provides the basis for estimation of the persistence of oil on shorelines. Key words: petroleum (weathering, dispersal), coastal processes, wave energy, sea ice, ice foot, Canada
Microbial Ecology Studies of the Metula Spill in the Straits of Magellan
Authors: Colwell R. R. , Mills A. L. , Walker J. D. , Garcia-Tello P. , Campos-P. V.
Published: April 2011

The grounding of the tanker V.L.C.C. Metula in the Straits of Magellan in August 1974 provided a unique opportunity to study a massive spill in a cold region on a long-term basis. Removal of spilled oil from the Metula was solely by in situ physiochemical and biological mechanisms. Microbiological studies undertaken in May 1976 showed increased heterotrophic bacterial populations at oil-impacted sites. A cold-tolerant population of petroleum degrading bacteria was observed. From biodegradation studies, we concluded that oil degradation under in situ conditions proceeds relatively slowly, with marked persistence of Metula oil in the Straits of Magellan 2 yr after the original spill. Key words: petroleum degradation, oil spills, Straits of Magellan, microbial degradation of oil, Metula
Prudhoe Crude Oil in Arctic Marine Ice, Water, and Sediment Ecosystems: Degradation and Interactions with Microbial and Benthic Communities
Authors: Atlas R. M. , Horowitz A. , Busdosh M.
Published: April 2011

A variety of in situ models were used to simulate oil spills in different arctic ecosystems. Numbers of oil-degrading microorganisms were found to increase after oil contamination. Oil contamination of sediment resulted in mortality of indigenous invertebrates. Recolonization of oil-contaminated sediments began shortly after oil contamination but benthic communities were significantly different in oil-contaminated sediment compared with the control, 2 mo after oil contamination. Petroleum hydrocarbons were degraded slowly. Ice greatly restricted losses of light hydrocarbons. Following initial abiotic losses, biodegradation of oil was limited and did not significantly alter the relative percentages of hydrocarbons in the residual oil. We concluded that petroleum hydrocarbons will remain in arctic ecosystems for prolonged periods after oil contamination. Key words: oil, petroleum, contamination, arctic, microorganisms, benthos
Uptake of Hydrocarbons from Marine Sediments Contaminated with Prudhoe Bay Crude Oil: Influence of Feeding Type of Test Species and Availability of Polycyclic Aromatic Hydrocarbons
Authors: Roesijadi G. , Anderson J. W. , Blaylock J. W.
Published: April 2011

Selected benthic animals were exposed to marine sediments contaminated with Prudhoe Bay crude oil, and uptake of hydrocarbons was monitored under various experimental schemes. When uptake of aliphatic and diaromatic hydrocarbons by two deposit feeders, Macoma inquinata and Phascolosoma agassizii, was compared with that of a suspension feeder, Protothaca staminea, we found that the deposit feeders generally accumulated hydrocarbons to a greater extent than the suspension feeder. However, other factors, such as the intrinsic capabilities of species to accumulate hydrocarbons, also played an important role in the extent of contamination. Hydrocarbon concentrations in the bivalve species (M. inquinata and P. staminea) increased during the 60-d exposure period; whereas concentrations in the sipunculid Phascolosoma agassizii appeared to have reached an equilibrium relatively early in the exposure. Experiments on uptake of 14C-phenanthrene, -chrysene, -dimethylbenz[a]anthracene, and -benzo[a]pyrene by M. inquinata indicated that compounds directly associated with sediment were less available for uptake than those released from sediment to the surrounding seawater. Concentration factors for uptake from sediment were ≤ 0.2, while those for uptake from seawater were 10–1349. Additionally, the heavier molecular weight aromatic compounds tended to be more concentrated in tissue and retained for longer periods of time than the lighter compounds. Key words: petroleum, hydrocarbons, sediments, bivalve, sipunculid, feeding type
Pathological Changes in a Marine Fish After a 6-Month Exposure to Petroleum
Authors: Payne J. F. , Kiceniuk J. W. , Squires W. R. , Fletcher G. L.
Published: April 2011

Cunners (Tautogolabrus adspersus) were chronically exposed to Venezuelan crude in a flow-through seawater system. The survival rate was > 95%. The following parameters were examined: appearance of fish and internal organs from a series of color photographs; fish condition index; hematocrit; somatic indices of liver, heart, spleen, and gonads; eye lens diameter; and plasma chloride. Liver, kidney, heart, spleen, gonad, gill, muscle, and gut tissues were also examined from paraffin sections for pathological changes. There were significant differences in testis somatic index, lens diameter, and plasma chloride between the two fish groups. No histopatbological changes were observed. Key words: marine fish, petroleum, chronic exposure, pathological changes
Observations of a Cold-Water Intertidal Community After 5 Years of a Low-Level, Persistent Oil Spill from the General M.C. Meigs
Authors: Clark Jr. Robert C. , Patten Benjamin G. , DeNike Edward E.
Published: April 2011

A rich and productive intertidal community was exposed continually for over 5 yr to small quantities of a Navy Special fuel oil from the unmanned troopship General M.C. Meigs that came aground on the Washington coast in January 1972. Observations of animal and plant populations and their petroleum hydrocarbon uptake patterns showed early evidence of contamination and the persistence of the oil spill throughout the study period. Abnormal and dead urchins, and loss of algal fronds and pigment were observed in localized areas near the wreck for at least 1 yr. Within 2 mo of the accident, paraffinic hydrocarbons had been taken up by prominent members of the community and continued to appear in certain species even after 5 yr. Although changes were seen in certain species during the early days of this persistent low-level pollution incident, the community balance in this rocky, intertidal ecosystem does not appear to have been markedly altered. Key words: oil spill, hydrocarbons, General M.C. Meigs, petroleum contamination, biological effects
SESSION III. Summary and Overview: Long-Term Effects of Oil Spills on Marine Intertidal Communities
Authors: Mann K. H. , Clark R. B.
Published: April 2011

not available
Myxosoma cerebralis: Fluorescent Antibody Techniques for Antigen Recognition
Authors: Markiw Maria E. , Wolf Ken
Published: April 2011

Rabbits were immunized with antigens extracted from mature spores or prespore stages of Myxosoma cerebralis, and the resulting antisera and their globulins were used in direct and indirect fluorescent antibody techniques. Both kinds of antisera reacted with homologous spores and with stages of the organism that precede spores. When tested for specificity against spores of 12 other myxosporidans the direct fluorescent antibody technique showed cross-reactivity with only one other and that was a species of Myxosoma. The indirect fluorescent antibody technique showed some reactions across generic lines. The antisera have application in studies of the parasite's life cycle and in diagnostics. Key words: spores, parasites, direct fluorescent antibody techniques, indirect fluorescent antibody techniques, diagnosis, myxosporidans, whirling disease
Predation by Freshwater Seals on the Fish Community of Lower Seal Lake, Quebec
Authors: Power G. , Gregoire Jean
Published: April 2011

The presence of freshwater harbor seals (Phoca vitulina) in Lower Seal Lake, Quebec, has drastically modified the lake's fish community. Lake trout (Salvelinus namaycush) are the most affected; they are small (rarely exceed 55 cm fork length), their growth rate is faster than in neighboring lakes, their longevity is greatly reduced, the age at sexual maturity has been halved, and individual fecundity per unit weight has increased at the expense of egg diameter. Brook trout (S. fontinalis), the dominant fish species in the lake, show evidence of high mortality rates in the lake, but are protected during the vulnerable spawning period because their spawning sites are dispersed in tributary streams. Rough calculation suggests the seal population is small and that it consumes the lake's potential yield of fish annually. Key words: predation, freshwater seals, Phoca vitulina, Salvelinus namaycush, Salvelinus fontinalis
Leaping Behavior of Juvenile Coho (Oncorhynchus kisutch) and Atlantic Salmon (Salmo salar)
Authors: Symons Philip E. K.
Published: April 2011

Juveniles of coho (Oncorhynchus kisutch) and Atlantic salmon (Salmo salar) proved capable of leaping falls at least 5 body lengths in height. No species differences were apparent: both species leapt lower falls (12 cm) more readily than higher ones (27 and 57 cm) and proportionately more leaps occurred on days with temperatures between 14.0 and 17.0 °C than on days with lower temperatures. Key words: fish, freshwater fish, behavior, migrations, environmental conditions, temperature effects
Modified Staaland Device with Automatic Recording Techniques for Determining Salinity Preference in Fishes
Authors: Fivizzani Albert J. , Spieler Richard E.
Published: April 2011

Modifications were made in the design and filling procedure of the Staaland device used to study salinity preference in fish. Two photographic recording techniques that eliminate the need for direct observation of fish activity and allow for continuous monitoring of fish movement throughout several daily photoperiodic cycles are described. Key words: salinity, preference, gradient, fish, photography, recording
Calculation of the Average Age of Sexual Maturity in Marine Mammals
Authors: DeMaster Douglas P.
Published: April 2011

The average age of sexual maturity and first pregnancy are important criteria in evaluating the status of a population. However, the estimation procedure for these statistics should be sensitive to the different distributions of age-specific reproductive data and should also incorporate a variance estimate to facilitate comparisons between populations. The described procedure lends itself well to age-specific data and should be useful in discerning differences between populations of [Formula: see text] or more, if a sample of at least 25 is available for each age-class. Key words: reproduction, marine mammals, sexual maturity
Federal–Provincial Strategic Planning for Ontario Fisheries: Management Strategy for the 1980s
Authors: Loftus K. H. , Johnson M. G. , Regier H. A.
Published: April 2011

A new management strategy for Ontario fisheries was addressed by a federal–provincial task force in 1974–76. It was initiated in an atmosphere of concern over the deteriorating status of fish stocks in Ontario, and indeed elsewhere in Canada. The task force published interim documents on "Goals and Issues," on "Mandates," and on "Objectives." These received limited distribution for criticism. This report summarizes the proposed "Strategy." Speaking generally, it has become abundantly clear that our traditional approach to fisheries management — development-oriented, exploitive, open access — is no longer appropriate in the 1970s and 1980s. That approach, together with the accelerating impacts of land and water uses that conflict with fisheries, has resulted in serious losses in our resource base, particularly during the past two or three decades. A new approach to fisheries management, characterized generally by maintenance in the north and by rehabilitation in the south is now essential. Much of the scientific and technical knowledge needed for the new approach is already available. To apply that knowledge, and to achieve the new knowledge and current data series necessary to its application, a major new initiative is necessary. That initiative, though costly in comparison to past levels of expenditure, seems easily justified in terms of the current economic value of the resources. Furthermore, additional values attributable to fisheries resources are now gaining wide acceptance; e.g. healthy fish communities are indicators of healthy aquatic environments. The new initiative will require more than just funding. It will require the evolution of different value systems, and of new and/or more explicit policies regarding— a new level of public participation;— a "user pays" policy in place of the free access philosophy of the past — to meet some of the increased cost of managing the resource;— more limited access and increased emphasis on protection in place of the open access, common property approach of the past;— explicit recognition that "experimental management" is needed to gain the new knowledge necessary to manage;— recognition that management of fisheries requires greater attention to environmental quality matters;— explicit allocation of those parts of the resource base available for commercial and for recreational use;— new working arrangements between fisheries agencies and other institutions.
Harvesting Polluted Waters: Waste Heat and Nutrient-Loaded Effluents in the Aquaculture.
Authors: Mathias J. A.
Published: April 2011

not available
Pacific Seashores: A Guide to Intertidal Ecology.
Authors: Breen Paul A.
Published: April 2011

not available
Energy Flow – Its Biological Dimension. A Summary of I.B.P. in Canada, 1964–1974.
Authors: Johnson Lionel
Published: April 2011

not available
Aeromonas salmonicida in Atlantic salmon (Salmo salar): Occurrence of Specific Agglutinins to Three Bacterial Pathogens
Authors: Weber J. M. , Zwicker B. M.
Published: April 2011

In July 1975 the first confirmed isolation of Aeromonas salmonicida in the Canadian Atlantic region was made from victims of an epizootic among adult Atlantic salmon (Salmo salar) in the Restigouche River of northeastern New Brunswick. In studies on the sera from spawned Atlantic salmon broodstock from the Restigouche, Miramichi, and Margaree rivers, agglutinins to the ubiquitous A. hydrophila and the kidney disease (K.D.) corynebacterium were found in all three populations sampled; however, agglutinins to Aeromonas salmonicida were found only in salmon from the Restigouche River. When given an intraperitoneal injection of A. salmonicida cells alone or emulsified in Freund's complete adjuvant, a high percentage of Atlantic salmon parr produced antibodies against the immunogen, indicating that as yearlings the entire population was capable of an immune response to A. salmonicida. It is suggested that serological tests can provide a nondestructive means of obtaining presumptive evidence of contact between specific pathogens and individuals of a salmon population. Key words: Aeromonas salmonicida, A. hydrophila, K.D. bacterium, agglutinins, Atlantic salmon
Joint Segregation of Biochemical Loci in Salmonidae: Results from Experiments with Salvelinus and Review of the Literature on Other Species
Authors: May Bernie , Wright James E. , Stoneking Mark
Published: April 2011

An extensive survey of joint segregation is described involving 37 pairwise comparisons of 12 biochemical loci in 11 single pair matings of brook trout (Salvelinus fonlinalis) and 38 pairwise comparisons of 9 loci in an F1 splake (lake trout, Salvelinus namaycush × brook trout) backcross to brook trout mating. We report pseudolinkage of two duplicated malate dehydrogenase loci (MDH-3 and MDH-4) and statistically highly significant nonrandom segregation of MDH-1 with an alphaglycerophosphate dehydrogenase locus (AGP-1). Several additional cases of aberrant joint segregation are described. All known examinations of joint segregation in Salmonidae are reviewed. A uniform system of nomenclature and guidelines for future investigations are discussed. Key words: joint segregation, brook trout, splake hybrid, inheritance, electrophoresis, pseudolinkage, duplicate-genes
Fish Protein Concentrate: Panacea for Protein Malnutrition?
Authors: Dyer W. J.
Published: April 2011

not available
Physical Activity, Muscle, and the HSP70 Response
Authors: Kilgore J. Lon , Musch Timothy I. , Ross Christopher R.
Published: April 2011

Selye (1936) described how organisms react to various external stimuli (i.e., stressors). These reactions generally follow a programmed series of events and help the organism adapt to the imposed stress. The heat shock response is a common cellular reaction to external stressors, including physical activity. A characteristic set of proteins is synthesised shortly after the organism is exposed to stress. Researchers have not determined how heat shock proteins affect the exercise response. However, their role in adaptation to exercise and training might he inferred, since the synthetic patterns correlate well with the stress adaptation syndrome that Selye described. This review addresses the 70 kilodalton heat shock protein family (HSP70), the most strongly induced heat shock proteins. This paper provides an overview of the general heat shock response and a brief review of literature on HSP70 function, structure, regulation, and potential applications. Potential applications in health, exercise, and medicine are provided. Key words: heat shock, protein, exercise
Incomplete Muscle Activation After Training With Electromyostimulation
Authors: Hortobágyi Tibor , Lambert Jean , Scott Kevin
Published: April 2011

Training with voluntary or electromyostimulation (EMS)-evoked eccentric contractions should produce complete muscle activation, since EMS and eccentric contractions preferentially recruit large motor units. Subjects (22 women ages 18-40) were randomly assigned to a voluntary (VOL; n = 8), EMS (n = 8), or control group. VOL and EMS groups trained the quadriceps at the same, increasing force levels 4 times/week for 6 weeks using voluntary or EMS-evoked eccentric contractions. VOL improved voluntary more than EMS-evoked eccentric strength. EMS improved EMS-evoked strength more than voluntary. EMS training improved EMS-evoked eccentric strength more than VOL training improved voluntary eccentric strength. EMS-evoked to voluntary force ratio increased from 0.57 (±0.11) to 1.20 (±0.35) in EMS and did not change in VOL (all changes p < .05). Six of eight EMS subjects produced greater EMS-evoked force posttraining, suggesting incomplete muscle activation after EMS training. Key words: exercise, eccentric contraction, muscle activation
Effect of Energy Restriction on Muscle Function and Calcium Stimulated Protease Activity in Recreationally Active Women
Authors: Parkes Sabina C. , N Angelo , elcastro  , Mccargar Linda J. , Mckenzie Donald
Published: April 2011

The purpose of this study was to investigate whether changes in substrate oxidation that are caused by energy restriction influenced muscle function and skeletal muscle calcium stimulated protease activity in female athletes. Endurance athletes were randomly assigned to maintenance energy (100% kcal) or energy restricted (75% kcal) diet treatment groups for 14 days while maintaining regular activity. Body weight significantly decreased in the 75% diet group (−1.7 ± 0.3 kg; p < .05), while fat oxidation increased (p < .05). Minimal changes in quadriceps function (assessed using the Kin/Com isokinetic dynamometer) were observed following diet treatment, except selected loss of muscle function in the 75% diet group at a movement velocity of 120 deg/s. These results suggest that increased fat oxidation that is induced by an acute energy restriction does not promote loss of general muscle function and activation of calcium-sensitive muscle proteases. Key words: substrate oxidation, protein metabolism, contractile protein profiles, muscle biopsy, calpain
The caudal neurosecretory system: control and function of a novel neuroendocrine system in fish
Authors: Winter M J , Ashworth A , Bond H , Brierley M J , McCrohan C R , Balment R J
Published: April 2011

The caudal neurosecretory system (CNSS) of fish was first defined over 70 years ago yet despite much investigation, a clear physiological role has yet to be elucidated. Although the CNSS structure is as yet thought to be confined to piscine species, the secreted peptides, urotensins I and II (UI and UII), have been detected in a number of vertebrate species, most recently illustrated by the isolation of UII in humans. The apparent importance of these peptides, suggested by their relative phylogenetic conservation, is further supported by the complex control mechanisms associated with their secretion. The CNSS in teleosts is known to receive extensive and diverse innervation from the higher central nervous system, with evidence for the presence of cholinergic, noradrenergic, serotonergic, and peptidergic descending inputs. Recent observations also suggest the presence of glucocorticoid receptors in the flounder CNSS, supporting previous evidence for a possible role as a pituitary-independent mechanism controlling cortisol secretion. The most convincing evidence as to a physiological role for the CNSS in fish has stemmed from the direct and indirect influence of the urotensins on osmoregulatory function. Recent advances allowing the measurement of circulating levels of UII in the flounder have supported this. In addition, there is evidence to suggest some seasonal variation in peptide levels supporting the notion that the CNSS may have an integrative role in the control of coordinated changes in the reproductive, osmoregulatory and nutritional systems of migratory euryhaline species.
Chargaff difference analysis of the bithorax complex of Drosophila melanogaster
Authors: Dang Kha D , Dutt Previn B , Forsdyke Donald R
Published: April 2011

Much of the fruit fly genome is compact ("Escherichia coli mode"), indicating a genome-wide selection pressure against DNA with little adaptive function. However, in the bithorax complex (BX-C) homeodomain genes are widely dispersed with large introns ("mammalian mode"). Chargaff difference analysis of compact bacterial and viral genomes has shown that most mRNAs have the potential to form stem-loop structures with purine-rich loops. Thus, for many taxa if transcription is to the right, the top (mRNA synonymous) DNA strand has purine-rich loop potential, and if transcription is to the left, the top (template) strand has pyrimidine-rich loop potential. The best indicator bases for transcription direction are A and T for AT-rich genomes, and C and G for CG-rich genomes. Consistent with this, Chargaff difference analysis of BX-C genes and several non-BX-C genes shows that, whatever the mode, mRNAs have the potential to form stem-loop structures with A-rich loops. We confirm that many potential open reading frames in the BX-C are unlikely to be functional. Conversely, we suggest that a few unassigned open reading frames may actually be functional. Since apparent organization in the mammalian mode cannot be explained in terms of unacknowledged open reading frames, yet the fruit fly genome is under pressure to be compact, it is likely that many BX-C functions do not involve the encoding of proteins.Key words: base ratios, base clusters, Chargaff's second parity rule, open reading frames, transcription direction, stem-loops.
Protein dynamics from NMR
Authors: Kay Lewis E
Published: April 2011

The past several years have seen the development of a significant number of new multidimensional NMR methods for the study of molecular dynamics spanning a wide range of time scales. Applications involving a large number of different biological systems have emerged and correlations with function have been established. Unique insights are obtained that are not available from structure alone, indicating the importance of dynamics studies for understanding function.Key words: NMR spin relaxation, protein dynamics, protein structure.
Topology of recombinant rat upstream binding factor
Authors: Ridsdale Ross A , Semotok Jennifer L , Larson Dawn E , Rothblum Lawrence I , Harauz George
Published: April 2011

Transmission electron microscopy and single particle electron crystallography were employed to reconstruct high-quality projection images of a recombinant, acidic tail deficient form of rat upstream binding factor. The upstream binding factor was found to be dimeric and approximately 10 nm in diameter with a central region of low density. Distinct nodes were observable, of size and spacing consistent with being HMG boxes 3 and 4. The dimerisation domain seemed most probably to be located in the internal region of the structure.Key words: upstream binding factor, transmission electron microscopy, RNA polymerase I transcription factor, single particle electron crystallography, molecular modelling.
NMR spectroscopic studies of I = 1/2 metal ions in biological systems
Authors: Öz Gülin , Pountney Dean L , Armitage Ian M
Published: April 2011

This article reviews the use of nuclear magnetic resonance methods of spin 1/2 metal nuclei to probe the metal binding site(s) in a variety of metalloproteins. The majority of the studies have involved native Zn(II) and Ca(II) metalloproteins where there has been isostructural substitution of these metal ions with the I = 1/2 111/113Cd(II) ion. Also included are recent studies that have utilized the 109Ag(I) ion to probe Cu(I) sites in yeast metallothionein and 199Hg(II) as a probe of the metal binding sites in mercury resistance proteins. Pertinent aspects for the optimal execution of these experiments along with the procedures for the metal substitution reactions are discussed together with the presentation of a 113Cd chemical shift correlation map with ligand type and coordination number. Specific examples of protein systems studied using the 111/113Cd and 109Ag nuclei include the metallothionein superfamily of Zn(II)- and Cu(I)-binding proteins from mammalian, invertebrate, and yeast systems. In addition to the structural features revealed by these metal ion nuclear magnetic resonance studies, important new information is frequently provided about the dynamics at the active-site metal ion. In an effort for completeness, other less frequently used spin 1/2 metal nuclei are mentioned.Key words: metallothionein, 111/113Cd, 199Hg, 109Ag, 57Fe, 205Tl, 195Pt, 207Pb, 119Sn, nuclear magnetic resonance.
An NMR study of ligand binding by maltodextrin binding protein
Authors: Gehring Kalle , Zhang Xiaochen , Hall Jason , Nikaido Hiroshi , Wemmer David E
Published: April 2011

Proton NMR spectra of maltodextrin binding protein from Escherichia coli were used to monitor conformational changes that accompany ligand binding. Chemical shift changes associated with the binding of different maltodextrins to maltodextrin binding protein were studied using one-dimensional difference spectra. Line-shape analysis of an isolated upfield methyl resonance was used to measure the kinetics of maltose binding at several temperatures. Maltose and linear maltodextrins caused similar changes to the upfield protein spectrum with no detectable differences between alpha and beta sugar anomers. Binding of a cyclic ligand, beta-cyclodextrin, caused smaller chemical shift changes than binding of linear maltodextrins. Two maltodextrin derivatives were also studied. Both maltohexaitol and maltohexanoic acid gave one-dimensional difference spectra that were intermediate between those of linear maltodextrins and beta-cyclodextrin. The methyl resonances at -1 and -0.35 ppm were assigned to leucine 160 on the basis of homonuclear COSY and TOCSY experiments and theoretical chemical shift calculations using the X-ray crystal structure of maltodextrin binding protein.Key words: maltose binding protein, chemical shifts, chemical exchange, sugar anomer specificity.
The association between familial distal renal tubular acidosis and mutations in the red cell anion exchanger (band 3, AE1) gene
Authors: Bruce Lesley J , Unwin Robert J , Wrong Oliver , Tanner Michael JA
Published: April 2011

In distal renal tubular acidosis (dRTA) the tubular secretion of hydrogen ion in the distal nephron is impaired, leading to the development of metabolic acidosis, frequently accompanied by hypokalemia, nephrocalcinosis, and metabolic bone disease. The condition can be familial, when it is usually inherited as an autosomal dominant, though there is a rarer autosomal recessive form associated with nerve deafness. It has been shown that the autosomal dominant form of dRTA is associated with a defect in the anion exchanger (AE1) of the renal collecting duct intercalated cell. This transporter is a product of the same gene (AE1) as the erythrocyte anion exchanger, band 3. In this review we will look at the evidence for this association. Studies of genomic DNA from families with this disorder have shown, both by genetic linkage studies and by DNA sequencing, that affected individuals are heterozygous for mutations in the AE1 gene whilst unaffected family members have a normal band 3 sequence. Mutations have been found in the region of proposed helices 6 and 7 of the membrane domain of band 3 and involve amino acids Arg-589 and Ser-613, and in the COOH-terminal domain of band 3. Studies of red cell band 3 from these families have provided information on the effect these mutations have on the structure and function of erythrocyte band 3. Expression studies of the erythroid and kidney isoforms of the mutant AE1 proteins, in Xenopus laevis oocytes, have shown that they retained chloride transport activity, suggesting that the disease in the dRTA families is not related simply to the anion transport activity of the mutated proteins. A possible explanation for the dominant effect of these mutant AE1 proteins in the kidney cell is that these mutations affect the targeting of AE1 from the basolateral to the apical membrane of the alpha-intercalated cell.Key words: erythrocyte, kidney, acidosis.
Spectroscopic and biophysical approaches for studying the structure and function of the P-glycoprotein multidrug transporter
Authors: Sharom Frances J , Liu Ronghua , Romsicki Yolanda
Published: April 2011

Multidrug resistance is a serious obstacle to the successful chemotherapeutic treatment of many human cancers. A major cause of multidrug resistance is the overexpression of a 170-kDa plasma membrane protein, known as P-glycoprotein, which appears to function as an ATP-driven efflux pump with a very broad specificity for hydrophobic drugs, peptides, and natural products. P-Glycoprotein is a member of the ABC superfamily and is proposed to consist of two homologous halves, each comprising six membrane-spanning segments and a cytosolic nucleotide binding domain. In recent years, P-glycoprotein has been purified and functionally reconstituted into lipid bilayers, where it retains both ATPase and drug transport activity. The availability of purified active protein has led to substantial advances in our understanding of the molecular structure and mechanism of action of this unique transporter. This review will focus on the recent application of fluorescence spectroscopy, infra-red spectroscopy, circular dichroism spectroscopy, electron microscopy, and other biophysical techniques to the study of P-glycoprotein structure and function.Key words: multidrug resistance, P-glycoprotein, fluorescence spectroscopy, infra-red spectroscopy, circular dichroism spectroscopy, differential scanning calorimetry, electron microscopy.
Experimental and numerical studies of geosynthetic-reinforced sand slopes loaded with a footing
Authors: Lee K M , Manjunath V R
Published: April 2011

This paper presents the results of a series of plane strain model tests carried out on both reinforced and unreinforced sand slopes loaded with a rigid strip footing. The objectives of this study are to (i) determine the influence of geosynthetic reinforcement on the bearing-capacity characteristics of the footing on slope, (ii) understand the failure mechanism of reinforced slopes, and (iii) suggest an optimum geometry of reinforcement placement. The investigations were carried out by varying the edge distance of the footing for three different slope angles and three different types of geosynthetic. It is shown that the load-settlement behaviour and ultimate bearing capacity of the footing can be considerably improved by the inclusion of a reinforcing layer at the appropriate location in the fill slope. The optimum depth of the reinforcement layer, which resulted in maximum bearing capacity ratio (BCR), is found to be 0.5 times the width of the footing. It is also shown that for both reinforced and unreinforced slopes, the bearing capacity decreases with an increase in slope angle and a decrease in edge distance. At an edge distance of five times the width of the footing, bearing capacity becomes independent of the slope angle. The effectiveness of the geosynthetic in improving the bearing capacity of the footing is attributed to its primary properties such as aperture size and axial stiffness. A numerical study using finite element analyses was carried out to verify the model test results. The agreement between observed and computed results is found to be reasonably good in terms of load-settlement behaviour and optimum geometry of georeinforcement placement.Key words: model tests, footing, bearing capacity, fill slope, finite element method, geosynthetic.
Performance of large-diameter honeycomb-design HDPE pipe under a highway embankment
Authors: Sargand Shad M , Masada Teruhisa
Published: April 2011

This paper presents field performance data on a 1.07 m (42 in.) diameter, honeycomb (HC) design HDPE pipe which is buried under 15.85 m (52 ft) of fill at a highway construction site in Ohio. The pipe was instrumented with six biaxial strain gages to monitor strains during initial backfilling and earth-pressure cells for measuring load for about 1 year. A portable linear variable displacement transducer device was used to detect changes in vertical and horizontal diameters at mid-length sections. The pipe performance has been monitored for 386 days. The vertical and horizontal deflections of the test pipe stabilized at 10% and +3%, respectively. The pipe exhibited localized short-wave deformations and inner wall tearing at springline due to combined actions from bending and ring compression. Elastic solutions of Burns and Richard and a finite element computer code CANDE-89 were applied with long-term moduli specified for the pipe material to evaluate their analytical results in relation to the measured field pipe performance.Key words: field performance, plastic pipe, highway embankment, deep burial, finite element.
Geological hazards and disasters in Newfoundland and Labrador
Authors: Liverman David , Batterson Martin , Taylor David , Ryan Janice
Published: April 2011

A geological disaster occurs when natural geological processes impact on our activities, either through loss of life or injury or through economic loss. A geological hazard is a potential disaster. Geological hazard in the Province of Newfoundland and Labrador was studied by archival research using a variety of sources to document the historical record of disaster. This record, although undoubtedly incomplete and selective, demonstrates that the province was affected by numerous geological disasters that inflicted a major economic and social cost. At least 80 people have been killed in Newfoundland and Labrador since 1863 in such incidents, including debris flows, rockfalls, avalanches, and tsunamis. Many Newfoundland communities have developed at the base of steep slopes and are therefore prone to landslides and avalanches or are built adjacent to the coast and are susceptible to storm damage. The economic cost is difficult to estimate, but remedial measures for individual events range from Can$ 20 000 for the construction of 50 m of gabions and retaining walls to Can$ 3 000 000 for community-level coastal flood-protection measures. Many of the documented geological disasters were unavoidable and were the inevitable result of geography. However, some were predictable and therefore preventable, either because a similar event had previously occurred in the same area or because geological factors, such as rapid coastal erosion or rising relative sea levels, were not considered during the planning process. The identification of serious avalanche and rockfall hazards in the Battery, St. John's, has led to installation of protective measures. Archival research methods provide a cheap, effective, and useful means of defining regional geological hazard. Key words: avalanche, landslide, rockfall, hazard, tsunami.
Earth pressures on unyielding retaining walls of narrow backfill width
Authors: Take W A , Valsangkar A J
Published: April 2011

Arching theory predicts a significant reduction in earth pressures behind retaining walls of narrow backfill width. An extensive series of centrifuge tests has been performed to evaluate the use of flexible subminiature pressure cells in the centrifuge environment and their subsequent use to measure lateral earth pressures behind retaining walls of narrow backfill width. Although the flexible earth pressure cells exhibit hysteresis and nonlinear calibration behaviour, the extensive calibration studies indicate that stiff diaphragm type earth pressure cells may be used with replicate models to measure earth pressures. Measurements of lateral pressures acting on the unyielding model retaining walls show good agreement with Janssen's arching theory. Tests on backfills bounded by vertical planes of dissimilar frictional characteristics indicate arching theory with an average interface friction angle provides a reasonable estimate of lateral earth pressures.Key words: fascia retaining walls, silos, earth pressures, pressure cells, centrifuge modelling.